TWI567157B - Method for producing antistatic surface protection film, and antistatic surface protection film - Google Patents

Description

Antistatic surface protection film manufacturing method and antistatic surface protection film

The present invention relates to a method for producing an antistatic surface protective film which is bonded to a surface of an optical member such as a polarizing plate, a phase difference plate, or a lens film for a display (hereinafter sometimes referred to as an "optical film"), and an antistatic surface. Protective film. More specifically, the present invention provides a method for producing an antistatic surface protective film which has less contamination to an adherend, has no deterioration over time, and has excellent anti-peeling electrostatic properties, and an antistatic surface protective film.

When manufacturing and transporting optical films such as a polarizing plate, a retardation film, a lens film for a display, an antireflection film, a hard coat film, and a transparent conductive film for a touch panel, and an optical product such as a display using the same, Surface contamination and scratching in the subsequent steps are prevented by bonding the surface protective film to the surface of the optical film. In order to save labor and time after peeling the surface protective film and to improve work efficiency, the surface film may be bonded to the optical film for visual inspection of the optical film as a product. Direct implementation in the state. Conventionally, in order to prevent the adhesion of scratches and dirt in the manufacturing process of an optical product, a surface protective film in which an adhesive layer is provided on one surface of a base film is generally used. The surface protective film is an adhesive layer interposed with a microadhesive force and is bonded to the optical film. The reason why the adhesive layer is set to the micro-adhesive force is that it can be easily peeled off in order to remove the used surface protective film from the surface of the optical film, and to prevent adhesion of the adhesive and remain as The phenomenon of the optical film of the product of the adherend (so-called prevention of the occurrence of adhesive residue).

In the production process of the liquid crystal display panel, the peeling static voltage generated when the surface protective film attached to the optical film is peeled off and removed is destroyed, and the driving IC for controlling the display screen of the liquid crystal display panel is destroyed. The circuit components, as well as the orientation of the liquid crystal molecules, are damaged, although the number of occurrences of these phenomena is small but also occurs. In addition, in order to reduce the power consumption of the liquid crystal display panel, the driving voltage of the liquid crystal material tends to decrease, and accordingly, the breakdown voltage of the driving IC tends to decrease. Recently, it has been required to control the peeling static voltage in the range of +0.7 kV to -0.7 kV. Therefore, in order to prevent defects caused by high peeling static voltage when the surface protective film is peeled off from the optical film as the adherend, a surface protective film using antistatic which contains a static voltage for peeling off has been proposed. The adhesive layer of the agent.

For example, Patent Document 1 discloses a surface protective film using an adhesive composed of an alkyltrimethylammonium salt, a hydroxyl group-containing acrylic polymer, or a polyisocyanate. Further, Patent Document 2 discloses an adhesive composition composed of an ionic liquid and an acrylic polymer having an acid value of 1.0 or less, and an adhesive sheet using the composition. Further, Patent Document 3 discloses an adhesive composition composed of an acrylic polymer, a polyether polyol compound, an alkali metal salt treated with an anion-adsorbing compound, and a surface using the composition. Protective film. Further, Patent Document 4 discloses an adhesive composition composed of an ionic liquid, an alkali metal salt, a polymer having a glass transition temperature of 0 ° C or lower, and a surface protective film using the composition. Further, Patent Documents 5 and 6 disclose the technical contents of mixing a polyether modified polyoxyalkylene in an adhesive layer of a surface protective film. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2005-330464 (Patent Document 3): JP-A-2005-314476 (Patent Document 4): Japanese Special Japanese Laid-Open Patent Publication No. 2009-275128 (Patent Document 6): Japanese Patent No. 4537450

[Problems to be solved by the invention]

In the above Patent Documents 1 to 4, an antistatic agent is added to the inside of the adhesive layer, but the thickness of the adhesive layer is thicker, and the antistatic agent moves from the adhesive layer to the surface protective film over time. The amount of attached adherent moves will increase. In addition, in an optical film such as an LR (Low Reflective) polarizing plate or an AG (Anti Glare)-LR polarizing plate, since an anti-pollution treatment is applied to the surface of the optical film by using a polyoxyalkylene compound or a fluoride, When the surface protective film used for the optical film is peeled off from the optical film as the adherend, the peeling static voltage becomes high.

Further, as disclosed in Patent Documents 5 and 6, when the polyether modified polyoxyalkylene is mixed in the adhesive layer, it is difficult to finely adjust the adhesion of the surface protective film. In addition, since the polyether modified polyoxyalkylene is mixed in the adhesive layer, when the conditions for coating and drying the adhesive composition on the substrate film are changed, the adhesion formed on the surface protective film is formed. The properties of the surface of the agent layer vary subtly. Further, from the viewpoint of protecting the surface of the film for optics, the thickness of the adhesive layer cannot be made extremely thin. Therefore, according to the thickness of the adhesive layer, it is necessary to increase the amount of the polyether modified polysiloxane to be mixed in the adhesive layer, and as a result, it is easy to contaminate the surface of the adherend, the adhesion over time and the adhesion to the adherend. The pollution has changed.

In recent years, with the spread of 3D displays (stereoscopic displays), FPR (Film Patterned Retarder) films have been bonded to the surface of an optical film such as a polarizing plate. After peeling off the surface protection film bonded to the surface of the optical film, such as a polarizing plate, the FPR film is bonded. However, when the surface of the optical film such as a polarizing plate is contaminated by an adhesive or an antistatic agent used for the surface protective film, there is a problem that it is difficult to adhere the FPR film. Therefore, the surface protective film used for this use is required to have less contamination of the adherend.

