JP6217342B2 - Method for producing carbon fiber precursor acrylonitrile fiber - Google Patents
Method for producing carbon fiber precursor acrylonitrile fiber Download PDFInfo
- Publication number
- JP6217342B2 JP6217342B2 JP2013242487A JP2013242487A JP6217342B2 JP 6217342 B2 JP6217342 B2 JP 6217342B2 JP 2013242487 A JP2013242487 A JP 2013242487A JP 2013242487 A JP2013242487 A JP 2013242487A JP 6217342 B2 JP6217342 B2 JP 6217342B2
- Authority
- JP
- Japan
- Prior art keywords
- acrylonitrile
- polymer solution
- absorbance
- based polymer
- temperature
- 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.)
- Active
Links
Description
本発明は、炭素繊維前駆体アクリロニトリル系繊維の製造方法に関する。 The present invention relates to a method for producing a carbon fiber precursor acrylonitrile fiber.
炭素繊維は、他の繊維に比べて高い比強度及び比弾性率を有することが知られている。このため、複合材料用補強繊維として、従来からのスポーツ用途及び航空・宇宙用途に加え、自動車や土木、建築、圧力容器、風車ブレード等の一般産業用途にも幅広く展開されつつある。 It is known that carbon fibers have a high specific strength and specific elastic modulus compared to other fibers. For this reason, in addition to conventional sports and aerospace applications, composite fibers are being widely deployed in general industrial applications such as automobiles, civil engineering, architecture, pressure vessels, and windmill blades.
炭素繊維の中ではアクリロニトリル系炭素繊維が最も広く利用されている。アクリロニトリル系炭素繊維はアクリロニトリル系重合体を溶剤に溶解してアクリロニトリル系重合体溶液とし、これを用いて湿式紡糸または乾湿式紡糸して、炭素繊維前駆体アクリロニトリル系繊維を得た後、それを２００〜３００℃の酸化性雰囲気中にて加熱、耐炎化処理して耐炎化繊維とし、更に３００〜２５００℃の不活性雰囲気にて前記耐炎化繊維を加熱処理することにより得ることができる。しかし、このようにして得られた炭素繊維は、物性や品質には優れるものの、製造費用が高額になるため、特に低コスト化が求められる産業用途分野においては、多用化は十分に実現されていない。 Among the carbon fibers, acrylonitrile-based carbon fibers are the most widely used. The acrylonitrile-based carbon fiber is obtained by dissolving an acrylonitrile-based polymer in a solvent to obtain an acrylonitrile-based polymer solution, and using this to perform wet spinning or dry-wet spinning to obtain a carbon fiber precursor acrylonitrile-based fiber. It can be obtained by heating and flameproofing in an oxidizing atmosphere at ˜300 ° C. to obtain flameproofed fiber, and further heating the flameproofed fiber in an inert atmosphere at 300 to 2500 ° C. However, although the carbon fibers obtained in this way are excellent in physical properties and quality, they are expensive to manufacture, so that they are sufficiently realized especially in industrial applications where cost reduction is required. Absent.
炭素繊維の低コスト化を達成する手段として、炭素繊維前駆体アクリロニトリル系繊維の製造工程で使用するエネルギーコストを削減する方法がある。炭素繊維前駆体アクリロニトリル系繊維を得る方法としては、上述したとおり、アクリロニトリル系重合体溶液を用いて湿式紡糸または乾湿式紡糸する手法が広く採用されている。この方法では水膨潤状態の凝固糸を延伸して延伸糸とした後、乾燥緻密化処理する工程を含むことが一般的であり、その後更に延伸等の処理を施すことで炭素繊維前駆体アクリロニトリル系繊維が得られる。乾燥緻密化させる際は、加熱ロールを通しながら乾燥させることが一般的である。ロールの加熱には電気や蒸気といったエネルギーを使用するため、乾燥負荷を下げることはエネルギーコスト削減に繋がる。 As means for achieving a reduction in the cost of carbon fibers, there is a method of reducing energy costs used in the production process of the carbon fiber precursor acrylonitrile fiber. As a method for obtaining the carbon fiber precursor acrylonitrile fiber, a technique of wet spinning or dry wet spinning using an acrylonitrile polymer solution is widely adopted as described above. In this method, it is common to include a step of drawing a water-swelled coagulated yarn into a drawn yarn, followed by a drying densification treatment. Thereafter, the carbon fiber precursor acrylonitrile system is further subjected to a treatment such as drawing. Fiber is obtained. When drying and densifying, it is common to dry through a heating roll. Since energy such as electricity and steam is used for heating the roll, lowering the drying load leads to energy cost reduction.
特許文献１には炭素繊維前駆体アクリロニトリル系繊維を製造するにあたって、凝固浴の温度を低下させることで、凝固糸の膨潤度を低下させる方法が記載されている。凝固糸の膨潤度が低下することで、凝固糸に含まれる含水率も低下するため、凝固糸を延伸した延伸糸の含水率も低下し、結果的に乾燥負荷の低下につながり、エネルギーコストを削減できる。 Patent Document 1 describes a method for reducing the degree of swelling of a coagulated yarn by reducing the temperature of a coagulation bath when producing a carbon fiber precursor acrylonitrile fiber. As the degree of swelling of the coagulated yarn decreases, the moisture content contained in the coagulated yarn also decreases, so the moisture content of the drawn yarn obtained by stretching the coagulated yarn also decreases, resulting in a reduction in drying load and energy costs. Can be reduced.
しかし、特許文献１の方法では、凝固浴温度の低下に伴い、凝固浴中の凝固糸同士が接着してしまうため、炭素繊維前駆体アクリロニトリル系繊維製造工程中にて糸切れなどのトラブルを発生させてしまう。従って、炭素繊維前駆体アクリロニトリル系繊維を安定に製造しつつ、エネルギーコスト削減を達成することが困難であった。 However, in the method of Patent Document 1, since the coagulated yarn in the coagulation bath adheres as the coagulation bath temperature decreases, troubles such as yarn breakage occur during the production process of the carbon fiber precursor acrylonitrile fiber. I will let you. Therefore, it has been difficult to achieve energy cost reduction while stably producing the carbon fiber precursor acrylonitrile fiber.
本発明は、前記した問題を解決すること、すなわち、凝固浴温度を低下させることなく凝固糸の含水率を減らすことが可能である炭素繊維前駆体アクリロニトリル系繊維の製造方法を提供することを目的としている。 An object of the present invention is to solve the above-mentioned problem, that is, to provide a method for producing a carbon fiber precursor acrylonitrile fiber that can reduce the water content of the coagulated yarn without lowering the coagulation bath temperature. It is said.
前記の目的は、以下の発明によって解決される。
本発明の炭素繊維前駆体アクリロニトリル系繊維の製造方法は、アクリロニトリル系重合体と溶媒の混合物を溶解する溶解装置の排出口から、溶解装置で溶解された重合体溶液をノズル孔から吐出されるまでのアクリロニトリル系重合体溶液の通過時間が０．５時間〜２０．０時間であり、前記排出口から排出された時点から５分後の前記重合体溶液の温度が３０℃〜８５℃であり、その後からノズル孔から吐出されるまでの保持温度が３０℃〜８５℃である炭素繊維前駆体アクリロニトリル系繊維の製造方法である。
The above object is solved by the following invention.
The method for producing the carbon fiber precursor acrylonitrile fiber of the present invention is such that the polymer solution dissolved in the dissolving device is discharged from the nozzle hole from the outlet of the dissolving device for dissolving the mixture of the acrylonitrile polymer and the solvent. The passage time of the acrylonitrile-based polymer solution is 0.5 hours to 20.0 hours, and the temperature of the polymer solution 5 minutes after being discharged from the outlet is 30 ° C. to 85 ° C., It is a manufacturing method of the carbon fiber precursor acrylonitrile type | system | group fiber whose holding temperature until it discharges from a nozzle hole after that is 30 to 85 degreeC.
本発明の炭素繊維前駆体アクリロニトリル系繊維の製造方法は、前記保持が１．５時間〜１０時間であることが好ましい。 In the method for producing a carbon fiber precursor acrylonitrile fiber of the present invention, the retention is preferably 1.5 hours to 10 hours.
本発明の炭素繊維前駆体アクリロニトリル系繊維の製造方法は、前記保持温度が４５℃〜７５℃、前記通過時間が２．５時間〜５．５時間であることが好ましい。 In the method for producing a carbon fiber precursor acrylonitrile fiber of the present invention, the holding temperature is preferably 45 ° C. to 75 ° C., and the passing time is 2.5 hours to 5.5 hours.
本発明の炭素繊維前駆体アクリロニトリル系繊維の製造方法は、下記測定方法により得られる、前記溶解装置の排出口から排出された直後のアクリロニトリル系重合体溶液の吸光度Ａが０．０３０以上０．１６０以下であることが好ましい。
アクリロニトリル系重合体溶液の吸光度測定方法
アクリロニトリル系重合体溶液を溶液と同じ溶媒にて質量換算で２０倍に希釈し、厚さ１ｃｍのセルに入れ、波長３５０ｎｍにおける吸光度Ｘを測定する。また、溶媒のみを厚さ１ｃｍのセルに入れ、波長３５０ｎｍにおける吸光度Ｙを測定する。吸光度Ｘから吸光度Ｙの値を差し引いた値をアクリロニトリル系重合体溶液の吸光度とする。吸光度測定時の温度は３０℃とする。
The method for producing a carbon fiber precursor acrylonitrile fiber of the present invention has an absorbance A of 0.030 or more and 0.160 of the acrylonitrile polymer solution immediately after being discharged from the discharge port of the dissolution apparatus obtained by the following measurement method. The following is preferable.
Method for measuring absorbance of acrylonitrile-based polymer solution The acrylonitrile-based polymer solution is diluted 20-fold in terms of mass in the same solvent as the solution, placed in a cell having a thickness of 1 cm, and absorbance X at a wavelength of 350 nm is measured. Further, only the solvent is put into a cell having a thickness of 1 cm, and the absorbance Y at a wavelength of 350 nm is measured. The value obtained by subtracting the value of absorbance Y from absorbance X is defined as the absorbance of the acrylonitrile-based polymer solution. The temperature during the absorbance measurement is 30 ° C.
本発明の炭素繊維前駆体アクリロニトリル系繊維の製造方法は、ノズル吐出直後のアクリロニトリル系重合体溶液の吸光度Ｂが０．１６５以下であることが好ましい。 In the method for producing a carbon fiber precursor acrylonitrile fiber of the present invention, the absorbance B of the acrylonitrile polymer solution immediately after nozzle discharge is preferably 0.165 or less.
本発明の炭素繊維前駆体アクリロニトリル系繊維の製造方法は、前記吸光度Ａと前記吸光度Ｂの比であるＢ／Ａが１．０３０以上１．３５０以下であることが好ましい。 In the method for producing a carbon fiber precursor acrylonitrile fiber of the present invention, B / A, which is a ratio of the absorbance A to the absorbance B, is preferably 1.030 or more and 1.350 or less.
本発明の炭素繊維前駆体アクリロニトリル系繊維の製造方法は、凝固糸同士の接着を抑制しつつ、凝固糸の含水率を減らすことが可能となるため、乾燥緻密化時の乾燥負荷を下げることができ、結果的に炭素繊維前駆体アクリロニトリル系繊維の低コスト化が可能となる。 The method for producing a carbon fiber precursor acrylonitrile-based fiber of the present invention can reduce the moisture content of the coagulated yarn while suppressing the adhesion between the coagulated yarns, thereby reducing the drying load at the time of drying densification. As a result, the cost of the carbon fiber precursor acrylonitrile fiber can be reduced.
