Polyol resin binder compositions and process

Claim 1

A process for preparing self-curing coated aggregate product comprising mixing together to form a homogeneous admixture (I) a foundry aggregate containing sand as its major component (II) from about 0.1 percent to about 10 percent by weight, based upon the weight of the aggregate used, of a resin binder composition containing an admixture of polyhydroxy polyols with a substantial portion of the polyols containing ether linkages, said polyhydroxy polyols comprising a mixture of (a) from about 90 to about 15 percent by weight, based upon the total weight of said resin binder, of a phenolic-based alkoxy polyol having repeating units of the general formula ##STR4## wherein X is CH 2 or H and the CH 2 group may be in the ortho, meta or para position or mixtures thereof, N is an integer greater than one, and R represents an aliphatic carbinol radical having from 2 to 4 carbon atoms; and (b) from about 10 to about 85 percent by weight, based upon the total weight of said resin binder, of an admixture of a tertiary hydroxy diamine polyol of the general formula ##STR5## and a tertiary alkoxy hydroxy amine polyol of the general formula ##STR6## wherein R represents an aliphatic carbinol radical having 2 to 4 carbon atoms, and (III) from about 40 percent to about 60 percent of a polyisocyanate based upon the total weight of component (II), whereby said admixture of said resin binder composition reacts with said polyisocyanate to form on said foundry aggregate a self-curing polyurethane coating.