JP2010100970A - Method for producing carbon fiber - Google Patents
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- JP2010100970A JP2010100970A JP2008274117A JP2008274117A JP2010100970A JP 2010100970 A JP2010100970 A JP 2010100970A JP 2008274117 A JP2008274117 A JP 2008274117A JP 2008274117 A JP2008274117 A JP 2008274117A JP 2010100970 A JP2010100970 A JP 2010100970A
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- polyacrylonitrile
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- 229920000049 Carbon (fiber) Polymers 0.000 title claims abstract description 47
- 239000004917 carbon fiber Substances 0.000 title claims abstract description 47
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 title claims abstract description 42
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 17
- 239000000835 fiber Substances 0.000 claims abstract description 101
- 229920002239 polyacrylonitrile Polymers 0.000 claims abstract description 82
- 238000003763 carbonization Methods 0.000 claims abstract description 53
- 238000009987 spinning Methods 0.000 claims abstract description 48
- 229920000642 polymer Polymers 0.000 claims abstract description 25
- 238000009656 pre-carbonization Methods 0.000 claims abstract description 13
- 239000012298 atmosphere Substances 0.000 claims abstract description 10
- 238000000034 method Methods 0.000 claims description 103
- 230000008569 process Effects 0.000 claims description 55
- 238000005345 coagulation Methods 0.000 claims description 31
- 230000015271 coagulation Effects 0.000 claims description 31
- 238000007380 fibre production Methods 0.000 claims description 6
- 230000001112 coagulating effect Effects 0.000 abstract description 2
- RNFJDJUURJAICM-UHFFFAOYSA-N 2,2,4,4,6,6-hexaphenoxy-1,3,5-triaza-2$l^{5},4$l^{5},6$l^{5}-triphosphacyclohexa-1,3,5-triene Chemical compound N=1P(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP=1(OC=1C=CC=CC=1)OC1=CC=CC=C1 RNFJDJUURJAICM-UHFFFAOYSA-N 0.000 abstract 1
- 239000003063 flame retardant Substances 0.000 abstract 1
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 description 33
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 27
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 26
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 24
- 239000000243 solution Substances 0.000 description 22
- 230000005484 gravity Effects 0.000 description 16
- 239000002904 solvent Substances 0.000 description 16
- 238000010438 heat treatment Methods 0.000 description 15
- 239000011550 stock solution Substances 0.000 description 15
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 description 14
- 238000002166 wet spinning Methods 0.000 description 11
- 239000002243 precursor Substances 0.000 description 10
- 238000000578 dry spinning Methods 0.000 description 9
- OZAIFHULBGXAKX-UHFFFAOYSA-N 2-(2-cyanopropan-2-yldiazenyl)-2-methylpropanenitrile Chemical compound N#CC(C)(C)N=NC(C)(C)C#N OZAIFHULBGXAKX-UHFFFAOYSA-N 0.000 description 8
- 150000002894 organic compounds Chemical class 0.000 description 8
- 239000007788 liquid Substances 0.000 description 7
- 238000003756 stirring Methods 0.000 description 7
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 description 6
- 239000003795 chemical substances by application Substances 0.000 description 6
- 230000006872 improvement Effects 0.000 description 6
- 238000006116 polymerization reaction Methods 0.000 description 6
- 230000001737 promoting effect Effects 0.000 description 6
- VGTPCRGMBIAPIM-UHFFFAOYSA-M sodium thiocyanate Chemical compound [Na+].[S-]C#N VGTPCRGMBIAPIM-UHFFFAOYSA-M 0.000 description 6
- JAHNSTQSQJOJLO-UHFFFAOYSA-N 2-(3-fluorophenyl)-1h-imidazole Chemical compound FC1=CC=CC(C=2NC=CN=2)=C1 JAHNSTQSQJOJLO-UHFFFAOYSA-N 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 5
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 5
- FXHOOIRPVKKKFG-UHFFFAOYSA-N N,N-Dimethylacetamide Chemical compound CN(C)C(C)=O FXHOOIRPVKKKFG-UHFFFAOYSA-N 0.000 description 5
- 238000001035 drying Methods 0.000 description 5
- 239000007789 gas Substances 0.000 description 5
- LVHBHZANLOWSRM-UHFFFAOYSA-N methylenebutanedioic acid Natural products OC(=O)CC(=C)C(O)=O LVHBHZANLOWSRM-UHFFFAOYSA-N 0.000 description 5
- 238000004804 winding Methods 0.000 description 5
- RFFLAFLAYFXFSW-UHFFFAOYSA-N 1,2-dichlorobenzene Chemical compound ClC1=CC=CC=C1Cl RFFLAFLAYFXFSW-UHFFFAOYSA-N 0.000 description 4
- 239000000701 coagulant Substances 0.000 description 4
- 229920001577 copolymer Polymers 0.000 description 4
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- 229920005989 resin Polymers 0.000 description 4
- 239000011347 resin Substances 0.000 description 4
- 238000005406 washing Methods 0.000 description 4
- JIAARYAFYJHUJI-UHFFFAOYSA-L zinc dichloride Chemical compound [Cl-].[Cl-].[Zn+2] JIAARYAFYJHUJI-UHFFFAOYSA-L 0.000 description 4
- 239000004372 Polyvinyl alcohol Substances 0.000 description 3
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- DNIAPMSPPWPWGF-UHFFFAOYSA-N Propylene glycol Chemical compound CC(O)CO DNIAPMSPPWPWGF-UHFFFAOYSA-N 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 238000004140 cleaning Methods 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 239000002131 composite material Substances 0.000 description 3
- 238000007334 copolymerization reaction Methods 0.000 description 3
- 238000007654 immersion Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 238000000465 moulding Methods 0.000 description 3
- 229920002451 polyvinyl alcohol Polymers 0.000 description 3
- 150000003839 salts Chemical class 0.000 description 3
- 238000004513 sizing Methods 0.000 description 3
- 239000003381 stabilizer Substances 0.000 description 3
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 description 2
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 2
- 229920002972 Acrylic fiber Polymers 0.000 description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 description 2
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 239000001099 ammonium carbonate Substances 0.000 description 2
- WERYXYBDKMZEQL-UHFFFAOYSA-N butane-1,4-diol Chemical compound OCCCCO WERYXYBDKMZEQL-UHFFFAOYSA-N 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000010528 free radical solution polymerization reaction Methods 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 239000003960 organic solvent Substances 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- 230000000379 polymerizing effect Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000010558 suspension polymerization method Methods 0.000 description 2
- 239000011592 zinc chloride Substances 0.000 description 2
- 235000005074 zinc chloride Nutrition 0.000 description 2
- XEEYSDHEOQHCDA-UHFFFAOYSA-N 2-methylprop-2-ene-1-sulfonic acid Chemical compound CC(=C)CS(O)(=O)=O XEEYSDHEOQHCDA-UHFFFAOYSA-N 0.000 description 1
- OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 description 1
- 229910000013 Ammonium bicarbonate Inorganic materials 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 239000002202 Polyethylene glycol Substances 0.000 description 1
- 239000003929 acidic solution Substances 0.000 description 1
- 125000005396 acrylic acid ester group Chemical group 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 235000012538 ammonium bicarbonate Nutrition 0.000 description 1
- 235000012501 ammonium carbonate Nutrition 0.000 description 1
- 150000003863 ammonium salts Chemical class 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000010000 carbonizing Methods 0.000 description 1
- 239000012986 chain transfer agent Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 238000000280 densification Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 230000008034 disappearance Effects 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 239000008151 electrolyte solution Substances 0.000 description 1
- 238000010556 emulsion polymerization method Methods 0.000 description 1
- 238000009730 filament winding Methods 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 235000019253 formic acid Nutrition 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 238000001891 gel spinning Methods 0.000 description 1
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 description 1
- 239000003999 initiator Substances 0.000 description 1
- 150000002484 inorganic compounds Chemical class 0.000 description 1
- 229910010272 inorganic material Inorganic materials 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 125000005397 methacrylic acid ester group Chemical group 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 239000000178 monomer Substances 0.000 description 1
- 230000003472 neutralizing effect Effects 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 229920001223 polyethylene glycol Polymers 0.000 description 1
- 229920001451 polypropylene glycol Polymers 0.000 description 1
- -1 polytetramethylene Polymers 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 230000002250 progressing effect Effects 0.000 description 1
- UIIIBRHUICCMAI-UHFFFAOYSA-N prop-2-ene-1-sulfonic acid Chemical compound OS(=O)(=O)CC=C UIIIBRHUICCMAI-UHFFFAOYSA-N 0.000 description 1
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000002787 reinforcement Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 235000002639 sodium chloride Nutrition 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 230000008961 swelling Effects 0.000 description 1
- 229940073455 tetraethylammonium hydroxide Drugs 0.000 description 1
- LRGJRHZIDJQFCL-UHFFFAOYSA-M tetraethylazanium;hydroxide Chemical compound [OH-].CC[N+](CC)(CC)CC LRGJRHZIDJQFCL-UHFFFAOYSA-M 0.000 description 1
- 238000001721 transfer moulding Methods 0.000 description 1
- 239000002759 woven fabric Substances 0.000 description 1
- 229910052724 xenon Inorganic materials 0.000 description 1
- FHNFHKCVQCLJFQ-UHFFFAOYSA-N xenon atom Chemical compound [Xe] FHNFHKCVQCLJFQ-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Artificial Filaments (AREA)
- Inorganic Fibers (AREA)
Abstract
Description
本発明は、高分子量のポリアクリルニトリル系重合度からなり、延伸倍率が高いポリアクリロニトリル系繊維を焼成する、生産性の高い炭素繊維の製造方法に関するものである。 The present invention relates to a highly productive carbon fiber production method for firing polyacrylonitrile fibers having a high molecular weight polyacrylonitrile polymerization degree and a high draw ratio.
炭素繊維は、その優れた力学的、化学的諸特性及び軽量性などによりさまざまな用途に利用されている。近年では、従来のゴルフクラブや釣竿などのスポーツ用途、航空機用途に加え、自動車部材、ＣＮＧタンク、建造物の耐震補強、船舶部材などいわゆる一般産業用途への展開が進んでいる。このように適用範囲が広がる反面、炭素繊維については生産性の向上への要求が求められている。 Carbon fibers are used in various applications due to their excellent mechanical and chemical properties and light weight. In recent years, in addition to conventional golf clubs, fishing rods and other sports applications and aircraft applications, the development of so-called general industrial applications such as automobile members, CNG tanks, seismic reinforcement of buildings, and ship members has been progressing. As described above, the range of application is widened, but there is a demand for improving the productivity of carbon fibers.
炭素繊維の生産性を向上させる手段として、前駆体であるポリアクリロニトリル系繊維の製造工程、耐炎化、炭化工程において、毛羽や糸切れを抑制し、工程通過性を向上させることが挙げられる。 As a means for improving the productivity of carbon fiber, it is possible to suppress fluff and yarn breakage and improve process passability in the production process, flame resistance and carbonization process of polyacrylonitrile fiber as a precursor.
また、炭素繊維の生産性を向上させる別の手段として、前駆体であるポリアクリロニトリル系繊維を製造する際に、口金から吐出する紡糸原液量を増加させ、高速化により太糸条化および高密度化することなく工程の速度を高める方法が提案されている。 As another means to improve the productivity of carbon fiber, when producing polyacrylonitrile fiber, which is a precursor, the amount of spinning solution discharged from the die is increased, and the yarn speed and density are increased by increasing the speed. There has been proposed a method for increasing the speed of the process without making it.
高速化としては、まず凝固浴からアクリル系繊維を引き取る速度を高める方法があるが、可紡性の限界を超えての操業はできないため、速度を大きく高めることは困難である。 As for speeding up, there is a method of increasing the speed at which the acrylic fiber is taken out from the coagulation bath, but it is difficult to increase the speed greatly because the operation beyond the spinnability limit cannot be performed.
そこで、凝固浴から吐出糸条を引き取る速度は変えずに、浴中延伸あるいは加圧スチーム延伸により徐々に速度を高め、最終の巻き取り速度を高める方法が主に採用されており、その延伸工程を改良することによりさらに延伸性を高め、製造コストを低減する方法が提案されている。 Therefore, the method of gradually increasing the final winding speed by gradually increasing the speed by stretching in the bath or pressurized steam stretching without changing the speed at which the discharged yarn is pulled from the coagulation bath is mainly adopted. There has been proposed a method of further improving the stretchability by improving the thickness and reducing the production cost.
その一つとして、口金吐出条件を制御したポリアクリロニトリル系繊維及び炭素繊維の生産性向上が提案されている。ポリアクリロニトリル系重合体の極限粘度として、従来より採用されている極限粘度と同等以上の１．５〜５の範囲を採用し、加圧スチーム延伸を実施することで全延伸倍率１６．５倍までの延伸を可能としている（特許文献１実施例参照）。 As one of them, an improvement in productivity of polyacrylonitrile fiber and carbon fiber with controlled die discharge conditions has been proposed. As the intrinsic viscosity of the polyacrylonitrile-based polymer, a range of 1.5 to 5 that is equal to or higher than the intrinsic viscosity that has been conventionally adopted is adopted, and the total draw ratio is up to 16.5 times by performing the pressure steam stretching. Can be stretched (see Examples in Patent Document 1).
