JP2004182814A - Thermosetting resin, resin composition and cured product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new resin giving a cured product of high heat resistance, mechanical properties and improved flame retardancy, and to provide a resin composition including the resin. <P>SOLUTION: The thermosetting resin has naphthalene structure and benzoxazine structure represented by the general formula (1) (wherein, R<SB>1</SB>is a 1-10C organic group; R<SB>2</SB>is H or a 1-6C hydrocarbon group; and n is an integer of 1-10). This thermosetting resin is synthesized from a phenolic resin, an aniline and an aldehyde. The thermosetting resin composition can be obtained by compounding the aniline as an aromatic amine with an equimolar amount or less of other benzoxadine resin or epoxy resin. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

このようにして得られるＢＺＸ樹脂は単一の化合物の場合もあるが、多くの場合、オリゴマー、フェノール樹脂等の副生物を少量含む混合物であるが、主成分は上記反応生成物である。
【０００５】
このＢＸＺ樹脂は、下記反応式に示すように、加熱により開環重合反応を起こし、フェノール性水酸基と三級アミノ基を生成する。
【化６】

ビスフェノール類あるいはフェノール樹脂を原料に用いた場合、二官能性ＢＸＺ樹脂あるいは多官能性ＢＸＺ樹脂が得られ、開環重合反応に伴い三次元架橋反応が進行し、良好な機械的特性を有する硬化物が得られる。
【０００６】
ＢＸＺ樹脂（二官能性ＢＸＺ樹脂を含む）及びその組成物は、特開昭４９−４７３７８号公報、特開平２−６９５６７号公報、特開平４−２２７９２２号公報等で知られている。これらは、従来の硬化性樹脂に比較して難燃性が向上し、硬化した後の硬化物の機械的特性においても良好であることが報告されている。しかし、難燃性、機械的特性、さらには誘電率等の電気的特性において更なる特性向上が望まれていた。
【特許文献１】
特開昭４９−４７３７８号公報
【特許文献２】
特開平２−６９５６７号公報
【特許文献３】
特開平４−２２７９２２号公報
【０００７】
【発明が解決しようとする課題】
本発明は、硬化後において、耐熱性、難燃性、機械的特性、電気的特性等に優れた特性を有する新規なＢＸＺ樹脂を提供するものである。
【０００８】
【課題を解決するための手段】
すなわち、本発明は、下記一般式（１）で表される構造を有する熱硬化性樹脂である。
【化７】

（式中、Ｒ_１は炭素数１〜１０の飽和又は不飽和の脂肪族炭化水素基、炭素数１〜１０の置換又は無置換のアリール基のいずれかであり、Ｒ_２は水素又は炭素数１〜６の炭化水素基であり、ｎは１〜１０の整数を示す）
また、本発明は、前記の熱硬化性樹脂とそれが開環重合して生じた重合物からなる熱硬化性樹脂である。
ここで、上記一般式（１）のＲ_１は、フェニル基、メチルフェニル基、アリルフェニル基、エチニルフェニル基及びエチニルオキシフェニル基のいずれかであることは好ましい例である。そして、下記一般式（２）で表される熱硬化性樹脂は、本発明の熱硬化性樹脂の好ましい一例である。
【化８】

（式中、Ｒ_３は水素又は炭素数１〜４の少なくとも一つの不飽和基を有する有機基を示し、ｎは１〜１０の整数を示す）
【０００９】
更に、本発明は、式（３）で表されるフェノール樹脂と、式（４）で表されるアミンと、Ｒ_２ＣＨＯで表されるアルデヒド（但し、式中、Ｒ_１、Ｒ_２、Ｒ_３、ｎは、式（１）及び式（２）と同じ意味を示す）とを、フェノール性水酸基（ＯＨ）、アミノ基（ＮＨ_２）及びアルデヒド基（ＣＨＯ）のモル比が、ＯＨ：ＮＨ_２：ＣＨＯ＝１：１．８〜２．２：３．６〜４．４となる割合で反応させることを特徴とするベンゾキサジン構造を有する熱硬化性樹脂の製造方法である。
【化９】

