Ube Industries, Inc.

Toyota Jidosha Kabushiki Kaisha

Nippon Steel Corporation

Toyota Jidosha Kabushiki Kaisha & Ube Industries, Ltd.

Saburo Hinenoya

Tomohiko Akagawa

Takeyoshi Nishio

Takao Nomura

Ikunori Sakai

Kouhei Ueno

Kaoru Inoue

Yoshihiro Inuizawa

Norihisa Tamashima

Shinji Katsui

Yoshio Shindou

Osamu Fukui

Yasuo Kita

Mansei Tanaka

Yasufumi Takasaki

Kohhei Ueno

Masami Ishida

Fuyuhiko Ohtsuki

Kazuyuki Suzuki

Toshio Morimoto

A polypropylene resin composition having excellent rigidity, impact resistance and formability (moldability) and thus useful for the interior parts of automobile, includes (A) a crystalline E/P block copolymer containing a fraction Ac soluble in p-xylene at room temperature and having an ethylene content of 18 to 22%; (B) a crystalline E/P block copolymer containing a fraction Bc soluble in p-xylene at room temperature and having an ethylene content of 27 to 40% and (C) talc particles having an average size of 3 to 5 .mu.m and largest size less than 20 .mu.m, in which composition, (a) the p-xylene-soluble fractions Ac and Bc are in contents As and Bs based on the total weight of the copolymers (A) and (B) and satisfying As+Bs=7 to 17% by weight and As/(A +Bs)=0.1 to 0.6; (b) an isotactic pentad fraction of propylene in each of copolymers (A) and (B) is 96% or more, and the mixture of the copolymers (A) and (B) has a MFR of 20 to 35 g/10 min at 230.degree. C. under 2160 g load; and (c) the copolymers (A) and (B) are in a total weight content of 50 to 95% and talc (C) is in a weight content of 5 to 50%.

Polypropylene resin composition

A polypropylene resin composition comprising the following components (A), (B), (C) and (D): (A) a crystalline ethylene-propylene block copolymer containing a room-temperature-p-xylene-soluble fraction Ac having an ethylene content of 12-26% by weight and an intrinsic viscosity (measured at 135.degree. C. in decalin) of 6 dl/g or more, (B) a crystalline ethylene-propylene block copolymer containing a room-temperature-p-xylene-soluble fraction Bc having an ethylene content of 27-50% by weight and an intrinsic viscosity (measured at 135.degree. C. in decalin) of 4 dl/g or less, (C) an ethylene-.alpha.-olefin copolymer obtained by polymerization using a single-site catalyst, having a molecular weight distribution (Mw/Mn) of 2.5 or less, a melt flow ratio (MI.sub.10 /MI.sub.2.16) of 6-15 (wherein MI.sub.10 is a melt index measured at 190.degree. C. under a load of 10 kg and MI.sub.2.16 is a melt index measured at 190.degree. C. under a load of 2.16 kg) and an .alpha.-olefin proportion of 70 mole % or less, and (D) a talc having an average particle diameter of 3-7 .mu.m as measured by laser diffraction. In the composition the weight ratios As and Bs of the room-temperature-p-xylene-soluble fractions Ac and Bc to the total weight of the components (A) and (B) satisfy the following formulas (1) and (2):

Polyproplylene resin composition

The polypropylene resin composition of the present invention comprises specific proportions of a crystalline ethylene-propylene block copolymer, an hydrogenated block copolymer, an amorphous ethylene-propylene copolymer, surface-treated talc, fibrous magnesium oxysulfate of granular form and a metal soap. This resin composition is well balanced in rigidity and impact resistance, has good mar resistance, and can be preferably used in large-sized parts for automobiles, particularly instrument panels for automobiles.

A polypropylene resin composition comprising:

A polypropylene resin composition obtained by mixing a crystalline ethylene-propylene block copolymer, an amorphous ethylene-propylene copolymer, talc and fibrous magnesium oxysulfate and then, at the time of melt-kneading the mixture, adding a metal soap to the mixture, retains the fiber length of the fibrous magnesium oxysulfate and has high rigidity with the addition of a small amount of the metal soap.

A polypropylene coated steel pipe comprising a steel pipe, an adhesive layer coated on the external surface of the steel pipe, which has been subjected to a pretreatment, and a polypropylene layer coated on the adhesive layer. The outermost polypropylene layer comprises, as a main constituent, a crystalline ethylene-propylene block copolymer and the adhesive layer comprises a modified polyolefin adhesive.

Polypropylene coated steel pipe

A modified polyolefin composition useful for producing a shaped article having an excellent bonding property and an enhanced impact resistance comprises a modified olefin polymer material prepared by melting a mixture of an olefin polymer material comprising at least one crystalline ethylene-propylene random copolymer containing from 0.5 to 5% by weight of copolymerized ethylene and having a melt flow index of from 0.2 to 5 with a modifying agent consisting of at least one unsaturated dicarboxylic anhydride and a radical reaction initiator at a temperature of from 170.degree. C. to 270.degree. C. at which the mixture is melted; and a polyolefin rubber having a Mooney viscosity ML.sub.1+4 (100.degree. C.) of 10 to 100 and mixed in an amount of from 5% to 40% based on the sum of the weight of the modified olefin polymer material and the polyolefin rubber with the modified olefin polymer material at a temperature at which the mixture is melted.

Modified polyolefin composition and process for producing the same

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Sakai, Japan

Saburo Hinenoya