JP2019061682A - Surface protective film, production method of surface protective film, and optical member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a touch panel having excellent antistatic property and stability of peeling band voltage with time, checking the operation of a touch panel, and having excellent wettability to an interlayer filler on the surface of an adherend after peeling a surface protective film. Provided are a surface protective film for use, a method for producing the surface protective film, and an optical member. A surface protective film 1 for a touch panel adheres to a base material 12 having a first surface and a second surface, an antistatic layer 11 provided on the first surface of the base material, and a second surface of the base material. The pressure-sensitive adhesive layer 13 formed from the agent composition is provided. The antistatic layer 11 is formed of an antistatic agent composition containing polyaniline sulfonic acid as a conductive polymer component, a polyester resin as a binder, and an isocyanate-based cross-linking agent as a cross-linking agent. The pressure-sensitive adhesive composition contains a (meth) acrylic polymer and a polyether compound, and contains 0.03 to 14 parts by mass of the polyether compound with respect to 100 parts by mass of the (meth) acrylic polymer. [Selection diagram] Fig. 1

Description

  The present invention relates to a surface protection film for a touch panel, a method of 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 bonded to an adherend (object to be protected) via the pressure-sensitive adhesive layer, and thereby used for the purpose of protecting the adherend from scratches and dirt during processing, transportation, and the like.

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

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

  Moreover, PEDOT (poly (3, 4- ethylene di oxythiophene) / PSS (polystyrene sulfonate) (polythiophene type) system is used as a conductive polymer used in order to provide an antistatic function to the surface layer of a surface protection film in recent years. However, in the case of the aqueous dispersion type, aggregates are generated when it is stored in a solution state, and a uniform antistatic layer can not be formed, which makes it easy to operate. In addition, when an antistatic layer is formed using the conductive polymer, PSS (corresponding to a dopant) is desorbed from PEDOT with the passage of time, and the surface resistance value and the peeling voltage are obtained. As a result, there is a risk that problems such as an increase in surface resistance value (deterioration) 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 of the touch sensor, the surface of the surface protective film is checked when the operation of the touch panel is checked in a state where the protective film is attached to the polarizing plate. When the surface resistance value of the layer is too low, the touch panel does not react and inspection can not be performed, and when the surface resistance value is too high, static electricity is generated, and there is a concern that a problem may occur.

  Moreover, when a surface protection film is exfoliated from an optical member at the stage when it became unnecessary and the layer (other layer) etc. which has another function are provided on the adherend surface to which the surface protection film was stuck. There is. Depending on the condition of the surface of the adherend after peeling off the surface protective film, the wettability to other layers may deteriorate, and the other layers may not exhibit the expected function or the product may be defective. The case is of concern. Specifically, when another layer such as a layer having a touch panel function is provided on the surface of the polarizing plate, it is provided to protect the surface of the polarizing plate (for example, a polarizing plate whose surface layer is a hard coat layer). After peeling off the surface protection film, an 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 adherend surface after peeling off the surface protective film, development of a surface protective film capable of securing a state excellent in wettability is required.

JP 2004-223923 A JP 2008-255332 A

  Then, as a result of earnestly researching in view of the above-mentioned circumstances, the present invention is excellent in the antistatic property and the stability over time of the peeling voltage, and the operation of the touch panel can be confirmed, and adhesion after peeling the surface protection film The surface protection film for touchscreens excellent also in the wettability with respect to the interlayer filler in a body surface, the manufacturing method of the said surface protection film, and an object to provide an optical member.

  That is, the surface protection film for a touch panel of the present invention comprises 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 And a pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive composition, wherein the antistatic layer comprises polyaniline sulfonic acid as a conductive polymer component, a polyester resin as a binder, and a crosslinking agent. The pressure-sensitive adhesive composition is formed of 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 100 parts by mass of the (meth) acrylic polymer On the other hand, it is characterized by containing 0.03-14 mass parts of said polyether compounds.

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

  In the surface protection film for a touch panel according to the present invention, preferably, the antistatic agent composition further contains a fatty acid amide as a lubricant.

  It is preferable that the said polyether compound is surfactant for the surface protection film for touchscreens of this invention.

  Preferably, the optical member mounted on the touch panel of the present invention is protected by the surface protection film for a touch panel

  The method for producing a surface protective film for a touch panel according to the present invention comprises the steps 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. It is preferable to include the step of preparing.

  The surface protective film of the present invention can form a uniform antistatic layer by forming the antistatic layer from an antistatic agent composition containing a specific conductive polymer component, a binder, and a crosslinking agent. The working property is also excellent, and furthermore, the antistatic property based on the antistatic layer and the temporal stability of the peeling charging voltage are good, the operation of the touch panel can be confirmed, and the pressure-sensitive adhesive layer ) After peeling off a surface protection film attached to an adherend such as a polarizing plate by forming from an adhesive composition containing an acrylic polymer and a polyether compound in a specific ratio, an interlayer is formed on the same adherend surface Even when the filler is applied, a surface protection film for a touch panel having excellent wettability to the interlayer filler, a method for producing the surface protection film, and an optical member can be obtained, which is preferable. It has the aspect.

It is a schematic cross section which shows one structural example of the surface protection film for touchscreens which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is typical sectional drawing of one structural example of the touch panel which stuck the surface protection film for touch panels of this invention. It is an explanatory view showing the measuring method of exfoliation charge voltage.

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

<Whole structure of surface protection 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, adhesive tape, adhesive label, adhesive film, surface protection sheet, etc. The surface protection film which protects the surface of an optical member at the time of processing or conveyance of an optical member such as a polarizing plate attached via a pressure sensitive adhesive layer on a touch sensor or glass in a liquid crystal display panel. Is preferred. The pressure-sensitive adhesive layer in the surface protective film is typically formed continuously, but is not limited to such a form, and is formed, for example, in a regular or random pattern such as dot-like or stripe-like. It may be an adhesive layer. In addition, the surface protection film disclosed herein may be in the form of a roll or in the form of a single sheet.

  Typical structural examples of the surface protective film disclosed herein are schematically shown in FIGS. 1 and 2. The surface protective film 1 comprises a substrate (for example, a polyester film) 12, an antistatic layer 11 provided on the first surface 12, and a second surface of the substrate 12 (on the side opposite to the antistatic layer 11). And an adhesive layer 13 provided on the surface). The surface protective film 1 adheres the pressure-sensitive adhesive layer 13 to the adherend (a protection target is polarized light attached to 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 stuck and used on the surface of optical members, such as board 31 grade. The surface protection film 1 before use (that is, before application to an adherend) is a peel-off surface in which the surface of the pressure-sensitive adhesive layer 13 (adhesion surface to an adherend) is at least a release surface on the side It may be in a form protected by a liner. Alternatively, even if the surface protective film 1 is wound in a roll, the pressure-sensitive adhesive layer 13 is in contact with the back surface of the substrate 12 (the surface of the antistatic layer 11) and the surface is protected. Good.

  As shown in FIG. 1, an embodiment in which the antistatic layer 11 is formed directly on the first surface of the substrate 12 (without any other layer), and the antistatic layer 11 is exposed on the back surface of the surface protective film 1 (That is, the embodiment in which the antistatic layer 11 doubles as the top coat layer) has an antistatic layer provided with the antistatic layer 11 on the substrate 12 as compared with the configuration in which the antistatic layer is provided separately from the top coat layer. The film (as a result, the surface protective film using the film) is advantageous also from the viewpoint of productivity improvement and the like because the number of layers constituting the surface protective film can be reduced.

<Base material>
The surface protective film of the present invention is characterized by having a substrate having a first surface (rear 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 particular limitation, and for example, transparency, mechanical strength, thermal stability, moisture shielding property, isotropy, flexibility It is preferable to use those excellent in properties such as the properties and dimensional stability. In particular, when the substrate has flexibility, the pressure-sensitive adhesive composition can be applied by a roll coater or the like, and can be rolled up in a roll, which is useful.

