Methods for the preparation of liquid silicone rubber base and liquid silicone rubber composition
US5872172A · kind A · utility
3Cited by
6References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 5, 1997 |
| Grant date | Feb 16, 1999 |
| Priority date | — |
| Expiry date | Dec 5, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G77/20
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A liquid silicone rubber base is prepared by mixing an organopolysiloxane containing at least two alkenyl groups, reinforcing silica having a BET specific surface area of at least 50 m.sup.2 /g, and optionally, a mixing assistant. The mixing step includes a first stage of mixing under a first shear stress of at least 1.times.10.sup.6 N/m.sup.2 for 1-5 minutes and a second stage of mixing under a second shear stress which is up to 1/2 of the first shear stress for at least 2 minutes. The silicone rubber base is sufficiently shelf stable to minimize a viscosity rise with time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.