EP0279687B1 - Graphitfaser - Google Patents

Graphitfaser Download PDF

Info

Publication number
EP0279687B1
EP0279687B1 EP19880301424 EP88301424A EP0279687B1 EP 0279687 B1 EP0279687 B1 EP 0279687B1 EP 19880301424 EP19880301424 EP 19880301424 EP 88301424 A EP88301424 A EP 88301424A EP 0279687 B1 EP0279687 B1 EP 0279687B1
Authority
EP
European Patent Office
Prior art keywords
fiber
graphite
gpa
elastic modulus
weight
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP19880301424
Other languages
English (en)
French (fr)
Other versions
EP0279687A2 (de
EP0279687A3 (de
Inventor
Keizo Ono
Kenji Mitsuyasu
Mototada Hukuhara
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toray Industries Inc
Original Assignee
Toray Industries Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=12450302&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=EP0279687(B1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Toray Industries Inc filed Critical Toray Industries Inc
Publication of EP0279687A2 publication Critical patent/EP0279687A2/de
Publication of EP0279687A3 publication Critical patent/EP0279687A3/de
Application granted granted Critical
Publication of EP0279687B1 publication Critical patent/EP0279687B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
    • D01F9/00—Artificial filaments or the like of other substances; Manufacture thereof; Apparatus specially adapted for the manufacture of carbon filaments
    • D01F9/08—Artificial filaments or the like of other substances; Manufacture thereof; Apparatus specially adapted for the manufacture of carbon filaments of inorganic material
    • D01F9/12—Carbon filaments; Apparatus specially adapted for the manufacture thereof
    • D01F9/14—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments
    • D01F9/20—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments from polyaddition, polycondensation or polymerisation products
    • D01F9/21—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments from polyaddition, polycondensation or polymerisation products from macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
    • D01F9/22—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments from polyaddition, polycondensation or polymerisation products from macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds from polyacrylonitriles