本発明の炭素繊維前駆体アクリロニトリル系繊維は、アクリロニトリル系重合体溶液を紡糸して得られる。また、アクリロニトリル系重合体溶液はアクリロニトリル系重合体を溶剤に溶解して得られる。
本発明で用いられるアクリロニトリル系重合体は、アクリロニトリルを主な単量体とし、これを重合して得られる重合体である。アクリロニトリル系重合体は、アクリロニトリルのみから得られるホモポリマーだけでなく、主成分であるアクリロニトリルに加えて他の単量体を用いたアクリロニトリル系重合体であってもよい。
The carbon fiber precursor acrylonitrile fiber of the present invention is obtained by spinning an acrylonitrile polymer solution. The acrylonitrile polymer solution is obtained by dissolving the acrylonitrile polymer in a solvent.
The acrylonitrile-based polymer used in the present invention is a polymer obtained by polymerizing acrylonitrile as a main monomer. The acrylonitrile-based polymer is not limited to a homopolymer obtained only from acrylonitrile, but may be an acrylonitrile-based polymer using other monomers in addition to the main component acrylonitrile.
アクリロニトリル系重合体中のアクリロニトリルの配合量は、得られる炭素繊維に求める品質等を勘案して決定でき、例えば、９０〜９９．５質量％であることが好ましく、９６〜９９．５質量％であることがより好ましい。アクリロニトリルの配合量が９０質量％以上であれば、前駆体繊維を炭素繊維に転換するための焼成工程で、繊維同士の融着を招くことがなく、炭素繊維の優れた品質及び性能を維持できる。加えて、アクリロニトリル系重合体の耐熱性が低下せず、前駆体繊維を紡糸する際に乾燥を抑制することができる。さらに、加熱ローラーや加圧水蒸気による延伸等の処理において、単繊維間の接着を回避できる。アクリロニトリルの配合量が９９．５質量％以下であれば、溶剤への溶解性が低下せず、アクリロニトリル系重合体の析出・凝固を防止し、紡糸原液の安定性が維持できるため、前駆体繊維を安定して製造できる。 The blending amount of acrylonitrile in the acrylonitrile-based polymer can be determined in consideration of the quality required for the obtained carbon fiber, and is preferably 90 to 99.5% by mass, for example, 96 to 99.5% by mass. More preferably. If the blending amount of acrylonitrile is 90% by mass or more, it is possible to maintain the excellent quality and performance of the carbon fiber without causing the fusion of the fibers in the firing step for converting the precursor fiber into the carbon fiber. . In addition, the heat resistance of the acrylonitrile polymer is not lowered, and drying can be suppressed when the precursor fiber is spun. Furthermore, adhesion between single fibers can be avoided in processing such as stretching with a heating roller or pressurized steam. If the amount of acrylonitrile is 99.5% by mass or less, the solubility in the solvent does not decrease, the precipitation / coagulation of the acrylonitrile polymer can be prevented, and the stability of the spinning dope can be maintained. Can be manufactured stably.
アクリロニトリル系重合体中のアクリロニトリル以外の単量体としては、アクリロニトリルと共重合可能なビニル系単量体から適宣選択することができ、アクリロニトリル系重合体の親水性を向上させるビニル系単量体、耐炎化促進効果を有するビニル系単量体が好ましい。 As the monomer other than acrylonitrile in the acrylonitrile polymer, a vinyl monomer that can be suitably selected from vinyl monomers copolymerizable with acrylonitrile and that improves the hydrophilicity of the acrylonitrile polymer. A vinyl monomer having an effect of promoting flame resistance is preferred.
アクリロニトリル系重合体の親水性を向上する単量体としては、例えば、カルボキシル基、スルホ基、アミノ基、アミド基、ヒドロキシル基等の親水性の官能基を有するビニル化合物がある。カルボキシル基を有する単量体としては、アクリル酸、メタクリル酸、イタコン酸、クロトン酸、シトラコン酸、エタクリル酸、マレイン酸、メサコン酸等が挙げられ、中でもアクリル酸、メタクリル酸、イタコン酸が好ましい。スルホ基を有する単量体としては、アリルスルホン酸、メタリルスルホン酸、スチレンスルホン酸、２−アクリルアミド−２−メチルプロパンスルホン酸、ビニルスルホン酸、スルホプロピルメタクリレート等が挙げられ、中でも、アリルスルホン酸、メタリルスルホン酸、スチレンスルホン酸、２−アクリルアミド−２−メチルプロパンスルホン酸が好ましい。アミノ基を有する単量体としては、ジメチルアミノエチルメタクリレート、ジエチルアミノエチルメタクリレート、ジメチルアミノエチルアクリレート、ジエチルアミノエチルアクリレート、ターシャリーブチルアミノエチルメタクリレート、アリルアミン、ｏ−アミノスチレン、ｐ−アミノスチレン等が挙げられ、中でもジメチルアミノエチルメタクリレート、ジエチルアミノエチルメタクリレート、ジメチルアミノエチルアクリレート、ジエチルアミノエチルアクリレートが好ましい。アミド基を有する単量体としては、アクリルアミド、メタクリルアミド、ジメチルアクリルアミド、クロトンアミドが好ましい。ヒドロキシル基を有する単量体としては、ヒドロキシメチルメタクリレート、ヒドロキシメチルアクリレート、２―ヒドロキシエチルメタクリレート、２−ヒドロキシエチルアクリレート、３−ヒドロキシプロピルメタクリレート、３−ヒドロキシプロピルアクリレート、２−ヒドロキシプロピルメタクリレート、２−ヒドロキシプロピルアクリレートなどが挙げられる。 Examples of the monomer that improves the hydrophilicity of the acrylonitrile-based polymer include vinyl compounds having a hydrophilic functional group such as a carboxyl group, a sulfo group, an amino group, an amide group, and a hydroxyl group. Examples of the monomer having a carboxyl group include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, citraconic acid, ethacrylic acid, maleic acid, mesaconic acid and the like, among which acrylic acid, methacrylic acid, and itaconic acid are preferable. Examples of the monomer having a sulfo group include allyl sulfonic acid, methallyl sulfonic acid, styrene sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, vinyl sulfonic acid, and sulfopropyl methacrylate. Acid, methallylsulfonic acid, styrenesulfonic acid, and 2-acrylamido-2-methylpropanesulfonic acid are preferred. Examples of the monomer having an amino group include dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, dimethylaminoethyl acrylate, diethylaminoethyl acrylate, tertiary butylaminoethyl methacrylate, allylamine, o-aminostyrene, and p-aminostyrene. Of these, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, dimethylaminoethyl acrylate, and diethylaminoethyl acrylate are preferable. As the monomer having an amide group, acrylamide, methacrylamide, dimethylacrylamide, and crotonamide are preferable. Examples of the monomer having a hydroxyl group include hydroxymethyl methacrylate, hydroxymethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 3-hydroxypropyl methacrylate, 3-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 2- And hydroxypropyl acrylate.
このような単量体を配合することで、アクリロニトリル系重合体は親水性が向上する。親水性が向上すると、得られる前駆体繊維の緻密性が向上し、表層部のミクロボイド発生を抑制することができる。上述の単量体は、１種単独で又は２種以上を適宜組み合わせて用いることができる。このようなアクリロニトリル系重合体の親水性を向上させる単量体の配合量は、アクリロニトリル系重合体中０．５〜１０．０質量％とすることが好ましく、０．５〜４．０質量％とすることがより好ましい。 By blending such a monomer, the hydrophilicity of the acrylonitrile polymer is improved. When the hydrophilicity is improved, the density of the obtained precursor fiber is improved, and generation of microvoids in the surface layer portion can be suppressed. The above-mentioned monomers can be used alone or in combination of two or more. The blending amount of the monomer for improving the hydrophilicity of such an acrylonitrile polymer is preferably 0.5 to 10.0% by mass in the acrylonitrile polymer, and preferably 0.5 to 4.0% by mass. More preferably.
耐炎化促進効果を有する単量体としては、アクリル酸、メタクリル酸、エタクリル酸、イタコン酸、クロトン酸、シトラコン酸、マレイン酸、メサコン酸又はこれらの低級アルキルエステル、アルカリ金属塩、アンモニウム塩もしくはアクリルアミド、メタクリルアミド等が挙げられる。中でも、少量の配合量でより高い耐炎化促進効果を得る観点から、カルボキシル基を有する単量体が好ましく、特にアクリル酸、メタクリル酸、イタコン酸等のビニル系単量体がより好ましい。このような単量体を配合することで、後述する耐炎化工程の時間を短縮でき、製造コストを低減できる。上述の単量体は、１種単独で又は２種以上を適宜組み合わせて用いることができる。このような耐炎化促進効果を有する単量体の配合量は、アクリロニトリル系重合体中０．５〜１０．０質量％であることが好ましく、０．５〜４．０質量％とすることがより好ましい。 Monomers having an effect of promoting flame resistance include acrylic acid, methacrylic acid, ethacrylic acid, itaconic acid, crotonic acid, citraconic acid, maleic acid, mesaconic acid or their lower alkyl esters, alkali metal salts, ammonium salts or acrylamides. , Methacrylamide and the like. Among these, from the viewpoint of obtaining a higher flame resistance-promoting effect with a small amount, a monomer having a carboxyl group is preferable, and vinyl monomers such as acrylic acid, methacrylic acid, and itaconic acid are particularly preferable. By mix | blending such a monomer, the time of the flame-proofing process mentioned later can be shortened, and manufacturing cost can be reduced. The above-mentioned monomers can be used alone or in combination of two or more. The blending amount of the monomer having the effect of promoting flame resistance is preferably 0.5 to 10.0% by mass, and preferably 0.5 to 4.0% by mass in the acrylonitrile-based polymer. More preferred.
本発明のアクリロニトリル系重合体の製造方法であるが、溶液重合や水系析出重合など公知のものを採用することが出来る。 Although it is a manufacturing method of the acrylonitrile-type polymer of this invention, well-known things, such as solution polymerization and aqueous precipitation polymerization, are employable.
アクリロニトリル系重合体溶液はアクリロニトリル系重合体が溶剤に溶解した溶液である。アクリロニトリル系重合体溶液は、アクリロニトリル系重合体と溶剤と混合し、下記１及び２に記載の特徴を持った溶解装置に通すことで得られる。
１．アクリロニトリル系重合体と溶剤を混合した混合液を加熱する加熱エリアを持つ
２．加熱エリア通過直後に溶解装置より排出される
The acrylonitrile polymer solution is a solution in which an acrylonitrile polymer is dissolved in a solvent. The acrylonitrile-based polymer solution is obtained by mixing an acrylonitrile-based polymer and a solvent and passing through a dissolving apparatus having the characteristics described in 1 and 2 below.
1. 1. It has a heating area for heating a mixed liquid in which an acrylonitrile-based polymer and a solvent are mixed. Immediately after passing through the heating area
また、溶液重合によりアクリロニトリル系重合体溶液を得ることもできる。また、溶液重合の場合は、溶解装置を重合装置と読み替える。溶液重合の装置としては、公知の重合装置を用いることができる。 An acrylonitrile-based polymer solution can also be obtained by solution polymerization. In the case of solution polymerization, the dissolving device is read as a polymerization device. A known polymerization apparatus can be used as the apparatus for solution polymerization.
