Polycondensation of hydroxysilylated polysiloxanes
US4308366A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 18, 1980 |
| Grant date | Dec 29, 1981 |
| Priority date | — |
| Expiry date | Jul 18, 2000 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G77/08
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
High molecular weight organopolysiloxanes are rapidly prepared, without formation of the low molecular weight polysiloxanes, by polycondensing a hydroxysilylated polysiloxane in the presence of a catalytic amount of a catalyst system including (i) an alkali or alkaline earth metal, and (ii) a polyheteromacropolycyclic co-catalyst having the structural formula: ##STR1## wherein .SIGMA. is a divalent radical having the structural formula ##STR2## or a divalent radical having the structural formula: ##STR3## further wherein each R, which may be identical or different, is a divalent hydrocarbon radical, each Q, which also may be identical or different, is a divalent hydrocarbon radical, an oxygen atom or a sulfur atom, and m, n and p are each integers equal to 1, 2 or 3.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.