KR20210083295A - Adhesive film, foldable device and rollable device - Google Patents

Abstract

Provided is an adhesive film having excellent flexibility and transparency. In addition, a foldable device and a rollable device having excellent flexibility are provided. The adhesive film of this invention is an adhesive film which has a base material layer and an adhesive layer, and tan-delta (0.7%) in 0.7% of the distortion measured in the tension mode of a viscoelasticity measuring apparatus is 0.1 or less. The adhesive film of this invention is an adhesive film which has a base material layer and an adhesive layer, and tan δ (0.7%) and tan δ (0.1%) in strain 0.1% in 0.7% of the strain measured in the tension mode of a viscoelasticity measuring apparatus. The difference (tanδ (0.7%) - tanδ (0.1%)) is 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.

BACKGROUND ART The pressure-sensitive adhesive film is used for reinforcement, surface protection, and the like of members having various shapes.

For example, when bonding an integrated circuit (IC) or a flexible printed circuit board (FPC) to a substrate (eg, a TFT substrate, etc.) of a semiconductor element, thermocompression bonding is usually performed with an anisotropic conductive film (ACF). . When performing such thermocompression bonding, an adhesion film may be previously bonded and reinforced on the back side of the board|substrate of a semiconductor element (for example, patent document 1).

In addition, as a manufacturing method of a flexible device or a rollable device that has been developed in recent years, in general, a release layer and a flexible or rollable film substrate are formed on a support substrate such as glass, and the film substrate is formed on the film substrate. An organic EL layer is formed on the TFT substrate and also thereon. And although a support substrate is peeled and a flexible device and a rollable device are manufactured, since a flexible display layer and a rollable display layer are very thin, a problem arises in a device by handling etc. For this reason, an adhesion film may be bonded and reinforced by this side (for example, patent document 2).

A substrate of a semiconductor element, a flexible device, or a rollable device may be repeatedly bent, and if the bending property of the adhesive film bonded to the back side of the substrate is bad, the recovery after bending deteriorates, or in the worst case, it is broken by repeated bending. It may be discarded or thrown away. Specifically, when an adhesive film is to be bonded to a bent portion (for example, a movable bent portion of a folding member, etc.), the following problems arise, for example.

When the pressure-sensitive adhesive film is bent at an angle, since a compressive force acts on the bent inner diameter side, the pressure-sensitive adhesive film itself is deformed to alleviate the force. Specifically, for example, wrinkles tend to occur.

When the adhesive film is bent at an angle, a tensile stress acts on the bent outer diameter side. For this reason, when the stress is relieve|relaxed, floating from a to-be-adhered body arises.

When the adhesive film is bent at an angle, the thickness of the location where the adhesive film bends or the location where it is stretched changes greatly, and even in such a state, wrinkles easily enter or float occurs. For example, when an adhesion film is pulled, the thickness of an adhesion film becomes thin significantly, and it becomes easy to generate|occur|produce the float from a to-be-adhered body.

Thus, in the conventional adhesive film, the uneven|corrugated tracking to a corner part or a bending part is not fully achieved.

In particular, when the adhesive film is bonded to the movable bent portion, since bending is repeated, it will be in a state in which folds (so-called "folds or creases") are produced on the adhesive film on the movable bent portion.

In addition, when bonding an integrated circuit (IC) or a flexible printed circuit board (FPC) to a semiconductor element substrate (eg, a TFT substrate, etc.) by thermocompression bonding, the bonding position is confirmed from the back side of the substrate and compression is performed. . For this reason, transparency is calculated|required by the adhesion film joined to the back side of a board|substrate.

Japanese Patent No. 560039 publication Japanese Patent No. 6376271

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

The adhesive film of the present invention,

It is an adhesive film having a base 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,

It is an adhesive film having a base layer and an adhesive layer,

The difference (tanδ(0.7%)-tanδ(0.1%)) between tanδ(0.7%) at 0.7% strain and tanδ(0.1%) at 0.1% strain measured in the tensile mode of the viscoelasticity measuring device is 0.05 or less to be.

In one embodiment, the adhesive film of this invention bends to 6 phi and hold|maintains at 90 degreeC for 48 hours, After releasing this bending|flexion, the bending angle after leaving it to stand at 23 degreeC and 50%RH for 24 hours is 60 degrees to 180 degrees.

In one embodiment, the adhesive film of this invention has a top coating layer in the surface on the opposite side to the surface which has the said adhesive layer of the said base material layer.

In one embodiment, the said top coating layer contains the binder containing at least 1 sort(s) chosen from a polyester resin and a urethane resin.

In one embodiment, the said binder contains a urethane-type resin.

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

In one embodiment, the Young's modulus in 23 degreeC of the said base material layer is 6.0x10 ⁷ Pa or more.

In one embodiment, the material of the said base material layer is at least 1 sort(s) chosen from polyimide and polyether ether ketone.

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

In one embodiment, the total light transmittance of the adhesive film of this invention is 20 % or more.

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

In one embodiment, the adhesive force with respect to the SUS board in 300 mm/min of tensile rates in 23 degreeC of the said adhesive layer, and a 180 degree peel is 1N/25mm or more.

In one embodiment, the said adhesive layer contains an acrylic adhesive.

In one embodiment, the adhesive film of this invention is affixed on a foldable member.

In one embodiment, the foldable member is an OLED.

In one embodiment, the adhesive film of this invention is affixed on a rollable member.

In one embodiment, the rollable member is an OLED.

The foldable device of this invention is provided with the said adhesive film.

The rollable device of this invention is equipped with the said adhesive film.

ADVANTAGE OF THE INVENTION According to this invention, the adhesive film excellent in flexibility and transparency can be provided. According to the present invention, it is also possible to provide a foldable device and a rollable device excellent in flexibility.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic sectional drawing which shows one Embodiment of the foldable device of this invention, and shows one use form of the adhesive film of this invention.
It is a schematic sectional drawing explaining the evaluation method of bending recovery property.
3 : is a schematic sectional drawing explaining the evaluation method of peeling evaluation.

≪≪ Adhesive film≫≫

The adhesive film of this invention has a base material layer and an adhesive layer. That is, if the adhesive film of this invention has a base material layer and an adhesive layer, it is a range which does not impair the effect of this invention, and may have arbitrary appropriate other layers.

One layer may be sufficient as a base material layer, and two or more layers may be sufficient as it. A base material layer is a point which can express the effect of this invention more, Preferably it is one layer.

One layer may be sufficient as an adhesive layer, and two or more layers may be sufficient as it. The pressure-sensitive adhesive layer is preferably one layer since the effect of the present invention can be expressed more.

The adhesive film of this invention may be equipped with arbitrary appropriate release liners for the protection until use, etc. on the surface on the opposite side of the base material layer of an adhesive layer.

As the release liner, for example, a release liner in which the surface of a substrate (liner substrate) such as paper or plastic film is treated with silicone, and a release liner in which the surface of a substrate (liner substrate) such as paper or plastic film is laminated with a polyolefin resin. and the like. As a plastic film as a liner base material, For example, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, a vinyl chloride copolymer film, a polyethylene terephthalate film, a polybutylene tere A phthalate film, a polyurethane film, an ethylene-vinyl acetate copolymer film, etc. are mentioned.

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

The pressure-sensitive 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, still more preferably 10 µm to 150 µm, particularly preferably 20 µm. to 100 μm, most preferably from 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 expressed.

The pressure-sensitive adhesive film of the present invention has a tan δ (0.7%) of 0.1 or less, preferably 0.09 or less, more preferably 0.08 or less, further preferably a tan δ (0.7%) at 0.7% of strain measured in the tensile mode of the viscoelasticity measuring device. is 0.07 or less, particularly preferably 0.06 or less. When tan-delta (0.7%) of the adhesive film of this invention in 0.7% of the strain measured in the tension mode of the viscoelasticity measuring apparatus exists in the said range, the effect of this invention can be expressed more.

The tan-delta (0.7%) in 0.7% of strain measured in the tension mode of the viscoelasticity measuring apparatus of an adhesive film is an index|index which shows the loss tangent at the time of bending an adhesive film largely. When the present invention was completed, it was found based on various experimental data that the effect of the present invention can be more expressed when this value is within the above range. A 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 pressure-sensitive adhesive film of the present invention has a tan δ (0.1%) at a strain of 0.1% measured in the tensile mode of the viscoelasticity measuring device, preferably 0.1 or less, more preferably 0.08 or less, still more preferably 0.06 or less. and particularly preferably 0.05 or less. When tan-delta (0.1%) in 0.1% of strain measured in the tension mode of the viscoelasticity measuring apparatus of the adhesive film of this invention exists in the said range, the effect of this invention can be expressed more.

The tan-delta (0.1%) in 0.1% of strain measured in the tension mode of the viscoelasticity measuring apparatus of an adhesive film is an index|index which shows the loss tangent at the time of bending an adhesive film small. When the present invention was completed, it was discovered based on various experimental data that the effect of the present invention could be more expressed when this value was 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 is the difference between tan δ (0.7%) at strain 0.7% and tan δ (0.1%) at strain 0.1% (tan δ (0.7%) -tan δ ( 0.1%)) becomes like this. Preferably it is 0.05 or less, More preferably, it is 0.04 or less, More preferably, it is 0.03 or less. The difference between tan δ (0.7%) at strain 0.7% and tan δ (0.1%) at strain 0.1% (tan δ (0.7%) -tan δ () of the adhesive film of the present invention measured in the tensile mode of the viscoelasticity measuring device) 0.1%)) within the above range, the effect of the present invention can be more expressed.

Difference (tanδ (0.7%) - tan δ (0.1%)) between tanδ (0.7%) at strain 0.7% and tanδ (0.1%) at strain 0.1% of the adhesive film measured in the tensile mode of the viscoelasticity measuring device ) is an index showing the difference between the loss tangent when the pressure-sensitive adhesive film is greatly bent and the loss tangent when the pressure-sensitive adhesive film is bent small. When the present invention was completed, it was discovered based on various experimental data that the effect of the present invention could be more expressed when this value was within the above range.

The adhesive film of the present invention is bent at 6 phi and held at 90°C for 48 hours, then the bending is released, and the bending angle after leaving it to stand at 23°C and 50% RH for 24 hours is preferably 60 degrees to 180 degrees. and more preferably 80 degrees to 180 degrees, more preferably 100 degrees to 180 degrees, particularly preferably 120 degrees to 180 degrees, and most preferably 150 degrees to 180 degrees. If the bending angle of the adhesive film of the present invention is within the above range, the bending angle of the adhesive film of the present invention is within the above range, after releasing the bending and leaving it to stand for 24 hours at 90°C for 48 hours. The effect can be expressed more.

After bending to 6 phi of an adhesive film and holding it at 90 degreeC for 48 hours, the said bending|flexion is released, and the bending angle after leaving it to stand at 23 degreeC and 50%RH for 24 hours is an index|index showing recoverability after bending|flexion. After bending at 6 phi and holding at 90 degreeC for 48 hours, the said bending is released, and the measuring method of the bending angle after leaving it to stand at 23 degreeC and 50%RH for 24 hours is demonstrated in detail later.

Total light transmittance of the adhesive film of this invention becomes like this. Preferably it is 20 % or more, More preferably, it is 30 % or more, More preferably, it is 40 % or more, Especially preferably, it is 50 % or more, Most preferably is 60% or more. When the total light transmittance of the adhesive film of the present invention is within the above range, excellent transparency can be more expressed.

Haze of the adhesive film of this invention becomes like this. Preferably it is 15 % or less, More preferably, it is 13 % or less, More preferably, it is 10 % or less, Especially preferably, it is 8 % or less, Most preferably, it is 6 % or less. % or less. When the haze of the adhesive film of the present invention is within the above range, excellent transparency can be more expressed.

Since the adhesive film of this invention is excellent in flexibility and transparency, Preferably it is affixed to a foldable member. As the foldable member, any suitable member can be adopted as long as it is a member capable of repeated bending. As such a foldable member, a foldable optical member, a foldable electronic member, etc. are mentioned, for example, A foldable OLED is mentioned, for example.

Since the adhesive film of this invention is excellent in a flexibility and transparency, Preferably it is affixed to a rollable member. As a rollable member, any suitable member can be employ|adopted as long as it is a member which can be repeatedly wound and rewound. As such a rollable member, a rollable optical member, a rollable electronic member, etc. are mentioned, for example, A rollable OLED is mentioned typically.

