United States Gypsum Company

Usg Interiors, Inc.

Runhai Lu

Michael Patrick Shake

David R Blackburn

Weixin David Song

Alfred C Li

Qingxia Liu

James Wittbold

Yijun Sang

Mark H Englert

Chris C Lee

Bruce Lynn Petersen

Sharon Louise Tracy

John L Fall

Qinghua Li

Mark K Hemphill

Guy Rosenthal

Terry L Rosenstiel

Adelaida L Carbo

Salvatore Immordino

Charles W Cochran

Renee J Weinberger

Matthew T Langdon

Jim Thulin

Guy L Rosenthal

James R Wittbold

James C Thulin

Sharon L Tracy

Chris Lee

Gypsum boards formed from synthetic gypsum and other gypsum sources having high chloride salt concentrations. Gypsum boards may include a board core including set gypsum. A total concentration of the chloride anion in the board core ranges from about 500 ppm to about 3000 ppm, typically about 1000 ppm to about 3000 ppm, based on weight of the calcium sulfate hemihydrate. An inner surface of a front paper cover sheet contacts a first face of the board core. An inner surface of a back paper cover sheet contacts a second face of the board core. A starch layer coats the inner surface of at least one of the front and back cover sheet. Methods of making the gypsum board, and a wall system for employing the gypsum boards, are also provided.

Gypsum board from gypsum having high level of chloride salt and a starch layer and methods associated therewith

Provided herein is a joint compound having a composition to allow tools to easily clean up, comprising water, at least one inert filler, and a binder comprising a sulfonated starch, and a method of preparing the joint compound.

Joint compound with sulfonated starch

A modified gypsum set accelerator and a method of preparing the same is provided, which includes dry loose finely ground particles of a mixture of ground dry calcium sulfate dihydrate and a grinding aid selected from one or more of beta-naphthalene sulfonate formaldehyde condensate, trimetaphosphate phosphate salt, tripolyphosphate salt, tetra-pyrophosphate salt, and pregelatinized starch.

Gypsum set accelerator and method of preparing same

A coating for application to the surface of an interior building product comprises: a resin formulation such as a melamine formaldehyde resin characterized by its ability to strengthen the interior building product when applied as a coating to the building product; and an aldehyde scavenger selected from the group consisting of; tetraethylene pentamine, propionamide, caprolactam, ammonium hydroxide, sodium bisulfate, sodium metabisulfite, ammonium primary phosphate, ammonium secondary phosphate, a combination of ammonium primary phosphate and ammonium secondary phosphate, a combination of ammonium primary phosphate, ammonium secondary phosphate and a sulfite, a polyvinyl alcohol; adipic dihydrazide and a combination of a polyvinyl alcohol and adipic dihydrazide.

Use of aldehyde scavengers in interior building products

Effective use of dispersants in wallboard containing foam results from a method where stucco is mixed with a first dispersant and a first quantity of water to form a gypsum slurry. A soap is blended with a second dispersant and a second quantity of water to make a foam. Subsequently, the foam is combined with the slurry. Choice of different first and second dispersants and their relative amounts allows control of the size distribution of the foam bubbles in the slurry and the resulting voids in the gypsum core. Melamine sulfonate condensate and polycarboxylate dispersants are preferred dispersants.

Effective use of melamine sulfonate condensate dispersants in wallboard containing foam

The invention, provides a curable, formaldehyde free coating composition comprising a composition comprising a polyacid copolymer crosslinked with a hydroxyl group-containing compound and calcium aluminosilicate powder, panels coated with the coating composition, and a method of coating a panel with the coating composition.

Formaldehyde free coatings for panels

An acoustical panel is made by applying a thin, acoustically-transparent coating to an acoustical base mat. A pulp is made from one or more fillers, a fibrous filler, a binder and water. A thickener solution is prepared from a thickener and water. A portion of the pulp and the thickener solution are mixed under high shear conditions to degrade the fibrous filler and form a smooth coating. The coating is applied to and distributed over a base mat and the coated base mat is then cut and dried to form a coated acoustical panel. The panel is free of visible mineral nodules on the surface of the coating. Optionally, the pulp is a portion of a pulp used to make the base mat. Other embodiments include the use of recycled dust or fine particles of the acoustical panel obtained from cutting or shaping the base mat or coated panels.

Method of making a coating and a coated acoustical panel using degraded fibers

A gypsum slurry is described that includes water, a hydraulic component comprising at least 50% calcined gypsum by weight based on the dry weight of the hydraulic component, foam, a defoamer and a polycarboxylate dispersant. In some embodiments of the invention, the defoamer is combined with the dispersant prior to being added to the gypsum slurry. The defoamer and dispersant can be added as a physical mixture, wherein the defoamer is attached onto the dispersant polymer, or a combination thereof. A gypsum building panel is made from the gypsum slurry.

Foamed slurry and building panel made therefrom

A gypsum slurry is described that includes water, a hydraulic component comprising at least 50% calcined gypsum by weight based on the dry weight of the hydraulic component, foam, a defoamer and a polycarboxylate dispersant. In some embodiments of the invention, the defoamer is combined with the dispersant prior to being added to the gypsum slurry. The defoamer and dispersant can be added as a physical mixture, wherein the defoamer is attached onto the dispersant polymer, or a combination thereof. In some embodiments, a gypsum building panel is made from the gypsum slurry.

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Wauconda, IL, United States of America

Runhai Lu