JP2004163765A - Curable resin composition, sealing material for display element, end sealing material for display element, and display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curable resin composition optimal for a display element by a liquid crystal, dispensing method to provide a sealing material for display element and an end sealing material for display element using the above composition, and to provide a display element by using them. <P>SOLUTION: The curable resin composition has ≥70% gel fraction after thermosetting reaction and ≥70% gel fraction after photosetting reaction. The curable resin composition is excellent in storage stability and causes little color irregularity in liquid crystal display when the resin composition is used as a sealing material for a liquid crystal display element or as an end sealing material for a liquid crystal display element in the liquid crystal display element, because the component of the resin composition does not dissolve into the liquid crystal material to cause contamination of the liquid crystal. The resin composition therefore is particularly optimal for the manufacture of a display element by the liquid crystal dispensing method. The sealing material for display element and the end sealing material for display element are also obtained from the composition. <P>COPYRIGHT: (C)2004,JPO

Description

【００５１】
式中、Ｒは水素、炭素数４以下の脂肪族炭化水素残鎖を表す。Ｒが炭素数４を超える脂肪族炭化水素残鎖であると、光重合開始剤を配合したときの保存安定性は増加するものの、置換基の立体障害により反応性が低下することがある。
一般式（４）で表される分子骨格を有するベンゾイン（エーテル）類化合物としては、例えば、下記一般式（５）で表される化合物が挙げられる。
【００５２】
【化２】

【００５３】
式中、Ｒは水素又は炭素数４以下の脂肪族炭化水素残基を表し、Ｘは炭素数１３以下の２官能イソシアネート誘導体の残基を表し、Ｙは炭素数４以下の脂肪族炭化水素残基又は残基を構成する炭素と酸素の原子数比が３以下の残基を表す。Ｘが炭素数１３を超える２官能イソシアネート誘導体の残基であると、液晶に溶解しやすくなることがあり、Ｙが炭素数４を超える脂肪族炭化水素基又は炭素と酸素の原子数比が３を超える残基であると、液晶に溶解しやすくなることがある。
【００５４】
上記光重合開始剤としては他の、例えば、ベンゾフェノン、２，２−ジエトキシアセトフェノン、ベンジル、ベンゾイルイソプロピルエーテル、ベンジルジメチルケタール、１−ヒドロキシシクロヘキシルフェニルケトン、チオキサントン等を単独又は２種以上を併用することができる。
【００５５】
上記光重合開始剤の添加量としては、硬化性樹脂１００重量部に対して０．１〜１０重量部が好ましい。０．１重量部未満であると、光重合を開始する能力が不足して効果が得られないことがあり、１０重量部を超えると、未反応の光重合開始剤が多く残ることがあり、耐候性が悪くなることがある。より好ましくは１〜５重量％である。
【００５６】
上記硬化剤は、加熱により硬化性樹脂組成物中のエポキシ基及び／又はアクリル基を反応させ、架橋させるためのものであり、硬化後の硬化性樹脂組成物の接着性、耐湿性を向上させる役割を有する。上記硬化剤としては、融点が１００℃以上の潜在性硬化剤が好適に用いられる。融点が１００℃以下の硬化剤を使用すると保存安定性が著しく悪くなることがある。
【００５７】
このような硬化剤としては、１，３−ビス［ヒドラジノカルボノエチル−５−イソプロピルヒダントイン］等のヒドラジド化合物、ジシアンジアミド、グアニジン誘導体、１−シアノエチル−２−フェニルイミダゾール、Ｎ−［２−（２−メチル−１−イミダゾリル）エチル］尿素、２，４−ジアミノ−６−［２’−メチルイミダゾリル−（１’）］−エチル−ｓ−トリアジン、Ｎ，Ｎ’−ビス（２−メチル−１−イミダゾリルエチル）尿素、Ｎ，Ｎ’−（２−メチル−１−イミダゾリルエチル）−アジポアミド、２−フェニル−４−メチル−５−ヒドロキシメチルイミダゾール、２−フェニル−４，５−ジヒドロキシメチルイミダゾール等のイミダゾール誘導体、変性脂肪族ポリアミン、テトラヒドロ無水フタル酸、エチレングリコールビス（アンヒドロトリメリテート）等の酸無水物、各種アミンとエポキシ樹脂との付加生成物等が挙げられる。これらは、単独で用いても、２種類以上が用いられても良い。
【００５８】
上記１分子内に（メタ）アクリル基とエポキシ基とをそれぞれ少なくとも１つ以上有する化合物としてアクリル酸変性エポキシ樹脂を用いる場合には、アクリルエポキシ樹脂の反応性はその構造より大きく変化し、ウレタン変性エポキシ樹脂の場合にはその安定性から反応性の高い硬化剤を用いても保存安定性に優れるが、（メタ）アクリル酸変性エポキシ樹脂の場合には反応性が高く、融点が１００℃以上の反応性の低い硬化剤が保存安定性の面より好ましい。
【００５９】
上記硬化剤の配合割合としては、硬化性樹脂重量／硬化剤重量が３〜１０であることが好ましい。上記範囲外では硬化物の接着性、耐薬品性が低下し、高温高湿動作試験での液晶の特性劣化が早まることがある。
【００６０】
また、上記硬化剤としては、固体硬化剤粒子の表面が微粒子により被覆されている被覆硬化剤が好適である。上記被覆硬化剤を硬化剤として用いれば、一液タイプとしても非常に高い保存安定性が得られる。固体硬化剤の表面を、揮発性に乏しくかつ有機物への溶解性に乏しい微粒子によって被覆した被覆硬化剤を用いることによって、予め硬化剤を配合していても高い保存安定性を有する硬化性樹脂組成物が得られる。
【００６１】
本明細書において上記固体硬化剤とは、室温では固体であり、加熱により溶融又は軟化して硬化性樹脂と反応を開始する硬化剤をいう。かかる固体硬化剤としては、融点又は軟化点が室温以上である硬化剤であれば特に限定されず、例えば、固体アミン化合物、フェノール系化合物、酸無水物等が挙げられる。なかでも、低温での反応性に優れていることから、固体アミン化合物が好ましい。
【００６２】
上記固形アミン化合物とは、分子中に１個以上の１〜３級のアミノ基を有する固体状の化合物のことをいい、例えば、メタフェニレンジアミン、ジアミノジフェニルメタン等の芳香族アミン、２−メチルイミダゾール、１，２−ジメチルイミダゾール、１−シアノエチル−２−メチルイミダゾール等のイミダゾール化合物、２−メチルイミダゾリン等のイミダゾリン化合物、セバチン酸ジヒドラジド、イソフタル酸ジヒドラジド等のジヒドラジド化合物が挙げられる。これらの固形アミン化合物のうち市販されているものとしては、例えば、アミキュアＰＮ−２３、アミキュアＭＹ−２４（以上、味の素ファインテクノ社製）等のアミンアダクト類、ジシアンジアミド等が挙げられる。なかでも１級アミン又は２級アミンが好ましい。
【００６３】
上記多価フェノール系化合物としては、例えば、ポリフェノール化合物、ノボラック型フェノール樹脂が挙げられる。これらの多価フェノール系化合物のうち市販されているものとしては、例えば、エピキュア１７０、エピキュアＹＬ６０６５、エピキュアＭＰ４０２ＦＰＩ（以上、ジャパンエポキシレジン社製）等が挙げられる。
【００６４】
上記酸無水物としては、例えば、グリセリンビス（アンヒドロトリメリテート）、エチレングリコールビス（アンヒドロトリメリテート）、テトラヒドロ無水フタル酸、ヘキサヒドロ無水フタル酸、４−メチルヘキサヒドロ無水フタル酸、３−メチルテトラヒドロ無水フタル酸等が挙げられる。これらの酸無水物のうち市販されているものとしては、例えば、エピキュアＹＨ−３０６、ＹＨ−３０７（以上、ジャパンエポキシレジン社製）等が挙げられる。
【００６５】
上記固体硬化剤粒子の平均粒子径としては特に限定されないが、０．１〜５０μｍであることが好ましい。０．１μｍ未満であると、微粒子によって効率よく表面を被覆できなくなることがあり、５０μｍを超えると、硬化性樹脂組成物に配合した際、保存時に硬化剤の沈殿が起こったり、硬化にムラが起こってしまったりすることがある。より好ましくは０．５〜１０μｍである。
【００６６】
上記固体硬化剤粒子の表面を被覆する微粒子としてはＳｉ、Ａｌ、Ｔｉ、Ｆｅ、Ｍｎ、Ｍｇ等の酸化物、水酸化物、ハロゲン化物やスチレンビーズ、微粒ゴム等からなるものが挙げられる。これらの微粒子は単独で用いてもよく、２種以上を併用してもよい。
【００６７】
上記微粒子の平均粒子径は０．０５μｍ以下であることが好ましい。０．０５μｍを超えると、効率よく固体硬化剤粒子の表面を被覆させられないことがある。より好ましくは０．０３μｍ以下である。また、上記微粒子の粒子径は、固体硬化剤粒子の粒子径の１０％以下であることが好ましい。１０％以上であると、反応性の制御能力が充分に発揮されないことがある。
【００６８】
上記被覆硬化剤における固体硬化剤粒子と微粒子との重量比率は５０：１〜３：１であることが好ましい。固体硬化剤粒子の重量比率が５０を超えると、反応性の制御能力が充分に発揮されないことがあり、３未満であると、微粒子が過剰に存在し、硬化機能が低下することがある。より好ましくは、２０：１〜５：１である。
【００６９】
上記固体硬化剤粒子の表面を微粒子によって被覆させる方法としては特に限定されず、例えば、固体硬化剤粒子と微粒子とを市販のブレンダー等を用いて容器中で混ぜ、均一にする方法等が挙げられる。
【００７０】
上記被覆硬化剤の配合量としては、硬化性樹脂１００重量部に対して１〜１００重量部であることが好ましい。１重量部未満であると、充分に硬化しないことがあり、１００重量部を超えると、過剰の硬化剤が残存するために得られる硬化物の靭性等の諸物性が低下することがある。
【００７１】
上記被覆硬化剤は、硬化性樹脂に配合して硬化性樹脂組成物とした際に、常温保存時は表面の微粒子によって固形硬化剤と硬化性樹脂との接触が極力抑えられるため高い保存安定性を示し、硬化時には温度をかけることにより固形硬化剤が液状となって微粒子に抑制されることなく硬化性樹脂と接触し、硬化反応が速やかに開始する。したがって、硬化性樹脂組成物の保存安定性が向上する。また、上記被覆硬化剤は、特殊な反応を用いずに常温かつ短時間で極めて簡単に製造することが可能である。
【００７２】
本発明の硬化性樹脂組成物は、更に、シランカップリング剤を含有することが好ましい。シランカップリング剤は、主にシール剤又は封口剤と液晶表示素子基板とを良好に接着するための接着助剤としての役割を有する。また、応力分散効果による接着性の改善、線膨張率の改善等のために配合される無機、有機のフィラーとシール剤又は封口剤を構成する樹脂との相互作用を向上させるために、フィラーの表面をシランカップリング剤で処理する方法に用いられることもある。
【００７３】
上記シランカップリング剤としては、下記Ａ群で示される少なくとも１つの官能基と下記Ｂ群で示される少なくとも１つの官能基とを有するシラン化合物が好適に用いられる。
【００７４】
【化３】

【００７５】
上記シラン化合物としては、具体的には例えば、γ−アミノプロピルトリメトキシシラン、γ−メルカプトプロピルトリメトキシシラン、γ−グリシドキシプロピルトリメトキシシラン、γ−イソシアネートプロピルトリメトキシシラン等が挙げられる。これらのシラン化合物は単独で用いてもよく、２種以上を併用してもよい。
【００７６】
かかる構造のシラン化合物をシランカップリング剤として用いることにより本発明の硬化性樹脂組成物は、基板との接着性を向上することができるとともに、Ｂ群で示される官能基を介してシラン化合物が硬化性樹脂と化学結合することにより、液晶中への流出を防止することができる。
【００７７】
上記シラン化合物を配合した後には、加熱処理が行われる。加熱処理により、上記シラン化合物が硬化性樹脂成分とＢ群で示される官能基を介して化学結合する。上記加熱処理については、反応の効率を上げるため樹脂混合物を攪拌することによって行うことが好ましい。攪拌の方法は特に限定されず、例えば、スターラーや攪拌用の羽をモーター等で回転させたりする等の一般的な方法が挙げられる。加熱処理の温度は３０〜７０℃が好ましい。３０℃未満であると、シラン化合物と硬化性樹脂との反応が充分に起こらないことがあり、７０℃を超えると、熱による硬化が始まってしまう恐れがある。より好ましくは４０〜６０℃である。加熱処理の時間は１〜２時間が好ましい。１時間未満であると、シラン化合物中の官能基がすべて反応せずに未反応物が残留してしまう恐れがある。
【００７８】
加熱処理後における上記Ｂ群で示される少なくとも１つの官能基の残存率は、１０％以下である。１０％を超えると、保存中に樹脂成分と反応して増粘したり、液晶中に流出して汚染したりする。なお、Ｂ群で示される少なくとも１つの官能基の残存率は、^１Ｈ−ＮＭＲ測定によって、シラン化合物中の各種官能基のピークの強度と加熱処理後のピーク強度の相対比から求めらことができる。
【００７９】
本発明の硬化性樹脂組成物には、また、スペーサー基を介してイミダゾール骨格とアルコキシシリル基とが結合した構造を有するイミダゾールシラン化合物からなるシランカップリング剤を配合することが好ましい。イミダゾール構造は室温程度の保存温度では硬化性樹脂と殆ど反応性を示さないが、温度をかけることにより硬化性樹脂との反応性を発現することから、上記シランカップリング剤を配合した本発明の硬化性樹脂組成物は、接着力、保存安定性に優れ、かつ、アウトガスの発生量が極めて少ない、液晶中に溶出しにくいといった液晶低汚染性能を併せ持つものとなる。
【００８０】
上記イミダゾールシラン化合物としては、例えば、下記一般式（６）又は下記一般式（７）で表されるもの等が挙げられる。
【００８１】
【化４】

