JP2010185163A - Production method of precursor fiber for obtaining carbon fiber having high strength and high elastic modulus - Google Patents
Production method of precursor fiber for obtaining carbon fiber having high strength and high elastic modulus Download PDFInfo
- Publication number
- JP2010185163A JP2010185163A JP2010005744A JP2010005744A JP2010185163A JP 2010185163 A JP2010185163 A JP 2010185163A JP 2010005744 A JP2010005744 A JP 2010005744A JP 2010005744 A JP2010005744 A JP 2010005744A JP 2010185163 A JP2010185163 A JP 2010185163A
- Authority
- JP
- Japan
- Prior art keywords
- carbon
- fiber
- polyacrylonitrile
- based polymer
- carbon fiber
- 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.)
- Granted
Links
Abstract
Description
本発明は、高強度かつ高弾性率の炭素繊維を得るための前駆体繊維の製造方法に関する。また、本発明は、かかる製造方法によって得られる前駆体繊維、及びかかる前駆体繊維から得られる高強度かつ高弾性率の炭素繊維に関する。さらに、本発明は、かかる前駆体繊維の製造に使用する紡糸原液に関する。 The present invention relates to a method for producing precursor fibers for obtaining carbon fibers having high strength and high elastic modulus. The present invention also relates to a precursor fiber obtained by such a production method and a high-strength and high-modulus carbon fiber obtained from such a precursor fiber. Furthermore, the present invention relates to a spinning dope used for the production of such precursor fibers.
炭素繊維は、軽量かつ高強度、高弾性率という極めて優れた物性を有することから、釣竿、ゴルフクラブやスキー板等の運動用具からＣＮＧタンク、フライホイール、風力発電用風車、タービンブレード等の形成材料、道路、橋脚等の構造物の補強材、さらには、航空機、宇宙用素材として使われ、さらにその用途は広がりつつある。 Carbon fiber has extremely excellent physical properties such as light weight, high strength, and high elastic modulus, so it can be used to form CNG tanks, flywheels, wind turbines, turbine blades, etc., from fishing equipment such as fishing rods, golf clubs and skis. It is used as a reinforcing material for structures such as materials, roads and piers, as well as aircraft and space materials, and its uses are expanding.
このような炭素繊維の用途の拡大につれて、より高強度、高弾性率を有する炭素繊維の開発が望まれるようになってきている。 As the use of such carbon fibers expands, development of carbon fibers having higher strength and higher elastic modulus has been desired.
炭素繊維は、ポリアクリロニトリルを原料とするＰＡＮ系炭素繊維と、石炭由来のコールタール、石油由来のデカントオイルやエチレンボトムなどを出発原料とするピッチ系炭素繊維に大別される。いずれの炭素繊維も、まずこれらの原料から前駆体繊維を製造し、この前駆体繊維を高温で加熱して耐炎化、予備炭素化、及び炭素化することによって製造される。 Carbon fibers are roughly classified into PAN-based carbon fibers made from polyacrylonitrile and pitch-based carbon fibers made from coal-derived coal tar, petroleum-derived decant oil, ethylene bottom, and the like. Any carbon fiber is produced by first producing a precursor fiber from these raw materials and heating the precursor fiber at a high temperature to make it flame resistant, pre-carbonized, and carbonized.
物性の点から見ると、現在市販されているＰＡＮ系炭素繊維は、最大６ＧＰａ程度という極めて高い引張強度を達成することができるが、引張弾性率が発現しにくく、最大でも３００ＧＰａ程度に留まっている。一方、現在市販されているピッチ系炭素繊維は、最大８００ＧＰａ程度という極めて高い引張弾性率を達成することができるが、引張強度が発現しにくく、最大でも３ＧＰａ程度に留まっている。航空機や宇宙用素材として使用するためには、高引張強度かつ高引張弾性率の炭素繊維が望ましいが、このように、現在提案されている炭素繊維の中にこの要件を満たすものは存在しない。 From the viewpoint of physical properties, currently available PAN-based carbon fibers can achieve a very high tensile strength of about 6 GPa at the maximum, but it is difficult to develop a tensile elastic modulus and remains at a maximum of about 300 GPa. . On the other hand, pitch-based carbon fibers that are currently available on the market can achieve a very high tensile elastic modulus of about 800 GPa at the maximum, but the tensile strength is difficult to develop and remains at about 3 GPa at the maximum. For use as an aircraft or space material, a carbon fiber having a high tensile strength and a high tensile modulus is desirable, but there is no carbon fiber currently proposed that satisfies this requirement.
一方、特許文献１には、ポリアクリロニトリル系ポリマーにカーボンナノチューブを添加して紡糸することによって得られた前駆体繊維（カーボンナノチューブ含有ＰＡＮ系前駆体繊維）が、従来のＰＡＮ系前駆体繊維より高い引張弾性率を示すことが開示されている。 On the other hand, in Patent Document 1, precursor fibers (carbon nanotube-containing PAN precursor fibers) obtained by adding carbon nanotubes to a polyacrylonitrile-based polymer and spinning them are higher than conventional PAN-based precursor fibers. It is disclosed to exhibit a tensile modulus.
しかし、特許文献１の方法で得られた前駆体繊維は、引張弾性率の点では優れるものの、断面形状が円形ではなく大きく歪んでいるため、この前駆体繊維から得られる炭素繊維は従来のＰＡＮ系炭素繊維のような高い引張強度を示さない。従って結局、高引張強度及び高引張弾性率という二つの特性を両立させた炭素繊維は未だ得られていない。 However, although the precursor fiber obtained by the method of Patent Document 1 is excellent in terms of tensile elastic modulus, since the cross-sectional shape is not circular but is greatly distorted, the carbon fiber obtained from this precursor fiber is a conventional PAN. It does not show high tensile strength like the carbon fiber. Therefore, after all, a carbon fiber having both the high tensile strength and the high tensile elastic modulus has not been obtained yet.
本発明は、かかる従来技術の現状に鑑み創案されたものであり、その目的は、高引張強度（具体的には６ＧＰａ以上の引張強度）かつ高引張弾性率（具体的には３００ＧＰａ以上の引張弾性率）の炭素繊維を製造することができる前駆体繊維及びその製造方法を提供することにある。 The present invention has been developed in view of the current state of the prior art, and its purpose is to have a high tensile strength (specifically, a tensile strength of 6 GPa or higher) and a high tensile modulus (specifically, a tensile strength of 300 GPa or higher). It is an object of the present invention to provide a precursor fiber capable of producing a carbon fiber having a modulus of elasticity and a method for producing the same.
本発明者は、上記目的を達成するために、特許文献１の方法の改良について鋭意検討した結果、特許文献１の方法で得られるカーボンナノチューブ含有ＰＡＮ系前駆体繊維の断面形状が大きく歪む理由は、紡糸原液の溶剤としてジメチルホルムアミド（ＤＭＦ）を使用しているためであり、ロダン塩の水溶液を紡糸原液の溶剤として使用すると、略円形断面のカーボンナノチューブ含有ＰＡＮ系前駆体繊維が得られることを見出した。しかし、溶剤としてＤＭＦの代わりにロダン塩の水溶液を使用すると、紡糸原液にカーボンナノチューブ分散液を添加した際に瞬時にカーボンナノチューブが凝集・析出しやすく、得られた凝固糸中に凝集・析出物の塊が散在するため、延伸時にこの塊を起点に糸切れを生じやすく、十分な延伸を行うことができないこと、このため前駆体繊維中のポリマー鎖及びカーボンナノチューブの配向が不十分になり、カーボンナノチューブの添加により本来期待されるべき高い引張強度および引張弾性率を発現することができないことが判明した。また、カーボンナノチューブが紡糸原液中で多量に凝集・析出すると、紡糸原液の曵糸性がなくなったり、紡糸口金のフィルター詰まりを起こし、紡糸不可能になることが判明した。そこで、本発明者らは、ロダン塩の水溶液を紡糸原液の溶剤として使用しつつも紡糸原液中のカーボンナノチューブの析出を抑制する方法についてさらに検討したところ、予めポリアクリロニトリル系ポリマー中にカーボンナノチューブを分散しておき、これをロダン塩水溶液に溶解すると、カーボンナノチューブが安定に溶剤中に分散されて凝集・析出しにくくなることを見出し、本発明の完成に至った。 As a result of earnestly examining the improvement of the method of Patent Document 1 in order to achieve the above object, the present inventor has the reason that the cross-sectional shape of the carbon nanotube-containing PAN-based precursor fiber obtained by the method of Patent Document 1 is greatly distorted. This is because dimethylformamide (DMF) is used as a solvent for the spinning dope. When an aqueous solution of rhodan salt is used as the solvent for the spinning dope, a carbon nanotube-containing PAN precursor fiber having a substantially circular cross section can be obtained. I found it. However, when an aqueous solution of rhodan salt is used instead of DMF as a solvent, carbon nanotubes easily aggregate and precipitate instantly when a carbon nanotube dispersion is added to the spinning dope, and aggregates and precipitates are obtained in the obtained coagulated yarn. Since the lump of lump is scattered, thread breakage tends to occur at the start of this lump at the time of stretching, and sufficient stretching cannot be performed, and therefore the orientation of polymer chains and carbon nanotubes in the precursor fiber becomes insufficient, It has been found that the addition of carbon nanotubes cannot exhibit the high tensile strength and tensile elastic modulus that are originally expected. It was also found that if carbon nanotubes agglomerate and precipitate in a large amount in the spinning dope, the spinning dope loses spinnability or the spinneret filter becomes clogged, making spinning impossible. Therefore, the present inventors further examined a method for suppressing the precipitation of carbon nanotubes in the spinning stock solution while using an aqueous solution of rhodan salt as a solvent for the spinning stock solution. As a result, carbon nanotubes were previously incorporated into the polyacrylonitrile-based polymer. When dispersed and dissolved in an aqueous rhodan salt solution, it was found that the carbon nanotubes are stably dispersed in the solvent and are difficult to aggregate and precipitate, and the present invention has been completed.
