JP4538873B2 - Thermosetting resin composition, prepreg using the same, and laminate for electric wiring board - Google Patents

Description

用いられるイソシアネート化合物は、ポリメチレン・ポリフェニル・ポリイソシアネート、トリレンジイソシアネート、ナフチレン−１、５−ジイソシアネート等の２官能および多官能イソシアネート化合物およびその多量体や、アルコールやフェノールによりマスクされたブロックイソシアネートおよびウレタン化合物などが挙げられるがこれらに限定されず、また使用するイソシアネート化合物は２種以上組合わせてもよい。好ましくは２官能イソシアネート化合物であり、これは官能基数が多すぎた場合には貯蔵安定性が低下するためである。
また、ジシクロペンタジエン型エポキシ樹脂は、ジシクロペンタジエン骨格を分子中に有するエポキシ樹脂で、式（２）で示されるエポキシ樹脂である。
【化２】

オキサゾリン環を分子骨格に含むエポキシ樹脂は旭チバ（株）から、ジシクロペンタジエン型エポキシ樹脂は大日本インク（株）からそれぞれ市販されている。
【０００７】
ジヒドロベンゾオキサジン環を有する熱硬化性樹脂（ｂ）としては、ジヒドロベンゾオキサジン環を有し、ジヒドロベンゾオキサジン環の開環反応により硬化する樹脂であれば特に限定されるものではなく、フェノール性水酸基を有する化合物、ホルマリンおよび一級アミンから次式により合成される。
【化３】

(但し、式中のＲ１はアルキル基、シクロヘキシル基、フェニル基またはアルキル基もしくはアルコキシル基で置換されたフェニル基である。)
【０００８】
フェノール性水酸基を有する化合物としては、多官能フェノール、ビフェノール化合物、ビスフェノール化合物、トリスフェノール化合物、テトラフェノール化合物、フェノール樹脂があげられる。多官能フェノールとしてはカテコール、ヒドロキノン、レゾルシノールがあげられる。ビスフェノール化合物としては、ビスフェノールＡ、ビスフェノールＦおよびその位置異性体、ビスフェノールＳ、テトラフルオロビスフェノールＡがあげられる。またフェノール樹脂としてはレゾール樹脂、フェノールノボラック樹脂、フェノール変性キシレン樹脂、アルキルフェノール樹脂、メラミンフェノール樹脂、ベンゾグアナミンフェノール樹脂、フェノール変性ポリブタジエン等があげられる。
一級アミンとしては、具体的にはメチルアミン、シクロヘキシルアミン、アニリン、置換アニリン等があげられる。
ジヒドロベンゾオキサジン環を有する熱硬化性樹脂は、フェノール性水酸基を有する化合物と一級アミンとの等モル混合物を７０℃以上に加熱したホルムアルデヒド中に添加して、７０〜１１０℃、好ましくは９０〜１００℃で２０〜１２０分反応させ、その後１２０℃以下の温度で減圧乾燥することにより合成することができる。
【０００９】
本発明のフェノール類とトリアジン環を有する化合物とアルデヒド類との重縮合物である変性フェノール樹脂（ｃ）を得るために用いられるフェノール類としては、フェノールまたはビスフェノールＡ、ビスフェノールＦ、ビスフェノールＳなどの多価フェノール類や、クレゾール、キシレノール、エチルフェノール、ブチルフェノールなどのアルキルフェノール類、アミノフェノール、フェニルフェノールなどがあげられ１種類または２種以上の併用も可能である。好ましくはフェノールとビスフェノールＡの組合せ、または、フェノールとアルキルフェノールを組合せである。この場合にはフェノールを単独で使用した場合より反応性が抑制され成形性にすぐれ、ビスフェノールＡやアルキルフェノールを単独で使用した場合より難燃性に優れ好ましい。
また、トリアジン環を有する化合物としては、メラミンまたはベンゾグアナミン、アセトグアナミンなどのグアナミン誘導体、シアヌル酸またはメチルシアヌレート、エチルシアヌレートなどのシアヌル酸誘導体や、イソシアヌル酸またはメチルイソシアヌレート、エチルシアヌレートなどのイソシアヌル酸誘導体などがあげられる。好ましくは耐熱性や難燃性が良好になり低価格なメラミンが適しており、トリアジン環を有する化合物の種類、使用量を目的に合わせて選定し窒素含有量を調整し難燃性、反応性、耐熱性の最適化が可能である。
アルデヒド類としては、ホルムアルデヒド、パラホルムアルデヒド、トリオキサン、テトラオキシメチレン等が挙げられこれらに限定されるものではないが、取扱いの容易さから、ホルムアルデヒドが好ましく、特にホルマリン、パラホルムアルデヒドが好ましい。
【００１０】
本発明で使用する変性フェノール樹脂の合成方法としては、まずフェノール類とアルデヒド類とトリアジン環を有する化合物とを塩基性あるいは酸性触媒化で反応させる。この時系のｐＨは特に限定されるものではないがトリアジン環を含む化合物の多くが塩基性溶液に容易に溶解することから、塩基性触媒下で反応させることが好ましく、さらにはアミン類の使用が好ましい。また、各原料の反応順序も特に制限はなく、フェノール類、アルデヒド類をまず反応させてからトリアジン環を有する化合物を加えても、逆にトリアジン環を有する化合物とアルデヒド類を反応させてからフェノール類を加えても、同時にすべての原料を加えて反応させてもよい。
