JP3755364B2 - Adhesive sheet or adhesive tape - Google Patents

Description

〔式中、Ｒはメチル基または水素原子、ｎは１〜２３の整数を表す。〕
【００２４】
（ポリ）アルキレングリコールジ（メタ）アクリレートの存在下で上記共重合体を製造すると、粘着剤に親水性を付与できると同時に分子量を上げることができるので、再分散後の粒子が硬くなり、リサイクル工程で残存した粒子が水中で粘着性を発現しないため、リサイクルに適した粘着剤を作ることができる。そして、これらの化合物は、粘着剤の親水性、水再分散性、粘着性能のバランスを考慮して適宣使用できるが、中でも特にポリエチレングリコールジメタクリレートは、親水性、水再分散性に優れた共重合体が得られるのでより好ましい。
【００２５】
なお、（ポリ）アルキレングリコールジ（メタ）アクリレートは、全モノマー混合物に対して０．１〜５質量％の範囲で添加させる必要がある。因みに、０．１質量％未満では、粘着剤の水再分散性が不十分となる。一方、５質量％を越えると、重合時に粘着剤が凝集し易くなる。
【００２６】
（ポリ）アルキレングリコールモノ（メタ）アクリレートとしては、下記一般式（２）に表される化合物で、例えばエチレングリコールモノ（メタ）アクリレート、ジエチレングリコールモノ（メタ）アクリレート、トリエチレングリコールモノ（メタ）アクリレート、テトラエチレングリコールモノ（メタ）アクリレート、ポリエチレングリコールモノ（メタ）アクリレート、ポリプロピレングリコールモノ（メタ）アクリレート等が挙げられる。
【００２７】
【化２】

〔式中、Ｒはメチル基または水素原子、ｎは１〜２３の整数を表す。〕
【００２８】
（ポリ）アルキレングリコールモノ（メタ）アクリレートの存在下で上記共重合体を製造すると、粘着剤に親水性を付与できると同時に、粘着剤を可塑化させることができるので、水再分散性と粘着性能のバランスのとれたリサイクルに適した粘着剤を作ることができる。
【００２９】
なお、（ポリ）アルキレングリコールモノ（メタ）アクリレートは、全モノマー混合物に対して０．１〜５質量％の範囲で添加させる必要がある。因みに、０．１質量％未満では、粘着剤の水再分散性が不十分となる。一方、５質量％を越えると、粘着剤の凝集力が低下する様になる。また、（ポリ）アルキレングリコールジ（メタ）アクリレートまたは（ポリ）アルキレングリコールモノ（メタ）アクリレートのアルキレングリコールの付加モル数が２３を越えると、再分散後の粒子があまり硬くならず、リサイクル工程で残存した粒子が水中で粘着性を発現してしまうので、紙の再生時の紙層形成または品質に悪影響を及ぼす可能性がある。
【００３０】
（ポリ）エチレングリコールおよび／または（ポリ）プロピレングリコールとしては、下記一般式（３）に表される化合物である。
【００３１】
【化３】

〔式中、Ｒはメチル基または水素原子、ｎは１〜５００の整数を表す。〕
【００３２】
（ポリ）エチレングリコールおよび／または（ポリ）プロピレングリコールの存在下で上記共重合体を製造すると、粘着剤に親水性を付与できるので、親水性、皮膜膨潤性に優れた共重合体が得られ、水再分散性のよいリサイクルに適した粘着剤を作ることができる。
【００３３】
なお、（ポリ）エチレングリコールおよび／または（ポリ）プロピレングリコールは、全モノマー混合物に対して０．１〜１５質量％の範囲、より好ましくは０．３〜１０質量％で添加させる必要がある。因みに、０．１質量％未満では、粘着剤の水再分散性が不十分となる。一方、１５質量％を越えると、粘度が高くなりやすく、粘着剤の取り扱い性が低下する。
【００３４】
アルカノールアミンとしては、モノエタノールアミン、ジエタノールアミン、トリエタノールアミン、プロパノールアミン、β−プロパノールアミン、トリプロパノールアミン、イソプロパノールアミン、トリイソプロパノールアミン、２−アミノイソヘキシルアルコール、Ｎ−メチルジエタノールアミン、Ｎ，Ｎ−ジブチルエタノールアミン等が挙げられる。これらのアルカノールアミンは、該共重合体中のカルボキシル基の５０〜１２０モル％に相当するよう添加する必要がある。因みに、５０モル％未満では、粘着剤皮膜の粘着性および水再分散性が不足し、１２０モル％を越えるとでは、保持力が不十分となり、また経時的に粘着剤の劣化や変色が生じやすくなる。
【００３５】
なお、これらのアルカノールアミンの中でも、粘着シートあるいは粘着テープ製造時の乾燥工程での揮散や経時後の品質変化などを防止するためには、沸点が１００℃以上、より好ましくは１７０℃以上のアルカノールアミンを使用することが望ましい。
【００３６】
ここで本発明の粘着剤に対する上記各モノマー、共重合時に添加する（ポリ）アルキレングリコールジ（メタ）アクリレート、（ポリ）アルキレングリコールモノ（メタ）アクリレート、ポリエチレングリコールおよび／またはポリプロピレングリコールの少なくとも１種および粘着剤共重合体に対して添加するアルカノールアミンの役割について簡単に説明すると、粘着剤の水再分散性を付与する成分としては、（ｂ）エチレン性不飽和カルボン酸含有モノマーと（ｃ）メタクリル酸メチルが重要であり、粘着剤の粘着性を付与する成分としては、（ａ）炭素数４〜１８のアルキル基を有する（メタ）アクリル酸アルキルエステルモノマーと、（ｂ）エチレン性不飽和カルボン酸含有モノマーと、（ｃ）メタクリル酸メチルが重要である。また粘着剤の親水性と付与しさらに粘着性を整える成分として、（ｄ）上記（ａ）、（ｂ）、（ｃ）と共重合可能な他のモノマーが重要である。さらに、これら粘着剤組成混合物を（ポリ）アルキレングリコールジ（メタ）アクリレート、（ポリ）アルキレングリコールモノ（メタ）アクリレート、ポリエチレングリコールおよび／またはポリプロピレングリコールの少なくともいずれか１種の存在下で共重合すると、粘着剤に親水性を付与できると同時に分子量を上げることができるので、再分散後の粒子が硬くなり、リサイクル工程で残存した粒子が水中で粘着性を発現しない。また、これら共重合体の粘着性および水再分散性発現のために行う中和反応において、アルカノールアミンを使用すると該共重合体の可塑化と水再分散性の経時劣化を防止することができる。これら（ａ）、（ｂ）、（ｃ）、（ｄ）および（ポリ）アルキレングリコールジ（メタ）アクリレート、（ポリ）アルキレングリコールモノ（メタ）アクリレート、ポリエチレングリコールおよび／またはポリプロピレングリコールの少なくともいずれか１種とアルカノールアミンを必須成分としてバランス良く配合することにより、共重合体は接着力を損なうことなく、水に対して再分散性を有し、再分散後の粒子が水中で粘着性を有しない粘着剤となるものである。
【００３７】
さらに、上記粘着剤に対し、粘着剤の物性を整え、粘着剤の経時による変色および劣化を防止するために、親水性の可塑化物質を添加することもできる。親水性の可塑化物質としては、例えば、グリセリン、ソルビット、マンニット、ズルシット、イジット、エリトリット、アラビット、アドニット等の糖アルコール類、ポリエチレンオキシドもしくはポリプロピレンオキシドとグリセリン、キシリットトリオキシイソブタン、ソルビットなどの多価アルコールとの共重合体やポリエチレングリコール、ポリプロピレングリコール等のポリエーテルポリオールや、エチレンオキシドとプロピレンオキシドとの共重合体、ポリオキシエチレンアルキルエーテール、ポリオキシエチレンアルキルフェニルエーテル、ポリオキシエチレンポリオキシプロピレングリコール等のノニオン性の界面活性剤等が挙げられる。この物質は粘着性と、水再分散性を考慮して、添加量は、共重合体１００質量％に対して１０質量％以下、より好ましくは０．５〜１０質量％の範囲で使用することが望ましい。
【００３８】
なお、これら親水性の可塑化物質の中でも、特に、ノニオン系の界面活性剤が、接着性や保存性の良好な粘着剤を仕上げることができるので好ましい。
【００３９】
従って、本発明で使用する、水に対して再分散性が優れ、且つ良好な接着性能を有する粘着剤を得るためには、上記の（ａ）炭素数４〜１８のアルキル基を有する（メタ）アクリル酸アルキルエステルモノマー、（ｂ）エチレン性不飽和カルボン酸含有モノマー、（ｃ）メタクリル酸メチル、（ｄ）それらと共重合可能な他のモノマーの配合バランスとそれらを（ポリ）アルキレングリコールジ（メタ）アクリレート存在下で共重合し、アルカノールアミンで中和することが極めて重要である。
【００４０】
なお、上記の共重合体の製造方法については、特に限定されるものではなく、例えば、水、溶剤、連鎖移動剤、重合開始剤等の存在下で溶液重合する方法や、乳化剤、連鎖移動剤、重合開始剤、分散剤等の存在下の水系でエマルジョン重合する方法などの公知の方法で製造される。
【００４１】
重合の際に使用される重合開始剤としては、例えば過硫酸カリウム、過硫酸アンモニウム等の過硫酸塩、２，２’−アゾビスイソブチロニトリル、２，２’−アゾビス（２，４−ジメチルバレロニトリル）等のアゾ系化合物、過酸化水素、ベンゾイルパーオキサイド、ラウリルパーオキサイド等の過酸化物、過硫酸アンモニウムと亜硫酸ソーダ、酸性亜硫酸ソーダ等との組合せからなる、いわゆるレドックス系の重合開始剤等が挙げられる。重合開始剤の使用量は、通常重合に共するモノマー全量に対して、０．２〜２質量％、より好ましくは、０．３〜１質量％程度である。
【００４２】
共重合に際して添加する連鎖移動剤としては、オクチルメルカプタン、ノニルメルカプタン、デシルメルカプタン、ドデシルメルカプタン、Ｎ−ドデシルメルカプタン等のアルキルメルカプタン類、チオグリコール酸オクチル、チオグリコール酸ノニル、チオグリコール酸−２−エチルヘキシル、β−メルカプトプロピオン酸−２−エチルヘキシル等のチオグリコール酸エステル類、２，４−ジフェニル−４−メチル−１−ペンテン、１−メチル−４−イソプロピリデン−１−シクロヘキセン等を挙げることが出来る。特に、チオグリコール酸エステル類、２，４−ジフェニル−４−メチル−１−ペンテン、１−メチル−４−イソプロピリデン−１−シクロヘキセンを使用した場合には、得られる共重合体が低臭気となり好ましい。なお、連鎖移動剤の使用量は、重合させる全モノマーの０〜３質量％程度に調節される。また、メタノール、エタノール、イソプロピルアルコール等の有機溶剤も使用することができる。
【００４３】
重合時のモノマー濃度は、通常３０〜７０質量％、好ましくは４０〜６０質量％程度が適当である。また、重合反応は、通常６０〜１００℃の温度条件下で、２〜８時間かけて行われる。さらに、濡れ剤、レベリング剤、増粘剤、消泡剤、防腐剤等を適宣添加することができる。また、特に望むならば、粘着剤の性能、特にポリオレフィン系被着体に対する接着力、凝集力等の物性を向上させる目的で、エチレン−酢ビ共重合体、エチレン−酢酸ビニル−アクリル系共重合体を添加することもできる。
【００４４】
上記の方法で得られた共重合体は、その共重合体中のカルボキシル基の５０〜１２０モル％に相当するアルカノールアミンで中和する必要がある。中和処理を施すことにより、機械安定性を改良でき、また粘度調整を行うことができる。
【００４５】
また、共重合体中のカルボキシル基の中和には、アルカノールアミンのほかに、水酸化カリウムや水酸化ナトリウム等のアルカリ金属の水酸化物、アンモニア等を併用することができるが、粘着シートおよび粘着テープに加工された後の経時での揮散による粘着性能の変化と水再分散性の劣化防止の点から、より好ましくは水酸化カリウム等のアルカリ金属の水酸化物が用いられる。
【００４６】
上記の共重合体のガラス転移温度は、−７０〜−１０℃の範囲のものであり、目的に応じて適宣選択される。因みに、共重合体のガラス転移温度が−７０℃未満になると、得られる皮膜の凝集力が不十分となり、逆に−１０℃を越えると、得られる共重合体の皮膜が硬くなりすぎて、実用性に乏しくなる傾向がある。
【００４７】
本発明は、この様な共重合体を粘着剤として用いることにより、古紙のリサイクル工程に混入可能な粘着シートまたは粘着テープが得られるものである。
【００４８】
次に粘着シートに使用する水またはアルカリ水溶液で離解可能な表面基材としては、上質紙、アート紙、コート紙、キャスト紙、クラフト紙、含浸紙、低サイズ紙、水溶紙、クラフト紙または上質紙等に、例えばカゼイン、デキストリン、澱粉、カルボキシメチルセルロース、メチルセルロース、エチルセルロース、ヒドロキシエチルセルロース、ポリビニルアルコール、スチレン−ブタジエン共重合体、メチルメタクリレート−ブタジエン共重合体、エチレン−塩化ビニル共重合体、エチレン−酢酸ビニル共重合体、アクリル酸エステル共重合体等の天然または合成樹脂および／または顔料とを主成分とした目止め層を設けた基材等の紙類や、ポリビニルアルコール、カルボキシメチルセルロース、メチルセルロース等の水溶性高分子より成形した水溶性フィルム、或いは、乳酸またはラクチドとグリコール酸、ヒドロキシ酪酸、ヒドロキシ吉草酸、ヒドロキシペンタン酸、ヒドロキシカプロン酸、ヒドロキシヘプタン酸等のヒドロキシカルボン酸との共重合やポリ乳酸等の乳酸系ポリマーより成形したアルカリ水溶液で容易に加水分解するフィルム等を使用することができる。
【００４９】
次に粘着シートの剥離シートまたは粘着テープの基材に使用するダイレクトタイプ基材とは、ポリエチレン等をラミネートしていない剥離紙基材のことであって、クレーコート紙、グラシン紙やクラフト紙または上質紙等に、例えばカゼイン、デキストリン、澱粉、カルボキシメチルセルロース、メチルセルロース、エチルセルロース、ヒドロキシエチルセルロース、ポリビニルアルコール、スチレン−ブタジエン共重合体、メチルメタクリレート−ブタジエン共重合体、エチレン−塩化ビニル共重合体、エチレン−酢酸ビニル共重合体、アクリル酸エステル共重合体等の天然または合成樹脂および／または顔料とを主成分とした目止め層を設けた基材などを挙げることができる。
【００５０】
なお、粘着シートの表面基材や剥離シート、粘着テープの基材に使用する紙類は、その紙層ｐＨが６以下の紙を使用することが望ましい。これは、紙層ｐＨが６より高い領域では、粘着剤組成中の親水性成分、特にカルボキシル基を有する化合物が、紙中またはコート紙などの塗被層に含まれる炭酸カルシウム等の影響を受けやすく、粘着剤が劣化するためである。また、ここで言う紙層ｐＨとは、粘着シートの表面基材や剥離シートの場合は粘着剤や剥離剤を塗布した面の反対面を、粘着テープ基材の場合は粘着剤を有機溶剤で膨潤させて掻き取った面を、セロハンテープ等を使用して表層を剥がして原紙層を露にし、市販のｐＨによって変色する試験液（例えば、紙面測定用ｐＨ計、共立理化学研究所社製）を紙面に塗り、標準色と比色して求められるものである。
【００５１】
また、粘着シートの剥離シートまたは粘着テープの基材に使用するダイレクトタイプ基材において使用する樹脂および／または顔料を主成分とする目止め層としては特に限定するものではないが、例えばカゼイン、デキストリン、澱粉、カルボキシメチルセルロース、メチルセルロース、エチルセルロース、ヒドロキシエチルセルロース、ポリビニルアルコール、スチレン−ブタジエン共重合体、メチルメタクリレート−ブタジエン共重合体、エチレン−塩化ビニル共重合体、アクリル酸エステル共重合体等の天然または合成樹脂および／またはカオリン、炭酸カルシウム、クレー、タルク、焼成カオリン、デラミカオリン、二酸化チタン、水酸化アルミニウム、シリカ、ホワイトカーボン等の無機顔料、或いはポリスチレン樹脂微粒子、尿素−ホルマリン樹脂微粒子、微小中空粒子等の有機合成顔料等を用いることができる。
【００５２】
