Vacuum process for the manufacture of siloxane-oxyalkylene copolymers
US5869727A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 8, 1997 |
| Grant date | Feb 9, 1999 |
| Priority date | — |
| Expiry date | Aug 8, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G77/46
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Disclosed is an improved process for the manufacture of silicone containing copolymers via a hydrosilation reaction, in which the catalyzed reaction of organohydrosiloxane and olefinic polyether is carried out at between 20.degree.-120.degree. C., preferably 70.degree.-120.degree. C., under a vacuum between 750-1 mmHg. The reaction under these conditions results in a copolymer of a higher quality as compared to copolymers made by the traditional method without the benefit of a vacuum. If desired, the reaction can be taken to its clear point in a volatile compatibilizing solvent (for example toluene, xylene, or isopropyl alcohol), this solvent can then be removed from the reaction system, and another less volatile solvent, such as dipropylene glycol or polypropylene glycol, may then be added.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.