On the other hand, in some liquid crystal panel manufacturers, as a method of evaluating the contamination of the adherend by the surface protective film, a method of peeling off the surface protective film bonded to the optical film such as a polarizing plate is performed. The film is re-bonded in a state in which air bubbles are mixed, and the reattached article is heat-treated under a predetermined condition, and then the surface protective film is peeled off and the surface of the adherend is observed. In this evaluation method, even if the surface contamination of the adherend is minute, if there is a difference in the surface contamination of the adherend between the portion where the bubble is mixed and the adhesive portion of the surface protective film, Bubble marks (sometimes referred to as "bubble stains") remain. Therefore, as a method of evaluating the contamination of the surface of the adherend, it is a very strict evaluation method. In recent years, even if it is judged by such a strict evaluation method, a surface protective film which has no problem in surface contamination of the adherend is required. However, the current situation is that it is difficult to solve this problem in the surface protective film using the adhesive layer containing an antistatic agent proposed in the related art.

Therefore, there is a need for a surface protective film for use in an optical film which has little contamination to the adherend and does not change over time with respect to the contamination of the adherend (does not change with time). Further, a surface protective film which suppresses the peeling static voltage when peeled off from the adherend is required to be low.

In order to solve this problem, the inventors of the present invention have conducted intensive studies. In order to reduce the contamination of the adherend and also reduce the temporal change of the antistatic property, it is necessary to reduce the amount of the antistatic agent which is presumed to be the cause of contamination of the adherend. However, when the amount of the antistatic agent added is lowered, the peeling static voltage when the surface protective film is peeled off from the adherend becomes high. The present inventors have studied a method of suppressing the peeling static voltage when the surface protective film is peeled off from the adherend without increasing the absolute amount of the antistatic agent. As a result, it was found that an antistatic agent was not added to the adhesive composition and mixed to form an adhesive layer, but the adhesive composition was applied and dried to laminate the adhesive layer, and the adhesive was applied. The present invention has been completed based on the above findings by providing an appropriate amount of an antistatic agent component on the surface of the layer and suppressing the peeling static voltage when the surface protective film is peeled off from the optical film as the adherend.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an antistatic surface protection which is less polluting to an adherend and has excellent anti-peeling electrostatic properties without deterioration over time (deterioration does not occur over time). A method of producing a film, and an antistatic surface protective film. [Method of solving the problem]

In order to solve the above problems, the technical idea of the antistatic surface protective film of the present invention is to apply an appropriate amount of 20 ° C to the surface of the adhesive layer after the adhesive composition is applied and dried to laminate the adhesive layer. The liquid silicone-based compound and the antistatic agent can suppress the contamination to the adherend, and can suppress the peeling static voltage when peeling off from the optical film as the adherend.

In order to solve the above problems, the present invention provides a method for producing an antistatic surface protective film which is formed on a single side of a resin film after forming an adhesive layer on one surface of a base film composed of a resin having transparency. a release film in which a release agent layer containing an antistatic agent is laminated, and a method for producing an antistatic surface protection film which is bonded to the surface of the adhesive layer by the release agent layer, wherein the release agent layer is contained in two A methyl polyoxyalkylene is used as a release agent as a main component, a polyoxyalkylene compound which is a liquid at 20 ° C, and a resin composition of an antistatic agent.

Further, it is preferred that the polyoxyalkylene compound is a polyether modified polyoxyalkylene.

Further, it is preferred that the antistatic agent is an alkali metal salt.

Further, it is preferable that the adhesive layer is an acrylic adhesive layer obtained by crosslinking a (meth) acrylate copolymer.

Further, in order to solve the above problems, the present invention provides an antistatic surface protective film which forms an adhesive layer on one side of a base film composed of a resin having transparency, and is a single resin film. A release film having a release agent layer containing an antistatic agent laminated thereon is formed by bonding the release agent layer to the surface of the adhesive layer, and the release agent layer contains dimethylpolysiloxane as a main component. The release agent is formed of a resin composition of a liquid polyoxyalkylene compound at 20 ° C and an antistatic agent.

Further, it is preferred that the polyoxyalkylene compound is a polyether modified polyoxyalkylene.

Further, it is preferred that the antistatic agent is an alkali metal salt.

Further, it is preferable that the adhesive layer is an acrylic adhesive layer obtained by crosslinking a (meth) acrylate copolymer.

Further, the present invention provides a film for optics to which the above-described antistatic surface protective film is bonded.

Further, the present invention provides an optical member to which the above-described antistatic surface protective film is bonded. [effect of the invention]

The antistatic surface protective film of the present invention has less contamination to the adherend, and the low contamination of the adherend does not change with time (does not change with time). Further, according to the present invention, it is possible to provide a method for producing an antistatic surface protective film and an antistatic surface protective film, wherein the surface of the adherend such as an LR polarizing plate or an AG-LR polarizing plate is made of polydecane An optical film which has been subjected to an anti-pollution treatment such as a compound or a fluoride, and the antistatic surface protective film can suppress the peeling static voltage which occurs when the antistatic surface protective film is peeled off from the adherend, and has excellent deterioration without warp. Anti-peeling electrostatic properties. According to the antistatic surface protection film of the present invention, the surface of the optical film can be reliably protected, so that the production efficiency can be improved and the yield can be improved.

Hereinafter, the present invention will be described in detail based on embodiments. Fig. 1 is a cross-sectional view showing the concept of an antistatic surface protection film of the present invention. In the antistatic surface protection film 10, the adhesive layer 2 is formed on the surface of one surface of the transparent base film 1. A release film 5 is formed on the surface of the adhesive layer 2, and the release film 5 is formed by forming a release agent layer 4 on the surface of the resin film 3.

