TWI669373B - Double-sided adhesive tape, article and separation method - Google Patents

Abstract

The problem to be solved by the present invention is to provide a double-sided adhesive tape, which can be used for attaching to an adherend, fixing two or more adherends, and applying the two or more adherends. It can be easily disassembled when the body is separated. The present invention relates to a double-sided adhesive tape, which is characterized in that it has an adhesive layer directly or through other layers on both sides of an easily dismantleable layer containing an adhesive and thermally expandable microspheres. The present invention relates to an article having a structure in which two or more adherends are formed by adhering the double-sided adhesive tape.

Description

Double-sided adhesive tape, article and separation method

The present invention relates to an easily detachable double-sided adhesive tape. When using the double-sided adhesive tape to adhere to an adherend and to fix between articles, the attachment and fixing can be easily released after a certain period of time; and This invention relates to a method for separating two or more adherends bonded by the double-sided adhesive tape.

Adhesive tape is used as a bonding means with excellent processability and high reliability, and is used for fixing parts, temporarily fixing parts, and displaying product information in various industrial fields such as OA equipment, IT equipment, home appliances, and automobiles. . In recent years, from the viewpoint of protecting the global environment, the requirements for the recycling and reuse of old products in these industries have been increasing. When recovering and reusing various products, it is necessary to peel off the adhesive tape used for fixing parts and labels. However, since the adhesive tape is installed in various parts of the product, it is expected to reduce the work by simple removal steps. cost.

As an adhesive tape that is relatively easy to peel off, for example, an adhesive member having two or more adhesive layers having different adhesive forces has been disclosed (see Patent Document 1). The adhesive tape is used for joining and processing adherends through a weak adhesive layer in an adhesive member having an adhesive layer with an overlapped structure, so as to realize the firm fixing of the adherend and the ease of using the weak adhesive layer as a peeling surface. Disassembled adhesive members. However, since this adhesive member has a multi-layer adhesive layer as a necessary structure, there exists a problem of high manufacturing cost. In addition, the adhesive member has a structure for adhering to an adherend by a weak adhesive layer, and therefore there is a limit in improving the adhesive force, and it is difficult to expand the application for firmly fixing the article. [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 10-140093

[Problems to be Solved by the Invention]

The problem to be solved by the present invention is to provide a double-sided adhesive tape, which can be used for attaching to an adherend, fixing two or more adherends, and applying the two or more adherends. It can be easily disassembled when the body is separated. [Means for solving problems]

The present invention relates to a double-sided adhesive tape, which is characterized in that it has an adhesive layer directly or through other layers on both sides of an easily dismantleable layer containing an adhesive and thermally expandable microspheres.

The present invention relates to an article having a structure in which two or more adherends are formed by adhering the double-sided adhesive tape.

The present invention also relates to a separation method for separating the two or more adherends constituting the article by heating the easily dismantleable layer constituting the article to expand the thermally expandable microspheres. [Effect of the invention]

The double-sided adhesive tape of the present invention can be attached to an adherend, and can firmly adhere more than two adherends. When disassembling the adherends to thereby dismantle the above-mentioned articles, The two or more adherends can be easily separated by heating.

According to the manufacturing method of the double-sided adhesive tape of the present invention, the double-sided adhesive tape of the present invention can be manufactured.

According to the separation method of the present invention, the adherence of the adherends can be easily separated.

"Double-sided adhesive tape" The double-sided adhesive tape of the present invention is characterized in that it has an adhesive layer on both sides of an easily dismantleable layer containing an adhesive and thermally expandable microspheres or through other layers.

Hereinafter, an example of an embodiment of the double-sided adhesive tape of the present invention will be described.

<First Embodiment> FIG. 1 is an example of an embodiment of a double-sided adhesive tape according to the present invention. The double-sided adhesive tape 1 has adhesive layers 20 and 21 on both sides of the easily dismantleable layer 10 containing the adhesive 11 and the thermally expandable microspheres 12. On the adhesive layers 20 and 21, peeling sheets 30 and 31 may be laminated, respectively.

Hereinafter, each structure of a double-sided adhesive tape is demonstrated. [Easy disassembling layer] The easily disassembling layer 10 includes a binder 11 and a thermally expandable microsphere 12. The easy-to-disassemble layer is a layer that is broken by peeling stress such as separating the adherends from each other when separating the two or more adherends bonded by the double-sided adhesive tape.

As the binder, a substance that can be easily disassembled by the force of the expansion (generation) of the thermally expandable microspheres can be used. In addition, it is preferable to use thermoplastic as the adhesive. Here, the thermoplastic means the storage elastic modulus G ₂₃ of the adhesive measured by dynamic viscoelasticity spectrum at 1 Hz and 23 ° C. in a range of 1.0 × 10 ³ to 5.0 × 10 ⁷ Pa, and between 1 Hz and 120 ° C. The storage elastic modulus G ₁₂₀ determined by dynamic viscoelasticity spectrum is in a range of 1.0 × 10 ² to 5.0 × 10 ⁶ Pa.

In the normal state, the storage elastic modulus measured by dynamic viscoelasticity spectroscopy at 1 Hz and 23 ° C. using an adhesive constituting an easily dismantleable layer is used to firmly adhere the adherends to each other by the double-sided adhesive tape of the present invention G ₂₃ is preferably 1.0 × 10 ³ to 5.0 × 10 ⁷ Pa, more preferably 5.0 × 10 ³ to 5.0 × 10 ⁶ Pa, and more preferably 5.0 × 10 ³ to 1.0 × 10 ⁶ Pa. It is particularly preferable to be 1.0 × 10 ⁴ to 1.0 × 10 ⁶ Pa.

In addition, in terms of easily separating the adherends from each other by heating, the storage elastic modulus G ₁₂₀ measured by dynamic viscoelasticity spectrum at 1 Hz and 120 ° C. using a binder constituting an easily dismantleable layer is 1.0 × 10 ² It is preferably from 5.0 to 10 × 10 ⁶ Pa, more preferably from 5.0 × 10 ² to 1.0 × 10 ⁶ Pa, and even more preferably from 5.0 × 10 ² to 5.0 × 10 ⁵ Pa.

The storage elastic modulus G ₁₂₀ of the adhesive of the easily dismantleable layer should preferably be smaller than the storage elastic modulus G ₂₃ .

The above-mentioned storage elastic moduli G ₂₃ and G ₁₂₀ refer to the results of measurement on a test piece formed using an adhesive constituting an easily dismantleable layer. This test piece does not contain thermally expandable microspheres. The thickness of the test piece was 2 mm. The test piece can be obtained by applying an adhesive contained in the easily dismantleable layer to a sheet or the like.

The storage elastic moduli G ₂₃ and G ₁₂₀ can be measured using a commercially available viscoelasticity testing machine by a method described in Examples described later.

The thickness of the easily dismantleable layer is preferably 5 μm to 80 μm, more preferably 5 μm to 60 μm, and even more preferably 10 μm to 50 μm. The thickness of the easy-to-disassemble layer is an average value obtained by measuring the thickness of five places randomly selected in the thickness direction of the easy-to-disassemble layer. When the thickness of the easily dismantleable layer is within the above range, the layer can be easily disassembled and the layer can be easily disassembled and has excellent ease of disassembly.

