JPS62227992A - Carbon fiber, pitch for use in production of carbon fiber and production of said pitch - Google Patents
Carbon fiber, pitch for use in production of carbon fiber and production of said pitchInfo
- Publication number
- JPS62227992A JPS62227992A JP7191786A JP7191786A JPS62227992A JP S62227992 A JPS62227992 A JP S62227992A JP 7191786 A JP7191786 A JP 7191786A JP 7191786 A JP7191786 A JP 7191786A JP S62227992 A JPS62227992 A JP S62227992A
- Authority
- JP
- Japan
- Prior art keywords
- pitch
- carbon fiber
- acid
- components
- spinning
- 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.)
- Pending
Links
- 229920000049 Carbon (fiber) Polymers 0.000 title claims abstract description 41
- 239000004917 carbon fiber Substances 0.000 title claims abstract description 41
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 12
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 title abstract description 18
- 239000011295 pitch Substances 0.000 claims abstract description 63
- 239000002253 acid Substances 0.000 claims abstract description 9
- 239000003960 organic solvent Substances 0.000 claims abstract description 7
- 239000006185 dispersion Substances 0.000 claims abstract description 4
- 230000002378 acidificating effect Effects 0.000 claims description 16
- 239000011304 carbon pitch Substances 0.000 claims 1
- 238000010438 heat treatment Methods 0.000 abstract description 29
- 238000009987 spinning Methods 0.000 abstract description 13
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 abstract description 9
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 abstract description 9
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 abstract description 8
- 239000011300 coal pitch Substances 0.000 abstract description 6
- 238000005087 graphitization Methods 0.000 abstract description 4
- 239000002904 solvent Substances 0.000 abstract description 2
- JUJWROOIHBZHMG-UHFFFAOYSA-N Pyridine Chemical compound C1=CC=NC=C1 JUJWROOIHBZHMG-UHFFFAOYSA-N 0.000 abstract 2
- 208000012886 Vertigo Diseases 0.000 abstract 2
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 abstract 1
- UMJSCPRVCHMLSP-UHFFFAOYSA-N pyridine Natural products COC1=CC=CN=C1 UMJSCPRVCHMLSP-UHFFFAOYSA-N 0.000 abstract 1
- 235000011149 sulphuric acid Nutrition 0.000 abstract 1
- 238000000034 method Methods 0.000 description 18
- 239000000126 substance Substances 0.000 description 14
- 238000002074 melt spinning Methods 0.000 description 12
- 239000002994 raw material Substances 0.000 description 10
- 230000000704 physical effect Effects 0.000 description 9
- 239000000835 fiber Substances 0.000 description 8
- 230000007935 neutral effect Effects 0.000 description 6
- 229920002239 polyacrylonitrile Polymers 0.000 description 6
- 238000012545 processing Methods 0.000 description 5
- 238000006068 polycondensation reaction Methods 0.000 description 4
- YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 description 3
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- 239000007864 aqueous solution Substances 0.000 description 3
- 238000000354 decomposition reaction Methods 0.000 description 3
- 239000011301 petroleum pitch Substances 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 2
- 150000007513 acids Chemical class 0.000 description 2
- 238000003763 carbonization Methods 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- UOCLXMDMGBRAIB-UHFFFAOYSA-N 1,1,1-trichloroethane Chemical compound CC(Cl)(Cl)Cl UOCLXMDMGBRAIB-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 241000252233 Cyprinus carpio Species 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 1
- 239000000920 calcium hydroxide Substances 0.000 description 1
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- -1 dimethyl sulfoxide Chemical compound 0.000 description 1
- 238000004821 distillation Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 150000002366 halogen compounds Chemical class 0.000 description 1
- 150000004678 hydrides Chemical class 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002715 modification method Methods 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 150000002989 phenols Chemical class 0.000 description 1
- 239000011312 pitch solution Substances 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 150000003222 pyridines Chemical class 0.000 description 1
- 238000002407 reforming Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000001568 sexual effect Effects 0.000 description 1
- 229910052938 sodium sulfate Inorganic materials 0.000 description 1
- 235000011152 sodium sulphate Nutrition 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Landscapes
- Working-Up Tar And Pitch (AREA)
- Inorganic Fibers (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は優れた物性を有する炭素繊維及び優れた溶融紡
糸性を有する炭素繊維製造用ピッチ、並びに当該ピッチ
を製造する方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a carbon fiber having excellent physical properties, a pitch for producing carbon fiber having excellent melt spinnability, and a method for producing the pitch.
