TW202317379A - Antistatic surface-protective film - Google Patents

Abstract

The present invention provides an antistatic surface- protective film, which causes less contamination to the adherend. Also, the surface-protective film has excellent antistatic performance upon peeling which does not degrade over time, and the release film is easily peeled off when used. The antistatic surface protective film is formed by: forming an adhesive layer (2) on one side of a substrate film (1) made of a transparent resin, and applying a release film (5) on the surface of the adhesive layer (2), wherein the release film (5) is formed by having a release agent layer (4) on one side of a substrate (3), and the release agent layer (4) is formed of a resin composition containing a release agent with dimethyl polysiloxane as the main component and an antistatic agent.

Description

Antistatic surface protection film

The present invention relates to an antistatic surface protection film bonded to the surface of optical components (hereinafter sometimes referred to as optical film) such as polarizers, retardation plates, and lens films for displays. More specifically, there is provided an antistatic surface protection film which is less polluting to an adherend, has excellent peeling antistatic performance which does not deteriorate with time, and which is easy to peel off a release sheet during use.

Production and transportation of optical films such as polarizers, retardation plates, lens films for displays, anti-reflection films, hard coat films, transparent conductive films for touch panels, and optical products such as displays using these films In this case, a surface protection film is pasted on the surface of the optical film to prevent dirt and scratches on the surface in subsequent steps. Regarding the appearance inspection of the optical film as an optical product, in order to save the effort of peeling off the surface protection film and bonding again and improve work efficiency, it is sometimes carried out in the state where the surface protection film is directly bonded to the optical film. Conventionally, in the production process of optical products, in order to prevent the adhesion of scratches and dirt, a surface protection film provided with an adhesive layer on one side of the base film is generally used. The surface protection film is bonded to the optical film via a slightly adhesive adhesive layer. The reason why the adhesive layer is slightly adhesive is that when the used surface protection film is peeled off from the surface of the optical film, it can be easily peeled off and the adhesive does not remain attached (that is, to prevent the generation of adhesive residue) On the optical film of the product as the adherend.

In recent years, in the production process of liquid crystal display panels, although the number of pieces produced is small, the following phenomenon has occurred: due to the peeling static voltage generated when the surface protective film bonded to the optical film is peeled off, A phenomenon in which circuit components such as driver ICs used to control the display screen of a liquid crystal display panel are destroyed, or the alignment of liquid crystal molecules is damaged. In addition, in order to reduce the power consumption of the liquid crystal display panel, the driving voltage of the liquid crystal material has been lowered, and the breakdown voltage of the driver IC has also been lowered accordingly. Recently, it is required to make the peeling electrostatic voltage within the range of +0.7kV~-0.7kV. Therefore, someone has proposed a method for preventing the disadvantages caused by the high peeling static voltage and lowering the peeling static voltage when the surface protective film is peeled from the optical film as the adherend. Surface protection film with adhesive layer containing antistatic agent.

For example, Patent Document 1 discloses a surface protection film using an adhesive consisting of an alkyltrimethylammonium salt, a hydroxyl-containing acrylic polymer, and polyisocyanate. In addition, 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 adhesive sheets using the adhesive composition. In addition, Patent Document 3 discloses an adhesive composition composed of an acrylic polymer, a polyether polyol compound, and an alkali metal salt treated with an anion-adsorbing compound, and a surface protection film using the adhesive composition. . In addition, Patent Document 4 discloses an adhesive composition composed of an ionic liquid, an alkali metal salt, and a polymer having a glass transition temperature of 0° C. or lower, and a surface protection film using the adhesive composition. In addition, Patent Document 5 discloses an adhesive composition composed of an acrylic copolymer, an alkylene oxide chain-containing acrylic copolymer, and an alkali metal salt, and a surface protection film using the adhesive composition. [Prior art literature] [Patent Document]

[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

[Technical problem to be solved by the present invention]

In the above-mentioned Patent Documents 1 to 5, an antistatic agent is added inside the adhesive layer. However, the thicker the adhesive layer is, and the longer the passage of time, the lower the thickness of the adhesive layer relative to the surface protection film. Adhesives, the more the amount of antistatic agent transferred from the adhesive layer to the adherend. In addition, in optical films such as low-reflection (LR, Low Reflective) polarizers or anti-glare (AG, Anti Glare)-LR polarizers, since the surface of the optical film is anti-polluted by silicone compounds or fluorine compounds, etc. Therefore, when such a surface protection film used for an optical film is peeled from an optical film as an adherend, the peeling static voltage increases.

In recent years, with the spread of 3D displays (stereoscopic displays), polarizing (FPR, Film Patterned Retarder) films may be bonded to the surface of optical films such as polarizers. After peeling off the surface protection film bonded on the surface of optical films, such as a polarizing plate, an FPR film is bonded. However, if the surface of an optical film such as a polarizer is contaminated with an adhesive or an antistatic agent used in a surface protection film, there is a problem that it is difficult to stick the FPR film. Therefore, it is required that the surface protection film used for this application has less pollution to the adherend.

