United States Patent (19) 11) Patent Number: 5,073,590 Abe Et Al
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United States Patent (19) 11) Patent Number: 5,073,590 Abe et al. (45) Date of Patent: Dec. 17, 1991 54 THEMOPLASTICRESIN COMPOSITION 330015 8/1989 European Pat. Off. AND PROCESS FOR PRODUCING THE 60-188457 2/1986 Japan. SAME OTHER PUBLICATIONS (75. Inventors: Hiroomi Abe; Taichi Nishio, both of Chiba; Kiyoshi Mitsui, Ichihara; "Patent Abstracts of Japan, vol. 10, No. 36 (C-328) Satoru Sogabe, Chiba; Takashi (2093), Feb. 10, 1986. Sanada, Ichihara, all of Japan Primary Examiner-Ana L. Carrillo 73 Assignee: Sumitomo Chemical Company, Attorney, Agent, or Firm-Stevens, Davis, Miller & Limited, Osaka, Japan Mosher 21 Appl. No.: 698,337 57 ABSTRACT A thermoplastic resin composition is obtained by blend (22 Filed: May 7, 1991 ing 100 parts by weight of a resin blend consisting of 10 to 90% by weight of at least one polypropylene type Related U.S. Application Data resin (A) selected from the group consisting of modified 63 Continuation of Ser. No. 418,203, Oct. 6, 1989, aban polypropylenes and compounds composed of modified doned. polypropylenes and polypropylenes, and 90 to 10% by (30) Foreign Application Priority Data weight of a polyamide resin (B); 2 to 30 parts by weight of an epoxy group containing copolymer (C) and 2 to Oct. 15, 1988 (JP Japan ................................ 63-260297 100 parts by weight of an ethylene-ag-unsaturated car 51 Int. Cl. ......................... C08L 77/00; C08K 3/00 boxylic acid alkyl estermaleic anhydride terpolymer 52 U.S. Cl. .................................... 524/449; 524/451; (D). 525/66; 525/179 The composition can easily be processed into a molded 58) Field of Search .................. 525/66, 179; 524/451, product, a film, a sheet or the like by a conventional 524/449 processing method such as injection molding and extru (56) References Cited sion molding. The resulting product has a very good U.S. PATENT DOCUMENTS balance in physical properties such as heat resistance, 4,554,320 1 1/1985 Reimann et al. .................... 525/183 coating properties, impact strength and flexural modu 4,780,505 l0/1988 Mashita et al. ..................... 52.5/179 lus. The composition of this invention is useful in the fields of automobiles, electric industry and electronic FOREIGN PATENT DOCUMENTS industry. 180302 5/1986 European Pat. Off. 279578 8/1988 European Pat. Off. 10 Claims, No Drawings 5,073,590 - 1. 2 the product cannot be used in practice in automobile THEMOPLASTIC RESIN COMPOSITION AND parts, electric and electronic parts, etc. PROCESS FOR PRODUCING THE SAME (3) The mechanical properties, in particular, impact resistance, tensile elongation, etc., of a molded product This application is a Continuation of application Ser. 5 made of a mixture of a polypropylene resin and a poly No. 07/48,203, filed Oct. 6, 1989 now abandoned. amide resin often have values lower than those usually The present invention relates to a novel thermoplas expected from the additivity of the respective physical tic resin composition which can be utilized in the form properties of the polypropylene resin and the polyamide of molded articles, sheets, films, etc. through injection resin. molding. extrusion molding, etc. More particularly, it 10 (4) Polypropylenes are inherently poor in coating relates to a novel thermoplastic resin composition hav properties, adhesive properties and printability. There ing a good balance in physical properties, beautiful fore, although these properties are somewhat improved appearance and excellent coating properties, which is by blending a polyamide resin, those of the product obtained by blending a polypropylene resin and a poly obtained by mere mixing are not stable. amide resin with an epoxy group containing copolymer 15 An object of the present invention is to provide a and an ethylene-a, g-unsaturated carboxylic acid alkyl novel thermoplastic resin composition having excellent ester-maleic anhydride terpolymer. coating properties, a very good balance in physical Polypropylenes have heretofore been widely used in properties such as molding processability, stiffness, heat the form of molded articles, films, sheets, etc. because of resistance, impact resistance, scratch resistance, oil re their good molding processability, toughness, resis- 20 sistance, chemical resistance, water resistance, etc., and tances to water, gasoline, chemicals, etc., low specific a very uniform and smooth appearance. gravity and cost effectiveness. According to the present invention, there are pro They, however, are poor in heat resistance, stiffness, vided a thermoplastic resin composition comprising 100 impact resistance, coating properties, adhesive proper parts by weight of a resin blend consisting of 10 to 90% ties, printability, etc., which