JPH0579272B2 - - Google Patents
Info
- Publication number
- JPH0579272B2 JPH0579272B2 JP9602587A JP9602587A JPH0579272B2 JP H0579272 B2 JPH0579272 B2 JP H0579272B2 JP 9602587 A JP9602587 A JP 9602587A JP 9602587 A JP9602587 A JP 9602587A JP H0579272 B2 JPH0579272 B2 JP H0579272B2
- Authority
- JP
- Japan
- Prior art keywords
- adhesive
- polyfunctional monomer
- acrylate
- meth
- microspherical
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 230000001070 adhesive effect Effects 0.000 claims description 47
- 239000000853 adhesive Substances 0.000 claims description 45
- 239000000178 monomer Substances 0.000 claims description 24
- 239000004820 Pressure-sensitive adhesive Substances 0.000 claims description 17
- NIXOWILDQLNWCW-UHFFFAOYSA-M Acrylate Chemical compound [O-]C(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-M 0.000 claims description 11
- 239000003999 initiator Substances 0.000 claims description 7
- 238000010557 suspension polymerization reaction Methods 0.000 claims description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 7
- 239000007900 aqueous suspension Substances 0.000 claims description 6
- 239000002245 particle Substances 0.000 claims description 6
- 239000004094 surface-active agent Substances 0.000 claims description 6
- 239000000203 mixture Substances 0.000 claims description 5
- 125000006353 oxyethylene group Chemical group 0.000 claims description 4
- 125000001183 hydrocarbyl group Chemical group 0.000 claims 1
- 229920000642 polymer Polymers 0.000 description 12
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 11
- 238000004132 cross linking Methods 0.000 description 11
- 239000010410 layer Substances 0.000 description 10
- 239000004005 microsphere Substances 0.000 description 10
- 238000006116 polymerization reaction Methods 0.000 description 10
- 239000000758 substrate Substances 0.000 description 8
- 238000006243 chemical reaction Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 4
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- 239000012790 adhesive layer Substances 0.000 description 3
- 239000011521 glass Substances 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 239000003960 organic solvent Substances 0.000 description 3
- -1 polyoxyethylene Polymers 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- OZAIFHULBGXAKX-UHFFFAOYSA-N 2-(2-cyanopropan-2-yldiazenyl)-2-methylpropanenitrile Chemical compound N#CC(C)(C)N=NC(C)(C)C#N OZAIFHULBGXAKX-UHFFFAOYSA-N 0.000 description 2
- GOXQRTZXKQZDDN-UHFFFAOYSA-N 2-Ethylhexyl acrylate Chemical compound CCCCC(CC)COC(=O)C=C GOXQRTZXKQZDDN-UHFFFAOYSA-N 0.000 description 2
- 239000004342 Benzoyl peroxide Substances 0.000 description 2
- OMPJBNCRMGITSC-UHFFFAOYSA-N Benzoylperoxide Chemical compound C=1C=CC=CC=1C(=O)OOC(=O)C1=CC=CC=C1 OMPJBNCRMGITSC-UHFFFAOYSA-N 0.000 description 2
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 2
- 239000002202 Polyethylene glycol Substances 0.000 description 2
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 2
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 2
- 235000019400 benzoyl peroxide Nutrition 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 239000003431 cross linking reagent Substances 0.000 description 2
- 125000004386 diacrylate group Chemical group 0.000 description 2
- GVGUFUZHNYFZLC-UHFFFAOYSA-N dodecyl benzenesulfonate;sodium Chemical compound [Na].CCCCCCCCCCCCOS(=O)(=O)C1=CC=CC=C1 GVGUFUZHNYFZLC-UHFFFAOYSA-N 0.000 description 2
- 150000002430 hydrocarbons Chemical group 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 229920000058 polyacrylate Polymers 0.000 description 2
