JP2004285243A - Pressure-sensitive adhesive sheet with peeling-detection function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure-sensitive adhesive sheet with peeling-detection function exhibiting peeling-display in more reliable and clear manner even when peeled at a low speed or peeled from an adherend with low adhesivity. <P>SOLUTION: This pressure-sensitive adhesive sheet comprises a base material layer 1 and a pressure-sensitive adhesive layer 2. The layer 1 comprises (1) a transparent or translucent support 4, (2) a peelable layer 5 arranged on a part of one surface of the support 4 and (3) a colored layer 6 laminated on the whole surface of the support 4 where the peelable layer 5 is arranged so as to cover the peelable layer 5, and the layer 2 comprises (4) a support 7 laminated on the colored layer 6 and (5) a pressure-sensitive adhesive layer 8 laminated on the support 7. The adhesive force between the peelable layer 5 and the support 4 is smaller than any of adhesive force between other layers, and even smaller than the adhesive force measured by pasting the pressure-sensitive layer 8 onto a polyethylene plate and peeling the layer 8 at an angle of 90°. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００４８】
【表２】
表２ ＰＥ板に対する剥離力と発現率

※比較例１は、１０００ｍｍ／分まで速度を上げても２．５［Ｎ／２５ｍｍ］以上にはならなかったため評価できなかった。
【００４９】
表１，２に記載した結果から明らかなように、実施例１の粘着シートは、接着力が２．０［Ｎ／２５ｍｍ］を越えると８０％以上の発現率を示しているが比較例１では同様の発現率を示すためには３．５［Ｎ／２５ｍｍ］を越える接着力を必要とする。即ち実施例の剥離表示の発現能力は、従来に比べて約２倍も向上している。なお、いずれのサンプルにおいても粘着剤などの残留は全く認められなかった。また、比較例１の剥離表示と実施例の剥離表示の明瞭さを比較すると、実施例の剥離表示の方がより優れていた。
【００５０】
【発明の効果】
本発明によれば、低速で剥離したり、接着性の低い被着体から剥離した場合でも、確実且つ明瞭に剥離表示を発現でき、被貼着物に痕跡を残留させない剥がし検知機能を有する粘着シートを提供することが出来る。
【図面の簡単な説明】
【図１】本発明の粘着シートにおける一実施例の断面図である。
【図２】従来技術の粘着シートの断面図である。
【図３】従来技術の粘着シートを被着体に貼着後、剥離した状態を示す断面図である。
【図４】本発明の一実施例の粘着シートを被着体に貼着後、剥離した状態を示す断面図である。
【図５】粘着シートの粘着層の９０°剥離伸び変形の測定の概略図である。
【符号の説明】
１：基材層
２：粘着層
３：剥離シート
４：基材層支持体
５：剥離層
６：着色層
７：接着層支持体
８：粘着剤層
９：粘着層
１０：剥離部
１１：被着体
１２：引張試験機チャック
ａ：９０°剥離伸び変形の測定における引き上げ距離
ｂ：９０°剥離伸び変形の測定における剥離距離
ｄ：９０°剥離伸び変形の測定における初期つかみ間隔
３ａ：剥離シート
４ａ：基材
５ａ：マーキング層
６ａ：固着色彩層
８ａ：粘着層
９ａ：非剥離層
１０ａ：剥離部[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a pressure-sensitive adhesive sheet having a peeling detection display function that allows a user to visually recognize a peeled proof for the purpose of detecting fraudulent activity or the like.
[0002]
[Prior art]
For example, in the storage and transportation of valuables such as jewelry and important documents such as important documents, apart from theft of storage containers such as safes and trunk cases that store these valuables and important items, items stored in storage containers It is also important to prevent illegal acts such as extraction, duplication (illegal duplication), tampering, and substitution. In particular, those who store or consign various items (not limited to valuables or important items) are required to take countermeasures against the above-mentioned misconduct due to the nature of the operation. However, such fraudulent acts were difficult to catch, and the items to be stored or consigned were returned to their proper places after being used for duplication, or were replaced with sophisticated counterfeits which were difficult to distinguish from stored items. In some cases, there is a problem that it is difficult to detect that there has been an illegal act. For example, in the temporary custody or consignment of travel suitcases, even if an employee other than an employee removes, duplicates (illegally duplicates), falsifies, or substitutes an article from the suitcase, it may occur. The suitcase may be returned to the user without noticing the wrongdoing, or the existence of the wrongdoing may be determined at the time of or after the return, resulting in an unexpected responsibility.
[0003]
Therefore, in recent years, as a sealing label for an opening of a container storing an article, a label having a function of forming a display proof of a peeling action when peeled from the container (peeling detection function) has been provided, It is used to determine whether a container has been illicitly opened. As this type of label (a label with a peeling detection function), for example, when the label is peeled from the container, a part remains on the container side, and a display (character, Sign, etc.). Further, as another type of label, a peeling-preventive pressure-sensitive adhesive sheet of a type in which a trace of a substance such as a pressure-sensitive adhesive does not remain on a material to be adhered is also known (see Patent Document 1).