このとき、フェノール類に対するアルデヒド類のモル比は特に限定されるものではないが０．２〜１．５で、好ましくは０．４〜０．８である。またフェノール類に対するトリアジン環を有する化合物との重量比は１０〜９８：９０〜２で好ましくは５０〜９５：５０〜５である。フェノール類の重量比が１０％未満では樹脂化することが困難となり、９８％を越えると充分な難燃効果が得ることができなくなる。また触媒として特に限定されるものではないが代表的なものとして水酸化ナトリウム、水酸化カリウム、水酸化バリウム等のアルカリ金属およびアルカリ土類金属の水酸化物およびこれらの酸化物、アンモニア、１〜３級アミン類、ヘキサメチレンテトラミン、炭酸ナトリウム等、そして塩酸、硫酸、スルホン酸等の無機酸、シュウ酸、酢酸等の有機酸、ルイス酸、あるいは酢酸亜鉛などの２価金属塩等がある。
金属などの無機物が触媒残として残ることは好ましくないことから、塩基性の触媒としてはアミン類、酸性の触媒としては有機酸を使用することが好ましい。触媒の添加量としてはフェノール１００重量部に対し０．１〜１重量部が用いられる。
【００１１】
また反応制御の面から反応をメチルエチルケトン等の各種溶剤の存在化で行ってもよい。次に必要に応じて中和、水洗して塩類などの不純物を除去する。ただし触媒にアミン類を使用した場合は行わないことが好ましい。反応は、７０〜９０℃にて２〜４時間実施し、反応終了後、未反応のアルデヒド類、フェノール類、溶剤等を常圧蒸留、真空蒸留等の常法にしたがって除去する。この時、未反応のアルデヒド類とメチロール類を除去することが好ましく、未反応のアルデヒド類とメチロール基を実質的に含まない樹脂組成物を得るためには１２０℃以上の加熱処理を追加で実施する必要がある。このときノボラック樹脂を得るときの常法にしたがい充分に加熱、蒸留することが好ましい。特に限定されるわけではないが、またこのとき未反応官能性のフェノール単量体を２％以下にすることが好ましい。
さらに、本発明の変性フェノール樹脂を数種組み合わせたり、他のフェノール類のノボラック樹脂と併用して硬化剤として使用することにより単独では得られない成形性や難燃性、耐熱性を得ることが可能であり目的に応じ併用してもよい。
【００１２】
添加剤としては、無機充填剤として水酸化アルミニウム、水酸化マグネシウム、ゼオライトやハイドロタルサイト等の無機水和物、クレー、タルク、ワラストナイト、マイカ、炭酸カルシウム、炭酸マグネシウム、アルミナ、シリカ、ガラス粉などの汎用無機充填剤や、ホウ酸亜鉛、スズ酸亜鉛、ヒドロキシスズ酸亜鉛などのＢ、Ｓｎ系充填剤や、酸化亜鉛、酸化スズなどの金属酸化物、または、赤リンなどの無機リン系材料や、銅や亜鉛などの硝酸塩などを限定なく目的に応じて使用可能であり、またこれら無機充填剤をシランカップリング剤やチタネートカップリング剤などによりコートまたは処理して使用することにより有機成分との接着性や、耐熱性、温湿度に対する安定性や安全性が増し好ましい。
【００１３】
また、非ハロゲン材料のみを使用して目標の難燃性を達成するためには、本発明のエポキシ樹脂組成物においてもトリアジン環の含有率つまり難燃化に効果のあるＮ含有率は、ジヒドロベンゾオキサジン環を有する化合物とフェノ−ル類とトリアジン環を有する化合物とアルデヒド類の重縮合物に含まれるＮ量から、樹脂固形分中の５重量％程度までが限界であり、難燃性ＵＬ９４Ｖ−１またはＵＬ９４Ｖ−０達成のためには、他の特性や成形性を無視して特殊なエポキシ樹脂を使用するか、フェノール樹脂組成物を極端に増量しないかぎり不可能である。そのため、難燃性ＵＬ９４Ｖ−１またはＵＬ９４Ｖ−０達成のためには添加物による難燃補助作用が必要である。そのため、変性エポキシ樹脂１００重量部に対し、無機充填剤を５重量部以上添加して可燃性物質の存在率を減少させることが好ましく、さらに難燃性ＵＬ９４Ｖ−０達成のためには無機充填剤として無機水和物を３０重量部以上使用することが好ましい。
しかしながら、無機充填剤の添加重が２５０重量部を超えると、得られるエポキシ樹脂組成物は金属箔との接着性が著しく低下すると同時に、耐熱性や加工性、絶縁性などが目標を達成できない上、不織布や織布基材等と複合成形する際に欠陥なしに成形することが不可能となるため２５０重量部以下が好ましい。
これらの成分のほかに、必要に応じて、着色剤、酸化防止剤、還元剤、紫外線不透過剤などを配合することができる。
【００１４】
上記樹脂組成物を用いてプリプレグを作製する際に使用する織布および不織布の基材としては、紙、コットンリンターのような天然繊維基材、アラミド、ポリビニルアルコール、ポリエステル、アクリルのような有機合成繊維基材、ガラス、アスベストのような無機繊維基材が使用される。耐燃性の見地から、ガラス繊維基材が好ましい。ガラス繊維基材としては、Ｅガラス、Ｃガラス、Ｄガラス、Ｓガラスなどを使用した織布や短繊維を有機バインダーで接着したガラス不織布、さらに、ガラス繊維とセルロース繊維とを混抄したものがある。
これらを配合したワニスは従来と同様に、織布や不織布などの基材に含浸させてプリプレグを製造し、プリプレグを重ねあわせその両面に銅箔を構成後、加圧、加熱プレスすることにより、銅張り積層板を製造することが出来る。
【００１５】