- 229920001223 polyethylene glycol Polymers 0.000 description 2
- 229940080264 sodium dodecylbenzenesulfonate Drugs 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 239000000725 suspension Substances 0.000 description 2
- 238000006276 transfer reaction Methods 0.000 description 2
- 239000004908 Emulsion polymer Substances 0.000 description 1
- 239000004593 Epoxy Substances 0.000 description 1
- 229920000877 Melamine resin Polymers 0.000 description 1
- CERQOIWHTDAKMF-UHFFFAOYSA-M Methacrylate Chemical compound CC(=C)C([O-])=O CERQOIWHTDAKMF-UHFFFAOYSA-M 0.000 description 1
- 229920003171 Poly (ethylene oxide) Polymers 0.000 description 1
- 150000001252 acrylic acid derivatives Chemical class 0.000 description 1
- 125000005250 alkyl acrylate group Chemical group 0.000 description 1
- 238000004873 anchoring Methods 0.000 description 1
- 239000003125 aqueous solvent Substances 0.000 description 1
- CQEYYJKEWSMYFG-UHFFFAOYSA-N butyl acrylate Chemical compound CCCCOC(=O)C=C CQEYYJKEWSMYFG-UHFFFAOYSA-N 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 238000004587 chromatography analysis Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- KBLWLMPSVYBVDK-UHFFFAOYSA-N cyclohexyl prop-2-enoate Chemical compound C=CC(=O)OC1CCCCC1 KBLWLMPSVYBVDK-UHFFFAOYSA-N 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- LQZZUXJYWNFBMV-UHFFFAOYSA-N dodecan-1-ol Chemical compound CCCCCCCCCCCCO LQZZUXJYWNFBMV-UHFFFAOYSA-N 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 229940079593 drug Drugs 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- LNCPIMCVTKXXOY-UHFFFAOYSA-N hexyl 2-methylprop-2-enoate Chemical compound CCCCCCOC(=O)C(C)=C LNCPIMCVTKXXOY-UHFFFAOYSA-N 0.000 description 1
- 239000002563 ionic surfactant Substances 0.000 description 1
- 239000012948 isocyanate Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000693 micelle Substances 0.000 description 1
- 239000011859 microparticle Substances 0.000 description 1
- 239000002736 nonionic surfactant Substances 0.000 description 1
- NZIDBRBFGPQCRY-UHFFFAOYSA-N octyl 2-methylprop-2-enoate Chemical compound CCCCCCCCOC(=O)C(C)=C NZIDBRBFGPQCRY-UHFFFAOYSA-N 0.000 description 1
- 150000002978 peroxides Chemical class 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 239000002985 plastic film Substances 0.000 description 1
- 229920006255 plastic film Polymers 0.000 description 1
- 238000007348 radical reaction Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 229930195734 saturated hydrocarbon Natural products 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 150000003613 toluenes Chemical class 0.000 description 1
Description
（産業上の利用分野）
本発明は、初期接着性に優れ、かつ再剥離性の
良好な感圧性接着剤に関する。
（従来の技術）
上質紙などの基材の一部に感圧性粘着剤層が形
成された再剥離性メモ用紙パツドや開閉自在封筒
がオフイスなどで利用されている。例えば感圧性
接着剤層を有する上記メモ用紙は、再剥離性が良
好であり、接着対象物から剥離後再び他の接着対
象物に接着させることも可能である。このような
用途に使用される接着剤は、初期接着性に優れ、
かつ再剥離性の良好であることが必要である。つ
まり、基材に該接着剤の層が形成されたシートを
接着対象物に軽く押しつけて接着させたときの接
着力が比較的高く、かつ強く押しつけて接着させ
たときにも接着力がそれほど上昇しないため比較
的小さな力で剥離され得ることが望まれる。さら
い、いわゆる糊残りがなく、かつ再び他の接着対
象物に良好な接着性をもつて接着しうることが望
まれる。
このような再剥離・再接着性を有する接着剤
（以下再剥離性接着剤という）およびこの接着剤
の層が形成されたシートが、例えば米国特許第
3691140号、米国特許第3857731号、米国特許第
4166152号、特開昭50−2736号公報および特開昭
60−11569号に開示されている。ここに記載され
た接着剤は、いずれもアルキルアクリレートモノ
マーと極性モノマーと水性懸濁重合して得られる
微球状の接着剤である。接着剤の形状を微球状と
したため比較的良好に再剥離がなされる。しか
し、例えば特開昭50−2736号公報に記載のモノマ
ー組成物を水性懸濁重合させると、重合反応時の
温度、時間、攪拌状態により得られる微球状接着
剤の品質が一定しない。このような接着剤を用い
て、例えば粘着シートを調製すると、得られるシ
ートの接着力などにバラツキを生じ、一定した品
質のシートが得られない。上記懸濁重合時には、
生じたラジカルにより（メタ）アクリレートモノ
マーが重合し主鎖を形成すると同時に、生じた
（メタ）アクリレートポリマーとラジカルとの間
のラジカル連鎖移動反応により架橋反応が起こる
と考えられる。しかし、このラジカルの連鎖移動
反応は、不確定性要素が大きく、ラジカル反応の
結果常に一定の架橋状態を有する安定した品質の
ポリマーは得られない。その結果、上記のような
品質のバラツキがもたらされると考えられる。さ
らに、このような接着剤は、微球状であるため基
