Temperature-sensitive pressure-sensitive adhesive

Abstract

To provide a temperature-sensitive pressure-sensitive adhesive which exhibits adhesive behavior causing a sudden increase in adhesive strength with a small temperature change over a temperature range higher than room temperature, and developing a maximum adhesive strength.MEANS FOR SOLVING THE PROBLEM: A temperature-sensitive pressure-sensitive adhesive composition contains a 4-methyl-1-pentene / α-olefin copolymer as an elastomer component. A pressure-sensitive adhesive sheet, in which a pressure-sensitive adhesive layer composed of the temperature-sensitive pressure-sensitive adhesive composition is provided on at least one surface of a substrate, exhibits a maximum adhesive strength to a BA-SUS plate in a temperature range of 30°C to 45°C. The pressure-sensitive adhesive sheet exhibits adhesive behavior with an adhesive strength increase gradient of 0.1 N / °C 10 mm or more between the adhesive strength at a temperature 3°C lower (T-3°C) or 5°C lower (T-5°C) than the temperature T°C corresponding to the expression of maximum adhesive strength, and the maximum adhesive strength.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a temperature-sensitive adhesive composition and an adhesive sheet having an adhesive layer formed from the composition, and relates to a temperature-sensitive adhesive composition and an adhesive sheet that exhibit a maximum adhesive force with a small temperature change in a temperature range of room temperature or higher.

Background Art

[0002] Temperature-sensitive adhesives whose adhesive force is controlled by heat and adhesive sheets using such adhesives in the adhesive layer are known. For example, a temperature-sensitive adhesive containing a side-chain crystallizable polymer and exhibiting an adhesive force at a temperature equal to or higher than the melting point of the side-chain crystalline polymer has been proposed. When the temperature-sensitive adhesive is cooled to a temperature below the melting point of the polymer, the adhesive force decreases due to crystallization of the side-chain crystalline polymer (see Patent Documents 1, 2, etc.). In addition, as a temperature-sensitive adhesive that can strongly adhere to a polyimide-based adherend at room temperature and whose adhesive force decreases at a temperature equal to or higher than the melting point of the temperature-sensitive resin and can be easily peeled off, a base resin and a carboxyl group-free side-chain crystalline polymer are contained, and the adhesive force to a polyimide-based adherend decreases at a temperature equal to or higher than the melting point of the carboxyl group-free side-chain crystalline polymer. A temperature-sensitive adhesive has been proposed (Patent Document 3). Furthermore, there has been proposed a temperature-sensitive adhesive sheet having an adhesive layer formed from an adhesive composition containing a (meth)acrylate polymer (A), a crosslinking agent (B), and a polyrotaxane compound (C), having an adhesive force to glass at 20°C of less than 1.5 N / 25 mm and an adhesive force to glass at 80°C of 2.0 N / 25 mm or more (Patent Document 4).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

[0004] The present invention provides a temperature-sensitive pressure-sensitive adhesive that exhibits an adhesive behavior in which the adhesive force rapidly increases with a small temperature change and exhibits a maximum adhesive force in a temperature range of room temperature or higher. [Means for Solving the Problems]

