TWI688634B - Adhesive sheets and optical components - Google Patents

Abstract

The present invention provides an adhesive sheet capable of improving antistatic properties and pick-up properties, and an optical member protected by the adhesive sheet. The adhesive sheet of the present invention is characterized by sequentially having a first resin layer, an adhesive layer, a second resin layer, and an adhesive layer formed of an adhesive composition, and the thickness of the adhesive layer is relative to the thickness of the first resin layer The ratio of the thickness to the sum of the thickness of the second resin layer is 0.50 or less, the storage elastic modulus of the adhesive layer at 23° C. is 1.0×10 ⁴ Pa or more and less than 5.0×10 ⁷ Pa, the first resin layer The surface opposite to the surface with the adhesive layer has a topcoat layer consisting of polyaniline sulfonic acid as a conductive polymer component, polyester resin as a binder component and crosslinking In the case of a composition for a top coat of an isocyanate compound of an agent, the above-mentioned adhesive composition contains an organic polysiloxane having an oxyalkylene chain.

Description

Adhesive sheets and optical components

The invention relates to an adhesive sheet and an optical member.

The adhesive sheet of the present invention is used as a polarizing plate, a wavelength plate, a retardation plate, an optical compensation film, a reflective sheet, a brightness enhancement film used in protecting a liquid crystal display, an organic EL (electroluminescence) display, a touch panel display, etc. , Cover glass, cover sheet, hard coating film, transparent conductive glass, transparent conductive film and other surface protection film used for the purpose of the optical member surface is more useful.

In recent years, when transporting optical parts or electronic parts or mounting them on a printed circuit board, each part is transferred in a state of being packaged with a specific sheet or in a state where an adhesive tape is attached. Among them, surface protection films are particularly widely used in the fields of optical and electronic parts.

The surface protective film is generally attached to the adherend via an adhesive applied to the support film side, and is used for the purpose of preventing scratches or stains generated during the processing and transportation of the adherend (Patent Document 1). For example, a panel of a liquid crystal display is formed by bonding an optical member such as a polarizing plate or a wavelength plate to a liquid crystal cell via an adhesive. These optical components are attached with a surface protective film via an adhesive to prevent scratches or stains generated during processing and transportation of the adherend.

Then, the optical member is attached to the liquid crystal cell, etc., and then the protective film is peeled off and removed when the protective film is no longer needed. Generally speaking, the protective film or optical member is made of plastic material, so it has high electrical insulation and generates static electricity when rubbed or peeled off. because Therefore, static electricity is also generated when the protective film is peeled off from an optical member such as a polarizing plate. If a voltage is applied to the liquid crystal in a state where static electricity remains, the alignment loss of the liquid crystal molecules or the defect of the panel may occur. In addition, the presence of static electricity may also cause dust absorption or reduce workability. In view of the above, carry out anti-static treatment on the surface protective film, for example, by forming an anti-static layer or applying an anti-static coating layer as the surface layer (top coat layer, back layer) of the surface protective film to give the anti-static function (Refer to Patent Documents 2 and 3).

In addition, in recent years, PEDOT (poly(3,4-ethylenedioxythiophene))/PSS (polystyrene sulfonic acid) has been used as a conductive polymer to impart an antistatic function to the surface layer of the surface protective film Salt) (polythiophene type) of the water-dispersed type. However, when the above-mentioned conductive polymer is used to form an antistatic layer, as time passes, PSS (equivalent to dopant) is detached from PEDOT, resulting in an increase in surface resistivity or peeling electrostatic voltage, etc., and There may be problems such as an increase (deterioration) in surface resistivity accompanying oxidative degradation or photo degradation.

In addition, if an increase (deterioration) in surface resistivity or the like occurs, static electricity is generated when the surface protective film is peeled off from the adherend, which may cause problems.

In addition, the surface protection film is peeled off and removed at a stage when it is no longer needed, but as the liquid crystal display panel becomes larger or thinner, damage to the polarizing plate or liquid crystal cell is likely to occur during the peeling step. It does not cause moderate adhesion such as warping, and requires light releasability, pick-up, etc. to enable re-peelability. In particular, in recent years, along with the thinning of the display, the optical members constituting the display have also become thinner. For optical members having a thickness of 150 μm or less and a thinner 100 μm or less, the optical member deflects during the transport step, and thus cannot be transported. In addition, there is also a problem that the optical member cannot be completely bonded to other members. In order to avoid these problems, thickening the surface protective film to suppress deflection, but due to the thickening and peeling becomes heavy, so when the surface protective film is no longer needed when the surface protective film is peeled off by the pick-up tape, it cannot be picked up Bad condition. Therefore, there is a demand for an adhesive sheet that can suppress deflection and achieve light peelability and pick-up properties so that it can be peeled off again. material.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2003-334911

[Patent Document 2] Japanese Patent Laid-Open No. 2000-26817

[Patent Document 3] Japanese Patent Laid-Open No. 2008-255332

Therefore, the present invention has been extensively and intensively studied in consideration of the above-mentioned matters, and as a result, an adhesive sheet capable of improving antistatic properties and pick-up properties, and an optical member protected by the adhesive sheet are provided.

That is, the adhesive sheet of the present invention is characterized by sequentially having a first resin layer, an adhesive layer, a second resin layer, and an adhesive layer formed of an adhesive composition, the thickness of the adhesive layer relative to the first resin The ratio of the thickness of the layer to the sum of the thickness of the second resin layer is 0.50 or less. The storage elastic modulus of the adhesive layer at 23° C. is 1.0×10 ⁴ Pa or more and less than 5.0×10 ⁷ Pa. The first The surface of the resin layer opposite to the surface with the adhesive layer has a top coat, the top coat consists of a polyaniline sulfonic acid as a conductive polymer component, a polyester resin as an adhesive component and In the case of forming a composition for a top coat of an isocyanate-based compound of a cross-linking agent, the above-mentioned adhesive composition contains an organic polysiloxane having an oxyalkylene chain.

In the adhesive sheet of the present invention, it is preferable that the above composition for top coat further contains fatty amide as a lubricant.

In the adhesive sheet of the present invention, it is preferable that at least one of the resin layers is a polyester film.

In the adhesive sheet of the present invention, it is preferable that the adhesive composition contains acrylic Adhesives and/or carbamate adhesives.

In the adhesive sheet of the present invention, the adhesive composition preferably contains an antistatic component.

The optical member of the present invention is preferably protected by the above-mentioned adhesive sheet.

The adhesive sheet according to the present invention has a resin layer film (the order of the first resin layer, the adhesive layer, and the second resin layer. The order of the first resin layer, the adhesive layer, and the second resin layer. The deformation when the adhesive sheet peels off, the stress is relieved at the part of the adhesive layer, and it can be picked up with a peeling force (adhesive force) lower than that of the individual resin layer. In addition, with the above-mentioned build-up structure, the deflection of the laminated film can be improved compared with the deflection of each resin layer film (reduction of the deflection), and the problem of poor transport due to breakage or deformation in the transport step can be improved , Can achieve the improvement of manufacturing efficiency. In addition, since the resin layer film has a top coat layer containing a specific raw material on one side and an adhesive layer containing a specific raw material on the other side, an adhesive sheet with excellent antistatic properties or excellent pick-up properties can be obtained. kind.

1‧‧‧adhesive sheet (surface protective film)

1A‧‧‧Coated surface

2‧‧‧ Polarizer

3‧‧‧Acrylic resin board

4‧‧‧Fixed

5‧‧‧potentiometer

6‧‧‧First resin layer

7‧‧‧Next layer

8‧‧‧Second resin layer

12‧‧‧Resin film (first resin layer+adhesive layer+second resin layer)

14‧‧‧Top coating

20‧‧‧Adhesive layer

20A‧‧‧adhesive surface

50‧‧‧plane polarizer

60‧‧‧Single-sided adhesive tape

62‧‧‧Adhesive layer (adhesive surface)

64‧‧‧Substrate

130‧‧‧ Double-sided adhesive tape

132‧‧‧Stainless steel plate

160‧‧‧Single-sided adhesive tape

162‧‧‧Acrylic adhesive (adhesive layer)

162A‧‧‧adhesive surface

164‧‧‧Resin film (first resin layer+adhesive layer+second resin layer)

G‧‧‧Glass plate

H‧‧‧ Height from the center

L‧‧‧load

T‧‧‧No.31B tape

FIG. 1 is a schematic cross-sectional view of a protective film according to a preferred embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating a measurement method of peeling electrostatic voltage.

FIG. 3 is an explanatory diagram illustrating the measurement method of the back surface adhesive force (A).

4 is an explanatory diagram illustrating a peeling method of an adhesive sheet according to an embodiment.

Fig. 5 is an explanatory diagram illustrating a method of measuring the amount of deflection.

Hereinafter, the embodiments of the present invention will be described in detail.

<adhesive sheet (surface protective film)>

FIG. 1 is a schematic cross-sectional view of an adhesive sheet according to a preferred embodiment of the present invention. The adhesive sheet 1 has a first resin layer 6, an adhesive layer 7, and a second resin layer 8 in this order (sometimes, a structure having the first resin layer, adhesive layer, and second resin layer in this order is called a “resin layer Membrane'') and The adhesive layer 20 and the surface of the first resin layer 6 opposite to the surface having the adhesive layer 20 have a top coat layer 14. The above-mentioned adhesive sheet 1 is a layered body in which the first resin layer 6 and the second resin layer 8 are laminated via the adhesive layer 7 and has an adhesive layer 20 and a top coat layer 14. In addition, the adhesive layer 20 is bonded to the adherend (for example, an optical member). In addition, although not shown, it is preferable that a separator is bonded to the surface of the adhesive layer 20 before bonding to the adherend.

<resin layer>

(第二樹脂層之厚度)，此時第一樹脂層之厚度較佳為1μm~50μm，更佳為4μm~38μm，最佳為10μm~25μm。另外，第二樹脂層之厚度較佳為10μm~200μm，更佳為25μm~130μm，最佳為38μm~75μm。若於上述範圍內，則可兼顧黏著片材之撓曲量抑制與拾取性，為較佳之態樣。 The resin layer is preferably composed of a resin film. The thickness of the resin layer is preferably 1 μm to 200 μm, and more preferably 12 μm to 75 μm. The relationship between the thickness of the first resin layer and the thickness of the second resin layer is preferably (thickness of the first resin layer)

(Thickness of the second resin layer) At this time, the thickness of the first resin layer is preferably 1 μm to 50 μm, more preferably 4 μm to 38 μm, and most preferably 10 μm to 25 μm. In addition, the thickness of the second resin layer is preferably 10 μm to 200 μm, more preferably 25 μm to 130 μm, and most preferably 38 μm to 75 μm. Within the above range, it is possible to balance the deflection of the adhesive sheet and the pick-up property, which is a preferable aspect.

In addition, the tensile strength in the MD direction (flow direction) of at least one resin layer can be set to any appropriate value. The tensile strength of the resin layer in the MD direction (flow direction) is preferably 90 MPa to 350 MPa, further preferably 110 MPa to 320 MPa, more preferably 130 MPa to 300 MPa, and most preferably 180 MPa to 250 MPa. Within the above range, the amount of deflection of the adhesive sheet can be suppressed, which is a preferable aspect.

In the technology disclosed here, the resin material constituting the resin layer (support, substrate) can be used without particular limitation, for example, transparency, mechanical strength, thermal stability, moisture barrier property, isotropy are preferably used , Flexibility, dimensional stability and other characteristics are excellent. In particular, since the resin layer has flexibility, the adhesive composition can be applied by a roll coater or the like and can be wound into a roll shape, which is useful.

As the above-mentioned resin layer, for example, polyester-based polymerization using polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate can be preferably used. Cellulose; diacetyl cellulose, triethyl cellulose cellulose and other cellulose-based polymers; polycarbonate-based polymers; polymethyl methacrylate and other acrylic polymers as the main resin component (main component of the resin component Typically, a plastic film composed of a resin material that accounts for more than 50% by mass is used as the resin layer. As other examples of the above-mentioned resin materials, styrene-based polymers such as polystyrene and acrylonitrile-styrene copolymers; polyethylene, polypropylene, polyolefins having a ring structure or norbornene structure, and ethylene- Olefin-based polymers such as propylene copolymers; vinyl chloride-based polymers; amide-based polymers such as nylon 6, nylon 6,6, and aromatic polyamides are used as resin materials. As another example of the above-mentioned resin material, there may be mentioned an imide-based polymer, a lanthanide-based polymer, a polyether lanthanide-based polymer, a polyetheretherketone-based polymer, a polyphenylene sulfide-based polymer, and a vinyl alcohol-based polymer , Vinylidene chloride polymer, vinyl alcohol butyraldehyde polymer, aryl ester polymer, polyoxymethylene polymer, epoxy polymer, etc. It may be a resin layer containing a blend of two or more of the above polymers.

In addition, as the resin layer, a plastic film containing a transparent thermoplastic resin material can be preferably used. Among the plastic films, at least one of the resin layers in the adhesive sheet of the present invention is a polyester film. kind. Here, the polyester film refers to polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate, etc. having a main skeleton based on an ester bond The polymer material (polyester resin) as the main resin component. The polyester film has excellent characteristics such as optical characteristics and dimensional stability, and is preferably a resin layer as an adhesive sheet (surface protective film). On the other hand, it has the property of being easily charged. In addition, as the resin layer satisfying the above tensile strength, the following resins may be mentioned. Polyester polymers such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate, etc. can be preferably used; Cellulose polymers such as triacetyl cellulose; polycarbonate polymers; acrylic polymers such as polymethyl methacrylate; polystyrene polymers; polyolefins with a cyclic structure or a norbornene structure ; Nylon 6, nylon 6,6, aromatic amides and other amide-based polymers as the main resin component (the main component of the resin component, typically accounts for more than 50% by mass The plastic film made of the resin material of the component) is used as the resin layer. It may be a resin layer containing a blend of two or more of the above polymers.