上記目止め層を設けた基材の他に、例えばアート紙、コート紙、キャスト塗被紙等のように紙の表面に顔料を主成分とした印刷用塗被層を設けた基材を用いても良い。もちろん必要であれば予め印刷を施した基材が適用できる。
【００５３】
なお、上記顔料塗被層を設ける場合には、顔料塗被液に、顔料以外に顔料同士および顔料と基材の表面とを固着させるために接着剤を使用する。かかる接着剤としては、例えばカゼイン、デキストリン、澱粉、カルボキシメチルセルロース、メチルセルロース、エチルセルロース、ヒドロキシエチルセルロース、ポリビニルアルコール、スチレン−ブタジエン共重合体、メチルメタクリレート−ブタジエン共重合体、エチレン−塩化ビニル共重合体、エチレン−酢酸ビニル共重合体、アクリル酸エステル共重合体等の、天然または合成の接着剤が、水溶液または水分散液（エマルジョン）の形で使用される。なお、顔料塗被液にはこれら顔料や接着剤の他に、その性質を阻害しない範囲で、消泡剤、分散剤、防腐剤、染料等の種々の助剤を必要に応じて、添加することもできる。
【００５４】
そして、かかる樹脂および／または顔料を主成分とする目止め層塗被液は、ブレードコーター、バーコーター、エアーナイフコーター、グラビアコーター、ロールコーター、ダイコーター、リップコーター等の通常の塗被装置で塗被される。この場合の塗被量は、固形分質量で２ｇ／ｍ²以上、好ましくは４〜３０ｇ／ｍ²の範囲で調節される。
【００５５】
次に本発明の粘着シート用剥離シートおよび粘着テープ用基材の一面に形成する剥離剤層に用いる剥離剤としては、特に限定はなく、一般に使用される水分散型、溶剤型あるいは無溶剤型のシリコーン樹脂やフッ素樹脂等を乾燥質量で０．０５〜３ｇ／ｍ²程度塗被後、熱硬化、電離放射線硬化等によって剥離層を形成したものが使用される。中でも無溶剤型シリコーンは、剥離層形成時に有害な溶剤を使用することもなく、また水分散型に比べ、乾燥効率に優れるため、より好ましく使用される。
【００５６】
また、最近では、粘着ラベルの一形態として、省資源の観点から、剥離紙のないテープ状のものも開発されているが、この場合はアート紙やコート紙の如き印刷紙の印刷面に離型性被印刷層を設けてなる物で、この様な層を剥離剤層の代わりに使用しても構わない。
【００５７】
粘着シートの形成方法は、通常、剥離シートの剥離剤表面上に粘着剤を塗被、乾燥して粘着剤層を設け、次いで表面基材と貼り合わせて仕上げられるが、直接表面基材に粘着剤を塗被して粘着剤層を設けてもかまわない。
【００５８】
粘着テープの形成方法は、通常、剥離剤層や離型性被印刷層を設けた基材の裏面に直接粘着剤を塗被、乾燥して粘着剤層を設けて仕上げられるが、一旦工程用剥離紙の剥離剤層側に粘着剤を塗被、乾燥させ、表面に剥離剤層や離型性被印刷層を設けたテープ用基材の裏面を貼り合わせて粘着シートに仕上げた後に剥離シートを除きながら粘着テープに仕上げても良い。
【００５９】
粘着シートまたは粘着テープを形成する場合、粘着剤は分子量の調節、水による希釈、或いは増粘等の手段によって、通常０．０１〜９パスカル秒程度の粘度に調節して剥離シートに塗被される。この場合の塗被装置としては、例えばリバースロールコーター、ナイフコーター、エアーナイフコーター、バーまたはロッドコーター、スロットダイコーター、リップコーター、リバースグラビアコーター等が使用される。本発明の粘着シートおよび粘着テープにおいて、塗被装置として特に限定はなく、これらの一般の方法で製造される。粘着剤の塗被量は、その目的により様々であるが、３ｇ／ｍ²以上、より好ましくは５〜５０ｇ／ｍ²程度の範囲で調節される。因みに、３ｇ／ｍ²未満では、得られる粘着シートまたは粘着テープの接着性能が不十分となり、一方５０ｇ／ｍ²を越えると粘着シートまたは粘着テープの製造時に粘着剤がはみ出したり、剥離の際に凝集破壊の原因となる恐れがある。
【００６０】
【実施例】
以下、実施例をあげて本発明をより具体的に説明するが、勿論本発明はこれらに限定されるものではない。また例中の部、割合、塗被量等は特に断わらないかぎり、全て固形分または有効成分質量で示すものである。
【００６１】
実施例１
（粘着剤の製造）
まず乳化モノマー混合液として、
アクリル酸−２−エチルヘキシル：２５０部
アクリル酸：３５部
（メタ）アクリル酸メチル：２０部
アクリル酸メトキシエチル：７５部
酢酸ビニル：２０部
アニオン系乳化剤（商品名：エマールＮＣ−３５／花王社製）：６部
イオン交換水：１５０部
を混合し、乳化剤とイオン交換水を除く（以下同じ）全モノマー混合物に対してポリエチレングリコールジメタクリレート（商品名：ＮＫエステルＡ−４Ｇ／新中村化学社製）を０．９質量％添加して、調製した。
【００６２】
次ぎに撹拌機、クーラー、滴下ロート、窒素吸入管、温度計を付帯したフラスコに、イオン交換水１５０部、過硫酸カリウム３部、オクチルメルカプタン３部を仕込み、窒素置換しながら８０℃に昇温した後、上記乳化モノマー混合液を１／６滴下した。反応率が９０％に達した時点で残りのモノマー混合液を３時間かけて滴下し重合を行った。滴下終了後、８０℃で３時間熟成して反応を完結させた。次にフラスコ内容物を４０℃に冷却し、トリエタノールアミンを共重合体中のカルボキシル基の５０モル％添加して中和反応を行い、反応終了後に強撹拌して本発明に使用する粘着剤を製造した。
【００６３】
（目止め層を設けた剥離紙基材の作成）
塗被液として、カオリン（商品名：ＨＴクレー／エンゲルハード社製）：５０部、アクリル酸エステル共重合体（商品名：リカボンドＥＴ−８４／中央理化社製）：５０部、潤滑剤（商品名：ノプコＣ−１０４／サンノプコ社製）：０．５部、消泡剤（商品名：ノプコ１４０７Ｋ／サンノプコ社製）：０．３部からなる組成物を、固形分濃度が５０％になるように混合調製して、市販の米坪６４ｇ／ｍ²の上質紙上に乾燥質量が５ｇ／ｍ²となるように塗被、乾燥して目止め層を設けた。次いで、スーパーキャレンダーにて平滑仕上げを行い、剥離紙用の基材を得た。
【００６４】
次に、かくして得られた剥離紙基材の目止め層上に溶剤型のシリコーン剥離剤（商品名：ＬＴＣ−３００Ｂ／東レ・ダウコーニング社製）：１００部、触媒（商品名ＳＲＸ−２１２／東レ・ダウコーニング社製）：０．８部を乾燥質量が１．０ｇ／ｍ²となるように塗被、熱硬化した。
【００６５】
（粘着シートの作製）
上記、剥離紙に、得られた粘着剤を乾燥質量で２５ｇ／ｍ²となるように塗被、乾燥させた後、市販の米坪６４ｇ／ｍ²の上質紙と貼り合わせて粘着シートを得た。
【００６６】
（目止め層を設けたテープ用基材の作成）
塗被液として、カオリン（商品名：ＫＣＳクレー／ＥＣＣ社製）：７０部、リン酸エステル化澱粉（商品名：ニールガムＡ−８５／松谷化学社製）：５部、ＳＢＲラテックス（商品名：Ｌ−１７９５／旭化成社製）：２５部、分散剤（商品名：アロンＡ−９／東亞合成化学工業社製）：０．２部から成る組成物を、固形分濃度が４０％となるように混合調製して市販の米坪７３ｇ／ｍ²のクラフト紙上に乾燥質量が１０ｇ／ｍ²となるように塗被、乾燥して目止め層を設けた。
【００６７】
次に、かくして得られたテープ用基材の目止め層上に溶剤型のシリコーン剥離剤（商品名：ＳＤ−７２２０／東レ・ダウコーニング社製）：１００部、触媒（商品名ＳＲＸ−２１２／東レ・ダウコーニング社製）：０．６部を乾燥質量が１．０ｇ／ｍ²となるように塗被、熱硬化した。
【００６８】
（粘着テープの作成）
上記剥離剤層を設けたテープ用基材の裏面に上記粘着剤を乾燥質量で４０ｇ／ｍ²となるように塗被、乾燥させた後、この粘着剤層と上記テープ用基材の剥離剤層面とを貼り合わせて本発明の粘着テープを作成した。
【００６９】
実施例２
（粘着剤の製造）
まず乳化モノマー混合液として、
アクリル酸−２−エチルヘキシル：３３０部
アクリル酸：６０部
（メタ）アクリル酸メチル：５部
酢酸ビニル：５
アニオン系乳化剤（商品名：エマールＮＣ−３５／花王社製）：６部
イオン交換水：１５０部
を混合し、全モノマー混合物に対してポリエチレングリコールジメタクリレート（商品名：ＮＫエステル９Ｇ／新中村化学社製）を１．８質量％、ポリプロピレングリコール（和光純薬工業社製／平均分子量１０００）を２．７質量％添加して、調製した。
次いで、実施例１と同様にして共重合体を製造し、トリエタノールアミンと１０％水酸化カリウム水溶液をそれぞれ共重合体中のカルボキシル基の５０モル％添加して中和反応を行った。
さらに、この粘着剤１００部に対し、ノニオン系の界面活性剤（商品名：エマルゲン８１０／花王社製）：４部を添加し、強撹拌して本発明に使用する粘着剤を製造した。
【００７０】
前記粘着剤を使用した以外は、実施例１と同様にして粘着シートを作製した。
【００７１】
前記粘着剤を使用した以外は、実施例１と同様にして粘着テープを作製した。
【００７２】
実施例３
（粘着剤の製造）
まず乳化モノマー混合液として、
アクリル酸−２−エチルヘキシル：２５０部
アクリル酸：２５部
（メタ）アクリル酸メチル：４０部
アクリル酸メトキシエチル：７５部
酢酸ビニル：１０部
アニオン系乳化剤（商品名：エマールＮＣ−３５／花王社製）：６部
イオン交換水：１５０部
を混合し、全モノマー混合物に対してポリエチレングリコールジメタクリレート（商品名：ＮＫエステル９Ｇ／新中村化学社製）を２．７質量％、ポリプロピレングリコール（和光純薬工業社製／平均分子量１０００）を４．０質量％添加して、調製した。
次いで、実施例２と同様にして粘着剤を製造した。
【００７３】
前記粘着剤を使用した以外は、実施例１と同様にして粘着シートを作製した。
【００７４】
前記粘着剤を使用した以外は、実施例１と同様にして粘着テープを作製した。
【００７５】
実施例４
（粘着剤の製造）
まず乳化モノマー混合液として、
アクリル酸−２−エチルヘキシル：１９０部
アクリル酸：３５部
（メタ）アクリル酸メチル：２０部
アクリル酸メトキシエチル：９０部
酢酸ビニル：２５部
アニオン系乳化剤（商品名：エマールＮＣ−３５／花王社製）：６部
イオン交換水：１５０部
を混合し、全モノマー混合物に対してポリエチレングリコールモノメタクリレート（商品名：ブレンマーＰＥ−２００／日本油脂社製）を２．７質量％添加して、調製した。
次いで、実施例１と同様にして共重合体を製造し、トリエタノールアミンを共重合体中のカルボキシル基の１００モル％添加して中和反応を行った。
さらに、この粘着剤１００部に対し、ノニオン系の界面活性剤（商品名：エマルゲン８１０／花王社製）：４部を添加し、強撹拌して本発明に使用する粘着剤を製造した。
【００７６】
前記粘着剤を使用した以外は、実施例１と同様にして粘着シートを作製した。
【００７７】
前記粘着剤を使用した以外は、実施例１と同様にして粘着テープを作製した。
【００７８】
実施例５
（粘着剤の製造）
乳化モノマー混合液として、実施例１と同じモノマー組成の混合液に対して、ポリエチレングリコール（和光純薬工業社製／平均分子量１０００）を０．９質量％添加して、調製した以外は、実施例１と同様にして粘着剤を製造した。
【００７９】
前記粘着剤を使用した以外は、実施例１と同様にして粘着シートを作製した。
【００８０】
前記粘着剤を使用した以外は、実施例１と同様にして粘着テープを作製した。
【００８１】
実施例６
（粘着剤の製造）
まず乳化モノマー混合液として、
アクリル酸−２−エチルヘキシル：２９０部
アクリル酸：３５部
（メタ）アクリル酸メチル：２０部
アクリル酸メトキシエチル：３５部
酢酸ビニル：２０部
アニオン系乳化剤（商品名：エマールＮＣ−３５／花王社製）：６部
イオン交換水：１５０部
を混合し、全モノマー混合物に対してポリエチレングリコールジメタクリレート（商品名：ＮＫエステル９Ｇ／新中村化学社製）を１．８質量％、ポリプロピレングリコール（和光純薬工業社製／平均分子量１０００）を４．０質量％添加して、調製した。
次いで、実施例２と同様にして粘着剤を製造した。
【００８２】
（表面基材および粘着テープ用基材の作成）
塗被液として、カオリン（商品名：ＵＷ−９０／ＥＭＣ社製）：７０部、重質炭酸カルシウム（商品名：ハイドロカーブＫ−６／備北粉化社製）：３０部、リン酸化エステル化澱粉（商品名：ニールガムＡ−５５Ｃ／アベベ社製）：１部、酸化澱粉（商品名：エースＡ／王子コーンスターチ社製）：８部、ＳＢＲラテックス（商品名：Ｔ−２２５７／日本合成ゴム社製）：８部、分散剤（商品名：アロンＡ−９／東亞合成化学工業社製）：０．１部からなる組成物を、固形分濃度６０％となるように混合調製して塗被組成物を得た。
かくして得た塗被組成物を市販の米坪６４ｇ／ｍ²の上質紙上に乾燥質量が２０ｇ／ｍ²となるように塗被、乾燥して顔料塗被層を設けた。次いで、スーパーキャレンダーにて光沢仕上げを行い、表面基材を仕上げた。
【００８３】
次に、かくして得られた基材の顔料塗被層上に無溶剤型のシリコーン剥離剤（商品名：ＬＴＣ−１０７３Ｌ／東レ・ダウコーニング社製）：１００部、触媒（商品名ＬＴＣ−１１００Ｍ／東レ・ダウコーニング社製）：１０部を乾燥質量が１．０ｇ／ｍ²となるように塗被、熱硬化し、粘着テープ用基材とした。
【００８４】
上記粘着剤と表面基材を使用し、実施例１と同様にして粘着シートを作製した。
【００８５】
上記粘着剤とテープ用基材を使用し、実施例１と同様にして粘着テープを作製した。
【００８６】
実施例７
表面基材および粘着テープ用基材として、下記に示す基材を用いた以外は実施例６と同様にして粘着シートおよび粘着テープを作成した。
【００８７】
（表面基材および粘着テープ用基材の作成）
塗被液として、カオリン（商品名：ＵＷ−９０／ＥＭＣ社製）：４５部、炭酸カルシウム（商品名：ブリリアントＳ−１５／白石工業社製）：５５部、ラテックス（商品名：Ｌ−１３９２／旭化成社製）：２１部、カゼイン（商品名：アラシッド／ニュージーランドカゼイン社製）：５．４３部、分散剤（商品名：ナンカリンＳ−１／燐化学社製）：０．０６７５部、消泡剤（商品名：ビスマーＦＸ−１０／日新化学社製）：０．３部、離型剤（商品名：ハイドリンＺ−８／中京油脂社製）０．８部、硫酸亜鉛：３部から成る組成物を、固形分濃度４７％となるように混合調製して、市販の米坪６４ｇ／ｍ²の上質紙上に乾燥質量が２５ｇ／ｍ²となるよう塗被、乾燥し、スーパーキャレンダーにて平滑仕上げを行い、リウェット法により、前記塗被層が湿潤状態にある間、この塗被層面を加熱金属ドラムに圧接し、キャスト仕上げを行い、基材を得た。
【００８８】
次に、かくして得られた基材の顔料塗被層上に無溶剤型のシリコーン剥離剤（商品名：ＬＴＣ−１０７３Ｌ／東レ・ダウコーニング社製）：１００部、触媒（商品名ＬＴＣ−１１００Ｍ／東レ・ダウコーニング社製）：１０部を乾燥質量が１．０ｇ／ｍ²となるように塗被、熱硬化し、粘着テープ用基材とした。
【００８９】
比較例１
（粘着剤の製造）
まず乳化モノマー混合液として、
アクリル酸−２−エチルヘキシル：２５０部
アクリル酸：３５部
（メタ）アクリル酸メチル：２０部
アクリル酸メトキシエチル：７５部
酢酸ビニル：２０
アニオン系乳化剤（商品名：エマールＮＣ−３５／花王社製）：６部
イオン交換水：１５０部
を混合し、調製した。
【００９０】
次いで、実施例１と同様に共重合体を製造し、トリエタノールアミンを共重合体中のカルボキシル基の５０モル％添加して中和反応を行い粘着剤を得た。
【００９１】
前記粘着剤を使用した以外は、実施例１と同様にして粘着シートを作製した。
【００９２】
前記粘着剤を使用した以外は、実施例１と同様にして粘着テープを作製した。
【００９３】
比較例２
（粘着剤の製造）
乳化モノマー混合液として、
アクリル酸−２−エチルヘキシル：２６０部
アクリル酸：１５部
（メタ）アクリル酸メチル：３０部
アクリル酸メトキシエチル：７５部
酢酸ビニル：２０部
アニオン系乳化剤（商品名：エマールＮＣ−３５／花王社製）：６部
イオン交換水：１５０部
