JP6636590B2 - Surface protective film, method for producing surface protective film, and optical member - Google Patents

Description

  The present invention relates to a surface protection film for a touch panel, a method for manufacturing the surface protection film, and an optical member mounted on the touch panel.

  The surface protective film generally has a configuration in which a pressure-sensitive adhesive layer is provided on a film-like substrate (support). Such a protective film is adhered to an adherend (protected object) via the above-mentioned pressure-sensitive adhesive layer, and is used for the purpose of protecting the adherend from scratches and dirt during processing, transportation, and the like.

  For example, a touch panel of a liquid crystal display is formed by attaching an optical member such as a polarizing plate or a wavelength plate to a liquid crystal cell via an adhesive layer. In manufacturing such a liquid crystal display panel, the polarizing plate to be bonded to the liquid crystal cell is once manufactured in a roll form, unwound from the roll, and cut into a desired size according to the shape of the liquid crystal cell. . Here, in order to prevent the polarizing plate from being rubbed and damaged by a transport roll or the like in an intermediate step, a measure is taken to attach a surface protective film to one side or both sides (typically, one side) of the polarizing plate.

  Generally, since the surface protection film and the optical member are made of a plastic material, they have high electrical insulation properties and generate static electricity due to friction or peeling. For this reason, static electricity is easily generated even when the surface protective film is peeled off from an optical member such as a polarizing plate, and when a voltage is applied to the liquid crystal while the static electricity remains, the alignment of the liquid crystal molecules is lost, There is also a concern that the panel may be damaged. In addition, the presence of static electricity can be a factor of sucking dust and lowering workability. Under such circumstances, an antistatic treatment is performed on the surface protective film. For example, forming an antistatic layer or applying an antistatic coating as a surface layer (top coat layer, back layer) of the surface protective film. (See Patent Documents 1 and 2).

  In recent years, PEDOT (poly (3,4-ethylenedioxythiophene) / PSS (polystyrenesulfonate) (polythiophene type) is a conductive polymer used to impart an antistatic function to the surface layer of a surface protective film. However, in the case of the above-mentioned water-dispersion type, when stored in a solution state, agglomerates are generated, and a uniform antistatic layer cannot be formed. Further, when an antistatic layer is formed using the conductive polymer, PSS (corresponding to a dopant) is desorbed from PEDOT with the lapse of time, and the surface resistance and the peeling voltage are reduced. There is a possibility that a problem such as an increase (deterioration) of surface resistance due to oxidation deterioration or light deterioration may occur.

  On the other hand, in a capacitive touch panel, when the polarizing plate is installed on the viewing side from the touch sensor, when checking the operation of the touch panel with the protective film stuck to the polarizing plate, the surface of the surface protective film is If the surface resistance value of the layer is too low, the touch panel does not react and the inspection cannot be performed. If the surface resistance value is too high, static electricity is generated, and there is a concern that a problem may occur.

  Further, when the surface protective film becomes unnecessary, after being peeled off from the optical member, a layer having another function (other layer) or the like is provided on the surface of the adherend to which the surface protective film has been attached. There is. Depending on the state of the adherend surface after peeling off the surface protection film, the wettability to other layers may be deteriorated, for example, when the other layers cannot perform the expected functions or the product is defective. If you are concerned. Specifically, when another layer such as a layer having a touch panel function is installed on the surface of the polarizing plate, the layer is provided to protect the surface of the polarizing plate (for example, a polarizing plate having a hard coat layer as a surface layer). After peeling off the surface protection film, when the interlayer filler is applied between the other layer and the polarizing plate surface to provide a transparent layer, the wettability of the polarizing plate surface to the interlayer filler is not sufficient. There is. Therefore, when providing another layer on the surface of the adherend after peeling off the surface protective film, there is a need for the development of a surface protective film that can ensure excellent wettability.

JP 2004-223923 A JP 2008-255332 A

  Accordingly, the present invention has been made in view of the above circumstances, and as a result of intensive research, it has been found that the antistatic property, the stability over time of the peeling voltage can be excellent, the operation of the touch panel can be confirmed, and the adhesion after peeling off the surface protective film. An object of the present invention is to provide a surface protective film for a touch panel which is excellent in wettability to an interlayer filler on a body surface, a method for producing the surface protective film, and an optical member.

  That is, the surface protective film for a touch panel of the present invention includes a substrate having a first surface and a second surface, an antistatic layer provided on the first surface of the substrate, and the second surface of the substrate. Pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition, and the surface protective film for a touch panel, wherein the antistatic layer, polyaniline sulfonic acid as a conductive polymer component, polyester resin as a binder, and as a cross-linking agent Formed from an antistatic agent composition containing an isocyanate-based crosslinking agent, the pressure-sensitive adhesive composition contains a (meth) acrylic polymer, and a polyether compound, and the (meth) acrylic polymer has 100 parts by mass. On the other hand, the polyether compound is contained in an amount of 0.03 to 14 parts by mass.

  In the surface protective film for a touch panel of the present invention, the base material preferably contains polyethylene terephthalate and / or polyethylene naphthalate.

  In the surface protective film for a touch panel of the present invention, it is preferable that the antistatic agent composition further contains a fatty acid amide as a lubricant.

  In the surface protective film for a touch panel of the present invention, the polyether compound is preferably a surfactant.

  The optical member mounted on the touch panel of the present invention is preferably protected by the touch panel surface protection film.

  The method for producing a surface protective film for a touch panel of the present invention includes a step of preparing an aqueous solution containing the antistatic agent composition, and applying and drying the aqueous solution on the first surface of the substrate to form an antistatic layer. And a preparing step.

  The surface protective film of the present invention can form a uniform antistatic layer by forming the antistatic layer from a specific conductive polymer component, a binder, and an antistatic composition containing a crosslinking agent. Excellent workability, furthermore, the antistatic property based on the antistatic layer and the stability over time of the peeling electrostatic voltage are good, the operation of the touch panel can be confirmed, and the pressure-sensitive adhesive layer has a ) By being formed from an adhesive composition containing a specific ratio of an acrylic polymer and a polyether compound, after peeling off a surface protective film attached to an adherend such as a polarizing plate, an interlayer is formed on the same adherend surface. Even when a filler is applied, it is possible to obtain a surface protective film for a touch panel excellent in wettability with respect to an interlayer filler, a method for producing the surface protective film, and an optical member. It has the aspect.

It is a typical sectional view showing an example of 1 composition of a surface protection film for touch panels concerning the present invention. It is a typical sectional view of an example of 1 composition of a touch panel to which the surface protection film for touch panels of the present invention was stuck. It is explanatory drawing which shows the measuring method of a peeling charge voltage.

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

<Overall structure of surface protective film for touch panel>
The surface protective film for a touch panel disclosed herein (hereinafter, sometimes simply referred to as “surface protective film”) is generally referred to as an adhesive sheet, an adhesive tape, an adhesive label, an adhesive film, a surface protective sheet, or the like. A surface protection film that protects the surface of an optical member, particularly when processing or transporting an optical member such as a polarizing plate that is pasted on a touch sensor or glass via an adhesive layer in a liquid crystal display panel through an adhesive layer. It is suitable as. The pressure-sensitive adhesive layer in the surface protective film is typically formed continuously, but is not limited to such a form.For example, the pressure-sensitive adhesive layer is formed in a regular or random pattern such as a dot shape and a stripe shape. It may be an adhesive layer. Further, the surface protective film disclosed herein may be in a roll shape or a single-leaf shape.

  A typical configuration example of the surface protective film disclosed herein is schematically shown in FIGS. The surface protection film 1 includes a substrate (eg, a polyester film) 12, an antistatic layer 11 provided on the first surface 12, and a second surface of the substrate 12 (an opposite side of the antistatic layer 11). And a pressure-sensitive adhesive layer 13 provided on the front surface). The surface protective film 1 uses the pressure-sensitive adhesive layer 13 as an adherend (to be protected) on the touch sensor 32 or the base glass 33 in the liquid crystal display panel (touch panel) 3 via the pressure-sensitive adhesive layer 13. It is used by being attached to an optical member such as the plate 31). Before use (that is, before sticking to the adherend), the surface protective film 1 has the surface of the pressure-sensitive adhesive layer 13 (the surface to be adhered to the adherend) in which at least the pressure-sensitive adhesive layer 13 side is a peeling surface. It may be in a form protected by a liner. Alternatively, even when the surface protection film 1 is wound into a roll, the pressure-sensitive adhesive layer 13 is in contact with the back surface of the base material 12 (the surface of the antistatic layer 11) to protect the surface. Good.

  As shown in FIG. 1, an embodiment in which an antistatic layer 11 is formed directly on the first surface of a base material 12 (without interposing any other layer), and the antistatic layer 11 is exposed on the back surface of the surface protection film 1. (That is, the mode in which the antistatic layer 11 also functions as the top coat layer) is provided with an antistatic layer in which the antistatic layer 11 is provided on the base material 12 as compared with the configuration in which the antistatic layer is provided separately from the top coat layer. A film (and a surface protective film using the film) can be reduced in the number of layers constituting the surface protective film, and thus is advantageous from the viewpoint of improving productivity and the like.

<Substrate>
The surface protective film of the present invention is characterized by having a substrate having a first surface (back surface) and a second surface (surface opposite to the first surface). In the technology disclosed herein, the resin material constituting the base material can be used without any particular limitation. For example, transparency, mechanical strength, heat stability, moisture shielding property, isotropic property, flexibility It is preferable to use one having excellent properties such as properties and dimensional stability. In particular, since the substrate has flexibility, the pressure-sensitive adhesive composition can be applied by a roll coater or the like, and can be wound up in a roll shape, which is useful.

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

  As the substrate, a plastic film made of a transparent thermoplastic resin material can be preferably used. It is a more preferable embodiment to use a polyester film among the plastic films. Here, the polyester film is a film having a polymer material (polyester resin) having a main skeleton based on an ester bond such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), or polybutylene terephthalate as a main resin component. Say. Such a polyester film has preferable characteristics as a base material of a surface protective film, such as excellent optical characteristics and dimensional stability. Among them, it is particularly preferable that the base material contains polyethylene terephthalate and / or polyethylene naphthalate.

  Various additives such as an antioxidant, an ultraviolet absorber, a plasticizer, and a coloring agent (eg, a pigment or a dye) may be added to the resin material constituting the base material, if necessary. On the first surface (the surface on the side where the antistatic layer is provided) of the polyester film, for example, known or commonly used methods such as corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, and application of an undercoat agent Surface treatment may be applied. Such a surface treatment may be, for example, a treatment for increasing the adhesion between the substrate and the antistatic layer. A surface treatment that introduces a polar group such as a hydroxyl group into the surface of the substrate can be preferably employed. Further, the second surface (the surface on the side where the pressure-sensitive adhesive layer is formed) of the substrate may be subjected to the same surface treatment as described above. Such a surface treatment may be a treatment for increasing the adhesion between the film and the pressure-sensitive adhesive layer (the anchoring property of the pressure-sensitive adhesive layer).

