KR20220110682A - Antistatic surface-protective film - Google Patents

Abstract

The present invention provides an antistatic surface protection film with little contamination of an adherend, without deterioration over time, and having excellent antistatic release performance, wherein a release sheet of an antistatic surface protection film is easy to peel off when using. In the antistatic surface protection film, an adhesive layer (20) is formed on one surface of a base film (1) made of resin with transparency, and a release sheet (5) is bonded to a surface of the adhesive layer (2). The release sheet (5) comprises: a release agent containing dimethylpolysiloxane as a main ingredient on one surface of a base material (30); and a release agent layer (4) formed of resin composition containing an antistatic agent.

Description

Antistatic surface protection film {ANTISTATIC SURFACE-PROTECTIVE FILM}

The present invention relates to an antistatic surface protection film bonded to the surface of an optical component (hereinafter, sometimes referred to as an optical film) such as a polarizing plate, a retardation plate, and a lens film for a display. More specifically, there is provided an antistatic surface protection film that has little contamination on an adherend, does not deteriorate over time, and has excellent peeling antistatic performance, wherein the release sheet is easily peeled off during use.

When manufacturing and conveying optical products, such as optical films, such as a polarizing plate, retardation plate, display lens film, an antireflection film, a hard coat film, and a transparent conductive film for touch panels, and a display using the same, the surface of the said optical film A surface protection film is pasted together to prevent the surface contamination and flaw in a post-process. The external appearance inspection of the optical film which is an optical product may be performed in the state which pasted the surface protection film to the film for optics in order to reduce the trouble of peeling and bonding a surface protection film again, and to improve work efficiency.

DESCRIPTION OF RELATED ART Conventionally, the surface protection film which formed the adhesive layer on one side of a base film WHEREIN: In the manufacturing process of an optical product, in order to prevent the adhesion of a flaw or contamination, it is generally used. A surface protection film is bonded to the film for optics through the adhesive layer of non-adhesive force. The non-adhesive force of the pressure-sensitive adhesive layer enables easy peeling when peeling and removing the used surface protection film from the surface of the optical film, and prevents the adhesive from remaining attached to the optical film of the product as an adherend ( That is, to prevent the generation of the adhesive residue).

In recent years, in the production process of a liquid crystal display panel, circuit components, such as a driver IC for controlling the display screen of a liquid crystal display panel by the peeling electrification voltage which arises when peeling and removing the surface protection film bonded on the optical film. Although the number of occurrences of this destruction and the phenomenon that the orientation of liquid crystal molecules are impaired is small, it is occurring.

In addition, 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 driver IC is also lowered. In recent years, it is calculated|required that the peeling electrification voltage shall be within the range of +0.7 kV to -0.7 kV.

For this reason, when peeling a surface protection film from the optical film which is a to-be-adhered body, in order to prevent the problem by the high peeling electrification voltage, the surface protection film using the adhesive layer containing the antistatic agent for suppressing the peeling electrification voltage low is being proposed

For example, Patent Document 1 discloses a surface protection film using an adhesive composed of an alkyltrimethylammonium salt, a hydroxyl group-containing acrylic polymer, and polyisocyanate.

Further, Patent Document 2 discloses a pressure-sensitive adhesive composition comprising an ionic liquid and an acrylic polymer having an acid value of 1.0 or less, and pressure-sensitive adhesive sheets using the same.

Further, Patent Document 3 discloses an adhesive composition comprising an alkali metal salt treated with an acrylic polymer, a polyether polyol compound, and an anion-adsorbing compound, and a surface protection film using the same.

In addition, Patent Document 4 discloses a pressure-sensitive adhesive composition comprising an ionic liquid, an alkali metal salt, a polymer having a glass transition temperature of 0°C or less, and a surface protection film using the same.

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

Japanese Laid-Open Patent Publication No. 2005-131957 Japanese Laid-Open Patent Publication No. 2005-330464 Japanese Laid-Open Patent Publication No. 2005-314476 Japanese Laid-Open Patent Publication No. 2006-152235 Japanese Patent Laid-Open No. 2009-275128

In Patent Documents 1 to 5, an antistatic agent is added to the inside of the pressure-sensitive adhesive layer, but as the thickness of the pressure-sensitive adhesive layer increases, and as the elapsed time elapses, the pressure-sensitive adhesive layer is applied to the adherend to which the surface protection film is pasted. The amount of the antistatic agent transferred from to the adherend increases. In addition, in optical films such as LR (Low Reflective) polarizing plates and AG (Anti Glare)-LR polarizing plates, since the surface of the optical film is antifouling treated with a silicone compound or a fluorine compound, the surface used for these optical films The peeling electrification voltage at the time of peeling a protective film from the optical film which is a to-be-adhered body becomes high.

