Water-soluble or water-disintegrable copolymer

1. A random copolymer based on α-β-unsaturated monocarboxylic acid, wherein the copolymer has a molar mass of 30,000 to <100 000 g/mol and a polydispersity of 2 to 3, and wherein the α-β-unsaturated monocarboxylic acid has a weight fraction of >50% by weight, based on the total weight of the copolymer, wherein the copolymer is in a form of a powder or pellet, and the copolymer has in addition to the α-β-unsaturated monocarboxylic acid as comonomer an alkyl ester and/or alkoxy alkyl ester, of an α-β-unsaturated monocarboxylic acid.

2. The random copolymer according to claim 1 , wherein the molar mass is 30,000 g/mol to 90,000 g/mol.

3. The random copolymer according to claim 1 , wherein the α-β-unsaturated monocarboxylic acid has a weight fraction of 60% by weight to 95% by weight, based on the total weight of the copolymer.

4. The random copolymer according to claim 1 , wherein the ester of the α-β-unsaturated monocarboxylic acid is selected from the group consisting of methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, methoxyethyl acrylate, glycidyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, methoxyethyl methacrylate, glycidyl methacrylate and mixtures thereof.

5. The random copolymer according to claim 1 , wherein the ester has a weight fraction of 5% by weight to 40% by weight, based on the total weight of the copolymer.

6. The random copolymer according to claim 1 , wherein the copolymer is a copolymer of the α-β-unsaturated monocarboxylic acid and an ester of an α-β-unsaturated monocarboxylic acid.

7. A random copolymer based on α-β-unsaturated monocarboxylic acid, wherein the copolymer has a molar mass of 30,000 to <100 000 g/mol and a polydispersity of 2 to 3, the α-β-unsaturated monocarboxylic acid has a weight fraction of >50% by weight, based on the total weight of the copolymer, the copolymer is in a form of a powder or pellet, and the copolymer is a solution copolymer.

8. The random copolymer according to claim 1 , wherein the copolymer has a glass transition temperature of 60° C. to 140° C.

9. The random copolymer according to claim 1 , wherein the copolymer has a melt flow index of 5 g/10 min to 50 g/10 min.

10. The random copolymer according to claim 1 , wherein the copolymer is disintegrable or soluble or substantially soluble in an aqueous, pH-neutral environment and/or in an aqueous, alkaline environment.

11. The copolymer according to claim 1 , wherein the copolymer is provided or compounded with an impact modifier reactive toward carboxyl groups.

12. The copolymer according to claim 11 , wherein the impact modifier has a weight fraction of 10% by weight to 40% by weight, based on the total weight of the copolymer provided or compounded with the impact modifier.

13. A process of preparing the copolymer according to claim 1 , wherein an α-β-unsaturated monocarboxylic acid and a comonomer comprising an ester of an α-β-unsaturated monocarboxylic acid, are copolymerized in solution.

14. A copolymer compound comprising a copolymer according to claim 1 and an impact modifier.

15. A process of preparing a copolymer compound according to claim 14 , comprising mixing a copolymer in a melt with an impact modifier under action of shearing forces, a proportion of copolymer and impact modifier being selected preferably such that the copolymer forms a continuous phase and the impact modifier forms a discontinuous phase.

16. A random copolymer based on α-β-unsaturated monocarboxylic acid, wherein the copolymer has a molar mass of 30,000 to <100 000 g/mol and a polydispersity of 2 to 3, the α-β-unsaturated monocarboxylic acid has a weight fraction of >50% by weight, based on the total weight of the copolymer, the copolymer is in a form of a powder or pellet, and the copolymer has in addition to the α-β-unsaturated monocarboxylic acid as comonomer an ester of an α-β-unsaturated monocarboxylic acid.