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US4628001A Expired / Lapsed US ⏱️ 0.0 years remaining

Pitch-based carbon or graphite fiber and process for preparation thereof

Assignee: REED CLAUDE A
•
Filing: 1985-04-03
•
Granted: 1986-12-09
•
Expires: 2005-04-03
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Abstract

Abstract A pitch-based carbon or graphite fiber having a leafy lamella arrangement in at least 30% of the fiber cross-sectional area and having a tensile strength of at least 300 kg/mm 2 . The fiber is prepared by melt-spinning an optically anisotropic pitch having an optically anisotropic phase content of at least 50% through a spinneret in which at least one central line distance in a spinning hole simultaneously satisfies the following requirements I and II, Ln<10 I 1.5≦Ln/Wn≦20 II wherein Ln stands for central line distances in mm in the spinning hole and Wn stands for wetted perimeter widths in mm in the spinning hole, and infusibilizing and carbonizing the formed pitch fiber.

Inventors

  • 👤 Hideharu Sasaki
  • 👤 Toru Sawaki
  • 👤 Yoshiaki Yoshioka

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 17:37
CPC Classifications
D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01D; D01D5/00; D01D5/253; D01F9/145; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2918; Y10T428/2973; Y10T428/30

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 32 words
A pitch-based carbon or graphite fiber having a leafy lamella arrangement in at least 30% of the fiber cross-sectional area and having a tensile strength of at least 300 kg/mm 2 .
Claim 2
Dependent Claim 32 words
A pitch-based carbon or graphite fiber having a leafy lamella arrangement in at least 30% of the fiber cross-sectional area and having a tensile strength of at least 300 kg/mm 2 .
Claim 3
Dependent Claim 18 words
A pitch-based carbon or graphite fiber as set forth in claim 1, having a substantially circular cross-sectional shape.
Claim 4
Dependent Claim 17 words
A pitch-based carbon or graphite fiber as set forth in claim 1, having an ellipsoidal cross-sectional shape.
Claim 5
Dependent Claim 17 words
A pitch-based carbon or graphite fiber as set forth in claim 1, having a multiangular cross-sectional shape.
Claim 6
Dependent Claim 17 words
A pitch-based carbon or graphite fiber as set forth in claim 1, having a multilobar cross-sectional shape.
Claim 7
Dependent Claim 22 words
A pitch-based carbon or graphite fiber as set forth in claim 1, having two to eight leafy lamella arrangements in the cross-section.
Claim 8
Dependent Claim 29 words
A pitch-based carbon fiber as set forth in claim 1, having a strength of at least 400 kg/mm 2 and a modulus of at least 15 T/mm 2 .
Claim 9
Dependent Claim 20 words
A pitch-based graphite fiber as set forth in claim 1, having a modulus of at least 30 T/mm 2 .
Claim 10
Dependent Claim 55 words
A pitch-based carbon fiber as set forth in claim 1, having an orientation angle of 20° to 35° and a crystalline size of 18 to 35 Å, as measured for a fiber carbonized at 1300° C., and having a tensile strength of at least 550 kg/mm 2 and a modulus of 20 T/mm 2 .

References Cited (Backward Citations)

US2129825A Cited
US4005183A Cited
US4208267A Cited
US4184942A Cited
US4376747A Cited
US4397830A Cited
US4521294A Cited
US4460557A Cited
US4469667A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-12-08 1990-06-09 1990-12-09 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-12-08 1994-06-09 1994-12-09 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-12-08 1998-06-09 1998-12-09 $7700.00 Window Closed / Lapsed

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