Double-sided adhesive tape, article and disassembly method

Abstract

The present invention provides a double-sided pressure-sensitive adhesive tape that combines high adhesive strength with excellent ease of dismantling. The double-sided pressure-sensitive adhesive tape comprises a first pressure-sensitive adhesive layer, a separation layer that is provided on the first pressure-sensitive adhesive layer and contains a pigment, a film-like substrate that is directly laminated on the separation layer, and a second pressure-sensitive adhesive layer that is provided on the film-like substrate, the pigment containing at least one selected from the group consisting of carbon black, titanium oxide, and phthalocyanine blue.

Description

[Technical field]

[0001] The present invention relates to a double-sided pressure-sensitive adhesive tape, an article, and a disassembly method. [Background technology]

[0002] Double-sided adhesive materials have been used to fix various members together, and improvements in their adhesive strength and holding power have been studied. For example, Patent Document 1 discloses a foam tape including a corona-treated foam and an adhesive layer formed on one or both sides of the foam. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-95722 A Summary of the Invention [Problem to be solved by the invention]

[0004] As one form of versatile double-sided adhesive tape, there is a demand for a double-sided adhesive tape that can firmly bond two or more adherends and can be easily disassembled as desired. However, if a strong adhesive force to the adherend is ensured, disassembly after application tends to be difficult. In addition, if the peelability of the double-sided adhesive tape is improved to ensure disassembly, the adhesive force is likely to be insufficient.

[0005] Therefore, the present invention aims to provide a double-sided pressure-sensitive adhesive tape that combines high adhesive strength with excellent ease of dismantling. Another object of the present invention is to provide an article that combines strong adhesion between components with ease of dismantling. A further object of the present invention is to provide a dismantling method that allows components joined with the double-sided pressure-sensitive adhesive tape to be easily separated from each other. [Means for solving the problem]

[0006] One aspect of the present invention relates to a double-sided pressure-sensitive adhesive tape comprising a first pressure-sensitive adhesive layer, a separation layer provided on the first pressure-sensitive adhesive layer and containing a pigment, a film-like substrate laminated directly on the separation layer, and a second pressure-sensitive adhesive layer provided on the film-like substrate, wherein the pigment comprises at least one selected from the group consisting of carbon black, titanium oxide, and phthalocyanine blue.

[0007] According to the double-sided pressure-sensitive adhesive tape, two or more adherends can be firmly bonded by the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer. In addition, the double-sided pressure-sensitive adhesive tape can be easily separated and dismantled by inserting a flat tool from the side of the tape to peel off the interface between the separation layer and the film-like substrate.

[0008] In one embodiment, the first pressure-sensitive adhesive layer may be a foam.

[0009] In one embodiment, the separation layer may have a tensile stress of less than 4 MPa at break. A double-sided pressure-sensitive adhesive tape having such a separation layer has excellent impact resistance after bonding and can bond an adherend more firmly.

[0010] In one embodiment, the separation layer may be a coating of a coating liquid containing the pigment and the binder resin, and may be a layer containing the pigment and the binder resin. Such a separation layer tends to have a low tensile stress at break (for example, less than 4 MPa).

[0011] In one embodiment, the separation layer may have a tensile stress of 4 MPa or more at break, and a tensile elongation of 360% or less at break. In a double-sided pressure-sensitive adhesive tape having such a separation layer, re-adhesion is unlikely to occur after peeling when the interface between the separation layer and the film-like substrate is peeled off, and therefore the entire interface can be peeled off more smoothly.

[0012] In one embodiment, the separation layer may be a coating of a coating liquid containing the pigment, binder resin, and curing agent, and may be a layer containing a cured product of the pigment and the binder resin. Such a separation layer tends to have a high tensile stress at break (e.g., 4 MPa or more) and a low tensile elongation at break (e.g., 360% or less).

[0013] The double-sided pressure-sensitive adhesive tape according to one embodiment may further comprise an auxiliary layer laminated directly on the first pressure-sensitive adhesive layer, and the separation layer may be laminated directly on the auxiliary layer.

[0014] Another aspect of the present invention relates to an article comprising a first member, a second member, and a joint that joins the first member and the second member, the joint having a first region made of the double-sided adhesive tape having a tensile stress intensity at break of less than 4 MPa at the separation layer, and a second region made of the double-sided adhesive tape having a tensile stress intensity at break of 4 MPa or more and a tensile elongation rate at break of the separation layer of 360% or less.

[0015] In the above article, the first member and the second member are joined in the first region with a double-sided adhesive tape that has excellent impact resistance after bonding and can more firmly bond the adherend, so that peeling of the first member and the second member due to impact is sufficiently suppressed. Also, in the above article, the first member and the second member are joined in the second region with a double-sided adhesive tape that has excellent dismantling properties, so that the first member and the second member can be easily separated by dismantling starting from the second region.

[0016] Yet another aspect of the present invention relates to a method for dismantling two or more components joined with the double-sided adhesive tape, the dismantling method including a step of inserting a flat tool from a side of the double-sided adhesive tape and peeling off the interface between the separation layer and the film-like substrate.

[0017] According to the above dismantling method, the components can be easily separated and dismantled. Effect of the Invention

[0018] According to the present invention, there is provided a double-sided pressure-sensitive adhesive tape that combines high adhesive strength with excellent ease of dismantling. According to the present invention, there is also provided an article that combines strong adhesion between members with ease of dismantling. Furthermore, according to the present invention, there is provided a dismantling method that allows members joined with the double-sided pressure-sensitive adhesive tape to be easily separated from each other. [Brief description of the drawings]

[0019] [Figure 1] 1 is a cross-sectional view showing an outline of one embodiment of a double-sided pressure-sensitive adhesive tape. [Diagram 2] FIG. 11 is a cross-sectional view showing an outline of another embodiment of a double-sided pressure-sensitive adhesive tape. [Diagram 3] FIG. 1A is a cross-sectional view showing an outline of one embodiment of an article, and FIG. 1B is a cross-sectional view showing a cross section taken along line AA in FIG. [Figure 4] 1A to 1C are diagrams illustrating one embodiment of a method for dismantling a double-sided adhesive tape. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. Note that the drawings are partially exaggerated for ease of understanding, and the dimensional ratios and the like are not limited to those shown in the drawings.

[0021] (double-sided adhesive tape) The double-sided adhesive tape of this embodiment comprises a first adhesive layer, a separation layer provided on the first adhesive layer and containing at least one pigment selected from the group consisting of carbon black, titanium oxide, and phthalocyanine blue, a film-like substrate laminated directly on the separation layer, and a second adhesive layer provided on the film-like substrate.

[0022] According to the double-sided pressure-sensitive adhesive tape of the present embodiment, two or more adherends can be firmly bonded by the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer. For example, by bonding members to each of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer, an article including two or more members can be easily manufactured.

[0023] In addition, the double-sided adhesive tape of this embodiment can easily separate and dismantle the adherends by inserting a flat tool from the side of the tape and peeling off the interface between the separation layer and the film-like substrate. That is, an article including members joined with the double-sided adhesive tape of this embodiment can easily separate and dismantle the members by inserting a flat tool from the side of the double-sided adhesive tape and peeling off the interface between the separation layer and the film-like substrate.

