SOLID PARTICLE DISPERSING APPARATUS

1,163,342. Filled polyurethanes. MOBAY CHEMICAL CO. 16 May, 1967 [24 May, 1966], No. 22793/67. Headings C3C and C3R. Polyurethanes having discrete particles of a solid therein are prepared by sprinkling solid particles into a liquid organic compound containing hydrogen atoms reactive with an organic polyisocyanate while the liquid is being stirred to form a slurry, subjecting the slurry to a shearing action to break agglomerates of solid therein into discrete particles, flowing the slurry in a thin film to allow entrapped air bubbles to escape, diluting the resulting slurry with additional liquid organic compound and thereafter mixing the resulting dispersion with an organic polyisocyanate. The product may be in cellular form in which case a blowing agent is incorporated into the additional liquid organic compound. The particles may be of zirconium silicate, gypsum, limestone, chalk, talc, silica, zirconium oxide, silicon oxide mixtures, calcium carbonate, carbon and opal fines, clay and especially barium sulphate and are preferably preset in amounts of from 15 to 4 parts per part of the reactive hydrogen containing compound in the initial slurry. The reactive hydrogen containing compounds are preferably those having a M.W. of at least 200, those specifically exemplified being a condensation product of glycerine and propylene oxide and of hexanetriol-1,2,6 and propylene oxide. Conventional blowing agents, emulsifiers, silicone oil stabilizers, and catalysts such as tertiary amines and/or organometallic compounds may be used in the production of the polyurethanes.