「従来の技術］
炭素質ピッチを原料とするいわゆるピッチ系炭素繊維は
、ポリアクリロニトリル繊維を原料とするＰＡＮ系炭素
炭素繊維べて原料コストが安価である反面、性能面にや
や問題がある。その為当該原料の選定や前処理、更には
焼成・炭化方法等について色々改良研究が進められてい
る。殊に原料ピッチの化学的性状や物性等によって製品
炭素繊維の特性は著しい影響を受けるから、石炭ピッチ
や石油ピッチの選択基準を定めたり或は改質する方法が
集中的に検討されている。例えば特開昭４８−３６１７
０号公報には粘度による選択基準が、また特開昭５３−
６０６７５号公報や同５５−１６２９７２号公報には溶
剤分別成分量による選択基準が、更に特開昭５８−７６
５２３号公報には反射率による選択基準が夫々開示され
ている。しかしながらこれら物理的性質を選択基準とす
る方式は原料ピッチそのものの物性を特定し得るとして
も熱処理や炭素化等によって該特性がどの様な影響を受
けるかにっては予期し得ない点が多く、そのため炭素繊
維用原料としての適性を正確に予知することはできない
。一方原料ピッチを化学的性質という面から改質する技
術として脱アスフアルテン化法（特開昭５８−４７０８
９号公報等）、水素化物を添加する方法（特開昭５８−
８７１８７号公報、同５８−１４４１２６号公報、同５
８−１９６２９２号公報等）、ワックスを添加する方法
（特開昭５８−７１９９０号公報等）なども試みられて
いる。しかしながらこれらの改質法で得たピッチは、常
に最良の炭素繊維を与えるという保証がなく、ＰＡＮ系
原料の場合に比べると物理的及び化学的特性が不安定で
ある。"Prior Art" So-called pitch-based carbon fibers made from carbonaceous pitch, as well as PAN-based carbon fibers made from polyacrylonitrile fibers, have low raw material costs, but have some problems in terms of performance. Therefore, various improvement studies are being carried out on the selection and pretreatment of the raw materials, as well as the firing and carbonization methods.In particular, the characteristics of the product carbon fiber are significantly affected by the chemical properties and physical properties of the raw material pitch. Methods for establishing selection criteria and reforming coal pitch and petroleum pitch have been intensively studied.For example, Japanese Patent Application Laid-Open No. 48-3617
Publication No. 0 includes selection criteria based on viscosity, and JP-A-53-
No. 60675 and No. 55-162972 have selection criteria based on the amount of fractionated components of the solvent, and JP-A No. 58-76
Publication No. 523 discloses selection criteria based on reflectance. However, even if these methods that use physical properties as selection criteria can identify the physical properties of the raw material pitch itself, there are many points in which it is impossible to predict how these properties will be affected by heat treatment, carbonization, etc. Therefore, its suitability as a raw material for carbon fiber cannot be accurately predicted. On the other hand, as a technology for modifying raw material pitch from the viewpoint of chemical properties, the asphaltenization method (Japanese Unexamined Patent Publication No. 58-4708
9, etc.), method of adding hydride (Japanese Patent Application Laid-Open No. 1983-
No. 87187, No. 58-144126, No. 5
8-196292, etc.), and a method of adding wax (Japanese Patent Application Laid-Open No. 58-71990, etc.) have also been attempted. However, there is no guarantee that the pitch obtained by these modification methods will always give the best carbon fiber, and its physical and chemical properties are unstable compared to the case of PAN-based raw materials.
その為ピッチ系炭素繊維は、ＰＡＮ系炭素炭素繊維べる
と品質安定性が乏しく且つ強度や弾性率等も満足し得る
域に至っていない。Therefore, pitch-based carbon fibers have poorer quality stability than PAN-based carbon fibers, and their strength, elastic modulus, etc. have not yet reached a satisfactory level.
