US4855472A
Expired / Lapsed
US
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Process for chain stabilization of organopolysiloxanes
Assignee: Wacker Chemie AG
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Filing: 1987-06-19
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Granted: 1989-08-08
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Expires: 2007-06-19
Abstract
Abstract Oligomeric siloxanol mixtures containing siloxanols of the formula HO--SiR.sub.2 O[SiR.sub.2 O--.sub.n H and those of the formula R.sub.3 SiO--[SiR.sub.2 O--.sub.m H where R represents the same or different monovalent hydrocarbon radicals, monovalent halogenated hydrocarbon radicals having from 1 to 18 carbon atoms or hydrogen atoms and n and m are the same or different integers are prepared by hydrolyzing a mixture containing at least one compound of the formula R 3 SiCl and at least one compound of the formula R 2 SiCl 2 . These oligomeric siloxanol mixtures can be reacted with the terminal Si-bonded hydroxyl groups of α, ω-dihydroxypolyorganosiloxanes.
Inventors
- 👤 Jurgen Burkhardt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 07:46
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/04; C08G77/06; C08G77/10
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
154 words
A process for preparing oligomeric siloxanol mixtures containing siloxanols of the formula HO--SiR.sub.2 O--[SiR.sub.2 O]--.sub.n H (I) and those of the formula R.sub.3 SiO--[SiR.sub.2 O]--.sub.m H (II) where R is selected from the group consisting of monovalent hydrocarbon radicals, halogenated monovalent hydrocarbon radicals having from 1 to 18 carbon atoms and hydrogen atoms, and n and m are each integers having an average value of from 4 to 30, which comprises reacting a mixture containing at least one compound of the formula R 3 SiCl and at least one compound of the formula R 2 SiCl 2 with water in the absence of an organic solvent, removing the aqueous phase and distilling off the lower-boiling by-products at a temperature of from 100° to 140° C. under a pressure of from 5 to 15 hPa (absolute), to form a mixture having a viscosity of from 10 to 80 mm 2 s -1 at 25° C.
Claim 2
Dependent Claim
154 words
A process for preparing oligomeric siloxanol mixtures containing siloxanols of the formula HO--SiR.sub.2 O--[SiR.sub.2 O]--.sub.n H (I) and those of the formula R.sub.3 SiO--[SiR.sub.2 O]--.sub.m H (II) where R is selected from the group consisting of monovalent hydrocarbon radicals, halogenated monovalent hydrocarbon radicals having from 1 to 18 carbon atoms and hydrogen atoms, and n and m are each integers having an average value of from 4 to 30, which comprises reacting a mixture containing at least one compound of the formula R 3 SiCl and at least one compound of the formula R 2 SiCl 2 with water in the absence of an organic solvent, removing the aqueous phase and distilling off the lower-boiling by-products at a temperature of from 100° to 140° C. under a pressure of from 5 to 15 hPa (absolute), to form a mixture having a viscosity of from 10 to 80 mm 2 s -1 at 25° C.
Claim 3
Dependent Claim
82 words
A process for blocking terminal hydroxyl groups and changing the molecular weight of organopolysiloxanes having hydroxyl groups in the terminal units, which comprises reacting the organopolysiloxanes having terminal Si-bonded hydroxyl groups with the oligomeric siloxanol mixtures prepared in accordance with the process of claim 1 to form organopolysiloxanes having terminal units of the formula R.sub.3 SiO where R is selected from the group consisting of monovalent hydrocarbon radicals, halogenated monovalent hydrocarbon radicals having from 1 to 18 carbon atoms and hydrogen atoms.
Claim 4
Dependent Claim
20 words
The process of claim 2, wherein the reaction is carried out in the presence of an acid or basic catalyst.
Claim 5
Dependent Claim
12 words
The process of claim 3, wherein the acid catalyst is phosphonitrile chlorides.
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) | 1992-08-07 | 1993-02-06 | 1993-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-07 | 1997-02-06 | 1997-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-07 | 2001-02-06 | 2001-08-08 | $7700.00 | Window Closed / Lapsed |