JP2004074471A

JP2004074471A - Intermediate material for FRP molding and method for producing the same

Info

Publication number: JP2004074471A
Application number: JP2002234861A
Authority: JP
Inventors: Kazuya Goto; 後藤　和也
Original assignee: Mitsubishi Rayon Co Ltd
Current assignee: Mitsubishi Chemical Corp
Priority date: 2002-08-12
Filing date: 2002-08-12
Publication date: 2004-03-11
Anticipated expiration: 2022-08-12
Also published as: JP4116361B2

Abstract

【課題】ラッカー方式で製造されたプリプレグを用いた場合においても、オーブン成形で成形したＦＲＰの表面にはピンホールがなく外観に優れ、内部ボイドもないようなＦＲＰが成形できる、ＦＲＰ成形用中間材料を提供することであり、そのような中間材料を製造する方法を提供する。
【解決手段】熱硬化性樹脂組成物及び補強繊維とからなるプリプレグの少なくとも片面に、熱硬化性樹脂組成物を実質的に含浸していない基材が貼り合わされ、前記プリプレグの厚み（Ａ）と、基材の厚み（Ｂ）との比（Ｂ）／（Ａ）が０．１以上２．５以下であるＦＲＰ成形用中間材料を用いる。
【選択図】　なしAn intermediate for FRP molding, in which even when a prepreg manufactured by a lacquer method is used, an FRP formed by oven molding has no pinholes on its surface, has excellent appearance, and has no internal voids. Providing a material, and a method of producing such an intermediate material.
A substrate not substantially impregnated with a thermosetting resin composition is attached to at least one surface of a prepreg comprising a thermosetting resin composition and a reinforcing fiber, and a thickness (A) of the prepreg is determined. An intermediate material for FRP molding having a ratio (B) / (A) to the thickness (B) of the base material of 0.1 to 2.5 is used.
[Selection diagram] None

