Process for producing low molecular weight, hydroxy functional (meth)acrylate polymers, their use for producing isocyanate terminal group-containing prepolymers as well as sealants and adhesives produced therefrom

Abstract From the Canadian patent

Low molecular weight (meth)acrylate polymers with substantially .alpha..omega. -terminal hydroxyl groups with a hydroxyl group equivalent weight of 500 to 5000 are obtained by the polymerization of (meth)acrylates and optionally copolymerizable monomers in the presence of an initiator able to transfer hydroxyl groups to the polymer molecule and regulators of general formula HO-A-Sx-B-OH, in which A and B in each case stand for a divalent organic radical and x ? 2. By reacting with diisocyanates, the hydroxyfunctional (meth)acrylate polymers yield terminal isocyanate groups containing prepolymers, from which can be produced moisture-hardening adhesives and sealants, which are preferably …