  The surface protective film of the present invention has an antistatic function by having an antistatic layer on a substrate, but it is also possible to use a plastic film that has been subjected to antistatic treatment as the substrate. is there. The use of the base material is preferable because charging of the surface protective film itself when peeled off is suppressed. Further, the base material is a plastic film, and by subjecting the plastic film to an antistatic treatment, it is possible to reduce the charge of the surface protection film itself and obtain an excellent antistatic ability on the adherend. The method of imparting the antistatic function is not particularly limited, and a conventionally known method can be used. For example, an antistatic resin or a conductive polymer including an antistatic agent and a resin component, a conductive polymer, or a conductive substance may be used. Examples thereof include a method of applying a conductive resin to be contained, a method of depositing or plating a conductive substance, and a method of kneading an antistatic agent or the like.

  The thickness of the substrate is usually 5 to 200 μm, preferably about 10 to 100 μm. When the thickness of the substrate is within the above range, the workability of laminating to the adherend and the workability of peeling from the adherend are excellent, which is preferable.

<Antistatic layer (top coat layer)>
The surface protective film of the present invention is provided on a substrate having a first surface (back surface) and a second surface (surface opposite to the first surface), and on the first surface (back surface) of the substrate. A surface protective film comprising an antistatic layer and an adhesive layer formed of an adhesive composition on the second surface of the substrate, wherein the antistatic layer has a polyanilinesulfonic acid as a conductive polymer component. And an antistatic composition containing a polyester resin as a binder and an isocyanate-based crosslinking agent as a crosslinking agent. When the surface protective film has an antistatic layer (top coat layer), the antistatic property of the surface protective film and the stability over time of the peeling electrostatic voltage are improved, which is a preferable embodiment.

<Conductive polymer>
The antistatic layer contains polyanilinesulfonic acid as a conductive polymer component. By using the conductive polymer, the antistatic property based on the antistatic layer and the peeling voltage over time can be satisfied. The polyaniline sulfonic acid is “water-soluble”, but can be immobilized in the antistatic layer by using an isocyanate-based cross-linking agent described later, and the water resistance can be improved. By using the aqueous solution containing a water-soluble conductive polymer, an antistatic layer having excellent surface resistance over time is obtained, which is a preferable embodiment. On the other hand, when the conductive polymer used in forming the antistatic layer is “water-dispersible”, when the antistatic layer is formed using the water-dispersible conductive polymer-containing solution, an aggregate is generated. This is not preferable because the composition tends to be easily applied and cannot be uniformly applied, and the surface resistance value over time tends to be extremely poor.

  The amount of the conductive polymer to be used is preferably from 10 to 200 parts by mass, more preferably from 25 to 150 parts by mass, and still more preferably from 40 to 120 parts by mass, based on 100 parts by mass of the binder contained in the antistatic layer. Parts by weight. If the amount of the conductive polymer is too small, the antistatic effect may be reduced.If the amount of the conductive polymer is too large, the adhesion of the antistatic layer to the substrate may be reduced, or the transparency may be reduced. It is not preferable because it may decrease.

The polyanilinesulfonic acid used as the conductive polymer component preferably has a weight average molecular weight (Mw) in terms of polystyrene of 5 × 10 ⁵ or less, more preferably 3 × 10 ⁵ or less. The weight average molecular weight of these conductive polymers is usually preferably 1 × 10 ³ or more, more preferably 5 × 10 ³ or more.

As a method of forming the antistatic layer, a method of applying and drying (or curing) a coating material (antistatic agent composition) for forming an antistatic layer on the first surface of a substrate (support) can be adopted. The conductive polymer component used in the preparation of the coating material includes polyaniline sulfonic acid, a polyester resin as a binder, and an isocyanate-based cross-linking agent as a cross-linking agent as essential components, wherein the essential component is dissolved in water. (A conductive polymer aqueous solution or simply an aqueous solution) can be preferably used. Such a conductive polymer aqueous solution is prepared, for example, by dissolving a conductive polymer having a hydrophilic functional group (which can be synthesized by a method such as copolymerizing a monomer having a hydrophilic functional group in a molecule) in water. can do. Examples of the hydrophilic functional group include a sulfo group, an amino group, an amide group, an imino group, a hydroxyl group, a mercapto group, a hydrazino group, a carboxyl group, a quaternary ammonium group, a sulfate group (—O—SO ₃ H), and phosphorus. Examples thereof include an acid ester group (for example, -O-PO (OH) ₂ ). Such a hydrophilic functional group may form a salt.

  Examples of commercially available polyanilinesulfonic acid aqueous solution include “aqua-PASS” (trade name, manufactured by Mitsubishi Rayon Co., Ltd.).

  The antistatic layer disclosed herein contains polyanilinesulfonic acid (polyaniline type) as an essential component as a conductive polymer component. For example, one or more other antistatic components (conductive polymer) may be used. Other organic conductive materials, inorganic conductive materials, antistatic agents, etc.). In a preferred embodiment, the antistatic layer contains substantially no antistatic component other than the conductive polymer, that is, the antistatic component contained in the antistatic layer is substantially only a conductive polymer. May be more preferably implemented.

  Examples of the organic conductive material include a cationic antistatic agent having a cationic functional group such as a quaternary ammonium salt, a pyridinium salt, a primary amino group, a secondary amino group, and a tertiary amino group; Anionic antistatic agents having an anionic functional group such as salts, phosphonates and phosphate esters; Zwitterionic antistatic agents such as alkyl betaines and derivatives thereof, imidazolines and derivatives thereof, alanines and derivatives thereof; amino alcohols And its derivatives, glycerin and its derivatives, polyethylene glycol and its derivatives, etc .; nonionic antistatic agents; polymerization of the above-mentioned monomers having a cationic, anionic or amphoteric ion conductive group (for example, a quaternary ammonium base) Or an ion conductive polymer obtained by copolymerization; poly Include; thiophene, polyaniline, polypyrrole, polyethylene imine, a conductive polymer such as an allylamine polymer. One of such antistatic agents may be used alone, or two or more thereof may be used in combination.

  As the inorganic conductive material, tin oxide, antimony oxide, indium oxide, cadmium oxide, titanium oxide, zinc oxide, indium, tin, antimony, gold, silver, copper, aluminum, nickel, chromium, titanium, iron, cobalt, Examples thereof include copper iodide, ITO (indium oxide / tin oxide), and ATO (antimony oxide / tin oxide). One kind of such an inorganic conductive substance may be used alone, or two or more kinds may be used in combination.

  Examples of the antistatic agent include a cationic antistatic agent, an anionic antistatic agent, an amphoteric ionic antistatic agent, a nonionic antistatic agent, and a monomer having the cationic, anionic, and amphoteric ionic conductive groups. And an ionic conductive polymer obtained by polymerizing or copolymerizing the above.

<Binder>
The antistatic layer contains a polyester resin as a binder as an essential component. The polyester resin is preferably a resin material containing polyester as a main component (a component that typically accounts for more than 50% by mass, preferably 75% by mass or more, for example, 90% by mass or more). The polyester is typically a polyvalent carboxylic acid having two or more carboxyl groups in one molecule (typically, dicarboxylic acids) and derivatives thereof (anhydrides, esterified products, halogens of the polycarboxylic acids). Compounds) (polyhydric carboxylic acid component) and polyhydric alcohols having two or more hydroxyl groups in one molecule (typically diols). It preferably has a structure in which one or more compounds (polyhydric alcohol components) are condensed.

  Examples of compounds that can be employed as the polycarboxylic acid component include oxalic acid, malonic acid, difluoromalonic acid, alkylmalonic acid, succinic acid, tetrafluorosuccinic acid, alkylsuccinic acid, (±) -malic acid, meso -Tartaric acid, itaconic acid, maleic acid, methyl maleic acid, fumaric acid, methyl fumaric acid, acetylenedicarboxylic acid, glutaric acid, hexafluoroglutaric acid, methyl glutaric acid, glutaconic acid, adipic acid, dithioadipic acid, methyl adipic acid, dimethyl Adipic acid, tetramethyl adipic acid, methylene adipic acid, muconic acid, galactic acid, pimelic acid, suberic acid, perfluorosuberic acid, 3,3,6,6-tetramethylsuberic acid, azelaic acid, sebacic acid, perfluoroacid Sebacic acid, brassic acid, dodecyl dical Aliphatic dicarboxylic acids such as acid, tridecyldicarboxylic acid and tetradecyldicarboxylic acid; cycloalkyldicarboxylic acids (eg, 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid), 1,4- (2- Alicyclic dicarboxylic acids such as norbornene) dicarboxylic acid, 5-norbornene-2,3-dicarboxylic acid (hymic acid), adamantane dicarboxylic acid and spiroheptane dicarboxylic acid; phthalic acid, isophthalic acid, dithioisophthalic acid, methyl isophthalic acid, Dimethyl isophthalic acid, chloro isophthalic acid, dichloro isophthalic acid, terephthalic acid, methyl terephthalic acid, dimethyl terephthalic acid, chloroterephthalic acid, bromoterephthalic acid, naphthalenedicarboxylic acid, oxofluorene carboxylic acid, anthracene dical Bonic acid, biphenyldicarboxylic acid, biphenylenedicarboxylic acid, dimethylbiphenylenedicarboxylic acid, 4,4 ″ -p-terphenylenedicarboxylic acid, 4,4 ″ -p-quarelphenyldicarboxylic acid, bibenzyldicarboxylic acid, azobenzenedicarboxylic acid, Homophthalic acid, phenylene diacetic acid, phenylenedipropionic acid, naphthalenedicarboxylic acid, naphthalenedipropionic acid, biphenyl diacetic acid, biphenyl dipropionic acid, 3,3 ′-[4,4 ′-(methylenedi-p-biphenylene) dipropion Aromatic dicarboxylic acids such as acid, 4,4′-bibenzyldiacetic acid, 3,3 ′ (4,4′-bibenzyl) dipropionic acid, oxydi-p-phenylenediacetic acid; any of the above-mentioned polyvalent carboxylic acids Acid anhydrides of any of the above polycarboxylic acids (Eg alkyl esters. It may be a monoester, diester, or the like. ); Acid halides corresponding to any of the above-mentioned polycarboxylic acids (for example, dicarboxylic acid chloride); and the like.

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

  On the other hand, examples of compounds that can be employed as the polyhydric alcohol component include ethylene glycol, propylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, and 1,4-butanediol. , Neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 3-methylpentanediol, diethylene glycol, 1,4-cyclohexanedimethanol, 3-methyl-1,5-pentanediol, 2-methyl- Diols such as 1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, xylylene glycol, hydrogenated bisphenol A and bisphenol A Is mentioned. Other examples include alkylene oxide adducts of these compounds (eg, ethylene oxide adducts, propylene oxide adducts, and the like).

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

  As the polyester resin, a commercial product “Vylonal” manufactured by Toyobo Co., Ltd. or the like can be used.

  The antistatic layer (top coat layer) may be a resin other than a polyester resin (for example, acrylic) as a binder as long as the performance (for example, performance such as antistatic properties) of the surface protective film disclosed herein is not significantly impaired. Resin, acrylic resin, acrylic styrene resin, acrylic silicone resin, silicone resin, polysilazane resin, polyurethane resin, fluororesin, polyolefin resin, etc.). One preferred embodiment of the technology disclosed herein is a case where the binder of the antistatic layer substantially consists of only a polyester resin. For example, an antistatic layer in which the ratio of the polyester resin to the binder is 98 to 100% by mass is preferable. The proportion of the binder in the entire antistatic layer can be, for example, 50 to 95% by mass, and is usually preferably 60 to 90% by mass.

