JP4499345B2 - Organophosphorus compound-containing resin composition, prepreg, laminate and multilayer printed board using the resin composition - Google Patents

Description

（式中、Ｒは置換基を有していてもよい炭化水素骨格を、Ｒ²，Ｒ³，Ｒ⁴は異なってもよい水素原子または炭素数１〜６の炭化水素基を、Ｒ⁵，Ｒ⁶，Ｒ⁷，Ｒ⁸は異なってもよい水素原子または炭素数１から２０の炭化水素基を、ｎは２以上の整数を表す）で示される多官能のスチレン基を有し、重量平均分子量１０００以下の架橋成分を含有する有機燐化合物含有樹脂組成物である。
【００２１】
本発明に用いられる有機燐化合物は、特に制限はなく、例えば、トリフェニルフォスフェート，トリクレジルホスフェート，トリキシレニルホスフェート等の燐酸エステル，縮合燐酸エステルである。こうした市販品としては、大八化学製のＰＸ−２００，ＰＸ−２０１，ＰＸ−２０２，ＣＲ−７４１Ｃ等が使用できる。各種有機燐化合物の中でも、特に、常温で固体の有機燐化合物を用いることが好ましい。これにより誘電正接の増加を抑制することができる。
【００２２】
有機隣化合物の添加量は、樹脂組成物中の樹脂成分の総量を１００重量部とし、燐成分（燐原子）の添加量が１.５〜５重量部となるように添加することが好ましい。本範囲で十分な難燃性を得ることができる。
【００２３】
有機燐化合物の添加量が上記の範囲より低いと十分な難燃性が得られない場合があり、また、多過ぎると機械強度の低下を招く場合がある。
【００２４】
本発明の有機燐化合物含有樹脂組成物では、更に、高分子量体を添加することによって該樹脂組成物に成膜性，強度，伸び，接着性を付与することができる。
【００２５】
こうした高分子量体の例としてはブタジエン，イソプレン，スチレン，メチルスチレン，エチルスチレン，ジビニルベンゼン，アクリル酸エステル，アクリロニトリル，Ｎ−フェニルマレイミドおよびＮ−ビニルフェニルマレイミドの少なくとも一種からなる重合体、置換基を有していてもよいポリフェニレンオキサイド、並びに、脂環式構造を有するポリオレフィン等が挙げられる。
【００２６】
上記高分子量体の添加量には特に制限はないが、架橋成分が５〜９５重量部，高分子量体が９５〜５重量部の範囲で添加するのが好ましい。上記の範囲内で強度、伸び，接着力の向上等、目的に応じて樹脂組成を調整することができる。特に、好ましい範囲としては架橋成分が５０〜８０重量部、高分子量体が５０〜２０重量部の範囲で、これにより高分子量体が架橋性の官能基を有していない場合にも耐溶剤性を保持することができる。
【００２７】
更に、本発明の有機燐化合物含有樹脂組成物には、スチレン基を重合し得る硬化触媒、または、スチレン基の重合を抑制し得る重合禁止剤を添加することにより硬化性の向上、保存安定性の向上を図ることができる。
【００２８】
本発明に用いられる多官能スチレン化合物は、硬化触媒を添加しなくとも硬化することができるが、硬化触媒を添加することによって、多官能スチレン化合物の硬化を促進することができる。これにより低温での硬化が可能となる。その添加量は誘電率，誘電正接に影響を与えない範囲に設定することが好ましく、樹脂組成物中の樹脂成分の総量を１００重量部として０.０００５〜１０重量部とすることが望ましい。
【００２９】
スチレン基の重合を開始し得るカチオンまたはラジカル活性種を、熱または光によって生成する硬化触媒の例を以下に示す。
【００３０】
カチオン重合開始剤としては、ＢＦ₄、ＰＦ₆、ＡｓＦ₆、ＳｂＦ₆を対アニオンとするジアリルヨードニウム塩，トリアリルスルホニウム塩および脂肪族スルホニウム塩が挙げられ、こうした市販品としては旭電化工業製ＳＰ−７０，１７２，ＣＰ−６６、日本曹達製ＣＩ−２８５５，２８２３、三新化学工業製ＳＩ−１００ＬおよびＳＩ−１５０Ｌ等を使用することができる。
【００３１】
ラジカル重合開始剤としては、ベンゾインまたはベンゾインメチルのようなベンゾイン系化合物、アセトフェノンまたは２,２−ジメトキシ−２−フェニルアセトフェノンのようなアセトフェノン系化合物、チオキサントンまたは２,４−ジエチルチオキサントンのようなチオキサンソン系化合物、４,４'−ジアジドカルコン、２,６−ビス（４'−アジドベンザル）シクロヘキサノンまたは４,４'−ジアジドベンゾフェノンのようなビスアジド化合物、アゾビスイソブチルニトリル、２、２−アゾビスプロパン、ｍ,ｍ'−アゾキシスチレンまたはヒドラゾンのようなアゾ化合物、並びに、２,５−ジメチル−２,５−ジ（ｔ−ブチルパーオキシ）ヘキサンまたは２,５−ジメチル−２,５−ジ（ｔ−ブチルパーオキシ）ヘキシン−３、ジクミルパーオキシドのような有機過酸化物等が挙げられる。
【００３２】
特に、官能基を持たない化合物の水素引き抜きを生じさせ、架橋成分と高分子量体間の架橋をもたらし得る有機過酸化物またはビスアジド化合物を添加することが望ましい。
【００３３】
前記の重合禁止剤は、本発明の有機燐化合物含有樹脂組成物の保存安定性を増す作用を有するものである。その添加量は誘電特性、硬化時の反応性を著しく阻害しない範囲が好ましく、樹脂組成物中の樹脂成分の総量１００重量部に対し、０.０００５〜５重量部とすることが望ましい。重合禁止剤を前記範囲で添加すると、保存時の余計な架橋反応を抑制することができ、また、硬化時に著しい硬化障害をもたらすこともない。
【００３４】
かかる重合禁止剤としてはハイドロキノン，ｐ−ベンゾキノン，クロラニル，トリメチルキノン，４−ｔ−ブチルピロカテコール等のキノン類および芳香族ジオール類が挙げられる。
【００３５】
本発明の有機燐化合物含有樹脂組成物は、有機または無機のクロスまたは不織布基材に含浸，乾燥させることによりプリプレグとして用いる。なお、プリプレグの基材については特に制限はなく、各種ガラスクロス，ガラス不織布，アラミド不織布または多孔質ＰＴＦＥフィルム等を用いることができる。プリプレグは、樹脂組成物を用いて作製したワニスに、基材となるクロスまたは不織布を浸し、次いでこれを乾燥することにより作製できる。含浸後の乾燥条件は用いる樹脂組成物によるが、例えば、溶媒としてトルエンを使用した場合は８０〜１３０℃で３０〜９０分程度乾燥するのが好ましい。