【００８２】
式中、Ｒ^１〜Ｒ^５はそれぞれ独立して炭化水素基、水素又はヒドロキシメチル基を表す。なかでもＲ^１及びＲ^５は、それぞれ独立して、炭素数が１〜５の炭化水素基、水素、ヒドロキシメチル基等であることが好ましく、合成の容易性からより好ましくは、水素、メチル基、ビニル基、ヒドロキシメチル基等である。また、Ｒ^２は、炭素数が１〜２０の炭化水素基、水素、ヒドロキシメチル基であることが好ましく、合成の容易性からより好ましくは、水素、メチル基、エチル基、ウンデシル基、ヘプタデシル基、フェニル基等である。更に、Ｒ^３及びＲ^４は、それぞれ独立して、炭素数が１〜３のアルキル基であることが好ましく、合成の容易性からより好ましくは、水素、メチル基、エチル基等である。
【００８３】
式中、−ＳＰ−は、エステル基、エーテル基、カーボーネート基、ウレタン基、アミド基、スルホン基、ケトン基、アルキレン基等が導入されてもよい直鎖アルキル基又は分岐アルキル基からなるスペーサー基を表す。なかでも、液晶中への溶出を低減化する点から、ウレタン基が導入されることが好ましい。また、液晶中への溶出を低減化する点から、スペーサー基中の水素原子の一部が高極性の官能基で置換されていることが好ましく、このような置換基としては、例えば、ハロゲン原子、水酸基、メルカプト基、カルボキシル基、アミノ基等が挙げられる。更に、−ＳＰ−で表されるスペーサー基は、スペーサー基の主鎖を構成する原子数が１〜２０であることが好ましい。１未満であると、沸点が低下しアウトガスとなりやすく、液晶汚染を引き起こしやすくなることがあり、２０を超えると、粘度が高くなってしまい扱いにくくなったり、アルコキシシラン当量が小さくなるため添加量を増加させないと効果が表れにくくなったりすることがある。より好ましくは３〜１０である。
【００８４】
上記一般式（６）又は一般式（７）で表される化合物としては、具体的には、例えば、下記式（８）又は下記式（９）で表される化合物等が挙げられる。
【００８５】
【化５】