[0005] That is, the present invention is directed to the following temperature-sensitive pressure-sensitive adhesive composition and adhesive sheet. [1] A temperature-sensitive pressure-sensitive adhesive composition containing a 4-methyl-1-pentene·α-olefin copolymer as an elastomer component, An adhesive sheet provided with an adhesive layer made of the temperature-sensitive pressure-sensitive adhesive composition on at least one surface of a base material exhibits a maximum adhesive force with respect to a BA-SUS plate in a temperature range of 30 to 45°C, An adhesive composition that exhibits an adhesive behavior in which the increase gradient of the adhesive force is 0.1 N / °C·10 mm or more between the value of the adhesive force at a temperature 3°C lower (T - 3°C) or 5°C lower (T - 5°C) than the temperature T°C at which the maximum adhesive force is exhibited and the value of the maximum adhesive force. [2] The adhesive composition according to [1], wherein the value of the maximum adhesive force with respect to the BA-SUS plate is 1 N / 10 mm or more. [3] The adhesive composition according to [1], wherein the value of the maximum adhesive force with respect to the BA-SUS plate is 2 N / 10 mm or more. [4] The pressure-sensitive adhesive composition according to [1], wherein the 4-methyl-1-pentene·α-olefin copolymer contains a unit structure derived from 4-methyl-1-pentene in a proportion of 70 mol% to 90 mol%, a unit structure derived from an α-olefin having 2 or 3 carbon atoms in a proportion of 10 mol% to 30 mol%, and still other unit structures in a proportion of 0 to 10 mol% (however, the total of all unit structures is 100 mol%). [5] The pressure-sensitive adhesive composition according to [1], further containing a tackifier resin and a softening agent. [6] The pressure-sensitive adhesive composition according to [5], wherein the tackifier resin is at least one selected from the group consisting of aliphatic hydrocarbon resins, aromatic-modified terpene resins, and alicyclic hydrogenated petroleum resins. [7] The pressure-sensitive adhesive composition according to [5], wherein the softening agent is at least one selected from the group consisting of oils, waxes, and polybutene. [8] An adhesive sheet having a base material and an adhesive layer formed from the pressure-sensitive adhesive composition according to any one of [1] to [7] on at least one surface of the base material. [Advantages of the Invention]

[0006] According to the present invention, there can be provided a temperature-sensitive pressure-sensitive adhesive composition and an adhesive sheet which exhibit an adhesive behavior in which the adhesive force rapidly increases with a small temperature change such as 3°C or 5°C in a temperature range of room temperature or higher, and exhibit a maximum adhesive force in a temperature range of 30 to 45°C. [Brief Description of the Drawings]

[0007]

Figure 1

Figure 2

[0008] [Thermosensitive Adhesive Composition] The thermosensitive adhesive composition according to the present invention contains a polyolefin elastomer, specifically, a 4-methyl-1-pentene·α-olefin copolymer.

[0009] The above 4-methyl-1-pentene·α-olefin copolymer may contain, for example, 70 mol% to 90 mol% of a unit structure derived from 4-methyl-1-pentene and 10 mol% to 30 mol% of a unit structure derived from an α-olefin having 2 or 3 carbon atoms. Further, the copolymer may further contain a unit structure derived from an α-olefin having 4 to 20 carbon atoms other than 4-methyl-1-pentene at a ratio of 10 mol% or less (note that the total of all unit structures is 100 mol%).

[0010] The ratio of the unit structure derived from 4-methyl-1-pentene in the above 4-methyl-1-pentene·α-olefin copolymer can be, for example, 72 mol% to 89 mol%, or 72 mol% to 85 mol%. Also, the ratio of the unit structure derived from an α-olefin having 2 or 3 carbon atoms in the above 4-methyl-1-pentene·α-olefin copolymer can be, for example, 11 mol% to 28 mol%, or 15 mol% to 28 mol%.

[0011] Examples of the α-olefins having 4 to 20 carbon atoms other than 4-methyl-1-pentene include linear or branched α-olefins, cyclic olefins, aromatic vinyl compounds, conjugated dienes, non-conjugated polyenes, functional vinyl compounds, etc. Examples of the functionalized vinyl compounds include hydroxy group-containing olefins; halogenated olefins; unsaturated carboxylic acids; unsaturated amines; unsaturated acid anhydrides; halides of the above unsaturated carboxylic acids; unsaturated epoxy compounds, etc. Among these, examples of the α-olefin having 4 to 20 carbon atoms include at least one selected from the group consisting of 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, vinylcyclohexane, and styrene. When the 4-methyl-1-pentene·α-olefin copolymer contains a unit structure derived from the α-olefin having 4 to 20 carbon atoms, the unit structure derived from the α-olefin having 4 to 20 carbon atoms may contain only one kind or may contain two or more kinds. In addition, the proportion of the unit structure derived from the α-olefin having 4 to 20 carbon atoms in the 4-methyl-1-pentene·α-olefin copolymer can be, for example, 5 mol% or less, 3 mol% or less, and can be 1 mol% or less, and an embodiment not containing the unit structure can also be adopted.

