JP4780740B2 - Pressure-sensitive adhesive composition with excellent deterioration resistance and information carrying sheet using the same - Google Patents

Description

【００２８】
グラビアコーターによるコーティング時に、接着剤基剤は、微粒状充填剤のシリカゲルや小麦デンプンより速やかに広がるため、塗布された本発明の感圧接着剤組成物の凸状パターンの中心部の組成は、元の接着剤の組成より、微粒状充填剤のシリカゲルや小麦デンプンが多くなる。従って、基体シート面との接着は、凸状パターンの中の接着剤基剤と広がった接着剤基剤によってなされるものと考えられる。
本発明の情報担体用シートの耐ブロッキング性は微粒状充填剤であるシリカゲルや小麦デンプンにより改善されるが、本発明の感圧接着剤組成物の接着層は多数の微細な凸状パターンから形成されているので、均一に塗布されている時より情報担体用シートの耐ブロッキング性はより改善される。また、凸状パターンの中の微粒状充填剤は接着剤基剤で固着され、さらにその凸状パターンは広がった接着剤基剤により基体シート面に接着される。
このようにして、本発明の感圧接着剤組成物が基体シート面上に均一に存在する時よりも、本発明の感圧接着剤組成物の接着層を強固に基体シート面に定着させることができると共に、微粒状充填剤の配合量が少ないこともあり、微粒状充填剤の脱落がなく、印刷適性、プリンター適性、シーラー適性などが大いに改善された情報担体用シートを得ることができるものと考えられる。なお、上記のような優れた特性を有する本発明の情報担体シートが得られる理由はこの考えのみに限定されるものではない。
さらに、形成された剥離可能な接着層を加圧ローラにて加圧することにより、耐ブロッキング性をさらに向上させることができる。
【００２９】
次に、本発明の情報担持用シートの構成について添付図面に基づき詳細に説明する。ここで、図１は本発明の三つ折りハガキの表面展開図、図２はこのハガキの裏面展開図、図３は図１のＸ−Ｘ線断面図、図４は図１のハガキを折り込む際の状態説明図、図５は本発明の二つ折りハガキの表面展開図、図６はこのハガキの裏面展開図、図７は図５のハガキを折り込む際の状態説明図、図８は本発明の部分二つ折りハガキの表面展開図、図９はこのハガキの裏面展開図、図１０は図８のハガキを折り込む際の状態説明図である。
【００３０】
先ず、図１ないし図３に示す三つ折りハガキ１は、定型ハガキサイズの３倍のサイズを有する基体シート２から構成され、折り線３ａ、３ｂによって３つの領域に区画されるものである。左側区画領域Ａの表面には、郵便番号、宛て名、住所等の宛て先情報印刷４が、また中央区画領域Ｂの表裏面及び右側区画領域Ｃの表面には隠蔽情報印刷５が、基体シート２に直接印刷されている。さらに、この印刷された基体シート２の区画領域Ｂ及びＣの表面全体と区画領域Ａ及びＢの裏面全体に対し、本発明の感圧接着剤組成物が塗布されて剥離可能な接着層６が形成されている。このように構成された三つ折りハガキ１は、図４に示すように、各区画の重ね合わせ面を折り線３ａ、３ｂにてＺ型に折り込んで接着層同士を対接させ、この状態でドライシーラーで加圧することにより、その接着層６が活性化されて接着される。
【００３１】
次に、図５及び図６に示す二つ折りハガキ１１は、定型ハガキサイズの２倍のサイズを有する基体シート２から構成され、中央部の折り線３によって２つの領域Ｄ及びＥに区画されるものである。左側区画領域Ｄの表面には、郵便番号、宛て名、住所等の宛て先情報印刷４が、また区画領域Ｄ及びＥの裏面には隠蔽情報印刷５が、基体シート２に直接印刷されている。さらに、この印刷された基体シート２の区画領域Ｄ及びＥの裏面全体に対し、本発明の感圧接着剤組成物が塗布されて剥離可能な接着層６が形成されている。このように構成された二つ折りハガキ１１は、図７に示すように、上記の三つ折りハガキと同様に、左右区画裏面の接着層同士が対接するように折り線３で折り込んで加圧することにより、その接着層６が活性化されて接着される。
【００３２】
また、図８及び図９に示す部分二つ折りハガキ２１は、定型ハガキサイズの１．５倍のサイズを有する基体シート２から構成され、折り線３によってサイズの異なる左右２つの領域Ｆ及びＧに区画されるものである。左側区画領域Ｆの表面には、郵便番号、宛て名、住所等の宛て先情報印刷４が、また右側区画領域Ｇの裏面には隠蔽情報印刷５が、基体シート２に直接印刷されている。さらに、この印刷された基体シート２の区画領域Ｇの裏面全体及び区画領域Ｇを折り線３で折り込んだ際に重ね合わされる区画領域Ｆの一部裏面に対し、本発明の感圧接着剤組成物が塗布されて剥離可能な接着層６が形成されている。このように構成された部分二つ折りハガキ２１は、図１０に示すように、上記の二つ折りハガキと同様に、左右区画裏面の接着層同士が対接するように折り線３で折り込んで加圧することにより、その接着層６が活性化されて接着される。
【００３３】
また、本発明の感圧接着組成物により形成される剥離可能な接着層は、それ自体印刷インキ及びトナーの受容性をも有するため、必要に応じ、さらにその表面に通常の印刷装置あるいはノンインパクトプリンタで付加情報（図示せず）をプリントすることができる。
【００３４】
【実施例】
以下実施例および比較例により本発明を更に詳しく説明するが、本発明はこれら実施例に何ら制約されるものではない。
（実施例１）
Ｔｇ−４５℃のエチレン−酢酸ビニル系ポリマー接着剤基剤（固形分）１００質量部に対し、シリカゲル（日本シリカ工業（株）製、ニップジェルＢＹ−４００、平均粒径４．０μｍあるいは富士シリシア（株）製、サイシリア４４６、平均粒径４．５μｍ）１５質量部、スターチ１５質量部配合して本発明の感圧接着剤組成物を調製した。
この本発明の感圧接着剤組成物を連量７０ｋｇの上質紙にグラビアオフセット方式により１０ｇ／ｍ² の割合で塗布し、接着層を形成し、次いで、１２０℃、３０秒間加熱を行い乾燥処理した。
このようにして作った情報担持用シートの製造直後の９０°剥離（Ｔ型剥離）接着力、耐酸化劣化性能、耐熱性能、耐ＵＶ性能を下記の方法により評価し、評価結果を表２に示す。