On the other hand, some manufacturers of liquid crystal display panels adopt a method of evaluating the contamination of adherends by surface protection films by temporarily peeling off the surface protection film attached to an optical film such as a polarizer, A method of bonding again with air bubbles mixed in, heat-treating it under specified conditions, peeling off the surface protective film, and observing the surface of the adherend. In this evaluation method, if there is a difference in the surface contamination of the adherend between the portion where air bubbles are mixed and the portion that contacts the adhesive of the surface protection film even if the surface contamination of the adherend is slight, then Surface contamination of adherends remains in the form of traces of air bubbles (sometimes referred to as bubble penetration). Therefore, this evaluation method is a very strict evaluation method as an evaluation method of contamination on the surface of an adherend. In recent years, surface protection films are required to have no problem in terms of contamination of the surface of the adherend even in the result of judgment by such a strict evaluation method. However, in the conventionally proposed surface protection film using an adhesive layer containing an antistatic agent, it is difficult to solve this problem.

Therefore, there is a need for a surface protection film for an optical film that has very little contamination to an adherend and does not change over time in the staining property of the adherend. Furthermore, there is a demand for a surface protection film capable of lowering the peeling static voltage when peeling from an adherend.

In addition, conventional surface protection films are often bonded with a release film (in this case, the base material of the release film is a resin film) in order to protect the adhesive layer (Examples in Patent Documents 1 to 5 also use a release film). However, when a release film is used to protect the adhesive layer, since the base film of the surface protection film is also a resin film, when the release film is peeled off from the surface protection film, there is a problem of "peeling" that it is difficult to establish the release film. First", so it is difficult to peel off the release film. Therefore, an adhesive tape such as a pickup tape may be attached to both the base film surface and the release film surface of the surface protection film, the pickup tape may be grasped, and the release film may be peeled from the film.

Moreover, when bonding a surface protection film to an optical member, such as an optical film which is an adherend, by roll-to-roll, the operation of peeling off a peeling film can be completed in the first time. However, in the case of attaching a cut sheet-shaped surface protection film to an adherend, it is necessary to peel the release film from the surface protection film according to the number of cut surface protection films. Operation, so easy to peel off the release film is required.

In addition, when the surface protection film is cut and attached to the adherend, the cut surface protection film is usually circulated in the state of overlapping tens to hundreds of sheets, and when using the surface protection film In the step of , the surface protection film is taken one by one from the bundle of multiple overlapping surface protection films and used. Therefore, when the base material of the release sheet used in the surface protection film is a resin film, in the state where a plurality of surface protection films are stacked, the contact base film and the base material of the release sheet are separated by both. Both are caused by resin films. For this reason, when picking up a surface protection film one by one from the surface protection film supplied in the state which piled up a plurality of sheets, there arises the trouble of picking up two or more sheets at the same time. Further, when the base material of the surface protection film is a resin film, in the cutting step of the surface protection film, due to the lack of elasticity, the cutting operation is difficult. If it is strict, there is a problem that the consumption of the cutting edge becomes faster.

The inventors of the present application conducted intensive studies to solve these problems. In order to reduce the contamination of the adherend and reduce the change over time in the antistatic performance, it is necessary to reduce the amount of the antistatic agent that is presumed to be the cause of the contamination of the adherend. However, when the added amount of the antistatic agent is reduced, the peeling static voltage when peeling the surface protection film from the adherend becomes high. The inventors of the present application examined a method of suppressing the peeling static voltage at the time of peeling the surface protective film from the adherend at a low level without increasing the absolute amount of the antistatic agent added. As a result, it was found that the adhesive layer was formed not by adding and mixing an antistatic agent to the adhesive composition, but by coating and drying the adhesive composition, and laminating the adhesive layer, by By giving an appropriate amount of antistatic agent components, the peeling static voltage when the surface protective film is peeled off from the optical film as an adherend can be lowered. In addition, in order to protect the adhesive layer of the surface protection film, it was found that the release sheet can be easily peeled off by using a release sheet containing paper, and completed the present invention.

The present invention is made in view of the above circumstances, and its object is to provide an antistatic surface protection film which has less pollution to an adherend and has excellent peeling antistatic performance that does not deteriorate with time, Easy to peel off the release sheet when using. [Technical means to solve technical problems]

In order to solve the above-mentioned technical problems, the inventive concept of the present invention is that, after coating and drying the adhesive composition and laminating the adhesive layer, the antistatic surface protection film of the present invention is applied on the surface of the adhesive layer by giving an appropriate amount of antistatic The electrostatic agent suppresses the contamination of the adherend relatively low, and at the same time suppresses the peeling static voltage at the time of peeling the surface protection film from the optical film as the adherend relatively low.

In order to solve the above-mentioned technical problems, the present invention provides an antistatic surface protective film, which forms an adhesive layer on one side of a base film made of a transparent resin, and sticks and peels it on the surface of the adhesive layer. It is formed from a sheet, and it is characterized in that the release sheet has a release agent layer on one side of the substrate, and the release agent layer is composed of a release agent containing dimethyl polysiloxane as the main component, and an antistatic agent resin composition.

