JP3688027B2

JP3688027B2 - Pressure sensitive adhesive sheet

Info

Publication number: JP3688027B2
Application number: JP25822395A
Authority: JP
Inventors: 雄二清水
Original assignee: Dai Nippon Printing Co Ltd
Current assignee: Dai Nippon Printing Co Ltd
Priority date: 1995-09-12
Filing date: 1995-09-12
Publication date: 2005-08-24
Anticipated expiration: 2015-09-12
Also published as: JPH0976669A

Description

【０００１】
【発明の属する技術分野】
本発明は、親展葉書、通知書、クジ等に使用され、一時的に仮接着した接合面を剥離すると内部情報を視認でき、郵送時の仮接着の剥離を防止し且つ、剥離済みが容易に判る感圧接着シートに関する。
【０００２】
【従来の技術】
近年、剥がして開くと内部の隠蔽情報を視認できる親展葉書が、情報のセキュリティ性の点で普及している。
例えば、葉書の二倍大の葉書用紙を情報が記載済の面を内側にして二つ折りする際に、二枚の透明熱可塑性樹脂フィルムを剥離可能に接着し両面に感圧粘着層を施した再剥離性樹脂シートを挟み込んで、一枚の葉書のとするものがある。剥離時は前記樹脂フィルム同士の接合面で剥がれ、樹脂フィルムを透して内部の情報を視認できる。
【０００３】
また、情報記載前に、再剥離性の接着層を対面する仮接着予定面に予め形成しておき、該接着層の上に文字等をノンインパクトプリンタ（ＮＩＰ）等で印字後に折り込んで葉書とする再剥離型接着シートもある。このような接着シートに、基材に印字適性を持つ再剥離型粘着層を塗布形成した感圧接着シートがある。
【０００４】
【発明が解決しようとする課題】
ところで、上記の様な仮接着を利用した葉書は、その仮接着力が弱すぎると郵送時に仮接着部分が容易に剥がれいまい、また逆に仮接着力が強すぎると容易に剥がせず、場合によっては記載された情報も破壊されてしまう恐れもある。
また、親展葉書等ではセキュリティ性が問題であり、親展情報等を記載した葉書等で、仮に第３者が葉書を剥離して親展情報を見た後、再度仮接着させることができれば、宛先人本人に関知されずに、親展情報を盗み見ることが可能となってしまう。この為に、前記した樹脂シートによるものは、一度剥がすと再度仮接着できない様になっているが、高価であるという問題がある。一方、感圧接着タイプ等の安価な再剥離型接着シートでも、剥離後は再度仮接着できない様になっているが、強い圧力や熱等により、再度仮接着することも不可能ではないという問題がある。
ところで、親展情報等を記載した葉書等で、仮に第３者が葉書を剥離して親展情報を見た後、再度仮接着させることができれば、宛先人本人に関知されずに、親展情報を盗み見ることが可能となってしまう。この為に、前記した樹脂シートによるものは、一度剥がすと再度仮接着できない様になっているが、高価であるという問題がある。また、感圧接着タイプ等の安価な再剥離型接着シートでも、剥離後は再度仮接着できない様になっているが、強い圧力や熱等により、再度仮接着することも不可能ではないという問題がある。
そこで、本発明の課題は、安価な再剥離型粘着層タイプで、郵送等の取り扱いで仮接着が容易に剥がれることを防ぎ、また、仮接着後に一度剥離すると、剥離済みであることが容易に判る感圧接着シートを提供することである。
【０００５】
【課題を解決するための手段】
本発明の感圧接着シートは、基材の隠蔽情報が形成された仮接着予定面について、仮接着時に対面する一方の面には、接着前及び剥離後は通常の状態では接着せず、少なくとも圧力により接着する再剥離型粘着層が塗布形成され、他方の面には透明なオーバープリント層が形成され、剥離すると前記再剥離型粘着層とオーバープリント層間で剥離し、基材と再剥離型粘着層間、再剥離型粘着層上、及び基材とオーバープリント層間のうちのいずれか一箇所以上に形成された隠蔽情報が視認できる感圧接着シートであって、
オーバープリント層が形成された仮接着予定面には、該オーバープリント層が形成されておらず基材が露出し且つ再剥離型粘着層とオーバープリント層との接着力よりも強い接着力で基材と再剥離型粘着層とが接着する強接着部が、該仮接着予定面の周縁領域であって且つ該仮接着予定面の基材が対向接着する仮接着予定面の基材と直接に連接していない領域の少なくとも一部の周縁領域に形成され、仮接着時には該強接着部が封止部となり、更に仮接着後に剥離すると、仮接着前に露出していた強接着部の基材の少なくとも表層側が破壊して、対向接着していた再剥離型粘着層と共に再剥離型粘着層側に移行することで、発生した破壊面により剥離されたことが判る様にしたものである。
