Crystalline polypropylene resin composition and amide compounds

Abstract: Disclosed are a crystalline polypropylene resin composition comprising a crystalline polyproplylene resin and a β-nucleating agent, and a method of increasing the proportion of β-form crystals in a crystalline polypropylene resin molding comprising molding the composition, the β-nucleating agent being a diamide compound.

Description: The present invention relates to a crystalline polypropylene resin composition containing an amide compound capable of acting as a nucleating agent for predominant formation of the β-crystal form. Furthermore, the present invention relates to a method of increasing the proportion of β-form crystals in a crystalline polypropylene resin molded product, and to the use of a special amide compound as β-nucleating agent for a crystalline for a crystalline polypropylene resin. . It is known that crystalline polypropylene may occur in α, β, γ and δ crystal forms as well as in the smectic crystal form which is formed on quenching of melted polypropylene. The β-crystal form (hereinafter referred to as "β-form") differs from the α-form which is found in the conventional natural pellet in that it is lower in melting point and in density, not to speak of differences in the mode of crystallization and of fracture, thus being of interest from application points of view (Kobunshi Kagaku 30 , 694-698, (1973)). For the production of crystalline polypropylene containing the β-form, a process comprising crystallizing molten polypropylene on a temperature gradient and a process comprising blending with a small amount of a nucleating agent (hereinafter referred to as "β-nucleating agent") are known. Since the former process is time-consuming and provides only a low yield, the latter process employing a β-nucleating agent is more advantageous for all practical purposes. As such a β-nucleating agent, γ-guinacridone is well-known (Polymer Letters, 6 , 539-546, (1968)). However, this nucleating agent has the drawback that it imparts a red tint to the product and requires special apparatus and operation for blending it with the polymer. EP-A-0 263 678 discloses a polyphenylene ether composition comprising (a) a polyolefin resin, (b) a polyphenylene ether resin, and (c) a hydrogenated block copolymer of an alkenyl aromatic compound and a conjugated diene which contains more than 45% by weight and up to 80% by weight of a repeating unit derived from the alkenyl aromatic compound. In addition, DE-A-3 206 138 relates to readily crystallizing polyolefin molding compositions comprising 1) a crystallizable polyolefin, 2) a nucleating agent and 3), optionally, conventional other assistants and additives, characterised in that the compositions contain, as nucleating agent 2), anilides of organic carboxylic acids. The object of the present invention is to describle a β-nucleating agent insuring an efficient production of a product containing β-crystalline polypropylene in a large amount and much improved in the aspect of product color because of substantial absence of coloring property, and to provide a practically useful crystalline polypropylene resin composition containing said β-nucleating agent. This object has been achieved by amide compounds having a specific chemical structure. The crystalline polypropylene resin composition of the present invention is obtainable by molding a resin composition consisting essentially of a crystalline polypropylene resin, a β-nucleating agent, and optionally an additive selected from the group consisting of a stabilizer, an antioxidant, an ultraviolet absorber, a neutralizer, a nucleating agent, an antistatic agent, an antiblocking agent, a lubricant, a colorant, an elastomer, and a mineral, said β-nucleating agent being at least one selected from an amide compound of the formula wherein R 1 represents a saturated aliphatic C 4 - or C 6 -residue. The present invention also provides a method for increasing the proportion of the β-crystal form in a crystalline polypropylene resin molded product which comprises molding the composition consisting