<Lubricant>
In a preferred embodiment, the antistatic layer (topcoat layer) in the technology disclosed herein uses a fatty acid amide as a lubricant. By using a fatty acid amide as a lubricant, a further release treatment (for example, a treatment of applying a known release treatment agent such as a silicone-based release agent or a long-chain alkyl-based release agent and drying) on the surface of the antistatic layer. Even in a mode in which the antistatic layer is not applied, an antistatic layer (top coat layer) that achieves both sufficient slipperiness and print adhesion can be obtained, which is a preferable mode. As described above, the embodiment in which the surface of the antistatic layer is not further subjected to the release treatment can prevent the whitening (for example, the whitening due to storage under heating and humidification conditions) caused by the release treatment agent beforehand. It is preferred in that respect. It is also advantageous from the viewpoint of solvent resistance.

  Specific examples of the fatty acid amide include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, hydroxystearic acid amide, oleic acid amide, erucic acid amide, N-oleylpartic acid amide, N-stearylstearic acid Amide, N-stearyl oleamide, N-oleyl stearamide, N-stearyl erucamide, methylol stearamide, methylene bis stearamide, ethylene biscapric amide, ethylene bis lauric amide, ethylene bis stearic acid Amide, ethylenebishydroxystearic acid amide, ethylenebisbehenic acid amide, hexamethylenebisstearic acid amide, hexamethylenebisbehenic acid amide, hexamethylenehydroxystearic acid amide Amide, N, N'-distearyl adipamide, N, N'-distearyl sebacic amide, ethylenebisoleic amide, ethylenebiserucamide, hexamethylenebisoleic amide, N, N'-dioleyl Adipic amide, N, N'-dioleyl sebacic amide, m-xylylenebisstearic amide, m-xylylenebishydroxystearic amide, N, N'-stearylisophthalic amide, and the like. One of these lubricants may be used alone, or two or more thereof may be used in combination.

  The proportion of the lubricant in the whole antistatic layer can be 1 to 50% by mass, and is usually suitably 5 to 40% by mass. If the content ratio of the lubricant is too small, the slip property tends to decrease. If the content ratio of the lubricant is too large, the print adhesion may decrease.

  The technology disclosed herein can be implemented in a mode in which the antistatic layer (top coat layer) contains another lubricant in addition to the fatty acid amide, as long as the application effect is not significantly impaired. Examples of such other lubricants include various waxes such as petroleum wax (such as paraffin wax), mineral wax (such as montan wax), higher fatty acid (such as cerotic acid), and neutral fat (such as palmitic acid triglyceride). Can be Alternatively, in addition to the wax, a general silicone-based lubricant, a fluorine-based lubricant, or the like may be additionally contained. The technology disclosed herein can be preferably implemented in a mode that does not substantially contain such a silicone-based lubricant, a fluorine-based lubricant, or the like. However, as long as the application effect of the technology disclosed herein is not significantly impaired, a silicone compound used for a purpose other than the lubricant (for example, as a defoaming agent for a coating material for forming an antistatic layer described later) is used. It does not exclude inclusion.

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

  In a preferred embodiment, a blocked isocyanate-based crosslinking agent that is stable even in an aqueous solution is used as the isocyanate-based crosslinking agent. Specific examples of the blocked isocyanate-based cross-linking agent include an isocyanate-based cross-linking agent that can be used in preparing a general pressure-sensitive adhesive layer or an antistatic layer (a top coat layer) (for example, used in a pressure-sensitive adhesive layer described later). Alcohols, phenols, thiophenols, amines, imides, oximes, lactams, active methylene compounds, mercaptans, imines, ureas, diaryl compounds And those blocked with sodium bisulfite or the like can be used.

  The antistatic layer in the technology disclosed herein is, if necessary, other antistatic components, antioxidants, colorants (pigments, dyes, etc.), fluidity modifiers (thixotropic agents, thickeners, etc.), It may contain additives such as a film-forming aid, a surfactant (such as an antifoaming agent), and a preservative.

<Formation of antistatic layer>
The antistatic layer (topcoat layer) is a liquid composition (an antistatic layer forming agent) in which essential components such as the conductive polymer component and additives used as necessary are dissolved in a suitable solvent (such as water). Of a coating material and an antistatic agent composition) to a substrate. For example, a method of applying the coating material on the first surface of the base material, drying the coating material, and performing a curing treatment (heat treatment, ultraviolet treatment, or the like) as necessary can be preferably employed. The NV (nonvolatile content) of the coating material can be, for example, 5% by mass or less (typically 0.05 to 5% by mass), and is usually 1% by mass or less (typically 0.10 to 10% by mass). 1% by mass). When forming an antistatic layer having a small thickness, the NV of the coating material is preferably, for example, 0.05 to 0.50% by mass (for example, 0.10 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 for forming the antistatic layer is preferably a solvent capable of stably dissolving the components forming the antistatic layer. Such a solvent may be an organic solvent, water, or a mixture thereof. Examples of the organic solvent include esters such as ethyl acetate; ketones such as methyl ethyl ketone, acetone and cyclohexanone; cyclic ethers such as tetrahydrofuran (THF) and dioxane; aliphatic or alicyclic such as n-hexane and cyclohexane. Hydrocarbons; aromatic hydrocarbons such as toluene and xylene; aliphatic or alicyclic alcohols such as methanol, ethanol, n-propanol, isopropanol and cyclohexanol; alkylene glycol monoalkyl ethers (eg, ethylene glycol monomethyl ether) , Ethylene glycol monoethyl ether), glycol ethers such as dialkylene glycol monoalkyl ether, etc .; In a preferred embodiment, the solvent of the coating material is water or a mixed solvent containing water as a main component (for example, a mixed solvent of water and ethanol).

<Properties of antistatic layer>
The thickness of the antistatic layer in the technology disclosed herein is typically from 3 to 500 nm, preferably from 3 to 100 nm, and more preferably from 3 to 60 nm. If the thickness of the antistatic layer is too small, it is difficult to form the antistatic layer uniformly (for example, the thickness of the antistatic layer varies widely depending on the location), and therefore, the appearance of the surface protective film Unevenness may easily occur. On the other hand, if it is too thick, it may affect the properties (optical properties, dimensional stability, etc.) of the base material.

In a preferred embodiment of the surface protective film disclosed herein, the surface resistance (Ω / □) measured on the surface of the antistatic layer is preferably 1.0 × 10 ⁷ or more and 1.0 × 10 ^11. Is less than 1.0 × 10 ⁸ or more and less than 5.0 × 10 ¹⁰ , and still more preferably 1.0 × 10 ⁹ or more and less than 2.0 × 10 ¹⁰ . The surface protective film having a surface resistance value within the above range can be suitably used as a surface protective film used in, for example, a process or a process of transporting an article that does not like static electricity such as a liquid crystal cell or a semiconductor device. Further, the surface protective film having a surface resistance value within the above range, the polarizing plate is mounted above the touch panel sensor, even in a state where the surface protective film is stuck on the polarizing plate, it is possible to confirm the operation. Can be useful. The surface resistance can be calculated from the surface resistance measured under an atmosphere of 23 ° C. and 50% RH using a commercially available insulation resistance measuring device.

  The surface protective film disclosed herein preferably has a property that the back surface (the surface of the antistatic layer) can be easily printed with an aqueous ink or an oil-based ink (for example, using an oil-based marking pen). Such a surface protective film is used for processing or transporting an adherend (for example, an optical member such as a polarizing plate) performed in a state where the surface protective film is stuck, and identifies the identification number of the adherend to be protected. It is suitable for displaying on the surface protection film for display. Therefore, it is preferable that the surface protective film has excellent printability. For example, it is preferable that the solvent has a high printability with respect to an oil-based ink of a type containing an alcohol and containing a pigment. Further, it is preferable that the printed ink is difficult to be removed by rubbing or transfer (that is, excellent in printing adhesion). The surface protective film disclosed herein may also have a solvent resistance that does not cause a noticeable change in appearance even when the print is wiped with alcohol (for example, ethyl alcohol) when correcting or erasing the print. preferable.

  The surface protective film disclosed herein can be implemented in a mode that further includes another layer in addition to the substrate, the pressure-sensitive adhesive layer, and the antistatic layer. The arrangement of the “other layer” is, for example, between the first surface (back surface) of the substrate and the antistatic layer, between the second surface (front surface) of the substrate and the pressure-sensitive adhesive layer. The layer disposed between the back surface of the substrate and the antistatic layer can be, for example, a layer containing an antistatic component (the above-described antistatic layer). The layer disposed between the front surface of the base material and the pressure-sensitive adhesive layer may be, for example, an undercoat layer (anchor layer) for enhancing the anchoring property of the pressure-sensitive adhesive layer to the second surface, an antistatic layer, or the like. The surface protection film may have a configuration in which an antistatic layer is disposed on the front surface of the base material, an anchor layer is disposed on the antistatic layer, and an adhesive layer is disposed thereon.

<Adhesive layer>
The surface protective film of the present invention has the pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive composition, the pressure-sensitive adhesive composition, (meth) acrylic polymer, and poly An ether compound is contained, and the polyether compound is contained in an amount of 0.03 to 14 parts by mass with respect to 100 parts by mass of the (meth) acrylic polymer.

  The (meth) acryl-based polymer may be a (meth) acryl-based monomer having an alkyl group having 1 to 14 carbon atoms as a raw material monomer constituting the polymer. One or more of the (meth) acrylic monomers can be used as a main component. By using the (meth) acrylic monomer having an alkyl group having 1 to 14 carbon atoms, it is easy to control the adhesive strength to an adherend (protected body) to be low, and it is easy to achieve light peelability and re-peelability. A surface protective film having excellent properties can be obtained. In the present invention, the (meth) acrylic polymer refers to an acrylic polymer and / or a methacrylic polymer, and the (meth) acrylate refers to an acrylate and / or a methacrylate.

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

  Among them, the surface protective film of the present invention includes hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl C6-14 carbon atoms such as (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-dodecyl (meth) acrylate, n-tridecyl (meth) acrylate and n-tetradecyl (meth) acrylate (Meth) acrylic monomers having an alkyl group are preferred. In particular, by using a (meth) acrylic monomer having an alkyl group having 6 to 14 carbon atoms, the adhesion to the adherend can be easily controlled to be low, and the removability is excellent.

  In particular, it is preferable that the (meth) acrylic monomer having an alkyl group having 1 to 14 carbon atoms has a (meth) acrylic monomer content of 50% by mass or more based on 100% by mass of the total amount of the monomer components constituting the (meth) acrylic polymer. , More preferably 60% by mass or more, further preferably 70% by mass or more, and most preferably 80 to 93% by mass. If the amount is less than 50% by mass, the wettability of the pressure-sensitive adhesive composition and the cohesive strength of the pressure-sensitive adhesive layer become poor, which is not preferable.

  In the pressure-sensitive adhesive composition of the present invention, it is preferable that the (meth) acrylic polymer contains a (meth) acrylic monomer having a hydroxyl group as a raw material monomer. As the (meth) acrylic monomer having a hydroxyl group, one or more kinds can be used as a main component.

  By using the (meth) acrylic monomer having a hydroxyl group, it is easy to control the crosslinking of the pressure-sensitive adhesive composition, and it is easy to control the balance between the improvement of wettability by flow and the reduction of pressure-sensitive adhesive force in peeling. Become. Furthermore, unlike a carboxyl group or a sulfonate group, which can generally act as a crosslinking site, a hydroxyl group has a moderate interaction when an ionic compound or the like is used as an antistatic component, so that it has an appropriate antistatic property. In terms of surface, it can be suitably used.

