US4957963A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silicone water based elastomers
Assignee: Dow Silicones Corp
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Filing: 1989-08-30
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Granted: 1990-09-18
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Expires: 2009-08-30
Abstract
Abstract An improved aqueous silicone emulsion which cures to a reinforced elastomer upon removal of water is obtained through the use of an anionic, stable dispersion of fumed silica in water as the source of reinforcing silica. The fumed silica dispersion is combined with an aqueous, anionic emulsion of crosslinkable polydiorganosiloxane and a crosslinking system
Inventors
- 👤 Stephanie A. Burns
- 👤 Donald T. Liles
- 👤 Christine J. Schoenherr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:11
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/02; C08J3/03; C08J3/20; C08J3/205; C08J3/21; C08J2383/00; C08J2383/04
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
54 words
An aqueous silicone emulsion which cures to a reinforced elastomer upon removal of the water comprising (A) an aqueous, anionic emulsion of crosslinkable hydroxy terminated polydiorganosiloxane having a molecular weight of greater than 50,000, (B) an anionic, stable dispersion of fumed silica in water, and (C) sufficient vinyl trialkoxy silane crosslinking system for (A).
Claim 2
Dependent Claim
54 words
An aqueous silicone emulsion which cures to a reinforced elastomer upon removal of the water comprising (A) an aqueous, anionic emulsion of crosslinkable hydroxy terminated polydiorganosiloxane having a molecular weight of greater than 50,000, (B) an anionic, stable dispersion of fumed silica in water, and (C) sufficient vinyl trialkoxy silane crosslinking system for (A).
Claim 3
Dependent Claim
93 words
The reinforced, aqueous silicone emulsion of claim 2 in which (B) is from 1 to 40 parts by weight of fumed silica anionically dispersed in water, and (C) is (i) from 0.2 to 2.0 parts by weight of a crosslinking agent of the formula R.sub.n Si(OR').sub.4-n where n is 0 or 1, R is vinyl and R' are monovalent hydrocarbon radicals having from 1 to 6 carbon atoms, and (ii) from 0.1 to 2.0 parts by weight of a dialkyltindicarboxylate catalyst per 100 parts by weight of the crosslinkable polydiorganosiloxane of claim 1.
Claim 4
Independent Claim
152 words
A method of producing an aqueous silicone emulsion which cures to a reinforced elastomer upon removal of the water, said method comprising the steps of (A) homogenizing (1) 100 parts by weight of hydroxyl endblocked polydiorganosiloxane oligomer, (2) 1 to 40 parts of by weight of separately prepared dispersion of fumed silica anionically dispersed in water, (3) optionally additional water, and (4) surfactant, then (B) adding sufficient acid to adjust the pH to less than 3, then (C) allowing the oligomer to polymerize to the desired degree, then (D) terminating polymerization by raising the pH to greater than 9, and (E) adding (5) 0.1 to 2.0 parts by weight dialkyltindicarboxylate catalyst, then (F) admixing (6) from 0.2 to 2.0 parts by weight of crosslinking agent of the formula R.sub.n Si(OR').sub.4-n where n is 0 or 1, R is vinyl and R' are monovalent hydrocarbon radicals having from 1 to 6 carbon atoms.
Claim 5
Independent Claim
152 words
A method of producing an aqueous silicone emulsion which cures to a reinforced elastomer upon removal of the water, said method comprising the steps of (A) homogenizing (1) 100 parts by weight of hydroxyl endblocked polydiorganosiloxane oligomer, (2) 1 to 40 parts of by weight of separately prepared dispersion of fumed silica anionically dispersed in water, (3) optionally additional water, and (4) surfactant, then (B) adding sufficient acid to adjust the pH to less than 3, then (C) allowing the oligomer to polymerize to the desired degree, then (D) terminating polymerization by raising the pH to greater than 9, and (E) adding (5) 0.1 to 2.0 parts by weight dialkyltindicarboxylate catalyst, then (F) admixing (6) from 0.2 to 2.0 parts by weight of crosslinking agent of the formula R.sub.n Si(OR').sub.4-n where n is 0 or 1, R is vinyl and R' are monovalent hydrocarbon radicals having from 1 to 6 carbon atoms.
Claim 6
Dependent Claim
22 words
The aqueous silicone emulsion which cures to a reinforced elastomer upon removal of the water produced by the method of claim 3.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-09-17 | 1994-03-19 | 1994-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-17 | 1998-03-19 | 1998-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-17 | 2002-03-19 | 2002-09-18 | $7700.00 | Window Closed / Lapsed |