KR102476947B1 - Pressure-sensitive adhesive sheet, and optical member - Google Patents

Abstract

A pressure-sensitive adhesive sheet capable of improving antistatic properties and pick-up properties and an optical member protected by the pressure-sensitive adhesive sheet are provided. The pressure-sensitive adhesive sheet of the present invention has a first resin layer, an adhesive layer, a second resin layer, and a pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive composition in this order, the thickness of the first resin layer and the thickness of the second resin layer. The value of the ratio of the thickness of the adhesive layer to the sum of is 0.5 or less, the storage modulus of the adhesive layer at 23 ° C is 1.0 × 10 ⁴ Pa or more and less than 5.0 × 10 ⁷ Pa, and the first resin layer of the first resin layer A top coating layer is formed from a composition for a top coating layer containing polyanilinesulfonic acid as a conductive polymer component, a polyester resin as a binder component, and an isocyanate-based compound as a crosslinking agent. characterized in that it is

Description

Adhesive sheet and optical member {PRESSURE-SENSITIVE ADHESIVE SHEET, AND OPTICAL MEMBER}

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

The adhesive sheet of the present invention is a polarizing plate, a wave plate, a retardation plate, an optical compensation film, a reflective sheet, a luminance enhancing film, a cover glass, a cover sheet, a hard coating film, and a transparent film used in a liquid crystal display, an organic EL display, a touch panel display, and the like. It is useful as a surface protection film used for the purpose of protecting the surface of an optical member such as conductive glass or transparent conductive film.

In recent years, when optical components and electronic components are transported or mounted on a printed circuit board, they are transported in a state in which each component is wrapped in a predetermined sheet or in a state where an adhesive tape is applied. Among them, surface protection films are particularly widely used in the field of optical/electronic components.

A surface protection film is generally bonded to an adherend through an adhesive applied to the support film side, and is used for the purpose of preventing scratches and stains generated during processing and transportation of the adherend (Patent Document 1). For example, the panel of a liquid crystal display is formed by bonding optical members, such as a polarizing plate and a wave plate, to a liquid crystal cell via an adhesive. In these optical members, a surface protection film is bonded through an adhesive, and scratches and stains generated during processing and transportation of adherends are prevented.

And this optical member is bonded to a liquid crystal cell, and a protective film is peeled off and removed at the stage when a protective film became unnecessary. In general, since protective films and optical members are made of plastic materials, they have high electrical insulation properties and generate static electricity during friction or peeling. Therefore, static electricity is also generated when the protective film is peeled off from an optical member such as a polarizing plate. When a voltage is applied to the liquid crystal while static electricity remains, alignment of the liquid crystal molecules is lost or a defect occurs in the panel. In addition, the presence of static electricity can be a factor that attracts dust or deteriorates workability. For these reasons, antistatic treatment is performed on a surface protection film, and for example, by forming an antistatic layer or performing an antistatic coating as a surface layer (top coating layer, back layer) of a surface protection film, A prevention function is provided (refer to Patent Literatures 2 and 3).

In recent years, as a conductive polymer used to impart an antistatic function to the surface layer of a surface protection film, PEDOT (poly(3,4-ethylenedioxythiophene)/PSS (polystyrene sulfonate) (polythiophene type) However, when the antistatic layer is formed using the above-mentioned conductive polymer, PSS (corresponding to a dopant) is desorbed from PEDOT with the passage of time, and the surface resistivity and peeling electrification voltage A rise or the like may occur, and problems such as an increase (deterioration) in surface resistivity accompanying oxidative degradation or photodegradation may occur.

In addition, when a rise (deterioration) of the surface resistivity or the like occurs, when the surface protection film is peeled off from the adherend, static electricity is generated, causing a concern of occurrence of problems.

In addition, this surface protection film is peeled off and removed at a stage where it becomes unnecessary, but damage to the polarizing plate or liquid crystal cell is likely to occur in the peeling step accompanying the enlargement and thinning of the liquid crystal display panel, so lifting or the like occurs at the time of peeling. While having appropriate adhesive force so as not to occur, easy peelability, pick-up property, etc. are calculated|required so that re-peeling may be possible. In particular, in recent years, along with the thinning of displays, the optical members constituting the display have also been reduced in thickness, and in the case of an optical member having a thickness of 150 μm or less, or a thinner 100 μm or less, the optical member is bent during the conveying process, and thus conveyed. will not be able to In addition, problems such as the optical member being unable to be neatly bonded to other members have also arisen. In order to avoid such a problem, a method of suppressing warpage by thickening the surface protection film is performed, but since peeling becomes heavy by thickening, when peeling the surface protection film with a pickup tape at a stage where the surface protection film is unnecessary, it can be picked up. There is a problem that doesn't exist. Therefore, a pressure-sensitive adhesive sheet capable of suppressing warpage and enabling re-peeling, achieving easy peelability and pick-up properties is desired.

Japanese Unexamined Patent Publication No. 2003-334911 Japanese Unexamined Patent Publication No. 2000-26817 Japanese Unexamined Patent Publication No. 2008-255332

Accordingly, the present invention provides a pressure-sensitive adhesive sheet capable of improving antistatic properties and pick-up properties and an optical member protected by the pressure-sensitive adhesive sheet.

That is, the pressure-sensitive adhesive sheet of the present invention has a first resin layer, an adhesive layer, a second resin layer, and a pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive composition in this order, and the thickness of the first resin layer and the second resin layer The value of the ratio of the thickness of the adhesive layer to the sum of the thicknesses of is 0.50 or less, the storage modulus of the adhesive layer at 23 ° C is 1.0 × 10 ⁴ Pa or more and less than 5.0 × 10 ⁷ Pa, and the first resin layer A composition for a top coating layer having a top coating layer on a surface opposite to the surface having the pressure-sensitive adhesive layer, the top coating layer containing polyaniline sulfonic acid as a conductive polymer component, a polyester resin as a binder component, and an isocyanate-based compound as a crosslinking agent. It is characterized by being formed.

In the pressure-sensitive adhesive sheet of the present invention, it is preferable that the composition for the top coating layer further contains a fatty acid 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 PSA sheet of the present invention, the PSA composition preferably contains at least one selected from the group consisting of acrylic PSA, urethane PSA, and polyester PSA.

In the PSA sheet of the present invention, it is preferable that the PSA composition contains an antistatic component.

The optical member of the present invention is preferably protected by the pressure-sensitive adhesive sheet.

According to the adhesive sheet of the present invention, by having a resin layer film (first resin layer, adhesive layer, second resin layer in this order, also referred to as a laminated film) in which resin layers are laminated with an adhesive layer interposed therebetween, when peeling the adhesive sheet Stress relaxation is achieved in the portion of the adhesive layer against deformation, and it becomes possible to pick up with a peeling force (adhesive force) lower than that of the resin layer alone. In addition, by the above laminated configuration, the amount of warpage of the laminated film can be improved (reduction of the amount of warpage) compared to the amount of warpage of each resin layer film, and the problem of conveying defects due to bending or deformation in the conveying process is improved. This makes it possible to achieve an improvement in manufacturing efficiency. In addition, by having a top coating layer containing a specific raw material on one side of the resin layer film, a pressure-sensitive adhesive sheet excellent in antistatic properties and pick-up properties can be obtained, which is a preferable form.

1 is a schematic cross-sectional view of a protective film according to a preferred embodiment of the present invention.
2 is an explanatory view showing a method for measuring a peeling electrification voltage.
3 : is explanatory drawing which shows the measuring method of back adhesive force (A).
Fig. 4 is an explanatory view showing a peeling method of an adhesive sheet according to an embodiment.
5 is an explanatory view showing a method for measuring the amount of warpage.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail.

<Adhesive sheet (surface protection film)>

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 configuration including a first resin layer 6, an adhesive layer 7, and a second resin layer 8 (these first resin layers, adhesive layers, and second resin layers in order). , also referred to as "resin layer film") and the pressure-sensitive adhesive layer 20 in this order, and a top coating layer on the surface opposite to the surface of the first resin layer 6 having the pressure-sensitive adhesive layer 20 (14). The pressure-sensitive adhesive sheet 1 is obtained by laminating the first resin layer 6 and the second resin layer 8 with an adhesive layer 7 interposed therebetween, and further comprising a pressure-sensitive adhesive layer 20 and a top coating layer 14. It is a layered body. In addition, it is bonded to an adherend (eg, an optical member) by the pressure-sensitive adhesive layer 20 . In addition, although not shown, it is a preferred form that the separator is bonded to the surface of the pressure-sensitive adhesive layer 20 until it is bonded to the adherend.

<Resin layer>

The resin layer is preferably composed of a resin film. The thickness of the resin layer is preferably 1 to 200 μm, more preferably 12 to 75 μm. The magnitude 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), and the thickness of the first resin layer in that case is , preferably 1 to 50 μm, more preferably 4 to 38 μm, most preferably 10 to 25 μm. Further, the thickness of the second resin layer is preferably 10 to 200 μm, more preferably 25 to 130 μm, and most preferably 38 to 75 μm. If it is within the above range, both suppression of the amount of warpage of the pressure-sensitive adhesive sheet and pick-up properties can be achieved, resulting in a preferable form.

The tensile strength of at least one resin layer in the MD direction (flow direction) can be set to any suitable value. The tensile strength of the resin layer in the MD direction (flow direction) is preferably 90 to 350 MPa, more preferably 110 to 320 MPa, more preferably 130 to 300 MPa, and most preferably 180 to 250 MPa. If it is within the above range, it becomes possible to suppress the amount of warping of the pressure-sensitive adhesive sheet, and it becomes a preferable form.

In the technology disclosed herein, the resin material constituting the resin layer (support/substrate) can be used without particular limitation, but, for example, transparency, mechanical strength, thermal stability, moisture barrier property, isotropy, flexibility, and dimensional stability It is preferable to use those having excellent properties such as In particular, when the resin layer has flexibility, the pressure-sensitive adhesive composition can be applied with a roll coater or the like and can be wound up in a roll shape, which is useful.

Examples of the resin layer include polyester polymers such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate; cellulosic polymers such as diacetyl cellulose and triacetyl cellulose; polycarbonate-based polymers; acrylic polymers such as polymethyl methacrylate; A plastic film composed of a resin material containing, for example, as the main resin component (the main component in the resin component, typically 50% by mass or more) can be preferably used as the resin layer. Other examples of the resin material include styrenic polymers such as polystyrene and acrylonitrile-styrene copolymer; olefinic polymers such as polyethylene, polypropylene, polyolefins having a cyclic or norbornene structure, and ethylene-propylene copolymers; vinyl chloride-based polymers; amide polymers such as nylon 6, nylon 6,6, and aromatic polyamide; What makes the etc. a resin material is mentioned. As another example of the resin material, imide-based polymers, sulfone-based polymers, polyether sulfone-based polymers, polyether ether ketone-based polymers, polyphenylene sulfide-based polymers, vinyl alcohol-based polymers, vinylidene chloride-based polymers, vinylbuty A ral type polymer, an arylate type polymer, a polyoxymethylene type polymer, an epoxy type polymer, etc. are mentioned. It may be a resin layer containing a blend of two or more of the polymers described above.

As the resin layer, a plastic film made of a transparent thermoplastic resin material can be preferably used. Among the plastic films, in the pressure-sensitive adhesive sheet of the present invention, at least one of the resin layers is a polyester film. It is a more preferable form. Here, the polyester film refers to a polymer material (polyester resin) having a main skeleton based on an ester bond such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), or polybutylene terephthalate as a main resin component. say to do While such a polyester film has desirable properties as a resin layer of an adhesive sheet (surface protection film), such as excellent optical characteristics and dimensional stability, it has a property that is easily charged in its state. Moreover, as a resin layer which satisfies the said tensile strength, the following resin is mentioned. polyester polymers such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate; cellulosic polymers such as diacetyl cellulose and triacetyl cellulose; polycarbonate-based polymers; acrylic polymers such as polymethyl methacrylate; polystyrene-based polymers; polyolefins having a cyclic to norbornene structure; amide polymers such as nylon 6, nylon 6,6, and aromatic polyamide; A plastic film composed of a resin material containing, for example, as the main resin component (the main component in the resin component, typically 50% by mass or more) can be preferably used as the resin layer. It may be a resin layer containing a blend of two or more of the polymers described above.

Various additives such as antioxidants, ultraviolet absorbers, plasticizers, and colorants (pigments, dyes, etc.) may be blended with the resin material constituting the resin layer, if necessary. In addition, the surface of the resin layer may be subjected to a known or customary surface treatment such as corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, coating of a primer, for example. Such surface treatment may be, for example, a treatment for enhancing adhesion between the resin layer and the pressure-sensitive adhesive layer or top coating layer (anchoring property of the pressure-sensitive adhesive layer, etc.). A surface treatment in which a polar group such as a hydroxyl group is introduced into the surface of the resin layer can be preferably employed.

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

<Adhesive layer>

The "adhesive layer" in the present invention means that the surfaces of adjacent resin layers are bonded together to integrate them with sufficient adhesive strength and bonding time for practical use. Examples of materials forming the adhesive layer include adhesives, adhesives, and anchor coating agents. The adhesive layer may have a multilayer structure in which an anchor coating layer is formed on the surface of a resin layer and an adhesive layer is formed thereon. In addition, the "adhesive layer" in this invention means exfoliation possible (repeelability).