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

  It is preferable that the (meth) acrylic monomer having a hydroxyl group is contained in an amount of 15 parts by mass or less, based on 100 parts by mass of the (meth) acrylic monomer having an alkyl group having 1 to 14 carbon atoms, and more preferably. Is 1 to 13 parts by mass, more preferably 2 to 11 parts by mass, and most preferably 3.5 to 10 parts by mass. It is preferable for it to be in the above-mentioned range because the balance between the wettability of the pressure-sensitive adhesive composition and the cohesive force of the obtained pressure-sensitive adhesive layer can be easily controlled.

  Further, as another polymerizable monomer component, the Tg is set to 0 ° C. or lower (usually −100 ° C. or higher) so that the glass transition temperature and the peeling of the (meth) acrylic polymer can be improved because the adhesion performance can be easily balanced. A polymerizable monomer or the like for adjusting the properties can be used as long as the effects of the present invention are not impaired.

  Examples of the (meth) acrylic monomer having an alkyl group having 1 to 14 carbon atoms used in the (meth) acrylic polymer, and other polymerizable monomers other than the (meth) acrylic monomer having a hydroxyl group include: And a (meth) acrylic monomer having a carboxyl group.

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

  The (meth) acrylic monomer having a carboxyl group is preferably 5 parts by mass or less, and more preferably 3 parts by mass, based on 100 parts by mass of the (meth) acrylic monomer having an alkyl group having 1 to 14 carbon atoms. Parts by mass or less, more preferably 1 part by mass or less, and most preferably 0.005 to 0.5 part by mass. When the amount exceeds 5 parts by mass, a large number of acid functional groups such as a carboxyl group having a large polar effect are present. For example, when an ionic compound is blended as an antistatic component, the ionic compound has an acid functional group such as a carboxyl group. The interaction of the groups is not preferable because ionic conduction is hindered, conductivity efficiency is reduced, and sufficient antistatic property may not be obtained.

  Furthermore, the (meth) acryl-based monomer having an alkyl group having 1 to 14 carbon atoms, the (meth) acryl-based monomer having a hydroxyl group, and the (meth) having a carboxyl group used in the (meth) acryl-based polymer Any other polymerizable monomer other than the acrylic monomer can be used without any particular limitation as long as the properties of the present invention are not impaired. For example, components for improving cohesion and heat resistance, such as cyano group-containing monomers, vinyl ester monomers, and aromatic vinyl monomers; amide group-containing monomers, imide group-containing monomers, amino group-containing monomers, epoxy group-containing monomers, and N-acryloyl morpholine In addition, a component having a functional group that functions as a crosslinking base point, such as a vinyl ether monomer, for improving the adhesive strength can be used as appropriate. These polymerizable monomers may be used alone or as a mixture of two or more.

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

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

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

  Examples of the amide group-containing monomer include acrylamide, methacrylamide, diethylacrylamide, N-vinylpyrrolidone, N, N-dimethylacrylamide, N, N-dimethylmethacrylamide, N, N-diethylacrylamide, N, N-diethylmethacryl Examples include amide, N, N'-methylenebisacrylamide, N, N-dimethylaminopropylacrylamide, N, N-dimethylaminopropylmethacrylamide, diacetoneacrylamide and the like.

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

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

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

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

  In the present invention, other polymerizable monomers other than a (meth) acrylic monomer having an alkyl group having 1 to 14 carbon atoms, a (meth) acrylic monomer having a hydroxyl group, and a (meth) acrylic monomer having a carboxyl group are The amount is preferably 0 to 20 parts by mass, more preferably 0 to 10 parts by mass, based on 100 parts by mass of the (meth) acrylic monomer having an alkyl group having 1 to 14 carbon atoms. By using the other polymerizable monomer within the above range, when using an ionic compound as an antistatic agent, appropriately adjusting good interaction with the ionic compound, and good removability. Can be.

  The weight average molecular weight (Mw) of the (meth) acrylic polymer is preferably 100,000 to 5,000,000, more preferably 200,000 to 4,000,000, and further preferably 300,000 to 3,000,000. When the weight average molecular weight is smaller than 100,000, adhesive force tends to remain due to a decrease in the cohesive force of the pressure-sensitive adhesive layer. On the other hand, when the weight average molecular weight exceeds 5,000,000, the fluidity of the polymer decreases, the wettability to an adherend (for example, a polarizing plate) becomes insufficient, and the adherend and the pressure-sensitive adhesive layer of the surface protective film become It tends to cause blistering that occurs during The weight average molecular weight refers to a value obtained by measurement by GPC (gel permeation chromatography).

  Further, the glass transition temperature (Tg) of the (meth) acrylic polymer is preferably 0 ° C or lower, more preferably -10 ° C or lower (usually -100 ° C or higher). When the glass transition temperature is higher than 0 ° C., the polymer is less likely to flow, for example, insufficient wetting to the polarizing plate, and tends to cause blisters generated between the polarizing plate and the pressure-sensitive adhesive layer of the surface protective film. There is. In particular, when the glass transition temperature is -61 ° C or lower, a pressure-sensitive adhesive layer excellent in wettability to a polarizing plate and light peelability is easily obtained. The glass transition temperature of the (meth) acrylic polymer can be adjusted within the above range by appropriately changing the monomer components and the composition ratio used.

  The method for polymerizing the (meth) acrylic polymer is not particularly limited, and can be polymerized by a known method such as solution polymerization, emulsion polymerization, bulk polymerization, or suspension polymerization. Solution polymerization is a more preferred embodiment from the viewpoint of characteristics such as low contamination of the adherend (protected body). Further, the obtained polymer may be any of a random copolymer, a block copolymer, an alternating copolymer, a graft copolymer and the like.

  The solution polymerization method is not particularly limited, for example, a method of dissolving the monomer component, a polymerization initiator and the like in a solvent, heating and polymerizing, and obtaining an acrylic polymer solution containing an acrylic polymer. .

  As a solvent used in the solution polymerization method, various general solvents can be used. Examples of such a solvent (polymerization solvent) include aromatic hydrocarbons such as toluene, benzene, and xylene; esters such as ethyl acetate and n-butyl acetate; and aliphatic hydrocarbons such as n-hexane and n-heptane. Hydrogen; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; and organic solvents such as ketones such as methyl ethyl ketone and methyl isobutyl ketone. The solvents can be used alone or in combination of two or more.

  The polymerization initiator is not particularly limited, and examples thereof include a peroxide-based polymerization initiator and an azo-based polymerization initiator. Examples of the peroxide-based polymerization initiator are not particularly limited, and include, for example, peroxycarbonate, ketone peroxide, peroxyketal, hydroperoxide, dialkyl peroxide, diacyl peroxide, peroxyester, and the like. More specifically, benzoyl peroxide, t-butyl hydroperoxide, di-t-butyl peroxide, t-butylperoxybenzoate, dicumyl peroxide, 1,1-bis (t-butylperoxy)- Examples include 3,3,5-trimethylcyclohexane and 1,1-bis (t-butylperoxy) cyclododecane. The azo-based polymerization initiator is not particularly limited. For example, 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, 2,2'-azobis (2 , 4-dimethylvaleronitrile), 2,2'-azobis (2-methylpropionic acid) dimethyl, 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), 1,1'-azobis (cyclohexane -1-carbonitrile), 2,2'-azobis (2,4,4-trimethylpentane), 4,4'-azobis-4-cyanovaleric acid, 2,2'-azobis (2-amidinopropane) dihydro Chloride, 2,2'-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis (2-methylprop Amidine) disulfate, 2,2'-azobis (N, N'-dimethyleneisobutylamidine) hydrochloride, 2,2'-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate And the like. The polymerization initiators can be used alone or in combination of two or more.

  The blending ratio of the polymerization initiator is not particularly limited, but is preferably, for example, 0.01 to 5 parts by mass, more preferably, to the total amount of monomer components (100 parts by mass) constituting the (meth) acrylic polymer. Is 0.05 to 3 parts by mass.

  In the solution polymerization method, the heating temperature at the time of heating and polymerizing is not particularly limited, and for example, 50 to 80 ° C. The heating time is not particularly limited, but may be, for example, 1 to 24 hours.

<Polyether compound>
Preferably, the pressure-sensitive adhesive composition contains a polyether compound, and the polyether compound is a surfactant. The pressure-sensitive adhesive composition, by blending the polyether compound in a specific ratio, it is possible to impart a suitable antistatic property, further, wetting to the interlayer filler on the adherend surface after peeling the surface protective film The property can be secured and is useful.

  Specific examples of the polyether compound include, for example, polyoxyalkylene alkylamine, polyoxyalkylene diamine, polyoxyalkylene fatty acid ester, polyoxyalkylene sorbitan fatty acid ester, polyoxyalkylene alkylphenyl ether, polyoxyalkylene alkyl ether, and polyoxyalkylene alkyl ether. Nonionic surfactants such as oxyalkylene alkyl allyl ether and polyoxyalkylene alkyl phenyl allyl ether; polyoxyalkylene alkyl ether sulfate, polyoxyalkylene alkyl ether phosphate and polyoxyalkylene alkyl phenyl ether sulfate And anionic surfactants such as polyoxyalkylene alkylphenyl ether phosphate salts; Cationic surfactants and amphoteric surfactants having a xyalkylene chain (polyalkylene oxide chain), polyether compounds having a polyoxyalkylene chain (and derivatives thereof), acrylic compounds having a polyoxyalkylene chain ( And its derivatives). The polyether compounds may be used alone or in combination of two or more.

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

  Further, specific examples of the acrylic compound having a polyoxyalkylene chain include a (meth) acrylate polymer having an oxyalkylene group. As the oxyalkylene group, the addition mole number of the oxyalkylene unit is preferably from 1 to 50, more preferably from 2 to 30, from the viewpoint of coordination of the ionic compound when an ionic compound is blended as an antistatic component. Preferably, 2-20 are more preferable. Moreover, the terminal of the oxyalkylene chain may be substituted with a hydroxyl group, an alkyl group, a phenyl group, or the like.

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

  In addition, other monomer units (components) other than the alkylene oxide (meth) acrylate may be used as the monomer units (components). Specific examples of other monomer components include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, and isobutyl (meth) acrylate. , Hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate Acrylate and / or methacrylate having an alkyl group having 1 to 14 carbon atoms, such as isodecyl (meth) acrylate, n-dodecyl (meth) acrylate, n-tridecyl (meth) acrylate, and n-tetradecyl (meth) acrylate. Door and the like.

  Further, other monomer components other than the alkylene oxide (meth) acrylate include (meth) acrylates containing carboxyl groups, (meth) acrylates containing phosphoric acid groups, (meth) acrylates containing cyano groups, vinyl esters, and aromatic vinyl compounds. Acid anhydride group-containing (meth) acrylate, hydroxyl group-containing (meth) acrylate, amide group-containing (meth) acrylate, amino group-containing (meth) acrylate, epoxy group-containing (meth) acrylate, N-acryloylmorpholine, vinyl ethers Etc. can be used as appropriate.