When a thermoplastic resin is used for the said adhesive agent contained in the said easy-to-disassemble layer, for example, it is easy to soften by heat and it is easy to disassemble | disassemble.

Examples of the thermoplastic resin include urethane-based resins such as polyurethane (PU) and thermoplastic polyurethane (TPU); polycarbonate (PC); polyvinyl chloride (PVC); and vinyl chloride-vinyl acetate copolymerization Resins such as vinyl chloride resins; acrylic resins such as polyacrylic acid, polymethacrylic acid, polymethyl acrylate, polymethyl methacrylate (PMMA), and polyethyl methacrylate; polyethylene terephthalate Polyester resins such as polyester (PET), polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, polybutylene naphthalate; nylon (registered trademark) ) And other polyamido-based resins; polystyrene (PS), polyimide-modified polystyrene, acrylonitrile-butadiene-styrene (ABS) resin, polyimide-modified ABS resin, styrene-propylene Polystyrene resins such as nitrile copolymer (SAN) resins, acrylonitrile, ethylene-propylene-diene, and styrene (AES) resins; olefins such as polyethylene (PE) resins, polypropylene (PP) resins, and cycloolefin resins Resins; cellulose resins such as nitrocellulose and cellulose acetate; silicone resins; fluorine resins The thermoplastic resin of the thermoplastic elastomer, a styrene based thermoplastic elastomer, olefin thermoplastic elastomer, vinyl chloride thermoplastic elastomer, an amine-based urethane thermoplastic elastomers, ester-based thermoplastic elastomer, acyl amine-based thermoplastic elastomer.

As for the thermoplastic resin, styrene-based thermoplastic elastomer, olefin-based thermoplastic elastomer, vinyl chloride-based thermoplastic elastomer, ester-based thermoplastic elastomer, urethane-based thermoplastic elastomer, and ammonium A thermoplastic elastomer or an acrylic resin is preferred, and a styrene thermoplastic elastomer or an acrylic resin is particularly preferred.

Examples of the styrene-based thermoplastic elastomer include styrene-based diblock copolymers such as styrene-ethylene-butene copolymer (SEB); styrene-butadiene-styrene copolymer (SBS), and SBS Hydride (styrene-ethylene-butene-styrene copolymer (SEBS)), styrene-isoprene-styrene copolymer (SIS), SIS hydride (styrene-ethylene-propylene-benzene Styrene-based triblock copolymers such as ethylene copolymer (SEPS)), styrene-isobutylene-styrene copolymer (SIBS); styrene-butadiene-styrene-butadiene (SBSB) Tetrablock copolymer; styrene-butadiene-styrene-butadiene-styrene (SBSBS) and other styrene-based pentablock copolymers; styrene-based multiblock copolymers with such repeating units A hydride obtained by hydrogenating an ethylene-based double bond of a styrene-based random copolymer such as styrene-butadiene rubber (SBR). A commercially available styrene-based thermoplastic elastomer may be used.

For the styrene-based thermoplastic elastomer, when a mixture of the styrene-based triblock copolymer and the styrene-based diblock copolymer is used, the storage elastic modulus at 23 ° C and the The storage elastic modulus and the value of the storage elastic modulus at 23 ° C. divided by the storage elastic modulus measured at 120 ° C. As a result, two or more adherends were obtained at a normal temperature range of about 23 ° C. Adhesive tape can be firmly adhered, and two or more adherends can be easily separated by heating to about 120 ° C. The styrene-based two-embedded adhesive is used for the entire styrene-based thermoplastic elastomer. The content of the segment copolymer is more preferably in the range of 10% to 90% by mass, particularly preferably in the range of 15% to 80% by mass, and particularly preferably in the range of 20% to 75% by mass.

In terms of the above-mentioned styrene-based thermoplastic elastomer, it is preferable to use a weight average molecular weight having a range of 10,000 to 800,000 in order to further improve the dismantling property by heating, and use a material having a weight average of 50,000 to 500,000. A weight average molecular weight in the range is more preferable, and a weight average molecular weight in the range of 150,000 to 450,000 is used.

As said acrylic resin, the thing obtained by superposing | polymerizing the monomer containing an alkyl (meth) acrylate can be used, for example.

As the alkyl (meth) acrylate, a (meth) acrylate having an alkyl group having 4 to 12 carbon atoms is preferably used, and specifically, butyl (meth) acrylate, (meth) ) Isooctyl acrylate, 2-ethylhexyl (meth) acrylate and the like are preferred, and butyl acrylate and 2-ethylhexyl acrylate are used alone or in combination.

In addition to the aforementioned monomers, acrylonitrile, (meth) acrylic acid, maleic anhydride, acrylamide, itaconic acid, styrene, vinyl acetate, and the like can be used as the monomers.

The thermally expandable microspheres contained in the easily dismantleable layer are those capable of expanding due to the influence of heat. Specifically, the thermally expandable microspheres are preferably used with a thermal expansion coefficient of 150% or higher at 120 ° C, more preferably a thermal expansion coefficient of 170% or higher at 120 ° C, and a thermal expansion coefficient of 200% at 120 ° C. The above is particularly preferable. The thermal expansion coefficient of 120% or higher is particularly preferred. When the temperature is above 250%, the easily dismantleable layer can be easily disassembled. As a result, the adherends can be easily separated from each other. It is therefore particularly good. The upper limit of the expansion ratio is not particularly limited, but is preferably about 5000%. The thermal expansion coefficient is a value calculated by the following method.

First, 1 g of thermally expandable microspheres (unexpanded ones) was placed in a measuring flask, and the true specific gravity was measured by a water displacement method. Then, 1 g of this heat-expandable microsphere was put in a Geer type oven, and it expanded at 120 degreeC by heating for 2 minutes.

Then, the expanded microspheres were placed in a measuring flask, and the true specific gravity was measured by a water displacement method.

The ratio of the true specific gravity of the thermally expandable microspheres before expansion to the true specific gravity of the microspheres after thermal expansion was calculated, and the value obtained by multiplying this by 100 was taken as the thermal expansion coefficient.

The expansion start temperature of the thermally expandable microspheres is not particularly limited, but is preferably 80 ° C or higher, more preferably 85 ° C to 120 ° C, and when it is 90 ° C to 120 ° C, expansion does not occur when an easily dismantleable layer is formed, and It may cause thermal damage to two or more adherends, and is particularly advantageous in separating the two or more adherends. The "expansion starting temperature of the thermally expandable microspheres" is a thermal analyzer ("TMA / SS6100", manufactured by SII · Nanotechnology Inc.), and the expansion method (load: 0.1N, probe: 3mmΦ, heating rate: 5 ° C / min) The temperature at which the expansion of the thermally expandable microspheres is evaluated when the thermally expandable microspheres are evaluated.

