RESIN COMPOSITION FOR BONDING FOUNDRY SAND

摘要

Crystalline unsaturated ester compound for bonding foundry sand is prepared from copolymerization of inviscid solid crystalline unsaturated polyesters (I) and prepolymer or monomer (II). Weight ratio of Iand II in reaction mixture is 100 and 0-50, respectively. This resin (III) is blended with more than 2 kinds of polymerization catalysts, which require different temp. conditions for 10 hr half-life: radical catalyst of 70-90≦̸C, 90-110≦̸C and 110-130≦̸C condition. Weight ratio of III and catalyst mixture is 100 and 0.1-10, respectively. I can be prepared from material having symmetric molecular structure.