TWI827544B - Adhesive compositions, surface protection sheets and optical components - Google Patents

Abstract

The present invention provides an adhesive composition that can form a surface protection sheet that can suppress the generation of static electricity on an adherend even when the surface protection sheet is peeled off from the adherend in a low-temperature environment, the above-mentioned surface protection sheet and the above-mentioned surface protection sheet adhered Optical components made of surface protection sheets. The adhesive composition of the present invention is characterized by containing an onium salt with a melting point of -4°C or lower and a polymer with a glass transition temperature of 0°C or lower as a base polymer, and the above-mentioned onium salt is selected from nitrogen-containing compounds. At least one of the group consisting of onium salts, sulfonium salts and phosphorus-containing onium salts.

Description

Adhesive compositions, surface protection sheets and optical components

Field of the Invention The present invention relates to an adhesive composition, a surface protection sheet, and an optical member protected by the surface protection sheet.

The surface protection sheet formed from the adhesive composition of the present invention can be used to protect the surface of optical components such as polarizing films, wavelength plates, phase difference plates, optical compensation films, reflective sheets, and brightness enhancement films used in liquid crystal displays and the like. used for the purpose.

BACKGROUND OF THE INVENTION In recent years, when optical components and electronic components are transported or actually mounted on a printed circuit board, each component is transported in a state of being packaged with a predetermined sheet or in a state with an adhesive tape attached. Among them, surface protection sheets are particularly widely used in the fields of optical and electronic components.

The surface protection sheet is usually attached to the adherend (object to be protected) through an adhesive coated on the side of the supporting film. It is used to prevent damage or stains on the adherend during processing and transportation. (Patent document 1). For example, a panel of a liquid crystal display is formed by bonding optical components such as a polarizing film and a wavelength plate to a liquid crystal cell via an adhesive. These optical components are bonded with surface protection films via adhesives to prevent damage or stains to the adherends during processing and transportation. Then, the surface protective sheet is peeled off and removed at a stage when the protective sheet is no longer needed.

Generally, surface protection sheets and optical components are made of plastic materials and therefore have high electrical insulation properties, and static electricity is generated when rubbed or peeled off. Especially in a low-temperature environment with low humidity, when peeling the surface protection sheet from the adherend (polarizing film, etc.), the peeling charging voltage tends to increase, and it is easy to peel the surface protection sheet from the adherend. Generate static electricity. For example, when the surface protective sheet is peeled off from the optical components (polarizing film, etc.) of a liquid crystal display, the static electricity generated during peeling causes the liquid crystal molecules to be oriented disorderly, which occurs during the black display test during the display inspection of the display. A display defect called white unevenness occurs when a part of the white display is partially white, making display inspection impossible. Prior art documents Patent documents

Patent Document 1: Japanese Patent Application Laid-Open No. 9-165460

SUMMARY OF THE INVENTION Problems to be Solved by the Invention Therefore, an object of the present invention is to solve the problems in the existing surface protection sheets and provide a surface protection sheet capable of inhibiting adhesion even when the surface protection sheet is peeled off from the adherend in a low-temperature environment. An adhesive composition of a surface protection sheet generated by static electricity of stickies, the above-mentioned surface protection sheet, and an optical member to which the above-mentioned surface protection sheet is adhered. Means used to solve problems

That is, the adhesive composition of the present invention is characterized in that the adhesive composition contains an onium salt with a melting point of -4°C or less and a polymer as a base polymer with a glass transition temperature of 0°C or less, and The above-mentioned onium salt is at least one selected from the group consisting of nitrogen-containing onium salts, sulfur-containing onium salts and phosphorus-containing onium salts.

The adhesive composition of the present invention preferably contains a compound having an alkylene oxide group.

In the adhesive composition of the present invention, it is preferable that the polymer having a glass transition temperature of 0° C. or less is a (meth)acrylic polymer having a hydroxyl group and/or a carboxyl group.

The surface protection sheet of the present invention preferably has an adhesive layer formed of the above-mentioned adhesive composition on one side of the support film.

The surface protection sheet of the present invention preferably has an antistatic layer on the opposite side to the adhesive layer to be formed on the support film, and the antistatic layer is made of polyaniline and/or polythiophene as a conductive layer. An antistatic agent composition of polymer components is formed.

The optical member of the present invention is preferably protected by the above-mentioned surface protection sheet.

The optical member of the present invention is preferably a polarizing film including a polarizer, and the thickness of the polarizer is 8 μm or less.

Effects of the Invention The surface protection sheet formed of the adhesive composition of the present invention is useful in that it can suppress the generation of static electricity on the adherend when the surface protection sheet is peeled off from the adherend even in a low-temperature environment.

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, embodiments of the present invention will be described in detail.

<The overall structure of the surface protection sheet> The surface protection sheet of the present invention is generally in the form of a surface protection sheet, a surface protection tape, a surface protection film, etc., and is particularly suitable as an optical member (such as a polarizing film, a wavelength plate, etc.) A surface protection sheet that protects the surface of optical components used as components of liquid crystal display panels during processing or transportation. The adhesive layer in the surface protection sheet is typically formed continuously, but is not limited to this form. For example, the adhesive layer may be formed in a regular or irregular pattern such as dots or stripes. In addition, the surface protection sheet disclosed here may be in roll form or in paper form (leaf form).

Typical structural examples of the surface protection sheet disclosed here include a surface protection sheet having an adhesive layer on one side of a support film (base material), a surface protection sheet having an adhesive layer on one side of the support film, and a surface protection sheet having an adhesive layer on one side of the support film. A surface protection sheet that supports the antistatic layer on the opposite side of the film to the adhesive layer. The surface protection sheet is used by adhering the adhesive layer to an adherend (protection target, the surface of an optical member such as a polarizing film). The surface protection sheet before use (that is, before sticking to the adherend) may be in a form in which the surface of the adhesive layer (the surface stuck to the adherend) is protected by a release liner with at least the adhesive layer side being the release surface. Alternatively, the surface protection sheet may be wound into a roll shape so that the adhesive layer comes into contact with the back surface of the support film (antistatic layer surface) so that the surface thereof is protected.

<Adhesive composition> The adhesive composition of the present invention is characterized by containing an onium salt with a melting point of -4°C or lower and a polymer having a glass transition temperature of 0°C or lower as a base polymer, and the onium salt is selected from At least one of the group consisting of nitrogen-containing onium salts, sulfur-containing onium salts and phosphorus-containing onium salts. As the above-mentioned adhesive composition, as long as it contains the above-mentioned onium salt with a melting point of -4°C or lower and a base polymer with the above-mentioned glass transition temperature (Tg) of 0°C or lower, and can express adhesiveness, It can be used without special restrictions. For example, acrylic adhesives, polyurethane adhesives, polyester adhesives, synthetic rubber adhesives, natural rubber adhesives, polysiloxane adhesives, etc. using the above-mentioned base polymers can be used. Among these, acrylic adhesives are particularly preferred from the viewpoint of easy control of adhesive properties.

In the present invention, the polymer having a glass transition temperature (Tg) of 0° C. or less is preferably a (meth)acrylic polymer, and more preferably a (meth)acrylic polymer having a hydroxyl group and/or a carboxyl group. By using the above-mentioned polymer having a glass transition temperature (Tg) of 0°C or lower, an adhesive having excellent adhesive properties can be designed. In addition, by using the above-mentioned (meth)acrylic polymer, the adhesive properties can be easily controlled. is the preferred aspect. In addition, by using the above-mentioned (meth)acrylic polymer having a hydroxyl group and/or a carboxyl group, cross-linking can be easily controlled by the hydroxyl group, and the carboxyl group can increase shear force or prevent an increase in adhesive force over time. , so it is the preferred aspect. In particular, by using the above-mentioned (meth)acrylic polymer having a hydroxyl group and/or a carboxyl group, the shear force of the adhesive (layer) is increased. Therefore, by bonding the above-mentioned adhesive to an adherend, it is possible to suppress The curling of the adherend is preferred because it can prevent slippage or deviation between the adhesive and the adherend (interface).

Furthermore, in the present invention, the polymer having the above-mentioned glass transition temperature (Tg) of 0° C. or less is contained as a base polymer, and a more preferred aspect is: in 100% by mass of the above-mentioned base polymer, the above-mentioned glass transition temperature (Tg ) is 100% by mass of polymers below 0°C. In addition, the (meth)acrylic polymer in the present invention means an acrylic polymer and/or a methacrylic polymer, and the (meth)acrylate means an acrylate and/or a methacrylate.

Moreover, it is preferable that the said (meth)acrylic polymer contains the said hydroxyl-containing (meth)acrylic monomer as a monomer component. By using the above-mentioned hydroxyl-containing (meth)acrylic monomer, it is easy to control the crosslinking of the adhesive composition, etc., and further it is easy to control the improvement of wettability due to flow and the cohesive force and shear force of the adhesive (layer). balance. In addition, when an antistatic agent is added to the adhesive, unlike the carboxyl group, sulfonic acid group, etc. that usually function as cross-linking sites, the hydroxyl group and the onium salt as the antistatic agent have a melting point of -4°C or less. etc. have moderate interaction, so they can also function appropriately in terms of antistatic properties.

In the present invention, the hydroxyl-containing (meth)acrylic monomer is preferably contained in an amount of 0.1% to 20% by mass, and more preferably 0.5% by mass, based on the total amount of monomer components constituting the (meth)acrylic polymer. ~15 mass%, more preferably 0.75 mass% to 13 mass%, most preferably 1 mass% to 10 mass%. Within the above range, it is easy to control the balance between the wettability of the adhesive composition and the cohesive force and shear force of the adhesive (layer), which is preferable. In addition, in order to exhibit good charging characteristics with a smaller blending amount of the onium salt, it is effective to have a smaller blending amount of the hydroxyl-containing (meth)acrylic monomer.

Examples of the hydroxyl-containing (meth)acrylic monomer include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. , 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, (4-hydroxyacrylate) Methylcyclohexyl)methyl ester, N-hydroxymethyl (meth)acrylamide, etc. In addition, the above-mentioned hydroxyl-containing (meth)acrylic monomer may be used alone, or two or more types may be used as monomer components.

Moreover, it is preferable that the said (meth)acrylic polymer contains the said carboxyl group-containing (meth)acrylic monomer as a monomer component. By using the above-mentioned carboxyl group-containing (meth)acrylic monomer, it is possible to suppress the increase in the adhesive force of the surface protective sheet (adhesive layer) over time, and it is excellent in re-peelability, anti-adhesion increase resistance and workability. In addition, The adhesive layer also has excellent cohesive force and shear force, which is preferred.

In the present invention, the carboxyl group-containing (meth)acrylic monomer is preferably contained in an amount of 0.001% to 0.5% by mass, and more preferably 0.002% by mass, based on the total amount of monomer components constituting the (meth)acrylic polymer. ~0.4 mass%, more preferably 0.003 mass% to 0.3 mass%, still more preferably 0.004 mass% to 0.2 mass%, most preferably 0.005 mass% to 0.1 mass%. When it is within the above range, the increase in adhesion over time can be suppressed, and the re-peelability, prevention of increase in adhesion and workability can be excellent. In addition, the adhesive layer also has excellent cohesive force and shear force, which is preferable. Furthermore, when acidic functional groups such as carboxyl groups with high polarity are present in large amounts, when an onium salt, etc., with a melting point of -4°C or lower that can be used as an antistatic agent is blended, the acidic functional groups such as carboxyl groups interact with the onium salts, etc. It hinders ion conduction, reduces conductive efficiency, and may not be able to obtain sufficient antistatic properties, so it is not preferred.

Examples of the carboxyl group-containing (meth)acrylic monomer include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, and 2-hexahydrophthalic acid. (Meth)acryloxyethyl ester, 2-(meth)acryloxypropyl hexahydrophthalate, 2-(meth)acryloxyethyl phthalate, 2-succinic acid -(Meth)acryloxyethyl ester, 2-(meth)acryloxyethyl maleate, carboxypolycaprolactone mono(meth)acrylate, tetrahydrophthalic acid 2-( Methyl acryloyloxyethyl ester, etc. In addition, the above-mentioned carboxyl group-containing (meth)acrylic monomers may be used alone, or two or more types may be used as monomer components.

In addition, in the present invention, it is preferable that the (meth)acrylic polymer uses a (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms as a monomer component, and more preferably one having an alkyl group having 4 to 14 carbon atoms. 14 alkyl (meth)acrylic monomer. The above-mentioned (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms may be used alone, or two or more types may be used as a monomer component.

Specific examples of the (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms include methyl (meth)acrylate, ethyl (meth)acrylate, and (meth)acrylate. n-butyl acrylate, secondary butyl (meth)acrylate, tertiary butyl (meth)acrylate, isobutyl (meth)acrylate, hexyl (meth)acrylate, 2-ethyl (meth)acrylate Hexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, ( Isodecyl methacrylate, n-dodecyl (meth)acrylate, n-tridecyl (meth)acrylate, n-tetradecyl (meth)acrylate, etc.

Among these, examples of the surface protection sheet of the present invention include hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, and isooctyl (meth)acrylate. Ester, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate, (Meth)acrylates having an alkyl group having 6 to 14 carbon atoms, such as n-tridecyl (meth)acrylate and n-tetradecyl (meth)acrylate, are preferred examples. By using a (meth)acrylate having an alkyl group having 6 to 14 carbon atoms, it is easy to control the adhesive force to an adherend to be low, thereby obtaining a surface protection sheet excellent in removability.

In the present invention, it is preferable that the (meth)acrylic acid containing the alkyl group having 1 to 14 carbon atoms contains 50% by mass to 99% by mass relative to the total amount of monomer components constituting the (meth)acrylic polymer. The monomer-like content is more preferably 60 mass% to 98.8 mass%, further preferably 70 mass% to 98.6 mass%, and most preferably 80 mass% to 98.5 mass%. By being within the above range, the adhesive composition has moderate wettability and the adhesive (layer) has excellent cohesive force, which is preferable.

In addition, other polymerizable monomer components may be used so that the glass transition temperature (Tg) is 0°C or lower (usually -100 °C or above) to adjust the Tg or peelable polymerizable monomer of the above-mentioned (meth)acrylic polymer.

As the (meth)acrylic polymer used in the above-mentioned (meth)acrylic polymer, in addition to the above-mentioned hydroxyl group-containing (meth)acrylic monomer, carboxyl group-containing (meth)acrylic monomer and (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms, Polymerizable monomers other than acrylic monomers can be used without particular limitation as long as they do not impair the characteristics of the present invention. For example, components such as cyano group-containing monomers, vinyl ester monomers, aromatic vinyl monomers, etc. that improve cohesion/heat resistance can be appropriately used; amide group-containing monomers, amide group-containing monomers, amine group-containing monomers, etc. Monomer, epoxy group-containing monomer, N-acrylyl group Components such as pholine and vinyl ether monomers that improve adhesion (adhesion) or have functional groups that function as cross-linking base points; peeling force-adjusting components such as oxidized alkylene group-containing monomers. These polymerizable monomers may be used individually or in mixture of two or more types.