溶解装置を用いる場合は、加熱エリアの装置形状は公知の熱交換器を用いることが出来き、バッチ式、連続式いずれのタイプでも問題ない。製造効率および設置スペースの観点から、連続式とすることが好ましく、伝熱効率やメンテナンス効率の観点から、熱交換器としてシェルアンドチューブタイプの単管もしくは多管式熱交換器が好ましい。また、加熱及び冷却媒体としては、例えば加圧蒸気やシリコンオイル、水など公知の加熱媒体を用いることができる。 In the case of using a melting apparatus, a known heat exchanger can be used as the apparatus shape of the heating area, and there is no problem with either a batch type or a continuous type. From the viewpoint of production efficiency and installation space, it is preferable to use a continuous type, and from the viewpoint of heat transfer efficiency and maintenance efficiency, a shell-and-tube type single-tube or multi-tube heat exchanger is preferable as a heat exchanger. Moreover, as a heating and cooling medium, well-known heating media, such as pressurized steam, silicon oil, and water, can be used, for example.
アクリロニトリル系重合体と溶剤を混合した混合液を加熱する加熱媒体の温度は、９０〜１６０℃とすることが好ましい。加熱媒体の温度が９０℃以上であれば、アクリロニトリル系重合体の溶解が均一にでき、未溶解物が少なくなるため、アクリロニトリル系重合体溶液をノズルより吐出する際に、溶解しなかったアクリロニトリル系重合体がノズル孔を閉塞、紡糸継続が困難となることを防止できる。また、加熱媒体の温度が１６０℃以下であれば、ポリマー鎖同士の架橋の進行が十分に抑制できたアクリロニトリル系重合体溶液となるため、ポリマー鎖同士の配位結合を切断に必要な熱保持を実施した後も、ポリマー鎖同士の架橋の進行が十分抑制できたアクリロニトリル系重合体溶液とすることが可能となる。炭素繊維前駆体アクリロニトリル系繊維製造工程での乾燥緻密化時の乾燥負荷をより低減するという観点と紡糸継続性の観点から、加熱媒体の温度を１００℃〜１５０℃とすることがより好ましく、１１０℃〜１４０℃とすることが更に好ましい。 The temperature of the heating medium for heating the mixed liquid in which the acrylonitrile polymer and the solvent are mixed is preferably 90 to 160 ° C. If the temperature of the heating medium is 90 ° C. or higher, the acrylonitrile-based polymer can be uniformly dissolved, and the amount of undissolved material is reduced. Therefore, when the acrylonitrile-based polymer solution is discharged from the nozzle, the acrylonitrile-based polymer that has not dissolved is dissolved. It is possible to prevent the polymer from blocking the nozzle hole and making spinning continued difficult. In addition, if the temperature of the heating medium is 160 ° C. or lower, it becomes an acrylonitrile-based polymer solution in which the progress of crosslinking between the polymer chains can be sufficiently suppressed, so that the heat retention necessary for cutting the coordination bond between the polymer chains is obtained. Even after carrying out the step, it is possible to obtain an acrylonitrile-based polymer solution in which the progress of crosslinking between polymer chains can be sufficiently suppressed. From the viewpoint of further reducing the drying load at the time of drying densification in the carbon fiber precursor acrylonitrile fiber manufacturing process and the viewpoint of spinning continuity, the temperature of the heating medium is more preferably 100 ° C. to 150 ° C., 110 It is still more preferable to set it as ° C-140 ° C.
溶剤は、アクリロニトリル系重合体の種類等を勘案して決定でき、例えば、ジメチルアセトアミド、ジメチルスルホキシド、ジメチルホルムアミド等の有機溶剤、塩化亜鉛、チオシアン酸ナトリウム等の無機化合物の水溶液が挙げられる。中でもジメチルアセトアミド、ジメチルスルホキシド、ジメチルホルムアミドが緻密な炭素繊維前駆体アクリロニトリル系繊維が得られる点で好ましい。 The solvent can be determined in consideration of the type of acrylonitrile polymer, and examples thereof include organic solvents such as dimethylacetamide, dimethylsulfoxide, and dimethylformamide, and aqueous solutions of inorganic compounds such as zinc chloride and sodium thiocyanate. Among them, dimethylacetamide, dimethylsulfoxide, and dimethylformamide are preferable in that a dense carbon fiber precursor acrylonitrile fiber can be obtained.
炭素繊維前駆体アクリロニトリル系繊維を得る方法としては、例えば、アクリロニトリル系重合体溶液をノズルより吐出し、直接凝固浴中に紡出して凝固させる湿式紡糸法、空気中で凝固させる乾式紡糸法、一旦、空気中に紡出した後、凝固浴中で凝固させる乾湿式紡糸法等、公知の紡糸方法が挙げられる。中でも、炭素繊維の強度及び弾性率をより向上させる観点から、湿式紡糸法又は乾湿式紡糸法が好ましい。 Examples of the method for obtaining the carbon fiber precursor acrylonitrile fiber include a wet spinning method in which an acrylonitrile polymer solution is discharged from a nozzle and directly spun into a coagulation bath to be coagulated, a dry spinning method in which coagulation is performed in air, Well-known spinning methods such as a dry and wet spinning method in which spinning in the air is followed by coagulation in a coagulation bath can be mentioned. Among these, from the viewpoint of further improving the strength and elastic modulus of the carbon fiber, the wet spinning method or the dry wet spinning method is preferable.
湿式紡糸法又は乾湿式紡糸法による紡糸賦形は、アクリロニトリル系重合体溶液を略円形断面の吐出孔を有するノズルより凝固浴中に紡出する方法が挙げられる。 Examples of the spinning shaping by the wet spinning method or the dry-wet spinning method include a method in which an acrylonitrile polymer solution is spun into a coagulation bath from a nozzle having a discharge hole having a substantially circular cross section.
本発明では、アクリロニトリル系重合体溶液を熱保持した後、ノズルより吐出して凝固浴に浸漬させて凝固糸とし、その凝固糸を洗浄、延伸、乾燥緻密化させることで炭素繊維前駆体アクリル系繊維を得る。 In the present invention, after the acrylonitrile-based polymer solution is heated and held, it is discharged from a nozzle and immersed in a coagulation bath to form a coagulated yarn, and the coagulated yarn is washed, drawn, and dried and densified to obtain a carbon fiber precursor acrylic type. Get fiber.
アクリロニトリル系重合体はアクリロニトリルを主成分としたポリマー鎖の集合体である。アクリロニトリル系重合体溶液中のポリマー鎖は、アクリロニトリル系重合体溶液を熱保持することで、金属イオンなどを介したポリマー鎖同士の配位結合切断や化学結合を起点としたポリマー鎖同士の架橋が進行する。ポリマー鎖同士の配位結合や架橋が過剰に発生した場合、アクリロニトリル系重合体溶液中の斑が増加するため、凝固不均一を引き起こし、得られる凝固糸も不均一となるため、空孔率が増加し、含水率も上がってしまうものと考えられる。本発明者らはアクリロニトリル系重合体溶液を熱保持する条件を制御することにより、ポリマー鎖同士の配位結合や架橋が過剰に進行することを抑制し、結果的に凝固糸中の含水率を低下させ、炭素繊維前駆体アクリロニトリル系繊維製造工程での乾燥緻密化時の乾燥負荷を低減できることを見出した。 An acrylonitrile-based polymer is an assembly of polymer chains mainly composed of acrylonitrile. The polymer chains in the acrylonitrile-based polymer solution can retain the acrylonitrile-based polymer solution with heat, and the polymer chains can be cross-linked from each other by the coordinate bond breakage or chemical bond between the polymer chains via metal ions. proceed. When excessive coordination or cross-linking between polymer chains occurs, the spots in the acrylonitrile polymer solution increase, causing coagulation nonuniformity and the resulting coagulated yarn also becomes nonuniform. It is thought that the water content increases as well. The inventors of the present invention control the conditions for heat retention of the acrylonitrile-based polymer solution, thereby preventing excessive coordination and cross-linking of polymer chains, resulting in the moisture content in the coagulated yarn. It was found that the drying load at the time of drying densification in the carbon fiber precursor acrylonitrile fiber manufacturing process can be reduced.
本発明では、前述した溶解装置の排出口より排出されたアクリロニトリル系重合体溶液を排出した時点から５分以内に、３０〜８５℃の範囲に温度調整し、その直後からノズル孔より吐出するまで温度３０℃〜８５℃にて熱保持することが好ましい。 In the present invention, the temperature is adjusted to a range of 30 to 85 ° C. within 5 minutes from the time when the acrylonitrile-based polymer solution discharged from the discharge port of the above-described dissolution apparatus is discharged, and immediately after that, the liquid is discharged from the nozzle hole. It is preferable to heat-hold at a temperature of 30 ° C to 85 ° C.
溶解装置の排出口より排出された直後のアクリロニトリル系重合体溶液温度を５分以内に３０℃以上とすることで、配位結合の再形成を抑制することが可能となり、結果的に凝固糸中の含水率を低下させ、乾燥緻密化時の乾燥負荷を低減できる。溶解装置の排出口より排出された直後のアクリロニトリル系重合体溶液の温度を５分以内に８５℃以下とすることでポリマー鎖同士の架橋の進行を十分に抑制可能となり、ポリマー鎖同士の架橋進行に伴う流動性低下を抑制できるだけでなく、凝固糸中の含水率を低下させ、乾燥緻密化時の乾燥負荷を低減することが可能となる。炭素繊維前駆体アクリロニトリル系繊維製造工程での乾燥緻密化時の乾燥負荷をより低減するという観点から、溶解装置の排出口より排出された直後のアクリロニトリル系重合体溶液温度を５分以内に温度３５℃〜８０℃に温度調整することがより好ましく、４５℃〜７５℃に温度調整することが更に好ましい。 By setting the temperature of the acrylonitrile polymer solution immediately after being discharged from the discharge port of the dissolving apparatus to 30 ° C. or more within 5 minutes, it becomes possible to suppress the re-formation of coordination bonds, and as a result, in the coagulated yarn It is possible to reduce the moisture content of the water and to reduce the drying load during drying and densification. By making the temperature of the acrylonitrile-based polymer solution immediately after being discharged from the discharge port of the dissolution apparatus 85 ° C. or less within 5 minutes, it is possible to sufficiently suppress the progress of crosslinking between the polymer chains, and the crosslinking progresses between the polymer chains. It is possible not only to suppress a decrease in fluidity due to, but also to reduce the moisture content in the coagulated yarn and reduce the drying load during drying densification. From the viewpoint of further reducing the drying load during drying and densification in the carbon fiber precursor acrylonitrile fiber manufacturing process, the temperature of the acrylonitrile polymer solution immediately after being discharged from the discharge port of the dissolving apparatus is within 35 minutes. It is more preferable to adjust the temperature to -80 ° C, and it is even more preferable to adjust the temperature to 45 ° C to 75 ° C.
