Method for the preparation of an organopolysiloxane
US4722987A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 14, 1986 |
| Grant date | Feb 2, 1988 |
| Priority date | — |
| Expiry date | Aug 14, 2006 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G77/32
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
An oligomer or a mixture of organopolysiloxane oligomers is polymerized in the presence of a strong acid, e.g. trifluoromethane sulfonic acid, as the catalyst to give an organopolysiloxane containing a considerable amount of silanolic hydroxy groups at the molecular chain ends. Thereafter, the mixture is admixed with water and a hexaorganodisilazane or triorganosilyl amine compound in combination so as to neutralize the acid catalyst by the ammonia produced by the hydrolysis of the disilazane or silyl amine compound with simultaneous silylation of the terminal hydroxy groups. Thus, the organopolysiloxane contains a greatly decreased amount of the residual silanolic hydroxy groups at the molecular chain ends to be imparted with remarkably improved heat stability.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.