JP2019031749A - Carbon short fiber wet type nonwoven fabric and carbon short fiber-reinforced resin composition - Google Patents
Carbon short fiber wet type nonwoven fabric and carbon short fiber-reinforced resin composition Download PDFInfo
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Landscapes
- Reinforced Plastic Materials (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Nonwoven Fabrics (AREA)
- Paper (AREA)
Abstract
Description
本発明は、炭素短繊維湿式不織布に関する。 The present invention relates to a short carbon fiber wet nonwoven fabric.
炭素繊維は鉄よりも軽量であり、強度が強いという優れた力学特性を有している。そのため、炭素繊維複合材料は航空機、自動車、テニスラケット、釣竿、風力発電の羽根などの幅広い分野で使用されており、今後も用途が拡大すると予想される。 Carbon fiber is lighter than iron and has excellent mechanical properties such as high strength. For this reason, carbon fiber composite materials are used in a wide range of fields such as aircraft, automobiles, tennis rackets, fishing rods, wind power blades, and the use is expected to expand in the future.
炭素繊維としては、現在主に、ポリアクリロニトリルを炭素化、黒鉛化することで得られるＰＡＮ系炭素繊維と、タールピッチ液化石炭を溶融紡糸してから炭素化、黒鉛化することで得られるピッチ系炭素繊維とが使用されている。こうして生産された炭素繊維は、織物として加工するか、あるいは一方向に並べた後に、未硬化樹脂を含浸させた炭素繊維プリプレグと呼ばれる材料を、目標とする成形物の型に合うように裁断した後に樹脂を硬化することで得られる、炭素繊維強化樹脂（以下「ＣＦＲＰ」と略記する）として使用されることが多い。あるいは、ＣＦＲＰ廃材をリサイクルして得られた炭素繊維を使用する場合は、炭素繊維がリサイクル過程において短繊維化して炭素短繊維となることから、織物として加工することはできないため、不織布として加工されることが一般的である。 Currently, carbon fibers are mainly PAN-based carbon fibers obtained by carbonizing and graphitizing polyacrylonitrile, and pitch-based materials obtained by carbonizing and graphitizing tar pitch liquefied coal. Carbon fiber is used. The carbon fiber thus produced is processed as a woven fabric or arranged in one direction, and then a material called a carbon fiber prepreg impregnated with an uncured resin is cut so as to fit the target mold. It is often used as a carbon fiber reinforced resin (hereinafter abbreviated as “CFRP”) obtained by later curing the resin. Alternatively, when using carbon fiber obtained by recycling CFRP waste material, it is processed as a non-woven fabric because it cannot be processed as a woven fabric because the carbon fiber is shortened into a carbon short fiber in the recycling process. In general.
炭素短繊維をシート化して炭素短繊維不織布とする方法としては、炭素短繊維と水膨潤フィブリル化繊維とを水中に分散させ、抄紙用スラリーを作製し、繊維を交絡させて、炭素短繊維湿式不織布を製造する方法が開示されている。水膨潤フィブリル化繊維としては、フィブリル化パラ型芳香族ポリアミド繊維や、フィブリル化アクリル繊維が挙げられている（特許文献１参照）。しかしながら、この方法は、炭素短繊維湿式不織布をＣＦＲＰに加工する際に断裁、圧縮などの工程において、炭素短繊維湿式不織布内への樹脂の浸透性や、炭素短繊維不織布内に樹脂を均一に浸透させるという点については考慮されておらず、ＣＦＲＰ加工する際にトラブルが発生する場合がある。樹脂が浸透しづらい炭素短繊維不織布を使用した場合、炭素短繊維に樹脂を浸透させるのに時間がかかることや、樹脂の浸透量に表裏差が発生することがある。また、樹脂を均一に浸透させづらい炭素短繊維不織布を使用した場合、炭素短繊維不織布内に樹脂が多く存在する箇所とあまり存在しない箇所が発生し、圧縮・熱加工した際に品質に差が出る場合がある。 As a method of making a carbon short fiber nonwoven fabric by forming a sheet of carbon short fibers, the carbon short fibers and the water-swelled fibrillated fibers are dispersed in water, a papermaking slurry is prepared, the fibers are entangled, and the carbon short fibers are wet. A method of manufacturing a nonwoven fabric is disclosed. Examples of water-swelled fibrillated fibers include fibrillated para-type aromatic polyamide fibers and fibrillated acrylic fibers (see Patent Document 1). However, in this method, when the carbon short fiber wet nonwoven fabric is processed into CFRP, the resin permeation into the carbon short fiber wet nonwoven fabric and the resin uniformly in the carbon short fiber nonwoven fabric in the process such as cutting and compression. The point of penetration is not taken into consideration, and trouble may occur when CFRP processing is performed. When a carbon short fiber nonwoven fabric in which the resin is difficult to permeate is used, it may take time to infiltrate the resin into the carbon short fiber, and a difference in the amount of resin permeation may occur. In addition, when using carbon short fiber nonwoven fabrics that are difficult to permeate the resin uniformly, there are places where a lot of resin is present in the carbon short fiber nonwoven fabrics and places where there is not so much, and there is a difference in quality when compressed and heat processed. May come out.
また、炭素短繊維湿式不織布を製造する別方法としては、炭素短繊維７５質量％〜９７質量％、セルロース２５質量％〜３質量％からなる炭素短繊維湿式不織布を製造する方法において、含窒素有機溶媒を含有する水性分散助剤を炭素短繊維に対して１０質量％以下と炭素短繊維を所定量の水に添加して撹拌し、さらに水でスラリー固形分濃度を０．０５質量％以下に希釈して回流させる工程を経た後、湿式抄紙する方法が示されている（特許文献２参照）。しかしながら、特許文献２の炭素短繊維湿式不織布は、ガス透過性や導電性を有する不織布であり、ＣＦＲＰに使用される不織布ではないため、炭素短繊維湿式不織布をＣＦＲＰに加工する際に断裁、圧縮などの工程において樹脂を浸透しやすくする点、あるいは樹脂を均一に浸透させるという点については考慮されておらず、ＣＦＲＰとして加工した場合に問題が発生することが考えられる。 Further, as another method for producing a short carbon fiber wet nonwoven fabric, a method for producing a short carbon fiber wet nonwoven fabric comprising 75% by mass to 97% by mass of short carbon fibers and 25% by mass to 3% by mass of cellulose is used. An aqueous dispersion aid containing a solvent is added to 10% by mass or less of the short carbon fibers and the short carbon fibers are added to a predetermined amount of water and stirred, and the slurry solid content concentration is further reduced to 0.05% by mass or less with water. A method of wet papermaking after a process of diluting and circulating (see Patent Document 2) is shown. However, the short carbon fiber wet nonwoven fabric of Patent Document 2 is a nonwoven fabric having gas permeability and conductivity, and is not a nonwoven fabric used for CFRP. Therefore, when the carbon short fiber wet nonwoven fabric is processed into CFRP, it is cut and compressed. The point of making the resin easy to permeate or the point of uniformly permeating the resin is not taken into consideration, and problems may occur when processed as CFRP.
本発明の課題は、ＣＦＲＰに加工する際に、樹脂が短時間で、且つ均一に浸透する炭素短繊維湿式不織布を提供するものである。 An object of the present invention is to provide a short carbon fiber wet nonwoven fabric in which a resin penetrates uniformly in a short time when processed into CFRP.
本発明者らは、この課題を解決するため研究を行った結果、下記手段を見出した。 As a result of researches to solve this problem, the present inventors have found the following means.
（１）炭素短繊維の含有量が１０質量％〜９８質量％であり、不織布の密度が０．１２ｇ／ｃｍ３以上であり、１０本以上の炭素短繊維で構成される結束を５個／ｃｍ２以上有し、該結束を構成する炭素短繊維の平均繊維本数が５００本／結束以下であることを特徴とする炭素短繊維湿式不織布。
（２）炭素短繊維の平均繊維長が１ｍｍ以上である上記（１）記載の炭素短繊維湿式不織布。
（３）上記（１）又は（２）記載の炭素短繊維湿式不織布と該不織布と複合化された樹脂とからなる炭素短繊維強化樹脂組成物。
(1) The content of carbon short fibers is 10% by mass to 98% by mass, the density of the nonwoven fabric is 0.12 g / cm 3 or more, and the number of bundles composed of 10 or more carbon short fibers is 5 / The short carbon fiber wet nonwoven fabric characterized by having an average number of short carbon fibers of 500 cm 2 or less and having a cm 2 or more and constituting the bundling.
(2) The short carbon fiber wet nonwoven fabric according to the above (1), wherein the short carbon fibers have an average fiber length of 1 mm or more.
(3) A carbon short fiber reinforced resin composition comprising the carbon short fiber wet nonwoven fabric according to (1) or (2) and a resin combined with the nonwoven fabric.