≪Base layer≫

The thickness of the base layer is preferably 1 μm to 500 μm, more preferably 5 μm to 300 μm, still more preferably 10 μm to 100 μm, particularly preferably 15 μm to 80 μm, and most Preferably, it is 20 micrometers - 60 micrometers. When the thickness of the base layer is within the above range, the effect of the present invention may be more expressed.

The base layer has a Young's modulus at 23°C of preferably 6.0×10 ⁷ Pa or more, more preferably 1.0×10 ⁸ Pa or more, still more preferably 5.0×10 ⁸ Pa or more, particularly preferably 8.0×10 ⁸ Pa or more, and most preferably 1.0×10 ⁹ Pa or more. The upper limit of the Young's modulus at 23°C of the base layer is typically and preferably 1.0×10 ¹¹ Pa or less. When the Young's modulus at 23° C. of the base layer is within the above range, the effects of the present invention may be more expressed. If the Young's modulus at 23° C. of the base layer is too low, if the adhesive film is bent at an angle, there is a risk that the tension on the outer diameter side cannot be sufficiently maintained with respect to the compression on the inner diameter side, the thickness tends to change, There exists a possibility that it may become easy to generate|occur|produce floating|lifting from a complex. When the Young's modulus in 23 degreeC of a base material layer is too high, there exists a possibility that an adhesive film cannot be easily deformed. The measuring method of Young's modulus is demonstrated in detail later.

As a material of a base material layer, arbitrary appropriate materials can be employ|adopted in the range which does not impair the effect of this invention. As a material of such a base material layer, a resin material is mentioned typically.

As a resin material as a material of a base material layer, For example, polyimide (PI), polyether ether ketone (PEEK), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), poly Acrylic resins such as methyl methacrylate (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), fluororesin, cyclic olefin polymer, etc. can be heard

As a resin material as a material of a base material layer, from the point which can express the effect of this invention more, Preferably at least 1 type selected from polyimide (PI), polyether ether ketone (PEEK), and a cyclic olefin type polymer is mentioned 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, still more preferably 10 μm to 100 μm, particularly preferably 15 μm to 80 μm, and most Preferably, it is 20 micrometers - 60 micrometers. When the thickness of the pressure-sensitive adhesive layer is within the above range, the effect of the present invention can be more expressed.

The pressure-sensitive adhesive layer has a tensile rate of 300 mm/min at 23° C., and the adhesive force to a glass plate in a 180-degree peel, preferably 1 N/25 mm or more, more preferably 5 N/25 mm or more, still more preferably 10N/25mm or more, particularly preferably 12N/25mm or more, and most preferably 15N/25mm or more. The upper limit of the adhesive force with respect to the glass plate in 300 mm/min of tensile rate in 23 degreeC of an adhesive layer, and a 180 degree peel is typically, Preferably it is 1000 N/25 mm or less, More preferably, it is 5000 N/25 mm or less. and 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. The effect of this invention can be expressed more when the adhesive force with respect to the glass plate in 300 mm/min of tensile rates in 23 degreeC of an adhesive layer, and a 180 degree peel exists in the said range.

The pressure-sensitive adhesive layer contains a base polymer. The number of base polymers may be one, and 2 or more types may be sufficient as them. 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, and still more preferably from the viewpoint that the effect of the present invention can be expressed more. Preferably it is 40 wt% to 90 wt%, particularly preferably 45 wt% to 85 wt%, and most preferably 50 wt% to 80 wt%.

As the base polymer, any suitable polymer can be employed within a range that does not impair the effects of the present invention. At least 1 sort(s) preferably selected from an acryl-type polymer, a rubber-type polymer, a silicone-type polymer, and a urethane-type polymer is mentioned as a base polymer from the point which can express the effect of this invention more. That is, the pressure-sensitive adhesive layer is preferably 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, a urethane-based pressure-sensitive adhesive containing a urethane-based polymer At least one selected from the group consisting of. Since the effect of this invention can be expressed further, an adhesive layer, Preferably an acrylic adhesive is included. Hereinafter, as a representative example of the pressure-sensitive adhesive that may be included in the pressure-sensitive adhesive layer, the acrylic pressure-sensitive adhesive will be described in detail.

<Acrylic adhesive>

The acrylic adhesive contains an acrylic polymer as a base polymer. The acrylic adhesive may contain tackifying resin. The acrylic adhesive may contain the 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, tackifying resin, and crosslinking agent to the total amount of the acrylic pressure sensitive adhesive, the effect of the present invention can be expressed more , Preferably it is 95 weight% or more, More preferably, it is 97 weight% or more, More preferably, it is 99 weight% or more.

(Acrylic polymer)

As the acrylic polymer, for example, a polymer of a monomer component containing alkyl (meth)acrylate as a main monomer and further containing a secondary monomer having copolymerizability with the main monomer is preferable. Here, a main monomer means the component which occupies more than 50 weight% of the whole monomer component.

As the alkyl (meth)acrylate, for example, a compound represented by the following formula (1) can be suitably used.

CH ₂ =C(R ¹ )COOR ² (1)

^{Here, R 1} in the 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, the range of the number of carbon atoms may be expressed as “C1-20”). to be. 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, still more preferably a C4-8 chain alkyl group. Here, a chain|strand shape is a meaning including a linear shape and a branched shape.

Examples of the alkyl (meth) acrylate in which R ² is a C1-20 chain alkyl group include 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) acrylic rate, 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 (meth) acrylate, etc. can be heard The number of these alkyl (meth)acrylates may be one, and 2 or more types may be sufficient as them.

As an alkyl (meth)acrylate, from the point which can express the effect of this invention more, Preferably, n-butyl acrylate (BA) and 2-ethylhexyl acrylate (2EHA) are mentioned.

The content ratio of the alkyl (meth)acrylate to all the monomer components used for the synthesis of the acrylic polymer is preferably 70% by weight or more, and more preferably 85% by weight from the viewpoint of more expressing the effect of the present invention. It is weight % or more, More preferably, it is 90 weight% or more. The upper limit of the content rate of an alkyl (meth)acrylate becomes like this. Preferably it is 99.5 weight% or less, More preferably, it is 99 weight% or less. However, an acrylic polymer may be obtained by superposing|polymerizing only alkyl (meth)acrylate substantially.

R ² is a case of using a chain alkyl group of C4-8 alkyl (meth) acrylates, alkyl (meth) acrylate of R ² is a chain alkyl group of C4-8 alkyl (meth) acrylate contained in the monomer components The ratio is preferably 50% by weight or more, more preferably 70% by weight or more, still more preferably 90% by weight or more, and particularly preferably 95% by weight or more, from the viewpoint of further expressing the effect of the present invention. % by weight or more, and most preferably from 99% to 100% by weight.

As one embodiment of the acrylic polymer, an acrylic polymer in which 50% by weight or more of the total monomer component is n-butyl acrylate (BA) is exemplified. In this case, the content rate of n-butyl acrylate (BA) in all the monomer components is from the point which can express the effect of this invention more, Preferably it exceeds 50 weight% and is 100 weight% or less, More preferably Preferably it is 55 wt% to 95 wt%, more preferably 60 wt% to 90 wt%, particularly preferably 63 wt% to 85 wt%, and most preferably 65 wt% to 80 wt%. All the monomer components may further contain 2-ethylhexyl acrylate (2EHA) in a ratio smaller than n-butyl acrylate (BA).

As one embodiment of the acrylic polymer, an acrylic polymer in which less than 50% by weight of the total monomer component is 2-ethylhexyl acrylate (2EHA) is exemplified. 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, from the viewpoint that the effect of the present invention can be expressed more. It is preferably 5% to 45% by weight, more preferably 10% to 43% by weight, particularly preferably 15% to 40% by weight, and most preferably 20% to 35% by weight. . All the monomer components may further contain n-butyl acrylate (BA) in a ratio more than 2-ethylhexyl acrylate (2EHA).

Other monomers may be copolymerized with the acrylic polymer in the range which does not impair the effect of this invention. Other monomers can be used for purposes, such as adjustment of the glass transition temperature (Tg) of an acrylic polymer, adjustment of adhesive performance, etc., for example. For example, 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, etc., and vinyl esters are preferred. . Specific examples of vinyl esters include vinyl acetate (VAc), vinyl propionate, and vinyl laurate, with vinyl acetate (VAc) being preferred.

The number of "other monomers" may be one, and two or more types may be sufficient as them. The content of other monomers in the total monomer component is preferably 0.001 wt% to 40 wt%, more preferably 0.01 wt% to 40 wt%, still more preferably 0.1 wt% to 10 wt%, Especially preferably, it is 0.5 weight% - 5 weight%, Most preferably, it is 1 weight% - 3 weight%.

As other monomers capable of introducing a functional group serving as a crosslinking origin into the acrylic polymer or contributing to the improvement of adhesive strength, for example, a hydroxyl group (OH group)-containing monomer, a carboxyl group-containing monomer, an acid anhydride group-containing monomer, and an amide group A containing monomer, an amino group containing monomer, an imide group containing monomer, an epoxy group containing monomer, (meth)acryloylmorpholine, vinyl ethers, etc. are mentioned.

As one embodiment of an acrylic polymer, the acrylic polymer in which the carboxy group containing monomer was copolymerized as another monomer is mentioned. Examples of the carboxyl group-containing monomer include acrylic acid (AA), methacrylic acid (MAA), carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid and the like. Among these, since the effect of this invention can be expressed more, As a carboxy group-containing monomer, Preferably acrylic acid (AA) and methacrylic acid (MAA) are mentioned, More preferably, it is acrylic acid (AA). .

When a carboxyl group-containing monomer is employed as the other monomer, the content of the other monomer in the total monomer component is preferably 0.1% by weight to 10% by weight from the viewpoint of more expressing the effect of the present invention, more Preferably it is 0.2 wt% to 8 wt%, more preferably 0.5 wt% to 5 wt%, particularly preferably 0.7 wt% to 4 wt%, and most preferably 1 wt% to 3 wt% .

As one embodiment of an acrylic polymer, the acrylic polymer by which the hydroxyl-containing monomer was copolymerized as another monomer is mentioned. As a hydroxyl-containing monomer, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acryl are, for example. hydroxyalkyl (meth)acrylates such as lactate and 4-hydroxybutyl (meth)acrylate; polypropylene glycol mono (meth) acrylate; N-hydroxyethyl (meth)acrylamide; and the like. Among these, as a hydroxyl-containing monomer, from the point which can express the effect of this invention more, Preferably, a C2-C4 linear hydroxyalkyl (meth)acrylate is mentioned, Specifically, As examples, 2-hydroxyethyl acrylate (HEA) and 4-hydroxybutyl acrylate (4HBA) are mentioned, More preferably, it is 4-hydroxybutyl acrylate (4HBA).

When a hydroxyl-containing monomer is employed as the other monomer, the content of the other monomer in the total monomer component is preferably 0.001% by weight to 10% by weight, from the viewpoint of more expressing the effect of the present invention, more 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% to 0.5% by weight. .

Tg of the base polymer may be, for example, -80°C or higher from the viewpoint of further expressing the effect of the present invention. The base polymer (preferably an acrylic polymer) is designed so that Tg is preferably -15°C or less from the viewpoint of improving the deformability of the pressure-sensitive adhesive layer in the shear direction. In some embodiments, the Tg of the base polymer is, for example, preferably -25°C or less, more preferably -40°C or less, and still more preferably -50°C or less. The Tg of the base polymer is designed such 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 improving cohesiveness and shape restoration property. has been

The Tg of the base polymer is a value obtained from the formula of Fox based on the Tg of the homopolymer (homopolymer) of each monomer constituting the base polymer and the weight fraction (copolymerization ratio on a weight basis) of the monomer. say Fox's formula is a relational expression between Tg of the 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 Fox's formula, Tg is the glass transition temperature of the copolymer (unit: K), Wi is the weight fraction of the monomer i in the copolymer (copolymerization ratio based on weight), and Tgi is the homopolymer of the monomer i. The glass transition temperature (unit: K) is shown. As Tg of a homopolymer, it is assumed that the value described in well-known material is employ|adopted.

As Tg of a homopolymer, the following values can be used specifically, for example.