【００３５】
（１）９０°剥離（Ｔ型剥離）接着力の測定方法：
得られた情報担持用シートを、幅２５ｍｍ、長さ１００ｍｍに裁断して試料を作成し、この試料２枚を２５ｍｍの長さで重ね合わせ７ＭＰａの荷重を加えて圧着した。接着剤の剥離接着強さ試験方法ＪＩＳＫ６８５４に準じて、オートグラフＡＧＳ５０（島津製作所製）を用いて９０°剥離（Ｔ型剥離）接着力を測定する。
◎：優、○：良、△：可、×：不可
◎：１００〜１５０（ｇｆ／２５ｍｍ）
○：１５０〜２００（ｇｆ／２５ｍｍ）あるいは
５０〜１００（ｇｆ／２５ｍｍ）
△：２００〜３００（ｇｆ／２５ｍｍ）あるいは
３０〜 ５０（ｇｆ／２５ｍｍ）
×：３００（ｇｆ／２５ｍｍ）以上あるいは
３０（ｇｆ／２５ｍｍ）以下
【００３６】
（２）耐酸化劣化性能：
得られた情報担持用シートを、ヤマト科学製の送風定温器中に入れて、４０℃で２４時間放置した後に上記のようにして９０°剥離（Ｔ型剥離）接着力を測定する。
◎：優、○：良、△：可、×：不可
◎：９０°剥離接着力が８０〜１００％保持されている。
○：９０°剥離接着力が６０〜８０％保持されている。
△：９０°剥離接着力が４０〜６０％しか保持されていない。
×：９０°剥離接着力が４０％以下になった。
【００３７】
（３）耐熱性能：
得られた情報担持用シートを、１４０℃のステンレス板に挟み、３０分放置した後に上記のようにして９０°剥離（Ｔ型剥離）接着力を測定する。
◎：優、○：良、△：可、×：不可
◎：９０°剥離接着力が８０〜１００％保持されている。
○：９０°剥離接着力が６０〜８０％保持されている。
△：９０°剥離接着力が４０〜６０％しか保持されていない。
×：９０°剥離接着力が４０％以下になった。
【００３８】
（４）耐ＵＶ性能：
得られた情報担持用シートを、アイグラフィックス製メタルハライドランプを使用して、５７ｍＪ／ｃｍ² の紫外線（ＵＶ）を照射した後に上記のようにして９０°剥離（Ｔ型剥離）接着力を測定する。
◎：優、○：良、△：可、×：不可
◎：９０°剥離接着力が８０〜１００％保持されている。
○：９０°剥離接着力が６０〜８０％保持されている。
△：９０°剥離接着力が４０〜６０％しか保持されていない。
×：９０°剥離接着力が４０％以下になった。
【００３９】
（実施例２〜３）
表２に示した各成分の配合割合とした以外は、実施例１と同様にして本発明の感圧接着剤組成物を調製し、実施例１と同様にして得た情報担持用シートの９０°剥離接着力、耐酸化劣化性能、耐熱性能、耐ＵＶ性能を評価した結果を表２に示す。
【００４０】
（実施例４〜６）
Ｔｇ−３５℃のエチレン−酢酸ビニル系ポリマー接着剤基剤を用い表２に示した各成分の配合割合とした以外は、実施例１〜３と同様にして本発明の感圧接着剤組成物を調製し、実施例１〜３と同様にして得た情報担持用シートの９０°剥離接着力、耐酸化劣化性能、耐熱性能、耐ＵＶ性能を評価した結果を表２に示す。
【００４１】
（実施例７〜９）
Ｔｇ−２５℃のエチレン−酢酸ビニル系ポリマー接着剤基剤を用い表２に示した各成分の配合割合とした以外は、実施例１〜３と同様にして本発明の感圧接着剤組成物を調製し、実施例１〜３と同様にして得た情報担持用シートの９０°剥離接着力、耐酸化劣化性能、耐熱性能、耐ＵＶ性能を評価した結果を表２に示す。
【００４２】
（比較例１）
天然ゴム（ＮＲ）１００質量部とＭＭＡ２５重量部とを混合してグラフト共重合して得たＭＭＡグラフト共重合天然ゴムエマルジョン１００質量部（固形分）に対して、スチレンリッチＳＢＲラテックス（ニポール２５０７Ｈ、日本ゼオン（株））を固形分が２０質量部となるように配合した接着剤基剤を用いた以外は、実施例１〜３と同様にして比較のための感圧接着剤組成物を調製し、実施例１〜３と同様にして得た情報担持用シートの９０°剥離接着力、耐酸化劣化性能、耐熱性能、耐ＵＶ性能を評価した結果を表３に示す。
【００４３】
（比較例２〜３）
表３に示した配合とした以外は比較例１と同様にして、比較のための感圧接着剤組成物を調製し、実施例１〜３と同様にして得た情報担持用シートの９０°剥離接着力、耐酸化劣化性能、耐熱性能、耐ＵＶ性能を評価した結果を表３に示す。
【００４４】
（比較例４〜６）
スチレンリッチＳＢＲラテックスの替わりにポリスチレンエマルジョン（ニポールＬＸ３０３、日本ゼオン（株））を用いた以外は、比較例１と同様にして比較のための感圧接着剤組成物を調製し、実施例１〜３と同様にして得た情報担持用シートの９０°剥離接着力、耐酸化劣化性能、耐熱性能、耐ＵＶ性能を評価した結果を表３に示す。
【００４５】
（比較例７〜９）
Ｔｇ−２０℃のエチレン−酢酸ビニル系ポリマー接着剤基剤を用い表４に示した各成分の配合割合とした以外は、実施例１〜３と同様にして比較のための感圧接着剤組成物を調製し、実施例１〜３と同様にして得た情報担持用シートの９０°剥離接着力、耐酸化劣化性能、耐熱性能、耐ＵＶ性能を評価した結果を表４に示す。
【００４６】
（比較例１０〜１２）
Ｔｇ−５０℃のエチレン−酢酸ビニル系ポリマー接着剤基剤を用い表４に示した各成分の配合割合とした以外は、実施例１〜３と同様にして比較のための感圧接着剤組成物を調製し、実施例１〜３と同様にして得た情報担持用シートの９０°剥離接着力、耐酸化劣化性能、耐熱性能、耐ＵＶ性能を評価した結果を表４に示す。
【００４７】
【表２】

【００４８】
【表３】

【００４９】
【表４】

【００５０】
表２から、実施例１〜９の本発明の感圧接着剤組成物は９０°剥離接着力、耐酸化劣化性能、耐熱性能、耐ＵＶ性能がいずれも優れていることが判る。
表３から、比較例１〜６の比較の感圧接着剤組成物は９０°剥離接着力はよいが、耐酸化劣化性能、耐熱性能、耐ＵＶ性能がいずれも劣ることが判る。
表４から、比較例７〜１２の比較の感圧接着剤組成物はいずれも特に９０°剥離接着力が劣ることが判る。
【００５１】
【発明の効果】
本発明の請求項１記載の感圧接着剤組成物は、Ｔｇが−２５〜−４５℃のエチレン−酢酸ビニル系ポリマー接着剤基剤と、この接着剤基剤固形分１００質量部に対し、平均粒子径が０．１〜２０μｍの微粒状充填剤を特定量配合したので、耐酸化劣化性能、耐熱性能、耐ＵＶ性能、耐ブロッキング性能に優れ、空気中に放置されたり、加熱されたり、紫外線（ＵＶ）を照射されたりしても接着力が低下しないという顕著な効果を奏する。
