JP4099220B2 - Adhesive sheets - Google Patents

Description

（式中、Ｒは炭素数２〜２０の直鎖状または分枝状の炭化水素基である）
で表される繰り返し単位を有するポリマ―が好ましい。
【００１８】
このポリマ―には、ポリカ―ボネ―トジオ―ル（またはその誘導体）とジカルボン酸（またはその誘導体）とから合成されるポリエステル、ポリカ―ボネ―トジカルボン酸とジオ―ルとから合成されるポリエステル、ポリカ―ボネ―トジオ―ルとジイソシアネ―トとから合成されるポリウレタンなどがあり、その中でも、とくにポリカ―ボネ―トジオ―ルとジカルボン酸とから合成されるポリエステルが好ましい。この種のポリエステルは、ポリカ―ボネ―トジオ―ルを必須としたジオ―ル成分と炭素数が２〜２０の脂肪族または脂環族の炭化水素基を分子骨格とするジカルボン酸を必須としたジカルボン酸成分とから合成される、重量平均分子量が１万以上、好ましくは３万以上、とくに好ましくは５万以上（通常、３０万まで）のものである。
【００１９】
ここで用いられるポリカ―ボネ―トジオ―ルは、つぎの式；

（式中、Ｒは炭素数２〜２０の直鎖状または分枝状の炭化水素基である）
で表わされる繰り返し単位を有するジオ―ルで、数平均分子量としては、４００以上、好ましくは９００以上（通常１万まで）であるのがよい。このようなポリカ―ボネ―トジオ―ルとしては、ポリヘキサメチレンカ―ボネ―トジオ―ル、ポリ（３−メチルペンテンカ―ボネ―ト）ジオ―ル、ポリプロピレンカ―ボネ―トジオ―ルなど、それらの混合物またはそれらの共重合物などがある。市販品としては、ダイセル化学工業（株）製の「ＰＬＡＣＣＥＬ ＣＤ２０５ＰＬ」、「同ＣＤ２０８ＰＬ」、「同ＣＤ２１０ＰＬ」、「同ＣＤ２２０ＰＬ」、「同ＣＤ２０５ＨＬ」、「同ＣＤ２０８ＨＬ」、「同ＣＤ２１０ＨＬ」、「同ＣＤ２２０ＨＬ」などが挙げられる。
【００２０】
ジオ―ル成分としては、上記のポリカ―ボネ―トジオ―ルのほか、必要により、エチレングリコ―ル、プロピレングリコ―ル、ブタンジオ―ル、ヘキサンジオ―ル、オクタンジオ―ル、デカンジオ―ル、オクタデカンジオ―ルなどの直鎖状のジオ―ルや分枝状のジオ―ルなどの成分を併用してもよい。これらの他のジオ―ルは、ジオ―ル成分全体の５０重量％以下、好ましくは３０重量％以下の使用量とするのがよい。また、ポリマ―を高分子量化するために、３官能以上のポリオ―ル成分を少量添加してもよい。
【００２１】
また、ジカルボン酸成分は、炭素数が２〜２０の脂肪族または脂環族の炭化水素基を分子骨格としたもので、上記の炭化水素基が直鎖状のものでも分枝状のものであつてもよい。具体的には、コハク酸、メチルコハク酸、アジピン酸、ピメリツク酸、アゼライン酸、セバシン酸、１，１２−ドデカン二酸、１，１４−テトラデカン二酸、テトラヒドロフタル酸、エンドメチレンテトラヒドロフタル酸、これらの酸無水物や低級アルキルエステルなどが挙げられる。
【００２２】
ジカルボン酸成分としては、上記の炭素数が２〜２０の脂肪族または脂環族の炭化水素基を分子骨格としたジカルボン酸をこれ単独で用いるのが望ましいが、場合により、このジカルボン酸とともに、芳香族の炭化水素基を分子骨格としたジカルボン酸を、適宜混合して使用してもよい。これら芳香族の炭化水素基を分子骨格としたジカルボン酸の使用量としては、ジカルボン酸成分全体の５０重量％以下、とくに好ましくは３０重量％以下の少量であるのがよい。また、合成されるポリエステルを高分子量化するなどの目的で、３官能またはそれ以上の多価カルボン酸成分を少量添加することもできる。
【００２３】
ポリエステルは、上記のジオ―ル成分とジカルボン酸成分とを、常法にしたがい、無触媒または適宜の触媒などを用いて、エステル化反応させることにより、得られる。その際、ジオ―ル成分とジカルボン酸成分とは、等モル反応が望ましいが、エステル化反応を促進するため、どちらかを過剰に用いて反応させてもよい。このようにして得られるポリエステルは、前記分子量を有していることが望ましい。これは、分子量があまり低いと、高度に架橋した粘着剤は架橋密度が高くなり、非常に硬い性質を有したり、逆に架橋密度を低く設定しようとすると、未架橋成分の分子量が低いため、耐熱性などの面で好ましくないためである。
【００２４】
本発明では、通常、このようなポリエステルをはじめとするポリカ―ボネ―ト構造を持つポリマ―を適宜の手段で架橋処理して、室温での貯蔵弾性率〔Ｇ´〕および接着力が前記範囲となる粘着剤組成物とする。架橋手段は任意でよいが、架橋剤としてポリイソシアネ―ト化合物、エポキシ化合物、アジリジン化合物、金属キレ―ト化合物、金属アルコキシド化合物などの多官能性化合物を用い、これと上記ポリマ―（中に含まれる水酸基やカルボキシル基）とを反応させて架橋する方法が一般的である。多官能性化合物としては、とくにポリイソシアネ―ト化合物が好ましい。
【００２５】
ポリイソシアネ―ト化合物としては、エチレンジイソシアネ―ト、ブチレンジイソシアネ―ト、ヘキサメチレンジイソシアネ―トなどの低級脂肪族ポリイソシアネ―ト類、シクロペンチレンジイソシアネ―ト、シクロヘキシレンジイソシアネ―ト、イソホロンジイソシアネ―トなどの脂環族ポリイソシアネ―ト類、２，４−トリレンジイソシアネ―ト、４，４´−ジフエニルメタンジイソシアネ―ト、キシリレンジイソシアネ―トなどの芳香族ポリイソシアネ―ト類などがある。そのほか、トリメチロ―ルプロパンのトリレンジイソシアネ―ト付加物〔日本ポリウレタン（株）製の「コロネ―トＬ」〕、トリメチロ―ルプロパンのヘキサメチレンジイソシアネ―ト付加物〔日本ポリウレタン（株）製の「コロネ―トＨＬ」〕なども用いられる。
【００２６】
これらの多官能性化合物は、単独でまたは２種以上の混合系で用いられる。使用量は、架橋するポリマーとのバランスにより、また粘着剤組成物の使用目的によつて適宜選択される。一般には、ポリカーボネート構造を持つポリマー１００重量部あたり、０．５重量部以上、好ましくは１〜５重量部程度配合して、架橋処理するのがよい。これにより、上記ポリマーの溶剤不溶分が１０〜６５重量％、好ましくは１５〜６５重量％、より好ましくは２０〜６５重量％となる粘着剤組成物が得られる。ポリマーの溶剤不溶分が小さすぎると、粘着剤の凝集力が不足して、十分な弾性率や耐熱性，耐久性が得られない。
【００２７】
他の架橋手段として、ポリマ―に架橋剤として多官能モノマ―を配合し、これを電子線などで架橋させる方法がある。多官能モノマ―には、エチレングリコ―ルジ（メタ）アクリレ―ト、ペンタエリスリト―ルトリ（メタ）アクリレ―ト、テトラメチロ―ルメタンテトラ（メタ）アクリレ―ト、トリメチロ―ルプロパントリ（メタ）アクリレ―トなどがある。これらの多官能モノマ―の使用量は、電子線などで架橋したのちのポリマ―の溶剤不溶分が前記同様の値となるように、前記のポリマ―１００重量部あたり、多官能モノマ―が１〜５重量部、好ましくは２〜４重量部となるようにするのがよい。
【００２８】
本発明の粘着剤組成物は、ベ―スポリマ―として上記のポリカ―ボネ―ト構造を持つポリマ―を使用し、これを通常上記のような手段で架橋構造化したものであるが、この組成物には、従来公知の各種の粘着付与剤を配合してもよく、また無機または有機の充てん剤、金属粉、顔料などの粉体、粒子状物、箔状物、老化防止剤、可塑剤などの各種の添加剤を任意に含ませることができる。
【００３１】
また、本発明においては、ポリカ―ボネ―ト構造を持つポリマ―とともに、ガラス転移温度が−１０℃以下のアクリル系重合体を、上記ポリマ―との合計量中１０〜９０重量％、好ましくは１５〜８５重量％の割合で用いることにより、前記の特性に加えて、様々な被着体に対し良好な接着性を示すとともに、クリ―プ特性や長期の耐久性にすぐれた粘着剤組成物を得ることができる。
【００３２】
従来、粘着付与剤を含まないアクリル系感圧接着剤は、プラスチツクへの接着性に乏しく、一方、粘着付与剤を含んだアクリル系ないし天然ゴム系感圧接着剤は、プラスチツクへの接着性は比較的良いが、クリ―プ特性や長期の耐久性に劣る問題があつた。ところが、上記本発明の粘着剤組成物では、このような問題が回避されて、様々な被着体、とくにポリカ―ボネ―トやアクリル樹脂などのプラスチツクに対する接着性にすぐれ、しかもクリ―プ特性や長期の耐久性にすぐれた粘着剤を提供することが可能となる。
【００３３】
ここで使用するアクリル系重合体は、炭素数が４〜１４のアルキル基を有する（メタ）アクリレ―トを５０〜１００重量％含有する単量体の重合体であつて、ガラス転移温度が−１０℃以下、とくに−１５℃以下（通常−９０℃程度まで）となるものが好ましく用いられる。ガラス転移温度が−１０℃より高くなると、初期接着力に劣り、好ましくない。炭素数が４〜１４のアルキル基を有する（メタ）アクリレ―トとしては、たとえば、ブチル基、イソブチル基、イソアミル基、ヘキシル基、ヘプチル基、２−エチルヘキシル基、イソオクチル基、イソノニル基、ラウリル基、イソミリスチル基などのアルキル基を有する（メタ）アクリル酸のアルキルエステルが挙げられる。
【００３４】
このようなアクリル系重合体を併用する場合、通常、このアクリル系重合体と前記のポリカ―ボネ―ト構造を持つポリマ―とを別々に合成したのち、両者を溶液状または塊状で混合することにより、粘着剤組成物が調製される。しかし、場合により、一方の重合体中で他方を重合させるという方法で調製してもよいし、両者を同時に重合するといつた方法で調製してもよい。
【００３５】
これらの調製方法において、上記アクリル系重合体の使用量は、ポリカーボネート構造を持つポリマーとの合計量中に占める割合が前記範囲内となるようにする。上記アクリル系重合体が１０重量％未満では、初期接着性が低くなり、９０重量％を超えると、プラスチツクに対する接着性が低くなる。また、上記アクリル系重合体とポリカーボネート構造を持つポリマーとは、その一方または両方が前記方法にて架橋処理されるが、ポリマー全体の溶剤不溶分が１０〜６５重量％、好ましくは１５〜６５重量％、さらに好ましくは２０〜６５重量％の範囲となるようにするのがよい。溶剤不溶分が低いと、クリープ特性や長期の耐久性に劣り、また高すぎると、初期接着性に劣り、いずれも好ましくない。
【００３６】
さらに、本発明においては、ポリカ―ボネ―ト構造を持つポリマ―とともに、軟化点８０℃以上の樹脂を、上記ポリマ―との合計量中１０〜５０重量％、好ましくは１３〜４５重量％、より好ましくは１５〜３５重量％の割合で用いることにより、前記の特性に加えて、高温域での耐クリ―プ性と接着性を満足し、かつ低温での耐衝撃性にもすぐれた粘着剤組成物を得ることができる。
【００３７】
従来、特公昭５６−１３０４０号公報に記載のように、粘着剤組成物に熱溶融性樹脂を添加したものは知られている。これは、１００℃以上の加熱処理を必要とする熱硬化タイプのものに比べ、処理作業が簡便で、被着体に耐熱性を必要としないなどの利点があるが、反面、高温域での耐クリ―プ性と接着性を両立しがたいという問題がある。また、特公平２−５０１４６号公報には、ガラス転移温度の高い重合体を側鎖に有するアクリル系のグラフトポリマ―に熱溶融性樹脂を添加したものが知られている。これは、高温域での耐クリ―プ性と接着性を満足するが、低温での耐衝撃性に劣る問題がある。ところが、上記本発明の粘着剤組成物にはこのような問題がなく、高温域での耐クリ―プ性と接着性を満足し、かつ低温での耐衝撃性にもすぐれる熱時粘着剤組成物を提供できる。
【００３８】
ここで使用する樹脂は、軟化点が８０℃以上、好ましくは９０℃以上、さらに好ましくは１００℃以上で、通常１５０℃以下のものである。軟化点が８０℃より低くなると、耐クリープ性、高温での接着力が低下するため、好ましくない。樹脂の種類としては、テルペン系、ロジン系、アルキルフェノール系、テルペンフェノール系、ロジンフェノール系、クマロン−インデン系、芳香族石油系、脂肪族石油系などが挙げられる。この種の樹脂は、ポリカーボネート構造を持つポリマーとの合計量中に占める割合が１０重量％未満では、剪断接着力が低下し、５０重量％を超えると、低温での耐衝撃性に劣る。また、この樹脂を含む架橋処理後の溶剤不溶分は１０〜６５重量％、好ましくは１５〜６５重量％、より好ましくは２０〜６５重量％の範囲にあるのがよい。溶剤不溶分が低すぎると耐久性に劣り、高すぎると接着性に劣り、いずれも好ましくない。
【００３９】
本発明の粘着シ―ト類は、上記種々の構成の粘着剤組成物をシ―ト状やテ―プ状の形態としたもの、つまり、上記構成の粘着剤組成物からなる層を少なくとも有するものであつて、これには、まず、剥離ライナ―上に上記の粘着剤組成物からなる層を乾燥後の厚さが通常１０〜１５０μｍ程度となるように塗着して、その上に必要によりさらに上記の剥離ライナ―を貼り合わせてなる、いわゆる基材レスの両面粘着シ―ト類が含まれる。この場合、粘着特性の改良のために、他の粘着剤組成物を利用して多層構造化してもよい。
【００４０】
また、より一般的な粘着シ―ト類として、ポリエステルフイルムなどのプラスチツクフイルムや、紙、不織布などの多孔質材料、金属箔などからなる基材を用い、これら基材の片面または両面に上記の粘着剤組成物からなる層を乾燥後の厚さが通常片面で１０〜１５０μｍ程度となるように塗着して、粘着剤層を基材に担持させ、その粘着面に剥離ライナ―を貼り合わせてなる、基材付きの片面または両面粘着シ―ト類とすることができる。この場合、粘着特性の改良のために、他の粘着剤組成物を利用して多層構造化してもよい。なお、このような基材付きの粘着シ―ト類および前記の基材レスの両面粘着シ―ト類において、ポリカ―ボネ―ト構造を持つポリマ―などの架橋処理は、上記した粘着シ―ト類の製造工程中またはその工程後に適宜施すことができる。
【００４１】
本発明では、このような粘着シ―ト類において、粘着面に貼り合わせる剥離ライナ―としてポリエチレンフイルムやポリプロピレンフイルムなどからなるシリコ―ン処理を施していない剥離ライナ―を使用することが可能である。つまり、このような剥離ライナ―を使用したときでも、このライナ―の剥離力が２００ｇ／５０mm幅以下、好ましくは１００ｇ／５０mm幅以下、さらに好ましくは５０ｇ／５０mm幅以下（通常１ｇ／５０mm幅まで）となる非常に良好な剥離性が得られ、しかも前記した良好な接着力を維持させることができる。
【００４２】
アクリル系やゴム系粘着剤では、ポリエチレンフイルムやポリプロピレンフイルムなどを剥離ライナ―とすると、剥離力が５００ｇ／５０mm幅以上となつて、剥離作業性の低下をきたすため、シリコ―ン処理剥離ライナ―の使用が不可避であつた。本発明では、シリコ―ン処理を施していない剥離ライナ―を用いて、その剥離力を２００ｇ／５０mm幅以下に設定できるので、上記ライナ―の除去が容易であり、通常使用されるシリコ―ン処理剥離ライナ―の粘着テ―プ製品と同様の取り扱いが可能である。このため、シリコ―ン処理剥離ライナ―から上記剥離ライナ―への変更に伴う装置、作業手順などの変更も不要である。
【００４３】
このように、本発明の粘着シ―ト類においては、剥離ライナ―にポリエチレンフイルムやポリプロピレンフイルムなどを用いることにより、シリコ―ンを全く含まない粘着シ―ト類の製造が可能であり、その結果、シリコ―ンの含有が問題となりやすいコンピユ―タ機器などに適した粘着シ―ト類を提供できる。また、剥離ライナ―がポリエチレン、ポリプロピレンといつた単純なフイルム材料である場合には、近年、とくに問題となつているプラスチツクのリサイクル性にすぐれるという効果も得ることができる。
【００４４】
本発明に用いられるシリコ―ン処理を施していない剥離ライナ―としては、ポリエチレン、ポリプロピレン、エチレン−プロピレン共重合体（ブロツクまたはランダム共重合体）またはこれらの混合物からなるポリオレフイン系フイルム、あるいは表面が上記同様のポリオレフイン、つまりポリエチレン、ポリプロピレン、エチレン−プロピレン共重合体（ブロツクまたはランダム共重合体）またはこれらの混合物にて加工されたフイルムが挙げられる。後者の表面が加工されたフイルムとしては、たとえば、紙類や他のフイルムと上記ポリオレフイン系フイルムとの積層物などが含まれる。
【００４５】
一方、本発明では、このような剥離ライナ―を用いない粘着シ―ト類として、基材の片面に前記構成の粘着剤組成物からなる層を前記同様の厚さに設け、この基材の少なくとも背面側をポリエチレン、ポリプロピレン、エチレン−プロピレン共重合体（ブロツクまたはランダム共重合体）またはこれらの混合物からなるポリオレフインで構成した粘着シ―ト類を得ることもできる。
【００４６】
この種の粘着シ―ト類は、基材背面側をシリコ―ン処理していないことを特徴としたものであるが、粘着剤組成物からなる層と基材背面との剥離性が良好で、剥離ライナ―を介装することなくロ―ル状に巻回することが可能である。このように、剥離ライナ―を持たず、また基材背面をシリコ―ン化合物で剥離処理する必要がないことから、シリコ―ン化合物を実質的に含まない粘着シ―ト類として、コンピユ―タ機器などに有利に使用できる。なお、粘着剤組成物からなる層と基材との投錨性が確保できる限り、基材の背面側だけでなく、基材全体が上記同様のポリオレフインで構成されていてもよい。
【００４７】
【実施例】
つぎに、本発明の実施例を記載して、より具体的に説明する。以下、部とあるのは重量基準である。また、重合体の重量平均分子量は、ゲルパ―ミエ―シヨンクロマトグラフイ―によるポリスチレン換算の値である。
【００４８】
実施例１−１
攪拌機、温度計および水分離管を付した四つ口のセパラブルフラスコに、ポリカ―ボネ―トジオ―ル〔ダイセル化学工業（株）製のＰＬＡＣＣＥＬ ＣＤ２１０ＰＬ、水酸基価１１５ＫＯＨmg／ｇ〕２５０ｇ（水酸基：０．５１２当量）、セバシン酸５１．８ｇ（酸基：０．５１２当量）、触媒としてのジブチルチンオキサイド（以下、ＤＢＴＯという）１２７mgを仕込み、反応水排出溶剤としての少量のトルエンの存在下、攪拌を開始しながら１８０℃まで昇温し、この温度で保持した。しばらくすると、水の流出分離が認められ、反応が進行し始めた。約２４時間反応を続けて、重量平均分子量が５５，０００となるポリエステルを得た。
【００４９】
このポリエステルをトルエンで固形分濃度４０重量％に希釈したのち、ポリエステル１００部（固形分）あたり、架橋剤としてトリメチロ―ルプロパンのヘキサメチレンジイソシアネ―ト付加物〔日本ポリウレタン（株）製のコロネ―トＨＬ〕２部（固形分）を添加し、粘着剤組成物とした。これを、アプリケ―タにより、厚さが３８μｍのポリエチレンテレフタレ―トフイルム（以下、ＰＥＴフイルムという）の上に塗布し、１３０℃で５分間乾燥して、厚さが５０μｍの粘着剤層を形成し、さらにアフタ―キユア―として５０℃の雰囲気中で５日間のエ―ジングを行い、粘着テ―プを作製した。また、上記と同様にして、貯蔵弾性率測定用として、離型紙上に厚さが５０μｍの粘着剤層を形成した。
【００５０】
実施例１−２
攪拌機、温度計および水分離管を付した四つ口のセパラブルフラスコに、ポリカ―ボネ―トジオ―ル〔ダイセル化学工業（株）製のＰＬＡＣＣＥＬ ＣＤ２２０ＰＬ、水酸基価５６．１ＫＯＨmg／ｇ〕２５０ｇ（水酸基：０．２５当量）、アゼライン酸２３．５ｇ（酸基：０．２５当量）、触媒としてのＤＢＴＯを６２mg仕込み、反応水排出溶剤としての少量のトルエンの存在下、攪拌を開始しながら１８０℃まで昇温し、この温度で保持した。しばらくすると、水の流出分離が認められ、反応が進行し始めた。約２５時間反応を続けて、重量平均分子量が７８，０００となるポリエステルを得た。
【００５１】
このポリエステルをトルエンで固形分濃度４０重量％に希釈したのち、ポリエステル１００部（固形分）あたり、架橋剤としてトリメチロ―ルプロパンのトリレンジイソシアネ―ト付加物〔日本ポリウレタン（株）製のコロネ―トＬ〕１．５部（固形分）を添加し、粘着剤組成物とした。この粘着剤組成物を、アプリケ―タにより、厚さが３８μｍのＰＥＴフイルムの上に塗布し、１３０℃で５分間乾燥して、厚さが５０μｍの粘着剤層を形成し、さらにアフタ―キユア―として５０℃の雰囲気中で５日間のエ―ジングを行い、粘着テ―プを作製した。また、上記と同様にして、貯蔵弾性率測定用として、離型紙上に厚さが５０μｍの粘着剤層を形成した。
【００５２】
実施例１−３
架橋剤として、コロネ―トＬに代えて、トリメチロ―ルプロパンのヘキサメチレンジイソシアネ―ト付加物〔日本ポリウレタン（株）製のコロネ―トＨＬ〕２．５部（固形分）を添加するようにした以外は、実施例１−２と同様にして、粘着テ―プを作製した。また、上記と同様にして、貯蔵弾性率測定用として、離型紙上に厚さが５０μｍの粘着剤層を形成した。
【００５３】
実施例１−４
攪拌機、温度計および水分離管を付した四つ口のセパラブルフラスコに、ポリカ―ボネ―トジオ―ル〔ダイセル化学工業（株）製のＰＬＡＣＣＥＬ ＣＤ２２０ＰＬ、水酸基価５６．１ＫＯＨmg／ｇ〕２５０ｇ（水酸基：０．２５当量）、セバシン酸１２．６ｇとアゼライン酸１１．８ｇ（酸基合計：０．２５当量）、触媒としてのＤＢＴＯを６２mg仕込み、反応水排出溶剤としての少量のトルエンの存在下、攪拌を開始しながら１８０℃まで昇温し、この温度で保持した。しばらくすると、水の流出分離が認められ、反応が進行し始めた。約２５時間反応を続けて、重量平均分子量が７５，０００となるポリエステルを得た。
【００５４】
このポリエステルをトルエンで固形分濃度４０重量％に希釈したのち、ポリエステル１００部（固形分）あたり、架橋剤としてトリメチロ―ルプロパンのヘキサメチレンジイソシアネ―ト付加物〔日本ポリウレタン（株）製のコロネ―トＨＬ〕２部（固形分）を添加し、粘着剤組成物とした。この粘着剤組成物を、アプリケ―タにより、厚さが３８μｍのＰＥＴフイルムの上に塗布し、１３０℃で５分間乾燥して、厚さが５０μｍの粘着剤層を形成し、さらにアフタ―キユア―として５０℃の雰囲気中で５日間のエ―ジングを行い、粘着テ―プを作製した。また、上記と同様にして、貯蔵弾性率測定用として、離型紙上に厚さが５０μｍの粘着剤層を形成した。
【００５５】
比較例１−１
攪拌機および温度計を付した反応容器に、アクリル酸ｎ−ブチル９５部、アクリル酸５部、トルエン１５０部、アゾビスイソブチロニトリル０．１部を入れ、窒素ガス雰囲気中、６０℃で約７時間溶液重合して、ポリマ―溶液を得た。このポリマ―１００部（固形分）あたり、架橋剤としてトリメチロ―ルプロパンのトリレンジイソシアネ―ト付加物〔日本ポリウレタン（株）製のコロネ―トＬ〕２部（固形分）を添加し、粘着剤組成物とした。この粘着剤組成物を、アプリケ―タにより、厚さが３８μｍのＰＥＴフイルムの上に塗布し、１３０℃で５分間乾燥して、厚さが５０μｍの粘着剤層を形成し、さらにアフタ―キユア―として５０℃の雰囲気中で５日間のエ―ジングを行い、粘着テ―プを作製した。また、上記と同様にして、貯蔵弾性率測定用として、離型紙上に厚さが５０μｍの粘着剤層を形成した。
【００５６】
比較例１−２
攪拌機および温度計を付した反応容器に、アクリル酸２−エチルヘキシル８０部、アクリル酸２０部、光重合開始剤としてイルガキユア―１８４（チバガイギ―社製）０．６部を入れ、十分に窒素ガス置換したのち、高圧水銀ランプにより、約１００ｍｊ／cm² の照射量で紫外線を照射した。この照射により得られた粘稠物に対し、内部架橋剤としてトリメチロ―ルプロパントリアクリレ―ト１部を配合して、粘着剤組成物とした。この粘着剤組成物を、アプリケ―タにより、厚さが３８μｍのＰＥＴフイルムの上に、厚さが５０μｍとなるように塗布した。その後、酸素による重合阻害をなくすため、ＰＥＴ剥離ライナ―でカバ―し、高圧水銀ランプにより、約１，４００ｍｊ／cm² の照射量で紫外線を照射して、粘着剤層を形成し、粘着テ―プを作製した。また、上記と同様にして、貯蔵弾性率測定用として、離型紙上に厚さが５０μｍの粘着剤層を形成した。
【００５７】
上記の実施例１−（１〜４）および比較例１−（１，２）の各粘着テ―プについて、−３０℃、室温（２３℃）および８０℃における各貯蔵弾性率と、室温（２３℃）における接着力（１８０°剥離粘着力）を、以下の方法により調べた。これらの測定結果は、表１に示されるとおりであつた。
【００５８】
＜貯蔵弾性率＞
貯蔵弾性率〔Ｇ´〕は、粘着剤組成物の剪断貯蔵弾性率を指し、外部から加えられたエネルギ―をひずみエネルギ―として貯蔵する弾性成分というべきものであるが、この貯蔵弾性率〔Ｇ´〕の測定は、レオメトリツク社製の動的粘弾性測定装置ＲＤＳ−IIを使用し、サンプル厚さ約１．５mm、直径７．９mmのパラレルプレ―トの治具により、周波数１Ｈｚで測定するという方式で行つた。
【００５９】
＜接着力＞
粘着テ―プを、被着体としてのアクリル板（ポリメチルメタクリレ―ト）に貼り付けて、雰囲気温度２３℃、貼付時間３０分、剥離速度３００mm／分の条件で１８０°剥離接着力を測定した。
【００６０】
表１

