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Patent US4762937A successfully refreshed from Google Patents.
US4762937A
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Method for preparing linear organopolysiloxanediols
Assignee: Wacker Chemie AG
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Filing: 1987-08-06
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Granted: 1988-08-09
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Expires: 2007-08-06
Abstract
Abstract Linear organopolysiloxanediols are prepared by continuously introducing cyclic organopolysiloxanes, water in an amount of at least 14 mols per gram atom of silicon contained in the cyclic organopolysiloxanes used and water-soluble acid into a recirculating reactor and thereafter separating the aqueous phase from the organopolysiloxanediols more or less immediately after the reaction mixture exits from the recirculating reactor.
Inventors
- 👤 Ralph Ottlinger
- 👤 Rudolf Reitmeier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 13:36
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/04; C08G77/06; C08G77/14; C08G77/16
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
83 words
A method for preparing linear organopolysiloxanediols, which comprises continuously introducing cyclic organopolysiloxanes, water in an amount of at least 14 moles per gram atom of silicon present in the cyclic organopolysiloxanes and a water-soluble acid catalyst selected from the group consisting of Bronsted acids having an acid dissociation constant of at least 6.5·10 -2 at 25° C., Lewis acids and mixtures thereof into a loop reactor while continuously separating the aqueous phase from the organopolysiloxanediols as the reaction mixture exits from the reactor.
Claim 2
Independent Claim
83 words
A method for preparing linear organopolysiloxanediols, which comprises continuously introducing cyclic organopolysiloxanes, water in an amount of at least 14 moles per gram atom of silicon present in the cyclic organopolysiloxanes and a water-soluble acid catalyst selected from the group consisting of Bronsted acids having an acid dissociation constant of at least 6.5·10 -2 at 25° C., Lewis acids and mixtures thereof into a loop reactor while continuously separating the aqueous phase from the organopolysiloxanediols as the reaction mixture exits from the reactor.
Claim 3
Dependent Claim
12 words
The method of claim 1, wherein the water-soluble acid is sulfuric acid.
Claim 4
Dependent Claim
38 words
The method of claim 1, wherein from 0 to 10 percent by weight based on the weight of the cyclic organopolysiloxanes of a silane having Si-bonded halogen is introduced simultaneously with the cyclic organopolysiloxanes into the loop reactor.
Claim 5
Dependent Claim
63 words
The method of claim 1, wherein a co-catalyst is introduced into the loop reactor, in which the co-catalyst is selected from the group having the formulas, NR 2 3 HX, NR 2 4 X, PR 2 3 HX and PR 2 4 X, where R 2 is an alkyl radical having from 1 to 30 carbon atoms and X is an inorganic anion.
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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) | 1991-08-09 | 1992-02-08 | 1992-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-09 | 1996-02-08 | 1996-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-09 | 2000-02-08 | 2000-08-09 | $7700.00 | Window Closed / Lapsed |