The maximum expansion temperature of the thermally expandable microspheres is not particularly limited, but is preferably 90 ° C or higher, more preferably 90 ° C to 180 ° C, and when it is 100 ° C to 150 ° C, it does not cause heat of two or more adherends. Damage is particularly preferable in separating these two or more adherends. The "maximum expansion temperature" is a thermal analyzer ("TMA / SS6100", manufactured by SII · Nanotechnology Inc.), and the expansion method (load: 0.1N, probe: 3mmΦ, heating rate: 5 ° C / min) When the thermally expandable microspheres were evaluated, the temperature at which the expansion of the thermally expandable microspheres was the maximum. In addition, thermally expandable microspheres heated to a temperature higher than the maximum expansion temperature usually shrink and reduce the expansion rate. Therefore, it is better not to heat the microspheres to a temperature higher than the maximum expansion temperature.

In addition, when the thermally expandable microspheres are manufactured, it is difficult to uniformize the wall thickness of the capsules used in the production and the content of the vaporized substance, and thus the expansion start temperature and the maximum expansion temperature usually have a certain range.

The particle diameter (before expansion) of the thermally expandable microspheres is not particularly limited. The particle size (before expansion) of the heat-expandable microspheres is further increased to 1 μm in order to further improve the disassembly property of the easily dismantleable layer after heating and to realize the thinning of the easily dismantleable layer and the double-sided adhesive tape. The range is preferably from 50 to 50 μm, more preferably from 3 to 30 μm, and even more preferably from 5 to 20 μm.

The thermally expandable microspheres are generally a collection of microspheres having different particle sizes and the like. Therefore, when the particle diameter of the thermally expandable microspheres is measured, a distribution (particle size distribution) is obtained. In the present invention, the particle diameter (before expansion) of the thermally expandable microspheres is a particle size distribution based on 10 particle size distributions obtained by measuring 10 times using a laser diffraction scattering method using a particle size distribution measuring instrument "Mastersizer 2000" made by Malvern Instruments. The maximum and minimum values of the maximum value of 10 points are expressed in a range. Specifically, the maximum value of the particle diameter (before expansion) of the thermally expandable microspheres based on the 10 particle size distributions obtained by measuring 10 times using the above method is 15 μm, and when the minimum value is 9 μm, The particle diameter (before expansion) of this thermally expandable microsphere is 9 μm to 15 μm.

The heat-expandable microspheres can be used, for example, in cases where a capsule having elasticity contains a substance that is vaporized by heat.

It is preferable to use a substance that is vaporized by heating to a temperature of about 80 ° C to 150 ° C. Specifically, butane, isobutane, propane, isopentane, isooctane, etc. are used. good.

The above-mentioned elastic capsule can be made of, for example, a material which is softened by heating to about 90 ° C to 150 ° C. Specific examples include vinylidene chloride-acrylonitrile copolymer, polyvinyl alcohol, and polyethylene. Capsules made of butyral, polymethyl methacrylate, polyacrylonitrile, polyvinylidene chloride, polyfluorene, etc.

The thermally expandable microspheres can be produced by a known and commonly used method such as a Coacervation method and an interfacial polymerization method.

For the thermally expandable microspheres, for example, "Matsumoto microsphere" (trade name, manufactured by Matsumoto Oil & Fats Pharmaceutical Co., Ltd.), "Microsphere Expancel" (trade name, manufactured by Japan Fillite co., Ltd.), And "DAIFOAM" ( Trade names such as Daiichi Seika Chemical Industry Co., Ltd.).

The content (mixed amount) of the thermally expandable microspheres, in consideration of good adhesion to the adhesive layer and ease of disassembly, is preferably 100 parts by weight with respect to 100 parts by weight of the adhesive contained in the easily dissolvable layer. 1 to 100 parts by mass is preferred, 3 to 50 parts by mass is more preferred, and 5 to 30 parts by mass is particularly preferred.

[Adhesive agent layer] The adhesive agent layers 20 and 21 are layers adhered to the adherend. As the adhesive constituting the adhesive layers 20 and 21, natural rubber-based polymers, synthetic rubber-based polymers, acrylic polymers, silicone polymers, urethane-based polymers, and vinyl ether-based polymers can be used. And other substances. Examples of the form of the adhesive include solvent-based systems; water-based systems such as emulsion-type adhesives and water-soluble adhesives; solvent-free systems such as hot-melt adhesives, UV-curable adhesives, and EB-curable adhesives.

It is preferable that the said adhesive layer 20 and 21 contains an acrylic copolymer. The acrylic copolymer is a copolymer of (meth) acrylic acid having hydrophilicity and other monomers copolymerizable therewith, and examples thereof include (meth) acrylic acid esters obtained by reacting (meth) acrylic acid with vinyl ether.

The thickness of the adhesive layer is preferably 5 μm to 100 μm, more preferably 10 μm to 80 μm, and even more preferably 30 μm to 70 μm. When the thickness of the adhesive layer is in the above range, it is preferable to form the layer easily, and the adherence between the adherends is also excellent.

The adhesive agent layers 20 and 21 may contain a tackifier resin, a cross-linking agent, and other additives, if necessary.

The tackifying resin is for the purpose of adjusting the strong adhesion of the adhesive layer. For example, rosin-based tackifying resin, polymerized rosin-based tackifying resin, polymerized rosin-ester-based tackifying resin, rosin-phenol-based tackifying resin, and the like Rosin ester tackifying resin, disproportionated rosin ester tackifying resin, terpene based tackifying resin, terpene phenol based tackifying resin, petroleum resin based tackifying resin, etc.

The cross-linking agent may be a known isocyanate-based cross-linking agent, epoxy-based cross-linking agent, aziridine-based cross-linking agent, polyvalent metal salt-based cross-linking agent, or metal for the purpose of improving the cohesion of the adhesive layer. Chelate-based cross-linking agent, ketone and hydrazine-based cross-linking agent, oxazoline-based cross-linking agent, carbodiimide-based cross-linking agent, silane-based cross-linking agent, glycidyl (alkoxy) epoxysilane Department of cross-linking agents.

The above-mentioned additives can be optionally added to the adhesive to adjust the pH (such as ammonia) or acid, foaming agent, plasticizer, softener, and antioxidant to the extent that the desired effect of the present invention is not impaired. , Glass or plastic fibers, balloons, beads, metal powders and other fillers, pigments and dyes, colorants, pH adjusters, film-forming aids, leveling agents, thickeners, waterproofing agents, defoamers, etc. Well-known substance. Moreover, an acid catalyst and an acid generator may be added.

The acid catalyst and the acid generator can be used for the purpose of generating disassembly by external stimulus of light and heat, for example. As the acid catalyst and the acid generator, the same substances as those exemplified by the user in the easily dismantleable layer can be used.

The said adhesive agent which can be used for formation of the said adhesive agent layer can use the thing containing a solvent in order to maintain favorable coating processability. Examples of the solvent include toluene, xylene, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, and hexane. When an aqueous adhesive is used as the adhesive, water or an aqueous solvent mainly composed of water can be used as the solvent.

Examples of the release sheets 30 and 31 include cellophane, kraft paper, clay-coated paper, paper formed by laminating a film such as polyethylene, paper coated with a resin such as polyvinyl alcohol or an acrylate copolymer, and polymerized paper. Paper made by coating a release agent such as fluororesin or silicone resin on a synthetic resin film such as an ester or polypropylene.

The pair of adhesive layers of the double-sided adhesive tape of this embodiment may have the same structure, or may have different structures.