また、本発明の感圧接着シートは、上記感圧接着シートにおいて、オーバープリント層を紫外線硬化性樹脂から構成したものでもある。
また、本発明の感圧接着シートは、上記感圧接着シートにおいて、更に、仮接着予定面に強接着部が設けられた基材の該強接着部の内側に切り取り用ミシン目を設け、剥離のきっかけとしたものでもある。
【０００６】
【発明の実施の形態】
以下、図面を参照しながら、本発明の感圧接着シートについて詳述する。
先ず、図１は、本発明の感圧接着シートの一実施例として二つ折りの葉書用紙１０の仮接着予定面側を示す表面図であり、図２は図１の葉書用紙１０のＡ−Ａ線での断面図であり、図３は図１の葉書用紙１０の裏面図であり、図４は図１の葉書用紙１０を二つ折りにして一枚の葉書としたときの断面図である。
これら図面に示す葉書用紙１０は、中央の折込線５で区分された同一サイズの第１シート１１及び第２シート１２からなる。
第１シート１１及び第２シート１２は、全面が仮接着予定面となり、第１シート１１の基材１の表面全面に透明な再剥離型粘着層２が塗工形成され、第２シート１２の基材１の左辺縁部に強接着部６以外の全面には、透明な紫外線硬化性樹脂によるオーバープリント層４が印刷形成されている。
【０００７】
第２シート１２の仮接着予定面の左側の周縁部（すなわち長方形の該仮接着部の左側辺に沿っう部分）に設けられた強接着部６は、オーバープリント層が部分的に形成されていないために基材が露出した部分であり、再剥離型粘着層とオーバープリント層との接着力よりも強い接着力で露出した基材と再剥離型粘着層とが接着し、仮接着後に剥離すると、仮接着前に露出していた基材の少なくとも表層側が破壊して、対向接着していた再剥離型粘着層と共に再剥離型粘着層側に移行することで、第２シート１２の基材、或いは第１シート１１側の再剥離型粘着層の片方又は両方に発生した（強接着部の形状に見合う）破壊面により剥離されたことが判ることとなる。
強接着部６を設ける場所は、親展葉書等で郵送時に仮接着が容易に剥がれない様にするための封止部とするものでもあり、図１の様に第１シート１１及び第２シート１２が中央の折込線５で基材が直接に連接しており、折り込んで葉書とした状態でも連接しているものであれば、第２シートの仮接着予定面のうち該折込線の沿った部分には、設ける必要はなく、当該場所以外の仮接着予定面の周縁領域に設ける。図１では、左側辺に沿った領域のみであるが、上側辺及び下側辺に沿った周縁領域に設けてもよい。
【０００８】
第１シート１１及び第２シート１２の両仮接着予定面には、それぞれ隠蔽情報３ａ及び３ｂが形成されている。仮接着予定面における隠蔽情報３の（層構成中での）形成場所は、再剥離型粘着層とオーバープリント層間で剥離し、基材と再剥離型粘着層間、再剥離型粘着層上、及び基材とオーバープリント層間のうちのいずれか一箇所以上である。例えば、第１シート１１の隠蔽情報３ａは、再剥離型粘着層上に形成され、第２シート１２の隠蔽情報３ｂは、基材１上、即ち基材１とオーバープリント層４との間に形成する。なお、隠蔽情報は対面する仮接着予定面の片方のみでももちろん良い。
隠蔽情報の形成は、従来公知の電子写真印刷、インクジェット印刷等のプリンタ類による印刷手段、或いは基材上であれば、活版印刷、オフセット印刷、グラビア印刷等の一般印刷で従来公知の印刷手段で形成する。
なお、本発明でいう隠蔽情報とは、隠蔽を必要とする情報以外にも、隠蔽は必要ないが、仮接着することによって結果的に隠蔽される情報も含み、文字、記号、図形、絵柄、写真調画像等と任意である。また、プロセスカラーのオフセット印刷等で形成したカラー画像情報等でも良い。
【０００９】
また、図３に示す如く葉書用紙１０の裏面は、当実施例では第１シート１１側が宛先欄となる。そして、図４の如く、第１シート１１及び第２シート１２の仮接着予定面同士を接着すると、二つ折りされた一枚の葉書２０となり、該葉書２０を剥離するときは、再剥離型粘着層２とオーバープリント層４とが接する接合面Ｓから剥離して、内部の隠蔽情報３ａ及び３ｂが視認可能となると共に、強接着部６の部分において、基材の表面側が破壊して接着していた再剥離型粘着層側に移行して、表面が破壊された基材が露出することになる。また、第１シートの再剥離型粘着層の該当する部分では、第１シート側から移行してきた破壊された基材の表面側部分が該強接着部の形に付着する。
【００１０】
本発明の感圧接着シートでは、仮接着予定面を仮接着したときに強接着部が封止部となり不意に仮接着が剥離されるのを防げるが、もしも、剥離するときに強接着部が剥離のキッカケの邪魔になると感ずるのであれば、図５の如く強接着部の内側に切り取り用ミシン目７を設けることもできる。切り取り用ミシン目７の位置は、仮接着予定面の強接着部に沿った内側である。ミシン目は開封作業によって物理的に破壊されることで、強接着部による以外にさらに容易に意図的な剥離であることが判る。また簡単に剥離できるきっかけともなる。
【００１１】