[0004]
FIG. 2 shows the structure of a peeling-preventive pressure-sensitive adhesive sheet of the type described in Patent Document 1 in which no trace of a substance such as a pressure-sensitive adhesive remains on the article to be adhered. A base material 4a made of a transparent or translucent film-like material applicable to the production of a sealing tape or a sheet, and a material having a color and transparency matching the base material 4a and having adhesiveness between the base material 4a and the base material 4a. A marking layer 5a on which a peeling display is printed on the back side, a fixed color layer 6a in which the color covers the base material 4a and the marking layer 5a with an ink different from that of the base material 4a and the marking layer 5a, a non-peeling layer 9a, and an adhesive layer 8a. It has. By making the adhesive force of the adhesive layer 9a to the fixed color layer 6a larger than the adhesive force of the fixed color layer 6a to the marking layer 5a and smaller than the adhesive force of the fixed color layer 6a to the base material 4a, When peeled off, a peeling portion 10a is formed between the marking layer 5a and the fixed color layer 6a, and the peeling portion 10a clearly displays "peeled" or the like on the substrate surface (FIG. 3).
[0005]
[Patent Document 1]
Japanese Utility Model Registration No. 3068860
[0006]
[Problems to be solved by the invention]
However, when an attempt is made to manufacture a peeling-preventive pressure-sensitive adhesive sheet according to the above-mentioned known document, the ink for forming the marking layer 5a and the fixed color layer 6a is mixed at the interface to increase the adhesive strength. A considerable peeling stress was required in order to generate a peeling portion 10a between the layers of the fixed color layer 6a and to exhibit peeling display. Therefore, when peeling at a low speed or peeling from an adherend having low adhesiveness, the display may not be displayed. Further, when a pressure-sensitive adhesive having a high adhesive force is used in order to exhibit a peeling indication, the pressure-sensitive adhesive or ink may remain on the product at the time of peeling. Further, even when the peeling display can be developed, there is a disadvantage that the peeling display is hard to clearly appear.
[0007]
Therefore, the object of the present invention is to solve the above-mentioned problems and peel at a low speed, even when peeling from an adherend having low adhesiveness, after peeling, more reliably and clearly exhibit peeling display, and further at the time of peeling An object of the present invention is to provide a pressure-sensitive adhesive sheet with a peeling detection function without residual pressure-sensitive adhesive or the like.
[0008]
[Means for Solving the Problems]
In view of such circumstances, the present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, completed the present invention. That is, the present invention is a pressure-sensitive adhesive sheet having a peel-off detection function of displaying a peel-off indication visibly from the surface side as a proof that the film has been peeled off from the article when peeled off from the article. It has a structure in which a material layer 1 and an adhesive layer 2 are laminated, and the base material layer 1 further comprises:
(1) Transparent or translucent substrate layer support 4
(2) a release layer 5 provided on a part of one surface of the substrate layer support 4
(3) a colored layer 6 laminated on the entire surface or a part of the substrate layer support 4 so as to cover the release layer 5 on the surface of the substrate layer support 4 on which the release layer 5 is provided.
Having the adhesive layer 2
(4) Adhesive layer support 7 laminated on the colored layer 6
(5) The pressure-sensitive adhesive layer 8 laminated on the pressure-sensitive adhesive layer support 7
And the adhesive force (1) between the release layer 5 and the base layer support 4 is the adhesive force (2) between the release layer 5 and the colored layer 6, and the colored layer 6 and the substrate The adhesive strength of the adhesive layer 8 to the layer support 4 and the adhesive strength 4 of the colored layer 6 to the adhesive layer 2 are smaller than those of the adhesive layer 2, and the adhesive layer 8 is adhered to a polyethylene plate. The relationship between the adhesive force (5) when the 90 ° peeling is performed and the adhesive force (1) to (4) is (2) to (4)>(5)> (1). An object of the present invention is to provide an adhesive sheet with a peeling detection function.
[0009]
FIG. 1 shows the basic structure of the pressure-sensitive adhesive sheet with a peel detection function of the present invention (hereinafter, referred to as the pressure-sensitive adhesive sheet of the present invention). The pressure-sensitive adhesive sheet of FIG. 1 is a flexible transparent or translucent film-like substrate layer support having a release layer 5 that forms a peeling display when peeled off after being once attached to an article. 4, a colored layer 6 laminated so as to cover the whole or a part of the back surface side of the base material layer support 4 including on the release layer 5, and an adhesive layer 2 laminated on the back surface side of the colored layer 6. And a release sheet 3 for protecting the same. The coloring layer 6 may be laminated on the entire surface of the substrate layer support 4 or may be a part as long as the coloring layer 6 completely covers the release layer 5. The release sheet 3 is necessary when the pressure-sensitive adhesive sheet of the present invention is a single-sheet embodiment, but may not be provided when the pressure-sensitive adhesive sheet is manufactured in a roll-shaped (roll-shaped) embodiment. In the case of a roll-shaped embodiment, the surface of the substrate layer support 4, that is, the surface on which the release layer 5 and the colored layer 6 are not provided, may be subjected to a release treatment with a silicone resin or the like. preferable. When the pressure-sensitive adhesive sheet of the present invention is adhered to an article, and then the pressure-sensitive adhesive sheet is to be peeled off from the article, the peeling detection function operates to cause a peeling display to appear.
