JP2010111957A - Carbon fiber, composite material, and method for producing carbon fiber - Google Patents
Carbon fiber, composite material, and method for producing carbon fiber Download PDFInfo
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- 239000001301 oxygen Substances 0.000 claims abstract description 12
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- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 abstract description 2
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- 238000010438 heat treatment Methods 0.000 description 4
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- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 description 3
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- JAHNSTQSQJOJLO-UHFFFAOYSA-N 2-(3-fluorophenyl)-1h-imidazole Chemical compound FC1=CC=CC(C=2NC=CN=2)=C1 JAHNSTQSQJOJLO-UHFFFAOYSA-N 0.000 description 2
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
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Abstract
Description
本発明は、航空機用等の複合材料に好適に使用される炭素繊維と、それを用いた複合材料に関する。 The present invention relates to a carbon fiber suitably used for a composite material for aircraft and the like, and a composite material using the carbon fiber.
近年、炭素繊維を強化繊維として用いた複合材料は、軽く、高強度等の優れた機械的特性を有するので、航空機等の複合材料として多く用いられてきている。これらの複合材料は、例えば、強化繊維にマトリックス樹脂が含浸された中間製品であるプリプレグから、加熱・加圧といった成形・加工工程を経て成形される。従って、所望の複合材料を得るためには、それぞれに最適の材料あるいは成形・加工手段を採用する必要があり、強化繊維である炭素繊維にも色々な特性が要求される。 In recent years, composite materials using carbon fibers as reinforcing fibers are light and have excellent mechanical properties such as high strength, and thus have been widely used as composite materials for aircraft and the like. These composite materials are molded, for example, from a prepreg, which is an intermediate product in which a reinforcing fiber is impregnated with a matrix resin, through molding and processing steps such as heating and pressing. Therefore, in order to obtain a desired composite material, it is necessary to adopt an optimum material or molding / processing means for each, and various properties are also required for carbon fibers which are reinforcing fibers.
例えば、炭素繊維を３０００本(３ｋ)乃至５００００本(５０ｋ)程度束ねて炭素繊維ストランドを製造する場合、ストランドは伸度が低く、機械的摩擦などによって毛羽が発生し易い。このため、炭素繊維ストランドにサイズ剤として樹脂を付与することにより、炭素繊維ストランドの集束性を向上させて取扱性を改善させるのが一般的である。炭素繊維ストランドへのサイズ剤付与については、これまでに多くの提案がなされている(例えば、特許文献１、２)。
航空機を始めとする各種用途に用いられる複合材料には、より一層の物性向上が求められている。特に、耐熱性、耐衝撃性、靱性などの特性を満たすため、樹脂については、一般的に、より高粘度の樹脂が使用される傾向がある。 Further improvements in physical properties are required for composite materials used in various applications including aircraft. In particular, in order to satisfy characteristics such as heat resistance, impact resistance, and toughness, generally, resins having higher viscosity tend to be used.
しかし、高粘度の樹脂が使用される場合は、炭素繊維ストランド内部への樹脂の含浸性が低下する。その結果、得られる複合材料は、その内部で剥離等が生じやすくなる。 However, when a highly viscous resin is used, the impregnation property of the resin into the carbon fiber strand is lowered. As a result, the obtained composite material is likely to be peeled off.
本発明者は、上記問題を解決するために種々検討しているうちに、炭素繊維について、複合化前における炭素繊維自体の形態、界面状態(例えば、ストランド弾性率、表面酸素濃度比Ｏ／Ｃ、サイズ剤付着量、張力下のストランド幅広がり性、動的測定による初期濡れ性)を、上記高粘度の樹脂に合わせて選択することにより、上記炭素繊維のストランドと高粘度の樹脂とが複合されてなる複合材料の剥離の発生を抑制できることを見出した。 While the present inventor has made various studies in order to solve the above problems, regarding the carbon fiber, the form of the carbon fiber itself before the composite, the interface state (for example, strand elastic modulus, surface oxygen concentration ratio O / C) The carbon fiber strand and the high-viscosity resin are combined by selecting the sizing agent adhesion amount, strand width spreadability under tension, and initial wettability by dynamic measurement) according to the high-viscosity resin. It has been found that the occurrence of peeling of the composite material formed can be suppressed.
また、このように選択して製造される複合材料は、有孔引張り強度(ＯＨＴ)及びＯＨＴ測定における剥離発生時の強度を高くできることを見出した。 Further, it has been found that the composite material selected and manufactured in this way can increase the perforated tensile strength (OHT) and the strength at the time of delamination in OHT measurement.
更に、上記炭素繊維の製造に際しては、原料炭素繊維ストランドをローラーを用いて二段開繊することにより、サイズ剤を均一に付与でき、ＯＨＴ測定時に剥離し難い炭素繊維を製造できることを見出し、本発明を完成するに到った。 Furthermore, in the production of the above carbon fiber, it has been found that the carbon fiber strands can be uniformly applied by opening the raw carbon fiber strands using a roller, and carbon fibers that are difficult to peel off during OHT measurement can be produced. The invention has been completed.
よって、本発明の目的とするところは、上記問題を解決した炭素繊維、複合材料及び炭素繊維の製造方法を提供することにある。 Accordingly, an object of the present invention is to provide a carbon fiber, a composite material, and a carbon fiber manufacturing method that solve the above-described problems.
上記目的を達成する本発明は、以下に記載のものである。 The present invention for achieving the above object is as follows.
［１］ ストランド弾性率が２９０〜３５０ＧＰａ、表面酸素濃度比Ｏ／Ｃが１０〜２５％、サイズ剤付着量が０．４〜１．７質量％、張力下のストランド幅広がり性が１３５ｔｅｘ／ｍｍ以下であり、動的測定による初期濡れ性Ａ(ｍＮ／ｔｅｘ)が
−１．３×１０-4 ≧ Ａ ≧ −６．５×１０-4
の範囲である炭素繊維。
[1] Strand elastic modulus is 290 to 350 GPa, surface oxygen concentration ratio O / C is 10 to 25%, sizing agent adhesion amount is 0.4 to 1.7 mass%, and strand width spreading property under tension is 135 tex / mm. The initial wettability A (mN / tex) by dynamic measurement is −1.3 × 10 −4 ≧ A ≧ −6.5 × 10 −4.
Carbon fiber that is in the range of.
［２］ 一方向に並べた［１］に記載の炭素繊維と前記炭素繊維を包埋してなる樹脂とからなる樹脂含浸層と、前記含浸層に含浸されている樹脂で構成される樹脂層とが交互に、且つ、必要により各樹脂含浸層の炭素繊維軸を互いに異ならせて積層されてなる複合材料であって、前記樹脂層の厚み(ａ)と樹脂含浸層の厚み(ｂ)との比[厚み割合(ａ／ｂ)]が２０％以下であり、有孔引張り強度(ＯＨＴ)が４５０ＭＰａ以上であり、前記複合材料のＯＨＴ測定用試験片に荷重を与えてＯＨＴ測定を行う場合に、前記ＯＨＴ測定用試験片が剥離を開始する強度が２５０ＭＰａ以上である複合材料。 [2] A resin impregnated layer composed of the carbon fiber according to [1] arranged in one direction and a resin in which the carbon fiber is embedded, and a resin layer composed of the resin impregnated in the impregnated layer Is a composite material that is laminated alternately and, if necessary, with the carbon fiber axes of each resin-impregnated layer different from each other, wherein the resin layer thickness (a) and the resin-impregnated layer thickness (b) When the ratio [thickness ratio (a / b)] is 20% or less, the perforated tensile strength (OHT) is 450 MPa or more, and an OHT measurement is performed by applying a load to the OHT measurement test piece of the composite material. Further, a composite material having a strength at which the test piece for OHT measurement starts peeling is 250 MPa or more.