即ち、本発明によれば、以下の工程を含むことを特徴とする、炭素繊維の前駆体繊維の製造方法が提供される：
（１）ジメチルホルムアミド、ジメチルアセトアミド、Ｎ−メチル−２−ピロリドン、及びジメチルスルホキシドからなる群から選択される少なくとも一種の有機溶剤にカーボンナノチューブとポリアクリロニトリル系ポリマーを分散・溶解させてカーボンナノチューブ分散液を調製する工程；
（２）このカーボンナノチューブ分散液を濃縮する工程；
（３）この濃縮したカーボンナノチューブ分散液を貧溶媒中で凝固し、ろ別、乾燥して、カーボンナノチューブを含有するポリアクリロニトリル系ポリマーを調製する工程；
（４）このカーボンナノチューブを含有するポリアクリロニトリル系ポリマーをロダン塩の水溶液に溶解させ、紡糸原液を調製する工程；
（５）この紡糸原液から、湿式又は乾湿式紡糸法によって凝固糸を得る工程；そして
（６）この凝固糸を延伸して炭素繊維の前駆体繊維を得る工程。
That is, according to the present invention, there is provided a method for producing a carbon fiber precursor fiber, which comprises the following steps:
(1) A carbon nanotube dispersion liquid in which carbon nanotubes and a polyacrylonitrile-based polymer are dispersed and dissolved in at least one organic solvent selected from the group consisting of dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, and dimethyl sulfoxide. The step of preparing
(2) a step of concentrating the carbon nanotube dispersion;
(3) a step of coagulating the concentrated carbon nanotube dispersion in a poor solvent, filtering and drying to prepare a polyacrylonitrile-based polymer containing carbon nanotubes;
(4) A step of preparing a spinning dope by dissolving the polyacrylonitrile-based polymer containing the carbon nanotubes in an aqueous solution of rhodan salt;
(5) a step of obtaining a coagulated yarn from the spinning solution by a wet or dry wet spinning method; and (6) a step of drawing the coagulated yarn to obtain a precursor fiber of carbon fiber.
また、本発明によれば、上記方法によって製造される、炭素繊維の前駆体繊維であって、略円形断面を有しかつカーボンナノチューブを含むことを特徴とする炭素繊維の前駆体繊維が提供される。 In addition, according to the present invention, there is provided a carbon fiber precursor fiber produced by the above method, wherein the carbon fiber precursor fiber has a substantially circular cross section and includes carbon nanotubes. The
さらに、本発明によれば、上記前駆体繊維を耐炎化、予備炭素化及び炭素化することによって製造される炭素繊維であって、６ＧＰａ以上の引張強度及び３００ＧＰａ以上の引張弾性率を有することを特徴とする炭素繊維が提供される。 Furthermore, according to the present invention, a carbon fiber produced by flame-proofing, pre-carbonizing and carbonizing the precursor fiber, having a tensile strength of 6 GPa or more and a tensile modulus of 300 GPa or more. Characteristic carbon fibers are provided.
さらに、本発明によれば、ロダン塩、ポリアクリロニトリル系ポリマー、及びカーボンナノチューブを含む水溶液からなる紡糸原液であって、ポリアクリロニトリル系ポリマーの分散作用によりカーボンナノチューブが水中に分散していることを特徴とする紡糸原液が提供される。 Furthermore, according to the present invention, a spinning dope comprising an aqueous solution containing a rhodan salt, a polyacrylonitrile-based polymer, and carbon nanotubes, wherein the carbon nanotubes are dispersed in water by the dispersing action of the polyacrylonitrile-based polymer. A spinning dope is provided.
本発明のカーボンナノチューブ含有ＰＡＮ系前駆体繊維の製造方法では、紡糸原液の溶剤としてロダン塩の水溶液を使用しているので、略円形断面の前駆体繊維を得ることができる。また、ポリアクリロニトリル系ポリマーを分散剤として使用して紡糸原液からのカーボンナノチューブの凝集・析出を抑制しているため、得られた糸は、凝集・析出物の塊を含まず、また、糸中にはポリアクリロニトリルとカーボンナノチューブ以外の成分が存在しないため、ポリマー鎖とカーボンナノチューブとが直接に相互作用し、十分に延伸させてポリマー鎖及びカーボンナノチューブを配向させることができる。従って、かかる前駆体繊維から得られる炭素繊維は、適切に配向されたカーボンナノチューブの含有およびポリマー鎖の配向に起因する高い引張強度及び高い引張弾性率を示す。 In the method for producing a carbon nanotube-containing PAN precursor fiber of the present invention, an aqueous solution of rhodan salt is used as a solvent for the spinning dope, so that a precursor fiber having a substantially circular cross section can be obtained. In addition, since the polyacrylonitrile-based polymer is used as a dispersant to suppress the aggregation / precipitation of carbon nanotubes from the spinning dope, the obtained yarn does not contain agglomeration / precipitation lump. Since there are no components other than polyacrylonitrile and carbon nanotubes, the polymer chains and carbon nanotubes can directly interact and be sufficiently stretched to align the polymer chains and carbon nanotubes. Accordingly, carbon fibers obtained from such precursor fibers exhibit high tensile strength and high tensile modulus due to the inclusion of properly oriented carbon nanotubes and the orientation of the polymer chains.
以下、本発明のカーボンナノチューブ含有ＰＡＮ系炭素繊維の前駆体繊維の製造方法について詳述する。本発明の製造方法ではまず、ジメチルホルムアミド、ジメチルアセトアミド、Ｎ−メチル−２−ピロリドン、及びジメチルスルホキシドからなる群から選択される少なくとも一種の有機溶剤中にカーボンナノチューブとポリアクリロニトリル系ポリマーを分散・溶解させてカーボンナノチューブ分散液を調製する。（工程（１））。 Hereinafter, the manufacturing method of the precursor fiber of the carbon nanotube containing PAN system carbon fiber of this invention is explained in full detail. In the production method of the present invention, first, a carbon nanotube and a polyacrylonitrile-based polymer are dispersed and dissolved in at least one organic solvent selected from the group consisting of dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, and dimethylsulfoxide. To prepare a carbon nanotube dispersion. (Step (1)).
工程（１）では、例えばジメチルホルムアミド、ジメチルアセトアミド、Ｎ−メチル−２−ピロリドン、及びジメチルスルホキシドからなる群から選択される少なくとも一種の有機溶剤１００ｍｌに対して、カーボンナノチューブ１〜２０ｍｇ、より好ましくは１〜１５ｍｇが添加される。ポリアクリロニトリル系ポリマーの量は、カーボンナノチューブの量に対して重量で０．１〜１００倍であることが好ましく、さらに好ましくは１〜１００倍、特に好ましくは１〜２０倍である。有機溶剤は、上述のジメチルホルムアミド、ジメチルアセトアミド、Ｎ−メチル−２−ピロリドン、ジメチルスルホキシドを単独で使用してもよいし、これらの溶剤を適宜組合せて使用してもよい。 In the step (1), for example, 1 to 20 mg of carbon nanotubes with respect to 100 ml of at least one organic solvent selected from the group consisting of dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, and dimethyl sulfoxide, more preferably 1-15 mg is added. The amount of the polyacrylonitrile-based polymer is preferably 0.1 to 100 times by weight, more preferably 1 to 100 times, and particularly preferably 1 to 20 times the weight of the carbon nanotubes. As the organic solvent, the above-mentioned dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, and dimethylsulfoxide may be used alone, or these solvents may be used in appropriate combination.
ジメチルホルムアミド、ジメチルアセトアミド、Ｎ−メチル−２−ピロリドン、及びジメチルスルホキシドからなる群から選択される少なくとも一種の有機溶剤中へのカーボンナノチューブの分散は、超音波照射によって行わせることができる。超音波照射は、例えば約０〜７０℃の温度で約１時間〜３日間行う。溶液が目視で黒色透明になれば、カーボンナノチューブは十分分散している。 Dispersion of the carbon nanotubes in at least one organic solvent selected from the group consisting of dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, and dimethyl sulfoxide can be performed by ultrasonic irradiation. The ultrasonic irradiation is performed, for example, at a temperature of about 0 to 70 ° C. for about 1 hour to 3 days. If the solution becomes transparent and black, the carbon nanotubes are sufficiently dispersed.
