Resin composition

Abstract: The present invention provides a resin composi­ tion comprising: (a) a polyolefin resin in an amount of 20-95% by weight, (b) a polyphenylene ether resin in an amount of 80-5% by weight, (c) a partially hydrogenated alkenyl aromatic compound-isoprene block copolymer in an amount of 3-45 parts by weight based on totally 100 parts by weight of the components (a) and (b), and (d) an ethylene-α-olefin copolymer elastomer modified by grafting thereon a graft monomer such as an unsaturated monocarboxylic acid or a derivative thereof, an unsaturated dicarboxylic acid or a derivative thereof, a styrene compound, or an unsaturated epoxy compound or an α-olefin-alkyl (meth)acrylate copolymer such as a copolymer of an α-olefin of 2-6 carbon atoms and an alkyl (meth)acrylate having an alkyl group of 1-8 carbon atoms in an amount of 3-45 parts by weight based on totally 100 parts by weight of the components (a) and (b).

Description: The present invention relates to a resin composition which shows especially excellent balance of mechanical properties including mainly rigidity and is superior in processability, oil resistance and chemical resistance. More particularly, it relates to a resin composition for injection molding, extrusion molding or blow moding which comprises a polyolefin, especially, a crystalline polyolefin, a polyphenylene ether resin, a partially hydrogenated alkenyl aromatic compound-isoprene block copolymer, and a specific ethylene-α-olefin copolymer elastomer or an α-olefin-alkyl (meth)acrylate copolymer and which is excellent in balance of mechanical properties of mainly rigidity and heat resistance superior in processability, organic solvent resistance and chemical resistance. Polyolefins are superior in processability, toughness, water resistance, organic solvent resistance and chemical resistance, low in specific gravity and inexpensive and hence have been widely used for production of various shaped articles and sheets. However, they suffer from the problem in heat resistance, which has hindered development of new uses thereof. On the other hand, polyphenylene ether resins have excellent heat resistance, but have difficulties in processability and solvent resistance, which impose limitation on the scope of application. For improvement of processability and impact strength, blends of polyphenylene ether resin with a styrene resin is utilized, but these have a defect in solvent resistance and are limited in scope of application. For example, the blend is not suitable in the field which requires resistance to oily solvents such as gasoline. In an attempt to utilize the respective merits of these polyolefin and polyphenylene ether resins and offset their defects, various blend compositions have been proposed. For example, a composition has been proposed for improvement of processability and tensile strength JP-B-42-7069). However, this composition does not necessarily suffice the relatively high level of mechanical strength which is required in industrial fields. Furthermore, for improving compatibility between polyolefin and polyphenylene ether resins to enhance mechanical strength, for example, a composition to which a styrene-butadiene block copolymer or its hydrogenated product is added (JP-A-53-71158, 54-88960 and 59-100159) and the above composition to which an inorganic filler is added (JP-A-58-103556) have been proposed. According to these proposals, processability and mechanical strength can be improved, but the organic solvent resistance possessed by the polyolefin cannot be sufficiently exhibited for the reasons that the amount of polyolefin added is smaller or the matrix (continuous phase) comprises a polyphenylene ether resin or a combination of polyphenylene ether resin and styrene resin. Moreover, there has been proposed a composition which comprises polyphenylene ether and a large amount (more than 20% by weight) of polyolefin to which are further added a diblock copolymer or radial teleblock copolymer composed of an alkenyl aromatic compound and a conjugated diene or hydrogenated polymers thereof as a compatibilizing agent (JP-A-58-103557 and 60-76547). That is, it is said that a blend of a low-density polyethylene as polyolefin and polyphenylene ether resin has been improved in compatibility and can be improved in tensile characteristics and fragility by the addition of a hydrogenated product of an alkenyl aromatic compound - conjugated diene block copolymer. However, improvement only in compatibility is not enough to satisfy various properties required for common resins. For example, the composition disclosed in JP-A-60-76547, namely, a resin composition comprising the three components of a polyphenylene ether, a low-density polyethylene as polyolefin, a component of large amount, and a hydrogenated product of alkenyl aromatic compound-conjugated diene block copolymer as a compatibilizing agent for the former two components has limitation in its use owing to its very low rigidity level. Among the above-mentioned combinations, resin compositions which contain polypropylene as polyolefin are somewhat improved in rigidity and heat resistance, but these are still not enough in practical use and further improvement has been desired. It is the object of the present invention to provide resin compositions which can satisfy the balance of mechanical strength of relatively high level and solvent resistance and processability of relatively high level which are required in various uses such as in the field of industrial parts. This object could be achieved on the basis of the finding that a resin composition which shows excellent balance of mechanical properties and is superior in solvent resistance and processability can be obtained by adding a hydrogenated product of an alkenyl aromatic compound-conjugated diene block copolymer of a specific structure and an alkenyl aromatic compound-conjugated diene block copolymer to a combination of a polyphenylene ether resin and a polyolefin, preferably crystalline polyolefin. The subject matter of the present invention is a resin composition which comprises: (a) a polyolefin resin in an amount of 20-95% by weight, based on the total weight of (a) and (b). (b) a polyphenylene ether resin in an amount of 80-5% by weight, based on the total weight of (a) and (b), (c) a partially hydrogenated alkenyl aromatic compound-isoprene block copolymer in an amount of 3-45 parts by weight based on a total of 100 parts by weight of the components (a) and (b), and (d) a copolymer elastomer or copolymer selected from the group consisting of an ethylene-α-olefin copolymer elastomer modified with an unsaturated monocarboxylic acid or a derivative thereof, an unsaturated dicarboxylic acid or a derivative thereof, a styrene compound or an unsaturated epoxy compound and a copolymer of α-olefin of 2-6 carbon atoms and alkyl (meth)acrylate having an alkyl group of 1-8 carbon atoms in an amount of 3-45 parts by weight based on a total of 100 parts by weight of the components (a) and (b). Component (a): Polyolefin resin: Polyolefins used in the present invention include, for example, homopolymers of α-olefins of 3 or more carbon atoms such as propylene, butene-1, pentene-1, hexene-1, 3-methylbutene-1, 4-methylpentene-1, heptene-1, and octene-1, copolymers containing a predominant amount of these α-olefins and at least one other α-olefin including ethylene in the form of a random copolymer or block copolymer and mixtures thereof, copolymers such as random, block, and graft copolymers of a predominant amount of α-olefins of 3 or more carbon atoms and at least one other unsaturated monomer, and oxidized, halogenated or sulfonated products of these polymers. Preferred are those which are at least partially crystalline. As the other unsaturated monomers, there may be used unsaturated organic acids or derivatives thereof such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, methyl acrylate, ethyl acrylate, methyl methacrylate, maleic anhydride, arylmaleic acid amide, and