JPH0424209B2 - - Google Patents

Description

【発明の詳細な説明】[Detailed description of the invention]

本発明は、樹脂を含浸した、あるいは未含浸の
繊維束より、目開のない高品質の一方向引揃え繊
維強化プリプレグを連続的に製造する方法に係わ
る。 現在、炭素繊維、ガラス繊維、全芳香族ポリア
ミド繊維等の補強用繊維束テープにエポキシ樹
脂、不飽和ポリエステル樹脂等を始めとする熱硬
化性樹脂を含浸せしめたプリプレグ板バネやハニ
カム構造材等の工業材料、あるいは釣竿、ゴルフ
シヤフト、バドミントンシヤフト等のスポーツレ
ジヤー用器材の材料として、さらに航空機用、自
動車用、医療用素材として広く使用されている。
今日の様にプリプレグが一般的な中間素材として
定着してきたひとつの理由として、プリプレグ品
質の向上が挙げられる。プリプレグの品質の最も
重要な特性のひとつに外観、特に目開きの有無が
挙げられる。プリプレグに目開きが存在するとそ
のプリプレグで成形した成形体は目開き部分が樹
脂リツチとなり欠陥となつてしまう。目開きを含
む成形体は含まない成形体に比べ強度が場合によ
つて70％あるいはそれ以下に低下してしう。又、
釣竿、ゴルフシヤフト等は機械的性質の低下のみ
ならず、成形体の外観をそこない、商品価値を皆
無にしてしまう欠点となることもあり得る。 本発明者らは、上記問題点を解決すべく種々検
討の結果、繊維束の拡幅をプリプレグに使用する
マトリツクス樹脂を潤滑剤として利用し繊維束の
損傷無く薄くて目開きのない高品質のプリプレグ
が得られることを見出し、本発明に到達したもの
である。 即ち本発明の要旨とするところは、離型紙に載
せた樹脂を含浸させた一方向引揃え繊維束又は樹
脂を塗布させた離型紙上に載せた一方向引揃え繊
維束を曲面を有する基材上を張力下で通過させる
ことにより該繊維束を拡幅し目開きのない一方向
引揃え繊維強化プリプレグを連続的に製造するこ
とにある。 本発明法を以下詳細に述べる。繊維束の拡幅法
のひとつは前工程あるいは製造工程中で先づ一方
向引揃え繊維束に樹脂含浸を施した後、離型紙上
に載せ、曲面を有する基材上を張力下で通過させ
ることで繊維束を押し拡げ均一で目開きの無いプ
リプレグを製造する方法である。もうひとつは、
離型紙上に塗布された樹脂フイルムを用いたホツ
トメルト式に限定したプリプレグ製造法に係わ
り、具体的には、一方向に引揃えた繊維束を離型
紙の樹脂フイルム面に載せ曲面を有する基材上を
張力下に通過させることで、該樹脂フイルムを潤
滑剤的に利用することで繊維束を押し拡げ、しか
る後、加熱ニツプロール等で樹脂含浸を行なつて
プリプレグを製造する方法である。 種々検討の結果いずれの方法においても繊維束
の押し拡げを効果的に達成するには次の３つの条
件を適当に選択しなければならない。 先ず第１に、離型紙上に載つた繊維束が曲面基
材上を通過する時の温度条件である。すなわち温
度が低く過ぎると樹脂粘度が高いため繊維の動き
を固定してしまい繊維束は全く拡がらないし、又
逆に温度が高過ぎて樹脂粘度が下り過ぎると樹脂
のみが流動し繊維束の拡幅効果が軽減されると同
時に基材曲面を通過した後、基材上では拡がつて
いた繊維束が樹脂の表面張力によつて収集し、製
造されるプリプレグに目開きが発生する。樹脂に
も依存するが40〜150℃、好ましくは60〜120℃、
より好ましくは70〜100℃に予熱ヒーターで予熱
するのが好ましい。 第２に曲面の曲率半径の大小が繊維束の押拡げ
効果を大きく左右する。 第１図、第２図に本発明の原理を説明するため
の模式図を示す。ここで第１図は予じめ樹脂が繊
維束に含浸されている場合を、又、第２図は離型
紙に塗布された樹脂フイルム上に繊維束が載せら
れた場合を示す。図中１は繊維束を、２は離型紙
を、３は曲面基材を、４は単繊維を、５は第１図
中では含浸樹脂を、又第２図中では樹脂フイルム
をそれぞれ示す。又、第１図、第２図中ともＡは
側面的、Ｂは横断面的に見た図を示す。さらにＲ
及び△Ｒはそれぞれ曲面上での繊維束底面の曲率
半径及び繊維束の厚みを示す。 曲面上を走行する繊維束内で繊維束を構成する
各単繊維間の走行方向へのズレがないものとすれ
ば１番外側を走る単繊維は底面の単繊維に比べ過
剰な張力△Ｔ＝Ef・△Ｒ／Ｒを受ける。ここでEfは 繊維の引張り弾性率を表す。この△Ｔによつて最
外の単繊維は曲率半径の中心に向うＰなる力を受
ける。 このような力は何も最外の単繊維だけでなく内
側ほど弱くなるが同様の力が他の単繊維にも働き
結果としてP′なる繊維束を走行方向に対し直角に
押し拡げる力が働く。 したがつて基材曲面の曲率半径Ｒが小さければ
小さいほど繊維束の押し拡げ効果は大きくなる。
但しあまり小さ過ぎると、曲面の材質にもよる
が、離型紙を損傷することになるので適当なＲの
基材を選択する必要がある。従つて曲率半径は
0.4〜30mm、好ましくは２〜18mm、より好ましく
は２〜16mmである。 第３の繊維束の押し拡げ効果を左右する大きい
要因は、走行物に掛けられる張力Ｔである。繊維
束はＴ／Ｒなる力で基材曲面の曲率半径方向へ押し 付けられるため張力Ｔが大きればより繊維束を押
し拡げる効果が増大する。一方この張力が弱いと
基材曲面上で走行物が曲面に密着せず繊維束の押
し拡げ効果が減少すると同時に、繊維束内の各繊
維のわずかなゆるみ、蛇行等が解消されないため
前述の張力△Ｔの発生も弱められる。 しかしながらこの張力があまり強過ぎると基材
面との摩擦で離型紙を損傷する恐れがあるので適
当な所で選択する必要がある。幅50cm当り100〜
200Kg、好ましくは140〜180Kg即ち２〜４Kg／cm、
好ましくは2.8〜3.6Kg／cmの張力を付与するのが
好ましい。 以上述べてきた３つの条件を適当に選べば繊維
束、離型紙とも損傷することなく目開きの無い薄
くて均一なプリプレグを得ることが出来るのであ
る。 次に、本発明によるプリプレグ製造方法の実施
例を示す。 実施例 １ 表１に炭素繊維（1200本）64本を引揃え、溶液
含浸タイプのプリプレグ製造装置にて離型紙幅
550mm、プリプレグ幅500mmのエポキシ系マトリツ
クス樹脂プリプレグテープを全張力約170Kg（＝
3.4Kg／cm）で製造した時のプリプレグの外観、
目付、繊維目付等を示す。 表中、Ａ、Ｂ、Ｃ、Ｄ、Ｅは予熱ヒーター温
度、曲面曲率半径を種々変えた場合を示す。 第１図中１は引揃え繊維束、２はフイードロー
ル、３はコーム、４は樹脂含浸用のパダー、５は
溶剤乾燥器、６は離型紙、７は長さ600ｍの予熱
ヒーター、８は曲面基材、９はロール保護用の離
型紙、１０はトランクシヨンロール、１１は巻き
取りリールを各示す。 The present invention relates to a method for continuously producing a high-quality, unidirectionally aligned fiber reinforced prepreg with no openings from fiber bundles impregnated with a resin or not impregnated with a resin. Currently, prepreg leaf springs and honeycomb structural materials are being manufactured by impregnating reinforcing fiber bundle tapes such as carbon fibers, glass fibers, and fully aromatic polyamide fibers with thermosetting resins such as epoxy resins and unsaturated polyester resins. It is widely used as an industrial material or as a material for sports leisure equipment such as fishing rods, golf shafts, badminton shafts, etc., and as a material for aircraft, automobiles, and medical applications.
