A polyolefin resin composition comprising from 30% to 96% by weight of a polyolefin, from 3% to 50% by weight of a fibrous inorganic filler selected from the group consisting of a magnesium hydroxide fiber, a magnesium oxide fiber, and a gypsum fiber having a mean fiber diameter of from 0.1 to 2 .mu.m and an aspect ratio of from 20 to 100 or a mixture of two or more of said inorganic fillers, and from 1% to 60% by weight of a thermoplastic elastomer. The said composition provides a molded material which has a good external appearance and is excellent in the impact strength, rigidity, and heat stability.
The present invention is directed to a resin composition for electric insulation materials for vehicles such as distributor caps which is prepared by blending a crystalline propylene-ethylene copolymer resin with 3 to 10 wt. % of a glass fiber, 10 to 20 wt. % of talc or mica, 5 to 20 wt. % of silica, 4 to 20 wt. % of modified polyolefin resins, 10 to 30 wt. % of halogen-containing flame retardants and 3 to 15 wt. % of flame retardant auxiliaries. In the resin composition of the present invention, balance is kept in all points of mechanical characteristics, mechanical characteristics at high temperature, electrical characteristics, nitric acid resistance, weld characteristics, blooming resistance, corona resistance and flame retardance.
Provided are magnesium hydroxide particles having a hexagonal crystal form and having an aspect ratio (H) which satisfies the following expression (I), (wherein H is an aspect ratio, A is an average secondary particle diameter (.mu.m) of all of the particles measured by a laser diffraction scattering method and B is a specific surface area (m.sup.2 /g) of all of the particles measured by a BET method), a flame-retardant comprising the particles, a flame-retardant resin composition comprising 100 parts by weight of a synthetic resin and a 5 to 300 parts by weight of the magnesium hydroxide particles, and a molded article therefrom. The magnesium hydroxide particles are hexagonal single crystals, the hexagonal form thereof are not necessarily required to be regular hexagonal, and the size thereof are not necessarily constant. However, the aspect ratio thereof has a specific value in relation to the specific surface area and the average particle diameter, and the magnesium hydroxide particles have excellent properties as a flame retardant for synthetic resins.
A polypropylene resin composition comprising: (A) 50 to 90% by weight of a crystalline ethylene-propylene block copolymer; (B) 5 to 20% by weight of a hydrogenated block copolymer composed of both end blocks of an aromatic vinyl compound and an intermediate block of a conjugated diene polymer; (C) 0 to 15% by weight of an amorphous ethylene-propylene copolymer; (D) 0 to 5% by weight of a high density polyethylene having a melt flow index of 1 to 10; and (E) 5 to 30% by weight of a particulate or flaky inorganic filler having an average particle diameter of 3 .mu.m or less, wherein the blending ratio (B)/(C) (by weight) of the hydrogenated block copolymer component (B) to the amorphous ethylene-propylene copolymer component (C) is 100/0 to 20/80.
Disclosed is a coated resin molding comprising a molding composed of a resin composition comprising 100 parts by weight of a substrate resin comprising 100 to 30% by weight of at least one propylene polymer selected from the group consisting of propylene/ethylene block copolymers having an ethylene content of 3 to 45% by weight and propylene/ethylene random copolymers having an ethylene content of 0.5 to 10% by weight and 0 to 70% by weight of an elastomer, and at least one member selected from the group consisting of (A) 0.01 to 10 parts by weight of a 1,3-diene polymer having at least one terminal hydroxyl group or a hydrogenation product thereof, (B) 0.01 to 40 parts by weight of a copolymer of ethylene with an unsaturated compound containing a carboxyl group (including an acid anhydride group) and (C) 0.01 to 40 parts by weight of a copolymer of ethylene with an unsaturated compound containing a hydroxyl group, with the proviso that if at least two members of components (A), (B) and (C) are used in combination, the total amount does not exceed 40 parts by weight, and a coating formed directly on the surface of said molded body. One preferred application of this coated resin molding is an automotive part, especially a bumper.
Disclosed is a resin molding comprising a molding composed of a resin composition comprising 100 parts by weight of a substrate resin comprising 100 to 30% by weight of at least one propylene polymer selected from the group consisting of propylene/ethylene block copolymers having an ethylene content of 3 to 45% by weight and propylene/ethylene random copolymers having an ethylene content of 0.5 to 10% by weight and 0 to 70% by weight of an elastomer, and at least one member selected from the group consisting of (A) 0.01 to 10 parts by weight of a 1,3-diene polymer having at least one terminal hydroxyl group or a hydrogenation product thereof, (B) 0.01 to 40 parts by weight of a copolymer of ethylene with an unsaturated compound containing a carboxyl group (including an acid anhydride group) and (C) 0.01 to 40 parts by weight of a copolymer of ethylene with an unsaturated compound containing a hydroxyl group, with the proviso that if at least two members of components (A), (B) and (C) are used in combination, the total amount does not exceed 40 parts by weight, which preferably has a coating formed directly on the surface of said molded body. One preferred application of this coated resin molding is an automotive part, especially a bumper.
