JP2016121310A - Pressure-sensitive adhesive sheet and optical member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure-sensitive adhesive sheet capable of achieving improvement in antistatic properties and pickup properties, and an optical member protected by the pressure-sensitive adhesive sheet.SOLUTION: The pressure-sensitive adhesive sheet includes 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 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 storage modulus at 23°C of the adhesive layer is 1.0×10Pa or more and less than 5.0×10Pa. The pressure-sensitive adhesive sheet also includes a top coat layer on a surface of the first resin layer which is opposite to the surface having the pressure-sensitive adhesive layer. The top coat layer is formed of a composition for the top coat layer which contains a polyaniline sulfonic acid as a conductive polymer component, a polyester resin as a binder component, and an isocyanate compound as a crosslinking agent. The pressure-sensitive adhesive layer contains an organopolysiloxane having an oxyalkylene chain.SELECTED DRAWING: None

Description

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

  The pressure-sensitive adhesive sheet of the present invention includes a polarizing plate, a wavelength plate, a retardation plate, an optical compensation film, a reflection sheet, a brightness enhancement film, a cover glass, a cover sheet, and a hard coat film that are used for liquid crystal displays, organic EL displays, touch panel displays, and the like. It is useful as a surface protective film used for the purpose of protecting the surface of optical members such as transparent conductive glass and transparent conductive film.

  In recent years, when optical components / electronic components are transported or mounted on a printed circuit board, they are transferred in a state where individual components are packaged with a predetermined sheet or in a state where an adhesive tape is attached. Among these, surface protective films are particularly widely used in the field of optical and electronic components.

  A surface protective film is generally used for the purpose of bonding to an adherend via an adhesive applied to the support film side and preventing scratches and dirt generated during processing and transport of the adherend (Patent Document 1). ). For example, a panel of a liquid crystal display is formed by bonding an optical member such as a polarizing plate or a wave plate to a liquid crystal cell via an adhesive. As for these optical members, the surface protection film is bonded together through the adhesive, and the damage | wound and dirt which arise at the time of a process and conveyance of a to-be-adhered body are prevented.

  Then, the protective film is peeled off and removed at a stage where the protective film is no longer necessary, for example, by bonding the optical member to the liquid crystal cell. In general, since a protective film and an optical member are made of a plastic material, they have high electrical insulation and generate static electricity during friction and peeling. Accordingly, static electricity is generated when the protective film is peeled off from the optical member such as a polarizing plate. When a voltage is applied to the liquid crystal while static electricity remains, the alignment of liquid crystal molecules is lost or the panel is damaged. Also, the presence of static electricity can be a factor that attracts dust and reduces workability. Under such circumstances, the surface protection film is subjected to an antistatic treatment. For example, as a surface layer (topcoat layer, back layer) of the surface protection film, an antistatic layer is formed or an antistatic coating is applied. Thus, an antistatic function is provided (see Patent Documents 2 and 3).

  In recent years, PEDOT (poly (3,4-ethylenedioxythiophene) / PSS (polystyrene sulfonate) (polythiophene type) system is used as a conductive polymer used to impart an antistatic function to the surface layer of the surface protective film. However, when an antistatic layer is formed using the conductive polymer, PSS (corresponding to a dopant) is desorbed from PEDOT over time, and the surface resistivity is increased. There is a possibility that a rise in stripping band voltage or a problem such as an increase (deterioration) in surface resistivity due to oxidation deterioration or light deterioration may occur.

  Further, when the surface resistivity or the like is increased (deteriorated), static electricity is generated when the surface protective film is peeled off from the adherend, which may cause a problem.

  In addition, this surface protective film is peeled off and removed when it is no longer needed, but as the liquid crystal display panel becomes larger and thinner, damage to the polarizing plate and the liquid crystal cell is likely to occur during the peeling process. In addition, there is a demand for light releasability, pick-up property, and the like so as to have an appropriate adhesive force so as not to be lifted at the time of peeling and to enable re-peeling. In particular, in recent years, the optical members constituting the display have become thinner with the thinning of the display. With an optical member having a thickness of 150 μm or less, or even a thin thickness of 100 μm or less, the optical member is bent during the transport process. This makes it impossible to carry. In addition, there is a problem that the optical member cannot be cleanly bonded to another member. In order to avoid these problems, it is possible to suppress the deflection by increasing the thickness of the surface protection film, but since the peeling becomes heavier by increasing the thickness, the surface protection film is removed when the surface protection film is no longer needed. There is a problem that the pick-up tape cannot be picked up when it is peeled off. Therefore, there is a demand for a pressure-sensitive adhesive sheet that can suppress light deflection and can be easily peeled off and picked up so that re-peeling is possible.

JP 2003-334911 A JP 2000-26817 A JP 2008-255332 A

  In view of the above circumstances, the present invention provides a pressure-sensitive adhesive sheet that can improve antistatic properties and pickup properties, and an optical member that is 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 from the pressure-sensitive 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 resin layer and the thickness of the second resin layer is 0.50 or less, and the storage elastic modulus at 23 ° C. of the adhesive layer is 1.0 × 10 ⁴ Pa or more and less than 5.0 × 10 ⁷ Pa, and the first resin layer has a topcoat layer on the surface opposite to the surface having the pressure-sensitive adhesive layer, and the topcoat layer is electrically conductive. It is formed from a composition for a top coat layer containing a polyaniline sulfonic acid as a functional polymer component, a polyester resin as a binder component, and an isocyanate compound as a crosslinking agent, and the pressure-sensitive adhesive composition has an oxyalkylene chain. Organopoly having Characterized in that it contains a Rokisan.

  In the pressure-sensitive adhesive sheet of the present invention, the topcoat layer composition preferably further contains a fatty acid amide as a lubricant.

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

  In the pressure-sensitive adhesive sheet of the present invention, the pressure-sensitive adhesive composition preferably contains an acrylic pressure-sensitive adhesive and / or a urethane pressure-sensitive adhesive.

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

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

  According to the pressure-sensitive adhesive sheet of the present invention, it has a resin layer film (a first resin layer, an adhesive layer, and a second resin layer in this order, which may be referred to as a laminated film) in which a resin layer is laminated via an adhesive layer. Accordingly, stress relaxation can be achieved at the adhesive layer portion against deformation when the pressure-sensitive adhesive sheet is peeled off, and pickup can be performed with a lower peeling force (adhesive strength) than that of the resin layer alone. In addition, with the above laminated structure, the amount of flexure of the laminated film can be improved (reduced amount of flexure) compared to the amount of flexure of each individual resin layer film, improving the problem of poor conveyance due to bending or deformation in the transport process. It is possible to achieve the improvement of manufacturing efficiency. In addition, the resin layer film has a top coat layer containing a specific raw material on one side and an adhesive layer containing a specific raw material on the other side, so that it has excellent antistatic properties and pick-up properties. An adhesive sheet is obtained and is a preferred embodiment.

It is a schematic sectional drawing of the protective film by preferable embodiment of this invention. It is explanatory drawing which shows the measuring method of peeling voltage. It is explanatory drawing which shows the measuring method of back surface adhesive force (A). It is explanatory drawing which shows the peeling method of the adhesive sheet which concerns on one embodiment. It is explanatory drawing which shows the measuring method of deflection amount.

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

<Adhesive sheet (surface protective film)>
FIG. 1 is a schematic cross-sectional view of an adhesive sheet according to a preferred embodiment of the present invention. The pressure-sensitive adhesive sheet 1 has a first resin layer 6, an adhesive layer 7, and a second resin layer 8 (the first resin layer, the adhesive layer, and the second resin layer in this order are “resin And a pressure-sensitive adhesive layer 20 in this order, and a top coat on the surface of the first resin layer 6 opposite to the surface having the pressure-sensitive adhesive layer 20. It has a layer 14. The pressure-sensitive adhesive sheet 1 is a laminate in which the first resin layer 6 and the second resin layer 8 are laminated via an adhesive layer 7 and further has a pressure-sensitive adhesive layer 20 and a topcoat layer 14. . Further, it is bonded to an adherend (for example, an optical member) by the pressure-sensitive adhesive layer 20. In addition, although not shown in figure, it is a preferable aspect that a separator is affixed on the surface of the adhesive layer 20 until it adheres to a to-be-adhered body.

<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 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). The thickness of the resin layer is preferably 1 to 50 μm, more preferably 4 to 38 μm, and most preferably 10 to 25 μm. 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 in the said range, coexistence of suppression of the deflection amount of an adhesive sheet and pick-up property will be attained, and it becomes a preferable aspect.

  Further, the tensile strength in the MD direction (flow direction) of at least one of the resin layers can be set to any appropriate value. The tensile strength in the MD direction (flow direction) of the resin layer 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. It is. If it is in the said range, it will become possible to suppress the deflection amount of an adhesive sheet, and will become a preferable aspect.

  In the technology disclosed herein, the resin material constituting the resin layer (support / base material) can be used without any particular limitation. For example, transparency, mechanical strength, thermal stability, and moisture shielding properties can be used. It is preferable to use a material excellent in characteristics such as isotropic property, flexibility, and dimensional stability. In particular, since the resin layer has flexibility, the pressure-sensitive adhesive composition can be applied by a roll coater or the like, and can be wound up into 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; cellulose polymers such as diacetyl cellulose and triacetyl cellulose; polycarbonate polymers; polymethyl methacrylate, and the like. It is preferable to use as the resin layer a plastic film composed of a resin material having an acrylic polymer as a main resin component (a main component of the resin component, typically a component occupying 50% by mass or more). it can. Other examples of the resin material include styrene polymers such as polystyrene and acrylonitrile-styrene copolymers; olefin polymers such as polyethylene, polypropylene, polyolefins having a cyclic or norbornene structure, and ethylene-propylene copolymers; Examples of the resin material include vinyl chloride polymers; amide polymers such as nylon 6, nylon 6,6, and aromatic polyamide. Still other examples of the resin material include imide polymers, sulfone polymers, polyether sulfone polymers, polyether ether ketone polymers, polyphenylene sulfide polymers, vinyl alcohol polymers, vinylidene chloride polymers, vinyl butyral polymers. , Arylate polymers, polyoxymethylene polymers, epoxy polymers and the like. It may be a resin layer made of a blend of two or more of the polymers described above.

  Further, 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 polyester. A more preferred embodiment is a film. Here, the polyester film is one having 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. Such a polyester film has favorable characteristics as a resin layer of an adhesive sheet (surface protective film), such as excellent optical characteristics and dimensional stability, and has the property of being easily charged as it is. Examples of the resin layer that satisfies the tensile strength include the following resins. Polyester polymers such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate; Cellulose polymers such as diacetyl cellulose and triacetyl cellulose; Polycarbonate polymers; Acrylic polymers such as polymethyl methacrylate; Polystyrene polymers A polyolefin having a cyclic or norbornene structure; an amide-based polymer such as nylon 6, nylon 6,6, aromatic polyamide; etc. The main resin component (the main component of the resin component, typically 50% by mass or more) A plastic film composed of a resin material as an occupying component can be preferably used as the resin layer. It may be a resin layer made of a blend of two or more of the polymers described above.

  Various additives such as an antioxidant, an ultraviolet absorber, a plasticizer, and a colorant (pigment, dye, etc.) may be blended in the resin material constituting the resin layer, if necessary. Further, the surface of the resin layer may be subjected to known or conventional surface treatments such as corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, and application of a primer. Such a surface treatment can be, for example, a treatment for enhancing the adhesion between the resin layer and the pressure-sensitive adhesive layer, the topcoat layer, etc. (such as the anchoring property of the pressure-sensitive adhesive layer). A surface treatment in which polar groups such as hydroxyl groups are introduced on the surface of the resin layer can be preferably employed.

  In addition, the structure (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 refers to a layer obtained by joining the surfaces of adjacent resin layers and integrating them with practically sufficient adhesive force and adhesion time. Examples of the material forming the adhesive layer include a pressure-sensitive adhesive, an adhesive, and an anchor coat agent. The adhesive layer may have a multilayer structure in which an anchor coat layer is formed on the surface of the resin layer and an adhesive layer is formed thereon. The “pressure-sensitive adhesive layer” in the present invention means a peelable (removable) layer.

  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. Hereinafter, it is most preferably 0.30 or less. By setting to such a range, it is possible to very well suppress the warpage of the adherend (for example, an optical member). On the other hand, the value of the thickness ratio is preferably 0.03 or more. By setting to such a range, it is excellent in the flexibility of the obtained adhesive sheet, and can achieve extremely excellent peelability.

