Nissan Motor Company Limited

Nippon Petrochemicals Company, Limited

Nippon Oil Fats Co., Ltd.

Nihon Tokushu Toryo Co., Ltd.

Masashi Ohno

Kiminori Ishii

Takashi Toyama

Masahiko Yamanaka

Yukio Okada

Shosaku Yamamoto

Kazuo Kakinuma

Takashi Sugimoto

Tadahiko Morigaki

Hiroyoshi Ohmika

Shouji Aramaki

Haruhiro Itoh

Yujiro Kawamura

Tutomu Hattori

Toyo Kawase

An aqueous primer composition for use in applying to polyolefin resin substrates which is excellent in adhesiveness to polyolefin resin substrates, water resistance and gasoline resistance and which is free from the problems of fire and environments pollution. The primer composition comprises a resin component (a) of 100 parts by weight of modified polyolefin which is prepared by modifying polyolefin with an .alpha., .beta.-unsaturated carboxylic acids and which contains 0.05 to 0.5 equivalent of free carboxylic acid groups per 100 g, with the other resin component (b) of 5 to 500 parts by weight of modified resin having both ethylenically unsaturated double bonds and free carboxylic acid groups, which modified resin is prepared by adding an .alpha., .beta.-unsaturated dicarboxylic anhydride to a drying oil or a conjugated diene polymer or conjugated diene copolymer and then opening the ring of the acid anhydride group; and is prepared by neutralizing at least a part of free carboxylic acid groups of said modified polyolefin of component (a) and/or said modified resin of component (b) with a base and then dissolving or dispersing them in water.

Aqueous primer composition for polyolefin resins

A rust preventive coating composition to be applied to the underfloor of an automotive vehicle for the purpose of preventing the underfloor from being rusted. The rust preventive coating composition comprises asphalt, metallic salt of petroleum sulfonic acid, metallic salt of petrolatum oxide, wax-like material, microwax, metallic salt of lanolin fatty acid, metallic salt of synthetic sulfonic acid, plasticizer, solvent, extender pigment, additive, reforming agent and inorganic running preventive agent. The extender pigment includes barium sulfate ranging not less than 20 wt % of the total amount of the extender pigment, and calcium carbonate ranging not less than 5 wt % of the total amount of the extender pigment. The reforming agent ranges from 1 to 10 wt % of the total amount of the rust preventive coating coposition. The inorganic running preventive agnet ranges from 0.5 to 10 wt % of the total amount of the rust preventive coating composition. Additionally, the rust preventive coating composition has a nonvolative content of 70 wt %. This rust preventive coating composition makes it possible to form both relatively thin and thick rust preventive coating films, without using two kinds of conventional coating compositions, exhibiting high performance of rust preventive coating while decreasing the used amount of organic solvent.

Rust preventive coating composition

Disclosed is an automobile bumper which is formed of a thermoplastic multicomponent resin composition and which is improved in weatherability and impact resistance at low temperatures and also in surface glossiness. Essentially the resin composition is a blend of 22-28 wt % of a hydrogenated block copolymer of an aromatic vinyl compound such as styrene and a conjugated diene such as butadiene, 32-56 wt % of a propylene-ethylene block copolymer in which the content of ethylene is 1-10 wt % and 22-28 wt % of an ethylene-propylene copolymer rubber. Optionally, up to 5 wt % of talc and/or up to 7 wt % of low-pressure low-density polyethylene may be added. Some physical properties of the ingredients are specified such that the resin composition has a melt index not lower than 5 g/10 min at 230.degree. C. under load of 2.16 kg and a modulus of elasticity in bending in the range from 2000 to 4000 kg/cm.sup.2.

Automobile bumper formed of thermoplastic multicomponent resin

Painting of an article formed of a synthetic resin, e.g. an automobile bumper formed of polyurethane resin, is accomplished by simplified operations and at reduced cost by using a paint of a desired color containing 5-40 wt % of an aprotic polar solvent, preferbly N-methyl-2-pyrrolidone. The paint is applied directly to a cleaned surface of the plastic article, followed by usual drying and baking. Application of a usual primer is omitted since the paint containing an adequate amount of aprotic polar solvent is excellent in adhesion to plastic surfaces. The obtained paint film is comparable to an ordinary top coat paint film formed on a primer layer in appearance, whether resistance and chemical resistance. When a two-toned paint coat is wished, another paint not containing any aprotic polar solvent is applied onto a selected area of the initially formed paint film, followed by drying and baking.

Method of painting article formed of synthetic resin

A method for finish coating on polyurethane formed articles, which comprises formulating a finish coating composition so as to have a content of pyrrolidone or its derivative represented by the general formula ##STR1## in which R stands for hydrogen or an alkyl group having at the most 4 carbon atoms, in an amount of 5-40% by weight upon the coating, applying this finish coating composition on the polyurethane formed article directly and heating the so called polyurethane formed article at a temperature of at least 50.degree. C. but lower than the thermal deformation temperature of the polyurethane formed article, said method being capable of attaining a coating layer exhibiting both the properties for a primer coat, namely, a better adhesion onto polyurethane formed articles, and for a finish coat, namely, better weather resistance, higher chemical resistance, favorable appearance and so on, with only a single application and permitting thus to dispense with the primer coating and the heat drying procedure therefor.

Method for finish coating on polyurethane formed articles

In a rust preventing wax treatment method which is applicable to automobile bodies already provided with a finish coat of paint, use is made of a wax which possesses not only thixotropy but also such a temperature-sensitive property that the viscosity of the wax decreases when heated and increases again when cooled near to room temperature. In the wax treatment method the wax and/or the article to be treated with the wax is heated and the wax, which is kept under action of a mechanical force to utilize its thixotropy, is applied to desired surfaces of the article. After that the waxed article is cooled near to room temperature. By this method the wax exhibits a very low viscosity when applied to the article and therefore can penetrate even into narrow spaces, and the applied wax soon solidifies as the waxed article is cooled. Therefore, a wax coating film of a sufficient thickness can be formed without suffering from dripping of the applied wax.

Rust preventing wax treatment method

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Hatano, Japan

Masashi Ohno