本発明は、芳香族成分が多く熱分解がしにくく、難燃性に優れたジヒドロベンゾオキサジン環を有する化合物を使用し、さらに、硬化剤として難燃性を高めるＮを含有するトリアジン環を有したフェノール樹脂組成物を使用するため、安定した状態で分子構造中にＮを多量に取り込み、さらに難燃性を高める作用を有する添加物として無機物を添加併用することにより、これらの難燃作用や作用温度域の異なる難燃剤の併用により、各々の難燃剤を単独で使用した場合に比較して相乗効果を得ることが可能となり安定かつ難燃性、および他特性バランスのすぐれたエポキシ樹脂組成物を得ることが可能である。
さらに、式（１）に示したようなオキサゾリジノン環を含むエポキシ樹脂は、耐熱性、難燃性にすぐれ、構造上から可撓性、耐熱性が良好なオキサゾリン環を有するとともに、平均ｎ＝０〜２と反応点のＯＨ基が少ないため、可撓性、靭性を合わせもつため、外形打ち抜き時の層間剥離の低減に効果がある。また、ジシクロペンタジエン型エポキシを使用することにより、層間の接着性が向上し、外形打ち抜き時の層間剥離の低減に効果がある。
【００１６】
【実施例】
以下に本発明を実施例により詳しく説明するが、本発明はこの実施例のみに限定されるものではない。以下、部は「重量部」を、％は「重量％」を示すものとする。
参考例１、実施例２、参考例３、実施例４および実施例５、比較例１〜２〔１〕ジヒドロベンゾオキサジン環を有する樹脂の合成(１)フェノールノボラックの合成フェノール１.９Ｋｇ、ホルマリン(３７％水溶液)１.１５Ｋｇ、しゅう酸４gを５リットルフラスコに仕込み、還流温度で６時間反応させた。引続き、内部を６６６６.１Ｐａ以下に減圧して未反応のフェノールおよび水を除去した。得られた樹脂は軟化点８９℃(環球法)、３核体以上/２核体比=８９/１１(ゲル浸透クロマトグラフィーによるピーク面積比)であった。以下得られた樹脂を(Ａ１)と略記する。
(２)ジヒドロベンゾオキサジン環の導入上記により合成したフェノールノボラック樹脂１.７Ｋｇ(ヒドロキシル基１６ｍｏｌ)をアニリン１.４９Ｋｇ(１６ｍｏｌ）と８０℃で５時間撹絆し、均一な混合溶液を調整した。５リットルフラスコ中に、ホルマリン１.６２Ｋｇを仕込み９０℃に加熱し、ここヘノボラック／アニリン混合溶液を３０分間かけて少しずつ添加した。添加終了後３０分間、還流温度に保ち、然る後に１００℃で２時間６６６６．１Ｐａ以下に減圧して縮合水を除去し、反応しうるヒドロキシル基の９５％がジヒドロベンゾオキサジン化された熱硬化性樹脂を得た。以下得られた樹脂を(Ｂ１)と略記する。
【００１７】
〔２〕変性フェノール樹脂組成物の合成例
フェノール９４部に４１.５％ホルマリン２９部、およびトリエチルアミン０．４７部を加え８０℃にて３時間反応させた。メラミンを１９部加えさらに１時間反応させた後、常圧下にて水を除去しながら１２０℃まで昇温し、温度を保持したまま２時間反応させた。次に常圧下にて水を除去しながら１８０℃まで昇温し、減圧下にて未反応のフェノールを除去し、軟化点１３６℃のフェノールとメラミンの反応物であるフェノール樹脂組成物を得た。以下得られた樹脂を(Ｃ１)と略記する。
フェノールとメラミンの重量比率、未反応ホルムアルデヒド量、メチロール基の存在の有無、および未反応フェノールモノマー量を求め結果を表１に示した。
【表１】

【００１８】
〔３〕その他の配合物
エポキシ樹脂
（ａ）フェノールノボラック型エポキシ樹脂（ＤＥＮ４３０ ダウケミカル（株）製商品名）
エポキシ当量１７０〜１８０ｇ／ｅｑ、常温で液状
（ｂ）オキサゾリジノン環を含むエポキシ樹脂（ＡＥＲ４１５２ 旭チバ（株）製商品名）
エポキシ当量３３０〜３６０ｇ／ｅｑ、 イソシアネート化合物:トリレンジイソシアネートｎ＝０．１５〜０．２５
（ｃ）ジシクロペンタジエン型エポキシ樹脂（ＥＶＡ−７２００Ｈ、大日本インキ（株）製商品名）
エポキシ当量２８０〜２９０ｇ／ｅｑ
無機充填剤
・水酸化アルミニウム（ＣＬ−３０３ 住友化学（株）製商品名）
電子材料用に一般的に用いられている残留イオン等の少ないもので、粒径が３〜５μｍのものを使用した。
【００１９】
〔４〕積層板の作製
表２に示した固形分配合の樹脂組成物をメチルエチルケトンに溶解させ、溶液の不揮発分を６５〜７５％になるようにメチルエチルケトンで調整した。しかる後、各々の混合溶液をガラスクロス(０．２ｍｍ厚)に含浸させ、１６０℃で４分間乾燥してプリプレグを得た。このプリプレグを８枚重ね、その両面に１８μｍの銅箔を重ね、１８０℃、圧４ＭＰａにて１００分間加熱加圧成形して厚さ１.６ｍｍの両面銅張り積層板を得た。
【００２０】
以上作製した両面銅箔張積層板について外形打ち抜き加工時に発生する層間剥離の発生量、耐燃性、耐湿耐熱性、Ｔｇを調べた。その結果を表２に示す。
なお、試験方法は以下の通りとした。
外形打ち抜き加工時発生層間剥離量：作製した両面銅張り積層板の銅はくをエッチングにより除去し、試料とし、ＤＩＮ金型を使用し、層間剥離量を実測して求めた。
耐燃焼性：ＵＬ９４に準拠する。
はんだ耐熱性：１２１℃、２１３０ｈＰａのプレッシャークッカー処理装置内に６時間保持後の試験片(５０ｍｍ×５０ｍｍの片面半銅付き)を、２６０℃に加熱されたはんだ槽に３０秒間沈め、ふくれ及びミーズリングの発生の有無を肉眼にて観察した。
表中の各記号は、○:変化なし、△:ミーズリングまたは目浮き発生、×:ふくれ発生を意味する。