【００８６】
上記式（８）で表される化合物の製造方法としては、例えば、２，４−ジメチルイミダゾールとγ−グリシドキシプロピルトリメトキシシランとを反応させる方法等が挙げられる。また、上記式（９）で表される化合物の製造方法としては、例えば、２−フェニル−３−メチル−５−ヒドロキシメチルイミダゾールとγ−イソシアネートプロピルトリメトキシシランとを反応させる方法等が挙げられる。
【００８７】
上記イミダゾールシラン化合物の配合量としては、硬化性樹脂１００重量部に対して０．１〜１５重量部が好ましい。０．１重量部未満であると、充分な接着力が発揮されないことがあり、１５重量部を超えると、貯蔵安定性が低下することがある。
【００８８】
本発明の硬化性樹脂組成物は、更に、スペーサー基を介してイミダゾール骨格とアルコキシシリル基とが結合した構造を有するイミダゾールシラン化合物、エポキシシラン化合物、及び、アミノシラン化合物からなる群より選択される少なくとも１つにより表面処理されたフィラーを含有することが好ましい。フィラーを配合することにより、応力分散効果による接着性の改善及び線膨張率の改善等の効果が得られる。更に、フィラーの表面を、スペーサー基を介してイミダゾール骨格とアルコキシシリル基とが結合した構造を有するイミダゾールシラン化合物、エポキシシラン化合物、アミノシラン化合物等のシランカップリング剤で処理することにより、フィラーと硬化性樹脂との親和性を高めることができるとともに、これらのシランカップリング剤が液晶中に溶出して汚染することもない。
【００８９】
上記フィラーとしては特に限定されず、例えば、シリカ、珪藻土、アルミナ、酸化亜鉛、酸化鉄、酸化マグネシウム、酸化錫、酸化チタン、水酸化マグネシウム、水酸化アルミニウム、炭酸マグネシウム、硫酸バリウム、石膏、珪酸カルシウム、タルク、ガラスビーズ、セリサイト活性白土、ベントナイト、窒化アルミニウム、窒化珪素等の無機フィラー；ポリエステル微粒子、ポリウレタン微粒子、ビニル重合体微粒子、ゴム微粒子等の有機フィラーが挙げられる。
【００９０】
上記フィラーの形状としては、特に限定されず、球状、針状、板状等の定型物または非定型物が挙げられる。
【００９１】
上記フィラーに対するイミダゾールシラン化合物等の処理量としては、フィラー１００重量部に対して、イミダゾールシラン０．０５重量部〜５重量部であることが好ましい。０．０５重量部未満であると、充分に表面処理されず硬化性樹脂との作用が不充分となることがあり、５重量部を超えると、余剰のイミダゾールシランによってフィラーが凝集してしまい、扱い難くなることがある。より好ましくは０．１〜１重量部である。
【００９２】
上記フィラーの表面処理方法としては特に限定されず、例えば、イミダゾールシラン化合物等を一定のｐＨ（酸性）の水に溶解し加水分解させた溶液とフィラーを反応させる方法により得ることができる。
【００９３】
上記イミダゾールシラン化合物により表面処理されたフィラーの配合量は、硬化性樹脂１００重量部に対して５〜１００重量部であることが好ましい。５重量部未満であると、充分な応力分散効果による接着性の改善、線膨張率の改善等の効果が発揮されないことがあり、１００重量部を超えると、著しく粘度が上昇してしまうことがある。より好ましくは１０〜５０重量部である。
【００９４】
本発明の硬化性樹脂組成物からイオン性の不純物を除去し、上述の性能を満たすようにするためには、少なくとも、イオン吸着性固体と硬化性樹脂組成物とを接触させる工程１と、イオン吸着性固体と硬化性樹脂組成物とを分離する工程２とを有する製造方法により製造することが好ましい。
【００９５】
上記イオン吸着性固体とは、接着剤中に存在するイオン性不純物を吸着することが可能な物であれば特に限定されないが、例えば、下記一般式（１０）で表される化合物からなるものが好ましい。
Ｘ_ｍＹ_ｎ（Ｚ_ｐＯ_ｑ）Ｗ_ｒ・ｓＨ_２Ｏ （１０）
式中、ＸはＮａ^＋、Ｋ^＋又はＣａ^２＋を表し、ＹはＭｇ^２＋、Ｆｅ^２＋、Ａｌ^３＋、Ｆｅ^３＋、Ｔｉ^４＋又はＭｎ^２＋を表し、ＺはＳｉ^４＋、Ａｌ^３＋を表し、ＷはＯＨ⁻、Ｃｌ⁻、Ｆ⁻、ＣＯ_３ ^２−を表す。ｍ、ｎ、ｐ、ｑ、ｒ、ｓは０以上の整数を表す。また、ｍ、ｎ、ｐ、ｑ、ｒ、ｓは、下記式（１１）を満たすことが好ましい。
２ｑ＋ｒａ＝ｍａ＋ｎａ＋ｐａ （１１）
式中、ｒａ、ｍａ、ｎａ、ｐａは、それぞれｒ、ｍ、ｎ、ｐに上記一般式（１０）のイオンの電荷をかけた値を表す。
【００９６】
上記イオン吸着性固体としては、アルミニウム元素を含有するものが好ましく、Ａｌ^３＋を含有するものがより好ましい。Ａｌ^３＋の含有量は、上記一般式（１０）中のＹとＺを合わせたイオン原子数のうち、５〜８０モル％がＡｌ^３＋であることが好ましい。５モル％未満であると、イオン吸着量が低くなることがあり、８０モル％を超えると、Ａｌ^３＋が、溶け出しやすくなることがある。
【００９７】
上記イオン吸着性固体としては、層状無機化合物を用いることが好ましい。上記層状無機化合物とは、一定の性質を持つ積層構造単位を有し、隙間構造を持つため、設計性や機能付与性が高く、また２次元的物性やイオン交換等の特異な性質や機能を有しているものである。
【００９８】
層状無機化合物を用いることによって、層状無機化合物の層間に存在する金属原子がイオン性不純物を捕捉し、また層状構造であるため一端捕捉吸着したイオン性不純物が再溶出しにくい。
【００９９】
上記層状無機化合物としては、層状珪酸塩鉱物であることが好ましい。
上記層状珪酸塩鉱物としては、例えば、ハイドロタルサイト族化合物、蛇紋石−カオリン族化合物、タルク−パイロフィライト族化合物、スメクタイト族化合物、バーミキュライト族化合物、雲母族、層間欠損型雲母化合物、脆雲母族化合物、緑泥石族化合物、混合層鉱物、硅藻土、ケイ酸アルミ等が挙げられ、好ましくは、ハイドロタルサイト族化合物、蛇紋石−カオリン族化合物である。なかでも、アルミニウム元素量が上記範囲にあるものがより好ましく、ハイドロタルサイト族化合物、蛇紋石−カオリン族化合物であってアルミニウム元素量が上記範囲にあるものが更に好ましい。上記層状珪酸塩鉱物は、天然に産出される物であってもよく、合成された物であってもよい。これらの層状珪酸塩鉱物は単独で用いてもよく、２種以上を併用してもよい。
【０１００】
上記ハイドロタルサイト族化合物としては、下記一般式（１２）で表されるものが好ましく、なかでも、Ｍｇ_６Ａｌ_２（ＯＨ）_１６ＣＯ_３・４Ｈ_２Ｏが好適である。
Ｍｇ_ｎ１Ａｌ_ｎ２（ＯＨ）_ｒ１（ＣＯ_３）_ｒ２・ｓＨ_２Ｏ （１２）
式中、ｎ１、ｎ２、ｒ１、ｒ２は１以上の整数を表し、かつ、上記一般式（１０）及び一般式（１１）との関係においてｎ＝ｎ１＋ｎ２、ｒ＝ｒ１＋ｒ２を満たす。
【０１０１】
上記蛇紋石−カオリン族化合物としては、例えば、リザーダイト、バーチェリン、アメサイト、クロンステダイト、ネポーアイト、ケリアイト、フレイポナイト、ブリンドリアイト、カオリナイト、ディカイト、ナクライト、ハロサイト（板状）、オーディナイト等が挙げられる。
【０１０２】
上記タルク−パイロフィライト族化合物としては、例えば、タルク、ウィレムサイト、ケロライト、ピメライト、パイロフィラィライト、フェリパイロフィライト等が挙げられる。
【０１０３】
上記スメクタイト族化合物としては、例えば、サポイナイト、ヘクトライト、ソーコナイト、スチーブンサイト、スインホルダイト、モンモリロナイト、バイデライト、ノントロナイト、ボルコンスコアイト等が挙げられる。
上記バーミキュライト族化合物としては、例えば、３八面体型バーミキュライト、２八面体型バーミキュライト等が挙げられる。
【０１０４】
上記雲母族化合物としては、例えば、黒雲母、金雲母、鉄雲母、イーストナイト、シデロフィライトテトラフェリ鉄雲母、鱗雲母、ポリリシオナイト、白雲母、セラドン石、鉄セラドン石、鉄アルミノセラドン石、アルミノセラドン石、砥部雲母、ソーダ雲母等が挙げられる。
【０１０５】
上記層間欠損型雲母化合物としては、例えば、２八面体型（イライト、海緑石、ブラマーライト）、３八面体型（ウォンネサイト）等が挙げられる。
上記脆雲母族化合物としては、例えば、クリントナイト、木下、ビデ雲母、アナンダ石、真珠雲母等が挙げられる。
上記緑泥石族化合物としては、クリノクロア、シャモサイト、ペナンタイト、ニマイト、ベイリクロア、ドンバサイト、クッケアイト、スドーアイト等が挙げられる。
上記混合層鉱物としては、例えば、コレンサイト、ハイドロバイオタイト、アリエッタイト、クルケアイト、レクトライト、トスダイト、ドジライト、ルニジャンライト、サライオタイト等が挙げられる。
【０１０６】
上記イオン吸着性固体は、硬化性樹脂組成物と接触後に容易に分離できるように、粒状固体であることが好ましい。また、上記イオン吸着性固体の形状としては特に限定されず、その粒子径は回収するイオン性不純物との接触機会を多くする目的からも小さい方が好ましいが、濾過時に目詰まり等の問題となるので、２μｍ以上であることが好ましい。
【０１０７】
上記工程１において、上記イオン吸着性固体と硬化性樹脂組成物とを接触させる方法としては特に限定されず、例えば、攪拌装置、遊星式攪拌装置、プライマリーミキサー等を用いて混合する方法；イオン吸着性固体をカラムに充填しこれに硬化性樹脂組成物を通過させる方法等が挙げられる。また、工程１においては、イオン吸着性固体と硬化性樹脂組成物とを４０〜１００℃で加熱しながら接触させることが好ましい。４０℃未満であると、イオン交換性固体の表面活性が上がりにくく、イオン性不純物が除去されにくいことがある。１００℃を超えると、対象となる硬化性樹脂組成物が増粘してしまうことがある。より好ましくは６０〜８０℃である。なお、混合法によりイオン吸着性固体と硬化性樹脂組成物とを接触させる場合には、イオン吸着性固体の添加量は、イオン性不純物の量や種類により適宜選択することができるが硬化性樹脂組成物１００重量部に対して２〜２０重量部であることが好ましい。２重量部未満であると、イオン性不純物を吸着する能力が不足して効果が得られないことがあり、２０重量部を超えると、イオン吸着性固体が余って無駄になるだけでなく、混合物の粘度が高くなるために濾過に時間がかかることがある。より好ましくは７〜１５重量部である。
【０１０８】
上記工程２において、上記イオン吸着性固体と硬化性樹脂組成物とを分離する方法としては特に限定されず、例えば、濾過、遠心分離等が挙げられる。
本発明の硬化性樹脂組成物の製造方法においては、イオン吸着性固体と硬化性樹脂組成物とを混合後、イオン吸着性固体を回収し、精製することによってイオン性不純物を除去することが好ましい。イオン吸着性固体を回収せず、そのまま残留させると、精製したイオン性不純物が高温高湿等の耐候性試験で、再度溶出してくることがある。
【０１０９】
このような製造方法により製造された硬化性樹脂組成物は、ナトリウムイオン、カリウムイオン、塩素イオン、アクリル酸、メタアクリル酸等のイオン性不純物が取り除かれており、これらが液晶中に流出するのを防止することができる。
【０１１０】
本発明の硬化性樹脂組成物を用いてなる表示素子用シール剤及び表示素子用封口剤もまた、本発明の１つである。
本発明の表示素子用シール剤及び本発明の表示素子用封口剤は、本発明の硬化性樹脂組成物を用いてなることから、保存安定性が極めて高く、また、硬化前、硬化後に係わらず液晶中に成分が流出して液晶を汚染することがない。
【０１１１】
本発明の表示素子用シール剤及び本発明の表示素子用封口剤を用いて表示素子を製造する方法としては特に限定されず、例えば、以下の方法により製造することができる。
【０１１２】
まず、ＩＴＯ薄膜等の２枚の電極付き透明基板（無機ガラス又はプラスチック板）の何れか一方に、本発明の液晶表示素子用シール剤を液晶注入口が解放された所定のパターンとなるように塗布する。塗布方法としては、スクリーン印刷、ディスペンサー塗布等が挙げられる。上記２枚の透明基板をスペーサーを介して対向させ、位置合わせを行いながら重ね合わせる。その後、透明基板のシール部に紫外線を照射して仮留めし、更に１００〜２００℃のオーブン中で１時間加熱硬化させて硬化を完了させる。最後に液晶注入口より液晶を注入し、本発明の液晶表示素子用封口剤を用いて注入口を塞ぎ、液晶表示セルを作製する。
【０１１３】
また、滴下工法による液晶表示素子の製造方法としては、例えば、ＩＴＯ薄膜等の２枚の電極付き透明基板の一方に、本発明の液晶表示素子用シール剤をスクリーン印刷、ディスペンサー塗布等により長方形状のシールパターンを形成する。次いで、シール剤未硬化の状態で液晶の微小滴を透明基板の枠内全面に滴下塗布し、すぐに他方の透明基板を重ねあわせ、シール部に紫外線を照射して仮硬化を行う。その後、液晶アニール時に加熱して本硬化を行い、液晶表示素子を作製する。
【０１１４】
かかる本発明の表示素子用シール剤及び／又は本発明の表示素子用封口剤を用いてなる表示素子もまた、本発明の１つである。
【０１１５】
また、本発明の硬化性樹脂組成物は、有機ＥＬディスプレイの製造における封止缶の取り付け用のシール剤にも好適に用いることができる。図３に有機ＥＬディスプレイの模式図を示した。
有機ＥＬディスプレイでは水分や高エネルギー粒子に弱い低分子有機材料を使用した膜面で構成されていることから、成膜された膜面を覆うように金属、ガラス、金属蒸着フィルム等からなる封止缶が必要になる。このとき、封止缶の取り付けまでは真空中で行い、封止缶の取り付け時には封止缶内を窒素パージを行い、内外気圧差をなくすことにより大気の侵入を防止することで内部への水分の侵入を防止する。例えば、封止缶は、１枚のガラス基板に発光層の膜面を遮光するようにアルミ蒸着させたマスクを形成してシール剤のパターニング部分だけ紫外線が透過するようにして、貼り合わせてもよい。次に、ガラス基板と封止缶とをシール剤により接着し封止する。したがって、シール剤には透湿しないことが求められる。
【０１１６】
次に有機ＥＬディスプレイの製造方法について概説する。使用する基板は、ＴＦＴ等のスイッチング素子の形成された膜面を持つ基板であり、最表面にスパッタによりＩＴＯ膜が形成されている。まず、この基板に接合表面電位とホール層表面電位に整合させるための前処理として、ＵＶ光源からの真空紫外線によるオゾンを発生させ、ガラス基板に形成されたＩＴＯ薄膜の透明電極表面を酸化させる。次に、発光表示層の形成について図１にもとづき説明する。ＩＴＯ膜周辺をＳｉＯ_２膜で囲むようにＣＶＤスパッタする。そしてこのＳｉＯ_２膜上にＰＩ膜によりサブピクセルとなる発光表示層を囲む壁を設ける。次に、図２（１）をもとに有機発光層について説明する。この基板上に有機発光層を形成するが、この工程から発光層の封止までは大気にさらさずに処理することが必要であるので窒素雰囲気及び真空中で一連の操作を実施する。まず、ＩＴＯ膜上に芳香族アミン系材料による正孔注入層の膜を形成する。その上にジアミン誘導体による正孔輸送層をインクジェット印刷により形成し加熱架橋させ、その上に発光層を同じくインクジェットにて形成し、窒素雰囲気中で加熱焼成する。この上に電子輸送発光材料であるＡｌｑ３を蒸着積層して、更に陰極としてＡｌ−Ｌｉを蒸着により形成し成膜が完了する。次に、成膜層を大気から遮断するために封止缶を成膜基板に取り付ける封止工程に入る。まず、水分や他のエネルギーを遮断するための封止缶にシール剤をディスペンサーにより塗布する。このときの塗布条件は液晶パネル作製時と同じであり、封止缶の周辺部を囲うようにシール材を切目なく塗布する。この後シール剤に含まれる気泡の脱泡のため封止缶ごと真空度０．１Ｐａ雰囲気下で真空脱泡し、その後貼り合わせ工程に入る。この工程は大気と遮断しながら封止を行うため、窒素雰囲気中で成膜基板の有機発光層を囲むように封止缶を貼り合わせ、有機ＥＬディスプレイを作製する。
【０１１７】
【実施例】
以下に実施例を掲げて本発明を更に詳しく説明するが、本発明はこれら実施例のみに限定されるものではない。
【０１１８】
（Ａ）アクリル酸変性フェノールノボラックエポキシ樹脂の合成
液状のフェノールノボラック型エポキシ樹脂（ダウケミカル社製：Ｄ．Ｅ．Ｎ．４３１）１０００重量部、重合禁止剤としてｐ−メトキシフェノール２重量部、反応触媒としてトリエチルアミン２重量部、アクリル酸２００重量部を空気を送り込みながら、９０℃で還流攪拌しながら５時間反応させた。得られた樹脂１００重量部を、反応物中のイオン性不純物を吸着させる為にクオルツとカオリンの天然結合物（ホフマンミネラル社製、シリチンＶ８５）１０重量部が充填されたカラムで濾過し、アクリル酸変性フェノールノボラックエポキシ樹脂（５０％部分アクリル化物）を得た。
【０１１９】
（Ｂ）アクリル酸変性プロピレンオキサイドビスフェノールＡエポキシ樹脂の合成
液状のポリオキシアルキレンビスフェノールＡジグリシジルエーテル（旭電化工業社製、ＥＰ４０００Ｓ）１４４０重量部、重合禁止剤としてｐ−メトキシフェノール２重量部、反応触媒としてトリエチルアミン２重量部、アクリル酸２００重量部を空気を送り込みながら、９０℃で還流攪拌しながら５時間反応させた。得られた樹脂１００重量部を、反応物中のイオン性不純物を吸着させる為にクオルツとカオリンの天然結合物（ホフマンミネラル社製、シリチンＶ８５）１０重量部が充填されたカラムで濾過し、アクリル酸変性プロピレンオキサイドビスフェノールＡエポキシ樹脂（５０％部分アクリル化物）を得た。
【０１２０】
（Ｃ）ウレタン変性部分アクリル化物の合成
トリメチロールプロパン１３４重量部、重合開始剤としてＢＨＴ０．２重量部、反応触媒としてジブチル錫ジラウリレート０．０１重量部、イソホロンジイソシアネート６６６重量部を加え、６０℃で還流攪拌しながら２時間反応させた。次に、２−ヒドロキシエチルアクリレート２５．５重量部及びグリシドール１１１重量部を加え、空気を送り込みながら９０℃で還流攪拌しながら２時間反応させた。得られた樹脂１００重量部を、反応物中のイオン性不純物を吸着させる為にクオルツとカオリンの天然結合物（ホフマンミネラル社製、シリチンＶ８５）１０重量部が充填されたカラムで濾過し、ウレタン変性部分アクリル化物を得た。
【０１２１】
（実施例１）
（Ａ）で得られたアクリル酸変性フェノールノボラックエポキシ樹脂４０重量部、（Ｃ）で得られたウレタン変性部分アクリル化物２０重量部、潜在性熱硬化剤としてヒドラジド系硬化剤（味の素ファインテクノ社製、アミキュアＶＤＨ）１５重量部、光重合開始剤として２，２−ジエトキシアセトフェノン１重量部、シリカ粒子（平均粒径１．５μｍ）２３重量部、γ−グリシドキシプロピルトリメトキシシラン１重量部からなる硬化性樹脂組成物を均一な液となるように三本ロールを用いて充分に混合し、シール剤を得た。
【０１２２】
また、透明電極付きの２枚の透明基板の一方に、得られたシール剤を長方形の枠を描く様にディスペンサーで塗布した。続いて、液晶（チッソ社製、ＪＣ−５００４ＬＡ）の微小滴を透明基板の枠内全面に滴下塗布し、直ぐに他方の透明基板を重ねあわせてシール部に高圧水銀ランプを用い紫外線を５０ｍＷ／ｃｍ^２で６０秒照射した。その後、液晶アニールを１２０℃にて１時間行い熱硬化させ、液晶表示セルを作製した。
【０１２３】
（実施例２）
（Ｃ）で得られたウレタン変性部分アクリル化物２０重量部の代わりに、（Ｂ）で得られたプロピレンオキサイド部分アクリル化物２０重量部を用い、ヒドラジド系硬化剤（味の素ファインテクノ社製、アミキュアＶＤＨ）１５重量部の代わりに、ヒドラジド系硬化剤（日本ヒドラジン工業社製、ＮＤＨ）１５重量部を用いた以外は実施例１と同様にしてシール剤を得、これを用いて液晶表示セルを作製した。
【０１２４】
（比較例１）
ウレタンアクリレート（共栄社化学社製、ＡＨ−６００）３５重量部、２−ヒドロキシブチルアクリレート１５重量部、イソボニルアクリレート５０重量部、ベンゾフェノン３重量部からなる硬化性樹脂組成物を均一な液となるように混合し、光硬化型のシール剤を得、これを用いて液晶表示セルを作製した。
【０１２５】
（比較例２）
ビスフェノールＡ型エポキシ樹脂（ジャパンエポキシレジン社製、エピコート８２８１ＪＥＲ）３５重量部、ビスフェノールＡ型エポキシアクリル樹脂（ダイセルＵＣＢ社製、ＥＢ３７００）３５重量部、シリカ２０重量部、シランカップリング剤（エポキシシラン、信越化学社製、ＫＢＭ４０３）５重量部、光重合開始剤（チバスペシャリティ社製、ＩＲ−６５１）２．５重量部、下記式に表す光カチオン重合開始剤２．５重量部からなる硬化性樹脂組成物を均一な液となるように三本ロールを用いて充分に混合し、シール剤を得、これを用いて液晶表示セルを作製した。
【０１２６】
【化６】

