JP2020147877A

JP2020147877A - Manufacturing method of sized carbon fiber bundle

Info

Publication number: JP2020147877A
Application number: JP2019048388A
Authority: JP
Inventors: 剛高田; Takeshi Takada; 和直晴山; Kazunao Hareyama
Original assignee: Mitsubishi Chemical Corp; Mitsubishi Chemical Holdings Corp
Current assignee: Mitsubishi Chemical Corp; Mitsubishi Chemical Group Corp
Priority date: 2019-03-15
Filing date: 2019-03-15
Publication date: 2020-09-17

Abstract

To provide a manufacturing method of a sized carbon fiber bundle having less fuzz and exhibiting excellent quality by maintaining a good binding state of a carbon fiber bundle in a manufacturing process of a carbon fiber bundle.SOLUTION: The manufacturing method of a sized carbon fiber bundle includes: a carbonizing treatment process for introducing a flame-resistant fiber bundle into a carbonizing furnace and giving a heat treatment in an inert atmosphere for converting to a carbonized fiber bundle, followed by a surface treatment process for giving an electrolytic oxidation treatment to the carbonized fiber bundle for converting to a surface-treated carbon fiber bundle, and followed by a sizing treatment process for giving a sizing treatment to the surface-treated carbon fiber bundle, wherein between the carbonizing treatment process and the surface treatment process, or, between the surface treatment process and the sizing treatment step, an aqueous solution having a surface tension of 60 mN/m or under is allowed to be incorporated into the carbonizing fiber bundle or the surface-treated carbon fiber bundle.SELECTED DRAWING: None

Description

本発明は、毛羽が少なく、品位に優れたサイジング剤付き炭素繊維束の製造方法に関する。 The present invention relates to a method for producing a carbon fiber bundle with a sizing agent, which has less fluff and is excellent in quality.

炭素繊維は優れた強度を有するため、航空宇宙用素材、スポーツレジャー用素材、圧力容器などの工業用途用素材として極めて有用であり、需要が拡大している。一般に炭素繊維は、数千〜数万本からなるアクリル繊維などの単繊維を集め束ねた炭素繊維前駆体繊維束を焼成し、炭素繊維束として製造される。炭素繊維束は、通常そのままでは利用されず、マトリックス樹脂と組み合わせて繊維強化複合材料として成形されて様々な用途に利用される。成形された繊維強化複合材料の外観を良好に仕上げるため、毛羽が少なく品位に優れた炭素繊維束が望まれている。 Since carbon fiber has excellent strength, it is extremely useful as an aerospace material, a material for sports and leisure, and a material for industrial use such as a pressure vessel, and its demand is expanding. Generally, carbon fibers are produced as carbon fiber bundles by firing a carbon fiber precursor fiber bundle in which single fibers such as acrylic fibers composed of thousands to tens of thousands are collected and bundled. The carbon fiber bundle is not usually used as it is, but is molded as a fiber-reinforced composite material in combination with a matrix resin and used for various purposes. In order to improve the appearance of the molded fiber-reinforced composite material, a carbon fiber bundle having less fluff and excellent quality is desired.

炭素繊維束がその製造工程中に設置される炭素繊維束を搬送するためのガイドローラーや、走行位置を規制するためのピンガイド等に接触すると、炭素繊維束の集束状態が変化する。特に、繊維束を構成する単繊維同士の絡み合い(交絡)が少ない炭素繊維前駆体繊維束を用いた場合には、繊維束が集束した状態を維持させることが難しく、数本〜数十本の単繊維がばらける現象が発生する場合がある。このばらけた単繊維は隣接して走行する別の炭素繊維束に絡まり、糸切れ（毛羽）などのトラブルとなりやすい。そのため、製造工程中において炭素繊維束が良好に集束した状態を維持することが重要である。 When the carbon fiber bundle comes into contact with a guide roller for transporting the carbon fiber bundle installed during the manufacturing process, a pin guide for regulating the traveling position, or the like, the focused state of the carbon fiber bundle changes. In particular, when a carbon fiber precursor fiber bundle with less entanglement (entanglement) between the single fibers constituting the fiber bundle is used, it is difficult to maintain the fiber bundle in a focused state, and several to several tens of fibers are used. The phenomenon that the single fibers come apart may occur. These loose single fibers are entangled with another carbon fiber bundle that runs adjacently, and are liable to cause troubles such as thread breakage (fluff). Therefore, it is important to maintain a state in which the carbon fiber bundles are well focused during the manufacturing process.

特許文献１では、炭素化炉から黒鉛化炉の間で水を付着させることにより、黒鉛化完了まで炭素繊維束が良好に集束した状態を維持して、黒鉛化工程における擦過による毛羽が抑えて、糸切れ、毛羽の少ない高品質な炭素繊維を得る技術が提案されている。 In Patent Document 1, by adhering water between the carbonization furnace and the graphitization furnace, the carbon fiber bundles are maintained in a well-focused state until the completion of graphitization, and fluff due to scratching in the graphitization step is suppressed. A technique for obtaining high-quality carbon fiber with less thread breakage and fluff has been proposed.

特許文献２では、耐炎繊維又は炭素繊維に高分子系の特定化学物質を特定量付着させることにより、炭素化炉、黒鉛化炉で堆積してくる毛羽や繊維屑を減少させて、糸道の狭窄を防いで通過する繊維束の毛羽発生を抑え、炉に至るまでのガイドローラーでの毛羽立ち、巻き付きを防止し、また耐炎化工程で発生した膠着を解繊し、高性能かつ、毛羽の少ない高品位の炭素繊維又は黒鉛繊維を得る技術が提案されている。 In Patent Document 2, by adhering a specific amount of a specific polymer-based chemical substance to flame-resistant fiber or carbon fiber, fluff and fiber waste accumulated in a carbonization furnace and a graphitization furnace are reduced, and the thread path Prevents squeezing and suppresses the generation of fluff in the fiber bundles that pass through, prevents fluffing and wrapping in the guide roller leading to the furnace, and deflate the sticking generated in the flame resistance process, resulting in high performance and less fluff. A technique for obtaining high-grade carbon fiber or graphite fiber has been proposed.

昭５８−２１４５２４1983-214524 昭５９−６６５１８1984-66518

しかしながら、特許文献１に記載の方法では、炭素化および黒鉛化工程の以降の後工程において炭素繊維束が良好に集束した状態を維持することを目的としていないため、後工程における毛羽の発生を抑えられない場合があった。 However, the method described in Patent Document 1 does not aim to maintain a well-focused state of carbon fiber bundles in the subsequent post-processes of the carbonization and graphitization steps, and thus suppresses the generation of fluff in the post-processes. In some cases it was not possible.

