JPWO2018056167A1 - Pressure-sensitive adhesive composition, pressure-sensitive adhesive sheet, and optical member - Google Patents

Abstract

The present invention provides an adhesive composition that can achieve antistatic properties and stability over time of a stripping voltage even when the optical member such as a polarizing plate is pasted and stored in a high temperature environment, and the adhesive. Provided are a pressure-sensitive adhesive sheet formed of a composition, and an optical member to which the pressure-sensitive adhesive sheet is attached. The pressure-sensitive adhesive composition of the present invention is characterized by containing a pressure-sensitive adhesive polymer and an ionic group-containing silicone represented by the following formula (1). (R1 to R4 may be the same or different and are any one of an alkyl group having 1 to 10 carbon atoms, an alkoxy group, an aryl group, an alicyclic group, a fluorine-substituted alkyl group, and an ionic group. And R 1 to R 4 contain an ionic group, and n is an integer of 0 to 100.)

Description

  The present invention relates to a pressure-sensitive adhesive composition, a pressure-sensitive adhesive sheet, and an optical member. In particular, the pressure-sensitive adhesive sheet obtained by the pressure-sensitive adhesive composition is used for sticking to plastic products and the like which easily generate static electricity (for example, liquid crystal display panel, plasma display panel (PDP), organic electroluminescence (EL) display, etc.) In particular, it is used for the purpose of protecting the surface of an optical member (for example, a polarizing plate used in a liquid crystal display, a wave plate, a retardation plate, an optical compensation film, a reflective sheet, a brightness enhancement film), etc. Useful as a surface protection film.

  The surface protective film (also referred to as a surface protective sheet) generally has a configuration in which a pressure-sensitive adhesive layer is provided on a film-like base film (support). Such a protective film is bonded to an adherend (object to be protected) via the pressure-sensitive adhesive layer, and thereby used for the purpose of protecting the adherend from scratches and dirt during processing, transportation, and the like. 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 layer. In the production of such a liquid crystal display panel, a polarizing plate to be bonded to a liquid crystal cell is once produced in a roll form, then unwound from the roll and cut into a desired size according to the shape of the liquid crystal cell . Here, in order to prevent the polarizing plate from being scratched by being rubbed with a transport roll or the like in an intermediate step, measures have been taken to attach a surface protective film to one side or both sides (typically, one side) of the polarizing plate. This surface protective film is peeled off and removed when it becomes unnecessary.

  Generally, the surface protection film and the optical member are made of a plastic material, so they have high electrical insulation and generate static electricity by friction or peeling. Therefore, static electricity is easily generated when peeling the surface protection film from an optical member such as a polarizing plate, and if a voltage is applied to the liquid crystal with this static electricity remaining, the alignment of the liquid crystal molecules may be lost. There is also a concern that a panel failure may occur. In addition, the presence of static electricity can be a factor that sucks in dust and reduces workability. Under these circumstances, antistatic treatment is performed on the surface protective film. For example, formation of an antistatic layer or antistatic coating as a surface layer (top coat layer, back layer) of the surface protective film is performed. Thus, the antistatic function is provided (see Patent Documents 1 and 2).

  Also, in order to impart antistatic properties to the pressure-sensitive adhesive layer itself constituting the surface protective film, it is carried out that the pressure-sensitive adhesive contains an ionic compound such as an alkali metal salt or an ionic liquid which functions as an antistatic agent. (See Patent Document 3).

  However, when the adhesive layer surface containing the ionic compound is attached to an optical member such as a polarizing plate and stored in a high temperature (warm) environment, the ionic compound penetrates from the surface of the optical member. The problem is that the antistatic ability of the ionic compound is lowered and the optical member can not be sufficiently protected.

JP 2004-223923 A JP 2008-255332 A Unexamined-Japanese-Patent No. 9-165460

  Then, as a result of earnestly researching in view of the above-mentioned circumstances, the present invention makes the antistatic property and the time-lapse stability of the peeling voltage even if the optical member such as a polarizing plate is attached and stored under high temperature environment. It is an object of the present invention to provide a pressure-sensitive adhesive composition capable of achieving the properties, a pressure-sensitive adhesive sheet formed of the pressure-sensitive adhesive composition, and an optical member to which the pressure-sensitive adhesive sheet is attached.

（Ｒ_１〜Ｒ_４は、同一でも異なっていてもよく、炭素数１〜１０のアルキル基、アルコキシ基、アリール基、アリサイクリック基、フッ素置換アルキル基、イオン性基のいずれかを含み、Ｒ_１〜Ｒ_４のうち1つ以上にイオン性基を含む。ｎは０〜１００の整数である。）That is, the pressure-sensitive adhesive composition of the present invention is characterized by containing a pressure-sensitive adhesive polymer and an ionic group-containing silicone represented by the following formula (1).

(R _{1 to} R ₄ may be the same or different, and include any of an alkyl group having 1 to 10 carbon atoms, an alkoxy group, an aryl group, an aliphatic group, a fluorine-substituted alkyl group, and an ionic group, One or more of R _{1 to} R ₄ contain an ionic group, and n is an integer of 0 to 100.)

  The pressure-sensitive adhesive composition of the present invention preferably contains an oxyalkylene group-containing compound.

  The pressure-sensitive adhesive composition of the present invention preferably contains at least one selected from the group consisting of an acrylic pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, and a silicone-based pressure-sensitive adhesive.

  The pressure-sensitive adhesive sheet of the present invention has a pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition on at least one surface of a substrate film, and the ionic group-containing inside and / or on the surface of the pressure-sensitive adhesive layer. It is preferred that silicone be present.

  In the pressure-sensitive adhesive sheet of the present invention, a separator is preferably attached to the side of the pressure-sensitive adhesive layer opposite to the side in contact with the base film.

  In the pressure-sensitive adhesive sheet of the present invention, the ionic group-containing silicone is preferably present on the surface of the separator in contact with the pressure-sensitive adhesive layer.

  In the optical member of the present invention, it is preferable that the pressure-sensitive adhesive sheet or a pressure-sensitive adhesive sheet obtained by peeling the separator from the pressure-sensitive adhesive sheet is attached.

  In the present invention, by using a pressure-sensitive adhesive composition containing a specific ionic group-containing silicone, a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition is used for an optical member such as a polarizing plate Even in the case of pasting and storage under a high temperature environment, it is useful because it can achieve excellent antistatic property and temporal stability of the peeling voltage.

It is a schematic cross section which shows one structural example of the adhesive sheet (surface protection film) which concerns on this invention. It is an explanatory view showing the measuring method of exfoliation charge voltage.

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

<Whole structure of adhesive sheet (surface protection film)>
The pressure-sensitive adhesive sheet disclosed herein is generally in the form referred to as a pressure-sensitive adhesive tape, a pressure-sensitive adhesive label, a pressure-sensitive adhesive film, etc., and in particular, used as an optical component Optical component) is suitable as a surface protection film for protecting the surface of the optical component during processing or transport. The pressure-sensitive adhesive layer in the surface protective film is typically formed continuously, but is not limited to such a form, and is formed, for example, in a regular or random pattern such as dot-like or stripe-like. It may be an adhesive layer. In addition, the surface protection film disclosed herein may be in the form of a roll or in the form of a single sheet.

<Base film>
The pressure-sensitive adhesive sheet (surface protective film) of the present invention is characterized by having a base film. In the technology disclosed herein, the resin material constituting the substrate film can be used without particular limitation, and examples thereof include transparency, mechanical strength, heat stability, water blocking property, isotropy, It is preferable to use one excellent in characteristics such as flexibility and dimensional stability. In particular, when the base film has flexibility, the pressure-sensitive adhesive composition can be applied by a roll coater or the like, and can be wound into a roll, which is useful.

  Examples of the substrate film (substrate, support) include polyester-based polymers such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN) and polybutylene terephthalate; cellulose-based polymers such as diacetyl cellulose and triacetyl cellulose; polycarbonate A plastic film composed of a resin material containing a base polymer; an acrylic polymer such as polymethyl methacrylate; etc. as a main resin component (a main component of the resin component, typically a component that occupies 50% by mass or more); It can be preferably used as the base film. As other examples of the resin material, styrene-based polymers such as polystyrene and acrylonitrile-styrene copolymer; olefin-based polymers such as polyethylene, polypropylene, polyolefin having a cyclic to norbornene structure, ethylene-propylene copolymer and the like; An example is a vinyl chloride-based polymer; an amide-based polymer such as nylon 6, nylon 6, 6 or aromatic polyamide; or the like as a resin material. Still other examples of the resin material include imide polymers, sulfone polymers, polyethersulfone polymers, polyetheretherketone polymers, polyphenylene sulfide polymers, vinyl alcohol polymers, vinylidene chloride polymers, vinyl butyral polymers And arylate polymers, polyoxymethylene polymers, epoxy polymers and the like. It may be a base film composed of a blend of two or more of the above-mentioned polymers.

  As the base film, a plastic film made of a transparent thermoplastic resin material can be preferably employed. Among the plastic films, it is a more preferable aspect to use a polyester film. Here, the polyester film is mainly composed of a polymer material (polyester resin) having a main skeleton based on an ester bond, such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate etc. Say. Such a polyester film has preferable characteristics as a base film of a surface protection film, such as excellent optical characteristics and dimensional stability, and has a property of being easily charged as it is.

