JP3759770B2

JP3759770B2 - An adhesive sheet for table tennis rackets used for bonding a table tennis racket substrate and rubber, a racket rubber in which this adhesive sheet is bonded to one side of the rubber, and a table tennis racket in which the substrate and rubber are bonded with the adhesive sheet, and Rubber bonding method for bonding to a substrate with the adhesive sheet

Info

Publication number: JP3759770B2
Application number: JP21107795A
Authority: JP
Inventors: 和久余田
Original assignee: Kyowa Ltd
Current assignee: Kyowa Ltd
Priority date: 1995-07-26
Filing date: 1995-07-26
Publication date: 2006-03-29
Anticipated expiration: 2015-07-26
Also published as: JPH0938258A

Description

【０００１】
【産業上の利用分野】
この発明は卓球ラケットに関する。詳しくは、卓球ラケットの基板とラバーとの貼り合わせに用いる接着シート，およびこの接着シートをラバーの片面に貼着したラケットラバー，および前記接着シートで基板とラバーを貼り合わせた卓球ラケット，および前記接着シートで基板にラバーを貼着する方法に関する。
【０００２】
【従来の技術】
従来、卓球ラケットの基板とラバーを貼り合わせる方法には、
▲１▼基板とラバーのいずれか一方または両方にゴム糊を塗って、ラバーを貼着する方法、
▲２▼芯材の両面に粘着剤を塗布した両面テープを用いて基板とゴムを貼り合わせる方法、
があった。
【０００３】
【発明が解決しようとする課題】
しかしながら、前記▲１▼のゴム糊を用いる方法では、溶剤臭が強いので狭い室内等で貼り合わせを行うとき施工者の健康を害しかねないという問題点があった。また貼り合わせ自体では均一に塗れないなどの貼り合わせ技術面での問題点もあった。さらに貼り替え作業がことの他困難であるという欠点もあるし、またこの種のゴム糊はシンナー遊びに使用され兼ねない恐れがあり、関係者の愁眉の種でもあった。
【０００４】
また、前記▲２▼の両面テープを用いて貼り合わせを行う場合は、前記したゴム糊を用いる方法の欠点は解消されるものの両面テープに芯材を用いているところから、ラバーの弾性を殺し、ピンポン球に対する反撥弾性が弱まり、ピンポン球に鋭いスピンがかけにくいなど、競技者から不評を買うことが多かった。
【０００５】
この発明は上記した一見二律背反時な問題点を解消しようとするもので、基板とラバーの貼り合わせに際して、溶剤臭がなく、均一な厚みの糊面を形成でき、貼り換えが容易でしかも反撥弾性を低くすることのない卓球ラケット用接着シートを得ることを目的とする。
【０００６】
【課題を解決するための手段】
この発明は、卓球ラケットの基板とラバーとの貼り合わせに際し、
▲１▼２種の粘着剤が実質的に無溶媒の状態で一体的に積層された粘着フィルムであって、
▲２▼ラケットラバーへの粘着力が５００ｇｆ／ｃｍ〜５０ｇｆ／ｃｍ、基板への粘着力が４５０ｇｆ／ｃｍ〜３５ｇｆ／ｃｍの粘着力を有しかつ基板に貼着される粘着力がラバーに貼着される粘着力よりも低い粘着力を有するような、厚み２０μｍ〜１００μｍの粘着フィルムを用いる、
という手段をとる。
【０００７】
【実施例】
以下、この発明の実施例を図１〜図３について説明する。
図１は接着シート１を示す縦断側面図であり、２は接着フィルムで第１粘着剤層２ａと第２粘着剤層２ｂとからなり、３は第１粘着剤層２ａに貼着される保護紙で表示層３ａを有し、４は離形紙である。
図２（イ）はラケットラバー５を示す斜視図であり、６はラバーで表層ラバー６ａと粘着フィルム２の第１粘着剤層２ａに貼着される内層ラバー６ｂとからなる。図２（ロ）はラケットラバー５Ａを示す斜視図であり、６Ａはラバーで内面が第１粘着剤層２ａに貼着される。なお、各図中図１と同一部分には同一符号を付して説明を省略する。
図３は卓球ラケット７を示す一部破断斜視図であり、８は卓球ラケット７の基板である。なお、図中図１および図２と同一部分には同一符号を付して説明を省略する。
【０００８】
まず、接着シートを図１について説明する。接着シート１は、卓球ラケット７の基板８とラバー６の貼り合わせに用いる粘着フィルム２を保護紙３と離形紙４との間に内在させたものであって、保護紙３は片面（非離形面）に使用説明などの表示が施され、他面（粘着フィルム側）にシリコーンなどの離形剤がコートされた厚みが８０μｍ〜１５０μｍ，剥離力が粘着フィルム側で５０ｇ／２０ｍｍ以下（７０℃×４時間荷重２０ｇ）の片面離形紙が用いられる。