また、特許文献２に記載の方法では、炭素化繊維束となる工程を経ると、特定化学物質の大部分は揮発、または熱分解により消失してしまい、炭素化、および黒鉛化工程以降において炭素繊維束を良好に集束した状態を維持できず、毛羽の発生を抑えられない場合があった。 Further, in the method described in Patent Document 2, most of the specific chemical substances are lost by volatilization or thermal decomposition after the step of forming carbonized fiber bundles, and carbon is carbonized after the carbonization and graphitization steps. In some cases, it was not possible to maintain a well-focused state of the fiber bundles, and it was not possible to suppress the occurrence of fluff.

本発明は、炭素繊維束の製造工程中で、炭素繊維束の集束状態を効果的に維持し、毛羽が少なく、品位に優れたサイジング剤付き炭素繊維束の製造方法を提供することを目的とする。 An object of the present invention is to provide a method for producing a carbon fiber bundle with a sizing agent, which effectively maintains the focused state of the carbon fiber bundle in the process of producing the carbon fiber bundle, has less fluff, and is excellent in quality. To do.

本発明は以下の態様を含む。
［１］耐炎化繊維束を炭素化炉に導入し不活性雰囲気下で加熱処理して炭素化繊維束とする工程と、次いで前記炭素化繊維束を電解酸化処理し表面処理済炭素繊維束とする工程と、次いで前記表面処理済炭素繊維束をサイジング処理しサイジング剤付き炭素繊維束とする工程とを含む、サイジング剤付き炭素繊維束の製造方法であって、前記炭素化繊維束を電解酸化処理する前に、表面張力が６０ｍＮ／ｍ以下の水溶液を前記炭素化繊維束に、含水率１０〜２０％の範囲で含ませることを含ませる、サイジング剤付き炭素繊維束の製造方法。
［２］耐炎化繊維束を炭素化炉に導入し不活性雰囲気下で加熱処理して炭素化繊維束とする工程と、次いで前記炭素化繊維束を電解酸化処理し表面処理済炭素繊維束とする工程と、次いで前記表面処理済炭素繊維束をサイジング処理しサイジング剤付き炭素繊維束とする工程とを含む、サイジング剤付き炭素繊維束の製造方法であって、前記表面処理済炭素繊維束をサイジング処理する前に、表面張力が６０ｍＮ／ｍ以下の水溶液を前記表面処理済炭素繊維束に含水率１０〜２０％の範囲で含ませる、サイジング剤付き炭素繊維束の製造方法。
［３］前記表面張力が６０ｍＮ／ｍ以下の水溶液として、界面活性剤を含有する水溶液を用いる、［１］または［２］に記載のサイジング剤付き炭素繊維束の製造方法。 The present invention includes the following aspects.
[1] A step of introducing a flame-resistant fiber bundle into a carbonization furnace and heat-treating it in an inert atmosphere to form a carbonized fiber bundle, and then electrolytically oxidizing the carbonized fiber bundle to form a surface-treated carbon fiber bundle. A method for producing a carbon fiber bundle with a sizing agent, which comprises a step of sizing the surface-treated carbon fiber bundle to obtain a carbon fiber bundle with a sizing agent, wherein the carbonized fiber bundle is electrolytically oxidized. A method for producing a carbon fiber bundle with a sizing agent, which comprises including an aqueous solution having a surface tension of 60 mN / m or less in the carbonized fiber bundle in a water content range of 10 to 20% before the treatment.
[2] A step of introducing the flame-resistant fiber bundle into a carbonization furnace and heat-treating it in an inert atmosphere to form a carbonized fiber bundle, and then electrolytically oxidizing the carbonized fiber bundle to form a surface-treated carbon fiber bundle. A method for producing a carbon fiber bundle with a sizing agent, which comprises a step of sizing the surface-treated carbon fiber bundle to obtain a carbon fiber bundle with a sizing agent. A method for producing a carbon fiber bundle with a sizing agent, wherein an aqueous solution having a surface tension of 60 mN / m or less is contained in the surface-treated carbon fiber bundle in a water content range of 10 to 20% before the sizing treatment.
[3] The method for producing a carbon fiber bundle with a sizing agent according to [1] or [2], wherein an aqueous solution containing a surfactant is used as the aqueous solution having a surface tension of 60 mN / m or less.

毛羽の少ない高品質な炭素繊維を得るための製造方法を提供できる。 It is possible to provide a manufacturing method for obtaining high quality carbon fiber with less fluff.

炭素繊維束の毛羽本数の測定の概要を示す模式図である。It is a schematic diagram which shows the outline of the measurement of the number of fluffs of a carbon fiber bundle. 繊維束に処理液をタッチロール方式で含ませる装置の概要を示す模式図である。It is a schematic diagram which shows the outline of the apparatus which includes the processing liquid in a fiber bundle by a touch roll method. 繊維束に処理液を浸漬方で含ませる装置の概要を示す模式図である。It is a schematic diagram which shows the outline of the apparatus which immerses a processing liquid in a fiber bundle by a dipping method.

本発明に用いる耐炎化繊維束は、例えば、炭素繊維前駆体アクリル繊維束を酸化性雰囲気中で加熱処理し耐炎化繊維束を得る工程（以下、「耐炎化処理工程と記載する」）によって得ることができる。
本発明のサイジング剤付き炭素繊維束の製造方法は、耐炎化繊維束を不活性雰囲気中で加熱処理して炭素化繊維束を得る工程（以下、「炭素化処理工程」と記載する）と、前記炭素化繊維束を電解酸化処理し表面処理済炭素繊維束とする工程（以下、「表面処理工程」と記載する）と、前記の表面処理済炭素繊維束をサイジング処理してサイジング剤付き炭素繊維束とする工程（以下、「サイジング処理工程」と記載する）を含む。
耐炎化処理工程における温度条件や伸長条件には、続く炭素化処理工程において糸切れなどのトラブルが発生しない限りは特に制限はなく、従来公知の方法で耐炎化処理することができる。 The flame-resistant fiber bundle used in the present invention is obtained, for example, by a step of heat-treating a carbon fiber precursor acrylic fiber bundle in an oxidizing atmosphere to obtain a flame-resistant fiber bundle (hereinafter, referred to as “flame-resistant treatment step”). be able to.
The method for producing a carbon fiber bundle with a sizing agent of the present invention includes a step of heat-treating the flame-resistant fiber bundle in an inert atmosphere to obtain a carbonized fiber bundle (hereinafter, referred to as "carbonization treatment step"). A step of electrolytically oxidizing the carbonized fiber bundle to obtain a surface-treated carbon fiber bundle (hereinafter referred to as "surface treatment step") and a sizing treatment of the surface-treated carbon fiber bundle to obtain carbon with a sizing agent. It includes a step of forming a fiber bundle (hereinafter, referred to as a “sizing treatment step”).
The temperature conditions and elongation conditions in the flameproofing treatment step are not particularly limited as long as troubles such as thread breakage do not occur in the subsequent carbonization treatment step, and the flameproofing treatment can be performed by a conventionally known method.