  Examples of the substrate (support) include polyester-based polymers such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN) and polybutylene terephthalate; cellulose-based polymers such as diacetyl cellulose and triacetyl cellulose; polycarbonate-based polymers; An acrylic polymer such as methyl methacrylate; a plastic film composed of a resin material having as a main resin component (a main component of the resin component, typically, 50% by mass or more) as the substrate It can be used preferably. As other examples of the resin material, styrene-based polymers such as polystyrene and acrylonitrile-styrene copolymer; olefin-based polymers such as polyethylene, polypropylene, polyolefin having a cyclic to norbornene structure, ethylene-propylene copolymer and the like; An example is a vinyl chloride-based polymer; an amide-based polymer such as nylon 6, nylon 6, 6 or aromatic polyamide; or the like as a resin material. Still other examples of the resin material include imide polymers, sulfone polymers, polyethersulfone polymers, polyetheretherketone polymers, polyphenylene sulfide polymers, vinyl alcohol polymers, vinylidene chloride polymers, vinyl butyral polymers And arylate polymers, polyoxymethylene polymers, epoxy polymers and the like. It may be a substrate comprising 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 employed. Among the plastic films, it is a more preferable aspect to use a polyester film. Here, the polyester film is mainly composed of a polymer material (polyester resin) having a main skeleton based on an ester bond, such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate etc. Say. The polyester film has preferable characteristics as a substrate of the surface protective film, such as excellent optical characteristics and dimensional stability. Among them, it is particularly preferable to contain polyethylene terephthalate and / or polyethylene naphthalate as the substrate.

  If necessary, various additives such as an antioxidant, an ultraviolet absorber, a plasticizer, a colorant (pigment, dye, etc.) may be blended in the resin material constituting the base material. The first surface (the surface on which the antistatic layer is provided) of the polyester film is known or commonly used, such as corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, application of an undercoat, etc. Surface treatment may be applied. Such surface treatment may be, for example, treatment for enhancing the adhesion between the substrate and the antistatic layer. A surface treatment may be preferably employed in which a polar group such as a hydroxyl group is introduced to the surface of the substrate. The same surface treatment as described above may be applied to the second surface of the substrate (the surface on which the pressure-sensitive adhesive layer is formed). Such surface treatment may be treatment for enhancing 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 which has been subjected to an antistatic treatment as the substrate. is there. By using the said base material, since charging of the surface protection film itself at the time of peeling is suppressed, it is preferable. Further, the substrate is a plastic film, and by subjecting the plastic film to an antistatic treatment, charging of the surface protective film itself can be reduced, and a substrate having excellent antistatic performance to an adherend can be obtained. In addition, there is no restriction | limiting in particular as a method of providing an antistatic function, A conventionally well-known method can be used, For example, antistatic resin, an electroconductive polymer, an electroconductive substance which consists of an antistatic agent and a resin component The method of applying the conductive resin to be contained, the method of depositing or plating the conductive substance, the method of kneading the antistatic agent and the like, and the like can be mentioned.

  The thickness of the substrate is generally 5 to 200 μm, preferably about 10 to 100 μm. It is preferable that the thickness of the substrate is in the above-mentioned range, because the bonding workability to the adherend and the peeling workability from the adherend are excellent.

<Antistatic layer (top coat layer)>
The surface protective film of the present invention is provided on a substrate having a first surface (rear surface) and a second surface (surface opposite to the first surface), and the first surface (rear surface) of the substrate A surface protection 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 comprises polyaniline sulfonic acid as a conductive polymer component. It is characterized in that it is formed from an antistatic agent 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 temporal stability of the release voltage are improved, which is a preferable embodiment.

<Conductive polymer>
The antistatic layer is characterized by containing polyaniline sulfonic acid as a conductive polymer component. By using the conductive polymer, it is possible to satisfy the antistatic property based on the antistatic layer and the peeling charge voltage with time. The polyaniline sulfonic acid is "water-soluble", but can be fixed in the antistatic layer by using an isocyanate-based crosslinking agent described later, and the water resistance can be improved. By using the water-soluble conductive polymer-containing aqueous solution, an antistatic layer having excellent surface resistance over time can be obtained, which is a preferable embodiment. On the other hand, when the conductive polymer used when forming the antistatic layer is "water-dispersible", when the antistatic layer is formed using the water-dispersible conductive polymer-containing solution, aggregates are generated. It is not preferable because it tends to be easy to apply uniformly, and the surface resistance value with the passage of time tends to be extremely low.

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

The polyaniline sulfonic acid used as the conductive polymer component preferably has a polystyrene equivalent weight average molecular weight (Mw) 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 the antistatic layer on the first surface of a substrate (support) can be employed. The conductive polymer component used to prepare the coating material contains polyaniline sulfonic acid, a polyester resin as a binder, and an isocyanate-based crosslinking agent as a crosslinking agent as an essential component, and the form in which the essential component is dissolved in water And the like (electroconductive polymer aqueous solution or simply referred to as 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 technique such as copolymerizing a monomer having a hydrophilic functional group in the molecule) in water. can do. The hydrophilic functional group, a sulfo group, an amino group, an amide group, an imino group, a hydroxyl group, a mercapto group, a hydrazino group, a carboxyl group, quaternary ammonium groups, sulfate ester group (-O-SO 3 _H), phosphorus An acid ester group (for example, -O-PO (OH) ₂ ) etc. are illustrated. Such hydrophilic functional groups may form a salt.

  Moreover, as a commercial item of the said polyaniline sulfonic-acid aqueous solution, the brand name "aqua-PASS" by Mitsubishi Rayon Co., Ltd. etc. is illustrated.

  The antistatic layer disclosed herein contains polyaniline sulfonic acid (polyaniline type) as an essential component as the conductive polymer component, but, for example, one or more other antistatic components (conductive polymer (conductive polymer) Other organic conductive materials, inorganic conductive materials, antistatic agents, etc.) may be included together. 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 the conductive polymer. The aspect which consists of may be implemented more preferably.

  As the organic conductive material, cationic antistatic agents having cationic functional groups such as quaternary ammonium salts, pyridinium salts, primary amino groups, secondary amino groups, tertiary amino groups, etc .; sulfonates and sulfates Anionic antistatic agent having an anionic functional group such as salt, phosphonic acid salt, phosphoric acid ester salt, etc .; alkylbetaine and its derivative, imidazoline and its derivative, zwitterionic antistatic agent such as alanine and its derivative; amino alcohol And nonionic antistatic agents such as glycerol and derivatives thereof, polyethylene glycol and derivatives thereof, and the like; monomers having the cationic, anionic or amphoteric ion conductive group (for example, 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.

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

  Examples of the antistatic agent include a cationic antistatic agent, an anionic antistatic agent, an amphoteric ion antistatic agent, a nonionic antistatic agent, and a monomer having an ionic conductive group of the cationic type, anionic type, and amphoteric ion type. And ion conductive polymers obtained by polymerizing or copolymerizing them.

<Binder>
The antistatic layer is characterized by containing, as an essential component, a polyester resin as a binder. It is preferable that the said polyester resin is a resin material which contains polyester as a main component (Typically, it is a component which occupies more than 50 mass%, Preferably 75 mass% or more, for example, 90 mass% or more). The polyester is typically a polyvalent carboxylic acid (typically a dicarboxylic acid) having two or more carboxyl groups in one molecule and a derivative thereof (an anhydride, an esterified product of the polyvalent carboxylic acid, a halogen) Selected from one or more compounds (polyvalent carboxylic acid components) selected from organic compounds and the like, and polyhydric alcohols (typically diols) having two or more hydroxyl groups in one molecule It is preferable to have a structure in which one or more compounds (polyhydric alcohol components) are condensed.

  Examples of compounds that can be adopted as the polyvalent carboxylic acid component include oxalic acid, malonic acid, difluoromalonic acid, alkyl malonic acid, succinic acid, tetrafluorosuccinic acid, alkyl succinic acid, (±) -malic acid, meso -Tartaric acid, itaconic acid, maleic acid, methylmaleic acid, fumaric acid, methylfumaric acid, acetylene dicarboxylic 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, galactaric acid, pimelic acid, suberic acid, perfluorosuberic acid, 3,3,6,6-tetramethylsuberic acid, azelaic acid, sebacic acid, perfluoro Sebacic acid, brassic acid, dodecyl dical Aliphatic dicarboxylic acids, such as tridecyldicarboxylic acid and tetradecyldicarboxylic acid; cycloalkyldicarboxylic acids (eg, 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid), 1,4- (2- (dicarboxylic acid) Norbornene) dicarboxylic acid, 5-norbornene-2,3-dicarboxylic acid (hymic acid), adamantanedicarboxylic acid, alicyclic dicarboxylic acids such as spiroheptanedicarboxylic acid; phthalic acid, isophthalic acid, dithioisophthalic acid, methylisophthalic acid, Dimethyl isophthalic acid, chloroisophthalic acid, dichloroisophthalic acid, terephthalic acid, methylterephthalic acid, dimethylterephthalic acid, chloroterephthalic acid, bromoterephthalic acid, naphthalene dicarboxylic acid, oxofluorinated carboxylic acid, anthracene dicarboxylic acid Bonic acid, biphenyl dicarboxylic acid, biphenylene dicarboxylic acid, dimethyl biphenylene dicarboxylic acid, 4,4 ′ ′-p-telephenylene dicarboxylic acid, 4,4 ′ ′-p-quarrel phenyl dicarboxylic acid, bibenzyl dicarboxylic acid, azobenzene dicarboxylic acid, Homophthalic acid, phenylenediacetic acid, phenylenedipropionic acid, naphthalenedicarboxylic acid, naphthalenedipropionic acid, biphenyldiacetic acid, biphenyldipropionic acid, 3,3 '-[4,4'-(methylenedi-p-biphenylene) dipropionate Aromatic dicarboxylic acids such as acid, 4,4'-bibenzyl diacetic acid, 3,3 '(4,4'-bibenzyl) dipropionic acid, oxydi-p-phenylene diacetic acid, etc .; any of the polyvalent carboxylic acids mentioned above Acid anhydrides; esters of any of the polyvalent carboxylic acids mentioned above (E.g. alkyl esters). It may be a monoester, a diester or the like. And the like; acid halides (eg, dicarboxylic acid chlorides) corresponding to any of the polyvalent carboxylic acids described above; and the like.

