CN106232755B - Adhesive sheet and optical member - Google Patents

Abstract

The invention provides an adhesive sheet which can suppress the peeling electrification voltage to be low and has excellent peeling electrification stability after storage at high temperature over time when the adhesive sheet is peeled from an adherend in processing (manufacturing) in a state of being adhered to the adherend, in transportation, or in a state of being exposed to high temperature. The adhesive sheet of the present invention is an adhesive sheet having an adhesive layer formed from an adhesive composition on one or both surfaces of a support film, and is characterized in that the absolute value of a peeling electrification voltage at a peeling speed of 30 m/min after the adhesive surface of the adhesive layer is adhered to a TAC surface at 70 ℃ for 1 week is less than 0.5 kV.

Description

Adhesive sheet and optical member

Technical Field

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 useful as a surface protective film for protecting the surface of an optical member used in a liquid crystal display or the like, such as a polarizing plate, a wavelength plate, a retardation plate, an optical compensation film, a reflection sheet, a luminance enhancement film, or the like.

Background

In recent years, when transporting optical components and electronic components or mounting the components on a printed circuit board, the components are transported in a state of being packaged in a predetermined sheet or in a state of being adhered with an adhesive tape. Among them, the surface protective film is widely used particularly in the fields of optics and electronic parts.

A surface protective film is generally bonded to an adherend (protected object) by an adhesive applied to a support film side, and is used for the purpose of preventing damage and dirt generated 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 wavelength plate to a liquid crystal cell with an adhesive. The surface protective film is bonded to these optical members with an adhesive, and can prevent damage and dirt from occurring during processing and transportation of an adherend. Further, the surface protective film is peeled and removed at a stage where it becomes unnecessary.

In addition, when the surface protective film is peeled from the adherend after the time-lapse treatment (storage) during processing and transportation, the surface protective film and the optical member are generally made of a plastic material, and therefore, the surface protective film and the optical member have high electrical insulation properties, and static electricity is generated during friction and peeling. In particular, after the treatment (storage) at a high temperature with time, the antistatic agent is less likely to be present (transferred) on the surface of the adherend due to the penetration of the antistatic agent into the adherend (polarizing plate or the like), and when the surface protective film is peeled from the adherend (polarizing plate or the like), it is confirmed that the peeling electrification voltage is increased and the peeling electrification stability is inferior as compared with immediately after the lamination, static electricity is generated when the surface protective film is peeled from the adherend (polarizing plate or the like), and if a voltage is applied to the liquid crystal in a state where the static electricity generated at that time remains, the orientation of the liquid crystal molecules is lost, and a defect may occur in the panel. When the adherend is processed in a state where the surface protective film is bonded thereto, high-temperature treatment may be performed,

documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 9-165460

Disclosure of Invention

Technical problem to be solved by the invention

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

Means for solving the problems

That is, the adhesive sheet of the present invention is an adhesive sheet having an adhesive layer made of an adhesive composition on one surface or both surfaces of a support film, and is characterized in that the absolute value of a peeling electrification voltage at a peeling speed of 30 m/min after the adhesive surface of the adhesive layer is attached to a TAC surface at 70 ℃ for 1 week is less than 0.5 kV.

The adhesive sheet of the present invention is preferably: the adhesive composition contains a compound having an oxyalkylene chain and an ionic compound having an organic cation which is solid at ordinary temperature (25 ℃).

The adhesive sheet of the present invention is preferably: the compound having an oxyalkylene chain is an organopolysiloxane having an oxyalkylene chain.

The adhesive sheet of the present invention is preferably: the adhesive composition contains a (meth) acrylic polymer having a hydroxyl group and a carboxyl group.

The adhesive sheet of the present invention is preferably: the antistatic layer is formed from an antistatic agent composition containing polyaniline sulfonic acid as a conductive polymer component, a polyester resin as a binder, and an isocyanate-based crosslinking agent as a crosslinking agent.

The adhesive sheet of the present invention is preferably: the antistatic agent composition further contains a fatty acid amide as a lubricant.

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

Effects of the invention

The adhesive sheet of the present invention is useful because it can suppress the peeling electrification voltage to be low and has excellent peeling electrification stability after storage at high temperatures over time when the adhesive sheet is peeled from an adherend in processing (manufacturing) in a state of being adhered to the adherend, in transportation, or in a case of being exposed to high temperatures.

Drawings

FIG. 1 is a schematic view of a potential measuring section.

Detailed Description

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

< integral Structure of adhesive sheet (surface protective film) >

The adhesive sheet (surface protective film) of the present invention is generally referred to as an adhesive sheet, an adhesive tape, an adhesive label, an adhesive film, or the like, and is particularly suitable as a surface protective film for protecting the surface of an optical member (for example, an optical member used as a component of a liquid crystal display panel such as a polarizing plate or a wavelength plate) during processing and transportation of the optical member. The adhesive layer in the adhesive sheet is typically formed continuously, but is not limited to the above form, and may be formed in a regular or random pattern such as dots or stripes, for example. The adhesive sheet disclosed herein may be in the form of a roll or a sheet.

Typical examples of the adhesive sheet (surface protective film) disclosed herein include an adhesive sheet having an adhesive layer on one or both surfaces of a support film (substrate), and an adhesive sheet having an antistatic layer provided on one surface of the support film and an adhesive layer provided on the surface opposite to the antistatic layer of the support film. The adhesive sheet is used by attaching the adhesive layer to an adherend (a surface of an optical member to be protected, for example, a polarizing plate). The pressure-sensitive adhesive sheet before use (i.e., before attachment to an adherend) may be in the following form: the surface of the adhesive layer (the surface to be adhered to an adherend) is protected by a release liner having a release surface on at least the adhesive layer side. Alternatively, the adhesive sheet may be in the form of: when the adhesive layer is wound in a roll shape, the adhesive layer comes into contact with the back surface (the surface of the antistatic layer) of the support film, and the surface thereof is protected.

< supporting film >

The adhesive sheet of the present invention is characterized in that the adhesive sheet has an adhesive layer made of an adhesive composition on one side or both sides of a support film. The resin material constituting the support film may be used without particular limitation, and for example, a material excellent in characteristics such as transparency, mechanical strength, thermal stability, moisture barrier property, isotropy, flexibility, and dimensional stability is preferably used. In particular, the support film is flexible, and therefore, the adhesive composition can be applied by a roll coater or the like, and can be wound into a roll form, which is useful.

As the support film (substrate), for example, polyester polymers such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate; cellulose polymers such as diacetylcellulose and triacetylcellulose; a polycarbonate-series polymer; a plastic film made of a resin material containing an acrylic polymer such as polymethyl methacrylate as a main resin component (a main component in the resin component, typically 50 mass% or more) is used as the support film. Other examples of the resin material include: styrene polymers such as polystyrene and acrylonitrile-styrene copolymer; olefin polymers such as polyethylene, polypropylene, polyolefins having a cyclic or norbornene structure, and ethylene-propylene copolymers; a vinyl chloride polymer; polyamide polymers such as nylon 6, nylon 66 and aromatic polyamide are used as the resin material. Still other examples of the resin material include: imide polymers, sulfone polymers, polyether ether ketone polymers, polyphenylene sulfide polymers, vinyl alcohol polymers, vinylidene chloride polymers, vinyl butyral polymers, arylate polymers, polyoxymethylene polymers, epoxy polymers, and the like. The support film may be a mixture of 2 or more of the above polymers.

As the support film, a plastic film formed of a transparent thermoplastic resin material can be preferably used. Among the plastic films, a polyester film is more preferably used. Here, the polyester film is a film containing, as a main resin component, a polymer material (polyester resin) having a main skeleton based on an ester bond, such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), or polybutylene terephthalate. The polyester film has characteristics preferable as a support film of an adhesive sheet, such as excellent optical characteristics and dimensional stability, and has a property of being easily charged.

Various additives such as an antioxidant, an ultraviolet absorber, a plasticizer, a colorant (such as a pigment and a dye) may be blended as necessary with the resin material constituting the support film. The first surface (the surface on which the antistatic layer is provided) of the support film may be subjected to a known or conventional surface treatment such as corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, and coating with a primer. Such a surface treatment may be, for example, a treatment for improving adhesion between the support film and the antistatic layer. It is preferable to use a surface treatment for introducing a polar group such as a hydroxyl group (-OH group) into the surface of the support film. The second surface (the surface on the side where the adhesive layer is formed) of the support film may be subjected to the same surface treatment as described above. The surface treatment may be a treatment for improving the adhesion between the film and the adhesive layer (the anchoring property of the adhesive layer).

In the case where the pressure-sensitive adhesive sheet of the present invention has an antistatic layer on a support film and an antistatic function, a plastic film further subjected to antistatic treatment may be used as the support film. The use of the support film is preferable because the electrification of the pressure-sensitive adhesive sheet itself after peeling can be suppressed. The support film is a plastic film, and the plastic film is subjected to antistatic treatment, whereby an adhesive sheet having reduced electrification of the adhesive sheet itself and excellent antistatic ability against an adherend can be obtained. Here, the method of imparting the antistatic function is not particularly limited, and conventionally known methods can be used, and examples thereof include: a method of coating an antistatic resin comprising an antistatic agent and a resin component, a method of coating a conductive resin comprising a conductive polymer and a conductive substance, a method of vapor deposition or plating of a conductive substance, and a method of incorporating an antistatic agent or the like.

The thickness of the support film is usually 5 to 200 μm, preferably about 10 to 100 μm. When the thickness of the support film is within the above range, workability of bonding to an adherend and workability of peeling from an adherend are excellent, and therefore, the support film is preferable.

< adhesive composition >

The adhesive sheet (surface protective film) of the present invention has the adhesive layer, the adhesive layer is a layer formed of an adhesive composition, and the adhesive composition can be used without particular limitation as long as it has adhesiveness, and for example, an acrylic adhesive, a urethane adhesive, a synthetic rubber adhesive, a natural rubber adhesive, a silicone adhesive, and the like, among which at least 1 selected from the group consisting of an acrylic adhesive, a urethane adhesive, and a silicone adhesive is more preferable, and an acrylic adhesive using a (meth) acrylic polymer is particularly preferable.

The adhesive composition used in the present invention preferably contains a (meth) acrylic polymer having a hydroxyl group and a carboxyl group. By using the (meth) acrylic polymer having a hydroxyl group and a carboxyl group, the hydroxyl group can be easily controlled to be crosslinked, and the carboxyl group can increase a shear force or prevent an increase in adhesive force with time, which is a preferable embodiment. In the present invention, the (meth) acrylic polymer means an acrylic polymer and/or a methacrylic polymer, and the (meth) acrylate means an acrylate and/or a methacrylate.

The (meth) acrylic polymer may use a hydroxyl group-containing (meth) acrylic monomer as a monomer component. By using the hydroxyl group-containing (meth) acrylic monomer as a monomer component, it is easy to control crosslinking and the like of the adhesive composition, and further, it is easy to control the balance between improvement of wettability by flow and cohesive force and shear force of the adhesive (layer). Further, unlike a carboxyl group, a sulfonate group, and the like, which generally function as a crosslinking site, a hydroxyl group has a moderate interaction with an ionic compound or the like as an antistatic agent, and thus can be suitably used in terms of antistatic properties.

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

Examples of the hydroxyl group-containing (meth) acrylic monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, 4-hydroxymethylcyclohexyl (4-hydroxymethylcyclohexyl) methyl acrylate, and N-methylol (meth) acrylamide.

Further, the (meth) acrylic polymer can control an increase in adhesive force with time of the adhesive sheet (adhesive agent layer) by using the carboxyl group-containing (meth) acrylic monomer as a monomer component, and is excellent in removability, adhesion force increase prevention property, and workability, and also excellent in cohesive force and shear force of the adhesive agent layer.

The adhesive sheet of the present invention is preferably: the carboxyl group-containing (meth) acrylic monomer is contained in an amount of 0.01 mass% or more and less than 0.5 mass%, more preferably 0.01 mass% or more and less than 0.4 mass%, still more preferably 0.01 mass% or more and less than 0.3 mass%, and most preferably 0.01 mass% or more and less than 0.2 mass%, based on the total amount of the monomer components constituting the (meth) acrylic polymer. When the amount is within the above range, the increase in the adhesive strength with time can be suppressed, and the removability, the prevention of the increase in the adhesive strength, and the workability are excellent. In addition, not only the adhesive layer has excellent cohesive force, but also excellent shear force, is preferred. Further, it is preferable that the ionic dissociation is induced by an appropriate interaction with a solid ionic compound, and a good antistatic property can be exhibited. Here, if an excessive amount of an acid functional group such as a carboxyl group having a large polar action is present, when an ionic compound as an antistatic agent is blended, the interaction between the acid functional group such as a carboxyl group and the ionic compound is strongly exerted, and therefore, ion conduction is inhibited, and the conductive 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, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, 2- (meth) acryloyloxyethylhexahydrophthalic acid, 2- (meth) acryloyloxypropylhexahydrophthalic acid, 2- (meth) acryloyloxyethylphthalic acid, 2- (meth) acryloyloxyethylsuccinic acid, 2- (meth) acryloyloxyethylmaleic acid, carboxypolycaprolactone mono (meth) acrylate, 2- (meth) acryloyloxyethyltetrahydrophthalic acid, and the like.

The adhesive composition used in the present invention contains the (meth) acrylic polymer, and is not particularly limited as long as it is a (meth) acrylic polymer having adhesiveness, and as a main component of the monomer component, a (meth) acrylic monomer having an alkyl group with 1 to 14 carbon atoms is preferably used, and a (meth) acrylic monomer having an alkyl group with 4 to 14 carbon atoms is more preferably used. As the (meth) acrylic monomer, 1 or 2 or more species may be used as a main component. Here, the term "main component" means that the mixing 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, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, isobutyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-dodecyl (meth) acrylate, n-tridecyl (meth) acrylate, and n-tetradecyl (meth) acrylate.

When the pressure-sensitive adhesive sheet of the present invention is used as a surface protective film, examples of suitable monomers include (meth) acrylates having an alkyl group having 6 to 14 carbon atoms, such as hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-dodecyl (meth) acrylate, n-tridecyl (meth) acrylate, and n-tetradecyl (meth) acrylate. By using a (meth) acrylate having an alkyl group having 6 to 14 carbon atoms, the adhesion to an adherend can be easily controlled to be low, and the removability is excellent.

