Gypsum mixture containing hydrophobic additive and method for hydrophobing gysum
US5855667A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 16, 1997 |
| Grant date | Jan 5, 1999 |
| Priority date | — |
| Expiry date | Jul 16, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B2103/65
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A gypsum mixture is disclosed which has hydrophobic additive substantially uniformly dispersed therein and which comprises gypsum, a first silane of the general formula (RO).sub.3 SiR or of the general formula (RO).sub.2 SiR.sub.2, and a second silane of the general formula (RO).sub.3 SiR' or of the general formula (RO).sub.2 SiRR', wherein each R is the same or different and represents a lower alkyl group, and R' represents a lower alkyl group which is substituted by a substituent selected from an amino, amino-lower alkyl-amino or dialkylenetriamine group. Preferably, the first silane is methyltrimethoxysilane and the second silane is N-(2-aminoethyl)-3-aminopropyltrimethoxysilane. Also disclosed is a method for preparing said gypsum mixture.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.