を混合し、全モノマー混合物に対してポリエチレングリコールジメタクリレート（商品名：ＮＫエステル９Ｇ／新中村化学社製）を１．８質量％、ポリプロピレングリコール（和光純薬工業社製／平均分子量１０００）を２．７質量％添加して、調製した。
次いで、実施例２と同様にして粘着剤を製造した。
【００９４】
前記粘着剤を使用した以外は、実施例１と同様にして粘着シートを作製した。
【００９５】
前記粘着剤を使用した以外は、実施例１と同様にして粘着テープを作製した。
【００９６】
比較例３
（粘着剤の製造）
乳化モノマー混合液として、
アクリル酸−２−エチルヘキシル：３４５部
アクリル酸：５０部
（メタ）アクリル酸メチル：５部
アニオン系乳化剤（商品名：エマールＮＣ−３５／花王社製）：６部
イオン交換水：１５０部
を混合し、全モノマー混合物に対してポリエチレングリコールジメタクリレート（商品名：ＮＫエステル９Ｇ／新中村化学社製）を２．７質量％、ポリプロピレングリコール（和光純薬工業社製／平均分子量１０００）を４．０質量％添加して、調製した。
次いで、実施例４と同様にして粘着剤を製造した。
【００９７】
前記粘着剤を使用した以外は、実施例１と同様にして粘着シートを作製した。
【００９８】
前記粘着剤を使用した以外は、実施例１と同様にして粘着テープを作製した。
【００９９】
比較例４
（粘着剤の製造）
乳化モノマー混合液として、
アクリル酸−２−エチルヘキシル：１９５部
アクリル酸：２５部
（メタ）アクリル酸メチル：４５部
アクリル酸メトキシエチル：１１５部
酢酸ビニル：２０部
アニオン系乳化剤（商品名：エマールＮＣ−３５／花王社製）：６部
イオン交換水：１５０部
を混合し、全モノマー混合物に対してポリエチレングリコールモノメタクリレート（商品名：ブレンマーＰＥ−２００／日本油脂社製）を２．７質量％添加して、調製した。
次いで、実施例４と同様にして粘着剤を製造した。
【０１００】
前記粘着剤を使用した以外は、実施例１と同様にして粘着シートを作製した。
【０１０１】
前記粘着剤を使用した以外は、実施例１と同様にして粘着テープを作製した。
【０１０２】
比較例５
（粘着剤の製造）
乳化モノマー混合液として、実施例１と同じモノマー組成の混合液に対して、ポリエチレングリコールジメタクリレート（商品名：ＮＫエステル９Ｇ／新中村化学社製）を０．９質量％添加して、調製した。
次いで、実施例１と同様に共重合体を製造し、アンモニア水で中和反応を行い、反応終了後に強撹拌して本発明に使用する粘着剤を製造した。
【０１０３】
前記粘着剤を使用した以外は、実施例１と同様にして粘着シートを作製した。
【０１０４】
前記粘着剤を使用した以外は、実施例１と同様にして粘着テープを作製した。
【０１０５】
比較例６
（粘着剤の製造）
比較例５と同様に乳化モノマー混合液を調製し、次いで実施例１と同様にして共重合体を製造、次いで、トリエタノールアミンを共重合体中のカルボキシル基の１５０モル％添加して中和反応を行い、反応終了後に強撹拌して本発明に使用する粘着剤を製造した。
【０１０６】
前記粘着剤を使用した以外は、実施例１と同様にして粘着シートを作製した。
【０１０７】
前記粘着剤を使用した以外は、実施例１と同様にして粘着テープを作製した。
【０１０８】
比較例７
粘着剤として、水およびアルカリ水溶液に不溶なアクリル系粘着剤（商品名：ニカゾールＬ−１４５／日本カーバイド工業社製）を乾燥質量で２２ｇ／ｍ²となるように塗被、乾燥した以外は、実施例７と同様にして粘着シートを作成した。
【０１０９】
比較例８
粘着テープとして市販のポリエチレンラミネートクラフト紙粘着テープ（商品名：ＯＪＩクラフトテープ／王子化工社製）を用い、評価用試料とした。
【０１１０】
比較例９
剥離紙基材および粘着テープ用基材として、市販のポリエチレンラミネート紙を用いた以外は、実施例６と同様に粘着シートおよび粘着テープを作成した。
【０１１１】
比較例１０
表面基材として、市販のポリエチレンテレフタレートフィルム（東洋紡績社製）を用いた以外は、実施例１と同様にして粘着シートを作成した。
【０１１２】
比較例１１
（粘着剤の製造）
乳化モノマー混合液として、
アクリル酸−２−エチルヘキシル：３１０部
アクリル酸：６５部
（メタ）アクリル酸メチル：５部
酢酸ビニル２０
アニオン系乳化剤（商品名：エマールＮＣ−３５／花王社製）：６部
イオン交換水：１５０部
を混合し、全モノマー混合物に対してポリエチレングリコールジメタクリレート（商品名：ＮＫエステル９Ｇ／新中村化学社製）を１．８質量％、ポリプロピレングリコール（和光純薬工業社製／平均分子量１０００）を２．７質量％添加して、調製した。
次いで、実施例２と同様にして共重合体を製造し、トリエタノールアミンと１０％水酸化カリウム水溶液で共重合体中のカルボキシル基をそれぞれ５０モル％添加して中和反応を行い、反応終了後に強撹拌して本発明に使用する粘着剤を製造した。
【０１１３】
前記粘着剤を使用した以外は、実施例１と同様にして粘着シートを作製した。
【０１１４】
前記粘着剤を使用した以外は、実施例１と同様にして粘着テープを作製した。
【０１１５】
このようにして得られた粘着シートおよび粘着テープについて、下記の評価を行い、得られた結果を表１および表２に示した。
【０１１６】
（評価試験項目）
〔接着力〕ＪＩＳ−Ｚ−０２３７の常態粘着力の測定方法に準拠し、下記の二つの条件で保存した後の接着力をそれぞれ測定した。（単位：Ｎ／ｍ）
条件Ａ：粘着シートおよび粘着テープの製造後、温度２３±２℃、関係湿度６５±５％の雰囲気下に７日間保存した後、その接着力を測定した。
条件Ｂ：粘着シートおよび粘着テープの製造後、温度４０±２℃、関係湿度９０±５％の雰囲気下に７日間保存した後、その接着力を測定した。
【０１１７】
〔凝集力〕ＪＩＳ−Ｚ−０２３７の常態保持力の測定方法に準拠した方法で測定し、下記の評価基準で評価した。
粘着シートおよび粘着テープの製造後、温度２３±２℃、関係湿度６５±５％の雰囲気下に７日間保存した後、その接着力を測定した。
○：荷重重りが５分以降に落下した。
×：荷重重りが５分未満の間に落下した。
【０１１８】
〔粘着テープのボックスループ〕ＪＩＳ−Ｐ−３９０２に規定するＡ級２８０ｇ／ｍ²のライナーと、ＪＩＳ−Ｐ−３９０４に規定するＡ級１２５ｇ／ｍ²のセミ中芯を持つ厚さ５ｍｍのＡ級段ボールを、直角方向に幅５０ｍｍ、長さ２００ｍｍに切断し、両端から５０ｍｍを裏面より圧縮して、折り込み試験片とする。
テープは、２枚重ねてサンプリングし、縦方向に幅２５ｍｍ、長さ１５０ｍｍに切断する。折り込んだ段ボール試験片に、上記のテープを貼り付け、５００ｇの圧着ロール１往復で圧着する。圧着後、直ちに両側段ボール端部より２５ｍｍの部分に切り込みをいれ、段ボールに接する面積が２５ｍｍ×５０ｍｍになるようにする。このまま、温度２３±２℃、関係湿度６５±５％の雰囲気下に放置し、１日後のテープの剥がれを下記の評価基準で評価した。
◎：剥がれない。
○：剥がれないがズレがある。
×：剥がれる。
【０１１９】
〔粘着剤水再分散性〕粘着シートの粘着剤層面を、２０℃の水に浸しながら指で１０回擦った時の粘着剤の挙動を下記の評価基準にて評価した。
○：粘着剤層が粘着性のない細かい微粒子状に再分散した。
△：粘着剤層の粘着性は低下するが、細かく分散しないか凝集する。
×：粘着剤層の粘着性に変化はなく、粘着剤層皮膜が凝集した。
【０１２０】
〔リサイクル適性〕下記の二つの条件で保存した後のリサイクル適性をそれぞれ評価した。
条件Ａ：粘着シートおよび粘着テープの製造後、温度２３±２℃、関係湿度６５±５％の雰囲気下に７日間保存した後、そのリサイクル適性を評価した。
条件Ｂ：粘着シートおよび粘着テープの製造後、温度４０±２℃、関係湿度９０±５％の雰囲気下に７日間保存した後、そのリサイクル適性を評価した。
（評価試料の作成）▲１▼実施例１〜実施例７と比較例１〜比較例８と比較例１０、比較例１１の粘着シート：
封筒に貼付して使用される宛名用ラベルを想定して、粘着シートから剥離シートを剥がし粘着ラベルとし、市販の米坪６４ｇ／ｍ²の上質紙に貼付して評価用紙料とした。
▲２▼同じく粘着テープ：
古紙リサイクルが可能な包装材に貼付して使用される場合を想定して、粘着テープを市販の米坪６４ｇ／ｍ²の上質紙に貼り付けて評価用試料とした。
▲３▼実施例１〜実施例７と比較例１〜比較例１１の粘着シート：
剥離シートも含んだ粘着シートの形態での古紙リサイクルを想定して、粘着シートそのものを評価用試料とした。
【０１２１】
（評価）
約２０ｍｍ角の大きさにカットした試料４５ｇに対して、水１５００ｍｌを加え、さらにＮａＯＨ１ｇを加えてＴＡＰＰＩ標準離解機（ＪＩＳ−Ｐ−８２２０の付属書Ａに記載される装置）（３０００ｒｐｍ）にて３０分間処理した後、パルプ濃度が１５％になるまで６０メッシュのナイロンスクリーンで脱水し、１８％濃度のＮａＯＨ水溶液を１．５ｇ、脱墨剤（商品名：ＤＩ−６００／花王社製）１０％濃度溶液を１．８ｇそれぞれ添加し、４０℃で２０分間放置し、次にパルプ濃度が２５％になるまで６０メッシュのナイロンスクリーンで脱水し、３０％濃度のＮａＳｉＯ₃水溶液を３．８５ｇ、６％濃度のＨ₂Ｏ₂水を５ｇそれぞれ添加、次いで双腕式ニ−ダ−で５分間ニーディング処理を行った。
次に５５℃に保ちながら１２０分撹拌した後、パルプ濃度が１７．５％になるまで水で希釈し、次いで２回目のニーディング処理を同様に行った。その後更にパルプ濃度が１％になるまで水で希釈した。次に、この１％濃度のパルプ分散液をフローテーターにて１０分間浮上分離処理を行い、その際発生する泡をスクレーパーにて取り除き、もう一度６０メッシュのナイロンスクリーンで脱水後、水１０００ｍｌで洗浄し１３％濃度になるまで脱水した。この様にして得られたパルプ分散液を０．３％濃度になるまで水を加えて手抄きシートを作成し、未離解物の残存状態を目視し下記評価基準にて判定した。
【０１２２】
（リサイクル適性評価基準）
◎：未離解物がほとんどない。
○：未離解物が僅かにあるが、実用上問題ないレベル。
△：未離解物がかなり目立つ
×：未離解物あり、その未離解物に粘着性がある。
【０１２３】
〔総合評価〕
上記の各評価を総合して本発明のリサイクル可能な粘着シートおよび粘着テープとしての性能を評価した。
◎：基材の一面に粘着剤層を形成してなる粘着シートおよび粘着テープにおいて、粘着シートのままで、もしくは包装材に貼りつけたまま古紙リサイクルが可能であり、なお且つ粘着剤の接着性能において、接着力の熱湿劣化が少なく、凝集力も優れている。
○：基材の一面に粘着剤層を形成してなる粘着シートおよび粘着テープにおいて、粘着シートのままで、もしくは包装材に貼りつけたまま古紙リサイクルが可能であり、なお且つ粘着剤の接着性能において、凝集力が優れているが、接着力の熱湿劣化が若干あるものの問題はないレベルである。
△：粘着シートのままで、もしくは包装材に貼りつけたまま古紙リサイクルは可能であるが、粘着剤の凝集力が不十分であるか、接着力の熱湿劣化が著しいなど、接着性能の面で問題がある。
×：接着性能の優劣に関係なく、粘着シートのままで、もしくは包装材に貼りつけたまま古紙リサイクルは不可能である。
【０１２４】
【表１】

＊表中、リサイクル適性は、粘着ラベル／粘着シートのそれぞれの場合で評価した結果である。
【０１２５】
【表２】

【０１２６】
【発明の効果】
表１、２の如く、本発明の粘着シートおよび粘着テープは、粘着剤が水に容易に再分散することで古紙パルプとしてのリサイクル適性が優れており、且つ貼り付け時には必要な接着力を示し、包装材等に貼りつけたまま、或いは粘着シートのままでもリサイクル工程に混入しても容易に工程外へ除去される粘着シートおよび粘着テープであった。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an adhesive sheet or an adhesive tape. In more detail, the pressure-sensitive adhesive sheet and pressure-sensitive adhesive tape are excellent in re-disintegration property against water, and can be easily re-disaggregated without adversely affecting the pressure-sensitive adhesive and base material when regenerating pulp. The present invention relates to an adhesive sheet and an adhesive tape that can be mixed.
[0002]
[Prior art]
Adhesive sheets or adhesive tapes are used in a very wide range such as for commercial use, office use, stamps such as stamps, delivery slips, process management, and home use. The general structure of the pressure-sensitive adhesive sheet is such that a pressure-sensitive adhesive is sandwiched between the surface base material and the release sheet. On the other hand, the general structure of the pressure-sensitive adhesive tape is formed by laminating a release agent layer, a substrate, and a pressure-sensitive adhesive layer in this order, and has a release agent layer on the substrate surface and a pressure-sensitive adhesive layer on the opposite surface. .
[0003]
Paper, film, metal foil or the like is used for the substrate. A release agent such as a silicone compound or a fluorine compound is generally applied to the release sheet of the adhesive sheet or the adhesive tape substrate. The base material for the release sheet is a high-density base paper such as glassine paper, clay-coated paper, kraft paper, laminated paper obtained by laminating a resin film such as polyethylene on high-quality paper, or kraft paper or high-quality paper. Examples thereof include resin-coated paper provided with a coating layer mainly composed of a water-soluble polymer such as polyvinyl alcohol and starch, and a pigment. Among them, a laminated paper obtained by laminating polyethylene is generally widely used.
