JP4837360B2 - Double-sided adhesive film - Google Patents

Description

The present invention relates to a double-sided pressure-sensitive adhesive fill beam, in particular, relates to double-sided pressure-sensitive adhesive fill beam with substrate (core material).
In particular, the double-sided pressure-sensitive adhesive film of the present invention is useful for laminating optical members, and also for laminating members related to units including optically anisotropic members such as liquid crystal displays (LCDs). .

In recent years, flat panel displays (FPD) such as LCD and plasma display (PDP) have been widely used. These are laminated with films having various optical functionalities, and these are bonded with an adhesive from the viewpoint of transparency, durability, workability and the like.
To form an adhesive layer,
1. Method of directly applying and drying a pressure-sensitive adhesive solution on a member 2. Method of applying a pressure-sensitive adhesive solution to a release film and drying to form a pressure-sensitive adhesive layer and bonding the members. Method 3. Method of bonding a double-sided pressure-sensitive adhesive film. is there.
In particular, the method of bonding using a double-sided adhesive film without a base material is often used because it is flexible in production and suitable for production in a small variety of products.

However, when a conventional baseless double-sided pressure-sensitive adhesive film is used, the surface of the member is contaminated by the protrusion of the pressure-sensitive adhesive from the end, which impairs the workability and the good product production rate.
In addition, by sticking the physical properties of the adhesive, the problem of protrusion can be avoided to some extent, but by making it hard, problems such as durability have occurred, and satisfactory performance has not been obtained. It was.
In addition, a double-sided pressure-sensitive adhesive film using a PET film as a base material (core material) is known as an adhesive that does not protrude from the end part. It cannot be used in a system using a member having directionality. Moreover, the internal haze which the PET film of a base material has had a problem. The internal haze is haze (turbidity) due to the inside of the film, and when this value is high, it looks visually turbid. Further, since the stretchability and flexibility of the base material (core material) are not sufficient, it may not be able to cope with the stretching of the member accompanying the pasting or temperature / humidity change, resulting in a problem.
In recent years, pressure-sensitive adhesives having reworkability have been used for the purpose of reducing production costs. This is to try to reuse a specific part by performing re-peeling when there is a problem in bonding, but it is not possible to remove only the adhesive when using a baseless double-sided adhesive film, The member on one side could not be reused. Furthermore, since the adhesive strength is low in order to provide reworkability, a so-called adhesive residue phenomenon that the adhesive is peeled off from the member where the adhesive is desired to remain and remains on the adherend tends to occur.
The present invention has been considered under such circumstances, is optically non-oriented, has little protrusion of the adhesive from the end, and can be completely removed from the bonded member by the selected adhesive. , in particular, it has an object to provide a double-sided pressure-sensitive adhesive fill arm used for FPD applications.

The double-sided pressure-sensitive adhesive film of the present invention comprises a base material made of an optically non-oriented and transparent polyurethane resin , a transparent first pressure-sensitive adhesive layer provided on one surface of the base material, A transparent second adhesive layer provided on the other surface, the thickness of the three laminated layers is 55 μm or less, the thickness of the substrate is 3 μm to 20 μm , and the internal HAZE is 1 %. It is as follows.

Moreover, the double-sided pressure-sensitive adhesive film according to claim 2 is the double-sided pressure-sensitive adhesive film according to claim 1 , wherein the first pressure-sensitive adhesive layer is formed of an acrylic pressure-sensitive adhesive, and the first pressure-sensitive adhesive layer side is bonded to an acrylic plate. After holding at 23 ° C. for 1 day, the peeling speed is 300 mm / min, the adhesive strength at 180 ° peeling is 5 N / 25 mm or less, and the acrylic adhesive does not remain on the acrylic plate at the time of peeling. is there.

The double-sided pressure-sensitive adhesive film according to claim 3 is the double-sided pressure-sensitive adhesive film according to claim 1 or 2, wherein the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are acrylic, and the tensile strength according to JIS K7127 is 5 MPa or more. is there.

Moreover, the double-sided pressure-sensitive adhesive film according to claim 4 is the double-sided pressure-sensitive adhesive film according to claim 1 or 2 , wherein the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are different.