Various additives such as antioxidants, ultraviolet absorbers, plasticizers, colorants (pigments, dyes, etc.) may be blended in the resin material constituting the resin layer as necessary. In addition, the surface of the above-mentioned resin layer may be subjected to a known or conventional surface treatment such as corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, coating primer, and the like. Such surface treatment may be, for example, a treatment for improving the adhesion of the resin layer to the adhesive layer or top coat (anchoring of the adhesive layer, etc.). Surface treatment in which polar groups such as hydroxyl groups are introduced on the surface of the resin layer can be preferably used.

In addition, the configurations of the first resin layer and the second resin layer (for example, thickness, forming material, elastic modulus, tensile elongation, etc.) may be the same or different, and may be appropriately selected.

<Next Layer>

The "adhesive layer" in the present invention refers to a layer that joins the surfaces of adjacent resin layers and integrates them with practically sufficient adhesive force and adhesive time. Examples of the material for forming the adhesive layer include adhesives, adhesives, and tackifying coating agents. The subsequent layer may be a multilayer structure in which an adhesion-promoting coating is formed on the surface of the resin layer, and an adhesive layer is formed thereon. Furthermore, the "adhesive layer" in the present invention refers to a peelable (repeelable) one.

The ratio of the thickness of the next layer to the sum of the thickness of the first resin layer and the thickness of the second resin layer is 0.50 or less, preferably 0.40 or less, more preferably 0.35 or less, and most preferably 0.30 or less. By setting within such a range, the warpage of the adherend (for example, optical member) can be suppressed extremely well. On the other hand, the ratio of the above thickness is preferably 0.03 or more. By setting within such a range, the obtained adhesive sheet has more excellent bendability and can achieve extremely excellent peelability.

The thickness of the subsequent layer is preferably thinner than the thickness of the resin layer. The difference between the thickness of the resin layer and the thickness of the adhesive layer is preferably 2 μm or more, and more preferably 5 μm or more. If the difference is too small, depending on the thickness of the resin layer, the effect of suppressing warpage of the adherend (e.g., optical member) may change. Inadequate risk. The thickness of the subsequent layer is preferably 1 μm to 50 μm, more preferably 2 μm to 25 μm, and still more preferably 5 μm to 20 μm. If the thickness of the adhesive layer is too thick, there is a possibility that a defect (for example, paste defect) may occur in the formation of the adhesive layer.

According to the adhesive sheet of the present invention, stress relief is achieved by providing an adhesive layer, the peeling force of the obtained adhesive sheet is reduced, the pick-up property can be improved, and the pick-up can be lower than the peeling force of the resin layer alone. In addition, by having the resin layer film (the order of the first resin layer, the adhesive layer, and the second resin layer) formed by laminating the resin layers through the above-mentioned adhesive layer, the amount of deflection of the laminated film can be adjusted to that of each resin layer film. Compared with the improvement of the amount of deflection (reducing the amount of deflection), the problem of poor delivery caused by breakage or deformation during the delivery step can be improved, and an increase in manufacturing efficiency can be achieved. Furthermore, the storage elastic modulus of the adhesive layer at 23°C is 1.0×10 ⁴ Pa or more and less than 5.0×10 ⁷ Pa, preferably 1.0×10 ⁴ Pa or more and less than 1.0×10 ⁷ Pa, more preferably It is 1.0×10 ⁵ Pa or more and does not reach 1.0×10 ⁶ Pa. The storage elastic modulus of the adhesive layer can be measured using a dynamic viscoelasticity measuring device at a frequency of 1 Hz.

The subsequent layer is typically formed of an adhesive. As the adhesive, an acrylic adhesive is preferably used. The acrylic adhesive preferably contains a (meth)acrylic polymer and a crosslinking agent. The crosslinking agent can be used without particular limitation as long as it is a compound that reacts with the (meth)acrylic polymer, and isocyanate compounds, epoxy compounds, melamine resins, aziridine derivatives, and metal chelates are preferably used Compound.

The (meth)acrylic polymer refers to a polymer or copolymer synthesized from an acrylic monomer and/or a methacrylic monomer (referred to as "(meth)acrylate" in this specification). When the (meth)acrylic polymer is a copolymer, the arrangement state of the molecules is not particularly limited, and it may be a random copolymer, a block copolymer, or a graft copolymer. The preferred molecular arrangement is random copolymer. In addition, the polymerization method is not particularly limited, and polymerization can be carried out by known methods such as solution polymerization, emulsion polymerization, bulk polymerization, and suspension polymerization.

The (meth)acrylic polymer can be obtained by combining Obtained by polymerization or copolymerization. The alkyl group of the (meth)acrylic acid alkyl ester may be linear, branched or cyclic. The carbon number of the alkyl group of (meth)acrylic acid alkyl ester is preferably about 1 to 18, more preferably 1 to 10.

Specific examples of the alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, Isobutyl (meth)acrylate, third butyl (meth)acrylate, n-pentyl (meth)acrylate, isoamyl (meth)acrylate, n-hexyl (meth)acrylate, (meth)acrylic acid Isohexyl, n-heptyl (meth)acrylate, isoheptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate , N-nonyl (meth)acrylate, isononyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate. These can be used alone or in combination of two or more.

The (meth)acrylic polymer is preferably a copolymer of the alkyl (meth)acrylate and a (meth)acrylate containing a hydroxyl group. In this case, the carbon number of the alkyl group of (meth)acrylate is preferably 1-8, more preferably 2-8, still more preferably 2-6, and particularly preferably 4-6. The alkyl group of the (meth)acrylic acid alkyl ester may be linear or branched.

Specific examples of the above-mentioned hydroxyl-containing (meth)acrylate include 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 2-hydroxypropyl (meth)acrylate. , 4-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 5-hydroxypentyl (meth)acrylate, (meth)acrylic acid 3-Hydroxy-3-methylbutyl ester, 6-hydroxyhexyl (meth)acrylate, 7-hydroxyheptyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10 (meth)acrylic acid -Hydroxydecyl ester, 12-hydroxylauryl (meth)acrylate, (4-hydroxymethylcyclohexyl)methyl (meth)acrylate, etc. These can be used alone or in combination of two or more.

The carbon number of the hydroxyalkyl group of the hydroxy-containing (meth)acrylate is preferably less than the carbon number of the alkyl group of the (meth)acrylate. Of (meth)acrylates containing hydroxyl groups The carbon number of the hydroxyalkyl group is preferably 1 to 8, more preferably 2 to 4, and still more preferably 2. By adjusting the carbon number of the alkyl group in this way, the reactivity with the following isocyanate-based compound can be improved, and an adhesive agent having more excellent adhesive properties can be obtained.

The copolymerization amount of the above-mentioned hydroxyl group-containing (meth)acrylate is preferably 0.05 to 20 mol %, more preferably 0.10 to 8 mol %, further preferably 0.12 to 3 mol %, and still more preferably 0.14 ~1.5 mol%, the best is 0.14~0.25 mol%.

The above-mentioned (meth)acrylic polymer can also be obtained by copolymerizing other components in addition to the above-mentioned alkyl (meth)acrylate and hydroxyl-containing (meth)acrylate. The other components are not particularly limited, and (meth)acrylic acid, benzyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, ( Phenoxyethyl methacrylate, (meth)acrylamide, vinyl acetate, (meth)acrylonitrile, etc. The copolymerization amount of other components is preferably 100 parts by mass or less, and more preferably 50 parts by mass or less with respect to 100 parts by mass of alkyl (meth)acrylate.

The weight average molecular weight (Mw) of the (meth)acrylic polymer is preferably 400,000 or more, and more preferably 1,000,000, as measured by a gel permeation chromatography (GPC) method using tetrahydrofuran (THF) solvent. ~3 million, particularly preferably 1.2 million to 2.5 million.

Examples of the isocyanate-based compounds include 2,4-(or 2,6-)toluene diisocyanate, xylylene diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, and hexamethylene Diisocyanate, norbornene diisocyanate, chlorobenzene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, trimethylolpropane xylene diisocyanate, hydrogenated diphenyl Isocyanate monomers such as methane diisocyanate; addition type isocyanate compounds obtained by adding these isocyanate monomers to polyols such as trimethylolpropane; isocyanurate compounds; biuret type compounds; and Urethane prepolymer type isocyanate obtained by addition reaction of suitable polyether polyol or polyester polyol, acrylic polyol, polybutadiene polyol, polyisoprene polyol, etc. Etc. These can be used alone or in combination of two or more.

As the isocyanate-based compound, a commercially available product can be used as it is. Examples of commercially available isocyanate-based compounds include the Takenate series (trade names "D-110N, 500, 600, 700", etc.) manufactured by Mitsui Takeda Chemical Co., Ltd. and the Coronate series (manufactured by Japan Polyurethane Industry Co., Ltd.) Trade name "L, MR, EH, HL", etc.).

Examples of the epoxy compound include N,N,N',N'-tetraglycidyl m-xylylenediamine (trade name TETRAD-X, manufactured by Mitsubishi Gas Chemical Co., Ltd.), or 1,3-bis( N,N-glycidylaminomethyl)cyclohexane (trade name TETRAD-C, manufactured by Mitsubishi Gas Chemical Company), etc.

Examples of the melamine-based resin include hexamethylolmelamine and the like. Examples of the aziridine derivatives include commercially available product names such as HDU, TAZM, and TAZO (manufactured by Mutual Pharmaceutical Co., Ltd.).

Examples of the metal chelate compound include aluminum, iron, tin, titanium, nickel, and the like as metal components, and acetylene, methyl acetoacetate, and ethyl lactate, and the like as chelate components.

The content of the crosslinking agent used in the present invention is, for example, preferably 0.1 to 10 parts by mass, more preferably 0.2 to 4 parts by mass, and more preferably 100 parts by mass of the (meth)acrylic polymer. Preferably, it contains 0.3 to 1.5 parts by mass, and most preferably 0.4 to 0.9 parts by mass. By setting to this content, even under harsh (high temperature, high humidity) environment, good adhesion can be obtained. In addition, these crosslinking agents may be used alone or in combination of two or more.

The acrylic adhesive (adhesive composition) preferably further contains a silane coupling agent or a radiation hardening component. As the silane coupling agent, for example, those having any appropriate functional group can be selected. Examples of the functional groups include vinyl groups, epoxy groups, methacryl oxy groups, amine groups, mercapto groups, propenyl oxy groups, acetyl acetyl groups, isocyanate groups, styryl groups, and polysulfide groups. Specific examples of the above-mentioned silane coupling agent include vinyl trimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-glycidoxypropyltriethyl. Oxysilane, p-styryltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-acryloxypropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, γ-aminopropylmethoxysilane, γ-mercaptopropylmethyldimethoxysilane, bis(triethoxysilylpropyl) tetrasulfide , Γ-isocyanate propyl trimethoxysilane, etc. Among these, a silane coupling agent having an epoxy group is preferable, and γ-glycidoxypropyltrimethoxysilane is more preferable.

As the silane coupling agent, commercially available products can be used directly. Examples of commercially available products include KA series (trade name "KA-1003", etc.) and KBM series (trade name "KBM-303, KBM-403, KBM-503", etc. manufactured by Shin-Etsu Silicone Co., Ltd.) And KBE series (trade names "KBE-402, KBE-502, KBE-903", etc.), SH series (trade names "SH6020, SH6040, SH6062", etc.) manufactured by Toray Co., Ltd. and SZ series (trade name " SZ6030, SZ6032, SZ6300, etc.).

The content of the above-mentioned silane coupling agent is preferably 0.001 to 2.0 parts by mass, more preferably 0.005 to 2.0 parts by mass, further preferably 0.01 to 1.0 parts by mass, particularly preferably 100 parts by mass of the (meth)acrylic polymer. Preferably it is 0.02~0.5 parts by mass. By setting to such a content, even under severe (high temperature, high humidity) environment, the generation of peeling or bubbles can be suppressed.

As the radiation-hardenable component, monomers and/or oligomer components that undergo radical polymerization or cationic polymerization by radiation can be used. Examples of monomer components for radical polymerization using radiation include monomers having unsaturated double bonds such as (meth)acryloyl groups and vinyl groups, and in particular, it is preferred to use a monomer having an excellent reactivity. (Meth) acrylic monomer. Specific examples of the monomer component having a (meth)acryloyl group include allyl (meth)acrylate, caprolactone (meth)acrylate, cyclohexyl (meth)acrylate, and (meth) Group) N,N-diethylaminoethyl acrylate, 2-ethylhexyl (meth)acrylate, heptafluorodecyl (meth)acrylate, glycidyl (meth)acrylate, caprolactone Modified 2-hydroxyethyl (meth)acrylate, isobornyl (meth)acrylate, morpholine (meth)acrylate Ester, phenoxyethyl (meth)acrylate, tripropylene glycol di(meth)acrylate, bisphenol A diglycidyl ether di(meth)acrylate, hydroxypivalic acid neopentyl glycol di(meth) Base) acrylate, trimethylolpropane tri(meth)acrylate, trimethylolpropane ethoxytri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate Ester, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, caprolactone modified dipentaerythritol hexa(meth)acrylate, etc.

As an oligomer component for radical polymerization by radiation, it can be used to add more than two (meth)acryloyl, vinyl and other unsaturation to the skeleton of polyester, epoxy resin, urethane, etc. The double bond is a polyester (meth)acrylate, epoxy (meth)acrylate, urethane (meth)acrylate, etc., which have the same functional group as the monomer component.

The polyester (meth)acrylate is obtained by reacting (meth)acrylic acid with a polyester having a terminal hydroxyl group obtained from a polyhydric alcohol and a polycarboxylic acid. Specific examples include ARONIX M manufactured by Toya Synthetic Co., Ltd. -6000,7000,8000,9000 series polyester acrylate.

Epoxy (meth)acrylate is obtained by reacting (meth)acrylic acid with an epoxy resin. Specific examples include Ripoxy SP, VR series manufactured by Showa Polymer Co., Ltd. or Kyoeisha Chemical Co., Ltd. Epoxy Yester series epoxy acrylate manufactured by Co., Ltd.