また、本発明の感圧接着シートを例えば葉書用シートとして使用する場合は、上述の二つ折りタイプ以外に、Ｚ折りタイプ、三つ折りタイプ、四つ折りタイプ、或いは、折込線を介して葉書大のサイズの第１シートと該第１シートより小さい第２シートとからなり、折込線５折り込むと一枚の葉書となる半折りタイプ等の従来公知の各種形態を取り得る。また、折込線も葉書の縦方向に限らず横方向でも良い。また、一枚の用紙を折らずに、複数枚の用紙を積層するタイプでも良い。また、多数のマージナル孔が連設されたマージナル部を有し且つ一単位の用紙が複数連続した連続帳票でも良いし、カット紙プリンタ専用の枚葉のシートでも良い。
また、再剥離型粘着層及びオーバーコート層の形成面は、最低限、仮接着予定面であり、それは基材全面であっても基材の一部であってもよい。
また、従来公知の方法により、対面する片方のシートの角をカットする等して、剥がす時の剥離のきっかけを作っておいてもよい。例えば、ミシン目を設けた図５の感圧接着シートで、剥離時の角となる部分にきっかけ８を設けておく。
【００１２】
本発明の感圧接着シートの基材１としては、再剥離型粘着層と接着した所（強接着部）を剥離するときに、例えば、表面コート層等の少なくとも表面側が破壊して再剥離型粘着層側に移行し、内部の繊維質が露出する従来公知の、ＮＩＰ（ノンインパクトプリンタ）用紙等の紙類の他、予め形成してある表面層等の表面側部分が移行したことが目視判明できるのであれば、合成紙、ポリプロピレン樹脂、セルロース系樹脂、ポリエステル系樹脂、塩化ビニル系樹脂等の樹脂フィルム類、不織布類、及びこれらの複合体等でも使用できる。
【００１３】
再剥離型粘着層２としては、接着前及び剥離後は粘着性がなくて通常の状態では他のものと接着せず、圧力で、また必要に応じ熱を併用することでオーバーコート層及び基材と接着し、剥離時は再剥離型粘着層とオーバーコート層との界面（接合面）が剥離面Ｓとなり、且つ再剥離型粘着層と基材との接着では基材の少なくとも表面側が破壊して再剥離型粘着層側に移行するものであれば良い。
また、再剥離型粘着層２の上に隠蔽情報を印刷形成するならば、表面が印刷適正を有し、剥離時は表面に印刷された隠蔽情報は印刷形成された再剥離型粘着層側に残る様に剥離するものであれば良い。
、また、再剥離型粘着層２の下に隠蔽情報３があれば、下の隠蔽情報３を少なくとも視認できる程度に透明で、剥離時は再剥離型粘着層は塗工形成された基材側に残る様に剥離するものであれば良い。
【００１４】
本発明の感圧接着シートでは、再剥離型粘着層は、対面接着する仮接着予定面の片方のみである。そこで本発明の再剥離型粘着層としては、対面接着する仮接着予定面の両面に再剥離型粘着層を塗工形成する場合に従来公知のＮＲ（天然ゴム）系粘着剤を粘着主剤とシリカや澱粉等の充填剤とからなるものを、充填剤量を調整して、基材と接着力した後に剥離するときに基材が破壊される様に接着力を調整したものでもよい。
【００１５】
或いは、粘着主剤に、ソープフリー乳化重合で得た、スチレン−ブタジエンゴム（ＳＢＲ）やアクリロニトリル−ブタジエンゴム（ＮＢＲ）のゴムラテックス、或いはポリアクリル酸エステル等のアクリル系樹脂ラテックス等を用い、必要に応じて、更に通常の乳化重合によるラテックスとして、スチレン−ブタジエンゴム（ＳＢＲ）、カルボキシ変性ＳＢＲ（ＸＳＢＲ）、アクリロニトリル−ブタジエンゴム（ＮＢＲ）、或いは、アクリル変性天然ゴム（ＰＭＭＡ−ＮＲ）、ポリアクリル酸エステル等のアクリル樹脂系ラテックスの粘着剤等を併用し、これに充填剤として、ポリスチレン等からなる樹脂粒子等の充填剤、或いは従来公知の充填剤を混合したものを使用する。ポリスチレン等からなる樹脂粒子等の充填剤は、再剥離型粘着層を下の隠蔽情報を視認可能に透明にできる。
上記ＮＲ系以外の粘着主剤は、再剥離型粘着層の下に隠蔽情報を印刷形成する場合に、特にオフセット印刷インク等の印刷インクへの接着力が強く、剥離時に再剥離型粘着層が対面接着する仮接着面側に移行しない。
なお、従来公知のシリカ等の無機粒子や澱粉等の有機粒子の混合は、再剥離型粘着層表面の印刷適性を良好にする。
また、充填剤の配合量は、粘着主剤のドライタック及び目的とする物性により適宜調整するものである。
【００１６】
再剥離型粘着層は、粘着主剤に充填剤やその他の添加剤を適宜加えた塗液を、グラビアコート、エアナイフコート等の従来公知の塗工手段で、基材に塗工して形成する。
【００１７】
オーバーコート層４は、印刷又は塗工手段にて形成し、従来公知のメジウムインクやＯＰニス等とオフセット印刷用のオーバーコート用インク、グラビア塗工用の塗工液等を用いる。オーバーコート層は透明な樹脂層であり熱硬化性樹脂でも良いが、剥離力の制御が容易である点や感圧接着シート製造時の作業性等の点で、紫外線硬化性樹脂が良い。また、紫外線硬化性樹脂等からなるオーバーコート層には、ワックスやシリコーン等を含有させ、接着力を低下させて剥離力を調整しても良い。
【００１８】
【実施例】
二つ折り葉書用紙の基材として、ＮＩＰ用グロス系コート紙（日本製紙（株）製、ＭＣ−Ｇ＜１１０＞）を用い、この用紙の仮接着予定面となる表面側の面の略全面に所望の隠蔽情報を紫外線硬化型インクのオフセット印刷で形成した。
