EP0084237A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Process for the manufacture of carbon fibers and feedstock therefor
Assignee: Ashland LLC
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Filing: 1982-12-14
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Granted: —
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Expires: 2002-12-14
Abstract
Abstract Disclosed herein is an improved pitch for making readily stabilizable. substantially nonmesophasic carbon fibers. The pitch has a softening point of about 250°C(480°F) or above and is produced from an unoxidized thermal petroleum pitch by selectively reducing or eliminating a portion of the low molecular weight materials in a very short period of time so that the tendency to produce mesophase pitch is eliminated or reduced and so that the chemical integrity of the components of the higher molecular weight fractions is preserved as much as possible. Also disclosed is a method of producing carbon fibers therefrom and rovings or mats from such fibers.
Inventors
- 👤 William R. Sawran
- 👤 John W. Newman
- 👤 Clifford Ward
- 👤 Frank H. Turrill
- 👤 Norman W. Hall
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 06:11
CPC Classifications
D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01F9/145; D01F9/155; C; C10; C10C; C10C3/00; C10C3/002; D01F9/32; D01F9/322
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
97 words
A petroleum pitch, suitable for use in the manufacture of carbon fibers, said pitch comprising an aromatic enriched petroleum pitch characterised by an alpha hydrogen content based on the total moles of hydrogen present in the pitch of from 20-40%, a softening point of at least 247°C, a xylene insolubles content of from 15% to 4096 by weight, a quinoline insolubles content of from 0% to 5.0% by weight, a sulfur content from 0.1 to 4% by weight, a coking value of from 65 to 90 weight % and a mesophase content not exceeding 5% by weight.
Claim 2
Dependent Claim
97 words
A petroleum pitch, suitable for use in the manufacture of carbon fibers, said pitch comprising an aromatic enriched petroleum pitch characterised by an alpha hydrogen content based on the total moles of hydrogen present in the pitch of from 20-40%, a softening point of at least 247°C, a xylene insolubles content of from 15% to 4096 by weight, a quinoline insolubles content of from 0% to 5.0% by weight, a sulfur content from 0.1 to 4% by weight, a coking value of from 65 to 90 weight % and a mesophase content not exceeding 5% by weight.
Claim 3
Dependent Claim
29 words
A pitch according to Claim 1, characterised by a softening point of at least 265°C and a beta hydrogen content, based on total hydrogen of from 2% to 15%.
Claim 4
Dependent Claim
26 words
A pitch according to Claim 1 or 2, characterised by an xylene insolubles content of from 1.6 to 2.8%, and a quinoline insolubles content below 1.0%.
Claim 5
Dependent Claim
15 words
A pitch according to Claim 3, characterised by, a softening point of at least 290°C.
Claim 6
Dependent Claim
15 words
A carbon fiber produced from a pitch as claimed in any one of Claims 1-4.
Claim 7
Dependent Claim
16 words
A carbon fiber according to claim 5, characterised by a diameter in the range 10-14 microns.
Claim 8
Dependent Claim
67 words
A process for manufacturing carbon fibers, which comprises forming pitch fibers from a pitch as claimed in. any one of Claims 1-4, heating the pitch fibers in an oxidizing environment to a first temperature that is from 6 to 11°C below their glass transition temperature and then increasing the temperature to a higher temperature to render the pitch fibers infusible, and thereafter carbonizing or graphitizing the fibers.
Claim 9
Dependent Claim
24 words
A process according to Claim 7, wherein the first temperature is about 175 0 C and the higher temperature is above 285 0 C.
Claim 10
Dependent Claim
20 words
A process according to Claim 7 or 8, wherein the pitch fibers are formed by melt blowing the pitch feed.
Claim 11
Dependent Claim
29 words
A process according to any one of Claims 7-9, wherein the pitch fibers are subsequently carbonized by heating them in an inert atmosphere to a temperature of about 1200°C.
Claim 12
Dependent Claim
29 words
A process according to any one of claims 7-9, wherein the pitch fibers are subsequently graphitized by heating them in an inert atmosphere to a temperature of about 3000°C.
Claim 13
Dependent Claim
63 words
A process fnr preparing a pitch as claimed in any one of Claims 1-4 which comprises treating an unoxidized or unmodified thermal petroleum pitch having a softening point of about 75 to 130°C and containing a minor amount of aromatic insolubles to effect the removal therefrom at least 25% of molecular species contained in said pitch and having molecular weights below about 550.
Claim 14
Dependent Claim
27 words
A process according to Claim 12, wherein the low molecular weight species are removed by heating the unoxidized or unmodified thermal petroleum pitch in a wiped-film evaporator.
Claim 15
Dependent Claim
25 words
A process according to Claim 13, wherein the residence time in said evaporator is from 5 to 15 seconds and the temperature is about 375°C.
Claim 16
Dependent Claim
162 words
A process for the product of pitch fibers which are readily con- vertable precursors to carbon fibers and/or graphite fibers, characterised by the steps of: (a) preparing a petroleum pitch from decant oil, slurry oil, or other residuum, said pitch containing from 20% to 40% alpha hydrogens and from 2 to 15% of beta hydrogen atoms, based on the total weight of the hydrogen in said pitch, a softening point of at least about 250°C, an xylene insolubles content of from 15 to 40% by weight, a quinoline insolubles content of from 0 to 5% by weight, a sulfur content of from 0.1 to 4% by weight, a coking value of from 65 to 90 wt% and a mesophase content not exceeding about 5% by weight. (b) melting said pitch and forming fibers therefrom; and (c) stabilizing said fibers by contact with air or other oxidant for a time less than about 100 minutes at a temperature above about 285 Q C.
Claim 17
Dependent Claim
162 words
A process for the product of pitch fibers which are readily con- vertable precursors to carbon fibers and/or graphite fibers, characterised by the steps of: (a) preparing a petroleum pitch from decant oil, slurry oil, or other residuum, said pitch containing from 20% to 40% alpha hydrogens and from 2 to 15% of beta hydrogen atoms, based on the total weight of the hydrogen in said pitch, a softening point of at least about 250°C, an xylene insolubles content of from 15 to 40% by weight, a quinoline insolubles content of from 0 to 5% by weight, a sulfur content of from 0.1 to 4% by weight, a coking value of from 65 to 90 wt% and a mesophase content not exceeding about 5% by weight. (b) melting said pitch and forming fibers therefrom; and (c) stabilizing said fibers by contact with air or other oxidant for a time less than about 100 minutes at a temperature above about 285 Q C.
Claim 18
Dependent Claim
131 words
A process according to Claim 15 characterised in that said pitch is prepared by the steps of: (a) thermally processing clarified slurry oil or cycle oil from which substantially all paraffins have been removed in a fluid catalytic cracking step and/or by extraction to produce a highly aromatic oil boiling at about 315 to 540°C. (b) thermally cracking this highly aromatic oil at temperatures and pressures and for times sufficient to produce a thermally cracked petroleum pitch with a softening point of about 38.7 to about 126.7 o C; and . (c) subjecting the product of the preceding step to vacuum distillation at from about 0.1 to about 0.5 torr (13.3 to 66.5 Pa) temperature of about 710°F (377°C) for a time in the range of about 5 to 15 seconds.
Claim 19
Dependent Claim
22 words
A process according to Claim 15 or Claim 16 characterised by the additional step of carbonizing or graphitizing the stabilized pitch fibers.
References Cited (Backward Citations)
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