【０００９】
離形紙４は、厚みが７０μｍ〜１５０μｍ，剥離力が粘着フィルム側で５０ｇ／２０ｍｍ以下（７０℃×４時間荷重２０ｇ）の両面または片面離形紙が用いられる。
【００１０】
接着シート１の大きさは、通常たて１５ｃｍ〜２５ｃｍ，横１５ｃｍ〜２５ｃｍの方形状で使用されるが、特にこの大きさ形状に限定されるものではなく、使用する卓球ラケット７の大きさ形状に準じて準備される。
【００１１】
一方、粘着フィルム２は、ラバー６側に貼着される第１粘着剤層２ａと、基板８側に貼着される第２粘着剤層２ｂの２層から構成され、両者は実質的に無溶媒な状態で一体的に積層形成されている。
【００１２】
ここにおいて、粘着フィルム２が第１粘着剤層２ａと第２粘着剤層２ｂとの２層で構成されていることは、この発明において特に重要である。また第１粘着剤層２ａと第２粘着剤層２ｂの粘着力およびその比もまた重要である。
【００１３】
即ち、粘着フィルム２を２層とする理由は、仮に１層だとすれば被着体が同一の場合、上層も下層もその粘着力は当然同じとなる。またこの発明の場合のように被着体が一方はラバー６，他方は基板８と異なる場合には、それぞれの被着体に応じて異なる粘着力を有するが、それぞれに望む粘着力にコントロールすることはできない。言い換えれば、今、基板８に対して適切な範囲の粘着力に粘着フィルム２を設計した場合には、ラバー６に対する粘着力は使用に供さない程度の弱い粘着力となるか，逆に必要以上に強い粘着力となる。逆にラバー６との粘着力を適切な範囲の設計した場合には、基板８に対する粘着力は極めて弱いものとなるか，必要以上に強すぎる粘着力となり、基板８への粘着力が弱すぎるためにおこるラバー６の剥離や，基板８への粘着力が強すぎるためにおこるラバー６の交換時に基板８に糊が残ったり，傷をつけるなどの不都合の原因となる。重量比が＞０．１であることを特徴とする像形成材料が提供される。
【００１４】
一般に、粘着剤の粘着力は被着体が木材の場合に比べゴム質の場合が小さい。
しかし、本用途ではラバー６に対する粘着力を木材に対する粘着力よりも強めてラバー６の貼り換えを容易にせんとするものである。このような場合、一層の粘着剤でこの目的を達することは到底不可能である。
【００１５】
この問題について、発明者らは鋭意研究の結果、ラバー６との貼り合わせに適合する粘着剤と基板８との貼り合わせに適合する粘着剤とを一体的に貼り合わせて、２層からなる粘着フィルム２を作ることにより、基板８とラバー６とに同時に最適な粘着力を有する粘着フィルム２を得ることに成功したのである。
【００１６】
即ち、実験によれば、ラバー６に対する第１粘着剤層２ａの粘着力は、５００ｇｆ/ｃｍ〜５０ｇｆ／ｃｍの範囲が好適である。これに対し、基板８に対する第２粘着剤層２ｂの粘着力は４５０ｇｆ／ｃｍ〜３５ｇｆ／ｃｍの範囲が好適である。そして両者の粘着力の比は、基板８に粘着剤を残さずにラバー６を剥離できる範囲として１０対９〜１０対７の範囲が最適である。
【００１７】
これらについて述べれば、ラバー６に貼着する第１粘着剤層２ａの粘着力で５００ｇｆ／ｃｍ以上，基板８に貼着する第２粘着剤層２ｂの粘着力で４５０ｇｆ／ｃｍ以上の強い粘着力は使用上不要であるばかりか、これらの粘着力を得んとすれば必要以上に両者の粘着剤の樹脂量を増やすか厚みを厚くしなければならず、ラバー６の弾性に影響して、スピンがかかりにくいなど競技上、悪い影響を与える。
一方、第１粘着剤層２ａの粘着力で５０ｇｆ／ｃｍ以下，第２粘着剤層２ｂの粘着力で３５ｇｆ／ｃｍ以下の粘着力の場合はラバー６および基板８に対する粘着力が弱すぎ、使用中のラバー６の剥離の原因となり好ましくない。
【００１８】
一方、第１粘着剤層２ａと第２粘着剤層２ｂとの粘着力の比が１０：９〜１０：７の範囲が良いとした理由は、ラバー６の貼り替えの容易性の点からとラバー６の剥離防止の点とから定められたものである。即ち、基板８に貼着する第２粘着剤層２ｂがラバー６に貼着する第１粘着剤層２ａの粘着力の９０％以上になる場合は、ラバー６の貼り換え時に粘着フィルム２が基板８に残ることになり好ましくないからである。一方、第２粘着剤層２ｂの粘着力がラバー６への粘着力に対して相対的に低くなりすぎる結果、使用中のラバー６の剥離の原因となる恐れがあり好ましくないからである。
【００１９】
一方、これらの粘着力を与える第１粘着剤層２ａおよび第２粘着剤層２ｂの粘着剤は、溶剤系，エマルジョン系，ＨＭ系のいずれの粘着剤も用いることができるが、使い易さ，安全性の面からエマルジョン系が好ましい。
【００２０】
次に、これらの粘着フィルム２の厚みは、第１粘着剤層２ａと第２粘着剤層２ｂとも共に１０μｍ〜５０μｍ，総厚みで２０μｍ〜１００μｍの範囲が好適である。
また、第１粘着剤層２ａと第２粘着剤層２ｂとの厚みの比は、１０：１０〜１０：８の範囲が望ましい。
【００２１】