  If necessary, various additives such as an antioxidant, an ultraviolet absorber, a plasticizer, a colorant (pigment, dye, etc.) may be blended in the resin material constituting the base film. For example, known or common surface treatments such as corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, application of a primer may be applied. Such surface treatment may be, for example, treatment for enhancing the adhesion between the base film and the pressure-sensitive adhesive layer (the anchoring property of the pressure-sensitive adhesive layer).

  The pressure-sensitive adhesive sheet (surface protective film) of the present invention can also use a plastic film subjected to an antistatic treatment as the base film. By using the said base film, since the electrical charging of adhesive sheet itself at the time of peeling is suppressed, it is preferable. Further, the substrate film is a plastic film, and by subjecting the plastic film to an antistatic treatment, charging of the pressure-sensitive adhesive sheet itself can be reduced, and an antistatic performance to an adherend can be excellent. In addition, there is no restriction | limiting in particular as a method of providing an antistatic function, A conventionally well-known method can be used, For example, antistatic resin, an electroconductive polymer, an electroconductive substance which consists of an antistatic agent and a resin component The method of applying the conductive resin to be contained, the method of depositing or plating the conductive substance, the method of kneading the antistatic agent and the like, and the like can be mentioned.

  The thickness of the base film is generally 5 to 200 μm, preferably about 10 to 100 μm. It is preferable for the thickness of the base film to be in the above-mentioned range, since the bonding workability to the adherend and the peeling workability from the adherend are excellent.

  The pressure-sensitive adhesive sheet disclosed herein can also be practiced in a mode including another layer in addition to the base film and the pressure-sensitive adhesive layer. As said other layer, the undercoat layer (anchor layer) etc. which improve the anchoring property of an antistatic layer and an adhesive layer are mentioned.

<Adhesive composition>
The pressure-sensitive adhesive sheet of the present invention has the above-mentioned pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer is formed of a pressure-sensitive adhesive composition, and the pressure-sensitive adhesive composition particularly has adhesiveness. It can be used without restriction. As the pressure-sensitive adhesive composition, for example, an acrylic pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, a synthetic rubber-based pressure-sensitive adhesive, a natural rubber-based pressure-sensitive adhesive, a silicone pressure-sensitive adhesive can be used. At least one selected from the group consisting of acrylic pressure-sensitive adhesives, urethane-based pressure-sensitive adhesives, and silicone-based pressure-sensitive adhesives, and particularly preferably, acrylic-based adhesion using a (meth) acrylic-based polymer which is an adhesive polymer To use an agent.

  When the pressure-sensitive adhesive layer uses an acrylic pressure-sensitive adhesive, the (meth) acrylic-based polymer which is a pressure-sensitive polymer constituting the acrylic pressure-sensitive adhesive is an alkyl having 1 to 14 carbon atoms as a raw material monomer constituting the same. A (meth) acrylic monomer having a group can be used as a main monomer. As said (meth) acrylic-type monomer, 1 type (s) or 2 or more types can be used. By using the (meth) acrylic monomer having an alkyl group having 1 to 14 carbon atoms, it becomes easy to control the peeling force (adhesive force) to the adherend (object to be protected) low, and light peeling A pressure-sensitive adhesive sheet (surface protective film) having excellent properties and removability 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 an acrylate and / or a methacrylate.

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

  Among them, in the case of a surface protective film as the adhesive sheet of the present invention, n-butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl ( Meta) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-dodecyl (meth) acrylate, n-tridecyl (meth) acrylate, n- A (meth) acrylic monomer having an alkyl group having 4 to 14 carbon atoms, such as tetradecyl (meth) acrylate, is preferably exemplified. In particular, by using a (meth) acrylic monomer having an alkyl group having 4 to 14 carbon atoms, it becomes easy to control the peel strength (adhesive force) to the adherend low, and the removability is excellent It becomes.

  In particular, it is preferable to contain 50 mass% or more of (meth) acrylic monomers having an alkyl group having 1 to 14 carbon atoms with respect to 100 mass% of the total amount of monomer components constituting the (meth) acrylic polymer. It is more preferably 80% by mass or more, still more preferably 85 to 99.9% by mass, and most preferably 90 to 99% by mass. When the amount is less than 50% by mass, the wettability of the pressure-sensitive adhesive composition and the cohesion of the pressure-sensitive adhesive layer are deteriorated, which is not preferable.

  Furthermore, in the pressure-sensitive adhesive composition of the present invention, the (meth) acrylic polymer preferably contains a hydroxyl group-containing (meth) acrylic monomer as a raw material monomer. As said hydroxyl group containing (meth) acrylic-type monomer, 1 type (s) or 2 or more types can be used. By using the hydroxyl group-containing (meth) acrylic monomer, it becomes easy to control the crosslinking of the pressure-sensitive adhesive composition, and the balance between improvement of wettability by flow and reduction of peeling force (adhesive force) at peeling is achieved. It becomes easy to control. Furthermore, unlike carboxyl groups and sulfonate groups that generally act as crosslinking sites, hydroxyl groups have an appropriate interaction with ionic group-containing silicones and oxyalkylene group-containing compounds that are antistatic components (antistatic agents). In the aspect of antistatic property, it can be suitably used.

  Examples of the hydroxyl group-containing (meth) acrylic monomers include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate and 6-hydroxyhexyl (meth) acrylate. And 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxy lauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) methyl acrylate, N-methylol (meth) acrylamide, etc. . In particular, by using a hydroxyl group-containing (meth) acrylic monomer having 4 or more carbon atoms in the alkyl group, light peeling at the time of high-speed peeling is facilitated, which is preferable.

  The hydroxyl group-containing (meth) acrylic monomer is preferably contained in an amount of 25% by mass or less, more preferably 20% by mass or less, based on 100% by mass of the total amount of monomer components constituting the (meth) acrylic polymer. More preferably, it is 0.1 to 15% by mass, and most preferably 1 to 10% by mass. Within the above range, the balance between the wettability of the pressure-sensitive adhesive composition and the cohesion of the resulting pressure-sensitive adhesive layer can be easily controlled, which is preferable.

  Moreover, as another polymerizable monomer component, the glass transition temperature or peeling of the (meth) acrylic polymer is performed so that Tg is 0 ° C. or less (usually −100 ° C. or more) because the adhesion performance can be easily balanced. Polymerizable monomers and the like for adjusting the properties can be used as long as the effects of the present invention are not impaired.

  Examples of the (meth) acrylic monomer having an alkyl group having 1 to 14 carbon atoms used in the (meth) acrylic polymer, and other polymerizable monomers other than the hydroxyl group-containing (meth) acrylic monomer A carboxyl group-containing (meth) acrylic monomer can be used. By using the carboxyl group-containing (meth) acrylic monomer, it is possible to suppress the increase in the adhesive strength of the pressure-sensitive adhesive sheet (adhesive layer) with time, and the removability, the adhesive strength increase preventing property, and the workability. In addition to the cohesion of the pressure-sensitive adhesive layer, it is also excellent in shear force.

  Examples of the carboxyl group-containing (meth) acrylic monomer include (meth) acrylic acid, carboxylethyl (meth) acrylate and carboxylpentyl (meth) acrylate.

  It is preferable that it is 0-5 mass% with respect to the said carboxyl group-containing (meth) acrylic-type monomer with respect to the monomer component whole quantity 100 mass% which comprises the said (meth) acrylic-type polymer, and is 0-3 mass%. Is more preferably 0 to 2% by mass, and most preferably 0 to 0.19% by mass. When it exceeds 5% by mass, many acid functional groups such as carboxyl groups having a large polar action exist, and when the ionic group-containing silicone or the oxyalkylene group-containing compound as the antistatic component is compounded, the above antistatic component For example, the interaction of an acid functional group such as a carboxyl group may interfere with ion conduction, reduce the conduction efficiency, and may not be able to obtain sufficient antistatic properties, which is not preferable.

  When the hydroxyl group-containing (meth) acrylic monomer and the carboxyl group-containing (meth) acrylic monomer are used in combination, the total amount of the monomer components constituting the (meth) acrylic polymer is 100% by mass. Preferably, the content of the carboxyl group-containing (meth) acrylic monomer is 0.01 to 0.19% by mass. By adjusting the amount within the above range, a pressure-sensitive adhesive composition excellent in the removability and the adhesive strength increase preventing property can be obtained while maintaining the antistatic property, which is effective.

  Furthermore, the (meth) acrylic monomer having an alkyl group having 1 to 14 carbon atoms, the hydroxyl group-containing (meth) acrylic monomer, and the carboxyl group-containing (meth) acrylic compound used in the (meth) acrylic polymer As other polymerizable monomers other than a monomer, if it is in the range which does not impair the characteristic of this invention, it can use, without specifically limiting. For example, cohesive force / heat resistance improving component such as cyano group-containing monomer, vinyl ester monomer, aromatic vinyl monomer, amide group-containing monomer, imide group-containing monomer, amino group-containing monomer, epoxy group-containing monomer, N-acryloyl morpholine A component having a functional group which works as an improvement in peeling force (adhesive force) or a crosslinking point, such as a vinyl ether monomer, can be appropriately used. Among them, it is preferable to use a cyano group-containing monomer, an amido group-containing monomer, an imide group-containing monomer, an amino group-containing monomer, and a nitrogen-containing monomer such as N-acryloyl morpholine. By using a nitrogen-containing monomer, it is possible to secure an appropriate peeling force (adhesive force) that does not cause floating or peeling, and further to obtain a pressure-sensitive adhesive sheet (surface protective film) excellent in shear force, which is useful. . These polymerizable monomers can be used alone or in combination of two or more.

