US4806618A
Expired / Lapsed
US
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Aromatic polyethers having biphenylfluorene group
Assignee: Central Glass Co Ltd
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Filing: 1987-11-02
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Granted: 1989-02-21
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Expires: 2007-11-02
Abstract
Abstract Novel aromatic polyethers excellent in heat resistance and soluble in various organic solvents are obtained by introducing 9,9-biphenylfluorene group, optionally together with another divalent aromatic group, into the structural units of a polyether derived from either diphenyl ketone or diphenyl sulfone.
Inventors
- 👤 Yoshio Imai
- 👤 Masaaki Kakimoto
- 👤 Yutaka Maruyama
- 👤 Toshio Koishi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 09:33
CPC Classifications
C; C08; C08G; C08G75/00; C08G75/20; C08G75/23; C08G65/00; C08G65/34; C08G65/38; C08G65/40; C08G65/4012
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
38 words
An aromatic polyether represented by the general formula (1): ##STR8## wherein R represents one 9,9-biphenylfluorene group or at least two divalent aromatic groups including at least one 9,9-biphenylfluorene group, and n is an integer from 1 to 200.
Claim 2
Dependent Claim
38 words
An aromatic polyether represented by the general formula (1): ##STR8## wherein R represents one 9,9-biphenylfluorene group or at least two divalent aromatic groups including at least one 9,9-biphenylfluorene group, and n is an integer from 1 to 200.
Claim 3
Dependent Claim
37 words
An aromatic polyether according to claim 1, wherein said R represents one 9,9-biphenylfluorene group and another divalent aromatic group selected from the group consisting of phenylene group, biphenylene group, 2,2'-diphenylenepropane group, 2,2'-diphenylenehexafluoropropane group, and diphenylene ketone group.
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) | 1992-02-21 | 1992-08-22 | 1993-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-02-21 | 1996-08-22 | 1997-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-02-21 | 2000-08-22 | 2001-02-21 | $7700.00 | Window Closed / Lapsed |