[0024] The first pressure-sensitive adhesive layer is a layer mainly composed of a pressure-sensitive adhesive, and may be a layer containing a pressure-sensitive adhesive. Examples of pressure-sensitive adhesives constituting the first pressure-sensitive adhesive layer include acrylic pressure-sensitive adhesives, rubber pressure-sensitive adhesives, urethane pressure-sensitive adhesives, silicone pressure-sensitive adhesives, block copolymer pressure-sensitive adhesives, and the like. The pressure-sensitive adhesive constituting the first pressure-sensitive adhesive layer may be an acrylic pressure-sensitive adhesive. The first pressure-sensitive adhesive layer may be a layer containing one type of pressure-sensitive adhesive or a layer containing two or more types of pressure-sensitive adhesives. The first pressure-sensitive adhesive layer may be a single layer or two or more layers.

[0025] The first pressure-sensitive adhesive layer may be a foam from the viewpoint of maintaining sufficient adhesive strength and making it easier to dismantle the article after adhesion. The first pressure-sensitive adhesive layer being a foam means that at least a part of the first pressure-sensitive adhesive layer is a foam. The first pressure-sensitive adhesive layer may be a foam containing an acrylic pressure-sensitive adhesive, and for example, the technology described in Japanese Patent No. 5746828 can be applied.

[0026] The first pressure-sensitive adhesive layer may be, for example, a commercially available foam tape, such as Y-4825, Y-4950, Y-4180, Y-4930, Y-4920, Y-4914, Y-4300, or 86425 (all manufactured by 3M).

[0027] The thickness of the first adhesive layer (when the first adhesive layer is composed of two or more layers, the thickness of the entire first adhesive layer) may be, for example, 0.15 mm or more, 0.2 mm or more, or 0.4 mm or more. When the thickness of the first adhesive layer is 0.15 mm or more, it becomes easier to insert a flat tool from the side of the double-sided adhesive tape, and it becomes easier to dismantle the members joined with the double-sided adhesive tape. The thickness of the first adhesive layer may be, for example, 10 mm or less, 5 mm or less, or 2 mm or less. When the thickness of the first adhesive layer is 10 mm or less, the bonding strength by the first adhesive layer tends to be further improved.

[0028] The separation layer is a layer provided on the surface of the film-like substrate and bonded to the film-like substrate, and is a layer that is peeled off from the surface of the film-like substrate when the article bonded with the double-sided adhesive tape is disassembled.

[0029] The separation layer is a layer containing a pigment, and the pigment contains at least one selected from the group consisting of carbon black, titanium oxide, and phthalocyanine blue.

[0030] The double-sided adhesive tape of this embodiment has a separation layer containing a specific pigment, which allows it to achieve excellent ease of dismantling without impairing the adhesive strength of the first adhesive layer and the second adhesive layer. This is thought to be because the pigment serves as the starting point for peeling when a flat instrument is inserted, allowing the separation layer and the film-like substrate to be easily peeled off. In addition, because the separation layer contains a pigment, the coloring of the separation layer serves as a guide for the insertion location when a flat instrument is inserted into the side of the tape, There is also the aspect of improving workability.

[0031] Carbon black can be used as a black pigment without any particular limitation. The average particle size of carbon black can be, for example, 0.008 μm or more, or 0.01 μm or more. The average particle size of carbon black can be, for example, 0.1 μm or less, or 0.04 μm or less. The method for measuring the average particle size of carbon black is not particularly limited, but for example, the arithmetic mean diameter obtained by observation with an electron microscope may be within the above range.

[0032] The carbon black may be, for example, a commercially available carbon black, such as Mitsubishi Carbon Black RCF♯85 (manufactured by Mitsubishi Chemical Corporation).

[0033] Titanium oxide may be used as a white pigment without any particular limitation. The average particle size of titanium oxide may be, for example, 0.1 μm or more, or 0.15 μm or more. The average particle size of titanium oxide may be, for example, 0.8 μm or less, or 0.35 μm or less. The method for measuring the average particle size of titanium oxide is not particularly limited, but for example, the arithmetic mean diameter obtained by observation with an electron microscope may be within the above range.

[0034] As the titanium oxide, for example, commercially available titanium oxide can be used, for example, JR-805 (manufactured by Teika Corporation) and the like.

[0035] Examples of phthalocyanine blue include α-, β-, and ε-type copper phthalocyanine, and may be, for example, Pigment Blue 15.

[0036] As the phthalocyanine blue, for example, commercially available phthalocyanine blue can be used. Examples of commercially available phthalocyanine blue include Cyanine Blue 4920 (manufactured by Dainichi Seika Chemicals Mfg. Co., Ltd.).

[0037] The separation layer may contain a small amount of pigments other than carbon black, titanium oxide, and phthalocyanine blue (other pigments). Examples of other pigments include inorganic pigments such as aluminum hydroxide, silica, red iron oxide, antimony red, cadmium red, cadmium yellow, cobalt blue, Prussian blue, and ultramarine blue, and organic pigments such as soluble azo pigments, insoluble azo pigments, azo lake pigments, condensed azo pigments, and condensed polycyclic pigments.

[0038] The pigment content in the separation layer may be, for example, 1% by mass or more, 10% by mass or more, or 20% by mass or more based on the total mass of the separation layer from the viewpoint of obtaining better release properties. Also, the pigment content in the separation layer may be, for example, 85% by mass or less, 80% by mass or less, or 70% by mass or less based on the total mass of the separation layer from the viewpoint of preventing the pigment from adhering to other materials, manufacturing machines, etc. during the manufacturing process.

[0039] In order to obtain the above-mentioned effects more significantly, the content of other pigments in the separation layer may be, for example, less than 50% by mass, based on the total mass of the pigments, preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less, and may be 10% by mass or less, 5% by mass or less, or 1% by mass or less, or may be 0% by mass.

[0040] The separation layer may further contain a resin component, for example, a layer in which a pigment is dispersed in the resin component. The resin component may be a binder resin contained in the coating liquid for forming the separation layer or a cured product thereof. Examples of the binder resin include urethane resin (polyurethane resin), polyurea resin, acrylic resin (polyacrylate resin), polyester resin, polyamide resin, and cured products thereof. Inks available on the market often contain urethane resin.

[0041] The separation layer containing the cured product of the binder resin can be formed using a coating liquid containing the binder resin and a curing agent. The curing agent may be appropriately selected depending on the type of the binder resin. For example, when the binder resin contains a urethane resin, the curing agent may be, for example, Coronate L.

[0042] From the viewpoint of further improving the adhesive strength with the film-like substrate, the binder resin may have a glass transition temperature of, for example, 0° C. or lower, −10° C. or lower, −20° C. or lower, or −30° C. or lower. The binder resin may have a glass transition temperature of, for example, −70° C. or higher, or −60° C. or higher.

[0043] The separation layer can be formed using a commercially available ink containing a pigment, or a coating liquid obtained by adding a curing agent to the ink. Examples of commercially available inks containing carbon black include R black 1000 of the Lamiall Mark III series (manufactured by Sakata Inx Corporation) and F220 795 black of the Lamic series (manufactured by Dainichi Seika Chemicals Mfg. Co., Ltd.). Examples of commercially available inks containing titanium oxide include R white 110 of the Lamiall Mark III series (manufactured by Sakata Inx Corporation), F220 701 white of the Lamic series (manufactured by Dainichi Seika Chemicals Mfg. Co., Ltd.), and R61S white of the Lamistar series (manufactured by Toyo Ink Co., Ltd.). Examples of commercially available inks containing phthalocyanine blue include R indigo 800 of the Lamiall Mark III series (manufactured by Sakata Inx Corporation) and F220 739 indigo of the Lamic series (manufactured by Dainichi Seika Chemicals Mfg. Co., Ltd.).