essentially of a crystalline polypropylene resin, at least one amide compound of the above formula (1) in an amount effective for increasing the proportion of the β-crystal form, and optionally an additive selected from the group consisting of a stabilizer, an antioxidant, an ultraviolet absorber, a neutralizer, a nucleating agent, an antistatic agent, an antiblocking agent, a lubricant, a colorant, an elastomer, and a mineral. Moreover, the present application discloses the use of at least one amide compound selected from amide compounds of the formula (1) as defined above as β-nucleating agent for a crystalline polypropylene resin to achieve a β-form crystal content of 40 to 97% calculated by means of equation (I): β-form crystal content (%) = 100 x A β /(A α +A β ) where A α means the peak area of α-form and A β means the peak area of β-form determined by differential scanning calorimetry. Further embodiments of the present application are described in the dependent claims. Processes for the production of amide compounds of the formula (1) are described below. Amide compounds of the formula (1) The amide compound of the formula (1) can be easily prepared by subjecting a saturated aliphatic dicarboxylic acid of the the formula HOOC-R 1 -COOH wherein R 1 is as defined hereinbefore to amidation reaction with an aromatic monoamine of the formula This amidation reaction can be carried out in a conventional manner and any one of the following processes may be mentioned as typical examples. (i) In an inert solvent, said dicarboxylic acid is reacted with said monoamine at a temperature of 60 to 200°C for 2 to 8 hours. The monoamine is generally used in an amount of 2 to 10 equivalents per one equivalent of the dicarboxylic acid. In this process, an activator is preferably used to accelerate the reaction. The activator that can be used includes phosphorus pentaoxide, polyphosphoric acid, phosphorus pentaoxide-methanesulfonic acid, phosphorous ester (e.g. triphenyl phosphite)-pyridine, phosphorous ester-metal salt (e.g. lithium chloride) or triphenylphosphine-hexachloroethane. Generally, about one mole of the activator is used per mole of the dicarboxylic acid. (ii) In an inert solvent, dichloride of said dicarboxylic acid is reacted with said monoamine at a temperature of 0 to 100°C for 1 to 5 hours. The monoamine is used generally in an amount of 2 to 3 equivalents per one equivalent of the dicarboxylic acid dichloride. (iii) In an inert solvent, a diester, particularly a di(C 1-3 )alkyl ester, of said dicarboxylic acid is reacted with said monoamine in the presence of a catalyst at 0-150°C for 3 to 10 hours. The monoamine is used generally in an amount of 2 to 20 equivalents per one equivalent of the dicarboxylic acid diester. The catalyst may be an acid or basic catalyst that is conventionally used in ester-amide interchange reactions, and is preferably a basic catalyst. Thus, there may be mentioned lithium, sodium, potassium; alkali metal hydrides such as lithium hydride, sodium hydride or potassium hydride; alkali metal hydroxides such as lithium hydroxide, sodium hydroxide or potassium hydroxide; metal alkoxides such as sodium methoxide, sodium ethoxide or potassium tert-butoxide; and alkali metal amides such as sodium amide or lithium dipropylamide; among others. The catalyst is used generally in an equimolar amount relative to said dicarboxylic acid. The inert solvent which can be used for the above processes (i), (ii) and (iii) include, among others, benzene, toluene, xylene, chloroform, chlorobenzene, dichlorobenzene, tetrahydrofuran, dioxane, acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone. As the dicarboxylic acid of the formula (1a) for use in said processes (i), (ii) and (iii), there may be mentioned the saturated aliphatic dicarboxylic acid corresponding to R 1 . Thus, R 1 is preferably a residue formed by elimination of the two carboxyl groups of one of the following saturated aliphatic, alicylic and aromatic dicarboxylic acids. The aliphatic dicarboxylic acid specifically includes adipic acid, or suberic acid. On the other hand, the monoamine