Method for coating metals
Process for coating metallic surfaces with a copolymer of olefins and/or dienes, acidic monomers and, optionally, further monomers, the metal surfaces being contaminated with oil and/or grease, and the contamination not being removed prior to coating. Metallic surface obtainable by means of the process.
1. A process for coating a metallic surface contaminated with oil and/or grease comprising the step of contacting said metallic surface with a coating comprising a copolymer synthesized from:
(A) 20% to 95% by weight of monoethylenically unsaturated hydrocarbons and/or hydrocarbons having two conjugated double bonds;
(B) 5% to 50% by weight of monoethylenically unsaturated monomers which contain acid groups, and/or the anhydrides or salts thereof; and
(C) 0 to 30% by weight of further ethylenically unsaturated monomers different from (A) and (B); and
wherein said contamination is not removed prior to coating.
2. The process according to claim 1 , wherein (A) comprises at least one alkene selected from the group consisting of ethene, propene, 1-butene, 2-butene, 1-pentene, 1-hexene, 1-heptene, and 1-octene.
3. The process according to claim 1 , wherein said acid group is at least one group selected from the group consisting of carboxyl groups, sulfonic acid groups, and phosphonic acid groups.
4. The process according to claim 3 , wherein (A) is ethene and (B) is (meth)acrylic acid.
5. The process according to claim 1 , wherein 0.5 to 50 mol % of the acid groups present in said copolymer are in neutralized form.
6. The process according to claim 1 , wherein said copolymer is in the form of a formulation with water or with an aqueous solvent mixture comprising at least 75% by weight of water.
7. The process according to claim 6 , wherein said copolymer is formulated only in water and the concentration of said copolymer is from 0.5 to 50% by weight, based on the sum of all components of the formulation.
8. The process according to claim 1 , wherein said copolymer is applied by powder coating.
9. The process according to claim 6 , wherein said copolymer is applied by spraying, squirting, dipping, brushing, or electrophoretic coating.
10. The process according to claim 1 , wherein said metallic surface comprises a metal selected from the group consisting of aluminum, steel, steel coated with Zn, Al, Ni, Sn, Cr, and alloys thereof.
11. A coated metallic surface coated according to the process of claim 1 .
12. The coated metallic surface according to claim 11 , wherein the thickness of said coating is 0.1 to 20 μm.
13. The coated metallic surface according to claim 11 , wherein one or more additional coating films are applied over the coating comprising said copolymer.