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

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

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

Examples of the above-mentioned amide group-containing monomer include acrylamide, methacrylamide, diethyl acrylamide, N-vinylpyrrolidone, N,N-dimethylacrylamide, N,N-dimethylmethacrylamide, N,N-diethylmethacrylamide, N,N-diethylmethacrylamide, N,N'-methylenebisacrylamide, N,N-dimethylaminopropyl acrylamide, N,N-dimethylaminopropyl methacrylamide, diacetone acrylamide, N-methyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N-tertiary butyl(meth)acrylamide, N,N-dipropylacrylamide, N,N-diisopropyl(methyl) Acrylamide, N,N-dibutyl(meth)acrylamide, N-ethyl-N-methyl(meth)acrylamide, N-methyl-N-propyl(meth)propylene Amide, N-methyl-N-isopropyl(meth)acrylamide, N-hydroxymethylacrylamide, diacetone acrylamide, N-vinyl acetamide, N,N'-amide Methylbisacrylamide, N,N-diethylaminopropyl(meth)acrylamide, N,N-dipropylaminopropyl(meth)acrylamide, N,N-di Isopropylaminopropyl(meth)acrylamide, N-ethyl-N-methylaminopropyl(meth)acrylamide, N-methyl-N-propylaminopropyl( Methyl acrylamide, N-methyl-N-isopropylaminopropyl(meth)acrylamide, N-vinyl acetamide, N-vinyl-N-methyl acrylamide, N-methoxymethyl(meth)acrylamide, N-ethoxyethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide, N-vinylhexane Lactam, etc.

Examples of the above-mentioned amide group-containing monomer include cyclohexylmaleimide, isopropylmaleimide, N-cyclohexylmaleimide, and itaconidimine.

Examples of the above-mentioned amine group-containing monomer include aminoethyl (meth)acrylate, N,N-dimethylaminomethyl (meth)acrylate, and N,N-dimethylacrylate (meth)acrylate. Methylaminoethyl ester, (meth)acrylic acid N,N-dimethylaminopropyl ester, (meth)acrylic acid N,N-dimethylaminoisopropyl ester, (meth)acrylic acid N,N -Dimethylaminobutyl ester, (meth)acrylic acid N,N-diethylaminomethyl ester, (meth)acrylic acid N,N-diethylaminoethyl ester, (meth)acrylic acid N- Ethyl-N-methylaminoethyl ester, N-methyl-N-propylaminoethyl (meth)acrylate, N-methyl-N-isopropylaminoethyl (meth)acrylate , N,N-dibutylaminoethyl (meth)acrylate, tertiary butylaminoethyl (meth)acrylate, etc.

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

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

Examples of the oxyalkylene group-containing monomer include methoxypolyethylene such as methoxydiethylene glycol (meth)acrylate and methoxytriethylene glycol (meth)acrylate. Glycol (meth)acrylate type; ethoxypolyethylene glycol (meth)acrylate such as ethoxydiethylene glycol (meth)acrylate and ethoxytriethylene glycol (meth)acrylate Ester type; butoxy polyethylene glycol (meth)acrylate type such as butoxydiethylene glycol (meth)acrylate, butoxytriethylene glycol (meth)acrylate; phenoxydiethylene glycol (meth)acrylate type Phenoxy polyethylene glycol (meth)acrylate type such as ethylene glycol (meth)acrylate and phenoxytriethylene glycol (meth)acrylate; 2-ethylhexyl polyethylene glycol (meth)acrylate acrylate, nonylphenol polyethylene glycol (meth)acrylate type; methoxydipropylene glycol (meth)acrylate and other methoxypolypropylene glycol (meth)acrylate type, etc.

In the present invention, the above-mentioned (meth)acrylic monomers 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 The polymerizable monomer is preferably 0 to 40% by mass, and more preferably 0 to 30% by mass of the total amount of monomer components constituting the (meth)acrylic polymer (total monomer components). By using the above-described other polymerizable monomer within the above-described range, it is possible to appropriately adjust good interaction with onium salts and the like having a melting point of -4°C or lower and used as antistatic agents and good re-peelability.

The weight average molecular weight (Mw) of the (meth)acrylic polymer is preferably 100,000 to 5 million, more preferably 200,000 to 4 million, further preferably 300,000 to 3 million, most preferably 400,000 to 700,000 . When Mw is less than 100,000, the cohesive force of the resulting adhesive layer decreases, resulting in adhesive residues tending to occur. On the other hand, when the Mw exceeds 5 million, the fluidity of the polymer decreases, and the wetting of the adherend (such as a polarizing film as an optical member, etc.) becomes insufficient, resulting in a gap between the adherend and the surface. There is a tendency for bulging to occur between the adhesive layers (adhesive composition layers) of the protective sheet (adhesive sheet). In addition, Mw means the quantity measured by gel permeation chromatography (GPC).

In addition, the above-mentioned base polymer contains a polymer having a glass transition temperature (Tg) of 0°C or lower (for example, the above-mentioned (meth)acrylic polymer). The Tg of the above-mentioned polymer is preferably -10°C or lower, and more preferably It is -40°C or lower, and more preferably -60°C or lower (usually -100°C or higher). When Tg is higher than 0°C, the polymer becomes difficult to flow. For example, the wetting of the adherend (such as a polarizing film as an optical member) becomes insufficient, resulting in a gap between the adherend and the adhesive layer (adhesion). agent composition layer). In addition, by setting Tg to 0° C. or less, it is easy to obtain an adhesive composition that is excellent in wettability to adherends and light peelability. Furthermore, the Tg of a polymer having a glass transition temperature (Tg) of 0° C. or lower (for example, the (meth)acrylic polymer) can be adjusted to fall within the above range by appropriately changing the monomer components or composition ratio used. .

The polymerization method of the polymer having a glass transition temperature (Tg) of 0° C. or lower (for example, the (meth)acrylic polymer) used in the present invention is not particularly limited, and can be carried out by solution polymerization, emulsion polymerization, bulk polymerization, or suspension polymerization. Polymerization is carried out by known methods such as polymerization, but solution polymerization is a more preferable aspect especially from the viewpoint of workability and properties such as low contamination to adherends. In addition, the obtained polymer may be any one of a random copolymer, a block copolymer, an alternating copolymer, a graft copolymer, and the like.

The adhesive composition of the present invention is characterized in that it contains an onium salt with a melting point of -4°C or lower, and the onium salt is selected from the group consisting of nitrogen-containing onium salts, sulfur-containing onium salts and phosphorus-containing onium salts. Make up at least one of the groups. By using the above-mentioned onium salt with a melting point of -4°C or lower (preferably -10°C or lower, more preferably -70°C or higher and -20°C or lower), the peeling charge suppression effect in a low-temperature environment is improved, which is a preferred aspect. . Furthermore, the onium salt preferably contains an onium cation having at least one alkyl group having at least one carbon number of 8, so that it can have both shearing characteristics and charging characteristics, which is preferred.

The above-mentioned onium salt with a melting point below -4°C is at least one selected from the group consisting of nitrogen-containing onium salts, sulfur-containing onium salts and phosphorus-containing onium salts. The onium salt is a salt composed of a cation component including a nitrogen-containing onium ion, a sulfur-containing onium ion, and a phosphorus-containing onium ion, and an anion component described below.

Examples of the nitrogen-containing onium ion include 1-ethylpyridinium cation, 1-butylpyridinium cation, 1-hexylpyridinium cation, 1-butyl-3-methylpyridinium cation, and 1-butylpyridinium cation. Butyl-4-methylpyridinium cation, 1-hexyl-3-methylpyridinium cation, 1-butyl-3,4-dimethylpyridinium cation, 1,1-dimethylpyrrolidinium cation , 1-ethyl-1-methylpyrrolidinium cation, 1-methyl-1-propylpyrrolidinium cation, 1-methyl-1-butylpyrrolidinium cation, 1-methyl-1- Pentylpyrrolidinium cation, 1-methyl-1-hexylpyrrolidinium cation, 1-methyl-1-heptylpyrrolidinium cation, 1-ethyl-1-propylpyrrolidinium cation, 1- Ethyl-1-butylpyrrolidinium cation, 1-ethyl-1-pentylpyrrolidinium cation, 1-ethyl-1-hexylpyrrolidinium cation, 1-ethyl-1-heptylpyrrolidine onium cation, 1,1-dipropylpyrrolidinium cation, 1-propyl-1-butylpyrrolidinium cation, 1,1-dibutylpyrrolidinium cation, pyrrolidinium-2-one cation, 1-propylpiperidinium cation, 1-pentylpiperidinium cation, 1,1-dimethylpiperidinium cation, 1-methyl-1-ethylpiperidinium cation, 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-pentyl Piperidinium cation, 1-ethyl-1-hexylpiperidinium cation, 1-ethyl-1-heptylpiperidinium cation, 1,1-dipropylpiperidinium cation, 1-propyl-1 -Butylpiperidinium cation, 1,1-dibutylpiperidinium cation, 2-methyl-1-pyrroline cation, 1-ethyl-2-phenylindole cation, 1,2-dimethyl Indole cation, 1-ethylcarbazole cation, N-ethyl-N-methyl linium cation, 1,3-dimethylimidazolium cation, 1,3-diethylimidazolium cation, 1-ethyl-3-methylimidazolium cation, 1-butyl-3-methylimidazolium cation, 1-hexyl-3-methylimidazolium cation, 1-octyl-3-methylimidazolium cation, 1-decyl-3-methylimidazolium cation, 1-dodecyl-3-methyl Imidazolium cation, 1-tetradecyl-3-methylimidazolium cation, 1,2-dimethyl-3-propylimidazolium cation, 1-ethyl-2,3-dimethylimidazolium cation, 1-butyl-2,3-dimethylimidazolium cation, 1-hexyl-2,3-dimethylimidazolium cation, 1-(2-methoxyethyl)-3-methylimidazole onium cation, 1,3-dimethyl-1,4,5,6-tetrahydropyrimidinium cation, 1,2,3-trimethyl-1,4,5,6-tetrahydropyrimidinium cation, 1 ,2,3,4-tetramethyl-1,4,5,6-tetrahydropyrimidinium cation, 1,2,3,5-tetramethyl-1,4,5,6-tetrahydropyrimidinium cation , 1,3-dimethyl-1,4-dihydropyrimidinium cation, 1,3-dimethyl-1,6-dihydropyrimidinium cation, 1,2,3-trimethyl-1,4 -Dihydropyrimidinium cation, 1,2,3-trimethyl-1,6-dihydropyrimidinium cation, 1,2,3,4-tetramethyl-1,4-dihydropyrimidinium cation, 1 ,2,3,4-tetramethyl-1,6-dihydropyrimidinium cation, 1-methylpyrazolium cation, 3-methylpyrazolium cation, 1-ethyl-2-methyldihydrogenation Pyrazolium cation, 1-ethyl-2,3,5-trimethylpyrazolium cation, 1-propyl-2,3,5-trimethylpyrazolium cation, 1-butyl-2, 3,5-trimethylpyrazolium cation, 1-ethyl-2,3,5-trimethyldihydropyrazolium cation, 1-propyl-2,3,5-trimethyldihydropyrazolium cation Azolium cation, 1-butyl-2,3,5-trimethyldihydropyrazolium cation, tetramethylammonium cation, tetraethylammonium cation, tetrabutylammonium cation, tetrapentylammonium cation, tetramethylammonium cation Hexylammonium cation, tetraheptyl ammonium cation, triethylammonium cation, tributylethylammonium cation, trimethyldecylammonium cation, N,N-diethyl-N-methyl-N-( 2-methoxyethyl)ammonium cation, epoxypropyltrimethylammonium cation, diallyldimethylammonium cation, N,N-dimethyl-N-ethyl-N-propylammonium cation , N,N-dimethyl-N-ethyl-N-butylammonium cation, N,N-dimethyl-N-ethyl-N-pentylammonium cation, N,N-dimethyl-N -Ethyl-N-hexylammonium cation, N,N-dimethyl-N-ethyl-N-heptylammonium cation, N,N-dimethyl-N-ethyl-N-nonylammonium cation, N,N-dimethyl-N,N-dipropylammonium cation, N,N-diethyl-N-propyl-N-butylammonium cation, N,N-dimethyl-N-propyl -N-pentylammonium cation, N,N-dimethyl-N-propyl-N-hexylammonium cation, N,N-dimethyl-N-propyl-N-heptyl ammonium cation, N,N -Dimethyl-N-butyl-N-hexylammonium cation, N,N-diethyl-N-butyl-N-heptyl ammonium cation, N,N-dimethyl-N-pentyl-N -Hexylammonium cation, N,N-dimethyl-N,N-dihexylammonium cation, trimethylheptyl ammonium cation, N,N-diethyl-N-methyl-N-propylammonium cation, N,N-diethyl-N-methyl-N-pentylammonium cation, N,N-diethyl-N-methyl-N-heptyl ammonium cation, N,N-diethyl-N- Propyl-N-pentylammonium cation, triethylpropylammonium cation, triethypentylammonium cation, triethyheptylammonium cation, N,N-dipropyl-N-methyl-N-ethyl ammonium cation, N,N-dipropyl-N-methyl-N-pentylammonium cation, N,N-dipropyl-N-butyl-N-hexylammonium cation, N,N-dipropyl -N,N-dihexylammonium cation, N,N-dibutyl-N-methyl-N-pentylammonium cation, N,N-dibutyl-N-methyl-N-hexylammonium cation, tris Octylmethyl ammonium cation, N-methyl-N-ethyl-N-propyl-N-pentylammonium cation, etc.

Examples of the sulfonium-containing ions include diethylmethylsulfonium cation, dibutylethylsulfonium cation, dimethyldecylsulfonium cation, and triethylsulfonium cation.

Examples of the phosphonium-containing ions include trimethyldecylphosphonium cation, triethylmethylphosphonium cation, triethylpentylphosphonium cation, triethyloctylphosphonium cation, and tributylmethylphosphonium cation. Tributylethylphosphonium cation, tributyloctylphosphonium cation, tributyldodecylphosphonium cation, tributyltetradecylphosphonium cation, trihexyltetradecylphosphonium cation, tetrabutylphosphonium cation wait.

On the other hand, the anion component is not particularly limited as long as it is an anion that satisfies the above-mentioned onium salt having a melting point of -4°C or lower. For example, Cl ^- , Br ^- , I ^- , AlCl ₄ ^- , and Al ₂ Cl can be used. ₇ ^- , BF ₄ ^- , PF ₆ ^- , SCN ^- , ClO ₄ ^- , NO ₃ ^- , CH ₃ COO ^- , CF ₃ COO ^- , CH ₃ SO ₃ ^- , CF ₃ SO ₃ ^- , C ₄ F ₉ SO ₃ ^- , (CF ₃ SO ₂ ) ₂ N ^- , (C ₂ F ₅ SO ₂ ) ₂ N ^- , (C ₃ F ₇ SO ₂ ) ₂ N ^- , (C ₄ F ₉ SO ₂ ) ₂ N ^- , (CF ₃ SO ₂ ) ₃ C ^- , AsF ₆ ^- , SbF ₆ ^- , NbF ₆ ^- , TaF ₆ ^- , HF ₂ ^- , (CN) ₂ N ^- , C ₄ F ₉ SO ₃ ^- , (C ₂ F ₅ SO ₂ ) ₂ N ^- , C ₃ F ₇ COO ^- , (CF ₃ SO ₂ )(CF ₃ CO)N ^- , C ₉ H ₁₉ COO ^- , (CH ₃ ) ₂ PO ₄ ^- , (C ₂ H ₅ ) ₂ PO ₄ ^- , C ₂ H ₅ OSO ₃ ^- , C ₆ H ₁₃ OSO ₃ ^- , C ₈ H ₁₇ OSO ₃ ^- , CH ₃ (OC ₂ H ₄ ) ₂ OSO ₃ ^- , C ₆ H ₄ (CH ₃ )SO ₃ ^- , (C ₂ F ₅ ) ₃ PF ₃ ^- , CH ₃ CH(OH)COO ^- and (FSO ₂ ) ₂ N ^- , etc.

