WO2020110772A1

WO2020110772A1 - Adhesive film, foldable device, and rollable device

Info

Publication number: WO2020110772A1
Application number: PCT/JP2019/044831
Authority: WO
Inventors: 浩司設樂; 武史仲野
Original assignee: 日東電工株式会社
Priority date: 2018-11-28
Filing date: 2019-11-15
Publication date: 2020-06-04
Also published as: JP2024052821A; TW202031857A

Abstract

Provided is an adhesive film having excellent bendability and transparency. Also provided are a foldable device and a rollable device having excellent bendability.　This adhesive film has a substrate layer and an adhesive layer, tan δ(0.7%) at a strain of 0.7% of the adhesive film measured in the tension mode of a viscoelasticity measurement device being 0.1 or less. This adhesive film has a substrate layer and an adhesive layer, the difference (tan δ(0.7%) – tan δ(0.1%)) between tan δ(0.7%) at a strain of 0.7% and tan δ(0.1%) at a strain of 0.1% of the adhesive film measured in the tension mode of a viscoelasticity measurement device being 0.05 or less.

Description

Adhesive film, foldable device, and rollable device

The present invention relates to an adhesive film. The present invention also relates to a foldable device provided with such an adhesive film and a rollable device provided with such an adhesive film.

Adhesive films are used for reinforcement of various shaped members and surface protection.

For example, when an integrated circuit (IC) or a flexible printed circuit board (FPC) is bonded to a semiconductor element substrate (for example, a TFT substrate), thermocompression bonding is usually performed with an anisotropic conductive film (ACF). When such thermocompression bonding is performed, an adhesive film may be bonded and reinforced in advance on the back side of the substrate of the semiconductor element (for example, Patent Document 1).

In addition, as a method of manufacturing a flexible device or a rollable device that has been developed in recent years, generally, a peeling layer and a flexible or rollable film substrate are formed on a supporting substrate such as glass, and the film substrate Then, a TFT substrate is formed, and an organic EL layer is formed thereon. Then, the supporting substrate is peeled off to manufacture a flexible device or a rollable device. However, since the flexible display layer or the rollable display layer is very thin, the device may be defective due to handling or the like. Therefore, an adhesive film may be attached to the back side to reinforce (for example, Patent Document 2).

A semiconductor device substrate, flexible device, or rollable device may be repeatedly bent, and if the adhesive film attached to the back side of the substrate has poor bending properties, the recoverability after bending may deteriorate, and at worst, it may be repeated. It may break due to bending. Specifically, when an adhesive film is attached to a bent portion (for example, a movable bent portion of a folding member), the following problems occur, for example.

When the adhesive film is bent at an angle, a compressing force acts on the bent inner diameter side, so the adhesive film itself deforms in an attempt to alleviate the force. Specifically, for example, wrinkles easily occur.

When the adhesive film is bent at an angle, tensile stress acts on the bent outer diameter side. Therefore, when the stress is relieved, the floating from the adherend occurs.

If the pressure-sensitive adhesive film is bent at an angle, the thickness of the bendable part or the stretched part of the pressure-sensitive adhesive film will change greatly, and even in such a state, wrinkles are likely to occur and floating may occur. To do. For example, when the pressure-sensitive adhesive film is pulled, the thickness of the pressure-sensitive adhesive film is significantly reduced, and the adhesive film is apt to float from the adherend.

In this way, conventional pressure-sensitive adhesive films have not been able to achieve sufficient conformity to the corners and bends.

In particular, when an adhesive film is attached to the movable bending part, the bending is repeated, so that the adhesive film has a nick (so-called “habit”) on the movable bending part.

In addition, when an integrated circuit (IC) or a flexible printed circuit board (FPC) is bonded to a semiconductor element substrate (for example, a TFT substrate) by thermocompression bonding, the bonding position is confirmed from the back side of the substrate to perform pressure bonding. I do. Therefore, the pressure-sensitive adhesive film attached to the back side of the substrate is required to have transparency.

Japanese Patent No. 5600039 Japanese Patent No. 6376271

An object of the present invention is to provide an adhesive film having excellent flexibility and transparency. Another object of the present invention is to provide a foldable device and a rollable device having excellent flexibility.

The adhesive film of the present invention,
An adhesive film having a base material layer and an adhesive layer,
The tan δ (0.7%) at a strain of 0.7% measured in the tensile mode of the viscoelasticity measuring device is 0.1 or less.

The adhesive film of the present invention,
An adhesive film having a base material layer and an adhesive layer,
The difference between tan δ (0.7%) at a strain of 0.7% and tan δ (0.1%) at a strain of 0.1% measured in the tensile mode of the viscoelasticity measuring device (tan δ (0.7%)-tan δ (0.1%)) is 0.05 or less.

In one embodiment, the pressure-sensitive adhesive film of the present invention is bent at 6Φ and held at 90° C. for 48 hours, after which the bending is released and left at 23° C. and 50% RH for 24 hours. Has a bending angle of 60 to 180 degrees.

In one embodiment, the pressure-sensitive adhesive film of the present invention has a topcoat layer on the surface of the base material layer opposite to the surface having the pressure-sensitive adhesive layer.

In one embodiment, the top coat layer contains a binder containing at least one selected from polyester resins and urethane resins.

In one embodiment, the binder contains urethane resin.

In one embodiment, the top coat layer contains an antistatic component.

In one embodiment, the base material layer has a Young's modulus at 23° C. of 6.0×10 ⁷ Pa or more.

In one embodiment, the material of the base material layer is at least one selected from polyimide and polyether ether ketone.

In one embodiment, the pressure-sensitive adhesive film of the present invention has a topcoat layer on the surface of the base material layer opposite to the surface having the pressure-sensitive adhesive layer, and the topcoat layer contains a binder containing a urethane resin. And an antistatic component, and the material of the base material layer is at least one selected from polyimide and polyether ether ketone.

In one embodiment, the adhesive film of the present invention has a total light transmittance of 20% or more.

In one embodiment, the adhesive film of the present invention has a haze of 15% or less.

In one embodiment, the pressure-sensitive adhesive layer has an adhesive force of 1 N/25 mm or more with respect to a SUS plate at a pulling speed of 300 mm/min and a peel of 180 degrees at 23°C.

In one embodiment, the pressure-sensitive adhesive layer contains an acrylic pressure-sensitive adhesive.

In one embodiment, the adhesive film of the present invention is attached to a foldable member.

In one embodiment, the foldable member is an OLED.

In one embodiment, the adhesive film of the present invention is attached to a rollable member.

In one embodiment, the rollable member is an OLED.

The foldable device of the present invention includes the above-mentioned adhesive film.

The rollable device of the present invention includes the above adhesive film.

According to the present invention, an adhesive film having excellent flexibility and transparency can be provided. According to the present invention, it is also possible to provide a foldable device and a rollable device having excellent flexibility.

FIG. 1 is a schematic cross-sectional view showing one embodiment of the foldable device of the present invention, showing one usage mode of the adhesive film of the present invention. FIG. 2 is a schematic cross-sectional view illustrating a method for evaluating the bending recovery property. FIG. 3 is a schematic cross-sectional view illustrating an evaluation method for evaluation of peeling.

≪≪Adhesive film≫≫
The adhesive film of the present invention has a base material layer and an adhesive layer. That is, the pressure-sensitive adhesive film of the present invention may have any appropriate other layer as long as it has a base material layer and a pressure-sensitive adhesive layer, as long as the effects of the present invention are not impaired.

The base material layer may be one layer or two or more layers. The base material layer is preferably one layer from the viewpoint that the effect of the present invention can be further exhibited.

The pressure-sensitive adhesive layer may be one layer or two or more layers. The pressure-sensitive adhesive layer is preferably one layer from the viewpoint that the effect of the present invention can be further exhibited.

The pressure-sensitive adhesive film of the present invention may be provided with any suitable release liner on the surface of the pressure-sensitive adhesive layer on the side opposite to the base material layer for protection before use.

Examples of the release liner include a release liner in which the surface of a base material (liner base material) such as paper or plastic film is treated with silicone, or a surface of a base material (liner base material) such as paper or plastic film is formed of a polyolefin resin. Examples include laminated release liners. The plastic film as the liner substrate, for example, polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, Examples thereof include a polyurethane film and an ethylene-vinyl acetate copolymer film.

The thickness of the release liner is preferably 1 μm to 500 μm, more preferably 3 μm to 450 μm, further preferably 5 μm to 400 μm, and particularly preferably 10 μm to 300 μm.

The adhesive film of the present invention has a total thickness d of preferably 1 μm to 500 μm, more preferably 5 μm to 200 μm, further preferably 10 μm to 150 μm, particularly preferably 20 μm to 100 μm, and most preferably It is 30 μm to 80 μm. When the total thickness d of the adhesive film of the present invention is within the above range, the effect of the present invention can be more exhibited.

The adhesive film of the present invention has a tan δ (0.7%) at a strain of 0.7% measured in a tension mode of a viscoelasticity measuring device of 0.1 or less, preferably 0.09 or less, and more preferably Is 0.08 or less, more preferably 0.07 or less, and particularly preferably 0.06 or less. If the tan δ (0.7%) at a strain of 0.7% of the pressure-sensitive adhesive film of the present invention measured in a tension mode of a viscoelasticity measuring device is within the above range, the effect of the present invention can be more exhibited.

Tan δ (0.7%) at a strain of 0.7% measured in the tension mode of the viscoelasticity measuring device of the adhesive film is an index showing the loss tangent when the adhesive film is largely bent. Upon completion of the present invention, it was found based on various experimental data that the effect of the present invention can be more exhibited if this value is within the above range. The method for measuring tan δ (0.7%) at a strain of 0.7% measured in the tensile mode of the viscoelasticity measuring device will be described in detail later.

The adhesive film of the present invention has a tan δ (0.1%) at a strain of 0.1% measured in a tensile mode of a viscoelasticity measuring device of preferably 0.1 or less, more preferably 0.08 or less. , More preferably 0.06 or less, and particularly preferably 0.05 or less. If the tan δ (0.1%) at a strain of 0.1% measured in the tensile mode of the viscoelasticity measuring device of the pressure-sensitive adhesive film of the present invention is within the above range, the effect of the present invention can be more exhibited.

Tan δ (0.1%) at a strain of 0.1% measured in the tension mode of the viscoelasticity measuring device of the adhesive film is an index showing the loss tangent when the adhesive film is bent slightly. Upon completion of the present invention, it was found based on various experimental data that the effect of the present invention can be more exhibited if this value is within the above range. A method for measuring tan δ (0.1%) at a strain of 0.1% measured in the tensile mode of the viscoelasticity measuring device will be described in detail later.

The pressure-sensitive adhesive film of the present invention has a difference (tan δ (tan δ (0.1%) between a tan δ (0.7%) at a strain of 0.7% and a tan δ (0.1%) at a strain of 0.1% measured in a tensile mode of a viscoelasticity measuring device. 0.7%)-tan δ(0.1%)) is preferably 0.05 or less, more preferably 0.04 or less, still more preferably 0.03 or less. The difference (tan δ (tan δ (0.1%) between the tan δ (0.7%) at a strain of 0.7% and the tan δ (0.1%) at a strain of 0.7% of the pressure-sensitive adhesive film of the present invention measured in a tensile mode of a viscoelasticity measuring apparatus. If the ratio (0.7%)-tan δ(0.1%)) is within the above range, the effect of the present invention can be more exerted.

The difference (tan δ (0.7%) between tan δ (0.7%) at a strain of 0.7% and tan δ (0.1%) at a strain of 0.7%, which was measured in a tensile mode of a viscoelasticity measuring device, of the adhesive film. %)-Tan δ (0.1%)) is an index showing the difference between the loss tangent when the pressure-sensitive adhesive film is largely bent and the loss tangent when the pressure-sensitive adhesive film is slightly bent. Upon completion of the present invention, it was found based on various experimental data that the effect of the present invention can be more exhibited if this value is within the above range.

The pressure-sensitive adhesive film of the present invention is preferably bent at 6Φ and held at 90° C. for 48 hours, then released from the bending, and allowed to stand at 23° C. and 50% RH for 24 hours. It is 60 to 180 degrees, more preferably 80 to 180 degrees, further preferably 100 to 180 degrees, particularly preferably 120 to 180 degrees, and most preferably 150 to 180 degrees. is there. The bending angle of the pressure-sensitive adhesive film of the present invention after being bent at 6Φ and held at 90° C. for 48 hours, then released, and allowed to stand at 23° C. and 50% RH for 24 hours is within the above range. Within the range, the effect of the present invention can be more exerted.

The bending angle of the pressure-sensitive adhesive film after being bent at 6Φ and held at 90° C. for 48 hours, then released, and allowed to stand at 23° C. and 50% RH for 24 hours is the recoverability after bending. Is an index indicating. The method of measuring the bending angle after bending at 6Φ and holding at 90° C. for 48 hours, releasing the bending, and leaving at 23° C. and 50% RH for 24 hours will be described in detail later.

The adhesive film of the present invention has a total light transmittance of preferably 20% or more, more preferably 30% or more, further preferably 40% or more, particularly preferably 50% or more, most preferably Is 60% or more. When the total light transmittance of the pressure-sensitive adhesive film of the present invention is within the above range, excellent transparency can be further exhibited.

The adhesive film of the present invention has a haze of preferably 15% or less, more preferably 13% or less, further preferably 10% or less, particularly preferably 8% or less, and most preferably 6%. It is below. When the haze of the pressure-sensitive adhesive film of the present invention is within the above range, excellent transparency can be more exhibited.

Since the adhesive film of the present invention has excellent flexibility and transparency, it is preferably attached to a foldable member. Any appropriate member can be adopted as the foldable member as long as it can be repeatedly bent. Examples of such a foldable member include a foldable optical member, a foldable electronic member, and the like. Typically, a foldable OLED is used.