［３］ 弾性率２９０〜３５０ＧＰａの炭素繊維からなる原料炭素繊維ストランドを表面酸化処理工程において１５〜９０ｃ／ｇの電気量で電解酸化して表面酸化処理炭素繊維ストランドを得、この表面酸化処理炭素繊維ストランドを水洗後、一段目開繊工程で複数のローラーに接触させて開繊処理し、次いで乾燥処理を行い、さらに二段目開繊工程で複数のローラーに前記乾燥処理後のストランドを接触させて開繊処理した後、サイズ剤濃度１０〜２５質量％のサイジング液に前記二段開繊処理したストランドを通過させてサイズ剤を付与することを特徴とする［１］に記載の炭素繊維の製造方法。 [3] Raw material carbon fiber strands made of carbon fibers having an elastic modulus of 290 to 350 GPa are subjected to electrolytic oxidation with a quantity of electricity of 15 to 90 c / g in a surface oxidation treatment step to obtain surface oxidation treatment carbon fiber strands. After washing the fiber strand with water, it is contacted with a plurality of rollers in the first stage opening process, followed by a drying process, and then a plurality of rollers are contacted with the plurality of rollers in the second stage opening process. The carbon fiber according to [1], wherein after the fiber opening treatment, the sizing solution having a sizing agent concentration of 10 to 25% by mass is passed through the strand subjected to the two-stage fiber opening treatment to give a sizing agent. Manufacturing method.
本発明の炭素繊維は、この炭素繊維のストランドと樹脂とを用いて製造される複合材料の有孔引張り強度(ＯＨＴ)を高く、且つ複合材料の剥離の発生を有効に抑制することができる。 The carbon fiber of the present invention can increase the porous tensile strength (OHT) of a composite material produced using the carbon fiber strand and the resin, and can effectively suppress the occurrence of peeling of the composite material.
以下、本発明を詳細に説明する。 Hereinafter, the present invention will be described in detail.
本発明の炭素繊維は、ストランド弾性率が２９０〜３５０ＧＰａ、好ましくは２９０〜３４５ＧＰａ、表面酸素濃度比Ｏ／Ｃが１０〜２５％、好ましくは１０〜２０％、サイズ剤付着量が０．４〜１．７質量％、好ましくは０．５〜１．５質量％、張力下のストランド幅広がり性が１３５ｔｅｘ／ｍｍ以下、好ましくは７０〜１３０ｔｅｘ／ｍｍ、動的測定による初期濡れ性Ａ(ｍＮ／ｔｅｘ)が
−１．３×１０-4 ≧ Ａ ≧ −６．５×１０-4
の範囲である。
The carbon fiber of the present invention has a strand elastic modulus of 290 to 350 GPa, preferably 290 to 345 GPa, a surface oxygen concentration ratio O / C of 10 to 25%, preferably 10 to 20%, and a sizing agent adhesion amount of 0.4 to 0.4. 1.7% by mass, preferably 0.5 to 1.5% by mass, strand width spreadability under tension of 135 tex / mm or less, preferably 70 to 130 tex / mm, initial wettability A (mN / tex) is −1.3 × 10 −4 ≧ A ≧ −6.5 × 10 −4.
Range.
本発明の複合材料は、一方向に並べた上記炭素繊維と前記炭素繊維を包埋してなる樹脂とからなる樹脂含浸層と、前記含浸層に含浸されている樹脂で構成される樹脂層とが交互に、且つ、必要により各樹脂含浸層の炭素繊維軸を互いに異ならせて積層されてなる複合材料であって、前記樹脂層の厚み(ａ)と樹脂含浸層の厚み(ｂ)との比[厚み割合(ａ／ｂ)]が２０％以下、好ましくは５〜２０％である。厚み割合(ａ／ｂ)は、後述する測定方法で得られる。 The composite material of the present invention includes a resin impregnated layer composed of the carbon fibers arranged in one direction and a resin embedding the carbon fibers, and a resin layer composed of a resin impregnated in the impregnated layer. Is a composite material that is laminated alternately and, if necessary, with the carbon fiber axes of the resin impregnated layers different from each other, and the thickness of the resin layer (a) and the thickness of the resin impregnated layer (b) The ratio [thickness ratio (a / b)] is 20% or less, preferably 5 to 20%. The thickness ratio (a / b) is obtained by a measurement method described later.
炭素繊維の諸物性値が上記範囲にあることにより、炭素繊維に樹脂を含浸させてなる樹脂含浸層と、前記含浸層に含浸されている樹脂で構成される樹脂層とからなる上記複合材料において、ＳＡＣＭＡ ＳＲＭ ５Ｒに従った有孔引張り強度(ＯＨＴ)は４５０ＭＰａ以上、好ましくは４５０〜６５０ＭＰａの範囲になる。この複合材料は、ＯＨＴ測定における剥離発生時の強度が２５０ＭＰａ以上、好ましくは２９０〜６５０ＭＰａの範囲になる。この複合材料は、強度等の物性値を低下させることなく、剥離の発生が少ない。 In the composite material comprising the resin impregnated layer obtained by impregnating carbon fiber with a resin and the resin layer composed of the resin impregnated in the impregnated layer when the physical properties of the carbon fiber are in the above range. The perforated tensile strength (OHT) according to SACMA SRM 5R is 450 MPa or more, preferably 450 to 650 MPa. This composite material has a strength at the time of delamination in the OHT measurement of 250 MPa or more, preferably in the range of 290 to 650 MPa. This composite material is less likely to be peeled off without lowering physical properties such as strength.
本発明の炭素繊維は、例えば、以下の方法により製造することができる。 The carbon fiber of the present invention can be produced, for example, by the following method.
＜前駆体繊維＞
本例の炭素繊維の製造方法に用いる前駆体繊維は、アクリロニトリルを９０質量％以上、好ましくは９５質量％以上含有し、その他の単量体を１０質量％以下含有する単量体を単独又は共重合した紡糸溶液を紡糸して製造する、アクリル系前駆体繊維が好ましい。その他の単量体としてはイタコン酸、(メタ)アクリル酸エステル等が例示される。
<Precursor fiber>
The precursor fiber used in the carbon fiber production method of this example contains 90% by mass or more, preferably 95% by mass or more of acrylonitrile, and a monomer containing 10% by mass or less of other monomers alone or in combination. Acrylic precursor fibers produced by spinning a polymerized spinning solution are preferred. Examples of other monomers include itaconic acid and (meth) acrylic acid esters.
紡糸後の原料繊維を、水洗、乾燥、延伸、オイリング処理することにより、前駆体繊維が得られる。 Precursor fibers are obtained by subjecting the raw fiber after spinning to water washing, drying, stretching, and oiling treatment.