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

Further, as the other polymerizable monomer component, for the reason that the balance of the adhesive properties is easily obtained, a polymerizable monomer for adjusting the glass transition temperature and the releasability of the (meth) acrylic polymer may be used so that the Tg becomes 0 ℃ or lower (usually-100 ℃ or higher) within the range not to impair the effect of the present invention.

The polymerizable monomer other than the hydroxyl group-containing (meth) acrylic monomer, the carboxyl group-containing (meth) acrylic monomer, and the (meth) acrylic monomer having an alkyl group having 1 to 14 carbon atoms used in the (meth) acrylic polymer is not particularly limited as long as the characteristics of the present invention are not impaired. For example, a component for improving cohesive force and heat resistance such as a cyano group-containing monomer, a vinyl ester monomer, or an aromatic vinyl monomer, a component for improving adhesion (bonding) force or having a functional group which functions as a crosslinking base point such as an amide group-containing monomer, an imide group-containing monomer, an amino group-containing monomer, an epoxy group-containing monomer, N-acryloylmorpholine, or a vinyl ether monomer, can be suitably used. These polymerizable monomers may be used alone, or 2 or more kinds may be mixed and used.

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

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

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

Examples of the amide group-containing monomer include acrylamide, methacrylamide, diethylacrylamide, N-vinylpyrrolidone, N-dimethylacrylamide, N-dimethylmethacrylamide, N-diethylacrylamide, N-diethylmethacrylamide, N' -methylenebisacrylamide, N-dimethylaminopropylacrylamide, N-dimethylaminopropylmethacrylamide, diacetoneacrylamide, 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-dimethylaminoethyl (meth) acrylate, and N, N-dimethylaminopropyl (meth) acrylate.

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

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

In the present invention, the polymerizable monomer other than the carboxyl group-containing (meth) acrylic monomer, the hydroxyl group-containing (meth) acrylic monomer, and 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, of the total amount of monomer components (all monomer components) constituting the (meth) acrylic polymer. By using the other polymerizable monomer within the above range, good interaction with the ionic compound used as the antistatic agent and good removability can be appropriately adjusted.

The weight average molecular weight of the (meth) acrylic polymer is 10 to 500 ten thousand, preferably 20 to 400 ten thousand, and more preferably 30 to 300 ten thousand. When the weight average molecular weight is less than 10 ten thousand, the cohesive force of the adhesive composition becomes small, and thus residual glue tends to be generated. On the other hand, when the weight average molecular weight exceeds 500 ten thousand, the fluidity of the polymer decreases, the wetting with an adherend (for example, a polarizing plate as an optical member or the like) becomes insufficient, and foaming tends to occur between the adherend and the pressure-sensitive adhesive composition layer of the pressure-sensitive adhesive sheet. Here, the weight average molecular weight is measured by GPC (gel permeation chromatography).

The glass transition temperature (Tg) of the (meth) acrylic polymer is preferably 0 ℃ or lower, more preferably-10 ℃ or lower, and still more preferably-20 ℃ or lower (usually-100 ℃ or higher). When the glass transition temperature is higher than 0 ℃, the polymer is difficult to flow, and for example, wetting of an adherend (for example, a polarizing plate or the like as an optical member) becomes insufficient, and there is a tendency that the polymer causes foaming between the adherend and the adhesive composition layer of the adhesive sheet. In particular, by setting the glass transition temperature to-61 ℃ or lower, an adhesive composition excellent in wettability to an adherend and light peelability can be easily obtained. Here, the glass transition temperature of the (meth) acrylic polymer can be adjusted within the above range by appropriately changing the monomer components and the composition ratio used.

The method for polymerizing the (meth) acrylic polymer used in the present invention is not particularly limited, and polymerization can be carried out by a known method such as solution polymerization, emulsion polymerization, bulk polymerization, or suspension polymerization, and particularly, solution polymerization is a more preferable mode from the viewpoint of workability and properties such as low staining property to an adherend. The polymer obtained may be a random copolymer, a block copolymer, an alternating copolymer, a graft copolymer, or the like.

The pressure-sensitive adhesive sheet of the present invention may contain an antistatic agent (antistatic component), and the antistatic agent may contain an ionic compound, particularly an ionic compound having an organic cation which is solid at room temperature (25 ℃). The inclusion of the ionic compound having an organic cation which is solid at room temperature (25 ℃) is a preferable embodiment because the ionic compound has high stability when heat at room temperature or higher is applied and the peeling electrification stability after storage at high temperature is excellent.

As the ionic compound having an organic cation which is solid at ordinary temperature (25 ℃), it is preferable to use an ionic compound containing an organic cation component represented by the following formulae (A) to (E) and an anion component. By using an ionic compound having such cations, a substance having more excellent antistatic performance can be obtained.

[ CHEM 1 ]

R in the formula (A)_aA hydrocarbon group having 4 to 20 carbon atoms, which may be a functional group in which a part of the hydrocarbon group is substituted with a hetero atom, R_bAnd R_cThe same or different, represents 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. However, when the nitrogen atom contains a double bond, R is not present_c。

R in the formula (B)_dRepresents 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, R_e、R_fAnd R_gThe same or different, represents 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 in the formula (C)_hRepresents 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, R_i、R_jAnd R_kThe same or different, represents 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, R_l、R_m、R_nAnd R_oThe same or different alkyl groups represent alkyl groups having 1 to 20 carbon atoms, and a part of the alkyl groups may be substituted with hetero atoms. However, when Z is a sulfur atom, R is absent_o。

R in the formula (E)_pThe hydrocarbon group may be a functional group in which a part of the hydrocarbon group is substituted with a hetero atom.

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, and a morpholinium cation.

Specific examples thereof include 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-dimethylpyrrolidinium cation, 1-ethyl-1-methylpyrrolidinium cation, 1-methyl-1-propylpyrrolidinium cation, 1-methyl-1-butylpyrrolidinium cation, 1-methyl-1-pentylpyrrolidinium cation, 1-methyl-1-hexylpyrrolidinium cation, and the like, 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-dipropylpyrrolidinium cation, 1-propyl-1-butylpyrrolidinium cation, 1-dibutylpyrrolidinium cation, pyrrolidinium-2-one cation, 1-propylpiperidinium cation, 1-pentylpiperidinium cation, 1-dimethylpiperidinium cation, 1-methyl-1-ethylpiperidinium cation, 1-ethyl-piperidinium cation, 1-ethyl-1-propylpyrrolidinium cation, 1-propylpiperidinium cation, 1-ethylpiperidinium cation, 1-, 1-methyl-1-propylpiperidinium cation, 1-methyl-1-butylpiperidinium cation, 1-methyl-1-pentylpiperidinium cation, 1-methyl-1-hexylpiperidinium cation, 1-methyl-1-heptylpiperidinium cation, 1-ethyl-1-propylpiperidinium cation, 1-ethyl-1-butylpiperidinium cation, 1-ethyl-1-pentylpiperidinium cation, 1-ethyl-1-hexylpiperidinium cation, 1-ethyl-1-heptylpiperidinium cation, 1-dipropylpiperidinium cation, 1-propyl-1-butylpiperidinium cation, the like, or a salt thereof, 1, 1-dibutylpiperidinium cation, 2-methyl-1-pyrroline cation, 1-ethyl-2-phenylindole cation, 1, 2-dimethylindole cation, 1-ethylcarbazole cation, N-ethyl-N-methylmorpholinium cation, and the like.

Examples of the cation represented by the formula (B) include imidazolinium cations, tetrahydropyrimidinium cations, and dihydropyrimidinium cations.

Specific examples thereof include a 1, 3-dimethylimidazolinium cation, a 1, 3-diethylimidazolinium cation, a 1-ethyl-3-methylimidazolinium cation, a 1-butyl-3-methylimidazolinium cation, a 1-hexyl-3-methylimidazolinium cation, a 1-octyl-3-methylimidazolinium cation, a 1-decyl-3-methylimidazolinium cation, a 1-dodecyl-3-methylimidazolinium cation, a 1-tetradecyl-3-methylimidazolinium cation, a 1, 2-dimethyl-3-propylimidazolinium cation, a 1-ethyl-2, 3-dimethylimidazolinium cation, a salt thereof, and a salt thereof, 1-butyl-2, 3-dimethylimidazolinium cation, 1-hexyl-2, 3-dimethylimidazolinium cation, 1- (2-methoxyethyl) -3-methylimidazolinium 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, 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-dihydropyrimidinium cation, 1,2,3, 4-tetramethyl-1, 6-dihydropyrimidinium cation, and the like.

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

Specific examples thereof include a 1-methylpyrazolium cation, a 3-methylpyrazolium cation, a 1-ethyl-2, 3, 5-trimethylpyrazolium cation, a 1-propyl-2, 3, 5-trimethylpyrazolium cation, a 1-butyl-2, 3, 5-trimethylpyrazolium cation, a 1-ethyl-2, 3, 5-trimethylpyrazolinium cation, a 1-propyl-2, 3, 5-trimethylpyrazolinium cation, and a 1-butyl-2, 3, 5-trimethylpyrazolinium cation.

Examples of the cation represented by the formula (D) include tetraalkylammonium cations, trialkylsulfonium cations, tetraalkylphosphonium cations, and groups in which a part of the alkyl group is substituted with an alkenyl group, an alkoxy group, or an epoxy group.

Specific examples thereof include tetramethylammonium cation, tetraethylammonium cation, tetrabutylammonium cation, tetrapentylammonium cation, tetrahexylammonium cation, tetraheptylammonium cation, triethylmethylammonium cation, tributylethylammonium cation, trimethyldecylammonium cation, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium cation, glycidyltrimethylammonium cation, trimethylsulfonium cation, triethylsulfonium cation, tributylsulfonium cation, trihexylsulfonium cation, diethylmethylsulfinium cation, dibutylethylsulfonium cation, dimethyldecylsulfonium cation, tetramethylphosphonium cation, tetraethylphosphonium cation, tetrabutylphosphonium cation, tetrahexylphosphonium cation, tetraoctylphosphonium cation, triethylmethylphosphonium cation, tributylethylphosphonium cation, tetrabutylphosphonium cation, tetramethylphosphonium cation, and, Trimethyldecylphosphonium cation, diallyldimethylammonium cation, tributyl- (2-methoxyethyl) phosphonium cation, and the like. Among them, asymmetric tetraalkylammonium cations such as triethylmethylammonium cation, tributylethylammonium cation, trimethyldecylammonium cation, diethylmethylsulfinium cation, dibutylethylsulfonium cation, dimethyldecylsulfonium cation, triethylmethylphosphonium cation, tributylethylammonium cation, and trimethyldecylphosphonium cation, trialkylsulfinium cation, tetraalkylphosphonium cation, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium cation, glycidyltrimethylammonium cation, diallyldimethylammonium cation, N-dimethyl-N-ethyl-N-propylammonium cation, N-dimethyl-N-ethyl-N-butylammonium cation, N-dimethyl-N-ethyl-N-pentylammonium cation, and the like are preferably used, N, N-dimethyl-N-ethyl-N-hexylammonium cation, N-dimethyl-N-ethyl-N-heptylammonium cation, N-dimethyl-N-ethyl-N-nonylammonium cation, N-dimethyl-N, N-dipropylammonium cation, N-diethyl-N-propyl-N-butylammonium cation, N-dimethyl-N-propyl-N-pentylammonium cation, N-dimethyl-N-propyl-N-hexylammonium cation, N-dimethyl-N-propyl-N-heptylammonium cation, N-dimethyl-N-butyl-N-hexylammonium cation, N-dimethyl-N-hexyl ammonium cation, N, N, N-diethyl-N-butyl-N-heptylammonium cation, N-dimethyl-N-pentyl-N-hexylammonium cation, N-dimethyl-N, N-dihexylammonium cation, trimethylheptylammonium cation, N-diethyl-N-methyl-N-propylammonium cation, N-diethyl-N-methyl-N-pentylammonium cation, N-diethyl-N-methyl-N-heptylammonium cation, N-diethyl-N-propyl-N-pentylammonium cation, triethylpropylammonium cation, triethylpentylammonium cation, triethylheptylammonium cation, N-diethyl-N-butyl-N-heptylammonium cation, N-diethyl-N-propyl-N-pentylammonium cation, N-diethyl-N-, N, N-dipropyl-N-methyl-N-ethylammonium cation, N-dipropyl-N-methyl-N-pentylammonium cation, N-dipropyl-N-butyl-N-hexylammonium cation, N-dipropyl-N, N-dihexylammonium cation, N-dibutyl-N-methyl-N-pentylammonium cation, N-dibutyl-N-methyl-N-hexylammonium cation, trioctylmethylammonium cation, N-methyl-N-ethyl-N-propyl-N-pentylammonium cation.

Examples of the cation represented by the formula (E) include a sulfonium cation and the like. In addition, R in the formula (E) is_pSpecific examples thereof include methyl, ethyl, propyl, butyl, hexyl, octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl and octadecyl.

On the other hand, the anionic component is not particularly limited as long as it is an anionic component capable of forming an ionic compound which is solid at ordinary temperature (25 ℃), and examples thereof include Cl^-、Br^-、I^-、AlCl₄ ^-、Al₂Cl₇ ^-、BF₄ ^-、PF₆ ^-、ClO₄ ^-、NO₃ ^-、CH₃COO^-、CF₃COO^-、CH₃SO₃ ^-、CF₃SO₃ ^-、C₄F₉SO₃ ^-、(CF₃SO₂)₂N^-、(C₂F₅SO₂)₂N^-、(C₃F₇SO₂)₂N^-、(C₄F₉SO₂)₂N^-、(CF₃SO₂)₃C^-、AsF₆ ^-、SbF₆ ^-、NbF₆ ^-、TaF₆ ^-、F(HF)_n ^-、(CN)₂N^-、C₄F₉SO₃ ^-、(C₂F₅SO₂)₂N^-、C₃F₇COO^-、(CF₃SO₂)(CF₃CO)N^-、C₉H₁₉COO^-、(CH₃)₂PO₄ ^-、(C₂H₅)₂PO₄ ^-、C₂H₅OSO₃ ^-、C₆H₁₃OSO₃ ^-、C₈H₁₇OSO₃ ^-、CH₃(OC₂H₄)₂OSO₃ ^-、C₆H₄(CH₃)SO₃ ^-、(C₂F₅)₃PF₃ ^-、CH₃CH(OH)COO^-And (FSO)₂)₂N^-And the like.