alkylmaleic acid imide; vinyl esters such as vinyl acetate and vinyl butyrate; aromatic vinyl compounds such as styrene and methylstyrene; vinyl silanes such as vinyltrimethylmethoxysilane and γ-methacryloyloxypropyltrimethoxysilane; and non-conjugated dienes such as dicyclopentadiene, 4-ethylidene-2-norbornene, 4-methyl-1,4-hexadiene and 5-methyl-1,4-hexadiene. In case of copolymers, these may comprise not only two of α-olefins or other monomers, but also more than two of them. These polymers can be obtained by polymerization or modification according to known processes and besides, commercially available polymers may be optionally chosen and used. Combination of them can naturally be employed. Among them, preferred are homopolymers of propylene, butene-1,3-methylbutene-1 or 4-methylpentene-1 and copolymers containing a predominant amount of these monomers. Among them, crystalline propylene polymers, namely, crystalline propylene homopolymer, crystalline propylene copolymers such as crystalline propylene-ethylene block or random copolymer, and mixtures of these crystalline propylene polymers with α-olefin rubbers, namely, rubber like copolymers comprising a plurality of α-olefins or rubber-like copolymers of a plurality of α-olefins and non-conjugated dienes are especially preferred from the point of balance in mechanical properties. The melt flow rate (MFR) (230°C, load 2.16 kg) of these crystalline propylene polymers and mixtures containing these crystalline propylene polymers and α-olefin rubbers is preferably within the range of 0.01-400 g/10 min, more preferably within the range of 0.15-60 g/10 min. If the MFR is less than 0.01 g/10 min, the compsoition often has problems in processability and if it is more than 400 g/10 min, the level of mechanical strength is low and this is not preferred. Polyolefins include those which have come to have an MFR within the above range by allowing polyolefins having smaller MFR, namely, larger molecular weight to undergo a change in molecular weight according to known method, for example, heat treatment in the presence or absence of a free-radical initiator (organic or inorganic peroxides, organotin compounds, organic azo compounds) or heating and mechanical shearing at melt kneading. Component (b): Polyphenylene ether resin The polyphenylene ether resin used in the present invention has a recurring unit represented by the following formula: wherein the ether oxygen atom in one unit is linked to the benzene nucleus in the next adjacent unit; n is at least 30; a plurality of R each represents a monovalent substituent selected from the group consisting of hydrogen, halogen, a hydrocarbon group containing no tertiary α-carbon atom, a halohydrocarbon group having at least two carbon atoms between a halogen atom and the phenyl nucleus, a hydrocarbon oxy group and a halohydrocarbon oxy group having at least two carbon atoms between a halogen atom and the phenyl nucleus. Typical examples of polyphenylene ethers are the following and analogues thereof. Poly(2,6-dimethyl-1,4-phenylene) ether, Poly(2,6-diethyl-1,4-phenylene) ether, Poly(2-methyl-6-ethyl-1,4-phenylene) ether, Poly(2-methyl-6-propyl-1,4-phenylene) ether, Poly(2,6-dipropyl-1,4-phenylene) ether, Poly(2-ethyl-6-propyl-1,4-phenylene) ether, Poly(2,6-dibutyl-1,4-phenylene) ether, Poly(2,6-dipropenyl-1,4-phenylene) ether, Poly(2,6-dilauryl-1,4-phenylene) ether, poly(2,6-diphenyl-1,4-phenylene) ether, Poly(2,6-dimethoxy-1,4-phenylene) ether, Poly(2,6-diethoxy-1,4-phenylene) ether, Poly(2-methoxy-6-ethoxy-1,4-phenylene) ether, Poly(2-ethyl-6-stearyloxy-1,4-phenylene) ether, Poly(2,6-dichloro-1,4-phenylene) ether, Poly(2-methyl-6-phenyl-1,4-phenylene) ether, Poly(2,6-dibenzyl-1,4-phenylene) ether, Poly(2-ethoxy-1,4-phenylene) ether, Poly(2-chloro-1,4-phenylene) ether, Poly(2,5-dibromo-1,4-phenylene) ether. Further examples are copolymers such as a copolymer of 2,6-dimethylphenol and 2,3,6-trimethylphenol, a copolymer of 2,6-dimethylphenol and 2,3,5,6-tetramethylphenol and a copolymer of 2,6-diethylphenol and 2,3,6-trimethylphenol. The polyphenylene ethers used in the present invention further include modified polyphenylene ethers such as polyphenylene ethers defined by the above-mentioned formula on which a styrene monomer (e.g., styrene, p-methylstyrene, and α-methylstyrene) is grafted. Processes for preparation of these polyphenylene ethers have been known as disclosed, for example, in US-A-3306874, 3306875, 3257357, and 3257358, JP-B-52-17880 and JP-A-50-51197. Polyphenylene ethers preferred for attaining the object of the present invention are those which have alkyl substituents in the two ortho positions in respect to the ether oxygen atom and copolymers of 2,6-dialkylphenols and 2,3,6-trialkylphenols. Among them, polymers of 2,6-dimethylphenol are especially preferred. Further, the molecular weight of the polyphenylene ethers in terms of intrinsic viscosity measured in chloroform at 25°C is preferably within the range of 0.2-0.7 dl/g, more preferably within the range of 0.25-0.6 dl/g and further preferably within the range of 0.3-0.55 dl/g. If the intrinsic viscosity is less than 0.2 dl/g, the mechanical strength of the composition is insufficient and if it is more than 0.7 dl/g, the processability of the composition is deteriorated. Component (c): Partially hydrogenated alkenyl aromatic compound-isoprene copolymer: The partially hydrogenated alkenyl aromatic compound-isoprene block copolymer used in the present invention is an alkenyl aromatic compound-isoprene block copolymer which has a structure containing at least one chain block "A" originating from the alkenyl aromatic compound and at least one chain block "B" originating from the isoprene and in which the content of aliphatic unsaturated groups in the block B is reduced by hydrogenation. The arrangement of block A and block B includes a linear structure and branched structure, so-called radial teleblock structure. The distribution of monomer components is not critical and may be uniform or ununiform and furthermore may be tapered with increase or decrease in the amount of monomer components along the molecular chain. Therefore, the respective molecular weights of a plurality of block A and block B may be the same or different. Moreover, a part of these structures may contain random chains originating from random copolymer portions of alkenyl aromatic compound and isoprene. Among them, preferred are linear structures such as diblock (A-B blocks), triblock (A-B-A blocks, B-A-B blocks), tetrablock (A-B-A-B blocks), pentablock (A-B-A-B-A blocks, B-A-B-A-B blocks) and those which have totally 6 or more A and B blocks. More preferred are diblock, triblock and tetrablock structures and an A-B diblock structure is especially preferred. The alkenyl aromatic compound which constitutes block A has the chemical structure represented by the following formula: wherein R¹ and R² each represents a hydrogen atom or a lower alkyl or alkenyl group of 1-6 carbon atoms, R³ and R⁴ each represents a hydrogen atom, a lower alkyl group of 1-6 carbon atoms, a chlorine atom or a bromine atom, and R⁵, R⁶ and R⁷ each represents a hydrogen atom or a lower alkyl or alkenyl group of 1-6 carbon atoms and R⁶ and R⁷ may be linked together with a hydrocarbyl group to form a naphthyl group together with the benzene ring. Examples of the alkenyl aromatic compound include styrene, p-methylstyrene, α-methylstyrene, vinylxylene, vinyltoluene, vinylnaphthalene, divinylbenzene, bromostyrene and chlorostyrene and these may also be used in combination. Among them, styrene, α-methylstyrene, p-methylstyrene, vinyltoluene, and vinylxylene are preferred and styrene is more preferred. The proportion of the recurring unit originating from the alkenyl aromatic compound in the partially hydrogenated alkenyl aromatic compound-isoprene block copolymer (c) is preferably more than 20% by weight and at most 80% by weight, more preferably 25-65% by weight. If the proportion is more than 80% by weight, impact strength of the resin composition is