In addition, as the anion component, anions represented by the following formula, etc. can also be used. [Chemical 1]

Moreover, as an anionic component, it is particularly preferable to use an anionic component containing a fluorine atom, since an onium salt with a low melting point can be obtained.

Specific examples of the onium salt having a melting point of -4°C or less used in the present invention are appropriately selected from the compositions of the above-mentioned cationic components and anionic components. Examples include 1-butylpyridinium tetrafluoroborate, 1-hexylpyridinium tetrafluoroborate, 1-ethyl-3-methylpyridinium perfluorobutanesulfonate, 1-ethyl-3-methylpyridinium ethyl sulfate, 1-ethyl-3 -Methylpyridinium bis(fluorosulfonyl)imide salt, 1-methyl-1-butylpyrrolidinium bis(trifluoromethanesulfonyl)imide salt, 1-methyl-1-propyl Pyrrolidinium bisfluorosulfonyl imine salt, 1-methyl-1-butylpyrrolidinium bis(trifluoromethanesulfonyl)imide salt, 1-methyl-1-butylpyrrolidinium tris (Pentafluoroethyl)trifluorophosphate, 1-methoxyethyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide, 1-methyl-1-ethylpiperidine Onium bis(trifluoromethanesulfonyl)imide salt, 1-ethyl-3-methylpiperidinium ethyl sulfate, 1-methoxyethyl-1-methylpiperidinium bis(trifluoro Methanesulfonyl)imide salt, 1-methoxyethyl-1-methylpiperidinium tris(pentafluoroethyl)trifluorophosphate, 1-methyl-3-octylimidazolium bromide, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-ethyl-3-methylimidazolium trifluoroacetate, 1-ethyl-3-methylimidazolium bis(fluorosulfonate) base) imine salt, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-ethyl-3-methylimidazolium dicyandiamide, 1-ethyl- 3-methylimidazolium ethyl sulfate, 1-ethyl-3-methylimidazolium octyl sulfate, 1-ethyl-3-methylimidazolium thiocyanate, 1-butyl-3- Methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium trifluoroacetate, 1-butyl-3-methylimidazolium bis(fluorosulfonyl)imide, 1-butyl methyl-3-methylimidazole Tricyanomethane, 1-butyl-3-methylimidazolium dicyandiamide, 1-hexyl-3-methylimidazolium bromide, 1-hexyl-3-methylimidazolium chloride, 1-hexyl- 3-methylimidazolium tetrafluoroborate, 1-hexyl-3-methylimidazolium hexafluorophosphate, 1-hexyl-3-methylimidazolium bis(fluorosulfonyl)imide, 1-hexyl -3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-octyl-3-methylimidazolium chloride, 1-octyl-3-methylimidazolium bromide, 1- Octyl-3-methylimidazolium tetrafluoroborate, 1-octyl-3-methylimidazolium hexafluorophosphate, 1-octyl-3-methylimidazolium bis(trifluoromethanesulfonyl) Imine salt, 1-dodecyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imine salt, 1,3-dimethylimidazolium dimethylphosphate, 1,3-bis Allyl imidazolium bromide, 1,3-diallylimidazolium tetrafluoroborate, 1-allyl-3-butylimidazolium bis(trifluoromethanesulfonyl)imide salt, ethyl Dimethyl-propylammonium bis(trifluoromethanesulfonyl)imide salt, trioctylmethylammonium bis(trifluoromethanesulfonyl)imide salt, 1-methoxyethyl-1-methyl base Physinium ammonium bis(trifluoromethanesulfonyl)imide salt, ethyldimethyl-(2-methoxyethyl)ammonium tris(pentafluoroethyl)trifluorophosphate, triethyloctylphosphonium Bis(trifluoromethanesulfonyl)imine salt, trihexyltetradecylphosphonium bis(trifluoromethanesulfonyl)imine salt, etc.

In addition, the content of the onium salt is preferably 0.1 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, still more preferably 0.2 to 3 parts by mass, based on 100 parts by mass of the base polymer. Preferably it is 0.3 parts by mass to 1.5 parts by mass. Within the above range, it is easy to achieve both antistatic properties and low contamination properties, which is preferable.

The adhesive composition of the present invention preferably contains a compound having an oxidized alkylene group. By using the compound having an oxidized alkylene group, an adhesive composition having excellent wettability to an adherend can be obtained, and the generation of static electricity can be effectively suppressed.

Specific examples of the compound having an oxyalkylene group include polyoxyalkylene alkylamine, polyoxyalkylene diamine, polyoxyalkylene fatty acid ester, and polyoxyalkylene fatty acid ester. Sorbitan fatty acid ester, polyoxyalkylene alkylphenyl ether, polyoxyalkylene alkyl ether, polyoxyalkylene alkyl allyl ether, polyoxyalkylene alkylphenyl ene Nonionic surfactants such as propyl ether; polyoxyalkylene alkyl ether sulfate ester salt, polyoxyalkylene alkylene alkyl ether phosphate ester salt, polyoxyalkylene alkylene phenyl ether sulfate ester salt, polyoxyalkylene alkylene alkyl ether sulfate ester salt, Anionic surfactants such as oxyalkylene alkylene ether phosphate ester salts; and cationic surfactants or amphoteric surfactants with polyoxyalkylene groups (polyoxyalkylene chains), polyoxyalkylene Polyether compounds with alkylene groups (and including derivatives thereof), polyester compounds with polyoxyalkylene groups (and including derivatives thereof), acrylic compounds with polyoxyalkylene groups (and including derivatives thereof) derivatives) etc. Alternatively, a monomer containing an oxidized alkylene group may be used as the compound having an oxidized alkylene group, and may be blended together with the base polymer (for example, the (meth)acrylic polymer). The above-mentioned compounds having an oxidized alkylene group may be used alone or in combination of two or more.

Specific examples of the polyether compound having an oxidized alkylene group include polypropylene glycol (PPG)-polyethylene glycol (PEG) block copolymers, PPG-PEG-PPG block copolymers, PEG-PPG-PEG block copolymer, etc. Examples of derivatives of the polyether compound having an oxyalkylene group include compounds containing an oxypropylene group (PPG monoalkyl ether, PEG-PPG monoalkyl ether, etc.) whose terminals are etherified, terminal Acetylated compounds containing an oxypropylene group (terminal acetylated PPG, etc.), etc.

Specific examples of the acrylic compound having an oxyalkylene group include a (meth)acrylate polymer having an oxyalkylene group. As the above-mentioned oxyalkylene group, from the viewpoint of coordination with the above-mentioned onium salt as an antistatic agent, the molar number of addition of the oxyalkylene unit is preferably 1 to 50, and more preferably 2 to 30. More preferably, it is 2-20. In addition, the terminal of the above-mentioned oxyalkylene group may be a hydroxyl group itself or may be substituted by an alkyl group, a phenyl group, or the like.

The above-mentioned (meth)acrylate polymer having an oxyalkylene group is preferably a polymer containing an oxyalkylene (meth)acrylate as a monomer component (monomer unit). As the above-mentioned oxyalkylene (meth)acrylate Specific examples of esters include ethylene glycol group-containing (meth)acrylates, such as methoxydiethylene glycol (meth)acrylate and methoxytriethylene glycol (meth)acrylate. ) acrylate and other methoxy polyethylene glycol (meth)acrylate types; ethoxy diethylene glycol (meth)acrylate, ethoxy triethylene glycol (meth)acrylate and other ethoxy Polyethylene glycol (meth)acrylate type; butoxydiethylene glycol (meth)acrylate, butoxytriethylene glycol (meth)acrylate and other butoxypolyethylene glycol (meth)acrylate ) Acrylate type; phenoxy polyethylene glycol (meth)acrylate type such as phenoxydiethylene glycol (meth)acrylate and phenoxytriethylene glycol (meth)acrylate; 2- Ethylhexyl polyethylene glycol (meth)acrylate, nonylphenol polyethylene glycol (meth)acrylate type; methoxydipropylene glycol (meth)acrylate and other methoxy polypropylene glycol (meth) Acrylic type etc.

In addition, as the above-mentioned monomer component, other monomer components other than the above-mentioned oxyalkylene (meth)acrylate can be used. Specific examples of other monomer components include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, secondary butyl (meth)acrylate, (meth)acrylate Tertiary butyl acrylate, isobutyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, (meth) Isooctyl acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecane (meth)acrylate Acrylates and/or methacrylates having an alkyl group having 1 to 14 carbon atoms, such as n-tridecyl (meth)acrylate and n-tetradecyl (meth)acrylate.

In addition, as other monomer components other than the above-mentioned oxyalkylene (meth)acrylate, carboxyl group-containing (meth)acrylate, phosphate group-containing (meth)acrylate, cyano group-containing (meth)acrylate, and cyano group-containing (meth)acrylate can be appropriately used. ) Acrylates, vinyl esters, aromatic vinyl compounds, anhydride-containing (meth)acrylates, hydroxyl-containing (meth)acrylates, amide-containing (meth)acrylates, amine-containing (meth)acrylates acrylate, epoxy-containing (meth)acrylate, N-acrylyl Phosphines, vinyl ethers, etc.

As a preferred aspect, the above-mentioned compound having an oxyalkylene oxide group is a compound in which at least part of the compound has a (poly)ethylene oxide group. By blending the above-mentioned compound having a (poly)ethylene oxide group, the compatibility between the base polymer (for example, the above-mentioned (meth)acrylic polymer) and the antistatic agent (antistatic component) is improved, suitably It is possible to obtain a low-contamination adhesive composition by suppressing leakage to the adherend. Among them, especially when a PPG-PEG-PPG block copolymer is used, an adhesive composition excellent in low contamination properties can be obtained. As the above-mentioned compound containing a (poly)ethylene oxide group, it is preferable that the (poly)ethylene oxide group accounts for 5 to 90 mass % of the mass of the entire compound, and more preferably 5 mass% to 85 mass%, more preferably 10 mass% to 70 mass%, most preferably 20 mass% to 50 mass%.

As for the molecular weight of the compound having an oxidized alkylene group, the number average molecular weight (Mn) is preferably less than 100,000, more preferably 200 to 50,000, still more preferably 500 to 30,000, and particularly preferably the number average molecular weight (Mn) is 1,000. ~10,000 for compounds with oxidized alkylene groups. When Mn is 100,000 or more, the compatibility with the base polymer (for example, the above-mentioned (meth)acrylic polymer) decreases, and the adhesive layer tends to whiten. If Mn is too small compared to 200, contamination caused by the compound having an oxidized alkylene group may easily occur. Here, Mn refers to a polystyrene-equivalent value obtained by gel permeation chromatography (GPC).

Specific examples of commercially available compounds having an oxidized alkylene group include ADEKA Pluronic 17R-4, ADEKA Pluronic 25R-1, ADEKA Pluronic 25R-2 (manufactured by ADEKA Corporation), EMULGEN 120 ( The above are manufactured by Kao Corporation), etc.

In the present invention, it is preferable that the compound having an oxidized alkylene group is an organopolysiloxane having an oxidized alkylene group. It is presumed that by using the above-mentioned organopolysiloxane, the surface free energy of the adhesive surface is reduced, thereby achieving light peeling during high-speed peeling.

As the above-mentioned organopolysiloxane, a known organopolysiloxane having an oxyalkylene group can be appropriately used. For example, commercially available products include trade names X-22-4952, X-22-4272, and X-22. -6266, KF-6004, KF-889, 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, 201, SF8427, 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 (the above are manufactured by Toray Dow Corning Co., Ltd.), IM22 (the above are manufactured by Asahi Kasei Wacker Co., Ltd.), TSF-4440, TSF-4441, TSF-4445, TSF-4450, TSF-4446, TSF-4452, TSF-4460 (the above is manufactured by Momentive Performance Materials), BYK-333, BYK-307, BYK-377, BYK-UV3500, BYK-UV3570 (the above is BYK-CHEMIE JAPAN ) manufactured by the company) etc. These compounds may be used individually or in mixture of two or more types.

The above-mentioned organopolysiloxane used in the present invention preferably has an HLB (Hydrophile-Lipophile Balance) value of 1 to 16, and more preferably 3 to 14. If the HLB value deviates from the above range, the contamination of the adherend will worsen, which is not preferable.

In addition, the content of the compound having an oxidized alkylene group is preferably 0.01 to 5 parts by mass, more preferably 0.03 to 3 parts by mass, and even more preferably 0.05 parts by mass relative to 100 parts by mass of the base polymer. ~2 parts by mass, and most preferably 0.1 part by mass to 1 part by mass. When it is within the above range, it is easy to have both antistatic properties and light peeling properties (repeelability), which is preferable. In addition, when the content is small, the effect of preventing the antistatic agent (antistatic component) from oozing out is reduced, and when the content is large, it may become easy to cause problems caused by the compound having an oxidized alkylene group itself. Contamination, so not preferred.

The adhesive composition of the present invention may contain a fluorinated oligomer with a weight average molecular weight (Mw) of 3,500 or more. By using the above-mentioned fluorine-containing oligomer, the chargeability of the adhesive itself can be controlled, and it can be stabilized even when applied to optical members that have been subjected to various surface treatments (hard coating treatment, anti-glare treatment, low-reflection treatment, etc.) Effectively suppress the generation of static electricity.

Examples of the fluorine-containing compound include compounds having a fluorine-containing aliphatic hydrocarbon skeleton, fluorine-containing organic compounds obtained by copolymerizing organic compounds and fluorine compounds, fluorine-containing compounds containing organic compounds, and the like. Specific examples of the above-mentioned fluorine-containing oligomers include, for example, the trade names of commercially available products: Megafac F-251, F-253, F-281, F-410, F-430, F-444, and F-477. , F-510, F-511, F-551, F-552, F-553, F-554, F-555, F-556, F-557, F-558, F-559, F-560, F -561, F-562, F-563, F-565, F-568, F-569, F-570, F-571, F-572 (the above are manufactured by DIC Company), Surflon S-611, S-651 , S-386 (the above are manufactured by AGC SEIMI CHEMICAL), FTERGENT 610FM, 710FL, 710FM, 710FS, 730FL, 730LM (the above are manufactured by NEOS), etc. These compounds may be used individually or in mixture of two or more types.

