Adhesive tape

Abstract

To provide an adhesive tape suitable for attachment to a self-cleaning board, which hardly causes adhesive residue even when exposed to a high-temperature environment or the like and has excellent unevenness followability.SOLUTION: There is provided an adhesive tape attached to a self-cleaning board, which has a base material and an adhesive layer provided on the base material, wherein the adhesive layer contains an acrylic emulsion-based adhesive and an ethylene-vinyl acetate copolymer (EVA) and when the solid content of the acrylic emulsion-based adhesive is defined as 100 pts.mass, the solid content of the ethylene-vinyl acetate copolymer is 8 to 40 pts.mass.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an adhesive tape.

Background Art

[0002] Conventionally, an adhesive tape specialized for masking used for the outer wall of a building or the like has been developed.

[0003] For example, Patent Document 1 discloses a masking tape for outer wall painting, which comprises a back treatment layer, a tape base material, and an adhesive layer, the thickness of the adhesive layer is 50 to 150 μm, and the adhesive is a water-soluble or easily swellable adhesive with water, and is used when painting an uneven outer wall.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In recent years, there have been many buildings whose outer walls are composed of self-cleaning boards. Such self-cleaning boards usually have a hydrophilic surface, enabling the easy removal of dirt adhered by rainwater, showers, etc. Thus, self-cleaning boards have properties different from those of ordinary outer walls. Also, self-cleaning boards are exposed to various temperature environments (especially high-temperature environments). Therefore, when using an adhesive tape according to the prior art as the adhesive tape (e.g., masking tape) to be attached to a self-cleaning board, there has been a problem that the properties of the self-cleaning board itself and the exposure to a high-temperature environment act together, and especially glue residue is likely to occur. In addition, since self-cleaning boards may be subjected to uneven processing in consideration of the design as an outer wall, the adhesive tape to be attached to the self-cleaning board may require excellent uneven following properties.

[0006] Therefore, an object of the present invention is to provide an adhesive tape suitable for attachment to a self-cleaning board that hardly causes glue residue even when exposed to a high-temperature environment or the like and has excellent uneven following properties.

Means for Solving the Problems

[0007] As a result of intensive research by the present inventors, it has been found that by using an adhesive containing a predetermined component, the above problems can be solved, and the present invention has been completed.

[0008] One aspect of the present invention is an adhesive tape. The adhesive tape has a base material and an adhesive layer provided on the base material. The adhesive layer contains an acrylic emulsion-based adhesive and an ethylene-vinyl acetate copolymer (EVA). When the solid content of the acrylic emulsion-based adhesive is 100 parts by mass, the solid content of the ethylene-vinyl acetate copolymer is 8 to 40 parts by mass. Also, the adhesive tape is attached to a self-cleaning board.

[0009] The base material is preferably paper. The self-cleaning board is preferably a photocatalyst board.

Advantages of the Invention

[0010] According to the present invention, there is provided an adhesive tape that is less likely to leave glue residue even when exposed to a high-temperature environment or the like, and that has excellent unevenness followability and is suitable for sticking to a self-cleaning board.

Brief Description of the Drawings

[0011]

Figure 1

Modes for Carrying Out the Invention

[0012] Hereinafter, preferred embodiments of the present invention will be described in detail, but the present invention is not limited thereto.

[0013] In this specification, when a plurality of upper limit values and a plurality of lower limit values are separately described, it is assumed that all numerical ranges that can be freely combined and set from these upper limit values and lower limit values are described.

[0014] In this specification, unless otherwise specified, all kinds of measurements are assumed to have been carried out with the environmental temperature being room temperature (for example, 23°C).

[0015] In this specification, unless otherwise specified, the content and compounding amount of each component, etc. indicate the amount based on the components excluding volatile components (solid content).

[0016] In this specification, when a certain compound is described, it is assumed that its isomers are also described at the same time.

[0017] Hereinafter, the configuration, physical properties / characteristics, manufacturing method, uses, etc. of the adhesive tape according to the present disclosure will be described.

