JP2004105369A - Adhesive member for body warmer, and body warmer using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent steaming of skin, rash and rubor even when sticking a body warmer directly to the skin and to keep high adhering characteristic. <P>SOLUTION: An adhesive member for a body warmer has an adhesive agent layer on one face of a base material. The water vapor transmission rate of the adhesive agent layer(temperature of 40 °C, humidity of 30 %RH and the thickness of the adhesive agent layer of 100μm) is ≥800g/m<SP>2</SP>day. Otherwise, the adhesive agent layer is formed on a single surface of the base material, and consists of an adhesive agent based on a polyether-based polymer having at least one alkenyl group in the molecule. It is desirable that the base material consists of two or more layers and is a laminated base material having a nonwoven fabric base material on at least one surface and that the adhesive agent layer is formed on the nonwoven fabric base material on one surface of the laminated base material. Furthermore, it is desirable that the nonwoven fabric base material is formed of fiber substances mainly consisting of sodium polyacrylate. <P>COPYRIGHT: (C)2004,JPO

Description

（式（１）において、Ｒ^１はポリエーテル系重合体を示し、Ｒ^２は水素原子又はメチル基を示す。Ｒ^３は「−Ｏ−」、「−ＯＣ（＝Ｏ）−」、「−Ｃ（＝Ｏ）Ｏ−」、「−Ｒ^４Ｏ−」、「−Ｒ^４ＯＣ（＝Ｏ）−」、「−Ｒ^４ＯＣ（＝Ｏ）Ｏ−」（なお、これらのＲ^３の基は、左側が「ＣＨ_２＝Ｃ（Ｒ^２）−」と結合し、右側が「Ｒ^１」と結合する）であり、Ｒ^４は２価の有機基である。ｍは０又は１であり、ｎは正の整数である）
【００２７】
前記式（１）において、Ｒ^１のポリエーテル系重合体としては、分子内にエーテル結合を有する重合体であれば特に制限されないが、例えば、繰り返し単位としてオキシエチレン、オキシプロピレン、オキシイソプロピレン、オキシテトラメチレン等のオキシアルキレンを１種又は２種以上有するポリオキシアルキレン系重合体などが挙げられる。具体的には、Ｒ^１のポリエーテル系重合体としては、ポリオキシエチレン、ポリオキシプロピレン、ポリオキシテトラメチレン、オキシエチレン−オキシプロピレン共重合体（例えば、ポリオキシエチレン−ポリオキシプロピレンブロック共重合体や、オキシエチレン−オキシプロピレンランダム共重合体等）などが挙げられる。
【００２８】
Ｒ^３におけるＲ^４は２価の有機基であり、該２価の有機基としては、特に制限されず、例えば、１個以上のエーテル結合を有していてもよい２価の炭化水素基が好適である。このようなエーテル結合を有していてもよい２価の炭化水素基としては、炭素数１〜２０の２価の炭化水素基が好適である。具体的には、エーテル結合を有していてもよい２価の炭化水素基としては、アルキレン基（例えば、メチレン基、エチレン基、トリメチレン基、プロピレン基、テトラメチレン基、２−メチルトリメチレン基、ペンタメチレン基、ヘキサメチレン基など）、アルキレン−オキシ−アルキレン基（例えば、エチレン−オキシ−エチレン基、エチレン−オキシ−トリメチレン基など）が挙げられる。また、２価の炭化水素基としては、前記の他、オキシアルキレン基、オキシカルボニルアルキレン基、オキシカルボニルオキシアルキレン基（これらは、オキシ部位がアルケニル基と結合している）などを用いることも可能である。
【００２９】
Ｒ^３としては、「−Ｒ^４Ｏ−」が好ましく、特に「−ＣＨ_２Ｏ−」が好適である。
【００３０】
ｍは０又は１であり、ｍが０の場合、Ｒ^３が存在しておらず、「ＣＨ_２＝Ｃ（Ｒ^２）−」が直接「Ｒ^１」と結合している状態を示している。
【００３１】
ｎは正の整数であり、例えば、１〜１０（好ましくは１〜４、さらに好ましくは１又は２）の整数が挙げられる。
【００３２】
なお、前記式（１）において、「ＣＨ_２＝Ｃ（Ｒ^２）−（Ｒ^３）_ｍ−」は、Ｒ^１のポリエーテル系重合体のいずれかの部位（好ましくは、主鎖や側鎖の末端、特に主鎖の末端）にｎ個結合していればよく、従って、詳細には、「Ｒ^１はポリエーテル系重合体の主要部である」とも言える。また、複数の「ＣＨ_２＝Ｃ（Ｒ^２）−（Ｒ^３）_ｍ−」が、Ｒ^１のポリエーテル系重合体に結合している場合、全部又は一部の「ＣＨ_２＝Ｃ（Ｒ^２）−（Ｒ^３）_ｍ−」が、ポリエーテル系重合体の同一の部位に結合していてもよく、全部が異なる部位に結合していてもよい。
【００３３】
このようなアルケニル基含有ポリエーテル系重合体としては、例えば、特開平４−１４５１８８号公報、特開平５−２０９１６４号公報などに記載されている公知のアルケニル基含有ポリエーテル系重合体を用いることができる。
【００３４】
アルケニル基含有ポリエーテル系重合体としては、数平均分子量が５，０００以上５０，０００以下（５，０００〜５０，０００）、好ましくは１０，０００以上３０，０００以下（１０，０００〜３０，０００）、より好ましくは１５，０００以上２５，０００以下（１５，０００〜２５，０００）であるものを好適に用いることができる。アルケニル基含有ポリエーテル系重合体の数平均分子量が５，０００未満であると硬化物の粘着性が低下し、一方、５０，０００を超えると塗工性が低下する。
【００３５】
なお、アルケニル基含有ポリエーテル系重合体による粘着剤は、無溶剤タイプの粘着剤であっても、室温（例えば、２３℃）で塗工することが可能である。この点から、アルケニル基含有ポリエーテル系重合体は、カイロ用粘着部材の粘着剤層を構成する粘着剤の粘着成分（ポリマー成分またはベースポリマー）として優れていると言える。
【００３６】
このようなアルケニル基含有ポリエーテル系重合体の製造方法としては、特に制限されず、公知乃至慣用の方法を採用することができ、例えば、特開平４−１４５１８８号公報や特開平５−２０９１６４号公報等に記載されているように、ポリエーテル系重合体を調製後にアルケニル基を導入する方法、ポリエーテル系重合体を調製中にアルケニル基を導入する方法などを用いることができる。
【００３７】
アルケニル基含有ポリエーテル系重合体を主体とする粘着剤（「アルケニル基含有ポリエーテル系粘着剤」と称する場合がある）としては、アルケニル基含有ポリエーテル系重合体を主体としていれば、架橋剤、触媒（例えば、ヒドロシリル化触媒など）、貯蔵安定性改良剤などの他の成分が含有されていてもよい。架橋剤としては、アルケニル基含有ポリエーテル系重合体を架橋させることができるものであれば特に制限されないが、例えば、分子中に少なくとも２個のヒドロシリル基を有する化合物（「ヒドロシリル基複数含有化合物」と称する場合がある）を好適に用いることができる。該架橋剤としてのヒドロシリル基複数含有化合物としては、例えば、特開平４−１４５１８８号公報や特開平５−２０９１６４号公報等に記載されている「分子中に少なくとも２個のヒドロシリル基を有する化合物［（Ｂ）成分］」などが挙げられる。
【００３８】
また、触媒としては、架橋剤としてヒドロシリル基複数含有化合物が用いられている場合は、ヒドロシリル化触媒を好適に用いることができる。該ヒドロシリル化触媒としては、アルケニル基含有ポリエーテル系重合体とヒドロシリル基複数含有化合物との架橋反応を促進させることができる触媒であれば特に制限されないが、例えば、特開平４−１４５１８８号公報や特開平５−２０９１６４号公報等に記載されている「ヒドロシリル化触媒［（Ｃ）成分］」などが挙げられる。
【００３９】
さらにまた、貯蔵安定性改良剤としては、アルケニル基含有ポリエーテル系重合体を主体とする組成物の貯蔵安定性を高めることができるものであれば特に制限されないが、例えば、特開平４−１４５１８８号公報や特開平５−２０９１６４号公報等に記載されている「貯蔵安定性改良剤［特開平５−２０９１６４号公報では（Ｅ）成分］」などが挙げられる。
【００４０】
粘着剤（特に、アルケニル基含有ポリエーテル系粘着剤）としては、架橋後の粘着剤組成物のゲル分率が３０重量％以上８０重量％以下（３０〜８０重量％）となるように調整されたものが好ましい。また、架橋後の粘着剤組成物の貯蔵弾性率（Ｇ´）が室温で１×１０^５Ｐａ以下となるように調整されたものが好ましい。このような架橋後の粘着剤組成物のゲル分率や貯蔵弾性率（Ｇ´）は、粘着成分（特に、アルケニル基含有ポリエーテル系重合体）の種類やその含有割合、架橋剤や触媒の種類やその使用量を適宜調整することにより、コントロールすることができる。なお、粘着成分としてのアルケニル基含有ポリエーテル系重合体が５，０００〜５０，０００の数平均分子量を有している場合、架橋後の粘着剤組成物のゲル分率が３０重量％未満では架橋後もべたつきがあり、一方８０重量％を超えると粘着性が低下して、必要な粘着力が得られない場合がある。
【００４１】
なお、粘着剤には、粘着付与剤などの他の樹脂成分が含有されていてもよく、含有されていなくてもよい。粘着剤に粘着付与樹脂が配合されている場合は、粘着付与樹脂の配合量が多くなると透湿性が低下することから、皮膚に直接貼り付ける用途の粘着剤組成物としては、配合量ができるだけ少ないことが好ましい。具体的には、粘着付与樹脂の配合量は、例えば、アルケニル基含有ポリエーテル系重合体１００重量部に対して５０重量部以下（好ましくは３０重量部以下、さらに好ましくは２０重量部以下、特に１０重量部以下）の範囲から選択することが望ましい。
【００４２】
粘着剤には、その他、溶剤、充填剤、顔料、紫外線吸収剤、酸化防止剤、含窒素シラン化合物、シリコン化合物等の各種添加剤が配合されていてもよい。粘着剤としては、乾燥工程を経ても微量に残留する溶剤（有機溶剤）による皮膚刺激を防止するために、溶剤を含有していないことが好ましい。すなわち、粘着剤としては、無溶剤の粘着剤を用いることが好ましい。