The value of the ratio of the thickness of the adhesive 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. below By setting in such a range, warpage of the adherend (for example, optical member) can be very well suppressed. On the other hand, the value of the thickness ratio is preferably 0.03 or more. By setting in such a range, the flexibility of the PSA sheet obtained is more excellent, and very excellent peelability can be achieved.

The thickness of the adhesive 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, more preferably 5 μm or more. If this difference is too small, there is a possibility that the pick-up properties of the adhesive sheet may become insufficient depending on the thickness of the resin layer. The thickness of the adhesive layer is preferably 1 to 50 μm, more preferably 2 to 25 μm, still more preferably 5 to 20 μm. If the thickness of the adhesive layer is too thick, problems (for example, lack of glue) may occur in forming the adhesive layer.

According to the PSA sheet of the present invention, stress relief is achieved by forming the adhesive layer, the peeling force of the resulting PSA sheet can be reduced, the pick-up property can be improved, and pickup can be performed with a peel force lower than that of the resin layer alone. . In addition, by having a resin layer film in which resin layers are laminated through the adhesive layer (in order of the first resin layer, the adhesive layer, and the second resin layer), the warpage amount of the laminated film is improved compared to the warpage amount of each resin layer film ( reduction of the amount of warpage) becomes possible, it becomes possible to improve the problem of conveying defects due to bending or deformation in the conveying process, and it is possible to achieve improvement in manufacturing efficiency. In addition, the adhesive layer has a storage modulus at 23°C of 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 1.0×10 7 Pa or more. 10 ⁵ Pa or more and less than 1.0×10 ⁶ Pa. The storage modulus of the adhesive layer is measured using a dynamic viscoelasticity measuring device under conditions of a frequency of 1 Hz.

The adhesive 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. As the crosslinking agent, any compound that reacts with the (meth)acrylic polymer may be used without particular limitation, but isocyanate compounds, epoxy compounds, melamine resins, aziridine derivatives, and metal chelate compounds are preferably used.

The (meth)acrylic polymer refers to a polymer or copolymer synthesized from acrylate-based monomers and/or methacrylate-based monomers (herein referred to as (meth)acrylate). When the (meth)acrylic polymer is a copolymer, the molecular arrangement is not particularly limited, and may be a random copolymer, a block copolymer, or a graft copolymer. A preferred molecular arrangement state is a random copolymer. In addition, the polymerization method is not particularly limited, and polymerization can be performed by a known method such as solution polymerization, emulsion polymerization, bulk polymerization, or suspension polymerization.

The said (meth)acrylic polymer is obtained by homopolymerizing or copolymerizing alkyl (meth)acrylate, for example. The alkyl group of the alkyl (meth)acrylate may be linear, branched or cyclic. The number of carbon atoms in the alkyl group of the alkyl (meth)acrylate 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, iso-butyl (meth) acrylate, t-butyl(meth)acrylate, n-pentyl(meth)acrylate, iso-pentyl(meth)acrylate, n-hexyl(meth)acrylate, iso-hexyl(meth)acrylate, n-heptyl(meth)acrylate ) acrylate, iso-heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, iso-octyl (meth) acrylate, n-nonyl (meth) acrylate, iso-nonyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, and cyclohexyl (meth)acrylate. These are used individually or in combination of 2 or more types.

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

Specific examples of the hydroxyl group-containing (meth)acrylate include 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxyethyl (meth)acrylate. Roxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 5-hydroxypentyl (meth)acrylate, 3-hydroxy-3-methylbutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 7-hydroxyheptyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, (4-hydroxymethylcyclohexyl)methyl (meth)acrylate, etc. are mentioned. These are used individually or in combination of 2 or more types.

The number of carbon atoms of the hydroxyalkyl group of the hydroxyl group-containing (meth)acrylate is preferably smaller than the number of carbon atoms of the alkyl group of the alkyl (meth)acrylate. The number of carbon atoms in the hydroxyalkyl group of the hydroxyl group-containing (meth)acrylate is preferably 1 to 8, more preferably 2 to 4, still more preferably 2. In this way, by adjusting the carbon number of the alkyl group, the reactivity with an isocyanate-based compound described later can be improved, and an adhesive having even more excellent adhesive properties can be obtained.

The copolymerization amount of the hydroxyl group-containing (meth)acrylate is preferably 0.05 to 20% by mol, more preferably 0.10 to 8% by mol, even more preferably 0.12 to 3% by mol, still more preferably 0.14% by mol. to 1.5 mol%, most preferably 0.14 to 0.25 mol%.

The (meth)acrylic polymer can also be obtained by copolymerizing other components in addition to the alkyl (meth)acrylate and the hydroxyl group-containing (meth)acrylate. Although it does not specifically limit as another component, (meth)acrylic acid, benzyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, phenoxyethyl (meth)acrylate, (meth) ) Acrylamide, vinyl acetate, (meth)acrylonitrile, etc. are preferably used. The copolymerization amount of the 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 the alkyl (meth)acrylate.

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

As said isocyanate compound, 2,4- (or 2,6-) tolylene diisocyanate, xylylene isocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, hexamethylene diisocyanate, norbornene diisocyanate , isocyanate monomers such as chlorophenylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, trimethylolpropanexylene diisocyanate, and hydrogenated diphenylmethane diisocyanate; adduct isocyanate compounds obtained by adding these isocyanate monomers to polyhydric alcohols such as trimethylolpropane; isocyanurate compounds; biuret-type compounds; Further, urethane prepolymer type isocyanate obtained by addition reaction of any suitable polyether polyol, polyester polyol, acrylic polyol, polybutadiene polyol, polyisoprene polyol, etc. is exemplified, and these are used alone or in combination of two or more. .

As the isocyanate-based compound, a commercial product may be used as it is. Examples of commercially available isocyanate-based compounds include the Takenate series manufactured by Mitsui Takeda Chemicals Co., Ltd. (trade name "D-110N, 500, 600, 700", etc.) and the Coronate series manufactured by Nippon Polyurethane Kogyo Co., Ltd. (For example, a brand name "L, MR, EH, HL", etc.) is mentioned.

As said epoxy compound, for example, N,N,N',N'-tetraglycidyl-m-xylenediamine (brand name TETRAD-X, manufactured by Mitsubishi Gas Chemical Co., Ltd.) or 1,3-bis(N,N -Diglycidyl aminomethyl) cyclohexane (trade name TETRAD-C, manufactured by Mitsubishi Gas Chemical Co., Ltd.); and the like.

As said melamine-type resin, hexamethylol melamine etc. are mentioned. Examples of the aziridine derivatives include commercially available products under trade names HDU, TAZM, and TAZO (above, manufactured by Sogo Yakko Co., Ltd.).

As said metal chelate compound, aluminum, iron, tin, titanium, nickel etc. are mentioned as a metal component, Acetylene, methyl acetoacetate, ethyl lactate, etc. are mentioned as a chelate component.

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, based on 100 parts by mass of the (meth)acrylic polymer. It is more preferably contained in an amount of 0.3 to 1.5 parts by mass, and most preferably contained in an amount of 0.4 to 0.9 parts by mass. By setting it as such content, adhesiveness can become favorable also under severe (high temperature, high humidity) environment. In addition, these crosslinking agents may be used independently, and may mix and use 2 or more types.

The acrylic adhesive (adhesive composition) preferably further contains a silane coupling agent or a radiation curable component. As the silane coupling agent, one having any suitable functional group can be selected, for example. Examples of the functional group include a vinyl group, an epoxy group, a methacryloxy group, an amino group, a mercapto group, an acryloxy group, an acetoacetyl group, an isocyanate group, a styryl group, and a polysulfide group. Specific examples of the silane coupling agent include vinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, and γ-methacryloxy. Propyltrimethoxysilane, γ-acryloxypropyltrimethoxysilane, N-β(aminoethyl)γ-aminopropyltrimethoxysilane, γ-aminopropylmethoxysilane, γ-mercaptopropylmethyldimethoxysilane, Bis (triethoxysilylpropyl) tetrasulfide, γ-isocyanate propyl trimethoxysilane, etc. are mentioned. Among these, a silane coupling agent having an epoxy group is preferred, and γ-glycidoxypropyltrimethoxysilane is more preferred.

As the silane coupling agent, a commercially available product may be used as it is. As commercially available products, for example, Shin-Etsu Silicone Co., Ltd. KA series (trade names "KA-1003", etc.), KBM series (trade names "KBM-303, KBM-403, KBM-503", etc.) and KBE series ( Product names "KBE-402, KBE-502, KBE-903", etc.), Toray Industries, Ltd. SH series (brand names "SH6020, SH6040, SH6062", etc.) and SZ series (brand names "SZ6030, SZ6032, SZ6300", etc.) can be heard

The content of the silane coupling agent is preferably 0.001 to 2.0 parts by mass, more preferably 0.005 to 2.0 parts by mass, still more preferably 0.01 to 1.0 parts by mass, based on 100 parts by mass of the (meth)acrylic polymer. , particularly preferably 0.02 to 0.5 parts by mass. By setting it as such a content, peeling and generation|occurrence|production of air bubbles can be suppressed even under severe (high temperature, high humidity) environment.

As the radiation-curable component, a monomer and/or oligomer component subjected to radical polymerization or cationic polymerization by radiation is used. Examples of the monomer component radically polymerized by radiation include monomers having an unsaturated double bond such as a (meth)acryloyl group and a vinyl group. In particular, a monomer having a (meth)acryloyl group is preferably used because of its excellent reactivity. do. Specific examples of the monomer component having a (meth)acryloyl group include allyl (meth)acrylate, caprolactone (meth)acrylate, cyclohexyl (meth)acrylate, and N,N-diethylaminoethyl (meth)acrylate. , 2-ethylhexyl (meth) acrylate, heptadecafluorodecyl (meth) acrylate, glycidyl (meth) acrylate, caprolactone-modified 2-hydroxylethyl (meth) acrylate, isobornyl (meth) ) Acrylate, morpholine (meth) acrylate, phenoxyethyl (meth) acrylate, tripropylene glycol di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, hydroxypivalic acid neo Pentylglycoldi(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolpropaneethoxytri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate , dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth)acrylate, and the like.

As an oligomer component radically polymerized by radiation, a polyester obtained by adding two or more unsaturated double bonds such as a (meth)acryloyl group and a vinyl group as functional groups similar to those of the monomer component to the backbone of polyester, epoxy, urethane, etc. ( Meth) acrylate, epoxy (meth) acrylate, urethane (meth) acrylate and the like are used.

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 polyhydric carboxylic acid, and specific examples include Aronix M-6000, 7000, and 8000 manufactured by Toagosei Co., Ltd. , polyester acrylates of the 9000 series.

Epoxy (meth)acrylate is obtained by reacting (meth)acrylic acid with an epoxy resin, and specific examples include Lipoxy SP and VR series manufactured by Showa Kobunshi Co., Ltd. and epoxy ester series manufactured by Kyoeisha Chemical Co., Ltd. Epoxy acrylate is mentioned.

Urethane (meth)acrylate is obtained by reacting polyol, isocyanate, and hydroxy (meth)acrylate, and specific examples include Art Resin UN series manufactured by Negami Kogyo Co., Ltd. and NK Oligo U manufactured by Shin Nakamura Chemical Industry Co., Ltd. series, Nippon Kosei Chemical Industry Co., Ltd. product Shiko UV series urethane acrylate.

As the monomer and/or oligomer component subjected to cationic polymerization, a compound having a cationically polymerizable functional group, for example, an epoxy group, a hydroxyl group, a vinyl ether group, an episulfide, or an ethylenimine group, is used. used Examples of the compound having an epoxy group include glycidyl ether type epoxy resins produced by a reaction between a polyhydric phenolic compound or a polyhydric alcohol and epichlorohydrin. Specifically, diglycidyl ether of bisphenol A or its alkylene oxide adduct, diglycidyl ether of bisphenol F or its alkylene oxide adduct, and diglycidyl of hydrogenated bisphenol A or its alkylene oxide adduct. Dyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, butanediol diglycidyl ether, hexanediol diglycidyl ether, cyclohexane dimethanol diglycidyl diglycidyl ether, polypropylene glycol diglycidyl ether, trimethylolpropane polyglycidyl ether, pentaerythritol polyglycidyl ether, sorbitol polyglycidyl ether, and resorcin diglycidyl ether.

These (meth)acrylic polymers and radiation-curable components are used in appropriate combinations, but poor compatibility (miscibility) makes it difficult to balance the adhesiveness after radiation curing with the storage modulus, or the light transmittance after curing deteriorates. It is necessary to properly select a combination with good compatibility in In particular, for applications requiring light transmittance, the total light transmittance after curing is adjusted to be 85% or more (preferably 90% or more) and haze value 10% or less (preferably 5% or less). In addition, the blending amount of the radiation curable component is appropriately adjusted according to the storage modulus and adhesiveness after radiation curing, but is generally used in a ratio of 10 to 200 parts by mass, preferably 30 to 150 parts by mass, based on 100 parts by mass of the adhesive polymer. .