  The double-sided pressure-sensitive adhesive film of the present invention has few protrusions from the end face of the pressure-sensitive adhesive, and can be processed with good workability and yield. Moreover, since it has sufficient softness | flexibility and a stretching property, the favorable result was obtained also in the endurance test. In addition, by using a reworkable pressure-sensitive adhesive, only the pressure-sensitive adhesive film can be removed, and any member can be reused when a problem occurs in bonding, contributing to a reduction in manufacturing costs. Was made. Furthermore, by changing the physical properties of the adhesive (first adhesive layer and second adhesive layer) laminated on both sides of the base material, the adhesive force on the adherends on both sides can be controlled, and the adhesive when re-peeling We were able to ensure the remaining prevention. In particular, if the double-sided pressure-sensitive adhesive film is used as an optical double-sided pressure-sensitive adhesive film, the optical anisotropy is not affected even when the optical member is bonded.

An example of a double-sided adhesive fill arm of the present invention will be described with reference to the drawings.
In FIG. 1, 1 is a double-sided pressure-sensitive adhesive film. The double-sided pressure-sensitive adhesive film 1 is an optically non-oriented and transparent base material 2 and a transparent first pressure-sensitive adhesive layer provided on one surface of the base material 2. 3 and the transparent second adhesive layer 4 provided on the other surface of the substrate 2, the thickness T of the laminated three layers is 55 μm or less, and the internal HAZE is 1 % or less. .

The resin used for producing the optically non-oriented and transparent substrate 2 is polyester resin, polyurethane resin, nylon resin, polycarbonate resin, cellulose resin, cycloolefin resin, polymethyl methacrylate. Resin. As a processing method, it can be produced by extrusion molding, inflation molding, solution casting method, etc., but in order not to cause optical anisotropy, it is preferable to produce by each resin solution casting method. Among the above resins, it is particularly preferable to use polyurethane from the viewpoint of tensile strength and transparency.
Polyurethane can also be obtained by applying a polymerization addition reaction after coating as a two-component coating solution of polyol and isocyanate, or by coating a polyurethane resin solution. Further, isocyanate can be added to the polyurethane resin in order to improve the adhesion. These are preferably non-yellowing ones. In addition, a catalyst can also be used for reaction of a polyol and isocyanate. The base material 2 can be prepared by a casting method of each resin solution, but is applied to the release surface of the release-treated film, dried, and then released from the release film as necessary to prevent blocking. A non-oriented base film can be produced relatively easily by laminating the surface to the base surface.
The coating method is not particularly limited, and known methods such as gravure coating, wire bar coating, roll coating, air knife coating, reverse coating, and kiss coating can be used.
The thickness of the base material 2 is 2 μm to 50 μm, and if it is lower than this, the effect of using the base material 2 is difficult to obtain, and if it is higher than this, the thickness as an adhesive film becomes excessive, and the final configuration when actually used It causes troubles and is also uneconomical. Furthermore, a preferable thickness is 3 μm to 20 μm.

The composition which comprises the 1st adhesion layer 3 or the 2nd adhesion layer 4 can also contain the polymer which has (meth) acrylic acid ester as a main component, a crosslinking agent, and also a tackifying resin as needed. . Alternatively, a polymer made of natural rubber or synthetic rubber, silicone rubber, urethane resin, a crosslinking agent, and optionally a tackifying resin may be contained.
The polymer mainly composed of (meth) acrylate used in the present invention is a polymer obtained by polymerizing a monomer mixture mainly composed of (meth) acrylate by a conventionally known polymerization method. is there. As the monomer mixture, a (meth) acrylic acid ester as a main component and a functional group-containing monomer having a functional group that undergoes a crosslinking reaction with a crosslinking agent as an essential component. Other vinyl monomers can also be blended.
Examples of (meth) acrylic acid esters used as the main component include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, iso-butyl (meth) acrylate, and 2-ethylhexyl. (Meth) acrylate, n-octyl (meth) acrylate, iso-octyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxymethyl (meth) acrylate, etc. Can do. These can be used alone or in combination.
Examples of functional group-containing monomers include monomers having a carboxyl group such as (meth) acrylic acid, itaconic acid, maleic acid, fumaric acid, maleic anhydride, β-carboxyethyl acrylate, 2-hydroxyethyl ( Hydroxyl group-containing monomers such as meth) acrylate, 4-hydroxybutyl (meth) acrylate, diethylene glycol mono (meth) acrylate, epoxy group-containing monomers such as glycidyl (meth) acrylate, aminomethyl (meth) acrylate, dimethylaminoethyl (meth) ) Monomers having an amino group such as acrylate, and amide group-containing monomers such as acrylamide and methylol (meth) acrylamide. These can be used alone or in combination.
Furthermore, as other monomers, aromatic vinyl monomers such as styrene, methylstyrene and vinyltoluene, vinyl acetate, vinyl chloride, (meth) acrylonitrile and the like may be copolymerized alone or in combination.