In recent years, with the spread of 3D displays (stereoscopic display), there exists a thing which bonded FPR(Film Patterned Retarder) film on the surface of films for optics, such as a polarizing plate. After peeling the surface protection film pasted on the surface of films for optics, such as a polarizing plate, an FPR film is pasted together. However, when the surface of optical films, such as a polarizing plate, is contaminated with the adhesive and antistatic agent used for a surface protection film, there exists a problem that an FPR film is hard to adhere|attach. For this reason, it is calculated|required that there are few contaminations with respect to a to-be-adhered body as for the surface protection film used for the said use.

On the other hand, in some liquid crystal panel manufacturers, as a method for evaluating the staining property of a surface protection film to an adherend, the surface protection film pasted to an optical film such as a polarizing plate is peeled once and re-bonded in a state in which air bubbles are mixed. After heat-processing a thing under predetermined conditions, the method of peeling a surface protection film and observing the surface of a to-be-adhered body is employ|adopted. In this evaluation method, even if the surface contamination of the adherend is very small, if there is a difference in the surface contamination of the adherend between the part where bubbles are mixed and the part where the pressure-sensitive adhesive of the surface protection film is in contact, there is a trace of bubbles (it is sometimes called bubble staining) ) remains as For this reason, it becomes a very strict evaluation method as an evaluation method of the stain|pollution|contamination property with respect to the surface of a to-be-adhered body. In recent years, there has been a demand for a surface protection film that does not have a problem with the contamination property on the surface of the adherend even as a result of judgment by such a strict evaluation method. However, it was a difficult situation for the surface protection film using the adhesive layer containing the antistatic agent proposed conventionally to solve the said subject.

For this reason, as a surface protection film used for the film for optics, there is very little contamination with respect to a to-be-adhered body, and it is required that the contamination property with respect to a to-be-adhered body does not change with time. Moreover, the surface protection film which suppressed the peeling electrification voltage at the time of peeling from a to-be-adhered body low is calculated|required.

Moreover, in the conventional surface protection film, in order to protect an adhesive layer, in many cases, a peeling film (in this case, the base material of a peeling film is a resin film) is pasted together (a peeling film is used also in the Example of patent documents 1-5. ). However, when a release film is used to protect the pressure-sensitive adhesive layer, since the base film of the surface protection film is also a resin film, when peeling the release film from the surface protection film, a "notch" for peeling the release film is formed. It is difficult, and there exists a problem that peeling of a peeling film is difficult. For this reason, adhesive tapes, such as a pick-up tape, are affixed on both the base film surface and the peeling film surface of a surface protection film, and it may hold a pickup tape and peel a peeling film from a film.

In addition, when bonding a surface protection film to optical components, such as an optical film which is a to-be-adhered body, by roll-to-roll, the operation|work of peeling a peeling film is completed once first.

However, when a sheet-like surface protection film is bonded to an adherend and used, the peeling film must be peeled from the surface protection film by the number of cut surface protection films, so it is required to easily peel the peeling film. .

In addition, when a surface protection film is cut and bonded to an adherend, it is common that the cut surface protection film is distributed in an overlapping state in a quantity of several dozen to several hundred sheets. Lift the surface protection film one by one from the bundle and use it.

For this reason, when the base material of the release sheet used for a surface protection film is a resin film, in the state in which several surface protection films are superimposed, the base film in contact and the base material of the release sheet both become a resin film, so they adhere. do. For this reason, when lifting a surface protection film one by one from the surface protection film supplied in the state which overlapped several sheets, the problem of lifting two or more sheets together arises.

In addition, when the base material of the surface protection film is a resin film, in the cutting process of the surface protection film, it is difficult to cut because the cushioning property is insufficient. There was a problem that the consumption of was fast.

MEANS TO SOLVE THE PROBLEM The present inventors earnestly examined in order to solve this subject.

In order to reduce the amount of contamination on the adherend and also reduce the change in antistatic performance with time, it is necessary to reduce the amount of the antistatic agent added, which is presumed to be the cause of contamination of the adherend. However, when the addition amount of an antistatic agent is reduced, the peeling electrification voltage at the time of peeling a surface protection film from a to-be-adhered body becomes high. The present inventors have investigated the method of suppressing the peeling electrification voltage at the time of peeling a surface protection film from a to-be-adhered body low without increasing the absolute amount of the addition amount of an antistatic agent. As a result, instead of adding and mixing an antistatic agent in the pressure-sensitive adhesive composition to form a pressure-sensitive adhesive layer, the pressure-sensitive adhesive composition is coated and dried to laminate the pressure-sensitive adhesive layer, and then an appropriate amount of an antistatic agent component is applied to the surface of the pressure-sensitive adhesive layer to protect the surface. It discovered that the peeling electrification voltage at the time of peeling a film from the optical film which is a to-be-adhered body could be suppressed low. Moreover, by using the peeling sheet containing paper for protection of the adhesive layer of a surface protection film, it discovered that it became possible to peel a peeling sheet easily, and completed this invention.

The present invention has been made in view of the above circumstances, and is an antistatic surface protection film having little contamination on an adherend, not deteriorated over time, and excellent peeling antistatic performance. It makes it a subject to provide a film.