One of the reasons why prepreg has become so established as a common intermediate material today is the improvement in prepreg quality. One of the most important characteristics of prepreg quality is its appearance, especially the presence or absence of openings. If openings exist in the prepreg, a molded article made from the prepreg will become resin-rich in the openings, resulting in defects. The strength of molded bodies containing openings is reduced by 70% or less in some cases compared to molded bodies without openings. or,
Fishing rods, golf shafts, etc. not only deteriorate the mechanical properties, but also spoil the appearance of the molded product, which can be a drawback that completely eliminates its commercial value. As a result of various studies to solve the above-mentioned problems, the inventors of the present invention have found that by expanding the width of fiber bundles and using the matrix resin used in prepregs as a lubricant, a thin and open high-quality prepreg without damaging the fiber bundles can be produced. The present invention was achieved based on the discovery that the following can be obtained. That is, the gist of the present invention is to prepare a unidirectionally aligned fiber bundle impregnated with a resin placed on a release paper or a unidirectionally aligned fiber bundle placed on a release paper coated with a resin with a curved surface. The purpose is to widen the fiber bundle by passing the fiber bundle under tension to continuously produce a unidirectionally aligned fiber-reinforced prepreg without openings. The method of the present invention will be described in detail below. One method for widening fiber bundles is to first impregnate a unidirectionally aligned fiber bundle with resin during the pre-process or manufacturing process, then place it on release paper and pass it under tension over a base material with a curved surface. In this method, fiber bundles are pressed and expanded to produce uniform prepreg with no openings. The other thing is
The prepreg manufacturing method is limited to the hot melt method using a resin film coated on a release paper, and specifically, fiber bundles aligned in one direction are placed on the resin film surface of the release paper to produce a base material with a curved surface. In this method, the resin film is used as a lubricant to spread the fiber bundle by passing it under tension, and then impregnated with resin using a heated nip roll or the like to produce a prepreg. As a result of various studies, the following three conditions must be appropriately selected in order to effectively expand the fiber bundle in any method. First, there are the temperature conditions when the fiber bundle placed on the release paper passes over the curved base material. In other words, if the temperature is too low, the resin viscosity is high, which fixes the movement of the fibers and the fiber bundle will not expand at all.On the other hand, if the temperature is too high and the resin viscosity drops too much, only the resin will flow, causing the fiber bundle to widen. At the same time as the effect is reduced, after passing through the curved surface of the base material, the fiber bundles spread out on the base material are collected by the surface tension of the resin, and openings occur in the manufactured prepreg. Depending on the resin, the temperature is 40-150℃, preferably 60-120℃,
More preferably, it is preheated to 70 to 100°C using a preheating heater. Secondly, the radius of curvature of the curved surface greatly influences the effect of expanding the fiber bundle. FIGS. 1 and 2 are schematic diagrams for explaining the principle of the present invention. Here, FIG. 1 shows a case where the fiber bundle is impregnated with resin in advance, and FIG. 2 shows a case where the fiber bundle is placed on a resin film coated on release paper. In the figure, 1 indicates a fiber bundle, 2 a release paper, 3 a curved substrate, 4 a single fiber, 5 an impregnated resin in FIG. 1, and a resin film in FIG. 2, respectively. Further, in both FIGS. 1 and 2, A shows a side view, and B shows a cross-sectional view. Further R