The pressure-sensitive adhesive film of the present invention is excellent in flexibility and transparency, and thus is preferably attached to a rollable member. Any appropriate member can be adopted as the rollable member as long as it can be repeatedly wound and unwound. Examples of such a rollable member include a rollable optical member and a rollable electronic member, and typically, a rollable OLED is used.

≪Base material layer≫
The thickness of the base material layer is preferably 1 μm to 500 μm, more preferably 5 μm to 300 μm, further preferably 10 μm to 100 μm, particularly preferably 15 μm to 80 μm, and most preferably 20 μm to 60 μm. .. When the thickness of the base material layer is within the above range, the effect of the present invention can be more exhibited.

The Young's modulus of the base material layer at 23° C. is preferably 6.0×10 ⁷ Pa or higher, more preferably 1.0×10 ⁸ Pa or higher, and further preferably 5.0×10 ⁸ Pa or higher. And particularly preferably 8.0×10 ⁸ Pa or higher, and most preferably 1.0×10 ⁹ Pa or higher. The upper limit of the Young's modulus of the base material layer at 23° C. is typically and preferably 1.0×10 ¹¹ Pa or less. When the Young's modulus at 23° C. of the base material layer is within the above range, the effect of the present invention can be more exhibited. If the Young's modulus of the base material layer at 23° C. is too low, if the adhesive film is bent at an angle, the tension on the outer diameter side may not be sufficiently retained against the compression on the inner diameter side, and the thickness may change. There is a possibility that it will be easy to float from the adherend. If the Young's modulus at 23° C. of the base material layer is too high, the pressure-sensitive adhesive film may not be easily deformed. The method of measuring Young's modulus will be described in detail later.

As the material of the base material layer, any appropriate material can be adopted as long as the effect of the present invention is not impaired. As a material of such a base material layer, a resin material is typically mentioned.

Examples of the resin material as the material of the base material layer include polyimide (PI), polyether ether ketone (PEEK), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polymethyl methacrylate. Acrylic resin such as (PMMA), polycarbonate, triacetyl cellulose (TAC), polysulfone, polyarylate, polyethylene (PE), polypropylene (PP), ethylene-propylene copolymer, ethylene-vinyl acetate copolymer (EVA) , Polyamide (nylon), wholly aromatic polyamide (aramid), polyvinyl chloride (PVC), polyvinyl acetate, polyphenylene sulfide (PPS), fluorine resin, cyclic olefin polymer, and the like.

The resin material as the material of the base material layer is preferably at least one selected from polyimide (PI), polyether ether ketone (PEEK), and cyclic olefin-based polymer from the viewpoint that the effect of the present invention can be further exhibited. And more preferably at least one selected from polyimide (PI) and polyether ether ketone (PEEK).

<<Adhesive layer>>
The thickness of the pressure-sensitive adhesive layer is preferably 1 μm to 500 μm, more preferably 5 μm to 300 μm, further preferably 10 μm to 100 μm, particularly preferably 15 μm to 80 μm, and most preferably 20 μm to 60 μm. .. When the thickness of the pressure-sensitive adhesive layer is within the above range, the effect of the present invention can be more exhibited.

The adhesive force of the pressure-sensitive adhesive layer to the glass plate at a pulling speed of 300 mm/min and a peel of 180 degrees at 23° C. is preferably 1 N/25 mm or more, more preferably 5 N/25 mm or more, and further preferably It is 10 N/25 mm or more, particularly preferably 12 N/25 mm or more, and most preferably 15 N/25 mm or more. The upper limit of the adhesive force of the pressure-sensitive adhesive layer to the glass plate at a tensile rate of 300 mm/min and 180 degree peeling at 23° C. is typically preferably 1000 N/25 mm or less, more preferably 5000 N/25 mm. Or less, more preferably 300 N/25 mm or less, particularly preferably 200 N/25 mm or less, and most preferably 100 N/25 mm or less. If the adhesive strength of the pressure-sensitive adhesive layer to the glass plate at a tensile rate of 300 mm/min at 180° peel at 23° C. is within the above range, the effect of the present invention can be further exhibited.

The adhesive layer contains a base polymer. The base polymer may be only one type, or may be two or more types. The content ratio of the base polymer in the pressure-sensitive adhesive layer is preferably 20% by weight to 100% by weight, more preferably 30% by weight to 95% by weight, from the viewpoint that the effect of the present invention can be further exhibited. It is preferably 40% by weight to 90% by weight, particularly preferably 45% by weight to 85% by weight, and most preferably 50% by weight to 80% by weight.

As the base polymer, any suitable polymer can be adopted as long as the effect of the present invention is not impaired. The base polymer is preferably at least one selected from acrylic polymers, rubber polymers, silicone polymers, and urethane polymers from the viewpoint that the effects of the present invention can be further exhibited. That is, the pressure-sensitive adhesive layer is preferably composed of an acrylic pressure-sensitive adhesive containing an acrylic polymer, a rubber-based pressure-sensitive adhesive containing a rubber-based polymer, a silicone-based pressure-sensitive adhesive containing a silicone-based polymer, and a urethane-based pressure-sensitive adhesive containing a urethane-based polymer. At least one selected is included. From the viewpoint that the effects of the present invention can be further exhibited, the pressure-sensitive adhesive layer preferably contains an acrylic pressure-sensitive adhesive. Hereinafter, an acrylic pressure-sensitive adhesive will be described in detail as a typical example of the pressure-sensitive adhesive that can be contained in the pressure-sensitive adhesive layer.

<Acrylic adhesive>
The acrylic pressure-sensitive adhesive contains an acrylic polymer as a base polymer. The acrylic adhesive may contain a tackifying resin. The acrylic pressure-sensitive adhesive may contain a crosslinking agent.

When the acrylic pressure-sensitive adhesive contains an acrylic polymer, a tackifying resin, and a crosslinking agent, the content ratio of the total amount of the acrylic polymer, the tackifying resin, and the crosslinking agent with respect to the total amount of the acrylic pressure-sensitive adhesive is From the viewpoint that the effect can be further exhibited, it is preferably 95% by weight or more, more preferably 97% by weight or more, and further preferably 99% by weight or more.

(Acrylic polymer)
As the acrylic polymer, for example, a polymer of a monomer component containing an alkyl (meth)acrylate as a main monomer and further containing a sub-monomer copolymerizable with the main monomer is preferable. Here, the main monomer means a component which accounts for more than 50% by weight of the whole monomer component.

As the alkyl (meth)acrylate, for example, a compound represented by the following formula (1) can be preferably used.
CH ₂ =C(R ¹ )COOR ² (1)

Here, R ¹ in the above formula (1) is a hydrogen atom or a methyl group, and R ² is a chain alkyl group having 1 to 20 carbon atoms (hereinafter, such a range of the number of carbon atoms is referred to as “C1- 20"). From the viewpoint of the storage elastic modulus of the pressure-sensitive adhesive layer, R ² is preferably a C1-14 chain alkyl group, more preferably a C2-10 chain alkyl group, and further preferably a C4-8 chain alkyl group. It is a chain alkyl group. Here, the term “chain” means a straight chain and a branched chain.

Examples of the alkyl(meth)acrylate in which R ² is a C1-20 chain alkyl group include, for example, methyl(meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, isopropyl(meth)acrylate, n-butyl. (Meth)acrylate, isobutyl(meth)acrylate, s-butyl(meth)acrylate, pentyl(meth)acrylate, isopentyl(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, lauryl (meth)acrylate, tridecyl (Meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, isostearyl (meth)acrylate, nonadecyl (meth)acrylate, eicosyl ( Examples thereof include (meth)acrylate. These alkyl (meth)acrylates may be only one kind or two or more kinds.

The alkyl (meth)acrylate is preferably n-butyl acrylate (BA) or 2-ethylhexyl acrylate (2EHA) from the viewpoint that the effect of the present invention can be further exhibited.

The content ratio of the alkyl (meth)acrylate in all the monomer components used for the synthesis of the acrylic polymer is preferably 70% by weight or more, more preferably 85% by weight, from the viewpoint that the effect of the present invention can be further exhibited. It is above, and more preferably 90% by weight or more. The upper limit of the content ratio of the alkyl (meth)acrylate is preferably 99.5% by weight or less, more preferably 99% by weight or less. However, the acrylic polymer may be obtained by polymerizing substantially only alkyl (meth)acrylate.

When R ² using the alkyl (meth) acrylate is a linear alkyl group of C4-8, alkyl R ² is a linear alkyl group of C4-8 among alkyl (meth) acrylates contained in the monomer components The ratio of (meth)acrylate is preferably 50% by weight or more, more preferably 70% by weight or more, further preferably 90% by weight or more, particularly from the viewpoint that the effect of the present invention can be further exhibited. It is preferably 95% by weight or more, and most preferably 99% by weight to 100% by weight.

As one embodiment of the acrylic polymer, an acrylic polymer in which 50% by weight or more of all monomer components is n-butyl acrylate (BA) can be mentioned. In this case, the content ratio of n-butyl acrylate (BA) in all the monomer components is preferably more than 50% by weight and 100% by weight or less, and more preferably 55% by weight, from the viewpoint that the effect of the present invention can be further exhibited. % To 95% by weight, more preferably 60 to 90% by weight, particularly preferably 63 to 85% by weight, most preferably 65 to 80% by weight. The total monomer component may further include 2-ethylhexyl acrylate (2EHA) in a proportion smaller than n-butyl acrylate (BA).

One embodiment of an acrylic polymer is an acrylic polymer in which less than 50% by weight of all monomer components is 2-ethylhexyl acrylate (2EHA). In this case, the content ratio of 2-ethylhexyl acrylate (2EHA) in all the monomer components is preferably more than 0% by weight and 48% by weight or less, more preferably 5% or more, from the viewpoint that the effect of the present invention can be further exhibited. % By weight to 45% by weight, more preferably 10% by weight to 43% by weight, particularly preferably 15% by weight to 40% by weight, most preferably 20% by weight to 35% by weight. The total monomer component may further contain n-butyl acrylate (BA) in a proportion higher than that of 2-ethylhexyl acrylate (2EHA).

Other monomers may be copolymerized with the acrylic polymer as long as the effects of the present invention are not impaired. Other monomers can be used for the purpose of adjusting the glass transition temperature (Tg) of the acrylic polymer, adjusting the adhesive performance, and the like. Examples of the monomer capable of improving the cohesive force and heat resistance of the pressure-sensitive adhesive include sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, cyano group-containing monomers, vinyl esters, aromatic vinyl compounds, and the like. Is preferred. Specific examples of vinyl esters include, for example, vinyl acetate (VAc), vinyl propionate, vinyl laurate and the like, with vinyl acetate (VAc) being preferred.

The “other monomer” may be only one kind or two or more kinds. The content of the other monomer in all the monomer components is preferably 0.001% by weight to 40% by weight, more preferably 0.01% by weight to 40% by weight, and further preferably 0.1% by weight to It is 10% by weight, particularly preferably 0.5% by weight to 5% by weight, and most preferably 1% by weight to 3% by weight.

As the other monomer that can introduce a functional group that can serve as a crosslinking group point into the acrylic polymer or contribute to the improvement of adhesive strength, for example, a hydroxyl group (OH group)-containing monomer, a carboxy group-containing monomer, an acid anhydride group-containing monomer, an amide Examples thereof include a group-containing monomer, an amino group-containing monomer, an imide group-containing monomer, an epoxy group-containing monomer, (meth)acryloylmorpholine and vinyl ethers.

As one embodiment of the acrylic polymer, there is an acrylic polymer in which a carboxy group-containing monomer is copolymerized as the other monomer. Examples of the carboxy group-containing monomer include acrylic acid (AA), methacrylic acid (MAA), carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid and isocrotonic acid. Is mentioned. Among these, acrylic acid (AA) and methacrylic acid (MAA) are preferable as the carboxy group-containing monomer, from the viewpoint that the effect of the present invention can be further expressed, and acrylic acid (AA) is more preferable. is there.

When a carboxy group-containing monomer is used as the other monomer, the content ratio of the other monomer in all the monomer components is preferably 0.1% by weight to 10% by weight from the viewpoint that the effect of the present invention can be further exhibited. More preferably 0.2% to 8% by weight, still more preferably 0.5% to 5% by weight, particularly preferably 0.7% to 4% by weight, most preferably 1% by weight. % To 3% by weight.

One example of an acrylic polymer is an acrylic polymer in which a hydroxyl group-containing monomer is copolymerized as another monomer. Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth). ) Hydroxyalkyl (meth)acrylates such as acrylates; polypropylene glycol mono(meth)acrylate; N-hydroxyethyl (meth)acrylamide; and the like. Among these, the hydroxyl group-containing monomer is preferably a hydroxyalkyl(meth)acrylate whose alkyl group is a linear chain having 2 to 4 carbon atoms, from the viewpoint of more exerting the effects of the present invention. Specific examples thereof include 2-hydroxyethyl acrylate (HEA) and 4-hydroxybutyl acrylate (4HBA), and 4-hydroxybutyl acrylate (4HBA) is more preferable.

When a hydroxyl group-containing monomer is used as the other monomer, the content ratio of the other monomer in all the monomer components is preferably 0.001% by weight to 10% by weight from the viewpoint that the effect of the present invention can be more exhibited. It is preferably 0.01% to 5% by weight, more preferably 0.02% to 2% by weight, particularly preferably 0.03% to 1% by weight, and most preferably 0.05. % By weight to 0.5% by weight.

The Tg of the base polymer can be, for example, −80° C. or higher in that the effect of the present invention can be further exhibited. The base polymer (preferably an acrylic polymer) is designed so that Tg is preferably −15° C. or lower from the viewpoint of enhancing the deformability of the pressure-sensitive adhesive layer in the shearing direction. In some embodiments, the Tg of the base polymer is, for example, preferably −25° C. or lower, more preferably −40° C. or lower, further preferably −50° C. or lower. The Tg of the base polymer is designed so that, for example, the Tg is preferably −70° C. or higher (more preferably −65° C. or higher, further preferably −60° C. or higher) from the viewpoint of enhancing cohesiveness and shape recovery. Has been done.