材に対する接着性の度合もまたそれ程高くないた
め、この微球状接着剤を基材に接着させる接着剤
層、つまり下塗り層が必要となる（米国特許第
3857731号および特開昭60−11569号公報）。
（発明が解決しようとする問題点）
本発明は上記従来の欠点を解決するものであり
その目的とするところは、初期接着性および再剥
離性に優れた感圧性接着剤を提供することにあ
る。本発明の他の目的は、アクリル系モノマーの
重合反応により得られる安定した品質の微球状再
剥離性接着剤を提供することにある。本発明のさ
らに他の目的は、上記優れた性質を有し、かつ下
塗り層を必要としない再剥離性接着剤を提供する
ことにある。
（問題点を解決するための手段および作用）
本発明の微球状感圧性接着剤は、（メタ）アク
リレート、および分子内に２個以上の重合性不飽
和基を有し水溶性の多官能性モノマーを含有する
組成物を、油溶性開始剤および界面活性剤の存在
下で水性懸濁重合して得られる平均粒径10〜
150μmの微球状であり、そのことにより上記目的
が達成される。
本発明の微球状感圧性接着剤に使用される（メ
タ）アクリレート（アクリレートおよび／または
メタクリレートという）は、
(Industrial Application Field) The present invention relates to a pressure-sensitive adhesive having excellent initial adhesion and good removability. (Prior Art) Removable memo pads and removable envelopes, which have a pressure-sensitive adhesive layer formed on a portion of a base material such as high-quality paper, are used in offices and the like. For example, the memo paper having a pressure-sensitive adhesive layer has good removability, and after being peeled off from an object to be bonded, it can be reattached to another object to be bonded. Adhesives used for such applications have excellent initial adhesion and
In addition, it is necessary to have good removability. In other words, the adhesive strength is relatively high when a sheet with a layer of the adhesive formed on the base material is lightly pressed against the object to be adhered, and the adhesive strength increases significantly even when it is strongly pressed and adhered. Therefore, it is desirable to be able to peel off with a relatively small force. It is desired that the material be free from wiping, so-called adhesive residue, and be able to be bonded again to other objects to be bonded with good adhesion. An adhesive having such removable and readhesive properties (hereinafter referred to as a removable adhesive) and a sheet on which a layer of this adhesive is formed are disclosed in, for example, US Patent No.
3691140, U.S. Patent No. 3857731, U.S. Patent No.
No. 4166152, JP-A-50-2736 and JP-A-Sho
No. 60-11569. All of the adhesives described herein are microspherical adhesives obtained by aqueous suspension polymerization of an alkyl acrylate monomer and a polar monomer. Since the adhesive has a microspherical shape, it can be re-peeled relatively well. However, when the monomer composition described in, for example, JP-A-50-2736 is subjected to aqueous suspension polymerization, the quality of the resulting microspherical adhesive varies depending on the temperature, time, and stirring conditions during the polymerization reaction. For example, when a pressure-sensitive adhesive sheet is prepared using such an adhesive, the adhesive strength of the resulting sheet varies, making it impossible to obtain a sheet of consistent quality. During the above suspension polymerization,
It is thought that the (meth)acrylate monomer is polymerized by the generated radical to form a main chain, and at the same time, a crosslinking reaction occurs due to a radical chain transfer reaction between the generated (meth)acrylate polymer and the radical. However, this radical chain transfer reaction has large uncertainties, and as a result of the radical reaction, a polymer of stable quality that always has a constant crosslinked state cannot be obtained. As a result, it is thought that the above-mentioned variations in quality are brought about. Furthermore, since such adhesives are microspherical, the degree of adhesion to the substrate is not very high, so an adhesive layer, that is, an undercoat layer, is required to adhere the microspherical adhesive to the substrate. (U.S. Patent No.