Examples of the rubber-based pressure-sensitive adhesive used in the present invention include natural rubber, styrene-isoprene-styrene block copolymer, styrene-butadiene-styrene block copolymer, styrene-ethylene / butylene-styrene block copolymer, styrene-butadiene rubber, Polybutadiene, polyisoprene, polyisobutylene, butyl rubber, chloroprene rubber, silicone rubber, and urethane resin can be used alone or in combination.
Tackifying resins added to these include terpene resins, α-pinene, terpene phenol copolymers, rosin and rosin derivatives, coumarone-indene resins, hydrocarbon resins, alkylphenol resins, xylene resins, aromatic petroleum resins, aliphatic petroleum Resins, alicyclic petroleum resins and the like can be raised, and one or a mixture of these can be used. Furthermore, an acrylic resin can also be used.
Examples of the crosslinking agent include isocyanate compounds, epoxy compounds, aziridine compounds, metal chelate compounds, and amine compounds. These crosslinking agents can be used alone or in combination of two or more. The addition amount of this crosslinking agent needs to be carefully examined.

A release film can be laminated on the first adhesive layer 3 or the second adhesive layer 4 so that the release surface is aligned with the adhesive layer. In addition to using a release film for the adhesive layer, such as polyethylene, a release film such as silicone or fluorine is applied to the film, or a film with a release film is bonded. Etc. can also be used. In consideration of the influence on the adhesive layer to be combined, those having a smooth surface are preferable, and those having no release component transfer to the surface of the first adhesive layer 3 or the second adhesive layer 4 are preferable. Generally, a PET film coated with a silicone release agent is used.
The first pressure-sensitive adhesive layer 3 or the second pressure-sensitive adhesive layer 4 can be formed by diluting an acrylic pressure-sensitive adhesive or a rubber-based pressure-sensitive adhesive in an organic solvent, and applying and drying the substrate. An emulsion type can also be used. Furthermore, after applying a pressure-sensitive adhesive to the release surface of the release-treated film, it is possible to adopt a method of transferring the pressure-sensitive adhesive by laminating the base film.
The coating method is not particularly limited, and known methods such as gravure coating, wire bar coating, roll coating, air knife coating, reverse coating, and kiss coating can be used.

The thickness of the pressure-sensitive adhesive layer on one side of the substrate is 1 μm to 40 μm, preferably 2 μm to 20 μm. If it is too thin, sufficient performance cannot be obtained, and if it is too thick, not only is it uneconomical, but it also tends to cause the adhesive to protrude from the end, and may cause cohesive failure of the adhesive.
In addition, the 1st adhesion layer 3 or the 2nd adhesion layer 4 of the both sides of the base material 2 can change a physical property by changing a composition and application | coating thickness. By doing so, various designs such as increasing the adhesive force only on one side of the double-sided pressure-sensitive adhesive film 1 can be performed, and effects such as prevention of adhesive residue at the time of peeling can be obtained.

In order to manufacture the double-sided pressure-sensitive adhesive film 1 having this configuration, it is efficient to use a release film in which the peeling force at each interface is controlled.
That is, using the release films A, B, C, and D where the peel force at each interface is A and D <B <C, the base resin solution is applied to the release film B as shown in FIG. The substrate 2 is formed by drying, and the release film A is laminated on the substrate 2 (first step).
Moreover, as shown to Fig.3 (a), the adhesive solution is apply | coated and dried to the release film C, the 1st adhesion layer 3 is formed, and this 1st adhesion layer 3 is obtained at a 1st process. The release film A is peeled off from the base material 2 and bonded together so that the first adhesive layer 3 and the base material 2 are combined as shown in FIG. 3B (second step).
Next, as shown in FIG. 4A, a pressure-sensitive adhesive solution is applied to the release film D and dried to form a second pressure-sensitive adhesive layer 4, which is obtained in the second step. The release film B is peeled off from the obtained base material 2 and, as shown in FIG. 4 (b), the second adhesive layer 4 and the base material 2 are bonded together so that the release film C, The 1st adhesion layer 3, the base material 2, the 2nd adhesion layer 4, and the release film D are laminated | stacked, and a double-sided adhesion film is obtained (3rd process).
According to this method, the non-oriented substrate 2 having a uniform thickness can be easily obtained, and the adhesive layers 3 and 4 can be laminated on both surfaces without damaging the substrate 2.