[0044] The thickness of the separation layer may be, for example, 0.01 μm or more, 0.1 μm or more, or 0.5 μm or more. The thickness of the separation layer may be, for example, 5 μm or less, 3 μm or less, or 2 μm or less.

[0045] In a preferred embodiment, the separation layer may be a layer having a tensile stress at break of less than 4 MPa (hereinafter also referred to as separation layer (A)). A double-sided pressure-sensitive adhesive tape having such a separation layer has excellent impact resistance after bonding and can bond an adherend more firmly.

[0046] The separation layer may be, for example, a coating film of a coating liquid containing a pigment and a binder resin (hereinafter, also referred to as coating liquid (a)), and may be a layer containing a pigment and a binder resin. Such a separation layer has a low tensile stress at break (for example, less than 4 MPa), and therefore can be suitably used as the above-mentioned separation layer (A).

[0047] The content of the pigment in the coating liquid (a) may be, for example, 1% by mass or more, 10% by mass or more, or 20% by mass or more based on the total amount of solids. Also, the content of the pigment in the coating liquid (a) may be, for example, 85% by mass or less, 80% by mass or less, or 70% by mass or less based on the total amount of solids.

[0048] The content of the binder resin in the coating liquid (a) may be, for example, 15% by mass or more, 20% by mass or more, or 25% by mass or more based on the total amount of solids. The content of the binder resin in the coating liquid (a) may be, for example, 99% by mass or less, 90% by mass or less, 80% by mass or less, 70% by mass or less, or 60% by mass or less based on the total amount of solids.

[0049] The solvent for the coating liquid (a) is not particularly limited, and examples of known organic solvents that can be used include aromatic organic solvents such as toluene and xylene; ketone organic solvents such as methyl ethyl ketone and methyl isobutyl ketone; ester organic solvents such as ethyl acetate, n-propyl acetate, isopropyl acetate and isobutyl acetate; alcohol organic solvents such as methanol, ethanol, n-propanol, isopropanol and n-butanol; and glycol ether solvents such as ethylene glycol monopropyl ether and propylene glycol monomethyl ether, and these may be used in combination.

[0050] In another preferred embodiment, the separation layer may be a layer having a tensile stress at break of 4 MPa or more and a tensile elongation at break of 360% or less (hereinafter, also referred to as separation layer (B)). In a double-sided pressure-sensitive adhesive tape having such a separation layer, re-adhesion after peeling is unlikely to occur when the interface between the separation layer and the film-like substrate is peeled off, so that the entire interface can be peeled off more smoothly.

[0051] The separation layer may be, for example, a coating film of a coating liquid (hereinafter also referred to as coating liquid (b)) containing a pigment, a binder resin, and a curing agent, and may be a layer containing a cured product of the pigment and the binder resin. Such a separation layer has a high tensile stress at break (e.g., 4 MPa or more) and a low tensile elongation at break (e.g., 360% or less), and therefore can be suitably used as the above-mentioned separation layer (B).

[0052] The content of the pigment in the coating liquid (b) may be, for example, 1% by mass or more, 10% by mass or more, or 20% by mass or more based on the total amount of solids. Also, the content of the pigment in the coating liquid (b) may be, for example, 85% by mass or less, 80% by mass or less, or 70% by mass or less based on the total amount of solids.

[0053] The content of the binder resin in the coating liquid (b) may be, for example, 15% by mass or more, 20% by mass or more, or 25% by mass or more based on the total amount of solids. The content of the binder resin in the coating liquid (b) may be, for example, 99% by mass or less, 90% by mass or less, 80% by mass or less, 70% by mass or less, or 60% by mass or less based on the total amount of solids.

[0054] The content of the curing agent in the coating liquid (b) may be adjusted appropriately depending on the type of binder resin, for example, to satisfy the above-mentioned values ​​of tensile stress at break and tensile elongation at break. The content of the curing agent in the coating liquid (b) may be, for example, 0.01 parts by mass or more, 0.03 parts by mass or more, or 0.05 parts by mass or more, based on the total amount of solids. The content of the curing agent in the coating liquid (b) may be, for example, 15 parts by mass or less, or 10 parts by mass or less, based on the total amount of solids.

[0055] The solvent for the coating liquid (b) is not particularly limited, and examples of the solvent that can be used include known organic solvents such as aromatic organic solvents such as toluene and xylene; ketone organic solvents such as methyl ethyl ketone and methyl isobutyl ketone; ester organic solvents such as ethyl acetate, n-propyl acetate, isopropyl acetate and isobutyl acetate; alcohol organic solvents such as methanol, ethanol, n-propanol, isopropanol and n-butanol; and glycol ether solvents such as ethylene glycol monopropyl ether and propylene glycol monomethyl ether, and these may be used in combination.

[0056] In the double-sided pressure-sensitive adhesive tape of the present embodiment, the layer located between the first pressure-sensitive adhesive layer and the film-like substrate may be collectively referred to as an intermediate layer. The intermediate layer may be a single-layer structure having only a separation layer, or may be a multilayer structure having a separation layer and a layer other than the separation layer (for example, an auxiliary layer described later).

[0057] The double-sided pressure-sensitive adhesive tape of the present embodiment may further include an auxiliary layer on the side of the separation layer opposite to the film-like substrate (i.e., the side on the first pressure-sensitive adhesive layer side). The auxiliary layer may be a layer for enhancing adhesion between the first pressure-sensitive adhesive layer and the separation layer.

[0058] The auxiliary layer may be a layer laminated directly onto the first adhesive layer, or a separation layer may be laminated directly onto the auxiliary layer.

[0059] The auxiliary layer may be, for example, a layer containing a resin component. Examples of the resin component in the auxiliary layer include the same resin components as those exemplified as the resin component in the separation layer.

[0060] The resin component in the auxiliary layer is not particularly limited, but from the viewpoint of excellent tensile shear strength, a cured product of a binder resin is preferred.

[0061] The auxiliary layer may be, for example, a layer containing a pigment, or a layer containing a resin component and a pigment. The pigment in the auxiliary layer may be the same as that exemplified as the pigment in the separation layer. When dismantling the double-sided adhesive tape, it is necessary to insert a flat tool from the side of the tape so that the interface between the separation layer and the film-like substrate is peeled off. If the double-sided adhesive tape has an auxiliary layer containing a pigment near the separation layer, the auxiliary layer serves as a guide for the insertion location of the tool, making dismantling even easier.

[0062] The pigment in the auxiliary layer is not particularly limited, and may be at least one selected from the group consisting of carbon black, titanium oxide, and phthalocyanine blue, or may be any of the other pigments described above.

[0063] The thickness of the auxiliary layer may be, for example, 0.01 μm or more, 0.1 μm or more, or 0.5 μm or more. The thickness of the auxiliary layer may be, for example, 5 μm or less, 3 μm or less, or 2 μm or less.

[0064] The total thickness of the intermediate layer may be, for example, 0.02 μm or more, 0.2 μm or more, or 1.0 μm or more. The total thickness of the intermediate layer may be 10 μm or less, 6 μm or less, or 4 μm or less.