次いで、上記仮接着予定面の半分側に、以下の組成の再剥離型粘着剤をグラビアコーターにより塗工し、乾燥塗布重量３ｇ／ｍ²の再剥離型粘着層を形成した。また、残りの半分側には、透明な紫外線硬化性樹脂からなるオーバープリント用のインクにより、片隅の強接着部となる部分を残してオーバープリント層をオフセット印刷で形成して、図１の様な本発明の感圧接着シートを得た。
【００１９】

【００２０】
次に、この感圧接着シートを、中央で折り込んで二つ折りにし、接着予定面同士を対向させ、メールシーラー（大日本印刷（株）製、ＭＳ−９０００）で仮接着した。
仮接着後、強接着部も無理に剥がして仮接着面を剥離すると、再剥離型粘着層とオーバーコート層との界面を剥離面として剥離したが、強接着部では、オーバコート層から露出していた基材が、その表面側で材料破壊して、剥離して離れた再剥離型粘着層側に接着したまま移行して、再剥離型粘着層の表面に材料破壊した基材の一部が移行して付着し、またオーバコート層側の強接着部も基材が材料破壊したために、表面がざらつき、一見して直ぐに一度仮接着したものであることが判明できた。
さらに、この剥離された葉書を、前記メールシーラーで同様の圧力を加えると、再度仮接着させて一枚の葉書とすることができた。しかし、既に強接着部は破壊され接着していないために、一見して既に剥離済みの葉書であることが判明できた。
【００２１】
【発明の効果】
本発明の感圧接着シートによれば、強接着部が封止部となり、不意に仮接着が剥離することがない。
また、一度仮接着して剥離したものは、封止部となる強接着部が接着せず機能しないので、容易に判る。しかも、該強接着部及び該強接着部に対面していた再剥離型粘着層部分に基材の破壊面が発生することからも容易に判明できる。このため、不正に第３者が隠蔽情報をみるべく、仮接着を剥離して再度仮接着できたとしても、既に剥離された内部を盗み見られたことが容易に判明できる。また、安価でもある。
また、切り取り用ミシン目により、強接着部による封止部があっても、剥がそうとするときは、容易に剥がすことが出来る。
【図面の簡単な説明】
【図１】本発明の感圧接着シートの一実施例として二つ折りの葉書用紙の表面図。
【図２】図１の葉書用紙のＡ−Ａ線での断面図。
【図３】図１の葉書用紙の裏面図。
【図４】図１の葉書用紙から得た二つ折り葉書の断面図。
【図５】図１の葉書用紙で更に切り取り用ミシン目を設けた、本発明の感圧接着シートの他の実施例を示す表面図。
【符号の説明】
１基材
２再剥離型粘着層
３ａ，３ｂ隠蔽情報
４オーバーコート層
５折込線
６強接着部，白抜き文字
７切り取り用ミシン目
１０葉書用紙（感圧接着シート）
１１第１シート
１２第２シート
２０葉書
Ｓ剥離面[0001]
BACKGROUND OF THE INVENTION
The present invention is used for confidential postcards, notices, lotteries, etc., and when the temporarily bonded surface is peeled off, the internal information can be visually recognized, preventing temporary peeling during mailing and being easily peeled off. It relates to a pressure-sensitive adhesive sheet.
[0002]
[Prior art]
In recent years, confidential postcards that can visually recognize the concealment information when peeled open are becoming popular in terms of information security.
For example, when folding a postcard paper that is twice the size of a postcard with the information-written side inside, the two transparent thermoplastic resin films are peelably bonded to each other and a pressure-sensitive adhesive layer is applied to both sides. Some postcards have a removable resin sheet sandwiched between them. At the time of peeling, it peels off at the joint surface between the resin films, and the internal information can be seen through the resin film.