Definitions

  • the present invention relates to a graphite fiber. More particularly, it relates to a graphite fiber, which is valuable for a composite material having a plastic as a matrix and having a high compression strength.
  • a carbon fiber is obtained by calcining an organic fiber of cellulose, polyacrylonitrile or pitch at a high temperature in an inert gas.
  • the final calcination temperature is higher than 1,000°C, and especially in the case of a graphite fiber, the final calcination temperature sometimes exceeds 2,000°C.
  • Carbon can take two crystal structures, i.e., a diamond structure and a graphite structure.
  • the carbon fiber has a graphite structure comprising laminated net planes. This graphite structure has a much higher anisotropy than an ordinary crystal structure of a metal, and the mechanical characteristics in the direction of the fiber axis are enhanced by orienting the net planes selectively in the direction of the fiber axis.
  • the object of the present invention is to provide a carbon fiber valuable as a composite material having a high compression strength by rationalizing the inner structure of the carbon fiber, contrary to the conventional technique.
  • the desired fiber of the present invention is a graphite fiber having an elastic modulus of at least 340 GPa. This is because in the case of, for example, a polyacrylonitrile carbon fiber, as the elastic modulus is increased, the compression strength of the composite material is drastically reduced. Furthermore, as pointed out hereinbefore, although it is considered that the characteristics of a carbon fiber having a high elastic modulus will enable practical use thereof as a thin structural material, expansion of this use is often obstructed by the poor compression strength.
  • a primary object of the present invention is to provide a graphite fiber which is valuable for a composite material having an improved compression strength and an expanded degree of freedom of design.
  • a graphite fiber having an elastic modulus E of 340 to 680 GPa wherein the crystal size L C ( ⁇ ) determined from the half value width of the diffraction to the (002) plane of carbon network by the wide-angle X-ray diffraction satisfies the requirement represented by the following formula (I) relative to the elastic modulus E (GPa) of the fiber: L c 3 ⁇ 0.918 x 10 3 E - 3 x 10 5 and the microvoid radius determined from the small-angle X-ray scattering defined in the text of the specification is not larger than 20 ⁇ .
  • the present invention provides a process for making a graphite fiber, which comprises the steps of:
  • the crystal of a carbon has a structure comprising laminated carbon network and a very high anisotropy. Accordingly, it is easily understood that the crystal is very strong against a tensile force but very weak against shear buckling. An increase of this anisotropy is most effective for a manifestation of the elastic modulus, but it is obvious that in view of the object of the present invention, development of the anisotropy is not preferred. Accordingly, it is necessary to manifest the elasticity while controlling the anisotropy. As pointed out hereinafter, it is necessary to form a dense structure by reducing the crystal size as much as possible relative to the elastic modulus, while controlling the formation of microvoids.
  • crystal size and microvoid radius referred to in the present invention are determined according to the following methods.
  • microvoid size is determined from the small-angle X-ray scattering pattern according to the following procedures.
  • the sample In the determination of the small-angle scattering, the sample is arranged in parallel so that scattering in the direction vertical to the fiber axis can be measured, is fixed by a collodion solution, and is set so that the fiber axis is in parallel to the longitudinal direction of the X-ray slit.
  • An X-ray generator (Model RO-200 supplied by Rigaku Denki) and a CuK ⁇ ray monochromatized by a graphite monochrometer are used.
  • the tensile strength, flexural strength, and compression strength of a composite reinforced with the graphite fiber of the present invention are determined according to the methods of ASTM 3039-76, ASTM 790-80, and ASTM 3410-75, respectively.
  • a graphite fiber which satisfies not only the above-mentioned requirements but also the requirement of the so-determined compression strength ⁇ c (GPa) of the graphite fiber-reinforced composite, which is represented by the following formula (II), relative to the elastic modulus E (GPa): ⁇ c ⁇ 1.715 - 1.5 x 10 -3 E
  • This graphite fiber-reinforced composite has a very high compression strength. Therefore, the thickness of the composite material can be remarkably reduced and the degree of freedom of design can be greatly increased in the composite material.
  • the first requirement of the present invention is that the crystal size must be reduced to a value lower than a specific value.
  • the crystal size of graphite is most influenced by the maximum temperature of graphitization. More specifically, a product obtained at a low graphitization temperature has a small crystal size, and accordingly, the graphitization must be carried out at as low a temperature as possible.
  • a desired elastic modulus should be obtained, and therefore, a precursor must have a structure which can easily be graphitized to have high elastic modulus even at a low graphitization temperature.