上記該特許文献１と同様に高分子量ポリアクリロニトリルを用いた炭素繊維の製造方法として、分子量５０万以上のポリアクリロニトリルを使用した例が知られている（特許文献２参照）。この特許文献２の実施例等で用いられているポリマーは７２万程度で、延伸倍率が１０倍以上では耐炎化、炭化工程での伸長操作を施すことが不可能になるとの記載があり、該特許文献２中には高倍率延伸による生産性向上に関する記載はない。 As in the case of the above-mentioned Patent Document 1, an example of using a polyacrylonitrile having a molecular weight of 500,000 or more is known as a method for producing a carbon fiber using a high molecular weight polyacrylonitrile (see Patent Document 2). There is a description that the polymer used in the examples of Patent Document 2 is about 720,000, and that it is impossible to perform an elongation operation in the carbonization process when the stretch ratio is 10 times or more. In Patent Document 2, there is no description about productivity improvement by high-magnification drawing.
また、高重合度ポリアクリロニトリル系重合体を用いた例が提案されている。極限粘度２．５〜３．３を用いた場合には、延伸倍率が１０〜２０倍である（特許文献３参照）。分子量１００万以上のポリアクリロニトリル系重合体を用いた例では実施例で用いられているポリアクリロニトリル系重合体の分子量は最大で１３４万であり、延伸倍率の最大が２９．７倍である（特許文献４参照）。いずれも、タイヤコードなどに用いられる高強力アクリル繊維を得るための高強度化技術であり、炭素繊維に関する記載はない。 In addition, an example using a polyacrylonitrile polymer having a high polymerization degree has been proposed. When limiting viscosity 2.5-3.3 is used, a draw ratio is 10-20 times (refer to patent documents 3). In the case of using a polyacrylonitrile polymer having a molecular weight of 1 million or more, the polyacrylonitrile polymer used in the examples has a maximum molecular weight of 1.34 million and the maximum draw ratio is 29.7 times (patent) Reference 4). Both are high-strength technologies for obtaining high-strength acrylic fibers used for tire cords and the like, and there is no description regarding carbon fibers.
上述の高重合度ポリアクリロニトリル系重合体より、高い分子量のポリマーを繊維化した例が知られている。１ｗｔ％の低濃度溶液から、紡糸した糸を高倍率で延伸することで、高配向のポリアクリロニトリル系繊維を得る技術である（非特許文献１参照）。この非特許文献１には炭素繊維に関する記載がなく、溶液濃度が１ｗｔ％と低いため生産性の向上は難しい。 An example in which a polymer having a higher molecular weight is made into a fiber than the above-described high-polymerization degree polyacrylonitrile-based polymer is known. In this technique, a highly oriented polyacrylonitrile fiber is obtained by stretching a spun yarn at a high magnification from a low concentration solution of 1 wt% (see Non-Patent Document 1). This non-patent document 1 does not describe the carbon fiber, and it is difficult to improve productivity because the solution concentration is as low as 1 wt%.
したがって、高分子量ポリアクリロニトリルを用いた、超延伸により炭素繊維の生産性の向上を目的とした例は知られていないのが現状である。
本発明の課題は、かかる現状に鑑み、炭素繊維を製造するにあたり生産性の向上に寄与する炭素繊維の製造方法を提供することにある。 The subject of this invention is providing the manufacturing method of the carbon fiber which contributes to the improvement of productivity in manufacturing carbon fiber in view of this present condition.
本発明は、上記課題を解決するために、次の構成を有するものである。
（１）極限粘度が６以上であるポリアクリロニトリル系重合体からなる紡糸原液を口金から吐出し、凝固浴にて凝固し、全延伸倍率が２０〜１２０の範囲で延伸を行ったポリアクリロニトリル系繊維を空気中で２００〜３００℃の温度範囲で耐炎化した後、３００〜８００℃の温度の不活性雰囲気中において予備炭化処理し、引き続き不活性雰囲気中で８００〜２０００℃の範囲の温度で炭化処理することを特徴とする炭素繊維の製造方法。
（２）紡糸原液中のポリアクリロニトリル系重合体濃度が１．５〜１５重量％であることを特徴とする前記（１）記載の炭素繊維の製造方法。
（３）耐炎化処理での張力が、０．２〜１．０ｃＮ／ｄｔｅｘであることを特徴とする前記（１）または（２）記載の炭素繊維の製造方法。
（４）炭化処理での張力が、０．５〜３．０ｃＮ／ｄｔｅｘであることを特徴とする前記（１）〜（３）のいずれか一項記載の炭素繊維の製造方法。
In order to solve the above problems, the present invention has the following configuration.
(1) A polyacrylonitrile fiber obtained by discharging a spinning stock solution composed of a polyacrylonitrile polymer having an intrinsic viscosity of 6 or more from a die, coagulating in a coagulation bath, and stretching the total draw ratio in the range of 20 to 120. After flameproofing in air at a temperature range of 200 to 300 ° C., pre-carbonizing in an inert atmosphere at a temperature of 300 to 800 ° C., followed by carbonization at a temperature in the range of 800 to 2000 ° C. in an inert atmosphere. A method for producing a carbon fiber, which comprises treating the carbon fiber.
(2) The method for producing carbon fiber as described in (1) above, wherein the concentration of the polyacrylonitrile polymer in the spinning dope is 1.5 to 15% by weight.
(3) The method for producing carbon fiber according to (1) or (2) above, wherein the tension in the flameproofing treatment is 0.2 to 1.0 cN / dtex.
(4) The carbon fiber production method according to any one of (1) to (3), wherein a tension in carbonization is 0.5 to 3.0 cN / dtex.
本発明によれば、従来より採用されている炭素繊維製造の設備条件、収率などのプロセス性を損なうことなく、炭素繊維前駆体であるポリアクリロニトリル系繊維の最終巻き取り速度を向上し、耐炎化、炭化処理においても高張力延伸処理で安定して工程を通過することができ、高い生産性で炭素繊維を得ることができる。 According to the present invention, the final winding speed of the polyacrylonitrile-based fiber that is the carbon fiber precursor is improved without impairing the processability such as the equipment conditions and yield of carbon fiber production that have been conventionally employed, and flame resistance Also in the carbonization and carbonization treatment, the process can be stably passed by the high tension drawing treatment, and the carbon fiber can be obtained with high productivity.
以下、本発明の炭素繊維の製造方法について詳細に説明する。 Hereinafter, the manufacturing method of the carbon fiber of this invention is demonstrated in detail.
本発明におけるポリアクリロニトリル系繊維用ポリアクリロニトリル系重合体の極限粘度は、６以上の範囲とする。６以上にすることで、ポリアクリロニトリル系繊維を高倍率延伸が可能となり、最終巻き取り速度が上がるため生産性が向上する。また、ポリアクリロニトリル系繊維を高倍率で延伸ができることで高配向化するため、その後の耐炎化・炭化工程においても高い張力で延伸しても糸切れを抑制でき、工程通過性が上がることから生産性が向上できるため好ましい。 The intrinsic viscosity of the polyacrylonitrile polymer for polyacrylonitrile fiber in the present invention is in the range of 6 or more. By making it 6 or more, the polyacrylonitrile fiber can be stretched at a high magnification, and the final winding speed is increased, so that productivity is improved. In addition, since polyacrylonitrile fiber can be stretched at a high magnification to achieve high orientation, yarn breakage can be suppressed even when stretched with high tension in the subsequent flameproofing and carbonization processes, and the processability is improved. It is preferable because the property can be improved.
極限粘度は８以上が好ましく、９以上がより好ましい。また、極限粘度はポリアクリロニトリル系重合体の安定した重合の点から、１２以下であることが好ましい。極限粘度は、重合時のモノマー濃度、開始剤や連鎖移動剤の量などにより制御することができる。 The intrinsic viscosity is preferably 8 or more, more preferably 9 or more. The intrinsic viscosity is preferably 12 or less from the viewpoint of stable polymerization of the polyacrylonitrile polymer. The intrinsic viscosity can be controlled by the monomer concentration during polymerization, the amount of initiator and chain transfer agent, and the like.
本発明において、極限粘度とはジメチルホルムアミドを溶媒とし、オストワルド粘度計を用い、ポリマーを２５℃の状態に保持して測定した比粘度をもとに算出した極限粘度のことをいう。具体的には、以下のような手順で測定する。
予め１２０℃で２時間熱処理し絶乾したポリアクリロニトリル系繊維用重合体１５０ｍｇを、２５℃に保持して５０ｍｌのチオシアン酸ナトリウム０．１ｍｏｌ／リットル添加Ｎ，Ｎ−ジメチルホルムアミド（いずれも和光純薬社製特級）に溶解させる。得られた溶液を、２５℃の温水槽中で温調し、予め２５℃に温調してあるオストワルド粘度計を用いて標線間の落下時間を１／１００秒の精度で測定し、その時間をｔ（秒）とする。同様に、炭素繊維前駆体繊維用ポリアクリロニトリル系繊維用重合体を溶解していないチオシアン酸ナトリウム０．１ｍｏｌ／リットル添加ジメチルホルムアミドについても測定し、その落下時間をｔ０（秒）とする。次式を用いて極限粘度［η］を算出する。
［η］＝｛（１＋１．３２×ηｓｐ）１／２―１｝／０．１９８
ηｓｐ＝（ｔ／ｔ０）−１
本発明において、ポリアクリロニトリル系繊維に用いられるポリアクリロニトリル系重合体は、アクリロニトリル１００％を重合してなっていても良いが、耐炎化効率化の観点および製糸性の観点から共重合体が好ましく用いられる。他の共重合成分としては、いわゆる耐炎化促進成分として、アクリル酸、メタクリル酸およびイタコン酸等が好ましく挙げられ、より好ましくは、これらの一部または全量をアンモニアで中和したアクリル酸、メタクリル酸およびイタコン酸のアンモニウム塩からなる共重合体が挙げられる。また、製糸性向上の観点からは、メタクリル酸エステル、アクリル酸エステル、アリルスルホン酸金属塩およびメタリルスルホン酸金属塩などが好ましく共重合できる。
In the present invention, the intrinsic viscosity refers to an intrinsic viscosity calculated based on a specific viscosity measured using an Ostwald viscometer using dimethylformamide as a solvent and keeping the polymer at 25 ° C. Specifically, the measurement is performed according to the following procedure.
150 mg of a polyacrylonitrile fiber polymer that had been heat-treated at 120 ° C. for 2 hours and dried completely was maintained at 25 ° C., and 50 ml of sodium thiocyanate 0.1 mol / liter added N, N-dimethylformamide (both Wako Pure Chemical Industries) Dissolve in special grade) The obtained solution was temperature-controlled in a hot water bath at 25 ° C., and the drop time between the marked lines was measured with an accuracy of 1/100 second using an Ostwald viscometer that was previously temperature-controlled at 25 ° C. Let time be t (seconds). Similarly, 0.1 mol / liter-added dimethylformamide with sodium thiocyanate in which the polyacrylonitrile fiber polymer for carbon fiber precursor fibers is not dissolved is also measured, and the drop time is defined as t0 (seconds). The intrinsic viscosity [η] is calculated using the following formula.
[Η] = {(1 + 1.32 × ηsp) 1/2 −1} /0.198
ηsp = (t / t0) −1
In the present invention, the polyacrylonitrile-based polymer used for the polyacrylonitrile-based fiber may be obtained by polymerizing 100% acrylonitrile, but a copolymer is preferably used from the viewpoint of improving flame resistance efficiency and from the standpoint of yarn production. It is done. As other copolymerization components, acrylic acid, methacrylic acid, itaconic acid and the like are preferably mentioned as so-called flame resistance promoting components, and more preferably, acrylic acid or methacrylic acid obtained by neutralizing part or all of these with ammonia. And a copolymer comprising an ammonium salt of itaconic acid. Further, from the viewpoint of improving the yarn-making property, methacrylic acid ester, acrylic acid ester, allyl sulfonic acid metal salt, methallyl sulfonic acid metal salt and the like can be preferably copolymerized.
上述した共重合体中の共重合成分の量は、合計で０〜１０モル％が好ましく、より好ましくは０．１〜６モル％であり、さらに好ましくは０．２〜２モル％である。共重合成分の量が少なすぎると製糸性が低下し、共重合体の量が多いと耐熱性が低下し、続く耐炎化工程で糸同士の融着が発生しやすくなるため、両者のバランスを考慮して設定することがよい。 As for the quantity of the copolymerization component in the copolymer mentioned above, 0-10 mol% is preferable in total, More preferably, it is 0.1-6 mol%, More preferably, it is 0.2-2 mol%. If the amount of the copolymerization component is too small, the yarn-forming property is lowered, and if the amount of the copolymer is large, the heat resistance is lowered, and the fusion between the yarns easily occurs in the subsequent flameproofing process. It is better to set in consideration.