＜耐炎化処理＞
得られた前駆体繊維は、引き続き加熱空気中２００〜２６０℃で耐炎化処理される。この時の処理は、一般的に、延伸倍率０．８５〜１．１５の範囲で処理されるが、高強度・高弾性率の炭素繊維を得るためには、０．９５以上がより好ましい。この耐炎化処理は、前駆体繊維を繊維密度１．３４〜１．３８ｇ／ｃｍ3の酸化された繊維とするものであり、耐炎化時の張力(延伸配分)は特に限定されるものでは無い。
<Flame resistance treatment>
The obtained precursor fiber is subsequently flameproofed at 200 to 260 ° C. in heated air. The treatment at this time is generally carried out in a draw ratio range of 0.85 to 1.15, but 0.95 or more is more preferable in order to obtain a carbon fiber having high strength and high elastic modulus. In this flameproofing treatment, the precursor fibers are oxidized fibers having a fiber density of 1.34 to 1.38 g / cm 3 , and the tension (stretch distribution) at the time of flameproofing is not particularly limited. .
＜第一炭素化処理＞
上記耐炎化繊維は、従来の公知の方法を採用して炭素化することができる。例えば、窒素雰囲気下３００〜８００℃で第一炭素化炉で徐々に温度を高めると共に、耐炎化繊維の張力を制御して緊張下で１段目の第一炭素化をする。
<First carbonization treatment>
The flame-resistant fiber can be carbonized by employing a conventionally known method. For example, the temperature is gradually raised in a first carbonization furnace at 300 to 800 ° C. in a nitrogen atmosphere, and the first carbonization in the first stage is performed under tension by controlling the tension of the flameproof fiber.
＜第二炭素化処理＞
より炭素化を進め且つグラファイト化(炭素の高結晶化)を進める為に、窒素等の不活性ガス雰囲気下８００〜１６００℃で第二炭素化炉で徐々に温度を高めると共に、第一炭素化繊維の張力を制御して焼成する。
<Second carbonization treatment>
In order to promote further carbonization and graphitization (high crystallization of carbon), the temperature is gradually increased in a second carbonization furnace at 800 to 1600 ° C. in an inert gas atmosphere such as nitrogen, and the first carbonization is performed. Firing is performed by controlling the tension of the fiber.
なお、各炭素化炉において、炉の入り口付近からに急激な温度変化、例えば最高温度に急激に繊維を導入することは、表面欠陥、内部欠陥を多く発生させるため好ましくない。また、炉内の高温部で必要以上に滞留時間が長くなると、グラファイト化が進み過ぎ、脆性化した炭素繊維が得られることになるので好ましくない。 In each carbonization furnace, it is not preferable to introduce fibers rapidly from the vicinity of the furnace entrance, for example, abruptly at the maximum temperature, because many surface defects and internal defects are generated. Further, if the residence time becomes longer than necessary at a high temperature portion in the furnace, graphitization proceeds excessively, and brittle carbon fibers are obtained, which is not preferable.
上記第一炭素化処理〜第二炭素化工程は、張力をコントロールすると共に、必要に応じて、複数の炉で所定の物性となるように処理を行っても良い。 In the first carbonization treatment to the second carbonization step, the tension may be controlled and, if necessary, treatment may be performed in a plurality of furnaces so as to have predetermined physical properties.
＜原料炭素繊維＞
本例の製造方法に用いる原料は、上記第二炭素化炉から取出された後の炭素繊維や、その他いずれかの方法で製造された炭素繊維であって、炭素化炉から取出された後、何ら処理を施していない炭素繊維からなるストランドである。ストランド弾性率は２９０〜３５０ＧＰａ、好ましくは２９０〜３４５ＧＰａである。
<Raw carbon fiber>
The raw material used in the production method of this example is carbon fiber after being taken out from the second carbonization furnace, or carbon fiber produced by any other method, and after being taken out from the carbonization furnace, It is a strand made of carbon fiber that has not been subjected to any treatment. The strand elastic modulus is 290 to 350 GPa, preferably 290 to 345 GPa.
この原料炭素繊維ストランドは、炭素繊維フィラメントを束ねたものであって、そのフィラメント数は６０００〜２４０００本(６〜２４ｋ)が好ましい。 This raw material carbon fiber strand is a bundle of carbon fiber filaments, and the number of filaments is preferably 6,000 to 24,000 (6 to 24 k).
＜表面酸化処理＞
上記原料炭素繊維ストランドは、電解液中、処理電気量１５〜９０Ｃ／ｇ、好ましくは２０〜９０Ｃ／ｇで表面酸化処理を施す。処理電気量が１５Ｃ／ｇ未満の場合は、後工程のサイジング処理後の炭素繊維の表面酸素濃度比Ｏ／Ｃが小さくなる。更に、動的測定による初期濡れ性の絶対値が大きくなり、ＯＨＴ測定中に低い張力で剥離が発生するので好ましくない。処理電気量が９０Ｃ／ｇを超える場合は、表面酸素濃度比Ｏ／Ｃが大きくなり過ぎる。更に、動的測定による初期濡れ性の絶対値が小さくなり、ＯＨＴが低下するので好ましくない。
<Surface oxidation treatment>
The raw material carbon fiber strand is subjected to a surface oxidation treatment in an electrolytic solution at a processing electricity of 15 to 90 C / g, preferably 20 to 90 C / g. When the amount of electricity to be treated is less than 15 C / g, the surface oxygen concentration ratio O / C of the carbon fiber after the sizing treatment in the subsequent step becomes small. Furthermore, the absolute value of initial wettability by dynamic measurement becomes large, and peeling occurs at a low tension during OHT measurement, which is not preferable. If the amount of electricity processed exceeds 90 C / g, the surface oxygen concentration ratio O / C becomes too large. Furthermore, since the absolute value of the initial wettability by dynamic measurement becomes small and OHT falls, it is not preferable.
電解液としては、硝酸、硫酸等の無機酸、硫酸アンモニウム等の無機酸塩などの水溶液を使用できるが、安全性や取扱性の面から硫酸アンモニウム水溶液がより好ましい。電解液の温度は２５〜５０℃が好ましい。電解液の濃度は０．５〜２．０Ｎが好ましく、０．７〜１．５Ｎがより好ましい。 As the electrolytic solution, an aqueous solution of an inorganic acid such as nitric acid or sulfuric acid or an inorganic acid salt such as ammonium sulfate can be used, but an aqueous ammonium sulfate solution is more preferable in terms of safety and handling. The temperature of the electrolytic solution is preferably 25 to 50 ° C. The concentration of the electrolytic solution is preferably 0.5 to 2.0N, and more preferably 0.7 to 1.5N.
＜二段開繊処理＞
開繊処理は二段で実施する。具体的には、上記表面酸化処理後の炭素繊維ストランドを水洗する。この水洗後の炭素繊維ストランドに一段目開繊処理を施した後、乾燥し、次いで二段目開繊処理を施す。
<Two-stage spread processing>
The opening process is carried out in two stages. Specifically, the carbon fiber strand after the surface oxidation treatment is washed with water. The water-washed carbon fiber strand is subjected to the first-stage opening treatment, dried, and then subjected to the second-stage opening treatment.
本例の一段目開繊処理は、複数のローラー、好ましくは２〜５本の平ローラーに炭素繊維ストランドを接触させることにより行う。炭素繊維ストランドの張力は、１フィラメントあたり０．９〜２．０ｍＮが好ましい。 The first stage fiber opening treatment in this example is performed by bringing the carbon fiber strand into contact with a plurality of rollers, preferably 2 to 5 flat rollers. The tension of the carbon fiber strand is preferably 0.9 to 2.0 mN per filament.
この一段目開繊処理後の炭素繊維ストランドは、引き続き、１００〜１３０℃で乾燥させる。 The carbon fiber strand after the first-stage opening treatment is subsequently dried at 100 to 130 ° C.