【００３６】
本発明のプリプレグに電解銅箔等の導体箔を重ね、加熱プレス加工することによって、表面に導体層を有する積層板を作製することができる。銅箔の厚さは、１２〜３６μｍ程度が好ましい。加圧プレス加工の条件は、使用する樹脂組成物にもよるが、例えば、高分子量体としてポリフェニレンエーテルを使用した場合には１５０〜２４０℃，１〜５ＭＰａで１〜３時間成形するのが好ましい。
【００３７】
上記の積層板の導体層を通常のエッチング法によって配線加工し、これを前記プリプレグを介して複数積層し、加熱プレス加工することによって多層プリント基板を作製する。こうして得られた多層プリント基板は誘電率，誘電正接が低く、難燃性を有する。即ち、伝送特性と安全性に優れた多層プリント基板となる。
【００３８】
【発明の実施の形態】
以下に実施例および比較例を示して本発明を具体的に説明する。なお、以下の説明中に部とあるのは、特に断りのない限り重量部を指す。表１，２に本発明の実施例と比較例の組成とその特性を示す。
【００３９】
以下に実施例および比較例に使用した試薬の名称、合成方法、ワニスの調製法および硬化物の評価方法を説明する。
【００４０】
（１） １,２−ビス（ビニルフェニル）エタン（以下、ＢＶＰＥと呼ぶ）の合成
５００ｍｌの三つ口フラスコにグリニャール反応用粒状マグネシウム（関東化学製）５.３６ｇ（２２０ｍｍｏｌ）を採り、滴下ロート、窒素導入管およびセプタムキャップを取り付けた。窒素気流下、スターラによってマグネシウム粒を攪拌しながら、系全体をドライヤーで加熱脱水した。
【００４１】
次ぎに、乾燥テトラヒドロフラン３００ｍｌをシリンジに採り、セプタムキャップを通じて注入した。溶液を−５℃に冷却後、滴下ロートを用いてビニルベンジルクロライド（ＶＢＣ、東京化成製）３０.５ｇ（２００ｍｍｏｌ）を約４時間かけて滴下した。滴下終了後、０℃で２０時間攪拌を続けた。反応終了後、反応溶液をろ過して残存マグネシウムを除き、エバポレーターで濃縮した。
【００４２】
濃縮溶液をヘキサンで希釈し、３.６％塩酸水溶液で１回、純水で３回洗浄し、次いで硫酸マグネシウムで脱水した。
【００４３】
脱水溶液をシリカゲル（和光純薬製ワコーゲルＣ３００）／ヘキサンのショートカラムに通して精製し、真空乾燥してＢＶＰＥを得た。得られたＢＶＰＥはｍ−ｍ体（液状）、ｍ−ｐ体（液状）、ｐ−ｐ体（結晶）の混合物であり、収率は９０％であった。
【００４４】
¹Ｈ−ＮＭＲによってその構造を調べたところ、その値は文献値と一致した（６Ｈ−ビニル：α−２Ｈ、６.７ｐｐｍ、β−４Ｈ、５.７〜５.２ｐｐｍ、８Ｈ−アロマティック：７.１〜７.３５ｐｐｍ、４Ｈ−メチレン：２.９ｐｐｍ）。このＢＶＰＥを架橋成分として用いた。
【００４５】
（２） その他の試薬
高分子量体：アルドリッチ製、ポリー２，６−ジメチルー１，４−フェニレンオキシド（ＰＰＥ）
難燃剤ＰＸ−２００：大八化学工業(株）製１，３フェニレンビス（ジ２，６キシレニルホスフェート）
ＨＣＡ−ＨＱ：三光（株）製１０−（２，５−ジヒドロキシフェニル）−１０Ｈ−９−オキサー１０−ホスホフェナントレン−１０−オキシド
硬化触媒：２５Ｂ：日本油脂製、２，５−ジメチルー２，５−ビス（ｔ−ブチルパーオキシ）ヘキシン−３
（３） ワニスの調整法
所定量の高分子量体、架橋成分、クロロホルムおよび有機燐化合物をボールミルにて約８時間攪拌して溶解、分散して、樹脂組成物のワニスを作製した。
【００４６】
（４） 樹脂板の作製
上記ワニスをＰＥＴフィルムに塗布して乾燥した後、これを剥離してポリテトラフルオロエチレン製のスペーサ内に所定量入れ、ポリイミドフィルムおよび鏡板を介し、真空下で、加熱，加圧して硬化して樹脂板を得た。加熱条件は、１２０℃／３０分、１５０℃／３０分、１８０℃／１００分で、プレス圧力１.５ＭＰａの多段階加熱とした。樹脂板の大きさは７０ｍｍ×７０ｍｍ×１.５ｍｍとした。
【００４７】
（５） プリプレグの作製
各実施例において作製したプリプレグは、当該ワニスをガラスクロス（日東紡製＃２１１６）に含浸し、室温で約１時間、９０℃で６０分間乾燥することにより作製した。
【００４８】
（６） プリプレグ硬化物の作製
積層板とした際の特性を知るため、前記で作製したプリプレグを１０枚重ねて真空下で加熱，加圧して模擬基板を作製した。加熱条件は１２０℃／３０分、１５０℃／３０分、１８０℃／１００分、プレス圧力１.５ＭＰａの多段階加熱とした。模擬基板は７０ｍｍ×７０ｍｍ×１.５ｍｍとした。
【００４９】
（７） 誘電率および誘電正接の測定
誘電率，誘電正接は、空胴共振器摂動法（アジレントテクノロジー製８７２２ＥＳ型ネットワークアナライザー、関東電子応用開発製空胴共振器）によって、１０ＧＨｚでの値を測定した。
【００５０】
（８） 難燃性
難燃性は、サンプルサイズ７０ｍｍ×３ｍｍ×１.５ｍｍの試料を用いてＵＬ−９４規格に基づき評価し、平均燃焼時間と最大燃焼時間を測定した。
【００５１】
〔比較例１〕
比較例１は、有機燐化合物を添加していない樹脂組成物から作製した樹脂板である。誘電特性は優れているものの、難燃剤を含んでいないため難燃性を有していなかった。
【００５２】
〔実施例１〜３〕
実施例１〜３は、比較例１の樹脂組成物に、有機燐化合物として常温で固形のＰＸ−２００を添加量を変えて添加した例である。その評価結果を表１に示した。
【００５３】
燐成分の含有率が増すに伴い燃焼時間が短くなり、有機燐化合物の添加により難燃性が増すことが確認された。燐含有率が１.５ｗｔ％を超えると、ほぼＶ−０相当の難燃性が達成された。この時、誘電率は２.５０から２.５２に僅かに増加したものの、誘電正接の値は０.００２２から０.００１９に低下した。これにより優れた誘電特性を有する難燃性樹脂組成物が得られた。
【００５４】
【表１】

〔実施例４〜６〕
実施例４〜６は比較例１の樹脂組成物に、有機燐化合物として常温で固形のＨＣＡ-ＨＱを添加量を変えて添加したものである。その評価結果を表２に示した。
【００５５】
燐成分の含有率が増すに伴い燃焼時間が短くなり、有機燐化合物の添加により難燃性が増すことが確認された。燐含有率が１.６ｗｔ％を超えると、ほぼＶ−０が達成された。この時、誘電率は２.５０から２.５８に僅かに増加したものの、誘電正接の値は０.００２２であり変化しなかった。これにより優れた誘電特性を有する難燃性樹脂組成物が得られた。
