Catalytic preparation of high molecular weight polysiloxanes
US4508845A · kind A · utility
8Cited by
4References
14Claims
0Family size
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Key dates
| Filing date | May 31, 1983 |
| Grant date | Apr 2, 1985 |
| Priority date | — |
| Expiry date | May 31, 2003 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2991
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Polysiloxanes of relatively low molecular weight are catalytically polymerized/rearranged into high molecular weight polysiloxanes in the presence of a cationic catalyst comprising a porous, inorganic mineral particulate support having an average pore diameter in excess of 20 .ANG. and a pore volume ranging from 0.2 to 2 ml/g, said porous support being coated with less than 15 mg/m.sup.2 of a film of polymeric material comprising pendant sulfonic or phosphonic acid functions, and said polymeric material being characterized by an ion exchange capacity of less than 2 milliequivalents per gram.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.