[0018] <<<Configuration>>> FIG. 1 shows a conceptual side view of the adhesive tape 100 according to the present disclosure. As shown in FIG. 1, the adhesive tape 100 according to the present disclosure includes a base material 10 and an adhesive layer 20 provided on the base material 10. Note that FIG. 1 shows the adhesive tape 100 having the adhesive layer 20 only on one side of the base material 10, but the adhesive tape 100 may have the adhesive layer 20 on both sides of the base material 10.

[0019] On the surface of the adhesive layer 20 (the surface opposite to the surface on which the base material 10 is provided), another layer (for example, a release layer such as release paper) may be further laminated as necessary.

[0020] The overall shape of the adhesive tape 100 is not particularly limited, and it may be in the form of a film or a sheet. Further, the adhesive tape 100 may be formed in a long shape or may be wound in a roll shape.

[0021] Hereinafter, the base material 10 and the adhesive layer 20 will be described in detail.

[0022] <<Base Material>> The thickness of the base material is not particularly limited, and it is preferably 50 to 70 μm, and more preferably 55 to 65 μm.

[0023] The material of the base material is not particularly limited. Examples of the material of the base material include papers such as kraft paper, Japanese paper, and crepe paper; non-woven fabrics made of rayon, cotton, acetate, polyethylene (PE), polypropylene (PP), etc.; resin films made of cellophane, vinyl chloride, PE, oriented polypropylene (OPP), polyethylene terephthalate (PET), tetrafluoroethylene, polyimide, polycarbonate (PC), polystyrene (PS), etc.; resin foams made of polyurethane, PE, butyl rubber, etc.; metal foils made of aluminum, copper, etc.; rubber sheets made of natural rubber, SBR, butyl rubber, etc. The material of the base material is preferably paper, and more preferably Japanese paper.

[0024] <<Adhesive Layer>> The thickness of the adhesive layer is not particularly limited, preferably 10 to 100 μm, more preferably 15 to 75 μm, and particularly preferably 20 to 50 μm.

[0025] Also, the ratio of the thickness of the adhesive layer to the thickness of the base material (adhesive layer / base material) is preferably 0.15 to 1.60, and more preferably 0.30 to 0.80.

[0026] By setting the thickness of the adhesive layer within such a range, adhesive residue on the self-cleaning board is suppressed, and it is easy to obtain an adhesive tape with excellent unevenness followability.

[0027] The adhesive layer contains an acrylic emulsion-based adhesive and an ethylene-vinyl acetate copolymer (EVA). The adhesive layer may also contain other components. Hereinafter, each component constituting the adhesive layer will be described.

[0028] <Acrylic Emulsion-based Adhesive> Since the acrylic emulsion-based adhesive is polymerized by emulsion polymerization, generally, it is possible to increase the molecular weight. When the molecular weight is large, the internal energy of the adhesive becomes large, so it is possible to increase the cohesive force.

[0029] The monomer material and monomer composition ratio of the acrylic emulsion-based adhesive are not particularly limited and can be selected in consideration of the adhesiveness to the adherend and the like.

[0030] Monomers include acrylic monomers. Examples of acrylic monomers include (meth)acrylate monomers having a chain alkyl group, (meth)acrylate monomers having an alicyclic alkyl group, (meth)acrylate monomers having a hydroxyl group, acrylic acid-based monomers having a carboxyl group, etc. Furthermore, other monomers copolymerizable with acrylic monomers may be included.

[0031] Examples of the (meth)acrylic acid ester monomer having a chain alkyl group include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, neopentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, isotridecyl (meth)acrylate, tetradecyl (meth)acrylate, isotetradecyl (meth)acrylate, pentadecyl (meth)acrylate, cetyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, isooctadecyl (meth)acrylate, nonadecyl (meth)acrylate, aralkyl (meth)acrylate, and the like.

[0032] Examples of the (meth)acrylic acid ester monomer having an alicyclic alkyl group include (meth)acrylic acid cycloalkyl esters such as cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, cycloheptyl (meth)acrylate, and cyclooctyl (meth)acrylate; (meth)acrylic acid esters having a bicyclic aliphatic hydrocarbon ring such as isobornyl (meth)acrylate; (meth)acrylic acid esters having an aliphatic hydrocarbon ring of three or more rings such as dicyclopentanyl (meth)acrylate, dicyclopentanyloxyethyl (meth)acrylate, tricyclopentanyl (meth)acrylate, 1-adamantyl (meth)acrylate, 2-methyl-2-adamantyl (meth)acrylate, and 2-ethyl-2-adamantyl (meth)acrylate.

