# US 5,075,165 A · Composite paint film > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,075,165 A - Document ID: US5075165A - Status: Granted - Kind: A - Application number: 07/521,955 - Filed: 1990-05-11 - Granted: 1991-12-24 - Earliest claimed: 1989-05-18 - Assignees: Nissan Motor Co., Ltd. - Inventors: Hiroyuki Kishi; Hitoshi Kimura; Katsuya Yamamoto; Yoshinobu Tamura; Tsuneo Sakauchi; Masahide Nagaoka; Yoichi Masubuchi; Eisaku Nakatani - Web page: https://patentgrep.com/patent/US5075165A ## CPC - C09D 5/4457: {containing special additives, e.g. pigments, polymeric particles} - Y10T 428/259: Silicic material - Y10T 428/31511: Of epoxy ether - Y10T 428/31515: As intermediate layer - Y10T 428/31678: Of metal - Y10T 428/31699: Ester, halide or nitrile of addition polymer - C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A composite paint film formed on a steel sheet of an automotive vehicle body. The composite paint film comprises an electrodeposition paint film (I) coated on the steel sheet, and an intermediate coat paint film (II) coated on the first paint film. The electrodeposition paint film is formed of an epoxy-based cationic electrodeposition paint composition and has a minimum melt viscosity not less than 0.2 during hardening. The epoxy-based cationic electrodeposition paint composition includes an amine-added epoxy resin (1) of the type which may be hardened with a blocked isocyanate, a colloidal silica-containing gelled particulate (2), and an alkyltin ester compound of a liquid aliphatic carboxylic acid. The above-mentioned colloidal silica-containing gelled particulate is formed by dispersing a mixture of an acrylic copolymer having a hydrolizable alkoxysilane group and a cationic group and a cationic acidic colloidal silica in water to carry out a cross-linking reaction in particles of the colloidal silica. The second paint film (II) has a hardening starting time ranging from 15 to 20 minutes. ## Claims ### Claim 1 A composite paint film comprising: a first paint film (I) formed of an epoxy-based cationic electrodeposition paint composition and having a minimum melt viscosity not less than 0.2 during hardening, said minimum melt viscosity being determined according to a logarithmic decrement of viscoelasticity of said first paint film and by an oscillated pendulum type viscoelasticity measuring device, said epoxy-based cationic electrodeposition paint composition including an amine-added epoxy resin (1) of the type which may be hardened with a blocked isocyanate, a colloidal silica-containing gelled particulate (2) which is formed by dispersing a mixture of an acrylic copolymer having a hydrolyzable alkoxysilane group and a cationic group and a cationic acidic colloidal silica in water to carry out a cross-linking reaction in particles of said colloidal silica, and an alkyltin ester compound (3) of a liquid aliphatic carboxylic acid; and a second paint film (II) coated on said first paint film, said second paint film having a hardening starting time ranging from 5 to 20 minutes, said. hardening starting time being determined according to a logarithmic decrement of viscoelasticity of said second paint film and by said oscillated pendulum type viscoelasticity measuring device. ### Claim 2 (depends on 1) A composite paint film as claimed in claim 1, wherein said blocked isocyanate-hardening type amine-added epoxy resin is a reaction product of a reaction between a polyepoxide compound and one selected from the group consisting of amines a hydroxyl compound having a primary amino group. ### Claim 3 (depends on 2) A composite paint film claimed in claim 2, wherein said amines are selected from the group consisting of a mixture of primary monoamines and primary polyamines, a mixture of secondary monoamines and secondary polyamines, a mixture of primary and secondary polyamines, and a mixture of secondary monoamines and secondary polyamines which has a primary amino group. ### Claim 4 (depends on 2) A composite paint film as claimed in claim 2, wherein said polyepoxide compound has at least two epoxy groups per molecular and a number average molecular weight of at least 200. ### Claim 5 (depends on 2) A composite paint film as claimed in claim 2, wherein said polyepoxide compound is