炭素化処理工程における温度条件や伸長条件としては特に制限はないが、所望の性能が得られるように、従来公知の方法で炭素化処理を行うことができる。また、炭素化処理工程では、炭素化炉を複数設置して、不活性雰囲気化での加熱処理を複数回に分割して実施しても良い。 The temperature conditions and elongation conditions in the carbonization treatment step are not particularly limited, but the carbonization treatment can be performed by a conventionally known method so as to obtain desired performance. Further, in the carbonization treatment step, a plurality of carbonization furnaces may be installed and the heat treatment in the inert atmosphere may be carried out in a plurality of times.

表面処理工程の後には、炭素化繊維束に残留する電解液を除去するための洗浄処理を行い、引き続き洗浄した炭素化繊維束に残留する洗浄液を乾燥させることができる。乾燥方法は、ロール乾燥、熱風乾燥および輻射熱乾燥などの方法が採用できる。 After the surface treatment step, a cleaning treatment for removing the electrolytic solution remaining in the carbonized fiber bundle can be performed, and the cleaning liquid remaining in the subsequently washed carbonized fiber bundle can be dried. As the drying method, methods such as roll drying, hot air drying and radiant heat drying can be adopted.

サイジング処理工程では、サイジング剤を水に分散させたサイジング液を表面処理済み炭素繊維に含ませて、続いて、サイジング液を含ませた表面処理済み炭素繊維を乾燥させて、サイジング剤付き炭素繊維を得る。サイジング剤は特に限定はない。なお、表面処理済炭素繊維へサイジング液を含ませる方法は、噴霧法、浸漬法、タッチロール法などの公知の方法を用いることができる。乾燥させる方法は、ロール乾燥、熱風乾燥および輻射熱乾燥など公知のいずれの技術も採用できる。 In the sizing treatment step, the surface-treated carbon fiber is impregnated with a sizing solution in which the sizing agent is dispersed in water, and then the surface-treated carbon fiber containing the sizing solution is dried to obtain the carbon fiber with the sizing agent. To get. The sizing agent is not particularly limited. As a method for impregnating the surface-treated carbon fiber with the sizing liquid, a known method such as a spray method, a dipping method, or a touch roll method can be used. As the drying method, any known technique such as roll drying, hot air drying and radiant heat drying can be adopted.

表面張力が６０ｍＮ／ｍ以下の水溶液（以下、「処理液」と記載する場合もある）を、炭素化繊維束または表面処理済み炭素繊維束に含ませる方法としては、毛羽発生等のトラブルが生じない限り、噴霧法、浸漬法、タッチロール法などの公知の方法を用いることができる。 As a method of including an aqueous solution having a surface tension of 60 mN / m or less (hereinafter, sometimes referred to as "treatment liquid") in the carbonized fiber bundle or the surface-treated carbon fiber bundle, troubles such as fluffing occur. Unless otherwise specified, known methods such as a spray method, a dipping method, and a touch roll method can be used.

本発明において、炭素化繊維束または表面処理済み炭素繊維束に含ませる処理液は、メタノール、エタノール、界面活性剤などの、水の表面張力を低下させる作用がある物質を水に添加し、表面張力が６０ｍＮ／ｍ以下となるように調整したものを用いる。上記の物質の中でも、安全に取り扱える点、少量の添加で表面張力を低下させられる点や、さらには炭素化繊維束または表面処理済み炭素繊維束に含ませた際に単繊維間の摩擦を低減し、糸切れなどのトラブルを抑制する効果も得られることから、界面活性剤を選択することが好ましい。界面活性剤としては、アニオン界面活性剤、カチオン界面活性剤、両性界面活性剤、ノニオン界面活性剤を用いることができる。 In the present invention, the treatment liquid contained in the carbonized fiber bundle or the surface-treated carbon fiber bundle is prepared by adding a substance having an action of lowering the surface tension of water, such as methanol, ethanol, and a surfactant, to the water and surface. The one adjusted so that the tension is 60 mN / m or less is used. Among the above substances, it can be handled safely, the surface tension can be reduced by adding a small amount, and the friction between single fibers is reduced when it is contained in a carbonized fiber bundle or a surface-treated carbon fiber bundle. However, it is preferable to select a surfactant because it also has an effect of suppressing troubles such as thread breakage. As the surfactant, an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant can be used.

炭素化処理工程と表面処理工程の間で、炭素化繊維束に処理液を含ませる場合には、炭素化繊維束に含ませた処理液が電解液に混入し、電解処理槽内のイオン濃度が変わり、酸化処理に影響を与える可能性があるため、界面活性剤として、ノニオン界面活性剤を用いることがより好ましい。 When the treatment liquid is contained in the carbonized fiber bundle between the carbonization treatment step and the surface treatment step, the treatment liquid contained in the carbonized fiber bundle is mixed in the electrolytic solution, and the ion concentration in the electrolytic treatment tank. It is more preferable to use a nonionic surfactant as the surfactant, because the surfactant may change and affect the oxidation treatment.

炭素化繊維束または表面処理済み炭素繊維束に含ませる処理液の表面張力は、６０ｍＮ／ｍ以下が好ましく、４０ｍＮ／ｍ以下がさらに好ましい。 The surface tension of the treatment liquid contained in the carbonized fiber bundle or the surface-treated carbon fiber bundle is preferably 60 mN / m or less, and more preferably 40 mN / m or less.

また、表面処理工程とサイジング処理工程の間で、表面処理済炭素繊維束に処理液を含ませる場合は、表面処理済炭素繊維束が水との親和性を有しているが、表面張力が６０ｍＮ／ｍ以下の水溶液の方が、効率よく含ませることができるので好ましい。 Further, when the surface-treated carbon fiber bundle contains the treatment liquid between the surface treatment step and the sizing treatment step, the surface-treated carbon fiber bundle has an affinity for water, but the surface tension is high. An aqueous solution of 60 mN / m or less is preferable because it can be contained efficiently.

本発明において、炭素化繊維束または表面処理済炭素繊維束に含ませる処理液の、処理液を含んだ状態の炭素化繊維束または表面処理済炭素繊維束の総質量に対する量（以下、「含水率」と記載する場合がある）は、炭素化繊維束または表面処理済炭素繊維束の集束状態を維持できる必要があるため、１０〜３０質量％とするのが好ましい。含水率が１０質量％以上であれば、炭素化繊維束または表面処理済炭素繊維束の集束状態を十分に維持することが出来るし、また３０質量％以下であれば、炭素化繊維束または表面処理済炭素繊維束に含ませた処理液が、後の工程に設置されるガイドローラーなどを汚染して単糸が巻き付くようなトラブルを防止することができる。より好ましい範囲は、１５〜２５質量％である。 In the present invention, the amount of the treatment liquid contained in the carbonized fiber bundle or the surface-treated carbon fiber bundle with respect to the total mass of the carbonized fiber bundle or the surface-treated carbon fiber bundle containing the treatment liquid (hereinafter, "water-containing"). The ratio) may be described as 10 to 30% by mass because it is necessary to maintain the focused state of the carbonized fiber bundle or the surface-treated carbon fiber bundle. When the water content is 10% by mass or more, the focused state of the carbonized fiber bundle or the surface-treated carbon fiber bundle can be sufficiently maintained, and when it is 30% by mass or less, the carbonized fiber bundle or the surface is sufficiently maintained. It is possible to prevent troubles such as the treatment liquid contained in the treated carbon fiber bundle contaminating the guide roller or the like installed in the subsequent process and winding the single yarn. A more preferable range is 15 to 25% by mass.