Further, as the anion component, an anion represented by the following formula (F) or the like may be used.

[ CHEM 2 ]

Specific examples of the ionic compound used in the present invention can be suitably selected from the combinations of the above-mentioned cationic component and anionic component, and include, for example, 1-butylpyridinium bromide, 1-butylpyridinium chloride, 1-butylpyridinium hexafluorophosphate, 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, and mixtures thereof, 1-hexylpyridinium hexafluorophosphate, 1-octylpyridinium hexafluorophosphate, 1-nonylpyridinium hexafluorophosphate, 2-methyl-1-dodecylpyridinium hexafluorophosphate, 4-methyl-1-octylpyridinium hexafluorophosphate, 1-octylpyridinium dodecylbenzene sulfonate, 1-dodecylpyridinium thiocyanate, 1-dodecylpyridinium dodecylbenzene 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, and mixtures thereof, 1-allyl-3-methylimidazolinium chloride, 1-benzyl-3-methylimidazolinium hexafluorophosphate, 1-benzyl-3-methylimidazolinium tetrafluoroborate, 1-butyl-2, 3-dimethylimidazolinium bromide, 1-butyl-2, 3-dimethylimidazolinium chloride, 1-butyl-2, 3-dimethylimidazolinium hexafluorophosphate, 1-butyl-2, 3-dimethylimidazolinium trifluoromethanesulfonate, 1-butyl-3-methylimidazolinium bromide, 1-butyl-3-methylimidazolinium chloride, methyl imidazolinium chloride, methyl, 1-ethyl-2, 3-dimethylimidazolinium chloride, 1-ethyl-2, 3-dimethylimidazolinium hexafluorophosphate, 1-ethyl-2, 3-dimethylimidazolinium tetrafluoroborate, 1-ethyl-3-methylimidazolinium bromide, 1-ethyl-3-methylimidazolinium chloride, 1-ethyl-3-methylimidazolinium hexafluorophosphate, 1-ethyl-3-methylimidazolinium p-toluenesulfonate, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium benzoate, tetrabutylammonium methanesulfonate, tetrabutylnonafluorobutanesulfonate, tetrabutylammonium hexafluorophosphate, tetrabutylammonium tetrafluoroborate, tetrabutylammonium trifluoromethanesulfonate, tetrabutylammonium fluorobutanesulfonate, tetrabutylammonium hexafluorophosphate, tetrabutylammonium tetrafluoroborate, tetrabutylammonium trifluoromethanesulfonate, tetrabutylammonium hexafluorophosphate, and mixtures thereof, 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, tetrapentylammonium bromide, tetrapentylammonium chloride, hexyltrimethylammonium bis (trifluoromethanesulfonyl) imide, hexyltrimethylammonium bromide, hexyltrimethylammonium chloride, tetrabutylphosphonium bromide, tetrabutylphosphonium chloride, tetrabutylphosphonium tetrafluoroborate, tetrabutylphosphonium methanesulfonate, tetrabutylhexadecylphosphonium bromide, and the like.

The ionic compound may be a commercially available compound or may be synthesized as follows. The method for synthesizing the ionic compound is not particularly limited as long as the target ionic compound can be obtained, and generally, a halide method, a hydroxide method, an acid ester method, a complexation method, a neutralization method, and the like as described in "ionic liquid-the first and future of development-" [ (strain) CMC release ] can be used.

The following synthesis methods using nitrogen-containing onium salts as examples are shown for the halide method, hydroxide method, acid ester method, complex method and neutralization method, and other ionic compounds such as sulfur-containing onium salts and phosphorus-containing onium salts can be obtained by the same methods.

The halide method is a method performed by reactions represented by the following formulas (1) to (3). First, a tertiary amine is reacted with a haloalkane to obtain a halide. An anion structure (A) having a structure of an anion of a compound having an objective ionic property and a halide obtained in the reaction formula (1) using chlorine, bromine, or iodine as a halogen^-) The acid (HA) or salt (MA, M are cations forming a salt with the target anion, such as ammonium, lithium, sodium, potassium) to obtain the target ionic compound (R₄NA)。

[ CHEM 3 ]

(1)R₃N+RX→R₄NX(X:Cl,Br,I)

(2)R₄N+HA→R₄NA+HX

(3)R₄N+MA→R₄NA+MX(M:NH₄Li, Na, K, Ag, etc.)

The hydroxide method is a method in which the reaction proceeds as shown in (4) to (8). First, a halide (R)₄NX) is electrolyzed by ion exchange membrane method (reaction formula (4)), OH-type ion exchange resin method (reaction formula (5)), or mixed with mercury oxide (Ag)₂O) (reaction formula (6)) to obtain a hydroxide (R)₄NOH). The target ionic compound (R) was obtained by reacting the obtained hydroxide (using chlorine, bromine, and iodine as halogens) using the reaction formulae (7) to (8) in the same manner as in the halogenation method described above₄NA)。

[ CHEM 4 ]

(4)R₄NX+H₂O→R₄NOH+1/2H₂+1/2X₂(X:Cl,Br,I)

(5)R₄NX+P→R₄NOH + P-X (P-OH: OH type ion exchange resin))

(6)R₄NX+1/2Ag₂O+1/2H₂O→R₄NOH+AgX

(7)R₄NOH+HA→R₄NA+H2O

(8)R₄NOH+MA→R₄NA+MOH(M:NH₄Li, Na, K, Ag, etc.)

The acid ester method is carried out by the reactions shown in (9) to (11). First, a tertiary amine (R)₃N) reacting with acid ester to obtain acid ester. The acid ester obtained in the reaction of (reaction formula (9), an ester using an inorganic acid such as sulfuric acid, sulfurous acid, phosphoric acid, phosphorous acid, or carbonic acid, an ester using an organic acid such as methanesulfonic acid, methylphosphonic acid, or formic acid, or the like, is used as an acid ester to obtain the target ionic compound (R) by the reactions of the reaction formulae (10) to (11) in the same manner as in the halogenation method described above₄NA). Further, by using a methyltrifluoromethane sulfonate, a methyltrifluoroacetate, or the like as the acid ester, an ionic compound can also be obtained as it is.

[ CHEM 5 ]

(9)R₃N+ROY→R₄NOY

(OY：

Etc.)

(10)R₄NOY+HA→R₄NA+HOY

(OY：

In the case of (a) in (b),

)

(11)R₄NOY+MA→R₄NA+MOY(M：NH₄li, Na, K, Ag, etc.)

The complexation method is a method that proceeds by the reactions shown in (12) to (15). First, the halide (R) of quaternary ammonium is reacted₄NX), quaternary ammonium hydroxides (R)₄NOH), carbonate of quaternary ammonium (R)₄NOCO₂CH₃) Etc. with Hydrogen Fluoride (HF), ammonium fluoride (NH)₄F) And reacting to obtain the fluorinated quaternary ammonium salt. The quaternary ammonium fluoride salts obtained in the reaction formulas (12) to (14) and BF are mixed₃，AlF₃，PF₅，AsF₅，SbF₅，NbF₅，TaF₅And the ionic compound can be obtained by performing a complex reaction with the fluoride.

(reaction formula (15))

[ CHEM 6 ]

(12)R₄NX+HF→R₄NF+HX(X：Cl，Br，I)

(13)R₄NY+HF→R₄NF+HY(Y：OH，OCO₂CH₃)

(14)R₄NY+NH₄F→R₄NF+NH₃+HY(Y：OH，OCO₂CH₃)

(15)R₄NF+MF_n-1→R₄NMF_n

(MF_n-1：BF₃，AlF₃，PF₅，AsF₅，SbF₅，NbF₅，TaF₅Etc.)

The neutralization method is a method in which the reaction is carried out as shown in (16). Can be prepared by reacting a tertiary amine with HBF₄，HPF₆，CH₃COOH，CF₃COOH，CF₃SO₃H，(CF₃SO₂)₂NH，(CF₃SO₂)₃CH，(C₂F₅SO₂)₂NH, etc.

[ CHEM 7 ]

(16)R₃N+HZ→R₃HN⁺Z^-

[HZ：HBF₄，HPF₆，CH₃COOH，CF₃COOH，CF₃SO₃H，(CF₃SO₂)₂NH，(CF₃SO₂)₃CH，(C₂F₅SO₂)₂Organic acids such as NH]

R in the above formulae (1) to (16) represents hydrogen or a hydrocarbon group having 1 to 20 carbon atoms, and may be a functional group in which a part of the hydrocarbon group is substituted with a hetero atom.

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 still more preferably 0.005 to 1 part by mass, based on 100 parts by mass of the (meth) acrylic polymer. Within the above range, both antistatic properties and low staining properties are easily achieved, and therefore, the range is preferable.

In the adhesive sheet of the present invention, the adhesive composition preferably 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, the compound having an oxyalkylene chain is more preferably an organopolysiloxane having an oxyalkylene chain. It is presumed that by using the organopolysiloxane, the surface free energy of the adhesive surface is reduced and the peeling is made light at the time of high-speed peeling.

As the organopolysiloxane, a known organopolysiloxane having a polyoxyalkylene chain main chain can be suitably used, and those represented by the following formulae are preferred.

(in the formula, R₁And/or R₂The alkylene oxide chain has 1-6 carbon atoms, the alkylene in the alkylene oxide chain can be a straight chain or a branched chain, and the end of the alkylene oxide chain can be an alkoxy or a hydroxyl. In addition, R₁Or R₂Either one of them may be a hydroxyl group, or may be an alkyl group or an alkoxy group, or may be a functional group in which a part of the alkyl group or the alkoxy group is substituted with a hetero atom. n is an integer of 1 to 300. )

The organopolysiloxane has a siloxane-containing site (siloxane site) as a main chain, and an oxyalkylene chain is bonded to a terminal of the main chain. By using the organosiloxane having the oxyalkylene chain, it is presumed that the compatibility between the (meth) acrylic polymer and the ionic compound is balanced and light peeling can be achieved.

In addition, asThe organopolysiloxane of the present invention can be constituted, for example, as follows. Specifically, R in the formula₁And/or R₂The alkylene oxide chain contains a hydrocarbon having 1 to 6 carbon atoms, and examples of the alkylene oxide chain include an oxymethylene group, an oxyethylene group, an oxypropylene group, and an oxybutylene group, and among them, an oxyethylene group and an oxypropylene group are preferable. In addition, R₁And R₂When they all have an oxyalkylene chain, they may be the same or different.

[ CHEM 9 ]

The oxyalkylene-chain hydrocarbon may be a straight chain or a branched chain.

Further, the terminal of the oxyalkylene chain may be an alkoxy group or a hydroxyl group, and among them, an alkoxy group is more preferable. When a separator is bonded to the surface of the adhesive layer for the purpose of protecting the adhesive surface, if the separator is an organopolysiloxane having a hydroxyl group at the end, the organopolysiloxane interacts with the separator, and the peeling force when the separator is peeled from the surface of the adhesive layer may increase.

In addition, n is an integer of 1 to 300, preferably 10 to 200, and more preferably 20 to 150. If n is within the above range, a balance of compatibility with the base polymer can be achieved, which is a preferable mode. Further, the molecule may have a reactive substituent such as a (meth) acryloyl group, allyl group, or hydroxyl group. The organopolysiloxane can be used alone, or 2 or more kinds can be used in combination.

Specific examples of the organopolysiloxane having an oxyalkylene chain include those commercially available under the trade names X-22-4952, X-22-4272, X-22-6266, KF-6004, KF-889 (manufactured BY shin-Etsu chemical industries, Ltd.), BY16-201, SF8427 (manufactured BY Toyo Corning Co., Ltd.), IM22 (manufactured BY Asahi Kawakko Co., Ltd.), and the like. These compounds may be used alone, or 2 or more of them may be used in combination. .

In addition, in addition to the organosiloxane having (bound to) an oxyalkylene chain in the main chain, an organosiloxane having (bound to) an oxyalkylene chain in a side chain may be used, and the use of the organosiloxane having an oxyalkylene chain in a side chain is more preferable than the use of the organosiloxane having an oxyalkylene chain in the main chain. As the organopolysiloxane, those having a known polyoxyalkylene side chain can be suitably used, and those represented by the following formula are preferred.

[ CHEM 10 ]

(in the formula, R₁Is a 1-valent organic radical, R₂，R₃And R₄Is alkylene, R₅Is hydrogen or an organic group, and m and n are integers of 0 to 1000. However, m and n are not 0 at the same time. a and b are integers of 0 to 100. However, a and b are not 0 at the same time. )

The organopolysiloxane of the present invention may have the following structure, for example. Specifically, R in the formula₁The organic group having a valence of 1 as exemplified for an alkyl group such as a methyl group, an ethyl group or a propyl group, an aryl group such as a phenyl group or a tolyl group, or an aralkyl group such as a benzyl group or a phenethyl group may have a substituent such as a hydroxyl group. R₂、R₃And R₄An alkylene group having 1 to 8 carbon atoms such as a methylene group, an ethylene group, and a propylene group can be used. Here, R₃And R₄Is a different alkylene radical, R₂Can be reacted with R₃Or R₄The same or different. In order to increase the concentration of the ionic compound soluble in the polyoxyalkylene side chain thereof, R₃And R₄Either one of them is preferably an ethylene group or a propylene group. R₅The organic group may be an alkyl group such as methyl, ethyl or propyl, or a 1-valent organic group exemplified as an acyl group such as acetyl or propionyl, and each may have a substituent such as a hydroxyl group. These compounds may be used alone, or 2 or more of them may be used in combination. The molecule may have a reactive substituent such as a (meth) acryloyl group, allyl group, or hydroxyl group. Among the above-mentioned organosiloxanes having a polyoxyalkylene side chain, it is presumed that an organosiloxane having a polyoxyalkylene side chain having a hydroxyl end is easily producedA balance of compatibility is achieved and is therefore preferred.