【０１２７】
（比較例３）
ビスフェノールＡエポキシ樹脂（ジャパンエポキシレジン社製、エピコート８２８ＵＳ）５０重量部、ヒドラジド系硬化剤（日本ヒドラジン工業社製、ＮＤＨ）２５重量部からなる硬化性樹脂組成物を均一な液となるように三本ロールを用いて充分に混合し、シール剤を得、これを用いて液晶表示セルを作製した。
【０１２８】
実施例１、２及び比較例１〜３で作製したシール剤について、下記の方法により比抵抗値、ゲル分率、ガラス転移温度、体積抵抗値、１００ｋＨｚにおける誘電率、貯蔵安定性を評価し、また、得られた液晶表示セルについて下記の方法により色むらを評価した。
結果を表１に示した。
【０１２９】
（硬化前のシール剤の比抵抗値）
硬化前のシール剤について、標準温度湿度状態（２０℃、６５％ＲＨ）で、比抵抗測定器（東洋テクニカ社製、ＳＲ−６５１７型）と液体用電極（安藤電気社製、ＬＥ−２１型）を用いて比抵抗値の測定を行った。
【０１３０】
（シール剤のゲル分率）
熱硬化条件；１２０℃１時間にて熱処理を行い硬化させた。
光硬化条件；５０ｍＷ／ｃｍ^２で６０秒間（３０００ｍＪ／ｃｍ^２）光照射を行ない硬化させた。
硬化させたシール剤を室温で２４時間アセトンに浸漬し、浸漬前後の乾燥重量を求め、下記式により算出した。
ゲル分率（％）＝浸漬後乾燥重量／浸漬前乾燥重量×１００
【０１３１】
（シール剤のガラス転移温度）
ＤＭＡ法により、昇温速度５℃／分、周波数１０Ｈｚの条件にて測定を行った。測定は遮光部で行った。
【０１３２】
（硬化後のシール剤の体積抵抗値）
クロム蒸着ガラス基板のクロム蒸着面上にシール剤を薄く均一に塗布した後紫外線硬化して、大きさ８５ｍｍ×８５ｍｍ、厚さ３ｍの紫外線硬化物を形成し、この上にクロム蒸着面を紫外線硬化物側にしてクロム蒸着ガラス基板を載せて荷重をかけて、１２０℃のホットプレート上で１時間加熱圧着し、試験サンプルを作製した。この試験サンプルにおけるシール剤の面積（Ｓ（ｃｍ^２））、対向するクロム蒸着ガラス基板のクロム蒸着面間に定電圧発生装置（ケンウッド社製、ＰＡ３６−２ＡレギュレーテッドＤＣパワーサプライ）を用いて一定の電圧（Ｖ（Ｖ））を印加し、膜に流れる電圧（Ａ（Ａ））を電流計（アドバンテスト社製、Ｒ６４４Ｃデジタルマルチメーター）にて測定した。シール剤の膜圧（Ｔ（ｃｍ））としたとき、下記式により体積抵抗率（Ω・ｃｍ）を求めた。
体積抵抗率（Ω・ｃｍ）＝（Ｖ・Ｓ）／（Ａ・Ｔ）
ただし、印加電圧は直流５００Ｖ、導電時間は１分間とした。
【０１３３】
（硬化後のシール剤の１００ｋＨｚにおける誘電率）
ガラスプレート上にシール剤を薄く均一に塗布した後硬化して、大きさ６０ｍｍ×６０ｍｍ、厚さ３ｍの試験片を作製した。ＡＳＴＭ Ｄ１５０に準じる方法により、電極非接触法（間隙法）により、誘電体測定用電極（横河ＨＰ社製、ＨＰ１６４５１Ｂ）、ＬＣＲメータ（ヒューレットパッカード社製、４２８４Ａ）を用いて周波数１００ｋＨｚで測定した。
【０１３４】
（貯蔵安定性評価）
硬化前のシール剤を室温で１週間保存後にＥ型粘度計で測定した粘度が、初期の粘度の２倍以内である場合を○、２倍以上である場合を×として評価を行った。
【０１３５】
（色むら評価）
得られた液晶表示セルについて、６０℃、９５％ＲＨ、５００時間放置前後に、シール部周辺の液晶に生じる色むらを目視で観察し、◎（色むらが全くない）、○（色むらが微かにある）、△（色むらが少しある）、×（色むらがかなりある）の４段階で液晶汚染性の評価を行った。なお、ここでは１区につきサンプル数５で行った。
【０１３６】
【表１】