The Tg of the base polymer is based on the Tg of a homopolymer (homopolymer) of each monomer constituting the base polymer and the weight fraction (copolymerization ratio on a weight basis) of the monomer, and is calculated from the Fox equation. Refers to the required value. The Fox equation is a relational expression between Tg of a copolymer and the glass transition temperature Tgi of a homopolymer obtained by homopolymerizing each of the monomers constituting the copolymer, as shown below.
1/Tg=Σ(Wi/Tgi)

In the above Fox equation, Tg is the glass transition temperature (unit: K) of the copolymer, Wi is the weight fraction of the monomer i in the copolymer (copolymerization ratio on a weight basis), and Tgi is a homopolymer of the monomer i. Represents the glass transition temperature (unit: K) of. As the Tg of the homopolymer, the value described in publicly known data shall be adopted.

As the Tg of the homopolymer, for example, the following values can be specifically used.
2-Ethylhexyl acrylate-70℃
n-Butyl acrylate -55°C
Acrylic acid 106℃
2-hydroxyethyl acrylate -15℃
4-hydroxybutyl acrylate -40°C

Regarding the Tg of homopolymers other than those exemplified above, the values described in "Polymer Handbook" (3rd edition, John Wiley & Sons, Inc., 1989) can be used. If more than one numerical value is described in the above "Polymer Handbook", the value of "conventional" is adopted. For monomers not mentioned in the above "Polymer Handbook", the catalog values of the monomer manufacturing companies shall be adopted. As the Tg of the homopolymer of the monomer, which is not described in the above "Polymer Handbook" and the catalog value of the monomer manufacturing company is not provided, the value obtained by the measuring method described in JP2007-51271A is used. To do.

As a method for obtaining an acrylic polymer, for example, a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, a suspension polymerization method, or the like, various polymerization methods known as a synthetic method of an acrylic polymer may be appropriately adopted. You can Among these polymerization methods, the solution polymerization method can be preferably used. As a method of supplying a monomer when carrying out the solution polymerization, a batch charging method of supplying all of the monomer components at once, a continuous supply (dropping) method, a divided supply (dropping) method and the like can be appropriately adopted. The polymerization temperature can be appropriately selected according to the type of monomer and solvent used, the type of polymerization initiator, etc., and is preferably 20° C. or higher, more preferably 30° C. or higher, and further preferably 40° C. Or higher, preferably 170° C. or lower, more preferably 160° C. or lower, still more preferably 140° C. or lower. As a method for obtaining an acrylic polymer, photopolymerization (typically carried out in the presence of a photopolymerization initiator) performed by irradiating light such as UV, or irradiation with radiation such as β ray or γ ray is performed. Alternatively, active energy ray irradiation polymerization such as radiation polymerization may be employed.

The solvent (polymerization solvent) used for solution polymerization can be appropriately selected from any appropriate organic solvent. Examples thereof include aromatic compounds such as toluene (typically aromatic hydrocarbons), acetic acid esters such as ethyl acetate, and aliphatic or alicyclic hydrocarbons such as hexane and cyclohexane.

The initiator used for polymerization (polymerization initiator) can be appropriately selected from any appropriate polymerization initiator according to the type of polymerization method. Only 1 type may be sufficient as a polymerization initiator and 2 or more types may be sufficient as it. Examples of such a polymerization initiator include azo polymerization initiators such as 2,2′-azobisisobutyronitrile (AIBN); persulfates such as potassium persulfate; benzoyl peroxide, hydrogen peroxide, etc. Peroxide-based initiators; substituted ethane-based initiators such as phenyl-substituted ethane; aromatic carbonyl compounds; and the like. As another example of the polymerization initiator, a redox type initiator obtained by combining a peroxide and a reducing agent can be mentioned.

The amount of the polymerization initiator used is preferably 0.005 to 1 part by weight, and more preferably 0.01 to 1 part by weight, based on 100 parts by weight of all the monomer components.

The Mw of the acrylic polymer is preferably 10×10 ⁴ to 500×10 ⁴ , more preferably 10×10 ⁴ to 150×10 ⁴ , and further preferably 20×10 ⁴ to 75×10 ⁴ . And particularly preferably 35×10 ⁴ to 65×10 ⁴ . Here, Mw refers to a standard polystyrene conversion value obtained by GPC (gel permeation chromatography). As the GPC device, for example, a model name “HLC-8320GPC” (column: TSKgel GMH-H(S), manufactured by Tosoh Corporation) can be used.

(Tackifying resin)
The acrylic pressure-sensitive adhesive may contain a tackifying resin from the viewpoint that the effect of the present invention can be further exhibited. Examples of the tackifying resin include rosin-based tackifying resin, terpene-based tackifying resin, hydrocarbon-based tackifying resin, epoxy-based tackifying resin, polyamide-based tackifying resin, elastomer-based tackifying resin, and phenol-based tackifying resin. , Ketone-based tackifying resins, and the like. The tackifying resin may be only one kind or two or more kinds.

The amount of the tackifying resin used is preferably 5 parts by weight to 70 parts by weight, more preferably 10 parts by weight to 60 parts by weight, based on 100 parts by weight of the base polymer, from the viewpoint that the effect of the present invention can be further exhibited. Parts, more preferably 15 parts by weight to 50 parts by weight, further preferably 20 parts by weight to 45 parts by weight, particularly preferably 25 parts by weight to 40 parts by weight, most preferably 25 parts by weight to 35 parts by weight.

The tackifying resin preferably contains a tackifying resin TL having a softening point of less than 105° C. from the viewpoint that the effect of the present invention can be further exhibited. The tackifying resin TL can effectively contribute to improving the deformability of the pressure-sensitive adhesive layer in the surface direction (shear direction). From the viewpoint of obtaining a higher effect of improving the deformability, the softening point of the tackifying resin used as the tackifying resin TL is preferably 50° C. to 103° C., more preferably 60° C. to 100° C., and further preferably The temperature is from 65°C to 95°C, particularly preferably from 70°C to 90°C, and most preferably from 75°C to 85°C.

The softening point of the tackifying resin is defined as the value measured based on the softening point test method (ring and ball method) specified in JIS K5902 and JIS K2207. Specifically, the sample should be melted as quickly as possible and the ring placed on a flat metal plate should be carefully filled to prevent bubbles. After cooling down, cut off the raised part from the plane including the upper end of the ring with a slightly heated knife. Next, a support (ring holder) is placed in a glass container (heating bath) having a diameter of 85 mm or more and a height of 127 mm or more, and glycerin is poured until the depth becomes 90 mm or more. Next, a steel ball (diameter: 9.5 mm, weight: 3.5 g) and a ring filled with a sample are immersed in glycerin so that they do not contact each other, and the temperature of glycerin is kept at 20°C plus or minus 5°C for 15 minutes. .. Next, a steel ball is placed on the center of the surface of the sample in the ring, and this is placed in a fixed position on the support. Next, keeping the distance from the upper end of the ring to the glycerin surface at 50 mm, placing a thermometer, setting the position of the center of the mercury ball of the thermometer to the same height as the center of the ring, and heating the container. The Bunsen burner flame used for heating is placed so as to hit the center of the bottom of the container and the edge thereof so that the heating is even. The rate at which the bath temperature rises after reaching 40° C. after the start of heating must be 5.0 plus or minus 0.5° C. per minute. The temperature at which the sample gradually softens and flows down from the ring and finally comes into contact with the bottom plate is read, and this is taken as the softening point. Two or more softening points are measured at the same time, and the average value is adopted.

The amount of the tackifying resin TL to be used is preferably 5 parts by weight to 50 parts by weight, more preferably 10 parts by weight to 100 parts by weight of the base polymer, from the viewpoint that the effect of the present invention can be further exhibited. The amount is 45 parts by weight, more preferably 15 parts by weight to 40 parts by weight, particularly preferably 20 parts by weight to 35 parts by weight, and most preferably 25 parts by weight to 32 parts by weight.

As the tackifying resin TL, one or two or more kinds of the tackifying resins exemplified above may be appropriately selected from those having a softening point of less than 105°C. The tackifying resin TL preferably contains a rosin resin.

Rosin resins that can be preferably used as the tackifying resin TL include rosin esters such as unmodified rosin ester and modified rosin ester. Examples of the modified rosin ester include hydrogenated rosin ester.

The tackifying resin TL preferably contains a hydrogenated rosin ester from the viewpoint that the effect of the present invention can be further exhibited. The hydrogenated rosin ester has a softening point of preferably less than 105° C., more preferably 50° C. to 100° C., still more preferably 60° C. to 90° C., from the viewpoint that the effect of the present invention can be further exhibited. And particularly preferably 70° C. to 85° C., and most preferably 75° C. to 85° C.

The tackifying resin TL may contain a non-hydrogenated rosin ester. Here, the non-hydrogenated rosin ester is a concept that comprehensively refers to the above-mentioned rosin esters other than the hydrogenated rosin ester. Examples of the non-hydrogenated rosin ester include unmodified rosin ester, disproportionated rosin ester, and polymerized rosin ester.

The non-hydrogenated rosin ester has a softening point of preferably less than 105° C., more preferably 50° C. to 100° C., still more preferably 60° C. to 90, from the viewpoint that the effect of the present invention can be further exhibited. C., particularly preferably 70 to 85.degree. C., most preferably 75 to 85.degree.

The tackifying resin TL may contain another tackifying resin in addition to the rosin-based resin. As the other tackifying resin, among the tackifying resins exemplified above, one kind or two or more kinds appropriately selected from those having a softening point of less than 105° C. can be adopted. The tackifying resin TL may include, for example, a rosin resin and a terpene resin.

The content ratio of the rosin-based resin in the entire tackifying resin TL is preferably more than 50% by weight, more preferably 55% by weight to 100% by weight, and further preferably, from the viewpoint that the effect of the present invention can be further exhibited. Is 60% to 99% by weight, particularly preferably 65% to 97% by weight, most preferably 75% to 97% by weight.

The tackifying resin may include the tackifying resin TL in combination with the tackifying resin TH having a softening point of 105° C. or higher (preferably 105° C. to 170° C.), in that the effect of the present invention can be further exhibited. Good.

As the tackifying resin TH, one kind or two or more kinds of the tackifying resins exemplified above, which are appropriately selected from those having a softening point of 105° C. or higher, can be adopted. The tackifying resin TH may include at least one selected from rosin-based tackifying resins (for example, rosin esters) and terpene-based tackifying resins (for example, terpene phenolic resins).

(Crosslinking agent)
The acrylic pressure-sensitive adhesive may contain a crosslinking agent. The cross-linking agent may be only one kind or two or more kinds. By using the crosslinking agent, it is possible to impart an appropriate cohesive force to the acrylic pressure-sensitive adhesive. The cross-linking agent can also help control the displacement and return distances in the retention test. The acrylic pressure-sensitive adhesive containing a crosslinking agent can be obtained, for example, by forming a pressure-sensitive adhesive layer using a pressure-sensitive adhesive composition containing the crosslinking agent. The cross-linking agent may be included in the acrylic pressure-sensitive adhesive in a form after the cross-linking reaction, a form before the cross-linking reaction, a form in which the cross-linking reaction has occurred, an intermediate or complex form of these, and the like. The cross-linking agent is typically contained in the acrylic pressure-sensitive adhesive exclusively in the form after the cross-linking reaction.

The amount of the cross-linking agent used is preferably 0.005 to 10 parts by weight, more preferably 0.01 part by weight, based on 100 parts by weight of the base polymer, from the viewpoint that the effect of the present invention can be further exhibited. To 7 parts by weight, more preferably 0.05 to 5 parts by weight, particularly preferably 0.1 to 4 parts by weight, and most preferably 1 to 3 parts by weight.

Examples of the cross-linking agent include isocyanate cross-linking agents, epoxy cross-linking agents, silicone cross-linking agents, oxazoline cross-linking agents, aziridine cross-linking agents, silane cross-linking agents, alkyl etherified melamine cross-linking agents, and metal chelate cross-linking agents. , A crosslinking agent such as peroxide, and the like, from the viewpoint that the effect of the present invention can be more exhibited, an isocyanate crosslinking agent and an epoxy crosslinking agent are preferable, and an isocyanate crosslinking agent is more preferable. ..

As the isocyanate-based cross-linking agent, a compound having two or more isocyanate groups (including an isocyanate-regenerated functional group in which the isocyanate group is temporarily protected by a blocking agent or quantification) can be used. Examples of the isocyanate-based cross-linking agent include aromatic isocyanates such as tolylene diisocyanate and xylene diisocyanate; alicyclic isocyanates such as isophorone diisocyanate; aliphatic isocyanates such as hexamethylene diisocyanate.

Specific examples of the isocyanate cross-linking agent include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate; alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate and isophorone diisocyanate; 2 Aromatic diisocyanates such as 4,4-tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, xylylene diisocyanate, and polymethylene polyphenyl isocyanate; trimethylolpropane/tolylene diisocyanate trimer adducts (for example, manufactured by Tosoh Corporation, Trade name Coronate L), trimethylolpropane/hexamethylene diisocyanate trimer adduct (for example, Tosoh Corporation, trade name: Coronate HL), hexamethylene diisocyanate isocyanurate (for example, Tosoh Corporation, trade name: Coronate) HX) and other isocyanate adducts; trimethylolpropane adduct of xylylene diisocyanate (for example, Mitsui Chemicals, Inc., trade name: Takenate D110N), trimethylolpropane adduct of xylylene diisocyanate (for example, Mitsui Chemicals, product Name: Takenate D120N), trimethylolpropane adduct of isophorone diisocyanate (for example, Mitsui Chemicals, trade name: Takenate D140N), hexamethylene diisocyanate trimethylolpropane adduct (for example, Mitsui Chemicals, trade name: Takenate) D160N); polyether polyisocyanates, polyester polyisocyanates, and adducts of these with various polyols; polyisocyanates polyfunctionalized with isocyanurate bonds, burette bonds, allophanate bonds and the like; Among these, aromatic isocyanates and alicyclic isocyanates are preferable in terms of achieving good balance between deformability and cohesive force.