本発明で使用するカーボンナノチューブは、単層カーボンナノチューブ、二層カーボンナノチューブ、多層カーボンナノチューブのいずれであっても良く、これらの混合物であっても良い。各種カーボンナノチューブの末端は、閉じていても良いし、穴が開いていても良い。カーボンナノチューブの直径は、好ましくは０．４ｎｍ以上１００ｎｍ以下であり、より好ましくは０．８ｎｍ以上８０ｎｍ以下である。カーボンナノチューブの長さは、制限されるものではなく、任意の長さのものを用いることができるが、好ましくは０．６μｍ以上２００μｍ以下である。 The carbon nanotube used in the present invention may be a single-walled carbon nanotube, a double-walled carbon nanotube, a multi-walled carbon nanotube, or a mixture thereof. The ends of various carbon nanotubes may be closed or perforated. The diameter of the carbon nanotube is preferably 0.4 nm or more and 100 nm or less, and more preferably 0.8 nm or more and 80 nm or less. The length of the carbon nanotube is not limited, and an arbitrary length can be used, but it is preferably 0.6 μm or more and 200 μm or less.
本発明で使用するカーボンナノチューブの純度は、炭素純度として８０％以上であることが好ましく、より好ましくは９０％以上、さらに好ましくは９５％以上である。炭素純度は、示差熱分析により決定される。カーボンナノチューブの不純物としては、非晶炭素成分や触媒金属が挙げられる。空気中での２００℃以上での加熱、または、過酸化水素水で洗浄することにより、非晶炭素成分を除くことができる。さらに、塩酸、硝酸、硫酸等の鉱酸で洗浄後、水洗することにより鉄等のカーボンナノチューブ製造時の触媒金属を除去することができる。本発明では、これらの精製操作を組み合わせることにより、種々の不純物を除去し、炭素純度を高めたカーボンナノチューブを使用することが好ましい。 The purity of the carbon nanotube used in the present invention is preferably 80% or more as carbon purity, more preferably 90% or more, and further preferably 95% or more. Carbon purity is determined by differential thermal analysis. Examples of carbon nanotube impurities include amorphous carbon components and catalytic metals. The amorphous carbon component can be removed by heating in air at 200 ° C. or higher or by washing with hydrogen peroxide. Furthermore, after washing with a mineral acid such as hydrochloric acid, nitric acid, sulfuric acid, etc., the catalyst metal during the production of carbon nanotubes such as iron can be removed by washing with water. In the present invention, it is preferable to use carbon nanotubes in which various impurities are removed and carbon purity is increased by combining these purification operations.
本発明で使用するポリアクリロニトリル系ポリマーとしては、ポリアクリロニトリル、および、アクリロニトリルと共重合可能なビニル単量体からなる共重合体を使うことができる。共重合体としては、耐炎化反応に有効な作用を有するアクリロニトリル−メタクリル酸共重合体、アクリロニトリル−メタクリル酸メチル共重合体、アクリロニトリル−アクリル酸共重合体、アクリロニトリル−イタコン酸共重合体、アクリロニトリル−メタクリル酸−イタコン酸共重合体、アクリロニトリル−メタクリル酸メチル−イタコン酸共重合体、アクリロニトリル−アクリル酸−イタコン酸共重合体等が挙げられ、いずれの場合もアクリロニトリル成分が８５モル％以上であることが好ましい。これらのポリマーは、アルカリ金属またはアンモニアとの塩を形成していても良い。また、これらのポリマーは単独または２種以上の混合物としても使用できる。 As the polyacrylonitrile-based polymer used in the present invention, polyacrylonitrile and a copolymer composed of a vinyl monomer copolymerizable with acrylonitrile can be used. Examples of the copolymer include acrylonitrile-methacrylic acid copolymer, acrylonitrile-methyl methacrylate copolymer, acrylonitrile-acrylic acid copolymer, acrylonitrile-itaconic acid copolymer, acrylonitrile Examples include methacrylic acid-itaconic acid copolymer, acrylonitrile-methyl methacrylate-itaconic acid copolymer, acrylonitrile-acrylic acid-itaconic acid copolymer, and in any case, the acrylonitrile component should be 85 mol% or more. Is preferred. These polymers may form a salt with alkali metal or ammonia. These polymers can be used alone or as a mixture of two or more.
次に、工程（１）で得られたカーボンナノチューブ分散液を濃縮する（工程（２））。具体的には、ジメチルホルムアミド、ジメチルアセトアミド、Ｎ−メチル−２−ピロリドン、及びジメチルスルホキシドからなる群から選択される少なくとも一種の有機溶剤にポリアクリロニトリル系ポリマーを予め溶解しておいた母液に上記カーボンナノチューブ分散液を適宜加えながら、溶媒を留去する。母液に加えるポリアクリロニトリル系ポリマーの量は、ポリアクリロニトリル系ポリマーの合計量に対するカーボンナノチューブの量が、好ましくは０．０１〜５重量％、さらに好ましくは０．１〜５重量％、特に好ましくは０．１〜３重量％になるように調整される。上記下限未満では、得られる前駆体繊維中のカーボンナノチューブ量が少なくなり、十分高い引張弾性率を達成できないおそれがある。また、上記上限を越えると、紡糸原液に曵糸性がなくなり、紡糸が困難になるおそれがある。溶媒の留去は、常圧蒸留、減圧蒸留、または、減圧下エバポレーターを用いることによって行うことができる。濃縮濃度は特に限定されるものではなく、例えば、ポリアクリロニトリル系ポリマー１５ｇに対して溶媒が７０〜５００ｍｌ、好ましくは９０〜３００ｍｌ程度になるように濃縮される。 Next, the carbon nanotube dispersion liquid obtained in the step (1) is concentrated (step (2)). Specifically, the carbon is added to a mother liquor in which a polyacrylonitrile-based polymer is previously dissolved in at least one organic solvent selected from the group consisting of dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, and dimethyl sulfoxide. The solvent is distilled off while appropriately adding the nanotube dispersion. The amount of the polyacrylonitrile-based polymer added to the mother liquor is preferably 0.01 to 5% by weight, more preferably 0.1 to 5% by weight, particularly preferably 0, based on the total amount of the polyacrylonitrile-based polymer. 0.1 to 3% by weight. If it is less than the said minimum, there exists a possibility that the amount of carbon nanotubes in the precursor fiber obtained may decrease and a sufficiently high tensile elastic modulus cannot be achieved. On the other hand, if the above upper limit is exceeded, the spinning dope loses spinnability, and spinning may be difficult. The solvent can be distilled off by atmospheric distillation, vacuum distillation, or using an evaporator under reduced pressure. Concentration concentration is not specifically limited, For example, it concentrates so that a solvent may be about 70-500 ml with respect to 15 g of polyacrylonitrile-type polymers, Preferably it is about 90-300 ml.
次に、この濃縮したカーボンナノチューブ分散液を貧溶媒中で凝固し、ろ別、乾燥して、カーボンナノチューブを含有するポリアクリロニトリル系ポリマーを調製する（工程（３））。貧溶媒としては、メタノール、エタノール、プロパノール等のアルコール、水等を用いることができる。乾燥は、風乾または減圧下、室温〜１００℃で行うことができる。 Next, this concentrated carbon nanotube dispersion is coagulated in a poor solvent, filtered and dried to prepare a polyacrylonitrile-based polymer containing carbon nanotubes (step (3)). As the poor solvent, alcohols such as methanol, ethanol and propanol, water and the like can be used. Drying can be performed at room temperature to 100 ° C under air drying or reduced pressure.
次に、工程（３）で得られたカーボンナノチューブを含有するポリアクリロニトリル系ポリマーをロダン塩の水溶液に溶解させ、紡糸原液を調製する（工程（４））。ポリアクリロニトリル系ポリマーの溶解量は、紡糸原液中、５〜３０重量％になるような量であることが好ましく、さらに好ましくは１０〜２０重量％になるような量である。上記下限未満では、紡糸張力をかけることができず、繊維自身および糸中のカーボンナノチューブの配向が不足し、強度不足の原因となるおそれがある。また、上記下限を越えると紡糸時に背圧上昇の原因となるおそれがある。 Next, the polyacrylonitrile-based polymer containing the carbon nanotubes obtained in the step (3) is dissolved in an aqueous solution of rhodan salt to prepare a spinning dope (step (4)). The amount of the polyacrylonitrile-based polymer dissolved is preferably such that it is 5 to 30% by weight, more preferably 10 to 20% by weight in the spinning dope. If it is less than the above lower limit, the spinning tension cannot be applied, and the orientation of the carbon itself and the carbon nanotubes in the yarn is insufficient, which may cause insufficient strength. On the other hand, if the above lower limit is exceeded, there is a risk of increasing the back pressure during spinning.
工程（４）で使用するロダン塩は、チオシアン酸と１価または２価の金属との塩であればよく、中でもチオシアン酸ナトリウム、チオシアン酸カリウムが好ましい。また、これらの混合物を用いることもできる。ロダン塩は極めて溶解しにくいため、この工程は、液を激しく攪拌しながら行うことが好ましい。また、ロダン塩は長時間（例えば２時間程度）かけて徐々に添加することが好ましい。必要により、ロダン塩を完全に溶解させるため、液を約３０℃〜約９０℃に加熱してもよい。 The rhodan salt used in the step (4) may be a salt of thiocyanic acid and a monovalent or divalent metal, and among them, sodium thiocyanate and potassium thiocyanate are preferable. A mixture of these can also be used. Since rhodan salts are extremely difficult to dissolve, this step is preferably carried out with vigorous stirring of the liquid. The rhodan salt is preferably added gradually over a long period of time (for example, about 2 hours). If necessary, the solution may be heated to about 30 ° C. to about 90 ° C. to completely dissolve the rhodan salt.