【０１３７】
【発明の効果】
本発明によれば、液晶表示素子の製造において液晶表示素子用シール剤又は液晶表示素子用封口剤として用いた場合に、その成分が液晶材料中に溶け出して液晶汚染を引き起こすことがないため液晶表示において色むらが少なく、かつ、貯蔵安定性に優れることから、特に液晶滴下工法による表示素子の製造に最適である硬化性樹脂組成物、これを用いた表示素子用シール剤、表示素子用封口剤を提供できる。
【図面の簡単な説明】
【図１】有機ＥＬディスプレイの製造方法における発光表示層の形成を説明する模式図である。
【図２】有機ＥＬディスプレイの製造方法における有機発光層の形成を説明する模式図である。
【図３】有機ＥＬディスプレイの構造を示す模式図である。[0001]
TECHNICAL FIELD OF THE INVENTION
When the present invention is used as a sealant for a liquid crystal display element or a sealing agent for a liquid crystal display element in a liquid crystal display element, the component does not dissolve into the liquid crystal material and does not cause liquid crystal contamination, so that color unevenness in the liquid crystal display is prevented. Is low, and, because of its excellent storage stability, a curable resin composition which is particularly suitable for a display element by a liquid crystal dropping method, a sealant for a display element using the same, a sealant for a display element, and these The present invention relates to a display element used.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a liquid crystal display element such as a liquid crystal display cell, a transparent substrate with two electrodes is opposed to each other at a predetermined interval, the periphery thereof is sealed with a sealant to form a cell, and provided on a part thereof. Liquid crystal was injected into the cell from the liquid crystal injection port thus obtained, and the liquid crystal injection port was sealed using a sealing agent or a sealing agent.
[0003]
In this method, first, a seal pattern provided with a liquid crystal injection port using a thermosetting sealant is formed on one of two transparent substrates with electrodes by screen printing, and prebaked at 60 to 100 ° C. The solvent in the sealant is dried. Next, two substrates are opposed to each other with a spacer interposed therebetween, aligned and bonded, and hot-pressed at 110 to 220 ° C. for 10 to 90 minutes to adjust the gap near the seal, and then heated at 110 to 220 ° C. in an oven. The sealant is fully cured by heating for 10 to 120 minutes. Next, liquid crystal was injected from the liquid crystal injection port, and finally, the liquid crystal injection port was sealed with a sealing agent to produce a liquid crystal display element.
[0004]
However, according to this manufacturing method, misalignment, gap variation, decrease in adhesion between the sealant and the substrate, etc. occur due to thermal strain; the residual solvent thermally expands to generate bubbles, resulting in gap variation and seal path. The seal baking time is long; the pre-bake process is complicated; the usable time of the sealant is short due to evaporation of the solvent; and it takes time to inject the liquid crystal. In particular, in recent large-sized liquid crystal display elements, it has been a serious problem that it takes a very long time to inject liquid crystal.
[0005]
On the other hand, a method of manufacturing a liquid crystal display element called a liquid crystal dropping method using a light-curing and heat-curing combined sealant is being studied. In the liquid crystal dropping method, first, a rectangular seal pattern is formed on one of two transparent substrates with electrodes by dispenser printing. Next, a liquid crystal microdroplet is applied to the entire surface of the frame of the transparent substrate in a state where the sealing agent is not cured, and the other transparent substrate is immediately overlapped, and the sealing portion is irradiated with ultraviolet rays to perform temporary curing. After that, heating is performed during liquid crystal annealing to perform main curing, and a liquid crystal display element is manufactured. If the substrates are bonded under reduced pressure, a liquid crystal display device can be manufactured with extremely high efficiency. It is expected that this liquid crystal dropping method will become the mainstream of the liquid crystal display element manufacturing method in the future.
[0006]
As a sealant used in the conventional method, for example, Patent Literature 1 discloses an adhesive mainly composed of a partially (meth) acrylated bisphenol A type epoxy resin. Patent Document 2, Patent Document 3, Patent Document 4, Patent Document 5 and the like disclose, and Patent Document 4 discloses a liquid crystal sealant containing (meth) acrylate as a main component.
[0007]
However, these sealants tend to exhibit a polarity value close to that of the liquid crystal material, and both have a property of being compatible with each other. Therefore, in a liquid crystal display element assembled by a dripping method using these sealants, the components of the sealant elute in the liquid crystal, and the alignment of the liquid crystal is disturbed in the peripheral portion of the sealant, resulting in display defects such as color unevenness. May cause. In particular, in the dropping method, since there is a step in which the uncured sealant comes into direct contact with the liquid crystal, liquid crystal contamination by such a sealant component has been a serious problem. Of these, sealants having a thermosetting component have very poor storage stability at room temperature and must be stored frozen.However, moisture may be mixed in at the time of thawing, or they may increase immediately at room temperature once thawed. There is also a problem that it must be used within a short time because it sticks. Furthermore, there is a problem that a sealant that is cured only by light has poor moisture resistance and a low cure rate under a light-shielding portion.
[0008]
In addition, unreacted polymerization initiators and residual substances such as curing agents contained in the cured sealing agent; ionic impurities such as chlorine; and silane coupling agents are also problems. In recent years, liquid crystal panels having a low driving voltage (low-voltage liquid crystal) tend to use liquid crystal because of low power consumption for mobile use and the like. This low-voltage liquid crystal has a large dielectric anisotropy, and thus easily takes in impurities, and tends to cause disorder in alignment and a decrease in voltage holding ratio with time. That is, unreacted polymerization initiator contained in the sealant, residue such as hardening, etc .; ionic impurities such as chlorine; and silane coupling agent incorporated into the liquid crystal can cause disturbance of alignment and a decrease in voltage holding ratio over time. It was a problem to be triggered.
[0009]
On the other hand, techniques for reducing the amount of the polymerization initiator contained in the sealant or increasing the molecular weight of the polymerization initiator have been studied. However, in such a method, not only the elution to the liquid crystal is not sufficiently suppressed, but also the reactivity is reduced, and a large amount of light is required for curing the sealant or the like, which has a problem that the liquid crystal is adversely affected. there were.
[0010]
For ionic impurities, Patent Literature 6 and the like disclose a method for removing ionic impurities by washing a sealant, a sealing agent, and a raw material thereof with water or an organic solvent, and drying under reduced pressure. I have. However, such a method is very complicated, and in addition, when the dried sealing agent or sealing agent is not sufficiently dried, the solvent remains or gelation occurs during the drying step under reduced pressure. There was a problem that would occur.
[0011]
The curable resin composition used for the sealant or the sealing agent is roughly classified into a two-part type in which the main agent and the curing agent are mixed and used, and a one-part type in which the curing agent is blended in advance. You. The two-pack type can be cured at room temperature, but the curable resin (main agent) and the curing agent must be stored separately, and each must be measured and mixed at the time of use, so that storage and handling are complicated. In addition, since the pot life is limited, it is not possible to mix a large amount, and the mixing frequency increases, resulting in low efficiency. On the other hand, in the case of the one-pack type, a reaction may occur during storage, and improvement in storage stability is desired. On the other hand, for example, when the curable resin is an epoxy resin, a one-pack type curable resin composition using dicyandiamide as a curing agent has been known for a long time. However, in this case, a high temperature of 160 ° C. or more is required for curing, and it is no longer possible to cope with low-temperature and short-time curing recently required. Further, as a system capable of curing at a low temperature for a short time, Patent Document 7 discloses a method using an adduct of an amine and an epoxy as a curing agent, Patent Document 8 discloses a method using imidazole encapsulated with polymethyl methacrylate and used as a curing agent, Patent Document 9 proposes a method of inactivating the surface of a powdered amine compound with isocyanate, and the like. However, these methods are very complicated, and there is a problem that unreacted amines and the like are remarkably eluted into a liquid crystal or the like.
[0012]
[Patent Document 1]
JP-A-6-160872
[Patent Document 2]
Japanese Patent Application Laid-Open No. 1-243029
[Patent Document 3]
JP-A-7-13173
[Patent Document 4]
JP-A-7-13174
[Patent Document 5]
JP-A-7-13175
[Patent Document 6]
JP-A-5-295087
[Patent Document 7]
JP-A-62-146915
[Patent Document 8]
JP-A-2-292325
[Patent Document 9]
JP-A-59-59720
[Problems to be solved by the invention]
When the present invention is used as a sealant for a liquid crystal display element or a sealing agent for a liquid crystal display element in a liquid crystal display element, the component does not dissolve into the liquid crystal material and does not cause liquid crystal contamination, so that color unevenness in the liquid crystal display is prevented. Is low, and, because of its excellent storage stability, a curable resin composition which is particularly suitable for a display element by a liquid crystal dropping method, a sealant for a display element using the same, a sealant for a display element, and these It is an object to provide a display element using the same.
[0022]
[Means for Solving the Problems]
The present invention relates to a curable resin composition used as a sealant or a sealing agent for a liquid crystal dropping method, wherein the gel fraction after a thermosetting reaction is 70% or more, and the gel fraction after a photocuring reaction. Is 70% or more of the curable resin composition. That is, the curable resin composition of the present invention can be cured to a gel fraction of 70% or more using light or heat.
Hereinafter, the present invention will be described in detail.
[0023]
The curable resin composition of the present invention is used as a sealant or a sealing agent for a liquid crystal dropping method, and the curable resin composition of the present invention has a gel fraction of 70% or more after a thermosetting reaction. And the gel fraction after the photocuring reaction is 70% or more. If the gel fraction is less than 70%, the curable resin composition may easily elute into the liquid crystal. In particular, the curable resin composition of the present invention has a gel fraction of 70% or more whether the same resin is heat or light. Therefore, even when only heat or light acts on a display element manufacturing process, the curable resin composition is sufficiently cured. can do.
[0024]
The curable resin composition of the present invention preferably has a glass transition temperature of 50 ° C. or higher. When the glass transition temperature is lower than 50 ° C., the moisture resistance (high-temperature high-humidity resistance) may be poor.
[0025]
The glass transition temperature is a value measured by a DMA method at a temperature rising rate of 5 ° C./min and a frequency of 10 Hz. However, since the measurement of the glass transition point temperature by the DMA method requires a large amount of sample, when only a small amount of the sample can be obtained, it is preferable to perform the measurement by the DSC method at a temperature rising rate of 10 ° C./min. . Generally, the glass transition temperature measured by the DSC method is lower by about 30 ° C. than the glass transition temperature measured by the DMA method. Therefore, when the glass transition temperature is measured by the DSC method, it is preferably 20 ° C. or higher.
[0026]
The gel fraction can be determined from the dry weight before and after immersing the curable resin composition of the present invention in acetone at room temperature for 24 hours.
[0027]
The curable resin composition of the present invention preferably has a volume resistivity after curing of 1 × 10 ¹³ Ω · cm or more. When it is less than 1 × 10 ¹³ Ω · cm, it means that the curable resin composition of the present invention contains ionic impurities. Elutes in the liquid crystal, affects the liquid crystal driving voltage, and causes display unevenness.
[0028]
The curable resin composition of the present invention preferably has a specific resistance before curing of 1.0 × 10 ^{6 to} 1.0 × 10 ¹⁰ Ω · cm. When it is less than 1.0 × 10 ⁶ Ω · cm, when these are eluted into the liquid crystal when used as a sealant or a sealing agent, they affect the liquid crystal drive voltage and cause display unevenness. If it exceeds 1.0 × 10 ¹⁰ Ω · cm, elution into the liquid crystal may increase, and adhesion to the substrate may be poor.
[0029]
Such performance of the curable resin composition of the present invention is obtained by using the curable resin described below, and selecting and using a photopolymerization initiator, a curing agent, and a silane coupling agent as necessary. be able to.
[0030]
The curable resin preferably contains, as a main component, a compound having at least one (meth) acryl group and at least one epoxy group in one molecule. A compound having only a ((meth) acrylic group or an epoxy group in one molecule may be contained. By using such a compound as a curable resin, a sealing agent or a sealing agent obtained can be cured by light and heat. Liquid crystal with excellent gap accuracy compared to conventional thermosetting sealants or sealing agents by being able to be used in combination with curing and temporarily preliminarily fixed by light curing and then completely cured by thermosetting. A display element can be manufactured.
In addition, in this specification, (meth) acrylic acid means acrylic acid or methacrylic acid.
[0031]
The compound having at least one or more (meth) acrylic group and one or more epoxy group in one molecule is not particularly limited, and examples thereof include (meth) acrylic acid-modified epoxy resin and urethane-modified (meth) acrylic epoxy resin. No.
[0032]
Examples of the (meth) acrylic acid-modified epoxy resin include those obtained by partially (meth) acrylating a novolak type epoxy resin, a bisphenol type epoxy resin, etc .; biphenyl type epoxy resin, naphthalene type epoxy resin, tris (hydroxyphenyl) alkyl Epoxy resin, tetrakis (hydroxyphenyl) alkyl epoxy resin and the like are preferable.
[0033]
Examples of the epoxy resin as a raw material of the (meth) acrylic acid-modified epoxy resin include, for example, phenol novolak type, cresol novolak type, biphenyl novolak type, trisphenol novolak type, and dicyclopentadiene novolak type as the novolak type. Examples of the bisphenol type include bisphenol A type, bisphenol F type, 2,2′-diallylbisphenol A type, bisphenol S type, hydrogenated bisphenol type, and polyoxypropylene bisphenol A type.
[0034]
Among the raw materials of the above (meth) acrylic acid-modified epoxy resin, commercially available ones, for example, phenol novolac type, such as Epicron N-740, Epicron N-770, Epicron N-775 (these are Dainippon Ink and Chemicals, Inc.) Co., Ltd.), Epicoat 152 and Epicoat 154 (all manufactured by Japan Epoxy Resin Co., Ltd.), and as the cresol novolak type, Epicron N-660, Epicron N-665, Epicron N-670, Epicron N-673, Epicron N -680, Epicron N-695, Epicron N-665-EXP, Epicron N-672-EXP (all manufactured by Dainippon Ink and Chemicals, Inc.) and the like.
[0035]
The partially (meth) acrylated product of the epoxy resin is obtained, for example, by reacting the epoxy resin with (meth) acrylic acid in the presence of a basic catalyst according to a conventional method. An epoxy resin having a desired acrylate ratio can be obtained by appropriately changing the amount of the epoxy resin and the (meth) acrylic acid.
[0036]
The urethane-modified (meth) acrylic epoxy resin is obtained, for example, by the following method. That is, a method of reacting a polyol with a difunctional or more functional isocyanate, and further reacting the polyol with a (meth) acrylic monomer having a hydroxyl group and glycidol; (meth) acrylic having a hydroxyl group on the difunctional or more functional isocyanate without using a polyol. A method of reacting a monomer or glycidol; a method of reacting glycidol with a (meth) acrylate having an isocyanate group, or the like. Specifically, for example, first, 1 mol of trimethylolpropane and 3 mol of isophorone diisocyanate are reacted under a tin-based catalyst, and an isocyanate group remaining in the obtained compound and hydroxyethyl acrylate, which is an acrylic monomer having a hydroxyl group, and It can be produced by reacting with glycidol which is an epoxy having a hydroxyl group.
[0037]
The polyol is not particularly limited, and includes, for example, ethylene glycol, glycerin, sorbitol, trimethylolpropane, (poly) propylene glycol and the like.
[0038]
The isocyanate is not particularly limited as long as it is bifunctional or more. For example, isophorone diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, diphenylmethane-4, 4'-diisocyanate (MDI), hydrogenated MDI, polymeric MDI, 1,5-naphthalenediisocyanate, norbornane diisocyanate, tolidine diisocyanate, xylylene diisocyanate (XDI), hydrogenated XDI, lysine diisocyanate, triphenylmethane triisocyanate , Tris (isocyanatephenyl) thiophosphate, tetramethylxylene diisocyanate, 1,6,10-undecane triisocyanate and the like. I can do it.
[0039]
The (meth) acrylic monomer having a hydroxyl group is not particularly limited, and examples of the monomer having one hydroxyl group in a molecule include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and hydroxybutyl (meth) acrylate Examples of the monomer having two or more hydroxyl groups in the molecule include epoxy (meth) acrylate such as bisphenol A-modified epoxy (meth) acrylate. These may be used alone or in combination of two or more.
[0040]
The mixing ratio of the epoxy group and the (meth) acryl group in the curable resin composition of the present invention is preferably acrylic: epoxy of 4: 6 to 9: 1. When the equivalent ratio of the (meth) acrylic group is less than 4, the photoreactivity decreases, and even if the sealant is irradiated with light after the gap adjustment, not only does the initial temporary hardening disappear, but also the liquid crystal has an adverse effect on the liquid crystal. Elution may be large, and if it exceeds 9, the adhesiveness and moisture permeability may be insufficient. More preferably, the ratio is 5: 5 to 8: 2.
[0041]
The compound having at least one (meth) acryl group and at least one epoxy group in one molecule is preferably a compound having a hydroxyl group and / or a urethane bond from the viewpoint of reducing compatibility with liquid crystals and eliminating contamination. .
[0042]
The curable resin composition of the present invention preferably contains a compound having a hydroxyl group and / or a urethane bond in an amount of 50% by weight or more in the curable resin. When the content is less than 50% by weight, the compatibility with the liquid crystal is high, and the liquid crystal is easily contaminated. A preferred upper limit is 80% by weight.
[0043]
The curable resin composition of the present invention preferably has an aromatic property and contains a compound having a cyclic structure. For example, a benzene skeleton, a biphenyl skeleton, a naphthalene skeleton, a bisphenol skeleton, a novolak skeleton, a resorcinol skeleton are preferable. And compounds having a catechol skeleton, a phenylene ether skeleton, a diphenyl sulfide skeleton, and the like. Thereby, the contamination of the curable resin composition of the present invention can be reduced.
In the case of the compound having no hydroxyl group and / or urethane bond among the curable resin compositions of the present invention, the curable resin composition has the aromaticity and the cyclic structure, and thus the liquid crystal contamination of the curable resin composition. It is preferable because the property is reduced.
[0044]
The compound having at least one (meth) acryl group and at least one epoxy group in one molecule preferably has a number average molecular weight of 300 or more. If it is less than 300, it may be eluted into the liquid crystal and the orientation may be easily disturbed. Further, the number average molecular weight is preferably 3000 or less. If it exceeds 3,000, it may be difficult to adjust the viscosity.
[0045]
When a compound having at least one (meth) acrylic group and at least one epoxy group in one molecule is used as a curable resin, when the curable resin composition of the present invention is cured and the infrared absorption spectrum is measured, An absorption peak of a carbonyl group derived from a (meth) acryl group is observed. When an epoxy group and a hydroxyl group derived from the epoxy group are present, their absorption peaks can also be observed.
[0046]
The photopolymerization initiator is not particularly limited as long as it can polymerize the curable compound component by light irradiation.However, if the photopolymerization initiator described below is used, elution of the photopolymerization initiator into the liquid crystal can be prevented. preferable.
[0047]
The photopolymerization initiator can impart sufficient reactivity when incorporated into the curable resin composition of the present invention, and does not elute into the liquid crystal and contaminate the liquid crystal. Among them, benzoin (ether) compounds having a reactive double bond and a hydroxyl group and / or a urethane bond are preferred. The benzoin (ether) compounds refer to benzoins and benzoin ethers.
[0048]
Examples of the reactive double bond include residues such as an allyl group, a vinyl ether group, and a (meth) acryl group. When the reactive double bond is used as a photopolymerization initiator for a sealing agent or a sealing agent, the reactivity is high. To (meth) acrylic residues are preferred. By having such a reactive double bond, the weather resistance when blended in a sealing agent or a sealing agent is improved.
[0049]
The benzoin (ether) compound only needs to have one of a hydroxyl group and a urethane bond, and may have both. If the benzoin (ether) compound has neither a hydroxyl group nor a urethane bond, it may be eluted into the liquid crystal before curing when blended in a sealant or a sealing agent.
In the benzoin (ether) compound, the reactive double bond and the hydroxyl group and / or urethane bond may be located in any part of the benzoin (ether) skeleton, and are represented by the following general formula (4). Those having a molecular skeleton are preferred. When a compound having such a molecular skeleton is used as a photopolymerization initiator, the amount of residual substances is reduced, and the amount of outgas can be reduced.
[0050]
Embedded image

[0051]
In the formula, R represents hydrogen or an aliphatic hydrocarbon residual chain having 4 or less carbon atoms. When R is a residual aliphatic hydrocarbon chain having more than 4 carbon atoms, the storage stability when a photopolymerization initiator is added increases, but the reactivity may decrease due to steric hindrance of the substituent.
Examples of the benzoin (ether) compound having a molecular skeleton represented by the general formula (4) include a compound represented by the following general formula (5).
[0052]
Embedded image