【００５６】
【表２】

〔実施例７〕
実施例３の組成のワニスを用いてプリプレグを作製した。作製したプリプレグはタックフリー性を有していた。本プリプレグを１０枚重ね合わせて真空下、加熱，加圧してプリプレグ硬化物を作製した。該プリプレグ硬化物の樹脂含有量は３６ｗｔ％で、難燃性試験を実施したところ平均燃焼時間は０.２秒、最大燃焼時間は０.３秒と、ほぼＶ−０相当の難燃性を達成した。また、誘電率は３.１０、誘電正接は０.００４であった。
【００５７】
該プリプレグに用いた樹脂組成物は優れた溶融流動性を有し、多層プリント基板の層間接着剤として好適に用いることができる。
【００５８】
〔実施例８〕
実施例７で作製したプリプレグの両面に電解銅箔の粗面を張り付け、真空下で、加圧，加熱して両面銅張積層板を作製した。加熱条件は１２０℃／３０分、１５０℃／３０分、１８０℃／１００分、プレス圧力１.５ＭＰａとした。銅箔とプリプレグは良好な接着性を示し、これにより低誘電損失の多層プリント基板の作製が可能となった。
【００５９】
〔実施例９〕
図１は、本発明の多層プリント基板の作成工程の一例示す模式断面図である。
【００６０】
（Ａ）では、実施例８と同様にして得た樹脂基板1の両面に銅箔2を有する両面銅張積層板の片面に、フォトレジスト３（日立化成製 ＨＳ４２５）をラミネートして全面に露光した。次いで、フォトレジスト３を貼っていない方の面にフォトレジスト３（日立化成製 ＨＳ４２５）をラミネートしてテストパターンを露光し、未露光部分のフォトレジストを１％炭酸ナトリウム液で現像した。
【００６１】
（Ｂ）では、硫酸５％，過酸化水素５％のエッチング液で露出した銅箔をエッチング除去して、両面銅張積層板の片面に導体配線を形成した。
【００６２】
（Ｃ）では、３％水酸化ナトリウム溶液で残存するフォトレジスト３を除去し、片面に配線を有する配線基板を得た。同様にして２枚の配線基板を作製した。
【００６３】
（Ｄ）では、二枚の配線基板の配線側の面に実施例７のプリプレグ４を挟み、真空下、加熱，加圧して多層化した。加熱条件は１２０℃／３０分、１５０℃／３０分、１８０℃／１００分、プレス圧力１.５ＭＰａの多段階加熱とした。
【００６４】
（Ｅ）では、作製した多層板の両面の外装銅にフォトレジスト３（日立化成製ＨＳ４２５）をラミネートしてテストパターンを露光し、未露光部分のフォトレジストを１％炭酸ナトリウム液で現像した。
【００６５】
（Ｆ）では、硫酸５％，過酸化水素５％のエッチング液で露出した銅箔をエッチング除去し、３％水酸化ナトリウム溶液で残存するフォトレジストを除去して外装配線６を形成した。
【００６６】
（Ｇ）では、内層配線５と外装配線６を接続するスルーホール７をドリル加工で形成した。
【００６７】
（Ｈ）では、配線基板をめっき触媒のコロイド溶液に浸して、スルーホール７内、および、基板表面に触媒８を付与した。
【００６８】
（Ｉ）では、めっき触媒８を活性化処理の後、無電解めっき液（日立化成製 ＣＵＳＴ２０００）により、約１μｍの種膜９を設けた。
【００６９】
（Ｊ）では、フォトレジスト（日立化成製 ＨＮ９２０）を配線基板の両面にラミネートした。
【００７０】
（Ｋ）では、スルーホール7部分および配線基板の端部をマスクして露光後、３％炭酸ナトリウムで現像して開孔部１０を設けた。
【００７１】
（Ｌ）では、配線基板の端部に電極１１を設け、電解めっきによってスルーホール7部分にめっき銅１２を約１８μｍ形成した。
【００７２】
（Ｍ）では、電極１１の部分を切断除去し、残存するフォトレジストを５％水酸化ナトリウム水溶液で除去した。
【００７３】
（Ｎ）では、硫酸５％，過酸化水素５％のエッチング液に配線基板を浸し、約１μｍエッチングして種膜を除去して多層配線板を作製した。得られた多層配線板は低誘電率，低誘電正接で、かつ、高い難燃性を示した。
【００７４】
【発明の効果】
本発明によれば、誘電率、誘電正接が低く、難燃性の硬化物を与える樹脂組成物が得られる。
【００７５】
本樹脂組成物は、高周波用電気部品の絶縁材料に好適であり、高周波信号用多層プリント基板へ応用した場合、低誘電損失と難燃性を両立できると云う効果が得られる。
【図面の簡単な説明】
【図１】本発明の多層配線板の作製工程を示す模式断面図である。
【符号の説明】
１…樹脂基板、２…電解銅箔、３…フォトレジスト、４…プリプレグ、５…内層配線、６…外層配線、７…スルーホール、８…めっき触媒、９…種膜、１０…開孔部、１１…電極、１２…めっき銅。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a low-dielectric loss and flame-retardant low-dielectric loss tangent resin composition that supports high-frequency signals, a prepreg using the resin composition, a laminated board with a conductor layer, and a multilayer printed board.
[0002]
[Prior art]
In recent years, the signal band of information communication devices such as PHS and mobile phones, and the CPU clock time of computers have reached the GHz band, and the frequency has been increased.
[0003]
The dielectric loss of an electrical signal is proportional to the product of the square root of the dielectric constant of the insulator forming the circuit, the dielectric loss tangent and the frequency of the signal used. Therefore, the higher the frequency of the signal used, the greater the dielectric loss.