[0003]
Before information is written, a re-peelable adhesive layer is preliminarily formed on the surface to be temporarily bonded, and a letter or the like is folded on the adhesive layer after printing with a non-impact printer (NIP) or the like. There is also a re-peelable adhesive sheet. As such an adhesive sheet, there is a pressure-sensitive adhesive sheet in which a re-peelable pressure-sensitive adhesive layer having printability is applied to a substrate.
[0004]
[Problems to be solved by the invention]
By the way, postcards using temporary adhesive as described above may not be easily peeled off when the temporary adhesive force is too weak, and if the temporary adhesive force is too strong, Depending on the situation, the written information may be destroyed.
In addition, security is a problem with confidential postcards, etc. If a third party can peel off the postcards and look at the confidential information with a postcard containing confidential information, etc. It becomes possible to steal confidential information without knowing the person. For this reason, the above-described resin sheet cannot be temporarily bonded again after being peeled off, but there is a problem that it is expensive. On the other hand, even with an inexpensive re-peelable adhesive sheet such as pressure-sensitive adhesive type, it cannot be temporarily bonded again after peeling, but it is not impossible to temporarily bond again due to strong pressure, heat, etc. There is.
By the way, with a postcard that contains confidential information, etc., if a third party can peel off the postcard and look at the confidential information and then temporarily attach it again, the confidential information will be stolen without being aware of the recipient. It becomes possible. For this reason, the above-described resin sheet cannot be temporarily bonded again after being peeled off, but there is a problem that it is expensive. In addition, even with an inexpensive re-peelable adhesive sheet such as a pressure-sensitive adhesive type, it cannot be re-bonded again after peeling, but it is not impossible to re-bond temporarily due to strong pressure or heat. There is.
Therefore, the object of the present invention is an inexpensive re-peelable pressure-sensitive adhesive layer type, which prevents the temporary adhesion from being easily peeled off by handling such as mailing. It is to provide an understandable pressure sensitive adhesive sheet.
[0005]
[Means for Solving the Problems]
The pressure-sensitive adhesive sheet of the present invention is not temporarily bonded to one surface facing at the time of temporary bonding with respect to the temporary bonding scheduled surface on which the concealment information of the substrate is formed, and is not bonded in a normal state before bonding and at least after peeling. A re-peelable pressure-sensitive adhesive layer that adheres by pressure is applied and formed, and a transparent overprint layer is formed on the other surface. A pressure-sensitive adhesive sheet in which concealment information formed on any one or more of the adhesive layer, the re-peelable adhesive layer, and the base material and the overprint layer can be visually recognized,
The surface to be temporarily bonded on which the overprint layer is formed is exposed to a base material with an adhesive force stronger than the adhesive force between the re-peelable pressure-sensitive adhesive layer and the overprint layer without the overprint layer being formed. The strong adhesion portion where the material and the releasable pressure-sensitive adhesive layer adhere is a peripheral region of the temporary adhesion planned surface and directly with the base material of the temporary adhesion planned surface to which the base material of the temporary adhesion planned surface is oppositely bonded The base material of the strong adhesion part that is formed in at least a part of the peripheral area of the non-joined area, becomes a sealing part at the time of temporary adhesion, and is exposed before temporary adhesion when peeled off after temporary adhesion. When at least the surface side of the film is broken and moved to the re-peelable pressure-sensitive adhesive layer side together with the re-peelable pressure-sensitive adhesive layer that has been oppositely bonded, it can be seen that the peeled surface has been peeled off.
Moreover, the pressure-sensitive adhesive sheet of the present invention is the above pressure-sensitive adhesive sheet, wherein the overprint layer is composed of an ultraviolet curable resin.
Further, the pressure-sensitive adhesive sheet of the present invention is the above-mentioned pressure-sensitive adhesive sheet, further provided with a perforation for cutting on the inner side of the strong adhesion portion of the base material provided with a strong adhesion portion on the temporary adhesion planned surface, and peeling It is also a trigger for.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the pressure-sensitive adhesive sheet of the present invention will be described in detail with reference to the drawings.
First, FIG. 1 is a front view showing a temporary adhesion scheduled surface side of a bi-folded postcard paper 10 as an embodiment of the pressure-sensitive adhesive sheet of the present invention, and FIG. 2 is an AA view of the postcard paper 10 of FIG. 3 is a cross-sectional view taken along a line, FIG. 3 is a back view of the postcard paper 10 of FIG. 1, and FIG. 4 is a cross-sectional view of the postcard paper 10 of FIG.
A postcard sheet 10 shown in these drawings is composed of a first sheet 11 and a second sheet 12 of the same size divided by a central folding line 5.
The entire surfaces of the first sheet 11 and the second sheet 12 are temporarily bonded, and the transparent releasable pressure-sensitive adhesive layer 2 is formed on the entire surface of the substrate 1 of the first sheet 11. An overprint layer 4 made of a transparent ultraviolet curable resin is printed on the entire surface other than the strong adhesion portion 6 on the left edge of the substrate 1.