含水率は、例えば噴霧法であれば処理液の噴霧量で調節することが出来るし、浸漬法であればニップロールによる絞りで調節することが出来るし、タッチロール法であれば炭素化繊維束または表面処理済炭素繊維束の１束当たりの張力や、タッチロールへの接触長で調節することができる。 The water content can be adjusted by, for example, the spray amount of the treatment liquid in the spray method, can be adjusted by drawing with a nip roll in the immersion method, or the carbonized fiber bundle or the touch roll method. It can be adjusted by the tension per bundle of surface-treated carbon fiber bundles and the contact length with the touch roll.

また、処理液を含ませた後の炭素化繊維束または表面処理済炭素繊維束は、乾燥処理を施しても良いが、炭素化繊維束に処理液を含ませる場合であれば、乾燥処理は電解酸化処理工程の直前で、表面処理済炭素繊維束に処理液を含ませる場合であれば、乾燥処理はサイジング処理工程の直前で実施するのが好ましい。乾燥処理の方法は、ロール乾燥、熱風乾燥および輻射熱乾燥など公知のいずれの技術も採用できる。 Further, the carbonized fiber bundle or the surface-treated carbon fiber bundle after being soaked in the treatment liquid may be subjected to a drying treatment, but if the carbonized fiber bundle is to be contained in the treatment liquid, the drying treatment may be performed. If the surface-treated carbon fiber bundle is to be impregnated with the treatment liquid immediately before the electrolytic oxidation treatment step, the drying treatment is preferably carried out immediately before the sizing treatment step. As the drying treatment method, any known technique such as roll drying, hot air drying and radiant heat drying can be adopted.

以下、本発明を、実施例に基づいて具体的に説明するが、本発明はこれらによって限定
されるものではない。 Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited thereto.

（処理液の調整）
ライオン（株）製「レオソルブ７０３Ｂ」（製品名、ポリオキシエチレンポリオキシプロピレンモノブチルエーテル）６０質量部、ライオン（株）製「ライオノールＬ−５３５」（製品名、ポリオキシエチレンポリオキシプロピレンアルキルエーテル）１５質量部、ライオン（株）製「レオコールＳＣ−５０」（製品名、ポリオキシエチレンアルキルエーテル）２５質量部を混合・攪拌し、混合物Ａとした。１質量部の混合物Ａに対し、純水を９９質量部加え均一になるまで攪拌して、混合物Ａを１質量％含有する処理液（以下、「処理液Ａ」と称する）を得た。 (Adjustment of treatment liquid)
60 parts by mass of "Leosolve 703B" (product name, polyoxyethylene polyoxypropylene monobutyl ether) manufactured by Lion Co., Ltd., "Lionol L-535" (product name, polyoxyethylene polyoxypropylene alkyl ether) manufactured by Lion Co., Ltd. 15 parts by mass and 25 parts by mass of "Leocol SC-50" (product name, polyoxyethylene alkyl ether) manufactured by Lion Co., Ltd. were mixed and stirred to obtain a mixture A. 99 parts by mass of pure water was added to 1 part by mass of the mixture A and stirred until uniform to obtain a treatment liquid containing 1% by mass of the mixture A (hereinafter, referred to as “treatment liquid A”).

（表面張力の測定）
処理液Ａの表面張力を自動表面張力計（商品名：ＣＢＶＰ−Ａ３型、協和界面科学製）を用いて、白金製プレートを用いたウイルヘルミー法により２５℃の条件下で測定したところ、２９．５ｍＮ／ｍであった。同様にイオン交換水の表面張力を測定したところ７２．３ｍＮ／ｍであった。 (Measurement of surface tension)
The surface tension of the treatment liquid A was measured under the condition of 25 ° C. by the Wilhelmy method using a platinum plate using an automatic surface tension meter (trade name: CBVP-A3 type, manufactured by Kyowa Interface Science). It was 5 mN / m. Similarly, the surface tension of the ion-exchanged water was measured and found to be 72.3 mN / m.

（炭素繊維束製造工程における繊維束の集束状態、毛羽の観察）
表面処理工程直前、およびサイジング処理工程直前に配置されたローラー間の繊維束を観察し、繊維束に乱れがなく集束状態が良好な場合は、「○・・・乱れなし」と、
繊維束に乱れがあり集束状態が良好ではない場合は、「×・・・乱れあり」と判定した。
また、その際に毛羽の有無を観察し、
毛羽が観察されない場合は、「○・・毛羽なし」と、
毛羽が観察される場合は、「×・・・毛羽あり」と判定した。 (Observation of fiber bundle focusing state and fluff in carbon fiber bundle manufacturing process)
Observe the fiber bundles between the rollers arranged immediately before the surface treatment process and immediately before the sizing treatment process, and if the fiber bundles are not disturbed and the focused state is good, "○ ... no disturbance" is displayed.
When the fiber bundle was disturbed and the focused state was not good, it was judged as "x ... disordered".
At that time, observe the presence or absence of fluff and
If no fluff is observed, say "○ ... no fluff"
When fluff was observed, it was judged as "x ... with fluff".

（毛羽本数の測定）
サイジング剤付き炭素繊維束１ｍを負荷がかからないように巻出し、繊維束に対して９．８Ｎの荷重を掛けて１対のスタンド１に固定した（図１）。毛羽本数の測定は暗室にて行い、スタンド１に固定したサイジング剤付き炭素繊維束をライトで照らした際の、毛羽からの光の反射、および毛羽の先端部分を目視にて確認し、サイジング剤付き炭素繊維束１ｍの毛羽の発生本数を計数した。この測定を１０回行い、その平均値をサイジング剤付き炭素繊維束１ｍあたりの毛羽本数とした。 (Measurement of fluff number)
A 1 m carbon fiber bundle with a sizing agent was unwound so as not to apply a load, and a load of 9.8 N was applied to the fiber bundle and fixed to a pair of stands 1 (FIG. 1). The number of fluffs is measured in a dark room, and when the carbon fiber bundle with a sizing agent fixed to the stand 1 is illuminated with a light, the reflection of light from the fluffs and the tip of the fluffs are visually confirmed, and the sizing agent is used. The number of fluffs generated in the attached carbon fiber bundle of 1 m was counted. This measurement was performed 10 times, and the average value was taken as the number of fluffs per 1 m of carbon fiber bundle with a sizing agent.