[0004]
As the adhesive, rubber-based, acrylic-based, vinyl ether-based emulsions, solvents, or various solvent-free adhesives are used. Such a pressure-sensitive adhesive sheet or pressure-sensitive adhesive tape is a permanent adhesive type that is affixed to a product or the like, is used for product packaging or cardboard packaging, and is permanently used after being affixed to an adherend. . In the case of the pressure-sensitive adhesive sheet, there is also a re-peeling type that is peeled off and discarded after the purpose of display is achieved from the relationship of the product or the like.
[0005]
On the other hand, regarding the recycling of waste paper, the amount of waste paper used, including waste paper for recycling, currently exceeds 50% of paper and paperboard production raw materials as a raw material for waste paper pulp production in Japan. To account for. Recycled pulp can be used in newspapers, cardboard, magazines, imitations, colors (including art), whites, cards, whites, medium whites, white Manila, tickets, Nakasara old, tea imitation papers (Western) ), Mount, ball, OCR paper, and the like. In general, waste paper is disaggregated to obtain a pulp suspension, followed by a coarse selection for separating foreign matter in the pulp suspension, a fine selection process, a deinking process for separating printing ink, and a bleaching process for whitening the color. Regenerated pulping takes place.
[0006]
For example, adhesive sheets and adhesive tapes can be used for delivery to homes that consist of slips printed in magazines, etc., as appendices, or printed on forms such as address labels, receipts, and slips. It is affixed to cardboard as a delivery slip, or affixed to a returnable box such as a plastic container as a distribution management label. Recently, it is also used for stamps and other stamps. Adhesive tapes are mainly used for packaging cardboard and the like, but in the paper industry, they are used for temporary fixing of winding after paper making and packaging at the time of shipment.
[0007]
However, wax-treated paper, pressure-sensitive adhesive sheets, pressure-sensitive adhesive labels, pressure-sensitive adhesive tapes, and the like are used papers that cannot separate water-insoluble waxes and pressure-sensitive adhesives from pulp fibers and are difficult to be recycled. Especially in the case of pressure-sensitive adhesive sheets, pressure-sensitive adhesive labels, and pressure-sensitive adhesive tapes, 5 to 50% of water-insoluble pressure-sensitive adhesive is contained, and furthermore, this pressure-sensitive adhesive has strong adhesive strength, so it cannot be separated from pulp fibers. It is said that. In addition, when used as a pressure-sensitive adhesive sheet for stamps, there are also those that can be peeled off in water by providing a water release layer on the back of the stamp so that stamp collectors can easily peel off stamps from substrates such as envelopes. However, since the adhesive remains on the substrates, it is difficult to regenerate these substrates.
[0008]
When paper is made using recycled pulp containing an adhesive component, the adhesive closes the eyes of the wire in the paper making process, or the press roll and blanket are soiled, causing paper breakage and significantly reducing the paper making efficiency. There arises a problem that the paper layer formation or the quality is adversely affected, such as a problem occurs or spots are formed on the paper surface.
[0009]
Furthermore, the release sheet used for the pressure-sensitive adhesive sheet and the base material for the pressure-sensitive adhesive tape are substrates having poor disintegration properties such as those using a laminated paper obtained by laminating polyethylene. Because of these problems, the actual situation is that recycled pulp from adhesive sheet waste paper, adhesive labels, packaging substrates with adhesive tape and corrugated cardboard has been avoided, and has become industrial waste. is there.
[0010]
Recently, due to problems such as forest resources and environmental protection, several cases have been reported where the adhesive products that are impossible to recycle as described above have been successfully recycled by devising them physically or deviceally. From the general waste paper processing method, all are special methods for removing the sticking foreign matter.
[0011]
In addition, a type using an adhesive that dissolves in water or alkaline water has been proposed, but in this case, since the adhesive dissolves, it completely adheres from the white water in the system of disaggregation and paper making. It was difficult to remove the agent component. Furthermore, since these pressure-sensitive adhesives are designed to have a low molecular weight, there is a drawback that the quality is remarkably deteriorated in a high temperature and high humidity environment.
[0012]
[Problems to be solved by the invention]
The present invention provides a recycled pulp from an adhesive sheet waste paper, an adhesive label, a packaging base material and a corrugated waste paper pasted with an adhesive tape, without removing the adhesive label and the adhesive tape in advance. Providing an adhesive sheet or adhesive tape that can be easily re-disaggregated and can be regenerated in the normal regenerated pulping process without contaminating the adjusted water at the time of disaggregation, and also stable in quality. There is to do.
[0013]
[Means for Solving the Problems]
The present invention includes (1) a pressure-sensitive adhesive sheet obtained by laminating a surface base material, a pressure-sensitive adhesive layer and a release sheet, wherein the surface base material is a base material that can be dissociated with water or an aqueous alkali solution, and the pressure-sensitive adhesive layer is against water. A re-disintegrating pressure-sensitive adhesive,
(A) (meth) acrylic acid alkyl ester monomer having an alkyl group having 4 to 18 carbon atoms: 45-80% by mass, (b) ethylenically unsaturated carboxylic acid-containing monomer: 5-15% by mass, (C) Methyl methacrylate: 1 to 10% by mass, (d) Monomer copolymerizable with a, b, c: 1 to 30% by mass, (poly) alkylene glycol di (meth) In a copolymer obtained by copolymerization in the presence of at least one of acrylate, (poly) alkylene glycol mono (meth) acrylate, (poly) ethylene glycol, and (poly) propylene glycol. It is a pressure-sensitive adhesive obtained by adding alkanolamine corresponding to 50 to 120 mol% of the carboxyl group, and the base material of the release sheet used is a direct type. Which is a pressure-sensitive adhesive sheet characterized.