In order to solve the above problems, in the antistatic surface protection film of the present invention, after coating and drying the pressure-sensitive adhesive composition and laminating the pressure-sensitive adhesive layer, an appropriate amount of an antistatic agent is applied to the surface of the pressure-sensitive adhesive layer to reduce contamination to the adherend. It is making it a technical idea to suppress low the peeling electrification voltage at the time of peeling from the optical film which is a to-be-adhered body, suppressing low.

In order to solve the above problems, the present invention is an antistatic surface protection film comprising a pressure-sensitive adhesive layer formed on one side of a base film made of a resin having transparency, and a release sheet is bonded to the surface of the pressure-sensitive adhesive layer, An antistatic surface protection film is provided, wherein the release sheet has on one side of a base material a release agent containing dimethylpolysiloxane as a main component, and a release agent layer formed of a resin composition containing an antistatic agent.

In addition, it is preferable that the substrate is a substrate including paper.

Moreover, it is preferable that the said antistatic agent is an alkali metal salt.

Moreover, it is preferable that the said adhesive layer is an acrylic adhesive layer formed by bridge|crosslinking a (meth)acrylate copolymer.

Moreover, this invention provides the film for optics in which the said antistatic surface protection film is bonded together in the state which peeled the said peeling sheet.

Moreover, this invention provides the optical component by which the said antistatic surface protection film is bonded together in the state which peeled the said peeling sheet.

In the antistatic surface protection film of the present invention, the release sheet is easily peeled off during use, there is little contamination on the adherend, and the low contamination on the adherend does not change with time. Further, according to the present invention, even in the case of an optical film in which the surface of an adherend, such as an LR polarizing plate or an AG-LR polarizing plate, has been subjected to antifouling treatment with a silicone compound or a fluorine compound, an antistatic surface protection film is once bonded to the adherend. Then, it is possible to provide an antistatic surface protection film that can suppress a peeling electrification voltage generated when peeling from an adherend low, does not deteriorate over time, and has excellent peeling antistatic performance.

ADVANTAGE OF THE INVENTION According to the antistatic surface protection film of this invention, productivity improvement and a yield improvement can be aimed at at the point which can protect the surface of an optical film reliably.

1 is a cross-sectional view showing the concept of the antistatic surface protection film of the present invention.
It is sectional drawing which shows the state which peeled the peeling film from the antistatic surface protection film of this invention.
3 is a cross-sectional view showing one of the embodiments of the optical component of the present invention.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail based on embodiment.

1 is a cross-sectional view showing the concept of the antistatic surface protection film of the present invention. As for this antistatic surface protection film 10, the adhesive layer 2 is formed in the surface of one side of the transparent base film 1. The release sheet 5 in which the release agent layer 4 was formed on the surface of the base material 3 is pasted together on the surface of this adhesive layer 2 .

As the base film 1 used for the antistatic surface protection film 10 according to the present invention, a base film made of a resin having 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 a to-be-adhered body. As for the film which consists of resin which has transparency used as the base film 1, Preferably, polyester films, such as a polyethylene terephthalate, a polyethylene naphthalate, a polyethylene isophthalate, and a polybutylene terephthalate, are used. In addition to the polyester film, a film made of another resin can also be used as long as it has a required strength and has optical aptitude. An unstretched film may be sufficient as the base film 1, and the uniaxially or biaxially stretched film may be sufficient as it. Moreover, you may control the orientation angle of the axial direction formed by the draw ratio of a stretched film and crystallization of a stretched film to a specific value.

Although the thickness of the base film 1 used for the antistatic surface protection film 10 according to the present invention is not particularly limited, for example, a thickness of about 12 to 100 μm is preferable, and a thickness of about 20 to 50 μm. It is easy to handle, and it is more preferable.

In addition, an antifouling layer for preventing surface contamination, an antistatic layer, a scratch preventing hard coat layer, etc. can be formed on the surface opposite to the surface on which the adhesive layer 2 of the base film 1 is formed, if necessary. Moreover, you may give the surface of the base film 1 easy adhesion processing, such as surface modification by corona discharge, and application|coating of an anchor coat agent.

In addition, the pressure-sensitive adhesive layer 2 used in the antistatic surface protection film 10 according to the present invention adheres to the surface of the adherend, is easily peeled off after use, and is an adhesive that is difficult to contaminate the adherend. Although it does not specifically limit, When durability etc. after bonding to the optical film are considered, it is common to use the acrylic adhesive formed by bridge|crosslinking a (meth)acrylate copolymer.

Examples of the (meth)acrylate copolymer include main monomers such as n-butyl acrylate, 2-ethylhexyl acrylate, isooctyl acrylate and isononyl acrylate, and acrylonitrile, vinyl acetate, methyl methacrylate, and ethyl A copolymer obtained by copolymerizing a comonomer such as acrylate, a functional monomer such as acrylic acid, methacrylic acid, hydroxyethyl acrylate, hydroxybutyl acrylate, glycidyl methacrylate, or N-methylol methacrylamide can be heard As for the (meth)acrylate copolymer, all of the main monomer and the comonomer may be (meth)acrylate, and may contain 1 type(s) or 2 or more types of monomers other than (meth)acrylate as a comonomer.