Since the double-sided adhesive of this embodiment contains thermally expandable microspheres in the easy-to-disassemble layer, the softening of the adhesive contained in the easy-to-dissolve layer and the expansion of the thermally-expandable microspheres occur by heating. As a result, Because, compared with the case of using an easily dismantleable layer that does not contain a thermally expandable filler, the adhesion of the adherends can be disassembled with a weaker force.

<Second Embodiment> Fig. 2 is an example of an embodiment of a double-sided adhesive tape according to the present invention. The double-sided adhesive tape 2 has adhesive layers 20 and 21 on both sides of the easy-to-disassemble layer 10 containing the adhesive 11 and the heat-expandable microspheres 12, and both of the easy-to-remove layer and the adhesive layer have Base film 40,41. On the adhesive layers 20 and 21, peeling sheets 30 and 31 may be laminated, respectively.

The double-sided adhesive tape of the second embodiment is one in which the double-sided adhesive tape of the above-mentioned <1st Embodiment> further has a base film 40, 41 between the easily dismantleable layer and the adhesive layer. It should be noted that descriptions of points common to the first embodiment will be omitted.

Examples of the base film include polyolefin (for example, polypropylene, polyethylene), polyester (for example, polyethylene terephthalate, polyethylene naphthalate), polystyrene, and acrylonitrile. -Butadiene-styrene resin (ABS resin), polycarbonate, polyimide, polyvinyl chloride, nylon, polyvinyl alcohol, etc .; plastic film; using pulp, rayon, manila hemp, acrylonitrile, Non-woven fabric, paper, cloth, or metal foil obtained from nylon, polyester, or the like.

The base film can serve as a support when the adherends affixed by the double-sided adhesive tape are detached from each other and the easy-to-disassemble layer is broken, and the double-sided adhesive tape is peeled from the adherend.

Therefore, it is easy to consider the adhesion between the base film and other layers of the double-sided adhesive tape (adhesion between the base films 40 and 41 and the adhesive layers 20 and 21 in this embodiment) and the strength as a support. Plastic film is better, polyester film is better.

In addition, for the purpose of improving the adhesion between the base film and the adhesive layer, corona treatment, plasma treatment, anchor coating treatment and the like can be performed on one or both sides of the base film.

In the double-sided adhesive tape of this embodiment, the adhesive contained in the easy-to-disassemble layer is softened by heating, and the thermally expandable microspheres are expanded. The cohesive force of the easy-to-disassemble layer is significantly reduced and can be easily disassembled. Therefore, after the above heating, the double-sided adhesive tape can be disassembled with almost no force, and two or more adherends can be separated from each other.

In addition, the double-sided adhesive tape of the second embodiment further has a base film between the easily detachable and the adhesive layer. After the removal of the double-sided adhesive tape, the residue of the double-sided adhesive tape may sometimes remain on the adherend. In particular, in a double-sided adhesive tape having a fragile layer such as an easy-to-disassemble layer, it may be difficult to remove the residue of the double-sided adhesive tape remaining on the adherend. However, the double-sided adhesive tape of this embodiment further has a base film between the easy-to-remove and the adhesive layer, so by holding the base film portion and pulling, etc., the disassembled double-sided adhesive tape can be easily The whole residue was peeled from the slime.

In addition, in this embodiment, a double-sided surface composed of an easily detachable layer 10 containing an adhesive 11 and thermally expandable microspheres 12, an adhesive layer 20, 21, a base film 40, 41, and a release sheet 30, 31 is exemplified. In addition to such a layer structure, an adhesive tape may further have an arbitrary layer structure.

For example, the double-sided adhesive tape of the present invention can be used with a foam (foam) between the above-mentioned base films 40, 41 and the adhesive layer 20, 21, or between the above-mentioned base films 40, 41 and the easily dismantleable layer 10. Material). This foam layer functions as a cushion and can provide cushioning properties to a double-sided adhesive tape having a foam layer.

The double-sided adhesive tape of the present invention can be suitably used, for example, for bonding rigid bodies and rigid bodies as adherends, and for separating rigid bodies and rigid bodies from each other. Examples of rigid bodies to be adhered include metal plates, metal frames, metal covers, glass plates, and plastic plates. The two or more adherends adhered by the double-sided adhesive tape of the present invention may be the same kind of adherends or different kinds of adherends. In addition, the adherends adhered and separated by the double-sided adhesive tape of the present invention may be the same kind of adherends, or may be different kinds of adherends.

The double-sided adhesive tape of the present invention can be easily disassembled by heating during separation between components during reuse and recycling. Therefore, it can be suitably used as a double-sided adhesive tape for fixing various parts of various products in industrial applications such as the automobile, building materials, OA, and home appliance industries. It also has good working efficiency when recycling, separating a large number of parts during recycling, and peeling a large number of labels.

The double-sided adhesive tape of the present invention can also be disassembled by a lower heating temperature. Therefore, it is particularly suitable for use as a double-sided adhesive tape that is fixed between parts of an electric product such as a mobile phone, an image display device, and a computer that are likely to be deteriorated by heat.

"Manufacturing method of double-sided adhesive tape" The manufacturing method of the double-sided adhesive tape of the present invention is to produce an easily dismantleable layer containing an adhesive and thermally expandable microspheres, and attach one of them to one side of the easily dismantleable layer. The adhesive layer is then bonded to another adhesive layer on the other side of the easily dismantleable layer.

FIG. 3 is an example of an embodiment of a method for manufacturing a double-sided adhesive tape according to the present invention. First, a mixture of an adhesive constituting an adhesive layer, an adhesive constituting an easily dismantleable layer, and a thermally expandable microsphere is prepared. Then, as shown in FIG. 3, using an applicator, an adhesive is applied to the release sheets 32, 34 to form an adhesive layer 20, 21, and a mixture of an adhesive and a heat-expandable microsphere is applied to the release sheet 33 to form a detachable sheet.解 层 10。 Layer 10. Then, the adhesive layer 20 is adhered on one side of the easy-to-disassemble layer 10, and then the adhesive layer 21 is adhered on the other side of the easy-to-disassemble layer 10 to obtain the double-sided adhesive tape of the present invention.

The production of the double-sided adhesive tape is preferably performed at a temperature of 80 ° C or lower in terms of suppressing the expansion of the thermally expandable microspheres, preferably at a temperature of 40 ° C to 80 ° C, and at a temperature of 50 ° C to 80 ° C. Better.

In the manufacturing method of the double-sided adhesive tape of this embodiment, the two adhesive layers 20 and 21 of the manufactured double-sided adhesive tape have the same structure. Therefore, the easily dismantleable layer and the adhesive layer are individually formed and bonded together. The forming step of the adhesive layer can be performed once, and the double-sided adhesive tape can be manufactured with good efficiency.

<< Adhering method and separating method >> The adhering method of the present invention is to adhere the adherends to each other by the double-sided adhesive tape of the present invention.

In the separation method of the present invention, the easily dismantleable layer is heated, and the adherends that have been attached by the adhesion method of the present invention are separated from each other.

FIG. 4 is an example of an embodiment of a bonding method according to the present invention. As shown in FIG. 4, the adherends 50 and 51 are brought into contact with the adhesive layers 20 and 21 on both sides of the double-sided adhesive tape, and the adherends are adhered to each other and then adhered.