Description

【０００１】
【発明の属する技術分野】
本発明は、ＦＲＰ（繊維強化複合材料）を成形するための中間材料及びその製造方法に関する。
【０００２】
【従来の技術】
ＦＲＰは、軽量かつ高強度・高剛性の特徴を生かし、スポーツ・レジャー用途から自動車や航空機等の産業用途まで、幅広く用いられている。特に近年では、補強繊維として炭素繊維を用いた、より軽量でかつより高強度・高剛性のＦＲＰ（ＣＦＲＰ）が産業用途に用いられることが多くなってきた。
【０００３】
産業用途の中でも列車や航空機の機体などの構造部材に用いられるＣＦＲＰは、プリプレグを中間材料として用い、オートクレーブ成形で製造されることが一般的である。これはオートクレーブを用いて高圧下で成形することにより、成形品中のボイドを低減し、成形品の強度を期待された通りに発現させ、又、表面のピンホールの発生を抑え、外観のきれいな成形品を得ることを目的としている。
【０００４】
しかしながら、オートクレーブの設備は非常に高価なため、新規に導入することは困難であるばかりでなく、一旦導入するとそのオートクレーブの大きさにより成形品の大きさが制限され、それより大きな成形品の一体成形は事実上不可能である。
【０００５】
このような問題に対し、オートクレーブを用いずに低コスト成形で成形する方法の開発が盛んに行われており、その代表的なものとしては、真空及び大気圧のみの低圧下で成形する、オーブン成形（又は真空バグ成形などとも呼ばれる。）がある。オーブン成形は真空又は大気圧以外に圧力を加えないので、オートクレーブのようなしっかりした耐圧力容器でなくても良く、温度さえ上げることができる炉（オーブン）があれば成形でき、断熱ボードと熱風ヒーターといった簡便な設備でも成形可能である。ただし圧力を加えないので、成形品中にボイドが残りやすく、成形品はオートクレーブでの成形品に比べて強度が低くなる、あるいは表面にピンホールが発生するという問題があった。
【０００６】
このような問題に対しても近年解決策が講じられつつある。例えばＷＯ　００／２７６３２には樹脂層と補強繊維層からなる材料に関する技術について開示されており、オーブン成形でもボイドの生成が少なく、表面もピンホールが無い非常にきれいな成形品が得られることが記載されている。
ところで、プリプレグの製造方法には、マトリックス樹脂に溶剤を含ませず、加熱して粘度を下げることにより補強繊維に含浸させるホットメルト方式と、溶剤で希釈されたマトリックス樹脂を補強繊維に含浸後脱溶剤するラッカー方式に大別できる。この両製造方式は、使用するマトリックス樹脂の特性や設備的な対応などにより使い分けされているが、前記の技術は、ホットメルト方式にしか用いることができないという問題点を有する。ラッカー方式で製造されたプリプレグでは前記の技術のような構成をとることは不可能であり、ラッカー方式のプリプレグを用いたオーブン成形は非常に困難なものとなっていた。
【０００７】
【発明が解決しようとする課題】
従って本発明の課題は、特にラッカー方式で製造されたプリプレグを用いた場合においても、オーブン成形で成形したＦＲＰの表面にはピンホールがなく外観に優れ、内部ボイドもないようなＦＲＰが成形できる、ＦＲＰ成形用中間材料を提供することであり、そのようなＦＲＰ成形用中間材料を製造する方法を提供することである。
【０００８】
【課題を解決するための手段】
本発明は以下の構成よりなる。すなわち本発明第一の要旨は、熱硬化性樹脂組成物及び補強繊維とからなるプリプレグの少なくとも片面に、熱硬化性樹脂組成物を実質的に含浸していない基材が貼り合わされ、前記プリプレグの厚み（Ａ）と、基材の厚み（Ｂ）との比（Ｂ）／（Ａ）が０．１以上２．５以下であるＦＲＰ成形用中間材料である。前記プリプレグはラッカー方式で製造されたものであるものが好ましく、前記基材は熱可塑性樹脂組成物の繊維状物、熱可塑性樹脂組成物の不織布又は補強繊維を用いることが好ましいが、補強繊維を用いる場合には、プリプレグを構成する補強繊維と同じ素材であっても異なっていても良い。
同じ素材を用いる場合には、基材を構成する補強繊維とプリプレグを構成する補強繊維とが角度をなして貼り合わさっていることも好ましい。プリプレグに用いる熱硬化性樹脂組成物はエポキシ樹脂又はフェノール樹脂のいずれか若しくはその両方を用いることが好ましく、補強繊維としては炭素繊維及び／又はガラス繊維を用いることが好ましい。
【０００９】
本発明の第二の要旨は、ラッカー方式によりプリプレグを調製し、次に、該プリプレグの少なくとも片面に樹脂を含浸していない基材を貼り合わせるＦＲＰ成形用中間材料の製造方法である。本発明の製造方法においては、プリプレグの厚み（Ａ）と、前記基材の厚み（Ｂ）の比（Ｂ）／（Ａ）が０．１以上２．５以下であるのが好ましく、前記ラッカー方式において、溶剤としてアセトンを用いることが好ましい。
【００１０】
【発明の実施の形態】
以下、本発明について詳細に述べる。
（熱硬化性樹脂組成物）
本発明に用いられる熱硬化性樹脂組成物としては特に制限はなく、エポキシ樹脂、フェノール樹脂、ビスマレイミド樹脂、ＢＴ樹脂、シアネートエステル樹脂、ベンゾオキサジン樹脂などが例示できるが、中でもエポキシ樹脂は、補強繊維との接着性に優れるため、得られるＦＲＰの機械特性に優れるために好ましい。又フェノール樹脂は難燃性に優れているばかりでなく、ラッカー方式のプリプレグ調製方法に特に適したマトリックス樹脂であるため、好適に用いることができる。
【００１１】
（補強繊維）
本発明に用いられるプリプレグを構成する補強繊維としては特に制限はなく、その素材としてはガラス繊維、炭素繊維、アラミド繊維、ボロン繊維、ＰＢＯ繊維など、高強度・高弾性である補強繊維すべてが使用可能であるが、中でもガラス繊維や炭素繊維が素材である補強繊維は、弾性率と強度のバランスに優れ、得られるＦＲＰが機械的性能に優れるために好適に用いられる。
【００１２】
（プリプレグの製造方法）
又本発明に用いられるプリプレグの製造方法としては、上述のホットメルト方式でも良いが、ラッカー方式で製造したプリプレグを用いた場合でも、オーブン成形で内部ボイドや表面のピンホールのない成形品が得られるので、特にラッカー方式で製造されたプリプレグを用いると本発明の効果が顕著に得られる。
【００１３】
ラッカー方式とは、既に述べた様に、溶剤で希釈されたマトリックス樹脂溶液を補強繊維に含浸後脱溶剤するプリプレグの製造方法である。溶液を強化繊維に含浸する方法としては、強化繊維をマトリックス樹脂溶液中に浸漬させる、若しくは、ローラーに溶液を付着させてそれを強化繊維に転写させる、等が挙げられるが、強化繊維を溶液中に浸漬させて含浸する方法が、強化繊維へのマトリックス樹脂溶液の含浸性が優れる点で好ましい。又、脱溶剤するには、温風又は熱風乾燥、減圧乾燥する方法等が挙げられるが、温風乾燥を用いることが、生産性の点で好ましい。
【００１４】
（プリプレグと基材）
本発明のＦＲＰ成形用中間材料は、上記プリプレグの少なくとも片面に樹脂を含浸していない基材を貼り合わせてなるものである。この基材が脱気回路としてはたらくことにより、成形中に内部の空気だまりを脱気することが容易となるので、成形品中のボイドや成形品表面のピンホールの発生を防ぐ役割を果たす。基材をプリプレグの両面に貼ると脱気回路が片面のみに貼るよりも大きくなるので好ましい場合もあるが、両面にタックがなくなってしまうので作業性に劣るケースがありうるため、基材は片面のみに貼り付け、もう一方の面はプリプレグのままとし、タックを維持した状態である方が好ましい場合が多い。
【００１５】
