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US4539418A
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US
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Method for the preparation of pentamethylcyclotrisiloxane
Assignee: Shin-Etsu Chemical Co Ltd
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Filing: 1984-11-16
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Granted: 1985-09-03
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Expires: 2004-11-16
Abstract
Abstract A very efficient method is proposed for the synthetic preparation of pentamethylcyclotrisiloxane by the ring-closing reaction between 1,1,3,3-tetramethyl-1,3-dihydroxy disiloxane and a methyl dialkenyloxysilane such as methyl diisopropenyloxysilane at a moderate temperature in a solution with an organic solvent.
Inventors
- 👤 Toshio Takago
- 👤 Masatoshi Arai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:55
CPC Classifications
C; C07; C07F; C07F7/00; C07F7/02; C07F7/21
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
60 words
A method for the synthetic preparation of pentamethylcyclotrisiloxane which comprises: admixing 1,1,3,3-tetramethyl-1,3-dihydroxy disiloxane and a methyl dialkenyloxysilane represented by the general formula ##STR7## in which R 1 is an alkyl group having from 1 to 4 carbon atoms and R 2 is a hydrogen atom or an alkyl group having from 1 to 4 carbon atoms to effect ring-closing reaction.
Claim 2
Independent Claim
60 words
A method for the synthetic preparation of pentamethylcyclotrisiloxane which comprises: admixing 1,1,3,3-tetramethyl-1,3-dihydroxy disiloxane and a methyl dialkenyloxysilane represented by the general formula ##STR7## in which R 1 is an alkyl group having from 1 to 4 carbon atoms and R 2 is a hydrogen atom or an alkyl group having from 1 to 4 carbon atoms to effect ring-closing reaction.
Claim 3
Dependent Claim
24 words
The method as claimed in claim 1 wherein 1 mole of the methyl dialkenyloxysilane is admixed with 0.8 to 1.2 moles of 1,1,3,3-tetramethyl-1,3-dihydroxy disiloxane.
Claim 4
Dependent Claim
38 words
The method as claimed in claim 1 wherein the mixture of the methyl dialkenyloxysilane and 1,1,3,3-tetramethyl-1,3-dihydroxy disiloxane is admixed with 50 to 1000 parts by weight of an organic solvent per 100 parts by weight of 1,1,3,3-tetramethyl-1,3-dihydroxy disiloxane.
Claim 5
Dependent Claim
23 words
The method as claimed in claim 1 wherein the reaction is performed at a temperature in the range from -10° to +80° C.
References Cited (Backward Citations)
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Cited
US3317578A
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US3234180A
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US3576023A
Cited
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Cited
US4412080A
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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) | 1988-09-02 | 1989-03-04 | 1989-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-02 | 1993-03-04 | 1993-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-02 | 1997-03-04 | 1997-09-03 | $7700.00 | Window Closed / Lapsed |