（処理液Ａを含ませた場合の含水率の測定）
処理液を含ませた炭素化繊維束または表面処理済炭素繊維束を１００℃で１０分間、加熱・乾燥して水分を除去した後の繊維束の質量（Ｍ１）を測定した。その繊維束をメチルエチルケトンを用いたソックスレー抽出法（抽出時間は１時間）により処理し、繊維束から混合物Ａを除去した。次いで、この混合物Ａが除去された繊維束を１００℃で１０分間、加熱・乾燥し、メチルエチルケトンを除去した後の繊維束の質量（Ｍ２）を測定して、下記式により含水率（％）を算出した。
含水率（％）＝（Ｍ１−Ｍ２）／Ｍ１×（９９／１）×１００
式中の（９９／１）は処理液Ａの「水／混合物Ａ」の質量比である。 (Measurement of water content when treatment liquid A is included)
The mass (M1) of the carbonized fiber bundle or the surface-treated carbon fiber bundle containing the treatment liquid was measured after heating and drying at 100 ° C. for 10 minutes to remove water. The fiber bundle was treated by a Soxhlet extraction method using methyl ethyl ketone (extraction time was 1 hour), and the mixture A was removed from the fiber bundle. Next, the fiber bundle from which the mixture A was removed was heated and dried at 100 ° C. for 10 minutes, and the mass (M2) of the fiber bundle after removing the methyl ethyl ketone was measured, and the water content (%) was determined by the following formula. Calculated.
Moisture content (%) = (M1-M2) / M1 x (99/1) x 100
(99/1) in the formula is the mass ratio of "water / mixture A" of the treatment liquid A.

（イオン交換水を含ませた場合の含水率の測定）
処理液Ａを用いずイオン交換水のみを付与した場合は、イオン交換水を含ませた炭素化繊維束または表面処理済炭素繊維束の質量（Ｍ３）を測定し、その繊維束を１００℃で１０分間加熱・乾燥して水分を除去した後の繊維束の質量（Ｍ４）を測定して、下記式により含水率（％）を算出した。
含水率（％）＝（Ｍ３−Ｍ４）／Ｍ３×１００ (Measurement of water content when ion-exchanged water is included)
When only ion-exchanged water was applied without using the treatment liquid A, the mass (M3) of the carbonized fiber bundle or the surface-treated carbon fiber bundle containing the ion-exchanged water was measured, and the fiber bundle was placed at 100 ° C. The mass (M4) of the fiber bundle after heating and drying for 10 minutes to remove water was measured, and the water content (%) was calculated by the following formula.
Moisture content (%) = (M3-M4) / M3 × 100

（実施例１）
アクリロニトリル、アクリルアミド、及びメタクリル酸を、過硫酸アンモニウム−亜硫酸水素アンモニウムおよび硫酸鉄の存在下、水系懸濁重合により共重合し、アクリロニトリル単位／アクリルアミド単位／メタクリル酸単位＝９６／３／１（質量比）からなるアクリロニトリル系重合体を得た。得られたアクリロニトリル系重合体をジメチルアセトアミドに溶解し、２１質量％の紡糸原液を調製した。得られた紡糸原液を孔数６００００、孔直径４５μｍの紡糸口金（紡糸ノズル）を通して、濃度６０質量％、温度３５℃のジメチルアセトアミド水溶液からなる凝固浴中に吐出させ、紡糸原液の吐出線速度の０．３８倍の引取り速度で引き取ることで繊維束（膨潤糸条）を得た。続いて前記繊維束に対して、水洗と同時に５．３倍の延伸を行い、さらに１．５質量％に調製したアミノシリコン系油剤の第一油浴槽に導き第一油剤を付与し、ガイドで一旦絞りを行った後、引き続き第二油浴槽で第二油剤を付与した。引き続き、熱ロールを用いて繊維束を乾燥し、熱ロール間で１．５倍の二次延伸を施した。その後、タッチロールを用いて繊維束の含水率を調整し、単繊維繊度１ｄｔｅｘの炭素繊維前駆体アクリル繊維束を得た。 (Example 1)
Acrylonitrile, acrylamide, and methacrylic acid are copolymerized by aqueous suspension polymerization in the presence of ammonium persulfate-ammonium hydrogen sulfite and iron sulfate, and acrylonitrile unit / acrylamide unit / methacrylic acid unit = 96/3/1 (mass ratio). An acrylonitrile-based polymer composed of the above was obtained. The obtained acrylonitrile-based polymer was dissolved in dimethylacetamide to prepare a spinning stock solution of 21% by mass. The obtained undiluted spinning solution is discharged into a coagulation bath consisting of a dimethylacetamide aqueous solution having a concentration of 60% by mass and a temperature of 35 ° C. through a spinning mouthpiece (spinning nozzle) having a hole number of 60,000 and a hole diameter of 45 μm. A fiber bundle (swelling thread) was obtained by picking up at a pick-up speed of 0.38 times. Subsequently, the fiber bundle was washed with water and stretched 5.3 times at the same time, and further guided to a first oil bath of an aminosilicon-based oil prepared to 1.5% by mass to apply the first oil, and a guide was used. After squeezing once, the second oil agent was continuously applied in the second oil bath. Subsequently, the fiber bundles were dried using a heat roll and subjected to 1.5 times secondary stretching between the heat rolls. Then, the water content of the fiber bundle was adjusted using a touch roll to obtain a carbon fiber precursor acrylic fiber bundle having a single fiber fineness of 1 dtex.

得られた炭素繊維前駆体アクリル繊維束を、酸化性雰囲気下で、２２０℃〜２７０℃で６０分、伸長率−６％で連続的に耐炎化処理を行い、密度１．３５ｇ／ｃｍ３の耐炎化繊維束を得た。続いて３００〜７００℃の温度分布を有し、窒素雰囲気とした炭素化炉中にて伸長率＋３％、繊維束１束当たり３５Ｎの張力を付しながら、１．０分間の炭素化処理を行った。続いて最高温度１３５０℃、窒素雰囲気とした炭素化炉中にて、伸長率−３．８％、繊維束１束当たり８０Ｎの張力を付し、１．０分間の炭素化処理を行うことにより、炭素繊化維束を得た。 The obtained carbon fiber precursor acrylic fiber bundle was continuously flame-resistant at 220 ° C. to 270 ° C. for 60 minutes at an elongation rate of -6% in an oxidizing atmosphere, and flame-resistant at a density of 1.35 g / cm3. A synthetic fiber bundle was obtained. Subsequently, carbonization treatment was carried out for 1.0 minute in a carbonization furnace having a temperature distribution of 300 to 700 ° C. and a nitrogen atmosphere while applying an elongation rate of + 3% and a tension of 35 N per fiber bundle. went. Subsequently, in a carbonization furnace having a maximum temperature of 1350 ° C. and a nitrogen atmosphere, an elongation rate of -3.8% and a tension of 80 N per fiber bundle were applied, and carbonization treatment was performed for 1.0 minute. , A carbon fasciculation bundle was obtained.