【００６１】
つぎに、上記の実施例１−（１〜４）および比較例１−（１，２）の各粘着テ―プについて、以下の要領にて、室温（２３℃）での拇指タツクと、耐熱性（８０℃）を測定した。これらの結果は、下記の表２に示されるとおりであつた。
【００６２】
＜拇指タツクの測定＞
室温（２３℃）において、粘着テ―プ表面に親指を触れ、短時間（１秒程度）の押し付け後、引き離し、その時の親指面に感じる抵抗で評価した。
【００６３】
＜耐熱性の測定＞
粘着テ―プを、被着体としてのベ―クライト板に貼り付け、雰囲気温度８０℃で、垂直方向に５００ｇ／２cm² の荷重を与え、落下するまでの保持時間（分）の測定を行つた。
【００６４】
表２

【００６５】
上記の表１および表２の結果から、本発明の実施例１−（１〜４）の各粘着テ―プは、比較例１−（１〜２）の粘着テ―プに比べて、高弾性でタツクフリ―でありながら接着力が大きく、耐熱性の面でも満足できることがわかる。
【００６６】
実施例２−１
攪拌機、温度計、水分離管を付した四つ口セパラブルフラスコに、ポリカ―ボネ―トジオ―ル〔ダイセル化学工業（株）製のＰＬＡＣＣＥＬ ＣＤ２１０ＰＬ、水酸基価１１５．０ＫＯＨmg／ｇ〕２００ｇ（水酸基：０．４１当量）、無水コハク酸２０．５１ｇ（酸基：０．４１当量）、触媒としてのＤＢＴＯを１０２mg仕込み、反応水排出溶剤としての少量のトルエンの存在下、攪拌を開始しながら１８０℃まで昇温し、この温度で保持した。しばらくすると水の流出分離が認められ、反応が進行し始めた。約２７時間反応を続けて、重量平均分子量５６，０００のポリエステルを得た。
【００６７】
このポリエステルをトルエンで固形分濃度５０重量％に希釈したのち、ポリエステル１００部（固形分）あたり、架橋剤としてトリメチロ―ルプロパンのヘキサメチレンジイソシアネ―ト付加物〔日本ポリウレタン（株）製のコロネ―トＨＬ〕１．５部（固形分）を添加し、粘着剤組成物を調製した。これを、アプリケ―タにより厚さが３８μｍのＰＥＴフイルムの上に塗布し、１３０℃で５分間乾燥して、厚さが５０μｍの粘着剤層を形成し、さらにアフタ―キユア―として５０℃の雰囲気中で５日間のエ―ジングを行い、粘着テ―プを作製した。
【００６８】
実施例２−２
攪拌機、温度計、水分離管を付した四つ口セパラブルフラスコに、ポリカ―ボネ―トジオ―ル〔ダイセル化学工業（株）製のＰＬＡＣＣＥＬ ＣＤ２１０ＰＬ、水酸基価１１５．０ＫＯＨmg／ｇ〕２５０ｇ（水酸基：０．５１２当量）、アジピン酸３７．４４ｇ（酸基：０．５１２当量）、触媒としてのＤＢＴＯを１２７mg仕込み、反応水排出溶剤としての少量のトルエンの存在下、攪拌を開始しながら１８０℃まで昇温し、この温度で保持した。しばらくすると水の流出分離が認められ、反応が進行し始めた。約３０時間反応を続けて、重量平均分子量５８，０００のポリエステルを得た。
【００６９】
このポリエステルをトルエンで固形分濃度５０重量％に希釈したのち、ポリエステル１００部（固形分）あたり、架橋剤としてトリメチロ―ルプロパンのトリレンジイソシアネ―ト付加物〔日本ポリウレタン（株）製のコロネ―トＬ〕１．５部（固形分）を添加し、粘着剤組成物を調製した。これを、アプリケ―タにより厚さが３８μｍのＰＥＴフイルムの上に塗布し、１３０℃で５分間乾燥して、厚さが５０μｍの粘着剤層を形成し、さらにアフタ―キユア―として５０℃の雰囲気中で５日間のエ―ジングを行い、粘着テ―プを作製した。
【００７０】
実施例２−３
攪拌機、温度計、水分離管を付した四つ口セパラブルフラスコに、ポリカ―ボネ―トジオ―ル〔ダイセル化学工業（株）製のＰＬＡＣＣＥＬ ＣＤ２２０ＰＬ、水酸基価５６．１ＫＯＨmg／ｇ〕２５０ｇ（水酸基：０．２５当量）、セバシン酸２５．２８ｇ（酸基：０．２５当量）、触媒としてのＤＢＴＯを６２mg仕込み、反応水排出溶剤としての少量のトルエンの存在下、攪拌を開始しながら１８０℃まで昇温し、この温度で保持した。しばらくすると水の流出分離が認められ、反応が進行し始めた。約２５時間反応を続けて、重量平均分子量７２，０００のポリエステルを得た。
【００７１】
このポリエステルをトルエンで固形分濃度５０重量％に希釈したのち、ポリエステル１００部（固形分）あたり、架橋剤としてトリメチロ―ルプロパンのヘキサメチレンジイソシアネ―ト付加物〔日本ポリウレタン（株）製のコロネ―トＨＬ〕２部（固形分）を添加し、粘着剤組成物を調製した。これを、アプリケ―タにより厚さが３８μｍのＰＥＴフイルムの上に塗布し、１３０℃で５分間乾燥して、厚さが５０μｍの粘着剤層を形成し、さらにアフタ―キユア―として５０℃の雰囲気中で５日間のエ―ジングを行い、粘着テ―プを作製した。
【００７２】
実施例２−４
実施例２−３で得たポリエステルをトルエンで固形分濃度５０重量％に希釈したのち、ポリエステル１００部（固形分）あたり、架橋剤としてトリメチロ―ルプロパントリアクリレ―ト３部（固形分）を添加し、粘着剤組成物を調製した。これを、アプリケ―タにより厚さが３８μｍのＰＥＴフイルムの上に塗布し、１００℃で５分間乾燥して、厚さが５０μｍの粘着剤層を形成し、さらに電子線を６Ｍｒａｄ照射して、粘着テ―プを作製した。
【００７３】
上記の実施例２−（１〜４）の各粘着テ―プについて、ポリエステルの溶剤不溶分、接着力および耐熱性の測定を行つた。これらの測定結果は、後記の表３に示されるとおりであつた。なお、溶剤不溶分および接着力は下記の方法により、耐熱性は前記の方法により測定した。
【００７４】
＜溶剤不溶分の測定＞
粘着テ―プより約０．１ｇの粘着剤をサンプリングし、精秤した。これを、約５０ｍｌのトルエン中に室温で５日間浸漬したのち、溶剤不溶分を取り出して、１３０℃中で約１時間乾燥したのち、秤量した。溶剤不溶分〔Ｘ〕（重量％）を、以下の式により算出した。