The amount of the isocyanate cross-linking agent used is preferably 0.005 to 10 parts by weight, and more preferably 0.01 to 100 parts by weight of the base polymer, from the viewpoint that the effect of the present invention can be further exhibited. Parts by weight to 7 parts by weight, more preferably 0.05 parts by weight to 5 parts by weight, particularly preferably 0.1 parts by weight to 4 parts by weight, most preferably 1 part by weight to 3 parts by weight. is there.

When the monomer component constituting the acrylic polymer contains a hydroxyl group-containing monomer, the weight ratio of isocyanate crosslinking agent/hydroxyl group-containing monomer is preferably more than 20 and less than 50 from the viewpoint that the effect of the present invention can be further exhibited. Yes, more preferably 22 to 45, further preferably 25 to 40, particularly preferably 27 to 40, and most preferably 30 to 35.

When the acrylic pressure-sensitive adhesive contains the tackifying resin TL having a softening point of 105° C. or lower, the weight ratio of the tackifying resin TL/isocyanate cross-linking agent is preferably more than 2 from the viewpoint that the effect of the present invention can be further exhibited. Is less than 15, more preferably 5 to 13, still more preferably 7 to 12, and particularly preferably 7 to 11.

As the epoxy-based cross-linking agent, a polyfunctional epoxy compound having two or more epoxy groups in one molecule can be used. Examples of the epoxy crosslinking agent include N,N,N′,N′-tetraglycidyl-m-xylenediamine, diglycidylaniline, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, 1, 6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, sorbitol polyglycidyl ether, glycerol polyglycidyl ether, penta Erythritol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitan polyglycidyl ether, trimethylolpropane polyglycidyl ether, adipic acid diglycidyl ester, o-phthalic acid diglycidyl ester, triglycidyl-tris(2-hydroxyethyl) isocyanurate, Examples thereof include resorcin diglycidyl ether, bisphenol-S-diglycidyl ether, and epoxy resins having two or more epoxy groups in the molecule. Examples of commercially available products of the epoxy-based cross-linking agent include trade names “Tetrad C” and “Tetrad X” manufactured by Mitsubishi Gas Chemical Company.

The amount of the epoxy-based cross-linking agent used is preferably 0.005 to 10 parts by weight, more preferably 0.01 to 100 parts by weight of the base polymer, from the viewpoint that the effect of the present invention can be further exhibited. Parts by weight to 5 parts by weight, more preferably 0.015 parts by weight to 1 part by weight, particularly preferably 0.15 parts by weight to 0.5 parts by weight, most preferably 0.015 parts by weight to 0.3 parts by weight.

(Other ingredients)
Acrylic pressure-sensitive adhesives, if necessary, such as leveling agents, crosslinking aids, plasticizers, softeners, fillers, antistatic agents, antiaging agents, ultraviolet absorbers, antioxidants, light stabilizers, etc. Various additives generally used in the field of agents may be contained. As such various additives, conventionally known ones can be used by a conventional method.

<< Antistatic layer >>
The pressure-sensitive adhesive film of the present invention may have an antistatic layer on the surface of the base material layer opposite to the surface having the pressure-sensitive adhesive layer. The pressure-sensitive adhesive film of the present invention has an antistatic layer on the surface opposite to the surface having the pressure-sensitive adhesive layer of the substrate layer, whereby the charge of the pressure-sensitive adhesive film itself can be suppressed, and dust becomes difficult to be adsorbed, which is preferable. It becomes a mode.

As the antistatic layer, for example, a method of applying an antistatic resin composed of an antistatic agent and a resin component, a conductive polymer, a method of applying a conductive resin containing a conductive substance, or a method of depositing or plating a conductive substance is available. Can be mentioned.

Examples of the antistatic agent contained in the antistatic resin include cation type antistatic agents having a cationic functional group such as quaternary ammonium salt, pyridinium salt, primary, secondary and tertiary amino groups; Anionic antistatic agents having anionic functional groups such as sulfonates, sulfates, phosphonates, and phosphates; amphoteric charges such as alkylbetaine and its derivatives, imidazoline and its derivatives, alanine and its derivatives Antistatic agent; nonionic antistatic agent such as amino alcohol and its derivative, glycerin and its derivative, polyethylene glycol and its derivative, etc.; polymerization or copolymerization of the above-mentioned cation type, anion type and amphoteric ion type monomer having an ion conductive group. And the like. These antistatic agents may be used alone or in combination of two or more.

The cationic antistatic agent has, for example, a quaternary ammonium group such as an alkyltrimethylammonium salt, an acyloylamidopropyltrimethylammonium methosulfate, an alkylbenzylmethylammonium salt, an acylcholine chloride, and polydimethylaminoethylmethacrylate (meth). ) Acrylate copolymers; styrene copolymers having quaternary ammonium groups such as polyvinylbenzyltrimethylammonium chloride; diallylamine copolymers having quaternary ammonium groups such as polydiallyldimethylammonium chloride; These antistatic agents may be used alone or in combination of two or more.

Examples of the anionic antistatic agent include alkyl sulfonates, alkyl benzene sulfonates, alkyl sulfate ester salts, alkyl ethoxy sulfate ester salts, alkyl phosphate ester salts, and sulfonic acid group-containing styrene copolymers. .. These antistatic agents may be used alone or in combination of two or more.

Examples of zwitterionic antistatic agents include alkyl betaines, alkyl imidazolium betaines, and carbobetaine graft copolymers. These antistatic agents may be used alone or in combination of two or more.

Examples of the nonionic antistatic agent include fatty acid alkylolamide, di(2-hydroxyethyl)alkylamine, polyoxyethylenealkylamine, fatty acid glycerin ester, polyoxyethylene glycol fatty acid ester, sorbitan fatty acid ester, polyoxysorbitan. Examples thereof include fatty acid ester, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ether, polyethylene glycol, polyoxyethylene diamine, a copolymer of polyether, polyester and polyamide, and methoxy polyethylene glycol (meth)acrylate. These antistatic agents may be used alone or in combination of two or more.

Examples of conductive polymers include polyaniline, polypyrrole, polythiophene, and the like. These conductive polymers may be used alone or in combination of two or more.

As the conductive substance, for example, tin oxide, antimony oxide, indium oxide, cadmium oxide, titanium oxide, zinc oxide, indium, tin, antimony, gold, silver, copper, aluminum, nickel, chromium, titanium, iron, cobalt, Copper iodide and alloys or mixtures thereof and the like can be mentioned. Only one kind of these conductive materials may be used, or two or more kinds thereof may be used.

As the resin component used for the antistatic resin and the conductive resin, for example, general-purpose resins such as polyester resin, acrylic resin, polyvinyl resin, urethane resin, melamine resin, and epoxy resin are used. Incidentally, in the case of the polymer type antistatic agent, the resin component may not be contained. Further, as a cross-linking agent, a methylol- or alkylol-based melamine compound, urea compound, glyoxal compound, acrylamide compound, epoxy compound, isocyanate compound, etc. may be contained as a component of the antistatic resin. Is.

As a method for forming the antistatic layer, for example, the above-mentioned antistatic resin, conductive polymer, conductive resin or the like is diluted with a solvent such as an organic solvent or water, and the coating liquid is applied to a substrate or the like and dried. It is formed by doing.

Examples of the diluted solution used for forming the antistatic layer include methyl ethyl ketone, acetone, ethyl acetate, tetrahydrofuran, dioxane, cyclohexanone, n-hexane, toluene, xylene, methanol, ethanol, n-propanol, isopropanol, water and the like. .. Only one kind of these solvents may be used, or two or more kinds thereof may be used.

Regarding the coating method for forming the antistatic layer, any suitable coating method is appropriately used. Examples of such a coating method include roll coating, gravure coating, reverse coating, roll brushing, spray coating, air knife coating, impregnation and curtain coating.

Any appropriate method is appropriately used as the method for vapor deposition or plating of the conductive material. Examples of such a method include vacuum vapor deposition, sputtering, ion plating, chemical vapor deposition, spray pyrolysis, chemical plating, electroplating and the like.

The thickness of the antistatic layer may be any appropriate thickness as long as the effect of the present invention is not impaired. The thickness of the antistatic layer is preferably 0.001 μm to 5 μm, and more preferably 0.005 μm to 1 μm, from the viewpoint that the effect of the present invention can be further exhibited.

≪Top coat layer≫
The pressure-sensitive adhesive film of the present invention may have a topcoat layer on the surface of the base material layer opposite to the surface having the pressure-sensitive adhesive layer. The top coat layer preferably contains a binder, and more preferably contains a binder and a slip agent. When the pressure-sensitive adhesive film of the present invention has the top coat layer, the scratch resistance of the pressure-sensitive adhesive film is improved, which is a preferred embodiment.

<Binder>
As the binder, any suitable resin can be adopted as long as the effect of the present invention is not impaired. Such a resin is preferably at least one selected from the group consisting of a polyester resin and a urethane resin, from the viewpoint that the effect of the present invention can be further exhibited.

(Polyester resin)
When the binder contains a polyester resin, the polyester resin may be only one kind or two or more kinds.

The polyester resin is preferably a resin containing polyester as a main component. The content of polyester in the polyester resin is preferably more than 50% by weight, more preferably 75% by weight or more, and further preferably 90% by weight or more.

The polyester is preferably selected from polyvalent carboxylic acids having two or more carboxyl groups in one molecule (preferably dicarboxylic acids) and derivatives thereof (anhydrides, esterified products, halides, etc. of polycarboxylic acid). At least one compound (polyvalent carboxylic acid component) and at least one compound selected from polyhydric alcohols (preferably diols) having two or more hydroxyl groups in one molecule (polyvalent) Alcohol component) and condensed structure.

Examples of the compound that can be adopted as the polycarboxylic acid component include oxalic acid, malonic acid, difluoromalonic acid, alkylmalonic acid, succinic acid, tetrafluorosuccinic acid, alkylsuccinic acid, (±)-malic acid, meso- Tartaric acid, itaconic acid, maleic acid, methylmaleic acid, fumaric acid, methylfumaric acid, acetylenedicarboxylic acid, glutaric acid, hexafluoroglutaric acid, methylglutaric acid, glutaconic acid, adipic acid, dithioadipic acid, methyladipic acid, dimethyladipine Acid, tetramethyladipic acid, methyleneadipic acid, muconic acid, galactaric acid, pimelic acid, suberic acid, perfluorosuberic acid, 3,3,6,6-tetramethylsuberic acid, azelaic acid, sebacic acid, perfluorosebacine Aliphatic dicarboxylic acids such as acids, brassylic acid, dodecyldicarboxylic acid, tridecyldicarboxylic acid, and tetradecyldicarboxylic acid; cycloalkyldicarboxylic acids (eg, 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid), 1 Alicyclic dicarboxylic acids such as 4-(2-norbornene)dicarboxylic acid, 5-norbornene-2,3-dicarboxylic acid (hymic acid), adamantanedicarboxylic acid, spiroheptanedicarboxylic acid; phthalic acid, isophthalic acid, dithioisophthalic acid Acid, methylisophthalic acid, dimethylisophthalic acid, chloroisophthalic acid, dichloroisophthalic acid, terephthalic acid, methylterephthalic acid, dimethylterephthalic acid, chloroterephthalic acid, bromoterephthalic acid, naphthalenedicarboxylic acid, oxofluorangecarboxylic acid, anthracenedicarboxylic acid, Biphenyldicarboxylic acid, biphenylenedicarboxylic acid, dimethylbiphenylenedicarboxylic acid, 4,4"-p-terephenylenedicarboxylic acid, 4,4"-p-quarrelphenyldicarboxylic acid, bibenzyldicarboxylic acid, azobenzenedicarboxylic acid, homophthalic acid, Phenylenediacetic acid, phenylenedipropionic acid, naphthalenedicarboxylic acid, naphthalenedipropionic acid, biphenyldiacetic acid, biphenyldipropionic acid, 3,3'-[4,4'-(methylenedi-p-biphenylene)dipropionic acid, 4 ,4'-bibenzyldiacetic acid, 3,3'(4,4'-bibenzyl)dipropionic acid, oxydi-p-phenylenediacetic acid and other aromatic dicarboxylic acids; acid anhydride of any of the above-mentioned polycarboxylic acids A polycarboxylic acid of any of the above. Examples thereof include steers (eg, alkyl esters, monoesters, diesters, etc.); acid halides (eg, dicarboxylic acid chlorides, etc.) corresponding to any of the polyvalent carboxylic acids described above, and the like.

Preferred examples of the compound that can be used as the polycarboxylic acid component include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid and acid anhydrides thereof; adipic acid, sebacic acid, azelaic acid, succinic acid, and fumaric acid. Aliphatic dicarboxylic acids such as acids, maleic acid, hymic acid, and 1,4-cyclohexanedicarboxylic acid, and acid anhydrides thereof; lower alkyl esters of the above dicarboxylic acids (for example, esters with monoalcohols having 1 to 3 carbon atoms) ; And the like.

Examples of compounds that can be used as the polyhydric alcohol component include ethylene glycol, propylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl. Glycol, 1,5-pentanediol, 1,6-hexanediol, 3-methylpentanediol, diethylene glycol, 1,4-cyclohexanedimethanol, 3-methyl-1,5-pentanediol, 2-methyl-1,3 -Propane diol, 2,2-diethyl-1,3-propane diol, 2-butyl-2-ethyl-1,3-propane diol, xylylene glycol, hydrogenated bisphenol A, bisphenol A, and other diols. .. Other examples include alkylene oxide adducts of these compounds (eg, ethylene oxide adducts, propylene oxide adducts, etc.).