粘着フィルム２の総厚みが２０μｍ〜１００μｍの範囲が好適な理由は、粘着フィルム２の厚みが２０μｍ以下の場合では粘着フィルム２が薄すぎて十分な粘着力が得られないし、また１００μｍ以上では逆に粘着フィルム２が厚すぎて卓球ラケット７の重量を重くする他，競技上微妙なスピンがかかりにくいなどの欠点を生じるからである。
【００２２】
さらに第１粘着剤層２ａと第２粘着剤層２ｂとの厚みが、１０対１０〜１０対８の範囲が好適である理由は、ラバー６を基板８へ貼着する場合第１粘着剤層２ａはラバー６の面へ，第２粘着剤層２ｂは基板８の面へ貼着する。一方、ラバー６を貼り換える場合は、基板８と第２粘着剤層２ｂとの間で剥がれることが望ましい。万一、ラバー６と第１粘着剤層２ａとの間で剥がれた場合、基板８に粘着フィルム２が残ることになり、粘着フィルム２を取り除くという余分な作業が必要となる。また、強固に粘着している場合は取り除くことが困難な場合もある。即ち、第２粘着剤層２ｂの厚みが第１粘着剤層２ａの厚みよりも厚い場合には、ラバー６の貼り換え時にラバー６と第２粘着剤層２ｂとの間で剥がれる恐れがあるからであり、第１粘着剤層２ａに対して第２粘着剤層２ｂが８割以下の厚みである場合は、ラバー６への粘着力に比して基板８への粘着力が不十分となり、繰り返し使用におけるラバー６の剥離の原因となりやすいからである。
【００２３】
一方、これら粘着剤の厚み調整は粘着剤の固形分差により行われる。例えば、粘着フィルム２の総厚みが９０μｍで、このうち第１粘着剤層２ａの厚みが５０μｍ，第２粘着剤層２ｂの厚みが４０μｍの場合、第１粘着剤層２ａの固形分は５５％〜６５％，第２粘着剤層２ｂのそれは４５％〜５５％のエマルジョン系粘着剤が選択される。
【００２４】
さらに、粘着フィルム２はその経時変化において安定した性能を有することが望ましい。即ち、今、仮に経時変化の大きい粘着剤を用いたとすれば、卓球ラケット７の性能が経時により変化することともなり、競技者への配慮を欠いたものとなるからである。この点について競技者と発明者が実際に使用して研究した結果、第１粘着剤層２ａおよび第２粘着剤層２ｂの粘着力の経時安定性の範囲は７０℃×３０日の経時変化でいずれも±５％の範囲を超えないものが良好であった。但し、ラバー６の貼り換えの点から第２粘着剤層２ｂの粘着力が、第１粘着剤層２ａの粘着力の９８％を超えないことが必要であることは言うまでもない。
【００２５】
次に、ラケットラバーを図２について説明する。図２はこの発明の粘着フィルム２を貼着したラケットラバーを示す図であって、（イ）は表層ラバー６ａと内層ラバー６ｂ（スポンジ）の２層からなるタイプのラケットラバー６でその内層ラバー６ｂに第１粘着剤層２ａを貼着したものであり、また（ロ）は１層からなるタイプのラケットラバー６Ａでその内面に第１粘着剤層２ａを貼着したものである。
【００２６】
このようにこの発明の粘着フィルム２をあらかじめ貼着したラバー６，６Ａは、基板８への貼着が容易でラバー貼り付けに失敗がないので、小児や初心者向けに最適である。
【００２７】
さらに、卓球ラケット７を図３について説明する。図３はこの発明の接着シート１を用いてラバー６と基板８を貼り合わせた卓球ラケット７を示す図である。
【００２８】
ここにおいて、この発明の接着シート１を用いて、ラバー６と基板８を貼り合わせる手順について説明する。
▲１▼まず、粘着フィルム２の第１粘着剤層２ａ上に貼り合わせた保護紙３を剥がした後、ラバー６を表層ラバー６ａが内側になるようにＵ字状に曲げ、その一端から順次粘着剤層２ａ上に貼着する。
▲２▼数分間放置後、はみ出している余分な粘着フィルム２および離形紙３を切り取る。
▲３▼次に、粘着フィルム２の第２粘着剤層２ｂ上に貼り合わせた離形紙４をラバー６を下にして、ゆっくりと剥がす。
▲４▼ラバー６の糊面が外側となるようにラバー６をＵ字状に曲げ、基板８の一端から基板８上に順次ラバー６を貼着する。
▲５▼エアがかんでいるような場合は、ローラー等でラバー６の表面より押えて均一に貼着する。
▲６▼次いで、基板８の縁に沿って基板８よりはみ出しているラバー６および粘着フィルム２をカットする。
【００２９】
尚、ラバー６を貼り換える場合には、古いラバー６を剥がし、基板８上をきれいにしてから上記▲１▼〜▲６▼の手順により貼り換える。
【００３０】
【実験例１】
▲１▼厚み９０μｍ，剥離力（２０℃×４時間荷重２０ｇ）３０ｇ／２０ｍｍの両面離形紙上に、固形分５０％のエマルジョン系の粘着剤を乾燥後の厚みが４０μｍとなるように塗工し乾燥する。（第２粘着剤層）
▲２▼表面に使用方法等を印刷した厚み１００μｍ，剥離力（２０℃×４時間荷重２０ｇ）２０ｇ／２０ｍｍの固形分６０％のエマルジョン系の粘着剤を乾燥後の厚みが５０μｍになるように塗工し乾燥する。（第１粘着剤層）
▲３▼上記▲１▼と▲２▼の粘着剤同志を貼り合わせ、１８０ｍｍ×１９０ｍｍ（糊面１７０ｍｍ×１７０ｍｍ）にカットする。
上記の手順で作成した接着シートを被着体をかえて常態と７０℃×３０日経時後について測定したところ表１の結果を得た。
【００３１】
【表１】