【化１０】

【００１０】
また、本発明は、ベンゾキサジン環構造を有する硬化性樹脂を１０ｗｔ％以上含有する硬化性樹脂組成物である。
かかる硬化性樹脂組成物としては、ａ）前記熱硬化性樹脂の製造方法で副生する重合物（樹脂成分）を少量、好ましくは３０ｗｔ％以下含有する熱硬化性樹脂や、ｂ）前記熱硬化性樹脂１０重量部に他のベンゾキサジン環構造を有する熱硬化性樹脂を１〜１００重量部配合した熱硬化性樹脂組成物や、ｃ）前記熱硬化性樹脂１０重量部にエポキシ樹脂を１〜１００重量部配合した硬化性樹脂組成物や、ｄ）前記熱硬化性樹脂１０重量部に他のベンゾキサジン環構造を有する熱硬化性樹脂を１〜１００重量部とエポキシ樹脂を１〜１００重量部配合した硬化性樹脂組成物、あるいは、ｅ）前記熱硬化性樹脂１０重量部にポリイミド樹脂を１〜１００重量部配合した硬化性樹脂組成物、ｆ）前記熱硬化性樹脂１０重量部に他のベンゾキサジン環構造を有する熱硬化性樹脂を１〜１００重量部とポリイミド樹脂を１〜１００重量部配合した硬化性樹脂が好ましい例として挙げられる。
【００１１】
更に、本発明は前記の硬化性樹脂又は硬化性樹脂組成物を硬化させてなる硬化物である。
【００１２】
【発明の実施の形態】
本発明の熱硬化性樹脂は、ベンゾキサジン環を有する構成単位をナフチルジメチレン構造を介して結合した構造を有する多官能性のＢＸＺ樹脂である（以下、本発明のＢＸＺ樹脂ともいう）。この樹脂は、硬化後においては、良好な機械的特性、電気的特性を有するとともに、耐熱性と耐薬品性を有する硬化物となる。
【００１３】
本発明のＢＸＺ樹脂は、上記一般式（１）で表される熱硬化性樹脂又はこれとそのオリゴマー又は部分硬化物の混合物である。ここで、そのオリゴマーとは、前記反応式のように開環重合したものであるが、硬化するに至っていないものを言い、部分硬化物とは開環重合したものであるが、一部が硬化するに至ったものを言う。好ましくは、上記一般式（１）で表される熱硬化性樹脂からなるもの又はこれを主成分として、例えば８０ｗｔ％以上含み、そのオリゴマー又は部分重合物を含む混合物である。
【００１４】
一般式（１）において、Ｒ_１は炭素数１〜１０の飽和又は不飽和の脂肪族炭化水素基、無置換のアリール、又はアルキル、アルケニル、アルキニル及びアルキニルオキシから選ばれる置換基で置換した炭素数１〜１０のアリールのいずれかであるが、無置換のフェニル基、又はアルキル、アルケニル、アルコキシ、アルケニルオキシ置換フェニル基であって、炭素数が７〜１０の置換フェニル基が好ましい。Ｒ_２は水素又は炭素数１〜６の炭化水素基であって、好ましくは水素、メチル基、エチル基又はプロピル基である。ｎは１から１０の整数を示すが、通常はｎが異なる混合物であることが多い。この場合、平均のｎは１〜１０の範囲にある。
【００１５】
本発明のＢＸＺ樹脂は、式（３）で表されるフェノール樹脂と、式（４）で表されるアミンと、Ｒ_３ＣＨＯで表されるアルデヒドとを、フェノール樹脂のＯＨ：アミンのＮＨ_２：アルデヒドのＣＨＯのモル比約１：２：４で反応させて得られるが、モル比が理論量であったとしても、上記したように副反応が生じたり、モル比が理論量をはずれると更に副反応物が増加する。本発明の熱硬化性樹脂の製造方法で得られるＢＸＺ樹脂は、前記オリゴマー、部分硬化物の他に、樹脂状の反応副生物、例えばフェノール樹脂等を含み得る。なお、フェノール樹脂のフェノール性ＯＨが１モルとは、フェノール樹脂１分子中にフェノール性ＯＨを平均３ケ有する場合は、フェノール樹脂１／３モルがこれに該当すると定義される。
【００１６】
本発明のＢＸＺ樹脂は、前記のように式（３）で表されるフェノール樹脂と、式（４）で表される一級アミン及びＲ_２ＣＨＯで表されるアルデヒドから合成することができる。一級アミンとしてはアニリンが、アルデヒドとしてはホルムアルデヒドが好ましく挙げられる。反応理論量は、１：２：４であるが、反応条件や原料化合物の種類によって、反応性に差が生じ、全部の原料化合物が１００％反応しない場合もありうるので、好ましくは５０％前後の幅があり得る。例えば、フェノール樹脂のフェノール性ＯＨ１モルに対して、一級アミンを２〜４モル、好ましくは１．８〜２．２モル及びアルデヒドを３．５〜５モル、好ましくは３．６〜４．４モル又は１級アミン１モル当たり２モル以上、好ましくは２〜４モルの割合で用いて反応させることがよい。特に、アルデヒドはやや過剰に加えることがよい。有利な製造方法としては、１級アミンをアルデヒドへ徐々に加える方法により反応させたのち、フェノール樹脂を加え、２０分〜２４時間、７０〜１２０℃に保つことにより合成される。このとき、必要に応じて有機溶剤を用いることもできる。反応後、生成物を抽出等の合成化学的手法で単離・精製し縮合水等の揮発成分を乾燥又は除去することにより目的とする本発明のＢＸＺ樹脂が得られる。
【００１７】
本発明のＢＸＺ樹脂の原料となるフェノール樹脂としては、一般式（３）で表される化合物が、工業的に入手が容易で、その硬化物の耐湿性や電気的特性も良好なため実用上好適な化合物として挙げられる。
【００１８】
また、１級アミンとしては、メチルアミン、ブチルアミン、シクロヘキシルアミン等の脂肪族アミン、アニリン、トルイジン、アニシジン等の芳香族アミンを挙げることができるが、耐熱性の点で、芳香族アミンが好ましく、必須成分としてアニリンあるいは置換アニリンを用いることが有利である。また、アニリンあるいは置換アニリンとその他の複数のアミンを組み合わせて用いることもできる。置換アニリンとしては、トルイジンのような炭素数７〜１５の核アルキル置換アニリン類が好ましい。本発明のＢＸＺ樹脂の発明においては、上記のような各種アミン類が使用可能であるが、製法の発明においては、前記式（４）で表される芳香族アミンを使用することがより好ましい。一般式（４）において、Ｒ_３は水素又は炭素数１〜４の有機基であるが、好ましくは水素、少なくとも一つの不飽和基を有する有機基であり、炭素数１〜４のアルキル基、アルケニル基、アルキニル基又はアルキニルオキシ基がより好ましく、更に好ましくは水素、アリル基、エチニル基又はエチニルオキシ基である。
【００１９】
アルデヒドとしては、水溶液としても用いることができ、ホルムアルデヒド、アセトアルデヒド、ベンズアルデヒド等を挙げることができる。ホルムアルデヒドにおいては、ホルマリン水溶液として、またパラホルムアルデヒドとして、いずれの形態でも用いることができる。
【００２０】
本発明の熱硬化性樹脂組成物は、本発明のＢＸＺ樹脂を一成分として、好ましくは全樹脂成分の１０ｗｔ％以上、より好ましくは１０〜９０ｗｔ％を含む樹脂組成物である。この樹脂組成物は、本発明のＢＸＺ樹脂を樹脂の１０ｗｔ％以上含む限り任意の樹脂、充填材、添加剤等を配合し得る。本発明のＢＸＺ樹脂で他の樹脂を改質する場合は、本発明のＢＸＺ樹脂の配合量は通常５０ｗｔ％以下であり、他の樹脂で本発明のＢＸＺ樹脂を改質する場合は、本発明のＢＸＺ樹脂の配合量は通常５０ｗｔ％以上である。
本発明の熱硬化性樹脂組成物は、他のジヒドロベンゾキサジン環構造を有する熱硬化性樹脂、エポキシ樹脂又はその両者を配合することができる。この場合の、他のジヒドロベンゾキサジン環構造を有する熱硬化性樹脂又はエポキシ樹脂の配合量は、本発明のＢＸＺ樹脂１０重量部に対し、熱硬化性樹脂又はエポキシ樹脂１〜１００重量部、好ましくは１０〜５０重量部である。
また、本発明の硬化性樹脂組成物は、各種ポリイミド系樹脂を配合することができる。この場合の、ポリイミド系樹脂の配合量は、本発明のＢＸＺ樹脂１０重量部に対し、１〜１００重量部、好ましくは１０〜５０重量部である。
【００２１】
本発明のＢＸＺ樹脂は前記のようにジヒドロベンゾキサジン構造の開環重合反応により硬化する樹脂であり、硬化物の機械的特性の観点から、一般式（１）で示されるように、２つ以上のベンゼン環と２つ以上のジヒドロベンゾキサジン環構造を有することが必要である。これらが一つのものでは、可とう性に乏しく、充分な架橋構造が形成されず靭性に乏しい硬化物となる。また、３つ以上のものも、可とう性に乏しい硬化物となる。しかし、これら他のジヒドロベンゾキサジン環構造を有するＢＸＺ樹脂を、本発明のＢＸＺ樹脂に配合することにより、物性を改良することができる。
【００２２】
本発明のＢＸＺ樹脂は、上記反応式に示すように、加熱により開環重合反応を起こし、フェノール性水酸基と三級アミノ基を生成すると共に三次元架橋反応が進行し、良好な機械的特性を有する硬化物が得られる。この硬化物は低吸湿性、高いガラス転移温度、高強度・高弾性率、更には低硬化収縮率を示し、難燃性にも優れている。
【００２３】
本発明のＢＸＺ樹脂を例示すれば、下記式（Ａ）〜（Ｉ）で表される化合物又はそのオリゴマー若しくは部分硬化物を含む樹脂が好ましく挙げられる。これらは、いずれも上記反応により容易に合成することができ、１５０〜２５０℃に加熱することにより、機械的特性、電気的特性、耐湿性に優れた硬化物を得ることができる。
【００２４】
【化１１】