ロダン塩の添加量は、紡糸原液中、３０〜６０重量％になるような量であることが好ましく、さらには４０〜５５重量％であることが好ましい。上記下限未満では、ポリアクリロニトリル系ポリマーが溶解できないおそれがある。また、上記上限を越えると、ロダン塩が析出したり、いったん分散したカーボンナノチューブが凝集し、析出してしまうおそれがある。 The amount of rhodan salt added is preferably 30-60% by weight, more preferably 40-55% by weight in the spinning dope. If it is less than the lower limit, the polyacrylonitrile-based polymer may not be dissolved. Moreover, when the above upper limit is exceeded, there is a possibility that rhodan salts precipitate or carbon nanotubes once dispersed aggregate and precipitate.
以上の工程（１）〜（４）によって得られた紡糸原液は、ロダン塩、ポリアクリロニトリル系ポリマー、及びカーボンナノチューブを含む水溶液からなる。この水溶液中では、ポリアクリロニトリル系ポリマーの分散作用によりカーボンナノチューブが水中に安定に分散しており、何らかの衝撃が加えられても析出しにくくなっている。 The spinning dope obtained by the above steps (1) to (4) is composed of an aqueous solution containing a rhodan salt, a polyacrylonitrile-based polymer, and carbon nanotubes. In this aqueous solution, the carbon nanotubes are stably dispersed in water due to the dispersing action of the polyacrylonitrile-based polymer, and it is difficult for the carbon nanotubes to be precipitated even if any impact is applied.
本発明の紡糸原液の粘度は、通常３０℃で、湿式紡糸では、２〜２０Ｐａ・ｓｅｃであることが好ましく、乾湿式紡糸では１００〜５００Ｐａ・ｓｅｃであることが好ましい。それぞれの紡糸方法において、上記範囲を下回ると、紡糸時にノズル面に紡糸原液が付着してしまう恐れがあったり、吐出糸条の切断や品質斑の問題があり、上記範囲を上回ると、メルトフラクチャーが生じて安定に紡糸を行うことができなくなるなど、紡糸の操業性に問題が生じるおそれがある。 The viscosity of the spinning dope of the present invention is usually 30 ° C., preferably 2 to 20 Pa · sec for wet spinning, and preferably 100 to 500 Pa · sec for dry and wet spinning. In each spinning method, if the range is below the above range, there is a possibility that the spinning solution may adhere to the nozzle surface at the time of spinning, or there is a problem of cutting of the discharged yarn or quality unevenness. This may cause problems in spinning operability, such as inability to perform stable spinning.
次に、この紡糸原液から、湿式又は乾湿式紡糸法によって凝固糸を得る（工程（５））。 Next, a coagulated yarn is obtained from this spinning dope by a wet or dry wet spinning method (step (5)).
紡糸口金の孔径は、通常、湿式紡糸では０．０３〜０．１ｍｍであることが好ましく、乾湿式紡糸では０．１〜０．３ｍｍであることが好ましい。上記範囲を下回ると、紡糸時にドラフト比が小さくなり生産性を著しく損なうおそれがあったり、吐出糸条の切断や品質斑の問題があり、上記範囲を上回ると、紡糸原液の吐出線速度が小さくなり凝固槽内での糸の張力が大きくなるなど、紡糸の操業性に問題が生じるおそれがある。 In general, the hole diameter of the spinneret is preferably 0.03 to 0.1 mm for wet spinning, and preferably 0.1 to 0.3 mm for dry and wet spinning. Below the above range, the draft ratio may decrease during spinning and the productivity may be significantly impaired, and there is a problem of cutting of the discharged yarn and quality unevenness. When the above range is exceeded, the discharge linear velocity of the spinning dope becomes low. Therefore, there is a risk of problems in spinning operability such as an increase in yarn tension in the coagulation tank.
凝固浴としては、水、塩化亜鉛もしくは塩化アルミニウム等のルイス酸塩水溶液、又はロダン塩水溶液を用いることが好ましい。ルイス酸塩又はロダン塩の濃度は１０〜２０重量％であることが好ましく、温度は−５〜１０℃に保つことが好ましい。ルイス酸塩又はロダン塩の濃度が１０重量％未満では、吐出された紡糸原液の表面から急速に凝固が進み、繊維中心部の凝固が不充分となり、均一な糸の構造形成が行われないおそれがある。また、２０重量％よりも濃度が高いと、凝固が遅くなり、巻き取りまでの工程で隣接する糸同士の接着を生じるおそれがある。また、凝固は多段で行われることが好ましく、特に好ましくは２〜３段で行われる。凝固が１段の場合、糸中心部までの凝固が不充分となり、均一な糸構造の形成ができないおそれがある。また、４段以上では、生産設備が重厚となり、現実的でない。 As the coagulation bath, it is preferable to use water, a Lewis acid salt aqueous solution such as zinc chloride or aluminum chloride, or a rhodan salt aqueous solution. The concentration of the Lewis acid salt or rhodan salt is preferably 10 to 20% by weight, and the temperature is preferably maintained at -5 to 10 ° C. If the concentration of the Lewis acid salt or the rhodan salt is less than 10% by weight, solidification rapidly proceeds from the surface of the discharged spinning stock solution, and the coagulation of the fiber center becomes insufficient, so that a uniform yarn structure may not be formed. There is. On the other hand, when the concentration is higher than 20% by weight, the solidification is slowed, and there is a possibility that adjacent yarns are bonded in the process up to winding. Further, the solidification is preferably performed in multiple stages, particularly preferably in 2 to 3 stages. When solidification is performed in one stage, solidification to the center of the yarn is insufficient, and there is a possibility that a uniform yarn structure cannot be formed. In addition, if there are four or more stages, the production equipment becomes heavy, which is not realistic.
紡糸時の引き取り速度は、３〜２０ｍ／分の範囲にあることが好ましい。３ｍ／分未満では、生産性が極めて低くなるおそれがある。一方、２０ｍ／分を越えると、紡糸口金近傍での糸切れが多発し、操業性を著しく損なうおそれがある。 The take-up speed during spinning is preferably in the range of 3 to 20 m / min. If it is less than 3 m / min, the productivity may be extremely low. On the other hand, if it exceeds 20 m / min, yarn breakage frequently occurs in the vicinity of the spinneret and the operability may be significantly impaired.
次に、工程（５）で得られた凝固糸を延伸して炭素繊維の前駆体繊維を得る（工程（６））。延伸することによって、繊維中の分子鎖の配向性を高めて力学物性に優れた炭素繊維を得ることができる。延伸は、トータルの延伸倍率が４〜１２倍になるように行うことが好ましく、より好ましくは、トータルの延伸倍率が５〜７倍になるように行う。トータルの延伸倍率が上記下限未満では、糸中のカーボンナノチューブの配向が不充分で、ポリアクリロニトリル系ポリマーが緻密に配向した炭素繊維前駆体を得ることができないおそれがある。また、トータルの延伸倍率が上記上限を越える場合は、延伸時に糸切れが頻発し、延伸安定性に欠けるおそれがある。延伸操作は、冷延伸、熱水中での延伸、蒸気中での延伸のいずれの方法でも良い。また、１度に延伸しても、多段で延伸しても良い。 Next, the coagulated yarn obtained in the step (5) is drawn to obtain a carbon fiber precursor fiber (step (6)). By stretching, a carbon fiber excellent in mechanical properties can be obtained by increasing the orientation of molecular chains in the fiber. The stretching is preferably performed so that the total stretching ratio is 4 to 12 times, and more preferably, the total stretching ratio is 5 to 7 times. If the total draw ratio is less than the above lower limit, the orientation of the carbon nanotubes in the yarn is insufficient, and it may not be possible to obtain a carbon fiber precursor in which the polyacrylonitrile polymer is densely oriented. Further, when the total draw ratio exceeds the above upper limit, yarn breakage frequently occurs during drawing and there is a possibility that the drawing stability may be lacking. The stretching operation may be any of cold stretching, stretching in hot water, and stretching in steam. Moreover, even if it extends | stretches at once, you may extend | stretch in multiple steps.
以上の工程（１）〜（６）によって得られた前駆体繊維は、高引張強度を発揮するのに必要な略円形断面を有し、しかも高引張弾性率をもたらすカーボンナノチューブを適切な配向で含む。従って、この前駆体繊維を耐炎化、予備炭素化、及び炭素化すれば、６ＧＰａ以上の引張強度及び３００ＧＰａ以上の引張弾性率を有する高強度高弾性率の炭素繊維を得ることができる。なお、本発明の炭素繊維の引張強度及び引張弾性率の上限は特に制限されないが、実際にはそれぞれ１２ＧＰａ及び８００ＧＰａ程度である。 The precursor fibers obtained by the above steps (1) to (6) have a substantially circular cross section necessary for exhibiting high tensile strength, and carbon nanotubes that provide high tensile elastic modulus in an appropriate orientation. Including. Therefore, if this precursor fiber is flame-resistant, pre-carbonized, and carbonized, a high-strength and high-modulus carbon fiber having a tensile strength of 6 GPa or more and a tensile modulus of 300 GPa or more can be obtained. The upper limits of the tensile strength and tensile modulus of the carbon fiber of the present invention are not particularly limited, but are actually about 12 GPa and 800 GPa, respectively.
