检索国际和国家专利汇编

1. (WO2008042060) COMPOSITE LIGHT WEIGHT GYPSUM WALLBOARD

Pub. No.:    WO/2008/042060    International Application No.:    PCT/US2007/018978
Publication Date: 2008-4-10 International Filing Date: 2007-8-29
IPC: B32B 13/00
B32B 13/02
Applicants: UNITED STATES GYPSUM COMPANY
Inventors: YU, Qiang
SONG, Weixin, David
Title: COMPOSITE LIGHT WEIGHT GYPSUM WALLBOARD
Abstract:
The invention provides a lightweight composite gypsum board including a foamed low density set gypsum core, a top non-foamed (or reduced foamed) bonding high density layer and a bottom non-foamed (or reduced-foamed) bonding high density layer, a top cover sheet bonded to the foamed low density set gypsum core by the top non-foamed (or reduced-foamed) bonding high density layer, and a bottom cover sheet bonded to the foamed low density set gypsum core by the bottom non-foamed (or reduced-foamed) bonding high density layer. The foamed gypsum core and the non-foamed (or reduced-foamed) bonding layers are made from a gypsum slurry including stucco, pregelatinized starch, and preferably a naphthalenesulfonate dispersant and sodium trimetaphosphate. The foamed gypsum core has a density of less than about 30 pcf using soap foam in the gypsum-containing slurry. The gypsum board is lightweight with high strength. A method of making the gypsum board is also provided.