  In a more preferred embodiment, the polyether compound is a compound having a (poly) ethylene oxide chain at least in part. By blending the (poly) ethylene oxide chain-containing compound, the compatibility between the base polymer (meth) acrylic polymer and the antistatic component is improved, bleeding to the adherend is suitably suppressed, and low contamination is achieved. A pressure-sensitive adhesive composition is obtained. In particular, when a block copolymer of PPG-PEG-PPG is used, a pressure-sensitive adhesive excellent in low contamination can be obtained. As the polyethylene oxide chain-containing compound, the weight of the (poly) ethylene oxide chain in the entire polyether compound is preferably from 5 to 90% by mass, more preferably from 5 to 85% by mass, and still more preferably from 5 to 80% by mass. %, Most preferably from 5 to 75% by weight.

  Further, specific examples of the case where the polyether compound is a surfactant include, for example, an anionic reactive surfactant having a (meth) acryloyl group or an allyl group, a nonionic reactive surfactant, and a cationic surfactant. And reactive surfactants.

  Examples of the anionic reactive surfactant include those represented by Formulas (A1) to (A10).

［式（Ａ１）中のＲ_１は水素またはメチル基を表し、Ｒ_２は炭素数１から３０の炭化水素基またはアシル基を表し、Ｘはアニオン性親水基を表し、Ｒ_３およびＲ_４は同一または異なって、炭素数１から６のアルキレン基を表し、平均付加モル数ｍおよびｎは０〜４０、ただし（ｍ＋ｎ）は３〜４０の数を表す。］。

[In the formula (A1), R ₁ represents hydrogen or a methyl group, R ₂ represents a hydrocarbon group having 1 to 30 carbon atoms or an acyl group, X represents an anionic hydrophilic group, and R ₃ and R ₄ represent Same or different, represents an alkylene group having 1 to 6 carbon atoms, and the average number of added moles m and n is 0 to 40, where (m + n) represents a number of 3 to 40. ].

［式（Ａ２）中のＲ_１は水素またはメチル基を表し、Ｒ_２およびＲ_７は同一または異なって、炭素数１から６のアルキレン基を表し、Ｒ_３およびＲ_５は同一または異なって、水素またはアルキル基を表し、Ｒ_４およびＲ_６は同一または異なって、水素、アルキル基、ベンジル基またはスチレン基を表し、Ｘはアニオン性親水基を表し、平均付加モル数ｍおよびｎは０〜４０、ただし（ｍ＋ｎ）は３〜４０の数を表す。］。

[In formula (A2), R ₁ represents hydrogen or a methyl group, R ₂ and R ₇ are the same or different, and represent an alkylene group having 1 to 6 carbon atoms, and R ₃ and R ₅ are the same or different, R ₄ and R ₆ are the same or different and each represents hydrogen, an alkyl group, a benzyl group or a styrene group; X represents an anionic hydrophilic group; 40, where (m + n) represents a number of 3 to 40. ].

［式（Ａ３）中のＲ_１は水素またはメチル基を表し、Ｒ_２は炭素数１から６のアルキレン基を表し、Ｘはアニオン性親水基を表し、平均付加モル数ｎは３〜４０の数を表す。］。

[In the formula (A3), R ₁ represents hydrogen or a methyl group, R ₂ represents an alkylene group having 1 to 6 carbon atoms, X represents an anionic hydrophilic group, and the average number of added moles n is 3 to 40. Represents a number. ].

［式（Ａ４）中のＲ_１は水素またはメチル基を表し、Ｒ_２は炭素数１から３０の炭化水素基またはアシル基を表し、Ｒ_３およびＲ_４は同一または異なって、炭素数１から６のアルキレン基を表し、Ｘはアニオン性親水基を表し、平均付加モル数ｍおよびｎは０〜４０、ただし（ｍ＋ｎ）は３〜４０の数を表す。］。

[In the formula (A4), R ₁ represents hydrogen or a methyl group, R ₂ represents a hydrocarbon group or an acyl group having 1 to 30 carbon atoms, and R ₃ and R ₄ are the same or different and have 1 to 30 carbon atoms. 6 represents an alkylene group, X represents an anionic hydrophilic group, and the average number of added moles m and n are 0 to 40, where (m + n) represents a number of 3 to 40. ].

［式（Ａ５）中のＲ_１は炭化水素基、アミノ基、カルボン酸残基を表し、Ｒ_２は炭素数１から６のアルキレン基を表し、Ｘはアニオン性親水基を表し、平均付加モル数ｎは３〜４０の整数を表す。］。

[In formula (A5), R ₁ represents a hydrocarbon group, an amino group, or a carboxylic acid residue; R ₂ represents an alkylene group having 1 to 6 carbon atoms; X represents an anionic hydrophilic group; The number n represents an integer of 3 to 40. ].

［式（Ａ６）中のＲ_１は炭素数１から３０の炭化水素基、Ｒ_２は水素または炭素数１から３０の炭化水素基を表し、Ｒ_３は水素またはプロペニル基を表し、Ｒ_４は炭素数１から６のアルキレン基を表し、Ｘはアニオン性親水基を表し、平均付加モル数ｎは３〜４０の数を表す。］。

[In the formula (A6), R ₁ represents a hydrocarbon group having 1 to 30 carbon atoms, R ₂ represents hydrogen or a hydrocarbon group having 1 to 30 carbon atoms, R ₃ represents hydrogen or a propenyl group, and R ₄ represents X represents an alkylene group having 1 to 6 carbon atoms, X represents an anionic hydrophilic group, and the average number of added moles n represents a number of 3 to 40. ].

［式（Ａ７）中のＲ_１は水素またはメチル基を表し、Ｒ_２およびＲ_４は同一または異なって、炭素数１から６のアルキレン基を表し、Ｒ_３は炭素数１から３０の炭化水素基を表し、Ｍは水素、アルカリ金属、アンモニウム基、またはアルカノールアンモニウム基を表し、平均付加モル数ｍおよびｎは０〜４０、ただし（ｍ＋ｎ）は３〜４０の数を表す。］。

[In formula (A7), R ₁ represents hydrogen or a methyl group, R ₂ and R ₄ are the same or different and represent an alkylene group having 1 to 6 carbon atoms, and R ₃ represents a hydrocarbon having 1 to 30 carbon atoms. Represents a group, M represents hydrogen, an alkali metal, an ammonium group, or an alkanolammonium group, and the average number of moles m and n represents 0 to 40, where (m + n) represents a number of 3 to 40. ].

［式（Ａ８）中のＲ_１およびＲ_５は同一または異なって、水素またはメチル基を表し、Ｒ_２およびＲ_４は同一または異なって、炭素数１から６のアルキレン基を表し、Ｒ_３は炭素数１から３０の炭化水素基を表し、Ｍは水素、アルカリ金属、アンモニウム基、またはアルカノールアンモニウム基を表し、平均付加モル数ｍおよびｎは０〜４０、ただし（ｍ＋ｎ）は３〜４０の数を表す。］

[In formula (A8), R ₁ and R ₅ are the same or different and represent hydrogen or a methyl group, R ₂ and R ₄ are the same or different and represent an alkylene group having 1 to 6 carbon atoms, and R ₃ represents Represents a hydrocarbon group having 1 to 30 carbon atoms, M represents hydrogen, an alkali metal, an ammonium group, or an alkanol ammonium group, and the average number of moles m and n is 0 to 40, provided that (m + n) is 3 to 40; Represents a number. ]

［式（Ａ９）中のＲ_１は炭素数１から６のアルキレン基を表し、Ｒ_２は炭素数１から３０の炭化水素基を表し、Ｍは水素、アルカリ金属、アンモニウム基、またはアルカノールアンモニウム基を表し、平均付加モル数ｎは３〜４０の数を表す。］

[In formula (A9), R ₁ represents an alkylene group having 1 to 6 carbon atoms, R ₂ represents a hydrocarbon group having 1 to 30 carbon atoms, and M represents hydrogen, an alkali metal, an ammonium group, or an alkanol ammonium group. And the average number of added moles n represents a number of 3 to 40. ]

［式（Ａ１０）中のＲ_１、Ｒ_２、およびＲ_３は同一または異なって、水素またはメチル基を表し、Ｒ_４は炭素数０から３０の炭化水素基（炭素数０の場合はＲ_４がないことを示す）を表し、Ｒ_５およびＲ_６は同一または異なって、炭素数１から６のアルキレン基を表し、Ｘはアニオン性親水基を表し、平均付加モル数ｍおよびｎは０〜４０、ただし（ｍ＋ｎ）は３〜４０の数を表す。］。

[In the formula (A10), R ₁ , R ₂ and R ₃ are the same or different and represent hydrogen or a methyl group, and R ₄ is a hydrocarbon group having 0 to 30 carbon atoms (in the case of 0 carbon atoms, R ₄ Wherein R ₅ and R ₆ are the same or different and represent an alkylene group having 1 to 6 carbon atoms, X represents an anionic hydrophilic group, and the average number of moles m and n are 0 to 0. 40, where (m + n) represents a number of 3 to 40. ].

  X in the formulas (A1) to (A6) and (A10) represents an anionic hydrophilic group. Examples of the anionic hydrophilic group include those represented by the following formulas (a1) to (a2).

［式（ａ１）中のＭ_１は水素、アルカリ金属、アンモニウム基、またはアルカノールアンモニウム基を表す。］

[M ₁ in the formula (a1) represents hydrogen, an alkali metal, an ammonium group, or an alkanol ammonium group. ]

［式（ａ２）中のＭ_２およびＭ_３は同一または異なって、水素、アルカリ金属、アンモニウム基、またはアルカノールアンモニウム基を表す。］

[M ₂ and M ₃ in the formula (a2) are the same or different and each represents hydrogen, an alkali metal, an ammonium group, or an alkanol ammonium group. ]

  Examples of the nonionic reactive surfactant include those represented by formulas (N1) to (N6).

［式（Ｎ１）中のＲ_１は水素またはメチル基を表し、Ｒ_２は炭素数１から３０の炭化水素基またはアシル基を表し、Ｒ_３およびＲ_４は同一または異なって、炭素数１から６のアルキレン基を表し、平均付加モル数ｍおよびｎは０〜４０、ただし（ｍ＋ｎ）は３〜４０の数を表す。］

[In the formula (N1), R ₁ represents hydrogen or a methyl group, R ₂ represents a hydrocarbon group or an acyl group having 1 to 30 carbon atoms, and R ₃ and R ₄ are the same or different and have a carbon number of 1 to 30; 6 represents an alkylene group, and the average number of added moles m and n is 0 to 40, provided that (m + n) represents a number of 3 to 40. ]

［式（Ｎ２）中のＲ_１は水素またはメチル基を表し、Ｒ_２、Ｒ_３およびＲ_４は同一または異なって、炭素数１から６のアルキレン基を表し、平均付加モル数ｎ、ｍ、およびｌは０〜４０であって、（ｎ＋ｍ＋ｌ）が３〜４０となる数を表す。］

[In formula (N2), R ₁ represents hydrogen or a methyl group; R ₂ , R ₃ and R ₄ are the same or different and represent an alkylene group having 1 to 6 carbon atoms; And l are 0 to 40, and represent a number such that (n + m + 1) is 3 to 40. ]

［式（Ｎ３）中のＲ_１は水素またはメチル基を表し、Ｒ_２およびＲ_３は同一または異なって、炭素数１から６のアルキレン基を表し、Ｒ_４は炭素数１から３０の炭化水素基またはアシル基を表し、平均付加モル数ｍおよびｎは０〜４０、ただし（ｍ＋ｎ）は３〜４０の数を表す。］