本発明によれば、ＣＦＲＰに加工する際に樹脂が短時間で、且つ均一に浸透する炭素短繊維湿式不織布を得ることができる。 ADVANTAGE OF THE INVENTION According to this invention, when processing into CFRP, the carbon short fiber wet nonwoven fabric which resin penetrates uniformly in a short time can be obtained.
炭素短繊維を含む不織布においては、ＣＦＲＰに加工する際に樹脂を均一に浸透させることが困難である場合がある。原因としては、炭素短繊維が高強度であり、柔軟性に乏しいため、不織布に加工した際に複雑な立体構造を形成することから、低密度となることが挙げられる。つまり、不織布内の空隙が多くなることから、高粘度の樹脂を塗工した際に塗工面にのみ樹脂が浸透し、反対面である不織布の非塗工面まで樹脂が浸透しない場合がある。樹脂濃度に表裏差がある状態で熱プレス加工を行うと、完成したＣＦＲＰにおいても樹脂の濃度勾配が発生する場合があり、品質にムラが出る場合がある。樹脂を有機溶媒に希釈して塗工した後に有機溶媒を蒸発させることで、均一に樹脂を浸透させる手法もあるが、蒸発させる工程が増える上、有機溶媒の処理にコストがかかることから、できる限り避けるべきである。これらのことから、樹脂が浸透しやすい炭素短繊維湿式不織布はＣＦＲＰの安定した品質を低コストで得るためには必要である。 In a nonwoven fabric containing short carbon fibers, it may be difficult to uniformly infiltrate the resin when processed into CFRP. The cause is that the short carbon fiber has high strength and lacks flexibility, and forms a complicated three-dimensional structure when processed into a nonwoven fabric, resulting in low density. That is, since the voids in the nonwoven fabric increase, the resin may penetrate only the coated surface when a highly viscous resin is applied, and the resin may not penetrate the non-coated surface of the nonwoven fabric that is the opposite surface. If hot pressing is performed in a state where there is a difference between the front and back of the resin concentration, a resin concentration gradient may occur even in the completed CFRP, and quality may be uneven. There is also a method of uniformly infiltrating the resin by evaporating the organic solvent after coating after diluting the resin in the organic solvent, but it can be done because the process of evaporating increases the cost of the organic solvent treatment Should be avoided as long as possible. From these facts, a short carbon fiber wet nonwoven fabric in which resin easily penetrates is necessary to obtain a stable quality of CFRP at a low cost.
図１〜図３は、炭素短繊維湿式不織布の電子顕微鏡写真である。炭素短繊維は非常に高強度であり、柔軟性が乏しい。そのため、結束が少ない、又は結束が存在しない炭素短繊維を抄紙して製造された炭素短繊維湿式不織布は、図１に示したように、非常に低密度となる傾向となり、樹脂を均一に浸透させることが難しくなる場合がある。このため、抄紙の際に炭素短繊維を分散する条件を調節することで、図２に示したように、結束を構成する炭素短繊維の平均繊維本数が５００本／結束以下である炭素短繊維湿式不織布を得ることができる。結束は、炭素短繊維が密に詰まった状態であるため、結束が存在する炭素短繊維湿式不織布は比較的高密度となる傾向にある。このことから、樹脂を均一に浸透させることが容易となる。ただし、図３に示したように、ほとんど繊維が分散しておらず、結束を構成する炭素短繊維の平均繊維本数が５００本／結束超である炭素短繊維湿式不織布では、結束内部まで樹脂が浸透せず、結束内部の強度が非常に弱くなることから、ＣＦＲＰ加工後の強度にムラが存在し、欠点となる場合がある。図２の符号１は、炭素短繊維結束（結束を構成する炭素短繊維の繊維本数が５００本／結束以下）であり、図３の符号２は、炭素短繊維結束（結束を構成する炭素短繊維の繊維本数が５００本／結束超）である。 1 to 3 are electron micrographs of a short carbon fiber wet nonwoven fabric. Carbon short fibers are very high strength and poor in flexibility. Therefore, the short carbon fiber wet nonwoven fabric produced by papermaking short carbon fibers with little or no bundling tends to be very low density as shown in FIG. It may be difficult to let Therefore, by adjusting the conditions for dispersing the short carbon fibers during papermaking, as shown in FIG. 2, the short carbon fibers having an average number of short carbon fibers constituting the bundling of 500 or less are obtained. A wet nonwoven fabric can be obtained. Since the short carbon fibers are tightly packed, the short carbon fiber wet nonwoven fabric with the bundling tends to have a relatively high density. For this reason, it becomes easy to uniformly infiltrate the resin. However, as shown in FIG. 3, in the short carbon fiber wet nonwoven fabric in which the fibers are hardly dispersed and the average number of short carbon fibers constituting the bundling is 500 / bundled, the resin is contained up to the inside of the bundling. Since it does not penetrate and the strength inside the bundle becomes very weak, the strength after CFRP processing is uneven, which may be a drawback. Reference numeral 1 in FIG. 2 is a short carbon fiber bundle (the number of short carbon fibers constituting the bundle is 500 / bundled or less), and reference numeral 2 in FIG. 3 is a short carbon fiber bundle (the short carbon fiber constituting the bundle). The number of fibers is 500 / bundled).
炭素短繊維としては、ＰＡＮ系、ピッチ系など、どのような製法で製造された炭素短繊維でも使用することができる。また、新品未使用の炭素短繊維でも、廃棄された炭素繊維をリサイクル処理して得られた炭素短繊維でもなんら問題は無い。炭素短繊維を得るのに必要なコストを考慮するとリサイクル処理して得られた炭素短繊維がより好ましい。 As the carbon short fiber, a carbon short fiber manufactured by any manufacturing method such as a PAN type or a pitch type can be used. Moreover, there is no problem even if it is a new unused carbon short fiber or a carbon short fiber obtained by recycling discarded carbon fiber. Considering the cost necessary to obtain the carbon short fiber, the carbon short fiber obtained by recycling treatment is more preferable.
炭素短繊維の平均繊維長は、１ｍｍ以上が好ましく、３ｍｍ以上がより好ましく、５ｍｍ以上が更に好ましい。炭素短繊維の平均繊維長が長いほど、炭素短繊維が結束を形成しやすく、樹脂の均一性が上がる傾向にある。平均繊維長の最大値は特に限定しないが、平均繊維長が長過ぎる場合、抄紙法でシート化する際に操業性が不安定となる場合があるため、１００ｍｍ未満であることが望ましい。 The average fiber length of the short carbon fibers is preferably 1 mm or more, more preferably 3 mm or more, and still more preferably 5 mm or more. As the average fiber length of the short carbon fibers is longer, the short carbon fibers tend to form a bundle and the uniformity of the resin tends to increase. The maximum value of the average fiber length is not particularly limited, but if the average fiber length is too long, the operability may become unstable when forming into a sheet by the papermaking method, and thus it is preferably less than 100 mm.
ここで、炭素短繊維の平均繊維長は以下の方法により求められる。まず、炭素短繊維をランダムに２０本採取し、その繊維長を測定する。その後以下の計算方法で炭素短繊維の平均繊維長を求める。 Here, the average fiber length of the short carbon fibers is obtained by the following method. First, 20 short carbon fibers are randomly collected and the fiber length is measured. Thereafter, the average fiber length of the short carbon fibers is determined by the following calculation method.
平均繊維長＝｛（炭素短繊維１の繊維長（ｍｍ））＋（炭素短繊維２の繊維長（ｍｍ））＋（炭素短繊維３の繊維長（ｍｍ））＋…（炭素短繊維２０の繊維長（ｍｍ））｝／２０ Average fiber length = {(fiber length of short carbon fiber 1 (mm)) + (fiber length of short carbon fiber 2 (mm)) + (fiber length of short carbon fiber 3 (mm)) +... (Short carbon fiber 20 Fiber length (mm))} / 20
結束を構成する炭素短繊維の平均繊維本数は、５００本／結束以下であることが好ましく、３００本／結束以下であることがより好ましい。該平均繊維本数は、「１０本以上の炭素短繊維で構成される結束」を対象としているので、該平均本数の好ましい下限値は１０本／結束である。結束を構成する炭素短繊維の平均繊維本数が５００本／結束超である場合、結束内部まで樹脂が浸透せず、結束内部の強度が非常に弱くなることから、ＣＦＲＰ加工後に欠点となる場合がある。 The average number of short carbon fibers constituting the bundle is preferably 500 fibers or less, more preferably 300 fibers or less. Since the average number of fibers is intended for “bundling composed of 10 or more short carbon fibers”, the preferred lower limit of the average number is 10 / binding. When the average number of short carbon fibers constituting the bundle is more than 500 / bundle, the resin does not penetrate into the inside of the bundle and the strength inside the bundle becomes very weak, which may be a defect after CFRP processing. is there.