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

  Examples of the amide group-containing monomer include acrylamide, methacrylamide, diethyl acrylamide, N-vinyl pyrrolidone, N, N-dimethyl acrylamide, N, N- dimethyl methacrylamide, N, N- diethyl acrylamide, N, N- diethyl Methacrylamide, N, N'-methylenebisacrylamide, N, N-dimethylaminopropyl acrylamide, N, N-dimethylaminopropyl methacrylamide, diacetone acrylamide and the like can be mentioned.

  Examples of the imide group-containing monomer include cyclohexyl maleimide, isopropyl maleimide, N-cyclohexyl maleimide, itaconimide and the like.

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

  Examples of the vinyl ester monomer include vinyl acetate, vinyl propionate and vinyl laurate.

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

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

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

  In the present invention, other polymerizable monomers other than (meth) acrylic monomers having an alkyl group having 1 to 14 carbon atoms, hydroxyl group-containing (meth) acrylic monomers, and carboxyl group-containing (meth) acrylic monomers are as described above. It is preferable that it is 0-50 mass% with respect to 100 mass% of monomer components whole quantity which comprises a (meth) acrylic-type polymer, and it is more preferable that it is 0-20 mass%. The other polymerizable monomers can be appropriately adjusted to obtain desired properties.

  The (meth) acrylic polymer may further contain an alkylene oxide group-containing reactive monomer as a monomer component.

  The average addition mole number of the oxyalkylene unit of the alkylene oxide group-containing reactive monomer is 1 to 40 from the viewpoint of compatibility with the ionic group-containing silicone which is the antistatic component and the oxyalkylene group-containing compound. Is preferable, 3 to 40 is more preferable, 4 to 35 is more preferable, and 5 to 30 is particularly preferable. When the average addition mole number is 1 or more, the contamination reduction effect of the adherend (object to be protected) tends to be efficiently obtained. In addition, when the average addition mole number is larger than 40, the interaction with the ionic group-containing silicone and the oxyalkylene group-containing compound tends to be large, and the viscosity of the pressure-sensitive adhesive composition tends to increase and coating becomes difficult. Unfavorable because there is. In addition, the terminal of the oxyalkylene chain may be substituted with a hydroxyl group as it is or with another functional group.

  The alkylene oxide group-containing reactive monomer may be used alone or in combination of two or more, but the total content is the total amount of the monomer components of the (meth) acrylic polymer Among them, 0 to 20% by mass is preferable, and 0 to 10% by mass is more preferable. When the content of the alkylene oxide group-containing reactive monomer exceeds 20% by mass, the interaction with the ionic group-containing silicone and the oxyalkylene group-containing compound becomes large, the ion conduction is interrupted, and the antistatic property is lowered. It is not preferable.

  As an oxyalkylene unit of the said alkylene oxide group containing reactive monomer, what has a C1-C6 alkylene group is mention | raise | lifted, For example, oxymethylene group, oxyethylene group, oxypropylene group, oxybutylene group etc. are given. Be The hydrocarbon group of the oxyalkylene chain may be linear or branched.

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

  As the alkylene oxide group-containing reactive monomer, for example, a (meth) acrylic acid alkylene oxide adduct, a reactive surfactant having a reactive substituent such as an acryloyl group, a methacryloyl group or an allyl group in the molecule, etc. can give.

  Specific examples of the (meth) acrylic acid alkylene oxide adduct include polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, polyethylene glycol-polypropylene glycol (meth) acrylate, polyethylene glycol-polybutylene glycol (meth) ) Acrylate, polypropylene glycol-polybutylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, ethoxypolyethylene glycol (meth) acrylate, butoxy polyethylene glycol (meth) acrylate, octoxy polyethylene glycol (meth) acrylate, lauroxy polyethylene Glycol (meth) acrylate, stearoxy polyethylene glycol Le (meth) acrylate, phenoxy polyethylene glycol (meth) acrylate, methoxy polypropylene glycol (meth) acrylate, octoxypolyethylene glycol - polypropylene glycol (meth) acrylate.

  Further, specific examples of the reactive surfactant include, for example, an anionic reactive surfactant having a (meth) acryloyl group or an allyl group, a nonionic reactive surfactant, a cationic reactive surfactant and the like. Can be mentioned.

  The (meth) acrylic polymer preferably has a weight average molecular weight (Mw) of 100,000 to 5,000,000, more preferably 200,000 to 4,000,000, still more preferably 300,000 to 3,000,000, and most preferably 300,000 to 950,000. It is. If the weight average molecular weight is less than 100,000, the adhesive force of the pressure-sensitive adhesive layer tends to be reduced to cause adhesive residue. On the other hand, when the weight average molecular weight exceeds 5,000,000, the flowability of the polymer decreases, and the wetting to the adherend (for example, a polarizing plate) becomes insufficient, and the adherend and the adhesive sheet (surface protective film) It tends to cause the swelling that occurs between it and the pressure-sensitive adhesive layer. In addition, a weight average molecular weight says what was obtained by measuring by GPC (gel permeation chromatography).

  The glass transition temperature (Tg) of the (meth) acrylic polymer is preferably 0 ° C. or less, more preferably −10 ° C. or less (usually −100 ° C. or more). When the glass transition temperature is higher than 0 ° C., the polymer is difficult to flow, for example, the wetting to the polarizing plate as an optical member becomes insufficient, and between the polarizing plate and the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet (surface protective film) It tends to cause the swelling that occurs. In particular, by setting the glass transition temperature to −61 ° C. or less, a pressure-sensitive adhesive layer excellent in wettability to a polarizing plate and light releasability can be 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 the polymerization can be carried out by a known method such as solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization, etc. Solution polymerization is a more preferable embodiment in terms of characteristics such as low contamination to an adherend (object to be protected). Further, the polymer to be obtained may be any of random copolymer, block copolymer, alternating copolymer, graft copolymer and the like.

  When using a urethane type adhesive for the said adhesive layer, arbitrary appropriate urethane type adhesives can be employ | adopted. As such a urethane type adhesive, what consists of a urethane type polymer which is an adhesive polymer preferably obtained by making a polyol and a polyisocyanate compound react is mentioned. Examples of polyols include polyether polyols, polyester polyols, polycarbonate polyols, polycaprolactone polyols and the like. As a polyisocyanate compound, diphenylmethane diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate etc. are mentioned, for example.

  When using a silicone-based pressure-sensitive adhesive in the pressure-sensitive adhesive layer, any suitable silicone-based pressure-sensitive adhesive may be employed. As such a silicone-based pressure-sensitive adhesive, preferably, one obtained by blending or aggregating a silicone-based polymer which is an adhesive polymer can be employed.

  Further, examples of the silicone-based pressure-sensitive adhesive include an addition reaction-curable silicone-based pressure-sensitive adhesive and a peroxide-curable silicone-based pressure-sensitive adhesive. Among these silicone-based pressure-sensitive adhesives, addition reaction-curable silicone-based pressure-sensitive adhesives are preferable because peroxides (such as benzoyl peroxide) are not used and decomposition products are not generated.

  As a curing reaction of the addition reaction-curable silicone-based pressure-sensitive adhesive, for example, in the case of obtaining a polyalkyl silicone-based pressure-sensitive adhesive, generally, a method of curing a polyalkyl hydrogen siloxane composition with a platinum catalyst can be mentioned.

なお、上記式（１）中のＲ_１〜Ｒ_４は、同一でも異なっていてもよく、炭素数１〜１０のアルキル基、アルコキシ基、アリール基、アリサイクリック基、フッ素置換アルキル基、イオン性基のいずれかを含み、Ｒ_１〜Ｒ_４のうち1つ以上にイオン性基を含む。ｎは０〜１００の整数である。<Ionic group-containing silicone>
The pressure-sensitive adhesive composition of the present invention is characterized by containing a pressure-sensitive adhesive polymer and an ionic group-containing silicone represented by the following formula (1). By containing the ionic group-containing silicone in the pressure-sensitive adhesive composition, the pressure-sensitive adhesive layer is attached to the surface of an adherend (for example, a polarizing plate) by low surface free energy of the silicone chain under a high temperature environment. Even when stored, the ionic group-containing silicone does not penetrate into the adherend (from the adherend surface to the inside of the adherend) and tends to stay on the surface of the pressure-sensitive adhesive layer. The charging characteristics are stabilized, and the antistatic performance is maintained for a long time, which is a preferable embodiment. In addition, when "the inside" of the said adhesive layer is contained in the said adhesive layer, when an adhesive layer is formed using the said adhesive composition which mix | blended the said ionic group containing silicone, for example Point to The “surface” of the pressure-sensitive adhesive layer means, for example, the pressure-sensitive adhesive layer when the pressure-sensitive adhesive layer is formed using the pressure-sensitive adhesive composition containing or not containing the ionic group-containing silicone. When the ionic group-containing silicone is applied (laminated) in advance to the separator surface to be attached to protect the surface of the agent layer and the separator is attached to the pressure-sensitive adhesive layer, the separator surface is It refers to the case where the ionic group-containing silicone is transferred (migrated) to the surface of the pressure-sensitive adhesive layer.