[In the formula (N3), R ₁ represents hydrogen or a methyl group, R ₂ and R ₃ are the same or different and represent an alkylene group having 1 to 6 carbon atoms, and R ₄ is a hydrocarbon having 1 to 30 carbon atoms. Represents a group or an acyl group, and the average number of added moles m and n is 0 to 40, provided that (m + n) represents a number of 3 to 40. ]

［式（Ｎ４）中のＲ_１およびＲ_２は同一または異なって、炭素数１から３０の炭化水素基を表し、Ｒ_３は水素またはプロペニル基を表し、Ｒ_４は炭素数１から６のアルキレン基を表し、平均付加モル数ｎは３〜４０の数を表す。］

[In the formula (N4), R ₁ and R ₂ are the same or different and each represent a hydrocarbon group having 1 to 30 carbon atoms, R ₃ represents hydrogen or a propenyl group, and R ₄ represents an alkylene having 1 to 6 carbon atoms. And the average number of added moles n represents a number of 3 to 40. ]

［式（Ｎ５）中のＲ_１およびＲ_３は同一または異なって、炭素数１から６のアルキレン基を表し、Ｒ_２およびＲ_４は同一または異なって、水素、炭素数１から３０の炭化水素基、またはアシル基を表し、平均付加モル数ｍおよびｎは０〜４０、ただし（ｍ＋ｎ）は３〜４０の数を表す。］

[In formula (N5), R ₁ and R ₃ are the same or different and each represent an alkylene group having 1 to 6 carbon atoms, and R ₂ and R ₄ are the same or different and represent hydrogen, hydrocarbon having 1 to 30 carbon atoms. And an average number of added moles m and n are 0 to 40, provided that (m + n) represents a number of 3 to 40. ]

［式（Ｎ６）中のＲ_１、Ｒ_２、およびＲ_３は同一または異なって、水素またはメチル基を表し、Ｒ_４は炭素数０から３０の炭化水素基（炭素数０の場合はＲ_４がないことを示す）を表し、Ｒ_５およびＲ_６は同一または異なって、炭素数１から６のアルキレン基を表し、平均付加モル数ｍおよびｎは０〜４０、ただし（ｍ＋ｎ）は３〜４０の数を表す。］

[In the formula (N6), R ₁ , R ₂ , and R ₃ are the same or different and each represents hydrogen or a methyl group, and R ₄ is a hydrocarbon group having 0 to 30 carbon atoms (in the case of 0 carbon atoms, R ₄ R ₅ and R ₆ are the same or different and represent an alkylene group having 1 to 6 carbon atoms, and the average number of moles m and n is 0 to 40, provided that (m + n) is 3 to Represents the number 40. ]

  The number average molecular weight (Mn) of the polyether compound is suitably 50,000 or less, preferably from 200 to 30,000, more preferably from 200 to 10,000, and usually preferably from 200 to 5,000. . If Mn is too large, the compatibility with the base polymer (meth) acrylic polymer is reduced, and the pressure-sensitive adhesive layer tends to whiten. If Mn is less than 200, contamination by the polyether compound may easily occur. Here, Mn refers to a value in terms of polystyrene obtained by gel permeation chromatography (GPC).

  Specific examples of the polyether compound as a commercial product include, for example, Adecapluronic 17R-4, Adecapluronic 25R-1, Adecapluronic 25R-2, Adecapluronic L-23, Adecaria soap ER-10, Adecaria Soap NE-10 (all, manufactured by ADEKA), Emulgen 120, Latemul PD-420, Latemul PD-430 (all, manufactured by Kao Corporation), Surfynol 420, Surfynol 485 (all, Nisshin) Aqualon HS-10: Hytenol N-08, Neugen XL-40, Antifloss M-9, Epan 410, Aqualon KH-10, Aqualon RN-20, Hytenol NF-08, Plysurf A212C, (All of which are manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), PEG40 0, PEG600, Newpole PE-34, Sannics PP200 (all manufactured by Sanyo Chemical), Blemmer PME-400, Blemmer PME-1000, Blemmer 50POEP-800B (all manufactured by NOF CORPORATION), etc. No.

  The compounding amount of the polyether compound is 0.03 to 14 parts by mass, preferably 0.04 to 13 parts by mass, more preferably 0.04 to 13 parts by mass, based on 100 parts by mass of the (meth) acrylic polymer. It is 0.05 to 12 parts by mass, most preferably 0.05 to 10 parts by mass. If the compounding amount is too small, a suitable antistatic property (antistatic effect) cannot be obtained, and in addition, the wettability to the interlayer filler on the surface of the adherend after peeling the surface protective film may not be ensured. . If the amount is too large, contamination by the polyether compound may easily occur, which is not preferable.

<Antistatic component>
In the surface protective film of the present invention, the pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer can contain an antistatic component, and can contain an ionic compound as the antistatic component. Examples of the ionic compound include an alkali metal salt and / or an ionic liquid. By containing these ionic compounds, excellent antistatic properties can be imparted. The pressure-sensitive adhesive layer (using the antistatic component) obtained by crosslinking the pressure-sensitive adhesive composition containing the antistatic component as described above is used for an adherend that is not antistatic when peeled off (for example, a polarizing plate). ) Can be prevented, and a surface protective film with reduced contamination to the adherend can be obtained. For this reason, it becomes very useful as an antistatic surface protective film in a technical field related to optical and electronic parts where charging and contamination are particularly serious problems.

<Crosslinking agent>
In the surface protective film of the present invention, the pressure-sensitive adhesive composition preferably contains a crosslinking agent. In the present invention, the pressure-sensitive adhesive composition can be used to form a pressure-sensitive adhesive layer. For example, a surface protective film (adhesive layer) having more excellent heat resistance can be obtained by appropriately adjusting the structural units, the structural ratio, the selection and the addition ratio of the cross-linking agent, and the like of the (meth) acrylic polymer to perform cross-linking. be able to.

  As the crosslinking agent used in the present invention, an isocyanate compound, an epoxy compound, a melamine-based resin, an aziridine derivative, a metal chelate compound, or the like may be used. In particular, the use of an isocyanate compound is a preferred embodiment. Further, these compounds may be used alone or in combination of two or more.

  Examples of the isocyanate compound include aliphatic polyisocyanates such as trimethylene diisocyanate, butylene diisocyanate, hexamethylene diisocyanate (HDI), and dimer acid diisocyanate; Aromatic isocyanates such as cyclic isocyanates, 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate (XDI), and the above isocyanate compounds are allophanate bond, biuret bond, isocyanurate bond, uretdione bond , Urea bond, carbodiimide bond, uretonimine bond, oxadiazinetrione bond, etc. More denatured polyisocynate modified products thereof. For example, as commercial products, trade names Takenate 300S, Takenate 500, Takenate D165N, Takenate D178N (above, manufactured by Takeda Pharmaceutical Co., Ltd.), Sumidur T80, Sumidur L, Desmodur N3400 (above, manufactured by Sumika Bayer Urethane Co., Ltd.) , Millionate MR, Millionate MT, Coronate L, Coronate HL, Coronate HX (all manufactured by Nippon Polyurethane Industry Co., Ltd.). These isocyanate compounds may be used alone or as a mixture of two or more, and it is also possible to use a bifunctional isocyanate compound and a trifunctional or more functional isocyanate compound in combination. By using a cross-linking agent in combination, it is possible to achieve both tackiness and repulsion resistance (adhesion to a curved surface), and it is possible to obtain a surface protective film having more excellent adhesion reliability.

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

  Examples of the melamine-based resin include hexamethylolmelamine. Examples of the aziridine derivative include HDU, TAZM, and TAZO (trade names, manufactured by Mutual Pharmaceutical Co., Ltd.) as commercial products.

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

  The content of the crosslinking agent used in the present invention is preferably, for example, 0.01 to 10 parts by mass, preferably 0.1 to 8 parts by mass, based on 100 parts by mass of the (meth) acrylic polymer. It is more preferably contained, more preferably 0.5 to 6 parts by mass, and most preferably 1 to 5 parts by mass. When the content is less than 0.01 parts by mass, the crosslinking formation by the crosslinking agent becomes insufficient, the cohesive force of the obtained pressure-sensitive adhesive layer becomes small, and sufficient heat resistance may not be obtained. It tends to cause glue residue. On the other hand, when the content exceeds 10 parts by mass, the cohesive force of the polymer is large, the fluidity is reduced, the wetting on the adherend (for example, a polarizing plate) becomes insufficient, and the adherend and the pressure-sensitive adhesive It tends to cause blisters generated between the layer and the pressure-sensitive adhesive composition layer. Furthermore, when the amount of the cross-linking agent is large, there is a tendency that the peeling charging characteristics are reduced.

<Cross-linking catalyst>
The pressure-sensitive adhesive composition may further contain a crosslinking catalyst for causing any of the above-mentioned crosslinking reactions to proceed more effectively. Examples of such a crosslinking catalyst include tin catalysts such as dibutyltin dilaurate and dioctyltin dilaurate; tris (acetylacetonato) iron; tris (hexane-2,4-dionato) iron; and tris (heptane-2,4-dionato). Iron, tris (heptane-3,5-dionato) iron, tris (5-methylhexane-2,4-dionato) iron, tris (octane-2,4-dionato) iron, tris (6-methylheptane-2, iron) 4-dionato) iron, tris (2,6-dimethylheptane-3,5-dionato) iron, tris (nonane-2,4-dionato) iron, tris (nonane-4,6-dionato) iron, tris (2 , 2,6,6-tetramethylheptane-3,5-dionato) iron, tris (tridecane-6,8-dionato) iron, tris (1-phenylbutane-1,3) Dionato) iron, tris (hexafluoroacetylacetonato) iron, tris (ethyl acetoacetate) iron, tris (acetoacetate-n-propyl) iron, tris (isopropylacetoacetate) iron, tris (acetoacetate-n-butyl) Iron, tris (acetoacetate-sec-butyl) iron, tris (acetoacetate-tert-butyl) iron, tris (methyl propionyl acetate) iron, tris (ethyl propionyl acetate) iron, tris (propionyl acetate-n-propyl) iron Tris (propionyl acetate-n-butyl) iron, tris (propionyl acetate-sec-butyl) iron, tris (propionyl acetate-tert-butyl) iron, tris (benzyl acetoacetate) iron, Tris (dimethyl malonate) iron, tris (diethyl malonate) iron, trimethoxyiron, Iron-based catalysts such as iron triethoxy, iron triisopropoxy, and ferric chloride can be used. One of these crosslinking catalysts may be used alone, or two or more thereof may be used in combination.

  Although the content (use amount) of the crosslinking catalyst is not particularly limited, for example, 0.0001 to 1 part by mass, preferably 0.001 to 0.5 part by mass with respect to 100 parts by mass of the (meth) acrylic polymer. Parts by mass are more preferred. When it is within the above range, the rate of the crosslinking reaction when the pressure-sensitive adhesive layer is formed is increased, which is a preferable embodiment.

<Crosslinking retarder>
The pressure-sensitive adhesive composition may further include a crosslinking retarder. The crosslinking retarder is not particularly limited, for example, β-keto esters such as methyl acetoacetate, ethyl acetoacetate, octyl acetoacetate, oleyl acetoacetate, lauryl acetoacetate, stearyl acetoacetate, acetylacetone, 2,4- Β-diketones such as hexanedione and benzoylacetone are exemplified. Among them, acetylacetone can be used. The crosslinking retarders can be used alone or in combination of two or more.