to be used in processes (i), (ii) and (iii) is the aromatic monoamine aniline. The compounds obtained by the above processes (i), (ii) and (iii) can each be isolated and purified by the conventional procedures such as chromatography, reprecipitation, recrystallization, fractional crystallization, and so on. The β-nucleating agent of the formula (1) can be added to polypropylene resin at an optional stage, i.e. either during the polymerization reaction or after the polymer has been prepared. The amount of said β-nucleating agent to be added is not critical insofar as the desired effect can be obtained. Generally, it is used in an amount effective for increasing the content of the β-crystal form. Especially, based on 100 parts by weight of polypropylene resin, 0.0001 to 5 parts by weight, preferably 0.001 to 1 part by weight, of the β-nucleating agent is employed. If the proportion of the β-nucleating agent is less than 0.0001 part by weight, formation of the β-crystal form may not be sufficient, while the use of the β-nucleating agent in excess of 5 parts by weight may not be rewarded with a commensurate effect and be uneconomical. Thus, the β-nucleating agent of the invention is capable of causing a crystalline polypropylene resin to undergo transition to the β-crystal form at a very low level of addition and a molded product having a β-form content of 20 to 97%, particularly 40 to 97 %, more preferably 50 to 90 % can be obtained under the conventional molding conditions. The term 'polypropylene resin' as used in this specification and claim means not only a polypropylene homopolymer but also a polymer composed predominantly of propylene, particularly a polymer composed of not less than 50% by weight, preferably not less than 80% by weight, of propylene. As examples of the latter polymer, there may be mentioned propylene-ethylene random copolymer, propylene-ethylene block copolymer, polymer blends of said polypropylene resin with a small proportion of a thermoplastic resin, such as high-density polyethylene, polybutene-1 or poly-4-methylpentene-1. The catalyst which can be used for the production of such polymers includes not only a Ziegler-Natta catalyst which is commonly employed but also a combination catalyst, such as one wherein a transition metal compound (e.g. titanium halides such as titanium trichloride, titanium tetrachloride, etc.) supported on a support composed mainly of magnesium halide, such as magnesium chloride, is combined with an alkylaluminum compound (e.g. triethylaluminum, diethylaluminum chloride, etc.). The melt flow rate (hereinafter referred to briefly as "MFR"; measured in accordance with JIS K 6758-1981) of the crystalline polypropylene resin can be appropriately selected according to the molding method to be employed and is generally 0.1 to 100 g/10 min. and preferably 0.5 to 50 g/10 min. If required, the resin composition of the present invention may contain a variety of additives such as a stabilizer (e.g. epoxy compounds), an antioxidant (e.g. phenol compounds, phosphite compounds), an ultraviolet absorber (benzophenone compounds, benzotriazole compounds), a neutralizer, a nucleatig agent, an antistatic agent, an antiblocking agent, a lubricant (e.g. aliphatic hydrocarbons, higher fatty acids, and the alkali metal salts or alkaline earth metal salts thereof, fatty acid esters, higher fatty acid amides, rosin derivatives), a colorant, an elastomer, and a mineral (e.g. talc, hydrotalcite), each within a range not interfering with the effect of the invention. The crystalline polypropylene resin composition of the invention is preferably produced by mixing said β-nucleating agent and polypropylene resin, with or without addition of said additives, in an ordinary mixer, such as a Henschel mixer, and if necessary, pelletizing the resulting mixture using an ordinary pelletizer, such as a single-screw extruder, in the per se known manner. The resulting crystalline polypropylene resin composition of the invention can be molded by various known techniques. Thus, injection molding, extrusion molding, compression molding and other