US4107358A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing a mica based insulation
Assignee: 555794 ONTARIO Inc
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Filing: 1976-10-29
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Granted: 1978-08-15
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Expires: 1996-10-29
Abstract
Abstract A method for producing a mica based insulation is disclosed. The method comprises the steps of solubilizing a poly (carborane siloxane) containing carborane moieties linked by siloxy groups in a suitable solvent at a loading varying from 20 to 50% by weight of polymer on total weight of the solution, placing a mica sheet of desired thickness on a suitable support, impregnating the supported mica sheet with the solution so as to achieve complete wetting, and curing the impregnated mica sheet by oxidative crosslinking of the polymer for a predetermined time interval and at a predetermined temperature above which oxidative crosslinking of the polymer becomes significant.
Inventors
- 👤 Francis Derrick Bayles
- 👤 Michael Alan Dudley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:47
CPC Classifications
H; H01; H01B; H01B3/00; H01B3/02; H01B3/04; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31652; Y10T428/31663
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
125 words
A method of producing a mica based composite comprising the steps of: (a) solubilizing a poly (carborane siloxane) containing carborane moieties linked by siloxy groups in a suitable solvent at a loading between 20 and 50% weight by weight of total solution to form a solution consisting essentially of said poly (carborane siloxane) and said solvent; (b) placing a mica sheet of a desired thickness on a support; (c) impregnating the supported mica sheet with the solution so as to achieve complete wetting; and (d) curing the impregnated mica sheet by oxidative crosslinking for a predetermined time interval and at a predetermined temperature above which oxidative crosslinking of the polymer becomes significant, but below which oxidative crosslinking becomes catastrophic, as determined by differential scanning calorimetry.
Claim 2
Independent Claim
125 words
A method of producing a mica based composite comprising the steps of: (a) solubilizing a poly (carborane siloxane) containing carborane moieties linked by siloxy groups in a suitable solvent at a loading between 20 and 50% weight by weight of total solution to form a solution consisting essentially of said poly (carborane siloxane) and said solvent; (b) placing a mica sheet of a desired thickness on a support; (c) impregnating the supported mica sheet with the solution so as to achieve complete wetting; and (d) curing the impregnated mica sheet by oxidative crosslinking for a predetermined time interval and at a predetermined temperature above which oxidative crosslinking of the polymer becomes significant, but below which oxidative crosslinking becomes catastrophic, as determined by differential scanning calorimetry.
Claim 3
Dependent Claim
48 words
The method as defined in claim 1, wherein the impregnated mica sheet is cured in air for a period of time at 100° and 200° C sufficient to effectively remove all solvent, followed by a selected period of time at a temperature above which oxidative crosslinking becomes significant.
Claim 4
Dependent Claim
45 words
The method as defined in claim 2, wherein the impregnated mica sheet is cured in air for 15 minutes at 100° C and 30 minutes at 200° C to remove all solvent, followed by 30 minutes at a temperature above which oxidative crosslinking becomes significant.
Claim 5
Dependent Claim
33 words
The method as defined in claim 1, and further comprising the step of heat aging the impregnated mica sheet after curing, at between 100° and 400° C for between 1 and 24 hours.
Claim 6
Dependent Claim
34 words
The method as defined in claim 1, and further comprising the step of partially crosslinking the polymer at between 100° and 500° C for between 1 and 24 hours before solubilization of the polymer.
Claim 7
Dependent Claim
24 words
The method as defined in claim 1, wherein the solvent is selected from the group consisting of ethers, chlorinated hydrocarbons, aromatics and mixtures thereof.
Claim 8
Dependent Claim
16 words
The method as defined in claim 6, wherein the major part of the solvent is xylene.
Claim 9
Dependent Claim
21 words
The method as defined in claim 1, wherein the poly (carborane siloxane) is used as a 30% weight by weight solution.
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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) | 1981-08-14 | 1982-02-13 | 1982-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-08-14 | 1986-02-13 | 1986-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-08-14 | 1990-02-13 | 1990-08-15 | $7700.00 | Window Closed / Lapsed |