【００５３】
請求項２記載の情報担持用シートは、基体シートの重ね合わせ面の全面にあるいは隠蔽情報担持面にあるいは線状に請求項１記載の感圧接着剤組成物を例えばグラビアコーターにより塗布し、乾燥処理により通常状態では接着しない微細な多数の凸状パターンからなる接着層を形成し、重ね合わせ面同士を対接させた状態で強圧をかけ密着させて接着すると十分な接着力が得られるとともに、必要に応じて剥離する際は容易に剥離できるという効果を奏する。
また、請求項２記載の情報担持用シートは、耐酸化劣化性能、耐熱性能、耐ＵＶ性能に優れ、加熱されたり、紫外線（ＵＶ）を照射されたりしても接着力が低下しないという顕著な効果を奏する。
【図面の簡単な説明】
【図１】本発明の三つ折りハガキの表面展開図。
【図２】図１のハガキの裏面展開図。
【図３】図１のＸ−Ｘ線断面図。
【図４】図１のハガキを折り込む際の状態説明図。
【図５】本発明の二つ折りハガキの表面展開図。
【図６】図５のハガキの裏面展開図。
【図７】図５のハガキを折り込む際の状態説明図。
【図８】本発明の部分二つ折りハガキの表面展開図。
【図９】図８のハガキの裏面展開図。
【図１０】図８のハガキを折り込む際の状態説明図。
【符号の説明】
２、１２、２２ 基体シート
３、３ａ、３ｂ 折り線
５ 隠蔽情報印刷
６ 剥離可能な接着層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pressure-sensitive adhesive composition excellent in deterioration resistance and an information carrying sheet using the same, and more specifically, a folded sheet in which a surface overlapped by folding or cutting is used as an information carrying surface, Information transfer sheets such as superposed sheets that have confidentiality, arrangement sheets that can be expanded in size, and information transmission sheets such as office sheets such as copy paper, and pressure resistance with excellent deterioration resistance used for these sheets. The present invention relates to an adhesive composition.
[0002]
[Prior art]
Conventionally, in an information carrying sheet that carries information on an overlapping surface, the entire overlapping surface or a specific portion is usually formed in a pattern that comes into contact with the overlapping surface so that the overlapping surfaces adhere to each other. Alternatively, an adhesive layer of a pressure-sensitive adhesive is provided linearly. This pressure-sensitive adhesive is also called a self-adhesive pressure-sensitive adhesive, and is a type in which each polymer adheres by self-diffusion by applying a strong pressure in a state where the adhesive layers are in contact with each other. Depending on the type of object and the degree of pressurization, permanent adhesiveness and re-peeling adhesiveness are realized.
[0003]
Conventionally, the main component of a pressure-sensitive adhesive used in this type of information carrying sheet generally includes a methyl methacrylate graft copolymer natural rubber pressure-sensitive adhesive as a main component. However, the pressure sensitive adhesive containing methyl methacrylate graft copolymer natural rubber pressure sensitive adhesive as the main component is inferior in oxidation resistance deterioration performance, heat resistance performance and UV resistance performance of the adhesive layer, and is left in the air or heated. When it is applied or irradiated with ultraviolet rays (UV), there is a problem that the 90 ° peel adhesive strength decreases.