[0004]
Since the dielectric loss attenuates the electrical signal and impairs the reliability of the signal, it is necessary to select a material having a small dielectric constant and dielectric loss tangent for the insulator in order to suppress this. Removal of polar groups in the molecular structure is effective in reducing dielectric constant and dielectric loss tangent of insulators, such as fluorine resin, curable polyolefin, cyanate ester resin, curable polyphenylene oxide, allyl-modified polyphenylene ether, A polyetherimide modified with divinylbenzene or divinylnaphthalene has been proposed.
[0005]
For example, a fluororesin represented by polytetrafluoroethylene (PTFE) has a low dielectric constant and dielectric loss tangent, and is used as a substrate material that handles high-frequency signals.
[0006]
On the other hand, various non-fluorine-based low dielectric constant and low dielectric loss tangent resins that are soluble in organic solvents and easy to handle have been studied. For example, there is an example in which a glass cloth is impregnated with a diene polymer such as polybutadiene described in JP-A-8-208856 and cured with a peroxide.
[0007]
Further, there is an example of a cyclic polyolefin in which an epoxy group is introduced into a norbornene-based addition polymer described in JP-A-10-158337 to impart curability. There is an example in which a cyanate ester, a diene polymer and an epoxy resin described in JP-A-11-124491 are heated to form a B stage.
[0008]
Further, examples of modified resins comprising polyphenylene oxide, diene polymer and triallyl isocyanate described in JP-A-9-118759, resin compositions comprising allylated polyphenylene ether and triallyl isocyanate described in JP-A-9-246429, etc. There are examples of things.
[0009]
Further, there is an example in which polyetherimide described in JP-A-5-156159 and styrene, divinylbenzene or divinylnaphthalene are alloyed. Examples of the resin composition include a hydroquinone bis (vinylbenzyl) ether and a novolak phenol resin synthesized from a dihydroxy compound described in JP-A-5-78552 and a chloromethylstyrene by a Williamson reaction.
[0010]
On the other hand, the above-mentioned insulating material must be flame retardant from the viewpoint of the safety of the applied product. Conventionally, the addition of flame retardants such as red phosphorus, phosphoric acid esters, nitrogen-containing compounds, halides, metal hydrates, and metal oxides has been studied. For example, there is an example described in JP-A-4-117442 using a compound of a nitrogen compound such as melamine, a polyol and an organic phosphate.