molding techniques utilizing the conventional molding machines can be employed. Molding conditions may be those commonly employed. Typical preferred molding conditions may be as follows. Injection molding: resin temperature 200 to 300°C, preferably 240 to 280°C; mold temperature 30 to 120°C, preferably 50 to 80°C. Extrusion molding: resin temperature 200 to 300°C, preferably 240 to 280°C ; chill roll temperature 40 to 140°C, preferably 60 to 120°C. Compression molding: temperature of melted resin about 200 to 300°C, preferably 240 to 280°C; cooling temperature 30 to 120°C, preferably 50 to 100°C. Molded product, which contains much higher proportion of β-crystal form than before and which is satisfactory in the aspect of color, can be easily obtained by molding under the above-mentioned molding condition the resin composition of the invention prepared with use of the above-mentioned mixing method. Compared with the conventional polypropylene pellet which does not substantially contain β-crystals but is predominantly composed of α-crystals, the polypropylene molded product has lower melting point and requires a less force for deformation under heating. Therefore, the molded products contributes a great deal to improved secondary processability and mechanical characteristics. The products encompass a wide variety of forms such as packages, sheets or films. With the resin composition of the present invention, the ratio of α- to β-forms in the final product can be controlled as desired by suitably selecting molding conditions such as cooling conditions. For example, the proportion of β-form is increased as a higher cooling temperature is employed. Thus, it is possible to control the ratio of α- to β-forms by appropriately selecting cooling condition under the above molding condition. This characteristic is beneficial particularly in the surface roughening of biaxially oriented film. The film having such a roughened surface displays excellent antiblocking property, printability and adhesion, etc. and is of great use in the fields of packaging film, printing paper, tracing paper, oil-immersion type plastic capacitors and so on. Examples The following examples and comparative examples are intended to describe the invention in further detail. In these examples and comparative examples, the β-form content, modulus in flexure and impact strength were determined by the following methods. (1) Determination of β-form content A sample (5-10 mg), cut from the sheet obtained in each Example and Comparative Example by punching, is set in the sample holder of a differential scanning calorimeter (DSC) and melted by heating in a nitrogen gas atmosphere at 230°C for 5 minutes. The temperature is then decreased at a rate of 20°C/min to near room temperature and, then, increased again at a rate of 20°C/min. From the peak areas of the α- and β-crystal forms on the DSC thermogram thus obtained, the β-form content (area %) is calculated by means of the following equation. β-form content (%) = 100 x A β /(A α + A β ) where A α means the peak area of α-form and A β means the peak area of β-form. (2) Determination of modulus in flexure The modulus was determined in accordance with JIS K 7203. The testing temperature was 25°C and the testing speed was 10 mm/min. (3) Impact strength (duPont method) In accordance with the falling weight impact test method described in JIS K 7211, the 50% destruction energy for a 2mm-thick sheet at 23°C was determined. Example 1 (Reference example) To 100 parts by weight of a propylene homopolymer powder (MFR = 14 g/10 min) was added 0.05 part by weight of N,N'-dicyclohexylterephthalamide and the mixture was milled in a Henschel mixer and pelletized with a 20 mm-diameter single-screw extruder. The resulting pellets were subjected to compression-molding by melting the pellets at 230°C for 10 minutes and then placing it in a mold of 60°C and maintaining it therein for 5 minutes for solidification to give a 0.5 mm-thick sheet. The β-form content of the resulting sheet was 93% and the sheet showed no coloration. Example 2 (Reference example) Except that