In addition, the substrate is preferably a substrate containing paper.

In addition, the antistatic agent is preferably an alkali metal salt.

In addition, the adhesive layer is preferably an acrylic adhesive layer formed by crosslinking a (meth)acrylate copolymer.

Moreover, this invention provides the optical film formed by bonding the said antistatic surface protection film in the state which peeled off the said release sheet.

Moreover, this invention provides the optical component which bonded the said antistatic surface protection film in the state which peeled off the said release sheet, and was formed. [Invention effect]

The antistatic surface protective film of the present invention is easy to peel off the peeling sheet during use, has little pollution to the adherend, and the low pollution to the adherend does not change with time. In addition, according to the present invention, it is possible to provide an antistatic surface protective film which is used on the surface of an adherend such as an LR polarizing plate or an AG-LR polarizing plate for optical use treated with an anti-pollution treatment using a silicone compound, a fluorine compound, or the like. In the case of a film, after the antistatic surface protective film is temporarily pasted on the adherend, the peeling static voltage generated when peeling from the adherend can be suppressed relatively low, and it has the advantage of not deteriorating with time. Peeling antistatic properties. According to the antistatic surface protection film of the present invention, since the surface of the optical film can be protected reliably, the improvement of productivity and the improvement of yield can be aimed at.

Hereinafter, the present invention will be described in detail through embodiments. Fig. 1 is a schematic sectional view showing an antistatic surface protective film of the present invention. In this antistatic surface protection film 10 , an adhesive layer 2 is formed on one surface of a transparent base film 1 . A release sheet 5 having a release agent layer 4 formed on the surface of the base material 3 is bonded to the surface of the adhesive layer 2 .

As the base film 1 used for the antistatic surface protection film 10 of this invention, the base film which consists of resin which has transparency and flexibility is used. Thereby, the external appearance inspection of an optical component can be performed in the state which bonded the antistatic surface protection film to the optical component which is an adherend. As the film made of a transparent resin used as the base film 1, polyethylene terephthalate, polyethylene naphthalate, polyethylene isophthalate, polyethylene Polyester films such as butylene terephthalate. In addition to polyester films, films formed of other resins may also be used as long as they have required strength and optical adaptability. The base film 1 may be an unstretched film, or a uniaxially or biaxially stretched film. In addition, the stretch ratio of the stretched film or the orientation angle in the axial direction accompanying 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 for example, a thickness of about 12 to 100 μm is preferred, and a thickness of about 20 to 50 μm is easier to handle and thus more convenient. preferred. In addition, an antifouling layer for preventing surface stains, an antistatic layer, a hard coat layer for preventing scratches, etc. may be provided on the surface of the base film 1 opposite to the surface on which the adhesive layer 2 is formed, as required. In addition, an easy-adhesion treatment such as surface modification by corona discharge and coating of an anchor coat agent may be performed on the surface of the base film 1 .

In addition, the adhesive layer 2 formed in the antistatic surface protection film 10 of the present invention, as long as it is attached to the surface of the adherend, can be easily peeled off after use, and the adhesive that is not easy to pollute the adherend, It is not particularly limited, however, in consideration of durability after bonding to an optical film, etc., an acrylic adhesive obtained by crosslinking a (meth)acrylate copolymer is generally used.

Examples of (meth)acrylate copolymers include mixing main monomers such as n-butyl acrylate, 2-ethylhexyl acrylate, isooctyl acrylate, and isononyl acrylate with acrylonitrile, vinyl acetate, methyl Co-monomers such as methyl acrylate and ethyl acrylate, functional monomers such as acrylic acid, methacrylic acid, hydroxyethyl acrylate, hydroxybutyl acrylate, glycidyl methacrylate, N-methylolmethacrylamide, etc. Copolymers formed by copolymerization. (Meth)acrylate copolymer, its main monomer and comonomer can be both (meth)acrylate, as a comonomer, it can also contain one or more than two kinds of (meth)acrylate of monomers.

In addition, a polyoxyalkylene group-containing compound may be copolymerized or mixed with the (meth)acrylate copolymer. Examples of compounds containing a copolymerizable polyoxyalkylene group include polyethylene glycol (400) monoacrylate, polyethylene glycol (400) monomethacrylate, and methoxypolyethylene glycol (400). Acrylates, Methoxypolyethylene Glycol (400) Methacrylate, Polypropylene Glycol (400) Monoacrylate, Polypropylene Glycol (400) Monomethacrylate, Methoxypolypropylene Glycol (400) Acrylate, Methanol Oxygenated polypropylene glycol (400) methacrylate, etc. By copolymerizing these polyoxyalkylene-containing monomers with the main monomer or functional monomer of the (meth)acrylate copolymer, an adhesive formed from a polyoxyalkylene-containing copolymer can be obtained. agent.

