JP6905502B2 - Adhesive sheet and optical member - Google Patents

Description

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

The adhesive sheet of the present invention is used as a surface protective film used for the purpose of protecting the surface of an optical member such as a polarizing plate, a wave plate, a retardation plate, an optical compensation film, a reflective sheet, and a brightness improving film used in a liquid crystal display or the like. It is useful.

In recent years, when transporting optical components and electronic components or mounting them on a printed circuit board, the individual components are transported in a state of being wrapped in a predetermined sheet or in a state of having an adhesive tape attached. Among them, the surface protective film is particularly widely used in the field of optical and electronic components.

The surface protective film is generally attached to an adherend (protected body) via an adhesive applied to the support film side, and is used for the purpose of preventing scratches and stains that occur during processing and transportation of the adherend. (Patent Document 1). For example, a panel of a liquid crystal display is formed by bonding optical members such as a polarizing plate and a wave plate to a liquid crystal cell via an adhesive. A surface protective film is attached to these optical members via an adhesive to prevent scratches and stains that occur during processing and transportation of the adherend. Then, the surface protective film is peeled off and removed when it is no longer needed.

Further, when the surface protective film is peeled off from the adherend after aging treatment (preservation) during processing or transportation, the surface protective film and the optical member are generally made of a plastic material, so that they have high electrical insulation. Static electricity is generated during friction and peeling. In particular, after aged treatment (preservation) at a high temperature, the amount of antistatic agent present (transferred) on the surface of the adherend is reduced due to the permeation of the antistatic agent into the adherend, and the surface protective film is adhered. When peeling from the body (polarizing plate, etc.), an increase in the peeling band voltage is observed compared to immediately after bonding, the peeling charge stability is inferior, and the surface protective film is peeled off from the adherend (polarizing plate, etc.). At that time, static electricity is generated, and if a voltage is applied to the liquid crystal with the generated static electricity remaining, the orientation of the liquid crystal molecules may be lost and panel defects may occur.

Japanese Unexamined Patent Publication No. 9-165460

Therefore, an object of the present invention is to provide an adhesive sheet having excellent peeling charge stability even after storage over time at a high temperature in order to solve the problems of the conventional adhesive sheet.

That is, the pressure-sensitive adhesive sheet of the present invention is a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition on one or both sides of a support film, and the pressure-sensitive adhesive surface of the pressure-sensitive adhesive layer is placed on the TAC surface at 70 ° C. for one week. The peeling band voltage at a peeling speed of 30 m / min after sticking is less than 0.5 kV (absolute value).

In the pressure-sensitive adhesive sheet of the present invention, it is preferable that the pressure-sensitive adhesive composition contains a compound having an oxyalkylene chain and an ionic compound having an organic cation that is solid at room temperature (25 ° C.).

In the pressure-sensitive adhesive sheet of the present invention, the compound having an oxyalkylene chain is preferably an organopolysiloxane having an oxyalkylene chain.

In the pressure-sensitive adhesive sheet of the present invention, it is preferable that the pressure-sensitive adhesive composition contains a hydroxyl group and a (meth) acrylic polymer having a carboxyl group.

The pressure-sensitive adhesive sheet of the present invention has an antistatic layer on one side of the support film opposite to the pressure-sensitive adhesive layer, and the antistatic layer contains polyaniline sulfonic acid as a conductive polymer component, polyester resin as a binder, and , It is preferably formed from an antistatic agent composition containing an isocyanate-based cross-linking agent as a cross-linking agent.

In the pressure-sensitive adhesive sheet of the present invention, it is preferable that the antistatic agent composition further contains a fatty acid amide as a lubricant.

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

The adhesive sheet of the present invention is attached to an adherend and is used when the adhesive sheet is peeled off from the adherend even when it is exposed to a high temperature during processing (manufacturing) or transportation. The peeling band voltage can be suppressed to a low level, and the peeling charge stability after storage over time at high temperature is excellent, which is useful.

Schematic diagram of potential measuring unit

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

<Overall structure of adhesive sheet (surface protection film)>
The adhesive sheet (surface protective film) of the present invention is generally in the form of an adhesive sheet, an adhesive tape, an adhesive label, an adhesive film, or the like, and in particular, an optical component (for example, a liquid crystal display such as a polarizing plate or a wave plate). It is suitable as a surface protective film that protects the surface of an optical component during processing or transportation of an optical component (optical component used as a component of a display panel). The pressure-sensitive adhesive layer in the pressure-sensitive adhesive sheet is typically formed continuously, but is not limited to such a form, and the pressure-sensitive adhesive is formed in a regular or random pattern such as a dot shape or a stripe shape. It may be an agent layer. Further, the pressure-sensitive adhesive sheet disclosed herein may be in the form of a roll or in the form of a single leaf.

As a typical configuration example of the pressure-sensitive adhesive sheet (surface protective film) disclosed herein, a support film (base material) having an pressure-sensitive adhesive layer on one side or both sides, or an antistatic film provided on one side of the support film. Examples thereof include a layer and an adhesive layer provided on a surface opposite to the antistatic layer of the base support film. The pressure-sensitive adhesive sheet is used by attaching the pressure-sensitive adhesive layer to an adherend (protective object, for example, the surface of an optical component such as a polarizing plate). The adhesive sheet before use (that is, before being attached to the adherend) is protected by a release liner in which the surface of the adhesive layer (the surface to be attached to the adherend) is at least the adhesive layer side is the peeling surface. It may be in the same form. Alternatively, the pressure-sensitive adhesive sheet may be wound in a roll shape so that the pressure-sensitive adhesive layer comes into contact with the back surface of the support film (the surface of the antistatic layer) and the surface thereof is protected.

<Support film>
The pressure-sensitive adhesive sheet of the present invention is characterized by having a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition on one side or both sides of the support film. The resin material constituting the support film can be used without particular limitation, and for example, transparency, mechanical strength, thermal stability, moisture shielding property, isotropic property, flexibility, dimensional stability and the like can be used. It is preferable to use one having excellent characteristics. In particular, since the support film has flexibility, the pressure-sensitive adhesive composition can be applied by a roll coater or the like, and the adhesive composition can be wound into a roll shape, which is useful.

As the support film (base material), for example, 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-based polymers; poly A plastic film composed of a resin material containing an acrylic polymer such as methyl methacrylate; or the like as a main resin component (a main component among the resin components, typically a component accounting for 50% by mass or more) is used as the support film. It can be preferably used. Other examples of the resin material include styrene-based polymers such as polystyrene and acrylonitrile-styrene copolymers; olefin-based polymers such as polyethylene, polypropylene, polyolefins having a cyclic or norbornene structure, and ethylene-propylene copolymers; Examples thereof include those using a vinyl chloride polymer; an amide polymer such as nylon 6, nylon 6, 6, and aromatic polyamide; and the like as a resin material. Still other examples of the resin material include imide-based polymers, sulfone-based polymers, polyether sulfone-based polymers, polyether ether ketone-based polymers, polyphenylene sulfide-based polymers, vinyl alcohol-based polymers, vinylidene chloride-based polymers, and vinyl butyral-based polymers. , Arilate-based polymer, polyoxymethylene-based polymer, epoxy-based polymer and the like. It may be a support film composed of two or more blends of the above-mentioned polymers.

As the support film, a plastic film made of a transparent thermoplastic resin material can be preferably adopted. Among the plastic films, it is more preferable 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), and polybutylene terephthalate. say. Such a polyester film has preferable properties as a support film for an adhesive sheet, such as excellent optical properties and dimensional stability, but has a property of being easily charged as it is.

If necessary, the resin material constituting the support film may contain various additives such as an antioxidant, an ultraviolet absorber, a plasticizer, and a colorant (pigment, dye, etc.). Known or commonly used, for example, corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, application of an undercoating agent, etc. Surface treatment may be applied. Such a surface treatment may be, for example, a treatment for enhancing the adhesion between the support film and the antistatic layer. A surface treatment that introduces a polar group such as a hydroxyl group (−OH group) into the surface of the support film can be preferably adopted. Further, the second surface of the support film (the surface on the side where the adhesive layer is formed) may be subjected to the same surface treatment as described above. Such a surface treatment may be a treatment for enhancing the adhesion between the film and the pressure-sensitive adhesive layer (the anchoring property of the pressure-sensitive adhesive layer).

Further, the adhesive sheet of the present invention can have an antistatic layer on the support film, but when it has an antistatic function, a plastic film having an antistatic treatment is used as the support film. It is also possible to do. It is preferable to use the support film because the charge of the pressure-sensitive adhesive sheet itself when peeled off can be suppressed. Further, the support film is a plastic film, and by applying the antistatic treatment to the plastic film, the adhesive sheet itself can be reduced in charge and the adherend has an excellent antistatic ability. The method for imparting the antistatic function is not particularly limited, and a conventionally known method can be used. For example, an antistatic resin, a conductive polymer, or a conductive substance composed of an antistatic agent and a resin component can be used. Examples thereof include a method of applying the contained conductive resin, a method of depositing or plating a conductive substance, and a method of kneading an antistatic agent or the like.

The thickness of the support film is usually about 5 to 200 μm, preferably about 10 to 100 μm. When the thickness of the support film is within the above range, it is preferable because it is excellent in the workability of attaching to the adherend and the workability of peeling from the adherend.

<Adhesive composition>
The pressure-sensitive adhesive sheet (surface protective film) of the present invention has the pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive composition, and the pressure-sensitive adhesive composition has adhesiveness. If so, it can be used without particular limitation, and 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-based pressure-sensitive adhesive, and the like can be used, and more preferably. Is 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, an acrylic-based pressure-sensitive adhesive using a (meth) acrylic-based polymer is used. It is to be.

The pressure-sensitive adhesive composition used in the present invention preferably contains a hydroxyl group and a (meth) acrylic polymer having a carboxyl group. By using the hydroxyl group and the (meth) acrylic polymer having a carboxyl group, the hydroxyl group can easily control the cross-linking, and the carboxyl group improves the shearing force and over time. This is a preferable embodiment because it can prevent an increase in the adhesive strength in The (meth) acrylic polymer in the present invention refers to an acrylic polymer and / or a methacrylic polymer, and the (meth) acrylate refers to an acrylate and / or methacrylate.

Further, the (meth) acrylic polymer can use a hydroxyl group-containing (meth) acrylic monomer as a monomer component. By using the hydroxyl group-containing (meth) acrylic monomer, it becomes easier to control cross-linking of the pressure-sensitive adhesive composition, which in turn improves the wettability due to flow and balances the cohesive force and shear force of the pressure-sensitive adhesive (layer). It becomes easier to control. Furthermore, unlike carboxyl groups and sulfonate groups that can generally act as cross-linking sites, hydroxyl groups have an appropriate interaction with ionic compounds that are antistatic agents, and are therefore suitable in terms of antistatic properties. Can be used.

The pressure-sensitive adhesive sheet of the present invention preferably contains 5.1% by mass or more of the hydroxyl group-containing (meth) acrylic monomer, more preferably 5.1% by mass or more, based on the total amount of the monomer components constituting the (meth) acrylic polymer. 5.3 to 15% by mass, more preferably 7 to 12% by mass. Within the above range, the balance between the wettability of the pressure-sensitive adhesive composition and the cohesive force and shearing force of the pressure-sensitive adhesive (layer) can be easily controlled, which is preferable.

Examples of the hydroxyl group-containing (meth) acrylic monomer 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.

Further, by using the carboxyl group-containing (meth) acrylic monomer as the monomer component of the (meth) acrylic polymer, it is possible to suppress an increase in the adhesive strength of the pressure-sensitive adhesive sheet (adhesive layer) over time. It is preferable because it can be re-peeled, has excellent adhesive strength increase prevention property, and workability, and also has excellent shearing force as well as cohesive force of the adhesive layer.

The pressure-sensitive adhesive sheet of the present invention contains 0.01% by mass or more and less than 0.5% by mass of a carboxyl group-containing (meth) acrylic monomer with respect to the total amount of the monomer components constituting the (meth) acrylic polymer. Is preferable, more preferably 0.01% by mass or more and less than 0.4% by mass, still more preferably 0.01% by mass or more and less than 0.3% by mass, and most preferably 0.01% by mass or more and 0.2% by mass. Less than%. When it is within the above range, it is possible to suppress an increase in the adhesive force with time, and it is excellent in removability, prevention of increase in adhesive force, and workability. Further, it is preferable because it has excellent shearing force as well as cohesive force of the pressure-sensitive adhesive layer. Further, it is preferable because ionic separation can be induced by an appropriate interaction with a solid ionic compound and good antistatic properties can be exhibited. If an acid functional group such as a carboxyl group having a large polar action is present in an excessive amount, the interaction between the acid functional group such as the carboxyl group and the ionic compound occurs when an ionic compound is blended as an antistatic agent. By working strongly, ionic conduction is hindered, conduction efficiency is lowered, and sufficient antistatic property may not be obtained, which is not preferable.

Examples of the carboxyl group-containing (meth) acrylic monomer include (meth) acrylic acid, carboxylethyl (meth) acrylate, carboxylpentyl (meth) acrylate, 2- (meth) acryloyloxyethyl hexahydrophthalic acid, and 2 -(Meta) acryloyloxypropyl hexahydrophthalic acid, 2- (meth) acryloyloxyethyl phthalic acid, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxyethyl maleic acid, carboxy Examples thereof include polycaprolactone mono (meth) acrylate and 2- (meth) acryloyloxyethyl tetrahydrophthalic acid.

The pressure-sensitive adhesive composition used in the present invention is not particularly limited as long as it contains the (meth) acrylic polymer and has adhesiveness, but can be used as a main component of the monomer component. It is preferable to use a (meth) acrylic monomer having an alkyl group having 1 to 14 carbon atoms, and more preferably, a (meth) acrylic monomer having an alkyl group having 4 to 14 carbon atoms. As the (meth) acrylic monomer, one kind or two or more kinds can be used as a main component. The "main component" means that the blending ratio is the highest.

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, t-butyl (meth) acrylate, isobutyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl ( Examples include meta) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-dodecyl (meth) acrylate, n-tridecyl (meth) acrylate, and n-tetradecyl (meth) acrylate. Be done.