[ CHEM 11 ]

Specific examples of the organopolysiloxane include those commercially available under the trade names KF-351A, KF-352A, KF-353, KF-354L, KF-355A, KF-615A, KF-945, KF-640, KF-642, KF-643, KF-6022, X-22-6191, X-22-4515, KF-6011, KF-6012, KF-6015, KF-6017, X-22-2516 (manufactured by shin-Etsu chemical industries, 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 (manufactured by Doudouning Corne, Ltd.), TSF-4440, TSF-4441, TSF-4445, TSF-4450, TSF-4446, TSF-4452, TSF-4460 (manufactured by Michigan high and New materials Co., Ltd.), BYK-333, BYK-307, BYK-377, BYK-UV3500 and BYK-UV3570 (manufactured by Bikk Nippon Co., Ltd.). These may be used alone, or 2 or more of them may be used in combination.

The organopolysiloxane used in the present invention preferably has an HLB (hydrophilic-lipophilic balance) value of 1 to 16, more preferably 3 to 14. If the HLB value is outside the above range, the staining property to an adherend is deteriorated, which is not suitable.

The content of the organopolysiloxane is preferably 0.01 to 5 parts by mass, more preferably 0.03 to 3 parts by mass, and still more preferably 0.05 to 1 part by mass, per 100 parts by mass of the (meth) acrylic polymer. Within the above range, the ionic compound having an organic cation which is solid at room temperature (25 ℃) and the organopolysiloxane are stable even at high temperatures, can interact with each other, improve conductivity, suppress the peeling electrification voltage after storage at high temperatures over time to a low level, and further satisfy light peeling properties (removability).

In the surface protective film of the present invention, the adhesive composition preferably contains a crosslinking agent. In the present invention, the adhesive composition is used to prepare an adhesive layer. For example, when the adhesive contains the (meth) acrylic polymer, a pressure-sensitive adhesive sheet (adhesive layer) having more excellent heat resistance can be obtained by appropriately adjusting the constituent unit and the constituent ratio of the (meth) acrylic polymer, the selection and addition ratio of the crosslinking agent, and the like, and crosslinking the (meth) acrylic polymer.

As the crosslinking agent used in the present invention, an isocyanate compound, an epoxy compound, a melamine resin, an aziridine derivative, a metal chelate compound, and the like can be used. These compounds may be used alone, or 2 or more of them may be used in combination.

Examples of the isocyanate compound (isocyanate-based crosslinking agent) include aliphatic polyisocyanates such as trimethylene diisocyanate, tetramethylene diisocyanate, Hexamethylene Diisocyanate (HDI) and dimer acid diisocyanate, alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate and isophorone diisocyanate (IPDI), aromatic isocyanates such as 2, 4-tolylene diisocyanate, 4' -diphenylmethane diisocyanate and Xylylene Diisocyanate (XDI), the isocyanate compound (isocyanate crosslinking agent) is modified with an allophanate bond, biuret bond, isocyanurate bond, uretdione bond, urea bond, carbodiimide bond, uretonimine bond, oxadiazinetrione bond or the like. Examples of commercially available products include TAKENATE 300S, TAKENATE500, TAKENATE D165N, TAKENATE D178N (manufactured by Takara pharmaceutical industries, Ltd.), SUMIDUR T80, SUMIDUR L, DESMODUR N3400 (manufactured by Suzuki Bayer polyurethane Co., Ltd.), MILLIONATE MR, MILLIONATE MT, COLONATE L, COLONATE HL, and COLONATE HX (manufactured by Nippon polyurethane industries, Ltd.). These isocyanate compounds may be used alone, or 2 or more kinds may be used in combination, or a 2-functional isocyanate compound and a 3-functional isocyanate compound may be used in combination. By using the crosslinking agent in combination, the adhesion and the rebound resistance (adhesion to a curved surface) can be achieved at the same time, and a surface protective film having more excellent adhesion reliability can be obtained.

Examples of the epoxy compound include N, N, N ', N' -tetraglycidyl-m-xylyldiamine (trade name TETRAD-X, manufactured by Mitsubishi gas chemical corporation), 1, 3-bis (N, N-diglycidylaminomethyl) cyclohexane (trade name TETRAD-C, manufactured by Mitsubishi gas chemical corporation), and the like.

Examples of the melamine resin include hexamethylolmelamine. Examples of the aziridine derivative include trade names HDU, TAZM and TAZO (manufactured by CRP Co., Ltd.) which are commercially available.

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

The content of the crosslinking agent used in the present invention is, for example, preferably 0.01 to 10 parts by mass, more preferably 0.1 to 8 parts by mass, further preferably 0.5 to 5 parts by mass, and most preferably 1.0 to 2.5 parts by mass based on 100 parts by mass of the (meth) acrylic polymer. When the content is less than 0.01 part by mass, crosslinking formation by the crosslinking agent becomes insufficient, the cohesive force of the obtained adhesive agent layer becomes small, and sufficient heat resistance may not be obtained, and the content 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 wetting with an adherend (for example, a polarizing plate) becomes insufficient, and there is a tendency that the foaming is caused between the adherend and the adhesive layer (adhesive composition layer). Further, when the amount of the crosslinking agent is large, the peeling electrification characteristics tend to be lowered. These crosslinking agents may be used alone, or 2 or more kinds thereof may be used in combination.

The adhesive composition may further contain a crosslinking catalyst in order to more effectively promote any of the above crosslinking reactions. Examples of the crosslinking catalyst include tin catalysts such as dibutyltin dilaurate and dioctyltin dilaurate, iron tris (acetylacetonate), iron tris (hexane-2, 4-dione), iron tris (heptane-3, 5-dione), iron tris (5-methylhexane-2, 4-dione), iron tris (octane-2, 4-dione), iron tris (6-methylheptane-2, 4-dione), iron tris (2, 6-dimethylheptane-3, 5-dione), iron tris (nonane-2, 4-dione), iron tris (nonane-4, 6-dione), iron tris (2,2,6, 6-tetramethylheptane-3, 5-dione), iron tris (nonane-2, 4-dione), iron (tetrazinone), and iron, Tri (tridecane-6, 8-dione) iron, tri (1-phenylbutane-1, 3-dione) iron, tri (hexafluoroacetylacetonato) iron, tri (ethyl acetoacetate) iron, tri (n-propyl acetoacetate) iron, tri (isopropyl acetoacetate) iron, tri (n-butyl acetoacetate) iron, tri (sec-butyl acetoacetate) iron, tri (tert-butyl acetoacetate) iron, tri (methyl propionylacetate) iron, tri (ethyl propionylacetate) iron, tri (n-propyl propionylacetate) iron, tri (isopropyl propionylacetate) iron, tri (n-butyl propionylacetate) iron, tri (sec-butyl propionylacetate) iron, tri (tert-butyl propionylacetate) iron, tri (benzyl acetoacetate) iron, tri (dimethyl malonate) iron, tri (diethyl malonate) iron, trimethoxyiron, triethoxy iron, triisopropoxyberric, tri (propyloxy) iron, tri (tert-butyl acetoacetate), tri (tert-butyl acrylate) iron, tri (benzyl acetoacetate), tri (dimethyl malonate) iron, tri (diethyl malonate) iron, trimethoxy iron, triethoxy iron, Iron-based catalysts such as ferric chloride. These crosslinking catalysts may be used in 1 kind, or 2 or more kinds may be used in combination.

The content (amount used) of the crosslinking catalyst is not particularly limited, and is, for example, approximately preferably 0.0001 to 1 part by mass, and more preferably 0.001 to 0.5 part by mass, based on 100 parts by mass of the (meth) acrylic polymer. When the content is within the above range, the crosslinking reaction speed is high in forming the adhesive layer, and the shelf life of the adhesive composition is also prolonged, which is a preferable embodiment.

The adhesive composition of the present invention may contain a polyoxyalkylene chain-containing compound (including a compound having a polyoxyalkylene chain) which does not contain an organopolysiloxane. When the adhesive composition contains the above compound, an adhesive composition having more excellent wettability to an adherend can be obtained.

Specific examples of the polyoxyalkylene chain-containing compound not containing an organopolysiloxane include nonionic surfactants such as polyoxyalkylene alkylamines, polyoxyalkylene diamines, polyoxyalkylene fatty acid esters, polyoxyalkylene sorbitan fatty acid esters, polyoxyalkylene alkylphenyl ethers, polyoxyalkylene alkyl ethers, polyoxyalkylene alkylallyl ethers, and polyoxyalkylene alkylphenyl allyl ethers; anionic surfactants such as polyoxyalkylene alkyl ether sulfate, polyoxyalkylene alkyl ether phosphate, polyoxyalkylene alkyl phenyl ether sulfate and polyoxyalkylene alkyl phenyl ether phosphate; and, a cationic surfactant having a polyoxyalkylene chain (polyalkylene oxide chain), a zwitterionic surfactant, a polyether compound having a polyoxyalkylene chain (including derivatives thereof), a polyester compound having a polyoxyalkylene chain (including derivatives thereof), an acrylic compound having a polyoxyalkylene chain (including derivatives thereof), and the like. Further, a polyoxyalkylene chain-containing monomer may be blended as the polyoxyalkylene chain-containing compound with the acrylic polymer. The polyoxyalkylene chain-containing compound may be used alone or in combination of 2 or more.

Specific examples of the polyether compound having a polyoxyalkylene chain include polypropylene glycol (PPG) -polyethylene glycol (PEG) block copolymers, PPG-PEG-PPG block copolymers, PEG-PPG-PEG block copolymers, and the like. Examples of the derivative of the polyether compound having a polyoxyalkylene chain include an oxypropylene group-containing compound whose terminal is etherified (such as PPG monoalkyl ether and PEG-PPG monoalkyl ether), an oxypropylene group-containing compound whose terminal is acetylated (such as end-acetylated PPG), and the like.

Specific examples of the acrylic compound having a polyoxyalkylene chain include (meth) acrylate polymers having an oxyalkylene group. The oxyalkylene group is preferably an oxyalkylene unit having an addition mole number of 1 to 50, more preferably 2 to 30, and further preferably 2 to 20, from the viewpoint of coordination of an ionic compound. The terminal of the oxyalkylene group may be an original hydroxyl group, or may be substituted with an alkyl group, a phenyl group or the like.

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

Further, as the monomer unit (component), another monomer unit (component) other than the above-mentioned alkylene oxide (meth) acrylate may be used. Specific examples of the other monomer unit include acrylic esters and/or methacrylic esters having an alkyl group having 1 to 14 carbon atoms such as methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, isobutyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-dodecyl (meth) acrylate, n-tridecyl (meth) acrylate, and n-tetradecyl (meth) acrylate.

Further, as other monomer units (components) other than the alkylene oxide (meth) acrylate, a carboxyl group-containing (meth) acrylate, a phosphoric group-containing (meth) acrylate, a cyano group-containing (meth) acrylate, a vinyl ester, an aromatic vinyl compound, an acid anhydride group-containing (meth) acrylate, a hydroxyl group-containing (meth) acrylate, an amide group-containing (meth) acrylate, an amino group-containing (meth) acrylate, an epoxy group-containing (meth) acrylate, N-acryloyl morpholine, a vinyl ether, and the like can be suitably used.

In a preferred embodiment, the polyoxyalkylene chain-containing compound not containing organopolysiloxane is a compound having a (poly) oxyethylene chain in at least a part thereof. By blending the (poly) oxyethylene chain compound, the compatibility of the base polymer with the antistatic component is improved, leakage to an adherend is suppressed well, and an adhesive composition with low staining can be obtained. Among these, when a PPG-PEG-PPG block copolymer is used, an adhesive composition having excellent low-staining properties can be obtained. The polyoxyethylene chain-containing compound preferably has a mass of the (poly) oxyethylene chain in the total compound of 5 to 90 mass%, more preferably 5 to 85 mass%, even more preferably 5 to 80 mass%, and most preferably 5 to 75 mass%.

The molecular weight of the polyoxyalkylene chain-containing compound not containing organopolysiloxane is preferably 50000 or less number average molecular weight (Mn), more preferably 200 to 30000, still more preferably 200 to 10000, and particularly preferably 200 to 5000. If Mn is too large as compared with 50000, compatibility with the acrylic polymer is lowered, and the adhesive agent layer tends to be whitened. If Mn is too small as compared with 200, contamination by the polyoxyalkylene compound may be easily generated. Here, Mn means a polystyrene equivalent value obtained by GPC (gel permeation chromatography).

Specific examples of commercially available products of the polyoxyalkylene chain-containing compound not containing an organopolysiloxane include Adeka Pluronic 17R-4, Adeka Pluronic 25R-2 (both manufactured by ADEKA Co., Ltd.), EMULGEN120 (manufactured by Kao corporation), and the like.

The amount of the polyoxyalkylene chain-containing compound not containing an organopolysiloxane may be, for example, 0.005 to 20 parts by mass, preferably 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, based on 100 parts by mass of the (meth) acrylic polymer. If the amount is too small, the effect of preventing leakage of the antistatic component is reduced, and if it is too large, contamination by the polyoxyalkylene compound may be easily generated.

Further, the adhesive composition may contain an acrylic oligomer. The weight average molecular weight of the acrylic oligomer is preferably 1000 or more and less than 30000, more preferably 1500 or more and less than 20000, and further preferably 2000 or more and less than 10000. The acrylic oligomer is a (meth) acrylic polymer containing, as a monomer unit, a (meth) acrylic monomer having an alicyclic structure represented by the following general formula (1), and when used in the acrylic pressure-sensitive adhesive composition for repeeling of the present embodiment, functions as a tackifier resin, improves the adhesiveness (adhesiveness), and has an effect of suppressing swelling of the pressure-sensitive adhesive sheet.

CH₂＝C(R¹)COOR²(1)

[ in the formula (1), R¹Is a hydrogen atom or a methyl group, R²Is an alicyclic hydrocarbon having an alicyclic structure]

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

In the present embodiment, the alicyclic hydrocarbon constituting the acrylic oligomer preferably has a bridged ring structure. The bridged ring structure is an alicyclic structure having three or more rings. By providing the acrylic oligomer with a bulky structure such as a bridged ring structure, the tackiness (adhesiveness) of the pressure-sensitive adhesive composition for repeeling (pressure-sensitive adhesive sheet for repeeling) can be further improved.