As the polyoxyalkylene-containing compound that can be mixed in the (meth)acrylate copolymer, a polyoxyalkylene-containing (meth)acrylate copolymer is preferable, and a polyoxyalkylene-containing ( Polymers of meth)acrylic monomers, for example, polyethylene glycol (400) monoacrylate, polyethylene glycol (400) monomethacrylate, methoxypolyethylene glycol (400) Acrylates, Methoxypolyethylene Glycol (400) Methacrylate, Polypropylene Glycol (400) Monoacrylate, Polypropylene Glycol (400) Monomethacrylate, Methoxypolypropylene Glycol (400) Acrylate, Methanol Polymers such as oxypolypropylene glycol (400) methacrylate. By mixing these polyoxyalkylene-containing compounds with the (meth)acrylate copolymer, an adhesive to which a polyoxyalkylene-containing compound is added can be obtained.

As the curing agent added to the adhesive layer 2 , examples of the crosslinking agent for crosslinking the (meth)acrylate copolymer include isocyanate compounds, epoxy compounds, melamine compounds, and metal chelate compounds. In addition, examples of thickeners include rosin, coumarone-indene, terpenes, petroleum, 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 antistatic surface protective film has excellent operability when peeling off the adherend, it is preferable that the antistatic surface protective film has a slight adhesion to the surface of the adherend with a peel strength (adhesion) of about 0.03~0.3N/25mm. Force adhesive layer2. Moreover, since the workability at the time of peeling the peeling 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/50mm or less.

In addition, the release sheet 5 used in the antistatic surface protection film 10 of the present invention forms a release agent layer 4 on one side of the base material 3, and the release agent layer 4 uses a compound containing dimethylpolysiloxane as the main Resin composition of a release agent and an antistatic agent.

The substrate 3 is a substrate containing paper, and may be paper alone or paper laminated with other materials such as plastic. Specifically, examples of paper alone include high-grade paper, art paper, kraft paper, clay court paper, cellophane, and the like; and examples of paper laminated with other materials such as plastic include polyethylene-laminated high-grade paper, polyethylene Laminated art paper, polyethylene laminated kraft paper, etc. The thickness of the substrate 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 more preferable because it is easy to handle. In addition, surface modification by frame processing or corona discharge, application of a filler to prevent penetration of a release agent coating into paper, and the like may be performed on the surface of the substrate 3 as necessary.

By using a base material containing paper as the base material 3, the workability at the time of peeling the release sheet from the antistatic surface protection film can be improved. The antistatic surface protection film 10 of the present invention is composed of a base film 1 , an adhesive layer 2 , and a release sheet 5 . Usually, when peeling off the release sheet from the surface protection film, the surface protection film is slightly bent and deformed, and at the same time, the side surface of the surface protection film is wiped with the pad of the finger, and the edge portion of the release sheet is caught with the pad of the finger to manufacture the release sheet. "Beginning". After the "head" for peeling the release sheet from the surface protection film is formed, the "head" portion of the release sheet can be grasped for peeling. When the member of the adhesive layer protecting the surface protection film is a release film using a base film of the same material as the base film, even if the surface protection film is slightly bent and deformed, the base film and the release film are simultaneously If it is deformed, it is difficult to produce a "scratch", so it is not easy to peel off the release film. In this regard, the antistatic surface protection film 10 of the present invention uses a base material containing paper in the base material 3 of the release sheet 5, so the elasticity (elasticity modulus) of the base film 1 and the release sheet 5 are different, from the perspective of antistatic Easy-peel peel-off sheet on surface protector. Therefore, the work efficiency of peeling the release sheet from the antistatic surface protection film and sticking it to the optical component is good.

In addition, depending on the type and use of the optical member as the adherend of the antistatic surface protection film of the present invention, the antistatic surface protection film may not be attached to the optical member by roll-to-roll, but may be cut The antistatic surface protection film cut into sheets of a specified size is attached to an optical member of a specified size. In this case, the antistatic surface protection film is cut to a predetermined size in advance, and the antistatic surface protection film is taken one by one from the bundle of antistatic surface protection films in a stacked state, and after peeling off the release sheet, it is bonded to the optical member . When the member protecting the adhesive layer of the antistatic surface protection film is a release film using a resin film, in the state where a plurality of antistatic surface protection films are stacked, the contact between the base film and the base material of the release film film, since both are resin films, adhesion is caused. For this reason, when picking up an antistatic surface protection film one by one from the antistatic surface protection film supplied in the state piled up, two or more sheets will be picked up at the same time. By using a base material containing paper as the base material of the release sheet, since the paper layer of the base material of the release sheet, which has a surface of a different material from the base film, is brought into contact with the base film, it is possible to prevent two sheets from being taken at the same time. The bad condition of the above antistatic surface protection film. In addition, since the number of times of peeling the release sheet from the antistatic surface protection film is the same as the number of cut antistatic surface protection films, the antistatic surface protection film of the present invention with excellent operability by using the release sheet , an improvement in operational efficiency can be achieved.