[0004]
That is, the conventional information carrying sheet deteriorates when it is left in the air, heated, or irradiated with ultraviolet rays (UV), and the 90 ° peel adhesive strength is reduced. Confidential information that should not be touched by third parties during mailing due to the pressure-sensitive adhesive part of the information-carrying sheet, such as postcards, that has been mailed while the confidential information is concealed. There is a problem that the information is exposed to the eyes of a third party and the original function as a confidential information carrying sheet is not performed.
[0005]
The first object of the present invention is to provide a pressure-sensitive adhesive composition that solves the conventional problems and is excellent in resistance to oxidation deterioration, heat resistance, UV resistance, and blocking resistance. A second object is to provide an information carrying sheet using such a pressure-sensitive adhesive composition having excellent deterioration resistance.
[0006]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventors have made an ethylene-vinyl acetate polymer adhesive base, in particular, an ethylene-vinyl acetate polymer adhesive base having a specific Tg, and this adhesive. By using a pressure-sensitive adhesive composition that contains a specific amount of fine filler such as starch and silica gel to the base, it has excellent resistance to oxidation degradation, heat resistance, UV resistance, and blocking resistance. The present inventors have found that an adhesive composition can be provided and an inexpensive information carrying sheet excellent in deterioration resistance can be provided, and the present invention has been completed.
[0007]
That is, the pressure-sensitive adhesive composition having excellent deterioration resistance according to claim 1 of the present invention is applied to the overlapping surface of the sheet, and forms an adhesive layer that does not adhere in a normal state by a drying process. A pressure-sensitive adhesive that adheres the overlapping surfaces so that they can be peeled off by bringing the surfaces into contact with each other and applying a predetermined pressure,
Tg is −25 to −45 ° C. For ethylene-vinyl acetate polymer adhesive base and 100 parts by mass of this adhesive base solid content, The average particle size is 0.1-20 μm It is characterized by blending fine particulate filler in a proportion of 30 to 100 parts by mass.
[0009]
Claims of the invention 2 The information-carrying sheet described above is an Claim 1 on the entire surface, on the concealed information carrying surface or in a linear form It is characterized by having an adhesive layer composed of a large number of fine convex patterns of a pressure-sensitive adhesive composition having excellent deterioration resistance.
[0010]
According to the pressure-sensitive adhesive composition of claim 1 and claim 2 of the present invention, an ethylene-vinyl acetate polymer adhesive is used as a base, and an ethylene-vinyl acetate polymer having a specific Tg is used as a base. As a pressure-sensitive adhesive composition containing a specific amount of fine particulate filler to this adhesive base, it is excellent in oxidation resistance, heat resistance, UV resistance, and blocking resistance. After applying to the overlapping surface of the sheet, forming an adhesive layer that does not adhere in the normal state by drying treatment, and applying strong pressure in the state where the overlapping surfaces are in contact with each other, and then bonding them as necessary Can be easily peeled off.
[0011]
Claim 2 The information-carrying sheet described above is an On the entire surface, on the concealed information carrying surface, or in a line The pressure-sensitive adhesive composition according to claim 1 is applied by, for example, a gravure coater, and an adhesive layer composed of a number of fine convex patterns that do not adhere in a normal state is formed by a drying process, and the overlapping surfaces are brought into contact with each other. In this state, a sufficient pressure can be obtained by applying a strong pressure to bring it into close contact with each other, and when necessary, it can be easily peeled off.
Claim 2 The information-carrying sheet described above has a 90 ° peel adhesive strength that does not deteriorate even when the adhesive layer is left in the air, heated, or irradiated with ultraviolet rays (UV), and is thus resistant to deterioration. Are better.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
The pressure-sensitive adhesive composition of the present invention forms an adhesive layer that does not adhere in a normal state, adheres by pressurization, and can be peeled off when necessary, and is an ethylene-vinyl acetate polymer adhesive 30 to 100 parts by mass of fine particulate filler is blended with 100 parts by mass of the base and the adhesive base solid content.
[0013]
In the pressure-sensitive adhesive composition of the present invention, it is important to use an ethylene-vinyl acetate polymer adhesive as a base. Use of ethylene-vinyl acetate polymer adhesive as a base improves oxidation resistance, heat resistance, and UV resistance, allowing it to be left in the air, heated, or irradiated with ultraviolet rays (UV). However, the 90 ° peel adhesion does not decrease.
In the pressure-sensitive adhesive composition of the present invention, it is preferable to use an ethylene-vinyl acetate polymer adhesive base having a Tg of −25 to −45 ° C. If Tg is higher than −25 ° C., 90 ° peel adhesive strength may not fall within the preferred range, and if Tg is lower than −45 ° C., 90 ° peel adhesive strength may still fall outside the preferred range.
[0014]
The ethylene-vinyl acetate polymer having a Tg of −25 ° C. to −45 ° C. used in the pressure-sensitive adhesive composition of the present invention can be obtained, for example, by copolymerizing an ethylene monomer and a vinyl acetate monomer. The standard of Tg of the ethylene-vinyl acetate polymer obtained by copolymerization is calculated by the following formula (1).
1 / Tg = W1 / Tg1 + W2 / Tg2 + ... + Wn / Tgn Equation (1)
In equation (1)
Tg: Tg (° K) of the obtained ethylene-vinyl acetate polymer
W1: Mass fraction of ethylene monomer
W2: Mass fraction of vinyl acetate monomer
Wn: mass fraction of other monomers to be copolymerized
Tg1: Tg of ethylene homopolymer (° K) (Tg of ethylene homopolymer is −125 ° C.)
Tg2: Tg of vinyl acetate homopolymer (° K) (Tg of vinyl acetate homopolymer is 28 ° C)
Tgn: Tg of homopolymer of other monomers (° K)
[0015]
For example, when an ethylene monomer and a vinyl acetate monomer are copolymerized to obtain an ethylene-vinyl acetate polymer, ethylene-acetic acid having a Tg of −25 ° C. to −45 ° C. used in the present invention by changing the copolymerization amount of ethylene. Vinyl polymer adhesives can be obtained.