[0011]
Also, examples described in JP-A-9-104721 using metal oxides, examples using metal hydrates and potassium titanate, examples of JP-A-2000-26553 using phosphorus compounds and nitrogen-containing compounds. There are many examples such as JP-A 2000-106041 using red phosphorus and metal hydrate, JP-A 6-106676 using halide.
[0012]
[Problems to be solved by the invention]
Even a material that has been made flame retardant using the above-described low dielectric constant and low dielectric loss tangent material does not have sufficient dielectric properties to cope with recent high frequency equipment.
[0013]
The object of the present invention is to achieve flame retardancy without impairing the low dielectric constant and low dielectric loss tangent of the low dielectric loss tangent resin composition containing a polyfunctional styrene compound having superior dielectric properties compared to conventional materials. The object is to provide an organic phosphorus compound-containing resin composition.
[0014]
Another object of the present invention is to provide a prepreg, a laminate and a multilayer printed board using the resin composition.
[0015]
[Means for Solving the Problems]
The cured product of the polyfunctional styrene compound has a very low dielectric constant and dielectric loss tangent, and the value is about 2.5 at a measurement frequency of 10 GHz and the dielectric loss tangent is less than 0.002.
[0016]
As a result of various investigations of flame retardants that impart flame retardancy to the cured resin composition without impairing this property, the required flame retardancy is exhibited when an organic phosphorus compound is added to the resin composition. Confirmed to do. In particular, by adding a solid organic phosphorus compound at room temperature, an increase in dielectric loss tangent can be suppressed and sufficient flame retardancy can be imparted.
[0017]
Moreover, the organophosphorus compound-containing resin composition of the present invention can be processed into prepregs, laminates, and multilayer printed boards.
[0018]
The organic phosphorus compound-containing resin composition of the present invention and the cured product thereof will be described.
[0019]
The resin composition of the present invention has the formula 1
[0020]
[Chemical formula 2]

(Wherein R represents a hydrocarbon skeleton which may have a substituent, R ² , R ³ and R ⁴ represent different hydrogen atoms or hydrocarbon groups having 1 to 6 carbon atoms, R ⁵ , R ⁶ , R ⁷ and R ⁸ each have a polyfunctional styrene group represented by a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and n represents an integer of 2 or more. An organic phosphorus compound-containing resin composition containing a crosslinking component having a molecular weight of 1000 or less.
[0021]
The organic phosphorus compound used in the present invention is not particularly limited, and examples thereof include phosphate esters such as triphenyl phosphate, tricresyl phosphate, and trixylenyl phosphate, and condensed phosphate esters. As such commercially available products, PX-200, PX-201, PX-202, CR-741C manufactured by Daihachi Chemical, etc. can be used. Among various organic phosphorus compounds, it is particularly preferable to use an organic phosphorus compound that is solid at room temperature. Thereby, an increase in dielectric loss tangent can be suppressed.
[0022]
The addition amount of the organic adjacent compound is preferably added so that the total amount of the resin component in the resin composition is 100 parts by weight and the addition amount of the phosphorus component (phosphorus atom) is 1.5 to 5 parts by weight. Sufficient flame retardancy can be obtained within this range.
[0023]
If the addition amount of the organic phosphorus compound is lower than the above range, sufficient flame retardancy may not be obtained, and if it is too much, mechanical strength may be lowered.
[0024]
In the organophosphorus compound-containing resin composition of the present invention, film formability, strength, elongation and adhesion can be imparted to the resin composition by adding a high molecular weight substance.
[0025]
Examples of such high molecular weight substances include butadiene, isoprene, styrene, methyl styrene, ethyl styrene, divinyl benzene, acrylic acid ester, acrylonitrile, N-phenyl maleimide, a polymer comprising at least one kind of N-vinyl phenyl maleimide, and a substituent. Examples thereof include polyphenylene oxide which may have, and polyolefin having an alicyclic structure.
[0026]
Although there is no restriction | limiting in particular in the addition amount of the said high molecular weight body, It is preferable to add a crosslinking component in 5-95 weight part and a high molecular weight body in the range of 95-5 weight part. Within the above range, the resin composition can be adjusted according to the purpose, such as improvement in strength, elongation and adhesion. In particular, as a preferable range, the crosslinking component is in the range of 50 to 80 parts by weight, and the high molecular weight is in the range of 50 to 20 parts by weight. Accordingly, even when the high molecular weight has no crosslinkable functional group, it is solvent resistant. Can be held.
[0027]
Furthermore, the organic phosphorus compound-containing resin composition of the present invention is improved in curability and storage stability by adding a curing catalyst capable of polymerizing styrene groups or a polymerization inhibitor capable of suppressing polymerization of styrene groups. Can be improved.
[0028]
Although the polyfunctional styrene compound used in the present invention can be cured without adding a curing catalyst, the curing of the polyfunctional styrene compound can be promoted by adding the curing catalyst. This allows curing at low temperatures. The addition amount is preferably set in a range that does not affect the dielectric constant and dielectric loss tangent, and is desirably 0.0005 to 10 parts by weight with the total amount of resin components in the resin composition being 100 parts by weight.
[0029]
Examples of curing catalysts that generate cation or radical active species capable of initiating polymerization of styrene groups by heat or light are shown below.