次いで、上記乾燥後の炭素繊維ストランドに、二段目開繊処理を施す。二段目開繊処理も、複数のローラー、好ましくは２〜５本の平ローラーに炭素繊維ストランドを接触させることにより行う。 Next, a second-stage fiber opening treatment is performed on the carbon fiber strand after the drying. The second stage fiber opening treatment is also performed by bringing the carbon fiber strand into contact with a plurality of rollers, preferably 2 to 5 flat rollers.
以上の二段開繊処理における炭素繊維ストランドの張力は、１フィラメントあたり０．９〜２．０ｍＮが好ましい。二段開繊処理により、炭素繊維ストランドは、その断面が扁平な楕円の形状になり、ストランド幅が広がる。 The tension of the carbon fiber strand in the above two-stage opening treatment is preferably 0.9 to 2.0 mN per filament. By the two-stage fiber opening treatment, the carbon fiber strand has an elliptical shape with a flat cross section, and the strand width increases.
二段開繊処理を施さない場合は、後工程のサイジング処理後の炭素繊維について張力下のストランド幅広がり性が悪くなったり、動的測定による初期応力及び初期濡れ性の絶対値が大きくなったり、剥離発生時の強度が低くなったりするので好ましくない。 When the two-stage fiber opening treatment is not performed, the strand width spreadability under tension of the carbon fiber after the sizing treatment in the subsequent step is deteriorated, or the absolute value of initial stress and initial wettability by dynamic measurement is increased. This is not preferable because the strength at the time of occurrence of peeling is lowered.
＜サイジング処理＞
二段の開繊処理により充分開繊された炭素繊維ストランドは、サイジング液に通され、サイズ剤が付与される。サイジング液におけるサイズ剤の濃度は、１０〜２５質量％が好ましく、サイズ剤の付着量は、０．４〜１．７質量％が好ましい。
<Sizing process>
The carbon fiber strand that has been sufficiently opened by the two-stage opening treatment is passed through a sizing solution to give a sizing agent. The concentration of the sizing agent in the sizing liquid is preferably 10 to 25% by mass, and the adhesion amount of the sizing agent is preferably 0.4 to 1.7% by mass.
サイズ剤の付着量が０．４質量％未満のサイジング処理後の炭素繊維は、張力下でストランド幅を広げて炭素繊維を等間隔に引き揃え並べた後、加熱して樹脂を炭素繊維に含浸させてなるプリプレグを作製する際に発生毛羽が多くなるので好ましくない。 Carbon fiber after sizing treatment with a sizing amount of less than 0.4% by mass is expanded by spreading the strand width under tension and aligning the carbon fibers at equal intervals, and then heating to impregnate the carbon fibers with the resin. Since the generated fluff increases when producing the prepreg formed, it is not preferable.
サイズ剤の付着量が１．７質量％を超えるサイジング処理後の炭素繊維は、張力下のストランド幅広がり性が悪い。更に、動的測定による初期応力及び初期濡れ性の絶対値が大きく、樹脂層厚み／樹脂含浸層厚み割合が大きく、ＯＨＴが低く、剥離発生時の強度が低くなるので好ましくない。 The carbon fiber after the sizing treatment in which the adhesion amount of the sizing agent exceeds 1.7% by mass has poor strand width spreadability under tension. Further, the absolute values of initial stress and initial wettability by dynamic measurement are large, the ratio of resin layer thickness / resin impregnated layer thickness is large, OHT is low, and the strength at the time of occurrence of peeling is not preferable.
炭素繊維ストランドに付与されるサイズ剤は、特に限定されず、例えば、エポキシ樹脂、ウレタン樹脂、ポリエステル樹脂、ビニルエステル樹脂、ポリアミド樹脂、ポリエーテル樹脂、アクリル樹脂、ポリオレフィン樹脂、ポリイミド樹脂やその変性物が挙げられる。 The sizing agent applied to the carbon fiber strand is not particularly limited. For example, epoxy resin, urethane resin, polyester resin, vinyl ester resin, polyamide resin, polyether resin, acrylic resin, polyolefin resin, polyimide resin or a modified product thereof. Is mentioned.
なお、複合材料のマトリックス樹脂に応じ、適したサイズ剤を適宜選択することができる。また、このサイズ剤は二種類以上を組み合わせて使用することも可能である。サイズ剤付与処理は、通常、乳化剤等を用いて得られる水系エマルジョン中に炭素繊維ストランドを浸漬するエマルジョン法が用いられる。また、炭素繊維の取扱性や、耐擦過性、耐毛羽性、含浸性を向上させるため、分散剤、界面活性剤等の補助成分をサイズ剤に添加しても良い。 Note that a suitable sizing agent can be appropriately selected according to the matrix resin of the composite material. Moreover, this sizing agent can also be used in combination of 2 or more types. In the sizing agent application treatment, an emulsion method is generally used in which carbon fiber strands are immersed in an aqueous emulsion obtained using an emulsifier or the like. In addition, auxiliary components such as a dispersant and a surfactant may be added to the sizing agent in order to improve the handleability, scratch resistance, fluff resistance, and impregnation properties of the carbon fiber.
＜乾燥処理＞
サイジング処理後の炭素繊維ストランドは、サイジング処理時の分散媒であった水等を蒸散させるため乾燥処理が施され、複合材料製造用炭素繊維ストランドが得られる。乾燥にはエアドライヤーを用いることが好ましい。乾燥温度は特に限定されるものではないが、汎用的な水系エマルジョンの場合は通常１００〜１８０℃に設定される。また、本発明においては、乾燥工程の後、２００℃以上の熱処理工程を経ることも可能である。
<Drying process>
The carbon fiber strand after the sizing treatment is subjected to a drying treatment to evaporate water or the like that was a dispersion medium at the time of the sizing treatment, and a carbon fiber strand for producing a composite material is obtained. It is preferable to use an air dryer for drying. The drying temperature is not particularly limited, but is generally set to 100 to 180 ° C. in the case of a general-purpose aqueous emulsion. Moreover, in this invention, it is also possible to pass through the heat processing process (200 degreeC or more) after a drying process.
＜ロール巻取り処理＞
上記複合材料製造用炭素繊維ストランドは、ロール巻取り工程でロールに巻き取られ、炭素繊維ストランドロールが得られる。
<Roll winding process>
The said carbon fiber strand for composite material manufacture is wound up by a roll at a roll winding process, and a carbon fiber strand roll is obtained.
このようにして製造された炭素繊維ストランドは、サイズ剤が充分均一に含浸されているので、これを用いて複合材料を形成する際に、樹脂材料と炭素繊維とが均一に混合される。その結果、得られる複合材料は高いＯＨＴ値を示し、またＯＨＴ試験時の剥離生成が少ない。 Since the carbon fiber strands thus produced are sufficiently uniformly impregnated with the sizing agent, the resin material and the carbon fibers are uniformly mixed when a composite material is formed using the sizing agent. As a result, the resulting composite material exhibits a high OHT value and produces less exfoliation during the OHT test.
以下、実施例により本発明を更に具体的に説明する。 Hereinafter, the present invention will be described more specifically with reference to examples.
以下の実施例及び比較例に記載した条件により炭素繊維強化複合材料製造用の炭素繊維を作製した。各炭素繊維の諸物性値を、以下の方法により測定した。 Carbon fibers for producing a carbon fiber reinforced composite material were produced under the conditions described in the following examples and comparative examples. Various physical properties of each carbon fiber were measured by the following methods.