Hereinafter, the present invention will be described by reference examples, examples and comparative examples. However, the present invention is not limited to the following examples. In addition, the light release PET separator (release film A, release film D), middle release PET separator (release film B), and heavy release PET separator (release film C) described in Reference Examples and Examples are as follows. The corresponding peeling forces are 0.1 N / 50 mm or less, 0.11 to 0.17 N / 50 mm, and 0.18 to 0.4 N / 50 mm (all peeling speed is 300 mm / min).

( Reference Example 1 )
A polyester resin (trade name Byron 200, manufactured by Toyobo Co., Ltd.) was diluted with a solution of toluene / methyl ethyl ketone = 1/1 until the solid content became 25% to obtain a base resin coating solution. This was coated on the release surface of a 38 μm thick medium release PET separator (release film B) having a silicone release treatment on one side and dried at 100 ° C. for 2 minutes to form a 9 μm thick base material layer. Formed. Further, the base film (base material 2) was obtained by attaching the light-release PET separator (release film A) having a thickness of 25 μm having a silicone-type release treatment on one side so that the release faces were matched.

  Next, 100 parts by weight of solid adhesive acrylic adhesive (trade name SK Dyne 1604N, manufactured by Soken Chemical Co., Ltd.) as solids and 2 hardener (trade name Coronate L45, manufactured by Nippon Polyurethane Industry Co., Ltd.) as solids The mixture was prepared in a proportion by weight, and diluted with toluene until the solid content became 25% to obtain a coating solution. It is applied to the release surface of a 50 μm thick heavy release PET separator (release film C) with a silicone release treatment on one side and dried at 100 ° C. for 2 minutes to form an 8 μm adhesive layer. While peeling off the lightly peeled PET separator (release film A) of the base film prepared in the process, the adhesive layer and the base resin layer are bonded together so that the base layer (base material 2) has an adhesive layer (first layer) on one side of the resin. A film having a structure in which 1 adhesive layer 3) was laminated was obtained.

  Further, similarly, an acrylic pressure-sensitive adhesive coating solution was applied to the release surface of a 25 μm-thick lightly peeled PET separator (release film D) having a silicone release treatment on one side, and the coating was performed at 100 ° C. for 2 minutes. The adhesive layer (second adhesive layer 4) and the base material (base material 2) were formed by drying to form an 8 μm adhesive layer, and peeling off the middle release PET separator (release film B) of the laminated film obtained in the previous step. ) Both sides of the structure sandwiched between the light release PET separator (release film D) and the heavy release PET separator (release film C) by pasting together so that the resin layers are combined and aging at room temperature for 7 days in this state An adhesive film 1 was obtained.

(Example 1 )
100 parts by weight of polyester polyol (Dainippon Ink Chemical Co., Ltd., trade name Vernock D-161) as solids and 100 parts by weight of polyisocyanate (Dainippon Ink Chemical Co., Ltd., trade name Vernock DN-950) as solids The base resin coating solution was prepared by diluting with a toluene / methyl ethyl ketone = 1/1 solution until the solid content was 40%. Other than using this coating solution, the same operation as in Reference Example 1 was performed, and the double-sided adhesive film was configured to be sandwiched between the light release PET separator (release film D) and the heavy release PET separator (release film C). 1 was obtained.

(Example 2 )
A polyurethane resin (trade name NIPPOLAN 5120 manufactured by Nippon Polyurethane Industry Co., Ltd.) was diluted with a toluene / ethyl acetate / isopropyl alcohol = 4/2/4 solution until the solid content became 20% to obtain a base resin coating solution. Other than using this coating solution, the same operation as in Reference Example 1 was performed, and the double-sided adhesive film was configured to be sandwiched between the light release PET separator (release film D) and the heavy release PET separator (release film C). 1 was obtained.