ガラス転移温度(Ｔｇ)：ＪＩＳ−Ｃ−６４８１に規定されるＴＭＡ法に従って測定した。なお、昇温速度１０℃／分で試料がガラス転移温度以上になるまで加熱し、一旦室温まで冷却してから再度昇温速度１０℃／分で昇温したときの寸法変化量を測定し、温度−寸法カーブからガラス転移温度を求めた。
得られた積層板の特性を表２に示す。
【００２１】
【表２】

表２に示す結果から明らかなように、本発明により、ハロゲンやアンチモン化合物をを実質的に含まないで難燃性ＵＬ９４Ｖ−０達成可能であることが確認できた。また、エポキシ樹脂がオキサゾリン環を分子骨格に含むエポキシ樹脂、またはジシクロペンタジエン型エポキシ樹脂が外形打ち抜き加工時に発生する層間剥離を抑えられることが確認できた。
【００２２】
【発明の効果】
本発明によれば、ハロゲンやアンチモン化合物を配合することなく難燃性ＵＬ９４Ｖ−０を達成する材料の提供が可能である。また、外形打ち抜き加工時に発生する層間剥離を抑制した積層板の提供が可能となった。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an epoxy resin composition suitable for an insulating material for an electric wiring board, in particular, an insulating material for a glass-based epoxy resin electric wiring board, and an electric wiring board laminate using the same.
[0002]
[Prior art]
In recent years, the types of electronic devices have been steadily expanding, and not only computer-related but also automatic control devices, communication devices, office devices, and the like are desired to be reduced in size and weight. Printed wiring boards used in these devices are mainly composed of 4 to 10 layers. In order to cope with high-density mounting, not only fine patterning but also thinning is achieved.
Items required for this printed wiring board include moisture absorption heat resistance and reliability. Therefore, the resin used for the printed wiring board also needs high Tg, high heat resistance, and low water absorption. In order to meet this requirement, improvements in epoxy resins, polyimide resins, isocyanate resins and the like are used.
These electrical insulating materials are required to have high flame resistance from the viewpoint of safety, as represented by insulating materials for glass-based epoxy resin electrical wiring boards. Halogen flame retardants, antimony compounds, or phosphorus-based flame retardants are required. Flame retardants have been used in combination with flame retardants.
However, in recent years, there has been an increase in the regulation of substances used due to environmental pollution and toxicity. In particular, the toxicity and carcinogenicity of organic halogen substances such as dioxin have become problems, and the reduction and reduction of halogen-containing substances has become a problem. There is a strong demand. In addition, antimony compounds are also demanded for reduction and reduction due to the carcinogenicity of antimony.