本発明において、炭素短繊維湿式不織布が有する１０本以上の炭素短繊維で構成される結束は、５個／ｃｍ２以上であり、１０個／ｃｍ２以上であることがより好ましい。１０本以上の炭素短繊維で構成される結束が５個／ｃｍ２よりも少ない場合、炭素短繊維湿紙機不織布の密度が低くなり、樹脂を均一に浸透させることが難しくなる場合がある。 In the present invention, the bundle composed of 10 or more short carbon fibers of the short carbon fiber wet nonwoven fabric is 5 / cm 2 or more, and more preferably 10 / cm 2 or more. When the number of bundles composed of 10 or more carbon short fibers is less than 5 / cm 2 , the density of the carbon short fiber wet paper web nonwoven fabric may be low, and it may be difficult to uniformly penetrate the resin.
結束を構成する炭素短繊維の平均繊維本数を目視で測定することは極めて困難であることから、本発明では、以下の方法で結束を構成する炭素短繊維の平均繊維本数を求める。 Since it is extremely difficult to visually measure the average number of short carbon fibers constituting the bundle, in the present invention, the average number of short carbon fibers constituting the bundle is determined by the following method.
まず、炭素短繊維を電子顕微鏡（ＳＥＭ）撮影して、繊維一本辺りの断面積を測定する。次に、１０本以上の炭素短繊維で構成される結束を１００個ランダムに炭素短繊維湿式不織布から採取し、１００個の結束の合計質量を測定する。その後、以下の計算方法で、結束１００個の炭素短繊維本数の合計を求め、その平均値を求めることで、結束を構成する炭素短繊維の平均繊維本数［単位：本／結束］を算出する。 First, a short carbon fiber is photographed with an electron microscope (SEM), and a cross-sectional area around one fiber is measured. Next, 100 bundles composed of 10 or more carbon short fibers are randomly sampled from the carbon short fiber wet nonwoven fabric, and the total mass of the 100 bundles is measured. Thereafter, the total number of short carbon fibers of 100 bundles is obtained by the following calculation method, and the average value thereof is obtained to calculate the average number of carbon short fibers constituting the bundle [unit: book / bundle]. .
（炭素短繊維の断面積）×（炭素短繊維の平均繊維長）×（炭素短繊維密度）＝（炭素短繊維の一本あたりの質量） (Cross sectional area of short carbon fibers) x (average fiber length of short carbon fibers) x (short carbon fiber density) = (mass per short carbon fiber)
（結束１００個の質量の合計）÷（炭素短繊維の一本あたりの質量）＝（結束１００個の炭素短繊維本数の合計） (Total mass of 100 bundles) ÷ (mass per short carbon fiber) = (total number of short carbon fibers of 100 bundles)
（結束１００個の炭素短繊維本数の合計）÷１００＝（結束を構成する炭素短繊維の平均繊維本数） (Total number of short carbon fibers of 100 bundles) / 100 = (Average number of short carbon fibers constituting the bundle)
本発明の炭素短繊維湿式不織布においては、性能を阻害しない範囲で、セルロース繊維を使用することができる。セルロース繊維の種類としては針葉樹パルプ、広葉樹パルプなどの木材パルプ；藁パルプ、竹パルプ、リンターパルプ、ケナフパルプなどの木本類、草本類のパルプなどの天然パルプ繊維や、レーヨン、キュプラ、リヨセル等の再生セルロース繊維などが挙げられる。これらのセルロース繊維は、フィブリル化（叩解）されていてもなんら差し支えない。さらに、古紙、損紙などから得られる天然パルプ繊維を使用してもよい。 In the short carbon fiber wet nonwoven fabric of the present invention, cellulose fibers can be used as long as the performance is not impaired. Cellulose fiber types include wood pulp such as conifer pulp and hardwood pulp; wood pulp such as straw pulp, bamboo pulp, linter pulp and kenaf pulp; natural pulp fibers such as herbaceous pulp; rayon, cupra and lyocell Examples include regenerated cellulose fibers. These cellulose fibers may be fibrillated (beaten). Furthermore, natural pulp fibers obtained from waste paper, waste paper, etc. may be used.
上記セルロース繊維の中で針葉樹パルプ、リンターパルプ、及びリヨセルの群から選ばれる１種以上のセルロース繊維を使用することが好ましく、リヨセルを使用することがより好ましい。また、リヨセル繊維はフィブリル化（叩解）されていることが好ましい。これらの好ましいセルロース繊維を使用することによって、セルロース繊維を必須成分とする網状構造体が形成されやすくなり、繊維の脱落を抑制することができる。また、炭素短繊維湿式不織布を抄紙法で製造する場合の操業性が安定するという効果も得られる。 Among the cellulose fibers, it is preferable to use one or more cellulose fibers selected from the group of softwood pulp, linter pulp, and lyocell, and it is more preferable to use lyocell. The lyocell fiber is preferably fibrillated (beaten). By using these preferable cellulose fibers, it becomes easy to form a network structure having cellulose fibers as an essential component, and the dropping of the fibers can be suppressed. Moreover, the effect that the operativity at the time of manufacturing a carbon short fiber wet nonwoven fabric by a papermaking method is acquired is also acquired.
フィブリル化（叩解）セルロース繊維は、上記のセルロース繊維をフィブリル化することによって製造することができる。フィブリル化するための装置としては、ビーター、ＰＦＩミル、シングルディスクリファイナー（ＳＤＲ）、ダブルディスクリファイナー（ＤＤＲ）、また、顔料等の分散や粉砕に使用するボールミル、ダイノミル、ミキサー、摩砕装置、高速の回転刃により剪断力を与える回転刃式ホモジナイザー、高速で回転する円筒形の内刃と固定された外刃との間で剪断力を生じる二重円筒式の高速ホモジナイザー、超音波による衝撃で微細化する超音波破砕器、繊維懸濁液に少なくとも２０ＭＰａの圧力差を与えて小径のオリフィスを通過させて高速度とし、これを衝突させて急減速することにより繊維に剪断力、切断力を加える高圧ホモジナイザー等の装置が挙げられる。これらの装置を、単独又は組み合わせて用いることによって、フィブリル化セルロース繊維を製造することができる。そして、これらの装置の種類、処理条件（繊維濃度、温度、圧力、回転数、リファイナーの刃の形状、リファイナーのプレート間のギャップ、処理回数）等のフィブリル化条件の調整により、目的のフィブリル化状態を得ることができる。 The fibrillated (beaten) cellulose fiber can be produced by fibrillating the above cellulose fiber. Equipment for fibrillation includes beaters, PFI mills, single disc refiners (SDR), double disc refiners (DDR), ball mills, dyno mills, mixers, grinding devices used for dispersing and grinding pigments, etc. Rotating blade homogenizer that applies shearing force with a rotating blade, double-cylindrical high-speed homogenizer that generates shearing force between a cylindrical inner blade that rotates at high speed and a fixed outer blade, miniaturized by ultrasonic shock An ultrasonic crusher that applies a pressure difference of at least 20 MPa to the fiber suspension, passes through a small-diameter orifice to increase the speed, and collides with this to rapidly decelerate, thereby applying shearing force and cutting force to the fiber. Examples thereof include a homogenizer. By using these apparatuses alone or in combination, fibrillated cellulose fibers can be produced. The target fibrillation can be achieved by adjusting the fibrillation conditions such as the type of equipment and processing conditions (fiber concentration, temperature, pressure, rotation speed, refiner blade shape, gap between refiner plates, number of treatments), etc. The state can be obtained.
