Polymers for metal surface treatment

1. A polymer P obtained by radical copolymerization of a mixture of:

acrylic acid;

methacrylic acid; and

at least one allylcatechol selected from the group consisting of 4-allylbenzene-1,2-diol; 3-allylbezene-1,2-diol, having the formulae below, and mixtures thereof

2. The polymer P of claim 1 , wherein the at least one allylcatechol is a mixture of 4-allylbenzene-1,2-diol and 3-allylbenzene-1,2-diol.

3. The polymer P of claim 1 , wherein the polymer has a molecular weight between 10 and 150 kDa.

4. The polymer P of claim 1 , wherein the polymer contains acrylic acid (AA) at a content of 10 to 90% in mol; methacrylic acid (MAA) at a content of 1 to 70% in mol, and allylcatechol at a content of 1 to 20% in mol, each of the molar ratio being calculated on the basis of the total quantity of AA, MAA and allylcatechol.

5. A method, comprising treating a metallic surface intended to be coated by a paint, a varnish or an adhesive with at least one polymer P as defined in claim 1 .

6. The method of claim 5 , wherein the metal surface is a surface comprising a metal selected from the group consisting of aluminum, steel, zinc, magnesium and their alloys.

7. The method of claim 5 , wherein a conversion composition a is applied on the metallic surface for forming a conversion coating thereon, and wherein:

said conversion composition include all or part of the polymer P as an additive; and/or

the conversion coating is applied on the metallic surface, and then all or part of the polymer P is applied on the conversion coating.

8. The method according to claim 5 , wherein all or part of the polymer P is present in a paint, a varnish or a coating applied on the surface.

9. A process for coating a metallic surface with a paint, a varnish or an adhesive, comprising a step of treating said surface with at least one composition including at least one polymer P as defined in claim 1 .

10. The process of claim 9 , wherein the process is for coating a metallic surface with a paint.

11. The process of claim 9 , wherein the composition comprising the polymer P is:

a conversion composition including a polymer P; and/or

a solution or a dispersion of the polymer P; and/or

the paint, varnish or adhesive, that comprise a polymer P.

12. A conversion composition comprising at least one polymer P as defined in claim 1 .

13. A paint, varnish or adhesive composition containing at least one polymer P as defined in claim 1 .

14. A material comprising a metal surface which is in all or part (i) treated with at least one polymer P as defined in claim 1 and (ii) covered by a paint, a varnish or an adhesive.

15. The polymer P of claim 2 , wherein the mixture has a molar ratio of 4-allylbenzene-1,2-diol to 3-allylbezene-1,2-diol between 30/70 and 70/30.

16. The method of claim 6 , wherein the metal surface is a surface of aluminum or aluminum alloy.

17. The method according to claim 8 , wherein all or part of the polymer P is present in a paint, a varnish or a coating applied on the surface after application of a conversion coating on the metal surface.

18. The process of claim 11 , wherein the composition comprising the polymer P is a solution or a dispersion of the polymer P applied on the surface after having applied a conversion coating on the surface to be treated.

19. The material of claim 14 , wherein said material is a material having a metal surface in all or part covered by:

at least one coating comprising the at least one polymer P; and/or

a layer comprising a reaction product of the at least one polymer P with a metal of the treated surface or another compound present in the layer.