TW201726416A - Antistatic surface protection film - Google Patents

Abstract

The present invention provides an antistatic surface protective film which has less contamination to an adherend and has excellent peeling antistatic properties without deterioration over time, and is easily peeled off from the peeling sheet during use. The antistatic surface protection film provided by the present invention has an adhesive layer (2) formed on one surface of a base film (1) made of a resin having transparency, and is bonded to the surface of the adhesive layer (2). Formed by the sheet (5), wherein the release sheet (5) is formed by having a release agent layer (4) on one side of the substrate (3), and the release agent layer (4) is made of dimethylpolysiloxane It is formed as a peeling agent of a main component, and a resin composition of an antistatic agent.

Description

Antistatic surface protection film

The present invention relates to an antistatic surface protective film which is bonded to a surface of an optical member (hereinafter sometimes referred to as an optical film) such as a polarizing plate, a phase difference plate, or a lens film for a display. More specifically, an antistatic surface protective film is provided which has less contamination to adherends and has excellent peeling antistatic properties without deterioration over time, and is easily peeled off during use.

Optical products such as optical films such as polarizing plates, phase difference plates, lens films for displays, antireflection films, hard coat films, transparent conductive films for touch panels, and displays using these films When the surface protective film is bonded to the surface of the optical film, it is possible to prevent dirt and scratches on the surface in the subsequent step. In the appearance inspection of the optical film as an optical product, in order to save the workability of peeling off the surface protective film and re-bonding, the work efficiency is improved, and the surface protective film may be directly bonded to the optical film.

Conventionally, in the preparation step of an optical product, in order to prevent the adhesion of scratches or dirt, a surface protective film having an adhesive layer on one surface of the base film is usually used. The surface protective film is bonded to the optical film via a microadhesive adhesive layer. The reason why the adhesive layer is slightly adhesive is that when the used surface protective film is peeled off from the surface of the optical film, it can be easily peeled off and the adhesive is allowed to be applied. The residue is not attached (that is, the generation of residual glue is prevented) on the optical film of the product as the adherend.

In recent years, in the production process of the liquid crystal display panel, although the number of generated components is small, the following phenomenon occurs: the peeling static voltage generated when the surface protective film attached to the optical film is peeled off and removed is caused. A circuit component such as a driver IC for controlling a display screen of a liquid crystal display panel is damaged, or a orientation of liquid crystal molecules is impaired.

Further, in order to reduce the power consumption of the liquid crystal display panel, the driving voltage of the liquid crystal material is lowered, and accordingly, the breakdown voltage of the driving IC is also lowered. Recently, it has been required to make the peeling static voltage in the range of +0.7 kV to -0.7 kV.

Therefore, when a surface protective film is peeled off from an optical film as an adherend, it is proposed to prevent a problem caused by a high peeling static voltage and to lower the peeling static voltage. A surface protective film of an adhesive layer containing an antistatic 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 comprising an ionic liquid and an acrylic polymer having an acid value of 1.0 or less, and an adhesive sheet using the adhesive 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 protective film using the same. .

Further, Patent Document 4 discloses an ionic liquid, an alkali metal salt, An adhesive composition having a polymer having a glass transition temperature of 0 ° C or less and a surface protective film using the adhesive composition.

Further, Patent Document 5 discloses an adhesive composition comprising an acrylic copolymer, an alkylene oxide chain-containing acrylic copolymer, an alkali metal salt, and a surface protective film using the adhesive composition.

[Prior Art Literature]

[Patent Literature]

[Patent Document 1]: JP-A-2005-131957

[Patent Document 2]: JP-A-2005-330464

[Patent Document 3]: JP-A-2005-314476

[Patent Document 4]: JP-A-2006-152235

[Patent Document 5]: JP-A-2009-275128

In the above-mentioned Patent Documents 1 to 5, an antistatic agent is added to the inside of the adhesive layer. However, the thicker the thickness of the adhesive layer, and the longer the time passes, the relative to the surface protective film. Viscosity, the amount of antistatic agent transferred from the adhesive layer to the adherend. Further, in an optical film such as a low-reflection (LR, Low Reflective) polarizing plate or an anti-glare (AG, Anti Glare)-LR polarizing plate, the surface of the optical film is prevented from contamination by an anthrone compound or a fluorine compound. After the treatment, the peeling static voltage when the surface protective film used for the optical film is peeled off from the optical film as the adherend is increased.

In recent years, with the popularity of 3D displays (stereo displays), A polarizing (FPR, Film Patterned Retarder) film may be bonded to the surface of an optical film such as a polarizing plate. After the surface protective film adhered to the surface of the optical film such as a polarizing plate is peeled off, the FPR film is bonded. However, if the surface of the optical film such as a polarizing plate is contaminated with an adhesive or an antistatic agent used in the surface protective film, there is a problem that it is difficult to adhere the FPR film. Therefore, the surface protective film for this use is required to have less contamination of the adherend.

