United States Gypsum Company

Mark Antosh

Weixin David Song

Yijun Sang

Qinghua Li

Mark K Hemphill

Suman Sinha Ray

Naveen Punati

A layered gypsum wallboard can include: a gypsum board having opposing front and back faces, wherein the gypsum board comprises a first cover sheet material at the front face, a second cover sheet material at the back face, and a gypsum core layer comprising gypsum; an adhesive layer on the second cover sheet material of the gypsum board, the adhesive including a polymer having a glass transition temperature (T) of &#x2212;10&#xb0; C. to 30&#xb0; C.; an intermediate gypsum layer including gypsum on the adhesive layer such that the adhesive layer is between the second cover sheet material and the intermediate gypsum layer, wherein the adhesive layer and the intermediate gypsum layer have a combined thickness of 0.09 inches to 0.25 inches; and a third cover sheet material, wherein the intermediate gypsum layer is between and in contact with the adhesive layer and the third cover sheet material.

Methods for making high sound transmission class gypsum boards and gypsum boards made by the method

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.

Fire resistant gypsum board comprising expandable graphite and related methods and slurries

Growing community of inventors

Arlington Heights, IL, United States of America

Mark Antosh