【００４３】
粘着剤層の厚み（乾燥後の厚み）は、例えば、５０〜２００μｍ（好ましくは７０〜１２０μｍ）程度である。粘着剤層の厚みが薄いと、充分な粘着力を得ることが困難になり、一方、厚すぎると熱硬化時に充分な硬化を得ることが困難になり、しかも、コストへの影響も考慮が必要である。
【００４４】
［基材］
カイロ用粘着部材の基材としては、特に制限されない。また、基材の層構成は特に制限されず、単層であってもよく、積層体であってもよい。基材としては、例えば、フィルム層、ヒートシール層、繊維による基材層（例えば、不織布基材層など）を有していてもよい。なお、市販されている貼るタイプのカイロ（特に、貼るタイプの使い捨てカイロ）では、発熱体成分を封入する袋体としては、通常、ポリエチレン系多孔質フィルムにナイロン製不織布（ナイロン不織布）をラミネートしたもの（例えば、日東ライフテック社製の商品名「ブレスロン」など）に、カイロ用粘着部材の基材がヒートシールされて形成されたものが用いられている。このような袋体の形成に際しては、ポリエチレン系多孔質フィルム側の面と、カイロ用粘着部材の基材の粘着剤層形成面と反対側の面とが向かい合った状態で且つ袋体となるようにヒートシールされている。従って、カイロ用粘着部材の基材としては、カイロ用粘着部材の基材の粘着剤層形成面と反対側の面には、前記ポリエチレン系多孔質フィルム等とヒートシール可能な素材による層が形成されていることが望ましい。
【００４５】
一方、透湿性や皮膚表面の蒸れ防止性などの観点からは、粘着剤層は、高吸水性を有する基材（高吸水性基材）又は高吸湿性を有する基材（高吸湿性基材）上に形成されていることが望ましい。このような高吸水性基材又は高吸湿性基材としては、特に制限されないが、布又は編物製基材、織物製基材、不織布基材（不織布製基材）などの繊維による基材が挙げられ、特に不織布基材を好適に用いることができる。
【００４６】
従って、カイロ用粘着部材の基材としては、２層以上で構成され且つ少なくとも一方の表面に不織布基材を有する積層基材が好適である。なお、粘着剤層は、前記積層基材の片面の不織布基材上に形成することができる。この際、前記積層基材の他方の面（粘着剤層形成面と反対側の面）はヒートシール層となっていることが重要である。
【００４７】
具体的には、不織布基材における不織布としては、特に制限されず、例えば、ナイロン製不織布、レーヨン製不織布など公知乃至慣用の不織布（天然繊維による不織布、合成繊維による不織布など）を使用することができるが、特に、ポリアクリル酸のナトリウム塩を１成分又は主成分とする繊維（繊維物質）により形成された不織布（「ポリアクリル酸ナトリウム塩繊維系不織布」と称する場合がある）が好適である。ポリアクリル酸ナトリウム塩繊維系不織布は、高吸水性および高吸湿性を発揮できる。そのため、ポリアクリル酸ナトリウム塩繊維系不織布を用いると、発汗により発生した水分を粘着剤層が透湿し、この透湿された水分をポリアクリル酸ナトリウム塩繊維系不織布が吸収する効果が発揮される。従って、発汗による水分が粘着剤層を通してポリアクリル酸ナトリウム塩繊維系不織布に吸収されるので、皮膚表面の蒸れをより一層抑制又は防止し、肌のかぶれや発赤をより一層抑制又は防止する効果が奏される。なお、不織布基材は単層、複層のいずれの形態を有していてもよい。
【００４８】
このようなポリアクリル酸ナトリウム塩繊維系不織布としては、例えば、商品名「ベルオアシス」（カネボウ合繊社製、ポリアクリル酸ナトリウム塩系ポリマー）などが市販されている。
【００４９】
なお、不織布において、繊維径、繊維長、目付などは特に制限されない。不織布は、１種の繊維のみから構成されていてもよく、複数種の繊維が組み合わせられて構成されていてもよい。
【００５０】
一方、ヒートシール層は、ヒートシール性を有する樹脂（ヒートシール性樹脂）により形成することができる。このようなヒートシール性樹脂としては、特に制限されないが、例えば、オレフィン系樹脂を用いることができ、中でも、低密度ポリエチレン、エチレン−酢酸ビニル共重合体、エチレン−α−オレフィン共重合体（例えば、エチレン−プロピレン共重合体など）などのエチレン系樹脂が好適である。ヒートシール性樹脂は単独で又は２種以上組み合わせて使用することができる。なお、ヒートシール層は単層、複層のいずれの形態を有していてもよい。
【００５１】
ヒートシールをより低温で行って高速加工するためには、より低融点のヒートシール性樹脂を用いることが有効であり、そのためには、例えば、メタロセン系触媒を用いて調製された低密度ポリエチレンなどが最も有効である。
【００５２】
なお、基材がフィルム層を有している場合、該フィルム層は、従来使用されているフィルム層を利用することができる。なお、フィルムに隠蔽性を付与するために、フィラー（例えば、チタン白など）を添加してもよく、具体的には、例えば、多層フィルムの中間層にフィラー（例えば、チタン白など）を添加してもよい。
【００５３】
さらにまた、基材の粘着剤層側の面（粘着剤層形成面）には、粘着剤との投錨性を向上させるため、下塗り剤が塗布されていてもよい。
【００５４】
基材の厚みは、特に制限されず、例えば、１０〜５００μｍ（好ましくは１２〜２００μｍ、さらに好ましくは１５〜１００μｍ）程度である。なお、基材には、必要に応じて、背面処理、帯電防止処理などの各種処理が施されていてもよい。
【００５５】
［カイロ用粘着部材］
カイロ用粘着部材は、基材と、該基材の片面に設けられた粘着剤層とを有している。粘着剤層は、公知乃至慣用のコーティング方式を利用して基材上に形成することができる。具体的には、粘着剤のコーティング方式としては、ロールコーティング方法、ダイコーティング方法等の適宜の塗工方式を選定可能であるが、メルトブローやカーテンスプレー方式が好ましく、特にカーテンスプレー方式が最適である。
【００５６】
カーテンスプレー方式を利用すると、基材上に粘着剤を繊維状に塗布することができ、多孔性を有する粘着剤層（多孔性粘着剤層）を形成することができる。粘着剤層が多孔性粘着剤層であると、汗をより一層透湿することができ、肌のかぶれや発赤をより一層防止する効果をもたらせることが可能となる。特に、多孔性粘着剤層（カーテンスプレー方式により粘着剤を繊維状に塗布して形成された多孔性粘着剤層など）と、吸水性不織布又は吸湿性不織布（ポリアクリル酸ナトリウム塩繊維系不織布など）とを組み合わせると、より一層汗を吸収することができ、その結果、さらにより一層かぶれや発赤を防止することができるようになる。
【００５７】
粘着剤層は、基材の片面に、通常全面的に形成されているが、部分的に形成されていてもよく、例えば、ストライプ塗工を利用してストライプ状に、ドット塗工を利用してドット状に部分的に形成されていてもよい。
【００５８】
なお、粘着剤層の透湿度は、粘着剤層がどのような形態で形成されていても、前述のように、基材上の塗布領域全面（例えば、片面全面など）に均一又はほぼ均一の厚みで塗布した際の透湿度として測定される。従って、粘着剤層がストライプ状やドット状に形成されていても、粘着剤層の透湿度は、同一の粘着剤を用いて基材上の塗布領域全面に均一又はほぼ均一の厚みで塗布して形成された粘着剤層として測定することができる。
【００５９】
粘着剤層は、無溶剤の粘着剤（溶剤を含有していない粘着剤）を塗布して形成されていることが好ましい。すなわち、粘着剤層は、無溶剤生産工程（無溶剤塗工工程）で得ることができる。
【００６０】
なお、粘着剤層は、剥離フィルム（セパレータ）により保護されていてもよい。このようなセパレータとしては、公知乃至慣用のセパレータを用いることができる。
【００６１】
カイロ用粘着部材は、例えば、図２に示されるように、カイロにおける発熱体成分を封入する袋体を構成する部材（カイロ用粘着シート）として利用することができる。図２は、本発明のカイロ用粘着部材が使用されたカイロの一例を示す概略断面図である。図２において、１はカイロ、２はカイロ用粘着部材、２ａは粘着剤層、２ｂは基材、２ｃはセパレータ、３はカイロ用袋体形成部材、４は発熱体成分を示す。図２では、カイロ１は、基材２ｂの片面に粘着剤層２ａ、セパレータ２ｃがこの順で形成されたカイロ用粘着部材２が、カイロ用袋体形成部材３と袋体となるようにヒートシールされ、且つ該袋体の内部には発熱体成分４が封入されている構成を有している。前記カイロ用袋体形成部材３としては、ナイロン不織布がラミネートされたポリエチレン系多孔質フィルムを用いることができる。
【００６２】
なお、該カイロ１を作製する方法としては、特に制限されないが、例えば、カイロ用粘着部材２と、カイロ用袋体形成部材３とを、所定の面が対向する形態で重ねて合わせて、開口部を有するように周囲をヒートシールして開口部を有する袋体（例えば、３方をヒートシールした袋体など）を作製し、該開口部を有する袋体の内部に前記開口部から発熱体成分４を投入した後、前記開口部をヒートシールすることにより、袋体に発熱体成分を封入して、カイロを作製する方法などが挙げられる。このように、本発明のカイロ用粘着部材は、粘着剤層を有する状態でヒートシール加工を経ても、前記粘着剤層は優れた粘着特性を保持又は維持することが可能である。従って、本発明のカイロ用粘着部材を用いると、容易に、カイロ（貼るタイプのカイロ）を作製することができる。
【００６３】
なお、カイロ用粘着部材は、図３に示されるように、カイロにおける発熱体成分を封入する袋体に貼付して用いることも可能である。また、図３は、本発明のカイロ用粘着部材が使用されたカイロの他の例を示す概略断面図である。図３において、１ａはカイロ、５は袋体を示す。図３では、カイロ１ａは、発熱体成分４が封入された袋体５の表面に、公知乃至慣用の接着手段を利用して、カイロ用粘着部材２が貼付されている構成を有している。なお、カイロ用粘着部材２は、基材２ｂの片面に粘着剤層２ａ、セパレータ２ｃがこの順で形成された構成を有している。
【００６４】
［カイロ］
本発明のカイロ（貼るタイプのカイロ）は、前記カイロ用粘着部材が使用されていれば、その構成は特に制限されない。本発明のカイロとしては、前記図２で示されるように、カイロ用粘着部材が発熱体成分を封入する袋体を構成する部材（カイロ用粘着シート）として使用された構成を有するものを好適に用いることができる。
【００６５】
本発明のカイロは、カイロ用粘着部材が前記構成を有しているので、皮膚に直接貼付しても、発汗による水分を透湿させて、皮膚表面の蒸れを抑制又は防止し、肌のかぶれや発赤を抑制又は防止することができ、従って、直貼り用カイロ（特に、直貼り用使い捨てカイロ）として、非常に有用である。
【００６６】
【発明の効果】
本発明のカイロ用粘着部材を用いたカイロによれば、皮膚に直接貼付しても、発汗による水分を透湿させて、皮膚表面の蒸れを抑制又は防止し、肌のかぶれや発赤を抑制又は防止することができる。また、本発明のカイロ用粘着部材は、粘着付与樹脂が使用されていなくても、又はその使用量が低減されていても、優れた接着性能を発揮することができる。特に、発熱体成分を封入する袋体を形成する際のヒートシール加工を経ても、優れた粘着特性を保持している。
【００６７】
【実施例】
以下に、実施例に基づいて本発明をより詳細に説明するが、本発明はこれらの実施例により限定されるものではない。
【００６８】
（実施例１）
