Patent US4511625A successfully refreshed from Google Patents.
US4511625A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Physical conversion of latent mesophase molecules to oriented molecules
Assignee: BP Corp North America Inc
•
Filing: 1982-09-30
•
Granted: 1985-04-16
•
Expires: 2002-09-30
Abstract
Abstract A process of spinning a pitch having less than 40% by weight mesophase into a pitch fiber having at least 70% by weight mesophase is described.
Inventors
- 👤 Faramarz Nazem
- 👤 Rostislav Didchenko
- 👤 David Fink
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:24
CPC Classifications
D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01F9/32; D01F9/322; C; C10; C10C; C10C3/00; C10C3/14; D01F9/145; Y; Y10; Y10S; Y10S264/00; Y10S264/19; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/298
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
99 words
A pitch fiber having at least 70% mesophase by weight is produced from a spinneret by the steps comprising selecting a petroleum-derived or coal-derived pitch having a mesophase content of less than 40% by weight according to conventional measurements and having a total content of mesophase-type molecules and latent mesophase molecules greater than 70% by weight; and spinning the pitch into a fiber having a diameter less than about 60 microns by passing said pitch through a porous body positioned in a spinneret channel defined between the inside and outside surfaces of said spinneret to produce said pitch fiber.
Claim 2
Dependent Claim
99 words
A pitch fiber having at least 70% mesophase by weight is produced from a spinneret by the steps comprising selecting a petroleum-derived or coal-derived pitch having a mesophase content of less than 40% by weight according to conventional measurements and having a total content of mesophase-type molecules and latent mesophase molecules greater than 70% by weight; and spinning the pitch into a fiber having a diameter less than about 60 microns by passing said pitch through a porous body positioned in a spinneret channel defined between the inside and outside surfaces of said spinneret to produce said pitch fiber.
Claim 3
Dependent Claim
97 words
A process for producing a continuous pitch fiber having at least 70% mesophase by weight from a spinneret, comprising the steps of selecting a coal-derived or petroleum-derived pitch having a mesophase content of less than 40% by weight according to conventional measurements and having a total content of mesophase-type molecules and latent mesophase molecules greater than 70% by weight; and spinning the pitch into a fiber having a diameter less than about 30 microns by passing said pitch through a porous body positioned in a spinneret channel defined between the inside and outside surfaces of said spinneret.
Claim 4
Dependent Claim
97 words
A process for producing a continuous pitch fiber having at least 70% mesophase by weight from a spinneret, comprising the steps of selecting a coal-derived or petroleum-derived pitch having a mesophase content of less than 40% by weight according to conventional measurements and having a total content of mesophase-type molecules and latent mesophase molecules greater than 70% by weight; and spinning the pitch into a fiber having a diameter less than about 30 microns by passing said pitch through a porous body positioned in a spinneret channel defined between the inside and outside surfaces of said spinneret.
References Cited (Backward Citations)
US3595946A
Cited
US4115527A
Cited
US3959448A
Cited
US3629379A
Cited
US3702054A
Cited
US4066737A
Cited
DE2457991A1
Cited
US4320107A
Cited
US4317809A
Cited
US4301135A
Cited
US4331620A
Cited
US4376747A
Cited
US4356158A
Cited
JPS58136835A
Cited
JPS58136836A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-04-15 | 1988-10-15 | 1989-04-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-15 | 1992-10-15 | 1993-04-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-15 | 1996-10-15 | 1997-04-16 | $7700.00 | Window Closed / Lapsed |