N,N'-dicyclohexyl-1,4-cyclohexanedicarboxamide was used as the β-nucleating agent, the procedure of Example 1 was otherwise repeated to provide a sheet. The β-form content of this sheet was 42% and the sheet showed no coloration. Example 3 (Reference example) Except that N,N'-dicylohexyl-2,6-naphthalenedicarboxamide was used as the β-nucleating agent, the procedure of Example 1 was repeated to provide a sheet. The β-form content of this sheet was 97% and the sheet showed no coloration. Example 4 (Reference example) Except that N,N'-dicylohexyl-4,4'-biphenyldicarboxamide was used as the β-nucleating agent, the procedure of Example 1 was repeated to provide a sheet. The β-form content of this sheet was 59% and the sheet showed no coloration. Example 5 (Reference example) Except that N,N'-bis(p-methylphenyl)hexanediamide was used as the β-nucleating agent, the procedure of Example 1 was repeated to provide a sheet. The β-form content of this sheet was 89% and the sheet showed no coloration. Example 6 (Reference example) Except that N,N'-bis(p-ethylphenyl)hexanediamide was used as the β-nucleating agent, the procedure of Example 1 was repeated to provide a sheet. The β-form content of this sheet was 64% and the sheet showed no coloration. Example 7 (Reference example) Except that N,N'-bis(4-cyclohexylphenyl)hexanediamide was used as the β-nucleating agent, the procedure of Example 1 was repeated to provide a sheet. The β-form content of this sheet was 82% and the sheet showed no coloration. Example 8 (Reference example) Except that 0.05 part by weight of N,N'-1,4-phenylenebis-cyclohexanecarboxamide was used as the β-nucleating agent, the procedure of Example 1 was repeated to provide a sheet. The β-form content of this sheet was 84% and the sheet showed no coloration. Example 9 (Reference example) Except that N,N'-1,5-naphthalenebis-benzamide was used as the β-nucleating agent, the procedure of Example 1 was repeated to provide a sheet. The β-form content of this sheet was 44% and the sheet showed no coloration. Example 10 (Reference example) Except that N,N'-1,4-cyclohexanebis-benzamide was used as the β-nucleating agent, the procedure of Example 1 was repeated to.provide a sheet. The β-form content of this sheet was 92% and the sheet showed no coloration. Example 11 (Reference example) Except that N,N'-1,4-cyclohexanebiscyclohexanecarboxamide was used as the β-nucleating agent, the procedure of Example 1 was repeated to provide a sheet. The β-form content of this sheet was 85% and the sheet showed no coloration. Example 12 (Reference example) Except that N-cyclohexyl-4-(N-cyclohexylcarbonylamino)benzamide was used as the β-nucleating agent, the procedure of Example 1 was repeated to provide a sheet. The β-form content of this sheet was 42% and the sheet showed no coloration. Example 13 (Reference example) Except that N-phenyl-5-(N-benzoylamino)-pentanamide was used as the β-nucleating agent, the procedure of Example 1 was repeated to provide a sheet. The β-form content of this sheet was 38% and the sheet showed no coloration. Example 14 (Reference example) Except that polypropylene homopolymer (MFR = 4.3 g/10 min) was used as the polypropylene, the procedure of Example 1 was repeated to provide a sheet. The β-form content of this sheet was 95% and the sheet showed no coloration. Comparative Example 1 Except that N,N'-dicyclohexylterephthalamide was not added, the procedure of Example 1 was repeated to provide a sheet and its β-form content was determined. This sheet contained only a trace amount of β-form. The sheet showed no coloration. Comparative Example 2 Except that γ-quinacridone was used as the β-nucleating agent, the procedure of Example 1 was repeated to provide a sheet. However, under the particular conditions used, the sheet contained only a trace amount of β-form. The sheet had a red color. Example 15 (Reference example) To 100 parts by weight of a propylene homopolymer powder (MFR = 14 g/10 min) was added 0.2 part by weight of N,N'-dicyclohexyl-2,6-naphthalene-dicarboxamide and the mixture was milled in a Henschel mixer and pelletized with a 20 