JP3741382B2 - Manufacturing method of prepreg - Google Patents

Description

【００１０】
次に、芳香族ポリアミンについては、４，４’−ジアミノジフェニルメタン、４，４’−ジアミノジフェニルスルフォン、メタフェニレンジアミン、４，４’−ジアミノ−３，３’−ジエチル−５，５’−ジメチルジフェニルメタン、３，３’−ジメトキシ−４，４’−ジアミノジフェニル、３，３’−ジメチル−４，４’−ジアミノジフェニル、２，２’−ジクロロ−４，４’−ジアミノ−５，５’−ジメトキシジフェニル、２，２’，５，５’−テトラクロロ−４，４’−ジアミノジフェニル、４，４’−メチレン−ビス（２−クロロアニリン）、２，２’，３，３’−テトラクロロ−４，４’−ジアミノジフェニルメタン、ビス（４−アミノ−２−クロロ−３，５−ジエチルジフェニル）メタン、４，４’−ヂアミノジフェニルエーテル、３，４’−ジアミノジフェニルエーテル、４，４’−ジアミノベンズアニリド、３，３’−ジハイドロキシ−４，４’−ジアミノビフェニル、９，９’−ビス（４−アミノフェニル）フルオレン、９，１０−ビス（４−アミノフェニル）アントラセン等が例示される。
【００１１】
本願発明において用いられるグアニド化合物は、１−オルソトリルジグアニド、ｐ−クロロフェニルジグアニド、及び、フェニルジグアニドから選ばれるものである。
【００１２】
これらのグアニド化合物の特長は、エポキシ基と反応しエポキシ環が開環する時に非常に発熱が大きいことにあり、従って、加熱によりエポキシ樹脂と付加重合をおこす反応系においては、反応が著しく促進される。本発明では、この特長を利用して成形時間の短縮を達成したものである。走査型熱量計によりエポキシ樹脂の反応を調べると、グアニド化合物が存在しない系でのプリプレグ、例えば、エポキシ樹脂、芳香族ポリアミン、ジシアンジアミドを組成物とするＦＲ−４プリプレグでは、樹脂１ｍｇあたり２０〜４０ｍＪと反応時の発熱量が少なく、且つ、反応開始温度が約１５０℃、反応の活性温度が約１７０℃と高い。即ち、プレス成形時の昇温過程において、反応が進みにくく、且つ完全硬化にいたるまでにより多くの熱量の供給が必要であることを示唆する。一方、エポキシ樹脂、芳香族ポリアミン、グアニド化合物の系では、樹脂１ｍｇあたり６０〜１４０ｍＪと反応時の発熱量が多く、且つ、反応開始温度が約１３０℃、反応の活性温度が約１５０℃と低い。即ち、プレス成形時の昇温過程においてより低温で硬化反応が起こり、発熱により反応がさらに促進され、短い時間で硬化反応が終了することを意味する。
【００１３】
ジシアンジアミドは、良好な銅箔との密着性を付与するために添加されることが好ましい。
【００１４】
配合量について言及する。芳香族ポリアミンについては、エポキシ樹脂１当量に対し、１．２当量を越えない範囲で配合量が多ければ多いほど耐熱性が向上するが、プリプレグの保存性を考慮し、配合量が決定されねばならない。従って、配合量は、０．８当量を越える範囲で配合した場合、通常の市場の要求である保存性３ヶ月を満足することは困難である。一方０．１当量未満の配合量であると耐熱性向上に対する芳香族ポリアミンの添加効果が十分に認められない。従って、芳香族ポリアミンの配合量は０．１〜０．８当量の範囲が好ましい。グアニド化合物の配合量については、グアニド化合物１分子が有するアミンが全て架橋反応に関与するとして当量を計算すると、エポキシ樹脂１当量に対し、０．０５当量以下では発熱量が少なく、充分な速硬化性を得ることができず、０．８当量を超える量を配合した場合、吸湿量が大きくなり、半田耐熱性が低下する傾向にある。従って、０．０５〜０．８当量の配合が適当である。ジシアンジアミドの配合量については、銅箔との密着性、吸湿時の半田耐熱性を考慮し決定される。即ち、エポキシ樹脂１当量に対し、０．１当量未満の配合量であると、銅箔との密着性の向上という観点から添加効果が小さく、０．８当量を越える配合を行った場合、吸湿量が多くなり、吸湿処理後の半田耐熱性の低下の原因になりやく、保存性低下の原因にもつながる。
【００１５】