かかるポリアクリロニトリル系重合体を重合する方法としては、公知の方法が採用でき、溶液重合法、懸濁重合法および乳化重合法等を適用することができる。その中でも懸濁重合法が、重合時に発生する反応熱を効果的に除熱することができるため、生産性が向上し好ましい。 As a method for polymerizing such a polyacrylonitrile-based polymer, a known method can be adopted, and a solution polymerization method, a suspension polymerization method, an emulsion polymerization method, and the like can be applied. Among them, the suspension polymerization method is preferable because it can effectively remove the heat of reaction generated during the polymerization, thereby improving productivity.
ポリアクリロニトリル系重合体を紡糸することで炭素繊維前駆体であるポリアクリロニトリル系繊維が得られる。紡糸に際し、有機あるいは無機の該ポリアクリロニトリル系重合体が可溶な従来公知の溶媒に溶解し、紡糸原液とする。有機溶媒を使用することが好ましく、具体的には、溶媒として、ジメチルホルムアミド、ジメチルアセトアミドおよびジメチルスルホキシド、塩化亜鉛水溶液、チオシアン酸ナトリウム水溶液等が使用される。 A polyacrylonitrile fiber, which is a carbon fiber precursor, is obtained by spinning a polyacrylonitrile polymer. At the time of spinning, the organic or inorganic polyacrylonitrile-based polymer is dissolved in a conventionally known solvent to form a spinning dope. An organic solvent is preferably used. Specifically, dimethylformamide, dimethylacetamide and dimethylsulfoxide, an aqueous zinc chloride solution, an aqueous sodium thiocyanate, or the like is used as the solvent.
本発明において用いられる紡糸原液は、種々の方法、例えば、固体ポリアクリロニトリルを溶媒中に懸濁させ、ついで高温にて攪拌するか、または該懸濁液を混合及び搬送部を備えた２軸スクリュー押出機を用いることにより製造できる。 The spinning dope used in the present invention can be prepared by various methods, for example, by suspending solid polyacrylonitrile in a solvent and then stirring at a high temperature, or by mixing the suspension with a twin screw It can be manufactured by using an extruder.
本発明においては、ポリアクリロニトリル系前駆体繊維を、ポリアクリロニトリル系重合体が１．５〜１５重量％の濃度で溶媒に溶解した紡糸原液を繊維化させて得ることが好ましい。紡糸原液におけるポリアクリロニトリル系重合体の濃度が１．５重量％以上になると、凝固工程において重合体の凝集が進み、製糸速度を上げることができるため好ましい。１５重量％以下にすることで、ポリアクリロニトリル系繊維を製造する際の延伸工程において高倍率延伸が可能となり生産性が向上する。また。高倍率延伸をした時にも糸切れが発生しにくくなることに加えて、その後の耐炎化工程および炭化工程においても耐炎化張力および炭化張力を高く保っても糸切れが発生しにくくなることから、生産性が向上し好ましい。紡糸原液中のポリアクリロニトリル系重合体濃度は、２重量％以上１０重量％以下、２重量％以上７重量％以下、あるいは２．５重量％以上１０重量％以下、さらには２．５重量％以上７重量％以下であることがより好ましい。 In the present invention, it is preferable that the polyacrylonitrile-based precursor fiber is obtained by fiberizing a spinning stock solution in which a polyacrylonitrile-based polymer is dissolved in a solvent at a concentration of 1.5 to 15% by weight. It is preferable that the concentration of the polyacrylonitrile polymer in the spinning dope is 1.5% by weight or more because the aggregation of the polymer proceeds in the coagulation step and the spinning speed can be increased. By making it 15% by weight or less, high-magnification stretching is possible in the stretching step when producing polyacrylonitrile fiber, and productivity is improved. Also. In addition to the fact that yarn breakage is less likely to occur when stretched at a high magnification, yarn breakage is less likely to occur even if the flameproofing tension and carbonization tension are kept high in the subsequent flameproofing step and carbonization step. Productivity is improved, which is preferable. The concentration of the polyacrylonitrile polymer in the spinning dope is 2% by weight to 10% by weight, 2% by weight to 7% by weight, or 2.5% by weight to 10% by weight, and further 2.5% by weight or more. More preferably, it is 7% by weight or less.
かかる紡糸原液を紡糸する前に、紡糸原液を目開き１０μｍ以下のフィルターに通し、ポリマー原料および各工程において混入した不純物を除去することが好ましい。これにより、製造工程において、不純物に起因した糸切れが現象し、生産性が向上する。目開きとは、フィルターの網の目の寸法を表す。網目の形状が長方形の場合には、両方が１０μｍ以下であることが好ましい。目開きは１μｍ以下であることがより好ましい。また、目開きは紡糸原液がフィルターを通過する速度が速くなることから、０．０５μｍ以上であることがより好ましい。 Before spinning the spinning dope, it is preferable to pass the spinning dope through a filter having an opening of 10 μm or less to remove the polymer raw material and impurities mixed in each step. As a result, yarn breakage due to impurities occurs in the manufacturing process, and productivity is improved. Opening means the size of the mesh of the filter. When the mesh shape is rectangular, both are preferably 10 μm or less. The mesh opening is more preferably 1 μm or less. Further, the mesh opening is more preferably 0.05 μm or more because the speed at which the spinning dope passes through the filter increases.
紡糸方法としては、湿式紡糸法や乾湿式紡糸法が、その高い生産性から好適に用いられる。湿式紡糸とは紡糸口金を凝固浴中に浸漬して糸条を吐出する方法、乾湿式紡糸とは紡糸口金から吐出した糸条を一旦空気などの気体中を経由させて凝固浴中に導入する紡糸方法を言う。中でも、乾湿式紡糸法が、繊維の緻密性を高めることができ、本発明においてはより好適に用いることができる。 As the spinning method, a wet spinning method or a dry-wet spinning method is preferably used because of its high productivity. Wet spinning is a method in which the spinneret is immersed in a coagulation bath and the yarn is discharged, and dry and wet spinning is a method in which the yarn discharged from the spinneret is once introduced into the coagulation bath via a gas such as air. Say the spinning method. Among these, the dry and wet spinning method can increase the denseness of the fiber and can be used more suitably in the present invention.
本発明で用いられる口金吐出孔の形状は、孔径Ｄが０．０５〜５．０ｍｍの範囲であることが好ましい。０．０５ｍｍより大きいことで、製糸性が向上し、５．０ｍｍより小さいことで、糸切れが少なくなる。より好ましくは孔径Ｄが０．０８〜１．０ｍｍの範囲であり、０．２〜０．８ｍｍである。孔深度Ｌが０．１〜５ｍｍの範囲であり、孔深度Ｌが０．１６〜３ｍｍの範囲であることがより好ましい。孔深度Ｌが０．１ｍｍ以上であることで製糸性が向上し、５ｍｍ以下であることで、吐出時の圧力が減少するため好ましい。Ｌ／Ｄが１．５〜４の範囲であることが好ましい。Ｌ／Ｄが２〜３の範囲である。口金吐出孔の形状は、紡糸における可紡性および吐出時の安定性の観点から、上記範囲となる形状が好ましい。 The shape of the die discharge hole used in the present invention is preferably such that the hole diameter D is in the range of 0.05 to 5.0 mm. When it is larger than 0.05 mm, the yarn-making property is improved, and when it is smaller than 5.0 mm, yarn breakage is reduced. More preferably, the hole diameter D is in the range of 0.08 to 1.0 mm, and is 0.2 to 0.8 mm. More preferably, the hole depth L is in the range of 0.1 to 5 mm, and the hole depth L is in the range of 0.16 to 3 mm. When the hole depth L is 0.1 mm or more, the yarn-making property is improved, and when the hole depth L is 5 mm or less, the pressure at the time of discharge is preferable. L / D is preferably in the range of 1.5-4. L / D is in the range of 2-3. The shape of the die discharge hole is preferably in the above range from the viewpoints of spinnability in spinning and stability during discharge.
本発明において、凝固浴には、凝固促進成分を含ませることができ、凝固浴の温度および凝固促進成分の濃度によって、凝固速度を制御することができる。凝固促進成分としては、前記ポリアクリロニトリル系重合体を溶解せず、かつ紡糸原液に用いる溶媒と相溶性があるものが使用できる。紡糸原液の溶媒として用いたジメチルスルホキシド、ジメチルホルムアミドおよびジメチルアセトアミドなどの溶媒、チオシアン酸ナトリウム、塩化亜鉛などの無機化合物と、凝固促進成分の併用をしても良いし、凝固促進成分を単独で用いることもできる。 In the present invention, the coagulation bath can contain a coagulation promoting component, and the coagulation rate can be controlled by the temperature of the coagulation bath and the concentration of the coagulation promoting component. As the coagulation accelerating component, a component that does not dissolve the polyacrylonitrile polymer and is compatible with the solvent used in the spinning dope can be used. A coagulation promoting component may be used in combination with a solvent such as dimethyl sulfoxide, dimethylformamide and dimethylacetamide used as a solvent for the spinning dope, an inorganic compound such as sodium thiocyanate, zinc chloride, or the coagulation promoting component alone. You can also.
凝固浴組成を選択し、紡糸原液を凝固浴にて凝固したときに紡糸原液の溶媒が凝固した繊維から急速な脱離や分離を促進せずに、繊維の緻密化を進ませることで、ポリアクリロニトリル系繊維の延伸、耐炎化、炭化工程において糸切れが少なくすることができ、生産性が向上するため好ましい。具体的な凝固剤としてメタノール、エタノール、プロパノール、エチレングリコール、プロピレングリコール、テトラメチレングリコール及びポリエチレングリコール、ポリプロピレングリコール、ポリテトラメチレングリコール、水が挙げられる。その中でもエタノール、水を使用することが好ましい。 By selecting the coagulation bath composition, the spinning solution is coagulated in the coagulation bath and the solvent of the spinning solution does not promote rapid detachment or separation from the coagulated fiber, thereby promoting fiber densification. In the drawing, flameproofing, and carbonization processes of acrylonitrile fiber, thread breakage can be reduced, which is preferable because productivity is improved. Specific examples of the coagulant include methanol, ethanol, propanol, ethylene glycol, propylene glycol, tetramethylene glycol and polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and water. Of these, ethanol and water are preferably used.
凝固浴温度は−３０℃〜５０℃であることが好ましい。選択した凝固浴組成との組み合わせにより、凝固速度を制御することができる。−５℃〜１０℃の範囲であることがより好ましい。 The coagulation bath temperature is preferably -30 ° C to 50 ° C. Depending on the combination with the selected coagulation bath composition, the coagulation rate can be controlled. More preferably, it is in the range of −5 ° C. to 10 ° C.
本発明では、吐出された糸条物を凝固浴中に導入して凝固した後、耐炎化までのいずれかの工程において、延伸を行う。 In the present invention, after the discharged yarn is introduced into a coagulation bath and coagulated, stretching is performed in any step up to flame resistance.
本発明におけるポリアクリロニトリル系繊維の全延伸倍率は２０〜１２０である。全延伸倍率が２０未満であると、ポリアクリロニトリル系繊維の強度が低下し、続く耐炎化工程において、高張力での処理で糸切れがみられ、工程通過性が低下する。また、ポリアクリロニトリル系繊維の最終巻取り速度が下がるため、生産性が低下する。また、全延伸倍率を１２０より大きくなると、残留伸度が低くなり毛羽等の発生が多く、耐炎化、炭化での工程通過性が低下する。全延伸倍率は４０倍以上が好ましく、１００倍以下が好ましい。また、全延伸倍率は６０倍以上がより好ましい。 The total draw ratio of the polyacrylonitrile fiber in the present invention is 20 to 120. When the total draw ratio is less than 20, the strength of the polyacrylonitrile fiber is lowered, and in the subsequent flame resistance process, thread breakage is observed due to high tension treatment, and process passability is lowered. Moreover, since the final winding speed | velocity | rate of polyacrylonitrile-type fiber falls, productivity falls. On the other hand, when the total draw ratio is larger than 120, the residual elongation is lowered and fluff and the like are often generated, and the process passability in flame resistance and carbonization is lowered. The total draw ratio is preferably 40 times or more, and preferably 100 times or less. The total draw ratio is more preferably 60 times or more.
延伸時においては、糸の表面温度が２０℃以上２５０℃以下となるように加熱することが好ましい。延伸時の糸の表面温度が２０℃以上の場合、供給糸の予熱が十分であり、延伸時の均一な熱変形を可能とし繊度斑が低減する。さらには延伸張力を下げることができ、糸切れが少ないスムーズな延伸が可能となる。供給糸の軟化を良好にすることにより延伸張力を低下させ、よりスムーズな延伸を行うためには、延伸時の糸の表面温度が３０℃以上２００℃以下となるように加熱することがより好ましい。 At the time of drawing, it is preferable to heat the yarn so that the surface temperature of the yarn is 20 ° C. or higher and 250 ° C. or lower. When the surface temperature of the yarn at the time of drawing is 20 ° C. or higher, preheating of the supplied yarn is sufficient, and uniform thermal deformation at the time of drawing is possible, and fineness unevenness is reduced. Furthermore, the stretching tension can be lowered, and smooth stretching with little yarn breakage becomes possible. In order to reduce the stretching tension by improving the softening of the supply yarn and perform smoother stretching, it is more preferable to heat the yarn so that the surface temperature of the yarn during stretching is 30 ° C. or more and 200 ° C. or less. .