[0065] The film-like substrate is a layer provided between the separation layer and the second pressure-sensitive adhesive layer, and is laminated directly on the separation layer. The film-like substrate and the separation layer are in contact with each other, and the interface between them is peeled off during dismantling as described below.

[0066] The film-like substrate may be in contact with the second pressure-sensitive adhesive layer. The surface of the film-like substrate that is in contact with the second pressure-sensitive adhesive layer may be corona-treated.

[0067] The material of the film-like substrate is not particularly limited, and may be, for example, a resin such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethylene (PE), polypropylene (PP), acrylic, polyimide (PI), polyphenylene sulfide (PPS), polycarbonate (PC), etc.

[0068] The thickness of the film-like substrate may be, for example, 10 μm or more, 12 μm or more, 25 μm or more, or 38 μm or more. The thickness of the film-like substrate may be, for example, 100 μm or less, 75 μm or less, or 50 μm or less.

[0069] The second pressure-sensitive adhesive layer is a layer mainly composed of a pressure-sensitive adhesive, and may be a layer containing a pressure-sensitive adhesive. The pressure-sensitive adhesive constituting the second pressure-sensitive adhesive layer may be, for example, an acrylic pressure-sensitive adhesive, a rubber pressure-sensitive adhesive, a urethane pressure-sensitive adhesive, a silicone pressure-sensitive adhesive, a block copolymer pressure-sensitive adhesive, etc., and is preferably an acrylic pressure-sensitive adhesive. The second pressure-sensitive adhesive layer may have the same structure as the first pressure-sensitive adhesive layer, or may have a different structure. The second pressure-sensitive adhesive layer may be a layer containing one type of pressure-sensitive adhesive, or may be a layer containing two or more types of pressure-sensitive adhesive. The second pressure-sensitive adhesive layer may be a foam. The second pressure-sensitive adhesive layer may be one layer or two or more layers.

[0070] The thickness of the second pressure-sensitive adhesive layer (when the second pressure-sensitive adhesive layer is composed of multiple layers, the thickness of the entire second pressure-sensitive adhesive layer) is not particularly limited and may be, for example, 10 μm or more or 20 μm or more. The thickness of the second pressure-sensitive adhesive layer may be, for example, 100 μm or less, 80 μm or less, or 60 μm or less.

[0071] Fig. 1 is a cross-sectional view showing an outline of one embodiment of a double-sided pressure-sensitive adhesive tape. The double-sided pressure-sensitive adhesive tape 100 in Fig. 1 includes a first pressure-sensitive adhesive layer 10, a separation layer 20, a film-like substrate 30, and a second pressure-sensitive adhesive layer 40. In the double-sided pressure-sensitive adhesive tape 100, the separation layer 20 is laminated directly on the first pressure-sensitive adhesive layer 10, the film-like substrate 30 is laminated directly on the separation layer 20, and the second pressure-sensitive adhesive layer 40 is laminated directly on the film-like substrate 30.

[0072] In the double-sided pressure-sensitive adhesive tape 100, another layer may be interposed between the first pressure-sensitive adhesive layer 10 and the separation layer 20. In addition, another layer may be interposed between the film-like substrate 30 and the second pressure-sensitive adhesive layer 40.

[0073] Fig. 2 is a cross-sectional view showing an outline of another embodiment of a double-sided adhesive tape. The double-sided adhesive tape 101 in Fig. 2 includes a first adhesive layer 11, an intermediate layer consisting of an auxiliary layer 51 and a separation layer 21, a film-like substrate 31, and a second adhesive layer 41. In the double-sided adhesive tape 101, the auxiliary layer 51 is laminated directly on the first adhesive layer 11, the separation layer 21 is laminated directly on the auxiliary layer 51, the film-like substrate 31 is laminated directly on the separation layer 21, and the second adhesive layer 41 is laminated directly on the film-like substrate 31.

[0074] In the double-sided pressure-sensitive adhesive tape 101, another layer may be interposed between the first pressure-sensitive adhesive layer 11 and the auxiliary layer 51. In addition, another layer may be interposed between the auxiliary layer 51 and the separation layer 21. In addition, another layer may be interposed between the film-like substrate 31 and the second pressure-sensitive adhesive layer 41.

[0075] (Goods) The article of the present embodiment includes a first member, a second member, and a joint portion that joins the first member and the second member. The joint portion has a first region that is made of the first double-sided pressure-sensitive adhesive tape that includes the above-mentioned separation layer (A), and a second region that is made of the second double-sided pressure-sensitive adhesive tape that includes the above-mentioned separation layer (B). By using the first double-sided pressure-sensitive adhesive tape and the second double-sided pressure-sensitive adhesive tape in combination, it is possible to achieve both excellent impact resistance and excellent ease of dismantling.

[0076] In the article of the present embodiment, the first member and the second member are joined in the first region with a first double-sided adhesive tape that has excellent impact resistance after bonding and can more firmly bond the adherend, so that peeling of the first member and the second member due to impact is sufficiently suppressed. Also, in the article of the present embodiment, the first member and the second member are joined in the second region with a second double-sided adhesive tape that has superior ease of dismantling, so that the first member and the second member can be easily separated by dismantling starting from the second region.

[0077] When the joint has a corner (edge), the corner is preferably the first region, whereby the corner, which is easily peeled off, is firmly adhered by the first double-sided adhesive tape, and impact resistance after adhesion is further improved.

[0078] FIG. 3(a) is a cross-sectional view showing an outline of one embodiment of the article, and FIG. 3(b) is a cross-sectional view showing a cross section taken along line AA in FIG. 3(a).

[0079] 3(a) includes a first member 80, a second member 90, and a joint 110 that joins the first member 80 and the second member 90. The joint 110 has a first region 200 formed of a first double-sided adhesive tape, and a second region 300 formed of a second double-sided adhesive tape.

[0080] 3(b), the joint 110 of the article 500 is formed in a rectangular frame shape, with the first regions 200 formed at the corners and the second regions 300 formed between the corners (sides). The article 500 has excellent impact resistance because the four corners are firmly bonded by the first regions 200. Furthermore, by inserting a tool having a flat portion into the second region 300, the first member 80 and the second member 90 of the article 500 can be easily separated and dismantled.

[0081] In the article 500, the joint 110 has a rectangular frame shape, but the shape of the joint in the article of this embodiment is not limited to this.

[0082] In article 500, the first region 200 and the second region 300 are arranged adjacent to each other, but in the article of this embodiment, the first region and the second region may be arranged spaced apart from each other, or may be arranged so that they overlap partially.

[0083] The article of the present embodiment may be, for example, a monitor of a personal computer or the like, an electronic board, a sensor, etc. That is, the double-sided pressure-sensitive adhesive tape of the present embodiment may be used to fix members constituting these articles.

[0084] (Manufacturing method of double-sided adhesive tape) The double-sided adhesive tape of this embodiment may be manufactured, for example, by a manufacturing method including a separation layer formation step of applying a coating liquid containing a pigment directly onto one side of a film-like substrate to form a separation layer containing the pigment, and a first adhesive layer formation step of laminating a first adhesive layer on the separation layer.

[0085] In the above-mentioned manufacturing method, the separation layer forming step may be a step of directly applying the coating liquid for forming the separation layer on one side of the film-like substrate to form the separation layer.The second pressure-sensitive adhesive layer may be formed on the film-like substrate before the separation layer forming step, or may be formed on the film-like substrate after the separation layer forming step.The first pressure-sensitive adhesive layer forming step may be performed before or after the step of forming the second pressure-sensitive adhesive layer.