Among them, when the pressure-sensitive adhesive sheet of the present invention is used as a surface protective film, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (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. Suitable examples include (meth) acrylates having an alkyl group having 6 to 14 carbon atoms. By using a (meth) acrylate 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 becomes excellent.

The pressure-sensitive adhesive sheet of the present invention contains 50 to 95% by mass of the (meth) acrylic monomer having an alkyl group having 1 to 14 carbon atoms with respect to the total amount of the monomer components constituting the (meth) acrylic polymer. It is preferably 60 to 95% by mass, more preferably 70 to 94.9% by mass, and most preferably 80 to 94.8% by mass. When it is within the above range, the pressure-sensitive adhesive composition has an appropriate wettability and is excellent in the cohesive force of the pressure-sensitive adhesive (layer), which is preferable.

In addition, as other polymerizable monomer components, the Tg is set to 0 ° C. or lower (usually -100 ° C. or higher) so that the adhesive performance can be easily balanced, and the glass transition temperature and peeling of the (meth) acrylic polymer A polymerizable monomer for adjusting the property can be used as long as the effect of the present invention is not impaired.

Other than the hydroxyl group-containing (meth) acrylic monomer used in the (meth) acrylic polymer, the carboxyl group-containing (meth) acrylic monomer, and the (meth) acrylic monomer having an alkyl group having 1 to 14 carbon atoms. The other polymerizable monomer of the above can be used without particular limitation as long as the characteristics of the present invention are not impaired. For example, a cohesiveness / heat resistance improving component such as a cyano group-containing monomer, a vinyl ester monomer, and an aromatic vinyl monomer, an amide group-containing monomer, an imide group-containing monomer, an amino group-containing monomer, an epoxy group-containing monomer, and N-acryloylmorpholin. , A component having a functional group that acts as an adhesive (adhesive) strength improving or cross-linking 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, chloromethylstyrene, α-methylstyrene, and other substituted styrenes.

Examples of the amide group-containing monomer include acrylamide, methacrylamide, diethylacrylamide, N-vinylpyrrolidone, N, N-dimethylacrylamide, N, N-dimethylmethacrylicamide, N, N-diethylacrylamide, N, N-diethyl. Examples thereof include methacrylamide, N, N'-methylenebisacrylamide, N, N-dimethylaminopropylacrylamide, N, N-dimethylaminopropyl methacrylamide, diacetone acrylamide and the like.

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, and N, N-dimethylaminopropyl (meth) acrylate.

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

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

In the present invention, the carboxyl group-containing (meth) acrylic monomer, the hydroxyl group-containing (meth) acrylic monomer, and other polymerizable monomers other than the (meth) acrylic monomer having an alkyl group having 1 to 14 carbon atoms. Is preferably 0 to 40% by mass, more preferably 0 to 30% by mass, based on the total amount of the monomer components (total monomer components) constituting the (meth) acrylic polymer. By using the other polymerizable monomer within the above range, good interaction with an ionic compound that can be used as an antistatic agent and good removability can be appropriately adjusted.

The (meth) acrylic polymer has a weight average molecular weight of 100,000 to 5 million, preferably 200,000 to 4 million, and more preferably 300,000 to 3 million. When the weight average molecular weight is less than 100,000, the cohesive force of the pressure-sensitive adhesive composition tends to be small, resulting in adhesive residue. On the other hand, when the weight average molecular weight exceeds 5 million, the fluidity of the polymer decreases and the wettability to the adherend (for example, a polarizing plate which is an optical member) becomes insufficient, and the adherend and the adhesive sheet adhere to each other. It tends to cause blisters that occur between the agent composition layer. The weight average molecular weight is obtained by measuring by GPC (gel permeation chromatography).

The glass transition temperature (Tg) of the (meth) acrylic polymer is preferably 0 ° C. or lower, more preferably −10 ° C. or lower, still more preferably −20 ° C. or lower (usually −100 ° C. or higher). .. When the glass transition temperature is higher than 0 ° C., the polymer does not easily flow, and for example, the wettability to the adherend (for example, a polarizing plate which is an optical member) becomes insufficient, and the pressure-sensitive adhesive composition of the adherend and the pressure-sensitive adhesive sheet It tends to cause blisters that occur between the material layer. In particular, when the glass transition temperature is set to −61 ° C. or lower, it becomes easy to obtain a pressure-sensitive adhesive composition having excellent wettability to an adherend and light peelability. The glass transition temperature of the (meth) acrylic polymer can be adjusted within the above range by appropriately changing the monomer component and composition ratio used.

The polymerization method of the (meth) acrylic polymer used in the present invention is not particularly limited and can be polymerized by known methods such as solution polymerization, emulsion polymerization, massive polymerization and suspension polymerization, but from the viewpoint of workability in particular. In addition, solution polymerization is a more preferable embodiment from the viewpoint of characteristics such as low contamination to the adherend. Further, the obtained polymer may be any of a random copolymer, a block copolymer, an alternating copolymer, a graft copolymer and the like.

In the pressure-sensitive adhesive sheet of the present invention, the pressure-sensitive adhesive composition can contain an antistatic agent and can contain an ionic compound as the antistatic agent, and is particularly solid at room temperature (25 ° C.). It preferably contains an ionic compound having an organic cation. By containing an ionic compound having an organic cation that is solid at room temperature, the stability of the ionic compound is high when heat above room temperature is applied, and the exfoliation charge stability after storage over time at high temperature is excellent. This is a preferred embodiment.

As the ionic compound solid at room temperature (25 ° C.), a compound composed of an organic cation component represented by the following general formulas (A) to (E) and an anion component is preferably used. An ionic compound having these cations can provide a compound having further excellent antistatic ability.

_Ra in the formula (A) represents a hydrocarbon group having 4 to 20 carbon atoms, and may be a functional group in which a part of the hydrocarbon group is substituted with a hetero atom, and R _b and R _c. Represents hydrogen or a hydrocarbon group having 1 to 16 carbon atoms, which may be the same or different, and may be a functional group in which a part of the hydrocarbon group is substituted with a hetero atom. However, when the nitrogen atom contains a double bond, there is no _{R c.}

R _d in the formula (B) represents a hydrocarbon group having from 2 to 20 carbon atoms, a part of the hydrocarbon group may be substituted by a functional group with a hetero atom, R _e, R _f , And _Rg may be the same or different, representing hydrogen or a hydrocarbon group having 1 to 16 carbon atoms, and may be a functional group in which a part of the hydrocarbon group is substituted with a hetero atom.

_{R h} in the formula (C) represents a hydrocarbon group having 2 to 20 carbon atoms, and may be a functional group in which a part of the hydrocarbon group is substituted with a hetero atom, and R _i , R _j. , And R _k are the same or different and represent hydrogen or a hydrocarbon group having 1 to 16 carbon atoms, and may be a functional group in which a part of the hydrocarbon group is substituted with a hetero atom.

Z in the formula (D) represents a nitrogen, sulfur, or phosphorus atom, and R _l , R _m , R _n , and _Ro represent the same or different hydrocarbon groups having 1 to 20 carbon atoms. , A functional group in which a part of the hydrocarbon group is substituted with a hetero atom may be used. However, when Z is a sulfur atom, there is no _Ro.

R _P in the formula (E) represents a hydrocarbon group having 1 to 18 carbon atoms, a part of the hydrocarbon group may be substituted by a functional group with a heteroatom.

Examples of the cation represented by the formula (A) include a pyridinium cation, a piperidinium cation, a pyrrolidinium cation, a cation having a pyrroline skeleton, a cation having a pyrrole skeleton, a morpholinium cation and the like.

Specific examples include, for example, 1-ethylpyridinium cation, 1-butylpyridinium cation, 1-hexylpyridinium cation, 1-butyl-3-methylpyridinium cation, 1-butyl-4-methylpyridinium cation, 1-hexyl. -3-Methylpyridinium cation, 1-butyl-3,4-dimethylpyridinium cation, 1,1-dimethylpyrrolidinium cation, 1-ethyl-1-methylpyrrolidinium cation, 1-methyl-1-propylpyrrolidi Nium cation, 1-methyl-1-butylpyrrolidinium cation, 1-methyl-1-pentylpyrrolidinium cation, 1-methyl-1-hexylpyrrolidinium cation, 1-methyl-1-heptylpyrrolidinium Cation, 1-ethyl-1-propylpyrrolidinium cation, 1-ethyl-1-butylpyrrolidinium cation, 1-ethyl-1-pentylpyrrolidinium cation, 1-ethyl-1-hexylpyrrolidinium cation , 1-Ethyl-1-heptylpyrrolidinium cation, 1,1-dipropylpyrrolidinium cation, 1-propyl-1-butylpyrrolidinium cation, 1,1-dibutylpyrrolidinium cation, pyrrolidinium-2 -On cation, 1-propylpiperidinium cation, 1-pentylpiperidinium cation, 1,1-dimethylpiperidinium cation, 1-methyl-1-ethylpiperidinium cation, 1-methyl-1-propylpi Peridinium cation, 1-methyl-1-butylpiperidinium cation, 1-methyl-1-pentylpiperidinium cation, 1-methyl-1-hexylpiperidinium cation, 1-methyl-1-heptylpiperidinium Nium cation, 1-ethyl-1-propyl piperidinium cation, 1-ethyl-1-butyl piperidinium cation, 1-ethyl-1-pentyl piperidinium cation, 1-ethyl-1-hexyl piperidinium cation , 1-Ethyl-1-heptyl piperidinium cation, 1,1-dipropyl piperidinium cation, 1-propyl-1-butyl piperidinium cation, 1,1-dibutyl piperidinium cation, 2-methyl -1-Pyroline cation, 1-ethyl-2-phenylindole cation, 1,2-dimethylindole cation, 1-ethylcarbazole cation, N-ethyl-N-methylmorpholinium cation and the like. Be done.

Examples of the cation represented by the formula (B) include an imidazolium cation, a tetrahydropyrimidinium cation, and a dihydropyrimidinium cation.

Specific examples include, for example, 1,3-dimethylimidazolium cation, 1,3-diethyl imidazolium cation, 1-ethyl-3-methyl imidazolium cation, 1-butyl-3-methyl imidazolium cation, 1-. Xyl-3-methylimidazolium cation, 1-octyl-3-methylimidazolium cation, 1-decyl-3-methylimidazolium cation, 1-dodecyl-3-methylimidazolium cation, 1-tetradecyl-3-methylimidazolium cation Lium cation, 1,2-dimethyl-3-propylimidazolium cation, 1-ethyl-2,3-dimethylimidazolium cation, 1-butyl-2,3-dimethylimidazolium cation, 1-hexyl-2,3 -Dimethylimidazolium cation, 1- (2-methoxyethyl) -3-methylimidazolium cation, 1,3-dimethyl-1,4,5,6-tetrahydropyrimidinium cation, 1,2,3-trimethyl- 1,4,5,6-Tetrahydropyrimidinium cation, 1,2,3,4-tetramethyl-1,4,5,6-tetrahydropyrimidinium cation, 1,2,3,5-tetramethyl- 1,4,5,6-Tetrahydropyrimidinium cation, 1,3-dimethyl-1,4-dihydropyrimidinium cation, 1,3-dimethyl-1,6-dihydropyrimidinium cation, 1,2, 3-trimethyl-1,4-dihydropyrimidinium cation, 1,2,3-trimethyl-1,6-dihydropyrimidinium cation, 1,2,3,4-tetramethyl-1,4-dihydropyrimidi Nium cations, 1,2,3,4-tetramethyl-1,6-dihydropyrimidinium cations and the like can be mentioned.

Examples of the cation represented by the formula (C) include a pyrazolium cation and a pyrazolinium cation.

Specific examples include, for example, 1-methylpyrazolium cation, 3-methylpyrazolium cation, 1-ethyl-2-methylpyrazolinium cation, 1-ethyl-2,3,5-trimethylpyrazolium cation. , 1-propyl-2,3,5-trimethylpyrazolium cation, 1-butyl-2,3,5-trimethylpyrazolium cation, 1-ethyl-2,3,5-trimethylpyrazolinium cation, 1 Examples thereof include -propyl-2,3,5-trimethylpyrazolinium cation and 1-butyl-2,3,5-trimethylpyrazolinium cation.

Examples of the cation represented by the formula (D) include a tetraalkylammonium cation, a trialkylsulfonium cation, a tetraalkylphosphonium cation, and a part of the alkyl group is substituted with an alkenyl group, an alkoxyl group, or an epoxy group. There are things like epoxide.

Specific examples include, for example, tetramethylammonium cation, tetraethylammonary cation, tetrabutylammonium cation, tetrapentylammonium cation, tetrahexylammonium cation, tetraheptylammonium cation, triethylmethylammonium cation, tributylethylammonary cation, and trimethyldecylammonium cation. , N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium cation, glycidyl trimethyl ammonium cation, trimethyl sulfonium cation, triethyl sulfonium cation, tributyl sulfonium cation, trihexyl sulfonium cation, diethyl methyl sulfonium cation, dibutyl Ethylsulfonium cation, dimethyldecylsulfonium cation, tetramethylphosphonium cation, tetraethylphosphonium cation, tetrabutylphosphonium cation, tetrahexylphosphonium cation, tetraoctylphosphonium cation, triethylmethylphosphonium cation, tributylethylphosphonium cation, trimethyldecylphosphonium cation, diallyldimethyl Examples thereof include ammonium cations and tributyl- (2-methoxyethyl) phosphonium cations. Among them, asymmetrical ones such as triethylmethylammonium cation, tributylethylammonium cation, trimethyldecylammonium cation, diethylmethylsulfonium cation, dibutylethylsulfonium cation, dimethyldecylsulfonium cation, triethylmethylphosphonium cation, tributylethylphosphonium cation and trimethyldecylphosphonium cation. Tetraalkylammonium cation, trialkylsulfonium cation, tetraalkylphosphonium cation, N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium cation, glycidyltrimethylammonium cation, diallyldimethylammonium cation, N, N -Dimethyl-N-ethyl-N-propylammonary cation, N, N-dimethyl-N-ethyl-N-butylammonary cation, N, N-dimethyl-N-ethyl-N-pentylammonary cation, N, N-dimethyl -N-ethyl-N-hexyl ammonium cation, N, N-dimethyl-N-ethyl-N-heptyl ammonium cation, N, N-dimethyl-N-ethyl-N-nonyl ammonium cation, N, N-dimethyl-N , N-dipropylammonary cation, N, N-diethyl-N-propyl-N-butylammonary cation, N, N-dimethyl-N-propyl-N-pentylammonary cation, N, N-dimethyl-N-propyl- N-hexylammonary cation, N, N-dimethyl-N-propyl-N-heptylammonium cation, N, N-dimethyl-N-butyl-N-hexylammonary cation, N, N-diethyl-N-butyl-N- Heptylammonium cation, N, N-dimethyl-N-pentyl-N-hexylammonium cation, N, N-dimethyl-N, N-dihexylammonium cation, trimethylheptylammonium cation, N, N-diethyl-N-methyl-N -Propylammonary cation, N, N-diethyl-N-methyl-N-pentylammonium cation, N, N-diethyl-N-methyl-N-heptylammonium cation, N, N-diethyl-N-propyl-N-pentyl Ammonium cation, triethylpropylammonary cation, triethylpentylammonium cation, triethylheptylammonium cation, N, N- Dipropyl-N-Methyl-N-Ethylammonium cation, N, N-Dipropyl-N-Methyl-N-Pentylammonary cation, N, N-Dipropyl-N-butyl-N-Hexylammonary cation, N, N-Dipropyl- N, N-dihexyl ammonium cation, N, N-dibutyl-N-methyl-N-pentyl ammonium cation, N, N-dibutyl-N-methyl-N-hexyl ammonium cation, trioctyl methyl ammonium cation, N-methyl- N-ethyl-N-propyl-N-pentylammonium cations are preferably used.