  Preferable examples of the compound which can be adopted as the polyvalent carboxylic acid component include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid and naphthalene dicarboxylic acid and acid 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 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 the compound which can be adopted as the polyhydric alcohol component include ethylene glycol, propylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol Neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 3-methylpentanediol, diethylene glycol, 1,4-cyclohexanedimethanol, 3-methyl-1,5-pentanediol, 2-methyl- Diols such as 1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, xylylene glycol, hydrogenated bisphenol A, bisphenol A Can be mentioned. Other examples include alkylene oxide adducts of these compounds (e.g., ethylene oxide adducts, propylene oxide adducts, etc.).

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

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

  The antistatic layer (top coat layer) is a resin other than polyester resin (for example, acrylic resin) as a binder as long as the performance (for example, performance such as antistatic property) of the surface protective film disclosed herein is not significantly impaired. It may further contain one or more resins selected from resins, acrylic resin, acrylic styrene resin, acrylic silicone resin, silicone resin, polysilazane resin, polyurethane resin, fluorocarbon resin, polyolefin resin and the like. In a preferred embodiment of the technology disclosed herein, the binder of the antistatic layer consists essentially of a polyester resin. For example, the antistatic layer whose ratio of the polyester resin to a binder is 98-100 mass% is preferable. The proportion of the binder in the entire antistatic layer can be, for example, 50 to 95% by mass, and usually 60 to 90% by mass is suitable.

<Lubricant>
The antistatic layer (top coat layer) in the art disclosed herein is a preferred embodiment using fatty acid amide as a lubricant. By using a fatty acid amide as a lubricant, the surface of the antistatic layer is further subjected to release treatment (for example, a treatment to apply and dry a known release treatment agent such as a silicone release agent or a long chain alkyl release agent) Even in the embodiment not applied, since it is possible to obtain an antistatic layer (top coat layer) having both sufficient slipperiness and print adhesion, it can be a preferable embodiment. Thus, such an aspect that the surface of the antistatic layer is not further subjected to peeling treatment can prevent whitening due to the peeling treatment agent (for example, whitening due to storage under heating and humidifying conditions) in advance. It is preferable in point. Moreover, it is advantageous also from the point of solvent resistance.

  Specific examples of the fatty acid amide include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, hydroxystearic acid amide, oleic acid amide, erucic acid amide, N-oleyl palmitic acid amide, N-stearyl stearic acid Amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl erucic acid amide, methylol stearic acid amide, methylene bis stearic acid amide, ethylene bis capric acid amide, ethylene bis lauric acid amide, ethylene bis stearic acid Amide, ethylenebishydroxystearic acid amide, ethylenebisbehenic acid amide, hexamethylenebisstearic acid amide, hexamethylenebisbehenic acid amide, hexamethylene hydroxystearic acid De, N, N'-distearyl adipamide, N, N'-distearyl sebacic acid amide, ethylene bis oleic acid amide, ethylene bis erucic acid amide, hexamethylene bis oleic acid amide, N, N 'dioleyl Adipic acid amide, N, N'-dioleyl sebacic acid amide, m-xylylene bis-stearic acid amide, m-xylylene bis-hydroxystearic acid amide, N, N'-stearyl isophthalic acid 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 entire antistatic layer may be 1 to 50% by mass, and usually 5 to 40% by mass. If the content of the lubricant is too small, the slipperiness tends to be reduced. If the content of the lubricant is too large, the print adhesion may be reduced.

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

<Crosslinking agent>
The said antistatic layer is characterized by containing an isocyanate type crosslinking agent as a crosslinking agent. By using the above-mentioned isocyanate crosslinking agent, it is possible to fix water-soluble polyaniline sulfonic acid, which is an essential component when forming the antistatic layer, in the binder, to be excellent in water resistance, and further to improve print adhesion etc. The effect can be realized.

  Moreover, it is a preferable aspect to use a stable blocked isocyanate type crosslinking agent also in aqueous solution as said isocyanate type crosslinking agent. Specific examples of the blocked isocyanate-based crosslinking agent include isocyanate-based crosslinking agents that can be used in the preparation of general pressure-sensitive adhesive layers and antistatic layers (top coat layers) (for example, used in pressure-sensitive adhesive layers described later) Isocyanate compounds (isocyanate crosslinking agents), alcohols, phenols, thiophenols, amines, imides, oximes, lactams, active methylene compounds, mercaptans, imines, ureas, diaryl compounds And those blocked with sodium bisulfite etc. can be used.

  The antistatic layer in the technology disclosed herein may, if necessary, contain other antistatic components, antioxidants, colorants (pigments, dyes, etc.), flowability modifiers (thixotropes, thickeners, etc.), Additives such as a coalescent, surfactant (defoaming agent etc.), preservative, etc. may be contained.

<Formation of antistatic layer>
The antistatic layer (top coat layer) is a liquid composition (antistatic layer) formed by dissolving essential components such as the conductive polymer component and the like and additives used as needed in an appropriate solvent (such as water) The coating material (antistatic agent composition) of the present invention can be suitably formed by the method including application to a substrate. For example, a method may be preferably adopted in which the coating material is applied to the first surface of the substrate and dried, and curing treatment (heat treatment, ultraviolet light treatment, and the like) is performed as necessary. The NV (nonvolatile content) of the coating material can be, for example, 5% by mass or less (typically 0.05 to 5% by mass), and usually 1% by mass or less (typically 0.10 to 10%). It is suitable to set it as 1 mass%). When forming a small thickness antistatic layer, it is preferable to make NV of the said coating material into 0.05-0.50 mass% (for example, 0.10-0.40 mass%), for example. By using such a low NV coating material, a more uniform antistatic layer can be formed.

  As a solvent which comprises the coating material for antistatic layer formation, what can stably melt | dissolve the formation component of antistatic layer is preferable. Such solvent may be an organic solvent, water, or a mixed solvent thereof. Examples of the organic solvent include esters such as ethyl acetate; ketones such as methyl ethyl ketone, acetone and cyclohexanone; cyclic ethers such as tetrahydrofuran (THF) and dioxane; aliphatic or alicyclic such as n-hexane and cyclohexane Hydrocarbons; Aromatic hydrocarbons such as toluene, xylene and the like; Aliphatic or alicyclic alcohols such as methanol, ethanol, n-propanol, isopropanol, cyclohexanol and the like; alkylene glycol monoalkyl ethers (eg ethylene glycol monomethyl ether One or more selected from glycol ethers such as ethylene glycol monoethyl ether) and dialkylene glycol monoalkyl ether; and the like can be used. In a preferred embodiment, the solvent of the coating material is water or a mixed solvent containing water as a main component (for example, a mixed solvent of water and ethanol).

<Properties of Antistatic Layer>
The thickness of the antistatic layer in the art disclosed herein is typically 3 to 500 nm, preferably 3 to 100 nm, more preferably 3 to 60 nm). When the thickness of the antistatic layer is too small, it becomes difficult to form the antistatic layer uniformly (for example, in the thickness of the antistatic layer, the variation in the thickness depending on the location becomes large), and hence the appearance of the surface protective film May be prone to unevenness. On the other hand, if it is too thick, the properties (optical properties, dimensional stability, etc.) of the substrate may be affected.

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 or more. It is less than 1.0 × 10 ⁸ and less than 5.0 × 10 ¹⁰ , more preferably 1.0 × 10 ⁹ or more and less than 2.0 × 10 ¹⁰ . The surface protection film exhibiting a surface resistance value within the above range can be suitably used as a surface protection film used in, for example, the processing or transport process of an article that disfavors static electricity, such as a liquid crystal cell or a semiconductor device. Moreover, the surface protection film which shows the surface resistance value in the said range mounts a polarizing plate above a touch panel sensor, and even in the state which stuck the surface protection film on the said polarizing plate, it may perform operation confirmation. Yes, it will be useful. The surface resistance value can be calculated from the surface resistance value measured in an atmosphere at 23 ° C. and 50% RH using a commercially available insulation resistance measuring device.