Other monomers that copolymerize with ethylene monomer and vinyl acetate monomer can be copolymerized, and it is possible to obtain an ethylene-vinyl acetate polymer adhesive having a Tg in the range of -25 ° C to -45 ° C. If it does not specifically limit. Examples of other monomers include the following monomers. The numbers described in each indicate the Tg (° C.) of the homopolymer obtained by polymerizing the monomer.
[0016]
monomer;
Methyl methacrylate (105), ethyl methacrylate (47-65), n-butyl methacrylate (20-22), isobutyl methacrylate (48), t-butyl methacrylate (107), acrylonitrile (105), methacrylic acid 2-ethylhexyl (-10), lauryl methacrylate (-65), methyl acrylate (8-9), ethyl acrylate (-22), n-butyl acrylate (-54--56), isobutyl acrylate ( -30), 2-ethylhexyl acrylate (-55 to -70), octadecyl methacrylate (-100), and the like.
[0017]
The (co) polymerization method is not particularly limited. For example, all the emulsifier and water, or if necessary, some monomers and a polymerization initiator are charged into the reactor. A monomer addition method, which is a polymerization method to be added later, an emulsion addition method, which is a polymerization method in which a part of a polymerization compound is first emulsified and polymerized, and the rest is emulsified and added as an emulsion sequentially during the polymerization. Combinations can be mentioned.
[0018]
The adhesive base composed of the ethylene-vinyl acetate polymer adhesive thus obtained includes a tackifier (terpene phenol resin, polybutene resin, It is preferable to add 10 to 30 parts by mass of rosin ester resin, petroleum resin or the like.
[0019]
For the adhesive base composed of an ethylene-vinyl acetate polymer adhesive, other additives commonly used for pressure-sensitive adhesives, for example, dispersants, viscosity modifiers, fluidity improvers, antifoaming agents, are optionally used. , Mold release agent, foaming agent, penetrating agent, coloring dye, coloring pigment, fluorescent whitening agent, UV absorber, antioxidant, antiseptic, antibacterial agent, water resistant agent, wet paper strength enhancer, dry paper strength An enhancer, an antistatic agent, an antiaging agent, and the like can be appropriately added.
[0020]
In the pressure-sensitive adhesive composition of the present invention, a particulate filler is blended with the adhesive base. As the fine particulate filler, it is preferable to use a filler which has no or very little affinity with the adhesive base and is difficult to dissolve in the adhesive base.
[0021]
Examples of such materials include various types of starch, silica, synthetic zeolite, fine spherical acrylic resin, fine spherical methacrylic resin, fine spherical polyethylene, spherical alumina, glass powder, shirasu balloon, activated clay, and the like.
These fine particulate fillers may be used alone or in combination of two or more. These fine particulate fillers have an average particle diameter of 0.1 to 20 μm, preferably 0.5 to 10 μm.
[0022]
In the pressure-sensitive adhesive composition of the present invention, the fine particulate filler is 30 to 100 parts by mass, preferably 40 to 100 parts by mass, more preferably 50 to 100 parts by mass of the adhesive base (solid content). It mix | blends in 100 mass parts. If the blending amount of the fine particulate filler is less than 30 parts by mass, the anti-blocking performance is lowered, or the adhesive strength is too strong to be peeled off, and if it exceeds 100 parts by mass, Adhesive strength becomes too low and sufficient tackiness is not exhibited.
[0023]
The pressure-sensitive adhesive composition of the present invention is applied to the substrate sheet surface by a coating means such as a gravure coater, flexo, air knife coater, bar coater, etc., folded in half, folded in three, cut up, or stacked together. It can be suitably used for postcards having various facing surfaces, various forms, notices, various cards, and the like, which are temporarily bonded in various overlapping forms but can be easily peeled off as necessary.
[0024]
Next, as the base sheet to which the pressure-sensitive adhesive composition of the present invention is applied, synthetic paper or synthetic films such as polyethylene, polyethylene terephthalate, polypropylene, and vinyl chloride can be used in addition to ordinary paper. . When these synthetic films are used, the surface of the base sheet is preferably subjected to surface treatment such as mat treatment or corona treatment. Moreover, the application amount of the pressure-sensitive adhesive composition to the base sheet surface is 1 to 30 g / m for the adhesiveness and peelability of the adhesive layer. ² , Preferably 3-20 g / m ² , More preferably 5 to 15 g / m ² It is good to do.
[0025]
In the information carrier sheet of the present invention, it is important that an adhesive layer comprising a number of fine convex patterns made of the pressure-sensitive adhesive composition of the present invention is provided on at least a part of the base sheet surface. .
The method of providing an adhesive layer composed of a number of fine convex patterns of the pressure-sensitive adhesive composition of the present invention on the substrate sheet surface is not particularly limited, but the application method with a gravure coater is economical, It has the strong fixability to paper and the cohesive strength of the adhesive film, and it is the most easy to give the information carrier sheet the characteristics that the adhesive wears and does not fall off while running on a printing press or printer. This is the preferred method.
When coating with an air knife coater, the surface of the adhesive layer becomes uniform, so it is necessary to add more than 100 parts by weight of a fine filler to 100 parts by weight of the adhesive base. According to the coating method, the fine particulate filler can be 30 to 100 parts by mass.
[0026]
This is because when coated with an air knife coater, the fine particulate filler is applied evenly and evenly on the substrate sheet surface, but the gravure coater is applied to the substrate sheet surface with a concave pattern of the mesh of the engraving roll, The adhesive layer which consists of many fine convex patterns of the pressure sensitive adhesive composition of this invention by one application | coating can be provided. As shown in Table 1, the concave pattern of the mesh of the engraving roll is a pyramid shape having different mountain width (a), mountain-to-mountain width (b), valley width (c), and mountain height (d). There is a lattice type or the like, and the pressure-sensitive adhesive composition is held in these recesses. Usually, a gravure offset method is employed in which the pressure sensitive adhesive composition is once transferred from the engraving roll to the transfer roll (print roll) and then applied to the base sheet.