【００７５】
＜接着力の測定＞
粘着テ―プを、被着体としてのポリカ―ボネ―ト板、アクリル板（ポリメチルメタクリレ―ト）に貼り付け、雰囲気温度２３℃、貼り付け時間３０分、剥離速度３００mm／分の条件で、１８０°剥離接着力を測定した。
【００７６】
表３

【００７７】
上記の表３の結果から明らかなように、本発明の実施例２−（１〜４）の粘着剤組成物を用いた各粘着テ―プは、いずれも、良好な接着力を有しているとともに、さらに耐熱性の面でも格段にすぐれていることがわかる。
【００９４】
実施例４−１
冷却管、窒素導入管、温度計、撹拌装置を備えた反応容器に、酢酸エチル５０部およびトルエン５０部を溶媒として、アクリル酸２−エチルヘキシル８０部、アクリル酸ｎ−ブチル１２部、アクリル酸８部、アクリル酸２−ヒドロキシエチル０．１部、２，２´−アゾビスイソブチロニトリル０．１部を入れ、窒素気流中で重合し、ガラス転移温度が−４３℃で、重量平均分子量が６０万であるアクリル系重合体Ａの溶液を得た。
【００９５】
これとは別に、温度計、撹拌装置、水分離管を備えた反応容器に、ポリカ―ボネ―トジオ―ルとして、ダイセル化学工業（株）製のＰＬＡＣＣＥＬ ＣＤ２２０ＰＬ（水酸基価５６．１ＫＯＨmg／ｇ）１００部、セバシン酸１０．１部と、触媒としてのＤＢＴＯを０．０２５部入れ、反応水排出溶剤としてのトルエンの存在下、撹拌しながら１８０℃に昇温した。しばらくすると、水の流出分離が認められた。約２４時間反応を行うことにより、重量平均分子量が６万であるポリエステル系重合体Ｂの溶液を得た。
【００９６】
上記のアクリル系重合体Ａの溶液と上記のポリエステル系重合体Ｂの溶液を、アクリル系重合体Ａ８０部あたりポリエステル系重合体Ｂ２０部となるように、混合し、これにさらにトリメチロ―ルプロパンのトリレンジイソシアネ―ト付加物２部を添加，混合して、粘着剤組成物の溶液を調製した。つぎに、この粘着剤組成物の溶液を、厚さが３８μｍのポリエステルフイルムの片面に、乾燥後の厚さが５０μｍとなるように塗布し、１２０℃で２分間乾燥して、粘着テ―プを作製した。また、剥離処理を施したポリエステルフイルムの片面に、上記と同様に塗布して、溶剤不溶分測定用のサンプルを作製した。
【００９７】
実施例４−２
実施例４−１で得たアクリル系重合体Ａの溶液とポリエステル系重合体Ｂの溶液とを、アクリル系重合体Ａ５０部あたりポリエステル系重合体Ｂ５０部となるように混合し、これにさらにトリメチロ―ルプロパンのトリレンジイソシアネ―ト付加物２部を添加，混合して、粘着剤組成物の溶液を調製した。この溶液を用いて、以下実施例４−１と同様にして、粘着テ―プを作製した。また、実施例４−１と同様にして、溶剤不溶分測定用のサンプルを作製した。
【００９８】
実施例４−３
実施例４−１で得たアクリル系重合体Ａの溶液とポリエステル系重合体Ｂの溶液とを、アクリル系重合体Ａ２０部あたりポリエステル系重合体Ｂ８０部となるように混合し、これにさらにトリメチロ―ルプロパンのトリレンジイソシアネ―ト付加物２部を添加，混合して、粘着剤組成物の溶液を調製した。この溶液を用いて、以下実施例４−１と同様にして、粘着テ―プを作製した。また、実施例４−１と同様にして、溶剤不溶分測定用のサンプルを作製した。
【００９９】
実施例４−４
実施例４−１で得たポリエステル系重合体Ｂの溶液をセパレ―タ上に塗布し、８０℃で１時間乾燥して、ポリエステル系重合体Ｂの固形分を得た。この固形分４０部を、アクリル酸２−エチルヘキシル４８部、アクリロイルモルホリン１２部およびアクリル酸２−ヒドロキシエチル０．０６部からなる単量体混合物（この混合物の共重合体のガラス転移温度は−４０℃）に溶解し、これにさらに２，２−ジメトキシ−２−フエニルアセトフエノン０．１部、トリメチロ―ルプロパンのトリレンジイソシアネ―ト付加物２部を添加，混合した。
【０１００】
この混合液を、厚さが３８μｍのポリエステルフイルムの片面に、紫外線照射後の厚さが５０μｍとなるように塗布したのち、紫外線を照射して、上記の単量体混合物を重合し、硬化させることにより、粘着テ―プを作製した。また、剥離処理を施したポリエステルフイルムの片面に上記と同様に塗布し、紫外線を照射して、溶剤不溶分測定用のサンプルを作製した。
【０１０１】
参考例４−１
実施例４−１で得たポリエステル系重合体Ｂの溶液に、ポリエステル系重合体Ｂ１００部あたりトリメチロ―ルプロパンのトリレンジイソシアネ―ト付加物２部を添加，混合して、粘着剤組成物の溶液を調製した。この溶液を用いて、以下実施例４−１と同様にして、粘着テ―プを作製した。また、実施例４−１と同様にして、溶剤不溶分測定用のサンプルを作製した。
【０１０２】
比較例４−１
実施例４−１で得たアクリル系重合体Ａの溶液に、アクリル系重合体Ａ１００部あたりトリメチロ―ルプロパンのトリレンジイソシアネ―ト付加物２部を添加，混合して、粘着剤組成物の溶液を調製した。この溶液を用いて、以下実施例４−１と同様にして、粘着テ―プを作製した。また、実施例４−１と同様にして、溶剤不溶分測定用のサンプルを作製した。
【０１０３】
比較例４−２
実施例４−１で得たアクリル系重合体Ａの溶液に、アクリル系重合体Ａ８０部あたり、ポリカ―ボネ―トジオ―ル〔ダイセル化学工業（株）製のＰＬＡＣＣＥＬ ＣＤ２２０ＰＬ、水酸基価５６．１ＫＯＨmg／ｇ〕２０部およびトリメチロ―ルプロパンのトリレンジイソシアネ―ト付加物２部を添加，混合して、粘着剤組成物の溶液を調製した。この粘着剤組成物の溶液を用いて、以下実施例４−１と同様にして、粘着テ―プを作製した。また、実施例４−１と同様にして、溶剤不溶分測定用のサンプルを作製した。
【０１０４】
上記の実施例４−（１〜４）、参考例４−１および比較例４−（１，２）で作製した各粘着テ―プについて、接着力および保持力を、下記の方法で測定した。この測定結果を、前記の方法で測定した粘着剤組成物の溶剤不溶分とともに、下記の表５に示した。なお、同表中、溶剤不溶分の欄における「Ｘ₁ 」は溶剤としてトルエンを使用し、また「Ｘ₂ 」は溶剤として酢酸エチルを使用したときの測定結果であり、酢酸エチルの場合、この溶剤中に室温で３日間浸漬したのち、１００℃で２時間乾燥して秤量し、算出したものである。
【０１０５】
＜接着力＞
２０mm×１００mmの粘着テ―プを、被着体に２Kgのロ―ラを１往復させる方法で圧着し、２３℃で２０分および７０℃で４８時間放置後、２３℃，６５％ＲＨの雰囲気下、引張速度３００mm／分で、１８０度剥離接着力を測定した。なお、被着体としては、ポリカ―ボネ―ト板、ポリアクリル板、ステンレス板（ＳＵＳ４３０ＢＡ）を使用した。表５中、「Ａ」はポリカ―ボネ―ト板、「Ｂ」はアクリル樹脂板、「Ｃ」はステンレス板である。
【０１０６】
＜保持力＞
幅１０mmの粘着テ―プを、フエノ―ル樹脂板に対し１０mm×２０mmの接着面積で貼り付け、２０分経過後８０℃に２０分放置したのち、フエノ―ル樹脂板を垂下し、接着テ―プの自由端に５００ｇの均一荷重を負荷して、８０℃での粘着テ―プの落下時間（分）と、１２０分後のずれ距離（mm）を測定した。
【０１０７】
表５

【０１０８】
上記の表５より、実施例４−（１〜４）の接着テ―プは、様々な被着体、とくにポリカ―ボネ―ト、アクリル樹脂などのプラスチツクに対し大きな接着力を有し、また保持力が大きく耐久性にすぐれていることが明らかである。
【０１０９】
実施例５−１
温度計、撹拌機および水分離管を備えた反応容器に、ポリカ―ボネ―トジオ―ルとして、ダイセル化学工業（株）製のＰＬＡＣＣＥＬ ＣＤ２２０ＰＬ（水酸基価５６．１ＫＯＨmg／ｇ）１００部、セバシン酸１０．１部、ジブチル錫オキシド０．０２５部を入れ、反応水排出溶剤としてのトルエンの存在下、撹拌しながら１８０℃に昇温した。しばらくすると、水の流出分離が認められた。約２４時間反応を続けることにより、重量平均分子量が６万であるポリエステル系重合体の溶液を得た。
【０１１０】
このポリエステル系重合体の溶液に、その固形分１００部あたり、軟化点が１１５℃のテルペンフエノ―ル樹脂３０部と、トリメチロ―ルプロパンのヘキサメチレンジイソシアネ―ト付加物２部を添加，混合して、熱時粘着剤組成物の溶液を調製した。つぎに、この熱時粘着剤組成物の溶液を、厚さが３８μｍのポリエステルフイルムの片面に、乾燥後の厚さが５０μｍとなるように塗布し、１２０℃で２分間乾燥して、保持力測定用の粘着テ―プを作製した。また、剥離処理を施したポリエステルフイルムの片面に、上記と同様に塗布して、剪断接着力および耐衝撃性測定用の粘着テ―プを作製した。
【０１１１】
実施例５−２
軟化点が１１５℃のテルペンフエノ―ル樹脂３０部に代えて、軟化点が１４５℃のロジンフエノ―ル樹脂２０部を用いた以外は、実施例５−１と同様にして、熱時粘着剤組成物の溶液を調製し、またこの溶液を用いて保持力測定用と剪断接着力および耐衝撃性測定用の粘着テ―プを作製した。
【０１１２】
実施例５−３
軟化点が１１５℃のテルペンフエノ―ル樹脂３０部に代えて、軟化点が１２０℃のクマロン−インデン樹脂５０部を用いた以外は、実施例５−１と同様にして、熱時粘着剤組成物の溶液を調製し、またこの溶液を用いて保持力測定用と剪断接着力および耐衝撃性測定用の粘着テ―プを作製した。
【０１１３】
参考例５−１
実施例５−１で得たポリエステル系重合体の溶液に、その固形分１００部あたり、トリメチロ―ルプロパンのトリレンジイソシアネ―ト付加物２部を添加，混合して、熱時粘着剤組成物の溶液を調製した。つぎに、この熱時粘着剤組成物の溶液を用いて、実施例５−１と同様にして、保持力測定用と剪断接着力および耐衝撃性測定用の粘着テ―プを作製した。
【０１１４】
参考例５−２
軟化点が１１５℃のテルペンフエノ―ル樹脂３０部に代えて、軟化点が５０℃のテルペンフエノ―ル樹脂３０部を用いた以外は、実施例５−１と同様にして、熱時粘着剤組成物の溶液を調製し、またこの溶液を用いて保持力測定用と剪断接着力および耐衝撃性測定用の粘着テ―プを作製した。
【０１１５】
比較例５−１
冷却管、窒素導入管、温度計および撹拌機を備えた反応容器に、酢酸エチル５０部およびトルエン５０部を溶媒として、アクリル酸２−エチルヘキシル５０部、アクリル酸ｎ−ブチル４５部、アクリル酸４．９部、アクリル酸２−ヒドロキシエチル０．１部、２，２´−アゾビスイソブチロニトリル０．１部を入れ、窒素ガス気流中で重合処理することにより、重量平均分子量が７０万であるアクリル系重合体の溶液を得た。
【０１１６】
このアクリル系重合体の溶液に、その固形分１００部あたり、軟化点が１１５℃のテルペンフエノ―ル樹脂３０部と、トリメチロ―ルプロパンのヘキサメチレンジイソシアネ―ト付加物２部を添加，混合して、熱時粘着剤組成物の溶液を調製した。つぎに、この溶液を用いて、実施例５−１と同様にして、保持力測定用と剪断接着力および耐衝撃性測定用の粘着テ―プを作製した。
【０１１７】
上記の実施例５−（１〜３）、参考例５−（１，２）および比較例５−１で作製した各粘着テ―プについて、保持力と剪断接着力および耐衝撃性を、下記の方法で測定した。これらの結果は、後記の表６に示されるとおりであつた。
【０１１８】
＜保持力＞
幅１０mmの粘着テ―プを、フエノ―ル樹脂板に対し１０mm×２０mmの接着面積で１２０℃，５Kg／cm² ，１分の条件で貼り付け、２０分経過後８０℃に２０分放置したのち、フエノ―ル樹脂板を垂下し、粘着テ―プの自由端に５００ｇの均一荷重を負荷して、８０℃での粘着テ―プの落下時間（分）を測定した。
【０１１９】
＜剪断接着力＞
１０mm×１０mmの粘着テ―プを、０．５mm×２０mm×１００mmのアルミニウム板と２．０mm×２０mm×１００mmのＰＣ板との間に貼り合わせ、１２０℃，５Kg／cm² ，２分の条件で接着し、２時間放置後、その剪断に要する力を、引張速度１０mm／分の条件で、常温（２３℃，６５％ＲＨ）および高温（８０℃）の雰囲気下で、それぞれ測定した。
【０１２０】
＜耐衝撃性＞
１０mm×１０mmの接着テ―プを、２mm×６０mm×６０mmのＰＣ板と０．５mm×５０mm×５０mmのＳＵＳ３０４板との間に貼り合わせ、１２０℃，５Kg／cm² ，１分の条件で接着し、２時間放置後、０℃で８０cmの高さからコンクリ―ト上に落下させ、破壊に要するまでの回数を測定した。
【０１２１】
表６