3857731 and Japanese Patent Application Laid-Open No. 11569/1983). (Problems to be Solved by the Invention) The present invention solves the above-mentioned conventional drawbacks, and its purpose is to provide a pressure-sensitive adhesive with excellent initial adhesion and removability. . Another object of the present invention is to provide a microspherical removable adhesive of stable quality obtained by a polymerization reaction of acrylic monomers. Still another object of the present invention is to provide a removable adhesive that has the above-mentioned excellent properties and does not require an undercoat layer. (Means and effects for solving the problems) The microspherical pressure-sensitive adhesive of the present invention contains (meth)acrylate and a water-soluble polyfunctional adhesive having two or more polymerizable unsaturated groups in the molecule. The average particle size obtained by aqueous suspension polymerization of a composition containing a monomer in the presence of an oil-soluble initiator and a surfactant.
It has a microspherical shape of 150 μm, thereby achieving the above purpose. The (meth)acrylate (referred to as acrylate and/or methacrylate) used in the microspherical pressure-sensitive adhesive of the present invention is
【式】で示
され、R3は炭素数４〜９の飽和炭化水素基、そ
してR4はＨまたはCH3を表す。このような（メ
タ）アクリレートとしては、ｎ−ブチルアクリレ
ート、ｎ−ヘキシルメタクリレート、ｎ−オクチ
ルメタクリレート、２−エチルヘキシルアクリレ
ート、シキロヘキシルアクリレートなどが挙げら
れる。
分子内に２個以上の重合性不飽和基を有する水
溶性の多官能性モノマーは、次式（）で示され
る：It is represented by the formula: R 3 represents a saturated hydrocarbon group having 4 to 9 carbon atoms, and R 4 represents H or CH 3 . Examples of such (meth)acrylates include n-butyl acrylate, n-hexyl methacrylate, n-octyl methacrylate, 2-ethylhexyl acrylate, and cyclohexyl acrylate. A water-soluble polyfunctional monomer having two or more polymerizable unsaturated groups in the molecule is represented by the following formula ():
【式】
ここでR1はＨまたはCH3；R2はこの多官能性
モノマー（）が任意の割合で水と相溶し得るよ
うな性質を与えるｎ価の炭化水素基、またはこの
多官能性モノマー（）が任意の割合で水と相溶
し得るような性質を与えるｎ価の基であつてオキ
シエチレン単位を有する基であり；そしてｎ≧２
である。
多官能性モノマーのうち特に好ましいのは、オ
キシエチレン単位（−０−CH2−CH2）を４単位
以上含むモノマーである。それには例えば、次式
（）で表される化合物がある：[Formula] Here, R 1 is H or CH 3 ; R 2 is an n-valent hydrocarbon group that imparts the property that this polyfunctional monomer () can be miscible with water in an arbitrary ratio, or this polyfunctional An n-valent group having an oxyethylene unit that gives the property that the monomer () can be miscible with water in any proportion; and n≧2