  The surface protection 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 has an identification number or the like of an adherend to be protected in the process of 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 attached. It is suitable for describing and displaying on the surface protective film. Therefore, it is preferable that it is a surface protection film excellent in printability. For example, it is preferable that the solvent is alcohol-based and has high printability to oil-based inks of the type containing a pigment. Further, it is preferable that the printed ink is difficult to be removed due to rubbing and transfer (that is, excellent in print adhesion). The surface protective film disclosed herein should also have a solvent resistance that does not produce a noticeable change in appearance when wiping the print with alcohol (eg, ethyl alcohol) when correcting or erasing the print. preferable.

  The surface protective film disclosed herein may be practiced in an embodiment including other layers in addition to the substrate, the pressure-sensitive adhesive layer, and the antistatic layer. Examples of the arrangement of the “other layer” include between the first surface (rear surface) of the substrate and the antistatic layer, between the second surface (front surface) of the substrate and the pressure-sensitive adhesive layer, and the like. The layer disposed between the back surface of the substrate and the antistatic layer may be, for example, a layer containing an antistatic component (the above-described antistatic layer). The layer disposed between the front surface of the substrate and the pressure-sensitive adhesive layer may be, for example, an undercoat layer (an anchor layer), an antistatic layer or the like which enhances the anchoring property of the pressure-sensitive adhesive layer to the second surface. It may be a surface protection film having a configuration in which the antistatic layer is disposed on the front surface of the substrate, the anchor layer is disposed on the antistatic layer, and the pressure-sensitive adhesive layer is disposed thereon.

<Pressure-sensitive adhesive layer>
The surface protection film of the present invention has the pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive composition, and the pressure-sensitive adhesive composition is a (meth) acrylic polymer and a poly It is characterized by containing an ether compound and containing 0.03 to 14 parts by mass of the polyether compound with respect to 100 parts by mass of the (meth) acrylic polymer.

  The said (meth) acrylic-type polymer can use the (meth) acrylic-type monomer which has a C1-C14 alkyl group as a raw material monomer which comprises this. As said (meth) acrylic-type monomer, 1 type (s) or 2 or more types can be used as a main component. By using the (meth) acrylic monomer having an alkyl group having 1 to 14 carbon atoms, it becomes easy to control the adhesion to the adherend (object to be protected) to a low level, and it is easy to peel off lightly or re-peel A surface protection film with 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 methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate and s-butyl (meth) acrylate. ) Acrylate, t-Butyl (meth) acrylate, isobutyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl ( Meta) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-dodecyl (meth) acrylate, n-tridecyl (meth) acrylate, n-tetradecyl (meth) acrylate etc. Be

  Among them, in the surface protection film of the present invention, 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, etc. having 6 to 14 carbon atoms Preferred are (meth) acrylic monomers having an alkyl group. In particular, by using a (meth) acrylic monomer having an alkyl group having 6 to 14 carbon atoms, it becomes easy to control the adhesive strength to the adherend low, and the removability becomes excellent.

  In particular, it is preferable to contain 50 mass% or more of (meth) acrylic monomers having an alkyl group having 1 to 14 carbon atoms with respect to 100 mass% of the total amount of monomer components constituting the (meth) acrylic polymer. More preferably, it is 60 mass% or more, More preferably, it is 70 mass% or more, Most preferably, it is 80-93 mass%. When the amount is less than 50% by mass, the wettability of the pressure-sensitive adhesive composition and the cohesion of the pressure-sensitive adhesive layer are deteriorated, which is not preferable.

  Moreover, in the pressure-sensitive adhesive composition of the present invention, the (meth) acrylic polymer preferably contains a (meth) acrylic monomer having a hydroxyl group as a raw material monomer. As a (meth) acrylic-type monomer which has the said hydroxyl group, 1 type (s) or 2 or more types can be used as a main component.

  The use of the (meth) acrylic monomer having a hydroxyl group makes it easy to control the crosslinking of the pressure-sensitive adhesive composition, which in turn makes it easy to control the balance between the improvement of wettability by flow and the reduction of adhesion at peeling. Become. Furthermore, unlike carboxyl groups and sulfonate groups that generally act as crosslinking sites, hydroxyl groups have an appropriate interaction when an ionic compound or the like is used as an antistatic component, and therefore, they have antistatic properties. Also in the aspect, it can be used suitably.

  As the (meth) acrylic monomer having a hydroxyl group, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) Acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxy lauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) methyl acrylate, N-methylol (meth) acrylamide and the like. . In particular, by using a (meth) acrylic monomer having an alkyl group and having a hydroxyl group having 4 or more carbon atoms, light peeling at high speed peeling becomes easy, which is preferable.

  The hydroxyl group-containing (meth) acrylic monomer is preferably contained in an amount of 15 parts by mass or less, and more preferably 100 parts by mass of the (meth) acrylic monomer having an alkyl group having 1 to 14 carbon atoms 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. Within the above range, the balance between the wettability of the pressure-sensitive adhesive composition and the cohesion of the resulting pressure-sensitive adhesive layer can be easily controlled, which is preferable.

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

  As the (meth) acrylic monomer having the alkyl group having 1 to 14 carbon atoms used in the (meth) acrylic polymer, and the other polymerizable monomers other than the (meth) acrylic monomer having the hydroxyl group And (meth) acrylic monomers having a carboxyl group can be used.

  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, relative to 100 parts by mass of the (meth) acrylic monomer having an alkyl group having 1 to 14 carbon atoms, and 3 parts by mass It is more preferably part or less, still more preferably 1 part by mass or less, and most preferably 0.005 to 0.5 parts by mass. When it exceeds 5 parts by mass, many acid functional groups such as carboxyl group having a large polar action exist, and, for example, when an ionic compound is blended as an antistatic component, the acid compound such as carboxyl group is added to the ionic compound. The interaction of the groups interferes with ion conduction, which lowers the conduction efficiency, which may make it impossible to obtain sufficient antistatic properties, which is not preferable.

  Furthermore, the (meth) acrylic monomer having an alkyl group having 1 to 14 carbon atoms, the (meth) acrylic monomer having a hydroxyl group, and the carboxyl group (meth) used in the (meth) acrylic polymer Other polymerizable monomers other than acrylic monomers can be used without particular limitation as long as the characteristics of the present invention are not impaired. For example, cohesive force / heat resistance improving component such as cyano group-containing monomer, vinyl ester monomer, aromatic vinyl monomer, amide group-containing monomer, imide group-containing monomer, amino group-containing monomer, epoxy group-containing monomer, N-acryloyl morpholine The component which has a functional group which works as a tackiness improvement and a crosslinking base point, such as a vinyl ether monomer, can be used suitably. These polymerizable monomers may be used alone or in combination of two or more.

  Examples of cyano group-containing monomers include acrylonitrile and methacrylonitrile.

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

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

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

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

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

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

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

  In the present invention, (meth) acrylic monomers having an alkyl group having 1 to 14 carbon atoms, (meth) acrylic monomers having a hydroxyl group, and other polymerizable monomers other than (meth) acrylic monomers having a carboxyl group It is preferable that it is 0-20 mass parts with respect to 100 mass parts of (meth) acrylic-type monomers which have the said C1-C14 alkyl group, and it is more preferable that it is 0-10 mass parts. When the ionic compound is used as an antistatic agent by using the above-mentioned other polymerizable monomer within the above-mentioned range, properly adjusting the good interaction with the ionic compound and the good removability. Can.

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

  The glass transition temperature (Tg) of the (meth) acrylic polymer is preferably 0 ° C. or less, more preferably −10 ° C. or less (usually −100 ° C. or more). When the glass transition temperature is higher than 0 ° C., the polymer is difficult to flow, for example, the wetting to the polarizing plate becomes insufficient and tends to cause the swelling generated between the polarizing plate and the pressure-sensitive adhesive layer of the surface protective film. There is. In particular, by setting the glass transition temperature to −61 ° C. or less, a pressure-sensitive adhesive layer excellent in wettability to a polarizing plate and light releasability can be easily obtained. In addition, the glass transition temperature of a (meth) acrylic-type polymer can be adjusted in the said range by changing the monomer component and composition ratio to be used suitably.

  The polymerization method of the (meth) acrylic polymer is not particularly limited, and the polymerization can be carried out by a known method such as solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization, etc. Solution polymerization is a more preferable embodiment in terms of characteristics such as low contamination to an adherend (object to be protected). Further, the polymer to be obtained may be any of random copolymer, block copolymer, alternating copolymer, graft copolymer and the like.