R as the alicyclic hydrocarbon having a bridged ring structure²Examples thereof include a dicyclopentyl group represented by the following formula (3a), a dicyclopentenyl group represented by the following formula (3b), an adamantyl group represented by the following formula (3c), a tricyclopentyl group represented by the following formula (3d), and a tricyclopentenyl group represented by the following formula (3 e).In addition, when UV polymerization is used in synthesizing an acrylic oligomer or in producing an adhesive composition, from the viewpoint of preventing polymerization inhibition, among (meth) acrylic monomers having an alicyclic structure of at least three rings having a bridged ring structure, a (meth) acrylic monomer having a saturated structure such as a dicyclopentyl group represented by the following formula (3a), an adamantyl group represented by the following formula (3c), or a tricyclopentyl group represented by the following formula (3d) can be particularly preferably used as a monomer constituting the acrylic oligomer.

[ CHEM 12 ]

Examples of the (meth) acrylic monomer having a tricyclic or higher alicyclic structure having a bridged ring structure include (meth) acrylic esters such as dicyclopentyl methacrylate, dicyclopentyl acrylate, dicyclopentyloxyethyl methacrylate, dicyclopentyloxyethyl acrylate, tricyclopentyl methacrylate, tricyclopentyl acrylate, 1-adamantyl methacrylate, 1-adamantyl acrylate, 2-methyl-2-adamantyl methacrylate, 2-methyl-2-adamantyl acrylate, 2-ethyl-2-adamantyl methacrylate, and 2-ethyl-2-adamantyl acrylate. Such (meth) acrylic monomers may be used alone or in combination of 2 or more.

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

Examples of the (meth) acrylic ester monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, hexyl (meth) acrylate, alkyl (meth) acrylates such as 2-ethylhexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, and dodecyl (meth) acrylate; aryl (meth) acrylates such as phenyl (meth) acrylate and benzyl (meth) acrylate; (meth) acrylic acid esters obtained from terpene compound derivative alcohols, and the like. Such (meth) acrylate monomers may be used alone, or 2 or more kinds may be used in combination.

The acrylic oligomer may be obtained by copolymerizing a monomer component (copolymerizable monomer) other than the (meth) acrylic monomer component unit, the monomer component being copolymerizable with the (meth) acrylic monomer.

Examples of the other monomer copolymerizable with the (meth) acrylate include carboxyl group-containing monomers such as acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid;

alkoxyalkyl (meth) acrylate monomers such as methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, propoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, and ethoxypropyl (meth) acrylate;

salts such as alkali metal (meth) acrylate;

(poly) alkylene glycol di (meth) acrylate monomers such as ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, and tripropylene glycol di (meth) acrylate;

a polyvalent (meth) acrylate monomer such as trimethylolpropane tri (meth) acrylate;

vinyl esters such as vinyl acetate and vinyl propionate;

halogenated vinyl compounds such as vinylidene chloride and 2-chloroethyl (meth) acrylate;

oxazoline group-containing polymerizable compounds such as 2-vinyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline and 2-isopropenyl-2-oxazoline;

polymerizable compounds containing an aziridinyl group such as (meth) acryloylaziridine and 2-aziridinylethyl (meth) acrylate;

epoxy group-containing vinyl monomers such as allyl glycidyl ether, glycidyl ether (meth) acrylate, and 2-ethyl glycidyl ether (meth) acrylate;

hydroxyl group-containing vinyl monomers such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and adducts of lactones and 2-hydroxyethyl (meth) acrylate;

macromonomers in which an unsaturated group such as a (meth) acryloyl group, a styryl group, or a vinyl group is bonded to the terminal of polyalkylene glycol such as polypropylene glycol, polyethylene glycol, polytetramethylene glycol, polybutylene glycol, a copolymer of polyethylene glycol and polypropylene glycol, and a copolymer of polybutylene glycol and polyethylene glycol;

fluorine-containing vinyl monomers such as fluorine-substituted alkyl (meth) acrylates;

acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride;

aromatic vinyl compound monomers such as styrene, α -methylstyrene and vinyltoluene;

reactive halogen-containing vinyl monomers such as 2-chloroethyl vinyl ether and monochloroacetic acid vinyl ester;

amide group-containing vinyl monomers such as (meth) acrylamide, N-isopropyl (meth) acrylamide, N-butyl (meth) acrylamide, N-diethyl (meth) acrylamide, N-dimethyl (meth) acrylamide, N-methylol (meth) acrylamide, N-hydroxyethyl (meth) acrylamide, N-methylolpropane (meth) acrylamide, N-methoxyethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, and N-acryloylmorpholine;

succinimide monomers such as N- (meth) acryloyloxymethylene succinimide, N- (meth) acryloyl-6-oxohexamethylene succinimide, and N- (meth) acryloyl-8-oxohexamethylene succinimide;

maleimide monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide and N-phenylmaleimide;

itaconimide-based monomers such as N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexyl itaconimide, N-cyclohexylitaconimide and N-lauryl itaconimide;

nitrogen-containing condensed ring system monomers such as N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N-vinylpyrrole, N-vinylimidazole, N-vinyloxazole, N- (meth) acryloyl-2-pyrrolidone, N- (meth) acryloylpiperidine, N- (meth) acryloylpyrrolidine, N-vinylmorpholine, N-vinylpyrazole, N-vinylisoxazole, N-vinylthiazole, N-vinylisothiazole and N-vinylpyridazine;

n-vinylcarboxylic acid amides;

lactam monomers such as N-vinylcaprolactam;

cyanoacrylate monomers such as (meth) acrylonitrile;

aminoalkyl (meth) acrylate monomers such as aminoethyl (meth) acrylate, N-dimethylaminoethyl (meth) acrylate, and t-butylaminoethyl (meth) acrylate;

imide group-containing monomers such as cyclohexylmaleimide and isopropylmaleimide;

isocyanurate group-containing monomers such as 2-isocyanuric ethyl (meth) acrylate;

silicone-containing vinyl monomers such as vinyltrimethoxysilane, gamma-methacryloxypropyltrimethoxysilane, allyltrimethoxysilane, trimethoxysilylpropylallylamine, and 2-methoxyethoxy-trimethoxysilane;

hydroxyl group-containing monomers such as hydroxyalkyl (meth) acrylates including hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxyhexyl (meth) acrylate, hydroxyoctyl (meth) acrylate, hydroxydecyl (meth) acrylate, hydroxylauryl (meth) acrylate, and methyl (4-hydroxymethylcyclohexyl) methacrylate;

acrylate monomers having a condensed ring, a halogen atom, a silicon atom, and the like, such as tetrahydrofurfuryl (meth) acrylate, fluorine atom-containing (meth) acrylate, and silicone (meth) acrylate;

olefin monomers such as isoprene, butadiene, and isobutylene;

vinyl ether monomers such as methyl vinyl ether and ethyl vinyl ether;

olefins or dienes such as ethylene, butadiene, isoprene, and isobutylene;

vinyl ethers such as vinyl alkyl ether;

vinyl chloride;

and macromonomers having a radical polymerizable vinyl group at the terminal of the monomer after ethylene polymerization. These monomers may be copolymerized with the (meth) acrylate ester, either 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), a copolymer of Methyl Methacrylate (MMA) and isobornyl methacrylate (IBXMA), a copolymer of cyclohexyl methacrylate (CHMA) and Acryloylmorpholine (ACMO), a copolymer of cyclohexyl methacrylate (CHMA) and Diethylacrylamide (DEAA), a copolymer of 1-adamantyl acrylate (ADA) and Methyl Methacrylate (MMA), a copolymer of dicyclopentanyl methacrylate (DCPMA) and isobornyl methacrylate (IBXMA), a copolymer of dicyclopentanyl methacrylate (DCPMA) and Methyl Methacrylate (MMA), a copolymer of dicyclopentanyl methacrylate (DCPMA) and N-vinyl-2-pyrrolidone (NVP), a copolymer of dicyclopentanyl methacrylate (CHMA) and N-vinyl-2-pyrrolidone (NVP), a copolymer of cyclohexyl methacrylate (CHMA) and isobornyl methacrylate (IBXMA), and a copolymer of methyl methacrylate (DCPMA), Homopolymers of dicyclopentyl methacrylate (DCPMA) and hydroxyethyl methacrylate (HEMA), copolymers of dicyclopentyl methacrylate (DCPMA) and Acrylic Acid (AA), dicyclopentyl methacrylate (DCPMA), cyclohexyl methacrylate (CHMA), isobornyl methacrylate (IBXMA), isobornyl acrylate (IBXA), dicyclopentyl acrylate (DCPA), 1-adamantyl methacrylate (ADMA), 1-adamantyl acrylate (ADA), Methyl Methacrylate (MMA), and the like.

Further, the acrylic oligomer may be introduced with a functional group having reactivity 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 may be used in the production of an acrylic oligomer.

When the acrylic oligomer is a copolymer of the (meth) acrylic monomer having an alicyclic structure and another (meth) acrylate monomer or copolymerizable monomer, the content of the (meth) acrylic monomer having an alicyclic structure is 5% by mass or more, preferably 10% by mass or more, more preferably 20% by mass or more, and still more preferably 30% by mass or more (usually less than 100% by mass, preferably 90% by mass or less) of the total monomers constituting the acrylic oligomer. When the (meth) acrylic monomer having an alicyclic structure is contained in an amount of 5% by mass or more, the adhesiveness (bonding) can be improved without lowering the transparency.

The weight average molecular weight of the acrylic oligomer is 1000 or more and less than 30000, preferably 1500 or more and less than 20000, and more preferably 2000 or more and less than 10000. If the weight average molecular weight is 30000 or more, tackiness (adhesiveness) is lowered. In addition, if the weight average molecular weight is less than 1000, it becomes a low molecular weight, thus causing a decrease in the adhesive force of the adhesive sheet.

Further, the adhesive composition may contain a compound that causes keto-enol tautomerism as a crosslinking retarder. For example, in an adhesive composition containing a crosslinking agent or an adhesive composition capable of being used in combination with a crosslinking agent, a mode including the compound which causes keto-enol tautomerism can be preferably employed. This can suppress excessive increase in viscosity or gelation of the adhesive composition after blending of the crosslinking agent, and can achieve the effect of extending the shelf life of the adhesive composition. It is particularly interesting to include compounds which cause keto-enol tautomerism, at least when isocyanate compounds are used as the cross-linking agent. This technique can be preferably applied, for example, to the case where the adhesive composition is in the form of an organic solvent solution or solvent-free.

As the compounds generating ketone-enol tautomerism, various β -dicarbonyl compounds can be used, specific examples include β -diketones such as acetylacetone, 2, 4-hexanedione, 3, 5-heptanedione, 2-methylhexane-3, 5-dione, 6-methylheptane-2, 4-dione, 2, 6-dimethylheptane-3, 5-dione, etc., acetoacetic acid esters such as methyl acetoacetate, ethyl acetoacetate, isopropyl acetoacetate, and tert-butyl acetoacetate, propionylacetic acid esters such as ethyl propionylacetate, isopropyl propionylacetate, and tert-butyl propionylacetate, isobutyrylacetic acid esters such as ethyl isobutyrylacetate, isopropyl isobutyrylacetate, and tert-butyl isobutyrylacetate, malonic acid esters such as methyl malonate, ethyl malonate, etc., and preferred compounds among them, acetylacetone and acetoacetic acid esters can be used alone, or 2 or more kinds of these can be used in combination.

The content of the compound which causes keto-enol tautomerism may be, for example, 0.1 to 20 parts by mass, and usually 0.5 to 15 parts by mass (for example, 1 to 10 parts by mass) is suitable for 100 parts by mass of the (meth) acrylic polymer. If the amount of the compound is too small, it may be difficult to exhibit sufficient use effects. On the other hand, if the compound is used in an amount larger than necessary, the compound may remain in the adhesive agent layer to reduce the cohesive force.

The pressure-sensitive adhesive composition used in the pressure-sensitive adhesive sheet of the present invention may further contain other known additives, and for example, powders such as coloring agents and pigments, surfactants, plasticizers, tackifiers, low molecular weight polymers, surface lubricants, leveling agents, antioxidants, anticorrosive agents, light stabilizers, ultraviolet absorbers, polymerization inhibitors, silane coupling agents, inorganic or organic fillers, metal powders, particles, foils, and the like may be appropriately added depending on the application.

The adhesive sheet of the present invention is characterized in that the adhesive sheet has an adhesive layer formed from the adhesive composition (formed by crosslinking the adhesive composition) on one side or both sides of the support film, and the crosslinking of the adhesive composition is generally performed after the application of the adhesive composition, but the adhesive layer formed from the crosslinked adhesive composition may be transferred to the support film or the like. The method for forming the adhesive layer on the support film is not particularly limited, and the adhesive layer can be produced, for example, as follows: the adhesive composition is applied to a support film, and the polymerization solvent and the like are dried and removed to form an adhesive layer on the support film. Thereafter, curing may be performed for the purpose of adjusting the migration of components in the adhesive layer, adjusting the crosslinking reaction, and the like. In the case of producing an adhesive sheet by applying the adhesive composition to a support film, one or more solvents other than the polymerization solvent may be added to the adhesive composition again in order to uniformly coat the adhesive composition on the support film.

In addition, as a method for forming the adhesive layer in the production of the adhesive sheet of the present invention, a known method used in the production of adhesive sheets can be used. Specific examples thereof include roll coating, gravure coating, reverse coating, roll brushing, spray coating, air knife coating, and extrusion coating using a die coater.

The adhesive sheet of the present invention is generally produced such that the thickness of the adhesive layer is preferably 3 to 100 μm, more preferably about 5 to 50 μm. When the thickness of the adhesive layer is within the above range, a proper balance between removability and adhesiveness (adhesiveness) can be easily obtained, and therefore, the thickness is preferable.

< baffle plate >

In the adhesive sheet (surface protective film) of the present invention, a separator may be bonded to the surface of the adhesive layer as necessary for the purpose of protecting the adhesive surface.