Moreover, you may copolymerize or mix the compound containing a polyoxyalkylene group with a (meth)acrylate copolymer. As a compound containing a copolymerizable polyoxyalkylene group, polyethylene glycol (400) monoacrylic acid ester, polyethylene glycol (400) monomethacrylic acid ester, methoxy polyethylene glycol (400) acrylate, methoxy polyethylene glycol (400) Methacrylate, polypropylene glycol (400) monoacrylic acid ester, polypropylene glycol (400) monomethacrylic acid ester, methoxy polypropylene glycol (400) acrylate, methoxy polypropylene glycol (400) methacrylate, etc. can be heard By copolymerizing the monomer containing these polyoxyalkylene groups with the main monomer or functional monomer of the said (meth)acrylate copolymer, the adhesive which consists of a copolymer containing a polyoxyalkylene group can be obtained.

As a compound containing a polyoxyalkylene group which can be mixed with a (meth)acrylate copolymer, the (meth)acrylate copolymer containing a polyoxyalkylene group is preferable, and the (meth)acrylic type containing a polyoxyalkylene group. A polymer of a monomer is more preferable, for example, polyethylene glycol (400) monoacrylic acid ester, polyethylene glycol (400) monomethacrylic acid ester, methoxy polyethylene glycol (400) acrylate, methoxy polyethylene glycol (400) meta Polymers such as acrylate, polypropylene glycol (400) monoacrylic acid ester, polypropylene glycol (400) monomethacrylic acid ester, methoxy polypropylene glycol (400) acrylate, methoxy polypropylene glycol (400) methacrylate can be heard By mixing the compound containing these polyoxyalkylene groups with the said (meth)acrylate copolymer, the adhesive to which the compound containing a polyoxyalkylene group was added can be obtained.

As a hardening|curing agent added to the adhesive layer 2, an isocyanate compound, an epoxy compound, a melamine compound, a metal chelate compound etc. are mentioned as a crosslinking agent which bridge|crosslinks a (meth)acrylate copolymer. Moreover, as a tackifier, a rosin type, a coumaron indene type, a terpene type, petroleum type, a phenol type, etc. are mentioned.

Although the thickness of the adhesive layer 2 used for the antistatic surface protection film 10 which concerns on this invention is not specifically limited, For example, the thickness of about 5-40 micrometers is preferable, and the thickness of about 10-30 micrometers is more preferable. When peeling the antistatic surface protection film from the adherend, the adhesive layer 2 having a non-adhesive force of about 0.03 to 0.3 N/25 mm in peeling strength (adhesive force) of the antistatic surface protection film to the surface of the adherend It is preferred from the viewpoint of excellent operability. Moreover, since it is excellent in the operability at the time of peeling the peeling sheet 5 from the antistatic surface protection film 10, 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.

The release sheet 5 used for the antistatic surface protection film 10 according to the present invention is a release agent layer 4 using a resin composition containing a release agent containing dimethylpolysiloxane as a main component and an antistatic agent on one side of a base material 3 ) is formed.

The base material 3 is a base material containing paper, and may be a single piece of paper or may be any of paper on which other materials such as plastic are laminated. Specific examples of the paper alone include fine paper, art paper, kraft paper, clay coated paper, glassine paper, and the like. As paper on which other materials such as plastic are laminated, polyethylene laminate high quality paper, polyethylene laminate art paper, polyethylene laminate kraft paper and the like.

Although the thickness of the base material 3 is not specifically limited, For example, the thickness of about 30-200 micrometers is preferable, if it is thickness of about 50-150 micrometers, handling is easy, and it is more preferable.

In addition, if necessary, the surface of the base material 3 may be subjected to a frame treatment, surface modification by corona discharge, application of a filler to prevent penetration of the release agent paint into paper, or the like.

By using the base material containing paper as the base material 3, workability|operativity at the time of peeling a peeling sheet from an antistatic surface protection film improves. The antistatic surface protection film 10 according to the present invention includes a base film 1 , an adhesive layer 2 , and a release sheet 5 .

In general, when peeling the release sheet from the surface protection film, the release sheet is peeled by rubbing the side of the surface protection film with your fingertips while slightly bending and deforming the surface protection film, so that the edge portion of the release sheet is caught by the fingertips. Make a “notch”. After the "notch" for peeling a peeling sheet from a surface protection film arises, the "notch" part of a peeling sheet can be grabbed and peeled. When the member protecting the pressure-sensitive adhesive layer of the surface protection film is a release film using a base film of the same type as the base film, even if the surface protection film is slightly bent and deformed, the base film and the release film are deformed together, resulting in a “notch ', it is not easy to peel the release film.