【０１２２】
上記の表６より、実施例５−（１〜３）の各粘着テ―プは、高温（８０℃）での保持力（耐クリ―プ性）と常温および高温での剪断接着力を満足し、かつ低温（０℃）での耐衝撃性にもすぐれていることが明らかである。
【０１２３】
実施例６−１
四つ口セパラブルフラスコに攪拌機、温度計および水分離管を付し、ポリカ―ボネ―トジオ―ル〔ダイセル化学工業（株）製の「ＰＬＡＣＣＥＬ ＣＤ２１０ＰＬ」、水酸基価：１１５．０ＫＯＨmg／ｇ〕２００．０ｇ（水酸基：０．４１当量）、無水コハク酸２０．５１ｇ（酸基：０．４１当量）、触媒としてのＤＢＴＯを１０２mg仕込み、反応水排出溶剤としての少量のトルエンの存在下、攪拌を開始しながら１８０℃まで昇温し、この温度で保持した。しばらくすると水の流出分離が認められ、反応が進行し始めた。約２７時間反応を続け、重量平均分子量が５６，０００となるポリエステルを得た。
【０１２４】
このポリエステルをトルエンで固形分濃度５０重量％に希釈した。このポリエステル１００部（固形分）に対し、架橋剤としてトリメチロ―ルプロパンのヘキサメチレンジイソシアネ―ト付加物〔日本ポリウレタン（株）製の「コロネ―トＨＬ」〕を１．０部（固形分）添加し、粘着剤組成物とした。この粘着剤組成物を、アプリケ―タ―により、厚さが３８μｍのＰＥＴフイルムの上に塗布し、１３０℃で３分間乾燥して、厚さが５０μｍの粘着剤層を形成した。さらに、この粘着面に厚さが６０μｍのポリエチレンフイルムを貼り合わせて、粘着シ―トを作製した。
【０１２５】
実施例６−２
四つ口セパラブルフラスコに攪拌機、温度計および水分離管を付し、ポリカ―ボネ―トジオ―ル〔ダイセル化学（株）製の「ＰＬＡＣＣＥＬ ＣＤ２１０ＰＬ」、水酸基価：１１５．０ＫＯＨmg／ｇ〕２５０．０ｇ（水酸基：０．５１当量）、セバシン酸５１．８ｇ（酸基：０．５１当量）、触媒としてのＤＢＴＯを１２７mg仕込み、反応水排出溶剤としての少量のトルエンの存在下、攪拌を開始しながら１８０℃まで昇温し、この温度で保持した。しばらくすると水の流出分離が認められ、反応が進行し始めた。約３０時間反応を続けて、重量平均分子量が６０，０００となるポリエステルを得た。
【０１２６】
このポリエステルをトルエンで固形分濃度５０重量％に希釈した。このポリエステル１００部（固形分）に対して、架橋剤として、トリメチロ―ルプロパンのトリレンジイソシアネ―ト付加物〔日本ポリウレタン（株）製の「コロネ―トＬ」〕を１．５部（固形分）添加し、粘着剤組成物とした。この粘着剤組成物を、アプリケ―タ―により、厚さが３８μｍのＰＥＴフイルム上に塗布し、１３０℃で５分間乾燥して、厚さが５０μｍの粘着剤層を形成した。さらに、この粘着面に厚さが４０μｍのポリプロピレンフイルムを貼り合わせて、粘着シ―トを作製した。
【０１２７】
実施例６−３
四つ口セパラブルフラスコに攪拌機、温度計および水分離管を付し、ポリカ―ボネ―トジオ―ル〔ダイセル化学工業（株）製の「ＰＬＡＣＣＥＬ ＣＤ２２０ＰＬ」、水酸基価：５６．１ＫＯＨmg／ｇ〕２５０．０ｇ（水酸基：０．２５当量）、セバシン酸２６．８ｇ（酸基：０．２６当量）、触媒としてのＤＢＴＯを６２mg仕込み、反応水排出溶剤としての少量のトルエンの存在下、攪拌を開始しながら１８０℃まで昇温し、この温度で保持した。しばらくすると水の流出分離が認められ、反応が進行し始めた。約３１時間反応を続けて、重量平均分子量が７４，０００となるポリエステルを得た。
【０１２８】
このポリエステルをトルエンで固形分濃度５０重量％に希釈した。このポリエステル１００部（固形分）に対し、架橋剤としてトリメチロ―ルプロパンのヘキサメチレンジイソシアネ―ト付加物〔日本ポリウレタン（株）製の「コロネ―トＨＬ」〕を１．５部（固形分）添加し、粘着剤組成物とした。この粘着剤組成物を、アプリケ―タ―により、厚さが３８μｍのＰＥＴフイルム上に塗布し、１３０℃で５分間乾燥して、厚さが５０μｍの粘着剤層を形成した。さらに、この粘着面に厚さが４０μｍのポリエチレンとポリプロピレンとのブレンドフイルムを貼り合わせて、粘着シ―トを作製した。
【０１２９】
実施例６−４
実施例６−３のポリエステルをトルエンで固形分濃度５０重量％に希釈した。このポリエステル１００部（固形分）に対し、架橋剤としてトリメチロ―ルプロパンのヘキサメチレンジイソシアネ―ト付加物〔日本ポリウレタン（株）製の「コロネ―トＨＬ」〕を２．０部（固形分）添加し、粘着剤組成物とした。この粘着剤組成物を、アプリケ―タ―により、厚さが６０μｍのポリエチレンフイルム上に塗布し、８０℃で１０分間乾燥して、厚さが５０μｍの粘着剤層を形成した。さらに、この粘着面に厚さが６０μｍのポリエチレンフイルムを貼り合わせて、基材レスの両面粘着タイプの粘着シ―トを作製した。
【０１３０】
実施例６−５
四つ口セパラブルフラスコに攪拌機、温度計および水分離管を付し、ポリカ―ボネ―トジオ―ル〔ダイセル化学工業（株）製の「ＰＬＡＣＣＥＬ ＣＤ２２０ＰＬ」、水酸基価：５６．１ＫＯＨmg／ｇ〕２５０．０ｇ（水酸基：０．２５当量）、セバシン酸２５．０ｇ（酸基：０．２５当量）、触媒としてのチタニウムテトライソプロポキシドを７０mg仕込み、反応水排出溶剤としての少量のトルエンの存在下、攪拌を開始しながら１８０℃まで昇温し、この温度で保持した。しばらくすると水の流出分離が認められ、反応が進行し始めた。約２４時間反応を続けて、重量平均分子量が５９，０００となるポリエステルを得た。
【０１３１】
このポリエステルをトルエンで固形分濃度５０重量％に希釈した。このポリエステル１００部（固形分）に対し、架橋剤としてトリメチロ―ルプロパンのヘキサメチレンジイソシアネ―ト付加物〔日本ポリウレタン（株）製の「コロネ―トＨＬ」〕を１．５部（固形分）添加し、粘着剤組成物とした。この粘着剤組成物を、アプリケ―タ―により、厚さが３８μｍのＰＥＴフイルム上に塗布し、１３０℃で５分間乾燥して、厚さが５０μｍの粘着剤層を形成した。さらに、この粘着面に厚さが６０μｍのポリエチレンフイルムを貼り合わせて、粘着シ―トを作製した。
【０１３２】
実施例６−６
四つ口セパラブルフラスコに攪拌機、温度計および水分離管を付し、ポリカ―ボネ―トジオ―ル〔ダイセル化学工業（株）製の「ＰＬＡＣＣＥＬ ＣＤ２２０ＰＬ」、水酸基価：５６．１ＫＯＨmg／ｇ〕１５５．４ｇとポリカプロラクトンジオ―ル〔ダイセル化学工業（株）製の「ＰＬＡＣＣＥＬ ２２０ＰＬ」、水酸基価：５５．９ＫＯＨmg／ｇ〕８４．１ｇ（水酸基合計：０．２４当量）、無水コハク酸１２．１ｇ（酸基：０．２４当量）、触媒としてのＤＢＴＯを５９mg仕込み、反応水排出溶剤としての少量のトルエンの存在下、攪拌を開始しながら１８０℃まで昇温し、この温度で保持した。しばらくすると水の流出分離が認められ、反応が進行し始めた。約２０時間反応を続けて、重量平均分子量が３７，０００となるポリエステルを得た。
【０１３３】
このポリエステルをトルエンで固形分濃度５０重量％に希釈した。このポリエステル１００部（固形分）に対し、架橋剤としてトリメチロ―ルプロパンのヘキサメチレンジイソシアネ―ト付加物〔日本ポリウレタン（株）製の「コロネ―トＨＬ」〕を３．０部（固形分）添加し、粘着剤組成物とした。この粘着剤組成物を、アプリケ―タ―により、厚さが３８μｍのＰＥＴフイルム上に塗布し、１３０℃で５分間乾燥して、厚さが５０μｍの粘着剤層を形成した。さらに、この粘着面に厚さが６０μｍのポリエチレンフイルムを貼り合わせて、粘着シ―トを作製した。
【０１３４】
実施例６−７
四つ口セパラブルフラスコに攪拌機、温度計および水分離管を付し、ポリカ―ボネ―トジオ―ル〔ダイセル化学工業（株）製の「ＰＬＡＣＣＥＬ ＣＤ２２０ＰＬ」、水酸基価：５６．１ＫＯＨmg／ｇ〕２１８．１ｇとオクタンジオ―ル２４．２ｇ（水酸基合計：０．５５当量）、無水コハク酸２７．９ｇ（酸基：０．５６当量）、触媒としてのＤＢＴＯを６０mg仕込み、反応水排出溶剤としての少量のトルエンの存在下、攪拌を開始しながら１８０℃まで昇温し、この温度で保持した。しばらくすると水の流出分離が認められ、反応が進行し始めた。約２２時間反応を続けて、重量平均分子量が２４，０００のポリエステルを得た。
【０１３５】
このポリエステルをトルエンで固形分濃度５０重量％に希釈した。このポリエステル１００部（固形分）に対し、架橋剤としてトリメチロ―ルプロパンのヘキサメチレンジイソシアネ―ト付加物〔日本ポリウレタン（株）製の「コロネ―トＨＬ」〕を３．０部（固形分）添加し、粘着剤組成物とした。この粘着剤組成物を、アプリケ―タ―により、厚さが３８μｍのＰＥＴフイルム上に塗布し、１３０℃で５分間乾燥して、厚さが５０μｍの粘着剤層を形成した。さらに、この粘着面に厚さが６０μｍのポリエチレンフイルムを貼り合わせて、粘着シ―トを作製した。
【０１３６】
比較例６−１
アクリル酸ブチル９２部とアクリル酸８部とのモノマ―混合物を使用し、このモノマ―混合物にトルエン１５０部とアゾビスイソブチロニトリル０．１部とを添加した混合溶液を、窒素雰囲気中、６０℃で約７時間溶液重合して、ポリマ―溶液を得た。このポリマ―１００部（固形分）に対し、架橋剤としてトリメチロ―ルプロパンのトリレンジイソシアネ―ト付加物〔日本ポリウレタン（株）製の「コロネ―トＬ」〕を２．０部（固形分）添加し、粘着剤組成物とした。この粘着剤組成物を、アプリケ―タ―により、厚さが３８μｍのＰＥＴフイルム上に塗布し、１２０℃で５分間乾燥して、厚さが５０μｍの粘着剤層を形成した。さらに、この粘着面に厚さが４０μｍのポリエチレンとポリプロピレンとのブレンドフイルムを貼り合わせて、粘着シ―トを作製した。
【０１３７】
比較例６−２
天然ゴム１００部、脂肪族系石油樹脂（軟化点１００℃）１００部、軟化剤（ポリブテン）２０部をトルエン１５０部に溶解し、架橋剤としてトリメチロ―ルプロパンのトリレンジイソシアネ―ト付加物〔日本ポリウレタン（株）製の「コロネ―トＬ」〕を１．５部（固形分）添加し、粘着剤組成物とした。この粘着剤組成物を、アプリケ―タ―により、厚さが３８μｍのＰＥＴフイルム上に塗布し、１００℃で５分間乾燥して、厚さが５０μｍの粘着剤層を形成した。さらに、この粘着面に厚さが６０μｍのポリエチレンフイルムを貼り合わせて、粘着シ―トを作製した。
【０１３８】
上記の実施例６−（１〜７）および比較例６−（１，２）の各粘着シ―トについて、下記の方法により、剥離ライナ―の剥離力および接着力の測定を行つた。結果は、後記の表７に示されるとおりであつた。
【０１３９】
＜剥離力の測定＞
雰囲気温度２３℃にて、粘着シ―トから剥離ライナ―をインストロン型引張試験機により剥離速度３００mm／分の条件で剥離し、剥離角度１８０度で剥離力を測定した。
【０１４０】
＜接着力の測定＞
粘着シ―トから剥離ライナ―を剥がし、アルミニウム板に貼り付け、雰囲気温度２３℃、貼付時間３０分、剥離速度３００mm／分の条件で、１８０度剥離粘着力を測定した。なお、実施例６−４については基材を持つていないため、厚さが３８μｍのＰＥＴフイルムを裏打ちして測定した。
【０１４１】
表７

【０１４２】
上記の表７の結果から明らかなように、本発明の実施例６−（１〜７）の各粘着シ―トは、いずれも、シリコ―ン処理を施していない剥離ライナ―を用いているにもかかわらず、剥離作業に支障をきたすことのない小さい剥離力を示すとともに、実用上望まれる大きな接着力を有していることがわかる。
【０１４３】
【発明の効果】
以上のように、本発明では、高弾性でタツクフリ―でありながら、接着力が大きい、接着作業性と接着性との両立を図れる、また耐熱性にすぐれて、物品の保持性、固定性などにもすぐれる粘着剤組成物とその粘着シ―ト類を提供できる。とくに、ベ―スポリマ―としてポリカ―ボネ―ト構造を有するポリマ―を用い、これを架橋剤などにて架橋処理することにより、耐熱性や耐久性などの特性に格段にすぐれた上記粘着剤組成物とその粘着シ―ト類を提供でき、新規構成の粘着剤製品として各種分野でのより一層の展開を図ることができる。
【０１４４】
また、本発明では、ポリカーボネート構造を持つポリマーとともに、ガラス転移温度が−１０℃以下のアクリル系重合体を併用することにより、様々な被着体に対して非常に良好な接着特性を示すとともに、クリープ特性や長期の耐久性にすぐれた粘着剤組成物とその粘着シート類を提供できる。また同様に、上記ポリマーとともに、軟化点８０℃以上の樹脂を併用することにより、高温域での耐クリープ性と接着性を満足し、かつ低温での耐衝撃性にもすぐれた粘着剤組成物とその粘着シート類を提供できる。
【０１４５】
さらに、本発明では、ポリカ―ボネ―ト構造を持つポリマ―を用いた上記各構成の粘着剤組成物からなる層に対して、ポリエチレンフイルムやポリプロピレンフイルムなどからなるシリコ―ン処理を施していない剥離ライナ―を用いることにより、シリコ―ンを含有せずに良好な剥離性を有し、かつ大きな接着力を示す粘着シ―ト類を提供することができ、このものは、電子関連機器での用途、とくにシリコ―ンの含有が問題となりやすいコンピユ―タ機器などの用途に適した粘着シ―ト類として非常に有利に使用することができる。
【０１４６】
また、本発明では、基材の片面に、ポリカ―ボネ―ト構造を持つポリマ―を用いた上記各構成の粘着剤組成物からなる層を設けるとともに、この基材の少なくとも背面側をポリエチレンやポリプロピレンなどのポリオレフインで構成させることにより、剥離ライナ―を介装することなくロ―ル状に巻回することが可能な粘着シ―ト類を提供することができ、このものは、剥離ライナ―を持たない、また基材背面側をシリコ―ン化合物で剥離処理する必要のない、シリコ―ン化合物を実質的に含まない粘着シ―ト類として、電子関連機器での用途、とくにシリコ―ンの含有が問題となりやすいコンピユ―タ機器などの用途に適した粘着シ―ト類として有利に使用することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a non-adhesive or low-adhesive (tack-free) pressure-sensitive adhesive composition at room temperature and an adhesive sheet in the form of a sheet or tape.
[0002]
[Prior art]
Usually, the adhesive is D.I. As described in Satas, Adhesive Age, 31 (9), 28 (1988), the storage elastic modulus [G ′] at room temperature is 1 × 10⁶ dyne / cm² Degree or less. When the storage elastic modulus at room temperature becomes high, the pressure-sensitive adhesive becomes too hard and does not adhere. This is because microscopic contact between the pressure-sensitive adhesive and the adherend is sufficiently performed in the adhesion process so that it does not show adhesiveness even when visually (optically) closely adhered, such as a food wrap film. This is because there is not.
[0003]
[Problems to be solved by the invention]
However, conventional adhesives are sticky and sticky and have softness, so they adhere quickly, but they do not easily peel off even if they are lightly touched at locations other than the intended purpose, making position correction difficult. Hot. Further, in processing such as cutting and punching of adhesive sheets, there is a problem that the processing blade is contaminated with the adhesive.
[0004]
In order to solve these problems, if the storage elastic modulus of the pressure-sensitive adhesive is increased, as described above, the adhesiveness is also reduced together with the tack, and adhesion to the adherend is not required unless adhesion auxiliary means such as heat treatment is taken. Is difficult. Thus, conventionally, a highly elastic, non-tacky or low-tacky (tack-free) pressure-sensitive adhesive that can prevent deterioration in bonding workability and the like, and has excellent adhesiveness has not been found.
[0005]
  In view of such circumstances, an object of the present invention is to exhibit excellent adhesiveness while being highly elastic and tack-free near room temperature. Therefore, a pressure-sensitive adhesive composition that can achieve both adhesive workability and adhesiveness. It is in providing a thing and its adhesive sheet. Another object is to provide the above-mentioned pressure-sensitive adhesive composition and pressure-sensitive adhesive sheets excellent in durability and heat resistance.Inis there.
[0006]
Another object of the present invention is to provide the above-mentioned pressure-sensitive adhesive composition and its pressure-sensitive adhesive sheets that exhibit good adhesion to various adherends and have excellent creep characteristics and long-term durability. Another object of the present invention is to provide the above-mentioned pressure-sensitive adhesive composition and its pressure-sensitive adhesive sheet which satisfy creep resistance and adhesiveness in a high temperature range and are excellent in impact resistance at low temperature. Furthermore, another object of the present invention is to use the above-mentioned adhesive sheet suitable for computer equipment, etc., which uses a release liner that has not been subjected to a silicon treatment, and the inclusion of silicon is likely to be a problem. It is an object of the present invention to provide the above-mentioned pressure-sensitive adhesive sheets having excellent liner peelability and good adhesion. In addition, the present invention can be wound in a roll without using a release liner, and can be used as an adhesive sheet that does not substantially contain a silicone compound, such as a computer device. One objective is to provide adhesive sheets suitable for the application.
[0007]
[Means for Solving the Problems]
  When the present inventors select a polymer for constituting a pressure-sensitive adhesive and cross-link this polymer, a pressure-sensitive adhesive composition having specific values of storage elastic modulus and adhesive strength at room temperature is obtained. High elasticity and tack-free performance while exhibiting good adhesion, and by specifying the solvent-insoluble content of the polymer, durability such as heat resistance and weather resistanceExcellentIt has been found that an adhesive composition can be obtained.
[0008]
  The present invention has been completed on the basis of such knowledge, and in the pressure-sensitive adhesive sheets in which the pressure-sensitive adhesive composition is in the form of a sheet or tape,
The following formula:

                        -(O-R-O-C) n-
                                        ‖
                                        O

    (In the formula, R is a linear or branched hydrocarbon group having 2 to 20 carbon atoms)

As a polymer having a polycarbonate structure having a repeating unit represented by formula (1), a pressure-sensitive adhesive composition containing a polyester having a weight average molecular weight of 10,000 or more has a cross-linked layer, and the solvent-insoluble content of the polymer in this layer is20-65% by weightThe present invention relates to a pressure-sensitive adhesive sheet characterized by Among them, the polyester having a weight average molecular weight of 10,000 or more is required to have a diol component essentially including polycarbonate diol and a dicarboxylic acid having a molecular skeleton of an aliphatic or alicyclic hydrocarbon group having 2 to 20 carbon atoms. The pressure-sensitive adhesive sheet is composed of a polyester having a weight average molecular weight of 10,000 or more and synthesized from the dicarboxylic acid component..
[0009]
  In addition, the present inventors combined the above-mentioned polymer having a polycarbonate structure with a specific acrylic polymer, exhibiting good adhesive properties to various adherends, and exhibiting creep properties and long-term durability. It has been found that an excellent pressure-sensitive adhesive composition can be obtained. That is, the present invention is a pressure-sensitive adhesive composition comprising an acrylic polymer having a glass transition temperature of −10 ° C. or less together with a polymer having a polycarbonate structure in a proportion of 10 to 90% by weight in the total amount with the above polymer.Adhesive sheets having the above structure usingCan provide.
[0010]
  Furthermore, the present inventors, when combined with the above-mentioned polymer having a polycarbonate structure and a specific resin, satisfy the creep resistance and adhesiveness in a high temperature range and are excellent in impact resistance at a low temperature. It has been found that a composition can be obtained. That is, the present invention is a pressure-sensitive adhesive composition comprising a polymer having a polycarbonate structure and a resin having a softening point of 80 ° C. or higher in a proportion of 10 to 50% by weight in the total amount with the polymer.Adhesive sheets having the above structure usingCan be provided.
[0011]
  Furthermore,In such pressure-sensitive adhesive sheets, a release liner is usually bonded to the pressure-sensitive adhesive surface. The present inventors can use a release liner that is not subjected to silicone treatment, such as a polyethylene film or a polypropylene film, as the release liner. In other words, it is possible to obtain pressure-sensitive adhesive sheets having excellent releasability of the liner due to the characteristics of the pressure-sensitive adhesive composition and exhibiting good adhesive force. And found that it can provide adhesive sheets.
[0012]
That is, the present invention is a pressure-sensitive adhesive sheet having a layer composed of the pressure-sensitive adhesive composition having the above-mentioned various configurations, and having a release liner not subjected to a silicone treatment bonded to the pressure-sensitive adhesive surface. The release liner not subjected to the silicone treatment is a polyolefin film made of polyethylene, polypropylene, an ethylene-propylene copolymer or a mixture thereof, or a film whose surface is processed with the same polyolefin as described above. It is possible to provide an adhesive sheet in which the peeling force of the release liner is 200 g / 50 mm width or less.
[0013]
In addition, when the present inventors provide the pressure-sensitive adhesive composition having the above-mentioned various configurations on one side of the substrate, the layer comprising the pressure-sensitive adhesive composition is formed by forming at least the back side of the substrate with polyolefin such as polyethylene or polypropylene. It has been found that an adhesive sheet can be obtained that has good releasability from the back surface of the substrate and can be wound into a roll without interposing a release liner. That is, according to this adhesive sheet, since it does not have a release liner and it is not necessary to perform a silicon release treatment on the back of the substrate, the adhesive sheet does not substantially contain a silicone compound. For example, it can be used for a computer device in which the inclusion of silicon is likely to be a problem.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
In the pressure-sensitive adhesive composition of the present invention, the storage elastic modulus [G ′] at room temperature is 2 × 10.⁶ dyne / cm² Or more, preferably 3 × 10⁶ dyne / cm² Above, particularly preferably 5 × 10⁶ dyne / cm² Above, usually 5 × 10⁷ dyne / cm² It is as follows and does not show high tack as an adhesive, and therefore hardly adheres in a short time of about several seconds. For this reason, if it is a short time, it can be peeled off once and used again, and the bonding position can be corrected without damaging the adherend. In addition, since it does not adhere in a short time, the adhesive sheet is not attached to the blade for processing at the time of cutting, so that the blade is not contaminated.
[0015]
In addition, the pressure-sensitive adhesive composition of the present invention has the above-mentioned high elasticity and tack-free property, and has an adhesive strength at room temperature of 1 kg / 20 mm width or more, preferably 1.5 kg / 20 mm width or more, and usually 10 kg / 20 mm width or less. It has a unique and useful characteristic of exhibiting high adhesive force without requiring complicated processes such as heat treatment, and this characteristic makes it possible for conventional adhesive compositions to An excellent effect is achieved in that it is possible to achieve both the adhesion workability and the adhesiveness which have been difficult.
[0016]
In such a pressure-sensitive adhesive composition, the storage elastic modulus [G ′] at −30 ° C. is 3 × 10.⁷ dyne / cm² Or less, preferably 2 × 10⁷ dyne / cm² Below, usually 5 × 10⁶ dyne / cm² In this case, the effect of excellent impact resistance at low temperatures can be obtained. Further, the storage elastic modulus [G ′] at 80 ° C. is 1 × 10.⁶ dyne / cm² Or more, preferably 3 × 10⁶ dyne / cm² Above, usually 5 × 10⁷ dyne / cm² In this case, a high cohesive force is exhibited even at a high temperature of 80 ° C., and excellent adhesion and holding properties can be obtained.
[0017]
The pressure-sensitive adhesive composition of the present invention is not particularly limited in composition as long as it has the above storage elastic modulus [G ′] and the above-mentioned adhesive strength, but generally, a polyisocyanate is used as a polymer for forming a pressure-sensitive adhesive. A cross-linking agent such as a compound is added to carry out a cross-linking treatment, and the storage elastic modulus [G ′] and adhesive strength set according to the selection of the polymer and the degree of the cross-linking treatment are preferably used. Here, as the polymer for the pressure-sensitive adhesive composition, a polymer having a polycarbonate structure is represented by the following formula:

(In the formula, R is a linear or branched hydrocarbon group having 2 to 20 carbon atoms)
A polymer having a repeating unit represented by
[0018]
This polymer includes polyesters synthesized from polycarbonate diols (or their derivatives) and dicarboxylic acids (or their derivatives), polyesters synthesized from polycarbonate dicarboxylic acids and diols. Polyurethanes synthesized from polycarbonate diols and diisocyanates, among which polyesters synthesized from polycarbonate diols and dicarboxylic acids are particularly preferred. This type of polyester has a diol component essentially composed of polycarbonate diol and a dicarboxylic acid whose molecular skeleton is an aliphatic or alicyclic hydrocarbon group having 2 to 20 carbon atoms. It is synthesized from a dicarboxylic acid component and has a weight average molecular weight of 10,000 or more, preferably 30,000 or more, particularly preferably 50,000 or more (usually up to 300,000).
[0019]
The polycarbonate diol used here has the following formula:

(In the formula, R is a linear or branched hydrocarbon group having 2 to 20 carbon atoms)
The number average molecular weight is preferably 400 or more, preferably 900 or more (usually up to 10,000). Examples of such polycarbonate diols include polyhexamethylene carbonate diol, poly (3-methylpentene carbonate) diol, and polypropylene carbonate diol. There is a mixture thereof or a copolymer thereof. Commercially available products include “PLACCEL CD205PL”, “CD208PL”, “CD210PL”, “CD220PL”, “CD205HL”, “CD208HL”, “CD210HL”, “CD210HL”, and “Same CD210HL” manufactured by Daicel Chemical Industries, Ltd. CD220HL "and the like.
[0020]
As the diol component, in addition to the above polycarbonate diol, ethylene glycol, propylene glycol, butane diol, hexane diol, octane diol, decane diol, octadecane diol as necessary. Ingredients such as a linear diol or branched diol, such as a kell, may be used in combination. These other diols may be used in an amount of 50% by weight or less, preferably 30% by weight or less of the entire diol component. In order to increase the molecular weight of the polymer, a small amount of a tri- or higher functional polyol component may be added.
[0021]
In addition, the dicarboxylic acid component has an aliphatic or alicyclic hydrocarbon group having 2 to 20 carbon atoms as a molecular skeleton, and the hydrocarbon group may be linear or branched. May be hot. Specifically, succinic acid, methyl succinic acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, 1,12-dodecanedioic acid, 1,14-tetradecanedioic acid, tetrahydrophthalic acid, endomethylenetetrahydrophthalic acid, these And acid anhydrides and lower alkyl esters.
[0022]
As the dicarboxylic acid component, it is desirable to use a dicarboxylic acid having a molecular skeleton of an aliphatic or alicyclic hydrocarbon group having 2 to 20 carbon atoms as described above, but in some cases, together with the dicarboxylic acid, Dicarboxylic acids having an aromatic hydrocarbon group as a molecular skeleton may be appropriately mixed and used. The amount of dicarboxylic acid having an aromatic hydrocarbon group as a molecular skeleton is preferably 50% by weight or less, particularly preferably 30% by weight or less, based on the entire dicarboxylic acid component. Further, for the purpose of increasing the molecular weight of the synthesized polyester, a small amount of a trifunctional or higher polyvalent carboxylic acid component can be added.
[0023]
Polyester can be obtained by subjecting the above diol component and dicarboxylic acid component to an esterification reaction using a non-catalyst or an appropriate catalyst according to a conventional method. In this case, the diol component and the dicarboxylic acid component are preferably equimolar reaction, but in order to promote the esterification reaction, either of them may be used in excess. The polyester thus obtained preferably has the molecular weight. This is because if the molecular weight is too low, the highly crosslinked pressure-sensitive adhesive has a high crosslinking density, and has a very hard property, or conversely, if the crosslinking density is set low, the molecular weight of the uncrosslinked component is low. This is because it is not preferable in terms of heat resistance.
[0024]
In the present invention, a polymer having a polycarbonate structure such as polyester is usually subjected to a crosslinking treatment by an appropriate means, and the storage elastic modulus [G ′] and adhesive strength at room temperature are within the above ranges. The pressure-sensitive adhesive composition is as follows. Any crosslinking means may be used, but a polyfunctional compound such as a polyisocyanate compound, an epoxy compound, an aziridine compound, a metal chelate compound, a metal alkoxide compound is used as a crosslinking agent, and this and the above polymer (included in the above). A method of crosslinking by reacting with a hydroxyl group or a carboxyl group is common. As the polyfunctional compound, a polyisocyanate compound is particularly preferable.
[0025]
Polyisocyanate compounds include lower aliphatic polyisocyanates such as ethylene diisocyanate, butylene diisocyanate, hexamethylene diisocyanate, cyclopentylene diisocyanate, cyclohexylene diisocyanate. Alicyclic polyisocyanates such as neat and isophorone diisocyanate, 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate And aromatic polyisocyanates such as In addition, tolylene diisocyanate adduct of trimethylolpropane (“Coronate L” manufactured by Nippon Polyurethane Co., Ltd.), hexamethylene diisocyanate adduct of trimethylolpropane (manufactured by Nippon Polyurethane Co., Ltd.) "Colonate HL"] is also used.
[0026]
  These polyfunctional compounds are used alone or in a mixture of two or more. The amount used is appropriately selected according to the balance with the polymer to be crosslinked and according to the purpose of use of the pressure-sensitive adhesive composition. In general, 0.5 parts by weight or more, preferably about 1 to 5 parts by weight per 100 parts by weight of a polymer having a polycarbonate structure is blended and crosslinked. Thereby, the solvent insoluble content of the polymer is 10 to 10.65% By weight, preferably 15-65% By weight, more preferably 20 to65A pressure-sensitive adhesive composition having a weight percent is obtained. If the solvent-insoluble content of the polymer is too small, the cohesive force of the pressure-sensitive adhesive is insufficient, and sufficient elastic modulus, heat resistance, and durability cannot be obtained.
[0027]
As another crosslinking means, there is a method in which a polyfunctional monomer is blended with a polymer as a crosslinking agent, and this is crosslinked with an electron beam or the like. Polyfunctional monomers include ethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, trimethylolpropane tri (meth) acrylate, etc. There is. The amount of these polyfunctional monomers used is 1 per 100 parts by weight of the polyfunctional monomer so that the solvent-insoluble content of the polymer after crosslinking with an electron beam or the like has the same value as described above. It should be ˜5 parts by weight, preferably 2 to 4 parts by weight.
[0028]
The pressure-sensitive adhesive composition of the present invention uses the above-mentioned polymer structure having a polycarbonate structure as a base polymer, and is usually a cross-linked structure by means as described above. Various known tackifiers may be added to the product, and powders such as inorganic or organic fillers, metal powders, pigments, particulates, foils, anti-aging agents, plasticizers, etc. Various additives such as can be optionally included.
[0031]
In the present invention, an acrylic polymer having a glass transition temperature of −10 ° C. or less, together with a polymer having a polycarbonate structure, is preferably 10 to 90% by weight in the total amount of the above polymer, preferably By using it at a ratio of 15 to 85% by weight, in addition to the above-mentioned properties, it exhibits good adhesion to various adherends, and has excellent creep properties and long-term durability. Can be obtained.
[0032]
Conventionally, acrylic pressure-sensitive adhesives that do not contain tackifiers have poor adhesion to plastics, while acrylic or natural rubber-based pressure-sensitive adhesives that contain tackifiers have poor adhesion to plastics. Although relatively good, there were problems with poor creep characteristics and long-term durability. However, the above-mentioned pressure-sensitive adhesive composition of the present invention avoids such problems, and has excellent adhesion to various adherends, particularly plastics such as polycarbonate and acrylic resin, and also has creep characteristics. In addition, it is possible to provide a pressure-sensitive adhesive with excellent long-term durability.
[0033]
The acrylic polymer used here is a monomer polymer containing 50 to 100% by weight of a (meth) acrylate having an alkyl group having 4 to 14 carbon atoms, and has a glass transition temperature of − Those having a temperature of 10 ° C. or lower, particularly −15 ° C. or lower (usually up to about −90 ° C.) are preferably used. When the glass transition temperature is higher than −10 ° C., the initial adhesive strength is inferior, which is not preferable. Examples of the (meth) acrylate having an alkyl group having 4 to 14 carbon atoms include a butyl group, an isobutyl group, an isoamyl group, a hexyl group, a heptyl group, a 2-ethylhexyl group, an isooctyl group, an isononyl group, and a lauryl group. And alkyl esters of (meth) acrylic acid having an alkyl group such as an isomyristyl group.
[0034]
When such an acrylic polymer is used in combination, usually, the acrylic polymer and the polymer having the polycarbonate structure described above are synthesized separately, and then both are mixed in the form of a solution or a lump. Thus, a pressure-sensitive adhesive composition is prepared. However, depending on the case, it may be prepared by a method of polymerizing the other in one polymer, or may be prepared by any method when both are polymerized simultaneously.
[0035]
  In these preparation methods, the amount of the acrylic polymer used is such that the ratio of the acrylic polymer to the total amount with the polymer having a polycarbonate structure is within the above range. When the acrylic polymer is less than 10% by weight, the initial adhesiveness is low, and when it exceeds 90% by weight, the adhesiveness to the plastic is low. In addition, one or both of the acrylic polymer and the polymer having a polycarbonate structure are subjected to a crosslinking treatment by the above-described method.65% By weight, preferably 15-65% By weight, more preferably 20 to65It is better to be in the range of wt%. If the solvent-insoluble content is low, the creep properties and long-term durability are inferior, and if it is too high, the initial adhesiveness is inferior, which is not preferable.
[0036]
Furthermore, in the present invention, together with a polymer having a polycarbonate structure, a resin having a softening point of 80 ° C. or higher is 10 to 50% by weight, preferably 13 to 45% by weight, based on the total amount of the above polymer. More preferably, it is used at a ratio of 15 to 35% by weight, and in addition to the above-mentioned properties, it satisfies creep resistance and adhesion in a high temperature range, and also has excellent impact resistance at a low temperature. An agent composition can be obtained.
[0037]
Conventionally, as described in Japanese Patent Publication No. 56-13040, one obtained by adding a hot-melt resin to an adhesive composition is known. This is advantageous compared to the thermosetting type that requires a heat treatment of 100 ° C. or higher, and the work is simpler and does not require heat resistance to the adherend. There is a problem that it is difficult to achieve both creep resistance and adhesion. Japanese Patent Publication No. 2-50146 discloses an acrylic graft polymer having a polymer having a high glass transition temperature in the side chain, to which a hot-melt resin is added. This satisfies creep resistance and adhesiveness at high temperatures, but has a problem of poor impact resistance at low temperatures. However, the above-mentioned pressure-sensitive adhesive composition of the present invention does not have such a problem, satisfies the creep resistance and adhesiveness in a high temperature range, and has excellent impact resistance at a low temperature. A composition can be provided.
[0038]
  The resin used here has a softening point of 80 ° C. or higher, preferably 90 ° C. or higher, more preferably 100 ° C. or higher, and usually 150 ° C. or lower. When the softening point is lower than 80 ° C., creep resistance and adhesive strength at high temperatures are lowered, which is not preferable. Examples of the resin include terpene, rosin, alkylphenol, terpenephenol, rosinphenol, coumarone-indene, aromatic petroleum, and aliphatic petroleum. When the proportion of this type of resin in the total amount with the polymer having a polycarbonate structure is less than 10% by weight, the shear adhesive strength is lowered, and when it exceeds 50% by weight, the impact resistance at low temperature is inferior. Moreover, the solvent-insoluble matter after the crosslinking treatment containing this resin is 10 to 10.65% By weight, preferably 15-65% By weight, more preferably 20 to65It should be in the range of% by weight. When the solvent-insoluble content is too low, the durability is inferior, and when it is too high, the adhesiveness is inferior.
[0039]
The pressure-sensitive adhesive sheets of the present invention have a sheet-like or tape-like form of the pressure-sensitive adhesive composition having the above-described various configurations, that is, at least a layer composed of the pressure-sensitive adhesive composition having the above-described configuration. For this purpose, first, a layer made of the above-mentioned pressure-sensitive adhesive composition is applied on a release liner so that the thickness after drying is usually about 10 to 150 μm, and is necessary on the layer. Further, a so-called base-less double-sided pressure-sensitive adhesive sheet obtained by further laminating the above release liner is included. In this case, in order to improve the adhesive property, another adhesive composition may be used to form a multilayer structure.
[0040]
In addition, as a more general adhesive sheet, a plastic film such as a polyester film, a porous material such as paper or nonwoven fabric, or a metal foil is used. A layer composed of a pressure-sensitive adhesive composition is applied so that the thickness after drying is usually about 10 to 150 μm on one side, the pressure-sensitive adhesive layer is supported on a substrate, and a release liner is bonded to the pressure-sensitive adhesive surface. The single-sided or double-sided pressure-sensitive adhesive sheets with a base material can be obtained. In this case, in order to improve the adhesive property, another adhesive composition may be used to form a multilayer structure. In such adhesive sheets with a base material and the above-mentioned double-sided adhesive sheets without a base material, the crosslinking treatment of a polymer having a polycarbonate structure or the like is carried out as described above. It can be applied as appropriate during or after the manufacturing process of the tomatoes.
[0041]
In the present invention, in such an adhesive sheet, it is possible to use a release liner made of polyethylene film, polypropylene film, or the like that has not been subjected to silicone treatment as a release liner to be bonded to the adhesive surface. . That is, even when such a release liner is used, the release force of this liner is 200 g / 50 mm width or less, preferably 100 g / 50 mm width or less, more preferably 50 g / 50 mm width or less (usually up to 1 g / 50 mm width). ) Is obtained, and the above-mentioned good adhesive force can be maintained.
[0042]
For acrylic and rubber-based adhesives, if a polyethylene film or polypropylene film is used as the release liner, the release force becomes 500g / 50mm width or more, and the release workability decreases. The use of was inevitable. In the present invention, since the peeling force can be set to 200 g / 50 mm width or less by using a release liner that has not been subjected to a silicon treatment, the liner can be easily removed, and a normally used silicone is used. It can be handled in the same way as the adhesive tape product of the treated release liner. For this reason, it is not necessary to change the apparatus, work procedure, etc. associated with the change from the silicon treatment release liner to the release liner.
[0043]
Thus, in the adhesive sheet of the present invention, it is possible to produce an adhesive sheet containing no silicone at all by using a polyethylene film or a polypropylene film as a release liner. As a result, it is possible to provide adhesive sheets suitable for computer equipment, etc., in which the inclusion of silicone is likely to be a problem. In addition, when the release liner is a simple film material such as polyethylene or polypropylene, it is possible to obtain an effect of excellent plastic recyclability, which has been particularly problematic in recent years.
[0044]
The release liner not subjected to the silicon treatment used in the present invention includes a polyolefin film made of polyethylene, polypropylene, an ethylene-propylene copolymer (block or random copolymer) or a mixture thereof, or a surface thereof. The same polyolefins as described above, that is, films processed with polyethylene, polypropylene, ethylene-propylene copolymer (block or random copolymer) or a mixture thereof can be mentioned. Examples of the film on which the latter surface has been processed include a laminate of paper or other film and the above polyolefin film.
[0045]
On the other hand, in the present invention, as a pressure-sensitive adhesive sheet that does not use such a release liner, a layer made of the pressure-sensitive adhesive composition having the above-described structure is provided on one side of the base material in the same thickness as described above. It is also possible to obtain a pressure-sensitive adhesive sheet having at least the back side composed of polyolefin comprising polyethylene, polypropylene, ethylene-propylene copolymer (block or random copolymer) or a mixture thereof.
[0046]
This type of adhesive sheet is characterized in that the back side of the base material is not treated with silicone, but the peelability between the layer made of the adhesive composition and the back side of the base material is good. It is possible to wind in a roll without interposing a release liner. As described above, since there is no release liner and it is not necessary to release the back surface of the base material with a silicone compound, the adhesive sheet containing substantially no silicone compound is used as a computer. It can be used advantageously for equipment. In addition, as long as the anchoring property of the layer which consists of an adhesive composition and a base material can be ensured, not only the back side of a base material but the whole base material may be comprised with the same polyolefin.
[0047]
【Example】
Next, examples of the present invention will be described in more detail. Hereinafter, parts are based on weight. The weight average molecular weight of the polymer is a value in terms of polystyrene as determined by gel permeation chromatography.
[0048]
Example 1-1
In a four-necked separable flask equipped with a stirrer, thermometer and water separation tube, polycarbonate diol (PLACCEL CD210PL manufactured by Daicel Chemical Industries, Ltd., hydroxyl value 115 KOHmg / g) 250 g (hydroxyl group: 0) 512 equivalents), 51.8 g of sebacic acid (acid group: 0.512 equivalents), 127 mg of dibutyltin oxide (hereinafter referred to as DBTO) as a catalyst, and stirring in the presence of a small amount of toluene as a reaction water discharge solvent The temperature was raised to 180 ° C. while starting and was maintained at this temperature. After a while, water separation was observed and the reaction started to proceed. The reaction was continued for about 24 hours to obtain a polyester having a weight average molecular weight of 55,000.
[0049]
After diluting this polyester with toluene to a solid content concentration of 40% by weight, per 100 parts of polyester (solid content), trimethylolpropane hexamethylene diisocyanate adduct as a cross-linking agent [corrosion made by Nippon Polyurethane Co., Ltd. -HL] 2 parts (solid content) was added to obtain an adhesive composition. This is coated on a polyethylene terephthalate film (hereinafter referred to as PET film) with a thickness of 38 μm by an applicator and dried at 130 ° C. for 5 minutes to form an adhesive layer with a thickness of 50 μm. Further, as an aftercare, aging was carried out for 5 days in an atmosphere at 50 ° C. to prepare an adhesive tape. Further, in the same manner as described above, a pressure-sensitive adhesive layer having a thickness of 50 μm was formed on a release paper for storage elastic modulus measurement.
[0050]
Example 1-2
In a four-necked separable flask equipped with a stirrer, thermometer and water separation tube, polycarbonate diol (PLACCEL CD220PL manufactured by Daicel Chemical Industries, Ltd., hydroxyl value 56.1 KOHmg / g) 250 g (hydroxyl group) : 0.25 equivalent), 23.5 g of azelaic acid (acid group: 0.25 equivalent), 62 mg of DBTO as a catalyst, 180 ° C. while stirring in the presence of a small amount of toluene as a reaction water discharge solvent The temperature was raised to and maintained at this temperature. After a while, water separation was observed and the reaction started to proceed. The reaction was continued for about 25 hours to obtain a polyester having a weight average molecular weight of 78,000.
[0051]
After diluting this polyester with toluene to a solid content concentration of 40% by weight, a tridiene propane tolylene diisocyanate adduct as a cross-linking agent per 100 parts of polyester (solid content) [Corone from Nippon Polyurethane Co., Ltd. G] 1.5 parts (solid content) was added to obtain an adhesive composition. This pressure-sensitive adhesive composition was coated on a PET film having a thickness of 38 μm by an applicator and dried at 130 ° C. for 5 minutes to form a pressure-sensitive adhesive layer having a thickness of 50 μm. As a result, aging was performed in an atmosphere at 50 ° C. for 5 days to prepare an adhesive tape. Further, in the same manner as described above, a pressure-sensitive adhesive layer having a thickness of 50 μm was formed on a release paper for storage elastic modulus measurement.
[0052]
Example 1-3
Instead of Coronate L, 2.5 parts of trimethylolpropane hexamethylene diisocyanate adduct [Coronate HL manufactured by Nippon Polyurethane Co., Ltd.] (solid content) is added as a crosslinking agent. A pressure-sensitive adhesive tape was produced in the same manner as in Example 1-2, except for the above. Further, in the same manner as described above, a pressure-sensitive adhesive layer having a thickness of 50 μm was formed on a release paper for storage elastic modulus measurement.
[0053]
Example 1-4
In a four-necked separable flask equipped with a stirrer, thermometer and water separation tube, polycarbonate diol (PLACCEL CD220PL manufactured by Daicel Chemical Industries, Ltd., hydroxyl value 56.1 KOHmg / g) 250 g (hydroxyl group) : 0.25 equivalent), 12.6 g of sebacic acid and 11.8 g of azelaic acid (total acid groups: 0.25 equivalent), 62 mg of DBTO as a catalyst were charged, and in the presence of a small amount of toluene as a reaction water discharge solvent, While starting stirring, the temperature was raised to 180 ° C. and kept at this temperature. After a while, water separation was observed and the reaction started to proceed. The reaction was continued for about 25 hours to obtain a polyester having a weight average molecular weight of 75,000.
[0054]
After diluting this polyester with toluene to a solid content concentration of 40% by weight, per 100 parts of polyester (solid content), trimethylolpropane hexamethylene diisocyanate adduct as a cross-linking agent [corrosion made by Nippon Polyurethane Co., Ltd. -HL] 2 parts (solid content) was added to obtain an adhesive composition. This pressure-sensitive adhesive composition was coated on a PET film having a thickness of 38 μm by an applicator and dried at 130 ° C. for 5 minutes to form a pressure-sensitive adhesive layer having a thickness of 50 μm. As a result, aging was performed in an atmosphere at 50 ° C. for 5 days to prepare an adhesive tape. Further, in the same manner as described above, a pressure-sensitive adhesive layer having a thickness of 50 μm was formed on a release paper for storage elastic modulus measurement.
[0055]
Comparative Example 1-1
In a reaction vessel equipped with a stirrer and a thermometer, 95 parts of n-butyl acrylate, 5 parts of acrylic acid, 150 parts of toluene, and 0.1 part of azobisisobutyronitrile were placed in a nitrogen gas atmosphere at 60 ° C. The solution was polymerized for 7 hours to obtain a polymer solution. To 100 parts (solid content) of this polymer, add 2 parts (solid content) of trimethylolpropane tolylene diisocyanate adduct [Coronate L manufactured by Nippon Polyurethane Co., Ltd.] as a cross-linking agent. An agent composition was obtained. This pressure-sensitive adhesive composition was coated on a PET film having a thickness of 38 μm by an applicator and dried at 130 ° C. for 5 minutes to form a pressure-sensitive adhesive layer having a thickness of 50 μm. As a result, aging was performed in an atmosphere at 50 ° C. for 5 days to prepare an adhesive tape. Further, in the same manner as described above, a pressure-sensitive adhesive layer having a thickness of 50 μm was formed on a release paper for storage elastic modulus measurement.
[0056]
Comparative Example 1-2
In a reaction vessel equipped with a stirrer and a thermometer, 80 parts of 2-ethylhexyl acrylate, 20 parts of acrylic acid, and 0.6 parts of Irgakia-184 (manufactured by Ciba Geigy Co., Ltd.) as a photopolymerization initiator are placed, and nitrogen gas is thoroughly replaced. After that, about 100mj / cm by high pressure mercury lamp² Was irradiated with ultraviolet rays. To the viscous material obtained by this irradiation, 1 part of trimethylolpropane triacrylate was blended as an internal cross-linking agent to prepare an adhesive composition. This pressure-sensitive adhesive composition was applied on a PET film having a thickness of 38 μm by an applicator so as to have a thickness of 50 μm. Then, in order to eliminate the polymerization inhibition by oxygen, it is covered with a PET peeling liner, and about 1,400 mj / cm with a high-pressure mercury lamp.² A pressure-sensitive adhesive layer was formed by irradiating ultraviolet rays at an irradiation amount of 5 to produce a pressure-sensitive adhesive tape. Further, in the same manner as described above, a pressure-sensitive adhesive layer having a thickness of 50 μm was formed on a release paper for storage elastic modulus measurement.
[0057]
About each adhesive tape of said Example 1- (1-4) and Comparative Example 1- (1,2), each storage elastic modulus in -30 degreeC, room temperature (23 degreeC), and 80 degreeC, and room temperature ( The adhesive strength at 23 ° C. (180 ° peel adhesive strength) was examined by the following method. These measurement results were as shown in Table 1.
[0058]
<Storage modulus>
The storage elastic modulus [G ′] refers to the shear storage elastic modulus of the pressure-sensitive adhesive composition, and should be called an elastic component that stores energy applied from the outside as strain energy. ′] Is measured using a dynamic viscoelasticity measuring device RDS-II manufactured by Rheometrics Co., Ltd., using a parallel plate jig having a sample thickness of about 1.5 mm and a diameter of 7.9 mm at a frequency of 1 Hz. I went by this method.
[0059]
<Adhesive strength>
Adhesive tape is affixed to an acrylic plate (polymethyl methacrylate) as an adherend, and 180 ° peel adhesion is achieved under conditions of an ambient temperature of 23 ° C., a sticking time of 30 minutes, and a peel speed of 300 mm / min. It was measured.
[0060]
Table 1

[0061]
Next, with respect to each of the adhesive tapes of Examples 1- (1 to 4) and Comparative Example 1- (1,2), the finger tack at room temperature (23 ° C.) and heat resistance were performed as follows. The property (80 ° C.) was measured. These results were as shown in Table 2 below.
[0062]
<Measurement of thumb tack>
At room temperature (23 ° C.), the thumb was touched on the surface of the adhesive tape, pressed for a short time (about 1 second), then pulled away, and evaluated by the resistance felt on the thumb surface at that time.
[0063]
<Measurement of heat resistance>
Adhesive tape is affixed to a Bakelite plate as an adherend, and the ambient temperature is 80 ° C. and the vertical direction is 500 g / 2 cm.² The load was measured and the holding time (min) until dropping was measured.
[0064]
Table 2

