Lightly crosslinked poly(n-alkylmethylsiloxanes) and methods of producing same
US5493041A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 21, 1995 |
| Grant date | Feb 20, 1996 |
| Priority date | — |
| Expiry date | Jul 21, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G77/50
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The crosslinking and simultaneous alkylation of poly(hydridomethylsiloxanes) form crosslinked siloxanes having n-alkylmethyl groups. Without changing the chain length of the poly(hydridomethylsiloxane) starting material, a family of lightly crosslinked siloxanes having n-alkylmethyl groups, with a range of viscosities, can be produced using one or more alpha-olefins along with a small amount of an unconjugated alpha, omega-diene added as a crosslinker. The poly(hydridomethyl siloxanes) are made from highly pure silanol-free hexamethyldisiloxane and highly pure mixtures of silanol-free tetramethylcyclotetrasiloxane (D.sup.H 4) and pentamethylcyclopentasiloxane D.sup.H 5 containing no more than about 100 parts per million (ppm) water, with anhydrous trifluoromethane sulfonic acid (triflic acid, CF.sub.3 SO.sub.3 H), at room temperature, to provide linear poly(hydridomethylsiloxanes) having degrees of polymerization of up to about 250.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.