ところでピッチ系炭素繊維の製法として現在汎用されて
いるのは、石炭ピッチや石油ピッチからなる炭素質ピッ
チ類を熱処理してメソフェーズを含む紡糸用ピッチとし
、これを溶融紡糸した後不融化及び炭素化し、必要によ
っては更に黒鉛化する方法である。即ちピッチを、分子
配向を有するメソフェーズに変化させてから紡糸するこ
とによって、繊維軸方向に分子配向させたピッチ繊維を
得、これを更に熱処理することにより高性能の炭素繊維
を得ようとするものである。By the way, the currently widely used method for producing pitch-based carbon fibers is to heat-treat carbonaceous pitches such as coal pitch and petroleum pitch to produce spinning pitch containing mesophase, which is then melt-spun and then made infusible and carbonized. , if necessary, further graphitization is performed. In other words, pitch is transformed into a mesophase with molecular orientation and then spun to obtain pitch fibers with molecular orientation in the fiber axis direction, which is then further heat treated to obtain high performance carbon fibers. It is.
［発明が解決しようとする問題点］
ところが従来の炭素質ピッチでは、メソフェーズを含む
紡糸可能なピッチを生成しようとすれば熱処理条件を極
めて厳格に設定しなければならず、しかも紡糸工程にお
ける操作可能な条件範囲も極めて狭く条件設定が非常に
困難であり、こうした問題がピッチ系高性能炭素繊維の
汎用化を妨げる大きな原因となっている。[Problems to be Solved by the Invention] However, with conventional carbonaceous pitch, in order to produce spinnable pitch containing mesophase, heat treatment conditions must be set extremely strictly, and furthermore, it is difficult to manipulate the process during the spinning process. The range of conditions is extremely narrow and setting the conditions is extremely difficult, and these problems are a major cause of hindering the general use of pitch-based high-performance carbon fibers.
本発明はこの様な事情に着目してなされたものであって
、その目的は、ピッチ系高性能炭素！ａ維を製造する上
で隘路となっている熱処理条件や紡糸条件の設定におけ
る困難性を解消し、ＰＡＮ系炭素炭素繊維べても遜色の
ない且つ安定した性能のピッチ系炭素繊維を容易に製造
し得る様な炭素繊維製造用ピッチ及びその製造方法、並
びに高性能のピッチ系炭素繊維を提供しようとするもの
である。The present invention was made with attention to these circumstances, and its purpose is to produce pitch-based high-performance carbon! Eliminates the difficulty in setting heat treatment conditions and spinning conditions, which are bottlenecks in producing a-fibers, and easily produces pitch-based carbon fibers that are comparable to PAN-based carbon fibers and have stable performance. The purpose of this invention is to provide a pitch for producing carbon fibers, a method for producing the same, and a high-performance pitch-based carbon fiber.
［問題点を解決する為の手段］
上記の目的を達成することのできた本発明炭素繊維及び
炭素繊維製造用ピッチの構成は、酸性成分及び塩基性成
分を実質的に含まず、実質的に中性成分のみから構成さ
れるところに要旨を有するものである。また本発明に係
る製造方法の構成は、炭素質ピッチを有機溶剤に分散す
ると共に該分散液を塩基及び／若しくは酸で処理して酸
性成分及び／若しくは塩基性成分を除去する工程を含む
ところに要旨を有するものである。[Means for Solving the Problems] The composition of the carbon fiber and the pitch for producing carbon fiber of the present invention, which can achieve the above object, is that it contains substantially no acidic component or basic component, and contains substantially no acidic component or basic component. The gist is that it is composed only of sexual components. Further, the structure of the production method according to the present invention includes a step of dispersing carbonaceous pitch in an organic solvent and treating the dispersion with a base and/or acid to remove acidic components and/or basic components. It has a gist.
［作用］
本発明を実施するに当たって使用される炭素質ピッチと
しては、石炭系ピッチ及び石油系ピッチの双方を挙げる
ことができ、これらのピッチは通常３５０℃以上で加熱
すると光学的異方性をもったメソフェーズを生成する。[Function] The carbonaceous pitch used in carrying out the present invention includes both coal-based pitch and petroleum-based pitch, and these pitches normally exhibit optical anisotropy when heated at 350°C or higher. Generates a mesophase.
これを更に加熱すると該メソフェーズが徐々に成長・合
体し、「流れ構造」と称される組織へと発達していく。When this is further heated, the mesophase gradually grows and coalesces, developing into a structure called a "flow structure."