The polyester resin preferably contains a water-dispersible polyester, and more preferably contains a water-dispersible polyester as a main component. Such a water-dispersible polyester has, for example, a hydrophilic functional group (for example, at least one selected from hydrophilic functional groups such as metal sulfonate group, carboxyl group, ether group and phosphoric acid group) introduced into the polymer. It may be a polyester having improved water dispersibility. As described above, as a method of introducing a hydrophilic functional group into the polymer, for example, a method of copolymerizing a compound having a hydrophilic functional group, polyester or a precursor thereof (for example, polyvalent carboxylic acid component, polyhydric alcohol) Any appropriate technique such as a method of modifying components, oligomers thereof, etc.) to generate a hydrophilic functional group can be appropriately adopted. Preferred water-dispersible polyesters include polyesters (copolymerized polyesters) obtained by copolymerizing a compound having a hydrophilic functional group.

The polyester resin used as the binder may be one having a saturated polyester as a main component or one having an unsaturated polyester as a main component. The polyester resin is preferably a saturated polyester as a main component, and more preferably a saturated polyester imparted with water dispersibility (for example, saturated copolyester). Such polyester resin (polyester resin which may be prepared in the form of an aqueous dispersion) can be synthesized by any appropriate method, or a commercially available product can be easily obtained.

The molecular weight of the polyester resin is preferably 0.5×10 ⁴ to 15×10 ⁴ , more preferably 1 as the weight average molecular weight (Mw) in terms of standard polystyrene measured by gel permeation chromatography (GPC). It is from ×10 ⁴ to 6×10 ⁴ .

The glass transition temperature (Tg) of the polyester resin is preferably 0°C to 100°C, more preferably 10°C to 80°C.

(Urethane resin)
When a urethane-based resin is contained in the binder, the urethane-based resin may be only one type or two or more types.

The urethane resin is preferably a urethane resin obtained by curing a composition containing a polyol (A) and a polyfunctional isocyanate compound (B).

As the polyol (A), only one kind may be used, or two or more kinds may be used.

As the polyol (A), any appropriate polyol can be adopted as long as it is a polyol having two or more OH groups. Examples of such a polyol (A) include a polyol (diol) having two OH groups, a polyol (triol) having three OH groups, a polyol (tetraol) having four OH groups, and an OH group of 5 Examples thereof include a polyol having one (pentaol) and a polyol having six OH groups (hexaol).

As the polyol (A), preferably, glycols such as ethylene glycol and propylene glycol having two or more OH groups are adopted as an essential component. By adopting glycol as an essential component in this way, it is possible to provide a urethane-based cured resin having excellent strength of a coating film after curing, excellent adhesion to a substrate and excellent retention of an added substance. The content ratio of glycol in the polyol (A) is preferably 30% by weight to 100% by weight, more preferably 50% by weight to 100% by weight, and further preferably 70% by weight to 100% by weight. %, more preferably 90% to 100% by weight, particularly preferably 95% to 100% by weight, most preferably substantially 100% by weight.

Examples of the polyol (A) include ethylene glycol, diethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2-butyl- 2-ethyl-1,3-propanediol, 2,4-diethyl-1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonane Diol, 2-methyl-1,8-octanediol, 1,8-decanediol, octadecanediol, glycerin, trimethylolpropane, pentaerythritol, hexanetriol, polyethylene glycol, polypropylene glycol, polyester polyol, polyether polyol, polycaprolactone Examples include polyols, polycarbonate polyols, castor oil-based polyols, and the like.

The polyester polyol can be obtained, for example, by an esterification reaction between a polyol component and an acid component.

Examples of the acid component include succinic acid, methylsuccinic acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, 1,12-dodecanedioic acid, 1,14-tetradecanedioic acid, dimer acid, 2-methyl-1, 4-cyclohexanedicarboxylic acid, 2-ethyl-1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, isophthalic acid, terephthalic acid, 1,4-naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid , And acid anhydrides thereof.

As the polyether polyol, for example, water, low molecular weight polyol (propylene glycol, ethylene glycol, glycerin, trimethylolpropane, pentaerythritol, etc.), bisphenols (bisphenol A, etc.), dihydroxybenzene (catechol, resorcin, hydroquinone, etc.), etc. As the initiator, a polyether polyol obtained by addition-polymerizing an alkylene oxide such as ethylene oxide, propylene oxide or butylene oxide can be mentioned. Specific examples include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and the like.

Examples of polycaprolactone polyols include caprolactone-based polyester diols obtained by ring-opening polymerization of cyclic ester monomers such as ε-caprolactone and σ-valerolactone.

As the polycarbonate polyol, for example, a polycarbonate polyol obtained by polycondensing the above polyol component and phosgene; the above polyol component, dimethyl carbonate, diethyl carbonate, diprobyl carbonate, diisopropyl carbonate, dibutyl carbonate, ethylbutyl carbonic acid, ethylene carbonate, Polycarbonate polyols obtained by transesterification condensation with carbonic acid diesters such as propylene carbonate, diphenyl carbonate and dibenzyl carbonate; copolymerized polycarbonate polyols obtained by using two or more of the above polyol components together; the above various polycarbonate polyols and carboxyl group-containing Polycarbonate polyol obtained by esterification reaction with a compound; Polycarbonate polyol obtained by etherification reaction between the above various polycarbonate polyols and hydroxyl group-containing compound; Obtained by transesterification reaction between the above various polycarbonate polyols and ester compound Polycarbonate polyol; Polycarbonate polyol obtained by transesterification of the above-mentioned various polycarbonate polyols and hydroxyl group-containing compounds; Polyester-based polycarbonate polyol obtained by polycondensation reaction of the above-mentioned various polycarbonate polyols and dicarboxylic acid compounds; And a alkylene oxide copolymerized polyether-based polycarbonate polyol;

Examples of castor oil-based polyols include castor oil-based polyols obtained by reacting castor oil fatty acid with the above polyol component. Specific examples include castor oil-based polyols obtained by reacting castor oil fatty acid with polypropylene glycol.

The polyfunctional isocyanate compound (B) may be only one type, or may be two or more types.

As the polyfunctional isocyanate compound (B), any suitable polyfunctional isocyanate compound that can be used in the urethanization reaction can be adopted. Examples of such a polyfunctional isocyanate compound (B) include a polyfunctional aliphatic isocyanate compound, a polyfunctional alicyclic isocyanate compound, and a polyfunctional aromatic isocyanate compound.

Examples of the polyfunctional aliphatic isocyanate compound include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, 2,4. 4-trimethylhexamethylene diisocyanate and the like can be mentioned.

Examples of the polyfunctional alicyclic isocyanate compound include 1,3-cyclopentene diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, Examples thereof include hydrogenated tolylene diisocyanate and hydrogenated tetramethylxylylene diisocyanate.

Examples of the polyfunctional aromatic diisocyanate compound include phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, and , 4'-toluidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, xylylene diisocyanate and the like.

Examples of the polyfunctional isocyanate compound (B) also include trimethylolpropane adducts of various polyfunctional isocyanate compounds as described above, burettes reacted with water, trimers having an isocyanurate ring, and the like. Also, these may be used in combination.

The content of the polyfunctional isocyanate compound (B) is preferably 5% by weight to 60% by weight, more preferably 8% by weight to 60% by weight, based on the polyol (A). %, and more preferably 10% to 60% by weight. By adjusting the content ratio of the polyfunctional isocyanate compound (B) within the above range, the effect of the present invention can be further exhibited.

The urethane resin is typically obtained by curing a composition containing a polyol (A) and a polyfunctional isocyanate compound (B). In such a composition, any appropriate other component other than the polyol (A) and the polyfunctional isocyanate compound (B) may be contained within a range not impairing the effects of the present invention. Such other components include, for example, catalysts, resin components other than polyurethane resins, tackifiers, inorganic fillers, organic fillers, metal powders, pigments, foils, softeners, plasticizers, Examples include antiaging agents, conductive agents, antioxidants, ultraviolet absorbers, light stabilizers, surface lubricants, leveling agents, corrosion inhibitors, heat stabilizers, polymerization inhibitors, lubricants, solvents and the like.

As a method for curing a composition containing a polyol (A) and a polyfunctional isocyanate compound (B) to obtain a urethane-based resin, the effects of the present invention such as a urethanization reaction method using bulk polymerization or solution polymerization can be obtained. Any appropriate method can be adopted within a range that does not impair the property.

(Other resins)
The top coat layer serves as a binder as long as it does not significantly impair the performance of the adhesive film, and as a binder, other resins (for example, acrylic resin, acrylic-styrene resin, acrylic-silicone resin, silicone resin, polysilazane). At least one resin selected from resins, fluororesins and polyolefin resins) may be further contained. In a preferred embodiment of the topcoat layer, the binder of the topcoat layer is substantially composed of at least one selected from the group consisting of polyester resin and urethane resin, and is composed of polyester resin and urethane resin in the binder. The proportion of at least one selected from the group is preferably 98% by weight to 100% by weight, more preferably 99% by weight to 100% by weight, and further preferably 99.5% by weight to 100% by weight. is there. The proportion of the binder in the entire top coat layer is preferably 15% by weight to 95% by weight, more preferably 25% by weight to 80% by weight.

<Slip agent>
The slip agent preferably contains an ester of a higher fatty acid and a higher alcohol (hereinafter sometimes referred to as "wax ester").

The “higher fatty acid” is preferably a carboxylic acid having 8 or more carbon atoms, and the number of carbon atoms is more preferably 10 or more, further preferably 10 to 40. The carboxylic acid is preferably a monovalent carboxylic acid.

The “higher alcohol” is preferably an alcohol having 6 or more carbon atoms, and the number of carbon atoms is more preferably 10 or more, further preferably 10 to 40. The alcohol is preferably a monohydric or dihydric alcohol, more preferably a monohydric alcohol.

The topcoat layer having a composition containing a combination of such a wax ester and the above-mentioned binder is unlikely to be whitened even when kept under high temperature and high humidity conditions. Therefore, the adhesive film provided with the base material having such a top coat layer can have a higher appearance quality.

The following reasons can be considered as reasons why excellent whitening resistance (for example, the property that whitening is difficult even when kept under high temperature and high humidity conditions) is achieved by the topcoat layer having the above composition. That is, it is presumed that the conventionally used silicone-based lubricant exhibits a function of imparting slipperiness to the surface of the topcoat layer by bleeding. However, in these silicone lubricants, the degree of bleeding is likely to change depending on the storage conditions (temperature, humidity, aging, etc.). Therefore, for example, when the adhesive film is kept under normal storage conditions (for example, 25° C. and 50% RH), it has a suitable slipperiness for a relatively long period (for example, about 3 months) immediately after the production of the adhesive film. When the amount of the silicone-based lubricant used is set so that the pressure-sensitive adhesive film is obtained, when this adhesive film is stored under high temperature and high humidity conditions (for example, 60° C. and 95% RH) for 2 weeks, bleeding of the lubricant excessively proceeds. Will end up. Such excessively bleeding silicone-based lubricant may cause whitening of the top coat layer (and thus the adhesive film).

As a preferred embodiment of the top coat layer, a specific combination of wax ester as a slip agent and polyester resin as a binder is adopted. With such a combination of the slip agent and the binder, the degree of bleeding of the wax ester from the top coat layer is less likely to be affected by storage conditions. This can improve the whitening resistance of the adhesive film.

As the wax ester, one or more compounds represented by the general formula (W) can be preferably adopted.
X-COO-Y (W)

X and Y in formula (W) are each independently preferably a hydrocarbon group having 10 to 40 carbon atoms, and the number of carbon atoms is more preferably 10 to 35, and further preferably 14 To 35, particularly preferably 20 to 32. If the number of carbon atoms is too small, the effect of imparting slipperiness to the top coat layer may be insufficient. The above hydrocarbon group may be either a saturated hydrocarbon group or an unsaturated hydrocarbon group. The above-mentioned hydrocarbon group is preferably a saturated hydrocarbon group. The above hydrocarbon group may have a structure containing an aromatic ring, or may have a structure containing no aromatic ring (aliphatic hydrocarbon group), or a structure containing an aliphatic ring. May be a hydrocarbon group (alicyclic hydrocarbon group) or a chain (including straight chain and branched chain) hydrocarbon group.

The wax ester is a compound in which X and Y in the formula (W) are each independently a chain alkyl group having 10 to 40 carbon atoms, more preferably 10 to 40 carbon atoms. It is a compound that is a linear alkyl group. Specific examples of such compounds, for example, cerotic myricyl _{_{_{_{(CH 3 (CH 2) 24}}}} COO (CH 2) 29 CH 3), myricyl palmitate _{_{_{(CH 3 (CH 2) 14}}} COO (CH 2) 29 CH _3), cetyl palmitate _{_{_{_{(CH 3 (CH 2) 14}}}} COO (CH 2) 15 CH 3), stearyl stearyl _{_{_{(CH 3 (CH 2) 16}}} COO (CH 2) 17 CH 3) , and the like.

The wax ester has a melting point of preferably 50° C. or higher, more preferably 60° C. or higher, further preferably 70° C. or higher, particularly preferably 75° C. or higher. With such a wax ester, higher whitening resistance can be realized. The wax ester preferably has a melting point of 100° C. or lower. Since such a wax ester has a high effect of imparting slipperiness, it can form a top coat layer having higher scratch resistance. It is also preferable that the melting point of the wax ester is 100° C. or lower from the viewpoint of easily preparing an aqueous dispersion of the wax ester. As such a wax ester, for example, myricyl cerotate can be preferably adopted.

A natural wax containing such a wax ester can be used as a raw material for the top coat layer. As such a natural wax, the content ratio of the above-mentioned wax ester (the total content ratio of the wax esters when two or more kinds of wax esters are contained) is preferably more than 50% by weight based on the nonvolatile content (NV). Most, more preferably 65% by weight or more, and further preferably 75% by weight or more. Examples of such a natural wax include carnauba wax (generally, containing myricyl cerotate in an amount of preferably 60% by weight or more, more preferably 70% by weight or more, and further preferably 80% by weight or more). And vegetable waxes such as wax; animal waxes such as beeswax and whale wax; and the like. The melting point of such natural wax is preferably 50° C. or higher, more preferably 60° C. or higher, further preferably 70° C. or higher, particularly preferably 75° C. or higher. As a raw material for the top coat layer, a chemically synthesized wax ester may be used, or a natural wax purified to improve the purity of the wax ester may be used. These raw materials may be only one kind or two or more kinds.