[0003]
[Problems to be solved by the invention]
This invention is made | formed in view of this condition, and provides the material which achieves the flame-retardant specification UL94V-0 substantially without containing a halogen and an antimony compound. Furthermore, since the resin having a benzoxazine ring has a rigid skeleton and lacks toughness, there has been a problem that delamination is likely to occur at the time of external punching, but the present invention solves such a problem. It was made.
[0004]
[Means for Solving the Problems]
As a result of intensive studies to achieve the above object, the present inventors have conducted polycondensation of a thermosetting resin comprising a compound having an epoxy resin and a dihydrobenzoxazine ring, a compound having a phenol, a triazine ring, and an aldehyde. It has been found that the above-mentioned problem can be achieved by adding 5 to 250 parts by weight of an inorganic filler to 100 parts by weight of a modified epoxy resin comprising a product. In particular, the present inventors have found that an epoxy resin containing an oxazolidinone ring in the molecular skeleton or a dicyclopentadiene type epoxy resin can suppress delamination that occurs during external punching.
That is, the present invention comprises (a) an epoxy resin, (b) a thermosetting resin comprising a compound having a dihydrobenzoxazine ring, (c) a polycondensate of a compound having a phenol and a triazine ring and an aldehyde. The present invention relates to a thermosetting resin composition obtained by adding 5 to 250 parts by weight of an inorganic filler to 100 parts by weight of a modified epoxy resin contained as an essential component, and a laminate for an electric wiring board using the same.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Examples of the epoxy resin (a) used in the present invention include bisphenol A type epoxy, bisphenol F type epoxy, phenol novolac type epoxy, bisphenol A novolac type epoxy, cresol novolac type epoxy, cycloaliphatic epoxy, heterocyclic epoxy, dioxygen. Glycidyl ester-based epoxy and the like can be mentioned, and there is no particular limitation. The glycidyl ester-based epoxy can be selected according to the purpose of use such as adding alone or several kinds.
In particular, when an epoxy resin containing a oxazolidinone ring in the molecular skeleton or a dicyclopentadiene type epoxy resin is used, it is possible to reduce delamination that occurs during the external punching process.
The epoxy resin containing an oxazolidinone ring in the molecular skeleton is an epoxy resin having a structure represented by the formula (1). (In the formula, R is a structure obtained by removing isocyanate groups from various polyfunctional isocyanate compounds. Average n = 0 to 2 positive numbers)
[0006]
[Chemical 1]

The isocyanate compounds used are bifunctional and polyfunctional isocyanate compounds such as polymethylene / polyphenyl / polyisocyanate, tolylene diisocyanate, naphthylene-1,5-diisocyanate and their multimers, blocked isocyanates masked with alcohol and phenol, and Although a urethane compound etc. are mentioned, it is not limited to these, Moreover, the isocyanate compound to be used may combine 2 or more types. A bifunctional isocyanate compound is preferred, because storage stability is lowered when the number of functional groups is too large.
The dicyclopentadiene type epoxy resin is an epoxy resin having a dicyclopentadiene skeleton in the molecule, and is an epoxy resin represented by the formula (2).
[Chemical 2]

Epoxy resins containing an oxazoline ring in the molecular skeleton are commercially available from Asahi Ciba Co., Ltd., and dicyclopentadiene type epoxy resins are commercially available from Dainippon Ink Co., Ltd.
[0007]
The thermosetting resin (b) having a dihydrobenzoxazine ring is not particularly limited as long as the resin has a dihydrobenzoxazine ring and is cured by a ring-opening reaction of the dihydrobenzoxazine ring. It is synthesized by the following formula from a compound having a formula, formalin and a primary amine.
[Chemical 3]

(In the formula, R1 is an alkyl group, a cyclohexyl group, a phenyl group, or a phenyl group substituted with an alkyl group or an alkoxyl group.)
[0008]
Examples of the compound having a phenolic hydroxyl group include polyfunctional phenols, biphenol compounds, bisphenol compounds, trisphenol compounds, tetraphenol compounds, and phenol resins. Examples of the polyfunctional phenol include catechol, hydroquinone, and resorcinol. Examples of the bisphenol compound include bisphenol A, bisphenol F and its positional isomer, bisphenol S, and tetrafluorobisphenol A. Examples of the phenol resin include resole resin, phenol novolac resin, phenol-modified xylene resin, alkylphenol resin, melamine phenol resin, benzoguanamine phenol resin, and phenol-modified polybutadiene.
Specific examples of the primary amine include methylamine, cyclohexylamine, aniline, and substituted aniline.
The thermosetting resin having a dihydrobenzoxazine ring is prepared by adding an equimolar mixture of a compound having a phenolic hydroxyl group and a primary amine to formaldehyde heated to 70 ° C. or higher, and 70 to 110 ° C., preferably 90 to 100 ° C. It can be synthesized by reacting at 20 ° C. for 20 to 120 minutes and then drying under reduced pressure at a temperature of 120 ° C. or lower.
