Chemically modified silica fillers, process for producing, and silicone compositions containing same
US6384125B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 11, 2000 |
| Grant date | May 7, 2002 |
| Priority date | — |
| Expiry date | Aug 11, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/12
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
This invention is a process for making modified silica filler comprising the steps of:(A) contacting an acidic aqueous suspension of precipitated or colloidal silica, optionally in the presence of a surfactant and/or a water-miscible solvent, with a combination of(a) a functionalizing coupling agent, and(b) an organometallic hydrophobing compound in a weight ratio of (a) to (b) of at least 0.001 to 1 to form an acidic aqueous suspension of chemically treated silica filler having a pH of 2.0 or less(B) treating the acidic aqueous suspension of the chemically treated filler with an acid-neutralizing agent to increase the pH of the suspension to a range of from greater than 2.0 to 10, and(C) recovering the chemically treated filler.This invention is also modified silica filler that has a pH of from about 5.0 to 10.0, where the silica filler is made by the method of this invention. This invention is also a curable silicone elastomer composition comprising a polyorganosiloxane, the modified silica filler produced by the method of this invention, and a means of curing the polyorganosiloxane into an elastomer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.