The weight average molecular weight (Mw) of the above-mentioned fluorine-containing oligomer is preferably 3,500 or more, more preferably 5,000 or more, further preferably 10,000 or more, and most preferably 20,000 or more. When the weight average molecular weight of the above-mentioned fluorinated oligomer is 3,500 or more, the compatibility with the adhesive can be balanced, and the fluorine-containing oligomer can be moderately segregated on the surface of the adhesive. Furthermore, when the weight average molecular weight is 20,000 or more, foaming during blending of the adhesive can be suppressed, and the appearance after application of the adhesive is excellent, which is preferable.

The content of the fluorinated oligomer is preferably 0.01 to 10 parts by mass, more preferably 0.02 to 7.5 parts by mass, and even more preferably 0.03 to 5.5 parts by mass relative to 100 parts by mass of the base polymer. Most preferably, it is 0.04 parts by mass to 4.8 parts by mass. Within the above range, it is possible to suppress peeling charge after laminating the surface protection sheet of the present invention to an optical member or the like, which is preferable. In addition, in order to satisfy contamination resistance, the content is preferably 0.01 to 5.5 parts by mass relative to 100 parts by mass of the base polymer.

The adhesive composition of the present invention preferably contains a cross-linking agent. Furthermore, in the present invention, the adhesive layer can be formed by blending a cross-linking agent into the above-mentioned adhesive composition. For example, when the above-mentioned adhesive contains the above-mentioned (meth)acrylic polymer, the above-mentioned (meth)acrylic polymer can be prepared by appropriately adjusting the structural units, structural ratio, selection and addition ratio of the cross-linking agent, etc. By cross-linking, a surface protection sheet (adhesive layer) with better heat resistance can be obtained.

As the crosslinking agent used in the present invention, isocyanate compounds, epoxy compounds, melamine-based resins, aziridine derivatives, metal chelate compounds, etc. can be used, and an isocyanate compound is particularly preferred. In addition, these compounds may be used individually or in mixture of 2 or more types.

Examples of the isocyanate compound include aliphatic polyisocyanates such as trimethylene diisocyanate, butylene diisocyanate, hexamethylene diisocyanate (HDI), and dimer diisocyanate; cyclopentyl diisocyanate; Alicyclic isocyanates such as isocyanate, cyclohexyl diisocyanate, isophorone diisocyanate (IPDI); 2,4-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate (XDI) and other aromatic isocyanates, utilizing allophanate bonds, biuret bonds, isocyanurate bonds, uretdione bonds, urea bonds, carbodiimide bonds, uretonimine bonds, two A polyisocyanate modified product obtained by modifying the above-mentioned isocyanate compound such as a triketone bond or the like. For example, commercially available products include products under the trade names Takenate 300S, Takenate 500, Takenate D165N, Takenate D178N (the above are manufactured by Mitsui Chemicals Co., Ltd.), Sumidule T80, Sumidule L, and Desmodur N3400 (the above are Sumika Bayer Urethane). ), Millionate MR, Millionate MT, Coronate L, Coronate HL, Coronate HX (the above are manufactured by Tosoh Corporation), etc. These isocyanate compounds may be used alone or in combination of two or more types. A bifunctional isocyanate compound and a trifunctional or higher functional isocyanate compound may be used in combination. By using a cross-linking agent in combination, it is possible to obtain both adhesiveness and resilience resistance (adhesion to curved surfaces), thereby obtaining a surface protection sheet with better adhesion reliability.

Examples of the epoxy compound include N,N,N',N'-tetraepoxypropyl metaxylylenediamine (trade name TETRAD-X, manufactured by Mitsubishi Gas Chemical Co., Ltd.), 1,3-bis (N,N-Diepoxypropylaminomethyl)cyclohexane (trade name TETRAD-C, manufactured by Mitsubishi Gas Chemical Co., Ltd.) and the like.

Examples of the melamine-based resin include hexamethylolmelamine and the like. Examples of the aziridine derivatives include those commercially available under the trade names HDU, TAZM, and TAZO (the above are manufactured by Soho Pharmaceutical Co., Ltd.).

As the metal chelate compound, examples of metal components include aluminum, iron, tin, titanium, nickel, etc., and examples of chelate components include acetylene, methyl acetyl acetate, 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, and more preferably 0.1 to 100 parts by mass relative to 100 parts by mass of the (meth)acrylic polymer as the base polymer. 8 parts by mass, more preferably 0.5 to 5 parts by mass, and most preferably 1 to 4 parts by mass. When the above content is less than 0.01 parts by mass, crosslinking by the crosslinking agent is insufficient, the cohesive force of the resulting adhesive layer becomes small, sufficient heat resistance may not be obtained, and there is a risk of causing glue residue. tendency. On the other hand, when the content exceeds 10 parts by mass, the cohesion of the polymer increases, the fluidity decreases, and the wetting of the adherend (such as polarizing film) becomes insufficient, resulting in a gap between the adherend and the adhesive. There is a tendency for bulges to occur between the adhesive layers (adhesive composition layers). In addition, when the amount of crosslinking is large, the peeling charging characteristics tend to decrease.

In order to carry out any of the above cross-linking reactions more effectively, the above-mentioned adhesive composition may further contain a cross-linking catalyst. As the cross-linking catalyst, tin-based catalysts such as dibutyltin dilaurate and dioctyltin dilaurate can be used; tris(acetylacetonate)iron, tris(hexane-2,4-diketonate) Iron, tri(heptane-2,4-diketonate)iron, tri(heptane-3,5-diketonate)iron, tri(5-methylhexane-2,4-diketonate)iron , Tris(octane-2,4-dione)iron, Tris(6-methylheptane-2,4-dionate)iron, Tris(2,6-dimethylheptane-3,5 -Diketonate)iron, tris(nonane-2,4-diketonate)iron, tris(nonane-4,6-diketonate)iron, tris(2,2,6,6-tetramethyl) Heptane-3,5-dionate)iron, tris(tridecane-6,8-dionate)iron, tris(1-phenylbutane-1,3-dionate)iron, tris( Hexafluoroacetyl acetonate) iron, tris (acetyl ethyl acetate) iron, tris (acetyl n-propyl acetate) iron, tris (acetyl acetate isopropyl acetate) iron, tris (acetyl n-butyl acetate) Iron, tri(acetyl acetate ethyl acetate) iron, tri(acetyl acetate tertiary butyl acetate) iron, tri(propyl ethyl acetate) iron, tri(propyl ethyl acetate) iron, tri(propyl ethyl acetate) n-propyl acetate) iron, tris(propyl propyl acetate isopropyl acetate) iron, tris(propyl n-butyl acetate) iron, tris(propyl acetate secondary butyl acetate) iron, tris(propyl acetate tri-butyl acetate) grade butyl ester) iron, tri(benzyl acetate) iron, tri(dimethyl malonate) iron, tri(diethyl malonate) iron, trimethoxy iron, triethoxy iron, tri Iron catalysts such as iron isopropoxide and ferric chloride. These crosslinking catalysts may be used alone or in combination of two or more types.

The content of the crosslinking catalyst is not particularly limited. For example, it is preferably approximately 0.0001 to 1 part by mass, and more preferably 0.001 to 0.5 parts by mass relative to 100 parts by mass of the (meth)acrylic polymer as the base polymer. parts by mass. When it is within the above range, the speed of the cross-linking reaction when forming the adhesive layer is fast, and the pot life of the adhesive composition is also prolonged, which is a preferred aspect.

In addition, the adhesive composition of the present invention may contain other well-known additives. For example, powders such as colorants and pigments, surfactants, plasticizers, tackifiers, and low molecular weight polymers may be appropriately added according to the intended use. , surface lubricants, leveling agents, antioxidants, corrosion inhibitors, light stabilizers, UV absorbers, polymerization inhibitors, silane coupling agents, cross-linking retarder, inorganic or organic fillers, metal powder, granular, foil, etc.

The surface protection sheet of the present invention preferably has an adhesive layer formed of the above-mentioned adhesive composition (formed by cross-linking the adhesive composition) on one side of the support film. The crosslinking of the adhesive composition is usually performed after coating of the adhesive composition. However, the adhesive layer containing the crosslinked adhesive composition may also be transferred to a support film or the like. In addition, the method of forming the adhesive layer on the above-mentioned support film is not particularly limited. For example, it can be produced by applying the above-mentioned adhesive composition on the support film and drying to remove the polymerization solvent, thereby forming an adhesive layer on the support film. Adhesive layer. Then, aging can be performed for the purpose of adjusting the component transfer of the adhesive layer, adjusting the cross-linking reaction, and the like. In addition, when the adhesive composition is applied to a support film to produce a surface protection sheet, one or more solvents other than the polymerization solvent may be newly added to the adhesive composition in order to apply the adhesive composition uniformly to the support film.

<Support Film> As the above-mentioned support film, the resin material constituting the above-mentioned support film can be used without particular limitation. For example, transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, flexibility, and dimensional stability are preferably used. Materials with excellent properties. In particular, it is useful that the support film has flexibility so that the adhesive composition can be applied using a roll coater or the like and can be wound into a roll.

As the support film (base material), for example, polyesters made of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate, etc. can be preferably used. Polymers; cellulose polymers such as diacetyl cellulose and triacetyl cellulose; polycarbonate polymers; acrylic polymers such as polymethyl methacrylate; etc. as the main resin component (in the resin component A plastic film composed of a resin material as the main component (typically a component accounting for more than 50% by mass) is used as the above-mentioned support film. Other examples of the above-mentioned resin material include styrenic polymers such as polystyrene and acrylonitrile-styrene copolymer; polyethylene, polypropylene, cyclic or reduced polymers; Olefin polymers such as ethylene-structured polyolefins and ethylene-propylene copolymers; vinyl chloride polymers; amide polymers such as nylon 6, nylon 6,6, aromatic polyamides; etc. as support films for resin materials . Other examples of the above-mentioned resin material include amide-based polymers, polyester-based polymers, polyether-based polymers, polyetheretherketone-based polymers, polyphenylene sulfide-based polymers, and vinyl alcohol-based polymers. Polymers, vinylidene chloride polymers, vinyl butyral polymers, aryl ester polymers, polyoxymethylene polymers, epoxy polymers, etc. It may also be a support film containing a blend of two or more of the above-mentioned polymers.

As the support film, a plastic film made of a transparent thermoplastic resin material can be preferably used. Among the above-mentioned plastic films, a polyester film is more preferably used. Here, polyester film refers to a polymer made of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate, etc. and has a main skeleton based on ester bonds. A film made of polyester resin as the main resin component. The polyester film has characteristics suitable as a support film for an adhesive sheet, such as excellent optical properties and dimensional stability. On the other hand, it itself has the property of being easily charged.

The resin material constituting the support film may be blended with various additives such as antioxidants, ultraviolet absorbers, plasticizers, colorants (pigments, dyes, etc.) as necessary. The surface of the polyester film on the side where the antistatic layer is provided can be subjected to known or conventional methods such as corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, coating of primer, etc. handle. Such surface treatment may be, for example, a treatment for improving the adhesion between the support film and the antistatic layer. Surface treatment in which polar groups such as hydroxyl groups are introduced onto the surface of the supporting film can be preferably used. In addition, the same surface treatment as described above may be performed on the surface of the support film on the side where the adhesive layer is formed. The surface treatment may be a treatment for improving the adhesion between the film and the adhesive layer (anchoring of the adhesive layer).

In addition, the surface protection sheet of the present invention may also provide a support film with an antistatic function. If it has an antistatic function, further, a plastic film that has been subjected to an antistatic treatment may be used as the support film. By using the above-mentioned support film, charging of the surface protection sheet itself during peeling is suppressed, which is preferable. In addition, the support film is a plastic film. By subjecting the plastic film to antistatic treatment, the surface protection sheet itself can be less charged and can obtain a surface protection sheet with excellent antistatic ability to adherends. Furthermore, there is no particular limitation on the method for imparting antistatic function, and conventionally known methods can be used. For example, coating of an antistatic resin or conductive polymer composed of an antistatic agent and a resin component, Methods of making conductive resins into conductive substances; methods of evaporating or plating conductive substances; and methods of kneading antistatic agents, etc.; etc.

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

In addition, as the formation method of the adhesive layer when manufacturing the surface protection sheet of this invention, a well-known method used for manufacturing adhesive sheets is used. Specific examples include roll coating, gravure coating, reverse coating, roller brushing, spray coating, air knife coating, extrusion coating using a die coater, and the like.

The surface protection sheet of the present invention is usually produced in such a manner that the thickness of the adhesive layer is preferably about 3 μm to 100 μm, more preferably about 5 μm to 50 μm. When the thickness of the adhesive layer is within the above range, it is easy to obtain a moderate balance of removability and adhesiveness (adhesion), which is preferable.

<Separator> On the surface protection sheet of the present invention, a separator can be attached to the surface of the adhesive layer for the purpose of protecting the adhesive surface as needed.

Examples of materials constituting the separator include paper and plastic films. From the viewpoint of excellent surface smoothness, plastic films are preferably used. The film is not particularly limited as long as it can protect the adhesive layer. Examples thereof include polyethylene film, polypropylene film, polybutylene film, polybutadiene film, and polymethylpentene. Film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, ethylene-vinyl acetate copolymer film, etc.

The thickness of the separator is usually about 5 μm to 200 μm, preferably about 10 μm to 100 μm. Within the above range, it is preferable because the workability of laminating to the adhesive layer and the workability of peeling from the adhesive layer are excellent. The above-mentioned separation parts can also be subjected to release and antifouling treatment using polysiloxane, fluorine-containing, long-chain alkyl or fatty acid amide release agents, silica powder, etc. as needed, or Anti-static treatment for coating type, kneading type, evaporation type, etc.

<Antistatic Layer> The surface protection sheet of the present invention preferably has an antistatic layer on the side opposite to the adhesive layer to be formed on the support film, and the antistatic layer is made of polyaniline and/or polyethylene. Thiophenes are formed as an antistatic agent composition as a conductive polymer component. By having the above-mentioned surface protection sheet with an anti-static layer, it is possible to reduce the charge of the surface protection sheet itself and obtain a surface protection sheet with excellent anti-static properties for adherends, which is a preferred aspect.

<Conductive Polymer> The antistatic agent composition used for forming the antistatic layer preferably contains polyanilines and/or polythiophenes as a conductive polymer component. By using the conductive polymer described above, antistatic properties in low-temperature environments can be satisfied.

Examples of the polyanilines include polyaniline, poly(2-methylaniline), poly(3-isobutylaniline), poly(2-anilinesulfonic acid), and poly(3-anilinesulfonic acid).

The polyanilines preferably have a polystyrene-reduced weight average molecular weight (Mw) of 5×10 ⁵ or less, more preferably 3×10 ⁵ or less. In addition, the weight average molecular weight of these conductive polymers is generally preferably 1×10 ³ or more, and more preferably 5×10 ³ or more.

Among the above-mentioned polyanilines, examples of commercially available products of the above-mentioned polyaniline sulfonic acid include the trade name "aqua-PASS" manufactured by Mitsubishi Rayon Co., Ltd. and the like.