It is. Particularly preferred among the polyfunctional monomers are monomers containing 4 or more oxyethylene units (-0- CH2 - CH2 ). For example, there is a compound represented by the following formula ():
【化】
ここでR1はＨまたはCH3、そしてｎ≧４であ
る。
本発明の接着剤調製のための原料組成物は、上
記（メタ）アクリレートを95〜99.0モル％の割合
で、そして上記多官能性モノマーを0.1〜５モル
％、好ましくは0.3〜１モル％の割合で含有する。
上記以外の重合性モノマーが4.9モル％以下の割
合で含有されていてもよい。（メタ）アクリレー
トの含有量が過少であり多官能性モノマーが過剰
であると得られるポリマーの架橋度が高すぎるた
め接着性が低下する。逆に（メタ）アクリレート
が過剰であり多官能性が過少であると得られるポ
リマーの架橋度が一定せず、物性にバラツキを生
じる。
開始剤（重合反応開始剤）は熱などにより分解
してラジカルを発生する性質を有する。本発明で
は、この開始剤としては、実質的に水に不溶であ
り（油溶性であり）、アクリル系モノマーに可溶
なものが使用される。例えば、アゾビスイソブチ
ロニトリルなどのアゾ化合物、ベンゾイルパーオ
キシドなどの過酸化物が好適に利用される。油溶
性開始剤は全モノマー成分100重量部に対し、
0.05〜0.5重量部の割合で使用される。
界面活性剤としては、ドデシルベンゼンスルホ
ン酸ナトリウムなどのイオン性界面活性剤、ポリ
オキシエチレンラウリルアルコールエーテルなど
の非イオン性界面活性剤が利用され得る。界面活
性剤は臨界ミセル濃度以上で使用され、通常、水
100重量部あたり0.3〜1.0重量部の割合で使用さ
れる。
本発明の微球状感圧性接着剤を得るには、上記
（メタ）アクリレート、多官能性モノマー、界面
活性剤および油溶性開始剤を水もしくは水性溶媒
に加えて攪拌しながら重合反応を行う、重合条件
は通常の水性懸濁重合反応に準じる。例えば75℃
前後で約２時間攪拌を行う。このようにして、平
均粒径が10〜150μmの粒径の揃つた微球状ポリマ
ーが得られる。この微球状接着剤は架橋度にバラ
ツキが少なく品質の安定した接着性を有する。こ
の接着剤を用いて、例えば粘着シートを調製する
には、得られた微球状の接着剤をトルエンなどの
有機溶媒に分散させて紙、プラスチツクフイルム
などの基材表面に塗布・乾燥して粘着剤層を形成
させる。この微球状感圧性接着剤を基剤に接着さ
せるための接着層（下塗り層）を必要としない。
このようにして、高品質の再剥離性感圧性接着
剤が得られる。この接着剤を調製する上記水性懸
濁重合反応においては、多官能性モノマーは水溶
性であるため反応液に溶解する。重合反応が開始
し、（メタ）アクリレートの重合が起こると形成
される微球状の（メタ）アクリレート重合体の表
面に上記多官能性モノマーが吸着し、微球体の表
面付近で主として架橋反応が起こり、微球体の中
心部の架橋度は低いと考えられる。この微球体ポ
リマーを上記のように例えばトルエンなどの有機
溶媒に懸濁させて基材表面に塗布すると、架橋度
の高い微球表面は有機溶媒に溶解しないため粒球
の形状を保持する。他方、中心部のポリマーは架
橋度が低いためその一部が溶媒に溶解して微球体
表面に浸出する。基材表面塗布後、乾燥させると
微球表面に浸出したポリマーが固化し、微球体が
基材表面に強固に接着する。つまりアンカー（投
錨）効果が得られる。そのため、従来の微球体接
着剤を使用するときのような下塗り層を必要とし
ない。さらに微球の中心は架橋度が低く柔軟性を
有するため初期接着性に優れ、小さい力でも例え
ば上記粘着シートを接着させることができる。
架橋構造を有する接着剤としては、特開昭57−
111368号公報にエマルジヨン系ポリマー100重量
部に架橋剤が２重量部以下の割合で配合された接
着剤が開示されている。架橋剤としては、多官能
エポキシ化合物、メラミン化合物、イソシアネー
ト化合物などが用いられ、例えば、溶剤塗工など
で基材上に塗布後、加熱することにより架橋反応
が起こるという点で本発明の接着剤とは異なる。
さらに、この接着剤を基材上に塗布して架橋反応
を起こさせるべく加熱すると球状のポリマーの型
がくずれフイルム状となるため、本発明のような
再剥離性接着剤としては適当とはいえない。この
他、架橋構造を有する微球体のポリマーとして
は、スチレン系の微粒子がクロマトグラフイー用
に製造されているが、これはTgが高いため接着
性を有しておらず、さらにビニル系の架橋剤を使
用しないことから、本発明の接着剤とは全く異な
る。
（実施例）
以下に本発明を実施例について説明する。
実施例
２−エチルヘキシルアクリレート（2EHA；三
菱油化(株)製）297ｇおよびベンゾイルパーオキシ
ド0.9ｇを２のセパラブルフラスコに入れ、こ
れに純水1000ｇ、界面活性剤としてドデシルベン
ゼンスルホン酸ナトリウム6.66ｇおよび多官能性
ポリマーとして次式で示されるポリエチレングリ
コールジアクリレート（新中村化学(株)製）３ｇ
（0.36モル％）を加えた。embedded image Here, R 1 is H or CH 3 and n≧4. The raw material composition for preparing the adhesive of the present invention contains the above (meth)acrylate in a proportion of 95 to 99.0 mol%, and the above polyfunctional monomer in a proportion of 0.1 to 5 mol%, preferably 0.3 to 1 mol%. Contain in proportion.