and ΔR indicate the radius of curvature of the bottom surface of the fiber bundle on the curved surface and the thickness of the fiber bundle, respectively. Assuming that there is no deviation in the running direction between the single fibers that make up the fiber bundle in a fiber bundle running on a curved surface, the single fiber running on the outermost side will have an excessive tension △T= compared to the single fiber on the bottom surface. Receive Ef・△R/R. Here, Ef represents the tensile modulus of the fiber. Due to this ΔT, the outermost single fiber receives a force P toward the center of the radius of curvature. This kind of force is not limited to the outermost single fibers, but becomes weaker towards the inside, but the same force acts on other single fibers, resulting in a force that pushes and spreads the fiber bundle P' at right angles to the running direction. . Therefore, the smaller the radius of curvature R of the curved surface of the base material, the greater the effect of pushing and spreading the fiber bundle.
However, if the radius is too small, the release paper may be damaged, depending on the material of the curved surface, so it is necessary to select a base material with an appropriate radius. Therefore, the radius of curvature is
It is 0.4 to 30 mm, preferably 2 to 18 mm, more preferably 2 to 16 mm. A major factor that influences the spreading effect of the third fiber bundle is the tension T applied to the running object. Since the fiber bundle is pressed in the direction of the radius of curvature of the curved surface of the base material by the force T/R, the larger the tension T, the greater the effect of pushing and spreading the fiber bundle. On the other hand, if this tension is weak, the running object will not adhere tightly to the curved surface of the base material, reducing the effect of pushing and spreading the fiber bundle, and at the same time, the slight loosening, meandering, etc. of each fiber within the fiber bundle will not be eliminated, so the above-mentioned tension The occurrence of ΔT is also weakened. However, if this tension is too strong, there is a risk of damaging the release paper due to friction with the base material surface, so it is necessary to select an appropriate tension. 100~ per 50cm width
200Kg, preferably 140-180Kg or 2-4Kg/cm,
It is preferable to apply a tension of 2.8 to 3.6 kg/cm. By appropriately selecting the three conditions described above, it is possible to obtain a thin and uniform prepreg with no openings without damaging either the fiber bundle or the release paper. Next, an example of the prepreg manufacturing method according to the present invention will be shown. Example 1 64 carbon fibers (1200 fibers) were arranged as shown in Table 1, and the release paper width was
Epoxy matrix resin prepreg tape with a width of 550 mm and a prepreg width of 500 mm is applied at a total tension of approximately 170 kg (=
Appearance of prepreg when manufactured at 3.4Kg/cm)
Indicates the basis weight, fiber basis weight, etc. In the table, A, B, C, D, and E indicate cases where the preheating heater temperature and the radius of curvature of the curved surface were variously changed. In Figure 1, 1 is a aligned fiber bundle, 2 is a feed roll, 3 is a comb, 4 is a padder for resin impregnation, 5 is a solvent dryer, 6 is release paper, 7 is a preheating heater with a length of 600 m, and 8 is a curved surface A base material, 9 a release paper for roll protection, 10 a trunk roll, and 11 a take-up reel.

