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:
Jul. 07, 1998
Filed:
Mar. 04, 1997
Bryan Thomas, Barry, GB;
Dow Corning Limited, Barry, GB;
Abstract
A method for preparing an aqueous gypsum mixture having hydrophobic additive substantially uniformly dispersed therein, which method comprises admixing in water gypsum, a silane of the general formula (RO).sub.3 SiR' or the general formula (RO).sub.2 SiRR' and non-emulsified polysiloxane of the general formula; ##STR1## wherein each R is the same or different and represents a hydrocarbon group having from one to eight carbon atoms, R' represents a lower alkyl group which is optionally substituted by an amino, amino-loweralkylene-amino or dialkylenetriamine group, and a has an average value of between 20 and 200. The silane is preferably N-(2-aminoethyl)-3-aminopropyltrimethoxysilane and the polysiloxane preferably trimethyl end-blocked linear methylhydrogen polysiloxane. The method may further include adding surfactant. Also disclosed is a gypsum product which includes gypsum mixture prepared according to the above method.