  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, the effect of suppressing the warpage of the adherend (for example, an optical member) may be 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, and still more preferably 5 to 20 μm. When the thickness of the adhesive layer is too thick, there is a possibility that a defect (for example, glue chipping) may occur in the formation of the adhesive layer.

According to the pressure-sensitive adhesive sheet of the present invention, stress relaxation can be achieved by providing an adhesive layer, the peel strength of the pressure-sensitive adhesive sheet obtained can be reduced, pickup property can be improved, and pick-up with a lower peel strength than the resin layer alone. It becomes possible to do. Moreover, by having a resin layer film (in order of the first resin layer, the adhesive layer, and the second resin layer) in which the resin layers are laminated via the adhesive layer, the amount of deflection of the laminated film can be determined by the individual resin layers. It is possible to improve (reduce the amount of deflection) from the amount of deflection of the film, improve the problem of conveyance failure due to folding or deformation in the conveyance process, and achieve improvement in manufacturing efficiency. The adhesive layer has a storage elastic 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 1.0 × 10 ^7. It is less than Pa, more preferably 1.0 × 10 ⁵ Pa or more and less than 1.0 × 10 ⁶ Pa. The storage elastic modulus of the adhesive layer is measured under a condition of a frequency of 1 Hz using a dynamic viscoelasticity measuring device.

  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. The crosslinking agent is not particularly limited as long as it is a compound that reacts with a (meth) acrylic polymer, but an isocyanate compound, an epoxy compound, a melamine resin, an aziridine derivative, and a metal chelate compound are preferably used.

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

  The (meth) acrylic polymer is obtained, for example, by homopolymerizing or copolymerizing alkyl (meth) acrylate. The alkyl group of the alkyl (meth) acrylate may be linear, branched or cyclic. The number of carbon atoms of 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, 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, Lil (meth) acrylate, cyclohexyl (meth) acrylate one bets. These are used alone or in combination of two or more.

  The (meth) acrylic polymer is preferably a copolymer of the alkyl (meth) acrylate and a hydroxyl group-containing (meth) acrylate. In this case, the carbon number of 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, 4-hydroxybutyl (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-hydroxymethylcyclohexane Sill) - methyl acrylate. These are used alone or in combination of two or more.

  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 of the hydroxyalkyl group of the hydroxyl group-containing (meth) acrylate is preferably 1-8, more preferably 2-4, and even more preferably 2. Thus, by adjusting the carbon number of the alkyl group, the reactivity with an isocyanate 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 mol%, more preferably 0.10 to 8 mol%, still more preferably 0.12 to 3 mol%, and still more preferably. It is 0.14-1.5 mol%, Most preferably, it is 0.14-0.25 mol%.

  The (meth) acrylic polymer can be obtained by copolymerizing other components in addition to the alkyl (meth) acrylate and the hydroxyl group-containing (meth) acrylate. Other components include, but are not limited to, (meth) acrylic acid, benzyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxymethyl (meth) acrylate, phenoxyethyl (meth) acrylate, (meth) acrylamide, acetic acid Vinyl, (meth) acrylonitrile and the like are preferably used. The copolymerization amount of the other components is preferably 100 parts by mass or less, 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 a value measured by a gel permeation chromatograph (GPC) method using a tetrahydrofuran (THF) solvent, preferably 400,000 or more, more preferably 1,000,000. -3 million, particularly preferably 1.2 million to 2.5 million.

  Examples of the isocyanate compound include 2,4- (or 2,6-) tolylene diisocyanate, xylylene diisocyanate, 1,3-bis (isocyanate methyl) cyclohexane, hexamethylene diisocyanate, norbornene diisocyanate, chlorophenylene diisocyanate, tetramethylene. Isocyanate monomers such as diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, trimethylolpropane xylene diisocyanate, hydrogenated diphenylmethane diisocyanate; adduct isocyanate compounds obtained by adding these isocyanate monomers to polyhydric alcohols such as trimethylolpropane; isocyanurate compounds; burettes Type compound; furthermore any suitable polyether polyol All or a polyester polyol, acrylic polyol, polybutadiene polyol, polyisoprene polyol urethane prepolymer type obtained by addition reaction of such isocyanates and the like, which may be used alone or in combination of two or more.

  A commercial item can be used as it is as the isocyanate compound. Examples of commercially available isocyanate compounds include Takenate series (trade name “D-110N, 500, 600, 700”, etc.) manufactured by Mitsui Takeda Chemical Co., Ltd., and Coronate series (manufactured by Nippon Polyurethane Industry Co., Ltd.). For example, trade names “L, MR, EH, HL”, etc.) may be mentioned.

  Examples of the epoxy compound include N, N, N ′, N′-tetraglycidyl-m-xylenediamine (trade name: TETRAD-X, manufactured by Mitsubishi Gas Chemical Company) and 1,3-bis (N, N-dioxy). Glycidylaminomethyl) cyclohexane (trade name: TETRAD-C, manufactured by Mitsubishi Gas Chemical Company, Inc.).

  Examples of the melamine resin include hexamethylol melamine. Examples of the aziridine derivative include commercially available product names HDU, TAZM, TAZO (manufactured by Mutual Yakugyo Co., Ltd.) and the like.

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

  The content of the crosslinking agent used in the present invention is, for example, preferably 0.1 to 10 parts by mass, and 0.2 to 4 parts by mass with respect to 100 parts by mass of the (meth) acrylic polymer. It is more preferably contained, still more preferably 0.3 to 1.5 parts by mass, and most preferably 0.4 to 0.9 parts by mass. By setting it as such content, adhesiveness can become favorable also in a severe (high temperature, high humidity) environment. These crosslinking agents may be used alone or in combination of two or more.

  The acrylic adhesive (adhesive composition) preferably further contains a silane coupling agent and a radiation curable component. As the silane coupling agent, for example, one having any appropriate functional group can be selected. Examples of the functional group include vinyl group, epoxy group, methacryloxy group, amino group, mercapto group, acryloxy group, acetoacetyl group, isocyanate group, styryl group, polysulfide group and the like. Specific examples of the silane coupling agent include vinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, and γ-methacryloxypropyltrimethoxy. Silane, γ-acryloxypropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, γ-aminopropylmethoxysilane, γ-mercaptopropylmethyldimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide , Γ-isocyanatopropyltrimethoxysilane and the like. Among these, Preferably, it is a silane coupling agent which has an epoxy group, More preferably, it is (gamma) -gridoxypropyl trimethoxysilane.

  A commercial item can be used as it is as the silane coupling agent. Commercially available products include, for example, KA series (trade name “KA-1003”, etc.), KBM series (trade names “KBM-303, KBM-403, KBM-503”, etc.) and KBE series manufactured by Shin-Etsu Silicone Co., Ltd. (Trade names “KBE-402, KBE-502, KBE-903”, etc.), SH series manufactured by Toray Industries, Inc. (trade names “SH6020, SH6040, SH6062”, etc.) and SZ series (trade names “SZ6030, SZ6032, SZ6300 "etc.).

  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 with respect to 100 parts by mass of the (meth) acrylic polymer. More preferably, it is 0.01-1.0 mass part, Most preferably, it is 0.02-0.5 mass part. By setting it as such content, peeling | exfoliation and bubble generation | occurrence | production can be suppressed also in a severe (high temperature, high humidity) environment.

  As the radiation curable component, a monomer and / or oligomer component that undergoes radical polymerization or cationic polymerization by radiation is used. Examples of the monomer component that undergoes radical polymerization by radiation include monomers having an unsaturated double bond such as a (meth) acryloyl group and a vinyl group, and monomers having a (meth) acryloyl group are particularly preferred because of their excellent reactivity. Used. Specific examples of the monomer component having a (meth) acryloyl group include allyl (meth) acrylate, caprolactone (meth) acrylate, cyclohexyl (meth) acrylate, 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, tri Propylene glycol di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, hydroxypivalic acid neopentyl glycol di (meth) acrylate, Methylolpropane tri (meth) acrylate, trimethylolpropane ethoxytri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetradipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol Examples include hexa (meth) acrylate and caprolactone-modified dipentaerythritol hexa (meth) acrylate.

  As an oligomer component that undergoes radical polymerization by radiation, a polyester in which two or more unsaturated double bonds such as a (meth) acryloyl group and a vinyl group are added to a skeleton such as polyester, epoxy, and urethane as a functional group similar to the monomer component ( A (meth) acrylate, an epoxy (meth) acrylate, a urethane (meth) acrylate, or the like is used.

  Polyester (meth) acrylate is obtained by reacting (meth) acrylic acid with polyester having a terminal hydroxyl group obtained from polyhydric alcohol and polycarboxylic acid, and specific examples include Aronix M- manufactured by Toagosei Co., Ltd. Examples include 6000, 7000, 8000, and 9000 series polyester acrylates.

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

  Urethane (meth) acrylate is obtained by reacting polyol, isocyanate, and hydroxy (meth) acrylate. Specific examples are Art Resin UN series manufactured by Negami Kogyo Co., Ltd., NK Oligo U Series manufactured by Shin-Nakamura Chemical Co., Ltd. And Urushi acrylate of Purple Light UV series manufactured by Nippon Synthetic Chemical Industry Co., Ltd.

  As the monomer and / or oligomer component for cationic polymerization, a compound having a cationic polymerizable functional group such as an epoxy group, a hydroxyl group, a vinyl ether group, an episulfide, or an ethyleneimine group is used. A compound having the following is used: Examples of the compound having an epoxy group include a glycidyl ether type epoxy resin produced by a reaction between a polyhydric phenol 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, diglycidyl ether of hydrogenated bisphenol A or its alkylene oxide adduct, ethylene glycol diglycidyl ether , Propylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, butanediol diglycidyl ether, hexanediol diglycidyl ether, cyclohexanedimethanol diglycidyl ether, polypropylene glycol diglycidyl ether, trimethylolpropane polyglycidyl ether, pentaerythritol polyglycidyl Ether, sorbitol polyglycidyl ether, Mention may be made of the sol Shinji glycidyl ether, and the like.

  These (meth) acrylic polymers and radiation-curable components are used in appropriate combinations, but if the compatibility (mixability) is poor, it will be difficult to balance the adhesiveness after radiation curing and the storage elastic modulus. Therefore, it is necessary to appropriately select a combination having good compatibility for reasons such as poor light transmission. In particular, in applications where light transmittance is required, the total light transmittance after curing is adjusted to 85% or more (preferably 90% or more) and a haze value of 10 or less (preferably 5 or less). Moreover, although the compounding quantity of a radiation-curable component is suitably adjusted with the storage elastic modulus and adhesiveness after radiation curing, generally 10-200 mass parts with respect to 100 mass parts of adhesive polymers, Preferably 30- It is used at a ratio of 150 parts by mass.

  The amount of the polyfunctional monomer used is appropriately selected depending on the balance with the (meth) acrylic polymer and further depending on the intended use as the pressure-sensitive adhesive sheet. In order to obtain sufficient heat resistance due to the cohesive strength of the acrylic pressure-sensitive adhesive, it is generally preferable to add 0.1 to 30 parts by mass with respect to 100 parts by mass of the (meth) acrylic polymer. Moreover, it is more preferable to mix | blend at 10 mass parts or less with respect to 100 mass parts of (meth) acrylic-type polymers from the point of a softness | flexibility and adhesiveness.

  Examples of radiation include ultraviolet rays, laser rays, and α rays. Examples include β-rays, γ-rays, x-rays, and electron beams. Ultraviolet rays are preferably used from the viewpoints of good controllability and handling, and cost. More preferably, ultraviolet rays having 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 lamp, or a chemical lamp. In addition, when using an ultraviolet-ray as a radiation, a photoinitiator is added to an acrylic adhesive.

  The photopolymerization initiator may be any substance that generates radicals or cations by irradiating ultraviolet rays of an appropriate wavelength that can trigger the polymerization reaction according to the type of radiation-reactive component. Examples of the agent include benzoins such as benzoin, benzoin methyl ether, benzoin ethyl ether, methyl o-benzoylbenzoate-p-benzoin ethyl ether, benzoin isopropyl ether, α-methylbenzoin, benzyldimethyl ketal, trichloroacetophenone, 2,2 -Acetophenones such as diethoxyacetophenone and 1-hydroxycyclohexyl phenyl ketone; propio such as 2-hydroxy-2-methylpropiophenone and 2-hydroxy-4'-isopropyl-2-methylpropiophenone Benones such as enones, benzophenone, methylbenzophenone, p-chlorobenzophenone, p-dimethylaminobenzophenone, thioxanthones such as 2-chlorothioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, bis (2,4,6- Acylphosphine oxides such as trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, (2,4,6-trimethylbenzoyl)-(ethoxy) -phenylphosphine oxide, benzyl, dibenzos Examples include beron and α-acyl oxime ester. Examples of the cationic photopolymerization initiator include onium salts such as aromatic diazonium salts, aromatic iodonium salts, and aromatic sulfonium salts, organometallic complexes such as iron-allene complexes, titanocene complexes, and arylsilanol-aluminum complexes, nitrobenzyl Examples thereof include esters, sulfonic acid derivatives, phosphoric acid esters, sulfonic acid derivatives, phosphoric acid esters, phenol sulfonic acid esters, diazonaphthoquinone, and N-hydroxyimide sulfonate.