The present invention also provides (2) a pressure-sensitive adhesive tape comprising a release agent layer / base material / pressure-sensitive adhesive layer laminated, wherein the pressure-sensitive adhesive layer has re-disintegration properties with respect to water, ,
(A) (meth) acrylic acid alkyl ester monomer having an alkyl group having 4 to 18 carbon atoms: 45-80% by mass, (b) ethylenically unsaturated carboxylic acid-containing monomer: 5-15% by mass, (C) Methyl methacrylate: 1 to 10% by mass, (d) Monomer copolymerizable with a, b, c: 1 to 30% by mass, (poly) alkylene glycol di (meth) In a copolymer obtained by copolymerization in the presence of at least one of acrylate, (poly) alkylene glycol mono (meth) acrylate, (poly) ethylene glycol, and (poly) propylene glycol. It is a pressure-sensitive adhesive obtained by adding alkanolamine corresponding to 50 to 120 mol% of the carboxyl group of the above, and is characterized in that the substrate used is a direct type. An adhesive tape.
[0014]
Further, in the present invention, (3) the number of added moles of alkylene glycol of (poly) alkylene glycol di (meth) acrylate or (poly) alkylene glycol mono (meth) acrylate used at the time of copolymerization of the pressure-sensitive adhesive is 1 to 23. The pressure-sensitive adhesive sheet or pressure-sensitive adhesive tape described in (1) or (2).
(4) The addition amount of (poly) alkylene glycol di (meth) acrylate or (poly) alkylene glycol mono (meth) acrylate is 0.1 to 5% by mass based on the total monomer mixture ( It is the adhesive sheet or adhesive tape as described in any one of 1)-(3).
(5) The pressure-sensitive adhesive sheet or pressure-sensitive adhesive tape according to any one of (1) to (4), wherein the (poly) alkylene glycol di (meth) acrylate is polyethylene glycol dimethacrylate.
(6) The addition amount of (poly) ethylene glycol and / or (poly) propylene glycol used at the time of copolymerization of the pressure-sensitive adhesive is 0.1 to 15% by mass with respect to the total monomer mixture. (1) It is an adhesive sheet or adhesive tape as described in any one of (5).
(7) The pressure-sensitive adhesive sheet according to any one of (1) to (6), wherein the alkanolamine that neutralizes the carboxyl group in the copolymer has a boiling point of 100 ° C or higher. It is an adhesive tape.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a pressure-sensitive adhesive sheet or pressure-sensitive adhesive tape which is extremely excellent when recycled pulp is formed by using a pressure-sensitive adhesive having particularly excellent redispersibility with respect to water. And in order to obtain such a recyclable pressure-sensitive adhesive sheet or pressure-sensitive adhesive tape, a composition having a specific monomer is changed to (poly) alkylene glycol di (meth) acrylate, (poly) alkylene glycol mono (meth) acrylate, polyethylene glycol And / or a pressure-sensitive adhesive obtained by copolymerizing in the presence of at least one of polypropylene glycol and adding an alkanolamine corresponding to 50 to 120 mol% of the carboxyl groups in the copolymer. There is a feature.
[0016]
The pressure-sensitive adhesive used in the pressure-sensitive adhesive sheet and pressure-sensitive adhesive tape of the present invention,
(A) (meth) acrylic acid alkyl ester monomer having an alkyl group having 4 to 18 carbon atoms: 45 to 80% by mass,
(B) ethylenically unsaturated carboxylic acid-containing monomer: 5 to 15% by mass,
(C) Methyl methacrylate: 1 to 10% by mass,
(D) Monomer copolymerizable with the above a, b, c ... 1-30% by mass,
Are copolymerized in the presence of at least one of (poly) alkylene glycol di (meth) acrylate, (poly) alkylene glycol mono (meth) acrylate, (poly) ethylene glycol, and (poly) propylene glycol. An alkanolamine corresponding to 50 to 120 mol% of the carboxyl group in the copolymer is added to the copolymer.
[0017]
(A) Examples of (meth) acrylic acid alkyl ester monomers having an alkyl group having 4 to 18 carbon atoms include butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, (meth) Examples include 2-ethylhexyl acrylate and stearyl (meth) acrylate. This monomer needs to be copolymerized so as to occupy 45 to 80% by mass of the copolymer. Incidentally, when it is less than 45% by mass, the adhesive strength of the pressure-sensitive adhesive becomes poor, and when it exceeds 80% by mass, the water redispersibility becomes insufficient.
[0018]
(B) Examples of the ethylenically unsaturated carboxylic acid-containing monomer include acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, monoalkylmaleic acid, monoalkylitaconic acid, and monoalkylfumaric acid. This monomer needs to be polymerized so as to occupy 5 to 15% by mass of the copolymer. Incidentally, if it is less than 5% by mass, the water re-dispersibility of the pressure-sensitive adhesive becomes insufficient, and if it exceeds 15% by mass, the pressure-sensitive adhesive force becomes insufficient and the pressure-sensitive adhesive easily deteriorates with time.
[0019]
(C) Methyl methacrylate needs to be copolymerized so as to occupy 1 to 10% by mass of the copolymer. If it is less than 1% by mass, the water redispersibility of the pressure-sensitive adhesive is insufficient, and if it exceeds 10% by mass, the adhesive strength is insufficient.
[0020]
(D) Other monomers copolymerizable with the above (a), (b), (c) include, for example, ethyl (meth) acrylate, propyl (meth) acrylate, cyclohexyl (meth) acrylate, ( Glycidyl acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, vinyl acetate, vinyl propionate, vinyl chloride, vinylidene chloride, styrene, ethylene, dimethylaminoethyl (meth) acrylate, (meta ) Alkoxyalkyl such as diethylaminoethyl acrylate, (meth) acrylonitrile, (meth) acrylamide, N-butoxymethyl (meth) acrylamide, divinylbenzene, N, N'-methylenebis (meth) acrylamide, methoxyethyl acrylate, ethoxyethyl acrylate (Meta) Examples include acrylates. This monomer needs to be copolymerized so as to occupy 1 to 30% by mass of the copolymer. Incidentally, if it is less than 1% by mass, the hydrophilicity of the pressure-sensitive adhesive becomes poor, and if it exceeds 30% by mass, the adhesive strength becomes insufficient.
[0021]
Among these other copolymerizable monomers (d), hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, vinyl acetate, (meth) acrylonitrile, (meth) acrylamide, N-methoxy When blended with alkoxyalkyl (meth) acrylates such as methyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N, N′-methylenebis (meth) acrylamide, methoxyethyl acrylate, ethoxyethyl acrylate, etc., It is preferable because a copolymer having suitable water redispersibility and adhesion performance can be obtained.
[0022]
(Poly) alkylene glycol di (meth) acrylate is a compound represented by the following general formula (1), for example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate , Tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate and the like.
[0023]
[Chemical 1]

[Wherein, R represents a methyl group or a hydrogen atom, and n represents an integer of 1 to 23. ]
[0024]
When the above copolymer is produced in the presence of (poly) alkylene glycol di (meth) acrylate, hydrophilicity can be imparted to the adhesive and at the same time the molecular weight can be increased, so that the redispersed particles become hard and recycled. Since the particles remaining in the process do not exhibit adhesiveness in water, an adhesive suitable for recycling can be produced. These compounds can be appropriately used in consideration of the balance of the hydrophilicity, water redispersibility, and adhesive performance of the pressure-sensitive adhesive. Among them, polyethylene glycol dimethacrylate is particularly excellent in hydrophilicity and water redispersibility. Since a copolymer is obtained, it is more preferable.
[0025]
In addition, it is necessary to add (poly) alkylene glycol di (meth) acrylate in the range of 0.1 to 5% by mass with respect to the total monomer mixture. Incidentally, if it is less than 0.1% by mass, the water redispersibility of the pressure-sensitive adhesive becomes insufficient. On the other hand, if it exceeds 5% by mass, the pressure-sensitive adhesive tends to aggregate during polymerization.
[0026]
(Poly) alkylene glycol mono (meth) acrylate is a compound represented by the following general formula (2), for example, ethylene glycol mono (meth) acrylate, diethylene glycol mono (meth) acrylate, triethylene glycol mono (meth) acrylate , Tetraethylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate and the like.
[0027]
[Chemical 2]

[Wherein, R represents a methyl group or a hydrogen atom, and n represents an integer of 1 to 23. ]
[0028]
When the above copolymer is produced in the presence of (poly) alkylene glycol mono (meth) acrylate, it is possible to impart hydrophilicity to the pressure-sensitive adhesive and at the same time plasticize the pressure-sensitive adhesive. Adhesives suitable for recycling with a balanced performance can be made.
[0029]
In addition, it is necessary to add (poly) alkylene glycol mono (meth) acrylate in the range of 0.1 to 5% by mass with respect to the total monomer mixture. Incidentally, if it is less than 0.1% by mass, the water redispersibility of the pressure-sensitive adhesive becomes insufficient. On the other hand, when it exceeds 5% by mass, the cohesive force of the pressure-sensitive adhesive is lowered. In addition, when the number of added moles of alkylene glycol of (poly) alkylene glycol di (meth) acrylate or (poly) alkylene glycol mono (meth) acrylate exceeds 23, the particles after re-dispersion are not so hard, Since the remaining particles exhibit tackiness in water, there is a possibility of adversely affecting the paper layer formation or quality during paper recycling.
[0030]
(Poly) ethylene glycol and / or (poly) propylene glycol are compounds represented by the following general formula (3).
[0031]
[Chemical 3]

[Wherein, R represents a methyl group or a hydrogen atom, and n represents an integer of 1 to 500. ]
[0032]
When the above copolymer is produced in the presence of (poly) ethylene glycol and / or (poly) propylene glycol, hydrophilicity can be imparted to the pressure-sensitive adhesive, so that a copolymer excellent in hydrophilicity and film swellability can be obtained. Adhesive suitable for recycling with good water redispersibility can be made.
[0033]
In addition, it is necessary to add (poly) ethylene glycol and / or (poly) propylene glycol in the range of 0.1 to 15% by mass, more preferably 0.3 to 10% by mass with respect to the total monomer mixture. Incidentally, if it is less than 0.1% by mass, the water redispersibility of the pressure-sensitive adhesive becomes insufficient. On the other hand, if it exceeds 15% by mass, the viscosity tends to increase, and the handleability of the pressure-sensitive adhesive decreases.
[0034]
Examples of the alkanolamine include monoethanolamine, diethanolamine, triethanolamine, propanolamine, β-propanolamine, tripropanolamine, isopropanolamine, triisopropanolamine, 2-aminoisohexyl alcohol, N-methyldiethanolamine, N, N- Examples include dibutylethanolamine. These alkanolamines need to be added so as to correspond to 50 to 120 mol% of the carboxyl groups in the copolymer. Incidentally, if it is less than 50 mol%, the adhesive film has insufficient adhesiveness and water redispersibility, and if it exceeds 120 mol%, the holding power is insufficient, and the adhesive is deteriorated or discolored over time. It becomes easy.
[0035]
Among these alkanolamines, an alkanol having a boiling point of 100 ° C. or higher, more preferably 170 ° C. or higher is preferable in order to prevent volatilization in the drying process during the production of the pressure-sensitive adhesive sheet or pressure-sensitive adhesive tape or change in quality after time. It is desirable to use an amine.
[0036]
Here, at least one of the above-mentioned monomers for the pressure-sensitive adhesive of the present invention, (poly) alkylene glycol di (meth) acrylate, (poly) alkylene glycol mono (meth) acrylate, polyethylene glycol and / or polypropylene glycol added at the time of copolymerization The role of the alkanolamine added to the adhesive copolymer will be briefly described. As the component for imparting water redispersibility of the adhesive, (b) an ethylenically unsaturated carboxylic acid-containing monomer and (c) Methyl methacrylate is important, and as components for imparting the tackiness of the pressure-sensitive adhesive, (a) a (meth) acrylic acid alkyl ester monomer having an alkyl group having 4 to 18 carbon atoms, and (b) ethylenically unsaturated Carboxylic acid-containing monomers and (c) methyl methacrylate are important. In addition, as a component that imparts hydrophilicity to the pressure-sensitive adhesive and further adjusts the pressure-sensitive adhesive, (d) other monomers copolymerizable with the above (a), (b), and (c) are important. Further, when these pressure-sensitive adhesive composition mixtures are copolymerized in the presence of at least one of (poly) alkylene glycol di (meth) acrylate, (poly) alkylene glycol mono (meth) acrylate, polyethylene glycol and / or polypropylene glycol, Further, since hydrophilicity can be imparted to the pressure-sensitive adhesive and the molecular weight can be increased at the same time, the particles after re-dispersion become hard and the particles remaining in the recycling process do not exhibit adhesiveness in water. In addition, when alkanolamine is used in the neutralization reaction carried out to develop the adhesiveness and water redispersibility of these copolymers, it is possible to prevent the copolymer from being plasticized and the water redispersibility from deteriorating over time. . These (a), (b), (c), (d) and (poly) alkylene glycol di (meth) acrylate, (poly) alkylene glycol mono (meth) acrylate, polyethylene glycol and / or polypropylene glycol By blending one type and alkanolamine as an essential component in a well-balanced manner, the copolymer has redispersibility in water without impairing the adhesive strength, and the redispersed particles are sticky in water. It becomes an adhesive that does not.
[0037]
Furthermore, a hydrophilic plasticizing substance can be added to the above-mentioned pressure-sensitive adhesive in order to adjust the physical properties of the pressure-sensitive adhesive and prevent discoloration and deterioration of the pressure-sensitive adhesive over time. Examples of hydrophilic plasticizing substances include sugar alcohols such as glycerin, sorbit, mannitol, dulcit, exit, erythrite, arabit, adnit, polyethylene oxide or polypropylene oxide and glycerin, xylit trioxyisobutane, sorbit, etc. Copolymers with polyhydric alcohols, polyether polyols such as polyethylene glycol and polypropylene glycol, copolymers of ethylene oxide and propylene oxide, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene polyoxy Nonionic surfactants such as propylene glycol are listed. In consideration of tackiness and water redispersibility, this substance should be used in an amount of 10% by mass or less, more preferably 0.5 to 10% by mass with respect to 100% by mass of the copolymer. Is desirable.