【表】 表１から明らかなように、Ａ、Ｅの条件で目開
きのないプリプレグを得ることが出来たが、Ｂ、
Ｃ条件では予熱温度が不適、又Ｄ条件では基材曲
率半径が大き過ぎるため繊維束が拡がらず目開き
が発生した。Ｅ条件では基材曲率半径が小さ過ぎ
るため離型紙裏面が損傷し紙粉が発生した。 実施例 ２ 表２に炭素繊維（3000本）124本を引揃え、第
２図の如きホツトメルトタイプのプリプレグ製造
装置にてエポキシ系樹脂を520mm幅で中央に塗布
した幅550mmの離型紙を用い、500mm幅のプリプレ
グテープを全巾張力約150Kg（＝３Kg／cm）で製
造した時のプリプレグの外観、目付、繊維目等付
等を示す。 第２図中６は樹脂を塗布した離型紙を、１２は
含浸用加熱ニツプロールを、他は第１図の同番号
相当の装置、器材、原料を示す。[Table] As is clear from Table 1, prepregs with no openings could be obtained under conditions A and E, but
In condition C, the preheating temperature was inappropriate, and in condition D, the radius of curvature of the base material was too large, so the fiber bundle did not expand and openings occurred. In condition E, the radius of curvature of the base material was too small, so the back surface of the release paper was damaged and paper dust was generated. Example 2 124 carbon fibers (3000 fibers) were arranged as shown in Table 2, and a 550 mm wide release paper coated with epoxy resin at the center in a 520 mm width was used in a hot melt type prepreg manufacturing device as shown in Figure 2. , shows the appearance, basis weight, fiber grain, etc. of prepreg when a 500mm wide prepreg tape is manufactured with a full width tension of approximately 150Kg (=3Kg/cm). In FIG. 2, reference numeral 6 indicates a release paper coated with resin, 12 indicates a heated nip roll for impregnation, and the other devices, equipment, and raw materials correspond to the same numbers in FIG. 1.

