Use of liquid cristalline polyimides in thermoplastic compositions

Abstract: This invention relates to a thermoplastic resin composition having good processability, comprising 99.9 ∼ 50 parts by weight of one or more thermoplastic resin and 0.1 ∼ 50 parts by weight of one or more liquid crystal type aromatic polyimide. The thermoplastic resin composition comprise 99.9 ∼ 50 parts by weight of one or more thermoplastic resin selected from the group consisting of aromatic polyimide, aromatic polyetherimide, aromatic polyamideimide, aromatic polyethersulfone and aromatic polyether ketone and 0.1 ∼ 50 parts by weight of one or more liquid crystal type aromatic polyimide having recurring structural units represented by the formula (1) : wherein R₁ ∼ R₅ is a hydrogen atom, fluorine atom, trifluoromethyl, methyl, ethyl or cyano and may be the same or different, and R is a tetravalent radical having 6 ∼ 27 carbon atoms and being selected from the group consisting of a monoaromatic radical, condensed polyaromatic radical and noncondensed aromatic radical connected each other with a direct bond or a bridge member. The present invention can provide thermoplastic resin compositions which have remarkably good processability and excellent thermal stability in addition to essentially excellent properties of each resin.

Description: The present invention relates to the use of a liquid crystal type aromatic polyimide as an additive for improving the melt processability of a thermoplastic resin composition, e.g. at least one of: an aromatic polyimide (eg. having excellent heat resistance, chemical resistance and mechanical strength), an aromatic polysulfone (eg. having excellent mechanical strength), an aromatic polyetherimide (eg. having excellent heat resistance) an aromatic polyamideimide (eg. having excellent heat resistance and mechanical strength), or an aromatic polyetherketone (eg. having excellent heat resistance and mechanical strength). Many thermoplastic resins having excellent heat resistance have been conventionally developed. In these resins, polyimide is excellent in mechanical strength and dimensional stability in addition to high heat resistance, and also has flame retardance and electrical insulation property. Thus, polyimide has been used in the field of electric and electronic appliances, space and aeronautic equipment and transport machinery and is expected in future for wide use in the field where heat resistance is required. Various polyimides having excellent characteristics have been conventionally developed. Proger et al. have disclosed in USP 4,065,345 polyimide having recurring structural units of the formula (A) : The polyimide is excellent in mechanical properties, thermal properties, electrical properties, solvent resistance and heat resistance, and has also been known as polyimide having melt-flowability. However, extrusion forming and injection molding of the polyimide are difficult because the polyimide has higher melt viscosity as compared with other common engineering plastics which can be extruded or injection molded. The present inventors have also found polyimide which is excellent in mechanical properties, thermal properties, electrical properties and solvent resistance, has heat resistance, and has recurring structural units represented by the formula (B): wherein X is a radical selected from the group consisting of a direct bond, divalent hydrocarbon having 1 ∼ 10 carbon atoms, hexafluorinated isopropylidene, carbonyl, thio and sulfonyl, and R is a tetravalent radical selected from the group consisting of an aliphatic radical having 2∼27 carbon atoms, alicyclic radical, monoaromatic radical, condensed polyaromatic radical and noncondensed polyaromatic radical having aromatic rings connected to each other with a direct bond or bridge member (Japanese Laid-Open Patent Sho 63-128025, 62-677717, 62-86021, 62-235381 and 63-128025). The above polyimide resins are novel thermoplastic resins having good properties which are essential for polyimide. For example, in the polyimide of the formula (B), polyimide having recurring structural units of the formula (6): has a glass transition temperature (hereinafter referred to simply as Tg) of 260°C, crystallization temperature (hereinafter refferred to simply as Tc) of 310∼340 °C and crystal melting point (hereinafter referred to simply as Tm) of 367∼385 °C, and is crystalline polyimide which is melt processable and excellent in chemical resistance. However, high temperature close to 400°C is required for processing the polyimide because of high Tm of 367∼385 °C. Polyimide is much superior in heat resistance and other properties but still inferior in processability to common engineering plastics such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polysulfone, polyphenylene sulfide, polyether ether ketone and polyetherimide. Some known polyimide has no distinct glass transition temperature though excellent in heat resistance and hence must be processed by such means as sinter molding when the polyimide is used for a molding material. Other known polyimide has a low glass transition temperature and is soluble in halogenated hydrocarbon solvent though excellent in processability and hence is unsatisfactory in view of resistance to heat and solvent. Both merits and drawbacks have thus been found in the properties of known polyimide. Further, aromatic polysulfone, aromatic polyetherimide, aromatic polyamideimide and aromatic polyether ketone are excellent in mechanical strength and dimensional stability in addition to high heat resistance and also have flame retardance and electrical insulation property. Thus, these plastics are used in the field of electric and electronic appliances, space and aeronautic equipment and transport machinery and expected in future for wide use in the filed where heat resistance is required. Aromatic polysulfone is an engineering plastic having good processability. However, aromatic polyetherimide, aromatic polyamideimide and aromatic polyether ketone which are called super engineering plastics have problems in processability and are desired to have good processability while maintaining high heat resistance. On the other hand, liquid crystal type high polymers are classified into thermotropic liquid crystal and lyotropic liquid crystal. Conventionally known liquid crystal type high polymers are polyester, polyesteramide and polyazomethine which are thermotropic liquid crystals and polyamide and polybenzothiazol which are lyotropic liquid crystals. However, polyimide exhibiting liquid crystal property has been quite unknown. Consequently, a resin composition obtained by mixing liquid crystal type polyimide with polyimide or other thermoplastic resins is quite unknown. The object of the invention is the use of one or more aromatic polyimides having liquid crystal properties as an additive for improving the melt processability of a thermoplastic resin composition without impairing essentially excellent characteristics of thermoplastic resin. Embodiments of the invention are the use of liquid crystal type aromatic polyimide having good flowability as an additive in an aromatic polyimide based thermoplastic resin composition for improving melt processability without impairing essentially excellent heat resistance of aromatic polyimide. Other embodiments of the invention are the use of liquid crystal type aromatic polyimide having good flowability as an additive in an aromatic polysulfone based thermoplastic resin composition for improving melt processability without impairing essentially excellent heat resistance of aromatic polysulfone. Further embodiments of the invention are the use of liquid crystal type aromatic polyimide having good flowability as an additive in an aromatic polyetherimide based thermoplastic resin composition for improving melt processability without impairing essentially excellent heat resistance of aromatic polyetherimide. Still further embodiments of the invention are the use of liquid crystal type aromatic polyimide having good flowability as an additive in an aromatic polyamideimide based thermoplastic resin composition for improving melt processability without impairing essentially excellent heat resistance and mechanical properties of aromatic polyamideimide. Other embodiments of the invention are the use of liquid crystal type aromatic polyimide having good flowability as an additive in an aromatic polyether ketone based thermoplastic composition for improving melt processability without impairing essentially excellent heat resistance and mechanical properties of aromatic polyether ketone. The present inventors have found that liquid crystal type aromatic polyimide can be added to aromatic polyimide, aromatic polysulfone, aromatic polyetherimide, aromatic polyamideimide or aromatic polyether ketone for improving melt processability without substantial impairment of the essentially excellent properties of each resin. That is, the present inventors have developed aromatic polyimide having recurring structural units of the formula (4) : (Japanese Laid-Open Patent Hei 03-160024.) Thereafter, the inventors have found that the aromatic polyimide exhibits liquid crystal property in the temperature range of 270 ∼ 300 °C. The liquid crystal property of the aromatic polyimide could be confirmed by observation under a polarization microscope. When the above aromatic polyimide was heated at a temperature increase rate of 10 °C/min on a hot plate equipped with a polarization microscope, Model BHS-751P (Trade Mark of OLYMPUS OPTICAL Co.), polarized light was observed in the temperature range 270∼300 °C. When the above polyimide was measured by DSC(Differential Scanning Calorimetry) with a DT-series, DSC-41M (Trade Mark of Shimadzu Co.) at a temperature increase rate of 10 °C/min, two heat absorption peaks were observed at around 275 °C and around 295 °C. It was confirmed that the liquid crystal property was exhibited in the temperature range between the two heat absorption peaks. Further, the aromatic polyimide which has a temperature between the two heat absorption peaks exhibits liquid crystal property and additionally has a very low melt viscosity in a molten state and is excellent in processability. As a result of mixing the aromatic polyimide which exhibits liquid crystal property with aromatic polyimide or other thermoplastic resin which is required to improve processability, the present inventors have found that processability of these resins can be improved. Thus the present invention is the use of a liquid crystal type aromatic polyimide and other aromatic polyimide or other thermoplastic resin. Types of embodiment of the present invention include such use in thermoplastic resin compositions comprising 99.9 ∼ 50 parts by weight of one or more thermoplastic resins and 0.1 ∼ 50 parts by weight of one or more liquid crystal type aromatic polyimides having recurring structural units represented by the formula (1) : wherein R 1 ∼R 5 is a hydrogen atom, fluorine atom, trifluoromethyl, methyl, ethyl or cyano and may be the same or different, and R is a tetravalent radical having 6∼27 carbon atoms and being selected from the group consisting of a monoaromatic radical, condensed polyaromatic radical and noncondensed polyaromatic radical having aromatic rings connected to each other with a direct bond or a bridge member. Preferably said liquid crystal type aromatic polyimide has a fundamental skeleton having recurring structural units of the formula (4) : It may be a copolymer comprising 1∼99 % by mol of the fundamental skeleton having recurring structural units of the formula (4) and 1∼99 % by mol of the fundamental skeleton having recurring structural units of formula (1) provided that they are not of the formula (4). The thermoplastic resin may be one or more resins selected from the group consisting of aromatic polyimide, aromatic polyetherimide, aromatic polyamideimide, aromatic polyethersulfone and aromatic polyether ketone. The thermoplastic resin aromatic polyimide may comprise a fundamental skeleton having recurring structural units represented by the formula (5) : wherein X is a divalent radical selected from the group consisting of a direct bond, isopropylidene, hexafluorinated isopropylidene, carbonyl, thio and sulfonyl, and R is a tetravalent radical as defined above. Preferred types of (5) include (6) and (7) : The thermoplastic resin aromatic polyimide may be a copolymer comprising 99∼1 % by mol of a fundamental skeleton having recurring structural units of the formula (6) and 1 ∼ 99 % by mol of a fundamental skeleton having recurring structural units of the formula (8) provided that they are not of the formula (6): Wherein R is wherein n is an integer of 0, 1, 2, or 3 ; Q is a direct bond, -O-, -S-, -CO-, -SO 2 -, -CH 2 -, -C(CH 3 ) 2 - or -C(CF 3 ) 2 - and may be the same or different when two or more Q connect three or more aromatic rings to each other ; and R" is one or more tetravalent radicals selected from the group consisting of wherein M is one or more divalent radicals selected from the group consising of and and particularly a thermoplastic resin composition wherein the fundamental skeleton having recurring structural units of the formula (8) comprises recurring structural units represented by the following formula (provided that they are not of the formula (6)): wherein R is the same as above. The aromatic polysulfone may comprise a fundamental skeleton having one or more recurring structural units represented by the formula (11) : wherein X is a direct bond, The aromatic polyimide may be an aromatic polyetherimide comprising a fundamental skeleton having one or more recurring structural units represented by the formula (12) : wherein X is or and Y is The aromatic polyamideimide may comprise a fundamental skeleton having one or more recurring structural units represented by the formula (D): Wherein Y is a divalent radical having 6∼27 carbon atoms, and particularly one or more recurring structural units of the formula (13) : and/or the formula (14) : The aromatic polyether ketone may comprise a fundamental skeleton having recurring structural units of the formula (15) : and/or the formula (16) : The aromatic polyimide and/or the liquid crystal type aromatic polyimide may be capped at the polymer chain end thereof with aromatic dicarboxylic anhydride of the formula (2) : wherein Z is a divalent radical having 6∼15 carbon atoms and being selected from a monoaromatic radical, condensed polyaromatic radical, and noncondensed polyaromatic radical having aromatic rings connected to each other with a direct bond or a bridge member and/or aromatic amine of the formula (3): V-NH 2 wherein V is a monovalent radical having 6 ∼ 15 carbon atoms and being selected from a monoaromatic radical, condensed polyaromatic radical and noncondensed polyaromatic radical having aromatic rings connected to each other with a direct bond or a bridge member, and preferably by capping the polymer chain end with phthalic anhydride and/or aniline. The thermoplastic resin compositions as used in the present invention have remarkably good processability and excellent thermal stability in addition to essentially excellent properties of each resin. Detailed Description of the Invention The liquid crystal type polyimide used in the invention exhibits liquid crystal property such as thermotropic liquid crystal and lyotropic liquid crystal. The liquid crystal type polyimide includes, for example, wholly aromatic polyimide which exhibits liquid crystal property and is represented by the formula (1) : wherein R 1 ∼R 5 are a hydrogen atom, fluorine atom, trifluoromethyl, methyl, ethyl or cyano and may be the same or different, and R is a tetravalent radical having 6∼27 carbon atoms and being selected from the group consisting of a monoaromatic radical, a condensed polyaromatic radical and a noncondensed polyaromatic radical having aromatic rings connected to each other with a direct bond or a bridge member. Preferred liquid crystal type polyimide includes liquid crystal type aromatic polyimide of the formula (4) : or a liquid crystal type aromatic polyimide copolymer comprising 1∼99 % by mol of the fundamental skeleton having recurring structural units of the formula (4) and 1 ∼ 99 % by mol of the fundamental skeleton having recurring structural units of the formula (1) [provided that they are not of the formula (4)]. Other preferred polymers include liquid crystal type aromatic polyimide and a liquid crystal type aromatic polyimide copolymer which are obtained by capping the polymer chain end of homopolymer or copolymer of liquid crystal type aromatic polyimide with aromatic dicarboxylic anhydride of the formula (2) : wherein Z is a divalent radical having 6∼15 carbon atoms and being selected from the group consisting of a monoaromatic radical, a condensed polyaromatic radical and a noncondensed polyaromatic radical having aromatic rings connected to each other with a direct bond or a bridge member, and/or aromatic monoamine of the formula (3) : V-NH 2 wherein V is a monovalent radical having 6∼15 carbon atoms and being selected from the group consisting of a monoaromatic radical, a condensed polyaromatic radical and a noncondensed polyaromatic radical having aromatic rings connected to each a direct bond or a bridge member. Such liquid crystal type aromatic polyimide can be prepared by reacting one or more aromatic diamine represented by the formula (17) below with one or more aromatic tetracarboxylic dianhydride represented by the formula (19) and by thermally or chemically imidizing the resultant polyamic acid. The aromatic diamines used in the process are represented by the formula (17) : wherein R 1 ∼R 5 are the same as in the formula (1), and include, for example, 1,3- or 1,4-bis[4-(4-aminophenoxy)-α,α-dimethylbenzyl] benzene, 1,3- or 1,4-bis[4-(3-aminophenoxy)-α,α -dimethylbenzyl]benzene, 1,3- or 1,4-bis[4-(4-amino-6-methylphenoxy)-α,α-dimethylbenzyl]benzene, 1,3- or 1,4-bis[4-(4-amino-6-fluorophenoxy)-α,α-dimethylbenzyl]benzene, 1,3- or 1,4-bis[4-(4-amino-6-trifluoromethylphenoxy)-α,α-dimethylbenzyl]benzene, 1,3- or 1,4-bis[4-(4-aminophenoxy)-3-dimethyl-α,α-dimethylbenzyl]benzene, 1,3- or 1,4-bis[4-(4-amino-6-methylphenoxy)-3-dimethyl-α,α-dimethylbenzyl]benzene, 1,3- or 1,4-bis[4-(3-amino-6-methylphenoxy)-3-dimethyl-α,α-dimethylbenzyl]benzene, 1,3- or 1,4-bis[4-(4-amino-6-trifluoromethylphenoxy)-3,5-dimethyl-α,α-dimethylbenzyl]benzene and 1,3- or 1,4-bis[4-(4-amino-6-cyanophenoxy)-α,α-dimethylbenzyl]benzene. These diamines are used singly or as a mixture. Particular preferred diamine is 1,3-bis[4-(4-aminophenoxy)-2,2-dimethylbenzyl]benzene having the formula (18) : When two or more diamines are used as a mixture, the above liquid crystal type aromatic polyimide copolymer can be obtained by simultaneously using the diamine of the formula (18) and other diamines. These aromatic diamines can be prepared by conducting usual reduction of corresponding nitro compounds, respectively, in the presence of a base in an aprotic polar solvent. Tetracarboxylic acid dianhydrides used in the invention are represented by the formula (19) : wherein R is a tetravalent radical having 6∼27 carbon atoms and being selected from the group consisting of a monoaromatic radical, a condensed polyaromatic radical and a noncondensed polyaromatic radical having aromatic rings connected to each other with a direct bond or a bridge member. Exemplary dianhydrides include pyromellitic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,2',3,3'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, bis(2,3-dicarboxyphenyl)ether dianhydride, bis(3,4-dicarboxyphenyl)ether dianhydride, bis(2,3-dicarboxyphenyl)sulfone dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride. 