[0007]
The strong adhesion part 6 provided in the peripheral part of the left side of the temporary attachment plan surface of the second sheet 12 (that is, the part along the left side of the rectangular provisional adhesion part) has an overprint layer partially formed. This is a part where the base material is exposed because it is not, and the base material exposed with an adhesive strength stronger than the adhesive strength between the re-peelable pressure-sensitive adhesive layer and the overprint layer adheres to the re-peelable pressure-sensitive adhesive layer and peels off after temporary bonding Then, at least the surface layer side of the base material exposed before temporary adhesion is destroyed, and the base material of the second sheet 12 is transferred to the re-peelable pressure-sensitive adhesive layer side together with the re-peelable pressure-sensitive adhesive layer that is oppositely bonded. Or it turns out that it peeled by the fracture | rupture surface (corresponding to the shape of a strong adhesion part) which generate | occur | produced in one or both of the re-peeling type adhesive layer by the side of the 1st sheet | seat 11.
The place where the strong adhesion portion 6 is provided is also a sealing portion for preventing temporary adhesion from being easily peeled off during mailing with a confidential postcard or the like, and the first sheet 11 and the second sheet 12 as shown in FIG. If the base material is directly connected at the center folding line 5 and is connected even when folded into a postcard, the portion along the folding line of the pre-bonded planned surface of the second sheet However, it is not necessary to provide it, and it is provided in the peripheral region of the temporary adhesion planned surface other than the place. In FIG. 1, only the region along the left side is shown, but it may be provided in the peripheral region along the upper side and the lower side.
[0008]
Concealment information 3a and 3b are respectively formed on both temporary adhesion planned surfaces of the first sheet 11 and the second sheet 12. The concealment information 3 formation location (in the layer structure) on the temporary adhesion planned surface is peeled off between the re-peelable pressure-sensitive adhesive layer and the overprint layer, and on the base material and the re-peelable pressure-sensitive adhesive layer, on the re-peelable pressure-sensitive adhesive layer, and One or more of the substrate and the overprint layer. For example, the concealment information 3 a of the first sheet 11 is formed on the re-peelable pressure-sensitive adhesive layer, and the concealment information 3 b of the second sheet 12 is formed on the base 1, that is, between the base 1 and the overprint layer 4. Form. Of course, the concealment information may be only one of the faces to be temporarily bonded to each other.
The concealment information can be formed by a conventionally known printing means such as printing means by printers such as conventionally known electrophotographic printing and ink jet printing, or general printing such as letterpress printing, offset printing and gravure printing if on a substrate. Form.
Note that the concealment information referred to in the present invention does not require concealment other than information that requires concealment, but also includes information that is concealed as a result of temporary bonding, including characters, symbols, figures, patterns, It is optional with a photographic image. Also, color image information formed by process color offset printing or the like may be used.
[0009]
Further, as shown in FIG. 3, the back side of the postcard paper 10 is the destination column on the first sheet 11 side in this embodiment. Then, as shown in FIG. 4, when the preliminarily bonded surfaces of the first sheet 11 and the second sheet 12 are bonded to each other, the postcard 20 is folded in half. Peeling from the joint surface S where the layer 2 and the overprint layer 4 are in contact, the internal concealment information 3a and 3b becomes visible, and the surface side of the base material breaks and adheres at the strongly bonded portion 6 portion. It will move to the re-peeling type adhesive layer side which had been, and the base material with which the surface was destroyed will be exposed. Moreover, in the applicable part of the re-peelable pressure-sensitive adhesive layer of the first sheet, the destroyed surface-side part of the base material that has been transferred from the first sheet side adheres to the shape of the strong adhesion part.
[0010]
In the pressure-sensitive adhesive sheet of the present invention, when the temporarily bonded surface is temporarily bonded, the strong bonding portion becomes a sealing portion and prevents the temporary bonding from being peeled off unexpectedly. If it is felt that it is an obstacle to peeling, a perforation 7 for cutting can be provided inside the strong adhesion portion as shown in FIG. The position of the cut perforation 7 is the inner side along the strong adhesion portion of the temporary adhesion planned surface. The perforation is physically broken by the opening operation, and it can be understood that the perforation is intentional peeling more easily than by the strong adhesion portion. It also provides an opportunity for easy peeling.
[0011]
In addition, when the pressure-sensitive adhesive sheet of the present invention is used as, for example, a postcard sheet, in addition to the above-described two-fold type, a Z-fold type, a three-fold type, a four-fold type, or It consists of a first sheet of a size and a second sheet smaller than the first sheet, and can take various conventionally known forms such as a half-fold type that forms a postcard when the folding line 5 is folded. Further, the folding line is not limited to the vertical direction of the postcard but may be the horizontal direction. Further, a type in which a plurality of sheets are stacked without folding one sheet may be used. Further, it may be a continuous form having a marginal portion in which a large number of marginal holes are continuously provided and one unit of a plurality of sheets is continuous, or a sheet for exclusive use with a cut sheet printer.
Moreover, the formation surface of the re-peelable pressure-sensitive adhesive layer and the overcoat layer is at least a temporary adhesion planned surface, which may be the entire surface of the base material or a part of the base material.