ここで高性能炭素繊維を与えるピッチとする為には、当
該熱処理ピッチ中のメソフェーズ含有量が約６５％以上
、好ましくは８５％以上となる様に、熱処理温度や熱処
理時間、圧力（加圧度又は減圧度）を選定すべきである
とされている。Here, in order to obtain a pitch that provides high-performance carbon fiber, the heat treatment temperature, heat treatment time, pressure (pressure degree or the degree of reduced pressure) should be selected.
一方、通常の炭素質ピッチを加熱してメソフェーズが６
５％以上となるまで処理すると、軟化点の高いいわゆる
固いメゾフェーズが生成し溶融紡糸が困難になる。そこ
でこうした現象が生ずる理由を明確にしようとして色々
研究を進めるうち、次の様な事実が明らかとなってきた
。即ち熱処理の初期段階では、ピッチ構成４分のうち分
解し易い成分が熱分解し、引続き重・縮合反応を起こし
て高分子量物質が生成するが、この高分子量物質は低分
子量物買よりも高密度であり、また溶融紡糸温度におけ
る溶解度（液状である成分に対する溶解度）も低いので
、紡糸条件下でもこれらの高分子量物質が固形物のまま
で残存し紡糸性を阻害しているものと考えられる。On the other hand, when ordinary carbonaceous pitch is heated, the mesophase becomes 6
When processed to a concentration of 5% or more, a so-called hard mesophase with a high softening point is generated, making melt spinning difficult. As we proceeded with various studies to clarify the reasons why this phenomenon occurs, the following facts became clear. That is, at the initial stage of heat treatment, the components that are easily decomposed in the pitch composition are thermally decomposed, and then polycondensation reactions occur to produce high molecular weight substances, but these high molecular weight substances have higher molecular weight than low molecular weight substances. Since the density and solubility (solubility for liquid components) at the melt spinning temperature are also low, it is thought that these high molecular weight substances remain as solids even under spinning conditions and inhibit spinnability. .
この様なところから従来は、高分子量物質の生成を極力
抑制しつつメソフェーズを６５％以上となし得る様に熱
処理条件を定めていたものと考えられるが、その様な熱
処理条件は非常に狭く且つ原料ピッチの種類や品番等に
よフても微妙に変わってくる為、制御が極めて困難であ
る。また熱処理段階で条件を適正にコントロールし得た
としても、当該紡糸用ピッチは紡糸装置内で分解・重縮
合反応を起こして不溶物を生成することも多く、紡糸条
件の許容範囲も非常に狭い。From this point of view, it is thought that in the past, heat treatment conditions were set so as to achieve a mesophase content of 65% or more while suppressing the production of high molecular weight substances as much as possible, but such heat treatment conditions were very narrow and It is extremely difficult to control because it varies slightly depending on the type of raw material pitch, product number, etc. Furthermore, even if the conditions can be properly controlled during the heat treatment step, the spinning pitch often undergoes decomposition and polycondensation reactions in the spinning equipment, producing insoluble matter, and the tolerance range for spinning conditions is very narrow. .
そこで上記の様な問題点を生じる原因と考えられる「熱
処理の初期過程で分解し易い成分」を予め除去しておけ
ば、上記の問題をことごとく解消することができるであ
ろうとの方針を立て、研究を進めた。その結果、当該「
分解し易い成分」の大部分は酸性成分及び塩基性成分で
あり、これらを熱処理前の予備処理工程で除去すること
ができれば本発明の目的を達成し得るとの確信が得られ
た。Therefore, we established a policy that all of the above problems could be solved by removing in advance "components that are easily decomposed during the initial process of heat treatment," which is thought to be the cause of the above problems. I proceeded with my research. As a result, the said “
Most of the "components that are easily decomposed" are acidic components and basic components, and it was confirmed that the object of the present invention could be achieved if these components could be removed in a pretreatment step before heat treatment.