On the other hand, in some liquid crystal display panel manufacturers, as a method for evaluating the contamination of an adherend by a surface protective film, a method of temporarily peeling a surface protective film bonded to an optical film such as a polarizing plate by using a surface protective film is employed. The method of re-bonding in a state in which bubbles are mixed and heat-treating under a predetermined condition, and then peeling off the surface protective film and observing the surface of the adherend. In this evaluation method, 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 portion where the adhesive of the surface protective film is in contact, The surface contamination of the adherend remains in the form of traces of bubbles (sometimes referred to as bubble infiltration). Therefore, this evaluation method is a very strict evaluation method as an evaluation method for the contamination of the surface of the adherend. In recent years, the surface protective film is required to have no problem in terms of contamination of the surface of the adherend even in the result of determination by such a strict evaluation method. However, in the surface protective film which has been proposed in the past and which uses an adhesive layer containing an antistatic agent, it is difficult to solve this problem.

Therefore, there is a need for a surface protective film for an optical film which has very little contamination of an adherend and which does not change over time with respect to the contamination of the adherend. Further, there is a need for a surface protective film which can suppress the peeling static voltage when peeling off from an adherend.

In addition, in the conventional surface protection film, in order to protect the adhesive layer, the release film is bonded in most cases (in this case, the base material of the release film is a resin film) (Examples of Patent Documents 1 to 5) A release film is also used in the middle). However, when a release film is used to protect the adhesive layer, since the base film of the surface protective film is also a resin film, when the release film is peeled off from the surface protective film, it is difficult to establish peeling of the release film. The first one, which makes it difficult to peel off the peeling film. Therefore, there is a case where an adhesive tape such as a pickup tape is attached to both the surface of the base film of the surface protective film and the surface of the release film, and the peeling film is peeled off from the film by grasping the pickup tape.

In the case where the surface protective film is bonded to an optical member such as an optical film as an adherend by roll-to-roll, the operation of peeling off the release film can be completed in the first time.

However, in the case of using the cut sheet-like surface protective film on the adherend, it is necessary to peel off the peeling film from the surface protective film in accordance with the number of the cut surface protective film. Operation, so it is required to easily peel off the release film.

Further, in the case where the surface protective film is cut and attached to the adherend, the cut surface protective film is usually circulated in a state of being overlapped by several tens to several hundreds of sheets, and a surface protective film is used. In the step, a surface protective film is taken one by one from a bundle of a plurality of overlapping surface protective films for use.

Therefore, when the base material of the release sheet used for the surface protective film is a resin film, in the state in which a plurality of surface protective films are superposed, the base film to be contacted and the base material of the release sheet are both Both are resin films and cause adhesion. Therefore, the surface protection is taken one by one from the surface protective film supplied in a state of overlapping a plurality of sheets In the case of a film, two or more defective conditions are taken at the same time.

Further, in the case where the substrate of the surface protective film is a resin film, in the cutting step of the surface protective film, since the elasticity is lacking, the cutting operation is difficult, and the cutting condition is made more in order to cut the cut surface neatly. Strict, there is a problem that the consumption of the cutting edge becomes faster.

The inventors of the present application have conducted intensive studies in order to solve these problems.

In order to reduce the contamination of the adherend and 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 the contamination of the adherend. However, when the amount of the antistatic agent added is reduced, the peeling static voltage when the surface protective film is peeled off from the adherend becomes high. The inventors of the present application have discussed 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 added. As a result, it was found that the adhesive layer was not formed by adding and mixing an antistatic agent to the adhesive composition, but by coating and drying the adhesive composition and laminating the adhesive layer on the surface of the adhesive layer. By applying an appropriate amount of the antistatic agent component, it is possible to lower the peeling static voltage when the surface protective film is peeled off from the optical film as the adherend. Further, in order to protect the adhesive layer of the surface protective film, the release sheet can be easily peeled off by using a release sheet containing paper, and the present invention has been completed.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an antistatic surface protective film which has less contamination to an adherend and has excellent peeling antistatic properties without deterioration over time. The release sheet is easily peeled off during use.

In order to solve the above technical problems, the inventive concept of the present invention is to provide an antistatic surface protective film of the present invention by applying an appropriate amount of anti-adhesion to the surface of the adhesive layer after coating and drying the adhesive composition and laminating the adhesive layer. The electrostatic agent suppresses the contamination to the adherend at a low level, and at the same time, suppresses the peeling static voltage when the surface protective film is peeled off from the optical film as the adherend.

In order to solve the above-described technical problems, the present invention provides an antistatic surface protective film which is formed by laminating on the surface of the adhesive layer by forming an adhesive layer on one surface of a base film composed of a resin having transparency. Formed by a sheet, wherein the release sheet is formed by having a release agent layer on one side of a substrate, the release agent layer comprising a release agent containing dimethyl polysiloxane as a main component, and antistatic The resin composition of the agent is formed.

Further, the substrate is preferably a substrate containing paper.

Further, the antistatic agent is preferably an alkali metal salt.

Further, the pressure-sensitive adhesive layer is preferably an acrylic pressure-sensitive adhesive layer formed by crosslinking a (meth) acrylate copolymer.

