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US3671480A
Expired / Lapsed
US
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Heat-curable elastomeric silicone compositions
Assignee: Shin-Etsu Chemical Co Ltd
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Filing: 1969-12-18
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Granted: 1972-06-20
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Expires: 1989-12-18
Abstract
Abstract A heat curable elastomeric silicone composition comprising a mixture of two polydiorganosiloxanes, each of which contains vinyl unsaturation; a silica filler; a polyorganohydrogensiloxane and a platinum compound; and a method for the preparation of vulcanizates thereof. The composition is cured for a period up to about one hour and is then post-cured for up to about 24 hours to yield a vulcanized elastomer having high tear strength, flame retardance, heat resistance and superior compression set.
Inventors
- 👤 Tadashi Wada
- 👤 Kunio Itoh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:22
CPC Classifications
C; C08; C08L; C08L83/00; C08L83/04; C08G; C08G77/00; C08G77/04; C08G77/12; C08G77/20
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
54 words
The heat-curable elastomeric silicone composition of claim 1 in which the polyorganosiloxane having at least three Si-H groups in each molecule is selected from the group consisting of trialkylsilyl end-blocked polymethylhydrogensiloxane, a tetrasiloxane having the formula Si (-O-Si(CH3)2H)4, a siloxane copolymer consisting of SiO2 units and (CH3)2HSi-O-SiH(CH3)2 units, and copolymer of methylhydrogensiloxane and dialkylsiloxane.
Claim 2
Dependent Claim
33 words
The heat-curable elastomeric silicone composition of claim 1 in which the platinum compound is present in an amount from about 0.5 to about 20 ppm by weight relative to the total polysiloxane components.
Claim 3
Dependent Claim
33 words
The heat-curable elastomeric silicone compositIon of claim 1 in which the platinum compound is a soluble platinum compound selected from the group consisting of chloroplatinic acid and complexes of platinum chloride and olefines.
Claim 4
Dependent Claim
27 words
The heat-curable elastomeric silicone composition of claim 1 containing in addition a dispersing agent selected from the group consisting of low molecular weight siloxane esters and silanols.
Claim 5
Dependent Claim
64 words
A process for preparing vulcanizates of elastomeric silicone compositions having exceptional tear strengths comprising: a. heating the composition of Claim 1 at about 100* C to about 400* C for from about 30 seconds to about 1 hour; and b. post-curing the composition by heating at about 150* C to about 250* C for a period of from about 2 to about 24 hours.
Claim 6
Dependent Claim
15 words
The process of claim 6 wherein heating step (a) is carried out under atmospheric pressure.
Claim 7
Dependent Claim
15 words
The process of claim 6 wherein heating step (a) is carried out under superatmospheric pressure.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-20 | 1975-12-20 | 1976-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-20 | 1979-12-20 | 1980-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-20 | 1983-12-20 | 1984-06-20 | $7700.00 | Window Closed / Lapsed |