温度調整直後からノズル孔より吐出するまでのアクリロニトリル系重合体溶液の熱保持を３０℃以上とすることで、ポリマー鎖同士の配位結合を十分切断でき、配位結合の再形成も抑制することが可能となり、結果的に凝固糸中の含水率を低下させ、乾燥緻密化時の乾燥負荷を低減できる。また、アクリロニトリル系重合体溶液の流動性を容易に保つことができ、炭素繊維前駆体アクリロニトリル系繊維を製造する際に、安定してノズル孔よりアクリロニトリル系重合体溶液を吐出することが可能となる。温度調整直後からノズル孔より吐出するまでのアクリロニトリル系重合体溶液の８５℃以下とすることでポリマー鎖同士の架橋の進行を十分に抑制可能となり、ポリマー鎖同士の架橋進行に伴う流動性低下を抑制できるだけでなく、凝固糸中の含水率を低下させ、乾燥緻密化時の乾燥負荷を低減することが可能となる。炭素繊維前駆体アクリロニトリル系繊維製造工程での乾燥緻密化時の乾燥負荷をより低減するという観点から、温度調整直後からノズル孔より吐出するまでのアクリロニトリル系重合体溶液をノズル孔より吐出するまで温度３５℃〜８０℃で熱保持することがより好ましく、４５℃〜７５℃で熱保持することが更に好ましい。 The heat retention of the acrylonitrile-based polymer solution from immediately after the temperature adjustment to the discharge from the nozzle hole is set to 30 ° C. or higher, so that the coordination bond between the polymer chains can be sufficiently cut and the re-formation of the coordination bond can be suppressed. As a result, the moisture content in the coagulated yarn can be reduced, and the drying load during drying and densification can be reduced. In addition, the fluidity of the acrylonitrile polymer solution can be easily maintained, and when the carbon fiber precursor acrylonitrile fiber is produced, the acrylonitrile polymer solution can be stably discharged from the nozzle hole. . By making the acrylonitrile-based polymer solution 85 ° C. or less immediately after temperature adjustment until it is discharged from the nozzle hole, it is possible to sufficiently suppress the progress of cross-linking of polymer chains, and decrease the fluidity accompanying the progress of cross-linking of polymer chains. Not only can it be suppressed, but the moisture content in the coagulated yarn can be reduced, and the drying load during drying and densification can be reduced. From the viewpoint of further reducing the drying load at the time of densification in the carbon fiber precursor acrylonitrile fiber manufacturing process, the temperature until the acrylonitrile polymer solution is discharged from the nozzle hole immediately after the temperature adjustment until it is discharged from the nozzle hole. It is more preferable to heat-hold at 35 to 80 degreeC, and it is still more preferable to heat-hold at 45 to 75 degreeC.
また、上述したアクリロニトリル系重合体溶液の、前述した溶解装置の排出口からノズル孔までの通過時間を、０．５時間〜２０時間とすることが好ましい。通過時間を０．５時間以上とすることで、ポリマー鎖同士の配位結合を十分切断するための熱保持が可能となり、結果的に凝固糸中の含水率を低下させ、乾燥緻密化時の乾燥負荷を低減することが可能となる。また、通過時間を２０時間以下とすることでポリマー鎖同士の架橋の進行を十分に抑制可能な熱保持を実施することができ、結果的に凝固糸中の含水率を低下させ、乾燥緻密化時の乾燥負荷を低減できる。炭素繊維前駆体アクリロニトリル系繊維製造工程での乾燥緻密化時の乾燥負荷をより低減するという観点から、上述したアクリロニトリル系重合体溶液の、前述した溶解装置の排出口からノズル孔までの通過時間を、１．５時間〜１０時間とすることがより好ましく、２．５時間〜５．５時間とすることが更に好ましい。 Moreover, it is preferable that the passage time from the discharge port of the dissolution apparatus described above to the nozzle hole of the acrylonitrile-based polymer solution is 0.5 hours to 20 hours. By setting the passage time to 0.5 hours or longer, heat retention for sufficiently breaking the coordinate bond between the polymer chains becomes possible, and as a result, the moisture content in the coagulated yarn is reduced, and the dry densification It becomes possible to reduce a drying load. In addition, by setting the passage time to 20 hours or less, it is possible to carry out heat retention that can sufficiently suppress the progress of cross-linking of polymer chains, resulting in a decrease in the moisture content in the coagulated yarn, resulting in dry densification The drying load at the time can be reduced. From the viewpoint of further reducing the drying load at the time of densification in the carbon fiber precursor acrylonitrile fiber manufacturing process, the passing time from the discharge port of the dissolving device to the nozzle hole of the acrylonitrile polymer solution described above is determined. , 1.5 hours to 10 hours is more preferable, and 2.5 hours to 5.5 hours is further preferable.
なお、本発明での熱保持は、アクリロニトリル系重合体溶液をタンク内にて静置熱保持することで実施してもよく、また、アクリロニトリル系重合体溶液をノズルへ送液している最中に熱保持を実施してもよい。 The heat retention in the present invention may be carried out by holding the acrylonitrile polymer solution in a tank while still standing, and during the feeding of the acrylonitrile polymer solution to the nozzle. Heat holding may be performed.
本発明では、下記測定方法により得られる、前述した溶解装置の排出口より排出された直後のアクリロニトリル系重合体溶液の吸光度Ａが０．０３０以上０．１６０以下であることが好ましい。アクリロニトリル系重合体溶液の吸光度Ａは、例えばアクリロニトリル系重合体と溶剤を混合した混合液を加熱する加熱媒体の温度により調整することができる。また、溶液重合によりアクリロニトリル系重合体溶液を得る際は、重合反応時の反応温度により調整することができる。溶解装置から排出された直後のアクリロニトリル系重合体溶液の吸光度Ａを０．０３０以上であれば、アクリロニトリル系重合体溶液中の溶解が十分進んでおり、アクリロニトリル系重合体溶液をノズルより吐出する際に、溶解しなかったアクリロニトリル系重合体がノズル孔を閉塞、紡糸継続が困難となることを防止できる。また、溶解装置から排出された直後のアクリロニトリル系重合体溶液の吸光度Ａを０．１６０以下であれば、ポリマー鎖同士の架橋の進行が十分に抑制できたアクリロニトリル系重合体溶液となるため、ポリマー鎖同士の配位結合を切断に必要な熱保持を実施した後も、ポリマー鎖同士の架橋の進行が十分抑制できたアクリロニトリル系重合体溶液とすることが可能となる。炭素繊維前駆体アクリロニトリル系繊維製造工程での乾燥緻密化時の乾燥負荷をより低減するという観点と紡糸継続性の観点から、アクリロニトリル系重合体を溶剤と混合、溶解装置を通して溶解、装置から排出された直後のアクリロニトリル系重合体溶液の吸光度Ａを０．０５０以上０．１５０以下であることがより好ましく、０．０７０以上０．１３０以下であることが更に好ましい。 In the present invention, it is preferable that the absorbance A of the acrylonitrile-based polymer solution immediately after being discharged from the outlet of the dissolution apparatus described above obtained by the following measurement method is 0.030 or more and 0.160 or less. The absorbance A of the acrylonitrile-based polymer solution can be adjusted by, for example, the temperature of a heating medium that heats a mixed liquid obtained by mixing an acrylonitrile-based polymer and a solvent. Moreover, when obtaining an acrylonitrile-type polymer solution by solution polymerization, it can adjust with the reaction temperature at the time of a polymerization reaction. If the absorbance A of the acrylonitrile-based polymer solution immediately after being discharged from the dissolution apparatus is 0.030 or more, the dissolution in the acrylonitrile-based polymer solution is sufficiently advanced, and when the acrylonitrile-based polymer solution is discharged from the nozzle In addition, it is possible to prevent the acrylonitrile-based polymer that has not been dissolved from blocking the nozzle hole and making spinning difficult. Further, if the absorbance A of the acrylonitrile polymer solution immediately after being discharged from the dissolution apparatus is 0.160 or less, the acrylonitrile polymer solution in which the progress of crosslinking between the polymer chains can be sufficiently suppressed is obtained. Even after carrying out the heat retention necessary for breaking the coordination bond between the chains, it is possible to obtain an acrylonitrile-based polymer solution in which the progress of crosslinking between the polymer chains can be sufficiently suppressed. From the viewpoint of further reducing the drying load at the time of densification in the carbon fiber precursor acrylonitrile fiber manufacturing process and from the viewpoint of spinning continuity, the acrylonitrile polymer is mixed with a solvent, dissolved through a dissolving device, and discharged from the device. The absorbance A of the acrylonitrile-based polymer solution immediately after is more preferably 0.050 or more and 0.150 or less, and further preferably 0.070 or more and 0.130 or less.
アクリロニトリル系重合体溶液の吸光度測定方法
アクリロニトリル系重合体溶液を溶液と同じ溶媒にて質量換算で２０倍に希釈し、厚さ１ｃｍのセルに入れ、波長３５０ｎｍにおける吸光度Ｘを測定する。また、溶媒のみを厚さ１ｃｍのセルに入れ、波長３５０ｎｍにおける吸光度Ｙを測定する。Ｘ−Ｙをアクリロニトリル系重合体溶液の吸光度とする。吸光度測定時の温度は３０℃とする。
Method for measuring absorbance of acrylonitrile-based polymer solution The acrylonitrile-based polymer solution is diluted 20-fold in terms of mass in the same solvent as the solution, placed in a cell having a thickness of 1 cm, and absorbance X at a wavelength of 350 nm is measured. Further, only the solvent is put into a cell having a thickness of 1 cm, and the absorbance Y at a wavelength of 350 nm is measured. Let XY be the absorbance of the acrylonitrile-based polymer solution. The temperature during the absorbance measurement is 30 ° C.
本発明では、ノズル吐出直後のアクリロニトリル系重合体溶液の吸光度Ｂが０．１６５以下であることが好ましい。ノズル吐出直後のアクリロニトリル系重合体溶液の吸光度を０．１６５以下とすることで、ポリマー鎖同士の架橋の進行が十分に抑制できたアクリロニトリル系重合体溶液となり、得られる凝固糸中の含水率を低下させ、乾燥緻密化時の乾燥負荷を低減させることが可能となる。炭素繊維前駆体アクリロニトリル系繊維製造工程での乾燥緻密化時の乾燥負荷をより低減するという観点から、ノズル吐出直後のアクリロニトリル系重合体溶液の吸光度Ｂを０．１６０以下とすることがより好ましく、０．１４０以下とすることが更に好ましい。 In the present invention, it is preferable that the absorbance B of the acrylonitrile-based polymer solution immediately after nozzle discharge is 0.165 or less. By setting the absorbance of the acrylonitrile polymer solution immediately after nozzle discharge to 0.165 or less, it becomes an acrylonitrile polymer solution in which the progress of crosslinking between the polymer chains can be sufficiently suppressed, and the water content in the obtained coagulated yarn is increased. It becomes possible to reduce and to reduce the drying load at the time of dry densification. From the viewpoint of further reducing the drying load during drying densification in the carbon fiber precursor acrylonitrile fiber manufacturing process, it is more preferable that the absorbance B of the acrylonitrile polymer solution immediately after nozzle discharge is 0.160 or less, More preferably, it is 0.140 or less.
本発明では、前記吸光度Ａと前記吸光度Ｂの比であるＢ／Ａが１．０５０以上１．３５０以下であることが好ましい。Ｂ／Ａを１．０３０以上であれば、ポリマー鎖同士の配位結合を十分切断できていることとなり、結果的に凝固糸中の含水率を低下させ、乾燥緻密化時の乾燥負荷を低減することが可能となる。また、Ｂ／Ａを１．３５０以下であれば、ポリマー鎖同士の架橋の進行が十分に抑制できるため、得られる凝固糸中の含水率を低下させ、乾燥緻密化時の乾燥負荷を低減させることが可能となる。炭素繊維前駆体アクリロニトリル系繊維製造工程での乾燥緻密化時の乾燥負荷をより低減するという観点から、Ｂ／Ａを１．０５５以上１．２５０以下とすることがより好ましく、Ｂ／Ａを１．０８０以上１．１８０以下とすることが更に好ましい。 In the present invention, B / A, which is a ratio of the absorbance A and the absorbance B, is preferably 1.050 or more and 1.350 or less. If B / A is 1.030 or more, the coordination bond between the polymer chains can be sufficiently cut, and as a result, the moisture content in the coagulated yarn is reduced, and the drying load during drying densification is reduced. It becomes possible to do. Moreover, if B / A is 1.350 or less, the progress of cross-linking between polymer chains can be sufficiently suppressed, so that the moisture content in the obtained coagulated yarn is reduced, and the drying load during drying densification is reduced. It becomes possible. From the viewpoint of further reducing the drying load at the time of drying densification in the carbon fiber precursor acrylonitrile fiber production process, B / A is more preferably 1.055 or more and 1.250 or less, and B / A is 1 More preferably, it is set to 0.080 or more and 1.180 or less.