R _{1 to} R ₄ in the above-mentioned formula (1) may be the same or different, and an alkyl group having 1 to 10 carbon atoms, an alkoxy group, an aryl group, an alicyclic group, a fluorine-substituted alkyl group, an ion It contains any of the sex groups, and one or more of R _{1 to} R ₄ contain an ionic group. n is an integer of 0 to 100.

As the ionic groups contained in one or more of R ₁ to R _4, ammonium cationic groups, or ionic groups having phosphonium cation group. Among them, one or more of R _{1 to} R ₄ are preferably composed of a cation structure represented by the following formula (a) or (b) and an anion component, or represented by (c) or (d) Preferably have a zwitterionic structure.

上記式（ａ）中のＲ_５〜Ｒ_７は、同一でも異なっていてもよく、炭素数１〜１０のアルキル基、アリール基、フッ素置換アルキル基のいずれかを示す。ｍは１〜１０の整数である。

R _{5 to} R ₇ in the above formula (a) may be the same or different, and represent any of an alkyl group having 1 to 10 carbon atoms, an aryl group, and a fluorine-substituted alkyl group. m is an integer of 1 to 10.

上記式（ｂ）中のＲ_８〜Ｒ_１０は、同一でも異なっていてもよく、炭素数１〜１０のアルキル基、アリール基、フッ素置換アルキル基のいずれかを示す。ｍは１〜１０の整数である。

R _{8 to} R ₁₀ in the above formula (b) may be the same or different, and represent any of an alkyl group having 1 to 10 carbon atoms, an aryl group, and a fluorine-substituted alkyl group. m is an integer of 1 to 10.

On the other hand, the anion component is not particularly limited. For example, Cl ⁻ , Br ⁻ , I ⁻ , AlCl ₄ ⁻ , Al ₂ Cl ₇ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , ClO ₄ ⁻ , NO ₃ ⁻ , CH ₃ COO ⁻ , CF ₃ COO ⁻ , CH ₃ SO ₃ ⁻ , CF ₃ SO ₃ ⁻ , C ₄ F ₉ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , (C ₃ F ₇ SO ₂ ) ₂ N ⁻ , (C ₄ F ₉ SO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₃ C ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , NbF ₆ ⁻ , TaF ₆ ⁻ , F (HF) _n ⁻ , (CN) ₂ N ⁻ , C ₄ F ₉ SO ₃ ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , C ₃ F ₇ COO ⁻ , (CF ₃ SO ₂ ) (CF ₃ ) _{^{3 CO) N -, C 9}} H 19 COO -, (CH 3) _{^{PO 4 -, (C 2 H}} 5) 2 PO 4 -, C 2 H 5 OSO 3 -, C 6 H 13 OSO 3 -, C 8 H 17 OSO 3 -, CH 3 (OC 2 H 4) 2 OSO 3 _{^{-, C 6 H 4 (CH}} 3) SO 3 -, (C 2 F 5) 3 PF 3 -, CH 3 CH (OH) COO -, _{and, (FSO 2) 2} N ^- and the like are used.

上記式（ｃ）中のＲ_１１、Ｒ_１２は、同一でも異なっていてもよく、炭素数１〜１０のアルキル基、アリール基、フッ素置換アルキル基のいずれかを示し、Ｒ_１１、Ｒ_１２は環を形成していてもよく、その場合はアルキレン基を表す。ｍは１〜１０の整数、ｐは１〜６の整数である。

_{R 11, R 12} in the formula (c) may be the same or different, indicate one alkyl group having 1 to 10 carbon atoms, an aryl group, a fluorine-substituted alkyl _group, R _{11, R 12} is It may form a ring, in which case it represents an alkylene group. m is an integer of 1 to 10, and p is an integer of 1 to 6.

上記式（ｄ）中のＲ_１３、Ｒ_１４は、同一でも異なっていてもよく、炭素数１〜１０のアルキル基、アリール基、フッ素置換アルキル基のいずれかを示し、Ｒ_１３、Ｒ_１４は環を形成してもよく、その場合はアルキレン基を表す。ｍは１〜１０の整数、ｐは１〜６の整数である。

_{R 13, R 14} in the formula (d) may be the same or different, indicates an alkyl group having 1 to 10 carbon atoms, an aryl group, any of fluorine-substituted alkyl _group, R _{13, R 14} is It may form a ring, in which case it represents an alkylene group. m is an integer of 1 to 10, and p is an integer of 1 to 6.

  Since such an ionic group-containing silicone contains a silicone chain, it is stored in a high temperature environment with the pressure-sensitive adhesive layer attached to the surface of an adherend (for example, a polarizing plate) by low surface free energy of the silicone chain. Even in the case of peeling, the ionic group-containing silicone does not penetrate into the adherend (from the surface of the adherend to the inside of the adherend) and tends to stay on the surface of the pressure-sensitive adhesive layer. The characteristics are stabilized, the antistatic performance is maintained for a long time, and it can be suitably used as an antistatic agent.

  As a specific example of the said ionic group containing silicone, the brand name X-40-2450 of a commercial item, X-40-2750 (above, Shin-Etsu Chemical Co., Ltd. make) etc. are mention | raise | lifted. These compounds may be used alone or in combination of two or more.

  The content of the ionic group-containing silicone is 100 parts by mass of an adhesive polymer (main polymer, for example, (meth) acrylic polymer, urethane polymer, silicone polymer, etc.) constituting the pressure-sensitive adhesive composition. On the other hand, 0.01 to 10 parts by mass is preferable, more preferably 0.02 to 7.5 parts by mass, still more preferably 0.03 to 5.5 parts by mass, and most preferably 0.04 to 4 parts. 8 parts by mass. Within the above range, the pressure-sensitive adhesive sheet of the present invention is attached to an optical member or the like, and even when stored in a high temperature environment, the antistatic property, the temporal stability of peel voltage, light peelability (re Peelability) is preferable and preferable. Moreover, in order to satisfy stain resistance, 0.01 to 5.5 parts by mass is preferable with respect to 100 parts by mass of the adhesive polymer.

<Oxyalkylene Group-Containing Compound>
The pressure-sensitive adhesive composition of the present invention preferably contains an oxyalkylene group-containing compound, and more preferably contains an organopolysiloxane having an oxyalkylene chain, and contains an organopolysiloxane having an oxyalkylene main chain. It is more preferable to do. By using the organopolysiloxane, the surface free energy of the pressure-sensitive adhesive surface is reduced, and it is presumed that light peeling is realized.

なお、上記式（２）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, although a known organopolysiloxane having a polyoxyalkylene main chain can be suitably used, it is preferably represented by the following formula (2).

In the above formula (2), R ₁ and / or R ₂ may have an oxyalkylene chain having 1 to 6 carbon atoms, and the alkylene group in the oxyalkylene chain may be linear or branched. The terminal of the oxyalkylene chain may be an alkoxy group or a hydroxyl group. Further, any _one of R _{1 and} R ₂ may be a hydroxyl group, or an alkyl group or an alkoxy group, and a functional group in which a part of the alkyl group or alkoxy group is substituted with a hetero atom It may be n is an integer of 1 to 300.

  As the organopolysiloxane, one having a site containing siloxane (siloxane site) as a main chain and an oxyalkylene chain bonded to the end of the main chain is used. By using the organosiloxane having the oxyalkylene chain, the compatibility with the (meth) acrylic polymer, the antistatic component and the like can be balanced, and it is presumed that light peeling is realized.

Moreover, as the organopolysiloxane in the present invention, for example, the following configuration can be used. 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 oxyethylene group Examples thereof include a propylene group and an oxybutylene group, and among them, an oxyethylene group and an oxypropylene group are preferable. When R ₁ and R ₂ both have an oxyalkylene chain, they may be the same or different.

  Further, 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, and among them, an alkoxy group is more preferable. When a separator is attached to the surface of the pressure-sensitive adhesive layer for the purpose of protecting the pressure-sensitive adhesive surface, an organopolysiloxane having hydroxyl groups at the end causes an interaction with the separator and adhesion (peeling) when peeling the separator from the surface of the pressure-sensitive adhesive layer The power may rise.

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

  As a specific example of the organopolysiloxane having an oxyalkylene chain in the main chain, for example, as a commercial product, the trade names X-22-4952, X-22-2427, X-22-6266, KF-6004, KF-889 (all manufactured by Shin-Etsu Chemical Co., Ltd.), BY16-201, SF8427 (all manufactured by Toray Dow Corning), IM22 (manufactured by Asahi Kasei Wacker), and the like. These compounds may be used alone or in combination of two or more.

なお、上記式（３）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。)Moreover, it is also possible to use an organosiloxane having an oxyalkylene chain in the side chain (binding) in addition to the organosiloxane having the oxyalkylene chain in the main chain described above (binding), and it is possible to use side chains rather than the main chain. It is a more preferable embodiment to use an organosiloxane having an oxyalkylene chain for As the organopolysiloxane, although a known organopolysiloxane having a polyoxyalkylene side chain can be suitably used, it is preferably represented by the following formula (3).