deteriorated to an unsatisfactory level and if it is 20% by weight or less, the rigidity level and heat resistance of the resin composition are insufficient and the object of the present invention cannot be attained. In the aliphatic chain portion of the block copolymer (c), the proportion of unsaturated bonds originating from isoprene and remaining without being hydrogenated is preferably 50% by weight or less, more preferably 20% by weight or less, further preferably 10% by weight or less. Further, about 25% by weight or less of aromatic unsaturated bonds originating from the alkenyl aromatic compound may be hydrogenated. The hydrogenated block copolymer (c) has a number-average molecular weight (obtained according to the polystyrene conversion method from values measured by gel permeation chromatography) of preferably 5,000-500,000 g/mol, more preferably 10,000-300,000 g/mol, still further preferably 30,000-200,000, especially 45,000-150,000 g/mol. If the number-average molecular weight is more than 500,000 g/mol or less than 5,000 g/mol, production cost is apt to increase. The measurement by gel permeation chromatography was carried out using monodispersed polystyrene as standard material in obtaining relation between elution time and molecular weight. The average molecular weight was in terms of polystyrene. The molecular weight distribution of the hydrogenated block copolymer (c) can be measured by the above gel permeation chromatography, but preferably the molecular weight distribution is not limited and besides so-called value Q obtained by dividing the value of weight-average molecular weight by that of number-average molecular weight may be within any range. Moreover, the molecular weight distribution may have not only one peak, but also two or more peaks. Moreover, the block copolymer (c) may be such that it contains, in addition to the component of the peak of main dispersion, a small amount of components of higher or lower molecular weight than that of the component of the peak of main dispersion, in other words, having a shape of molecular weight distribution comprising a peak of main dispersion having the foot descending by a gradual slope. The alkenyl aromatic chain block (block A) and the hydrogenated isoprene chain block (block B) in the hydrogenated block copolymer (c) may be of any molecular weight as far as it satisfies the above-mentioned number-average molecular weight and including any combinations. These hydrogenated block copolymers (c) have a hydrogenated isoprene polymer chain portion and some of them show crystallinity originating from this chain. It is considered that this is because the hydrogenated isoprene polymer chain has a molecular structure similar to a polyolefin. Crystallinity of the hydrogenated block copolymer (c) can be measured by differential scanning calorimeter (DSC). The hydrogenated block copolymers (c) usable in the present invention may be of any crystallinity. The hydrogenated block copolymers (c) may have any glass transition temperatures based on the hydrogenated isoprene polymer chain portion. The glass transition temperature can be measured by the above-mentioned DSC method or based on the change of viscoelasticity with the temperature measured by a mechanical spectrometer. Many processes have been proposed for producing alkenyl aromatic compound-isoprene block copolymers. Typical processes are disclosed, for example, in JP-B-40-23798 and US-A-3595942 and 4090996. According to these processes, block copolymerization is carried out in an inert solvent such as cyclohexane using e.g. a lithium catalyst or Ziegler catalyst. One of these block copolymers is supplied from Japan Synthetic Rubber Co., Ltd. by the trademark of "TR2400". Hydrogenation treatment of these block copolymers is carried out by hydrogenation in an inert solvent such as cyclohexane in the presence of hydrogenation catalyst according to the processes disclosed in JP-B-42-8704, 43-6636 and 46-20814. Furthermore, it is also possible to carry out hydrogenation in an inert solvent using p-toluenesulfonylhydroazide by the process disclosed in "Journal of Polymer Science Part B Polymer Letters, Volume 11, pages 427-434 (1973). Component (d): (1) Modified ethylene elastomers: Modified ethylene-α-olefin copolymers used in the present invention are ethylene-α-olefin copolymers on which is grafted an unsaturated monocarboxylic acid or derivative thereof, an unsaturated dicarboxylic acid or derivative thereof, a styrene compound or an unsaturated epoxy compound. The ethylene-α-olefin copolymer which is to be subjected to graft modification has an ethylene content of 30-93 mol%, preferably 35-90 mol%. If the ethylene content is more than 93 mol% or less than 30 mol%, the ethylene-α-olefin copolymer becomes highly crystalline and the effect to improve the impact resistance of the composition is not sufficient. Furthermore, the melt flow rate of the ethylene-α-olefin copolymer at 190°C [MFR, measured at 190°C under a load of 2160 g (ASTM D-1238 Condition E)] is preferably 0.1-50 g/10 min, especially preferably 0.2-20 g/10 min. If the MFR is less than 0.1 g /10 min or more than 50 g/10 min, the effect to improve the impact resistance tends to decrease. The density of the ethylene-α-olefin copolymer is preferably 0.90 g/cm³ or less, more preferably 0.85-0.89 g/cm³. Moreover, the ethylene-α-olefin copolymer is preferably low-crystalline or non-crystalline and the crystallinity is usually 0-50%, preferably 0-40%. The α-olefin unit which constitutes the ethylene-α-olefin copolymer is an α-olefin of 3-18 carbon atoms such as 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-decene. These may be used singly or as mixtures of two or more. The ethylene-α-olefin copolymer is usually a copolymer of ethylene component and α-olefin component, but may contain a diene component in an amount of at most 5 mol%. Typical examples of the diene component are dicyclopentadiene and ethylidene norbornane. Graft monomers to be grafted on the ethylene-α-olefin copolymer are one or more compounds selected from unsaturated monocarboxylic acids and derivatives thereof, one or more compounds selected from unsaturated dicarboxylic acids or derivatives thereof, one or more styrene compounds or one or more unsaturated epoxy compounds. As examples of the unsaturated monocarboxylic acids and derivatives thereof, mention may be made of methacrylic acid, acrylic acid, isocrotonic acid, crotonic acid, vinylacetic acid, pentenoic acid, angelic acid, tiglic acid, 2-pentenoic acid, 3-pentenoic acid, α-ethylacrylic acid, β-methylcrotonic acid, 4-pentenoic acid, 2-hexenoic acid, 2-methyl-2-pentenoic acid, 3-methyl-2-pentenoic acid, α-ethylcrotonic acid, 2,2-dimethyl-3-butenoic acid, 2-heptenoic acid, 2-octenoic acid, 4-decenoic acid, 9-undecenoic acid, 10-undecenoic acid, 4-dodecenoic acid, 5-dodecenoic acid, 4-tetradecenoic acid, 9-tetradecenoic acid, 9-hexadecenoic acid, 2-octadecenoic acid, 9-octadecenoic acid, eicosenoic acid, docosenoic acid, erucic acid, tetracosenoic acid, mycolipenic acid, 2,4-pentadienoic acid, 2,4-hexadienoic acid, diallylacetic acid, geranic acid, 2,4-decadienoic acid, 2,4-dodecadienoic acid, 9,12-hexadecadienoic acid, 9,12-octadecadienoic acid, hexadecatrienoic acid, linolic acid, linoleic acid, octadecatrienoic acid, eicosadienoic acid, eicosatrienoic acid, eicosatetraenoic acid, ricinolic acid, eleostearic acid, oleic acid, eicosapentaenoic acid, erucic acid, docosadienoic acid, docosatrienoic acid, docosatetraenoic acid, docosapentaenoic acid, tetracosenoic acid, hexacosenoic acid, hexacodienoic acid, octacosenoic acid, and tetracosenoic acid. Derivatives thereof include, for example, acid halides, amides, imides, anhydrides and esters. Among them, preferred are acrylic acid, methacrylic acid and methyl methacrylate. As examples of the unsaturated dicarboxylic acids and derivatives thereof to be grafted on the ethylene-α-olefin copolymer, mention may be made of unsaturated dicarboxylic acids such as maleic acid, tetrahydrophthalic