＜ストランド弾性率＞
表面酸化処理前の原料炭素繊維からなるストランドについて、ＪＩＳ Ｒ ７６０１に規定された方法により弾性率を測定した。
<Strand modulus>
About the strand which consists of raw material carbon fiber before surface oxidation treatment, the elasticity modulus was measured by the method prescribed | regulated to JISR7601.
＜表面酸素濃度比Ｏ／Ｃ＞
日本電子社製Ｘ線光電子分光器(ＥＳＣＡ ＪＰＳ−９０００ＭＸ)を用いて測定を行った。炭素繊維ストランドを１０-6Ｐａに減圧した測定室に入れ、Ｍｇを対極として電子線加速電圧１０ｋＶ、１０ｍＡの条件で発生させたＸ線を照射した。酸素原子、炭素原子より発生する光電子のスペクトルからその面積比を算出し、表面酸素濃度比Ｏ／Ｃとした。
<Surface oxygen concentration ratio O / C>
Measurement was performed using an X-ray photoelectron spectrometer (ESCA JPS-9000MX) manufactured by JEOL Ltd. The carbon fiber strand was put into a measurement chamber whose pressure was reduced to 10 −6 Pa, and irradiated with X-rays generated under conditions of an electron beam acceleration voltage of 10 kV and 10 mA using Mg as a counter electrode. The area ratio was calculated from the spectrum of photoelectrons generated from oxygen atoms and carbon atoms, and was defined as the surface oxygen concentration ratio O / C.
＜サイズ剤付着量＞
炭素繊維ストランドのサイズ剤付着量(質量％)を下記の方法で測定した。
<Amount of sizing agent attached>
The sizing agent adhesion amount (% by mass) of the carbon fiber strand was measured by the following method.
炭素繊維ストランドを、約５ｇ採取し、その質量(Ｗ1)を秤量後、１００ｍｌのアセトン中で１０分間洗浄して、脱サイズ剤処理を施した。次いで、この炭素繊維ストランドをアセトン中から取り出し、１００℃で２０分間乾燥した。その後、デシケーターに入れ室温まで冷却し、その質量(Ｗ2)を秤量した。サイズ剤付着量(質量％)は、次式
サイズ剤付着量(質量％)＝(Ｗ1−Ｗ2)／(Ｗ1)×１００
により求めた。
About 5 g of carbon fiber strands were sampled and weighed (W 1 ), washed in 100 ml of acetone for 10 minutes, and subjected to a sizing agent treatment. Next, the carbon fiber strand was taken out from acetone and dried at 100 ° C. for 20 minutes. After cooling to room temperature placed in a desiccator, and weighed and its mass (W 2). The sizing agent adhesion amount (mass%) is the following formula sizing agent adhesion quantity (mass%) = (W 1 −W 2 ) / (W 1 ) × 100
Determined by
＜張力下のストランド幅広がり性及び毛羽本数＞
この得られた炭素繊維ストランドの広がり性を測定するため、直径１５ｍｍのステンレス製棒(表面粗度１５０番手)３本を５ｃｍの間隔で軸芯を平行に並べた。炭素繊維ストランドをこの３本にジグザグ状にかけ、５ｍ／分でバックテンション９．８Ｎをかけ、通過させた。
<Strand width spread under tension and number of fuzz>
In order to measure the spreadability of the obtained carbon fiber strands, three stainless steel rods having a diameter of 15 mm (surface roughness of 150) were arranged in parallel at an interval of 5 cm. The three carbon fiber strands were zigzag-shaped and passed with a back tension of 9.8 N at 5 m / min.
１分間ストランド幅を測定し、その１分間の測定時におけるストランド幅の平均値でイールドを除して得た値を、張力下のストランド幅広がり性とした。 The strand width was measured for 1 minute, and the value obtained by dividing the yield by the average value of the strand width during the 1 minute measurement was defined as the strand width spreadability under tension.
ここで、イールドとは、炭素繊維ストランド１０００ｍあたりの重量の事であり、通常ｔｅｘで表示される。 Here, the yield is the weight per 1000 m of the carbon fiber strand, and is usually displayed in tex.
また、この測定時における毛羽の発生本数を１分間カウントし、１ｍあたりの毛羽本数として算出した。 In addition, the number of fluffs generated at the time of measurement was counted for 1 minute and calculated as the number of fluffs per meter.
＜動的測定による初期濡れ性＞
(株)レスカ社製動的濡れ性試験器を用いて測定した。図１に、動的濡れ性試験の概略説明図を示す。まず、炭素繊維ストランドを４ｃｍ採取し、これを試験片２として動的濡れ性試験器のチャック(不図示)に装着した。あらかじめ、樹脂４として東邦製エポキシ樹脂＃１３５を７０℃に加温しておき、測定用の樹脂皿(不図示)にセットした。その後、樹脂４への浸漬速度を２ｍｍ／ｓｅｃとして応力を測定し、得られたチャート６より初期応力を読み取り、初期濡れ性を算出した。
<Initial wettability by dynamic measurement>
This was measured using a dynamic wettability tester manufactured by Reska Co., Ltd. FIG. 1 is a schematic explanatory diagram of the dynamic wettability test. First, 4 cm of carbon fiber strands were sampled, and this was attached as a
更に詳述すると、チャート６は、縦軸が応力８を示し、横軸が時間１０を示す。チャート６における点Ａ〜Ｄは、
Ａ：測定開始点
Ｂ：試験片が樹脂に接触した点
Ｃ：試験片が樹脂に押しつけられた状態における最大応力発生点
Ｄ：試験片と樹脂の濡れが進行し、樹脂の液面が水平に戻った点
を示す。点Ａ〜Ｄのうち応力８が最大になる点Ｃを初期応力として測定し、ストランドイールド当たりの値を初期濡れ性とした。
More specifically, in the chart 6, the vertical axis indicates the stress 8 and the horizontal axis indicates the
A: Measurement start point B: Point where the test piece contacts the resin C: Maximum stress generation point when the test piece is pressed against the resin D: Wetting of the test piece and the resin proceeds, and the liquid level of the resin becomes horizontal Indicates the point returned. Among points A to D, point C at which stress 8 was maximum was measured as initial stress, and the value per strand yield was defined as initial wettability.
＜層間樹脂厚み／層内厚み割合、ＯＨＴ、剥離発生時の強度＞
エポキシ樹脂組成物(東邦製エポキシ樹脂＃１３５)を使用し測定を実施した。この樹脂組成物を、フィルムコーターにより離型紙の上に塗布し、樹脂フィルムとした。この樹脂フィルム上に炭素繊維を等間隔に引き揃え並べた後、加熱して樹脂を炭素繊維に含浸させ、目付１９０ｇ／ｍ2、樹脂含有率(ＲＣ：Ｒｅｓｉｎ Ｃｏｎｔｅｎｔ)３５質量％のプリプレグを作製した。引き続き、プリプレグを[＋４５／０／−４５／９０]2Sの構成で、未含浸の残留樹脂フィルムと交互に積層し、オートクレーブ中で硬化して炭素繊維強化複合材料(ＣＦＲＰ)を得た。
<Interlayer resin thickness / in-layer thickness ratio, OHT, strength at the time of peeling>
Measurement was performed using an epoxy resin composition (Epoxy resin # 135 manufactured by Toho). This resin composition was applied onto release paper with a film coater to obtain a resin film. After aligning carbon fibers on this resin film at equal intervals and heating, carbon fiber is impregnated by heating to produce a prepreg having a basis weight of 190 g / m 2 and a resin content (RC: Resin Content) of 35% by mass. did. Subsequently, the prepreg was alternately laminated with an unimpregnated residual resin film in the configuration of [+ 45/0 / −45 / 90] 2S and cured in an autoclave to obtain a carbon fiber reinforced composite material (CFRP).