  The content (use amount) of the crosslinking retarder is not particularly limited, but is preferably, for example, 0.1 to 10 parts by mass, and 0.1 to 5 parts by mass with respect to 100 parts by mass (when converted to) of the solvent. Parts are more preferred. Within the above range, the pot life of the pressure-sensitive adhesive can be extended, which is a preferable embodiment.

  The pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer of the present invention may further contain a solvent. Examples of the solvent include a solvent used in the above-described solution polymerization method. The solvent in the pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer of the present invention may be the same as or different from the solvent used in the solution polymerization method. The solvent in the pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer of the present invention can be used alone or in combination of two or more.

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

<Adhesive layer / surface protection film>
The surface protective film for a touch panel of the present invention is obtained by forming the pressure-sensitive adhesive layer on the second surface of the base material from a pressure-sensitive adhesive composition. It is generally performed after the application of the pressure-sensitive adhesive composition, but it is also possible to transfer a pressure-sensitive adhesive layer composed of the crosslinked pressure-sensitive adhesive composition to a substrate or the like.

  The method for forming the pressure-sensitive adhesive layer on the substrate is not particularly limited. For example, the pressure-sensitive adhesive composition (solution) is applied to a substrate, and a polymerization solvent or the like is removed by drying to form the pressure-sensitive adhesive layer on the substrate. It is produced by forming on. Thereafter, curing may be performed for the purpose of adjusting the migration of components of the pressure-sensitive adhesive layer or adjusting the crosslinking reaction. Further, when preparing a surface protective film by applying the pressure-sensitive adhesive composition on the substrate, so that the pressure-sensitive adhesive composition can be uniformly coated on the substrate, one or more solvents other than the polymerization solvent in the pressure-sensitive adhesive composition. It may be newly added.

  In addition, as a method for forming the pressure-sensitive adhesive layer when the surface protective film of the present invention is produced, a known method used for producing pressure-sensitive adhesive tapes is used. Specific examples include roll coating, gravure coating, reverse coating, roll brushing, spray coating, air knife coating, and extrusion coating using a die coater.

  The surface protective film of the present invention is usually prepared so that the pressure-sensitive adhesive layer has a thickness of 3 to 100 μm, preferably about 5 to 50 μm. It is preferable that the thickness of the pressure-sensitive adhesive layer be within the above-mentioned range because a proper balance between removability and adhesiveness can be easily obtained.

  The surface protective film of the present invention preferably has a total thickness of 1 to 400 μm, more preferably 10 to 200 μm, and even more preferably 20 to 100 μm. When it is in the above range, the adhesive properties (removability, adhesiveness, etc.), workability, and appearance properties are excellent, which is a preferable embodiment. The total thickness means the total thickness including all layers such as the base material, the pressure-sensitive adhesive layer, and the antistatic layer.

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

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

  The thickness of the separator is usually about 5 to 200 μm, preferably about 10 to 100 μm. It is preferable for it to be in the above-mentioned range because the workability of laminating to the pressure-sensitive adhesive layer and the workability of peeling from the pressure-sensitive adhesive layer are excellent. The separator may be, if necessary, a silicone-based, fluorine-based, long-chain alkyl-based or fatty acid amide-based release agent, a release and antifouling treatment with silica powder or the like, a coating type, a kneading type, a vapor deposition type. For example, antistatic treatment such as antistatic treatment can be performed.

<Optical members>
The optical member mounted on the touch panel of the present invention is preferably protected by the surface protective film for a touch panel. The surface protective film has excellent antistatic properties, excellent stability over time of the peeling voltage, can confirm the operation of the touch panel, and has excellent wettability to the interlayer filler on the surface of the adherend after peeling the surface protective film. It can be used for surface protection applications (surface protection films) at the time of processing, transportation, shipping inspection, etc., and is useful for protecting the surface of the optical member (such as a polarizing plate mounted on a touch panel). In particular, since it can be used for plastic products that easily generate static electricity, it is very useful for antistatic applications in optical and electronic component-related technical fields where charging is a particularly serious problem.

  Hereinafter, some examples related to the present invention will be described, but it is not intended to limit the present invention to those shown in the specific examples. Note that “parts” and “%” in the following description are based on mass unless otherwise specified. In addition, the blending amount (addition amount) in the table indicates a solid content or a solid content ratio.

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

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

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

<Glass transition temperature (Tg)>
The glass transition temperature Tg (° C.) was determined by the following equation using the following literature value as the glass transition temperature Tgn (° C.) of the homopolymer of each monomer.
Formula: 1 / (Tg + 273) = Σ [Wn / (Tgn + 273)]
[Where Tg (° C.) is the glass transition temperature of the copolymer, Wn (−) is the weight fraction of each monomer, Tgn (° C.) is the glass transition temperature of the homopolymer of each monomer, and n is the type of each monomer. Represents ]
Literature values:
2-ethylhexyl acrylate (2EHA): -70 ° C
2-hydroxyethyl acrylate (HEA): -15 ° C
4-hydroxybutyl acrylate (4HBA): -32 ° C
Acrylic acid (AA): 106 ° C

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

<Measurement of surface resistance value>
The measurement was performed in an atmosphere of a temperature of 23 ° C. and a humidity of 50% RH using a resistivity meter (manufactured by Mitsubishi Chemical Analytic, Hiresta UP MCP-HT450) according to JIS-K-6911.
The surface resistance value (Ω / □) in the present invention is preferably 1.0 × 10 2 at the initial stage and at room temperature (23 ° C. × 50% RH) × one week (7 days). ⁷ or more and less than 1.0 × 10 ¹¹ , more preferably 1.0 × 10 ⁸ or more and less than 5.0 × 10 ¹⁰ , still more preferably 1.0 × 10 ⁹ or more and 2.0 × 10 ^10. Is less than. The surface protective film having a surface resistance value within the above range can be suitably used as a surface protective film used in, for example, a process or a process of transporting an article that does not like static electricity such as a liquid crystal cell or a semiconductor device. Further, the surface protective film having a surface resistance value within the above range, the polarizing plate is mounted above the touch panel sensor, even in a state where the surface protective film is stuck on the polarizing plate, it is possible to confirm the operation. Can be useful.

<Operation check of touch panel>
Using iPhone5s (manufactured by Apple Inc.) equipped with an in-cell type touch panel, evaluation of the operation confirmation of the touch panel was evaluated. First, a surface protection film was stuck on the screen of the iPhone 5s, and when the screen was traced with a finger, the touch panel responded visually or visually to confirm the operability.
：: When the touch panel responds accurately.
X: When the touch panel does not respond accurately.

<Water contact angle>
After a surface protective film is adhered to the surface of the adherend (hard coat film) at a temperature of 23 ° C. and a humidity of 50%, it is put into an autoclave and treated at a temperature of 50 ° C., a pressure of 5 atm and a time of 15 minutes. And allowed to stand for 12 hours at a temperature of 23 ° C. and a humidity of 50% for peeling. The adherend to which the surface protective film was adhered using a water contact angle measuring device (trade name “DM700”, manufactured by Kyowa Interface Chemical Co., Ltd.) by an appropriate liquid method under an atmosphere of a temperature of 23 ° C. and a humidity of 50% RH. About 2.8 μL of a water droplet was dropped on the surface, and an angle formed by a tangent line between the surface of the adherend and the end of the dropped water droplet one second after the drop was measured, and was defined as “water contact angle (°)”. The case where the water contact angle was 35 ° or less was evaluated as “(good in wettability) (○)”, and the case where the water contact angle was more than 35 ° was evaluated as “poor (x)” in (wetability).
The water contact angle of the adherend without any treatment was 37.2 °. That is, the adherend used in this evaluation was a triacetyl cellulose film having a water contact angle of 37.2 °.

<Wetability of interlayer filler>
After a surface protective film is adhered to the surface of the adherend at a temperature of 23 ° C. and a humidity of 50%, it is put into an autoclave, treated under the conditions of a temperature of 50 ° C., a pressure of 5 atm, and a time of 15 minutes, and adhered. It was allowed to stand at 23 ° C. and 50% humidity for 12 hours. Thereafter, the adherend to which the surface protection film was attached was cut into a length of 40 mm and a width of 40 mm, and was attached to a glass plate having a length of 50 mm and a width of 50 mm. The glass plate was attached to a spin coater (trade name “K-359SD1”). , Manufactured by Kyowa Riken Co., Ltd.). Thereafter, the surface protective film was peeled off from the adherend, and 4 ml of trade name “SVR7000 series” (manufactured by Dexerials) was applied as an interlayer filler to the surface of the adherend on which the surface protective film was adhered, and 1500 rpm for 15 seconds. By rotating, the interlayer filler was uniformly spread. After leaving still for 1 hour at a temperature of 23 ° C. and a humidity of 50%, the distance at which the interlayer filler was repelled from the edge of the adherend was measured with a ruler.
The same measurement was performed using "WORLD ROCK HRJ-21" (trade name, manufactured by Kyoritsu Chemical Industry Co., Ltd.) as an interlayer filler.
Regardless of the use of any of the interlayer fillers of “SVR7000 series” and “WORLD ROCK HRJ-21”, if the distance repelled from the edge is shorter than 2 mm, “good (）)” indicates one or both layers When the filler was used and the distance repelled from the edge was 2 mm or more, it was evaluated as "poor (x)". The adherend used in this evaluation is the same as the adherend used in the evaluation of the “water contact angle”.

<Measurement of polarizer peeling voltage (polarizer side)>
After cutting the surface protective film 1 according to each example into a size of 70 mm in width and 130 mm in length and peeling off the release liner, as shown in FIG. 3, an acrylic plate 10 (made by Mitsubishi Rayon Co., Ltd. On the surface of a polarizing plate 20 (manufactured by Nitto Denko Corporation, SEG1423DU polarizing plate, width: 70 mm, length: 100 mm) bonded to a product name “Acrylite”, thickness: 1 mm, width: 70 mm, length: 100 mm) One end of the surface protective film 1 was pressed by a hand roller so as to protrude 30 mm from the end of the polarizing plate 20.
The sample was left in an environment of 23 ° C. × 50% RH for one day, and then set at a predetermined position on a sample fixing table 30 having a height of 20 mm. The end of the surface protective film 1 protruding 30 mm from the polarizing plate 20 was fixed to an automatic winder (not shown), and peeled at a peel angle of 150 ° and a peel speed of 10 m / min. The potential of the surface of the adherend (polarizing plate) generated at this time is fixed to a position at a height of 100 mm from the center of the polarizing plate 20 (Kasuga Electric Co., Ltd., model “KSD-0103”). , The "initial polarizing plate peeling voltage" was measured. The measurement was performed in an environment of 23 ° C. and 50% RH.
In addition, after allowing to stand for one week (7 days) in an environment of 23 ° C. × 50% RH, the “time-dependent polarizing plate peeling voltage” was measured in the same manner as the “initial polarizing plate peeling voltage”. The measurement was performed in an environment of 23 ° C. × 50% RH.
The polarizing plate peeling voltage is a peeling voltage derived from the antistatic layer and the pressure-sensitive adhesive layer constituting the surface protective film of the present invention, and contributes to the antistatic property.
The polarizing plate peeling voltage (kV) (absolute value, both initial and temporal) in the present invention is preferably 1.8 kV or less, more preferably 1.7 kV or less, and still more preferably 1. 6 kV or less. Within the above range, for example, damage to the liquid crystal driver or the like can be prevented, which is a preferable embodiment.