2-ethylhexyl acrylate -70℃

n-Butyl acrylate -55℃

Acrylic acid 106℃

2-hydroxyethyl acrylate -15℃

4-hydroxybutyl acrylate -40℃

For the homopolymer Tg other than those exemplified above, the numerical value described in "Polymer Handbook" (3rd ed., John Wiley & Sons, Inc., 1989) can be used. When a plurality of numerical values are described in the "Polymer Handbook", the conventional value is adopted. For monomers not described in the "Polymer Handbook", the catalog values of the monomer manufacturers are employed. As the homopolymer Tg of the monomer that is not described in the "Polymer Handbook" and the catalog value of the monomer manufacturer is not provided, a value obtained by the measurement method described in Japanese Patent Application Laid-Open No. 2007-51271 shall be used. .

As a method of obtaining an acrylic polymer, various polymerization methods known as a synthesis method of an acrylic polymer, such as a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, and a suspension polymerization method, can be employ|adopted suitably, for example. Among these polymerization methods, a solution polymerization method can be preferably used. As a monomer supply method at the time of solution polymerization, the batch input method which supplies the whole quantity of a monomer component at once, a continuous supply (dropping) system, a divided supply (dropping) system, etc. are employable suitably. The polymerization temperature can be appropriately selected according to the type of the monomer and solvent used, the type of the polymerization initiator, etc., and is preferably 20°C or higher, more preferably 30°C or higher, still more preferably 40°C or higher, and preferably Preferably it is 170 degrees C or less, More preferably, it is 160 degrees C or less, More preferably, it is 140 degrees C or less. As a method for obtaining an acrylic polymer, photopolymerization performed by irradiating light such as UV (typically performed in the presence of a photopolymerization initiator) or radiation polymerization performed by irradiating radiation such as β-ray or γ-ray with active energy rays You may employ|adopt irradiation polymerization.

As a solvent (polymerization solvent) used for solution polymerization, it can select suitably from arbitrary suitable organic solvents. For example, aromatic compounds, such as toluene (typically aromatic hydrocarbons), acetate esters, such as ethyl acetate, aliphatic or alicyclic hydrocarbons, such as hexane and cyclohexane, etc. are mentioned.

The initiator (polymerization initiator) used for polymerization can be suitably selected from arbitrary suitable polymerization initiators according to the kind of polymerization method. The number of polymerization initiators may be one, and 2 or more types may be sufficient as them. As such a polymerization initiator, For example, Azo type polymerization initiators, such as 2,2'- azobisisobutyronitrile (AIBN); persulfates such as potassium persulfate; peroxide-based initiators such as benzoyl peroxide and hydrogen peroxide; substituted ethane-based initiators such as phenyl-substituted ethane; aromatic carbonyl compounds; and the like. As another example of a polymerization initiator, the redox-type initiator by the combination of a peroxide and a reducing agent is mentioned.

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

Mw of the acrylic polymer is preferably 10×10 ⁴ to 500×10 ⁴ , more preferably 10×10 ⁴ to 150×10 ⁴ , further preferably 20×10 ⁴ to 75×10 ⁴ , Particularly preferably, it is 35×10 ⁴ to 65×10 ⁴ . Here, Mw means the value of standard polystyrene conversion obtained by GPC (gel permeation chromatography). As a GPC apparatus, model name "HLC-8320GPC" (column: TSKgel GMH-H(S), Tosoh Corporation make) can be used, for example.

(Tackifying resin)

The acrylic adhesive can contain tackifying resin at the point which can express the effect of this invention more. As tackifying resin, For example, rosin type tackifying resin, terpene type tackifying resin, hydrocarbon type tackifying resin, epoxy type tackifying resin, polyamide type tackifying resin, elastomer type tackifying resin, phenol type tackifying resin. , a ketone-based tackifying resin, and the like. One type may be sufficient as tackifying resin, and 2 or more types may be sufficient as it.

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 with respect to 100 parts by weight of the base polymer from the viewpoint that the effect of the present invention can be expressed more. parts, more preferably 15 parts by weight to 50 parts by weight, still more 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.

It is preferable that tackifying resin contains tackifying resin TL of less than 105 degreeC of softening point from the point which can express the effect of this invention more. Tackifying resin TL can contribute effectively to the improvement of the deformability to the surface direction (shear direction) of an adhesive layer. From the viewpoint of obtaining a higher deformability improving effect, 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, still more preferably 65 ℃ to 95 ℃, particularly preferably from 70 ℃ to 90 ℃, most preferably from 75 ℃ to 85 ℃.

The softening point of tackifying resin is defined as a value measured based on the softening point test method (round-ball method) prescribed|regulated to JISK5902 and JISK2207. Specifically, the sample is melted as quickly as possible at as low a temperature as possible, and the ring placed on a flat metal plate is filled with care so that no air bubbles are generated. After cooling, cut off the raised portion from the plane including the top of the ring with a slightly heated penknife. Next, a support device (annulus) is put 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 injected until it becomes 90 mm or more in depth. Next, the steel ball (diameter 9.5mm, weight 3.5g) and the ring filled with the sample are immersed in glycerin so as not to contact each other, and the temperature of the glycerin is maintained 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 supporter. Next, the distance from the upper end of the ring to the glycerin surface is maintained at 50 mm, a thermometer is placed, the central position of the mercury sphere of the thermometer is at the same height as the center of the ring, and the container is heated. The flame of the Bunsen burner used for heating should reach the center of the bottom of the container and the middle of the rim to make the heating even. In addition, 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 sample gradually softens and flows down from the ring, and the temperature when it finally comes into contact with the bottom plate is read, and this is the softening point. Two or more softening points are measured simultaneously, and the average value is employ|adopted.

As the usage-amount of tackifying resin TL, Preferably it is 5 weight part - 50 weight part with respect to 100 weight part of base polymers from the point which can express the effect of this invention more, More preferably, it is 10 weight part - 45 weight part It is a weight part, More preferably, it is 15 weight part - 40 weight part, Especially preferably, it is 20 weight part - 35 weight part, Most preferably, it is 25 weight part - 32 weight part.

As tackifying resin TL, the 1 type(s) or 2 or more types suitably selected from the thing of less than 105 degreeC of softening points among the tackifying resins illustrated above can be employ|adopted. Tackifying resin TL, Preferably a rosin-type resin is included.

As rosin-type resin which can be suitably employ|adopted as tackifying resin TL, rosin esters, such as unmodified rosin ester and modified rosin ester, etc. are mentioned, for example. As modified rosin ester, hydrogenated rosin ester is mentioned, for example.

Tackifying resin TL is a point which can express the effect of this invention more, Preferably hydrogenated rosin ester is included. As hydrogenated rosin ester, a softening point becomes from the point which can express the effect of this invention more, Preferably it is less than 105 degreeC, More preferably, it is 50 degreeC - 100 degreeC, More preferably, it is 60 degreeC - 90 degreeC and particularly preferably at 70°C to 85°C, and most preferably at 75°C to 85°C.

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

As the non-hydrogenated rosin ester, the softening point is 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 more expressed. °C, particularly preferably from 70 °C to 85 °C, and most preferably from 75 °C to 85 °C.

Tackifying resin TL may be added to rosin-type resin, and may contain other tackifying resin. As another tackifying resin, the 1 type(s) or 2 or more types suitably selected from the thing of less than 105 degreeC of softening points among the tackifying resins illustrated above can be employ|adopted. Tackifying resin TL may contain rosin-type resin and terpene resin, for example.

The content rate of the rosin-type resin to the whole tackifying resin TL is from the point which can express the effect of this invention more, Preferably it exceeds 50 weight%, More preferably, it is 55 weight% - 100 weight%, , more preferably 60 wt% to 99 wt%, particularly preferably 65 wt% to 97 wt%, and most preferably 75 wt% to 97 wt%.

Since the effect of the present invention can be more expressed, tackifying resin may contain a combination of tackifying resin TL and tackifying resin TH having a softening point of 105°C or higher (preferably 105°C to 170°C). do.

As tackifying resin TH, the 1 type(s) or 2 or more types suitably selected from the thing of a softening point 105 degreeC or more among the tackifying resins illustrated above can be employ|adopted. The tackifying resin TH may contain at least one selected from a rosin-based tackifying resin (eg, rosin esters) and a terpene-based tackifying resin (eg, a terpene phenol resin).

(crosslinking agent)

The acrylic pressure-sensitive adhesive may contain a crosslinking agent. The number of crosslinking agents may be one, and 2 or more types may be sufficient as them. By use of a crosslinking agent, moderate cohesive force can be provided to an acrylic adhesive. A crosslinking agent can also help control the shift|offset|difference distance and return distance in a holding force test. The acrylic adhesive containing a crosslinking agent can be obtained by forming an adhesive layer using the adhesive composition containing this crosslinking agent, for example. The crosslinking agent may be included in the acrylic pressure-sensitive adhesive in the form after the crosslinking reaction, in the form before the crosslinking reaction, in a partially crosslinked form, or in an intermediate or complex form thereof. A crosslinking agent is typically contained in the acrylic adhesive only in the form after a crosslinking reaction.

The amount of the crosslinking agent to be used is preferably 0.005 parts by weight to 10 parts by weight, more preferably 0.01 parts by weight to 7 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 expressed more. , more preferably 0.05 part by weight to 5 parts by weight, particularly preferably 0.1 part by weight to 4 parts by weight, and most preferably 1 part by weight to 3 parts by weight.

Examples of the crosslinking agent include isocyanate crosslinking agents, epoxy crosslinking agents, silicone crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, silane crosslinking agents, alkyletherified melamine crosslinking agents, metal chelate crosslinking agents, crosslinking agents such as peroxides, and the like. There is, and since the effect of this invention can be expressed more, Preferably it is an isocyanate type crosslinking agent and an epoxy type crosslinking agent, More preferably, it is an isocyanate type crosslinking agent.

As the isocyanate-based crosslinking 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 quantization or the like) can be used in one molecule. As an isocyanate type crosslinking agent, For example, aromatic isocyanate, such as tolylene diisocyanate and xylene diisocyanate; alicyclic isocyanates such as isophorone diisocyanate; aliphatic isocyanates such as hexamethylene diisocyanate; and the like.

As an isocyanate type crosslinking agent, More specifically, For example, Lower aliphatic polyisocyanate, such as butylene diisocyanate and hexamethylene diisocyanate; alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate and isophorone diisocyanate; aromatic diisocyanates such as 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, and polymethylene polyphenyl isocyanate; Trimethylolpropane/tolylene diisocyanate trimer adduct (For example, Tosoh Corporation, trade name Coronate L), Trimethylolpropane/hexamethylene diisocyanate trimer adduct (For example, Tosoh Corporation make, trade name: Coronate HL) ), isocyanate adducts such as isocyanurate compounds of hexamethylene diisocyanate (for example, Tosoh Corporation make, brand name: Coronate HX); Trimethylolpropane adduct of xylylene diisocyanate (for example, Mitsui Chemicals, trade name: Takenate D110N), and trimethylolpropane adduct of xylylene diisocyanate (for example, Mitsui Chemicals, trade name: Take) nate D120N), a trimethylolpropane adduct of isophorone diisocyanate (for example, Mitsui Chemical Co., Ltd., trade name: Takenate D140N), a trimethylolpropane adduct of hexamethylene diisocyanate (for example, manufactured by Mitsui Chemicals) , trade name: Takenate D160N); polyether polyisocyanates, polyester polyisocyanates, and adducts thereof with various polyols; polyisocyanates polyfunctionalized by an isocyanurate bond, a biuret bond, an allophanate bond, or the like; and the like. Among these, aromatic isocyanate and alicyclic isocyanate are preferable at the point which is compatible with deformability and cohesion force in good balance.

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

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

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

As the epoxy-based crosslinking agent, a polyfunctional epoxy compound having two or more epoxy groups in one molecule can be used. Examples of the epoxy-based crosslinking agent include N,N,N',N'-tetraglycidyl-m-xylenediamine, diglycidylaniline, and 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, poly Propylene glycol diglycidyl ether, sorbitol polyglycidyl ether, glycerol polyglycidyl ether, pentaerythritol 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, resorcinol diglycidyl ether, bisphenol- S-diglycidyl ether, an epoxy resin having two or more epoxy groups in the molecule, and the like. As a commercial item of an epoxy-type crosslinking agent, the Mitsubishi Gas Chemical company brand name "Tetrad C", "Tetrad X", etc. are mentioned, for example.

The amount of the epoxy-based crosslinking agent to be used is preferably 0.005 parts by weight to 10 parts by weight, more preferably 0.01 parts by weight to 5 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 more expressed. parts, more preferably 0.015 part by weight to 1 part by weight, particularly preferably 0.15 part by weight to 0.5 part by weight, and most preferably 0.015 part by weight to 0.3 part by weight.