本発明の炭素短繊維湿式不織布においては、性能を阻害しない範囲で、バインダー合成繊維を使用することができる。バインダー合成繊維としては、芯鞘繊維（コアシェルタイプ）、並列繊維（サイドバイサイドタイプ）、放射状分割繊維などの複合繊維；未延伸繊維；低融点合成樹脂単繊維；熱水可溶性繊維等が挙げられる。バインダー合成繊維は、繊維全体又は繊維の一部のガラス転移温度又は溶融温度（融点）が低く、抄紙機の乾燥工程において、バインダー能力を発現する。複合繊維は、皮膜を形成しにくいので、炭素短繊維湿式不織布の空間を保持したまま、機械的強度を向上させることができる。より具体的には、複合繊維としては、ポリプロピレン（芯）とポリエチレン（鞘）の組み合わせ、ポリプロピレン（芯）とエチレンビニルアルコール（鞘）の組み合わせ、高融点ポリエステル（芯）と低融点ポリエステル（鞘）の組み合わせが挙げられる。未延伸繊維としては、ポリエステル等の未延伸繊維が挙げられる。また、ポリエチレンやポリプロピレン等の低融点樹脂のみで構成される単繊維（全融タイプ）等の低融点合成樹脂単繊維や、ポリビニルアルコール系のような熱水可溶性繊維は、乾燥工程で皮膜を形成しやすいが、本発明では使用することができる。本発明においては、熱水可溶性繊維であるポリビニルアルコール系のバインダー合成繊維が、炭素短繊維表面の官能基と水素結合を形成して強度を発揮しやすいため、好ましい。 In the short carbon fiber wet nonwoven fabric of the present invention, binder synthetic fibers can be used as long as the performance is not impaired. Examples of the binder synthetic fiber include composite fibers such as a core-sheath fiber (core-shell type), a parallel fiber (side-by-side type), and a radial split fiber; an unstretched fiber; a low-melting-point synthetic resin single fiber; The binder synthetic fiber has a low glass transition temperature or melting temperature (melting point) of the whole fiber or a part of the fiber, and expresses the binder ability in the drying process of the paper machine. Since the composite fiber hardly forms a film, the mechanical strength can be improved while maintaining the space of the short carbon fiber wet nonwoven fabric. More specifically, the composite fiber includes a combination of polypropylene (core) and polyethylene (sheath), a combination of polypropylene (core) and ethylene vinyl alcohol (sheath), a high-melting polyester (core) and a low-melting polyester (sheath). The combination of is mentioned. Examples of unstretched fibers include unstretched fibers such as polyester. Also, low melting point synthetic resin single fibers such as single fibers (fully fused type) composed only of low melting point resins such as polyethylene and polypropylene, and hot water soluble fibers such as polyvinyl alcohol form a film in the drying process. However, it can be used in the present invention. In the present invention, a polyvinyl alcohol-based binder synthetic fiber that is a hot water-soluble fiber is preferable because it forms a hydrogen bond with a functional group on the surface of the short carbon fiber and easily exhibits strength.
本発明では、合成繊維、無機繊維等を、炭素短繊維湿式不織布に配合することができる。例えば、ポリオレフィン系、ポリアミド系、ポリアクリル系、ビニロン系、ポリ塩化ビニリデン系、ポリ塩化ビニル系、ポリエステル系、ベンゾエート系、ポリクラール系、フェノール系などの合成繊維；ガラス繊維や岩石繊維、スラッグ繊維や金属繊維などの無機繊維が挙げられる。また、半合成繊維のアセテート、トリアセテート、プロミックス等も使用することができる。 In this invention, a synthetic fiber, an inorganic fiber, etc. can be mix | blended with a carbon short fiber wet nonwoven fabric. For example, synthetic fibers such as polyolefin, polyamide, polyacrylic, vinylon, polyvinylidene chloride, polyvinyl chloride, polyester, benzoate, polyclar, and phenol; glass fiber, rock fiber, slug fiber, etc. Examples thereof include inorganic fibers such as metal fibers. Semi-synthetic fibers such as acetate, triacetate, and promix can also be used.
合成繊維、無機繊維及び半合成繊維の繊維長は特に限定しないが、３ｍｍ以上３０ｍｍ未満であることが好ましい。合成繊維、無機繊維及び半合成繊維の繊維長が長いほど、一本あたりの繊維同士の接触点が多くなり、繊維が脱落しにくくなる傾向があるため、合成繊維、無機繊維及び半合成繊維の繊維長は３ｍｍ以上であることが好ましい。繊維長が長過ぎる場合は、抄紙性や不織布の地合いが悪化する場合があるため、３０ｍｍ未満であることが好ましい。繊維径についても特に限定しないが、１μｍ以上３０μｍ未満であることが好ましく、２μｍ以上２０μｍ未満であることが特に好ましい。繊維径が１μｍ未満の繊維を配合すると、炭素短繊維不織布内が密な構造になることから、例えば炭素短繊維不織布に樹脂を浸透させるなどの加工を行う際に樹脂の浸透を阻害し、性能が下がる場合がある。繊維径が３０μｍ以上である場合は、バインダー能力を持たない合成繊維又は無機繊維が脱落しやすい場合がある。 Although the fiber length of a synthetic fiber, an inorganic fiber, and a semi-synthetic fiber is not specifically limited, It is preferable that it is 3 mm or more and less than 30 mm. The longer the fiber length of the synthetic fiber, inorganic fiber and semi-synthetic fiber, the more contact points between the fibers, and the more difficult the fibers are to fall off. The fiber length is preferably 3 mm or more. When the fiber length is too long, the papermaking property and the texture of the nonwoven fabric may be deteriorated, and therefore, it is preferably less than 30 mm. Although it does not specifically limit about a fiber diameter, It is preferable that they are 1 micrometer or more and less than 30 micrometers, and it is especially preferable that they are 2 micrometers or more and less than 20 micrometers. When fibers with a fiber diameter of less than 1 μm are blended, the inside of the carbon short fiber nonwoven fabric has a dense structure. For example, when the resin is infiltrated into the carbon short fiber nonwoven fabric, the penetration of the resin is inhibited. May go down. When the fiber diameter is 30 μm or more, synthetic fibers or inorganic fibers that do not have binder ability may easily fall off.
本発明において、炭素短繊維不織布に含まれる全繊維に対して、炭素短繊維の含有量は１０〜９８質量％であり、２０〜９７質量％であることがより好ましく、３０〜９６質量％であることが更に好ましい。炭素短繊維の含有量が１０質量％未満である場合は、加工した際に炭素短繊維が持つ「強度が高く、質量が軽い」という効果が十分に発揮できない場合がある。炭素短繊維の含有量が９８質量％よりも多い場合は、繊維同士の結着が不十分となり、脱落繊維が発生する場合がある。 In the present invention, the content of carbon short fibers is 10 to 98% by mass, more preferably 20 to 97% by mass, and more preferably 30 to 96% by mass with respect to the total fibers contained in the carbon short fiber nonwoven fabric. More preferably it is. When the content of the short carbon fiber is less than 10% by mass, there may be a case where the effect of “high strength and light mass” of the short carbon fiber cannot be sufficiently exhibited when processed. When the content of short carbon fibers is more than 98% by mass, the binding between the fibers becomes insufficient, and dropped fibers may be generated.
本発明では、炭素短繊維は抄紙機でシート化される。すなわち、抄紙法で炭素短繊維湿式不織布を製造する。 In the present invention, the short carbon fibers are formed into a sheet by a paper machine. That is, a short carbon fiber wet nonwoven fabric is produced by a papermaking method.
抄紙法では、例えば、長網式、円網式、傾斜ワイヤー式を用いることができる。これらの抄紙方式を単独で有する抄紙機を使用しても良いし、同種又は異種の２機以上の抄紙方式がオンラインで設置されているコンビネーション抄紙機を使用しても良い。均一性に優れた炭素短繊維湿式不織布を製造するには、長網式、傾斜ワイヤー式のように、緩やかに、ワイヤー上のスラリーから脱水することができる抄紙方式を使用することが好ましい。本発明の炭素短繊維湿式不織布は、単層であっても良いし、複層であっても良い。 In the papermaking method, for example, a long net type, a circular net type, and an inclined wire type can be used. A paper machine having these paper systems alone may be used, or a combination paper machine in which two or more same or different types of paper machines are installed online may be used. In order to produce a short carbon fiber wet nonwoven fabric excellent in uniformity, it is preferable to use a papermaking method that can be slowly dehydrated from the slurry on the wire, such as a long-mesh type or an inclined wire type. The short carbon fiber wet nonwoven fabric of the present invention may be a single layer or a multilayer.
抄紙法において、炭素短繊維やその他の繊維を分散することを目的に、パルパーでの離解作業を行う。パルパーの種類は特に限定しておらず、縦型パルパーを使用しても良いし、横型パルパーを使用しても良いし、その他の形式のパルパーでもなんら問題は無い。パルパーの離解能力も特に限定していないが、パルパーの離解能力が強すぎる場合、炭素短繊維の結束を全て離解してしまう場合があり、パルパーの離解能力が弱すぎる場合、炭素短繊維が全く離解せずに、大きな結束が不織布に残り、結束を構成する炭素短繊維の平均繊維本数が５００本／結束を超える場合がある。炭素短繊維の離解の状態については、パルパーの強度、時間を調節することでコントロールすることが望ましい。 In the papermaking method, disintegration work is performed with a pulper for the purpose of dispersing short carbon fibers and other fibers. The type of the pulper is not particularly limited, and a vertical pulper may be used, a horizontal pulper may be used, and there is no problem with other types of pulpers. The dispersibility of the pulper is not particularly limited, but if the dispersibility of the pulper is too strong, all the short carbon fiber bundles may be disaggregated. Without being disaggregated, a large bundle may remain in the nonwoven fabric, and the average number of short carbon fibers constituting the bundle may exceed 500 / bundling. It is desirable to control the disaggregation state of the short carbon fibers by adjusting the strength and time of the pulper.