続いて、得られた炭素化繊維束に、図２に示した装置を用いて処理液Ａを含ませた。このとき炭素化繊維束には繊維束１束当たり３０Ｎの張力を付し、含水率が１０質量％になるように接触ローラーとの接触長を調整した。 Subsequently, the obtained carbonized fiber bundle was impregnated with the treatment liquid A using the apparatus shown in FIG. At this time, a tension of 30 N was applied to the carbonized fiber bundles per fiber bundle, and the contact length with the contact roller was adjusted so that the water content was 10% by mass.

続いて、この炭素化繊維束を電解酸化処理し表面処理済炭素繊維束を得て、イオン交換水により洗浄し、周面が１５０℃に加熱されたローラーの周面に繊維束を接触させて乾燥した。 Subsequently, the carbonized fiber bundle is electrolyzed to obtain a surface-treated carbon fiber bundle, washed with ion-exchanged water, and the fiber bundle is brought into contact with the peripheral surface of a roller whose peripheral surface is heated to 150 ° C. It was dry.

続いて、この乾燥した表面処理済炭素繊維束を、１．８質量％に調製したエポキシ樹脂を主成分とするサイジング剤の水分散液で満たした処理槽に導き、ガイドで一旦絞りを行った後、周面が１５０℃に加熱されたローラーの周面に繊維束を接触させて乾燥し、サイジング剤付き炭素繊維束を得た後、サイジング剤付き炭素繊維束をボビンに巻き取った。なお、表面処理工程直前、およびサイジング処理工程直前に配置されたローラー間の繊維束を観察した結果、および得られたサイジング剤付き炭素繊維束の毛羽本数の測定結果を、表１に示す。 Subsequently, the dried surface-treated carbon fiber bundle was guided to a treatment tank filled with an aqueous dispersion of a sizing agent containing an epoxy resin as a main component prepared to 1.8% by mass, and once squeezed with a guide. After that, the fiber bundle was brought into contact with the peripheral surface of the roller whose peripheral surface was heated to 150 ° C. and dried to obtain a carbon fiber bundle with a sizing agent, and then the carbon fiber bundle with a sizing agent was wound around a bobbin. Table 1 shows the results of observing the fiber bundles between the rollers arranged immediately before the surface treatment step and immediately before the sizing treatment step, and the measurement results of the number of fluffs of the obtained carbon fiber bundles with a sizing agent.

（実施例２）
処理液Ａを含ませた炭素化繊維束の含水率を３０質量％としたこと以外は、実施例１と同様な方法でサイジング剤付き炭素繊維束を得た。表面処理工程直前、およびサイジング処理工程直前に配置されたローラー間の繊維束を観察した結果、および得られたサイジング剤付き炭素繊維束の毛羽本数の測定結果を、表１に示す。 (Example 2)
A carbon fiber bundle with a sizing agent was obtained in the same manner as in Example 1 except that the water content of the carbonized fiber bundle containing the treatment liquid A was 30% by mass. Table 1 shows the results of observing the fiber bundles between the rollers arranged immediately before the surface treatment step and immediately before the sizing treatment step, and the measurement results of the number of fluffs of the obtained carbon fiber bundles with a sizing agent.

（実施例３）
炭素化繊維束に処理液Ａを含ませる操作をせず、炭素化繊維束の電解酸化処理を行い、得られた表面処理済炭素繊維束を乾燥した後に、処理液Ａの含水率が１０質量％となるように、タッチロール方式で含ませた表面処理済み炭素繊維束をサイジング処理すること以外は実施例１と同様にしてサイジング剤付き炭素繊維束を得た。表面処理工程直前、およびサイジング処理工程直前に配置されたローラー間の繊維束を観察した結果、および得られたサイジング剤付き炭素繊維束の毛羽本数の測定結果を、表１に示す。 (Example 3)
The carbonized fiber bundle was subjected to electrolytic oxidation treatment without the operation of including the treatment liquid A in the carbonized fiber bundle, and after the obtained surface-treated carbon fiber bundle was dried, the water content of the treated liquid A was 10 mass by mass. A carbon fiber bundle with a sizing agent was obtained in the same manner as in Example 1 except that the surface-treated carbon fiber bundle contained in the touch roll method was sized so as to be%. Table 1 shows the results of observing the fiber bundles between the rollers arranged immediately before the surface treatment step and immediately before the sizing treatment step, and the measurement results of the number of fluffs of the obtained carbon fiber bundles with a sizing agent.

（実施例４）
処理液Ａを含ませた表面処理済炭素繊維束の含水率を３０質量％としたこと以外は、実施例３と同様な方法でサイジング剤付き炭素繊維束を得た。表面処理工程直前、およびサイジング処理工程直前に配置されたローラー間の繊維束を観察した結果、および得られたサイジング剤付き炭素繊維束の毛羽本数の測定結果を、表１に示す。 (Example 4)
A carbon fiber bundle with a sizing agent was obtained in the same manner as in Example 3 except that the water content of the surface-treated carbon fiber bundle containing the treatment liquid A was 30% by mass. Table 1 shows the results of observing the fiber bundles between the rollers arranged immediately before the surface treatment step and immediately before the sizing treatment step, and the measurement results of the number of fluffs of the obtained carbon fiber bundles with a sizing agent.

（実施例５）
炭素化繊維束に含水率が１０質量％となるように、処理液Ａをタッチロール方式で含ませさらに炭素化繊維束の電解酸化処理を行い、得られた表面処理済炭素繊維束を乾燥した後に、処含水率が１０質量％となるように、処理液Ａをタッチロール方式で含ませた表面処理済み炭素繊維束をサイジング処理すること以外は実施例１と同様にしてサイジング剤付き炭素繊維束を得た。表面処理工程直前、およびサイジング処理工程直前に配置されたローラー間の繊維束を観察した結果、および得られたサイジング剤付き炭素繊維束の毛羽本数の測定結果を、表１に示す。 (Example 5)
The treatment liquid A was added by a touch roll method so that the carbonized fiber bundle had a water content of 10% by mass, and the carbonized fiber bundle was further subjected to electrolytic oxidation treatment, and the obtained surface-treated carbon fiber bundle was dried. Later, the carbon fiber with a sizing agent is sizing in the same manner as in Example 1 except that the surface-treated carbon fiber bundle containing the treatment liquid A by the touch roll method is sized so that the treated water content is 10% by mass. I got a bunch. Table 1 shows the results of observing the fiber bundles between the rollers arranged immediately before the surface treatment step and immediately before the sizing treatment step, and the measurement results of the number of fluffs of the obtained carbon fiber bundles with a sizing agent.

