US4465585A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cholesteric mesophase pitch
Assignee: BP Corp North America Inc
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Filing: 1982-03-30
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Granted: 1984-08-14
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Expires: 2002-03-30
Abstract
Abstract A cholesteric mesophase pitch is disclosed along with methods for producing the same.
Inventors
- 👤 Irwin C. Lewis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:25
CPC Classifications
D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01F9/145; C; C10; C10C; C10C3/00
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
58 words
A cholesteric pitch produced by combining a mesophase pitch having ellipsoidal molecules with a compatible optically active compound, said mesophase pitch being produced by reacting a weak Lewis acid with an aromatic hydrocarbon containing at least two condensed rings in the presence of a polar solvent of the aromatic hydrocarbon which solvent is non-reactive with said Lewis acid.
Claim 2
Dependent Claim
58 words
A cholesteric pitch produced by combining a mesophase pitch having ellipsoidal molecules with a compatible optically active compound, said mesophase pitch being produced by reacting a weak Lewis acid with an aromatic hydrocarbon containing at least two condensed rings in the presence of a polar solvent of the aromatic hydrocarbon which solvent is non-reactive with said Lewis acid.
Claim 3
Dependent Claim
23 words
The cholesteric pitch of claim 1, wherein the content of said optically active compound is from about 1% to about 2% by weight.
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) | 1987-08-14 | 1988-02-13 | 1988-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-08-14 | 1992-02-13 | 1992-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-08-14 | 1996-02-13 | 1996-08-14 | $7700.00 | Window Closed / Lapsed |