FIG. 5 is an example of an embodiment of the separation method according to the present invention.

First, heat the double-sided adhesive tape. The heating of the double-sided adhesive tape can also be performed by heating the entire adherend and the double-sided adhesive tape. Then, the adhesive 11 of the easy-to-disassemble layer 10 is softened by heat, and the thermally expandable microspheres 12 are expanded. At this time, by applying a force to the double-sided adhesive tape in a direction separating the adherends 50 and 51 from each other, a peeling stress is applied to the double-sided adhesive tape. Since the easily dismantleable layer of the double-sided adhesive tape of the present invention contains thermally expandable microspheres, when the thermally expandable microspheres expand due to heating or the like, the adherends can be easily separated from each other.

FIG. 6 is a diagram schematically showing an example of the state of separation of adherends in the separation method and other methods of the present invention. FIG. 6 (a) is an example of the separation method of the present invention, and shows the case where the thermally expandable microspheres 12 are contained in the easy-to-disassemble layer 10 of the double-sided adhesive tape. FIG. 6 (b) shows a case where the easily removable layer 10 of the double-sided adhesive tape does not contain the thermally expandable microspheres 12.

As shown in FIG. 6 (b), when the thermally expansible microspheres 12 are not contained in the easily dismantleable layer 10, the stress applied to the adhesive 11 is dispersed, and the layer of the adhesive 11 is difficult to disassemble.

On the other hand, in the separation method of the present invention, since the easy-to-remove layer 10 of the double-sided adhesive tape contains thermally expandable microspheres 12, the thermally expandable microspheres 12 expand due to heating, as shown in FIG. 6 (a). It is shown that the stress concentration applied to the adhesive 11 can be disassembled with a smaller force compared with the case where the thermally expansible microsphere 12 is not contained in the easily disassembled layer, and the result is that the layer can be easily disassembled. Separate 2 or more adherends.

The heating performed in the above separation method can be appropriately selected according to the thermally expandable microspheres used and the operating environment, and is preferably 85 ° C to 150 ° C, and more preferably 90 ° C to 120 ° C. The double-sided adhesive tape of the present invention does not disassemble under normal use conditions (about 80 ° C or lower), and can be firmly adhered to each other. On the other hand, it is easy to detach when heated at the above temperature The delamination layer can be easily disassembled, and as a result, the adherend can be easily separated.

Examples of the heating method include a method of directly or indirectly heating the double-sided adhesive tape using a dryer or a halogen lamp.

During the heating, the halogen lamp can be brought close to or in contact with the double-sided adhesive tape, and the halogen lamp can also be indirectly heated by bringing the halogen lamp close to or contacting the adherend. For example, when the end of the double-sided adhesive tape is exposed to the outside than the end of the adherend, the halogen lamp can be made to approach or contact the end of the double-sided adhesive tape.

In the above heating step, using a heating device equipped with a halogen lamp or the like, the temperature of the double-sided adhesive tape is preferably heated to 80 ° C to 130 ° C, more preferably to 85 ° C to 125 ° C, and heated to 90 ° C to 120 ° C. It's better. The heating is preferably performed within 20 seconds, more preferably within 15 seconds, and even more preferably a shorter time within 10 seconds.

Specifically, if the heating step using the halogen lamp and dryer is a step of making the temperature of the double-sided adhesive tape to 100 ° C within 20 seconds, the disassembly efficiency of the article can be improved, and the heat of the adherend can be prevented. Deformation and the like are preferred.

In addition, a heating device equipped with a halogen lamp can be used, for example, a "parallel-type halogen lamp heater" capable of heating a certain area in a short time, a locally-collectable halogen-type halogen lamp, etc., and a parallel-type halogen lamp heater. It can heat a wide range at one time, so the heating time can be shortened to the above time.

The area that the parallel light type halogen lamp heater can heat at one time is preferably about 10 cm ² to 500 cm ² . In addition, if the heating device such as a parallel light type halogen lamp heater is portable in size and weight, it is preferable to improve the efficiency of disassembling the article. The weight is preferably 3 kg or less, more preferably 2 kg or less, and more preferably 0.1 kg to 1 kg.

The article heated by the method described above can be easily disassembled even if little or no force is applied to the two or more adherends constituting the article.

The double-sided adhesive tape of the present invention has very good adhesion in a temperature range of 60 ° C. or lower, and therefore, it can be used, for example, to form a transparent top plate and a housing of an electronic device such as a copier, a multifunction machine and the like having a copy function and a scan function. Fixed.

The transparent top plate may be a transparent top plate provided in a general copier or multifunction machine equipped with a copier function and a scanning function.

As the transparent top plate, for example, a transparent plate-shaped rigid body made of glass or plastic can be used. The plastic may be, for example, an acrylic plate or a polycarbonate plate.

The above-mentioned transparent top plate may be a shape matching a shape of a copier or the like provided with the transparent top plate, and generally a square or rectangular shape is preferred.

For the double-sided adhesive tape, for example, if the rectangular transparent top plate is rectangular, it is better to stick along the opposite ends. In this case, the adhesive tape may be cut to have a size corresponding to the length of the side of the transparent top plate, and for example, a width of 0.5 mm to 20 mm and a length of 0.1 mm to 2.0 mm are preferred.

In addition, the double-sided adhesive tape of the present invention can be used exclusively for fixing members constituting a portable electronic device. Examples of the member include two or more housings or lens members constituting the electronic device.

Examples of the portable electronic device include a structure in which the frame body as the member and one of the lens member or another frame body are joined via the double-sided adhesive tape.

The fixing of the member includes, for example, a method of laminating one of the frame body or lens member and the other frame body or lens member with the double-sided adhesive tape interposed therebetween, and then curing the member for a certain period of time.

FIG. 7 is an example of an embodiment of the separation method according to the present invention. First, the separation method shown in FIG. 6 is performed. At this time, residues of the disassembled double-sided adhesive tape remain on the adherends 50 and 51. Then, cool the double-sided adhesive tape. Then, the entire part of the double-sided adhesive tape can be peeled off from the adherend by pulling the part of the base film 41 in a state where the base film and the other layers of the double-sided adhesive tape are integrated.

The cooling may be performed at a temperature appropriately reduced to a state in which the softening degree of the adhesive in the residue of the double-sided adhesive tape softened by heating is reduced and the residue of the double-sided adhesive tape is easily removed. The temperature is preferably 35 ° C or lower, 25 ° C. The following is better. [Example]

[Production Example 1] The easily dismantleable layer (1) was a styrene-isoprene block copolymer S (a mixture of a triblock copolymer and a diblock copolymer with a weight average molecular weight of 200,000. The proportion of the segment copolymer to the total amount of the mixture is 52% by mass. The proportion of the mass of the polystyrene unit to the entire styrene-isoprene block copolymer is 15% by mass. 100 parts by mass of isoprene units) 100 parts by mass of C5 petroleum-based tackifying resin (softening point 100 ° C, number average molecular weight 885) 40 parts by mass; polymerized rosin ester-based tackifying resin (softening point 125 ° C) , Mass average molecular weight 880) 30 parts by mass, 5 parts by mass of HV-100 (low molecular weight polybutene, manufactured by JX Nippon Nissei Co., Ltd.) as a liquid tackifying resin, and Matsumoto microsphere as a thermally expandable microsphere F-48 (manufactured by Matsumoto Oil & Fats Pharmaceutical Co., Ltd., with a thermal expansion rate of 370% at 120 ° C, an expansion start temperature of 90 ° C to 100 ° C, a maximum expansion temperature of 125 ° C to 135 ° C, and a particle size (before expansion) of (9 μm to 15 μm) 10 parts by mass of the blending ratio are mixed and dissolved in toluene, thereby obtaining a mixture Rubber solution.