［基材］
カイロ用粘着シートの基材として、低密度ポリエチレンフィルム（厚み２０μｍ）に、ナイロン不織布（商品名「エルタス」旭化成社製；４０ｇ目付け）を積層した複合フィルム（「複合フィルムＡ」と称する場合がある）を用いた。
［粘着剤］
カイロ用粘着シートの粘着剤層を構成する粘着剤として、分子中に少なくとの１個のアルケニル基を有するポリエーテル系重合体を主体とする粘着剤（本粘着剤は、室温で無溶剤塗工可能である）である商品名「サイリル粘着剤」（鐘淵化学工業株式会社製；数平均分子量２００００）：１００重量部に、硬化剤（商品名「ＣＲ５００」鐘淵化学工業株式会社製）：１．３重量部を添加した粘着剤組成物（「粘着剤Ａ」と称する場合がある）を用いた。
［カイロ用粘着シート］
前記粘着剤Ａをセパレータ上にコンマーダイレクトコーティング方式により、乾燥後の厚さが１００μｍとなるように展開して粘着剤層を形成した後、該粘着剤層と前記複合フィルムＡの不織布面とを貼り合わせ、その後、約１３０℃で３分間熱硬化させて、カイロ用粘着シートを得た。
【００６９】
（実施例２）
ナイロン不織布に代えて、高吸水性不織布（商品名「ベルオアシス」カネボウ合繊社製；４０ｇ目付け）を用いたこと以外は、実施例１と同様にして、カイロ用粘着シートを得た。
【００７０】
（実施例３）
［基材］
カイロ用粘着シートの基材として、ポリエチレン／エチレン−酢酸ビニル共重合体の混合フィルム（厚み４０μｍ）に、高吸水性不織布（商品名「ベルオアシス」カネボウ合繊社製；４０ｇ目付け）を積層した複合フィルム（「複合フィルムＢ」と称する場合がある）を用いた。
［粘着剤］
カイロ用粘着シートの粘着剤層を構成する粘着剤として、実施例１と同様の粘着剤組成物である粘着剤Ａ［すなわち、分子中に少なくとの１個のアルケニル基を有するポリエーテル系重合体を主体とする粘着剤（本粘着剤は、室温で無溶剤塗工可能である）である商品名「サイリル粘着剤」（鐘淵化学工業株式会社製；数平均分子量２００００）：１００重量部に、硬化剤（商品名「ＣＲ５００」鐘淵化学工業株式会社製）：１．３重量部を添加した粘着剤組成物］を用いた。
［カイロ用粘着シート］
前記粘着剤Ａをセパレータ上にカーテンスプレー方式により約３０ｇ／ｍ^２塗布して、多孔性粘着剤層を形成した後、該多孔性粘着剤層と、前記複合フィルムＢの不織布面とを貼り合わせたこと以外は、実施例１と同様にして、カイロ用粘着シートを得た。
【００７１】
（実施例４）
カイロ用粘着シートの基材として、［エチレン−α−オレフィン共重合体と低密度ポリエチレンとの混合樹脂層（ヒートシール層）］／［ポリエチレンとポリプロピレンと酸化チタンとの混合樹脂組成物層（中間層）／［ポリプロピレン（粘着剤層形成面側の層）］の３層構造で且つ厚さ（総厚み）が８０μｍである複合フィルム（「複合フィルムＣ」と称する場合がある）を用いたこと以外は、実施例３と同様にして、カイロ用粘着シートを得た。
【００７２】
（比較例１）
粘着剤として、スチレン−イソプレン−スチレンブロックコポリマー（ＳＩＳ；スチレンコンテント約２０重量％）：１００重量部に、水添テルペン系樹脂（商品名「クリアロンＰ−１０５」ヤスハラケミカル社製；粘着付与樹脂）：１００重量部、パラフィンオイル（商品名「ＰＷ−９０」出光石油社製；軟化剤）：３０重量部、および顔料としてチタン白：２０重量部を添加し混合した粘着剤組成物（「粘着剤Ｂ」）を用いた。
前記粘着剤Ｂを、ホットメルト塗工により、前記複合フィルムＡの不織布面上に塗布して粘着剤層を形成して、粘着シートを得た。
【００７３】
（評価）
実施例１〜４、比較例１で得られた粘着シートを、それぞれ、１００×１３０（ｍｍ）に切断し、該粘着シートの粘着剤層形成面と反対側の面と、前記粘着シートと同サイズの通気性シート（商品名「ブレスロン　ＢＲＮ−１２６０」日東ライフテック社製）のポリエチレン多孔質面とが対向する状態で両者を重ね合わせ、ヒートシール加工により３方をヒートシールした後、開放口から内部に、市販の「直貼り用使い捨てカイロ」中の発熱体成分（発熱体組成物）を投入し、さらに、残る１方（開放口）をヒートシール加工によりヒートシールして、直貼り用使い捨てカイロを作製した。このカイロを用いて、下記のフィーリング試験を行い、装着時、発熱時および剥離時における感触を評価した。
【００７４】
（フィーリング試験）
無作為に選出した１０名の人に、実施例１〜４、比較例１で得られた粘着シートによるカイロを、腰又は腹に貼ってもらい、カイロを貼る際の装着時における感触、カイロを貼った後の発熱時における感触、カイロを剥がす際の剥離時における感触を、フィーリングで評価してもらい、下記の評価基準により、装着時、発熱時および剥離時における感触を評価した。評価結果は表１に示した。
評価基準
○：１０名中７名以上の人が好感触又は問題なしと評価した
△：１０名中４〜６名の人が好感触又は問題なしと評価した
×：１０名中３名以下の人が好感触又は問題なしと評価した
【００７５】
【表１】

【００７６】
（粘着剤層の透湿度の測定試験）
実施例１〜４で用いた粘着剤Ａによる粘着剤層と、比較例１で用いた粘着剤Ｂによる粘着剤層について、下記の粘着剤層の透湿度の測定方法により、透湿度を測定したところ、粘着剤Ａによる粘着剤層の透湿度は１３００ｇ／ｍ^２・ｄａｙであり、粘着剤Ｂによる粘着剤層の透湿度は７０ｇ／ｍ^２・ｄａｙであった。
（粘着剤層の透湿度の測定方法）
粘着剤をセパレータ上の塗布領域全面にアプリケーターを用いて塗布して、乾燥や架橋を行った後、１００μｍの厚さ（乾燥後の厚さ）を有する粘着剤層を形成した後、該粘着剤層をナイロン製不織布（商品名「エルタス」旭化成社製；坪量４０ｇ／ｍ^２）の片面に転写して、粘着シートを作製する。この粘着シートを、粘着剤層を下側にして、２０ｇの水が入っているガラスカップ（高さ４０ｍｍ且つ内径４０ｍｍφ）の上面に載せ、これらの周囲を、商品名「Ｎｏ．５１」（日東電工株式会社製）によるビニールテープを用いて貼付して、ガラスカップに固定する。その後、粘着シートにより覆われたガラスカップを、４０℃、３０％ＲＨの恒温恒湿度器内に２０分間入れ、取り出して重量を測定し、この重量を初期重量（Ｗ_Ｏ）とする。更にその後、再度、４０℃、３０％ＲＨの恒温恒湿度器内に入れ、４時間後に取り出した後、重量（Ｗ_Ｈ）を測定して、下記の式（ａ）に基づいて、透湿度（ｇ／ｍ^２・ｄａｙ）を算出する。
透湿度＝［（Ｗ_Ｏ−Ｗ_Ｈ）×２４］／［（０．０２）^２×π×４］　式（ａ）
［式（ａ）において、透湿度の単位はｇ／ｍ^２・ｄａｙである。なお、Ｗ_Ｏ：初期重量、Ｗ_Ｈ：４時間後の重量である。πは３．１４とする］
【００７７】
（ヒートシール加工後の粘着力の評価試験）
実施例１および比較例１で得られた粘着シートの各々について、以下の方法でヒートシール加工後の粘着力を評価した。
ヒートシール機（テスター産業社製：ＴＰ−７０１−Ｂ）を使用して、図５で示されるように、ヒートシールバー（熱プレス）の間に粘着シートサンプル（粘着剤層にはセパレータが付いている状態）をはさみ、下記のヒートシール条件でヒートシールを行い、さらにヒートシール後、粘着シート（幅２０ｍｍ）をステンレス板に貼付し、貼付してから３０分後、引張試験機を使用して、引張速度：３００ｍｍ／分、剥離角度：１８０°にて剥離し、その際の粘着力（Ｎ／２０ｍｍ）を測定した。なお、比較として、ヒートシールを行っていない粘着シート（ヒートシール前の粘着シート）の粘着力（Ｎ／２０ｍｍ）についても、それぞれ、同様の方法で測定した。測定結果は表２に示した。
ヒートシール条件
・エアー圧力：３．０ｋｇ／ｃｍ^２（２．９４×１０^５Ｐａ）
・時間：２秒
・温度：１５０℃
【００７８】
図５はヒートシール方法を示す概略図である。図５において、１０は粘着シート、１０ａは低密度ポリエチレンフィルム、１０ｂはナイロン不織布、１０ｃは粘着剤層、１０ｄはセパレータ、１１ａは上側のヒートシールバー、１１ｂは下側のヒートシールバー、１２はセパレータ（低密度ポリエチレンフィルムの保護層として使用）である。
【００７９】
【表２】

【００８０】
以上より、実施例に係る粘着シートを直貼りカイロ用の粘着シートとして用いると、直貼りカイロを皮膚に直接貼付しても、皮膚表面の蒸れが抑制又は防止され、肌のかぶれや発赤を効果的に抑制又は防止することができる。これは、実施例で用いられた粘着剤の透湿度が、８００ｇ／ｍ^２・ｄａｙ以上であるからであると思われる。
【００８１】
また、実施例では、分子中に少なくとの１個のアルケニル基を有するポリエーテル系重合体を主体とする粘着剤を用いているので、カイロを作製するさいのヒートシール加工を経ても、粘着力の低下が抑制又は防止されており、優れた粘着力を保持している。従って、実施例に係る粘着シートによる直貼りカイロは、優れた粘着性で、皮膚に直接貼付することができる。しかも、粘着付与樹脂や溶剤（特に有機溶剤）などが含まれていないので、皮膚への悪影響を最小限に抑えることができる。
【図面の簡単な説明】
【図１】粘着剤層の透湿度の測定方法を示す概略図である。
【図２】本発明のカイロ用粘着部材が使用されたカイロの一例を示す概略断面図である。
【図３】本発明のカイロ用粘着部材が使用されたカイロの他の例を示す概略断面図である。
【図４】従来の一般的な使い捨てカイロの構成の一例を示す概略断面図である。
【図５】ヒートシール方法を示す概略図である。
【符号の説明】
１　　　カイロ
１ａ　　カイロ
２　　　カイロ用粘着部材
２ａ　　粘着剤層
２ｂ　　基材
２ｃ　　セパレータ
３　　　カイロ用袋体形成部材
４　　　発熱体成分
５　　　袋体
６　　　粘着シート
６１　　多層プラスチックシート基材
６１ａ　ヒートシール層
６１ｂ　フィルム層
６２　　粘着剤層
６３　　セパレータ
７　　　オレフィン系多孔質フィルム
８　　　発熱体成分
１０　　粘着シート
１０ａ　低密度ポリエチレンフィルム
１０ｂ　ナイロン不織布
１０ｃ　粘着剤層
１０ｄ　セパレータ
１１ａ　上側のヒートシールバー
１１ｂ　下側のヒートシールバー
１２　　セパレータ（低密度ポリエチレンフィルムの保護層として使用）[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a pressure-sensitive adhesive member (such as a pressure-sensitive adhesive sheet) used for attaching a warmer (heating element) to an application site and a warmer (particularly a disposable warmer) using the same. It is preferably used for applications to be directly applied to the skin, and due to the moisture permeability of the pressure-sensitive adhesive composition, even if used for a long time, it can suppress or prevent skin irritation and redness. About the Cairo used.