Moreover, the present invention provides a film for optics which is formed by laminating the above-mentioned antistatic surface protective film in a state in which the release sheet has been peeled off.

Further, the present invention provides an optical member which is formed by laminating the above-described antistatic surface protective film in a state where the release sheet has been peeled off.

The antistatic surface protective film of the present invention easily peels off the release sheet during use, has less contamination to the adherend, and does not change the low contamination of the adherend. this Further, according to the present invention, it is possible to provide an antistatic surface protective film which is optically used for antifouling treatment using an anthrone compound or a fluorine compound even on the surface of an adherend such as an LR polarizing plate or an AG-LR polarizing plate. In the case of the film, after the antistatic surface protective film is temporarily bonded to the adherend, the peeling static voltage generated when peeling off from the adherend can be suppressed to a low level, and it is excellent in deterioration without time. Stripping antistatic properties.

According to the antistatic surface protective film of the present invention, since the surface of the film for optics can be surely protected, improvement in productivity and improvement in yield can be achieved.

1‧‧‧Base film

2‧‧‧Adhesive layer

3‧‧‧Substrate

4‧‧‧ Stripper layer

5‧‧‧ peeling film

7‧‧‧Antistatic agent

8‧‧‧Adhesive (optical parts)

10‧‧‧Antistatic surface protection film

11‧‧‧Antistatic surface protection film stripped off the peeling sheet

20‧‧‧Optical components with antistatic surface protection film

1 is a schematic cross-sectional view showing an antistatic surface protective film of the present invention; [Fig. 2] a cross-sectional view showing a state in which a release film is peeled off from the antistatic surface protective film of the present invention; [Fig. 3] Optical member of the present invention A cross-sectional view of one embodiment.

The invention will be described in detail below by way of embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional view showing an antistatic surface protective film of the present invention. The antistatic surface protection film 10 is formed with an adhesive layer 2 on the surface of one surface of the transparent base film 1. On the surface of the adhesive layer 2, a release sheet 5 having a release agent layer 4 formed on the surface of the substrate 3 is bonded.

As the base film 1 used in the antistatic surface protection film 10 of the present invention, a base film formed of a resin having transparency and flexibility is used. Thereby, the antistatic surface protective film can be bonded to the optical portion as the adherend In the state of the piece, the visual inspection of the optical component is performed. A film composed of a resin having transparency as the base film 1 is preferably polyethylene terephthalate, polyethylene naphthalate, polyethylene isophthalate, or poly. A polyester film such as butylene terephthalate. In addition to the polyester film, a film formed of another resin may be used as long as it has a desired strength and is optically compatible. The base film 1 may be a non-stretched film or a film which is uniaxially or biaxially stretched. Further, the stretching ratio of the stretched film or the axial orientation angle formed by the crystallization of the stretched film may be controlled to a specific value.

The thickness of the base film 1 used in the antistatic surface protection film 10 of the present invention is not particularly limited, but is preferably, for example, a thickness of about 12 to 100 μm, and if it is a thickness of about 20 to 50 μm, it is easier to handle, and thus Preferably.

Further, if necessary, an antifouling layer for preventing surface fouling, an antistatic layer, a hard coat layer for preventing scratches, and the like may be provided on the surface of the base film 1 opposite to the surface on which the adhesive layer 2 is formed. Further, an easy adhesion treatment such as surface modification by corona discharge or an anchor coat agent may be performed on the surface of the base film 1.

Further, the adhesive layer 2 formed in the antistatic surface protection film 10 of the present invention can be easily peeled off after use as long as it is attached to the surface of the adherend, and is not easily contaminated with the adhesive of the adherend. In particular, an acrylic adhesive obtained by crosslinking a (meth) acrylate copolymer is usually used in consideration of durability and the like after bonding to an optical film.

Examples of the (meth) acrylate copolymer include a main monomer such as n-butyl acrylate, 2-ethylhexyl acrylate, isooctyl acrylate or isodecyl acrylate, and acrylonitrile, vinyl acetate, and A. Methyl acrylate, acrylic acid Copolymerization of comonomers such as ethyl ester, functional monomers such as acrylic acid, methacrylic acid, hydroxyethyl acrylate, hydroxybutyl acrylate, glycidyl methacrylate and N-methylol methacrylamide Things. (Meth) acrylate copolymer, the main monomer and the comonomer may both be (meth) acrylate, and as a comonomer, one or two or more (meth) acrylates may be contained. Monomer.

Further, a compound containing a polyoxyalkylene group may be copolymerized or mixed with the (meth) acrylate copolymer. Examples of the compound containing a copolymerizable polyoxyalkylene 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) acrylate, A Oxypolypropylene glycol (400) methacrylate or the like. By copolymerizing these polyoxyalkylene-containing monomers with the main monomer or functional monomer of the (meth) acrylate copolymer, adhesion formed by a polyoxyalkylene-containing copolymer can be obtained. Agent.