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

  It is also possible to use a photoinitiated polymerization aid such as amines in combination. Examples of the photoinitiator include 2-dimethylaminoethyl benzoate, dimethylaminoacetophenone, p-dimethylaminobenzoic acid ethyl ester, p-dimethylaminobenzoic acid isoamyl ester, and the like. Two or more photopolymerization initiation assistants can be used in combination. The polymerization initiation assistant is preferably blended in an amount of 0.05 to 10 parts by mass, more preferably 0.1 to 7 parts by mass with respect to 100 parts by mass of the (meth) acrylic polymer.

<Lamination method of first resin layer and second resin layer>
Any appropriate method can be adopted as a method of laminating the first resin layer and the second resin layer. As a preferred embodiment, a method is adopted in which an adhesive layer is formed on one resin layer, and the other resin layer is laminated on the adhesive layer. Further, any appropriate method can be adopted as a method for forming the adhesive layer. As a specific example, the adhesive layer can be formed by applying the adhesive (adhesive composition solution) to the resin layer and heating. At the time of coating, it is preferable that the polymer concentration of the acrylic adhesive is appropriately adjusted with a solvent (for example, 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 (a configuration 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, and the pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive composition. Can be used without limitation. For example, an acrylic pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, a polyester-based pressure-sensitive adhesive, a synthetic rubber-based pressure-sensitive adhesive, a natural rubber-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, and the like can be used. Agent and / or urethane-based pressure-sensitive adhesive, particularly preferably an acrylic pressure-sensitive 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 has an alkyl group having 1 to 14 carbon atoms as a raw material monomer constituting the acrylic pressure-sensitive adhesive (meta ) Acrylic monomers can be used. As said (meth) acrylic-type monomer, 1 type (s) 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 becomes easy to control the adhesive force to the adherend (protected body) to be low, and light releasability and re-peeling. A pressure-sensitive adhesive sheet excellent in properties can be obtained. In the present invention, the (meth) acrylic polymer refers to an acrylic polymer and / or a methacrylic polymer, and the (meth) acrylate refers to acrylate and / or methacrylate.

  Specific examples of the (meth) acrylic monomer having an alkyl group having 1 to 14 carbon atoms include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, s-butyl (meth) ) Acrylate, t-butyl (meth) acrylate, isobutyl (meth) acrylate, 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 (meth) acrylate, n-tetradecyl (meth) acrylate, etc. It is done.

  Especially, when using the adhesive sheet of this invention as a surface protection film, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl ( Carbons such as (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-dodecyl (meth) acrylate, n-tridecyl (meth) acrylate, n-tetradecyl (meth) acrylate A (meth) acrylic monomer having an alkyl group of 6 to 14 is preferred. In particular, by using a (meth) acrylic monomer having an alkyl group having 6 to 14 carbon atoms, it becomes easy to control the adhesive force to the adherend to be low, and the removability is excellent.

  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, it is 60 mass% or more, More preferably, it is 70 mass% or more, Most preferably, it is 80-93 mass%. If it is less than 50% by mass, the appropriate wettability of the pressure-sensitive adhesive composition and the cohesive strength of the pressure-sensitive adhesive layer will be inferior, 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 said (meth) acrylic-type monomer which has the said hydroxyl group, 1 type (s) or 2 or more types can be used as a main component.

  By using the (meth) acrylic monomer having a hydroxyl group, it is easy to control the crosslinking of the pressure-sensitive adhesive composition, and it is easy to control the balance between the improvement of wettability by flow and the reduction of the adhesive strength in peeling. Become. Furthermore, unlike carboxyl groups and sulfonate groups that can generally act as crosslinking sites, hydroxyl groups have moderate interactions with ionic compounds that are antistatic components (antistatic agents) and organopolysiloxanes having oxyalkylene chains. Therefore, it can be suitably used also in terms of antistatic properties and pickup properties.

  Examples of the (meth) acrylic monomer having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 6-hydroxyhexyl (meth). Acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) methyl acrylate, N-methylol (meth) acrylamide and the like. . In particular, it is preferable to use a (meth) acrylic monomer having a hydroxyl group having 4 or more carbon atoms in the alkyl group, since light release at the time of high-speed peeling is easy.

  It is preferable to contain 15 parts by mass or less of the (meth) acrylic monomer having a hydroxyl group with respect to 100 parts by mass of the (meth) acrylic monomer having an alkyl group having 1 to 14 carbon atoms. Is 1 to 13 parts by mass, more preferably 2 to 11 parts by mass, and most preferably 3.5 to 10 parts by mass. Within the above range, the balance between the wettability of the pressure-sensitive adhesive composition and the cohesive force of the resulting pressure-sensitive adhesive layer can be easily controlled, which is preferable. In particular, by blending 5 parts by mass or more, it becomes easy to obtain an adhesive composition having good creep characteristics.

  In addition, as another polymerizable monomer component, the Tg is 0 ° C. or lower (usually −100 ° C. or higher) for the reason that it is easy to balance the adhesive performance, and the glass transition temperature or peeling of the (meth) acrylic polymer. A polymerizable monomer or the like for adjusting the property can be used as long as the effects of the present invention are not impaired.

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

  Examples of the (meth) acrylic monomer having a carboxyl group include (meth) acrylic acid, carboxylethyl (meth) acrylate, carboxylpentyl (meth) acrylate, 2- (meth) acryloyloxyethyl hexahydrophthalic acid, 2- (meth) acryloyloxypropylhexahydrophthalic acid, 2- (meth) acryloyloxyethyl phthalic acid, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxyethyl maleic acid, Examples thereof include carboxypolycaprolactone mono (meth) acrylate and 2- (meth) acryloyloxyethyl tetrahydrophthalic acid.

  The (meth) acrylic monomer having a carboxyl group is preferably 5 parts by mass or less with respect to 100 parts by mass of the (meth) acrylic monomer having an alkyl group having 1 to 14 carbon atoms. More preferably, it is less than 0.2 parts by mass, more preferably less than 0.2 parts by mass, and most preferably less than 0.01 parts by mass and less than 0.1 parts by mass. In particular, when a (meth) acrylic monomer having a carboxyl group is used in combination with a (meth) acrylic monomer having a hydroxyl group, a pressure-sensitive adhesive composition having excellent creep characteristics can be obtained. There is. When the amount exceeds 5 parts by mass, a large number of acid functional groups such as carboxyl groups having a large interaction exist, and when an ionic compound is blended as an antistatic component, an acid functional group such as a carboxyl group is added to the ionic compound. Interacting with each other hinders ionic conduction, lowers the conduction efficiency, and makes it impossible to obtain sufficient antistatic properties. In particular, when achieving both creep characteristics and light release properties, the hydroxyl group-containing (meth) acrylic monomer is contained in an amount of 5 parts by mass or more, and the carboxyl group-containing (meth) acrylic monomer is 0%. It is preferable that the content be in the range of 0.01 parts by mass or more and less than 0.1 parts by mass because compatibility of characteristics can be achieved.

  Furthermore, the (meth) acrylic monomer having a C1-C14 alkyl group used in the (meth) acrylic polymer, the (meth) acrylic monomer having a hydroxyl group, and the (meth) having a carboxyl group Other polymerizable monomers other than acrylic monomers can be used without particular limitation as long as they do not impair the characteristics of the present invention. For example, cohesive strength / heat resistance improving components 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 In addition, a component having a functional group functioning as an adhesive strength improvement or a crosslinking base point such as a vinyl ether monomer can be appropriately used. 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, vinyl laurate, and the like.

  Examples of the aromatic vinyl monomer include styrene, chlorostyrene, chloromethyl styrene, α-methyl styrene, other substituted styrenes, and the like.

  Examples of amide group-containing monomers include acrylamide, methacrylamide, diethyl acrylamide, N-vinyl pyrrolidone, N, N-dimethyl acrylamide, N, N-dimethyl methacrylamide, N, N-diethyl acrylamide, N, N-diethyl methacryl. Examples include amide, N, N′-methylenebisacrylamide, N, N-dimethylaminopropyl acrylamide, N, N-dimethylaminopropyl methacrylamide, and diacetone acrylamide.

  Examples of the imide group-containing monomer include cyclohexylmaleimide, isopropylmaleimide, N-cyclohexylmaleimide, and itaconimide.

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

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

  Examples of the vinyl ether monomer include methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, and the like.

  In the present invention, 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 as follows: The amount is preferably 0 to 40 parts by mass, more preferably 0 to 30 parts by mass with respect to 100 parts by mass of the (meth) acrylic monomer having an alkyl group having 1 to 14 carbon atoms. By using the other polymerizable monomer within the above range, when an ionic compound is used as an antistatic agent, a good interaction with the ionic compound and a good removability can be appropriately adjusted. .

  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 adhesive force tends to be generated due to the reduced cohesive force of the pressure-sensitive adhesive layer. On the other hand, when the weight average molecular weight exceeds 5,000,000, the fluidity of the polymer is lowered, the wettability to the adherend (for example, polarizing plate) becomes insufficient, and the adherend and the adhesive layer of the adhesive sheet There is a tendency to cause blisters that occur in between. In addition, a weight average molecular weight means what was obtained by measuring by gel permeation chromatography (GPC).

  The glass transition temperature (Tg) of the (meth) acrylic polymer is preferably 0 ° C. or lower, more preferably −10 ° C. or lower (usually −100 ° C. or higher). When the glass transition temperature is higher than 0 ° C., the polymer is difficult to flow, for example, the wettability to the polarizing plate is insufficient, and there is a tendency to cause blisters generated between the polarizing plate and the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet. is there. In particular, when the glass transition temperature is set to −61 ° C. or lower, an adhesive layer excellent in wettability to the polarizing plate and light peelability is easily obtained. In addition, the glass transition temperature of a (meth) acrylic-type polymer can be adjusted in the said range by changing the monomer component and composition ratio to be used suitably.

  The polymerization method of the (meth) acrylic polymer is not particularly limited, and can be polymerized by known methods such as solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization, etc. From the viewpoint of characteristics such as low contamination to the adherend (protected body), solution polymerization is a more preferable embodiment. Further, the polymer obtained may be any of a random copolymer, a block copolymer, an alternating copolymer, a graft copolymer, and the like. In addition, polymerization conditions, a polymerization solvent, a polymerization initiator, 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 appropriate urethane-based pressure-sensitive adhesive can be adopted as the urethane-based pressure-sensitive adhesive. As such a urethane type adhesive, Preferably, what consists of urethane resin obtained by making a polyol and a polyisocyanate compound react is mentioned. Examples of the polyol include polyether polyol, polyester polyol, polycarbonate polyol, and polycaprolactone polyol. Examples of the polyisocyanate compound include diphenylmethane diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, and the like.

<Organopolysiloxane having an oxyalkylene chain>
The pressure-sensitive adhesive layer in the present invention is formed of a pressure-sensitive adhesive composition, and the pressure-sensitive adhesive composition contains an organopolysiloxane having an oxyalkylene chain and contains an organopolysiloxane having an oxyalkylene main chain. It is preferable to do. By using the organopolysiloxane, the surface free energy on the surface of the pressure-sensitive adhesive is reduced, and it is presumed that both low contamination and light release can be achieved even with a small content. In addition, by using the organopolysiloxane, the adhesiveness with the adherend is reduced, so that the pick-up property is improved, and light peeling can be exhibited even in a pressure-sensitive adhesive sheet having a thick resin layer. It becomes.

(式中、Ｒ_１及び／又はＲ_２は、炭素数１〜６のオキシアルキレン鎖を有し、前記オキシアルキレン鎖中のアルキレン基は、直鎖又は分岐していてもよく、前記オキシアルキレン鎖の末端が、アルコキシ基、又は、ヒドロキシル基であってもよい。また、Ｒ_１又はＲ_２のいずれか一方が、ヒドロキシル基でもよく、又は、アルキル基、アルコキシ基であってもよく、前記アルキル基、アルコキシ基の一部が、ヘテロ原子で置換された官能基であってもよい。ｎは、１〜３００の整数である。) As the organopolysiloxane, a known organopolysiloxane having a polyoxyalkylene main chain can be used as appropriate, and is preferably represented by the following formula.