[0086] The second adhesive layer can be formed, for example, by directly applying the adhesive solution for forming the second adhesive layer onto the surface of the substrate. The application device for applying the adhesive solution for forming the second adhesive layer onto the surface of the substrate may be, for example, a coater such as a bar coater, a knife coater, a roll coater, or a die coater. When one surface of the film-like substrate is surface-treated (for example, corona-treated), it is preferable that the film-like substrate and the second adhesive layer are bonded so that the corona-treated surface of the film-like substrate faces the second adhesive layer.

[0087] The separation layer can be formed, for example, by applying a coating liquid for forming the separation layer onto one surface of the film-like substrate (for example, onto the surface not bonded to the second adhesive layer) and drying and solidifying it. The method of applying the coating liquid is not particularly limited, and the coating liquid may be applied by a coater such as a gravure coater, or may be applied by spraying the coating liquid. The coating liquid may be the above-mentioned ink or a mixture of the ink and a curing agent, or the viscosity may be adjusted by mixing the ink or the like with a diluting solvent.

[0088] The above-mentioned manufacturing method may further include an auxiliary layer forming step of forming an auxiliary layer on the separation layer before the first pressure-sensitive adhesive layer forming step. In this case, the first pressure-sensitive adhesive layer forming step may be a step of laminating the first pressure-sensitive adhesive layer on the auxiliary layer.

[0089] The auxiliary layer can be formed, for example, by applying a coating liquid for forming the auxiliary layer onto the separation layer and drying and solidifying it. The method for applying the coating liquid is not particularly limited, and the coating liquid may be applied by a coater such as a gravure coater, or by spraying the coating liquid. The coating liquid may be the above-mentioned ink or a mixture of the ink and a curing agent, or the viscosity may be adjusted by mixing the ink or the like with a dilution solvent.

[0090] The first pressure-sensitive adhesive layer can be formed, for example, by laminating a pressure-sensitive adhesive layer formed on the release surface of a liner onto a separation layer or an auxiliary layer. The first pressure-sensitive adhesive layer may also be formed by laminating a commercially available foam tape onto the separation layer or the auxiliary layer.

[0091] (How to disassemble the double-sided adhesive tape) After bonding the members, the double-sided pressure-sensitive adhesive tape of this embodiment can be disassembled, for example, by the following method.

[0092] 4 is a diagram for explaining one embodiment of a method for dismantling a double-sided adhesive tape. The method for separating a first member 50 and a second member 60 joined with a double-sided adhesive tape 100 (which can also be called a method for dismantling an article including the first member 50 and the second member 60) includes, for example, a step of inserting a flat tool 70 from a side surface of the double-sided adhesive tape 100 joining the first member 50 and the second member 60, and peeling off the interface between the separation layer 20 and the film-like substrate 30.

[0093] The flat tool 70 may be any tool having a flat portion, such as a scraper, a knife, etc. The material of the flat portion is not particularly limited, and may be made of metal, resin, etc.

[0094] The items to be dismantled are not limited to those made up of two components, but may be made up of three or more components. The components may all be made of the same material, or any or all of them may be made of different materials.

[0095] After inserting the flat portion of the flat device 70 into the side of the double-sided adhesive tape 100 so as to be approximately parallel to the interface between the separation layer 20 and the film-like substrate 30, for example, the flat portion of the flat device 70 can be moved along the interface between the separation layer 20 and the film-like substrate 30 to efficiently peel the separation layer 20 from the film-like substrate 30. In addition, by rotating the inserted flat portion, the peeling surface between the separation layer 20 and the film-like substrate 30 can be expanded and peeled off.

[0096] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. EXAMPLES

[0097] The present invention will be described in more detail below using examples and comparative examples, but the present invention is not limited to the following examples.

[0098] (Example 1-1) 80 parts by mass of an ink containing a pigment (titanium oxide) and a urethane resin (Lamiall Mark III R61S white, manufactured by Sakata Inx Corporation) and 20 parts by mass of an ink containing a pigment (carbon black) and a urethane resin (Lamiall Mark III R ink 1000, manufactured by Sakata Inx Corporation) were mixed to obtain 100 parts by mass of an ink mixture, and a dilution solvent (a mixture of 60 parts by mass of methyl ethyl ketone, 30 parts by mass of toluene, and 10 parts by mass of isopropyl alcohol) was added and stirred so that the viscosity was such that the steady flow of the mixed liquid from the orifice ceased in 20 seconds when measuring the viscosity using a Zahn cup No. 3, and the coating liquid for forming a separation layer was prepared.

[0099] A mixture was obtained by mixing 100 parts by mass of an ink containing a pigment (titanium oxide) and a urethane resin (Lamic F220 701 white, manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) with 3 parts by mass of a curing agent (Coronate L-45, manufactured by Tosoh Corporation). A dilution solvent (a mixture of 60 parts by mass of methyl ethyl ketone, 30 parts by mass of toluene, and 10 parts by mass of isopropyl alcohol) was then added and stirred to obtain a viscosity at which the steady flow of the mixed liquid from the orifice ceased in 20 seconds when measuring the viscosity using a Zahn cup No. 3, thereby preparing a coating liquid for forming an auxiliary layer.

[0100] The coating liquid for forming the separation layer and the coating liquid for forming the auxiliary layer prepared above were set in a gravure printing machine (multicolor printing machine, 2 m long inside the dryer after each gravure coating) equipped with gravure rolls (pyramid type, 150 lines, plate depth 40 μm) for the separation layer and the auxiliary layer, in the order of coating: separation layer, auxiliary layer. A 50 μm thick PET film (EMBLET S-50, manufactured by Unitika Ltd.) with only one side corona-treated was used as the film-like substrate, and the coating liquid for forming the separation layer was applied to the uncorona-treated film-like substrate at a line speed of 50 m / min. The coating liquid for forming the auxiliary layer was then applied to the separation layer at a line speed of 50 m / min and dried in a dryer at 80° C. to form an intermediate layer (separation layer and auxiliary layer) each having a thickness of 0.8 to 1.5 μm. The coated roll was then aged at 40° C. for 24 hours.

[0101] 100 parts by mass of adhesive (SK-Dyne1503, Soken Chemical Industries, Ltd.) was mixed with 3 parts by mass of curing agent (Coronate L-45, Tosoh Corporation) and stirred to obtain an adhesive composition. The obtained adhesive composition was applied to the corona-treated surface (opposite surface to the separation layer) of the film-like substrate with a knife coater and dried for 3 minutes in a drying device at 65°C. This resulted in a laminate in which a second adhesive layer having a thickness of 40 μm, a film-like substrate, a separation layer, and an auxiliary layer were laminated in this order. Next, in order to protect the second adhesive layer, a silicone-treated PET film (Purex A50, Toyobo Film Solutions Co., Ltd.) was laminated on the second adhesive layer.

[0102] An adhesive layer of 0.8 mm thick foam tape (Y-4825K-08, manufactured by 3M) was placed on the auxiliary layer of the obtained laminate, taking care not to trap air bubbles, to form a first adhesive layer, and the tape was pressed using a squeegee to produce a double-sided adhesive tape.