As the base film 1 used in the antistatic surface protection film 10 of the present invention, a base film composed of a resin having transparency and flexibility is used. Thereby, the visual inspection of the optical member can be performed in a state in which the antistatic surface protective film is bonded to the optical member as the adherend. As the film made of the transparent resin used as the base film 1, polyethylene terephthalate, polyethylene naphthalate, and polyethylene isophthalate are preferably used. Polyester film such as polyethylene isophthalate) or polybutylene terephthalate. As the film, as long as it has a desired strength and is optically compatible, a film made of another resin may be used in addition to the polyester film. The base film 1 may be an unstretched film or a film obtained by uniaxial stretching or biaxial stretching. Further, the stretching ratio of the stretched film and the orientation angle in the axial direction formed by the crystallization of the stretched film may be controlled to specific values. The thickness of the base film 1 used in the antistatic surface protection film 10 of the present invention is not particularly limited, and is, for example, preferably about 12 to 100 μm ; and about 20 to 50 μm . The thickness is easier to handle and therefore better. Further, if necessary, an antifouling layer for preventing surface contamination, an antistatic layer, and a hard coat layer for preventing scratching may be provided on the surface of the base film 1 opposite to the surface on which the adhesive layer 2 is formed. Wait. Further, on the surface of the base film 1, an easy adhesion treatment such as surface modification by corona discharge or application of a primer may be performed.

Further, the adhesive layer 2 used in the antistatic surface protection film 10 of the present invention can be easily peeled off and hardly contaminated by the adhered body as long as it is bonded to the surface of the adherend. The adhesive layer is not particularly limited, but an acrylic adhesive layer obtained by crosslinking a (meth) acrylate copolymer is usually used in consideration of durability after bonding on an optical film. .

The (meth) acrylate copolymer may, for example, be a copolymer obtained by copolymerizing a main monomer with a comonomer or a functional monomer, and examples of the main monomer include n-butyl acrylate and acrylic acid. 2-ethylhexyl ester, isooctyl acrylate, isodecyl acrylate, etc.; the comonomer may, for example, be acrylonitrile, vinyl acetate, methyl methacrylate, ethyl acrylate or the like; Examples thereof include acrylic acid, methacrylic acid, hydroxyethyl acrylate, hydroxybutyl acrylate, glycidyl methacrylate, N-methylol methacrylamide, and the like. In the (meth) acrylate copolymer, both the main monomer and the comonomer may be (meth) acrylate, or one or two or more types other than (meth) acrylate may be used as the comonomer. Monomer.

Further, the (meth) acrylate copolymer may be copolymerized or mixed with a compound containing a polyoxyalkylene. Examples of the copolymerizable polyoxyalkylene-containing compound include polyethylene glycol (400) monoacrylate, polyethylene glycol (400) monomethacrylate, and methoxy polyethylene glycol (400). Acrylate, methoxypolyethylene glycol (400) methacrylate, polypropylene glycol (400) monoacrylate, polypropylene glycol (400) monomethacrylate, methoxy polypropylene glycol (400) acrylate, Methoxypolypropylene glycol (400) methacrylate or the like. By copolymerizing these polyoxyalkylene-containing monomers with the main monomers and functional monomers of the aforementioned (meth) acrylate copolymer, it is possible to obtain a copolymer composed of a polyoxyalkylene-containing copolymer. Adhesive.

The polyoxyalkylene group-containing compound which can be mixed with the (meth) acrylate copolymer is preferably a polyoxyalkylene group-containing (meth) acrylate copolymer, more preferably a polyoxyalkylene group. Examples of the polymer of the (meth)acrylic monomer of the group include polyethylene glycol (400) monoacrylate, polyethylene glycol (400) monomethacrylate, and methoxy polyethylene glycol. (400) Acrylate, methoxypolyethylene glycol (400) methacrylate, polypropylene glycol (400) monoacrylate, polypropylene glycol (400) monomethacrylate, methoxy polypropylene glycol (400) acrylic acid A polymer such as an ester or methoxypolypropylene glycol (400) methacrylate. By mixing these polyoxyalkylene-containing compounds with the above (meth) acrylate copolymer, an adhesive to which a compound containing a polyoxyalkylene group is added can be obtained.

The curing agent to be added to the adhesive layer 2 may, for example, be an isocyanate compound, an epoxy compound, a melamine compound, a metal chelate compound or the like as a crosslinking agent for crosslinking the (meth) acrylate copolymer. . Further, examples of the tackifier include rosins, coumarone-oximes, terpenes, petroleums, and phenols.

The thickness of the adhesive layer 2 used in the antistatic surface protection film 10 of the present invention is not particularly limited, and is, for example, preferably about 5 to 40 μm , more preferably about 10 to 30 μm . thickness. When the antistatic surface protection film has a peel strength (adhesive force) of 0.03 to 0.3 N/25 mm on the surface of the adherend, and the adhesive layer 2 having a microadhesive force is peeled off, the antistatic surface is peeled off from the adhered body. It is preferable because the handleability at the time of a protective film is excellent. In addition, from the viewpoint of excellent workability when the release film 5 is peeled off from the antistatic surface protection film 10, the peeling force of the release film 5 peeled off from the adhesive layer 2 is preferably 0.2 N/50 mm or less.