  • the amount of a comonomer to be copolymerized with acrylonitrile in the preparation of the starting polymer is important. Namely, as the amount of the comonomer is increased, the glass transition point is lowered and thermal relaxation easily occurs in the molecule chain, and the orientation structure of the starting fiber is disturbed, especially at the oxidation step, with the result that it becomes difficult to increase the elastic modulus. Therefore, the amount of the copolymer is controlled to a value lower than a certain value. If the comonomer is more bulky than the acrylonitrile, that is, the molecular weight of the comonomer is higher than that of acrylonitrile, this relaxation effect is high.
  • the weight ratio is more appropriate than the molar ratio for defining the amount of the comonomer.
  • the amount of the comonomer units is in the range of 0.05 to 8% by weight, preferably 0.05 to 4% by weight, based on weight of the copolymer. If the amount of the comonomer is smaller than 0.05% by weight, it is difficult to obtain a precursor fiber having an iodine adsorption amount of not larger than 3% by weight.
  • the graphite fiber of the present invention is characterized in that the fiber is highly dense, and to this end, preferably the starting fiber already has a dense structure.
  • the denseness of the precursor fiber can be evaluated based on the iodine adsorption amount described below.
  • aqueous solution containing 50 g of iodine, 10 g of 2,4-dichlorophenol, 90 g of acetic acid and 100 g of potassium iodide is prepared.
  • 100 ml of the aqueous solution is immersed 0.5 g of a dry sample, and the adsorption treatment is carried out at 60 ⁇ 0.5°C for 50 minutes. After the treatment, the sample is washed in running water for 30 minutes, and centrifugal dehydration is carried out.
  • the dehydrated sample is dissolved by heating in 100 ml of dimethyl-sulfoxide, the iodine concentration is determined by the potentiometric titration using a 1/10 N aqueous solution of silver nitrate, and the amount of iodine adsorbed in the dry sample is calculated.
  • the iodine adsorption amount corresponds to the quantity of microvoids present in the precursor fiber or the structurally coarse portion. Accordingly, to obtain a dense graphite fiber, preferably the precursor fiber per se is dense and the iodine absorption amount of the precursor fiber is small. To attain the object of the present invention, the iodine -absorption amount should be not larger than 3% by weight, preferably not larger than 2% by weight.
  • the iodine absorption amount of the precursor fiber depends mainly on such fiber-forming conditions as spinning, coagulating and drawing, and the kind of oiling agent applied. More specifically, at the coagulation in the wet spinning process, the size of the spinneret orifice or the spinning speed is controlled so that the draft is as low as possible. For this purpose, a higher concentration of the spinning solution is preferred, and the dry jet wet spinning method in which an extruded fiber is travelled in the air and then in a coagulation bath is preferable to the wet spinning method.
  • the substantial draft ratio is preferably 6 or less.
  • the drawing is carried out in the wet state before drying while maintaining the draw ratio and temperature at levels as high as possible within the range where sticking does not occur among filaments.
  • the draw ratio is preferably at least 10 times the original length.
  • An oiling agent applied before drying is likely to diffuse and permeate into the interior of the fiber in the swollen state, to reduce the denseness. Accordingly, an oiling agent having a high molecular weight is selected.
  • a silicone oiling agent having a high water repellency is especially preferred.
  • Conversion of the so-obtained dense acrylic fiber to a graphite fiber by calcination and graphitization is accomplished according to the conventional technique. Namely, the acrylic fiber is oxidized, a carbonization treatment is carried out at a temperature of 400 to 1,500°C in an inert atmosphere, and a graphatization treatment is carried out at a higher temperature. In this process, the following conditions are adopted.
  • the acrylic fiber is heated in an oxidative atmosphere containing at least 15% by volume of oxygen, preferably in air, maintained at 200 to 300°C, while being kept under tension at least in the first half stage of the oxidation treatment, to cause cyclization and oxidation of polyacrylonitrile, whereby the heat resistance is improved.
  • the fiber is elongated under tension in the first half stage of the oxidation treatment, the fiber may be either elongated under tension or kept at a constant length in the second half stage thereof. It is known that cyclized and oxidized polyacrylonitrile shows a moisture-absorbing property caused by a chemical change of the structure, and the quantity of absorbed water is an indicator of the degree of oxidation.
  • the degree of oxidation is controlled to a certain low level.
  • Japanese Examined Patent Publication No. 44-21,175 teaches that preferably the oxidizing treatment is carried out so that oxygen permeates substantially completely into the interior of the precursor, as the result of investigation by the present inventors it was found that, if permeation of oxygen is excessive, the formation of microvoids at the subsequent carbonization step is conspicuous and the specific gravity is reduced, although the reason for this is not clear. Therefore, an excessive permeation of oxygen is not preferable.
  • the amount of water adsorbed in the oxidized fiber can be determined according to the following procedures. Namely, the oxidized fiber is allowed to stand at room temperature for about 16 hours in a desiccator, the lower portion of which is charged with an aqueous solution of ammonium sulfate containing a co-present solid phase, and when the equilibrium adsorption is attained, the amount of water is calculated according to the weight method.
