Method of making wallboard
US6929875B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 5, 2003 |
| Grant date | Aug 16, 2005 |
| Priority date | — |
| Expiry date | Dec 27, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S516/909
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The present invention provides a dispersant and foaming agent combination that is useful in the production of gypsum wallboard and other aqueous cementitious products, a method of forming a gypsum wallboard and a gypsum wallboard. The dispersant in the combination according to the invention is a naphthalene sulfonate-aldehyde condensate alkali salt polymer having a weight average molecular weight of from about 17,000 to about 47,000. The alkali is preferably an alkali metal and/or an alkaline earth metal. The aldehyde is preferably formaldehyde. The foaming agent used in the combination according to the invention is a soap, preferably an alkali salt of an alkyl ether sulfate and/or an alkyl sulfate. The combination of a high molecular weight dispersant and a foaming agent produces a gypsum wallboard core effect that more efficiently entrains air (i.e., creates void space), thereby lowering overall board weight without detrimentally affecting strength. A gypsum wallboard formed using the dispersant and foaming agent combination according to the invention exhibits a higher nail pull value than gypsum wallboard formed using a conventional dispersant and a foaming agent at the same sol…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.