Further, in the release film 5 used in the antistatic surface protection film 10 of the present invention, a release agent layer 4 is formed on one surface of the resin film 3, and the release agent layer 4 is used to contain dimethyl polyfluorene. The oxidizing agent is formed as a release agent as a main component, a polyoxyalkylene compound which is a liquid at 20 ° C, and a resin composition of an antistatic agent.

Examples of the resin film 3 include a polyester film, a polyamide film, a polyethylene film, a polypropylene film, and a polyimide film. From the viewpoint of excellent transparency and low cost, polyester is particularly preferable. membrane. The resin film may be either an unstretched film or a uniaxially stretched film or a biaxially stretched film. Further, the stretching ratio of the stretched film and the orientation angle of the stretched film in the axial direction formed by crystallization may be controlled to specific values. The thickness of the resin film 3 is not particularly limited, and is, for example, preferably about 12 to 100 μm , and more preferably about 20 to 50 μm . Further, on the surface of the resin film 3, an easy adhesion treatment such as surface modification by corona discharge or application of a primer may be carried out as needed.

The release agent containing dimethyl polysiloxane as a main component constituting the release agent layer 4 may be a known polyoxane such as an addition reaction type, a condensation reaction type, a cationic polymerization type or a radical polymerization type. Alkane stripper. As a commercially available product of an addition reaction type polyoxyalkylene type release agent, for example, KS-776A, KS-847T, KS-779H, KS-837, KS-778, and KS-830 (Shin-Etsu Chemical Industry) (manufactured by the company); SRX-211, SRX-345, SRX-357, SD7333, SD7220, SD7223, LTC-300B, LTC-350G, LTC-310 (Dow Corning Toray) Co., Ltd.))). Examples of the commercially available product of the condensation reaction type include SRX-290 and SYLOFF-23 (manufactured by Dow Corning Toray Co., Ltd.). Examples of the commercially available product of the cationic polymerization type include TPR-6501, TPR-6500, UV9300, UV9315, UV9430 (manufactured by Momentive Performance Materials Inc.), and X62-7622 (Shin-Etsu Chemical Industry). (share) company manufacturing) and so on. Examples of the commercially available product of the radical polymerization type include X62-7205 (manufactured by Shin-Etsu Chemical Co., Ltd.).

Examples of the polyoxyalkylene compound which is liquid at 20 ° C constituting the release agent layer 4 include polyether modified polyoxyalkylene, alkyl modified polyoxyalkylene, and methanol higher fatty acid ester modified poly Oxane and the like. In the present invention, in order to improve the antistatic property of the surface of the adhesive layer, a polyoxyxane which is liquid at 20 ° C in a state of being dissolved in a release agent layer containing dimethyl polyoxyalkylene as a main component is used. Class of compounds. From the use of the present invention, a polyether modified polyoxyalkylene in a modified polyoxyalkylene compound is preferred. The polyether chain in the polyether modified polyoxyalkylene is composed of ethylene oxide (ethylene oxide), propylene oxide (propylene oxide) or the like, for example, by selecting the molecular weight of the polyethylene oxide used in the side chain. It is possible to adjust physical properties such as compatibility with a polyoxyalkylene stripper and an antistatic effect. Further, as a product commercially available as a polyether modified polyoxyalkylene, for example, KF-351A, KF-352A, KF-353, KF-354L, KF-355A, and KF-642 (Shin-Etsu Chemical Industry Co., Ltd.) Stocks)); SH8400, SH8700, SF8410 (manufactured by Dow Corning Toray Co., Ltd.); TSF-4440, TSF-4441, TSF-4445, TSF-4446, TSF-4450 (Mituo New Materials Co., Ltd.) Momentive Performance Materials Inc.); BYK-300, BYK-306, BYK-307, BYK-320, BYK-325, BYK-330 (manufactured by BYK-Chemie), and the like. The amount of the polyoxane compound which is a liquid at 20 ° C relative to the release agent containing dimethyl polyoxyalkylene as a main component is based on the kind of the polyoxyalkylene compound and the compatibility with the release agent. The difference may be set in consideration of the peeling static voltage required for peeling off the antistatic surface protective film from the adherend, the contamination to the adherend, the adhesion characteristics, and the like.

The antistatic agent constituting the release agent layer 4 preferably has good dispersibility for a release agent solution containing dimethyl polyoxyalkylene as a main component, and does not inhibit dimethylpolysiloxane as a main component. A hardened antistatic agent for the stripper. As such an antistatic agent, an alkali metal salt is preferred.

The alkali metal salt may, for example, be a metal salt containing lithium, sodium or potassium. Specifically, for example, it is preferred to use a cation comprising Li ⁺ , Na ⁺ , K ⁺ and Cl ^- , Br ^- , I ^- , BF ₄ ^- , PF ₆ ^- , SCN ^- , ClO ₄ ^- , CF ₃ SO ₃ ^- , (CF ₃ SO ₂ ) ₂ N ^- , (C ₂ F ₅ SO ₂ ) ₂ N ^- , (CF ₃ SO ₂ ) A metal salt composed of an anion of ₃ C ^- . Among them, it is particularly preferable to use LiBr, LiI, LiBF ₄ , LiPF ₆ , LiSCN, LiClO ₄ , LiCF ₃ SO ₃ , Li(CF ₃ SO ₂ ) ₂ N, Li(C ₂ F ₅ SO ₂ ) ₂ N, Li (CF ₃ SO ₂ ) lithium salt such as ₃ C. These alkali metal salts may be used singly or in combination of two or more. For the stabilization of the ionic substance, a compound containing a polyoxyalkylene (polyethylene glycol) structure may also be added.

