Patent ID: 8809470

Claim:
An anionic polymerizable composition consisting of an epoxy compound and an anionic polymerization initiator for anionically polymerizing the epoxy compound to form a cured polymer of the epoxy compound, wherein said initiator consists of a potassium salt or a sodium salt of at least one acid selected from the group consisting of lauric acid, n-caprylic acid, cyclohexanecarboxylic acid, 3-cyclohexylpropionic acid, versatic acid and 2-ethylhexanoic acid, and wherein said epoxy compound is a di- or more functional epoxy resin having at least one member selected from the group consisting of a glycidyloxy group, glycidylamino group and 3,4-epoxycyclohexenyl group, whereby the cured epoxy polymer has a maximum value of loss tangent of 0.1 or less at 300° C. or less at 1 Hz.