US3832419A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Organopolysiloxane-polycarbonate block copolymers
Assignee: General Electric Co
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Filing: 1973-03-23
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Granted: 1974-08-27
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Expires: 1993-03-23
Abstract
Abstract An improved process for the preparation of organopolysiloxanepolycarbonate block copolymers from halogen chain-stopped organopolysiloxane, dihydric phenol and phosgene is provided by using ammonia as the acceptor in the initial dihydric phenolhalogen chain-stopped organopolysiloxane reaction, this reaction being followed by phosgenation to form the copolymer.
Inventors
- 👤 W Merritt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:24
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/42; C08G77/448
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
12 words
The process of claim 1 wherein said dihydric phenon is a bisphenol.
Claim 2
Dependent Claim
11 words
Process of claim 2 wherein said dihydric phenol is 2,2-bis(4-hydroxyphenyl) propane.
Claim 3
Dependent Claim
10 words
Process of claim 1 wherein said polydiorgano-siloxane is a polydimethylsiloxane.
Claim 4
Dependent Claim
11 words
The process of claim 1 wherein said acid acceptor is ammonia.
Claim 5
Dependent Claim
13 words
The process of claim 1 wherein said acid acceptor is a primary amine.
Claim 6
Dependent Claim
12 words
The process of claim 1 wherein said acid acceptor is secondary amine.
Claim 7
Dependent Claim
18 words
The process of claim 1 wherein the reaction of A and B is at from 0* to 100C.
Claim 8
Dependent Claim
18 words
The process of claim 1 wherein the reaction of A and B is at from 20* to 50C.
References Cited (Backward Citations)
US3189662A
Cited
US3679774A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-26 | 1978-02-25 | 1978-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-26 | 1982-02-25 | 1982-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-26 | 1986-02-25 | 1986-08-27 | $7700.00 | Window Closed / Lapsed |