The proportion of the slip agent in the entire top coat layer is preferably 5% by weight to 50% by weight, more preferably 10% by weight to 40% by weight. If the content of the slipping agent is too low, the scratch resistance may be lowered. If the content of the slip agent is too high, the effect of improving the whitening resistance may be insufficient.

The top coat layer may contain other slip agent in addition to the wax ester. Examples of other lubricants include wax esters such as petroleum wax (paraffin wax), mineral wax (montane wax etc.), higher fatty acid (cerotic acid etc.) and neutral fat (palmitic acid triglyceride etc.). Other various waxes are listed. Further, in addition to the wax ester, a silicone lubricant, a fluorine lubricant, etc. may be contained. A preferred embodiment of the top coat layer is a form in which a silicone-based lubricant and a fluorine-based lubricant are not substantially contained. For example, the total content of the silicone-based lubricant and the fluorine-based lubricant is preferably 0 or less. It is 0.01% by weight or less, more preferably the detection limit or less.

The topcoat layer is an antistatic component, a cross-linking agent, an antioxidant, a colorant (pigment, dye, etc.), a fluidity adjusting agent (thixotropic agent, thickener, etc.), a film-forming aid, an interface, if necessary. Additives such as activators (defoaming agents, dispersants, etc.), preservatives and the like may be contained.

<Antistatic component of top coat layer>
A preferred embodiment of the topcoat layer contains an antistatic component. The antistatic component is a component capable of exhibiting the action of preventing or suppressing the charge of the adhesive film. When the top coat layer contains an antistatic component, as the antistatic component, for example, an organic or inorganic conductive substance, various antistatic agents, etc. can be used. It is also possible to use antistatic agents which can be used in the antistatic layers mentioned above.

As the organic conductive substance, a quaternary ammonium salt, a pyridinium salt, a cationic antistatic agent having a cationic functional group such as a primary amino group, a secondary amino group, and a tertiary amino group; a sulfonate or a sulfate ester salt. , Phosphonate, phosphate ester and other anionic antistatic agents having anionic functional groups; alkylbetaine and its derivatives, imidazoline and its derivatives, alanine and its derivatives, etc. zwitterionic antistatic agents; amino alcohols and Nonionic antistatic agents such as derivatives thereof, glycerin and derivatives thereof, polyethylene glycol and derivatives thereof; polymerization of monomers having the above-mentioned cation-type, anion-type, and zwitterion-type ion conductive groups (for example, quaternary ammonium salt groups) or Ion conductive polymers obtained by copolymerization; conductive polymers such as polythiophene, polyaniline, polypyrrole, polyethyleneimine, and allylamine polymers; and the like. Only one kind of such antistatic agent may be used, or two or more kinds thereof may be used.

Examples of the inorganic conductive substance include tin oxide, antimony oxide, indium oxide, cadmium oxide, titanium oxide, zinc oxide, indium, tin, antimony, gold, silver, copper, aluminum, nickel, chromium, titanium, iron and cobalt. , Copper iodide, ITO (indium oxide/tin oxide), ATO (antimony oxide/tin oxide), and the like. Only one kind of such inorganic conductive material may be used, or two or more kinds thereof may be used.

Examples of the antistatic agent include a cationic antistatic agent, an anionic antistatic agent, a zwitterionic antistatic agent, a nonionic antistatic agent, and the above-mentioned cationic, anionic, and zwitterionic ionically conductive groups. Examples thereof include ion conductive polymers obtained by polymerizing or copolymerizing monomers.

When the top coat layer contains an antistatic component, the antistatic component preferably contains an organic conductive substance. As the organic conductive substance, various conductive polymers can be preferably used. With such a configuration, both good antistatic properties and high scratch resistance can be achieved.

Examples of conductive polymers include polythiophene, polyaniline, polypyrrole, polyethyleneimine, and allylamine-based polymers. Only one kind of such conductive polymer may be used, or two or more kinds thereof may be used. It may also be used in combination with other antistatic components (inorganic conductive substances, antistatic agents, etc.).

The amount of the conductive polymer used is preferably 1 part by weight to 100 parts by weight, more preferably 2 parts by weight to 70 parts by weight, and further preferably 100 parts by weight of the binder contained in the top coat layer. It is 3 to 50 parts by weight. If the amount of the conductive polymer used is too small, the antistatic effect may be reduced. If the amount of the conductive polymer used is too large, the compatibility of the conductive polymer in the topcoat layer tends to be insufficient, and the appearance quality of the topcoat layer may deteriorate or the solvent resistance may decrease. ..

The conductive polymer is preferably polythiophene or polyaniline. The polythiophene has a polystyrene-equivalent weight average molecular weight Mw of preferably 40×10 ⁴ or less, more preferably 30×10 ⁴ or less. The polyaniline has a polystyrene-equivalent weight average molecular weight Mw of preferably 50×10 ⁴ or less, more preferably 30×10 ⁴ or less. The polystyrene-equivalent weight average molecular weight Mw of the conductive polymer is preferably 0.1×10 ⁴ or more, more preferably 0.5×10 ⁴ or more. In this specification, polythiophene refers to a polymer of unsubstituted or substituted thiophene. Examples of the substituted thiophene polymer include poly(3,4-ethylenedioxythiophene).

As a method for forming the topcoat layer, when a method of applying a coating material for forming a topcoat layer to a substrate and drying or curing is adopted, as the conductive polymer used for preparing the coating material, A conductive polymer dissolved or dispersed in water (conductive polymer aqueous solution) can be preferably used. Such a conductive polymer aqueous solution is prepared by, for example, dissolving a conductive polymer having a hydrophilic functional group (a conductive polymer that can be synthesized by a method such as copolymerizing a monomer having a hydrophilic functional group in the molecule) in water. Alternatively, it can be prepared by dispersing. Examples of the hydrophilic functional group include sulfo group, amino group, amide group, imino group, hydroxyl group, mercapto group, hydrazino group, carboxyl group, quaternary ammonium group, sulfuric acid ester group (—O—SO ₃ H), phosphorus Examples thereof include acid ester groups (eg, —O—PO(OH) ₂ ). Such a hydrophilic functional group may form a salt. Examples of commercially available polythiophene aqueous solution include "Denatron" series manufactured by Nagase Chemtec Co., Ltd. Examples of commercial products of the polyaniline sulfonic acid aqueous solution include trade name “aqua-PASS” manufactured by Mitsubishi Rayon Co., Ltd.

In the preparation of the coating material, it is preferable to use an aqueous polythiophene solution. As the polythiophene aqueous solution, a polythiophene aqueous solution containing polystyrene sulfonate (PSS) (for example, a form in which PSS is added as a dopant to polythiophene) is preferable. Such an aqueous polythiophene solution may contain polythiophene:PSS, preferably in a mass ratio of 1:1 to 1:10. The total content of polythiophene and PSS in such an aqueous polythiophene solution is preferably 1% by mass to 5% by mass. Examples of commercial products of such polythiophene aqueous solution include H.I. C. The trade name “Baytron” of Stark and the like can be mentioned. When the polythiophene aqueous solution containing PSS is used as described above, the total amount of polythiophene and PSS is preferably 5 parts by weight to 200 parts by weight, and more preferably 10 parts by weight with respect to 100 parts by weight of the binder. It is from 100 to 100 parts by weight, and more preferably from 25 to 70 parts by weight.

The topcoat layer optionally contains a conductive polymer and one or more other antistatic components (organic conductive substances other than conductive polymers, inorganic conductive substances, antistatic agents, etc.) together. You may stay. Preferably, the top coat layer contains substantially no antistatic component other than the conductive polymer. That is, it is preferable that the antistatic component contained in the topcoat layer consists essentially of a conductive polymer.

<Crosslinking agent>
The top coat layer preferably contains a crosslinking agent. As the cross-linking agent, a cross-linking agent such as a melamine-based cross-linking agent, an isocyanate-based cross-linking agent, or an epoxy-based cross-linking agent that is used for cross-linking general resins can be appropriately selected and used. By using such a cross-linking agent, at least one of the effects of improved scratch resistance, improved solvent resistance, improved print adhesion, and reduced friction coefficient (that is, improved slippage) is realized. obtain. Preferably, the cross-linking agent comprises a melamine-based cross-linking agent. It may be a top coat layer in which the cross-linking agent substantially consists of a melamine-based cross-linking agent (melamine-based resin) (that is, does not substantially contain a cross-linking agent other than the melamine-based cross-linking agent).

<One preferable embodiment of the top coat layer>
In one preferred embodiment of the top coat layer, when the material of the base material layer is at least one selected from polyimide and polyether ether ketone, the top coat layer contains a binder containing a urethane resin and an antistatic component. It is a mode. In this way, by using a binder containing a urethane resin as the binder of the antistatic component of the top coat layer, the top surface of the base material layer made of at least one selected from polyimide and polyether ether ketone is used. The coatability of the coat layer becomes excellent, the appearance may be good, and the excellent antistatic property may be exhibited.

As the binder of the antistatic component of the topcoat layer, a binder containing a polyester resin is often preferable, but the material for the base material layer is at least one selected from polyimide and polyetheretherketone for a specific base material layer. In some cases, the binder containing the polyester resin may have a low affinity, and the appearance of the topcoat layer after coating and forming may be deteriorated, or the excellent antistatic property may not be exhibited. As described above, when the material of the base material layer is at least one selected from polyimide and polyetheretherketone, if the top coat layer contains a binder containing a urethane resin and an antistatic component, The coatability of the topcoat layer on the surface of the base material layer becomes excellent, the appearance may be good, and the excellent antistatic property may be exhibited.

<Formation of top coat layer>
The topcoat layer is formed by a method including applying a liquid composition (a coating material for forming a topcoat layer) in which the above resin components and additives used as necessary are dispersed or dissolved in a suitable solvent to a substrate. It can be suitably formed. For example, a method in which the above-mentioned coating material is applied to the first surface of a base material, dried, and if necessary, a curing treatment (heat treatment, ultraviolet treatment, etc.) can be preferably adopted. The NV (nonvolatile content) of the coating material is preferably 5% by weight or less, more preferably 0.05% by weight to 5% by weight, further preferably 0.05% by weight to 1% by weight, Particularly preferably, it is 0.10% by weight to 1% by weight. When forming a thin topcoat layer, the NV of the coating material is preferably 0.05% by weight to 0.50% by weight, and more preferably 0.10% by weight to 0.30% by weight. To do. By using the low NV coating material as described above, a more uniform top coat layer can be formed.

As the solvent that constitutes the coating material for forming the top coat layer, one that can stably dissolve or disperse the components forming the top coat layer is preferable. Such a solvent may be an organic solvent, water, or a mixed solvent thereof. Examples of the organic solvent include esters such as ethyl acetate; ketones such as methyl ethyl ketone, acetone and cyclohexanone; cyclic ethers such as tetrahydrofuran (THF) and dioxane; aliphatic or alicyclic carbonization such as n-hexane and cyclohexane. Hydrogens; aromatic hydrocarbons such as toluene and xylene; aliphatic or alicyclic alcohols such as methanol, ethanol, n-propanol, isopropanol, cyclohexanol; alkylene glycol monoalkyl ethers (eg ethylene glycol monomethyl ether, Ethylene glycol monoethyl ether), glycol ethers such as dialkylene glycol monoalkyl ether; and the like. Preferably, the solvent constituting the coating material for forming the topcoat layer is water or a mixed solvent containing water as a main component (for example, a mixed solvent of water and ethanol).

<Properties of top coat layer>
The thickness of the top coat layer is preferably 3 nm to 500 nm, more preferably 3 nm to 100 nm, and further preferably 3 nm to 60 nm. If the thickness of the top coat layer is too large, the transparency (light transmittance) of the pressure-sensitive adhesive film may be likely to decrease. If the thickness of the top coat layer is too small, it may be difficult to uniformly form the top coat layer, and for example, in the thickness of the top coat layer, there may be a large variation in thickness depending on the location. However, the appearance of the pressure-sensitive adhesive film may be likely to be uneven.

The thickness of the top coat layer can be understood by observing the cross section of the top coat layer with a transmission electron microscope (TEM). For example, for a target sample (a base material having a top coat layer formed thereon, an adhesive film including a base material, etc.), a heavy metal dyeing treatment is performed for the purpose of clarifying the top coat layer, followed by resin embedding, The result obtained by TEM observation of the cross section of the sample by the ultrathin section method can be preferably adopted as the thickness of the topcoat layer. As the TEM, for example, a TEM (model “H-7650”) manufactured by Hitachi, Ltd. can be used. In Examples described later, a cross-sectional image obtained under the conditions of accelerating voltage: 100 kV and magnification: 60,000 times was binarized, and then the cross-sectional area of the top coat was divided by the sample length in the visual field. By doing so, the thickness of the top coat layer (average thickness in the visual field) is measured. The heavy metal dyeing process may be omitted if the topcoat layer can be observed sufficiently clearly without heavy metal dyeing. Alternatively, there is a calibration curve for the correlation between the thickness grasped by the TEM and the detection result by various thickness detection devices (for example, surface roughness meter, interference thickness meter, infrared spectrophotometer, various X-ray diffractometers, etc.). The thickness of the top coat layer may be determined by preparing the above and calculating.

The surface resistivity measured on the surface of the top coat layer is preferably 10 ¹² Ω or less, more preferably 10 ⁴ Ω to 10 ¹² Ω, further preferably 10 ⁴ Ω to 10 ¹¹ Ω, and particularly preferably It is preferably 5×10 ⁴ Ω to 10 ¹⁰ Ω, and most preferably 10 ⁴ Ω to 10 ⁹ Ω. The pressure-sensitive adhesive film having such a surface resistivity can be suitably used as a pressure-sensitive adhesive film used, for example, in the processing or transportation process of articles such as liquid crystal cells and semiconductor devices that are sensitive to static electricity. The surface resistivity value can be calculated from the surface resistance value measured in an atmosphere of 23° C. and 50% RH using a commercially available insulation resistance measuring device.