(Example 3 )
As an acrylic pressure-sensitive adhesive having reworkability, 100 parts by weight of SK Dyne 2137, manufactured by Soken Chemical Co., Ltd., and 0.5 parts by weight of coronate L45 as solids are prepared. Except for diluting to 12% to obtain an adhesive coating solution, the same operation as in Example 2 was performed, and sandwiched between a light release PET separator (release film D) and a heavy release PET separator (release film C). A double-sided pressure-sensitive adhesive film 1 having the above-described configuration was obtained.

(Example 4 )
The adhesive coating liquid to be laminated as the first adhesive layer 3 on one side of the base material 2 is the one having the reworkability of Example 3 , and the adhesive coating to be laminated as the second adhesive layer 4 on the opposite side of the base material 2 is applied. Except for using the strong adhesion type of Reference Example 1 as the working fluid, the same operation as in Example 2 was performed, and a lightly peeled PET separator (release film D) and a heavyly peeled PET separator (release film C) were used. A double-sided pressure-sensitive adhesive film 1 having a sandwiched structure was obtained. In this double-sided adhesive film 1, the adhesive force of the first adhesive layer 3 is different from the adhesive force of the second adhesive layer 4, and the adhesive force of the first adhesive layer 3 is the adhesive force of the second adhesive layer 4. It is getting smaller.

(Comparative Example 1)
The pressure-sensitive adhesive coating solution used in Reference Example 1 was applied to the release surface of a 50 μm-thick heavy release PET separator having a silicone release treatment on one side, dried at 100 ° C. for 3 minutes, and a 25 μm pressure-sensitive adhesive. A layer was formed and bonded so that the release surfaces of the 25 μm-thick lightly peeled PET separator were combined, and aging was performed for 7 days at room temperature in this state to obtain a substrateless double-sided adhesive film.

(Comparative Example 2)
The pressure-sensitive adhesive coating solution used in Reference Example 1 was applied to the release surface of a 50 μm-thick heavy release PET separator having a silicone release treatment on one side, dried at 100 ° C. for 2 minutes, and 8 μm pressure-sensitive adhesive. A layer was formed, and 9 μm-thick PET (trade name T4000 manufactured by Toyobo Co., Ltd.) was bonded as a core substrate. Furthermore, the same adhesive coating liquid was applied to the release surface of a 25 μm-thick lightly peeled PET separator, dried at 100 ° C. for 2 minutes to form an 8 μm adhesive layer, and the core of the laminated film obtained in the previous step A double-sided pressure-sensitive adhesive film having PET as a core substrate was obtained by pasting together so as to match the PET surface of the substrate and performing aging at room temperature for 7 days in this state.

(Comparative Example 3)
The pressure-sensitive adhesive coating liquid having reworkability used in Example 3 was applied to the release surface of a 50 μm-thick heavy release PET separator having a silicone release treatment on one side and dried at 100 ° C. for 3 minutes. A 25 μm thick adhesive layer is formed and bonded so that the release surfaces of 25 μm thick lightly peeled PET separators are combined, and in this state, aging is carried out at room temperature for 7 days, whereby a substrateless double-sided adhesive having reworkability A film was obtained.

(Comparative Example 4)
Except for using the pressure-sensitive adhesive coating solution used in Example 3 , the same operation as in Comparative Example 2 was performed to obtain a double-sided pressure-sensitive adhesive film having reworkability using PET as a core substrate.

About the obtained adhesive film, evaluation shown below was performed. The obtained results are shown in FIG.
1. Measurement of internal HAZE of adhesive layer Peel off the release films on both sides of each adhesive film of Reference Example 1, Examples 1 to 3 and Comparative Examples 1 to 4, and instead of a polycarbonate film of 70 μm thickness (Pure Ace: Teijin) A film having a sandwich structure was manufactured as a sample for optical measurement of the adhesive layer. Here, HAZE caused by Pure Ace is assumed to be negligibly small.
This sample was subjected to HA using a haze meter NDH2000 (Nippon Denshoku Industries Co., Ltd.).
ZE measurement was performed.