acid, itaconic acid, fumaric acid, citraconic acid, and nadic acid (endo-cis-bicyclo[2,2,1]hepto-5-en-2,3-dicarboxylic acid) and derivatives thereof, e.g., acid halides, amides, imides, anhydrides and esters such as maleimide, maleic anhydride, citraconic anhydride, monomethyl maleate, dimethyl maleate, and glycidyl maleate. Among them, preferred are maleic anhydride, maleic acid, fumaric acid and nadic anhydride. The styrene compounds to be grafted on the ethylene-α-olefin copolymer are preferably the alkenyl aromatic compounds mentioned above. Other monomers copolymerizable with a predominant amount of the styrene compound may be used in combination with the styrene compound. Such monomers include, for example, acrylic acid, methacrylic acid, maleic acid, maleic anhydride, methyl acrylate, ethyl acrylate, methyl methacrylate, glycidyl methacrylate, glycidyl acrylate and maleimide. The unsaturated epoxy compounds to be grafted on the ethylene-α-olefin copolymer are compounds having both unsaturated bonds and epoxy groups in their molecule and examples thereof are glycidyl esters of unsaturated carboxylic acids. Examples of the unsaturated carboxylic acids are as follows: Acrylic acid, isocrotonic acid, crotonic acid, vinylacetic acid, pentenoic acid, angelic acid, tiglic acid, 2-pentenoic acid, 3-pentenoic acid, α-ethylacrylic acid, β-methylcrotonic acid, 4-pentenoic acid, 2-hexenoic acid, 2-methyl-2-pentenoic acid, 3-methyl-2-pentenoic acid, α-ethylcrotonic acid, 2,2-dimethyl-3-butenoic acid, 2-heptenoic acid, 2-octenoic acid, 4-decenoic acid, 9-undecenoic acid, 10-undecenoic acid, 4-dodecenoic acid, 5-dodecenoic acid, 4-tetradecenoic acid, 9-tetradecenoic acid, 9-hexadecenoic acid, 2-octadecenoci acid, 9-octadecenoic acid, eicosenoic acid, docosenoic acid, erucic acid, tetracosenoic acid, mycolipenic acid, 2,4-pentadienoic acid, 2,4-hexadienoic acid, diallylacetic acid, geranic acid, 2,4-decadienoic acid, 2,4-dodecadienoic acid, 9,12-hexadecadienoic acid, 9,12-octadecadienoic acid, hexadecatrienoic acid, linolic acid, linoleic acid, octadecatrienoic acid, eicosadienoic acid, eicosatrienoic acid, eicosatetraenoic acid, ricinolic acid, eleostearic acid, oleic acid, eicosapentaenoic acid, erucic acid, docosadienoic acid, docosatrienoic acid, docosatetraenoic acid, docosapentaenoic acid, tetracosenoic acid, hexacosenoic acid, hexacodienoic acid, octacosenoic acid, tetracosenoic acid, maleic acid, tetrahydrophthalic acid, itaconic acid, fumaric acid, citraconic acid, and nadic acid (endo-cis-bicyclo[2,2,1]hepto-5-en-2,3-dicarboxylic acid). Other examples of the unsaturated epoxy compounds are allylglycidyl ether, vinylglycidyl ether, and cyclohexene epoxide. These may be used singly or in combination of two or more. The graft ratio of the unsaturated monocarboxylic acid or derivatives thereof, the unsaturated dicarboxylic acids or derivatives thereof, and the unsaturated epoxy compounds as graft monomers is 0.05-10 parts by weight, especially 0.1-5 parts by weight based on 100 parts by weight of the ethylene-α-olefin copolymer. If the graft ratio is less than 0.05 part by weight, the compatibility with polyphenylene ether resins is inferior and laminar peeling is apt to occur and besides, the effect to improve the impact resistance is also apt to decrease. If the graft ratio is more than 10 parts by weight, the crosslinking degree of the graft modified product increases and even if it is added to polyphenylene ether resin, the effect to improve the impact resistance tends to decrease. The graft ratio of the styrene compounds as graft monomers is preferably 0.3-50 parts by weight, especially preferably 1-20 parts by weight based on 100 parts by weight of the ethylene-α-olefin copolymer. If the graft ratio is less than 0.3 part by weight, the compatibility with the polyphenylene ether resin is inferior and laminar peeling is apt to occur and besides, the effect to improve the impact resistance is small. If the graft ratio is more than 50 parts by weight, the graft modified products do not show properties of rubber-like elastic body and the effect to improve the impact resistance of the polyphenylene ether resin decreases. Further, melt flow rate of the graft-modified ethylene-α-olefin copolymer [MFR, measured at 190°C under 2,160 g] is 0.1-50 g/10 min, preferably 0.2-20 g/10 min. At least one compound selected from styrene hydrocarbons such as styrene can be used in combination with the unsaturated monocarboxylic acids or derivatives thereof, unsaturated dicarboxylic acids or derivatives thereof, or unsaturated epoxy compounds as graft monomers. In this case, it is preferred that the unsaturated monocarboxylic acids or derivatives thereof, unsaturated dicarboxylic acids or derivatives thereof, or unsaturated epoxy compounds are used in an amount of 0.05-10% by weight, especially 0.1-5% by weight per 100 parts by weight of the ethylene-α-olefin copolymer and the compound selected from the styrene hydrocarbons is used in an amount of 0.3-50% by weight, especially 1-20% by weight per 100 parts by weight of the ethylene-α-olefin copolymer. The modified ethylene-α-olefin copolymer used in the present invention is preferably prepared by subjecting the ethylene-α-olefin copolymer directly molten or dissolved in a solvent to graft reaction with addition of the above graft monomers and free-radical initiators. A reactor, extruder or kneader is utilized for the graft reaction. The free-radical initiators include organic peroxides and organic peresters such as benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(peroxide benzoate) hexyne-3, 1,4-bis(tert-butylperoxoisopropyl)benzene, lauroyl peroxide, tert-butyl peracetate, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, tert-butyl perbenzoate, tert-butyl perphenylacetate, tert-butyl perisobutyrate, tert-butyl per-sec-octoate, tert-butyl perpivalate, cumyl perpivalate and tert-butyl perdiethylacetate and azo compounds such as azobisisobutyronitrile and dimethylazoisobutyrate. Among them, preferred are dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and 1,4-bis(tert-butylperoxyisopropyl)benzene. Component (d): (2) α-olefin-alkyl (meth)acrylate copolymers: The α-olefin-alkyl (meth)acrylate copolymers used in the present invention are copolymers of one or more α-olefins of 2-6 carbon atoms (such as ethylene, propylene, and butene) with alkyl esters (having 1-8 carbon atoms) of acrylic acid or methacrylic acid. As examples of these copolymers, mention may be made of ethylene-methyl acrylate, ethylene-ethyl acrylate, ethylene-propylene-methyl acrylate, ethylene-propylene-ethyl acrylate, ethylene-butene-methyl acrylate, ethylene-butene-ethyl acrylate, ethylene-methyl methacrylate, ethylene-ethyl methacrylate, ethylene-propylene-methyl methacryalte, and ethylene-butene-methyl methacrylate copolymers. Among them, ethylene-methyl acrylate and ethylene-ethyl acrylate copolymers are especially preferred. The content of acrylate or methacrylate in the copolymer is preferably 3-30% by weight. Moreover, there may also be used the above copolymers into which is introduced a functional group selected from carboxylic acid group, acid anhydride group, acid amide group, imide group, hydroxyl group and epoxy group. Introduction of these functional groups can be easily carried out by grafting a compound having both the unsaturated bond and the above functional group on an α-olefin-alkyl(meth)acrylate copolymer or copolymerizing said compound with an α-olefin-alkyl (meth)acrylate. As examples of the functional compounds, mention may be made of unsaturated acid such as vinylacetic acid, methacrylic acid, pentenoic acid, angelic acid, tiglic acid, 2-pentenoic acid, 3-pentenoic acid, α-ethylacrylic acid, β-methylcrotonic acid, 4-pentenoic acid, 2-hexenoic acid, 2-methyl-2-pentenoic acid, 3-methyl-2-pentenoic acid, α-ethylcrotonic acid, 2,2-dimethyl-3-butenoic acid, 2-heptenoic acid, 2-octenoic acid, 4-decenoic acid, 9-undecenoic acid, 10-undecenoic acid, 4-dodecenoic acid, 5-dodecenoic acid, 4-tetradecenoic acid, 