  The solution polymerization method is not particularly limited, and examples thereof include a method of dissolving the monomer component, a polymerization initiator and the like in a solvent, heating and polymerizing to obtain an acrylic polymer solution containing an acrylic polymer. .

  Various common solvents can be used as a solvent used for the said solution polymerization method. As such solvent (polymerization solvent), for example, aromatic hydrocarbons such as toluene, benzene and xylene; esters such as ethyl acetate and n-butyl acetate; aliphatic carbonization such as n-hexane and n-heptane Hydrogens; Alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; and Organic solvents such as ketones such as methyl ethyl ketone and methyl isobutyl ketone. The said solvent can be used individually or in combination of 2 or more types.

  The polymerization initiator is not particularly limited, and examples thereof include peroxide-based polymerization initiators and azo-based polymerization initiators. The peroxide-based polymerization initiator is not particularly limited, and examples thereof include peroxy carbonate, ketone peroxide, peroxy ketal, hydroperoxide, dialkyl peroxide, diacyl peroxide, peroxy ester and the like. More specifically, benzoyl peroxide, t-butyl hydroperoxide, di-t-butyl peroxide, t-butyl peroxybenzoate, dicumyl peroxide, 1,1-bis (t-butyl peroxy)- 3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclododecane and the like. The azo 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-methyl propiyl Amidine) disulfate, 2,2'-azobis (N, N'-dimethylene isobutyl amidine) hydrochloride, 2,2'-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate Etc. The said polymerization initiator can be used individually or in combination of 2 or more types.

  Although the compounding ratio of the said polymerization initiator is not specifically limited, For example, 0.01-5 mass parts is preferable with respect to the monomer component whole quantity (100 mass parts) which comprises the said (meth) acrylic-type polymer, and more preferable. Is 0.05 to 3 parts by mass.

  Although it does not specifically limit as heating temperature at the time of superposing | polymerizing by heating in the said solution polymerization method, For example, 50-80 degreeC is mentioned. The heating time is not particularly limited, and may be, for example, 1 to 24 hours.

<Polyether compound>
The pressure-sensitive adhesive composition preferably contains a polyether compound, and the polyether compound is preferably a surfactant. The pressure-sensitive adhesive composition can impart an appropriate antistatic property by blending a polyether compound in a specific ratio, and furthermore, the surface filler film is peeled off to the interlayer filler on the surface of the adherend. It is possible to secure sex and is useful.

  As specific examples of the polyether compound, for example, polyoxyalkylene alkylamine, polyoxyalkylene diamine, polyoxyalkylene fatty acid ester, polyoxyalkylene sorbitan fatty acid ester, polyoxyalkylene alkyl phenyl ether, polyoxyalkylene alkyl ether, poly Nonionic surfactants such as oxyalkylene alkyl allyl ether and polyoxyalkylene alkyl phenyl allyl ether; polyoxyalkylene alkyl ether sulfuric acid ester salt, polyoxyalkylene alkyl ether phosphoric acid ester salt, polyoxyalkylene alkyl phenyl ether sulfuric acid ester salt Anionic surfactants such as polyoxyalkylene alkyl phenyl ether phosphate ester salts; other, poly Cationic surfactants or zwitterionic surfactants having a xyalkylene chain (polyalkylene oxide chain), polyether compounds (including their derivatives) having a polyoxyalkylene chain, acrylic compounds having a polyoxyalkylene chain And derivatives thereof and the like. 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 PEG-PPG-PEG A block copolymer etc. are mentioned. As the derivative of the polyether compound having a polyoxyalkylene chain, an oxypropylene group-containing compound whose end is etherified (PPG monoalkyl ether, PEG-PPG monoalkyl ether, etc.), an oxypropylene group whose end is acetylated Containing compounds (terminally acetylated PPG etc.) and the like can be mentioned.

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

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

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

  Furthermore, as other monomer components other than the (meth) acrylic acid alkylene oxide, a carboxyl group-containing (meth) acrylate, a phosphoric acid group-containing (meth) acrylate, a cyano group-containing (meth) acrylate, vinyl esters, and an aromatic vinyl compound Acid anhydride group-containing (meth) acrylate, hydroxyl group-containing (meth) acrylate, amide group-containing (meth) acrylate, amino group-containing (meth) acrylate, epoxy group-containing (meth) acrylate, N-acryloyl morpholine, vinyl ethers It is also possible to use 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 (meth) acrylic polymer as the base polymer and the antistatic component is improved, bleeding to the adherend is suitably suppressed, and contamination is low. A pressure-sensitive adhesive composition is obtained. Among them, when a PPG-PEG-PPG block copolymer is used, an adhesive excellent in low stain resistance can be obtained. The weight of the (poly) ethylene oxide chain in the entire polyether compound is preferably 5 to 90% by mass, more preferably 5 to 85% by mass, and still more preferably 5 to 80, as the polyethylene oxide chain-containing compound. % By weight, most preferably 5 to 75% by weight.

  Furthermore, as a specific example in the case where the polyether compound is a surfactant, for example, an anionic reactive surfactant having a (meth) acryloyl group or an allyl group, a nonionic reactive surfactant, a cationic surfactant Reactive surfactant etc. are mentioned.

  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 The same or different represents an alkylene group having 1 to 6 carbon atoms, and the average addition mole number m and n is 0 to 40, provided that (m + n) is 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。］。

[R ₁ in Formula (A2) represents hydrogen or a methyl group, R ₂ and R ₇ are the same or different, each represents 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, and the average addition mole number m and n is 0 to 0. 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 addition mole number 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 having 1 to 30 carbon atoms or an acyl group, R ₃ and R ₄ are the same or different, 6 represents an alkylene group, X represents an anionic hydrophilic group, and the average addition mole number m and n are 0 to 40, provided that (m + n) is 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 the 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, and X represents an anionic hydrophilic group, an average addition mole 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 A C1-C6 alkylene group is represented, X represents an anionic hydrophilic group, and average addition mole number n represents the number of 3-40. ].

［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 the 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 M represents a hydrogen, an alkali metal, an ammonium group, or an alkanol ammonium group, and the average addition mole number m and n represent 0 to 40, provided that (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。］

[R ₁ and R _{5 in} Formula (A8) are the same or different and each represents a hydrogen or methyl group, R ₂ and R ₄ are the same or different, each represents an alkylene group having 1 to 6 carbon atoms, and R ₃ is 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 addition mole number 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 the 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 added mole number 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。］。

[R ₁ , R ₂ and R ₃ in the Formula (A10) are the same or different and each represents a hydrogen or methyl group, and R ₄ is a hydrocarbon group having 0 to 30 carbon atoms (in the case of 0 carbon atoms, R ₄ And R ₅ and R ₆ are the same or different and each represents an alkylene group having 1 to 6 carbon atoms, X represents an anionic hydrophilic group, and the average addition mole number m and n is 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. As an anionic hydrophilic group, what is represented by following formula (a1)-(a2) is mentioned.

［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 Formula (a1) represents hydrogen, an alkali metal, an ammonium group, or an alkanolammonium 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 alkanolammonium group. ]

  Examples of nonionic reactive surfactants 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 having 1 to 30 carbon atoms or an acyl group, R ₃ and R ₄ are the same or different, 6 represents an alkylene group, and the average addition mole number m and n is 0 to 40, provided that (m + n) is 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 the formula (N2), R ₁ represents hydrogen or a methyl group, R ₂ , R ₃ and R ₄ are the same or different and each represents an alkylene group having 1 to 6 carbon atoms, and the average addition mole number n, m, And l is 0 to 40, and represents 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 represents a hydrocarbon having 1 to 30 carbon atoms A group or an acyl group is represented, and the average addition mole number m and n is 0 to 40, provided that (m + n) is 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。］

[R ₁ and R ₂ in the formula (N 4) 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 is an alkylene having 1 to 6 carbon atoms Represents a group, and the average addition mole number 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。］

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

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

  The number average molecular weight (Mn) of the polyether compound is suitably 50,000 or less, preferably 200 to 30,000, more preferably 200 to 10,000, and usually 200 to 5,000. . When Mn is more than 50,000, the compatibility with the (meth) acrylic polymer as the base polymer is reduced, and the pressure-sensitive adhesive layer tends to be whitened. If the Mn is less than 200, contamination with the polyether compound may easily occur. In addition, Mn means the value of polystyrene conversion obtained by gel permeation chromatography (GPC) here.