本発明のＦＲＰ成形用中間材料は、上述のように基材が成形中に脱気回路として働き、成形物中のエアを成形物の外に導き出す経路となる。しかし一方で、成形後は補強繊維に含浸させた熱硬化性樹脂組成物が成形中に基材にも含浸して一体化し、ボイドやピンホールのない成形物が得られなければならない。よって、基材は脱気回路として十分な空隙量を有しつつその空隙を成形中に熱硬化性樹脂が完全に含浸し得る空隙量でなければならない。従って、本発明において用いるプリプレグに対応した基材の空隙量とすることがポイントとなるが、検討の結果、プリプレグと基材との厚みの比を制御することにより好ましい空隙量となることがわかった。具体的には、プリプレグの厚み（Ａ）と基材の厚み（Ｂ）の比（Ｂ）／（Ａ）が０．１以上、２．５以下である必要がある。上述のように、基材は脱気回路として十分な空隙を有し、かつその空隙は成形中に樹脂が完全に含浸し得る大きさでなければならない。従って本発明において下限値が０．１５以上であるときは更に好ましく、０．２以上である場合には特に好ましい。しかし。
０．１未満のときは脱気回路として十分な空隙が基材内に確保できずに成形後に空気が残ることがある。又、上限値が１．５以下の場合は更に好ましく、１．１以下の場合は特に好ましいが、２．５を大きく超えるときは成形中に完全に樹脂が含浸しきらずに成形後に空気が残る。
【００１６】
（プリプレグ及び基材の厚みの測定）
ここで、プリプレグの厚み（Ａ）、及び基材の厚み（Ｂ）はノギスで測定した値を用いる。ただし、測定時にノギスがプリプレグや基材を押さえつけて厚みが変化しないように注意しなければならない。特に基材について、測定時に押さえつけて厚みの測定誤差が大きくなる懸念のあるときは、基材の断面の写真をとり、拡大して誤差が無いことを確認しながら測定する方法が好ましい。さらに、基材をプリプレグの両面に貼り合わせる場合は、各面に貼り合わせる基材のそれぞれの厚みの和を（Ｂ）とする。
【００１７】
（基材の構成）
基材を構成する素材としては、例えば繊維状熱可塑性樹脂組成物や補強繊維を挙げることができる。熱可塑性樹脂組成物を用いる場合には、本発明のＦＲＰ成形用中間材料を積層したときに層間補強の効果が得られるので好ましい。このような素材の例としては、ナイロン、ポリエステル、ポリエチレン、ポリプロピレン等が例示でき、又この場合素材の形状としては、脱気回路が確保できれば、ネットのようなものでも使用可能であり、ロッドや線材状の熱可塑性材料を一方向に引きそろえたものでもよく、さらにはこれらを角度を変えて積層したようなものでも良い。しかしながら、効率的な脱気回路を確保する上では熱可塑性樹脂組成物が繊維状物よりなるのが最も好ましく、特に繊維状物よりなる織物、一方向材又は不織布などが挙げられ、中でも不織布は脱気回路の形成が容易であるので特に好ましい。
【００１８】
又、この基材の素材として、熱可塑性樹脂組成物でない繊維、特に補強繊維も好適に用いることができる。基材の素材として補強繊維を用いる場合には、上述のプリプレグを構成する補強繊維と同じものでも良いし、異なるものでも良い。
【００１９】
基材の素材として、プリプレグを構成する補強繊維と同じものを用いる場合には、プリプレグを構成する補強繊維の配向角度に対し、基材を構成する補強繊維の配向角度が同じになるように貼り合わせても良いが、両者を異なる配向角度で貼り合わせた場合には、擬似等方積層などの際の積層工程での手間が省けるので好ましい。なお、擬似等方積層とは、［−４５°／０°／４５°／９０°］と積層するように、ＦＲＰの物性に異方性が生じないようにするために各層の配向角度をＦＲＰ全体として等方的に積層することである。
【００２０】
一方、基材を構成する補強繊維にプリプレグを構成する補強繊維とは異なる補強繊維を用いることもできる。この場合は、簡単にハイブリッドのＦＲＰを製造することができるので好適である。例えばプリプレグを構成する補強繊維としてガラス繊維よりなる織物を用い、基材を構成する補強繊維として炭素繊維よりなる織物を用いたＦＲＰ成形用中間材料を用いて製造されたＦＲＰは、ガラス／炭素繊維よりなるハイブリッドなＦＲＰとなり、コストパフォーマンスを最良に設計することができる。尚、この場合も、基材を構成する補強繊維とプリプレグを構成する補強繊維との繊維の配向角度は、同じであっても異なっていても良い。
【００２１】
（ＦＲＰ成形用中間材料の製造方法）
本発明のＦＲＰ成形用中間材料を製造する方法は、前述のラッカー方式を用いてプリプレグを調製し、得られたプリプレグの少なくとも片面に樹脂を含浸していない基材を貼り合わせる製造方法である。
【００２２】
本発明の製造方法において、溶剤としては、通常のラッカー方式のプリプレグを製造する際に用いられる溶剤をいずれも用いることができる。例えば、アセトンやメチルエチルケトン、塩化メチレン、アルコール類、などであるが、乾燥の速さや作業環境の安全性等の点からアセトンを用いることが好ましい。
【００２３】
基材をプリプレグに貼り合わせるときは加熱する必要は特にないが、プリプレグのタックが不足しているような場合には加熱して貼り合わせても構わない。ただしその場合には、プリプレグの保存可能期間等の性能に影響を与えない程度の加熱にとどめるべきである。
【００２４】
【実施例】
以下、実施例で本発明を詳細に説明するが、本発明は以下の実施例に限定されるものではない。尚、実施例１〜４及び６並びに比較例１〜４で用いた熱硬化性樹脂組成物のアセトン溶液は、下記成分からなるエポキシ樹脂組成物（室温で固体）をアセトンに均一に溶解して調製した、エポキシ樹脂組成物が６０質量％のアセトン溶液を用いた（以下、単にエポキシ溶液と呼ぶ）。
【００２５】
（エポキシ樹脂組成物）
エピコート８２８（ジャパンエポキシレジン（株）社製）　５０質量部
エピコート１００４（ジャパンエポキシレジン（株）社製）３０質量部
エピクロンＮ７４０（大日本インキ化学工業（株）社製）　２０質量部
ＤＣＭＵ９９（保土ヶ谷化学社（株）製）　　　　　　　　５質量部
【００２６】
（実施例１）
炭素繊維を経糸及び緯糸に用いた三菱レイヨン社製、炭素繊維織物パイロフィルＴＲＫ５１０（２／２綾織、繊維目付け６４６ｇ／ｍ^２、厚み０．５７ｍｍ）を、エポキシ溶液中に浸漬することにより含浸し、４０℃の温風で乾燥、脱溶剤して、レジンコンテント４６．７質量％（樹脂目付け５６４ｇ／ｍ^２）のプリプレグを得た。このプリプレグの厚みをノギスを用いて測定すると、厚み（Ａ）＝０．８５ｍｍであった。このプリプレグに基材として炭素繊維を経糸及び緯糸に用いた三菱レイヨン社製炭素繊維織物パイロフィルＴＲ３１１０（平織、繊維目付け２００ｇ／ｍ^２、厚み（Ｂ）＝０．２３ｍｍ）を用い、経糸及び緯糸の配向角度がプリプレグと同一方向となるように片面に貼り合わせて、ＦＲＰ成形用中間材料を得た。この中間材料の（Ｂ）／（Ａ）は０．２７、中間材料全体の繊維目付けは８４６ｇ／ｍ^２、レジンコンテントは４０質量％であった。
得られた中間材料のプリプレグ側の面を成形型に貼り付け、同一配向角度で同じ面を同じ向きにして３プライ積層し、５００ｍｍ×５００ｍｍの平板をオーブン成形した。成形条件は次のとおりとした。すなわち、５Ｔｏｒｒ以下の該真空下で室温から５０℃まで昇温速度３℃／分で昇温し、５０℃×３時間保持、その後１２０℃まで０．５℃／分で昇温し、１２０℃×２時間で成形した。
得られたＦＲＰパネルはオーブン成形であるにもかかわらず、表１に示したように、表面にはピンホールが見られず、又、ＦＲＰパネル中央部をカットして内部を観察したが、内部にもボイドは見られなかった。
【００２７】
（実施例２）
レジンコンテントを５７．１質量％（樹脂目付け８６１ｇ／ｍ^２）、厚み（Ａ）＝１．１ｍｍとしたこと以外は、実施例１と同様にしてプリプレグを調製した。得られたプリプレグに、基材としてプリプレグに用いた補強繊維織物と同じ厚み（Ｂ）＝０．５７ｍｍのＴＲＫ５１０を用い、プリプレグの補強繊維の配向方向から４５°傾けて片面に貼り合わせてＦＲＰ成形用中間材料を得た。この中間材料の（Ｂ）／（Ａ）は０．５２、中間材料全体の繊維目付けは１２９２ｇ／ｍ^２、レジンコンテントは４０質量％であった。