9-tetradecenoic acid, 9-hexadecenoic acid, 2-octadecenoic acid, 9-octadecenoic acid, eicosenoic acid, docosenoic acid, erucic acid, tetracosenoic acid, mycolipenic acid, 2,4-pentadienoic acid, 2,4-hexadienoic acid, diallylacetic acid, geranic acid, 2,4-decadienoic acid, 2,4-dodecadienoic acid, 9,12-hexadecadienoic acid, 9,12-octadecadienoic acid, hexadecatrienoic acid, linolic acid, linoleic acid, octadecatrienoic acid, eicosadienoic acid, eicosatrienoic acid, eicosatetraenoic acid, ricinolic acid, eleostearic acid, oleic acid, eicosapentaenoic acid, erucic acid, docosadienoic acid, docosatrienoic acid, docosatetraenoic acid, docosapentaenoic acid, tetracosenoic acid, hexacosenoic acid, hexacodienoic acid, octacosenoic acid, and tetracosenoic acid, maleic acid, tetrahydrophthaic acid, itaconic acid, fumaric acid, citraconic acid, and nadic acid (endo-cis-bicyclo[2,2,1]hepto-5-en-2,3-dicarboxylic acid) and acid anhydrides of these unsaturated acids (such as maleic anhydride and nadic anhydride), acid amides of these unsaturated acids (such as acrylic amide, dimethylaminopropylacrylamide and methacrylamide), acid imides of these unsaturated acids (such as maleimide, N-phenylmaleimide, and N-methylmaleimide), hydroxyesters of these unsaturated acids (such as hydroxyethyl acrylate and hydroxyethyl methacrylate), and glycidyl esters (such as glycidyl acrylate and glycidyl methacrylate). Further examples are allylglycidyl ether, vinylglycidyl ether, and cyclohexene epoxide. Suitable functional compounds are acrylic acid, methacrylic acid, acrylamide, maleic anhydride, nadic anhydride, glycidyl acrylate, glycidyl methacrylate, and maleimide. The content of these functional compounds in the copolymers is preferably 0.1-15% by weight, more preferably 0.5-10% by weight. Generally, free-radical initiators are used for introduction of the functional compounds. The free-radical initiators include organic peroxides and organic peresters such as benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(peroxide benzoate)hexyne-3, 1,4-bis(tert-butylperoxoisopropyl)benzene, lauroyl peroxide, tert-butyl peracetate, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, tert-butyl perbenzoate, tert-butyl perphenylacetate, tert-butyl perisobutyrate, tert-butyl per-sec-octoate, tert-butyl perpivalate, cumyl perpivalate and tert-butyl perdiethylacetate and azo compounds such as azobisisobutyronitrile and dimethylazoisobutyrate. Among them, preferred are dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and 1,4-bis(tert-butylperoxyisopropyl)benzene. Compositional ratio of components: The content of polyolefin component (a) in the resin composition of the present invention is 20-95% by weight, preferably 30-95% by weight, especially preferably 40-90% by weight when the total amount of polyolefin (a) and polyphenylene ether resin (b) is assumed to be 100% by weight. If the content is less than 20% by weight, the composition is insufficient in organic solvent resistance and if it is more than 95% by weight, heat resistance is in unsatisfactory level and the object of the present invention cannot be attained. Similarly, the content of polyphenylene ether resin, component (b), is 80-5% by weight, preferably 70-5% by weight and especially preferably 60-10% by weight when the total amount of component (a) and component (b) is assumed to be 100% by weight. If it is less than 5% by weight, the level of rigidity is insufficient and if it is more than 80% by weight, the organic solvent resistance is insufficient. The content of the partially hydrogenated alkenyl aromatic compound-isoprene block copolymer, the component (c), is 3-45 parts by weight, preferably 5-40 parts by weight, especially preferably 5-30 parts by weight based on a total of 100 parts by weight of component (a) and component (b). If it is less than 3 parts by weight, the level of impact strength is unsatisfactory and if it is more than 45 parts by weight, the level of rigidity is unsatisfactory and the object of the present invention cannot be attained. The content of the modified ethylene-α-olefin copolymer elastomer or the α-olefin-alkyl (meth)acrylate copolymer, component (d), is 3-45 parts by weight, preferably 5-30 parts by weight based on a total of 100 parts by weight of component (a) and component (b). If it is less than 3 parts by weight,the level of impact strength is insufficient and if it is more than 45 parts by weight, the, level of rigidity is unsatisfactory and the object of the present invention cannot be attained. The resin composition of the present invention may contain, in addition to the above components, auxiliary components as far as the effects of the present invention are not damaged. Examples of these components are antioxidants, weathering modifiers, nucleating agents for polyolefins, slip agents,inorganic or organic fillers and reinforcing agents, flame retardants, various colorants, antistatic agents, releasing agents, and a small amount of a free-radical former (organic peroxides) for molecular weight regulation of polyolefins. Furthermore, plasticizers such as triphenyl phosphate used for polyphenylene resins, and furthermore, fillers such as glass fiber, wollastonite, potassium titanate, whisker, mica, talc, and calcium carbonate are effective for improvement of balance of properties such as rigidity and improvement of processability, dimensional accuracy, and dimensional stability. Method of blending: As method of blending for obtaining the resin composition of the present invention, various methods can be employed which are generally used for blending of resins per se; resins and stabilizers or colorants or resins and fillers. For example, the respective components in the form of powder or particles are prepared as a homogeneously dispersed mixture in a Henschel mixer, super mixer, ribbon blender or V blender. Then, the mixture is melt kneaded by a twin-screw extruder, single-screw extruder, rolls, Banbury mixer, blast mill or melt kneader with Brabender Plastograph. The melt kneading temperature is usually 200-350°C. The thus obtained resin composition can be extruded into pellets after melt kneading. Application of the resin composition of the present invention: The resin composition of the present invention can be easily molded by molding methods generally applied to thermoplastic resins, namely, injection molding, extrusion molding or blow molding, among which injection molding is most preferred. Because of its good mechanical properties, the composition is suitable for automobile parts, specifically, exterior trim parts such as bumper, door, door panel, fender, ornament, emblem, wheel cover, engine hood, roof, and spoiler, internal trim parts such as instrument panel, console box, and trim, exterior parts of electrical equipments such as television, refrigerator, and so-called office automation equipments. The present invention will be explained by the following nonlimiting examples and comparative examples. Methods for measurement and evaluation: In the following Examples and Comparative Examples, properties were measured and evaluated under the following conditions. (1) MFR (for indication of flowability) MFR of polyolefin was measured according to JIS K 7210-1975. (2) Flexural modulus (for indication of rigidity): This was measured in accordance with ISO R 178-1974 Procedure 12 (JIS K 7203) using Instron tester. (3) Izod impact strength: This was measured in accordance with ISO R 180-1969 (JIS K 7110) (notched Izod impact strength) using Izod impact tester manufactured by Toyo Seiki Seisakusho Co., Ltd. (4) Heat distortion temperature (for indication of heat resistance) This was measured in accordance with ISO R 75-1958 Method A (JIS K 7207-1974 A) using an injection molded test piece subjected to annealing treatment at 100°C for 30 minutes. Reference Example 1 Preparation of acrylic acid-graft modified ethylene-propylene copolymer: 100 Parts by weight of ethylene-propylene copolymer [ESPRENE E-120 (trademark) manufactured by Sumitomo Chemical Co., Ltd.), 