The urethane (meth)acrylate is obtained by reacting a polyol, isocyanate, and hydroxy (meth)acrylate. Specific examples include Art Resin UN series manufactured by Genshang Industry Co., Ltd. NK Oligo U series manufactured by Nakamura Chemical Industry Co., Ltd. and SHIKOH UV series urethane acrylate manufactured by Japan Synthetic Chemical Industry Co., Ltd.

As the monomer and/or oligomer component for cationic polymerization, compounds having cationic polymerizable functional groups such as epoxy group, hydroxyl group, vinyl ether group, episulfide group, and ethylidene group are used, especially For the advantage of excellent reactivity, use the epoxy Compound. As the compound having an epoxy group, a glycidyl ether type epoxy resin produced by the reaction of a polyhydric phenol compound or a polyhydric alcohol and epichlorohydrin can be mentioned. Specifically, diglycidyl ether of bisphenol A or its alkylene oxide adduct, diglycidyl ether of bisphenol F or its alkylene oxide adduct, hydrogenated bisphenol A or its epoxy Alkyl adducts diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, butylene glycol diglycidyl ether, hexanediol di Glycidyl ether, cyclohexane dimethanol diglycidyl ether, polypropylene glycol diglycidyl ether, trimethylolpropane polyglycidyl ether, pentaerythritol polyglycidyl ether, sorbitol polyglycidyl ether, Resorcinol diglycidyl ether, etc.

When these (meth)acrylic polymers are properly combined with radiation-curable components, if the compatibility (mixability) is poor, it is difficult to obtain the balance between the adhesion after radiation curing and the storage elastic modulus, and the light transmission after curing For reasons such as poor performance, it is necessary to appropriately select a combination with better compatibility. In particular, in applications requiring light transmittance, adjustment is made so that the total light transmittance after hardening is 85% or more (preferably 90% or more), and the haze value is 10% or less (preferably 5% or less ). In addition, the compounding amount of the radiation hardening component is appropriately adjusted according to the storage elastic modulus and adhesiveness after radiation hardening. Generally speaking, it is 10 to 200 parts by mass relative to 100 parts by mass of the adhesive polymer, preferably 30 ~150 parts by mass.

The use amount of the multifunctional monomer is appropriately selected according to the balance with the (meth)acrylic polymer and the use as the adhesive sheet. In order to obtain sufficient heat resistance by the cohesive force of the acrylic adhesive, it is generally preferably 0.1 to 30 parts by mass relative to 100 parts by mass of the (meth)acrylic polymer. In addition, from the viewpoint of flexibility and adhesiveness, it is more preferably 10 parts by mass or less relative to 100 parts by mass of the (meth)acrylic polymer.

As the radiation, for example, ultraviolet rays, laser rays, α rays, β rays, γ rays, x rays, electron beams, etc. may be mentioned, and it is preferable to use ultraviolet rays in terms of good controllability and operability, and cost. It is more preferable to use ultraviolet rays with a wavelength of 200 to 400 nm. Ultraviolet Appropriate light sources such as high-pressure mercury lamps, microwave excitation lamps, and chemical lamps can be used for irradiation. Furthermore, when using ultraviolet rays as radiation, a photopolymerization initiator is added to the acrylic adhesive.

As the photopolymerization initiator, as long as it is a substance that generates radicals or cations by irradiating ultraviolet light of an appropriate wavelength that can be used as an initiator of the polymerization reaction according to the type of radiation-reactive component, it can be used as a photoradical polymerization. The starting agent may, for example, be benzoin, benzoin methyl ether, benzoin ethyl ether, methyl o-benzoyl benzoate, benzoin ethyl ether, benzoin isopropyl ether, α-methyl benzoin Acetophenones such as benzoin, benzoyl dimethyl ketal, trichloroacetophenone, 2,2-diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2- Phenylacetones such as hydroxy-2-methylbenzeneacetone, 2-hydroxy-4'-isopropyl-2-methylbenzeneacetone, benzophenone, methylbenzophenone, p-chlorobenzophenone, Benzophenones such as p-dimethylaminobenzophenone, thioxanthones such as 2-chlorothioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, bis(2, 4,6-trimethylbenzyl)-phenylphosphine oxide, 2,4,6-trimethylbenzyldiphenylphosphine oxide, (2,4,6-trimethylbenzoyl) Yl)-(ethoxy)-phenylphosphine oxide and other amide phosphine oxides, benzoyl amide, dibenzocycloheptenone, α-acyl oxime ester and the like. Examples of photocationic polymerization initiators include, for example, onium salts such as aromatic diazonium salts, aromatic iodonium salts, and aromatic cerium salts, or iron-aromatic hydrocarbon complexes, titanocene complexes, and aryl silicon Organometallic complexes such as aluminum alcohol complexes, nitrobenzyl esters, sulfonic acid derivatives, phosphate esters, sulfonic acid derivatives, phosphate esters, phenol sulfonate esters, diazonaphthoquinone, N-hydroxyacrylic acid Sulfamate, etc.

About the said photoinitiator, you may use 2 or more types together. The photopolymerization initiator is preferably prepared in the range of 0.1 to 10 parts by mass, preferably 0.2 to 7 parts by mass relative to 100 parts by mass of the (meth)acrylic polymer.

In addition, photopolymerization initiation aids such as amines may be used in combination. Examples of the photopolymerization initiation polymerization aid include 2-dimethylaminoethyl benzoate, dimethylaminoacetophenone, ethyl p-dimethylaminobenzoate, and p-dimethylamine. Isoamyl benzoate and so on. With regard to the aforementioned photopolymerization initiation aid, two or more kinds may be used in combination. The polymerization initiation aid is preferably relative to 100 parts by mass of (meth)acrylic polymer is prepared in the range of 0.05 to 10 parts by mass, and further 0.1 to 7 parts by mass.

<Lamination method of first resin layer and second resin layer>

As a method of laminating the first resin layer and the second resin layer, any appropriate method can be adopted. As a preferred embodiment, a method of forming an adhesive layer on one resin layer and stacking another resin layer on the adhesive layer can be used. In addition, as a method of forming the adhesive layer, any appropriate method can be adopted. As a specific example, the adhesive can be formed by applying the above adhesive (adhesive composition solution) on the resin layer and heating. At the time of coating, the polymer concentration of the acrylic adhesive is preferably adjusted appropriately using a solvent (for example, ethyl acetate or toluene). The heating temperature is preferably 20°C to 200°C, and more preferably 50°C to 170°C.

The thickness of the resin film (composed of a first resin layer, an adhesive layer and a second resin layer in sequence) is preferably 11 μm to 230 μm, more preferably 50 μm to 110 μm.

<adhesive layer>

The adhesive sheet of the present invention has the above-mentioned adhesive layer, and the above-mentioned adhesive layer is formed of an adhesive composition. As the above-mentioned adhesive composition, as long as it has adhesiveness, it can be used without particular limitation. For example, acrylic adhesives, urethane adhesives, polyester adhesives, synthetic rubber adhesives, natural rubber adhesives, polysiloxane adhesives, etc., among which acrylic acid is more preferred It is particularly preferable to use an acrylic adhesive using a (meth)acrylic polymer as the adhesive and/or urethane adhesive.

When an acrylic adhesive is used for the adhesive layer, the (meth)acrylic polymer constituting the acrylic adhesive may use a (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms As a raw material monomer constituting the polymer. As the above-mentioned (meth)acrylic monomer, one kind or two or more kinds can be used as a main component. By using the above-mentioned (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms, it is easy to control the adhesion to the adherend (protected object) to be low, and light peelability or Excellent stripping Different sticky sheets. Furthermore, (meth)acrylic polymer in the present invention refers to acrylic polymer and/or methacrylic polymer, and (meth)acrylate refers to acrylate and/or methacrylate .

Specific examples of the (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms include methyl (meth)acrylate, ethyl (meth)acrylate, and (meth)acrylic acid. N-butyl ester, second butyl (meth)acrylate, third butyl (meth)acrylate, isobutyl (meth)acrylate, hexyl (meth)acrylate, 2-ethyl (meth)acrylate Hexyl ester, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, (A Group) isodecyl acrylate, n-dodecyl (meth) acrylate, n-tridecyl (meth) acrylate, n-tetradecyl (meth) acrylate, etc.

Among them, when the adhesive sheet of the present invention is used as a surface protective film, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, ( Isooctyl meth)acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-(meth) acrylate (Meth)acrylic monomers such as dodecyl ester, n-tridecyl (meth)acrylate, n-tetradecyl (meth)acrylate, etc. having a C 6-14 alkyl group are used as The best. In particular, by using a (meth)acrylic monomer having an alkyl group having 6 to 14 carbon atoms, it is easy to control the adhesion to the adherend to be low, and it becomes excellent in removability.

In particular, it is preferably 50% by mass or more, more preferably 60% by mass or more, and still more preferably 70% by mass or more with respect to 100% by mass of the total monomer components constituting the (meth)acrylic polymer. 3. The best is 80~93% by mass of (meth)acrylic monomers with a C1-C14 alkyl group. If it is less than 50% by mass, the moderate wettability of the adhesive composition or the cohesive force of the adhesive layer becomes poor, which is not good.

In addition, in the adhesive composition of the present invention, it is preferable that the (meth)acrylic polymer contains a (meth)acrylic monomer having a hydroxyl group as a raw material monomer. As the above One or more than two (meth)acrylic monomers with hydroxyl groups can be used as the main component.

By using the above-mentioned (meth)acrylic monomer having a hydroxyl group, it is easy to control the crosslinking of the adhesive composition, etc., and thus it is easy to control the balance between the improvement in wettability due to flow and the reduction in adhesion in peeling. In addition, unlike carboxyl groups or sulfonate groups that can generally function as crosslinking sites, hydroxyl groups and ionic compounds as antistatic components (antistatic agents), or organic polysiloxanes with oxyalkylene chains It has moderate interaction, so it can also be used preferably in terms of antistatic properties and pickup properties.

Examples of the (meth)acrylic monomer having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. , 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, (meth)acrylic acid (4-hydroxymethylcyclohexyl) methyl ester, N-methylol (meth) acrylamide, etc. In particular, the use of a (meth)acrylic monomer having a hydroxyl group with an alkyl group having a carbon number of 4 or more facilitates light peeling during high-speed peeling, which is preferable.

With respect to 100 parts by mass of the (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms, it is preferable to contain 15 parts by mass or less of the (meth)acrylic monomer having the hydroxyl group, more preferably It is 1-13 parts by mass, more preferably 2-11 parts by mass, and most preferably 3.5-10 parts by mass. Within the above range, it is easy to control the balance between the wettability of the adhesive composition and the cohesive force of the obtained adhesive layer, which is preferable. In addition, in particular, by blending 5 parts by mass or more, it is easy to obtain an adhesive composition with better creep properties.

In addition, as other polymerizable monomer components, it is possible to adjust the glass transition temperature or peeling of the (meth)acrylic polymer within a range that does not impair the effects of the present invention because it is easy to achieve a balance of adhesive properties. Polymerizable monomer so that Tg is 0°C or lower (usually -100°C or higher).

As the (meth)acrylic polymer used in addition to the above has a carbon number of 1 ~ The (meth)acrylic monomer of the alkyl group of 14 and other polymerizable monomers other than the above-mentioned (meth)acrylic monomer having a hydroxyl group, a (meth)acrylic monomer having a carboxyl group can be used.

Examples of the (meth)acrylic monomer having a carboxyl group include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, and hexahydrophthalic acid 2- (Meth)acryloyloxyethyl, hexahydrophthalic acid 2-(meth)acryloyloxypropyl ester, phthalic acid 2-(meth)acryloyloxyethyl, succinic acid 2 -(Meth)acrylic acid ethyl ester, maleic acid 2-(meth)acrylic acid ethyl ester, carboxypolycaprolactone mono(meth)acrylate, tetrahydrophthalic acid 2-( Methyl) propylene acetylacetate and so on.

The (meth)acrylic monomer having a carboxyl group is preferably 5 parts by mass or less relative to 100 parts by mass of the (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms, and more preferably 1 part by mass or less, more preferably less than 0.2 part by mass, and most preferably 0.01 part by mass or more and less than 0.1 part by mass. In particular, when a (meth)acrylic monomer having a carboxyl group and a (meth)acrylic monomer having a hydroxyl group are used in combination, it may be more difficult to obtain an adhesive composition having excellent creep characteristics Good use. In addition, if it exceeds 5 parts by mass, a large amount of acid functional groups of the carboxyl group having a large interaction exist. When an ionic compound is formulated as an antistatic component, the acid functional group such as a carboxyl group interacts with the ionic compound, thereby There is a risk of impeding ion conduction, reducing the conductivity efficiency, and failing to obtain sufficient antistatic properties, which is not good. In addition, especially in the case of achieving both creep characteristics and light peelability, by containing 5 parts by mass or more of the above-mentioned (meth)acrylic monomer having a hydroxyl group and containing 0.01 parts by mass or more and less than 0.1 parts by mass The above-mentioned (meth)acrylic monomer having a carboxyl group can achieve both characteristics and is therefore preferable.

In addition, as the (meth)acrylic polymer used in addition to the (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms, a (meth)acrylic monomer having a hydroxyl group and having The polymerizable monomer other than the (meth)acrylic monomer of the carboxyl group can be used without particular limitation as long as it does not impair the characteristics of the present invention. For example, When using cyano group-containing monomers, vinyl ester monomers, aromatic vinyl monomers and other components that improve cohesion and heat resistance, or amide group-containing monomers, amide imine group-containing monomers, amine group-containing monomers , Epoxy group-containing monomers, N-acryl morpholine, vinyl ether monomers and other components that increase adhesion or have functional groups that act as crosslinking sites. These polymerizable monomers may be used alone or in combination of two or more.

Examples of the cyano group-containing monomer include acrylonitrile and methacrylonitrile.

Examples of vinyl ester monomers include vinyl acetate, vinyl propionate, and vinyl laurate.

Examples of the aromatic vinyl monomer include styrene, chlorostyrene, chloromethylstyrene, α-methylstyrene, and other substituted styrenes.