Polymerizable monomers other than those mentioned above may be contained in a proportion of 4.9 mol% or less. If the content of (meth)acrylate is too low and the polyfunctional monomer is excessive, the degree of crosslinking of the resulting polymer will be too high, resulting in poor adhesiveness. On the other hand, if the amount of (meth)acrylate is too much and the polyfunctionality is too little, the degree of crosslinking of the obtained polymer will not be constant, resulting in variations in physical properties. The initiator (polymerization reaction initiator) has the property of generating radicals when decomposed by heat or the like. In the present invention, the initiator used is one that is substantially insoluble in water (oil-soluble) and soluble in the acrylic monomer. For example, azo compounds such as azobisisobutyronitrile and peroxides such as benzoyl peroxide are preferably used. The oil-soluble initiator should be added to 100 parts by weight of all monomer components.
It is used in a proportion of 0.05 to 0.5 parts by weight. As the surfactant, ionic surfactants such as sodium dodecylbenzenesulfonate and nonionic surfactants such as polyoxyethylene lauryl alcohol ether can be used. Surfactants are used above the critical micelle concentration and are usually
It is used in a proportion of 0.3 to 1.0 parts by weight per 100 parts by weight. In order to obtain the microspherical pressure-sensitive adhesive of the present invention, the above-mentioned (meth)acrylate, polyfunctional monomer, surfactant, and oil-soluble initiator are added to water or an aqueous solvent, and a polymerization reaction is carried out with stirring. The conditions are similar to ordinary aqueous suspension polymerization reactions. For example 75℃
Stir for about 2 hours before and after. In this way, a microspherical polymer having a uniform particle size with an average particle size of 10 to 150 μm is obtained. This microspherical adhesive has adhesive properties with stable quality and little variation in the degree of crosslinking. To prepare a pressure-sensitive adhesive sheet using this adhesive, for example, the obtained microspherical adhesive is dispersed in an organic solvent such as toluene, applied to the surface of a substrate such as paper or plastic film, and dried to become adhesive. to form a drug layer. No adhesive layer (undercoat layer) is required for adhering this fine spherical pressure-sensitive adhesive to a base. In this way, a high quality removable pressure sensitive adhesive is obtained. In the aqueous suspension polymerization reaction for preparing this adhesive, the polyfunctional monomer is water-soluble and therefore dissolves in the reaction solution. When the polymerization reaction starts and polymerization of (meth)acrylate occurs, the above polyfunctional monomer is adsorbed on the surface of the microsphere-shaped (meth)acrylate polymer that is formed, and a crosslinking reaction occurs mainly near the surface of the microsphere. , the degree of crosslinking in the center of the microspheres is considered to be low. When this microsphere polymer is suspended in an organic solvent such as toluene and applied to the surface of a substrate as described above, the microsphere surface, which has a high degree of crosslinking, does not dissolve in the organic solvent and therefore maintains the shape of the granules. On the other hand, since the polymer in the center has a low degree of crosslinking, a part of it dissolves in the solvent and oozes out onto the surface of the microspheres. After coating on the surface of the substrate and drying, the polymer leached onto the surface of the microspheres solidifies, and the microspheres firmly adhere to the surface of the substrate. In other words, an anchor effect can be obtained. Therefore, there is no need for an undercoat layer as is required when using conventional microsphere adhesives. Furthermore, since the center of the microsphere has a low degree of crosslinking and is flexible, it has excellent initial adhesion and can adhere, for example, the pressure-sensitive adhesive sheet described above, even with a small force. As an adhesive having a cross-linked structure, JP-A-57-
No. 111368 discloses an adhesive in which 100 parts by weight of an emulsion polymer and a crosslinking agent are blended in a ratio of 2 parts by weight or less. As the crosslinking agent, a polyfunctional epoxy compound, a melamine compound, an isocyanate compound, etc. are used. For example, the adhesive of the present invention is characterized in that a crosslinking reaction occurs when heated after being applied to a substrate by solvent coating. It is different from.