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride, 1,2-bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,2-bis(3,4-dicarboxyphenyl)ethane dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride, 2,2-bis[4-{3-(1,2-dicarboxy)phenoxy} phenyl]propane dianhydride, bis[4-{(4-(1,2-dicarboxy)phenoxy} phenyl]ketone dianhydride, bis[4-{(3-(1,2-dicarboxy)phenoxy} phenyl]ketone dianhydride, bis[4-{4-(1,2-dicarboxy)phenoxy} phenyl]sulfone dianhydride, bis[4-{3-(1,2-dicarboxy)phenoxy} phenyl]sulfone dianhydride, 4,4-bis[4-(1,2-dicarboxy)phenoxy} biphenyl dianhydride, 4,4-bis[3-(1,2-dicarboxy)phenoxy} biphenyl dianhydride, 2,2-bis[4-{4-(1,2-dicarboxy)phenoxy} phenyl]sulfide dianhydride, 2,2-bis[4-{3-(1,2-dicarboxy)phenoxy} phenyl]sulfide dianhydride, 2,2-bis[4-{4-(1,2-dicarboxy)phenoxy} phenyl]-1,1,1,3,3,3-hexafluoropropane dianhydride, 2,2-bis[4-{3-(1,2-dicarboxy)phenoxy} phenyl]-1,1,1,3,3,3-hexafluoropropane dianhydride, 1,3-bis[4-(1,2-dicarboxy)phenoxy]benzene dianhydride, 1,3-bis[3-(1,2-dicarboxy)phenoxy]benzene dianhydride, 1,4-bis[4-(1,2-dicarboxy)phenoxy]benzene dianhydride, 1,4-bis[3-(1,2-dicarboxy)phenoxy]benzene dianhydride, 1,3-bis[4-{(1,2-dicarboxy)-α,α-dimethyl} benzyl]benzene dianhydride, 1,3-bis[3-{(1,2-dicarboxy)-α,α-dimethyl} benzyl]benzene dianhydride, 1,4-bis[4-{(1,2-dicarboxy)-α,α-dimethyl} benzyl]benzene dianhydride and 1,4-bis[3-{(1,2-dicarboxy)-α,α-dimethyl} benzyl]benzene dianhydride. These aromatic tetracarboxylic dianhydrides can be used singly or as a mixture. Pyromellitic dianhydride is preferred in particular. The liquid crystal type aromatic polyimide for use in the invention can be prepared by using the diamines of the formula (17) and the tetracarboxylic acid dianhydrides of the formula (19) as main components. One or more of other diamines and tetracarboxylic acid dianhydrides can also be added to the polymerization reaction in the range giving no adverse effect on the liquid crystal property and other physical properties of resultant liquid crystal type aromatic polyimide. Other diamines which can be used in combination include, for example, m-phenylenediamine, o-phenylene diamine, p-phenylenediamine, m-aminobenzylamine, o-aminobenzylamine, 3-chloro-1,2-phenylenediamine, 4-chloro-1,2-phenylenediamine, 2,3-diamtnotoluene, 2,4-diaminotoluene, 2,5-diaminotoluene, 2,6-diaminotoluene, 3,4-diaminotoluene, 3,5-diaminotoluene, 2-methoxy-1,4-phenylenediamine, 4-methoxy-1,2-phenylenediamine, 4-methoxy-1,3-phenylenediamine, benzidine, 3,3-dimethylbenzidine, 3,3'-dimethoxybenzidine, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl methane, 4,4'-diaminodiphenyl methane, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone, 2,2-bis(4-aminophenyl)propane, 2,2-bis(3-aminophenyl)propane, 2-(3-aminophenyl)-2-(4-aminophenyl)propane, 2,2-bis(3-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 2,2-bis(4-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 2-(3-aminophenyl)-2-(4-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(3-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminobenzoyl)benzene, 1,4-bis(3-aminobenzoyl)benzene, 1,3-bis(4-aminobenzoyl)benzene, 1,4-bis(4-aminobenzoyl)benzene, 1,3-bis(3-amino-α,α-dimethylbenzoyl)benzene, 1,4-bis(3-amino-α,α-dimethylbenzoyl)benzene, 1,3-bis(4-amino-α,α-dimethylbenzoyl)benzene, 1,4-bis(4-amino-α,α-dimethylbenzoyl)benzene, bis[4-(3-aminophenoxy)phenyl]methane, bis[4-(4-aminophenoxy)phenyl]methane, 1,1-bis[4-(3-aminophenoxy)phenyl]ethane, 1,1-bis[4-(4-aminophenoxy)phenyl]ethane, 1,2-bis[4-(3-aminophenoxy)phenyl]ethane, 1,2-bis[4-(4-aminophenoxy)phenyl]ethane, 1,1-bis[4-(3-aminophenoxy)phenyl]propane, 1,1-bis[4-(4-aminophenoxy)phenyl]propane, 1,2-bis[4-(3-aminophenoxy)phenyl]propane, 1,2-bis[4-(4-aminophenoxy)phenyl]propane, 1,3-bis[4-(3-aminophenoxy)phenyl]propane, 1,3-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 1,1-bis[4-(3-aminophenoxy)phenyl]butane, 1,1-bis[4-(4-aminophenoxy)phenyl]butane, 1,2-bis[4-(3-aminophenoxy)phenyl]butane, 1,2-bis[4-(4-aminophenoxy)phenyl]butane, 1,3-bis[4-(3-aminophenoxy)phenyl]butane, 1,3-bis[4-(4-aminophenoxy)phenyl]butane, 1,4-bis[4-(3-aminophenoxy)phenyl]butane, 1,4-bis[4-(4-aminophenoxy)phenyl]butane, 2,2-bis[4-(3-aminophenoxy)phenyl]butane, 2,2-bis[4-(4-aminophenoxy)phenyl]butane, 2,3-bis[4-(3-aminophenoxy)phenyl]butane, 2,3-bis[4-(4-aminophenoxy)phenyl]butane, 2,2-bis[4-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 4,4'-bis(3-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy)biphenyl, bis[4-(3-aminophenoxy)phenyl]ketone, bis[4-(4-aminophenoxy)phenyl]ketone, bis[4-(3-aminophenoxy)phenyl]sulfide, bis[4-(4-aminophenoxy)phenyl]sulfide, bis[4-(3-aminophenoxy)phenyl]sulfone and bis[4-(4-aminophenoxy)phenyl]sulfone. These diamines can be used singly or as a mixture. The liquid crystal type aromatic polyimide used in the invention may be a homopolymer having the recurring structural units of the formula (1) or the formula (4) which is prepared as described above by using the aromatic diamine and the aromatic tetracarboxylic dianhydride as monomer components or a copolymer having a combination of the recurring structural units of the formula (1) and the formula (4). Also included is polyimide having at the polymer chain end thereof an aromatic ring which is unsubstituted or substituted with a radical having no reactivity for amine and dicarboxylic anhydride. The liquid crystal type aromatic polyimide having at the polymer chain end thereof an aromatic ring which is unsubstituted or substituted with a radical having no reactivity for amine and dicarboxylic anhydride can be prepared by reacting aromatic diamine represented by the formula (17): wherein R 1 ∼R 5 are the same as above, for example, 1,3-bis[4-(4-aminophenoxy)-α,α-dimethylbenzyl]benzene with aromatic tetracarboxylic dianhydride of the formula (19): wherein R is the same as above, for example, pyromellitic dianhydride in the presence of aromatic dicarboxylic anhydride of the formula (2): wherein Z is the same as above, and/or aromatic monoamine of the formula (3): V-NH 2 wherein V is the same as above. Exemplary aromatic dicarboxylic anhydrides of the formula (2) include phthalic anhydride, 2,3-benzophenonedicarboxylic anhydride, 3,4-benzophenonedicarboxylic anhydride, 2,3-dicarboxyphenyl phenyl ether anhydride, 3,4-dicarboxyphenyl phenyl ether anhydride, 2,3-biphenyldicarboxylic anhydride, 3,4-dicarboxyphenyl phenyl sulfone anhydride, 2,3-dicarboxyphenyl phenyl sulfide anhydride, 3,4-dicarboxyphenyl phenyl sulfide anhydride, 1,2-naphthalenedicarboxylic anhydride, 2,3-naphthalenedicarboxylic anhydride, 1,8-naphthalenedicarboxylic anhydride, 1,2-anthracenedicarboxylic anhydride, 2,3-anthracenedicarboxylic anhydride and 1,9-anthracenedicarboxylic anhydride. These dicarboxylic acid anhydrides can be substituted with a radical having no reactivity for amine and dicarboxylic anhydride and can be used singly or as a mixture. Phthalic anhydride is most preferred in view of properties and utility of polyimide and liquid crystal type polyimide to be obtained. The amount of aromatic dicarboxylic anhydride used is 0.001 ∼ 1.0 mol per mol of the diamine of the formula (17). The amount less than 0.001 mol leads to viscosity increase processing at high temperatures and causes deterioration of processability. On the other hand, the amount exceeding 1.0 mol results in lowered mechanical properties. Preferred amount is in the range of 0.01 to 0.5 mol. Aromatic monoamines of the formula (3) includes, for example, aniline, o-toluidine, m-toluidine, p-toluidine, 2,3-xylidine, 2,6-xylidine, 3,4-xylidine, 3,5-xylidine, o-chloroaniline, m-chloroaniline, p-chloroaniline, o-bromoaniline, m-bromoaniline, p-bromoaniline, o-nitroaniline, m-nitroaniline, p-nitroaniline, o-aminophenol, m-aminophenol, p-aminophenol, o-anisidine, m-anisidine, p--anisidine, o-phenetidine, m-phenetidine, p-phenetidine, o-aminobenzaldehyde, m-aminobenzaldehyde, p-aminobenzaldehyde, o-aminownzonitrile, m-aminobenzonitrile, p-aminobenzonitrile, 2-aminobiphenyl, 3-aminobiphenyl, 4-aminobiphenyl, 2-aminophenyl phenyl ether, 3-aminophenyl phenyl ether, 4-aminophenyl phenyl ether, 2-aminobenzophenone, 3-aminobenzophenone, 4-aminobenzophenone, 2-aminophenyl phenyl sulfide, 3-aminophenyl phenyl sulfide, 4-aminophenyl phenyl sulfide, 2-aminophenyl phenyl sulfone, 3-aminophenyl phenyl sulfone, 4-aminophenyl phenyl sulfone, α-naphthylamine, β-naphthylamine, 1-amino-2-naphthol, 2-amino-1-naphthol, 4-amino-1-naphthol, 5-amino-1-naphthol, 5-amino-2-naphthol, 7-amino-2-naphthol, 8-amino-1-naphthol, 8-amino-2-naphthol, 1-aminoanthracene, 2-aminoanthracene, and 9-aminoanthracene. These aromatic monoamines can be substituted with a radical having no reactivity for amine or dicarboxylic anhydride, and can be used singly or as a mixture. The amount of aromatic monoamine is 0.001∼1.0 mol per mol of the aromatic tetracarboxylic dianhydride of the above formula (19). The amount less than 0.001 mol leads to viscosity increase in processing at high temperatures and causes deterioration of processability. On the other hand, the amount exceeding 1.0 mol results in lowered mechanical properties. Preferred amount is in the range of 0.01 ∼ 0.5 mol. The liquid crystal type aromatic used in the invention can be prepared by any known processes. Following processes can be exemplified. (A) A process for preparing aromatic polyamic acid in an organic solvent, isolating the aromatic polyamic acid by removing the solvent under reduced pressure or by pouring the resulting aromatic polyamic acid solution into a lean solvent, and imidizing the polyamic acid by heating to obtain liquid crystal type aromatic polyimide. (B) A process for preparing an aromatic polyamic acid solution by the same procedures as (A), chemically imidizing polyamic acid by addition of a dehydrating agent such as acetic anhydride optionally in the presence of a catalyst, successively isolating resultant aromatic polyimide by known procedures and if desired, washing and drying the aromatic polyimide. (C) A process for preparing an aromatic polyamic acid solution by the same procedures as (A) and successively conducting solvent removal and thermal imidization at the same time by heating under reduced pressure. (D) A process for mixing raw material and solvents, and simultaneously conducting preparation of aromatic polyamic acid and imidization reaction thereof by heating optionally in the presence of a catalyst, azeotropic agent or dehydrating agent. In preparing the liquid crystal type aromatic polyimide by these processes, it is particularly preferred to carry out the reaction in an organic solvent. Organic solvents which can be used include, for example, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylmethoxyacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N-methylcaprolactam, 1,2-dimethoxyethane, bis(2-methoxyethyl)ether, 1,2-bis(2-methoxyethoxy)ethane, bis12-(2-methoxyethoxy)ethyl]ether, tetrahydrofuran, 1,3-dioxane, 1,4-dioxane, pyridine, picoline, dimethyl sulfoxide, dimethyl sulfone, tetramethyl urea, hexamethylphosphoramide, phenol, o-cresol, m-cresol, p-cresol, m-cresylic acid, p-chlorophenol, xylenols and anisole. These solvents can be used singly or as a mixture. When the liquid crystal type aromatic polyimide is prepared in the presence of aromatic dicarboxylic anhydride or aromatic monoamine in order to cap the polymer chain end, aromatic diamines, aromatic tetracarboxylic dianhydride, and aromatic dicarboxylic anhydride or aromatic monoamine are charged and reacted in the organic solvent by the following methods. (1) A method wherein an aromatic tetracarboxylic dianhydride is reacted with an aromatic diamine and successively a dicarboxylic anhydride or aromatic monoamine is added and the reaction continued. (2) A method wherein an aromatic diamine is reacted with an aromatic dicarboxylic anhydride and successively an aromatic tetracarboxylic dianhydride is added and the reaction continued. Alternatively, a method wherein an aromatic tetracarboxylic dianhydride is reacted with an aromatic monoamine and successively an aromatic diamine is added and the reaction continued. (3) A method wherein simultaneously an aromatic tetracarboxylic dianhydride, aromatic diamine and aromatic dicarboxylic anhydride or aromatic monoamine are charged and the reaction is carried out. Any of the above methods can be employed for progressing the reaction. In these methods, the reaction temperature for polymerization and imidization is 300°C or less. No particular limitation is imposed upon the reaction pressure and the reaction can be sufficiently carried out under atmospheric pressure. The reaction time differs depending upon the aromatic diamine, aromatic tetracarboxylic dianhydride, solvent and reaction temperature. A reaction time of 4∼24 hours is usually sufficient. Aromatic tetracarboxylic dianhydride can be reacted with aromatic diamine by the above methods in the presence of aromatic dicarboxylic anhydride and/or aromatic monoamine such as phthalic anhydride and/or aniline to prepare liquid crystal type aromatic polyimide capped at the polymer chain end with an unsubstituted aromatic ring such as or an aromatic ring substituted with a radical having no reactivity for amine or carboxylic acid anhydride. Next, the thermoplastic resin which can be used in the invention will be illustrated. Aromatic polyimide used in the invention comprises a fundamental skeleton having recurring structural units of the formula (5) : wherein X is a divalent radical selected from the group consisting of a direct bond, isopropylidene, hexafluorinated isopropylidene, carbonyl, thio and sulfonyl, and R is a tetravalent radical as defined above. In the aromatic polyimide of the formula (5), often used in particular are aromatic polyimide having recurring structural units of the formula (6) : (wherein X is a direct bond in the formula (5)), and aromatic polyimide having recurring structural units of the formula (20) : (wherein X is -SO 2 - in the formula (5)). Also effective is another aromatic polyimide having recurring structural units of the formula (7) : The present inventors have developed the following aromatic polyimide copolymer in order to improve processability of polyimide of the formula (B). The aromatic polyimide copolymer is also effective for the invention. The aromatic polyimide of the formula (B) is a crystalline polyimide which has Tg of 260°C, Tc of 310 ∼ 340 °C and Tm of 367 ∼ 385°C, and is melt processable and excellent in chemical resistance. However, high Tm of 367∼385 °C requires high processing temperature close to 400°C. In the case of comparing highly heat-resistant engineering plastics having similar levels of Tg, it has been generally known that crystalline resin having high crystallinity is excellent in chemical resistance and mechanical properties such as elastic modulus and amorphous resin having low crystallinity is excellent in processability. Thus, crystalline resin and amorphous resin individually have both merits and drawbacks. Consequently, it is further desired to improve processability of the crystalline polyimide having recurring structural units of the formula (B) while maintaining the essentially excellent heat resistance thereof. As a result of investigation in order to improve such aromatic polyimide, the present inventors have provided a crystalline aromatic polyimide copolymer comprising 99∼1 % by mol of a fundamental skeleton having recurring structural units of the above formula (B) and 1 ∼ 99 % by mol of a fundamental skeleton having recurring structural units of the formula (8) [provided that they are not of the formula (B)] : wherein R is wherein n is an integer of 0, 1, 2 or 3 ; Q is a direct bond, -O-, -S-, -CO-, -SO 2 -, -CH 2 -, -C(CH 3 ) 2 - or -C(CF 3 ) 2 - and may be the same or different when two or more Q connects three or more aromatic rings each other ; and R" is one ore more tetravalent radicals selected from the group consisting of wherein M is one or more divalent radicals selected from the group consisting of and The aromatic polyimide copolymers thus provided and particularly an aromatic polyimide copolymer wherein the recurring structural units of the formula (8) are represented by the following formula [provided that they are not of the formula (B),] : wherein R is the same as above; have been found to improve processability in an amorphous state at high temperature, to provide polyimide having high heat resistance by forming a crystalline state in use after processing, and alternatively to improve processability by maintaining an amorphous state both in processing and in use, and to provide heat resistance even in an amorphous state. Thus, a highly heat-resistant engineering plastic having good processability, excellent chemical resistance and high elastic modulus has been provided. The aromatic polyimide copolymer thus provided can be preferably used for the resin composition of the invention having improved melt-processability. Aromatic polyimide homopolymers and copolymers which can be used in the invention also include a capped aromatic polyimide homopolymer and copolymer obtained by capping the above aromatic polyimide homopolymer and copolymer with aromatic dicarboxylic anhydride of the formula (2) : wherein Z is a divalent radical as defined above, and/or with aromatic monoamine of the formula (3) : V-NH 2 wherein V is a monovalent radical as defined above. The homopolymers and copolymers of aromatic polyimide can be obtained by reacting one or more aromatic diamine with one or more aromatic tetracarboxylic dianhydride and thermally or chemically imidizing the resultant polyamic acid. That is, for example, the aromatic polyimide of the formula (5) can be obtained by reacting one or more aromatic diamine of the formula (21) : wherein X is a divalent radical selected from the group consisting of a direct bond, isopropylidene, hexafluorinated isopropylidene, carbonyl, thio and sulfonyl, or aromatic diamine of the formula (22) : with one or more aromatic tetracarboxylic dianhydride. Aromatic diamine which can be used for the reaction includes, for example, bis[4-(3-aminophenoxy)phenyl]methane, 1,1-bis[4-(3-aminophenoxy)phenyl]ethane, 1,2-bis[4-(3-aminophenoxy)phenyl]ethane, 1,1-bis[4-(3-aminophenoxy)phenyl]propane, 1,2-bis[4-(3-aminophenoxy)phenyl]propane, 1,3-bis[4-(3-aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 1,1-bis[4-(3-aminophenoxy)phenyl]butane, 1,2-bis[4-(3-aminophenoxy)phenyl]butane, 1,3-bis[4-(3-aminophenoxy)phenyl]butane, 1,4-bis[4-(3-aminophenoxy)phenyl]butane, 2,2-bis[4-(3-aminophenoxy)phenyl]butane, 2,3-bis[4-(3-aminophenoxy)phenyl]butane, 2,2-bis[4-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 4,4'-bis(3-aminophenoxy)biphenyl, bis[4-(3-aminophenoxy)phenyl]ketone, bis[4-(3-aminophenoxy)phenyl]sulfide and bis[4-(3-aminophenoxy)phenyl]sulfone. These aromatic diamines can be used singly or as a mixture. Preferred aromatic diamines are 4,4'-bis(3-aminophenoxy)biphenyl or bis [4-(3-aminophenoxy)phenyl]sulfone wherein X is a direct bond or a sulfone radical in the formula (21). 