The friction coefficient of the top coat layer is preferably 0.4 or less. When a top coat layer with a low coefficient of friction is used in this way, when a load (a load that causes scratches) is applied to the top coat layer, the load is received along the surface of the top coat layer and the friction caused by the load The power can be reduced. As a result, cohesive failure of the topcoat layer (damage mode in which the topcoat layer breaks inside) and interface failure (damage mode in which the topcoat layer peels from the back surface of the substrate) are less likely to occur. Therefore, it is possible to further prevent the occurrence of scratches on the adhesive film. The lower limit of the coefficient of friction is preferably 0.1 or more, more preferably 0.15 or more, in consideration of the balance with other characteristics (for example, appearance quality and printability). As the friction coefficient, for example, a value obtained by rubbing the surface of the top coat layer with a vertical load of 40 mN under a measurement environment of 23° C. and 50% RH can be adopted. The amount of the slip agent used may be set so that a preferable coefficient of friction is realized. For adjusting the friction coefficient, it is also effective to increase the crosslink density of the topcoat layer by adding a crosslinker or adjusting film forming conditions.

It is preferable that the back surface (surface of the top coat layer) of the adhesive film has a property that it can be easily printed with an oil-based ink (for example, using an oil-based marking pen). In such a pressure-sensitive adhesive film, the identification number or the like of the adherend to be protected in the process of processing or transporting the adherend (for example, an optical component) that is performed with the pressure-sensitive adhesive film attached, It is suitable for displaying and displaying. Therefore, a surface protective film having excellent printability in addition to appearance quality is preferable. For example, it is preferable that the solvent is alcoholic and has high printability with respect to an oil-based ink of a type including a pigment. Further, it is preferable that the printed ink is difficult to be removed due to rubbing or transfer (that is, the printing adhesion is excellent). The pressure-sensitive adhesive film preferably has solvent resistance to the extent that when the print is corrected or erased, the print is wiped off with alcohol (for example, ethyl alcohol) so that the appearance is not significantly changed.

The topcoat layer preferably contains a wax ester as a slip agent, so that the surface of the topcoat layer is subjected to further release treatment (for example, any suitable release treatment such as a silicone-based release agent or a long-chain alkyl-based release agent). Sufficient slipperiness (for example, the above-mentioned preferable friction coefficient) can be realized even in a mode in which the treatment of applying the agent and drying is not performed. In this manner, the embodiment in which the surface of the top coat layer is not further subjected to the peeling treatment can prevent the whitening (for example, the whitening due to the storage under the heating and humidifying conditions) caused by the peeling treatment agent. It is preferable in terms. It is also advantageous in terms of solvent resistance.

The pressure-sensitive adhesive film may be embodied in a mode including other layers in addition to the base material, the pressure-sensitive adhesive layer, and the top coat layer. Examples of the arrangement of the "other layer" include between the first surface (back surface) of the base material and the top coat layer, between the second surface (front surface) of the base material and the adhesive layer, and the like. The layer arranged between the back surface of the substrate and the topcoat layer can be, for example, a layer containing an antistatic component (antistatic layer). The layer arranged between the front surface of the substrate and the pressure-sensitive adhesive layer may be, for example, an undercoat layer (anchor layer) that enhances the anchoring property of the pressure-sensitive adhesive layer to the second surface, an antistatic layer, or the like. The pressure-sensitive adhesive film may have a structure in which an antistatic layer is disposed on the front surface of a substrate, an anchor layer is disposed on the antistatic layer, and a pressure-sensitive adhesive layer is disposed thereon.

≪<<Foldable devices and Rollable devices>>»
Since the pressure-sensitive adhesive film of the present invention is excellent in flexibility and transparency, for example, a bendable device (a bendable device), a foldable device (a foldable device), or a rollable device (having a movable bending portion) (a bendable device). It is suitable for a rollable device). The pressure-sensitive adhesive film of the present invention is particularly excellent in flexibility and transparency, and thus is suitable for a foldable device (foldable device) and a rollable device (rollable device) that have been difficult to apply until now. Can be prepared for.

The foldable device of the present invention includes the adhesive film of the present invention. The foldable device of the present invention may include any appropriate other member as long as it has the adhesive film of the present invention.

The rollable device of the present invention includes the adhesive film of the present invention. The rollable device of the present invention may include any appropriate other member as long as it has the adhesive film of the present invention.

FIG. 1 is a schematic cross-sectional view showing one embodiment of the foldable device of the present invention as a representative example of one usage form of the adhesive film of the present invention. 1, a foldable device 1000 of the present invention includes a cover film 10, an adhesive layer 20, a polarizing plate 30, an adhesive layer 40, a touch sensor 50, an adhesive layer 60, an OLED 70, and an adhesive film 100 of the present invention. .. The adhesive film 100 of the present invention is composed of an adhesive layer 80 and a base material layer 90 in FIG. The pressure-sensitive adhesive layer 20, the pressure-sensitive adhesive layer 40, and the pressure-sensitive adhesive layer 60. It may be a pressure-sensitive adhesive layer containing a pressure-sensitive adhesive having the same composition as the pressure-sensitive adhesive layer 80 constituting the pressure-sensitive adhesive film 100 of the present invention, or may be a pressure-sensitive adhesive layer containing a pressure-sensitive adhesive having a different composition.

Since the pressure-sensitive adhesive film of the present invention is excellent in flexibility and transparency, for example, a bendable device (a bendable device), a foldable device (a foldable device), or a rollable device (having a movable bending portion) (a bendable device). It can suitably be provided on the back side of the rollable device) (opposite the display side). FIG. 1 is a diagram provided on a back surface (a surface opposite to a display surface) of a foldable device (a foldable device).

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. However, the present invention is not limited thereto. In the following description, “part” and “%” are based on weight unless otherwise specified.

<tanδ>
The viscoelasticity measuring device "RSA-G2" (manufactured by TA Instruments Japan Co., Ltd.) was used in the tensile mode to measure the sample size width 5 mm x distance 15 mm and axial force 100 g. In the strain sweep mode, the frequency is 1 Hz, the measurement temperature is 90° C., the immersion time is 60 seconds, the strain measurement range is set from 0.01% to 1.0%, and the strain is measured during that period. I went. The value of tan δ at each strain was graphed, and the tan δ of 0.1% strain and 0.7% strain was obtained from the graph. As for the thickness, it is assumed that both the storage modulus and loss modulus of the base material have a large rigidity with respect to the adhesive film, and the influence of the adhesive can be ignored, so only the thickness of the base material excluding the thickness of the adhesive is entered. Was measured.
Tan δ was calculated by the following formula.
tan δ=loss elastic modulus/storage elastic modulus

<Bending test>
As shown in FIG. 2, the flat pressure-sensitive adhesive film is fixed in a state of being sandwiched between the silicone-treated surfaces of the silicone-treated separator with the pressure-sensitive adhesive film bent at 6Φ so that the temperature is 90° C. For 48 hours. After that, the bending was released, and the film was allowed to stand at 23° C. and 50% RH for 24 hours, and then the angle of the bent film was measured. The case where it completely returned to the original state was set to 180 degrees, and the case where the bent state in the first fixing was maintained as it was was set to 0 degree.

<Peeling evaluation>
Adhesive film was attached to a PET film (Toray, S10) with a thickness of 50 μm, and the adhesive film was bent so that the adhesive film was on the inside as shown in FIG. 3 and kept at 90° C. for 48 hours, and then fixed. Was released, and peeling of the adhesive film from the PET film was visually observed. The evaluation was performed according to the following criteria.
Good: Peeling from the PET film is not seen.
X: Peeling from the PET film is seen.

<Measurement of haze and total light transmittance>
Haze meter HM-150 (manufactured by Murakami Color Research Laboratory Co., Ltd.) is used, and in accordance with JIS-K-7136, haze (%)=(Td/Tt)×100 (Td: diffuse transmittance, Tt: Total light transmittance) was calculated. The total light transmittance was measured according to JIS-K-7316.

<Young's modulus>
The sample piece was cut into a strip shape with a width of 10 mm, and the strip-shaped sample piece was pulled in a longitudinal direction at a chuck distance of 100 mm with a universal tensile compression tester (Tensilon) under a temperature environment of 25° C. to measure, Young's modulus was determined from the obtained SS (Strain-Strength) curve. The measurement conditions were a pulling speed of 200 mm/min and a chuck gap of 50 mm. The Young's modulus was calculated from the SS curve by drawing a graph of the SS curve, drawing a tangent line (linear equation) on the graph in the displacement range of 1 mm to 2 mm, and calculating from the slope of the tangent line.

<Adhesive strength>
The adhesive film was cut into a width of 25 mm and a length of 150 mm to obtain a sample for evaluation. In an atmosphere of a temperature of 23° C. and a humidity of 50% RH, the surface of the pressure-sensitive adhesive layer of the sample for evaluation was attached to a glass plate (Matsunami Glass Industry Co., Ltd., trade name: Micro Slide Glass S) by reciprocating a 2.0 kg roller once. I attached it. After curing for 30 minutes in an atmosphere of a temperature of 23° C. and a humidity of 50% RH, using a universal tensile tester (Minebea Co., product name: TCM-1kNB), peeling was performed at a peeling angle of 180 degrees and a pulling speed of 300 mm/min. Then, the adhesive strength was measured.

<Applicability>
The number of circular irregularities in the applied top coat layer (including the antistatic layer) is counted. Two sheets of A4 size were prepared and the average number was calculated.
2 or less were judged to be good, and 3 or more were judged to be defective. The circular uneven part is a part where the thickness of the top coat layer is thin and it is a defect in appearance, and the one that could not be applied at all because it repelled the antistatic agent was “Hajiki” And

<Surface resistance value (for Example 8)>
The layer on which the antistatic treatment layer was formed in Example 8 was measured with a volume resistance meter Model 152-1 152P-2P probe (manufactured by Trek Japan KK) at a voltage of 10V.

<Surface resistivity (for Examples 9 to 17 and Comparative Examples 6 to 9)>
In Examples 9 to 17 and Comparative Examples 6 to 9, a resistivity meter (manufactured by Mitsubishi Chemical Analytic, “HIRESTA UP MCP-HT450 type”) was used to bring the URS probe into contact with the surface without the adhesive layer of the adhesive film. The surface resistivity was measured under conditions of an applied voltage of 100 V and a voltage application time of 10 seconds.

[Production Example 1]: Preparation of adhesive composition A 2-Ethylhexyl acrylate (2EHA) as a monomer component: 63 parts by weight, N-vinyl-2-pyrrolidone (NVP): 15 parts by weight, methyl methacrylate (MMA) ): 9 parts by weight, 2-hydroxyethyl acrylate (HEA): 13 parts by weight, 2,2′-azobisisobutyronitrile as a polymerization initiator: 0.2 parts by weight, and acetic acid as a polymerization solvent. Ethyl: 133 parts by weight was put into a separable flask and stirred for 1 hour while introducing nitrogen gas. After removing the oxygen in the polymerization system in this way, the temperature was raised to 65° C. and the reaction was carried out for 10 hours, and then ethyl acetate was added to obtain a solution of the acrylic polymer (a) having a solid content concentration of 30% by weight. It was
Next, in the solution of the acrylic polymer (a1), an isocyanate-based crosslinking agent (trade name "Takenate D110N", manufactured by Mitsui Chemicals, Inc.) was added to 100 parts by weight of the acrylic polymer (a) (solid content) as a solid content. The pressure-sensitive adhesive composition A was prepared by adding 1 part by weight in terms of conversion.

[Production Example 2]: Preparation of adhesive composition B In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a condenser, 96.2 parts by weight of 2-ethylhexyl acrylate (2EHA) and hydroxyethyl were added. 3.8 parts by weight of acrylate (HEA), 0.2 parts by weight of 2,2′-azobisisobutyronitrile as a polymerization initiator, and 150 parts by weight of ethyl acetate were charged, and nitrogen gas was introduced with gentle stirring. Polymerization reaction was carried out for 6 hours while maintaining the liquid temperature in the flask at around 60°C to prepare a solution (40% by weight) of the acrylic polymer (b). The weight average molecular weight of the acrylic polymer (b) was 540,000.
Next, the acrylic polymer (b) solution (40% by weight) was diluted to 25% by weight with ethyl acetate, and 400 parts by weight of this solution (solid content 100 parts by weight) was added with a trifunctional isocyanate compound as a crosslinking agent. 4 parts by weight of isocyanuric hexamethylene diisocyanate (manufactured by Tosoh Corporation, Coronate HX) (4 parts by weight of solid content), dioctyltin dilaurate as a crosslinking catalyst (manufactured by Tokyo Fine Chemical Co., Enbilizer OL-1, 1% by weight ethyl acetate) Solution) 2 parts by weight (solid content 0.02 part by weight) and acetylacetone 3 parts by weight were added and mixed and stirred to prepare an adhesive composition B.

[Example 1]
A commercially available release liner (DIAFOIL MRF-38", manufactured by Mitsubishi Plastics, Inc.) was prepared. The pressure-sensitive adhesive composition A was applied to one surface (release surface) of the release liner so that the thickness after drying was 25 μm, and dried at 130° C. for 3 minutes. In this way, a pressure-sensitive adhesive layer having a thickness of 25 μm and composed of the acrylic pressure-sensitive adhesive A corresponding to the pressure-sensitive adhesive composition A was formed on the release surface of the release liner.
As the base material layer, a polyimide base material (trade name “Kapton”, manufactured by Toray DuPont Co., Ltd.) having a thickness of 50 μm was prepared. The pressure-sensitive adhesive layer formed on the release liner was attached to one surface of the base material layer. The release liner was left as it was on the pressure-sensitive adhesive layer and used to protect the surface of the pressure-sensitive adhesive layer (pressure-sensitive adhesive layer surface). The obtained structure was passed once through a laminator at 80° C. (0.3 MPa, speed 0.5 m/min), and then aged in an oven at 50° C. for 1 day. Thus, the adhesive film (1) was obtained.
The results are shown in Table 1.