本発明に係る炭素繊維製造用ピッチはこの様な知見に基
づいて提案されるものであって、酸性成分及び塩基性成
分を実質的に含まず、実質的に中性成分のみからなる炭
素質ピッチである。このピッチは熱処理工程で超高分子
の不溶・不融物を生成することがないので熱処理条件の
許容範囲が広く、且つ熱処理によって融点が過度に上昇
することなしに所望量のメソフェーズを生成させること
ができる。しかもこのピッチを溶融紡糸する時の熱によ
って不融物を生成することもないので溶融紡糸条件の許
容範囲も広く、且つ得られる炭素繊維の物性も非常に良
好で品質の安定したものとなる。The pitch for producing carbon fibers according to the present invention is proposed based on such knowledge, and is a carbonaceous pitch that does not substantially contain acidic components or basic components and consists essentially only of neutral components. It is. This pitch does not generate insoluble or infusible ultra-high polymers during the heat treatment process, so it has a wide range of tolerance for heat treatment conditions, and it is possible to generate the desired amount of mesophase without excessively increasing the melting point during heat treatment. I can do it. Furthermore, since no infusible substances are generated due to the heat generated when this pitch is melt-spun, the allowable range of melt-spinning conditions is wide, and the physical properties of the resulting carbon fibers are also very good and of stable quality.
上記からも明らかな様に、本発明炭素繊維製造用ピッチ
は、「酸性成分及び塩基性成分を含まず実質的に中性成
分のみからなるもの」として特定することができるが、
この他物性面からみた場合、例えば■軟化点、■特定有
機溶剤への可溶性成分量、或は■熱処理後における不溶
（対特定有機溶剤）性成分合有量等によって特定するこ
とができる。As is clear from the above, the pitch for producing carbon fibers of the present invention can be specified as "consisting essentially only of neutral components without containing acidic components or basic components."
In terms of other physical properties, it can be specified, for example, by (1) softening point, (2) the amount of soluble components in a specific organic solvent, or (2) the amount of insoluble (in specific organic solvent) components after heat treatment.
尚、原料ピッチ中の酸性成分及び塩基性成分を除去する
方法は種々挙げられるが、最も好ましい方法としては、
原料ピッチをクロロホルム、塩化メチレン、トリクロル
エタン等のハロゲン化合物やジメチルスルホキシド等の
有機溶剤に溶解乃至分散し、これに塩基（水酸化ナトリ
ウム、水酸化カリウム、水酸化カルシウム、アンモニア
等の水溶液など）を加えて酸性成分（殊にフェノール系
化合物など）を抽出除去し、また酸（硫酸、塩酸、硝酸
等の水溶液など）を加えて塩基性成分（殊にピリジン系
化合物など）を抽出除去する方法である。本発明では酸
性成分及び塩基性成分の双方を上記方法によって除去し
、ピッチ成分を実質的に中性成分のみとするのが最善で
あるが、この他酸性成分及び塩基性成分の一方のみを除
去した場合であっても、熱処理時に生じる高分子量物の
量は原料ピッチに比べると極端に少なくなり、本発明の
目的を十分に果たすことができる。There are various methods for removing the acidic components and basic components in the raw pitch, but the most preferred method is:
The raw material pitch is dissolved or dispersed in a halogen compound such as chloroform, methylene chloride, trichloroethane, or an organic solvent such as dimethyl sulfoxide, and a base (aqueous solution of sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonia, etc.) is added to this. In addition, acidic components (especially phenolic compounds, etc.) are extracted and removed, and acids (such as aqueous solutions of sulfuric acid, hydrochloric acid, nitric acid, etc.) are added to extract and remove basic components (especially pyridine compounds, etc.). be. In the present invention, it is best to remove both the acidic component and the basic component by the above method so that the pitch component is substantially only a neutral component, but in addition, only one of the acidic component and the basic component is removed. Even in this case, the amount of high molecular weight substances generated during heat treatment is extremely small compared to the raw material pitch, and the purpose of the present invention can be fully achieved.