[0038]
Among these hydrophilic plasticizing substances, nonionic surfactants are particularly preferable because they can finish a pressure-sensitive adhesive having good adhesion and storage stability.
[0039]
Therefore, in order to obtain a pressure-sensitive adhesive having excellent redispersibility with respect to water and good adhesion performance used in the present invention, (a) having an alkyl group having 4 to 18 carbon atoms (meta (B) ethylenically unsaturated carboxylic acid-containing monomer, (c) methyl methacrylate, (d) other monomer copolymerizable with them, and (poly) alkylene glycol diester It is very important to copolymerize in the presence of (meth) acrylate and neutralize with alkanolamine.
[0040]
The method for producing the copolymer is not particularly limited. For example, a solution polymerization method in the presence of water, a solvent, a chain transfer agent, a polymerization initiator, an emulsifier, a chain transfer agent, or the like. And a known method such as a method of emulsion polymerization in an aqueous system in the presence of a polymerization initiator, a dispersant and the like.
[0041]
Examples of the polymerization initiator used in the polymerization include persulfates such as potassium persulfate and ammonium persulfate, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethyl). Azo compounds such as valeronitrile), peroxides such as hydrogen peroxide, benzoyl peroxide, lauryl peroxide, so-called redox polymerization initiators, etc., which are a combination of ammonium persulfate and sodium sulfite, acidic sodium sulfite, etc. Is mentioned. The usage-amount of a polymerization initiator is 0.2-2 mass% normally with respect to the monomer whole quantity which co-polymerizes, More preferably, it is about 0.3-1 mass%.
[0042]
Chain transfer agents added during copolymerization include alkyl mercaptans such as octyl mercaptan, nonyl mercaptan, decyl mercaptan, dodecyl mercaptan, N-dodecyl mercaptan, octyl thioglycolate, nonyl thioglycolate, 2-ethylhexyl thioglycolate Thioglycolic acid esters such as β-mercaptopropionic acid-2-ethylhexyl, 2,4-diphenyl-4-methyl-1-pentene, 1-methyl-4-isopropylidene-1-cyclohexene, and the like. . In particular, when thioglycolic acid esters, 2,4-diphenyl-4-methyl-1-pentene, and 1-methyl-4-isopropylidene-1-cyclohexene are used, the resulting copolymer has a low odor. preferable. In addition, the usage-amount of a chain transfer agent is adjusted to about 0-3 mass% of all the monomers to superpose | polymerize. Moreover, organic solvents, such as methanol, ethanol, and isopropyl alcohol, can also be used.
[0043]
The monomer concentration at the time of polymerization is usually 30 to 70% by mass, preferably about 40 to 60% by mass. Moreover, a polymerization reaction is normally performed over 2-8 hours on 60-100 degreeC temperature conditions. Furthermore, wetting agents, leveling agents, thickeners, antifoaming agents, preservatives and the like can be added as appropriate. In addition, if desired, for the purpose of improving the performance of the pressure-sensitive adhesive, particularly physical properties such as adhesive strength and cohesive strength to the polyolefin-based adherend, ethylene-vinyl acetate copolymer, ethylene-vinyl acetate-acrylic copolymer A coalescence can also be added.
[0044]
The copolymer obtained by the above method needs to be neutralized with an alkanolamine corresponding to 50 to 120 mol% of the carboxyl groups in the copolymer. By performing the neutralization treatment, the mechanical stability can be improved and the viscosity can be adjusted.
[0045]
In addition to alkanolamine, alkali metal hydroxides such as potassium hydroxide and sodium hydroxide, ammonia and the like can be used in combination for neutralization of the carboxyl group in the copolymer. From the viewpoint of change in adhesive performance due to volatilization with time after being processed into an adhesive tape and prevention of deterioration of water redispersibility, alkali metal hydroxides such as potassium hydroxide are more preferably used.
[0046]
The glass transition temperature of the above copolymer is in the range of −70 to −10 ° C., and is appropriately selected according to the purpose. Incidentally, when the glass transition temperature of the copolymer is less than −70 ° C., the cohesive force of the resulting film becomes insufficient. There is a tendency to become less practical.
[0047]
In the present invention, by using such a copolymer as a pressure-sensitive adhesive, a pressure-sensitive adhesive sheet or pressure-sensitive adhesive tape that can be mixed in the waste paper recycling process is obtained.
[0048]
Next, as the surface base material that can be disaggregated with water or alkaline aqueous solution used for adhesive sheets, high-quality paper, art paper, coated paper, cast paper, craft paper, impregnated paper, low-size paper, water-soluble paper, kraft paper or high-quality paper For example, casein, dextrin, starch, carboxymethylcellulose, methylcellulose, ethylcellulose, hydroxyethylcellulose, polyvinyl alcohol, styrene-butadiene copolymer, methylmethacrylate-butadiene copolymer, ethylene-vinyl chloride copolymer, ethylene-acetic acid. Paper such as a base material provided with a sealing layer mainly composed of natural or synthetic resins and / or pigments such as vinyl copolymers and acrylic acid ester copolymers, polyvinyl alcohol, carboxymethyl cellulose, methyl cellulose, etc. From water-soluble polymers Water-soluble film formed, or copolymerization of lactic acid or lactide with glycolic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxypentanoic acid, hydroxycaproic acid, hydroxyheptanoic acid or other lactic acid polymers such as polylactic acid A film or the like that is easily hydrolyzed with a more shaped alkaline aqueous solution can be used.
[0049]
Next, the direct type substrate used for the release sheet of the adhesive sheet or the base material of the adhesive tape is a release paper substrate that is not laminated with polyethylene or the like, and is clay coated paper, glassine paper, kraft paper or For example, casein, dextrin, starch, carboxymethylcellulose, methylcellulose, ethylcellulose, hydroxyethylcellulose, polyvinyl alcohol, styrene-butadiene copolymer, methylmethacrylate-butadiene copolymer, ethylene-vinyl chloride copolymer, ethylene- Examples thereof include a base material provided with a sealing layer mainly composed of a natural or synthetic resin and / or a pigment such as a vinyl acetate copolymer and an acrylate copolymer.
[0050]
In addition, as for the papers used for the surface base material of an adhesive sheet, a peeling sheet, and the base material of an adhesive tape, it is desirable to use the paper whose pH is 6 or less. This is because, in the region where the paper layer pH is higher than 6, the hydrophilic component in the pressure-sensitive adhesive composition, particularly the compound having a carboxyl group, is influenced by calcium carbonate contained in the coating layer such as paper or coated paper. This is because the adhesive is easily deteriorated. In addition, the paper layer pH referred to here is the surface of the pressure-sensitive adhesive sheet, in the case of a release sheet, the surface opposite to the surface on which the pressure-sensitive adhesive or release agent is applied, and in the case of a pressure-sensitive adhesive tape substrate, the pressure-sensitive adhesive is an organic solvent. The surface that has been swollen and scraped off is peeled off using a cellophane tape to expose the base paper layer, and a test solution that changes color depending on the commercially available pH (for example, a pH meter for measuring the paper surface, manufactured by Kyoritsu Riken) Is obtained by coating the paper with a standard color.
[0051]
In addition, the sealing layer mainly composed of a resin and / or pigment used in a direct type substrate used for a release sheet of an adhesive sheet or an adhesive tape substrate is not particularly limited. For example, casein, dextrin , Starch, carboxymethyl cellulose, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol, styrene-butadiene copolymer, methyl methacrylate-butadiene copolymer, ethylene-vinyl chloride copolymer, acrylic ester copolymer, etc. Resin and / or kaolin, calcium carbonate, clay, talc, calcined kaolin, deramikaolin, titanium dioxide, aluminum hydroxide, silica, white carbon, and other inorganic pigments, or polystyrene resin fine particles, urine - it can be used formalin resin fine particles, organic synthetic pigments such as fine hollow particles.
[0052]
In addition to the base material provided with the sealing layer, a base material provided with a printing coating layer mainly composed of a pigment on the paper surface, such as art paper, coated paper, cast coated paper, etc., is used. May be. Of course, if necessary, a substrate that has been printed in advance can be applied.
[0053]
In addition, when providing the said pigment coating layer, an adhesive agent is used in order to fix pigments and the pigment and the surface of a base material other than a pigment in a pigment coating liquid. Examples of such adhesives include casein, dextrin, starch, carboxymethyl cellulose, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol, styrene-butadiene copolymer, methyl methacrylate-butadiene copolymer, ethylene-vinyl chloride copolymer, ethylene. -Natural or synthetic adhesives such as vinyl acetate copolymers, acrylate copolymers etc. are used in the form of aqueous solutions or aqueous dispersions (emulsions). In addition to these pigments and adhesives, various auxiliary agents such as antifoaming agents, dispersants, preservatives, dyes and the like are added to the pigment coating solution as necessary, as long as the properties are not impaired. You can also.
[0054]
The sealing layer coating liquid mainly composed of the resin and / or pigment is a normal coating apparatus such as a blade coater, a bar coater, an air knife coater, a gravure coater, a roll coater, a die coater, or a lip coater. Coated. The coating amount in this case is 2 g / m in terms of solid content. ² Or more, preferably 4 to 30 g / m ² Adjusted in the range of.
[0055]
Next, the release agent used in the release sheet for the pressure-sensitive adhesive sheet of the present invention and the release agent layer formed on one surface of the base material for the pressure-sensitive adhesive tape is not particularly limited, and is generally used as a water dispersion type, solvent type, or solventless type. 0.05-3 g / m of dry weight of silicone resin or fluororesin ² After coating to a certain extent, a layer having a release layer formed by heat curing, ionizing radiation curing or the like is used. Among these, solventless silicone is more preferably used because it does not use a harmful solvent during the formation of the release layer, and is excellent in drying efficiency as compared with the water dispersion type.
[0056]
Recently, as a form of adhesive label, a tape-like one without release paper has been developed from the viewpoint of resource saving, but in this case, it is separated from the printing surface of printing paper such as art paper or coated paper. Such a layer may be used in place of the release agent layer.
[0057]
The pressure-sensitive adhesive sheet is usually formed by applying a pressure-sensitive adhesive on the release sheet surface of the release sheet, drying to provide a pressure-sensitive adhesive layer, and then sticking it to the surface base material. An adhesive layer may be provided by coating an adhesive.
[0058]
The method of forming the adhesive tape is usually finished by applying the adhesive directly to the back of the base material provided with the release agent layer or the releasable printing layer, and drying to provide the adhesive layer. After applying the adhesive to the release agent layer side of the release paper and drying it, bonding the back of the tape substrate with the release agent layer and the releasable print layer on the surface and finishing it to an adhesive sheet, release sheet You may finish to an adhesive tape, removing.
[0059]
When forming an adhesive sheet or adhesive tape, the adhesive is usually applied to the release sheet by adjusting the molecular weight, diluting with water, or increasing the viscosity to a viscosity of about 0.01 to 9 Pascal seconds. The As the coating apparatus in this case, for example, a reverse roll coater, a knife coater, an air knife coater, a bar or rod coater, a slot die coater, a lip coater, a reverse gravure coater or the like is used. In the pressure-sensitive adhesive sheet and pressure-sensitive adhesive tape of the present invention, the coating apparatus is not particularly limited, and is produced by these general methods. The coating amount of the adhesive varies depending on the purpose, but 3 g / m. ² Or more, more preferably 5 to 50 g / m ² Adjusted to the extent of the degree. Incidentally, 3g / m ² Is less than 50 g / m, the adhesive performance of the resulting adhesive sheet or adhesive tape is insufficient. ² If it exceeds 1, the pressure-sensitive adhesive may protrude during the production of the pressure-sensitive adhesive sheet or pressure-sensitive adhesive tape, or may cause cohesive failure during peeling.
[0060]
【Example】
Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. Unless otherwise specified, all parts, ratios, coating amounts, etc. in the examples are expressed in terms of solid content or active ingredient mass.
[0061]
Example 1
(Manufacture of adhesives)
First, as an emulsified monomer mixture,
2-ethylhexyl acrylate: 250 parts
Acrylic acid: 35 parts
(Meth) methyl acrylate: 20 parts
Methoxyethyl acrylate: 75 parts
Vinyl acetate: 20 parts
Anionic emulsifier (trade name: EMAL NC-35 / manufactured by Kao Corporation): 6 parts
Ion exchange water: 150 parts
0.9 mass% of polyethylene glycol dimethacrylate (trade name: NK ester A-4G / manufactured by Shin-Nakamura Chemical Co., Ltd.) is added to the total monomer mixture excluding the emulsifier and ion-exchanged water (the same applies hereinafter). Prepared.
[0062]
Next, 150 parts of ion-exchanged water, 3 parts of potassium persulfate, and 3 parts of octyl mercaptan were charged into a flask equipped with a stirrer, cooler, dropping funnel, nitrogen suction tube and thermometer, and the temperature was raised to 80 ° C. while purging with nitrogen. After that, 1/6 of the emulsion monomer mixture was dropped. When the reaction rate reached 90%, the remaining monomer mixture was added dropwise over 3 hours to perform polymerization. After completion of the dropping, the reaction was completed by aging at 80 ° C. for 3 hours. Next, the flask contents are cooled to 40 ° C., 50 mol% of carboxyl groups in the copolymer is added to carry out a neutralization reaction, and the mixture is vigorously stirred after completion of the reaction to be used in the present invention. Manufactured.