[0009]
Examples of the phenols used for obtaining the modified phenol resin (c), which is a polycondensate of the phenols of the present invention with a compound having a triazine ring and aldehydes, include phenol, bisphenol A, bisphenol F, and bisphenol S. Examples thereof include polyhydric phenols, alkylphenols such as cresol, xylenol, ethylphenol, and butylphenol, aminophenol, and phenylphenol, which can be used alone or in combination of two or more. A combination of phenol and bisphenol A or a combination of phenol and alkylphenol is preferable. In this case, the reactivity is suppressed and the moldability is excellent as compared with the case where phenol is used alone, and the flame retardancy is more preferable than the case where bisphenol A or alkylphenol is used alone.
Examples of the compound having a triazine ring include guanamine derivatives such as melamine, benzoguanamine, and acetoguanamine, cyanuric acid or methyl cyanurate, cyanuric acid derivatives such as ethyl cyanurate, isocyanuric acid or methyl isocyanurate, and ethyl cyanurate. And isocyanuric acid derivatives. Preferably, heat resistance and flame retardancy are good, and low-priced melamine is suitable. The type and amount of compounds having a triazine ring are selected according to the purpose, and the nitrogen content is adjusted to achieve flame retardancy and reactivity. The heat resistance can be optimized.
Examples of aldehydes include formaldehyde, paraformaldehyde, trioxane, tetraoxymethylene and the like, but are not limited to these, but formaldehyde is preferable from the viewpoint of ease of handling, and formalin and paraformaldehyde are particularly preferable.
[0010]
As a method for synthesizing the modified phenolic resin used in the present invention, first, phenols, aldehydes, and a compound having a triazine ring are reacted by basic or acidic catalysis. At this time, the pH of the system is not particularly limited, but since most of the compounds containing a triazine ring are easily dissolved in a basic solution, it is preferably reacted under a basic catalyst. Is preferred. The reaction order of each raw material is also not particularly limited. Even if a compound having a triazine ring is added after first reacting phenols and aldehydes, the compound having a triazine ring is reacted with aldehydes and then phenol. In addition, all the raw materials may be added and reacted at the same time.
At this time, the molar ratio of the aldehydes to the phenols is not particularly limited, but is 0.2 to 1.5, preferably 0.4 to 0.8. Moreover, the weight ratio with the compound which has a triazine ring with respect to phenols is 10-98: 90-2, Preferably it is 50-95: 50-5. When the weight ratio of phenols is less than 10%, it becomes difficult to form a resin, and when it exceeds 98%, a sufficient flame-retardant effect cannot be obtained. Further, although not particularly limited as a catalyst, representative examples include hydroxides of alkali metals and alkaline earth metals such as sodium hydroxide, potassium hydroxide and barium hydroxide, and oxides thereof, ammonia, 1 to There are tertiary amines, hexamethylenetetramine, sodium carbonate and the like, inorganic acids such as hydrochloric acid, sulfuric acid and sulfonic acid, organic acids such as oxalic acid and acetic acid, Lewis acids, and divalent metal salts such as zinc acetate.
Since it is not preferable that inorganic substances such as metals remain as catalyst residues, it is preferable to use amines as basic catalysts and organic acids as acidic catalysts. The added amount of the catalyst is 0.1 to 1 part by weight with respect to 100 parts by weight of phenol.
[0011]
From the viewpoint of reaction control, the reaction may be carried out in the presence of various solvents such as methyl ethyl ketone. Next, neutralization and washing with water as necessary remove impurities such as salts. However, it is preferable not to carry out when amines are used for the catalyst. The reaction is carried out at 70 to 90 ° C. for 2 to 4 hours. After the reaction is completed, unreacted aldehydes, phenols, solvents and the like are removed according to a conventional method such as atmospheric distillation or vacuum distillation. At this time, it is preferable to remove unreacted aldehydes and methylols, and in order to obtain a resin composition substantially free of unreacted aldehydes and methylol groups, additional heat treatment at 120 ° C. or more is performed. There is a need to. At this time, it is preferable to sufficiently heat and distill in accordance with a conventional method for obtaining a novolac resin. Although not particularly limited, it is preferable that the unreacted functional phenol monomer be 2% or less.
Furthermore, by combining several kinds of the modified phenolic resin of the present invention or using it as a curing agent in combination with other novolac resins of phenols, it is possible to obtain moldability, flame retardancy and heat resistance that cannot be obtained alone. It is possible and may be used in combination according to the purpose.
[0012]
As additives, inorganic fillers such as aluminum hydroxide, magnesium hydroxide, inorganic hydrates such as zeolite and hydrotalcite, clay, talc, wollastonite, mica, calcium carbonate, magnesium carbonate, alumina, silica, glass General-purpose inorganic fillers such as powder, B and Sn-based fillers such as zinc borate, zinc stannate and zinc hydroxystannate, metal oxides such as zinc oxide and tin oxide, or inorganic phosphorus such as red phosphorus System materials and nitrates such as copper and zinc can be used without limitation, and these inorganic fillers can be used by coating or treating them with silane coupling agents or titanate coupling agents. Adhesiveness with components, heat resistance, stability against temperature and humidity and safety are preferred.