凝固浴としては、アクリロニトリル系重合体溶液に用いられる溶剤を含む水溶液を用いることが好ましい。このような凝固浴が、溶剤回収の容易性の観点から好ましい。 As the coagulation bath, it is preferable to use an aqueous solution containing a solvent used for an acrylonitrile-based polymer solution. Such a coagulation bath is preferable from the viewpoint of easy solvent recovery.
凝固浴として溶剤を含む水溶液を用いる場合、該水溶液中の溶剤濃度は、３０〜９０質量％であることが好ましく、４０〜８５質量％であることがより好ましい。この範囲内であれば、炭素繊維前駆体アクリロニトリル系繊維をボイドの発生がない緻密な構造とすることができ、高強度、高弾性率の炭素繊維が得られる。加えて、延伸性が確保でき生産性にも優れる。 When using the aqueous solution containing a solvent as a coagulation bath, it is preferable that the solvent concentration in this aqueous solution is 30-90 mass%, and it is more preferable that it is 40-85 mass%. Within this range, the carbon fiber precursor acrylonitrile fiber can be made into a dense structure free from voids, and a carbon fiber having high strength and high elastic modulus can be obtained. In addition, stretchability can be secured and productivity is excellent.
凝固浴温度の低温化に伴い、凝固糸の含水率は低下するものの、凝固浴中にて凝固糸同士が接着しやすくなるため、炭素繊維前駆体アクリロニトリル系繊維製造工程中にて糸切れなどのトラブルを発生させてしまう。従って、凝固浴の温度は０〜４０℃が好ましい。 As the coagulation bath temperature decreases, the moisture content of the coagulated yarn decreases, but it becomes easier for the coagulated yarns to adhere to each other in the coagulation bath, so that during the production process of the carbon fiber precursor acrylonitrile fiber, It will cause trouble. Therefore, the temperature of the coagulation bath is preferably 0 to 40 ° C.
紡糸工程では、凝固糸を凝固浴中又は延伸浴中で延伸することができる。或いは、凝固糸を空中で延伸した後、再度、浴中で延伸することができる。更にまた、延伸の前後又は延伸中に水洗し、凝固糸を水膨潤状態とすることができる。延伸浴は、例えば、水、又はアクリロニトリル系重合体溶液に用いられる溶剤を含む水溶液等が挙げられる。 In the spinning process, the coagulated yarn can be drawn in a coagulation bath or a drawing bath. Alternatively, after the coagulated yarn is drawn in the air, it can be drawn again in a bath. Furthermore, the coagulated yarn can be made into a water-swollen state by washing with water before or after stretching or during stretching. Examples of the stretching bath include water or an aqueous solution containing a solvent used for an acrylonitrile-based polymer solution.
延伸は、凝固浴又は延伸浴に凝固糸を入れ、凝固糸に張力を掛けることで行われる。延伸は、例えば、１回で所望の倍率としてもよいし、２回以上に分けて多段に延伸することで所望の倍率としてもよい。例えば、空中での延伸と延伸浴中での延伸を組み合わせ、合計で５〜１５倍に延伸することとよい。このように凝固糸を延伸して延伸糸とすることで、炭素繊維の高強度化、高弾性率が図れる。 Drawing is performed by putting a coagulated yarn in a coagulation bath or a drawing bath and applying tension to the coagulated yarn. For example, the stretching may be performed at a desired ratio once, or may be performed at a desired ratio by stretching in two or more stages. For example, stretching in the air and stretching in the stretching bath may be combined, and the stretching may be performed 5 to 15 times in total. By stretching the coagulated yarn in this way to obtain a drawn yarn, the carbon fiber can be increased in strength and elastic modulus.
油剤組成物の炭素繊維前駆体アクリロニトリル系繊維への付与は、前述の浴中延伸後の延伸糸に油剤組成物の分散液を付与することにより行うことができる。浴中延伸の後に洗浄を行う場合は、浴中延伸及び洗浄を行った後に得られる延伸糸に油剤分散液を付与することもできる。 Application of the oil composition to the carbon fiber precursor acrylonitrile fiber can be performed by applying a dispersion of the oil composition to the drawn yarn after drawing in the bath. When washing is performed after drawing in the bath, an oil dispersion can be applied to the drawn yarn obtained after drawing and washing in the bath.
油剤組成物は、炭素繊維前駆体アクリロニトリル系繊維に求める機能等を勘案して決定でき、例えば、シリコーン系油剤組成物が好ましく、必要に応じて、さらに酸化防止剤、帯電防止剤、消泡剤、防腐剤、抗菌剤、浸透剤等の添加物を配合することができる。油剤組成物を延伸糸に含浸する方法としては、ローラー法、ガイド法、スプレー法、ディップ法等、公知の方法を用いることができる。油剤組成物が付着した凝固糸は、続いて乾燥緻密化される。 The oil composition can be determined in consideration of the functions required for the carbon fiber precursor acrylonitrile fiber, for example, a silicone oil composition is preferable, and if necessary, an antioxidant, an antistatic agent, and an antifoaming agent. Additives such as preservatives, antibacterial agents and penetrants can be blended. As a method for impregnating the stretched yarn with the oil agent composition, a known method such as a roller method, a guide method, a spray method, or a dip method can be used. The coagulated yarn to which the oil composition is adhered is subsequently dried and densified.
乾燥工程は、従来公知の方法で延伸糸を乾燥でき、例えば、加熱ローラーによる乾燥が好ましい乾燥方法として挙げられる。なお、加熱ローラーの数量は１個であっても２個以上であってもよい。 A drying process can dry a drawn yarn by a conventionally well-known method, for example, drying with a heating roller is mentioned as a preferable drying method. Note that the number of heating rollers may be one or two or more.
乾燥工程における乾燥温度は、延伸糸のガラス転移温度を超えた温度とすることが好ましい。このような乾燥温度で処理することで、凝固糸の乾燥と緻密化が達成できる。乾燥温度は延伸糸の含水量の変動により異なるが、例えば、１００〜２００℃の範囲で決定することが好ましい。延伸糸の含水率は凝固糸の含水率に影響するため、凝固糸の含水率が低いほど延伸糸の含水率も低下し、結果的に乾燥工程における延伸糸の乾燥処理コストを低減できる。 The drying temperature in the drying step is preferably a temperature exceeding the glass transition temperature of the drawn yarn. By processing at such a drying temperature, drying and densification of the coagulated yarn can be achieved. Although drying temperature changes with fluctuation | variations of the moisture content of a drawn yarn, it is preferable to determine in the range of 100-200 degreeC, for example. Since the moisture content of the drawn yarn affects the moisture content of the coagulated yarn, the lower the moisture content of the coagulated yarn, the lower the moisture content of the drawn yarn. As a result, the cost for drying the drawn yarn in the drying process can be reduced.
延伸糸は乾燥後、加熱延伸を行うことが、得られる炭素繊維前駆体アクリロニトリル系繊維の緻密性や配向度をさらに高めることができることから好ましい。加熱延伸の方法には、加熱ローラーで搬送させながら延伸する方法や加圧水蒸気圧雰囲気下で延伸する方法がある。
加熱延伸後、炭素繊維前駆体アクリロニトリル系繊維は、室温のロール等を通すことにより、常温の状態まで冷却する。冷却した炭素繊維前駆体アクリロニトリル系繊維は、ワインダーでボビンに巻き取られ、或いはケンスに振込まれて収納され、炭素繊維の製造に供される。
It is preferable to heat-draw the drawn yarn after drying because the denseness and degree of orientation of the resulting carbon fiber precursor acrylonitrile fiber can be further increased. Examples of the heat stretching method include a method of stretching while being conveyed by a heating roller and a method of stretching in a pressurized water vapor pressure atmosphere.
After the heat stretching, the carbon fiber precursor acrylonitrile fiber is cooled to a normal temperature state by passing a roll at room temperature. The cooled carbon fiber precursor acrylonitrile fiber is wound around a bobbin by a winder, or transferred into a can and stored for use in the production of carbon fiber.
上述した方法により、凝固浴温度を低下させることなく凝固糸の含水率を減らすことが可能となるため、凝固糸同士の接着を発生させることなく、乾燥緻密化時の乾燥負荷を下げることができ、結果的に炭素繊維前駆体アクリロニトリル系繊維の低コスト化が可能となる。 The above-described method makes it possible to reduce the moisture content of the coagulated yarn without lowering the coagulation bath temperature, so that the drying load during drying densification can be reduced without causing adhesion between coagulated yarns. As a result, the cost of the carbon fiber precursor acrylonitrile fiber can be reduced.
以下、本発明について実施例を挙げて具体的に説明するが、本発明はこれらに限定されるものではない。 EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not limited to these.
［凝固糸含水率］
アクリロニトリル系重合体溶液をノズル孔より吐出、凝固浴に浸漬して、凝固浴から引き上げて得られた凝固糸を約２０ｇ採取し、卓上遠心機(社製、型番：)にて３０００ｒｐｍで１０分間遠心脱水し、その質量Ｘを測定する。その後、凝固糸を３０℃の流水で５時間洗浄し、１０５℃に保温した乾燥機に入れて３時間乾燥する。乾燥し終えた凝固糸の質量Ｙを測定する。得られた数値と下記の式を用いて凝固糸含水率を求める。
凝固糸含水率＝（Ｘ−Ｙ／Ｙ）×１００
[Water content of coagulated yarn]
About 20 g of the coagulated yarn obtained by discharging the acrylonitrile-based polymer solution from the nozzle hole and dipping in the coagulation bath and pulling it up from the coagulation bath is collected for 10 minutes at 3000 rpm with a tabletop centrifuge (manufactured by Co., Ltd., model number :). Centrifugal dehydration and the mass X is measured. Thereafter, the coagulated yarn is washed with running water at 30 ° C. for 5 hours, and then dried in a drier kept at 105 ° C. for 3 hours. The mass Y of the solidified yarn that has been dried is measured. The moisture content of the coagulated yarn is determined using the obtained numerical value and the following formula.
Coagulated yarn moisture content = (X−Y / Y) × 100
［吸光度］
アクリロニトリル系重合体溶液を、アクリロニトリル系重合体溶液と同じ溶媒で、３０℃にて、質量換算で２０倍に希釈し、厚さ１ｃｍのセルに入れ、日立分光光度計（型番：Ｕ―３３００）を用いて波長３５０ｎｍにおける吸光度Ｍを測定する。
溶媒のみを厚さ１ｃｍのセルに入れ、日立分光光度計（型番：Ｕ―３３００）を用いて波長３５０ｎｍにおける吸光度Ｎを測定する。
Ｍ−Ｎをアクリロニトリル系重合体溶液の吸光度とする。
[Absorbance]
The acrylonitrile-based polymer solution is diluted 20 times in mass conversion at 30 ° C. with the same solvent as the acrylonitrile-based polymer solution, and placed in a 1 cm-thick cell. Hitachi spectrophotometer (model number: U-3300) Is used to measure the absorbance M at a wavelength of 350 nm.
Only the solvent is put into a cell having a thickness of 1 cm, and the absorbance N at a wavelength of 350 nm is measured using a Hitachi spectrophotometer (model number: U-3300).
MN is the absorbance of the acrylonitrile-based polymer solution.