As the amide group-containing monomer, for example, acrylamide, methacrylamide, diethylacrylamide, N-vinylpyrrolidone, N,N-dimethylacrylamide, N,N- Dimethylmethacrylamide, N,N-diethylacrylamide, N,N-diethylmethacrylamide, N,N,-methylenebisacrylamide, N,N- Dimethylaminopropylacrylamide, N,N-dimethylaminopropylmethacrylamide, diacetoneacrylamide, etc.

Examples of the imidate group-containing monomer include cyclohexylmaleimide, isopropylmaleimide, N-cyclohexylmaleimide, itaconic amide, and the like.

Examples of the amine group-containing monomer include: aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, N,N-dimethyl (meth)acrylate Aminopropyl ester and so on.

Examples of the epoxy group-containing monomer include glycidyl (meth)acrylate, methylglycidyl (meth)acrylate, allyl glycidyl ether, and the like.

Examples of vinyl ether monomers include methyl vinyl ether, ethyl vinyl ether, and isobutyl vinyl ether.

In the present invention, except for the (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms, the (meth)acrylic monomer having a hydroxyl group, and the (meth)acrylic monomer having a carboxyl group Other polymerizable monomers with respect to the above (meth)propylene having an alkyl group having 1 to 14 carbon atoms 100 parts by mass of the enoic acid-based monomer, preferably 0 to 40 parts by mass, more preferably 0 to 30 parts by mass. By using the other polymerizable monomers in the above range, when an ionic compound is used as an antistatic agent, good interaction with the ionic compound and good re-peelability can be adjusted appropriately.

The weight average molecular weight (Mw) of the (meth)acrylic polymer is preferably 100,000 to 5 million, more preferably 200,000 to 2 million, and further preferably 300,000 to 1 million. When the weight-average molecular weight is less than 100,000, the cohesive force of the adhesive layer is reduced, so there is a tendency for the paste to remain. On the other hand, when the weight average molecular weight exceeds 5 million, the fluidity of the polymer decreases, and the wetting of the adherend (such as a polarizing plate) becomes insufficient, which may cause the adherend to adhere to the adhesive sheet The tendency to swell between the layers of the agent. Furthermore, the weight average molecular weight refers to the one obtained by gel permeation chromatography (GPC).

The glass transition temperature (Tg) of the (meth)acrylic polymer is preferably 0°C or lower, more preferably -10°C or lower (usually -100°C or higher). When the glass transition temperature is higher than 0°C, the polymer is difficult to flow, for example, the wetting of the polarizer becomes insufficient, which tends to cause bulging between the polarizer and the adhesive layer of the adhesive sheet. In particular, by setting the glass transition temperature to -61°C or lower, it is easy to obtain an adhesive layer excellent in wettability and light peelability to the polarizing plate. Furthermore, the glass transition temperature of the (meth)acrylic polymer can be adjusted within the above range by appropriately changing the monomer component or composition ratio used.

The polymerization method of the (meth)acrylic polymer is not particularly limited, and it can be polymerized by a known method such as solution polymerization, emulsification polymerization, bulk polymerization, suspension polymerization, etc., especially from the viewpoint of workability, or In terms of characteristics such as low pollution of the body (protected object), solution polymerization is more preferable. In addition, the obtained polymer may be any one of a random copolymer, a block copolymer, an alternating copolymer, and a graft copolymer. In addition, polymerization conditions, polymerization solvents, polymerization initiators, and the like can also be appropriately used based on known techniques.

When a urethane-based adhesive is used for the adhesive layer, any suitable urethane-based adhesive can be used as the urethane-based adhesive. As such a urethane-based adhesive, it is preferable to include a urethane resin obtained by reacting a polyol and a polyisocyanate. Examples of the polyol include polyether polyol, polyester polyol, polycarbonate polyol, and polycaprolactone polyol. Examples of the polyisocyanate-based compound include diphenylmethane diisocyanate, toluene diisocyanate, and hexamethylene diisocyanate.

<Organic polysiloxane with oxyalkylene chain>

The adhesive layer of the present invention is formed of an adhesive composition. The adhesive composition contains an organic polysiloxane having an oxyalkylene chain, preferably an organic polysiloxane having an oxyalkylene main chain alkyl. It is speculated that by using the above-mentioned organic polysiloxane, the surface free energy on the surface of the adhesive can be reduced, and even if the content is small, both low pollution and light peeling can be taken into account. In addition, by using the above-mentioned organic polysiloxane, the adhesion with the adherend is reduced, so the pick-up property is improved, and even an adhesive sheet composed of a thick resin layer can exhibit light peeling, so The better way.

As the above-mentioned organopolysiloxane, a well-known organopolysiloxane having a polyoxyalkylene main chain can be suitably used, and it is preferably represented by the following formula.

(In the formula, R ₁ and/or R ₂ have an oxyalkylene chain having 1 to 6 carbon atoms. The alkylene group in the oxyalkylene chain may be linear or branched. The terminal may be an alkoxy group or a hydroxyl group. In addition, either of R ₁ or R ₂ may be a hydroxyl group, or may be an alkyl group, an alkoxy group, or may be a part of the above alkyl group or alkoxy group substituted with a hetero atom Functional group. n is an integer from 1 to 300.)

As the organic polysiloxane, a site containing a siloxane (a siloxane site) is used as the main chain, and an oxyalkylene chain is bonded to the end of the main chain. It is speculated that by using the above-mentioned organic polysiloxane having an oxyalkylene chain, the compatibility with the (meth)acrylic polymer can be balanced, and both low pollution and light peeling can be achieved.

In addition, as the above-mentioned organic polysiloxane in the present invention, for example, the following structure can be used. Specifically, R ₁ and/or R ₂ in the formula have an oxyalkylene chain containing a hydrocarbon group having 1 to 6 carbon atoms. Examples of the oxyalkylene chain include oxymethylene, oxyethyl, Oxypropylene, oxybutyl, etc., among them, oxyethyl or oxypropyl is preferred. In addition, when both R ₁ and R ₂ have an oxyalkylene chain, the oxyalkylene chains may be the same or different.

In addition, the hydrocarbon group of the oxyalkylene chain may be linear or branched.

In addition, the terminal of the above-mentioned oxyalkylene chain may be an alkoxy group or a hydroxyl group, and among them, an alkoxy group is more preferable. When the separator is attached to the surface of the adhesive layer for the purpose of protecting the adhesive surface, the organic polysiloxane with hydroxyl groups at the end sometimes interacts with the separator, when the separator is peeled off from the surface of the adhesive layer The adhesion (peeling) force rises.

In addition, n is an integer of 1 to 300, preferably 10 to 200, and more preferably 20 to 150. If n is within the above range, a balance of compatibility with the base polymer can be obtained, which is a preferable aspect. In addition, the molecule may have reactive substituents such as (meth)acryloyl, allyl, and hydroxyl groups. The above-mentioned organic polysiloxanes may be used alone or in combination of two or more.

Specific examples of the above-mentioned organic polysiloxane having an oxyalkylene chain include, for example, commercially available product names X-22-4952, X-22-4272, X-22-6266, and KF- 6004, KF-889 (above manufactured by Shin-Etsu Chemical Industry Co., Ltd.), BY16-201, SF8427 (above manufactured by Toray Dow Corning Corporation), IM22 (made by Asahi Kasei Wacker Corporation), etc. These compounds can be used alone or in combination of two or more.

In addition, in addition to organic polysiloxanes having (bonded) oxyalkylene chains in the main chain, organic polysiloxanes having (bonded) oxyalkylene chains in the side chain can also be used. Compared with the organic polysiloxane having an oxyalkylene chain, it is better to use an organic polysiloxane having a side chain having an oxyalkylene chain. As the above-mentioned organopolysiloxane, a well-known organopolysiloxane having a polyoxyalkylene side chain can be suitably used, and it is preferably represented by the following formula.

(In the formula, R ₁ is a monovalent organic group, R ₂ , R ₃ and R ₄ are alkylene groups, R ₅ is hydrogen or an organic group, m and n are integers from 0 to 1000, where m and n are different When the time is 0, a and b are integers from 0 to 100, where a and b are not 0 at the same time.)

In addition, as the above-mentioned organic polysiloxane in the present invention, for example, the following structure can be used. Specifically, R ₁ in the formula is a monovalent organic group exemplified by alkyl groups such as methyl, ethyl, propyl, aryl groups such as phenyl, tolyl, or aralkyl groups such as benzyl, phenethyl, etc. It may have a substituent such as a hydroxyl group. R ₂ , R ₃ , and R ₄ can use alkylene groups having 1 to 8 carbon atoms, such as methylene, ethylidene, and propylidene groups. Here, R ₃ and R ₄ are different alkylene groups, and R ₂ and R ₃ or R ₄ may be the same or different. In order to increase the concentration of antistatic components (ionic liquid with a melting point below 100°C, alkali metal salts, etc.) that can be dissolved in the side chain of the polyoxyalkylene group, it is preferable that either of R ₃ and R ₄ is Extend ethyl or propyl. R ₅ may be a monovalent organic group exemplified by an alkyl group such as a methyl group, an ethyl group, a propyl group, or an acetyl group such as an acetyl group or a propyl group, and each may have a substituent such as a hydroxyl group. These compounds can be used alone or in combination of two or more. In addition, the molecule may have reactive substituents such as (meth)acryloyl, allyl, and hydroxyl groups. It is presumed that among the above-mentioned organic polysiloxanes having polyoxyalkylene side chains, in particular, organic polysiloxanes having polyoxyalkylene side chains having hydroxyl terminals can easily achieve a balance of compatibility, which is preferable.

Specific examples of the above-mentioned organic polysiloxanes include, for example, commercially available product names KF-351A, KF-352A, KF-353, KF-354L, KF-355A, KF-615A, KF-945, KF-640, KF-642, KF-643, KF-6022, X-22-6191, X-22-4515, KF-6004, KF-6011, KF-6012, KF-6015, KF-6017, KF- 6020, X-22-2516 (made by Shin-Etsu Chemical Industry Corporation), SF8428, FZ-2162, SH3749, FZ-77, L-7001, FZ-2104, FZ-2110, L-7002, FZ-2122, FZ -2164, FZ-2203, FZ-7001, SH8400, SH8700, SH8410, SF8422 (above manufactured by Toray-Dow Corning), TSF-4440, TSF-4441, TSF-4445, TSF-4450, TSF-4446, TSF -4452, TSF-4460 (manufactured by Meitu High-tech Materials), BYK-333, BYK-307, BYK-377, BYK-UV3500, BYK-UV3570 (manufactured by BYK-Chemie Japan), etc. These compounds can be used alone or in combination of two or more.

As the above-mentioned organic polysiloxane used in the present invention, the HLB (Hydrophile-Lipophile Balance) value is preferably 1 to 16, more preferably 3 to 14. If the HLB value deviates from the above range, the pollution to the adherend becomes poor, which is not good.

In addition, the content of the organic polysiloxane is preferably 0.01 to 5 parts by mass, more preferably 0.07 to 3 parts by mass, and still more preferably 0.05 to 1 with respect to 100 parts by mass of the (meth)acrylic polymer. Quality parts. Within the above range, it is easy to balance antistatic properties and light peelability (repeelability), which is preferable.

<Antistatic component in adhesive layer>

In the adhesive sheet of the present invention, the adhesive composition constituting the adhesive layer may contain an antistatic component, and more preferably contains an ionic compound as the antistatic component. Examples of the ionic compounds include alkali metal salts and/or ionic liquids having a melting point of 100°C or lower. By containing the plasma liquid, excellent antistatic properties can be imparted. In addition, the adhesive layer (using an antistatic component) formed by crosslinking the adhesive composition containing an antistatic component as described above can prevent the adherend (such as a polarizing plate) that has not undergone antistatic treatment during peeling Static electricity becomes an adhesive sheet that reduces contamination of the adherend. Therefore, it is very useful as an antistatic adhesive sheet in the technical field related to optical and electronic parts where static electricity or pollution becomes a particularly serious problem.

In addition, the content of the antistatic component is preferably 4.9 parts by mass or less, more preferably 0.001 to 0.9 parts by mass, more preferably 0.005 to 0.8 parts by mass, most preferably 100 parts by mass of the (meth)acrylic polymer. It is preferably 0.01 to 0.5 parts by mass. Within the above range, it is easy to achieve both antistatic properties and low pollution properties, which is preferable.

<crosslinking agent>

In the adhesive sheet of the present invention, the adhesive composition preferably contains a crosslinking agent. In addition, in the present invention, the above adhesive composition can be used to form an adhesive layer. For example, when the adhesive contains the (meth)acrylic polymer, by appropriately adjusting the constituent units of the (meth)acrylic polymer, the composition ratio, the selection of the crosslinking agent and Crosslinking by addition ratio etc. can obtain an adhesive sheet (adhesive layer) with more excellent heat resistance.

As the crosslinking agent used in the present invention, isocyanate compounds, epoxy compounds, melamine-based resins, aziridine derivatives, metal chelate compounds and the like can be used. In particular, the use of isocyanate compounds is preferred. In addition, these compounds may be used alone or in combination of two or more.

Examples of the isocyanate compound (isocyanate-based cross-linking agent) include aliphatic polyisocyanates such as trimethylene diisocyanate, butylene diisocyanate, hexamethylene diisocyanate (HDI), and dimer acid diisocyanate. Alicyclic isocyanates such as cyclopentyl diisocyanate, cyclohexylene diisocyanate, isophorone diisocyanate (IPDI), 2,4-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, benzene di Aromatic isocyanates such as methylene diisocyanate (XDI), via allophanate bond, biuret bond, isocyanurate bond, uretdione bond, urea bond, carbodiimide bond, urea A polyisocyanate modified product obtained by modifying the isocyanate compound, such as a ketimine bond and an oxadiazine trione bond. For example, as a commercially available product, the trade names TAKENATE 300S, TAKENATE 500, TAKENATE D165N, TAKENATE D178N (above are manufactured by Takeda Pharmaceutical Industries Co., Ltd.), Sumidur T80, Sumidur L, Desmodur N3400 (above are manufactured by Sumitomo Bayer Polyurethane Co., Ltd.) , Millionate MR, Millionate MT, Coronate L, Coronate HL, Coronate HX (the above is manufactured by Japan Polyurethane Industry Corporation), etc. These isocyanate compounds may be used alone, or two or more kinds may be used in combination, or a difunctional isocyanate compound and a trifunctional or more isocyanate compound may be used in combination. By using a cross-linking agent in combination, stable adhesion and rebound resistance (adhesion to curved surfaces) can be taken into account, and an adhesive sheet with superior adhesion reliability can be obtained.