[0033] Examples of the (meth)acrylic acid ester monomer having a hydroxyl group include (meth)acrylic acid 2-hydroxyethyl, (meth)acrylic acid 2-hydroxypropyl, (meth)acrylic acid 4-hydroxybutyl, (meth)acrylic acid 6-hydroxyhexyl, (meth)acrylic acid 8-hydroxyoctyl, (meth)acrylic acid 10-hydroxydecyl, (meth)acrylic acid 12-hydroxylauryl, and (meth)acrylic acid esters such as (4-hydroxymethylcyclohexyl)-methyl acrylate.

[0034] Examples of the (meth)acrylic acid-based monomer having a carboxyl group include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, etc. Examples of acrylic monomers include itaconic acid, maleic acid, fumaric acid, crotonic acid, etc.

[0035] Examples of other monomers include styrene, p-chlorostyrene; vinylnaphthalene; ethylenically unsaturated monoolefins such as ethylene, propylene, butylene, isobutylene; vinyl halides such as vinyl chloride, vinyl bromide, vinyl fluoride; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate; vinyl ethers such as vinyl methyl ether, vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone, methyl isopropenyl ketone; N-vinyl compounds such as N-vinylpyrrole, N-vinylcarbazole, N-vinylindole, N-vinylpyrrolidone, etc.

[0036] The above-mentioned monomers can be used alone or in combination of two or more. These monomers are polymerized or copolymerized by an emulsion polymerization method to form a base polymer of an acrylic emulsion-based adhesive.

[0037] The emulsion polymerization method is not particularly limited as long as it does not inhibit the effects of the present disclosure. For example, miniemulsion polymerization, microemulsion polymerization, surfactant-free (soap-free) emulsion polymerization, etc. can be used.

[0038] Regarding emulsion polymerization, there are no particular restrictions, and known and commonly used methods and conditions, etc. are applicable. For example, a mixed monomer, a polymerization initiator, etc. are added to ion-exchanged water in which a surfactant is dissolved, dispersed and emulsified with a high-speed stirrer, and then kept at a constant temperature of 50 to 95 °C and copolymerized under an inert atmosphere. In addition, a method in which a part of the above emulsion is polymerized and the remainder is dropped continuously or intermittently for polymerization may also be used. The concentration of the surfactant based on the total amount of the base polymer is preferably 0.3 to 12% by mass, and the concentration of the total monomers based on the total amount of the base polymer is preferably in the range of 30 to 70% by mass. Examples of the polymerization initiator include persulfates such as ammonium persulfate and potassium persulfate, and water-soluble azo compounds such as azobiscyanovaleric acid. These can be used alone or in combination of a plurality. The polymerization initiator is preferably 0.01 to 5 parts by mass with respect to 100 parts by mass of the total monomers.

[0039] The weight average molecular weight of the base polymer of the acrylic emulsion-based adhesive is not particularly limited. The weight average molecular weight of the base polymer is preferably 10,000 to 3,000,000. The weight average molecular weight of the base polymer can be selected according to the material of the target adherend, etc. When the weight average molecular weight of the base polymer is in such a range, as an adhesive, it has excellent adhesive strength to various adherends, high cohesive force of the adhesive, and therefore, it is difficult for adhesive residue, etc. to occur during repeated use.

[0040] The weight average molecular weight of the base polymer can be adjusted by the polymerization initiator, the polymerization temperature, etc.

[0041] The weight-average molecular weight can be measured by gel permeation chromatography (GPC). The measurement method by the GPC method is possible by a known method. Generally, in a GPC measuring device incorporating a GPC column, the eluent is tetrahydrofuran (THF), the eluent is maintained at 40 ° C, and the eluent after passing through the column is passed through a differential refractive index (RI) detector (for example, the wavelength is set to 254 nm), and the concentration at the retention time is detected. The concentration is converted into the weight-average molecular weight by a calibration curve prepared by measuring several standard styrene samples with known weight-average molecular weights in the same manner in advance.

