Intumescent silicates having improved stability
US4521333A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 3, 1984 |
| Grant date | Jun 4, 1985 |
| Priority date | — |
| Expiry date | May 3, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S521/907
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A fire retardant, intumescent composition is provided which comprises a mixture of alkali metal silicate, represented by the formula M.sub.2 O:xSiO.sub.2 in which M is the alkali metal; an oxy boron compound selected from boric acid or salts of Group I and II elements; and water; in which the weight ratio x ranges from about 1.5 to about 4, the molar ratio of boron to M is between 0.2 and 0.9, and the water comprises about 5 to 15 weight percent of the total composition. These compositions are made by mixing an alkali metal silicate sol with a borate (e.g., boric acid) to form a gel which is dried in an oven. The resulting residue is crumbled to granules. A fire retardant which is relatively insoluble and has improved stability to long term exposure to water and humidity is formed. Various parameters (e.g., the weight ratio x, the amount of water present, and the ratio of boron to sodium) can be adjusted to control the amount of intumescence retained after exposure to water and also to control the temperature of intumescence. Granules made of these compositions have many applications, including incorporation into asphalt roofing materials.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.