mm-diameter single-screw extruder. The resulting pellets were injection-molded at a resin temperature of 240°C and a mold temperature of 50°C to provide a test piece. The modulus in flexure of the above test piece was 1481 N/mm 2 (151 kgf/mm 2 ). The duPont impact strength was 402 N·cm (41 kgf·cm). Comparative Example 3 Except that N,N'-dicyclohexyl-2,6-naphthalenedicarboxamide was not added, the procedure of Example 15 was otherwise repeated to provide a sheet. This sheet had a modulus in flexure of 1364 N/mm 2 (139 kgf/mm 2 ) and a duPont impact strength of 29 N·cm (3 kgf·cm). Example 16 (Reference example) A 300 ml four-necked flask equipped with a stirrer, thermometer, condenser and gas inlet was charged with 6.48 g (0.03 mole) of 2,6-naphthalenedicarboxylic acid, 5.61 g (0.066 mole) of cyclopentylamine, 20.46 g (0.066 mol) of triphenyl phosphite, 25 g of pyridine and 100 g of N-methylpyrrolidone, and the reaction was carried out in a nitrogen gas atmosphere at 100°C for 3 hours, with stirring. After cooling, the reaction mixture was poured in 700 ml of isopropyl alcohol/water (1:1) for reprecipitation and washing. The mixture was stirred for 2 hours and the precipitate was then recovered by filtration and dried under reduced pressure at 110°C to provide 9.03 g (yield 86%) of N,N'-dicyclopentyl-2,6-naphthalenedicarboxamide. This compound was a white powder melting at 375.4°C (decomp.). The elemental analysis and characteristic infrared absorptions are shown in Table 1. Example 17 (Reference example) Except that 6.53 g (0.066 mole) of cyclohexylamine was used as the monoamine, the procedure of Example 16 was otherwise repeated to provide 9.64 g (yield 85%) of N,N'-dicyclohexyl-2,6-naphthalene-dicarboxamide. This compound was a white powder melting at 384.2°C (decomp.). The elemental analysis and characteristic infrared absorptions are shown in Table 1. Except that the above compound was used as the β-nucleating agent, the procedure of Example 1 was otherwise repeated to provide a sheet. The β-form content of this sheet was 97% and the sheet showed no coloration. Example 18 (Reference example) Except that 8.38 g (0.066 mole) of cyclooctylamine was used as the monoamine, the procedure of Example 16 was otherwise repeated to provide 9.63 g (yield 74%) of N,N'-dicyclooctyl-2,6-naphthalenedicarboxamide. This compound was a white powder melting at 320.8°C (decomp.). The elemental analysis and characteristic infrared absorptions are shown in Table 1. Example 19 (Reference example) Except that 12.08 g (0.066 mole) of cyclododecylamine was used as the monoamine, the procedure of Example 16 was repeated to provide 13.3 g (yield 81%) of N,N'-dicyclododecyl-2,6-naphthalenedicarboxamide. This compound was a white powder melting at 321.8°C (decomp.). The elemental analysis and characteristic infrared absorptions are shown in Table 1. Example 20 (Reference example) Except that 6.48 g (0.03 mole) of 2,7-naphthalenedicarobxylic acid was used as the dicarboxylic acid, the procedure of Example 17 was otherwise repeated to provide 8.39 g (yield 74%) of N,N'-dicyclohexyl-2,7-naphthalenedicarboxamide. This compound was a white powder melting at 337.1°C (decomp.). The elemental analysis and characteristic infrared absorptions are shown in Table 1. Example 21 (Reference example) Except that 7.26 g (0.03 mole) of 4,4'-biphenyldicarboxylic acid was used as the dicarboxylic acid, the procedure of Example 16 was otherwise repeated to provide 8.12 g (yield 72%) of N,N'-dicyclopentyl-4,4'-biphenyldicarboxamide. This compound was a white powder melting at 355.0°C (decomp.). The elemental analysis and characteristic infrared absorptions are shown in Table 1. Example 22 (Reference example) Except that 6.53 g (0.066 mole) of cyclohexylamine was used as the monoamine, the procedure of Example 21 was otherwise repeated to provide 9.94 g (yield 82%) of N,N'-dicyclohexyl-4,4'-biphenyldicarboxamide. This compound was a white powder melting at 370.8°C (decomp.). The elemental analysis and characteristic infrared absorptions are shown in Table 1. Except that the above compound was used as the