【００２５】
【化１２】

【００２６】
【化１３】

【００２７】
また、本発明の熱硬化樹脂又は熱硬化樹脂組成物は、硬化前においては、ジオキサン、テトラヒドロフラン、ジグライム等のエーテル系溶剤、エチルセロソルブアセテート、ブチルセロソルブアセテート等のエステル系溶剤、ジメチルホルムアミド、ジメチルアセトアミド、Ｎ−メチル−２−ピロリジノン等のアミド系溶剤、更にエポキシ樹脂やアクリレート樹脂に溶解しやすいという特徴を有しているため、各種樹脂との混合も容易である。
【００２８】
本発明の熱硬化性樹脂組成物に配合する他のジヒドロベンゾキサジン環構造を有する樹脂は、本発明のＢＸＺ樹脂と異なるものであれば制限はなく、ジヒドロベンゾキサジン環構造を１つのみ有するＢＸＺ樹脂や、本発明のＢＸＺ樹脂を与えない原料化合物、例えばフェノール、ナフトール、脂肪族アミン等を使用して得たＢＸＺ樹脂がある。これらの他のＢＸＺ樹脂は、本発明のＢＸＺ樹脂とは別個に合成して、その後混合してもよく、また、本発明のＢＸＺ樹脂を合成する際、本発明のＢＸＺ樹脂を与えない原料化合物を一部併用することによって、混合物として得ることもできる。
【００２９】
上記他のＢＸＺ樹脂としては、具体的には、下記式（ａ）〜（ｇ）で表される化合物又はそのオリゴマー等が挙げられる。
【００３０】
【化１４】