【００３２】
表１から明らかなように、ラバーに対する第１粘着剤層の粘着力は、基板に対する第２粘着剤層の粘着力よりも強いものが得られた。更にこれらの経時テストの結果も常態に比べ極めて安定した経時物性を有していた。
【００３３】
【実験例２】
実験例１で得られた接着シートを用いて基板とラバーを貼り合わせて実使用テストを４名で実施したところ表２の結果を得た。
【００３４】
【表２】

【００３５】
表２から明らかなように、この発明の接着シートを用いたラケットは使い易く，ピンポン球へのスピンもかかり易いし、またラバーの貼り換え時においても糊の残りがなく，貼り換えが容易なものであった。
【００３６】
【発明の効果】
以上説明したように、この発明の接着シートは、基板とラバーの貼り合わせに際しては、溶剤を用いることがないので安全であるし、また芯材のない接着シートであるのでラバーの弾性をころすことがないし、さらに糊の厚みを一定にすることができるのでラバーと基材の貼り合わせにおいて均一な厚みに仕上げることができると共に、ラバーの貼り換えに際しては、粘着剤が基板に残らないので貼り換えが極めて容易である等、数々の効果が得られる。また、この発明の接着シートを貼り合わせたラケットラバーは、離形紙を剥がして基板へ貼り合わせるだけでよいので、手軽で小児や初心者向けに最適であるという効果が得られる。さらに、この発明の接着シートを用いてラバーと基板を貼り合わせた卓球ラケットは、糊の厚みが均一でどの位置においてもピンポン球に対する反撥弾性を損なわないので、スピンをかけやすいなど競技用として用いることができるという効果が得られる。
【図面の簡単な説明】
【図１】この発明の接着シートを示す縦断側面図である。
【図２】この発明のラケットラバーを示す斜視図である。
【図３】この発明の卓球ラケットを示す一部破断斜視図である。
【符号の説明】
１．接着シート２．粘着フィルム２ａ．第１粘着剤層２ｂ．第２粘着剤層３．保護紙４．離形紙５，５Ａ．ラケットラバー６，６Ａ．ラバー６ａ．表層ラバー６ｂ．内層ラバー７．卓球ラケット８．基板[0001]
[Industrial application fields]
The present invention relates to a table tennis racket. Specifically, the adhesive sheet used for bonding the substrate of the table tennis racket and the rubber, the racket rubber in which the adhesive sheet is bonded to one side of the rubber, the table tennis racket in which the substrate and the rubber are bonded with the adhesive sheet, and the above The present invention relates to a method of attaching rubber to a substrate with an adhesive sheet.
[0002]
[Prior art]
Conventionally, the method of pasting the table tennis racket substrate and rubber together is:
(1) A method in which rubber is applied to one or both of the substrate and the rubber, and the rubber is adhered,
(2) A method of bonding a substrate and rubber using a double-sided tape in which an adhesive is applied to both sides of a core material,
was there.
[0003]
[Problems to be solved by the invention]
However, the method (1) using the rubber paste has a problem that the odor of the solvent is strong, so that it may impair the health of the installer when bonding is performed in a small room. In addition, there was a problem in the bonding technique such that the bonding itself could not be applied uniformly. In addition, there is a drawback that the re-sticking operation is difficult, and this type of rubber glue may be used for thinner play, and it was a seed for the people concerned.
[0004]
In addition, when laminating using the double-sided tape described in (2) above, although the disadvantages of the method using rubber glue are eliminated, the elasticity of the rubber is killed because the core material is used for the double-sided tape. The player often received unpopular opinions such as the rebound resilience to the ping-pong ball was weakened and it was difficult to apply a sharp spin to the ping-pong ball.
[0005]
This invention is intended to solve the above-mentioned seemingly contradictory problems. When the substrate and the rubber are bonded, there is no solvent odor, and it is possible to form a paste surface with a uniform thickness, which can be easily replaced and is repellent. An object is to obtain an adhesive sheet for table tennis rackets that does not lower the height.
[0006]
[Means for Solving the Problems]
This invention, when pasting the table tennis racket substrate and rubber,
(1) An adhesive film in which two types of adhesives are integrally laminated in a substantially solvent-free state,
(2) Adhesive strength to the racket rubber is 500 gf / cm to 50 gf / cm, adhesive strength to the substrate is 450 gf / cm to 35 gf / cm, and adhesive strength that is adhered to the substrate is applied to the rubber. Using an adhesive film having a thickness of 20 μm to 100 μm, which has an adhesive strength lower than the adhesive strength to be worn,
Take the means.
[0007]
【Example】
Embodiments of the present invention will be described below with reference to FIGS.
FIG. 1 is a longitudinal side view showing an adhesive sheet 1, wherein 2 is an adhesive film comprising a first pressure-sensitive adhesive layer 2a and a second pressure-sensitive adhesive layer 2b, and 3 is a protection adhered to the first pressure-sensitive adhesive layer 2a. The display layer 3a is made of paper, and 4 is a release paper.
FIG. 2 (a) is a perspective view showing the racket rubber 5, and 6 is a rubber comprising a surface layer rubber 6a and an inner layer rubber 6b adhered to the first adhesive layer 2a of the adhesive film 2. FIG. 2 (b) is a perspective view showing the racket rubber 5A. 6A is a rubber, and the inner surface is adhered to the first adhesive layer 2a. In addition, the same code | symbol is attached | subjected to the part same as FIG. 1 in each figure, and description is abbreviate | omitted.
FIG. 3 is a partially broken perspective view showing the table tennis racket 7, and 8 is a substrate of the table tennis racket 7. In the figure, the same parts as those in FIG. 1 and FIG.
[0008]
First, the adhesive sheet will be described with reference to FIG. The adhesive sheet 1 is a sheet in which an adhesive film 2 used for bonding the substrate 8 of the table tennis racket 7 and the rubber 6 is placed between the protective paper 3 and the release paper 4. The release surface is labeled with instructions for use, and the other side (adhesive film side) is coated with a release agent such as silicone. The thickness is 80 μm to 150 μm, and the peel force is 50 g / 20 mm or less on the adhesive film side ( A single-sided release paper of 70 ° C. × 4 hours load 20 g) is used.
[0009]
The release paper 4 is a double-sided or single-sided release paper having a thickness of 70 μm to 150 μm and a peeling force of 50 g / 20 mm or less (70 ° C. × 4 hours load 20 g) on the adhesive film side.
[0010]
The size of the adhesive sheet 1 is normally used in a square shape of 15 cm to 25 cm and 15 cm to 25 cm in width, but is not particularly limited to this size shape, and the size shape of the table tennis racket 7 to be used Prepared according to
[0011]
On the other hand, the adhesive film 2 is composed of two layers, a first adhesive layer 2a attached to the rubber 6 side and a second adhesive layer 2b attached to the substrate 8 side. They are integrally laminated in a solvent state.