[0053]
In the formula, R represents hydrogen or an aliphatic hydrocarbon residue having 4 or less carbon atoms, X represents a residue of a bifunctional isocyanate derivative having 13 or less carbon atoms, and Y represents an aliphatic hydrocarbon residue having 4 or less carbon atoms. A residue having an atomic ratio of carbon to oxygen constituting the group or the residue of 3 or less. When X is a residue of a bifunctional isocyanate derivative having more than 13 carbon atoms, it may be easily dissolved in a liquid crystal, and Y may be an aliphatic hydrocarbon group having more than 4 carbon atoms or an atomic ratio of carbon and oxygen of 3 If the number of residues exceeds 3, the compound may be easily dissolved in the liquid crystal.
[0054]
As the above photopolymerization initiator, for example, benzophenone, 2,2-diethoxyacetophenone, benzyl, benzoylisopropyl ether, benzyldimethyl ketal, 1-hydroxycyclohexylphenyl ketone, thioxanthone, or a combination of two or more thereof is used. be able to.
[0055]
The addition amount of the photopolymerization initiator is preferably 0.1 to 10 parts by weight based on 100 parts by weight of the curable resin. If it is less than 0.1 part by weight, the effect of initiating photopolymerization may be insufficient due to insufficient ability, and if it exceeds 10 parts by weight, a large amount of unreacted photopolymerization initiator may remain, The weather resistance may deteriorate. More preferably, it is 1 to 5% by weight.
[0056]
The curing agent is used for causing the epoxy group and / or the acryl group in the curable resin composition to react and to crosslink by heating, and improves the adhesiveness and moisture resistance of the cured curable resin composition after curing. Has a role. As the curing agent, a latent curing agent having a melting point of 100 ° C. or more is suitably used. When a curing agent having a melting point of 100 ° C. or less is used, storage stability may be significantly deteriorated.
[0057]
Examples of such a curing agent include hydrazide compounds such as 1,3-bis [hydrazinocarbonoethyl-5-isopropylhydantoin], dicyandiamide, guanidine derivatives, 1-cyanoethyl-2-phenylimidazole, N- [2- ( 2-methyl-1-imidazolyl) ethyl] urea, 2,4-diamino-6- [2′-methylimidazolyl- (1 ′)]-ethyl-s-triazine, N, N′-bis (2-methyl- 1-imidazolylethyl) urea, N, N '-(2-methyl-1-imidazolylethyl) -adipamide, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole Imidazole derivatives, modified aliphatic polyamines, tetrahydrophthalic anhydride, ethylene glycol bis (A Acid anhydrides such as dihydrotrimellitate) and addition products of various amines with epoxy resins. These may be used alone or in combination of two or more.
[0058]
When the acrylic acid-modified epoxy resin is used as the compound having at least one or more (meth) acrylic group and one or more epoxy group in one molecule, the reactivity of the acrylic epoxy resin changes greatly from its structure, and the urethane-modified epoxy resin changes. In the case of an epoxy resin, storage stability is excellent even when a highly reactive curing agent is used due to its stability. However, in the case of a (meth) acrylic acid-modified epoxy resin, the reactivity is high and the melting point is 100 ° C. or higher. A curing agent having low reactivity is preferable in terms of storage stability.
[0059]
As the compounding ratio of the curing agent, the ratio of the weight of the curable resin / the weight of the curing agent is preferably 3 to 10. Outside of the above ranges, the adhesiveness and chemical resistance of the cured product may be reduced, and the deterioration of the characteristics of the liquid crystal in a high temperature and high humidity operation test may be accelerated.
[0060]
Further, as the curing agent, a coating curing agent in which the surface of solid curing agent particles is covered with fine particles is preferable. If the above coating curing agent is used as a curing agent, very high storage stability can be obtained even as a one-pack type. By using a coated hardener in which the surface of a solid hardener is coated with fine particles having poor volatility and poor solubility in organic substances, a curable resin composition having high storage stability even if a hardener is previously compounded. Things are obtained.
[0061]
In the present specification, the above-mentioned solid curing agent refers to a curing agent which is solid at room temperature, melts or softens by heating, and starts a reaction with the curable resin. The solid curing agent is not particularly limited as long as it has a melting point or a softening point of room temperature or higher, and examples thereof include a solid amine compound, a phenolic compound, and an acid anhydride. Among them, solid amine compounds are preferred because of their excellent low-temperature reactivity.
[0062]
The solid amine compound refers to a solid compound having one or more primary to tertiary amino groups in the molecule, for example, aromatic amines such as metaphenylenediamine and diaminodiphenylmethane, 2-methylimidazole , 1,2-dimethylimidazole, 1-cyanoethyl-2-methylimidazole and the like, imidazoline compounds such as 2-methylimidazoline and the like, dihydrazide compounds such as sebacic acid dihydrazide and isophthalic acid dihydrazide. Among these solid amine compounds, commercially available ones include, for example, amine adducts such as AMICURE PN-23 and AMICURE MY-24 (all manufactured by Ajinomoto Fine Techno Co.), dicyandiamide, and the like. Of these, primary amines and secondary amines are preferred.
[0063]
Examples of the polyhydric phenol compound include a polyphenol compound and a novolak type phenol resin. Among these polyhydric phenol compounds, commercially available compounds include, for example, EpiCure 170, EpiCure YL6065, and EpiCure MP402FPI (all manufactured by Japan Epoxy Resin Co., Ltd.).
[0064]
Examples of the acid anhydride include glycerin bis (anhydrotrimellitate), ethylene glycol bis (anhydrotrimellitate), tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, -Methyltetrahydrophthalic anhydride and the like. Among these acid anhydrides, commercially available ones include, for example, Epicure YH-306 and YH-307 (all manufactured by Japan Epoxy Resin Co., Ltd.).
[0065]
The average particle diameter of the solid curing agent particles is not particularly limited, but is preferably 0.1 to 50 μm. If it is less than 0.1 μm, it may not be possible to efficiently coat the surface with fine particles, and if it is more than 50 μm, precipitation of the curing agent occurs during storage when blended with the curable resin composition, or uneven curing may occur. Sometimes it happens. More preferably, it is 0.5 to 10 μm.
[0066]
Examples of the fine particles for coating the surface of the solid hardener particles include oxides such as Si, Al, Ti, Fe, Mn, and Mg, hydroxides, halides, styrene beads, and fine rubber particles. These fine particles may be used alone or in combination of two or more.
[0067]
The average particle diameter of the fine particles is preferably 0.05 μm or less. If it exceeds 0.05 μm, the surface of the solid curing agent particles may not be efficiently coated. More preferably, it is 0.03 μm or less. Further, the particle diameter of the fine particles is preferably 10% or less of the particle diameter of the solid curing agent particles. If it is 10% or more, the controllability of reactivity may not be sufficiently exhibited.
[0068]
The weight ratio of the solid curing agent particles to the fine particles in the coating curing agent is preferably 50: 1 to 3: 1. If the weight ratio of the solid curing agent particles exceeds 50, the controllability of reactivity may not be sufficiently exhibited, and if it is less than 3, fine particles may be excessively present and the curing function may be reduced. More preferably, it is 20: 1 to 5: 1.
[0069]
The method of coating the surface of the solid hardener particles with the fine particles is not particularly limited, and examples thereof include a method of mixing the solid hardener particles and the fine particles in a container using a commercially available blender or the like to make them uniform. .
[0070]
The amount of the coating curing agent is preferably 1 to 100 parts by weight based on 100 parts by weight of the curable resin. If the amount is less than 1 part by weight, the composition may not be cured sufficiently. If the amount is more than 100 parts by weight, an excessive amount of the curing agent may remain, and the resulting cured product may have poor physical properties such as toughness.
[0071]
When the coating hardener is mixed with the hardenable resin to form a hardenable resin composition, the contact between the solid hardener and the hardenable resin is minimized by the fine particles on the surface during storage at room temperature, so that high storage stability is obtained. When curing, the solid curing agent becomes liquid by contacting with the curable resin without being suppressed by the fine particles when the temperature is applied, and the curing reaction starts immediately. Therefore, the storage stability of the curable resin composition is improved. Further, the above-mentioned coating curing agent can be produced very easily at room temperature and in a short time without using a special reaction.
[0072]
The curable resin composition of the present invention preferably further contains a silane coupling agent. The silane coupling agent mainly has a role as an adhesion assistant for satisfactorily adhering the sealant or the sealing agent to the liquid crystal display element substrate. Further, in order to improve the interaction between the inorganic or organic filler and the resin constituting the sealing agent or the sealing agent, which are blended for the purpose of improving the adhesiveness due to the stress dispersion effect, improving the linear expansion coefficient, etc. It may be used for a method of treating the surface with a silane coupling agent.
[0073]
As the silane coupling agent, a silane compound having at least one functional group represented by the following group A and at least one functional group represented by the following group B is suitably used.
[0074]
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[0075]
Specific examples of the silane compound include γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-isocyanatopropyltrimethoxysilane, and the like. These silane compounds may be used alone or in combination of two or more.
[0076]
By using a silane compound having such a structure as a silane coupling agent, the curable resin composition of the present invention can improve the adhesiveness to a substrate, and the silane compound can be formed through a functional group represented by Group B. By chemically bonding with the curable resin, it is possible to prevent outflow into the liquid crystal.
[0077]
After blending the silane compound, a heat treatment is performed. By the heat treatment, the silane compound chemically bonds to the curable resin component via the functional group represented by Group B. The heat treatment is preferably performed by stirring the resin mixture to increase the efficiency of the reaction. The method of stirring is not particularly limited, and examples thereof include a general method of rotating a stirrer or a stirring blade with a motor or the like. The temperature of the heat treatment is preferably from 30 to 70C. If the temperature is lower than 30 ° C., the reaction between the silane compound and the curable resin may not sufficiently occur. If the temperature is higher than 70 ° C., curing by heat may start. More preferably, it is 40 to 60 ° C. The heat treatment time is preferably 1 to 2 hours. If the time is less than 1 hour, there is a possibility that all the functional groups in the silane compound do not react and unreacted substances remain.
[0078]
The residual ratio of at least one functional group represented by Group B after the heat treatment is 10% or less. If it exceeds 10%, it will react with the resin component during storage to increase the viscosity, or will leak into the liquid crystal and become contaminated. Note that the residual ratio of at least one functional group represented by Group B can be determined by ¹ H-NMR measurement from the relative ratio between the peak intensity of various functional groups in the silane compound and the peak intensity after heat treatment. it can.
[0079]
It is preferable that the curable resin composition of the present invention further contains a silane coupling agent composed of an imidazole silane compound having a structure in which an imidazole skeleton and an alkoxysilyl group are bonded via a spacer group. Although the imidazole structure shows little reactivity with the curable resin at a storage temperature of about room temperature, it exhibits reactivity with the curable resin by applying a temperature. The curable resin composition has excellent adhesive strength and storage stability, and also has a low liquid crystal contamination property such as an extremely small amount of outgas generation and a low elution in the liquid crystal.
[0080]
Examples of the imidazole silane compound include those represented by the following general formula (6) or the following general formula (7).
[0081]
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[0082]
In the formula, R ^{1 to} R ⁵ each independently represent a hydrocarbon group, hydrogen, or a hydroxymethyl group. Among them, R ¹ and R ⁵ are each independently preferably a hydrocarbon group having 1 to 5 carbon atoms, hydrogen, a hydroxymethyl group, or the like, and more preferably a hydrogen or methyl group from the viewpoint of ease of synthesis. , A vinyl group and a hydroxymethyl group. R ² is preferably a hydrocarbon group having 1 to 20 carbon atoms, hydrogen, or a hydroxymethyl group, and more preferably hydrogen, a methyl group, an ethyl group, an undecyl group, or a heptadecyl group because of ease of synthesis. And a phenyl group. Further, R ³ and R ⁴ are each independently preferably an alkyl group having 1 to 3 carbon atoms, and more preferably hydrogen, a methyl group, an ethyl group or the like from the viewpoint of ease of synthesis.
[0083]
In the formula, -SP- is a spacer group comprising a linear alkyl group or a branched alkyl group to which an ester group, an ether group, a carbonate group, a urethane group, an amide group, a sulfone group, a ketone group, an alkylene group, etc. may be introduced. Represents Above all, it is preferable to introduce a urethane group from the viewpoint of reducing elution into the liquid crystal. Further, from the viewpoint of reducing elution into the liquid crystal, it is preferable that a part of the hydrogen atoms in the spacer group is substituted with a highly polar functional group. As such a substituent, for example, a halogen atom , A hydroxyl group, a mercapto group, a carboxyl group, an amino group and the like. Further, the spacer group represented by -SP- preferably has 1 to 20 atoms constituting the main chain of the spacer group. If it is less than 1, the boiling point is lowered and outgassing is liable to occur, which may easily cause liquid crystal contamination. If it is more than 20, the viscosity becomes high and it becomes difficult to handle, or the alkoxysilane equivalent becomes small, so that the amount to be added is small. Unless it is increased, the effect may be less likely to appear. More preferably, it is 3-10.
[0084]
Specific examples of the compound represented by the general formula (6) or (7) include a compound represented by the following formula (8) or the following formula (9).
[0085]
Embedded image