Examples of the cation represented by the formula (E) include a sulfonium cation and the like. Further, the formula Specific examples of R _P in (E) is a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group, nonyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group, Examples thereof include an octadecyl group.

On the other hand, the anion component is not particularly limited as long as it can form a solid ionic compound at room temperature (25 ° C.), and is, 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 CO) N ⁻ , C ₉ H ₁₉ COO ⁻ , (CH ₃ ) ₂ 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 ⁻ , (FSO ₂ ) ₂ N ^{− and the} like are used.

Further, as the anion component, an anion represented by the following formula (F) can also be used.

Specific examples of the ionic compound used in the present invention include appropriately selected from the combination of the cationic component and the anionic component, and are used, for example, 1-butylpyridinium bromide, 1-butylpyridinium chloride, 1-butylpyridinium hexafluoro. Phosphate, 1-butyl-3-methylpyridinium bromide, 1-butyl-3-methylpyridinium chloride, 1-butyl-3-methylpyridinium hexafluorophosphate, 1-butyl-4-methylpyridinium bromide, 1-butyl-4- Methylpyridinium chloride, 1-butyl-4-methylpyridinium hexafluorophosphate, 1-hexylpyridinium bromide, 1-hexylpyridinium chloride, 1-hexylpyridinium hexafluorophosphate, 1-octylpyridinium hexafluorophosphate, 1-nonylpyridinium hexafluoro Phosphate, 2-methyl-1-dodecylpyridinium hexafluorophosphate, 4-methyl-1-octylpyridinium hexafluorophosphate, 1-octylpyridinium dodecylbenzenesulfonate, 1-dodecylpyridinium thiocyanate, 1-dodecylpyridinium dodecylbensen sulfonate, 1- Butyl-1-pyrrolidinium bromide, 1-butyl-1-pyrrolidinium chloride, 1-butyl-1-pyrrolidinium hexafluorophosphate, 1-butyl-1-pyrrolidinium tetrafluoroborate, 1-butyl- 1-Methylpiperidinium bromide, 1-allyl-3-methylimidazolium chloride, 1-benzyl-3-methylimidazolium chloride, 1-benzyl-3-methylimidazolium hexafluorophosphate, 1-benzyl-3-methyl Imidazolium tetrafluoroborate, 1-butyl-2,3-dimethylimidazolium bromide, 1-butyl-2,3-dimethylimidazolium chloride, 1-butyl-2,3-dimethylimidazolium hexafluorophosphate, 1-butyl -2,3-Dimethylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium bromide, 1-butyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium, 1-ethyl-2, 3-Dimethylimidazolim chloride, 1-ethyl-2,3-Dimethylimidazole Rium hexafluorophosphate, 1-ethyl-2,3-dimethylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium bromide, 1-ethyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazole Rium hexafluorophosphate, 1-ethyl-3-methylimidazolium-p-toluene sulfonate, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium benzoate, tetrabutylammonium methanesulfonate, tetrabutylammonium nonafluorobutane sulfonate, tetra Butylammonium hexafluorophosphate, tetrabutialammonium tetrafluoroborate, tetrabutylammonium trifluoromethanesulfonate, tetrabutylammonium bis (trifluoromethanesulfonyl) imide, tetraethylammonium trifluoroacetate, tetraethylammonium perchlorate, tetraethylammonium chloride, tetraethylammonium bromide. , Tetraethylammonium tetrafluoroborate, tetrahexylammonium bromide, tetrahexylammonium chloride, tetrahexylammonium tetrafluoroborate, tetraheptylammonium bromide, tetraheptylammonium chloride, tetraoctylammonium bromide, tetraoctylammonium chloride, tetrapentylammonium thiocyanate, tetra. Pentylammonium bromide, tetrapentylammonium chloride, hexyltrimethylammonium bis (trifluoromethanesulfonyl) imide, hexyltrimethylammonium bromide, hexyltrimethylammonium chloride, tetrabutylphosphonium bromide, tetrabutylphosphonium chloride, tetrabutylphosphonium tetrafluoroborate, theotra Examples thereof include butylphosphonium methanesulfonate and tetrabutylhexadecylphosphonium bromide.

Commercially available ionic compounds may be used as described above, but they can also be synthesized as described below. The method for synthesizing an ionic compound is not particularly limited as long as the desired ionic compound can be obtained, but in general, the document "Ionic Liquid-Forefront and Future of Development-" [published by CMC Publishing Co., Ltd. ], Halide method, hydroxide method, acid ester method, complex formation method, neutralization method and the like are used.

The following shows the synthesis method of the halide method, hydroxide method, acid ester method, complex formation method, and neutralization method using a nitrogen-containing onium salt as an example, but other sulfur-containing onium salts, phosphorus-containing onium salts, etc. The ionic compound of can be obtained by the same method.

The halide method is a method carried out by a reaction as shown in the following formulas (1) to (3). First, a tertiary amine is reacted with an alkyl halide to obtain a halide. (Reaction formula (1), chlorine, bromine, and iodine are used as halogens.) An acid (HA) or salt (MA, M) having ^{an anionic structure (A −) of an ionic compound intended for the obtained halide.} ammonium, lithium, sodium, ionic compound is reacted with a cation) which forms a salt with an objective anion such as potassium and an object (R 4 _NA) is obtained.

The hydroxide method is a method carried out by a reaction as shown in (4) to (8). First halide _(R 4 NX) ion-exchange membrane method electrolysis (reaction equation (4)), OH-type ion exchange resin method (reaction equation (5)) or silver oxide _(Ag 2 O) and of the reaction (reaction formula ( 6)) to obtain a _{hydroxide (R 4 NOH).} (Chlorine, bromine, and iodine are used as halogens.) The obtained hydroxide is subjected to the reaction of the reaction formulas (7) to (8) in the same manner as in the above halogenation method, and the target ionic compound (R _{4) is used.} NA) is obtained.

The acid ester method is a method carried out by a reaction as shown in (9) to (11). First tertiary amine (R 3 _N) is reacted with acid ester to obtain ester product. (In the reaction formula (9), as the acid ester, an ester of an inorganic acid such as sulfuric acid, sulfite, phosphoric acid, arphoic acid or carbonic acid, or an ester of an organic acid such as methanesulfonic acid, methylphosphonic acid or formic acid is used). the resulting ester was the halogenation process as well as the reaction formula (10) to the ionic compound of interest by using the reaction of (11) (R 4 _NA) is obtained. Further, a directly ionic compound can also be obtained by using methyltrifluoromethanesulfonate, methyltrifluoroacetate or the like as the acid ester.

The complex formation method is a method performed by a reaction as shown in (12) to (15). First, quaternary ammonium halide (R ₄ NX), quaternary ammonium hydroxide (R ₄ NOH), quaternary ammonium carbonate esterified product (R ₄ NOCO ₂ CH ₃ ), etc. are added to hydrogen fluoride (HF). React with ammonium fluoride (NH ₄ F) to obtain a quaternary ammonium fluoride salt. (Reaction formulas (12) to (14)) The obtained quaternary ammonium fluoride salt was subjected to a complex formation reaction with fluorides such _{as BF 3} , AlF ₃ , PF ₅ , AsF ₅ , SbF ₅ , NbF ₅ , and TaF _5. , Ionic compounds can be obtained. (Reaction formula (15))

The neutralization method is a method performed by a reaction as shown in (16). Tertiary amines and HBF ₄ , HPF ₆ , CH ₃ COOH, CF ₃ COOH, CF ₃ SO ₃ H, (CF ₃ SO ₂ ) ₂ NH, (CF ₃ SO ₂ ) ₃ CH, (C ₂ F ₅ SO ₂ ) ₂ It can be obtained by reacting with an organic acid such as NH.

R in the above formulas (1) to (16) represents hydrogen or a hydrocarbon group having 1 to 20 carbon atoms, even if a part of the hydrocarbon group is a functional group substituted with a hetero atom. good.

Further, the content of the ionic compound is preferably 2 parts by mass or less, more preferably 0.001 to 1.5 parts by mass, and more preferably 0. It is 005 to 1 part by mass. When it is within the above range, it is easy to achieve both antistatic property and low pollution property, which is preferable.

In the pressure-sensitive adhesive sheet of the present invention, it is preferable that the pressure-sensitive adhesive composition contains a compound having an oxyalkylene chain. The compound having an oxyalkylene chain is preferable because it has an oxyalkylene chain and therefore interacts with the ionic compound to improve conductivity. Further, it is more preferable that the compound having an oxyalkylene chain is an organopolysiloxane having an oxyalkylene chain. It is presumed that by using the organopolysiloxane, the surface free energy of the surface of the pressure-sensitive adhesive is reduced, and light peeling at the time of high-speed peeling is realized.

(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, an organopolysiloxane having a known polyoxyalkylene main chain can be appropriately used, but it is preferably represented by the following formula.

(In the formula, 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 may be branched. The terminal of the above may be an alkoxy group or a hydroxyl group. Further, _{either one of R 1 and} R ₂ may be a hydroxyl group, or an alkyl group or an alkoxy group, and the alkyl group may be used. A group or a part of the alkoxy group may be a functional group substituted with a hetero atom. 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 is used. It is presumed that by using the organosiloxane having the oxyalkylene chain, the compatibility with the (meth) acrylic polymer and the ionic compound is balanced, and light peeling is realized.

Further, as the organopolysiloxane in the present invention, for example, the following constitution 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 the oxyalkylene chain includes an oxymethylene group, an oxyethylene group, and an oxy. Examples thereof include a propylene group and an oxybutylene group, and among them, an oxyethylene group and an oxypropylene group are preferable. When _{both R 1} and R ₂ have an oxyalkylene chain, they may be the same or different.

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

Further, the terminal of the oxyalkylene chain may be an alkoxy group or a hydroxyl group, but more preferably an alkoxy group. When a separator is attached to the surface of the adhesive layer for the purpose of protecting the adhesive surface, an organopolysiloxane having a hydroxyl group at the end causes an interaction with the separator and increases the peeling force when the separator is peeled from the surface of the adhesive layer. May be done.

Further, 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, which is a preferable embodiment. Further, the molecule may have a reactive substituent such as a (meth) acryloyl group, an allyl group, or a hydroxyl group. The organopolysiloxane may be used alone or in combination of two or more.

Specific examples of the organopolysiloxane having the oxyalkylene chain include, for example, commercially available products whose trade names are X-22-4952, X-22-2272, X-22-6266, KF-6004, and KF-889. (The above is manufactured by Shin-Etsu Chemical Co., Ltd.), BY16-201, SF8427 (above, manufactured by Toray Dow Corning Co., Ltd.), IM22 (manufactured by 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。) Further, in addition to the organosiloxane having (bonding) an oxyalkylene chain in the main chain, it is also possible to use an organosiloxane having (binding) an oxyalkylene chain in the side chain, and it is also possible to use oxy in the side chain rather than the main chain. It is a more preferable embodiment to use an organosiloxane having an alkylene chain. As the organopolysiloxane, an organopolysiloxane having a known polyoxyalkylene side chain can be appropriately used, but it is preferably represented by the following formula.

(In the formula, R ₁ is a monovalent organic group, R ₂ , R ₃ and R ₄ are alkylene groups, R ₅ is a hydrogen or organic group, and m and n are integers from 0 to 1000. However, m and n are simultaneous. It cannot be 0. a and b are integers from 0 to 100. However, a and b cannot be 0 at the same time.)

Further, as the organopolysiloxane in the present invention, for example, the following constitution can be used. _{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 alkyl group such as a benzyl group or a phenethyl group. It is an organic group and may have a substituent such as a hydroxyl group. R _{2, R 3} and _{R 4} may be used a methylene group, an ethylene group, an alkylene group having 1 to 8 carbon atoms such as 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. Either one of R ₃ and R ₄ is preferably an ethylene group or a propylene group in order to increase the concentration of an ionic compound that can be dissolved in the polyoxyalkylene side chain. R ₅ may be a monovalent organic group exemplified by an alkyl group such as a methyl group, an ethyl group or a propyl group or an acyl group such as an acetyl group or a propionyl group, and each has a substituent such as a hydroxyl group. You 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 a (meth) acryloyl group, an allyl group, or a hydroxyl group. Among the organosiloxanes having the polyoxyalkylene side chain, the organosiloxane having the polyoxyalkylene side chain having a hydroxyl group terminal is preferable because it is presumed that the compatibility is easily balanced.

