DISPERSANT AND FOAMING AGENT COMPRISING NAPHTHALENE SULFONATE AND ALDEHYDE CONDENSATE

摘要

The present invention provides a dispersant and foaming agent combination th at is useful in the production of gypsum wallboard and other aqueous cementitio us 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 accordin g to the invention exhibits a higher nail pull value than gypsum wallboard formed using a conventional dispersant and a foaming agent at the same solid s loading ratio.