[0086]
Examples of the method for producing the compound represented by the above formula (8) include a method of reacting 2,4-dimethylimidazole with γ-glycidoxypropyltrimethoxysilane. Examples of the method for producing the compound represented by the above formula (9) include a method of reacting 2-phenyl-3-methyl-5-hydroxymethylimidazole with γ-isocyanatopropyltrimethoxysilane. .
[0087]
The amount of the imidazole silane compound is preferably 0.1 to 15 parts by weight based on 100 parts by weight of the curable resin. If the amount is less than 0.1 part by weight, sufficient adhesive strength may not be exhibited, and if it exceeds 15 parts by weight, the storage stability may decrease.
[0088]
The curable resin composition of the present invention further has an imidazole silane compound having a structure in which an imidazole skeleton and an alkoxysilyl group are bonded via a spacer group, an epoxy silane compound, and at least one selected from the group consisting of aminosilane compounds. It is preferable to include a filler surface-treated by one. By adding a filler, effects such as an improvement in adhesiveness due to a stress dispersion effect and an improvement in linear expansion coefficient can be obtained. Further, by treating the surface of the filler with a silane coupling agent such as an imidazole silane compound, an epoxy silane compound, or an amino silane compound having a structure in which an imidazole skeleton and an alkoxysilyl group are bonded via a spacer group, the filler is cured. The affinity with the hydrophilic resin can be increased, and these silane coupling agents do not elute into the liquid crystal and are not contaminated.
[0089]
The filler is not particularly limited and includes, for example, silica, diatomaceous earth, alumina, zinc oxide, iron oxide, magnesium oxide, tin oxide, titanium oxide, magnesium hydroxide, aluminum hydroxide, magnesium carbonate, barium sulfate, gypsum, calcium silicate And inorganic fillers such as talc, glass beads, sericite activated clay, bentonite, aluminum nitride, and silicon nitride; and organic fillers such as polyester fine particles, polyurethane fine particles, vinyl polymer fine particles, and rubber fine particles.
[0090]
The shape of the filler is not particularly limited, and may be a fixed or non-fixed product such as a sphere, a needle, or a plate.
[0091]
The treatment amount of the imidazole silane compound or the like with respect to the filler is preferably 0.05 parts by weight to 5 parts by weight with respect to 100 parts by weight of the filler. If it is less than 0.05 part by weight, the surface treatment may not be sufficient and the effect with the curable resin may be insufficient.If it exceeds 5 parts by weight, the filler is aggregated by excess imidazole silane, May be difficult to handle. More preferably, it is 0.1 to 1 part by weight.
[0092]
The method for treating the surface of the filler is not particularly limited. For example, the filler can be obtained by dissolving an imidazole silane compound or the like in water of a certain pH (acidity) and hydrolyzing the solution with a filler.
[0093]
The amount of the filler surface-treated with the imidazole silane compound is preferably 5 to 100 parts by weight based on 100 parts by weight of the curable resin. If the amount is less than 5 parts by weight, effects such as an improvement in adhesiveness and an improvement in a coefficient of linear expansion due to a sufficient stress dispersion effect may not be exhibited. If the amount exceeds 100 parts by weight, the viscosity may be significantly increased. is there. More preferably, it is 10 to 50 parts by weight.
[0094]
In order to remove ionic impurities from the curable resin composition of the present invention and satisfy the above-described performance, at least a step 1 of contacting the ion-adsorbable solid with the curable resin composition; It is preferable to manufacture by a manufacturing method having the step 2 of separating the adsorptive solid and the curable resin composition.
[0095]
The ion-adsorbing solid is not particularly limited as long as it can adsorb ionic impurities present in the adhesive. For example, a solid consisting of a compound represented by the following general formula (10) is used. preferable.
_{X m Y n (Z p O} q) W r · sH 2 O (10)
In the formula, X represents Na ⁺ , K ⁺ or Ca ²⁺ , Y represents Mg ²⁺ , Fe ²⁺ , Al ³⁺ , Fe ³⁺ , Ti ⁴⁺ or Mn ²⁺ , Z represents Si ⁴⁺ , Al ³⁺ , and W represents ^{OH -, Cl -, F -} , it represents a _CO ^{3 2-.} m, n, p, q, r, and s represent an integer of 0 or more. Further, it is preferable that m, n, p, q, r, and s satisfy the following expression (11).
2q + ra = ma + na + pa (11)
In the formula, ra, ma, na, and pa represent values obtained by multiplying r, m, n, and p by the charge of the ion of the general formula (10), respectively.
[0096]
As the above-mentioned ion-adsorbing solid, those containing an aluminum element are preferable, and those containing Al ³⁺ are more preferable. The content of Al ³⁺ is the general formula (10) of the ion atomic number of combined Y and Z in, is preferably 5 to 80 mol% is ^{Al 3+.} If it is less than 5 mol%, the amount of adsorbed ions may decrease, and if it exceeds 80 mol%, Al ³⁺ may be easily dissolved.
[0097]
It is preferable to use a layered inorganic compound as the ion-adsorbing solid. The above-mentioned layered inorganic compound has a laminated structure unit having a certain property and a gap structure, so that it has a high designability and a function-imparting property, and has a unique property and function such as two-dimensional physical properties and ion exchange. It is what you have.
[0098]
By using a layered inorganic compound, metal atoms existing between layers of the layered inorganic compound trap ionic impurities, and since the layered structure is used, ionic impurities once trapped and adsorbed are less likely to be re-eluted.
[0099]
The layered inorganic compound is preferably a layered silicate mineral.
Examples of the layered silicate mineral include hydrotalcite-based compounds, serpentine-kaolin-based compounds, talc-pyrophyllite-based compounds, smectite-based compounds, vermiculite-based compounds, mica-based, delaminated mica-based compounds, brittle mica Group compounds, chlorite group compounds, mixed layer minerals, diatomaceous earth, aluminum silicate, and the like, and preferred are hydrotalcite group compounds and serpentine-kaolin group compounds. Above all, those having an aluminum element content in the above range are more preferable, and hydrotalcite-based compounds and serpentine-kaolin group compounds in which the aluminum element content is in the above-mentioned range are more preferable. The layered silicate mineral may be a naturally occurring substance or a synthesized substance. These layered silicate minerals may be used alone or in combination of two or more.
[0100]
As the hydrotalcite compound is preferably one represented by the following general formula (12), among _{others, Mg 6 Al 2 (OH)} 16 CO 3 · 4H 2 O are preferred.
Mg _n1 Al _n2 (OH) _r1 (CO ₃ ) _r2 · sH ₂ O (12)
In the formula, n1, n2, r1, and r2 each represent an integer of 1 or more, and satisfy n = n1 + n2 and r = r1 + r2 in relation to the general formulas (10) and (11).
[0101]
Examples of the serpentine-kaolin group compounds include lizardite, birchellin, amesite, clonsteadite, nepoite, keliite, frayponite, brindoliite, kaolinite, dicite, nacrite, halothite (plate-like), ordinite And the like.
[0102]
Examples of the talc-pyrophyllite group compound include talc, willemsite, kerolite, pimelite, pyrophyllite, ferripyrophyllite and the like.
[0103]
Examples of the smectite group compounds include sapoinite, hectorite, sauconite, stevensite, swinholite, montmorillonite, beidellite, nontronite, and vorconite.
Examples of the above vermiculite group compounds include trioctahedral vermiculite and dioctahedral vermiculite.
[0104]
Examples of the mica group compound include biotite, phlogopite, iron mica, yeast knight, siderophyllite tetraferri iron mica, scale mica, polylysionite, muscovite, celadonite, iron celadonite, iron aluminoceladon Stone, alumino celadonite, Tobe mica, soda mica and the like.
[0105]
Examples of the interlayer-deficient mica compound include dioctahedral (illite, chlorite, bramarite) and trioctahedral (wonnesite).
Examples of the brittle mica group compound include clintonite, Kinoshita, bidet mica, anandite, and pearl mica.
Examples of the chlorite compound include clinochlor, chamosite, pennantite, nimite, beiliclore, donbasite, coucheite, and sodoite.
Examples of the mixed-layer mineral include collensite, hydrobiotite, arietite, kulkeite, rectorite, tosdite, dojirite, lunigianlite, and saraioite.
[0106]
The ion-adsorbing solid is preferably a granular solid so that it can be easily separated after contact with the curable resin composition. Further, the shape of the ion-adsorbing solid is not particularly limited, and the particle size thereof is preferably smaller for the purpose of increasing the chance of contact with the ionic impurities to be recovered. Therefore, the thickness is preferably 2 μm or more.
[0107]
In the above step 1, a method of bringing the ion-adsorbable solid into contact with the curable resin composition is not particularly limited, and for example, a method of mixing using a stirrer, a planetary stirrer, a primary mixer, or the like; And a method in which a curable resin composition is passed through a column filled with a curable solid. In Step 1, it is preferable that the ion-adsorbing solid and the curable resin composition are brought into contact with each other while heating at 40 to 100 ° C. When the temperature is lower than 40 ° C., the surface activity of the ion-exchangeable solid is difficult to increase, and ionic impurities may not be easily removed. If the temperature exceeds 100 ° C., the target curable resin composition may be thickened. More preferably, it is 60 to 80 ° C. When the ion-adsorbing solid and the curable resin composition are brought into contact with each other by a mixing method, the amount of the ion-adsorbing solid can be appropriately selected depending on the amount and type of the ionic impurities. The amount is preferably 2 to 20 parts by weight based on 100 parts by weight of the composition. If the amount is less than 2 parts by weight, the effect of adsorbing ionic impurities may be insufficient and the effect may not be obtained. If the amount is more than 20 parts by weight, not only the ion-adsorbing solid will be wasted but also the mixture May take a long time to be filtered due to an increase in viscosity. More preferably, it is 7 to 15 parts by weight.
[0108]
In the step 2, the method for separating the ion-adsorbing solid and the curable resin composition is not particularly limited, and examples thereof include filtration and centrifugation.
In the method for producing the curable resin composition of the present invention, it is preferable to remove the ionic impurities by mixing the ion-adsorbing solid and the curable resin composition, collecting the ion-adsorbing solid, and purifying the solid. . If the ion-adsorbing solid is not collected and left as it is, the purified ionic impurities may be eluted again in a weathering test such as high temperature and high humidity.
[0109]
The curable resin composition produced by such a production method is free of ionic impurities such as sodium ions, potassium ions, chloride ions, acrylic acid, and methacrylic acid, and these are discharged into the liquid crystal. Can be prevented.
[0110]
A display element sealing agent and a display element sealing agent using the curable resin composition of the present invention are also one of the present invention.
Since the display element sealing agent of the present invention and the sealing element for the display element of the present invention use the curable resin composition of the present invention, the storage stability is extremely high, and also before curing, regardless of after curing. The components do not leak into the liquid crystal and contaminate the liquid crystal.
[0111]
The method for producing a display element using the sealant for a display element of the present invention and the sealing agent for a display element of the present invention is not particularly limited, and for example, it can be produced by the following method.
[0112]
First, the sealing agent for a liquid crystal display element of the present invention is applied to one of two transparent substrates with electrodes (inorganic glass or plastic plate) such as an ITO thin film so as to form a predetermined pattern with a liquid crystal injection port opened. Apply. Examples of the application method include screen printing and dispenser application. The two transparent substrates are opposed to each other via a spacer, and are overlapped while performing positioning. After that, the transparent substrate is temporarily fixed by irradiating ultraviolet rays to the sealing portion, and further heated and cured in an oven at 100 to 200 ° C. for 1 hour to complete the curing. Finally, a liquid crystal is injected from the liquid crystal injection port, and the injection port is closed with the sealing agent for a liquid crystal display element of the present invention to produce a liquid crystal display cell.
[0113]
In addition, as a method of manufacturing a liquid crystal display element by a dropping method, for example, a sealant for a liquid crystal display element of the present invention is screen-printed on one of two transparent substrates with electrodes such as an ITO thin film by dispenser application or the like. Is formed. Next, a liquid crystal microdroplet is applied to the entire surface of the frame of the transparent substrate in a state where the sealing agent is not cured, and the other transparent substrate is immediately overlapped, and the sealing portion is irradiated with ultraviolet rays to perform temporary curing. After that, heating is performed during liquid crystal annealing to perform main curing, and a liquid crystal display element is manufactured.
[0114]
A display element using the sealant for a display element of the present invention and / or the sealing agent for a display element of the present invention is also one of the present invention.
[0115]
Further, the curable resin composition of the present invention can be suitably used as a sealant for attaching a sealing can in the production of an organic EL display. FIG. 3 shows a schematic diagram of the organic EL display.
Since the organic EL display is composed of a film surface using a low-molecular organic material that is weak against moisture and high energy particles, a sealing made of metal, glass, a metal vapor-deposited film or the like covers the formed film surface. You need a can. At this time, it is performed in a vacuum until the sealing can is attached, and when the sealing can is attached, the inside of the sealing can is purged with nitrogen to prevent the intrusion of the atmosphere by eliminating a difference in pressure between inside and outside, thereby preventing moisture from entering the inside. Prevent intrusion. For example, the sealing can may be bonded to a single glass substrate by forming a mask in which aluminum is vapor-deposited so as to shield the film surface of the light emitting layer from light so that only the patterned portion of the sealant transmits ultraviolet light. Good. Next, the glass substrate and the sealing can are bonded and sealed with a sealant. Therefore, it is required that the sealant does not transmit moisture.
[0116]
Next, a method of manufacturing an organic EL display will be outlined. The substrate to be used is a substrate having a film surface on which a switching element such as a TFT is formed, and an ITO film is formed on the outermost surface by sputtering. First, as pretreatment for matching the bonding surface potential and the hole layer surface potential to the substrate, ozone is generated by vacuum ultraviolet rays from a UV light source, and the transparent electrode surface of the ITO thin film formed on the glass substrate is oxidized. Next, formation of a light emitting display layer will be described with reference to FIG. CVD sputtering is performed so that the periphery of the ITO film is surrounded by the SiO ₂ film. Then, a wall surrounding the light-emitting display layer which is to be a sub-pixel is provided by the PI film on the SiO ₂ film. Next, the organic light emitting layer will be described with reference to FIG. An organic light-emitting layer is formed on this substrate. From this step to the sealing of the light-emitting layer, a series of operations are performed in a nitrogen atmosphere and a vacuum, since it is necessary to perform processing without exposing to air. First, a hole injection layer film made of an aromatic amine material is formed on the ITO film. A hole transport layer made of a diamine derivative is formed thereon by ink-jet printing and crosslinked by heating. A light-emitting layer is further formed thereon by ink-jet printing, and is heated and baked in a nitrogen atmosphere. On top of this, Alq3, which is an electron transporting luminescent material, is vapor-deposited and laminated, and further, Al-Li is formed as a cathode by vapor deposition to complete the film formation. Next, the process enters a sealing step of attaching a sealing can to the deposition substrate in order to shield the deposition layer from the atmosphere. First, a sealing agent is applied by a dispenser to a sealing can for blocking moisture and other energy. The application conditions at this time are the same as those for the production of the liquid crystal panel, and the sealing material is applied seamlessly so as to surround the periphery of the sealing can. Thereafter, in order to remove bubbles contained in the sealant, the entire sealing can is vacuum-defoamed in an atmosphere of a degree of vacuum of 0.1 Pa, and then a bonding step is started. In this step, sealing is performed while shielding the air from the atmosphere. Therefore, in a nitrogen atmosphere, a sealing can is attached so as to surround the organic light emitting layer of the film formation substrate, and an organic EL display is manufactured.
[0117]
【Example】
Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.
[0118]
(A) Synthesis of acrylic acid-modified phenol novolak epoxy resin 1000 parts by weight of liquid phenol novolak type epoxy resin (DEN 431 manufactured by Dow Chemical Company), 2 parts by weight of p-methoxyphenol as a polymerization inhibitor, reaction As a catalyst, 2 parts by weight of triethylamine and 200 parts by weight of acrylic acid were reacted at 90 ° C. for 5 hours while stirring under reflux while blowing in air. 100 parts by weight of the obtained resin was filtered through a column filled with 10 parts by weight of a natural conjugate of quartz and kaolin (Silicin V85, manufactured by Hoffman Minerals Co., Ltd.) in order to adsorb ionic impurities in the reaction product. An acid-modified phenol novolak epoxy resin (50% partially acrylated product) was obtained.
[0119]
(B) Synthesis of acrylic acid-modified propylene oxide bisphenol A epoxy resin 1440 parts by weight of liquid polyoxyalkylene bisphenol A diglycidyl ether (manufactured by Asahi Denka Kogyo KK, EP4000S), 2 parts by weight of p-methoxyphenol as a polymerization inhibitor, reaction As a catalyst, 2 parts by weight of triethylamine and 200 parts by weight of acrylic acid were reacted at 90 ° C. for 5 hours while stirring under reflux while blowing in air. 100 parts by weight of the obtained resin was filtered through a column filled with 10 parts by weight of a natural conjugate of quartz and kaolin (Silicin V85, manufactured by Hoffman Minerals Co., Ltd.) in order to adsorb ionic impurities in the reaction product. An acid-modified propylene oxide bisphenol A epoxy resin (50% partially acrylated product) was obtained.
[0120]
(C) Synthesis of urethane-modified partially acrylated product 134 parts by weight of trimethylolpropane, 0.2 parts by weight of BHT as a polymerization initiator, 0.01 parts by weight of dibutyltin dilaurate as a reaction catalyst, and 666 parts by weight of isophorone diisocyanate were added. The reaction was carried out for 2 hours while stirring under reflux. Next, 25.5 parts by weight of 2-hydroxyethyl acrylate and 111 parts by weight of glycidol were added, and the mixture was reacted at 90 ° C. for 2 hours under reflux and stirring while sending air. 100 parts by weight of the obtained resin was filtered through a column filled with 10 parts by weight of a natural conjugate of quartz and kaolin (Silicin V85, manufactured by Hoffman Minerals Co., Ltd.) to adsorb ionic impurities in the reaction product. A modified partially acrylated product was obtained.
[0121]
(Example 1)
40 parts by weight of the acrylic acid-modified phenol novolak epoxy resin obtained in (A), 20 parts by weight of the urethane-modified partially acrylated product obtained in (C), and a hydrazide-based curing agent (manufactured by Ajinomoto Fine Techno Co., Ltd.) as a latent heat curing agent , Amicure VDH) 15 parts by weight, 2,2-diethoxyacetophenone 1 part by weight as a photopolymerization initiator, silica particles (average particle size 1.5 μm) 23 parts by weight, γ-glycidoxypropyltrimethoxysilane 1 part by weight Was thoroughly mixed using a three-roll mill so as to form a uniform liquid to obtain a sealant.
[0122]
The obtained sealant was applied to one of two transparent substrates provided with transparent electrodes by a dispenser so as to draw a rectangular frame. Subsequently, a small droplet of liquid crystal (manufactured by Chisso Corporation, JC-5004LA) was applied dropwise over the entire surface of the frame of the transparent substrate, the other transparent substrate was immediately superimposed, and ultraviolet light was applied at 50 mW / cm using a high-pressure mercury lamp at the seal portion. Irradiation was performed for 60 seconds at ² . Thereafter, liquid crystal annealing was performed at 120 ° C. for 1 hour to thermally cure the liquid crystal, thereby producing a liquid crystal display cell.
[0123]
(Example 2)
Instead of 20 parts by weight of the urethane-modified partially acrylated product obtained in (C), 20 parts by weight of the propylene oxide partially acrylated product obtained in (B) was used, and a hydrazide-based curing agent (AMICURE VDH manufactured by Ajinomoto Fine-Techno Co., Ltd.) ) A sealing agent was obtained in the same manner as in Example 1 except that 15 parts by weight of a hydrazide-based curing agent (manufactured by Nippon Hydrazine Industry Co., Ltd., NDH) was used instead of 15 parts by weight, and a liquid crystal display cell was produced using the same. did.
[0124]
(Comparative Example 1)
A curable resin composition comprising 35 parts by weight of urethane acrylate (AH-600, manufactured by Kyoeisha Chemical Co., Ltd.), 15 parts by weight of 2-hydroxybutyl acrylate, 50 parts by weight of isobonyl acrylate, and 3 parts by weight of benzophenone is formed into a uniform liquid. To obtain a photocurable sealant, and a liquid crystal display cell was produced using this.
[0125]
(Comparative Example 2)
35 parts by weight of bisphenol A type epoxy resin (manufactured by Japan Epoxy Resin Co., Epicoat 8281JER), 35 parts by weight of bisphenol A type epoxy acrylic resin (manufactured by Daicel UCB, EB3700), 20 parts by weight of silica, silane coupling agent (epoxysilane, A curable resin comprising 5 parts by weight of Shin-Etsu Chemical Co., Ltd., KBM403, 2.5 parts by weight of a photopolymerization initiator (IR-651, manufactured by Ciba Specialty Co.), and 2.5 parts by weight of a cationic photopolymerization initiator represented by the following formula. The composition was sufficiently mixed using a three-roll mill so as to form a uniform liquid to obtain a sealant, and a liquid crystal display cell was produced using the sealant.
[0126]
Embedded image

