Patent ID: 8193286

Claim:
A method of producing a star polymer, the method comprising: anionically polymerizing, in the presence of an anionic polymerization initiator and lithium chloride to synthesize an arm polymer, a (meth)acrylic ester represented by formula (II): where: R 4 represents a hydrogen atom or a methyl group; and R 5 represents an organic group; reacting the arm polymer with a polyacrylate that has at least two partial structures represented by formula (I): where: R 1 represents a hydrogen atom or a methyl group; R 2 and R 3 each independently represents an organic group that is directly bound to C1 via a carbon-carbon bond; and C1 represents a carbon atom that is directly bound to a moiety via a carbon-carbon bond; wherein: the anionic polymerization initiator is ethyllithium, n-butyllithium, sec-butyllithium, or tert-butyllithium; a homopolymer chain haying a repeating unit derived from the (meth)acrylic ester in which R 5 is a C1-C4 alkyl group is excluded as the arm polymer when R 1 in formula (I) is a methyl group; a ratio of a weight average molecular weight of the star polymer to a number average molecular weight of the star polymer is from 1.00 to 1.27; and wherein a temperature is maintained at from −40° C. to 40° C.