2. Evaluation of Orientation The sample for optical measurement was sandwiched between two polarizing plates and rotated to visually observe the disorder of polarization, and the presence or absence of the orientation of the adhesive film was confirmed. ○, where there was no polarization disturbance
The case where the polarization was disturbed was rated as x .

3. Measurement of film strength According to JIS K7127, the tensile strength of the double-sided adhesive film was measured with a tensile tester. The measurement was performed with the PET separators on both sides removed.

4. Measurement of contamination with adhesive The double-sided adhesive film was cut with a cutter, the cut surface of the double-sided adhesive film was rubbed against the PET film at an angle of 90 °, and the degree of the adhesive attached to the PET film was judged visually.
Almost no adhesion ・ ○ Adhesion of a considerable amount of adhesive is seen ・×

5. Evaluation of reworkability (part 1)
The second pressure-sensitive adhesive layer 4 side of the double-sided pressure-sensitive adhesive film was bonded to a 100 μm thick PET film and cut into a 25 mm wide strip. Next, after sticking the 1st adhesion layer 3 side to the glass plate and hold | maintaining at 23 degreeC for 1 day, the adhesive force was measured by peeling rate 300mm / min and 180 degree peeling. After peeling from the glass plate, an attempt was made to peel the double-sided adhesive film from the PET substrate.
Those having an adhesive strength of 5 N / 25 mm or more when peeled from the glass plate are x 5 N / 25 mm or less, and those that were able to peel the adhesive from the PET film are ○ 5 N / 25 mm or less, and the adhesive is removed from the PET film. For those that could not be peeled, △ was given.
(Part 2)
Adhering the second adhesive layer 4 side of the double-sided adhesive film to a 100 μm thick PET film 2
Trimmed to a strip with a width of 5 mm. Next, after sticking the 1st adhesion layer 3 side to an acrylic board and hold | maintaining at 23 degreeC for 1 day, the adhesive force was measured by the peeling rate of 300 mm / min and 180 degree peeling. Furthermore, it was visually confirmed whether the pressure-sensitive adhesive remained on the acrylic plate surface after peeling.
When the adhesive strength is 5N / 25mm or more when peeled off from the acrylic plate, when the adhesive remains on the acrylic plate, x, when the adhesive strength is 5N / 25mm or less and no adhesive remains on the acrylic plate, the result is ○. .

FIG. 1 is a schematic cross-sectional view of a double-sided pressure-sensitive adhesive film according to an embodiment of the present invention. FIG. 2 is a schematic view of a first step of the method for producing the double-sided pressure-sensitive adhesive film of FIG. 3A and 3B are schematic views of a second step of the method for producing the double-sided pressure-sensitive adhesive film of FIG. 4 (a) and 4 (b) are schematic views of a third step of the method for producing the double-sided pressure-sensitive adhesive film of FIG. FIG. 5 shows the evaluation of the pressure-sensitive adhesive films of Reference Example 1, Examples 1 to 3 and Comparative Examples 1 to 4.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Double-sided adhesive film 2 Base material 3 1st adhesion layer 4 2nd adhesion layer

Claims (4)

A base material made of optically non-oriented and transparent polyurethane resin, a transparent first adhesive layer provided on one surface of the base material, and a transparent material provided on the other surface of the base material And the thickness of the laminated three layers is 55 μm or less, and the thickness of the substrate is 3 μm.
A double-sided pressure-sensitive adhesive film having a thickness of ˜20 μm and an internal HAZE of 1% or less. The first pressure-sensitive adhesive layer is formed of an acrylic pressure-sensitive adhesive, and the first pressure-sensitive adhesive layer side is bonded to an acrylic plate and held at 23 ° C. for 1 day, and then peeled at 300 mm / min and pressure-sensitive at 180 ° peeling. 2. The double-sided pressure-sensitive adhesive film according to claim 1, wherein the force is 5 N / 25 mm or less, and the acrylic pressure-sensitive adhesive does not remain on the acrylic plate upon peeling. The double-sided pressure-sensitive adhesive film according to claim 1 or 2, wherein the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are acrylic and have a tensile strength of 5 MPa or more according to JIS K7127. The double-sided pressure-sensitive adhesive film according to claim 1 or 2, wherein the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are different.

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