ここで、延伸を容易にさせうるための延伸時の糸の加熱手法は、供給ローラーと延伸ローラー間で実施されるものであって、走行糸条を直接的あるいは間接的に加熱させうる装置であれば特に限定はされない。具体的な加熱手法としては、加熱ローラー、熱ピン、熱板、水あるいは有機化合物などの液体浴、空気あるいは蒸気などの気体浴、レーザーなどが挙げられる。加熱温度の制御、走行糸条への均一な加熱、装置が複雑にならない観点から加熱ローラー、水あるいは有機化合物などの液体浴、空気あるいは蒸気などの気体浴を加熱手法として用いることが好ましい。 Here, the heating method of the yarn at the time of drawing for facilitating drawing is performed between the supply roller and the drawing roller, and is an apparatus that can directly or indirectly heat the running yarn. If there is no particular limitation. Specific heating methods include a heating roller, a heat pin, a hot plate, a liquid bath such as water or an organic compound, a gas bath such as air or steam, and a laser. It is preferable to use a heating roller, a liquid bath such as water or an organic compound, or a gas bath such as air or steam as a heating method from the viewpoint of controlling the heating temperature, uniformly heating the running yarn, and not complicating the apparatus.
水あるいは有機化合物などの液体浴加熱手法として用いる方法として、浴中延伸を採用できる。水、有機溶剤などで繊維を膨潤させることで比較的に低い温度でも安定した延伸を行うことができて好ましい。好ましくは３０〜９８℃の範囲の温度に温調された水あるいはメタノール、エタノールなど凝固剤として用いた有機化合物、紡糸原液に用いたジメチルホルムアミド、ジメチルアセトアミド、ジメチルスルホキシドなどに代表される有機化合物を単独あるいは混合物中に糸条を通過させ延伸することができる。この工程では単一または複数の延伸浴を用いることができ、この工程は後述する洗浄工程と組み合わせても良いし、洗浄工程の後に行っても良い。 In-bath stretching can be employed as a method for heating a liquid bath of water or an organic compound. Swelling the fiber with water, an organic solvent or the like is preferable because stable stretching can be performed even at a relatively low temperature. Preferably, water or water adjusted to a temperature in the range of 30 to 98 ° C., organic compounds used as coagulants such as methanol and ethanol, and organic compounds typified by dimethylformamide, dimethylacetamide, dimethyl sulfoxide and the like used for the spinning dope The yarn can be stretched by passing it alone or in a mixture. In this step, a single or a plurality of stretching baths can be used, and this step may be combined with a cleaning step described later, or may be performed after the cleaning step.
蒸気などの気体浴を加熱手法として用いる方法として、加圧スチーム延伸を採用できる。既存の方法を採用することができるが、単繊維同士が接着しない、かつ延伸性の観点から１２０〜１９０℃の範囲の温度で行うことが好ましい。 As a method of using a gas bath such as steam as a heating method, pressurized steam stretching can be employed. Although an existing method can be adopted, it is preferable to carry out at a temperature in the range of 120 to 190 ° C. from the viewpoint of stretchability in which single fibers do not adhere to each other.
また、空気などの気体浴を加熱手法として用いる方法として、ホットチューブを用いた延伸を採用できる。延伸性の観点から１３０〜２００℃の温度で行うことが好ましい。 In addition, as a method of using a gas bath such as air as a heating method, stretching using a hot tube can be employed. It is preferable to carry out at the temperature of 130-200 degreeC from a ductile viewpoint.
加熱ローラーを用いる場合には、加熱ローラーが供給ローラーを兼ねることが最も効果的であり、加熱ローラーの温度は１３０℃〜２００℃の温度が好ましい。 When using a heating roller, it is most effective that the heating roller also serves as a supply roller, and the temperature of the heating roller is preferably 130 ° C to 200 ° C.
延伸は上述した延伸方法を１種以上組み合わせて実施することができる。例えば、浴延伸及びスチーム延伸を組み合わせることが好ましく用いられる手法である。 Stretching can be performed by combining one or more of the stretching methods described above. For example, a combination of bath stretching and steam stretching is preferably used.
全延伸倍率が上述の通りになれば良く、１段の延伸で２０〜１２０倍の延伸を行っても良いし、複数の延伸を組み合わせて実施しても良い。延伸の均一性の点から、１段あたりの延伸倍率は１．０１〜１５倍が好ましく、２〜１０倍がより好ましい。 It is sufficient that the total stretching ratio is as described above, and 20-120 times of stretching may be performed by one-stage stretching, or a plurality of stretching may be combined. From the standpoint of stretching uniformity, the draw ratio per stage is preferably 1.01 to 15 times, and more preferably 2 to 10 times.
本発明において、延伸に加えて洗浄工程、油剤付与工程および乾燥熱処理工程を適宜組み込むことができる。 In the present invention, in addition to stretching, a washing step, an oil agent application step, and a drying heat treatment step can be appropriately incorporated.
洗浄工程は、凝固剤として水を用いた場合には凝固後の繊維から、紡糸原液から残存した溶媒および凝固浴から持ち出した水と溶媒を除去する手段として、凝固浴から引き取った直後に水洗工程として組み込むことが好適である。凝固剤としてメタノール、エタノールなどの有機化合物を用いた場合には、水の代りに有機化合物を用いて洗浄を行うことができる。 When water is used as the coagulant, the washing process is a process for removing the solvent remaining from the spinning dope and the water taken out of the coagulation bath and the solvent from the coagulated fiber immediately after taking it out of the coagulation bath. Is preferably incorporated as When an organic compound such as methanol or ethanol is used as the coagulant, cleaning can be performed using the organic compound instead of water.
油剤付与工程は、工程通過性およびハンドリング性を向上させる上で好適である。耐炎化処理および炭化処理の初期において単繊維同士が接着することがあり、その接着を防止する目的から、シリコーン等からなる油剤を付与することが好ましい。かかるシリコーンとしては、変性されたシリコーンを用いることが好ましく、耐熱性の高いアミノ変性シリコーンを用いることが好ましい。 The oil agent application step is suitable for improving process passability and handling properties. In the initial stage of the flameproofing treatment and carbonization treatment, the single fibers may adhere to each other, and for the purpose of preventing the adhesion, it is preferable to apply an oil agent made of silicone or the like. As such silicone, modified silicone is preferably used, and amino-modified silicone having high heat resistance is preferably used.
乾燥熱処理工程は、洗浄工程または浴中延伸工程における水、有機化合物等を乾燥し、併せて繊維の緻密化を行う工程であり、短時間で効率よく乾燥できれば接触方式と非接触方式のどちらの方式でも良く、単繊維同士が接着しない、かつ乾燥効率の観点から１２０〜１９０℃の範囲の温度で行うことが好ましい。 The drying heat treatment process is a process of drying water, organic compounds, etc. in the washing process or stretching process in the bath, and simultaneously densifying the fibers. If it can be efficiently dried in a short time, either the contact method or the non-contact method A method may be used, and it is preferable to carry out at a temperature in the range of 120 to 190 ° C. from the viewpoint of drying efficiency, in which single fibers do not adhere to each other.
ポリアクリロニトリル系重合体を用いた前駆体繊維の単繊維繊度は０．３〜１．３ｄｔｅｘであることが好ましい。単繊維繊度が０．３ｄｔｅｘより大きいと孔径の小さい口金から紡糸原液を吐出させる必要がなく、小異物などによる口金孔詰まりや、凝固工程での随伴流の影響による単繊維切れが回避でき、前駆体繊維の品位が低下したり、洗浄、延伸といった製糸工程におけるローラーへの巻き付きが発生しにくくなるという問題がある。一方、単繊維繊度が１．３ｄｔｅｘより小さくすることで、単繊維内部への耐炎化処理が十分となり、その不十分な部分が炭化工程で糸切れを引き起こしにくく生産性が向上する。単繊維繊度は、さらに好ましくは０．６〜０．９ｄｔｅｘである。 The single fiber fineness of the precursor fiber using a polyacrylonitrile-based polymer is preferably 0.3 to 1.3 dtex. When the single fiber fineness is larger than 0.3 dtex, it is not necessary to discharge the spinning dope from a die having a small pore diameter, and it is possible to avoid clogging of the die due to small foreign matter and the occurrence of single fiber breakage due to the accompanying flow in the coagulation process. There is a problem that the quality of the body fiber is lowered, and winding around the roller in the yarn making process such as washing and drawing is less likely to occur. On the other hand, when the single fiber fineness is smaller than 1.3 dtex, the flameproofing treatment to the inside of the single fiber becomes sufficient, and the insufficient portion hardly causes thread breakage in the carbonization step, and the productivity is improved. The single fiber fineness is more preferably 0.6 to 0.9 dtex.
本発明において、前駆体繊維束の全フィラメント数は１００〜１００００００の範囲であることが好ましい。また、全フィラメント数は１００００〜１０００００の範囲であることがより好ましい。フィラメント数が１００以上であることで一度に大量のポリマーを繊維化できるため生産性が向上し、１００００００以下であることで耐炎化や炭化処理において均一な処理ができるため生産性が向上する。 In the present invention, the total number of filaments in the precursor fiber bundle is preferably in the range of 100 to 1000000. The total number of filaments is more preferably in the range of 10,000 to 100,000. When the number of filaments is 100 or more, a large amount of polymer can be made into fibers at a time, so that productivity is improved. When it is 1000000 or less, productivity can be improved because uniform treatment can be performed in flame resistance and carbonization treatment.
本発明において、上記の方法により得られるポリアクリルニトリル系繊維を、空気中で２００〜３００℃の範囲の温度で耐炎化した後、３００〜８００℃の不活性雰囲気下において予備炭化処理し、引き続き不活性雰囲気中で８００〜２０００℃の範囲の温度で炭化処理する。いずれの温度も糸近傍の雰囲気温度を測定することにより求められる。 In the present invention, the polyacrylonitrile fiber obtained by the above method is flame-resistant in air at a temperature in the range of 200 to 300 ° C., and then pre-carbonized in an inert atmosphere of 300 to 800 ° C. Carbonization is performed at a temperature in the range of 800 to 2000 ° C. in an inert atmosphere. Both temperatures are determined by measuring the ambient temperature near the yarn.
耐炎化温度は２００〜３００℃であり、２４０℃〜２７０℃が好ましい。３００℃を超えると前駆体繊維に付与された油剤の分解消失が始まるため、耐炎化処理時に単繊維同士が融着しやすくなると共に、糸束内で耐炎化のムラが生じやすくなり、耐炎化度のムラの指標である蟻酸溶解度が高くなる。２００℃より低くなると耐炎化終了まで要する時間が延びるため生産性の観点から好ましくない。 The flameproofing temperature is 200 to 300 ° C, preferably 240 to 270 ° C. When the temperature exceeds 300 ° C., decomposition and disappearance of the oil agent applied to the precursor fiber starts, so that the single fibers are easily fused to each other at the time of the flame resistance treatment, and uneven flame resistance is easily generated in the yarn bundle. Formic acid solubility, which is an indicator of the degree of unevenness, increases. If it is lower than 200 ° C., it takes a long time to complete the flame resistance, which is not preferable from the viewpoint of productivity.
得られる耐炎化繊維の比重が好ましくは１．３〜１．５の範囲となるように設定することが、続く炭化処理での工程通過性を向上する目的から好ましい態様である。比重が１．３より低いと単繊維内部の耐炎化処理が不十分であるために予備炭化処理での糸切れが発生しやすい問題がある。１．５より高いと単繊維表面の酸化が進みすぎるため、予備炭化糸強度が低下しやすい問題がある。比重のより好ましい範囲は１．３７〜１．４０である。 Setting the specific gravity of the obtained flame-resistant fiber to be preferably in the range of 1.3 to 1.5 is a preferred embodiment for the purpose of improving process passability in the subsequent carbonization treatment. When the specific gravity is lower than 1.3, there is a problem that yarn breakage is likely to occur in the preliminary carbonization treatment because the flameproofing treatment inside the single fiber is insufficient. If it is higher than 1.5, the oxidation of the surface of the single fiber proceeds too much, so that there is a problem that the pre-carbonized yarn strength tends to be lowered. A more preferable range of specific gravity is 1.37 to 1.40.
耐炎糸の比重はＪＩＳ Ｒ７６０１（１９８６）記載の方法に従って求めることができる。測定方法として液置換法を用い、浸せき液としてエタノールを精製せずに用いた。１．０〜１．５ｇの繊維を採取し、１２０℃で２時間絶乾する。絶乾質量Ａ（ｇ）を測定した後、比重既知（比重ρ）のエタノールに含浸し、エタノール中の繊維質量Ｂ（ｇ）を測定し、繊維比重＝（Ａ×ρ）／（Ａ−Ｂ）により繊維比重を求めることができる。 The specific gravity of the flame resistant yarn can be determined according to the method described in JIS R7601 (1986). A liquid replacement method was used as a measurement method, and ethanol was used without purification as an immersion liquid. 1.0 to 1.5 g of fiber is collected and dried at 120 ° C. for 2 hours. After measuring the absolute dry mass A (g), it was impregnated with ethanol with a known specific gravity (specific gravity ρ), and the fiber mass B (g) in the ethanol was measured. Fiber specific gravity = (A × ρ) / (A−B ) To obtain the specific gravity of the fiber.