3,3'-Diaminobenzophenone of the formula (22) is also preferred. Aromatic tetracarboxylic dianhydrides used for the reaction are represented by the formula (19) : wherein R is a tetravalent radical as defined above. Exemplary aromatic tetracarboxylic dianhydrides include those used for the preparation of the liquid crystal type aromatic polyimide and have been already enumerated above. These aromatic tetracarboxylic dianhydrides can be used singly or as a mixture. Pyromellitic dianhydride is preferred. The aromatic polyimide copolymer comprising a fundamental skeleton consisting of recurring structural units of the formula (6) and recurring structural units of the formula (8) can be obtained by reacting 4,4'-bis(3-aminophenoxy)biphenyl of the formula (23) : in the presence of one or more diamine represented by the formula (24) : H 2 N-R-NH 2 wherein R is wherein n is an integer of 0, 1, 2, or 3 ; Q is a direct bond, -O-, -S-, -CO-, -SO 2 -, -CH 2 -, -C(CH 3 ) 2 - or -C(CF 3 ) 2 - and may be the same or different when two or more Q connects three or more aromatic rings each other ; with one or more aromatic tetracarboxylic dianhydride of the formula (25) : wherein R" is a tetravalent radical as defined above. Exemplary aromatic diamines used in the reaction and represented by the formula (26) : include m-phenylenediamine, o-phenylenediamine and p-phenylenediamine. Exemplary aromatic diamines used in the reaction and represented by the formula (27) : include benzidine, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 3,4'-diaminobenzophenone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 2,2'-bis(4-aminophenyl)propane, 2,2-bis(3-aminophenyl)propane, 2-(3-aminophenyl)-2-(4-aminophenyl)propane, 2,2-bis(3-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 2,2-bis(4-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, and 2-(3-aminophenyl)-2-(4-aminophenyl)propane. Exemplary aromatic diamines used in the reaction and represented by the formula (28) : include 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(3-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminobenzoyl)benzene, 1,3-bis(4-aminobenzoyl)benzene, 1,4-bis(4-aminobenzoyl)benzene. 1,3-bis(3-amino-α,α-dimethylbenzyl)benzene, 1,3-bis(4-amino-α,α-dimethylbenzyl)benzene, 1,4-bis(3-amino-α,α-dimethylbenzyl)benzene and 1,4-bis(4-amino-α,α-dimethylbenzyl)benzene. Exemplary aromatic diamines used in the reaction and represented by the formula (29) : include 4,4'-bis(4-aminophenoxy)biphenyl, 3,3'-bis(4-aminophenoxy)biphenyl, 3,4'-bis(3-aminophenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl]ketone, bis[4-(3-aminophenoxy)phenyl]ketone, bis[3-(3-aminophenoxy)phenyl]ketone, bis[4-(4-aminophenoxy)phenyl]sulfide, bis[4-(3-aminophenoxy)phenyl]sulfide, bis[3-(4-aminophenoxy)phenyl]sulfide, bis[3-(3-aminophenoxy)phenyl]sulfide, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]sulfone, bis[3-(4-aminophenoxy)phenyl]sulfone, bis[3-(3-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]ether, bis[4-(4-aminophenoxy)phenyl]ether, bis[3-(4-aminophenoxy)phenyl]ether, bis[3-(3-aminophenoxy)phenyl]ether, bis[4-(3-aminophenoxy)phenyl]methane, bis[4-(4-aminophenoxy)phenyl]methane, bis[3-(3-aminophenoxy)phenyl]methane, bis[3-(4-aminophenoxy)phenyl]methane, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[3-(3-aminophenoxy)phenyl]propane, 2,2-bis[3-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 2,2-bis[3-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, and 2,2-bis[3-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane. These aromatic diamines can be used singly or as a mixture. Representative aromatic tetracarboxylic dianhydrides which can be used as another monomer include pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)ether dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, 1,3-bis[4-(1,2-dicarboxy)phenoxy]benzene dianhydride, 1,4-bis[4-(1,2-dicarboxy)phenoxy]benzene dianhydride, 4,4'-bis[4-(1,2-dicarboxy)phenoxy]biphenyl dianhydride, 4,4'-bis[4-(1,2-dicarboxy)phenoxy]benzophenone dianhydride, bis[4- {4-(1,2-dicarboxy)phenoxy} phenyl]sulfone dianhydride, 2,2-bis[4- {4-(1,2-dicarboxy)phenoxy} phenyl]sulfone dianhydride, and 2,2-bis[4- {4-(1,2-dicarboxy)phenoxy} phenyl]-1,1,1,3,3,3-hexafluoropropane dianhydride. The aromatic polyimide having the formula (5),(6),(20) or (7) and the aromatic polyimide copolymer comprising the fundamental skeleton having recurring structural units consisting of 1-99 % by mol of the formula (6) and 1 ∼ 99 % by mol of the formula (8) are individually prepared from corresponding monomers above. In addition to the requisite aromatic diamine and aromatic dicarboxylic dianhydride, other aromatic diamines or aromatic tetracarboxylic dianhydrides can be used in combination so long as giving no adverse effect on the good properties of the resulting aromatic polyimide homopolymer and copolymer. Aromatic diamines which can be used in combination include those exemplified in preparing the liquid crystal type aromatic polyimide as aromatic diamines capable of being used simultaneously, and can be selected from these exemplified diamines depending upon the object. Aromatic tetracarboxylic dianhydride which can be used in combination can be suitably selected from the group exemplified in the aromatic tetracarboxylic dianhydride having the above formula (19). The aromatic polyimide homopolymer and aromatic polyimide copolymer obtained by using one or more aromatic diamines and one or more aromatic tetracarboxylic dianhydrides as monomer components also include a capped aromatic polyimide homopolymer and capped aromatic polyimide copolymer which have at the polymer chain end thereof an aromatic ring which is unsubstituted or substituted with a radical having no reactivity for amine amine and dicarboxylic anhydride. The capped homopolymer and capped copolymer can be prepared by reacting aromatic diamines of the above formulas (21), (22), (23), (24), (26), (27), (28), and (29) with tetracarboxylic dianhydrides of the above formula (19) and (25) in the presence of aromatic dicarboxylic anhydride of the formal (2) : wherein Z is a divalent radical as defined above, and/or aromatic monoamine of the formula (3) : V-NH 2 wherein V is a monovalent radical as defined above. The aromatic dicarboxylic anhydride and aromatic monoamine which can be used in the process include those which can be used for preparing homopolymers and copolymers of liquid crystal type aromatic polyimide. Any known process can be used for preparation of the above homopolymers and copolymers of aromatic polyimide and also for preparing the capped homopolymers and capped copolymers of aromatic polyimide which have an unsubstituted or substituted aromatic ring at the polymer chain end thereof. For example, these known processes can react aromatic tetracarboxylic dianhydrides with aromatic diamines in the presence of aromatic dicarboxylic anhydride such as phthalic anhydride and/or aromatic monoamine such as aniline to prepare aromatic polyimide having at the polymer chain end an unsubstituted aromatic ring and/or an aromatic ring substituted with a radical having no reacting for amine and dicarboxylic anhydride, that is When the melt-processable resin composition of the invention comprises liquid crystal type aromatic polyimide and aromatic polyimide, both or either one of these polymers can be capped at the polymer chain end thereof. Radicals derived from phthalic anhydride and aniline are preferred for the capping in particular. Next, aromatic polyether sulfone which can be used in the invention comprises a fundamental skeleton having one or more recurring structural units of the formula (11) : wherein X is a direct bond, Representative aromatic polysulfones have following recurring structural units. and Other aromatic polyether sulfones have following recurring structural units. Particularly typical aromatic polysulfones which have been marketed include polyether sulfone VICTREX PES (Trade Mark of ICI LTD.) having recurring structural units of the formula (30) : and polysulfone DUEL POLYSULFONE (Trade Mark of Union Carbide Corp.) having recurring structural units of the formula (31) : and polyaryl sulfone RADEL POLYSULFONE (Trade Mark of Union Carbide Corp.) having recurring structural units of the formula (32) : Polymerization degree of these aromatic polysulfones can be freely selected. Thus aromatic polysulfone having suitable melt viscosity for the desired blend can be arbitrarily selected. Next, aromatic polyetherimide which can be used in the invention comprises a fundamental skeleton having one or more recurring structural units represented by the formula (12): wherein X is: or and Y is: Exemplary aromatic polyetherimide include those having recurring structural units of the following formulas: The aromatic polyetherimide is marketed from G.E.Co. under the trade mark of Ultem-1000, Ultem-4000, Ultem-6000 etc. Next, aromatic polyamideimide which can be used in the invention comprises a fundamental skeleton having one or more recurring structural units of the formula (D): wherein Y is divalent radical having 6∼27 carbon atoms, and is particularly preferred to comprise a fundamental skeleton having recurring structural units of the formula (13): and/or the formula (14): The aromatic polyamideimide is marketed from Amoco Corp. under the trade mark of TORLON. Polymerization degree of the aromatic polyamideimide can be freely selected and thus the aromatic polyamideimide having suitable melt viscosity for the desired blend can be arbitrarily selected. Further, aromatic polyether ketone which can be used in the invention comprises a fundamental skeleton having one or more recurring structural units of the formula (15): and/or the formula (16): The melt-processable thermoplastic resin composition of the invention comprises one or more liquid crystal type aromatic polyimide selected from the group consisting of the liquid crystal type aromatic polyimide having recurring structural units of the above formula (1), the liquid crystal type aromatic polyimide having recurring structural units of the formula (4), the liquid crystal type aromatic polyimide copolymer comprising a fundamental skeleton having 1∼99 % by mol of the recurring structural units of the formula (1) and 99 ∼1 % by mol of the recurring structural units of the formula (4), and the liquid crystal type capped aromatic polyimide and the liquid crystal type capped aromatic polyimide copolymer which have at the polymer chain end an aromatic ring unsubstituted or substituted with a radical having no reactivity for amine and dicarboxylic anhydride, and one or more thermoplastic resin selected from the group consisting of other kinds of aromatic polyimide, aromatic polysulfone, aromatic polyetherimide, aromatic polyamideimide and aromatic polyether ketone. The thermoplastic resin composition comprises 0.1 ∼50 % by weight of the liquid crystal type aromatic polyimide and 99.9 ∼50 % by weight of the thermoplastic resin. The thermoplastic resin composition used in the invention has extremely low melt viscosity in a high temperature range of 300°C or more. The fluidization effect of the liquid crystal type aromatic polyimide in the invention is good even in a small amount. The lower limit of the polyimide in the resin composition is 0.1 % by weight, preferably 0.5 % by weight. The liquid crystal type aromatic polyimide has very excellent chemical resistance, flame retardance and mechanical strengths as compared with other heat resistant resin. On the other hand, the polyimide has disadvantages such as high anisotropy of mechanical strengths. Consequently, a high content of the liquid crystal type aromatic polyimide in the thermoplastic resin composition leads to unfavorably impair essential characteristics of polyimide. The amount of the liquid crystal type aromatic polyimide has an upper limit in the composition and is usually 50 % by weight or less, preferably 30 % by weight or less, more preferably 10 % by weight or less. On preparing the thermoplastic resin composition used in the invention, thermoplastic resin and liquid crystal type and the liquid crystal type aromatic polyimide can be blended by usually known methods, following methods are preferred: 1 ○ The thermoplastic resin and liquid crystal type aromatic polyimide are preblended with a mortar, Henschel mixer, drum blender, tumbling mixer, bal mill and ribbon blender. 2 ○ Thermoplastic resin is previously dissolved or suspended in an organic solvent, the liquid crystal type aromatic polyimide is added to the resulting solution or suspension and uniformly dissolved or suspended, and the solvent is successively removed from the mixture. 3 ○ When thermoplastic resin is aromatic polyimide, the liquid crystal type aromatic polyimide is suspended or dissolved in an organic solvent solution of polyamic acid which is a precursor of polyimide, the resulting mixture is heat-treated 100 ∼400 °C or chemically imidized with a common imidizing agent, and thereafter the solvent is removed by a known method. 4 ○ When thermoplastic resin is aromatic polyimide, an organic solvent solution of polyamic acid which is a precursor of the aromatic polyimide is mixed with an organic solvent solution of polyamic acid which is the precursor of the liquid crystal type aromatic polyimide, the resulting mixture heat-treated at 100∼400 °C or chemically imidized with common imidizing agent, and thereafter the solvent removed by a known method. The mixture of the liquid crystal type aromatic polyimide and thermoplastic resin thus obtained is used as intact for various processing methods such as injection molding, compression molding, transfer molding and extrusion forming. It is more preferred to use the mixture after melt kneading. Particularly in the preparation of the above composition, it is also a simple and effective method to mix powder and powder, pellet and pellet, or powder and pellet. Melt-kneading can be conducted with equipment commonly used for melt-kneading rubber and plastic, for example, hot rolls, Banbury mixer, Brabender and extruder. The melt-kneading temperature is set above the melt-flow temperature of the formulation and below the decomposition initiating temperature of the formulation. The temperature is usually 250∼420 °C, preferably 300∼400 °C. The melt-processable resin composition used in the invention can be preferably processed by injection molding or extrusion forming which provided a uniformly blended product and have high productivity. Other processing methods such as compression molding, transfer molding and sinter forming can also be employed. Other resin can also be formulated in a suitable amount depending upon the use of product so long as giving no adverse effect on the object of the invention. Other resins include, for example, thermoplastic resins such as polystyrene, polypropylene, polycarbonate, polyarylate, polyamide, polysulfone, polyether ketone, polyphenylene sulfide, polyamideimide, polyetherimide, modified polyphenylene oxide and other kinds of polyimide, and thermosetting resins. One or more solid lubricants such as molybdenum disulfide, graphait, boron nitride, lead monoxide and lead powder can be added to the polyimide resin composition of the invention. One or more reinforcements, for example, glass fiber, carbon fiber, aromatic polyamide fiber, potassium titanate fiber and glass beads can also be added to the composition. Further, other additives such as antioxidants, heat stabilizers, ultraviolet absorbers, flame retardants, flame retarding adjuvants, antistatic agents and colorants can also be added to the composition. The present invention will hereinafter be described in detail by way of examples. In these examples, properties were measured by the following methods. Inherent viscosity : 0.5g of polyimide powder was dissolved by heating in 100 mℓ of a p-chlorophenol/phenol mixture in a weight ratio of 90/10. The solution was cooled to 35°C and viscosity was measured. Glass transition temperature (Tg): Measured by DSC (Shimadzu DT-40 series, DSC-41M). 