【００３１】
【化１５】

【００３２】
【化１６】

【００３３】
また、本発明の熱硬化性樹脂組成物に配合するエポキシ樹脂には格別の制限はないが、多官能ヒドロキシ化合物から誘導されるエポキシ樹脂であることが有利である。好ましいエポキシ樹脂としては、ビスフェノールＡ型エポキシ樹脂、フェノールノボラック型エポキシ樹脂、クレゾールノボラック型エポキシ樹脂があり、あるいは、可とう性付与の観点から、低粘度エポキシ樹脂として、ビスフェノールＦ型エポキシ樹脂、プロピレングリコール系脂肪族エポキシ樹脂、各種脂環式エポキシ樹脂、グリシジルエステル系エポキシ樹脂、グリシジルアミン型エポキシ樹脂、ヒダントイン型エポキシ樹脂があり、また、ビスフェノール型エポキシ樹脂の直接水素化反応で得られる水素化ビスフェノールＡ型エポキシ樹脂等に対しても良好な溶解性示すため、混合して用いることが出来る。
【００３４】
また、本発明の熱硬化性樹脂組成物に配合するポリイミド樹脂には格別の制限はないが、芳香族テトラカルボン酸無水物と芳香族ジアミンから得られるポリイミド、そのシリコン変性ポリイミド等が好ましく挙げられる。
本発明の熱硬化性樹脂及び熱硬化性樹脂組成物は、加熱することにより硬化物となる。
【００３５】
【実施例】
以下、合成例及び実施例により、本発明を具体的に説明するが、本発明はこれらの実施例に限定されるものではない。
なお、原料として使用した一般式（３）で表されるフェノール樹脂としては、明和化成社製のフェノール樹脂を使用した。その略称を以下に示す。
（ＮＰｈＯＨ８８）：フェノール性ＯＨ基当量＝２０６、軟化点温度＝８８℃
（ＮＰｈＯＨ１０８）：フェノール性ＯＨ基当量＝２２０、軟化点温度＝１０８℃
（ＮＰｈＯＨ９２）：フェノール性ＯＨ基当量＝２１２、軟化点温度＝９２℃
なお、ＢＸＺ樹脂の記号（Ａ）〜（Ｉ）及び（ａ）〜（ｇ）は、前記の化学式に付した記号に対応する。
【００３６】
実施例１
アニリン１８．６ｇ（０．２モル）をジオキサン２００ｍｌ中に溶解し、ホルムアルデヒド液（３６〜３８％水溶液）３２．５ｇを滴下し、室温下で５時間反応させた。その後、（ＮＰｈＯＨ８８）４１．２ｇ（ＯＨ基として０．２モル）を加え、撹拌下、１００℃〜１２０℃で、５時間反応させた。反応終了後、溶媒を真空除去し、ＢＸＺ樹脂（Ａ）４５ｇを得た。
得られた樹脂の軟化点を表１に示した。また、本実施例に用いたフェノール樹脂原料（ＮＰｈＯＨ８８）の赤外吸収スペクトルを図１に、また、合成したＢＸＺ樹脂の赤外吸収スペクトルを図２に示した。
【００３７】
（評価方法）
ＢＸＺ樹脂１０ｇを２００℃に維持したホットプレート上で１時間硬化させた後、物性の測定を行った。その結果を表２に示す。
なお、ガラス転移温度（Ｔｇ）は、動的粘弾性測定装置（ＤＭＡ）、熱膨張係数（ＣＴＥ）は、熱機械分析装置（ＴＭＡ）を、熱分解開始温度（５％重量減少温度）は、熱重量分析装置（ＴＧＡ）を用い、引張強度、引張伸び率及び引張弾性率はＪＩＳ Ｋ ６９１１に準じて測定を行った。
また、吸水率は、３ｍｍ厚の硬化物を作成した後、硬化物をＰＣＴ（１２１℃、２ａｔｍ）処理時間２０時間の条件で処理した後、ＰＣＴ処理前後の重量変化を測定し、吸水率を求めた。さらに、誘電率（使用周波数１ＭＨｚ）は、ＡＳＴＭ Ｄ １４９ に準じた方法に従って測定を行った。
【００３８】
実施例２〜６
原料化合物の種類を変えた他は、実施例１と同様のＯＨ：ＮＨ_２：ＣＨＯモル比率で本発明の各種のＢＸＺ樹脂を合成した。また、実施例１の記載と同様の方法により評価を行った。
【００３９】
比較例１〜２
原料化合物を変えた他は、実施例１と同様にして各種のＢＸＺ樹脂を合成した。また、実施例１の記載と同様の方法により評価を行った。
【００４０】
表１に得られたＢＸＺ樹脂の化学式に対応する略号、原料のフェノール樹脂（比較例はビスフェノール類）及びアミンの種類と、得られたＢＸＺ樹脂の軟化点を示す。なお、原料のアルデヒドは、全ての例において実施例１と同じホルムアルデヒド液を使用したので記載を省略した。また、原料の使用モル比についても全ての例において実施例１と同じ当量比としたので記載を省略した。
また、硬化物の物性を表２に示した。
【００４１】
【表１】