Furthermore, when this adhesive is applied onto a substrate and heated to cause a crosslinking reaction, the spherical polymer shape collapses and forms a film, so although it is not suitable as a removable adhesive as in the present invention. do not have. In addition, styrene-based microparticles are manufactured for chromatography as microspherical polymers with a crosslinked structure, but these do not have adhesive properties due to their high Tg. This adhesive is completely different from the adhesive of the present invention because no adhesive is used. (Example) The present invention will be described below with reference to Examples. Example 297 g of 2-ethylhexyl acrylate (2EHA; manufactured by Mitsubishi Yuka Co., Ltd.) and 0.9 g of benzoyl peroxide were placed in a separable flask (No. 2), followed by 1000 g of pure water and 6.66 g of sodium dodecylbenzenesulfonate as a surfactant. and 3 g of polyethylene glycol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) represented by the following formula as a polyfunctional polymer.
(0.36 mol%) was added.
【式】
この懸濁液を40℃にて１時間、回転速度
270rpmで攪拌した後、液温を75℃に上げて重合
反応を開始させた。75℃にて２時間反応させた
後、温度を下げて重合反応を終了させた。重合懸
濁液にメタノールを加え、生成物を取り出し、乾
燥させた後、トルエン中に分散させた。ポリマー
の平均粒子径は約50μmであつた。このトルエン
分散液を上質紙に固型分が10ｇ／m2となるように
バーコーターで塗布し、乾燥させて紙粘着シート
を得た。
この粘着シートの性能を次のようにして評価し
た。その結果を下表に示す。
(1) 初期粘着性
ASTMによるプローブタツクテストを行う。
(2) 粘着力
JIS Ｚ−0237に記載の方法によるSP粘着力で
評価する。
(3) アンカー（投錨）性
粘着シートを平滑なガラス板にJIS Ｚ−0237に
記載の方法に従つて貼りつける。このガラス板を
60℃にて100時間放置した後、該粘着シートを剥
離し、ガラス面上の微細球の付着状況を観察す
る。
比較例
2EHAの量を100ｇとし、ポリエチレングリコ
ールジアクリレートを使用しなかつたこと以外は
実施例と同様に反応を行つた。この重合反応によ
り平均粒子径約50μmのポリマーが得られた。実
施例１と同様に粘着シートを調製し、その評価を
行つた。その結果を下表に示す。[Formula] This suspension was heated at 40℃ for 1 hour, and the rotation speed was
After stirring at 270 rpm, the liquid temperature was raised to 75°C to start the polymerization reaction. After reacting at 75°C for 2 hours, the temperature was lowered to complete the polymerization reaction. Methanol was added to the polymerization suspension, and the product was taken out, dried, and then dispersed in toluene. The average particle size of the polymer was approximately 50 μm. This toluene dispersion was applied to high-quality paper using a bar coater so that the solid content was 10 g/m 2 and dried to obtain a paper adhesive sheet. The performance of this adhesive sheet was evaluated as follows. The results are shown in the table below. (1) Initial adhesion Perform a probe tack test using ASTM. (2) Adhesive strength Evaluated by SP adhesive strength according to the method described in JIS Z-0237. (3) Anchor property: Attach the adhesive sheet to a smooth glass plate according to the method described in JIS Z-0237. this glass plate
After being left at 60°C for 100 hours, the adhesive sheet was peeled off and the state of adhesion of the microspheres on the glass surface was observed. Comparative Example 2 The reaction was carried out in the same manner as in Example except that the amount of EHA was 100 g and polyethylene glycol diacrylate was not used. This polymerization reaction yielded a polymer with an average particle size of about 50 μm. A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 and evaluated. The results are shown in the table below.