耐炎化の時間は、処理温度に応じて適宜選択することができるが、耐炎化処理時間は１〜５００分が望ましい。生産性の面からは耐炎化処理時間は短い方がよいが５０分を下回ると、各単繊維についての前記した二重構造が全体的に顕著となり、本発明の効果が得られにくくなることがある。また耐炎化処理時間が５００分を超えると単繊維の表層の酸化が進行しすぎるため、炭素繊維の引張強度が著しく低下する問題がある。さらに好ましくは５０〜１５０分、より好ましくは８０〜１２０分である。この耐炎化処理時間とは、糸条が耐炎化炉内に滞留している全時間をいう。 The flameproofing time can be appropriately selected depending on the treatment temperature, but the flameproofing time is preferably 1 to 500 minutes. From the standpoint of productivity, the flameproofing treatment time should be short, but if it is less than 50 minutes, the above-mentioned double structure for each single fiber becomes conspicuous as a whole, and the effects of the present invention may not be obtained. is there. Further, if the flameproofing treatment time exceeds 500 minutes, the oxidation of the surface layer of the single fiber proceeds excessively, and there is a problem that the tensile strength of the carbon fiber is remarkably lowered. More preferably, it is 50 to 150 minutes, More preferably, it is 80 to 120 minutes. This flameproofing treatment time means the total time that the yarn stays in the flameproofing furnace.
耐炎化工程における張力は０．２〜１．０ｃＮ／ｄｔｅｘであることが好ましい。０．２ｃＮ／ｄｔｅｘ以上であることで、耐炎糸の物性が向上し、続く炭化処理での工程通過性が向上するため好ましい。１．０ｃＮ／ｄｔｅｘ以下であることで、耐炎化での毛羽の発生及び糸切れが発生しにくくなり、安定して工程を通過することができるため生産性が向上するため好ましい。より好ましくは０．３〜０．６ｃＮ／ｄｔｅｘ、さらに好ましくは０．３〜０．３５ｃＮ／ｄｔｅｘである。ここで耐炎化工程における張力とは耐炎化炉出側のロールで測定した張力（ｃＮ）をポリアクリロニトリル系繊維の繊維束の絶乾時の繊度（ｄｔｅｘ）で割った値を示す。 The tension in the flameproofing step is preferably 0.2 to 1.0 cN / dtex. It is preferable for it to be 0.2 cN / dtex or more because the physical properties of the flame resistant yarn are improved and the process passability in the subsequent carbonization treatment is improved. When it is 1.0 cN / dtex or less, generation of fuzz due to flame resistance and yarn breakage are less likely to occur, and since the process can be stably passed, productivity is improved, which is preferable. More preferably, it is 0.3-0.6 cN / dtex, More preferably, it is 0.3-0.35 cN / dtex. Here, the tension in the flameproofing step refers to a value obtained by dividing the tension (cN) measured with the roll on the exit side of the flameproofing furnace by the fineness (dtex) of the polyacrylonitrile fiber bundle when dry.
耐炎化工程における糸条の延伸比は０．８５〜１．２０が良く、０．８５〜１．１０がより好ましく、０．８８〜１．０６がさらに好ましく、０．９２〜１．０２がさらに好ましい。 The draw ratio of the yarn in the flameproofing step is preferably 0.85 to 1.20, more preferably 0.85 to 1.10, further preferably 0.88 to 1.06, and 0.92 to 1.02. Further preferred.
耐炎化処理に引き続き、不活性雰囲気中で予備炭化処理、炭化処理することにより炭素繊維が得られる。不活性雰囲気としては、例えば、窒素、アルゴンおよびキセノンなどが好ましく例示でき、経済的な観点からは窒素が好ましく用いられる。 Subsequent to the flameproofing treatment, carbon fiber is obtained by pre-carbonization treatment and carbonization treatment in an inert atmosphere. As an inert atmosphere, nitrogen, argon, xenon etc. can be illustrated preferably, for example, and nitrogen is preferably used from an economical viewpoint.
炭化処理は、３００〜８００℃の範囲の温度と８００〜２０００℃の範囲の温度領域で異なる反応が起こっているために、予備炭化処理、炭化処理と分けて行う。 The carbonization treatment is performed separately from the preliminary carbonization treatment and the carbonization treatment because different reactions occur in the temperature range of 300 to 800 ° C and the temperature range of 800 to 2000 ° C.
予備炭化処理の温度は３００〜８００℃である。３００℃以上とすることで、炭素結晶成長が十分となり、引き続いて行われる炭化処理後に十分な強力を有する炭素繊維を得られる。また、最高温度が８００℃以下では炭素構造変化に伴う炭素繊維からの窒素ガスの排出が開始されないため、炉の排気系統が複雑とならないため好ましい。予備炭化処理の最高温度は、より好ましくは６００〜７５０℃である。また３００℃〜４００℃領域の滞留時間は１〜３分であることが好ましく、４００〜５００℃の昇温速度は１０〜５００℃／分、より好ましくは２０〜１５０℃／分とするのが好ましい。 The temperature of the preliminary carbonization treatment is 300 to 800 ° C. By adjusting the temperature to 300 ° C. or higher, carbon crystal growth is sufficient, and carbon fibers having sufficient strength can be obtained after the subsequent carbonization treatment. Moreover, since the discharge | emission of nitrogen gas from the carbon fiber accompanying a carbon structure change is not started when the maximum temperature is 800 degrees C or less, since the exhaust system of a furnace does not become complicated, it is preferable. The maximum temperature of the preliminary carbonization treatment is more preferably 600 to 750 ° C. The residence time in the 300 ° C to 400 ° C region is preferably 1 to 3 minutes, and the temperature rising rate at 400 to 500 ° C is 10 to 500 ° C / min, more preferably 20 to 150 ° C / min. preferable.
予備炭化処理後の繊維の比重を好ましくは１．５〜１．７とするように温度と時間を設定することが、続く炭化工程通過性から好ましい態様である。予備炭化処理後の繊維の比重は、浸せき液としてo-ジクロロベンゼンを用いる他は、耐炎糸の比重と同様に求めることができる。 Setting the temperature and time so that the specific gravity of the fiber after the pre-carbonization treatment is preferably 1.5 to 1.7 is a preferable aspect from the subsequent carbonization process passability. The specific gravity of the fiber after the preliminary carbonization treatment can be obtained in the same manner as the specific gravity of the flame resistant yarn, except that o-dichlorobenzene is used as the immersion liquid.
炭化処理は８００〜２０００℃の温度範囲で行われる。８００℃以上であることで、炭化処理が繊維内部まで進み、２０００℃以下であることで引張強度が高く、工程通過性が高い炭素繊維が得られることで好ましい。炭化処理の最高温度は１２００〜１６００℃が好ましく、所望する炭素繊維の力学物性に応じて適宜設定するのがよい。一般に炭化処理の最高温度が高いほど、得られる炭素繊維の引張弾性率が高くなるものの、引張強度は１５００℃付近で極大となる。 The carbonization treatment is performed in a temperature range of 800 to 2000 ° C. When the temperature is 800 ° C. or higher, carbonization proceeds to the inside of the fiber, and when the temperature is 2000 ° C. or lower, carbon fiber having high tensile strength and high process passability is preferable. The maximum temperature of the carbonization treatment is preferably 1200 to 1600 ° C., and is suitably set according to the desired mechanical properties of the carbon fiber. In general, the higher the maximum temperature for carbonization, the higher the tensile modulus of the carbon fiber obtained, but the tensile strength becomes maximum at around 1500 ° C.
また、本発明において、炭化工程における張力は０．５〜３．０ｃＮ／ｄｔｅｘであることが好ましい。０．５ｃＮ／ｄｔｅｘ以上であることで引張弾性率の向上があり、炭化時の糸切れが少なく生産性が向上する。逆に張力が３．０ｃＮ／ｄｔｅｘ以下であることで毛羽や糸切れが発生しにくくなり、安定して工程を通過することができる。かかる張力は、下限として、より好ましくは０．６ｃＮ／ｄｔｅｘ以上であるのが良く、上限として、より好ましくは１．６ｃＮ／ｄｔｅｘ以下、さらに好ましくは１．５ｃＮ／ｄｔｅｘ以下、最も好ましくは１．１ｃＮ／ｄｔｅｘ以下であるのが良い。ここで炭化工程における張力とは炭化炉出側のロールで測定した張力（ｃＮ）を予備炭化繊維束の絶乾時の繊度（ｄｔｅｘ）で割った値を示す。 In the present invention, the tension in the carbonization step is preferably 0.5 to 3.0 cN / dtex. When it is 0.5 cN / dtex or more, the tensile elastic modulus is improved, the yarn breakage during carbonization is small, and the productivity is improved. Conversely, when the tension is 3.0 cN / dtex or less, fluff and yarn breakage are less likely to occur, and the process can be stably passed. The tension is preferably 0.6 cN / dtex or more as a lower limit, more preferably 1.6 cN / dtex or less, still more preferably 1.5 cN / dtex or less, and most preferably 1. It is good that it is 1 cN / dtex or less. Here, the tension in the carbonization step indicates a value obtained by dividing the tension (cN) measured by the roll on the exit side of the carbonization furnace by the fineness (dtex) of the preliminary carbonized fiber bundle when it is completely dried.
高温領域での炭化処理の処理時間は、処理温度に応じて適宜選択することができるが、得られる炭素繊維の比重が好ましくは１．７６〜１．８７の範囲となるように、より好ましくは１．７７〜１．８６となるように設定する。かかる比重が小さすぎる場合には、炭化処理が不十分なために、得られる炭素繊維において発現する物性が低くなることがあり、逆に比重が大きすぎる場合には、脆性が顕著となるために擦過に弱くなり、品位および工程通過性が低下することがある。炭素繊維の比重は、浸せき液としてo-ジクロロベンゼンを用いる他は、耐炎糸の比重と同様に求めることができる。 The treatment time of the carbonization treatment in the high temperature region can be appropriately selected according to the treatment temperature, but it is more preferred that the specific gravity of the obtained carbon fiber is preferably in the range of 1.76 to 1.87. It sets so that it may become 1.77-1.86. When the specific gravity is too small, the carbonization treatment is insufficient, so that the physical properties expressed in the obtained carbon fiber may be low. Conversely, when the specific gravity is too large, brittleness becomes remarkable. It may be weakened by rubbing, and the quality and processability may deteriorate. The specific gravity of the carbon fiber can be obtained in the same manner as the specific gravity of the flame resistant yarn, except that o-dichlorobenzene is used as the immersion liquid.
得られた炭素繊維は、その表面改質のため、電解処理することができる。電解処理に用いられる電解液には、例えば、硫酸、硝酸および塩酸等の酸性溶液や、水酸化ナトリウム、水酸化カリウム、テトラエチルアンモニウムヒドロキシド、炭酸アンモニウムおよび重炭酸アンモニウムのようなアルカリまたはそれらの塩を水溶液として使用することができる。ここで、電解処理に要する電気量は、適用する炭素繊維の炭化度に応じて適宜選択することができる。かかる電解処理により、炭素繊維を用いて得られる複合材料において、炭素繊維とマトリックスとの接着性を適正化することができ、接着が強すぎることによる複合材料のブリトルな破壊や、繊維方向の引張強度が低下する問題や、繊維方向における引張強度は高いものの、樹脂との接着性に劣り、非繊維方向における強度特性が発現しないという問題が解消され、得られる複合材料において、繊維方向と非繊維方向の両方向にバランスのとれた強度特性が発現されるようになる。 The obtained carbon fiber can be electrolytically treated for surface modification. Examples of the electrolytic solution used for the electrolytic treatment include acidic solutions such as sulfuric acid, nitric acid and hydrochloric acid, alkalis such as sodium hydroxide, potassium hydroxide, tetraethylammonium hydroxide, ammonium carbonate and ammonium bicarbonate, or salts thereof. Can be used as an aqueous solution. Here, the amount of electricity required for the electrolytic treatment can be appropriately selected according to the carbonization degree of the carbon fiber to be applied. By such electrolytic treatment, in the composite material obtained using carbon fiber, the adhesion between the carbon fiber and the matrix can be optimized, and the brittle fracture of the composite material due to excessive adhesion or the tensile in the fiber direction The problem that strength is reduced and the tensile strength in the fiber direction is high, but the problem of poor adhesion to the resin and the absence of strength properties in the non-fiber direction are solved. In the resulting composite material, the fiber direction and non-fiber Strength characteristics balanced in both directions are developed.
また、本発明の炭素繊維は、かかる電解処理の後、集束性を付与するため、サイジング処理を施されていても良い。サイジング剤には、使用する樹脂の種類に応じて、樹脂との相溶性の良いサイジング剤を適宜選択することができる。 In addition, the carbon fiber of the present invention may be subjected to a sizing treatment after the electrolytic treatment in order to impart convergence. As the sizing agent, a sizing agent having good compatibility with the resin can be appropriately selected according to the type of resin used.