これら以外の配合物としては特に限定はしない。例えば、ガラス繊維との密着性をあげるために、エポキシシラン、アミノシランに例示されるカップリング剤の添加、あるいは板厚精度を更に向上する目的で、ポリブタジエン系ゴム、ニトリル系ゴム、ニトリルブタジエンゴム、あるいは、そのカルボン酸変性、アミン変性、エポキシ変性物等の添加が可能である。また、プリプレグのゲルタイムの調整、または更なる速硬化性付与のため、イミダゾール化合物、アダクト化イミダゾール、マイクロカプセル化硬化促進剤、ホスフィン系、アミン系促進剤などを添加することに特に制約はない。
【００１６】
【作用】
本発明で得られたプリプレグは速硬化性であるので、積層板を成形する際、その加熱加圧時間を大きく短縮することができる。エポキシ樹脂積層板の場合、通常１回の積層成形で１２０分から２００分程度要していた成形時間が、４０〜６０分程度まで短縮することが可能になった。その結果、製造コストが大幅に削減され、品質管理，在庫管理に費やす工数も大幅に削減されるようになる。また、多層プリント配線基板の成形においてもその成形時間を大幅に短縮することが可能となる。
【００１７】
本発明に用いるナフタレン型エポキシ樹脂は、前述のように、溶融粘度が特に低いという特長を有するため、プリプレグ中でのボイドの残存が少なく、従って成形時間を短縮した場合においても成形後の積層板におけるボイドによる不良を無くすることができる。
【００１８】
また、多層プリント配線基板の製造において、内層回路板にアンダーコート剤を予め塗布しておくことにより、従来のプリプレグを使用した場合に比較して、樹脂のフローが小さいため、板厚精度が良好で、アンダーコート剤の埋め込み効果により外層表面の表面平滑性が高く、よりファインパターン回路の形成が可能である。
【００１９】
【実施例】
以下、本発明を実施例にもとづき詳細に説明する。
【００２０】
（実施例１）
表１に示す組成比のエポキシ樹脂、芳香族ポリアミン及び１−オルソトリルジグアニドから構成されるエポキシ樹脂組成物をガラス繊維織布に含浸、乾燥処理して、１８０μｍ厚、樹脂分４２％のプリプレグを得た。
顕微鏡でプリプレグ内のストランド間のボイド個数を評価したところ６個あり、実用上まったく問題ないレベルであることが確認された。ボイドの評価については、プリプレグを顕微鏡で５０倍の拡大し、経糸、緯糸の交点１つあたりに存在するボイドの個数を数える方法を採用した。従来のＦＲ−４プリプレグを通常の条件で硬化させる際は、ボイド数１５個以内程度におさえれば、成形プレス後の積層板中にまったく残存しないが、本発明の速硬化プリプレグを後述の短時間で硬化させる場合、ボイド数を１０個以内におさえる必要がある。
このプリプレグ６枚とその両面に１８μｍ厚の銅箔を重ね、積層プレスにて圧力３０ｋｇ／ｃｍ² に加圧し、室温から加熱を始め、昇温速度約１８℃／分、最高到達温度１７０℃で成形を行った。最高到達温度に達するのに要した時間は約１０分であった。
【００２１】
成形に必要な加熱時間は、プレス加熱時間とガラス転移温度との関係を調べ、加熱時間１４０分におけるプリプレグのガラス転移温度とほぼ同等のガラス転移温度（±３℃）になるのに要した加熱時間を成形に必要な加熱時間とした。従って、成形に必要な加熱時間は、室温から最高到達温度への昇温時間と最高到達温度における保持時間の和である。ガラス転移温度は粘弾性法を用いた。その結果、成形に必要な加熱時間は４０分であり、その加熱時間における積層板としての特性を表１に示す。
【００２２】
ここで、プリプレグの保存性については、２５℃、６０％の温湿度雰囲気下においてプリプレグを保管し、２週間おきに上記の成形条件により成形を行い、エッチング外観を初期外観と比較をし判定した。プリプレグのライフが過ぎた場合、ボイド残りが発生するため、簡便な方法として外観のチェックにより充分判断は可能である。
【００２３】
（実施例２）
表１に示す組成比のエポキシ樹脂、芳香族ポリアミン、ジシアンジアミド及びｐ−クロロフェニルジグアニドから構成されるエポキシ樹脂組成物をガラス繊維織布に含浸、乾燥処理して、１８０μｍ厚、樹脂分４２％のプリプレグを得た。このプリプレグ６枚とその両面に１８μｍ厚の銅箔を重ね、積層プレスにて圧力３０ｋｇ／ｃｍ^２ に加圧し、室温から加熱を始め、昇温速度約１８℃／分、最高到達温度１７０℃で成形を行った。最高到達温度に達するのに要した時間は約１０分であり、成形に必要な加熱時間は４０分であった。その加熱時間における積層板としての特性を表１に示す。
【００２４】
（実施例３）