5% weight loss temperature : Measured by DTA-Tg (Shimadzu DT-40 series, s DSC-40M) in the air. Synthesis Example 1 To a reaction vessel equipped with a stirrer, reflux condenser, water separator and nitrogen inlet tube, 5.29 kg (10.0 mols) of 1,3-bis [4-(4-aminophenoxy)-α,α-dimethylbenzyl)benzene, 2.094 kg (9.6 moles) of pyromellitic dianhydride, 138g (1.5 mols) of γ-picoline and 23.0 kg of m-cresol were charged. The mixture was heated to 145 °C with stirring in a nitrogen atmosphere while distilling out about 340 g of water. The reaction was further continued at 140-150°C for 4 hours. The reaction mixture was cooled to the room temperature and poured into 81.2 kg of methyl ethyl ketone. The precipitated polyimide was filtered, washed with methyl ethyl ketone, predried in a nitrogen atmosphere at 50 °C for 24 hours, and dried at 200 °C for 6 hours to obtain 6.85 kg (97.3 % yield) of polyimide powder. The polyimide powder had an inherent viscosity of 0.49 dℓ /g and 5 % weight loss temperature of 525 °C in the air. Two heat absorption peaks were observed at 274 °C and 294°C in DSC measurement. Synthesis Examples 2∼6 The same procedures as described in Synthesis Example 1 were carried out by using various diamines and tetracarboxylic dianhydrides which are illustrated in Table 1 to obtain various kinds of polyimide powder. Table 1 illustrates synthesis conditions, inherent viscosity, glass transition temperature and 5 % weight loss temperature of the polyimide powder. Synthesis Example No. Aromatic diamine kg(mol) Tetracarboxylic dianhydride kg(mol) η (dℓ/g) Tg (°C ) Td 5% (°C) - 2 m-BP 3.68 (10.0) PMDA 2.072 (9.5) 0.45 245 560 - 3 m-BS 4.32 (10.0) PMDA 2.094 (9.6) 0.50 256 540 - 4 mBAPP 4.11 (10.0) PMDA 2.116 (9.7) 0.55 218 528 - 5 m-APS 4.01 (10.0) BTDA 3.093 (9.6) 0.49 195 524 - 6 m-BP 3.68 (10.0) OPDA 2.947 (9.5) 0.43 199 542 Synthesis Example 7 The same procedures as described in Synthesis Example 1 were carried out except that 118.49 g(0.80g) of phthalic anhydride was added in the reaction. The polyimide powder thus obtained was 6.93 kg (97.0 % yield) and had an inherent viscosity of 0.49 dℓ /g and 5 % weight loss temperature of 536 °C in the air. Two heat absorption peaks were observed at 274 °C and 295°C by DSC measurement. Synthesis Example 8 The same procedures as described in Synthesis Example 1 were carried out except that 158.54 g (0.80 mol) of 1,8-naphthalene dicarboxylic anhydride was added in the reaction. The polyimide powder thus obtained was 7.02 kg (97.0 % yield) and had an inherent viscosity of 0.50 d ℓ/g and 5 % weight loss temperature of 538 °C in the air. Two heat absorption peaks were observed at 275°C and 297°C by DSC measurement. Synthesis Example 9 The same procedures as described in Synthesis Example 2 were carried out except that 148.11 g (1.00 mol) of phthalic anhydride was added in the reaction to obtain polyimide powder. Table 2 illustrates synthesis conditions, inherent viscosity, glass transition temperature and 5 % weight loss temperature of the polyimide powder obtained. Synthesis Example 10 The same procedures as described in Synthesis Example 3 were carried out except that 118.49 g (0.80 mol) of phthalic anhydride was added in the reaction to obtain polyimide powder. Table 2 illustrates synthesis conditions, inherent viscosity, glass transition temperature, and 5 % weight loss temperature of the polyimide powder obtained. Synthesis Example 11 The same procedures as described in Synthesis Example 4 were carried out except that 88.87 g (0.60 mol) of phthalic anhydride was added in the reaction to obtain polyimide powder. Table 2 illustrates synthesis conditions, inherent viscosity, glass transition temperature, and 5 % weight loss temperature of the polyimide powder obtained. Synthesis Example 12 The same procedures as described in Synthesis Example 2 were carried out except that 198.18 g (1.00 mol) of 1,8-naphthalenedicarboxylic anhydride was added in the reaction to obtain polyimide powder. Table 2 illustrates synthesis conditions, inherent viscosity, glass transition temperature, and 5 % weight loss temperature of the polyimide powder obtained. Synthesis Example No. Aromatic diamine kg(mol) Tetracarboxylic dianhydride kg(mol) η (dℓ/g) Tg (°C) Td 5% (°C) - 9 m-BP 3.68 (10.0) PMDA 2.072 (9.5) 0.46 244 562 - 10 m-BS 4.32 (10.0) PMDA 2.094 (9.6) 0.49 254 548 - 11 mBAPP 4.11 (10.0) PMDA 2.116 (9.7) 0.54 218 534 - 12 m-BP 3.68 (10.0) PMDA 2.072 (9.5) 0.47 245 560 Synthesis Example 13 To a reaction vessel equipped with a stirrer, reflux condenser, water separator and nitrogen inlet tube, 3.50 kg(9.5 mols) of 4,4'-bis(3-aminophenoxy)biphenyl, 2.18 kg (10.0 mols) of pyromellitic dianhydride, 140 g (1.5 mols) of γ-picoline, 93.0 g (1.0 mol) of aniline and 23.0 kg of m-cresol were charged. The mixture was heated to 145°C with stirring in a nitrogen atmosphere while distilling out about 360 g of water. The reaction was further continued at 140 ∼150 °C for 4 hours. The reaction mixture was cooled to the room temperature and poured into 81.2 kg of methyl ethyl ketone. The precipitated polyimide was filtered, washed with methyl ethyl ketone, predried at 50°C for 24 hours in a nitrogen atmosphere and dried at 200 °C for 6 hours to obtain 5.25 kg (97.0 % yield) of polyimide powder. The polyimide obtained had an inherent viscosity of 0.46 dℓ /g, glass transition temperature of 247 °C and 5 % weight loss temperature of 555 °C in the air. Synthesis Example 14 The same procedures as described in Synthesis Example 13 were carried out by using 107.15 g (1.0 mol) of p-toluidine in place of 93.0 g (1.0 mol) of aniline to obtain 52.6 kg (97.0 % yield) of polyimide powder. The polyimide powder had an inherent viscosity of 0.47 dℓ /g, glass transition temperature of 247 °C and 5 % weight loss temperature of 552 °C in the air. Synthesis Example 15 The same procedures as described in Synthesis Example 13 were carried out by using 5.07 kg (9.6 mol) of 1,3-bis[4-(4-aminophenoxy)-α,α-dimethylbenzyl]benzene in place of 3.50 kg (9.5 mol) of 4,4'-bis(3-aminophenoxy)biphenyl to obtain 6.76 kg (97.0 % yield) of polyimide powder. The polyimide powder had an inherent viscosity of 0.47 dℓ /g and 5 % weight loss temperature of 532 °C. Two heat absorption peaks were observed at 274 °C and 295°C by DSC measurement. Synthesis Example 16 The same procedures as described in Synthesis Example 15 were carried out by using 85.72 g (0.8 mol) of p-toluidine in place of 74.4 g (0.8 mol) of aniline to obtain 6.77 kg (97.0 % yield) of polyimide powder. The polyimide powder had an inherent viscosity of 0.48 dℓ /g and 5 % weight loss temperature of 535 °C. Two heat absorption peaks were observed at 274 °C and 297°C by DSC measurement. Synthesis Example 17 The same procedures as described in Synthesis Example 13 were carried out by using 3.98 kg (9.7 mol) of 2,2-bis[4-(3-aminophenoxy) phenyl]propane in place of 3.50 kg (9.5 mol) of 4,4'-bis(3-aminophenoxy) biphenyl to obtain 5.70 kg (97.3 % yield) of polyimide powder. The polyimide powder had an inherent viscosity of 0.54 dℓ /g, glass transition temperature of 217 °C and 5 % weight loss temperature of 534 °C in the air. Synthesis Example 18 To a reaction vessel equipped with a stirrer, reflux condenser, water separator and nitrogen inlet tube, 2.123 kg (10.0 mol) of 3,3'-diaminobenzophenone, 3.093 kg (9.6 mol) of 3,3',4,4'-benzophenonetetrac arboxylic dianhydride, 138 g (1.5 mol) of γ-picoline and 20.9 kg of m-cresol were charged. The mixture was heated to 145 °C with stirring in a nitrogen atmosphere while distilling out about 340 g of water. The reaction was further carried out at 140 ∼150 °C for 4 hours. The reaction mixture was cooled to the room temperature and poured into 81.2 kg of methyl ethyl ketone. Precipitated polyimide was filtered, washed with methyl ethyl ketone, predried at 50°C for 24 hours in a nitrogen atmosphere and dried at 200 °C for 6 hours to obtain 4.74 kg (97.3 % yield) of polyimide powder. The polyimide powder had an inherent viscosity of 0.4 dℓ /g, glass transition temperature of 240 °C and 5 % weight loss temperature of 532 °C in the air. Synthesis Example 19 The same procedures as described in Synthesis Example 18 were carried out except that 118.49 g (0.80 mol) of phthalic anhydride was added in the reaction to obtain 4.88 kg (98.0 % yield) of polyimide powder. The polyimide powder had an inherent viscosity of 0.48 dℓ /g, glass transition temperature of 245 °C and 5 % weight loss temperature of 550 °C. Synthesis Example 20 The same procedures as described in Synthesis Example 18 were carried out except that 158.54 (0.80 g ) of 1,8-naphthalenedicarboxylic anhydride was added in the reaction to obtain 4.86 kg (97.0 % yield) of polyimide powder. The polyimide powder had on inherent viscosity of 0.49 dl/g, glass transition temperature of 247°C and 5 % weight loss temperature of 538 °C in the air. Synthesis Example 21 To a reaction vessel equipped with a stirrer, reflux condenser, water separator and nitrogen inlet tube, 2.038 kg (9.6 mol) of 3,3'-diaminobenzophenone, 3.222 kg (10.0 mol) of 3,3',4,4'-benzophenonetetrac arboxylic dianhydride, 138 g (1.5 mol) of γ-picoline, 74.50 g (0.8 mol) of aniline and 20.9 kg of m-cresol were charged. The mixture was heated to 145 °C with stirring in a nitrogen atmosphere while distilling out about 340 g of water. The reaction was further carried out at 140 ∼150 °C for 4 hours. The reaction mixture was cooled to the room temperature and poured into 81.2 kg of methyl ethyl ketone. Precipitated polyimide was filtrated, washed with methyl ethyl ketone, predried at 50 °C for 24 hours in a nitrogen atmosphere and dried at 200 °C for 6 hours to obtain 4.74 Kg (97.3 % yield) of polyimide powder. The polyimide powder had an inherent viscosity of 0.48 dℓ /g, glass transition temperature of 240 °C and 5 % weight loss temperature of 548 °C in the air. Synthesis Example 22 The same procedures as described in Synthesis Example 21 were carried out by using 85.72 g (0.8 mol) of p-toluidine in place of 74.50 g (0.8 mol) of aniline to obtained 4.85 kg (97.5 % yield) of polyimide powder. The polyimide powder had an inherent viscosity of 0.49 d ℓ/g, glass transition temperature of 244 °C and 5 % weight loss temperature of 545 °C in the air. Synthesis Example 23 To a reaction vessel equipped with a stirrer, reflux condenser, water separator and nitrogen inlet tube, 3.316 kg (9.00 mol) of 4,4'-bis(3-aminophenoxy)biphenyl, 0.200kg (1.00 mol) of 4,4'-diaminodiphenylether, 2.072 kg (9.50 mol) of pyromellitic dianhydride, 140 g (1.5 mol) of γ-picoline and 22.4 kg of m-cresol were charged. The mixture was heated to 145°C with stirring in a nitrogen atmosphere while distilling out about 340 g of water. The reaction was further continued for 4 hours at 140 ∼ 150 °C. Thereafter, the reaction mixture was cooled to the room temperature and poured into 56.1 Kg of methyl ethyl ketone. The precipitated powder was filtered, washed with methyl ethyl ketone, predried at 50 °C for 24 hours in a nitrogen atmosphere and dried at 200 °C for 6 hours to obtain 5.09 Kg (97.0 & yield) of polyimide powder. The polyimide powder had an inherent viscosity of 0.50 dℓ /g, glass transition temperature of 250 °C and 5 % weight loss temperature of 542 °C in the air. Tc and Tm were not observed. Synthesis Example 24 The same procedures as described in Synthesis Example 23 were carried out except that 3.316 Kg (9.00 mols) of 4,4'-bis(3-aminophenoxy) biphenyl, 0.200 kg (1.00 mol) of 4,4'-diaminodiphenyl ether and 2.072 Kg (9.50 mols) of pyromellitic dianhydride were replaced by 2.579 Kg (7.00 mols) of 4,4'-bis(3-aminophenoxy)biphenyl, 1.297 Kg(3.00 mols) of bis[4-(3-aminophenoxy)phenyl]sulfone and 2.094 Kg (9.60 mols) of pyromellitic dianhydride. Polyimide powder thus obtained was 5.51 Kg (98.0 % yield) and had an inherent viscosity of 0.51 dℓ /g, glass transition temperature of 253 °C and 5 % weight loss temperature of 539 °C in the air. Tc and Tm were not observed. Synthesis Example 25 The same procedures as described in Synthesis Example 23 were carried out except that 148.11 kg (1.00 mol) of phthalic anhydride was added to the reaction. Polyimide powder thus obtained was 5.26 kg (97.8 % yield) and had an inherent viscosity of 0.50 dℓ /g, glass transition temperature of 254 °C and 5 % weight loss temperature of 546 °C in the air. Tc and Tm were not observed. Synthesis Example 26 The same procedures as described in Synthesis Example 23 were carried out except that 195.68 Kg (1.00 mol) of 1,8-naphthalenedicarboxylic anhydride was added to the reaction. Polyimide powder thus obtained was 5.31 Kg (98.0 % yield) and had an inherent viscosity of 0.49 dℓ /g, glass transition temperature of 250 °C and 5 % weight loss temperature of 543 °C in the air. Tc and Tm were not observed. Synthesis Example 27 To a reaction vessel equipped with a stirrer, reflux condenser and nitrogen inlet tube, 3.150 kg (8.55 mols) of 4,4'-bis(3-aminophenoxy) biphenyl, 0.190 kg (0.95 mol) of 4,4'-diaminodiphenyl ether, 2.18 kg (10.0 mols) of pyromellitic dianhydride, 140 g (1.5 mols) of γ-picoline and 93.12 g of aniline and 23.0 kg m-cresol were charged. The mixture was heated to 145°C with stirring in a nitrogen atmosphere while distilling out about 360g of water. The reaction was further continued for 4 hours at 140∼150 °C. Thereafter, the reaction mixture was cooled to the room temperature and poured into 81.2 kg of methyl ethyl ketone. The precipitated powder was filtered, washed with methyl ethyl ketone, predried at 50 °C for 24 hours in a nitrogen atmosphere and dried at 200 °C for 6 hours to obtain 5.16 kg (98.2 % yield) of polyimide powder. The polyimide powder had an inherent viscosity of 0.49 dℓ /g, glass transition temperature of 256 °C and 5 % weight loss temperature of 549 °C in the air. Tc and Tm were not observed. Synthesis Example 28 The same procedures as described in Synthesis Example 27 were carried out except that 93.12 g (1.0 mol) of aniline was replaced by 107.15 g (1.0 mol) of p-toluidine. Polyimide powder thus obtained was 5.16 Kg (98.0 % yield) and had an inherent viscosity of 0.49 dℓ /g, glass transition temperature of 255 °C and 5 % weight loss temperature of 547 °C in the air. Synthesis Example 29 The same procedures as described in Synthesis Example 27 were carried out except that 3.150 kg (8.55 mols) of 4,4'-bis(3-aminophenoxy) biphenyl, 0.190 kg (0.95 mol) of 4,4'-diaminodiphenyl ether and 93.12 g (1.0 mol) of aniline were replaced by 2.476 kg (6.72 mols) of 4,4'-bis(3-aminophenoxy)biphenyl, bis(3-aminophenoxy)biphenyl, 1.246 kg (2.88 mols) of and 74.50 (0.80 mol) of aniline. Polyimide powder thus obtained was 5.49 kg (97.8 % yield) and had an inherent viscosity of 0.50 dℓ /g, glass transition temperature of 251 °C and 5 % weight loss temperature of 544 °C in the air. Synthesis Example 30 The same procedures as described in Synthesis Example 29 were carried out except that 74.50 g (0.80 mol) was replaced by 85.72 g (0.80 mol) of p-toluidine. Polyimide powder thus obtained was 5.52 kg (98.0 % yield) and had an inherent viscosity of 0.50 dℓ /g, glass transition temperature of 252 °C and 5 % weight loss temperature of 540 °C in the air. Synthesis Example 31 To a reaction vessel equipped with a thermometer, reflux condenser and a stirrer, 200 g of N,N-dimethylformamide (DMF), 65g (0.409 mol) of 3,4-difluoronitrobenzene, 69.1g (0.199 mol) of 1,3-bis(4-hydroxycumyl) benzene and 33.1 g (0.239 mol) of potassium carbonate were charged and warmed to 80°C with stirring. After aging the mixture at 80°C for 6 hours, inorganic salts was removed by filtration. The filtrate was mixed with 50 mℓ of water and cooled to the room temperature. The precipitated crystal was filtered and slugged with isopropyl alcohol to obtain 129.4 g (97% yield) of 1,3-bis[4-(4-nitro-6-fluorophenoxy)-α,α-dimethylbenzyl]benzene having a melting point of 150.7 ∼151.8 °C. Successively, to a reduction vessel equipped with a thermometer, reflux condenser and stirrer, 115g (0.184 mol) of 1,3-bis[4-(4-nitro-6-fluorophenoxy)-α,α-dimethylbenzyl]benzene, 250g of isopropyl alcohol and 4.8 g of 5%-Pd/c having a moisture content of 50% were charged and reacted at 70 ∼80°C for 4 hours in a hydrogen atmosphere. After finishing the reaction, the catalyst was filtered off and the filtrate was concentrated under reduced pressure to obtain 84.2 g (81% yield) of 1,3-bis[4-(4-amino-6-fluorophenoxy)-α,α-dimethylbenzyl]benzene as a light yellow crystal having a melting point of 130.4 -∼132.9. Elementary analyses (C 36 H 34 N 2 O 2 F 2 ) C H N F Calculated (%) 76.52 6.07 5.96 6.73 Found (%) 76.55 6.11 5.91 6.77 Further, to a reaction vessel equipped with a stirrer, reflux condenser, water separator and nitrogen inlet tube, 56.47 g (0.1 mol) of 1,3-bis[4-(4-amino-6-fluorophenoxy)-α,α-dimethylbenzyl]benzene, 21.38 (0.098 mol) of pyromellitic dianhydride, 0.592 (0.004 mol) of phthalic anhydride, 1.40 g of γ-picoline and 311.4 g of m-cresol were charged and heated to 150°C with stirring in a nitrogen atmosphere and reacted at 150°C for 4 hours while distilling out about 3.6 m ℓ of water. After finishing the reaction, the reaction mixture was cooled to the room temperature and poured into about 2.0 litre of methyl ethyl ketone. Precipitated powder was filtered, washed with methyl ethyl ketone, and dried at 50 °C for 24 hours in the air and at 180 °C for 4 hours under reduced pressure to obtain 72.56 g (97.0 % yield) of polyimide powder. The polyimide powder thus obtained has an inherent viscosity of 0.50 dℓ /g, glass transition temperature of 186 °C and melting point of 350 °C. Further, 30 parts of weight of the polyimide powder was mixed with 70 parts by weight of marketed polyether sulfone VICTREX PES 4100P (Trade Mark of ICI Ltd.) and measured melt viscosity at 370 °C after residence time of 5 minutes. Following results were obtained. Polyether sulfone 5700 poise Polyether sulfone/Polyimide 3350 poise Melt viscosity was greatly reduced by mixing the thus obtained polyimide with polyether sulfone. The strand obtained was oriented to the direction of extrusion and essential property of liquid crystal type high polymers such as fibrillated structure was observed. Synthesis Example 32 To a reaction vessel equipped with a thermometer, reflux condenser and a stirrer, 200 g of N,N-dimethylformamide (DMF), 10g of toluene, 80g (0.466 mol) of 2-chloro-6-nitrotoluene, 78.8g (0.227 mol) of 1,3-bis (4-hydroxycumyl)benzene and 37.7 g (0.273 mol) of potassium carbonate were charged and heated to 150°C with stirring. After aging the mixture at 150 °C for 7 hours, the mixture was cooled to 90°C and inorganic salts was removed by filtration. The filtrate was mixed with 56 mℓ of water and cooled to the room temperature. The precipitated crystal was filtered and slugged with isopropyl alcohol to obtain 133.9 g (96% yield) of 1,3-bis[4-(4-nitro-6-methylphenoxy)-α,α-dimethylbenzyl]benzene having a melting point of 116.3 ∼117.6 °C. Successively, to a reduction vessel equipped with a thermometer, reflux condenser and stirrer, 120g (0.195 mol) of 1,3-bis[4-(4-nitro-6-methylphenoxy)-α,α-dimethylbenzyl]benzene, 400g of isopropyl alcohol and 5 g of 5%-Pd/c having a moisture content of 50% were charged and reacted at 70 ∼80°C for 4 hours in a hydrogen atmosphere. After finishing the reaction, the catalyst was filtered off and the filtrate was concentrated under reduced pressure to obtain 89.0 g (82% yield) of 1,3-bis[4-(4-amino-6-methylphenoxy)-α,α-dimethylbenzyl]benzene as a light yellow crystal having a melting point of 118.1 ∼118.2. Elementary analyses (C 38 H 40 N 2 O 2 F 2 ) C H N Calculated (%) 81.98 7.24 5.03 Found (%) 82.18 7.22 5.15 The same procedures as described in Synthesis Example 31 were carried out by using 55.68 g (0.1 mol) of 1,3-bis[4-(4-amino-6-methylphenoxy)-α,α-dimethylbenzyl]benzene to obtain 71.29 g (96.3 % yield) of polyimide powder. The polyimide powder had an inherent viscosity of 0.51 dℓ /g and glass transition temperature of 185°C. Further, 30 parts by weight of the polyimide powder was mixed with 70 parts by weight of marketed polyether sulfone VICTREX PES 4100P (Trade Mark of ICI Ltd.) and measured melt viscosity