As a material constituting the separator, there are paper and a plastic film, but a plastic film is preferably used in view of excellent surface smoothness. The film is not particularly limited as long as it can protect the adhesive layer, and examples thereof include a polyethylene film, a polypropylene film, a polybutylene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, a vinyl chloride copolymer 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 5 to 200 μm, preferably about 10 to 100 μm. When the content is within the above range, workability of bonding to the adhesive agent layer and workability of peeling from the adhesive agent layer are excellent, and therefore, the content is preferable. The separator may be subjected to release and anti-fouling treatment using a silicone-based, fluorine-based, long-chain alkyl-based or fatty acid amide-based release agent, silica powder or the like, or antistatic treatment such as coating type, doping type, vapor deposition type or the like, as necessary.

In the adhesive sheet of the present invention (including the case of using the adhesive sheet for a surface protective film), the peel charge voltage at a peel speed of 30 m/min after the adhesive surface of the adhesive layer used for the adhesive sheet is attached to the TAC surface (surface of the polarizing plate) at 70 ℃ for 1 week (after storage at high temperature over time) is less than 0.5kV (absolute value), preferably 0.4kV or less, and more preferably 0.3kV or less. If the peeling electrification voltage is 0.5kV or more, for example, damage to a liquid crystal driver or the like may be caused, which is not preferable.

< anti-static layer (topcoat) >)

The pressure-sensitive adhesive sheet of the present invention preferably has an antistatic layer on one surface of the support film on the side opposite to the pressure-sensitive adhesive layer, the antistatic layer being formed from an antistatic agent composition containing polyaminobenzene sulfonic acid as a conductive polymer component, a polyester resin as a binder, and an isocyanate-based crosslinking agent as a crosslinking agent. The pressure-sensitive adhesive sheet preferably has an antistatic layer (topcoat layer) to improve antistatic properties of the pressure-sensitive adhesive sheet. In particular, an ionic compound having an organic cation which is solid at room temperature (25 ℃) and the organopolysiloxane are stable and interact with each other even at high temperatures, and the peeling electrification voltage after storage at high temperatures over time can be suppressed to be low. Further, the antistatic layer can stabilize the surface resistance value of the antistatic layer with time, and the antistatic layer is useful in that the antistatic layer can be bonded to an adherend as a whole of the pressure-sensitive adhesive sheet, and can provide stability in peeling electrification even when the pressure-sensitive adhesive sheet is peeled off after storage at a high temperature with time.

< conductive Polymer >

The antistatic layer preferably contains polyaminobenzene sulfonic acid as a conductive polymer component. By using the conductive polymer, antistatic properties based on an antistatic layer can be satisfied. The polyaminobenzene sulfonic acid is "water-soluble", and can be immobilized in the antistatic layer by using an isocyanate-based crosslinking agent described later, thereby improving water resistance. By using an aqueous solution containing the water-soluble conductive polymer, an antistatic layer having excellent surface resistance value with time can be obtained, which is a preferable embodiment. On the other hand, when the conductive polymer used for forming the antistatic layer is "water-dispersible", if the antistatic layer is formed using a solution containing the water-dispersible conductive polymer, aggregates are likely to be generated, and the coating cannot be performed uniformly, and the surface resistance value tends to be remarkably deteriorated with time, which is not preferable.

The amount of the conductive polymer used is preferably 10 to 200 parts by mass, more preferably 25 to 150 parts by mass, and still more preferably 40 to 120 parts by mass, based on 100 parts by mass of the binder contained in the antistatic layer (top coat layer). If the amount of the conductive polymer used is too small, the antistatic effect may be reduced, and if the amount of the conductive polymer used is too large, the adhesion of the antistatic layer to the support film may be reduced, or the transparency may be reduced, which is not preferable.

The weight average molecular weight (Mw) of the polyaminobenzene sulfonic acid used as the conductive polymer component in terms of polystyrene is preferably 5X 10⁵Hereinafter, 3 × 10 is more preferable⁵The following. In addition, the weight average molecular weight of these conductive polymers is preferably 1 in general×10³Above, more preferably 5 × 10³The above.

As a method for forming the antistatic layer, a method of applying a coating material for forming an antistatic layer (antistatic agent composition) on the first surface of the support film and drying (or curing) the coating material can be adopted, and it is preferable to contain polyaminobenzene sulfonic acid as a conductive polymer component used in the preparation of the coating material, a polyester resin as a binder, and an isocyanate-based crosslinking agent as a crosslinking agent, and it is preferable to use a form in which the essential component is dissolved in water (conductive polymer aqueous solution, or simply referred to as aqueous solution). The aqueous conductive polymer solution can be prepared, for example, by dissolving a conductive polymer having a hydrophilic functional group (which can be synthesized by a method such as copolymerization of a monomer having a hydrophilic functional group in the molecule) in water. Examples of the hydrophilic functional group include a sulfonic acid group, an amino group, an amide group, an imino group, a hydroxyl group, a mercapto group, a hydrazine group, a carboxyl group, a quaternary ammonium group, and a sulfate group (-O-SO)₃H) Phosphate groups (e.g., -O-PO (OH)₂) And the like. The hydrophilic functional groups may also form salts.

Examples of commercially available products of the aqueous polyaminobenzene sulfonic acid solution include products under the trade name "aquaPASS" manufactured by mitsubishi yang corporation.

The antistatic layer disclosed herein contains polyaminobenzene sulfonic acid (polyaniline type) as an essential component as a conductive polymer component, but may also contain 1 or 2 or more other antistatic components (organic conductive materials other than conductive polymers, inorganic conductive materials, antistatic agents, etc.), for example. Here, as a preferable aspect, an aspect in which the antistatic layer does not substantially contain an antistatic component other than the conductive polymer, that is, an aspect in which the antistatic component contained in the antistatic layer is substantially formed only of the conductive polymer may be more preferably implemented.

Examples of the organic conductive material include quaternary ammonium salts, pyridinium salts, and cationic antistatic agents having a cationic functional group such as a primary amino group, a secondary amino group, or a tertiary amino group; anionic antistatic agents having anionic functional groups such as sulfonic acid salts, sulfuric acid ester salts, phosphonic acid salts, and phosphoric acid ester salts; amphoteric antistatic agents such as alkylbetaines and derivatives thereof, imidazolines and derivatives thereof, and alanines and derivatives thereof; nonionic antistatic agents such as aminoalcohol and its derivatives, glycerin and its derivatives, polyethylene glycol and its derivatives, and the like; an ion-conductive polymer obtained by polymerizing or copolymerizing the cationic, anionic, or zwitterionic monomer having an ion-conductive group (for example, a quaternary ammonium salt group); and conductive polymers such as polythiophene, polyaniline, polypyrrole, polyethyleneimine, and allylamine polymers. Such antistatic agents may be used alone in 1 kind, or 2 or more kinds may be used in combination.

Examples of the inorganic conductive material include tin oxide, antimony oxide, indium oxide, cadmium oxide, titanium oxide, zinc oxide, indium, tin, antimony, gold, silver, copper, aluminum, nickel, chromium, titanium, iron, cobalt, copper iodide, ITO (indium oxide/tin oxide), ATO (antimony oxide/tin oxide), and the like. Such inorganic conductive material can be used alone in 1, can also be used in 2 or more combination.

Examples of the antistatic agent include cationic antistatic agents, anionic antistatic agents, zwitterionic antistatic agents, nonionic antistatic agents, and ion-conductive polymers obtained by polymerizing or copolymerizing monomers having the cationic, anionic, and zwitterionic ion-conductive groups.

< adhesive >

The antistatic layer preferably contains a polyester resin as a binder. The polyester resin is preferably a resin material containing a polyester as a main component (typically, a component accounting for more than 50 mass%, preferably 75 mass% or more, for example, 90 mass% or more). The polyester, typically, preferably has the following structure: a structure obtained by condensing 1 or 2 or more compounds (polycarboxylic acid component) selected from polycarboxylic acids (typically dicarboxylic acids) having 2 or more carboxyl groups in 1 molecule and derivatives thereof (anhydrides, esters, halides, and the like of the polycarboxylic acids) with 1 or 2 or more compounds (polyol component) selected from polyhydric alcohols (typically glycols) having 2 or more hydroxyl groups in 1 molecule.

Examples of the compound which can be used as the polycarboxylic acid component include oxalic acid, malonic acid, difluoromalonic acid, alkylmalonic acid, succinic acid, tetrafluorosuccinic acid, alkylsuccinic acid, (±) -malic acid, meso-tartaric acid, itaconic acid, maleic acid, methylmaleic acid, fumaric acid, methylfumaric acid, acetylenedicarboxylic acid, glutaric acid, hexafluoroglutaric acid, methylglutaric acid, glutaconic acid, aliphatic dicarboxylic acids such as adipic acid, dithioadipic acid, methyladipic acid, dimethyladipic acid, tetramethyladipic acid, methyleneadipic acid, muconic acid, galactaric acid, pimelic acid, suberic acid, perfluorosuberic acid, 3,6, 6-tetramethylsuberic acid, azelaic acid, sebacic acid, perfluorosebacic acid, tridecanedioic acid, dodecanedicarboxylic acid, tridecanedicarboxylic acid, and tetradecanedicarboxylic acid; alicyclic dicarboxylic acids such as cycloalkyldicarboxylic acids (e.g., 1, 4-cyclohexanedicarboxylic acid, 1, 2-cyclohexanedicarboxylic acid), 1,4- (2-norbornene) dicarboxylic acid, 5-norbornene-2, 3-dicarboxylic acid (bicycloheptene dicarboxylic acid), adamantanedicarboxylic acid, and spiroheptane dicarboxylic acid; phthalic acid, isophthalic acid, dithioisophthalic acid, methylisophthalic acid, dimethylisophthalic acid, chloromisophthalic acid, dichloroisophthalic acid, terephthalic acid, methylterephthalic acid, dimethylterephthalic acid, chloroterephthalic acid, bromoterephthalic acid, naphthalenedicarboxylic acid, fluorenone dicarboxylic acid, anthracene dicarboxylic acid, biphenyldicarboxylic acid, biphenylenedicarboxylic acid, dimethylbiphenylenedicarboxylic acid, 4 '-p-tetraphenyldicarboxylic acid (4, 4' -p-terphenylene dicarboxylic acid), 4 '-p-quaterphenyldicarboxylic acid (4, 4' -p-quaterphenylene dicarboxylic acid), bibenzyldicarboxylic acid, azobenzenedicarboxylic acid, homophthalic acid, phenylenediacetic acid, phenylenedipropionic acid, naphthalenedicarboxylic acid, biphenyldiacetic acid, biphenyldipropionic acid, biphenyldiacetic acid, and biphenyldipropionic acid, Aromatic dicarboxylic acids such as 3,3' - [4,4 ' - (methylenebis-p-biphenylene) dipropionic acid, 4 ' -bibenzyldiacetic acid, 3' (4,4 ' -bibenzyl) dipropionic acid, oxydi-p-phenylenediacetic acid, etc.; anhydrides of any of the above polycarboxylic acids; esters (e.g., alkyl esters, monoesters, diesters, etc.) of any of the above polycarboxylic acids; acid halides corresponding to any of the above polycarboxylic acids (e.g., dicarboxylic acid chlorides); and the like.

Suitable examples of the compound that can be used as the polycarboxylic acid component include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid, and anhydrides thereof; aliphatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, succinic acid, fumaric acid, maleic acid, bicycloheptene dicarboxylic acid and 1, 4-cyclohexanedicarboxylic acid, and anhydrides thereof; and lower alkyl esters of the above dicarboxylic acids (for example, esters with monohydric alcohols having 1 to 3 carbon atoms).

On the other hand, examples of the compound that can be used as the polyol component include glycols such as ethylene glycol, propylene glycol, 1, 2-propanediol, 1, 3-butanediol, 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-1, 3-propanediol, 2-diethyl-1, 3-propanediol, 2-butyl-2-ethyl-1, 3-propanediol, xylylene glycol (xylylene glycol), hydrogenated bisphenol a, and bisphenol a. Other examples thereof include alkylene oxide adducts (e.g., ethylene oxide adducts, propylene oxide adducts, etc.) of these compounds.

The molecular weight of the polyester resin may be, for example, 5 × 10 as a weight average molecular weight (Mw) in terms of standard polystyrene measured by Gel Permeation Chromatography (GPC)³～1.5×10⁵Left and right (preferably 1 × 10)⁴～6×10⁴Left and right). The glass transition temperature (Tg) of the polyester resin may be, for example, 0 to 120 ℃ (preferably 10 to 80 ℃).

As the polyester resin, there can be used commercially available product name "VYLONAL MD-1480" manufactured by Toyo Boseki Co.

The antistatic layer (topcoat layer) may further contain a resin other than a polyester resin (for example, 1 or 2 or more resins selected from acrylic resins, acrylic-urethane resins, acrylic-styrene resins, acrylic-silicone resins, polyurethane resins, fluorine resins, polyolefin resins, and the like) as a binder, as long as the performance (for example, antistatic performance and other performance) of the pressure-sensitive adhesive sheet (surface protective film) disclosed herein is not significantly impaired. One preferred mode of the technology disclosed herein is: the binder of the antistatic layer is substantially formed only of the polyester resin. For example, the antistatic layer is preferably formed such that the polyester resin accounts for 98 to 100 mass% of the binder. The proportion of the binder in the entire antistatic layer may be, for example, 50 to 95 mass%, and is preferably 60 to 90 mass%.

< Lubricant >)

The antistatic layer (topcoat) preferably uses a fatty acid amide as a lubricant. By using a fatty acid amide as the lubricant, an antistatic layer (top coat layer) having both sufficient slidability and print adhesion can be obtained even in an embodiment in which no 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 the applied peeling treatment agent) is performed on the surface of the antistatic layer, and thus, this embodiment can be a preferable embodiment. In this manner, a mode in which no further peeling treatment is performed on the surface of the antistatic layer is preferable in terms of preventing whitening due to the peeling treatment agent (for example, whitening due to storage under a heated and humidified condition) in advance. Further, it is also advantageous in view of solvent resistance.