表１に示す組成比のエポキシ樹脂、芳香族ポリアミン及びフェニルジグアニドから構成されるエポキシ樹脂組成物をガラス繊維織布に含浸、乾燥処理して、１８０μｍ厚、樹脂分４２％のプリプレグを得た。このプリプレグ６枚とその両面に１８μｍ厚の銅箔を重ね、積層プレスにて圧力３０ｋｇ／ｃｍ^２ に加圧し、室温から加熱を始め、昇温速度約１８℃／分、最高到達温度１７０℃で成形を行った。最高到達温度に達するのに要した時間は約１０分であり、成形に必要な加熱時間は４０分であった。その加熱時間における積層板としての特性を表１に示す。
【００２５】
（比較例１）
エポキシ樹脂、芳香族ポリアミン及び１−オルソトリルジグアニドから構成されるエポキシ樹脂組成物をガラス繊維織布に含浸、乾燥処理して、１８０μｍ厚、樹脂分４２％のプリプレグを得た。このプリプレグ６枚とその両面に１８μｍ厚の銅箔を重ね、積層プレスにて圧力３０ｋｇ／ｃｍ² に加圧し、室温から加熱を始め、昇温速度約１８℃／分、最高到達温度１７０℃で成形を行った。最高到達温度に達するのに要した時間は約１０分であり、成形に必要な加熱時間は６０分であった。その加熱時間における積層板としての特性を表１に示す。
【００２６】
（比較例２）
エポキシ樹脂、芳香族ポリアミン及びジシアンジアミドのみから構成されるエポキシ樹脂組成物をガラス繊維織布に含浸、乾燥処理して、１８０μｍ厚、樹脂分４２％のプリプレグを得た。このプリプレグ６枚とその両面に１８μｍ厚の銅箔を重ね、積層プレスにて圧力３０ｋｇ／ｃｍ² に加圧し、室温から加熱を始め、昇温速度約１８℃／分、最高到達温度１７０℃で成形を行った。最高到達温度に達するのに要した時間は約１０分であり、成形に必要な加熱時間は１２０分であった。その加熱時間における積層板としての特性を表１に示す。
【００２７】
【表１】

【００２８】
【化３】

【００２９】
【発明の効果】
以上述べたように、本発明の方法により得られたプリプレグは、残存するボイドが非常に少なく、速硬化性であるので、電気用積層板を成形するのに要する時間を大幅に短縮することができる。また、多層プリント配線基板の成形においても、層間絶縁材として使用することにより成形時間を短縮することができる。特に、内層回路板の表面にアンダーコート剤を塗布しておくことにより、成形時間の短縮だけでなく、得られた基板の厚み精度が良好で、表面平滑性に優れた多層プリント配線基板を得ることができる。[0001]
[Industrial application fields]
The present invention relates to a prepreg used for electrical laminates such as copper-clad laminates and multilayer printed wiring boards, and more particularly to a method for producing a prepreg for shortening the time required for forming the laminate.
[0002]
[Prior art]
Conventionally, electrical laminates such as copper-clad laminates are made by impregnating and drying glass fiber or paper with a thermosetting resin such as epoxy resin or phenol resin to form a prepreg. Accordingly, a metal foil such as a copper foil is overlaid, and this is manufactured by heating and pressing. In addition, the multilayer prepreg wiring board is manufactured by forming a circuit on the surface of the laminated board obtained by the above method to form an inner circuit board, and usually superimposing a prepreg and a metal foil on both sides and heating and pressing. Yes.