(Wherein R ₁ and / or R ₂ has an oxyalkylene chain having 1 to 6 carbon atoms, and the alkylene group in the oxyalkylene chain may be linear or branched, and the oxyalkylene chain) The terminal of may be an alkoxy group or a hydroxyl group, and either R ₁ or R ₂ may be a hydroxyl group, or may be an alkyl group or an alkoxy group. And a functional group in which a part of the group or alkoxy group is substituted with a hetero atom may be used, and n is an integer of 1 to 300.)

  The organopolysiloxane has a siloxane-containing site (siloxane site) as the main chain and an oxyalkylene chain bonded to the end of the main chain. By using the organopolysiloxane having an oxyalkylene chain, it is presumed that the compatibility with the (meth) acrylic polymer can be balanced and both low contamination and light release can be realized.

Moreover, as said organopolysiloxane in this invention, the following structures can be used, for example. Specifically, R ₁ and / or R ₂ in the formula has an oxyalkylene chain containing a hydrocarbon group having 1 to 6 carbon atoms, and as the oxyalkylene chain, an oxymethylene group, an oxyethylene group, an oxy Examples thereof include a propylene group and an oxybutylene group, and among them, an oxyethylene group and an oxypropylene group are preferable. In addition, when both R ₁ and R ₂ have an oxyalkylene chain, they may be the same or different.

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

  Furthermore, the end of the oxyalkylene chain may be an alkoxy group or a hydroxyl group, but more preferably an alkoxy group. When the separator is bonded to the surface of the adhesive layer for the purpose of protecting the adhesive surface, the organopolysiloxane having a hydroxyl group at the end causes an interaction with the separator, and adhesion (peeling) occurs when the separator is removed from the surface of the adhesive layer. The power may increase.

  N is an integer of 1 to 300, preferably 10 to 200, and more preferably 20 to 150. When n is within the above range, the compatibility with the base polymer is balanced and a preferred embodiment is obtained. Furthermore, you may have reactive substituents, such as a (meth) acryloyl group, an allyl group, and a hydroxyl group, in a molecule | numerator. The organopolysiloxane may be used alone or in combination of two or more.

  Specific examples of the organopolysiloxane having an oxyalkylene chain include, for example, commercially available products having trade names of X-22-4952, X-22-4272, X-22-6266, KF-6004, KF-889. (Shin-Etsu Chemical Co., Ltd.), BY16-201, SF8427 (Toray Dow Corning, Inc.), IM22 (Asahi Kasei Wacker Co., Ltd.) and the like. These compounds may be used alone or in combination of two or more.

(式中、Ｒ_１は１価の有機基、Ｒ_２，Ｒ_３及びＲ_４はアルキレン基、Ｒ_５は水素もしくは有機基、ｍ及びｎは０〜１０００の整数。但し、ｍ, ｎが同時に０となることはない。ａ及びｂは０〜１００の整数。但し、ａ, ｂが同時に０となることはない。) In addition to the organopolysiloxane having (bonding) the oxyalkylene chain in the main chain, it is also possible to use an organopolysiloxane having (bonding) the oxyalkylene chain in the side chain. It is a more preferable embodiment to use an organopolysiloxane having an oxyalkylene chain. As the organopolysiloxane, an organopolysiloxane having a known polyoxyalkylene side chain can be used as appropriate, and is preferably represented by the following formula.

Wherein R ₁ is a monovalent organic group, R ₂ , R ₃ and R ₄ are alkylene groups, R ₅ is hydrogen or an organic group, and m and n are integers from 0 to 1000, provided that m and n are simultaneously (A and b are integers from 0 to 100, provided that a and b are not 0 at the same time.)

Moreover, as said organopolysiloxane in this invention, the following structures can be used, for example. Specifically, R ₁ in the formula is a monovalent group exemplified by an alkyl group such as a methyl group, an ethyl group or a propyl group, an aryl group such as a phenyl group or a tolyl group, or an aralkyl group such as a benzyl group or a phenethyl group. It is an organic group, and each may have a substituent such as a hydroxyl group. R ₂ , R ₃ and R ₄ may be an alkylene group having 1 to 8 carbon atoms such as a methylene group, an ethylene group or a propylene group. Here, R ₃ and R ₄ are different alkylene groups, and R ₂ may be the same as or different from R ₃ or R ₄ . One of R ₃ and R ₄ is an ethylene group in order to increase the concentration of an antistatic component (such as an ionic liquid or an alkali metal salt having a melting point of 100 ° C. or lower) that can be dissolved in the polyoxyalkylene side chain. Or it is preferable that it is a propylene group. R ₅ may be an alkyl group such as a methyl group, an ethyl group or a propyl group, or a monovalent organic group exemplified by an acyl group such as an acetyl group or a propionyl group, each having a substituent such as a hydroxyl group. It may be. These compounds may be used alone or in combination of two or more. Moreover, you may have reactive substituents, such as a (meth) acryloyl group, an allyl group, and a hydroxyl group, in a molecule | numerator. Among the organopolysiloxanes having a polyoxyalkylene side chain, organopolysiloxanes having a polyoxyalkylene side chain having a hydroxyl group terminal are presumed to be easily balanced.

  Specific examples of the organopolysiloxane include, for example, commercial names KF-351A, KF-352A, KF-353, KF-354L, KF-355A, KF-615A, KF-945, KF-640, KF-642, KF-643, KF-6022, X-22-6191, X-22-4515, KF-6004, KF-6011, KF-6012, KF-6015, KF-6017, KF-6020, X- 22-2516 (manufactured by Shin-Etsu Chemical Co., Ltd.) SF8428, FZ-2162, SH3749, FZ-77, L-7001, FZ-2104, FZ-2110, L-7002, FZ-2122, FZ-2164, FZ- 2203, FZ-7001, SH8400, SH8700, SF8410, SF8422 (above, Toray Dow Corning), TSF-4440, TSF-4441, TSF-4445, TSF-4450, TSF-4446, TSF-4442, TSF-4460 (manufactured by Momentive Performance Materials), BYK-333, BYK-307, BYK-377, BYK-UV3500, BYK-UV3570 (manufactured by Big Chemie Japan) and the like can be mentioned. These compounds may be used alone or in combination of two or more.

  The organopolysiloxane used in the present invention preferably has an HLB (Hydrophile-Lipophile Balance) value of 1 to 16, more preferably 3 to 14. When the HLB value is out of the above range, the contamination of the adherend is deteriorated, which is not preferable.

  Moreover, 0.01-5 mass parts is preferable with respect to 100 mass parts of said (meth) acrylic-type polymers, More preferably, it is 0.07-3 mass parts, More preferably. Is 0.05 to 1 part by mass. It is preferable for it to be in the above-mentioned range since both antistatic properties and light releasability (removability) can be easily achieved.

<Antistatic component in adhesive layer>
In the pressure-sensitive adhesive sheet of the present invention, the pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer may contain an antistatic component. It is more preferable to contain 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 lower. By containing these ionic compounds, excellent antistatic properties can be imparted. The pressure-sensitive adhesive layer (using the antistatic component) obtained by crosslinking the pressure-sensitive adhesive composition containing the antistatic component as described above is an adherend that is not antistatic when peeled (for example, a polarizing plate) ) Is prevented, and the adhesive sheet is reduced in contamination to the adherend. For this reason, it becomes very useful as an antistatic pressure-sensitive adhesive sheet in a technical field related to optical and electronic components in which charging and contamination are particularly serious problems.

  The content of the antistatic component is preferably 4.9 parts by mass or less, more preferably 0.001 to 0.9 parts by mass, and more preferably 100 parts by mass of the (meth) acrylic polymer. It is 0.005-0.8 mass part, Most preferably, it is 0.01-0.5 mass part. It is preferable for it to be in the above-mentioned range since it is easy to achieve both antistatic properties and low contamination.

<Crosslinking agent>
In the pressure-sensitive adhesive sheet of the present invention, the pressure-sensitive adhesive composition preferably 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, the structural unit, the structural ratio, the selection and addition ratio of the crosslinking agent, etc. of the (meth) acrylic polymer are appropriately adjusted for crosslinking. A pressure-sensitive adhesive sheet (pressure-sensitive adhesive layer) having better heat resistance 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. In particular, the use of an isocyanate compound is a preferred embodiment. Moreover, these compounds may be used independently and may be used in mixture of 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), dimer diisocyanate, cyclopentylene diisocyanate, cyclohexylene diisocyanate, and isophorone diisocyanate. (IPDI) and other alicyclic isocyanates, 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate (XDI) and other aromatic isocyanates, and the isocyanate compounds are allophanate bonds, biuret bonds, Isocyanurate bond, uretdione bond, urea bond, carbodiimide bond, uretonimine bond, oxy Polyisocynate modified product obtained by modifying the like trione bond. For example, as commercial products, the product names Takenate 300S, Takenate 500, Takenate D165N, Takenate D178N (above, Takeda Pharmaceutical Co., Ltd.), Sumijoule T80, Sumijoule L, Death Module N3400 (above, Sumika Bayer Urethane Co., Ltd.) Millionate MR, Millionate MT, Coronate L, Coronate HL, Coronate HX (above, manufactured by Nippon Polyurethane Industry Co., Ltd.) and the like. These isocyanate compounds may be used alone, or may be used in combination of two or more, and a bifunctional isocyanate compound and a trifunctional or higher isocyanate compound may be used in combination. By using a cross-linking agent in combination, it is possible to achieve both stable tackiness and repulsion resistance (adhesiveness to a curved surface), and a pressure-sensitive adhesive sheet with better adhesion reliability can be obtained.

  When a bifunctional isocyanate compound and a trifunctional or higher functional isocyanate compound are used in combination as the isocyanate compound, the blending ratio (mass ratio) of both compounds is [bifunctional isocyanate compound] / [3 It is preferable that the functional compound or higher isocyanate compound] (mass ratio) is 0.1 / 99.9 to 50/50, more preferably 0.1 / 99.9 to 20/80, and 0.1 / 99. Is more preferably from 0.1 / 99.9 to 5/95, and most preferably from 0.1 / 99.9 to 1/99. By adjusting and blending within the above range, a pressure-sensitive adhesive layer having excellent adhesiveness and repulsion resistance is obtained, which is a preferred embodiment.

  Examples of the epoxy compound include N, N, N ′, N′-tetraglycidyl-m-xylenediamine (trade name: TETRAD-X, manufactured by Mitsubishi Gas Chemical Company) and 1,3-bis (N, N-dioxy). Glycidylaminomethyl) cyclohexane (trade name: TETRAD-C, manufactured by Mitsubishi Gas Chemical Company, Inc.).

  Examples of the melamine resin include hexamethylol melamine. Examples of the aziridine derivative include commercially available product names HDU, TAZM, TAZO (manufactured by Mutual Yakugyo Co., Ltd.) and the like.

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

  The content of the crosslinking agent used in the present invention is, for example, preferably 0.01 to 10 parts by mass, and 0.1 to 8 parts by mass with respect to 100 parts by mass of the (meth) acrylic polymer. It is more preferably contained, more preferably 0.5 to 5 parts by mass, and most preferably 1 to 4 parts by mass. When the content is less than 0.01 parts by mass, the crosslinking formation by the crosslinking agent becomes insufficient, the cohesive force of the resulting pressure-sensitive adhesive layer becomes small, and sufficient heat resistance may not be obtained, It tends to cause glue residue. On the other hand, when the content exceeds 10 parts by mass, the cohesive force of the polymer is large, the fluidity is lowered, the wettability to the adherend (for example, polarizing plate) becomes insufficient, and the adherend and the pressure-sensitive adhesive. There is a tendency to cause blisters generated between the layer (adhesive composition layer). Furthermore, when the amount of the crosslinking agent is large, the peeling charging property tends to be lowered. These crosslinking agents may be used alone or in combination of two or more.