Examples of the release agent constituting the release agent layer 4 mainly composed of dimethyl polysiloxane include known silicone-based release agents such as addition reaction type, condensation reaction type, cationic polymerization type, and radical polymerization type. . Examples of commercially available addition reaction type silicone release agents include KS-776A, KS-847T, KS-779H, KS-837, KS-778, and KS-830 (Shin-Etsu Chemical Co., Ltd. ), SRX-211, SRX-345, SRX-357, SD7333, SD7220, SD7223, LTC-300B, LTC-350G, LTC-310 (manufactured by Dow Corning Toray Co., Ltd.), etc. Examples of commercially available condensation reaction type silicone release agents include SRX-290 and SYLOFF-23 (manufactured by Dow Corning Toray Co., Ltd.). Commercially available cationic polymer silicone release agents include, for example, TPR-6501, TPR-6500, UV9300, VU9315, UV9430 (manufactured by Momentive Performance Materials Company), X62-7622 (manufactured by Shin-Etsu Chemical Co., Ltd. Co., Ltd.) etc. Commercially available radical polymerized silicone-based release agents include X62-7205 (manufactured by Shin-Etsu Chemical Co., Ltd.).

As the antistatic agent constituting the release agent layer 4, it is preferable that the dispersibility to the release agent solution mainly composed of dimethyl polysiloxane is good, and it does not hinder the release of the release agent mainly composed of dimethyl polysiloxane. agent curing antistatic agent. Alkali metal salts are very suitable for use as such antistatic agents.

As an alkali metal salt, the metal salt which consists of lithium, sodium, and potassium is mentioned. Specifically, for example, it is suitable to use a cation selected from Li ⁺ , Na ⁺ , K ⁺ and a cation selected from 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 ) ₃ C ^— metal salts composed of anions. 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 SO ₂ ) ₃ C and other lithium salts. These alkali metal salts may be used alone or in combination of two or more. In order to stabilize the ionic substance, a compound containing a polyoxyalkylene structure may be added. The amount of antistatic agent added to the release agent mainly composed of dimethylpolysiloxane varies according to the type of antistatic agent and the degree of affinity with the release agent, but it is considered to be from the adherend When peeling off the antistatic surface protective film, the expected peeling static voltage, contamination to the adherend, adhesive properties, etc. can be set.

There is no particular limitation on the mixing method of the release agent mainly composed of dimethylpolysiloxane and the antistatic agent. Either of the following methods can be used: After adding and mixing an antistatic agent to a release agent mainly composed of dimethylpolysiloxane, the method of adding and mixing a catalyst for curing the release agent; The method of adding and mixing the antistatic agent and the catalyst for the curing of the release agent after the release agent with polysiloxane as the main component; diluting the release agent with dimethylpolysiloxane as the main component in an organic solvent in advance Finally, add and mix the catalyst, then add and mix the method of antistatic agent, etc. In addition, if necessary, an adhesive-improving agent such as a silane coupling agent, or a compound having a polyoxyalkylene group may be added to assist the antistatic effect.

The mixing ratio of the release agent mainly composed of dimethylpolysiloxane and the antistatic agent is not particularly limited, but relative to 100 parts of solid content of the release agent mainly composed of dimethylpolysiloxane, The ratio of the antistatic agent is preferably about 5 to 100 parts in terms of solid content. If relative to 100 parts of the solid content of the release agent with dimethyl polysiloxane as the main component, when the addition amount of the antistatic agent is less than 5 parts in terms of solid content, the antistatic agent will be added to the surface of the adhesive layer. The amount of transfer is reduced, making it difficult to exert the antistatic function imparted to the adhesive. In addition, if the addition amount of the antistatic agent in terms of solid content exceeds 100 parts relative to 100 parts of the solid content of the release agent mainly composed of dimethyl polysiloxane, the antistatic agent and dimethylpolysiloxane The release agent whose main component is polysiloxane is transferred to the surface of the adhesive layer at the same time, so the adhesive property of the adhesive may be reduced.

The method of forming the adhesive layer 2 on the base film 1 of the antistatic surface protection film 10 of the present invention and the method of bonding the release sheet 5 may be performed by known methods and are not particularly limited. Specifically, the following method can be mentioned: (1) Coating the resin composition for forming the adhesive layer 2 on one side of the base film 1, drying it to form the adhesive layer, and attaching the peeling sheet 5 method; (2) coating the resin composition for forming the adhesive layer 2 on the surface of the peeling sheet 5, and drying it, forming the adhesive layer, and attaching the base film 1, etc., using any of them Either type is acceptable.

In addition, what is necessary is just to use a well-known method about forming the adhesive layer 2 on the surface of the base film 1. Specifically, reverse coating, comma coating, gravure coating, slot die coating, Meyer rod coating, air knife coating, etc. can be used. Known coating methods such as coating.

Moreover, what is necessary is just to use a well-known method about forming the release agent layer 4 on the base material 3 similarly. Specifically, known coating methods such as gravure coating, Meyer bar coating, and air knife coating can be used.

The antistatic surface protection film 10 of the present invention having the above-mentioned structure is preferably attached to an optical film as an adherend in the state where the release sheet 5 is peeled off, and then the surface potential when peeled from the optical film is preferably +0.7kV~-0.7kV. Furthermore, the surface potential is more preferably +0.5kV~-0.5kV, particularly preferably +0.1kV~-0.1kV.