The usage amount of the polyfunctional monomer is appropriately selected depending on the balance with the (meth)acrylic polymer and further depending on the use as an adhesive sheet. In order to obtain sufficient heat resistance due to the cohesive force of the acrylic pressure-sensitive adhesive, it is generally preferable to blend 0.1 to 30 parts by mass with respect to 100 parts by mass of the (meth)acrylic polymer. In view of flexibility and adhesiveness, it is more preferable to blend 10 parts by mass or less with respect to 100 parts by mass of the (meth)acrylic polymer.

As radiation, for example, ultraviolet rays, laser rays, and α rays. Although β-rays, γ-rays, x-rays, electron beams and the like can be cited, ultraviolet rays are suitably used from the viewpoints of good controllability and handling, and cost. More preferably, ultraviolet rays with a wavelength of 200 to 400 nm are used. Ultraviolet rays can be irradiated using an appropriate light source such as a high-pressure mercury lamp, a microwave excitation type lamp, or a chemical lamp. In addition, when using ultraviolet rays as radiation, a photopolymerization initiator is added to the acrylic adhesive.

The photopolymerization initiator may be a substance that generates radicals or cations by irradiating ultraviolet rays of an appropriate wavelength that can trigger the polymerization reaction depending on the type of the radiation-reactive component, and examples of the photoradical polymerization initiator include benzoin, Benzoins such as benzoin methyl ether, benzoin ethyl ether, o-benzoyl methyl benzoate, benzoin ethyl ether, benzoin isopropyl ether, α-methylbenzoin, benzyldimethyl ketal, trichloroacetophenone, 2,2- acetophenones such as diethoxyacetophenone and 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methylpropiophenone, 2-hydroxy-4'-isopropyl-2-methylpropiophenone, etc. Benzophenones such as propiophenones, benzophenone, methylbenzophenone, p-chlorobenzophenone and p-dimethylaminobenzophenone, 2-chlorothioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone thioxanthones, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, (2,4,6-trimethylbenzoyl)-( Acyl phosphine oxides, such as ethoxy)-phenylphosphine oxide, benzyl, dibenzo suberone, alpha-acyl oxime ester, etc. are mentioned. Examples of the photocationic polymerization initiator include onium salts such as aromatic diazonium salts, aromatic iodonium salts, and aromatic sulfonium salts, organometallic complexes such as iron-alene complexes, titanocene complexes, and arylsilanol-aluminum complexes; Nitrobenzyl ester, sulfonic acid derivative, phosphoric acid ester, sulfonic acid derivative, phosphoric acid ester, phenolsulfonic acid ester, diazonaphthoquinone, N-hydroxyimidosulfonate, etc. are mentioned.

About the said photoinitiator, it is also possible to use 2 or more types together. The photopolymerization initiator is preferably incorporated in an amount of usually 0.1 to 10 parts by mass, preferably 0.2 to 7 parts by mass, based on 100 parts by mass of the (meth)acrylic polymer.

Moreover, it is also possible to use photoinitiation auxiliary agents, such as amines, together. Examples of the photopolymerization initiation auxiliary include 2-dimethylaminoethyl benzoate, dimethylaminoacetophenone, p-dimethylaminobenzoic acid ethyl ester, and p-dimethylaminobenzoic acid isoamyl ester. About the said photopolymerization start adjuvant, it is also possible to use 2 or more types together. The polymerization initiation aid is preferably blended in the range of 0.05 to 10 parts by mass, furthermore 0.1 to 7 parts by mass, based on 100 parts by mass of the (meth)acrylic polymer.

<Method of laminating the first resin layer and the second resin layer>

As a method of laminating the first resin layer and the second resin layer, any suitable method may be employed. As a preferred embodiment, a method of forming an adhesive layer on one resin layer and laminating the other resin layer on the adhesive layer is employed. In addition, as a method of forming the adhesive layer, any suitable method may be employed. As a specific example, the adhesive layer can be formed by applying the adhesive (adhesive composition solution) to the resin layer and heating it. At the time of application, it is preferable that the polymer concentration of the acrylic adhesive is appropriately adjusted with a solvent (eg, ethyl acetate or toluene). The heating temperature is preferably 20°C to 200°C, more preferably 50°C to 170°C.

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

<Adhesive layer>

The pressure-sensitive adhesive sheet of the present invention has the pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer is formed of a pressure-sensitive adhesive composition, and as the pressure-sensitive adhesive composition, any material having adhesiveness can be used without particular limitation. For example, acrylic adhesives, urethane-based adhesives, polyester-based adhesives, synthetic rubber-based adhesives, natural rubber-based adhesives, silicone-based adhesives, etc. may be used, and among them, acrylic adhesives, urethane-based adhesives, and polyester-based adhesives are more preferred. It is at least one kind selected from the group consisting of, and it is especially preferable to use an acrylic adhesive using a (meth)acrylic polymer.

When the pressure-sensitive adhesive layer uses an acrylic pressure-sensitive adhesive, the (meth)acrylic polymer constituting the acrylic pressure-sensitive adhesive may use a (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms as a raw material monomer constituting this. As said (meth)acrylic-type monomer, 1 type, or 2 or more types can be used as a main component. By using the (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms, it is easy to control the adhesive force to the adherend (substrate) to a low level, and a pressure-sensitive adhesive sheet having excellent easy-peelability and re-peelability is obtained. lose In addition, the (meth)acrylic polymer in the present invention refers to an acrylic polymer and/or a methacrylic polymer, and (meth)acrylate refers to an acrylate and/or methacrylate.

Specific examples of the (meth)acrylic monomer having an alkyl group of 1 to 14 carbon atoms include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, and s-butyl (meth)acrylate. Acrylate, t-butyl(meth)acrylate, isobutyl(meth)acrylate, hexyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, n-octyl(meth)acrylate, isooctyl(meth)acrylate )Acrylate, n-nonyl(meth)acrylate, isononyl(meth)acrylate, n-decyl(meth)acrylate, isodecyl(meth)acrylate, n-dodecyl(meth)acrylate, n- Tridecyl (meth)acrylate, n-tetradecyl (meth)acrylate, etc. are mentioned.

Among them, when the pressure-sensitive adhesive sheet of the present invention is used as a surface protection 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-dodecyl (meth) acrylate, n-tridecyl ( Suitable examples include (meth)acrylic monomers having an alkyl group having 6 to 14 carbon atoms, such as meth)acrylate and n-tetradecyl(meth)acrylate. In particular, by using a (meth)acrylic monomer having an alkyl group of 6 to 14 carbon atoms, it is easy to control the adhesive force to the adherend to a low level, resulting in excellent re-peelability.

In particular, it is preferable to contain 50% by mass or more of a (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms with respect to 100% by mass of the total amount of monomer components constituting the (meth)acrylic polymer, more preferably 60% by mass. % or more, more preferably 70% by mass or more, particularly preferably 80 to 93% by mass. When it is less than 50% by mass, the appropriate wettability of the pressure-sensitive adhesive composition and the cohesive force of the pressure-sensitive adhesive layer are deteriorated, which is not preferable.

In the pressure-sensitive adhesive composition of the present invention, the (meth)acrylic polymer preferably contains a (meth)acrylic monomer having a hydroxyl group as a raw material monomer. As a (meth)acrylic monomer which has the said hydroxyl group, 1 type, or 2 or more types can be used as a main component.

By using the (meth)acrylic monomer having the above hydroxyl group, it becomes easy to control the crosslinking of the pressure-sensitive adhesive composition, and furthermore, it becomes easy to control the balance between improvement of wettability due to flow and reduction of adhesive force in peeling. . In addition, unlike a carboxyl group or a sulfonate group that can generally act as a crosslinking moiety, a hydroxyl group has an appropriate interaction with an ionic compound that is an antistatic component (antistatic agent), so it is suitable also in terms of antistatic properties. can be used

As a (meth)acrylic monomer having the said hydroxyl group, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6 -Hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, (4-hydroxymethyl Cyclohexyl) methyl (meth)acrylate, N-methylol (meth)acrylamide, etc. are mentioned. In particular, the use of a (meth)acrylic monomer having a hydroxyl group having 4 or more carbon atoms in the alkyl group facilitates easy peeling at the time of high-speed peeling, which is preferable.

It is preferable to contain 15 parts by mass or less of the (meth)acrylic monomer having the hydroxyl group with respect to 100 parts by mass of the (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms, more preferably 1 to 13 Part by mass, more preferably 2 to 11 parts by mass, most preferably 3.5 to 10 parts by mass. When it exists in the said range, since it becomes easy to control the balance of the wettability of an adhesive composition, and the cohesion force of the adhesive layer obtained, it is preferable. Moreover, it becomes easy to obtain the adhesive composition with good creep characteristics by mix|blending especially 5 mass parts or more.

In addition, as other polymerizable monomer components, the glass transition temperature and peelability of the (meth)acrylic polymer are adjusted so that the Tg is 0 ° C or less (usually -100 ° C or more) for the reason that it is easy to balance the adhesive performance. A polymerizable monomer or the like for the purpose can be used within a range not impairing the effect of the present invention.

As other polymerizable monomers other than the (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms and the (meth)acrylic monomer having a hydroxyl group used in the (meth)acrylic polymer, (meth)acrylic monomer having a carboxyl group ) An acrylic monomer may be used.

Examples of the (meth)acrylic monomer having the carboxyl group include (meth)acrylic acid, carboxylethyl (meth)acrylate, carboxylpentyl (meth)acrylate, and 2-(meth)acryloyloxyethylhexahydrophthalic acid. , 2-(meth)acryloyloxypropylhexahydrophthalic acid, 2-(meth)acryloyloxyethyl phthalic acid, 2-(meth)acryloyloxyethyl succinic acid, 2-(meth)acryloyloxyethyl maleate acid, carboxy polycaprolactone mono(meth)acrylate, 2-(meth)acryloyloxyethyl tetrahydrophthalic acid, and the like.

The (meth)acrylic monomer having a carboxyl group is preferably 5 parts by mass or less, more preferably 1 part by mass or less, and 0.2 parts by mass based on 100 parts by mass of the (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms. Less than part is more preferable, and it is 0.01 part by mass or more and less than 0.1 part by mass most preferably. In particular, there are cases where a pressure-sensitive adhesive composition having excellent creep characteristics is obtained by using a (meth)acrylic monomer having a carboxyl group in combination with a (meth)acrylic monomer having a hydroxyl group. In addition, when it exceeds 5 parts by mass, there are many acid functional groups such as carboxyl groups with large interactions, and when blending an ionic compound as an antistatic component, the acid functional groups such as carboxyl groups interact with the ionic compound, thereby It is undesirable because it may interfere with ion conduction, reduce the conduction efficiency, and there is a possibility that sufficient antistatic properties may not be obtained. In particular, in the case of achieving both creep property and easy peelability, 5 parts by mass or more of the (meth)acrylic monomer having the hydroxyl group and 0.01 part by mass or more of the (meth)acrylic monomer having the carboxyl group By containing less than 0.1 part by mass, compatibility of properties is achieved, which is preferable.

In addition, polymerization other than the (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms used in the (meth)acrylic polymer, the (meth)acrylic monomer having a hydroxyl group, and the (meth)acrylic monomer having a carboxyl group As a sex monomer, it can be used without any particular limitation as long as it is within a range not impairing the properties of the present invention. For example, components for improving cohesion and heat resistance such as cyano group-containing monomers, vinyl ester monomers, aromatic vinyl monomers, amide group-containing monomers, imide group-containing monomers, amino group-containing monomers, epoxy group-containing monomers, N-acryloylmorpholine , A component having a functional group that acts as an adhesive force improvement or crosslinking origin, such as a vinyl ether monomer, can be used as appropriate. 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 the vinyl ester monomer include vinyl acetate, vinyl propionate, and vinyl laurate.

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

Examples of the amide group-containing monomer include acrylamide, methacrylamide, diethylacrylamide, N-vinylpyrrolidone, N,N-dimethylacrylamide, N,N-dimethylmethacrylamide, and N,N-di Ethyl acrylamide, N,N-diethyl methacrylamide, N,N'-methylenebisacrylamide, N,N-dimethylaminopropyl acrylamide, N,N-dimethylaminopropyl methacrylamide, diacetone acrylamide, etc. can be heard

As an imide group containing monomer, cyclohexyl maleimide, isopropyl maleimide, N-cyclohexyl maleimide, itaconimide etc. are mentioned, for example.

Examples of the amino group-containing monomer include aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and N,N-dimethylaminopropyl (meth)acrylate.

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

As a vinyl ether monomer, methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether etc. are mentioned, for example.

In the present invention, the other polymerizable monomers other than 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 are It is preferably 0 to 40 parts by mass, and more preferably 0 to 30 parts by mass with respect to 100 parts by mass of the (meth)acrylic monomer having a 14-membered alkyl group. When using an ionic compound as an antistatic agent, by using the said other polymerizable monomer within the said range, favorable interaction with the said ionic compound and favorable releasability can be adjusted suitably.