The amount of the antistatic agent added to the release agent containing dimethyl polyoxyalkylene as a main component differs depending on the type of the antistatic agent and the degree of affinity with the release agent, but it is considered to be adhered. The peeling static voltage required for peeling off the antistatic surface protective film, the contamination of the adherend, the adhesion characteristics, and the like may be set.

The method of mixing the release agent containing dimethyl polysiloxane as a main component with the polyether modified polyoxyalkylene and the antistatic agent is not particularly limited. Any one of the following mixing methods may be employed: in the release agent containing dimethyl polysiloxane as a main component, a polyether modified polyoxyalkylene and an antistatic agent are added and mixed, and then the release agent is used for hardening. a method of mixing and mixing a catalyst; and preliminarily diluting a stripper having dimethylpolysiloxane as a main component with an organic solvent, adding a polyether modified polyoxyalkylene oxide and an antistatic agent, and a catalyst for removing the release agent and mixing them A method in which a stripper having polyoxyalkylene as a main component is diluted in an organic solvent, and a catalyst is added and mixed, and then a polyether-modified polysiloxane and an antistatic agent are added and mixed. Further, if necessary, a material having an antistatic effect such as a adhesion promoter such as a decane coupling agent or a compound containing a polyoxyalkylene group may be added. The mixing ratio of the release agent containing dimethyl polysiloxane as a main component to the polyether modified polyoxyalkylene and the antistatic agent is not particularly limited, but is relative to dimethylpolyoxyl The solid content 100 of the release agent containing the alkane as a main component is preferably a ratio of a polyether-modified polysiloxane and an antistatic agent in a solid content of about 5 to 100. With respect to the solid content 100 of the release agent containing dimethyl polysiloxane as a main component, if the addition amount of the polyether modified polysiloxane and the antistatic agent in terms of solid content is less than 5, antistatic The amount of the agent transferred to the surface of the adhesive layer is also small, and it is difficult to make the adhesive layer function as an antistatic. In addition, when the solid content of the polyether modified polysiloxane and the antistatic agent in terms of solid content exceeds 100, the solid content 100 of the release agent containing dimethyl polysiloxane as a main component is more than 100. The release agent which causes dimethyl polysiloxane as a main component together with the polyether modified polyoxyalkylene and the antistatic agent is also transferred to the surface of the adhesive layer, and thus the adhesive layer may be lowered. Bonding characteristics.

In the present invention, the method of forming the adhesive layer 2 on the base film 1 of the antistatic surface protection film 10 and the method of bonding the release film 5 can be carried out by a known method, and are not particularly limited. Specifically, (1) the resin composition for forming the adhesive layer 2 is applied onto one surface of the base film 1 and dried to form an adhesive layer, and then the release film 5 is bonded. (2) A method in which a resin composition for forming the adhesive layer 2 is applied onto the surface of the release film 5 and dried to form an adhesive layer, and then the base film 1 is bonded. Any of these methods can be employed.

Further, when the adhesive layer 2 is formed on the surface of the base film 1, it can be carried out by a known method. Specifically, a known coating method such as reverse coating, notched blade coating, gravure coating, slit extrusion coating, Mayer bar coating, or air knife coating can be used.

Further, similarly, when the release agent layer 4 is formed on the resin film 3, it can be carried out by a known method. Specifically, a known coating method such as gravure coating, Mylar rod coating, or air knife coating can be employed.

In the antistatic surface protection film 10 of the present invention having the above-described configuration, the surface potential when peeled off from the optical film as the adherend is preferably from +0.7 kV to -0.7 kV. Further, it is more preferable that the surface potential is +0.5 kV to -0.5 kV, and particularly preferably the surface potential is +0.1 kV to -0.1 kV. This surface potential can be adjusted by changing the kind, addition amount, and the like of the polyether modified polyoxyalkylene and the antistatic agent contained in the release agent layer.

2 is a cross-sectional view showing a state in which a release film is peeled off from the antistatic surface protection film of the present invention. By peeling off the release film 5 from the antistatic surface protection film 10 shown in FIG. 1, the polysiloxane compound at 20 ° C contained in the release agent layer 4 of the release film 5 and the antistatic property A part of the agent (reference numeral 7) is transferred (attached) to the surface of the adhesive layer 2 of the antistatic surface protective film 10. Therefore, in FIG. 2, the spot of the reference numeral 7 schematically shows a polyoxyalkylene compound which is liquid at 20 ° C and which is transferred to the surface of the adhesive layer 2 of the antistatic surface protective film and Antistatic agent. In the antistatic surface protection film of the present invention, when the antistatic surface protection film 11 in the state in which the release film is peeled off as shown in FIG. 2 is attached to the adherend, it is transferred to the adhesive layer 2 The surface of the polyoxane compound and the antistatic agent which are liquid at 20 ° C are in contact with the surface of the adherend. By this operation, it is possible to suppress the peeling static voltage when the antistatic surface protective film is peeled off again from the adherend.