ＳＡＣＭＡ ＳＲＭ ５Ｒに従い、このＣＦＲＰから、図２に示すように、０度方向(Ｙ方向)が３０４．８ｍｍ、９０度方向(Ｘ方向)が３８．１０ｍｍの長方形に切りだし、直径６．３７ｍｍの穴１２をあけ、樹脂層厚み／樹脂含浸層厚み割合、ＯＨＴ、剥離発生時の強度の測定用複合材料試験片１４とした。
According to SACMA SRM 5R, as shown in FIG. 2, from this CFRP, a 0 ° direction (Y direction) is cut into a rectangle of 304.8 mm and a 90 ° direction (X direction) is 38.10 mm, and the diameter is 6.37 mm. The
この複合材料試験片１４の断面(厚み方向が拡大されている)をＬａｓｅｒ社製Ｓｃａｎｎｉｎｇ Ｌａｓｅｒ Ｍｉｃｒｏｓｃｏｐｅにて２０倍にて観察し、複合材料の樹脂層厚み(ａ)と、樹脂含浸層厚み(ｂ)とを読み取り、樹脂層の厚み(ａ)と樹脂含浸層の厚み(ｂ)との比[厚み割合(ａ／ｂ)]を算出して(ａ／ｂ)×１００の％表示とした。ここで、樹脂含浸層厚みは、炭素繊維と、炭素繊維間に含浸された樹脂とからなる樹脂含浸層の厚みと定義される。樹脂層の厚みは、前記炭素繊維と樹脂とからなる樹脂含浸層の間にあって、炭素繊維が含まれない樹脂のみからなる層の厚みと定義される。
The cross section (thickness direction is enlarged) of this
さらに、この複合材料試験片を用いてＳＡＣＭＡ ＳＲＭ ５Ｒに従ってＯＨＴの測定を行い、ＯＨＴの値(ＭＰａ)を求めた。 Furthermore, OHT was measured according to SACMA SRM 5R using this composite material test piece, and the value of OHT (MPa) was obtained.
また、複合材料試験片のデラミネーション(試験片の応力下剥離)の評価は、ＯＨＴ測定時に試験片端部の状況を目視により確認し、剥離が発生した時の値を剥離発生時の強度(ＭＰａ)とした。 In addition, evaluation of delamination (peeling under stress of the test piece) of the composite material test piece is performed by visually checking the state of the end of the test piece at the time of OHT measurement, and the value at the time of peeling is determined by the strength (MPa). ).
実施例１
アクリロニトリル９５質量％／アクリル酸メチル４質量％／イタコン酸１質量％よりなる共重合体紡糸原液を湿式紡糸し、水洗・乾燥・延伸・オイリングして繊維直径９．０μｍのアクリル系前駆体繊維を得た。この前駆体繊維を、熱風循環式耐炎化炉の加熱空気中２００〜２６０℃の温度域を通過させると共に０．９５〜１．１０の延伸比で延伸させて耐炎化処理し、耐炎化繊維を得た。
Example 1
A copolymer spinning stock solution of 95% by mass of acrylonitrile / 4% by mass of methyl acrylate / 1% by mass of itaconic acid is wet-spun, washed with water, dried, drawn and oiled to produce an acrylic precursor fiber having a fiber diameter of 9.0 μm. Obtained. This precursor fiber was passed through a temperature range of 200 to 260 ° C. in the heated air of a hot-air circulation type flameproofing furnace and stretched at a stretch ratio of 0.95 to 1.10. Obtained.
この耐炎化繊維を、第一炭素化炉の不活性ガス雰囲気中３００〜８００℃の温度域を通過させて第一炭素化処理を施した。 This flame-resistant fiber was subjected to a first carbonization treatment by passing through a temperature range of 300 to 800 ° C. in an inert gas atmosphere of the first carbonization furnace.
この第一炭素化処理繊維を、第二炭素化炉の不活性ガス雰囲気中８００〜１５５０℃の温度域を通過させて第二炭素化処理を施し、ストランド弾性率が３１４ＧＰａ、フィラメント数が２４０００本(２４ｋ)、イールドが８１０ｔｅｘの原料炭素繊維を得た。 The first carbonized fiber is subjected to a second carbonization treatment by passing through a temperature range of 800 to 1550 ° C. in an inert gas atmosphere of the second carbonization furnace. The strand elastic modulus is 314 GPa and the number of filaments is 24,000. (24k) A raw carbon fiber having a yield of 810 tex was obtained.
次いで、この原料炭素繊維を、３５℃、濃度１Ｎの硫酸アンモニウム水溶液を電解液(処理剤)として用い、処理電気量２５Ｃ／ｇで、表面酸化処理を施した。次いで、水洗処理を施した。 Next, this raw material carbon fiber was subjected to surface oxidation treatment at an electric charge of 25 C / g using an aqueous ammonium sulfate solution at 35 ° C. and a concentration of 1 N as an electrolytic solution (treatment agent). Subsequently, the water washing process was performed.
さらに、この水洗処理後の炭素繊維に開繊処理を施した。開繊処理は二段で実施した。まず、一段目開繊処理は２本の平ローラーを用いて行った。引き続き、一段目開繊処理後の炭素繊維を１００℃で乾燥処理した。この乾燥処理後の炭素繊維に二段目開繊処理を施した。二段目開繊処理は、３本の平ローラーを用いて行った。一段目、二段目共に開繊処理時の張力は１フィラメントあたり１．０ｍＮで行った。また、開繊処理後のストランド幅は６．０ｍｍであった。このストランド幅６．０ｍｍは、後述する比較例１の開繊しなかったストランド幅２．８ｍｍの２倍以上に相当する。 Further, the carbon fiber after the water washing treatment was subjected to a fiber opening treatment. The opening process was carried out in two stages. First, the first-stage fiber opening treatment was performed using two flat rollers. Subsequently, the carbon fiber after the first-stage opening treatment was dried at 100 ° C. The carbon fiber after this drying treatment was subjected to a second stage opening treatment. The second stage fiber opening treatment was performed using three flat rollers. In both the first and second stages, the tension during the fiber opening treatment was 1.0 mN per filament. Further, the strand width after the fiber opening treatment was 6.0 mm. The strand width of 6.0 mm corresponds to twice or more the strand width of 2.8 mm that was not opened in Comparative Example 1 described later.
二段開繊処理後の炭素繊維を、濃度１５質量％の水系エポキシ樹脂エマルジョンからなるサイジング液に通し、サイズ剤を付与した。サイジング剤付与処理後の炭素繊維を、１４０℃で４分間乾燥処理し、ボビンに巻き取って複合材料製造用炭素繊維を得た。 The carbon fiber after the two-stage opening treatment was passed through a sizing solution composed of a water-based epoxy resin emulsion having a concentration of 15% by mass to give a sizing agent. The carbon fiber after the sizing agent application treatment was dried at 140 ° C. for 4 minutes and wound on a bobbin to obtain a carbon fiber for producing a composite material.