[0013]
In order to achieve the target flame retardancy using only non-halogen materials, the content of triazine ring in the epoxy resin composition of the present invention, that is, the N content effective for flame retardancy is From the amount of N contained in the polycondensate of a compound having a benzoxazine ring, a phenol, a compound having a triazine ring, and an aldehyde, the limit is about 5% by weight in the solid content of the resin. -1 or UL94V-0 cannot be achieved unless other characteristics and moldability are ignored and a special epoxy resin is used or the phenol resin composition is extremely increased. Therefore, in order to achieve flame retardancy UL94V-1 or UL94V-0, a flame retardancy assisting action by an additive is required. Therefore, it is preferable to add 5 parts by weight or more of an inorganic filler with respect to 100 parts by weight of the modified epoxy resin to reduce the abundance of the flammable substance. Furthermore, in order to achieve flame retardancy UL94V-0, the inorganic filler As an inorganic hydrate, it is preferable to use 30 parts by weight or more.
However, if the added weight of the inorganic filler exceeds 250 parts by weight, the resulting epoxy resin composition has a marked decrease in adhesion to the metal foil, and at the same time, heat resistance, workability, insulation, etc. cannot be achieved. In addition, 250 parts by weight or less is preferable because it becomes impossible to form without defects when performing composite molding with a nonwoven fabric or a woven fabric substrate.
In addition to these components, a colorant, an antioxidant, a reducing agent, an ultraviolet opaque agent and the like can be blended as necessary.
[0014]
The base material of the woven fabric and the nonwoven fabric used when preparing the prepreg using the above resin composition is a natural fiber base material such as paper and cotton linter, organic synthesis such as aramid, polyvinyl alcohol, polyester and acrylic. Inorganic fiber substrates such as fiber substrates, glass and asbestos are used. From the viewpoint of flame resistance, a glass fiber substrate is preferred. Glass fiber base materials include woven fabrics using E glass, C glass, D glass, S glass, etc., glass nonwoven fabrics obtained by bonding short fibers with an organic binder, and those obtained by mixing glass fibers and cellulose fibers. .
The varnish blended with these is impregnated into a base material such as a woven fabric or a non-woven fabric to produce a prepreg, and after laying the prepreg together and forming a copper foil on both sides, pressurizing and hot pressing, A copper-clad laminate can be produced.
[0015]
The present invention uses a compound having a dihydrobenzoxazine ring that has a large amount of aromatic components and is difficult to thermally decompose, and has excellent flame retardancy, and further has a triazine ring containing N as a curing agent to enhance flame retardancy. In order to use such a phenol resin composition, a large amount of N is incorporated into the molecular structure in a stable state, and an inorganic substance is added and used together as an additive having an effect of enhancing flame retardancy. The combination of flame retardants with different operating temperature ranges makes it possible to obtain a synergistic effect compared to the case where each flame retardant is used alone, and is stable, flame retardant, and an epoxy resin composition with an excellent balance of other properties. It is possible to obtain
Furthermore, the epoxy resin containing an oxazolidinone ring as shown in the formula (1) has an excellent oxazoline ring having excellent heat resistance and flame retardancy, flexibility and heat resistance, and an average n = 0. Since there are few OH groups at the reactive site with ˜2, it has both flexibility and toughness, and is effective in reducing delamination at the time of external punching. In addition, by using dicyclopentadiene type epoxy, adhesion between layers is improved, and there is an effect in reducing delamination at the time of external punching.
[0016]
【Example】
EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Hereinafter, “parts” represents “parts by weight” and “%” represents “% by weight”.
Reference Example 1, Example 2, Reference Example 3, Example 4 and Example 5 , Comparative Examples 1-2 [1] Synthesis of resin having dihydrobenzoxazine ring (1) Synthesis of phenol novolac 1.9 Kg of phenol, formalin (37% aqueous solution) 1.15 Kg and oxalic acid 4 g were charged into a 5 liter flask and reacted at reflux temperature for 6 hours. Subsequently, the internal pressure was reduced to 6666.1 Pa or less to remove unreacted phenol and water. The obtained resin had a softening point of 89 ° C. (ring and ball method), 3 or more nuclei / 2/2 nuclei ratio = 89/11 (peak area ratio by gel permeation chromatography). Hereinafter, the obtained resin is abbreviated as (A1).
(2) Introduction of dihydrobenzoxazine ring Phenol novolak resin (1.7 kg) (hydroxyl group: 16 mol) synthesized as described above was stirred with aniline (1.49 kg, 16 mol) at 80 ° C. for 5 hours to prepare a uniform mixed solution. Into a 5 liter flask, 1.62 kg of formalin was charged and heated to 90 ° C., and the mixed solution of henovolak / aniline was added little by little over 30 minutes. After completion of the addition, the temperature is maintained at the reflux temperature for 30 minutes. After that, the condensed water is removed by reducing the pressure to 6666.1 Pa or less at 100 ° C. for 2 hours, and thermosetting in which 95% of the reactive hydroxyl groups are dihydrobenzoxazine converted. A functional resin was obtained. Hereinafter, the obtained resin is abbreviated as (B1).
