Process for making silanol stopped oligomeric materials
US6433204B1 · kind B1 · utility
1Cited by
5References
20Claims
0Family size
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Key dates
| Filing date | Jan 23, 2002 |
| Grant date | Aug 13, 2002 |
| Priority date | — |
| Expiry date | Jan 23, 2022 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07F7/0876
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for the production of linear silanol stopped siloxanes comprising: a) conducting a ring opening polymerization of a hexaorganocyclotrisiloxane having the formula:D3=(R1R2SiO)3where R1 and R2 are independently selected from the group of one to forty carbon atom monovalent radicals, in a solvent comprising a mixture of water and a volatile polar aprotic organic solvent in the presence of catalytic amounts of a strong base; b) neutralizing the catalytic amount of the strong base with a partially neutralized salt of a polybasic acid wherein the pH ranges from about 6 to about 8; and c) washing with water.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.