The polyoxyalkylene group-containing compound which can be mixed in the (meth) acrylate copolymer is preferably a polyoxyalkylene group-containing (meth) acrylate copolymer, more preferably a polyoxyalkylene group ( Examples of the polymer of the methyl)acrylic monomer 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, A Oxypolypropylene glycol (400) methacrylate And other polymers. By mixing these polyoxyalkylene-containing compounds with the (meth) acrylate copolymer, an adhesive to which a polyoxyalkylene-containing compound 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, but is preferably about 5 to 40 μm, and more preferably about 10 to 30 μm. Since the operability is excellent when the antistatic surface protective film is peeled off from the adherend, it is preferable that the antistatic surface protective film has a peel strength (adhesion) of about 0.03 to 0.3 N/25 mm with respect to the surface of the adherend. Force adhesive layer 2. In addition, since the handleability at the time of peeling off the release sheet 5 from the surface protection film 10 is excellent, it is preferable that the peeling force at the time of peeling the peeling sheet 5 from the adhesive layer 2 is 0.2 N / 50 mm or less.

Further, in the release sheet 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 substrate 3, and the release agent layer 4 contains dimethylpolysiloxane as a main component. A resin composition of a release agent of the component and an antistatic agent.

The substrate 3 is a paper-containing substrate, and may be a paper monomer or a paper in which another material such as a plastic is laminated. Specifically, examples of the paper monomer include fine paper, art paper, kraft paper, clay court paper, cellophane, and the like; and as a paper in which other materials such as plastic are laminated, a polyethylene laminate is high. Grade paper, polyethylene laminated art paper, polyethylene laminated kraft paper, etc.

The thickness of the base material 3 is not particularly limited. For example, a thickness of about 30 to 200 μm is preferable, and a thickness of about 50 to 150 μm is preferable because it is easy to handle.

Further, surface modification by frame processing or corona discharge, application of a filler for preventing penetration of the release agent coating into the paper, and the like may be performed on the surface of the substrate 3 as needed.

By using a substrate containing paper as the substrate 3, workability in peeling off the release sheet from the antistatic surface protective film can be improved. The antistatic surface protection film 10 of the present invention comprises a base film 1, an adhesive layer 2, and a release sheet 5.

In general, in the case where the release sheet is peeled off from the surface protective film, the surface protective film is slightly bent and deformed, and the side surface of the surface protective film is wiped with the finger pad, and the edge portion of the release sheet is hung with the finger pad to produce a peeling release sheet. "Beginning." After forming the "starting" for peeling off the release sheet from the surface protective film, the "starting" portion of the release sheet can be grasped for peeling. In the case where the member of the adhesive layer for protecting the surface protective film is a release film of a base material film of the same type as the base film, even if the surface protective film is slightly deformed, the base film and the release film are simultaneously When it is deformed, it is difficult to produce a "starting", so it is difficult to peel off the peeling film.

On the other hand, in the antistatic surface protection film 10 of the present invention, since the base material containing the paper is used for the base material 3 of the release sheet 5, the elasticity (elasticity) of the base film 1 and the release sheet 5 are different from the antistatic The peeling sheet is easily peeled off on the surface protective film. Therefore, the operation of peeling off the release sheet from the antistatic surface protective film and bonding it to the optical member is excellent.

Further, depending on the type and use of the optical member of the adherend which is the antistatic surface protective film of the present invention, sometimes it is not by roll-to-roll The antistatic surface protective film is bonded to the optical member, and the sheet-shaped antistatic surface protective film cut into a predetermined size is bonded to an optical member having a predetermined size. In this case, the antistatic surface protection film is taken one by one from the bundle of the antistatic surface protection film in a state in which a plurality of sheets are overlapped, and is bonded to the optical member after peeling off the release sheet. .

In the case where the member for protecting the adhesive layer of the antistatic surface protective film is a release film using a resin film, the substrate to be contacted and the substrate of the release film are in a state in which a plurality of antistatic surface protective films are overlapped. The film is brought into close contact because both of them are resin films. Therefore, when the antistatic surface protective film is taken one by one from the antistatic surface protective film supplied in a state in which a plurality of sheets are overlapped, two or more defective conditions are simultaneously taken. By using a substrate containing paper on the base material of the release sheet, the paper layer of the base material of the release sheet having the surface of the material different from the base film is brought into contact with the base film, so that it is possible to prevent two sheets from being taken at the same time. The above-mentioned adverse conditions of the antistatic surface protective film.

In addition, since the number of times of peeling off the release sheet from the antistatic surface protective film is the same as the number of sheets of the cut antistatic surface protective film, the antistatic surface protective film of the present invention excellent in workability by using the peeling release sheet is used. , can improve the efficiency of operation.