[0012] As the 4-methyl-1-pentene·α-olefin copolymer, commercially available products can be used, and for example, Absortmer (registered trademark) EP-1001, EP-1013, etc. manufactured by Mitsui Chemicals, Inc. can be preferably used.

[0013] The thermosensitive pressure-sensitive adhesive composition according to the present invention may further contain a tackifier resin. Adhesive imparting resins generally include rosin resins such as gum rosin, tall oil rosin, wood rosin, disproportionated rosin, polymerized rosin, etc.; rosin ester resins such as glycerin esters and pentaerythritol esters of these rosins; and rosin-based resins such as hydrogenated products of these; terpene resins, hydrocarbon-modified terpene resins, aromatic-modified terpene resins, terpene-based resins such as hydrogenated products of these; terpene phenol resins, terpene phenol-based resins such as hydrogenated products of terpene phenol resins; aliphatic petroleum resins, alicyclic petroleum resins, aromatic petroleum resins, copolymerized petroleum resins, dicyclopentadiene-based petroleum resins, pure monomer-based petroleum resins, petroleum-based resins (hydrocarbon resins) such as hydrogenated products of these; styrene-based resins, coumarone indene-based resins, alkylphenol-based resins, xylene-based resins, dammar, copal, shellac, etc. Specific examples can be given. In the present invention, from the viewpoint of compatibility with the above 4-methyl-1-pentene·α-olefin copolymer, for example, aliphatic hydrocarbon resins, aromatic-modified terpene resins, alicyclic hydrogenated petroleum resins, etc. can be used. Also, adhesive imparting resins other than these may be blended as long as the effects of the present invention are not impaired.

[0014] Commercially available products can be used as the adhesive imparting resin. Examples of commercially available products of the aliphatic hydrocarbon resin include Quintone (registered trademark) A100, B170, K100, M100, R100, C200S, etc. manufactured by Nippon Zeon Co., Ltd. Examples of commercially available products of the aromatic-modified terpene resin include YS Resin TO series manufactured by Yasuhara Chemical Co., Ltd. can be mentioned. Examples of commercially available products of the alicyclic hydrogenated petroleum resin include Alcon (registered trademark) P-90, P-100, etc. manufactured by Arakawa Chemical Industries, Ltd. These adhesive imparting resins can be used alone or in combination of two or more. The pressure-sensitive adhesive resin can be blended in a proportion of, for example, 30 to 200 parts by mass, or 30 to 150 parts by mass, based on 100 parts by mass of the 4-methyl-1-pentene·α-olefin copolymer.

[0015] A softening agent can be further blended into the pressure-sensitive adhesive composition according to the present invention as needed. The softening agent has a function of adjusting the adhesiveness of the pressure-sensitive adhesive at low temperatures. Examples include oils such as paraffin oil and naphthene oil; waxes such as paraffin wax; and liquid polybutene (low molecular weight polybutene) with an average molecular weight of about 200 to 5000. The softening agent can be blended in a proportion of, for example, 20 to 80 parts by mass, based on 100 parts by mass of the 4-methyl-1-pentene·α-olefin copolymer.

[0016] In addition to the above components, other components such as plasticizers, inorganic fillers such as calcium carbonate and silica, anti-aging agents, vulcanization accelerators, thickeners, surfactants, preservatives, defoaming agents, and dispersants can be appropriately blended into the pressure-sensitive adhesive composition according to the present invention.

