Patent ID: 7951885

Claim:
A polymer based on a copolymer at least comprising a) at least one hydrophilically substituted alkyl vinyl ether of formula I where R1, R2, R3, independently of one another, is H or C1 to C6 alkyl, and R4 is a radical which carries at least one hydroxyl group, and b) at least one crosslinking agent of formula II and/or III and/or IV where X is a divalent alkyl radical having 2 to 5 C atoms in which one or more methylene groups which are not adjacent and are not located in the direct vicinity of N may be replaced by O, C═O, S, S═O, SO 2 , NH, NOH or N and one or more H atoms of the methylene groups may be substituted, independently of one another, by hydroxyl, C1-C6-alkyl, halogen, NH 2 , C5-C10-aryl, NH—(C1-C8)-alkyl, N—(C1-C8)-alkyl 2 , C1-C6-alkoxy or C1-C6-alkyl-OH, where Y1 and Y2 in formula III and IV are, independently of one another, C1 to C10 alkyl or cycloalkyl, where one or more non-adjacent methylene groups or methylene groups which are not located in the direct vicinity of N may be replaced by O, C═O, S, S═O, SO 2 , NH, NOH or N and one or more H atoms of the methylene groups may be substituted, independently of one another, by hydroxyl, C1-C6-alkyl, halogen, NH 2 , C5-C10-aryl, NH(C1-C8)alkyl, N(C1-C8)alkyl 2 , C1-C6-alkoxy or C1-C6-alkyl-OH, or C6 to C18 aryl, where one or more H atoms in the aryl system may be substituted, independently of one another, by hydroxyl, C1-C6-alkyl, halogen, NH 2 , NH(C1-C8)alkyl, N(C1-C8)alkyl 2 , C1-C6-alkoxy or C1-C6-alkyl-OH, and A is a divalent alkyl radical having 2 to 5 C atoms in which one or more non-adjacent methylene groups or methylene groups which are not located in the direct vicinity of N may be replaced by O, C═O, S, S═O, SO 2 , NH, NOH or N and one or more H of the methylene groups may be substituted, independently of one another, by hydroxyl groups, C1-C6-alkyl, halogen, NH 2 , C5-C10-aryl, NH(C1-C8)alkyl, N(C1-C8)alkyl 2 , C1-C6-alkoxy or C1-C6-alkyl-OH, which polymer has been derivatised by separation effectors, or has been derivatised by structures which have been attached to the polymer by graft polymerisation, or has been derivatised by structures which have been attached to the polymer by graft polymerisation with cerium(IV) catalysis.