本発明では、前駆体繊維の耐炎化、予備炭素化、及び炭素化は、常法に従って行えばよく、例えば、前駆体繊維をまず、空気中で延伸比０．８〜２．５で延伸しながら２００〜３００℃で耐炎化し、次に、不活性気体中で延伸比０．９〜１．５で延伸しながら３００〜８００℃に加熱して予備炭素化し、さらに、不活性気体中で延伸比０．９〜１．１で１０００〜２０００℃に加熱して炭素化することによって炭素繊維を得ることができる。 In the present invention, the flame resistance, pre-carbonization, and carbonization of the precursor fiber may be performed according to conventional methods. For example, the precursor fiber is first stretched in air at a stretch ratio of 0.8 to 2.5. While flame-proofing at 200 to 300 ° C., pre-carbonization by heating to 300 to 800 ° C. while stretching in an inert gas at a stretch ratio of 0.9 to 1.5, and further stretching in an inert gas Carbon fibers can be obtained by heating to 1000 to 2000 ° C. at a ratio of 0.9 to 1.1 for carbonization.
予備炭素化処理および炭素化処理時に用いられる不活性気体としては、窒素、アルゴン、キセノン、および二酸化炭素等が挙げられる。経済的な観点からは窒素が好ましく用いられる。炭素化処理時の最高到達温度は所望の炭素繊維の力学物性に応じて１２００〜３０００℃の間で設定される。一般的に炭素化処理の最高到達温度が高い程、得られる炭素繊維の引張弾性率が大きくなる。一方、引張強度は１５００℃で極大となる。本発明では、炭素化処理を１０００〜２０００℃、より好ましくは１２００〜１７００℃、さらに好ましくは１３００〜１６００℃で行うことにより、引張弾性率と引張強度の２つの力学物性を最大限に発現させることが可能である。 Examples of the inert gas used during the preliminary carbonization treatment and the carbonization treatment include nitrogen, argon, xenon, and carbon dioxide. Nitrogen is preferably used from an economical viewpoint. The maximum temperature achieved during the carbonization treatment is set between 1200 ° C. and 3000 ° C. according to the desired mechanical properties of the carbon fiber. Generally, the higher the maximum temperature reached in the carbonization treatment, the higher the tensile modulus of the carbon fiber obtained. On the other hand, the tensile strength reaches a maximum at 1500 ° C. In the present invention, the carbonization treatment is performed at 1000 to 2000 ° C., more preferably 1200 to 1700 ° C., and further preferably 1300 to 1600 ° C., so that the two mechanical properties of the tensile elastic modulus and the tensile strength are maximized. It is possible.
以下、実施例で本発明をさらに具体的に説明するが、本発明はこれらの実施例により限定されるものではない。 EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.
なお、本実施例で得た炭素繊維の引張強度および引張弾性率は、ＪＩＳ Ｒ７６０６（２０００）「炭素繊維−単繊維の引張特性の試験方法」に従ってＮＭＢ社製引張試験機「ＴＧ２００ＮＢ」を用いて測定した。 The tensile strength and tensile modulus of the carbon fiber obtained in this example were measured using a tensile tester “TG200NB” manufactured by NMB in accordance with JIS R7606 (2000) “Testing method for tensile properties of carbon fiber-single fiber”. It was measured.
実施例１
紡糸原液の調製：ジメチルホルムアミド３６００ｍｌに、二層カーボンナノチューブ（Ｕｎｉｄｙｍ社製ＸＯグレード）０．１５ｇ、ＡＮ９４−ＭＡＡ６共重合体１．５ｇを添加し、超音波装置（日本精機社製Ｕｌｔｒａｓｏｎｉｃ Ｈｏｍｏｇｅｎｉｚｅｒ ＭＯＤＥＬ ＵＳ−３００Ｔ）で２０ｋＨｚ、３００Ｗの超音波を２４時間照射して、カーボンナノチューブ分散液を得た。５００ｍｌセパラブルフラスコ中で予めＡＮ９４−ＭＡＡ６共重合体１３．５ｇをジメチルホルムアミド１００ｍｌに溶解させておき、上記カーボンナノチューブ分散液を３０ｍｌずつ追加しながら１５ｍｍＨｇ、３５℃でジメチルホルムアミド３６００ｍｌを留去してカーボンナノチューブ分散液を濃縮した。この濃縮したカーボンナノチューブ分散液をメタノール５Ｌ中に激しく撹拌しながら滴下し、滴下終了後１昼夜静置した後、沈殿物をろ取し、５ｍｍＨｇ、３０℃で２４時間乾燥して、カーボンナノチューブを含有するポリアクリロニトリル系ポリマーを得た。これを水４０．８ｇ中に添加し、そこにチオシアン酸ナトリウム４４．２ｇを４０℃で２時間以上かけて加え、さらに１０時間撹拌して紡糸原液を得た。
Example 1
Preparation of spinning dope: To 3600 ml of dimethylformamide, 0.15 g of double-walled carbon nanotubes (Xy grade manufactured by Unidym) and 1.5 g of AN94-MAA6 copolymer were added, and an ultrasonic device (Ultrasonic Homogenizer MODEL US manufactured by Nippon Seiki Co., Ltd.). -300T) was irradiated with ultrasonic waves of 20 kHz and 300 W for 24 hours to obtain a carbon nanotube dispersion. In a 500 ml separable flask, 13.5 g of AN94-MAA6 copolymer was previously dissolved in 100 ml of dimethylformamide, and 3600 ml of dimethylformamide was distilled off at 15 mmHg and 35 ° C. while adding 30 ml of the above carbon nanotube dispersion. The carbon nanotube dispersion was concentrated. This concentrated carbon nanotube dispersion was dropped into 5 L of methanol with vigorous stirring and allowed to stand for 1 day after completion of dropping, and then the precipitate was collected by filtration and dried at 5 mmHg and 30 ° C. for 24 hours to obtain carbon nanotubes. A polyacrylonitrile-based polymer was obtained. This was added to 40.8 g of water, and 44.2 g of sodium thiocyanate was added thereto at 40 ° C. over 2 hours and further stirred for 10 hours to obtain a spinning dope.
紡糸：上記紡糸原液を８０℃にて孔径０．１５ｍｍ、孔数１０の紡糸口金から押し出し、エアギャップ長５ｍｍを経て０℃の１５重量％チオシアン酸ナトリウム水溶液１５ｌからなる凝固浴中へ導入した後、５重量％チオシアン酸ナトリウム水溶液で水洗した。その後、２倍に延伸し、水洗し、さらに０．２重量％硝酸で洗浄した。この後、さらにこの糸を沸騰水中で３倍延伸を行い、アミノ変性シリコーン油剤を付与して、１５０℃、５分間乾燥することにより、単糸繊度１．０ｄＴｅｘの前駆体繊維を得た。この繊維の断面形状を図１に示す。図１からわかるように、略円形断面の前駆体繊維が得られた。 Spinning: After spinning the above spinning solution from a spinneret having a pore diameter of 0.15 mm and a number of holes of 10 at 80 ° C., and introducing it into a coagulation bath consisting of 15 l of a 15 wt% sodium thiocyanate aqueous solution at 0 ° C. through an air gap length of 5 mm Washed with 5% by weight aqueous sodium thiocyanate. Thereafter, the film was stretched twice, washed with water, and further washed with 0.2 wt% nitric acid. Thereafter, the yarn was further stretched 3 times in boiling water, an amino-modified silicone oil agent was applied, and the yarn was dried at 150 ° C. for 5 minutes to obtain a precursor fiber having a single yarn fineness of 1.0 dTex. The cross-sectional shape of this fiber is shown in FIG. As can be seen from FIG. 1, precursor fibers having a substantially circular cross section were obtained.
耐炎化処理：上記の前駆体繊維を空気中で一定長にて、１段目２２０℃、２段目２３０℃、３段目２４０℃、４段目２５０℃でそれぞれ１時間加熱して、比重１．３８の耐炎化処理糸を得た。
予備炭素化処理：上記耐炎化処理糸を窒素気流中で一定長にて、７００℃で２分間加熱して予備炭素化処理糸を得た。
炭素化処理：上記予備炭素化処理糸を窒素気流中で一定長にて、１３００℃で２分間加熱して炭素繊維を得た。得られた炭素繊維の引張強度及び引張弾性率を表１に示す。
Flameproofing treatment: The above precursor fibers were heated in air at a constant length for 1 hour at the first stage 220 ° C, the second stage 230 ° C, the third stage 240 ° C, and the fourth stage 250 ° C, respectively. A 1.38 flameproof yarn was obtained.
Precarbonization treatment: The flameproofing yarn was heated at 700 ° C. for 2 minutes in a nitrogen stream at a constant length to obtain a precarbonized yarn.
Carbonization treatment: The precarbonized yarn was heated at 1300 ° C. for 2 minutes in a nitrogen stream at a constant length to obtain carbon fibers. Table 1 shows the tensile strength and tensile modulus of the obtained carbon fiber.
実施例２
実施例１において二層カーボンナノチューブの代わりに単層カーボンナノチューブ（ＣＮＩ社製Ｈｉｐｃｏ）を使用した以外は実施例１と同様にして炭素繊維を得た。得られた炭素繊維の引張強度及び引張弾性率を表１に示す。なお、前駆体繊維の断面形状を確認したところ、実施例１と同様に略円形断面であった。
Example 2
Carbon fibers were obtained in the same manner as in Example 1 except that single-walled carbon nanotubes (Hipco manufactured by CNI) were used instead of double-walled carbon nanotubes in Example 1. Table 1 shows the tensile strength and tensile modulus of the obtained carbon fiber. In addition, when the cross-sectional shape of the precursor fiber was confirmed, it was a substantially circular cross section as in Example 1.
