EP0168639A2
Expired / Lapsed
EP
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Pitch-based carbon of graphite fiber and process for preparation thereof
Assignee: Teijin Ltd
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Filing: 1985-06-13
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Granted: —
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Expires: 2005-06-13
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'. 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, 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
EP
Data Source
google_patents
Last Synchronized
2026-10-28 19:15
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: 36
Claim 1
Independent Claim
30 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/mm2.
Claim 2
Dependent Claim
30 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/mm2.
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
28 words
A pitch-based carbon fiber as set forth in claim 1, having a strength of at least 400 kg/mm2 and a modulus of at least 15 T/mm 2 .
Claim 9
Dependent Claim
18 words
A pitch-based graphite fiber as set forth in claim 1, having a modulus of at least 30 T/mm2.
Claim 10
Dependent Claim
53 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 A, as measured for a fiber carbonized at 1300°C, and having a tensile strength of at least 550 kg/mm and a modulus of 20 T/mm 2 .
Claim 11
Dependent Claim
97 words
A process for preparing a pitch-based carbon or graphite fiber having a leafy lamella arrangement in at least 30% of the fiber cross-section, which comprises 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, 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.
Claim 12
Dependent Claim
97 words
A process for preparing a pitch-based carbon or graphite fiber having a leafy lamella arrangement in at least 30% of the fiber cross-section, which comprises 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, 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.
Claim 13
Dependent Claim
17 words
A process as set forth in claim 10, wherein the spinning hole consists of a single slit.
Claim 14
Dependent Claim
18 words
A process as set forth in claim 10, wherein the spinning hole consists of a plurality of slits.
Claim 15
Dependent Claim
27 words
A process as set forth in claim 12, wherein the spinning hole consists of 3 to 6 slits radially extending equiangularly with one point being the center.
Claim 16
Dependent Claim
20 words
A process as set forth in claim 10, wherein the central line of the spinning hole is a straight line.
Claim 17
Dependent Claim
20 words
A process as set forth in claim 10, wherein the central line of the spinning hole is a curved line.
Claim 18
Dependent Claim
28 words
A process as set forth in claim 10, wherein the central line of the spinning hole consists of a combination of a straight line and a curved line.
Claim 19
Dependent Claim
21 words
A process as set forth in claim 10, wherein the optically anisotropic pitch has an optical anisotropy of at least 80%.
Claim 20
Dependent Claim
21 words
A process as set forth in claim 10, wherein the optically anisotropic pitch has a melting point of 250°C to 350°C.
Claim 21
Dependent Claim
24 words
A process as set forth in claim 10, wherein the quinoline-soluble component content of the optically anisotropic pitch is at least 30% by weight.
Claim 22
Dependent Claim
29 words
A process as set forth in claim 10, wherein the spinning temperature at the melt-spinning step is higher by 40°C to 100°C than the melting point of the pitch.
Claim 23
Dependent Claim
94 words
A process as set forth in claim 10, wherein the optically anisotropic pitch is a substantially homogeneous optically anisotropic pitch having a melting point of 260°C to 320°C, which consists completely of optically anisotropic phase or consists essentially of continuous optically anisotropic phase wherein the optically anisotropic phase contains a spherical optically isotropic phase, the spherical bodies are contained in an amount not more than 15% and in a number not less than 100/mm 2 and have an average diameter not larger than 15 um, each having a diameter not larger than 100 µm.
Claim 24
Dependent Claim
25 words
A process as set forth in claim 21, wherein the average diameter of the spherical optically isotropic phase bodies is not larger than 10 µm.
Claim 25
Dependent Claim
20 words
A process as set forth in claim 21, wherein the spherical optically isotropic phase content is not more than 10%.
Claim 26
Dependent Claim
21 words
A process as set forth in claim 21, wherein the melting point of the optically anisotropic pitch is 270°C to 300°C.