at 370 °C after residence time of 5 minutes. Following results were obtained. Polyether sulfone 5700 poise Polyether sulfone/Polyimide 3230 poise Melt viscosity was greatly reduced by mixing the thus obtained polyimide with polyether sulfone. The strand obtained was oriented to the direction of extrusion and essential property of liquid crystal type high polymers such as fibrillated structure was observed. Synthesis Example 33 To a reaction vessel equipped with a thermometer, reflux condenser and a stirrer, 700 m ℓ of N,N-dimethylformamide (DMF), 30 m ℓ of toluene, 87g (0.386 mol) of 2-chloro-5-nitrobenzotrifluoride, 63.6g (0.184 mol) of 1,3-bis(4-hydroxycumyl)benzene and 53.3 g (0.386 mol) of potassium carbonate were charged and heated to 110°C with stirring. After aging the mixture at 110°C for 4 hours, the mixture was cooled to 80°C and inorganic salts was removed by filtration. The filtrate was mixed with 30 m ℓ of water and cooled to the room temperature. The precipitated crystal was filtered and slugged with isopropyl alcohol to obtain 120 g (90% yield) of 1,3-bis[4-(4-nitro-6-trifluoromethylphenoxy)-α,α-dimethylbenzyl]benzene having a melting point of 127.4 ∼128.4 °C. Successively, to a reduction vessel equipped with a thermometer, reflux condenser and stirrer, 90g (0.124 mol) of 1,3-bis[4-(4-nitro-6-trifluoromethylphenoxy)-α,α-dimethylbenzyl]benzene, 500 mℓ of methyl cellosolve and 5 g of 5%-Pd/c having a moisture content of 50% were charged and reacted at 70∼80°C for 4 hours in a hydrogen atmosphere. After finishing the reaction, the catalyst was filtered off and the filtrate was concentrated under reduced pressure to obtain 73.4 g (89% yield) of 1,3-bis[4-(4-amino-6-trifluoromethylphenoxy)-α,α-dimethylbenzyl]benzene as a light yellow crystal having a melting point of 118.5 ∼119.2. Elementary analyses (C 38 H 34 N 2 O 2 F 2 ) C H N F Calculated (%) 68.67 5.16 4.21 17.15 Found (%) 68.78 5.22 4.15 17.01 Further, to a reaction vessel equipped with a stirrer, reflux condenser, water separator and nitrogen inlet tube, 66.47 g (0.1 mol) of 1,3-bis[4-(4-amino-6-trifluoromethylphenoxy)-α,α-dimethylbenzyl]benz ene, 21.38 (0.098 mol) of pyromellitic dianhydride, 0.592 (0.004 mol) of phthalic anhydride, 1.40 g of γ-picoline and 351.4 g of m-cresol were charged and heated to 150°C with stirring in a nitrogen atmosphere and reacted at 150°C for 4 hours while distilling out about 3.6 mℓ of water. After finishing the reaction, the reaction mixture was cooled to the room temperature and poured into about 2.0 litre of methyl ethyl ketone. Precipitated powder was filtered, washed with methyl ethyl ketone, and dried at 50 °C for 24 hours in the air and 180°C for 4 hours under reduced pressure to obtain 83.22 g (98.1 % yield) of polyimide powder. The polyimide powder thus obtained had an inherent viscosity of 0.45 dℓ /g, glass transition temperature of 186 °C and melting point of 196 °C . Following results were obtained on the elementary analyses. C H N F Calculated (%) 68.08 3.82 3.31 13.46 Found (%) 67.86 3.75 3.40 13.02 A polyimide film having a thickness of 50 µm was prepared by pressing the polyimide power at 350 °C under pressure of 300 psi. The film had dielectric constant of 3.02 at 60Hz, 2.99 at 3 KHz 2.96 at 1 MHz. Further, 30 parts by weight of the polyimide powder was mixed with 70 parts by weight of marketed polyether sulfone VICTREX PES 4100P (Trade Mark of ICI Ltd.) and measured melt viscosity at 350 °C and 370°C after residence time of 5 minutes. Following results were obtained. 350°C 370°C Polyether sulfone 12000 poise 5700 poise Polyether sulfone/Polyimide 5250 poise 3350 poise Melt viscosity was greatly reduced by mixing the thus obtained polyimide with polyether sulfone. The strand obtained was oriented to the direction of extrusion and essential property of liquid crystal type high polymers such as fibrillated structure was observed. Examples 1 ∼ 8 The polyimide powder obtained in Synthesis Examples 2 and 3 was dryblended with the liquid crystal type polyimide powder obtained in Synthesis Example 1 in various proportions illustrated in Table 3. Melt viscosity of the composition obtained was measured with a Koka type flow tester (Shimadzu CFT-500) under 100 Kg load by using an oriffice of 0.1 cm in diameter and 1 cm in length. Results are illustrated in Table 3. Comparative Examples 1∼ 8 Compositions outside the scope of the present invention were prepared and melt viscosity of these compositions was measured by the same procedures as described in Examples 1 ∼ 8. Results are illustrated in Table 3. No. Polyimide L.C. type polyimide Synthesis Example 1 wt. parts Flow tester Synthesis Example No. wt. parts temperature (°C) Melt viscosity (poise) Comp. Example 1 2 100 0 400 5000 Example 1 2 90 10 400 4060 Example 2 2 70 30 400 2070 Comp. Example 2 2 40 60 400 970 Comp. Example 3 2 100 0 420 3100 Example 3 2 90 10 420 2510 Example 4 2 70 30 420 1220 Comp. Example 4 2 40 60 420 620 Comp. Example 5 3 100 0 400 5500 Example 5 3 90 10 400 4420 Example 6 3 70 30 400 2150 Comp. Example 6 3 40 60 400 980 Comp. Example 7 3 100 0 420 3400 Example 7 3 90 10 420 2680 Example 8 3 70 30 420 1300 Comp. Example 8 3 40 60 420 650 Note) L.C. type polyimide: Liquid crystal type polyimide Examples 9∼16 The polyimide powder obtained in Synthesis Examples 4 and 5 was dryblended with the liquid crystal type polyimide powder obtained in Synthesis Example 1 in various proportions illustrated in Table 4. Melt viscosity of the composition obtained was measured with a Koka type flow tester (Shimadzu CFT-500) under 100 Kg load by using an oriffice of 0.1 cm in diameter and 1 cm in length. Results are illustrated in Table 4. Comparative Examples 9∼ 16 Compositions outside the scope of the present invention were prepared and melt viscosity of these compositions was measured by the same procedures as carried out in Examples 9 ∼ 16. Results are illustrated in Table 4. No. Polyimide L.C. type polyimide Synthesis Example 1 wt. part Flow tester Synthesis Example No. wt. part temperature (°C) Melt viscosity (poise) Comp. Example 9 4 100 0 380 4240 Example 9 4 90 10 380 3480 Example 10 4 70 30 380 1700 Comp. Example 10 4 40 60 380 820 Comp. Example 11 4 100 0 400 2500 Example 11 4 90 10 400 1860 Example 12 4 70 30 400 1020 Comp. Example 12 4 40 60 400 500 Comp. Example 13 5 100 0 360 4800 Example 13 5 90 10 360 3920 Example 14 5 70 30 360 1860 Comp. Example 14 5 40 60 360 890 Comp. Example 15 5 100 0 380 2600 Example 15 5 90 10 380 1960 Example 16 5 70 30 380 1080 Comp. Example 16 5 40 60 380 520 Note) L.C. type polyimide; Liquid crystal type polyimide Examples 17 ∼20 The polyimide powder obtained in Synthesis Example 6 was dryblended with the liquid crystal type polyimide powder obtained in Synthesis Example 1 in various proportions illustrated in Table 5. Melt viscosity of the composition obtained was measured with a Koka type flow tester (Shimadzu CFT-500) under 100 Kg load by using an oriffice of 0.1 cm in diameter and 1 cm in length. Results are illustrated in Table 5. Comparative Examples 17 ∼ 20 Compositions outside the scope of the present invention were prepared and melt viscosity of these compositions was measured by the same procedures as carried out in Examples 17∼ 20. Results are illustrated in Table 5. No. Polyimide L.C. type polyimide Sythesis Example 1 wt.part Flow tester Synthesis Example No. wt. part temperature (°C) Melt viscosity (poise) Example 17 6 90 10 380 2960 Example 18 6 70 30 380 1620 Comp. Example 18 6 40 60 380 730 Comp. Example 19 6 100 0 400 2260 Example 19 6 90 10 400 1980 Example 20 6 70 30 400 1000 Comp. Example 20 6 40 60 400 430 Note: L.C. type polyimide--Liquid crystal type polyimide Examples 21 ∼28 The polyimide powder obtained in Synthesis Examples 9 and 10 was dryblended with the liquid crystal type polyimide powder obtained in Synthesis Example 7 in various proportions illustrated in Table 6. Melt viscosity of the composition obtained was measured with a Koka type flow tester (Shimadzu CFT-500) under 100 Kg load by using an oriffice of 0.1 cm in diameter and 1 cm in length. Results are illustrated in Table 6. Comparative Examples 21 ∼ 28 Compositions outside the scope of the invention were prepared and melt viscosity of these compositions was measured by the same procedures as carried out in Examples 21∼ 28. Results are illustrated in Table 6. No. Polyimide L.C. type polyimide Synthesis Example 7 part Flow tester Synthesis Example No. wt. part temperature (°C) Melt viscosity (poise) Comp. Example 21 9 100 0 400 4800 Example 21 9 90 10 400 3960 Example 22 9 70 30 400 1980 Comp. Example 22 9 40 60 400 890 Comp. Example 23 9 100 0 420 3080 Example 23 9 90 10 420 2490 Example 24 9 70 30 420 1280 Comp. Example 24 9 40 60 420 650 Comp. Example 25 10 100 0 400 5300 Example 25 10 90 10 400 4340 Example 26 10 70 30 400 2100 Comp. Example 26 10 40 60 400 950 Comp. Example 27 10 100 0 420 3320 Example 27 10 90 10 420 2600 Example 28 10 70 30 420 1260 Comp. Example 28 10 40 60 420 620 Note) L.C. type polyimide :Liquid crystal type polyimide Examples 29 ∼32 The polyimide powder obtained in Synthesis Examples 11 was dryblended with the liquid crystal type polyimide powder obtained in Synthesis Example 7 in various proportions illustrated in Table 7. Melt viscosity of the composition obtained was measured with a Koka type flow tester (Shimadzu CFT-500) under 100 Kg load by using an oriffice of 0.1 cm in diameter and 1 cm in length. Results are illustrated in Table 7. Comparative Examples 29 ∼ 32 Compositions outside the scope of the invention were prepared and melt viscosity of these compositions was measured by the same procedures as carried out in Examples 29∼ 32. Results are illustrated in Table 7. No. Polyimide L.C. type polyimide Synthesis Example 7 wt.parts Flow tester Synthesis Example No. wt. parts temperature (°C) Melt viscosity (poise) Comp. Example 29 11 100 0 380 4110 Example 29 11 90 10 380 3400 Example 30 11 70 30 380 1620 Comp. Example 30 11 40 60 380 780 Comp. Example 31 11 100 0 400 2480 Example 31 11 90 10 400 1800 Example 32 11 70 30 400 1030 Comp. Example 32 11 40 60 400 480 Note) L.C. type polyimide: Liquid crystal type polyimide Examples 33 ∼ 36 The polyimide powder obtained in Synthesis Example 12 was dryblended with the liquid crystal type polyimide powder obtained in Synthesis Example 8 in various proportions illustrated in Table 8. Melt viscosity of the composition obtained was measured with a Koka type flow tester (Shimadzu CFT-500) under 100 Kg load by using an oriffice of 0.1 cm in diameter and 1 cm in length. Results are illustrated in Table 8. Comparative Examples 33 ∼ 36 Compositions outside the scope of the invention were prepared and melt viscosity of these compositions was measured by the same procedures as carried out in Examples 33∼ 36. Results are illustrated in Table 8. No. Polyimide L.C. type polyimide Synthesis Example 8 wt. parts Flow tester Synthesis Example No. wt. parts temperature (°C) Melt viscosity (poise) Comp. Example 33 12 100 0 400 4780 Example 33 12 90 10 400 3950 Example 34 12 70 30 400 1950 Comp. Example 34 12 40 60 400 870 Comp. Example 35 12 100 0 420 3090 Example 35 12 90 10 420 2500 Example 36 12 70 30 420 1290 Comp. Example 36 12 40 60 420 660 Note) L.C. type polyimide: Liquid crystal type polyimide Examples 37 ∼44 The polyimide powder obtained in Synthesis Examples 13 and 17 was dryblended with the liquid crystal type polyimide powder obtained in Synthesis Example 15 in various proportions illustrated in Table 9. Melt viscosity of the composition obtained was measured with a Koka type flow tester (Shimadzu CFT-500) under 100 Kg load by using an oriffice of 0.1 cm in diameter and 1 cm in length. Results are illustrated in Table 9. Comparative Examples 37 ∼ 44 Compositions outside the scope of the invention were prepared and melt viscosity of these compositions was measured by the same procedures as carried out in Examples 37∼44. Results are illustrated in Table 9. No. Polyimide L.C. type polyimide Synthesis Example 15 wt. part Flow tester Synthesis Example No. wt. part temperature (°C) Melt viscosity (poise) Comp. Example 37 13 100 0 400 5600 Example 37 13 90 10 400 4300 Example 38 13 70 30 400 2160 Comp. Example 38 13 40 60 400 930 Comp. Example 39 13 100 0 420 3700 Example 39 13 90 10 420 2760 Example 40 13 70 30 420 1360 Comp. Example 40 13 40 60 420 720 Comp. Example 41 17 100 0 380 4300 Example 41 17 90 10 380 3320 Example 42 17 70 30 380 1760 Comp. Example 42 17 40 60 380 850 Comp. Example 43 17 100 0 400 2480 Example 43 17 90 10 400 1760 Example 44 17 70 30 400 1030 Comp. Example 44 17 40 60 400 420 Note) L.C. type polyimide :Liquid crystal type polyimide Examples 45 ∼48 The polyimide powder obtained in Synthesis Examples 14 was dryblended with the liquid crystal type polyimide powder obtained in Synthesis Example 16 in various proportions illustrated in Table 10. Melt viscosity of the composition obtained was measured with a Koka type flow tester (Shimadzu CFT-500) under 100 Kg load by using an oriffice of 0.1 cm in diameter and 1 cm in length. Results are illustrated in Table 10. Comparative Examples 45 ∼ 48 Compositions outside the scope of the invention were prepared and melt viscosity of these compositions was measured by the same procedures as carried out in Examples 45∼ 48. Results are illustrated in Table 10. No. Polyimide L.C. type polyimide Synthesis Example 16 wt. part Flow tester Synthesis Example No. wt. part temperature (°C) Melt viscosity (poise) Comp. Example 45 14 100 0 400 5580 Example 45 14 90 10 400 4370 Example 46 14 70 30 400 2130 Comp. Example 46 14 40 60 400 920 Comp. Example 47 14 100 0 420 3730 Example 47 14 90 10 420 2790 Example 48 14 70 30 420 1380 Comp. Example 48 14 40 60 420 750 Note) L.C. type polyimide: Liquid crystal type polyimide Examples 49 ∼ 56 The polyimide powder obtained in Synthesis Examples 9, 10, 11, and 12 was dryblending with the liquid crystal type polyimide powder obtained in Synthesis Examples 7 and 8 in various proportions illustrated in Table 11. The compositions thus obtained was melt-kneaded and delivered from an extruder having a bore diameter of 40 mm and screw compression ratio of 3:1 and cut into uniform pallets. The pallets thus obtained were injection molded as usual and the minimum injection pressure was measured. Results are illustrated in Table 11. Comparative Examples 49 ∼ 56 Compositions outside the scope of the invention were prepared and melt viscosity of these compositions was measured by the same procedures as carried out in Examples 49∼ 56 Results are illustrated in Table 11. Polyimide L.C. type polyimide Synthesis Example No wt. part Synthesis Example No. wt. part Minimum injection pressure (kg/cm 2 ) Com.Ex. 49 9 100 7 0 650 Example 49 9 90 7 10 540 Example 50 9 70 7 30 210 Com.Ex. 50 9 40 7 60 Com.Ex. 51 10 100 7 0 680 Example 51 10 90 7 10 560 Example 52 10 70 7 30 280 Com.Ex. 52 10 40 7 60 Com.Ex. 53 11 100 7 0 550 Example 53 11 90 7 10 460 Example 54 11 70 7 30 220 Com.Ex. 54 11 40 7 60 Com.Ex. 55 12 100 8 0 660 Example 55 12 90 8 10 560 Example 56 12 70 8 30 220 Com.Ex. 56 12 40 8 60 Examples 57 ∼ 60 The polyimide powder obtained in Synthesis Example 18 was dryblended with the liquid crystal type polyimide powder obtained in Synthesis Example 1 in various proportions illustrated in Table 12. Melt viscosity of the composition obtained was measured with a Koka type flow tester (Shimadzu CFT-500) under 100 Kg load by using an oriffice of 0.1 cm in diameter and 1 cm in length. Results are illustrated in Table 12. Comparative Examples 57 ∼60 Compositions outside the scope of the invention were prepared and melt viscosity of these compositions was measured by the same procedures as carried out in Examples 57∼ 60. Results are illustrated in Table 12. No. Polyimide Synthesis Example 18 wt. part L.C.type polyimide Flow tester Synthesis Example No. wt.part temperature (°C) Melt viscosity (poise) Comp. Example 57 100 1 0 380 10200 Example 57 90 1 10 380 5900 Example 58 70 1 30 380 2500 Comp. Example 58 40 1 60 380 980 Comp. Example 59 100 1 0 400 6200 Example 59 90 1 10 400 3020 Example 60 70 1 30 400 1640 Comp. Example 60 40 1 60 400 800 Examples 61 ∼ 64 The polyimide powder obtained in Synthesis Example 19 was dryblended with the liquid crystal type polyimide powder obtained in Synthesis Example 7 in various proportions illustrated in Table 13. Melt viscosity of the composition obtained was measured with a Koka type flow tester (Shimadzu CFT-500) under 100 Kg load by using an oriffice of 0.1 cm in diameter and 1 cm in length. Results are illustrated in Table 13. Comparative Examples 61 ∼64 Compositions outside the scope of the invention were prepared and melt viscosity of these compositions was measured by the same procedures as carried out in Examples 61∼ 64. Results are illustrated in Table 13. No. Polyimide Synthesis Example 19 wt. part L.C.type polyimide Flow tester Synth. Example No. wt. part temperature (°C) Melt viscosity (poise) Comp. Example 61 100 7 0 380 9800 Example 61 90 7 10 380 5640 Example 62 70 7 30 380 2320 Comp. Example 62 40 7 60 380 950 Comp. Example 63 100 7 0 400 6120 Example 63 90 7 10 400 2980 Example 64 70 7 30 400 1600 Comp. Example 64 40 7 60 400 760 Examples 65 ∼ 68 The polyimide powder obtained in Synthesis Example 20 was dryblended with the liquid crystal type polyimide powder obtained in Synthesis Example 8 in various proportions illustrated in Table 14. Melt viscosity of the composition obtained was measured with a Koka type flow tester (Shimadzu CFT-500) under 100 Kg load by using an oriffice of 0.1 cm in diameter and 1 cm in length. Results are illustrated in Table 14. Comparative Examples 65 ∼ 68 Compositions outside the scope of the invention were prepared and melt viscosity of these compositions was measured by the same procedures as carried out in Examples 65∼ 68. Results are illustrated in Table 14. No. Polyimide Synthesis Example 20 wt. part L.C.type polyimide Flow tester Synth. Example No. wt.part temperature (°C) Melt viscosity (poise) Comp. Example 65 100 8 0 380 11300 Example 65 90 8 10 380 6100 Example 66 70 8 30 380 2750 Comp. Example 66 40 8 60 380 990 Comp. Example 67 100 8 0 400 6520 Example 67 90 8 10 400 3210 Example 68 70 8 30 400 1770 Comp. Example 68 40 8 60 400 890 Examples 69 ∼ 72 The polyimide powder obtained in Synthesis Example 21 was dryblended with the liquid crystal type polyimide powder obtained in Synthesis Example 15 in various proportions illustrated in Table 15. Melt viscosity of the composition obtained was measured with a Koka type flow tester (Shimadzu CFT-500) under 100 Kg load by using an oriffice of 0.1 cm in diameter and 1 cm in length. Results are illustrated in Table 15. Comparative Examples 69 ∼ 72 Compositions outside