The process according to claim 22, wherein a monomer represented by the following general formula (4) is admixed in said step (a) wherein R3 and R4 is, respectively, H or an alkyl group of 2 or less carbon atoms, and B is a group having at least a polar group selected from the group consisting of a polyether group, a cyano group, an amino group, an amide group and a carbonate group. 38.