On the other hand, since the antistatic surface protection film 10 according to the present invention uses a substrate including paper for the substrate 3 of the release sheet 5, the elasticity of the substrate film 1 and the release sheet 5 is used. (modulus of elasticity) is different and it becomes easy to peel a peeling sheet from an antistatic surface protection film. For this reason, the efficiency of the operation|work which peels a peeling sheet from an antistatic surface protection film and bonds it to an optical component improves.

In addition, depending on the type of the optical member which is an adherend of the antistatic surface protection film which concerns on this invention, or a use, the antistatic surface protection film is not pasted up to the optical member in roll-to-roll, but a sheet shape of a predetermined size. In some cases, the antistatic surface protection film cut by the slab is bonded to the optical member of a predetermined size. In this case, after cutting to a predetermined size beforehand, lifting an antistatic surface protection film one by one from the bundle|flux of the antistatic surface protection film of the state which overlapped several sheets, and peeling a peeling sheet, it bonds to an optical member.

When the member for protecting the pressure-sensitive adhesive layer of the antistatic surface protection film is a release film using a resin film, in a state in which a plurality of antistatic surface protection films are superposed, both the base film and the base film of the release film are resin Since it becomes a film, it adheres closely. For this reason, when lifting an antistatic surface protection film one by one from the antistatic surface protection film supplied in the state which overlapped several sheets, the problem of lifting two or more sheets together arises. 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 having a surface of a material different from that of the base film is in contact with the base film, two or more antistatic surface protection films are lifted together. problems can be avoided.

In addition, since the number of times the release sheet is peeled from the antistatic surface protection film is equal to the number of sheets of the antistatic surface protection film cut, the antistatic surface protection film according to the present invention excellent in workability for peeling the release sheet is used By doing so, the improvement of work efficiency can be aimed at.

As a release agent which has dimethylpolysiloxane as a main component which comprises the release agent layer 4, well-known silicone type release agents, such as an addition reaction type, a condensation reaction type, a cationic polymerization type, and a radical polymerization type, are mentioned. Products marketed as addition-reactive silicone-based release agents include, for example, KS-776A, KS-847T, KS-779H, KS-837, KS-778, KS-830 (manufactured by Shin-Etsu Chemical Co., Ltd.), SRX- 211, SRX-345, SRX-357, SD7333, SD7220, SD7223, LTC-300B, LTC-350G, LTC-310 (manufactured by Toray Dow Corning Co., Ltd.) and the like. As a product marketed as a condensation reaction type, SRX-290, SYLOFF-23 (made by Toray Dow Corning Co., Ltd.) etc. are mentioned, for example. Products marketed as cationic polymerization types include, for example, TPR-6501, TPR-6500, UV9300, UV9315, UV9430 (manufactured by Momentive Performance Materials), X62-7622 (manufactured by Shin-Etsu Chemical Co., Ltd.), etc. can be heard As a product marketed as a radical polymerization type, X62-7205 (made by Shin-Etsu Chemical Industry Co., Ltd.) etc. is mentioned, for example.

The antistatic agent constituting the release agent layer 4 preferably has good dispersibility in a release agent solution containing dimethylpolysiloxane as a main component and does not inhibit curing of the release agent containing dimethylpolysiloxane as a main component. As such an antistatic agent, an alkali metal salt is preferable.

As an alkali metal salt, the metal salt which consists of lithium, sodium, and potassium is mentioned. Specifically, for example, a cation consisting of Li ⁺ , Na ⁺ , K ⁺ , Cl ^- , Br ^- , I ^- , BF ₄ ^- , PF ₆ ^- , SCN ^- , ClO ₄ ^- , CF ₃ SO ₃ ^- , A metal salt composed of an anion composed of (CF ₃ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₃ C ⁻ is preferably used. 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 ) A lithium salt such as SO ₂ ) ₃ C is preferably used. These alkali metal salts may be used independently and may mix and use 2 or more types. For stabilization of the ionic substance, a compound containing a polyoxyalkylene structure may be added.

The amount of the antistatic agent added to the release agent containing dimethylpolysiloxane as a main component varies depending on the type of antistatic agent and the degree of affinity with the release agent, but the desired peeling electrification voltage when peeling the antistatic surface protection film from the adherend, the adherend It can be set in consideration of the contamination properties and adhesive properties.

The mixing method of the release agent and antistatic agent which have dimethylpolysiloxane as a main component is not specifically limited. A method of adding and mixing an antistatic agent to a release agent containing dimethylpolysiloxane as a main component and mixing, followed by adding and mixing a catalyst for curing the release agent, after diluting a release agent containing dimethylpolysiloxane as a main component with an organic solvent in advance Any method, such as a method of adding and mixing siloxane as a main component, diluting the release agent containing siloxane as a main component in advance with an organic solvent, adding and mixing a catalyst, and then adding and mixing an antistatic agent, may be used. Moreover, you may add materials which assist the antistatic effect, such as a close_contact|adherence improving agent, such as a silane coupling agent, and a compound containing a polyoxyalkylene group, as needed.