Fig. 3 is a cross-sectional view showing an embodiment of an optical member of the present invention. When the release film 5 is peeled off from the antistatic surface protection film 10 of the present invention and the adhesive layer 2 is exposed, the adhesive layer 2 is bonded to the optical member 8 as an adherend. That is, the optical member 20 to which the antistatic surface protection film 10 of the present invention is bonded is shown in FIG. Examples of the optical member include an optical film such as a polarizing plate, a retardation film, a lens film, a polarizing plate which also serves as a phase difference plate, and a polarizing plate which also serves as a lens film. Such an optical member is used as a constituent member of a liquid crystal display device such as a liquid crystal display panel or an optical system device of various measuring instruments. In addition, examples of the optical member include an optical film such as an antireflection film, a hard coat film, and a transparent conductive film for a touch panel. In particular, it can be preferably used as a low-reflection treatment polarizing plate (LR polarizing plate) and an anti-glare low-reflection treatment polarizing plate (AG) which have been subjected to anti-pollution treatment on a surface which has been treated with a polyoxyalkylene compound or a fluorine compound. An antistatic surface protection film on the surface on which the anti-contamination treatment is applied to the optical film such as the -LR polarizing plate. According to the optical member of the present invention, when the antistatic surface protection film 10 is peeled off from the optical member (optical film) as the adherend, the peeling static voltage can be sufficiently suppressed to a low level, so that there is no fear of By destroying the circuit components such as the driver IC, the TFT element, and the gate line driving circuit, it is possible to improve the production efficiency in the steps of manufacturing a liquid crystal display panel and the like, and to secure the reliability of the production steps. [Examples]

The invention is further illustrated by the following examples. (Example 1) (Production of antistatic surface protective film) 5 parts by weight of an addition reaction type polyoxyalkylene (product name: SRX-345, Dow Corning Toray Co.) , Ltd.), 0.15 parts by weight of polyether modified polyoxyalkylene (product name is SH8400, manufactured by Dow Corning Toray Co., Ltd.), and 5 parts by weight of lithium perchlorate is 10% acetic acid. Ethyl ester solution, 95 parts by weight of a mixed solvent of toluene and ethyl acetate of 1:1, and 0.05 part by weight of a platinum catalyst (product name is SRX-212 Catalyst (catalyst), manufactured by Dow Corning Toray Co., Ltd.) The coatings which form the release agent layer of Example 1 were prepared by mixing together and stirring and mixing. The coating of the release agent layer of Example 1 was formed by using a Mylar rod, and the surface of the polyethylene terephthalate film having a thickness of 38 μm was applied so as to have a thickness of 0.2 μm after drying. The film was dried in a hot air circulating oven at 120 ° C for 1 minute to obtain a release film of Example 1. On the other hand, 30 parts by weight of an acrylate copolymer having a weight average molecular weight of 470,000 obtained by copolymerization of 2-ethylhexyl acrylate and 2-hydroxyethyl acrylate in a weight ratio of 100:4 was dissolved in 70. An adhesive (an ethyl acetate solution having a solid content of 30%) was obtained in parts by weight of ethyl acetate, and 1.2 parts by weight of an HDI-based hardener was added to 100 parts by weight of the adhesive (product name is Coronate HX (manufactured by Nippon Polyurethane Industry Co., Ltd.) and mixed to form an application liquid, and the application liquid was applied to the thickness so that the thickness after drying became 20 μm . The surface of the 38 μm polyethylene terephthalate film was then dried by a hot air circulating oven at 100 ° C for 2 minutes to form an adhesive layer. Then, a release agent layer (polysiloxane treatment surface) of the release film of Example 1 produced above was bonded to the surface of the adhesive layer. The obtained adhesive film was kept at 40 ° C for 5 days to harden the adhesive, and the antistatic surface protective film of Example 1 was obtained.

(Example 2) An antistatic surface protective film of Example 2 was obtained in the same manner as in Example 1 except that the thickness of the coating material forming the release agent layer of Example 1 after drying was set to 0.1 μm .

(Example 3) As the addition reaction type polyoxane of Example 1, a product of the name SRX-211 manufactured by Dow Corning Toray Co., Ltd. was used as The polyether modified polyoxyalkylene uses a product of the name KS-352A manufactured by Shin-Etsu Chemical Co., Ltd., using 10 parts by weight of lithium bis(trifluoromethanesulfonate)imide as 10% ethyl acetate. An antistatic surface protective film of Example 3 was obtained in the same manner as in Example 1 except that 5 parts by weight of lithium perchlorate was used as a 10% ethyl acetate solution.

(Comparative Example 1) 5 parts by weight of an addition reaction type polyoxyalkylene (product name: SRX-345, manufactured by Dow Corning Toray Co., Ltd.), 95 parts by weight of toluene and ethyl acetate were 1: A mixed solvent of 1 and 0.05 part by weight of a platinum catalyst (product name: SRX-212 Catalyst, manufactured by Dow Corning Toray Co., Ltd.) were mixed and stirred to prepare a release agent layer of Comparative Example 1. Paint. The coating of the release agent layer of Comparative Example 1 was formed by using a Mylar rod, and the surface of the polyethylene terephthalate film having a thickness of 38 μm was applied so as to have a thickness of 0.2 μm after drying. The film was dried in a hot air circulating oven at 120 ° C for 1 minute to obtain a release film of Comparative Example 1. On the other hand, 0.3 parts by weight of a polyether modified polyoxyalkylene (product name) was added and mixed with respect to 100 parts by weight of the adhesive of Example 1 (ethyl acetate solution having a solid content of 30%). For SH8400, manufactured by Dow Corning Toray Co., Ltd., 10 parts by weight of lithium perchlorate is a 10% ethyl acetate solution, and 1.2 parts by weight of an HDI-based hardener. (The product name is Coronate HX, manufactured by Nippon Polyurethane Industry Co., Ltd.) to form an application liquid, and the application liquid is applied to a polyethylene terpene having a thickness of 38 μm so as to have a thickness of 20 μm after drying. The surface of the formic acid glycol film was then dried by a hot air circulating oven at 100 ° C for 2 minutes to form an adhesive layer. Then, a release agent layer (polysiloxane treatment surface) of the release film of Comparative Example 1 produced above was bonded to the surface of the adhesive layer. The obtained adhesive film was kept at 40 ° C for 5 days to harden the adhesive, and the antistatic surface protective film of Comparative Example 1 was obtained.