【００４２】
【表２】

【００４３】
【発明の効果】
本発明の熱硬化性樹脂は、硬化前の状態では、各種有機溶剤や樹脂への溶解性に優れているため、フェノール樹脂、エポキシ樹脂等の汎用の熱硬化性樹脂、あるいは、各種ポリイミド樹脂との複合化が容易であり、硬化物の電気特性や機械的特性が良好で、耐湿性も良好である。また、本発明の熱硬化性樹脂組成物は、硬化物の電気特性や機械的特性が良好で、耐湿性も良好である。したがって、本発明の熱硬化性樹脂又はその組成物は、プリント配線板用積層板、プリント配線板、プリント回路多層化用耐熱接着材料、半導体封止材、半導体搭載用モジュール、その他各種電子部品周辺部材として、また、自動車、航空機部材、建築部材等、さらには、炭素繊維や炭素電極あるいはセパレーターなどの各種複合材料等のバインダーやマトリックス樹脂として好適に用いることができる。
【図面の簡単な説明】
【図１】実施例１で使用したフェノール樹脂原料のＩＲスペクトル
【図２】実施例１で得られたＢＸＺ樹脂のＩＲスペクトル[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a thermosetting resin having a naphthalene structure and a benzoxazine ring structure (hereinafter, also referred to as BXZ resin) having excellent heat resistance, curing properties, flame retardancy, and good mechanical properties.
[0002]
[Prior art]
Various thermosetting resins such as an epoxy resin, a phenol resin, a polyimide resin, a melamine resin, and a polyimide resin have been developed, and have been applied to fields suited to their respective resin characteristics. Recently, copper-clad laminates for printed wiring boards, adhesives for multilayer wiring boards, sealing materials for semiconductors, adhesives for mounting semiconductors, modules for mounting semiconductors, or parts used for automobiles, aircraft, building components, etc. For a curable resin used for such purposes, a resin material having excellent stability and reliability under high temperature and high humidity is required. Further, from the viewpoint of reducing the environmental load, a resin material having halogen-free flame retardancy is strongly desired.
[0003]
In recent years, it has been reported that benzoxazine resins are resins having better heat resistance and moisture resistance of cured products than conventional phenolic resins (H. Ishida, et al., J. Polym. Sci. 32, p921 (1994), H. Ishida, et al., J. Appl. Polym. Sci., Vol. 61, 1595 (1996)). In addition, since these resins have ring-opening polymerization reactivity, they exhibit low curing shrinkage, and cured products after the ring-opening reaction have various characteristics such as low thermal expansion properties. (H. Ishida, et al., J. Polym. Sci., Vol. 34, 1019 (1994),). Further, they also show reactivity with epoxy resins and are effective as a curing agent (Japanese Patent Application Laid-Open No. 4-227922). However, these conventional resins generally have poor toughness in the properties of the cured product after the completion of the curing reaction, and are not sufficient in mechanical properties and electrical properties. In addition, in order to form a composite with other resins, solubility in various solvents and resins is required. However, the above-mentioned resins which have been reported so far are soluble in other organic substances such as solvents and liquid epoxy resins. The sex was inferior.
[0004]
The BXZ resin can be synthesized from a phenol compound, a primary amine and a primary aldehyde as shown in the following reaction formula. The following reaction formula shows the case where phenol is used as a raw material and aniline is used as a primary amine and formaldehyde is used as a primary aldehyde.
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The BZX resin thus obtained may be a single compound, but in many cases, it is a mixture containing a small amount of by-products such as oligomers and phenol resins, but the main component is the above reaction product.
[0005]
The BXZ resin causes a ring-opening polymerization reaction by heating to generate a phenolic hydroxyl group and a tertiary amino group as shown in the following reaction formula.
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When a bisphenol or phenol resin is used as a raw material, a bifunctional BXZ resin or a polyfunctional BXZ resin is obtained, and a three-dimensional crosslinking reaction proceeds with the ring-opening polymerization reaction, and the cured product has good mechanical properties. Is obtained.
[0006]
BXZ resins (including bifunctional BXZ resins) and compositions thereof are known from JP-A-49-47378, JP-A-2-69567, JP-A-4-227922 and the like. These are reported to have improved flame retardancy as compared with conventional curable resins and to have good mechanical properties of cured products after curing. However, further improvement in electrical characteristics such as flame retardancy, mechanical characteristics, and dielectric constant has been desired.
[Patent Document 1]
JP-A-49-47378 [Patent Document 2]
JP-A-2-69567 [Patent Document 3]
JP-A-4-227922
[Problems to be solved by the invention]
The present invention provides a novel BXZ resin having excellent properties such as heat resistance, flame retardancy, mechanical properties, and electrical properties after curing.
[0008]
[Means for Solving the Problems]
That is, the present invention is a thermosetting resin having a structure represented by the following general formula (1).
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(Wherein, R ₁ is a saturated or unsaturated aliphatic hydrocarbon group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 1 to 10 carbon atoms, and R ₂ is hydrogen or carbon atoms. 1 to 6 hydrocarbon groups, and n represents an integer of 1 to 10)
Further, the present invention is a thermosetting resin comprising the thermosetting resin and a polymer produced by ring-opening polymerization of the thermosetting resin.
Here, it is a preferable example that R _{1 in the} general formula (1) is any _one of a phenyl group, a methylphenyl group, an allylphenyl group, an ethynylphenyl group, and an ethynyloxyphenyl group. The thermosetting resin represented by the following general formula (2) is a preferred example of the thermosetting resin of the present invention.
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(Wherein, R ₃ represents hydrogen or an organic group having at least one unsaturated group having 1 to 4 carbon atoms, and n represents an integer of 1 to 10)
[0009]
Further, the present invention provides a phenolic resin represented by the formula (3), an amine represented by the formula (4), and an aldehyde represented by R ₂ CHO (where R ₁ , R ₂ , R ₃ and n have the same meanings as in formulas (1) and (2)), and the molar ratio of phenolic hydroxyl group (OH), amino group (NH ₂ ) and aldehyde group (CHO) is OH: NH ₂ : A method for producing a thermosetting resin having a benzoxazine structure, characterized by reacting at a ratio of CHO = 1: 1.8 to 2.2: 3.6 to 4.4.
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[0010]
Further, the present invention is a curable resin composition containing a curable resin having a benzoxazine ring structure at 10 wt% or more.
Examples of the curable resin composition include: a) a thermosetting resin containing a small amount of a polymer (resin component) by-produced in the method for producing the thermosetting resin, preferably 30 wt% or less; and b) the thermosetting resin. A thermosetting resin composition in which 1 to 100 parts by weight of another thermosetting resin having a benzoxazine ring structure is blended with 10 parts by weight of a thermosetting resin; 1 to 100 parts by weight of a thermosetting resin having another benzoxazine ring structure and 1 to 100 parts by weight of an epoxy resin are mixed with 10 parts by weight of the thermosetting resin. A curable resin composition, or e) a curable resin composition obtained by mixing 1 to 100 parts by weight of a polyimide resin with 10 parts by weight of the thermosetting resin, and f) another benzoxazine ring in 10 parts by weight of the thermosetting resin. Structure Curable resin a thermosetting resin is blended to 100 parts by weight to 100 parts by weight of the polyimide resin having are preferred examples.
[0011]
Further, the present invention is a cured product obtained by curing the curable resin or the curable resin composition.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