In recent years, these laminated boards have a tendency toward high-density mounting and high integration of printed wiring boards, and demands for various properties such as workability, heat resistance, and moldability have been advanced and multifaceted. Among these, regarding moldability, it is strongly desired that the molding time can be shortened without lowering other characteristics. For this reason, shortening the hardening time of the resin used for the prepreg has been studied. For example, in the case of epoxy resins, various combinations of curing agents and curing accelerators have been proposed.
[0003]
[Problems to be solved by the invention]
However, in any prescription, the molding time can be shortened to some extent, but it is not sufficient, and if the molding time is further shortened, defects such as deterioration of heat resistance and electrical properties after high-humidity treatment appear.
As a result of various studies on the forming technique of the laminated plate, the present inventors have succeeded in achieving a reduction in forming time, which was insufficient with the conventional technique, without reducing other characteristics. .
[0004]
[Means for Solving the Problems]
The present invention impregnates and dries a varnish comprising (a) an epoxy resin having two or more epoxy groups, (b) an aromatic polyamine, and (c) an epoxy resin composition containing a specific guanide compound. In the method for producing a prepreg, the present invention relates to a method for producing a prepreg in which 10 to 50% by weight of the epoxy resin is a specific epoxy resin having a naphthalene skeleton (hereinafter referred to as a naphthalene type epoxy resin).
[0005]
In the present invention, as the (a) epoxy resin having two or more epoxy groups, any one conventionally used for electrical insulation can be used. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, orthocresol novolak type epoxy resin, isocyanurate type epoxy resin, or trifunctional, tetrafunctional glycidylamine type epoxy resin, epoxy resin having biphenyl skeleton (biphenyl type epoxy resin) , Naphthalene type epoxy resins, epoxy resins having a cyclopentadiene skeleton, and epoxy resins having a limonene skeleton. These can be used alone or in combination. Among such epoxy resins, in the present invention, naphthalene type epoxy resin is preferable in view of the fact that there are few voids in the prepreg, the linear expansion coefficient after curing is small, and the dimensional stability is excellent.
[0006]
Furthermore, in order to impart flame retardancy, a blend of the above-mentioned epoxy resin brominated is blended, and the above-mentioned epoxy resin is co-condensed with epoxytetrabromobisphenol A and bisphenol A. Any method is possible, such as blending bromobisphenol A and bisphenol A, blending tetrabromobisphenol A with the aforementioned epoxy resin, or blending brominated epoxyphenol novolac with the aforementioned epoxy resin.
[0007]
In the prepreg manufacturing process, the epoxy resin composition is usually dissolved in a solvent and then impregnated into a glass cloth, and the solvent is evaporated at a temperature of about 150 ° C. to 170 ° C. to obtain a B-stage state. If the melt viscosity of the epoxy resin after evaporation is high, there is a drawback that voids tend to remain between the strands of the glass cloth. In the prepreg having a shortened curing time of the present invention, the greatest feature is that the time until the final curing is shortened as compared with the conventional prepreg, and therefore, if voids remain in the prepreg, lamination after curing Incorporates the drawback of being easily left in the plate. As a result of various studies on epoxy resins, it has been found that lowering the melt viscosity at the drying temperature of the prepreg is effective in reducing voids. As a representative epoxy resin having a low melt viscosity , a naphthalene type epoxy resin represented by the following chemical formula (1) is used in the present invention. Considering other characteristics, this epoxy resin is preferably contained in an amount of 10 to 50% by weight based on the total epoxy resin. If it is less than 10% by weight , the effect of lowering the viscosity is small, and if it exceeds 50% by weight , the crosslink density of the cured product tends to be low and the glass transition temperature tends to be low. Furthermore, as for the polymerization degree of this naphthalene type epoxy resin, it is desirable that n number which shows a polymerization degree is the range of n = 0-2. When n = 2 is exceeded, the molecular weight increases and the effect of lowering the viscosity tends to decrease.
[0008]
The naphthalene type epoxy resin has a feature that the melt viscosity is particularly low because the naphthalene skeleton in the molecule has a high molecular orientation and a very high crystallinity. For this reason, there is little remaining of voids in the prepreg, and defects due to voids in the formed laminated board can be eliminated. Further, since it has a naphthalene ring in the main chain, it has a small coefficient of linear expansion after curing and is excellent in dimensional stability, so that cracks are not easily generated in plating through holes .