[0042] As described above, the acrylic emulsion-based adhesive according to the present disclosure forms a base polymer by polymerizing or copolymerizing a monomer as a raw material by emulsion polymerization. Then, generally, the base polymer can be crosslinked with a crosslinking agent to obtain an acrylic emulsion-based adhesive.

[0043] The crosslinking agent used for the base polymer of the acrylic emulsion-based adhesive is not particularly limited as long as it does not inhibit the effects of the present disclosure, and those generally used as crosslinking agents for acrylic resins can be used. When the base polymer has a sufficiently large weight-average molecular weight and sufficient mechanical strength, there are cases where crosslinking may not be particularly necessary, but crosslinking is preferably performed. When the mechanical strength of the base polymer is high, the viscosity of the base polymer also becomes high, and there is a risk that it cannot be sufficiently thinned when coating in a sheet form or performing lamination or the like. Therefore, by adding a crosslinking agent to the base polymer before crosslinking, coating it on a peeled film (or a base material described later), thinning it, and then drying it in a drying furnace while causing a crosslinking reaction, an adhesive that is easily thinned can be obtained, and the production efficiency is high.

[0044] Examples of the crosslinking agent include polyfunctional isocyanate - based crosslinking agents, epoxy - based crosslinking agents, oxazoline - based crosslinking agents, aziridine - based crosslinking agents, metal chelate - based crosslinking agents, melamine resin - based crosslinking agents, peroxide - based crosslinking agents, etc. The crosslinking agent may be either oil - soluble or water - soluble. Also, these crosslinking agents can be used alone or in combination of two or more.

[0045] By crosslinking the base polymer, it becomes possible to improve the adhesive strength to the adherend and to remove the adhesive remaining on the adherend after peeling.

[0046] The degree of crosslinking may be adjusted so that the number of crosslinking points contained in the above - mentioned monomers achieves the desired performance. For example, the degree of crosslinking can be adjusted by adjusting the blending amount of monomers having crosslinking points such as hydroxyl groups.

[0047] The gel fraction of the acrylic emulsion - based adhesive can be measured using a known method. As a general measurement method, the acrylic emulsion - based adhesive is dissolved in a soluble organic solvent such as THF. It is left standing for 24 hours at 25°C, and then the gel fraction is separated using a 200 - mesh metal mesh. The separated gel fraction is dried and its mass is measured. The value obtained by dividing the mass of the separated gel fraction by the mass of the adhesive initially dissolved in the organic solvent can be defined as the gel fraction.

[0048] The glass transition temperature of the acrylic emulsion - based adhesive according to the present disclosure is preferably - 70 to - 20°C, and more preferably - 70 to - 40°C.

[0049] <Ethylene - vinyl acetate copolymer (EVA)> As the ethylene - vinyl acetate copolymer, known and commonly used ones can be used. Also, the ethylene - vinyl acetate copolymer may be a commercially available product.

[0050] In the adhesive layer, when the solid content of the acrylic emulsion-based adhesive is 100 parts by mass, the solid content of ethylene vinyl acetate is preferably 8 parts by mass or more, 10 parts by mass or more, or 15 parts by mass or more. The upper limit value of the solid content of ethylene vinyl acetate is, for example, 40 parts by mass, 30 parts by mass, or 25 parts by mass. By setting the solid content of the ethylene vinyl acetate copolymer within such a range, adhesive residue on the self-cleaning board in a high-temperature environment or the like is suppressed, and it is easy to obtain an adhesive tape excellent in unevenness followability.

[0051] <Other components> Examples of other components include known additives such as tackifying resins, softeners, fillers, antioxidants, heat stabilizers, ultraviolet absorbers, light stabilizers, antistatic agents, flame retardants, foaming agents, colorants, and dyes.

[0052] In the adhesive layer, when the solid content of the acrylic emulsion-based adhesive is 100 parts by mass, the content of other components is 10 parts by mass or less, 5 parts by mass or less, or 3 parts by mass or less. The lower limit value of the content of other components is, for example, 0.1 part by mass, 0.5 part by mass, or 1 part by mass.

