PURPOSE: To obtain a polymerizable composition which is low in a curing shrinkage and can give a cured article which is flexible and excellent in rubbery elasticity, by mixing a mono(meth)acrylate with methacrylic acid and a radical polymerization catalyst.
CONSTITUTION: A composition formed by mixing 100pts.wt. mono(meth)acrylate (A) of a number-average MW ≥300 with 1W30pts.wt. methacrylic acid (B), 0.1W10pts.wt. radical polymerization catalyst (C), 0W5pts.wt. silane coupling agent (D) and 0W50pts.wt. nonreactive plasticizer (E). A desirable mono(meth) acrylate is a polyether mono(meth)acrylate or a urethane group-containing mono(meth)acrylate. The radical polymerization catalyst is used, for example, in such a way that a heat polymerization initiator for heat polymerization or both of a peroxide and a reducing agent for redox polymerization are added just before curing. When a photopolymerization system is adopted, a photoinitiator is used.
FUKUTAKA EITARO
UKITA KENKICHI