  Further, specific examples of the polyether compounds as commercial products include, for example, Adeka Pluronic 17R-4, Adeka Pluronic 25 R-1, Adeka Pluronic 25 R-2, Adeka Pluronic L-23, Adekaria Soap ER-10, and Adekaria. Soap NE-10 (all manufactured by Adeka), Emulgen 120, Latemur PD-420, Latemur PD-430 (all manufactured by Kao Corp.), Surfynol 420, Surfynol 485 (all, Nisshin) Chemical Industries), Aqualon HS-10: Hythenol N-08, Neugen XL-40, Antifloss M-9, Epan 410, Aqualon KH-10, Aqualon RN-20, Hythenol NF-08, Plysurf A 212 C, (These are all Dai-ichi Kogyo Seiyaku Co., Ltd.), PEG 40 0, PEG 600, New Pole PE-34, Sannix PP 200 (all, all Sanyo Chemical Industries, Ltd.), Blenmer PME-400, Blenmer PME-1000, Blenmer 50 POEP-800 B (all, all by NOF Corporation), etc. It can be mentioned.

  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 100 parts by mass of the (meth) acrylic polymer. It is 0.05 to 12 parts by mass, and most preferably 0.05 to 10 parts by mass. If the compounding amount is too small, adequate antistatic property (antistatic effect) can not be obtained, and the wettability to the interlayer filler on the adherend surface after peeling off the surface protective film may not be secured in some cases. . On the other hand, when the amount is too large, the contamination with 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 alkali metal salts and / or ionic liquids. By containing these ionic compounds, excellent antistatic properties can be imparted. As described above, the pressure-sensitive adhesive layer (using the antistatic component) formed by crosslinking the pressure-sensitive adhesive composition containing the antistatic component is an adherend (for example, a polarizing plate) which is not antistatic when peeled off. (1) can be prevented, and the surface protection film with reduced contamination to the adherend can be obtained. For this reason, it becomes very useful as an antistatic surface protective film in the technical field related to optical and electronic parts in which charging and contamination are particularly serious problems.

<Crosslinking agent>
In the surface protection film of the present invention, the pressure-sensitive adhesive composition preferably contains a crosslinking agent. In the present invention, the pressure-sensitive adhesive layer can be formed using the pressure-sensitive adhesive composition. For example, a surface protection film (pressure-sensitive adhesive layer) more excellent in heat resistance can be obtained by appropriately adjusting and crosslinking the structural unit, the constituent ratio, the selection of the crosslinking agent, and the addition ratio of the (meth) acrylic polymer. be able to.

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

  Examples of the isocyanate compound include aliphatic polyisocyanates such as trimethylene diisocyanate, butylene diisocyanate, hexamethylene diisocyanate (HDI) and dimer acid diisocyanate, and lipids such as cyclopentylene diisocyanate, cyclohexylene diisocyanate and isophorone diisocyanate (IPDI). Aromatic isocyanates such as cyclic isocyanates, 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate (XDI), allophanate bond, biuret bond, isocyanurate bond, uretdione bond of the isocyanate compound , Urea bond, carbodiimide bond, uretone imine bond, oxadiazine trione bond, etc. More denatured polyisocynate modified products thereof. For example, as commercially available products, Takenate 300S, Takenate 500, Takenate D 165 N, Takenate D 178 N (above, Takeda Yakuhin Kogyo Co., Ltd.), Semidur T 80, Semidur L, Desmodur N 3400 (above, Sumika Bayer Urethane Co., Ltd.) And Millionate MR, Millionate MT, Coronate L, Coronate HL, Coronate HX (manufactured by Nippon Polyurethane Industry Co., Ltd.) and the like. These isocyanate compounds may be used alone or in combination of two or more. It is also possible to use a bifunctional isocyanate compound and a trifunctional or higher isocyanate compound in combination. By using a crosslinking agent in combination, it is possible to achieve both adhesiveness and repulsion resistance (adhesion to a curved surface), and it is possible to obtain a surface protection 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 Co., Ltd.) and 1,3-bis (N, N-di). Glycidyl aminomethyl) cyclohexane (trade name: TETRAD-C, manufactured by Mitsubishi Gas Chemical Co., Ltd.) and the like.

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

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

  The content of the crosslinking agent used in the present invention is, for example, preferably 0.01 to 10 parts by mass, preferably 0.1 to 8 parts by mass, with respect to 100 parts by mass of the (meth) acrylic polymer. It is more preferably contained, still 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 may be insufficient, the cohesive force of the obtained pressure-sensitive adhesive layer may be reduced, and sufficient heat resistance may not be obtained. It tends to cause adhesive residue. On the other hand, when the content exceeds 10 parts by mass, the cohesion of the polymer is large, the fluidity is reduced, and the wetting to the adherend (for example, the polarizing plate) becomes insufficient, and the adherend and the adhesive It tends to be a cause of the swelling generated between the layer (pressure-sensitive adhesive composition layer). Furthermore, when the amount of the crosslinking agent is large, the peeling chargeability tends to be lowered.

<Crosslinking catalyst>
The pressure-sensitive adhesive composition may further contain a crosslinking catalyst for more effectively promoting any of the above-mentioned crosslinking reactions. As such a crosslinking catalyst, for example, tin-based catalysts such as dibutyltin dilaurate and dioctyltin dilaurate, tris (acetylacetonato) iron, tris (hexane-2,4-dionato) iron, tris (heptane-2,4-dionato) Iron, tris (heptane-3,5-dionato) iron, tris (5-methylhexane-2,4-dionato) iron, tris (octane-2,4-dionato) iron, tris (6-methylheptane-2, 4-dionato) iron, tris (2,6-dimethylheptane-3,5-dionato) iron, tris (nonane-2,4-dionato) iron, tris (nonane-4,6-dionato) iron, tris (2 2,2,6,6-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 (propionyl acetate methyl) iron, Tris (propionyl acetate ethyl) iron, Tris (propionyl acetate-n-propyl) iron Tris (propionyl acetate isopropyl) iron, tris (propionyl acetate-n-butyl) iron, tris (propionyl acetate-sec-butyl) iron, tris (propionyl acetate-tert-butyl) iron, tris (benzyl acetoacetate) iron, Tris (dimethyl malonate) iron, tris (diethyl malonate) iron, trimethoxyiron, Iron-based catalysts such as triethoxy iron, triisopropoxy iron and ferric chloride can be used. These crosslinking catalysts may be used alone or in combination of two or more.

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

<Crosslinking retarder>
The pressure-sensitive adhesive composition may further contain a crosslinking retarder. The crosslinking retarder is not particularly limited, and examples thereof include β-ketoesters such as methyl acetoacetate, ethyl acetoacetate, octyl acetoacetate, oleyl acetoacetate, lauryl acetoacetate, stearyl acetoacetate, acetylacetone, and 2,4- Examples include β-diketones such as hexanedione, benzoylacetone and the like. Among them, acetylacetone can be used. The said crosslinking retarder can be used individually or in combination of 2 or more types.

  The content (use amount) of the crosslinking retarder is not particularly limited, but for example, 0.1 to 10 parts by mass is preferable, and 0.1 to 5 parts by mass with respect to 100 parts by mass of the solvent (when converted to). Part is 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. As said solvent, the solvent used for the above-mentioned solution polymerization method is mentioned, for example. 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 solvents in the pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer of the present invention can be used alone or in combination of two or more.

  Furthermore, 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. It can add suitably according to the use which uses.

<Pressure-sensitive adhesive layer / surface protection film>
The surface protective film for a touch panel according to the present invention is formed by forming the pressure-sensitive adhesive layer on the second surface of the substrate from a pressure-sensitive adhesive composition, in which case crosslinking of the pressure-sensitive adhesive composition is Although it is common to carry out after the application of the pressure-sensitive adhesive composition, it is also possible to transfer the pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition after crosslinking onto 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 the substrate, and the polymerization solvent and the like are dried and removed to form the pressure-sensitive adhesive layer. It is produced by forming it on top. Thereafter, curing may be performed for the purpose of adjusting the component transfer of the pressure-sensitive adhesive layer, adjusting the crosslinking reaction, and the like. Moreover, when apply | coating an adhesive composition on a base material and producing a surface protection film, 1 or more types of solvents other than a polymerization solvent are said in the said adhesive composition so that it can apply | coat uniformly on a base material. You may add it newly.

  Moreover, as a formation method of the adhesive layer at the time of manufacturing the surface protection film of this invention, the well-known method used for manufacture of adhesive tapes is used. Specific examples thereof include roll coating, gravure coating, reverse coating, roll brushing, spray coating, air knife coating, and extrusion coating using a die coater.

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

  The total thickness of the surface protective film of the present invention is preferably 1 to 400 μm, more preferably 10 to 200 μm, and still more preferably 20 to 100 μm. It is excellent in adhesive property (removability, adhesiveness etc.), workability | operativity, an appearance characteristic as it is in the said range, and it becomes a preferable aspect. In addition, the said total thickness means the sum total of the thickness containing all the layers, such as a base material, an adhesive layer, and an 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 as necessary.