[0103] (Example 2-1) A double-sided adhesive tape was prepared in the same manner as in Example 1-1, except that 100 parts by mass of an ink (Lamiall Mark III R Indigo 800, manufactured by Sakata Inks Corporation) containing a pigment (phthalocyanine blue) and a urethane resin was used as the ink for preparing the coating liquid for forming the separation layer, and the amount of the curing agent in the coating liquid for forming the auxiliary layer was 1 part by mass.

[0104] (Example 2-2) A double-sided adhesive tape was produced in the same manner as in Example 2-1, except that a 0.2 mm thick foam tape (manufactured by 3M, Y-4914) was used to form the first adhesive layer.

[0105] (Example 2-3) A double-sided adhesive tape was produced in the same manner as in Example 2-1, except that a 0.25 mm thick foam tape (86425, manufactured by 3M) was used to form the first adhesive layer.

[0106] (Example 3-1) A double-sided adhesive tape was produced in the same manner as in Example 1-1, except that 100 parts by mass of an ink containing a pigment (phthalocyanine blue) and a urethane resin (Lamiall Mark III R Indigo 800, manufactured by Sakata Inks Corporation) was used as the ink for preparing the coating liquid for forming the separation layer, and the amount of the curing agent in the coating liquid for forming the auxiliary layer was changed to 2 parts by mass.

[0107] (Example 3-2) A double-sided adhesive tape was produced in the same manner as in Example 3-1, except that a 0.2 mm-thick foam tape (manufactured by 3M, Y-4914) was used to form the first adhesive layer.

[0108] (Example 3-3) A double-sided adhesive tape was produced in the same manner as in Example 3-1, except that a 0.25 mm thick foam tape (86425, manufactured by 3M) was used to form the first adhesive layer.

[0109] (Example 4-1) A double-sided adhesive tape was prepared in the same manner as in Example 1-1, except that 100 parts by mass of a mixture of an ink containing a pigment (phthalocyanine blue) and a urethane resin (Lamiall Mark III R Indigo 800, manufactured by Sakata Inx Corporation) and an ink containing a pigment (carbon black) and a urethane resin (Lamiall Mark III R Black 1000, manufactured by Sakata Inx Corporation) in a ratio of 75:25 (mass ratio) was used as the ink used to prepare the coating liquid for forming the separation layer.

[0110] (Example 4-2) A double-sided adhesive tape was prepared in the same manner as in Example 4-1, except that a 0.25 mm thick foam tape (86425, manufactured by 3M) was used to form the first adhesive layer.

[0111] (Example 5-1) A double-sided adhesive tape was prepared in the same manner as in Example 1-1, except that 100 parts by mass of an ink mixture was used in which an ink containing a pigment (phthalocyanine blue) and a urethane resin (manufactured by Sakata Inx Corporation, Lamiall Mark III R Indigo 800) and an ink containing a pigment (carbon black) and a urethane resin (manufactured by Sakata Inx Corporation, Lamiall Mark III R Black 1000) were mixed in a ratio of 75:25 (mass ratio) as the ink used for preparing the coating liquid for forming the separation layer, and an ink containing a pigment (carbon black) and a urethane resin (manufactured by Sakata Inx Corporation, Lamiall Mark III R Black 1000) was used as the ink used for preparing the coating liquid for forming the auxiliary layer.

[0112] (Example 5-2) A double-sided adhesive tape was prepared in the same manner as in Example 5-1, except that a 0.2 mm thick foam tape (manufactured by 3M, Y-4914) was used to form the first adhesive layer.

[0113] (Example 6-1) A double-sided adhesive tape was prepared in the same manner as in Example 1-1, except that 100 parts by mass of an ink containing a pigment (carbon black) and a urethane resin (Lamic F220 795 ink, manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) was used as the ink for preparing the coating liquid for forming the separation layer, and an auxiliary layer was not formed.

[0114] (Example 7-1) A double-sided adhesive tape was prepared in the same manner as in Example 1-1, except that the coating liquid for forming the separation layer was a mixture obtained by adding and stirring 100 parts by mass of an ink (Lamic F220 739 indigo manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) containing a pigment (phthalocyanine blue) and a urethane resin, 1 part by mass of a curing agent (Coronate L-45 manufactured by Tosoh Corporation), and 100 parts by mass of a dilution solvent (a mixture of methyl ethyl ketone:toluene = 2:1 (mass ratio)), and that the amount of the curing agent in the coating liquid for forming the auxiliary layer was 1 part by mass.

[0115] (Example 8-1) A double-sided pressure-sensitive adhesive tape was prepared in the same manner as in Example 7-1, except that the amount of the curing agent in the coating liquid for forming the auxiliary layer was changed to 2 parts by mass.

[0116] (Example 9-1) A double-sided pressure-sensitive adhesive tape was produced in the same manner as in Example 7-1, except that the amount of the curing agent in the coating liquid for forming the separation layer was changed to 5 parts by mass.

[0117] (Example 9-2) A double-sided adhesive tape was produced in the same manner as in Example 9-1, except that a 0.2 mm-thick foam tape (manufactured by 3M, Y-4914) was used to form the first adhesive layer.

[0118] (Example 9-3) A double-sided adhesive tape was produced in the same manner as in Example 9-1, except that a 0.25 mm thick foam tape (86425, manufactured by 3M) was used to form the first adhesive layer.

[0119] (Example 10-1) A double-sided adhesive tape was prepared in the same manner as in Example 7-1, except that the amount of curing agent in the coating liquid for forming the separation layer was 5 parts by mass, and the amount of curing agent in the coating liquid for forming the auxiliary layer was 2 parts by mass.

[0120] (Example 10-2) A double-sided adhesive tape was produced in the same manner as in Example 10-1, except that a 0.2 mm-thick foam tape (manufactured by 3M, Y-4914) was used to form the first adhesive layer.

[0121] (Example 10-3) A double-sided adhesive tape was produced in the same manner as in Example 10-1, except that a 0.25 mm thick foam tape (86425, manufactured by 3M) was used to form the first adhesive layer.

[0122] (Example 11-1) A double-sided adhesive tape was prepared in the same manner as in Example 7-1, except that the amount of curing agent in the coating liquid for forming the separation layer was 3 parts by mass, and the amount of curing agent in the coating liquid for forming the auxiliary layer was 3 parts by mass.

[0123] (Example 11-2) A double-sided adhesive tape was produced in the same manner as in Example 11-1, except that a 0.2 mm-thick foam tape (manufactured by 3M, Y-4914) was used to form the first adhesive layer.

[0124] (Example 11-3) A double-sided adhesive tape was produced in the same manner as in Example 11-1, except that a 0.25 mm thick foam tape (86425, manufactured by 3M) was used to form the first adhesive layer.

[0125] (Example 12-1) A double-sided adhesive tape was prepared in the same manner as in Example 7-1, except that the amount of curing agent in the coating liquid for forming the separation layer was 5 parts by mass, and the amount of curing agent in the coating liquid for forming the auxiliary layer was 3 parts by mass.

[0126] (Example 13-1) A double-sided adhesive tape was prepared in the same manner as in Example 7-1, except that the amount of the curing agent in the coating liquid for forming the separation layer was 5 parts by mass, an ink containing a pigment (phthalocyanine blue) and a urethane resin (Lamiall Mark III R Indigo 800, manufactured by Sakata Inx Corporation) was used as the ink for preparing the coating liquid for forming the auxiliary layer, and the amount of the curing agent in the coating liquid for forming the auxiliary layer was 3 parts by mass.