  • this value of the amount of adsorbed water reaches ten and some%, but to attain the object of the present invention, this value is not larger than 7% by weight.
  • the lower limit of this value is not particularly critical, but if the value is too small, the yield of carbonization is reduced and the cost is increased. If the value is further reduced, yarn breakage occurs at the carbonization step and the production is hindered. Therefore, preferably the value is about 3 to about 4% or more.
  • a highly oriented fiber which has been drawn at a high draw ratio is generally used as the precursor fiber for a carbon fiber, but if this orientation is relaxed, the intended object cannot be attained. Since relaxation of the orientation is especially conspicuous at the initial stage of the oxidizing treatment, prevention of this relaxation is important.
  • the graphite crystal of the obtained carbonized fiber is influenced by the orientation of the starting fiber, but the orientation degree of the graphite structure is important for the carbon fiber.
  • an oxidized fiber if X-ray diffractometry is carried out, a diffraction pattern corresponding to the carbon network is already observed because of the cyclized chain structure of the nitrile group.
  • the orientation degree of the oxidized fiber must be high.
  • the temperature, tension and atmosphere adopted for the oxidizing treatment As process factors having an influence on the value of the orientation degree of the oxidized fiber, there can be mentioned the temperature, tension and atmosphere adopted for the oxidizing treatment. If the temperature is high, the orientation of polyacrylonitrile is relaxed prior to cyclization and good results cannot be obtained. Preferably, the tension is maintained at as high a level as possible. If the oxygen concentration in the oxidizing treatment atmosphere is lower than 15%, an oxidizing fiber having a high orientation degree cannot be obtained.
  • the orientation degree of the precursor fiber should be high and a precursor fiber having a fine single fiber denier, preferably one denier or less, should be used.
  • the amount of the comonomer should be controlled to as low a level as possible.
  • the so-obtained oxidized fiber is carbonized and graphitized according to customary procedures.
  • the carbonization is carried out at a temperature of 400 to 1,500°C, preferably 800 to 1,500°C in an inert atmosphere.
  • the graphitization is carried out at a highest temperature of 2,200 to 2,800°C in an inert atmosphere.
  • the adoption of conditions relaxing the orientation should be avoided at the carbonizing and graphitizing steps. Namely, the tension should be maintained at as high a level as possible at each step, and if the above-mentioned oxidized fiber is used according to the present invention, a graphite fiber having a high elastic modulus can be obtained at a lower temperature than the temperatures adopted in the conventional techniques.
  • the graphite fiber of the present invention is structurally characterized by a small crystal size and a reduced number of microvoids.
  • the compression strength is drastically increased, and compared with the conventional graphite fibers, the compression strength of the composite is greatly improved without a reduction of the elastic modulus.
  • the mechanical characteristics are well-balanced, and the thickness and weight of the composite can be reduced.
  • An acrylonitrile polymer comprising 99% by weight of acrylonitrile and 1% by weight of methacrylic acid was prepared by conducting the polymerization in a dimethylsulfoxide (hereinafter referred to as "DMSO") according to customary procedures to obtain a solution of a polymer having an [ ⁇ ] of 1.8 (the viscosity of the solution was 600 poise measured at 45°C).
  • DMSO dimethylsulfoxide
  • the coagulated fiber was washed with water and drawn in hot water, an oiling agent composed mainly of aminosiloxane was applied to the fiber, and the fiber was heat-treated under dry conditions whereby water was removed from the applied oiling agent and the fiber was densified. Then, the fiber was drawn in steam maintained at a pressure of 5.5 kg/cm ⁇ G at a total draw ratio of 12.4 to obtain a precursor fiber having a single fiber fineness of 0.7 d. It was found that the precursor fiber had a strength of 0.77 GPa and an elongation of 11.8%, and the iodine absorption was 1.2% by weight.
  • the orientation degree determined by X-ray diffractometry was 91.4%.
  • the obtained precursor fiber was subjected to an oxidation treatment under tension in air heated at 240°C, at a stretch ratio of 1.08 for 5 minutes, and the fiber was further subjected to an oxidation treatment in heated air having a temperature gradient such that the temperature was gradually elevated from 250°C to 270°C at a constant length.
  • the fiber was kept under tension at least in the first half stage of the oxidation.
  • the water content in the obtained oxidized fiber was 5.8%, and the degree of orientation of the pre-graphite structure corresponding to the carbon network by X-ray diffractometry was 82.3%.
  • the so-obtained oxidized fiber was carbonized under a tension such that a shortening of the fiber length in a carbonizing furnace did not occur.
  • the carbonizing furnace used was sealed with a nitrogen atmosphere, and had a temperature gradient such that the temperature was elevated from 400°C to 1,300°C.