The solution was applied to the surface of a release sheet using an applicator so that the thickness after drying was 40 μm, and dried at 85 ° C. for 5 minutes to produce an easily disassembled layer (1).

[Manufacturing Example 2] Easy-to-disassemble layer (2) Replaced Matsumoto microsphere F-48 with Microsphere Expancel 053-40 (manufactured by Japan Fillite co., Ltd.), With a thermal expansion coefficient of 350% at 120 ° C and an expansion start temperature of 96 Except for ℃ ~ 103 ℃, the maximum expansion temperature is 138 ℃ ~ 146 ℃, and the particle size (before expansion) is 10 parts by mass, 10 parts by mass. Except for this, an easily dismantleable layer (2 ).

[Manufacturing Example 3] Easy-to-disassemble layer (3) Replaced Matsumoto microsphere F-48 with Microsphere Expancel 031-40 (manufactured by Japan Fillite co., Ltd.) With a thermal expansion coefficient of 450% at 120 ° C and an expansion start temperature of 81 Except for a mass of 10 ° C. to 95 ° C., a maximum expansion temperature of 120 ° C. to 135 ° C., and a particle size (before expansion) of 10 μm to 16 μm), an easily dismantleable layer (3 ).

[Manufacturing Example 4] Easy-to-disassemble layer (4) Replaced Matsumoto microsphere F-48 with Matsumoto microsphere FN-80GSD (Matsumoto Oil & Fat Pharmaceutical Co., Ltd.). The thermal expansion coefficient at 120 ° C was 220%, and the expansion start temperature was 100. Except for ℃ ～ 110 ℃, the maximum expansion temperature is 125 ℃ ～ 135 ℃, and the particle size (before expansion) is 6 parts by mass to 10 parts by mass). Except for this, 10 parts by mass are manufactured by the same method as in Production Example 1 above (4 ).

[Production Example 5] Easy-to-disassemble layer (5) The styrene-isoprene block copolymer S was replaced with a styrene-isoprene block copolymer T (triblock having a weight average molecular weight of 300,000) A mixture of a copolymer and a diblock copolymer. The proportion of the diblock copolymer to the total amount of the mixture is 20% by mass. The polystyrene unit is copolymerized with respect to the styrene-isoprene block copolymer. Except that the mass ratio of the entire product was 15% by mass and the mass ratio of the polyisoprene unit was 85% by mass), the easily dismantleable layer (5) was produced by the same method as in Production Example 1.

[Manufacturing example 6] Easy-to-disassemble layer (6) The usage and manufacturing example 1 was changed from 10 parts by mass to 20 parts by mass of Matsumoto microsphere F-48 (manufactured by Matsumoto Oils and Fats Pharmaceutical Co., Ltd.) The easy-to-disassemble layer (6) is produced in the same method.

[Manufacturing Example 7] Easy-to-disassemble layer (7) The usage and manufacturing example 1 was changed from 10 parts by mass to 5 parts by mass of Matsumoto microsphere F-48 (manufactured by Matsumoto Oil and Fat Pharmaceutical Co., Ltd.) The easy-to-disassemble layer (7) is produced in the same method.

[Manufacturing Example 8] The easy-disassembly layer (8) was manufactured by the same method as in Manufacturing Example 1 except that the thickness of the easy-disassembly layer was changed from 40 μm to 20 μm.

[Manufacturing Example 9] The easily dismantleable layer (9) was obtained by using 100 parts by mass of LA2250 (manufactured by Kurary Co., LTD., An acrylic thermoplastic elastomer) and Matsumoto microsphere F-48 (manufactured by Matsumoto Oil & Fat Pharmaceutical Co., Ltd. The thermal expansion coefficient at 120 ° C is 370%, the expansion start temperature is 90 ° C to 100 ° C, the maximum expansion temperature is 125 ° C to 135 ° C, and the particle size (before expansion) is 9 μm to 15 μm) 10 parts by mass are mixed with toluene to obtain The non-volatile component is an acrylic resin composition of 40% by mass.

The acrylic resin composition was applied to the surface of a release sheet using an applicator so that the thickness after drying was 40 μm, and dried at 85 ° C. for 5 minutes to produce an easily dismantleable layer (9).

[Manufacturing example 10] The easily dismantleable layer (10) In a reaction vessel equipped with a stirrer, a reflux condenser, a thermometer, a dropping funnel, and a nitrogen inlet, 44.9 parts by mass of butyl acrylate and 2-ethylhexyl acrylate 50 parts by mass, 2 parts by mass of acrylic acid, 3 parts by mass of vinyl acetate, 0.1 parts by mass of 4-hydroxybutyl acrylate, and 0.1 parts by mass of 2,2'-azobisisobutyronitrile as a polymerization initiator, dissolved in acetic acid In 100 parts by mass of ethyl ester, polymerization was performed at 70 ° C. for 10 hours to obtain an acrylic copolymer solution having a weight average molecular weight of 800,000. Then, based on 100 parts by mass of the acrylic copolymer, 30 parts by mass of a polymerized rosin ester tackifying resin (softening point: 125 ° C., number average molecular weight: 880) was added, and ethyl acetate was added and mixed to obtain a non-volatile The acrylic component (1) has a sexual component of 45% by mass.

100 parts by mass of the aforementioned acrylic copolymer composition (1), 1.1 parts by mass of "CORONATE L-45" (manufactured by Japan Polyurethane Industries, Ltd., an isocyanate-based cross-linking agent, with a solid content of 45% by mass), and Matsumoto microsphere F-48 (manufactured by Matsumoto Oil & Fats Pharmaceutical Co., Ltd., with a thermal expansion coefficient of 370% at 120 ° C, an expansion start temperature of 90 ° C to 100 ° C, a maximum expansion temperature of 125 ° C to 135 ° C, particle size (before expansion) (9 μm to 15 μm) 10 parts by mass were mixed, and then the surface of the release sheet was coated with an applicator so that the thickness after drying was 40 μm, and dried at 85 ° C. for 5 minutes to form an easily disassembled layer (10).

[Manufacturing Example 11] The easily dismantleable layer (11) 44.9 parts by mass of butyl acrylate, 50 parts by mass of 2-ethylhexyl acrylate, 2 parts by mass of acrylic acid, 3 parts by mass of vinyl acetate, and 4-hydroxybutyl acrylate 0.1 Except for replacing 20 parts by mass of butyl acrylate and 74.9 parts by mass of 2-ethylhexyl acrylate, the easily disassembled layer (11) was formed by the same method as in Production Example 10.