In addition, when a difunctional isocyanate compound and a trifunctional or higher isocyanate compound are used in combination as the above isocyanate compound, the compounding ratio (mass ratio) of the two compounds is preferably [2 functional isocyanate compound]/[3 The isocyanate compound above functional level] (mass ratio) is 0.1/99.9~50/50, preferably 0.1/99.9~ 20/80, further preferably 0.1/99.9 to 10/90, particularly preferably 0.1/99.5 to 5/95, and most preferably 0.1/99.9 to 1/99. By adjusting and adjusting within the above range, it becomes an adhesive layer excellent in adhesiveness and rebound resistance, which is a better aspect.

Examples of the epoxy compound include N,N,N',N'-tetraglycidyl m-xylylenediamine (trade name TETRAD-X, manufactured by Mitsubishi Gas Chemical Co., Ltd.), or 1,3-bis( N,N-diglycidylaminomethyl)cyclohexane (trade name TETRAD-C, manufactured by Mitsubishi Gas Chemical Company), etc.

Examples of the melamine-based resin include hexamethylolmelamine and the like. Examples of the aziridine derivatives include commercially available product names such as HDU, TAZM, and TAZO (above are manufactured by Mutual Pharmaceutical Co., Ltd.) and the like.

Examples of the metal chelate compound include aluminum, iron, tin, titanium, nickel, and the like as metal components, and acetylene, methyl acetoacetate, and ethyl lactate, and the like as chelate components.

The content of the crosslinking agent used in the present invention is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 8 parts by mass, and more preferably 100 parts by mass of the (meth)acrylic polymer. Contains 0.5 to 5 parts by mass, preferably 1 to 4 parts by mass. In the case where the above content is less than 0.01 parts by mass, the crosslinking formed by the crosslinking agent becomes insufficient, the cohesive force of the adhesive layer obtained becomes low, and sometimes sufficient heat resistance cannot be obtained. The tendency of paste residue. On the other hand, when the content exceeds 10 parts by mass, the cohesive force of the polymer is large, the fluidity decreases, and the wetting of the adherend (such as a polarizing plate) becomes insufficient, which may cause the adherend and adhesion The tendency to swell between the adhesive layers (adhesive composition layers). In addition, if the amount of the cross-linking agent is large, the peeling electrostatic characteristics tend to decrease. In addition, these crosslinking agents may be used alone or in combination of two or more.

The above-mentioned adhesive composition may further contain a crosslinking catalyst for making any of the above crosslinking reactions more efficient. As the above-mentioned cross-linking catalyst, for example, tin-based catalysts such as dibutyltin dilaurate and dioctyltin dilaurate, and tris(acetylacetone) can be used. Iron, tri(hexane-2,4-dione) iron, tri(heptane-2,4-dione) iron, tri(heptane-3,5-dione) iron, tri(5-methyl Hexane-2,4-dione) iron, tri(octane-2,4-dione) iron, tri(6-methylheptane-2,4-dione) iron, tri(2,6- Dimethylheptane-3,5-dione) iron, tri(nonane-2,4-dione) iron, tri(nonane-4,6-dione) iron, tri(2,2,6 ,6-tetramethylheptane-3,5-dione) iron, tri(tridecane-6,8-dione) iron, tri(1-phenylbutane-1,3-dione) iron , Tris(hexafluoroacetone acetone) iron, tris(acetate ethyl acetate) iron, tris(acetoacetate n-propyl acetate) iron, tris(acetoacetate isopropyl) iron, tris(acetoacetate n-butyl acetate) Ester) iron, tris(acetylacetate second butyl) iron, tris(acetylacetate third butyl) iron, tris(propylacetate methyl) iron, tris(ethylacetate) iron, tri( N-propyl propyl acetate) iron, tri(isopropyl propyl acetate) iron, tri(propyl propyl acetate n-butyl) iron, tri(propyl acetyl acetate second butyl) iron, tri(propyl acetyl acetate third Butyl ester) iron, tris(acetoacetate benzyl) iron, tris(dimethyl malonate) iron, tris(diethyl malonate) iron, trimethoxy iron, triethoxy iron, triiso Iron propionate, ferric chloride and other iron catalysts. One type of these crosslinking catalysts may be used, or two or more types may be used in combination.

The content (usage) of the cross-linking catalyst is not particularly limited. For example, it is preferably 0.0001 to 1 part by mass, more preferably 0.001 to 0.5 part by mass relative to 100 parts by mass of the (meth)acrylic polymer. . Within the above range, the speed of the cross-linking reaction is faster when the adhesive layer is formed, and the pot life of the adhesive composition also becomes longer, which is a better aspect.

In addition, the above-mentioned adhesive composition may further contain other well-known additives. For example, powders such as colorants and pigments, surfactants, plasticizers, tackifiers, low molecular weight polymers, Surface lubricants, leveling agents, antioxidants, corrosion inhibitors, light stabilizers, ultraviolet absorbers, polymerization inhibitors, silane coupling agents, inorganic or organic fillers, metal powders, particles, foils, etc.

The adhesive sheet of the present invention is formed by forming the above-mentioned adhesive layer on the second resin layer. At this time, the cross-linking of the adhesive composition is generally performed after the coating of the adhesive composition. The adhesive layer of the combined adhesive composition is transferred onto the resin layer and the like.

In addition, the method of forming the adhesive layer on the second resin layer is not particularly limited. For example, the resin layer can be applied to the resin layer by applying the above adhesive composition (solution) to the resin layer and drying to remove the polymerization solvent. It is made by forming an adhesive layer on it. Then, for the purpose of adjusting the composition transfer of the adhesive layer or adjusting the crosslinking reaction, etc., curing can be performed. In addition, when the adhesive composition is applied on the resin layer to make an adhesive sheet, one or more solvents other than the polymerization solvent may be newly added to the adhesive composition to enable uniform application on the resin layer .

In addition, as a method of forming the adhesive layer when manufacturing the adhesive sheet of the present invention, a well-known method used in the manufacture of adhesive tapes can be used. Specific examples include roll coating, gravure coating, reverse coating, roll brushing, spray coating, air knife coating method, extrusion coating method using a die coater, and the like.

Generally, the thickness of the adhesive layer is 3 μm to 100 μm, preferably 5 μm to 50 μm. If the thickness of the adhesive layer is within the above range, it is easy to obtain a proper balance between re-peelability and adhesion (adhesion), which is preferable.

<spacer>

In the adhesive sheet of the present invention, the spacer can be attached to the surface of the adhesive layer as needed to protect the adhesive surface.

As a material constituting the above-mentioned separator, there is paper or a plastic film, and in terms of excellent surface smoothness, it is preferable to use a plastic film. The film is not particularly limited as long as it can protect the adhesive layer, and examples thereof include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, and poly Vinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, ethylene-vinyl acetate copolymer film, etc.

The thickness of the separator is usually 5 μm to 200 μm, preferably about 10 μm to 100 μm. If it is within the above range, the adhesion workability on the adhesive layer and the peeling workability from the adhesive layer are excellent, which is preferable. The silicone can be used on the above separators as needed Mold release agents, fluorine-based mold release agents, long-chain alkyl-based mold release agents or fatty amide-based mold release agents, silica powder, etc. are used for mold release and antifouling treatment, or for coating type, mixing type, steaming Antistatic treatment such as plating.

<Top coat (antistatic layer)>

The adhesive sheet of the present invention is characterized by sequentially having a first resin layer, an adhesive layer, a second resin layer, and an adhesive layer formed of an adhesive composition, and further having the adhesive agent The surface opposite to the surface of the layer has a topcoat consisting of a polyaniline sulfonic acid as a conductive polymer component, a polyester resin as a binder component, and an isocyanate compound as a crosslinking agent Former for topcoat composition. Since the above-mentioned adhesive sheet has a surface coating, the anti-static property of the adhesive sheet is improved, which is a preferable aspect.

<conductive polymer>

The above top coat is characterized by containing polyaniline sulfonic acid as a conductive polymer component. By using the above conductive polymer, the antistatic property based on the top coat and the antistatic property over time can be satisfied. In addition, the above-mentioned polyaniline sulfonic acid-based "water-soluble" can be immobilized in the top coat by using the following isocyanate-based cross-linking agent, and water resistance can be improved. By using an aqueous solution containing the above-mentioned water-soluble conductive polymer, a top coat having excellent surface resistivity over time can be obtained, which is a preferable aspect. On the other hand, when the conductive polymer used in forming the top coat layer is "water-dispersible", if a solution containing the above-mentioned water-dispersible conductive polymer is used to form the top coat layer, aggregates are likely to be generated. It cannot be coated uniformly, and the surface resistivity tends to deteriorate significantly over time, which is not good.

The amount of the conductive polymer used is preferably 10 to 200 parts by mass, more preferably 25 to 150 parts by mass, and more preferably 40 to 120 parts by mass relative to 100 parts by mass of the binder contained in the top coat. . If the amount of the conductive polymer used is too small, the antistatic effect may be reduced. If the amount of the conductive polymer used is too large, the adhesion between the top coat and the resin layer may decrease or the transparency may decrease. Therefore it is not good.

The polyaniline sulfonic acid used as the conductive polymer component has a weight average molecular weight (Mw) in terms of polystyrene of preferably 5×10 ⁵ or less, more preferably 3×10 ⁵ or less. In addition, the weight average molecular weight of these conductive polymers is usually preferably 1×10 ³ or more, and more preferably 5×10 ³ or more.

As a method of forming the above-mentioned top coat layer, it is possible to apply a composition for top coat (coating material for forming top coat) to the first surface of the resin layer (base material, support) and dry it (or Hardening), as a conductive polymer component used in the preparation of the topcoat composition, it contains polyaniline sulfonic acid, a polyester resin as a binder, and an isocyanate-based crosslinking agent as a crosslinking agent. As the component, the above-mentioned essential component can be preferably used in a form dissolved in water (a conductive polymer aqueous solution, or simply an aqueous solution). The above-mentioned aqueous conductive polymer solution can be prepared, for example, by dissolving a conductive polymer having a hydrophilic functional group (which can be synthesized by a method such as copolymerization of a monomer having a hydrophilic functional group in the molecule) in water. Examples of the hydrophilic functional group include sulfo group, amine group, amide group, imine group, hydroxyl group, mercapto group, hydrazine group, carboxyl group, quaternary ammonium group, sulfate group (-O-SO ₃ H), phosphoric acid Ester group (for example -O-PO(OH) ₂ ), etc. The above-mentioned hydrophilic functional group may form a salt.

In addition, as a commercially available product of the above polyaniline sulfonic acid aqueous solution, a brand name "aqua-PASS" manufactured by Mitsubishi Rayon Co., Ltd. and the like can be exemplified.

The topcoat disclosed here contains polyaniline sulfonic acid (polyaniline type) as a conductive polymer component as an essential component, but, for example, may contain one or more antistatic components (conductive polymer) Other than organic conductive materials, inorganic conductive materials, antistatic agents, etc.). Furthermore, as a preferable aspect, the top coat layer does not substantially contain antistatic components other than the conductive polymer. In other words, the antistatic component contained in the above-mentioned top coat layer may include only a conductive polymer.

Examples of the organic conductive material include cationic antistatic agents having cationic functional groups such as quaternary ammonium salts, pyridinium salts, first amine groups, second amine groups, and third amine groups; Anions of anionic functional groups such as sulfate salts, phosphonate salts, and phosphate ester salts Sub-type antistatic agent; zwitterionic antistatic agent such as alkyl betaine and its derivatives, imidazoline and its derivatives, alanine and its derivatives; amine alcohol and its derivatives, glycerin and its derivatives, poly Nonionic antistatic agents such as ethylene glycol and its derivatives; ions obtained by polymerizing or copolymerizing monomers having the above-mentioned cationic, anionic, and zwitterionic ion conductive groups (such as quaternary ammonium salt groups) Conductive polymers; conductive polymers such as polythiophene, polyaniline, polypyrrole, polyethylenimine, and allylamine-based polymers; etc. These antistatic agents may be used alone or in combination of two or more.

Examples of the inorganic conductive substance include tin oxide, antimony oxide, indium oxide, cadmium oxide, titanium oxide, zinc oxide, indium, tin, antimony, gold, silver, copper, aluminum, nickel, chromium, titanium, iron, Cobalt, copper iodide, ITO (indium oxide/tin oxide), ATO (antimony oxide/tin oxide), etc. These inorganic conductive substances may be used alone or in combination of two or more.

Examples of the antistatic agent include cationic antistatic agents, anionic antistatic agents, zwitterionic antistatic agents, nonionic antistatic agents, and ionic conductive agents having the above cationic, anionic, and zwitterionic types. Ion-conducting polymer obtained by polymerizing or copolymerizing monomers with a sex group.

<adhesive>

The above-mentioned top coat is characterized by containing a polyester resin as a binder as an essential component. The above-mentioned polyester resin is a resin material containing polyester as a main component (typically, it accounts for more than 50% by mass, preferably 75% by mass or more, for example, 90% by mass or more). The above-mentioned polyester is typically preferably selected from a polycarboxylic acid system (typically a dicarboxylic acid system) having two or more carboxyl groups in one molecule and its derivative (anhydride or esterified product of the polycarboxylic acid) , Acyl halide, etc.), one or two or more compounds (polycarboxylic acid components) and one or two selected from polyols (typically diols) with two or more hydroxyl groups in one molecule A structure formed by condensation of more than one compound (polyol component).