得られたＦＲＰ成形用中間材料を経糸の繊維配向角度が［−４５°／０°／４５°／９０°／９０°／４５°／０°／−４５°］となるように積層し、実施例１と同様にしてオーブン成形してＦＲＰパネルを得た。ただし、本実施例における中間材料は０°／４５°の二層構造なので、本中間材料単位では４プライ積層した。
得られたＦＲＰパネルは、表１に示したように、表面にはピンホールが見られず、又ＦＲＰパネル中央部をカットして内部を観察したが、内部にもボイドは見られなかった。
【００２８】
（実施例３）
ＴＲＫ５１０に代えて日東紡社製ロービングガラスクロスＷＲ８００を用い、レジンコンテントを５３．３質量％（樹脂目付けは４５０ｇ／ｍ^２）、厚み（Ａ）＝０．７１ｍｍとした以外は、実施例１と同様にしてのプリプレグを得た。さらに、このプリプレグにパイロフィルＴＲ３１１０を、経糸及び緯糸の配向角度がプリプレグと同一方向となるように、片面に貼り合わせて、ガラス繊維／炭素繊維のハイブリッドＦＲＰ成形用中間材料を得た（（Ｂ）／（Ａ）＝０．３２）。
得られた本発明の中間材料を、同一配向角度で同じ面を同じ向きにして４プライ積層し、実施例１と同様にしてオーブン成形し、ガラス繊維／炭素繊維のハイブリッドＦＲＰを得た。本発明の中間材料を用いればハイブリッドＦＲＰが簡単に成形できた。
又得られたＦＲＰパネルは、表１に示したように、表面にはピンホールが見られず、又ＦＲＰパネル中央部をカットして内部を観察したが、内部にもボイドは見られなかった。
【００２９】
（実施例４）
レジンコンテントを５１．９質量％（樹脂目付け、６９７．５ｇ／ｍ^２）、厚み（Ａ）＝０．９６ｍｍとした以外は、実施例１と同様にプリプレグを調製した。得られたプリプレグに基材としてパイロフィルＴＲ３１１０を経糸及び緯糸の配向角度がプリプレグと同一方向となるように、プリプレグの表裏両面に貼り付け、本発明のＦＲＰ成形用中間材料を得た。この中間材料は、（Ｂ）／（Ａ）＝０．２４、中間材料全体の炭素繊維目付けは１０６４ｇ／ｍ^２、レジンコンテントは４０質量％であった。
得られた本発明の中間材料を、同一配向角度で同じ面を同じ向きに１０プライ積層し、実施例１と同様にしてオーブン成形してＦＲＰパネルを得た。
得られたＦＲＰパネルは、表１に示したように、表面にはピンホールが見られず、又ＦＲＰパネル中央部をカットして内部を観察したが、内部にもボイドは見られなかった。
【００３０】
（実施例５）
エポキシ樹脂に代えて、大日本インキ化学工業社製フェノール樹脂のメタノール溶液、フェノライト５９００（約６０質量％）を用い、レジンコンテントを５７．１質量％（樹脂目付けは８６１ｇ／ｍ^２）、厚み（Ａ）＝１．１ｍｍとした以外は実施例１と同様にしてのプリプレグを調整した。これにパイロフィルＴＲ３１１０を炭素繊維の配向方向が同じ向きになるようにして、片面に貼り合わせてＦＲＰ成形用中間材料を得た。この中間材料の（Ｂ）／（Ａ）は０．２１、中間材料全体の繊維目付けは１２９２ｇ／ｍ^２、レジンコンテントは４０質量％であった。
得られた本発明の中間材料３プライを同じ向きに積層し、１０００ｍｍ×１０００ｍｍのＦＲＰパネルをオーブン成形した。ただし成形条件は５Ｔｏｒｒ以下該真空下で、９０℃まで０．５℃／分で昇温し、９０℃×２０時間とした。
得られたＦＲＰパネルは、表１に示したように表面はピンホールが見られず、又ＦＲＰパネル中央部をカットして内部を観察したが、内部にもボイドは見られなかった。
【００３１】
（比較例１）
プリプレグに基材を貼り付けない場合の例を示す。レジンコンテントを４０．０％（樹脂目付け４３１ｇ／ｍ^２）、厚み（Ａ）＝０．７３ｍｍとした以外は、実施例１と同様にしてプリプレグを調製した。
得られたプリプレグのみを［−４５°／０°／４５°／９０°／９０°／４５°／０°／−４５°］に８プライ積層し、実施例１と同様にしてオーブン成形してＦＲＰパネルを得た。
得られたＦＲＰパネルは、表１に示したように表面にピンホールが多数見られ、又ＦＲＰパネル中央部をカットして内部を観察したところ、内部にもボイドが多数見られた。
【００３２】
（比較例２）
レジンコンテントを４０．５％（樹脂目付け４３０ｇ／ｍ^２）、厚み（Ａ）＝０．７４ｍｍとした以外は、実施例１と同様にしてプリプレグを調製した。このプリプレグに基材としてユニチカグラスファイバー（株）社製ガラスクロスＨ２０Ｆ５　１０４（厚み（Ｂ）＝０．０４ｍｍ）を貼り合わせてＦＲＰ成形用中間材料を得た。この中間材料の（Ｂ）／（Ａ）は０．０５であった。
このＦＲＰ成形用中間材料を実施例１と同様にしてオーブン成形してＦＲＰパネルを得た。得られたＦＲＰパネルは、表１に示したように表面にピンホールが見られ、又ＦＲＰパネル中央部をカットして内部を観察したところ、内部にもボイドが見られた。
【００３３】
（比較例３）
レジンコンテントを３２．０％（樹脂目付け３００ｇ／ｍ^２）、厚み（Ａ）＝０．６２ｍｍとした以外は、実施例１と同様にしてプリプレグを調製した。このプリプレグにポリエステル繊維不織布（繊維目付け１３２ｇ／ｍ^２、厚み（Ｂ）＝１．７ｍｍ）を貼り合わせてＦＲＰ成形用中間材料を得た。このＦＲＰ成形用中間材料の（Ｂ）／（Ａ）は２．７４であった。
このＦＲＰ成形用中間材料を実施例１と同様にしてオーブン成形してＦＲＰパネルを得た。得られたＦＲＰパネルは、表１に示したように表面に樹脂未含浸部が多数見られ、又ＦＲＰパネル中央部をカットして内部を観察したところ、内部にもボイド多数が見られた。
【００３４】
（実施例６）
三菱レイヨン製炭素繊維パイロフィルＴＲ５０Ｓ−１２Ｌを繊維目付け１９０ｇ／ｍ^２で一方向に引き揃え、実施例１と同様にしてレジンコンテント３０．２質量％（樹脂目付け、８２．３ｇ／ｍ^２）、厚み（Ａ）＝０．１８ｍｍのプリプレグを調製した。このプリプレグに厚み（Ｂ）＝０．３２ｍｍのナイロン１２繊維からなる不織布（繊維目付け２０ｇ／ｍ^２）を片面に貼り付けてＦＲＰ成形用中間材料を得た（（Ｂ）／（Ａ）＝１．７８）。
得られたＦＲＰ成形用中間材料を炭素繊維の配向角度が［−４５°／０°／４５°／９０°］_３ｓとなるようにに計２４プライ積層した（３ｓとは積層の繰返し単位を３回繰り返したものを鏡面で対称になるように貼り合わせたことを示す。すなわち、最初の１２プライは炭素繊維側を型側とし、その後の１２プライは炭素繊維側を型と反対側に積層した）。このようにして積層し、実施例１と同様にしてオーブン成形してＦＲＰパネルを得た。
得られたＦＲＰパネルの表面及び層間にはピンホールはみられず、又ＦＲＰパネル中央部をカットして内部を観察したが、内部にもボイドは見られなかった。このパネルのＣＡＩ（衝撃後の残存圧縮強度）測定を行った。ＣＡＩ測定はＳＡＣＭＡのＳＲＭ２−８８法に準拠して実施した。加えた衝撃は１５００インチ・ポンド／インチとした。その結果、得られたパネルのＣＡＩ測定の結果は３５０ＭＰａとＦＲＰとして高い値であった。
【００３５】
（比較例４）
レジンコンテントは３５．０％（樹脂目付け１０２．３ｇ／ｍ^２）、厚み（Ａ）＝０．１９ｍｍとした以外は、実施例６と同様にしてプリプレグを調製した。得られたプリプレグのみを［−４５°／０°／４５°／９０°］_３ｓとなるように計２４プライ積層し、実施例１と同様にオーブン成形してＦＲＰを成形した。
得られたＦＲＰパネルは、表面、層間に若干のボイドがみられ、又ＦＲＰパネル中央部をカットして内部を観察したが、内部にもボイドが見られた。又、得られたパネルのＣＡＩ測定を行ったところ、２１０ＭＰａと低かった。
【００３６】
【表１】

