US4408031A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of heat-curable silicone resins usable especially as electrical insulating resins
Assignee: Evonik Operations GmbH
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Filing: 1982-01-27
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Granted: 1983-10-04
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Expires: 2002-01-27
Abstract
Abstract The invention relates to a process for the preparation of heat-curable resins, usable especially as electrically insulating resins, by the reaction of alkoxy siloxanes of the formula ##STR1## in which OR 1 represents an alkoxy group of primary or secondary aliphatic alcohols with 1 to 4 carbon atoms, R 2 represents an alkyl or a phenyl group, a has a value of 1.0 to 1.5, b has a value of 0.1 to 1.0; with a mixture of low molecular weight, multihydric alcohols consisting of (a) 25 to 95 mole percent of neopentylglycol hydroxypivalate, and (b) 75 to 5 mole percent of a low molecular weight, at least trihydric alcohol at temperatures of 80° to 200° C. The resins thus prepared can be utilized advantageously for the insulation of generators, transformers and the like. They possess high elasticity and excellent adhesion.
Inventors
- 👤 Ulrich Holtschmidt
- 👤 Gotz Koerner
- 👤 Manfred Priesch
- 👤 Harald Rau
- 👤 Christian Weitemeyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 14:24
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/04; C08G77/14; C08G77/18; C08G77/38; C08G77/48; C08G77/50; H; H01; H01B; H01B3/00; H01B3/18; H01B3/30; H01B3/46; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31652; Y10T428/31663
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
187 words
In a method for the preparation of heat-curable silicone resins, usable especially as insulating resins, by the reaction of low molecular weight multihydric alcohols with alkoxy siloxanes having the formula ##STR10## in which OR 1 represents an alkoxy group of primary or secondary aliphatic alcohols with 1 to 4 carbon atoms, R 2 represents an alkyl or a phenyl group, a has a value of 1.0 to 1.5, b has a value of 0.1 to 1.0. at temperatures of 80° to 200° C., optionally in the presence of known transesterification catalysts and solvents, with removal of the alcohol R 1 OH, the alkoxy siloxanes being reacted with the alcohols in such relative amounts that one SiOR 1 group corresponds approximately to one COH group, and the reaction being terminated at a degree of conversion of 25 to 80% by cooling to a temperature of less than 80° C., the improvement which comprises the low molecular weight multihydric alcohols being a mixture of (a) 25 to 95 mole percent of neopentylglycol hydroxypivalate, and (b) 75 to 5 mole percent of a low molecular weight, at least trihydric alcohol.
Claim 2
Dependent Claim
187 words
In a method for the preparation of heat-curable silicone resins, usable especially as insulating resins, by the reaction of low molecular weight multihydric alcohols with alkoxy siloxanes having the formula ##STR10## in which OR 1 represents an alkoxy group of primary or secondary aliphatic alcohols with 1 to 4 carbon atoms, R 2 represents an alkyl or a phenyl group, a has a value of 1.0 to 1.5, b has a value of 0.1 to 1.0. at temperatures of 80° to 200° C., optionally in the presence of known transesterification catalysts and solvents, with removal of the alcohol R 1 OH, the alkoxy siloxanes being reacted with the alcohols in such relative amounts that one SiOR 1 group corresponds approximately to one COH group, and the reaction being terminated at a degree of conversion of 25 to 80% by cooling to a temperature of less than 80° C., the improvement which comprises the low molecular weight multihydric alcohols being a mixture of (a) 25 to 95 mole percent of neopentylglycol hydroxypivalate, and (b) 75 to 5 mole percent of a low molecular weight, at least trihydric alcohol.
Claim 3
Dependent Claim
41 words
The method of claim 1 wherein the reaction is carried out with a mixture consisting of: (a) 40 to 80 mole percent of neopentylglycol hydroxypivalate; and (b) 60 to 20 mole percent of a low molecular weight, at least trihydric alcohol.
Claim 4
Dependent Claim
28 words
The method of claim 1 or 2 wherein the reaction is carried out with a mixture in which component (b) is an alcohol having predominantly primary hydroxyl groups.
Claim 5
Dependent Claim
13 words
The method of claim 3 wherein component (b) is trimethylolethane, trimethylolpropane or pentaerythritol.
Claim 6
Dependent Claim
36 words
The method of claim 1, 2, or 4 wherein the reaction is carried out with a mixture of low molecular weight, multihydric alcohols containing up to 50 mole percent of a dihydric alcohol as component (b).
Claim 7
Dependent Claim
11 words
The heat-curable silicone resin obtained by the method of claim 1.
Claim 8
Dependent Claim
11 words
The heat-curable silicone resin obtained by the method of claim 2.
Claim 9
Dependent Claim
11 words
The heat-curable silicone resin obtained by the method of claim 3.
Claim 10
Dependent Claim
11 words
The heat-curable silicone resin obtained by the method of claim 4.
Claim 11
Dependent Claim
11 words
The heat-curable silicone resin obtained by the method of claim 5.
Claim 12
Dependent Claim
9 words
Molded articles formed from the resin of claim 1.
Claim 13
Dependent Claim
10 words
A carrier web impregnated with the resin of claim 1.
References Cited (Backward Citations)
US3701815A
Cited
US3948856A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-10-03 | 1987-04-04 | 1987-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-03 | 1991-04-04 | 1991-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-03 | 1995-04-04 | 1995-10-04 | $7700.00 | Window Closed / Lapsed |