In the above formula (3), 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 of 0 to 1000. However, m and n can not be 0 simultaneously. a and b are integers of 0 to 100. However, a and b can not be 0 simultaneously. )

Moreover, as the organopolysiloxane in the present invention, for example, the following configuration can be used. Specifically, R ₁ in the formula is a monovalent group exemplified by an alkyl group such as methyl, ethyl and propyl, an aryl group such as phenyl and tolyl, or an aralkyl group such as benzyl and phenethyl. It is an organic group, and each may have a substituent such as a hydroxyl group. As R < ₂ >, R < ₃ > and R < ₄ >, C1-C8 alkylene groups, such as a methylene group, ethylene group, a propylene group, can be used. 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 or a propylene group in order to increase the concentration of an antistatic component (eg, an ionic group-containing silicone etc.) that can be dissolved in the polyoxyalkylene side chain. Is preferred. R ₅ may be a monovalent organic group exemplified by an alkyl group such as a methyl group, an ethyl group, a propyl group or an 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. In addition, the molecule may have a reactive substituent such as (meth) acryloyl group, allyl group or hydroxyl group. Among the organosiloxanes having a polyoxyalkylene side chain, an organosiloxane having a polyoxyalkylene side chain having a hydroxyl group end is presumed to be easy to achieve compatibility balance.

  As specific examples of organosiloxanes having an oxyalkylene chain in the side chain, for example, commercially available products under the trade 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-6011, KF-6012, KF-6015, KF-6017, X-22 -2516 (above, Shin-Etsu Chemical Co., Ltd. product) 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 da Corning Inc.), TSF-4440, TSF-4441, TSF-4445, TSF-4450, TSF-4446, TSF-4452, TSF-4460 (manufactured by Momentive Performance Materials), BYK-333, BYK-307, BYK -377, BYK-UV 3500, BYK-UV 3570 (manufactured by Big Chemie Japan), and the like. These compounds may be used alone or in combination of two or more.

  The organosiloxane used in the present invention preferably has an HLB (Hydrophile-Lipophile Balance) value of 1 to 16, and 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.

  The pressure-sensitive adhesive composition may contain an oxyalkylene group-containing compound which does not contain an organopolysiloxane. By containing the compound in the pressure-sensitive adhesive, it is possible to obtain a pressure-sensitive adhesive which is further excellent in wettability to an adherend.

  Specific examples of the oxyalkylene group-containing compound not containing the organopolysiloxane include, for example, polyoxyalkylene alkylamine, polyoxyalkylene diamine, polyoxyalkylene fatty acid ester, polyoxyalkylene sorbitan fatty acid ester, polyoxyalkylene alkyl phenyl ether And nonionic surfactants such as polyoxyalkylene alkyl ether, polyoxyalkylene alkyl allyl ether, polyoxyalkylene alkyl phenyl allyl ether; polyoxyalkylene alkyl ether sulfuric acid ester salt, polyoxyalkylene alkyl ether phosphoric acid ester salt, poly Oxyalkylene alkyl phenyl ether sulfate, polyoxyalkylene alkyl phenyl ether phosphoric acid ester Anionic surfactants such as salts; other, cationic surfactants having a polyoxyalkylene chain (polyalkylene oxide chain), amphoteric surfactants, polyether compounds having a polyoxyalkylene chain (and derivatives thereof And acrylic compounds (and their derivatives) having a polyoxyalkylene chain, and the like. Moreover, you may mix | blend a polyoxyalkylene chain containing monomer as a polyoxyalkylene chain containing compound. Such polyoxyalkylene chain-containing compounds may be used alone or in combination of two or more.

  Specific examples of the polyether compound (polyether component) having a polyoxyalkylene chain include a block copolymer of polypropylene glycol (PPG) -polyethylene glycol (PEG), a block copolymer of PPG-PEG-PPG, PEG-PPG-PEG block copolymers and the like can be mentioned. Examples of the derivative of the polyether compound having a polyoxyalkylene chain include an oxypropylene group-containing compound whose end is etherified (PPG monoalkyl ether, PEG-PPG monoalkyl ether, etc.), oxypropylene whose end is acetylated Group-containing compounds (terminally acetylated PPG etc.) and the like can be mentioned.

  Moreover, the (meth) acrylate polymer which has an oxyalkylene group is mentioned as a specific example of the acrylic compound which has the said polyoxyalkylene chain. The oxyalkylene group is preferably 1 to 50, more preferably 2 to 30, and still more preferably 2 to 20 from the viewpoint of coordination of the ionic group-containing silicone, as the addition mole number of the oxyalkylene unit. Further, the terminal of the oxyalkylene chain may be a hydroxyl group or may be substituted by an alkyl group, a phenyl group or the like.

  The (meth) acrylate polymer having an oxyalkylene group is preferably a polymer containing a (meth) acrylic acid alkylene oxide as a monomer unit (component), and a specific example of the (meth) acrylic acid alkylene oxide As an example, as ethylene glycol group-containing (meth) acrylate, for example, methoxy-polyethylene glycol (meth) acrylate type such as methoxy-diethylene glycol (meth) acrylate, methoxy-triethylene glycol (meth) acrylate, ethoxy-diethylene glycol ( Ethoxy-polyethylene glycol (meth) acrylate type, such as meta) acrylate, ethoxy-triethylene glycol (meth) acrylate, butoxy-diethylene glycol (meth) acrylate, Butoxy-polyethylene glycol (meth) acrylate type such as x-triethylene glycol (meth) acrylate, phenoxy-polyethylene glycol (meth) acrylate type such as phenoxy-diethylene glycol (meth) acrylate, phenoxy-triethylene glycol (meth) acrylate, Examples thereof include 2-ethylhexyl-polyethylene glycol (meth) acrylate, nonylphenol-polyethylene glycol (meth) acrylate type, and methoxy-polypropylene glycol (meth) acrylate type such as methoxy-dipropylene glycol (meth) acrylate.

  Moreover, other monomer units (components) other than the said (meth) acrylic acid alkylene oxide can also be used as said monomer unit (component). Specific examples of the other monomer components include 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, acrylates having an alkyl group of 1 to 14 carbon atoms such as n-tetradecyl (meth) acrylate and / or methacrylates And the like.

  Furthermore, as other monomer units (components) other than the (meth) acrylic acid alkylene oxide, carboxyl group-containing (meth) acrylate, phosphoric acid group-containing (meth) acrylate, cyano group-containing (meth) acrylate, vinyl esters , Aromatic vinyl compound, acid anhydride group-containing (meth) acrylate, hydroxyl group-containing (meth) acrylate, amide group-containing (meth) acrylate, amino group-containing (meth) acrylate, epoxy group-containing (meth) acrylate, N- It is also possible to appropriately use acryloyl morpholine, vinyl ethers and the like.

  In a more preferable embodiment, the polyoxyalkylene chain-containing compound not containing the organopolysiloxane is a compound having a (poly) ethylene oxide chain at least partially. By blending the (poly) ethylene oxide chain-containing compound, the compatibility between the base polymer and the antistatic component is improved, bleeding to the adherend is suitably suppressed, and a low-staining pressure-sensitive adhesive composition is obtained. Be Among them, when a PPG-PEG-PPG block copolymer is used, an adhesive excellent in low stain resistance can be obtained. As the polyethylene oxide chain-containing compound, the mass of the (poly) ethylene oxide chain occupying in the entire polyoxyalkylene chain-containing compound not containing the organopolysiloxane is preferably 5 to 90% by mass, more preferably 5 to 85 % By mass, more preferably 5 to 80% by mass, and most preferably 5 to 75% by mass.

  The molecular weight of the polyoxyalkylene chain-containing compound not containing the organopolysiloxane is suitably one having a number average molecular weight (Mn) of 50,000 or less, preferably 200 to 30,000, and more preferably 200 to 10,000, usually The thing of 200-5000 is used suitably. When Mn is more than 50,000, the compatibility with the acrylic polymer tends to be reduced, and the pressure-sensitive adhesive layer tends to be whitened. When Mn is less than 200, contamination with the polyoxyalkylene compound may be likely to occur. In addition, Mn means the value of polystyrene conversion obtained by GPC (gel permeation chromatography) here.

  Moreover, specific examples of the polyoxyalkylene chain-containing compound not containing the organopolysiloxane as commercial products include, for example, Adeka Pluronic 17R-4, Adeka Pluronic 25 R-2 (all of which are made by ADEKA), Latemul PD- 420, Latem PD-420, Latem PD-450, Emulgen 120 (manufactured by Kao Corporation), Aqualon HS-10, KH-10, Neugen EA-87, EA-137, EA-157, EA-167, EA-177 ( As mentioned above, Dai-ichi Kogyo Seiyaku Co., Ltd. product etc. are mentioned.

  As content of the said oxyalkylene group containing compound, 100 mass parts of adhesive polymers (It is a main polymer, for example, a (meth) acrylic-type polymer, a urethane type polymer, a silicone type polymer etc.) which comprises the said adhesive composition The amount is preferably 0.01 to 5.0 parts by mass, more preferably 0.02 to 2 parts by mass, still more preferably 0.03 to 1.6 parts by mass, and most preferably 0.1 to 0. 8 parts by mass. It is preferable for the pressure-sensitive adhesive sheet of the present invention to have both the antistatic property and the light releasability (re-peelability) when the content is within the above range.

<Crosslinking agent>
In the pressure-sensitive adhesive sheet (surface protective film) of the present invention, the pressure-sensitive adhesive composition preferably contains a crosslinking agent. In the present invention, the pressure-sensitive adhesive layer can be formed using the pressure-sensitive adhesive composition. For example, in the case where the pressure-sensitive adhesive composition is an acrylic pressure-sensitive adhesive containing the (meth) acrylic polymer, the constituent units of the (meth) acrylic polymer, the composition ratio, the selection and addition ratio of the crosslinking agent, etc. By adjusting and crosslinking, a pressure-sensitive adhesive sheet (pressure-sensitive adhesive layer) more excellent in 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, and in particular, the use of the isocyanate compound is a preferred embodiment. These compounds may be used alone or in combination of two or more.