（実施例１）
［アクリロニトリル系重合体の製造］
アクリロニトリル系重合体は、オーバーフロー式の重合容器に、以下のように各原料を供給すると共に重合容器内の温度を５０℃に維持しながら攪拌し、オーバーフローした重合体スラリーを洗浄、乾燥して製造した。重合容器内には、脱イオン水８２．７５質量％と、モノマー１７質量％（モノマー組成比は、アクリロニトリル（ＡＮ）単量体単位：メタクリル酸（ＭＡＡ）単量体単位（質量比）＝９８：２）と、過硫酸アンモニウム０．１質量％と、亜硫酸水素アンモニウム０．１５質量％と、硫酸第一鉄７水和物２質量ｐｐｍとを、それぞれ連続して供給すると共に、ｐＨ３．０となるように硫酸を適量添加した。得られたアクリロニトリル系重合体の組成は、ＡＮ単量体単位：ＭＡＡ単量体単位（質量比）＝９８：２であった。
Example 1
[Production of acrylonitrile polymer]
Acrylonitrile polymer is produced by supplying each raw material to an overflow type polymerization vessel as follows and stirring while maintaining the temperature in the polymerization vessel at 50 ° C., washing and drying the overflowed polymer slurry. did. In the polymerization vessel, 82.75% by mass of deionized water and 17% by mass of monomer (monomer composition ratio is acrylonitrile (AN) monomer unit: methacrylic acid (MAA) monomer unit (mass ratio)) = 98. : 2), 0.1% by mass of ammonium persulfate, 0.15% by mass of ammonium bisulfite, and 2 ppm by mass of ferrous sulfate heptahydrate, respectively, and continuously with pH 3.0 An appropriate amount of sulfuric acid was added so that The composition of the obtained acrylonitrile-based polymer was AN monomer unit: MAA monomer unit (mass ratio) = 98: 2.
［炭素繊維前駆体アクリロニトリル系繊維の製造］
上記で得たアクリロニトリル系重合体２３質量％と、１０℃のジメチルホルムアミド７７質量％を混合して混合液とし、溶解装置に通してアクリロニトリル系重合体溶液を得た。
溶解装置はシェル側に１２０℃のシリコンオイルを循環した、内径１３ｍｍのシェルアンドチューブ式二重管から成っている。また、溶解装置の排出口直後にシェル側に４５℃の温水を循環した内径１３ｍｍのシェルアンドチューブ式二重管（以下温度調整エリアと記載する）を設置した。まず溶解装置のチューブ側に、平均滞在時間が１０分間となるよう混合液を連続的に供給、加熱溶解して溶解装置より排出し、アクリロニトリル系重合体溶液を得た。その後、温度調整エリアのチューブ側に、平均滞在時間が３分間となるよう続けて連続的に供給し、温度調整エリア排出直後のアクリロニトリル系重合体溶液の温度が５０℃となるよう調整した。
[Production of carbon fiber precursor acrylonitrile fiber]
23% by mass of the acrylonitrile polymer obtained above and 77% by mass of dimethylformamide at 10 ° C. were mixed to obtain a mixed solution, which was passed through a dissolving apparatus to obtain an acrylonitrile polymer solution.
The melting apparatus consists of a shell-and-tube double tube having an inner diameter of 13 mm and circulating silicone oil at 120 ° C. on the shell side. In addition, a shell and tube double tube (hereinafter referred to as a temperature adjustment area) having an inner diameter of 13 mm in which hot water of 45 ° C. was circulated on the shell side immediately after the discharge port of the dissolution apparatus. First, the mixed solution was continuously supplied to the tube side of the dissolution apparatus so that the average residence time was 10 minutes, dissolved by heating, and discharged from the dissolution apparatus to obtain an acrylonitrile-based polymer solution. Thereafter, the tube was continuously supplied to the tube side of the temperature adjustment area so that the average residence time was 3 minutes, and the temperature of the acrylonitrile-based polymer solution immediately after discharging the temperature adjustment area was adjusted to 50 ° C.
溶解装置排出直後のアクリロニトリル系重合体溶液の吸光度Ａは表１に示したとおりであった。このアクリロニトリル系重合体溶液を温度調整エリア排出直後からノズルより吐出するまで５０℃に熱保持しつつ、溶解装置の排出口からノズル吐出までのアクリロニトリル系重合体溶液の通過時間が５時間となるように調整した。 The absorbance A of the acrylonitrile-based polymer solution immediately after discharging the dissolution apparatus was as shown in Table 1. While this acrylonitrile-based polymer solution is kept at 50 ° C. immediately after discharge from the temperature adjustment area until it is discharged from the nozzle, the passage time of the acrylonitrile-based polymer solution from the discharge port of the dissolving apparatus to the nozzle discharge is 5 hours. Adjusted.
アクリロニトリル系重合体溶液は孔径１５０μｍ、ホール数２０００のノズルより一旦空気中に吐出し、約４ｍｍの空間を通過させた後、濃度８０質量％、温度１０℃のジメチルホルムアミド水溶液からなる凝固浴中に浸け、凝固糸を得た。ノズル吐出直後のアクリロニトリル系重合体溶液の吸光度Ｂ及び得られた凝固糸の凝固糸含水率は表１に示した通りであった。得られた凝固糸を空気中で１．１倍に延伸し、続いて濃度５０質量％、温度６０℃のジメチルホルムアミド水溶液中で３．０倍に延伸し、熱水中で１．１倍に延伸しながら洗浄、脱溶剤を行った。脱溶剤した凝固糸をアミノ変性シリコーン系油剤分散液中に浸漬し、１４０℃の加熱ローラーで緻密乾燥化した。このとき使用したアミノ変性シリコーン系油剤分散液は、アミノ変性シリコーン（信越化学工業株式会社製、商品名：ＫＦ−８００２）９０質量部に対し、乳化剤（花王株式会社製、商品名：エマルゲン１０８）を１０質量部混合したものをゴーリンミキサー（エスエムテー株式会社製、商品名：圧力式ホモジナイザーゴーリンタイプ）で乳化した後、水を加えて製造したもので、得られた油剤分散液の組成は、水：アミノ変性シリコーン：乳化剤（質量比）＝９８．６５：１．２：０．１５であった。次いで、表面温度１９０℃の熱ロールにて３．０倍に延伸し、捲取速度２５０ｍ／分にて単繊維繊度０．７ｄｔｅｘの炭素繊維前駆体繊維を製造した。 The acrylonitrile-based polymer solution is once discharged into the air from a nozzle having a pore diameter of 150 μm and a hole number of 2000, passed through a space of about 4 mm, and then placed in a coagulation bath comprising a dimethylformamide aqueous solution having a concentration of 80 mass% and a temperature of 10 ° C. Soaked to obtain a coagulated yarn. Table 1 shows the absorbance B of the acrylonitrile-based polymer solution immediately after nozzle discharge and the moisture content of the obtained coagulated yarn. The obtained coagulated yarn was stretched 1.1 times in air, then stretched 3.0 times in a dimethylformamide aqueous solution having a concentration of 50% by mass and a temperature of 60 ° C., and 1.1 times in hot water. Washing and solvent removal were performed while stretching. The solvent-removed coagulated yarn was immersed in an amino-modified silicone oil dispersion and densely dried with a heating roller at 140 ° C. The amino-modified silicone oil dispersion used at this time was 90 parts by mass of amino-modified silicone (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KF-8002), and an emulsifier (trade name: Emulgen 108, manufactured by Kao Corporation). 10 parts by mass of the mixture was emulsified with a Gorin mixer (manufactured by SMT Co., Ltd., trade name: pressure homogenizer gorin type) and then added with water, and the composition of the resulting oil dispersion was water. : Amino-modified silicone: Emulsifier (mass ratio) = 98.65: 1.2: 0.15. Subsequently, it was stretched 3.0 times with a hot roll having a surface temperature of 190 ° C., and a carbon fiber precursor fiber having a single fiber fineness of 0.7 dtex was produced at a winding speed of 250 m / min.
（実施例２）
溶解装置の排出口からノズル吐出までのアクリロニトリル系重合体溶液の通過時間が３時間となるよう調整した以外は実施例１と同様に実施した。
このときの溶解装置排出直後のアクリロニトリル系重合体溶液の吸光度Ａ、ノズル吐出直後のアクリロニトリル系重合体溶液の吸光度Ｂ、凝固糸の凝固糸含水率は表１に示した通りであった。
(Example 2)
The same procedure as in Example 1 was performed except that the passage time of the acrylonitrile-based polymer solution from the discharge port of the dissolution apparatus to the nozzle discharge was adjusted to 3 hours.
At this time, the absorbance A of the acrylonitrile-based polymer solution immediately after discharging of the dissolving apparatus, the absorbance B of the acrylonitrile-based polymer solution immediately after discharging the nozzle, and the moisture content of the coagulated yarn of the coagulated yarn were as shown in Table 1.
（実施例３）
溶解装置の排出口からノズル吐出までのアクリロニトリル系重合体溶液の通過時間が２時間となるよう調整した以外は実施例１と同様に実施した。
このときの溶解装置排出直後のアクリロニトリル系重合体溶液の吸光度Ａ、ノズル吐出直後のアクリロニトリル系重合体溶液の吸光度Ｂ、凝固糸の凝固糸含水率は表１に示した通りであった。
(Example 3)
The same procedure as in Example 1 was performed except that the passage time of the acrylonitrile-based polymer solution from the discharge port of the dissolution apparatus to the nozzle discharge was adjusted to 2 hours.
At this time, the absorbance A of the acrylonitrile-based polymer solution immediately after discharging of the dissolving apparatus, the absorbance B of the acrylonitrile-based polymer solution immediately after discharging the nozzle, and the moisture content of the coagulated yarn of the coagulated yarn were as shown in Table 1.
（実施例４）
溶解装置の排出口からノズル吐出までのアクリロニトリル系重合体溶液の通過時間が１０時間となるよう調整した以外は実施例１と同様に実施した。
このときの溶解装置排出直後のアクリロニトリル系重合体溶液の吸光度Ａ、ノズル吐出直後のアクリロニトリル系重合体溶液の吸光度Ｂ、凝固糸の凝固糸含水率は表１に示した通りであった。
Example 4
The same procedure as in Example 1 was performed except that the passage time of the acrylonitrile-based polymer solution from the discharge port of the dissolution apparatus to the nozzle discharge was adjusted to 10 hours.
At this time, the absorbance A of the acrylonitrile-based polymer solution immediately after discharging of the dissolving apparatus, the absorbance B of the acrylonitrile-based polymer solution immediately after discharging the nozzle, and the moisture content of the coagulated yarn of the coagulated yarn were as shown in Table 1.
（実施例５）
温度調整エリアのシェル側に３５℃の温水を循環させ、温度調整エリア排出直後のアクリロニトリル系重合体溶液の温度を４０℃とし、それ以降からノズルより吐出するまでのアクリロニトリル系重合体溶液を温度４０℃に熱保持しつつ、溶解装置の排出口からノズル吐出までのアクリロニトリル系重合体溶液の通過時間が１９時間となるよう調整した以外は実施例１と同様に実施した。
このときの溶解装置排出直後のアクリロニトリル系重合体溶液の吸光度Ａ、ノズル吐出直後のアクリロニトリル系重合体溶液の吸光度Ｂ、凝固糸の凝固糸含水率は表１に示した通りであった。
(Example 5)
Circulating hot water of 35 ° C. on the shell side of the temperature adjustment area, the temperature of the acrylonitrile polymer solution immediately after discharging the temperature adjustment area is 40 ° C., and the temperature of the acrylonitrile polymer solution after that is discharged from the nozzle is 40 ° C. It was carried out in the same manner as in Example 1 except that the passage time of the acrylonitrile polymer solution from the discharge port of the dissolution apparatus to the nozzle discharge was adjusted to 19 hours while maintaining the temperature at 0 ° C.
At this time, the absorbance A of the acrylonitrile-based polymer solution immediately after discharging of the dissolving apparatus, the absorbance B of the acrylonitrile-based polymer solution immediately after discharging the nozzle, and the moisture content of the coagulated yarn of the coagulated yarn were as shown in Table 1.