Specific examples of the organosiloxane include commercial products with trade names KF-351A, KF-352A, KF-353, KF-354L, KF-355A, KF-615A, KF-945, KF-640, and KF. -642, KF-643, KF-6022, X-22-6191, X-22-4515, KF-6011, KF-6012, KF-6015, KF-6017, X-22-2516 (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 (all manufactured by Toray Dow Corning), 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-UV3500, BYK-UV3570 (manufactured by Big Chemie Japan) and the like. These compounds may be used alone or in combination of two or more.

As the organosiloxane used in the present invention, the HLB (Hydrophile-Lipophilic Balance) value is preferably 1 to 16, and more preferably 3 to 14. If the HLB value is out of the above range, the contamination of the adherend becomes worse, which is not preferable.

The content of the organopolysiloxane is preferably 0.01 to 5 parts by mass, more preferably 0.03 to 3 parts by mass, and further preferably 0.03 to 3 parts by mass with respect to 100 parts by mass of the (meth) acrylic polymer. Is 0.05 to 1 part by mass. Within the above range, the ionic compound having a solid organic cation at room temperature (25 ° C.) and the organopolysiloxane can stably interact with each other even at a high temperature, and the conductivity is improved and the temperature is high. The peeling band voltage after storage over time can be suppressed to a low level, and light peeling property (removability) can be satisfied, which is a preferable embodiment.

In the surface protective film of the present invention, it is preferable that the pressure-sensitive adhesive composition contains a cross-linking agent. Further, in the present invention, the pressure-sensitive adhesive composition is used to form a pressure-sensitive adhesive layer. For example, when the pressure-sensitive adhesive contains the (meth) acrylic polymer, the cross-linking is performed by appropriately adjusting the structural unit, the composition ratio, the selection of the cross-linking agent, the addition ratio, etc. of the (meth) acrylic polymer. , A pressure-sensitive adhesive sheet (adhesive layer) having better heat resistance can be obtained.

As the cross-linking agent used in the present invention, an isocyanate compound, an epoxy compound, a melamine resin, an aziridine derivative, a metal chelate compound and the like may be used, and the use of an isocyanate compound is particularly preferable. Further, these compounds may be used alone or in combination of two or more.

Examples of the isocyanate compound (isocyanate-based cross-linking agent) include aliphatic polyisocyanates such as trimethylene diisocyanate, butylene diisocyanate, hexamethylene diisocyanate (HDI), and dimerate diisocyanate, cyclopentylene diisocyanate, cyclohexylene diisocyanate, and isophorone diisocyanate. Aliphatic isocyanates such as (IPDI), aromatic isocyanates such as 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate (XDI), allophanate bond, biuret bond, isocyanate of the isocyanate compound. Examples thereof include polyisocyanate modified products modified by nulate bond, uretdione bond, urea bond, carbodiimide bond, uretonimine bond, oxadiazine trione bond and the like. For example, as commercial products, trade names Takenate 300S, Takenate 500, Takenate D165N, Takeda D178N (above, manufactured by Takeda Pharmaceutical Company Limited), Sumijuru T80, Sumijuru L, Death Module N3400 (above, manufactured by Sumika Bayer Urethane) , Millionate MR, Millionate MT, Coronate L, Coronate HL, Coronate HX (all manufactured by Nippon Polyurethane Industry Co., Ltd.) and the like. These isocyanate compounds may be used alone or in combination of two or more, or 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 adhesiveness and resilience (adhesiveness to a curved surface), and a surface protective film having more excellent adhesive reliability can be obtained.

Examples of the epoxy compound include N, N, N', N'-tetraglycidyl-m-xylene diamine (trade name: TETRAD-X, manufactured by Mitsubishi Gas Chemical Company, Inc.) and 1,3-bis (N, N-diamine). Glycidylaminomethyl) cyclohexane (trade name: TETRAD-C, manufactured by Mitsubishi Gas Chemical Company, Inc.) and the like can be mentioned.

Examples of the melamine-based resin include hexamethylol melamine. Examples of the aziridine derivative include commercially available trade names HDU, TAZM, and TAZO (all manufactured by Mutual Pharmaceutical Co., Ltd.).

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

The content of the cross-linking agent used in the present invention is preferably 0.01 to 10 parts by mass, preferably 0.1 to 8 parts by mass, based on 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 1.0 to 2.5 parts by mass. If the content is less than 0.01 parts by mass, the cross-linking by the cross-linking agent is insufficient, the cohesive force of the obtained pressure-sensitive adhesive layer is reduced, and sufficient heat resistance may not be obtained. It tends to cause adhesive 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, the polarizing plate) is insufficient, and the adherend and the pressure-sensitive adhesive are used. It tends to cause blisters that occur between the layer (adhesive composition layer). Further, if the amount of the cross-linking agent is large, the peeling charging property tends to decrease. Further, these cross-linking agents may be used alone or in combination of two or more.

The pressure-sensitive adhesive composition may further contain a cross-linking catalyst in order to more effectively proceed with any of the above-mentioned cross-linking reactions. Examples of such cross-linking catalysts include tin-based catalysts such as dibutyltin dilaurate and dioctyltin dilaurate, tris (acetylacetonato) iron, tris (hexane-2,4-dionat) iron, and tris (heptane-2,4-dionat). ) Iron, Tris (Heptane-3,5-Zionato) Iron, Tris (5-Methylhexane-2,4-Zionato) Iron, Tris (Octane-2,4-Zionato) Iron, Tris (6-Methylheptane-2) , 4-Zionato) Iron, Tris (2,6-dimethylheptane-3,5-Zionato) Iron, Tris (Nonan-2,4-Zionato) Iron, Tris (Nonan-4,6-Zionato) Iron, Tris ( 2,2,6,6-tetramethylheptane-3,5-dionat) iron, tris (tridecane-6,8-dionat) iron, tris (1-phenylbutane-1,3-dionat), tris (hexafluoro) Acetylacetonato iron, tris (ethylacetate acetate) iron, tris (acetoacetate-n-propyl) iron, tris (isopropylacetate isopropyl) iron, tris (acetoacetate-n-butyl) iron, tris (acetoacetate-sec) -Butyl) iron, tris (acetoacetate-tert-butyl) iron, tris (propionylmethylacetate) iron, tris (propionylacetate ethyl) iron, tris (propionylacetate-n-propyl) iron, tris (propionylacetate 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, Iron-based catalysts such as tris (diethyl malonate) iron, trimethoxy iron, triethoxy iron, triisopropoxy iron, and ferric chloride can be used. These cross-linking catalysts may be used alone or in combination of two or more.

The content (usage amount) of the cross-linking catalyst is not particularly limited, but is preferably about 0.0001 to 1 part by mass, and 0.001 to 0.5 parts by mass, for example, with respect to 100 parts by mass of the (meth) acrylic polymer. Parts by mass are more preferred. When it is within the above range, the rate of the cross-linking reaction is high when the pressure-sensitive adhesive layer is formed, and the pot life of the pressure-sensitive adhesive composition is also long, which is a preferable embodiment.

The pressure-sensitive adhesive composition of the present invention can contain a polyoxyalkylene chain-containing compound (including a compound having an oxyalkylene chain) that does not contain organopolysiloxane. By containing the above compound in the pressure-sensitive adhesive composition, a pressure-sensitive adhesive composition having further excellent wettability to an adherend can be obtained.

Specific examples of the polyoxyalkylene chain-containing compound containing no organopolysiloxane include polyoxyalkylene alkylamine, polyoxyalkylenediamine, polyoxyalkylene fatty acid ester, polyoxyalkylene sorbitan fatty acid ester, and polyoxyalkylene alkylphenyl. Nonionic surfactants such as ethers, polyoxyalkylene alkyl ethers, polyoxyalkylene alkyl allyl ethers, polyoxyalkylene alkyl phenyl allyl ethers; polyoxyalkylene alkyl ether sulfate ester salts, polyoxyalkylene alkyl ether phosphate ester salts, Anionic surfactants such as polyoxyalkylene alkyl phenyl ether sulfate ester salts and polyoxyalkylene alkyl phenyl ether phosphoric acid ester salts; in addition, cationic surfactants having a polyoxyalkylene chain (polyalkylene oxide chain) and both ions. Sexual surfactants, polyether compounds with polyoxyalkylene chains (including derivatives thereof), polyester compounds with polyoxyalkylene chains (including derivatives thereof), acrylic compounds with polyoxyalkylene chains (and derivatives thereof) Including) and the like. Further, the polyoxyalkylene chain-containing monomer may be blended with the acrylic polymer as the polyoxyalkylene chain-containing compound. Such a polyoxyalkylene chain-containing compound may be used alone or in combination of two or more.

Specific examples of the polyether compound having a polyoxyalkylene chain include a block copolymer of polypropylene glycol (PPG) -polyethylene glycol (PEG), a block copolymer of PPG-PEG-PPG, and PEG-PPG-PEG. Examples include block copolymers. Examples of the derivative of the polyether compound having a polyoxyalkylene chain include an oxypropylene group-containing compound having an etherified terminal (PPG monoalkyl ether, PEG-PPG monoalkyl ether, etc.) and an oxypropylene group having an acetylated terminal. Examples include contained compounds (terminal acetylated PPG, etc.).

Further, specific examples of the acrylic compound having a polyoxyalkylene chain include a (meth) acrylate polymer having an oxyalkylene group. As the oxyalkylene group, the number of moles of the oxyalkylene unit added is preferably 1 to 50, more preferably 2 to 30, and even more preferably 2 to 20 from the viewpoint of coordinating the ionic compound. Further, the terminal of the oxyalkylene group may remain as a hydroxyl group or may be substituted with an alkyl group, a phenyl group or the like.

The (meth) acrylate polymer having an oxyalkylene group is preferably a polymer containing (meth) acrylate alkylene oxide as a monomer unit (component), and the specific embodiment of the (meth) acrylate alkylene oxide. Examples include ethylene glycol group-containing (meth) acrylates, such as methoxy-polyethylene glycol (meth) acrylate types such as methoxy-diethylene glycol (meth) acrylate and methoxy-triethylene glycol (meth) acrylate, and ethoxy-diethylene glycol. (Meta) acrylate, ethoxy-polyethylene glycol (meth) acrylate type such as ethoxy-triethylene glycol (meth) acrylate, butoxy-polyethylene glycol such as butoxy-diethylene glycol (meth) acrylate, butoxy-triethylene glycol (meth) acrylate ( Phenoxy-polyethylene glycol (meth) acrylate type such as meta) acrylate type, phenoxy-diethylene glycol (meth) acrylate, phenoxy-triethylene glycol (meth) acrylate, 2-ethylhexyl-polyethylene glycol (meth) acrylate, nonylphenol-polyethylene glycol ( Examples thereof include a meth) acrylate type and a methoxy-polypropylene glycol (meth) acrylate type such as methoxy-dipropylene glycol (meth) acrylate.

Further, as the monomer unit (component), other monomer units (components) other than the (meth) acrylic acid alkylene oxide can be used. Specific examples of other monomer units include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, and 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 and / or methacrylate having an alkyl group having 1 to 14 carbon atoms such as acrylate, isodecyl (meth) acrylate, n-dodecyl (meth) acrylate, n-tridecyl (meth) acrylate, and n-tetradecyl (meth) acrylate. Can be mentioned.

Further, as other monomer units (components) other than the (meth) acrylic acid alkylene oxide, a carboxyl group-containing (meth) acrylate, a phosphoric acid group-containing (meth) acrylate, a cyano group-containing (meth) acrylate, and a vinyl ester Kind, 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 -Acryloylmorpholine, vinyl ethers and the like can be used as appropriate.

In a preferred embodiment, the polyoxyalkylene chain-containing compound containing no organopolysiloxane is a compound having at least a part (poly) ethylene oxide chain. By blending the compound having the (poly) ethylene oxide chain, the compatibility between the base polymer and the antistatic component is improved, bleeding to the adherend is suitably suppressed, and a low-contamination pressure-sensitive adhesive composition is obtained. can get. Above all, when a block copolymer of PPG-PEG-PPG is used, a pressure-sensitive adhesive composition having excellent low contamination property can be obtained. As the polyethylene oxide chain-containing compound, the mass of the (poly) ethylene oxide chain in the entire compound is preferably 5 to 90% by mass, more preferably 5 to 85% by mass, and further preferably 5 to 80% by mass. Most preferably, it is 5 to 75% by mass.

The molecular weight of the polyoxyalkylene chain-containing compound containing no organopolysiloxane is preferably one having a number average molecular weight (Mn) of 50,000 or less, more preferably 200 to 30,000, still more preferably 200 to 10,000, and 200 to 5,000. Those are particularly preferably used. If Mn is more than 50,000, the compatibility with the acrylic polymer is lowered and the pressure-sensitive adhesive layer tends to be whitened. If Mn is less than 200, contamination by the polyoxyalkylene compound may easily occur. Here, Mn means a polystyrene-equivalent value obtained by GPC (gel permeation chromatography).

Specific examples of the above-mentioned polyoxyalkylene chain-containing compound containing no organopolysiloxane as commercial products include, for example, ADEKA PLRONIC 17R-4, ADEKA PLRONIC 25R-2 (all manufactured by ADEKA), and Emulgen 120 (all manufactured by ADEKA). Kao Corporation) and so on.

The blending amount of the polyoxyalkylene chain-containing compound containing no organopolysiloxane can be, for example, 0.005 to 20 parts by mass with respect to 100 parts by mass of the (meth) acrylic polymer, and is preferably 0. It is 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, and most preferably 0.1 to 1 part by mass. If the blending amount is too small, the effect of preventing the bleeding of the antistatic component is reduced, and if the blending amount is too large, contamination by the polyoxyalkylene compound may easily occur.

Further, the pressure-sensitive adhesive composition may contain an acrylic oligomer. The weight average molecular weight of the acrylic oligomer is preferably 1000 or more and less than 30,000, more preferably 1500 or more and less than 20,000, and even more preferably 2,000 or more and less than 10,000. The acrylic oligomer is a (meth) acrylic polymer containing a (meth) acrylic monomer having an alicyclic structure represented by the following general formula (1) as a monomer unit, and is used for re-peeling of the present embodiment. When used in the acrylic pressure-sensitive adhesive composition of the above, it functions as a pressure-imparting resin, improves adhesiveness (adhesiveness), and is effective in suppressing floating of the pressure-sensitive adhesive sheet.
CH ₂ = C (R ¹ ) COOR ² (1)
[In formula (1), R ¹ is a hydrogen atom or a methyl group, and R ² is an alicyclic hydrocarbon group having an alicyclic structure].