3 parts by weight of acrylic acid and 0.1 part by weight of 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3 were well mixed by a super mixer and the mixture was melt kneaded at 230°C by a twin-screw extruder [TEM-50 (trademark) manufactured by Toshiba Machine Co., Ltd.). It was confirmed by oxygen analysis that 2.1% by weight of acrylic acid was graft copolymerized in the resulting modified ethylene-propylene copolymer. Example 1 A propylene homopolymer [SUMITOMO NOBRENE D-501 (trademark) manufactured by Sumitomo Chemical Co., Ltd.], poly-(2,6-dimethylphenylene) ether (manufactured by Sumitomo Chemical Co., Ltd.), a hydrogenated styrene-isoprene block copolymer (hereinafter referred to as "hydrogenated SI") [KRATON G1701X (trademark) manufactured by Shell Chemical CO.), and the acrylic acid-grafted ethylene-propylene copolymer obtained in Reference Example 1 were mixed at a mixing ratio as shown in Table 1 by a super mixer. The resulting mixture was melt kneaded by a twin-screw extruder [TEM-50 manufactured by Toshiba Machine Co., Ltd.) at 260-280°C to obtain pellets. Measurement of properties was carried out and the results are shown in Table 1. Comparative Example 1 Pellets were prepared in the same manner as in Example 1 except that a hydrogenated styrene-butadiene-styrene block copolymer (hereinafter referred to as "hydrogenated SB") [KRATON G-1650 (trademark) manufactured by Shell Chemical Co.] was used in place of the hydrogenated styrene-isoprene block copolymer. Results of measurement of properties are shown in Table 1. Comparative Example 2 Pellets were prepared in the same manner as in Example 1 except that unmodified ethylene-propylene copolymer (ESPRENE E-120 (trademark) manufactured by Sumitomo Chemical Co., Ltd.) was used in place of the acrylic acid-grafted ethylene-propylene copolymer. Measurement of properties was conducted to obtain the results as shown in Table 1. Comparative Example 3 Pellets were prepared in the same manner as in Example 1 except that the acrylic acid-grafted ethylene-propylene copolymer was not used. Measurement of properties was conducted and the results are shown in Table 1. As can be seen from comparison of the results of Example 1 with those of Comparative Examples 1-3, the composition of the present invention where hydrogenated styrene-isoprene block copolymer and acrylic acid-modified ethylene-propylene copolymer were combined had peculiarly excellent properties. Examples 2-6 Pellets were prepared in the same manner as in Example 1 at a mixing ratio of the components as shown in Table 2 and properties were evaluated. The results are shown in Table 2. Components used in Table 2 are as follows: Polypropylene : Homopolymer: SUMITOMO NOBRENE D-501 (trademark) manufactured by Sumitomo Chemical Co., Ltd. Random copolymer: Propylene-ethylene random copolymer [SUMITOMO NOBRENE S-131 (trademark) manufactured by Sumitomo Chemical Co., Ltd.] Block copolymer: Propylene-ethylene block copolymer [SUMITOMO NOBRENE AS-171A (trademark) manufactured by Sumitomo Chemical Co., Ltd.] Polyphenylene ether; Poly-(2,6-dimethylphenylene) ether (manufactured by Sumitomo Chemical Co., Ltd.) Hydrogenated SI: KRATON G-1701X (trademark) manufactured by Shell Chemical Co. Modified ethylene-α-olefin copolymer : AA-EP(1): Acrylic acid-modified ethylene-propylene copolymer (obtained in Reference Example 1) AA-EP(2): Acrylic acid-modified ethylene-propylene-ethylidene norbornane copolymer (prepared as in Reference Example 1 except that ESPRENE E-501A was used in place of ESPRENE E-120) MAA-EP: Methacrylic acid-modified ethylene-propylene copolymer (prepared as in Reference Example 1 except that methacrylic acid was used in place of acrylic acid) MMA-EP: Methyl methacrylate-modified ethylene-propylene copolymer [ethylene/propylene=about 8/2 (molar ratio) and methyl methacrylate 1.3% by weight) AA-EB: Acrylic acid-modified ethylene-butene copolymer [ethylene/butene=about 8/2 (weight ratio) and acrylic acid 1.2% by weight] Reference Example 2 Preparation of maleic anhydride-graft modified ethylene-propylene copolymer: 100 Parts by weight of ethylene-propylene copolymer [ESPRENE E-120 (trademark) manufactured by Sumitomo Chemical Co., Ltd.), 2 parts by weight of maleic anhydride and 0.1 part by weight of dicumyl peroxide were well mixed by a super mixer and the mixture was melt kneaded at 230°C by a twin-screw extruder [TEM-50 (trademark) manufactured by Toshiba Machine Co., Ltd.). It was found that 1.1% by weight of maleic anhydride was graft copolymerized in the resulting modified ethylene-propylene copolymer. Example 7 A propylene homopolymer [SUMITOMO NOBRENE D-501 (trademark) manufactured by Sumitomo Chemical Co., Ltd.], poly-(2,6-dimethylphenylene) ether (manufactured by Sumitomo Chemical Co., Ltd.), a hydrogenated styrene-isoprene block copolymer (hereinafter referred to as "hydrogenated SI") [KRATON G1701X (trademark) manufactured by Shell Chemical Co.), and the maleic anhydride-grafted ethylene-propylene copolymer obtained in Reference Example 2 were mixed at a mixing ratio as shown in Table 3 by a super mixer. The resulting mixture was melt kneaded by a twin-screw extruder [TEM-50 manfuactured by Toshiba Machine Co., Ltd.) at 260-280°C to obtain pellets. Measurement of properties was carried out and the results are shown in Table 3. As can be seen from comparison of the results of Example 7 with those of Comparative Examples 1-3, the composition of the present invention where hydrogenated styrene-isoprene block copolymer and maleic anhydride-modified ethylene-propylene copolymer were combined had peculiarly excellent properties. Examples 8-13 Pellets were prepared in the same manner as in Example 7 at a mixing ratio of the components as shown in Table 4 and properties were evaluated. The results are shown in Table 4. Components used in Table 4 are as follows: Polypropylene : Homopolymer: SUMITOMO NOBRENE D-501 (trademark) manufactured by Sumitomo Chemical Co., Ltd. Random copolymer: Propylene-ethylene random copolymer [SUMITOMO NOBRENE S-131 (trademark) manufactured by Sumitomo Chemical Co., Ltd.] Block copolymer: Propylene-ethylene block copolymer [SUMITOMO NOBRENE AS-171A (trademark) manufactured by Sumitomo Chemical Co., Ltd.] Polyphenylene ether: Poly-(2,6-dimethylphenylene) ether (manufactured by Sumitomo Chemical Co., Ltd.) Hydrogenated SI: KRATON G-1701X (trademark) manufactured by Shell Chemical Co. Modified ethylene-α-olefin copolymer : M-EP(1): Maleic anhydride-modified ethylene-propylene copolymer (obtained in Reference Example 2) M-EP(2): Maleic anhydride-modified ethylene-propylene-ethylidene norbornane copolymer (prepared as in Reference Example 2 except that ESPRENE E-501A was used in place of ESPRENE E-120) M-EB: Maleic anhydride-modified ethylene-butene-1 copolymer [ethylene/butene=about 83/17 (weight ratio) and maleic anhydride 1.2% by weight] H-EP: Nadic anhydride-modified ethylene-propylene copolymer [ethylene/propylene=about 8/2 (molar ratio) and nadic anhydride 1.5% by weight] MA-EP: Maleic acid-modified ethylene-propylene copolymer [ethylene/propylene=about 5/5 (molar ratio) and maleic acid 1.1% by weight] Reference Example 3: Preparation of styrene-graft modified ethylene-propylene copolymer: 100 Parts by weight of ethylene-propylene copolymer [ESPRENE E-120 (trademark) manufactured by Sumitomo Chemical Co., Ltd.), 40 parts by weight of styrene, 500 parts by weight of water, 1.5 part by weight of benzoyl peroxide, 3 parts by weight of calcium phosphate and 3 parts by weight of polyethylene glycol were charged in a polymerization kettel and atmosphere in the tank was sufficiently replaced with nitrogen under stirring. Then, polymerization was allowed to proceed for 1 hour at 90°C and then for 1 hour at 110°C. Polystyrene in the resulting graft copolymer was extracted with methyl ethyl ketone and as a result it was confirmed that about 20% by weight of styrene was graft copolymerized in the copolymer. Example 14 A propylene homopolymer [SUMITOMO NOBRENE D-501 (trademark) manufactured by