[0010]
By the way, in the above prior art, {adhesive strength of fixed color layer 6a to base material 4a} >> {adhesive strength of adhesive layer 9a to fixed color layer 6a} >> {adhesive strength of fixed color layer 6a to marking layer 5a} By peeling the pressure-sensitive adhesive sheet from the article, a peeling portion 10a is formed between the marking layer 5a and the fixed color layer 6a as shown in FIG. 3, and the fixed color layer 6a is formed in a predetermined shape. By internally breaking so as to separate from only the marking layer 5a, a predetermined shape, for example, a peeling display such as "OPEN VOID" appears on the outer surface of the adhesive sheet so as to be visible.
[0011]
On the other hand, in the pressure-sensitive adhesive sheet of the present invention, the adhesive force (1) of the release layer 5 to the base layer support 4 is the adhesive force (2) of the release layer 5 to the colored layer 6, and the base layer support When the adhesive force of the colored layer 6 to the colored layer 4, the adhesive force 4 of the adhesive layer 2 to the colored layer 4, and the adhesive layer 8 were adhered to a polyethylene plate and peeled at 90 ° When the sheet is peeled off from the adherend, as shown in FIG. 4, the peeling portion 10 is located between the peeling layer 5 and the base material layer support 4. Occurs. By causing interlayer destruction only in the part of the peeling layer 5 formed in a predetermined shape, a peeling display is visually made to appear in a predetermined shape. In such a peeling display, light incident from the surface of the base material layer support 4 (from the upper side in FIG. 4) passes through the base material layer support 4, and reflects light such as irregular reflection of light at the peeling portion 10. It appears when the state changes.
[0012]
By the way, according to the method of making the peeling display appear in the present invention, since the peeling portion 10 occurs just below the back surface of the base layer support 4, irregular reflection of light or the like occurs immediately below the base layer support 4. However, in the conventional method shown in FIG. 3, since the peeling portion 10a is formed below the marking layer 5a provided on the back surface of the substrate 4a, light transmitted through the substrate 4a further passes through the marking layer 5a. However, the light must be irregularly reflected at the peeling portion 10a and pass through the marking layer 5a and the base material 4a. Therefore, the amount of irregularly reflected light generated at the peeling portion 10a is significantly reduced. According to the method of making the peeling display appear in the present invention, such reduction of the reflected light is reduced, so that the peeling display is clearly and reliably displayed.
[0013]
Further, when an adhesive sheet is manufactured using a conventional appearance method of peeling display, the peeling portion 10a is generated between the marking layer 2a and the fixed color layer 6a. It is difficult to control the adhesive force because it mixes and increases the adhesive force. For this reason, when peeling off from an article, it is easy for the peeling display not to appear partially. Further, since the adhesive force between the marking layer 2a and the fixed color layer 6a is likely to be high, a considerable peeling stress is required in order to exhibit peeling display. When it is peeled off from the display, it is easy to cause inconvenience that the display does not appear. The conventional method of appearance of the peeling display has such a potential disadvantage. The pressure-sensitive adhesive sheet proposed by the present inventors that causes interfacial breakdown between the base material layer support 4 and the release layer 5 solves such inconvenience.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
(Substrate layer support 4)
The substrate layer support 4 used in the pressure-sensitive adhesive sheet of the present invention is not particularly limited, and for example, a plastic film such as polyolefin, polyester, polyvinyl chloride, and fluororesin can be used. Among them, a high-strength and inexpensive transparent or translucent biaxially oriented polypropylene or polyethylene terephthalate (PET) film is suitably selected. Above all, it is preferable to use an untreated polyethylene terephthalate film having a transparent or translucent surface on which the release layer 5 is formed, and it is particularly preferable to use a colorless and transparent polyethylene terephthalate film. Further, any other plastic film may be laminated on the opposite surface, and for the purpose of improving the adhesion of the printing ink and showing the peeling display more clearly, for example, an easy adhesion treatment or a mat treatment. May be performed. In particular, it is preferable to laminate a film whose surface has been subjected to a matting treatment so that the peeling display can be clearly seen. Further, since the pressure-sensitive adhesive sheet having the peeling detection display function does not remain on the article to be adhered, printing, signing, or stamping of a barcode or a management code is performed on the base material layer support 4 in order to prevent replacement. Alternatively, it can be performed on a film laminated on the base material layer support 4.
[0015]
The thickness of the base material layer support 4 is not particularly limited. However, if it is too thin, the stress at the time of peeling is dispersed to lower the lettering property, and if it is too thick, the rigidity is increased and it is difficult to deform. It is 300 μm, more preferably 38 to 100 μm.