The (meth)acrylic polymer may further contain an alkylene oxide group-containing reactive monomer as a monomer component. The average added mole number of oxyalkylene units of the alkylene oxide group-containing reactive monomer is preferably 1 to 40, more preferably 3 to 40, from the viewpoint of compatibility with the ionic compound as an antistatic component, It is more preferable that it is 4-35, and it is especially preferable that it is 5-30. When the average number of moles added is 1 or more, the effect of reducing contamination of the adherend (object to be protected) tends to be obtained efficiently. In addition, when the average added mole number is greater than 40, the interaction with the ionic compound is large, the viscosity of the pressure-sensitive adhesive composition increases, and the coating tends to be difficult, which is not preferable. Further, the terminal of the oxyalkylene chain may remain as a hydroxyl group or may be substituted with another functional group or the like.

The alkylene oxide group-containing reactive monomer may be used alone or in combination of two or more, but the content as a whole is preferably 35 mass% or less of the total amount of monomer components of the (meth)acrylic polymer, It is more preferably 20% by mass or less, more preferably 15% by mass or less, and particularly preferably 5% by mass or less. When the content of the alkylene oxide group-containing reactive monomer exceeds 35% by mass, when blending an ionic compound as an antistatic component, the interaction with the ionic compound becomes large, ionic conduction is hindered, and antistatic properties are improved. deterioration, which is undesirable.

Examples of the oxyalkylene unit of the alkylene oxide group-containing reactive monomer include those having an alkylene group having 1 to 6 carbon atoms, examples of which include an oxymethylene group, an oxyethylene group, an oxypropylene group, and an oxybutylene group. can The hydrocarbon group of the oxyalkylene chain may be straight-chain or branched.

Moreover, it is more preferable that the reactive monomer containing an alkylene oxide group is a reactive monomer having an ethylene oxide group. By using a (meth)acrylic polymer having a reactive monomer having an ethylene oxide group as the base polymer, the compatibility between the base polymer and the ionic compound is improved, bleed to the adherend is appropriately suppressed, and low-staining pressure-sensitive adhesive composition is obtained.

Examples of the alkylene oxide group-containing reactive monomer include (meth)acrylic acid alkylene oxide adducts and reactive surfactants having reactive substituents such as acryloyl, methacryloyl, and allyl groups in the molecule. have.

Specific examples of the (meth)acrylic acid alkylene oxide adduct include polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, polyethylene glycol-polypropylene glycol (meth)acrylate, and polyethylene glycol-polybutyl. Len glycol (meth) acrylate, polypropylene glycol-polybutylene glycol (meth) acrylate, methoxy polyethylene glycol (meth) acrylate, ethoxy polyethylene glycol (meth) acrylate, butoxy polyethylene glycol (meth) acrylate Latex, octoxy polyethylene glycol (meth) acrylate, lauroxy polyethylene glycol (meth) acrylate, stearoxy polyethylene glycol (meth) acrylate, phenoxy polyethylene glycol (meth) acrylate, methoxy polypropylene glycol (meth) Acrylate, octoxy polyethylene glycol-polypropylene glycol (meth)acrylate, etc. are mentioned.

Moreover, as a specific example of the said reactive surfactant, anionic reactive surfactant, nonionic reactive surfactant, cationic reactive surfactant etc. which have a (meth)acryloyl group or an allyl group are mentioned, for example.

The (meth)acrylic polymer preferably has a weight average molecular weight (Mw) of 100,000 to 5,000,000, more preferably 200,000 to 2,000,000, still more preferably 300,000 to 1,000,000. When the weight average molecular weight is smaller than 100,000, the cohesive force of the pressure-sensitive adhesive layer decreases, and thus the pressure-sensitive adhesive tends to occur. On the other hand, when the weight average molecular weight exceeds 5,000,000, the fluidity of the polymer is lowered, and the wetting to the adherend (eg, polarizing plate) becomes insufficient, causing swelling between the adherend and the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet. tends to cause In addition, a weight average molecular weight means what was obtained by measuring by gel permeation chromatography (GPC).

Further, 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, and for example, wetting to the polarizing plate becomes insufficient, which tends to cause swelling between the polarizing plate and the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet. In particular, by setting the glass transition temperature to -61°C or lower, it is easy to obtain an adhesive layer having excellent wettability to a polarizing plate and easy peelability. In addition, the glass transition temperature of the (meth)acrylic polymer can be adjusted within the above range by appropriately changing the monomer component and composition ratio to be used.

The polymerization method of the (meth)acrylic polymer is not particularly limited, and polymerization may be performed by a known method such as solution polymerization, emulsion polymerization, bulk polymerization, or suspension polymerization. From the viewpoint of properties such as low contamination of the protective body), solution polymerization is a more preferable form. Moreover, any, such as a random copolymer, a block copolymer, an alternating copolymer, and a graft copolymer, may be sufficient as the polymer obtained. In addition, polymerization conditions, polymerization solvents, polymerization initiators and the like can be appropriately used based on known techniques.

When the pressure-sensitive adhesive layer uses a urethane-based pressure-sensitive adhesive, any suitable urethane-based pressure-sensitive adhesive can be employed as the urethane-based pressure-sensitive adhesive. As such a urethane type adhesive, Preferably, the thing containing the urethane resin obtained by making a polyol and a polyisocyanate compound react is mentioned. As polyol, polyether polyol, polyester polyol, polycarbonate polyol, polycaprolactone polyol etc. are mentioned, for example. As a polyisocyanate compound, diphenylmethane diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate etc. are mentioned, for example.

In the case where the pressure-sensitive adhesive layer uses a polyester-based pressure-sensitive adhesive, any suitable polyester-based pressure-sensitive adhesive can be employed as the polyester-based pressure-sensitive adhesive. Examples of such a polyester-based pressure-sensitive adhesive include polyester obtained by polycondensation of a bifunctional or higher functional carboxylic acid component and a diol component. As the carboxylic acid component, dimer acid derived from sebacic acid, oleic acid, erucic acid, etc., adipic acid, azelaic acid, 1,4-cyclohexanedicarboxylic acid, 4-methyl-1,2-cyclohexane Aliphatic or alicyclic dicarboxylic acids such as dicarboxylic acid, dodecenyl succinic anhydride, fumaric acid, succinic acid, dodecanedioic acid, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, maleic acid, maleic anhydride, itaconic acid, citraconic acid, etc. acids, etc., terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 2,2'-dicarboxylic acid Phenyl dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, etc. are mentioned. As a diol component, an aliphatic diol, polyether glycol, etc. are mentioned.

<Antistatic component in the pressure-sensitive adhesive layer>

In the PSA sheet of the present invention, the PSA composition constituting the PSA layer preferably contains an antistatic component, and more preferably contains an ionic compound as the antistatic component. Examples of the ionic compound include alkali metal salts and/or ionic liquids having a melting point of 100°C or less. By containing these ionic compounds, excellent antistatic properties can be imparted. In addition, as described above, the pressure-sensitive adhesive layer (using the antistatic component) formed by crosslinking the pressure-sensitive adhesive composition containing the antistatic component prevents static electricity to an adherend (for example, a polarizing plate) that is not antistatic when peeled off. and becomes a pressure-sensitive adhesive sheet in which contamination of adherends is reduced. For this reason, it is very useful as an antistatic adhesive sheet in the technical field related to optical/electronic parts where electrification and contamination are particularly serious problems.

Further, the content of the antistatic component relative to 100 parts by mass of the (meth)acrylic polymer 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, and most preferably 0.005 to 0.8 parts by mass. Preferably it is 0.01-0.5 mass part. When it is within the above range, it is easy to achieve both antistatic properties and low staining properties, so it is preferable.

<Crosslinking agent>

In the PSA sheet of the present invention, it is preferable that the PSA composition contains a crosslinking agent. Moreover, in this invention, it can be set as an adhesive layer using the said adhesive composition. For example, when the pressure-sensitive adhesive contains the (meth)acrylic polymer, it has better heat resistance by crosslinking by appropriately adjusting the structural unit of the (meth)acrylic polymer, its composition ratio, and the selection and addition ratio of the crosslinking agent. A pressure-sensitive adhesive sheet (pressure-sensitive adhesive layer) can be obtained.

As the crosslinking agent used in the present invention, an isocyanate compound, an epoxy compound, a melamine resin, an aziridine derivative, a metal chelate compound, or the like may be used, and use of an isocyanate compound is particularly preferable. In addition, these compounds may be used independently, and may mix and use 2 or more types.

Examples of the isocyanate compound (isocyanate-based crosslinking agent) include aliphatic polyisocyanates such as trimethylene diisocyanate, butylene diisocyanate, hexamethylene diisocyanate (HDI), and dimer acid diisocyanate, cyclopentylene diisocyanate, and cyclohexylene diisocyanate , alicyclic isocyanates such as isophorone diisocyanate (IPDI), aromatic isocyanates such as 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene isocyanate (XDI), and the above isocyanate compounds modified polyisocyanates modified by an allophanate bond, a biuret bond, an isocyanurate bond, a uretdione bond, a urea bond, a carbodiimide bond, a uretonimine bond, an oxadiazinetrione bond, and the like. . For example, commercially available products under the trade names: Takenate 300S, Takenate 500, Takenate D165N, Takenate D178N (above, manufactured by Takeda Yakuhin Kogyo Co., Ltd.), Smidur T80, Smidur L, Desmodur N3400 (above, Sumi (manufactured by Bayer Urethane Co., Ltd.), Milionate MR, Milionate MT, Coronate L, Coronate HL, Coronate HX (above, manufactured by Nippon Polyurethane Kogyo Co., Ltd.), and the like. These isocyanate compounds may be used independently, may be used in mixture of 2 or more types, and it is also possible to use a bifunctional isocyanate compound and a trifunctional or higher functional isocyanate compound in combination. By using a crosslinking agent in combination, it becomes possible to achieve both stable adhesiveness and repelling resistance (adhesion to a curved surface), and a pressure-sensitive adhesive sheet having more excellent adhesion reliability can be obtained.

In addition, when the isocyanate compound (as an isocyanate-based crosslinking agent, a bifunctional isocyanate compound and a trifunctional or higher functional isocyanate compound are used in combination, as the compounding ratio (mass ratio) of both compounds, [bifunctional isocyanate compound]/[trifunctional isocyanate compound]/[trifunctional isocyanate compound] The above isocyanate compounds] (mass ratio) is preferably blended at 0.1/99.9 to 50/50, more preferably 0.1/99.9 to 20/80, still more preferably 0.1/99.9 to 10/90, and 0.1/99.9 to 10/90. Particularly preferred is 5/95, and most preferred is 0.1/99.9 to 1/99.By adjusting and blending within the above range, a pressure-sensitive adhesive layer excellent in stable adhesiveness and repulsion resistance is obtained, resulting in a preferred form.

As said epoxy compound, for example, N,N,N',N'-tetraglycidyl-m-xylenediamine (brand name TETRAD-X, manufactured by Mitsubishi Gas Chemical Co., Ltd.) or 1,3-bis(N,N -Diglycidyl aminomethyl) cyclohexane (trade name TETRAD-C, manufactured by Mitsubishi Gas Chemical Co., Ltd.); and the like.

As said melamine-type resin, hexamethylol melamine etc. are mentioned. Examples of the aziridine derivatives include commercially available products under trade names HDU, TAZM, and TAZO (above, manufactured by Sogo Yakko Co., Ltd.).

As said metal chelate compound, aluminum, iron, tin, titanium, nickel etc. are mentioned as a metal component, Acetylene, methyl acetoacetate, ethyl lactate, etc. are mentioned as a chelate component.

The content of the crosslinking agent used in the present invention is, for example, preferably 0.01 to 10 parts by mass, more preferably 0.1 to 8 parts by mass, and 0.5 It is more preferable to contain from 6 parts by mass to 6 parts by mass, and most preferably from 1.0 to 4.5 parts by mass. When the content is less than 0.01 part by mass, crosslinking by the crosslinking agent becomes insufficient, the cohesive force of the resulting pressure-sensitive adhesive layer decreases, and sufficient heat resistance may not be obtained, and the pressure-sensitive adhesive remains. On the other hand, when the content exceeds 10 parts by mass, the cohesive force of the polymer is high, the fluidity is lowered, and the wettability to the adherend (eg, polarizing plate) becomes insufficient, so that between the adherend and the pressure-sensitive adhesive layer (pressure-sensitive adhesive composition layer) tends to be the cause of the swelling that occurs in In addition, when the amount of the crosslinking agent is large, the peeling charging characteristics tend to decrease. In addition, these crosslinking agents may be used independently, and may mix and use 2 or more types.