[0017] <Adhesive behavior> The temperature-sensitive pressure-sensitive adhesive composition of the present invention exhibits characteristic adhesive behavior in a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer made of the composition provided on at least one surface of a substrate. That is, the above pressure-sensitive adhesive sheet exhibits a maximum adhesive force to a BA-SUS plate in a temperature range of 30 to 45°C, and at that time, shows an adhesive behavior in which a maximum adhesive force is exhibited with a small temperature change. Specifically, between the value of the adhesive force at a temperature 3°C lower (T - 3°C) or 5°C lower (T - 5°C) than the temperature T°C at which the maximum adhesive force is exhibited and the value of the maximum adhesive force, it shows an adhesive behavior in which the increase gradient of the adhesive force is 0.1 N / °C·10 mm or more. By showing such adhesive behavior, the temperature-sensitive pressure-sensitive adhesive composition according to the present invention becomes a pressure-sensitive adhesive composition that exhibits an adhesive force near the skin temperature of a human or the like having a temperature higher than room temperature, and shows a behavior of peeling off when the ambient environmental temperature decreases. In the above-mentioned adhesion behavior, the value of the maximum adhesive force to the BA-SUS plate is, for example, 1 N / 10 mm or more, and can be, for example, 2 N / 10 mm or more.

[0018] [Adhesive sheet] The present invention also targets an adhesive sheet having a base material and an adhesive layer formed from the above-mentioned temperature-sensitive adhesive composition on at least one surface of the base material. The adherend and application of the adhesive sheet are not particularly limited. For example, an adhesive sheet as an industrial process film, an adhesive tape, an adhesive sheet and an adhesive tape for general use, and a so-called patch having the human skin or the like as an adherend can be applied to various applications.

[0019] Examples of the above-mentioned base material (also referred to as a support) include a film, a sheet, a non-woven fabric, Japanese paper, a cotton cloth, a knitted fabric, a woven fabric, a laminate composite of a non-woven fabric and a film, and the like. These base materials can be appropriately selected according to the application of the adhesive sheet. Examples of the materials of these base materials include natural materials such as cotton (cotton), silk, hemp, and paper; polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, polyamides, polyimides, polyurethanes, polycarbonates, ethylene vinyl acetate copolymers, ethylene ethyl acrylate copolymers, ethylene polypropylene copolymers, and synthetic resins such as polyvinyl chloride. The base material may have either a single-layer structure or a multilayer structure. The thickness of the base material is, for example, 5 to 500 μm. In order to enhance the adhesion to the adhesive layer, the base material may be surface-treated on the surface where the adhesive layer is provided. Examples of the surface treatment include corona treatment, plasma treatment, blast treatment, chemical etching treatment, primer treatment, and the like.

[0020] The adhesive layer in the adhesive sheet according to the present invention can be formed by, for example, applying the above-mentioned adhesive composition on at least one surface of the above-mentioned base material. The method for forming the adhesive layer is not particularly limited. For example, the solvent method (dissolved in an organic solvent and coated), the ointment coating method (operating with as little heating as possible in the mixing and drying processes), the emulsion method (dissolved in an aqueous solvent and coated), the hot melt method, the calender method, etc., which are conventional well-known methods for manufacturing general adhesive sheets and patches, can be used. For example, the adhesive layer can be formed by supplying the adhesive composition to one upper surface of the base material (support) or the release liner described later by methods such as the coating method or the extrusion molding method. Also, it can be manufactured by supplying the adhesive between the base material and the release liner described later, or by co-extrusion molding the base material and the adhesive layer.

[0021] For example, as the coating means for coating the above-mentioned adhesive composition on the base material, an applicator, a coater, etc. can be mentioned. Examples of the coater include a knife coater, a roll coater, a calender coater, a comma coater, a gravure coater, a rod coater, etc.

[0022] The thickness of the adhesive layer can be, for example, 5 to 60 μm, or 10 to 60 μm, or 10 to 50 μm.