Specific examples of the fatty acid amide include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, hydroxystearic acid amide, oleic acid amide, erucic acid amide, N-oleyl palmitic acid amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl erucic acid amide, methylol stearic acid amide, methylene bisstearic acid amide, ethylene bisdecanoic acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbehenic acid amide, hexamethylene bisstearic acid amide, hexamethylene bisbehenic acid amide, hexamethylene hydroxystearic acid amide, N '-distearyl adipic acid amide, N' -distearyl sebacic acid amide, N-stearoyl oleic acid amide, N-stearoyl stearic acid amide, N, Ethylene bis-oleamide, ethylene bis-erucamide, hexamethylene bis-oleamide, N ' -dioleyl adipic acid amide, N ' -dioleyl sebacic acid amide, m-xylylene bis-stearic acid amide, m-xylylene bis-hydroxystearic acid amide, N ' -stearyl isophthalic acid amide, and the like. These lubricants may be used alone in 1 kind, or 2 or more kinds may be used in combination.

The proportion of the lubricant in the entire antistatic layer may be 1 to 50 mass%, and is preferably 5 to 40 mass%. If the content ratio of the lubricant is too small, the sliding property tends to be easily lowered. If the content of the lubricant is too high, the printing adhesion may be reduced.

The technology disclosed herein may be implemented in such a manner that the antistatic layer (topcoat layer) contains a lubricant other than the fatty acid amide, as long as the application effect is not significantly impaired. Examples of the other lubricant include various waxes such as petroleum wax (paraffin wax, etc.), mineral wax (montan wax, etc.), higher fatty acid (cerotic acid, etc.), and neutral fat (palmitic acid triglyceride, etc.). Alternatively, the lubricant may contain a general silicone lubricant, a fluorine lubricant, or the like in addition to the wax. The technique disclosed herein is preferably carried out so as not to substantially contain the silicone-based lubricant, the fluorine-based lubricant, and the like. However, the lubricant does not exclude the silicone compound used for other purposes (for example, an antifoaming agent as a coating material for forming an antistatic layer described later) from being contained within a range not to significantly impair the application effect of the technology disclosed herein.

< crosslinking agent >

The antistatic layer preferably contains an isocyanate-based crosslinking agent as a crosslinking agent. By using the isocyanate-based crosslinking agent, water-soluble polyaminobenzene sulfonic acid as an essential component can be fixed in a binder when forming an antistatic layer, and the effects such as excellent water resistance and improvement of printing adhesion can be achieved.

As the isocyanate-based crosslinking agent, a blocked isocyanate-based crosslinking agent which is stable even in an aqueous solution is preferably used. Specific examples of the blocked isocyanate crosslinking agent include those obtained by blocking an isocyanate crosslinking agent (for example, an isocyanate compound (isocyanate crosslinking agent) used in the adhesive agent layer) used in the production of a general adhesive agent layer or antistatic layer (top coat layer) with an alcohol, a phenol, a thiophenol, an amine, an imide, an oxime, a lactam, an active methylene compound, a thiol, an imine, a urea, a diaryl compound, or sodium hydrogen sulfite.

The antistatic layer in the technology disclosed herein may contain additives such as antistatic components, antioxidants, colorants (pigments, dyes, etc.), fluidity modifiers (thixotropic agents, thickeners, etc.), film-forming aids, surfactants (defoaming agents, etc.), preservatives, and the like, as necessary.

< formation of antistatic layer >

The antistatic layer (top coat layer) can be preferably formed by a method including applying a liquid composition (coating material for forming an antistatic layer, antistatic agent composition) in which components such as the conductive polymer component and additives used as needed are dissolved in an appropriate solvent (water or the like) to the support film. For example, the following method is preferably employed: the coating material is applied to the first surface of the support film, dried, and subjected to curing treatment (heat treatment, ultraviolet treatment, or the like) as necessary. The NV (nonvolatile content) of the coating material may be, for example, 5 mass% or less (typically 0.05 to 5 mass%), and usually 1 mass% or less (typically 0.10 to 1 mass%) is suitable. In the case of forming an antistatic layer having a small thickness, the NV of the coating material is preferably 0.05 to 0.50 mass% (e.g., 0.10 to 0.40 mass%), for example. By using such a low NV coating material, a more uniform antistatic layer can be formed.

As the solvent constituting the coating material for forming an antistatic layer, a solvent capable of stably dissolving the components for forming an antistatic layer is preferable. The solvent may be an organic solvent, water, or a mixed solvent thereof. As the organic solvent, for example, esters selected from ethyl acetate and the like; ketones such as methyl ethyl ketone, acetone, and cyclohexanone; cyclic ethers such as Tetrahydrofuran (THF) and dioxane; aliphatic or alicyclic hydrocarbons such as n-hexane and cyclohexane; aromatic hydrocarbons such as toluene and xylene; aliphatic or alicyclic alcohols such as methanol, ethanol, n-propanol, isopropanol and cyclohexanol; and 1 or 2 or more glycol ethers such as alkylene glycol monoalkyl ether (e.g., ethylene glycol monomethyl ether, ethylene glycol monoethyl ether), and dialkylene glycol monoalkyl ether. 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).

< Property of antistatic layer >

The thickness of the antistatic layer is typically 3 to 500nm, preferably 3 to 100nm, and 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, in the case of the thickness of the antistatic layer, variation in thickness due to position becomes large), and therefore, the appearance of the pressure-sensitive adhesive sheet (surface protective film) may be likely to be uneven. On the other hand, if the thickness is too large, the properties (optical properties, dimensional stability, etc.) of the support film may be affected.

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 preferably less than 1.0 × 10, both after standing at 23 ℃ × 50% RH for 1 day (initial period) and after standing at 70 ℃ (after storage at high temperature over time)¹¹More preferably less than 5.0X 10¹⁰More preferably, it is less than 3.0X 10¹⁰. An adhesive sheet exhibiting a surface resistance value within the above range can be suitably used, for example, as an adhesive sheet used in processing or conveying of an article which is aversive to static electricity, such as a liquid crystal cell or a semiconductor device. Here, the surface resistance value can be calculated from the surface resistance value measured at 23 ℃ and 50% RH using a commercially available insulation resistance measuring apparatus.

The adhesive sheet (surface protective film) disclosed herein preferably has the following properties: the back surface (surface of the antistatic layer) is easily printable with water-based ink or oil-based ink (for example, with an oil-based marker). The pressure-sensitive adhesive sheet is suitable for indicating an identification number or the like of an adherend to be protected on the surface pressure-sensitive adhesive sheet during processing, transportation or the like of the adherend (for example, an optical member) to which the pressure-sensitive adhesive sheet is attached. Therefore, an adhesive sheet having excellent printability is preferable. For example, it is preferable to have high printability to an oil-based ink of a type in which the solvent is alcohol and the pigment is contained. Further, it is preferable that the ink after printing is less likely to be peeled off by rubbing or transfer (that is, excellent printing adhesion). Further, the adhesive sheet disclosed herein preferably has: the solvent resistance is such that the appearance does not change significantly even when the print is erased by alcohol (e.g., ethanol).

The pressure-sensitive adhesive sheet (surface protective film) disclosed herein may be implemented to include other layers in addition to the support film (substrate), the adhesive layer, and the antistatic layer. Examples of the arrangement of the "other layer" include an arrangement between the first surface (back surface) of the support film and the antistatic layer, an arrangement between the second surface (front surface) of the support film and the adhesive layer, and the like. The layer disposed 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). The layer disposed between the front surface of the support film and the adhesive layer may be, for example, an undercoat layer (primer layer) for improving the anchorage of the adhesive layer to the second surface, an antistatic layer, or the like. The adhesive sheet may be one of the following: an antistatic layer is arranged in front of the support film, a primer layer is arranged on the antistatic layer, and an adhesive sheet is arranged on the primer layer.

The optical member of the present invention is preferably an optical member protected by the adhesive sheet. The adhesive sheet can be used for surface protection in processing, transportation, shipment, and the like, and is therefore useful for protecting the surface of the optical member (polarizing plate and the like). In particular, after the treatment with time at a high temperature, there is a problem that the antistatic agent generally penetrates (transfers) to the adherend (optical member or the like) due to the penetration of the antistatic agent into the adherend (optical member or the like) and the antistatic property is poor, but since the optical member of the present invention is protected by the adhesive sheet, when the adhesive sheet (surface protective film) is peeled from the adherend (polarizing plate or the like), a large increase in the peeling electrification voltage is not observed even in comparison with the case of peeling immediately after (initial) bonding, and the peeling electrification stability is excellent even after the storage with time at a high temperature, and therefore, the present invention is very useful for antistatic use in the technical fields relating to optical and electronic members where static electricity is a serious problem.

Examples

Hereinafter, examples and the like specifically showing the configuration and effects of the present invention will be described, but the present invention is not limited thereto. Here, the contents of blending and the evaluation of characteristics in examples and the like were measured as follows. Table 1 shows the physical property values of the (meth) acrylic polymer used in the adhesive composition and the blending ratio of the adhesive composition, table 2 shows the blending content of the antistatic layer, and table 3 shows the evaluation results of the properties.

< evaluation >

Specific measurement and evaluation methods are described below.

< determination of weight average molecular weight (Mw) >)

The weight average molecular weight (Mw) was measured using a GPC apparatus (HLC-8220GPC) manufactured by Tosoh corporation. The measurement conditions were as follows.

Sample concentration: 0.2% by mass (THF solution)

Sample injection amount: 10 μ l

Eluent: THF (tetrahydrofuran)

Flow rate: 0.6 ml/min

Measuring temperature: 40 deg.C

Column:

a sample column; TSK guard column Super HZ-H (1 root) + TSK gel SuperHZM-H (2 roots)

A reference column; TSK gel SuperH-RC (1 root)

A detector: differential refraction detector (RI)

Here, the weight average molecular weight is determined as a polystyrene equivalent.

< theoretical value of glass transition temperature >

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

Formula (II): 1/(Tg +273) ═ Σ [ Wn/(Tgn +273) ]

In the formula, Tg (. degree.C.) represents the glass transition temperature of the copolymer, Wn (-) represents the weight fraction of each monomer, Tgn (. degree.C.) represents the glass transition temperature of a homopolymer of each monomer, and n represents the type of each monomer. Angle (c)

Literature values:

2-ethylhexyl acrylate (2 EHA): -70 deg.C

n-Butyl Acrylate (BA): -55 deg.C

Acrylic Acid (AA): 106 deg.C

2-hydroxyethyl acrylate (HEA): -15 deg.C

4-hydroxybutyl acrylate (HBA): -32 deg.C

N, N-Diethylacrylamide (DEAA): 81 deg.C

Here, as literature values, reference is made to "the synthesis, design, and development of new use of acrylic resins" (published by central business development center), and "Polymer Handbook" (john wiley & Sons).

< measurement of peeled Charge Voltage at initial stage and after high temperature storage over time >

The adhesive sheet was cut into a size of 70mm in width and 130mm in length, and after peeling the separator, the surface (TAC surface) of a TAC polarizing plate (SEG 1423DU polarizing plate, 70mm in width and 100mm in length, manufactured by ritonan electric company) attached to an acrylic plate (2 mm in thickness, 70mm in width and 100mm in length) from which electricity had been removed in advance was pressed with a hand roller so that one end of the adhesive sheet was exposed by 30 mm.

The sample was set at a predetermined position as shown in FIG. 1, after being left at 23 ℃ X50% RH for 1 day (initial peel charge voltage) and after being left at 70 ℃ for 1 week (peel charge voltage after high-temperature storage over time). One end portion exposed to 30mm was fixed to an automatic winder, and peeling was performed at a peeling angle of 150 ° and a peeling speed of 30 m/min (high-speed peeling). The potential (peeling electrification voltage: absolute value, kV) of the surface of the polarizing plate generated at this time was measured by a potential measuring instrument (KSD-1030, manufactured by spring Motor Co.) fixed at the center of the polarizing plate. The measurement was carried out under an atmosphere of 23 ℃ X50% RH.

The TAC surface (polarizing plate surface) was stuck (left) on the adhesive surface of the adhesive layer used in the adhesive sheet under the conditions of 23 ℃ x 50% RH for 1 day, and then peeled (high speed peeling) at a peeling angle of 150 ° and a peeling speed of 30 m/min, and the potential (peeling charge voltage: absolute value, kV) generated on the polarizing plate surface at this time was preferably less than 0.5kV, more preferably 0.4kV or less, and still more preferably 0.3kV or less. If the peeling electrification voltage is 0.5kV or more, for example, damage to a liquid crystal driver or the like is caused, which is not preferable.

The pressure-sensitive adhesive layer used for the pressure-sensitive adhesive sheet is one in which the pressure-sensitive adhesive surface of the pressure-sensitive adhesive layer is attached to (left on) the TAC surface (polarizing plate surface) at 70 ℃ for 1 day, and then peeled off (high-speed peeling) at a peeling angle of 150 DEG and a peeling speed of 30 m/min, and the potential (peeling charge voltage: absolute value, kV) of the polarizing plate surface generated at this time is preferably less than 0.5kV, more preferably 0.4kV or less, and still more preferably 0.3kV or less. If the peeling electrification voltage is 0.5kV or more, for example, damage to a liquid crystal driver or the like is caused, which is not preferable.

< determination of shear force >

The adhesive sheet was cut into a size of 10mm in width and 100mm in length, and after peeling the separator, the adhesive (bonding) area of the adhesive layer of the adhesive sheet was set to 1cm²The sheet was attached to a TAC polarizing plate (SEG 1423DU polarizing plate, width: 25mm, length: 100mm, manufactured by Nidoku electric industries Co., Ltd.), pulled in the shearing direction at a peeling speed of 0.06 mm/min at 23 ℃ to apply the maximum load (N/cm) at that time²) As a shear force.

Here, the shear force (N/cm)²) Preferably 10 or more, more preferably 10 to 50, and still more preferably 10 to 40. When the shear force is within the above range, the adhesive sheet can resist a force in the shear direction generated when the adherend is desired to be curled, and can suppress curling of the adherend without causing slipping or displacement of the adhesive sheet.

< measurement of surface resistance value at initial stage and after high-temperature storage with time >

Measured by a resistivity meter (Mitsubishi chemical Analyticech, Hiresta-UPMCP-HT450 type) at a temperature of 23 ℃ and a humidity of 50% RH according to JIS-K-6911.

Here, the surface resistance value (Ω/□) of the antistatic layer surface in the present invention is preferably less than 1.0X 10, both after 1 day at 23 ℃ X50% RH (initial surface resistance) and after 1 week at 70 ℃ C (surface resistance after storage at high temperature over time)¹¹More preferably less than 5.0X 10¹⁰More preferably, it is less than 3.0X 10¹⁰. An adhesive sheet (surface protective film) exhibiting a surface resistance value within the above range can be suitably used as an adhesive sheet used for processing or carrying of an article which is aversive to static electricity, such as a liquid crystal cell or a semiconductor device.

