Fire resistant gypsum board and related methods
US11834375B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 22, 2021 |
| Grant date | Dec 5, 2023 |
| Priority date | — |
| Expiry date | Jul 5, 2041 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B2111/34
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Disclosed are a composite gypsum board and a method of preparing composite gypsum board. The board contains a set gypsum core sandwiched between two cover sheets. The core is formed from a slurry containing stucco, water, and optional ingredients such as foaming agent, accelerator, retarder, polyphosphate, starch, and dispersant, and core intumescent material. The board also contains at least one skim coat and/or hard edges. A face skim coat layer can be included on one side of the core, facing a face cover sheet. A back skim coat layer can be included on the other side of the core, facing a back cover sheet. Hard edges are known in the art and can be formed, e.g., continuously from a stucco slurry for forming the face and/or back skim coats. Preferably, the back skim coat layer and/or the hard edges are formed from a slurry containing stucco, water, skim coat or edge intumescent material (which have the same desired characteristics), and other optional additives as desired. The skim coat or edge intumescent material can be composed of the same material as the core intumescent material, if desired, but the skim coat and/or edge intumescent material is present in a higher relative c…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.