High starch light weight gypsum wallboard

摘要

A light weight gypsum board comprising: a set gypsum composition disposed between two paper cover sheets, the set gypsum composition formed from at least water, stucco, pregelatinized starch, and a naphthalenesulfonate dispersant; the pregelatinized starch is in an amount from about 0.5% to about 10% by weight based on the weight of the stucco; and (i) the naphthalenesulfonate dispersant is in an amount from about 0.25% to about 2.0% by weight based on the weight of the stucco; (ii) the naphthalenesulfonate dispersant is in the form of an aqueous solution containing from about 40% to about 45% by weight naphthalenesulfonate and the aqueous solution is in an amount from about 0.5% to about 2.5% by weight based on the weight of the stucco; (iii) at a board thickness of about '/2 inch (about 1.3 cm), the board has a dry weight from about 1000 lb/MSF (about 5 kg/SQM) to about 1400 lb/MSF (about 6.8 kg/SQM); or (iv) any combination of (i) - (iii). 3SIRS .1 (GHMalters) P74627.AU.1