上記の様にして酸性成分及び塩基性成分を除去した後は
、水洗等によって酸や塩基を除去し次いで減圧蒸留等に
付して有機溶剤を除去すれば、良質の炭素繊維用ピッチ
を得ることができる。このピッチは３５０〜５００℃、
好ましくは４３０〜４９０℃程度の温度で熱処理するこ
とによって、炭素繊維の物性を支配するメソフェーズを
６５％以上含む紡糸用ピッチとなる。この紡糸用ピッチ
は、メソフェーズを６５％以上含んでいるにもかかわら
ず軟化点は２５０〜３５０℃程度の比較的低温に抑えら
れており、紡糸性も極めて良好である。これは、熱処理
の初期過程で分解する成分が予め除去されている為ピッ
チ成分の極端な高分子化が抑制され、また熱処理後の紡
糸ピッチ中に、糸切れやノズル閉塞の原因となる超高分
子量の難溶・難融成分が含まれなくなった為と考えられ
る。After removing acidic and basic components as described above, if the acids and bases are removed by washing with water and then the organic solvent is removed by distillation under reduced pressure, high quality pitch for carbon fibers can be obtained. I can do it. This pitch is 350~500℃,
By heat-treating preferably at a temperature of about 430 to 490° C., a spinning pitch containing 65% or more of mesophase, which controls the physical properties of carbon fibers, is obtained. Although this spinning pitch contains 65% or more of mesophase, its softening point is suppressed to a relatively low temperature of about 250 to 350°C, and its spinnability is also extremely good. This is because the components that decompose in the initial process of heat treatment are removed in advance, so the extreme polymerization of the pitch components is suppressed. This is thought to be due to the fact that it no longer contains components with low molecular weight that are difficult to dissolve or melt.
しかもこの様にして得たピッチ繊維の性状を偏光顕微鏡
で観察すると、繊維軸方向に配向した分子の存在を確認
することができ、この分子配向は、その後に行なわれる
不融化処理及びそれに続く炭素化処理（９００〜１５０
０℃程度）工程でも乱れることがなく、炭素繊維の性能
（強度及び弾性率）を高める為の重要な要素となる。尚
必要であれば更に２０００〜３０００℃程度に加熱して
黒鉛化することにより、強度及び弾性率を一段と高める
ことができる。Moreover, when the properties of the pitch fibers obtained in this way are observed with a polarizing microscope, it is possible to confirm the presence of molecules oriented in the direction of the fiber axis, and this molecular orientation is caused by the subsequent infusibility treatment and the subsequent carbon fibers. processing (900-150
It is not disturbed even during the process (around 0°C) and is an important element for improving the performance (strength and elastic modulus) of carbon fibers. If necessary, the strength and elastic modulus can be further increased by further heating to about 2,000 to 3,000° C. to graphitize.
以上の様に本発明の炭素繊維製造用ピッチは実質的に中
性成分のみからなるものであり、熱処理の初期工程で分
解及び重・縮合を殆んど生ずることがないので、メソフ
ェーズ生成の為の熱処理条件を比較的広い範囲に設定す
ることができ、熱処理操業を比較的容易に遂行し得るば
かりでなく熱処理物の品質安定性も向上し、更に°はメ
ソフェーズの生成率自体も従来例より高めることができ
る。しかも熱処理物中には不溶・不融性の超高分子量物
質が殆んど存在せず、溶融紡糸工程でノズル閉塞や糸切
れ等の問題を生ずることがないので、優れた溶融紡糸性
が発揮され、その結果高レベルの強度及び弾性率を有す
るピッチ系繊維を得ることができる。As described above, the pitch for producing carbon fibers of the present invention consists essentially only of neutral components, and almost no decomposition or polycondensation occurs in the initial step of heat treatment, so it is difficult to generate mesophase. The heat treatment conditions can be set over a relatively wide range, and the heat treatment operation is not only relatively easy to perform, but also the quality stability of the heat treated product is improved, and the mesophase production rate itself is also higher than in conventional methods. can be increased. Moreover, there are almost no insoluble or infusible ultra-high molecular weight substances in the heat-treated material, and problems such as nozzle clogging or yarn breakage do not occur during the melt spinning process, so excellent melt spinning properties are exhibited. As a result, pitch-based fibers with high levels of strength and modulus can be obtained.
［実施例］
比較例
石炭系ピッチを単味で、窒素気流下常圧または減圧（１
〜５０ ｍｍＨｇ）雰囲気中、３５０〜５００℃、０〜
１８０分の熱処理（第１表）に付し、得第 １
表
＊処理時間０分とは、所定温度にまで昇温した後直ちに
降温した場合を示す。[Example] Comparative example Coal-based pitch alone was heated under normal pressure or reduced pressure (1
~50 mmHg) atmosphere, 350~500℃, 0~
After heat treatment for 180 minutes (Table 1),
Table *Processing time 0 minutes indicates the case where the temperature was raised to a predetermined temperature and then immediately lowered.