[0053] <<<Physical properties / Properties>>> <<Adhesion to SUS>> The adhesion of the adhesive tape to SUS is preferably 1.00 N / 10 mm or more, or 1.10 N / 10 mm or more. The upper limit value of the adhesion to SUS is not particularly limited, but is, for example, 2.50 N / 10 mm, 2.00 N / 10 mm, or 1.90 N / 10 mm. Under the conditions of 23°C and 50% RH, the 180-degree peel force against the SUS plate is measured in accordance with JIS Z 0237.

[0054] <<Tensile strength>> The tensile strength of the adhesive tape is preferably 20.0 N / 15 mm or more, 30.0 N / 15 mm or more, or 40.0 N / 15 mm or more. The upper limit value of the tensile strength is not particularly limited, for example, it is 70.0 N / 15 mm or 60.0 N / 15 mm. Under the conditions of 23°C and 50% RH, in accordance with JIS Z 0237, a tensile strength test is performed, and the maximum load until the test piece is cut is taken as the measured value of the test piece.

[0055] <<Elongation>> The elongation of the adhesive tape is preferably 3% or more, 5% or more, or 7% or more. The upper limit value of the elongation is not particularly limited, for example, it is 15%, 12%, or 10%. Under the conditions of 23°C and 50% RH, in accordance with JIS Z 0237, a tensile strength test is performed, and the amount of deformation in the tensile direction at the time of cutting the test piece is read.

[0056] <<<Manufacturing method>>> The adhesive tape can be manufactured according to known and commonly used methods. For example, an adhesive liquid prepared by adding an organic solvent or the like as necessary to the raw materials constituting the adhesive layer and a base material are prepared. Next, after sequentially performing printing treatment and primer treatment on the surface of the tape base material as necessary, the adhesive liquid is applied using an applicator or the like. Then, heating and drying are performed to obtain an adhesive tape provided with an adhesive layer. It is also possible to prepare an adhesive sheet in which the adhesive layer is formed in advance on a sheet, and laminate this adhesive sheet on the surface of the base material to manufacture the adhesive tape.

[0057] <<<Applications>>> When the adhesive tape according to the present disclosure is attached to a hydrophilic surface, it is difficult for glue residue to occur even when exposed to various temperature environments (for example, high temperature environments such as 50°C or more, 60°C or more, or 80°C or more). Further, the adhesive tape according to the present disclosure has excellent followability to uneven surfaces. Further, the adhesive tape according to the present disclosure is less likely to cause tape breakage during peeling. Therefore, the adhesive tape according to the disclosure is preferably used as an application for being attached to a self-cleaning board. In particular, it is preferably used as a masking tape attached to a self-cleaning board.

[0058] The self-cleaning board is usually a plate-shaped member having hydrophilicity. As a method for imparting hydrophilicity to the plate-shaped member, for example, a method of causing a hydroxyl group or a silanol group to exist on the surface of the plate-shaped member can be mentioned. The specific means for imparting hydrophilicity to the plate-shaped member is not particularly limited. The self-cleaning board may be a plate-shaped member coated with a paint containing a hydrophilic component, or may be a plate-shaped member mixed with a hydrophilic component. Examples of the hydrophilic component include silica and photocatalysts such as titanium oxide. The self-cleaning board (plate-shaped member having a layer containing a photocatalyst on the surface) when the hydrophilic component is a photocatalyst is also referred to as a photocatalyst board.

[0059] The self-cleaning board may have unevenness in consideration of designability and the like. Examples of such unevenness include those in which the height difference of the unevenness is 1 mm or more (for example, 3 to 5 mm), the length of the convex portion is 5 mm or more (for example, 12 to 18 mm), and the length of the concave portion is 5 mm or more (for example, 7 to 13 mm).

Examples

[0060] Next, the present disclosure will be described more specifically with reference to examples and comparative examples. The present disclosure is not limited by these examples in any way.

[0061] <<Adhesive tape>> Table 1 shows the configurations of the adhesive tapes according to each example and each comparative example, and the SUS adhesion, tensile strength, and elongation of each adhesive tape measured based on the above-described method.