Examples of the polythiophenes include polythiophene, poly(3-methylthiophene), poly(3-ethylthiophene), poly(3-propylthiophene), and poly(3-butylthiophene). , poly(3-hexylthiophene), poly(3-heptylthiophene), poly(3-octylthiophene), poly(3-decylthiophene), poly(3-dodecylthiophene), poly(3 -octadecylthiophene), poly(3-bromothiophene), poly(3-chlorothiophene), poly(3-iodothiophene), poly(3-cyanothiophene), poly(3-phenylthiophene), Poly(3,4-dimethylthiophene), poly(3,4-dibutylthiophene), poly(3-hydroxythiophene), poly(3-methoxythiophene), poly(3-ethoxythiophene) ), poly(3-butoxythiophene), poly(3-hexyloxythiophene), poly(3-heptoxythiophene), poly(3-octoxythiophene), poly(3-decyloxythiophene) ), poly(3-dodecyloxythiophene), poly(3-octadecyloxythiophene), poly(3,4-dihydroxythiophene), poly(3,4-dimethoxythiophene), Poly(3,4-diethoxythiophene), poly(3,4-dipropoxythiophene), poly(3,4-dibutoxythiophene), poly(3,4-dihexyloxythiophene) ), poly(3,4-diheptoxythiophene), poly(3,4-dioctyloxythiophene), poly(3,4-didecoxythiophene), poly(3,4-bis(dec dialkoxy)thiophene), poly(3,4-ethylenedioxythiophene), poly(3,4-propylenedioxythiophene), poly(3,4-butylenedioxythiophene) Thiophene), poly(3-methyl-4-methoxythiophene), poly(3-methyl-4-ethoxythiophene), poly(3-carboxythiophene), poly(3-methyl-4- Carboxythiophene), poly(3-methyl-4-carboxyethylthiophene), poly(3-methyl-4-carboxybutylthiophene). Among them, poly(3,4-ethylenedioxythiophene) is preferred from the viewpoint of electrical conductivity.

The polythiophenes preferably have a polystyrene-reduced weight average molecular weight (Mw) of 4×10 ⁵ or less, and more preferably 3×10 ⁵ or less. In addition, the Mw of polythiophenes is generally preferably 1×10 ³ or more, and more preferably 5×10 ³ or more.

For the above-mentioned polythiophenes, polythiophenes doped with polyanions can also be used.

The polyanionics are polymers having a structural unit having an anionic group, and function as a dopant for polythiophenes. Examples of the polyanions include polystyrene sulfonic acid, polyvinyl sulfonic acid, polyallylsulfonic acid, polyacrylyl sulfonic acid, polymethacrylyl sulfonic acid, and poly(2- Acrylamide-2-methylpropanesulfonic acid), polyisoprene sulfonic acid, polysulfoethyl methacrylate, poly(4-sulfobutyl methacrylate), polymethallyl Oxybenzene sulfonic acid, polyvinyl carboxylic acid, polystyrene carboxylic acid, polyallyl carboxylic acid, polyacrylamide carboxylic acid, polymethacrylamide carboxylic acid, poly(2-acrylamide- 2-Methylpropanecarboxylic acid), polyisoprenecarboxylic acid, polyacrylic acid, polysulfonated phenylacetylene, etc. They may be homopolymers or copolymers of two or more types. Among them, polystyrene sulfonic acid is preferred.

The weight average molecular weight (Mw) of the polyanions is preferably 1,000 to 1,000,000, more preferably 2,000 to 500,000. When Mw is within the above range, it is preferable because it has excellent doping properties and dispersibility in polythiophenes.

As a commercially available product of polythiophenes doped with the above polyanions, for example, Bayer's poly(3,4-ethylenedioxythiophene)/polystyrenesulfonic acid (PEDOT/PSS) can be exemplified. The brand name "Bytron P" manufactured by the company, the brand name "SEPLEGYDA" manufactured by Shin-Etsu Polymer Co., Ltd., the brand name "VERAZOL" manufactured by Soken Chemical Co., Ltd., etc.

<Binder> In order to provide mechanical strength and thermal stability, the antistatic agent composition used for forming the antistatic layer preferably contains a binder component. Examples of the binder component include acrylic resins, polysiloxane resins, fluororesins, styrene resins, polyester resins, alkyd resins, polyurethane resins, amide resins, polyolefin resins, and modified or modified versions thereof. copolymer resin. In addition, the above-mentioned resins can be used alone or in combination of two or more types. Among the above-mentioned resins, polyester resin is preferably used especially from the viewpoint of balancing mechanical strength and charging characteristics.

The polyester resin is preferably a resin material containing 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 polyesters selected from polycarboxylic acids having two or more carboxyl groups in one molecule (typically dicarboxylic acids) and their derivatives (anhydrides, esters, halides, etc. of the polycarboxylic acids). One or two or more compounds (polycarboxylic acid components) and one or two or more compounds (polyol components) selected from polyols (typically glycols) having two or more hydroxyl groups in one molecule ) structure obtained by condensation.

Examples of compounds that can be used as the polycarboxylic acid component include oxalic acid, malonic acid, difluoromalonic acid, alkylmalonic acid, succinic acid, tetrafluorosuccinic acid, and alkylsuccinic acid. (±)-Malic acid, meso-tartaric acid, itaconic acid, maleic acid, methylmaleic acid, fumaric acid, methylfumaric acid, acetylenic acid, glutaric acid, hexafluoroglutaric acid, Methylglutaric acid, glutenedic acid, adipic acid, dithioadipic acid, methyladipic acid, dimethyladipic acid, tetramethyladipic acid, methyleneadipic acid, mucilage Conic acid, galactocarboxylic acid, pimelic acid, suberic acid, perfluorosuberic acid, 3,3,6,6-tetramethylsuberic acid, azelaic acid, sebacic acid, perfluorosebacic acid , brazilic acid, dodecyldicarboxylic acid, tridecyldicarboxylic acid, tetradecyldicarboxylic acid and other aliphatic dicarboxylic acids; cycloalkyldicarboxylic acid (for example, 1,4-cyclohexanedicarboxylic acid , 1,2-cyclohexanedicarboxylic acid), 1,4-(2-chloro En) dicarboxylic acid, 5-nor Alicyclic dicarboxylic acids such as ene-2,3-dicarboxylic acid (nadic acid), adamantanedicarboxylic acid, and spiroheptanedicarboxylic acid; phthalic acid, isophthalic acid, and dithioisophthalic acid , methylisophthalic acid, dimethylisophthalic acid, chloroisophthalic acid, dichloroisophthalic acid, terephthalic acid, methylterephthalic acid, dimethylterephthalic acid , Chlorinated terephthalic acid, bromoterephthalic acid, naphthalenedicarboxylic acid, oxofluorenedicarboxylic acid, anthracenedicarboxylic acid, biphenyldicarboxylic acid, diphenyldicarboxylic acid, dimethyl diphenyldicarboxylic acid, 4 ,4”-p-triphenylenedicarboxylic acid, 4,4”-p-tetraphenylenedicarboxylic acid, bibenzyldicarboxylic acid, azophthalic acid, homophthalic acid, phenylene diacetic acid, phenylene dicarboxylic acid Propionic acid, naphthalenedicarboxylic acid, naphthalenedicarboxylic acid, biphenyl diacetic acid, biphenyl dipropionic acid, 3,3'-[4,4'-(methylene di-p-biphenyl) dipropionic acid, 4, Aromatic dicarboxylic acids such as 4'-bibenzyldiacetic acid, 3,3'-(4,4'-bibenzyl)dipropionic acid, and oxydi-p-phenylenediacetic acid; any of the above polycarboxylic acids Anhydrides; esters of any of the above-mentioned polycarboxylic acids (such as alkyl esters. It can be monoesters, diesters, etc.); acyl halides corresponding to any of the above-mentioned polycarboxylic acids (such as dimethyl chloride); etc.

Preferable examples of compounds that can be used as the polycarboxylic acid component include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalene dicarboxylic acid, and their acid anhydrides; adipic acid, and sebacic acid. azelaic acid, succinic acid, fumaric acid, maleic acid, nadic acid, 1,4-cyclohexanedicarboxylic acid and other aliphatic dicarboxylic acids and their anhydrides; and lower alkanes of the above dicarboxylic acids ester (for example, an ester with a monohydric alcohol having 1 to 3 carbon atoms), etc.

On the other hand, examples of compounds that can be used as the polyol component include ethylene glycol, propylene glycol, 1,2-propanediol, 1,3-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, 2,2-diethyl-1,3-propanediol, 2-butyl-2-ethyl-1, 3-Propylene glycol, benzenedimethanol, hydrogenated bisphenol A, bisphenol A and other glycols. Other examples include alkylene oxide adducts of these compounds (for example, ethylene oxide adducts, propylene oxide adducts, etc.).

The molecular weight of the polyester resin may be, for example, about 5×10 ³ to 1.5×10 ⁵ (preferably 1×10 4 ) based on a standard polystyrene-reduced weight average molecular weight (Mw) measured by gel permeation chromatography ( ^GPC) . ~6×10 ⁴ or so). In addition, the glass transition temperature (Tg) of the polyester resin may be, for example, 0°C to 120°C (preferably 10°C to 80°C).

As the polyester resin, commercially available products such as "VYLONAL MD-1480" manufactured by Toyobo Co., Ltd. can be used.

The antistatic agent composition used in the formation of the above-mentioned antistatic layer may further contain resins other than polyester resin ( For example, one or two selected from acrylic resin, acrylic polyurethane resin, acrylic styrene resin, acrylic polysiloxane resin, polysiloxane resin, polysilazane resin, polyurethane resin, fluorine resin, polyolefin resin, etc. More than one type of resin) as a binder. A preferred aspect of the technology disclosed here is a case where the binder contained in the antistatic agent composition substantially only contains polyester resin. For example, an antistatic layer (antistatic agent composition) in which the proportion of polyester resin in the binder is preferably 98% by mass to 100% by mass. The proportion of the binder in the entire antistatic layer can be set to, for example, 50% by mass to 95% by mass, and is usually appropriately set to 60% by mass to 90% by mass.

The content of the conductive polymer is preferably 10 to 200 parts by mass, more preferably 25 to 150 parts by mass relative to 100 parts by mass of the binder contained in the antistatic agent composition used to form the antistatic layer. parts, more preferably 40 parts by mass to 120 parts by mass. If the content of the conductive polymer is too small, the antistatic effect may be reduced. If the content of the conductive polymer is too much, the adhesion of the antistatic layer to the supporting film may be reduced or the transparency may be reduced, which is not preferable.

The antistatic agent composition used in the formation of the antistatic layer disclosed here may contain polyanilines and/or polythiophenes as conductive polymer components, but may also contain one or two or more other types together. Antistatic components (organic conductive substances other than conductive polymers, inorganic conductive substances, antistatic agents, etc.).

Examples of the organic conductive substance include quaternary ammonium salts, pyridinium salts, cationic antistatic agents having cationic functional groups such as primary amine groups, secondary amine groups, and tertiary amine groups; sulfonates, sulfuric acid Anionic antistatic agents with anionic functional groups such as ester salts, phosphonates, and phosphate ester salts; amphoteric antistatic agents such as alkyl betaine and its derivatives, imidazoline and its derivatives, alanine and its derivatives, etc. Agents; non-ionic antistatic agents such as amino alcohols and their derivatives, glycerol and its derivatives, polyethylene glycol and its derivatives; the ion conductive groups having the above-mentioned cationic, anionic and zwitterionic types Ion conductive polymers obtained by polymerization or copolymerization of monomers (such as quaternary ammonium salt groups); conductive polymers such as polythiophene, polyaniline, polypyrrole, polyethyleneimine, and allylamine polymers polymer. One type of such antistatic agent may be used alone, or two or more types 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, and iron. , cobalt, copper iodide, ITO (indium oxide/tin oxide), ATO (antimony oxide/tin oxide), etc. One type of such inorganic conductive material may be used alone, or two or more types may be used in combination.

Examples of the antistatic agent include cationic antistatic agents, anionic antistatic agents, amphoteric antistatic agents, nonionic antistatic agents, and ions having the above cationic, anionic, and zwitterionic types. Ion conductive polymers obtained by polymerizing or copolymerizing monomers of conductive groups, etc.

<Lubricant> A preferred aspect of the antistatic agent composition used in the formation of the antistatic layer disclosed here is to use one selected from the group consisting of fatty acid amide, polysiloxane lubricant, fluorine-containing lubricant, and At least one of the group consisting of wax lubricants serves as the lubricant. By using at least one selected from the group consisting of fatty acid amide, polysiloxane lubricant, fluorine-containing lubricant, and wax lubricant as a lubricant, even if the antistatic layer is not applied to the surface In the aspect of further peeling treatment (for example, a treatment in which a well-known peeling treatment agent such as a polysiloxane-based release agent or a long-chain alkyl-based release agent is applied and dried), it is possible to obtain both sufficient lubricity and printing. Adhesive anti-static layer, so it can be used as a preferred aspect. In this aspect, the surface of the antistatic layer is not subjected to further peeling treatment because whitening caused by the peeling treatment agent (for example, whitening caused by storage under heating and humidification conditions) can be prevented in advance. Look is preferred. In addition, it is also advantageous from the viewpoint of solvent resistance.

Furthermore, as the lubricant, fatty acid amide is particularly preferably used. By using fatty acid amide as a lubricant, it is easy to achieve both lubricity and printing adhesion on the surface of the antistatic layer, and an excellent antistatic layer can be obtained, so this is a preferred aspect.

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, and erucic acid amide amide, N-oleyl palmitamide, N-stearyl stearyl amide, N-stearyl oleyl amide, N-oleyl stearyl amide, N-stearyl amide Erucamide, hydroxymethyl stearamide, methylene distearamide, ethyl bisdecanoic acid amide, ethyl bislauric acid amide, ethyl bis stearic acid amide Amine, ethylidenebishydroxystearamide, ethylidenebisbehenamide, hexamethylenebisstearamide, hexamethylenebisbehenamide, hexamethylenehydroxy Stearic acid amide, N,N'-distearyl adipamide, N,N'-distearyl sebacate amide, ethyl dioleic acid amide, ethyl bismustard Acid amide, hexamethylene bis-oleic acid amide, N,N'-dioleyl adipamide, N,N'-dioleyl sebacate amide, isophthalimethylene Distearamide, isophthalimethylene bishydroxystearamide, N,N'-stearylisophthalamide, etc. These lubricants may be used alone or in combination of two or more.

The proportion of the lubricant in the entire antistatic layer can be set to 1 mass % to 50 mass %, and is usually appropriately set to 5 mass % to 40 mass %. When the content ratio of the lubricant is too small, the lubricity tends to decrease easily. If the lubricant content is too high, the printing adhesion may be reduced.

The technology disclosed here can be implemented in such a manner that the antistatic agent composition used for forming the antistatic layer contains other lubricants in addition to the above-mentioned fatty acid amide, as long as the application effect is not greatly impaired. . Examples of the other lubricants include petroleum waxes (paraffin wax, etc.), mineral waxes (montan wax, etc.), higher fatty acids (ceric acid, etc.), neutral fats (glyceryl tripalmitate, etc.), and the like. wax. Alternatively, in addition to the above-mentioned wax, a general polysiloxane lubricant, a fluorine-containing lubricant, etc. may be additionally contained. The technology disclosed here can preferably be implemented in an aspect that does not substantially contain the polysiloxane lubricant, fluorine-containing lubricant, or the like. However, it does not exclude the inclusion of a defoaming agent for a purpose different from that of a lubricant (for example, as a coating material for forming an antistatic layer described later) within the limit that does not significantly impair the application effect of the technology disclosed here. ) and polysiloxane compounds used.