[0016]
(Release layer 5)
The release layer 5 used in the pressure-sensitive adhesive sheet of the present invention does not exhibit a display if the adhesive force to the substrate layer support 4 is too high, and an unnecessary display due to a slight impact such as peeling of the release sheet 3 if the adhesive strength is too low. , The adhesive force (1) is preferably 0.02 [N / 25 mm] to 5 [N / 25 mm], and more preferably 0.1 [N / 25 mm] to 3 [N / 25 mm]. . The release layer 5 can be formed by using a method such as printing or by laminating the substrate layer support 4 as a release display pattern such as “VOID” or “opened”. In addition, the measurement of the adhesive force (1) and the following adhesive forces (2) to (5) are values measured by the following method and a method according thereto.
Preparation of a sample: An ink for a release layer 5 diluted to an appropriate concentration with a solvent to a 50 μm PET film was applied at about 2 μm with a bar coater, dried and aged, and then an adhesive film “UVPET” manufactured by Dainippon Ink and Chemicals, Ltd. "Transparent 50FL-YM" was stuck on the printing surface to produce a laminate sample of 25 mm x 100 mm. In the measurement of other interlayer adhesive strengths ((2) to (5)), a laminate sample was prepared by laminating the above-mentioned adhesive film on both sides of a sample in which layers whose adhesive strengths were to be measured were laminated.
-Tensile testing machine: Orientec Tensilon universal tensile testing machine RTA100
Measurement conditions: Measured after leaving at 23 ° C. and 50% RH for 1 hour. The PET film and the adhesive film were fixed on a chuck, and peeled up and down.
-Peeling speed: 300 mm / min
-Peeling angle: 90 degrees (T-peel)
[0017]
The material for forming the release layer 5 is not particularly limited, but may be appropriately adjusted in accordance with the material of the base layer support 4 to be used so that the adhesive force (1) falls within the above range. Adjust the type of resin, various additives, and the amount of application. For example, when the substrate layer support 4 is polyethylene terephthalate, it is preferably a transparent ink containing acryl as a main component, and cellulose acetate butyrate, styrene resin, etc. It is preferable to add and coat with a layer thickness of 1 to 3 μm. The color of the release layer 5 is not particularly limited, and may be colored with a coloring material, but is preferably colorless and transparent.
[0018]
(Colored layer 6)
The adhesive force {circle around (3)} of the coloring layer 6 to the base material layer support 4 is preferably a value exceeding 5 [N / 25 mm], more preferably 10 [N / 25 mm] or more. Further, the adhesive force (2) of the colored layer 6 to the release layer 5 needs to be larger than the adhesive force (1) of the release layer 5 to the base material layer support 4, and preferably exceeds 5 [N / 25 mm]. And more preferably 10 [N / 25 mm] or more. As a method for forming the colored layer 6, there are a method of printing or coating inks such as gravure ink and planographic / letterpress ink, and a method of coating metal by sputtering or vapor deposition.
[0019]
The material of the coloring layer 6 is not particularly limited, but when untreated PET is used as the base layer support 4, a solvent-based ink having high adhesion to PET is preferably used. . Examples of the resin component of the ink include a mixture of a vinyl chloride-vinyl acetate copolymer obtained by copolymerizing vinyl alcohol, a urethane resin, an acrylic resin, and nitrocellulose. The hydroxyl value is preferably about 1 to 10. Further, crosslinking can be performed to improve the adhesive strength to the film. In this case, it is preferable to use an isocyanate-based cross-linking agent in consideration of the adhesive strength with the adhesive layer thereunder.
[0020]
(Color material)
The coloring material used for the coloring layer 6 is not particularly limited, but known and commonly used pigments and dyes can be used. Among them, black is carbon black, white is titanium oxide, calcium carbonate, barium sulfate, yellow is yellow iron oxide, red is red iron, blue is ultramarine, navy blue, and silver is aluminum powder. In the case of pearl, mica titanium powder is preferred from the viewpoints of weather resistance, heat resistance, and dispersibility in ink resin.
[0021]
(Thickness of colored layer)
The colored layer 6 needs to have a certain thickness or more in order to provide concealment. On the other hand, if the ink layer is too thick, the transmission of the peeling force to the release layer 5 when the adhesive sheet is peeled becomes poor, and the expression of peeling display is reduced. Therefore, the thickness of the colored layer is preferably 1 to 4 μm, more preferably 1 to 2 μm.