実施例３
実施例１において二層カーボンナノチューブの代わりに多層カーボンナノチューブ（Ｂａｙｅｒ社製Ｂａｙｔｕｂｅｓ）を使用した以外は実施例１と同様にして炭素繊維を得た。得られた炭素繊維の引張強度及び引張弾性率を表１に示す。なお、前駆体繊維の断面形状を確認したところ、実施例１と同様に略円形断面であった。
Example 3
Carbon fibers were obtained in the same manner as in Example 1 except that multi-walled carbon nanotubes (Baytubes manufactured by Bayer) were used instead of double-walled carbon nanotubes in Example 1. Table 1 shows the tensile strength and tensile modulus of the obtained carbon fiber. In addition, when the cross-sectional shape of the precursor fiber was confirmed, it was a substantially circular cross section as in Example 1.
実施例４
実施例１においてＡＮ９４−ＭＡＡ６共重合体の代わりにＡＮ９５−ＭＡ５共重合体を使用した以外は、実施例１と同様にして炭素繊維を得た。得られた炭素繊維の引張強度及び引張弾性率を表１に示す。なお、前駆体繊維の断面形状を確認したところ、実施例１と同様に略円形断面であった。
Example 4
Carbon fibers were obtained in the same manner as in Example 1 except that AN95-MA5 copolymer was used instead of AN94-MAA6 copolymer in Example 1. Table 1 shows the tensile strength and tensile modulus of the obtained carbon fiber. In addition, when the cross-sectional shape of the precursor fiber was confirmed, it was a substantially circular cross section as in Example 1.
実施例５
実施例３においてＡＮ９４−ＭＡＡ６共重合体の代わりにＡＮ９５−ＭＡＡ４−ＩＡ１共重合体を使用した以外は、実施例３と同様にして炭素繊維を得た。得られた炭素繊維の引張強度及び引張弾性率を表１に示す。なお、前駆体繊維の断面形状を確認したところ、実施例１と同様に略円形断面であった。
Example 5
A carbon fiber was obtained in the same manner as in Example 3 except that AN95-MAA4-IA1 copolymer was used instead of AN94-MAA6 copolymer in Example 3. Table 1 shows the tensile strength and tensile modulus of the obtained carbon fiber. In addition, when the cross-sectional shape of the precursor fiber was confirmed, it was a substantially circular cross section as in Example 1.
実施例６
実施例１においてＡＮ９４−ＭＡＡ６共重合体の代わりにＰＡＮを使用した以外は、実施例１と同様にして炭素繊維を得た。得られた炭素繊維の引張強度及び引張弾性率を表１に示す。なお、前駆体繊維の断面形状を確認したところ、実施例１と同様に略円形断面であった。
Example 6
Carbon fibers were obtained in the same manner as in Example 1 except that PAN was used instead of the AN94-MAA6 copolymer in Example 1. Table 1 shows the tensile strength and tensile modulus of the obtained carbon fiber. In addition, when the cross-sectional shape of the precursor fiber was confirmed, it was a substantially circular cross section as in Example 1.
実施例７
実施例６において二層カーボンナノチューブの代わりに単層カーボンナノチューブを使用した以外は、実施例６と同様にして炭素繊維を得た。得られた炭素繊維の引張強度及び引張弾性率を表１に示す。なお、前駆体繊維の断面形状を確認したところ、実施例１と同様に略円形断面であった。
Example 7
Carbon fibers were obtained in the same manner as in Example 6 except that single-walled carbon nanotubes were used instead of double-walled carbon nanotubes in Example 6. Table 1 shows the tensile strength and tensile modulus of the obtained carbon fiber. In addition, when the cross-sectional shape of the precursor fiber was confirmed, it was a substantially circular cross section as in Example 1.
実施例８
実施例４において二層カーボンナノチューブの代わりに多層カーボンナノチューブを使用した以外は、実施例４と同様にして炭素繊維を得た。得られた炭素繊維の引張強度及び引張り弾性率を表１に示す。なお、前駆体繊維の断面形状を確認したところ、実施例１と同様に略円形断面であった。
Example 8
Carbon fibers were obtained in the same manner as in Example 4 except that multi-walled carbon nanotubes were used instead of double-walled carbon nanotubes in Example 4. Table 1 shows the tensile strength and tensile modulus of the obtained carbon fiber. In addition, when the cross-sectional shape of the precursor fiber was confirmed, it was a substantially circular cross section as in Example 1.
実施例９
実施例１においてジメチルホルムアミドの代わりにジメチルアセトアミドを使用した以外は、実施例１と同様にして炭素繊維を得た。得られた炭素繊維の引張強度及び引張り弾性率を表１に示す。なお、前駆体繊維の断面形状を確認したところ、実施例１と同様に略円形断面であった。
Example 9
Carbon fibers were obtained in the same manner as in Example 1 except that dimethylacetamide was used instead of dimethylformamide in Example 1. Table 1 shows the tensile strength and tensile modulus of the obtained carbon fiber. In addition, when the cross-sectional shape of the precursor fiber was confirmed, it was a substantially circular cross section as in Example 1.
実施例１０
実施例１において二層カーボンナノチューブを１．０ｇ使用した以外は、実施例１と同様にして炭素繊維を得た。得られた炭素繊維の引張強度及び引張り弾性率を表１に示す。なお、前駆体繊維の断面形状を確認したところ、実施例１と同様に略円形断面であった。
Example 10
A carbon fiber was obtained in the same manner as in Example 1 except that 1.0 g of the double-walled carbon nanotube was used in Example 1. Table 1 shows the tensile strength and tensile modulus of the obtained carbon fiber. In addition, when the cross-sectional shape of the precursor fiber was confirmed, it was a substantially circular cross section as in Example 1.
実施例１１
実施例１においてジメチルホルムアミドの代わりにジメチルスルホキシドを使用した以外は、実施例１と同様にして炭素繊維を得た。得られた炭素繊維の引張強度及び引張り弾性率を表１に示す。なお、前駆体繊維の断面形状を確認したところ、実施例１と同様に略円形断面であった。
Example 11
Carbon fibers were obtained in the same manner as in Example 1 except that dimethyl sulfoxide was used instead of dimethylformamide in Example 1. Table 1 shows the tensile strength and tensile modulus of the obtained carbon fiber. In addition, when the cross-sectional shape of the precursor fiber was confirmed, it was a substantially circular cross section as in Example 1.
実施例１２
実施例１においてジメチルホルムアミドの代わりにＮ−メチル−２−ピロリドンを使用した以外は、実施例１と同様にして炭素繊維を得た。得られた炭素繊維の引張強度及び引張り弾性率を表１に示す。なお、前駆体繊維の断面形状を確認したところ、実施例１と同様に略円形断面であった。
Example 12
Carbon fibers were obtained in the same manner as in Example 1 except that N-methyl-2-pyrrolidone was used instead of dimethylformamide in Example 1. Table 1 shows the tensile strength and tensile modulus of the obtained carbon fiber. In addition, when the cross-sectional shape of the precursor fiber was confirmed, it was a substantially circular cross section as in Example 1.
実施例１３
実施例１においてジメチルホルムアミドの代わりにＮ−メチル−２−ピロリドンとジメチルホルムアミドの１：１（容量比）混合溶媒を使用した以外は、実施例１と同様にして炭素繊維を得た。得られた炭素繊維の引張強度及び引張り弾性率を表１に示す。なお、前駆体繊維の断面形状を確認したところ、実施例１と同様に略円形断面であった。
Example 13
Carbon fibers were obtained in the same manner as in Example 1 except that a 1: 1 (volume ratio) mixed solvent of N-methyl-2-pyrrolidone and dimethylformamide was used instead of dimethylformamide in Example 1. Table 1 shows the tensile strength and tensile modulus of the obtained carbon fiber. In addition, when the cross-sectional shape of the precursor fiber was confirmed, it was a substantially circular cross section as in Example 1.
実施例１４
実施例１においてジメチルホルムアミドの代わりにＮ−メチル−２−ピロリドンとジメチルスルホキシドの１：１（容量比）混合溶媒を使用した以外は、実施例１と同様にして炭素繊維を得た。得られた炭素繊維の引張強度及び引張り弾性率を表１に示す。なお、前駆体繊維の断面形状を確認したところ、実施例１と同様に略円形断面であった。
Example 14
Carbon fibers were obtained in the same manner as in Example 1, except that a 1: 1 (volume ratio) mixed solvent of N-methyl-2-pyrrolidone and dimethyl sulfoxide was used instead of dimethylformamide. Table 1 shows the tensile strength and tensile modulus of the obtained carbon fiber. In addition, when the cross-sectional shape of the precursor fiber was confirmed, it was a substantially circular cross section as in Example 1.