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

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

<Optical member>
It is preferable that the optical member mounted in the touch panel of this invention is protected by the said surface protection film for touch panels. The surface protective film is excellent in the antistatic property and the temporal stability of the peeling voltage, so that the operation of the touch panel can be confirmed, and the wettability to the interlayer filler on the adherend surface after peeling the surface protective film is also excellent. It can be used for surface protection application (surface protection film) 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 and the like in which static electricity is easily generated, it becomes very useful in antistatic applications in the technical fields related to optical and electronic parts where charging becomes a particularly serious problem.

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

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

<Measurement of Weight Average Molecular Weight (Mw)>
The weight average molecular weight (Mw) was measured using Tosoh Corp. GPC apparatus (HLC-8220GPC). The measurement conditions are as follows.

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

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

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

<Measurement of surface resistance>
The measurement was performed according to JIS-K-6911 using a resistivity meter (Hiresta UP MCP-HT450 type, manufactured by Mitsubishi Chemical Analytic Co., Ltd.) under an atmosphere of temperature 23 ° C. and humidity 50% RH.
The surface resistance value (Ω / □) in the present invention is preferably 1.0 × 10 10 at the initial stage and at room temperature (23 ° C. × 50% RH) × 1 week (7 days). ⁷ or more and less than 1.0 × 10 ¹¹ , more preferably 1.0 × 10 ⁸ or more and 5.0 × 10 ¹⁰ or less, still more preferably 1.0 × 10 ⁹ or more and 2.0 × 10 ¹⁰ or more Less than. The surface protection film exhibiting a surface resistance value within the above range can be suitably used as a surface protection film used in, for example, the processing or transport process of an article that disfavors static electricity, such as a liquid crystal cell or a semiconductor device. Moreover, the surface protection film which shows the surface resistance value in the said range mounts a polarizing plate above a touch panel sensor, and even in the state which stuck the surface protection film on the said polarizing plate, it may perform operation confirmation. Yes, it will be useful.

<Operation check of touch panel>
Evaluation of the operation check of the touch panel was performed using iPhone 5s (manufactured by Apple Inc.) equipped with the in-cell touch panel. First, the surface protective film was attached on the screen of the iPhone 5s, and when the screen was traced with a finger, the touch panel reacted or was visually observed to confirm operability.
○: When the touch panel responds correctly.
X: The touch panel does not respond correctly.

<Water contact angle>
The surface protective film is attached to the surface of the adherend (hard coat film) at a temperature of 23 ° C and a humidity of 50%, and then put into an autoclave and treated under conditions of a temperature of 50 ° C, a pressure of 5 atm, and a time of 15 minutes. Then, they were allowed to adhere to each other, left to stand at a temperature of 23 ° C. and a humidity of 50% for 12 hours and peeled off. An adherend to which a surface protective film has been applied by a liquid contact method using a water contact angle measurement device (trade name "DM700", manufactured by Kyowa Interface Chemical Co., Ltd.) under an atmosphere of temperature 23 ° C. and humidity 50% RH. About 2.8 μL of a water droplet was dropped on the surface, and an angle formed by the tangent of the adherend surface and the end of the dropped water droplet one second after the dropping was measured to obtain “water contact angle (°)”. The case where the water contact angle was 35 ° or less was evaluated as “(wettability) good (○)”, and the case where the water contact angle was larger than 35 ° was evaluated as “(wettability) defect (x)”.
In addition, the water contact angle of the adherend which did not process at all was 37.2 degrees. That is, the adherend used in the present evaluation is a triacetyl cellulose film having a water contact angle of 37.2 °.

<Wettability of interlayer filler>
The surface protective film is attached to the surface of the adherend at a temperature of 23 ° C. and a humidity of 50%, and then put into an autoclave and treated at a temperature of 50 ° C., a pressure of 5 atm for 15 minutes for a period of 15 minutes. It was left to stand at 23 ° C. and 50% humidity for 12 hours. Thereafter, the adherend to which the surface protective film is attached is cut into a length of 40 mm and a width of 40 mm and attached to a glass plate of 50 mm in length and 50 mm in width, and the glass plate is a spin coater (trade name "K-359SD1") , Manufactured by Kyowa Riken Co., Ltd.). Thereafter, the surface protection film is peeled off from the adherend, and 4 ml of a trade name "SVR 7000 series" (manufactured by Dexerials) is applied as an interlayer filler on the surface of the adherend to which the surface protection film has been attached. The rotation was made to spread the interlayer filler uniformly. After standing for 1 hour at a temperature of 23 ° C. and a humidity of 50%, the distance between the interlayer filler and the edge of the adherend was measured with a ruler.
Moreover, the same measurement was performed using brand name "WORLD ROCK HRJ-21" (made by Kyoritsu Chemical Industries, Ltd.) as an interlayer filler.
Even when using any interlayer filler of "SVR 7000 series" and "WORLD ROCK HRJ-21", the case where the distance repelled from the edge is shorter than 2 mm is "good (○)", either one or both of the layers When the filler was used, the case where the distance repelled from the edge was 2 mm or more was evaluated as "defect (x)". In addition, the to-be-adhered body used by this evaluation is the same as the to-be-adhered body used by evaluation of the said "water contact angle."

<Measurement of Polarizing Plate Peeling Voltage (Polarizing Plate Side)>
The surface protection film 1 according to each example is cut to a size of 70 mm in width and 130 mm in length, and after peeling off the release liner, as shown in FIG. 3, an acrylic plate 10 (manufactured by Mitsubishi Rayon Co., Ltd.) On the surface of a polarizing plate 20 (manufactured by Nitto Denko Corporation, SEG 1423 DU polarizing plate, width: 70 mm, length: 100 mm) bonded to a trade name “Akrylite”, thickness: 1 mm, width: 70 mm, length: 100 mm The other end of the surface protective film 1 was pressed by a hand roller so that 30 mm extended out from the end of the polarizing plate 20.
The sample was left to stand in an environment of 23 ° C. × 50% RH for 1 day, and then set at a predetermined position of a sample fixing stand 30 having a height of 20 mm. The end of the surface protection film 1 protruding 30 mm from the polarizing plate 20 was fixed to an automatic winder (not shown), and peeled off so as to have a peeling angle of 150 ° and a peeling speed of 10 m / min. Potential measuring device 40 (made by Kasuga Electric Co., Ltd., type “KSD-0103”) in which the potential of the surface of the adherend (polarizing plate) generated at this time is fixed at a height of 100 mm from the center of polarizing plate 20 Then, “initial polarizing plate peeling voltage” was measured. The measurement was performed under the environment of 23 ° C. and 50% RH.
In addition, after left in an environment of 23 ° C. × 50% RH for 1 week (7 days), “the polarizing plate peeling voltage with time” was measured in the same manner as “initial polarizing plate peeling voltage”. The measurement was performed under the environment of 23 ° C. × 50% RH.
In addition, a polarizing plate peeling voltage is a peeling voltage which originates in the antistatic layer and the adhesive layer which comprise the surface protection film of this invention, and contributes to antistatic property.
The polarizing plate peeling-off voltage (kV) (absolute value, both initial and with time) 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 a liquid crystal driver or the like can be prevented, which is a preferable embodiment.

<Positiveness of Polarizing Plate>
The surface protective film was cut together with a release liner to a size of 50 mm wide and 80 mm long, 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, SEG 1423 DU polarizing plate) with a hand roller. The film was left in an environment of 23 ° C. × 50% RH for 1 week, and then the surface protective film was peeled off from the adherend by hand. The surface of the adherend after exfoliation is under light (in a normal indoor environment with fluorescent light on the ceiling) and under a dark room fluorescent light (outside light with a light shielding curtain, and only table fluorescent light is used as light) In the environment) to evaluate the state of contamination. Evaluation criteria are as follows.
○: No contamination was observed under bright conditions.
X: When contamination is recognized under bright place.

<Preparation of Acrylic Polymer (A) for Pressure-Sensitive Adhesive Layer>
100 parts by mass of 2-ethylhexyl acrylate (2EHA), 4 parts by mass of 2-hydroxyethyl acrylate (HEA), 2 as a polymerization initiator, in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction pipe, and a cooler 0.2 parts by mass of 2,2'-azobisisobutyronitrile and 157 parts by mass of ethyl acetate are charged, nitrogen gas is introduced while gently stirring, and the liquid temperature in the flask is maintained at around 65 ° C., and polymerization is carried out for 6 hours The reaction was carried out to prepare an acrylic polymer (A) solution (40% by mass). The weight average molecular weight of the acrylic polymer (A) was 540,000, and the glass transition temperature (Tg) was -68 ° C.

