Emulsions of reinforced polydiorganosiloxane latex
US4567231A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 25, 1984 |
| Grant date | Jan 28, 1986 |
| Priority date | — |
| Expiry date | Jun 25, 2004 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2383/04
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
This invention is a method of producing a latex of crosslinked polydiorganosiloxane reinforced with colloidal silica. The method allows the production of a latex having a relatively high amount of silica present in relation to the polymer because the water used to form the emulsion can be that present in the acidic colloidal silica sol used in the method. The high solids latex can be useful as a caulking material. The method homogenizes a hydroxyl endblocked polydiorganosiloxane, a silane of the formula R'.sub.a Si(OR.sup.3).sub.4-a where R' is a monovalent hydrocarbon radical of up to 12 carbon atoms, R.sup.3 is an alkyl radical of 1 to 6 carbon atoms, a partial hydrolyzate, or mixture of silane and hydrolyzate, and a is 0 or 1; a surface active anionic catalyst of the formulae R.sup.2 C.sub.6 H.sub.4 SO.sub.3 H wherein R.sup.2 is a monovalent hydrocarbon radical of at least 6 carbon atoms, R.sup.2 OSO.sub.2 OH, or ##STR1## wherein R.sup.4 is H or R.sup.2 ; and greater than 1 part by weight of colloidal silica present as an acidic sol in water. This homogenized mixture is an oil-in-water emulsion. This emulsion is maintained at a temperature of 15.degree. to 30.degree. C. for at l…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.