[0022]
(Adhesive layer 2)
The adhesive layer 2 includes an adhesive layer support 7 laminated on the colored layer 6 and an adhesive layer 8 for attaching the adhesive sheet of the present invention to an article. An adhesive layer 9 that adheres to the coloring layer 6 may be provided between the bodies 7. When the adhesive layer 9 is not provided, the adhesive layer support 7 is directly adhered to the colored layer 6 by heat fusion or the like. The adhesive force (4) between the adhesive layer 9 and the colored layer 6, the adhesive force between the adhesive layer 6 and the adhesive layer support 7, and the adhesive force between the adhesive layer 8 and the adhesive layer support 7 are all the pressure-sensitive adhesive sheets of the present invention. Is preferably larger than 8 [N / 25 mm], more preferably 10 [N], so that the adhesive strength is sufficiently larger than the adhesive strength (5) when 90 ° peeling is performed by sticking to a polyethylene plate. N / 25 mm] or more.
[0023]
(Type of adhesive of the adhesive layer 8)
The type of the pressure-sensitive adhesive used for the pressure-sensitive adhesive layer 8 in FIG. 1 is not particularly limited, and can be appropriately selected from acrylic, rubber-based, and silicone-based pressure-sensitive adhesives. Is more preferably selected. In addition, when the adhesive force to the article is too low, the peeling display does not appear, and when it is too high, delamination occurs inside the pressure-sensitive adhesive sheet, and a part of the pressure-sensitive adhesive sheet such as the pressure-sensitive adhesive layer easily remains on the bonded article. To be in a specific range. The adhesive force of the pressure-sensitive adhesive sheet of the present invention to an article is defined as the adhesive force (5) to a polyethylene plate. That is, the adhesive strength (5) is expressed as the adhesive strength when the pressure-sensitive adhesive sheet of the present invention is adhered to a polyethylene plate and peeled at 90 °. The adhesive strength (5) is more than 2 [N / 25 mm] and 15 or less, more preferably 3 to 10 [N / 25 mm], and particularly preferably 3 to 8 [N / 25 mm].
[0024]
(Type of adhesive for adhesive layer 9)
The type of the adhesive used for the adhesive layer 9 is not particularly limited, and can be appropriately selected from acrylic, rubber, and silicone adhesives. Since the adhesive force (5) of the adhesive layer 9 to the colored layer 6 and the adhesive force of the adhesive layer 9 to the adhesive layer support 7 need to be higher than the adhesive force when the adhesive sheet of the present invention is peeled from the article, A so-called strong adhesive type pressure-sensitive adhesive or adhesive is more suitably selected. The higher the adhesive strength to each layer, the better, preferably a value exceeding 8 [N / 25 mm], more preferably a value of 10 [N / 25 mm] or more.
[0025]
As described above, the adhesive strength between the respective layers is described. The relationship between the adhesive strengths (1) to (5) in the pressure-sensitive adhesive sheet of the present invention is (2) to (4)>(5)> (1). Need to be. Further, as described above, the adhesive strength between the layers inside the adhesive layer 2 is set to be larger than the adhesive strength (5). By designing in this manner, the pressure-sensitive adhesive sheet of the present invention does not cause delamination within the pressure-sensitive adhesive sheet when peeled off from the article, and therefore does not leave a part of the pressure-sensitive adhesive sheet on the article, and the peeling section 10 is generated, and the pressure-sensitive adhesive sheet has a peeling detection function capable of clearly expressing the peeling display.
[0026]
(Tensile strength of adhesive layer 2)
The tensile strength of the pressure-sensitive adhesive layer 2 is preferably 1 [N / 10 mm] or more, and more preferably, for the purpose of increasing the reliability that a part of the pressure-sensitive adhesive layer 2 does not remain on the adherend. It is at least 2 [N / 10 mm], more preferably at least 4 [N / 10 mm].
In the present invention, the lower limit of the elongation and deformation and the tensile strength are important, and if these values are cleared, the upper limit of the tensile strength is not particularly problematic and is not particularly limited. In addition, the tensile strength of the adhesive layer 2 is defined as the tensile strength [N / 10 mm] when the interval between marked lines is 5 mm in the tensile strength test method of JIS-Z0237 (2000).
[0027]
(Adhesive layer support 7)
The pressure-sensitive adhesive layer 2 used in the pressure-sensitive adhesive sheet of the present invention preferably has a 90 ° peel elongation deformation of 2.5% or more. The pressure-sensitive adhesive layer 2 may have a single-layer structure of only a pressure-sensitive adhesive, or may have a multilayer structure as necessary. When the adhesive layer 2 has a multilayer structure, it is easy to realize a predetermined tensile strength (1 N / 10 mm or more) and a sufficient adhesive strength (8 [N / 25 mm]) to the base material layer 1.
[0028]
(90 ° peel elongation deformation)
The 90 ° peeling elongation deformation refers to the measurement of the 90 ° peel strength of a 20 mm wide adhesive layer 2 against a 90 ° test plate according to JIS-Z0237 (2000) in a 23 ° C atmosphere as shown in FIG. Accordingly, the peel length when the sample is pulled up by amm at a speed of 300 mm / min while maintaining the sample in the 90 ° direction with respect to the adherend from the position where the grip distance is dmm is defined as b, and is defined as a value given by the following equation.