【００３７】
【発明の効果】
以上説明したように、本発明のＦＲＰ成形用中間材料は、熱硬化性樹脂組成物及び補強繊維とからなるプリプレグの少なくとも片面に、熱硬化性樹脂組成物を実質的に含浸していない基材が貼り合わされ、前記プリプレグの厚み（Ａ）と、基材の厚み（Ｂ）との比（Ｂ）／（Ａ）が０．１以上２．５以下であるＦＲＰ成形用中間材料であるので、ラッカー方式で製造された場合でも、オーブン成形で成形したＦＲＰの表面にはピンホールがなく外観に優れ、内部ボイドも見られ無いＦＲＰが成形可能なＦＲＰ成形用中間材料を提供することができる。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an intermediate material for molding FRP (fiber reinforced composite material) and a method for producing the same.
[0002]
[Prior art]
FRP has been widely used in sports and leisure applications, as well as in industrial applications such as automobiles and aircraft, taking advantage of its features of light weight, high strength and high rigidity. In particular, in recent years, lighter, higher-strength, and higher-rigidity FRPs (CFRPs) using carbon fibers as reinforcing fibers have been increasingly used for industrial applications.
[0003]
Among industrial uses, CFRP used for structural members such as trains and aircraft bodies is generally manufactured by autoclave molding using a prepreg as an intermediate material. This is achieved by molding under high pressure using an autoclave to reduce voids in the molded product, develop the strength of the molded product as expected, suppress the occurrence of pinholes on the surface, and clean the appearance. The purpose is to obtain molded products.
[0004]
However, since the autoclave equipment is very expensive, it is not only difficult to introduce a new one, but once introduced, the size of the molded product is limited by the size of the autoclave, and the integration of a larger molded product Molding is virtually impossible.
[0005]
In order to solve such problems, development of a method of molding at low cost without using an autoclave has been actively performed, and a typical example thereof is an oven for molding under a low pressure of only vacuum and atmospheric pressure. Molding (or also called vacuum bag molding). Oven molding does not apply any pressure other than vacuum or atmospheric pressure, so it does not need to be a firm pressure-resistant container such as an autoclave. If there is a furnace (oven) that can raise the temperature, it can be molded, insulation board and hot air Molding is possible with simple equipment such as a heater. However, since no pressure is applied, voids tend to remain in the molded product, and the molded product has a problem in that the strength is lower than that of the molded product in an autoclave, or a pinhole is generated on the surface.
[0006]
In recent years, solutions to these problems have been taken. For example, WO 00/27632 discloses a technology relating to a material composed of a resin layer and a reinforcing fiber layer, and describes that even in oven molding, there is little generation of voids, and a very clean molded product having no pinholes on the surface can be obtained. Have been.
By the way, the prepreg production method includes a hot melt method in which the matrix resin is impregnated into the reinforcing fibers by reducing the viscosity by heating without containing a solvent, or a method in which the matrix fibers diluted with the solvent are impregnated into the reinforcing fibers and then removed. It can be roughly divided into lacquer systems that use solvents. These two production methods are properly used depending on the characteristics of the matrix resin to be used and the facility, but there is a problem that the above-mentioned technique can be used only for the hot melt method. The prepreg manufactured by the lacquer method cannot be configured as described above, and it is very difficult to form an oven using the lacquer prepreg.
[0007]
[Problems to be solved by the invention]
Therefore, an object of the present invention is to provide an FRP that has no pinholes on the surface of an FRP formed by oven forming and has excellent appearance and no internal voids, even when a prepreg manufactured by a lacquer method is used. , An intermediate material for FRP molding, and a method for producing such an intermediate material for FRP molding.
[0008]
[Means for Solving the Problems]
The present invention has the following configurations. That is, the first gist of the present invention is that at least one side of a prepreg comprising a thermosetting resin composition and a reinforcing fiber, a substrate substantially not impregnated with the thermosetting resin composition is attached to the prepreg, This is an intermediate material for FRP molding wherein the ratio (B) / (A) of the thickness (A) to the thickness (B) of the substrate is 0.1 or more and 2.5 or less. The prepreg is preferably manufactured by a lacquer method, and the base material is preferably a fibrous material of a thermoplastic resin composition, a nonwoven fabric or a reinforcing fiber of a thermoplastic resin composition, but the reinforcing fiber is preferably used. When used, the material may be the same as or different from the reinforcing fibers constituting the prepreg.
When the same material is used, it is also preferable that the reinforcing fibers forming the base material and the reinforcing fibers forming the prepreg are bonded at an angle. As the thermosetting resin composition used for the prepreg, it is preferable to use one or both of an epoxy resin and a phenol resin, and it is preferable to use carbon fibers and / or glass fibers as the reinforcing fibers.
[0009]
The second gist of the present invention is a method for producing an intermediate material for FRP molding, in which a prepreg is prepared by a lacquer method, and then a substrate not impregnated with a resin is bonded to at least one surface of the prepreg. In the production method of the present invention, the ratio (B) / (A) of the thickness (A) of the prepreg to the thickness (B) of the base material is preferably 0.1 or more and 2.5 or less, and the lacquer is preferably used. In the method, it is preferable to use acetone as a solvent.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail.
(Thermosetting resin composition)
The thermosetting resin composition used in the present invention is not particularly limited, and examples thereof include an epoxy resin, a phenol resin, a bismaleimide resin, a BT resin, a cyanate ester resin, and a benzoxazine resin. It is preferable because it has excellent adhesiveness to fibers and has excellent mechanical properties of the obtained FRP. In addition, phenol resin is not only excellent in flame retardancy, but is also a matrix resin particularly suitable for a lacquer-type prepreg preparation method, and thus can be suitably used.
[0011]
(Reinforcing fiber)
The reinforcing fiber constituting the prepreg used in the present invention is not particularly limited, and all the reinforcing fibers having high strength and high elasticity such as glass fiber, carbon fiber, aramid fiber, boron fiber and PBO fiber are used as the material. Although it is possible, a reinforcing fiber made of glass fiber or carbon fiber is preferably used because it has an excellent balance between elastic modulus and strength and the obtained FRP has excellent mechanical performance.
[0012]
(Prepreg manufacturing method)
As a method for producing a prepreg used in the present invention, the above-described hot melt method may be used.However, even when a prepreg produced by a lacquer method is used, a molded article without internal voids or pinholes on the surface can be obtained by oven molding. Therefore, the effect of the present invention can be remarkably obtained particularly when a prepreg manufactured by a lacquer method is used.
[0013]
As described above, the lacquer method is a method for producing a prepreg in which a reinforcing fiber is impregnated with a matrix resin solution diluted with a solvent and then the solvent is removed. Examples of a method of impregnating the solution with the reinforcing fibers include immersing the reinforcing fibers in a matrix resin solution, or attaching a solution to a roller and transferring the solution to the reinforcing fibers. The method of impregnating by impregnating the reinforcing fiber with a matrix resin solution is preferable because the impregnating property of the matrix resin solution into the reinforcing fibers is excellent. In order to remove the solvent, a method of drying with hot air or hot air, drying under reduced pressure, or the like can be used. However, it is preferable to use hot air drying in terms of productivity.
[0014]
(Prepreg and substrate)
The intermediate material for FRP molding of the present invention is obtained by laminating a base material not impregnated with a resin on at least one surface of the prepreg. Since this substrate functions as a degassing circuit, it becomes easy to degas the internal air pool during molding, and thus plays a role in preventing the occurrence of voids in the molded product and pinholes on the surface of the molded product. Adhering the base material to both sides of the prepreg may be preferable because the deaeration circuit is larger than sticking to only one side, but there are cases where it is inferior in workability because tack is lost on both sides, so the base material is one side In many cases, it is preferable to stick the prepreg on the other side and leave the other side as a prepreg to maintain the tack.