[0002]
[Prior art]
Conventionally, acrylic pressure-sensitive adhesives and rubber-based pressure-sensitive adhesives have been widely used as pressure-sensitive adhesives used for direct contact with the skin, such as adhesive plasters. Acrylic pressure-sensitive adhesives have high viscosity when used alone and are difficult to apply to substrates, so they are generally coated in a solution using an organic solvent and then dried in a heating oven. A method to make it happen is used. However, in such a method, a trace amount of the organic solvent may remain even after the drying step, and the trace amount of the residual organic solvent may cause skin irritation.
[0003]
In addition, since the acrylic pressure-sensitive adhesive (or the pressure-sensitive adhesive layer made of the pressure-sensitive adhesive) has almost no moisture permeability, the skin-applied surface may become stuffy and cause rash. Further, it is necessary to recover the organic solvent in the manufacturing process, and there is a problem in terms of environment.
[0004]
At present, a disposable body warmer of a sticking type (sticking type heating element) has been widely used regardless of the season for the purpose of simple heating means in winter and prevention of coldness in a cooling environment in summer. Such a disposable body warmer is usually attached to clothing such as underwear or directly attached to the skin.
[0005]
As a configuration of a general disposable body warmer, for example, a configuration as shown in FIG. 4 is given. Specifically, the configuration of the disposable body warmer includes an olefin-based porous film such as polyethylene (often used as a laminated base material with a nonwoven fabric) 7 and a film layer 61b having a heat seal layer 61a on one surface. A pressure-sensitive adhesive sheet 6 having a pressure-sensitive adhesive layer 62 formed on the surface of the multilayer plastic sheet base material 61 composed of two layers on the film layer 61b side is formed into a bag using heat sealing means. A configuration in which a heating element component 8 whose main component is is contained. The pressure-sensitive adhesive layer 62 is usually protected by a separator 63 as shown in FIG.
[0006]
In such a conventional disposable body warmer, the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is provided by tackifying a rubber-based polymer mainly composed of a styrene-based block copolymer such as styrene-isoprene-styrene block polymer (SIS). Softeners such as resins and paraffin oils, and adhesives to which titanium white, aluminum silicate, or the like is added to impart hiding power are generally used. This pressure-sensitive adhesive is basically capable of hot-melt coating without using an organic solvent, but is hydrophobic, and is still insufficient in moisture permeability of the pressure-sensitive adhesive (or the pressure-sensitive adhesive layer). In this respect, it has the same problem as the acrylic pressure-sensitive adhesive. That is, since the pressure-sensitive adhesive is hydrophobic and does not have moisture permeability, when it is directly attached to the skin (for example, when it is used as a so-called "direct-adhesive body warmer"), it is being applied (applied and used). In some cases, the sweat that has been sweated collects on the surface of the pressure-sensitive adhesive, and the surface of the skin becomes stuffy, causing skin irritation, redness, or a decrease in adhesive strength.
[0007]
In addition, from the viewpoint of minimizing the effect of the additional component of the adhesive on the skin, the adhesive includes many additional components (compounding components) such as a tackifier resin and a softener other than the main polymer as the adhesive component. It is preferable that the main polymer serving as the adhesive component is constituted solely without a complicated composition.
[0008]
The pressure-sensitive adhesive sheet may be provided on one side of the multi-layer plastic sheet base so that the pressure-sensitive adhesive layer is also arranged on the heat seal portion when forming the bag body enclosing the heating element component. In many cases, with conventional adhesives, the adhesive strength of the adhesive layer near the heat-sealed portion may be reduced after the heat-sealing process when forming the bag.
[Patent Document 1]
JP-A-7-8517
[Patent Document 2]
JP-A-7-109443
[Patent Document 3]
JP 2000-1399990 A
[Patent Document 4]
JP 2001-260293 A
[0009]
[Problems to be solved by the invention]
Therefore, an object of the present invention is to provide a body warmer that can permeate moisture due to perspiration, suppress or prevent stuffiness on the skin surface, and suppress or prevent skin irritation and redness, even when directly attached to the skin. An object of the present invention is to provide an adhesive member for use and a warmer using the same.
Another object of the present invention is to provide a pressure-sensitive adhesive member for a warmer capable of exhibiting excellent adhesive performance even when the tackifier resin is not used or the amount of the resin is reduced, and a warmer using the same. Is to provide.
Still another object of the present invention is to provide an adhesive member for a warmer that retains excellent adhesive properties even after a heat sealing process when forming a bag body enclosing a heating element component, and a warmer using the same. Is to do.
[0010]
[Means for Solving the Problems]
The present inventors have conducted intensive studies to achieve the above object, and as a result of adopting a pressure-sensitive adhesive that constitutes the pressure-sensitive adhesive layer, a pressure-sensitive adhesive that has moisture permeability to the pressure-sensitive adhesive itself. It has been found that moisture due to perspiration during heating of the body warmer can be released through the layer to suppress or prevent stuffiness. Further, when the pressure-sensitive adhesive layer is composed of a pressure-sensitive adhesive mainly composed of a specific polymer, without using an additional component such as a tackifier resin or a softening agent other than the main polymer as a pressure-sensitive adhesive component, or It has been found that even when the amount of used is reduced, excellent adhesive performance can be exhibited. Further, when the pressure-sensitive adhesive layer is composed of a pressure-sensitive adhesive mainly composed of a specific polymer, it retains excellent pressure-sensitive adhesive properties even after heat sealing when forming a bag for enclosing a heating element component. I found that. The present invention has been completed based on these findings.
[0011]
That is, the present invention is a pressure-sensitive adhesive member for a warmer having a pressure-sensitive adhesive layer on one surface of a substrate, wherein the pressure-sensitive adhesive layer has a moisture permeability (temperature of 40 ° C., humidity of 30% RH, thickness of the pressure-sensitive adhesive layer of 100 μm), 800 g / m ² -To provide an adhesive member for a warmer characterized by being not less than day.
[0012]
Further, the present invention is a pressure-sensitive adhesive member for a warmer having a pressure-sensitive adhesive layer on one surface of a substrate, wherein the pressure-sensitive adhesive layer is mainly composed of a polyether-based polymer having at least one alkenyl group in a molecule. Provided is a pressure-sensitive adhesive member for a warmer, which is constituted by a pressure-sensitive adhesive. The number average molecular weight of the polyether polymer is preferably from 5,000 to 50,000.
[0013]
In the present invention, the substrate is a laminated substrate having two or more layers and having a nonwoven substrate on at least one surface, and an adhesive layer is formed on a nonwoven substrate on one surface of the laminated substrate. Is preferred. Such a nonwoven fabric substrate may be formed of a fibrous substance containing a sodium salt of polyacrylic acid as a main component.
[0014]
The pressure-sensitive adhesive layer is preferably a porous pressure-sensitive adhesive layer, and the porous pressure-sensitive adhesive layer can be formed by applying a pressure-sensitive adhesive in a fibrous form on a substrate. Furthermore, the pressure-sensitive adhesive layer may be formed by applying a solventless pressure-sensitive adhesive.
[0015]
Such a pressure-sensitive adhesive member for a warmer may be a pressure-sensitive adhesive sheet for a warmer as a member constituting a bag body for enclosing a heating element in the warmer.