Sumitomo Chemical Co., Ltd.], poly-(2,6-dimethylphenylene) ether (manufactured by Sumitomo Chemical Co., Ltd.), a hydrogenated styrene-isoprene block copolymer (hereinafter referred to as "hydrogenated SI") [KRATON G1701X (trademark) manufactured by Shell Chemical Co.), and the styrene-grafted ethylene-propylene copolymer obtained in Reference Example 3 were mixed at a mixing ratio as shown in Table 5 by a super mixer. The resulting mixture was melt kneaded by a twin-screw extruder [TEM-50 manufactured by Toshiba Machine Co., Ltd.) at 260-280°C to obtain pellets. Measurement of properties was carried out and the results are shown in Table 5. As can be seen from comparison of the results of Example 14 with those of Comparative Examples 1-3, the composition of the present invention where hydrogenated styrene-isoprene block copolymer and styrene-modified ethylene-propylene copolymer were combined had peculiarly excellent properteis. Examples 15-18 Pellets were prepared in the same manner as in Example 14 at a mixing ratio of the components as shown in Table 6 and properties were evaluated. The results are shown in Table 6. Components used in Table 6 are as follows: Polypropylene : Homopolymer: SUMITOMO NOBRENE D-501 (trademark) manufactured by Sumitomo Chemical Co., Ltd. Random copolymer: Propylene-ethylene random copolymer [SUMITOMO NOBRE S-131 (trademark) manufactured by Sumitomo Chemical Co., Ltd.] Block copolymer: Propylene-ethylene block copolymer [SUMITOMO NOBRENE AS-171A (trademark) manufactured by Sumitomo Chemical Co., Ltd. Polyphenylene ether: Poly-(2,6-dimethylphenylene) ether (manfuactured by Sumitomo Chemical Co., Ltd.) Hydrogenated SI: KRATON G-1701X (trademark) manufacturec by Shell Chemical Co. Modified ethylene-α-olefin copolymer : S-EP:Styrene-graft modified ethylene-propylene copolymer (obtained in Reference Example 3) S-EPD: Styrene-graft modified ethylene-propylene-ethylidene norbornane copolymer (prepared as in Reference Example 3 except that ESPRENE E-501A was used in place of ESPRENE E-120) S-EB: Styrene-graft modified ethylene-butene copolymer [prepared as in Reference Example 3 except that ethylene-butene-1 copolymer (butene content: 15% by weight) was used in place of ESPRENE E-120) Reference Example 4: Preparation of glycidyl methacrylate-graft modified ethylene-propylene copolymer: 100 Parts by weight of ethylene-propylene copolymer [ESPRENE E-120 (trademark) manufactured by Sumitomo Chemical Co., Ltd.], 5 parts by weight of glycidyl methacrylate and 0.1 part by weight of dicumyl peroxide were well mixed by a super mixer and the mixture was melt kneaded at 230°C by a twin-screw extruder [TEM-50 (trademark) manufactured by Toshiba Machine Co., Ltd.). It was found that 2.1% by weight of glycidyl methacrylate was graft copolymerized in the resulting modified ethylene-propylene copolymer. Example 19 A propylene homopolymer [SUMITOMO NOBRENE D-501 (trademark) manufactured by Sumitomo Chemical Co., Ltd.], poly-(2,6-dimethylphenylene) ether (manufactured by Sumitomo Chemical Co., Ltd.), a hydrogenated styrene-isoprene block copolymer (hereinafter referred to as "hydrogenated SI") [KRATON G1701X (trademark) manufactured by Shell Chemical Co.], and the glycidyl methacrylate-grafted ethylene-propylene copolymer obtained in Reference Example 4 were mixed at a mixing ratio as shown in Table 7 by a super mixer. The resulting mixture was melt kneaded by a twin-screw extruder [TEM-50 manufactured by Toshiba Machine Co., Ltd.] at 260-280°C to obtain pellets. Measurement of properties was carried out and the results are shown in Table 7. As can be seen from comparison of the results of Example 19 with those of Comparative Examples 1-3, the composition of the present invention where hydrogenated styrene-isoprene block copolymer and glycidyl methacrylate-modified ethylene-propylene copolymer were combined had peculiarly excellent properties. Examples 20-24 Pellets were prepared in the same manner as in Example 19 at a mixing ratio of the components as shown in Table 8 and properties were evaluated. The results are shown in Table 8. Components used in Table 8 are as follows: Polypropylene : Homopolymer: SUMITOMO NOBRENE D-501 (trademark) manufactured by Sumitomo Chemical Co., Ltd. Random copolymer: Propylene-ethylene random copolymer [SUMITOMO NOBRENE S-131 (trademark) manufactured by Sumitomo Chemical Co., Ltd.] Block copolymer: Propylene-ethylene block copolymer [SUMITOMO NOBRE AS-171A (trademark) manufactured by Sumitomo Chemical Co., Ltd.] Polyphenylene ether: Poly-(2,6-dimethylphenylene) ether (manufactured by Sumitomo Chemical Co., Ltd.) Hydrogenated SI: KRAFTON G-1701X (trademark) manufactured by Shell Chemical Co. Modified ethylene-α-olefin copolymer : GMA-EP(1): Glycidyl methacrylate-modified ethylene-propylene copolymer (obtained in Reference Example 4) GMA-EP(2): Glycidyl methacrylate-modified ethylene-propylene-ethylidene norbornane copolymer (prepared as in Reference Example 4 except that ESPRENE E-501A was used in place of ESPRENE E-120) M-EP: Monoglycidyl maleate-modified ethylene-propylene copolymer [ethylene/propylene= about 8/2 (molar ratio), monoglycidyl maleate 2.3% by weight] GMA-EB: Glcyidyl methacrylate-modified ethylene-butene copolymer [ethylene/butene=about 8/2 (weight ratio) and glycidyl methacrylate 1.3% by weight] Example 25 A propylene homopolymer [SUMITOMO NOBRENE D-501 (trademark) manufactured by Sumitomo Chemical Co., Ltd.], poly-(2,6-dimethylphenylene) ether (manufactured by Sumitomo Chemical Co., Ltd.), a hydrogenated styrene-isoprene block copolymer (hereinafter referred to as "hydrogenated SI") [KRATON G1701X (trademark) manufactured by Shell Chemical Co.), and ethylene-methyl acrylate-glycidyl methacrylate copolymer (methyl acrylate: about 50% by weight, glycidyl methacrylate: about 2% by weight) were mixed at a mixing ratio as shown in Table 9 by a super mixer. The resulting mixture was melt kneaded by a twin-screw extruder [TEM-50 manufactured by Toshiba Machine Co., Ltd.) at 260-280°C to obtain pellets. Measurement of properties was carried out and the results are shown in Table 9. As can be seen from comparison of the results of Example 25 with those of Comparative Examples 1-3, the composition of the present invention where hydrogenated styrene-isoprene block copolymer and ethylene-methyl methacrylate-glycidyl methacrylate copolymer were combined had peculiarly excellent properties. Examples 26-29 Pellets were prepared in the same manner as in Example 25 at a mixing ratio of the components as shown in Table 10 and properties were evaluated. The results are shown in Table 10. Components used in Table 10 are as follows: Polypropylene : Homopolymer: SUMITOMO NOBRENE D-501 (trademark) manufactured by Sumitomo Chemical Co., Ltd. Random copolymer: Propylene-ethylene random copolymer [SUMITOMO NOBRENE S-131 (trademark) manufactured by Sumitomo Chemical Co., Ltd.] Block copolymer: Propylene-ethylene block copolymer [SUMITOMO NOBRENE AS-171A (trademark) manufactured by Sumitomo Chemical Co., Ltd.] Polyphenylene ether: Poly-(2,6-dimethylphenylene) ether (manufactured by Sumitomo Chemical Co., ltd.) Hydrogenated SI: KRATON G-1701X (trademark) manufactured by Shell Chemical Co. α-Olefin-alkyl (meth)acrylate copolymer : EMA-GMA: Ethylene-methyl acrylate-glycidyl methacrylate copolymer (same as used in Example 25) E-EA: Ethylene-ethyl acrylate copolymer (ethyl acrylate: 18% by weight) E-EA-MAH: Ethylene-ethyl acrylate-maleic anhydride copolymer (ethyl acrylate: 20% by weight, maleic anhydride: 2% by weight) As explained above, the resin composition of the present invention has excellent balance in mechanical strengths and good solvent resistance and processability. The resin composition of the present invention can be easily molded into shaped articles very excellent in balance of properties such as impact resistance, heat resistance and solvent resistance and superior in uniformity and smoothness of appearance by ordinary molding methods such as injection molding, extrusion molding and blow molding.