formed by a reaction between a polyphenol compound and epichlorohydrin. ### Claim 6 (depends on 1) A composite paint film as claimed in claim 1, wherein said acrylic copolymer is formed by copolymerization of a mixture including a polymerizable unsaturated vinylsilane monomer having a vinyl-type double bond and a hydrolizable alkoxysilane group, and a polymerizable unsaturated monomer having a vinyl-type double bond and a cationic group. ### Claim 7 (depends on 6) A composite paint film as claimed in claim 6, wherein said mixture includes a polymerizable unsaturated monomer having a vinyl type double bond and a hydroxyl group. ### Claim 8 (depends on 6) A composite paint film as claimed in claim 6, wherein said polymerizable vinylsilane monomer is one selected from the group consisting of vinyltrimethoxy silane, vinyltriethoxy silane, vinyltris-.beta.-methoxyethoxy silane, .gamma.-(meth)acryloyl oxypropyl trimethoxy silane and .gamma.-methacryloyl oxypropylmethyldimethoxy silane. ### Claim 9 (depends on 6) A composite paint film as claimed in claim 6, wherein said polymerizable unsaturated monomer having a vinyl-type double bond and a cationic group is selected from the group consisting of dimethylaminopropyl (meth)acrylate, and diethylaminoethyl (meth)acrylate. ### Claim 10 (depends on 7) A composite paint film as claimed in claim 7, wherein said polymerizable unsaturated monomer having a vinyl-type double bond and a hydroxyl group is selected from the group consisting of 2-hydroxyethyl (meth)acrylate and hydroxypropyl (meth)acrylate. ### Claim 11 (depends on 7) A composite paint film as claimed in claim 7, wherein said mixture includes an additional monomer selected from the group consisting of an alkyl ester of (meth)acrylic acid, a vinyl aromatic monomer, an o amide derivative of (meth)acrylic acid and (meth)acrylonitrile. ### Claim 12 (depends on 11) A composite paint film as claimed in claim 11, wherein said alkyl ester of (meth)acrylic acid is selected from the group consisting of methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate and isopropyl (meth)acrylate. ### Claim 13 (depends on 11) A composite paint film as claimed in claim 11, wherein said vinyl aromatic monomer is selected from the group consisting of sytrene, .alpha.-methyl styrene and vinyl toluene. ### Claim 14 (depends on 6) A composite paint film as claimed in claim 6, wherein said polymerizable unsaturated monomer having a vinyl-type double bond and a hydrolizable alkoxysilane is within a range from 1 to 30% by weight of said mixture. ### Claim 15 (depends on 14) A composite paint film as claimed in claim 14, wherein said-monomer is within a range from 3 to 20% by weight of said mixture. ### Claim 16 (depends on 6) A composite paint film as claimed in claim 6, wherein said polymerizable unsaturated monomer having a vinyl-type double bond and a cationic group is within a range from 5 to 30% by weight of said mixture. ### Claim 17 (depends on 16) A composite paint film as claimed in claim 16, wherein said monomer is within a range from 5 to 25% by weight of said mixture. ### Claim 18 (depends on 7) A composite paint film as claimed in claim 7, wherein said polymerizable unsaturated monomer having a vinyl type double bond and a hydroxyl group is within a range from 0 to 30% by weight of said mixture. ### Claim 19 (depends on 18) A composite paint film as claimed in claim 18, wherein said monomer is within a range from 5 to 20% by weight of said mixture. ### Claim 20 (depends on 11) A composite paint, film as claimed in claim 11, wherein said additional monomer is within a range from 10 to 94% by weight of said mixture. ### Claim 21 (depends on 20) A composite paint film as claimed in claim 20, wherein said additional monomer is within a range from 35 to 82% by weight. ### Claim 22 (depends on 1) A composite paint film as claimed in claim 1, wherein said acrylic copolymer has an amine value ranging from 10 to 100, a hydroxyl value ranging from 0 to 200, and a number average molecular weight of 5000 to 100000. ### Claim 23 (depends on 1) A composite paint film as claimed in claim 1, wherein said acrylic copolymer has an amine value ranging from 15 to 80, a hydroxylic value ranging from 30 to 130, and a number average molecular