[0065]
From the results of Table 1 and Table 2 above, each adhesive tape of Example 1- (1-4) of the present invention is higher than the adhesive tape of Comparative Example 1- (1-2). It can be seen that it is elastic and tack-free, yet has high adhesion and is satisfactory in terms of heat resistance.
[0066]
Example 2-1
In a four-necked separable flask equipped with a stirrer, thermometer, and water separation tube, polycarbonate diol (PLACCEL CD210PL manufactured by Daicel Chemical Industries, Ltd., hydroxyl value 115.0 KOHmg / g) 200 g (hydroxyl group: 0.41 equivalent), 20.51 g of succinic anhydride (acid group: 0.41 equivalent), 102 mg of DBTO as a catalyst, 180 ° C. with stirring in the presence of a small amount of toluene as a reaction water discharge solvent The temperature was raised to and maintained at this temperature. After a while, water outflow separation was observed, and the reaction started to proceed. The reaction was continued for about 27 hours to obtain a polyester having a weight average molecular weight of 56,000.
[0067]
After diluting this polyester with toluene to a solid content concentration of 50% by weight, per 100 parts of polyester (solid content), trimethylolpropane hexamethylene diisocyanate adduct as a cross-linking agent [corrosion made by Nippon Polyurethane Co., Ltd. -HL] 1.5 parts (solid content) was added to prepare an adhesive composition. This was coated on a PET film having a thickness of 38 μm by an applicator, dried at 130 ° C. for 5 minutes to form a pressure-sensitive adhesive layer having a thickness of 50 μm, and an after-heater having a temperature of 50 ° C. An adhesive tape was prepared by aging for 5 days in an atmosphere.
[0068]
Example 2-2
In a four-necked separable flask equipped with a stirrer, thermometer, and water separation tube, polycarbonate diol (PLACCEL CD210PL manufactured by Daicel Chemical Industries, Ltd., hydroxyl value 115.0 KOHmg / g) 250 g (hydroxyl group: 0.512 equivalents), 37.44 g of adipic acid (acid group: 0.512 equivalents), 127 mg of DBTO as a catalyst, and up to 180 ° C. while stirring in the presence of a small amount of toluene as a reaction water discharge solvent The temperature was raised and held at this temperature. After a while, water outflow separation was observed, and the reaction started to proceed. The reaction was continued for about 30 hours to obtain a polyester having a weight average molecular weight of 58,000.
[0069]
After diluting this polyester with toluene to a solid content concentration of 50% by weight, a trimethylolpropane tolylene diisocyanate adduct as a cross-linking agent per 100 parts of polyester (solid content) [Corone from Nippon Polyurethane Co., Ltd. G] 1.5 parts (solid content) was added to prepare an adhesive composition. This was coated on a PET film having a thickness of 38 μm by an applicator, dried at 130 ° C. for 5 minutes to form a pressure-sensitive adhesive layer having a thickness of 50 μm, and an after-heater having a temperature of 50 ° C. An adhesive tape was prepared by aging for 5 days in an atmosphere.
[0070]
Example 2-3
In a four-necked separable flask equipped with a stirrer, a thermometer, and a water separation tube, polycarbonate diol (PLACCEL CD220PL manufactured by Daicel Chemical Industries, Ltd., hydroxyl value 56.1 KOHmg / g) 250 g (hydroxyl group: 0.25 equivalent), 25.28 g of sebacic acid (acid group: 0.25 equivalent), 62 mg of DBTO as a catalyst, and up to 180 ° C. with stirring in the presence of a small amount of toluene as a reaction water discharge solvent The temperature was raised and held at this temperature. After a while, water outflow separation was observed, and the reaction started to proceed. The reaction was continued for about 25 hours to obtain a polyester having a weight average molecular weight of 72,000.
[0071]
After diluting this polyester with toluene to a solid content concentration of 50% by weight, per 100 parts of polyester (solid content), trimethylolpropane hexamethylene diisocyanate adduct as a cross-linking agent [corrosion made by Nippon Polyurethane Co., Ltd. -HL] 2 parts (solid content) was added to prepare an adhesive composition. This was coated on a PET film having a thickness of 38 μm by an applicator, dried at 130 ° C. for 5 minutes to form a pressure-sensitive adhesive layer having a thickness of 50 μm, and an after-heater having a temperature of 50 ° C. An adhesive tape was prepared by aging for 5 days in an atmosphere.
[0072]
Example 2-4
After the polyester obtained in Example 2-3 was diluted with toluene to a solid concentration of 50% by weight, 3 parts of trimethylolpropane triacrylate (solid content) as a crosslinking agent per 100 parts of polyester (solid content) Was added to prepare an adhesive composition. This was coated on a PET film having a thickness of 38 μm by an applicator, dried at 100 ° C. for 5 minutes to form an adhesive layer having a thickness of 50 μm, and further irradiated with 6 Mrad of an electron beam, An adhesive tape was prepared.
[0073]
About each adhesive tape of said Example 2- (1-4), the solvent insoluble content of polyester, adhesive force, and heat resistance were measured. These measurement results were as shown in Table 3 below. The solvent insolubles and adhesive strength were measured by the following methods, and the heat resistance was measured by the above methods.
[0074]
<Measurement of solvent insolubles>
About 0.1 g of the adhesive was sampled from the adhesive tape and weighed accurately. This was immersed in about 50 ml of toluene at room temperature for 5 days, the solvent-insoluble matter was taken out, dried at 130 ° C. for about 1 hour, and weighed. The solvent insoluble content [X] (% by weight) was calculated by the following formula.

[0075]
<Measurement of adhesive strength>
Adhesive tape is affixed to a polycarbonate plate or acrylic plate (polymethyl methacrylate) as an adherend. Atmospheric temperature: 23 ° C, affixing time: 30 minutes, peeling rate: 300 mm / min. Then, 180 ° peel adhesion was measured.
[0076]
Table 3

[0077]
As is clear from the results in Table 3 above, each adhesive tape using the adhesive composition of Example 2- (1-4) of the present invention has good adhesive strength. In addition, it can be seen that the heat resistance is also excellent.
[0094]
Example 4-1
In a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer, and a stirring device, 50 parts of ethyl acetate and 50 parts of toluene are used as solvents, 80 parts of 2-ethylhexyl acrylate, 12 parts of n-butyl acrylate, 8 parts of acrylic acid Part, 0.1 part of 2-hydroxyethyl acrylate, 0.1 part of 2,2′-azobisisobutyronitrile, polymerized in a nitrogen stream, glass transition temperature of −43 ° C., weight average molecular weight A solution of an acrylic polymer A having a molecular weight of 600,000 was obtained.
[0095]
Separately, in a reaction vessel equipped with a thermometer, a stirrer, and a water separation tube, as a polycarbonate diol, PLACEL CD220PL (hydroxyl value 56.1 KOHmg / g) 100 manufactured by Daicel Chemical Industries, Ltd. Part, 10.1 part of sebacic acid and 0.025 part of DBTO as a catalyst were added, and the temperature was raised to 180 ° C. with stirring in the presence of toluene as a reaction water discharge solvent. After a while, water outflow separation was observed. By performing the reaction for about 24 hours, a solution of polyester polymer B having a weight average molecular weight of 60,000 was obtained.
[0096]
The above acrylic polymer A solution and the above polyester polymer B solution are mixed so as to be 20 parts of a polyester polymer B per 80 parts of the acrylic polymer A, and further trimethylolpropane trimethyl is added thereto. 2 parts of diisocyanate adduct was added and mixed to prepare a solution of the pressure-sensitive adhesive composition. Next, this pressure-sensitive adhesive composition solution was applied to one side of a 38 μm thick polyester film so that the thickness after drying was 50 μm, dried at 120 ° C. for 2 minutes, and then the pressure-sensitive adhesive tape. Was made. Moreover, it applied to the single side | surface of the polyester film which performed the peeling process similarly to the above, and produced the sample for a solvent insoluble content measurement.
[0097]
Example 4-2
The solution of the acrylic polymer A obtained in Example 4-1 and the solution of the polyester polymer B were mixed so as to be 50 parts of the polyester polymer B per 50 parts of the acrylic polymer A, and trimethylo was further added thereto. -Toluene diisocyanate adduct 2 parts of rupropane was added and mixed to prepare a solution of an adhesive composition. Using this solution, an adhesive tape was prepared in the same manner as in Example 4-1. Moreover, the sample for solvent insoluble content measurement was produced like Example 4-1.
[0098]
Example 4-3
The solution of the acrylic polymer A obtained in Example 4-1 and the solution of the polyester polymer B were mixed so that the polyester polymer B was 80 parts per 20 parts of the acrylic polymer A, and this was further trimethylo. -Toluene diisocyanate adduct 2 parts of rupropane was added and mixed to prepare a solution of an adhesive composition. Using this solution, an adhesive tape was prepared in the same manner as in Example 4-1. Moreover, the sample for solvent insoluble content measurement was produced like Example 4-1.
[0099]
Example 4-4
The polyester polymer B solution obtained in Example 4-1 was coated on a separator and dried at 80 ° C. for 1 hour to obtain a solid content of the polyester polymer B. 40 parts of this solid content was mixed with 48 parts of 2-ethylhexyl acrylate, 12 parts of acryloylmorpholine and 0.06 parts of 2-hydroxyethyl acrylate (the glass transition temperature of the copolymer of this mixture was -40 And 0.1 parts of 2,2-dimethoxy-2-phenylacetophenone and 2 parts of a tolylene diisocyanate adduct of trimethylolpropane were added and mixed.
[0100]
This mixed solution is applied to one side of a 38 μm thick polyester film so that the thickness after irradiation with ultraviolet rays is 50 μm, and then irradiated with ultraviolet rays to polymerize and cure the monomer mixture. Thus, an adhesive tape was produced. Moreover, it applied to the single side | surface of the polyester film which performed the peeling process similarly to the above, and irradiated the ultraviolet-ray, and produced the sample for a solvent insoluble content measurement.
[0101]
Reference Example 4-1
To the polyester polymer B solution obtained in Example 4-1, 2 parts of a trimethylolpropane tolylene diisocyanate adduct per 100 parts of the polyester polymer B were added and mixed, and the adhesive composition of A solution was prepared. Using this solution, an adhesive tape was prepared in the same manner as in Example 4-1. Moreover, the sample for solvent insoluble content measurement was produced like Example 4-1.
[0102]
Comparative Example 4-1
To the acrylic polymer A solution obtained in Example 4-1, 2 parts of a trimethylol propane tolylene diisocyanate adduct per 100 parts of the acrylic polymer A was added and mixed, and the pressure sensitive adhesive composition A solution was prepared. Using this solution, an adhesive tape was prepared in the same manner as in Example 4-1. Moreover, the sample for solvent insoluble content measurement was produced like Example 4-1.
[0103]
Comparative Example 4-2
Into the acrylic polymer A solution obtained in Example 4-1, per 80 parts of acrylic polymer A, polycarbonate diol [PLACCEL CD220PL manufactured by Daicel Chemical Industries, Ltd., hydroxyl value 56.1 KOHmg / g] Twenty parts and 2 parts of a tolylene diisocyanate adduct of trimethylolpropane were added and mixed to prepare a solution of an adhesive composition. Using the solution of the pressure-sensitive adhesive composition, a pressure-sensitive adhesive tape was prepared in the same manner as in Example 4-1. Moreover, the sample for solvent insoluble content measurement was produced like Example 4-1.
[0104]
About each adhesive tape produced in said Example 4- (1-4), Reference example 4-1, and Comparative example 4- (1,2), the adhesive force and the retention strength were measured with the following method. . The measurement results are shown in Table 5 below together with the solvent-insoluble content of the pressure-sensitive adhesive composition measured by the above method. In the table, “X” in the column for solvent insolubles is used.₁"Uses toluene as the solvent and" X₂"Is a measurement result when using ethyl acetate as a solvent, and in the case of ethyl acetate, after being immersed in this solvent at room temperature for 3 days, dried at 100 ° C for 2 hours, weighed and calculated.
[0105]
<Adhesive strength>
A 20mm x 100mm adhesive tape is pressure-bonded to the adherend by reciprocating a 2Kg roller once and left at 23 ° C for 20 minutes and at 70 ° C for 48 hours, then at 23 ° C and 65% RH atmosphere. The 180 ° peel adhesion was measured at a tensile rate of 300 mm / min. As the adherend, a polycarbonate plate, a polyacryl plate, and a stainless plate (SUS430BA) were used. In Table 5, “A” is a polycarbonate plate, “B” is an acrylic resin plate, and “C” is a stainless steel plate.
[0106]
<Retention force>
Adhesive tape with a width of 10 mm is attached to a phenolic resin plate with an adhesive area of 10 mm × 20 mm. After 20 minutes, the tape is left at 80 ° C. for 20 minutes. -A uniform load of 500 g was applied to the free end of the tape, and the dropping time (minute) of the adhesive tape at 80 ° C and the displacement distance (mm) after 120 minutes were measured.
[0107]
Table 5

[0108]
From Table 5 above, the adhesive tapes of Examples 4- (1 to 4) have a large adhesive force to various adherends, especially plastics such as polycarbonate and acrylic resin. It is clear that the holding force is large and the durability is excellent.
[0109]
Example 5-1
In a reaction vessel equipped with a thermometer, a stirrer, and a water separation tube, 100 parts of PLACEL CD220PL (hydroxyl value 56.1 KOHmg / g) manufactured by Daicel Chemical Industries, Ltd. as a polycarbonate diol, 10 sebacic acids 0.1 part and 0.025 part of dibutyltin oxide were added and the temperature was raised to 180 ° C. with stirring in the presence of toluene as a reaction water discharge solvent. After a while, water outflow separation was observed. By continuing the reaction for about 24 hours, a polyester polymer solution having a weight average molecular weight of 60,000 was obtained.
[0110]
To this polyester polymer solution, 30 parts of terpene phenol resin having a softening point of 115 ° C. and 2 parts of hexamethylene diisocyanate adduct of trimethylolpropane are added and mixed per 100 parts of the solid content. Thus, a hot adhesive composition solution was prepared. Next, this hot pressure-sensitive adhesive composition solution was applied to one side of a 38 μm thick polyester film so that the thickness after drying was 50 μm, and dried at 120 ° C. for 2 minutes. An adhesive tape for measurement was prepared. In addition, an adhesive tape for measuring shearing adhesive strength and impact resistance was prepared on one side of a polyester film that had been subjected to a release treatment in the same manner as described above.
[0111]
Example 5-2
Hot adhesive composition in the same manner as in Example 5-1, except that 20 parts of rosin phenol resin having a softening point of 145 ° C. was used instead of 30 parts of terpene phenol resin having a softening point of 115 ° C. A pressure sensitive adhesive tape for measuring holding force, shearing adhesive strength and impact resistance was prepared using this solution.
[0112]
Example 5-3
Hot adhesive composition in the same manner as in Example 5-1, except that 50 parts of coumarone-indene resin having a softening point of 120 ° C was used instead of 30 parts of terpene phenol resin having a softening point of 115 ° C. A pressure sensitive adhesive tape for measuring holding force, shearing adhesive strength and impact resistance was prepared using this solution.
[0113]
Reference Example 5-1
To the polyester polymer solution obtained in Example 5-1, 2 parts of trimethylolpropane tolylene diisocyanate adduct per 100 parts of the solid content was added and mixed, and the adhesive composition was heated. A solution of was prepared. Next, using this hot adhesive composition solution, an adhesive tape for measuring holding force, shearing adhesive force and impact resistance was prepared in the same manner as in Example 5-1.
[0114]
Reference Example 5-2
In the same manner as in Example 5-1, except that 30 parts of terpene phenol resin having a softening point of 50 ° C. was used instead of 30 parts of terpene phenol resin having a softening point of 115 ° C., an adhesive composition during heating was used. A pressure sensitive adhesive tape for measuring holding force, shearing adhesive strength and impact resistance was prepared using this solution.
[0115]
Comparative Example 5-1
In a reaction vessel equipped with a cooling pipe, a nitrogen introduction pipe, a thermometer and a stirrer, 50 parts of ethyl acetate and 50 parts of toluene are used as solvents, 50 parts of 2-ethylhexyl acrylate, 45 parts of n-butyl acrylate, 4 parts of acrylic acid .9 parts, 0.1 part of 2-hydroxyethyl acrylate and 0.1 part of 2,2′-azobisisobutyronitrile were added and polymerized in a nitrogen gas stream to give a weight average molecular weight of 700,000. An acrylic polymer solution was obtained.
[0116]
To this acrylic polymer solution, add 100 parts of terpene phenol resin with a softening point of 115 ° C. and 2 parts of hexamethylene diisocyanate adduct of trimethylolpropane per 100 parts of the solid content. Thus, a hot adhesive composition solution was prepared. Next, using this solution, an adhesive tape for measuring holding force, shearing adhesive force and impact resistance was prepared in the same manner as in Example 5-1.
[0117]
For each of the adhesive tapes prepared in Examples 5- (1 to 3), Reference Example 5- (1,2) and Comparative Example 5-1, the holding force, shearing adhesive force and impact resistance are as follows. It measured by the method of. These results were as shown in Table 6 below.
[0118]
<Retention force>
Adhesive tape with a width of 10mm is 120 ° C and 5Kg / cm with an adhesive area of 10mm x 20mm to a phenolic resin plate.² , Pasted for 1 minute, left for 20 minutes at 80 ° C after 20 minutes, and then dropped the phenolic resin plate, applied a uniform load of 500g to the free end of the adhesive tape, The falling time (minutes) of the adhesive tape was measured.
[0119]
<Shear adhesive strength>
A 10 mm x 10 mm adhesive tape was bonded between a 0.5 mm x 20 mm x 100 mm aluminum plate and a 2.0 mm x 20 mm x 100 mm PC plate, 120 ° C, 5 kg / cm.² After bonding for 2 minutes and leaving it to stand for 2 hours, the force required for shearing was measured under the conditions of normal temperature (23 ° C., 65% RH) and high temperature (80 ° C.) at a tensile speed of 10 mm / min. Each was measured.
[0120]
<Impact resistance>
A 10 mm x 10 mm adhesive tape is bonded between a 2 mm x 60 mm x 60 mm PC board and a 0.5 mm x 50 mm x 50 mm SUS304 board, 120 ° C, 5 kg / cm² , Adhered for 1 minute, allowed to stand for 2 hours, then dropped onto a concrete from a height of 80 cm at 0 ° C., and the number of times required for breaking was measured.
[0121]
Table 6

