Methacrylic acid ester polymer, a method of manufacturing, the active energy ray curable composition and optical recording medium

摘要

Containing an acid value of not more than 50mgKOH / g, and a methacrylic acid ester polymer transition metal content is 1ppm or less, at least 80 mol% of the polymer having terminal double bond structure of the formula (1) methacrylic acid ester polymer to be: (1) (In the formula (1), R is an alkyl group, a cycloalkyl group or an aryl group.) With an active energy ray-curable resin composition using the warp is small and, that the hardness to obtain a high cured it can.