US4292423A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of organopolysiloxanes
Assignee: Wacker Chemie AG
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Filing: 1980-03-27
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Granted: 1981-09-29
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Expires: 2000-03-27
Abstract
Abstract Organopolysiloxanes having substituted carbamoyloxy groups (.tbd.SiOCO--NH--) bonded to silicon via oxygen, which are prepared by reacting an organopolysiloxane containing Si-bonded hydroxyl groups with an organic isocyanate in the presence of an organic tin compound. The stability of the organopolysiloxanes containing carbamoyloxy groups may be improved if the organopolysiloxane having Si-bonded hydroxyl groups is reacted with an organic isocyanate in the presence of an organic tin compound which is supported on a solid carrier and then the reaction product is filtered under anhydrous conditions to remove the supported organic tin compound.
Inventors
- 👤 Rudolf Kaufmann
- 👤 Johann Muller
- 👤 Karl-Heinrich Wegehaupt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 04:49
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/04; C08G77/06; C08G18/00; C08G18/06; C08G18/08; C08G18/16; C08G18/22; C08G18/24; C08G18/28; C08G18/40; C08G18/61; C08K; C08K5/00; C08K5/16; C08K5/29; C08K5/56; C08K5/57
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
74 words
A process for preparing organopolysiloxanes having substituted carbamoyl groups which are bonded to silicon through oxygen, which comprises reacting a diorganopolysiloxane having at least one Si-bonded hydroxyl group with an organic isocyanate having at least 2 isocyanate groups per molecule as the sole reactants in the presence of a catalytic amount of an organic tin compound supported on a solid material and thereafter separating the resultant reaction product from the catalyst under anhydrous conditions.
Claim 2
Dependent Claim
74 words
A process for preparing organopolysiloxanes having substituted carbamoyl groups which are bonded to silicon through oxygen, which comprises reacting a diorganopolysiloxane having at least one Si-bonded hydroxyl group with an organic isocyanate having at least 2 isocyanate groups per molecule as the sole reactants in the presence of a catalytic amount of an organic tin compound supported on a solid material and thereafter separating the resultant reaction product from the catalyst under anhydrous conditions.
Claim 3
Dependent Claim
28 words
The process of claim 1 wherein the product obtained from the reaction of the organopolysiloxane and the organic isocyanate is filtered under anhydrous conditions to remove the catalyst.
Claim 4
Dependent Claim
17 words
The process of claim 1, wherein activated carbon is used as the support for the tin compound.
Claim 5
Dependent Claim
30 words
An organopolysiloxane obtained from the process of claim 1 which has at least one carbamoyloxy group of the formula .tbd.SiOCO--NH-- bonded to the silicon atom of the diorganopolysiloxane via oxygen.
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) | 1984-09-28 | 1985-03-30 | 1985-09-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-28 | 1989-03-30 | 1989-09-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-28 | 1993-03-30 | 1993-09-29 | $7700.00 | Window Closed / Lapsed |