[0122]
From Table 6 above, each of the adhesive tapes of Examples 5- (1 to 3) satisfies the retention strength (creep resistance) at high temperature (80 ° C.) and the shear adhesive strength at normal temperature and high temperature. In addition, it is clear that it has excellent impact resistance at low temperatures (0 ° C.).
[0123]
Example 6-1
A four-neck separable flask was equipped with a stirrer, thermometer and water separation tube, and polycarbonate diol ("PLACCEL CD210PL" manufactured by Daicel Chemical Industries, Ltd., hydroxyl value: 115.0 KOHmg / g) 200 0.0 g (hydroxyl group: 0.41 equivalent), succinic anhydride 20.51 g (acid group: 0.41 equivalent), 102 mg of DBTO as a catalyst were charged, and stirring was performed in the presence of a small amount of toluene as a reaction water discharge solvent. While starting, the temperature was raised to 180 ° C. and kept at this temperature. After a while, water outflow separation was observed, and the reaction started to proceed. The reaction was continued for about 27 hours to obtain a polyester having a weight average molecular weight of 56,000.
[0124]
This polyester was diluted with toluene to a solid concentration of 50% by weight. To 100 parts (solid content) of this polyester, 1.0 part (solid content HL, manufactured by Nippon Polyurethane Co., Ltd.) of hexamethylene diisocyanate adduct of trimethylolpropane as a crosslinking agent (solid content). ) To give a pressure-sensitive adhesive composition. This pressure-sensitive adhesive composition was applied onto a PET film having a thickness of 38 μm by an applicator and dried at 130 ° C. for 3 minutes to form a pressure-sensitive adhesive layer having a thickness of 50 μm. Further, an adhesive sheet was prepared by pasting a polyethylene film having a thickness of 60 μm to the adhesive surface.
[0125]
Example 6-2
A four-necked separable flask was equipped with a stirrer, thermometer and water separation tube, and polycarbonate diol ("PLACCEL CD210PL" manufactured by Daicel Chemical Industries, hydroxyl value: 115.0 KOHmg / g) 250. 0 g (hydroxyl group: 0.51 equivalent), 51.8 g of sebacic acid (acid group: 0.51 equivalent), 127 mg of DBTO as a catalyst were charged, and stirring was started in the presence of a small amount of toluene as a reaction water discharge solvent. The temperature was raised to 180 ° C. and kept at this temperature. After a while, water outflow separation was observed, and the reaction started to proceed. The reaction was continued for about 30 hours to obtain a polyester having a weight average molecular weight of 60,000.
[0126]
This polyester was diluted with toluene to a solid concentration of 50% by weight. To 100 parts (solid content) of this polyester, 1.5 parts (solid state L) of trimethylolpropane tolylene diisocyanate adduct [“Colonate L” manufactured by Nippon Polyurethane Co., Ltd.] was used as a crosslinking agent. Min) was added to obtain an adhesive composition. This pressure-sensitive adhesive composition was applied onto a PET film having a thickness of 38 μm by an applicator and dried at 130 ° C. for 5 minutes to form a pressure-sensitive adhesive layer having a thickness of 50 μm. Furthermore, a 40 μm thick polypropylene film was bonded to the adhesive surface to prepare an adhesive sheet.
[0127]
Example 6-3
A four-neck separable flask was equipped with a stirrer, thermometer, and water separation tube, and polycarbonate diol ("PLACCEL CD220PL" manufactured by Daicel Chemical Industries, Ltd., hydroxyl value: 56.1 KOHmg / g) 250 0.0 g (hydroxyl group: 0.25 equivalent), 26.8 g of sebacic acid (acid group: 0.26 equivalent), 62 mg of DBTO as a catalyst were charged, and stirring was started in the presence of a small amount of toluene as a reaction water discharge solvent. While raising the temperature to 180 ° C., the temperature was maintained. After a while, water outflow separation was observed, and the reaction started to proceed. The reaction was continued for about 31 hours to obtain a polyester having a weight average molecular weight of 74,000.
[0128]
This polyester was diluted with toluene to a solid concentration of 50% by weight. For 100 parts (solid content) of this polyester, 1.5 parts (solid content HL) of hexamethylene diisocyanate adduct of trimethylolpropane (Nippon Polyurethane Co., Ltd.) as a cross-linking agent. ) To give a pressure-sensitive adhesive composition. This pressure-sensitive adhesive composition was applied onto a PET film having a thickness of 38 μm by an applicator and dried at 130 ° C. for 5 minutes to form a pressure-sensitive adhesive layer having a thickness of 50 μm. Further, an adhesive sheet was prepared by bonding a polyethylene / polypropylene blend film having a thickness of 40 μm to the adhesive surface.
[0129]
Example 6-4
The polyester of Example 6-3 was diluted with toluene to a solid concentration of 50% by weight. To 100 parts (solid content) of this polyester, 2.0 parts (solid content HL, manufactured by Nippon Polyurethane Co., Ltd.) of hexamethylene diisocyanate adduct of trimethylolpropane as a crosslinking agent (solid content). ) To give a pressure-sensitive adhesive composition. This pressure-sensitive adhesive composition was applied on a polyethylene film having a thickness of 60 μm by an applicator and dried at 80 ° C. for 10 minutes to form a pressure-sensitive adhesive layer having a thickness of 50 μm. Further, a polyethylene film having a thickness of 60 μm was bonded to the pressure-sensitive adhesive surface to produce a substrateless double-sided pressure-sensitive adhesive sheet.
[0130]
Example 6-5
A four-neck separable flask was equipped with a stirrer, thermometer, and water separation tube, and polycarbonate diol ("PLACCEL CD220PL" manufactured by Daicel Chemical Industries, Ltd., hydroxyl value: 56.1 KOHmg / g) 250 0.0 g (hydroxyl group: 0.25 equivalent), 25.0 g of sebacic acid (acid group: 0.25 equivalent), 70 mg of titanium tetraisopropoxide as a catalyst, and in the presence of a small amount of toluene as a reaction water discharge solvent While starting stirring, the temperature was raised to 180 ° C. and kept at this temperature. After a while, water outflow separation was observed, and the reaction started to proceed. The reaction was continued for about 24 hours to obtain a polyester having a weight average molecular weight of 59,000.
[0131]
This polyester was diluted with toluene to a solid concentration of 50% by weight. For 100 parts (solid content) of this polyester, 1.5 parts (solid content HL) of hexamethylene diisocyanate adduct of trimethylolpropane (Nippon Polyurethane Co., Ltd.) as a cross-linking agent. ) To give a pressure-sensitive adhesive composition. This pressure-sensitive adhesive composition was applied onto a PET film having a thickness of 38 μm by an applicator and dried at 130 ° C. for 5 minutes to form a pressure-sensitive adhesive layer having a thickness of 50 μm. Further, an adhesive sheet was prepared by pasting a polyethylene film having a thickness of 60 μm to the adhesive surface.
[0132]
Example 6-6
A four-necked separable flask was equipped with a stirrer, thermometer and water separation tube, and polycarbonate diol ("PLACCEL CD220PL" manufactured by Daicel Chemical Industries, Ltd., hydroxyl value: 56.1 KOHmg / g) 155 .4 g and polycaprolactone diol ["PLACCEL 220PL" manufactured by Daicel Chemical Industries, Ltd., hydroxyl value: 55.9 KOHmg / g] 84.1 g (hydroxyl group total: 0.24 equivalent), succinic anhydride 12.1 g (Acid group: 0.24 equivalent), 59 mg of DBTO as a catalyst was charged, and in the presence of a small amount of toluene as a reaction water discharge solvent, the temperature was raised to 180 ° C. while stirring was started, and kept at this temperature. After a while, water outflow separation was observed, and the reaction started to proceed. The reaction was continued for about 20 hours to obtain a polyester having a weight average molecular weight of 37,000.
[0133]
This polyester was diluted with toluene to a solid concentration of 50% by weight. To 100 parts (solid content) of this polyester, 3.0 parts (solid content HL) manufactured by Nippon Polyurethane Co., Ltd., a hexamethylene diisocyanate adduct of trimethylolpropane as a crosslinking agent. ) To give a pressure-sensitive adhesive composition. This pressure-sensitive adhesive composition was applied onto a PET film having a thickness of 38 μm by an applicator and dried at 130 ° C. for 5 minutes to form a pressure-sensitive adhesive layer having a thickness of 50 μm. Further, an adhesive sheet was prepared by pasting a polyethylene film having a thickness of 60 μm to the adhesive surface.
[0134]
Example 6-7
A four-necked separable flask was equipped with a stirrer, thermometer and water separation tube, and polycarbonate diol ("PLACCEL CD220PL" manufactured by Daicel Chemical Industries, Ltd., hydroxyl value: 56.1 KOHmg / g) 218 .1 g and octanediol 24.2 g (total hydroxyl group: 0.55 equivalent), 27.9 g of succinic anhydride (acid group: 0.56 equivalent), 60 mg of DBTO as a catalyst, and a small amount as a reaction water discharge solvent In the presence of toluene, the temperature was raised to 180 ° C. while starting stirring, and this temperature was maintained. After a while, water outflow separation was observed, and the reaction started to proceed. The reaction was continued for about 22 hours to obtain a polyester having a weight average molecular weight of 24,000.
[0135]
This polyester was diluted with toluene to a solid concentration of 50% by weight. To 100 parts (solid content) of this polyester, 3.0 parts (solid content HL) manufactured by Nippon Polyurethane Co., Ltd., a hexamethylene diisocyanate adduct of trimethylolpropane as a crosslinking agent. ) To give a pressure-sensitive adhesive composition. This pressure-sensitive adhesive composition was applied onto a PET film having a thickness of 38 μm by an applicator and dried at 130 ° C. for 5 minutes to form a pressure-sensitive adhesive layer having a thickness of 50 μm. Further, an adhesive sheet was prepared by pasting a polyethylene film having a thickness of 60 μm to the adhesive surface.
[0136]
Comparative Example 6-1
Using a monomer mixture of 92 parts of butyl acrylate and 8 parts of acrylic acid, and adding 150 parts of toluene and 0.1 part of azobisisobutyronitrile to this monomer mixture, Solution polymerization was performed at 60 ° C. for about 7 hours to obtain a polymer solution. To 100 parts (solid content) of this polymer, 2.0 parts (solid content L) of trimethylol propane tolylene diisocyanate adduct [“Coronate L” manufactured by Nippon Polyurethane Co., Ltd.] was used as a crosslinking agent. ) To give a pressure-sensitive adhesive composition. This pressure-sensitive adhesive composition was applied onto a PET film having a thickness of 38 μm by an applicator and dried at 120 ° C. for 5 minutes to form a pressure-sensitive adhesive layer having a thickness of 50 μm. Further, an adhesive sheet was prepared by bonding a polyethylene / polypropylene blend film having a thickness of 40 μm to the adhesive surface.
[0137]
Comparative Example 6-2
100 parts of natural rubber, 100 parts of aliphatic petroleum resin (softening point 100 ° C.), 20 parts of softening agent (polybutene) are dissolved in 150 parts of toluene, and a tolylene diisocyanate adduct of trimethylolpropane as a crosslinking agent [ 1.5 parts (solid content) of “Coronate L” manufactured by Nippon Polyurethane Co., Ltd. was added to obtain an adhesive composition. This pressure-sensitive adhesive composition was applied onto a PET film having a thickness of 38 μm by an applicator and dried at 100 ° C. for 5 minutes to form a pressure-sensitive adhesive layer having a thickness of 50 μm. Further, an adhesive sheet was prepared by pasting a polyethylene film having a thickness of 60 μm to the adhesive surface.
[0138]
About each adhesive sheet of said Example 6- (1-7) and Comparative Example 6- (1,2), the peeling force and adhesive force of a peeling liner were measured with the following method. The results were as shown in Table 7 below.
[0139]
<Measurement of peel force>
At an atmospheric temperature of 23 ° C., the release liner was peeled off from the adhesive sheet with an Instron type tensile tester at a peeling speed of 300 mm / min, and the peeling force was measured at a peeling angle of 180 degrees.
[0140]
<Measurement of adhesive strength>
The release liner was peeled off from the adhesive sheet and attached to an aluminum plate, and the 180 ° peel adhesive strength was measured under the conditions of an atmospheric temperature of 23 ° C., a sticking time of 30 minutes, and a peel rate of 300 mm / min. In addition, since Example 6-4 did not have a base material, a PET film having a thickness of 38 μm was lined up and measured.
[0141]
Table 7

[0142]
As is clear from the results in Table 7 above, each of the adhesive sheets of Examples 6- (1-7) of the present invention uses a release liner that has not been subjected to a silicon treatment. Nevertheless, it can be seen that it exhibits a small peeling force that does not interfere with the peeling operation and has a large adhesive force that is practically desired.
[0143]
【The invention's effect】
As described above, in the present invention, while having high elasticity and tack-free, it has high adhesive strength, can achieve both adhesion workability and adhesiveness, has excellent heat resistance, and retains and fixes articles. It is possible to provide an excellent pressure-sensitive adhesive composition and its pressure-sensitive adhesive sheet. In particular, the above-mentioned pressure-sensitive adhesive composition with excellent properties such as heat resistance and durability can be obtained by using a polymer having a polycarbonate structure as a base polymer and crosslinking it with a crosslinking agent. Products and their adhesive sheets can be provided, and further development in various fields can be achieved as an adhesive product with a new structure.
[0144]
  In the present invention,,By using an acrylic polymer with a glass transition temperature of -10 ° C or less together with a polymer having a polycarbonate structure, it exhibits extremely good adhesion properties to various adherends, as well as creep properties and long-term durability. An adhesive composition having excellent properties and an adhesive sheet thereof can be provided. Similarly, by using a resin having a softening point of 80 ° C. or higher together with the above-mentioned polymer, a pressure-sensitive adhesive composition satisfying creep resistance and adhesiveness in a high temperature range and excellent in impact resistance at low temperatures. And its adhesive sheets.
[0145]
Furthermore, in the present invention, the silicone treatment made of polyethylene film, polypropylene film or the like is not applied to the layer made of the pressure-sensitive adhesive composition having each of the above constitutions using a polymer having a polycarbonate structure. By using a release liner, it is possible to provide an adhesive sheet that has a good release property and does not contain silicone, and exhibits a large adhesive force. It can be used very advantageously as a sticky sheet suitable for the use of the present invention, in particular, the use of a computer device or the like where the inclusion of silicon is likely to be a problem.
[0146]
In the present invention, a layer made of the pressure-sensitive adhesive composition having the above-described configuration using a polymer having a polycarbonate structure is provided on one side of the base material, and at least the back side of the base material is made of polyethylene or By constituting with polyolefin such as polypropylene, it is possible to provide an adhesive sheet that can be wound into a roll without interposing a release liner. As an adhesive sheet that does not need to be peeled off with a silicon compound and does not need to be peeled off with a silicon compound, it is used as an adhesive sheet that does not substantially contain a silicon compound. Therefore, it can be advantageously used as an adhesive sheet suitable for use in a computer device or the like, which tends to cause problems.

Claims (9)

The following formula:
-(O-R-O-C) n-
‖
O

(In the formula, R is a linear or branched hydrocarbon group having 2 to 20 carbon atoms)

As a polymer having a polycarbonate structure having a repeating unit represented by formula (1), a pressure-sensitive adhesive composition containing a polyester having a weight average molecular weight of 10,000 or more is crosslinked, and the solvent insoluble content of the polymer in this layer is 20 to An adhesive sheet characterized by being 65% by weight .   The polyester having a weight average molecular weight of 10,000 or more is a dicarboxylic acid component essentially comprising a diol component essentially comprising a polycarbonate diol and a dicarboxylic acid having a molecular skeleton of an aliphatic or alicyclic hydrocarbon group having 2 to 20 carbon atoms. The pressure-sensitive adhesive sheet according to claim 1, which is a polyester having a weight average molecular weight of 10,000 or more synthesized from the above.   The pressure-sensitive adhesive composition according to claim 1 or 2, comprising a polymer having a polycarbonate structure and an acrylic polymer having a glass transition temperature of -10 ° C or lower at a ratio of 10 to 90% by weight in the total amount with the polymer. Adhesive sheets.   The pressure-sensitive adhesive composition according to claim 1 or 2, wherein the pressure-sensitive adhesive composition contains, together with a polymer having a polycarbonate structure, a resin having a softening point of 80 ° C or higher at a ratio of 10 to 50% by weight in the total amount with the polymer. Pressure-sensitive adhesive sheet according to any one of claims 1 to 4 having a layer on one side or pressure-sensitive adhesive composition on both sides of the substrate is formed by crosslinking treatment. The pressure-sensitive adhesive sheet according to any one of claims 1 to 5, wherein a release liner not subjected to silicone treatment is bonded to the pressure-sensitive adhesive surface. The release liner not subjected to silicone treatment is a polyolefin film made of polyethylene, polypropylene, ethylene-propylene copolymer or a mixture thereof, or a film whose surface is processed with the same polyolefin as described above. The pressure-sensitive adhesive sheet according to claim 6 , wherein the force is 200 g / 50 mm width or less. Claims have a layer formed by crosslinking the pressure-sensitive adhesive composition on one side of the base material, and the back side of the base material is not silicone-treated, and is wound into a roll without interposing a release liner. 1-4 . The adhesive sheets in any one of 1-4 . It has a layer formed by crosslinking the pressure-sensitive adhesive composition on one side of the base material, and at least the back side of the base material is made of polyethylene, polypropylene, an ethylene-propylene copolymer or a mixture of these and peeled. The pressure-sensitive adhesive sheet according to any one of claims 1 to 4 , wherein the pressure-sensitive adhesive sheet is wound into a roll without interposing a liner.