US4644053A
Expired / Lapsed
US
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Cyclic polycarbonate oligomers and methods for their preparation and use
Assignee: Cyclics Corp
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Filing: 1985-02-22
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Granted: 1987-02-17
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Expires: 2005-02-22
Abstract
Abstract Cyclic polycarbonate (or thiol analog) oligomer mixtures are prepared by the reaction of bishaloformates or their thio analogs or mixtures thereof with dihydroxy or dimercapto compounds, with alkali metal hydroxides and various amines. The oligomer mixtures may be converted to polycarbonates or their thiol analogs by a method which is particularly adaptable to integration with polycarbonate processing operations.
Inventors
- 👤 Daniel J. Brunelle
- 👤 Thomas L. Evans
- 👤 Thomas G. Shannon
- 👤 David A. Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:42
CPC Classifications
C; C08; C08G; C08G64/00; C08G64/20; C08G64/26; C08G64/30; C08G75/00; C08G75/28
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
58 words
A composition consisting essentially of a mixture of cyclic oligomers having varying degrees of polymerization from 2 to about 30, the structural units in said oligomers having the formula ##STR4## at least about 60% of the total number of R values in said composition being aromatic and the balance of the R values being aliphatic, alicyclic or aromatic.
Claim 2
Dependent Claim
58 words
A composition consisting essentially of a mixture of cyclic oligomers having varying degrees of polymerization from 2 to about 30, the structural units in said oligomers having the formula ##STR4## at least about 60% of the total number of R values in said composition being aromatic and the balance of the R values being aliphatic, alicyclic or aromatic.
Claim 3
Dependent Claim
20 words
A composition according to claim 1 which consists essentially of cyclic oligomers having degrees of polymerization up to about 20.
Claim 4
Dependent Claim
18 words
A composition according to claim 2 which contains no more than about 10% by weight of linear oligomers.
Claim 5
Dependent Claim
14 words
A composition according to claim 3 wherein all of the R values are aromatic.
Claim 6
Dependent Claim
22 words
A composition according to claim 2 which contains a substantial proportion of oligomers having degrees of polymerization from 2 to about 12.
Claim 7
Dependent Claim
26 words
A composition according to claim 3 which comprises about 50-70% by weight of cyclic oligomers having degrees of polymerization in the range from 2 to 5.
Claim 8
Dependent Claim
18 words
A composition according to claim 6 which contains no more than about 5% by weight of linear oligomers.
Claim 9
Dependent Claim
51 words
A composition according to claim 4 wherein each R has the formula --A.sup.1 --Y.sup.2 --A.sup.2 --, (III) wherein each of A 1 and A 2 is a single-ring divalent aromatic radical and Y 2 is a bridging radical in which one or two atoms separate A 1 from A 2 .
Claim 10
Dependent Claim
21 words
A composition according to claim 8 wherein each of A 1 and A 2 is p-phenylene and Y 2 is isopropylidene.
Claim 11
Dependent Claim
22 words
A composition according to claim 9 which contains a substantial proportion of oligomers having degrees of polymerization from 2 to about 12.
Claim 12
Dependent Claim
25 words
A composition according to claim 10 which comprises 50-70% by weight of cyclic oligomers having degrees of polymerization in the range from 2 to 5.
Claim 13
Dependent Claim
18 words
A composition according to claim 11 which contains no more than about 5% by weight of linear oligomers.
Claim 14
Dependent Claim
21 words
A composition according to claim 12 wherein a major proportion of the oligomers have degrees of polymerization up to about 12.
References Cited (Backward Citations)
US3386954A
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US3299948A
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US3274214A
Cited
US3297634A
Cited
US3155683A
Cited
US3422119A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-02-16 | 1990-08-18 | 1991-02-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-16 | 1994-08-18 | 1995-02-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-16 | 1998-08-18 | 1999-02-17 | $7700.00 | Window Closed / Lapsed |