抄紙法において、繊維を均一に水中に分散させる目的や各種機能を付与する目的で、繊維を水中に分散する際に、各種アニオン性、ノニオン性、カチオン性、あるいは両性の分散剤、消泡剤、親水剤、濾水剤、紙力向上剤、粘剤、帯電防止剤、高分子粘剤、離型剤、抗菌剤、殺菌剤、ｐＨ調整剤、ピッチコントロール剤、スライムコントロール剤等の薬品を添加する場合もある。 Various anionic, nonionic, cationic or amphoteric dispersants and antifoaming agents are used to disperse fibers in water for the purpose of uniformly dispersing the fibers in water and imparting various functions in the papermaking process. , Hydrophilic agents, drainage agents, paper strength improvers, adhesives, antistatic agents, polymer adhesives, mold release agents, antibacterial agents, bactericides, pH adjusters, pitch control agents, slime control agents, etc. Sometimes added.
本発明の炭素短繊維湿式不織布には、必要に応じてサイズ剤を配合することができる。サイズ剤としては、本発明の所望の効果を損なわないものであれば、強化ロジンサイズ剤、ロジンエマルジョンサイズ剤、石油樹脂系サイズ剤、合成サイズ剤、中性ロジンサイズ剤、アルキルケテンダイマー（ＡＫＤ）などのサイズ剤の中からいずれをも用いることができる。 A sizing agent can be blended with the short carbon fiber wet nonwoven fabric of the present invention as necessary. As the sizing agent, any reinforced rosin sizing agent, rosin emulsion sizing agent, petroleum resin sizing agent, synthetic sizing agent, neutral rosin sizing agent, alkyl ketene dimer (AKD) may be used as long as the desired effect of the present invention is not impaired. Any of sizing agents such as) can be used.
抄紙機で製造された湿紙を、ヤンキードライヤー、エアードライヤー、シリンダードライヤー、サクションドラム式ドライヤー、赤外方式ドライヤー等で乾燥することにより、炭素短繊維湿式不織布を得る。湿紙の乾燥の際に、ヤンキードライヤー等の熱ロールに密着させて熱圧乾燥させることによって、密着させた面の平滑性が向上する。熱圧乾燥とは、タッチロール等で熱ロールに湿紙を押しつけて乾燥させることをいう。熱ロールの表面温度は、１００〜１８０℃が好ましく、１００〜１６０℃がより好ましく、１１０〜１６０℃が更に好ましい。圧力は、好ましくは５０〜１０００Ｎ／ｃｍであり、より好ましくは１００〜８００Ｎ／ｃｍである。 The wet paper manufactured by the paper machine is dried with a Yankee dryer, an air dryer, a cylinder dryer, a suction drum dryer, an infrared dryer, or the like to obtain a short carbon fiber wet nonwoven fabric. When the wet paper is dried, it is brought into close contact with a hot roll such as a Yankee dryer and dried by heat and pressure to improve the smoothness of the contacted surface. Hot-pressure drying means that the wet paper is pressed against the heat roll with a touch roll or the like and dried. The surface temperature of the hot roll is preferably 100 to 180 ° C, more preferably 100 to 160 ° C, and still more preferably 110 to 160 ° C. The pressure is preferably 50 to 1000 N / cm, more preferably 100 to 800 N / cm.
本発明の炭素短繊維湿式不織布の坪量は、特に限定しないが、１０ｇ／ｍ２以上３５０ｇ／ｍ２未満が好ましく、３０ｇ／ｍ２以上３００ｇ／ｍ２未満がより好ましい。坪量が１０ｇ／ｍ２未満では、不織布の密度が低くなる傾向にあり、またＣＦＲＰ加工時に多数の不織布を重ねる必要があり、樹脂の浸透量に表裏差が発生しやすくなることから、ＣＦＲＰの均一性を損ねる可能性がある。坪量が３５０ｇ／ｍ２以上では、ドライヤーでの乾燥の際に均一に乾燥することが難しく、炭素短繊維湿式不織布の品質にムラが生じる場合がある。 The basis weight of the short carbon fibers wet-laid nonwoven fabric of the present invention is not particularly limited, but is preferably less than 10 g / m 2 or more 350 g / m 2, less than 30 g / m 2 or more 300 g / m 2 is more preferable. If the basis weight is less than 10 g / m 2 , the density of the nonwoven fabric tends to be low, and a large number of nonwoven fabrics must be stacked at the time of CFRP processing. Uniformity may be impaired. When the basis weight is 350 g / m 2 or more, it is difficult to dry uniformly with a dryer, and the quality of the short carbon fiber wet nonwoven fabric may be uneven.
本発明の炭素短繊維湿式不織布の密度は、０．１２ｇ／ｃｍ３以上であることが好ましく、０．１５ｇ／ｃｍ３以上であることがより好ましい。密度が０．１２ｇ／ｃｍ３未満では炭素短繊維湿式不織布内の空隙が多く、樹脂を塗工した際に裏面まで樹脂が浸透しないことから、ＣＦＲＰの品質に表裏差が発生する場合がある。密度の上限値は特に限定しないが、０．５ｇ／ｃｍ３未満であることが好ましく、０．４ｇ／ｃｍ３未満であることがより好ましい。密度が０．５ｇ／ｃｍ３以上では、樹脂の浸透が阻害され、樹脂の裏面まで樹脂が浸透しないことから、ＣＦＲＰ加工後の強度にムラが生じる場合がある。 The density of the short carbon fiber wet nonwoven fabric of the present invention is preferably 0.12 g / cm 3 or more, and more preferably 0.15 g / cm 3 or more. When the density is less than 0.12 g / cm 3 , there are many voids in the short carbon fiber wet nonwoven fabric, and when the resin is applied, the resin does not permeate to the back surface. The upper limit of the density is not particularly limited, but is preferably less than 0.5 g / cm 3 and more preferably less than 0.4 g / cm 3 . When the density is 0.5 g / cm 3 or more, the penetration of the resin is inhibited and the resin does not penetrate to the back surface of the resin, so that unevenness may occur in the strength after CFRP processing.
以下、実施例によって本発明を更に詳しく説明するが、本発明はこの実施例に限定されるものではない。なお、実施例中の部数や百分率は質量基準である。 EXAMPLES Hereinafter, although an Example demonstrates this invention in more detail, this invention is not limited to this Example. In addition, the number of parts and percentage in an Example are based on mass.
実施例１
炭素短繊維（平均繊維長５ｍｍ）と叩解した叩解リヨセル繊維とＰＶＡバインダー繊維（クラレ製、製品名：ＶＰＢ１０７−１）とを、表１記載の配合比率（質量基準）で水に投入して、縦型パルパーで１０分間混合分散した後、湿紙を傾斜ワイヤー方式で、一層抄きで湿式抄紙し、表面温度１３０℃のヤンキードライヤーで乾燥し、抄紙速度２０ｍ／ｍｉｎで、坪量５０ｇ／ｍ２の炭素短繊維湿式不織布を得た。
Example 1
A short carbon fiber (average fiber length of 5 mm), a beaten lyocell fiber and a PVA binder fiber (manufactured by Kuraray, product name: VPB107-1) were poured into water at a blending ratio (mass basis) shown in Table 1, After mixing and dispersing with a vertical pulper for 10 minutes, wet paper is wet-papered with a slanted wire method, one-sided papermaking, dried with a Yankee dryer with a surface temperature of 130 ° C., paper making speed of 20 m / min, basis weight of 50 g / m 2 carbon short fiber wet nonwoven fabric was obtained.
実施例２〜４
繊維の分散時間を表１記載内容に変えた以外は、実施例１と同様に実施例２〜４の炭素短繊維湿式不織布を得た。
Examples 2-4
Except for changing the fiber dispersion time to the content described in Table 1, the short carbon fiber wet nonwoven fabrics of Examples 2 to 4 were obtained in the same manner as in Example 1.
比較例１〜４
繊維の分散時間を表１記載内容に変えた以外は、実施例１と同様に比較例１〜４の炭素短繊維湿式不織布を得た。
Comparative Examples 1-4
The short carbon fiber wet nonwoven fabrics of Comparative Examples 1 to 4 were obtained in the same manner as in Example 1 except that the fiber dispersion time was changed to the content described in Table 1.
実施例５及び６
炭素短繊維湿式不織布の配合を表１記載内容に変えた以外は、実施例１と同様に実施例５及び６の炭素短繊維湿式不織布を得た。
Examples 5 and 6
The carbon short fiber wet nonwoven fabrics of Examples 5 and 6 were obtained in the same manner as in Example 1 except that the composition of the carbon short fiber wet nonwoven fabric was changed to the content described in Table 1.
実施例７及び８
炭素短繊維湿式不織布の配合を表１記載内容に変えた以外は、実施例１と同様に実施例７及び８の炭素短繊維湿式不織布を得た。
Examples 7 and 8
The carbon short fiber wet nonwoven fabrics of Examples 7 and 8 were obtained in the same manner as in Example 1 except that the composition of the carbon short fiber wet nonwoven fabric was changed to the contents described in Table 1.