Examples of compounds that can be used as the above-mentioned polycarboxylic acid component include oxalic acid, Malonic acid, difluoromalonic acid, alkylmalonic acid, succinic acid, tetrafluorosuccinic acid, alkylsuccinic acid, (±)-malic acid, mesotartaric acid, itaconic acid, maleic acid, methyl formic acid Base maleic acid, fumaric acid, methyl fumaric acid, acetylenedicarboxylic acid, glutaric acid, hexafluoroglutaric acid, methylglutaric acid, glutaric acid, adipic acid, dithioadipic acid , Methyl adipic acid, dimethyl adipic acid, tetramethyl adipic acid, methylene adipic acid, adipic acid, galactaric acid, pimelic acid, suberic acid, perfluorooctyl Diacid, 3,3,6,6-tetramethyl suberic acid, azelaic acid, sebacic acid, perfluorosebacic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, Aliphatic dicarboxylic acids such as hexadecanedioic acid; cycloalkyl dicarboxylic acids (for example, 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid), 1,4-(2- (Norbornene) dicarboxylic acid, 5-norbornene-2,3-dicarboxylic acid (Nadic acid), adamantane dicarboxylic acid, spiroheptane dicarboxylic acid and other alicyclic dicarboxylic acids; phthalic acid, m Phthalic acid, dithioisophthalic acid, methylisophthalic acid, dimethylisophthalic acid, chloroisophthalic acid, dichloroisophthalic acid, terephthalic acid, methyl terephthalic acid Formic acid, dimethyl terephthalic acid, chloroterephthalic acid, bromoterephthalic acid, naphthalene dicarboxylic acid, oxyfluorene dicarboxylic acid, anthracene dicarboxylic acid, diphthalic acid, biphenylene dicarboxylic acid, dimethyl dicarboxylic acid Phthalic acid, 4,4"-p-phenylene dicarboxylic acid, 4,4"-p-terephthalic acid, bibenzyl dicarboxylic acid, azophthalic acid, homophthalic acid, phenylenedicarboxylic acid Acetic acid, phenylenedipropionic acid, naphthalene dicarboxylic acid, naphthalene dipropionic acid, biphenyl diacetic acid, biphenyl dipropionic acid, 3,3'-[4,4'-(methylene di-p-biphenyl) di Propionic acid], 4,4'-bibenzyl diacetic acid, 3,3'-(4,4'-bibenzyl) dipropionic acid, oxydi-p-phenylene diacetic acid and other aromatic dicarboxylic acids; above Anhydride of any kind of polycarboxylic acid; ester of any one of the above polycarboxylic acids (for example, alkyl esters, which can be monoesters, diesters, etc.); halides corresponding to any of the above polycarboxylic acids (for example, dicarboxylic acid amides) Chlorine); etc.

Preferred examples of the compound usable as the above-mentioned polycarboxylic acid component include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalene dicarboxylic acid and their anhydrides; adipic acid and sebacic acid , Azelaic acid, succinic acid, fumaric acid, maleic acid, nadic acid, 1,4-cyclohexanedicarboxylic acid and other aliphatic dicarboxylic acids and their anhydrides; and the lower dicarboxylic acids Alkyl esters (for example, esters with a monohydric alcohol having 1 to 3 carbon atoms), etc.

On the other hand, examples of compounds that can be used as the polyol component include ethylene glycol, propylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, and 1,4-. Butylene glycol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 3-methylpentanediol, diethylene glycol, 1,4-cyclohexanedimethanol, 3- Methyl-1,5-pentanediol, 2-methyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3- Glycols such as propylene glycol, benzenedimethanol, hydrogenated bisphenol A, and bisphenol A. As other examples, alkylene oxide adducts of these compounds (for example, ethylene oxide adducts, propylene oxide adducts, etc.) may be mentioned.

The molecular weight of the polyester resin may be, for example, about 5×10 ³ to 1.5×10 ^{5 in terms} of weight average molecular weight (Mw) in terms of standard polystyrene measured by gel permeation chromatography (GPC) (preferably 1×10 ⁴ ~6×10 ⁴ or so). In addition, the glass transition temperature (Tg) of the polyester resin may be, for example, 0°C to 120°C (preferably 10°C to 80°C).

As the above-mentioned polyester resin, a commercial name "Vylonal" manufactured by Toyobo Corporation can be used.

To the extent that it does not significantly impair the performance of the adhesive sheet disclosed here (such as antistatic properties and the like), the above-mentioned top coat layer may further contain resins other than polyester resins (such as acrylic resins, acrylic- One of urethane resin, acrylic-styrene resin, acrylic-polysiloxane resin, polysiloxane resin, polysilazane resin, polyurethane resin, fluororesin, polyolefin resin, etc. or Two or more resins) as a binder. As a preferred aspect of the technique disclosed here, it is the case where the binder of the top coat layer essentially contains only polyester resin. For example, a top coat in which the proportion of polyester resin in the binder is 98 to 100% by mass is preferred. The proportion of the adhesive in the entire topcoat layer can be set to, for example, 50 to 95% by mass, and usually set to 60 to 90% by mass.

<Lubricant>

It is preferable that the fatty acid amide is used as a lubricant in the topcoat in the technique disclosed here. By using fatty amide as a lubricant, even if the surface of the top coat layer is not subjected to further peeling treatment (for example, applying a silicone-based peeling agent, a long-chain alkyl-based peeling agent, etc. In the aspect of a well-known peeling treatment agent and drying treatment), a top coat that takes into account sufficient lubricity and printing adhesion can also be obtained, so it can be a better aspect. In this way, if no further peeling treatment is performed on the surface of the top coat, the whitening caused by the peeling treatment agent (for example, whitening caused by storage under heating and humidification conditions) can be prevented from occurring in the future. good. In addition, it is more advantageous in terms of solvent resistance.

As specific examples of the above-mentioned fatty amides, lauramide, palmamide, stearylamide, behenamide, hydroxystearylamide, oleamide, erucamide, N-oleyl palmitate Acetamide, N-stearyl stearamide, N-stearyl oleamide, N-oleyl stearamide, N-stearyl mustardamide, hydroxymethyl stearylamide, sub Methyl bis-stearyl amide, ethyl bis-decyl amide, ethyl bis-lauryl amide, ethyl bis-stearyl amide, ethyl bis-hydroxy-stearyl amide, ethyl bis-stilbene amide Amine, hexamethylene bis-stearyl amide, hexamethylene bis-behenamide, hexamethylene bis-hydroxy stearyl amide, N,N'-distearyl adipate amide, N, N'-distearyl sebacate amide, ethyl bis oleamide, ethyl bis erucamide, hexamethylene bis oleamide, N,N'-dioleyl adipic acid Acetamide, N,N'-dioleyl sebacate diacrylamide, m-xylylenedimethylene bisstearylamide, m-xylylenedimethylene bishydroxystearamide, N,N'-di Stearyl diisocyanate, etc. These lubricants can be used alone or in combination of two or more.

The proportion of the lubricant in the entire topcoat layer can be set to 1 to 50% by mass, usually 5 to 40% by mass is more appropriate. If the content of the lubricant is too small, the lubricity tends to decrease. If the content of lubricant is too large, the adhesion of printing may be reduced.

The technique disclosed here can be implemented in a state where the top coat contains other lubricants in addition to the above-mentioned fatty amides, within a limit that does not significantly impair its application effect. Examples of the other lubricants mentioned above include various waxes such as petroleum waxes (paraffin wax, etc.), mineral waxes (montan wax, etc.), higher fatty acids (waxic acid, etc.), neutral fats (glycerin tripalmitate, etc.). Alternatively, in addition to the above waxes, general silicone lubricants and fluorine Lubricants, etc. The technique disclosed here can be preferably implemented without substantially containing the above-mentioned silicone lubricant, fluorine lubricant, or the like. However, to the extent that it does not significantly impair the application effect of the technology disclosed herein, it does not exclude the inclusion of polysilicon used for purposes other than lubricants (for example, as a defoamer for the composition for topcoat described below) Oxygen compounds.

<crosslinking agent>

The above-mentioned top coat layer is characterized by containing an isocyanate-based cross-linking agent as a cross-linking agent. By using the isocyanate-based cross-linking agent, water-soluble polyaniline sulfonic acid as an essential component can be immobilized in the adhesive when forming the topcoat layer, and effects such as excellent water resistance and improved printing adhesion can be achieved.

In addition, a preferred aspect is to use a blocked isocyanate-based crosslinking agent that is stable in an aqueous solution as the isocyanate-based crosslinking agent. As specific examples of the blocked isocyanate-based crosslinking agent, alcohols, phenols, thiophenols, amines, amide imines, oximes, lactams, active methylene compounds can be used , Thiols, imines, ureas, diaryl compounds, sodium bisulfite and other isocyanate-based crosslinking agents that can be used in the preparation of general adhesive layers or topcoats (for example, the following adhesive The isocyanate compound (isocyanate-based crosslinking agent) used in the agent layer is blocked and obtained.

The topcoat in the technology disclosed here may contain antioxidants, colorants (pigments, dyes, etc.), fluidity modifiers (thixotropic agents, thickeners, etc.), film-forming aids, surfactants ( Anti-foaming agents, etc.), preservatives, ultraviolet absorbers, dispersants, anti-blocking agents and other additives.

<Formation of top coat>

The above-mentioned top coat layer can be suitably used as a liquid composition (composition for top coat layer) including essential components such as the above-mentioned conductive polymer component and additives used as needed in a suitable solvent (water, etc.) Formed by the method applied to the resin layer. For example, a method of applying the above composition for top coat to the first surface of the resin layer and drying it, and performing hardening treatment (heat treatment, ultraviolet treatment, etc.) as necessary. For top coating The NV (nonvolatile content) of the composition may be, for example, 5 mass% or less (typically 0.05 to 5 mass%), and usually 1 mass% or less (typically 0.10 to 1 mass%). In the case of forming a top coat with a small thickness, it is preferable to set the NV of the top coat composition to, for example, 0.05 to 0.50% by mass (for example, 0.10 to 0.40% by mass). By using such a low NV composition for topcoat, a more uniform topcoat can be formed.

As a solvent constituting the above-mentioned composition for top coat (coating material for forming a top coat), it is preferable to be capable of stably dissolving the forming component of the top coat. The above solvent may be an organic solvent, water, or a mixed solvent of these. As the organic solvent, for example, esters selected from ethyl acetate; ketones such as methyl ethyl ketone, acetone, and cyclohexanone; cyclic ethers such as tetrahydrofuran (THF) and dioxane; n-hexyl Aliphatic or alicyclic hydrocarbons such as alkanes and cyclohexane; aromatic hydrocarbons such as toluene and xylene; aliphatic or alicyclic alcohols such as methanol, ethanol, n-propanol, isopropanol and cyclohexanol; Alkyl glycol monoalkyl ethers (eg ethylene glycol monomethyl ether, ethylene glycol monoethyl ether), dialkylene glycol monoalkyl ethers and other glycol ethers; one or more of them. In a preferred aspect, the solvent of the composition for a top coat is water or a mixed solvent containing water as a main component (for example, a mixed solvent of water and ethanol).

<Properties of Topcoat>

The thickness of the top coat in the technology disclosed here is typically 3 nm to 500 nm, preferably 10 nm to 100 nm, and more preferably 20 nm to 60 nm. If the thickness of the topcoat layer is too small, it is difficult to form a topcoat layer uniformly (for example, the thickness of the topcoat layer varies depending on the location, and the difference in thickness increases), so the appearance of the adhesive sheet may be easily generated Uneven. On the other hand, if the thickness is too thick, it may affect the characteristics (optical characteristics, dimensional stability, etc.) of the resin layer.

In a preferred aspect of the adhesive sheet disclosed herein, the surface resistivity (Ω/□) measured on the surface of the top coat is preferably less than 1.0×10 ¹¹ , more preferably less than 5.0×10 ¹⁰ It is further preferably less than 1.5×10 ¹⁰ . The adhesive sheet showing the surface resistivity within the above range can be suitably used as an adhesive sheet for processing or transporting articles that avoid static electricity, such as liquid crystal cells or semiconductor devices. Furthermore, the above-mentioned surface resistivity can be calculated from the surface resistivity measured using a commercially available insulation resistance measuring device under an atmosphere of 23° C. and 50% RH.

The adhesive sheet disclosed herein preferably has a property that the back surface (surface of the top coat) can be easily printed using water-based ink or oil-based ink (for example, using an oil-based marker). The above-mentioned adhesive sheet is suitable for describing the identification number of the adherend to be protected, etc. in the above-mentioned adhesive sheet during the processing or transportation of the adherend (e.g., optical component) in the state where the adhesive sheet is attached Go up and display. Therefore, an adhesive sheet excellent in printability is preferred. For example, it is preferable to have high printability for oil-based inks in which the solvent is an alcohol and contains pigments. In addition, it is preferable that the ink after printing is not easily removed by scratching or transfer (that is, the printing adhesion is excellent). The adhesive sheet disclosed herein preferably has solvent resistance to such an extent that it does not cause a significant change in the appearance of the printing even when alcohol (such as ethanol) is used to wipe the printing when correcting or eliminating the printing.

The adhesive sheet disclosed herein can be implemented in a manner that it includes other layers in addition to the resin layer, the adhesive layer, the adhesive layer, and the top coat. As the arrangement of the "other layers", the first resin layer between the first surface (back surface) and the topcoat layer, the second resin layer between the second surface (front surface) and the adhesive layer, etc. can be exemplified. The layer disposed between the back surface of the first resin layer and the top coat layer may be, for example, a layer containing an antistatic component (the above top coat layer). The layer disposed between the front surface of the second resin layer and the adhesive layer may be, for example, an undercoat layer (anchor layer) or a topcoat layer that improves the anchorability of the adhesive layer to the second surface. It may be an adhesive sheet composed of a topcoat layer disposed on the front surface of the second resin layer, an anchor layer disposed on the topcoat layer, and an adhesive layer disposed thereon.

The optical member of the present invention is preferably protected by the above-mentioned adhesive sheet. The above-mentioned adhesive sheet is excellent in antistatic property, pick-up property, etc., so it can be used for surface protection applications (adhesive sheet) during processing, transportation, shipping, etc., and is more useful for protecting the surface of the above optical member (polarizing plate, etc.) . In particular, it can be used for plastic products that are prone to static electricity. It is a very serious problem in the technical field related to optical and electronic parts, and is very useful in antistatic applications.