Preparation of Acrylic Polymer (B) for Pressure-Sensitive Adhesive Layer
In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet pipe, and a cooler, 100 parts by mass of 2-ethylhexyl acrylate (2EHA), 10 parts by mass of 4-hydroxybutyl acrylate (4HBA), acrylic acid (AA) Charge 0.02 parts by mass, 0.2 parts by mass of 2,2'-azobisisobutyro nitrile as a polymerization initiator, 157 parts by mass of ethyl acetate, introduce nitrogen gas while gently stirring, and introduce liquid in the flask The temperature was kept at around 65 ° C. and polymerization reaction was carried out for 6 hours to prepare an acrylic polymer (B) solution (40% by mass). The weight average molecular weight of the acrylic polymer (B) was 540,000, and the glass transition temperature (Tg) was -67 ° C.

Preparation of aqueous solution for antistatic layer (C)
Polyester resin Vyronal MD-1480 (25% aqueous solution, manufactured by Toyobo Co., Ltd.) as a binder, polyaniline sulfonic acid (aquapass, weight average molecular weight 40,000, manufactured by Mitsubishi Rayon Co., Ltd.) as a conductive polymer, hexamethylene blocked with diisopropylamine as a crosslinking agent Diisocyanate isocyanurate, oleic acid amide as a lubricant, water / ethanol (1/3) mixed solvent, 100 parts by mass of solid content of binder, 75 parts of solid content of conductive polymer, solid content of crosslinking agent 10 parts by mass in amount and 30 parts by mass in solid content of the lubricant were added and thoroughly mixed for about 20 minutes with stirring. In this way, an aqueous solution for NV of about 0.4% antistatic layer (C) was prepared.

Preparation of aqueous solution for antistatic layer (D)
Polyester resin Vyronal 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) An aqueous solution (Bytron P, manufactured by HC Stark) containing 0.8% of (PSS) in a mixed solvent of water / ethanol (1/1), 100 parts by mass of the binder in solid content, and a conductive polymer 50 parts by mass in solid content and 2.5 parts by mass of a melamine based crosslinking agent were added, and stirred for about 20 minutes for thorough mixing. In this way, an aqueous solution for NV about 0.4% of antistatic layer (D) was prepared.

Preparation of Base Material with Antistatic Layer
The antistatic layer (C) is formed on the corona-treated side 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, one side of which (the first side) is corona-treated. Or the aqueous solution of (D) was applied so that the thickness after drying might be 30 nm or 50 nm. The coated material was dried by heating at 130 ° C. for 1 minute to prepare a substrate with an antistatic layer having an antistatic layer on the first surface of the PET film.

Example 1
[Preparation of Acrylic Adhesive Solution]
The acrylic polymer (A) solution (40% by mass) is diluted to 20% by mass with ethyl acetate, and 500 parts by mass of this solution (100 parts by mass of solid content) is an isocyanurate of hexamethylene diisocyanate as a crosslinking agent ( Nippon Polyurethane Industry Co., Ltd., Coronate HX 3 parts by mass (solid content: 3 parts by mass), Crosslinking catalyst: dibutyltin dilaurate (trade name: OL-1, manufactured by Tokyo Fine Chemical Co., Ltd.) (1 mass% ethyl acetate solution) 3 mass Parts (solid content: 0.03 parts by mass), 3 parts by mass of acetylacetone per 100 parts by mass of solvent (when converted) as a crosslinking retarder, and polyethylene glycol as a polyether compound (trade name: PEG 400, number Average molecular weight: 400, 0.05 parts by mass of Sanyo Chemical Industries, Ltd.) is added and mixed and stirred to prepare an acrylic pressure-sensitive adhesive solution. .

[Preparation of surface protection film]
The acrylic pressure-sensitive adhesive solution is applied to the side of the substrate having the antistatic layer (substrate with antistatic layer) opposite to the antistatic layer, and heated at 130 ° C. for 1 minute to a thickness of 15 μm. An adhesive layer was formed. Then, a silicone-treated surface of a polyethylene terephthalate film (25 μm in thickness), which is a separator subjected to silicone treatment on one side, was attached to the surface of the pressure-sensitive adhesive layer to prepare a surface protection film for touch panel.

Examples 2 to 10 and Comparative Examples 1 to 4
A surface protective film was produced in the same manner as in Example 1 based on the contents of the formulations in Tables 1 to 3.

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

The abbreviations in Tables 1 and 3 will be described below.
2EHA: 2-ethylhexyl acrylate HEA: 2-hydroxyethyl acrylate 4HBA: 4-hydroxybutyl acrylate AA: acrylic acid (AA)
Adeka Pululonic 25R-1: Polyoxyethylene-polyoxypropylene block copolymer (made by Adeka, polyether compound)
Surfynol 420: a polyetherate of 2,4,7,9-tetramethyl-5-decyne-4,7-diol (Nishin Chemical Co., Ltd., polyether compound)
Surfynol 485: 2,4,7,9-Tetramethyl-5-decyne-4,7-diol polyetherate (Nishin Chemical Co., Ltd., polyether compound)
Aqualon HS-10: Polyoxyethylene nonylpropenyl phenyl ether ammonium sulfate (Daiichi Kogyo Seiyaku Co., Ltd., polyether compound)
Latem PD-420: polyoxyalkylene alkenyl ether (made by Kao, polyether compound)
PEG 400: polyethylene glycol (number average molecular weight: 400, 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, in all the Examples, the antistatic property and the temporal stability of the peeling charging voltage were excellent, and further, no problem occurred in the operation confirmation of the touch panel, and it was confirmed that it was practical. In addition, it has been confirmed that the wettability and the contamination are also excellent by blending the polyether compound in a specific ratio in the pressure-sensitive adhesive layer.

  On the other hand, in Comparative Example 1, since no polyether compound was used, it was confirmed that the wettability was inferior and the antistatic property was also inferior. In addition, in Comparative Example 2, it was confirmed that the antistatic property was not obtained because the polyether compound was blended only in an amount smaller than the desired ratio. In the comparative example 3, since many polyether compounds were mix | blended, it was confirmed that it is inferior to contamination property. In Comparative Example 4, since the water dispersion type conductive polymer (PEDOT / PSS) is used as a component of the antistatic layer, the surface resistance value is too low, so that the operation of the touch panel can not be confirmed, which is practical. It was confirmed that it was not Moreover, it was confirmed that it was inferior to the time-lapse stability of antistatic property and the peeling charge voltage. Although the details of the reason why such a problem should occur are not clear, it is presumed that the deterioration of the antistatic property occurs as the whole surface protective film based on the deterioration of the antistatic layer.

  The surface protection film disclosed herein is an optical component during production, transport, etc. of an optical member such as a polarizing plate used as a component of a liquid crystal display panel, plasma display panel (PDP), organic electroluminescence (EL) display, etc. It is suitable as a surface protection film for protecting a member. In particular, it is useful as a surface protection film (surface protection film for optics) applied to optical members, such as a polarizing plate mounted in a touch panel of an on-cell system or an in-cell system.

1: Surface protection film 3: Touch panel 10: Acrylic plate 20: Polarizing plate 3
0: Sample fixing base 40: Potential measuring device 11: Antistatic layer 12: Substrate 13: Adhesive layer 31: Polarizing plate 32: Touch sensor 33: Substrate glass 34: Liquid crystal

Claims (6)

A pressure-sensitive adhesive layer formed of a substrate having a first surface and a second surface, an antistatic layer provided on the first surface of the substrate, and a pressure-sensitive adhesive composition on the second surface of the substrate And a surface protection film for a touch panel,
The antistatic layer is formed of an antistatic agent composition containing polyaniline sulfonic 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,
10 to 200 parts by mass of the polyaniline sulfonic acid with respect to 100 parts by mass of the polyester resin,
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,
The surface protection film for a touch panel, comprising 0.03 to 14 parts by mass of the polyether compound with respect to 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. The touch panel according to claim 1 or 2, wherein the conductive polymer component further contains at least one selected from the group consisting of polythiophene, polyaniline, polypyrrole, polyethyleneimine, and allylamine polymers. Surface protection film. The surface protection film for a touch panel according to any one of claims 1 to 3, wherein the polyether compound is a surfactant. The optical member mounted in the touch panel characterized by being protected by the surface protection film for a touch panel according to any one of claims 1 to 4. It is a manufacturing method of the surface protection film for touch panels in any one of Claims 1-4, Comprising: The process of preparing the aqueous solution containing the said antistatic agent composition, and said aqueous solution on the 1st surface of the said base material Applying and drying to prepare an antistatic layer, and a method of producing a surface protection film for a touch panel.

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