90 ° peel extension deformation (%) = (ab) ÷ (b + d) × 100
Further, d = 0 mm, a = 20 mm, and the measurement of the peel distance was in 0.5 mm units.
[0029]
The pressure-sensitive adhesive sheet having the pressure-sensitive adhesive layer 2 having a 90 ° peeling elongation deformation of 2.5% or more is preferable because a peeling display can be more reliably exhibited when peeled. If the 90 ° peel elongation deformation of the adhesive layer 2 is 2.5% or more and the tensile strength is 1 [N / 10 mm] or more, a part of the adhesive layer does not remain on the article to be adhered, and the peeling detection is not performed. The display will be displayed reliably.
[0030]
The 90 ° peel elongation deformation of the adhesive layer 2 is preferably 5% or more, and more preferably 10% or more. The upper limit of the 90 ° peeling elongation deformation of the pressure-sensitive adhesive layer 2 used in the present invention is not particularly limited. However, in a pressure-sensitive adhesive sheet having a large deformation of the pressure-sensitive adhesive layer 2, when the pressure-sensitive adhesive sheet is peeled off from an object to be adhered, the pressure-sensitive adhesive layer 2 is stretched. Therefore, the adhesion between the pressure-sensitive adhesive layer 2 and the colored layer 6 is reduced, so that the content is preferably 900% or less, more preferably 400% or less, and further preferably 300% or less.
[0031]
(Type of adhesive layer support 7)
The pressure-sensitive adhesive layer support 7 of the pressure-sensitive adhesive sheet of the present invention is not particularly limited, but a material that is flexible and hard to break is suitably selected. Specifically, a single-layer or multilayer film containing LLDPE, LDPE, CPP, EVA, nylon, polyurethane, polyvinyl chloride or the like as a main component can be exemplified. Further, the surface may be subjected to a corona treatment or an easy-adhesion coating treatment or the like in order to improve adhesiveness, and may be subjected to coloring or design, printing or the like for the purpose of preventing forgery or the like. There may be. Further, additives such as a coloring agent and an antistatic agent can be added.
[0032]
(Thickness of adhesive layer support 7)
The thickness of the pressure-sensitive adhesive layer support 7 is not particularly limited, but generally too thin, the tensile strength is reduced, so that the film tends to be broken. Preferably it is 5 to 50 μm.
[0033]
(Release sheet 3)
In the pressure-sensitive adhesive sheet of the present invention, a release sheet 3 can be provided. The kind of the release sheet 3 is not limited, and a general release paper or a release film used for an adhesive sheet can be used. For example, a type in which polyethylene is laminated on both sides of kraft paper and silicone for release is applied on one side can be used, and a polyester film or a polypropylene film which has been subjected to a release treatment can also be used.
[0034]
(Lamination method of adhesive layer 2)
In the pressure-sensitive adhesive sheet of the present invention, the method of laminating the pressure-sensitive adhesive layer 2 is not particularly limited, but after forming the release layer 5 and the colored layer 6 on the base material layer support 4, the pressure-sensitive adhesive layer 2 is formed on the colored layer 6. A method of forming a laminated sheet by coating and drying, or applying and drying an adhesive or a pressure-sensitive adhesive to either the colored layer 6 or the pressure-sensitive adhesive layer 2 on the base layer 1 and the pressure-sensitive adhesive layer 2 on which the respective layers are laminated in advance. In addition, a method such as bonding using a device such as a heating laminator as needed can be exemplified. Further, there is an embodiment in which the pressure-sensitive adhesive layer 2 of the pressure-sensitive adhesive sheet has the adhesive layer 9, and the coloring layer 6 and the pressure-sensitive adhesive layer 2 are laminated via the adhesive layer 9.
[0035]
【Example】
Hereinafter, a specific description will be given with reference to examples.
[0036]
(Creation of base layer)
[Example 1]
(Creation of base layer)
As a base layer support 4, a 50 μm thick colorless and transparent PET film (“Lumilar TL” manufactured by Toray Industries Co., Ltd.) is not subjected to an easy adhesion treatment, and a release layer 5 is formed of polymethyl methacrylate (PMMA) and polymethacrylic acid. "VOID" is a transparent release ink ("MCS-5041D-No2" manufactured by Dainippon Ink and Chemicals, Inc.) containing a copolymer of ethyl as a main component and a solution of cellulose acetate butyrate and styrene resin in toluene and methyl ethyl ketone. Was printed by a gravure printing machine to form a release layer having a thickness of about 2 μm. Further, a blue gravure ink ("Univia A" manufactured by Dainippon Ink and Chemicals, Inc.) was applied as a colored layer 6 on the printed surface of the PET film and dried to obtain a base layer having a thickness of about 2 μm.
[0037]
In the substrate layer 1 thus obtained, the adhesive force (1) between the release ink and the PET film is 0.5 [N / 25 mm], and the adhesive force (2) between the release ink and Univia A is 8.9 [N / 25 mm]. As described above, the adhesive force (3) between the PET film and Univia A was 11.8 [N / 25 mm] or more. In the measurement of the adhesive strengths (2) and (3), peeling did not occur between the respective layers, but occurred between the adhesive film and the ink. The value of each adhesive force is the adhesive force between the pressure-sensitive adhesive film and the ink, and it is understood that the adhesive forces (2) and (3) are higher adhesive forces since they are not separated by receiving this stress.