The alicyclic hydrocarbon group R ² in the general formula (1), a cyclohexyl group, an isobornyl group, an alicyclic hydrocarbon group such as a dicyclopentanyl group. Examples of the (meth) acrylic acid ester having such an alicyclic hydrocarbon group include cyclohexyl (meth) acrylate having a cyclohexyl group, isobornyl (meth) acrylate having an isobornyl group, and dicyclopentanyl group. Examples thereof include esters of (meth) acrylic acid with an alicyclic alcohol such as dicyclopentanyl (meth) acrylic acid. By having the acrylic oligomer having such a relatively bulky structure as a monomer unit in the acrylic oligomer, the adhesiveness (adhesiveness) can be improved.

Further, in the present embodiment, the alicyclic hydrocarbon group constituting the acrylic oligomer preferably has a crosslinked ring structure. The bridging ring structure refers to an alicyclic structure having three or more rings. By giving the acrylic oligomer a bulkier structure such as a bridging ring structure, the adhesive (adhesive) property can be further improved as a pressure-sensitive adhesive composition for re-peeling (adhesive sheet for re-peeling).

^{Examples of R 2} which is an alicyclic hydrocarbon group having a crosslinked ring structure include a dicyclopentanyl group represented by the following formula (3a) and a dicyclopentenyl group represented by the following formula (3b). , Adamantyl group represented by the following formula (3c), tricyclopentanyl group represented by the following formula (3d), tricyclopentenyl group represented by the following formula (3e) and the like. When UV polymerization is used when synthesizing an acrylic oligomer or when producing a pressure-sensitive adhesive composition, an alicyclic structure having three or more rings having a bridging ring structure is used in that polymerization inhibition is unlikely to occur. Among the (meth) acrylic monomers having, the dicyclopentanyl group represented by the following formula (3a), the adamantyl group represented by the following formula (3c), and the tri represented by the following formula (3d). A (meth) acrylic monomer having a saturated structure such as a cyclopentanyl group can be preferably used as a monomer constituting an acrylic oligomer.

Examples of the (meth) acrylic monomer having three or more alicyclic structures having the crosslinked ring structure include dicyclopentanyl methacrylate, dicyclopentanyl acrylate, and dicyclopentanyloxyethyl methacrylate. Dicyclopentanyloxyethyl acrylate, tricyclopentanyl methacrylate, tricyclopentanyl acrylate, 1-adamantyl methacrylate, 1-adamantyl acrylate, 2-methyl-2-adamantyl methacrylate, 2-methyl-2-adamantyl acrylate, 2- Examples thereof include (meth) acrylic acid esters such as ethyl-2-adamantyl methacrylate and 2-ethyl-2-adamantyl acrylate. This (meth) acrylic monomer can be used alone or in combination of two or more.

The acrylic oligomer of the present embodiment may be a copolymer of a (meth) acrylic monomer having an alicyclic structure, or a (meth) acrylic monomer having an alicyclic structure and another (meth) acrylic. It may be an acid ester monomer or a copolymer with a copolymerizable monomer.

Examples of the (meth) acrylic acid ester monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, and (meth). ) Isobutyl acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, hexyl (meth) acrylate, (meth) acrylate- 2-Ethylhexyl, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, (meth) acrylic (Meta) acrylic acid alkyl esters such as isodecyl acid, undecyl (meth) acrylate, and dodecyl (meth) acrylate;
(Meta) acrylic acid aryl esters such as (meth) phenyl acrylate, (meth) benzyl acrylate;
(Meta) acrylic acid ester obtained from a terpene compound derivative alcohol; and the like. Such (meth) acrylic acid esters can be used alone or in combination of two or more.

Further, the acrylic oligomer can be obtained by copolymerizing, in addition to the (meth) acrylic acid ester component unit, another monomer component (copolymerizable monomer) copolymerizable with the (meth) acrylic acid ester. Is.

Other monomers copolymerizable with the (meth) acrylic acid ester include carboxyl groups such as acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid. Containing monomer;
Alkoxyalkyl-based (meth) acrylates such as methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, propoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, ethoxypropyl (meth) acrylate. monomer;
Salts such as (meth) acrylic acid alkali metal salts;
Di (meth) acrylic acid ester of ethylene glycol, di (meth) acrylic acid ester of diethylene glycol, di (meth) acrylic acid ester of triethylene glycol, di (meth) acrylic acid ester of polyethylene glycol, di (meth) of propylene glycol ) Di (meth) acrylic acid ester monomer of (poly) alkylene glycol such as acrylic acid ester, di (meth) acrylic acid ester of dipropylene glycol, di (meth) acrylic acid ester of tripropylene glycol;
Multivalent (meth) acrylic acid ester monomers such as trimethylolpropane tri (meth) acrylic acid ester;
Vinyl esters such as vinyl acetate and vinyl propionate;
Vinyl halide compounds such as vinylidene chloride, -2-chloroethyl (meth) acrylate;
Oxazoline group-containing polymerizable compounds such as 2-vinyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline;
Aziridine group-containing polymerizable compounds such as (meth) acryloyl aziridine and (meth) -2-aziridinyl ethyl acrylate;
Epoxide group-containing vinyl monomers such as allyl glycidyl ether, glycidyl ether (meth) acrylate, -2-ethyl glycidyl ether (meth) acrylate;
Hydroxy group-containing vinyl monomers such as -2-hydroxyethyl (meth) acrylate, -2-hydroxypropyl (meth) acrylate, adducts of lactones and -2-hydroxyethyl (meth) acrylate;
(Meta) acryloyl groups at the ends of polyalkylene glycols such as polypropylene glycol, polyethylene glycol, polytetramethylene glycol, polybutylene glycol, copolymers of polyethylene glycol and polypropylene glycol, copolymers of polybutylene glycol and polyethylene glycol, Macromonomer to which unsaturated groups such as styryl group and vinyl group are bonded;
Fluorine-containing vinyl monomers such as fluorine-substituted (meth) acrylic acid alkyl esters;
Acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride;
Aromatic vinyl compound-based monomers such as styrene, α-methylstyrene, and vinyltoluene;
Reactive halogen-containing vinyl monomers such as 2-chloroethyl vinyl ether, monochloroacetic acid vinyl;
(Meta) acrylamide, N-isopropyl (meth) acrylamide, N-butyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-methylol (meth) acrylamide, N -Amid group-containing vinyl monomers such as ethylol (meth) acrylamide, N-methylolpropane (meth) acrylamide, N-methoxyethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, and N-acrylloylmorpholine;
Succinimide-based monomers such as N- (meth) acryloyloxymethylene succinimide, N- (meth) acryloyl-6-oxyhexamethylene succinimide, and N- (meth) acryloyl-8-oxyhexamethylene succinimide;
Maleimide-based monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, and N-phenylmaleimide;
Itaconimides such as N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-cyclohexylitaconimide, N-laurylitaconimide, etc. System monomer;
N-Vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazin, N-vinylpyrazine, N-vinylpyrrole, N-vinylimidazole, N- Vinyloxazole, N- (meth) acryloyl-2-pyrrolidone, N- (meth) acryloyl piperidine, N- (meth) acryloylpyrrolidin, N-vinylmorpholin, N-vinylpyrazole, N-vinylisoxazole, N-vinylthiazole. , N-Vinyl isothiazole, N-vinylpyridazine and other nitrogen-containing heterocyclic monomers;
N-Vinyl Carboxylic Acid Amides;
Lactam-based monomers such as N-vinylcaprolactam;
(Meta) Cyanoacrylate monomers such as acrylonitrile;
(Meta) acrylics such as aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, t-butylaminoethyl (meth) acrylate, etc. Aminoalkyl acid-based monomer;
Imide group-containing monomers such as cyclohexylmaleimide and isopropylmaleimide;
2-Isocyanate ethyl (meth) acrylate and other isocyanate group-containing monomers;
Organic silicon-containing vinyl monomers such as vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, allyltrimethoxysilane, trimethoxysilylpropylallylamine, 2-methoxyethoxytrimethoxysilane;
(Meta) hydroxyethyl acrylate, (meth) hydroxypropyl acrylate, (meth) hydroxybutyl acrylate, (meth) hydroxyhexyl acrylate, (meth) hydroxyoctyl acrylate, (meth) hydroxydecyl acrylate, (meth) ) Hydroxy lauryl acrylate, hydroxyl group-containing monomers such as (meth) hydroxyalkyl acrylate such as (4-hydroxymethylcyclohexyl) methyl methacrylate;
Acrylic acid ester-based monomers having heterocycles such as tetrahydrofurfuryl (meth) acrylate, fluorine atom-containing (meth) acrylate, and silicone (meth) acrylate, halogen atoms, and silicon atoms;
Olefin monomers such as isoprene, butadiene, and isobutylene;
Vinyl ether-based monomers such as methyl vinyl ether and ethyl vinyl ether;
Olefins or diene such as ethylene, butadiene, isoprene, isobutylene;
Vinyl ethers such as vinyl alkyl ethers;
Vinyl chloride;
In addition, macromonomers having a radically polymerizable vinyl group at the terminal of a monomer obtained by polymerizing a vinyl group can be mentioned. These monomers can be copolymerized with the (meth) acrylic acid ester alone or in combination.

Examples of the acrylic oligomer include a copolymer of cyclohexyl methacrylate (CHMA) and isobutyl methacrylate (IBMA), a copolymer of cyclohexyl methacrylate (CHMA) and isobornyl methacrylate (IBXMA), and methyl methacrylate (MMA) and isobol. Nyl methacrylate (IBXMA) copolymer, cyclohexyl methacrylate (CHMA) and acryloylmorpholin (ACMO) copolymer, cyclohexyl methacrylate (CHMA) and diethyl acrylamide (DEAA) copolymer, 1-adamantyl acrylate (ADA) A copolymer of methyl methacrylate (MMA), a copolymer of dicyclopentanyl methacrylate (DCPMA) and isobornyl methacrylate (IBXMA), a copolymer of dicyclopentanyl methacrylate (DCPMA) and methyl methacrylate (MMA), Dicyclopentanyl methacrylate (DCPMA) and N-vinyl-2-pyrrolidone (NVP) copolymer, dicyclopentanyl methacrylate (DCPMA) and hydroxyethyl methacrylate (HEMA) copolymer, dicyclopentanyl methacrylate (NVP) Copolymer of DCPMA) and acrylic acid (AA), dicyclopentanyl methacrylate (DCPMA), cyclohexyl methacrylate (CHMA), isobornyl methacrylate (IBXMA), isobornyl acrylate (IBXA), dicyclopentanyl acrylate (DCPMA) DCPA), 1-adamantyl methacrylate (ADAM), 1-adamantyl acrylate (ADA), methyl methacrylate (MMA) homopolymers and the like can be mentioned.

Further, the acrylic oligomer may have a functional group that is reactive with an epoxy group or an isocyanate group. Examples of such a functional group include a hydroxyl group, a carboxyl group, an amino group, an amide group, and a mercapto group, and a monomer having such a functional group is used (copolymerized) when producing an acrylic oligomer. You may.

When the acrylic oligomer is a copolymer of a (meth) acrylic monomer having an alicyclic structure and another (meth) acrylic acid ester monomer or a copolymerizable monomer, it has an alicyclic structure (meth). The content ratio of the acrylic monomer is preferably 5% by mass or more, preferably 10% by mass or more, more preferably 20% by mass or more, still more preferably 30% by mass or more, based on all the monomers constituting the acrylic oligomer (). Usually less than 100% by mass, preferably 90% by mass or less). When the (meth) acrylic monomer having an alicyclic structure is contained in an amount of 5% by mass or more, the adhesiveness (adhesiveness) can be improved without lowering the transparency.

The weight average molecular weight of the acrylic oligomer is 1000 or more and less than 30,000, preferably 1500 or more and less than 20000, and more preferably 2000 or more and less than 10000. When the weight average molecular weight is 30,000 or more, the adhesiveness (adhesiveness) is lowered. Further, if the weight average molecular weight is less than 1000, the molecular weight becomes low, which causes a decrease in the adhesive strength of the pressure-sensitive adhesive sheet.

Further, the pressure-sensitive adhesive composition may contain a compound that causes keto-enol tautomerism as a cross-linking retarder. For example, in a pressure-sensitive adhesive composition containing a cross-linking agent or a pressure-sensitive adhesive composition that can be used by blending a cross-linking agent, an embodiment containing the compound that causes keto-enol tautomerization can be preferably adopted. As a result, the effect of suppressing an excessive increase in viscosity and gelation of the pressure-sensitive adhesive composition after blending the cross-linking agent and extending the pot life of the pressure-sensitive adhesive composition can be realized. When at least an isocyanate compound is used as the cross-linking agent, it is particularly meaningful to contain a compound that causes 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 a solvent-free form.

Various β-dicarbonyl compounds can be used as the compound that causes the keto-enol telecommunication. Specific examples include acetylacetone, 2,4-hexanedione, 3,5-heptandione, 2-methylhexane-3,5-dione, 6-methylheptane-2,4-dione, 2,6-dimethylheptane-. Β-Diketones such as 3,5-dione; acetoacetate 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 acid esters such as methyl malate and ethyl malonate; etc. Can be mentioned. Among them, acetylacetone and acetoacetic ester are examples of suitable compounds. The compound that causes such keto-enol tautomerism may be used alone or in combination of two or more.

The content of the compound that causes keto-enol tvariability 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 parts by mass. It is appropriate to use parts by mass (for example, 1 to 10 parts by mass). If the amount of the compound is too small, it may be difficult to exert a sufficient effect of use. On the other hand, if the compound is used in an unnecessarily large amount, it may remain in the pressure-sensitive adhesive layer and reduce the cohesive force.

Further, the pressure-sensitive adhesive composition used for the pressure-sensitive adhesive sheet of the present invention may contain other known additives, for example, powders such as colorants and pigments, surfactants, plasticizers, and pressure-sensitive adhesives. Excipients, 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, It can be appropriately added depending on the intended use of particles, foils and the like.