  Examples of the isocyanate compound include aliphatic polyisocyanates such as trimethylene diisocyanate, butylene diisocyanate, hexamethylene diisocyanate (HDI), dimer acid diisocyanate, etc., cyclopentylene diisocyanate, cyclohexylene diisocyanate, isophorone diisocyanate (IPDI), 1, Alicyclic isocyanates such as 3-bis (isocyanatomethyl) cyclohexane; aromatic isocyanates such as 2,4-tolylene diisocyanate; 4,4'-diphenylmethane diisocyanate; xylylene diisocyanate (XDI); Allophanate bond, biuret bond, isocyanurate bond, uretdione bond, urea bond, carbodiimide bond, Reton'imin bond, polyisocynate modified products thereof obtained by modifying the like oxadiazinetrione bond. For example, commercially available products include Takenate 300S, Takenate 500, Takenate 600, Takenate D 165 N, Takenate D 178 N (all manufactured by Takeda Yakuhin Kogyo Co., Ltd.), Sumidule T80, Sumidul L, Desmodur N 3400 (all, Sumika Bayer Urethane) Manufactured products by Co., Ltd., Millionate MR, Millionate MT, Coronate L, Coronate HL, Coronate HX (manufactured by Nippon Polyurethane Industry Co., Ltd.) and the like. These isocyanate compounds may be used alone or in combination of two or more. It is also possible to use a bifunctional isocyanate compound and a trifunctional or higher isocyanate compound in combination. By using a crosslinking agent in combination, it is possible to achieve both adhesiveness and repulsion resistance (adhesion to a curved surface), and a pressure-sensitive adhesive sheet with more excellent adhesion reliability can be obtained.

  When the isocyanate compound (a bifunctional isocyanate compound and a trifunctional or higher isocyanate compound) is used in combination, the compounding ratio (mass ratio) of both compounds is [bifunctional isocyanate compound] / [3 It is preferable that it is mix | blended by 0.1 / 99.9-50/50, and, as for the isocyanate compound of functional or more than 0.1 / 99.9-50/50, 0.1 / 99.9-20/80 are more preferable, 0.1 / 99 More preferably, 9/10 to 10/90, more preferably 0.1 / 99.9 to 5/95, and most preferably 0.1 / 99.9 to 1/99. By adjusting in the said range and mix | blending, it becomes an adhesive layer excellent in adhesiveness and repulsion resistance, and becomes a preferable aspect.

  Examples of the epoxy compound include N, N, N ′, N′-tetraglycidyl-m-xylenediamine (trade name: TETRAD-X, manufactured by Mitsubishi Gas Chemical Co., Ltd.) and 1,3-bis (N, N-di). Glycidyl aminomethyl) cyclohexane (trade name: TETRAD-C, manufactured by Mitsubishi Gas Chemical Co., Ltd.) and the like.

  Examples of the melamine resin include hexamethylolmelamine. Examples of the aziridine derivative include commercially available HDU, TAZM, TAZO (manufactured by Mutual Pharmaceutical Co., Ltd.) and the like as commercial products.

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

  The content of the crosslinking agent used in the present invention is, for example, preferably 0.01 to 20 parts by mass, and 0.1 to 15 parts by mass with respect to 100 parts by mass of the (meth) acrylic polymer. The content is more preferably 0.5 to 10 parts by mass, and most preferably 1 to 6 parts by mass. When the content is less than 0.01 parts by mass, the crosslinking formation by the crosslinking agent may be insufficient, the cohesive force of the obtained pressure-sensitive adhesive layer may be reduced, and sufficient heat resistance may not be obtained. It tends to cause adhesive residue. On the other hand, when the content exceeds 20 parts by mass, the cohesion of the polymer is large, the fluidity is reduced, and the wetting to the adherend (for example, the polarizing plate) becomes insufficient, and the adherend and the adhesive It tends to be a cause of the swelling generated between the layer (pressure-sensitive adhesive composition layer). Furthermore, when the amount of the crosslinking agent is large, the peeling chargeability 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 crosslinking catalyst for more effectively promoting any of the above-mentioned crosslinking reactions. As such a crosslinking catalyst, for example, tin-based catalysts such as dibutyltin dilaurate and dioctyltin dilaurate, tris (acetylacetonato) iron, tris (hexane-2,4-dionato) iron, tris (heptane-2,4-dionato) ) Iron, Tris (heptane-3,5-dionato) iron, Tris (5-methylhexane-2,4-dionato) iron, Tris (octane-2,4-dionato) iron, Tris (6-methylheptane-2) (4,4-Dionato) iron, tris (2,6-dimethylheptane-3,5-dionato) iron, tris (nonane-2,4-dionato) iron, tris (nonane-4,6-dionato) iron, tris ( 2,2,6,6-Tetramethylheptane-3,5-dionato) iron, tris (tridecane-6,8-dionato) iron, tris (1-phenylbutane-1), -Dionato) iron, tris (hexafluoroacetylacetonato) iron, tris (ethyl acetoacetate) iron, tris (acetoacetic acid-n-propyl) iron, tris (isopropyl acetoacetate) iron, tris (acetoacetic acid-n-butyl) ) Iron, tris (acetoacetic acid-sec-butyl) iron, tris (acetoacetic acid-tert-butyl) iron, tris (propionyl methyl acetate) iron, tris (propionyl ethyl acetate) iron, tris (propionyl acetic acid-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 of the crosslinking catalyst is not particularly limited, but preferably about 0.0001 to 1 parts by mass with respect to 100 parts by mass of the (meth) acrylic polymer, for example, 0.001 to 0.5 The parts by mass are more preferred. When the pressure-sensitive adhesive layer is formed within the above range, the rate of the crosslinking reaction is fast, and the pot life of the pressure-sensitive adhesive composition is extended, which is a preferable embodiment.

  Furthermore, the pressure-sensitive adhesive composition can contain a compound that produces keto-enol tautomerism. For example, in a pressure-sensitive adhesive composition containing a crosslinking agent or in a pressure-sensitive adhesive composition that can be used in combination with a crosslinking agent, an embodiment including a compound that produces the keto-enol tautomerism can be preferably employed. Thereby, the excessive viscosity rise and gelatinization of the adhesive composition after mix | blending a crosslinking agent can be suppressed, and the effect of extending the pot life of an adhesive composition may be implement | achieved. When at least an isocyanate compound is used as the crosslinker, it is particularly significant to include a compound that produces keto-enol tautomerism. This technique can be preferably applied, for example, when the pressure-sensitive adhesive composition is in the form of an organic solvent solution or no solvent.

  As a compound which produces the said keto- enol tautomerism, various (beta) -dicarbonyl compounds can be used. Specific examples thereof include acetylacetone, 2,4-hexanedione, 3,5-heptanedione, 2-methylhexane-3,5-dione, 6-methylheptane-2,4-dione, 2,6-dimethylheptane-. Β-diketones such as 3,5-dione; acetoacetic acid esters such as methyl acetoacetate, ethyl acetoacetate, isopropyl acetoacetate, tert-butyl acetoacetate; ethyl propionyl acetate, ethyl propionyl acetate, isopropyl propionyl acetate, propionyl acetate Propionyl acetates such as tert-butyl; isobutyryl acetates such as ethyl isobutyryl acetate, ethyl isobutyryl acetate, isopropyl isobutyryl acetate, tert-butyl isobutyryl acetate; malonic esters such as methyl malonate and ethyl malonate; And the like. Among them, preferred compounds include acetylacetone and acetoacetic acid esters. The compounds that produce such keto-enol tautomerism may be used alone or in combination of two or more.

  The content of the compound that produces the keto-enol tautomerism can be, for example, 0.1 to 20 parts by mass with respect to 100 parts by mass of the (meth) acrylic polymer, and is usually 0.5 to 15 It is appropriate to use parts by mass (for example, 1 to 10 parts by mass). When the amount of the compound is too small, it may be difficult to exhibit a sufficient use effect. On the other hand, if the compound is used more than necessary, it may remain in the pressure-sensitive adhesive layer and reduce the cohesion.

  Furthermore, the pressure-sensitive adhesive composition may contain other known additives, for example, lubricants, colorants, powders such as pigments, plasticizers, tackifiers, low molecular weight polymers, surface lubrication Agents, leveling agents, antioxidants, corrosion inhibitors, light stabilizers, UV absorbers, polymerization inhibitors, silane coupling agents, inorganic or organic fillers, metal powders, particles, foils, etc. It can add suitably according to the use to be carried out.

<Pressure-sensitive adhesive layer and pressure-sensitive adhesive sheet (surface protection film)>
The pressure-sensitive adhesive sheet of the present invention is formed by forming the pressure-sensitive adhesive layer on at least one surface of a substrate film, and in this case, 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 comprising the pressure-sensitive adhesive composition after crosslinking to a substrate film or the like.

  Moreover, although the method in particular of forming an adhesive layer on a base film is not ask | required, for example, the said adhesive composition (solution) is apply | coated to a base film, the polymerization solvent etc. are removed by drying, and an adhesive layer is It is produced by forming on a base film. Thereafter, curing may be performed for the purpose of adjusting the component transfer of the pressure-sensitive adhesive layer, adjusting the crosslinking reaction, and the like. Moreover, when apply | coating an adhesive composition on a base film and producing an adhesive sheet, 1 or more solvent other than a polymerization solvent in the said adhesive composition so that it can apply | coat uniformly on a base film May be added anew.