The size and shape of the fine convex pattern of the adhesive layer of the pressure-sensitive adhesive composition of the present invention provided on the base sheet surface are different depending on the size and shape of the concave pattern of the mesh. In addition, since the pressure sensitive adhesive composition of this invention spreads at the time of the coating by a gravure coater, of course, the fine convex pattern as it is of the magnitude | size and shape of the concave pattern of the said mesh is not formed.
[0027]
[Table 1]

[0028]
At the time of coating with a gravure coater, the adhesive base spreads more quickly than silica gel or wheat starch as a fine filler, so the composition of the central part of the convex pattern of the applied pressure-sensitive adhesive composition of the present invention is: More silica gel and wheat starch as fine particulate fillers than the original adhesive composition. Therefore, it is considered that the adhesion to the base sheet surface is performed by the adhesive base in the convex pattern and the spread adhesive base.
Although the blocking resistance of the information carrier sheet of the present invention is improved by silica gel or wheat starch which are finely divided fillers, the adhesive layer of the pressure-sensitive adhesive composition of the present invention is formed from a number of fine convex patterns. Therefore, the blocking resistance of the information carrier sheet is more improved than when it is uniformly applied. Further, the fine particulate filler in the convex pattern is fixed with an adhesive base, and the convex pattern is further adhered to the base sheet surface with the spread adhesive base.
In this way, the adhesive layer of the pressure-sensitive adhesive composition of the present invention is firmly fixed to the substrate sheet surface, compared to when the pressure-sensitive adhesive composition of the present invention is uniformly present on the substrate sheet surface. In addition, the amount of the fine particle filler may be small, and the fine particle filler is not dropped off, and an information carrier sheet with greatly improved printability, printer suitability, sealer suitability, etc. can be obtained. it is conceivable that. The reason why the information carrier sheet of the present invention having the excellent characteristics as described above is obtained is not limited to this idea.
Furthermore, blocking resistance can be further improved by pressing the formed peelable adhesive layer with a pressure roller.
[0029]
Next, the structure of the information carrying sheet of the present invention will be described in detail with reference to the accompanying drawings. Here, FIG. 1 is a developed front view of a tri-fold postcard of the present invention, FIG. 2 is a developed rear view of the postcard, FIG. 3 is a cross-sectional view taken along the line XX of FIG. FIG. 5 is a developed front view of the folded bi-fold postcard of the present invention, FIG. 6 is a developed rear view of the postcard, FIG. 7 is an explanatory diagram of the state of folding the postcard of FIG. 5, and FIG. FIG. 9 is a developed front view of a partially folded postcard, FIG. 9 is a developed rear view of the postcard, and FIG. 10 is an explanatory view of a state when the postcard of FIG. 8 is folded.
[0030]
First, the tri-fold postcard 1 shown in FIGS. 1 to 3 is composed of a base sheet 2 having a size three times the standard postcard size, and is divided into three regions by folding lines 3a and 3b. Destination information printing 4 such as a zip code, address, address, etc. is provided on the front surface of the left partition area A, and concealment information printing 5 is provided on the front and back surfaces of the central partition area B and the front surface of the right partition area C. 2 is printed directly. Furthermore, the adhesive layer 6 that can be peeled off by applying the pressure-sensitive adhesive composition of the present invention to the entire surface of the partition regions B and C and the entire back surface of the partition regions A and B of the printed substrate sheet 2 is provided. Is formed. As shown in FIG. 4, the tri-fold postcard 1 configured in this way is formed by folding the overlapping surface of each section into a Z shape at the fold lines 3a and 3b to bring the adhesive layers into contact with each other. By applying pressure with a sealer, the adhesive layer 6 is activated and bonded.
[0031]
Next, the bi-fold postcard 11 shown in FIGS. 5 and 6 is composed of a base sheet 2 having a size twice as large as the standard postcard size, and is divided into two regions D and E by a fold line 3 at the center. Is. A destination information print 4 such as a postal code, an address, and an address is printed on the front surface of the left partition area D, and a concealment information print 5 is printed directly on the base sheet 2 on the back surfaces of the partition areas D and E. . Furthermore, the pressure-sensitive adhesive composition of the present invention is applied to the entire back surface of the partition regions D and E of the printed base sheet 2 to form a peelable adhesive layer 6. As shown in FIG. 7, the bi-fold postcard 11 configured in this way is folded and pressed at the fold line 3 so that the adhesive layers on the back surfaces of the left and right compartments are in contact with each other as in the case of the above-described tri-fold postcard. The adhesive layer 6 is activated and bonded.
[0032]
Further, the partially folded postcard 21 shown in FIGS. 8 and 9 is composed of a base sheet 2 having a size 1.5 times the standard postcard size, and is divided into two left and right regions F and G having different sizes depending on the folding line 3. It is to be partitioned. A destination information print 4 such as a postal code, a destination name, and an address is directly printed on the front surface of the left partition region F, and a concealment information print 5 is directly printed on the base sheet 2 on the back surface of the right partition region G. Further, the pressure-sensitive adhesive composition of the present invention is applied to the entire back surface of the partition region G of the printed base sheet 2 and a partial back surface of the partition region F that is overlapped when the partition region G is folded at the folding line 3. A peelable adhesive layer 6 is formed by applying an object. As shown in FIG. 10, the partially folded postcard 21 configured in this way is folded and pressed at the folding line 3 so that the adhesive layers on the back surfaces of the left and right compartments are in contact with each other, as in the case of the above-described bifolded postcard. Thus, the adhesive layer 6 is activated and bonded.