[0012]
Here, it is particularly important in this invention that the pressure-sensitive adhesive film 2 is composed of two layers of a first pressure-sensitive adhesive layer 2a and a second pressure-sensitive adhesive layer 2b. Moreover, the adhesive force of the 1st adhesive layer 2a and the 2nd adhesive layer 2b and its ratio are also important.
[0013]
That is, the reason why the adhesive film 2 has two layers is that if the adherend is the same, the upper layer and the lower layer have the same adhesive force as a matter of course. Further, when the adherend is different from the rubber 6 and the other is the substrate 8 as in the case of the present invention, the adherend has a different adhesive strength depending on the adherend, but the desired adhesive strength is controlled for each. It is not possible. In other words, when the adhesive film 2 is designed to have an adhesive force in an appropriate range with respect to the substrate 8, the adhesive force to the rubber 6 is weak enough not to be used or vice versa. Stronger adhesion than above. On the contrary, when the adhesive strength with the rubber 6 is designed in an appropriate range, the adhesive strength to the substrate 8 becomes extremely weak or excessively strong, and the adhesive strength to the substrate 8 is too weak. For this reason, the rubber 6 is peeled off, and the adhesive force to the substrate 8 is too strong. This causes inconveniences such as glue remaining on the substrate 8 or scratching. An imaging material is provided wherein the weight ratio is> 0.1.
[0014]
In general, the adhesive strength of the adhesive is smaller when the adherend is rubber than when the adherend is wood.
However, in this application, the adhesive force to the rubber 6 is made stronger than the adhesive force to the wood so that the rubber 6 can be easily replaced. In such a case, it is impossible to achieve this purpose with a single adhesive.
[0015]
As a result of diligent research, the inventors of the present invention integrally bonded a pressure-sensitive adhesive suitable for bonding to the rubber 6 and a pressure-sensitive adhesive suitable for bonding to the substrate 8 to form a two-layer pressure-sensitive adhesive. By making the film 2, the adhesive film 2 having the optimum adhesive force on the substrate 8 and the rubber 6 at the same time was successfully obtained.
[0016]
That is, according to experiments, the adhesive strength of the first pressure-sensitive adhesive layer 2a to the rubber 6 is preferably in the range of 500 gf / cm to 50 gf / cm. On the other hand, the adhesive force of the second pressure-sensitive adhesive layer 2b to the substrate 8 is preferably in the range of 450 gf / cm to 35 gf / cm. The ratio of the adhesive strength between them is optimally in the range of 10: 9 to 10: 7 as the range in which the rubber 6 can be peeled without leaving the adhesive on the substrate 8.
[0017]
If these are described, the strong adhesive force of 450 gf / cm or more by the adhesive force of 500 gf / cm or more by the adhesive force of the 1st adhesive layer 2a stuck on the rubber 6 and the 2nd adhesive layer 2b stuck on the board | substrate 8 will be described. Is not necessary for use, and if these adhesive strengths are to be obtained, the resin amount of both adhesives must be increased or increased more than necessary, affecting the elasticity of the rubber 6, It has a bad influence on the competition, such as being hard to spin.
On the other hand, when the adhesive strength of the first adhesive layer 2a is 50 gf / cm or less and the adhesive strength of the second adhesive layer 2b is 35 gf / cm or less, the adhesive strength to the rubber 6 and the substrate 8 is too weak and used. This is not preferable because it causes peeling of the rubber 6 inside.
[0018]
On the other hand, the reason why the ratio of the adhesive strength between the first adhesive layer 2a and the second adhesive layer 2b is preferably in the range of 10: 9 to 10: 7 is that the rubber 6 can be easily replaced. This is determined from the point of preventing the rubber 6 from peeling off. That is, when the second adhesive layer 2b adhered to the substrate 8 is 90% or more of the adhesive strength of the first adhesive layer 2a adhered to the rubber 6, the adhesive film 2 is attached to the substrate when the rubber 6 is replaced. This is because it is not preferable. On the other hand, the adhesive strength of the second pressure-sensitive adhesive layer 2b is unfavorably caused as a result of the rubber 6 being in use being peeled off as a result of being too low relative to the adhesive strength to the rubber 6.
[0019]
On the other hand, as the pressure-sensitive adhesive for the first pressure-sensitive adhesive layer 2a and the second pressure-sensitive adhesive layer 2b that give these pressure-sensitive adhesive strengths, any of solvent-based, emulsion-based, and HM-based pressure-sensitive adhesives can be used. From the viewpoint of safety, an emulsion system is preferred.
[0020]
Next, the thickness of these pressure-sensitive adhesive films 2 is preferably 10 μm to 50 μm for both the first pressure-sensitive adhesive layer 2 a and the second pressure-sensitive adhesive layer 2 b and has a total thickness of 20 μm to 100 μm.
Moreover, as for the ratio of the thickness of the 1st adhesive layer 2a and the 2nd adhesive layer 2b, the range of 10: 10-10: 8 is desirable.
[0021]
The reason why the total thickness of the adhesive film 2 is preferably in the range of 20 μm to 100 μm is that when the thickness of the adhesive film 2 is 20 μm or less, the adhesive film 2 is too thin to obtain a sufficient adhesive force, and when the thickness is 100 μm or more, the opposite is true. This is because the pressure-sensitive adhesive film 2 is too thick to increase the weight of the table tennis racket 7 and causes a disadvantage that it is difficult to apply a delicate spin in the game.
[0022]