<Crosslinking Agent> A preferred aspect of the antistatic agent composition used in forming the antistatic layer is to use an agent selected from the group consisting of a silane coupling agent, an epoxy crosslinking agent, a melamine crosslinking agent, and an isocyanate crosslinking agent. combination agent, At least one of the group consisting of oxazoline cross-linking agents, carbodiimide cross-linking agents and organometallic cross-linking agents is used as the cross-linking agent. Among them, in particular, by using the above-mentioned melamine-based cross-linking agent or the above-mentioned isocyanate-based cross-linking agent, polyanilines and polythiophenes, which are conductive polymer components used when forming the antistatic layer, can be fixed in the adhesive. It has excellent water resistance and solvent resistance, which can improve printing adhesion and other effects. In particular, water resistance and solvent resistance are improved by using a melamine-based cross-linking agent, water resistance and printing adhesion are improved by using an isocyanate-based cross-linking agent, and water resistance, solvent resistance, and printing adhesion are improved by using these cross-linking agents in combination. Improved adhesion is useful.

It is a preferred aspect to use a blocked isocyanate cross-linking agent that is stable in an aqueous solution as the isocyanate cross-linking agent. Specific examples of the blocked isocyanate cross-linking agent include alcohols, phenols, thiophenols, amines, imines, oximes, lactams, and activated methylenes. Based compounds, thiols, imines, ureas, diaryl compounds and sodium bisulfite, etc., areocyanate cross-linking agents that can be commonly used when preparing adhesive layers and antistatic layers (such as the above-mentioned adhesives) A cross-linking agent obtained by blocking an isocyanate compound (isocyanate-based cross-linking agent) used in the layer.

As the melamine-based crosslinking agent, melamine, alkylated melamine, methylol melamine, alkoxylated methyl melamine, etc. can be used.

The antistatic layer in the technology disclosed here may contain antioxidants, colorants (pigments, dyes, etc.), fluidity regulators (thixotropic agents, thickeners, etc.), film-forming aids, surfactants ( Defoamer, etc.), preservatives, UV absorbers and other additives.

<Formation of Antistatic Layer> The above-mentioned antistatic layer can be appropriately formed by a method including the following steps: dissolving the above-mentioned conductive polymer component, etc. and additives used as necessary in an appropriate solvent (water, etc.) The liquid composition (coating material for antistatic layer formation, antistatic agent composition, antistatic agent solution) is applied to the supporting film. For example, a method in which the above-mentioned coating material is applied to one side of the support film, dried, and cured (heat treatment, ultraviolet treatment, etc.) if necessary, can be preferably used. The NV (non-volatile component) of the coating material can be set to, for example, 5 mass % or less (typically 0.05 mass % to 5 mass %), and is usually set to 1 mass % or less (typically 0.10 mass % to 1 mass %). %) is appropriate. When forming an antistatic layer with a small thickness, it is preferable to set the NV of the coating material to, for example, 0.05% by mass to 0.50% by mass (eg, 0.10% by mass to 0.40% by mass). By using such a low NV coating material, a more uniform antistatic layer can be formed.

The solvent constituting the coating material is preferably a solvent that can stably dissolve the components forming the antistatic layer. The solvent may be an organic solvent, water or a mixed solvent thereof. As the above-mentioned organic solvent, for example, it is possible to use esters such as ethyl acetate; ketones such as methyl ethyl ketone, acetone, and cyclohexanone; tetrahydrofuran (THF), dihydrofuran, etc. Alkanes and other cyclic ethers; n-hexane, cyclohexane and other aliphatic or alicyclic hydrocarbons; toluene, xylene and other aromatic hydrocarbons; methanol, ethanol, n-propanol, isopropanol, cyclohexanol and other fats Racial or alicyclic alcohols; glycol ethers such as alkylene glycol monoalkyl ether (for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether), dialkylene glycol monoalkyl ether, etc. one or more than two of them. In a preferred aspect, the solvent of the above-mentioned coating material is water or a mixed solvent with water as the main component (for example, a mixed solvent of water and ethanol).

<Properties of Antistatic Layer> The thickness of the antistatic layer is typically 3 nm to 500 nm, preferably 3 nm to 100 nm, and more preferably 3 nm to 60 nm. If the thickness of the antistatic layer is too small, it will be difficult to form the antistatic layer uniformly (for example, the thickness of the antistatic layer will vary depending on the position), so it may easily cause problems in the appearance of the surface protection sheet. Uneven. On the other hand, when the antistatic layer is too thick, the properties (optical properties, dimensional stability, etc.) of the supporting film may be affected.

In a preferred aspect of the surface protection sheet disclosed here, the surface resistance value (Ω/□) measured on the surface of the antistatic layer is preferably less than 1.0×10 ¹¹ , more preferably less than 5.0×10 ¹⁰ , and further preferably less than 2.0× 10 ¹⁰ . A surface protection sheet exhibiting a surface resistance value within the above range can be suitably used as a surface protection sheet used during processing or transportation of electrostatic-resistant items such as liquid crystal cells and semiconductor devices. In addition, the above-mentioned surface resistance value can be calculated from the surface resistance value measured in a gas environment of 23° C. and 50% RH using a commercially available insulation resistance measuring device.

The surface protection sheet disclosed here may be implemented in an aspect including other layers in addition to the support film (base material), adhesive layer, and antistatic layer. Examples of the arrangement of the "other layer" include between the support film and the antistatic layer, between the support film and the adhesive layer, and the like. For example, the layer disposed between the support film and the adhesive layer may be a primer layer (anchoring layer) that improves anchoring properties to the adhesive layer, an antistatic layer, or the like. The surface protection sheet (adhesive sheet) may be a surface protection sheet (adhesive sheet) in which an antistatic layer is separately arranged between the support film and the adhesive layer, and an anchoring layer is further arranged between the antistatic layer and the adhesive layer.

<Optical member> The optical member of the present invention is preferably protected by the above-mentioned surface protection sheet. The surface protection sheet can be used for surface protection during processing, transportation, shipment, etc., and is useful for protecting the surface of the optical member (polarizing film, etc.). In particular, it is very useful for thin optical members (polarizing films, etc.) or display panels because the surface protection sheet can be easily peeled off at a stage when the surface protection sheet is no longer needed.

The optical member of the present invention is a polarizing film containing a polarizer, and it is preferable that the thickness of the polarizer is 8 μm or less. In particular, thin optical members with a polarizer thickness of 8 μm or less tend to have a peeling charge suppression effect that is easily deteriorated. By applying the above-mentioned surface protection sheet, the problem of peeling charging is improved, and it is useful for optical members (polarizing films). The preferred aspect.

<Polarizing Film> As the polarizing film, a polarizing film having the following structure can be used: a polarizing element, a transparent protective film laminated on at least one side of the polarizing element, and a first adhesive layer laminated on at least one side of the polarizing film. composition.

<Polarizer> A polarizer using polyvinyl alcohol-based resin can be used as the above-mentioned polarizer. Examples of polarizers include adsorbing iodine or dichroism on hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and ethylene-vinyl acetate copolymer partially saponified films. Films obtained by uniaxially stretching dichroic substances such as dyes, polyene oriented films such as dehydration products of polyvinyl alcohol or dehydrochlorination products of polyvinyl chloride, etc. Among them, a polarizer containing a polyvinyl alcohol-based film and a dichroic substance such as iodine is preferred.

A polarizer obtained by dyeing the polyvinyl alcohol-based film with iodine and uniaxially stretching it can be produced, for example, by immersing polyvinyl alcohol in an aqueous solution of iodine, dyeing it, and stretching it to its original length. 3 to 7 times. Boric acid, zinc sulfate, zinc chloride, etc. may be contained as needed, and it may be immersed in the aqueous solution of potassium iodide, etc. In addition, if necessary, the polyvinyl alcohol-based film may be immersed in water and washed before dyeing. Washing the polyvinyl alcohol-based film with water not only removes dirt and anti-blocking agents from the surface of the polyvinyl alcohol-based film, but also has the effect of preventing uneven dyeing and other unevenness by swelling the polyvinyl alcohol-based film. Stretching may be performed after dyeing with iodine, or may be performed at the same time as dyeing. In addition, stretching may be performed and then dyed with iodine. Stretching can also be performed in an aqueous solution of boric acid, potassium iodide, or the like or in a water bath.

From the viewpoint of thinning, the thickness of the polarizer is preferably 8 μm or less, more preferably 7 μm or less, and still more preferably 6 μm or less. On the other hand, the thickness of the polarizer is preferably 2 μm or more, and more preferably 3 μm or more. Such a thin polarizer has small thickness unevenness, excellent visibility, and small dimensional changes, so it has excellent durability against thermal shock. Typical thin polarizers include Japanese Patent No. 4751486, Japanese Patent No. 4751481, Japanese Patent No. 4815544, Japanese Patent No. 5048120, International Publication No. 2014/077599, International Publication No. Disclosed are the thin polarizers described in Booklet No. 2014/077636, etc. or the thin polarizers obtained by the manufacturing methods described therein.

The above-mentioned polarizer is preferably configured so that the optical characteristics represented by the single transmittance T and the polarization degree P satisfy the following formula: P>-(100.929T-42.4-1)×100 (where T<42.3) or P≥99.9 (where, T≥42.3). The polarizer configured to satisfy the above conditions uniquely has the performance required for a liquid crystal television display using a large display element. Specifically, the contrast ratio is 1000:1 or more and the maximum brightness is 500cd/m2 ^or more. For other uses, for example, it can be attached to the viewing side of an organic EL unit.

As the thin polarizer, it is preferable to use a method that can stretch at a high magnification even in a manufacturing method including a step of stretching in a laminated state and a step of dyeing and can improve the polarizing performance. The thin polarizing element obtained by the manufacturing method including the step of stretching in a boric acid aqueous solution as described in Japanese Patent No. 4751486, Japanese Patent No. 4751481, and Japanese Patent No. 4815544 is particularly preferred. A thin polarizer obtained by a manufacturing method including a step of supplementarily stretching in air before stretching in a boric acid aqueous solution, described in Specification No. 4751481 and Japanese Patent No. 4815544. These thin polarizers can be obtained by a manufacturing method including a step of stretching a polyvinyl alcohol-based resin (hereinafter also referred to as PVA-based resin) layer and a stretching resin base film in a laminated state and a step of dyeing. . According to this manufacturing method, even if the PVA-based resin layer is thin, it can be stretched without problems such as breakage due to stretching by being supported by the resin base film for stretching.

<Transparent Protective Film> The material constituting the transparent protective film is not particularly limited, but materials excellent in transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, etc. are preferred. Examples include: polyester polymers such as polyethylene terephthalate and polyethylene naphthalate; cellulose polymers such as diacetyl cellulose and triacetyl cellulose; polymethylmethacrylate Acrylic polymers such as ester; styrenic polymers such as polystyrene or acrylonitrile-styrene copolymer (AS resin); polycarbonate polymers, etc. In addition, polyethylene, polypropylene, cyclic or reduced Polyolefins with an olefin structure, polyolefin polymers such as ethylene-propylene copolymers, vinyl chloride polymers, amide polymers such as nylon or aromatic polyamides, amide imine polymers, and polyamide polymers Polyether ester polymers, polyether ether ketone polymers, polyphenylene sulfide polymers, vinyl alcohol polymers, vinylidene chloride polymers, vinyl butyral polymers, aryl esters Polymers, polyoxymethylene polymers, epoxy polymers or blends of the above polymers are examples of polymers that form the transparent protective film. These transparent protective films are usually bonded to polarizers through an adhesive layer. Furthermore, the transparent protective film may contain one or more suitable additives. Examples of additives include ultraviolet absorbers, antioxidants, lubricants, plasticizers, release agents, anti-coloring agents, flame retardants, nucleating agents, antistatic agents, pigments, colorants, and the like.

The content of the thermoplastic resin in the transparent protective film is preferably 50% to 100% by mass, more preferably 50% to 99% by mass, even more preferably 60% to 98% by mass, and particularly preferably 70% to 97% by mass. Mass %. When the content of the thermoplastic resin in the transparent protective film is 50% by mass or less, the high transparency originally possessed by the thermoplastic resin may not be fully expressed.

The thickness of the transparent protective film can be appropriately determined, but generally speaking, from the viewpoint of strength, workability such as handleability, and thin-layer properties, it is preferably 5 μm to 50 μm, and more preferably 5 μm to 45 μm.

Functional layers such as a hard coating layer, an anti-reflective layer, an anti-adhesive layer, a diffusion layer or an anti-glare layer can be provided on the surface of the above-mentioned transparent protective film that is not connected to the polarizer. Furthermore, in addition to being provided on the transparent protective film itself, the functional layers such as the hard coating layer, anti-reflective layer, anti-adhesive layer, diffusion layer or anti-glare layer may also be provided separately from the transparent protective film.

The above-mentioned transparent protective film and the polarizer are laminated through an intermediate layer (intermediate layer) such as an adhesive layer, an adhesive layer, and a primer layer (primer layer). At this time, it is desirable to laminate the two without an air gap through an intermediate layer.

The above-mentioned adhesive layer is formed of an adhesive. The type of adhesive is not particularly limited, and various adhesives can be used. The above-mentioned adhesive layer is not particularly limited as long as it is optically transparent. As the adhesive, various forms of adhesives such as water-based, solvent-based, hot-melt, and active energy ray-curable types can be used, and water-based adhesives or adhesives are preferred. Active energy ray curable adhesive.

Examples of the water-based adhesive include isocyanate-based adhesives, polyvinyl alcohol-based adhesives, gelatin-based adhesives, vinyl-based latex type, water-based polyester, and the like. Aqueous adhesives are usually used in the form of adhesives converted from aqueous solutions, and usually contain 0.5% to 60% by weight of solid content.

The active energy ray curable adhesive is an adhesive that is cured by active energy rays such as electron rays and ultraviolet rays (radical curing type and cation curing type), and can be used in the form of electron ray curing type and ultraviolet ray curing type, for example. As the active energy ray curable adhesive, for example, a photo radical curable adhesive can be used. When a photoradically curable active energy ray-curable adhesive is used as the ultraviolet curable type, the adhesive contains a radically polymerizable compound and a photopolymerization initiator.

The application method of the above-mentioned adhesive can be appropriately selected according to the viscosity and target thickness of the adhesive. Examples of coating methods include reverse coaters, gravure coaters (direct gravure coaters, reverse gravure coaters, or offset gravure coaters), and bar reverse coaters. machine, roller coater, die coater, rod coater, rod coater, etc. In addition, dipping method and other methods can be appropriately used for coating.

In addition, when applying an aqueous adhesive or the like, the adhesive is preferably applied so that the thickness of the final adhesive layer is 30 nm to 300 nm, and more preferably 60 nm to 150 nm. On the other hand, when using an active energy ray-curable adhesive, it is preferable to perform so that the thickness of the said adhesive layer may become 0.2 micrometer - 20 micrometer.