実施例９〜１２
炭素短繊維湿式不織布の坪量を表１記載内容に変えた以外は、実施例１と同様に実施例９〜１２の炭素短繊維湿式不織布を得た。
Examples 9-12
The carbon short fiber wet nonwoven fabrics of Examples 9 to 12 were obtained in the same manner as in Example 1 except that the basis weight of the carbon short fiber wet nonwoven fabric was changed to the contents described in Table 1.
比較例５
炭素短繊維湿式不織布の坪量を表１記載内容に変えた以外は、実施例１と同様に比較例５の炭素短繊維湿式不織布を得た。
Comparative Example 5
A carbon short fiber wet nonwoven fabric of Comparative Example 5 was obtained in the same manner as in Example 1 except that the basis weight of the carbon short fiber wet nonwoven fabric was changed to the content described in Table 1.
実施例１３〜１６
炭素短繊維の平均繊維長を表１記載内容に変えた以外は、実施例１と同様に実施例１３〜１６の炭素短繊維湿式不織布を得た。
Examples 13-16
Except for changing the average fiber length of the short carbon fibers to the content described in Table 1, the short carbon fiber wet nonwoven fabrics of Examples 13 to 16 were obtained in the same manner as in Example 1.
実施例１７〜２２
炭素短繊維湿式不織布の配合を表１記載内容に変えた以外は、実施例１と同様に実施例１７〜２２の炭素短繊維湿式不織布を得た。
Examples 17-22
The carbon short fiber wet nonwoven fabrics of Examples 17 to 22 were obtained in the same manner as in Example 1 except that the composition of the carbon short fiber wet nonwoven fabric was changed to the contents described in Table 1.
表１に記載されている繊維の詳細は、以下のとおりである。 Details of the fibers described in Table 1 are as follows.
叩解リヨセル：リヨセル繊維（繊度１．４ｄｔｅｘ、繊維長３ｍｍ）を、ダブルディスクリファイナーを用いて処理し、平均繊維径１４．０μｍの幹部から平均繊維径１μｍ以下の枝部を発生させるように調製した繊維。
叩解針葉樹パルプ：ろ水度５００ｍｌＣＳＦとなるように調製した天然針葉樹パルプ。
ＰＥＴ繊維：繊度１．７デシテックス、繊維長 ５ｍｍ
アラミド繊維：繊度０．９デシテックス、繊維長 ５ｍｍ
ＰＥＴバインダー：ポリエチレンテレフタレート（ＰＥＴ）未延伸バインダー繊維、繊度１．２デシテックス、繊維長５ｍｍ
Beating lyocell: A lyocell fiber (fineness: 1.4 dtex, fiber length: 3 mm) was prepared using a double disc refiner to produce branches having an average fiber diameter of 1 μm or less from a trunk having an average fiber diameter of 14.0 μm. fiber.
Beating conifer pulp: natural conifer pulp prepared to a freeness of 500 ml CSF.
PET fiber: Fineness 1.7 decitex, fiber length 5mm
Aramid fiber: Fineness 0.9 dtex, fiber length 5 mm
PET binder: Polyethylene terephthalate (PET) unstretched binder fiber, fineness 1.2 dtex, fiber length 5 mm
実施例及び比較例において、作製した炭素短繊維湿式不織布において、結束の個数、結束を構成する炭素短繊維の平均繊維本数及び密度を測定し、また、樹脂の浸透性及び抄紙性を評価し、測定結果及び評価結果を表１に示した。 In Examples and Comparative Examples, in the produced short carbon fiber wet nonwoven fabric, the number of bundles, the average number of short carbon fibers constituting the bundle and the density were measured, and the resin permeability and papermaking properties were evaluated. The measurement results and evaluation results are shown in Table 1.
＜炭素繊維結束の個数＞
炭素短繊維湿紙不織布を１ｃｍ×１ｃｍ角に断裁したものを１０個採取し、そのヤンキードライヤー接触面を光学顕微鏡で観察し、繊維結束の個数を測定してその平均値を求めた。
<Number of carbon fiber bundles>
Ten pieces of carbon short fiber wet paper nonwoven fabric cut into 1 cm × 1 cm squares were collected, the contact surface of the Yankee dryer was observed with an optical microscope, the number of fiber bundles was measured, and the average value was obtained.
＜炭素短繊維結束の平均繊維本数＞
炭素短繊維湿式不織布からピンセットで繊維結束部分を１００個採取し、その質量から結束を構成する炭素短繊維の平均繊維本数を求めた。
<Average number of short carbon fiber bundles>
100 fiber bundle portions were collected from the short carbon fiber wet nonwoven fabric with tweezers, and the average number of short carbon fibers constituting the bundle was determined from the mass.
＜密度＞
炭素短繊維湿式不織布の坪量をＪＩＳ Ｐ ８１２４：２０１１に則って測定した。また、厚みは、テクロック製厚み計（測定子直径１６ｍｍ、測定荷重５Ｎ）で測定した。得られた坪量及び厚みから密度を求めた。
<Density>
The basis weight of the short carbon fiber wet nonwoven fabric was measured according to JIS P 8124: 2011. Further, the thickness was measured with a TECLOCK thickness gauge (measuring element diameter 16 mm, measurement load 5 N). The density was calculated | required from the obtained basic weight and thickness.
＜樹脂浸透性 裏面＞
炭素短繊維湿式不織布に、炭素短繊維湿式不織布の二倍量の熱硬化型エポキシ樹脂を表面塗工し、裏面まで樹脂が浸透するか否かを評価した。
<Resin permeability>
The surface of the short carbon fiber wet nonwoven fabric was coated with a thermosetting epoxy resin twice the amount of the short carbon fiber wet nonwoven fabric, and whether or not the resin penetrated to the back surface was evaluated.
○：樹脂が裏面まで多く浸透した。
△：樹脂が裏面までわずかに浸透した。
×：樹脂が裏面まで浸透しなかった。
○: A lot of resin penetrated to the back side.
Δ: The resin slightly penetrated to the back surface.
X: The resin did not penetrate to the back surface.
＜樹脂浸透性 結束内部＞
樹脂を塗工後、１３０℃で２０分間加熱して樹脂を硬化させたＣＦＲＰの断面をＳＥＭで観察し、炭素短繊維の結束内部における樹脂の浸透状態を観察し、評価を行った。
<Resin permeability inside the bundle>
After coating the resin, the cross section of the CFRP cured by heating at 130 ° C. for 20 minutes was observed with an SEM, and the penetration state of the resin inside the short carbon fiber bundle was observed and evaluated.
○：樹脂が結束内部まで満遍なく浸透した。
△：結束内部にわずかに空隙が見られた。
×：結束内部に空隙が見られた。
○: The resin penetrated evenly into the bundle.
Δ: Slight voids were observed inside the bundle.
X: A void was observed inside the bundle.
＜抄紙性＞
炭素短繊維湿式不織布を抄紙する際に問題が発生するか否かを確認した。
○：抄紙した際に問題が見られなかった。
△：抄紙した際に問題がわずかに見られた
×：抄紙した際に問題が多く見られた。
<Making paper>
It was confirmed whether or not a problem occurred when papermaking a short carbon fiber wet nonwoven fabric.
○: No problem was found when paper was made.
Δ: Slight problems were observed when paper was made. ×: Many problems were observed when paper was made.
炭素短繊維の含有量が１０質量％〜９８質量％であり、不織布の密度が０．１２ｇ／ｃｍ３以上であり、１０本以上の炭素短繊維で構成される結束を５個／ｃｍ２以上有し、該結束を構成する炭素短繊維の平均繊維本数が５００本／結束以下であることを特徴とする炭素短繊維湿式不織布である実施例１〜４においては、裏面にも、結束内部にも樹脂が浸透しており、優れた炭素短繊維湿式不織布であることが分かる。また、実施例１及び２の結果から、パルパーでの離解時間を短くすることで、結束を構成する炭素短繊維の平均繊維本数が多くなって結束が大きくなり、その結果、結束の内部までやや樹脂が浸透しづらくなっていることが分かる。また、実施例１及び４の結果から、パルパーでの離解時間を長くすることで、結束を構成する炭素短繊維の平均繊維本数が少なくなって結束が小さくなり、その結果、炭素短繊維湿式不織布の密度が低くなることから、樹脂が浸透しづらくなっていることが分かる。 The content of carbon short fibers is 10% by mass to 98% by mass, the density of the nonwoven fabric is 0.12 g / cm 3 or more, and the number of bundles composed of 10 or more carbon short fibers is 5 / cm 2 or more. In Examples 1 to 4, which are carbon short fiber wet nonwoven fabrics characterized in that the average number of short carbon fibers constituting the bundle is 500 per bundle or less, It can be seen that the resin has penetrated and is an excellent short carbon fiber wet nonwoven fabric. In addition, from the results of Examples 1 and 2, by shortening the disaggregation time in the pulper, the average number of short carbon fibers constituting the bundling is increased and the bundling is increased. It can be seen that the resin is difficult to penetrate. Further, from the results of Examples 1 and 4, by increasing the disaggregation time in the pulper, the average number of short carbon fibers constituting the bundling is reduced and the bundling is reduced. As a result, the short carbon fiber wet nonwoven fabric is obtained. From the fact that the density of the resin becomes low, it can be seen that it is difficult for the resin to penetrate.
