PURPOSE: To obtain an unsaturated polyester resin exhibiting a low molding shrinkage factor and capable of preventing generation of a crack during molding without adding a low profile additive and of producing a molding excellent in surface smoothness.
CONSTITUTION: This is an unsaturated polyester resin (c) prepared by dissolving an unsaturated polyester (a) synthesized by dehydration condensation of an unsaturated dibasic acid, a saturated divalent acid and a polyvalent alcohol in a polymerizable monomer (b). 2,2-Bis(4-hydroxycyclohexyl)propane is used for synthesis of the unsaturated polyester (a) in an amount of 25 to 55wt.% based on the total amount of the unsaturated dibasic acid, a saturated dibasic acid and a polyvalent alcohol and the weight ratio of the dissolved unsaturated polyester (a) to the polymerizable monomer (b) is = 50/50 to 80/20.
OKUMA HIDEO
ISHIKURA YOSHITO