Examples of the release agent containing dimethyl polysiloxane as a main component of the release agent layer 4 include known anthrone-based release agents such as an addition reaction type, a condensation reaction type, a cationic polymerization type, and a radical polymerization type. . For example, KS-776A, KS-847T, KS-779H, KS-837, KS-778, and KS-830 (Shin-Etsu Chemical Industry Co., Ltd.) are listed as products of the addition-type oxime-based release agent. )), SRX-211, SRX-345, SRX-357, SD7333, SD7220, SD7223, LTC-300B, LTC-350G, LTC-310 (manufactured by Dow Corning Toray Co., Ltd.), and the like. For example, SRX-290, SYLOFF-23 (manufactured by Dow Corning Toray Co., Ltd.), and the like are mentioned as a product of the condensation reaction-type anthrone-based release agent. The products of the cationically polymerized anthrone-based release agent which are commercially available include, for example, TPR-6501, TPR-6500, UV9300, VU9315, UV9430 (manufactured by Momentive Performance Materials Company), and X62-7622 (Shin-Etsu Chemical Industry ( Plant))). The product of the radically polymerized fluorenone-based release agent which is commercially available is X62-7205 (manufactured by Shin-Etsu Chemical Co., Ltd.).

As the antistatic agent constituting the release agent layer 4, it is preferable that the dispersant solution containing dimethyl polysiloxane as a main component has good dispersibility and does not inhibit peeling using dimethylpolysiloxane as a main component. A cured antistatic agent for the agent. Alkali metal salts are very suitable for use as such antistatic agents.

The alkali metal salt may, for example, be a metal salt composed of lithium, sodium or potassium. Specifically, for example, a cation selected from Li ⁺ , Na ⁺ , K ⁺ and a group selected from Cl ^- , Br ^- , I ^- , BF ₄ ^- , PF ₆ ^- , SCN ^- , ClO ₄ ^- , CF ₃ SO are suitably used. a metal salt composed of an anion of ₃ ^- , (CF ₃ SO ₂ ) ₂ N ^- , (C ₂ F ₅ SO ₂ ) ₂ N ^- , (CF ₃ SO ₂ ) ₃ C ^- . Among them, 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 ) are particularly preferably used. A lithium salt of SO ₂ ) ₃ C or the like. These alkali metal salts may be used singly or in combination of two or more. In order to stabilize the ionic substance, a compound containing a polyoxyalkylene structure may also be added.

The amount of the antistatic agent added to the release agent containing dimethyl polysiloxane as a main component, depending on the type of the antistatic agent and the affinity with the release agent The degree may vary depending on the peeling static voltage expected to be peeled off from the adherend, the contamination to the adherend, the adhesion characteristics, and the like.

The method of mixing the release agent containing dimethyl polysiloxane as a main component and the antistatic agent is not particularly limited. Any one of the following methods may be used: a method of adding and mixing an antistatic agent to a release agent containing dimethyl polysiloxane as a main component, and adding and mixing a catalyst for curing the release agent; and diluting with an organic solvent in advance a method in which an antistatic agent and a catalyst for curing a stripper are added and mixed after a stripping agent containing a polyoxyalkylene as a main component; and a stripper containing dimethyl polysiloxane as a main component is diluted in an organic solvent in advance Thereafter, a catalyst is added and mixed, and then an antistatic agent is added and mixed, and the like. Further, if necessary, a material having an antistatic effect such as a labeling improver 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 and the antistatic agent is not particularly limited, but is 100 parts by weight based on the solid content of the release agent containing dimethyl polysiloxane as a main component. The antistatic agent is preferably a ratio of about 5 to 100 parts based on the solid content. When the antistatic agent is added in an amount of less than 5 parts by weight based on 100 parts by weight of the release agent containing dimethylpolysiloxane as a main component, the antistatic agent is applied to the surface of the adhesive layer. The amount of transfer is reduced, and it is difficult to exert an antistatic function imparting an adhesive. In addition, when the amount of the antistatic agent added to the solid component is more than 100 parts per 100 parts by weight of the solid content of the release agent containing dimethyl polyoxyalkylene as a main component, the antistatic agent and the dimethyl ester are used. The release agent containing the polyoxyalkylene as a main component is simultaneously transferred onto the surface of the adhesive layer, and thus the adhesive property of the adhesive may be lowered.

Forming on the substrate film 1 of the antistatic surface protection film 10 of the present invention The method of forming the adhesive layer 2 and the method of bonding the release sheet 5 are not particularly limited as long as they are carried out by a known method. Specifically, the method of (1) coating the resin composition for forming the adhesive layer 2 on one surface of the base film 1 and drying it to form an adhesive layer, and then bonding the release sheet 5 (2) Coating a resin composition for forming the adhesive layer 2 on the surface of the release sheet 5, and drying it to form an adhesive layer, a method of bonding the base film 1, and the like, using any of them One can be.

Further, the adhesive layer 2 may be formed on the surface of the base film 1 by a known method. Specifically, reverse coating, comma coating, gravure coating, slot die coating, Meyer bar coating, air knife can be used. A known coating method such as coating.

Further, similarly, the release agent layer 4 may be formed on the substrate 3 by a known method. Specifically, a known coating method such as gravure coating, Meyer bar coating, or air knife coating can be used.