The thermosetting resin of the present invention is a polyfunctional BXZ resin having a structure in which constituent units having a benzoxazine ring are bonded via a naphthyl dimethylene structure (hereinafter, also referred to as BXZ resin of the present invention). After curing, this resin has good mechanical and electrical properties, and becomes a cured product having heat resistance and chemical resistance.
[0013]
The BXZ resin of the present invention is a thermosetting resin represented by the general formula (1) or a mixture of the thermosetting resin and its oligomer or partially cured product. Here, the oligomer refers to a product that has undergone ring-opening polymerization as in the above reaction formula, but has not yet been cured, and a partially cured product refers to a product that has undergone ring-opening polymerization, but is partially cured. Say what led to you. Preferably, it is a thermosetting resin represented by the general formula (1) or a mixture containing the thermosetting resin as a main component in an amount of, for example, 80% by weight or more and an oligomer or a partial polymer thereof.
[0014]
In the general formula (1), R ₁ is a saturated or unsaturated aliphatic hydrocarbon group having 1 to 10 carbon atoms, unsubstituted aryl, or carbon substituted with a substituent selected from alkyl, alkenyl, alkynyl and alkynyloxy. It is any of the aryls having the formulas 1 to 10, but is preferably an unsubstituted phenyl group or an alkyl, alkenyl, alkoxy, or alkenyloxy-substituted phenyl group having 7 to 10 carbon atoms. R ₂ is hydrogen or a hydrocarbon group having 1 to 6 carbon atoms, preferably hydrogen, a methyl group, an ethyl group or a propyl group. n represents an integer of 1 to 10, but usually, n is often a mixture different from each other. In this case, the average n is in the range of 1-10.
[0015]
BXZ resin of the present invention, a phenol resin represented by the formula (3), with an amine of the formula _(4), an aldehyde represented by R 3 CHO, phenolic resins OH: NH amine ₂ : The reaction is carried out at a molar ratio of aldehyde to CHO of about 1: 2: 4. Even if the molar ratio is a stoichiometric amount, if a side reaction occurs or the molar ratio deviates from the stoichiometric amount as described above. Further, the amount of by-products increases. The BXZ resin obtained by the method for producing a thermosetting resin of the present invention may contain, in addition to the oligomer and the partially cured product, a resinous by-product such as a phenol resin. In addition, 1 mol of the phenolic OH of the phenolic resin is defined as 1/3 mol of the phenolic resin when one molecule of the phenolic OH has an average of 3 phenolic OHs in one molecule of the phenolic resin.
[0016]
The BXZ resin of the present invention can be synthesized from the phenol resin represented by the formula (3), the primary amine represented by the formula (4) and the aldehyde represented by R ₂ CHO as described above. Preferred examples of the primary amine include aniline, and examples of the aldehyde include formaldehyde. The theoretical amount of the reaction is 1: 2: 4, but the reactivity may vary depending on the reaction conditions and the type of the starting compounds, and 100% of all starting compounds may not react. There can be widths. For example, based on 1 mole of the phenolic OH of the phenolic resin, 2 to 4 moles of the primary amine, preferably 1.8 to 2.2 moles, and 3.5 to 5 moles, preferably 3.6 to 4.4 moles of the aldehyde. The reaction may be carried out using at least 2 moles, preferably 2 to 4 moles, per mole of the primary amine. In particular, the aldehyde is preferably added in a slight excess. As an advantageous production method, the reaction is carried out by gradually adding a primary amine to an aldehyde, and then a phenol resin is added, and the mixture is kept at 70 to 120 ° C. for 20 minutes to 24 hours. At this time, an organic solvent can be used if necessary. After the reaction, the desired BXZ resin of the present invention can be obtained by isolating and purifying the product by a synthetic chemical method such as extraction and drying or removing volatile components such as condensed water.
[0017]
As the phenol resin which is a raw material of the BXZ resin of the present invention, a compound represented by the general formula (3) is industrially easily available, and its cured product has good moisture resistance and electrical properties, so that it is practically usable. Preferred compounds are mentioned.
[0018]
Examples of the primary amine include aliphatic amines such as methylamine, butylamine and cyclohexylamine, and aromatic amines such as aniline, toluidine and anisidine.From the viewpoint of heat resistance, aromatic amines are preferable. It is advantageous to use aniline or a substituted aniline as an essential component. Further, aniline or a substituted aniline may be used in combination with a plurality of other amines. As the substituted aniline, core alkyl-substituted anilines having 7 to 15 carbon atoms such as toluidine are preferable. In the invention of the BXZ resin of the present invention, various amines as described above can be used, but in the invention of the production method, it is more preferable to use the aromatic amine represented by the formula (4). In the general formula (4), R ₃ is hydrogen or an organic group having 1 to 4 carbon atoms, preferably hydrogen, an organic group having at least one unsaturated group, and an alkyl group having 1 to 4 carbon atoms. Alkenyl, alkynyl or alkynyloxy groups are more preferred, and hydrogen, allyl, ethynyl or ethynyloxy groups are more preferred.
[0019]
The aldehyde can be used as an aqueous solution, and examples thereof include formaldehyde, acetaldehyde, and benzaldehyde. Formaldehyde can be used in any form as an aqueous formalin solution or as paraformaldehyde.
[0020]
The thermosetting resin composition of the present invention is a resin composition containing, as one component, the BXZ resin of the present invention, preferably 10 wt% or more, more preferably 10 to 90 wt% of all resin components. This resin composition may contain any resin, filler, additive, and the like as long as the resin contains the BXZ resin of the present invention in an amount of 10 wt% or more of the resin. When modifying another resin with the BXZ resin of the present invention, the blending amount of the BXZ resin of the present invention is usually 50 wt% or less, and when modifying the BXZ resin of the present invention with another resin, the present invention is applied. Is usually 50 wt% or more.
The thermosetting resin composition of the present invention may contain another thermosetting resin having a dihydrobenzoxazine ring structure, an epoxy resin, or both. In this case, the blending amount of the thermosetting resin or epoxy resin having another dihydrobenzoxazine ring structure is 1 to 100 parts by weight of the thermosetting resin or epoxy resin with respect to 10 parts by weight of the BXZ resin of the present invention. Preferably it is 10 to 50 parts by weight.
In addition, the curable resin composition of the present invention may contain various polyimide resins. In this case, the amount of the polyimide resin is 1 to 100 parts by weight, preferably 10 to 50 parts by weight, based on 10 parts by weight of the BXZ resin of the present invention.
[0021]