The pressure-sensitive adhesive sheet of the present invention is characterized by having a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition (formed by cross-linking the pressure-sensitive adhesive composition) on one side or both sides of the support film. The cross-linking of the coating composition is generally performed after the coating of the pressure-sensitive adhesive composition, but it is also possible to transfer the pressure-sensitive adhesive layer made of the pressure-sensitive adhesive composition after the cross-linking to a support film or the like. The method of forming the pressure-sensitive adhesive layer on the support film is not particularly limited. For example, the pressure-sensitive adhesive composition is applied to the support film, a polymerization solvent or the like is dried and removed, and the pressure-sensitive adhesive layer is placed on the support film. It is made by forming. After that, curing may be performed for the purpose of adjusting the component transfer of the pressure-sensitive adhesive layer, adjusting the cross-linking reaction, and the like. Further, when the pressure-sensitive adhesive composition is applied onto the support film to prepare 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 support film. May be added to.

Further, as a method for forming the pressure-sensitive adhesive layer when manufacturing the pressure-sensitive adhesive sheet of the present invention, a known method used for manufacturing pressure-sensitive adhesive sheets is used. Specific examples thereof include a roll coat, a gravure coat, a reverse coat, a roll brush, a spray coat, an air knife coat method, and an extrusion coat method using a die coater or the like.

The pressure-sensitive adhesive sheet of the present invention is usually prepared so that the thickness of the pressure-sensitive adhesive layer is preferably 3 to 100 μm, more preferably about 5 to 50 μm. When the thickness of the pressure-sensitive adhesive layer is within the above range, it is easy to obtain an appropriate balance between removability and adhesiveness (adhesiveness), which is preferable.

<Separator>
In the pressure-sensitive adhesive sheet (surface protection film) of the present invention, a separator can be attached to the surface of the pressure-sensitive adhesive layer for the purpose of protecting the pressure-sensitive adhesive surface, if necessary.

Paper and a plastic film are examples of the material constituting the separator, and the plastic film is preferably used because of its excellent surface smoothness. The film is not particularly limited as long as it can protect the pressure-sensitive adhesive layer, and is, for example, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, and a vinyl chloride co-weight. 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. When it is within the above range, it is preferable because it is excellent in sticking workability to the pressure-sensitive adhesive layer and peeling workability from the pressure-sensitive adhesive layer. If necessary, the separator may be used for mold release and antifouling treatment with a silicone-based, fluorine-based, long-chain alkyl-based or fatty acid amide-based mold release agent, silica powder, etc. It is also possible to carry out antistatic treatment such as.

In the pressure-sensitive adhesive sheet of the present invention (including the case of using it as a surface protective film), the pressure-sensitive adhesive surface of the pressure-sensitive adhesive layer used for the pressure-sensitive adhesive sheet is attached to the TAC surface (polarizing plate surface) at 70 ° C. for 1 week (preservation over time at high temperature). The peeling band voltage at a peeling speed of 30 m / min (later) is less than 0.5 kV (absolute value), more preferably 0.4 kV or less, still more preferably 0.3 kV or less. If the peeling band voltage is 0.5 kV or more, for example, the liquid crystal driver or the like may be damaged, which is not preferable.

<Antistatic layer (top coat layer)>
The pressure-sensitive adhesive sheet of the present invention has an antistatic layer on one side of the support film opposite to the pressure-sensitive adhesive layer, and the antistatic layer contains polyaniline sulfonic acid as a conductive polymer component, polyester resin as a binder, and , It is preferable that it is formed from an antistatic agent composition containing an isocyanate-based cross-linking agent as a cross-linking agent. When the pressure-sensitive adhesive sheet has an antistatic layer (top coat layer), the antistatic property of the pressure-sensitive adhesive sheet is improved, which is a preferable embodiment. In particular, the ionic compound having a solid organic cation at room temperature (25 ° C.) and the organopolysiloxane are stable and interact with each other even at a high temperature, thereby suppressing the peeling zone voltage after storage over time at a high temperature. Can be done. Furthermore, by having the antistatic layer, the surface resistance value of the antistatic layer can be stabilized with time, and the adhesive sheet can be attached to the adherend as a whole and stored at a high temperature for a long time. Even when peeled off, the peeling charge stability can be improved, which is useful.

<Conductive polymer>
The antistatic layer preferably contains polyaniline sulfonic acid as a conductive polymer component. By using the conductive polymer, the antistatic property based on the antistatic layer can be satisfied. Further, although the polyaniline sulfonic acid is "water-soluble", it can be immobilized in the antistatic layer and the water resistance can be improved by using an isocyanate-based cross-linking agent described later. By using the water-soluble conductive polymer-containing aqueous solution, an antistatic layer having an excellent surface resistance value over time can be obtained, which is a preferable embodiment. On the other hand, when the conductive polymer used when forming the antistatic layer is "water-dispersible", when the antistatic layer is formed by using the water-dispersible conductive polymer-containing solution, agglomerates are generated. It is not preferable because it becomes easy to apply, it cannot be applied uniformly, and the surface resistance value with time tends to be significantly 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 further preferably 25 to 150 parts by mass with respect to 100 parts by mass of the binder contained in the antistatic layer (top coat layer). Is 40 to 120 parts by mass. If the amount of the conductive polymer used is too small, the antistatic effect may be small, and if the amount of the conductive polymer used is too large, the adhesion of the antistatic layer to the support film may be reduced or the transparency may be reduced. It is not preferable because it may decrease.

Polyaniline sulfonic acid used as the conductive polymer component has a weight average molecular weight (Mw) in terms of polystyrene is preferably not more 5 × 10 ⁵ or less, more preferably 3 × 10 ⁵ or less. 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 for forming the antistatic layer, a method of applying and drying (or curing) a coating material (antistatic agent composition) for forming the antistatic layer on the first surface of the support film can be adopted, and preparation of the coating material can be adopted. The conductive polymer component used in the above is preferably polyaniline sulfonic acid, a polyester resin as a binder, and an isocyanate-based cross-linking agent as a cross-linking agent, and the essential component is dissolved in water (conductive polymer aqueous solution). , Or simply referred to as an aqueous solution) can be preferably used. Such an aqueous solution of a conductive polymer 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. The hydrophilic functional group, a sulfo group, an amino group, an amide group, an imino group, a hydroxyl group, a mercapto group, a hydrazino group, a carboxyl group, quaternary ammonium groups, sulfate ester 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 salts.

Further, as a commercially available product of the polyaniline sulfonic acid aqueous solution, a trade name "aquaPASS" manufactured by Mitsubishi Rayon Co., Ltd. is exemplified.

The antistatic layer disclosed herein contains polyaniline sulfonic acid (polyaniline type) as an essential component as the conductive polymer component, and for example, one or more other antistatic components (conductive polymer). Other organic conductive substances, inorganic conductive substances, antistatic agents, etc.) may be contained together. In a preferred embodiment, the antistatic layer does not substantially contain an antistatic component other than the conductive polymer, that is, the antistatic component contained in the antistatic layer is substantially only a conductive polymer. The embodiment consisting of may be more preferably carried out.

Examples of the organic conductive substance include cationic antistatic agents having cationic functional groups such as quaternary ammonium salts, pyridinium salts, primary amino groups, secondary amino groups, and tertiary amino groups; sulfonates and sulfate esters. Anionic antistatic agents having anionic functional groups such as salts, phosphonates and phosphate ester salts; amphoteric ionic antistatic agents such as alkylbetaine and its derivatives, imidazoline and its derivatives, alanine and its derivatives; aminoalcohol And nonionic antistatic agents such as glycerin and its derivatives, polyethylene glycol and its derivatives; polymerize monomers having the cationic, anionic and amphoteric ionic conductive groups (eg, quaternary ammonium bases). Alternatively, an ionic conductive polymer obtained by copolymerization; a conductive polymer such as polythiophene, polyaniline, polypyrrole, polyethyleneimine, an allylamine-based polymer; can be mentioned. Such an antistatic agent may be used alone or in combination of two or more.

Examples of the inorganic conductive substance include tin oxide, antimony oxide, indium oxide, cadmium oxide, titanium oxide, zinc oxide, indium, tin, antimony, gold, silver, copper, aluminum, nickel, chromium, titanium, iron, and cobalt. Examples thereof include copper iodide, ITO (indium oxide / tin oxide), and ATO (antimony oxide / tin oxide). Such an inorganic conductive substance 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, a zwitterionic antistatic agent, a nonionic antistatic agent, and a single having a cationic, anionic, and zwitterionic ionic conductive group. Examples thereof include an ionic conductive polymer obtained by polymerizing or copolymerizing a polymer.

<Binder>
The antistatic layer preferably contains a polyester resin as a binder. The polyester resin is preferably a resin material containing polyester as a main component (typically, a component that exceeds 50% by mass, preferably 75% by mass or more, for example, 90% by mass or more). The polyester is typically a polyvalent carboxylic acid having two or more carboxyl groups in one molecule (typically a dicarboxylic acid) and a derivative thereof (anhydride, esterified product, halogen of the polyvalent carboxylic acid). Select from one or more compounds (polycarboxylic acid component) selected from compounds (such as compounds) and polyhydric alcohols (typically diols) having two or more hydroxyl groups in one molecule. It is preferable to have a structure in which one kind or two or more kinds of compounds (polyhydric alcohol components) are condensed.

Examples of compounds that can be adopted as the polyvalent carboxylic acid component include oxalic acid, malonic acid, difluoromalonic acid, alkylmalonic acid, succinic acid, tetrafluorosuccinic acid, alkylsuccinic acid, (±) -apple acid, and meso. -Tartrate 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, galactalic acid, pimelic acid, suberic acid, perfluorosveric acid, 3,3,6,6-tetramethylsveric acid, azelaic acid, sebacic acid, perfluoro Aliper dicarboxylic acids such as sebacic acid, brassic acid, dodecyldicarboxylic acid, tridecyldicarboxylic acid, tetradecyldicarboxylic acid; cycloalkyldicarboxylic acid (eg, 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid), Alicyclic dicarboxylic acids such as 1,4- (2-norbornene) dicarboxylic acid, 5-norbornene-2,3-dicarboxylic acid (hymic acid), adamantandicarboxylic acid, spiroheptandicarboxylic acid; phthalic acid, isophthalic acid, dithio Isophthalic acid, methylisophthalic acid, dimethylisophthalic acid, chloroisophthalic acid, dichloroisophthalic acid, terephthalic acid, methylterephthalic acid, dimethylterephthalic acid, chloroterephthalic acid, bromoterephthalic acid, naphthalenedicarboxylic acid, oxofluorangecarboxylic acid, anthracendicarboxylic acid , Biphenyldicarboxylic acid, biphenylenedicarboxylic acid, dimethylbiphenylenedicarboxylic acid, 4,4 "-p-terephenylenedicarboxylic acid, 4,4" -p-quarelphenyldicarboxylic acid, bibenzyldicarboxylic acid, azobenzenedicarboxylic acid, homophthalic acid , Phenylene diacetic acid, phenylenedipropionic acid, naphthalenedicarboxylic acid, naphthalenedipropionic acid, biphenyldiacetic acid, biphenyldipropionic acid, 3,3'-[4,4'-(methylenedi-p-biphenylene) dipropionic acid, Aromatic dicarboxylic acids such as 4,4'-bibenzyldiacetic acid, 3,3'(4,4'-bibenzyl) dipropionic acid, oxydi-p-phenylene diacetic acid; the acid of any of the polyvalent carboxylic acids described above. Anhydrous; the es of any of the polyvalent carboxylic acids mentioned above Tel (eg alkyl ester). It can be a monoester, a diester, or the like. ); An acid halide corresponding to any of the above-mentioned polyvalent carboxylic acids (for example, dicarboxylic acid chloride); and the like.

Preferable examples of the compound that can be adopted as the polyvalent carboxylic acid component include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid and their acid anhydrides; adipic acid, sebacic acid, azelaic acid, and succinic acid. With 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, monoalcohol having 1 to 3 carbon atoms). Esther) and the like.

On the other hand, examples of compounds that can be adopted 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- Diores 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. Can be mentioned. Other examples include alkylene oxide adducts of these compounds (eg, ethylene oxide adducts, propylene oxide adducts, etc.).

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

As the polyester resin, a commercially available trade name "Byronal MD-1480" manufactured by Toyobo Co., Ltd. can be used.

The antistatic layer (topcoat layer) is a resin other than polyester resin as a binder as long as the performance (for example, performance such as antistatic property) of the pressure-sensitive adhesive sheet (surface protective film) disclosed herein is not significantly impaired. (For example, one or more resins selected from acrylic resin, acrylic-urethane resin, acrylic-styrene resin, acrylic-silicone resin, silicone resin, polysilazane resin, polyurethane resin, fluororesin, polyolefin resin, etc.) Can further contain. A preferred embodiment of the technique disclosed herein is when the binder of the antistatic layer is substantially composed of polyester resin only. For example, an antistatic layer in which the ratio of the polyester resin to the binder is 98 to 100% by mass is preferable. The ratio of the binder to the entire antistatic layer can be, for example, 50 to 95% by mass, and usually 60 to 90% by mass is appropriate.

<Glidant>
The antistatic layer (top coat layer) preferably uses a fatty acid amide as a lubricant. By using a fatty acid amide as a lubricant, a further peeling treatment (for example, a treatment of applying a known peeling treatment agent such as a silicone-based peeling agent or a long-chain alkyl-based peeling agent and drying) is performed on the surface of the antistatic layer. Even in the mode in which the treatment is not performed, an antistatic layer (top coat layer) having both sufficient slipperiness and print adhesion can be obtained, which may be a preferable mode. Such an embodiment in which the surface of the antistatic layer is not further peeled can prevent whitening caused by the peeling agent (for example, whitening due to storage under heating and humidifying conditions). It is preferable in that respect. It is also advantageous in terms of solvent resistance.