weight of 7000 to 30000. ### Claim 24 (depends on 1) A composite paint film as claimed in claim 1, wherein said cationic acidic colloidal silica has an average particle size ranging from 0.004 to 0.1 .mu.m. ### Claim 25 (depends on 1) A composite paint film as claimed in claim 1, wherein said cationic acidic colloidal silica s within a range from 5 to 30 parts by weight relative to 100 parts by weight of a resinous solid content of said electrodeposition paint composition. ### Claim 26 (depends on 1) A composite paint film as claimed in claim 1, wherein said cationic acidic colloidal silica is within a range from 10 to 20 parts by weight of a resinous solid content of said electrodeposition paint composition. ### Claim 27 (depends on 1) A composite paint film as claimed in claim 1, wherein said alkyltin ester compound is selected from the group consisting of dibytyltin laurate, dibutyltin diacetate and dioctyltin diacetate. ### Claim 28 (depends on 1) A composite paint film as claimed in claim 1, wherein said alkyltin ester compound is within a range from 0.1 to 10 parts by weight relative to 100 parts by weight of a resinous solid content of said electrodeposition paint composition. ### Claim 29 (depends on 1) A composite paint, film as claimed in claim 1, wherein said alkyltin ester compound is within a range from 0.2 to 5 parts by weight relative to 100 parts by weight of a resinous solid content of said electrodeposition paint composition. ### Claim 30 An outer panel of an automotive vehicle body, comprising: a steel sheet forming part of the automotive vehicle body; a first paint film (I) coated on said steel sheet and formed of an epoxy-based cationic electrodeposition paint composition and having a minimum melt viscosity not less than 0.2 during hardening, said minimum melt viscosity being determined according to a logarithmic decrement of viscoelasticity of said first paint film and by an oscillated pendulum type viscoelasticity measuring device, said epoxy-based cationic electrodeposition paint composition including an amine-added epoxy resin (1) of the type which may be hardened with a blocked isocyanate, a colloidal silica containing gelled particulate (2) which is formed by dispersing a mixture of an acrylic copolymer having a hydrolyzable alkoxysilane group and a cationic group and a cationic acidic colloidal silica in water to carry out a cross-linking reaction in particles of said colloidal silica, and an alkyltin ester compound (3) of a liquid aliphatic carboxylic acid; and a second paint film (II) coated on said first paint film, said second paint film having a hardening starting time ranging from 15 to 20 minutes, said hardening starting time being determined according to a logarithmic decrement of viscoelasticity of said second paint film and by said oscillated pendulum type viscoelasticity measuring device. ### Claim 31 A method for preventing corrosion of steel panels which comprises coating at least one surface of said panels with a composite paint film comprising a first paint film (I) formed of an epoxy-based cationic electrodeposition paint composition and having a minimum melt viscosity not less than 0.2 during hardening, said minimum melt viscosity being determined according to a logarithmic decrement of viscoelasticity of said first paint film and by an oscillated pendulum type viscoelasticity measuring device, said epoxy-based cationic electrodeposition paint composition including an amine-added epoxy resin (1) of the type which may be hardened with a blocked isocyanate, a colloidal silica-containing gelled particulate (2) which is formed by dispersing a mixture of an acrylic copolymer having a hydrolyzable alkoxysilane group and a cationic group and a cationic acidic colloidal silica in water to carry out cross-lining reactions in particles of said colloidal silica, an an alkyltin ester compound (3) of a liquid aliphatic carboxylic acid; and a second paint film (II) coated on said first paint film, said second paint film having a hardening starting time ranging from 5 to 20 minutes, said hardening starting time being determined according to a logarithmic decrement of viscoelasticity of said second paint film and by said oscillated pendulum type viscoelasticity measuring device.