The pressure-sensitive adhesive composition may further contain a crosslinking catalyst for more effectively advancing any one of the crosslinking reactions described above. Examples of such a crosslinking catalyst include tin-based catalysts such as dibutyltin dilaurate and dioctyltin dilaurate, tris(acetylacetonate)iron, tris(hexane-2,4-dionato)iron, tris(heptane- 2,4-dionato) iron, tris (heptane-3,5-dionato) iron, tris (5-methylhexane-2,4-dionato) iron, tris (octane-2,4-dionato) iron , tris (6-methylheptane-2,4-dionato) iron, tris (2,6-dimethylheptane-3,5-dionato) iron, tris (nonane-2,4-dionato) iron, tris ( Nonane-4,6-dionato) iron, tris (2,2,6,6-tetramethylheptane-3,5-dionato) iron, tris (tridecane-6,8-dionato) iron, tris ( 1-phenylbutane-1,3-dionato) iron, tris(hexafluoroacetylacetonate) iron, tris(ethylacetoacetate) iron, tris(acetoacetate-n-propyl) iron, tris(acetoacetate isopropyl) ) iron, tris(acetoacetate-n-butyl)iron, tris(acetoacetate-sec-butyl)iron, tris(acetoacetate-tert-butyl)iron, tris(methylpropionylacetate)iron, tris(propionylacetate) Ethyl) iron, tris(propionylacetate-n-propyl)iron, tris(propionylacetate-isopropyl)iron, tris(propionylacetate-n-butyl)iron, tris(propionylacetate-sec-butyl)iron, Tris(propionylacetate-tert-butyl)iron, tris(benzylacetoacetate)iron, tris(dimethylmalonate)iron, tris(diethylmalonate)iron, trimethoxyiron, triethoxyiron, triisopropoxy An iron-based catalyst such as iron or ferric chloride can be used. One type of these crosslinking catalysts may be sufficient, and they may use 2 or more types together.

The content (amount used) of the crosslinking catalyst is not particularly limited, but is preferably about 0.0001 to 1 part by mass, more preferably 0.001 to 0.5 part by mass, based on 100 parts by mass of the (meth)acrylic polymer. When it is within the above range, when the pressure-sensitive adhesive layer is formed, the speed of the crosslinking reaction is fast, the pot life of the pressure-sensitive adhesive composition is also increased, and it becomes a preferable form.

In addition, the pressure-sensitive adhesive composition may contain other known additives, for example, colorants, powders such as 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, particulates, thin materials and the like can be suitably added depending on the use.

The pressure-sensitive adhesive sheet of the present invention is formed by forming the pressure-sensitive adhesive layer on the second resin layer. At this time, crosslinking of the pressure-sensitive adhesive composition is generally performed after application of the pressure-sensitive adhesive composition, but the pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition after crosslinking is formed. It is also possible to transfer to a resin layer or the like.

The method of forming the pressure-sensitive adhesive layer on the second resin layer is not particularly limited, but, for example, the pressure-sensitive adhesive composition (solution) is applied to the resin layer, and the polymerization solvent or the like is removed by drying to form the pressure-sensitive adhesive layer on the resin layer. made by doing Thereafter, curing may be performed for the purpose of adjusting migration of components in the pressure-sensitive adhesive layer or adjusting crosslinking reaction. In addition, when applying the pressure-sensitive adhesive composition onto the resin layer to prepare the pressure-sensitive adhesive sheet, one or more solvents other than the polymerization solvent may be newly added to the pressure-sensitive adhesive composition so that the pressure-sensitive adhesive composition can be applied uniformly on the resin layer.

In addition, as a method for forming the pressure-sensitive adhesive layer at the time of producing the pressure-sensitive adhesive sheet of the present invention, a known method used for the production of pressure-sensitive adhesive tapes is used. Specifically, for example, roll coating, gravure coating, reverse coating, roll brush, spray coating, air knife coating method, extrusion coating method by a die coater, etc. are exemplified.

In general, the thickness of the pressure-sensitive adhesive layer is 3 to 100 μm, preferably 5 to 50 μm. If the thickness of the pressure-sensitive adhesive layer is within the above range, it is preferable because it is easy to obtain a balance between appropriate re-peelability and adhesiveness (adhesiveness).

<Separator>

In the PSA sheet of the present invention, if necessary, a separator can be bonded to the surface of the PSA layer for the purpose of protecting the adhesive surface.

Although there exist paper and a plastic film as a material which comprises the said separator, a plastic film is used suitably from the point which is excellent in surface smoothness. The film is not particularly limited as long as it can protect the pressure-sensitive adhesive layer, and examples include a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, and a vinyl chloride film. A copolymer film, a polyethylene terephthalate film, a polybutylene terephthalate film, a polyurethane film, an ethylene-vinyl acetate copolymer film, etc. are mentioned.

The thickness of the separator is usually about 5 to 200 μm, preferably about 10 to 100 μm. When it is within the above range, it is preferable because bonding workability to the pressure-sensitive adhesive layer and peeling workability from the pressure-sensitive adhesive layer are excellent. If necessary, the separator may be subjected to release and antifouling treatment using a silicone-based, fluorine-based, long-chain alkyl-based or fatty acid amide-based release agent, silica powder, or the like, or antistatic treatment such as coating, mixing, or vapor deposition.

<Top coating layer (antistatic layer)>

The pressure-sensitive adhesive sheet of the present invention has a first resin layer, an adhesive layer, a second resin layer, and a pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive composition in this order, and further includes a surface of the first resin layer having the pressure-sensitive adhesive layer and has a top coating layer on the opposite side, and the top coating layer is formed of a composition for a top coating layer containing polyanilinesulfonic acid as a conductive polymer component, a polyester resin as a binder component, and an isocyanate-based compound as a crosslinking agent. When the pressure-sensitive adhesive sheet has a top coating layer, the antistatic properties of the pressure-sensitive adhesive sheet are improved, resulting in a preferred form.

<Conductive polymer>

The top coating layer is characterized by containing polyanilinesulfonic acid as a conductive polymer component. By using the above conductive polymer, antistatic properties based on the top coating layer and antistatic properties over time can be satisfied. Further, the polyanilinesulfonic acid is "water soluble", but by using an isocyanate-based crosslinking agent described later, it can be immobilized in the top coating layer and the water resistance can be improved. By using the aqueous solution containing the above water-soluble conductive polymer, a top coat layer having excellent surface resistivity over time can be obtained, which is a preferred form. On the other hand, when the conductive polymer used when forming the top coating layer is "water-dispersible", when the top coating layer is formed using the above-mentioned water-dispersible conductive polymer-containing solution, agglomerates are likely to occur, making it impossible to apply uniformly, This is not preferable because the surface resistivity over time tends to decrease remarkably.

The amount of the conductive polymer used is preferably 10 to 200 parts by mass, more preferably 25 to 150 parts by mass, still more preferably 40 to 120 parts by mass, based on 100 parts by mass of the binder included in the top coating layer. If the amount of the conductive polymer used is too small, the antistatic effect may be reduced, and if the amount of the conductive polymer is too large, the adhesion of the top coating layer to the resin layer or the transparency may decrease, which is undesirable. .

The polyanilinesulfonic acid used as the conductive polymer component preferably has a weight average molecular weight (Mw) in terms of polystyrene of 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 higher, and more preferably 5×10 ³ or higher.

As a method of forming the top coating layer, a method of applying and drying (or curing) a composition for the top coating layer (coating material for forming the top coating layer) on the first surface of the resin layer (substrate/support) may be employed, and the top coating layer As the conductive polymer component used in the preparation of the composition for use, polyanilinesulfonic acid, a polyester resin as a binder, and an isocyanate-based crosslinking agent as a crosslinking agent are contained as essential components, and the essential components are in a form dissolved in water (conductive polymer aqueous solution or simply referred to as an aqueous solution) can be preferably used. Such an 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 copolymerizing a monomer having a hydrophilic functional group in a molecule) in water. Examples of the hydrophilic functional group include a sulfo group, an amino group, an amide group, an imino group, a hydroxyl group, a mercapto group, a hydrazino group, a carboxyl group, a quaternary ammonium group, a sulfate ester group (-O-SO ₃ H), a phosphate ester group (eg For example, -O-PO(OH) ₂ ) and the like are exemplified. These hydrophilic functional groups may form a salt.

Moreover, as a commercial item of the said polyanilinesulfonic acid aqueous solution, the trade name "aqua-PASS" by Mitsubishi Rayon Co., Ltd., etc. are illustrated.

The top coating layer disclosed herein contains polyanilinesulfonic acid (polyaniline type) as an essential component as a conductive polymer component, for example, one or two or more other antistatic components (organic conductive materials other than the conductive polymer, inorganic conductive material, antistatic agent, etc.) may be included together. Further, as a preferred embodiment, the top coating layer substantially contains no antistatic components other than the conductive polymer, that is, the top coating layer contains substantially only the conductive polymer. can be carried out.

Examples of the organic conductive substance include cationic antistatic agents having cationic functional groups such as quaternary ammonium salts, pyridinium salts, primary amino groups, secondary amino groups, and tertiary amino groups; anionic antistatic agents having anionic functional groups such as sulfonic acid salts, sulfuric acid ester salts, phosphonic acid salts, and phosphoric acid ester salts; zwitterionic antistatic agents such as alkylbetaine and derivatives thereof, imidazoline and derivatives thereof, and alanine and derivatives thereof; nonionic antistatic agents such as amino alcohol and derivatives thereof, glycerin and derivatives thereof, and polyethylene glycol and derivatives thereof; ion-conductive polymers obtained by polymerizing or copolymerizing a monomer having an ion-conductive group (for example, a quaternary ammonium base) of the above cationic, anionic, or amphoteric ion type; conductive polymers such as polythiophene, polyaniline, polypyrrole, polyethyleneimine, and allylamine-based polymers; can be heard These antistatic agents may be used individually by 1 type, and may be used in combination of 2 or more type.

Examples of the inorganic conductive material include tin oxide, antimony oxide, indium oxide, cadmium oxide, titanium oxide, zinc oxide, indium, tin, antimony, gold, silver, copper, aluminum, nickel, chromium, titanium, iron, cobalt, and copper iodide. , ITO (indium oxide/tin oxide), ATO (antimony oxide/tin oxide), and the like. These inorganic conductive substances may be used individually by 1 type, or may be used in combination of 2 or more types.

Examples of the antistatic agent include cationic antistatic agents, anionic antistatic agents, amphoteric ionic antistatic agents, nonionic antistatic agents, and ions obtained by polymerization or copolymerization of monomers having an ionic conductive group of the cationic type, anionic type, or zwitterionic type. A conductive polymer etc. are mentioned.

<Binder>

The top coating layer is characterized by containing, as an essential component, a polyester resin as a binder. It is preferable that the said polyester resin is a resin material containing polyester as a main component (a component which typically exceeds 50 mass %, Preferably it accounts for 75 mass % or more, for example, 90 mass % or more). The polyesters are typically polyhydric carboxylic acids (typically dicarboxylic acids) having two or more carboxyl groups in one molecule and derivatives thereof (anhydrides, esterified products, halides, etc. of the polyhydric carboxylic acids). One or two or more compounds selected from (polyhydric carboxylic acid component) and one or two or more compounds selected from polyhydric alcohols (typically diols) having two or more hydroxyl groups in one molecule It is preferable to have a structure in which (polyhydric alcohol component) is condensed.

Examples of compounds employable as the polyhydric carboxylic acid component include oxalic acid, malonic acid, difluoromalonic acid, alkylmalonic acid, succinic acid, tetrafluorosuccinic acid, alkylsuccinic acid, (±)-malic acid, meso-tartaric acid, Itaconic acid, maleic acid, methyl maleic acid, fumaric acid, methyl fumaric acid, acetylenedicarboxylic acid, glutaric acid, hexafluoroglutaric acid, methylglutaric acid, glutaconic acid, adipic acid, dithioadipic acid, Methyladipic acid, dimethyladipic acid, tetramethyladipic acid, methyleneadipic acid, muconic acid, galactaric acid, pimelic acid, suberic acid, perfluorosuberic acid, 3,3,6,6- aliphatic dicarboxylic acids such as tetramethylsuberic acid, azelaic acid, sebacic acid, perfluorosebacic acid, brassylic acid, dodecyldicarboxylic acid, tridecyldicarboxylic acid, and tetradecyldicarboxylic acid; Cycloalkyldicarboxylic acids (e.g., 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,4-(2-norbornene)dicarboxylic acid, 5 -Norbornene-2,3-dicarboxylic acid (hymic acid), adamantane dicarboxylic acid, alicyclic dicarboxylic acids such as spiroheptane dicarboxylic acid; phthalic acid, isophthalic acid, dithioisophthalic acid, Methylisophthalic acid, dimethylisophthalic acid, chloroisophthalic acid, dichloroisophthalic acid, terephthalic acid, methylterephthalic acid, dimethylterephthalic acid, chloroterephthalic acid, bromoterephthalic acid, naphthalenedicarboxylic acid, oxofluorenedicarboxylic acid, anthracenedicarboxylic acid , biphenyldicarboxylic acid, biphenylenedicarboxylic acid, dimethylbiphenylenedicarboxylic acid, 4,4"-p-terephenylenedicarboxylic acid, 4,4"-p-cowarel Phenyldicarboxylic acid, bibenzyldicarboxylic acid, azobenzenedicarboxylic acid, homophthalic acid, phenylene diacetic acid, phenylenedipropionic acid, naphthalenedicarboxylic acid, naphthalenedipropionic acid, biphenyl diacetic acid, biphenyl dipropionic acid , 3,3'-[4,4'-(methylenedi-p-biphenylene)dipropionic acid, 4,4'-bibenzyldiacetic acid, 3,3'(4,4'-bibenzyl)dipropionic acid , Aromatic dicarboxylic acids such as oxydi-p-phenylene diacetic acid; acid anhydrides of any of the above-mentioned polyvalent carboxylic acids; esters of any of the above-mentioned polyvalent carboxylic acids (eg, alkyl esters, monoesters, diesters, etc.); acid halides corresponding to any of the above polyvalent carboxylic acids (eg, dicarboxylic acid chlorides); and the like.

