Patent ID: 8765897

Claim:
A polymer based on a copolymer, which is in the form of polymeric particles, 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, wherein a) and b) have been copolymerized and the resultant polymer is in the form of polymeric particles, wherein at least one of the following conditions I to IV is satisfied I) the polymer is porous having pore sizes between 2 and 200 nm, II) the polymer is in the form of particles having a diameter between 3 and 300 μm, III) b) is a crosslinking agent of formula II, or IV) b) is a crosslinking agent of formula IV.