[0016]
The present invention also includes a warmer wherein the adhesive member for the warmer is used.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
As the pressure-sensitive adhesive member for a warmer of the present invention, the pressure-sensitive adhesive layer provided on one side of the base material has a thickness of 800 g / m ² One of the features is that it has a moisture permeability (temperature (temperature of outside air) of 40 ° C., humidity (humidity of outside air) of 30% RH, thickness of the pressure-sensitive adhesive layer of 100 μm) of day or more. Thus, the moisture permeability of the pressure-sensitive adhesive layer (temperature 40 ° C., humidity 30% RH, pressure-sensitive adhesive layer thickness 100 μm) is 800 g / m 2. ² -If it is day or more, even if the pressure-sensitive adhesive member is directly adhered to the skin using the pressure-sensitive adhesive layer (even if directly adhered), the pressure-sensitive adhesive layer allows moisture caused by perspiration to permeate, and It can suppress or prevent stuffiness on the surface, and can effectively suppress or prevent rash and redness of the skin.
[0018]
The moisture permeability of the pressure-sensitive adhesive layer (temperature 40 ° C., humidity 30% RH, pressure-sensitive adhesive layer thickness 100 μm) is 1200 g / m 2. ² Day or more, preferably 2000 g / m ² -It is preferable that it is day or more. Although the upper limit of the moisture permeability is not particularly limited, for example, 4000 g / m ² -Day (temperature of 40 ° C., humidity of 30% RH, thickness of the pressure-sensitive adhesive layer of 100 μm) may be used. The moisture permeability of the pressure-sensitive adhesive layer (temperature 40 ° C., humidity 30% RH, pressure-sensitive adhesive layer thickness 100 μm) is 800 g / m 2. ² -If it is less than day, the problem that the skin or the skin is stuffy and the skin or the skin develops rash or redness is likely to occur.
[0019]
In the present invention, the moisture permeability of the pressure-sensitive adhesive layer (or pressure-sensitive adhesive) can be measured as follows.
(Method of measuring the moisture permeability of the adhesive layer)
(1) An adhesive is applied to the entire application area on the separator using an applicator, and dried and cross-linked as necessary to form an adhesive layer having a thickness of 100 µm (thickness after drying). .
(2) The pressure-sensitive adhesive layer formed on the separator is transferred to one surface of a nonwoven fabric made of nylon (nonwoven fabric made of polyamide) to prepare a pressure-sensitive adhesive sheet. The nylon nonwoven fabric has a basis weight of 40 g / m. ² Use those. Specifically, as the nylon nonwoven fabric, for example, "ELTAS" (trade name, manufactured by Asahi Kasei Corporation) or the like can be used.
(3) After pouring 20 g of water into a glass cup having a height of 40 mm and an inner diameter of 40 mmφ, as shown in FIG. 1, place the adhesive layer on the lower side and place the adhesive sheet so as to cover the opening of the glass cup. The adhesive sheet is fixed on the glass cup by placing the adhesive sheet on the upper surface of a glass cup and using a vinyl tape having a trade name of “No. 51” (manufactured by Nitto Denko Corporation).
(4) The glass cup covered with the pressure-sensitive adhesive sheet is placed in a constant temperature / humidity chamber at 40 ° C. and 30% RH for 20 minutes, taken out and weighed, and the weight is measured as the initial weight (W). _O ).
(5) Next, the sample was put again in a constant temperature / humidity chamber at 40 ° C. and 30% RH and taken out after 4 hours. _H ) Is measured, and based on the following equation (a), the moisture permeability (g / m ² Calculate day).
Moisture permeability = [(W _O -W _H ) × 24] / [(0.02) ² × π × 4] Equation (a)
[In the formula (a), the unit of moisture permeability is g / m ² -It is day. Note that W _O : Initial weight, W _H : Weight after 4 hours. π is the pi, which can be 3.14]
[0020]
FIG. 1 is a schematic view showing a method of measuring the moisture permeability of the pressure-sensitive adhesive layer. In FIG. 1, 91 is an adhesive sheet, 91a is an adhesive layer, 91b is a nonwoven fabric made of nylon, 92 is a glass cup (height 40 mm, inner diameter 40 mmφ), 92a is an opening (upper surface) of the glass cup 92, and 93 is water. is there.
[0021]
In the pressure-sensitive adhesive member for a warmer of the present invention, the pressure-sensitive adhesive layer provided on one surface of the base material mainly comprises a polyether-based polymer having at least one alkenyl group in a molecule (“alkenyl group-containing polyether”). One of the features is that the pressure-sensitive adhesive comprises a pressure-sensitive adhesive. As described above, when the pressure-sensitive adhesive mainly containing the alkenyl group-containing polyether polymer is used, even if the tackifier resin is not used, or even if the amount used is reduced, sufficient adhesive performance is obtained. Can be effectively demonstrated. In addition, the adhesive layer can maintain or maintain excellent adhesive properties even after heat sealing processing when forming a bag as a warmer, and exhibit excellent adhesive strength when attaching the warmer. can do.
[0022]
The pressure-sensitive adhesive member for a warmer of the present invention only needs to satisfy one of the above two characteristics, but preferably satisfies both of the two characteristics.
[0023]
[Adhesive layer]
As the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer of the pressure-sensitive adhesive member for a warmer, the moisture permeability (temperature of 40 ° C., humidity of 30% RH, thickness of the pressure-sensitive adhesive layer of 100 μm) when forming the pressure-sensitive adhesive layer is 800 g / m. ² -The composition and the like are not particularly limited as long as they are not less than day. Therefore, from this viewpoint, a known or commonly used adhesive (for example, an acrylic adhesive, a rubber adhesive, a silicone adhesive, a urethane adhesive, etc.) can be used. However, as described above, from the viewpoint of achieving both the moisture permeability and the adhesive property of the body warmer, as the pressure-sensitive adhesive, a polyether polymer having at least one alkenyl group in the molecule (alkenyl group-containing polyether polymer) is used. (Polymer) is preferred.
[0024]
In the alkenyl group-containing polyether polymer, the alkenyl group is preferably an alkenyl group having a double bond at a terminal (such as a vinyl group or a vinylalkyl group). Specifically, as the alkenyl group, a vinyl group; a 1-alkylvinyl group such as a 1-methylvinyl group (isopropenyl group), a 1-ethylvinyl group, a 1-propylvinyl group, or a 1-isopropylvinyl group is preferably used. A vinyl group and a 1-methylvinyl group are particularly preferable. The alkenyl groups may be used alone or in combination of two or more.
[0025]
The alkenyl group may be directly bonded to the polyether polymer, or may be bonded via another group (such as a divalent organic group). Examples of other groups via which the alkenyl group is bonded to the polyether polymer include “—O—”, “—OC (＝ O) —”, “—C (＝ O) O—”, and “ -R ^a O- "," -R ^a OC (= O)-"," -R ^a OC (= O) O- "," -R ^a O—C (＝ O) NH— ”,“ —R ^a C (= O) O- "(R ^a Is a divalent organic group), and groups in which the "-O-" site in these groups is "-S-" or "-NH-". In these exemplified groups, the left side is bonded to the alkenyl group, and the right side is bonded to the polyether polymer.
[0026]
Specifically, preferred alkenyl group-containing polyether polymers include alkenyl group-containing polyether polymers represented by the following formula (1).
Embedded image

(In the formula (1), R ¹ Represents a polyether-based polymer; ² Represents a hydrogen atom or a methyl group. R ³ Are "-O-", "-OC (= O)-", "-C (= O) O-", "-R ⁴ O- "," -R ⁴ OC (= O)-"," -R ⁴ OC (= O) O- "(note that these R ³ The left side is "CH ₂ = C (R ² )-”, And the right side is“ R ¹ ) And R ⁴ Is a divalent organic group. m is 0 or 1, and n is a positive integer)
[0027]
In the above formula (1), R ¹ The polyether polymer is not particularly limited as long as it is a polymer having an ether bond in the molecule. For example, oxyalkylene such as oxyethylene, oxypropylene, oxyisopropylene, and oxytetramethylene as a repeating unit is 1 And polyoxyalkylene polymers having two or more species. Specifically, R ¹ Examples of the polyether-based polymer include polyoxyethylene, polyoxypropylene, polyoxytetramethylene, oxyethylene-oxypropylene copolymers (for example, polyoxyethylene-polyoxypropylene block copolymers, oxyethylene-oxy Propylene random copolymer).
[0028]
R ³ R in ⁴ Is a divalent organic group, and the divalent organic group is not particularly limited. For example, a divalent hydrocarbon group which may have one or more ether bonds is preferable. As such a divalent hydrocarbon group which may have an ether bond, a divalent hydrocarbon group having 1 to 20 carbon atoms is preferable. Specifically, examples of the divalent hydrocarbon group which may have an ether bond include an alkylene group (for example, a methylene group, an ethylene group, a trimethylene group, a propylene group, a tetramethylene group, a 2-methyltrimethylene group) , A pentamethylene group, a hexamethylene group, etc.) and an alkylene-oxy-alkylene group (eg, an ethylene-oxy-ethylene group, an ethylene-oxy-trimethylene group, etc.). In addition, as the divalent hydrocarbon group, in addition to the above, an oxyalkylene group, an oxycarbonylalkylene group, an oxycarbonyloxyalkylene group (these have an oxy moiety bonded to an alkenyl group) and the like can also be used. It is.
[0029]
R ³ As "-R ⁴ O- "is preferable, and particularly" -CH ₂ O- "is preferred.
[0030]
m is 0 or 1, and when m is 0, R ³ Does not exist and "CH ₂ = C (R ² )-”Is directly converted to“ R ¹ "Is shown.
[0031]
n is a positive integer, for example, an integer of 1 to 10 (preferably 1 to 4, more preferably 1 or 2).
[0032]
In the above formula (1), “CH ₂ = C (R ² )-(R ³ ) _m -”Is R ¹ N may be bonded to any site (preferably the terminal of the main chain or the side chain, particularly the terminal of the main chain) of the polyether-based polymer of the formula (I). ¹ Is the main part of the polyether-based polymer. " In addition, a plurality of "CH ₂ = C (R ² )-(R ³ ) _m -”Is R ¹ When bonded to a polyether polymer of the formula (I), all or a part of "CH ₂ = C (R ² )-(R ³ ) _m "-" May be bonded to the same site of the polyether-based polymer, or all may be bonded to different sites.
[0033]
As such an alkenyl group-containing polyether polymer, for example, a known alkenyl group-containing polyether polymer described in JP-A-4-145188 and JP-A-5-209164 may be used. Can be.