Furthermore, the reason why the thickness of the first pressure-sensitive adhesive layer 2a and the second pressure-sensitive adhesive layer 2b is preferably in the range of 10 to 10 to 10 to 8 is that when the rubber 6 is stuck to the substrate 8, the first pressure-sensitive adhesive layer 2a is attached to the surface of the rubber 6, and the second adhesive layer 2b is attached to the surface of the substrate 8. On the other hand, when the rubber 6 is replaced, it is desirable to peel off between the substrate 8 and the second pressure-sensitive adhesive layer 2b. In the unlikely event that the adhesive film 2 is peeled off between the rubber 6 and the first adhesive layer 2a, the adhesive film 2 remains on the substrate 8, and an extra work of removing the adhesive film 2 is required. Moreover, when it adheres firmly, it may be difficult to remove. That is, when the thickness of the second pressure-sensitive adhesive layer 2b is thicker than the thickness of the first pressure-sensitive adhesive layer 2a, there is a possibility that the rubber 6 and the second pressure-sensitive adhesive layer 2b are peeled off when the rubber 6 is replaced. When the second pressure-sensitive adhesive layer 2b has a thickness of 80% or less with respect to the first pressure-sensitive adhesive layer 2a, the pressure-sensitive adhesive force to the substrate 8 becomes insufficient compared to the pressure-sensitive adhesive force to the rubber 6, This is because the rubber 6 tends to be peeled off during repeated use.
[0023]
On the other hand, the thickness of these pressure-sensitive adhesives is adjusted by the difference in the solid content of the pressure-sensitive adhesive. For example, when the total thickness of the pressure-sensitive adhesive film 2 is 90 μm, and the thickness of the first pressure-sensitive adhesive layer 2a is 50 μm and the thickness of the second pressure-sensitive adhesive layer 2b is 40 μm, the solid content of the first pressure-sensitive adhesive layer 2a is 55%. ~ 65%, that of the second pressure-sensitive adhesive layer 2b is selected from 45% to 55% emulsion-based pressure-sensitive adhesive.
[0024]
Furthermore, it is desirable that the pressure-sensitive adhesive film 2 has a stable performance over time. That is, if an adhesive having a large change over time is used, the performance of the table tennis racket 7 changes with the passage of time, and the player is not considered. As a result of actual use and research by the athlete and the inventor on this point, the range of stability over time of the adhesive strength of the first pressure-sensitive adhesive layer 2a and the second pressure-sensitive adhesive layer 2b is a change with time of 70 ° C. × 30 days. Any of them did not exceed the range of ± 5%. However, it goes without saying that the adhesive force of the second pressure-sensitive adhesive layer 2b should not exceed 98% of the pressure-sensitive adhesive force of the first pressure-sensitive adhesive layer 2a from the viewpoint of reattaching the rubber 6.
[0025]
Next, the racket rubber will be described with reference to FIG. FIG. 2 is a view showing a racket rubber to which the adhesive film 2 of the present invention is attached. FIG. 2A is a type of racket rubber 6 having two layers of a surface rubber 6a and an inner rubber 6b (sponge). The first pressure-sensitive adhesive layer 2a is adhered to 6b, and (b) is a single-layer type racket rubber 6A having the first pressure-sensitive adhesive layer 2a adhered to the inner surface thereof.
[0026]
As described above, the rubbers 6 and 6A on which the adhesive film 2 of the present invention has been applied in advance are suitable for children and beginners because they can be easily applied to the substrate 8 and there is no failure in attaching the rubber.
[0027]
Further, the table tennis racket 7 will be described with reference to FIG. FIG. 3 is a view showing a table tennis racket 7 in which a rubber 6 and a substrate 8 are bonded using the adhesive sheet 1 of the present invention.
[0028]
Here, the procedure for bonding the rubber 6 and the substrate 8 using the adhesive sheet 1 of the present invention will be described.
(1) First, after peeling off the protective paper 3 bonded on the first pressure-sensitive adhesive layer 2a of the pressure-sensitive adhesive film 2, the rubber 6 is bent into a U shape so that the surface rubber 6a is inside, and sequentially from one end thereof. It sticks on the adhesive layer 2a.
{Circle around (2)} After leaving for several minutes, cut off the excess adhesive film 2 and release paper 3 protruding.
(3) Next, the release paper 4 bonded on the second pressure-sensitive adhesive layer 2b of the pressure-sensitive adhesive film 2 is slowly peeled off with the rubber 6 facing downward.
(4) The rubber 6 is bent in a U-shape so that the glue surface of the rubber 6 is on the outside, and the rubber 6 is stuck on the substrate 8 sequentially from one end of the substrate 8.
(5) If air is trapped, apply pressure evenly from the surface of the rubber 6 with a roller or the like.
(6) Next, the rubber 6 and the adhesive film 2 protruding from the substrate 8 along the edge of the substrate 8 are cut.
[0029]
When the rubber 6 is to be replaced, the old rubber 6 is peeled off and the substrate 8 is cleaned, and then replaced by the procedures (1) to (6).
[0030]
[Experiment 1]
(1) Coating on a double-sided release paper with a thickness of 90 μm and a peeling force (20 ° C. × 4 hours load of 20 g) of 30 g / 20 mm so that the thickness after drying is 40 μm. And dry. (Second adhesive layer)
(2) Thickness of 100μm with usage method printed on the surface, peeling force (20 ° C x 20 hours load 20g) 20g / 20mm solid content 60% solid content so that the thickness after drying is 50μm Apply and dry. (First adhesive layer)
(3) The above adhesives (1) and (2) are bonded together and cut into 180 mm × 190 mm (glue surface 170 mm × 170 mm).
When the adhesive sheet prepared by the above procedure was measured for the normal state after changing the adherend and after aging at 70 ° C. for 30 days, the results shown in Table 1 were obtained.
[0031]
[Table 1]