（実施例６）
溶解装置のシェル側に１３５℃のシリコンオイルを循環させ、温度調整エリアのシェル側に６５℃の温水を循環させて温度調整エリア排出直後のアクリロニトリル系重合体溶液の温度を７０℃とし、それ以降からノズルより吐出するまでのアクリロニトリル系重合体溶液を温度７０℃に熱保持しつつ、溶解装置の排出口からノズル吐出までのアクリロニトリル系重合体溶液の通過時間が８時間となるよう調整した以外は実施例１と同様に実施した。
このときの溶解装置排出直後のアクリロニトリル系重合体溶液の吸光度Ａ、ノズル吐出直後のアクリロニトリル系重合体溶液の吸光度Ｂ、凝固糸の凝固糸含水率は表１に示した通りであった。
(Example 6)
135 ° C silicone oil is circulated on the shell side of the melting device, 65 ° C hot water is circulated on the shell side of the temperature adjustment area, and the temperature of the acrylonitrile-based polymer solution immediately after discharge of the temperature adjustment area is 70 ° C. The acrylonitrile-based polymer solution from the nozzle to the nozzle is heated at 70 ° C., and the transit time of the acrylonitrile-based polymer solution from the discharge port of the dissolving device to the nozzle is 8 hours. The same operation as in Example 1 was performed.
At this time, the absorbance A of the acrylonitrile-based polymer solution immediately after discharging of the dissolving apparatus, the absorbance B of the acrylonitrile-based polymer solution immediately after discharging the nozzle, and the moisture content of the coagulated yarn of the coagulated yarn were as shown in Table 1.
（実施例７）
溶解装置のシェル側に１４５℃のシリコンオイルを循環させ、温度調整エリアのシェル側に６５℃の温水を循環させて温度調整エリア排出直後のアクリロニトリル系重合体溶液の温度を７０℃とし、それ以降からノズルより吐出するまでのアクリロニトリル系重合体溶液を温度７０℃に熱保持しつつ、溶解装置の排出口からノズル吐出までのアクリロニトリル系重合体溶液の通過時間が８時間になるよう調整した以外は実施例１と同様に実施した。
このときの溶解装置排出直後のアクリロニトリル系重合体溶液の吸光度Ａ、ノズル吐出直後のアクリロニトリル系重合体溶液の吸光度Ｂ、凝固糸の凝固糸含水率は表１に示した通りであった。
(Example 7)
145 ° C. silicone oil is circulated on the shell side of the dissolution apparatus, 65 ° C. hot water is circulated on the shell side of the temperature adjustment area, and the temperature of the acrylonitrile polymer solution immediately after discharge of the temperature adjustment area is 70 ° C., and thereafter Except that the acrylonitrile polymer solution from the nozzle to the nozzle is discharged while being heated at a temperature of 70 ° C. while adjusting the passage time of the acrylonitrile polymer solution from the discharge port of the dissolution apparatus to the nozzle to be 8 hours. The same operation as in Example 1 was performed.
At this time, the absorbance A of the acrylonitrile-based polymer solution immediately after discharging of the dissolving apparatus, the absorbance B of the acrylonitrile-based polymer solution immediately after discharging the nozzle, and the moisture content of the coagulated yarn of the coagulated yarn were as shown in Table 1.
（実施例８）
溶解装置のシェル側に１５０℃のシリコンオイルを循環させ、温度調整エリアのシェル側に３５℃の温水を循環させて温度調整エリア排出直後のアクリロニトリル系重合体溶液の温度を４０℃とし、それ以降からノズルより吐出するまでのアクリロニトリル系重合体溶液を温度４０℃に熱保持しつつ、溶解装置の排出口からノズル吐出までのアクリロニトリル系重合体溶液の通過時間が１時間になるよう調整した以外は実施例１と同様に実施した。
このときの溶解装置排出直後のアクリロニトリル系重合体溶液の吸光度Ａ、ノズル吐出直後のアクリロニトリル系重合体溶液の吸光度Ｂ、凝固糸の凝固糸含水率は表１に示した通りであった。
(Example 8)
150 ° C. silicone oil is circulated on the shell side of the dissolution apparatus, 35 ° C. hot water is circulated on the shell side of the temperature adjustment area, and the temperature of the acrylonitrile polymer solution immediately after discharge of the temperature adjustment area is 40 ° C., and thereafter Except that the acrylonitrile polymer solution from the nozzle to the nozzle discharge is adjusted so that the transit time of the acrylonitrile polymer solution from the discharge port of the dissolving device to the nozzle discharge is 1 hour while keeping the temperature at 40 ° C. The same operation as in Example 1 was performed.
At this time, the absorbance A of the acrylonitrile-based polymer solution immediately after discharging of the dissolving apparatus, the absorbance B of the acrylonitrile-based polymer solution immediately after discharging the nozzle, and the moisture content of the coagulated yarn of the coagulated yarn were as shown in Table 1.
（実施例９）
温度調整エリアのシェル側に７５℃の温水を循環させて温度調整エリア排出直後のアクリロニトリル系重合体溶液の温度を８０℃とし、それ以降からノズルより吐出するまでのアクリロニトリル系重合体溶液を温度８０℃に熱保持しつつ、溶解装置の排出口からノズル吐出までのアクリロニトリル系重合体溶液の通過時間が５時間になるよう調整した以外は実施例１と同様に実施した。
このときの溶解装置排出直後のアクリロニトリル系重合体溶液の吸光度Ａ、ノズル吐出直後のアクリロニトリル系重合体溶液の吸光度Ｂ、凝固糸の凝固糸含水率は表１に示した通りであった。
Example 9
The temperature of the acrylonitrile polymer solution immediately after discharge of the temperature adjustment area is set to 80 ° C. by circulating 75 ° C. warm water to the shell side of the temperature adjustment area, and the temperature of the acrylonitrile polymer solution after that is discharged from the nozzle to a temperature of 80 ° C. It was carried out in the same manner as in Example 1 except that the passage time of the acrylonitrile-based polymer solution from the discharge port of the dissolution apparatus to the nozzle discharge was adjusted to 5 hours while keeping the temperature at 0 ° C.
At this time, the absorbance A of the acrylonitrile-based polymer solution immediately after discharging of the dissolving apparatus, the absorbance B of the acrylonitrile-based polymer solution immediately after discharging the nozzle, and the moisture content of the coagulated yarn of the coagulated yarn were as shown in Table 1.
（実施例１０）
溶解装置のシェル側に１５５℃のシリコンオイルを循環させ、温度調整エリアのシェル側に３０℃の温水を循環させて温度調整エリア排出直後のアクリロニトリル系重合体溶液の温度を３５℃とし、それ以降からノズルより吐出するまでのアクリロニトリル系重合体溶液を温度３５℃にて熱保持しつつ、溶解装置の排出口からノズル吐出までのアクリロニトリル系重合体溶液の通過時間が２時間となるよう調整した以外は実施例１と同様に実施した。
このときの溶解装置排出直後のアクリロニトリル系重合体溶液の吸光度Ａ、ノズル吐出直後のアクリロニトリル系重合体溶液の吸光度Ｂ、凝固糸の凝固糸含水率は表１に示した通りであった。
(Example 10)
155 ° C. silicone oil is circulated on the shell side of the dissolution apparatus, 30 ° C. hot water is circulated on the shell side of the temperature adjustment area, and the temperature of the acrylonitrile polymer solution immediately after discharge of the temperature adjustment area is 35 ° C. Except that the acrylonitrile-based polymer solution was discharged from the nozzle until it was discharged from the nozzle at a temperature of 35 ° C., and the passage time of the acrylonitrile-based polymer solution from the discharge port of the dissolving device to the nozzle was 2 hours. Was carried out in the same manner as in Example 1.
At this time, the absorbance A of the acrylonitrile-based polymer solution immediately after discharging of the dissolving apparatus, the absorbance B of the acrylonitrile-based polymer solution immediately after discharging the nozzle, and the moisture content of the coagulated yarn of the coagulated yarn were as shown in Table 1.
（比較例１）
溶解装置の排出口からノズル吐出までのアクリロニトリル系重合体溶液の通過時間が０．２時間となるよう調整した以外は実施例１と同様に実施した。
このときの溶解装置排出直後のアクリロニトリル系重合体溶液の吸光度Ａ、ノズル吐出直後のアクリロニトリル系重合体溶液の吸光度Ｂ、凝固糸の凝固糸含水率は表１に示した通りであった。また、凝固糸含水率は１３０％と実施例１と比較して高い値となった。
(Comparative Example 1)
The same procedure as in Example 1 was performed except that the passage time of the acrylonitrile-based polymer solution from the discharge port of the dissolution apparatus to the nozzle discharge was adjusted to 0.2 hours.
At this time, the absorbance A of the acrylonitrile-based polymer solution immediately after discharging of the dissolving apparatus, the absorbance B of the acrylonitrile-based polymer solution immediately after discharging the nozzle, and the moisture content of the coagulated yarn of the coagulated yarn were as shown in Table 1. Further, the moisture content of the coagulated yarn was 130%, which was higher than that of Example 1.
（比較例２）
溶解装置の排出口からノズル吐出までのアクリロニトリル系重合体溶液の通過時間が３０時間となるよう調整した以外は実施例１と同様に実施した。
このときの溶解装置排出直後のアクリロニトリル系重合体溶液の吸光度Ａ、ノズル吐出直後のアクリロニトリル系重合体溶液の吸光度Ｂ、凝固糸の凝固糸含水率は表１に示した通りであった。また、凝固糸含水率は１３５％と実施例１と比較して高い値となった。
(Comparative Example 2)
The same procedure as in Example 1 was performed except that the passage time of the acrylonitrile-based polymer solution from the discharge port of the dissolution apparatus to the nozzle discharge was adjusted to 30 hours.
At this time, the absorbance A of the acrylonitrile-based polymer solution immediately after discharging of the dissolving apparatus, the absorbance B of the acrylonitrile-based polymer solution immediately after discharging the nozzle, and the moisture content of the coagulated yarn of the coagulated yarn were as shown in Table 1. Further, the moisture content of the coagulated yarn was 135%, which was higher than that of Example 1.
（比較例３）
温度調整エリアのシェル側に１２０℃のシリコンオイルを循環させて温度調整エリア排出直後のアクリロニトリル系重合体溶液の温度を１１０℃とし、それ以降からノズルより吐出するまでのアクリロニトリル系重合体溶液を１１０℃に熱保持しつつ、溶解装置の排出口からノズル吐出までのアクリロニトリル系重合体溶液の通過時間が８時間となるよう調整した以外は実施例１と同様に実施した。
このときの溶解装置排出直後のアクリロニトリル系重合体溶液の吸光度Ａは表１に示した通りであった。また、熱保持後のアクリロニトリル系重合体溶液は粘度が高く、吸光度を測定することができず、ノズルより吐出して凝固糸を得ることができなかった。
(Comparative Example 3)
Circulating silicone oil at 120 ° C. on the shell side of the temperature adjustment area to set the temperature of the acrylonitrile polymer solution immediately after discharge of the temperature adjustment area to 110 ° C., and 110% of the acrylonitrile polymer solution from then on until discharging from the nozzle. The process was carried out in the same manner as in Example 1 except that the passage time of the acrylonitrile polymer solution from the discharge port of the dissolution apparatus to the nozzle discharge was adjusted to 8 hours while maintaining the temperature at 0 ° C.
The absorbance A of the acrylonitrile-based polymer solution immediately after discharging the dissolution apparatus at this time was as shown in Table 1. Moreover, the acrylonitrile-based polymer solution after heat retention had a high viscosity, the absorbance could not be measured, and the coagulated yarn could not be obtained by discharging from the nozzle.