（比較例１）
炭素化繊維束に処理液Ａを含ませず水分を含まない炭素化繊維束を電解処理槽内の電解液に導いて電解酸化処理をすること以外は、実施例１と同様にしてサイジング剤付き炭素繊維束を得た。表面処理工程直前、およびサイジング処理工程直前に配置されたローラー間の繊維束を観察した結果、および得られたサイジング剤付き炭素繊維束の毛羽本数の測定結果を、表１に示す。 (Comparative Example 1)
A sizing agent is added in the same manner as in Example 1 except that the carbonized fiber bundle does not contain the treatment liquid A and does not contain water, and the carbonized fiber bundle is guided to the electrolytic solution in the electrolytic treatment tank to perform electrolytic oxidation treatment. A carbon fiber bundle was obtained. Table 1 shows the results of observing the fiber bundles between the rollers arranged immediately before the surface treatment step and immediately before the sizing treatment step, and the measurement results of the number of fluffs of the obtained carbon fiber bundles with a sizing agent.

（比較例２）
処理液Ａを含ませた炭素化繊維束の含水率を５質量％としたこと以外は、実施例１と同様な方法でサイジング剤付き炭素繊維束を得た。表面処理工程直前、およびサイジング処理工程直前に配置されたローラー間の繊維束を観察した結果、および得られたサイジング剤付き炭素繊維束の毛羽本数の測定結果を、表１に示す。 (Comparative Example 2)
A carbon fiber bundle with a sizing agent was obtained in the same manner as in Example 1 except that the water content of the carbonized fiber bundle containing the treatment liquid A was 5% by mass. Table 1 shows the results of observing the fiber bundles between the rollers arranged immediately before the surface treatment step and immediately before the sizing treatment step, and the measurement results of the number of fluffs of the obtained carbon fiber bundles with a sizing agent.

（比較例３）
処理液Ａを含ませた表面処理済み炭素繊維束の含水率を５質量％としたこと以外は、実施例３と同様な方法でサイジング剤付き炭素繊維束を得た。表面処理工程直前、およびサイジング処理工程直前に配置されたローラー間の繊維束を観察した結果、および得られたサイジング剤付き炭素繊維束の毛羽本数の測定結果を、表１に示す。 (Comparative Example 3)
A carbon fiber bundle with a sizing agent was obtained in the same manner as in Example 3 except that the water content of the surface-treated carbon fiber bundle containing the treatment liquid A was 5% by mass. Table 1 shows the results of observing the fiber bundles between the rollers arranged immediately before the surface treatment step and immediately before the sizing treatment step, and the measurement results of the number of fluffs of the obtained carbon fiber bundles with a sizing agent.

（比較例４）
処理液を含ませる方法として、図３に示す浸漬法を採用し、処理液Ａを含ませた炭素化繊維束の含水率を５０質量％としたこと以外は、実施例１と同様な方法でサイジング剤付き炭素繊維束を得た。炭素化繊維束の集束状態は十分に維持できていたものの、処理液を含ませた後に設置したローラーが処理液で汚染され、また繊維束には毛羽が散見された。表面処理工程直前、およびサイジング処理工程直前に配置されたローラー間の繊維束を観察した結果、および得られたサイジング剤付き炭素繊維束の毛羽本数の測定結果を、表１に示す。 (Comparative Example 4)
As a method of impregnating the treatment liquid, the dipping method shown in FIG. 3 was adopted, and the same method as in Example 1 was used except that the water content of the carbonized fiber bundle containing the treatment liquid A was 50% by mass. A carbon fiber bundle with a sizing agent was obtained. Although the focused state of the carbonized fiber bundles could be sufficiently maintained, the rollers installed after the treatment liquid was soaked were contaminated with the treatment liquid, and fluff was scattered on the fiber bundles. Table 1 shows the results of observing the fiber bundles between the rollers arranged immediately before the surface treatment step and immediately before the sizing treatment step, and the measurement results of the number of fluffs of the obtained carbon fiber bundles with a sizing agent.

（比較例５）
処理液Ａの代わりにイオン交換水（表面張力７２．３）を用い、イオン交換水を５質量％含んだ炭素化繊維束を電解処理槽内の電解液に導いて電解酸化処理をすること以外は実施例１と同様な方法でサイジング剤付き炭素繊維束を得た。
炭素化繊維束の集束状態を十分に維持できず、単繊維のばらけが発生し、毛羽も散見された。表面処理工程直前、およびサイジング処理工程直前に配置されたローラー間の繊維束を観察した結果、および得られたサイジング剤付き炭素繊維束の毛羽本数の測定結果を、表１に示す。 (Comparative Example 5)
Except for using ion-exchanged water (surface tension 72.3) instead of the treatment liquid A and guiding the carbonized fiber bundle containing 5% by mass of the ion-exchanged water to the electrolytic liquid in the electrolytic treatment tank for electrolytic oxidation treatment. Obtained a carbon fiber bundle with a sizing agent in the same manner as in Example 1.
The focused state of the carbonized fiber bundle could not be sufficiently maintained, the single fibers were scattered, and fluff was also scattered. Table 1 shows the results of observing the fiber bundles between the rollers arranged immediately before the surface treatment step and immediately before the sizing treatment step, and the measurement results of the number of fluffs of the obtained carbon fiber bundles with a sizing agent.

（比較例６）
処理液Ａの代わりにイオン交換水を用い、炭素化繊維束にイオン交換水を含ませる方法として、図３に示すような浸漬法を採用し、イオン交換水を５０質量％含んだ炭素化繊維束を電解処理槽内の電解液に導いて電解酸化処理をすること以外は、実施例１と同様な方法でサイジング剤付き炭素繊維束を得た。炭素化繊維束の集束状態は十分に維持できていたものの、イオン交換水を含ませた後に設置したローラーが汚染され、また繊維束には毛羽が散見された。表面処理工程直前、およびサイジング処理工程直前に配置されたローラー間の繊維束を観察した結果、および得られたサイジング剤付き炭素繊維束の毛羽本数の測定結果を、表１に示す。 (Comparative Example 6)
As a method of using ion-exchanged water instead of the treatment liquid A and including the ion-exchanged water in the carbonized fiber bundle, the immersion method as shown in FIG. 3 is adopted, and the carbonized fiber containing 50% by mass of the ion-exchanged water is adopted. A carbon fiber bundle with a sizing agent was obtained in the same manner as in Example 1 except that the bundle was guided to the electrolytic solution in the electrolytic treatment tank and subjected to electrolytic oxidation treatment. Although the focused state of the carbonized fiber bundle was sufficiently maintained, the rollers installed after soaking in ion-exchanged water were contaminated, and fluff was scattered on the fiber bundle. Table 1 shows the results of observing the fiber bundles between the rollers arranged immediately before the surface treatment step and immediately before the sizing treatment step, and the measurement results of the number of fluffs of the obtained carbon fiber bundles with a sizing agent.