[0009]
[Chemical 2]

[0010]
Next, for aromatic polyamines, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylsulfone, metaphenylenediamine, 4,4′-diamino-3,3′-diethyl-5,5′-dimethyl. Diphenylmethane, 3,3′-dimethoxy-4,4′-diaminodiphenyl, 3,3′-dimethyl-4,4′-diaminodiphenyl, 2,2′-dichloro-4,4′-diamino-5,5 ′ -Dimethoxydiphenyl, 2,2 ', 5,5'-tetrachloro-4,4'-diaminodiphenyl, 4,4'-methylene-bis (2-chloroaniline), 2,2', 3,3'- Tetrachloro-4,4'-diaminodiphenylmethane, bis (4-amino-2-chloro-3,5-diethyldiphenyl) methane, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphe Ether, 4,4′-diaminobenzanilide, 3,3′-dihydroxy-4,4′-diaminobiphenyl, 9,9′-bis (4-aminophenyl) fluorene, 9,10-bis (4-amino) Phenyl) anthracene and the like are exemplified.
[0011]
The guanide compound used in the present invention is selected from 1-orthotolyl diguanide, p-chlorophenyl diguanide, and phenyl diguanide.
[0012]
The feature of these guanide compounds is that they generate a large amount of heat when they react with an epoxy group and the epoxy ring is opened. Therefore, in a reaction system that undergoes addition polymerization with an epoxy resin by heating, the reaction is remarkably accelerated. The In the present invention, this feature is used to reduce the molding time. When the reaction of the epoxy resin is examined by a scanning calorimeter, in a prepreg in a system in which no guanide compound is present, for example, an FR-4 prepreg having an epoxy resin, an aromatic polyamine, and dicyandiamide as a composition, 20 to 40 mJ per 1 mg of the resin. In addition, the amount of heat generated during the reaction is small, the reaction start temperature is about 150 ° C., and the reaction activation temperature is about 170 ° C. That is, it is suggested that in the temperature rising process during press molding, the reaction is difficult to proceed, and that more heat must be supplied until complete curing is achieved. On the other hand, in the system of epoxy resin, aromatic polyamine, and guanide compound, 60 to 140 mJ per 1 mg of resin, the amount of heat generated during the reaction is large, the reaction start temperature is about 130 ° C., and the reaction activation temperature is as low as about 150 ° C. . That is, it means that the curing reaction occurs at a lower temperature in the temperature rising process during press molding, the reaction is further accelerated by heat generation, and the curing reaction is completed in a short time.
[0013]
Dicyandiamide is preferably added to provide good adhesion to the copper foil.
[0014]
It mentions about compounding quantity. For aromatic polyamines, the heat resistance improves as the blending amount increases within a range not exceeding 1.2 equivalents per 1 equivalent of epoxy resin, but the blending amount must be determined in consideration of the storage stability of the prepreg. Don't be. Accordingly, when the blending amount is in a range exceeding 0.8 equivalent, it is difficult to satisfy the normal market requirement of 3 months of storage. On the other hand, when the blending amount is less than 0.1 equivalent, the effect of adding aromatic polyamine for improving heat resistance is not sufficiently observed. Therefore, the blending amount of the aromatic polyamine is preferably in the range of 0.1 to 0.8 equivalent. As for the compounding amount of the guanide compound, when the equivalent is calculated on the assumption that all the amines contained in one molecule of the guanide compound are involved in the crosslinking reaction, the amount of heat generated is less than 0.05 equivalent with respect to 1 equivalent of epoxy resin, and sufficient rapid curing is achieved. When the amount exceeding 0.8 equivalent is blended, the moisture absorption amount increases and the solder heat resistance tends to decrease. Therefore, a blend of 0.05 to 0.8 equivalent is appropriate. The blending amount of dicyandiamide is determined in consideration of the adhesion to the copper foil and the solder heat resistance during moisture absorption. That is, when the blending amount is less than 0.1 equivalent with respect to 1 equivalent of epoxy resin, the effect of addition is small from the viewpoint of improving the adhesion to the copper foil. The amount increases, which tends to cause a decrease in solder heat resistance after moisture absorption treatment, and also causes a decrease in storage stability.