[Example 2]
An adhesive film (2) was obtained in the same manner as in Example 1 except that a polyimide-based substrate having a thickness of 50 μm (trade name “UPILEX-50S”, manufactured by Ube Industries, Ltd.) was used as the substrate layer.
The results are shown in Table 1.

[Example 3]
An adhesive film (3) was obtained in the same manner as in Example 1 except that a polyimide base material having a thickness of 50 μm (trade name “Pixio BP”, manufactured by Kaneka Corporation) was used as the base material layer.
The results are shown in Table 1.

[Example 4]
An adhesive film (4) was obtained in the same manner as in Example 1 except that a polyimide base material having a thickness of 50 μm (trade name “UPILEX-50RN”, manufactured by Ube Industries, Ltd.) was used as the base material layer.
The results are shown in Table 1.

[Example 5]
Examples except that a 50 μm thick polyetheretherketone (PEEK)-based substrate (trade name “Shin-Etsu Sepla Film”, non-stretched film-forming high crystal, manufactured by Shin-Etsu Polymer Co., Ltd.) was used as the substrate layer The same procedure as in 1 was carried out to obtain an adhesive film (5).
The results are shown in Table 1.

[Example 6]
An adhesive film (6) was obtained in the same manner as in Example 1 except that a polyimide-based substrate having a thickness of 50 μm (trade name “Neoprim S100”, manufactured by Mitsubishi Gas Chemical Co., Inc.) was used as the substrate layer.
The results are shown in Table 1.

[Example 7]
An adhesive film (7) was obtained in the same manner as in Example 1 except that a 25 μm-thick polyetheretherketone (PEEK) base material (trade name “Expeak”, manufactured by Kurabo Industries) was used as the base material layer. It was
The results are shown in Table 1.

[Comparative Example 1]
An adhesive film (C1) was obtained in the same manner as in Example 1 except that a 25 μm-thick polyester base material (trade name “Lumirror S10”, manufactured by Toray) was used as the base material layer.
The results are shown in Table 1.

[Comparative example 2]
An adhesive film (C2) was obtained in the same manner as in Example 1 except that a 50 μm-thick polyester base material (trade name “Lumirror S10”, manufactured by Toray) was used as the base material layer.
The results are shown in Table 1.

[Comparative Example 3]
Same as Example 1 except that the pressure-sensitive adhesive composition B was used in place of the pressure-sensitive adhesive composition A, and a polyester base material having a thickness of 50 μm (trade name “Lumirror S10”, manufactured by Toray) was used as the base material layer. Then, an adhesive film (C3) was obtained.
The results are shown in Table 1.

[Comparative Example 4]
An adhesive film (C4) was obtained in the same manner as in Example 6 except that the adhesive composition B was used instead of the adhesive composition A.
The results are shown in Table 1.

[Comparative Example 5]
An adhesive film (C5) was obtained in the same manner as in Example 7, except that the adhesive composition B was used instead of the adhesive composition A.
The results are shown in Table 1.

[Production Example 3]: Preparation of antistatic-treated polyimide film A 10 parts by weight of antistatic agent (Microsolver RMd-142, manufactured by Solvex Co., containing tin oxide and polyester resin as main components), 30 parts by weight of water and methanol An antistatic agent solution was prepared by diluting with 70 parts by weight of a mixed solvent. The obtained antistatic agent solution was applied onto a 50 μm-thick polyimide base material (trade name “Kapton”, manufactured by Toray DuPont Co., Ltd.), which is a base material, using a Meyer bar, and at 130° C. for 1 minute. The solvent was removed by drying to form an antistatic layer (thickness: 0.2 μm), and an antistatic-treated polyimide film A was produced.

[Example 8]
An adhesive film (8) was obtained in the same manner as in Example 1 except that the antistatic-treated polyimide film A was used as the substrate. The surface resistance value was 5×10 ⁶ Ω.

[Manufacturing Example 4]: Preparation of polyimide film B for forming top coat layer <Preparation of coating material B>
Dispersion containing 25% by weight of a polyester resin (binder) as a binder (manufactured by Toyobo Co., Ltd., trade name "Binaroll MD-1480" (aqueous dispersion of saturated copolyester resin); hereinafter also referred to as "binder dispersion". ) Was prepared.
In addition, as a slip agent, an aqueous dispersion of carnauba wax (manufactured by Nippon Wax Co., Ltd., trade name “Purified Carnauba Waxus No. 2 powder”) (hereinafter also referred to as “slipper dispersion”) was prepared.
Further, an aqueous solution containing 0.5% by weight of poly(3,4-dioxythiophene) (PEDOT) and 0.8% by weight of polystyrene sulfonate (number average molecular weight 150,000) (PSS) as a conductive polymer (H C. Stark product, trade name “Baytron P”; hereinafter also referred to as “conductive polymer aqueous solution”) was prepared.
In a mixed solvent of water and ethanol (weight ratio of 50:50), 100 parts by weight of the binder dispersion liquid in solid content, 30 parts by weight of the slip agent dispersion liquid in solid content, and the conductive polymer aqueous solution were added. 50 parts by weight of solid content and 7 parts by weight of melamine-based cross-linking agent were added, and the mixture was stirred for about 20 minutes and mixed sufficiently. Thus, coating material B having an NV of about 0.15% by weight was prepared.
<Preparation of top coat layer forming polyimide film B>
The coating material B is applied by a bar coater on a polyimide base material (trade name "Kapton", manufactured by Toray DuPont Co., Ltd.) having a thickness of 50 μm, which is a base material, and dried by heating at 130° C. for 2 minutes. Let Thus, a base material (topcoat layer forming polyimide film B) having a transparent topcoat layer having a thickness of 10 nm on one surface of the polyimide base material was produced.

[Manufacturing Example 5]: Preparation of top coat layer forming polyimide film C <Preparation of coating material C>
An aqueous solution containing 25% by weight of a polyester urethane resin composed of 25 mol% of ethylene glycol, 25 mol% of neopetin glycol, 30 mol% of terephthalic acid, 10 mol% of adipic acid and 10 mol% of tolylene diisocyanate as a binder; hereinafter also referred to as "binder dispersion liquid". ) Was prepared.
In addition, as a slip agent, an aqueous dispersion of carnauba wax (manufactured by Nippon Wax Co., Ltd., trade name “Purified Carnauba Waxus No. 2 powder”) (hereinafter also referred to as “slipper dispersion”) was prepared.
Further, an aqueous solution containing 0.5% by weight of poly(3,4-dioxythiophene) (PEDOT) and 0.8% by weight of polystyrene sulfonate (number average molecular weight 150,000) (PSS) as a conductive polymer (H C. Stark product, trade name “Baytron P”; hereinafter also referred to as “conductive polymer aqueous solution”) was prepared.
Further, an aqueous solution containing 10% by weight of polyethylene glycol (PEG) alkyl ether and 10% by weight of polyvinyl alcohol was prepared as a dispersant.
In a mixed solvent of water and ethanol (weight ratio 50:50), 40 parts by weight of the binder dispersion liquid in solid content, 5 parts by weight of the slip agent dispersion liquid in solid content, and the conductive polymer aqueous solution. 8 parts by weight of solid content, 40 parts by weight of the above dispersant, and 7 parts by weight of melamine-based cross-linking agent were added, and the mixture was stirred for about 20 minutes and mixed sufficiently. Thus, coating material C having an NV of about 0.30% by weight was prepared.
<Preparation of top coat layer forming polyimide film C>
The coating material C is applied with a bar coater onto a polyimide base material (trade name "Kapton", manufactured by Toray DuPont Co., Ltd.) having a thickness of 50 μm, which is a base material, and heated at 130° C. for 2 minutes to dry. Let In this way, a base material (topcoat layer forming polyimide film C) having a transparent topcoat layer having a thickness of 50 nm on one surface of the polyimide base material was produced.

[Example 9]
An adhesive film (9) was obtained in the same manner as in Example 1 except that the top coat layer-forming polyimide film B was used as the substrate.
The results are shown in Table 2.

[Example 10]
An adhesive film (10) was obtained in the same manner as in Example 2 except that the top coat layer-forming polyimide film B was used as the substrate.
The results are shown in Table 2.

[Example 11]
An adhesive film (11) was obtained in the same manner as in Example 4, except that the top coat layer-forming polyimide film B was used as the substrate.
The results are shown in Table 2.

[Example 12]
An adhesive film (12) was obtained in the same manner as in Example 7 except that the top coat layer-forming polyimide film B was used as the substrate.
The results are shown in Table 2.

[Example 13]
An adhesive film (13) was obtained in the same manner as in Example 1 except that the top coat layer-forming polyimide film C was used as the substrate.
The results are shown in Table 2.

[Example 14]
An adhesive film (14) was obtained in the same manner as in Example 2 except that the top coat layer-forming polyimide film C was used as the substrate.
The results are shown in Table 2.

[Example 15]
An adhesive film (15) was obtained in the same manner as in Example 3 except that the top coat layer-forming polyimide film C was used as the substrate.
The results are shown in Table 2.

[Example 16]
An adhesive film (16) was obtained in the same manner as in Example 4, except that the top coat layer-forming polyimide film C was used as the substrate.
The results are shown in Table 2.

[Example 17]
An adhesive film (17) was obtained in the same manner as in Example 7, except that the top coat layer-forming polyimide film C was used as the substrate.
The results are shown in Table 2.

[Comparative Example 6]
An adhesive film (C6) was obtained in the same manner as in Comparative Example 1 except that the top coat layer-forming polyimide film B was used as the substrate.
The results are shown in Table 2.

[Comparative Example 7]
An adhesive film (C7) was obtained in the same manner as in Comparative Example 2 except that the top coat layer-forming polyimide film B was used as the substrate.
The results are shown in Table 2.

[Comparative Example 8]
An adhesive film (C8) was obtained in the same manner as in Comparative Example 1 except that the top coat layer-forming polyimide film C was used as the substrate.
The results are shown in Table 2.

[Comparative Example 9]
An adhesive film (C9) was obtained in the same manner as in Comparative Example 2 except that the top coat layer-forming polyimide film C was used as the substrate.
The results are shown in Table 2.

Since the pressure-sensitive adhesive film of the present invention is excellent in flexibility and transparency, for example, a bendable device (a bendable device), a foldable device (a foldable device), or a rollable device (having a movable bending portion) (a bendable device). It is suitable for a rollable device).

1000 Foldable device 100 Adhesive film 10 Cover film 20 Adhesive layer 30 Polarizing plate 40 Adhesive layer 50 Touch sensor 60 Adhesive layer 70 OLED
80 Adhesive Layer 90 Base Material Layer 1 6Φ Glass Rod 2 Silicone Treated Separator 3 Adhesive Layer 4 Fixed Glass 5 PET Film

Claims

An adhesive film having a base material layer and an adhesive layer,
Tan δ (0.7%) at a strain of 0.7% measured in the tensile mode of the viscoelasticity measuring device is 0.1 or less,
Adhesive film.
An adhesive film having a base material layer and an adhesive layer,
The difference between tan δ (0.7%) at a strain of 0.7% and tan δ (0.1%) at a strain of 0.1% measured in the tensile mode of the viscoelasticity measuring device (tan δ (0.7%)-tan δ (0.1%)) is 0.05 or less,
Adhesive film.
The bending angle is 60° to 180° after being bent at 6Φ and held at 90° C. for 48 hours, then released, and allowed to stand at 23° C. and 50% RH for 24 hours. The pressure-sensitive adhesive film according to 1 or 2.
The pressure-sensitive adhesive film according to any one of claims 1 to 3, which has a topcoat layer on the surface of the base material layer opposite to the surface having the pressure-sensitive adhesive layer.
The pressure-sensitive adhesive film according to claim 4, wherein the top coat layer contains a binder containing at least one selected from polyester resins and urethane resins.
The adhesive film according to claim 5, wherein the binder contains a urethane resin.
The pressure-sensitive adhesive film according to any one of claims 4 to 6, wherein the top coat layer contains an antistatic component.
The pressure-sensitive adhesive film according to claim 1, wherein the base layer has a Young's modulus at 23° C. of 6.0×10 7 Pa or more.
The pressure-sensitive adhesive film according to claim 8, wherein the material of the base material layer is at least one selected from polyimide and polyether ether ketone.
A material of the base material layer having a topcoat layer on the surface of the base material layer opposite to the surface having the pressure-sensitive adhesive layer, the topcoat layer containing a binder containing an urethane resin and an antistatic component. The pressure-sensitive adhesive film according to any one of claims 1 to 3, wherein is at least one selected from polyimide and polyether ether ketone.
The adhesive film according to any one of claims 1 to 10, which has a total light transmittance of 20% or more.
The pressure-sensitive adhesive film according to any one of claims 1 to 11, which has a haze of 15% or less.
The pressure-sensitive adhesive film according to any one of claims 1 to 12, wherein the pressure-sensitive adhesive layer has a pressure-sensitive adhesive force of 1 N/25 mm or more to a SUS plate at a pulling speed of 300 mm/min and a peel of 180 degrees at 23°C.
The pressure-sensitive adhesive film according to any one of claims 1 to 13, wherein the pressure-sensitive adhesive layer contains an acrylic pressure-sensitive adhesive.
The adhesive film according to any one of claims 1 to 14, which is attached to a foldable member.
The adhesive film according to claim 15, wherein the foldable member is an OLED.
The adhesive film according to any one of claims 1 to 16, which is attached to a rollable member.
The adhesive film according to claim 17, wherein the rollable member is an OLED.
Foldable device comprising the adhesive film according to any one of claims 1 to 14.
A rollable device comprising the adhesive film according to any one of claims 1 to 14.