表１に示すように、実施例１〜５のサイジング剤付き炭素繊維束は、炭素繊維束、および表面処理済炭素繊維束に処理液Ａが十分に浸透し、炭素繊維束の集束状態が十分に維持されたために、毛羽本数が、いずれ、５本／ｍ以下となった。一方で、処理液を付与しなかった比較例１のサイジング剤付き炭素繊維束は、炭素化繊維束や表面処理済み炭素繊維束の集束状態を十分に維持することができず、単繊維のばらけが発生し、結果的に毛羽が多く観察された。比較例２~３、および比較例５のサイジング剤付き炭素繊維束は、炭素化繊維束もしくは表面処理済み炭素繊維束部に含ませた処理液の含水率が十分でなかったために、炭素化繊維束や表面処理済み炭素繊維束の集束状態を十分に維持することができず、単繊維のばらけが発生し、結果的に毛羽が多く観察された。比較例４および比較例６のサイジング剤付き炭素繊維束は、炭素化繊維束に含ませた処理液の含水率が５０％質量となったために、炭素化繊維束の集束状態を十分に維持することは出来たものの、処理液を含ませた後に設置したローラーが処理液で汚染され、結果的に毛羽が多く観察された。 As shown in Table 1, in the carbon fiber bundles with the sizing agent of Examples 1 to 5, the treatment liquid A sufficiently permeates the carbon fiber bundles and the surface-treated carbon fiber bundles, and the carbon fiber bundles are sufficiently focused. The number of fluffs was eventually reduced to 5 / m or less. On the other hand, the carbon fiber bundle with the sizing agent of Comparative Example 1 to which the treatment liquid was not applied could not sufficiently maintain the focused state of the carbonized fiber bundle and the surface-treated carbon fiber bundle, and the single fibers were separated. Injuries occurred, and as a result, many fluffs were observed. The carbon fiber bundles with the sizing agent of Comparative Examples 2 to 3 and Comparative Example 5 were carbonized fibers because the water content of the treatment liquid contained in the carbonized fiber bundles or the surface-treated carbon fiber bundles was not sufficient. It was not possible to sufficiently maintain the focused state of the bundles and the surface-treated carbon fiber bundles, and the single fibers were scattered, and as a result, many fluffs were observed. The carbon fiber bundles with the sizing agent of Comparative Example 4 and Comparative Example 6 sufficiently maintain the focused state of the carbonized fiber bundles because the water content of the treatment liquid contained in the carbonized fiber bundles is 50% by mass. Although this was possible, the rollers installed after the treatment liquid was soaked were contaminated with the treatment liquid, and as a result, many fluffs were observed.

１スタンド
ａスタンドの間隔（１ｍを標準とする）
２サイジング剤付き炭素繊維束
３サイジング剤付き炭素繊維束を巻き取ったボビン
４おもり（繊維束１本に対して９．８Ｎ）
５炭素化繊維束、もしくは表面処理済み炭素繊維束
６処理液槽
７処理液
８タッチローラーまたは浸漬ローラー 1 Stand a Stand spacing (1 m is standard)
2 Carbon fiber bundle with sizing agent 3 Bobbin wound with carbon fiber bundle with sizing agent 4 Weight (9.8N per fiber bundle)
5 Carbonized fiber bundle or surface-treated carbon fiber bundle 6 Treatment liquid tank 7 Treatment liquid 8 Touch roller or immersion roller

Claims

耐炎化繊維束を炭素化炉に導入し不活性雰囲気下で加熱処理して炭素化繊維束とする工程と、次いで前記炭素化繊維束を電解酸化処理し表面処理済炭素繊維束とする工程と、次いで前記表面処理済炭素繊維束をサイジング処理しサイジング剤付き炭素繊維束とする工程とを含む、サイジング剤付き炭素繊維束の製造方法であって、前記炭素化繊維束を電解酸化処理する前に、表面張力が６０ｍＮ／ｍ以下の水溶液を前記炭素化繊維束に、含水率１０〜２０％の範囲で含ませることを含ませる、サイジング剤付き炭素繊維束の製造方法。 A step of introducing the flame-resistant fiber bundle into a carbonization furnace and heat-treating it in an inert atmosphere to obtain a carbonized fiber bundle, and then a step of electrolytically oxidizing the carbonized fiber bundle to obtain a surface-treated carbon fiber bundle. A method for producing a carbon fiber bundle with a sizing agent, which comprises a step of sizing the surface-treated carbon fiber bundle to obtain a carbon fiber bundle with a sizing agent, and before electrolytically oxidizing the carbonized fiber bundle. A method for producing a carbon fiber bundle with a sizing agent, which comprises including an aqueous solution having a surface tension of 60 mN / m or less in the carbonized fiber bundle in a water content range of 10 to 20%.

耐炎化繊維束を炭素化炉に導入し不活性雰囲気下で加熱処理して炭素化繊維束とする工程と、次いで前記炭素化繊維束を電解酸化処理し表面処理済炭素繊維束とする工程と、次いで前記表面処理済炭素繊維束をサイジング処理しサイジング剤付き炭素繊維束とする工程とを含む、サイジング剤付き炭素繊維束の製造方法であって、前記表面処理済炭素繊維束をサイジング処理する前に、表面張力が６０ｍＮ／ｍ以下の水溶液を前記表面処理済炭素繊維束に含水率１０〜２０％の範囲で含ませる、サイジング剤付き炭素繊維束の製造方法。 A step of introducing the flame-resistant fiber bundle into a carbonization furnace and heat-treating it in an inert atmosphere to form a carbonized fiber bundle, and then a step of electrolytically oxidizing the carbonized fiber bundle to obtain a surface-treated carbon fiber bundle. A method for producing a carbon fiber bundle with a sizing agent, which comprises a step of sizing the surface-treated carbon fiber bundle to obtain a carbon fiber bundle with a sizing agent, wherein the surface-treated carbon fiber bundle is sizing-treated. A method for producing a carbon fiber bundle with a sizing agent, wherein an aqueous solution having a surface tension of 60 mN / m or less is previously included in the surface-treated carbon fiber bundle in a water content range of 10 to 20%.

前記表面張力が６０ｍＮ／ｍ以下の水溶液として、界面活性剤を含有する水溶液を用いる、請求項１または２に記載のサイジング剤付き炭素繊維束の製造方法。 The method for producing a carbon fiber bundle with a sizing agent according to claim 1 or 2, wherein an aqueous solution containing a surfactant is used as the aqueous solution having a surface tension of 60 mN / m or less.