[0127]
(Comparative Example 3)
A curable resin composition comprising 50 parts by weight of a bisphenol A epoxy resin (manufactured by Japan Epoxy Resin Co., Epicoat 828US) and 25 parts by weight of a hydrazide-based curing agent (manufactured by Nippon Hydrazine Industry Co., Ltd., NDH) was prepared to obtain a uniform liquid. The roll was sufficiently mixed using this roll to obtain a sealant, and a liquid crystal display cell was produced using the sealant.
[0128]
For the sealants prepared in Examples 1 and 2 and Comparative Examples 1 to 3, the specific resistance, the gel fraction, the glass transition temperature, the volume resistance, the dielectric constant at 100 kHz, and the storage stability were evaluated by the following methods. Further, the obtained liquid crystal display cells were evaluated for color unevenness by the following method.
The results are shown in Table 1.
[0129]
(Specific resistance value of sealant before curing)
Regarding the sealant before curing, in a standard temperature and humidity state (20 ° C., 65% RH), a specific resistance measuring instrument (manufactured by Toyo Technica Co., SR-6517) and an electrode for liquid (manufactured by Ando Electric Co., Ltd., model LE-21) ) Was used to measure the specific resistance value.
[0130]
(Gel fraction of sealant)
Thermal curing conditions: Heat treatment was performed at 120 ° C. for 1 hour to cure.
Light curing conditions: Light irradiation was performed at 50 mW / cm ² for 60 seconds (3000 mJ / cm ² ) to cure.
The cured sealant was immersed in acetone at room temperature for 24 hours, the dry weight before and after immersion was determined, and calculated by the following equation.
Gel fraction (%) = dry weight after immersion / dry weight before immersion × 100
[0131]
(Glass transition temperature of sealant)
The measurement was performed by the DMA method under the conditions of a heating rate of 5 ° C./min and a frequency of 10 Hz. The measurement was performed in the light shielding part.
[0132]
(Volume resistance value of cured sealant)
Apply a thin and uniform sealant on the chromium-deposited surface of the chromium-deposited glass substrate, and then cure with ultraviolet light to form an ultraviolet-cured product with a size of 85 mm x 85 mm and a thickness of 3 m. A test sample was prepared by placing a chromium-deposited glass substrate on the object side, applying a load, and heat-pressing on a hot plate at 120 ° C. for 1 hour. The area of the sealant (S (cm ² )) in this test sample and a constant voltage generator (PA36-2A regulated DC power supply, manufactured by Kenwood) between the chromium-deposited surfaces of the opposing chromium-deposited glass substrates. And a voltage (A (A)) flowing through the film was measured with an ammeter (R644C digital multimeter manufactured by Advantest). When the film pressure (T (cm)) of the sealing agent was used, the volume resistivity (Ω · cm) was determined by the following equation.
Volume resistivity (Ω · cm) = (VS) / (AT)
However, the applied voltage was 500 V DC, and the conduction time was 1 minute.
[0133]
(Dielectric constant of cured sealant at 100 kHz)
A sealant was thinly and uniformly applied on a glass plate and then cured to prepare a test piece having a size of 60 mm × 60 mm and a thickness of 3 m. It was measured at a frequency of 100 kHz by an electrode non-contact method (gap method) using an electrode for dielectric measurement (HP16451B, manufactured by Yokogawa HP) and an LCR meter (4284A, manufactured by Hewlett Packard) by a method according to ASTM D150. .
[0134]
(Storage stability evaluation)
After storage of the sealant before curing at room temperature for one week, the evaluation was performed by using an E-type viscometer, where the viscosity was within 2 times the initial viscosity, as 場合, and when the viscosity was 2 times or more, as x.
[0135]
(Color unevenness evaluation)
About the obtained liquid crystal display cell, before and after standing at 60 ° C. and 95% RH for 500 hours, color unevenness generated in the liquid crystal around the seal portion was visually observed. ◎ (no color unevenness), ○ (color unevenness) The liquid crystal contamination was evaluated in four stages: (slightly), Δ (slight color unevenness), and X (slight color unevenness). In this case, the number of samples per section was five.
[0136]
[Table 1]

[0137]
【The invention's effect】
According to the present invention, when used as a sealant for a liquid crystal display element or a sealing agent for a liquid crystal display element in the production of a liquid crystal display element, the components do not dissolve into the liquid crystal material and do not cause liquid crystal contamination. A curable resin composition which is suitable for the production of a display element particularly by a liquid crystal dropping method, because it has little color unevenness in display and excellent storage stability, a sealant for a display element using the same, and a closure for a display element Agent can be provided.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating formation of a light emitting display layer in a method for manufacturing an organic EL display.
FIG. 2 is a schematic diagram illustrating formation of an organic light emitting layer in a method for manufacturing an organic EL display.
FIG. 3 is a schematic diagram showing a structure of an organic EL display.

Claims (9)

A curable resin composition used for a sealant or a sealing agent for a liquid crystal dropping method,
A curable resin composition, wherein the gel fraction after the thermosetting reaction is 70% or more, and the gel fraction after the photocuring reaction is 70% or more. The curable resin composition according to claim 1, wherein the glass transition temperature is 50C or higher. The curable resin composition according to claim 1, wherein a volume resistance value after curing is 1 × 10 ¹³ Ω · cm or more. The curable resin composition according to claim 1, 2 or 3, wherein a specific resistance value before curing is 1.0 × 10 ^{6 to} 1.0 × 10 ¹⁰ Ω · cm. Contains curable resin and curing agent,
The curable resin weight / the curing agent weight is 3 to 10,
The curable resin composition according to claim 1, wherein the curing agent is a primary amine or a secondary amine. 6. The curable resin composition according to claim 1, wherein the compound having a hydroxyl group and / or a urethane bond is contained in the curable resin in an amount of 50% by weight or more. A sealant for a display element, comprising the curable resin composition according to claim 1, 2, 3, 4, 5, or 6. A sealing element for a display element, comprising the curable resin composition according to claim 1. A display element comprising the sealant for a display element according to claim 7 and / or the sealing agent for a display element according to claim 8.

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