その結果、Ｎｏ、 ５で得たものを除き４００を以上の
軟化点を示す超高分子量物質が多量存在している為、溶
融紡糸が極めて困難であった。またＮｏ、 ５で得た熱
処理物の場合、４００を以上の軟化点を示す超高分子量
物質は殆んど存在しなかったが、溶融紡糸工程で糸切れ
が頻発する他ノズルの閉塞もしばしば発生し、連続紡糸
が困難であった。これは、溶融紡糸時の熱で高軟化点の
超高分子量物質が生成したことによるものと考えられる
。As a result, melt spinning was extremely difficult since a large amount of ultra-high molecular weight substances having a softening point of 400 or higher were present except for those obtained in No. 5. In addition, in the case of the heat-treated products obtained in No. 5, there was almost no ultra-high molecular weight material with a softening point of 400 or higher, but yarn breakage and nozzle clogging occurred frequently during the melt spinning process. However, continuous spinning was difficult. This is thought to be due to the generation of an ultra-high molecular weight substance with a high softening point due to the heat during melt spinning.
夫鳳週
比較例で用いたのと同じ石炭系ピッチを１０倍容量のク
ロロホルムに溶解し、このピッチ溶液を同容量の３Ｎ−
水酸化ナトリウム水溶液で抽出（３回）し、酸性成分を
除去した。The same coal-based pitch used in the Comparative Example was dissolved in 10 times the volume of chloroform, and this pitch solution was dissolved in the same volume of 3N-
Extraction was performed with an aqueous sodium hydroxide solution (three times) to remove acidic components.
その後同容量の３Ｎ−硫酸水溶液を用いて塩基性成分を
抽出（３回）し、更に水洗して硫酸を除去した。次いで
無水硫酸ナトリウムを加えて乾燥した後詰硫酸ナトリウ
ムを濾去し、クロロホルムを減圧留去し、実質的に中性
成分のみからなる炭素繊維製造用ピッチを得た。Thereafter, basic components were extracted (three times) using the same volume of 3N sulfuric acid aqueous solution, and the sulfuric acid was further washed with water to remove the sulfuric acid. Next, anhydrous sodium sulfate was added and the dried after-filling sodium sulfate was filtered off, and chloroform was distilled off under reduced pressure to obtain a pitch for producing carbon fibers consisting essentially only of neutral components.
得られたピッチを窒素気流下常圧または減圧（１〜５０
１！ｌＬｎＨｇ）雰囲気中、３５０〜５００℃、０〜１
８０分の熱処理（第２表）に付し、得られた各熱処理物
の溶融紡糸性を調べた。The obtained pitch was heated under a nitrogen stream at normal pressure or reduced pressure (1 to 50
1! lLnHg) atmosphere, 350-500℃, 0-1
The resulting heat treated products were subjected to a heat treatment for 80 minutes (Table 2) and their melt spinnability was examined.
第 ２ 表
上記で得た各熱処理物はいずれも加熱により均一ニａ融
ｔ、、スムーズに連続紡糸することができた。Table 2 The heat-treated products obtained above were all uniformly melted by heating and could be smoothly and continuously spun.
一例として、４７０℃で１０分間熱処理した紡糸用ピッ
チ（Ｎｏ、１２）について行なった溶融紡糸、不融化処
理及び黒鉛化処理の各条件並びに得られた炭素繊維の物
性を以下に示す。As an example, the conditions of melt spinning, infusibility treatment, and graphitization treatment performed on spinning pitch (No. 12) heat-treated at 470° C. for 10 minutes and the physical properties of the obtained carbon fiber are shown below.
