Polyfunctional polymers based on phosphonate units and amine units

1. A polyfunctional polymer comprising:

monomer units u1 bearing phosphonic acid functions —P(═O)(OH) 2 in acid form or, totally or partly, in deprotonated form;

monomer units u2 bearing amine functions, wherein the amine functions of the monomer units u2 comprise primary amines —NH 2 that are optionally totally or partly protonated in ammonium form NH 3 + ;

optionally, monomer units u3 bearing alcohol functions —OH.

2. The polyfunctional polymer as claimed in claim 1 , which comprises monomer units u3 bearing alcohol functions —OH, with an amine/alcohol mole ratio corresponding to the total amount of amine functions present in the polymer relative to the total amount of alcohol functions present in the polymer between 1:4 and 4:1.

3. The polyfunctional polymer as claimed in claim 1 , which also comprises hydrophobic groups.

4. A process for preparing a polyfunctional polymer as claimed in claim 1 , the process comprising:

a step (E1) of radical polymerization of a mixture comprising:

ethylenically unsaturated monomers m1 bearing phosphonic acid functions —P(═O)(OH) 2 in their acid form or totally or partly in deprotonated form;

ethylenically unsaturated monomers m2 bearing protected amine functions;

optionally, ethylenically unsaturated monomers m3 bearing protected alcohol functions;

via which a polymer P1 bearing phosphonate, protected amine and optionally protected alcohol functions is obtained;

and then

a step (E2) of deprotection of at least some of the protected amine functions, and, where appropriate, the protected alcohol functions, of the polymer P1 obtained in step (E1).

5. A process for preparing a polyfunctional polymer as claimed in claim 1 , the process comprising a step (E) of grafting monomers m bearing phosphonic acid functions, in their acidic form and/or totally or partly in deprotonated form, onto a base polymer comprising monomer units u2 bearing amine functions, which are optionally totally or partly protonated, and, optionally, monomer units u3 bearing alcohol functions —OH.

6. The preparation process as claimed in claim 5 , in which the monomers m are:

monomers bearing aldehyde, epoxy or halogen functions, which are capable of forming covalent bonds by reacting with the amine functions borne by the base polymer;

or

monomers bearing phosphonic acid functions, which are also ethylenically unsaturated.

7. The preparation process as claimed in claim 6 , in which the monomers m are vinylphosphonic acid or vinyldiphosphonic acid monomers, and in which the reaction between the monomers m and the base polymer in step (E) is performed at a pH of less than 8.

8. A method for the finishing treatment of metal surfaces intended to be painted or varnished, or for the cleaning of metal surfaces, the method comprising using the polymer as claimed in claim 1 .

9. The method of claim 8 , wherein the metal surface is given an anti-wear effect.

10. The polyfunctional polymer as claimed in claim 3 , wherein the hydrophobic groups are linear or branched C8 to C22 alkyl or alkenyl groups.

11. The process of claim 4 , wherein the ethylenically unsaturated monomers m1 are vinylphosphonic acid monomers CH2=CH—P(O)(OH) 2 and/or vinyldiphosphonic acid monomers CH 2 ═C(—PO 3 H 2 ) 2 .

12. The process of claim 4 , wherein the ethylenically unsaturated monomers m2 are N-vinylformamide or N-vinylacetamide monomers.

13. The process of claim 4 , wherein the ethylenically unsaturated monomers m3 are-vinyl acetate monomers.

14. The process of claim 4 , wherein the step (E2) of deprotection is hydrolysis.

15. The preparation process as claimed in claim 6 , wherein the halogen functions are —Cl or —Br.

16. The preparation process as claimed in claim 6 , wherein the monomers bearing phosphonic acid functions are vinylphosphonic acid or vinyldiphosphonic acid monomers.

17. The preparation process as claimed in claim 7 , wherein the reaction between the monomers m and the base polymer in step (E) is performed at a pH of less than 7.

18. The method of claim 8 , wherein the metal surfaces are aluminum surfaces.