  The pressure-sensitive adhesive composition may further contain a cross-linking catalyst for causing any of the above-described cross-linking reactions to proceed more effectively. Examples of such crosslinking catalysts include tin catalysts such as dibutyltin dilaurate and dioctyltin dilaurate, tris (acetylacetonato) iron, tris (hexane-2,4-dionato) iron, and 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 (tridecan-6,8-dionato) iron, tris (1-phenylbutane-1,3) Diato) iron, tris (hexafluoroacetylacetonato) iron, tris (ethyl acetoacetate) iron, tris (acetoacetate-n-propyl) iron, tris (isopropyl acetoacetate) iron, tris (acetoacetate-n-butyl) Iron, tris (acetoacetate-sec-butyl) iron, tris (acetoacetate-tert-butyl) iron, tris (methyl propionylacetate) iron, tris (ethyl propionylacetate) iron, tris (propionylacetate-n-propyl) iron , Tris (propionyl acetate-isopropyl) iron, tris (propionyl acetate-n-butyl) iron, tris (propionyl acetate-sec-butyl) iron, tris (propionyl acetate-tert-butyl) iron, tris (benzyl acetoacetate) iron, Tris (dimethyl malonate) iron, tris (diethyl malonate) iron, trimethoxy iron, Iron-based catalysts such as triethoxy iron, triisopropoxy iron, and ferric chloride can be used. These crosslinking catalysts may be used alone or in combination of two or more.

  The content (use amount) of the crosslinking catalyst is not particularly limited, but is preferably about 0.0001 to 1 part by mass with respect to 100 parts by mass of the (meth) acrylic polymer, for example, 0.001 -0.5 mass part is more preferable. Within the above range, when the pressure-sensitive adhesive layer is formed, the speed of the cross-linking reaction is high, and the pot life of the pressure-sensitive adhesive composition is lengthened.

  Furthermore, the pressure-sensitive adhesive composition may contain other known additives, such as powders such as colorants and pigments, surfactants, plasticizers, tackifiers, low molecular weight polymers, Surface lubricants, leveling agents, antioxidants, corrosion inhibitors, light stabilizers, UV absorbers, polymerization inhibitors, silane coupling agents, inorganic or organic fillers, metal powders, particles, foils, etc. Can be added as appropriate according to the intended use.

  The pressure-sensitive adhesive sheet of the present invention is formed by forming the pressure-sensitive adhesive layer on the second resin layer, and in that case, the crosslinking of the pressure-sensitive adhesive composition is generally performed after application of the pressure-sensitive adhesive composition. It is also possible to transfer the pressure-sensitive adhesive layer made of the pressure-sensitive adhesive composition after crosslinking to a resin layer or the like.

  Further, the method for forming the pressure-sensitive adhesive layer on the second resin layer is not particularly limited. 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 remove the pressure-sensitive adhesive layer. Is formed on the resin layer. Thereafter, curing may be performed for the purpose of adjusting the component transfer of the pressure-sensitive adhesive layer or adjusting the crosslinking reaction. In addition, when the pressure-sensitive adhesive composition is applied on the resin layer to produce a pressure-sensitive adhesive sheet, one or more solvents other than the polymerization solvent are newly added to the pressure-sensitive adhesive composition so that the pressure-sensitive adhesive composition can be uniformly applied on the resin layer. You may add to.

  Moreover, as a formation method of the adhesive layer at the time of manufacturing the adhesive sheet of this invention, the well-known method used for manufacture of adhesive tapes is used. Specific examples include roll coating, gravure coating, reverse coating, roll brushing, spray coating, air knife coating, extrusion coating using a die coater, and the like.

  Usually, the pressure-sensitive adhesive layer is prepared to have a thickness of 3 to 100 μm, and preferably about 5 to 50 μm. It is preferable for the thickness of the pressure-sensitive adhesive layer to be within the above-mentioned range, since it is easy to obtain a suitable balance between removability and adhesion (adhesion).

<Separator>
In the pressure-sensitive adhesive sheet of the present invention, a separator can be bonded to the surface of the pressure-sensitive adhesive layer for the purpose of protecting the pressure-sensitive adhesive surface as necessary.

  Examples of the material constituting the separator include paper and plastic film, and a plastic film is preferably used from the viewpoint of excellent surface smoothness. The film is not particularly limited as long as it can protect the pressure-sensitive adhesive layer. For example, polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer Examples thereof include a coalesced film, a polyethylene terephthalate film, a polybutylene terephthalate film, a polyurethane film, and an ethylene-vinyl acetate copolymer film.

  The thickness of the separator is usually about 5 to 200 μm, preferably about 10 to 100 μm. It is preferable for it to be in the above-mentioned range since it is excellent in workability for bonding to the pressure-sensitive adhesive layer and workability for peeling from the pressure-sensitive adhesive layer. For the separator, if necessary, mold release and antifouling treatment with a silicone type, fluorine type, long chain alkyl type or fatty acid amide type release agent, silica powder, etc., coating type, kneading type, vapor deposition type It is also possible to carry out antistatic treatment such as.

<Topcoat 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 from the pressure-sensitive adhesive composition in this order. The resin layer has a topcoat layer on the surface opposite to the surface having the pressure-sensitive adhesive layer, and the topcoat layer comprises a polyaniline sulfonic acid as a conductive polymer component, a polyester resin as a binder component, and a crosslinking agent. It is formed from the composition for topcoat layers containing an isocyanate type compound. When the pressure-sensitive adhesive sheet has a topcoat layer, the antistatic property of the pressure-sensitive adhesive sheet is improved, which is a preferred embodiment.

<Conductive polymer>
The top coat layer contains polyaniline sulfonic acid as a conductive polymer component. By using the conductive polymer, the antistatic property based on the topcoat layer and the antistatic property with time can be satisfied. The polyaniline sulfonic acid is “water-soluble” but can be immobilized in the topcoat layer by using an isocyanate-based cross-linking agent described later, and water resistance can be improved. By using the water-soluble conductive polymer-containing aqueous solution, a top coat layer having excellent surface resistivity over time is obtained, which is a preferred embodiment. On the other hand, when the conductive polymer used for forming the topcoat layer is “water-dispersible”, aggregates are generated when the topcoat layer is formed using the water-dispersible conductive polymer-containing solution. This is not preferable because it tends to be easy and cannot be applied uniformly, and the surface resistivity with time tends to be extremely inferior.

  The amount of the conductive polymer used is preferably 10 to 200 parts by mass, more preferably 25 to 150 parts by mass, and still more preferably 40 to 120 parts with respect to 100 parts by mass of the binder contained in the topcoat layer. Part by mass. If the amount of the conductive polymer used is too small, the antistatic effect may be reduced. If the amount of the conductive polymer used is too large, the adhesion of the topcoat layer to the resin layer may be reduced or the transparency may be decreased. There is a risk of lowering, which is not preferable.

The polyaniline sulfonic acid used as the conductive polymer component preferably has a polystyrene equivalent weight average molecular weight (Mw) 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 more, and more preferably 5 × 10 ³ or more.

As a method of forming the topcoat layer, a method of applying and drying (or curing) a composition for topcoat layer (coating material for forming a topcoat layer) on the first surface of a resin layer (base material / support). The conductive polymer component used for the preparation of the composition for the topcoat layer can be employed as a polyaniline sulfonic acid, a polyester resin as a binder, and an isocyanate-based crosslinking agent as a crosslinking agent as essential components. The component 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 is prepared by, for example, 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 the molecule) in water. can do. Examples of the hydrophilic functional group include a sulfo group, amino group, amide group, imino group, hydroxyl group, mercapto group, hydrazino group, carboxyl group, quaternary ammonium group, sulfate group (—O—SO ₃ H), phosphorus An acid ester group (for example, —O—PO (OH) ₂ ) and the like are exemplified. Such hydrophilic functional groups may form a salt.

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

  The topcoat layer disclosed herein contains polyaniline sulfonic acid (polyaniline type) as an essential component as a conductive polymer component. For example, one or more other antistatic components (conductive polymer) Organic conductive materials other than the above, inorganic conductive materials, antistatic agents, etc.) may be included together. As a preferred embodiment, the topcoat layer contains substantially no antistatic component other than the conductive polymer, that is, the antistatic component contained in the topcoat layer is substantially only a conductive polymer. The embodiment consisting of can be implemented more preferably.

  Examples of the organic conductive substance include cation type antistatic agents having a cationic functional group such as a quaternary ammonium salt, a pyridinium salt, a primary amino group, a secondary amino group, and a tertiary amino group; sulfonates and sulfates Anionic antistatic agents having an anionic functional group such as salts, phosphonates, phosphate esters; amphoteric ionic antistatic agents such as alkylbetaines and their derivatives, imidazolines and their derivatives, alanine and their derivatives; amino alcohols Nonionic antistatic agents such as glycerin and derivatives thereof, glycerin and derivatives thereof, polyethylene glycol and derivatives thereof; polymerization of monomers having the cation type, anion type or zwitterion type ion conductive groups (for example, quaternary ammonium base) Or an ion conductive polymer obtained by copolymerization; poly Include; thiophene, polyaniline, polypyrrole, polyethylene imine, a conductive polymer such as an allylamine polymer. Such an antistatic agent 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, Examples thereof include copper iodide, ITO (indium oxide / tin oxide), ATO (antimony oxide / tin oxide), and the like. Such inorganic conductive materials may be used alone or in combination of two or more.

  Examples of the antistatic agent include a cationic antistatic agent, an anionic antistatic agent, an amphoteric ion antistatic agent, a nonionic antistatic agent, and a single ion having a cationic, anionic or zwitterionic ion conductive group. Examples thereof include an ion conductive polymer obtained by polymerizing or copolymerizing a monomer.

<Binder>
The top coat layer contains a polyester resin as an essential component as a binder. The polyester resin is preferably a resin material containing polyester as a main component (typically exceeding 50% by mass, preferably 75% by mass or more, for example, 90% by mass or more). The polyester typically includes polyvalent carboxylic acids (typically dicarboxylic acids) having two or more carboxyl groups in one molecule and derivatives thereof (an anhydride, esterified product, halogenated polyvalent carboxylic acid). Selected from one or more compounds (polyhydric carboxylic acid component) selected from, and polyhydric alcohols (typically diols) having two or more hydroxyl groups in one molecule. It is preferable to have a structure in which one or two or more compounds (polyhydric alcohol component) are condensed.

  Examples of compounds that can be employed as the polyvalent 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, methylmaleic acid, fumaric acid, methylfumaric acid, acetylenedicarboxylic acid, glutaric acid, hexafluoroglutaric acid, methylglutaric acid, glutaconic acid, adipic acid, dithioadipic acid, methyladipic acid, dimethyl Adipic acid, tetramethyladipic acid, methyleneadipic acid, muconic acid, galactaric acid, pimelic acid, suberic acid, perfluorosuberic acid, 3,3,6,6-tetramethylsuberic acid, azelaic acid, sebacic acid, perfluoro Sebacic acid, brassic acid, dodecyl dicar Aliphatic dicarboxylic acids such as acid, tridecyl dicarboxylic acid, tetradecyl dicarboxylic acid; cycloalkyl dicarboxylic acid (for example, 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid), 1,4- (2- Alicyclic dicarboxylic acids such as norbornene) dicarboxylic acid, 5-norbornene-2,3-dicarboxylic acid (hymic acid), adamantane dicarboxylic acid, 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, anthracenedical Bonic acid, biphenyl dicarboxylic acid, biphenylene dicarboxylic acid, dimethyl biphenylene dicarboxylic acid, 4,4 "-p-terephenylene dicarboxylic acid, 4,4" -p-quarelphenyl dicarboxylic acid, bibenzyl dicarboxylic acid, azobenzene dicarboxylic acid, Homophthalic acid, phenylenediacetic acid, phenylenedipropionic acid, naphthalenedicarboxylic acid, naphthalenedipropionic acid, biphenyldiacetic acid, biphenyldipropionic acid, 3,3 ′-[4,4 ′-(methylenedi-p-biphenylene) dipropion Aromatic dicarboxylic acids such as acid, 4,4′-bibenzyldiacetic acid, 3,3 ′ (4,4′-bibenzyl) dipropionic acid, oxydi-p-phenylenediacetic acid; Acid anhydrides of any of the polyhydric carboxylic acids mentioned above (Eg alkyl esters). It can be a monoester, a diester or the like. ); Acid halides corresponding to any of the polyvalent carboxylic acids described above (for example, dicarboxylic acid chloride); and the like.

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

  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, and 1,4-butanediol. , Neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 3-methylpentanediol, diethylene glycol, 1,4-cyclohexanedimethanol, 3-methyl-1,5-pentanediol, 2-methyl- Diols such as 1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, xylylene glycol, hydrogenated bisphenol A, and bisphenol A Is mentioned. Other examples include alkylene oxide adducts (for example, ethylene oxide adducts, propylene oxide adducts, etc.) of these compounds.