[0023] When the adhesive layer is laminated on both sides of the base material, as long as one-sided adhesive layer is made of the above-mentioned adhesive composition, the adhesive layer on the other side is not particularly limited. When the adhesive layer on the other side is composed of, for example, an adhesive layer made of the above-mentioned adhesive composition, its composition may be the same as or different from the composition of the adhesive layer on one side. Also, the adhesive layer on the other side can be composed of, for example, an adhesive layer made of a pressure-sensitive adhesive. Examples of the pressure-sensitive adhesive include natural rubber adhesives, synthetic rubber adhesives, styrene / butadiene latex-based adhesives, acrylic adhesives, etc. When the adhesive layer is laminated on both sides of the base material, the thickness of the adhesive layer on one side and the thickness of the adhesive layer on the other side may be the same or different.

[0024] In the pressure-sensitive adhesive sheet according to the present invention, a release film (also referred to as a separator, release liner, etc.) may be laminated on the pressure-sensitive adhesive layer. As the release film, those commonly used in the technical fields such as pressure-sensitive adhesive sheets and adhesives can be used. For example, a release agent having release performance such as a silicone resin or a fluororesin is applied to the surface of a film made of polyethylene terephthalate or the like. The thickness of the release film is preferably 5 to 500 μm, more preferably 25 to 250 μm. The release film may be peeled off when the pressure-sensitive adhesive sheet is used.

[0025] As described above, the temperature-sensitive pressure-sensitive adhesive composition according to the present invention exhibits a maximum adhesive force with a small temperature change and shows a behavior of peeling off when the ambient temperature decreases. Therefore, for example, when this is used as a pressure-sensitive adhesive sheet, it can be expected to be applied as a process film in the manufacture of electronic materials such as semiconductor manufacturing processes. In addition, from the viewpoint of exhibiting the above-described adhesive behavior in a temperature range of 30 to 45 ° C, which is from room temperature to slightly higher than room temperature, after being attached to the human skin (around 36 ° C), it can be easily peeled off without pain by slightly cooling the skin. Applications for adhesives with reduced pain can also be expected. Furthermore, applications for attaching to an adherend before the temperature of the finger is transmitted to the pressure-sensitive adhesive composition, for example, It can also be expected to be developed for medical applications such as surgery, where it is attached to the target affected area (such as the skin) without sticking to the finger.

Examples

[0026] Examples will be given below to explain the present invention in more detail, but the present invention is not limited to these examples.

[0027] <Preparation of Pressure-Sensitive Adhesive Composition and Production of Pressure-Sensitive Adhesive Sheet> According to the formulations shown in Tables 2 to 3, each component was mixed to prepare the temperature-sensitive pressure-sensitive adhesive compositions of Examples 1 to 13. The adhesive layer-forming compositions of Examples 1 to 13 had a coating amount per unit area of 15 to 40 g / m 2It was applied to a support which is a base material (refer to Table 1 and Tables 2 to 3) so as to form an adhesive layer (with a thickness of 15 to 40 μm) (applied to the corona-treated surface (PET) or the primer layer (NK350-PET)). Note that the blending ratios of the adhesive compositions shown in Tables 2 to 3 are the solid ratios obtained by removing the solvent (here, toluene) from the adhesive solution. Furthermore, a release film which is a separator (polyethylene terephthalate with silicone treatment, thickness 25 μm) was laminated on the exposed surface of the formed adhesive layer to obtain a laminate in which the base material, the adhesive layer, and the separator were laminated in this order. The laminate was cut with a cutting machine to obtain an adhesive sheet (adhesive tape: width 20 mm), which was used for the adhesive force measurement test described later. Note that the separator is removed at the time of each measurement described later. In the following description, the example numbers of the adhesive compositions shall also be treated as the example numbers of the adhesive sheets produced using them and the evaluation of their adhesive forces. The details of each component and the support used are shown in Table 1.

