Patent GB-954566-A (GB)
Title: Method and composition for producing adherent coatings on metal parts
IPC: C23C22/48
Filed: 1961-08-29
Abstract: A coating composition for treating metal surface (see Division B2) comprises (1) an alkene phosphonic acid and (2) either polyvinyl phosphonic acid or a homopolymer or copolymer of an acid derivative of vinyl phosphonic acid which contains per monomer unit, only one free hydroxyl group at the phosphorus atom, or a copolymer of vinyl phosphonic acid or a phosphorus free polymer containing an acid group, or a copolymer of a vinyl alkyl ether and maleic anhydride or a mixture of any two or more of such compounds dissolved in water and/or an organic solvent.  As solvents water, aliphatic alcohols containing one to four carbon atoms per molecule especially isopropanol, and mixtures thereof may be used.  Suitable copolymerizable compounds are acrylic acid, methacrylic acid and the esters, amides and nitriles thereof, vinyl esters e.g. acetate and propionate, maleic anhydride and crotonic acid. A wetting agent may be incorporated.  In examples compositions consist of 1 (a) (b) vinyl phosphonic acid, polyacrylic acid and water, (c) vinyl phosphonic acid, vinyl methyl ether-maleic anhydride and water, (d) vinyl phosphonic acid, vinyl phosphonic acid-vinyl acetate copolymer and water, (e) vinyl phosphonic acid, vinyl phosphonic acid monoethylester-vinyl acetate copolymer and water, (f) propene phosphonic acid, vinyl phosphonic acid-acrylic acid copolymer and water, (g) vinyl phosphonic acid, polyacrylic acid, vinyl phosphonic acid-acrylonitrile copolymer and water, (h) alkyl phosphonic acid, polyvinyl phosphonic acid and water, (i) vinyl phosphonic acid, polyvinylphosphonic acid and water, (k) vinyl phosphonic acid, vinyl phosphonic acid-acrylic acid methyl ester copolymer and water, (l) vinyl phosphonic acid, vinyl phosphonic acid-acrylic acid, water and wetting agent, (m) vinyl phosphonic acid, vinyl phosphonic acid-acrylic acid copolymer and water, (n) vinyl phosphonic acid, vinyl phosphonic acid acrylic acid copolymer, water and wetting agent, (2) vinyl phosphonic acid, polyvinyl phosphonic acid and water and (3) vinyl phosphonic and polyvinyl phosphonic acid, and isopropanol/water.ALSO:A process for producing adherent coatings on metal surfaces especially for preventing corrosion and/or for securing good adherence of lacquers and varnishes comprises treating the metal surface with a composition comprising (1) an alkene phosphonic acid and (2) either polyvinyl-phosphonic acid or a homopolymer or copolymer of an acid derivative of vinyl phosphonic acid which contains per monomer unit only one free hydroxyl group at the phosphorus atom or a copolymer of vinylphosphonic acid or a phosphorus-free polymer containing an acid group or a copolymer or vinyl alkyl ether and maleic anhydride or a mixture of any two or more of such compounds dissolved in water and/or an organic solvent and drying the treated metal surface. As solvents, water, aliphatic alcohols containing 1-4 carbon atoms per molecule especially isopropanol and mixtures thereof may be used. A melting agent may be incorporated. In examples (1) steel plates treated with a degreasing agent which had been rendered alkaline and contained emulsifiers and silicates, were rinsed with cold water and then immersed in a solution of vinyl phosphonic acid and vinyl phosphoric acid-acrylic acid copolymer (molar ratio 1 : 1) in water. The plates were then dried and coated with an alkyd resin baking varnish in two stages and baked when they were found to have excellent corrosion resistance and adherence. Similar results were obtained using (a) and (b) vinylphosphonic acid polyacrylic acid and water, (c) vinylphosphonic acid, vinyl methyl ether-maleic anhydride copolymer and water, (d) vinyl phosphonic acid, vinylphosphonic acid-vinyl acetate copolymer (molar ratio 2 : 1) and water, (e) vinylphosphonic acid, vinylphosphonic acid monoalkyl ether-vinyl acetate copolymer (molar ratio 1 : 1) and water, (f) propane phosphonic acid, vinylphosphonic acid-acrylic acid copolymer and water, (g) vinylphosphonic acid, polyacrylic acid, vinylphosphonic acid-acrylonitrile copolymer and water, (h) alkyl phosphonic acid, polyvinylphosphonic acid and water, (i) vinylphosphonic acid, polyvinylphosphonic acid and water, (k) vinylphosphonic acid, vinylphosphonic acid-acrylic acid or polymer and water, (1) vinylphosphonic acid, vinylphosphonic acid-acrylic and copolymer, wetting agent and water, (m) vinylphosphonic acid, vinylphosphonic acid-acrylic acid copolymer and water, and (n) vinylphosphonic acid, vinylphosphonic acid-acrylic acid copolymer, wetting agent and water.  (2) Sealed steel sheets were treated in a spraying plant for 30 seconds at room temperature and under a spraying pressure of 0.6 atmospheres with a solution of vinylphosphonic acid and polyvinylphosphonic acid in water, dried and coated with a varnish in three stages as usual for car bodies. Very good corrosion protection and excellent varnish adhesion were obtained. (3) Sealed steel plates were pickled for 10 minutes with hydrochloric acid, rinsed with cold water and immersed for 20 seconds in a solution consisting of vinylphosphonic acid, polyvinylphosphonic acid, isopropanol and water.  The dried plates were rust resistant to concentrated hydrochloric acid solution fumes.ALSO:A process for producing adherent coatings on metal surfaces, especially for preventing corrosion and/or for securing good adherence of lacquers and varnishes comprises treating the metal surface with a composition comprising (1) an alkene phosphonic acid and (2) either polyvinyl phosphonic acid or a homopolymer or copolymer of an acid derivative of vinylphosphonic acid which contains, per monomer unit, only one free hydroxyl group at the phosphorus atom, and a copolymer of vinyl phosphonic acid or a phosphorus-free polymer containing an acid group, or a copolymer of a vinyl alkyl ether and maleic anhydride or a mixture of any two or more of such compounds dissolved in water and/or an organic solvent, and drying the treated metal surface.  As solvents, water, aliphatic alcohols containing 1-4 carbon atoms per molecule, especially isopropanol, and mixtures thereof may be used. A wetting agent may be incorporated.  In Examples (1) steel plates treated with a degreasing agent which had been rendered alkaline and contained emulsifiers and silicates, were rinsed with cold water and then immersed in a solution of vinyl phosphonic acid and vinyl phosphonic acid-acrylic acid copolymer (molar ratio 1 : 1) in water. The plates were then dried and coated with an alkyd resin baking varnish in two stages and baked, when they were found to have excellent corrosion resistance and adherence.  Similar results were obtained using (a) and (b) vinyl phosphonic acid, polyacrylic acid and water, (c) vinyl phosphonic acid, vinyl methyl ether-maleic anhydride copolymer and water, (d) vinyl phosphonic acid, vinyl phosphonic acid-vinyl acetate copolymer (molar ratio 2 : 1) and water, (e) vinyl phosphonic acid, vinyl phosphonic acid monoethyl ester-vinyl acetate copolymer (molar ratio 1 : 1) and water, (f) propene phosphonic acid, vinyl phosphonic acid-acrylic acid copolymer and water, (g) vinyl phosphonic acid, polyacrylic acid, vinyl phosphonic acid-acrylonitrile copolymer and water, (h) alkyl phosphonic acid, polyvinyl phosphonic acid and water, (j) vinyl phosphonic acid, polyvinyl phosphonic acid and water, (k) vinyl phosphonic acid, vinyl phosphonic acid-acrylic acid copolymer and water, (l) vinyl phosphonic acid, vinyl phosphonic acid-acrylic acid copolymer, wetting agent and water, (m) vinyl phosphonic acid, vinyl phosphonic acid-acrylic acid copolymer and water, and (n) vinyl phosphonic acid, vinyl phosphonic acid-acrylic acid coplymer, wetting agent and water; (2) steel sheets were treated in a spraying plant for 30 seconds at room temperature and under a spraying pressure of 0,6 atmospheres with a solution of vinyl phosphonic acid and polyvinyl phosphonic acid in water, dried and coated with a varnish in three stages as usual for car bodies. Very good corrosion protection and excellent varnish adhesion were obtained; (3) scaled steel plates were pickled for 10 minutes with hydrochloric acid, rinsed with cold water and immersed for 30 seconds in a solution consisting of vinyl phosphonic acid, polyvinyl phosphonic acid, isopropanol and water.  The dried plates were rust resistant to concentrated hydrochloric acid solution fumes.