In addition, the total thickness of the adhesive sheet of the present invention is preferably 14 μm to 400 μm, more preferably 40 μm to 200 μm, and most preferably 55 μm to 100 μm. Within the above range, the adhesive properties (repeelability, adhesiveness, etc.), workability, and appearance characteristics are excellent, which is a preferable aspect. Furthermore, the above-mentioned total thickness refers to the total thickness of all layers including the resin layer, the adhesive layer, the adhesive layer, and the top coat layer.

[Example]

Hereinafter, some embodiments related to the present invention will be described, but it is not intended to limit the present invention to the contents shown in the above specific examples. In addition, in the following description, unless otherwise stated, "parts" and "%" are quality standards.

In addition, each characteristic in the following description is measured or evaluated as follows.

<Measurement of weight average molecular weight (Mw)>

The weight average molecular weight (Mw) was measured using a GPC device (HLC-8220GPC) manufactured by Tosoh Corporation. The measurement conditions are as follows.

Sample concentration: 0.2% by mass (THF solution)

Sample injection volume: 10μl

Dissolution solution: THF

Flow rate: 0.6ml/min

Measuring temperature: 40℃

Column:

Sample column: TSKguardcolumn SuperHZ-H (1 piece) + TSKgel SuperHZM-H (2 pieces)

Reference column: TSKgel SuperH-RC (1 piece)

Detector: Differential Refractometer (RI)

In addition, the weight-average molecular weight is calculated using polystyrene conversion values.

<glass transition temperature (Tg)>

The glass transition temperature Tg (°C) was determined by the following formula using the following literature value as the glass transition temperature Tgn (°C) of the homopolymer of each monomer.

Formula: 1/(Tg+273)=Σ[Wn/(Tgn+273)] [In the formula, Tg(℃) represents the glass transition temperature of the copolymer, Wn(-) represents the weight fraction of each monomer, Tgn (°C) represents the glass transition temperature of the homopolymer of each monomer, and n represents the type of each monomer].

Literature value:

2-Ethylhexyl acrylate (2EHA): -70℃

N-butyl acrylate (BA): -55℃

2-Hydroxyethyl acrylate (HEA): -15℃

Acrylic acid (AA): 106℃

In addition, as literature values, refer to "Synthesis, Design, and New Use Prospects of Acrylic Resins" (published by the Central Business Development Center Publishing Department), "Polymer Handbook" (John Wiley & Sons), and monomer manufacturer catalog values.

In addition, the glass transition temperature (Tg) (°C) of the (meth)acrylic polymer obtained from a monomer whose literature value is unknown is determined by dynamic viscoelasticity measurement using the following procedure.

7.9mm，製作圓柱狀之顆粒，作為玻璃轉移溫度(Tg)測定用樣品。 First, the (meth)acrylic polymer sheet with a thickness of 20 μm is laminated to a thickness of about 2 mm, and the resulting object is punched out as

At 7.9mm, cylindrical particles were prepared and used as samples for measuring the glass transition temperature (Tg).

7.9mm平行板夾具上，利用動態黏彈性測定裝置(Rheometrics公司製造，ARES)測定損耗彈性模量G"之溫度依賴性，將所獲得之G"曲線達到極大時之溫度作為玻璃轉移溫度(Tg)(℃)。測定條件如下所述。 Using the above measurement sample, the above measurement sample is fixed to

On a 7.9mm parallel plate fixture, the temperature dependence of the loss elastic modulus G" was measured using a dynamic viscoelasticity measuring device (manufactured by Rheometrics, ARES), and the temperature at which the obtained G" curve reached the maximum was taken as the glass transition temperature (Tg )(℃). The measurement conditions are as follows.

Measurement: shear mode

Temperature range: -70℃~150℃

Heating rate: 5℃/min

Frequency: 1Hz

<thickness measurement>

A digital micrometer (manufactured by Anritsu, product name "KC-351C") was used for measurement.

<Tensile strength of resin layer>

According to JIS C 2318, the measurement was performed using a tensile tester (manufactured by Shimadzu Corporation, product name "Autograph").

<Storage elastic modulus of the next layer>

7.9mm，製作圓柱狀之顆粒並將其作為測定用樣品。使用上述測定用樣品，將上述測定用樣品固定於

7.9mm平行板夾具上，使用動態黏彈性測定裝置(Rheometrics公司製造，ARES)，測定23℃下之儲存彈性模數G'。測定條件如下所述。 The next layer is laminated to a thickness of about 2mm, and the resulting object is punched into

7.9 mm, making cylindrical particles and using them as samples for measurement. Using the above measurement sample, the above measurement sample is fixed to

Using a dynamic viscoelasticity measuring device (manufactured by Rheometrics, ARES) on a 7.9mm parallel plate jig, the storage elastic modulus G'at 23°C was measured. The measurement conditions are as follows.

Measurement: shear mode

Frequency: 1Hz

The storage elastic modulus (23°C) of the adhesive layer in the present invention is 1.0×10 ⁴ Pa or more and less than 5.0×10 ⁷ Pa, preferably 1.0×10 ⁴ Pa or more and less than 1.0×10 ⁷ Pa It is more preferably 1.0×10 ⁵ Pa or more and less than 1.0×10 ⁶ Pa. If it is within the above range, the pick-up property of the adhesive sheet is good, which is a preferable aspect.

<Measurement of surface resistivity>

Under an atmosphere of a temperature of 23° C. and a humidity of 50% RH, a resistivity meter (manufactured by Mitsubishi Chemical Analytech, Hiresta UP MCP-HT450 type) was used for measurement in accordance with JIS K 6911.

In addition, as the surface resistivity (Ω/□) in the present invention, the initial and the case of standing at room temperature (RT) (23°C×50%RH)×1 week (7 days) are preferably not Up to 1.0×10 ¹¹ , more preferably less than 5.0×10 ¹⁰ , and even more preferably less than 1.5×10 ¹⁰ . The adhesive sheet showing the surface resistivity within the above range can be suitably used as an adhesive sheet for processing or transporting articles that avoid static electricity, such as liquid crystal cells or semiconductor devices, for example.

<Measurement of peeling electrostatic voltage (on polarizing plate side)>

The adhesive sheet 1 of each example was cut to a size of 70 mm in width and 130 mm in length, and after peeling off the release liner, as shown in FIG. 2, it was pressed onto the acrylic resin plate 3 by manual roller pressure bonding after pre-discharge. On the surface of polarizer 2 (made by Nitto Denko Corporation, SEG1423DU polarizer, width: 70mm, length: 100mm) on the surface of polarizing plate 2 (made by Nitto Denko Corporation, product name "ACRYLITE", thickness: 1mm, width: 70mm, length: 100mm) So that the single end of the adhesive sheet 1 protrudes 30 mm from the edge of the polarizing plate 2.

After the sample was placed in an environment of 23° C.×50% RH for 1 day, it was set at a specific position of the sample fixing table 4 with a height of 20 mm. The end of the adhesive sheet 1 that protruded from the polarizing plate 2 by 30 mm was fixed to an automatic winder (not shown), and peeled at a peeling angle of 150° and a peeling speed of 10 m/min. Use the potentiometer 5 (made by Kasuga Electric Co., Ltd., model "KSD-0103") fixed at a height of 100 mm from the center of the polarizing plate 2 to measure the potential of the surface of the adherend (polarizing plate) generated at this time as the "initial The polarizing plate peels off the static voltage." The measurement was carried out in an environment of 23°C and 50% RH.

The peeling electrostatic voltage (kV) (absolute value) in the present invention is preferably 1 or less, more preferably 0.9 or less, and still more preferably 0.5 or less. Within the above range, for example, it is possible to prevent damage to the liquid crystal driver, which is a preferable aspect.

<Measurement of back adhesion (A)>

As shown in FIG. 3, the adhesive sheet 1 of each example is cut into a size of 70 mm in width and 100 mm in length, and the adhesive surface (the side where the adhesive layer 20 is provided) 20A of the adhesive sheet 1 is double-sided adhesive tape 130 Fixed on SUS304 stainless steel plate 132. A single-sided adhesive tape (made by Nitto Denko Corporation, product name "No.31B") with a single-sided adhesive tape (made by Nitto Denko Corporation) on resin layer film (in the order of first resin layer, adhesive layer, and second resin layer) 164 19mm) 160 cut to a length of 100mm. Place the adhesive surface 162A of the adhesive tape 160 at 0.25 Under pressure of MPa and speed of 0.3 m/min, it is pressure-bonded to the back surface of the adhesive sheet 1 (that is, the surface of the top coat 14) 1A. The resulting object was left at 23°C and 50% RH for 30 minutes. Then, using a universal tensile testing machine, the adhesive tape 160 was peeled from the back surface 1A of the adhesive sheet 1 under the conditions of a peeling speed of 0.3 m/min and a peeling angle of 180 degrees, and the adhesion (A)[N/ 19mm].

In addition, the back surface adhesive force (A) is preferably 3.0 N/19 mm or more, more preferably 4.0 N/19 mm or more, still more preferably 5.0 N/19 mm or more, and most preferably 6.0 N/19 mm or more. If the above-mentioned adhesive force does not reach 3.0 N/19 mm, sufficient adhesive force cannot be obtained, the pick-up property is deteriorated, and the peeling workability of the protective film is reduced, which is not good.

<Measurement of adhesion to polarizing plate (B)>

Prepare a plane polarizer with a width of 70 mm and a length of 100 mm (TAC polarizer manufactured by Nitto Denko Corporation, SEG1425DU) as the adherend. The adhesive sheet of each example was cut into a size of 25 mm in width and 100 mm in length, and its adhesive surface was pressure-bonded to the polarizing plate under the conditions of a pressure of 0.25 MPa and a speed of 0.3 m/min. After the resulting object was placed in an environment of 23°C and 50% RH for 30 minutes, the adhesive sheet was peeled from the above under the conditions of a peeling speed of 0.3 m/min and a peeling angle of 180° using a universal tensile testing machine. The polarizing plate was peeled off, and the adhesion (B) [N/25mm] at this time was measured.

In addition, the adhesive force (B) is preferably 2.5 N/25 mm or less, more preferably 2.0 N/25 mm or less, further preferably 1.5 N/25 mm or less, and particularly preferably 1.0 N/25 mm or less. If the above adhesive force exceeds 2.5 N/25 mm, the peeling workability is poor, so it is not good.

<pickup>

As shown in FIG. 4, the adhesive sheet 1 of each example is cut into a size of 50 mm in width and 100 mm in length, and the adhesive surface (the side where the adhesive layer 20 is provided) 20A of the adhesive sheet 1 is pressed at a pressure of 0.25 MPa. The speed of 0.3m/min is crimped onto the plane polarizing plate (TAC polarizing plate made by Nitto Denko Corporation, SEG1425DU) 50.

The single-sided adhesive tape 60 (manufactured by Nitto Denko Corporation, trade name "No. 31B", width 19 mm) was cut into a width of 10 mm and a length of 50 mm. The adhesive layer (adhesive surface) 62 of the adhesive tape 60 is pressed against the center of the back surface of the adhesive sheet 1 with a width of 50 mm (that is, the surface of the top coat layer 14) by hand so that the end portion protrudes by 30 mm. The resulting object was placed under the conditions of 23°C and 50% RH for 10 seconds. Then, the single-sided adhesive tape 60 was peeled off by hand, and the peeling state (pickability) of the adhesive sheet 1 was evaluated.

The evaluation criteria evaluated the case where the adhesive sheet can be peeled off as ○, and the case where the adhesive sheet cannot be peeled off and the adhesive sheet remains as ×.

<deflection amount>

As shown in FIG. 5, the adhesive sheet 1 of each example was cut into a size of 20 mm in width and 150 mm in length, and the end of the adhesive sheet 1 was oriented outward using No. 31B tape T manufactured by Nitto Denko Corporation. The part is fixed on the glass plate G. The height H1 of the center position of the adhesive sheet at this time was measured. Then, place a load L of 4.8 g at the center position, and measure the height H2 of the center position of the adhesive sheet at this time. The amount of deflection [mm] is obtained from the following formula.

Deflection = H1-H2 [mm]

Furthermore, the amount of deflection is preferably 30 mm or less, more preferably 25 mm or less, and still more preferably 20 mm or less. If the above-mentioned deflection amount exceeds 30 mm, the optical member to which the adhesive sheet is attached is likely to deflect during transportation, which is not good.

<Evaluation of printability (printing adhesion)>

After printing on the surface of the top coat using the X stamper manufactured by Atomic Seal Company under the measurement environment of 23°C×50%RH, attach Cellotape (registered trademark) manufactured by Michelbon from the top of the printing, and then , Peeling under the condition of peeling speed 30m/min and peeling angle 180°. Then, the surface after peeling was visually observed, and the case where 50% or more of the printing area was peeled off was evaluated as × (poor printability), and the case where 50% or more of the printing area was left without peeling off was evaluated as ○ (good printability) ).

Hereinafter, the top coat, the adhesive composition (adhesive solution), and the adhesive sheet (table Face protective film) preparation method.

[Example 1] <Preparation of resin layer film (order of first resin layer, adhesive layer and second resin layer)>

100 parts by mass of butyl acrylate (BA), 5.0 parts by mass of acrylic acid (AA), 0.075 parts by mass of 2-hydroxyethyl acrylate (2HEA), 2 0.3 mass parts of 2'-azobisisobutyronitrile and ethyl acetate were reacted at 60°C for 6 hours while stirring under a nitrogen gas flow, thereby obtaining an acrylic polymer solution having a weight average molecular weight of 1.63 million. With respect to 100 parts by mass of the polymer solid content of the acrylic polymer solution, 0.6 parts by mass of an isocyanate-based polyfunctional compound (manufactured by Japan Polyurethane Industry Co., Ltd., trade name "Coronate L") and a silane coupling agent (Shin-Etsu Chemical Industry Co., Ltd.) were added. Manufactured, trade name: KBM403) 0.08 parts by mass to prepare an acrylic adhesive 1 composition solution.