[0063]
(Creation of release paper base with sealing layer)
As coating liquid, kaolin (trade name: manufactured by HT Clay / Engelhard): 50 parts, acrylic ester copolymer (trade name: Ricabond ET-84 / manufactured by Chuo Rika Co., Ltd.): 50 parts, lubricant (product) Name: Nopco C-104 / manufactured by San Nopco): 0.5 part, antifoaming agent (trade name: Nopco 1407K / manufactured by San Nopco): 0.3 part, the solid content concentration becomes 50% The mixture was prepared as above, and a commercially available rice tsubo 64 g / m ² 5g / m dry mass on high quality paper ² It was coated and dried so that a sealing layer was provided. Next, smooth finishing was performed with a super calendar to obtain a base material for release paper.
[0064]
Next, a solvent-type silicone release agent (trade name: LTC-300B / manufactured by Toray Dow Corning): 100 parts, catalyst (trade name: SRX-212 /) on the sealing layer of the release paper substrate thus obtained. Toray Dow Corning): 0.8 parts dry weight 1.0g / m ² It was coated and heat-cured.
[0065]
(Preparation of adhesive sheet)
On the release paper, the obtained pressure-sensitive adhesive is 25 g / m in dry mass. ² After being coated and dried so that it becomes ² A pressure-sensitive adhesive sheet was obtained by laminating with high-quality paper.
[0066]
(Creation of tape base material with a sealing layer)
As a coating solution, kaolin (trade name: KCS clay / manufactured by ECC): 70 parts, phosphate esterified starch (trade name: Neil Gum A-85 / manufactured by Matsutani Chemical): 5 parts, SBR latex (trade name: L-1795 / manufactured by Asahi Kasei Co., Ltd.): 25 parts, dispersant (trade name: Aron A-9 / manufactured by Toagosei Chemical Industry Co., Ltd.): 0.2 part, so that the solid content concentration becomes 40% 73g / m ² 10g / m dry weight on kraft paper ² It was coated and dried so that a sealing layer was provided.
[0067]
Next, a solvent-type silicone release agent (trade name: SD-7220 / manufactured by Dow Corning Toray): 100 parts of catalyst (trade name: SRX-212 /) on the sealing layer of the tape substrate thus obtained. Toray Dow Corning Co., Ltd.): 0.6 parts dry weight of 1.0 g / m ² It was coated and heat-cured.
[0068]
(Creation of adhesive tape)
40 g / m in dry mass of the pressure-sensitive adhesive on the back surface of the tape substrate provided with the release agent layer ² After being coated and dried so as to become, the pressure-sensitive adhesive layer and the release agent layer surface of the tape substrate were bonded together to prepare the pressure-sensitive adhesive tape of the present invention.
[0069]
Example 2
(Manufacture of adhesives)
First, as an emulsified monomer mixture,
2-ethylhexyl acrylate: 330 parts
Acrylic acid: 60 parts
(Meth) methyl acrylate: 5 parts
Vinyl acetate: 5
Anionic emulsifier (trade name: EMAL NC-35 / manufactured by Kao Corporation): 6 parts
Ion exchange water: 150 parts
And 1.8% by mass of polyethylene glycol dimethacrylate (trade name: NK ester 9G / manufactured by Shin-Nakamura Chemical Co., Ltd.) and polypropylene glycol (manufactured by Wako Pure Chemical Industries, Ltd./average molecular weight 1000) with respect to the total monomer mixture. It was prepared by adding 2.7% by mass.
Next, a copolymer was produced in the same manner as in Example 1, and neutralization reaction was performed by adding 50% by mole of carboxyl groups in the copolymer to each of triethanolamine and 10% aqueous potassium hydroxide.
Furthermore, 4 parts of a nonionic surfactant (trade name: Emulgen 810 / manufactured by Kao Corporation): 100 parts of this adhesive was added and stirred vigorously to produce an adhesive used in the present invention.
[0070]
A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive was used.
[0071]
A pressure-sensitive adhesive tape was prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive was used.
[0072]
Example 3
(Manufacture of adhesives)
First, as an emulsified monomer mixture,
2-ethylhexyl acrylate: 250 parts
Acrylic acid: 25 parts
(Meth) methyl acrylate: 40 parts
Methoxyethyl acrylate: 75 parts
Vinyl acetate: 10 parts
Anionic emulsifier (trade name: EMAL NC-35 / manufactured by Kao Corporation): 6 parts
Ion exchange water: 150 parts
2.7% by mass of polyethylene glycol dimethacrylate (trade name: NK Ester 9G / manufactured by Shin-Nakamura Chemical Co., Ltd.) and polypropylene glycol (manufactured by Wako Pure Chemical Industries, Ltd./average molecular weight 1000) with respect to the total monomer mixture. 4.0 mass% was added and prepared.
Next, an adhesive was produced in the same manner as in Example 2.
[0073]
A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive was used.
[0074]
A pressure-sensitive adhesive tape was prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive was used.
[0075]
Example 4
(Manufacture of adhesives)
First, as an emulsified monomer mixture,
2-ethylhexyl acrylate: 190 parts
Acrylic acid: 35 parts
(Meth) methyl acrylate: 20 parts
Methoxyethyl acrylate: 90 parts
Vinyl acetate: 25 parts
Anionic emulsifier (trade name: EMAL NC-35 / manufactured by Kao Corporation): 6 parts
Ion exchange water: 150 parts
And 2.7% by mass of polyethylene glycol monomethacrylate (trade name: Blemmer PE-200 / manufactured by NOF Corporation) was added to the total monomer mixture.
Next, a copolymer was produced in the same manner as in Example 1, and neutralization reaction was performed by adding 100 mol% of carboxyl groups in the copolymer to triethanolamine.
Furthermore, 4 parts of a nonionic surfactant (trade name: Emulgen 810 / manufactured by Kao Corporation): 100 parts of this adhesive was added and stirred vigorously to produce an adhesive used in the present invention.
[0076]
A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive was used.
[0077]
A pressure-sensitive adhesive tape was prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive was used.
[0078]
Example 5
(Manufacture of adhesives)
The emulsified monomer mixture was carried out except that 0.9% by mass of polyethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd./average molecular weight 1000) was added to the mixture having the same monomer composition as in Example 1 to prepare the mixture. A pressure-sensitive adhesive was produced in the same manner as in Example 1.
[0079]
A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive was used.
[0080]
A pressure-sensitive adhesive tape was prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive was used.
[0081]
Example 6
(Manufacture of adhesives)
First, as an emulsified monomer mixture,
2-ethylhexyl acrylate: 290 parts
Acrylic acid: 35 parts
(Meth) methyl acrylate: 20 parts
Methoxyethyl acrylate: 35 parts
Vinyl acetate: 20 parts
Anionic emulsifier (trade name: EMAL NC-35 / manufactured by Kao Corporation): 6 parts
Ion exchange water: 150 parts
And 1.8% by mass of polyethylene glycol dimethacrylate (trade name: NK ester 9G / manufactured by Shin-Nakamura Chemical Co., Ltd.) and polypropylene glycol (manufactured by Wako Pure Chemical Industries, Ltd./average molecular weight 1000) with respect to the total monomer mixture. 4.0 mass% was added and prepared.
Next, an adhesive was produced in the same manner as in Example 2.
[0082]
(Creation of surface substrate and adhesive tape substrate)
As a coating solution, kaolin (trade name: UW-90 / EMC): 70 parts, heavy calcium carbonate (trade name: Hydrocurve K-6 / Bihoku Powder Chemical Co., Ltd.): 30 parts, phosphorylated esterification Starch (trade name: Neil Gum A-55C / Abebe): 1 part, oxidized starch (trade name: Ace A / Oji Cornstarch): 8 parts, SBR latex (trade name: T-2257 / Nippon Synthetic Rubber) Manufactured): 8 parts, dispersant (trade name: Aron A-9 / manufactured by Toagosei Chemical Industry Co., Ltd.): a composition comprising 0.1 part is mixed and prepared so as to have a solid content concentration of 60%. A composition was obtained.
The coating composition thus obtained is a commercially available rice tsubo 64 g / m. ² 20g / m dry mass on high quality paper ² The pigment coating layer was provided by coating and drying. Next, gloss finishing was performed with a super calender to finish the surface base material.
[0083]
Next, a solvent-free silicone release agent (trade name: LTC-1073L / manufactured by Toray Dow Corning): 100 parts, catalyst (trade name: LTC-1100M /) on the pigment coating layer of the base material thus obtained. Toray Dow Corning): 10 parts dry mass 1.0g / m ² It was coated and heat-cured so as to be a base material for an adhesive tape.
[0084]
A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 using the pressure-sensitive adhesive and the surface base material.
[0085]
A pressure-sensitive adhesive tape was produced in the same manner as in Example 1 using the pressure-sensitive adhesive and the tape substrate.
[0086]
Example 7
A pressure-sensitive adhesive sheet and a pressure-sensitive adhesive tape were prepared in the same manner as in Example 6 except that the following base materials were used as the surface base material and the base material for the pressure-sensitive adhesive tape.
[0087]
(Creation of surface substrate and adhesive tape substrate)
As coating liquid, kaolin (trade name: UW-90 / EMC): 45 parts, calcium carbonate (trade name: Brilliant S-15 / Shiraishi Kogyo Co.): 55 parts, latex (trade name: L-1392) / Asahi Kasei Co., Ltd.): 21 parts, Casein (trade name: Arashid / New Zealand Casein Co., Ltd.): 5.43 parts, Dispersant (trade name: Nankaline S-1 / Rin Chemical Co., Ltd.): 0.0675 parts Foaming agent (trade name: Bismer FX-10 / manufactured by Nisshin Chemical Co., Ltd.): 0.3 part, release agent (trade name: Hydrin Z-8 / manufactured by Chukyo Yushi Co., Ltd.) 0.8 part, zinc sulfate: 3 parts The composition consisting of the above was mixed and prepared so as to have a solid content concentration of 47%, and a commercially available rice basis weight of 64 g / m ² On dry paper of 25 g / m ² Coated, dried, and smoothed with a super calender, and while the coating layer is in a wet state, the surface of the coating layer is pressed against a heated metal drum by a rewet method, and cast finish is performed. A substrate was obtained.
[0088]
Next, a solvent-free silicone release agent (trade name: LTC-1073L / manufactured by Toray Dow Corning): 100 parts, catalyst (trade name: LTC-1100M /) on the pigment coating layer of the base material thus obtained. Toray Dow Corning): 10 parts dry mass 1.0g / m ² It was coated and heat-cured so as to be a base material for an adhesive tape.
[0089]
Comparative Example 1
(Manufacture of adhesives)
First, as an emulsified monomer mixture,
2-ethylhexyl acrylate: 250 parts
Acrylic acid: 35 parts
(Meth) methyl acrylate: 20 parts
Methoxyethyl acrylate: 75 parts
Vinyl acetate: 20
Anionic emulsifier (trade name: EMAL NC-35 / manufactured by Kao Corporation): 6 parts
Ion exchange water: 150 parts
Were mixed and prepared.
[0090]
Next, a copolymer was produced in the same manner as in Example 1, and 50 mol% of the carboxyl group in the copolymer was added to triethanolamine to carry out a neutralization reaction to obtain an adhesive.
[0091]
A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive was used.
[0092]
A pressure-sensitive adhesive tape was prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive was used.
[0093]
Comparative Example 2
(Manufacture of adhesives)
As an emulsion monomer mixture,
2-ethylhexyl acrylate: 260 parts
Acrylic acid: 15 parts
(Meth) methyl acrylate: 30 parts
Methoxyethyl acrylate: 75 parts
Vinyl acetate: 20 parts
Anionic emulsifier (trade name: EMAL NC-35 / manufactured by Kao Corporation): 6 parts
Ion exchange water: 150 parts
And 1.8% by mass of polyethylene glycol dimethacrylate (trade name: NK ester 9G / manufactured by Shin-Nakamura Chemical Co., Ltd.) and polypropylene glycol (manufactured by Wako Pure Chemical Industries, Ltd./average molecular weight 1000) with respect to the total monomer mixture. It was prepared by adding 2.7% by mass.
Next, an adhesive was produced in the same manner as in Example 2.
[0094]
A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive was used.
[0095]
A pressure-sensitive adhesive tape was prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive was used.
[0096]
Comparative Example 3
(Manufacture of adhesives)
As an emulsion monomer mixture,
2-ethylhexyl acrylate: 345 parts
Acrylic acid: 50 parts
(Meth) methyl acrylate: 5 parts
Anionic emulsifier (trade name: EMAL NC-35 / manufactured by Kao Corporation): 6 parts
Ion exchange water: 150 parts
2.7% by mass of polyethylene glycol dimethacrylate (trade name: NK Ester 9G / manufactured by Shin-Nakamura Chemical Co., Ltd.) and polypropylene glycol (manufactured by Wako Pure Chemical Industries, Ltd./average molecular weight 1000) with respect to the total monomer mixture. 4.0 mass% was added and prepared.
Next, a pressure-sensitive adhesive was produced in the same manner as in Example 4.
[0097]
A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive was used.
[0098]
A pressure-sensitive adhesive tape was prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive was used.
[0099]
Comparative Example 4
(Manufacture of adhesives)
As an emulsion monomer mixture,
2-ethylhexyl acrylate: 195 parts
Acrylic acid: 25 parts
(Meth) methyl acrylate: 45 parts
Methoxyethyl acrylate: 115 parts
Vinyl acetate: 20 parts
Anionic emulsifier (trade name: EMAL NC-35 / manufactured by Kao Corporation): 6 parts
Ion exchange water: 150 parts
And 2.7% by mass of polyethylene glycol monomethacrylate (trade name: Blemmer PE-200 / manufactured by NOF Corporation) was added to the total monomer mixture.
Next, a pressure-sensitive adhesive was produced in the same manner as in Example 4.
[0100]
A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive was used.
[0101]
A pressure-sensitive adhesive tape was prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive was used.
[0102]
Comparative Example 5
(Manufacture of adhesives)
As an emulsified monomer mixture, 0.9% by mass of polyethylene glycol dimethacrylate (trade name: NK Ester 9G / manufactured by Shin-Nakamura Chemical Co., Ltd.) was added to the mixture having the same monomer composition as in Example 1. .