Claims: A resin composition which comprises: (a) a polyolefin resin in an amount of 20-95% by weight based on the total weight of (a) and (b), (b) a polyphenylene ether resin in an amount of 80-5% by weight based on the total weight of (a) and (b), wherein the polyphenylene ether resin (b) has an intrinsic viscosity of 0.2-0.7 dl/g, measured in chloroform at 25°C, and has recurring unit represented by the following formula: wherein the ether oxygen atom is linked to the benzene nucleus in the next adjacent unit, n is at least 30, a plurality of R each represents a hydrogen atom, a halogen atom, a hydrocarbon group containing no tertiary α-carbon atom, a halo-hydrocarbon group having at least two carbon atoms between a halogen atom and the phenyl nucleus, a hydrocarbon oxy group, or a halohydrocarbon oxy group having at least two carbon atoms between a halogen atom and the phenyl nucleus, (c) a partially hydrogenated alkenyl aromatic compound-isoprene block copolymer in an amount of 3-45 parts by weight based on a total of 100 parts by weight of the components (a) and (b), wherein the partially hydrogenated alkenyl aromatic compound-isoprene block copolymer (c) is an alkenyl aromatic compound-isoprene block copolymer which has a structure containing at least one chain block A originating from an alkenyl aromatic compound and at least one chain block B originating from isoprene, block A having the chemical structure represented by the following formula: wherein R¹ and R² each represents a hydrogen atom or a lower alkyl or alkenyl group of 1-6 carbon atoms, R³ and R⁴ each represents a hydrogen atom, a lower alkyl group of 1-6 carbon atoms, a chlorine atom or a bromine atom, and R⁵, R⁶ and R⁷ each represents a hydrogen atom or a lower alkyl or alkenyl group of 1-6 carbon atoms and R⁶ and R⁷ may be linked together with a hydrocarbyl group to form a naphthyl group together with the benzene ring and block A and block B form a linear and branched structure in which the content of block A is higher than 20% by weight and at most 80% by weight, the content of aliphatic unsaturated groups in block B is reduced by hydrogenation and some of block B show crystallinity originating from its chain, and (d) a modified ethylene-α-olefin copolymer elastomer or an α-olefin-alkyl (meth)acrylate copolymer in an amount of 3-45 parts by weight based on a total of 100 parts by weight of the components (a) and (b), wherein the modified ethylene-α-olefin copolymer (d) has an ethylene content of 30-93 mol% and a melt flow rate of 0.1-50 g/10 min at 190°C under 2,160 g, the α-olefin unit which constitutes the ethylene-α-olefin copolymer has 3-18 carbon atoms, and the modified ethylene-α-olefin copolymer (d) is obtainable by grafting on the ethylene-α-olefin copolymer an unsaturated monocarboxylic acid or a derivative thereof, an unsaturated dicarboxylic acid or a derivative thereof, a styrene compound, or an unsaturated epoxy compound having both unsaturated bond and epoxy group in a molecule using a reactor, extruder or kneader such that the graft ratio of the unsaturated monocarboxylic acid or derivative thereof, the unsaturated dicarboxylic acid or derivative thereof or the unsaturated epoxy compound is 0.05-10 parts by weight per 100 parts by weight of the ethylene-α-olefin copolymer and the graft ratio of the styrene compound is 0.3-50 parts by weight per 100 parts by weight of the ethylene-α-olefin copolymer and the α-olefin-alkyl (meth)acrylate copolymer (d) is a copolymer of one or more α-olefins of 2-6 carbon atoms with alkyl esters of acrylic or methacrylic acid in which the alkyl group has 1-8 carbon atoms. A resin composition according to claim 1, wherein the polyolefin resin (a) is a homopolymer of a predominant amount of α-olefin of 3 or more carbon atoms, copolymer of an α-olefin of 3 or more carbon atoms with at least one other α-olefin, a mixture thereof, copolymer of an α-olefin of 3 or more carbon atoms with at least one other unsaturated monomer or oxidized, halogenated or sulfonated product of the above polymer. A resin composition according to claim 1 or 2, wherein the polyolefin resin (a) is a crystalline propylene homopolymer or copolymer. A resin composition according to claim 3, wherein the crystalline propylene homopolymer or copolymer has a melt flow rate of 0.01-400 g/10 min. A resin composition according to any one of claims 1 to 4, wherein the alkenyl aromatic compound is styrene. A resin composition according to any one of claims 1 to 5, wherein the content of unsaturated bonds originating from the aliphatic unsaturated groups in block B and remaining without hydrogenation in block copolymer (c) is 50% by weight or less. A resin composition according to any one of claims 1 to 6, wherein the block copolymer (c) has a number-average molecular weight of 5,000-500,000 g/mol. A resin composition according to any one of claims 1 to 7, wherein the modified ethylene-α-olefin copolymer (d) has an ethylene content of 35-90 mol%. A resin composition according to any one of claims 1 to 8, wherein the modified ethylene-α-olefin copolymer (d) has a density of 0.90 g/cm or less. A resin composition according to any one of claims 1 to 9, wherein the unsaturated monocarboxylic acid or derivative thereof used to make the modified ethylene-α-olefin copolymer (d) is acrylic acid, methacrylic acid or methyl methacrylate. A resin composition according to any one of claims 1 to 10, wherein the unsaturated dicarboxylic acid or derivative thereof used to make the modified ethylene-α-olefin copolymer (d) is maleic anhydride, maleic acid, fumaric acid or nadic anhydride. A resin composition according to any one of claims 1 to 11, wherein the styrene compound used to make the modified ethylene-α-olefin copolymer (d) is an alkenyl aromatic compound used to make block copolymer (c). A resin composition according to any one of claims 1 to 12, wherein the unsaturated epoxy compound used to make the modified ethylene-α-olefin copolymer (d) is a glycidyl ester of an unsaturated carboxylic acid. A resin composition according to any one of claims 1 to 13, wherein the α-olefin-alkyl (meth)acrylate copolymer (d) has an acrylate content or a methacrylate content of 3-30% by weight. A resin composition according to any one of claims 1 to 14, wherein the α-olefin-alkyl (meth)acrylate copolymer (d) has a functional group selected from carboxylic acid groups, acid anhydride groups, acid amide groups, imide groups, hydroxyl group and epoxy groups.

Inventors: MARUYAMA TAKASHI, MIZUNO YUKIO, MARUYAMA, TAKASHI, MIZUNO, YUKIO
Applicants: SUMITOMO CHEMICAL CO, SUMITOMO CHEMICAL COMPANY, LIMITED
Application year: 1990
Main classification: C08L23
IPC codes: C08L71, C08L53, C08L23