Fig. 2 is a cross-sectional view showing a state in which the release film is peeled off from the antistatic surface protection film of the present invention. By peeling off the release sheet 5 from the antistatic surface protection film 10 shown in FIG. The surface of the adhesive layer 2 exists only on the surface of the adhesive layer. Therefore, in FIG. 2 , the dots indicated by symbols 7 indicate the components of the antistatic agent transferred to the surface of the adhesive layer 2 of the antistatic surface protection film 11 in a state where the peeling sheet has been peeled off. In the antistatic surface protection film of the present invention, when the antistatic surface protection film 11 shown in FIG. The components of the antistatic agent on the surface are in contact with the surface of the adherend. Thereby, the peeling static voltage at the time of peeling the antistatic surface protection film from an adherend again can be suppressed low.

Fig. 3 is a cross-sectional view showing an example of an optical component of the present invention. The peeling sheet 5 is peeled off from the antistatic surface protection film 10 of the present invention, and in a state where the adhesive layer 2 is exposed, it is bonded to the optical component 8 as an adherend through the adhesive layer 2 . That is, FIG. 3 shows an optical component 20 bonded with the antistatic surface protection film 11 in a state where the release sheet is peeled off from the antistatic surface protection film 10 of the present invention. Examples of the optical member include optical films such as a polarizing plate, a retardation plate, a lens film, a polarizing plate serving as a retardation plate, and a polarizing plate serving as a lens film. The above-mentioned optical member can be used as a constituent member of liquid crystal display devices such as liquid crystal display panels, and optical devices such as various measuring instruments. Moreover, as an optical member, optical films, such as an antireflection film, a hard coat film, and the transparent conductive film for touch panels, are mentioned. In particular, it can be suitably used as an antistatic surface protection film to be attached to the anti-pollution-treated surface of an optical film whose surface is anti-pollution treated with a silicone compound or a fluorine compound. The optical film is low-reflection Processing polarizer (LR polarizer) or anti-glare low reflection processing polarizer (AG-LR polarizer), etc. According to the optical component of the present invention, when the antistatic surface protection film 11 in the state where the release sheet has been peeled off is peeled and removed from the optical component (optical film) as an adherend, the peeling static voltage can be sufficiently low, so , there is no need to worry about damage to circuit components such as driver ICs, TFT elements, and gate line drive circuits, which can improve the production efficiency of the steps of manufacturing liquid crystal display panels, etc., and maintain the reliability of the production steps. [Example]

Next, the present invention will be further described in detail according to the embodiments. (Example 1) (Production of antistatic surface protection film) 10 parts by weight of addition reaction silicone (manufactured by Dow Corning Toray Co., Ltd., trade name: SRX-211), 1.0 parts by weight of lithium bisfluorosulfonamide, 90 parts by weight of toluene and ethyl acetate A mixed solvent with an ester ratio of 1:1 and 0.06 parts by weight of a platinum catalyst (manufactured by Dow Corning Toray Co., Ltd., trade name: SRX-212) were mixed, stirred, and mixed to prepare a release agent for forming Example 1 layers of paint. Meyer bar coating is applied to the side of the polyethylene layer of polyethylene-laminated high-quality paper, which is produced by laminating the polyethylene layer with a weight of 53 g per square meter so that the thickness of the polyethylene layer is 20 μm. The coating for forming the release agent layer of Example 1 was coated on a cloth to a thickness of 0.5 μm after drying, and dried in a hot air circulation oven at 130° C. for 1 minute to obtain the release sheet of Example 1. On the other hand, with respect to the copolymerization of 90 parts by weight of 2-ethylhexyl acrylate, 7 parts by weight of methoxypolyethylene glycol (400) methacrylate, and 3 parts by weight of 2-hydroxyethyl acrylate 100 parts by weight of the 40% ethyl acetate solution of the adhesive polymer of Example 1, and 2 parts by weight of isocyanate curing agent (CORONATE (registered trademark) HX manufactured by TOSOH CORPORATION) were stirred and mixed, and the preparation example 1. The adhesive composition. After coating the prepared adhesive composition of Example 1 on the surface of a polyethylene terephthalate film with a thickness of 38 μm so that the thickness after drying is 20 μm, use a hot air circulation at 100° C. Dry in an oven for 2 minutes to form an adhesive layer. Thereafter, the release sheet of Example 1 prepared above was bonded to the surface of the adhesive layer via the release agent layer (silicone-treated surface) to obtain a laminated film. The obtained laminated film was kept at 40° C. for 5 days to cure the adhesive layer to obtain the antistatic surface protection film of Example 1.

(Example 2) Except that the addition reaction type silicone in Example 1 was changed to the addition reaction type silicone manufactured by Shin-Etsu Chemical Co., Ltd. with the trade name KS-847H, and the platinum catalyst was changed to Shin-Etsu Chemical in an amount of 0.1 parts by weight. The platinum catalyst manufactured by Kogyo Co., Ltd. under the trade name of CAT PL-50T was obtained in the same manner as in Example 1, except that lithium bisfluorosulfonyl imide was changed to lithium bistrifluoromethanesulfonyl imide. 2 antistatic surface protection film.

