Patent US5189193A successfully refreshed from Google Patents.
US5189193A
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Process for preparation of cyclic organohydrosiloxanes
Assignee: Dow Silicones Corp
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Filing: 1992-08-31
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Granted: 1993-02-23
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Expires: 2012-08-31
Abstract
Abstract The present invention is a process for preparation of cyclic organohydrosiloxanes. The process comprises contacting an organohydrodihalosilane with a substantially stoichiometric quantity of water to form a mixture containing cyclic and short-chain linear organohydrosiloxanes. This mixture is distilled to separate the cyclic and short-chain linear organohydrosiloxanes from other components of the mixture. The separated cyclic and short-chain linear organohydrosiloxanes are then contacted with an additional quantity of water to effect hydrolysis and condensation of the short-chain linear organohydrosiloxanes to higher molecular weight linear organohydrosiloxanes which are easily separated from the cyclic organohydrosiloxanes by a second distillation step.
Inventors
- 👤 Steven K. Freeburne
- 👤 David E. Puckett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:22
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/04; C08G77/32; C08G77/36; C07; C07F; C07F7/00; C07F7/02; C07F7/21
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
131 words
A process of cyclic organohydrosiloxanes, the process comprising: (A) contacting an organohydrodihalosilane described by formula RHSiX.sub.2 with a substantially stoichiometric quantity of water at a temperature within a range of about 0° C. to 50° C. to form a first mixture; (B) distilling the first mixture to recover a second mixture comprising cyclic organohydrosiloxanes and short-chained polyorganohydrosiloxanes; (C) contacting the second mixture with water to effect polymerization of the short-chained polyorganohydrosiloxane to long chain polyorganohydrosiloxanes and forming a third mixture; (D) distilling the third mixture to recover cyclic organohydrosiloxanes described by formula (RHSiO).sub.n ; where each R is a radical independently selected from a group consisting of alkyls comprising one to 20 carbon atoms, alkenyls comprising one to 20 carbon atoms, and aryls; X is a halogen; and n=3 to 12.
Claim 2
Dependent Claim
131 words
A process of cyclic organohydrosiloxanes, the process comprising: (A) contacting an organohydrodihalosilane described by formula RHSiX.sub.2 with a substantially stoichiometric quantity of water at a temperature within a range of about 0° C. to 50° C. to form a first mixture; (B) distilling the first mixture to recover a second mixture comprising cyclic organohydrosiloxanes and short-chained polyorganohydrosiloxanes; (C) contacting the second mixture with water to effect polymerization of the short-chained polyorganohydrosiloxane to long chain polyorganohydrosiloxanes and forming a third mixture; (D) distilling the third mixture to recover cyclic organohydrosiloxanes described by formula (RHSiO).sub.n ; where each R is a radical independently selected from a group consisting of alkyls comprising one to 20 carbon atoms, alkenyls comprising one to 20 carbon atoms, and aryls; X is a halogen; and n=3 to 12.
Claim 3
Dependent Claim
10 words
A process according to claim 1, where R is methyl.
Claim 4
Dependent Claim
10 words
A process according to claim 1, where X is chlorine.
Claim 5
Dependent Claim
28 words
A process according to claim 1, where a substantially stoichiometric quantity of water is about 0.8 mole of water to 1.2 mole of water per mole of organohydrodihalosilane.
Claim 6
Dependent Claim
30 words
A process according to claim 1, where a substantially stoichiometric quantity of water is about 0.9 mole of water to less than 1.0 mole of water per mole of organohydrodihalosilane.
Claim 7
Dependent Claim
20 words
A process according to claim 1, where the temperature is within a range of about 10° C. to 30° C.
Claim 8
Dependent Claim
24 words
A process according to claim 1, where hydrogen chloride gas generated by the process is recovered and used as a feed to another process.
Claim 9
Dependent Claim
26 words
A process according to claim 1, where the second mixture is contacted with about 0.01 to 10 volumes of water per volume of the second mixture.
Claim 10
Dependent Claim
26 words
A process according to claim 1, where the second mixture is contacted with about 0.05 to 1.0 volume of water per volume of the second mixture.
Claim 11
Dependent Claim
10 words
A process according to claim 1, where n=4 to 8.
Claim 12
Dependent Claim
127 words
A process for preparation of cyclic organohydrosiloxanes, the process comprising: (A) contacting an organohydrodihalosilane described by formula RHSiX.sub.2 with about 0.8 mole of water to 1.2 mole of water per mole of organohydrodihalosilane at a temperature within a range of about 10° C. to 30° "C. to form a first mixture; (B) distilling the first mixture to recover a second mixture comprising cyclic organohydrosiloxanes and short-chained polyorganohydrosiloxanes; (C) contacting the second mixture with about 0.05 to 1.0 volume of water per volume of the second mixture to effect polymerization of the short chained polyorganohydrosiloxane to long-chain polyorganohydrosiloxanes and forming a third mixture; (D) distilling the third mixture to recover cyclic organohydrosiloxanes described by formula (RHSiO).sub.n ; where R is methyl, X is chlorine, and n=4 to 8.
Claim 13
Dependent Claim
127 words
A process for preparation of cyclic organohydrosiloxanes, the process comprising: (A) contacting an organohydrodihalosilane described by formula RHSiX.sub.2 with about 0.8 mole of water to 1.2 mole of water per mole of organohydrodihalosilane at a temperature within a range of about 10° C. to 30° "C. to form a first mixture; (B) distilling the first mixture to recover a second mixture comprising cyclic organohydrosiloxanes and short-chained polyorganohydrosiloxanes; (C) contacting the second mixture with about 0.05 to 1.0 volume of water per volume of the second mixture to effect polymerization of the short chained polyorganohydrosiloxane to long-chain polyorganohydrosiloxanes and forming a third mixture; (D) distilling the third mixture to recover cyclic organohydrosiloxanes described by formula (RHSiO).sub.n ; where R is methyl, X is chlorine, and n=4 to 8.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1996-02-23 | 1996-08-24 | 1997-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-02-23 | 2000-08-24 | 2001-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-02-23 | 2004-08-24 | 2005-02-23 | $7700.00 | Window Closed / Lapsed |