Modified landplaster as a wallboard filler
US7601214B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 20, 2006 |
| Grant date | Oct 13, 2009 |
| Priority date | — |
| Expiry date | May 15, 2027 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2993
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A gypsum slurry includes calcium sulfate hemihydrate, water and calcium sulfate dihydrate is coated with a hydrophilic, dispersible coating. The coating is less soluble than the calcium sulfate hemihydrate to delay exposure of the landplaster to the remainder of the slurry, preventing premature crystallization and the early stiffening that accompanies it.Another embodiment is a gypsum slurry that includes calcium sulfate hemihydrate, a polycarboxylate dispersant, water and coated calcium sulfate dihydrate. In this case, the hydrophilic, dispersible coating is selected to serve as a modifier to enhance the ability of the dispersant to fluidize the gypsum slurry.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.