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US4293533A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for producing solid carbon material having high flexural strength

Assignee: Kureha Corp
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Filing: 1977-01-12
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Granted: 1981-10-06
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Expires: 1997-01-12
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Abstract

Abstract Solid carbon material having extremely high flexural strength can be produced by introducing a sufficient amount of functional group to satisfy the undernoted general equation into a pitch having a H/C atomic ratio of 0.8 at most, thereby obtaining precursory carbon material; shaping said precursory carbon material into a desired article without using any binding material; and carbonizing or further graphitizing said article; wherein the general equation is ##EQU1## where, H/C is the hydrogen-to-carbon atomic ratio of the pitch, R is a numeral ranging from 0.2 to 0.3, and f is the percent by weight of at least one of oxygen, sulfur and halogen contained in the total functional groups introduced into the precursory carbon material on the basis of the weight thereof.

Inventors

  • 👤 Kiro Asano
  • 👤 Humio Tamura
  • 👤 Yushi Nezu
  • 👤 Tsuyoshi Saito
  • 👤 Yoshio Kawai

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 18:46
CPC Classifications
D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01F9/145; D01F9/155; C; C01; C01B; C01B32/00; C04; C04B; C04B35/00; C04B35/515; C04B35/52

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 170 words
In a method for producing solid carbon material having a high bending strength and a low porosity which comprises preparing a precursory carbon material having a hydrogen-to-carbon ratio of from 0.4 to 0.6 by the sequential steps: introducing functional groups containing oxygen into a pitch used as a raw material having a maximum hydrogen-to-carbon atomic ratio of 0.8; shaping said precursory carbon material into a desired article without using any binding material; and carbonizing and graphitizing said article after said shaping in an inert atmosphere; the improvement comprising so introducing said functional groups into the pitch so as to satisfy the following equation, ##EQU3## where H/C is the hydrogen-to-carbon atomic ratio of the said pitch, R is a value ranging from 0.2 to 0.3, and f is the percent by weight oxygen introduced into the precursory carbon material on the basis of the weight thereof, whereby the said solid carbon material has a maximum effective porosity of 7 percent and a bending strength of at least 900 kg/cm 2 .
Claim 2
Dependent Claim 170 words
In a method for producing solid carbon material having a high bending strength and a low porosity which comprises preparing a precursory carbon material having a hydrogen-to-carbon ratio of from 0.4 to 0.6 by the sequential steps: introducing functional groups containing oxygen into a pitch used as a raw material having a maximum hydrogen-to-carbon atomic ratio of 0.8; shaping said precursory carbon material into a desired article without using any binding material; and carbonizing and graphitizing said article after said shaping in an inert atmosphere; the improvement comprising so introducing said functional groups into the pitch so as to satisfy the following equation, ##EQU3## where H/C is the hydrogen-to-carbon atomic ratio of the said pitch, R is a value ranging from 0.2 to 0.3, and f is the percent by weight oxygen introduced into the precursory carbon material on the basis of the weight thereof, whereby the said solid carbon material has a maximum effective porosity of 7 percent and a bending strength of at least 900 kg/cm 2 .

References Cited (Backward Citations)

US3558276A Cited
GB1220482A Cited
US3565980A Cited
GB1307392A Cited
US3839515A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1984-10-05 1985-04-06 1985-10-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1988-10-05 1989-04-06 1989-10-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1992-10-05 1993-04-06 1993-10-06 $7700.00 Window Closed / Lapsed

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