US3714213A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making cyclopolysiloxanes containing silanic hydrogen
Assignee: General Electric Co
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Filing: 1971-01-06
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Granted: 1973-01-30
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Expires: 1991-01-06
Abstract
Abstract Cyclopolysiloxanes containing both methyl substituents and silanic hydrogen substituents are prepared by catalytically cracking and cyclizing polysiloxanes containing methyl substituents, hydrogen substituents and high molecular weight chain terminal groups, such as hexyldimethylsilyl groups. The catalyst used in the cracking and cyclizing step is an acid treated clay or synthetic alumina silicate. Tetramethylcyclotetrasiloxanes formed by this process are reacted with diethylhydroxyl amine to form tetramethyltetra(diethylaminoxy) cyclotetrasiloxanes. The aminoxy compounds are then used to crosslink silanol stopped polydimethylsiloxane fluids to form elastomers.
Inventors
- 👤 C Miller
- 👤 W Ryan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:18
CPC Classifications
C; C07; C07F; C07F7/00; C07F7/02; C07F7/21; C08; C08G; C08G77/00; C08G77/04; C08G77/38
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
137 words
A method of producing methyl hydrogen cyclopolysiloxanes containing Si bonded H which comprises A. heating together a. a starting polysiloxane containing methyl radicals and Si bonded H radicals and containing or in the presence of a polysiloxane containing triorganosilyl chain-stopping groups wherein at least one of the organo radicals per polysiloxane polymer contain at least three carbon atoms, wherein the organo groups are selected from the class consisting of hydrocarbyl, halohydrocarbyl and cyanoalkyl having not more than 19 carbon atoms, b. a small but effective amount of an acid catalyst absorbed on a carrier selected from the class consisting of carbon black, clay, molecular sieves and organic ion exchange resins sufficient to effect cracking and cyclization of the polysiloxanes containing methyl radicals and Si bonded H radicals, and B. removing methyl hydrogen cyclopolysiloxanes from the reaction zone.
Claim 2
Independent Claim
137 words
A method of producing methyl hydrogen cyclopolysiloxanes containing Si bonded H which comprises A. heating together a. a starting polysiloxane containing methyl radicals and Si bonded H radicals and containing or in the presence of a polysiloxane containing triorganosilyl chain-stopping groups wherein at least one of the organo radicals per polysiloxane polymer contain at least three carbon atoms, wherein the organo groups are selected from the class consisting of hydrocarbyl, halohydrocarbyl and cyanoalkyl having not more than 19 carbon atoms, b. a small but effective amount of an acid catalyst absorbed on a carrier selected from the class consisting of carbon black, clay, molecular sieves and organic ion exchange resins sufficient to effect cracking and cyclization of the polysiloxanes containing methyl radicals and Si bonded H radicals, and B. removing methyl hydrogen cyclopolysiloxanes from the reaction zone.
Claim 3
Dependent Claim
18 words
The method of claim 1 further characterized by the acid catalyst being an acid absorbed on a carrier.
Claim 4
Dependent Claim
13 words
The method of claim 2 further characterized by the carrier being a clay.
Claim 5
Dependent Claim
20 words
The method of claim 3 further characterized by the acid being selected from the class consisting of H2SO4 and H3PO4.
Claim 6
Dependent Claim
14 words
The method of claim 3 further characterized by the clay being an alumina-silicate clay.
Claim 7
Dependent Claim
28 words
The method of claim 2 further characterized by from 0.25 percent to 2 percent of catalyst by weight based upon the weight of the starting polysiloxane being present.
Claim 8
Dependent Claim
46 words
The method of claim 1 further characterized by the starting polysiloxane having the average formula, where at least one of the terminal silicon atoms containing R3 radicals is a hydrocarbyl having at least three carbon atoms and n has a value of from 5 to 40.
Claim 9
Dependent Claim
15 words
The method of claim 1 further characterized by the triorganosilyl groups being hexyl dimethylsilyl groups.
Claim 10
Dependent Claim
27 words
The method of claim 1 further characterized by at least one of the R radicals of each of the triorganosilyl groups containing at least six carbon atoms.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-30 | 1976-07-31 | 1977-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-30 | 1980-07-31 | 1981-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-30 | 1984-07-31 | 1985-01-30 | $7700.00 | Window Closed / Lapsed |