[0034]
The alkenyl group-containing polyether polymer has a number average molecular weight of 5,000 to 50,000 (5,000 to 50,000), preferably 10,000 to 30,000 (10,000 to 30,000). 000), more preferably 15,000 or more and 25,000 or less (15,000 to 25,000). If the number average molecular weight of the alkenyl group-containing polyether polymer is less than 5,000, the adhesiveness of the cured product will decrease, while if it exceeds 50,000, the coatability will decrease.
[0035]
The pressure-sensitive adhesive made of the alkenyl group-containing polyether polymer can be applied at room temperature (for example, 23 ° C.) even if it is a solventless type pressure-sensitive adhesive. From this point, it can be said that the alkenyl group-containing polyether-based polymer is excellent as a pressure-sensitive adhesive component (polymer component or base polymer) of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer of the pressure-sensitive adhesive member for a warmer.
[0036]
The method for producing such an alkenyl group-containing polyether polymer is not particularly limited, and any known or commonly used method can be employed. For example, JP-A-4-145188 and JP-A-5-209164 can be used. As described in gazettes, a method of introducing an alkenyl group after preparing a polyether polymer, a method of introducing an alkenyl group during preparation of a polyether polymer, and the like can be used.
[0037]
As the pressure-sensitive adhesive mainly containing an alkenyl group-containing polyether polymer (sometimes referred to as an “alkenyl group-containing polyether pressure-sensitive adhesive”), a cross-linking agent is mainly used if the alkenyl group-containing polyether polymer is mainly used. And other components such as a catalyst (for example, a hydrosilylation catalyst) and a storage stability improver. The crosslinking agent is not particularly limited as long as it can crosslink the alkenyl group-containing polyether-based polymer. For example, a compound having at least two hydrosilyl groups in the molecule (“a compound containing a plurality of hydrosilyl groups”) ) May be suitably used. Examples of the compound containing a plurality of hydrosilyl groups as the cross-linking agent include compounds described in JP-A-4-145188 and JP-A-5-209164, such as "compounds having at least two hydrosilyl groups in a molecule [ (B) component] ".
[0038]
When a compound containing a plurality of hydrosilyl groups is used as a crosslinking agent, a hydrosilylation catalyst can be preferably used. The hydrosilylation catalyst is not particularly limited as long as it can promote a cross-linking reaction between the alkenyl group-containing polyether-based polymer and the compound having a plurality of hydrosilyl groups, and examples thereof include JP-A-4-145188 and "Hydrosilylation catalyst [component (C) component]" described in JP-A-5-209164 and the like.
[0039]
Further, the storage stability improver is not particularly limited as long as it can enhance the storage stability of a composition mainly composed of an alkenyl group-containing polyether polymer. For example, JP-A-4-145188. And "storage stability improver [component (E) in JP-A-5-209164]" described in JP-A-5-209164 and JP-A-5-209164.
[0040]
The pressure-sensitive adhesive (particularly, an alkenyl group-containing polyether-based pressure-sensitive adhesive) is adjusted so that the gel fraction of the pressure-sensitive adhesive composition after crosslinking is 30% by weight or more and 80% by weight or less (30 to 80% by weight). Are preferred. The storage modulus (G ′) of the pressure-sensitive adhesive composition after crosslinking is 1 × 10 5 at room temperature. ⁵ It is preferable that the pressure is adjusted to be Pa or less. The gel fraction and storage modulus (G ′) of the pressure-sensitive adhesive composition after such cross-linking are determined by the type of the pressure-sensitive adhesive component (particularly, alkenyl group-containing polyether-based polymer) and its content, and the cross-linking agent and catalyst. It can be controlled by appropriately adjusting the type and the amount used. In addition, when the alkenyl group-containing polyether polymer as an adhesive component has a number average molecular weight of 5,000 to 50,000, if the gel fraction of the adhesive composition after crosslinking is less than 30% by weight. There is stickiness even after cross-linking, while if it exceeds 80% by weight, the tackiness is reduced and the required tackiness may not be obtained.
[0041]
The pressure-sensitive adhesive may or may not include another resin component such as a tackifier. When the tackifier resin is compounded in the pressure-sensitive adhesive, since the moisture permeability decreases when the compounding amount of the tackifier resin increases, the pressure-sensitive adhesive composition for application directly to the skin has a compounding amount as small as possible. Is preferred. Specifically, the compounding amount of the tackifier resin is, for example, 50 parts by weight or less (preferably 30 parts by weight or less, more preferably 20 parts by weight or less, particularly 100 parts by weight based on 100 parts by weight of the alkenyl group-containing polyether polymer. (Less than 10 parts by weight).
[0042]
In addition, various additives such as a solvent, a filler, a pigment, an ultraviolet absorber, an antioxidant, a nitrogen-containing silane compound, and a silicon compound may be blended in the adhesive. The pressure-sensitive adhesive preferably contains no solvent in order to prevent skin irritation due to a solvent (organic solvent) remaining in a trace amount even after the drying step. That is, it is preferable to use a solventless adhesive as the adhesive.
[0043]
The thickness (thickness after drying) of the pressure-sensitive adhesive layer is, for example, about 50 to 200 μm (preferably 70 to 120 μm). If the thickness of the pressure-sensitive adhesive layer is thin, it is difficult to obtain sufficient adhesive strength. On the other hand, if it is too thick, it is difficult to obtain sufficient curing at the time of heat curing, and it is necessary to consider the effect on cost. It is.
[0044]
[Base material]
The base material of the pressure-sensitive adhesive member for a warmer is not particularly limited. The layer configuration of the substrate is not particularly limited, and may be a single layer or a laminate. The substrate may include, for example, a film layer, a heat seal layer, and a substrate layer made of fibers (for example, a nonwoven fabric substrate layer). In a commercially available stick-type warmer (particularly, a stick-type disposable warmer), a bag for enclosing the heating element is usually formed by laminating a nonwoven nylon fabric (nylon nonwoven fabric) on a polyethylene porous film. The thing (for example, Nitto Lifetech Co., Ltd. product name "Breslon" etc.) that the base material of the adhesive member for cairo is heat-sealed and used is used. In the formation of such a bag, the surface of the polyethylene-based porous film side and the surface on the side opposite to the surface on which the pressure-sensitive adhesive layer is formed of the base material of the pressure-sensitive adhesive member face the bag. Heat sealed. Therefore, as the base material of the pressure-sensitive adhesive member for a warmer, a layer formed of a material heat-sealable with the polyethylene-based porous film or the like is formed on the surface opposite to the surface on which the pressure-sensitive adhesive layer is formed on the substrate of the warmer-adhesive member. It is desirable to have been.
[0045]
On the other hand, from the viewpoints of moisture permeability and prevention of stuffiness on the skin surface, the pressure-sensitive adhesive layer is formed of a highly water-absorbing substrate (highly water-absorbing substrate) or a highly moisture-absorbing substrate (highly hygroscopic substrate). ) Is desirable. Such a highly water-absorbing substrate or a highly hygroscopic substrate is not particularly limited, but a substrate made of fibers such as a cloth or knitted substrate, a woven substrate, and a nonwoven substrate (nonwoven substrate) is used. In particular, a nonwoven fabric substrate can be suitably used.
[0046]
Therefore, as the substrate of the pressure-sensitive adhesive member for a warmer, a laminated substrate composed of two or more layers and having a nonwoven fabric substrate on at least one surface is suitable. The pressure-sensitive adhesive layer can be formed on a nonwoven fabric substrate on one side of the laminated substrate. At this time, it is important that the other surface (the surface opposite to the surface on which the pressure-sensitive adhesive layer is formed) of the laminated base material is a heat seal layer.
[0047]
Specifically, the nonwoven fabric in the nonwoven fabric substrate is not particularly limited. For example, a known or commonly used nonwoven fabric (a nonwoven fabric made of a natural fiber, a nonwoven fabric made of a synthetic fiber, or the like) such as a nylon nonwoven fabric or a rayon nonwoven fabric can be used. In particular, a nonwoven fabric formed of fibers (fibrous substances) containing a sodium salt of polyacrylic acid as one component or as a main component (which may be referred to as a “polyacrylic acid sodium salt fiber-based nonwoven fabric”) is particularly preferable. . The sodium polyacrylate fiber nonwoven fabric can exhibit high water absorption and high moisture absorption. Therefore, when the polyacrylate sodium salt fiber nonwoven fabric is used, an effect is exhibited in which the pressure-sensitive adhesive layer permeates moisture generated by perspiration and the permeated moisture is absorbed by the polyacrylate sodium salt fiber nonwoven fabric. You. Therefore, since the water due to perspiration is absorbed by the polyacrylic acid sodium salt fiber nonwoven fabric through the adhesive layer, the effect of further suppressing or preventing stuffiness on the skin surface and further suppressing or preventing skin irritation and redness. Is played. In addition, the nonwoven fabric base material may have any form of a single layer or a multiple layer.
[0048]
As such a polyacrylic acid sodium salt fiber nonwoven fabric, for example, "Beloasis" (trade name, manufactured by Kanebo Gosen Co., Ltd., polyacrylic acid sodium salt polymer) is commercially available.
[0049]
In the nonwoven fabric, the fiber diameter, fiber length, basis weight, and the like are not particularly limited. The nonwoven fabric may be composed of only one kind of fiber, or may be composed of a combination of plural kinds of fibers.
[0050]
On the other hand, the heat sealing layer can be formed of a resin having heat sealing properties (heat sealing resin). Such a heat-sealable resin is not particularly limited. For example, an olefin-based resin can be used, and among them, low-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-α-olefin copolymer (for example, , Ethylene-propylene copolymer). The heat sealing resin can be used alone or in combination of two or more. Note that the heat seal layer may have any form of a single layer or a multiple layer.
[0051]
In order to perform heat sealing at a lower temperature and perform high-speed processing, it is effective to use a heat sealing resin having a lower melting point, for example, such as a low density polyethylene prepared using a metallocene catalyst. Is the most effective.
[0052]
When the substrate has a film layer, a conventionally used film layer can be used as the film layer. Note that a filler (for example, titanium white or the like) may be added to impart concealing properties to the film. Specifically, for example, a filler (for example, titanium white or the like) is added to the intermediate layer of the multilayer film. May be.
[0053]
Furthermore, a primer may be applied to the surface of the base material on the side of the pressure-sensitive adhesive layer (surface on which the pressure-sensitive adhesive layer is formed) in order to improve the anchoring property with the pressure-sensitive adhesive.