[0015]
The intermediate material for FRP molding of the present invention, as described above, acts as a degassing circuit during molding of the base material, and serves as a path for leading air in the molded product out of the molded product. However, on the other hand, after molding, the thermosetting resin composition impregnated into the reinforcing fibers must also be impregnated into the base material during molding to be integrated, and a molded article without voids and pinholes must be obtained. Therefore, the base material must have a sufficient void amount as a degassing circuit and a void amount that can be completely impregnated with the thermosetting resin during the molding of the void. Therefore, it is important to set the gap amount of the base material corresponding to the prepreg used in the present invention, but as a result of examination, it is found that the preferable gap amount is obtained by controlling the ratio of the thickness of the prepreg to the base material. Was. Specifically, the ratio (B) / (A) of the thickness (A) of the prepreg to the thickness (B) of the base material needs to be 0.1 or more and 2.5 or less. As mentioned above, the substrate must have sufficient voids as a degassing circuit, and the voids must be large enough to completely impregnate the resin during molding. Accordingly, in the present invention, the lower limit is more preferably 0.15 or more, and particularly preferably 0.2 or more. However.
If it is less than 0.1, a sufficient space for the deaeration circuit cannot be secured in the base material, and air may remain after molding. Further, when the upper limit value is 1.5 or less, it is more preferable, and when it is 1.1 or less, it is particularly preferable. When the upper limit value greatly exceeds 2.5, air is left after molding without completely impregnating the resin during molding. .
[0016]
(Measurement of thickness of prepreg and substrate)
Here, the thickness (A) of the prepreg and the thickness (B) of the base material use values measured with a caliper. However, care must be taken during measurement to prevent the caliper from pressing down on the prepreg or the base material so that the thickness does not change. In particular, when there is a concern that the measurement error of the thickness is increased by pressing the base material during measurement, a method of taking a photograph of a cross section of the base material and enlarging the measurement while confirming that there is no error is preferable. Further, when the base material is bonded to both surfaces of the prepreg, the sum of the thicknesses of the base materials bonded to each surface is defined as (B).
[0017]
(Configuration of base material)
Examples of the material constituting the substrate include a fibrous thermoplastic resin composition and reinforcing fibers. The use of a thermoplastic resin composition is preferred because the effect of interlayer reinforcement can be obtained when the intermediate material for FRP molding of the present invention is laminated. Examples of such a material include nylon, polyester, polyethylene, polypropylene, and the like.In this case, as a shape of the material, a net-like material can be used as long as a degassing circuit can be secured. A thermoplastic material in the form of a wire may be arranged in one direction, or may be formed by laminating them at different angles. However, in order to ensure an efficient degassing circuit, it is most preferable that the thermoplastic resin composition is made of a fibrous material, and in particular, a woven fabric, a unidirectional material or a nonwoven fabric made of a fibrous material is included. It is particularly preferable because the formation of a deaeration circuit is easy.
[0018]
Further, as a material of the base material, a fiber which is not a thermoplastic resin composition, in particular, a reinforcing fiber can also be suitably used. When reinforcing fibers are used as the base material, they may be the same as or different from the reinforcing fibers constituting the prepreg.
[0019]
When the same material as the reinforcing fibers constituting the prepreg is used as the material of the base material, the base material is adhered so that the orientation angle of the reinforcing fibers constituting the base material is the same as the orientation angle of the reinforcing fibers constituting the prepreg. Although they may be combined with each other, it is preferable to bond them at different orientation angles, since the labor in the laminating step in the case of quasi-isotropic lamination or the like can be saved. In addition, the pseudo isotropic lamination means that the orientation angle of each layer is set to FRP in order to prevent anisotropy from occurring in the physical properties of FRP so as to laminate with [−45 ° / 0 ° / 45 ° / 90 °]. Lamination isotropically as a whole.
[0020]
On the other hand, a reinforcing fiber different from the reinforcing fibers forming the prepreg can be used as the reinforcing fibers forming the base material. This case is preferable because a hybrid FRP can be easily manufactured. For example, an FRP manufactured using an intermediate material for FRP molding using a woven fabric made of glass fiber as a reinforcing fiber constituting a prepreg and a woven fabric made of carbon fiber as a reinforcing fiber constituting a base material is a glass / carbon fiber. The hybrid FRP can be designed with the best cost performance. Also in this case, the orientation angles of the reinforcing fibers constituting the base material and the reinforcing fibers constituting the prepreg may be the same or different.
[0021]
(Method for producing intermediate material for FRP molding)
The method for producing the intermediate material for FRP molding of the present invention is a production method in which a prepreg is prepared by using the lacquer method described above, and a base material not impregnated with a resin is bonded to at least one surface of the obtained prepreg.
[0022]
In the production method of the present invention, as the solvent, any solvent used when producing a normal lacquer type prepreg can be used. For example, acetone, methyl ethyl ketone, methylene chloride, alcohols and the like are preferred, but acetone is preferably used from the viewpoint of drying speed and safety of the working environment.
[0023]
There is no particular need to heat when the base material is bonded to the prepreg, but if the tack of the prepreg is insufficient, heating may be performed. However, in such a case, heating should be limited to such a degree that does not affect the performance of the prepreg such as the storage period.
[0024]
【Example】
Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the following examples. The acetone solution of the thermosetting resin composition used in Examples 1-4 and 6 and Comparative Examples 1-4 was obtained by uniformly dissolving an epoxy resin composition (solid at room temperature) comprising the following components in acetone. The prepared acetone solution of the epoxy resin composition of 60% by mass was used (hereinafter, simply referred to as an epoxy solution).
[0025]
(Epoxy resin composition)
Epicoat 828 (manufactured by Japan Epoxy Resin Co., Ltd.) 50 parts by mass Epicoat 1004 (manufactured by Japan Epoxy Resin Co., Ltd.) 30 parts by mass Epicron N740 (manufactured by Dainippon Ink and Chemicals, Inc.) 20 parts by mass DCMU99 (Hodogaya) 5 parts by mass [manufactured by Chemical Co., Ltd.]
(Example 1)
A carbon fiber fabric Pyrofil TRK510 (2/2 twill, fiber weight 646 g / m ² , thickness 0.57 mm) manufactured by Mitsubishi Rayon Co., Ltd. using carbon fibers for warp and weft, was impregnated by immersion in an epoxy solution, The resultant was dried with hot air at 40 ° C. and desolvated to obtain a prepreg having a resin content of 46.7% by mass (resin weight: 564 g / m ² ). When the thickness of this prepreg was measured using calipers, the thickness (A) was 0.85 mm. The carbon fiber woven Pyrofil TR3110 manufactured by Mitsubishi Rayon Co., Ltd. (plain weave, fiber basis weight 200 g / m ² , thickness (B) = 0.23 mm) using carbon fiber as a base material for the warp and the weft was used for the prepreg. It was bonded to one side so that the orientation angle was in the same direction as the prepreg, to obtain an intermediate material for FRP molding. (B) / (A) of this intermediate material was 0.27, the fiber weight of the entire intermediate material was 846 g / m ² , and the resin content was 40% by mass.
The surface of the obtained intermediate material on the prepreg side was attached to a mold, and three plies were laminated with the same orientation at the same orientation angle, and a 500 mm × 500 mm flat plate was oven-molded. The molding conditions were as follows. That is, under the vacuum of 5 Torr or less, the temperature is raised from room temperature to 50 ° C. at a rate of 3 ° C./min, maintained at 50 ° C. × 3 hours, and then raised to 120 ° C. at 0.5 ° C./min. × 2 hours.
