Patent ID: 7998657

Claim:
A polymer comprising at least recurring units derived from a polymerizable ester compound having any one of the following general formulae (1) to (4): wherein A 1 is a polymerizable functional group having a carbon-carbon double bond, A 2 is an oxygen atom, methylene or ethylene group, R 1 is each independently a straight, branched to or cyclic monovalent hydrocarbon group of 1 to 10 carbon atoms, R 2 is each independently a hydrogen atom or a straight, branched or cyclic monovalent hydrocarbon group of 1 to 10 carbon atoms, or a combination of R 1 , a combination of R 2 , or a combination of R 1 and R 2 may bond together to form an aliphatic hydrocarbon ring with some carbon atoms in the oxygen heterocycle to which they are attached, and in that event, each of R 1 and R 2 is a straight, branched or cyclic alkylene group of 1 to 10 carbon atoms, R 3 is each independently a straight, branched or cyclic monovalent hydrocarbon group of 1 to 10 carbon atoms, or a combination of R 3 may bond together to form an aliphatic hydrocarbon ring with some carbon atoms in the ring to which they are attached, and in that event, each of R 3 is a straight, branched or cyclic alkylene group of 1 to 10 carbon atoms, and n is an integer of 0 to 6, and having a weight average molecular weight of 2,000 to 100,000.