[0038]
An LLDPE film (density: 0.916) having a thickness of 25 μm, which has been subjected to corona treatment on both sides in advance, is used as an adhesive layer support 7, and an acrylic pressure-sensitive adhesive is applied on one side so that the thickness after drying is 30 μm in advance. (2 parts by weight of Dainippon Ink and Chemicals Inc. isocyanate-based cross-linking agent "Varnock NC-40" was added to "Dai Nippon Ink and Chemicals" Quick Master SPS-1068), dried and laminated with a separator. An adhesive layer 8 was formed. Further, on the other surface of the pressure-sensitive adhesive layer support, an acrylic pressure-sensitive adhesive (“SK-1502” manufactured by Soken Chemical Co., Ltd. and “L-45” manufactured by Soken Chemical Co., Ltd.) were used as an adhesive layer with the substrate. .3 parts added) so as to have a thickness of 10 μm after drying, and then dried to form an adhesive layer 9 and adhere to the blue ink surface of the base material layer 1 to form a release sheet 3 on the adhesive layer 8. A pressure-sensitive adhesive sheet with a peel detection display function was prepared by laminating release paper (FPM-11) manufactured by Lintec Corporation.
[0039]
The adhesive strength of the pressure-sensitive adhesive sheet thus obtained to the polyethylene plate was 4.9 [N / 25 mm]. Further, the adhesive strength to the stainless steel plate was 5.3 [N / 25 mm].
[0040]
[Example 2]
Example 1 except that a transparent release ink ("TR-201" manufactured by Dainippon Ink and Chemicals, Inc.) composed of a solution of ethyl acetate, toluene and methyl ethyl ketone containing polymethyl methacrylate (PMMA) as a main component was used as the release ink. In the same manner as in the above, a substrate layer 1 and an adhesive sheet were obtained.
[0041]
In the substrate layer thus obtained, the adhesive force (1) between the release ink and the polyester film is 0.9 [N / 25 mm], and the adhesive force (2) between the release ink and Univia A is 8.9 [N / 25 mm] or more. The adhesive force (3) between the polyester film and Univia A was 11.8 [N / 25 mm] or more. The adhesive force of the pressure-sensitive adhesive sheet to the polyethylene plate was 4.9 [N / 25 mm], and the adhesive force to the stainless steel plate was 5.3 [N / 25 mm]. Incidentally, the adhesive strengths (2) and (3) could not be directly measured as in Example 1.
[0042]
[Comparative Example 1]
Using a commercially available non-transition type label (“SK-8801” manufactured by Seal King) having the structure shown in FIG. 2, the appearance of peeling display was confirmed. It was confirmed that destruction occurred between the marking layer 5 and the fixed color layer 6, and the peeling-off display was developed at the portion indicated by 10a in FIG. From the state of this destruction, the adhesive strength between the marking layer 5 and the fixed color layer 6 is lower than the adhesive strength between the pressure-sensitive adhesive sheet and the article, and lower than the adhesive strength between the marking layer 5 and the base material layer support 4. I understand. Also, it can be seen that the adhesive strength between the other layers is higher than the adhesive strength between the pressure-sensitive adhesive sheet and the article.
[0043]
[Comparative Example 2]
As a film of the base material layer support, Toyobo A-4100 having one surface subjected to easy adhesion treatment was used, and a release layer 5 was formed on the easy adhesion treatment surface of the film. A material layer and an adhesive sheet were obtained.
[0044]
In the substrate layer thus obtained, the adhesive force (1) between the release ink and the film of the substrate layer support is 9.0 [N / 25 mm] or more, and the adhesive force (2) between the release ink and Univia A is 8.9. [N / 25 mm] or more, and the adhesive force (3) between the film of the base material layer support and Univia A was 11.8 [N / 25 mm] or more. The adhesive force of the pressure-sensitive adhesive sheet to the polyethylene plate was 4.9 [N / 25 mm], and the adhesive force to the stainless steel plate was 5.3 [N / 25 mm].
[0045]
The pressure-sensitive adhesive sheets of Examples 1 and 2 and Comparative Examples 1 and 2 were tested by the following methods, and the evaluation results are shown in Tables 1 and 2.
[0046]
(Characteristic test)
Using a stainless steel plate (SUS) and a polyethylene plate (PE) as adherends, the prepared adhesive sheet is peeled off by 90 degrees from a 90-degree test plate of JIS-Z0237 (2000) to measure the adhesive strength. At this time, the peeling speed was gradually increased from 5 mm / min, and peeling was performed at a speed at which the adhesive force became 1.5, 2.0, 2.5, 3.0, 3.5, 4.0 [N / 25 mm]. The expression status of the display was visually confirmed.