Moreover, you may make the trigger of peeling at the time of peeling by cutting the corner | angular of the sheet | seat of one side which faces by the conventionally well-known method. For example, in the pressure-sensitive adhesive sheet of FIG. 5 provided with perforations, a trigger 8 is provided in a corner portion at the time of peeling.
[0012]
As the base material 1 of the pressure-sensitive adhesive sheet of the present invention, when the portion (strongly bonded portion) bonded to the re-peelable pressure-sensitive adhesive layer is peeled, for example, at least the surface side of the surface coat layer or the like is destroyed and re-peelable In addition to the conventionally known papers such as NIP (Non-impact Printer) paper that moves to the adhesive layer side and exposes the internal fibers, it is visually observed that the surface side part such as the previously formed surface layer has been transferred. As long as it can be found, resin films such as synthetic paper, polypropylene resin, cellulose resin, polyester resin, and vinyl chloride resin, nonwoven fabrics, and composites thereof can also be used.
[0013]
The re-peelable pressure-sensitive adhesive layer 2 is non-sticky before and after bonding, and does not adhere to other materials in a normal state. At the time of peeling, the interface (bonding surface) between the re-peelable pressure-sensitive adhesive layer and the overcoat layer becomes the peeled surface S, and at least the surface side of the base material breaks down when the re-peelable pressure-sensitive adhesive layer and the base material are bonded. And what is necessary is just to transfer to the releasable adhesive layer side.
Further, if the concealment information is printed on the re-peelable pressure-sensitive adhesive layer 2, the surface has printing suitability, and the concealment information printed on the surface at the time of peeling is printed on the side of the re-peelable pressure-sensitive adhesive layer. Any material that can be peeled off as long as it remains is acceptable.
In addition, if there is concealment information 3 below the re-peelable adhesive layer 2, it is transparent so that at least the lower concealment information 3 can be visually recognized. Any material can be used as long as it can be peeled off.
[0014]
In the pressure-sensitive adhesive sheet of the present invention, the re-peelable pressure-sensitive adhesive layer is only one of the temporarily bonded surfaces to be bonded to each other. Therefore, as the re-peelable pressure-sensitive adhesive layer of the present invention, when a re-peelable pressure-sensitive adhesive layer is applied and formed on both surfaces of the temporarily bonded surface to be face-to-face bonded, a conventionally known NR (natural rubber) pressure-sensitive adhesive is used as the main adhesive and silica. For example, the adhesive strength may be adjusted so that the base material is destroyed when it is peeled off after adjusting the amount of the filler and adhering to the base material.
[0015]
Alternatively, as the adhesive main agent, a styrene-butadiene rubber (SBR) or acrylonitrile-butadiene rubber (NBR) rubber latex obtained by soap-free emulsion polymerization, or an acrylic resin latex such as polyacrylic acid ester, or the like is necessary. According to the usual emulsion polymerization latex, styrene-butadiene rubber (SBR), carboxy-modified SBR (XSBR), acrylonitrile-butadiene rubber (NBR), acrylic modified natural rubber (PMMA-NR), polyacrylic acid An acrylic resin-based latex adhesive such as ester is used in combination, and a filler such as resin particles made of polystyrene or the like or a mixture of conventionally known fillers is used as the filler. The filler such as resin particles made of polystyrene or the like can make the re-peelable adhesive layer transparent so that the concealment information below can be seen.
Adhesive agents other than the above NR type have a strong adhesive force to printing ink such as offset printing ink when concealment information is printed under the re-peelable pressure-sensitive adhesive layer. It does not shift to the temporary bonding surface side to be bonded.
In addition, the mixing of conventionally known inorganic particles such as silica and organic particles such as starch improves the printability of the surface of the re-peelable pressure-sensitive adhesive layer.
Moreover, the compounding quantity of a filler is suitably adjusted with the dry tack of an adhesive main ingredient, and the target physical property.
[0016]
The re-peelable pressure-sensitive adhesive layer is formed by applying a coating liquid in which a filler and other additives are appropriately added to the pressure-sensitive adhesive main agent to a base material by a conventionally known coating means such as gravure coating or air knife coating.
[0017]
The overcoat layer 4 is formed by printing or coating means, and uses a conventionally known medium ink, OP varnish, etc., an overcoat ink for offset printing, a coating liquid for gravure coating, or the like. The overcoat layer may be a transparent resin layer and may be a thermosetting resin, but an ultraviolet curable resin is preferable in terms of easy control of the peeling force and workability when manufacturing a pressure-sensitive adhesive sheet. Further, the overcoat layer made of an ultraviolet curable resin or the like may contain wax, silicone, or the like, and may adjust the peeling force by reducing the adhesive force.
[0018]
【Example】
NIP gloss coated paper (manufactured by Nippon Paper Industries Co., Ltd., MC-G <110>) is used as the base material for the two-fold postcard paper. Desired concealment information was formed by offset printing of UV curable ink.