  • the carbonized fiber was graphitized at a highest temperature of 2,450°C.
  • the strength characteristics of the obtained graphite fiber were determined by the impregnated strand method according to JIS R-7601. It was found that the strength was 4.1 GPa and the elastic modulus was 450 GPa. Thus, it was confirmed that a graphite fiber having a very high strength was obtained.
  • the specific gravity of the obtained fiber was 1.84, the orientation degree of the carbon network determined by the X-ray diffractometry was 91.0%, and the crystal size (L c ) ) was 44 ⁇ .
  • the microvoid radius calculated from the small-angle scattering was 16 ⁇ .
  • the so-obtained graphite fiber had a relatively small crystal size and a small microvoid radius and therefore the graphite fiber was structurally dense.
  • test pieces of a composite material having a fiber content of about 60% were prepared according to customary procedures, and the obtained composite was evaluated.
  • the tensile strength was 2.2 GPa
  • the flexural strength was 1.4 GPa
  • the compression strength was 1.2 GPa. Accordingly, it was confirmed that the compression strength of the composite material was very high, as compared with the compression strength of a composite of conventional graphitized fibers.
  • precursor fibers were prepared according to the wet spinning method while changing the substantial draft of the spun fiber by changing the extrusion orifice diameter in the range of from 0.05 to 0.075 mm in 6,000 orifices as a whole, and the coagulation and take-up speeds.
  • the substantial draft referred to herein means the ratio V i /V f of the take-up speed V i under coagulation conditions to the free linear extrusion speed V f .
  • the graphitizing temperature was controlled in each run so that the elastic modulus was about 450 GPa.
  • L c 3 should be equal to or smaller than 114 x 103, that is, the crystal size (L c ) should be equal to or smaller than 48.5 ⁇ . It is seen that, when the precursor fiber has a low denseness and a large amount of iodine absorption, the elastic modulus is difficult to increase and the graphitizing temperature should be elevated, resulting in the formation of a graphite fiber having a large L c value and a large microvoid size, and consequently, in a reduction of the compression strength of the composite.
  • graphite fibers having a different elastic modulus as shown in Table 2 and Fig. 1, were prepared by changing the water content in the oxidized fiber in the range of 4 to 9%, using a highest temperature at the graphitizing step in the range of 2,400 to 2,900°C, and at a draw ratio in the range of 0.95 to 1.12.
  • Figure 1 shows the relationships between the crystal size L c ( ⁇ ) and the elastic modulus E (GPa) in the graphite fibers obtained in Example 3.
  • the solid line is the boundary line of the formula (I) defined in the present invention and each numeral suffix indicates the run number in Example 3.
  • the oxidized fiber obtained in Example 1 was carbonized under a tension such that a shortening of the fiber length in a carbonizing furnace sealed with a nitrogen atmosphere did not occur.
  • the carbonizing furnace used had a temperature gradient such that the temperature was elevated from 400°C to 1,300°C.
  • the carbonized fiber was graphitized at a highest temperature of 2,250°C.
  • the specific gravity of the obtained graphite fiber was 1.81, the orientation degree of the carbon network determined by the X-ray diffractometry was 87.5%, and the crystal size (L c ) ) was 36 ⁇ .
  • the microvoid size calculated from the small-angle scattering was 15 ⁇ .
  • test pieces of a composite material were prepared by using the so-obtained graphite fiber and the composite was evaluated.
  • the tensile strength was 2.4 GPa
  • the flexural strength was 1.7 GPa
  • the compression strength was 1.4 GPa
  • precursors were prepared by the wet-spinning method by changing the substantial draft of the spun fiber by changing the spinneret orifice diameter in the range of from 0.05 to 0.075 mm in 6,000 orifices as a whole, and the coagulation and take-up speeds.
  • the substantial draft referred to herein means the ratio V i /V f of the take-up speed (V i ) under coagulation conditions to the free extrusion linear speed (V f ).
  • Other conditions were the same as those adopted in Example 1. Under some drafts, it was impossible to set the total draft ratio to 12.4. In this case, a highest draw ratio attainable was adopted.
  • L c 3 should be equal to or smaller than 6 x 104, that is, the crystal size (L c ) should be equal to or smaller than 39.1 ⁇ . It is seen that, if the denseness of the precursor fiber is low and the amount of iodine absorption is large, the elastic modulus is difficult to increase and the graphitizing temperature should be elevated, and the L c value is large and the microvoid size is large, with the result that the compression strength of the composite is low.
  • Graphite fibers having a different elastic modulus were obtained by using the precursor fiber obtained at run No. 16 of Example 5 and changing the water content of the oxidized fiber in the range of 4 to 9%, using a highest graphitizing temperature in the range of 2,000 to 2,850°C, and at a draw ratio in the range of 0.95 to 1.12.
  • Figure 2 shows the relationships between the crystal size L c ( ⁇ ) and the elastic modulus (GPa) in the graphite fibers obtained in Example 6.
  • the solid line is the boundary line of the formula (I) defined in the present invention, and each numeral suffix indicated the run number in Example 6.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Inorganic Fibers (AREA)