Preferable examples of the compound employable as the polyhydric carboxylic acid component include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid, and acid anhydrides thereof; aliphatic dicarboxylic acids and acid anhydrides thereof such as adipic acid, sebacic acid, azelaic acid, succinic acid, fumaric acid, maleic acid, hymic acid, and 1,4-cyclohexanedicarboxylic acid; and lower alkyl esters of the above dicarboxylic acids (for example, esters with monoalcohols having 1 to 3 carbon atoms).

On the other hand, examples of compounds that can be employed as the polyhydric alcohol component include ethylene glycol, propylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and neopentyl glycol. , 1,5-pentanediol, 1,6-hexanediol, 3-methylpentanediol, diethylene glycol, 1,4-cyclohexanedimethanol, 3-methyl-1,5-pentanediol, 2-methyl-1 Diols such as 3-propanediol, 2,2-diethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, xylylene glycol, hydrogenated bisphenol A, and bisphenol A Ryu can be heard. As another example, an alkylene oxide adduct (for example, ethylene oxide adduct, propylene oxide adduct, etc.) of these compounds is mentioned.

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

As said polyester resin, the commercially available product name "Vironal" by Toyobo Co., Ltd., etc. can be used.

The top coating layer may be a resin other than polyester resin (eg, acrylic resin, one or more resins selected from acrylic-urethane resins, acrylic-styrene resins, acrylic-silicone resins, silicone resins, polysilazane resins, polyurethane resins, fluorine resins, and polyolefin resins). As a preferred embodiment of the technology disclosed herein, the binder of the top coating layer substantially contains only a polyester resin. For example, a top coating layer in which the ratio of the polyester resin to the binder is 98 to 100% by mass is preferable. The proportion of the binder in the entire top coating layer can be, for example, 50 to 95% by mass, and is usually suitably 60 to 90% by mass.

<Lubricant>

The top coating layer in the technique disclosed herein preferably uses a fatty acid amide as a lubricant. By using a fatty acid amide as a lubricant, even in a form in which no new peeling treatment (for example, a treatment in which a known peeling treatment agent such as a silicone-based peeling agent or a long-chain alkyl-based peeling agent is applied and dried) is applied to the surface of the top coat layer, Since it is possible to obtain a top coating layer in which sufficient slipperiness and printing adhesiveness are both achieved, it can be a preferred form. The form in which the surface of the top coat layer is not subjected to a new peeling treatment is preferable in that whitening caused by the peeling agent (for example, whitening due to storage under heating and humid conditions) can be prevented. . Moreover, the point of solvent resistance is also advantageous.

Specific examples of the fatty acid amides include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, hydroxystearic acid amide, oleic acid amide, erucic acid amide, N-oleyl palmitic acid amide, N-stearylstearic acid Amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl erucic acid amide, methylol stearic acid amide, methylenebis stearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide , ethylenebisstearic acid amide, ethylenebishydroxystearic acid amide, ethylenebisbehenic acid amide, hexamethylenebisstearic acid amide, hexamethylenebisbehenic acid amide, hexamethylene hydroxystearic acid amide, N,N'-distea Ryl adipic acid amide, N,N'-distearyl sebacic acid amide, ethylene bisoleic acid amide, ethylene bis erucic acid amide, hexamethylene bis oleic acid amide, N,N'-dioleyl adipic acid amide, N,N '-dioleyl sebacic acid amide, m-xylylenebisstearic acid amide, m-xylylenebishydroxystearic acid amide, N,N'-distearylisophthalic acid amide, and the like. These lubricants may be used individually by 1 type, and may be used in combination of 2 or more type.

The ratio of the lubricant to the entire top coat layer can be 1 to 50% by mass, and is usually suitably 5 to 40% by mass. When the content ratio of the lubricant is too small, there is a tendency for slippery property to decrease easily. If the content ratio of the lubricant is too large, printing adhesion may decrease.

The technology disclosed herein may be implemented in a form in which the top coating layer contains other lubricants in addition to the fatty acid amide, to the extent that the application effect is not significantly impaired. Examples of such other lubricants include various waxes such as petroleum wax (paraffin wax, etc.), mineral wax (montan wax, etc.), higher fatty acids (cerotic acid, etc.), and neutral fats (palmitic acid triglyceride, etc.). . Alternatively, in addition to the above wax, a general silicone-based lubricant, a fluorine-based lubricant, or the like may be additionally incorporated. The technology disclosed herein can be preferably carried out in a form substantially free of such silicone-based lubricants, fluorine-based lubricants, and the like. However, to the extent that the application effect of the technique disclosed herein is not significantly impaired, excluding the inclusion of a silicone-based compound used for a purpose other than a lubricant (for example, as an antifoaming agent in a composition for a top coating layer described later) is excluded. not.

<Crosslinking agent>

The top coating layer is characterized by containing an isocyanate-based crosslinking agent as a crosslinking agent. By using the isocyanate-based crosslinking agent, water-soluble polyanilinesulfonic acid, which is an essential component when forming the top coating layer, can be immobilized in the binder, and effects such as excellent water resistance and improved printing adhesion can be realized.

As the isocyanate-based crosslinking agent, it is preferable to use a blocked isocyanate-based crosslinking agent that is stable even in an aqueous solution. As specific examples of the blocked isocyanate-based crosslinking agent, an isocyanate-based crosslinking agent (eg, an isocyanate compound (isocyanate-based crosslinking agent) used in the pressure-sensitive adhesive layer described later) that can be used in the production of a general pressure-sensitive adhesive layer or top coating layer, alcohols, What was blocked with phenols, thiophenols, amines, imides, oximes, lactams, active methylene compounds, mercaptans, imines, ureas, diaryl compounds, and sodium bisulfite can be used.

The top coating layer in the technology disclosed herein may contain, if necessary, an antioxidant, a colorant (pigment, dye, etc.), a rheology modifier (thixotropy production, thickener, etc.), a film formation aid, a surfactant (foamer, etc.), an antiseptic, and an ultraviolet ray. Additives such as absorbents, dispersants, and antiblocking agents may be contained.

<Formation of Top Coating Layer>

The top coating layer is appropriately formed by a method including applying a liquid composition (top coating layer composition) in which essential components such as the conductive polymer component and additives used as necessary are dissolved in an appropriate solvent (such as water) to a resin layer. can be formed. For example, a method of applying the composition for the top coating layer to the first surface of the resin layer, drying it, and performing a curing treatment (heat treatment, ultraviolet treatment, etc.) as necessary can be preferably employed. The NV (non-volatile content) of the composition for the top coating layer can be, for example, 5% by mass or less (typically 0.05 to 5% by mass), and usually 1% by mass or less (typically 0.10 to 1% by mass). %) is appropriate. In the case of forming a top coating layer having a small thickness, it is preferable to set the NV of the top coating layer composition to, for example, 0.05 to 0.50% by mass (eg, 0.10 to 0.40% by mass). By using such a composition for a top coating layer with a low NV, a more uniform top coating layer can be formed.

The solvent constituting the composition for the top coat layer (coating material for forming the top coat layer) is preferably one capable of stably dissolving the components for forming the top coat layer. This solvent may be an organic solvent, water, or a mixed solvent thereof. Examples of the organic solvent include esters such as ethyl acetate; ketones such as methyl ethyl ketone, acetone, and cyclohexanone; cyclic ethers such as tetrahydrofuran (THF) and dioxane; aliphatic or alicyclic hydrocarbons such as n-hexane and cyclohexane; Aromatic hydrocarbons, such as toluene and xylene; aliphatic or alicyclic alcohols such as methanol, ethanol, n-propanol, isopropanol, and cyclohexanol; glycol ethers such as alkylene glycol monoalkyl ethers (eg, ethylene glycol monomethyl ether and ethylene glycol monoethyl ether) and dialkylene glycol monoalkyl ethers; 1 type or 2 or more types selected from these etc. can be used. In a preferred embodiment, the solvent of the top coating layer composition is water or a mixed solvent containing water as a main component (for example, a mixed solvent of water and ethanol).

<Properties of top coating layer>

The thickness of the top coating layer in the technique disclosed herein is typically 3 to 500 nm, preferably 10 to 100 nm, and more preferably 20 to 60 nm. If the thickness of the top coating layer is too small, it becomes difficult to uniformly form the top coating layer (for example, in the thickness of the top coating layer, variation in thickness from place to place increases), and therefore, the appearance of the pressure-sensitive adhesive sheet may be uneven. This can easily happen. On the other hand, if it is too thick, the properties of the resin layer (optical properties, dimensional stability, etc.) may be affected.

In a preferred embodiment of the PSA sheet disclosed herein, the surface resistivity (Ω/□) measured on the surface of the top coating layer is preferably less than 1.0×10 ¹¹ , more preferably less than 5.0×10 ¹⁰ , and further It is preferably less than 1.5×10 ¹⁰ . A pressure-sensitive adhesive sheet exhibiting a surface resistivity within the above range can be suitably used as a pressure-sensitive adhesive sheet used in the process of processing or conveying an article that does not like static electricity, such as a liquid crystal cell or a semiconductor device. In addition, the surface resistivity can be calculated from the surface resistivity measured in an atmosphere of 23°C and 50% RH using a commercially available insulation resistance measuring device.

The PSA sheet disclosed herein preferably has a property that the back side (surface of the top coating layer) can be easily printed with water-based ink or oil-based ink (eg, using an oil-based marking pen). Such an adhesive sheet is used for displaying the identification number of the adherend to be protected by writing it on the adhesive sheet in the process of processing or transporting an adherend (for example, an optical part) performed while the adhesive sheet is attached. Suitable. Therefore, it is preferable that it is an adhesive sheet with excellent printing properties. For example, it is preferable that the solvent has high printability with respect to oil-based ink of the type containing an alcohol and a pigment. In addition, it is preferable that the printed ink is less likely to come off by friction or migration (i.e., has excellent printing adhesion). It is preferable that the pressure-sensitive adhesive sheet disclosed herein has solvent resistance to such an extent that, when the printing is to be corrected or erased, the appearance will not change significantly even if the printing is wiped with alcohol (e.g., ethyl alcohol).

The pressure-sensitive adhesive sheet disclosed herein may be implemented in a form including other layers in addition to the resin layer, the adhesive layer, the pressure-sensitive adhesive layer, and the top coating layer. Examples of the arrangement of such "other layers" include positions between the first surface (rear surface) of the first resin layer and the top coating layer, between the second surface (front surface) of the second resin layer and the pressure-sensitive adhesive layer, and the like. The layer disposed between the back surface of the first resin layer and the top coating layer may be, for example, a layer containing an antistatic component (the top coating layer described above). The layer disposed between the front surface of the second resin layer and the pressure-sensitive adhesive layer may be, for example, an undercoat layer (anchor layer), a top coating layer, or the like that enhances anchoring properties of the pressure-sensitive adhesive layer on the second surface. A pressure-sensitive adhesive sheet having a configuration in which a top coating layer is disposed on the front surface of the second resin layer, an anchor layer is disposed on the top coating layer, and an adhesive layer is disposed thereon.

The optical member of the present invention is preferably protected by the pressure-sensitive adhesive sheet. Since the adhesive sheet has excellent antistatic properties and pick-up properties, it can be used for surface protection applications (adhesive sheet) during processing, conveyance, shipment, etc., and to protect the surface of the optical member (polarizing plate, etc.) it becomes useful In particular, since it can be used for plastic products that are prone to static electricity, it is very useful for antistatic applications in the technical fields related to optical and electronic parts where static electricity is a particularly serious problem.

The pressure-sensitive adhesive sheet of the present invention preferably has a total thickness of 14 to 400 µm, more preferably 40 to 200 µm, and most preferably 55 to 100 µm. If it is within the above range, it is excellent in adhesive properties (repeelability, adhesiveness, etc.), workability, and appearance properties, resulting in a preferable form. In addition, the said total thickness means the sum of the thickness including all layers, such as a resin layer, adhesive layer, adhesive layer, and a top coating layer.

[Example]

Hereinafter, several examples related to the present invention will be described, but the present invention is not intended to be limited to those shown in these specific examples. In addition, "part" and "%" in the following description are based on mass unless otherwise specified.

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

<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. Measurement conditions are as follows.

Sample concentration: 0.2% by mass (THF solution)

Sample injection amount: 10 μl

Eluent: THF

Flow Rate: 0.6ml/min

Measurement temperature: 40℃

column:

sample column; TSKguardcolumn SuperHZ-H (1 pc)+TSKgel SuperHZM-H (2 pcs)

reference column; TSKgel SuperH-RC (1 piece)

Detector: Differential Refractometer (RI)

In addition, the weight average molecular weight was obtained in terms of polystyrene. In addition, also when it is necessary to measure the number average molecular weight (Mn), it was measured similarly to the weight average molecular weight.