[0062]

Table 1

[0063] As shown in Table 1, the adhesive constituting the adhesive layer was prepared by changing the blending amount of ethylene vinyl acetate copolymer (EVA) when the acrylic polymer was 100 parts by mass. The acrylic polymer consists of 2EHA and AA and is a copolymer mainly composed of 2EHA. As the base material (Japanese paper), one with a thickness of 61 μm was used.

[0064] <<Evaluation>> For each adhesive tape, residue evaluation, tape break evaluation, and unevenness followability evaluation were performed. The evaluation results are shown in Table 2.

[0065] <Residue evaluation, tape break evaluation> As adherends, two types of self-cleaning boards, a hydrophilic board and a photocatalyst board, were used. The hydrophilic board is Nichiban's COOL Clarogreen, and the photocatalyst board is Nichiban's COOL Memorya White. Under the conditions of 23°C and 50% RH, the adhesive tape was attached to the adherend, and the adhesive tape was fixed by reciprocating once with a 2 kg pressure roller to obtain an evaluation sample. Then, the evaluation sample was stored in a thermostat at a predetermined temperature condition (23°C or 90°C). Immediately after the sticking time reached the predetermined time, for the evaluation sample, while maintaining each temperature condition, the adhesive tape was rapidly peeled off. The residue on the self-cleaning board after the adhesive tape was rapidly peeled off and the occurrence of tape break in the adhesive tape were confirmed, and the evaluation was performed according to the following evaluation criteria. In addition, the residue evaluation was also performed when the adherend was a SUS plate.

[0066] (Residue evaluation) 4: No residue. 3: The area of the residue (area ratio to the sticking area) is less than 1 / 5. 2: The area of the residue is 1 / 5 or more and less than 1 / 2. 1: The area of the residue is half or more.

[0067] (Tape break evaluation) 〇: No tape break occurred. ×: Tape break occurred.

[0068] <Convexity-following property> Sticky tape was attached to a corrugated siding board (the height difference of the convex and concave parts is 3 to 5 mm, the length of the convex part is 12 to 18 mm, and the length of the concave part is 7 to 13 mm) with a finger, and when the attachment time reached a predetermined time, the number of concave parts that were floating was counted. The floating rate (area rate) with respect to the attached concave part locations was confirmed, and evaluation was performed according to the following criteria.

[0069] 4: The floating rate is 0%. 3: The floating rate is more than 0% and less than 25%. 2: The floating rate is 25% or more and less than 50%. 1: The floating rate is 50% or more.

[0070]

Table 2

[0071] As shown in Table 2, the sticky tape according to each comparative example had a lot of glue residue on the self-cleaning board when exposed to a high-temperature environment, while the sticky tape according to each example had little glue residue. Note that the glue residue of the sticky tape according to each comparative example and the sticky tape according to each example on the SUS plate when exposed to a high-temperature environment was equivalent. From this, it is understood that different performances are required for the glue residue property on the self-cleaning board when exposed to a high-temperature environment and the glue residue property on the SUS plate when exposed to a high-temperature environment. Also, the sticky tape according to each example had a convexity-following property within a practical range. From the above, it is understood that the sticky tape according to each example is an appropriate sticky tape for attaching to a self-cleaning board.

Industrial Applicability

[0072] The sticky tape according to the present disclosure is less likely to leave glue residue even when exposed to a high-temperature environment or the like, and also has excellent convexity-following property. Therefore, it can be preferably used as a masking tape or the like to be attached to a self-cleaning board.

Claims

1. It has a base material and an adhesive layer provided on the base material, The adhesive layer contains an acrylic emulsion-based adhesive and an ethylene vinyl acetate copolymer (EVA), When the solid content of the acrylic emulsion-based adhesive is 100 parts by mass, the solid content of the ethylene vinyl acetate copolymer is 8 to 40 parts by mass, An adhesive tape affixed to a self-cleaning board.

2. The adhesive tape according to Claim 1, wherein the base material is paper.

3. The adhesive tape according to Claim 1 or 2, wherein the self-cleaning board is a photocatalytic board.

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