Continuous process for producing a silicone polymer
US6221993A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 26, 1999 |
| Grant date | Apr 24, 2001 |
| Priority date | — |
| Expiry date | Aug 26, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G77/08
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A continuous process for producing a silicone polymer comprises the sequential steps of (i) polymerisation of a linear silanol group containing siloxane by condensation polymerisation, or of a cyclosiloxane by ring opening polymerisation, or of a mixture of said linear and cyclosiloxanes with a phosphazene base in the presence of water and the presence or absence of a filler in an extruder, (ii) neutralising the reaction mixture in an extruder, and (iii) stripping the neutralised reaction mixture to remove volatile materials. Preferably, step (iii) is performed in an extruder, more preferably steps (i), (ii) and (iii) are all performed in the same extruder.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.