得られた複合材料製造用炭素繊維は、表面酸素濃度比Ｏ／Ｃが１３％、サイズ剤付着量が０．７質量％、張力下の広がりストランド幅が８．５ｍｍ、イールドが８１０ｔｅｘ、張力下のストランド幅広がり性が９５ｔｅｘ／ｍｍ、張力下のストランド幅広がり性測定時の発生毛羽が５ヶ／ｍ、動的測定による初期応力が−０．５ｍＮ、動的測定による初期濡れ性が−５．９×１０-4ｍＮ／ｔｅｘであり、その複合材料は厚み割合(ａ／ｂ)が１１％、ＯＨＴが４８０ＭＰａ、剥離発生時の強度が３１０ＭＰａと良好であった。 The resulting carbon fiber for producing a composite material has a surface oxygen concentration ratio O / C of 13%, a sizing agent adhesion amount of 0.7% by mass, a spread width under tension of 8.5 mm, a yield of 810 tex, and under tension. Strand width spread of 95 tex / mm, strand width spread measurement under tension of 5 fl / m, initial stress by dynamic measurement is -0.5 mN, initial wettability by dynamic measurement is -5 .9 × a 10 -4 mN / tex, their composite ratio thickness (a / b) is 11%, OHT is 480 MPa, the strength at the time of peeling occurred was good and 310 MPa.
実施例２〜７及び比較例１〜８
表１に示す弾性率の原料炭素繊維を表１に示す条件で処理した以外は、実施例１と同様に表面酸化処理以降の処理を行い、表１に示す炭素繊維を得た。
Examples 2-7 and Comparative Examples 1-8
Except having processed the raw material carbon fiber of the elasticity modulus shown in Table 1 on the conditions shown in Table 1, the process after surface oxidation treatment was performed similarly to Example 1, and the carbon fiber shown in Table 1 was obtained.
具体的には、実施例２においては、サイズ剤付着量を１．３質量％とした以外は、実施例１と同様に表面酸化処理以降の処理を行った。その結果、得られた炭素繊維は表１に示すように、実施例１と同様に複合材料用の炭素繊維として良好であった。 Specifically, in Example 2, the treatment after the surface oxidation treatment was performed in the same manner as in Example 1 except that the amount of sizing agent attached was 1.3% by mass. As a result, as shown in Table 1, the obtained carbon fiber was good as a carbon fiber for a composite material as in Example 1.
実施例３においては、表面酸化処理時の電気量を３５Ｃ／ｇとした以外は、実施例１と同様に表面酸化処理以降の処理を行った。その結果、得られた炭素繊維は表１に示すように、実施例１と同様に複合材料用の炭素繊維として良好であった。 In Example 3, treatment after the surface oxidation treatment was performed in the same manner as in Example 1 except that the amount of electricity during the surface oxidation treatment was 35 C / g. As a result, as shown in Table 1, the obtained carbon fiber was good as a carbon fiber for a composite material as in Example 1.
実施例４においては、ストランド弾性率が２９４ＧＰａ、フィラメント数が２４０００本(２４ｋ)、イールドが８３０ｔｅｘの原料炭素繊維を用いた以外は、実施例１と同様に表面酸化処理以降の処理を行った。その結果、得られた炭素繊維は表１に示すように、実施例１と同様に複合材料用の炭素繊維として良好であった。 In Example 4, the treatment after the surface oxidation treatment was performed in the same manner as in Example 1 except that raw material carbon fiber having a strand elastic modulus of 294 GPa, a filament number of 24,000 (24 k), and a yield of 830 tex was used. As a result, as shown in Table 1, the obtained carbon fiber was good as a carbon fiber for a composite material as in Example 1.
実施例５においては、ストランド弾性率が３４３ＧＰａ、フィラメント数が１２０００本(１２ｋ)、イールドが４１０ｔｅｘの原料炭素繊維を用いた以外は、実施例１と同様に表面酸化処理以降の処理を行った。その結果、得られた炭素繊維は表１に示すように、実施例１と同様に複合材料用の炭素繊維として良好であった。 In Example 5, the treatment after the surface oxidation treatment was performed in the same manner as in Example 1 except that raw material carbon fiber having a strand elastic modulus of 343 GPa, a filament number of 12,000 (12 k), and a yield of 410 tex was used. As a result, as shown in Table 1, the obtained carbon fiber was good as a carbon fiber for a composite material as in Example 1.
比較例１においては、二段開繊処理を施さなかった以外は、実施例１と同様に表面酸化処理以降の処理を行った。その際のストランド幅は２．８ｍｍであった。その結果、得られた炭素繊維は表１に示すように、動的測定による初期応力及び初期濡れ性の絶対値が大きく、剥離発生時の強度が低いものであり、複合材料用の炭素繊維として不十分なものであった。 In Comparative Example 1, the treatment after the surface oxidation treatment was performed in the same manner as in Example 1 except that the two-stage fiber opening treatment was not performed. The strand width at that time was 2.8 mm. As a result, the obtained carbon fiber has a large absolute value of initial stress and initial wettability by dynamic measurement as shown in Table 1, and has a low strength at the time of delamination. As a carbon fiber for a composite material, It was insufficient.
比較例２においては、サイズ剤付着量を０．３質量％とした以外は、実施例１と同様に表面酸化処理以降の処理を行った。その結果、得られた炭素繊維は表１に示すように、張力下のストランド幅広がり性測定時の発生毛羽が多いものであり、複合材料用の炭素繊維として不十分なものであった。 In Comparative Example 2, treatments after the surface oxidation treatment were performed in the same manner as in Example 1 except that the amount of sizing agent attached was 0.3% by mass. As a result, as shown in Table 1, the obtained carbon fiber had a lot of fluff generated when measuring the strand width spreadability under tension, and was insufficient as a carbon fiber for a composite material.
比較例３においては、サイズ剤付着量を１．８質量％とした以外は、実施例１と同様に表面酸化処理以降の処理を行った。その結果、得られた炭素繊維は表１に示すように、張力下のストランド幅広がり性が悪く、動的測定による初期応力及び初期濡れ性の絶対値が大きく、樹脂層厚み／樹脂含浸層厚み割合が大きく、ＯＨＴが低く、剥離発生時の強度が低いものであり、複合材料用の炭素繊維として不十分なものであった。 In Comparative Example 3, treatments after the surface oxidation treatment were performed in the same manner as in Example 1 except that the amount of sizing agent attached was 1.8% by mass. As a result, as shown in Table 1, the obtained carbon fiber had poor strand width spreadability under tension, and had a large absolute value of initial stress and initial wettability by dynamic measurement, and the resin layer thickness / resin impregnated layer thickness. The ratio was large, the OHT was low, and the strength when peeling occurred was low, which was insufficient as a carbon fiber for composite materials.
比較例４においては、表面酸化処理時の電気量を１０Ｃ／ｇとした以外は、実施例１と同様に表面酸化処理以降の処理を行った。その結果、得られた炭素繊維は表１に示すように、表面酸素濃度比Ｏ／Ｃが小さく、動的測定による初期応力及び初期濡れ性の絶対値が大きく、剥離発生時の強度が低いものであり、複合材料用の炭素繊維として不十分なものであった。 In Comparative Example 4, the treatment after the surface oxidation treatment was performed in the same manner as in Example 1 except that the amount of electricity during the surface oxidation treatment was 10 C / g. As a result, as shown in Table 1, the obtained carbon fiber has a small surface oxygen concentration ratio O / C, a large absolute value of initial stress and initial wettability by dynamic measurement, and a low strength when peeling occurs. It was insufficient as a carbon fiber for composite materials.