A polyester resin film (manufactured by Toyobo Co., Ltd., trade name: E5000, thickness: 38 μm, tensile strength: 208 MPa) as a resin layer was coated with the above adhesive composition solution and heated at 90° C. to form a thickness Adhesive layer of 20μm. The storage elastic modulus of the obtained adhesive layer at 23° C. was 1.0×10 ⁵ Pa.

Then, a polyester resin film (manufactured by Toyobo Co., Ltd., trade name: E5000, thickness: 38 μm, tensile strength: 208 MPa) was laminated on the adhesive layer to obtain a resin layer film having a thickness of 96 μm.

<Preparation of Acrylic Adhesive 1 Solution>

Put 95 parts by mass of 2-ethylhexyl acrylate (2EHA) and 5 parts by mass of 2-hydroxyethyl acrylate (HEA) into a four-necked flask equipped with a stirring blade, thermometer, nitrogen introduction tube, and cooler as the polymerization start 0.22 parts by mass of 2,2'-azobisisobutyronitrile and 150 parts by mass of ethyl acetate, nitrogen gas was introduced while slowly stirring, and the liquid temperature in the flask was kept near 65°C and polymerization reaction was carried out for 6 hours, A (meth)acrylic polymer solution (40% by mass) was prepared. The weight average molecular weight of the above acrylic polymer is 550,000, and the glass transition temperature The degree (Tg) is -68°C.

The (meth)acrylic polymer solution (40% by mass) was diluted with ethyl acetate to 20% by mass, and 500 parts by mass of the solution (100 parts by mass of solid content) was added as an antistatic agent with oxygen Alkyl chain organic polysiloxane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KF-6020, HBL: 4) 0.1 parts by mass (solid content 0.1 parts by mass), hexamethylene diisocyanate as a crosslinking agent Isocyanurate form (made by Japan Polyurethane Industry Co., Ltd., trade name: Coronate HX (C/HX)) 3 parts by mass (solid content 3 parts by mass), dibutyltin dilaurate (1 mass) as a crosslinking catalyst % Ethyl acetate solution) 2 parts by mass (solid content 0.02 parts by mass), and the mixture was stirred to prepare an acrylic adhesive 1 solution.

<Preparation of solution for top coat (top coat 1)>

Polyester resin Vylonal MD-1480 (25% aqueous solution, manufactured by Toyobo Co., Ltd.) as a binder, polyaniline sulfonic acid (aqua-PASS, weight average molecular weight of 40,000, manufactured by Mitsubishi Rayon) as a conductive polymer, As isocyanurate of hexamethylene diisocyanate blocked with diisopropylamine as a crosslinking agent, oleamide as a lubricant is added to a mixed solvent of water/ethanol (1/3), added with 100 parts by mass of binder based on the solid content, 75 parts by mass of conductive polymer based on the solid content, 10 parts by mass of crosslinking agent based on the solid content, and 30 parts by mass based on the solid content The lubricant, and stir for about 20 minutes to fully mix. In this way, a solution for topcoat with NV of about 0.4% (topcoat 1) was prepared.

<Preparation of the resin layer film with topcoat (the order of topcoat, first resin layer, adhesive layer and second resin layer)>

One side of the resin layer film was subjected to corona treatment, and the solution for the top coat was applied to the corona treated surface so that the thickness after drying was 30 nm. The coated material was heated at 130° C. for 1 minute and dried to prepare a resin layer film with a top coat (the order of top coat, first resin layer, adhesive layer, and second resin layer).

<Production of adhesive sheet (surface protective film)>

Apply the above acrylic adhesive solution to the surface of the resin layer film of the top coat (the order of top coat, first resin layer, adhesive layer, and second resin layer) opposite to the top coat, on Heat at 130°C for 1 minute to form an adhesive layer with a thickness of 20 μm. Then, a polysiloxane-treated surface of a polyethylene terephthalate film (thickness 25 μm) as a separator, which was subjected to polysiloxane treatment on one side, was bonded to the surface of the above adhesive layer to produce an adhesive sheet (surface Protective film).

[Example 5] <Preparation of Polyurethane Adhesive Solution>

100 parts by mass of PREMINOL S3015 (manufactured by Asahi Glass Co., Ltd., Mn=15000) which is a polyol having three hydroxyl groups (OH groups) as a polyol, and trimethylolpropane/toluene diisocyanate 3 as a multifunctional isocyanate compound Polymer adduct (manufactured by Japan Polyurethane Industry Co., Ltd., trade name: Coronate L) 13 parts by mass, organic polysiloxane having an oxyalkylene chain (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KF-6004, HLB: 9 ) 0.1 parts by mass, catalyst (manufactured by Nippon Chemical Industry Co., Ltd., trade name: ferrous Nasem) 0.04 parts by mass, 210 parts by mass of ethyl acetate as a dilution solvent, stirred in a disperser to obtain amino acid Ester adhesive composition (solution).

<Production of adhesive sheet (surface protective film)>

Apply the above-mentioned urethane-based adhesive solution to the resin layer film of the above-mentioned top coat (the order of top coat, first resin layer, adhesive layer, and second resin layer) opposite to the top coat On the surface, it was heated at 130°C for 1 minute to form an adhesive layer with a thickness of 20 μm. Then, a polysiloxane-treated surface of a polyethylene terephthalate film (thickness 25 μm) as a separator, which was subjected to polysiloxane treatment on one side, was bonded to the surface of the above adhesive layer to produce an adhesive sheet (surface Protective film).

[Comparative Example 1] <Preparation of solution for top coat (top coat 3)>

Polyester resin Vylonal MD-1480 (25% aqueous solution, manufactured by Toyobo Co., Ltd.) as a binder, and 0.5% poly(3,4-ethylenedioxythiophene) (PEDOT) and 0.8% as a conductive polymer An aqueous solution of polystyrene sulfonate (weight average molecular weight 150,000) (PSS) (Baytron P, manufactured by HC Stark) was added to a mixed solvent of water/ethanol (1/1), and 100 was added based on the amount of solid content. Mass parts of the binder, 50 parts by mass of the conductive polymer based on the solid content, and 5 parts by mass of the melamine-based cross-linking agent are stirred and mixed for about 20 minutes. In this way, a solution for topcoat with NV of about 0.4% (topcoat 3) was prepared.

[Comparative Example 3] <Preparation of solution for top coat (top coat 5)>

Prepared in a water-alcohol solvent, based on NV with an antistatic agent (manufactured by Konishi Co., Ltd., trade name "BONDEIP-P main agent") containing a cationic polymer at a mass ratio of 100:46.7 and as a hardener Topcoat solution (topcoat 5) of epoxy resin (manufactured by Konishi Corporation, trade name "BONDEIP-P hardener").

Corona treatment was performed on one side of the resin layer film of the composition shown in Table 4, and the above-mentioned topcoat solution (topcoat 5) was applied on the corona-treated surface so that the thickness after drying was 60 nm at 130 It was heated at ℃ for 1 minute and dried to form a top coat. Then, apply a long-chain alkyl carbamate-based peeling treatment agent (product of Yipiso Oil & Gas Industry Co., Ltd., trade name "PEELOIL 1010") as a lubricant on the surface of the above-mentioned top coat based on the NV standard It is 40nm, heated at 130°C for 1 minute and dried to form a two-layer topcoat.

[Comparative Example 6] <Preparation of resin layer film (order of first resin layer, adhesive layer and second resin layer)>

30 parts by mass of 2-ethylhexyl acrylate (2EHA), 70 parts by mass of methyl acrylate (MA), and 10 parts by mass of acrylic acid (AA) were added to the reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer, and a stirring device. 2,2'-Azobisisobutyronitrile 0.2 parts by mass and ethyl acetate The ester was reacted at 60°C for 6 hours while stirring under a nitrogen gas flow, thereby obtaining an acrylic polymer solution having a weight average molecular weight of 1.1 million. To 100 parts by mass of the polymer solid content of the acrylic polymer solution, 1.0 part by mass of an epoxy compound [Mitsubishi Gas Chemical Co., Ltd., TETRAD-C], urethane acrylate compound [Nippon Synthetic Chemical Industry] is added Made by the company, UV-1700B] 40 parts by mass, acrylate compound [made by Nippon Kayaku, KAYARAD DPCA-120] 40 parts by mass, 1-hydroxycyclohexyl phenyl ketone (trade name: IRGACURE 184) [Cibagen Chemical Co., Ltd.] 7 parts by mass to prepare an acrylic adhesive 2 composition solution.

A polyester resin film (manufactured by Toyobo Co., Ltd., trade name: E5000, thickness: 38 μm, tensile strength: 208 MPa) as a resin layer was coated with the above adhesive composition solution and heated at 90° C. to form Adhesive layer with a thickness of 12 μm.

Then, a polyester resin film (manufactured by Toyobo Co., Ltd., trade name: E5000, thickness: 38 μm, tensile strength: 208 MPa) was laminated on the adhesive layer, and the adhesive layer was irradiated with ultraviolet light at a cumulative light amount of 0.5 J/cm ² using a high-pressure mercury lamp. Hardened to obtain a resin layer film with a thickness of 88 μm. The storage elastic modulus of the obtained adhesive layer at 23° C. was 6.7×10 ⁷ Pa.

[Examples 2-7 and Comparative Examples 1-6]

Based on the formulation contents of Table 1 and Table 2, an adhesive sheet (surface protective film) was produced in the same manner as in Example 1. Furthermore, other additives not prepared in Example 1 (for example, antistatic components formulated during the preparation of the adhesive solution, etc.) are formulated during the preparation of the adhesive solution. In Comparative Example 5, only the second resin layer shown in Table 4 was used instead of the resin layer film. The blending amounts in Table 1 and Table 2 indicate the solid content.

For the adhesive sheets of Examples and Comparative Examples, the above-mentioned various measurements and evaluations were performed. The results are shown in Table 3 and Table 4.

In addition, the abbreviations in Table 1 and Table 2 are explained below.

2EHA: 2-ethylhexyl acrylate

BA: n-butyl acrylate

HEA: 2-hydroxyethyl acrylate

AA: Acrylic

KF352A: Organic polysiloxane with oxyalkylene chain (HLB value: 7) (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KF-352A)

KF353: Organic polysiloxane with oxyalkylene chain (HLB value: 10) (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KF-353)

KF355A: Organic polysiloxane with an oxyalkylene chain (HLB value: 12) (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KF-355A)

KF6004: Organic polysiloxane with an oxyalkylene chain (HLB value: 9) (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KF-6004)

KF6020: Organic polysiloxane with oxyalkylene chain (HLB value: 4) (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KF-6020)

C/HX: isocyanurate form of hexamethylene diisocyanate (manufactured by Japan Polyurethane Corporation, trade name: Coronate HX)

BMP: 1-butyl-3-methylpyridinium bis(trifluoromethanesulfonyl) amide imine (ionic liquid, liquid at 25°C, Wako Pure Chemical Industries, Ltd.)

LiTFSI: Lithium bis(trifluoromethanesulfonyl)imide (alkali metal salt, manufactured by Kishida Chemical Co., Ltd.)

Polyethylene naphthalate resin 12μm: (manufactured by Teijin DuPont, trade name: Teonex Q51, tensile strength: 311MPa)

Polyethylene naphthalate resin 50μm: (manufactured by Teijin DuPont, trade name: Teonex Q51, tensile strength: 272MPa)

Polyester resin 25μm: (manufactured by Teijin DuPont, trade name: G2, tensile strength: 261MPa)

Polyester resin 38μm: (manufactured by Toyobo, trade name: E5000, tensile strength: 208MPa)

Polyester resin 75μm: (manufactured by Toyobo, trade name: E5000, tensile strength: 188MPa)

Polycarbonate resin 65 μm: (manufactured by Kaneka, trade name: ELMECH, tensile strength: 105 MPa)

From the above evaluation results, it can be confirmed that, in all the examples, by using an adhesive sheet having a required thickness ratio, or a storage elastic modulus of the adhesive layer, an adhesive layer, a top coat, etc., the antistatic property, Excellent adhesion characteristics, pick-up properties, deflection, and printing adhesion. On the other hand, in the comparative example, the desired adhesive sheet having a desired thickness ratio, adhesive layer, top coat, or the like is not used, and therefore, those satisfying all characteristics are not obtained.

[Industry availability]

The adhesive sheet disclosed here is suitable for the manufacture and transportation of optical members used as constituent elements of liquid crystal display panels, plasma display panels (PDP), organic electroluminescence (EL) displays, touch panel displays, etc. Adhesive sheet (surface protective film) for protecting optical components. In particular, it is used as an adhesive sheet for optical members such as polarizing plates (polarizing films), wave plates, retardation plates, optical compensation films, brightness enhancement films, light diffusing sheets, and reflective sheets for liquid crystal display panels (optical Adhesive sheets) are more useful.

1‧‧‧adhesive sheet (surface protective film)

6‧‧‧First resin layer

7‧‧‧Next layer

8‧‧‧Second resin layer

14‧‧‧Top coating

20‧‧‧Adhesive layer

Claims (6)

An adhesive sheet comprising a first resin layer, an adhesive layer, a second resin layer, and an adhesive layer formed of an adhesive composition in sequence, the thickness of the adhesive layer relative to the thickness of the first resin layer The ratio to the sum of the thickness of the second resin layer is 0.50 or less. The storage elastic modulus of the adhesive layer at 23°C is 1.0×10 ⁴ Pa or more and less than 5.0×10 ⁷ Pa. The surface opposite to the surface with the adhesive layer has a topcoat layer consisting of a polyaniline sulfonic acid as a conductive polymer component, a polyester resin as a binder component and a crosslinking agent The composition for the top coat of the isocyanate-based compound, the adhesive composition contains an urethane-based adhesive and an organic polysiloxane having an oxyalkylene chain. The adhesive sheet according to claim 1, wherein the composition for top coating further contains fatty amide as a lubricant. The adhesive sheet according to claim 1, wherein at least one of the above resin layers is a polyester film. The adhesive sheet according to claim 1, wherein the above-mentioned adhesive composition contains an acrylic adhesive. The adhesive sheet according to any one of claims 1 to 4, wherein the above-mentioned adhesive composition contains an antistatic component. An optical member characterized in that it is protected by the adhesive sheet according to any one of claims 1 to 5.

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