[0127] (Example 13-2) A double-sided adhesive tape was produced in the same manner as in Example 13-1, except that a 0.2 mm-thick foam tape (manufactured by 3M, Y-4914) was used to form the first adhesive layer.

[0128] (Example 13-3) A double-sided adhesive tape was produced in the same manner as in Example 13-1, except that a 0.25 mm thick foam tape (86425, manufactured by 3M) was used to form the first adhesive layer.

[0129] (Example 14-1) A double-sided adhesive tape was prepared in the same manner as in Example 7-1, except that the amount of curing agent in the coating liquid for forming the separation layer was 5 parts by mass, an ink containing a pigment (carbon black) and a urethane resin (Lamiall Mark III R ink 1000, manufactured by Sakata Inx Corporation) was used as the ink for preparing the coating liquid for forming the auxiliary layer, and the amount of curing agent in the coating liquid for forming the auxiliary layer was 3 parts by mass.

[0130] (Example 14-2) A double-sided adhesive tape was produced in the same manner as in Example 14-1, except that a 0.2 mm-thick foam tape (manufactured by 3M, Y-4914) was used to form the first adhesive layer.

[0131] (Example 14-3) A double-sided adhesive tape was produced in the same manner as in Example 14-1, except that a 0.25 mm thick foam tape (86425, manufactured by 3M) was used to form the first adhesive layer.

[0132] (Example 15-1) A double-sided adhesive tape was produced in the same manner as in Example 7-1, except that 100 parts by mass of an ink containing a pigment (titanium oxide) and a urethane resin (Lamistar R61S white, manufactured by Toyo Ink Co., Ltd.) was used as the ink used to prepare the coating liquid for forming the separation layer, the amount of curing agent in the coating liquid for forming the auxiliary layer was 5 parts by mass, an ink containing a pigment (carbon black) and a urethane resin (Lamiall Mark III R ink 1000, manufactured by Sakata Inx Corporation) was used as the ink used to prepare the coating liquid for forming the auxiliary layer, and the amount of curing agent in the coating liquid for forming the auxiliary layer was 3 parts by mass.

[0133] (Example 16-1) A double-sided adhesive tape was produced in the same manner as in Example 7-1, except that 100 parts by mass of an ink containing a pigment (titanium oxide) and a urethane resin (Lamistar R61S white, manufactured by Toyo Ink Co., Ltd.) was used as the ink used to prepare the coating liquid for forming the separation layer, the amount of curing agent in the coating liquid for forming the auxiliary layer was 5 parts by mass, an ink containing a pigment (titanium oxide) and a urethane resin (Lamic F220 701 white, manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) was used as the ink used to prepare the coating liquid for forming the auxiliary layer, and the amount of curing agent in the coating liquid for forming the auxiliary layer was 3 parts by mass.

[0134] (Example 17-1) A double-sided adhesive tape was produced in the same manner as in Example 7-1, except that 100 parts by mass of an ink containing a pigment (carbon black) and a urethane resin (Lamic F220 795 ink, manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) was used as the ink for preparing the coating liquid for forming the separation layer, the amount of the curing agent in the coating liquid for forming the separation layer was 5 parts by mass, and no auxiliary layer was formed.

[0135] (Example 17-2) A double-sided adhesive tape was produced in the same manner as in Example 18-1, except that a 0.23 mm thick foam tape (86425, manufactured by 3M) was used to form the first adhesive layer.

[0136] Comparative Example 1 A double-sided adhesive tape was prepared in the same manner as in Example 1-1, except that 100 parts by mass of an ink (Lamic F220 779 grass, manufactured by Dainichi Seikagaku Kogyo Co., Ltd.) containing a pigment (mainly chlorocopper phthalocyanine) and a urethane resin was used as the ink for preparing the coating liquid for forming the separation layer, and an auxiliary layer was not formed.

[0137] Comparative Example 2 A double-sided adhesive tape was produced in the same manner as in Comparative Example 1, except that 5 parts by mass of a curing agent (Coronate L-45, manufactured by Tosoh Corporation) was added to the coating liquid for forming the separation layer.

[0138] Comparative Example 3 A double-sided adhesive tape was prepared in the same manner as in Comparative Example 1, except that 100 parts by mass of an ink containing a pigment (monoazo pigment) and a urethane resin (Lamic F220 950 Vermilion, manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) was used as the ink for preparing the coating liquid for forming the separation layer.

[0139] Comparative Example 4 A double-sided adhesive tape was prepared in the same manner as in Comparative Example 1, except that 100 parts by mass of an ink containing a pigment (monoazo pigment) and a urethane resin (Lamic F220 950 vermilion, manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) was used as the ink for preparing the coating liquid for forming the separation layer, and 5 parts by mass of a curing agent (Coronate L-45, manufactured by Tosoh Corporation) was added to the coating liquid for forming the auxiliary layer.

[0140] Comparative Example 5 A double-sided adhesive tape was produced in the same manner as in Comparative Example 1, except that 100 parts by mass of an ink containing a pigment (a disazo pigment) and a urethane resin (Lamiall Mark III R crimson red 365, manufactured by Sakata Inx Corporation) was used as the ink for preparing the coating liquid for forming the separation layer.

[0141] Comparative Example 6 A double-sided adhesive tape was prepared in the same manner as in Comparative Example 1, except that 100 parts by mass of an ink containing a pigment (disazo pigment) and a urethane resin (Lamiall Mark III R Crimson 365, manufactured by Sakata Inx Corporation) was used as the ink for preparing the coating liquid for forming the separation layer, and 5 parts by mass of a curing agent (Coronate L-45, manufactured by Tosoh Corporation) was added to the coating liquid for forming the auxiliary layer.

[0142] Comparative Example 7 A double-sided adhesive tape was prepared in the same manner as in Example 1-1, except that 100 parts by mass of an ink (Lamic F220 779 grass, manufactured by Dainichi Seikagaku Kogyo Co., Ltd.) containing a pigment (mainly chlorocopper phthalocyanine) and a urethane resin was used as the ink for preparing the coating liquid for forming the separation layer.

[0143] Comparative Example 8 A double-sided adhesive tape was prepared in the same manner as in Example 1-1, except that 100 parts by mass of an ink containing a pigment (monoazo pigment) and a urethane resin (Lamic F220 950 vermilion, manufactured by Dainichiseika Color & Chemicals Co., Ltd.) was used as the ink for preparing the coating liquid for forming the separation layer.

[0144] Comparative Example 9 A double-sided adhesive tape was prepared in the same manner as in Example 1-1, except that 100 parts by mass of an ink containing a pigment (disazo-based pigment) and a urethane resin (Lamiall Mark III R Crimson Red 365, manufactured by Sakata Inx Corporation) was used as the ink for preparing the coating liquid for forming the separation layer.

[0145] The resulting double-sided adhesive tape was evaluated for peel properties, peel strength (adhesive strength in the direction perpendicular to the adhesive surface), tensile shear strength, tensile stress and tensile elongation at the time of breakage of the separation layer, impact resistance, and re-adhesion using the following methods.