(Other ingredients)

The acrylic pressure-sensitive adhesive may contain various additives common in the field of pressure-sensitive adhesives, such as leveling agents, crosslinking aids, plasticizers, softeners, fillers, antistatic agents, anti-aging agents, ultraviolet absorbers, antioxidants, and light stabilizers, if necessary. About these various additives, a conventionally well-known thing can be used by a conventional method.

≪Antistatic layer≫

The adhesive film of this invention may have an antistatic layer in the surface on the opposite side to the surface which has an adhesive layer of a base material layer. When the adhesive film of this invention has an antistatic layer on the surface on the opposite side to the surface which has an adhesive layer of a base material layer, it can suppress charging of adhesive film itself, it becomes difficult to adsorb|suck dust, It becomes a preferable aspect.

Examples of the antistatic layer include a method of applying an antistatic resin containing an antistatic agent and a resin component, a conductive polymer, and a conductive resin containing a conductive material, and a method of depositing or plating a conductive material.

As an antistatic agent contained in antistatic resin, For example, the cationic type antistatic agent which has cationic functional groups, such as a quaternary ammonium salt, a pyridinium salt, 1st, 2nd, 3rd amino group; anionic antistatic agents having anionic functional groups such as sulfonates, sulfate salts, phosphonates, and phosphate esters; positive antistatic agents such as alkylbetaine and derivatives thereof, imidazoline and derivatives thereof, alanine and derivatives thereof; Nonionic antistatic agents, such as amino alcohol and its derivative(s), glycerol and its derivative(s), polyethyleneglycol, and its derivative(s); an ion conductive polymer obtained by polymerizing or copolymerizing a monomer having an ion conductive group of the cation type, anionic type, or amphoteric ion type; and the like. The number of these antistatic agents may be one, and 2 or more types may be sufficient as them.

As the cationic antistatic agent, for example, having a quaternary ammonium group such as alkyltrimethylammonium salt, acyloylamidopropyltrimethylammonium methosulfate, alkylbenzylmethylammonium salt, choline acyl chloride, polydimethylaminoethyl methacrylate ( meth)acrylate copolymers; styrene copolymers having a quaternary ammonium group such as polyvinylbenzyltrimethylammonium chloride; diallylamine copolymers having a quaternary ammonium group such as polydiallyldimethylammonium chloride; and the like. The number of these antistatic agents may be one, and 2 or more types may be sufficient as them.

Examples of the anionic antistatic agent include alkylsulfonate, alkylbenzenesulfonate, alkylsulfate, alkylethoxysulfate, alkylphosphate, and sulfonic acid group-containing styrene copolymer. The number of these antistatic agents may be one, and 2 or more types may be sufficient as them.

Examples of the amphoteric antistatic agent include alkylbetaine, alkylimidazoliumbetaine, carbobetaine graft copolymerization, and the like. The number of these antistatic agents may be one, and 2 or more types may be sufficient as them.

Examples of the nonionic antistatic agent include fatty acid alkylolamide, di(2-hydroxyethyl)alkylamine, polyoxyethylene alkylamine, fatty acid glycerin ester, polyoxyethylene glycol fatty acid ester, sorbitan fatty acid ester, poly Oxysorbitan fatty acid ester, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ether, polyethylene glycol, polyoxyethylene diamine, copolymer containing polyether, polyester and polyamide, methoxy polyethylene glycol (meth) acrylate and the like. The number of these antistatic agents may be one, and 2 or more types may be sufficient as them.

Examples of the conductive polymer include polyaniline, polypyrrole, and polythiophene. The number of these conductive polymers may be one, and 2 or more types may be sufficient as them.

Examples of the conductive material include tin oxide, antimony oxide, indium oxide, cadmium oxide, titanium oxide, zinc oxide, indium, tin, antimony, gold, silver, copper, aluminum, nickel, chromium, titanium, iron, cobalt, iodide. and copper and their alloys or mixtures. The number of these electroconductive substances may be one, and 2 or more types may be sufficient as them.

As a resin component used for an antistatic resin and an electroconductive resin, general-purpose resins, such as a polyester resin, an acrylic resin, a polyvinyl resin, a urethane resin, a melamine resin, and an epoxy resin, are used, for example. In addition, in the case of a polymer type antistatic agent, it is not necessary to contain a resin component. In addition, as a component of the antistatic resin, as a crosslinking agent, a methylolated or alkylolated melamine-based compound, a urea-based compound, a glyoxal-based compound, and an acrylamide-based compound; epoxy compounds; isocyanate compounds; It is also possible to contain the like.

The antistatic layer is formed by, for example, diluting the above-described antistatic resin, conductive polymer, conductive resin, or the like with a solvent such as an organic solvent or water, applying this coating solution to a substrate or the like, and drying it.

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. The number of these solvents may be one, and 2 or more types may be sufficient as them.

As for the coating method in formation of an antistatic layer, arbitrary appropriate application|coating methods are used suitably. As such a coating method, roll coating, gravure coating, reverse coating, a roll brush, spray coating, air knife coating, impregnation, curtain coating etc. are mentioned, for example.

As a method of vapor deposition or plating of an electroconductive substance, any suitable method is used suitably. Examples of such a method include vacuum vapor deposition, sputtering, ion plating, chemical vapor deposition, spray thermal decomposition, chemical plating, and electroplating.

Any suitable thickness can be employ|adopted for the thickness of an antistatic layer in the range which does not impair the effect of this invention. Since the effect of this invention can be expressed more, the thickness of an antistatic layer becomes like this. Preferably it is 0.001 micrometer - 5 micrometers, More preferably, they are 0.005 micrometer - 1 micrometer.

≪Top coating layer≫

The adhesive film of this invention may have a topcoat layer in the surface on the opposite side to the surface which has an adhesive layer of a base material layer. The top coating layer preferably contains a binder, and more preferably contains a binder and a lubricant. When the adhesive film of this invention has a top coating layer, the scratch resistance of an adhesive film improves, and it becomes a preferable aspect.

<Binder>

As the binder, any suitable resin may be employed within a range not impairing the effects of the present invention. As such resin, it is the point which can express the effect of this invention more, Preferably it is at least 1 sort(s) chosen from the group containing a polyester resin and a urethane resin.

(polyester resin)

When a polyester resin is contained in a binder, only 1 type may be sufficient as this polyester resin, and 2 or more types may be sufficient as it.

The polyester resin is preferably a resin containing polyester as a main component. The content rate of polyester in a polyester resin becomes like this. Preferably it is more than 50 weight%, More preferably, it is 75 weight% or more, More preferably, it is 90 weight% or more.

The polyester is preferably selected from polyhydric carboxylic acids having two or more carboxyl groups in one molecule (preferably dicarboxylic acids) and derivatives thereof (anhydrides, esters, halides, etc. of polyhydric carboxylic acids) At least one compound (polyhydric carboxylic acid component) that is used is condensed with at least one compound (polyhydric alcohol component) selected from polyhydric alcohols (preferably diols) having two or more hydroxyl groups in one molecule has one structure.

Examples of the compound that can be employed as the polyhydric carboxylic acid component include oxalic acid, malonic acid, difluoromalonic acid, alkylmalonic acid, succinic acid, tetrafluorosuccinic acid, alkylsuccinic acid, (±)-malic acid, and meso-tartaric acid. , itaconic acid, maleic acid, methyl maleic acid, fumaric acid, methyl fumaric acid, acetylenedicarboxylic acid, glutaric acid, hexafluoroglutaric acid, methylglutaric acid, glutaconic acid, adipic acid, dithioadipic acid , methyl adipic acid, dimethyl adipic acid, tetramethyl adipic acid, methylene adipic acid, muconic acid, galactaric acid, pimelic acid, suberic acid, perfluorosuberic acid, 3,3,6,6 -aliphatic dicarboxylic acids such as tetramethylsuberic acid, azelaic acid, sebacic acid, perfluorosebacic acid, brassylic acid, dodecyldicarboxylic acid, tridecyldicarboxylic acid, and tetradecyldicarboxylic acid; cycloalkyldicarboxylic acid (eg, 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid), 1,4-(2-norbornene)dicarboxylic acid, alicyclic dicarboxylic acids such as 5-norbornene-2,3-dicarboxylic acid (hymic acid), adamantane dicarboxylic acid, and spiroheptane dicarboxylic acid; Phthalic acid, isophthalic acid, dithioisophthalic acid, methylisophthalic acid, dimethylisophthalic acid, chloroisophthalic acid, dichloroisophthalic acid, terephthalic acid, methylterephthalic acid, dimethylterephthalic acid, chloroterephthalic acid, bromoterephthalic acid, naphthalenedicarboxylic acid, Leric acid, anthracenedicarboxylic acid, biphenyldicarboxylic acid, biphenylenedicarboxylic acid, dimethylbiphenylenedicarboxylic acid, 4,4"-p-terephenylenedicarboxylic acid, 4 ,4"-p-quaterphenyldicarboxylic acid, bibenzyldicarboxylic acid, azobenzenedicarboxylic acid, homophthalic acid, phenylene diacetic acid, phenylenedipropionic acid, naphthalenedicarboxylic acid, naphthalenedipropionic acid, biphenyl Diacetic acid, biphenyldipropionic acid, 3,3'-[4,4'-(methylenedi-p-biphenylene)dipropionic acid, 4,4'-bibenzyldiacetic acid, 3,3'(4,4) aromatic dicarboxylic acids such as '-bibenzyl) dipropionic acid and oxydi-p-phenylene diacetic acid; acid anhydride of any one of the above-mentioned polyhydric carboxylic acids; esters of any one of the above-mentioned polyhydric carboxylic acids (eg, alkyl esters, monoesters, diesters, etc.); acid halides corresponding to any of the above-mentioned polyvalent carboxylic acids (eg, dicarboxylic acid chloride, etc.); and the like.

As a preferable example of the compound which can be employ|adopted as a polyhydric carboxylic acid component, Aromatic dicarboxylic acids, such as terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid, and its acid anhydride; aliphatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, succinic acid, fumaric acid, maleic acid, hymic acid, and 1,4-cyclohexanedicarboxylic acid and acid anhydrides thereof; lower alkyl esters of the above dicarboxylic acids (eg, esters with monoalcohols having 1 to 3 carbon atoms); and the like.

Examples of the compound that can be employed 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, Diols such as 3-propanediol, 2,2-diethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, xylylene glycol, hydrogenated bisphenol A, and bisphenol A can be heard As another example, the alkylene oxide adduct (For example, an ethylene oxide adduct, a propylene oxide adduct, etc.) of these compounds is mentioned.

The polyester resin preferably contains water-dispersible polyester, and more preferably contains water-dispersible polyester as a main component. Such water-dispersible polyester is, for example, a polyester with improved water dispersibility by introducing a hydrophilic functional group (for example, at least one selected from hydrophilic functional groups such as sulfonic acid metal base, carboxyl group, ether group, and phosphoric acid group) in the polymer. can As such, 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, a polyhydric carboxylic acid component, a polyhydric alcohol component, an oligomer thereof, etc.) ) to generate a hydrophilic functional group, any suitable method may be appropriately employed. As preferable water-dispersible polyester, the polyester (copolymerization polyester) in which the compound which has a hydrophilic functional group was copolymerized is mentioned.

The polyester resin used as a binder may have saturated polyester as a main component, and may have unsaturated polyester as a main component. The polyester resin is preferably a saturated polyester as its main component, and more preferably a saturated polyester (eg, saturated copolyester) to which water dispersibility is imparted. Such a polyester resin (a polyester resin which may be prepared in the form of an aqueous dispersion) can be synthesized by any suitable method, or a commercial item can be easily obtained.

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

When a urethane-type resin is contained in a binder, 1 type may be sufficient as this urethane-type resin, and 2 or more types may be sufficient as it.

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

As a polyol (A), only 1 type may be sufficient and 2 or more types may be sufficient as it.

As the polyol (A), any appropriate polyol can be employed as long as it is a polyol having two or more OH groups. Examples of the polyol (A) include a polyol having two OH groups (diol), a polyol having three OH groups (triol), a polyol having four OH groups (tetraol), and a polyol having five OH groups (penta ol), a polyol having 6 OH groups (hexanol), and the like.