本発明により得られる炭素繊維、プリプレグとしてオートクレーブ成形したり、織物などのプリフォームとしてレジントランスファーモールディングで成形したり、フィラメントワインディングで成形したりして、航空機部材、圧力容器部材、自動車部材、釣り竿、ゴルフシャフトなどのスポーツ部材として、好適に用いることができる。 Carbon fiber obtained by the present invention, autoclave molding as a prepreg, molding by resin transfer molding as a preform such as woven fabric, molding by filament winding, aircraft member, pressure vessel member, automobile member, fishing rod, It can be suitably used as a sports member such as a golf shaft.
以下、実施例により本発明をより詳細に説明する。実施例中の各特性値は、次の方法で求めたものである。
Ａ．極限粘度
予め１２０℃で２時間熱処理し絶乾したポリアクリロニトリル系繊維用重合体１５０ｍｇを、２５℃において５０ｍｌのチオシアン酸ナトリウム０．１ｍｏｌ／リットル添加Ｎ，Ｎ−ジメチルホルムアミド（いずれも和光純薬社製特級）に溶解した。得られた溶液を、２５℃の温水槽中で温調し、予め２５℃に温調してあるオストワルド粘度計を用いて標線間の落下時間を１／１００秒の精度で測定し、その時間をｔ（秒）とした。同様に、炭素繊維前駆体繊維用ポリアクリロニトリル系重合体を溶解していないチオシアン酸ナトリウム０．１ｍｏｌ／リットル添加Ｎ，Ｎ−ジメチルホルムアミドについても測定し、その落下時間をｔ０（秒）とした。次式を用いて極限粘度［η］を算出した。
［η］＝｛（１＋１．３２×ηｓｐ）１／２―１｝／０．１９８
ηｓｐ＝（ｔ／ｔ０）−１
Ｂ．紡糸原液中の重合体溶液の重合体濃度
紡糸原液１０ｇを２００ｍｌの水中に細く垂らすことにより、直径１ｍｍ以下の線状組織を得る。その後、９０℃の温度の熱水中で２時間脱溶媒して、１２０℃の温度で２時間乾燥させた後、線状組織を計量した。次式を用いて、紡糸溶液の重合体濃度（重量％）を求めた。
重合体濃度＝｛（乾燥後の線状組織重量）／（脱溶媒前の重合体溶液重量）｝×１００
Ｃ．繊度
ＪＩＳ Ｌ１０１７（２００２）８．３の方法で繊度を測定した。
Ｄ．生産性の向上
ポリアクリロニトリル系繊維の製造工程、耐炎化、炭化工程における工程通過性及びポリアクリロニトリル系繊維の全延伸倍率の４つを用いて判断を行った。
Hereinafter, the present invention will be described in more detail with reference to examples. Each characteristic value in the examples is obtained by the following method.
A. Intrinsic Viscosity 150 mg of polyacrylonitrile fiber polymer that had been heat-treated at 120 ° C. for 2 hours in advance and dried at 25 ° C. with 50 ml of sodium thiocyanate 0.1 mol / liter added N, N-dimethylformamide (Special grade). The obtained solution was temperature-controlled in a hot water bath at 25 ° C., and the drop time between the marked lines was measured with an accuracy of 1/100 second using an Ostwald viscometer that was temperature-controlled at 25 ° C. in advance. The time was t (seconds). Similarly, sodium thiocyanate 0.1 mol / liter added N, N-dimethylformamide in which the polyacrylonitrile polymer for carbon fiber precursor fiber was not dissolved was also measured, and the drop time was defined as t0 (seconds). The intrinsic viscosity [η] was calculated using the following formula.
[Η] = {(1 + 1.32 × ηsp) 1/2 −1} /0.198
ηsp = (t / t0) −1
B. Polymer Concentration of Polymer Solution in Spinning Stock Solution A linear structure having a diameter of 1 mm or less is obtained by dripping 10 g of spinning stock solution into 200 ml of water. Thereafter, the solvent was removed in hot water at a temperature of 90 ° C. for 2 hours and dried at a temperature of 120 ° C. for 2 hours, and then the linear structure was weighed. The polymer concentration (% by weight) of the spinning solution was determined using the following formula.
Polymer concentration = {(weight of linear structure after drying) / (weight of polymer solution before solvent removal)} × 100
C. Fineness Fineness was measured by the method of JIS L1017 (2002) 8.3.
D. Improvement of productivity Judgment was carried out using the production process of polyacrylonitrile fiber, flame resistance, process passability in carbonization process, and total draw ratio of polyacrylonitrile fiber.
工程通過性は、問題のないものを○、多少の糸切れがあるが問題のないレベルを△、顕著な糸切れのためサンプルが得られない場合を×とした。 The passability of the process was evaluated as ○ when there was no problem, △ when there was some thread breakage but no problem, and × when the sample could not be obtained due to significant thread breakage.
ポリアクリロニトリル系繊維の全延伸倍率は２０倍以上延伸ができるものを生産性向上につながるとして○、２０倍未満しか延伸しないものを×とした。
いずれも良好の場合には生産性の向上◎、一つでも△があるものは○、一つでも×があるものは△、一つ以上の×及び△があるものを×とした。◎○を生産性の向上につながる技術とした。
The total draw ratio of the polyacrylonitrile-based fiber was evaluated as “◯” because it can be stretched by 20 times or more, which leads to improvement in productivity, and “X” when stretched less than 20 times.
When both were good, the productivity was improved. ◎, when there was at least one, ◯, when there was at least one, △, when there were one or more x and Δ, x. ◎ ○ is a technology that leads to productivity improvement.
[実施例１]
アクリロニトリル９９．８モル％、イタコン酸０．２モル％を水中でアゾビスイソブチロニトリルを重合開始剤、ポリビニルアルコールを安定剤として加え重合し、極限粘度１１のポリアクリロニトリル系重合体を得た。
[Example 1]
Acrylonitrile 99.8 mol% and itaconic acid 0.2 mol% were polymerized by adding azobisisobutyronitrile as a polymerization initiator and polyvinyl alcohol as a stabilizer in water to obtain a polyacrylonitrile polymer having an intrinsic viscosity of 11. .
ジメチルホルムアミド溶媒を攪拌しながら、得られたポリアクリロニトリル系重合体を混合し、目開き１０μｍのフィルター通過することで、原液中のポリアクリロニトリル系重合体濃度が５ｗｔ％の紡糸原液を得た。その紡糸原液を３０℃の温度で口金吐出孔径Ｄ０．９９ｍｍ、孔深度Ｌ２ｍｍの口金から、単孔吐出あたりの吐出量が５．７６ｍｌ／ｍｉｎになるように、空気中に押出し、３℃に温度コントロールしたエタノール溶液からなる凝固浴に導入する乾湿式紡糸法により、凝固糸条とした。この凝固糸条を、エタノール中で十分洗浄した後、１７０℃にコントロールしたホットチューブ中で延伸を行った。延伸倍率は４段（各４倍、２倍、２倍、１．４倍）で２２．４倍である。工程通過性は良好で、全延伸倍率も２２．４倍と高いものであった。 The obtained polyacrylonitrile polymer was mixed while stirring the dimethylformamide solvent, and passed through a filter having an opening of 10 μm to obtain a spinning dope having a polyacrylonitrile polymer concentration of 5 wt% in the stock solution. The spinning dope is extruded into air at a temperature of 30 ° C. from a die having a nozzle discharge hole diameter D of 0.99 mm and a hole depth of L 2 mm so that the discharge amount per single hole discharge is 5.76 ml / min. A coagulated yarn was obtained by a dry and wet spinning method introduced into a coagulation bath composed of a controlled ethanol solution. The coagulated yarn was thoroughly washed in ethanol and then stretched in a hot tube controlled at 170 ° C. The draw ratio is 42.4 (each 4 times, 2 times, 2 times, 1.4 times) and 22.4 times. The process passability was good and the total draw ratio was as high as 22.4 times.
続いて、得られたポリアクリロニトリル系繊維を、２４０℃の空気中で耐炎化張力０．３ｃＮ／ｄｔｅｘで８０分耐炎化処理を行ったところ、糸切れなく耐炎化繊維が得られた、耐炎化処理での工程通過性は良好であった。 Subsequently, the obtained polyacrylonitrile fiber was subjected to a flame resistance treatment in air at 240 ° C. with a flame resistance tension of 0.3 cN / dtex for 80 minutes. As a result, a flame resistant fiber was obtained without breakage. The process passability in the treatment was good.
得られた耐炎化繊維を、２００℃から４００℃に２分で昇温し、４００〜５００℃を４０秒で昇温し、最高温度７００℃で２分、延伸比１．１０で延伸しながら予備炭化処理して予備炭化糸を得た。 While the obtained flame-resistant fiber was heated from 200 ° C. to 400 ° C. in 2 minutes, the temperature was raised from 400 to 500 ° C. in 40 seconds, while being stretched at a maximum temperature of 700 ° C. for 2 minutes and a draw ratio of 1.10. Precarbonized yarn was obtained by precarbonization.
この予備炭化糸を最高温度１５００℃で３分張力０．９ｃＮ／ｄｔｅｘの下で炭化処理することにより炭化糸を得た。炭化処理においても糸切れなく工程通過性が良好であった。 The pre-carbonized yarn was carbonized at a maximum temperature of 1500 ° C. under a tension of 0.9 cN / dtex for 3 minutes to obtain a carbonized yarn. In the carbonization treatment, the process passability was good without yarn breakage.
[実施例２]
ジメチルスルホキシド溶媒を攪拌しながら、実施例１で得られたポリアクリロニトリル系重合体を混合し、目開き１０μｍのフィルター通過することで原液中のポリアクリロニトリル系重合体濃度が３ｗｔ％の紡糸原液を得た。その紡糸原液を３０℃の温度で孔径Ｄ０．９９ｍｍ、孔深度Ｌ２ｍｍの口金から、単孔吐出あたりの吐出量が５．７６ｍｌ／ｍｉｎになるように、空気中に押出し、３℃に温度コントロールしたジメチルスルホキシド／水＝８０／２０からなる凝固浴に導入する乾湿式紡糸法により、凝固糸条とした。十分凝固した後、この凝固糸条を、７０℃の温水で２．４倍浴延伸を行った。その後、１７０℃にコントロールしたホットチューブ中で２段（２倍、２倍）で４倍延伸を行い、最後にスチーム延伸を５倍行った。工程通過性は良好で、全延伸倍率も４８倍と高いものであった。
[Example 2]
While stirring the dimethyl sulfoxide solvent, the polyacrylonitrile polymer obtained in Example 1 was mixed and passed through a filter having an opening of 10 μm to obtain a spinning stock solution having a polyacrylonitrile polymer concentration of 3 wt% in the stock solution. It was. The spinning dope was extruded into air at a temperature of 30 ° C. from a die having a hole diameter of D0.99 mm and a hole depth of L2 mm so that the discharge amount per single hole discharge was 5.76 ml / min, and the temperature was controlled at 3 ° C. A coagulated yarn was obtained by a dry and wet spinning method introduced into a coagulation bath comprising dimethyl sulfoxide / water = 80/20. After solidifying sufficiently, this coagulated yarn was subjected to 2.4 times bath drawing with warm water at 70 ° C. Thereafter, the film was stretched 4 times in 2 stages (2 times, 2 times) in a hot tube controlled at 170 ° C., and finally, steam stretching was performed 5 times. The process passability was good and the total draw ratio was as high as 48 times.
続いて、得られたポリアクリロニトリル系繊維を、２４０℃の空気中で耐炎化張力０．３１ｃＮ／ｄｔｅｘで８０分耐炎化処理を行ったところ、糸切れなく耐炎化繊維が得られた、耐炎化処理での工程通過性は良好であった。 Subsequently, the obtained polyacrylonitrile fiber was subjected to a flame resistance treatment in air at 240 ° C. with a flame resistance tension of 0.31 cN / dtex for 80 minutes. As a result, a flame resistant fiber was obtained without breakage. The process passability in the treatment was good.
得られた耐炎化繊維を、２００℃から４００℃に２分で昇温し、４００〜５００℃を４０秒で昇温し、最高温度７００℃で２分、延伸比１．１０で延伸しながら予備炭化処理して予備炭化糸を得た。 While the obtained flame-resistant fiber was heated from 200 ° C. to 400 ° C. in 2 minutes, the temperature was raised from 400 to 500 ° C. in 40 seconds, while being stretched at a maximum temperature of 700 ° C. for 2 minutes and a draw ratio of 1.10. Precarbonized yarn was obtained by precarbonization.
この予備炭化糸を最高温度１５００℃で３分、張力０．９ｃＮ／ｄｔｅｘの下で炭化処理することにより炭化糸を得た。炭化処理においても糸切れなく工程通過性が良好であった。 The preliminary carbonized yarn was carbonized at a maximum temperature of 1500 ° C. for 3 minutes under a tension of 0.9 cN / dtex to obtain a carbonized yarn. In the carbonization treatment, the process passability was good without yarn breakage.
[実施例３]
アクリロニトリル９９．８モル％、イタコン酸０．２モル％を水中でアゾビスイソブチロニトリルを重合開始剤、ポリビニルアルコールを安定剤として加え重合し、極限粘度１０のポリアクリロニトリル系重合体を得た。
[Example 3]
Acrylonitrile 99.8 mol% and itaconic acid 0.2 mol% were polymerized by adding azobisisobutyronitrile as a polymerization initiator and polyvinyl alcohol as a stabilizer in water to obtain a polyacrylonitrile polymer having an intrinsic viscosity of 10. .