When the antistatic surface protection film 10 of the present invention having the above-described structure is bonded to the optical film as the adherend in a state in which the release sheet 5 is peeled off, the surface potential when peeling off from the optical film is preferably +0.7kV~-0.7kV. Further, the surface potential is more preferably +0.5 kV to -0.5 kV, and particularly preferably +0.1 kV to -0.1 kV.

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 the release sheet 5 from the antistatic surface protection film 10 shown in Fig. 1, the composition of the antistatic agent (symbol 7) contained in the release agent layer 4 of the release sheet 5 is removed. The surface of the adhesive layer 2 to be transferred to the antistatic surface protective film 10 exists only on the surface of the adhesive layer. Therefore, in Fig. 2, the composition of the antistatic agent on the surface of the adhesive layer 2 of the antistatic surface protective film 11 in the state where the release sheet is peeled off is indicated by the spot of the symbol 7.

In the antistatic surface protective film of the present invention, when the antistatic surface protective film 11 in the state in which the release sheet is peeled off shown in FIG. 2 is attached to the adherend, it is present only on the adhesive layer 2 The composition of the antistatic agent on the surface is in contact with the surface of the adherend. Thereby, the peeling static voltage when the antistatic surface protective film is peeled off from the adherend again can be suppressed to a low level.

Fig. 3 is a cross-sectional view showing an embodiment of an optical component of the present invention.

The release sheet 5 is peeled off from the antistatic surface protection film 10 of the present invention, and is adhered to the optical member 8 as an adherend via the adhesive layer 2 in a state where the adhesive layer 2 is exposed.

That is, FIG. 3 shows the optical member 20 to which the antistatic surface protection film 11 in a state in which the release sheet is peeled off from the antistatic surface protection film 10 of the present invention is bonded. Examples of the optical member include a polarizing plate, a phase difference plate, a lens film, a polarizing plate used as a phase difference plate, and an optical film such as a polarizing plate used as a lens film. The optical member can be used as a constituent member such as a liquid crystal display device such as a liquid crystal display panel or an optical device such as 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 suitably used as an antistatic surface protective film which is bonded to a surface of an optical film which has been subjected to an antifouling treatment, such as an anthrone compound or a fluorine compound, which is subjected to an antifouling treatment, and which is low in reflection. The polarizing plate (LR polarizing plate) or the anti-glare low-reflection-treated polarizing plate (AG-LR polarizing plate) or the like is processed.

According to the optical member of the present invention, when the antistatic surface protective film 11 in a state in which the release sheet is peeled off is peeled off from the optical member (optical film) as the adherend, the peeling static voltage can be sufficiently suppressed, so that the peeling static voltage can be sufficiently suppressed. There is no need to worry about damaging the circuit components such as the driver IC, the TFT element, and the gate line driving circuit, and the production efficiency of the steps of manufacturing the liquid crystal display panel or the like can be improved, and the reliability of the production steps can be maintained.

[Examples]

Next, the present invention will be further described in detail based on the embodiments.

(Example 1)

(Production of antistatic surface protection film)

10 parts by weight of addition reaction type anthrone (manufactured by Dow Corning Toray Co., Ltd., trade name: SRX-211), 1.0 part by weight of lithium difluorosulfonimide, 90 parts by weight of toluene and ethyl acetate The ester was a 1:1 mixed solvent, and 0.06 part by weight of a platinum catalyst (manufactured by Dow Corning Toray Co., Ltd., trade name: SRX-212) was mixed, stirred and mixed to prepare a release agent for forming Example 1. Layer of paint. On the surface of a polyethylene layer of polyethylene laminated fine paper laminated on one side of a fine paper having a weight of 53 g per square meter and having a polyethylene layer thickness of 20 μm, a Meyer bar coating was used. The coating material for forming the release agent layer of Example 1 was coated with a coating to have a thickness of 0.5 μm after drying, and dried in a hot air loop type oven at 130 ° C for 1 minute to obtain a release sheet of Example 1.

On the other hand, with respect to 90 parts by weight of 2-ethylhexyl acrylate, 7 parts by weight of methoxypolyethylene glycol (400) methacrylate, and 3 parts by weight of C 100 parts by weight of a 40% ethyl acetate solution of the adhesive polymer of Example 1 formed by copolymerization of 2-hydroxyethyl enoate, stirred and mixed with 2 parts by weight of an isocyanate curing agent (CORONATE manufactured by TOSOH CORPORATION) The adhesive composition of Example 1 was prepared under the registered trademark HX).

On the surface of the polyethylene terephthalate film having a thickness of 38 μm, the prepared adhesive composition of Example 1 was applied so as to have a thickness of 20 μm after drying, and a hot air loop of 100 ° C was used. The oven was dried for 2 minutes to form an adhesive layer. Thereafter, the release sheet of Example 1 prepared above was bonded to the surface of the pressure-sensitive adhesive layer via a release agent layer (anthracene-treated surface) to obtain a laminated film. The obtained laminated film was kept at 40 ° C for 5 days to cure the adhesive layer, and the antistatic surface protective film of Example 1 was obtained.