Although the mixing ratio of the release agent containing dimethylpolysiloxane as a main component and the antistatic agent is not particularly limited, the ratio of the antistatic agent as a solid content of about 5 to 100 is preferable with respect to the solid content of 100 of the release agent containing dimethylpolysiloxane as a main component. If the added amount of the antistatic agent in terms of the solid content is less than a ratio of 5 to 100 solid content of the release agent containing dimethylpolysiloxane as a main component, the amount of the antistatic agent transferred to the surface of the pressure-sensitive adhesive layer is also reduced, and the antistatic function is difficult to be exhibited on the pressure-sensitive adhesive . In addition, when the addition amount of the antistatic agent in terms of the solid content exceeds a ratio of 100 with respect to the solid content 100 of the release agent containing dimethylpolysiloxane as the main component, the release agent containing dimethylpolysiloxane as the main component together with the antistatic agent is also transferred to the surface of the pressure-sensitive adhesive layer. There is a possibility that the adhesive properties of the

The method of forming the pressure-sensitive adhesive layer 2 on the base film 1 of the antistatic surface protection film 10 according to the present invention and the method of bonding the release sheet 5 may be performed by a known method, and are not particularly limited. . Specifically, (1) the method of bonding the release sheet 5 together after apply|coating and drying the resin composition for forming the adhesive layer 2 on one side of the base film 1, and forming an adhesive layer, (2) ) After apply|coating and drying the resin composition for forming the adhesive layer 2 on the surface of the release sheet 5, and forming an adhesive layer, the method of bonding the base film 1 etc. are mentioned, but which method You may use it.

In addition, what is necessary is just to form the adhesive layer 2 on the surface of the base film 1 by a well-known method. Specifically, known coating methods such as reverse coating, comma coating, gravure coating, slot die coating, Mayer bar coating, and air knife coating can be used.

In addition, what is necessary is just to form the release agent layer 4 in the base material 3 similarly by a well-known method. Specifically, known coating methods such as gravure coating, Mayer bar coating, and air knife coating can be used.

The antistatic surface protection film 10 which concerns on this invention which has the said structure is the state which peeled the peeling sheet 5, and after bonding to the optical film which is a to-be-adhered body, the surface potential at the time of peeling from the optical film is +0 It is preferable that it is .7 kV - -0.7 kV. Moreover, it is more preferable that a surface potential is +0.5 kV - -0.5 kV, and it is especially preferable that a surface potential is +0.1 kV - -0.1 kV.

It is sectional drawing which shows the state which peeled the peeling sheet from the antistatic surface protection film of this invention.

By peeling the release sheet 5 from the antistatic surface protection film 10 shown in Fig. 1, the component of the antistatic agent (symbol 7) contained in the release agent layer 4 of the release sheet 5 is converted into the antistatic surface protection film It is transferred to the surface of the pressure-sensitive adhesive layer (2) of (10) and exists only on the surface of the pressure-sensitive adhesive layer. For this reason, in FIG. 2, the component of the antistatic agent transcribe|transferred to the surface of the adhesive layer 2 of the antistatic surface protection film 11 in the state which peeled the peeling sheet is typically shown by the dot of the code|symbol 7.

In the antistatic surface protection film according to the present invention, when the antistatic surface protection film 11 in a state in which the release sheet shown in Fig. 2 has been peeled is bonded to an adherend, the static electricity present only on the surface of the pressure-sensitive adhesive layer 2 The component of the inhibitor comes into contact with the surface of the adherend. For this reason, the peeling electrification voltage at the time of peeling an antistatic surface protection film from a to-be-adhered body again can be suppressed low.

3 is a cross-sectional view showing an embodiment of the 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 the adhesive layer 2 is interposed therebetween and is bonded to the optical component 8 as an adherend in a state where it is exposed. .

That is, the optical component 20 by which the antistatic surface protection film 11 in the state which peeled the peeling sheet from the antistatic surface protection film 10 of this invention was bonded by FIG. 3 is shown. Examples of the optical component include optical films such as a polarizing plate, a retardation plate, a lens film, a polarizing plate combined with a retardation plate, and a polarizing plate combined with a lens film. Such optical components are used as constituent members of liquid crystal display devices such as liquid crystal display panels and optical system devices of various instruments. Moreover, as an optical component, films for optics, such as an antireflection film, a hard-coat film, and the transparent conductive film for touch panels, are also mentioned. In particular, charging applied to the antifouling surface of an optical film such as a low-reflection polarizing plate (LR polarizing plate) or anti-glare low-reflection polarizing plate (AG-LR polarizing plate) whose surface is antifouling with a silicone compound or fluorine compound, etc. It can be used suitably as a prevention surface protection film.

According to the optical component of the present invention, when peeling and removing the antistatic surface protection film 11 in a state in which the release sheet is peeled off from the optical component (optical film) as an adherend, the peeling electrification voltage can be suppressed sufficiently low, There is no fear of destroying circuit components such as driver ICs, TFT elements, and gate line driving circuits, and the production efficiency in the process of manufacturing a liquid crystal display panel or the like can be improved, and the reliability of the production process can be maintained.