比較例１
紡糸原液の調製：５００ｍｌナスフラスコに水３９．２ｍｌと水分含有率２５％のＡＮ９４−ＭＡＡ６共重合体２０ｇを測り取り、撹拌してスラリー状にした。撹拌しながらチオシアン酸ナトリウム４４．２ｇを２時間かけて添加した。室温で１時間撹拌した後、６０℃まで加熱して均一な紡糸原液を得た。紡糸、耐炎化処理、予備炭素化処理、炭素化処理については実施例１と同様に処理を行い、炭素繊維を得た。得られた炭素繊維の引張強度及び引張弾性率を表１に示す。なお、前駆体繊維の断面形状を確認したところ、実施例１と同様に略円形断面であった。
Comparative Example 1
Preparation of spinning dope: In a 500 ml eggplant flask, 39.2 ml of water and 20 g of AN94-MAA6 copolymer having a water content of 25% were weighed and stirred to form a slurry. While stirring, 44.2 g of sodium thiocyanate was added over 2 hours. After stirring for 1 hour at room temperature, the mixture was heated to 60 ° C. to obtain a uniform spinning dope. Spinning, flameproofing treatment, preliminary carbonization treatment, and carbonization treatment were carried out in the same manner as in Example 1 to obtain carbon fibers. Table 1 shows the tensile strength and tensile modulus of the obtained carbon fiber. In addition, when the cross-sectional shape of the precursor fiber was confirmed, it was a substantially circular cross section as in Example 1.
比較例２
紡糸原液の調製：ジメチルホルムアミド６００ｍｌに二層カーボンナノチューブ（Ｕｎｉｄｙｍ社製ＸＯグレード）０．０２５ｇを添加し、超音波装置（ＢＲＡＮＳＯＮ ３５１０Ｒ ＭＴ）で４２ｋＨｚ，１００Ｗの超音波を３６時間照射した。この分散液を合計６本調製した。５００ｍｌ三口フラスコ中でジメチルホルムアミド１００ｍｌを撹拌しながら乾燥したＡＮ９４−ＭＡＡ６共重合体１５ｇを３０分間かけて添加した。７０℃１５分間加熱して均一な溶液にした。室温まで放冷後、上記のカーボンナノチューブ分散液を１５０ｍｌずつ添加してジメチルホルムアミド３６００ｍｌを留去して紡糸原液とした。
Comparative Example 2
Preparation of spinning stock solution: 0.025 g of double-walled carbon nanotubes (XO grade manufactured by Unidym) was added to 600 ml of dimethylformamide, and ultrasonic waves of 42 kHz and 100 W were irradiated for 36 hours with an ultrasonic device (BRANSON 3510R MT). A total of 6 dispersions were prepared. While stirring 100 ml of dimethylformamide in a 500 ml three-necked flask, 15 g of dried AN94-MAA6 copolymer was added over 30 minutes. A uniform solution was obtained by heating at 70 ° C. for 15 minutes. After allowing to cool to room temperature, 150 ml of the above carbon nanotube dispersion was added and 3600 ml of dimethylformamide was distilled off to obtain a spinning dope.
紡糸：上記紡糸原液を８０℃にて孔径０．１５ｍｍ、孔数１の紡糸口金から押し出し、エアギャップ長４０ｍｍを経て−６０℃に冷却したメタノール１５ｌからなる凝固浴中へ導入し、糸を巻き取った。−６０℃のメタノール中に１昼夜糸を漬けた後、９倍延伸を行い、アミノ変性シリコーン油剤を付与して、１５０℃、５分間乾燥することにより、単糸繊度１．８ｄＴｅｘの前駆体繊維を得た。この繊維の断面形状を図２に示す。図２からわかるように、この前駆体繊維は略円形断面ではなく、歪な断面形状をしている。 Spinning: The above spinning solution is extruded from a spinneret having a pore diameter of 0.15 mm and a number of holes of 1 at 80 ° C., introduced into a coagulation bath consisting of 15 l of methanol cooled to −60 ° C. through an air gap length of 40 mm, and the yarn is wound I took it. After dipping the yarn for one day in methanol at -60 ° C, the fiber is stretched 9 times, provided with an amino-modified silicone oil, and dried at 150 ° C for 5 minutes to give a precursor fiber having a single yarn fineness of 1.8 dTex. Got. The cross-sectional shape of this fiber is shown in FIG. As can be seen from FIG. 2, this precursor fiber has a distorted cross-sectional shape rather than a substantially circular cross-section.
耐炎化処理、予備炭素化処理、炭素化処理を実施例１と同様にして行い炭素繊維を得た。得られた炭素繊維の引張強度及び引張弾性率を表１に示す。 Flame proofing treatment, preliminary carbonization treatment, and carbonization treatment were carried out in the same manner as in Example 1 to obtain carbon fibers. Table 1 shows the tensile strength and tensile modulus of the obtained carbon fiber.
表１からわかるように、カーボンナノチューブを添加し、紡糸原液の溶剤としてロダン塩水溶液を使用し、分散剤としてポリアクリロニトリル系ポリマーを使用した実施例１〜１４はいずれも、高い引張強度及び引張弾性率の炭素繊維が得られているのに対し、カーボンナノチューブを使用せず、分散剤を使用しなかった比較例１（従来の一般的なＰＡＮ系炭素繊維）は、引張強度は高いが引張弾性率が劣る。また、カーボンナノチューブは使用したが、紡糸原液の溶剤としてＤＭＦを使用し、分散剤も使用しなかった比較例２（特許文献１の炭素繊維）は、引張弾性率は比較例１より高いが、繊維の断面が歪んでいるため、引張強度が劣る。 As can be seen from Table 1, each of Examples 1 to 14, in which carbon nanotubes were added, a rhodan salt aqueous solution was used as the solvent for the spinning dope, and a polyacrylonitrile-based polymer was used as the dispersant, all had high tensile strength and tensile elasticity. In comparison example 1 (conventional general PAN-based carbon fiber) in which no carbon nanotubes were used and no dispersant was used, the tensile strength was high, but tensile elasticity was obtained. The rate is inferior. Moreover, although the carbon nanotube was used, but the comparative example 2 (carbon fiber of patent document 1) which used DMF as a solvent of a spinning undiluted | stock solution and did not use a dispersing agent has higher tensile elasticity modulus than the comparative example 1, Since the cross section of the fiber is distorted, the tensile strength is inferior.
本発明の製造方法によって得られた前駆体繊維を使用すれば、高い引張強度と高い引張弾性率を兼ね備えた炭素繊維を得ることができる。かかる炭素繊維は、航空機材料や宇宙船材料として極めて有用である。 If the precursor fiber obtained by the production method of the present invention is used, a carbon fiber having both high tensile strength and high tensile elastic modulus can be obtained. Such carbon fibers are extremely useful as aircraft materials and spacecraft materials.
Claims (5)
（１）ジメチルホルムアミド、ジメチルアセトアミド、Ｎ−メチル−２−ピロリドン、及びジメチルスルホキシドからなる群から選択される少なくとも一種の有機溶剤にカーボンナノチューブとポリアクリロニトリル系ポリマーを分散・溶解させてカーボンナノチューブ分散液を調製する工程；
（２）このカーボンナノチューブ分散液を濃縮する工程；
（３）この濃縮したカーボンナノチューブ分散液を貧溶媒中で凝固し、ろ別、乾燥して、カーボンナノチューブを含有するポリアクリロニトリル系ポリマーを調製する工程；
（４）このカーボンナノチューブを含有するポリアクリロニトリル系ポリマーをロダン塩の水溶液に溶解させ、紡糸原液を調製する工程；
（５）この紡糸原液から、湿式又は乾湿式紡糸法によって凝固糸を得る工程；そして
（６）この凝固糸を延伸して炭素繊維の前駆体繊維を得る工程。 A method for producing a carbon fiber precursor fiber, comprising the following steps:
(1) A carbon nanotube dispersion liquid in which carbon nanotubes and a polyacrylonitrile-based polymer are dispersed and dissolved in at least one organic solvent selected from the group consisting of dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, and dimethyl sulfoxide. The step of preparing
(2) a step of concentrating the carbon nanotube dispersion;
(3) a step of coagulating the concentrated carbon nanotube dispersion in a poor solvent, filtering and drying to prepare a polyacrylonitrile-based polymer containing carbon nanotubes;
(4) A step of preparing a spinning dope by dissolving the polyacrylonitrile-based polymer containing the carbon nanotubes in an aqueous solution of rhodan salt;
(5) a step of obtaining a coagulated yarn from the spinning solution by a wet or dry wet spinning method; and (6) a step of drawing the coagulated yarn to obtain a precursor fiber of carbon fiber.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2010005744A JP5261405B2 (en) | 2009-01-16 | 2010-01-14 | Method for producing precursor fiber for obtaining high strength and high modulus carbon fiber |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2009007806 | 2009-01-16 | ||
| JP2009007806 | 2009-01-16 | ||
| JP2010005744A JP5261405B2 (en) | 2009-01-16 | 2010-01-14 | Method for producing precursor fiber for obtaining high strength and high modulus carbon fiber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2010185163A true JP2010185163A (en) | 2010-08-26 |
| JP5261405B2 JP5261405B2 (en) | 2013-08-14 |
Family
ID=42765984
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2010005744A Active JP5261405B2 (en) | 2009-01-16 | 2010-01-14 | Method for producing precursor fiber for obtaining high strength and high modulus carbon fiber |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5261405B2 (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2568064A1 (en) * | 2011-09-07 | 2013-03-13 | Teijin Aramid B.V. | Carbon nanotubes fiber having low resistivity |
| WO2013034672A3 (en) * | 2011-09-07 | 2013-04-25 | Teijin Aramid B.V. | Carbon nanotubes fiber having low resistivity, high modulus and/or high thermal conductivity and a method of preparing such fibers by spinning using a fiber spin-dope |
| CN103198932A (en) * | 2013-02-27 | 2013-07-10 | 国家纳米科学中心 | Carbon-based composite fiber electrode material, manufacturing method and application thereof |
| WO2014204282A1 (en) * | 2013-06-21 | 2014-12-24 | 코오롱인더스트리 주식회사 | Polyacrylonitrile-based precursor fiber for carbon fibre, and production method therefor |
| WO2019209009A1 (en) * | 2018-04-27 | 2019-10-31 | 주식회사 엘지화학 | Method for stabilizing precursor fibers for manufacturing carbon fibers, and method for manufacturing carbon fibers by using same |
| KR20190125184A (en) * | 2018-04-27 | 2019-11-06 | 주식회사 엘지화학 | Stabilization method of precusor fiber for preparing carbon fiber and preparation method of carbon fiber using the same |