[0054]
The thickness of the substrate is not particularly limited, and is, for example, about 10 to 500 μm (preferably 12 to 200 μm, more preferably 15 to 100 μm). The substrate may be subjected to various treatments such as a back surface treatment and an antistatic treatment as necessary.
[0055]
[Adhesive for Cairo]
The pressure-sensitive adhesive member for a warmer has a base material and a pressure-sensitive adhesive layer provided on one surface of the base material. The pressure-sensitive adhesive layer can be formed on a substrate using a known or commonly used coating method. Specifically, as an adhesive coating method, an appropriate coating method such as a roll coating method and a die coating method can be selected, but a melt blow or curtain spray method is preferable, and a curtain spray method is particularly optimum. .
[0056]
When the curtain spray method is used, the pressure-sensitive adhesive can be applied to the substrate in a fibrous form, and a porous pressure-sensitive adhesive layer (porous pressure-sensitive adhesive layer) can be formed. When the pressure-sensitive adhesive layer is a porous pressure-sensitive adhesive layer, sweat can be further permeable, and an effect of further preventing skin irritation and redness can be brought about. In particular, a porous pressure-sensitive adhesive layer (such as a porous pressure-sensitive adhesive layer formed by applying a pressure-sensitive adhesive in a fiber form by a curtain spray method) and a water-absorbing nonwoven fabric or a moisture-absorbing nonwoven fabric (such as a sodium polyacrylate fiber nonwoven fabric) ), Sweat can be further absorbed, and as a result, rash and redness can be further prevented.
[0057]
The pressure-sensitive adhesive layer is usually formed entirely on one surface of the base material, but may be formed partially, for example, in a stripe shape using stripe coating, using dot coating. May be partially formed in a dot shape.
[0058]
It should be noted that the moisture permeability of the pressure-sensitive adhesive layer is uniform or almost uniform over the entire application area on the substrate (for example, on one entire surface), as described above, regardless of the form of the pressure-sensitive adhesive layer. It is measured as the moisture permeability when applied in a thickness. Therefore, even if the pressure-sensitive adhesive layer is formed in a stripe shape or a dot shape, the moisture permeability of the pressure-sensitive adhesive layer is applied using the same pressure-sensitive adhesive to a uniform or almost uniform thickness over the entire application area on the substrate. It can be measured as a pressure-sensitive adhesive layer formed by the above method.
[0059]
The pressure-sensitive adhesive layer is preferably formed by applying a solventless pressure-sensitive adhesive (pressure-sensitive adhesive containing no solvent). That is, the pressure-sensitive adhesive layer can be obtained in a solventless production process (solventless coating process).
[0060]
The pressure-sensitive adhesive layer may be protected by a release film (separator). Known or commonly used separators can be used as such a separator.
[0061]
As shown in FIG. 2, for example, the pressure-sensitive adhesive member for a warmer can be used as a member (pressure-sensitive adhesive sheet for a warmer) constituting a bag body for enclosing a heating element in the warmer. FIG. 2 is a schematic cross-sectional view showing an example of a warmer in which the adhesive member for the warmer of the present invention is used. In FIG. 2, 1 is a warmer, 2 is an adhesive member for the warmer, 2a is an adhesive layer, 2b is a base material, 2c is a separator, 3 is a member for forming a warmer bag, and 4 is a heating element. In FIG. 2, the warmer 1 is heated such that the warmer adhesive member 2 in which the adhesive layer 2a and the separator 2c are formed in this order on one side of the base material 2b becomes a bag body with the warmer bag forming member 3. It has a configuration in which the heating element 4 is sealed and sealed inside the bag body. As the bag-forming member 3 for the body warmer, a polyethylene-based porous film on which a nylon nonwoven fabric is laminated can be used.
[0062]
The method for producing the warmer 1 is not particularly limited. For example, the adhesive member 2 for the warmer and the bag-forming member 3 for the warmer are overlapped with each other with a predetermined surface facing each other. A bag body having an opening (for example, a bag body heat-sealed on three sides) is prepared by heat-sealing the periphery so as to have a portion, and a heating element is inserted into the bag body having the opening from the opening. After the component 4 is charged, the opening is heat-sealed, thereby enclosing the heating element in a bag to produce a warmer. As described above, the pressure-sensitive adhesive member for a warmer of the present invention can retain or maintain excellent pressure-sensitive adhesive properties even if the pressure-sensitive adhesive layer is subjected to heat sealing in a state having the pressure-sensitive adhesive layer. Therefore, by using the pressure-sensitive adhesive member for a warmer of the present invention, a warmer (adherable warmer) can be easily manufactured.
[0063]
In addition, as shown in FIG. 3, the pressure-sensitive adhesive member for a warmer can be used by being attached to a bag for enclosing a heating element in the warmer. FIG. 3 is a schematic sectional view showing another example of a warmer in which the adhesive member for warmer of the present invention is used. In FIG. 3, 1a is a warmer and 5 is a bag. In FIG. 3, the warmer 1 a has a configuration in which the adhesive member 2 for the warmer is affixed to the surface of the bag body 5 in which the heating element component 4 is sealed by using a known or commonly used adhesive means. . Note that the pressure-sensitive adhesive member 2 has a configuration in which a pressure-sensitive adhesive layer 2a and a separator 2c are formed in this order on one surface of a base material 2b.
[0064]
[Cairo]
The configuration of the body warmer of the present invention (adhering type body warmer) is not particularly limited as long as the adhesive member for body warmer is used. As shown in FIG. 2, the warmer of the present invention preferably has a structure in which a warmer pressure-sensitive adhesive member is used as a member (a warmer pressure-sensitive adhesive sheet) constituting a bag for enclosing a heating element. Can be used.
[0065]
In the warmer of the present invention, since the adhesive member for the warmer has the above-described structure, even when directly attached to the skin, it allows moisture permeation due to perspiration to permeate and suppresses or prevents stuffiness on the surface of the skin. It can suppress or prevent redness, and is therefore very useful as a direct-attachable warmer (particularly, a direct-attachable disposable warmer).
[0066]
【The invention's effect】
According to the body warmer using the adhesive member for the body warmer of the present invention, even when directly adhered to the skin, by permeating moisture due to perspiration, suppressing or preventing stuffiness on the skin surface, suppressing rash and redness of the skin or Can be prevented. In addition, the pressure-sensitive adhesive member for a warmer of the present invention can exhibit excellent adhesive performance even if the tackifier resin is not used or the amount of the resin used is reduced. In particular, it retains excellent adhesive properties even after heat sealing when forming a bag enclosing the heating element component.
[0067]
【Example】
Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.
[0068]
(Example 1)
[Base material]
As a base material of the pressure-sensitive adhesive sheet for a warmer, a composite film in which a nylon nonwoven fabric (trade name: “ELTAS” manufactured by Asahi Kasei Corporation; 40 g basis weight) is laminated on a low-density polyethylene film (thickness: 20 μm) (sometimes referred to as “composite film A”). ) Was used.
[Adhesive]
As the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet for a warmer, a pressure-sensitive adhesive mainly composed of a polyether polymer having at least one alkenyl group in a molecule (this pressure-sensitive adhesive is applied at room temperature without solvent application) (Silyl adhesive) (manufacturable by Kaneka Chemical Co., Ltd .; number average molecular weight: 20,000): 100 parts by weight of a curing agent (trade name "CR500" manufactured by Kaneka Chemical Co., Ltd.) An adhesive composition (sometimes referred to as “adhesive A”) to which 1.3 parts by weight was added was used.
[Adhesive sheet for Cairo]
After forming the pressure-sensitive adhesive layer by spreading the pressure-sensitive adhesive A on a separator by a commercial direct coating method so that the thickness after drying becomes 100 μm, the pressure-sensitive adhesive layer and the nonwoven fabric surface of the composite film A are separated. Lamination was carried out, and thereafter, thermosetting was performed at about 130 ° C. for 3 minutes to obtain a pressure-sensitive adhesive sheet for a warmer.
[0069]
(Example 2)
A pressure-sensitive adhesive sheet for a warmer was obtained in the same manner as in Example 1, except that a highly water-absorbent nonwoven fabric (trade name "Bell Oasis" manufactured by Kanebo Gosen Co., Ltd .; 40 g basis weight) was used instead of the nylon nonwoven fabric.
[0070]
(Example 3)
[Base material]
As a base material of a pressure-sensitive adhesive sheet for a warmer, a composite in which a highly water-absorbing nonwoven fabric (trade name “Bell Oasis” manufactured by Kanebo Gosen Co .; 40 g weight) is laminated on a polyethylene / ethylene-vinyl acetate copolymer mixed film (40 μm thickness). A film (sometimes referred to as “composite film B”) was used.
[Adhesive]
As the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet for a warmer, pressure-sensitive adhesive A [ie, a polyether-based polymer having at least one alkenyl group in the molecule] which is the same pressure-sensitive adhesive composition as in Example 1 Product name "Silyl pressure sensitive adhesive" (manufactured by Kanegafuchi Chemical Industry Co., Ltd .; number average molecular weight: 20,000), which is a pressure sensitive adhesive mainly composed of coalesce (this pressure sensitive adhesive can be applied without solvent at room temperature): 100 parts by weight (A pressure-sensitive adhesive composition containing 1.3 parts by weight of a curing agent (trade name: "CR500" manufactured by Kaneka Chemical Co., Ltd.)) ".
[Adhesive sheet for Cairo]
About 30 g / m2 of the pressure-sensitive adhesive A was applied to the separator by curtain spraying. ² After applying to form a porous pressure-sensitive adhesive layer, the same procedure as in Example 1 was repeated except that the porous pressure-sensitive adhesive layer and the nonwoven fabric surface of the composite film B were bonded to each other. Got.
[0071]
(Example 4)
As a base material of the pressure-sensitive adhesive sheet for a warmer, [mixed resin layer of ethylene-α-olefin copolymer and low-density polyethylene (heat sealing layer)] / [mixed resin composition layer of polyethylene, polypropylene and titanium oxide (intermediate) A composite film (sometimes referred to as “composite film C”) having a three-layer structure of (layer) / [polypropylene (layer on the side where the pressure-sensitive adhesive layer is formed)] and having a thickness (total thickness) of 80 μm. Except for the above, an adhesive sheet for a warmer was obtained in the same manner as in Example 3.