Claims (7)

  1. Graphitfaser mit einem Elastizitätsmodul E von 340 bis 680 GPa, wobei die Kristallgröße Lc (Å), die durch die Niveaubreite der Beugung zur Fläche (002) des Kohlenstoffgitters durch Röntgen-Weitwinkelstreuung bestimmt wurde, die durch die folgende Formel (I) bezüglich des Elastizitätsmoduls E (GPa) der Faser dargestellte Forderung erfüllt: L c   3 ≤ 0,918 x 10 3 E - 3 x 10 5 ,
    Figure imgb0014
     und der im Text der Beschreibung definierte Mikroporenradius, der durch Röntgen-Kleinwinkelstreuung bestimmt wurde, nicht mehr als 20 Å beträgt.
  2. Graphitfaser nach Anspruch 1, wobei das Elastizitätsmodul 440 bis 680 GPa beträgt.
  3. Verbundmaterial, das eine Graphitfaser wie in Anspruch 1 oder Anspruch 2 definiert enthält, wobei das Verbundmaterial eine Druckfestigkeit σc (GPa) aufweist, die die folgende Formel (II) bezüglich des Elastizitätsmoduls E (GPa) der Graphitfaser erfüllt: σc ≥ 1,715 - 1,5 x 10 -3 E.
    Figure imgb0015
  4. Verfahren zur Herstellung einer Graphitfaser, welches die Schritte umfaßt:
    Herstellen einer Faservorstufe mit einem Betrag der Iodadsorption von nicht mehr als 3 Gew.-% und einem durch das Röntgenverfahren bestimmten Orientierungsgrad von mindestens 85%, durch Spinnen einer Spinnlösung eines Acrylnitril-Copolymers, das 92 bis 99,95 Gew.-% Acrylnitril-Einheiten und 0,05 bis 8 Gew.-% copolymerisierte Monomereinheiten umfaßt;
    Oxidieren der Faservorstufe bei einer Temperatur von 200 bis 300°C in einer oxidierenden Atmosphäre, die mindestens 15 Vol.-% Sauerstoff enthält, wobei sie zumindest in der ersten Hälfte der Oxidation unter Spannung gehalten wird, wodurch eine oxidierte Faser mit einer Wasseradsorption von nicht mehr als 7 Gew.-% und einem durch das Röntgenverfahren bestimmten Orientierungsgrad von mindestens 78% erhalten wird;
    Carbonisieren der oxidierten Faser bei einer Temperatur von 400 bis 1500°C in einer inerten Atmosphäre unter Spannung, wodurch eine carbonisierte Faser erhalten wird; und anschließendes
    Graphitisieren der carbonisierten Faser bei einer Höchsttemperatur von 2200 bis 2800°C in einer inerten Atmosphäre unter Spannung.
  5. Verfahren nach Anspruch 4, wobei die Einzelfaser der Faservorstufe 1 oder weniger Denier aufweist.
  6. Verfahren nach Anspruch 4 oder Anspruch 5, wobei die Faservorstufe durch ein Trockendüsen-Naßspinnverfahren hergestellt wird.
  7. Verfahren nach einem der Ansprüche 4 bis 6, wobei die Faservorstufe bei einem wesentlichen Zug von 6 oder weniger und einem Ziehverhältnis von mindestens 10:1 hergestellt wird.
EP19880301424 1987-02-20 1988-02-19 Graphitfaser Expired - Lifetime EP0279687B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP35743/87 1987-02-20
JP3574387A JPS63211326A (ja) 1987-02-20 1987-02-20 高い圧縮強度を有する黒鉛繊維