これに対し、比較例１及び２では、離解時間が短いことから、炭素短繊維の離解が不十分であるため、結束を構成する炭素短繊維の平均繊維本数が５００本／結束よりも多く、結束内部まで樹脂が浸透していない様子が確認された。結束内部まで樹脂が浸透していないため、ＣＦＲＰ内に強度が弱い箇所が存在することとなり、その箇所から破壊が起こる場合があるため、ＣＦＲＰとしては適さない場合がある。また、抄紙の際に、繊維本数の多い結束がタンクや配管に堆積する傾向にあるため、抄紙の際に問題が発生した。 On the other hand, in Comparative Examples 1 and 2, since the disaggregation time is short, the disaggregation of the short carbon fibers is insufficient, so the average number of short carbon fibers constituting the bundling is more than 500 / bundling, It was confirmed that the resin did not penetrate into the inside of the bundle. Since the resin does not penetrate into the inside of the bundle, there is a portion having a low strength in the CFRP, and there is a case where the breakage may occur from that portion. In addition, when making paper, there was a tendency for bundles with a large number of fibers to accumulate in tanks and piping, which caused problems during paper making.
比較例３及び４では、離解時間が長いため、炭素短繊維がほぼ完全に離解し、結束数が少ない様子が確認された。比較例３では、１０本以上の炭素短繊維で構成される結束が１個／ｃｍ２であり、比較例４では、０個／ｃｍ２であった。そのため、炭素短繊維湿式不織布は複雑な立体構造を形成し、密度も低くなっており、比較例４の炭素短繊維湿式不織布の密度は０．１２ｇ／ｃｍ３未満であった。これにより、裏面まで樹脂が浸透しないという結果となった。樹脂が裏面まで浸透しないことから、ＣＦＲＰ加工の際に樹脂の濃度勾配が発生する場合があり、品質が安定しないことから、ＣＦＲＰとしては適さない場合がある。また、結束数の少ない不織布は、抄紙の際に多く水分を含む傾向にあることから乾燥が不十分となり、抄紙の際に問題が発生した。 In Comparative Examples 3 and 4, since the disaggregation time was long, it was confirmed that the short carbon fibers were almost completely disaggregated and the number of bundles was small. In Comparative Example 3, the number of bundles composed of 10 or more carbon short fibers was 1 / cm 2 , and in Comparative Example 4, it was 0 / cm 2 . Therefore, the short carbon fiber wet nonwoven fabric formed a complicated three-dimensional structure, and the density was low. The density of the short carbon fiber wet nonwoven fabric of Comparative Example 4 was less than 0.12 g / cm 3 . This resulted in the resin not penetrating to the back side. Since the resin does not penetrate to the back surface, a concentration gradient of the resin may occur during CFRP processing, and the quality may not be stable, so that it may not be suitable as CFRP. Moreover, since the nonwoven fabric with a small number of bundles tends to contain a large amount of moisture during papermaking, drying is insufficient, and a problem occurs during papermaking.
炭素短繊維の含有量が１０質量％〜９８質量％であり、不織布の密度が０．１２ｇ／ｃｍ３以上であり、１０本以上の炭素短繊維で構成される結束を５個／ｃｍ２以上有し、該結束を構成する炭素短繊維の平均繊維本数が５００本／結束以下であることを特徴とする炭素短繊維湿式不織布である実施例５及び６においては、裏面にも、結束内部にも樹脂が浸透しており、優れた炭素短繊維湿式不織布であることが分かる。また、実施例１の叩解リヨセルを叩解針葉樹パルプに変えた実施例５の結果及び実施例１のＰＶＡバインダー合成繊維をＰＥＴバインダー合成繊維に変更した実施例６の結果から、炭素短繊維以外の繊維を実施例１記載の繊維以外の繊維に変更しても問題が無いことが分かる。 The content of carbon short fibers is 10% by mass to 98% by mass, the density of the nonwoven fabric is 0.12 g / cm 3 or more, and the number of bundles composed of 10 or more carbon short fibers is 5 / cm 2 or more. In Examples 5 and 6 which are short carbon fiber wet nonwoven fabrics characterized in that the average number of short carbon fibers constituting the bundling is 500 / bundling or less, It can be seen that the resin has penetrated and is an excellent short carbon fiber wet nonwoven fabric. From the results of Example 5 in which the beating lyocell of Example 1 was changed to beating conifer pulp and the results of Example 6 in which the PVA binder synthetic fiber of Example 1 was changed to a PET binder synthetic fiber, fibers other than carbon short fibers It turns out that there is no problem even if it changes to fibers other than the fiber of Example 1.
炭素短繊維の含有量が１０質量％〜９８質量％であり、不織布の密度が０．１２ｇ／ｃｍ３以上であり、１０本以上の炭素短繊維で構成される結束を５個／ｃｍ２以上有し、該結束を構成する炭素短繊維の平均繊維本数が５００本／結束以下であることを特徴とする炭素短繊維湿式不織布である実施例７及び８においては、裏面にも、結束内部にも樹脂が浸透しており、優れた炭素短繊維湿式不織布であることが分かる。合成繊維としてＰＥＴ繊維又はアラミド繊維が配合されている実施例７及び８においても、樹脂の浸透性に問題が見られないことから、合成繊維を配合しても樹脂の浸透性に影響は無い様子が確認された。 The content of carbon short fibers is 10% by mass to 98% by mass, the density of the nonwoven fabric is 0.12 g / cm 3 or more, and the number of bundles composed of 10 or more carbon short fibers is 5 / cm 2 or more. In Examples 7 and 8 which are carbon short fiber wet nonwoven fabrics characterized in that the average number of short carbon fibers constituting the bundling is 500 / bundling or less, It can be seen that the resin has penetrated and is an excellent short carbon fiber wet nonwoven fabric. Even in Examples 7 and 8 in which PET fiber or aramid fiber is blended as a synthetic fiber, there is no problem in the permeability of the resin, so there is no influence on the permeability of the resin even if the synthetic fiber is blended Was confirmed.
炭素短繊維の含有量が１０質量％〜９８質量％であり、不織布の密度が０．１２ｇ／ｃｍ３以上であり、１０本以上の炭素短繊維で構成される結束を５個／ｃｍ２以上有し、該結束を構成する炭素短繊維の平均繊維本数が５００本／結束以下であることを特徴とする炭素短繊維湿式不織布である実施例９〜１２においては、裏面にも、結束内部にも樹脂が浸透しており、優れた炭素短繊維湿式不織布であることが分かる。坪量が３５０ｇ／ｍ２以上である実施例１２においては、湿式抄造の際に均一に乾燥させることが難しく、品質に表裏差が出やすく、また、高密度となったことにより、樹脂がやや浸透しにくいという結果となった。 The content of carbon short fibers is 10% by mass to 98% by mass, the density of the nonwoven fabric is 0.12 g / cm 3 or more, and the number of bundles composed of 10 or more carbon short fibers is 5 / cm 2 or more. In Examples 9-12, which are carbon short fiber wet nonwoven fabrics, the average number of short carbon fibers constituting the bundling is 500 / bundling or less. It can be seen that the resin has penetrated and is an excellent short carbon fiber wet nonwoven fabric. In Example 12 having a basis weight of 350 g / m 2 or more, it is difficult to dry uniformly during wet papermaking, and the quality tends to be different between the front and the back, and the resin has become somewhat dense due to high density. As a result, it was difficult to penetrate.
比較例５では、坪量を下げたことにより、１０本以上の炭素短繊維で構成される結束が５個／ｃｍ２よりも少なくなり、また、密度も低くなることから、樹脂が裏面まで浸透しなくなり、ＣＦＲＰ加工の際に樹脂の濃度勾配が発生する場合があり、品質が安定しないことから、ＣＦＲＰとしては適さない場合がある。また、抄紙の際に紙切れが頻発することから、抄紙性にも劣る結果となった。炭素短繊維湿式不織布の坪量が小さいほど、低密度になる傾向にあることから、坪量は１０ｇ／ｍ２以上であることが好ましいことが分かる。 In Comparative Example 5, by reducing the basis weight, the number of bundles composed of 10 or more carbon short fibers is less than 5 pieces / cm 2 , and the density is also low, so that the resin penetrates to the back surface. In some cases, a concentration gradient of the resin may occur during CFRP processing, and the quality is not stable. In addition, paper cutting frequently occurred during papermaking, resulting in poor papermaking properties. It can be seen that the basis weight is preferably 10 g / m 2 or more because the smaller the basis weight of the short carbon fiber non-woven fabric, the lower the density.
