Patent ID: 11891336
Assignee: UNITED STATES GYPSUM COMPANY
Field: Materials, metallurgy (Chemistry)
Classification: CPC C  B  E | IPC B  C  E

Claim 0:
1. A gypsum board comprising a set gypsum core disposed between a face cover sheet and a back cover sheet, the set gypsum core formed from a slurry comprising water, stucco, and a high salt impurity content comprising at least about 150 ppm chloride anion per 1,000,000 parts by weight of stucco, the back cover sheet comprising paper having a bond side Cobb value of at least about 2.1 g/100 cm2 according to the Cobb test, the paper having a basis weight of from about 35 lb/msf to about 65 lb/msf, and the paper having a thickness of about 0.005 inch to about 0.015 inch, wherein the paper allows for a superior bond between the board core and the back cover sheet as compared with the board prepared with the back cover sheet comprising paper having a bond side Cobb value below 2.1 g/100 cm2.