  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 thereof include roll coating, gravure coating, reverse coating, roll brushing, spray coating, air knife coating, and extrusion coating using a die coater.

  The pressure-sensitive adhesive sheet of the present invention is usually produced such that the thickness of the pressure-sensitive adhesive layer is about 3 to 100 μm, preferably about 5 to 50 μm. It is preferable that the thickness of the pressure-sensitive adhesive layer is in the above-mentioned range, because it is easy to obtain an appropriate balance of removability and adhesiveness.

  The total thickness of the pressure-sensitive adhesive sheet of the present invention is preferably 8 to 300 μm, more preferably 10 to 200 μm, and most preferably 20 to 100 μm. It is excellent in adhesive property (removability, adhesiveness etc.), workability | operativity, an appearance characteristic as it is in the said range, and it becomes a preferable aspect. In addition, the said total thickness means the sum total of the thickness containing all the layers, such as a base film, an adhesive layer, and another layer.

<Separator>
In the pressure-sensitive adhesive sheet of the present invention, a separator is preferably attached to the side of the pressure-sensitive adhesive layer opposite to the side in contact with the base film. The said separator can bond a separator together on the adhesive layer surface in order to protect an adhesive surface as needed.

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

  The thickness of the separator is generally 5 to 200 μm, preferably about 10 to 100 μm. When it is in the above-mentioned range, it is preferable because the bonding workability to the pressure-sensitive adhesive layer and the peeling workability from the pressure-sensitive adhesive layer are excellent. The separator may be, if necessary, a release agent of silicone type, fluorine type, long chain alkyl type or fatty acid amide type, release by silica powder etc., antifouling treatment, coating type, kneading type, evaporation type Etc. can also be performed.

  In the pressure-sensitive adhesive sheet of the present invention, the ionic group-containing silicone is preferably present (applied) on the surface of the separator in contact with the pressure-sensitive adhesive layer (see FIG. 1). When the separator is attached to the pressure-sensitive adhesive layer by the presence of the ionic group-containing silicone (a coated, coated film is formed) on the surface of the separator in contact with the pressure-sensitive adhesive layer Under the high temperature environment, the ionic group-containing silicone is transferred (transferred) to the surface of the pressure-sensitive adhesive layer from the surface of the separator and the pressure-sensitive adhesive layer is attached to the surface of an adherend (for example, a polarizing plate). Even when stored, the above-mentioned ionic group-containing silicone does not penetrate into the adherend (from the adherend surface to the inside of the adherend), the peeling charge characteristics become stable even with time, and the antistatic performance over a long period of time Is a preferred embodiment.

<Optical member>
It is preferable that the optical member of this invention is stuck (protected) by the said adhesive sheet. Since the pressure-sensitive adhesive sheet is excellent in the antistatic property and the temporal stability of release voltage, it can be used for surface protection application (surface protection film) at the time of processing, transportation, shipping etc. It will be useful to protect the surface. In particular, since it can be used for plastic products and the like in which static electricity is easily generated, it becomes very useful in antistatic applications in the technical fields related to optical and electronic parts where charging becomes a particularly serious problem.

  In the following, some examples relating to the present invention will be described, but it is not intended to limit the present invention to those shown in such specific examples. In the following description, “parts” and “%” are based on mass unless otherwise noted. Moreover, the compounding quantity (addition amount) in a table | surface was shown.

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

<Measurement of Weight Average Molecular Weight (Mw)>
The weight average molecular weight (Mw) was measured using Tosoh Corp. GPC apparatus (HLC-8220GPC). The measurement conditions are as follows.
Sample concentration: 0.2 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 (one) + TSKgel SuperHZM-H (two)
Reference column; TSKgel SuperH-RC (one)
Detector: Differential Refractometer (RI)
The weight average molecular weight was determined by polystyrene conversion value.

<Measurement of initial peeling voltage>
The adhesive sheet according to each example is cut to a size of 70 mm in width and 130 mm in length, and after peeling off the release liner, a polarizing plate (manufactured by Nitto Denko Corporation, SEG 1423 DU polarizing plate, width: 70 mm, length) The other end of the pressure-sensitive adhesive sheet was pressed onto the surface of 100 mm) with a hand roller such that 30 mm of the end of the pressure-sensitive adhesive sheet extended from the end of the polarizing plate.
The sample was left to stand in an environment of 23 ° C. × 50% RH for one day, and as shown in FIG. The end of the pressure-sensitive adhesive sheet (surface protective film) 1 protruding 30 mm from the polarizing plate 20 was fixed to an automatic winder (not shown), and peeled off so as to have a peeling angle of 150 ° and a peeling speed of 30 m / min. A potential measuring device 40 (type “STATIRON DZ-4”, manufactured by Shishido Electrostatic Co., Ltd.) in which the potential of the surface of the adherend (polarizing plate) generated at this time is fixed at a height of 30 mm from the center of polarizing plate 20 The "initial peeling voltage" was measured. The measurement was performed under the environment of 23 ° C. and 50% RH.

<Measurement of 70 ° C. storage stripping voltage>
The adhesive sheet according to each example is cut to a size of 70 mm in width and 130 mm in length, and after peeling off the release liner, a polarizing plate (manufactured by Nitto Denko Corporation, SEG 1423 DU polarizing plate, width: 70 mm, length) The other end of the pressure-sensitive adhesive sheet was pressed onto the surface of 100 mm) with a hand roller such that 30 mm of the end of the pressure-sensitive adhesive sheet extended from the end of the polarizing plate.
The sample was left to stand in an environment of 70 ° C. for 120 hours, and then set in a predetermined position on a sample fixing stand 30 having a height of 20 mm as shown in FIG. The end of the pressure-sensitive adhesive sheet (surface protective film) 1 protruding 30 mm from the polarizing plate 20 was fixed to an automatic winder (not shown), and peeled off so as to have a peeling angle of 150 ° and a peeling speed of 30 m / min. A potential measuring device 40 (type “STATIRON DZ-4”, manufactured by Shishido Electrostatic Co., Ltd.) in which the potential of the surface of the adherend (polarizing plate) generated at this time is fixed at a height of 30 mm from the center of polarizing plate 20 In the above, “70 ° C. storage peeling voltage” was measured. The measurement was performed under the environment of 23 ° C. and 50% RH.

  The initial peeling zone voltage and the 70 ° C. storage peeling zone voltage (kV) (absolute value) in the present invention are preferably 0.55 or less, more preferably 0.5 or less, and further preferably Preferably, it is 0.45 or less. When in the above range, the adhesive sheet peeled off after initial storage at 70 ° C. for 120 hours is not charged, and is excellent in antistatic properties and peeling electrification characteristics with time, and further excellent in workability, which is a preferred embodiment. .

<Presence of contamination (contamination resistance)>
The pressure-sensitive adhesive sheet according to each example is cut to a size of 50 mm in width and 80 mm in length, and the separator is peeled off, and then air bubbles are applied to a TAC polarizing plate (manufactured by Nitto Denko, SEG 1423 DU polarizing plate, width: 70 mm, length: 100 mm) It pressure-bonded with the hand roller, inserting, and the evaluation sample was produced. After the evaluation sample was left to stand in an environment of 70 ° C. for 120 hours, the pressure-sensitive adhesive sheet was peeled off from the adherend by hand, and the air bubble marks on the adherend surface at that time were visually observed. In the evaluation, the case where no bubble mark was observed was evaluated as ○, and the case where a bubble mark was observed was evaluated as x.

Preparation of Acrylic Polymer (1)
96 parts by mass of 2-ethylhexyl acrylate (2EHA), 4 parts by mass of 2-hydroxyethyl acrylate (HEA), 2 as a polymerization initiator in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction pipe, and a cooler 0.2 parts by mass of 2,2'-azobisisobutyronitrile and 150 parts by mass of ethyl acetate are charged, nitrogen gas is introduced while gently stirring, and the liquid temperature in the flask is maintained at around 65 ° C., and polymerization is carried out for 6 hours The reaction was carried out to prepare an acrylic polymer (1) solution (40% by mass). The weight average molecular weight (Mw) of the acrylic polymer (1) was 540,000.

Preparation of Acrylic Polymer (2)
91 parts by mass of 2-ethylhexyl acrylate (2EHA), 9 parts by mass of 4-hydroxybutyl acrylate (4HBA), acrylic acid (AA) in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction pipe, and a cooler Charge 0.02 parts by mass, 0.2 parts by mass of 2,2'-azobisisobutyro nitrile as a polymerization initiator, 150 parts by mass of ethyl acetate, introduce nitrogen gas while gently stirring, and introduce liquid in the flask The temperature was kept at around 65 ° C. and polymerization reaction was carried out for 6 hours to prepare an acrylic polymer (2) solution (40% by mass). The weight average molecular weight (Mw) of the acrylic polymer (2) was 540,000.