β-nucleating agent, the procedure of Example 1 was otherwise repeated to provide a sheet. The β-form content of this sheet was 59% and the sheet showed no coloration. Example 23 (Reference example) Except that 8.38 g (0.066 mole) of cyclooctylamine was used as the monoamine, the procedure of Example 21 was otherwise repeated to provide 10.8 g (yield 78%) of N,N'-dicyclooctyl-4,4'-biphenyldicarboxamide. This compound was a white powder melting at 320.2°C (decomp.). The elemental analysis and characteristic infrared absorptions are shown in Table 1. Example 24 (Reference example) Except that 12.08 g (0.066 mole) of cyclododecylamine was used as the monoamine, the procedure of Example 21 was otherwise repeated to provide 17.16 g (yield 82%) of N,N'-dicyclododecyl-4,4'-biphenyldicarboxamide. This compound was a white powder melting at 346.7°C (decomp.). The elemental analysis and characteristic infrared absorptions are shown in Table 1. Example 25 (Reference example) A reactor was charged with 8.37 g (0.03 mole) of 2,2'-biphenyldicarboxylic acid dichloride, 11.88 g (0.12 mole) of cyclohexylamine and 120 g of chlorobenzene and the reaction was carried out in a nitrogen gas atmosphere at 80°C for 2.5 hours. After cooling, the reaction mixture was poured in 1000 ml of hexane for reprecipitation and washing. The precipitate was washed with 600 ml of a 0.5% aqueous sodium hydroxide solution and further with purified water thoroughly. The precipitate was collected by filtration and dried under reduced pressure at 110°C to provide 6.08 g (yield 50%) of N,N'-dicycohexyl-2,2'-biphenyldicarboxamide. This compound was a white powder melting at 229.2-229.8°C. The elemental analysis and characteristic infrared absorptions are shown in Table 1. Example Elemental Analysis (%) Infrared spectra (cm -1 ) Calcd. Found 1 6 C:75.40 C:75.28 1330, 1553, 1628, 3264(amido) H: 7.48 H: 7.61 1450, 2869, 2960(cyclopentyl ) N: 7.99 N: 7.84 697, 774, 838, 1595, 3074(2,6-naphthalene) 1 7 C:76.16 C:76.04 1320, 1537, 1631, 3306(amido) H: 7.99 H: 8.12 1450, 2853, 2937(cyclohexyl) N: 7.40 N: 7.28 697, 778, 820, 1605, 3063(2,6-naphthalene) 1 8 C:77.38 C:77.29 1315, 1529, 1632, 3317( amido ) H: 8.81 H: 8. 88 1448, 2860, 2924(cyclooctyl) N: 6.45 N: 6.37 697, 775, 819, 1605, 3062(2,6-naphthalene) 1 9 C:79.07 C:78.89 1327, 1536, 1634, 3317( amido ) H: 9.95 H:10.16 1469, 2862, 2944(cyclododecyl) N: 5.12 N: 4.96 698, 768, 825, 1598, 3064(2,6-naphthalene) 2 0 C:76.16 C:76.02 1338, 1565, 1640, 3241( amido ) H: 7.99 H: 8. 10 1454, 2852, 2929(cyclohexyl) N: 7.40 N: 7.28 729, 822, 855, 1620, 3068(2,7-naphthalene) 2 1 C:76.56 C:76.38 1324, 1532, 1630, 3307( amido ) H: 7.50 H: 7.70 1451. 2869. 2957(cyclopentyl) N: 7.44 N: 7.32 760, 843, 1492(4,4'- biphenyl) 2 2 C:77.19 C:77.03 1328, 1529, 1632, 3319( amido ) H: 7.97 H: 8.13 1449, 2854, 2936(cyclohexyl) N: 6.92 N: 6.77 759, 843, 1491(4,4'-biphenyl) 2 3 C:78.22 C:78.10 1327, 1532, 1626, 3314( amido ) H: 8.75 H: 8.91 2847, 2926(cyclooctyl) N: 6.08 N: 5.92 758, 840, 1493(4,4'-biphenyl) 2 4 C:79.67 C:79.41 1329, 1538, 1636, 3324( amido ) H: 9.85 H:10.00 1444, 2863, 2947(cyclododecyl) N: 4.89 N: 4.69 757, 841, 1492(4,4'-biphenyl) 2 5 C:77.19 C:77.08 1339, 1558, 1635, 3241( amido ) H: 7.97 H: 8.06 1450, 2854, 2931(cyclohexyl) N: 6.92 N: 6.84 758, 1471(2,2'-biphenyl) Table 2 below shows the structure each of the β-nucleating agents used in Examples 1-25. Examples 26 and 27 Except that N,N'-diphenylhexanediamide (Example 26) or N,N'-diphenyloctanediamide (Example 27) was used as the β-nucleating agent, the procedure of Example 1 was repeated to provide a sheet. The β-form contents of the resulting sheets are shown in Table 3 below. Comparative Examples 3-8 Except that each of the amide compounds listed in Table 3 below (i.e., N,N'-diphenyl-butanediamide; N,N'-diphenyl-pentanediamide, N,N'-diphenyl-heptanediamide, N,N'-diphenyl-nonanediamide, N,N'-diphenyl-decanediamide and N,N'-diphenyl-terephthalamide) was used as the β-nucleating agent, the procedure of Example 1 was repeated to provide a sheet. The β-form contents of the resulting sheets are shown in Table 3 below.

