The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 31, 2020
Filed:
Nov. 01, 2016
United States Gypsum Company, Chicago, IL (US);
Qinghua Li, Rolling Meadows, IL (US);
Naveen Punati, Arlington Heights, IL (US);
Mark Antosh, Grayslake, IL (US);
Weixin D. Song, Vernon Hills, IL (US);
United States Gypsum Company, Chicago, IL (US);
Abstract
Disclosed are a gypsum board, and related slurries and methods. The gypsum board comprises a gypsum layer disposed between two cover sheets. The gypsum layer comprises a crystalline matrix of set gypsum and expandable graphite. The expandable graphite exhibits volume expansion at high temperatures. Optionally, unexpanded vermiculite can also be included in the gypsum layer to provide an expansion component at even higher temperatures. Because of synergy between the expandable graphite and unexpanded vermiculite in accordance with some embodiments, less vermiculite can be included in the board than in conventional board that contained vermiculite. The board desirably can pass one or more fire-related tests, and is a fire-rated board in some embodiments.