Publications (3)

Publication Number Publication Date
EP0279687A2 EP0279687A2 (de) 1988-08-24
EP0279687A3 EP0279687A3 (de) 1991-04-03
EP0279687B1 true EP0279687B1 (de) 1996-02-14

Family

ID=12450302

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19880301424 Expired - Lifetime EP0279687B1 (de) 1987-02-20 1988-02-19 Graphitfaser

Country Status (3)

Country Link
EP (1) EP0279687B1 (de)
JP (1) JPS63211326A (de)
DE (1) DE3855003T2 (de)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2604866B2 (ja) * 1988-12-26 1997-04-30 東レ株式会社 アクリル系炭素繊維およびその製造方法
KR0156870B1 (ko) * 1989-09-05 1998-12-01 마에다 가쓰노스케 비원형단면 탄소섬유의 제조방법 및 이를 이용한 복합재료
JP2636509B2 (ja) * 1990-12-25 1997-07-30 東レ株式会社 炭素繊維およびその製造方法
JP3601581B2 (ja) * 1999-06-11 2004-12-15 東洋紡績株式会社 バナジウム系レドックスフロー電池用炭素電極材
PT1921183E (pt) 2005-08-09 2013-04-11 Toray Industries Fibra ignífuga, fibra de carbono e processos para produzir ambas
KR101335140B1 (ko) * 2005-12-13 2013-12-03 도레이 카부시키가이샤 탄소 섬유, 탄소 섬유 제조용 폴리아크릴로니트릴계 전구체섬유의 제조 방법, 및 탄소 섬유의 제조 방법
JP5072668B2 (ja) * 2008-03-14 2012-11-14 東邦テナックス株式会社 前駆体繊維、並びに、前駆体繊維、耐炎化繊維及び炭素繊維の製造方法
JP5537617B2 (ja) * 2012-07-24 2014-07-02 東邦テナックス株式会社 前駆体繊維、並びに、前駆体繊維、耐炎化繊維及び炭素繊維の製造方法

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1110791A (en) * 1964-04-24 1968-04-24 Nat Res Dev The production of carbon fibres
GB1093084A (en) * 1965-03-16 1967-11-29 Union Carbide Corp Manufactured graphite yarn
JPS597803B2 (ja) * 1978-02-16 1984-02-21 東邦ベスロン株式会社 高強度高弾性黒鉛繊維の製造法
JPS575922A (en) * 1980-06-09 1982-01-12 Mitsubishi Rayon Co Ltd Preparation of graphite fiber
JPS57121623A (en) * 1981-01-20 1982-07-29 Mitsubishi Rayon Co Ltd Preparation of graphite fiber
JPS58214534A (ja) * 1982-06-09 1983-12-13 Toray Ind Inc 高強伸度炭素繊維束およびその製法
EP0159365B1 (de) * 1983-10-13 1991-09-04 Mitsubishi Rayon Co., Ltd. Kohlenstoffasern mit hoher festigkeit und hohem elastizitätsmodul sowie deren herstellungsverfahren