【表】 表２から明らかなように、条件Ａでは外観良好
な極薄プリプレグが得られた。実施例１の場合は
予熱ヒーター温度が80℃付近で最も繊維束の拡幅
が達成されたが、本例では60℃付近が最適温度と
なつている。実施例１、２とも同組成のエポキシ
樹脂であることが実施例１の如く予じめ含浸した
繊維束を押し拡げる場合と、本例の如く樹脂フイ
ルム上の繊維束を押し拡げる場合とで、予熱ヒー
ターの最適温度が多少異なるものと推定される。[Table] As is clear from Table 2, under condition A, an ultra-thin prepreg with a good appearance was obtained. In the case of Example 1, widening of the fiber bundle was achieved most when the preheating heater temperature was around 80°C, but in this example, the optimum temperature was around 60°C. In Examples 1 and 2, the epoxy resins had the same composition in both the case of pushing and spreading a pre-impregnated fiber bundle as in Example 1 and the case of pushing and spreading a fiber bundle on a resin film as in this example. It is assumed that the optimum temperature of the preheating heater is slightly different.

【図面の簡単な説明】[Brief explanation of drawings]

第１図、第２図は本発明の原理を説明するため
の模式図、第３図、第４図は本発明を実施するの
に好適な製造工程の一例を各示すものである。 FIGS. 1 and 2 are schematic diagrams for explaining the principle of the present invention, and FIGS. 3 and 4 each show an example of a manufacturing process suitable for carrying out the present invention.

Claims (1)

【特許請求の範囲】 １ 離型紙に載せた樹脂を含浸させた一方向引揃
え繊維束又は樹脂を塗布させた離型紙上に載せた
一方向引揃え繊維束を、曲面を有する基材上を張
力下で通過させることにより該繊維束を拡幅し目
開きのない一方向引揃え繊維強化プリプレグを連
続的に製造するプリプレグの製法。 ２ 曲面を有する基材の曲率半径が0.4〜30mmで
ある特許請求の範囲第１項記載のプリプレグの製
法。 ３ 繊維束を、曲面を有する基材上を張力下で通
過させるに先立つて40〜150℃の予熱ヒーター上
を通過させることを特徴とする特許請求の範囲第
１項記載のプリプレグの製法。 ４ 幅１cm当り２〜４Kgの張力下で繊維束を通過
させることを特徴とする特許請求の範囲第１項記
載のプリプレグの製法。[Claims] 1. A unidirectionally aligned fiber bundle impregnated with a resin placed on a release paper or a unidirectionally aligned fiber bundle placed on a release paper coated with a resin is placed on a base material having a curved surface. A prepreg manufacturing method in which the fiber bundle is expanded by passing the fiber bundle under tension to continuously produce a unidirectionally aligned fiber-reinforced prepreg without openings. 2. The prepreg manufacturing method according to claim 1, wherein the base material having a curved surface has a radius of curvature of 0.4 to 30 mm. 3. The prepreg manufacturing method according to claim 1, characterized in that the fiber bundle is passed over a preheating heater at 40 to 150°C before being passed under tension over a base material having a curved surface. 4. The prepreg manufacturing method according to claim 1, wherein the fiber bundle is passed under a tension of 2 to 4 kg per 1 cm width.