(comparative example 1) A surface protection film having no peeling antistatic property of Comparative Example 1 was obtained in the same manner as in Example 1 except that the lithium bisfluorosulfonimide of Example 1 was not used.

(comparative example 2) 10 parts by weight of an addition reaction silicone (manufactured by Dow Corning Toray Co., Ltd., trade name: SRX-211), 90 parts by weight of a mixed solvent of toluene and ethyl acetate at a ratio of 1:1, 0.06 parts by weight A platinum catalyst (manufactured by Dow Corning Toray Co., Ltd., trade name: SRX-212) was mixed, stirred and mixed to prepare a paint for forming the release agent layer of Comparative Example 2. The polyethylene side of polyethylene-laminated high-quality paper, which is produced by laminating one side of high-quality paper with a weight of 53 g per square meter so that the thickness of polyethylene is 20 μm, is coated with a Meyer bar. The paint for forming the release agent layer of Comparative Example 2 was applied to a thickness of 0.5 μm after drying, and dried for 1 minute in a hot air circulation oven at 130° C. to obtain a release sheet of Comparative Example 2. On the other hand, with respect to 100 parts by weight of the 40% ethyl acetate solution of the adhesive polymer of Example 1, 3 parts by weight of a 10% ethyl acetate solution of lithium bisfluorosulfonamide, 2 parts by weight of The isocyanate curing agent (CORONATE (registered trademark) HX manufactured by TOSOH CORPORATION) was used to prepare the adhesive composition of Comparative Example 2 on the surface of a polyethylene terephthalate film with a thickness of 38 μm, so that after drying After coating the prepared adhesive composition of Comparative Example 2 with a thickness of 20 μm, it was dried in a hot air circulation 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 adhesive layer via the release agent layer (silicone-treated surface), thereby obtaining a laminated film. The obtained laminated film was kept warm at 40° C. for 5 days to cure the adhesive layer, and the antistatic surface protection film of Comparative Example 2 was obtained.

The method and results of the evaluation test are shown below. The surface protection film used in the evaluation test method was an antistatic surface protection film in Examples 1 to 2 and Comparative Example 2, and a surface protection film without peeling antistatic performance in Comparative Example 1. <Measuring method of release force of release sheet> A sample of the surface protection film was cut into a width of 50 mm and a length of 150 mm. Under the test environment of 23°C×50%RH, use a tensile testing machine to measure the strength of peeling the peeling sheet along the direction of 180° at a peeling speed of 300mm/min, and use it as the peeling force of the peeling sheet (N/50mm ).

＜Measuring method of adhesive force of surface protection film＞ An anti-glare low-reflection treated polarizer (AG-LR polarizer) was bonded to the surface of the glass plate with a double-sided adhesive tape using a gluing machine. Then, the surface protective film cut to a width of 25 mm and the release sheet peeled off was attached to the surface of the polarizing plate, and then stored in a test environment of 23° C.×50% RH for one day. Thereafter, the strength when 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).

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

<Measurement method of peeling static voltage of surface protection film> An anti-glare low-reflection treated polarizer (AG-LR polarizer) was bonded to the surface of the glass plate with a double-sided adhesive tape using a gluing machine. Then, the surface protective film cut to a width of 25 mm and peeled off the peeling sheet was attached to the surface of the polarizing plate, and then stored in a test environment of 23° C.×50% RH for one day. Afterwards, the surface protection film was peeled off at a peeling speed of 40 m per minute using a high-speed peel tester (manufactured by TESTER SANGYO), while using a surface potentiometer (manufactured by Keyence Co., Ltd.) to measure the surface potential of the polarizer surface every 10 ms, and The maximum value of the absolute value of the surface potential at this time was taken as the peeling electrostatic voltage (kV).

<Confirmation method of surface contamination of surface protection film> An anti-glare low-reflection treated polarizer (AG-LR polarizer) was bonded to the surface of the glass plate with a double-sided adhesive tape using a gluing machine. Then, the surface protective film cut to a width of 25 mm and peeled off the peeling sheet 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. Thereafter, the surface protective film was peeled off, and the contamination on the surface of the polarizing plate was visually observed. As a criterion for determining the surface contamination, the case where there was no transfer of contamination on the polarizer was evaluated as (◯), and the case where transfer of contamination was confirmed on the polarizer was evaluated as (×).

For the obtained antistatic surface protection film of Examples 1 to 2, the surface protection film without peeling antistatic performance of Comparative Example 1, and the antistatic surface protection film of Comparative Example 2, the measurement results are shown in Table 1. "2EHA" is 2-ethylhexyl acrylate, "HEA" is 2-hydroxyethyl acrylate, "#400G" is methoxypolyethylene glycol (400) methacrylate, "AS agent (1)" Lithium difluorosulfonyl imide, "AS agent (2)" lithium bistrifluoromethanesulfonyl imide, "SRX-211" SRX-211, "KS-847H" KS-847H, "SRX- 212" is the platinum catalyst SRX-212, and "PL-50T" is the platinum catalyst CAT PL-50T. In addition, "4.7E10" of the surface resistivity is 4.7×10 ¹⁰ , and "over range" means exceeding the measurement range of the measuring machine, that is, it means 1.0×10 ¹³ Ω/□ or more.

