Method of polymerizing hydroxyl endblocked polydiorganosiloxane using quaternary ammonium carboxylate-carboxylic acid catalyst
US4486567A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 1983 |
| Grant date | Dec 4, 1984 |
| Priority date | — |
| Expiry date | Mar 14, 2003 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08K5/19
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Hydroxyl-endblocked polydiorganosiloxane oligomer is polymerized through the use of a catalyst mixture of quaternary ammonium carboxylate and carboxylic acid. The method heats the mixture of oligomer and catalyst to a temperature in the range of from 90.degree. C. to 150.degree. C., removing water from the mixture, until the desired degree of condensation is achieved. When cooled, the product is a stable polydiorganosiloxane of increased molecular weight. The catalyst can be inactivated by heating and removing volatile byproducts. One embodiment of the method adds an acidic or neutral reinforcing filler to the mixture before polymerization to yield a storage stable silicone polymer-filler mixture which is useful in a manner similar to conventionally produced silicone polymer-filler mixtures.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.