Next, a copolymer was produced in the same manner as in Example 1, neutralized with aqueous ammonia, and stirred strongly after the reaction to produce an adhesive used in the present invention.
[0103]
A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive was used.
[0104]
A pressure-sensitive adhesive tape was prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive was used.
[0105]
Comparative Example 6
(Manufacture of adhesives)
An emulsion monomer mixed solution was prepared in the same manner as in Comparative Example 5, then a copolymer was produced in the same manner as in Example 1, and then neutralized by adding 150 mol% of the carboxyl groups in the copolymer to triethanolamine. The reaction was performed, and after the reaction was completed, the mixture was vigorously stirred to produce an adhesive used in the present invention.
[0106]
A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive was used.
[0107]
A pressure-sensitive adhesive tape was prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive was used.
[0108]
Comparative Example 7
As the pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive (trade name: Nicazole L-145 / manufactured by Nippon Carbide Industries Co., Ltd.) that is insoluble in water and alkaline aqueous solution is 22 g / m in dry mass. ² A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 7 except that coating and drying were performed.
[0109]
Comparative Example 8
A commercially available polyethylene-laminated kraft paper adhesive tape (trade name: OJI Kraft Tape / manufactured by Oji Chemical Co., Ltd.) was used as an adhesive tape and used as an evaluation sample.
[0110]
Comparative Example 9
An adhesive sheet and an adhesive tape were prepared in the same manner as in Example 6 except that a commercially available polyethylene laminated paper was used as the release paper substrate and the adhesive tape substrate.
[0111]
Comparative Example 10
A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that a commercially available polyethylene terephthalate film (manufactured by Toyobo Co., Ltd.) was used as the surface substrate.
[0112]
Comparative Example 11
(Manufacture of adhesives)
As an emulsion monomer mixture,
2-ethylhexyl acrylate: 310 parts
Acrylic acid: 65 parts
(Meth) methyl acrylate: 5 parts
Vinyl acetate 20
Anionic emulsifier (trade name: EMAL NC-35 / manufactured by Kao Corporation): 6 parts
Ion exchange water: 150 parts
And 1.8% by mass of polyethylene glycol dimethacrylate (trade name: NK ester 9G / manufactured by Shin-Nakamura Chemical Co., Ltd.) and polypropylene glycol (manufactured by Wako Pure Chemical Industries, Ltd./average molecular weight 1000) with respect to the total monomer mixture. It was prepared by adding 2.7% by mass.
Next, a copolymer was produced in the same manner as in Example 2, and the neutralization reaction was carried out by adding 50 mol% of each carboxyl group in the copolymer with triethanolamine and 10% aqueous potassium hydroxide solution, and the reaction was completed. Later, the mixture was vigorously stirred to produce an adhesive used in the present invention.
[0113]
A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive was used.
[0114]
A pressure-sensitive adhesive tape was prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive was used.
[0115]
The pressure-sensitive adhesive sheet and the pressure-sensitive adhesive tape thus obtained were evaluated as follows, and the results obtained are shown in Tables 1 and 2.
[0116]
(Evaluation test items)
[Adhesive strength] The adhesive strength after storage under the following two conditions was measured in accordance with the method for measuring the normal adhesive strength of JIS-Z-0237. (Unit: N / m)
Condition A: After the production of the pressure-sensitive adhesive sheet and pressure-sensitive adhesive tape, the adhesive strength was measured after being stored for 7 days in an atmosphere having a temperature of 23 ± 2 ° C. and a relative humidity of 65 ± 5%.
Condition B: After producing the pressure-sensitive adhesive sheet and pressure-sensitive adhesive tape, the adhesive strength was measured after storing for 7 days in an atmosphere of a temperature of 40 ± 2 ° C. and a relative humidity of 90 ± 5%.
[0117]
[Cohesive strength] The cohesive strength was measured by a method based on the method for measuring the normal state holding force of JIS-Z-0237, and evaluated according to the following evaluation criteria.
After production of the pressure-sensitive adhesive sheet and pressure-sensitive adhesive tape, the adhesive strength was measured after storing for 7 days in an atmosphere of a temperature of 23 ± 2 ° C. and a relative humidity of 65 ± 5%.
○: The load weight dropped after 5 minutes.
X: The load weight fell within less than 5 minutes.
[0118]
[Adhesive tape box loop] Class A 280 g / m as defined in JIS-P-3902 ² Liner and Class A 125g / m as defined in JIS-P-3904 ² A class A corrugated cardboard having a thickness of 5 mm and having a semi-core is cut into a width of 50 mm and a length of 200 mm in the perpendicular direction, and 50 mm from both ends is compressed from the back surface to obtain a folded test piece.
Two tapes are stacked and sampled and cut in the longitudinal direction to a width of 25 mm and a length of 150 mm. The tape is affixed to the folded corrugated cardboard test piece and crimped by one reciprocation of a 500 g crimping roll. Immediately after crimping, a 25 mm portion is cut from both cardboard end portions so that the area in contact with the cardboard is 25 mm × 50 mm. The tape was left in an atmosphere of 23 ± 2 ° C. and a relative humidity of 65 ± 5% as it was, and tape peeling after one day was evaluated according to the following evaluation criteria.
A: Not peeled off.
○: Not peeled off but misaligned
X: Peel off.
[0119]
[Adhesive Water Redispersibility] The behavior of the adhesive when the adhesive layer surface of the adhesive sheet was rubbed 10 times with a finger while immersed in water at 20 ° C. was evaluated according to the following evaluation criteria.
○: The pressure-sensitive adhesive layer was redispersed into fine fine particles having no tackiness.
(Triangle | delta): Although the adhesiveness of an adhesive layer falls, it does not disperse | distribute finely or aggregates.
X: There was no change in the adhesiveness of the adhesive layer, and the adhesive layer film was agglomerated.
[0120]
[Recyclability] Recyclability after storage under the following two conditions was evaluated.
Condition A: After the production of the pressure-sensitive adhesive sheet and pressure-sensitive adhesive tape, the product was stored for 7 days in an atmosphere at a temperature of 23 ± 2 ° C. and a relative humidity of 65 ± 5%, and then its recyclability was evaluated.
Condition B: After the production of the pressure-sensitive adhesive sheet and pressure-sensitive adhesive tape, it was stored for 7 days in an atmosphere at a temperature of 40 ± 2 ° C. and a relative humidity of 90 ± 5%, and then its recyclability was evaluated.
(Preparation of Evaluation Sample) (1) Pressure-sensitive adhesive sheets of Examples 1 to 7, Comparative Examples 1 to 8, Comparative Example 10, and Comparative Example 11:
Assuming a mailing label to be used by sticking to an envelope, the release sheet is peeled off from the pressure-sensitive adhesive sheet to obtain a pressure-sensitive adhesive label. ² Affixed to high quality paper and used as an evaluation paper fee.
(2) Same adhesive tape:
Assuming the case where it is used by sticking it to a packaging material that can be recycled, a commercially available adhesive tape of 64 g / m ² A sample for evaluation was affixed to high quality paper.
(3) Adhesive sheets of Examples 1 to 7 and Comparative Examples 1 to 11:
The pressure-sensitive adhesive sheet itself was used as a sample for evaluation assuming recycling of used paper in the form of a pressure-sensitive adhesive sheet including a release sheet.
[0121]
(Evaluation)
To 45 g of a sample cut to a size of about 20 mm square, add 1500 ml of water, add 1 g of NaOH, and use a TAPPI standard disintegrator (apparatus described in Appendix A of JIS-P-8220) (3000 rpm). After 30 minutes of treatment, dehydrated with a 60 mesh nylon screen until the pulp concentration reached 15%, 1.5 g of 18% NaOH aqueous solution, deinking agent (trade name: DI-600 / manufactured by Kao Corporation) 10 Add 1.8 g each of the% concentration solution and let stand at 40 ° C. for 20 minutes, then dehydrate with a 60 mesh nylon screen until the pulp concentration is 25%, 30% NaSiO _Three 3.85 g of aqueous solution, 6% strength H ₂ O ₂ Each 5 g of water was added, and then kneading was performed for 5 minutes with a double-arm kneader.
Next, after stirring for 120 minutes while maintaining at 55 ° C., the mixture was diluted with water until the pulp concentration reached 17.5%, and then the second kneading treatment was performed in the same manner. Thereafter, it was further diluted with water until the pulp concentration became 1%. Next, this 1% -concentration pulp dispersion is floated and separated for 10 minutes with a flotator, the foam generated at that time is removed with a scraper, dehydrated with a 60-mesh nylon screen, and washed with 1000 ml of water. Dehydrated to 13% concentration. Water was added to the pulp dispersion thus obtained to a concentration of 0.3% to prepare a handsheet, and the remaining state of undissolved material was visually observed and judged according to the following evaluation criteria.
[0122]
(Recyclability evaluation criteria)
A: There is almost no undissolved material.
○: Slightly undissolved material, but practically no problem.
Δ: Undissolved material is quite noticeable
X: Undissolved material is present, and the undissolved material is sticky.
[0123]
〔Comprehensive evaluation〕
The performance as a recyclable pressure-sensitive adhesive sheet and pressure-sensitive adhesive tape of the present invention was evaluated by combining the above evaluations.
A: In the pressure-sensitive adhesive sheet and pressure-sensitive adhesive tape in which a pressure-sensitive adhesive layer is formed on one surface of the base material, it is possible to recycle waste paper while still in the pressure-sensitive adhesive sheet or attached to the packaging material, and the adhesive performance of the pressure-sensitive adhesive The adhesive strength is less deteriorated by heat and humidity, and the cohesive strength is excellent.
○: In the pressure-sensitive adhesive sheet and pressure-sensitive adhesive tape in which a pressure-sensitive adhesive layer is formed on one surface of the base material, it is possible to recycle waste paper as it is or as it is attached to a packaging material, and the adhesive performance of the pressure-sensitive adhesive However, although the cohesive force is excellent, there is no problem, although there is a slight deterioration in the heat and humidity of the adhesive force.
Δ: Recycled paper can be recycled with the adhesive sheet or attached to the packaging material, but the adhesive performance is poor, such as insufficient cohesive strength of the adhesive or significant deterioration of adhesive strength due to heat and humidity. There is a problem.
X: It is impossible to recycle used paper with the adhesive sheet or attached to the packaging material, regardless of the adhesive performance.
[0124]
[Table 1]

* In the table, recyclability is the result of evaluation in each case of adhesive label / adhesive sheet.
[0125]
[Table 2]

[0126]
【The invention's effect】
As shown in Tables 1 and 2, the pressure-sensitive adhesive sheet and pressure-sensitive adhesive tape of the present invention are excellent in recyclability as waste paper pulp because the pressure-sensitive adhesive is easily re-dispersed in water, and exhibit the necessary adhesive strength when pasted. The pressure-sensitive adhesive sheet and the pressure-sensitive adhesive tape can be easily removed out of the process even if they are attached to a packaging material or the like, or remain in the pressure-sensitive adhesive sheet or are mixed in the recycling process.

Claims (6)

In a pressure-sensitive adhesive sheet in which a pressure-sensitive adhesive layer is provided on a surface substrate and the pressure-sensitive adhesive layer and a release sheet are laminated so as to be peelable, or a pressure-sensitive adhesive tape in which a release agent layer / base material / pressure-sensitive adhesive layer is laminated, It is a base material that can be disaggregated with water or an alkaline aqueous solution, the base material of the release sheet or the base material of the pressure-sensitive adhesive tape to be used is a direct type, and the pressure-sensitive adhesive layer is a pressure-sensitive adhesive having re-disaggregation properties with respect to water. The adhesive is
(A) (meth) acrylic acid alkyl ester monomer having an alkyl group having 4 to 18 carbon atoms: 45-80% by mass, (b) ethylenically unsaturated carboxylic acid-containing monomer: 5-15% by mass, (C) Methyl methacrylate: 1 to 10% by mass, (d) Monomer copolymerizable with a, b, c: 1 to 30% by mass, (poly) alkylene glycol di (meth) In a copolymer obtained by copolymerization in the presence of at least one of acrylate, (poly) alkylene glycol mono (meth) acrylate, (poly) ethylene glycol, and (poly) propylene glycol. A pressure-sensitive adhesive sheet or pressure-sensitive adhesive tape, characterized in that it is a pressure-sensitive adhesive obtained by adding an alkanolamine corresponding to 50 to 120 mol% of the carboxyl group. The addition mole number of alkylene glycol of (poly) alkylene glycol di (meth) acrylate or (poly) alkylene glycol mono (meth) acrylate used at the time of copolymerization of the pressure-sensitive adhesive is 1 to 23. The pressure-sensitive adhesive sheet or pressure-sensitive adhesive tape according to 1. The addition amount of (poly) alkylene glycol di (meth) acrylate or (poly) alkylene glycol mono (meth) acrylate is 0.1 to 5% by mass with respect to the total monomer mixture. The pressure-sensitive adhesive sheet or pressure-sensitive adhesive tape according to any one of 2 above. The pressure-sensitive adhesive sheet or pressure-sensitive adhesive tape according to any one of claims 1 to 3, wherein the (poly) alkylene glycol di (meth) acrylate is polyethylene glycol dimethacrylate. 2. The addition amount of (poly) ethylene glycol and / or (poly) propylene glycol used at the time of copolymerization of the pressure-sensitive adhesive is 0.1 to 15% by mass with respect to the total monomer mixture. The adhesive sheet or adhesive tape of any one of -4. The pressure-sensitive adhesive sheet or pressure-sensitive adhesive tape according to any one of claims 1 to 5, wherein the alkanolamine that neutralizes the carboxyl group in the copolymer has a boiling point of 100 ° C or higher.