the scope of the invention were prepared and melt viscosity of these compositions was measured by the same procedures as carried out in Examples 69∼ 72. Results are illustrated in Table 15. No. Polyimide Synthesis Example 21 wt. part L.C.type polyimide Flow tester Synth. Example No. wt. part temperature (°C) Melt viscosity (poise) Comp. Example 69 100 15 0 380 10000 Example 69 90 15 10 380 5880 Example 70 70 15 30 380 2440 Comp. Example 70 40 15 60 380 960 Comp. Example 71 100 15 0 400 6180 Example 71 90 15 10 400 2950 Example 72 70 15 30 400 1630 Comp. Example 72 40 15 60 400 840 Examples 73 ∼ 76 The polyimide powder obtained in Synthesis Example 22 was dryblended with the liquid crystal type polyimide powder obtained in Synthesis Example 16 in various proportions illustrated in Table 16. Melt viscosity of the composition obtained was measured with a Koka type flow tester (Shimadzu CFT-500) under 100 Kg load by using an oriffice of 0.1 cm in diameter and 1 cm in length. Results are illustrated in Table 16. Comparative Examples 73 ∼ 76 Compositions outside the scope of the invention were prepared and melt viscosity of these compositions was measured by the same procedures as carried out in Examples 73∼ 76. Results are illustrated in Table 16. No. Polyimide Synthesis Example 22 L.C.type polyimide Flow tester wt. part Synth. Example No. wt. part temperature (°C) Melt viscosity (poise) Comp. Example 73 100 16 0 380 10840 Example 73 90 16 10 380 5880 Example 74 70 16 30 380 2480 Comp. Example 74 40 16 60 380 970 Comp. Example 75 100 16 0 400 6180 Example 75 90 16 10 400 3180 Example 76 70 16 30 400 1720 Comp. Example 76 40 16 60 400 830 Examples 77 ∼ 80 The polyimide powder obtained in Synthesis Example 19 and 21 were dryblended with the liquid crystal type polyimide powder obtained in Synthesis Example 7 and 15 in various proportions illustrated in Table 17 and 18. The compositions thus obtained was melt-kneaded and delivered from an extruder having a bore diameter of 40 mm and screw compression ratio of 3:1 and cut into uniform pallets. The pallets thus obtained were injection molded as usual and the minimum injection pressure was measured. Results are illustrated in Table 17 and 18. Comparative Examples 77 ∼ 80 Compositions outside the scope of the invention were prepared and melt viscosity of these compositions was measured by the same procedures as carried out in Examples 77∼80. Results are illustrated in Table 17 and 18. Polyimide L.C. type polyimide Minimum injection pressure * (kg/cm 2 ) Synthesis Example No wt. part Synthesis Example No. wt. part Com.Ex. 77 19 100 7 0 690 Example 77 19 90 7 10 520 Example 78 19 70 7 30 280 Com.Ex. 78 19 40 7 60 ** Polyimide L.C. type polyimide Minimum injection pressure (kg/cm 2 ) Synthesis Example No wt. parts Synthesis Example No. wt. parts Com.Ex. 79 21 100 15 0 650 Example 79 21 90 15 10 510 Example 80 21 70 15 30 260 Com.Ex. 80 21 40 15 60 Examples 81 ∼88 The polyimide powder obtained in Synthesis Examples 23 and 24 was dry blended with the liquid crystal type polyimide powder obtained in Synthesis Example 1 in various proportion illustrated in Tables 19 and 20. Melt viscosity of the mixture was measured with a Koka type flow tester CFT-500(Trade Mark of Shimadzu Seisakusho Co.) by using an oriffice of 0.1 cm in diameter and 1 cm in length under 100 kg load. Results are illustrated in Table 19 and 20. Glass transition temperature (Tg) of the strand extruded from the flow tester was measured by DSC and illustrated in Tables 19 and 20. Mixtures of aromatic polyimide copolymer with the liquid crystal type aromatic polyimide in the proportion of these examples had lower melt viscosity as compared with aromatic polyimide copolymer alone and were almost equal in Tg to that of aromatic polyimide copolymer. Comparative Examples 81 ∼88 Compositions outside the scope of the invention were used and melt viscosity was measured by the same procedures as carried out in Examples 81∼ 88. Results are illustrated in Tables 19 and 20. Polyimide Synthesis Example 23 (wt.part) Liquid Crystal Polyimide Flow tester Tg (°C) Synth. Example No. (wt.part) temperature (°C) Melt Viscosit (poise) Comparative Example 81 100 1 0 400 16000 254 Example 81 90 1 10 400 8300 250 Example 82 70 1 30 400 3200 250 Comparative Example 82 40 1 60 400 1200 244 Comparative Example 83 100 1 0 420 8900 253 Example 83 90 1 10 420 5680 250 Example 84 70 1 30 420 2250 251 Comparative Example 84 40 1 60 420 1050 244 Polyimide Synthesis Example 24 (wt.part) Liquid Crystal Polyimide Flow tester Tg (°C) Synth. Example No. (wt.part) temperature (°C) Melt Viscosit (poise) Comparative Example 85 100 1 0 400 14200 251 Example 85 90 1 10 400 6320 250 Example 86 70 1 30 400 2800 251 Comparative Example 86 40 1 60 400 980 245 Comparative Example 87 100 1 0 420 5600 251 Example 87 90 1 10 420 3900 250 Example 88 70 1 30 420 1960 251 Comparative Example 88 40 1 60 420 870 245 Examples 89 ∼96 The polyimide powder obtained in Synthesis Examples 25 and 29 was dry blended with the liquid crystal type polyimide powder obtained in Synthesis Example 7 in various proportion illustrated in Tables 21 and 22. Melt viscosity of the mixture was measured with a Koka type flow tester CFT-500(Trade Mark of Shimadzu Seisakusho Co.) by using an oriffice of 0.1 cm in diameter and 1 cm in length under 100 kg load. Results are illustrated in Table 21 and 22. Glass transition temperature (Tg) of the strand extruded from the flow tester was measured by DSC and illustrated in Tables 21 and 22. Mixtures of aromatic polyimide copolymer with the liquid crystal type aromatic polyimide in the proportion of these examples had lower melt viscosity as compared with aromatic polyimide copolymer alone and were almost equal in Tg to that of aromatic polyimide copolymer. Comparative Examples 89 ∼96 Compositions outside the scope of the invention were used and melt viscosity was measured by the same procedures as carried out in Examples 89∼96. Results are illustrated in Tables 21 and 22. Polyimide Synthesis Example 25 (wt.part) Liquid Crystal Polyimide Flow tester Tg (°C) Synth. Example No. (wt.part) temperature (°C) Melt Viscosit (poise) Comparative Example 89 100 7 0 400 15800 253 Example 89 90 7 10 400 8000 251 Example 90 70 7 30 400 3100 250 Comparative Example 90 40 7 60 400 1100 246 Comparative Example 91 100 7 0 420 8860 254 Example 91 90 7 10 420 5500 250 Example 92 70 7 30 420 2200 251 Comparative Example 92 40 7 60 420 980 246 Polyimide Synthesis Example 29 (wt.part) Liquid Crystal Polyimide Flow tester Tg (°C) Synth. Example No. (wt.part) temperature (°C) Melt Viscosit (poise) Comparative Example 93 100 7 0 400 14600 251 Example 93 90 7 10 400 6400 250 Example 94 70 7 30 400 2780 251 Comparative Example 94 40 7 60 400 990 245 Comparative Example 95 100 7 0 420 5700 251 Example 95 90 7 10 420 3860 249 Example 96 70 7 30 420 1900 250 Comparative Example 96 40 7 60 420 900 245 Examples 97∼100 The polyimide powder obtained in Synthesis Example 26 was dry blended with the liquid crystal type polyimide powder obtained in Synthesis Example 8 in various proportion illustrated in Table 23. Melt viscosity of the mixture was measured with a Koka type flow tester CFT-500 (Trade Mark of Shimadzu Seisakusho Co.) by using an oriffice of 0.1 cm in diameter and 1 cm in length under 100 kg load. Results are illustrated in Table 23. Glass transition temperature (Tg) of the strand extruded from the flow tester was measured by DSC and illustrated in Table 23. Mixtures of aromatic polyimide copolymer with the liquid crystal type aromatic polyimide in the proportion of these examples had lower melt viscosity as compared with aromatic polyimide copolymer alone and were almost equal in Tg to that of aromatic polyimide copolymer. Comparative Examples 97 ∼100 Compositions outside the scope of the invention were used and melt viscosity was measured by the same procedures as carried out in Examples 97∼100. Results are illustrated in Table 23. Polyimide Synthesis Example 26 (wt.part) Liquid Crystal Polyimide Flow tester Tg (°C) Synth. Example No. (wt.part) temperature (°C) Melt Viscosit (poise) Comparative Example 97 100 8 0 400 16100 255 Example 97 90 8 10 400 8400 253 Example 98 70 8 30 400 3280 252 Comparative Example 98 40 8 60 400 1300 248 Comparative Example 99 100 8 0 420 8960 253 Example 99 90 8 10 420 5700 252 Example 100 70 8 30 420 2400 253 Comparative Example 100 40 8 60 420 1000 249 Examples 101∼108 The polyimide powder obtained in Synthesis Examples 27 and 30 was dry blended with the liquid crystal type polyimide powder obtained in Synthesis Example 15 in various proportion illustrated in Tables 24 and 25. Melt viscosity of the mixture was measured with a Koka type flow tester CFT-500(Trade Mark of Shimadzu Seisakusho Co.) by using an oriffice of 0.1 cm in diameter and 1 cm in length under 100 kg load. Results are illustrated in Tables 24 and 25. Glass transition temperature (Tg) of the strand extruded from the flow tester was measured by DSC and illustrated in Tables 24 and 25. Mixtures of the aromatic polyimide copolymer with the liquid crystal type aromatic polyimide in the proportion of these examples had lower melt viscosity as compared with aromatic polyimide copolymer alone and were almost equal in Tg to that of aromatic polyimide copolymer. Comparative Examples 101∼108 Compositions outside the scope of the invention were used and melt viscosity was measured by the same procedures as carried out in Examples 101∼108. Results are illustrated in Tables 24 and 25. Polyimide Synthesis Example 27 (wt.part) Liquid Crystal Polyimide Flow tester Tg (°C) Synth. Example No. (wt.part) temperature (°C) Melt Viscosit (poise) Comparative Example 101 100 15 0 400 16500 253 Example 101 90 15 10 400 8600 252 Example 102 70 15 30 400 3350 253 Comparative Example 102 40 15 60 400 1240 246 Comparative Example 103 100 15 0 420 9000 252 Example 103 90 15 10 420 5860 253 Example 104 70 15 30 420 2400 250 Comparative Example 104 40 15 60 420 1080 249 Polyimide Synthesis Example 30 (wt.part) Liquid Crystal Polyimide Flow tester Tg (°C) Synth. Example No. (wt.part) temperature (°C) Melt Viscosit (poise) Comparative Example 105 100 15 0 400 14800 250 Example 105 90 15 10 400 6400 251 Example 106 70 15 30 400 2880 248 Comparative Example 106 40 15 60 400 990 247 Comparative Example 107 100 15 0 420 5720 251 Example 107 90 15 10 420 3960 250 Example 108 70 15 30 420 2000 250 Comparative Example 108 40 15 60 420 920 246 Examples 109∼112 Polyimide powder obtained in Synthesis Examples 28 was dry blended with liquid crystal type polyimide powder obtained in Synthesis Example 16 in various proportions illustrated in Tables 26. Melt viscosity of the mixture was measured with a Koka type flow tester CFT-500(Trade Mark of Shimadzu Seisakusho Co.) by using an oriffice of 0.1 cm in diameter and 1 cm in length under 100 kg load. Results are illustrated in Table 26. Glass transition temperature (Tg) of the strand extruded from the flow tester was measured by DSC and illustrated in Table 26. Mixtures of the aromatic polyimide copolymer with the liquid crystal type aromatic polyimide in the proportion of these examples had lower melt viscosity as compared with aromatic polyimide copolymer alone and were almost equal in Tg to that of aromatic polyimide copolymer. Comparative Examples 109∼112 Compositions outside the scope of the invention were used and melt viscosity was measured by the same procedures as carried out in Examples. 109∼112. Results are illustrated in Table 26. Polyimide Synthesis Example 28 (wt.part) Liquid Crystal Polyimide Flow tester Tg (°C) Synth. Example No. (wt.part) temperature (°C) Melt Viscosit (poise) Comparative Example 109 100 16 0 400 16000 252 Example 109 90 16 10 400 8200 252 Example 110 70 16 30 400 3180 252 Comparative Example 110 40 16 60 400 1180 246 Comparative Example 111 100 16 0 420 8860 253 Example 111 90 16 10 420 5480 251 Example 112 70 16 30 420 2400 250 Comparative Example 112 40 16 60 420 960 245 Examples 113∼120 Polyimide powder obtained in Synthesis Examples 25, 27, 29 and 30 was dry blended with liquid crystal type polyimide powder obtained in Synthesis Example 7 and 15 in various proportions illustrated in Tables 27 and 28. The mixture was melt-kneaded with an extruder having a bore diameter of 40 mm and screw compression ratio of 3:1, and extruded to obtain uniform pellets. The pellets thus obtained were injection molded with common injection molding machine and minimum injection pressure of the molded article was measured. Results are illustrated in Tables 27 and 28. Mixtures of the aromatic polyimide copolymer with the liquid crystal type aromatic polyimide in the proportion of these examples had lower minimum injection pressure as compared with the aromatic polyimide copolymer alone and were better in processability. Comparative Examples 113∼120 Compositions outside the scope of the invention were used and minimum injection pressure was measured by the same procedures as carried out in Examples 113 ∼120. Results are illustrated in Tables 27 and 28. Compositions which did not contain liquid crystal type aromatic polyimide at all had high minimum injection pressure. When the amount of the liquid crystal type aromatic polyimide exceeds 50 parts by weight of the aromatic polyimide copolymer, melt viscosity became too low and minimum injection pressure could not be measured. Polyimide L.C. type polyimide Minimum injection pressure (kg/cm 2 ) Synthesis Example wt. parts Synthesis Example No. wt. parts Com.Ex. 113 25 100 7 0 680 Example 113 25 90 7 10 560 Example 114 25 70 7 30 320 Com.Ex. 114 25 40 7 60 Com.Ex. 115 29 100 7 0 670 Example 115 29 90 7 10 540 Example 116 29 70 7 30 290 Com.Ex. 116 29 40 7 60 Polyimide L.C. type polyimide Minimum injection pressure (kg/cm 2 ) Synthesis Example wt. parts Synthesis Example No. wt. parts Com.Ex. 117 27 100 15 0 650 Example 117 27 90 15 10 520 Example 118 27 70 15 30 280 Com.Ex. 118 27 40 15 60 Com.Ex. 119 30 100 15 0 670 Example 119 30 90 15 10 560 Example 120 30 70 15 30 270 Com.Ex. 120 30 40 15 60 Examples 121 and 122 The pellets which were obtained in Examples 113 and 115 by blending the aromatic polyimide copolymer with the liquid crystal type aromatic polyimide in a ratio of 90 : 10 were injection molded at an injection temperature of 360 ∼400 °C and mold temperature of 150°C. Mechanical properties of molded specimens were measured and results are illustrated in Table 29. Tensile strength, tensile elastic modulus and elongation were measured in accordance with ASTM D-638. The mixture of the aromatic polyimide copolymer and liquid liquid crystal type aromatic polyimide in a proportion of these examples had mechanical properties equivalent to the aromatic polyimide copolymer alone in Comparative Examples 121 and 122. Thus, mechanical properties were not decreased even though the liquid crystal type aromatic polyimide was mixed in the range of the invention. Comparative Examples 121 and 122 Pellets obtained in Comparative Examples 113 and 115 were injection molded by the same procedures as carried out in Examples 121 and 122. Mechanical properties of molded specimens were measured and results are illustrated in Table 29. Pellets used for molding Tensile strength (kg/cm 2 ) Tensile elastic modulas (kg/cm 2 ) Elongation (%) Comparative example 121 Comparative example 113 910 290 66 Example 121 Example 113 900 290 64 Comparative example 122 Comparative example 115 930 270 77 Example 122 Example 115 930 280 78 Examples 123∼126 Aromatic polysulfone resin powder, VICTOREX PES 4100P (Trade Mark of ICI Ltd.) was dryblended with the liquid crystal type polyimide powder obtained in Synthesis Example 1 in various proportions illustrated in Table 30. Melt viscosity of the composition obtained was measured with a Koka type flow tester (Shimadzu CFT-500) under 100 Kg load by using an oriffice of 0.1 cm in diameter and 1 cm in length. Results are illustrated in Table 30. Comparative Examples 123∼126 Compositions outside the scope of the invention were prepared and melt viscosity of these compositions was measured by the same procedures as carried out in Examples 123 ∼126. Results are illustrated in Table 30. No. VICTREX PES 4100P wt. part L.C.type polyimide Flow tester Synth. Example No. wt. part temperature (°C) Melt viscosity (poise) Comp. Example 123 100 1 0 370 5700 Example 123 90 1 10 370 3540 Example 124 70 1 30 370 1720 Comp. Example 124 40 1 60 370 900 Comp. Example 125 100 1 0 390 3300 Example 125 90 1 10 390 2000 Example 126 70 1 30 390 1050 Comp. Example 126 40 1 60 390 540 Examples 127∼130 Aromatic polysulfone resin powder, VICTOREX PES 4100P (Trade Mark of ICI Ltd.) was dryblended with the liquid crystal type polyimide powder obtained in Synthesis Example 7 in various proportions illustrated in Table 31. Melt viscosity of the composition obtained was measured with a Koka type flow tester (Shimadzu CFT-500) under 100 Kg load by using an oriffice of 0.1 cm in diameter and 1 cm in length. Results are illustrated in Table 31. Comparative Examples 123, 125, 127, 128 Compositions outside the scope of the invention were prepared and melt viscosity of these compositions was measured by the same procedures as carried out in Examples 127 ∼130. Results are illustrated in Table 31. No. VICTREX PES 4100P wt. part L.C.type polyimide Flow tester Synth. Example No. wt. part temperature (°C) Melt viscosity (poise) Comp. Example 123 100 7 0 370 5700 Example 127 90 7 10 370 3580 Example 128 70 7 30 370 1800 Comp. Example 127 40 7 60 370 920 Comp. Example 125 100 7 0 390 3300 Example 129 90 7 10 390 2040 Example 130 70 7 30 390 1080 Comp. Example 128 40 7 60 390 580 Examples 131∼134 Aromatic polysulfone resin powder, VICTOREX PES 4100P (Trade Mark of ICI Ltd.) was dryblended with the liquid crystal type polyimide powder obtained in Synthesis Example 15 in various proportions illustrated in Table 32. Melt viscosity of the composition obtained was measured with a Koka type flow tester (Shimadzu CFT-500) under 100 Kg load by using an oriffice of 0.1 cm in diameter and 1 cm in length. Results are illustrated in Table 32. Comparative Examples 123, 125, 129 and 130 Compositions outside the scope of the invention were prepared and melt viscosity of these compositions was measured by the same procedures as carried out in Examples 131 ∼134. Results are illustrated in Table 32. No. VICTREX PES 4100P wt. part L.C.type polyimide Flow tester Synth. Example No. wt. part temperature (°C) Melt viscosity (poise) Comp. Example 123 100 15 0 370 5700 Example 131 90 15 10 370 3350 Example 132 70 15 30 370 1550 Comp. Example 129 40 15 60 370 820 Comp. Example 125 100 15 0 390 3300 Example 133 90 15 10 390 1800 Example 134 70 15 30 390 1010 Comp. Example 130 40 15 60 390 