[0015]
There are no particular limitations on the blends other than these. For example, in order to increase adhesion with glass fiber, for the purpose of further improving the plate thickness accuracy, or addition of a coupling agent exemplified by epoxysilane and aminosilane, polybutadiene rubber, nitrile rubber, nitrile butadiene rubber, Alternatively, the carboxylic acid modification, amine modification, epoxy modification, etc. can be added. Moreover, there is no restriction | limiting in particular in the addition of an imidazole compound, adduct imidazole, a microencapsulation hardening accelerator, a phosphine type | system | group, an amine type accelerator, etc. for adjustment of the gel time of a prepreg, or provision of further quick curability.
[0016]
[Action]
Since the prepreg obtained in the present invention is fast-curing, the heating and pressurizing time can be greatly shortened when a laminated board is formed. In the case of an epoxy resin laminated board, the molding time that normally required about 120 to 200 minutes in one lamination molding can be shortened to about 40 to 60 minutes. As a result, manufacturing costs are greatly reduced, and man-hours spent on quality control and inventory management are also greatly reduced. Also, the molding time can be greatly shortened in the molding of the multilayer printed wiring board.
[0017]
As described above, the naphthalene type epoxy resin used in the present invention has a feature that the melt viscosity is particularly low. Therefore, there is little residual void in the prepreg, and therefore even when the molding time is shortened, the laminated board after molding. It is possible to eliminate defects caused by voids.
[0018]
Also, in the manufacture of multilayer printed wiring boards, by applying an undercoat agent to the inner circuit board in advance, the resin flow is smaller compared to the case of using a conventional prepreg, so the board thickness accuracy is good Thus, the surface smoothness of the outer layer surface is high due to the embedding effect of the undercoat agent, and a fine pattern circuit can be formed more.
[0019]
【Example】
Hereinafter, the present invention will be described in detail based on examples.
[0020]
Example 1
A glass fiber woven fabric is impregnated with an epoxy resin composition composed of an epoxy resin having the composition ratio shown in Table 1, an aromatic polyamine, and 1-orthotolyl diguanide, and dried to give a thickness of 180 μm and a resin content of 42% A prepreg was obtained.
When the number of voids between the strands in the prepreg was evaluated with a microscope, there were six, and it was confirmed that the level was not a problem in practical use. For evaluation of voids, a method was adopted in which the prepreg was magnified 50 times with a microscope and the number of voids present at each intersection of warp and weft was counted. When the conventional FR-4 prepreg is cured under normal conditions, it does not remain in the laminated sheet after the molding press as long as the number of voids is within 15 or less. When curing with, the number of voids must be kept within 10.
Six prepregs and 18 μm thick copper foil are stacked on both sides of the prepreg, pressurized to 30 kg / cm ² with a laminating press, heated from room temperature, heated at a rate of about 18 ° C./min, with a maximum temperature of 170 ° C. Molding was performed. The time required to reach the maximum temperature was about 10 minutes.
[0021]
The heating time required for forming was determined by examining the relationship between the press heating time and the glass transition temperature, and the heating required to reach a glass transition temperature (± 3 ° C.) that was almost the same as the glass transition temperature of the prepreg at a heating time of 140 minutes. The time was defined as the heating time required for molding. Therefore, the heating time required for molding is the sum of the temperature rising time from room temperature to the highest temperature and the holding time at the highest temperature. For the glass transition temperature, a viscoelastic method was used. As a result, the heating time required for molding was 40 minutes, and the characteristics as a laminated board during the heating time are shown in Table 1.
[0022]
Here, the storability of the prepreg was determined by storing the prepreg in a temperature and humidity atmosphere of 25 ° C. and 60%, molding it under the above molding conditions every two weeks, and comparing the etching appearance with the initial appearance. . When the life of the prepreg has passed, voids remain, so that it is possible to make a sufficient judgment by checking the appearance as a simple method.
[0023]
(Example 2)
A glass fiber woven fabric is impregnated with an epoxy resin composition composed of an epoxy resin, an aromatic polyamine, dicyandiamide and p-chlorophenyl diguanide having a composition ratio shown in Table 1, and dried to give a thickness of 180 μm and a resin content of 42%. Prepreg was obtained. Six prepregs and 18 μm thick copper foil are stacked on both sides of the prepreg, pressurized to 30 kg / cm ² with a laminating press, heated from room temperature, heated at a rate of about 18 ° C./min, with a maximum temperature of 170 ° C. Molding was performed. The time required to reach the maximum temperature was about 10 minutes, and the heating time required for molding was 40 minutes. Table 1 shows the characteristics of the laminated plate during the heating time.