[0017]
[2] Synthesis Example of Modified Phenol Resin Composition 29 parts of 41.5% formalin and 0.47 part of triethylamine were added to 94 parts of phenol and reacted at 80 ° C. for 3 hours. After adding 19 parts of melamine and further reacting for 1 hour, the temperature was raised to 120 ° C. while removing water under normal pressure, and the reaction was continued for 2 hours while maintaining the temperature. Next, the temperature was raised to 180 ° C. while removing water under normal pressure, unreacted phenol was removed under reduced pressure, and a phenol resin composition that was a reaction product of phenol and melamine having a softening point of 136 ° C. was obtained. . Hereinafter, the obtained resin is abbreviated as (C1).
The weight ratio of phenol and melamine, the amount of unreacted formaldehyde, the presence or absence of methylol groups, and the amount of unreacted phenol monomer were determined and the results are shown in Table 1.
[Table 1]

[0018]
[3] Other compounds Epoxy resin (a) Phenol novolac type epoxy resin (trade name, manufactured by DEN430 Dow Chemical Co., Ltd.)
Epoxy equivalent 170-180 g / eq, liquid at room temperature (b) Epoxy resin containing oxazolidinone ring (AER4152 manufactured by Asahi Ciba Co., Ltd.)
Epoxy equivalent 330-360 g / eq, Isocyanate compound: Tolylene diisocyanate n = 0.15-0.25
(C) Dicyclopentadiene type epoxy resin (EVA-7200H, trade name, manufactured by Dainippon Ink Co., Ltd.)
Epoxy equivalent 280-290 g / eq
Inorganic filler, aluminum hydroxide (CL-303 Sumitomo Chemical Co., Ltd. trade name)
Those having a small amount of residual ions or the like generally used for electronic materials and having a particle size of 3 to 5 μm were used.
[0019]
[4] Production of Laminate A resin composition having a solid content shown in Table 2 was dissolved in methyl ethyl ketone, and the solution was adjusted with methyl ethyl ketone so that the nonvolatile content of the solution was 65 to 75%. Thereafter, each mixed solution was impregnated into glass cloth (0.2 mm thickness) and dried at 160 ° C. for 4 minutes to obtain a prepreg. Eight prepregs were stacked, 18 μm copper foils were stacked on both sides thereof, and heated and pressed at 180 ° C. under a pressure of 4 MPa for 100 minutes to obtain a 1.6 mm thick double-sided copper-clad laminate.
[0020]
The double-sided copper foil-clad laminate produced as described above was examined for the amount of delamination generated at the time of external punching, flame resistance, moisture resistance, and Tg. The results are shown in Table 2.
The test method was as follows.
Delamination amount generated during external punching: The copper foil of the produced double-sided copper-clad laminate was removed by etching, and a sample was used to determine the delamination amount using a DIN mold.
Combustion resistance: Conforms to UL94.
Solder heat resistance: 121 ° C., 2130 hPa pressure cooker processing specimen held for 6 hours (with 50 mm × 50 mm single-sided copper) submerged in a solder bath heated to 260 ° C. for 30 seconds, blistering and melting The presence or absence of the ring was observed with the naked eye.
Each symbol in the table means ◯: no change, △: occurrence of messling or floating eyes, and x: occurrence of blistering.
Glass transition temperature (Tg): Measured according to the TMA method defined in JIS-C-6481. In addition, the sample was heated at a heating rate of 10 ° C / min until the glass transition temperature or higher, and after cooling to room temperature, the dimensional change when the temperature was raised again at a heating rate of 10 ° C / min was measured. The glass transition temperature was determined from the temperature-dimension curve.
Table 2 shows the characteristics of the obtained laminate.
[0021]
[Table 2]

As is apparent from the results shown in Table 2, it was confirmed that the present invention can achieve flame retardancy UL94V-0 without substantially containing a halogen or an antimony compound. It was also confirmed that the epoxy resin containing an oxazoline ring in the molecular skeleton or the dicyclopentadiene type epoxy resin can suppress delamination that occurs during the external punching process.
[0022]
【The invention's effect】
According to the present invention, it is possible to provide a material that achieves flame retardancy UL94V-0 without blending a halogen or an antimony compound. In addition, it has become possible to provide a laminate that suppresses delamination that occurs during external punching.

Claims (4)

(A) an epoxy resin containing an oxazolidinone ring in the skeleton , (b) a thermosetting resin comprising a compound having a dihydrobenzoxazine ring, (c) a polycondensate of a compound having a phenol and a triazine ring and an aldehyde A thermosetting resin composition obtained by adding 5 to 250 parts by weight of an inorganic filler to 100 parts by weight of a modified epoxy resin composition containing as an essential component. All materials are halogen and antimony compound The thermosetting resin composition of claim 1 Symbol placement are those that does not contain the use. Prepreg comprising the claims 1 or 2 thermosetting resin composition according to impregnate dry fiber substrate. The laminated board for electrical wiring boards obtained by laminating | stacking metal foil on the single side | surface or both surfaces of the prepreg of Claim 3 , and heat-press-molding.