<Glass transition temperature (Tg)>

The glass transition temperature (Tg (°C)) was determined by the following formula using the values in the following literature 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 (℃) is the glass transition temperature of the copolymer, Wn (-) is the weight fraction of each monomer, Tgn (℃) is the glass transition temperature of the homopolymer by each monomer, and n represents the type of each monomer ]

Literature value:

2-Ethylhexylacrylate (2EHA): -70°C

n-Butylacrylate (BA): -55°C

2-hydroxyethyl acrylate (HEA): -15°C

Acrylic Acid (AA): 106°C

Methoxy polyethylene glycol monomethacrylate (PME-400): -60℃

In addition, reference was made to "Synthesis/Design of Acrylic Resins and Development of New Uses" (published by Central Management Development Center), "Polymer Handbook" (John Wiley & Sons), and catalog values of monomer manufacturers as literature values.

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

First, sheets of (meth)acrylic polymer with a thickness of 20 μm were laminated to a thickness of about 2 mm, and this was punched to φ 7.9 mm to produce cylindrical pellets, which were used as samples for measuring glass transition temperature (Tg).

Using the measurement sample, the measurement sample is fixed to a jig of a φ 7.9 mm parallel plate, and the temperature dependence of the loss modulus (G") is measured by a dynamic viscoelasticity measuring device (Rheometrics, ARES), , the temperature at which the obtained G" curve has a maximum was defined as the glass transition temperature (Tg (° C.)). Measurement conditions are as follows.

Measurement: Shear Mode

Temperature range: -70°C to 150°C

Temperature rising range: 5°C/min

Frequency: 1Hz

<Thickness measurement>

It was measured using a digital micrometer (manufactured by Anritsu Corporation, product name "KC-351C").

<Tensile Strength>

In accordance with JIS C 2318, it was measured using a tensile tester (manufactured by Shimadzu Corporation, product name "Autograph").

<Storage modulus of adhesive layer>

The adhesive layer was laminated to have a thickness of about 2 mm, and this was punched to φ 7.9 mm to produce cylindrical pellets, which were used as samples for measurement. Using the measurement sample, the measurement sample was fixed to a jig of a φ7.9 mm parallel plate, and the storage modulus (G') at 23°C was measured by a dynamic viscoelasticity measuring device (Rheometrics, ARES). did Measurement conditions are as follows.

Measurement: Shear Mode

Frequency: 1Hz

The storage 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, more preferably 1.0 It is more than ×10 ⁵ Pa and less than 1.0 × 10 ⁶ Pa. When it is within the above range, the pick-up property of the pressure-sensitive adhesive sheet becomes good, and it becomes a preferable form.

<Measurement of Surface Resistivity>

The measurement was conducted in accordance with JIS-K-6911 using a resistivity meter (Mitsubishi Chemical Analytics, Model Hi Resta UP MCP-HT450) in an atmosphere of a temperature of 23°C and a humidity of 50% RH.

The surface resistivity (Ω/□) in the present invention is preferably less than 1.0 × 10 ¹¹ in both initial and room temperature (RT) (23 ° C × 50% RH) × 1 week (7 days) stationary cases. , more preferably less than 5.0×10 ¹⁰ , still more preferably less than 1.5×10 ¹⁰ . A pressure-sensitive adhesive sheet exhibiting a surface resistivity within the above range can be suitably used as a pressure-sensitive adhesive sheet used in the process of processing or conveying an article that does not like static electricity, such as a liquid crystal cell or a semiconductor device.

<Measurement of peeling electrification voltage (polarizing plate side)>

The pressure-sensitive adhesive sheet 1 according to each example is cut into a size of 70 mm in width and 130 mm in length, and the release liner is peeled off, and then, as shown in Fig. 2, an acrylic plate 3 (manufactured by Mitsubishi Rayon Co., Ltd.) On the surface of the polarizing plate 2 (manufactured by Nitto Denko, SEG1423DU polarizing plate, width: 70 mm, length: 100 mm) bonded to a trade name "Acrylite", thickness: 1 mm, width: 70 mm, length: 100 mm), an adhesive sheet (1) ) was compressed with a hand roller so that one end of the polarizing plate 2 protrudes 30 mm from the end of the polarizing plate 2.

After this sample was left to stand for one day in an environment of 23°C x 50% RH, it was set at a predetermined position on the sample holder 4 with a height of 20 mm. The end of the PSA sheet 1 protruding 30 mm from the polarizing plate 2 was fixed to an automatic winding machine (not shown), and peeled at a peel angle of 150° and a peel speed of 10 m/min. The potential on the surface of the adherend (polarizing plate) generated at this time was measured by a potential measuring device 5 (model "KSD-0103" manufactured by Kasuga Denki) fixed at a position of 100 mm in height from the center of the polarizing plate 2. The initial polarizing plate peeling electrification voltage” was measured. The measurement was performed in an environment of 23°C and 50% RH.

The peeling electrification voltage (kV) (absolute value) in the present invention is preferably 1 or less, more preferably 0.9 or less, still more preferably 0.5 or less. When it is within the above range, damage to, for example, a liquid crystal driver or the like can be prevented, and this is a preferred mode.

<Measurement of Back Adhesion (A)>

As shown in FIG. 3, the PSA sheet 1 according to each example is cut into a size of 70 mm in width and 100 mm in length, and the adhesive side of the PSA sheet 1 (the side on which the PSA layer 20 is installed) 20A was fixed on the SUS304 stainless steel plate 132 using the double-sided adhesive tape 130. A single-sided adhesive tape (manufactured by Nitto Denko, trade name “No.31B”, width 19 mm) having an acrylic adhesive 162 on a resin layer film (first resin layer, adhesive layer, second resin layer in that order) 164 ( 160) was cut to a length of 100 mm. The adhesive face 162A of the adhesive tape 160 is pressed against the back surface of the adhesive sheet 1 (that is, the surface of the top coating layer 14) 1A at a pressure of 0.25 MPa and a speed of 0.3 m/min. did This was left to stand for 30 minutes on conditions of 23 degreeC and 50% RH. Thereafter, using a universal tensile tester, the adhesive tape 160 was peeled from the back surface 1A of the adhesive sheet 1 under conditions of a peeling speed of 0.3 m/min and a peeling angle of 180°. ) [N/19 mm] was measured.

Further, 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 adhesive force is less than 3.0 N/19 mm, it is not preferable because sufficient adhesive force cannot be obtained, pick-up properties deteriorate, and peeling workability of the protective film deteriorates.

<Measurement of adhesive strength (B) of large polarizing plate>

As an adherend, a plane polarizing plate (TAC polarizing plate manufactured by Nitto Denko, SEG1425DU) having a width of 70 mm and a length of 100 mm was prepared. The pressure-sensitive adhesive sheet for each example was cut into a size of 25 mm in width and 100 mm in length, and the adhesive surface was pressed against the polarizing plate at a pressure of 0.25 MPa and a speed of 0.3 m/min. After leaving this for 30 minutes in an environment of 23°C and 50% RH, the pressure-sensitive adhesive sheet was peeled off from the polarizing plate using a universal tensile tester under the conditions of a peeling speed of 0.3 m/min and a peeling angle of 180° under the same environment. Adhesion (B) [N/25 mm] was measured.

Further, the adhesive force (B) is preferably 4.5 N/25 mm or less, more preferably 4 N/25 mm or less, still more preferably 3.5 N/25 mm or less, and most preferably 3 N/25 mm or less. When the adhesive force exceeds 4.5 N/25 mm, peeling workability is poor, which is not preferable.

<Pickup characteristics>

As shown in FIG. 4, the PSA sheet 1 according to each example is cut into a size of 50 mm in width and 100 mm in length, and the adhesive side of the PSA sheet 1 (the side on which the PSA layer 20 is installed) 20A was pressed onto a plain polarizing plate (TAC polarizing plate, SEG1425DU manufactured by Nitto Denko Corporation) 50 at a pressure of 0.25 MPa and a speed of 0.3 m/min.

The single-sided adhesive tape 60 (manufactured by Nitto Denko, trade name "No. 31B") was cut to a width of 19 mm and a length of 50 mm. The pressure-sensitive adhesive layer (adhesive surface) 62 of the pressure-sensitive adhesive tape 60 is hand-pressed onto the center of the back surface (ie, the surface of the top coating layer 14) having a width of 50 mm of the pressure-sensitive adhesive sheet 1 so that the end portion protrudes 30 mm. did This was left to stand for 10 seconds on conditions of 23 degreeC and 50% RH. Then, the single-sided adhesive tape 60 was peeled off by hand, and the peeling state (pickup property) of the adhesive sheet 1 was evaluated.

The evaluation criterion was ○ when the adhesive sheet could be peeled off, and × when the adhesive sheet remained without peeling.

<Amount of Warpage>

As shown in Fig. 5, the PSA sheet 1 according to each example is cut into a size of 20 mm in width and 150 mm in length, and the adhesive surface of this PSA sheet 1 faces outward, and the ends are made by Nitto Denko Co., Ltd. No. It was fixed to the glass plate (G) with .31B tape (T). The height (H1) of the center position of the adhesive sheet at that time was measured. Next, a load (L) of 4.8 g was placed on the center position, and the height (H2) of the center position of the PSA sheet at that time was measured. The amount of warpage [mm] was determined by the following formula.

Warpage amount = H1-H2 [mm]

In addition, the warp amount is preferably 30 mm or less, more preferably 25 mm or less, still more preferably 20 mm or less. When the amount of warpage exceeds 30 mm, the optical member to which the pressure-sensitive adhesive sheet is bonded tends to warp during the conveyance process, which is not preferable.

<Evaluation of printing properties (printing adhesion)>

After printing on the surface of the top coating layer using Shachihata X stamper under a measurement environment of 23 ° C × 50% RH, cellophane tape (registered trademark) manufactured by Nichiban Co., Ltd. was affixed on the printing, and then, Peeling is carried out under conditions of a peeling speed of 30 m/min and a peeling angle of 180°. After that, 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 printing property), and the case where 50% or more of the printing area remained without peeling was evaluated as ○ (good printing property). did

Below, the manufacturing method of the top coating layer, adhesive composition (adhesive solution), and adhesive sheet (surface protection film) was described.

[Example 1]

<Manufacture of resin layer film (in order of first resin layer, adhesive layer, and second resin layer)>

In a reaction vessel equipped with a cooling tube, a nitrogen inlet tube, a thermometer and a stirring device, 100 parts by mass of butyl acrylate (BA), 5.0 parts by mass of acrylic acid (AA), and 0.075 mass part of 2-hydroxyethyl acrylate (2HEA) Part, 0.3 mass part of 2,2' azobisisonitrile, and ethyl acetate were added, and it was made to react at 60 degreeC for 6 hours, stirring under nitrogen gas stream, and the acrylic polymer solution of weight average molecular weight 1.63 million was obtained. With respect to 100 parts by mass of the polymer solid content of this acrylic polymer solution, 0.6 parts by mass of an isocyanate-based polyfunctional compound (trade name: Coronate L, manufactured by Nippon Polyurethane Kogyo Co., Ltd.), and a silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., 0.08 parts by mass of (trade name: KBM403) was added to prepare an acrylic adhesive 1 composition solution.

As a resin layer, the acrylic adhesive composition 1 solution was coated on a polyester resin film (trade name: E5000, manufactured by Toyobo Co., Ltd., thickness: 38 μm, tensile strength: 208 MPa), heated at 90° C., to a thickness of 20 μm. An adhesive layer was formed. The storage modulus of the obtained adhesive layer at 23°C was 1.0×10 ⁵ Pa.

Thereafter, a polyester-based resin film (trade name: E5000, manufactured by Toyobo Co., Ltd., 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>

To a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet pipe, and a condenser, 95 parts by mass of 2-ethylhexyl acrylate (2EHA), 5 parts by mass of 2-hydroxyethyl acrylate (HEA), and 2 as polymerization initiators 0.2 parts by mass of 2'-azobisisobutyronitrile and 150 parts by mass of ethyl acetate were introduced, nitrogen gas was introduced while gently stirring, and polymerization was carried out for 6 hours while maintaining the liquid temperature in the flask at around 65°C, ( A meth)acrylic polymer solution (40% by mass) was prepared. The acrylic polymer had a weight average molecular weight of 550,000 and a glass transition temperature (Tg) of -68°C.

The acrylic polymer solution (40% by mass) was diluted to 20% by mass with ethyl acetate, and to 500 parts by mass (100 parts by mass of solid content) of this solution, as a crosslinking agent, an isocyanurate form of hexamethylene diisocyanate (Nippon Polyurethane Kogyo Co., Ltd., trade name: Coronate HX (C/HX)) 4 parts by mass (solid content: 4 parts by mass), dibutyltin dilaurate (1% by mass ethyl acetate solution) 2 parts by mass (solid content: 0.02 parts by mass) as a crosslinking catalyst was added, and mixing and stirring were performed to prepare an acrylic pressure-sensitive adhesive 1 solution.

<Preparation of Solution for Top Coating Layer (Top Coating 1)>

As a binder, polyester resin Vironal MD-1480 (25% aqueous solution, manufactured by Toyobo Co., Ltd.), as a conductive polymer, polyanilinesulfonic acid (aqua-PASS, weight average molecular weight: 40,000, manufactured by Mitsubishi Rayon Co., Ltd.), diisopropyl as a crosslinking agent An isocyanurate of hexamethylene diisocyanate blocked with an amine, as a lubricant, oleic acid amide in a mixed solvent of water / ethanol (1/3), a binder in a solid amount of 100 parts by mass, and a conductive polymer in a solid amount of 75 30 parts by mass of a mass part and a crosslinking agent were added in terms of solid content, and 10 parts by mass and a lubricant were added in terms of solid content, and the mixture was stirred for about 20 minutes and thoroughly mixed. In this way, a solution for the top coating layer (Top Coating 1) having an NV of about 0.4% was prepared.