[0028]

Table 1

[0029] As reference examples, two types of temperature-sensitive adhesive sheets manufactured by Nitto Denko Corporation (Interimer TM Tape Cool-off type Plafix, product numbers: CS2325NA2 (Reference Example 1: NA2), CS2325NA4 (Reference Example 2: NA4)) were used and subjected to the adhesive force measurement test described later.

[0030] <Adhesive force measurement test> The adhesive forces of the adhesive sheets of Examples 1 to 13 and the adhesive sheets of Reference Examples 1 and 2 were measured in accordance with JIS Z0237. Specifically, first, the above-mentioned adhesive sheet was cut as needed to obtain a strip-shaped adhesive force measurement test sample with a width of 20 mm. The test sample, the adherend BA-SUS plate, and the pressure roller used in the test were allowed to stand for 120 minutes or more at each predetermined temperature (adhesive force measurement temperature: 20°C to 55°C) shown in Tables 2 to 3 to equalize the temperature. Thereafter, in the said predetermined temperature environment, the test sample was attached to the BA-SUS plate by reciprocating it 2 times at a speed of 300 mm / min with a 2 kg rubber roll. Thereafter, in the said predetermined temperature environment, within 1 minute after attachment, the test sample was peeled off from the BA-SUS plate under the conditions of a peeling angle of 180° and a peeling speed of 300 mm / min, and the adhesive strength (N / 20 mm) was measured. The obtained measured value was divided by 2 to convert it to the adhesive strength (N / 10 mm) for a width of 10 mm. The obtained results are shown in Tables 2 to 3.

[0031] Also shown in Tables 2 and 3 are, for the pressure-sensitive adhesive sheets of Examples 1 to 13 and Comparative Examples 1 and 2, the maximum value of the adhesive strength (maximum adhesive strength: N / 10 mm) in the temperature range of 30 to 45°C, and the value of the adhesive strength at a temperature 3°C lower (T - 3°C) or 5°C lower (T - 5°C) than the temperature T°C at which the maximum adhesive strength is exhibited, together with the increase gradient (ratio of the increase in adhesive strength with respect to temperature) between the value of the adhesive strength at that temperature and the maximum adhesive strength (the temperature range [°C] and the temperature gradient [N / °C·10 mm] between temperature T°C and (T - 3)°C are shown as "adhesive strength (between two points) increase gradient ±3°C", and the temperature range [°C] and the temperature gradient [N / °C·10 mm] between temperature T°C and (T - 5)°C are shown as "adhesive strength (between two points) increase gradient ±5°C", respectively). Further, the adhesion behavior (change in adhesive strength with respect to temperature change) of the pressure-sensitive adhesive sheets of Example 1 and Comparative Examples 1 and 2 is shown in FIG. 1, and the adhesion behavior (change in adhesive strength with respect to temperature change) of the pressure-sensitive adhesive sheets of Example 3 and Comparative Examples 1 and 2 is shown in FIG. 2, respectively.

[0032] [Table 2]

[0033] [Table 3]

[0034] As shown in Table 2, the pressure-sensitive adhesive sheets of Examples 1 to 8 exhibit a maximum adhesive force with respect to the BA-SUS plate in the temperature range of 30 to 45°C, and the adhesive force value at a temperature 3°C lower (T - 3°C) (Examples 3 and 4) or 5°C lower (T - 5°C) (Examples 1 to 3, 4 to 8) than the temperature T°C at which the maximum adhesive force is exhibited, and the maximum adhesive force value, it was confirmed that the pressure-sensitive adhesive sheet exhibits an adhesive behavior in which the increase gradient of the adhesive force is 0.1 N / °C·10 mm or more. As shown in FIGS. 1 and 2, it can be confirmed that the pressure-sensitive adhesive sheets of Example 1 (FIG. 1) and Example 3 (FIG. 2) exhibit a behavior in which the adhesive force rapidly increases with a small temperature change and the maximum adhesive force is exhibited, as compared with the adhesive behavior of the pressure-sensitive adhesive sheets of Comparative Examples 1 and 2 described later.