As polyol (A), Preferably, glycols, such as ethylene glycol and propylene glycol which have two or more OH groups, are employ|adopted as an essential component. When glycol is employed as an essential component in this way, for example, it is possible to provide a urethane-based cured resin that is excellent in the strength of the coating film after curing, and is excellent in adhesion to a substrate and retention of an additive material. The content of glycol in the polyol (A) is preferably 30% by weight to 100% by weight, more preferably 50% by weight to 100% by weight, still more preferably 70% by weight to 100% by weight, More preferably, it is 90% by weight to 100% by weight, particularly preferably 95% by weight to 100% by weight, and 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- Nonanediol, 2-methyl-1,8-octanediol, 1,8-decanediol, octadecanediol, glycerin, trimethylolpropane, pentaerythritol, hexanetriol, polyethylene glycol, polypropylene glycol, polyester polyol, Polyether polyol, polycaprolactone polyol, polycarbonate polyol, a castor oil-type polyol, etc. are mentioned.

As a polyester polyol, it can obtain by the esterification reaction of a polyol component and an acid component, for example.

Examples of the acid component include succinic acid, methylsuccinic acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, 1,12-dodecanoic acid, 1,14-tetradecanoic 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, these acid anhydrides, etc. are mentioned.

Examples of the polyether polyol include water, low molecular weight polyols (propylene glycol, ethylene glycol, glycerin, trimethylolpropane, pentaerythritol, etc.), bisphenols (bisphenol A, etc.), dihydroxybenzene (catechol, resorcin, polyether polyol obtained by addition polymerization of alkylene oxides, such as ethylene oxide, propylene oxide, and a butylene oxide, using hydroquinone etc.) etc. as an initiator. Specifically, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc. are mentioned, for example.

Examples of the polycaprolactone polyol include caprolactone-based polyesterdiol obtained by ring-opening polymerization of cyclic ester monomers such as ε-caprolactone and σ-valerolactone.

As polycarbonate polyol, For example, polycarbonate polyol obtained by making the said polyol component and phosgene polycondensate; The polyol component and dicarbonate such as dimethyl carbonate, diethyl carbonate, dipropyl carbonate, diisopropyl carbonate, dibutyl carbonate, ethylbutyl carbonate, ethylene carbonate, propylene carbonate, diphenyl carbonate, and dibenzyl carbonate polycarbonate polyols obtained by transesterifying esters; Copolymerization polycarbonate polyol obtained by using together 2 or more types of said polyol component; polycarbonate polyols obtained by esterifying the various polycarbonate polyols with a carboxyl group-containing compound; polycarbonate polyols obtained by etherifying the above various polycarbonate polyols with a hydroxyl group-containing compound; a polycarbonate polyol obtained by transesterifying the various polycarbonate polyols with an ester compound; polycarbonate polyols obtained by transesterifying the various polycarbonate polyols with a hydroxyl group-containing compound; polyester-based polycarbonate polyols obtained by polycondensation reaction of the various polycarbonate polyols and dicarboxylic acid compounds; copolymerized polyether-based polycarbonate polyols obtained by copolymerizing the above various polycarbonate polyols and alkylene oxides; and the like.

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

The number of polyfunctional isocyanate compounds (B) may be one, and 2 or more types may be sufficient as them.

As the polyfunctional isocyanate compound (B), any appropriate polyfunctional isocyanate compound that can be used in the urethanation reaction can be employed. As such a polyfunctional isocyanate compound (B), a polyfunctional aliphatic type isocyanate compound, polyfunctional alicyclic type isocyanate, a polyfunctional aromatic type isocyanate compound, etc. are mentioned, for example.

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, etc. are 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. and hydrogenated xylylene diisocyanate, 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, and 4,4'-diphenyl Methane diisocyanate, 4,4'-toluidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, xylylene diisocyanate, etc. are mentioned. have.

As a polyfunctional isocyanate compound (B), the trimethylol propane adduct body of the above various polyfunctional isocyanate compounds, the biuret body which reacted with water, the trimer etc. which have an isocyanurate ring are mentioned. Moreover, you may use these together.

The content of the polyfunctional isocyanate compound (B) is preferably 5 to 60% by weight, and more preferably 8 to 60% by weight of the polyfunctional isocyanate compound (B) to the polyol (A). %, and more preferably 10 wt% to 60 wt%. By adjusting the content rate of a polyfunctional isocyanate compound (B) within the said range, the effect of this invention can be expressed further.

The urethane-based 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) can be included in the range not impairing the effects of the present invention. Examples of such other components include catalysts, resin components other than polyurethane-based resins, tackifiers, inorganic fillers, organic fillers, metal powders, pigments, thin materials, softeners, plasticizers, antioxidants, conductive agents, antioxidants , a ultraviolet absorber, a light stabilizer, a surface lubricant, a leveling agent, a corrosion inhibitor, a heat-resistant stabilizer, a polymerization inhibitor, a lubricant, a solvent, and the like.

As a method of obtaining a urethane-based resin by curing a composition containing a polyol (A) and a polyfunctional isocyanate compound (B), a urethanation reaction method using bulk polymerization or solution polymerization, etc. In the range that does not impair the effects of the present invention Any suitable method may be employed.

(Other resins)

As long as the top coating layer does not significantly impair the performance of the adhesive film, as a binder, other resins than polyester resins and urethane resins (eg, acrylic resins, acrylic-styrene resins, acrylic-silicone resins, silicone resins) , at least one resin selected from polysilazane resin, fluororesin, and polyolefin resin) may be further contained. As a preferred embodiment of the top coating layer, the binder of the top coating layer substantially contains at least one selected from the group consisting of a polyester resin and a urethane-based resin, and selected from the group containing a polyester resin and a urethane-based resin occupying the binder The proportion of at least one type used is preferably 98% by weight to 100% by weight, more preferably 99% by weight to 100% by weight, and still more preferably 99.5% by weight to 100% by weight. The proportion of the binder in the entire topcoat layer is preferably 15 wt% to 95 wt%, and more preferably 25 wt% to 80 wt%.

<Lubrication>

As a lubricant, it is preferable to contain the ester of a higher fatty acid and a higher alcohol (it may call a "wax ester" hereafter.).

A "higher fatty acid" is preferably a carboxylic acid having 8 or more carbon atoms, more preferably 10 or more, and still more preferably 10 to 40 carbon atoms. The carboxylic acid is preferably monovalent carboxylic acid.

The "higher alcohol" is preferably an alcohol having 6 or more carbon atoms, more preferably 10 or more, and still more preferably 10 to 40. Alcohol, Preferably it is monohydric or dihydric alcohol, More preferably, it is monohydric alcohol.

The top coating layer having a composition comprising a combination of such a wax ester and the above-mentioned binder is difficult to whiten even when maintained in a high temperature and high humidity condition. Therefore, the adhesive film provided with the base material which has such a top coating layer can become a thing with higher appearance quality.

As the reason why excellent whitening resistance (for example, the property that whitening is difficult even if maintained under high temperature and high humidity conditions) is realized by the top coating layer having the above composition, for example, the following reasons are considered. That is, it is estimated that the silicone-based lubricant used conventionally exhibits the function of imparting slipperiness to the surface of the top coating layer by bleeding. However, in these silicone lubricants, the degree of bleed tends to fluctuate depending on the difference in storage conditions (temperature, humidity, time-lapse, etc.). For this reason, for example, when hold|maintained by normal storage conditions (for example, 25 degreeC, 50%RH), moderate slipperiness over a comparatively long period (for example, about 3 months) from immediately after manufacture of an adhesive film. If the usage-amount of a silicone type lubricant is set so that this may be obtained, when this adhesive film is stored for 2 weeks on high temperature and high humidity conditions (for example, 60 degreeC, 95%RH), the bleed|bleeding of a lubricant will advance excessively. The silicone lubricant that bleeds excessively in this way may cause whitening of the top coating layer (and furthermore, the adhesive film).

As a preferred embodiment of the top coating layer, a specific combination of a wax ester as a lubricant and a polyester resin as a binder is employed. According to the combination of the lubricant and the binder, the degree of bleed of the wax ester from the top coating layer is hardly affected by the storage conditions. Thereby, the whitening resistance of an adhesive film can be improved.

As the wax ester, one or more of the compounds represented by the general formula (W) can be preferably employed.

X-COO-Y (W)

X and Y in formula (W) are each independently, Preferably it is a C10-40 hydrocarbon group, The number of carbon atoms becomes like this. More preferably, it is 10-35, More preferably, it is 14-35. and particularly preferably 20 to 32. When the number of carbon atoms is too small, there is a fear that the effect of imparting slidability to the top coating layer is insufficient. A saturated hydrocarbon group may be sufficient as said hydrocarbon group, and an unsaturated hydrocarbon group may be sufficient as it. The hydrocarbon group is preferably a saturated hydrocarbon group. In addition, the above hydrocarbon group may have a structure containing an aromatic ring, a structure not containing an aromatic ring (aliphatic hydrocarbon group), or a hydrocarbon group having a structure containing an aliphatic ring (alicyclic hydrocarbon group). or a chain (including linear and branched) hydrocarbon groups.

As a wax ester, X and Y in Formula (W) are each independently a compound, Preferably it is a C10-40 linear alkyl group, More preferably, it is a C10-40 straight-chain compound. It is a compound that is an alkyl group. Specific examples of such a compound include, for example, myrisyl serotate (CH ₃ (CH ₂ ) ₂₄ COO(CH ₂ ) ₂₉ CH ₃ ), myrisyl 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 ), etc. can

The wax ester has a melting point of preferably 50°C or higher, more preferably 60°C or higher, still more preferably 70°C or higher, and particularly preferably 75°C or higher. With this wax ester, higher whitening resistance can be realized. It is preferable that melting|fusing point of wax ester is 100 degrees C or less. Such wax esters have a high effect of imparting slidability, so that a top coating layer with higher scratch resistance can be formed. It is preferable that melting|fusing point of a wax ester is 100 degrees C or less, also from the point that it is easy to prepare the aqueous dispersion of a wax ester. As such a wax ester, for example, myrisyl cetoate can be preferably employed.

As a raw material for the top coating layer, a natural wax containing such a wax ester can be used. As such a natural wax, the content ratio of the wax esters (the sum of the content ratios when two or more types of wax esters are included) on a non-volatile matter (NV) basis is preferably more than 50% by weight, more preferably Preferably it is 65 weight% or more, More preferably, it is 75 weight% or more. As such a natural wax, for example, carnauba wax (generally, myrisyl serotic acid is included in a proportion of 60% by weight or more, more preferably 70% by weight or more, still more preferably 80% by weight or more. ), vegetable waxes such as palm wax; animal waxes such as beeswax and spermaceti; and the like. The melting point of such natural wax is preferably 50°C or higher, more preferably 60°C or higher, still more preferably 70°C or higher, and particularly preferably 75°C or higher. As a raw material for the top coating layer, a chemically synthesized wax ester may be used, or a wax ester obtained by refining natural wax to increase the purity of the wax ester may be used. The number of these raw materials may be one, and 2 or more types may be sufficient as them.

The proportion of the lubricant to the entire topcoat layer is preferably 5% by weight to 50% by weight, and more preferably 10% by weight to 40% by weight. When there is too little content rate of a lubricant, there exists a possibility that scratch resistance may fall easily. When there is too much content rate of a lubricant, there exists a possibility that the improvement effect of whitening resistance may become insufficient easily.

The top coating layer may contain another lubricant in addition to the wax ester. Examples of other lubricants include petroleum waxes (paraffin wax, etc.), mineral waxes (montan wax, etc.), higher fatty acids (cerotic acid, etc.), triglycerides (palmitic acid triglyceride, etc.) other than wax esters. waxes. Moreover, in addition to the wax ester, you may make it contain a silicone type lubricant, a fluorine type lubricant, etc. A preferred embodiment of the top coating layer is a form substantially free of silicone lubricants and fluorine-based lubricants. For example, the total content of the silicone lubricant and fluorine-based lubricant is preferably 0.01 wt% or less of the entire top coating layer, and more preferably is below the detection limit.

The top coating layer is, if necessary, an antistatic component, a crosslinking agent, an antioxidant, a colorant (pigment, dye, etc.), a fluidity modifier (thixotropic agent, thickener, etc.), a film forming aid, a surfactant (antifoaming agent, dispersing agent, etc.), preservative, etc. may contain additives.

<Antistatic component of top coating layer>

A preferred embodiment of the top coating layer contains an antistatic component. As an antistatic component, it is a component which can exhibit the effect|action which prevents or suppresses charging of an adhesive film. When the top coating layer contains an antistatic component, for example, an organic or inorganic conductive substance, various antistatic agents, and the like can be used as the antistatic component. It is also possible to use an antistatic agent that can be used in the antistatic layer described above.