480 Examples 135∼138 Aromatic polysulfone resin powder, UDEL POLYSULFONE P-1700 (Trade Mark of Union Carbide Corp.) was dryblended with the liquid crystal type polyimide powder obtained in Synthesis Example 7 in various proportions illustrated in Table 33. Melt viscosity of the composition obtained was measured with a Koka type flow tester (Shimadzu CFT-500) under 100 Kg load by using an oriffice of 0.1 cm in diameter and 1 cm in length. Results are illustrated in Table 33. Comparative Examples 131∼134 Compositions outside the scope of the invention were prepared and melt viscosity of these compositions was measured by the same procedures as carried out in Examples 135 ∼138. Results are illustrated in Table 33. No. UDEL POLYSULFONE P-1700 wt.part L.C.type polyimide Flow tester Synth. Example No. wt. part temperature (°C) Melt viscosity (poise) Comp. Example 131 100 7 0 370 4900 Example 135 90 7 10 370 3020 Example 136 70 7 30 370 1580 Comp. Example 132 40 7 60 370 650 Comp. Example 133 100 7 0 390 3020 Example 137 90 7 10 390 1860 Example 138 70 7 30 390 1040 Comp. Example 134 40 7 60 390 420 Examples 139∼142 Aromatic polysulfone resin powder, UDEL POLYSULFONE P-1700 (Trade Mark of Union Carbide Corp.) was dryblended with the liquid crystal type polyimide powder obtained in Synthesis Example 8 in various proportions illustrated in Table 34. Melt viscosity of the composition obtained was measured with a Koka type flow tester (Shimadzu CFT-500) under 100 Kg load by using an oriffice of 0.1 cm in diameter and 1 cm in length. Results are illustrated in Table 34. Comparative Examples 131, 133, 135 and 136 Compositions outside the scope of the invention were prepared and melt viscosity of these compositions was measured by the same procedures as carried out in Examples 139 ∼142. Results are illustrated in Table 34. No. UDEL POLYSULFONE P-1700 wt.part L.C.type polyimide Flow tester Synth. Example No. wt.part temperature (°C) Melt viscosity (poise) Comp. Example 131 100 8 0 370 4900 Example 139 90 8 10 370 3140 Example 140 70 8 30 370 1640 Comp. Example 135 40 8 60 370 700 Comp. Example 133 100 8 0 390 3020 Example 141 90 8 10 390 1890 Example 142 70 8 30 390 1050 Comp. Example 136 40 8 60 390 480 Examples 143∼146 Aromatic polysulfone resin powder, UDEL POLYSULFONE P-1700 (Trade Mark of Union Carbide Corp.) was dryblended with the liquid crystal type polyimide powder obtained in Synthesis Example 15 in various proportions illustrated in Table 35. Melt viscosity of the composition obtained was measured with a Koka type flow tester (Shimadzu CFT-500) under 100 Kg load by using an oriffice of 0.1 cm in diameter and 1 cm in length. Results are illustrated in Table 35. Comparative Examples 131, 133, 137 and 138 Compositions outside the scope of the invention were prepared and melt viscosity of these compositions was measured by the same procedures as carried out in Examples 143 ∼146. Results are illustrated in Table 35. No. UDEL POLYSULFONE P-1700 wt. part L.C.type polyimide Flow tester Synth. Example No. wt. part temperature (°C) Melt viscosity (poise) Comp. Example 131 100 15 0 370 4900 Example 143 90 15 10 370 3000 Example 144 70 15 30 370 1520 Comp. Example 137 40 15 60 370 600 Comp. Example 133 100 15 0 390 3020 Example 145 90 15 10 390 1840 Example 146 70 15 30 390 1000 Comp. Example 138 40 15 60 390 400 Examples 147∼150 Aromatic polysulfone resin powder, RADEL POLYSULFONE A-400 (Trade Mark of Union Carbide Corp.) was dryblended with the liquid crystal type polyimide powder obtained in Synthesis Example 7 in various proportions illustrated in Table 36. Melt viscosity of the composition obtained was measured with a Koka type flow tester (Shimadzu CFT-500) under 100 Kg load by using an oriffice of 0.1 cm in diameter and 1 cm in length. Results are illustrated in Table 36. Comparative Examples 139∼142 Compositions outside the scope of the invention were prepared and melt viscosity of these compositions was measured by the same procedures as carried out in Examples 147 ∼150. Results are illustrated in Table 36. No. RADEL POLYSULFONE A-400 wt. part L.C.type polyimide Flow tester Synth. Example No. wt. part temperature (°C) Melt viscosity (poise) Comp. Example 139 100 7 0 370 5200 Example 147 90 7 10 370 3020 Example 148 70 7 30 370 1500 Comp. Example 140 40 7 60 370 720 Comp. Example 141 100 7 0 390 3120 Example 149 90 7 10 390 1800 Example 150 70 7 30 390 1020 Comp. Example 142 40 7 60 390 500 Examples 151∼154 Aromatic polysulfone resin powder, RADEL POLYSULFONE A-400 (Trade Mark of Union Carbide Corp.) was dryblended with the liquid crystal type polyimide powder obtained in Synthesis Example 15 in various proportions illustrated in Table 37. Melt viscosity of the composition obtained was measured with a Koka type flow tester (Shimadzu CFT-500) under 100 Kg load by using an oriffice of 0.1 cm in diameter and 1 cm in length. Results are illustrated in Table 37. Comparative Examples 139, 141, 143 and 144 Compositions outside the scope of the invention were prepared and melt viscosity of these compositions was measured by the same procedures as carried out in Examples 151 ∼154. Results are illustrated in Table 37. No. RADEL POLYSULFONE A-400 wt. part L.C.type polyimide Flow tester Synth. Example No. wt. part temperature (°C) Melt viscosity (poise) Comp. Example 139 100 15 0 370 5200 Example 151 90 15 10 370 3000 Example 152 70 15 30 370 1480 Comp. Example 143 40 15 60 370 700 Comp. Example 141 100 15 0 390 3120 Example 153 90 15 10 390 1770 Example 155 70 15 30 390 1030 Comp. Example 144 40 15 60 390 480 Examples 155∼159 Aromatic polysulfone resin powder, UDEL POLYSULFONE A-400 (Trade Mark of Union Carbide Corp.) was dryblended with the liquid crystal type polyimide powder obtained in Synthesis Example 16 in various proportions illustrated in Table 38. Melt viscosity of the composition obtained was measured with a Koka type flow tester (Shimadzu CFT-500) under 100 Kg load by using an oriffice of 0.1 cm in diameter and 1 cm in length. Results are illustrated in Table 38. Comparative Examples 139, 141, 145 and 146 Compositions outside the scope of the invention were prepared and melt viscosity of these compositions was measured by the same procedures as carried out in Examples 155 ∼159. Results are illustrated in Table 38. No. RADEL POLYSULFONE A-400 wt. part L.C.type polyimide Flow tester Syn. Example No. wt. part temperature (°C) Melt viscosity (poise) Comp. Example 139 100 16 0 370 5200 Example 155 90 16 10 370 3080 Example 156 70 16 30 370 1520 Comp. Example 145 40 16 60 370 780 Comp. Example 141 100 16 0 390 3120 Example 157 90 16 10 390 1790 Example 158 70 16 30 390 1050 Comp. Example 146 40 16 60 390 520 Examples 159∼164 Aromatic polysulfone resin powder, VICTREX PES 4100P (Trade Mark of ICI Ltd.), UDEL POLYSULFONE P-1700 (Trade Mark of Union Carbide Corp.) and UDEL POLYSULFONE A-400 (Trade Mark of Union Carbide Corp.) were dryblended with the crystalline polyimide powder obtained in Synthesis Example 7 and 15 in various proportions illustrated in Table 39, 40 and 41. The compositions thus obtained was melt-kneaded and delivered from an extruder having a bore diameter of 40 mm and screw compression ratio of 3:1 and cut into uniform pellets. The pellets thus obtained were injection molded as usual and the minimum injection pressure was measured. Results are illustrated in Tables 39, 40 and 41. Comparative Examples 147∼152 Compositions outside the scope of the invention were prepared and minimum injection pressure of these compositions was measured by the same procedures as carried out in Example 159∼164. Results are illustrated in Table 39, 40 and 41. VICTREX PE S 4100P wt. parts L.C. type polyimide Minimum injection pressure (kg/cm 2 ) * Synthesis Example No. wt. parts Com.Ex. 147 100 7 0 680 Example 159 90 7 10 540 Example 160 70 7 30 270 Com.Ex. 148 40 7 60 ** UDEL POLYSULFONE P-1700 wt. parts L.C. type polyimide Minimum injection pressure (kg/cm 2 ) * Synthesis Example No. wt. parts Com.Ex. 149 100 7 0 560 Example 161 90 7 10 420 Example 162 70 7 30 200 Com.Ex. 150 40 7 60 ** RADEL POLYSULFONE A-400 wt. parts L.C. type polyimide Minimum injection pressure (kg/cm 2 ) Synthesis Example No. wt. parts Com.Ex. 151 100 7 0 660 Example 163 90 7 10 520 Example 164 70 7 30 240 Com.Ex. 152 40 7 60 Examples 165∼184 Aromatic polyether imide ULTEM 1000 (Trade Mark of G E Co.) was dryblended with the liquid crystal type polyimide powder obtained in Synthesis Examples 1, 7, 8, 15 and 16 in various proportions illustrated in Table 42 ∼46. Melt viscosity of the compositions obtained was measured with a Koka type flew tester (Shimadzu CFT-500) under 100 Kg load by using as oriffice of 0.1 cm in diameter and 1 cm in length. Results are illustrated in Tables 42∼46. Glass transition temperature (Tg) of the strand extruded from the oriffice was measured by DSC. Results are illustrated in Table 42 ∼ 46. The mixture of aromatic polyether imide and liquid crystal type aromatic polyimide in a proportion of the present example had lower melt viscosity than the aromatic polyether imide alone and was almost equal in Tg to the aromatic polyether imide, The strand obtained from the flow tester was tough as the strand of aromatic polyether imide alone. Comparative Example 153 ∼172 Compositions outside the scope of the invention were prepared and melt viscosity of these composition was measured by the same procedures as carried out in Example 165 ∼184. Results are illustrated in Table 42∼46. Aromatic polyether imide which does not contain the liquid crystal type aromatic polyimide at all had high melt viscosity. When the proportion of the liquid crystal type aromatic polyimide was 50 parts by weight or more for 50 parts by weight of aromatic polyether imide, melt viscosity was lowered and the strand obtained become brittle. Ultem 1000 wt. part Liquid Crystal Polyimide Flow tester Tg (°C) Synth. Example No. (wt.part) temperature (°C) Melt Viscosit (poise) Comparative Example 153 100 1 0 390 5900 216 Example 165 90 1 10 390 4260 215 Example 166 70 1 30 390 2200 215 Comparative Example 154 40 1 60 390 960 214 Comparative Example 155 100 1 0 400 4700 215 Example 167 90 1 10 400 3520 215 Example 168 70 1 30 400 1660 216 Comparative Example 156 40 1 60 420 780 214 Ultem 1000 wt.part Liquid Crystal Polyimide Flow tester Tg (°C) Synth. Example No. (wt.part) temperature (°C) Melt Viscosit (poise) Comparative Example 157 100 7 0 390 5880 216 Example 169 90 7 10 390 4200 214 Example 170 70 7 30 390 2160 215 Comparative Example 158 40 7 60 390 950 214 Comparative Example 159 100 7 0 400 4680 215 Example 171 90 7 10 400 3480 216 Example 172 70 7 30 400 1600 214 Comparative Example 160 40 7 60 420 740 215 Ultem 1000 wt.part Liquid Crystal Polyimide Flow tester Tg (°C) Synth. Example No. (wt.part) temperature (°C) Melt Viscosit (poise) Comparative Example 161 100 8 0 390 6080 215 Example 173 90 8 10 390 4440 214 Example 174 70 8 30 390 2320 216 Comparative Example 162 40 8 60 390 980 215 Comparative Example 163 100 8 0 400 4820 214 Example 175 90 8 10 400 3640 218 Example 176 70 8 30 400 1780 215 Comparative Example 164 40 8 60 400 820 216 Ultem 1000 wt.part Liquid Crystal Polyimide Flow tester Tg (°C) Synth. Example No. (wt.part) temperature (°C) Melt Viscosit (poise) Comparative Example 165 100 15 0 390 5600 215 Example 177 90 15 10 390 4060 217 Example 178 70 15 30 390 2020 214 Comparative Example 166 40 15 60 390 930 216 Comparative Example 167 100 15 0 400 4400 216 Example 179 90 15 10 400 3100 214 Example 180 70 15 30 400 1480 215 Comparative Example 168 40 15 60 420 720 216 Ultem 1000 wt.part Liquid Crystal Polyimide Flow tester Tg (°C) Synth. Example No. (wt.part) temperature (°C) Melt Viscosit (poise) Comparative Example 169 100 16 0 390 5920 217 Example 181 90 16 10 390 4280 215 Example 182 70 16 30 390 2260 216 Comparative Example 170 40 16 60 390 980 214 Comparative Example 171 100 16 0 400 4780 215 Example 183 90 16 10 400 3600 217 Example 184 70 16 30 400 1720 216 Comparative Example 172 40 16 60 420 780 214 Examples 185 ∼188 Aromatic polyether imide ULTEM 1000 (Trade Mark of G E Co.) was dryblended with the liquid crystal type polyimide powder obtained in Synthesis Examples 7 and 15 in various proportions illustrated in Table 47. The compositions thus obtained was melt-kneaded and delivered from an extruder having a bore diameter of 40 mm and screw compression ratio of 3:1 and cut into uniform pallets. The pellets thus obtained were injection molded as usual and the minimum injection pressure was measured. Results are illustrated in Table 47. The mixture of aromatic polyether imide and the liquid crystal type aromatic polyimide in a proportion of the examples had lower minimum injection pressure than better processability. Comparative Example 173 ∼176 Compositions outside the scope of the invention were prepared and the minimum injection pressure was measured by the same procedures as carried out in Example 185∼188. Results are illustrated in Table 47. Aromatic polyether imide which does not contain the liquid crystal type aromatic polyimide at all had high minimum injection pressure. When the liquid crystal type aromatic polyimide was 50 parts by weight or more for 50 parts by weight of the aromatic polyether imide, melt viscosity became too low and injection molding was difficult. Thus, minimum injection pressure could not be measured. UItem 1000 wt. part L.C. type polyimide Minimum injection pressure (kg/cm 2 ) Synthesis Example No. wt. part Com.Ex. 173 100 7 0 580 Example 185 90 7 10 440 Example 186 70 7 30 250 Com.Ex. 174 40 7 60 Com.Ex. 175 100 15 0 560 Example 187 90 15 10 420 Example 188 70 15 30 240 Com.Ex. 176 40 15 60 Example 189 ∼208 Aromatic polyamideimide TORLON 4203 L (Trade Mark of Amoco Co.) was dry blended with the polyimide powder obtained in Synthesis Examples 1, 7, 8, 15 and 16 in various proportions illustrated in Table 48∼52. The mixture was melt-kneaded with an extruder having a bore diameter of 40 mm and screw compression ratio of 3 : 1, and extruded to obtained uniform pellets. The pellets thus obtained were injection molded with a common injection molding machine and minimum injection pressure of the molded article was measured. Results are illustrated in Table 48 ∼52. The mixture of aromatic polyetheramideimide and liquid crystal type aromatic polyimide in a proportion of the present example had lower melt viscosity than the aromatic polyetheramideimide alone and was almost equal in Tg to the aromatic polyetheramideimide. Comparative Examples 177∼196 Compositions outside the scope of the invention were used and minimum injection pressure was measured by the same procedures as carried out in Examples 189 ∼208. Results are illustrated in Table 48 ∼52. TORLON 4203L wt.part Liquid Crystal Polyimide Flow tester Tg (°C) Synth. Example No. (wt.part) temperature (°C) Melt Viscosit (poise) Comparative Example 177 100 1 0 380 72500 275 Example 189 90 1 10 380 45000 274 Example 190 70 1 30 380 26400 275 Comparative Example 178 40 1 60 380 10700 273 Comparative Example 179 100 1 0 400 25100 274 Example 191 90 1 10 400 15500 272 Example 192 70 1 30 400 9100 275 Comparative Example 180 40 1 60 400 3700 273 TORLON 4203L wt.part Liquid Crystal Polyimide Flow tester Tg (°C) Synth. Example No. (wt.part) temperature (°C) Melt Viscosit (poise) Comparative Example 181 100 7 0 380 72200 276 Example 193 90 7 10 380 45500 273 Example 194 70 7 30 380 26800 275 Comparative Example 182 40 7 60 380 11000 274 Comparative Example 183 100 7 0 400 26800 274 Example 195 90 7 10 400 16500 275 Example 196 70 7 30 400 9700 276 Comparative Example 184 40 7 60 400 3900 274 TORLON 4203L wt.part Liquid Crystal Polyimide Flow tester Tg (°C) Synth. Example No. (wt.part) temperature (°C) Melt Viscosit (poise) Comparative Example 185 100 8 0 380 72500 274 Example 197 90 8 10 380 46300 275 Example 198 70 8 30 380 27200 272 Comparative Example 186 40 8 60 380 11000 274 Comparative Example 187 100 8 0 400 26800 275 Example 199 90 8 10 400 16600 276 Example 200 70 8 30 400 9800 273 Comparative Example 188 40 8 60 400 4000 275 TORLON 4203L wt.part Liquid Crystal Polyimide Flow tester Tg (°C) Synth. Example No. (wt.part) temperature (°C) Melt Viscosit (poise) Comparative Example 189 100 15 0 380 73000 274 Example 201 90 15 10 380 43800 276 Example 202 70 15 30 380 25700 274 Comparative Example 190 40 15 60 380 10500 274 Comparative Example 191 100 15 0 400 25300 275 Example 203 90 15 10 400 14800 273 Example 204 70 15 30 400 8700 275 Comparative Example 192 40 15 60 400 3500 2773 TORLON 4203L wt.part Liquid Crystal Polyimide Flow tester Tg (°C) Synth. Example No. (wt.part) temperature (°C) Melt Viscosit (poise) Comparative Example 193 100 16 0 380 72800 274 Example 205 90 16 10 380 45000 275 Example 206 70 16 30 380 26400 275 Comparative Example 194 40 16 60 380 10800 274 Comparative Example 195 100 16 0 400 25800 276 Example 207 90 16 10 400 15900 275 Example 208 70 16 30 400 9300 273 Comparative Example 196 40 16 60 400 3800 274 Examples 209∼212 Aromatic polyamideimide TORLON 4203 L (Trade Mark of Amoco Co.) was dry blended with the polyimide powder obtained in Synthesis Examples 7 and 15 in various proportions illustrated in Table 53. The mixture was melt-kneaded with an extruder having a bore diameter of 40 mm and screw compression ratio of 3 : 1, and extruded to obtained uniform pellets. The pellets thus obtained were injection molded with a common injection molding machine and minimum injection pressure of the molded article was measured. Results are illustrated in Table 53. Mixtures of the aromatic polyamideimide with the liquid crystal type aromatic polyimide in the proportion of these examples had lower minimum injection pressure as compared with the aromatic polyamideimide alone and were better in processability. Comparative Examples 197∼200 Compositions outside the scope of the invention were used and minimum injection pressure was measured by the same procedures as carried out in Examples 209 ∼212. Results are illustrated in Table 53. Composition which did not contain liquid crystal type aromatic polyimide at all had high minimum injection pressure. When the aromatic of the liquid crystal type aromatic polyimide exceeds 50 parts by weight for 50 parts by weight of the aromatic polyamideimide melt viscosity became too low and minimum injection pressure could not be measured. TORLON 4203L wt. part L.C. type polyimide Minimum injection pressure (kg/cm 2 ) Synthesis Example No. wt. part Com.Ex. 197 100 7 0 610 Example 209 90 7 10 470 Example 210 70 7 30 280 Com.Ex. 198 40 7 60 Com.Ex. 199 100 15 0 610 Example 211 90 15 10 460 Example 212 70 15 30 270 Com.Ex. 200 40 15 60 Example 213 The pellets which were obtained in Example 209 by blending the aromatic polyamideimide with the