The BXZ resin of the present invention is a resin which is cured by the ring-opening polymerization reaction of the dihydrobenzoxazine structure as described above. It is necessary to have the above benzene ring and two or more dihydrobenzoxazine ring structures. When these are one, the cured product is poor in flexibility, does not form a sufficient crosslinked structure, and has poor toughness. Also, three or more cured products have poor flexibility. However, by blending these other BXZ resins having a dihydrobenzoxazine ring structure with the BXZ resin of the present invention, the physical properties can be improved.
[0022]
As shown in the above reaction formula, the BXZ resin of the present invention causes a ring-opening polymerization reaction by heating, generates a phenolic hydroxyl group and a tertiary amino group, and a three-dimensional cross-linking reaction proceeds. A cured product having the above is obtained. The cured product exhibits low moisture absorption, high glass transition temperature, high strength and high elastic modulus, and also low curing shrinkage, and is excellent in flame retardancy.
[0023]
When the BXZ resin of the present invention is exemplified, a resin containing a compound represented by the following formulas (A) to (I) or an oligomer or a partially cured product thereof is preferably mentioned. All of these can be easily synthesized by the above reaction, and by heating to 150 to 250 ° C., a cured product having excellent mechanical properties, electrical properties, and moisture resistance can be obtained.
[0024]
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[0025]
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[0026]
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[0027]
Further, the thermosetting resin or thermosetting resin composition of the present invention before curing, dioxane, tetrahydrofuran, ether solvents such as diglyme, ethyl cellosolve acetate, ester solvents such as butyl cellosolve acetate, dimethylformamide, dimethylacetamide, Since it has a feature that it is easily soluble in amide solvents such as N-methyl-2-pyrrolidinone, and further in epoxy resins and acrylate resins, it can be easily mixed with various resins.
[0028]
The other resin having a dihydrobenzoxazine ring structure blended in the thermosetting resin composition of the present invention is not limited as long as it is different from the BXZ resin of the present invention, and has only one dihydrobenzoxazine ring structure. BXZ resin having no BXZ resin of the present invention or a BXZ resin obtained by using a raw material compound that does not give the BXZ resin of the present invention, such as phenol, naphthol, or an aliphatic amine. These other BXZ resins may be synthesized separately from the BXZ resin of the present invention, and then mixed together. Also, when synthesizing the BXZ resin of the present invention, a starting compound which does not give the BXZ resin of the present invention Can be obtained as a mixture by partially using
[0029]
Specific examples of the other BXZ resin include compounds represented by the following formulas (a) to (g) or oligomers thereof.
[0030]
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[0031]
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[0032]
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[0033]
Although there is no particular limitation on the epoxy resin to be added to the thermosetting resin composition of the present invention, an epoxy resin derived from a polyfunctional hydroxy compound is advantageous. Preferred epoxy resins include bisphenol A type epoxy resin, phenol novolak type epoxy resin, and cresol novolak type epoxy resin, or, from the viewpoint of imparting flexibility, bisphenol F type epoxy resin, propylene glycol as a low viscosity epoxy resin. Based epoxy resin, various alicyclic epoxy resins, glycidyl ester epoxy resin, glycidylamine type epoxy resin, hydantoin type epoxy resin, and hydrogenated bisphenol A obtained by direct hydrogenation reaction of bisphenol type epoxy resin It shows good solubility in epoxy resins and the like, and can be used in combination.
[0034]
Further, the polyimide resin to be blended in the thermosetting resin composition of the present invention is not particularly limited, but a polyimide obtained from an aromatic tetracarboxylic anhydride and an aromatic diamine, a silicon-modified polyimide thereof, and the like are preferable. .
The thermosetting resin and the thermosetting resin composition of the present invention are cured when heated.
[0035]
【Example】
Hereinafter, the present invention will be specifically described with reference to Synthesis Examples and Examples, but the present invention is not limited to these Examples.
In addition, as the phenol resin represented by the general formula (3) used as a raw material, a phenol resin manufactured by Meiwa Kasei Co., Ltd. was used. The abbreviations are shown below.
(NPhOH88): phenolic OH group equivalent = 206, softening point temperature = 88 ° C.
(NPhOH108): phenolic OH group equivalent = 220, softening point temperature = 108 ° C.
(NPhOH92): phenolic OH group equivalent = 212, softening point temperature = 92 ° C.
The symbols (A) to (I) and (a) to (g) of the BXZ resin correspond to the symbols given to the above chemical formulas.
[0036]
Example 1
18.6 g (0.2 mol) of aniline was dissolved in 200 ml of dioxane, 32.5 g of a formaldehyde solution (36-38% aqueous solution) was added dropwise, and the mixture was reacted at room temperature for 5 hours. Then, 41.2 g (0.2 mol as OH group) of (NPhOH88) was added, and the mixture was reacted at 100 ° C to 120 ° C for 5 hours with stirring. After completion of the reaction, the solvent was removed in vacuo to obtain 45 g of BXZ resin (A).
Table 1 shows the softening points of the obtained resins. FIG. 1 shows the infrared absorption spectrum of the phenol resin raw material (NPhOH88) used in this example, and FIG. 2 shows the infrared absorption spectrum of the synthesized BXZ resin.
[0037]
(Evaluation method)
After curing 10 g of the BXZ resin on a hot plate maintained at 200 ° C. for 1 hour, physical properties were measured. Table 2 shows the results.
The glass transition temperature (Tg) is determined by a dynamic viscoelasticity analyzer (DMA), the coefficient of thermal expansion (CTE) is determined by a thermomechanical analyzer (TMA), and the thermal decomposition onset temperature (5% weight loss temperature) is determined by: Using a thermogravimetric analyzer (TGA), the tensile strength, tensile elongation and tensile modulus were measured according to JIS K 6911.
The water absorption was determined by preparing a cured product having a thickness of 3 mm, treating the cured product under the conditions of a PCT (121 ° C., 2 atm) treatment time of 20 hours, and measuring a change in weight before and after the PCT treatment. I asked. Further, the dielectric constant (used frequency 1 MHz) was measured according to a method according to ASTM D149.
[0038]
Examples 2 to 6
Various BXZ resins of the present invention were synthesized at the same OH: NH ₂ : CHO molar ratio as in Example 1 except that the type of the starting compound was changed. The evaluation was performed in the same manner as described in Example 1.
[0039]
Comparative Examples 1-2
Various BXZ resins were synthesized in the same manner as in Example 1 except that the raw material compounds were changed. The evaluation was performed in the same manner as described in Example 1.
[0040]
Table 1 shows abbreviations corresponding to the chemical formulas of the obtained BXZ resin, types of phenol resin (bisphenols in Comparative Examples) and amine as raw materials, and softening points of the obtained BXZ resin. The starting material aldehyde was omitted in all examples because the same formaldehyde solution as in Example 1 was used. In addition, the molar ratios of the raw materials used were the same as in Example 1 in all the examples, and therefore the description was omitted.
Table 2 shows the physical properties of the cured product.
[0041]
[Table 1]