Furthermore, when stacking the polarizer and the transparent protective film, an easy-adhesion layer may be provided between the transparent protective film and the adhesive layer. The easy-adhesion layer can be formed of various resins having a polyester skeleton, a polyether skeleton, a polycarbonate skeleton, a polyurethane skeleton, a polysiloxane skeleton, a polyamide skeleton, a polyimide skeleton, a polyvinyl alcohol skeleton, and the like. These polymer resins may be used individually by 1 type, or in combination of 2 or more types. In addition, when forming the easily adhesive layer, other additives may be added. Specifically, stabilizers such as thickeners, ultraviolet absorbers, antioxidants, and heat-resistant stabilizers can be further used.

The above-mentioned adhesive layer is formed of an adhesive (adhesive composition). As the adhesive, various adhesives can be used, for example, rubber adhesives, acrylic adhesives, polysiloxane adhesives, polyurethane adhesives, vinyl alkyl ether adhesives, polyethylene adhesives, etc. Pyrrolidone adhesives, polyacrylamide adhesives, cellulose adhesives, etc. The adhesive base polymer is selected according to the type of adhesive mentioned above. Among the above-mentioned adhesives, acrylic adhesives are preferably used because they have excellent optical transparency, exhibit appropriate adhesive properties such as wettability, cohesiveness, and adhesion, and are excellent in weather resistance, heat resistance, and the like.

The above-mentioned undercoat layer (primer layer) is formed to improve the adhesion between the polarizer and the transparent protective film. The material constituting the primer layer is not particularly limited as long as it exerts a certain degree of strong adhesion to both the base film and the polyvinyl alcohol resin layer. For example, a thermoplastic resin excellent in transparency, thermal stability, stretchability, etc. can be used. Examples of the thermoplastic resin include acrylic resins, polyolefin resins, polyester resins, polyvinyl alcohol resins, or mixtures thereof.

<First adhesive layer> A polarizing film in which a first adhesive layer is laminated on at least one side of the polarizing film may be used. The first adhesive layer may have a surface opposite to the surface in contact with the polarizing film. Other optical members (for example, phase difference films, liquid crystal display devices, etc.) are laminated thereon. In addition, the first adhesive layer may also be directly laminated on the above-mentioned primer layer that has been laminated on the polarizer. An appropriate adhesive can be used in the formation of the first adhesive layer, and its type is not particularly limited. Examples of the adhesive include rubber adhesives, acrylic adhesives, polysiloxane adhesives, polyurethane adhesives, vinyl alkyl ether adhesives, polyvinyl alcohol adhesives, and polyethylene adhesives. Based on pyrrolidone adhesives, polyacrylamide adhesives, cellulose adhesives, etc. Among these adhesives, it is preferable to use adhesives that have excellent optical transparency, exhibit adhesive properties such as suitable wettability, cohesiveness, and adhesiveness, and are excellent in weather resistance, heat resistance, and the like. As an adhesive exhibiting such characteristics, an acrylic adhesive is preferably used.

As a method of forming the first adhesive layer, for example, the above-mentioned adhesive is applied to a separation member that has been peeled off, and the polymerization solvent and the like are dried and removed to form an adhesive layer, and then transferred to a polarizing film; or, a method of coating the above-mentioned adhesive on a polarizing film and drying and removing the polymerization solvent to form an adhesive layer on the polarizer. Furthermore, when applying the adhesive, one or more solvents other than the polymerization solvent may be newly added as appropriate. As the release-treated separation member, a polysiloxane separation member is preferably used.

In the step of applying the adhesive of the present invention to such a separator and drying it to form an adhesive layer, an appropriate method can be appropriately used according to the purpose as a method of drying the adhesive. It is preferable to use a method of heating and drying the coating film. The heating and drying temperature is preferably 40°C to 200°C, more preferably 50°C to 180°C, and particularly preferably 70°C to 170°C. By setting the heating temperature to the above range, an adhesive having excellent adhesive properties can be obtained.

As a method of forming the first adhesive layer, various methods can be used. Specific examples include roll coating, kiss roll coating, gravure coating, reverse coating, roll brushing, spray coating, dip roll coating, rod coating, knife coating, and air knife coating. , curtain coating, lip die coating, extrusion coating method using die coating machine, etc.

The thickness of the first adhesive layer is preferably 2 μm to 50 μm, more preferably 2 μm to 40 μm, and even more preferably 5 μm to 35 μm.

The above-mentioned separator can protect the adhesive surface of the first adhesive layer until it is actually used. Examples of the constituent materials of the separator include: plastic films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester films; porous materials such as paper, cloth, and nonwoven fabrics; mesh, hair, etc. Appropriate sheet-like materials such as bubble sheets, metal foils, and laminates of these materials are preferably used, and plastic films are preferably used from the viewpoint of excellent surface smoothness. The plastic film is not particularly limited as long as it can protect the adhesive layer. Examples include polyethylene film, polypropylene film, polybutylene film, polybutadiene film, and polymethylpentene film. Polyethylene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, ethylene-vinyl acetate copolymer film, etc.

The above-mentioned separation parts can also be subjected to release and antifouling treatment using polysiloxane, fluorine-containing, long-chain alkyl or fatty acid amide release agents or silica powder as needed, or they can be coated with Anti-static treatment such as cloth type, kneading type, evaporation type, etc. In particular, peelability from the first adhesive layer can be further improved by appropriately subjecting the surface of the release film to release treatments such as polysiloxane treatment, long-chain alkyl treatment, and fluorine treatment.

The thickness of the separator is generally preferably 5 μm to 50 μm, more preferably 20 μm to 40 μm. Example

Hereinafter, Examples etc. which specifically illustrate the structure and effects of the present invention will be described, but the present invention is not limited to these Examples. In addition, the blending content and characteristic evaluation in Examples etc. were measured as follows. In addition, Table 1 shows the physical property values of the (meth)acrylic polymer used in the adhesive composition, Table 2 shows the blending ratio of the adhesive composition, and Table 3 shows the characteristics of the surface protection sheet. Evaluation results.

<Measurement method of polymer physical properties> The specific measurement method of polymer physical properties is described below.

<Measurement of weight average molecular weight (Mw)> The weight average molecular weight (Mw) of the (meth)acrylic polymer used in the present invention was measured using a GPC device (HLC-8220GPC) manufactured by Tosoh Corporation. The measurement conditions are as follows.

Sample concentration: 0.2 mass% (THF solution) Injection volume: 10μl Eluate: THF Flow rate: 0.6ml/min Measurement temperature: 40℃ Column: Sample column: TSKguardcolumn SuperHZ-H (one) + TSKgel SuperHZM-H ( Two columns) Reference column: TSKgel SuperH-RC (one column) Detector: Differential refractometer (RI) In addition, the weight average molecular weight (Mw) is calculated in terms of polystyrene conversion.

<Theoretical Value of Glass Transition Temperature (Tg)> The glass transition temperature Tg (°C) was determined by the following formula using the following literature value as the glass transition temperature Tgn (°C) of the homopolymer obtained from each monomer.

Formula: 1/(Tg+273)=Σ[Wn/(Tgn+273)] [In the formula, Tg(℃) represents the glass transition temperature of the copolymer, Wn(-) represents the mass fraction of each monomer, Tgn (°C) represents the glass transition temperature of the homopolymer obtained from each monomer, and n represents the type of each monomer. ] Literature values: 2-ethylhexyl acrylate (2EHA): -70℃ 2-hydroxyethyl acrylate (HEA): -15℃ 4-hydroxybutyl acrylate (4HBA): -32℃ Acrylic acid (AA): 106 ℃

Furthermore, as literature values, reference was made to "Synthesis, Design and Development of New Applications of Acrylic Resins" (published by Japan Central Business Development Center Publishing Department) and "Polymer Handbook" (John Wiley & Sons).

<Production of optical components (polarizing films)> (Production of polarizing parts) Amorphous isophthalic acid copolymerized polyethylene terephthalate (IPA copolymerized PET) film with a water absorption rate of 0.75% and a Tg of 75°C (Thickness: 100 μm) One side of the base material is corona-treated, and on the corona-treated side, polyvinyl alcohol (PVA) is coated at a ratio of 9:1, with a degree of polymerization of 4200 and a saponification degree of 99.2 M at 25°C. %) and acetyl-acetyl modified PVA (degree of polymerization 1200, degree of acetyl-acetyl modification 4.6%, saponification degree 99.0 mol% or more, manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "GOHSEFIMER Z200") The aqueous solution was dried to form a PVA-based resin layer with a thickness of 11 μm, thereby producing a laminate. The obtained laminate was uniaxially stretched to 2.0 times along the longitudinal direction (length direction) between rollers with different circumferential speeds in an oven at 120° C. (air-assisted stretching treatment). Next, the laminated body was immersed in an insolubilization bath (a boric acid aqueous solution in which 4 parts by mass of boric acid was mixed with 100 parts by mass of water) having a liquid temperature of 30° C. for 30 seconds (insolubilization treatment). Next, the polarizing film was immersed in a dyeing bath with a liquid temperature of 30° C. while adjusting the iodine concentration and immersion time so that the polarizing film reached a predetermined transmittance. In this example, 0.2 mass part of iodine and 1.0 mass part of potassium iodide were mixed with 100 mass parts of water, and it was immersed in the iodine aqueous solution for 60 seconds (dyeing process). Next, it was immersed in a crosslinking bath (a boric acid aqueous solution obtained by mixing 3 parts by mass of potassium iodide and 3 parts by mass of boric acid with respect to 100 parts by mass of water) with a liquid temperature of 30° C. for 30 seconds (crosslinking treatment). Then, the laminated body was immersed in a boric acid aqueous solution with a liquid temperature of 70° C. (an aqueous solution obtained by blending 4 parts by mass of boric acid and 5 parts by mass of potassium iodide with respect to 100 parts by mass of water) and at the same time, it was moved between rollers with different circumferential speeds. Uniaxial stretching was performed in the longitudinal direction (length direction) so that the total stretching ratio was 5.5 times (water stretching treatment). Then, the laminated body was immersed in a cleaning bath (an aqueous solution in which 4 parts by mass of potassium iodide was mixed with 100 parts by mass of water) having a liquid temperature of 30° C. (cleaning treatment). Thus, an optical film laminate including a polarizer (PVA-based resin layer) with a thickness of 5 μm was obtained.

(Formation of adhesive layer) To a reaction vessel equipped with a condenser tube, a nitrogen introduction tube, a thermometer and a stirring device, add 100 parts of butyl acrylate, 3 parts of acrylic acid, 0.1 part of 2-hydroxyethyl acrylate and ethyl acetate. A solution was prepared by adding 0.3 parts of 2,2'-azobisisobutyronitrile. Next, the solution was stirred while blowing nitrogen gas into it, and reacted at 55° C. for 8 hours, thereby obtaining a solution containing an acrylic polymer with a weight average molecular weight of 2.2 million. Furthermore, ethyl acetate was added to the solution containing the acrylic polymer to obtain an acrylic polymer solution in which the solid content concentration was adjusted to 30%. With respect to 100 parts of the solid content of the acrylic polymer solution, 0.5 parts of a cross-linking agent containing an isocyanate group-containing compound as a main component (manufactured by Tosoh Co., Ltd., trade name "Coronate") was sequentially blended as a cross-linking agent. L") and 0.075 parts of γ-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Industry Co., Ltd., trade name "KMB-403") as a silane coupling agent, to prepare an adhesive solution. The above adhesive solution was applied to the surface of a release sheet (separator) made of a polyethylene terephthalate film (thickness 38 μm) that had been peeled off so that the thickness after drying was 25 μm, and dried. , thus forming an adhesive layer.

(Preparation of polarizing film 1) A 40 μm-thick triacetyl cellulose (TAC) film (trade name "Konica Minolta Optical Instruments Co., Ltd." was bonded to the polarizer side of the above-mentioned optical film laminate via a vinyl alcohol adhesive) TAC film KC4UY"). Next, the amorphous IPA copolymerized PET film base material was peeled off, and the above-mentioned adhesive layer was bonded to the peeled surface, thereby producing the polarizing film 1 .

(Preparation of polarizing film 2) An acrylic hard coat was applied to one side of a 40 μm thick triacetyl cellulose (TAC) film (trade name "TAC film KC4UY" manufactured by Konica Minolta Optical Instruments). A coating liquid with a solid content concentration of 25% by weight obtained by dispersing resin (manufactured by Dainippon Ink Chemical Industry Co., Ltd., UNIDIC 17-813) in isopropyl alcohol was dried at 80°C for 2 minutes and further subjected to ultraviolet treatment. Thus, a TAC film having a hard coat layer having a thickness of 7 μm was produced. Next, the TAC film on which the hard coat layer is formed is bonded to the polarizer side of the optical film laminate through a vinyl alcohol adhesive (so that the adhesive contacts the surface opposite to the surface on which the hard coat layer is formed). Next, the amorphous IPA copolymerized PET film base material was peeled off, and the above-mentioned adhesive layer was bonded to the peeled surface, thereby producing the polarizing film 2 .

<Preparation method> The specific synthesis method of the (meth)acrylic polymer and the preparation method of the adhesive composition, etc. are described below.

<Preparation of (meth)acrylic polymer 1 solution> 95 parts by mass of 2-ethylhexyl acrylate (2EHA) and 2-ethylhexyl acrylate were placed in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen introduction pipe, and a condenser. 5 parts by mass of hydroxyethyl ester (HEA), 0.2 parts by mass of 2,2'-azobisisobutyronitrile as a polymerization initiator, and 150 parts by mass of ethyl acetate were introduced with nitrogen while slowly stirring, and the liquid in the flask was The temperature was kept near 65° C., and a polymerization reaction was performed for 6 hours, thereby preparing a (meth)acrylic polymer 1 solution (40 mass %). The (meth)acrylic polymer 1 has a weight average molecular weight (Mw) of 550,000 and a glass transition temperature (Tg) of -68°C.

<Preparation of (meth)acrylic polymer 2 solution> 95 parts by mass of 2-ethylhexyl acrylate (2EHA) and 2-ethyl acrylate were placed in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen introduction pipe, and a condenser. 4.9 parts by mass of hydroxyethyl ester (HEA), 0.1 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, while slowly stirring Nitrogen gas was introduced, the liquid temperature in the flask was maintained at around 65°C, and a polymerization reaction was performed for 6 hours to prepare a (meth)acrylic polymer 2 solution (40 mass %). The (meth)acrylic polymer 2 has a weight average molecular weight (Mw) of 550,000 and a glass transition temperature (Tg) of -68°C.

<Preparation of (meth)acrylic polymer 3 solution> 98.5 parts by mass of 2-ethylhexyl acrylate (2EHA) and 4-ethyl acrylate were put into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction pipe, and a condenser. 1.5 parts by mass of hydroxybutyl ester (4HBA), 0.006 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, while slowly stirring Nitrogen gas was introduced, the liquid temperature in the flask was maintained at around 65°C, and a polymerization reaction was performed for 6 hours, thereby preparing a (meth)acrylic polymer 3 solution (40 mass %). The (meth)acrylic polymer 3 has a weight average molecular weight (Mw) of 480,000 and a glass transition temperature (Tg) of -70°C.