[0035] On the other hand, as shown in Table 3, the pressure-sensitive adhesive sheet of Example 9 using an SIS block copolymer, which is a conventional elastomer in the fields of pressure-sensitive adhesive sheets and adhesives, exhibits an adhesive behavior in which the adhesive force gradually decreases in the temperature range of 20°C to 45°C, and does not exhibit a behavior of showing a maximum adhesive force in the range of 30 to 45°C. Further, for the pressure-sensitive adhesive sheets of Examples 10 to 12, the increase gradient of the adhesive force between the maximum adhesive force in the temperature range of 30 to 45°C and the adhesive force value at a temperature 5°C lower (T - 5°C) than the temperature T°C at which the maximum adhesive force is exhibited was less than 0.1 N / °C·10 mm. Also, although the pressure-sensitive adhesive sheet of Example 13 showed a maximum adhesive force at 50°C, its value was only 0.06 N / 10 mm. Furthermore, the adhesive force of the pressure-sensitive adhesive sheet of Example 13 in the range of 20 to 50°C was at most only 0.06 N / 10 mm (50°C).

[0036] Note that Comparative Examples 1 and 2, which are commercially available temperature-sensitive pressure-sensitive adhesive sheets, showed a maximum value of the adhesive force at 35°C to 40°C, but the increase gradient of the adhesive force between the adhesive force value at a temperature 5°C lower (T - 5°C) than the temperature T°C at which the maximum adhesive force is exhibited was less than 0.1 N / °C·10 mm. It became.

[0037] According to the present invention, it is possible to provide a temperature-sensitive adhesive and an adhesive sheet that exhibit an adhesive behavior in which the adhesive force rapidly increases with a small temperature change in a temperature range of room temperature or higher, such as 30 to 45°C, and exhibit a maximum adhesive force.

Claims

1. A heat-sensitive adhesive composition containing a 4-methyl-1-pentene / α-olefin copolymer as an elastomer component, an adhesive sheet having an adhesive layer made of the temperature-sensitive adhesive composition provided on at least one surface of a substrate exhibits maximum adhesive strength to a BA-SUS plate in a temperature range of 30 to 45°C; The adhesive composition exhibits adhesive behavior in which the adhesive strength increasing gradient between the adhesive strength value at a temperature 3°C lower (T-3°C) or 5°C lower (T-5°C) than the temperature T°C at which the maximum adhesive strength is exhibited and the maximum adhesive strength value is 0.1 N / °C·10 mm or more.

2. The maximum adhesive strength to the BA-SUS plate is 1 N / 10 mm or more; The pressure-sensitive adhesive composition according to claim 1 .

3. The maximum adhesive strength to the BA-SUS plate is 2N / 10mm or more; The pressure-sensitive adhesive composition according to claim 1 .

4. The 4-methyl-1-pentene / α-olefin copolymer is a copolymer containing 70 mol % to 90 mol % of a unit structure derived from 4-methyl-1-pentene, 10 mol % to 30 mol % of a unit structure derived from an α-olefin having 2 or 3 carbon atoms, and 0 to 10 mol % of other unit structures (however, the total of all unit structures is 100 mol %); The pressure-sensitive adhesive composition according to claim 1 .

5. The pressure-sensitive adhesive composition further contains a tackifier resin and a softener. The pressure-sensitive adhesive composition according to claim 1 .

6. The tackifier resin is at least one selected from the group consisting of an aliphatic hydrocarbon resin, an aromatic modified terpene resin, and an alicyclic hydrogenated petroleum resin. The pressure-sensitive adhesive composition according to claim 5 .

7. The softener is at least one selected from the group consisting of oils, waxes, and polybutene. The pressure-sensitive adhesive composition according to claim 5 .

8. A pressure-sensitive adhesive sheet comprising a substrate and a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to claim 1 on at least one surface of the substrate.

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