Process for Manufacturing Wallboard and the Like.
U S Pat 3 929 947 1975 Dec; :
A lightweight wallboard may be manufactured by melting a batch of sulfur at 130 deg-155 deg c, adding small amounts of viscosity- increasing agents and inert materials, and then rapidly mixing a quantity of gypsum, part of whose water content vaporizes at the molten sulfur temperature to produce a stable foamed material that is molded under pressure between sheets of paper or other covering material to the desired thickness. Thus, a typical composition to produce a batch of the wallboard may contain s 200, gypsum 5.5, P2s5 6, styrene 6, and talc 15 weight parts.
U.S. Pat. 3,929,947; Dec. 30, 1975; Chem. Abstr. 84:P126,053x