Specific examples of the fatty acid amide include lauric acid amide, partimate amide, stearic acid amide, bechenic acid amide, hydroxystearic acid amide, oleic acid amide, erucic acid amide, N-oleyl partimate amide, and N-stearyl stealic acid. Amide, N-stearyl oleic acid amide, N-oleyl stealic acid amide, N-stearyl erucate amide, methylol stealic acid amide, methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid Amide, ethylene bishydroxystearic acid amide, ethylene bisbechenic acid amide, hexamethylene bisstearic acid amide, hexamethylene bisbechenic acid amide, hexamethylene hydroxystearic acid amide, N, N'-distearyl adipate amide, N, N ´-Distearyl sevacinic acid amide, ethylene bisoleic acid amide, ethylene biserucate amide, hexamethylene bisoleic acid amide, N, N ′-diorail adipate amide, N, N ′-diorail sevacinic acid amide, m Examples thereof include -xylylene bisstearic acid amide, m-xylylene bishydroxystearic amide, and N, N'-stearyl isophthalic acid amide. One of these lubricants may be used alone, or two or more of these lubricants may be used in combination.

The proportion of the lubricant in the entire antistatic layer can be 1 to 50% by mass, and usually 5 to 40% by mass is appropriate. If the content of the lubricant is too small, the slipperiness tends to decrease. If the content of the lubricant is too high, the print adhesion may decrease.

The technique disclosed herein can be carried out in a mode in which the antistatic layer (topcoat layer) contains another lubricant 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, etc.), mineral wax (montan wax, etc.), higher fatty acid (cerotic acid, etc.), and triglyceride (palmitic acid triglyceride, etc.). Be done. Alternatively, in addition to the wax, a general silicone-based lubricant, fluorine-based lubricant, or the like may be supplementarily contained. The technique disclosed herein can be preferably carried out in a manner substantially free of such silicone-based lubricants, fluorine-based lubricants and the like. However, it contains a silicone compound used for a purpose different from that of the lubricant (for example, as a defoaming agent for a coating material for forming an antistatic layer, which will be described later), as long as the application effect of the technology disclosed herein is not significantly impaired. Does not exclude.

<Crosslinking agent>
The antistatic layer preferably contains an isocyanate-based cross-linking agent as a cross-linking agent. By using the isocyanate-based cross-linking agent, water-soluble polyaniline sulfonic acid, which is an essential component when forming an antistatic layer, can be immobilized in a binder, has excellent water resistance, and further improves print adhesion. The effect can be realized.

As the isocyanate-based cross-linking agent, it is preferable to use a blocked isocyanate-based cross-linking agent that is stable even in an aqueous solution. As a specific example of the blocked isocyanate-based cross-linking agent, an isocyanate-based cross-linking agent that can be used in the preparation of a general pressure-sensitive adhesive layer or antistatic layer (top coat layer) (for example, used in the above-mentioned pressure-sensitive adhesive layer) Isocyanate compounds (isocyanate-based cross-linking agents)) are alcohols, phenols, thiophenols, amines, imides, oximes, lactams, active methylene compounds, mercaptans, imines, ureas, diaryl compounds. , And those blocked with sodium bicarbonate, etc. can be used.

The antistatic layer in the technique disclosed herein includes an antistatic component, an antioxidant, a colorant (pigment, dye, etc.), a fluidity modifier (thixotropic agent, thickener, etc.), and a film-forming agent, if necessary. It may contain additives such as auxiliaries, surfactants (antifoamers, etc.), preservatives and the like.

<Formation of antistatic layer>
The antistatic layer (top coat layer) is a liquid composition (for forming an antistatic layer) in which components such as the conductive polymer component and additives used as necessary are dissolved in an appropriate solvent (water or the like). It can be suitably formed by a method including applying a coating material (antistatic agent composition) to a support film. For example, a method of applying the coating material to the first surface of the support film, drying it, and performing a curing treatment (heat treatment, ultraviolet treatment, etc.) as necessary can be preferably adopted. The NV (nonvolatile content) of the coating material 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 0% by mass). 1% by mass) is appropriate. When forming an antistatic layer having a small thickness, it is preferable that the NV of the coating material is, for example, 0.05 to 0.50% by mass (for example, 0.10 to 0.40% by mass). By using the low NV coating material in this way, a more uniform antistatic layer can be formed.

As the solvent constituting the coating material for forming the antistatic layer, a solvent capable of stably dissolving the forming component of the antistatic layer is preferable. Such a solvent can 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 ethers 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 ethers (eg, ethylene glycol monomethyl ether) , Ethylene glycol monoethyl ether), glycol ethers such as dialkylene glycol monoalkyl ether; etc .; one or more selected from the above can be used. In a preferred embodiment, the solvent of the coating material is water or a mixed solvent containing water as a main component (for example, a mixed solvent of water and ethanol).

<Characteristics of antistatic layer>
The thickness of the antistatic layer is typically 3 to 500 nm, preferably 3 to 100 nm, more preferably 3 to 60 nm). If the thickness of the antistatic layer is too small, it becomes difficult to form the antistatic layer uniformly (for example, the thickness of the antistatic layer varies greatly depending on the location), and therefore, the adhesive sheet (surface protection). The appearance of the film) may be uneven. On the other hand, if it is too thick, it may affect the characteristics of the support film (optical characteristics, dimensional stability, etc.).

In a preferred embodiment of the pressure-sensitive adhesive sheet (surface protective film) disclosed herein, the surface resistance value (Ω / □) measured on the surface of the antistatic layer is 23 ° C. × 50% RH after being left for one day. Both (initially) and after being left at 70 ° C. for 1 week (after storage over time at high temperature) are preferably ^{less than 1.0 × 10 11} and more preferably less than ^{5.0 × 10 10.} More preferably, it is less than ^{3.0 × 10 10.} The pressure-sensitive adhesive sheet exhibiting a surface resistance value within the above range can be suitably used as a pressure-sensitive adhesive sheet used in the processing or transporting process of an article that dislikes static electricity, such as a liquid crystal cell or a semiconductor device. The surface resistance value can be calculated from the surface resistance value measured in an atmosphere of 23 ° C. and 50% RH using a commercially available insulation resistance measuring device.

The adhesive sheet (surface protective film) disclosed herein has a property that the back surface (the surface of the antistatic layer) can be easily printed with a water-based ink or an oil-based ink (for example, using an oil-based marking pen). preferable. For such an adhesive sheet, the identification number and the like of the adherend to be protected are described on the table adhesive sheet in the process of processing, transporting, etc. of the adherend (for example, an optical component) performed with the adhesive sheet attached. Suitable for displaying. Therefore, it is preferable that the adhesive sheet has excellent printability. For example, it is preferable that the solvent is an alcohol-based ink and has high printability with respect to an oil-based ink containing a pigment. Further, it is preferable that the printed ink is difficult to remove due to rubbing or transfer (that is, excellent print adhesion). The pressure-sensitive adhesive sheet disclosed herein also preferably has solvent resistance to such an extent that when the print is modified or erased, the print is wiped with alcohol (for example, ethyl alcohol) without causing a noticeable change in appearance. ..

The pressure-sensitive adhesive sheet (surface protective film) disclosed herein may be implemented in an embodiment including a support film (base material), a pressure-sensitive adhesive layer, and an antistatic layer, as well as other layers. Examples of such an arrangement of the "other layers" include between the first surface (back surface) of the support film and the antistatic layer, between the second surface (front surface) of the support film and the pressure-sensitive adhesive layer, and the like. The layer arranged between the back surface of the support film and the antistatic layer may be, for example, a layer containing an antistatic component (the antistatic layer described above). The layer arranged between the front surface of the support film and the pressure-sensitive adhesive layer may be, for example, an undercoat layer (anchor layer), an antistatic layer, or the like that enhances the anchoring property of the pressure-sensitive adhesive layer with respect to the second surface. The pressure-sensitive adhesive sheet may have a structure in which an antistatic layer is arranged on the front surface of the support film, an anchor layer is arranged on the antistatic layer, and an adhesive layer is arranged on the anchor layer.

The optical member of the present invention is preferably protected by the pressure-sensitive adhesive sheet. Since the adhesive sheet can be used for surface protection applications such as processing, transportation, and shipping, it is useful for protecting the surface of the optical member (polarizing plate, etc.). In particular, after aging treatment (preservation) at a high temperature, the amount of antistatic agent present (transferred) on the surface of the adherend usually decreases due to permeation of the antistatic agent into the adherend (optical member, etc.). Although the optical member of the present invention is protected by the pressure-sensitive adhesive sheet, the pressure-sensitive adhesive sheet (surface protection film) is peeled off from an adherend (polarizing plate, etc.) when the pressure-sensitive adhesive sheet (surface protection film) is peeled off. Compared to the case of peeling immediately after bonding (initial stage), a large increase in the peeling band voltage is not observed, and even after storage over time at high temperature, the peeling charge stability is excellent, so charging is a serious problem. It will be very useful for antistatic in the technical field related to optical and electronic parts.

Hereinafter, examples and the like that specifically show the configuration and effects of the present invention will be described, but the present invention is not limited thereto. The blending contents and characteristic evaluations in Examples and the like were measured as follows. Further, Table 1 shows the physical property values of the (meth) acrylic polymer used in the pressure-sensitive adhesive composition and the blending ratio of the pressure-sensitive adhesive composition, Table 2 shows the blending contents of the antistatic layer, and Table 3 shows the blending contents of the antistatic layer. , The evaluation result of the characteristic is shown.

<Evaluation>
The specific measurement / evaluation method is described below.

<Measurement of weight average molecular weight (Mw)>
The weight average molecular weight (Mw) was measured using a GPC apparatus (HLC-8220 GPC) 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 velocity: 0.6 ml / min
Measurement temperature: 40 ° C
column:
Sample column; TSKguardcolum SuperHZ-H (1) + TSKgel SuperHZM-H (2)
Reference column; TSKgel SuperH-RC (1)
Detector: Differential Refractometer (RI)
The weight average molecular weight was determined by polystyrene conversion value.

<Theoretical value of glass transition temperature>
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 by each monomer.

Formula: 1 / (Tg + 273) = Σ [Wn / (Tgn + 273)]
[In the formula, 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 by each monomer, and n is the type of each monomer. Represents. ] Literature value:
2-Ethylhexyl acrylate (2EHA): -70 ° C
n-Butyl acrylate (BA): -55 ° C.
Acrylic acid (AA): 106 ° C
2-Hydroxyethyl acrylate (HEA): -15 ° C.
4-Hydrobutyl acrylate (HBA): −32 ° C.
N, N-diethylacrylamide (DEAA): 81 ° C.

As literature values, "Synthesis and design of acrylic resin and development of new applications" (published by the Publishing Department of the Central Management Development Center) and "Polymer Handbook" (John Wiley & Sons) were referred to.

<Measurement of peeling band voltage at the initial stage and after high temperature storage over time>
The adhesive sheet is cut into a size of 70 mm in width and 130 mm in length, the separator is peeled off, and then the TAC polarizing plate is attached to an acrylic plate (thickness: 2 mm, width: 70 mm, length: 100 mm) that has been statically eliminated in advance. (SEG1423DU polarizing plate manufactured by Nitto Denko KK, width: 70 mm, length: 100 mm) The surface (TAC surface) was crimped with a hand roller so that one end protruded by 30 mm.

After being left at 23 ° C. × 50% RH for 1 day (initial peeling band voltage) and after being left at 70 ° C. for 1 week (peeling band voltage after high temperature storage over time), as shown in FIG. The sample was set in the position. One end protruding by 30 mm was fixed to an automatic winder and peeled so as to have a peeling angle of 150 ° and a peeling speed of 30 m / min (high-speed peeling). The potential (peeling band voltage: absolute value, kV) on the surface of the polarizing plate generated at this time was measured with a potential measuring machine (KSD-0103, manufactured by Kasuga Electric Works Ltd.) fixed at the center of the polarizing plate. The measurement was performed in an environment of 23 ° C. × 50% RH.

After the adhesive surface of the adhesive layer used for the adhesive sheet is attached (leaved) to the TAC surface (polarizing plate surface) at 23 ° C. × 50% RH for 1 day, the peeling angle is 150 ° and the peeling speed is 30 m / min. The potential (peeling band voltage: kV, absolute value) on the surface of the polarizing plate generated during peeling (high-speed peeling) is preferably less than 0.5 kV, more preferably 0.4 kV or less, and even more preferably 0.3 kV or less. If the peeling band voltage is 0.5 kV or more, for example, the liquid crystal driver or the like may be damaged, which is not preferable.

After the adhesive surface of the adhesive layer used for the adhesive sheet is attached (leaved) to the TAC surface (polarizing plate surface) at 70 ° C. for 1 week, it is peeled off at a peeling angle of 150 ° and a peeling speed of 30 m / min (high-speed peeling). The potential (peeling band voltage: kV, absolute value) on the surface of the polarizing plate generated at the time of) is less than 0.5 kV, more preferably 0.4 kV or less, still more preferably 0.3 kV or less. If the peeling band voltage is 0.5 kV or more, for example, the liquid crystal driver or the like may be damaged, which is not preferable.

<Measurement of shear force>
After cutting the adhesive sheet to a size of 10 mm in width and 100 mm in length and peeling off the separator, the TAC polarizing plate (Nitto Denko Co., Ltd. ^{) so that the adhesive (adhesive) area of the adhesive layer of the adhesive sheet becomes 1 cm 2.} Made by SEG1423DU polarizing plate, width: 25 mm, length: 100 mm), and pulled in the shearing direction at a peeling speed of 0.06 mm / min at 23 ° C., and the maximum load (N / cm ² ) at that time is defined as the shearing force. did.

The shearing force (N / cm ² ) is preferably 10 or more, more preferably 10 to 50, and even more preferably 10 to 40. If the shearing force is within the above range, the force in the shearing direction generated when the adherend tries to curl can be withstood, and the adherend curls without slipping or shifting of the adhesive sheet. Is preferable because it can suppress.

<Measurement of surface resistance at the initial stage and after high temperature storage over time>
The measurement was performed according to JIS-K-6911 using a resistivity meter (manufactured by Mitsubishi Chemical Analytical Co., Ltd., Hiresta UP MCP-HT450 type) in an atmosphere of a temperature of 23 ° C. and a humidity of 50% RH.