Next, a re-peelable pressure-sensitive adhesive having the following composition was applied to a half side of the surface to be temporarily bonded by a gravure coater to form a re-peelable pressure-sensitive adhesive layer having a dry coating weight of 3 g / m ² . In addition, an overprint layer is formed by offset printing on the other half side by using an overprinting ink made of a transparent ultraviolet curable resin, leaving a portion to be a strong adhesion portion at one corner, as shown in FIG. A pressure-sensitive adhesive sheet of the present invention was obtained.
[0019]

[0020]
Next, this pressure-sensitive adhesive sheet was folded at the center to be folded in half, the surfaces to be bonded were opposed to each other, and temporarily bonded with a mail sealer (manufactured by Dai Nippon Printing Co., Ltd., MS-9000).
After temporary bonding, if the strong adhesion part is forcibly removed and the temporary adhesion surface is peeled off, the interface between the re-peelable pressure-sensitive adhesive layer and the overcoat layer peels off as the peeling surface, but the strong adhesion part is exposed from the overcoat layer. The part of the base material that had broken down on the surface side of the base material that had been damaged, transferred to the re-peelable pressure-sensitive adhesive layer side that had been peeled off, and was destroyed on the surface of the re-peelable pressure-sensitive adhesive layer It was found that the surface of the over-coating layer side of the strong adhesion portion was destroyed due to the material destruction, and the surface was rough, and at first glance it was temporarily temporarily adhered.
Furthermore, when the same pressure was applied to the peeled postcard with the mail sealer, it could be temporarily bonded again to form a single postcard. However, since the strongly bonded portion was already broken and not bonded, it was apparently a postcard that had already been peeled off.
[0021]
【The invention's effect】
According to the pressure-sensitive adhesive sheet of the present invention, the strong adhesion portion becomes a sealing portion, and the temporary adhesion is not unexpectedly peeled off.
Moreover, what was once temporarily bonded and peeled off can be easily understood because the strong bonding portion serving as the sealing portion does not adhere and does not function. Moreover, it can be easily determined from the fact that the fracture surface of the base material is generated in the strong adhesion portion and the re-peeling type adhesive layer portion facing the strong adhesion portion. For this reason, even if the third party can illegally see the concealment information, even if the temporary adhesion is peeled off and temporary bonding can be performed again, it can be easily found that the already peeled inside has been stolen. It is also inexpensive.
Moreover, even if there is a sealing part by a strong adhesion part due to the cut perforation, it can be easily peeled off when trying to peel off.
[Brief description of the drawings]
FIG. 1 is a surface view of a folded postcard paper as an embodiment of the pressure-sensitive adhesive sheet of the present invention.
2 is a cross-sectional view taken along the line AA of the postcard paper of FIG. 1. FIG.
3 is a back view of the postcard paper in FIG. 1. FIG.
4 is a cross-sectional view of a folded postcard obtained from the postcard paper of FIG. 1. FIG.
FIG. 5 is a surface view showing another embodiment of the pressure-sensitive adhesive sheet of the present invention, in which the postcard paper of FIG. 1 is further provided with a perforation for cutting.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Base material 2 Removable adhesive layer 3a, 3b Concealment information 4 Overcoat layer 5 Folding line 6 Strong adhesion part, white character 7 Perforation 10 for cutting off Postcard paper (pressure-sensitive adhesive sheet)
11 First sheet 12 Second sheet 20 Postcard S Release surface

Claims

A re-peelable pressure-sensitive adhesive layer that adheres at least by pressure, but does not adhere to the normal surface before and after bonding, on one surface facing the temporary bonding, where the concealment information of the base material is formed. Is applied and formed, and a transparent overprint layer is formed on the other surface, and when peeled, it is peeled off between the re-peelable adhesive layer and the overprint layer, and on the substrate and the re-peelable adhesive layer, on the re-peelable adhesive layer And a pressure-sensitive adhesive sheet in which the concealment information formed in any one or more of the substrate and the overprint layer can be visually recognized,
The surface to be temporarily bonded on which the overprint layer is formed is exposed to a base material with an adhesive force stronger than the adhesive force between the re-peelable pressure-sensitive adhesive layer and the overprint layer without the overprint layer being formed. The strong adhesion portion where the material and the releasable pressure-sensitive adhesive layer adhere is a peripheral region of the temporary adhesion planned surface and directly with the base material of the temporary adhesion planned surface to which the base material of the temporary adhesion planned surface is oppositely bonded The base material of the strong adhesion part that is formed in at least a part of the peripheral area of the non-joined area, becomes a sealing part at the time of temporary adhesion, and is exposed before temporary adhesion when peeled off after temporary adhesion. The pressure-sensitive adhesive is characterized in that at least the surface layer side of the material is broken and moved to the re-peelable adhesive layer side together with the re-peelable pressure-sensitive adhesive layer that has been adhered to the opposite side, so that the peeled surface is peeled off. Sheet.

The pressure-sensitive adhesive sheet according to claim 1, wherein the overprint layer is made of an ultraviolet curable resin.

The pressure-sensitive adhesive sheet according to claim 1 or 2, wherein a perforation for cutting is provided on the inner side of the strong adhesion portion of the base material provided with the strong adhesion portion on the temporary adhesion planned surface.