The molecular weight of the polyester resin is, for example, about 5 × 10 ^{3 to} 1.5 × 10 ⁵ (preferably 1 × 10 5) as a weight average molecular weight (Mw) in terms of standard polystyrene measured by gel permeation chromatography (GPC). ^4-6 × 10 ⁴ ). Moreover, the glass transition temperature (Tg) of the said polyester resin can be 0-120 degreeC (preferably 10-80 degreeC), for example.

  As the polyester resin, a commercially available product name “Vylonal” manufactured by Toyobo Co., Ltd. can be used.

  The topcoat layer is a resin other than a polyester resin (for example, an acrylic resin, an acrylic-urethane resin) as a binder, as long as the performance (for example, performance such as antistatic properties) of the pressure-sensitive adhesive sheet disclosed herein is not significantly impaired. , An acryl-styrene resin, an acryl-silicone resin, a silicone resin, a polysilazane resin, a polyurethane resin, a fluororesin, a polyolefin resin, or the like). A preferred embodiment of the technology disclosed herein is a case where the binder of the topcoat layer is substantially made of only a polyester resin. For example, a top coat layer in which the proportion of the polyester resin in the binder is 98 to 100% by mass is preferable. The proportion of the binder in the entire top coat layer can be set to, for example, 50 to 95% by mass, and normally 60 to 90% by mass is appropriate.

<Lubricant>
The top coat layer in the technology disclosed herein is preferably a fatty acid amide as a lubricant. By using a fatty acid amide as a lubricant, a further release treatment (for example, a treatment in which a known release treatment agent such as a silicone release agent or a long-chain alkyl release agent is applied and dried) is applied to the surface of the topcoat layer. Even in the case where the coating is not performed, a top coat layer having both sufficient slipping property and printing adhesion can be obtained, so that it can be a preferable mode. Thus, the aspect in which the surface of the topcoat layer is not subjected to further peeling treatment can prevent whitening caused by the peeling treatment agent (for example, whitening due to storage under heating and humidification conditions). This is preferable. It is also advantageous from the viewpoint of solvent resistance.

  Specific examples of the fatty acid amide include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, hydroxystearic acid amide, oleic acid amide, erucic acid amide, N-oleylparticic acid amide, N-stearyl stearic acid. Amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl erucic acid amide, methylol stearic acid amide, methylene bis stearic acid amide, ethylene biscapric acid amide, ethylene bis lauric acid amide, ethylene bis stearic acid Amides, ethylene bishydroxystearic acid amides, ethylene bisbehenic acid amides, hexamethylene bisstearic acid amides, hexamethylene bisbehenic acid amides, hexamethylene hydroxystearic acid amides N, N′-distearyl adipic acid amide, N, N′-distearyl sebacic acid amide, ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bisoleic acid amide, N, N′-dioleyl Examples include adipic acid amide, N, N′-dioleyl sebacic acid amide, m-xylylene bisstearic acid amide, m-xylylene bishydroxystearic acid amide, N, N′-stearyl isophthalic acid amide, and the like. These lubricants may be used alone or in combination of two or more.

  The ratio of the lubricant to the whole top coat layer can be 1 to 50% by mass, and usually 5 to 40% by mass is appropriate. When there is too little content rate of a lubricant, it exists in the tendency for slipperiness to fall easily. If the content of the lubricant is too large, the print adhesion may be lowered.

  The technique disclosed here can be implemented in a mode in which the top coat layer contains other lubricants in addition to the fatty acid amide, as long as the application effect is not significantly impaired. Examples of such other lubricants include various waxes such as petroleum wax (paraffin wax and the like), mineral wax (montan wax and the like), higher fatty acid (cellotic acid and the like), and neutral fat (palmitic acid triglyceride and the like). It is done. Alternatively, in addition to the wax, a general silicone-based lubricant, a fluorine-based lubricant, and the like may be supplemented. The technology disclosed herein can be preferably implemented in an embodiment that does not substantially contain such a silicone-based lubricant, a fluorine-based lubricant and the like. However, as long as the application effect of the technology disclosed herein is not significantly impaired, the content of the silicone compound used for a purpose other than the lubricant (for example, as an antifoaming agent for the composition for the topcoat layer described later) is included. It is not excluded.

<Crosslinking agent>
The topcoat layer contains an isocyanate-based crosslinking agent as a crosslinking agent. By using the isocyanate-based crosslinking agent, water-soluble polyaniline sulfonic acid, which is an essential component when forming the topcoat layer, can be fixed in the binder, excellent in water resistance, and further improved in print adhesion, etc. The effect can be realized.

  In addition, 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. Specific examples of the blocked isocyanate crosslinking agent include isocyanate crosslinking agents that can be used in the preparation of general pressure-sensitive adhesive layers and topcoat layers (for example, isocyanate compounds used in pressure-sensitive adhesive layers described later (isocyanate)). Cross-linking agents)) with alcohols, phenols, thiophenols, amines, imides, oximes, lactams, active methylene compounds, mercaptans, imines, ureas, diaryl compounds, and bisulfite Those blocked with soda can be used.

  The topcoat layer in the technology disclosed herein includes an antioxidant, a colorant (pigment, dye, etc.), a fluidity modifier (thixotropic agent, thickener, etc.), a film-forming aid, an interface as necessary. It may contain additives such as activators (antifoaming agents, etc.), preservatives, ultraviolet absorbers, dispersants, antiblocking agents and the like.

<Formation of topcoat layer>
The top coat layer is a resin layer obtained by dissolving a liquid composition (composition for a top coat layer) in which an essential component such as the conductive polymer component and an additive used as necessary are dissolved in an appropriate solvent (such as water). It can be suitably formed by a technique including applying to. For example, a method of applying the top coat layer composition to the first surface of the resin layer and drying it, and performing a curing treatment (heat treatment, ultraviolet treatment, etc.) as necessary can be preferably employed. The NV (nonvolatile content) of the composition for the top coat 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. When forming a thin topcoat layer, the NV of the composition for topcoat layer is preferably 0.05 to 0.50% by mass (for example, 0.10 to 0.40% by mass). . Thus, a more uniform topcoat layer can be formed by using the composition for a topcoat layer having a low NV.

  As the solvent constituting the composition for topcoat layer (coating material for forming the topcoat layer), a solvent capable of stably dissolving the components for forming the topcoat layer is preferable. Such a solvent may be an organic solvent, water, or a mixed solvent thereof. Examples of the organic solvent include esters such as ethyl acetate; ketones such as methyl ethyl ketone, acetone and cyclohexanone; cyclic ethers such as tetrahydrofuran (THF) and dioxane; aliphatic or alicyclic such as n-hexane and cyclohexane. Hydrocarbons; aromatic hydrocarbons such as toluene and xylene; aliphatic or alicyclic alcohols such as methanol, ethanol, n-propanol, isopropanol, and cyclohexanol; alkylene glycol monoalkyl ether (for example, ethylene glycol monomethyl ether) , Ethylene glycol monoethyl ether), glycol ethers such as dialkylene glycol monoalkyl ether; and the like can be used. In a preferred embodiment, the solvent of the topcoat 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 coat layer>
The thickness of the topcoat 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 topcoat layer is too small, it is difficult to form the topcoat layer uniformly (for example, the thickness of the topcoat layer varies greatly depending on the location). Unevenness can easily occur. On the other hand, if it is too thick, the characteristics (optical characteristics, dimensional stability, etc.) of the resin layer may be affected.

In a preferred embodiment of the pressure-sensitive adhesive sheet disclosed herein, the surface resistivity (Ω / □) measured on the surface of the topcoat layer is preferably less than 1.0 × 10 ¹¹ , more preferably It is less than 5.0 × 10 ¹⁰ , more preferably less than 1.5 × 10 ¹⁰ . The 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 processing or transporting of articles that dislike static electricity such as liquid crystal cells and semiconductor devices. The surface resistivity can be calculated from the surface resistivity measured under an atmosphere of 23 ° C. and 50% RH using a commercially available insulation resistance measuring device.

  The pressure-sensitive adhesive sheet disclosed herein preferably has a property that the back surface (the surface of the topcoat layer) can be easily printed with water-based ink or oil-based ink (for example, using an oil-based marking pen). In such a pressure-sensitive adhesive sheet, the identification number and the like of the adherend to be protected are described in the pressure-sensitive adhesive sheet in the process of processing or transporting the adherend (for example, an optical component) performed with the pressure-sensitive adhesive sheet attached. Suitable for display. Therefore, it is preferable that it is an adhesive sheet excellent in printability. For example, it is preferable that the solvent is alcohol-based and has high printability for oil-based inks containing pigments. Moreover, it is preferable that the printed ink is difficult to be removed by rubbing or transfer (that is, excellent in print adhesion). The pressure-sensitive adhesive sheet disclosed herein preferably has a solvent resistance that does not cause a noticeable change in appearance even if the print is wiped with alcohol (for example, ethyl alcohol) when the print is corrected or erased. .

  The pressure-sensitive adhesive sheet disclosed herein can be implemented in an embodiment including other layers in addition to the resin layer, the adhesive layer, the pressure-sensitive adhesive layer, and the topcoat layer. Such “other layers” are arranged between the first surface (back surface) of the first resin layer and the topcoat layer and between the second surface (front surface) of the second resin layer and the adhesive layer. Etc. are exemplified. The layer disposed between the back surface of the first resin layer and the top coat layer can be, for example, a layer containing an antistatic component (the above-described top coat layer). The layer disposed between the front surface of the second resin layer and the pressure-sensitive adhesive layer can be, for example, an undercoat layer (anchor layer) or a topcoat layer that improves the anchoring property of the pressure-sensitive adhesive layer with respect to the second surface. . The pressure-sensitive adhesive sheet may be configured such that a topcoat layer is disposed on the front surface of the second resin layer, an anchor layer is disposed on the topcoat layer, and a pressure-sensitive adhesive layer is disposed thereon.

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

  Moreover, it is preferable that the total thickness of the adhesive sheet of this invention is 14-400 micrometers, It is more preferable that it is 40-200 micrometers, It is most preferable that it is 55-100 micrometers. Within the above range, the adhesive properties (removability, adhesiveness, etc.), workability, and appearance properties are excellent and a preferred embodiment is obtained. In addition, the said total thickness means the sum total of the thickness including all layers, such as a resin layer, an adhesive layer, an adhesive layer, and a topcoat layer.

  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 the specific examples. In the following description, “part” and “%” are based on mass unless otherwise specified.

  Each characteristic in the following description was measured or evaluated as follows.

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

Sample concentration: 0.2% by mass (THF solution)
Sample injection volume: 10 μl
Eluent: THF
Flow rate: 0.6 ml / min
Measurement temperature: 40 ° C
column:
Sample column; TSKguardcolumn SuperHZ-H (1) + TSKgel SuperHZM-H (2)
Reference column; TSKgel SuperH-RC (1)
Detector: Differential refractometer (RI)
The weight average molecular weight was determined in terms of polystyrene.

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

Formula: 1 / (Tg + 273) = Σ [Wn / (Tgn + 273)]
[Wherein, Tg (° C.) is the glass transition temperature of the copolymer, Wn (−) is the weight fraction of each monomer, Tgn (° C.) is the glass transition temperature of the homopolymer of each monomer, and n is the type of each monomer Represents. ]
Literature values:
2-ethylhexyl acrylate (2EHA): -70 ° C
n-butyl acrylate (BA): -55 ° C
2-Hydroxyethyl acrylate (HEA): -15 ° C
Acrylic acid (AA): 106 ° C

  As reference values, “Synthesis / design of acrylic resin and development of new applications” (published by Central Management Development Center Publishing Department), “Polymer Handbook” (John Wiley & Sons), and monomer manufacturer maker's Kadalog values were referred to.

Moreover, about the glass transition temperature (Tg) (degreeC) of the (meth) acrylic-type polymer obtained with the monomer whose document value is unknown, it determined by the dynamic viscoelasticity measurement in the following procedure.
First, a (meth) acrylic polymer sheet having a thickness of 20 μm is laminated to a thickness of about 2 mm, punched to φ7.9 mm, a cylindrical pellet is prepared, and a glass transition temperature (Tg) measurement sample is obtained. did.
Using the above measurement sample, the measurement sample is fixed to a jig having a φ7.9 mm parallel plate, and the temperature dependence of the loss elastic modulus G ″ is measured by a dynamic viscoelasticity measuring device (ARES, manufactured by Rheometrics). The temperature at which the obtained G ″ curve was maximized was measured as the glass transition temperature (Tg) (° C.). The measurement conditions are as follows.
Measurement: Shear mode Temperature range: -70 ° C to 150 ° C
Temperature increase range: 5 ° C / min
Frequency: 1Hz

<Thickness measurement>
Measurement was performed using a digital micrometer (manufactured by Anritsu, product name “KC-351C”).