Example

Next, the present invention will be described in more detail by way of Examples.

(Example 1)

(Production of antistatic surface protection film)

10 parts by weight of addition reaction silicone (manufactured by Toray Dow Corning Co., Ltd., product name: SRX-211), 1.0 parts by weight of lithium bis(fluorosulfonyl)imide, 90 parts by weight of a 1:1 mixed solvent of toluene and ethyl acetate , platinum catalyst (manufactured by Toray Dow Corning Co., Ltd., product name: SRX-212) 0.06 parts by weight were mixed and stirred and mixed to prepare a paint for forming a release agent layer of Example 1. Polyethylene laminate prepared by laminating one side of high quality paper with a basis weight of 53 g so that the thickness of the polyethylene layer becomes 20 μm. It was coated with a Mayer bar as much as possible, and dried in a hot air circulating oven at 130° C. for 1 minute to obtain a release sheet of Example 1.

On the other hand, 40% acetic acid of the pressure-sensitive adhesive polymer of Example 1 consisting of a copolymer 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. With respect to 100 parts by weight of the ethyl solution, 2 parts by weight of an isocyanate-based curing agent (Coronate (registered trademark) HX manufactured by Tosoh Corporation) was stirred and mixed to prepare a pressure-sensitive adhesive composition of Example 1.

The pressure-sensitive adhesive composition of Example 1 prepared on the surface of a polyethylene terephthalate film having a thickness of 38 μm was applied to a thickness of 20 μm after drying, and then dried in a hot air circulation oven at 100° C. for 2 minutes to form a pressure-sensitive adhesive layer. . Then, the release sheet of Example 1 manufactured above was bonded together on the surface of this adhesive layer through the release agent layer (silicone-treated surface), and the laminated|multilayer film was obtained. The obtained laminated|multilayer film was heat-retained in 40 degreeC environment for 5 days, the adhesive layer was hardened, and the antistatic surface protection film of Example 1 was obtained.

(Example 2)

The addition reaction silicone of Example 1 was manufactured by Shin-Etsu Chemical Co., Ltd., product name: KS-847H, and the platinum catalyst was manufactured by Shin-Etsu Chemical Industries, Ltd., product name: CAT PL-50T, and the addition amount was 0.1 parts by weight, An antistatic surface protection film of Example 2 was obtained in the same manner as in Example 1 except that lithium bis(trifluoromethanesulfonyl)imide was used instead of lithium bis(fluorosulfonyl)imide.

(Comparative Example 1)

A surface protection film having no peeling antistatic performance of Comparative Example 1 was obtained in the same manner as in Example 1 except that the lithium bis(fluorosulfonyl)imide of Example 1 was not used.

(Comparative Example 2)

10 parts by weight of addition reaction silicone (manufactured by Toray Dow Corning Co., Ltd., product name: SRX-211), 90 parts by weight of a 1:1 mixed solvent of toluene and ethyl acetate, platinum catalyst (manufactured by Toray Dow Corning Co., Ltd., product name: SRX-212) 0.06 parts by weight was mixed and stirred and mixed to prepare a paint for forming a release agent layer of Comparative Example 2. Polyethylene laminate prepared by laminating polyethylene on one side of high quality paper with a basis weight of 53 g to a thickness of 20 μm. It apply|coated, it dried in 130 degreeC hot-air circulation type oven for 1 minute, and the release sheet of Comparative Example 2 was obtained.

On the other hand, with respect to 100 parts by weight of a 40% ethyl acetate solution of the pressure-sensitive adhesive polymer of Example 1, 3 parts by weight of a 10% ethyl acetate solution of lithium bis(fluorosulfonyl)imide, an isocyanate curing agent (Coronate manufactured by Tosoh Corporation (registered) Trademark) 2 parts by weight of HX) were stirred and mixed to prepare the pressure-sensitive adhesive composition of Comparative Example 2, applied to the surface of a polyethylene terephthalate film having a thickness of 38 μm so that the thickness after drying was 20 μm, followed by hot air at 100° C. The pressure-sensitive adhesive layer was formed by drying in a circulating oven for 2 minutes. Then, the release sheet of the comparative example 2 manufactured above was bonded together on the surface of this adhesive layer through the release agent layer (silicone-treated surface), and the laminated|multilayer film was obtained. The obtained laminated|multilayer film was heat-retained in 40 degreeC environment for 5 days, the adhesive layer was hardened, and the antistatic surface protection film of the comparative example 2 was obtained.

Hereinafter, the method and result of an evaluation test are shown. The surface protection film used in the method of the evaluation test is an antistatic surface protection film in Examples 1-2 and Comparative Example 2, and the surface protection film which does not have peeling antistatic performance in Comparative Example 1.

<Measuring method of peeling force of a peeling sheet>

A sample of the surface protection film is cut to a width of 50 mm and a length of 150 mm. The strength when the release sheet was peeled in the 180° direction at a peel rate of 300 mm/min using a tensile tester under a test environment of 23° C. × 50% RH was measured, and this was measured by measuring the peel force (N/50) of the release sheet. mm).