ジメチルアセトアミド溶液を攪拌しながら、得られたポリアクリロニトリル系重合体を混合し、目開き１０μｍのフィルター通過することで、原液中のポリアクリロニトリル系重合体濃度が３ｗｔ％の紡糸原液を得た。その紡糸原液を３０℃の温度で孔径Ｄ０．９９ｍｍ、孔深度Ｌ２ｍｍの口金から、単孔吐出あたりの吐出量が５．７６ｍｌ／ｍｉｎになるように、空気中に押出し、３℃に温度コントロールしたエタノール溶液からなる凝固浴に導入する乾湿式紡糸法により、凝固糸条とした。この凝固糸条を、エタノール中で十分洗浄した後、エタノール浴中で２倍に延伸を行った。続いて、１７０℃にコントロールしたホットチューブ中で延伸を行った。延伸倍率は３段（４倍、２倍、２倍）で１６倍である。工程通過性は良好で、全延伸倍率も３２倍と高いものであった。 The obtained polyacrylonitrile polymer was mixed while stirring the dimethylacetamide solution, and passed through a filter having an opening of 10 μm to obtain a spinning dope having a polyacrylonitrile polymer concentration of 3 wt% in the stock solution. The spinning dope was extruded into air at a temperature of 30 ° C. from a die having a hole diameter of D0.99 mm and a hole depth of L2 mm so that the discharge amount per single hole discharge was 5.76 ml / min, and the temperature was controlled at 3 ° C. A coagulated yarn was obtained by a dry and wet spinning method introduced into a coagulation bath made of an ethanol solution. The coagulated yarn was thoroughly washed in ethanol and then stretched twice in an ethanol bath. Subsequently, stretching was performed in a hot tube controlled at 170 ° C. The draw ratio is 16 times in 3 steps (4 times, 2 times, 2 times). The process passability was good and the total draw ratio was as high as 32 times.
続いて、得られたポリアクリロニトリル系繊維を、２４０℃の空気中で耐炎化張力０．２５ｃＮ／ｄｔｅｘで８０分耐炎化処理を行ったところ、糸切れなく耐炎化繊維が得られた、耐炎化処理での工程通過性は良好であった。 Subsequently, the obtained polyacrylonitrile fiber was subjected to a flame resistance treatment in air at 240 ° C. with a flame resistance tension of 0.25 cN / dtex for 80 minutes. As a result, a flame resistant fiber was obtained without breakage. The process passability in the treatment was good.
得られた耐炎化繊維を、２００℃から４００℃に２分で昇温し、４００〜５００℃を４０秒で昇温し、最高温度７００℃で２分、延伸比１．１０で延伸しながら予備炭化処理して予備炭化糸を得た。 While the obtained flame-resistant fiber was heated from 200 ° C. to 400 ° C. in 2 minutes, the temperature was raised from 400 to 500 ° C. in 40 seconds, while being stretched at a maximum temperature of 700 ° C. for 2 minutes and a draw ratio of 1.10. Precarbonized yarn was obtained by precarbonization.
この予備炭化糸を最高温度１５００℃で３分、張力０．８ｃＮ／ｄｔｅｘの下で炭化処理することにより炭化糸を得た。炭化処理においても糸切れなく工程通過性が良好であった。 The preliminary carbonized yarn was carbonized at a maximum temperature of 1500 ° C. for 3 minutes under a tension of 0.8 cN / dtex to obtain a carbonized yarn. In the carbonization treatment, the process passability was good without yarn breakage.
[実施例４]
アクリロニトリル９９．８モル％、イタコン酸０．２モル％を水中でアゾビスイソブチロニトリルを重合開始剤、ポリビニルアルコールを安定剤として加え重合し、極限粘度７のポリアクリロニトリル系重合体を得た。
[Example 4]
Acrylonitrile 99.8 mol% and itaconic acid 0.2 mol% were polymerized by adding azobisisobutyronitrile as a polymerization initiator and polyvinyl alcohol as a stabilizer in water to obtain a polyacrylonitrile polymer having an intrinsic viscosity of 7. .
ジメチルアセトアミド溶液を攪拌しながら、得られたポリアクリロニトリル系重合体を混合し、目開き１０μｍのフィルター通過することで、原液中のポリアクリロニトリル系重合体濃度が８ｗｔ％の紡糸原液を得た。紡糸原液の粘度が高く溶解性が低かったが問題のないレベルであった。その紡糸原液を３０℃の温度で孔径Ｄ０．９９ｍｍ、孔深度Ｌ２ｍｍの口金から、単孔吐出あたりの吐出量が５．７６ｍｌ／ｍｉｎになるように、空気中に押出し、３℃に温度コントロールしたメタノール溶液からなる凝固浴に導入する乾湿式紡糸法により、凝固糸条とした。この凝固糸条を、メタノール中で十分洗浄した後、メタノール浴中で２倍に延伸を行った。続いて、１７０℃にコントロールしたホットチューブ中で延伸を行った。延伸倍率は３段（４倍、２倍、２倍）で１６倍である。若干糸切れがあったものの工程通過性はほぼ良好で、全延伸倍率も３２倍と高いものであった。 The obtained polyacrylonitrile polymer was mixed while stirring the dimethylacetamide solution, and passed through a filter having an opening of 10 μm to obtain a spinning dope having a polyacrylonitrile polymer concentration of 8 wt% in the stock solution. Although the spinning stock solution had high viscosity and low solubility, it was at a level with no problem. The spinning dope was extruded into air at a temperature of 30 ° C. from a die having a hole diameter of D0.99 mm and a hole depth of L2 mm so that the discharge amount per single hole discharge was 5.76 ml / min, and the temperature was controlled at 3 ° C. A coagulated yarn was obtained by a dry and wet spinning method introduced into a coagulation bath made of a methanol solution. The coagulated yarn was sufficiently washed in methanol and then stretched twice in a methanol bath. Subsequently, stretching was performed in a hot tube controlled at 170 ° C. The draw ratio is 16 times in 3 steps (4 times, 2 times, 2 times). Although there was some yarn breakage, the process passability was almost good and the total draw ratio was as high as 32 times.
続いて、得られたポリアクリロニトリル系繊維を、２４０℃の空気中で耐炎化張力０．２５ｃＮ／ｄｔｅｘで８０分耐炎化処理を行ったところ、糸切れなく耐炎化繊維が得られた、耐炎化処理での工程通過性は良好であった。 Subsequently, the obtained polyacrylonitrile fiber was subjected to a flame resistance treatment in air at 240 ° C. with a flame resistance tension of 0.25 cN / dtex for 80 minutes. As a result, a flame resistant fiber was obtained without breakage. The process passability in the treatment was good.
得られた耐炎化繊維を、２００℃から４００℃に２分で昇温し、４００〜５００℃を４０秒で昇温し、最高温度７００℃で２分、延伸比１．１０で延伸しながら予備炭化処理して予備炭化糸を得た。 While the obtained flame-resistant fiber was heated from 200 ° C. to 400 ° C. in 2 minutes, the temperature was raised from 400 to 500 ° C. in 40 seconds, while being stretched at a maximum temperature of 700 ° C. for 2 minutes and a draw ratio of 1.10. Precarbonized yarn was obtained by precarbonization.
この予備炭化糸を最高温度１５００℃で３分、張力０．８ｃＮ／ｄｔｅｘの下で炭化処理することにより炭化糸を得た。炭化処理においても糸切れなく工程通過性が良好であった。 The preliminary carbonized yarn was carbonized at a maximum temperature of 1500 ° C. for 3 minutes under a tension of 0.8 cN / dtex to obtain a carbonized yarn. In the carbonization treatment, the process passability was good without yarn breakage.
[実施例５]
実施例１と同様に得られたポリアクリロニトリル系繊維を用いて、耐炎化、予備炭化処理を実施した。
[Example 5]
Using the polyacrylonitrile fiber obtained in the same manner as in Example 1, flameproofing and preliminary carbonization were performed.
この予備炭化糸を最高温度１５００℃で３分、張力０．４ｃＮ／ｄｔｅｘの下で炭化処理することにより炭化糸を得た。炭化処理において糸切れが見られ工程通過性がやや劣るが、問題のないレベルであった。 The preliminary carbonized yarn was carbonized at a maximum temperature of 1500 ° C. for 3 minutes under a tension of 0.4 cN / dtex to obtain a carbonized yarn. Although the yarn breakage was observed in the carbonization treatment, the process passability was slightly inferior, but it was at a level without any problem.
[実施例６]
実施例１と同様に得られたポリアクリロニトリル系繊維を得た。
[Example 6]
A polyacrylonitrile fiber obtained in the same manner as in Example 1 was obtained.
続いて、得られたポリアクリロニトリル系繊維を、２４０℃の空気中で耐炎化張力０．１１／ｄｔｅｘで８０分耐炎化処理を行ったところ、糸切れなく耐炎化繊維が得られた、耐炎化処理での工程通過性は良好であった。 Subsequently, the obtained polyacrylonitrile fiber was subjected to a flame resistance treatment in air at 240 ° C. with a flame resistance tension of 0.11 / dtex for 80 minutes. As a result, the flame resistant fiber was obtained without breakage. The process passability in the treatment was good.
得られた耐炎化繊維を、２００℃から４００℃に２分で昇温し、４００〜５００℃を４０秒で昇温し、最高温度７００℃で２分、延伸比１．１０で延伸しながら予備炭化処理して予備炭化糸を得た。
この予備炭化糸を最高温度１５００℃で３分、張力０．８ｃＮ／ｄｔｅｘの下で炭化処理することにより炭化糸を得た。炭化処理において糸切れが見られたが、工程通過性がやや劣るが、問題のないレベルであった。
While the obtained flame-resistant fiber was heated from 200 ° C. to 400 ° C. in 2 minutes, the temperature was raised from 400 to 500 ° C. in 40 seconds, while being stretched at a maximum temperature of 700 ° C. for 2 minutes and a draw ratio of 1.10. Precarbonized yarn was obtained by precarbonization.
The preliminary carbonized yarn was carbonized at a maximum temperature of 1500 ° C. for 3 minutes under a tension of 0.8 cN / dtex to obtain a carbonized yarn. Although thread breakage was observed in the carbonization treatment, the process passability was slightly inferior, but it was at a level with no problem.
[実施例７]
ジメチルホルムアミド溶液を攪拌しながら、実施例１で得られたポリアクリロニトリル系重合体を混合し、目開き１０μｍのフィルター通過することで、原液中のポリアクリロニトリル系重合体濃度が１ｗｔ％の紡糸原液を得た。その紡糸原液を３０℃の温度で孔径０．９９ｍｍの口金から、単孔吐出あたりの吐出量が５．７６ｍｌ／ｍｉｎになるように、空気中に押出し、３℃に温度コントロールしたメタノール溶液からなる凝固浴に導入する乾湿式紡糸法により、凝固糸条とした。曳糸性が低く、口金下での糸切れが見られ工程通過性はやや劣るが問題のないレベルであった。その凝固糸条を、メタノール中で十分洗浄した。続いて、１７０℃にコントロールしたホットチューブ中１６倍、２００℃にコントロールしたホットチューブ中５．６３倍で延伸を行った。延伸倍率は２段で９０倍である。工程通過性は良好で、全延伸倍率も９０倍と高いものであった。
[Example 7]
While stirring the dimethylformamide solution, the polyacrylonitrile polymer obtained in Example 1 was mixed and passed through a filter having an opening of 10 μm, so that a spinning stock solution having a polyacrylonitrile polymer concentration of 1 wt% in the stock solution was obtained. Obtained. The spinning dope consists of a methanol solution whose temperature is controlled at 3 ° C. by extruding the spinning stock solution into air so that the discharge amount per single hole discharge is 5.76 ml / min from a die having a hole diameter of 0.99 mm at a temperature of 30 ° C. A solidified yarn was obtained by a dry and wet spinning method introduced into a coagulation bath. The spinnability was low, thread breakage was observed under the die, and the process passability was slightly inferior, but at a level without any problem. The coagulated yarn was thoroughly washed in methanol. Subsequently, stretching was performed 16 times in a hot tube controlled at 170 ° C. and 5.63 times in a hot tube controlled at 200 ° C. The draw ratio is 90 in two stages. The process passability was good and the total draw ratio was as high as 90 times.
続いて、得られたポリアクリロニトリル系繊維を、２４０℃の空気中で耐炎化張力０．２５ｃＮ／ｄｔｅｘで８０分耐炎化処理を行ったところ、糸切れなく耐炎化繊維が得られた、耐炎化処理での工程通過性は良好であった。 Subsequently, the obtained polyacrylonitrile fiber was subjected to a flame resistance treatment in air at 240 ° C. with a flame resistance tension of 0.25 cN / dtex for 80 minutes. As a result, a flame resistant fiber was obtained without breakage. The process passability in the treatment was good.
