Patent ID: 7423102
Filing Date: 2008-09-09
Classification: C08F,C08L,G03F

Abstract:
1. A star polymer which comprises a central core and three or more branches bonded to the central core, and has a weight average molecular weight of from 1,000 to 100,000, wherein at least one of the branches containing at least one repeating unit selected from the group consisting of the following repeating units of the formulae (1), (2), (3), (4) and (9); the formula (1) wherein R 1 represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a fluoroalkyl group having 1 to 4 carbon atoms, R R m is an integer of 1 to 3 and when m is 2 or 3, each of the group of the formula —(OC(OR the formula (2) R 31 represents a hydrocarbon group having 1 to 20 carbon atoms or a group of the formula —CH(R 33 )—OR 34 , u is an integer of 0 to 2, —CH 2 — in R 31 not linked to the oxygen adjacent to R 31 may be substituted by —COO— or —O—, and at least one hydrogen atom in R 31 may be substituted by a hydroxyl group, a cyano group, a halogen atom or an alkoxy group, R R in the divalent aliphatic hydrocarbon group, —CH R R R R P the formula (3) wherein R 31 has the same meaning as defined above, the formula (4) wherein R 31 has the same meaning as defined above, the formula (9) wherein Y represents an oxygen atom or —NH—, and the central core is a structural unit of the formula (I) wherein (W) represents a polyvalent aromatic hydrocarbon group, a polyvalent saturated cyclic hydrocarbon group, a polyvalent saturated acyclic hydrocarbon group or a group combined by at least two of the polyvalent aromatic hydrocarbon group, the polyvalent saturated cyclic hydrocarbon group and the polyvalent saturated acyclic hydrocarbon group, wherein at least one —CH 2 — in the polyvalent saturated cyclic hydrocarbon group and the polyvalent saturated acyclic hydrocarbon group not linked to Q may optionally be substituted by —O—, —S—, —NR 52 — or —SiR 53 2 — and at least one hydrogen atom in the polyvalent aromatic hydrocarbon group and the polyvalent saturated cyclic hydrocarbon group may optionally be substituted by an alkyl group having 1 to 6 carbon atoms, R 52 and R 53 each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, Q represents —O—, —S— or —NR 54 —, wherein R 54 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R 50 and R 51 each independently represents an alkyl group having 1 to 6 carbon atoms, an alkylalkoxy group having 2 to 6 carbon atoms or a cycloalkyl group having 3 to 12 carbon atoms, or R 50 and R 51 link together and represent a divalent saturated aliphatic hydrocarbon group which bonds to form a divalent cyclic hydrocarbon group together with a carbon atom adjacent to R 50 and R 51 , and 1 represents an integer of 3 to 12.