(Example 2)

In addition, the addition reaction type fluorenone of the first embodiment was changed to an addition reaction type fluorenone of the trade name KS-847H, manufactured by Shin-Etsu Chemical Co., Ltd., and the platinum catalyst was changed to a 0.1% by weight amount of Shin-Etsu Chemical. A platinum catalyst having a trade name of CAT PL-50T, manufactured by K.K., Ltd., was obtained in the same manner as in Example 1 except that lithium bisfluorosulfonimide was changed to lithium bistrifluoromethanesulfonimide. 2 antistatic surface protection film.

(Comparative Example 1)

A surface protective film of Comparative Example 1 having no peeling antistatic property was obtained in the same manner as in Example 1 except that the lithium difluorosulfonimide of Example 1 was not used.

(Comparative Example 2)

10 parts by weight of addition reaction type fluorenone (Dow Corning Toray) Manufactured by Co., Ltd., trade name: SRX-211), 90 parts by weight of a mixed solvent of toluene and ethyl acetate of 1:1, and 0.06 part by weight of a platinum catalyst (manufactured by Dow Corning Toray Co., Ltd., commercial product) The name: SRX-212) was mixed, stirred and mixed, and a coating material for forming the release agent layer of Comparative Example 2 was prepared. On the side of polyethylene of polyethylene laminated high-grade paper which was laminated on the side of a fine paper having a weight of 53 g per square meter and having a thickness of 20 μm, the Meyer bar coating was used. The coating material for forming the release agent layer of Comparative Example 2 was applied, and the thickness after drying was 0.5 μm, and dried in a hot air loop type oven at 130 ° C for 1 minute to obtain a release sheet of Comparative Example 2.

On the other hand, with respect to 100 parts by weight of a 40% ethyl acetate solution of the adhesive polymer of Example 1, 3 parts by weight of a 10% ethyl acetate solution of lithium difluorosulfonimide and 2 parts by weight were stirred and mixed. An isocyanate curing agent (CORONATE (registered trademark) HX manufactured by TOSOH CORPORATION), and an adhesive composition of Comparative Example 2 was prepared on the surface of a polyethylene terephthalate film having a thickness of 38 μm so as to be dried. The prepared adhesive composition of Comparative Example 2 was applied in a thickness of 20 μm, and then dried using a hot air loop oven at 100 ° C for 2 minutes to form an adhesive layer. Thereafter, the release sheet of Comparative Example 2 prepared above was bonded to the surface of the pressure-sensitive adhesive layer via a release agent layer (anthracene-treated surface) to obtain a laminated film. The obtained laminated film was kept at 40 ° C for 5 days to cure the adhesive layer, and an antistatic surface protective film of Comparative Example 2 was obtained.

The methods and results of the evaluation test are shown below. The surface protective film used in the method for evaluating the test was an antistatic surface protective film in Examples 1 to 2 and Comparative Example 2, and was a surface protective film having no peeling antistatic property in Comparative Example 1.

<Method for Measuring Peel Force of Peeling Sheet>

The sample of the surface protective film was cut into a width of 50 mm and a length of 150 mm. In a test environment of 23 ° C × 50% RH, the strength at the time of peeling the release sheet was measured in a direction of 180° at a peeling speed of 300 mm/min using a tensile tester, and this was used as a peeling force of the release sheet (N/50 mm). ).

<Method for Measuring Adhesion of Surface Protective Film>

An anti-glare low-reflection polarizing plate (AG-LR polarizing plate) was attached to the surface of the glass plate with a double-sided adhesive tape using a laminating machine. Then, on the surface of the polarizing plate, a surface protective film which was cut into a state of 25 mm in width and peeled off the release sheet was attached, and then stored in a test environment of 23 ° C × 50% RH for one day. Thereafter, the strength at the time of peeling off the surface protective film was measured in a direction of 180° at a peeling speed of 300 mm/min using a tensile tester, and this was used as an adhesive force (N/25 mm).

(Method for Measuring Surface Resistivity of Adhesive Layer)

After the release sheet was peeled off from the surface protective film sample, a high-performance high-resistivity meter (Hiresta (registered trademark)-UP manufactured by Mitsubishi Chemical Analytech Co., Ltd.) was used at a voltage of 100 V and a measurement time of 30 seconds. The surface resistivity (Ω/□) of the adhesive layer was measured.

<Method for Measuring Peeling Static Voltage of Surface Protective Film>

An anti-glare low-reflection polarizing plate (AG-LR polarizing plate) was attached to the surface of the glass plate with a double-sided adhesive tape using a laminating machine. Then, on the surface of the polarizing plate, a surface protective film which was cut into a width of 25 mm and peeled off the peeling sheet was attached, and then stored in a test environment of 23 ° C × 50% RH for one day. Thereafter, the surface protective film was peeled off at a peeling speed of 40 m per minute using a high-speed peeling tester (manufactured by TESTER SANGYO) while using a surface potentiometer (Keyence Co., Ltd.). 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 Surface Protective Film>

An anti-glare low-reflection polarizing plate (AG-LR polarizing plate) was attached to the surface of the glass plate with a double-sided adhesive tape using a laminating machine. Then, on the surface of the polarizing plate, a surface protective film which was cut into a peeling sheet in a width of 25 mm was attached and then stored in a test environment of 23 ° C × 50% RH for 3 days and 30 days. Thereafter, the surface protective film was peeled off, and the contamination of the surface of the polarizing plate was visually observed. As a criterion for determining the surface contamination property, the case where no contamination was transferred to the polarizing plate was evaluated as (○), and the case where contamination transfer was confirmed on the polarizing plate was evaluated as (×).

