MOULD MATERIAL BINDING AGENT SYSTEM WHICH COLD-HARDENS WITH RMATION OF POLYURETHANE

摘要

A moulding binder system for prodn. of foundry moulds contains (a) a soln. of a phenolic polyol with at least 2 OH gps., and (b) a polyisocyanate with at least 2 NCO gps., opt. also as a soln., and contg. a chlorosilane. The components react to form a cold-hardening binder. Pref. amt. of chlorosilane is 0.01-2 wt.% w.r.t. polyisocyanate. A tri- and/or tetra-chlorosilane may be used. Pref. cpds. have formula SiRxHyCl4-(x+y) or SiRnCl4-n. R = 1-6C aliphatic gp., or (substd.) phenyl; x = 1 and y = 2; or y = 2 and x = 1; n = 1-3. Claimed additives are trimethylchlorosilane, dimethyldichloro-silane, methyltrichlorosilane, tetrachlorosilane, diethylchloro-silane, vinyltrichlorosilane and/or diphenyldichlorosilane.