[0146] <Peeling properties> A 53mm x 100mm stainless steel plate (SUS304 BA) with a thickness of 1 mm and a 53mm x 100mm glass plate with a thickness of 1.75 mm were prepared. The prepared double-sided adhesive tape was cut to 4mm x 100mm, and the surface of the second adhesive layer was attached to the long edge of the glass plate. Next, the surface of the first adhesive layer of the double-sided adhesive tape was attached to the stainless steel plate so that the glass plate and the stainless steel plate overlap. After leaving it for 20 minutes or more, the stainless steel plate and the glass plate were disassembled using a scraper (peeling spatula R40mm, manufactured by Inoue Tools Co., Ltd.), and the peeling properties were evaluated. When the double-sided adhesive tape was easily peeled off at the interface between the separation layer and the film-like substrate, it was evaluated as "A", when it was peeled off at the interface between the separation layer and the film-like substrate, it was evaluated as "B", and when it was not peeled off at the interface between the separation layer and the film-like substrate, it was evaluated as "C".

[0147] <Peeling force> Two T-shaped blocks made of stainless steel (SUS304) with an adherend surface of 25 mm x 25 mm, a knob extending vertically from the adherend surface of 20 mm, and a thickness of each part of 5 mm were prepared, and a 15 x 15 mm double-sided adhesive tape was attached to the center of one of the T-shaped blocks. The other T-shaped block was attached to the side of the double-sided adhesive tape that was not attached to the T-shaped block so that each knob of the block crossed. In an environment of 24°C, a 5 kg weight was placed on the knob for 1 minute to press the blocks, and then the blocks were left for 72 hours, and the maximum peel force when the T-shaped blocks were peeled off from each other was measured. In addition, the maximum peel force when the first adhesive layer was Y-4825K, Y-4914, and 86425 was 112 N / 15 x 15 mm, 121 N / 15 x 15 mm, and 88 N / 15 x 15 mm, respectively.

[0148] <Tensile shear force> In accordance with JIS Z 1541 (2009), a 15 mm x 15 mm double-sided adhesive tape was attached to a stainless steel plate (SUS304 BA) at 24°C, and the maximum tensile shear strength was measured at a pulling speed of 50 mm / min. The maximum tensile shear strength when the first adhesive layer was Y-4825K, Y-4914, or 86425 was 210 N / 15 x 15 mm, 374 N / 15 x 15 mm, or 199 N / 15 x 15 mm, respectively.

[0149] <Tensile stress and tensile elongation> A coating solution for forming a separation layer was applied to a liner (Oji F-Tex Co., Ltd., 75RL-07) using a comma coater, dried at 65°C for 1 hour, and then cured (thermosetting) at 50°C for 3 days to produce a film with a separation layer of 7 to 13 μm on the liner. The film produced was cut into strips of 15 mm width together with the liner, and adhesive cellulose tape (15 mm width, Nichiban Co., Ltd.) was attached to the front and back of the film at intervals of 25 mm on the film peeled from the liner. If tack remained on the separation layer and handling was difficult, talc was applied to the surface of the separation layer before work. A tensile tester (Orientec Co., Ltd., Tensilon universal testing machine RTG-1225, load cell UR250N D) gripping width 25 mm, tensile speed 50 mm / min) was used to grip the area covered with the cellulose tape and perform a tensile test. The tensile stress and tensile elongation at the time when the separation layer broke were measured.

[0150] <Impact resistance> The prepared double-sided adhesive tape was punched from the first adhesive surface side with a rectangular frame-shaped die having an outer frame side shape of 29 mm x 29 mm (corners curved at 3r) and an inner frame side shape of 19 mm x 19 mm (corners curved at 2r) to obtain a rectangular frame-shaped double-sided adhesive tape with a width of 5 mm. Similarly, a rectangular frame-shaped double-sided adhesive tape with a width of 5 mm was further obtained. The first adhesive layer of one of the rectangular frame-shaped double-sided adhesive tapes was bonded to a stainless steel plate (55 mm x 55 mm, thickness 1 mm) having a 16Φ hole in the center so that the center of the double-sided adhesive tape coincided with the center of the stainless steel plate. Next, the double-sided adhesive tape attached to the stainless steel plate was peeled off at the interface between the separation layer and the film-like substrate using a scraper to remove the second adhesive surface from the film-like substrate. The second adhesive layer of the other rectangular frame-shaped double-sided adhesive tape was bonded to an acrylic plate (30 mm x 30 mm, thickness 2 mm). Next, the double-sided adhesive tape attached to the acrylic plate was peeled off at the interface between the film-like substrate and the separation layer using a scraper to remove the separation layer portion from the first adhesive material. The release surface (separation layer) of the double-sided adhesive tape left attached to the stainless steel plate and the rectangular release surface (film-like substrate) of the double-sided adhesive tape left attached to the acrylic plate were overlapped, and a 10 kg roller was pressed back and forth once each in two directions along the frame of the rectangular frame-shaped double-sided adhesive tape to bond them together. A jig having an inner diameter of 24 mm and a length of 400 mm was placed on the surface of the stainless steel plate opposite the double-sided adhesive tape so that the center of the stainless steel plate and the center of the jig's tube were aligned. A conical weight of 50 g or 100 g was allowed to fall naturally along the tube so as to fall on the acrylic plate attached to the stainless steel plate. The 50 g and 100 g weights were each dropped three times on the acrylic plate (a total of six times) to confirm whether the acrylic plate would fall off the stainless steel plate. Those in which the acrylic plate did not fall off were rated as "A", and those in which it fell off were rated as "B".

[0151] The evaluation results of each of the Examples and Comparative Examples are shown in Table 1. In the table, "-" means that the measurement was not performed or was not possible.

[0152] [Table 1] [Explanation of symbols]

[0153] 10,11...first adhesive layer, 20,21...separation layer, 30,31...film-like substrate, 40,41...second adhesive layer, 50...first member, 51...auxiliary layer, 60...second member, 70...flat device, 80...first member, 90...second member, 100,101...double-sided adhesive tape, 110...joint, 200...first region, 300...second region, 500...article.

Claims

1. A first adhesive layer, a release layer provided on the first adhesive layer and containing a pigment, a film-like substrate directly laminated on the release layer, a second adhesive layer provided on the film-like substrate, and comprising: A double-sided adhesive tape, wherein the pigment contains at least one selected from the group consisting of carbon black, titanium oxide, and phthalocyanine blue.

2. The double-sided adhesive tape according to claim 1, wherein the tensile stress at break of the release layer is less than 4 MPa.

3. The double-sided adhesive tape according to claim 2, wherein the release layer is a coating film of a coating liquid containing the pigment and a binder resin, and is a layer containing the pigment and the cured product of the binder resin.

4. The tensile stress at break of the release layer is 4 MPa or more, The double-sided adhesive tape according to claim 1, wherein the tensile elongation at break of the release layer is 360% or less.

5. The release layer is a coating film of a coating liquid containing the pigment, a binder resin, and a curing agent, The double-sided adhesive tape according to claim 4, which is a layer containing the cured product of the pigment and the binder resin.

6. Further comprising an auxiliary layer directly laminated on the first adhesive layer, The double-sided adhesive tape according to any one of claims 1 to 5, wherein the release layer is directly laminated on the auxiliary layer.

7. A first member, a second member, a joining portion for joining the first member and the second member, and comprising: An article, wherein the joining portion has a first region composed of the double-sided adhesive tape according to claim 2 or 3 and a second region composed of the double-sided adhesive tape according to claim 4 or 5.

8. A method for disassembling two or more members joined by the double-sided adhesive tape according to any one of claims 1 to 5, The method for disassembling includes a step of inserting a flat tool from the side surface of the double-sided adhesive tape to peel the interface between the release layer and the film-like substrate.

Images