[0024]
Example 3
A glass fiber woven fabric is impregnated with an epoxy resin composition composed of an epoxy resin having the composition ratio shown in Table 1 and an aromatic polyamine and phenyl diguanide and dried to obtain a prepreg having a thickness of 180 μm and a resin content of 42%. It was. Six prepregs and 18 μm thick copper foil are stacked on both sides of the prepreg, pressurized to 30 kg / cm ² with a laminating press, heated from room temperature, heated at a rate of about 18 ° C./min, with a maximum temperature of 170 ° C. Molding was performed. The time required to reach the maximum temperature was about 10 minutes, and the heating time required for molding was 40 minutes. Table 1 shows the characteristics of the laminated plate during the heating time.
[0025]
(Comparative Example 1)
A glass fiber woven fabric was impregnated with an epoxy resin composition composed of an epoxy resin, an aromatic polyamine, and 1-orthotolyl diguanide and dried to obtain a prepreg having a thickness of 180 μm and a resin content of 42%. Six prepregs and 18 μm thick copper foil are stacked on both sides of the prepreg, pressurized to 30 kg / cm ² with a laminating press, heated from room temperature, heated at a rate of about 18 ° C./min, with a maximum temperature of 170 ° C. Molding was performed. The time required to reach the maximum temperature was about 10 minutes, and the heating time required for molding was 60 minutes. Table 1 shows the characteristics of the laminated plate during the heating time.
[0026]
(Comparative Example 2)
A glass fiber woven fabric was impregnated with an epoxy resin composition composed only of an epoxy resin, an aromatic polyamine and dicyandiamide and dried to obtain a prepreg having a thickness of 180 μm and a resin content of 42%. Six prepregs and 18 μm thick copper foil are stacked on both sides of the prepreg, pressurized to 30 kg / cm ² with a laminating press, heated from room temperature, heated at a rate of about 18 ° C./min, with a maximum temperature of 170 ° C. Molding was performed. The time required to reach the maximum temperature was about 10 minutes, and the heating time required for molding was 120 minutes. Table 1 shows the characteristics of the laminated plate during the heating time.
[0027]
[Table 1]

[0028]
[Chemical 3]

[0029]
【The invention's effect】
As described above, since the prepreg obtained by the method of the present invention has very few remaining voids and is fast-curing, the time required for forming an electrical laminate can be greatly reduced. it can. Also in the formation of a multilayer printed wiring board, the molding time can be shortened by using it as an interlayer insulating material. In particular, by applying an undercoat agent to the surface of the inner layer circuit board, not only shortening the molding time, but also obtaining a multilayer printed wiring board with good thickness accuracy of the obtained board and excellent surface smoothness. be able to.

Claims (2)

In the method for producing a prepreg in which a fiber base material is impregnated and dried with a varnish composed of an epoxy resin composition, the epoxy resin composition comprises:
(A) an epoxy resin having two or more epoxy groups,
(B) an aromatic polyamine, and (c) 1- orthotolyl diguanide , p-chlorophenyl diguanide , and a guanide compound selected from phenyl diguanide,
The equivalent ratio is (a) 1 equivalent of an epoxy resin having two or more epoxy groups,
(B) 0.1-0.8 equivalent of an aromatic polyamine,
(C) guanide compound 0.05-0.8 equivalent,
And 10 to 50% by weight of the epoxy resin is an epoxy resin having a naphthalene skeleton represented by the following chemical formula (1).

(N = integer from 0 to 2) In the method for producing a prepreg in which a fiber base material is impregnated and dried with a varnish composed of an epoxy resin composition, the epoxy resin composition comprises:
(A) an epoxy resin having two or more epoxy groups,
(B) an aromatic polyamine,
(C) a guanide compound selected from 1- orthotolyl diguanide , p-chlorophenyl diguanide , and phenyl diguanide, and
(D) dicyandiamide,
The equivalent ratio is (a) 1 equivalent of an epoxy resin having two or more epoxy groups,
(B) 0.1-0.8 equivalent of an aromatic polyamine,
(C) guanide compound 0.05-0.8 equivalent,
(D) dicyandiamide 0.1 to 0.8 equivalents,
And 10 to 50% by weight of the epoxy resin is an epoxy resin having a naphthalene skeleton represented by the chemical formula (1).