[Comparative Manufacturing Example 1] The core layer (1) was manufactured by the same method as in Manufacturing Example 1 except that Matsumoto microsphere F-48 (manufactured by Matsumoto Oil & Fat Pharmaceutical Co., Ltd.) was not used.

[Comparative Manufacturing Example 2] The core layer (2) was manufactured in the same manner as in Manufacturing Example 9 except that Matsumoto microsphere F-48 (manufactured by Matsumoto Oil & Fat Pharmaceutical Co., Ltd.) was not used.

[Comparative Manufacturing Example 3] The core layer (3) was manufactured in the same manner as in Manufacturing Example 10 except that Matsumoto microsphere F-48 (manufactured by Matsumoto Oil & Fat Pharmaceutical Co., Ltd.) was not used.

[Comparative Manufacturing Example 4] The core layer (4) was manufactured by the same method as in Manufacturing Example 11 except that Matsumoto microsphere F-48 (manufactured by Matsumoto Oil & Fat Pharmaceutical Co., Ltd.) was not used.

[Preparation Example 1] Adhesive layer (1) In a reaction vessel equipped with a stirrer, a reflux condenser, a thermometer, a dropping funnel, and a nitrogen inlet, 44.9 parts by mass of butyl acrylate and 2-ethylhexyl acrylate 50 Parts by mass, 2 parts by mass of acrylic acid, 3 parts by mass of vinyl acetate, 0.1 parts by mass of 4-hydroxybutyl acrylate, and 0.1 parts by mass of 2,2'-azobisisobutyronitrile as a polymerization initiator, dissolved in ethyl acetate In 100 parts by mass of the ester, an acrylic copolymer solution having a weight average molecular weight of 800,000 was obtained by polymerizing at 70 ° C. for 10 hours. Then, based on 100 parts by mass of the acrylic copolymer, 30 parts by mass of a polymerized rosin ester tackifying resin (softening point: 125 ° C., number average molecular weight: 880) was added, and ethyl acetate was added and mixed to obtain a non-volatile The acrylic component (1) has a sexual component of 45% by mass.

100 parts by mass of the above-mentioned acrylic copolymer composition (1) was mixed with 1.1 parts by mass of "CORONATE L-45" (manufactured by Japan Polyurethane Industries, Ltd., an isocyanate-based crosslinking agent, and a solid content of 45% by mass). The obtained adhesive was applied to the surface of the release sheet using an applicator so that the thickness after drying became 50 μm, and dried at 85 ° C. for 5 minutes to form an adhesive layer (1).

(Example 1) As shown in FIG. 8 (a), the above-mentioned adhesive layer (1) 22 was bonded to a polyethylene terephthalate film 42 (bonded product) having a thickness of 16 μm.

On the other hand, the other adhesive layer (1) 23 and the easy-to-disassemble layer (1) 15 were each adhered to both sides of a polyethylene terephthalate film 43 having a thickness of 16 μm. Then, the release sheet on the surface of the easy-to-disassemble layer (1) 15 is removed, and it is bonded to the previously-produced polyethylene terephthalate film 42 and the bonded product of the adhesive layer (1) 22 The double-sided adhesive tape of Example 1 was produced by laminating under pressure at a pressure of 4 kgf / cm ² .

(Example 2) A double-sided adhesive tape of Example 2 was produced by the same method as that of Example 1 except that the easy-disassembly layer (1) was replaced by the easy-disassembly layer (2).

(Example 3) A double-sided adhesive tape of Example 3 was produced by the same method as that of Example 1 except that the easy-disassembly layer (1) was replaced by the easy-disassembly layer (3).

(Example 4) A double-sided adhesive tape of Example 4 was produced by the same method as that of Example 1 except that the easy-disassembly layer (1) was replaced by the easy-disassembly layer (4).

(Example 5) A double-sided adhesive tape of Example 5 was produced by the same method as that of Example 1 except that the easy-disassembly layer (1) was replaced by the easy-disassembly layer (5).

(Example 6) A 16-m-thick polyethylene terephthalate film was replaced with a 16-m-thick polyethylene terephthalate film and a 100-m-thick polyolefin-based foam. A double-sided adhesive tape of Example 6 was produced by the same method as that of Example 1 except that the layered body was brought into contact with the easily dismantleable layer of the foam side.

(Example 7) A double-sided adhesive tape of Example 7 was produced by the same method as that of Example 1 except that the easy-disassembly layer (1) was replaced by the easy-disassembly layer (6).

(Example 8) A double-sided adhesive tape of Example 8 was produced by the same method as that of Example 1 except that the easy-disassembly layer (1) was replaced by the easy-disassembly layer (7).

(Example 9) A double-sided adhesive tape of Example 9 was produced by the same method as that of Example 1 except that the easy-disassembly layer (1) was replaced by the easy-disassembly layer (8).

(Example 10) A double-sided adhesive tape of Example 10 was produced by the same method as that of Example 1 except that the easy-disassembly layer (1) was replaced by the easy-disassembly layer (9).

(Example 11) A double-sided adhesive tape of Example 11 was produced by the same method as that of Example 1 except that the easy-disassembly layer (1) was replaced by the easy-disassembly layer (10).

(Example 12) A double-sided adhesive tape of Example 12 was produced by the same method as that of Example 1 except that the easy-disassembly layer (1) was replaced by the easy-disassembly layer (11).

(Comparative Example 1) A double-sided adhesive tape of Comparative Example 1 was produced in the same manner as in Example 1 except that the easily dismantleable layer (1) was replaced with the core layer (1).

(Comparative Example 2) A double-sided adhesive tape of Comparative Example 2 was produced by the same method as that of Example 1 except that the easily dismantleable layer (1) was replaced by the core layer (2).

(Comparative Example 3) A double-sided adhesive tape of Comparative Example 3 was produced in the same manner as in Example 1 except that the easily dismantleable layer (1) was replaced with the core layer (3).

(Comparative Example 4) A double-sided adhesive tape of Comparative Example 4 was produced by the same method as that of Example 1 except that the easily dismantleable layer (1) was replaced with the core layer (4).

The double-sided adhesive tape obtained in the said Example and the comparative example was evaluated as follows. The obtained results are shown in Tables 1 and 2.

<180-degree peeling adhesive force at normal temperature> The 180-degree peeling adhesive force was measured according to JIS Z 0237.

The release sheet on one side of the double-sided adhesive tape was peeled off, and this adhesive layer was backed with an aluminum foil having a thickness of 50 μm. This backed adhesive tape was cut to a width of 20 mm, and then the release sheet on the other side was peeled off, and this adhesive layer was bonded to the smooth surface of the SUS board after the degreasing treatment as a test piece.

After the test piece was left at 23 ° C for 30 minutes, a TENSILON tensile tester [manufactured by A & D Co., Ltd., model: RTM-100] was used to measure the double-sided adhesion of the test piece in the same environment. Adhesive force when the tape was peeled from the SUS board in a 180 degree direction at a speed of 300 mm / min.

<180-degree peeling adhesive force after heating> The 180-degree peeling adhesive force was measured according to JIS Z 0237.