[0030]
Examples of the cationic polymerization initiator include diallyl iodonium salt, triallyl sulfonium salt and aliphatic sulfonium salt having BF ₄ , PF ₆ , AsF ₆ , and SbF ₆ as counter anions, and these commercially available products include SP manufactured by Asahi Denka Kogyo. -70,172, CP-66, Nippon Soda CI-2855, 2823, Sanshin Chemical Industries SI-100L, SI-150L, etc. can be used.
[0031]
Radical polymerization initiators include benzoin compounds such as benzoin or benzoin methyl, acetophenone or acetophenone compounds such as 2,2-dimethoxy-2-phenylacetophenone, thioxanthone compounds such as thioxanthone or 2,4-diethylthioxanthone Compound, 4,4′-diazidochalcone, bisazide compound such as 2,6-bis (4′-azidobenzal) cyclohexanone or 4,4′-diazidobenzophenone, azobisisobutylnitrile, 2,2-azobispropane Azo compounds such as m, m'-azoxystyrene or hydrazone, and 2,5-dimethyl-2,5-di (t-butylperoxy) hexane or 2,5-dimethyl-2,5-di (T-butylperoxy) hexyne-3, dicumyl peroxy Organic peroxides such as de thereof.
[0032]
In particular, it is desirable to add an organic peroxide or bisazide compound that can cause hydrogen abstraction of a compound that does not have a functional group, resulting in crosslinking between the crosslinking component and the high molecular weight product.
[0033]
The said polymerization inhibitor has the effect | action which increases the storage stability of the organophosphorus compound containing resin composition of this invention. The addition amount is preferably within a range that does not significantly disturb the dielectric properties and reactivity during curing, and is desirably 0.0005 to 5 parts by weight with respect to 100 parts by weight of the total amount of the resin components in the resin composition. When the polymerization inhibitor is added within the above range, an excessive crosslinking reaction during storage can be suppressed, and no significant curing failure is caused during curing.
[0034]
Examples of such polymerization inhibitors include quinones such as hydroquinone, p-benzoquinone, chloranil, trimethylquinone, 4-t-butylpyrocatechol, and aromatic diols.
[0035]
The organic phosphorus compound-containing resin composition of the present invention is used as a prepreg by impregnating and drying an organic or inorganic cloth or nonwoven fabric substrate. In addition, there is no restriction | limiting in particular about the base material of a prepreg, Various glass cloth, a glass nonwoven fabric, an aramid nonwoven fabric, a porous PTFE film, etc. can be used. The prepreg can be produced by immersing a cloth or non-woven fabric as a base material in a varnish produced using the resin composition, and then drying the cloth. Although the drying conditions after impregnation depend on the resin composition used, for example, when toluene is used as the solvent, it is preferable to dry at 80 to 130 ° C. for about 30 to 90 minutes.
[0036]
By laminating a conductive foil such as an electrolytic copper foil on the prepreg of the present invention and subjecting it to hot pressing, a laminate having a conductive layer on the surface can be produced. The thickness of the copper foil is preferably about 12 to 36 μm. The conditions of the press working depend on the resin composition to be used. For example, when polyphenylene ether is used as the high molecular weight material, it is preferably molded at 150 to 240 ° C. and 1 to 5 MPa for 1 to 3 hours. .
[0037]
The conductor layer of the above laminate is processed by wiring by a normal etching method, and a plurality of the conductor layers are laminated through the prepreg, and a multi-layer printed circuit board is manufactured by hot pressing. The multilayer printed board thus obtained has a low dielectric constant and dielectric loss tangent, and has flame retardancy. That is, the multilayer printed circuit board has excellent transmission characteristics and safety.
[0038]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be specifically described below with reference to examples and comparative examples. In the following description, “parts” refers to parts by weight unless otherwise specified. Tables 1 and 2 show the compositions and characteristics of Examples and Comparative Examples of the present invention.
[0039]
Hereinafter, the names of reagents used in Examples and Comparative Examples, synthesis methods, varnish preparation methods, and cured product evaluation methods will be described.
[0040]
(1) Synthesis of 1,2-bis (vinylphenyl) ethane (hereinafter referred to as BVPE) Into a 500 ml three-necked flask, 5.36 g (220 mmol) of granular magnesium for Grignard reaction (manufactured by Kanto Chemical) was taken, and a dropping funnel was used. A nitrogen inlet tube and a septum cap were attached. The whole system was heated and dehydrated with a drier while stirring the magnesium particles with a stirrer under a nitrogen stream.
[0041]
Next, 300 ml of dry tetrahydrofuran was taken into a syringe and injected through a septum cap. After cooling the solution to −5 ° C., 30.5 g (200 mmol) of vinylbenzyl chloride (VBC, manufactured by Tokyo Chemical Industry Co., Ltd.) was added dropwise over about 4 hours using a dropping funnel. After completion of the dropwise addition, stirring was continued at 0 ° C. for 20 hours. After completion of the reaction, the reaction solution was filtered to remove residual magnesium and concentrated with an evaporator.
[0042]
The concentrated solution was diluted with hexane, washed once with 3.6% hydrochloric acid aqueous solution and three times with pure water, and then dehydrated with magnesium sulfate.
[0043]
The dewatered aqueous solution was purified by passing through a short column of silica gel (Wakogel C300 manufactured by Wako Pure Chemical Industries) / hexane and vacuum dried to obtain BVPE. The obtained BVPE was a mixture of mm body (liquid), mp body (liquid), and pp body (crystal), and the yield was 90%.
[0044]
^When the structure was examined by ¹ H-NMR, the values agreed with literature values (6H-vinyl: α-2H, 6.7 ppm, β-4H, 5.7 to 5.2 ppm, 8H-aromatic: 7.1-7.35 ppm, 4H-methylene: 2.9 ppm). This BVPE was used as a crosslinking component.