A: 100% peeling display was developed.
：: 80% or more peeling display occurred.
Δ: 20% or more of peeling display occurred.
X: The appearance of peeling display was 20% or less.
Preparation of sample: The adhesive sheet was cut into a size of 25 × 120 mm, attached to a predetermined adherend (SUS, PE), and subjected to one reciprocating pressure with a 2 kg roller.
-Tensile testing machine: Orientec Tensilon universal tensile testing machine RTA100
Measurement conditions: Measured after standing at 23 ° C. and 50% RH for 20 to 40 minutes.
-Peeling speed: 5 to 1000 mm / min
・ Peel angle: 90 °
[0047]
[Table 1]
Table 1 Peeling force and development rate for SUS plate

[0048]
[Table 2]
Table 2 Peeling force and expression rate for PE plate

* Comparative Example 1 could not be evaluated because the speed did not exceed 2.5 [N / 25 mm] even when the speed was increased to 1000 mm / min.
[0049]
As is clear from the results described in Tables 1 and 2, the pressure-sensitive adhesive sheet of Example 1 exhibited an expression rate of 80% or more when the adhesive force exceeded 2.0 [N / 25 mm], but Comparative Example 1 Then, in order to exhibit the same expression rate, an adhesive force exceeding 3.5 [N / 25 mm] is required. That is, the ability to develop the peeling display of the embodiment is about twice as high as that of the related art. Note that no residue of the adhesive or the like was observed in any of the samples. When the clarity of the peeling display of Comparative Example 1 and the clarity of the peeling display of the example were compared, the peeling display of the example was more excellent.
[0050]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, even if it peels at a low speed or peels from an adherend with low adhesiveness, it can reliably and clearly exhibit a peeling display, and has a peel detection function that does not leave traces on the adherend. Can be provided.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of one embodiment of the pressure-sensitive adhesive sheet of the present invention.
FIG. 2 is a sectional view of a conventional pressure-sensitive adhesive sheet.
FIG. 3 is a cross-sectional view showing a state in which a conventional pressure-sensitive adhesive sheet has been peeled off after being adhered to an adherend.
FIG. 4 is a cross-sectional view showing a state in which the pressure-sensitive adhesive sheet of one embodiment of the present invention has been peeled off after being adhered to an adherend.
FIG. 5 is a schematic diagram of measurement of 90 ° peel elongation deformation of an adhesive layer of an adhesive sheet.
[Explanation of symbols]
1: Base material layer
2: Adhesive layer
3: Release sheet
4: substrate layer support
5: release layer
6: colored layer
7: adhesive layer support
8: Adhesive layer
9: Adhesive layer
10: peeling part
11: adherend
12: chuck for tensile tester
a: Pulling distance in measurement of 90 ° peeling elongation deformation
b: Peeling distance in measurement of 90 ° peeling elongation deformation
d: Initial grip distance in measurement of 90 ° peel elongation deformation
3a: release sheet
4a: substrate
5a: marking layer
6a: fixed color layer
8a: adhesive layer
9a: non-release layer
10a: peeling part

Claims (3)

A pressure-sensitive adhesive sheet having a peeling detection function of visually displaying a peeling indication that indicates that the product has been peeled off from the article when peeled off from the article, from the front side, wherein the pressure-sensitive adhesive sheet has a base layer 1 and a pressure-sensitive adhesive layer 2 is laminated, and the base material layer 1 further comprises
(1) Transparent or translucent substrate layer support 4
(2) a release layer 5 provided on a part of one surface of the substrate layer support 4
(3) a colored layer 6 laminated on the entire surface or a part of the substrate layer support 4 so as to cover the release layer 5 on the surface of the substrate layer support 4 on which the release layer 5 is provided.
Having the adhesive layer 2
(4) Adhesive layer support 7 laminated on the colored layer 6
(5) The pressure-sensitive adhesive layer 8 laminated on the pressure-sensitive adhesive layer support 7
And the adhesive force (1) between the release layer 5 and the base layer support 4 is the adhesive force (2) between the release layer 5 and the colored layer 6, and the colored layer 6 and the substrate The adhesive strength of the adhesive layer 8 to the layer support 4 and the adhesive strength 4 of the colored layer 6 to the adhesive layer 2 are smaller than those of the adhesive layer 2, and the adhesive layer 8 is adhered to a polyethylene plate. The relationship between the adhesive force (5) when the 90 ° peeling is performed and the adhesive force (1) to (4) is (2) to (4)>(5)> (1). Adhesive sheet with peel detection function. The pressure-sensitive adhesive sheet according to claim 1, wherein the pressure-sensitive adhesive layer (2) further includes an adhesive layer (9) between the colored layer (6) and the pressure-sensitive adhesive layer support (7). The pressure-sensitive adhesive sheet with a peeling detection function according to claim 1, wherein the 90 ° peeling elongation deformation of the pressure-sensitive adhesive layer support 7 is 2.5% or more. 4.

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