<Manufacture of resin layer film with top coating layer (top coating layer, first resin layer, adhesive layer, and second resin layer in this order)>

Corona treatment was performed on one side of the resin layer film, and the solution for the top coating layer was applied to the corona-treated side so that the thickness after drying was 30 nm. By heating and drying this coating material at 130 degreeC for 1 minute, the resin layer film with a top coat layer (top coat layer, 1st resin layer, adhesive layer, and 2nd resin layer in that order) was produced.

<Preparation of adhesive sheet (surface protection film)>

The acrylic pressure-sensitive adhesive solution is applied to the surface opposite to the top coating layer of the resin layer film with the top coating layer (top coating layer, first resin layer, adhesive layer, second resin layer in that order), and heated at 130 ° C. for 1 minute, A pressure-sensitive adhesive layer having a thickness of 20 μm was formed. Subsequently, the silicone-treated surface of a polyethylene terephthalate film (thickness: 25 μm), which is a separator that has undergone silicone treatment on one side, was bonded to the surface of the pressure-sensitive adhesive layer to prepare an adhesive sheet (surface protection film).

[Example 8]

<Preparation of polyester-based pressure-sensitive adhesive solution>

To a four-necked separable flask equipped with a stirring blade, a thermometer, and a reaction by-product separator tube, 140.0 parts by mass of polycarbonate diol (manufactured by Kuraray Co., Ltd., trade name: PNOC-2000, hydroxyl value: 53.7 KOHmg/g), dimer 60 parts by mass of diol (manufactured by Unichema, trade name: PRIPOL-2033), 9.8 parts by mass of trimethylolpropane, 55.4 parts by mass of sebacic acid, and 0.1 part by mass of tetran-butyl titanate as a catalyst were added, and water as a reaction by-product was discharged. In the presence of a small amount of xylene as a solvent, the liquid temperature in the flask was raised to 180°C while slowly starting stirring, and maintained at this temperature. After a while the outflow separation of the water was seen and the reaction was seen to proceed. Thereafter, a polymerization reaction was performed for about 19 hours to obtain polyester. This polyester had a number average molecular weight of 19000 and a degree of dispersion of 3.9.

The polyester was diluted to 30 mass% with a mixed solution (ethyl acetate/toluene = 1/1: mass ratio), and trimethylolpropane/hexamethylene diisocyanate trimer adduct (Nippon Polyurethane Industry Co., Ltd.) was added to 100 parts by mass of this solution. 2.4 parts by mass of Shah Co., Ltd., trade name: Coronate HL) was added, mixed and stirred, and a polyester-based pressure-sensitive adhesive composition (solution) was prepared.

<Preparation of adhesive sheet (surface protection film)>

The polyester adhesive solution was applied to the surface opposite to the top coating layer of the resin layer film with top coating layer (top coating layer, first resin layer, adhesive layer, second resin layer in that order), and heated at 130° C. for 1 minute. Thus, a pressure-sensitive adhesive layer having a thickness of 20 μm was formed. Subsequently, the silicone-treated surface of a polyethylene terephthalate film (thickness: 25 μm), which is a separator that has undergone silicone treatment on one side, was bonded to the surface of the pressure-sensitive adhesive layer to prepare a pressure-sensitive adhesive sheet (surface protection film).

[Example 9]

<Preparation of urethane-based pressure-sensitive adhesive solution>

As a polyol, 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), trimethylolpropane/tolylene diisocyanate trimer as a polyfunctional isocyanate compound Adduct (manufactured by Nippon Polyurethane Kogyo Co., Ltd., trade name: Coronate L) 13 parts by mass (solid content), catalyst (manufactured by Nippon Chemical Industry Co., Ltd., trade name: ferric ferric) 0.04 part by mass, as a diluting solvent 210 parts by mass of ethyl acetate were blended and stirred with a disper to obtain a urethane-based pressure-sensitive adhesive composition (solution).

<Preparation of adhesive sheet (surface protection film)>

The urethane-based pressure-sensitive adhesive solution is applied to the surface opposite to the top coating layer of the resin layer film with the top coating layer (top coating layer, first resin layer, adhesive layer, second resin layer in that order), and heated at 130 ° C. for 1 minute, A pressure-sensitive adhesive layer having a thickness of 20 μm was formed. Subsequently, the silicone-treated surface of a polyethylene terephthalate film (thickness: 25 μm), which is a separator that has undergone silicone treatment on one side, was bonded to the surface of the pressure-sensitive adhesive layer to prepare an adhesive sheet (surface protection film).

[Comparative Example 1]

<Preparation of Solution for Top Coating Layer (Top Coating 3)>

Polyester resin Vironal MD-1480 (25% aqueous solution, manufactured by Toyobo Co., Ltd.) as a binder, 0.5% poly(3,4-ethylenedioxythiophene) (PEDOT) as a conductive polymer, and polystyrene sulfonate (weight average molecular weight: 150,000) ) (PSS) 0.8% aqueous solution (Bytron P, manufactured by H. C. Stark) is mixed with water / ethanol (1/1) in a mixed solvent, 100 parts by mass of a binder in terms of solid content, and 50 parts by mass of conductive polymer in terms of solid content A mass part and 5 parts by mass of a melamine-based crosslinking agent were added, and the mixture was stirred for about 20 minutes and sufficiently mixed. In this way, a solution for the top coating layer (Top Coating 3) having an NV of about 0.4% was prepared.

[Comparative Example 3]

<Preparation of solution for top coating layer (top coating 5)>

In a water-alcohol solvent, an antistatic agent containing a cationic polymer (manufactured by Konishi Co., Ltd., trade name "Bon Dip-P base material") and an epoxy resin as a curing agent (manufactured by Konishi Co., Ltd., trade name "Bon Dip-P curing agent") ”) in a mass ratio of 100:46.7 based on NV (top coating 5) was prepared.

Corona treatment was performed on one side of the resin layer film having the configuration shown in Table 3, and the solution for the top coating layer (top coating 5) was applied to the corona treatment side so that the thickness after drying was 60 nm, and heated at 130 ° C. for 1 minute. and dried to form a top coating layer. Subsequently, as a lubricant, a long-chain alkyl carbamate-based peeling agent (manufactured by Ipposha Yushi Kogyo Co., Ltd., trade name "Pyrroyl 1010") was applied to the surface of the top coating layer so that the NV was 40 nm, It dried by heating at 130 degreeC for 1 minute, and the top coating layer which becomes a two-layer structure was formed.

[Comparative Example 5]

<Manufacture of resin layer film (in order of first resin layer, adhesive layer, and second resin layer)>

In a reaction vessel equipped with a cooling tube, a nitrogen inlet tube, a thermometer and a stirring device, 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) And, 0.2 mass part of 2,2' azobisisonitrile and ethyl acetate were added, and it was made to react at 60 degreeC for 6 hours, stirring under a nitrogen gas stream, and obtained the acrylic polymer solution with a weight average molecular weight of 1,100,000. Based on 100 parts by mass of the polymer solid content of this acrylic polymer solution, 1.0 parts by mass of an epoxy compound [manufactured by Mitsubishi Gas Chemical Co., Ltd., TETRAD C] and 40 parts by mass of a urethane acrylate compound [manufactured by Nippon Kose Chemical Industry Co., Ltd., UV-1700B] Parts by mass, acrylate compound [manufactured by Nippon Kayaku Co., Ltd., KAYARAD DPCA-120] 40 parts by mass, 1-hydroxycyclohexylphenyl ketone (trade name: IRGACURE 184) [manufactured by Ciba Specialty Chemicals Co., Ltd.] By adding 7 parts by mass, an acrylic adhesive 2 composition solution was prepared.

As a resin layer, the acrylic adhesive 2 composition solution was coated on a polyester resin film (trade name: E5000, manufactured by Toyobo Co., Ltd., thickness: 38 μm, tensile strength: 208 MPa), heated at 90° C., to a thickness of 12 μm. An adhesive layer was formed.

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

[Examples 2 to 10 and Comparative Examples 1 to 5]

Based on the formulation contents of Tables 1 and 2, it was carried out similarly to Example 1, and the adhesive sheet (surface protection film) was produced. In addition, other additives not blended in Example 1 (for example, antistatic components blended during production of the pressure-sensitive adhesive solution, etc.) were blended during production of the pressure-sensitive adhesive solution. In Comparative Example 4, only the second resin layer shown in Table 4 was used instead of the resin layer film. The compounding quantity in Table 1 and Table 2 showed solid content.

Tables 3 and 4 show the results of the above-described various measurements and evaluations on the PSA sheets according to Examples and Comparative Examples.

In addition, the abbreviation in Table 1 and Table 2 is demonstrated below.

2EHA: 2-ethylhexyl acrylate

BA: n-butyl acrylate

HEA: 2-hydroxyethyl acrylate

AA: acrylic acid

PME-400: Methoxypolyethylene glycol monomethacrylate

C/HX: isocyanurate of hexamethylene diisocyanate (manufactured by Nippon Polyurethane Co., Ltd., trade name: Coronate HX)

D201: hexamethylene diisocyanate-based bifunctional isocyanate (manufactured by Asahi Kasei, trade name: Duranate D-201)

C/L: trimethylolpropane/tolylene diisocyanate trimer adduct (manufactured by Nippon Polyurethane Co., Ltd., trade name: Coronate L)

MT: 4,4'-diphenylmethane diisocyanate (manufactured by Nippon Polyurethane Co., Ltd., trade name: Milionate MT)

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

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

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

Polyester-based resin 38 μm: (manufactured by Toyobo Co., Ltd., trade name: E5000, tensile strength: 208 MPa)

Polyester-based resin 75 μm: (manufactured by Toyobo Co., Ltd., trade name: E5000, tensile strength: 188 MPa)

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

From the above evaluation results, in all examples, by using the PSA sheet having the desired thickness ratio, the storage modulus of the adhesive layer, the PSA layer, the top coating layer, etc., the antistatic property, adhesive property, pick-up property, warpage amount, and printing adhesion were improved. excellence was confirmed. On the other hand, in Comparative Example, since no PSA sheet having a desired thickness ratio, PSA layer, top coating layer, or the like was not used, it was not possible to obtain a PSA sheet that satisfies all characteristics.

The pressure-sensitive adhesive sheet disclosed herein is used as a component of a liquid crystal display panel, a plasma display panel (PDP), an organic electroluminescence (EL) display, a touch panel display, and the like during manufacture and transport of an optical member. It is suitable as an adhesive sheet (surface protection film) for protecting members. In particular, it is useful as an adhesive sheet (adhesive sheet for optics) applied to optical members such as a polarizing plate (polarizing film) for a liquid crystal display panel, a wave plate, a retardation plate, an optical compensation film, a luminance enhancing film, a light diffusing sheet, and a reflective sheet. do.

DESCRIPTION OF SYMBOLS 1: Adhesive sheet (surface protection film) 1A: Surface of top coating layer
2: polarizer 3: acrylic plate
4: fixing table 5: electric potential meter
6: first resin layer 7: adhesive layer
8: second resin layer
12: resin layer film (first resin layer + adhesive layer + second resin layer)
14: top coating layer 20: adhesive layer
20A: adhesive surface 50: plain polarizer
60: single-sided adhesive tape 62: adhesive layer (adhesive side)
64: base material 130: double-sided adhesive tape
132: stainless steel plate 160: single-sided adhesive tape
162: acrylic adhesive (adhesive layer) 162A: adhesive surface
164: resin layer film (first resin layer + adhesive layer + second resin layer)
T: No.31B tape G: Glass plate
H : Height from center position L : Load

Claims (6)

It has a 1st resin layer, an adhesive layer, a 2nd resin layer, and the adhesive layer formed from the adhesive composition in this order,
The value of the ratio of the thickness of the adhesive 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,
The adhesive layer has a storage modulus at 23° C. of 1.0×10 ⁴ Pa or more and less than 5.0×10 ⁷ Pa,
A top coating layer is provided on the surface opposite to the surface of the first resin layer having the pressure-sensitive adhesive layer,
The top coating layer is formed of a composition for a top coating layer containing polyanilinesulfonic acid as a conductive polymer component, a polyester resin as a binder component, and an isocyanate-based compound as a crosslinking agent;
The pressure-sensitive adhesive sheet according to claim 1 , wherein the composition for the top coating layer further comprises a fatty acid amide as a lubricant. delete According to claim 1,
An adhesive sheet characterized in that at least one of the resin layers is a polyester film. According to claim 1,
The pressure-sensitive adhesive composition contains at least one selected from the group consisting of acrylic pressure-sensitive adhesives, urethane-based pressure-sensitive adhesives, and polyester-based pressure-sensitive adhesives. According to claim 1,
The pressure-sensitive adhesive sheet characterized in that the pressure-sensitive adhesive composition contains an antistatic component. An optical member characterized by being protected by the adhesive sheet according to any one of claims 1 and 3 to 5.

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