（溶融紡糸条件）
温度 ＝３５０℃
ノズル径 ： ０．５ ｍｍφ
巻取速度 ：１０００ｍ／分
（不融化処理条件）
空気中にて１℃／分の加熱速度で３００ｔまで昇温
（黒鉛化処理条件）
昇温速度 ＝１０℃／分
処理温度 ： ２８５０℃
処理時間 二〇分（処理温度まで昇温後直ちに降温）
（Ｉｆ；＊ ｔｕｂ 鮒（７’ｌ ＆４ｎ ４’ｋ ）
繊維径 ：１０μｍ
引張強度 ： ３１６ Ｋｇ／ ｍｍ２引張弾性率：４
６トン／ｍｍ”
一般のＰＡＮ系炭素炭素繊維張強度は２５０〜３５０
Ｋｇ／ ｍｍ’ 、引張弾性率は２０〜４０トン／ｍｍ
２であるが、本発明のピッチ系炭素繊維はこれらに比べ
ても何ら遜色のない機械的特性を有していることがわか
る。(Melt spinning conditions) Temperature = 350°C Nozzle diameter: 0.5 mmφ Winding speed: 1000 m/min (infusibility treatment conditions) Temperature raised to 300t at a heating rate of 1°C/min in air (graphitization treatment conditions) ) Temperature increase rate = 10℃/min Processing temperature: 2850℃ Processing time 20 minutes (temperature is lowered immediately after heating up to processing temperature) (If; * tub Carp (7'l & 4n 4'k)
Fiber diameter: 10μm Tensile strength: 316 Kg/mm2 Tensile modulus: 4
6 tons/mm” General PAN carbon fiber tensile strength is 250 to 350
Kg/mm', tensile modulus is 20-40 tons/mm
2, it can be seen that the pitch-based carbon fiber of the present invention has mechanical properties that are comparable to these.
［発明の効果］
本発明は以上の様に構成されており、その効果を要約す
ると次の通りである。[Effects of the Invention] The present invention is configured as described above, and its effects are summarized as follows.
（１）本発明の炭素繊維製造用ピッチは酸性成分及び塩
基性成分を実質的に含まず、実質的に中性成分のみから
なるものであって、メソフェーズ生成の為の熱処理工程
或は溶融紡糸工程で分解及び重・縮合反応を起こして超
高分子量化することがないので、熱処理が容易であるば
かりでなく溶融紡糸性も非常に優れている。(1) The pitch for producing carbon fibers of the present invention does not substantially contain acidic components or basic components, and consists essentially only of neutral components, and is subject to a heat treatment process or melt spinning for mesophase generation. Since it does not undergo decomposition or polycondensation reactions during the process to form an ultra-high molecular weight, it is not only easy to heat-treat, but also has excellent melt-spinning properties.
（２）熱処理工程で不溶不融物を生成することがないの
で必要十分量のメソフェーズを生成させることができ、
炭素繊維の物性を最大限に高めることができる。(2) Since no insoluble matter is produced in the heat treatment process, a necessary and sufficient amount of mesophase can be produced;
The physical properties of carbon fiber can be maximized.
（３）本発明の方法を採用すれば、熱処理工程で不溶・
不融物を生成する原因となる酸性成分及び／又は塩基性
成分を容易に除去することができ、どの様な炭素質ピッ
チからでも高品質の炭素繊維製造用ピッチを確実に製造
することができる。(3) If the method of the present invention is adopted, insoluble and
Acidic components and/or basic components that cause the formation of infusible substances can be easily removed, and high-quality pitch for carbon fiber manufacturing can be reliably produced from any carbonaceous pitch. .
Claims (2)
であることを特徴とする炭素繊維及び炭素繊維製造用ピ
ッチ。(1) Carbon fibers and pitch for producing carbon fibers, characterized in that they are substantially free of acidic components and basic components.
液を塩基及び／若しくは酸で処理して酸性成分及び／若
しくは塩基性成分を除去する工程を含むことを特徴とす
る炭素繊維製造用ピッチの製造方法。(2) A pitch for producing carbon fibers, which includes a step of dispersing carbonaceous pitch in an organic solvent and treating the dispersion with a base and/or acid to remove acidic components and/or basic components. manufacturing method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7191786A JPS62227992A (en) | 1986-03-29 | 1986-03-29 | Carbon fiber, pitch for use in production of carbon fiber and production of said pitch |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7191786A JPS62227992A (en) | 1986-03-29 | 1986-03-29 | Carbon fiber, pitch for use in production of carbon fiber and production of said pitch |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS62227992A true JPS62227992A (en) | 1987-10-06 |
Family
ID=13474365
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7191786A Pending JPS62227992A (en) | 1986-03-29 | 1986-03-29 | Carbon fiber, pitch for use in production of carbon fiber and production of said pitch |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62227992A (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60208394A (en) * | 1984-03-31 | 1985-10-19 | Nippon Steel Corp | Preparation of mesophase pitch for carbon product |
-
1986
- 1986-03-29 JP JP7191786A patent/JPS62227992A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60208394A (en) * | 1984-03-31 | 1985-10-19 | Nippon Steel Corp | Preparation of mesophase pitch for carbon product |
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