| 摘要 |
PURPOSE:To provide a titled compsn. having a wide curing temp. range and an excellent thermal collapsing property by incorporating a polyhydric isocyanate compd. and a copolymer of a styrene monomer and a hydroxyl group-contg. (meth)acrylate monomer therein. CONSTITUTION:This compsn. for binding molding sand is formed by contg. a polyhydric isocyanate compd. or block isocyanate compd. as a hardener and contg. the following copolymer: This is the copolymer of the styrene monomer expressed by the formula I (R1 is H or methyl, R2 is alkyl of C1-3, X is OH or alkoxy, m and n are 0 or 1-5) and the hydroxyl group-contg. (meth)acrylate monomer expressed by the formula II (R1 is H or methyl, Y is a residual ester group having OH). This compsn. is curable quickly at temp. over a wide range from an ordinary temp. to a high temp., has high strength in the stage of molding and has an excellent thermal collapsing property. |