As an organic electroconductive substance, Cationic type antistatic agent which has cationic functional groups, such as a quaternary ammonium salt, a pyridinium salt, a 1st amino group, a 2nd amino group, and a 3rd amino group; anionic antistatic agents having anionic functional groups such as sulfonates, sulfate salts, phosphonates, and phosphoric acid ester salts; zwitterionic antistatic agents such as alkylbetaine and derivatives thereof, imidazoline and derivatives thereof, alanine and derivatives thereof; Nonionic antistatic agents, such as amino alcohol and its derivative(s), glycerol and its derivative(s), polyethyleneglycol, and its derivative(s); an ion conductive polymer obtained by polymerizing or copolymerizing a monomer having an ion conductive group (eg, a quaternary ammonium base) of the cation type, anionic type, or amphoteric ion type; conductive polymers such as polythiophene, polyaniline, polypyrrole, polyethyleneimine, and allylamine polymers; and the like. The number of such antistatic agents may be one, and 2 or more types may be sufficient as them.

Examples of the inorganic conductive material include 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, ITO (indium oxide/tin oxide), ATO (antimony oxide/tin oxide), etc. are mentioned. One type may be sufficient as such an inorganic conductive substance, and 2 or more types may be sufficient as it.

Examples of the antistatic agent include cationic antistatic agents, anionic antistatic agents, zwitterionic antistatic agents, nonionic antistatic agents, ions obtained by polymerizing or copolymerizing a monomer having an ion conductive group of the above cationic, anionic, and zwitterionic types. A conductive polymer, etc. are mentioned.

When the top coating layer contains an antistatic component, preferably, the antistatic component contains an organic conductive material. As the organic conductive material, various conductive polymers can be preferably used. According to such a structure, favorable antistatic property and high scratch resistance can be made compatible.

Examples of the conductive polymer include polythiophene, polyaniline, polypyrrole, polyethyleneimine, and allylamine polymer. The number of such conductive polymers may be one, and two or more types may be sufficient as them. Moreover, you may use in combination with other antistatic components (inorganic electroconductive substance, antistatic agent, 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, still more preferably 3 parts by weight, based on 100 parts by weight of the binder contained in the top coating layer. to 50 parts by weight. When there is too little usage-amount of a conductive polymer, there exists a possibility that the antistatic effect may become small. When the amount of the conductive polymer used is too large, the compatibility of the conductive polymer in the top coating layer becomes insufficient, and there is a fear that the appearance quality of the top coating layer may decrease or solvent resistance may decrease.

As a conductive polymer, Preferably, polythiophene and polyaniline are mentioned. As the polythiophene, and the weight average molecular weight Mw in terms of polystyrene, preferably from 40 × 10 ⁴ or less, more preferably 30 × 10 ⁴ or less. As a polyaniline, and the weight average molecular weight Mw in terms of polystyrene, preferably from 50 × 10 ⁴ or less, more preferably 30 × 10 ⁴ or less. The weight average molecular weight Mw in terms of polystyrene of the conductive polymer is preferably 0.1×10 ⁴ or more, and more preferably 0.5×10 ⁴ or more. In addition, in this specification, polythiophene means the polymer of unsubstituted or substituted thiophene. Examples of the substituted thiophene polymer include poly(3,4-ethylenedioxythiophene) and the like.

As a method for forming the top coating layer, when a method of applying and adhering a coating material for forming the top coating layer to a substrate and drying or curing is adopted, as a conductive polymer used for preparing the coating material, the conductive polymer is dissolved or dispersed in water. One type of thing (a conductive polymer aqueous solution) can be preferably used. Such a conductive polymer aqueous solution can be prepared, for example, by dissolving or dispersing in water 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 a molecule) in water. Examples of the hydrophilic functional group include a sulfo group, an amino group, an amide group, an imino group, a hydroxyl group, a mercapto group, a hydrazino group, a carboxyl group, a quaternary ammonium group, a sulfuric acid ester group (-O-SO ₃ H), a phosphate ester group (eg For example, -O-PO(OH) ₂ ) etc. are mentioned. Such a hydrophilic functional group may form a salt. As a commercial item of polythiophene aqueous solution, the brand name "Denatron" series by the Nagase Chemtech company, etc. are mentioned, for example. As a commercial item of polyaniline sulfonic acid aqueous solution, the brand name "aqua-PASS" by Mitsubishi Rayon Corporation etc. is mentioned, for example.

In preparation of a coating material, Preferably, polythiophene aqueous solution is used. As the polythiophene aqueous solution, a polythiophene aqueous solution containing polystyrene sulfonate (PSS) (for example, a form in which PSS is added to polythiophene as a dopant) is preferable. The polythiophene aqueous solution may contain polythiophene: PSS, preferably in a mass ratio of 1:1 to 1:10. The total content of polythiophene and PSS in this aqueous polythiophene solution is preferably 1% by mass to 5% by weight. As a commercial item of such polythiophene aqueous solution, the brand name of H.C. Stark company "Baytron" etc. are mentioned, for example. In addition, when using the polythiophene aqueous solution containing PSS as described above, the total amount of polythiophene and PSS is preferably 5 to 200 parts by weight, more preferably 5 to 200 parts by weight, based on 100 parts by weight of the binder. is 10 parts by weight to 100 parts by weight, more preferably 25 parts by weight to 70 parts by weight.

The top coating layer may contain both a conductive polymer and one or more other antistatic components (an organic conductive substance other than a conductive polymer, an inorganic conductive substance, an antistatic agent, etc.) as needed. Preferably, the top coating layer contains substantially no antistatic component other than the conductive polymer. That is, it is preferable that the antistatic component contained in the top coating layer consists substantially only of a conductive polymer.

<crosslinking agent>

The top coating layer preferably contains a crosslinking agent. As the crosslinking agent, a crosslinking agent such as a melamine-based crosslinking agent, an isocyanate-based crosslinking agent, and an epoxy-based crosslinking agent used for crosslinking of general resins can be appropriately selected and used. By using such a crosslinking agent, at least one of the effects of improvement of scratch resistance, improvement of solvent resistance, improvement of print adhesion, and reduction of friction coefficient (that is, improvement of slidability) can be realized. Preferably, the crosslinking agent comprises a melamine-based crosslinking agent. The crosslinking agent may be a top coating layer consisting substantially only of a melamine-based crosslinking agent (melamine-based resin) (that is, substantially free of a crosslinking agent other than a melamine-based crosslinking agent).

<One preferred form of top coating layer>

One preferred embodiment of the top coating layer is that when the material of the base layer is at least one selected from polyimide and polyether ether ketone, the top coating layer contains a binder containing a urethane-based resin and an antistatic component. In this way, by employing a binder containing a urethane-based resin as the binder of the antistatic component of the top coating layer, the top coating layer is coated on the surface of the base material layer using at least one material selected from polyimide and polyether ether ketone. It becomes excellent in property, and while an external appearance can become a thing favorable, the outstanding antistatic property can be expressed.

As the binder of the antistatic component of the top coating layer, a binder containing a polyester resin is preferred in many cases, but for a specific substrate layer in which the material of the substrate layer is at least one selected from polyimide and polyether ether ketone, poly The affinity of the binder containing an ester resin may be low, and there exists a possibility that the external appearance after application|coating formation of a top coating layer may worsen, and there exists a possibility that the outstanding antistatic property may not be expressed. As described above, when the material of the base layer is at least one selected from polyimide and polyether ether ketone, when the top coating layer contains a binder including a urethane-based resin and an antistatic component, the surface of the base layer The coating formability of the top coating layer to a furnace becomes excellent, and an external appearance can be made favorable, and the outstanding antistatic property can be expressed.

<Formation of Top Coating Layer>

The top coating layer can be suitably formed by a method comprising applying to a substrate a liquid composition (coating material for forming a top coating layer) in which the resin component and optionally used additives are dispersed or dissolved in a suitable solvent. For example, a method in which the coating material is applied to the first surface of the substrate, dried, and optionally cured (heat treatment, ultraviolet treatment, etc.) is preferably employed. The NV (non-volatile content) of the coating material is preferably 5% by weight or less, more preferably 0.05% by weight to 5% by weight, still more preferably 0.05% by weight to 1% by weight, particularly preferably 0.10% by weight. % to 1% by weight. In the case of forming the top coating layer having a small thickness, the NV of the coating material is preferably 0.05 wt% to 0.50 wt%, and more preferably 0.10 wt% to 0.30 wt%. By using such a low NV coating material, a more uniform top coating layer can be formed.

The solvent constituting the coating material for forming the top coating layer is preferably one capable of stably dissolving or dispersing the component for forming the top coating layer. 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 hydrocarbons such as n-hexane and cyclohexane; aromatic hydrocarbons such as toluene and xylene; aliphatic or alicyclic alcohols such as methanol, ethanol, n-propanol, isopropanol and cyclohexanol; glycol ethers such as alkylene glycol monoalkyl ether (eg, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether) and dialkylene glycol monoalkyl ether; At least 1 type selected from etc. is mentioned. Preferably, the solvent constituting the coating material for forming the top coating layer is water or a mixed solvent containing water as a main component (eg, a mixed solvent of water and ethanol).

<Properties of top coating layer>

The thickness of the top coating layer is preferably 3 nm to 500 nm, more preferably 3 nm to 100 nm, still more preferably 3 nm to 60 nm. When the thickness of the topcoat layer is too large, there exists a possibility that transparency (light transmittance) of an adhesion film may fall easily. If the thickness of the top coating layer is too small, it may be difficult to form the top coating layer uniformly. There exists a possibility that it may become easy to generate|occur|produce nonuniformity in the external appearance.

The thickness of the top coating layer can be determined by observing the cross section of the top coating layer with a transmission electron microscope (TEM). For example, a target sample (a substrate having a top coating layer, an adhesive film having a substrate, etc.) is subjected to heavy metal dyeing treatment for the purpose of clarifying the top coating layer, followed by resin embedding, and ultra-thin sectioning method Thus, the result obtained by performing TEM observation of the sample cross section can be preferably employed as the thickness of the top coating layer. As TEM, TEM (model "H-7650") by Hitachi Corporation etc. can be used, for example. In the examples to be described later, after performing binarization processing on a cross-sectional image obtained under the conditions of acceleration voltage: 100 kV and magnification: 60,000 times, the thickness of the top coating layer (within the field of view) is divided by the cross-sectional area of the top coating by the sample length within the field of view. average thickness). In addition, in the case where the top coating layer can be observed sufficiently clearly even without heavy metal dyeing, the heavy metal dyeing treatment may be omitted. Alternatively, a calibration curve is prepared for the correlation between the thickness detected by TEM and the detection result by various thickness detection devices (eg, surface roughness meter, interferometric thickness meter, infrared spectrometer, various X-ray diffraction apparatus, etc.) The thickness of the top coating layer may be obtained by performing calculations.

The surface resistivity measured on the surface of the top coating layer is preferably 10 ¹² Ω or less, more preferably 10 ⁴ Ω to 10 ¹² Ω, still more preferably 10 ⁴ Ω to 10 ¹¹ Ω, particularly preferably is 5×10 ⁴ Ω to 10 ¹⁰ Ω, most preferably 10 ⁴ Ω to 10 ⁹ Ω. The adhesive film exhibiting such a surface resistivity can be suitably used as an adhesive film used in the process or conveyance process of articles which do not like static electricity, such as a liquid crystal cell or a semiconductor device, etc. The value of the surface resistivity is computable from the value of the surface resistance measured in 23 degreeC and 50 %RH atmosphere using the commercially available insulation resistance measuring apparatus.

The coefficient of friction of the top coating layer is preferably 0.4 or less. When a top coating layer with such a low coefficient of friction is used, when a load (such as a load that causes scratches) is applied to the top coating layer, the load is transferred along the surface of the top coating layer, and the frictional force caused by the load can be reduced. . As a result, cohesive failure of the top coating layer (damage mode in which the top coating layer breaks inside) or interfacial failure (damage mode in which the top coating layer peels off from the back surface of the substrate) is less likely to occur. Accordingly, it is possible to further prevent the occurrence of scratches on the pressure-sensitive adhesive film. The lower limit of the friction coefficient is preferably 0.1 or more, more preferably 0.15 or more, in consideration of the balance with other characteristics (eg, appearance quality, printability, etc.). As the coefficient of friction, for example, a value obtained by rubbing the surface of the top coating layer with a vertical load of 40 mN under a measurement environment of 23° C. and 50% RH can be adopted. What is necessary is just to set the usage-amount of a lubricant so that a desirable coefficient of friction may be implement|achieved. It is also effective to increase the crosslinking density of the top coating layer by, for example, addition of a crosslinking agent or adjustment of film-forming conditions for adjusting the friction coefficient.