The surface resistance value (Ω / □) of the surface of the antistatic layer in the present invention is determined after being left at 23 ° C. × 50% RH for 1 day (initial surface resistance) and after being left at 70 ° C. for 1 week. Both (surface resistance after storage over time at high temperature) are preferably ^{less than 1.0 × 10 11 and more preferably less than 5.0 × 10 10} and even more preferably less than 3.0 × 10 ¹⁰ . be. An adhesive sheet (surface protective film) showing a surface resistance value within the above range is suitably used as an adhesive sheet used in the processing or transporting process of an article that dislikes static electricity, such as a liquid crystal cell or a semiconductor device. obtain.

<Measurement of slipperiness (dynamic friction force)>
Cut the adhesive sheet (surface protection film) to a size of 70 mm in width and 100 mm in length, and attach it to an acrylic plate (manufactured by Mitsubishi Rayon, trade name "Acrylite", thickness: 1 mm, width: 70 mm, length: 100 mm). A test piece was also prepared. The test piece was placed on a horizontally held smooth PET film with the back surface (antistatic layer surface) facing down, and a load of 1.5 kg was placed on the test piece. The test piece carrying the load is attached to a tensile tester using a non-stretchable thread, and the test piece is pulled horizontally under the conditions of a tensile speed of 300 mm / min and a tensile distance of 300 mm at a measurement temperature of 25 ° C. to form a test piece. The average value (n = 3) of the dynamic friction force (N) was obtained.
The slipperiness (dynamic friction force) (N) in the present invention is preferably 5 or less, more preferably 4.5 or less, and further preferably 4 or less. If it is within the above range, it is advantageous in terms of workability if the back surface of the support film (the surface of the antistatic layer) has good slipperiness when handling the adherend to which the adhesive sheet is attached.

<Evaluation of printability (print adhesion)>
After printing on the surface of the antistatic layer using an X stamper manufactured by Shachihata in a measurement environment of 23 ° C. x 50% RH, Nichiban's cellophane tape (registered trademark) is pasted on the printed surface. Then, the peeling is performed under the conditions of a peeling speed of 30 m / min and a peeling angle of 180 °. After that, the surface after peeling is visually observed, and when 50% or more of the printed area is peeled off, x (poor printability), and when 50% or more of the printed area remains without peeling, ○ (good printability). ).

<Preparation method>
Hereinafter, specific methods for preparing (meth) acrylic polymers, pressure-sensitive adhesive compositions, and the like will be described.

<Preparation of (meth) acrylic polymer>
2-Ethylhexyl acrylate (2EHA) 94.5 parts by mass, 4-hydroxyethyl acrylate (HEA) 5.32 parts by mass, acrylic acid in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a cooler. 0.18 parts by mass of (AA), 0.2 parts by mass of 2,2'-azobisisobutyronitrile and 150 parts by mass of ethyl acetate were charged as a polymerization initiator, nitrogen gas was introduced with gentle stirring, and a flask was introduced. The inside liquid temperature was maintained at around 65 ° C. and the polymerization reaction was carried out for 6 hours to prepare a (meth) acrylic polymer solution (40% by mass). The weight average molecular weight of the acrylic polymer was 520,000, and the glass transition temperature (Tg) was −67 ° C.

<Preparation of Adhesive Composition 1>
The above (meth) acrylic polymer solution (40% by mass) is diluted with ethyl acetate to 20% by mass, and 500 parts by mass (solid content 100 parts by mass) of this solution is added to hexa, which is an aliphatic isocyanate compound, as a cross-linking agent. 2 parts by mass (2 parts by mass of solid content) of isocyanurate compound of methylene diisocyanate (Coronate HX manufactured by Nippon Polyurethane Industry Co., Ltd.), 3 parts by mass of dibutyltin dilaurate (1 mass% ethyl acetate solution) as a cross-linking catalyst (solid content 0. 03 parts by mass), 0.2 parts by mass of tetrabutylammonium hexafluorophosphate (manufactured by Tokyo Kasei Kogyo Co., Ltd., TBA, melting point 245 ° C.) as an ionic compound, and an organopolysiloxane having an oxyalkylene chain as an ethylene oxide group-containing compound (03 parts by mass). 0.2 parts by mass of KF-6020) manufactured by Shin-Etsu Chemical Industry Co., Ltd. was added, and the mixture was mixed and stirred to prepare a pressure-sensitive adhesive composition 1 (solution).

<Preparation of aqueous solution for antistatic layer (back treatment agent A)>
Polyaniline MD-1480 (25% aqueous solution, manufactured by Toyo Boseki Co., Ltd.) as a binder, polyaniline sulfonic acid (aquaPASS, weight average molecular weight 40,000, manufactured by Mitsubishi Rayon Co., Ltd.) as a conductive polymer, and hexamethylene blocked with diisopropylamine as a cross-linking agent. As an isocyanurate of diisocyanate and lubricant, oleic acid amide is used as a mixed solvent of water / ethanol (1/3), binder is 100 parts by mass in solid content, conductive polymer is 75 parts by mass in solid content, and cross-linking agent is solid. 10 parts by mass of the amount and 30 parts by mass of the lubricant were added, and the mixture was stirred for about 20 minutes and sufficiently mixed. In this way, an aqueous solution for an antistatic layer having an NV of about 0.4% was prepared.

<Preparation of aqueous solution for antistatic layer (back treatment agent B)>
Polyaniline sulfonic acid (aquaPASS, weight average molecular weight 40,000, manufactured by Mitsubishi Rayon) as a binder, polyester resin byronal MD-1480 (25% aqueous solution, manufactured by Toyo Boseki Co., Ltd.) as a binder, and hexamethylene blocked with diisopropylamine as a cross-linking agent. The isocyanurate of diisocyanate is mixed with water / ethanol (1/3), the binder is 100 parts by mass in solid content, the conductive polymer is 75 parts by mass in solid content, and the cross-linking agent is 10 parts by mass in solid content. In addition, it was stirred for about 20 minutes and mixed well. In this way, an aqueous solution for an antistatic layer having an NV of about 0.4% was prepared.

<Preparation of aqueous solution for antistatic layer (back treatment agent C)>
Polyester resin byronal MD-1480 (25% aqueous solution, manufactured by Toyo Boseki Co., Ltd.) as a binder, poly (3,4-ethylenedioxythiophene) (PEDOT) 0.5% and polystyrene sulfonate (weight average molecular weight 150,000) as a conductive polymer An aqueous solution containing 0.8% (PSS) (Bytron P, manufactured by HC Stark), an isocyanurate of hexamethylene diisocyanate blocked with diisopropylamine as a cross-linking agent, and a mixed solvent of water / ethanol (1/1). 100 parts by mass of the binder, 50 parts by mass of the conductive polymer by the solid content, and 10 parts by mass of the cross-linking agent by the solid content were added thereto, and the mixture was stirred for about 20 minutes and sufficiently mixed. In this way, an aqueous solution for an antistatic layer having an NV of about 0.4% was prepared.

<Preparation of aqueous solution for antistatic layer (back treatment agent D)>
Polyester resin byronal MD-1480 (25% aqueous solution, manufactured by Toyo Boseki Co., Ltd.) as a binder, polyaniline sulfonic acid (aquaPASS, weight average molecular weight 40,000, manufactured by Mitsubishi Rayon Co., Ltd.) as a conductive polymer mixed with water / ethanol (1/3) To the solvent, 100 parts by mass of the binder was added in terms of solid content, and 75 parts by mass of the conductive polymer was added in terms of solid content, and the mixture was stirred for about 20 minutes and sufficiently mixed. In this way, an aqueous solution for an antistatic layer having an NV of about 0.4% was prepared.

<Manufacturing of support film with antistatic layer>
The antistatic layer (back surface treatment) is applied to a transparent polyethylene terephthalate (PET) film (polyester film: support film) having a thickness of 38 μm, a width of 30 cm, and a length of 40 cm in which one surface (first surface) is corona-treated. An aqueous solution of any of the agents A to D) was applied so that the thickness after drying was 30 nm. The coated material was heated to 130 ° C. for 1 minute and dried to prepare a support film with an antistatic layer having an antistatic layer on the first surface of the PET film.

<Example 1>
<Making an adhesive sheet>
The pressure-sensitive adhesive composition 1 (solution) was applied to the surface of the support film with an antistatic layer opposite to the antistatic layer, and heated at 130 ° C. for 1 minute to form a pressure-sensitive adhesive layer having a thickness of 15 μm. .. Next, a silicone-treated surface of a polyethylene terephthalate film (thickness 25 μm), which is a separator whose one side was treated with silicone, was bonded to the surface of the pressure-sensitive adhesive layer to prepare a pressure-sensitive adhesive sheet (surface protective film).

<Examples 2 to 14 and Comparative Examples 1 to 3>
Based on the blending ratios in Tables 1 and 2, adhesive sheets were prepared in the same manner as in Example 1. The blending amount in Table 1 indicates the solid content.

According to the above evaluation method, the peeling band voltage, shearing force, surface resistance value, slipperiness, and print adhesion after the initial and high temperature aging of the produced adhesive sheet were evaluated. The results obtained are shown in Table 3.

The abbreviations in Tables 1 and 2 will be described below.
2EHA: 2-Ethylhexyl acrylate BA: n-Butyl acrylate AA: Acrylic acid (carboxyl group-containing (meth) acrylic monomer)
HEA: 2-Hydroxyethyl acrylate (hydroxyl group-containing (meth) acrylic monomer)
HBA: 4-Hydroxybutyl acrylate (hydroxyl group-containing (meth) acrylic monomer)
DEAA: N, N-diethylacrylamide C / L: Aromatic isocyanate compound, trimethylolpropane / tolylene diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name: Coronate L)
C / HX: Isocyanurate compound of aliphatic isocyanate compound and hexamethylene diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name: Coronate HX)
TMHA: trimethylhexyl ammonium bistrifluoromethanesulfonylimide (melting point = 35 ° C.) (Ionic compound manufactured by Kishida Chemical Co., Ltd.)
HP: 1-hexylpyridinium hexafluorophosphate (melting point = 45 ° C.) (Ionic compound manufactured by Kishida Chemical Co., Ltd.)
BMP: 1-Butyl-4-methylpyridinium hexafluorophosphate (melting point = 42 ° C) (manufactured by Tokyo Chemical Industry Co., Ltd., ionic compound)
MEIM: 1-methyl-3-ethylimidazolium hexafluorophosphate (melting point = 61 ° C) (manufactured by Tokyo Chemical Industry Co., Ltd., ionic compound)
BP: 1-Butylpyridinium hexafluorophosphate (melting point = 75 ° C) (manufactured by Tokyo Chemical Industry Co., Ltd., ionic compound)
TBA: Tetrabutylammonium hexafluorophosphate (melting point = 245 ° C) (manufactured by Tokyo Chemical Industry Co., Ltd., ionic compound)
KF6020: Organopolysiloxane having an oxyalkylene chain (HLB value 4) (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KF-6020)
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) (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KF-355A)
EO group-containing compound: Ethylene oxide group-containing compound (compound having an aoxyalkylene chain)
PEDOT: Conductive polymer, poly (3,4-ethylenedioxythiophene)
PSS: Conductive polymer, polystyrene sulfonate

注)表３中の「＞１Ｅ＋１３」とは、抵抗率計で測定できる上限値を超えていたことを示す。

Note) “> 1E + 13” in Table 3 indicates that the upper limit value that can be measured by the resistivity meter has been exceeded.

From the results in Table 3 above, it was confirmed that in all the examples, the peeling band voltage (peeling charge stability after high temperature storage over time) was excellent after high temperature storage over time (after 1 week at 70 ° C.). On the other hand, in Comparative Examples 1 and 2 containing no ionic compound, it was confirmed that the peeling zone voltage was high from the initial stage and remained high even after storage at high temperature for a long time. Further, in Comparative Example 3, although it contained an ionic compound, it was confirmed that the surface resistance value after storage at high temperature for a long time was inferior and the peeling band voltage after storage at high temperature for a long time was also inferior. Moreover, the shearing force was also inferior in all the comparative examples.

Further, from the results in Table 3, a desired raw material (conductive polymer component: polyaniline sulfonic acid, binder: polyester resin, and cross-linking agent: isocyanate-based cross-linking agent) was blended as the antistatic layer (antistatic agent composition). In the adhesive sheets of Examples 1 to 5, 7 to 11 and 13 having an antistatic layer using the back treatment agent A produced in the above process, all of the surface resistance, slipperiness and print adhesion caused by the antistatic layer. It satisfied the evaluation items of. On the other hand, for the antistatic layer using the back treatment agents B to D manufactured without blending a part of the desired raw materials, all the evaluation items of surface resistance, slipperiness and print adhesion due to the antistatic layer It was confirmed that there was nothing that satisfied.

1 Potentiometric titration 2 Adhesive sheet 3 Polarizing plate 4 Acrylic plate 5 Fixing base

Claims (4)

On one surface of the support film, the pressure-sensitive adhesive sheet having an adhesive layer formed from the pressure-sensitive adhesive composition,
An antistatic layer is provided on one side of the support film opposite to the pressure-sensitive adhesive layer.
The pressure-sensitive adhesive composition contains a (meth) acrylic polymer, a compound having an oxyalkylene chain, and an ionic compound having an organic cation that is solid at room temperature (25 ° C.).
The (meth) acrylic polymer contains a carboxyl group-containing (meth) acrylic monomer as a monomer component in an amount of 0.01% by mass or more and less than 0.3% by mass with respect to the total amount of the monomer components.
The peeling band voltage at a peeling speed of 30 m / min after sticking the adhesive surface of the pressure-sensitive adhesive layer to the TAC surface at 70 ° C. for 1 week is less than 0.5 kV (absolute value).
The antistatic layer is characterized by being formed from an antistatic agent composition containing polyaniline sulfonic acid as a conductive polymer component, polyester resin as a binder, fatty acid amide as a lubricant, and an isocyanate-based cross-linking agent as a cross-linking agent. Adhesive sheet to do. The pressure-sensitive adhesive sheet according to claim 1, wherein the compound having an oxyalkylene chain is an organopolysiloxane having an oxyalkylene chain. The pressure-sensitive adhesive sheet according to claim 1 or 2, wherein the (meth) acrylic polymer is a (meth) acrylic polymer having a hydroxyl group and a carboxyl group. An optical member that is protected by the adhesive sheet according to any one of claims 1 to 3.

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