Claims: A molded crystalline polypropylene resin composition obtainable by molding a resin composition consisting essentially of a crystalline polypropylene resin, a β-nucleating agent, and optionally an additive selected from the group consisting of a stabilizer, an antioxidant, an ultraviolet absorber, a neutralizer, a nucleating agent, an antistatic agent, an antiblocking agent, a lubricant, a colorant, an elastomer, and a mineral, said β-nucleating agent being at least one selected from an amide compound of the formula wherein R 1 represents a saturated aliphatic C 4 - or C 6 - residue. The molded composition according to claim 1, which is obtainable by injection-molding said resin composition comprising said crystalline polypropylene resin and said at least one β-nucleating agent at a resin temperature of 200 to 300 °C and a mold temperature of 30 to 120 °C. The molded composition according to claim 1, which is obtainable by extrusion-molding said resin composition comprising said crystalline polypropylene resin and said at least one β-nucleating agent at a resin temperature of 200 to 300 °C and a chill roll temperature of 40 to 140 °C. The molded composition according to claim 1, which is obtainable by compression-molding said resin composition comprising said crystalline polypropylene resin and said at least one β-nucleating agent at a resin temperature of 200 to 300 °C and a cooling temperature of 30 to 120 °C. A method of increasing the proportion of β-form crystals in a crystalline polypropylene resin molded product which comprises molding a crystalline polypropylene resin composition consisting essentially of a crystalline polypropylene resin, at least one β-nucleating agent selected from amide compounds of the formula (1) of claim 1, and optionally an additive selected from the group consisting of a stabilizer, an antioxidant, an ultraviolet absorber, a neutralizer, a nucleating agent, an antistatic agent, an antiblocking agent, a lubricant, a colorant, an elastomer, and a mineral. The method according to claim 5, wherein said resin composition is injection-molded at a resin temperature of 200 to 300 °C and a mold temperature of 30 to 120 °C. The method according to claim 5, wherein said resin composition is extrusion-molded at a resin temperature of 200 to 300 °C and a chill roll temperature of 40 to 140 °C. The method according to claim 5, wherein said resin composition is compression-molded at a resin temperature of 200 to 300 °C and a cooling temperature of 30 to 120 °C. Use of at least one amide compound selected from amide compounds of the formula (1) of claim 1 as β-nucleating agent for a crystalline polypropylene resin to achieve a β-form crystal content of 40 to 97% calculated by means of equation (I) β-form crystal content (%) = 100 x A β /(A α +A β ) where A α means the peak area of α-form and A β means the peak area of β-form determined by differential scanning calorimetry.

Inventors: KAWAHARA YASUYUKI, KAWASHIMA YUJI, KITAGAWA HIROSHI, MIZOGUCHI KAZUAKI, NAOKI IKEDA, SADAMITSU KIYOSHI, YOSHIMURA MASAFUMI, KAWAHARA, YASUYUKI, KAWASHIMA, YUJI, KITAGAWA, HIROSHI, MIZOGUCHI, KAZUAKI, NAOKI, IKEDA, SADAMITSU, KIYOSHI, YOSHIMURA, MASAFUMI
Applicants: NEW JAPAN CHEM CO LTD, NEW JAPAN CHEMICAL CO.,LTD.
Application year: 1993
Main classification: C08K5
IPC codes: C08K5