<Tensile strength of resin layer>
In accordance with JIS C 2318, measurement was performed using a tensile tester (manufactured by Shimadzu Corporation, product name “Autograph”).

<Storage elastic modulus of adhesive layer>
The adhesive layer was laminated to a thickness of about 2 mm, and this was punched out to φ7.9 mm to produce a cylindrical pellet to obtain a measurement sample. Using the above measurement sample, the measurement sample is fixed to a jig of φ7.9 mm parallel plate, and the storage elastic modulus G ′ at 23 ° C. is measured by a dynamic viscoelasticity measuring device (ARES, manufactured by Rheometrics). did. The measurement conditions are as follows.
Measurement: Shear mode Frequency: 1Hz
The storage elastic modulus (23 ° C.) of the adhesive layer in the present invention is 1.0 × 10 ⁴ Pa or more and less than 5.0 × 10 ⁷ Pa, and preferably 1.0 × 10 ⁴ Pa or more and 1.0 ×. It is less than 10 ⁷ Pa, and more preferably 1.0 × 10 ⁵ Pa or more and less than 1.0 × 10 ⁶ Pa. When it is in the above range, the pickup property of the pressure-sensitive adhesive sheet becomes good, which is a preferred embodiment.

<Measurement of surface resistivity>
Measurement was performed in accordance with JIS-K-6911 using a resistivity meter (manufactured by Mitsubishi Chemical Analytic, Hiresta UP MCP-HT450 type) in an atmosphere of temperature 23 ° C. and humidity 50% RH.
The surface resistivity (Ω / □) in the present invention is preferably 1.0 × both at the initial stage and at room temperature (RT) (23 ° C. × 50% RH) × 1 week (7 days). It is less than 10 ¹¹ , more preferably less than 5.0 × 10 ¹⁰ , and even more preferably less than 1.5 × 10 ¹⁰ . The 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 processing or transporting of articles that dislike static electricity such as liquid crystal cells and semiconductor devices.

<Measurement of peeling voltage (polarizing plate side)>
After the adhesive sheet 1 according to each example was cut to a size of 70 mm in width and 130 mm in length and the release liner was peeled off, as shown in FIG. 2, the acrylic plate 3 (Mitsubishi Rayon Co., Ltd. Adhesive to the surface of polarizing plate 2 (manufactured by Nitto Denko Corporation, SEG1423DU polarizing plate, width: 70 mm, length: 100 mm) bonded to the name “acrylite”, thickness: 1 mm, width: 70 mm, length: 100 mm) The sheet 1 was crimped by a hand roller so that one end of the sheet 1 protruded 30 mm from the end of the polarizing plate 2.
This sample was left in an environment of 23 ° C. × 50% RH for one day, and then set at a predetermined position on a sample fixing base 4 having a height of 20 mm. The end of the pressure-sensitive adhesive sheet 1 protruding 30 mm from the polarizing plate 2 was fixed to an automatic winder (not shown) and peeled so that the peeling angle was 150 ° and the peeling speed was 10 m / min. The potential measuring device 5 (model “KSD-0103” manufactured by Kasuga Denki Co., Ltd.) in which the potential of the adherend (polarizing plate) surface generated at this time is fixed at a height of 100 mm from the center of the polarizing plate 2. The “initial polarizing plate stripping voltage” was measured. The measurement was performed in an environment of 23 ° C. and 50% RH.
The peeling voltage (kV) (absolute value) in the present invention is preferably 1 or less, more preferably 0.9 or less, and still more preferably 0.5 or less. Within the above range, for example, damage to a liquid crystal driver or the like can be prevented, which is a preferable mode.

<Measurement of adhesive strength on back (A)>
As shown in FIG. 3, the pressure-sensitive adhesive sheet 1 according to each example is cut into a size of 70 mm in width and 100 mm in length, and the pressure-sensitive adhesive surface (side on which the pressure-sensitive adhesive layer 20 is provided) 20 </ b> A of the pressure-sensitive adhesive sheet 1 is The tape 130 was used to fix it on the SUS304 stainless steel plate 132. Single-sided pressure-sensitive adhesive tape (made by Nitto Denko Corporation, trade name “No. 31B”, width 19 mm) having an acrylic adhesive 162 on a resin layer film (in order of the first resin layer, the adhesive layer, and the second resin layer) 164 ) 160 was cut to a length of 100 mm. The pressure-sensitive adhesive surface 162A of the pressure-sensitive adhesive tape 160 was pressure-bonded to the back surface (that is, the surface of the topcoat layer 14) 1A of the pressure-sensitive adhesive sheet 1 at a pressure of 0.25 MPa and a speed of 0.3 m / min. This was left under conditions of 23 ° C. and 50% RH for 30 minutes. Thereafter, the pressure-sensitive adhesive tape 160 is peeled from the back surface 1A of the pressure-sensitive adhesive sheet 1 using a universal tensile testing machine under the conditions of a peeling speed of 0.3 m / min and a peeling angle of 180 degrees, and the adhesive strength (A) [N / 19 mm] was measured.

  The back surface adhesive strength (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 0.0 N / 19 mm or more. If the adhesive strength is less than 3.0 N / 19 mm, sufficient adhesive strength cannot be obtained, pick-up properties are inferior, and peeling workability of the protective film is deteriorated.

<Measurement of adhesive strength to polarizing plate (B)>
A plain polarizing plate (TAC polarizing plate manufactured by Nitto Denko Corporation, SEG1425DU) having a width of 70 mm and a length of 100 mm was prepared as an adherend. The pressure-sensitive adhesive sheet according to each example was cut into a size of 25 mm in width and 100 mm in length, and the pressure-sensitive adhesive surface was pressure-bonded to the polarizing plate at a pressure of 0.25 MPa and a speed of 0.3 m / min. After leaving this in an environment of 23 ° C. and 50% RH for 30 minutes, using the universal tensile tester in the same environment, the pressure-sensitive adhesive sheet is peeled off from the polarizing plate under the conditions of a peeling speed of 0.3 m / min and a peeling angle of 180 °. Was peeled, and the adhesive force (B) [N / 25 mm] at this time was measured.
The adhesive strength (B) is preferably 2.5 N / 25 mm or less, more preferably 2.0 N / 25 mm or less, still more preferably 1.5 N / 25 mm or less, most preferably 1. 0 N / 25 mm or less. When the adhesive strength exceeds 2.5 N / 25 mm, the peeling workability is inferior, which is not preferable.

<Pickup property>
As shown in FIG. 4, the pressure-sensitive adhesive sheet 1 according to each example is cut into a size of 50 mm in width and 100 mm in length, and the pressure-sensitive adhesive surface (side on which the pressure-sensitive adhesive layer 20 is provided) 20 </ b> A of this pressure-sensitive adhesive sheet 1 is The sheet was pressure-bonded onto a plate (TAC polarizing plate manufactured by Nitto Denko Corporation, SEG1425DU) 50 at a pressure of 0.25 MPa and a speed of 0.3 m / min.
Single-sided adhesive tape 60 (manufactured by Nitto Denko Corporation, trade name “No. 31B”, width 19 mm) was cut into a width of 10 mm and a length of 50 mm. The pressure-sensitive adhesive layer (adhesive surface) 62 of the pressure-sensitive adhesive tape 60 was pressure-bonded by hand onto the center of the back surface of the pressure-sensitive adhesive sheet 1 having a width of 50 mm (that is, the surface of the topcoat layer 14) so that the end portion protruded 30 mm. This was left under conditions of 23 ° C. and 50% RH for 10 seconds. Then, the single-sided adhesive tape 60 was peeled by hand, and the peeling condition (pickup property) of the adhesive sheet 1 was evaluated.
The evaluation criteria were “good” when the pressure-sensitive adhesive sheet was peelable, and “poor” when the pressure-sensitive adhesive sheet could not be peeled off.

<Deflection amount>
As shown in FIG. 5, the pressure-sensitive adhesive sheet 1 according to each example was cut into a size having a width of 20 mm and a length of 150 mm, and the end of the pressure-sensitive adhesive sheet 1 was faced with Nitto Denko Corporation No. The glass plate G was fixed 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 put on the center position, and the height H2 of the center position of the adhesive sheet at that time was measured. The amount of deflection [mm] was determined by the following equation.
Deflection = H1-H2 [mm]
The deflection amount is preferably 30 mm or less, more preferably 25 mm or less, and still more preferably 20 mm or less. If the amount of deflection exceeds 30 mm, the optical member to which the adhesive sheet is bonded becomes easy to bend during the transport process, which is not preferable.

<Evaluation of printability (print adhesion)>
After printing on the surface of the topcoat layer using an X stamper manufactured by Shachihata Co., Ltd. in a measurement environment of 23 ° C. × 50% RH, a cello tape (registered trademark) manufactured by Nichiban Co., Ltd. Next, peeling is performed under conditions of a peeling speed of 30 m / min and a peeling angle of 180 °. Then, the surface after peeling was visually observed, and x (printability failure) when 50% or more of the print area was peeled off, and ○ (good printability) when 50% or more of the print area remained without peeling. ).

  Below, the preparation method of a topcoat layer, an adhesive composition (adhesive solution), and an adhesive sheet (surface protection film) was described.

[Example 1]
<Preparation of resin layer film (first resin layer, adhesive layer, and second resin layer in this order)>
In a reaction vessel equipped with a cooling pipe, a nitrogen introducing pipe, a thermometer and a stirrer, 100 parts by mass of butyl acrylate (BA), 5.0 parts by mass of acrylic acid (AA), and 2-hydroxyethyl acrylate (2HEA) 0.075 parts by mass, 0.3 parts by mass of 2,2′azobisisonitrile, and ethyl acetate were added and reacted at 60 ° C. for 6 hours with stirring under a nitrogen gas stream to obtain a weight average molecular weight of 1630,000 An acrylic polymer solution was obtained. 0.6 parts by mass of an isocyanate-based polyfunctional compound (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name: Coronate L) and a silane coupling agent (Shin-Etsu Chemical Co., Ltd.) with respect to 100 parts by mass of the polymer solid content of this acrylic polymer solution An acrylic adhesive 1 composition solution was prepared by adding 0.08 part by mass, trade name: KBM403).

As the resin layer, the above-mentioned adhesive composition solution was applied onto a polyester resin film (manufactured by Toyobo Co., Ltd., trade name: E5000, thickness: 38 μm, tensile strength: 208 MPa), and heated at 90 ° C. to a thickness of 20 μm. The adhesive layer was formed. The storage modulus of the obtained adhesive layer at 23 ° C. was 1.0 × 10 ⁵ Pa.
Thereafter, a polyester resin film (manufactured by Toyobo Co., Ltd., trade name: E5000, thickness: 38 μm, tensile strength: 208 MPa) was laminated on the adhesive layer to obtain a resin layer film having a thickness of 96 μm.

<Preparation of acrylic adhesive 1 solution>
In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser, 95 parts by mass of 2-ethylhexyl acrylate (2EHA), 5 parts by mass of 2-hydroxyethyl acrylate (HEA), 2 as a polymerization initiator , 2'-azobisisobutyronitrile and 150 parts by mass of ethyl acetate were charged, nitrogen gas was introduced while gently stirring, and the temperature in the flask was kept at around 65 ° C for 6 hours of polymerization. Reaction was performed and the (meth) acrylic-type polymer solution (40 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) is diluted to 20% by mass with ethyl acetate, and an organopolysiloxane having an oxyalkylene chain (Shin-Etsu) as an antistatic agent is added to 500 parts by mass (100 parts by mass of the solid content) of this solution. Product name: KF-6020, HBL: 4) 0.1 parts by mass (solid content 0.1 parts by mass), isocyanurate of hexamethylene diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., product name) : Coronate HX (C / HX)) 3 parts by mass (solid content 3 parts by mass), 2 parts by mass of dibutyltin dilaurate (1% by mass ethyl acetate solution) (solid content 0.02 parts by mass) as a crosslinking catalyst, Mixing and stirring were performed to prepare an acrylic pressure-sensitive adhesive 1 solution.

<Preparation of topcoat layer solution (topcoat 1)>
Polyester resin Vylonal MD-1480 (25% aqueous solution, manufactured by Toyobo Co., Ltd.) as a binder, polyaniline sulfonic acid (aqua-PASS, weight average molecular weight 40,000, manufactured by Mitsubishi Rayon Co.) as a conductive polymer, and diisopropylamine as a crosslinking agent Blocked hexamethylene diisocyanate isocyanurate, as a lubricant, oleic acid amide in a mixed solvent of water / ethanol (1/3), binder in a solid content of 100 parts by mass, conductive polymer in a solid content of 75 parts by mass, 10 parts by mass of the cross-linking agent and 30 parts by mass of the lubricant were added, and the mixture was stirred and mixed well for about 20 minutes. In this way, a solution for topcoat layer (topcoat 1) having an NV of about 0.4% was prepared.