<Contamination of polarizing plate>
The surface protection film was cut into a size of 50 mm in width and 80 mm in length together with the release liner, and the release liner was removed to expose the adhesive surface. The adhesive surface was pressure-bonded to a polarizing plate (manufactured by Nitto Denko Corporation, SEG1423DU polarizing plate) with a hand roller. After leaving this in an environment of 23 ° C. × 50% RH for one week, the surface protective film was peeled off from the adherend by hand. The surface of the adherend after peeling was placed under a bright place (normal indoor environment with a fluorescent lamp on the ceiling as illumination) and under a fluorescent lamp in a dark room (outside light was blocked by a light-shielding curtain, and only the tabletop fluorescent lamp was illuminated. Environment) to evaluate the state of contamination. The evaluation criteria are as follows.
：: No contamination was observed under a light place.
×: When contamination was observed under a light place.

<Preparation of acrylic polymer (A) for adhesive layer>
100 parts by mass of 2-ethylhexyl acrylate (2EHA), 4 parts by mass of 2-hydroxyethyl acrylate (HEA), and 2 parts as a polymerization initiator were placed in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser. 0.2 parts by mass of 2,2'-azobisisobutyronitrile and 157 parts by mass of ethyl acetate were charged, nitrogen gas was introduced with gentle stirring, and the liquid temperature in the flask was maintained at about 65 ° C for 6 hours. The reaction was performed to prepare an acrylic polymer (A) solution (40% by mass). The acrylic polymer (A) had a weight average molecular weight of 540,000 and a glass transition temperature (Tg) of -68 ° C.

<Preparation of acrylic polymer (B) for adhesive layer>
100 parts by mass of 2-ethylhexyl acrylate (2EHA), 10 parts by mass of 4-hydroxybutyl acrylate (4HBA), and acrylic acid (AA) in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser. 0.02 parts by mass, 0.2 parts by mass of 2,2′-azobisisobutyronitrile as a polymerization initiator, and 157 parts by mass of ethyl acetate were charged, and nitrogen gas was introduced with gentle stirring, and the solution in the flask was charged. The polymerization reaction was carried out for 6 hours while maintaining the temperature at about 65 ° C. to prepare an acrylic polymer (B) solution (40% by mass). The acrylic polymer (B) had a weight average molecular weight of 540,000 and a glass transition temperature (Tg) of -67 ° C.

<Preparation of aqueous solution for antistatic layer (C)>
Polyester resin Vironal MD-1480 (25% aqueous solution, manufactured by Toyobo Co., Ltd.) as a binder, polyanilinesulfonic acid (aquapass, weight average molecular weight 40,000, manufactured by Mitsubishi Rayon Co., Ltd.) as a conductive polymer, and hexamethylene blocked with diisopropylamine as a crosslinking agent Isocyanurate of diisocyanate, oleamide in a mixed solvent of water / ethanol (1/3) as a lubricant, 100 parts by mass of binder in solid content, 75 parts by mass of conductive polymer in solid content, and solid agent of cross-linking agent 10 parts by mass of the lubricant and 30 parts by mass of the lubricant were added, and the mixture was stirred for about 20 minutes and mixed well. Thus, an aqueous solution for the antistatic layer (C) having an NV of about 0.4% was prepared.

<Preparation of aqueous solution for antistatic layer (D)>
Polyester resin Vironal MD-1480 (25% aqueous solution, manufactured by Toyobo Co., Ltd.) as a binder, poly (3,4-ethylenedioxythiophene) (PEDOT) 0.5% as a conductive polymer, and polystyrene sulfonate (weight average molecular weight 150,000) (PSS) An aqueous solution containing 0.8% (Bytron P, manufactured by H. C. Stark) was mixed with a mixed solvent of water / ethanol (1/1), a binder was added in an amount of 100 parts by mass in terms of solid content, and a conductive polymer was added. 50 parts by mass of the solid content and 2.5 parts by mass of the melamine-based crosslinking agent were added, and the mixture was stirred for about 20 minutes and mixed well. Thus, an aqueous solution for the antistatic layer (D) having an NV of about 0.4% was prepared.

<Preparation of substrate with antistatic layer>
The antistatic layer (C) is provided on a corona-treated surface of a transparent polyethylene terephthalate (PET) film (polyester film) having a thickness of 38 μm, a width of 30 cm, and a length of 40 cm in which one surface (first surface) is corona-treated. ) Or (D) was applied so that the thickness after drying was 30 nm or 50 nm. The coated material was heated at 130 ° C. for 1 minute and dried to prepare a substrate having an antistatic layer having an antistatic layer on the first surface of the PET film.

<Example 1>
(Preparation of acrylic pressure-sensitive adhesive solution)
The acrylic polymer (A) solution (40% by mass) was diluted to 20% by mass with ethyl acetate, and 500 parts by mass (100 parts by mass of solid content) of this solution was mixed with an isocyanurate of hexamethylene diisocyanate (500 parts by mass of solid content) as a crosslinking agent ( 3 parts by mass (Coronate HX, manufactured by Nippon Polyurethane Industry Co., Ltd.) (solids content: 3 parts by mass), dibutyltin dilaurate (trade name: OL-1, manufactured by Tokyo Fine Chemical Co., Ltd.) (1% by mass ethyl acetate solution) as a cross-linking catalyst Parts (solid content 0.03 parts by mass), acetylacetone as a crosslinking retarder is 3 parts by mass with respect to 100 parts by mass of the solvent (when converted), and polyethylene glycol (trade name: PEG400, (Average molecular weight: 400, manufactured by Sanyo Chemical Co., Ltd.), 0.05 parts by mass, and mixing and stirring to prepare an acrylic pressure-sensitive adhesive solution .

[Production of surface protective film]
The acrylic pressure-sensitive adhesive solution is applied to the surface of the substrate having the antistatic layer (the substrate with the antistatic layer) opposite to the antistatic layer, and heated at 130 ° C. for 1 minute to form a 15 μm thick film. An adhesive layer was formed. Next, a silicone-treated surface of a polyethylene terephthalate film (thickness: 25 μm), which is a separator having one surface subjected to silicone treatment, was adhered to the surface of the pressure-sensitive adhesive layer to prepare a surface protective film for a touch panel.

<Examples 2 to 10 and Comparative Examples 1 to 4>
Based on the contents of Tables 1 to 3, a surface protective film was produced in the same manner as in Example 1.

  Tables 4 and 5 show the results of the various measurements and evaluations described above for the surface protective films according to the examples and comparative examples.

Abbreviations in Tables 1 and 3 are described below.
2EHA: 2-ethylhexyl acrylate HEA: 2-hydroxyethyl acrylate 4HBA: 4-hydroxybutyl acrylate AA: acrylic acid (AA)
Adecapluronic 25R-1: polyoxyethylene-polyoxypropylene block copolymer (ADEKA company, polyether compound)
Surfynol 420: a polyether compound of 2,4,7,9-tetramethyl-5-decyne-4,7-diol (a polyether compound manufactured by Nissin Chemical Co., Ltd.)
Surfynol 485: polyether compound of 2,4,7,9-tetramethyl-5-decyne-4,7-diol (polyether compound manufactured by Nissin Chemical Co., Ltd.)
Aqualon HS-10: polyoxyethylene nonylpropenyl phenyl ether ammonium sulfate (a polyether compound manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
Latemul PD-420: polyoxyalkylene alkenyl ether (polyether compound, manufactured by Kao Corporation)
PEG400: polyethylene glycol (number average molecular weight: 400, manufactured by Sanyo Chemical Industries, polyether compound)
PP200: polypropylene glycol (number average molecular weight: 200, manufactured by Sanyo Chemical Industries, polyether compound)

  From the above evaluation results, it was confirmed that in all the examples, the antistatic property and the stability over time of the peeling voltage were excellent, and further, there was no problem in the operation check of the touch panel, and it was confirmed that the touch panel was practical. In addition, it was confirmed that when the polyether compound was blended in the adhesive layer at a specific ratio, the wettability and the contamination were excellent.

  On the other hand, in Comparative Example 1, since no polyether compound was used, it was confirmed that the wettability was poor and the antistatic property was poor. In Comparative Example 2, since the polyether compound was added in an amount smaller than the desired ratio, it was confirmed that antistatic properties could not be obtained. In Comparative Example 3, it was confirmed that contamination was poor because a large amount of the polyether compound was blended. In Comparative Example 4, the use of a water-dispersed conductive polymer (PEDOT / PSS) as a component of the antistatic layer resulted in too low a surface resistance value, so that operation of the touch panel could not be confirmed, and It was confirmed that it was not a target. Further, it was confirmed that the antistatic property and the stability over time of the peeling voltage were inferior. Although the details of the reason why such a problem is desired are not clear, it is presumed that the antistatic property of the entire surface protective film deteriorates due to the deterioration of the antistatic layer.

  The surface protective film disclosed herein can be used for manufacturing or transporting optical members such as polarizing plates used as components of liquid crystal display panels, plasma display panels (PDPs), and organic electroluminescence (EL) displays. It is suitable as a surface protection film for protecting members. In particular, it is useful as a surface protection film (optical surface protection film) applied to an optical member such as a polarizing plate mounted on an on-cell type or in-cell type touch panel.

1: surface protection film 3: touch panel 10: acrylic plate 20: polarizing plate 3
0: sample fixing base 40: potential measuring instrument 11: antistatic layer 12: base material 13: adhesive layer 31: polarizing plate 32: touch sensor 33: base glass 34: liquid crystal

Claims (6)

A substrate having a first surface and a second surface, an antistatic layer provided on the first surface of the substrate, and an adhesive layer formed of an adhesive composition on the second surface of the substrate. And a surface protective film for a touch panel comprising:
The antistatic layer is formed from an antistatic agent composition containing a polyanilinesulfonic acid as a conductive polymer component, a polyester resin as a binder, a fatty acid amide as a lubricant, and an isocyanate-based crosslinking agent as a crosslinking agent,
For 100 parts by mass of the polyester resin, the polyaniline sulfonic acid contains 10 to 200 parts by mass,
The proportion of the lubricant in the entire antistatic layer is 1 to 50% by mass,
The pressure-sensitive adhesive composition contains a (meth) acrylic polymer, and a polyether compound,
A surface protection film for a touch panel, comprising 0.03 to 14 parts by mass of the polyether compound based on 100 parts by mass of the (meth) acrylic polymer. The surface protective film for a touch panel according to claim 1, wherein the substrate contains polyethylene terephthalate and / or polyethylene naphthalate. 3. The touch panel according to claim 1, wherein the conductive polymer component further comprises at least one selected from the group consisting of polythiophene, polyaniline, polypyrrole, polyethyleneimine, and allylamine-based polymer. 4. Surface protection film. The surface protective film for a touch panel according to any one of claims 1 to 3, wherein the polyether compound is a surfactant. An optical member mounted on the touch panel,
Light faculty member you wherein Tei Rukoto protected by a surface protective film for a touch panel according to claim 1. It is a manufacturing method of the surface protective film for touch panels according to any one of claims 1 to 4,
A touch panel comprising: a step of preparing an aqueous solution containing the antistatic agent composition; and a step of applying and drying the aqueous solution on the first surface of the substrate to prepare an antistatic layer. Production method of surface protection film.

Images