(Comparative Example 2) An ethyl acetate having a polyether modified polyoxyalkylene (product name: SH8400, manufactured by Dow Corning Toray Co., Ltd.) was set to 0.03 part by weight, and lithium perchlorate was 10%. The antistatic surface protective film of Comparative Example 2 was obtained in the same manner as in Comparative Example 1, except that the solution was set to 1 part by weight.

(Example 4) An acrylate copolymer 30 having a weight average molecular weight of 480,000 obtained by copolymerizing 2-ethylhexyl acrylate, butyl acrylate and 2-hydroxyethyl acrylate in a weight ratio of 60:40:4 Parts by weight, dissolved in 70 parts by weight of ethyl acetate to form an adhesive (ethyl acetate solution having a solid content of 30%), and added and mixed 1.2 parts by weight of HDI with respect to 100 parts by weight of the adhesive A hardening agent (product name: Coronate HX, manufactured by Nippon Polyurethane Industry Co., Ltd.) was used to obtain an application liquid, and the application liquid was used in the same manner as in Example 1 except that the application liquid was used instead of the application liquid of Example 1. The antistatic surface protection film of Example 4 was used.

(Example 5) The weight of 2-ethylhexyl acrylate, methoxypolyethylene glycol (400) methacrylate and 2-hydroxyethyl acrylate copolymerized in a weight ratio of 90:10:4 30 parts by weight of a (meth) acrylate copolymer having a molecular weight of 380,000, dissolved in 70 parts by weight of ethyl acetate to form an adhesive (ethyl acetate solution having a solid content of 30%), relative to 100 weight A part of the adhesive was added and mixed with 1.2 parts by weight of an HDI-based hardener (product name: Coronate HX, manufactured by Nippon Polyurethane Industry Co., Ltd.) to obtain an application liquid, and the application liquid was used instead of the application liquid of Example 1. An operation of the same manner as in Example 1 was carried out, except that the antistatic surface protective film of Example 5 was obtained.

(Example 6) 30 parts by weight of an acrylate copolymer having a weight average molecular weight of 520,000 and a copolymer of 2-ethylhexyl acrylate and acrylic acid in a weight ratio of 100:4, dissolved in 70 parts by weight of ethyl acetate An adhesive (an ethyl acetate solution having a solid content of 30%) is formed in the ester, and 1.0 part by weight of an epoxy-based hardener (product name: TETRAD-C, is added and mixed with respect to 100 parts by weight of the binder). The application liquid was obtained by the Mitsubishi Gas Chemical Company Inc., and the application liquid was used in place of the application liquid of Example 1, except that the application liquid was used in the same manner as in Example 1. The antistatic surface protection film of Example 6.

The methods and results of the evaluation test are shown below. <Method for Measuring Peel Force of Release Film> A sample of the antistatic surface protection film was cut in a size of 50 mm in width and 150 mm in length. In a test environment of 23 ° C × 50% RH, the release film was peeled off in a 180° direction at a peeling speed of 300 mm/min using a tensile tester, and the strength at that time was measured, and this was used as a peeling force of the release film (N). /50mm).

<Method for Measuring Adhesion of Antistatic Surface Protective Film> An anti-glare low-reflection polarizing plate (AG-LR polarizing plate) was bonded to the surface of the glass plate by a laminator. Then, the antistatic surface protective film cut into a width of 25 mm was attached to the surface of the polarizing plate, and then stored in a test environment of 23 ° C × 50% RH for 1 day. Then, the antistatic surface protective film was peeled off in a 180° direction at a peeling speed of 300 mm/min using a tensile tester, and the strength at this time was measured and used as a bonding force (N/25 mm).

<Method for Measuring Peeling Static Voltage of Antistatic Surface Protective Film> An anti-glare low-reflection treatment polarizing plate (AG-LR polarizing plate) was bonded to the surface of the glass plate by a bonding machine. Then, the antistatic surface protective film cut into a width of 25 mm was attached to the surface of the polarizing plate, and then stored in a test environment of 23 ° C × 50% RH for 1 day. Then, using a high-speed peeling tester (manufactured by TESTER Sangyo Co., Ltd.) to peel off the antistatic surface protective film at a peeling speed of 40 m per minute, a surface potentiometer (Kiens) was used. The surface potential of the surface of the polarizing plate was measured every 10 ms, and the maximum value of the absolute value of the surface potential at this time was taken as the peeling static voltage (kV).

<Method for Confirming Surface Contamination of Antistatic Surface Protective Film> An anti-glare low-reflection treatment polarizing plate (AG-LR polarizing plate) was bonded to the surface of the glass plate by a bonding machine. Then, the antistatic surface protective film cut into a width of 25 mm was attached to the surface of the polarizing plate, and then stored in a test environment of 23 ° C × 50% RH for 3 days and 30 days. Then, the antistatic surface protective film was peeled off, and the contamination of the surface of the polarizing plate was observed by visual observation. As a criterion for determining the surface contamination property, it was judged as (○) when there was no contamination transition on the polarizing plate, and it was judged as (×) when it was confirmed that there was contamination transition on the polarizing plate.