[0072]
(Comparative Example 1)
As an adhesive, styrene-isoprene-styrene block copolymer (SIS; styrene content: about 20% by weight): 100 parts by weight, hydrogenated terpene resin (trade name "Clearon P-105" manufactured by Yashara Chemical Co .; tackifying resin): 100 parts by weight, 30 parts by weight of paraffin oil (trade name "PW-90" manufactured by Idemitsu Oil Co., Ltd .; softening agent), and 20 parts by weight of titanium white as a pigment were added and mixed, followed by mixing. ") Was used.
The pressure-sensitive adhesive B was applied on the nonwoven fabric surface of the composite film A by hot melt coating to form a pressure-sensitive adhesive layer, thereby obtaining a pressure-sensitive adhesive sheet.
[0073]
(Evaluation)
Each of the pressure-sensitive adhesive sheets obtained in Examples 1 to 4 and Comparative Example 1 was cut into 100 × 130 (mm), and the surface of the pressure-sensitive adhesive sheet opposite to the surface on which the pressure-sensitive adhesive layer was formed was the same as the pressure-sensitive adhesive sheet. The two sides are overlapped with the polyethylene porous surface of a breathable sheet of a size (trade name "Breslon BRN-1260" manufactured by Nitto Life Tech Co., Ltd.) facing each other, heat-sealed on three sides by heat sealing, and then opened. The heating element component (heating element composition) in the commercially available “disposable body warmer for direct application” is charged into the inside, and the other side (opening opening) is heat-sealed by heat sealing to directly apply. A disposable body warmer was made. Using this warmer, the following feeling test was performed, and the feeling at the time of mounting, heat generation and peeling was evaluated.
[0074]
(Feeling test)
Ten people randomly selected were asked to attach the cairo with the pressure-sensitive adhesive sheet obtained in Examples 1 to 4 and Comparative Example 1 to the waist or the belly. The feeling at the time of heat generation after application and the feeling at the time of peeling when removing the warmer were evaluated by feeling, and the feeling at the time of mounting, at the time of heat generation and at the time of peeling were evaluated according to the following evaluation criteria. The evaluation results are shown in Table 1.
Evaluation criteria
：: 7 or more people out of 10 evaluated it as good touch or no problem
Δ: 4 to 6 people out of 10 evaluated it as good touch or no problem
×: 3 or less people out of 10 evaluated that they had a good touch or no problem
[0075]
[Table 1]

[0076]
(Measurement test of moisture permeability of adhesive layer)
For the pressure-sensitive adhesive layer of the pressure-sensitive adhesive A used in Examples 1 to 4 and the pressure-sensitive adhesive layer of the pressure-sensitive adhesive B used in Comparative Example 1, the moisture permeability was measured by the following method for measuring the water vapor permeability of the pressure-sensitive adhesive layer. However, the moisture permeability of the pressure-sensitive adhesive layer by the pressure-sensitive adhesive A is 1300 g / m. ² -Day, and the moisture permeability of the pressure-sensitive adhesive layer by the pressure-sensitive adhesive B is 70 g / m ² -It was day.
(Method of measuring the moisture permeability of the adhesive layer)
The adhesive is applied to the entire application area on the separator using an applicator, dried and cross-linked, and then an adhesive layer having a thickness of 100 μm (dry thickness) is formed. The layer is made of nylon nonwoven fabric (trade name "ELTAS" manufactured by Asahi Kasei Corporation; basis weight 40 g / m) ² ) To form an adhesive sheet. This pressure-sensitive adhesive sheet is placed on the upper surface of a glass cup (40 mm in height and 40 mm in inner diameter) containing 20 g of water with the pressure-sensitive adhesive layer on the lower side, and the periphery thereof is trade name “No. 51” (Nitto). (Made by Denko Corporation) using vinyl tape and fixed to a glass cup. Thereafter, the glass cup covered with the adhesive sheet was placed in a constant temperature / humidity chamber at 40 ° C. and 30% RH for 20 minutes, taken out and weighed, and the weight was measured as the initial weight (W). _O ). After that, it was put again in a constant temperature / humidity chamber at 40 ° C. and 30% RH, taken out after 4 hours, and then weighed (W). _H ) Is measured, and based on the following equation (a), the moisture permeability (g / m ² Calculate day).
Moisture permeability = [(W _O -W _H ) × 24] / [(0.02) ² × π × 4] Equation (a)
[In the formula (a), the unit of moisture permeability is g / m ² -It is day. Note that W _O : Initial weight, W _H : Weight after 4 hours. π is 3.14]
[0077]
(Evaluation test of adhesive strength after heat sealing)
For each of the pressure-sensitive adhesive sheets obtained in Example 1 and Comparative Example 1, the pressure-sensitive adhesive strength after heat sealing was evaluated by the following method.
Using a heat sealing machine (manufactured by Tester Sangyo Co., Ltd .: TP-701-B), as shown in FIG. 5, an adhesive sheet sample (a separator is attached to the adhesive layer) between heat seal bars (hot press). ), And heat-sealed under the following heat-sealing conditions. After heat-sealing, a pressure-sensitive adhesive sheet (20 mm in width) was stuck on a stainless steel plate, and after 30 minutes from the stuck, a tensile tester was used. Then, peeling was performed at a tensile speed of 300 mm / min and a peeling angle of 180 °, and the adhesive force (N / 20 mm) at that time was measured. In addition, as a comparison, the adhesive force (N / 20 mm) of the pressure-sensitive adhesive sheet that was not heat-sealed (the pressure-sensitive adhesive sheet before heat-sealing) was also measured by the same method. The measurement results are shown in Table 2.
Heat sealing conditions
・ Air pressure: 3.0 kg / cm ² (2.94 × 10 ⁵ Pa)
・ Time: 2 seconds
・ Temperature: 150 ° C
[0078]
FIG. 5 is a schematic diagram showing the heat sealing method. In FIG. 5, 10 is an adhesive sheet, 10a is a low-density polyethylene film, 10b is a nylon nonwoven fabric, 10c is an adhesive layer, 10d is a separator, 11a is an upper heat seal bar, 11b is a lower heat seal bar, and 12 is It is a separator (used as a protective layer of a low density polyethylene film).
[0079]
[Table 2]

[0080]
As described above, when the pressure-sensitive adhesive sheet according to the example is used as a pressure-sensitive adhesive sheet for a directly-attached warmer, even when the directly-adhered warmer is directly adhered to the skin, the stuffiness of the skin surface is suppressed or prevented, and the effect of skin rash and redness is reduced. Can be suppressed or prevented. This is because the pressure-sensitive adhesive used in the examples has a moisture permeability of 800 g / m2. ² -It is considered that this is because it is not less than day.
[0081]
Further, in the embodiment, since an adhesive mainly comprising a polyether-based polymer having at least one alkenyl group in the molecule is used, even if the adhesive is subjected to a heat sealing process for producing a warmer, the adhesive is not affected. A decrease in force is suppressed or prevented, and excellent adhesive strength is maintained. Therefore, the direct-attached body warmer using the pressure-sensitive adhesive sheet according to the embodiment has excellent adhesiveness and can be directly adhered to the skin. Moreover, since it does not contain a tackifying resin or a solvent (particularly an organic solvent), it is possible to minimize adverse effects on the skin.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a method for measuring the moisture permeability of an adhesive layer.
FIG. 2 is a schematic sectional view showing an example of a warmer in which the adhesive member for the warmer of the present invention is used.
FIG. 3 is a schematic sectional view showing another example of a warmer in which the adhesive member for warmer of the present invention is used.
FIG. 4 is a schematic sectional view showing an example of the configuration of a conventional general disposable body warmer.
FIG. 5 is a schematic view showing a heat sealing method.
[Explanation of symbols]
1 Cairo
1a Cairo
2 Adhesive for Cairo
2a Adhesive layer
2b substrate
2c separator
3 Bag body forming member for Cairo
4 Heating element components
5 bags
6 Adhesive sheet
61 Multilayer plastic sheet substrate
61a Heat seal layer
61b film layer
62 adhesive layer
63 separator
7 Porous olefin film
8 Heating element components
10 Adhesive sheet
10a Low density polyethylene film
10b Nylon non-woven fabric
10c adhesive layer
10d separator
11a Upper heat seal bar
11b Lower heat seal bar
12 Separator (used as a protective layer for low density polyethylene film)

Claims (10)

A pressure-sensitive adhesive member for a warmer having a pressure-sensitive adhesive layer on one side of a substrate, wherein the pressure-sensitive adhesive layer has a moisture permeability (temperature of 40 ° C., humidity of 30% RH, thickness of the pressure-sensitive adhesive layer of 100 μm) of 800 g / m ² · day. An adhesive member for a warmer according to the above. What is claimed is: 1. A pressure-sensitive adhesive member for a warmer having a pressure-sensitive adhesive layer on one surface of a substrate, wherein the pressure-sensitive adhesive layer is constituted by a pressure-sensitive adhesive mainly composed of a polyether-based polymer having at least one alkenyl group in a molecule. An adhesive member for a warmer. The pressure-sensitive adhesive member according to claim 2, wherein the polyether polymer has a number average molecular weight of 5,000 to 50,000. The substrate is a laminated substrate having two or more layers and a nonwoven substrate on at least one surface, wherein the pressure-sensitive adhesive layer is formed on the nonwoven substrate on one side of the laminated substrate. 3. The pressure-sensitive adhesive member for a warmer according to any one of the above items 3. The pressure-sensitive adhesive member for a warmer according to claim 4, wherein the nonwoven fabric substrate is formed of a fiber material containing a sodium salt of polyacrylic acid as a main component. The pressure-sensitive adhesive member for a warmer according to any one of claims 1 to 5, wherein the pressure-sensitive adhesive layer is a porous pressure-sensitive adhesive layer. The pressure-sensitive adhesive member for a warmer according to claim 6, wherein the porous pressure-sensitive adhesive layer is formed by applying a pressure-sensitive adhesive in a fibrous form on a substrate. The pressure-sensitive adhesive member for a warmer according to any one of claims 1 to 7, wherein the pressure-sensitive adhesive layer is formed by applying a solventless pressure-sensitive adhesive. The pressure-sensitive adhesive sheet for a warmer according to any one of claims 1 to 8, which is a pressure-sensitive adhesive sheet for a warmer as a member constituting a bag body for enclosing a heating element in the warmer. A warmer comprising the adhesive member for a warmer according to any one of claims 1 to 9.

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