[0033]
In addition, the peelable adhesive layer formed by the pressure-sensitive adhesive composition of the present invention itself has the acceptability of printing ink and toner, and therefore, if necessary, a normal printing device or non-impact on the surface thereof. Additional information (not shown) can be printed by a printer.
[0034]
【Example】
Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.
Example 1
For 100 parts by mass of an ethylene-vinyl acetate polymer adhesive base (solid content) of Tg-45 ° C., silica gel (Nippon Silica Kogyo Co., Ltd., Nipgel BY-400, average particle size 4.0 μm or Fuji Silysia ( The pressure-sensitive adhesive composition of the present invention was prepared by blending 15 parts by mass of Cicilia 446, average particle size 4.5 μm) and 15 parts by mass of starch.
The pressure-sensitive adhesive composition of the present invention is applied to a high-quality paper having a continuous weight of 70 kg by a gravure offset method at 10 g / m ² Then, an adhesive layer was formed, followed by drying at 120 ° C. for 30 seconds.
The 90 ° peeling (T-type peeling) adhesive strength, oxidation deterioration resistance, heat resistance, and UV resistance immediately after production of the information carrying sheet thus prepared were evaluated by the following methods, and the evaluation results are shown in Table 2. Show.
[0035]
(1) Method for measuring 90 ° peeling (T-type peeling) adhesive strength:
The obtained information carrying sheet was cut into a width of 25 mm and a length of 100 mm to prepare a sample, and the two samples were overlapped with a length of 25 mm, and a load of 7 MPa was applied thereto, followed by pressure bonding. The 90 ° peel (T-type peel) adhesive strength is measured using an autograph AGS50 (manufactured by Shimadzu Corporation) in accordance with the peel adhesion strength test method JISK6854.
◎: Excellent, ○: Good, △: Acceptable, ×: Impossible
A: 100 to 150 (gf / 25 mm)
○: 150 to 200 (gf / 25 mm) or
50-100 (gf / 25mm)
Δ: 200 to 300 (gf / 25 mm) or
30-50 (gf / 25mm)
X: 300 (gf / 25 mm) or more or
30 (gf / 25mm) or less
[0036]
(2) Oxidation degradation performance:
The obtained information carrying sheet is placed in a blast incubator manufactured by Yamato Scientific and allowed to stand at 40 ° C. for 24 hours, and then the 90 ° peel (T-type peel) adhesive force is measured as described above.
◎: Excellent, ○: Good, △: Acceptable, ×: Impossible
A: 90 ° peel adhesion is maintained at 80 to 100%.
A: 90 ° peel adhesion is maintained at 60 to 80%.
Δ: 90 ° peel adhesion is only 40-60%.
X: 90 ° peel adhesion was 40% or less.
[0037]
(3) Heat resistance performance:
The obtained information carrying sheet is sandwiched between 140 ° C. stainless steel plates and allowed to stand for 30 minutes, and then the 90 ° peel (T-type peel) adhesive force is measured as described above.
◎: Excellent, ○: Good, △: Acceptable, ×: Impossible
A: 90 ° peel adhesion is maintained at 80 to 100%.
A: 90 ° peel adhesion is maintained at 60 to 80%.
Δ: 90 ° peel adhesion is only 40-60%.
X: 90 ° peel adhesion was 40% or less.
[0038]
(4) UV resistance:
The obtained information carrying sheet was 57 mJ / cm using an eye graphics metal halide lamp. ² After irradiating the ultraviolet ray (UV), 90 ° peel (T-type peel) adhesion is measured as described above.
◎: Excellent, ○: Good, △: Acceptable, ×: Impossible
A: 90 ° peel adhesion is maintained at 80 to 100%.
A: 90 ° peel adhesion is maintained at 60 to 80%.
Δ: 90 ° peel adhesion is only 40-60%.
X: 90 ° peel adhesion was 40% or less.
[0039]
(Examples 2-3)
A pressure-sensitive adhesive composition of the present invention was prepared in the same manner as in Example 1 except that the mixing ratio of each component shown in Table 2 was used. Table 2 shows the results of evaluating peel adhesion, oxidation degradation resistance, heat resistance, and UV resistance.
[0040]
(Examples 4 to 6)
The pressure-sensitive adhesive composition of the present invention was carried out in the same manner as in Examples 1 to 3, except that an ethylene-vinyl acetate polymer adhesive base having a Tg of 35 ° C. was used and the mixing ratio of each component shown in Table 2 was used. Table 2 shows the results of evaluating the 90 ° peel adhesion, oxidation degradation resistance, heat resistance, and UV resistance of the information carrying sheets obtained in the same manner as in Examples 1 to 3.
[0041]
(Examples 7 to 9)
The pressure-sensitive adhesive composition of the present invention was carried out in the same manner as in Examples 1 to 3, except that an ethylene-vinyl acetate polymer adhesive base with a Tg of 25 ° C. was used and the mixing ratio of each component shown in Table 2 was used. Table 2 shows the results of evaluating the 90 ° peel adhesion, oxidation degradation resistance, heat resistance, and UV resistance of the information carrying sheets obtained in the same manner as in Examples 1 to 3.
[0042]
(Comparative Example 1)
100 parts by mass of MMA graft copolymer natural rubber emulsion (solid content) obtained by mixing 100 parts by mass of natural rubber (NR) and 25 parts by mass of MMA and then copolymerizing the styrene-rich SBR latex (Nipol 2507H, A pressure-sensitive adhesive composition for comparison was prepared in the same manner as in Examples 1 to 3, except that an adhesive base formulated with Nippon Zeon Co., Ltd.) so that the solid content was 20 parts by mass was used. Table 3 shows the results of evaluating the 90 ° peel adhesion, oxidation degradation resistance, heat resistance, and UV resistance of the information carrying sheets obtained in the same manner as in Examples 1 to 3.
