US5130399A
Expired / Lapsed
US
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Process for preparation of organopolysiloxanes
Assignee: Shin-Etsu Chemical Co Ltd
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Filing: 1991-05-20
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Granted: 1992-07-14
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Expires: 2011-05-20
Abstract
Abstract The present process for producing an organopolysiloxane is characterized in that the polymerization of an organosiloxane by using an alkali catalyst is carried out in the presence of a reversible dehydrating agent such as magnesium sulfate and calcium carbonate or an irreversible dehydrating agent such as calcium oxide. According to this manufacturing process, there is a quite distinct mutual relation between the preset composition of the organopolysiloxane to be manufactured and the viscosity of the actually manufactured organopolysiloxane.
Inventors
- 👤 Masayuki Ikeno
- 👤 Hiroyasu Hara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:48
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/04; C08G77/06
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
21 words
A process for producing an organopolysiloxane, comprising polymerizing an organosiloxane using an alkali catalyst in the presence of a dehydrating agent.
Claim 2
Dependent Claim
21 words
A process for producing an organopolysiloxane, comprising polymerizing an organosiloxane using an alkali catalyst in the presence of a dehydrating agent.
Claim 3
Dependent Claim
34 words
A process as claimed in claim 1, wherein said dehydrating agent is at least one reversible dehydrating agent selected from the group consisting of magnesium sulfate, calcium sulfate, sodium sulfate, calcium carbonate, and alumina.
Claim 4
Dependent Claim
26 words
A process as claimed in claim 2, wherein said dehydrating agent is present in an amount of 0.15 to 1.5% by weight based on the organosiloxane.
Claim 5
Dependent Claim
29 words
A process as claimed in claim 1, wherein said dehydrating agent is at least one irreversible dehydrating agent selected from the group consisting of calcium oxide and barium oxide.
Claim 6
Dependent Claim
26 words
A process as claimed in claim 3, wherein said dehydrating agent is present in an amount of 0.15 to 1.5% by weight based on the organosiloxane.
Claim 7
Dependent Claim
30 words
A process as claimed in claim 1, wherein said alkali catalyst is at least one selected from the group consisting of alkali metal compounds, alkylphosphonium hydroxides, alkylammonium hydroxides, and 1,8-diazabicyclo(5.4.0)undecene-7.
Claim 8
Dependent Claim
33 words
A process as claimed in claim 6, wherein said alkali catalyst is an alkylphosphonium hydroxide or an alkylammonium hydroxide and the polymerization is carried out at a temperature of 100° to 130° C.
Claim 9
Dependent Claim
28 words
A process as claimed in claim 7, wherein said alkali catalyst is used in an amount of 0.001 to 0.1% by weight based on the raw material organosiloxane.
Claim 10
Dependent Claim
45 words
A process as claimed in claim 6, wherein said alkali catalyst is at least one alkali metal compound selected from the group consisting of NaOH, KOH, sodium silanolates, and potassium silanolates and the polymerization is carried out at a temperature of 130° to 160° C.
Claim 11
Dependent Claim
16 words
A process as claimed in claim 9, wherein the dehydrating agent is an irreversible dehydrating agent.
Claim 12
Dependent Claim
38 words
A process as claimed in claim 9, wherein said alkali catalyst is used in an amount such that the molar ratio of the silicon atoms in the organosiloxane to the alkali metal atom ranges from 2,000 to 5,000.
Claim 13
Dependent Claim
110 words
A process as claimed in claim 1, wherein said organosiloxane is at least one member selected from the group consisting of cyclic diorganosiloxane oligomers represented by the following formula: ##STR4## wherein R represents a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms and p is an integer of 3 to 10, linear diorganosiloxane oligomers represented by the following formula: ##STR5## wherein R has the same meaning as defined above and q is an integer of 2 to 10, and linear diorganosiloxane oligomers represented by the following formula: ##STR6## wherein R has the same meaning as defined above and r is an integer of 0 to 10.
References Cited (Backward Citations)
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Cited
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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) | 1995-07-14 | 1996-01-13 | 1996-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-07-14 | 2000-01-13 | 2000-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-07-14 | 2004-01-13 | 2004-07-14 | $7700.00 | Window Closed / Lapsed |