炭素短繊維の含有量が１０質量％〜９８質量％であり、不織布の密度が０．１２ｇ／ｃｍ３以上であり、１０本以上の炭素短繊維で構成される結束を５個／ｃｍ２以上有し、該結束を構成する炭素短繊維の平均繊維本数が５００本／結束以下であることを特徴とする炭素短繊維湿式不織布である実施例１３〜１６においては、裏面にも、結束内部にも樹脂が浸透しており、優れた炭素短繊維湿式不織布であることが分かる。炭素短繊維の平均繊維長が短い実施例１３においては、繊維同士が絡みにくいことから結束を形成しにくく、結束の少ない炭素短繊維湿式不織布は複雑な立体構造の低密度な不織布となる傾向であるため、樹脂がやや浸透しづらい様子が確認された。炭素短繊維の平均繊維長が長い実施例１６においては、抄造時に抄紙機の凹凸部に繊維が堆積しやすい傾向が見られ、抄造性が少し劣る結果となった。 The content of carbon short fibers is 10% by mass to 98% by mass, the density of the nonwoven fabric is 0.12 g / cm 3 or more, and the number of bundles composed of 10 or more carbon short fibers is 5 / cm 2 or more. In Examples 13 to 16, which are carbon short fiber wet nonwoven fabrics characterized in that the average number of short carbon fibers constituting the bundling is 500 / bundling or less, It can be seen that the resin has penetrated and is an excellent short carbon fiber wet nonwoven fabric. In Example 13 in which the average fiber length of the short carbon fibers is short, the fibers are not easily entangled with each other, making it difficult to form a bundle, and the short carbon fiber wet nonwoven fabric tends to be a low-density nonwoven fabric having a complicated three-dimensional structure. For this reason, it was confirmed that the resin was slightly difficult to penetrate. In Example 16 in which the average fiber length of the short carbon fibers was long, there was a tendency for fibers to be easily deposited on the uneven portions of the paper machine during paper making, and the paper making properties were slightly inferior.
炭素短繊維の含有量が１０質量％〜９８質量％であり、不織布の密度が０．１２ｇ／ｃｍ３以上であり、１０本以上の炭素短繊維で構成される結束を５個／ｃｍ２以上有し、該結束を構成する炭素短繊維の平均繊維本数が５００本／結束以下であることを特徴とする炭素短繊維湿式不織布である実施例１７〜２２においては、裏面にも、繊維結束内部にも樹脂が浸透しており、優れた炭素短繊維湿式不織布であることが分かる。ただし、炭素短繊維の含有量が１０質量％である実施例１７においては、微細な叩解リヨセル及び合成繊維が多く配合されていることから、樹脂がやや浸透しづらいことが分かる。また、炭素短繊維の含有量が９８質量％である実施例２２においては、樹脂の浸透性には全く問題は無いものの、抄紙の際にわずかに脱落繊維が発生することからやや問題があった。 The content of carbon short fibers is 10% by mass to 98% by mass, the density of the nonwoven fabric is 0.12 g / cm 3 or more, and the number of bundles composed of 10 or more carbon short fibers is 5 / cm 2 or more. In Examples 17 to 22, which are wet short nonwoven fabrics of carbon short fibers characterized in that the average number of short carbon fibers constituting the bundling is 500 / bundling or less, It can be seen that the resin is infiltrated, and is an excellent short carbon fiber wet nonwoven fabric. However, in Example 17 in which the content of short carbon fibers is 10% by mass, it can be seen that the resin is a little difficult to penetrate because a large amount of fine beating lyocell and synthetic fibers are blended. Further, in Example 22 in which the content of short carbon fibers was 98% by mass, there was no problem in the permeability of the resin, but there was a slight problem because the fibers dropped slightly during paper making. .
本発明によれば、ＣＦＲＰに加工する際に、樹脂が短時間で、且つ均一に浸透する炭素短繊維湿式不織布を得ることができる。 According to the present invention, when processing into CFRP, a short carbon fiber wet nonwoven fabric in which the resin permeates uniformly in a short time can be obtained.
１ 炭素短繊維結束（結束を構成する炭素短繊維の繊維本数が５００本／結束以下）
２ 炭素短繊維結束（結束を構成する炭素短繊維の繊維本数が５００本／結束超）
1 Short carbon fiber bundling (the number of short carbon fibers constituting the bundling is 500 / bundling or less)
2 Short carbon fiber bundling (the number of short carbon fibers constituting the bundling is 500 / bundling)
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| JP2021183743A (en) * | 2020-05-22 | 2021-12-02 | 三菱製紙株式会社 | Carbon fiber-contained wet-type non-woven fabric |
| JP2022070291A (en) * | 2020-10-27 | 2022-05-13 | 三菱製紙株式会社 | Carbon fiber-containing wet type unwoven fabric |
| WO2022265099A1 (en) * | 2021-06-18 | 2022-12-22 | 三菱ケミカル株式会社 | Self-assembled carbon fiber bundles, method for producing same, prepreg and method for producing same |
| JP7564415B2 (en) | 2020-06-09 | 2024-10-09 | オリベスト株式会社 | Manufacturing method of high density carbon fiber nonwoven fabric |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10292254A (en) * | 1997-04-10 | 1998-11-04 | Oji Paper Co Ltd | Wet nonwoven fabric for frp |
| JP2004323992A (en) * | 2003-04-22 | 2004-11-18 | Oji Paper Co Ltd | Nonwoven fabric by wet method and method for producing the same |
| JP2004353124A (en) * | 2003-05-29 | 2004-12-16 | Mitsubishi Paper Mills Ltd | Nonwoven fabric of carbon fiber and method for producing the same |
| JP3152748U (en) * | 2009-05-31 | 2009-08-13 | エアテクス株式会社 | Carbon nonwoven fabric |
| JP2017106130A (en) * | 2015-12-08 | 2017-06-15 | 三菱製紙株式会社 | Carbon short fiber unwoven fabric and composite body |
| JP2017128705A (en) * | 2016-01-22 | 2017-07-27 | 阿波製紙株式会社 | Carbon fiber sheet material, prepreg, laminate, molded body and method for manufacturing them |
| JP2017133131A (en) * | 2016-01-29 | 2017-08-03 | 三菱製紙株式会社 | Recycled carbon short fiber nonwoven fabric, and composite body |
-
2017
- 2017-08-04 JP JP2017151744A patent/JP6976767B2/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10292254A (en) * | 1997-04-10 | 1998-11-04 | Oji Paper Co Ltd | Wet nonwoven fabric for frp |
| JP2004323992A (en) * | 2003-04-22 | 2004-11-18 | Oji Paper Co Ltd | Nonwoven fabric by wet method and method for producing the same |
| JP2004353124A (en) * | 2003-05-29 | 2004-12-16 | Mitsubishi Paper Mills Ltd | Nonwoven fabric of carbon fiber and method for producing the same |
| JP3152748U (en) * | 2009-05-31 | 2009-08-13 | エアテクス株式会社 | Carbon nonwoven fabric |
| JP2017106130A (en) * | 2015-12-08 | 2017-06-15 | 三菱製紙株式会社 | Carbon short fiber unwoven fabric and composite body |
| JP2017128705A (en) * | 2016-01-22 | 2017-07-27 | 阿波製紙株式会社 | Carbon fiber sheet material, prepreg, laminate, molded body and method for manufacturing them |
| JP2017133131A (en) * | 2016-01-29 | 2017-08-03 | 三菱製紙株式会社 | Recycled carbon short fiber nonwoven fabric, and composite body |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2021183743A (en) * | 2020-05-22 | 2021-12-02 | 三菱製紙株式会社 | Carbon fiber-contained wet-type non-woven fabric |
| JP7282056B2 (en) | 2020-05-22 | 2023-05-26 | 三菱製紙株式会社 | Wet laid nonwoven fabric containing carbon fiber |
| JP7564415B2 (en) | 2020-06-09 | 2024-10-09 | オリベスト株式会社 | Manufacturing method of high density carbon fiber nonwoven fabric |
| JP2022070291A (en) * | 2020-10-27 | 2022-05-13 | 三菱製紙株式会社 | Carbon fiber-containing wet type unwoven fabric |
| JP7386776B2 (en) | 2020-10-27 | 2023-11-27 | 三菱製紙株式会社 | Carbon fiber-containing wet-laid nonwoven fabric |
| WO2022265099A1 (en) * | 2021-06-18 | 2022-12-22 | 三菱ケミカル株式会社 | Self-assembled carbon fiber bundles, method for producing same, prepreg and method for producing same |
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