| KR20200073561A (en) * | 2018-12-14 | 2020-06-24 | 주식회사 엘지화학 | Method for producing stabilized fiber for carbon fiber and preparation method of carbon fiber using the same |
| CN114751396A (en) * | 2022-03-28 | 2022-07-15 | 中山大学 | Preparation method of serpentine buckling carbon nanofiber |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR102309004B1 (en) * | 2016-03-30 | 2021-10-05 | 코오롱인더스트리 주식회사 | Polyacrylronitrile type carbon fiber and method of manufacturing the same |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6852410B2 (en) * | 2002-07-01 | 2005-02-08 | Georgia Tech Research Corporation | Macroscopic fiber comprising single-wall carbon nanotubes and acrylonitrile-based polymer and process for making the same |
| JP2006200114A (en) * | 2004-12-21 | 2006-08-03 | Mitsubishi Rayon Co Ltd | Acrylic fiber, method for producing the same and carbon fiber |
| JP2010530929A (en) * | 2007-01-30 | 2010-09-16 | ジョージア テック リサーチ コーポレイション | Carbon fiber and carbon film, and production method thereof |
-
2010
- 2010-01-14 JP JP2010005744A patent/JP5261405B2/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6852410B2 (en) * | 2002-07-01 | 2005-02-08 | Georgia Tech Research Corporation | Macroscopic fiber comprising single-wall carbon nanotubes and acrylonitrile-based polymer and process for making the same |
| JP2006200114A (en) * | 2004-12-21 | 2006-08-03 | Mitsubishi Rayon Co Ltd | Acrylic fiber, method for producing the same and carbon fiber |
| JP2010530929A (en) * | 2007-01-30 | 2010-09-16 | ジョージア テック リサーチ コーポレイション | Carbon fiber and carbon film, and production method thereof |
Cited By (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013034672A3 (en) * | 2011-09-07 | 2013-04-25 | Teijin Aramid B.V. | Carbon nanotubes fiber having low resistivity, high modulus and/or high thermal conductivity and a method of preparing such fibers by spinning using a fiber spin-dope |
| JP2014530964A (en) * | 2011-09-07 | 2014-11-20 | テイジン・アラミド・ビー．ブイ． | Carbon nanotube fiber having low resistivity, high elastic modulus, and / or high thermal conductivity, and method for producing the fiber by spinning using fiber spinning dope |
| KR101936562B1 (en) | 2011-09-07 | 2019-01-10 | 데이진 아라미드 비.브이. | Carbon nanotubes fiber having low resistivity, high modulus and/or high thermal conductivity and a method of preparing such fibers by spinning using a fiber spin-dope |
| EP2568064A1 (en) * | 2011-09-07 | 2013-03-13 | Teijin Aramid B.V. | Carbon nanotubes fiber having low resistivity |
| CN103198932B (en) * | 2013-02-27 | 2017-05-03 | 国家纳米科学中心 | Carbon-based composite fiber electrode material, manufacturing method and application thereof |
| CN103198932A (en) * | 2013-02-27 | 2013-07-10 | 国家纳米科学中心 | Carbon-based composite fiber electrode material, manufacturing method and application thereof |
| KR20140148343A (en) * | 2013-06-21 | 2014-12-31 | 코오롱인더스트리 주식회사 | Polyacrylonitrile Precursor for Carbon Fiber and Method for Preparing the Same |
| JP2016540131A (en) * | 2013-06-21 | 2016-12-22 | コーロン インダストリーズ インク | Polyacrylonitrile-based precursor fiber for carbon fiber and method for producing the same |
| CN105392930A (en) * | 2013-06-21 | 2016-03-09 | 可隆工业株式会社 | Polyacrylonitrile-based precursor fiber for carbon fibre, and production method therefor |
| WO2014204282A1 (en) * | 2013-06-21 | 2014-12-24 | 코오롱인더스트리 주식회사 | Polyacrylonitrile-based precursor fiber for carbon fibre, and production method therefor |
| KR101625739B1 (en) * | 2013-06-21 | 2016-06-13 | 코오롱인더스트리 주식회사 | Polyacrylonitrile Precursor for Carbon Fiber and Method for Preparing the Same |
| CN111801451B (en) * | 2018-04-27 | 2023-03-03 | 株式会社Lg化学 | Method for stabilizing precursor fiber for producing carbon fiber and method for producing carbon fiber using the same |
| WO2019209009A1 (en) * | 2018-04-27 | 2019-10-31 | 주식회사 엘지화학 | Method for stabilizing precursor fibers for manufacturing carbon fibers, and method for manufacturing carbon fibers by using same |
| KR20190125184A (en) * | 2018-04-27 | 2019-11-06 | 주식회사 엘지화학 | Stabilization method of precusor fiber for preparing carbon fiber and preparation method of carbon fiber using the same |
| KR102147418B1 (en) * | 2018-04-27 | 2020-08-24 | 주식회사 엘지화학 | Stabilization method of precusor fiber for preparing carbon fiber and preparation method of carbon fiber using the same |
| CN111801451A (en) * | 2018-04-27 | 2020-10-20 | 株式会社Lg化学 | Method for stabilizing precursor fiber for producing carbon fiber and method for producing carbon fiber using the same |
| KR20200073561A (en) * | 2018-12-14 | 2020-06-24 | 주식회사 엘지화학 | Method for producing stabilized fiber for carbon fiber and preparation method of carbon fiber using the same |
| KR102530522B1 (en) | 2018-12-14 | 2023-05-10 | 주식회사 엘지화학 | Method for producing stabilized fiber for carbon fiber and preparation method of carbon fiber using the same |
| CN114751396A (en) * | 2022-03-28 | 2022-07-15 | 中山大学 | Preparation method of serpentine buckling carbon nanofiber |
| CN114751396B (en) * | 2022-03-28 | 2024-04-02 | 中山大学 | Preparation method of snakelike buckling carbon nanofiber |
Also Published As
| Publication number | Publication date |
|---|---|
| JP5261405B2 (en) | 2013-08-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5261405B2 (en) | Method for producing precursor fiber for obtaining high strength and high modulus carbon fiber | |
| JP5536439B2 (en) | Method for producing precursor fiber for obtaining high strength and high modulus carbon fiber | |
| JP5697258B2 (en) | Method for producing precursor fiber for obtaining high strength and high modulus carbon fiber | |
| JP5251524B2 (en) | Method for producing precursor fiber for obtaining high strength and high modulus carbon fiber | |
| JP4940948B2 (en) | Flame resistant fiber, carbon fiber and method for producing them | |
| JP5261367B2 (en) | Method for producing precursor fiber for obtaining high strength and high modulus carbon fiber | |
| JP2011500978A (en) | Carbon fiber and film and method for producing the same | |
| CN101250770A (en) | Method for manufacturing polyacrylonitrile-based carbon fiber with enganced carbon nano-tube | |
| CN101768798B (en) | Preparation method of sodium alga acid/ carbon nano tube composite fibre | |
| WO2011102400A1 (en) | Production method for precursor fibre for obtaining high-strength and high elastic modulus carbon fibre | |
| JP2009197365A (en) | Method for producing precursor fiber of carbon fiber, and method for producing the carbon fiber | |
| JP2007182657A (en) | Polymer composition for carbon fiber precursor fiber | |
| JP2007291557A (en) | Carbon fiber and method for producing the same | |
| TWI422633B (en) | Polyacrylonitrile-based copolymer/cnt composites, carbon fibers and fabrication method of carbon fiber | |
| JP2015030926A (en) | Method of producing dope for acrylic fiber | |
| JPWO2020090597A1 (en) | Carbon fiber precursor fiber and method for producing carbon fiber | |
| JP4582819B1 (en) | Method for producing high-strength polyacrylonitrile-based carbon fiber | |
| JP2007186802A (en) | Method for producing flame retardant fiber and carbon fiber | |
| JP2010174161A (en) | Method for producing dispersion of polyacrylonitrile-based polymer for precursor fiber of carbon fiber | |
| JP2012193465A (en) | Acrylic precursor fiber for carbon fiber, method for producing the same, and carbon fiber obtained from the precursor fiber | |
| Ranjan et al. | Multi-walled carbon nanotube/polymer composite: a nano-enabled continuous fiber | |
| JP2007092185A (en) | Polyacrylonitrile polymer for carbon fiber precursor fiber | |
| JP2007211356A (en) | Method for producing carbon nanofiber | |
| JP2678384B2 (en) | Pitch for carbon fiber and method of manufacturing carbon fiber using the same | |
| JP2007321267A (en) | Method for producing polyacrylonitrile-based fiber and carbon fiber |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20121214 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20130409 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20130410 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20130426 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20160502 Year of fee payment: 3 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 5261405 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |