Patent ID: 8476379

Claim:
A silphenylene skeleton-containing silicone type polymer comprising a repeating unit represented by the following general formula (1) and having a weight average molecular weight of 5,000 to 40,000, wherein R 1 to R 4 are each a monovalent hydrocarbon group having 1 to 12 carbon atoms and may be the same or different from each other; k is an integer of 1 to 100; a and b are each 0 or a positive number, and c and d are each a positive number, and they satisfy 0<(c+d)/(a+b+c+d)≦1.0; X is a divalent organic group represented by the following general formula (2); and Y is a divalent organic group represented by the following general formula (3), wherein Z and W are each a divalent organic group selected from groups represented by the following formulae; m and p are each 0 or 1; n is 0, 1 or 2; R 5 and R 6 are each an alkyl or alkoxyl group having 1 to 4 carbon atoms and may be the same or different from each other; and R 7 to R 10 are each a hydrogen atom or a carboxyl-containing organic group and may be the same or different from each other, wherein at least one of R 7 to R 10 is a carboxyl-containing organic group.