[0043]
(Comparative Examples 2-3)
A pressure-sensitive adhesive composition for comparison was prepared in the same manner as in Comparative Example 1 except that the formulation shown in Table 3 was used, and 90 ° of the information carrying sheet obtained in the same manner as in Examples 1 to 3 was used. Table 3 shows the results of evaluation of peel adhesion, oxidation degradation resistance, heat resistance, and UV resistance.
[0044]
(Comparative Examples 4-6)
A pressure-sensitive adhesive composition for comparison was prepared in the same manner as in Comparative Example 1 except that a polystyrene emulsion (Nipol LX303, Nippon Zeon Co., Ltd.) was used instead of the styrene-rich SBR latex. Table 3 shows the results of evaluating the 90 ° peel adhesion, oxidation degradation resistance, heat resistance, and UV resistance of the information carrying sheet obtained in the same manner as in Table 3.
[0045]
(Comparative Examples 7-9)
A pressure-sensitive adhesive composition for comparison in the same manner as in Examples 1 to 3, except that an ethylene-vinyl acetate polymer adhesive base at Tg-20 ° C. was used and the blending ratio of each component shown in Table 4 was used. Table 4 shows the results of evaluating the 90 ° peel adhesion, oxidation deterioration resistance, heat resistance, and UV resistance of the information carrying sheets prepared in the same manner as in Examples 1 to 3.
[0046]
(Comparative Examples 10-12)
A pressure-sensitive adhesive composition for comparison in the same manner as in Examples 1 to 3 except that an ethylene-vinyl acetate polymer adhesive base with a Tg of 50 ° C. was used and the mixing ratio of each component shown in Table 4 was used. Table 4 shows the results of evaluating the 90 ° peel adhesion, oxidation deterioration resistance, heat resistance, and UV resistance of the information carrying sheets prepared in the same manner as in Examples 1 to 3.
[0047]
[Table 2]

[0048]
[Table 3]

[0049]
[Table 4]

[0050]
From Table 2, it can be seen that the pressure-sensitive adhesive compositions of the present invention of Examples 1 to 9 are all excellent in 90 ° peel adhesive strength, oxidation degradation performance, heat resistance performance, and UV resistance performance.
From Table 3, it can be seen that the comparative pressure-sensitive adhesive compositions of Comparative Examples 1 to 6 have good 90 ° peel adhesion, but are inferior in oxidation resistance degradation performance, heat resistance performance, and UV resistance performance.
From Table 4, it can be seen that the comparative pressure-sensitive adhesive compositions of Comparative Examples 7 to 12 are particularly inferior in 90 ° peel adhesion.
[0051]
【The invention's effect】
The pressure-sensitive adhesive composition according to claim 1 of the present invention is Tg is −25 to −45 ° C. For ethylene-vinyl acetate polymer adhesive base and 100 parts by mass of this adhesive base solid content, The average particle size is 0.1-20 μm Because it contains a specific amount of fine particulate filler, it has excellent resistance to oxidative degradation, heat resistance, UV resistance, and blocking resistance. It can be left in the air, heated, or irradiated with ultraviolet rays (UV). Also has a remarkable effect that the adhesive strength does not decrease.
[0053]
Claim 2 The information-carrying sheet mounted on the overlapping surface of the base sheet On the entire surface, on the concealed information carrying surface, or in a line The pressure-sensitive adhesive composition according to claim 1 is applied by, for example, a gravure coater, and an adhesive layer composed of a number of fine convex patterns that do not adhere in a normal state is formed by a drying process, and the overlapping surfaces are brought into contact with each other. Adhesion can be obtained by applying a strong pressure in the wet state to obtain a sufficient adhesive force, and can be easily peeled off when peeled as necessary.
Claims 2 The information-carrying sheet is excellent in oxidation resistance degradation performance, heat resistance performance, and UV resistance performance, and has a remarkable effect that the adhesive strength does not decrease even when heated or irradiated with ultraviolet rays (UV).
[Brief description of the drawings]
FIG. 1 is a surface development view of a tri-fold postcard of the present invention.
FIG. 2 is a rear development view of the postcard of FIG.
3 is a cross-sectional view taken along line XX in FIG.
FIG. 4 is a state explanatory diagram when folding the postcard of FIG. 1;
FIG. 5 is a surface development view of a half-folded postcard of the present invention.
6 is a rear development view of the postcard of FIG. 5;
FIG. 7 is an explanatory diagram of a state when the postcard of FIG. 5 is folded.
FIG. 8 is a surface development view of a partially folded postcard of the present invention.
FIG. 9 is a developed rear view of the postcard in FIG. 8;
FIG. 10 is a state explanatory diagram when folding the postcard of FIG. 8;
[Explanation of symbols]
2, 12, 22 Base sheet
3, 3a, 3b Fold line
5 Concealment information printing
6 Peelable adhesive layer

Claims (2)

It is applied to the overlapping surfaces of the sheets, and an adhesive layer that does not adhere in a normal state is formed by a drying process. The overlapping surfaces can be brought into contact with each other and given a predetermined pressure so that the overlapping surfaces can be separated. A pressure sensitive adhesive to be bonded,
30 fine particle fillers having an average particle size of 0.1 to 20 μm with respect to 100 parts by mass of an ethylene-vinyl acetate polymer adhesive base having a Tg of −25 to −45 ° C. and a solid content of the adhesive base 30 A pressure-sensitive adhesive composition excellent in deterioration resistance, characterized by being blended at a ratio of ˜100 parts by mass. An adhesive layer made of a multiplicity of fine convex pattern of overlapping the entire surface or in hiding information carrying surface or in a linear pressure sensitive adhesive composition having excellent resistance to deterioration of claim 1 Symbol placement of the base sheet An information carrying sheet.

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