Example 1
[Preparation of Acrylic Adhesive Solution]
The above acrylic polymer (1) solution (40% by mass) is diluted to 20% by mass with ethyl acetate, and 500 parts by mass of this solution (100 parts by mass of solid content) is an ionic group-containing silicone (X-40-2450, 5 parts by mass (solid content: 0.5 parts by mass) of Shin-Etsu Chemical Co., Ltd. diluted to 10% with ethyl acetate, isocyanurate of hexamethylene diisocyanate which is a trifunctional isocyanate compound as a crosslinking agent (manufactured by Tosoh Corporation) Add 2 parts by mass of Coronate HX) (solid content: 2 parts by mass) and 3 parts by mass of dibutyltin dilaurate (1% by mass ethyl acetate solution) as a crosslinking catalyst (solid content: 0.03 parts by mass); An acrylic pressure-sensitive adhesive solution was prepared.

[Production of antistatic film]
Antistatic agent (Antisorbent (Solvex, Microsolver RMd-142, mainly composed of tin oxide and polyester resin)) 10 parts by mass diluted with a mixed solvent consisting of 30 parts by mass of water and 70 parts by mass of methanol An agent solution was prepared.
The resulting antistatic agent solution is coated on a polyethylene terephthalate (PET) film (thickness: 38 μm) using a Mayer bar, and dried at 130 ° C. for 1 minute to remove the solvent and remove the solvent (thick). To form an antistatic treated film.

[Production of adhesive sheet (surface protection film)]
The above-mentioned acrylic pressure-sensitive adhesive solution was applied to the side opposite to the antistatic treatment side of the above-mentioned antistatic treatment film, and heated at 130 ° C. for 2 minutes to form a pressure-sensitive adhesive layer with a thickness of 15 μm. Then, a silicone-treated surface of a polyethylene terephthalate film (25 μm in thickness), one side of which was subjected to silicone treatment, was attached to the surface of the pressure-sensitive adhesive layer to prepare a pressure-sensitive adhesive sheet.

Example 2
Instead of the acrylic polymer (1) used in Example 1, an acrylic polymer (2) is used, and in place of the ionic group-containing silicone X-40-2450, an ionic group-containing silicone X-40-2750 A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except for using.

Example 3
Instead of the acrylic polymer (1) used in Example 1, an acrylic polymer (2) was used, and 0.5 parts by mass of an oxyalkylene group-containing compound KF 353 (manufactured by Shin-Etsu Chemical Co., Ltd.) containing an organopolysiloxane was further added. Then, in the same manner as in Example 1, a pressure-sensitive adhesive sheet was produced.

Example 4
Latemul PD-420 (manufactured by Kao Corporation) 0.2, which is an oxyalkylene group-containing compound not containing an organopolysiloxane, using an acrylic polymer (2) instead of the acrylic polymer (1) used in Example 1 An adhesive sheet was produced in the same manner as in Example 1 with the addition of parts by mass.

Examples 5 to 7
In the same manner as in Example 1, using acrylic polymer (2) instead of acrylic polymer (1) used in Example 1, and using the amount of X-40-2450 described in the table, An adhesive sheet was produced.

Example 8
[Preparation of Urethane-Based Pressure-Sensitive Adhesive Solution]
85 parts by mass of Preminor S3011 (Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having 3 hydroxyl groups, and Sannix GP3000 (a Sanyo Chemical Industries Co., Ltd., Mn = 3000), which is a polyol having 3 hydroxyl groups 2 parts by mass, Sannix GP 1000 (manufactured by Sanyo Chemical Industries, Ltd., Mn = 1000) which is a polyol having 3 hydroxyl groups, 18 parts by mass of isocyanate compound (Coronato HX: C / HX, manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent As a catalyst, 0.04 parts by mass of iron (III) acetylacetonate (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.5 parts by mass of ionic group-containing silicone X-40-2450 (manufactured by Shin-Etsu Chemical Co., Ltd.), as a dilution solvent 210 parts by mass of ethyl acetate was blended to obtain a urethane-based pressure-sensitive adhesive solution. Then, in the same manner as in Example 1, a pressure-sensitive adhesive sheet was prepared in which the heating conditions and the like and the thickness of the obtained pressure-sensitive adhesive layer were adjusted.

Example 9
[Preparation of silicone pressure sensitive adhesive solution]
100 parts by mass of solid content of “X-40-3229” (solid content 60 mass%, manufactured by Shin-Etsu Chemical Co., Ltd.) as a silicone-based adhesive, “CAT-PL-50T” (Shin-Etsu Chemical Co., Ltd.) as a platinum catalyst 0.5 parts by mass, 0.5 parts by mass of ionic group-containing silicone X-40-2450 (manufactured by Shin-Etsu Chemical Co., Ltd.), and 100 parts by mass of toluene as a solvent to obtain a silicone-based pressure-sensitive adhesive solution . Then, in the same manner as in Example 1, a pressure-sensitive adhesive sheet was prepared in which the heating conditions and the like and the thickness of the obtained pressure-sensitive adhesive layer were adjusted.

<Comparative Examples 1 to 4>
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 2 except that the ionic compound described in Table 1 was used instead of the ionic group-containing silicone used in Example 2.

Comparative Example 5
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 3 except that EMIFSI was used instead of the ionic group-containing silicone used in Example 3.

  About the adhesive sheet which concerns on an Example and a comparative example, the compounding content mentioned above, the result of having performed various measurements, and evaluation were shown in Table 1. Also, the abbreviations in Table 1 will be described below.

[Oxyalkylene Group-Containing Compound]
KF 353: an organopolysiloxane having an oxyalkylene chain (HLB value: 10), manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KF-353
PD420: Oxyalkylene group-containing compound not containing organopolysiloxane (HLB value: 12.6), manufactured by Kao Corporation, trade name: Latem PD-420

[Ionic Compound (Antistatic Component)]
X-40-2450: silicone containing an ionic group, manufactured by Shin-Etsu Chemical Co., Ltd., 55% active ingredient
X-40-2750: Silicone containing an ionic group, Shin-Etsu Chemical Co., Ltd., 100% active ingredient
LiTFSI: Lithium bis (trifluoromethanesulfonyl) imide, alkali metal salt, Tokyo Chemical Industry Co., Ltd., 100% active ingredient
EMIFSI: 1-ethyl-3-methylimidazolium bis (fluorosulfonyl) imide, ionic liquid, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., 100% active ingredient
BMPTFSI: 1-butyl-3-methylpyridinium bis (trifluoromethanesulfonyl) imide, ionic liquid, manufactured by Aldrich, 100% active ingredient
MTOATFSI: methyltrioctylammonium bis (trifluoromethanesulfonyl) imide, manufactured by Wako Pure Chemical Industries, 100% active ingredient

  From Table 1, in all the Examples, it has confirmed that it was excellent in the time-lapse stability of antistatic property and the peeling charge voltage. Moreover, when the compounding quantity of ionic group containing silicone was adjusted to the desired range and it mix | blended, it has confirmed that it was excellent also in contamination resistance (low contamination property).

  On the other hand, according to Table 1, in all the comparative examples, since an antistatic agent such as an ionic liquid is used instead of the ionic group-containing silicone, the antistatic property and the aging stability of the peeling voltage are compared with the examples. It was confirmed to be inferior. In particular, since no ionic group-containing silicone was used, a large increase in peel voltage with time was observed, and the ionic compound contained in the pressure-sensitive adhesive layer penetrated the polarizing plate surface with time. It is inferred.

  The pressure-sensitive adhesive sheet disclosed herein protects the optical member during the production, transport, etc. of the optical member used as a component of a liquid crystal display panel, plasma display panel (PDP), organic electroluminescence (EL) display, etc. It is suitable as a surface protection film for In particular, a surface protection film applied to optical members such as a polarizing plate (polarizing film), a wave plate, a retardation plate, an optical compensation film, a brightness enhancement film, a light diffusion sheet, a reflection sheet for liquid crystal display panels It is useful as a protective film).

1: Adhesive sheet (surface protection film)
1 ': Adhesive sheet with separator (surface protection film)
10: Acrylic plate 11: Separator 12: Silicone coating film containing ionic group 13: Adhesive layer 14: Substrate film 20: Polarizing plate 30: Sample fixing base 40: Potential measuring device

Claims (7)

An adhesive composition comprising an adhesive polymer and an ionic group-containing silicone represented by the following formula (1).

(R _{1 to} R ₄ may be the same or different, and include any of an alkyl group having 1 to 10 carbon atoms, an alkoxy group, an aryl group, an aliphatic group, a fluorine-substituted alkyl group, and an ionic group, One or more of R _{1 to} R ₄ contain an ionic group, and n is an integer of 0 to 100.)   The pressure-sensitive adhesive composition according to claim 1, containing an oxyalkylene group-containing compound.   The pressure-sensitive adhesive composition according to claim 1 or 2, comprising at least one selected from the group consisting of an acrylic pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, and a silicone-based pressure-sensitive adhesive. A pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition according to any one of claims 1 to 3 on at least one side of a substrate film,
The pressure-sensitive adhesive sheet, wherein the ionic group-containing silicone is present in the inside and / or the surface of the pressure-sensitive adhesive layer.   The pressure-sensitive adhesive sheet according to claim 4, wherein a separator is attached to the side of the pressure-sensitive adhesive layer opposite to the side in contact with the base film.   The pressure-sensitive adhesive sheet according to claim 5, wherein the ionic group-containing silicone is present on the surface of the separator in contact with the pressure-sensitive adhesive layer. An optical member comprising a pressure-sensitive adhesive sheet according to claim 4 or a pressure-sensitive adhesive sheet obtained by peeling the separator from the pressure-sensitive adhesive sheet according to claim 5 or 6.

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