US4677141A
Expired / Lapsed
US
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Method of improving heat stability of pigmentable silicone elastomer
Assignee: Dow Silicones Corp
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Filing: 1982-07-30
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Granted: 1987-06-30
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Expires: 2002-07-30
Abstract
Abstract A method of improving the heat stability of silicone elastomers is disclosed. An improved pigmentable silicone elastomeric composition is produced by mixing a silicone elastomer composition having a vinyl radical content of from 0.01 to 0.1 percent by weight with a pretreated, white clay having a surface area of less than 50 m 2 /g, said surface containing olefinic unsaturated siloxy groups, and an organic peroxide vulcanizing agent. The improved silicone elastomeric composition is formed, then heated to vulcanize, to yield a silicone elastomer having improved resistance to the effects of elevated temperatures. The improved silicone elastomeric composition is also claimed. The improved silicone elastomeric composition can be pigmented.
Inventors
- 👤 David J. Cornelius
- 👤 Richard L. Przybyla
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 04:00
CPC Classifications
C; C08; C08K; C08K3/00; C08K3/34; C08K3/346; C08K9/00; C08K9/04; C08K9/06
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
180 words
Method of improving the heat stability of a silicone elastomer comprising (A) mixing (1) 100 parts by weight of a mixture consisting essentially of 100 parts by weight of a polydiorganosiloxane gum having organic radicals selected from the group consisting of methyl, vinyl, phenyl, and 3,3,3-trifluoropropyl, and from 10 to 100 parts by weight treated reinforcing silica filler, said mixture (1) having a vinyl radical content of from 0.01 to 0.1 percent by weight; (2) from 1 to 150 parts by weight of pretreated, white clay having a surface area of less than 50 m 2 /g, said surface having been treated so that the surface contains olefinic unsaturated siloxy groups; and (3) organic peroxide vulcanizing agent to yield an improved silicone elastomeric composition (B) forming the improved silicone elastomeric composition into a shape, and (C) heating the formed silicone elastomeric composition to an elevated temperature for a time sufficient to vulcanize the silicone elastomeric composition, the vulcanized silicone elastomer having improved heat stability, without effecting the ability of the silicone elastomeric composition to be pigmented to a desired color.
Claim 2
Dependent Claim
180 words
Method of improving the heat stability of a silicone elastomer comprising (A) mixing (1) 100 parts by weight of a mixture consisting essentially of 100 parts by weight of a polydiorganosiloxane gum having organic radicals selected from the group consisting of methyl, vinyl, phenyl, and 3,3,3-trifluoropropyl, and from 10 to 100 parts by weight treated reinforcing silica filler, said mixture (1) having a vinyl radical content of from 0.01 to 0.1 percent by weight; (2) from 1 to 150 parts by weight of pretreated, white clay having a surface area of less than 50 m 2 /g, said surface having been treated so that the surface contains olefinic unsaturated siloxy groups; and (3) organic peroxide vulcanizing agent to yield an improved silicone elastomeric composition (B) forming the improved silicone elastomeric composition into a shape, and (C) heating the formed silicone elastomeric composition to an elevated temperature for a time sufficient to vulcanize the silicone elastomeric composition, the vulcanized silicone elastomer having improved heat stability, without effecting the ability of the silicone elastomeric composition to be pigmented to a desired color.
Claim 3
Dependent Claim
20 words
The method of claim 1 in which the mixture (1) is heated before the addition of the pretreated, white clay.
Claim 4
Dependent Claim
23 words
The method of claim 1 in which the mixture (1) has a vinyl radical content of from 0.025 to 0.1 percent by weight.
Claim 5
Dependent Claim
23 words
The method of claim 2 in which the mixture (1) has a vinyl radical content of from 0.025 to 0.1 percent by weight.
Claim 6
Dependent Claim
23 words
The method of claim 2 in which the mixture (1) has a vinyl radical content of from 0.05 to 0.1 percent by weight.
Claim 7
Dependent Claim
23 words
The method of claim 2 in which the mixture (1) has a vinyl radical content of from 0.05 to 0.07 percent by weight.
Claim 8
Dependent Claim
25 words
The method of claim 1 in which the treated reinforcing silica filler is present in an amount of from 25 to 85 parts by weight.
Claim 9
Dependent Claim
30 words
The method of claim 7 in which the mixture (1) has a vinyl radical content of from 0.025 to 0.1 percent by weight and the pretreated, white clay is kaolinite.
Claim 10
Dependent Claim
29 words
The method of claim 8 in which the kaolinite is present in an amount of from 10 to 110 parts by weight and has a surface containing vinylsiloxy groups.
Claim 11
Dependent Claim
28 words
The method of claim 9 in which the organic peroxide vulcanizing agent is vinyl specific and present in an amount of from 0.5 to 2 parts by weight.
Claim 12
Dependent Claim
15 words
The method of claim 10 in which there is also present a heat stable pigment.
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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) | 1990-06-29 | 1990-12-29 | 1991-06-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-29 | 1994-12-29 | 1995-06-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-29 | 1998-12-29 | 1999-06-30 | $7700.00 | Window Closed / Lapsed |