Claim 27
Dependent Claim
81 words
A process as set forth in claim 21, wherein the substantially homogeneous optically anisotropic pitch is prepared through the first step of treating a starting pitch with an organic solvent to collect a solvent-insoluble fraction, the second step of subjecting the solvent-insoluble fraction to the hydrogenation treatment, the third step of filtering the hydrogenaticn product, and the fourth step of removing the solvent from the filtrate and heat-treating the residue at a temperature higher than 400°C under reduced pressure atmospheric pressure.
Claim 28
Dependent Claim
33 words
A process as set forth in claim 25, wherein in the first step, the starting pitch is treated with an organic solvent system having a solubility coefficient of 8 to 10 at 25°C.
Claim 29
Dependent Claim
68 words
A process as set forth in claim 25, wherein in the second step, 100 to 300 parts by weight of a mixture of hydrogenated fused polycyclic aromatic compounds having at least 2 rings is added to 100 parts of a solvent-insoluble fraction obtained from a starting pitch and the obtained mixture is subjected to a hydrogenation treatment at a temperature of 400°C to 500°C under an autogeneous pressure.
Claim 30
Dependent Claim
63 words
A process as set forth in claim 25, wherein in the second step, 100 to 300 parts by weight of a hydrogenated nitrogen-containing aromatic compound or a mixture thereof is added to 100 parts by weight of a solvent-insoluble fraction obtained from a starting pitch and the obtained mixture is subjected to a hydrogenation treatment at 400°C to 500°C under an autogeneous pressure.
Claim 31
Dependent Claim
80 words
A process as set forth in claim 25, wherein in the second step, 100 to 300 parts by weight of a mixture of fused polycyclic aromatic compounds having at least 2 rings is added to 100 parts by weight of a solvent-insoluble fraction obtained from a starting pitch and the obtained mixture is hydrogenated in the presence or absence of a hydrogenation catalyst under a hydrogen pressure of at least 50 kg/cm 2 at a temperature of 350°C to 500°C.
Claim 32
Dependent Claim
69 words
A process as set forth in claim 25, wherein in the second step, 100 to 300 parts by weight of a nitrogen-containing aromatic compound to 100 parts by weight of a solvent-insoluble fraction obtained from a starting pitch and hydrogenating the obtained mixture in the presence or absence of a hydrogenation catalyst under a hydrogen pressure of at least 50 kg/cm 2 at a temperature of 350°C to 500°C.
Claim 33
Dependent Claim
83 words
A process as set forth in claim 10, wherein the optically anisotropic pitch to be spun is prepared by treating an optically isotropic pitch having a quinoline-insoluble component content of not more than 5% by weight with an organic solvent system having a solubility coefficient of about 8.0 to 10 at 25°C and heat treating the organic solvent-insoluble component at a temperature of 230°C to 450°C to convert it to a pitch having an optically anisotropic phase content of not less than 75%.
Claim 34
Dependent Claim
31 words
A process as set forth in claim 31, wherein the organic solvent system is benzene, toluene or a solvent mixture containing not less than 60% by volume of benzene and/or toluene.
Claim 35
Dependent Claim
39 words
A process as set forth in claim 31, wherein the organic solvent system is used in an amount of 5 to 150 ml per g of the pitch and the solvent treatment is carried out at 20°C to 200°C.
Claim 36
Dependent Claim
109 words
A process as set forth in claim 10, wherein the substantially homogeneous optically anisotropic pitch to be spun is prepared by denaturating an optically anisotropic pitch with an organic solvent system having a solubility coefficient of about 8.0 to 10 and treating the organic solvent-insoluble component with a mixture of unhydrogenated fused polycyclic aromatic compounds having at least 2 rings or an unhydrogenated nitrogen-containing aromatic compound or a mixture of such compounds in a nitrogen atmosphere at a temperature of 350 to 500°C, filtering the denaturation product, removing the solvent from the filtrate, and heat-treating the residue at a temperature higher than 400°C under reduced pressure or atmospheric pressure.
References Cited (Backward Citations)
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