The measurement results of the obtained antistatic surface protective films of Examples 1 to 2, the surface protective film of Comparative Example 1 having no peeling antistatic property, and the antistatic surface protective film of Comparative Example 2 are shown in Table 1. "2EHA" is 2-ethylhexyl acrylate, "HEA" is 2-hydroxyethyl acrylate, "#400G" is methoxypolyethylene glycol (400) methacrylate, "AS agent (1)" It is lithium difluorosulfonimide, "AS agent (2)" is lithium bistrifluoromethanesulfonimide, "SRX-211" is SRX-211, "KS-847H" is KS-847H, "SRX-"212" is platinum catalyst SRX-212, "PL-50T" is platinum catalyst CAT PL-50T. Further, "4.7E10" of the surface resistivity is 4.7 × 10 ¹⁰ , and "over-range" means that the measurement range of the measuring machine is exceeded, that is, 1.0 × 10 ¹³ Ω / □ or more.

From the measurement results shown in Table 1, the following conclusions can be obtained.

The antistatic surface protection film of Embodiments 1 to 2 of the present invention has a moderate adhesive force, and has no contamination on the surface of the adherend, and temporarily attaches the antistatic surface protective film to the adherend, and then removes it from the adherend The peeling static voltage at the time of peeling off the sticky material is low.

On the other hand, in the surface protective film of Comparative Example 1 which does not have an antistatic agent added to the release agent layer, the surface protective film is temporarily attached to the adherend, and then it is removed from the surface protective film. The peeling static voltage at the time of peeling off the adherend increases.

Further, the antistatic surface protective film of Comparative Example 2 in which an antistatic agent was added to the adhesive layer was temporarily peeled off from the adherend after the antistatic surface protective film was attached to the adherend. Low and good, but after peeling off The contamination of the adherend increases.

In other words, in the surface protective film having no peeling antistatic property of Comparative Example 1 and the antistatic surface protective film of Comparative Example 2, it was difficult to achieve both the reduction of the peeling static voltage and the contamination of the adherend. On the other hand, after the antistatic agent is added to the release agent layer of the release sheet, the antistatic agent is transferred on the surface of the adhesive layer so that the antistatic agent component is present only on the surface of the adhesive layer. In the antistatic surface protective film of 1 to 2, since the effect of reducing the peeling static voltage by adding a small amount of an antistatic agent is obtained, a good antistatic surface protective film which does not contaminate the adherend is obtained.

[Industrial use possibility]

The antistatic surface protective film of the present invention can be used to protect these optical members, for example, in an optical film such as a polarizing plate, a phase difference plate, a lens film for a display, and other production steps of various optical members. s surface. In particular, when it is used as an antistatic surface protective film of an optical film such as an LR polarizer or an AG-LR polarizer which has been subjected to antifouling treatment on the surface using an anthrone compound or a fluorine compound, it is temporarily attached. When it is detached from the adherend, it can reduce the amount of static electricity generated when it is peeled off from the adherend.

The antistatic surface protective film of the present invention easily peels off the release sheet during use, has less contamination to the adherend, and further has excellent peeling antistatic property without deterioration over time, thereby improving the operability and yield of the production step. The value of utilization in the industry is enormous.

1‧‧‧Base film

2‧‧‧Adhesive layer

3‧‧‧Substrate

4‧‧‧ Stripper layer

5‧‧‧ peeling film

7‧‧‧Antistatic agent

10‧‧‧Antistatic surface protection film

Claims (6)

An antistatic surface protective film formed by forming an adhesive layer on one surface of a base film composed of a resin having transparency, and attaching a release sheet to the surface of the adhesive layer. The release sheet has a release agent layer on one side of a substrate, and the release agent layer is composed of a resin composition containing a release agent containing dimethyl polysiloxane as a main component and an antistatic agent. form. The antistatic surface protection film according to claim 1, wherein the substrate is a substrate containing paper. The antistatic surface protective film according to claim 1 or 2, wherein the antistatic agent is an alkali metal salt. The antistatic surface protective film according to claim 1 or 2, wherein the adhesive layer is an acrylic adhesive layer formed by crosslinking a (meth) acrylate copolymer. An optical film formed by laminating the antistatic surface protective film according to any one of claims 1 to 4 in a state in which the release sheet is peeled off. An optical member formed by laminating the antistatic surface protective film according to any one of claims 1 to 4 in a state in which the release sheet is peeled off.