<Preparation of resin layer film with topcoat layer (topcoat layer, first resin layer, adhesive layer, and second resin layer in this order)>
One side of the resin layer film was subjected to corona treatment, and the topcoat layer solution was applied to the corona-treated surface so that the thickness after drying was 30 nm. The coated material is heated to 130 ° C. for 1 minute and dried to prepare a resin layer film with a topcoat layer (in order of the topcoat layer, the first resin layer, the adhesive layer, and the second resin layer). did.

<Preparation of pressure-sensitive adhesive sheet (surface protective film)>
The acrylic pressure-sensitive adhesive solution is applied to the surface opposite to the topcoat layer of the resin layer with the topcoat layer (in order of the topcoat layer, the first resin layer, the adhesive layer, and the second resin layer), and 130 The adhesive layer having a thickness of 20 μm was formed by heating at 0 ° C. for 1 minute. Next, a silicone-treated surface of a polyethylene terephthalate film (thickness 25 μm), which is a separator having a silicone treatment on one side, was bonded to the surface of the pressure-sensitive adhesive layer to produce a pressure-sensitive adhesive sheet (surface protective film).

[Example 5]
<Preparation of urethane-based 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), a trimethylolpropane / tolylene diisocyanate trimer adduct as a polyfunctional isocyanate compound ( Nippon Polyurethane Industry Co., Ltd., trade name: Coronate L): 13 parts by mass (solid content), organopolysiloxane having an oxyalkylene chain (manufactured by Shin-Etsu Chemical Co., Ltd., trade names: KF-6004, HLB: 9) 1 part by weight, catalyst (manufactured by Nippon Kagaku Sangyo Co., Ltd., trade name: Nursem Ferric) 0.04 part by weight, 210 parts by weight of ethyl acetate as a diluent solvent, stirred with a disper, urethane-based adhesive composition (Solution) was obtained.

<Preparation of pressure-sensitive adhesive sheet (surface protective film)>
The urethane-based pressure-sensitive adhesive solution is applied to the surface opposite to the topcoat layer of the resin layer with a topcoat layer (in order of the topcoat layer, the first resin layer, the adhesive layer, and the second resin layer), and 130 Heating was carried out at 0 ° C. for 1 minute to form a pressure-sensitive adhesive layer having a thickness of 20 μm. Next, a silicone-treated surface of a polyethylene terephthalate film (thickness 25 μm), which is a separator having a silicone treatment on one side, was bonded to the surface of the pressure-sensitive adhesive layer to produce a pressure-sensitive adhesive sheet (surface protective film).

[Comparative Example 1]
<Preparation of topcoat layer solution (topcoat 3)>
Polyester resin Vylonal MD-1480 (25% aqueous solution, manufactured by Toyobo Co., Ltd.) as the binder, poly (3,4-ethylenedioxythiophene) (PEDOT) 0.5% and polystyrene sulfonate (weight average molecular weight 150,000) as the conductive polymer (PSS) 0.8% aqueous solution (Bytron P, manufactured by HC Stark Co.) in a water / ethanol (1/1) mixed solvent, 100 parts by mass of binder in solid content, and conductive polymer 50 parts by mass of solid content and 5 parts by mass of melamine-based crosslinking agent were added, and the mixture was stirred for about 20 minutes and thoroughly mixed. In this way, a topcoat layer solution (topcoat 3) having an NV of about 0.4% was prepared.

[Comparative Example 3]
<Preparation of topcoat layer solution (topcoat 5)>
In a water-alcohol solvent, an antistatic agent made of a cationic polymer (trade name “Bondip-P Main Agent” manufactured by Konishi Co., Ltd.) and an epoxy resin as a curing agent (Konishi Corporation product, trade name “Bonbon” A solution for the topcoat layer (topcoat 5) containing 100% to 46.7 mass ratio of the dip-P curing agent ”) on the NV basis was prepared.
One side of the resin layer film having the structure shown in Table 4 is subjected to corona treatment, and the top coat layer solution (top coat 5) is applied to the corona treatment surface so that the thickness after drying is 60 nm, at 130 ° C. The top coat layer was formed by heating for 1 minute and drying. Next, a long-chain alkyl carbamate-based release treatment agent (on the other hand, “Ore Industries Co., Ltd., trade name“ Pyroyl 1010 ”) as a slip agent is applied to the surface of the top coat layer so as to be 40 nm on the basis of NV. And it heated at 130 degreeC for 1 minute, and was dried, and the topcoat layer used as 2 layer structure was formed.

[Comparative Example 6]
<Preparation of resin layer film (first resin layer, adhesive layer, and second resin layer in this order)>
In a reaction vessel equipped with a cooling pipe, a nitrogen introduction pipe, 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) Then, 0.2 parts by mass of 2,2 ′ azobisisonitrile and ethyl acetate were added and reacted at 60 ° C. for 6 hours with stirring under a nitrogen gas stream to obtain an acrylic polymer solution having a weight average molecular weight of 1.1 million. It was. 1.0 mass part of epoxy compound [TETRAD-C manufactured by Mitsubishi Gas Chemical Co., Ltd.] and urethane acrylate compound [UV-1700B manufactured by Nippon Synthetic Chemical Industry Co., Ltd.] 40 with respect to 100 mass parts of the polymer solid content of this acrylic polymer solution. 40 parts by mass of acrylate compound [manufactured by Nippon Kayaku Co., Ltd., KAYARAD DPCA-120], 7 parts by mass of 1-hydroxycyclohexyl phenyl ketone (trade name: IRGACURE 184) [manufactured by Ciba Specialty Chemicals Co., Ltd.] Then, an acrylic adhesive 2 composition solution was prepared.

As the resin layer, the above-mentioned adhesive composition solution was applied on a polyester resin film (manufactured by Toyobo Co., Ltd., trade name: E5000, thickness: 38 μm, tensile strength: 208 MPa), heated at 90 ° C. to a thickness of 12 μm. The adhesive layer was formed.
Thereafter, a polyester resin film (manufactured by Toyobo Co., Ltd., trade name: E5000, thickness: 38 μm, tensile strength: 208 MPa) is laminated on the adhesive layer so that the integrated light quantity becomes 0.5 J / cm ² with a high-pressure mercury lamp. The adhesive layer was cured by irradiating with UV light to obtain a resin layer film having a thickness of 88 μm. The obtained adhesive layer had a storage elastic modulus at 23 ° C. of 6.7 × 10 ⁷ Pa.

[Examples 2 to 7 and Comparative Examples 1 to 6]
Based on the contents of Tables 1 and 2, adhesive sheets (surface protective films) were produced in the same manner as in Example 1. Other additives not blended in Example 1 (for example, antistatic components blended when preparing the adhesive solution) were blended when preparing the adhesive solution. In Comparative Example 5, only the second resin layer shown in Table 4 was used instead of the resin layer film. The compounding amounts in Tables 1 and 2 indicate solid contents.

  Tables 3 and 4 show the results of various measurements and evaluations described above for the pressure-sensitive adhesive sheets according to Examples and Comparative Examples.

Abbreviations in Table 1 and Table 2 will be described below.
2EHA: 2-ethylhexyl acrylate BA: n-butyl acrylate HEA: 2-hydroxyethyl acrylate AA: acrylic acid KF352A: organopolysiloxane having an oxyalkylene chain (HLB value: 7) (trade name: KF, manufactured by Shin-Etsu Chemical Co., Ltd.) -352A)
KF353: Organopolysiloxane having an oxyalkylene chain (HLB value: 10) (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KF-353)
KF355A: Organopolysiloxane having an oxyalkylene chain (HLB value: 12) (trade name: KF-355A, manufactured by Shin-Etsu Chemical Co., Ltd.)
KF6004: Organopolysiloxane having an oxyalkylene chain (HLB value: 9) (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KF-6004)
KF6020: Organopolysiloxane having an oxyalkylene chain (HLB value: 4) (trade name: KF-6020, manufactured by Shin-Etsu Chemical Co., Ltd.)
C / HX: Isocyanurate of hexamethylene diisocyanate (manufactured by Nippon Polyurethane Co., Ltd., trade name: Coronate HX)
BMP: 1-butyl-3-methylpyridinium bis (trifluoromethanesulfonyl) imide (ionic liquid, liquid at 25 ° C., Wako Pure Chemical Industries, Ltd.)
LiTFSI: Lithium bis (trifluoromethanesulfonyl) imide (alkali metal salt, Kishida Chemical Co., Ltd.)
Polyethylene naphthalate resin 12 μm: (manufactured by Teijin DuPont, trade name: Teonex Q51, tensile strength: 311 MPa)
Polyethylene naphthalate resin 50 μm: (manufactured by Teijin DuPont, trade name: Teonex Q51, tensile strength: 272 MPa)
Polyester resin 25 μm: (manufactured by Teijin DuPont, trade name: G2, tensile strength: 261 MPa)
Polyester resin 38 μm: (Toyobo Co., Ltd., trade name: E5000, tensile strength: 208 MPa)
Polyester resin 75 μm: (Toyobo, trade name: E5000, tensile strength: 188 MPa)
Polycarbonate resin 65 μm: (manufactured by Kaneka Co., Ltd., trade name: ELMEC, tensile strength: 105 MPa)

  From the above evaluation results, in all examples, by using a pressure-sensitive adhesive sheet having a desired thickness ratio, storage elastic modulus of the adhesive layer, pressure-sensitive adhesive layer, topcoat layer, and the like, antistatic properties, pressure-sensitive adhesive properties, It was confirmed that the pickup property, the deflection amount, and the print adhesion were excellent. On the other hand, in the comparative example, since a pressure-sensitive adhesive sheet having a desired ratio of desired thickness, a pressure-sensitive adhesive layer, a top coat layer, and the like was not used, a sheet satisfying all the characteristics could not be obtained.

  The pressure-sensitive adhesive sheet disclosed herein is an optical member used in manufacturing and transporting optical members used as components of liquid crystal display panels, plasma display panels (PDP), organic electroluminescence (EL) displays, touch panel displays, and the like. It is suitable as an adhesive sheet (surface protective film) for protection. In particular, pressure-sensitive adhesive sheets (optical pressure-sensitive adhesive sheets) applied to optical members such as polarizing plates (polarizing films), wavelength plates, phase difference plates, optical compensation films, brightness enhancement films, light diffusion sheets, and reflective sheets for liquid crystal display panels ) Is useful.

1 Adhesive sheet (surface protective film)
DESCRIPTION OF SYMBOLS 1A Surface of topcoat layer 2 Polarizing plate 3 Acrylic plate 4 Fixing stand 5 Potential measuring device 6 First resin layer 7 Adhesive layer 8 Second resin layer 12 Resin layer film (first resin layer + adhesive layer + second Resin layer)
14 Topcoat layer 20 Adhesive layer 20A Adhesive surface 50 Plain polarizing plate 60 Single-sided adhesive tape 62 Adhesive layer (adhesive surface)
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)

A first resin layer, an adhesive layer, a second resin layer, and a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition in this order;
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 storage elastic modulus at 23 ° C. of the adhesive layer is 1.0 × 10 ⁴ Pa or more and less than 5.0 × 10 ⁷ Pa,
Having a topcoat layer on the surface of the first resin layer opposite to the surface having the pressure-sensitive adhesive layer;
The top coat layer is formed from a composition for a top coat layer containing polyaniline sulfonic acid as a conductive polymer component, a polyester resin as a binder component, and an isocyanate compound as a crosslinking agent,
The pressure-sensitive adhesive sheet, wherein the pressure-sensitive adhesive composition contains an organopolysiloxane having an oxyalkylene chain. The pressure-sensitive adhesive sheet according to claim 1, wherein the composition for a top coat layer further contains a fatty acid amide as a lubricant. The pressure-sensitive adhesive sheet according to claim 1 or 2, wherein at least one of the resin layers is a polyester film. The pressure-sensitive adhesive sheet according to any one of claims 1 to 3, wherein the pressure-sensitive adhesive composition contains an acrylic pressure-sensitive adhesive and / or a urethane-based pressure-sensitive adhesive. The pressure-sensitive adhesive sheet according to claim 1, wherein the pressure-sensitive adhesive composition contains an antistatic component. An optical member protected by the pressure-sensitive adhesive sheet according to claim 1.

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