[0042]
[Table 2]

[0043]
【The invention's effect】
The thermosetting resin of the present invention, in a state before curing, is excellent in solubility in various organic solvents and resins, a phenol resin, a general-purpose thermosetting resin such as an epoxy resin, or various polyimide resins. Is easy to be compounded, and the cured product has good electrical and mechanical properties and good moisture resistance. Further, the thermosetting resin composition of the present invention has good electrical properties and mechanical properties of the cured product, and also has good moisture resistance. Therefore, the thermosetting resin of the present invention or the composition thereof can be used for a laminate for a printed wiring board, a printed wiring board, a heat-resistant adhesive material for multilayered printed circuits, a semiconductor sealing material, a module for mounting a semiconductor, and other various electronic components. It can be suitably used as a member, an automobile, an aircraft member, a building member, and the like, as well as a binder and a matrix resin of various composite materials such as carbon fibers, carbon electrodes, and separators.
[Brief description of the drawings]
FIG. 1 is an IR spectrum of a phenolic resin raw material used in Example 1. FIG. 2 is an IR spectrum of a BXZ resin obtained in Example 1.

Claims (11)

A thermosetting resin represented by the following general formula (1).

(Wherein, R ₁ represents a saturated or unsaturated aliphatic hydrocarbon group having 1 to 10 carbon atoms, unsubstituted aryl, or 1 to 1 carbon atoms substituted with a substituent selected from alkyl, alkenyl, alkynyl and alkynyloxy. Any of 10 aryls, R ₂ is hydrogen or a hydrocarbon group having 1 to 6 carbon atoms, and n represents an integer of 1 to 10) R ₁ in the general formula (1) is a phenyl group, methylphenyl group, allyl phenyl group, a thermosetting resin according to claim 1 is any one selected from the group consisting of ethynyl phenyl group and an ethynyl oxyphenyl group. The thermosetting resin according to claim 1, represented by the following general formula (2).

(In the formula, R ₃ represents hydrogen or an organic group having at least one unsaturated bond, and n represents an integer of 1 to 10.) A thermosetting resin comprising the thermosetting resin according to claim 1 and a small amount of a polymer thereof. A phenolic resin represented by the formula (3), an amine represented by the formula (4), and an aldehyde represented by R ₂ CHO (where R ₂ represents hydrogen or a hydrocarbon group having 1 to 6 carbon atoms) the) and a phenolic hydroxyl group (OH), the molar ratio of amino groups (NH ₂₎ and an aldehyde group (CHO) _{may, OH: NH 2: CHO =} 1: 1.8~2.2: 3.6~4 4. A method for producing a thermosetting resin, wherein the reaction is carried out at a ratio of 4.

(Where n represents an integer of 1 to 10)

(Wherein, R ₃ represents hydrogen or an organic group having 1 to 4 carbon atoms) A thermosetting resin composition containing the curable resin according to any one of claims 1 to 4 in an amount of 10 wt% or more. The thermosetting resin composition according to claim 6, wherein 1 to 100 parts by weight of another thermosetting resin having a benzoxazine ring structure is blended with 10 parts by weight of the curable resin according to any one of claims 1 to 4. The thermosetting resin composition according to claim 6, wherein 1 to 100 parts by weight of an epoxy resin is blended with 10 parts by weight of the thermosetting resin according to claim 1. The thermosetting resin composition according to claim 6, wherein 1 to 100 parts by weight of a polyimide resin is blended with 10 parts by weight of the thermosetting resin according to claim 1. A cured product obtained by curing the thermosetting resin according to claim 1. A cured product obtained by curing the thermosetting resin composition according to claim 6.

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