liquid crystal type aromatic polyimide in a ratio of 90 : 10 were injection molded at an injection temperature of 360 ∼400 °C and mold temperature of 160°C. Mechanical properties of molded specimens were measured and results are illustrated in Table 54. Tensile strength, tensile elastic modulus and elongation were measured in accordance with ASTM D-638. The mixture of the aromatic polyamideimide and the liquid crystal type aromatic polyimide in a proportion of these examples had mechanical properties equivalent to the aromatic polyamideimide alone in Comparative Example 201. Thus, mechanical properties were not decreased even though the liquid crystal type aromatic polyimide was mixed in the range of the invention. Comparative Example 201 Pellets obtained in Comparative Example 197 were injection mold by the procedures is carried out in Example 213 and mechanical properties of molded specimens were measured. Results are illustrated in Table 54. Pellets used for molding Tensile strength (Kg/cm 2 ) Tensile slastic modulus (Kg/cm 2 ) Elongation (%) Comparative Example 201 Comparative Example 197 1910 450 12 Example 213 Example 209 1920 450 11 Examples 214∼233 Aromatic polyether ketone VICTREX PEEK 450 P (Trade Mark of ICI Ltd.) was dry blended with the liquid crystal type polyimide powder obtained in Synthesis Examples 1, 7, 8, 15 and 16 in various proportions illustrated in Table 55∼59. Melt viscosity of the mixture was measured with a Koka type flow tester CFT-500 (Trade Mark of Shimazu Seisakusho Co.) by using an oriffice of 0.1 cm in diameter and 1 cm in length under 100 Kg load. Results are illustrated in Table 55 ∼59. Glass transition temperature (Tg) of the strand extruded from the tester was measured by DSC and illustrated in table 55∼59. Mixtures of the aromatic polyether ketone with the liquid crystal type aromatic polyimide in the proportion of these examples had lower melt viscosity as compared with aromatic polyether ketone alone and were almost equal in Tg that of aromatic polyether ketone. Comparative Example 202 ∼221 Comparative outside the scope of the invention were used and melt viscosity was measured by the same procedures as carried out in Examples 214∼233. Results are illustrated in Table 55∼59. VICTREX PEEK 450P wt.part Liquid Crystal Polyimide Flow tester Tg (°C) Synth. Example No. (wt.part) temperature (°C) Melt Viscosit (poise) Comparative Example 202 100 1 0 380 10500 143 Example 214 90 1 10 380 6700 145 Example 215 70 1 30 380 4000 144 Comparative Example 203 40 1 60 380 1560 145 Comparative Example 204 100 1 0 400 6100 144 Example 216 90 1 10 400 5180 144 Example 217 70 1 30 400 3200 145 Comparative Example 205 40 1 60 400 1010 143 VICTREX PEEK 450P wt.part Liquid Crystal Polyimide Flow tester Tg (°C) Synth. Example No. (wt.part) temperature (°C) Melt Viscosit (poise) Comparative Example 206 100 7 0 380 11000 144 Example 218 90 7 10 380 6780 146 Example 219 70 7 30 380 3980 145 Comparative Example 207 40 7 60 380 1620 146 Comparative Example 208 100 7 0 400 6220 146 Example 220 90 7 10 400 5200 147 Example 221 70 7 30 400 3180 144 Comparative Example 209 40 7 60 400 1200 146 VICTREX PEEK 450P wt.part Liquid Crytal Polyimide Flow tester Tg (°C) Synth. Example No. (wt.part) temperature (°C) Melt Viscosit (poise) Comparative Example 210 100 8 0 380 11800 145 Example 222 90 8 10 380 6820 146 Example 223 70 8 30 380 4120 145 Comparative Example 211 40 8 60 380 1760 147 Comparative Example 212 100 8 0 400 6320 145 Example 224 90 8 10 400 5220 147 Example 225 70 8 30 400 3430 146 Comparative Example 213 40 8 60 400 1210 146 VICTREX PEEK 450P wt.part Liquid Crystal Polyimide Flow tester Tg (°C) Synth. Example No. (wt.part) temperature (°C) Melt Viscosit (poise) Comparative Example 214 100 15 0 380 9860 145 Example 226 90 15 10 380 6240 147 Example 227 70 15 30 380 3680 145 Comparative Example 215 40 15 60 380 1460 146 Comparative Example 216 100 15 0 400 6020 144 Example 228 90 15 10 400 5000 145 Example 229 70 15 30 400 3040 145 Comparative Example 217 40 15 60 400 1000 145 VICTREX PEEK 450P wt.part Liquid Crystal Polyimide Flow tester Tg (°C) Synth. Example No. (wt.part) temperature (°C) Melt Viscosit (poise) Comparative Example 218 100 16 0 380 10200 143 Example 230 90 16 10 380 6500 145 Example 231 70 16 30 380 3880 144 Comparative Example 219 40 16 60 380 1600 145 Comparative Example 220 100 16 0 400 6000 146 Example 232 90 16 10 400 5080 145 Example 233 70 16 30 400 3160 146 Comparative Example 221 40 16 60 400 1000 147 VICTREX PEK 220G wt.part Liquid Crystal Polyimide Flow tester Tg (°C) Synth. Example No. (wt.part) temperature (°C) Melt Viscosit (poise) Comparative Example 222 100 1 0 380 7800 162 Example 234 90 1 10 380 5200 164 Example 235 70 1 30 380 3200 165 Comparative Example 223 40 1 60 380 1240 163 Comparative Example 224 100 1 0 400 4600 163 Example 236 90 1 10 400 3480 164 Example 237 70 1 30 400 2020 163 Comparative Example 225 40 1 60 400 860 165 VICTREX PEK 220G wt.part Liquid Crystal Polyimide Flow tester Tg (°C) Synth. Example No. (wt.part) temperature (°C) Melt Viscosit (poise) Comparative Example 226 100 7 0 380 7680 163 Example 238 90 7 10 380 5100 164 Example 239 70 7 30 380 3120 164 Comparative Example 227 40 7 60 380 1200 165 Comparative Example 228 100 7 0 400 4480 163 Example 240 90 7 10 400 3360 165 Example 241 70 7 30 400 1960 164 Comparative Example 229 40 7 60 400 840 165 VICTREX PEK 220G wt.part Liquid Crystal Polyimide Flow tester Tg (°C) Synth. Example No. (wt.part) temperature (°C) Melt Viscosit (poise) Comparative Example 230 100 15 0 380 8020 164 Example 242 90 15 10 380 5420 165 Example 243 70 15 30 380 3340 164 Comparative Example 231 40 15 60 380 1320 166 Comparative Example 232 100 15 0 400 4750 164 Example 244 90 15 10 400 3600 166 Example 245 70 15 30 400 2140 165 Comparative Example 233 40 15 60 400 980 165 Examples 246∼253 Aromatic polyether ketone VICTREX PEEK 450 P and VICTREX PEX 220 G (Trade Mark of ICI Ltd.) was dryblended with the liquid crystal type polyimide powder obtained in Synthesis Examples 7 and 15 in various proportions illustrated in Table 63 and 64. The composition thus obtained was melt-Kneaded and delivered from an extruder having a bore of 40 mm and screw compression ration of 3 : 1 and cut into uniform pellets. The pellets thus obtained were injection molded as usual and the minimum injection pressure was measured. Results are illustrated in Tables 63 and 64. The mixture of aromatic polyether ketone and the liquid crystal type aromatic polyimide in proportions of the examples had lower minimum injection pressure than aromatic polyether'ketone alone and was proved to have better processability. Comparative Examples 234∼241 Composition outside the scope of the invention were prepared and the minimum injection pressure was measured by the same procedures as carried out Examples 246 ∼253. Results are illustrated in Tables 63 and 64. Aromatic polyether imide which does not contain the liquid crystal type aromatic polyimide at all had high minimum injection pressure. When the liquid crystal type aromatic polyimide was 50 parts by weight or more for 50 parts by weight of the aromatic polyether imide, melt viscosity become too low and injection molding was different. Thus, minimum injection pressure could not be measured. VICTREX PEX 220G wt. part L.C. type polyimide Minimum injection pressure (kg/cm 2 ) Synthesis Example No. wt. part Com.Ex. 234 100 7 0 620 Example 246 90 7 10 480 Example 247 70 7 30 290 Com.Ex. 235 40 7 60 Com.Ex. 236 100 15 0 660 Example 248 90 15 10 470 Example 249 70 15 30 260 Com.Ex. 237 40 15 60 VICTREX PEX 220G wt. part L.C. type polyimide Minimum injection pressure (kg/cm 2 ) Synthesis Example No. wt. part Com.Ex. 238 100 7 0 570 Example 250 90 7 10 430 Example 251 70 7 30 220 Com.Ex. 239 40 7 60 Com.Ex. 240 100 15 0 560 Example 252 90 15 10 420 Example 253 70 15 30 220 Com.Ex. 241 40 15 60 Examples 254 and 255 The pellets which obtained in Examples 246 and 250 by blending the aromatic polyether ketone with the liquid crystal type aromatic polyimide in a ratio of 90 : 10 were injection molded at a injection temperature of 360∼400 °C and mold temperature of 160°C. Mechanical properties of molded specimens were measured and results are illustrated in Table 65. Tensile strength, tensile elastic modulus and elongation were measured in accordance with ASTM D-638. The mixture of the aromatic polyether ketone and the liquid crystal type aromatic polyimide in a proportion of these examples had mechanical properties equivalent to the aromatic polyether ketone alone in Comparative Examples 242 and 243. Thus, mechanical properties were not decreased even though the liquid crystal type aromatic polyimide was mixed in the range of the invention. Comparative Examples 242 and 243 Pellets obtained in Comparative Examples 234 and 238 were injection molded by the same procedures as carried out in Example 254 and 255, and mechanical properties of molded specimens were measured. Results are illustrated in Table 65. Pellets used for 1olding Tensile strength (Kg/cm 2 ) Tensile slastic modulus (Kg/cm 2 ) Elongation (%) Comparative Example 242 Comparative Example 234 930 270 100 Example 254 Example 246 930 270 96 Comparative Example 243 Comparative Example 238 1070 300 50 Example 255 Example 250 1060 300 50

Claims: Use of one or more aromatic polyimides having liquid crystal properties as an additive for improving the melt processability of a thermoplastic resin, wherein a composition is prepared comprising 99.9 ∼ 50 parts by weight of one or more thermoplastic resins and 0.1 ∼ 50 parts by weight of one or more of said polyimides; and wherein the liquid crystal type aromatic polyimide is one or more liquid crystal type aromatic polyimide selected from the group consisting of A ○, B ○ and © below : A ○ A liquid crystal type aromatic polyimide comprising a fundamental skeleton having recurring structural units represented by the formula (1) : wherein R 1 ∼ R 5 are a hydrogen atom, fluorine atom, trifluoromethyl, methyl, ethyl, or cyano and may be the same or different, and R is a tetravalent radical having 6 ∼ 27 carbon atoms and being selected from the group consisting of a monoaromatic radical, a condensed polyaromatic radical and a noncondensed polyaromatic radical having aromatic rings connected to each other with a direct bond or a bridge member; B ○ A liquid crystal type, capped aromatic polyimide comprising a fundamental skeleton having recurring structural units represented by the above formula (1) and being capped at the polymer chain end thereof with aromatic dicarboxylic anhydride of the formula (2) : wherein Z is a divalent radical having 6∼15 carbon atoms and being selected from the group consisting of a monoaromatic radical, a condensed polyaromatic radical, and a noncondensed polyaromatic radical having aromatic rings connected to each other with a direct bond or a bridge member; © A liquid crystal type, capped aromatic polyimide comprising a fundamental skeleton having recurring structural units represented by the above formula (1) and being capped at the polymer chain end thereof with aromatic monoamine of the formula (3) : V-NH 2 wherein V is a monovalent radical having 6∼15 carbon atoms and being selected from the group consisting of a monoaromatic radical, a condensed polyaromatic radical and a noncondensed polyaromatic radical having aromatic rings connected to each other with a direct bond or a bridge member. The use of claim 1 wherein the liquid crystal type aromatic polyimide is one or more liquid crystal type aromatic polyimide selected from A, B and C as defined in claim 1 with the further limitation that said fundamental skeleton has recurring structural units of the formula (4) : The use of claim 1 wherein the liquid crystal type aromatic polyimide is one or more liquid crystal type aromatic polyimides selected from A, B and C as defined in claim 1 with the further limitation that 1∼99 % by mol of the fundamental skeleton (1) has recurring structural units of the formula (4) : The use of any of claims 1∼3 wherein the thermoplastic resin is one or more thermoplastic resin selected from the group consisting of aromatic polyimide, aromatic polyetherimide, aromatic polyamideimide, aromatic polyethersulfone and aromatic polyether ketone. The use of claim 4 wherein the thermoplastic resin aromatic polyimide is one or more aromatic polyimides selected from the group consisting of D ○, E ○ and F ○ below : D ○ An aromatic polyimide comprising a fundamental skeleton having recurring structural units represented by the formula (5): wherein X is a divalent radical selected from the group consisting of a direct bond, isopropylidene, hexafluorinated isopropylidene, carbonyl, thio and sulfonyl, and R is a tetravalent radical having 6∼27 carbon atoms and being selected from the group consisting of a monoaromatic radical, a condensed polyaromatic radical and a noncondensed polyaromatic radical having aromatic rings connected to each other with a direct bond or a bridge member; E ○ A capped aromatic polyimide comprising a fundamental skeleton having recurring structural units represented by the above formula (5) and being obtained by capping the polymer chain end thereof with aromatic dicarboxylic anhydride of the formula (2) : wherein Z is a divalent radical having 6∼15 carbon atoms and being selected from the group consisting of a monoaromatic radical, a condensed polyaromatic radical, and a noncondensed polyaromatic radical having aromatic rings connected to each other with a direct bond or a bridge member ; F ○ A capped aromatic polyimide comprising a fundamental skeleton having recurring structural units represented by the formula (5) and being obtained by capping the polymer chain end thereof with aromatic monoamine of the formula (3) : V-NH 2 wherein V is a monovalent radical having 6∼15 carbon atoms and being selected from the group consisting of a monoaromatic radical, a condensed polyaromatic radical and a noncondensed polyaromatic radical having aromatic rings connected to each other with a direct bond or a bridge member. The use of claim 5 wherein the thermoplastic resin aromatic polyimide comprises a fundamental skeleton having recurring structural units of the formula (6): The use of claim 4 wherein the aromatic polyimide is one or more aromatic polyimides selected from the group consisting of G ○, H ○, and I ○ below: G ○ An aromatic polyimide comprising a fundamental skeleton having recurring structural units of the formula (7): H ○ A capped aromatic polyimide comprising a fundamental skeleton having recurring structural units of the above formula (7) and being obtained by capping the polymer chain end thereof with aromatic dicarboxylic anhydride of the formula (2): wherein Z is a divalent radical having 6∼15 carbon atoms and being selected from the group consisting of a monoaromatic radical, a condensed polyaromatic radical, and a noncondensed polyaromatic radical having aromatic rings connected to each other with a direct bond or a bridge member ; I ○ A capped aromatic polyimide comprising a fundamental skeleton having recurring structural units of the formula (5) and being obtained by capping the polymer chain end thereof with aromatic monoamine of the formula (3): V-NH 2 wherein V is a monovalent radical having 6∼15 carbon atoms and being selected from the group consisting of a monoaromatic radical, a condensed polyaromatic radical and a noncondensed polyaromatic radical having aromatic rings connected to each other with a direct bond or a bridge member. The use of claim 4 wherein the aromatic polyimide is one or more aromatic polyimides selected from the group consisting of J ○, K ○ and L ○ below: J ○ An aromatic polyimide copolymer comprising 99∼1 % by mol of a fundamental skeleton having recurring structural units of the formula (6): and 1∼99 % by mol of a fundamental skeleton having recurring structural units of the formula (8) provided that they are not of the formula (6): wherein R is wherein n is an integer of 0, 1, 2 or 3: Q is a direct bond, -O-, -S-, -CO-, -SO 2 -, -CH 2 -, -C(CH 3 ) 2 - or -C(CF 3 ) 2 - and may be the same or different when two or more Q connect three or more aromatic rings to each other; and R" is one or more tetravalent radicals selected from the group consisting of wherein M is one or more divalent radicals selected from the group consisting of and K ○ A capped aromatic polyimide copolymer obtained by capping the polymer chain end of the above aromatic polyimide copolymer with aromatic dicarboxylic anhydride of the formula (2) : wherein Z is a divalent radical having 6∼15 carbon atoms and being selected from the group consisting of a monoaromatic radical, a condensed polyaromatic radical, and a noncondensed polyaromatic radical having aromatic rings connected to each other with a direct bond or a bridge member; L ○ A capped aromatic polyimide copolymer obtained by capping the polymer chain end of the above aromatic polyimide copolymer with aromatic monoamine of the formula (3) : V-NH 2 wherein V is a monovalent radical having 6∼15 carbon atoms and being selected from the group consisting of a monoaromatic radical, a condensed polyaromatic radical and a noncondensed polyaromatic radical having aromatic rings connected to each other with a direct bond or a bridge member. The use of claim 8 wherein the recurring structural units of the formula (8) are recurring structural units of the formula (10), provided that they are not of the formula (6): wherein R is the same as above. The use of claim 4 wherein the aromatic polysulfone comprises a fundamental skeleton having one or more recurring structural units represented by the formula (11) : wherein X is a direct bond, The use of claim 4 wherein the aromatic polyetherimide comprises a fundamental skeleton having one or more recurring structural units represented by the formula (12) : wherein X is or and Y is The use of claim 4 wherein the aromatic polyamideimide comprises a fundamental skeleton having one or more recurring structural units of the formula (13) : and/or the formula (14) : The use of claim 4 wherein the aromatic polyether ketone comprises a fundamental skeleton having recurring structural units of the formula (15) : and/or the formula (16) : The use of any preceding claim wherein the aromatic dicarboxylic anhydride is phthalic anhydride. The use of any of claims 1-13 wherein the aromatic monoamine is aniline.

Inventors: ASANUMA TADASHI, KOGA NOBUHITO, OIKAWA HIDEAKI, OKAWA YUICHI, YAMAGUCHI AKIHIRO, ASANUMA, TADASHI, KOGA, NOBUHITO, OIKAWA, HIDEAKI, OKAWA, YUICHI, YAMAGUCHI, AKIHIRO
Applicants: MITSUI CHEMICALS INC, MITSUI CHEMICALS, INC.
Application year: 1993
Main classification: C08L81
IPC codes: C08L81, C08L71, C08G73, C08L79