Although the obtained FRP panel was oven-molded, as shown in Table 1, no pinhole was observed on the surface, and the center of the FRP panel was cut to observe the inside. No void was found.
[0027]
(Example 2)
A prepreg was prepared in the same manner as in Example 1 except that the resin content was 57.1% by mass (resin weight 861 g / m ² ) and the thickness (A) was 1.1 mm. Using the obtained prepreg as a substrate, TRK510 having the same thickness (B) = 0.57 mm as the reinforcing fiber woven fabric used for the prepreg was attached to one surface at an angle of 45 ° from the orientation direction of the reinforcing fibers of the prepreg, followed by FRP molding. Intermediate material was obtained. (B) / (A) of this intermediate material was 0.52, the fiber weight of the entire intermediate material was 1292 g / m ² , and the resin content was 40% by mass.
The obtained intermediate material for FRP molding is laminated so that the fiber orientation angle of the warp is [−45 ° / 0 ° / 45 ° / 90 ° / 90 ° / 45 ° / 0 ° / -45 °], and the process is performed. An FRP panel was obtained by oven molding in the same manner as in Example 1. However, since the intermediate material in the present example has a two-layer structure of 0 ° / 45 °, four plies were laminated in the unit of the intermediate material.
As shown in Table 1, no pinholes were found on the surface of the obtained FRP panel, and the center of the FRP panel was cut to observe the inside, but no void was found inside.
[0028]
(Example 3)
Example 1 was repeated except that the roving glass cloth WR800 manufactured by Nitto Boss Co., Ltd. was used in place of TRK510, the resin content was 53.3% by mass (resin weight was 450 g / m ² ), and the thickness (A) was 0.71 mm. A prepreg was obtained in the same manner. Further, Pyrofil TR3110 was bonded to one side of the prepreg such that the orientation angles of the warp and the weft were in the same direction as the prepreg to obtain an intermediate material for glass fiber / carbon fiber hybrid FRP molding ((B)). /(A)=0.32.).
The obtained intermediate material of the present invention was laminated four-ply with the same orientation and the same surface in the same direction, and oven-molded in the same manner as in Example 1 to obtain a glass fiber / carbon fiber hybrid FRP. The hybrid FRP could be easily formed by using the intermediate material of the present invention.
As shown in Table 1, no pinholes were found on the surface of the obtained FRP panel, and the center of the FRP panel was cut to observe the inside, but no void was found inside. .
[0029]
(Example 4)
A prepreg was prepared in the same manner as in Example 1 except that the resin content was 51.9% by mass (resin weight, 697.5 g / m ² ) and the thickness (A) was 0.96 mm. Pyrofil TR3110 as a base material was adhered to both the front and back surfaces of the prepreg so that the orientation angle of the warp and the weft was in the same direction as the prepreg, to obtain an intermediate material for FRP molding of the present invention. This intermediate material had (B) / (A) = 0.24, a carbon fiber weight per unit area of the intermediate material of 1064 g / m ² , and a resin content of 40% by mass.
The obtained intermediate material of the present invention was laminated with 10 plies on the same surface in the same direction at the same orientation angle, and oven-molded in the same manner as in Example 1 to obtain an FRP panel.
As shown in Table 1, no pinholes were found on the surface of the obtained FRP panel, and the center of the FRP panel was cut to observe the inside, but no void was found inside.
[0030]
(Example 5)
Instead of the epoxy resin, a methanol solution of phenol resin manufactured by Dainippon Ink and Chemicals, phenolite 5900 (about 60% by mass) was used, the resin content was 57.1% by mass (resin basis weight was 861 g / m ² ), and the thickness was 5%. A prepreg was prepared in the same manner as in Example 1 except that (A) was set to 1.1 mm. Pyrofil TR3110 was bonded to one surface of the carbon fiber so that the carbon fibers were oriented in the same direction to obtain an intermediate material for FRP molding. (B) / (A) of this intermediate material was 0.21, the fiber weight of the entire intermediate material was 1292 g / m ² , and the resin content was 40% by mass.
The obtained three plies of the intermediate material of the present invention were laminated in the same direction, and a 1000 mm × 1000 mm FRP panel was oven-molded. However, the molding conditions were 5 Torr or less, and the temperature was raised to 90 ° C. at a rate of 0.5 ° C./min under the vacuum to 90 ° C. × 20 hours.
As shown in Table 1, no pinholes were found on the surface of the obtained FRP panel, and the center of the FRP panel was cut to observe the inside, but no void was found inside.
[0031]
(Comparative Example 1)
An example in which the base material is not attached to the prepreg will be described. A prepreg was prepared in the same manner as in Example 1, except that the resin content was 40.0% (resin weight 431 g / m ² ) and the thickness (A) was 0.73 mm.
Only the obtained prepreg was laminated in an 8-ply configuration at [−45 ° / 0 ° / 45 ° / 90 ° / 90 ° / 45 ° / 0 ° / -45 °], and oven-molded in the same manner as in Example 1. An FRP panel was obtained.
As shown in Table 1, many pinholes were found on the surface of the obtained FRP panel, and when the center of the FRP panel was cut to observe the inside, many voids were also found inside.
[0032]
(Comparative Example 2)
A prepreg was prepared in the same manner as in Example 1 except that the resin content was 40.5% (resin weight 430 g / m ² ) and the thickness (A) was 0.74 mm. A glass cloth H20F5104 (thickness (B) = 0.04 mm) manufactured by Unitika Glass Fiber Co., Ltd. was bonded as a base material to the prepreg to obtain an intermediate material for FRP molding. (B) / (A) of the intermediate material was 0.05.
This FRP molding intermediate material was oven-molded in the same manner as in Example 1 to obtain an FRP panel. As shown in Table 1, a pinhole was observed on the surface of the obtained FRP panel, and when the center of the FRP panel was cut to observe the inside, voids were also found inside.
[0033]
(Comparative Example 3)
A prepreg was prepared in the same manner as in Example 1 except that the resin content was 32.0% (resin weight 300 g / m ² ) and the thickness (A) was 0.62 mm. A polyester fiber non-woven fabric (fiber basis 132 g / m ² , thickness (B) = 1.7 mm) was attached to the prepreg to obtain an intermediate material for FRP molding. (B) / (A) of the intermediate material for FRP molding was 2.74.
This FRP molding intermediate material was oven-molded in the same manner as in Example 1 to obtain an FRP panel. As shown in Table 1, the obtained FRP panel had a large number of resin-unimpregnated portions on the surface, and when the central portion of the FRP panel was cut to observe the inside, many voids were also found inside.
[0034]
(Example 6)
Carbon fiber Pyrofil TR50S-12L manufactured by Mitsubishi Rayon was aligned in one direction with a fiber basis weight of 190 g / m ² , and resin content was 30.2 mass% (resin basis weight, 82.3 g / m ² ) and thickness as in Example 1. (A) A prepreg of 0.18 mm was prepared. A non-woven fabric (fiber basis weight: 20 g / m ² ) made of nylon 12 fiber having a thickness (B) of 0.32 mm was attached to one surface of the prepreg to obtain an intermediate material for FRP molding ((B) / (A) = 1). .78).
A total of 24 plies were laminated on the obtained intermediate material for FRP molding so that the orientation angle of the carbon fibers was [−45 ° / 0 ° / 45 ° / 90 °] _{3 s} (3 s means that the repeating unit of the lamination is 3 This shows that the repetitions were laminated so as to be mirror-symmetrical, that is, the first 12 plies had the carbon fiber side on the mold side, and the subsequent 12 plies had the carbon fiber side on the side opposite to the mold. ). The laminate was laminated in this way, and oven-molded in the same manner as in Example 1 to obtain an FRP panel.
No pinholes were observed between the surface and the interlayer of the obtained FRP panel. The center of the FRP panel was cut to observe the inside, but no void was found inside. The CAI (residual compressive strength after impact) of this panel was measured. The CAI measurement was performed in accordance with SACMA's SRM2-88 method. The impact applied was 1500 inch-pounds / inch. As a result, the result of CAI measurement of the obtained panel was 350 MPa, which was a high value as FRP.
[0035]
(Comparative Example 4)
A prepreg was prepared in the same manner as in Example 6, except that the resin content was 35.0% (resin basis weight: 102.3 g / m ² ) and the thickness (A) was 0.19 mm. Only the obtained prepreg was laminated in a total of 24 plies so that [-45 ° / 0 ° / 45 ° / 90 °] _{3 s} was obtained, and an FRP was formed by oven molding in the same manner as in Example 1.
In the obtained FRP panel, some voids were observed between the surface and the interlayer. The center of the FRP panel was cut to observe the inside, but voids were also found inside. When the CAI measurement of the obtained panel was performed, it was as low as 210 MPa.
[0036]
[Table 1]