[0032]
As is clear from Table 1, the adhesive force of the first pressure-sensitive adhesive layer with respect to the rubber was stronger than that of the second pressure-sensitive adhesive layer with respect to the substrate. Furthermore, the results of these time-lapse tests also showed extremely stable physical properties over time as compared to normal conditions.
[0033]
[Experimental example 2]
Using the adhesive sheet obtained in Experimental Example 1, the substrate and rubber were bonded to each other and an actual use test was performed by four persons. The results shown in Table 2 were obtained.
[0034]
[Table 2]

[0035]
As can be seen from Table 2, the racket using the adhesive sheet of the present invention is easy to use, spins easily on the ping-pong ball, and there is no adhesive residue when the rubber is replaced, making it easy to replace It was a thing.
[0036]
【The invention's effect】
As described above, the adhesive sheet of the present invention is safe because it does not use a solvent when the substrate and the rubber are bonded together, and the adhesive sheet without the core material reduces the elasticity of the rubber. In addition, since the thickness of the glue can be made constant, the rubber and base material can be made to have a uniform thickness, and when the rubber is replaced, no adhesive remains on the substrate. Numerous effects can be obtained such as being extremely easy. Moreover, the racket rubber to which the adhesive sheet of the present invention is bonded only needs to peel off the release paper and bond it to the substrate, so that the effect that it is easy and optimal for children and beginners can be obtained. Further, the table tennis racket in which the rubber and the substrate are bonded together using the adhesive sheet of the present invention is used for competitions because the thickness of the paste is uniform and the resilience to the ping-pong ball is not impaired at any position, so that it is easy to apply a spin. The effect that it can be obtained.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view showing an adhesive sheet of the present invention.
FIG. 2 is a perspective view showing a racket rubber of the present invention.
FIG. 3 is a partially broken perspective view showing a table tennis racket according to the present invention.
[Explanation of symbols]
1. Adhesive sheet Adhesive film 2a. 1st adhesive layer 2b. 2. Second adhesive layer Protective paper Release paper 5,5A. Racket rubber 6,6A. Rubber 6a. Surface rubber 6b. Inner layer rubber Table tennis racket 8. substrate