should be improved. This 25 by weight of at least one polypropylene type resin (A) defect is an obstacle to opening-up of new avenues of selected from the group consisting of modified polypro practical use for them. pylenes and compounds composed of modified polypro For improving the heat resistance, stiffness and in pylenes and polypropylenes, and 90 to 10% by weight pact strength, there have been developed composit of a polyamide resin (B); 2 to 30 parts by weight of an polypropylenes containing rubbers or reinforcing mate- 30 epoxy group containing copolymer (C); 2 to 100 parts rials. However, blending a reinforcing material for im by weight of an ethylene-ag-unsaturated carboxylic proving the heat resistance and stiffness greatly reduces acid alkyl ester-maleic anhydride (D); and optionally an the impact strength, and it does not raise the tempera inorganic filler (E); and a process for producing said ture that the resulting composite polypropylene resists thermoplastic resin composition. up to the melting point of the polypropylene contained 35 The polypropylene type resin (A) used in this inven therein. Although blending rubber improves the impact tion is a resin selected from the group consisting of resistance, it deteriorates the heat resistance and the modified polypropylenes and compounds composed of surface hardness. Thus, improving the balance in physi modified polypropylenes and polypropylenes. cal properties of composite polypropylenes has been In this invention, the polypropylene refers to a crys substantially impossible. 40 talline polypropylene and includes propylene homopol On the other hand, polyamide resins are widely used ymers and block or random copolymers obtained by in the fields of automobile parts and electric and elec copolymerizing propylene with at least one a-olefin tronic parts, as engineering resins having a characteristi such as ethylene or butene-1. cally high heat resistance, stiffness, strength, oil resis The homopolymers, block copolymers or random tance and the like, but it is desirable to further improve 45 copolymers can be obtained, for example, by reacting their molding processability, impact resistance, water the starting materials in the presence of a chemical resistance, chemical resistance, etc. In addition, they complex of a titanium trichloride and an alkylaluminum have inherent disadvantages in that they have a higher compound which is usually called Ziegler-Natta cata specific gravity and are more expensive than polyole lyst. fins. 50 In this invention, the modified polypropylene is ob From such a viewpoint, blending a polypropylene tained by modifying the homopolymer, the block co type resin selected from modified polypropylenes and polymer or the random copolymer by grafting thereon compounds composed of modified polypropylenes and an unsaturated carboxylic acid or a derivative thereof polypropylenes with a polyamide resin would give a or a combination of an unsaturated carboxylic acid or a thermoplastic resin having the characteristics of both 55 derivative thereof and an unsaturated aromatic mono the polypropylene resin and the polyamide resin whose mer in the presence of a free-radical initiator. various new uses can be expected. The graft modification in the presence of an unsatu However, it has heretofore been considered that the rated aromatic monomer yields a modified polypropyl compatibility and dispersability between polypropylene ene with small fluidity change (melt flow rate change) resins and polyamide resins are very poor. In fact, mere 60 before and after the graft modification. The modified mixing of the above two resins involves the following polypropylene thus obtained has a large amount of problems. unsaturated carboxylic acid or derivative thereof (1) Barus effect of molten polymer is remarkable, so grafted and excellent physical properties. that stable taking-off of extruded strand is substantially Specific examples of the unsaturated carboxylic acid impossible, resulting in a very low molding workability. 65 used for graft modification for obtaining the modified (2) There can be obtained only an injection-molded polypropylene in the present invention are acrylic acid, product which has an extreme nonuniformity and an methacrylic acid, maleic acid, itaconic acid, citraconic ugly appearance due to formation of flow marks. Thus, acid, bicyclo2,2,1 hepta-5-ene-2,3-dicarboxylic acid 5,073,590 3 4. (himic acid), bicyclo2,2,2-octa-5-ene2,3-dicarboxylic propylene into contact with oxygen or ozone in the acid, 4-methylcyclohexa-4-ene-1,2-dicarboxylic acid, presence of graft monomer(s). 1,2,3,4,5,8,9,10-octahydronaphthalene-2,3-dicarboxylic In consideration of economical benefit and the like, it acid, bicyclo2,2, locta-7-ene-2,3,5,6-tetracarboxylic is most preferable to employ the method comprising