The release sheet on one side of the double-sided adhesive tape was peeled off, and this adhesive layer was backed with an aluminum foil having a thickness of 50 μm. This backed adhesive tape was cut to a width of 20 mm, and then the release sheet on the other side was peeled off, and this adhesive layer was bonded to the smooth surface of the SUS board after the degreasing treatment as a test piece.

After the above test piece was left at 120 ° C for 30 minutes, a TENSILON tensile tester [manufactured by A & D Co., Ltd., model: RTM-100] was used to measure the double-sided adhesion of the test piece in the same environment. Adhesive force when the tape was peeled from the SUS board in a 180 degree direction at a speed of 300 mm / min.

<Disassembly test after heating> FIG. 9: is a figure explaining the method of a disassembly test. First, the double-sided adhesive tapes obtained in Examples and Comparative Examples were cut into a square shape with a length of 20 mm on one side (outer side). This cut double-sided adhesive tape 202 was bonded to a smooth surface of a degreased SUS board 201 having a length of 100 mm, a width of 30 mm, and a thickness of 1 mm.

Then, the degreased smooth surface of the SUS board 201 'was affixed to the side opposite to the side to which the double-sided adhesive tape 202 and the SUS board 201 were attached, and pressed back and forth once with a 5 kg load roller as the Test strip.

The prepared test piece was left to stand at 120 ° C for 30 minutes, and then taken out at 23 ° C. The SUS plate was easily separated when holding both ends of SUS plates 201 and 201 'within 15 seconds and peeling them vertically. Evaluate.

○: Because the double-sided adhesive tape was broken in the easily dismantled layer, the two SUS boards were separated without applying any force. As a result, the test piece can be disassembled without applying any force.

(Triangle | delta): Two SUS boards are followed, but they can be separated by applying a small force, and the said test piece can be disassembled.

╳: It is impossible to separate the two SUS boards and disassemble the above test pieces without applying considerable force with both hands.

<Dynamic viscoelasticity (storage elastic modulus) measurement of the adhesive constituting the easily dismantleable layer and the core layer> The adhesive used in the manufacture of the easily dismantleable layer and the core layer is dissolved in toluene and dried. After the thickness was 100 μm, the surface of the release liner was coated with an applicator, and dried at 85 ° C. for 5 minutes to form a plurality of 100 μm thick adhesive layers.

Then, a test piece composed of an adhesive layer having a thickness of 2 mm was produced by overlapping the adhesive layers obtained using the same adhesive.

A parallel plate having a diameter of 7.9 mm was mounted on a viscoelasticity tester (ARES 2kSTD) manufactured by TA Instruments. Japan. The test piece was sandwiched into the parallel plate with a compressive load of 50 g, and the storage elastic modulus (G ₂₃ ) and The storage elastic modulus (G ₁₂₀ ) was measured at 120 ° C.

[Table 1]

[Table 2]

[table 3]

1, 2‧‧‧ double-sided adhesive tape

10‧‧‧Easy disassembly layer

11‧‧‧Binder

12‧‧‧ heat-expandable microspheres (before expansion)

12’‧‧‧ heat-expandable microspheres (after expansion)

20, 21‧‧‧ Adhesive layer (1)

30, 31, 32, 33, 34

40, 41‧‧‧ basement membrane

50, 51‧‧‧ adherent

3, 4‧‧‧ double-sided adhesive tape

14‧‧‧ heat-expandable microspheres (before expansion)

15‧‧‧Easy disassembly layer (1)

16‧‧‧ core layer (1)

22, 23‧‧‧ Adhesive layer (1)

42, 43‧‧‧ polyethylene terephthalate film

202‧‧‧Double-sided adhesive tape

201, 201’‧‧‧SUS board

1 is a cross-sectional view showing an example of an embodiment of a double-sided adhesive tape according to the present invention. Fig. 2 is a cross-sectional view showing an example of an embodiment of a double-sided adhesive tape according to the present invention. [FIG. 3] It is a figure explaining an example of embodiment of the manufacturing method of the double-sided adhesive tape according to this invention. 4 is a diagram illustrating an example of an embodiment of a bonding method according to the present invention. [FIG. 5] A diagram illustrating an example of an embodiment of the separation method according to the present invention. [Fig. 6] (a) to (b) are diagrams schematically showing a state of separation of adherends. 7 is a cross-sectional view showing an example of an embodiment of a separation method according to the present invention. [Fig. 8] (a) to (b) explain the manufacturing method of the double-sided adhesive tape of Example 1 and the double-sided adhesive tape of Comparative Example 1, and the double-sided adhesive tape of Example 1 and the double-sided adhesive tape of Comparative Example 1. Diagram of the structure of an adhesive tape. [Fig. 9] Fig. 9 is a diagram illustrating a method of a disassembly test in Examples.

Claims (11)

A double-sided adhesive tape, characterized in that an adhesive layer is provided on both sides of an easy-to-disassemble layer containing an adhesive and thermally expandable microspheres, and the adhesive is stored at 1 Hz and 23 ° C by dynamic viscoelasticity spectrum measurement. The elastic modulus G ₂₃ is in a range of 5.0 × 10 ³ to 5.0 × 10 ⁶ Pa. The storage elastic modulus G ₁₂₀ measured at 1 Hz and 120 ° C. by dynamic viscoelasticity spectrum is 5.0 × 10 ² to 1.0 × 10 ⁶ Pa. Range, the storage elastic modulus G _{120 is} smaller than the storage elastic modulus G ₂₃ . For example, the double-sided adhesive tape of item 1 of the patent application scope, wherein the adhesive is a thermoplastic resin. For example, the double-sided adhesive tape of item 1 or 2 of the patent application scope, wherein the adhesive is a styrene-based thermoplastic elastomer, an olefin-based thermoplastic elastomer, or an acrylic resin. For example, the double-sided adhesive tape according to item 3 of the patent application, wherein the styrene-based thermoplastic elastomer contains a styrene-based diblock copolymer and a styrene-based triblock copolymer, and the styrene-based diblock copolymer is copolymerized. The content of the substance is in a range of 10% by mass to 90% by mass based on the entire styrene-based thermoplastic elastomer. For example, the double-sided adhesive tape of item 1 or 2 of the patent application scope, wherein the thermal expansion coefficient of the thermally expandable microspheres at 120 ° C is more than 150%. For example, the double-sided adhesive tape of item 1 or 2 of the patent application scope, wherein the heat-expandable microspheres are contained in a flexible capsule containing a substance vaporized by heat. For example, the double-sided adhesive tape of item 1 or 2 of the patent application scope, wherein at least one of the easy-to-disassemble layer and the adhesive layer has a base film. For example, the double-sided adhesive tape according to item 7 of the patent application, wherein a base film is provided between the easily dismantleable layer and the adhesive layer. For example, the double-sided adhesive tape of item 1 or 2 of the patent application scope, wherein at least one of the adhesive layers contains an acrylic copolymer. An article characterized by having a structure in which two or more adherends are adhered by a double-sided adhesive tape according to any one of items 1 to 9 of the scope of patent application. A method for separating, by heating the easily dismantleable layer constituting the article as claimed in item 10 of the patent application, to expand the heat-expandable microspheres, thereby separating two or more adherends constituting the article.