<Preparation of (meth)acrylic polymer 4 solution> 90.9 parts by mass of 2-ethylhexyl acrylate (2EHA) and acrylic acid 4- were placed in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen introduction pipe, and a condenser. 9.1 parts by mass of hydroxybutyl ester (4HBA), 0.02 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, while slowly stirring Nitrogen gas was introduced, the liquid temperature in the flask was maintained at around 65°C, and a polymerization reaction was performed for 6 hours to prepare a (meth)acrylic polymer 4 solution (40 mass %). The (meth)acrylic polymer 4 has a weight average molecular weight (Mw) of 540,000 and a glass transition temperature (Tg) of -67°C.

<Preparation of Solution 1 for Antistatic Layer> 100 parts by mass of polyester resin VYLONAL MD-1480 (25% aqueous solution, manufactured by Toyobo Co., Ltd.) as a binder in terms of solid content and 75 parts by mass in terms of solid content parts of polyaniline sulfonic acid (aquapass, weight average molecular weight 40,000, manufactured by Mitsubishi Rayon Co., Ltd.) as a conductive polymer, and 10 parts by mass of polyaniline sulfonic acid (aquapass, weight average molecular weight 40,000, manufactured by Mitsubishi Rayon Co., Ltd.) as a cross-linking agent using diisopropylamine as a cross-linking agent. Add the isocyanurate body of methylene diisocyanate and 30 parts by mass of oleamide as a lubricant in terms of solid content to a mixed solvent of water/ethanol (1/3), and stir for about 20 minutes to mix thoroughly. In this way, a solution 1 for an antistatic layer containing approximately 0.4% by mass of NV was prepared.

<Preparation of Solution 2 for Antistatic Layer> 100 parts by mass of polyester resin VYLONAL MD-1480 (25% aqueous solution, manufactured by Toyobo Co., Ltd.) as a binder in terms of solid content, 100 parts by mass in terms of solid content parts of poly(3,4-ethylenedioxythiophene) (PEDOT)/polystyrenesulfonic acid (PSS) (manufactured by Baytron P, H.C. Starck Co., Ltd.) as a conductive polymer, based on solid content: 10 parts by mass of an isocyanurate body of hexamethylene diisocyanate blocked with diisopropylamine as a cross-linking agent was added to a mixed solvent of water/ethanol (1/1), and stirred for about 20 minutes. Mix thoroughly. In this way, a solution 2 for an antistatic layer with an NV of approximately 0.4% was prepared.

<Preparation of support film 1 with antistatic layer> As a support film, a transparent polyethylene terephthalate (PET) film with a thickness of 38 μm, a width of 30 cm, and a length of 40 cm was corona-treated on one side. The above antistatic layer solution 1 was applied so that the thickness after drying would be 30 nm. The coated material was heated to 130° C. for 1 minute and dried, thereby producing an antistatic layer-attached support film 1 having an antistatic layer on one side of the PET film.

<Preparation of support film 2 with antistatic layer> As a support film, a transparent polyethylene terephthalate (PET) film with a thickness of 38 μm, a width of 30 cm, and a length of 40 cm was corona-treated on one side. The above antistatic layer solution 2 was applied so that the thickness after drying would be 30 nm. The coated material was heated to 130° C. for 1 minute and dried, thereby producing an antistatic layer-attached support film 2 having an antistatic layer on one side of the PET film.

Table 1

<Example 1> <Preparation of surface protection sheet> The above-mentioned (meth)acrylic polymer 1 solution (40 mass%) was diluted to 20 mass% with ethyl acetate, and 500 parts by mass of the solution (100 mass parts of solid content parts), 0.5 parts by mass of 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide salt as ionic compound 1, and 0.5 parts by mass of 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide as a compound having an oxyalkylene group were added. 0.5 parts by mass of chain organopolysiloxane (KF-6004 manufactured by Shin-Etsu Chemical Industry Co., Ltd.) and an isocyanurate body (Eastern) of hexamethylene diisocyanate, an aliphatic isocyanate compound, as a cross-linking agent Manufactured by Cao Co., Ltd., Coronate HX) 3 parts by mass (3 parts by mass solid content), 3 parts by mass dibutyltin dilaurate (1 mass % ethyl acetate solution) as a cross-linking catalyst (0.03 parts by mass solid content) , and mixed and stirred to prepare adhesive composition 1 (solution). The above-mentioned adhesive composition 1 (solution) was applied to the other side of the above-mentioned support film 1 with an anti-static layer that did not have the above-mentioned anti-static layer, and heated at 130°C for 1 minute to form an adhesive with a thickness of 15 μm. agent layer. Next, the polysiloxane-treated surface of a polyethylene terephthalate film (thickness 25 μm), which is a separator that has been polysiloxane-treated on one side, was bonded to the surface of the above-mentioned adhesive layer. Surface protection sheet.

<Example 2> <Preparation of surface protection sheet> The above (meth)acrylic polymer solution 2 (40 mass%) was diluted to 20 mass% with ethyl acetate, and 500 parts by mass of the solution (100 mass parts of solid content parts), 0.5 parts by mass of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imine as ionic compound 2, and oxyalkylene as a compound having an oxidized alkylene group were added. 0.5 parts by mass of organopolysiloxane (KF-353, manufactured by Shin-Etsu Chemical Industry Co., Ltd.), as a cross-linking agent, and an isocyanurate body of hexamethylene diisocyanate as an aliphatic isocyanate compound ( Manufactured by Tosoh Co., Ltd., Coronate HX) 3 parts by mass (3 parts by mass solid content), 3 parts by mass dibutyltin dilaurate (1 mass % ethyl acetate solution) as a cross-linking catalyst (0.03 parts by mass solid content) ), and mixed and stirred to prepare adhesive composition 2 (solution). The above-mentioned adhesive composition 2 (solution) was applied to the other side of the above-mentioned support film 2 with an anti-static layer that did not have the above-mentioned anti-static layer, and heated at 130°C for 1 minute to form an adhesive with a thickness of 15 μm. agent layer. Next, the polysiloxane-treated surface of a polyethylene terephthalate film (thickness 25 μm), which is a separator that has been polysiloxane-treated on one side, was bonded to the surface of the above-mentioned adhesive layer. Surface protection sheet.

<Examples 3 to 9> Based on the blending contents and blending ratio in Table 2, a surface protection sheet was produced in the same manner as in Example 2. In addition, the blending amount in a table shows a solid content.

<Comparative Examples 1 to 4> Based on the blending contents and blending ratio in Table 2, a surface protection sheet was produced in the same manner as in Example 1. In addition, the blending amount in a table shows a solid content.

Table 2

The abbreviations in Table 1 and Table 2 are explained below. <Monomer> 2EHA: 2-ethylhexyl acrylate (main monomer) HEA: 2-hydroxyethyl acrylate (hydroxyl-containing (meth)acrylic monomer) 4HBA: 4-hydroxybutyl acrylate (hydroxyl-containing (meth)acrylic monomer) Meth)acrylic monomer) AA: Acrylic (carboxyl-containing (meth)acrylic monomer)

<Antistatic agent (onium salt)> Ionic compound 1: 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide salt (melting point: -13°C) Ionic compound 2: 1-ethyl 1-Butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt (melting point -15°C) Ionic compound 3: 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl) ) imine salt (melting point -4°C) Ionic compound 4: 1-ethyl-3-methylpyridinium bis(fluorosulfonyl)imine salt (melting point -6°C) Ionic compound 5: 1-hexyl Pyridinium bis(trifluoromethanesulfonyl)imine salt (melting point 0°C) Ionic compound 6: N-methyl-N-propylpiperidinium bis(trifluoromethanesulfonyl)imine salt (melting point 12℃) Ionic compound 7: tributylmethylphosphonium bis(trifluoromethanesulfonyl)imide salt (melting point 16℃)

<Compound having an oxyalkylene group> KF353: Organopolysiloxane having an oxyalkylene chain in the side chain (manufactured by Shin-Etsu Chemical Industry Co., Ltd., trade name: KF-353) KF6004: Having oxygen in the straight chain Alkylene chain organopolysiloxane (manufactured by Shin-Etsu Chemical Industry Co., Ltd., trade name: KF-6004)

<Fluorinated oligomer> F-562: Fluorinated oligomer, weight average molecular weight 27900 (manufactured by DIC Corporation, trade name: MegafacF-562)

<Evaluation method> Specific measurement and evaluation methods are described below.

<Measurement of peeling charging voltage of Examples 1 to 7 and Comparative Examples 1 to 4> As shown in Fig. 1, the surface protection sheet 2 was cut into a size of 70 mm in width and 130 mm in length, the separator was peeled off, and then a manual roller was used to make a single The end protrudes 30mm and is crimped to the surface (TAC surface) of the above-mentioned polarizing film 1, and the polarizing film 1 has been bonded to the acrylic resin plate 4 (thickness: 2mm, width: 70mm, length: 100mm) that has been pre-statically removed. superior.

Leave it in a low temperature environment of 0°C for 1 day, and then set the sample at the specified position as shown in Figure 1. A single end protruding 30 mm was fixed to an automatic winding machine (not shown), and peeling was performed at a peeling angle of 150° and a peeling speed of 30 m/min (high-speed peeling). The potential generated at this time on the surface of the polarizing film (peeling charging voltage: absolute value, kV) was measured using a potential measuring device 1 (model number "STATIRON DZ-4" manufactured by SHISHIDO Electrostatics Co., Ltd.) fixed at the center of the polarizing film. The measurement was carried out in an environment of 23℃×50%RH.

The adhesive surface of the adhesive layer used in the above-mentioned surface protection sheet is adhered to the TAC surface (polarizing film surface) for 1 day (left) in a low temperature environment of 0°C, and then peeled off at a peeling angle of 150° and a peeling speed of 30m/min. The potential on the surface of the polarizing film (peeling charging voltage: kV, absolute value) generated during (high-speed peeling) is preferably 0.6 kV or less, more preferably 0.5 kV or less, and still more preferably 0.4 kV or less. When the above-mentioned peeling charging voltage exceeds 0.6 kV, it may cause damage to a liquid crystal driver, etc., which is not preferable.

<Measurement of Peeling Charging Voltage in Examples 8 and 9> As shown in Figure 1, the surface protection sheet 2 was cut into a size of 70 mm in width and 130 mm in length, the separator was peeled off, and a manual roller was used so that a single end protruded by 30 mm. The polarizing film 2 is pressed onto the surface (hard-coated surface) of the polarizing film 2, and the polarizing film 2 has been bonded to the acrylic resin plate 4 (thickness: 2 mm, width: 70 mm, length: 100 mm) that has been pre-statically removed.

Leave it in a low temperature environment of 0°C for 1 day, and then set the sample at the specified position as shown in Figure 1. A single end protruding 30 mm was fixed to an automatic winding machine (not shown), and peeling was performed at a peeling angle of 150° and a peeling speed of 30 m/min (high-speed peeling). The potential generated at this time on the surface of the polarizing film (peeling charging voltage: absolute value, kV) was measured using a potential measuring device 1 (model number "STATIRON DZ-4" manufactured by SHISHIDO Electrostatics Co., Ltd.) fixed at the center of the polarizing film. The measurement was carried out in an environment of 23℃×50%RH.

The adhesive surface of the adhesive layer used in the above-mentioned surface protection sheet is adhered to the hard-coated surface in a low temperature environment of 0°C for 1 day (left), and then peeled off at a peeling angle of 150° and a peeling speed of 30m/min (high-speed peeling) The potential (peeling charging voltage: kV, absolute value) generated on the surface of the polarizing film is preferably 0.6 kV or less, more preferably 0.5 kV or less, and still more preferably 0.4 kV or less. When the above-mentioned peeling charging voltage exceeds 0.6 kV, it may cause damage to a liquid crystal driver, etc., which is not preferable.

<White color of LCD panel> Use a manual roller to attach the surface protection sheet to the surface of the polarizing film. Then, it was cut into a size of 150 mm × 100 mm, the separation piece was peeled off, and it was bonded to a liquid crystal cell to produce a liquid crystal panel. The panel was left in a low temperature environment of 0° C. for 1 day. After taking it out, immediately place it on a backlight with a brightness of 10,000 cd in an environment of 23°C × 50% RH, and peel the above-mentioned surface protection film from the surface of the polarizing film at a speed of 1m/second to generate static electricity, thereby causing the orientation of the liquid crystal. disorder. The white unevenness was evaluated by visually measuring the recovery time (seconds) of the display failure caused by the orientation failure. The recovery time for bad display is preferably less than 30 seconds. White unevenness was evaluated based on the following criteria. ○: The recovery (disappearance) time is less than 30 seconds ×: The recovery (disappearance) time is more than 30 seconds

According to the above evaluation method, the surface protection sheet produced was evaluated for peeling charging voltage and white unevenness in a low temperature environment of 0° C., and the evaluation results are shown in Table 3.

table 3

From the results in Table 3 above, it can be confirmed that in all the examples, by using an ionic compound that is an onium salt with a melting point of -4°C or less, the peeling charging voltage is 0.6 kV or less, and the white unevenness disappears in a short time, preventing the occurrence of white unevenness. Excellent electrostatic properties.

On the other hand, in all comparative examples, it was confirmed that since ionic compounds with melting points exceeding -4°C were used, the peeling charging voltage in a low-temperature environment exceeded 0.6 kV, and the white unevenness took a long time to disappear, and the antistatic properties were poor. In particular, in Comparative Examples 3 and 4 in which an ionic compound having a melting point of 10° C. or higher was used, it was confirmed that a very high peeling charging voltage was obtained and the antistatic properties were very poor.

1‧‧‧Potentiometer 2‧‧‧Surface protection sheet 3‧‧‧Polarizing film 4‧‧‧Acrylic resin plate 5‧‧‧Fixing table

FIG. 1 is a schematic diagram of a potential measuring unit.

(without)

Claims (4)

An optical component, characterized in that it is protected by a surface protection sheet, and the surface protection sheet has an adhesive layer formed of an adhesive composition on one side of the supporting film; the aforementioned adhesive composition contains an adhesive with a melting point of -4°C or less. onium salt; and a polymer having a glass transition temperature of 0°C or less as a base polymer; the base polymer is a (meth)acrylic polymer, and relative to the base polymer constituting the (meth)acrylic polymer The total amount of monomer components contains 0.1 to 20 mass % of hydroxyl-containing (meth)acrylic monomers; and the adhesive composition contains 0.1 to 10 mass parts of the aforementioned onium salt relative to 100 mass parts of the aforementioned base polymer; And the aforementioned onium salt is at least one selected from the group consisting of nitrogen-containing onium salts, sulfur-containing onium salts and phosphorus-containing onium salts; the aforementioned optical member is a polarizing film including a polarizer, and the thickness of the aforementioned polarizer is Below 8μm. The optical component of claim 1, wherein the adhesive composition contains a compound having an oxidized alkylene group. The optical member of claim 1 or 2, wherein the (meth)acrylic polymer is a (meth)acrylic polymer having a hydroxyl group and a carboxyl group. The optical member according to claim 1 or 2, wherein the surface protection sheet has an antistatic layer on the opposite side to the adhesive layer to be formed on the support film, and the antistatic layer is made of polyaniline and / Or polythiophenes are used as antistatic agents of conductive polymer components. object formation.