[Table 1] Example 1 Example 2 Comparative example 1 Comparative example 2 adhesive layer 2EHA #400G HEA 2EHA #400G HEA 2EHA #400G HEA 2EHA #400G HEA AS agent (2) Release agent layer SRX-211 AS agent (1) SRX-212 KS-847H AS agent (2) PL-50T SRX-211 SRX-212 SRX-211 SRX-212 Thickness of release agent layer (μm) 0.5 0.5 0.5 0.5 Peeling force of peeling sheet (N/50mm) 0.02 0.02 0.02 0.02 Adhesion (N/25mm) 0.07 0.06 0.08 0.04 Surface resistivity of adhesive layer (Ω/□) 4.7E10 6.9E10 over range 3.3E10 Peeling electrostatic voltage (kV) 0.1 0.2 3.2 0.2 surface contamination 3 days ○ ○ ○ x 30 days ○ ○ ○ x

From the measurement results shown in Table 1, the following conclusions can be drawn. The antistatic surface protective film of Examples 1 to 2 of the present invention has moderate adhesion and does not pollute the surface of the adherend. The peeling static voltage is low when peeling off the sticky substance. On the other hand, in the surface protection film of Comparative Example 1 without antistatic agent added to the release agent layer, the surface protection film was attached to the adherend once, and then removed from the surface protection film. The peeling static voltage increases when the adherend is peeled off. In addition, the antistatic surface protection film of Comparative Example 2 in which an antistatic agent was added to the adhesive layer, the peeling static electricity when the antistatic surface protection film was once attached to the adherend and then peeled off from the adherend Depressed and good, but increased contamination of adherend after peeling. That is, in the surface protection film without peeling antistatic performance of Comparative Example 1 and the antistatic surface protection film of Comparative Example 2, it is difficult to balance the reduction of the peeling static voltage and the contamination of the adherend. On the other hand, after adding an antistatic agent 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 exists only on the surface of the adhesive layer. In the antistatic surface protection films of 1 to 2, since it has the effect of reducing the peeling static voltage by adding a small amount of antistatic agent, a good antistatic surface protection film that does not pollute the adherend is obtained. [Industrial Utilization Possibility]

The antistatic surface protection film of the present invention can be used to protect optical components such as polarizing plates, retardation plates, lens films for displays, etc., and in production steps of various other optical components, etc. s surface. In particular, even if it is used as an antistatic surface protection film for an optical film such as an LR polarizer or an AG-LR polarizer whose surface is anti-pollution treated with a silicone compound or a fluorine compound, the After being attached to the adherend, when peeling off the adherend, it can reduce the amount of static electricity generated. The antistatic surface protective film of the present invention is easy to peel off the release sheet during use, has less pollution to the adherend, and further has excellent peeling antistatic performance that does not deteriorate with time, so the operability and yield of the production process can be improved. , It is extremely valuable in industry.

1: Substrate film 2: Adhesive layer 3: Substrate 4: Stripping agent layer 5: Stripping sheet 7: Antistatic agent 8: Adhesive (optical components) 10: Antistatic surface protection film 11: Antistatic surface protection film in the state where the release sheet is peeled off 20: Optical components bonded with antistatic surface protection film

[Fig. 1] A schematic cross-sectional view of an antistatic surface protective film of the present invention; [Fig. 2] A cross-sectional view of a state where the release film is peeled off from the antistatic surface protective film of the present invention; [ Fig. 3 ] A cross-sectional view of an example of an optical component of the present invention.

1: Substrate film

2: Adhesive layer

3: Substrate

4: Stripping agent layer

5: Stripping sheet

7: Antistatic agent

10: Antistatic surface protection film

Claims (6)

A bundle of antistatic surface protection films, which is a bundle of antistatic surface protection films that overlap a plurality of cut antistatic surface protection films, is characterized in that, The antistatic surface protection film is formed by forming an adhesive layer on one side of a base film made of a transparent resin, 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 formed from a resin composition containing a release agent mainly composed of dimethylpolysiloxane and an antistatic agent . The bundle of antistatic surface protection films according to claim 1, wherein the substrate is a substrate containing paper. The bundle of antistatic surface protection films according to claim 1 or 2, wherein the antistatic agent is an alkali metal salt. The bundle of antistatic surface protection films 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, which is a bundle of the antistatic surface protection film described in any one of Claims 1 to 4, after taking the antistatic surface protection film one by one and peeling off the peeling sheet, after peeling off the peeling sheet It is formed by bonding together in the state of a sheet. An optical component, which is a bundle of the antistatic surface protection film described in any one of Claims 1 to 4, after taking the antistatic surface protection film one by one and peeling off the release sheet, after the release sheet has been peeled off Formed by bonding in a state.

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