It is preferable that the adhesive film has the property that the back surface (the surface of a top coating layer) can print easily with an oil-based ink (for example, using an oil-based marking pen). In such an adhesive film, in the process of processing or conveying an adherend (for example, an optical component) performed in a state in which the adhesive film is affixed, the identification number of the to-be-protected adherend is described on the adhesive film suitable for displaying Therefore, a surface protection film excellent in printing properties by adding to the appearance quality is preferable. For example, it is preferable that the solvent is alcohol-based and has high printability with respect to an oil-based ink of a type containing a pigment. Further, it is preferable that the printed ink is less likely to come off due to friction or electrodeposition (that is, excellent print adhesion). It is preferable that the pressure-sensitive adhesive film has solvent resistance to a degree that does not cause a noticeable change in appearance even when the printing is corrected or erased with alcohol (eg, ethyl alcohol).

Since the top coating layer preferably contains a wax ester as a lubricant, a new peeling treatment (for example, any suitable peeling treatment agent such as a silicone-based release agent or a long-chain alkyl-based release agent is applied to the surface of the top coating layer, followed by drying ), sufficient sliding properties (for example, the above-described preferred coefficient of friction) can be realized even in an embodiment in which the slidability is not implemented. This embodiment in which the surface of the top coating layer is not subjected to a new peeling treatment is preferable from the viewpoint of being able to prevent in advance whitening caused by the peeling agent (for example, whitening caused by storage under heating and humidification conditions). Do. Moreover, it is advantageous also from the point of solvent resistance.

The pressure-sensitive adhesive film, in addition to the base material, the pressure-sensitive adhesive layer and the top coating layer, may also be implemented in an embodiment including another layer. Examples of the arrangement of such "other layers" include between the first surface (rear surface) and the top coating layer of the substrate, and between the second surface (front surface) and the pressure-sensitive adhesive layer of the substrate. The layer disposed between the back surface of the substrate and the top coating layer may be, for example, a layer including an antistatic component (antistatic layer). The layer disposed between the front surface of the substrate and the pressure-sensitive adhesive layer may be, for example, an undercoating layer (anchor layer), an antistatic layer, or the like, which enhances anchoring properties of the pressure-sensitive adhesive layer to the second surface. An antistatic layer is disposed on the front surface of the substrate, an anchor layer is disposed on the antistatic layer, and an adhesive film having a configuration in which an adhesive layer is disposed thereon may be used.

≪≪Foldable devices and rollable devices≫≫

Since the adhesive film of the present invention is excellent in flexibility and transparency, for example, a bendable device (a device capable of bending), a foldable device (a device capable of folding), or a rollable device (a device capable of being rounded) having a movable bending portion device) may be suitably provided. Since the adhesive film of the present invention is particularly excellent in flexibility and transparency, it can be suitably provided in a foldable device (a device capable of folding) or a rollable device (a device capable of being rounded), which has been more difficult to apply so far.

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 members as long as the adhesive film of the present invention is provided.

The rollable device of this invention is equipped with the adhesive film of this invention. As long as the rollable device of this invention is equipped with the adhesive film of this invention, it may contain arbitrary appropriate other members.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic sectional drawing which shows one Embodiment of the foldable device of this invention as a representative example of one use form of the adhesive film of this invention. In FIG. 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 , and an adhesive layer 60 . , the OLED 70 and the adhesive film 100 of the present invention are provided. The adhesive film 100 of this invention is comprised from the adhesive layer 80 and the 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 are. The adhesive layer containing the adhesive of the same composition as the adhesive layer 80 which comprises the adhesive film 100 of this invention may be sufficient, or the adhesive layer containing the adhesive of a different composition may be sufficient.

Since the adhesive film of the present invention is excellent in flexibility and transparency, for example, a bendable device (a device that can be bent), a foldable device (a device that can be folded), or a rollable device (which can be rounded) having a movable bending portion The device) may be suitably provided on the rear surface (the surface opposite to the display surface). Fig. 1 is a diagram of a foldable device (foldable device) provided on the rear surface (the surface opposite to the display surface).

Example

Hereinafter, an Example and a comparative example are given and this invention is demonstrated more concretely. However, this invention is not limited to them at all. In addition, in the following description, "part" and "%" are based on weight, unless there is special notice.

<tanδ>

With a viscoelasticity measuring apparatus "RSA-G2" (manufactured by TA Instruments Japan Co., Ltd.), measurement was performed in a tensile mode with a sample size of 5 mm in width x 15 mm in distance and 100 g of axial force. In the strain oscillation amplitude mode, a frequency of 1 Hz, a measurement temperature of 90° C., an immersion time of 60 seconds, and a measurement area of the strain were set from 0.01% to 1.0%, and measurements were made in the strain in between. The value of tan δ at each strain was graphed, and the tan δ of strain of 0.1% and strain of 0.7% was obtained from the graph. Regarding the thickness, the stiffness of the substrate is large for both the storage modulus and the loss modulus with respect to the adhesive film, and the influence of the adhesive is negligible, and only the thickness of the substrate excluding the thickness of the adhesive was input and measured.

tanδ was calculated|required by the following formula.

tanδ = loss modulus/storage modulus

<Bending Test>

As shown in FIG. 2, the pressure-sensitive adhesive film in a flat state is fixed in a state where the pressure-sensitive adhesive film is bent at 6 Φ with the pressure-sensitive adhesive layer side facing outward, sandwiched between the silicone-treated surface of the silicone-treated separator, and fixed at 90° C. for 48 hours kept. After that, the bending was released and left to stand at 23°C and 50% RH for 24 hours, then the angle of the bent film was measured. The case where it was completely restored to the original state was 180 degrees, and the case where the bent state in the initial fixation was maintained as it was was made into 0 degrees.

<Peel evaluation>

The adhesive film was bonded to a PET film (made by Toray, S10) having a thickness of 50 μm, and the adhesive film was bent so that the adhesive film was inside as shown in FIG. 3 , and maintained at 90° C. for 48 hours, then the fixed state It was released and the peeling of the adhesive film from this PET film was visually observed. Evaluation was performed according to the following criteria.

(circle): Peeling from a PET film is not seen.

x: Peeling from a PET film is seen.

<Measurement of haze and total light transmittance>

Using a haze meter HM-150 (manufactured by Murakami Shikisai Kijutsu Genkyujo Co., Ltd.), in accordance with JIS-K-7136, haze (%) = (Td/Tt) x 100 (Td: diffuse transmittance, Tt: total light transmittance). In addition, the total light transmittance was measured based on JIS-K-7316.

<Young's modulus>

A sample piece was cut into a rectangle with a width of 10 mm, and the rectangular sample piece was stretched in the long side direction at a distance between chucks of 100 mm with a universal tensile compression tester (Tensilon) under a temperature environment of 25 ° C. -Strength) The Young's modulus was obtained from the curve. As the measurement conditions, the tensile speed was 200 mm/min and the chuck interval was 50 mm. In the method of obtaining the Young's modulus from the S-S curve, a graph of the S-S curve was prepared, a tangent line (linear equation) was drawn on the graph in a displacement range of 1 mm to 2 mm, and it was obtained from the slope of the tangent line.

<Adhesiveness>

The adhesion film was cut|disconnected by width 25mm and length 150mm, and it was set as the 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 affixed to a glass plate (Matsunami Glass Kogyo Co., Ltd., trade name: Microslide Glass S) by one reciprocation of a 2.0 kg roller. . After curing for 30 minutes in an atmosphere of a temperature of 23° C. and a humidity of 50% RH, peeling was performed at a peeling angle of 180 degrees and a tensile rate of 300 mm/min using a universal tensile tester (Minebea Corporation, product name: TCM-1kNB). and the adhesive force was measured.

<Applicability>

The number of non-uniformities generated in a circular shape in the applied top coating layer (containing antistatic layer) is counted. Two sheets were prepared in A4 size, and the average number was calculated.

2 or less were judged as good, and 3 or more were judged as bad. The circular non-uniformity part was a part where the thickness of the top coating layer became thin, and it became a defect as an external appearance, and the antistatic agent was repelled and the thing which could not apply|coat at all was set as "cratering".

<Surface resistance value (for Example 8)>

In Example 8, the layer on which the antistatic treatment layer was formed was measured with a volume ohmmeter Model 152-1 152P-2P probe (manufactured by Trek Japan Co., Ltd.) at a voltage of 10 V.

<Surface resistivity (for Examples 9 to 17 and Comparative Examples 6 to 9>

In Examples 9 to 17 and Comparative Examples 6 to 9, using a resistivity meter (manufactured by Mitsubishi Chemical Analytech, "Hirestar UP MCP-HT450 type"), the URS probe was brought into contact with the non-laid surface of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive film. Then, the surface resistivity was measured under the conditions of an applied voltage of 100 V and a voltage application time of 10 seconds.

[Production Example 1]: Preparation of the pressure-sensitive 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-hydroxy acrylic acid Ethyl (HEA): 13 parts by weight, 2,2'-azobisisobutyronitrile as a polymerization initiator: 0.2 parts by weight, and ethyl acetate as a polymerization solvent: 133 parts by weight were put into a separable flask, and nitrogen gas was introduced while introducing Stirred for 1 hour. After removing oxygen in the polymerization system in this way, the temperature was raised to 65°C and reacted 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.

Next, in the solution of the acrylic polymer (a1), an isocyanate-based crosslinking agent (trade name "Takenate D110N", manufactured by Mitsui Chemicals Co., Ltd.) is added to the solution of the acrylic polymer (a) (solid content) by 1 weight part in terms of solid content with respect to 100 parts by weight of the acrylic polymer (a) (solid content) It added as much as possible, and the adhesive composition A was prepared.

[Production Example 2]: Preparation of the pressure-sensitive adhesive composition B

In a 4-neck flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a cooler, 96.2 parts by weight of 2-ethylhexyl acrylate (2EHA), 3.8 parts by weight of hydroxyethyl acrylate (HEA), 2,2 as a polymerization initiator '- 0.2 parts by weight of azobisisobutyronitrile and 150 parts by weight of ethyl acetate were added, nitrogen gas was introduced while gently stirring, and the liquid temperature in the flask was maintained at around 60 ° C. and polymerization reaction was performed for 6 hours, an acrylic polymer ( A solution (40% by weight) of b) was prepared. The weight average molecular weight of the acrylic polymer (b) was 540,000.

Next, the solution (40% by weight) of the acrylic polymer (b) is diluted to 25% by weight with ethyl acetate, and hexamethylene diisocyanate which is a trifunctional isocyanate compound as a crosslinking agent is added to 400 parts by weight of this solution (100 parts by weight of solid content) as a crosslinking agent. 4 parts by weight of isocyanurate (Tosoh Corporation, Coronate HX) 4 parts by weight (solid content 4 parts by weight), dioctyl tin dilaurate as a crosslinking catalyst (Tokyo Fine Chemicals, Envirizer OL-1, 1% by weight ethyl acetate solution) 2 weight part (0.02 weight part of solid content) and 3 weight part of acetylacetone were added, mixing stirring was performed, and the adhesive composition B was prepared.

[Example 1]

A commercially available release liner (Diafoil MRF-38, manufactured by Mitsubishi Juicy Co., Ltd.) was prepared. The adhesive composition A was apply|coated so that the thickness after drying might be set to 25 micrometers on one surface (release surface) of a release liner, and it was made to dry at 130 degreeC for 3 minutes. In this way, the 25-micrometer-thick adhesive layer comprised with the acrylic adhesive A corresponding to the adhesive composition A was formed on the peeling surface of the peeling liner.

As the substrate layer, a polyimide-based substrate having a thickness of 50 μm (trade name “Kapton”, manufactured by Toray DuPont Co., Ltd.) was prepared. The adhesive layer formed on the said release liner was bonded to one side of this base material layer. The release liner was left on the pressure-sensitive adhesive layer as it was, and was used for protecting the surface (adhesive layer surface) of the pressure-sensitive adhesive layer. The obtained structure was passed through a laminator (0.3 MPa, speed 0.5 m/min) at 80°C once, and then aged in an oven at 50°C for 1 day. In this way, the adhesion film (1) was obtained.