[0037]
【The invention's effect】
As described above, the intermediate material for FRP molding of the present invention is a substrate in which at least one surface of a prepreg composed of a thermosetting resin composition and a reinforcing fiber is not substantially impregnated with the thermosetting resin composition. Are bonded, and the ratio (B) / (A) of the thickness (A) of the prepreg to the thickness (B) of the base material is an intermediate material for FRP molding in which the ratio is (B) / (A) is 0.1 or more and 2.5 or less. Even when manufactured by the lacquer method, it is possible to provide an intermediate material for FRP molding capable of molding FRP which has no pinholes on the surface of the FRP molded by oven molding, has excellent appearance, and has no internal voids.

Claims

A substrate that is not substantially impregnated with the thermosetting resin composition is attached to at least one surface of a prepreg composed of the thermosetting resin composition and the reinforcing fiber, and the thickness (A) of the prepreg and the An intermediate material for FRP molding, wherein the ratio (B) / (A) to the thickness (B) is 0.1 or more and 2.5 or less.

The intermediate material for FRP molding according to claim 1, wherein the prepreg is manufactured by a lacquer method.

The intermediate material for FRP molding according to claim 1 or 2, wherein the substrate is made of a fibrous thermoplastic resin composition.

The intermediate material for FRP molding according to any one of claims 1 to 3, wherein the substrate is a nonwoven fabric of a thermoplastic resin composition.

The intermediate material for FRP molding according to any one of claims 1 to 3, wherein the substrate comprises a reinforcing fiber.

6. The intermediate material for FRP molding according to claim 5, wherein the reinforcing fibers constituting the base material are the same as the reinforcing fibers constituting the prepreg.

7. The intermediate material for FRP molding according to claim 6, wherein the reinforcing fibers constituting the base material form different angles from the reinforcing fibers constituting the prepreg.

6. The intermediate material for FRP molding according to claim 5, wherein the reinforcing fibers constituting the base material are different from the reinforcing fibers constituting the prepreg.

The intermediate material for FRP molding according to any one of claims 1 to 8, wherein the thermosetting resin composition is an epoxy resin or a phenol resin.

The FRP molding intermediate material according to any one of claims 1 to 9, wherein the reinforcing fibers constituting the prepreg are made of carbon fibers and / or glass fibers.

A method for producing an intermediate material for FRP molding, in which a prepreg is prepared by a lacquer method, and then a substrate substantially not impregnated with a resin is attached to at least one surface of the prepreg.

The method for producing an intermediate material for FRP molding according to claim 11, wherein the ratio (B) / (A) of the thickness (A) of the prepreg to the thickness (B) of the base material is 0.1 or more and 2.5 or less.

The method for producing an intermediate material for FRP molding according to claim 11 or 12, wherein acetone is used as a solvent in the lacquer method.