【表】
（発明の効果）
本発明により、このように、初期接着性に優れ
再剥離性の良好な微球状感圧性接着剤が得られ
る。この接着剤を用いて粘着シートを調製すると
該接着剤がアンカー効果を有するため下塗り層を
必要としない。このような感圧性接着剤は、接着
層を有するメモ用紙パツドや開閉自在の封筒など
の用途に好適に利用され得る。[Table] (Effects of the Invention) According to the present invention, a microspherical pressure-sensitive adhesive having excellent initial adhesion and good removability can be obtained. When a pressure-sensitive adhesive sheet is prepared using this adhesive, an undercoat layer is not required because the adhesive has an anchoring effect. Such pressure-sensitive adhesives can be suitably used for memo paper pads having an adhesive layer, openable and closable envelopes, and the like.
Claims (1)
以上の重合性不飽和基を有し水溶性の多官能性モ
ノマーを含有する組成物を、油溶性開始剤および
界面活性剤の存在下で水性懸濁重合して得られる
平均粒径10〜150μmの微球状感圧性接着剤。 ２ 前記組成物が、（メタ）アクリレートを95〜
99.9モル％の割合で、そして前記多官能性モノマ
ーを0.1〜５モル％の割合で含有する特許請求の
範囲第１項に記載の接着剤。 ３ 前記多官能モノマーが次式（）で示される
特許請求の範囲第１項に記載の接着剤： 【式】 ここでR1はＨまたはCH3；R2はこの多官能性
モノマー（）が任意の割合で水と相溶し得るよ
うな性質を与えるｎ価の炭化水素基、またはこの
多官能性モノマー（）が任意の割合で水と相溶
し得るような性質を与えるｎ価の基であつてオキ
シエチレン単位を有する基であり；そしてｎ≧２
である。 ４ 前記R2がオキシエチレン単位を４単位以上
含有する特許請求の範囲第３項に記載の接着剤。[Claims] 1. A composition containing a (meth)acrylate and a water-soluble polyfunctional monomer having two or more polymerizable unsaturated groups in the molecule, an oil-soluble initiator and a surfactant. A microspherical pressure-sensitive adhesive with an average particle size of 10 to 150 μm obtained by aqueous suspension polymerization in the presence of. 2 The composition contains (meth)acrylate from 95 to
Adhesive according to claim 1, containing a proportion of 99.9 mol % and a proportion of the polyfunctional monomer of 0.1 to 5 mol %. 3. The adhesive according to claim 1, wherein the polyfunctional monomer is represented by the following formula (): [Formula] where R 1 is H or CH 3 ; R 2 is the polyfunctional monomer () An n-valent hydrocarbon group that gives the property of being compatible with water in any ratio, or an n-valent group that gives the property that this polyfunctional monomer () can be compatible with water in any ratio and is a group having an oxyethylene unit; and n≧2
It is. 4. The adhesive according to claim 3, wherein R 2 contains 4 or more oxyethylene units.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9602587A JPS63260972A (en) | 1987-04-17 | 1987-04-17 | Microspherical pressure sensitive adhesive |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9602587A JPS63260972A (en) | 1987-04-17 | 1987-04-17 | Microspherical pressure sensitive adhesive |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63260972A JPS63260972A (en) | 1988-10-27 |
| JPH0579272B2 true JPH0579272B2 (en) | 1993-11-01 |
Family
ID=14153797
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9602587A Granted JPS63260972A (en) | 1987-04-17 | 1987-04-17 | Microspherical pressure sensitive adhesive |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63260972A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0337201A (en) * | 1989-07-04 | 1991-02-18 | Sekisui Plastics Co Ltd | Production of elastic acrylic particle |
| US5410016A (en) * | 1990-10-15 | 1995-04-25 | Board Of Regents, The University Of Texas System | Photopolymerizable biodegradable hydrogels as tissue contacting materials and controlled-release carriers |
| US5817206A (en) * | 1996-02-07 | 1998-10-06 | Dtm Corporation | Selective laser sintering of polymer powder of controlled particle size distribution |
-
1987
- 1987-04-17 JP JP9602587A patent/JPS63260972A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63260972A (en) | 1988-10-27 |
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