Patent ID: 7939818

Claim:
A polymer comprising a repeating unit of the formula wherein R 1 and R 2 are independently of each other a C 1 -C 25 alkyl group which can optionally be interrupted by one or more oxygen atoms, an allyl group which can optionally be substituted one to three times with C 1 -C 4 alkyl, a cycloalkyl group which can be optionally substituted one to three times with C 1 -C 8 alkyl or C 1 -C 8 alkoxy, a cycloalkyl group which can optionally be condensed one or two times by phenyl which phenyl can optionally be substituted one to three times with C 1 -C 4 -alkyl, halogen, nitro or cyano, an alkenyl group, a cycloalkenyl group, an alkynyl group; a C 1 -C 25 alkyl group, an alkenyl group or an alkynyl group substituted partially or wholly by halogen, an aldehyde group, an ester group, a carbamoyl group, a ketone group, a silyl group, a siloxanyl group, aryl, heteroaryl, a group —CR 3 R 4 —(CH 2 ) g —aryl or a group —CR 3 R 4 —(CH 2 ) g —heteroaryl, wherein R 3 and R 4 independently from each other stand for hydrogen, fluorine, cyano or C 1 -C 4 alkyl which can be substituted by fluorine, chlorine or bromine, or phenyl which can be substituted one to three times with C 1 -C 4 alkyl, and g stands for 0, 1, 2, 3 or 4, Ar 1 and Ar 2 are independently of each other wherein R 6′ is hydrogen, C 1 -C 18 alkyl, or C 1 -C 18 alkoxy and R 38 stands for hydrogen, C 6 -C 10 aryl, C 7 -C 12 alkylaryl, C 7 -C 12 aralkyl, or C 1 -C 8 -alkyl.