Also Published As

Publication number Publication date
EP0279687A2 (de) 1988-08-24
JPS63211326A (ja) 1988-09-02
DE3855003T2 (de) 1996-06-27
EP0279687A3 (de) 1991-04-03
DE3855003D1 (de) 1996-03-28

Similar Documents

Publication Publication Date Title
EP1130140B1 (de) Vorlaüferfaser aus acrylonitril für kohlenstofffaser und herstellungsverfahren
KR950008909B1 (ko) 고강도, 초고탄성률 탄소섬유
US5269984A (en) Process of making graphite fiber
US5168004A (en) Melt-spun acrylic fibers possessing a highly uniform internal structure which are particularly suited for thermal conversion to quality carbon fibers
EP0223199B1 (de) Verfahren zur Herstellung von Kohlenstoffasern mit hoher Festigkeit und hohem Elastizitätsmodul
CA1317422C (en) Formation of melt-spun acrylic fibers possessing a highly uniform internal structure which are particularly suited for thermal conversion to quality carbon fibers
EP0279687B1 (de) Graphitfaser
US4637925A (en) Ultrahigh strength carbon fibers
US3556729A (en) Process for oxidizing and carbonizing acrylic fibers
US3925524A (en) Process for the production of carbon filaments
JP2002266173A (ja) 炭素繊維および炭素繊維強化複合材料
US4975263A (en) Process for producing mesophase pitch-based carbon fibers
Ashitaka et al. Preparation of carbon fibers from syndiotactic 1, 2‐polybutadiene
US5114697A (en) High strength, high modulus pitch-based carbon fiber
JP3890770B2 (ja) 炭素繊維束、およびその製造方法
CA2007067A1 (en) Composite metal-loaded carbon fibers
JP7447788B2 (ja) 炭素繊維束およびその製造方法
US5348719A (en) Process for producing carbon fibers having high strand strength
JPH01124629A (ja) 高い圧縮強度を有する黒鉛繊維
JPS6141326A (ja) 炭素繊維製造用プレカ−サ−の製造方法
JP4238436B2 (ja) 炭素繊維の製造方法
JP2707845B2 (ja) アクリロニトリル系黒鉛化繊維の製造方法
KR102197333B1 (ko) 폴리아크릴로니트릴계 내염화 섬유, 탄소섬유 및 그의 제조방법
JP3303424B2 (ja) アクリル系炭素繊維の製造方法
JPH02264011A (ja) 黒鉛繊維製造用アクリル系繊維

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): DE FR GB IT

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

17P Request for examination filed

Effective date: 19901224

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): DE FR GB IT

17Q First examination report despatched

Effective date: 19930816

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB IT

REF Corresponds to:

Ref document number: 3855003

Country of ref document: DE

Date of ref document: 19960328

ITF It: translation for a ep patent filed

Owner name: UFFICIO BREVETTI RICCARDI & C.

ET Fr: translation filed
PLBI Opposition filed

Free format text: ORIGINAL CODE: 0009260

PLBF Reply of patent proprietor to notice(s) of opposition

Free format text: ORIGINAL CODE: EPIDOS OBSO

26 Opposition filed

Opponent name: AKZO NOBEL FASER AG

Effective date: 19961106

PLBF Reply of patent proprietor to notice(s) of opposition

Free format text: ORIGINAL CODE: EPIDOS OBSO

PLBF Reply of patent proprietor to notice(s) of opposition

Free format text: ORIGINAL CODE: EPIDOS OBSO

PLBL Opposition procedure terminated

Free format text: ORIGINAL CODE: EPIDOS OPPC

PLBM Termination of opposition procedure: date of legal effect published

Free format text: ORIGINAL CODE: 0009276

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: OPPOSITION PROCEDURE CLOSED

27C Opposition proceedings terminated

Effective date: 19990524

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20070214

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20070215

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20070625

Year of fee payment: 20

REG Reference to a national code

Ref country code: GB

Ref legal event code: PE20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20070208

Year of fee payment: 20

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20080218