比較例５においては、表面酸化処理時の電気量を１００Ｃ／ｇとした以外は、実施例１と同様に表面酸化処理以降の処理を行った。その結果、得られた炭素繊維は表１に示すように、表面酸素濃度比Ｏ／Ｃが大きく、動的測定による初期応力及び初期濡れ性の絶対値が小さく、ＯＨＴが低いものであり、複合材料用の炭素繊維として不十分なものであった。 In Comparative Example 5, the treatment after the surface oxidation treatment was performed in the same manner as in Example 1 except that the amount of electricity at the time of the surface oxidation treatment was 100 C / g. As a result, as shown in Table 1, the obtained carbon fiber has a large surface oxygen concentration ratio O / C, a small absolute value of initial stress and initial wettability by dynamic measurement, and a low OHT. It was insufficient as a carbon fiber for the material.
比較例６においては、二段開繊処理を施さなかった以外は、実施例２と同様に表面酸化処理以降の処理を行った。その結果、得られた炭素繊維は表１に示すように、張力下のストランド幅広がり性が悪く、動的測定による初期応力及び初期濡れ性の絶対値が大きく、剥離発生時の強度が低いものであり、複合材料用の炭素繊維として不十分なものであった。 In Comparative Example 6, the treatment after the surface oxidation treatment was performed in the same manner as in Example 2 except that the two-stage opening treatment was not performed. As a result, as shown in Table 1, the obtained carbon fibers have poor strand width spreadability under tension, large absolute values of initial stress and initial wettability by dynamic measurement, and low strength when peeling occurs. It was insufficient as a carbon fiber for composite materials.
比較例７においては、二段開繊処理を施さなかった以外は、実施例４と同様に表面酸化処理以降の処理を行った。その結果、得られた炭素繊維は表１に示すように、張力下のストランド幅広がり性が悪く、動的測定による初期応力及び初期濡れ性の絶対値が大きく、剥離発生時の強度が低いものであり、複合材料用の炭素繊維として不十分なものであった。 In Comparative Example 7, treatments after the surface oxidation treatment were performed in the same manner as in Example 4 except that the two-stage opening treatment was not performed. As a result, as shown in Table 1, the obtained carbon fibers have poor strand width spreadability under tension, large absolute values of initial stress and initial wettability by dynamic measurement, and low strength when peeling occurs. It was insufficient as a carbon fiber for composite materials.
比較例８においては、二段開繊処理を施さなかった以外は、実施例５と同様に表面酸化処理以降の処理を行った。その結果、得られた炭素繊維は表１に示すように、張力下のストランド幅広がり性が悪く、動的測定による初期応力及び初期濡れ性の絶対値が大きく、剥離発生時の強度が低いものであり、複合材料用の炭素繊維として不十分なものであった。 In Comparative Example 8, the treatment after the surface oxidation treatment was performed in the same manner as in Example 5 except that the two-stage opening treatment was not performed. As a result, as shown in Table 1, the obtained carbon fibers have poor strand width spreadability under tension, large absolute values of initial stress and initial wettability by dynamic measurement, and low strength when peeling occurs. It was insufficient as a carbon fiber for composite materials.
２ 炭素繊維ストランド試験片
４ 樹脂
６ チャート
８ 応力
１０ 時間
Ａ 測定開始点
Ｂ 試験片が樹脂に接触した点
Ｃ 試験片が樹脂に押しつけられた状態における最大応力発生点
Ｄ 試験片と樹脂の濡れが進行し、樹脂の液面が水平に戻った点
１２ 樹脂層厚み／樹脂含浸層厚み割合、ＯＨＴ、剥離発生時の強度の測定用複合材料試験片にあけられた穴
１４ 樹脂層厚み／樹脂含浸層厚み割合、ＯＨＴ、剥離発生時の強度の測定用複合材料試験片
Ｙ 樹脂層厚み／樹脂含浸層厚み割合、ＯＨＴ、剥離発生時の強度の測定用複合材料試験片における０度方向
Ｘ 樹脂層厚み／樹脂含浸層厚み割合、ＯＨＴ、剥離発生時の強度の測定用複合材料試験片における９０度方向
ａ 樹脂層厚み／樹脂含浸層厚み割合、ＯＨＴ、剥離発生時の強度の測定用複合材料試験片における樹脂層厚み
ｂ 樹脂層厚み／樹脂含浸層厚み割合、ＯＨＴ、剥離発生時の強度の測定用複合材料試験片における樹脂含浸層厚み
2 Carbon fiber strand test piece 4 Resin 6 Chart 8
Claims (3)
−１．３×１０-4 ≧ Ａ ≧ −６．５×１０-4
の範囲である炭素繊維。 The strand elastic modulus is 290 to 350 GPa, the surface oxygen concentration ratio O / C is 10 to 25%, the sizing agent adhesion amount is 0.4 to 1.7% by mass, and the strand width spreading property under tension is 135 tex / mm or less. The initial wettability A (mN / tex) by dynamic measurement is −1.3 × 10 −4 ≧ A ≧ −6.5 × 10 −4.
Carbon fiber that is in the range of.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2008283894A JP2010111957A (en) | 2008-11-05 | 2008-11-05 | Carbon fiber, composite material, and method for producing carbon fiber |
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| JP2008283894A JP2010111957A (en) | 2008-11-05 | 2008-11-05 | Carbon fiber, composite material, and method for producing carbon fiber |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2014115762A1 (en) | 2013-01-25 | 2014-07-31 | 東レ株式会社 | Sizing-agent-coated carbon fibre bundle, carbon-fibre-bundle production method, and prepreg |
| JP2016069759A (en) * | 2014-09-30 | 2016-05-09 | 帝人株式会社 | Fiber bundle widening method |
| JP6286112B1 (en) * | 2016-08-25 | 2018-02-28 | 倉敷紡績株式会社 | Method for producing carbon fiber spread sheet |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08113876A (en) * | 1994-10-19 | 1996-05-07 | Toray Ind Inc | Carbon fiber and its production |
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Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08113876A (en) * | 1994-10-19 | 1996-05-07 | Toray Ind Inc | Carbon fiber and its production |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2014115762A1 (en) | 2013-01-25 | 2014-07-31 | 東レ株式会社 | Sizing-agent-coated carbon fibre bundle, carbon-fibre-bundle production method, and prepreg |
| EP2949792A4 (en) * | 2013-01-25 | 2016-01-27 | Toray Industries | Sizing-agent-coated carbon fibre bundle, carbon-fibre-bundle production method, and prepreg |
| US9435057B2 (en) | 2013-01-25 | 2016-09-06 | Toray Industries, Inc. | Sizing agent-coated carbon fiber bundle, carbon fiber bundle production method, and prepreg |
| EP3800285A1 (en) | 2013-01-25 | 2021-04-07 | Toray Industries, Inc. | Sizing-agent-coated carbon fibre bundle, carbon-fibre-bundle production method, and prepreg |
| JP2016069759A (en) * | 2014-09-30 | 2016-05-09 | 帝人株式会社 | Fiber bundle widening method |
| JP6286112B1 (en) * | 2016-08-25 | 2018-02-28 | 倉敷紡績株式会社 | Method for producing carbon fiber spread sheet |
| WO2018038033A1 (en) * | 2016-08-25 | 2018-03-01 | 倉敷紡績株式会社 | Method for producing fibrillated carbon fiber sheet |
| CN108368646A (en) * | 2016-08-25 | 2018-08-03 | 仓敷纺绩株式会社 | The manufacturing method of carbon fiber fibrillation sheet material |
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