The results are shown in Table 1.

[Example 2]

As a base material layer, it carried out similarly to Example 1 except having used the 50-micrometer-thick polyimide-type base material (trade name "Upilex-50S", the Ube Kosan Co., Ltd. make), and the adhesive film (2) was obtained.

The results are shown in Table 1.

[Example 3]

As a base material layer, it carried out similarly to Example 1 except having used the 50-micrometer-thick polyimide-type base material (trade name "Pixio BP", Kaneka Co., Ltd. make), and the adhesive film 3 was obtained.

The results are shown in Table 1.

[Example 4]

As a base material layer, it carried out similarly to Example 1, except having used the 50-micrometer-thick polyimide-type base material (trade name "Upilex-50RN", the Ube Kosan Co., Ltd. make), and the adhesive film (4) was obtained.

The results are shown in Table 1.

[Example 5]

Example 1, except that a 50 µm-thick polyether ether ketone (PEEK)-based substrate (trade name: “Shin-Etsu Sepla Film,” unstretched high crystal, Shin-Etsu Polymers Co., Ltd.) was used as the substrate layer. It carried out similarly, and obtained the adhesion film (5).

The results are shown in Table 1.

[Example 6]

As a base material layer, it carried out similarly to Example 1, except having used the 50-micrometer-thick polyimide-type base material (trade name "Neo-Annealing S100", Mitsubishi Gas Chemical Co., Ltd. make), and the adhesive film 6 was obtained.

The results are shown in Table 1.

[Example 7]

As a base material layer, it carried out similarly to Example 1 except having used the 25-micrometer-thick polyether ether ketone (PEEK) base material (brand name "Xpeak", made by Kurabo), and the adhesive film 7 was obtained.

The results are shown in Table 1.

[Comparative Example 1]

As a base material layer, it carried out similarly to Example 1 except having used the 25-micrometer-thick polyester base material (trade name "Lumirer S10", manufactured by Toray) to obtain an adhesion film (C1).

The results are shown in Table 1.

[Comparative Example 2]

As a base material layer, it carried out similarly to Example 1 except having used the 50-micrometer-thick polyester base material (brand name "Lumirer S10", Toray make), and obtained the adhesion film (C2).

The results are shown in Table 1.

[Comparative Example 3]

The pressure-sensitive adhesive composition B was used instead of the pressure-sensitive adhesive composition A, and as a base layer, a polyester base material having a thickness of 50 µm (trade name "Lumirer S10", manufactured by Toray) was used in the same manner as in Example 1, except that the adhesive film ( C3) was obtained.

The results are shown in Table 1.

[Comparative Example 4]

Except having used the adhesive composition B instead of the adhesive composition A, it carried out similarly to Example 6, and obtained the adhesive film (C4).

The results are shown in Table 1.

[Comparative Example 5]

Except having used the adhesive composition B instead of the adhesive composition A, it carried out similarly to Example 7, and obtained the adhesive film (C5).

The results are shown in Table 1.

[Production Example 3]: Preparation of antistatic treatment polyimide film A

An antistatic agent solution was prepared by diluting 10 parts by weight of an antistatic agent (manufactured by Solvex, Microsolver RMd-142, tin oxide and polyester resin as main components) with a mixed solvent consisting of 30 parts by weight of water and 70 parts by weight of methanol. The obtained antistatic agent solution was applied on a 50 μm-thick polyimide-based substrate (trade name: “Kapton”, manufactured by Toray DuPont Co., Ltd.) as a substrate using a Mayer bar, and the solvent was removed by drying at 130° C. for 1 minute. , an antistatic layer (thickness: 0.2 µm) was formed to prepare an antistatic treatment polyimide film A.

[Example 8]

Except having used the antistatic treatment polyimide film A as a base material, it carried out similarly to Example 1, and obtained the adhesion film (8). The surface resistance value was 5×10 ⁶ Ω.

[Production Example 4]: Preparation of top coating layer-forming polyimide film B

<Preparation of coating material B>

A dispersion containing 25% by weight of a polyester resin (binder) as a binder (manufactured by Toyobo Corporation, trade name "Binaroll MD-1480" (aqueous dispersion of saturated copolymerized polyester resin); hereinafter also referred to as "binder dispersion" .) was prepared.

In addition, as a lubricant, an aqueous dispersion (hereinafter also referred to as "lubricating agent dispersion") of carnauba wax (manufactured by Nippon Wax, trade name "refined carnauba wax No. 2 powder") was prepared.

In addition, as a conductive polymer, an aqueous solution containing 0.5 wt% of poly(3,4-dioxythiophene) (PEDOT) and 0.8 wt% of polystyrene sulfonate (number average molecular weight 150,000) (PSS) (manufactured by HCStark, 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 50:50), 100 parts by weight of the binder dispersion liquid, 30 parts by weight of the lubricant dispersion, and 50 parts by weight of the conductive polymer aqueous solution by solid content And, 7 parts by weight of a melamine-based crosslinking agent was added, stirred for about 20 minutes, and thoroughly mixed. In this way, a coating material B having an NV of about 0.15% by weight was prepared.

<Preparation of polyimide film B with top coating layer>

The coating material B was applied and attached with a bar coater on a 50 µm-thick polyimide-based substrate (trade name: “Kapton”, manufactured by Toray DuPont, Ltd.), which is a substrate, and dried by heating at 130° C. for 2 minutes. In this way, a base material (a polyimide film with a top coat layer B) having a transparent top coat layer having a thickness of 10 nm on one side of the polyimide base material was produced.

[Production Example 5]: Preparation of polyimide film C with top coating layer

<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 neopentyl 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") was prepared.

In addition, as a lubricant, an aqueous dispersion (hereinafter also referred to as "lubricating agent dispersion") of carnauba wax (manufactured by Nippon Wax, trade name "refined carnauba wax No. 2 powder") was prepared.

In addition, an aqueous solution containing 0.5 wt% of poly(3,4-dioxythiophene) (PEDOT) and 0.8 wt% of polystyrene sulfonate (number average molecular weight 150,000) (PSS) (manufactured by HCStark, as a conductive polymer) trade name "Baytron P"; hereinafter also referred to as "conductive polymer aqueous solution") was prepared.

In addition, an aqueous solution containing 10% by weight of polyethylene glycol (PEG)alkyl ether and 10% by weight of polyvinyl alcohol was prepared as a dispersing agent.

In a mixed solvent of water and ethanol (weight ratio 50:50), 40 parts by weight of the binder dispersion, 5 parts by weight of the lubricant dispersion, and 8 parts by weight of the conductive polymer aqueous solution by solids , 40 parts by weight of the dispersant and 7 parts by weight of a melamine-based crosslinking agent were added, stirred for about 20 minutes, and mixed sufficiently. In this way, a coating material C having an NV of about 0.30% by weight was prepared.

<Preparation of polyimide film C with top coating layer>

On a polyimide-based substrate (trade name: “Kapton”, manufactured by Toray DuPont, Co., Ltd.) having a thickness of 50 μm as a substrate, the coating material C was applied and attached with a bar coater, and dried by heating at 130° C. for 2 minutes. In this way, a base material (a polyimide film with a top coat layer C) having a transparent top coat layer having a thickness of 50 nm on one side of the polyimide base material was produced.

[Example 9]

Except having used the polyimide film B with a top coating layer as a base material, it carried out similarly to Example 1, and obtained the adhesion film (9).

The results are shown in Table 2.

[Example 10]

Except having used the polyimide film B with a top coating layer as a base material, it carried out similarly to Example 2, and obtained the adhesion film 10.

The results are shown in Table 2.

[Example 11]

Except having used the polyimide film B with a top coating layer as a base material, it carried out similarly to Example 4, and obtained the adhesion film 11.

The results are shown in Table 2.

[Example 12]

Except having used the polyimide film B with a top coating layer as a base material, it carried out similarly to Example 7, and obtained the adhesion film 12.

The results are shown in Table 2.

[Example 13]

Except having used the polyimide film C with a top coating layer as a base material, it carried out similarly to Example 1, and obtained the adhesion film 13.

The results are shown in Table 2.

[Example 14]

Except having used the polyimide film C with a top coating layer as a base material, it carried out similarly to Example 2, and obtained the adhesion film 14.

The results are shown in Table 2.

[Example 15]

Except having used the polyimide film C with a top coating layer as a base material, it carried out similarly to Example 3, and obtained the adhesion film 15.

The results are shown in Table 2.

[Example 16]

Except having used the polyimide film C with a top coating layer as a base material, it carried out similarly to Example 4, and obtained the adhesion film 16.

The results are shown in Table 2.

[Example 17]

Except having used the polyimide film C with a top coating layer as a base material, it carried out similarly to Example 7, and obtained the adhesion film 17.

The results are shown in Table 2.

[Comparative Example 6]

Except having used the polyimide film B with a top coating layer as a base material, it carried out similarly to the comparative example 1, and obtained the adhesion film (C6).

The results are shown in Table 2.

[Comparative Example 7]

Except having used the polyimide film B with a top coating layer as a base material, it carried out similarly to the comparative example 2, and obtained the adhesion film (C7).

The results are shown in Table 2.

[Comparative Example 8]

Except having used the polyimide film C with a top coating layer as a base material, it carried out similarly to the comparative example 1, and obtained the adhesion film (C8).

The results are shown in Table 2.

[Comparative Example 9]

Except having used the polyimide film C with a top coating layer as a base material, it carried out similarly to the comparative example 2, and obtained the adhesion film (C9).

The results are shown in Table 2.

Since the adhesive film of the present invention is excellent in flexibility and transparency, for example, a bendable device (a device that can be bent), a foldable device (a device that can be folded), or a rollable device (which can be rounded) having a movable bending portion device) may be suitably provided.

1000: foldable device
100: adhesive film
10: cover film
20: adhesive layer
30: polarizer
40: adhesive layer
50: touch sensor
60: adhesive layer
70: OLED
80: adhesive layer
90: base layer
1: 6Φ glass rod
2: Silicon-treated separator
3: adhesive layer
4: fixed glass
5: PET film

Claims (20)

It is an adhesive film having a base 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. It is an adhesive film having a base layer and an adhesive layer,
The difference between tanδ (0.7%) at 0.7% strain and tanδ (0.1%) at strain 0.1% (tanδ(0.7%)-tanδ(0.1%)) measured in the tensile mode of the viscoelasticity measuring device is 0.05 or less ,
adhesive film. The bending angle according to claim 1 or 2, wherein the bending angle is 60 to 180 degrees after bending at 6 Φ and holding at 90° C. for 48 hours, releasing the bending and leaving it to stand at 23° C. and 50% RH for 24 hours, adhesive film. The pressure-sensitive adhesive film according to any one of claims 1 to 3, wherein the substrate layer has a top coating layer on the surface on the opposite side to the surface having the pressure-sensitive adhesive layer. The adhesive film according to claim 4, wherein the top coating layer contains a binder comprising at least one selected from a polyester resin and a urethane-based resin. The adhesive film according to claim 5, wherein the binder comprises a urethane-based resin. The adhesive film according to any one of claims 4 to 6, wherein the top coating layer contains an antistatic component. The pressure-sensitive adhesive film according to any one of claims 1 to 7, 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 layer is at least one selected from polyimide and polyether ether ketone. The base material layer according to any one of claims 1 to 3, wherein a top coating layer is provided on a surface opposite to the pressure-sensitive adhesive layer-bearing surface, and the top coating layer contains a binder containing a urethane-based resin and an antistatic component. And, the material of the base layer is at least one selected from polyimide and polyether ether ketone, the adhesive film. The adhesive film in any one of Claims 1-10 whose total light transmittance is 20 % or more. The adhesive film in any one of Claims 1-11 whose haze is 15 % or less. The pressure-sensitive adhesive film according to any one of claims 1 to 12, wherein the pressure-sensitive adhesive layer has an adhesive force of 1N/25mm or more to the SUS plate at a tensile rate of 300 mm/min and a 180-degree peel at 23°C. The pressure-sensitive adhesive film according to any one of claims 1 to 13, wherein the pressure-sensitive adhesive layer comprises an acrylic pressure-sensitive adhesive. The adhesive film according to any one of claims 1 to 14, which is affixed to the 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 affixed to a rollable member. The adhesive film according to claim 17, wherein the rollable member is an OLED. A foldable device comprising the adhesive film according to any one of claims 1 to 14. A rollable device provided with the adhesive film in any one of Claims 1-14.

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