< measurement of slidability (dynamic frictional force) >

The adhesive sheet (surface protective film) was cut into a size of 70mm in width and 100mm in length, and was bonded to an acrylic plate (product name "ACRYLITE" manufactured by Mitsubishi Yang corporation, thickness: 1mm, width: 70mm, length: 100mm) to prepare a test piece. The test piece was placed with its back surface (antistatic layer surface) facing downward on a smooth PET film kept horizontal, and a load of 1.5kg was applied to the test piece. The test piece loaded with the load was mounted on a tensile tester with a non-stretchable wire, and the test piece was horizontally pulled at a measurement temperature of 25 ℃ under conditions of a pulling speed of 300 mm/min and a pulling distance of 300mm, and the average value (N: 3) of the kinetic friction force (N) applied to the test piece was determined.

Here, the slidability (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. When the amount is within the above range, the treatment of the adherend to which the pressure-sensitive adhesive sheet is attached is advantageous in terms of good slidability and workability of the back surface (antistatic layer surface) of the support film.

< evaluation of printability (print adhesion) >

After printing on the surface of the antistatic layer in a measuring environment of 23 ℃ x 50% RH using an xstamp manufactured by banners, a setlotape (registered trademark) manufactured by mikko corporation was pasted on the printing, and then peeled off under conditions of a peeling speed of 30 m/min and a peeling angle of 180 °.

< preparation method >

Specific methods for producing the (meth) acrylic polymer, the adhesive composition, and the like are described below.

Production of (meth) acrylic Polymer

94.5 parts by mass of 2-ethylhexyl acrylate (2EHA), 5.32 parts by mass of 4-hydroxyethyl acrylate (HEA), 0.18 parts by mass of Acrylic Acid (AA), 0.2 parts by mass of 2, 2' -azobisisobutyronitrile as a polymerization initiator, and 150 parts by mass of ethyl acetate were charged into a four-necked flask equipped with a stirrer, a thermometer, a nitrogen gas inlet tube, and a condenser, and a (meth) acrylic polymer solution (40 mass%) was prepared by introducing nitrogen gas while stirring slowly and performing polymerization reaction for 6 hours while keeping the liquid temperature in the flask at about 65 ℃. The weight average molecular weight of the acrylic polymer was 52 ten thousand, and the glass transition temperature (Tg) was-67 ℃.

< preparation of adhesive composition 1 >

The (meth) acrylic polymer solution (40 mass%) was diluted with ethyl acetate to 20 mass%, 2 parts by mass (2 parts by mass of a solid content) of isocyanurate of hexamethylene diisocyanate (COLONATE HX, manufactured by Nippon polyurethane industries Co., Ltd.) as an aliphatic isocyanate compound as a crosslinking agent, 3 parts by mass (0.03 parts by mass of a solid content) of dibutyltin dilaurate (1 mass% ethyl acetate solution) as a crosslinking catalyst, 0.2 parts by mass of tetrabutylammonium hexafluorophosphate (TBA, melting point 245 ℃ C., manufactured by Tokyo chemical industries Co., Ltd.) as an ionic compound, and 0.2 parts by mass of organopolysiloxane having an oxyalkylene chain (KF-6020, manufactured by shin-Etsu chemical industries Co., Ltd.) as an oxyethylene group-containing compound were added to 500 parts by mass (100 parts by mass of a solid content) of the solution, and mixed and stirred, adhesive composition 1 (solution) was prepared.

< preparation of aqueous solution for antistatic layer (Back treatment agent A) >

Polyester resin VYLONAL MD-1480 (25% aqueous solution, manufactured by toyobo co., ltd.), polyaminobenzene sulfonic acid (aquaPASS, weight average molecular weight 4 ten thousand, manufactured by mitsubishi yang co., ltd.) as a binder, isocyanurate of diisopropylamine-blocked hexamethylene diisocyanate as a crosslinking agent, and oleamide as a lubricant were added to a mixed solvent of water and ethanol (1/3), and the binder was 100 parts by mass in terms of a solid content, the conductive polymer was 75 parts by mass in terms of a solid content, the crosslinking agent was 10 parts by mass in terms of a solid content, and the lubricant was 30 parts by mass in terms of a solid content, and sufficiently mixed by stirring for about 20 minutes. Thus, an aqueous solution of an antistatic layer having an NV of about 0.4% was prepared.

< preparation of aqueous solution for antistatic layer (Back treatment agent B) >

Polyester resin VYLONAL MD-1480 (25% aqueous solution, manufactured by toyobo co., ltd.), polyaminobenzene sulfonic acid (aquaPASS, weight average molecular weight 4 ten thousand, manufactured by mitsubishi yang co., ltd.) as a binder, isocyanurate body of hexamethylene diisocyanate blocked with diisopropylamine as a crosslinking agent were added to a mixed solvent of water/ethanol (1/3), and the mixture was sufficiently mixed by stirring for about 20 minutes, with the binder being 100 parts by mass in terms of solid content, the conductive polymer being 75 parts by mass in terms of solid content, and the crosslinking agent being 10 parts by mass in terms of solid content. Thus, an aqueous solution of 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 VYLONAL MD-1480 (25% aqueous solution, manufactured by toyobo co., ltd.), aqueous solution (bytron p, h.c. stark co., ltd.) containing 0.5% of poly (3, 4-ethylenedioxythiophene) (PEDOT) and 0.8% of polystyrene sulfonate (weight average molecular weight 15 ten thousand) (PSS) as conductive polymers, isocyanurate body of hexamethylene diisocyanate blocked with diisopropylamine as a crosslinking agent were added to a mixed solvent of water/ethanol (1/1), and the mixture was thoroughly mixed with stirring for about 20 minutes, wherein the binder was 100 parts by mass in terms of solid content, the conductive polymer was 50 parts by mass in terms of solid content, and the crosslinking agent was 10 parts by mass in terms of solid content. Thus, an aqueous solution of 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 VYLONAL MD-1480 (25% aqueous solution, manufactured by toyoyo textile) as a binder and polyaminobenzene sulfonic acid (aqua pass, weight average molecular weight 4 ten thousand, manufactured by mitsubishi yang corporation) as a conductive polymer were added to a mixed solvent of water/ethanol (1/3), and the mixture was stirred for about 20 minutes to be sufficiently mixed, wherein the binder was 100 parts by mass in terms of solid content and the conductive polymer was 75 parts by mass in terms of solid content. Thus, an aqueous solution of an antistatic layer having an NV of about 0.4% was prepared.

< preparation of support film with antistatic layer >

An aqueous solution of any of the antistatic layers (back surface treatment agents A to D) was applied to a transparent polyethylene terephthalate (PET) film (polyester film: support film) having a thickness of 38 μm, a width of 30cm and a length of 40cm, which was subjected to corona treatment on one surface (first surface), so that the thickness after drying was 30 nm. The coating was heated at 130 ℃ for 1 minute and dried to prepare an antistatic-layer-provided support film having an antistatic layer on the first surface of the PET film.

< example 1 >

< preparation of adhesive sheet >

The pressure-sensitive adhesive composition 1 (solution) was applied to the surface of the antistatic layer-equipped support film opposite to the antistatic layer, and heated at 130 ℃ for 1 minute to form a pressure-sensitive adhesive layer having a thickness of 15 μm. The silicone-treated surface of a polyethylene terephthalate film (thickness: 25 μm), which was a separator having silicone-treated on one surface, was bonded to the surface of the adhesive layer to form an adhesive sheet (surface protective film).

< examples 2 to 14 and comparative examples 1 to 3 >

Adhesive sheets were produced in the same manner as in example 1 based on the blending ratios in tables 1 and 2. Here, the blending amount in table 1 indicates the solid content.

The pressure-sensitive adhesive sheet thus produced was measured for peel charged voltage at the initial stage and after high-temperature aging, shear force, surface resistance value at the initial stage and after high-temperature aging, slidability, and print adhesion by the above evaluation methods. The results obtained are shown in Table 3.

TABLE 1

TABLE 2

	Conductive polymer	Adhesive agent	Crosslinking agent	Lubricant agent
					Back surface treating agent A	Polyaminobenzene sulfonic acid	Polyester	Isocyanates	Oleic acid amides
Back surface treating agent B	Polyaminobenzene sulfonic acid	Polyester	Isocyanates	-
					Back surface treating agent C	PEDOT/PSS	Polyester	Isocyanates	-
Back surface treating agent D	Polyaminobenzene sulfonic acid	Polyester	-	-

The following are descriptions of abbreviations in table 1 and table 2.

2 EHA: 2-ethylhexyl acrylate

BA: acrylic acid n-butyl ester

AA: acrylic acid (carboxyl group-containing (meth) acrylic acid monomer)

HEA: 2-hydroxyethyl acrylate (hydroxyl group-containing (meth) acrylic monomer)

HBA: acrylic acid 4-hydroxybutyl ester (hydroxyl group-containing (meth) acrylic acid series monomer)

DEAA: n, N-diethyl acrylamide

C/L: aromatic isocyanate Compound, trimethylolpropane/tolylene diisocyanate (product name: COLONATE L, manufactured by NIPPON POLYURETHANE INDUSTRIAL CO., LTD.)

C/HX: aliphatic isocyanate Compound and isocyanurate of hexamethylene diisocyanate (product name: COLONATE HX, manufactured by Nippon polyurethane Co., Ltd.)

TMHA: trimethylhexylammonium bistrifluoromethanesulfonylimide (melting point: 35 ℃ C.) (manufactured by Kishida chemical Co., Ltd., ionic compound)

HP: 2-Hexylpyridinium hexafluorophosphate (melting point: 45 ℃ C.) (manufactured by Kishida chemical Co., Ltd., ionic compound)

BMP: 1-butyl-4-methylpyridinium hexafluorophosphate (melting point 42 ℃ C.) (Ionic Compound manufactured by Tokyo chemical industries Co., Ltd.)

MEIM: 1-methyl-3-ethylimidazolium hexafluorophosphate (melting point 61 ℃ C.) (Ionic Compound manufactured by Tokyo chemical industry Co., Ltd.)

BP: 1-Butylpyridinium hexafluorophosphate (melting point 75 ℃ C.) (Ionic Compound manufactured by Tokyo chemical industries Co., Ltd.)

TBA: tetrabutylammonium hexafluorophosphate (melting point 245 ℃) (Ionic Compound manufactured by Tokyo chemical Co., Ltd.)

KF 6020: organopolysiloxane having oxyalkylene chain (HLB value 4) (product name: KF-6020, manufactured by shin-Etsu chemical Co., Ltd.)

KF 353: organopolysiloxane having oxyalkylene chain (HLB value 10) (product name: KF-353, product of shin-Etsu chemical Co., Ltd.)

KF 355A: organopolysiloxane having oxyalkylene chain (HLB value 12) (product name: KF-355A, product of shin-Etsu chemical Co., Ltd.)

EO group-containing Compound: oxyethylene group-containing compound (compound having oxyalkylene chain)

PEDOT: conductive polymer, poly (3, 4-ethylenedioxythiophene)

PSS: conductive polymer and polystyrene sulfonate

TABLE 3

Note) that "> 1E + 13" in Table 3 indicates that the upper limit value measurable by a resistivity meter is exceeded.

From the results of table 3, it was confirmed that the peel charging voltage (peel charging stability after high-temperature storage) after high-temperature storage (after 1 week at 70 ℃) was excellent in all of the examples. On the other hand, it was confirmed that in comparative examples 1 and 2, which did not contain an ionic compound, the peel charge voltage was high from the initial stage, and the peel charge voltage was still high even when the high-temperature storage time passed. The shear force is excellent. In comparative example 3, although containing an ionic compound, it was confirmed that the surface resistance value after storage at high temperature over time was poor and the peel charge voltage after storage at high temperature over time was also poor. In all comparative examples, the shear force was poor.

Further, according to the results shown in Table 3, the adhesive sheets of examples 1 to 5, 7 to 11 and 13, which had antistatic layers using the back surface treatment agent A prepared by blending desired raw materials (conductive polymer component: polyaminobenzene sulfonic acid, binder: polyester resin, and crosslinking agent: isocyanate-based crosslinking agent) as antistatic layers (antistatic agent composition), satisfied all the evaluation items of surface resistance, sliding property and printing adhesion due to the antistatic layers. On the other hand, the antistatic layer using the back surface treatment agents B to D partially produced without blending the desired raw materials was confirmed to be an antistatic layer that did not satisfy all evaluation items of surface resistance, slidability, and print adhesion due to the antistatic layer.

Description of the symbols

1 electric potential measuring device

2 adhesive sheet

3 polarizing plate

4 acrylic plate

5 fixed station

Claims (5)

1. An adhesive sheet characterized by having an adhesive layer comprising an adhesive composition on one surface of a support film,

the adhesive composition contains a (meth) acrylic polymer, a compound having an oxyalkylene chain, and an ionic compound having an organic cation which is solid at ordinary temperature of 25 ℃,

5.1% by mass or more of a hydroxyl group-containing (meth) acrylic monomer based on the total amount of monomers constituting the (meth) acrylic polymer,

the absolute value of the peeling electrostatic voltage at the peeling speed of 30 m/min after the adhesive surface of the adhesive layer is adhered to the TAC surface for 1 week at 70 ℃ is less than 0.5kV,

an antistatic layer is provided on one surface of the support film on the opposite side of the adhesive layer,

the antistatic layer is formed from an antistatic agent composition containing polyaniline sulfonic acid as a conductive polymer component, a polyester resin as a binder, and an isocyanate-based crosslinking agent as a crosslinking agent.

2. The adhesive sheet according to claim 1,

the compound having an oxyalkylene chain is an organopolysiloxane having an oxyalkylene chain.

3. The adhesive sheet according to claim 1,

the adhesive composition contains a (meth) acrylic polymer having a hydroxyl group and a carboxyl group.

4. The adhesive sheet according to claim 1,

the antistatic agent composition further contains a fatty acid amide as a lubricant.

5. An optical component characterized in that,

protected by the adhesive sheet according to any one of claims 1 to 4.

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