[0045]
(2) Other reagents High molecular weight: made by Aldrich, poly-2,6-dimethyl-1,4-phenylene oxide (PPE)
Flame retardant PX-200: 1,8 phenylenebis (di-2,6 xylenyl phosphate) manufactured by Daihachi Chemical Industry Co., Ltd.
HCA-HQ: Sanko Co., Ltd. 10- (2,5-dihydroxyphenyl) -10H-9-oxa-10-phosphophenanthrene-10-oxide Curing catalyst: 25B: Nippon Oil & Fats, 2,5-dimethyl-2,5 -Bis (t-butylperoxy) hexyne-3
(3) Method for adjusting varnish A predetermined amount of a high molecular weight substance, a crosslinking component, chloroform and an organic phosphorus compound were stirred and dissolved and dispersed in a ball mill for about 8 hours to prepare a varnish of a resin composition.
[0046]
(4) Preparation of resin plate After applying the above varnish to a PET film and drying, it is peeled off and placed in a polytetrafluoroethylene spacer and heated under vacuum through a polyimide film and a mirror plate. The resin plate was obtained by pressurizing and curing. The heating conditions were 120 ° C./30 minutes, 150 ° C./30 minutes, 180 ° C./100 minutes, and multistage heating with a press pressure of 1.5 MPa. The size of the resin plate was 70 mm × 70 mm × 1.5 mm.
[0047]
(5) Production of prepreg The prepreg produced in each Example was produced by impregnating the varnish into a glass cloth (Nittobo # 2116) and drying at room temperature for about 1 hour and at 90 ° C. for 60 minutes.
[0048]
(6) Preparation of cured prepreg In order to know the characteristics of the laminated plate, 10 prepregs prepared above were stacked and heated and pressurized under vacuum to prepare a simulated substrate. The heating conditions were multi-stage heating at 120 ° C./30 minutes, 150 ° C./30 minutes, 180 ° C./100 minutes, and a press pressure of 1.5 MPa. The simulated substrate was 70 mm × 70 mm × 1.5 mm.
[0049]
(7) Measurement of dielectric constant and dielectric loss tangent The dielectric constant and dielectric loss tangent are measured at 10 GHz using a cavity resonator perturbation method (Agilent Technologies 8722ES network analyzer, Kanto Electronics Application Development cavity resonator). did.
[0050]
(8) Flame retardancy Flame retardancy was evaluated based on the UL-94 standard using a sample size of 70 mm × 3 mm × 1.5 mm, and the average burning time and the maximum burning time were measured.
[0051]
[Comparative Example 1]
Comparative Example 1 is a resin plate made from a resin composition to which no organic phosphorus compound is added. Although the dielectric properties were excellent, it did not have flame retardancy because it did not contain a flame retardant.
[0052]
[Examples 1-3]
Examples 1 to 3 are examples in which PX-200, which is solid at room temperature as an organic phosphorus compound, was added to the resin composition of Comparative Example 1 in different amounts. The evaluation results are shown in Table 1.
[0053]
It was confirmed that the combustion time was shortened as the content of the phosphorus component increased, and that flame retardancy was increased by the addition of the organic phosphorus compound. When the phosphorus content exceeds 1.5 wt%, flame retardancy equivalent to V-0 is achieved. At this time, the dielectric constant slightly increased from 2.50 to 2.52, but the dielectric loss tangent value decreased from 0.0022 to 0.0019. Thereby, a flame retardant resin composition having excellent dielectric properties was obtained.
[0054]
[Table 1]

[Examples 4 to 6]
Examples 4 to 6 are obtained by adding HCA-HQ, which is solid at room temperature, as an organic phosphorus compound to the resin composition of Comparative Example 1 in various amounts. The evaluation results are shown in Table 2.
[0055]
It was confirmed that the combustion time was shortened as the content of the phosphorus component increased, and that flame retardancy was increased by the addition of the organic phosphorus compound. When the phosphorus content exceeded 1.6 wt%, V-0 was almost achieved. At this time, although the dielectric constant slightly increased from 2.50 to 2.58, the value of dielectric loss tangent was 0.0022 and did not change. Thereby, a flame retardant resin composition having excellent dielectric properties was obtained.
[0056]
[Table 2]

Example 7
A prepreg was prepared using the varnish having the composition of Example 3. The produced prepreg had tack-free properties. Ten prepregs were stacked and heated and pressurized under vacuum to prepare a prepreg cured product. The resin content of the prepreg cured product was 36 wt%, and a flame retardance test was conducted. As a result, the average burning time was 0.2 seconds and the maximum burning time was 0.3 seconds. Achieved. The dielectric constant was 3.10 and the dielectric loss tangent was 0.004.
[0057]
The resin composition used for the prepreg has excellent melt fluidity, and can be suitably used as an interlayer adhesive for multilayer printed boards.
[0058]
Example 8
A rough surface of electrolytic copper foil was pasted on both sides of the prepreg produced in Example 7, and pressure and heating were performed under vacuum to produce a double-sided copper clad laminate. The heating conditions were 120 ° C./30 minutes, 150 ° C./30 minutes, 180 ° C./100 minutes, and a press pressure of 1.5 MPa. The copper foil and the prepreg showed good adhesion, which enabled the production of a multilayer printed board with low dielectric loss.
[0059]
Example 9
FIG. 1 is a schematic cross-sectional view showing an example of a production process of a multilayer printed board according to the present invention.