（比較例４）
温度調整エリアのシェル側に５℃の冷水を循環させて温度調整エリア排出直後のアクリロニトリル系重合体溶液の温度を１０℃とし、それ以降からノズルより吐出するまでのアクリロニトリル系重合体溶液を１０℃に熱保持しつつ、溶解装置の排出口からノズル吐出までのアクリロニトリル系重合体溶液の通過時間が５時間となるよう調整した以外は実施例１と同様に実施した。
このときの溶解装置排出直後のアクリロニトリル系重合体溶液の吸光度Ａ、ノズル吐出直後のアクリロニトリル系重合体溶液の吸光度Ｂ、凝固糸の凝固糸含水率は表１に示した通りであった。また、熱保持後のアクリロニトリル系重合体溶液は粘度が高く、ノズルより吐出して凝固糸を得ることができなかった。
(Comparative Example 4)
Chilled water of 5 ° C is circulated on the shell side of the temperature adjustment area so that the temperature of the acrylonitrile polymer solution immediately after discharge of the temperature adjustment area is 10 ° C, and the acrylonitrile polymer solution after that is discharged from the nozzle is 10 ° C. This was carried out in the same manner as in Example 1 except that the passage time of the acrylonitrile-based polymer solution from the discharge port of the dissolution apparatus to the nozzle discharge was adjusted to 5 hours while maintaining the heat.
At this time, the absorbance A of the acrylonitrile-based polymer solution immediately after discharging of the dissolving apparatus, the absorbance B of the acrylonitrile-based polymer solution immediately after discharging the nozzle, and the moisture content of the coagulated yarn of the coagulated yarn were as shown in Table 1. Further, the acrylonitrile-based polymer solution after heat retention had a high viscosity, and a coagulated yarn could not be obtained by discharging from the nozzle.
（比較例５）
溶解装置のシェル側に１６５℃のシリコンオイルを循環させ、温度調整エリアのシェル側に３０℃の温水を循環させて温度調整エリア排出直後のアクリロニトリル系重合体溶液の温度を３５℃とし、それ以降からノズルより吐出するまでのアクリロニトリル系重合体溶液を温度３５℃に熱保持しつつ、溶解装置の排出口からノズル吐出までのアクリロニトリル系重合体溶液の通過時間が０．２時間となるよう調整した以外は実施例１と同様に実施した。
このときの溶解装置排出直後のアクリロニトリル系重合体溶液の吸光度Ａ、ノズル吐出直後のアクリロニトリル系重合体溶液の吸光度Ｂ、凝固糸の凝固糸含水率は表１に示した通りであった。また、凝固糸含水率は１３７％と実施例１と比較して高い値となった。
(Comparative Example 5)
165 ° C. silicone oil is circulated on the shell side of the dissolving device, 30 ° C. hot water is circulated on the shell side of the temperature adjustment area, and the temperature of the acrylonitrile polymer solution immediately after discharging the temperature adjustment area is 35 ° C. While the acrylonitrile polymer solution from the nozzle to the nozzle is discharged at a temperature of 35 ° C., the passage time of the acrylonitrile polymer solution from the dissolution apparatus outlet to the nozzle is adjusted to be 0.2 hours. Except for this, the same procedure as in Example 1 was performed.
At this time, the absorbance A of the acrylonitrile-based polymer solution immediately after discharging of the dissolving apparatus, the absorbance B of the acrylonitrile-based polymer solution immediately after discharging the nozzle, and the moisture content of the coagulated yarn of the coagulated yarn were as shown in Table 1. Further, the moisture content of the coagulated yarn was 137%, which was higher than that of Example 1.
（比較例６）
溶解装置のシェル側に５０℃の温水を循環させ、温度調整エリアのシェル側に５０℃の温水を循環させて温度調整エリア排出直後のアクリロニトリル系重合体溶液の温度を５０℃とし、それ以降からノズルより吐出するまでのアクリロニトリル系重合体溶液を温度５０℃に熱保持しつつ、溶解装置の排出口からノズル吐出までのアクリロニトリル系重合体溶液の通過時間が０．２時間となるよう調整した以外は実施例１と同様に実施した。
このときの溶解装置排出直後のアクリロニトリル系重合体溶液の吸光度Ａ、ノズル吐出直後のアクリロニトリル系重合体溶液の吸光度Ｂは表１に示した通りであった。また、ノズル孔の閉塞が著しく、凝固糸を得ることができなかった。
(Comparative Example 6)
50 ° C. warm water is circulated on the shell side of the dissolution apparatus, 50 ° C. warm water is circulated on the shell side of the temperature adjustment area, and the temperature of the acrylonitrile polymer solution immediately after discharge of the temperature adjustment area is 50 ° C. Other than adjusting the acrylonitrile polymer solution until it is discharged from the nozzle at a temperature of 50 ° C. so that the passing time of the acrylonitrile polymer solution from the discharge port of the dissolving device to the nozzle discharge is 0.2 hours Was carried out in the same manner as in Example 1.
At this time, the absorbance A of the acrylonitrile-based polymer solution immediately after discharge of the dissolving apparatus and the absorbance B of the acrylonitrile-based polymer solution immediately after discharging the nozzle were as shown in Table 1. Further, the nozzle hole was clogged so that a coagulated yarn could not be obtained.
Claims (6)
吸光度測定方法
アクリロニトリル系重合体溶液の吸光度は下記測定方法により得られる。
アクリロニトリル系重合体溶液を溶液と同じ溶媒にて質量換算で２０倍に希釈し、厚さ１ｃｍのセルに入れ、波長３５０ｎｍにおける吸光度Ｘを測定する。
また、溶媒のみを厚さ１ｃｍのセルに入れ、波長３５０ｎｍにおける吸光度Ｙを測定する。吸光度Ｘから吸光度Ｙの値を差し引いた値をアクリロニトリル系重合体溶液の吸光度とする。吸光度測定時の温度は３０℃とする。 4. The carbon according to claim 1, wherein the absorbance A according to the following measurement method of the acrylonitrile-based polymer solution immediately after being discharged from the discharge port of the dissolution apparatus is 0.030 or more and 0.160 or less. A method for producing a fiber precursor acrylonitrile fiber.
Absorbance measurement method The absorbance of the acrylonitrile polymer solution can be obtained by the following measurement method.
The acrylonitrile-based polymer solution is diluted 20-fold in terms of mass with the same solvent as the solution, put in a cell having a thickness of 1 cm, and the absorbance X at a wavelength of 350 nm is measured.
Further, only the solvent is put into a cell having a thickness of 1 cm, and the absorbance Y at a wavelength of 350 nm is measured. The value obtained by subtracting the value of absorbance Y from absorbance X is defined as the absorbance of the acrylonitrile-based polymer solution. The temperature during the absorbance measurement is 30 ° C.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2013242487A JP6217342B2 (en) | 2013-11-25 | 2013-11-25 | Method for producing carbon fiber precursor acrylonitrile fiber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2013242487A JP6217342B2 (en) | 2013-11-25 | 2013-11-25 | Method for producing carbon fiber precursor acrylonitrile fiber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2015101803A JP2015101803A (en) | 2015-06-04 |
| JP6217342B2 true JP6217342B2 (en) | 2017-10-25 |
Family
ID=53377763
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2013242487A Active JP6217342B2 (en) | 2013-11-25 | 2013-11-25 | Method for producing carbon fiber precursor acrylonitrile fiber |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP6217342B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR102301665B1 (en) * | 2017-11-24 | 2021-09-14 | 주식회사 엘지화학 | Method for preparing acrylonitrile based polymer |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ATE497551T1 (en) * | 2004-12-27 | 2011-02-15 | Toray Industries | OIL LAVIVAGE FOR CARBON FIBER PRECURSOR FIBER, CARBON FIBER AND METHOD FOR PRODUCING CARBON FIBER |
| JP4543922B2 (en) * | 2004-12-27 | 2010-09-15 | 東レ株式会社 | Silicone oil agent for carbon fiber precursor fiber, carbon fiber precursor fiber, flame-resistant fiber, carbon fiber and production method thereof |
| JP2006348422A (en) * | 2005-06-16 | 2006-12-28 | Toray Ind Inc | Acrylonitrile based polymer solution for carbon fiber and method for producing the same |
| JP2007182645A (en) * | 2006-01-06 | 2007-07-19 | Toray Ind Inc | Method for producing acrylic fiber |
| JP4979478B2 (en) * | 2007-06-19 | 2012-07-18 | 三菱レイヨン株式会社 | Acrylonitrile-based carbon fiber precursor fiber bundle, carbon fiber bundle using the same, and method for producing the same |
| JP6145960B2 (en) * | 2011-08-22 | 2017-06-14 | 三菱ケミカル株式会社 | Method for producing acrylonitrile polymer solution and method for producing carbon fiber precursor acrylonitrile fiber |
-
2013
- 2013-11-25 JP JP2013242487A patent/JP6217342B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| JP2015101803A (en) | 2015-06-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR100364655B1 (en) | Acrylonitrile-based precursor fiber for carbon fiber, process for producing the same, and carbon fiber obtained from the precursor fiber | |
| JP6119168B2 (en) | Method for producing flame-resistant fiber bundle and method for producing carbon fiber bundle | |
| TWI465468B (en) | Production method of acrylonitrile-based copolymer, and production method of polyacrylonitrile precursor for carbon fiber | |
| JP2011046942A (en) | Polyacrylonitrile copolymer, polyacrylonitrile precursor fiber for carbon fiber, and manufacturing method for carbon fiber | |
| JP2013103992A (en) | Polyacrylonitrile-based copolymer for carbon fiber precursor fiber | |
| JP2010100970A (en) | Method for producing carbon fiber | |
| JPH04281019A (en) | Acrylic yarn bundle for producing carbon yarn and its production | |
| JP6217342B2 (en) | Method for producing carbon fiber precursor acrylonitrile fiber | |
| JP6145960B2 (en) | Method for producing acrylonitrile polymer solution and method for producing carbon fiber precursor acrylonitrile fiber | |
| KR20140074136A (en) | Precursor manufacturing device of carbon fiber | |
| KR101148428B1 (en) | Method of preparing precursors for polyacrylonitrile-based carbon fibers | |
| KR20100073760A (en) | Method for preparing carbon fiber precursor | |
| JP2006188792A (en) | Spinning bath apparatus and acrylic fiber bundle | |
| JP6264819B2 (en) | Acrylonitrile copolymer, carbon fiber precursor acrylonitrile fiber, carbon fiber, and method for producing carbon fiber | |
| JP2017137602A (en) | Manufacturing method of polyacrylonitrile fiber bundle | |
| JP2008280632A (en) | Method for producing precursor fiber bundle of carbon fiber | |
| JP2021139062A (en) | Production method of carbon fiber bundle | |
| JP6232897B2 (en) | Method for producing carbon fiber precursor acrylonitrile fiber | |
| KR101490530B1 (en) | Method of preparing precursors for polyacrylonitrile-based carbon fibers | |
| KR101364788B1 (en) | Process for treating oil on the precursor fiber for preparing a carbon fiber | |
| KR20120077628A (en) | Carbon fiber precursor and manufacturing method | |
| KR101429381B1 (en) | Process for preparing a carbon fiber precursor | |
| JP2017186682A (en) | Manufacturing method of precursor fiber bundle for carbon fiber and manufacturing method of carbon fiber | |
| JP2022098766A (en) | Polyacrylonitrile fiber and method of producing the same | |
| JP2023163084A (en) | Manufacturing method of polyacrylonitrile 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: 20161118 |
|
| 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: 20170829 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20170831 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20170911 |
|
| R151 | Written notification of patent or utility model registration |
Ref document number: 6217342 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R151 |