Claims

A pressure-sensitive adhesive film comprising two layers, a first pressure-sensitive adhesive layer attached to a rubber and a second pressure-sensitive adhesive layer attached to a substrate; a protective paper attached on the first pressure-sensitive adhesive layer; 2 An adhesive sheet for table tennis rackets composed of a release paper affixed on an adhesive layer, wherein the first adhesive layer and the second adhesive layer constituting the adhesive film are substantially An adhesive sheet for table tennis rackets, which is integrally laminated in a solvent-free state.

On the first pressure-sensitive adhesive layer to be attached to the rubber, a single-sided release protective paper with a peel-off force of 50 gf / 20 mm or less, with indications such as usage instructions on one side and a release agent coated on the other side 2. The structure according to claim 1, wherein the second pressure-sensitive adhesive layer that is covered and adhered to the substrate is covered with a release paper having a peeling force of double-sided or single-sided release of 50 gf / 20 mm or less. Adhesive sheet for table tennis rackets.

2. The pressure-sensitive adhesive film according to claim 1, wherein the pressure-sensitive adhesive force of the first pressure-sensitive adhesive layer attached to the rubber is a pressure-sensitive adhesive film having a pressure-sensitive adhesive force larger than that of the second pressure-sensitive adhesive layer attached to the substrate. 2. Adhesive sheet for table tennis rackets.

The ratio of the adhesive force of the 1st adhesive layer stuck to a rubber | gum and the 2nd adhesive layer stuck to a board | substrate is the range of 10: 9-10: 7, It is characterized by the above-mentioned. The adhesive sheet for table tennis rackets according to any one of 3 above.

The adhesive force of the first adhesive layer attached to the rubber is in the range of 500 gf / cm to 50 gf / cm, and the adhesive force of the second adhesive layer attached to the substrate is 450 gf / cm to 35 gf / The adhesive sheet for table tennis rackets according to claim 4, which is an adhesive film having a range of cm.

The thickness of the 1st adhesive layer stuck on a rubber | gum and the 2nd adhesive layer stuck on a board | substrate is the range of 10 micrometers-50 micrometers, and total thickness is 20 micrometers-100 micrometers, It is characterized by the above-mentioned. The adhesive sheet for table tennis rackets according to any one of?

The ratio of the adhesive thickness between the first pressure-sensitive adhesive layer adhered to the rubber and the second pressure-sensitive adhesive layer adhered to the substrate is in the range of 10 to 10 to 10: 8. The adhesive sheet for table tennis rackets in any one of -6.

The rate of change in the adhesive strength of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer is within ± 5% as a function of change over time at 70 ° C. × 30 days. Adhesive sheet for table tennis rackets as described.

The 1st adhesive layer of Claims 1-8 is bonded together to the inner-layer rubber of the rubber, The racket rubber characterized by the above-mentioned.

The 1st adhesive layer of Claims 1-8 is bonded together on the inner surface of the rubber, The racket rubber characterized by the above-mentioned.

A table tennis racket, wherein a rubber and a substrate are bonded together using the adhesive sheet according to claim 1.

A table tennis racket, wherein the racket rubber according to claim 9 or 10 is bonded to a substrate.

(1) After peeling off the protective paper stuck on the first pressure-sensitive adhesive layer, the rubber surface layer is bent in a U-shape inside and stuck on the first pressure-sensitive adhesive layer sequentially from one end.
(2) Next, the protruding adhesive film and release paper are cut off.
(3) Next, the release paper stuck on the second pressure-sensitive adhesive layer of the pressure-sensitive adhesive film is slowly peeled off, and the rubber is bent in a U-shape so that the glue surface of the rubber is on the outside, and one end of the substrate After sticking more sequentially, cut the rubber and adhesive film protruding from the substrate along the edge of the substrate,
The method according to any one of (1) to (3) above, wherein rubber is attached to a substrate using the adhesive sheet according to any one of claims 1 to 8.