[0060]
In (A), a photoresist 3 (HS425 manufactured by Hitachi Chemical Co., Ltd.) is laminated on one side of a double-sided copper clad laminate having copper foil 2 on both sides of a resin substrate 1 obtained in the same manner as in Example 8, and the entire surface is exposed. did. Next, the test pattern was exposed by laminating a photoresist 3 (HS425 manufactured by Hitachi Chemical Co., Ltd.) on the surface where the photoresist 3 was not applied, and the unexposed photoresist was developed with a 1% sodium carbonate solution.
[0061]
In (B), the copper foil exposed with an etching solution of 5% sulfuric acid and 5% hydrogen peroxide was removed by etching to form a conductor wiring on one side of the double-sided copper-clad laminate.
[0062]
In (C), the remaining photoresist 3 was removed with a 3% sodium hydroxide solution to obtain a wiring board having wiring on one side. Similarly, two wiring boards were produced.
[0063]
In (D), the prepreg 4 of Example 7 was sandwiched between the wiring-side surfaces of the two wiring boards, and the layers were multilayered by heating and pressing under vacuum. The heating conditions were multi-stage heating at 120 ° C./30 minutes, 150 ° C./30 minutes, 180 ° C./100 minutes, and a press pressure of 1.5 MPa.
[0064]
In (E), photoresist 3 (Hitachi Chemical Co., Ltd. HS425) was laminated on the exterior copper on both sides of the produced multilayer board to expose the test pattern, and the unexposed photoresist was developed with 1% sodium carbonate solution.
[0065]
In (F), the exposed copper foil was removed by etching with an etching solution of 5% sulfuric acid and 5% hydrogen peroxide, and the remaining photoresist was removed with a 3% sodium hydroxide solution to form the exterior wiring 6.
[0066]
In (G), a through hole 7 for connecting the inner layer wiring 5 and the outer wiring 6 was formed by drilling.
[0067]
In (H), the wiring board was immersed in a colloidal solution of a plating catalyst, and the catalyst 8 was applied in the through hole 7 and on the substrate surface.
[0068]
In (I), after activating the plating catalyst 8, a seed film 9 of about 1 μm was provided with an electroless plating solution (CUST2000 manufactured by Hitachi Chemical Co., Ltd.).
[0069]
In (J), a photoresist (HN920 manufactured by Hitachi Chemical Co., Ltd.) was laminated on both sides of the wiring board.
[0070]
In (K), the through-hole 7 portion and the end portion of the wiring substrate were masked and exposed, and then developed with 3% sodium carbonate to provide the opening 10.
[0071]
In (L), an electrode 11 was provided at the end of the wiring board, and plated copper 12 was formed in the through hole 7 portion by about 18 μm by electrolytic plating.
[0072]
In (M), the electrode 11 was cut off and the remaining photoresist was removed with a 5% aqueous sodium hydroxide solution.
[0073]
In (N), the wiring board was immersed in an etching solution of 5% sulfuric acid and 5% hydrogen peroxide, and etched by about 1 μm to remove the seed film, thereby producing a multilayer wiring board. The obtained multilayer wiring board exhibited a low dielectric constant, a low dielectric loss tangent, and a high flame resistance.
[0074]
【The invention's effect】
According to the present invention, a resin composition having a low dielectric constant and dielectric loss tangent and giving a flame retardant cured product can be obtained.
[0075]
The present resin composition is suitable as an insulating material for high-frequency electrical components, and when applied to a multilayer printed circuit board for high-frequency signals, the effect of achieving both low dielectric loss and flame retardancy can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing a production process of a multilayer wiring board of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Resin substrate, 2 ... Electrolytic copper foil, 3 ... Photoresist, 4 ... Prepreg, 5 ... Inner layer wiring, 6 ... Outer layer wiring, 7 ... Through hole, 8 ... Plating catalyst, 9 ... Seed film, 10 ... Opening part , 11 ... electrode, 12 ... plated copper.

Claims (7)

10- (2,5-dihydroxyphenyl)-as a flame retardant containing 50 to 95 parts by weight of 1,2-bis (vinylphenyl) ethane as a crosslinking component and 100 parts by weight of the total resin component 10H-9-oxa-10-phospha include any Fe Nantoren 10-oxide or 1,3-phenylene bis (di-2,6 Kishireniruho scan Feto), poly-2,6-dimethyl-1 as a high polymer, A low dielectric loss tangent resin composition comprising 4-phenylene oxide . The low dielectric loss tangent resin composition according to claim 1, wherein the low dielectric loss tangent resin composition contains a curing catalyst capable of polymerizing styrene groups or a polymerization inhibitor capable of suppressing polymerization of styrene groups. 3. The flame retardant according to claim 1, wherein the total amount of the resin components in the resin composition is 100 parts by weight, and the flame retardant is added so that the phosphorus atom content is 1.5 to 5 parts by weight. The low dielectric loss tangent resin composition as described. Examples 100 parts by weight of the total amount of resin components having a low dielectric loss tangent resin composition, addition amount 0.0005 parts by weight of a curing catalyst, a polymerization inhibitor is 0.0005 parts by weight claim 2 or low dielectric loss tangent resin composition according to 3. A prepreg obtained by impregnating and drying an organic or inorganic cloth or nonwoven fabric with the low dielectric loss tangent resin composition according to any one of claims 1 to 4 . A laminated board, wherein a conductor layer is provided on at least one side of the prepreg according to claim 5 or a cured product thereof. A multilayer printed circuit board comprising the laminated board bonded to each other through a prepreg after wiring processing is performed on the conductor layer of the laminated board according to claim 6 .

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