得られた耐炎化繊維を、２００℃から４００℃に２分で昇温し、４００〜５００℃を４０秒で昇温し、最高温度７００℃で２分、延伸比１．１０で延伸しながら予備炭化処理して予備炭化糸を得た。 While the obtained flame-resistant fiber was heated from 200 ° C. to 400 ° C. in 2 minutes, the temperature was raised from 400 to 500 ° C. in 40 seconds, while being stretched at a maximum temperature of 700 ° C. for 2 minutes and a draw ratio of 1.10. Precarbonized yarn was obtained by precarbonization.
この予備炭化糸を最高温度１５００℃で３分、張力０．９ｃＮ／ｄｔｅｘの下で炭化処理することにより炭化糸を得た。炭化処理においても糸切れなく工程通過性が良好であった。 The preliminary carbonized yarn was carbonized at a maximum temperature of 1500 ° C. for 3 minutes under a tension of 0.9 cN / dtex to obtain a carbonized yarn. In the carbonization treatment, the process passability was good without yarn breakage.
[実施例８]
ジメチルホルムアミド溶液を攪拌しながら、実施例４で得られたポリアクリロニトリル系重合体を混合したが、非常に粘度が高かったため、エクストルーダーで練りこみを行うことで、原液中のポリアクリロニトリル系重合体濃度が１６ｗｔ％の紡糸原液を得た。その紡糸原液を３０℃の温度で孔径０．９９ｍｍの口金から、単孔吐出あたりの吐出量が５．７６ｍｌ／ｍｉｎになるように、空気中に押出し、３℃に温度コントロールしたメタノール溶液からなる凝固浴に導入する乾湿式紡糸法により、凝固糸条とした。その凝固糸条を、エタノール中で十分洗浄した。続いて、１７０℃にコントロールしたホットチューブ中で延伸を行った。延伸倍率は４段（４倍、２倍、２倍、１．３１倍）で２１倍であったが、延伸時に糸切れがみられ工程通過性は若干劣るものであったが問題のないレベルであった。全延伸倍率も２１倍と高いものであった。
[Example 8]
While stirring the dimethylformamide solution, the polyacrylonitrile polymer obtained in Example 4 was mixed. However, since the viscosity was very high, the polyacrylonitrile polymer in the stock solution was kneaded with an extruder. A spinning dope with a concentration of 16 wt% was obtained. The spinning dope consists of a methanol solution whose temperature is controlled at 3 ° C. by extruding the spinning stock solution into air so that the discharge amount per single hole discharge is 5.76 ml / min from a die having a hole diameter of 0.99 mm at a temperature of 30 ° C. A solidified yarn was obtained by a dry and wet spinning method introduced into a coagulation bath. The coagulated yarn was thoroughly washed in ethanol. Subsequently, stretching was performed in a hot tube controlled at 170 ° C. The draw ratio was 4 times (4 times, 2 times, 2 times, 1.31 times) and was 21 times. However, thread breakage was observed during drawing and the process passability was slightly inferior, but there was no problem. Met. The total draw ratio was as high as 21 times.
続いて、得られたポリアクリロニトリル系繊維を、２４０℃の空気中で耐炎化張力０．３ｃＮ／ｄｔｅｘで８０分耐炎化処理を行ったところ、耐炎化繊維が得られた。糸切れが若干見られたが、耐炎化処理での工程通過性は問題のないレベルであった。 Subsequently, the obtained polyacrylonitrile fiber was subjected to a flame resistance treatment in air at 240 ° C. with a flame resistance tension of 0.3 cN / dtex for 80 minutes, whereby a flame resistant fiber was obtained. Although some yarn breakage was observed, the process passability in the flameproofing treatment was at a level with no problem.
得られた耐炎化繊維を、２００℃から４００℃に２分で昇温し、４００〜５００℃を４０秒で昇温し、最高温度７００℃で２分、延伸比１．１０で延伸しながら予備炭化処理して予備炭化糸を得た。 While the obtained flame-resistant fiber was heated from 200 ° C. to 400 ° C. in 2 minutes, the temperature was raised from 400 to 500 ° C. in 40 seconds, while being stretched at a maximum temperature of 700 ° C. for 2 minutes and a draw ratio of 1.10. Precarbonized yarn was obtained by precarbonization.
この予備炭化糸を最高温度１５００℃で３分、張力１．２ｃＮ／ｄｔｅｘの下で炭化処理することにより炭化糸を得た。炭化処理においても糸切れがあったが、工程通過性は問題のないレベルであった。 The preliminary carbonized yarn was carbonized at a maximum temperature of 1500 ° C. for 3 minutes under a tension of 1.2 cN / dtex to obtain a carbonized yarn. Although there was yarn breakage in the carbonization treatment, the process passability was at a level with no problem.
[比較例１]
アクリロニトリル１００モル％をジメチルスルホキシドを溶媒し、重合開始剤としてアゾビスイソブチロニトリルを用いる溶液重合法により重合し、重合体濃度１３重量％、極限粘度３の紡糸原液を得た。
[Comparative Example 1]
100 mol% of acrylonitrile was polymerized by a solution polymerization method using dimethyl sulfoxide as a solvent and azobisisobutyronitrile as a polymerization initiator to obtain a spinning dope having a polymer concentration of 13% by weight and an intrinsic viscosity of 3.
紡糸原液は目開き１０μｍのフィルターを通過した後、３０℃の温度で孔径０．６ｍｍの口金から、単孔吐出あたりの吐出量が０．３ｍｌ／ｍｉｎになるように、空気中に押出し、３℃に温度コントロールしたジメチルスルホキシド／水＝３０／７０の溶液からなる凝固浴に導入する乾湿式紡糸法により、凝固糸条とした。この凝固糸条を、水中で十分洗浄した後、７０℃の温水中で２．４倍延伸を行った。続いて１７０℃に加熱したホットチューブを用いて延伸を行ったが、延伸倍率５倍以上は延伸できなかった。工程通過性は良好だったが、全延伸倍率は１２倍と低いものであった。 The spinning solution passes through a filter having a mesh size of 10 μm, and is then extruded into air from a die having a hole diameter of 0.6 mm at a temperature of 30 ° C. so that the discharge amount per single hole discharge is 0.3 ml / min. A coagulated yarn was obtained by a dry and wet spinning method introduced into a coagulation bath composed of a solution of dimethyl sulfoxide / water = 30/70 controlled at a temperature of 0 ° C. The coagulated yarn was thoroughly washed in water and then stretched 2.4 times in 70 ° C. warm water. Subsequently, stretching was performed using a hot tube heated to 170 ° C., but stretching was not possible at a stretching ratio of 5 times or more. The process passability was good, but the total draw ratio was as low as 12 times.
続いて、得られたポリアクリロニトリル系繊維を、２４０℃の空気中で耐炎化張力０．１１／ｄｔｅｘで８０分耐炎化処理を行ったところ、糸切れなく耐炎化繊維が得られた、耐炎化処理での工程通過性は良好であった。 Subsequently, the obtained polyacrylonitrile fiber was subjected to a flame resistance treatment in air at 240 ° C. with a flame resistance tension of 0.11 / dtex for 80 minutes. As a result, the flame resistant fiber was obtained without breakage. The process passability in the treatment was good.
得られた耐炎化繊維を、２００℃から４００℃に２分で昇温し、４００〜５００℃を４０秒で昇温し、最高温度７００℃で２分、延伸比１．１０で延伸しながら予備炭化処理して予備炭化糸を得た。 While the obtained flame-resistant fiber was heated from 200 ° C. to 400 ° C. in 2 minutes, the temperature was raised from 400 to 500 ° C. in 40 seconds, while being stretched at a maximum temperature of 700 ° C. for 2 minutes and a draw ratio of 1.10. Precarbonized yarn was obtained by precarbonization.
この予備炭化糸を最高温度１５００℃で３分、張力０．５５ｃＮ／ｄｔｅｘの下で炭化処理することにより炭化糸を得た。炭化処理において若干糸切れがあったが問題のないレベルであった。 The pre-carbonized yarn was carbonized at a maximum temperature of 1500 ° C. for 3 minutes under a tension of 0.55 cN / dtex to obtain a carbonized yarn. There was some yarn breakage in the carbonization process, but it was at a level where there was no problem.
[比較例２]
実施例１と同様に凝固糸条を得た。この凝固糸条をホットチューブで２段（４倍、３倍）で１２倍に延伸した。工程通過性は良好だったが、全延伸倍率は１２倍と低いものであった。
[Comparative Example 2]
A coagulated yarn was obtained in the same manner as in Example 1. The coagulated yarn was stretched 12 times in two stages (4 times, 3 times) with a hot tube. The process passability was good, but the total draw ratio was as low as 12 times.
続いて、得られたポリアクリロニトリル系繊維を、２４０℃の空気中で耐炎化張力０．３ｃＮ／ｄｔｅｘで８０分耐炎化処理を行ったところ、糸切れによりサンプルを得ることができなかった。耐炎化での工程通過性に問題があった。 Subsequently, when the obtained polyacrylonitrile fiber was subjected to a flame resistance treatment at a flame resistance tension of 0.3 cN / dtex for 80 minutes in air at 240 ° C., a sample could not be obtained due to yarn breakage. There was a problem in the process passage in flame resistance.
[比較例３]
実施例１と同様に得られたポリアクリロニトリル系繊維を得た。
[Comparative Example 3]
A polyacrylonitrile fiber obtained in the same manner as in Example 1 was obtained.
続いて、得られたポリアクリロニトリル系繊維を、１９０℃の空気中で耐炎化張力０．３ｃＮ／ｄｔｅｘで８０分耐炎化処理を行ったところ、若干糸切れがあったが問題のないレベルであった。 Subsequently, the obtained polyacrylonitrile fiber was subjected to a flame resistance treatment in air at 190 ° C. with a flame resistance tension of 0.3 cN / dtex for 80 minutes. It was.
得られた耐炎化繊維を、２００℃から４００℃に２分で昇温し、４００〜５００℃を４０秒で昇温し、最高温度７００℃で２分、延伸比１．１０で延伸しながら予備炭化処理して予備炭化糸を得た。 While the obtained flame-resistant fiber was heated from 200 ° C. to 400 ° C. in 2 minutes, the temperature was raised from 400 to 500 ° C. in 40 seconds, while being stretched at a maximum temperature of 700 ° C. for 2 minutes and a draw ratio of 1.10. Precarbonized yarn was obtained by precarbonization.
この予備炭化糸を最高温度１５００℃で３分、張力０．８ｃＮ／ｄｔｅｘの下で炭化処理したが、炭化処理において糸切れが見られサンプルを得ることができなかった。 This pre-carbonized yarn was carbonized at a maximum temperature of 1500 ° C. for 3 minutes under a tension of 0.8 cN / dtex. However, the carbonization treatment showed breakage of the yarn, and a sample could not be obtained.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN102400234A (en) * | 2010-09-17 | 2012-04-04 | 中国石油化工股份有限公司 | Preparation method of polyacrylonitrile-based carbon fiber precursor spinning solution |
| CN102400239A (en) * | 2010-09-17 | 2012-04-04 | 中国石油化工股份有限公司 | Method for manufacturing polyacrylonitrile-based carbon fiber precursor |
| JP2012082541A (en) * | 2010-10-08 | 2012-04-26 | Toray Ind Inc | Method for producing carbon fiber |
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| CN103710792A (en) * | 2012-10-08 | 2014-04-09 | 中国石油化工股份有限公司 | Preparation method of polyacrylonitrile-based carbon fiber |
| WO2018047692A1 (en) | 2016-09-12 | 2018-03-15 | 東レ株式会社 | Coagulated yarn and manufacturing method thereof, carbon fiber precursor fiber, and method for manufacturing carbon fiber |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN102400234A (en) * | 2010-09-17 | 2012-04-04 | 中国石油化工股份有限公司 | Preparation method of polyacrylonitrile-based carbon fiber precursor spinning solution |
| CN102400239A (en) * | 2010-09-17 | 2012-04-04 | 中国石油化工股份有限公司 | Method for manufacturing polyacrylonitrile-based carbon fiber precursor |
| JP2012082541A (en) * | 2010-10-08 | 2012-04-26 | Toray Ind Inc | Method for producing carbon fiber |
| JP2012117161A (en) * | 2010-11-29 | 2012-06-21 | Mitsubishi Rayon Co Ltd | Method for manufacturing carbon fiber bundle |
| CN103710792A (en) * | 2012-10-08 | 2014-04-09 | 中国石油化工股份有限公司 | Preparation method of polyacrylonitrile-based carbon fiber |
| WO2018047692A1 (en) | 2016-09-12 | 2018-03-15 | 東レ株式会社 | Coagulated yarn and manufacturing method thereof, carbon fiber precursor fiber, and method for manufacturing carbon fiber |
| KR20190044588A (en) | 2016-09-12 | 2019-04-30 | 도레이 카부시키가이샤 | And method for producing the same, and a method for producing carbon fiber precursor fibers and carbon fibers |
| JP2021059829A (en) * | 2019-10-09 | 2021-04-15 | 東レ株式会社 | Carbon fiber and production method of the same |
| JP7711364B2 (en) | 2019-10-09 | 2025-07-23 | 東レ株式会社 | Carbon fiber and its manufacturing method |
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