Resin composition for bonding foundry sand

Abstract

A crystalline unsaturated polyester composition for binding foundry sand, said composition comprising: (A) 100 parts by weight of an unsaturated polyester resin which is a mixture of 100 parts by weight of a normally solid, substantially tack-free, crystalline unsaturated polyester and 0 to 50 parts by weight of an unsaturated prepolymer or monomer copolymerizable with said unsaturated polyester or both, and (B) 0.1 to 10 parts by weight of a mixture of at least two of (1) a radical polymerization catalyst which requires a temperature of at least 70.degree. C. but below 90.degree. C. to obtain a half-period value of 10 hours, (2) a radical polymerization catalyst which requires a temperature of at least 90.degree. C. but below 110.degree. C. to obtain a half-period value of 10 hours and (3) a radical polymerization catalyst which requires a temperature of at least 110.degree. C. but not exceeding 130.degree. C. to obtain a half-period value of 10 hours.

Dependencies are inferred from the claim text.