The obtained antistatic surface protective films of Examples 1 to 6 and Comparative Examples 1 and 2 were measured, and the measurement results are shown in Tables 1 and 2. Wherein "2EHA" means 2-ethylhexyl acrylate, "HEA" means 2-hydroxyethyl acrylate, "BA" means butyl acrylate, and "#400G" is methoxy ethoxy polyethylene glycol (400) Methacrylate, "AA" means acrylic acid, "LiClO ₄ " means lithium perchlorate, and "Li(CF ₃ SO ₂ ) ₂ N" means lithium bis(trifluoromethanesulfonate) imide. The composition of the adhesive layer and the release agent layer is represented by parts by weight such that the total amount of the adhesive or the total amount of the coating forming the release agent layer is about 100 parts by weight.

From the measurement results shown in Tables 1 and 2, the following can be seen. The antistatic surface protective films of Examples 1 to 6 of the present invention have an appropriate adhesive force and have no contamination on the surface of the adherend, and the peeling static voltage when the antistatic surface protective film is peeled off from the adherend is low. On the other hand, in the antistatic surface protective film of Comparative Example 1 in which a polyoxyalkylene compound and an antistatic agent were added to the adhesive layer, peeling off when the antistatic surface protective film was peeled off from the adherend The static voltage is low and good, but it is more contaminated by the adherend after peeling. Further, in Comparative Example 2 in which the amount of the antistatic agent and the polyoxyalkylene compound was reduced, the peeling static voltage when the antistatic surface protective film was peeled off from the adherend was improved although the contamination to the adherend was improved. high. In other words, in Comparative Examples 1 and 2 in which the polyoxyalkylene compound and the antistatic agent were mixed in the adhesive, it was difficult to simultaneously satisfy the decrease in the peeling static voltage and the improvement in the staining property to the adherend. On the other hand, in the case of adding the polyoxyalkylene compound and the antistatic agent to the release agent layer, the examples 1 to 6 in which the polyoxyalkylene compound and the antistatic agent were transferred to the surface of the adhesive layer were able to The small addition amount reduces the effect of peeling off the static voltage, and therefore does not contaminate the adherend, and a good antistatic surface protective film is obtained. [Industry Utilization]

The antistatic surface protection film of the present invention can be applied to, for example, an optical film such as a polarizing plate, a phase difference plate, or a lens film for a display, and can be protected in the production steps of various optical members and the like. It is used for the surface of a member or the like. In particular, when it is used as an antistatic surface protective film of an optical film such as an LR polarizing plate or an AG-LR polarizing plate which has been subjected to antifouling treatment with a polysiloxane compound or a fluorine compound, the surface can be reduced. The amount of static electricity generated when peeling off from the adherend. The antistatic surface protective film of the present invention has less contamination to the adherend and does not deteriorate with time (does not deteriorate with time), and has excellent anti-peeling electrostatic properties, thereby improving the yield of the production step in the industrial The use value is high.

1‧‧‧Base film
2‧‧‧Adhesive layer
3‧‧‧ resin film
4‧‧‧ Stripper layer
5‧‧‧Release film
Liquid polyoxyalkylene compounds and antistatic agents at 7‧‧20 °C
8‧‧‧Adhered body (optical member)
10‧‧‧Antistatic surface protection film
11‧‧‧Anti-static surface protection film with peeling film peeled off
20‧‧‧Optical components with antistatic surface protection film

Fig. 1 is a cross-sectional view showing the concept of an antistatic surface protection film of the present invention. 2 is a cross-sectional view showing a state in which a release film is peeled off from the antistatic surface protection film of the present invention. Fig. 3 is a cross-sectional view showing an embodiment of an optical member of the present invention.

1‧‧‧Base film

2‧‧‧Adhesive layer

3‧‧‧ resin film

4‧‧‧ Stripper layer

5‧‧‧Release film

Liquid polyoxyalkylene compounds and antistatic agents at 7‧‧20 °C

10‧‧‧Antistatic surface protection film

Claims (8)

In a method for producing an antistatic surface protective film, after forming an adhesive layer on one surface of a base film made of a transparent resin, a release agent layer containing an antistatic agent is laminated on one surface of the resin film. The release film is adhered to the surface of the adhesive layer via a release agent layer, wherein the adhesive layer is an acrylic adhesive layer obtained by crosslinking a (meth) acrylate copolymer The release agent layer is formed by a resin composition containing a release agent containing dimethyl polyoxyalkylene as a main component, a polyoxyalkylene compound which is liquid at 20 ° C, and an antistatic agent. The layer of the polyoxyalkylene compound and the antistatic agent are transferred to the surface of the adhesive layer. The method for producing an antistatic surface protective film according to claim 1, wherein the polyoxyalkylene compound is a polyether modified polyoxyalkylene. The method for producing an antistatic surface protective film according to claim 1 or 2, wherein the antistatic agent is an alkali metal salt. An antistatic surface protection film is a release film in which a binder layer is formed on one surface of a base film made of a resin having transparency, and a release agent layer containing an antistatic agent is laminated on one surface of the resin film. Interposing the release agent layer on the surface of the adhesive layer, Wherein, the adhesive layer is an acrylic adhesive layer obtained by crosslinking a (meth) acrylate copolymer, and the release agent layer is provided by exfoliation containing dimethyl polyoxyalkylene as a main component a resin composition of a liquid polyoxyalkylene compound and an antistatic agent at 20 ° C, the polyoxyalkylene compound of the release agent layer and the antistatic agent transferred to the adhesive layer surface. The antistatic surface protection film of claim 4, wherein the polyoxyalkylene compound is a polyether modified polyoxyalkylene. The antistatic surface protection film of claim 4 or 5, wherein the antistatic agent is an alkali metal salt. An optical film which is adhered to an antistatic surface protection film as disclosed in claim 4 or 5. An optical member which is bonded to an antistatic surface protection film according to claim 4 or 5.