Patent ID: 8629227

Claim:
A copolymer, consisting essentially of, in copolymerized form: (A) 0.01% to 20% by weight of at least one ethylenically unsaturated compound of formula (I), R—(C═O)—R 1 (I), wherein R is a straight-chain C 1 -C 4 alkyl radical, a branched, optionally substituted C 3 or C 4 alkyl radical, an aryl radical, or a R 1 , and R 1 is wherein R 2 to R 6 are each, independently, hydrogen, alkyl, aryl, OH, OCH 3 , OC 2 H 5 , SH, SCH 3 , SC 2 H 5 , F, Cl, Br, CN, CO 2 H, CO 2 alkyl, CO 2 aryl, CF 3 , N(alkyl) 2 , N(alkyl)(aryl), N(aryl) 2 , N + (alkyl) 3 A − , N + H(alkyl) 2 A − , wherein A − is an anion of an acid, and at least one but not more than three of the radicals R 2 to R 6 is or are selected from the group consisting of wherein X is a divalent, optionally substituted alkylene radical —(CH 2 ) m —, a radical with m=1 to 10, wherein R′ and R″ are each independently hydrogen, alkyl, aryl, CO 2 H, CO 2 CH 3 or CO 2 C 2 H 5 , a perfluorinated alkylene radical —(CF 2 ) m — with m=1 to 10, an oxaalkylene radical of a formula —(CH 2 ) n —O—(CH 2 ) p —, a perfluorinated oxaalkylene radical of a formula —(CF 2 ) n —O—(CF 2 ) p — with n=1 to 5 and p=1 to 5, an optionally perfluorinated polyoxaalkylene radical having 2 to 20 oxygen atoms which are joined to one another via at least one —CH 2 —, —CF 2 —, or —CH 2 —CH(CH 3 )— group, or are an alkylene radical of a formula —(CH 2 ) a —O—CO—O(CH 2 ) b —, —(CH 2 ) a —O—CO—NH—(CH 2 ) b —, —(CH 2 ) a —NH—CO—O—(CH 2 ) b —, —(CH 2 ) a —CO—(CH 2 ) b —, or —(CH 2 ) a —O—CO—(CH 2 ) b — with a=1 to 10 and b=1 to 10, a phenylene radical which is optionally substituted by alkyl, OH, OCH 3 , OC 2 H 5 , SH, SCH 3 , SC 2 H 5 , Cl, F, N(alkyl) 2 , or N(CH 3 )C 6 H 5 in at least one of an o-, m-, and p-position, a cycloalkylene radical having 5 to 10 carbon atoms, or a (bis)methylenecycloalkylene radical having 6 to 12 carbon atoms, Y is hydrogen, alkyl, or aryl, and Z is O or NY, or, if R is an aryl radical, one of the radicals R 2 or R 6 is optionally a sulfur atom which connects the aryl radical R in an o-position to R 1 ; (B) 80% to 99.99% by weight of at least one N-vinyllactam of formula (VII), wherein P and Q are independently of one another are at least one of hydrogen and alkyl, and d is an integer from 2 to 8.