<Measuring method of adhesive strength of surface protection film>

An anti-glare low-reflection treatment polarizing plate (AG-LR polarizing plate) was bonded to the surface of the glass plate with a double-sided adhesive tape using a bonding machine. Then, after cutting to the polarizing plate surface to width 25mm and bonding the surface protection film in the state which peeled the peeling sheet, it stored in the test environment of 23 degreeC x 50 %RH for 1 day. Then, the intensity|strength at the time of peeling a surface protection film in 180 degree direction at the peeling speed of 300 mm/min using a tensile tester was measured, and this was made into adhesive force (N/25 mm).

(Method for measuring the surface resistivity of the pressure-sensitive adhesive layer)

After peeling the release sheet from the sample of the surface protection film, the surface resistivity (Ω/□) of the pressure-sensitive adhesive layer was applied using a high-performance high resistivity meter (Hirestar (registered trademark)-UP manufactured by Mitsubishi Chemical Analytech) The measurement was performed under the conditions of a voltage of 100 V and a measurement time of 30 seconds.

<Measuring method of peeling electrification voltage of surface protection film>

An anti-glare low-reflection treatment polarizing plate (AG-LR polarizing plate) was bonded to the surface of the glass plate with a double-sided adhesive tape using a bonding machine. Then, after cutting to the polarizing plate surface to width 25mm and bonding the surface protection film in the state which peeled the peeling sheet, it stored in the test environment of 23 degreeC x 50 %RH for 1 day. Then, while peeling the surface protection film at a peeling speed of 40 m/min using a high-speed peel tester (manufactured by Tester Industries), the surface potential of the polarizing plate surface was measured every 10 ms using a surface electrometer (manufactured by Keyence Co., Ltd.). At this time, the maximum value of the absolute value of the surface potential was taken as the peel electrification voltage (kV).

<Method of confirming surface contamination of surface protection film>

An anti-glare low-reflection treatment polarizing plate (AG-LR polarizing plate) was bonded to the surface of the glass plate with a double-sided adhesive tape using a bonding machine. Then, after cutting to the polarizing plate surface to width 25mm and bonding the surface protection film of the state which peeled the peeling sheet, it stored in the test environment of 23 degreeC x 50%RH for 3 days and 30 days. Then, the surface protection film was peeled and the stain|pollution|contamination property of the surface of a polarizing plate was observed visually. As a criterion for determining the surface contamination property, the case where there was no contamination migration in the polarizing plate was taken as (○), and the case where the contamination migration was confirmed in the polarizing plate was taken as (x).

Table 1 shows the measurement results of the obtained antistatic surface protection film of Examples 1 and 2, the surface protection film having no peeling antistatic performance of Comparative Example 1, and the antistatic surface protection film of Comparative Example 2. "2EHA" is 2-ethylhexyl acrylate, "HEA" is 2-hydroxyethyl acrylate, "#400G" is methoxypolyethylene glycol (400) methacrylate, and "AS agent (1)" is Lithium bis (fluorosulfonyl) imide, "AS agent (2)" is lithium bis (trifluoromethanesulfonyl) imide, "SRX-211" is SRX-211, "KS-847H" KS-847H, "SRX-212" means platinum catalyst SRX-212, and "PL-50T" means platinum catalyst CAT PL-50T, respectively. In addition, "4.7E10" of the surface resistivity means 4.7×10 ¹⁰ , and “overrange” means exceeding the measurement limit of the measuring device, and means 1.0×10 ¹³ Ω/□ or more.

The following can be seen from the measurement result shown in Table 1.

The antistatic surface protection films of Examples 1 and 2 according to the present invention have moderate adhesive strength, do not cause contamination on the surface of the adherend, and, after the antistatic surface protection film is once pasted to the adherend, in the adherend The peel electrification voltage at the time of peeling is low.

On the other hand, in the surface protection film having no peeling antistatic performance of Comparative Example 1 in which an antistatic agent was not added to the release agent layer, the peeling electrification voltage at the time of peeling from the adherend after the surface protection film was once bonded to the adherend was has risen

In addition, the antistatic surface protection film of Comparative Example 2 in which an antistatic agent was added to the pressure-sensitive adhesive layer was good because the antistatic surface protection film was once pasted to the adherend and then peeled off from the adherend due to its low peeling electrification voltage, Contamination to the adherend after peeling increased.

That is, in the surface protection film having no peeling antistatic performance of Comparative Example 1 and the antistatic surface protection film of Comparative Example 2, it is difficult to achieve both reduction in peeling electrification voltage and contamination to an adherend. On the other hand, after adding the antistatic agent to the release agent layer of the release sheet, the antistatic agent is transferred to the surface of the pressure-sensitive adhesive layer, and the antistatic surface protection film of Examples 1 and 2 in which the component of the antistatic agent exists only on the surface of the pressure-sensitive adhesive layer. Since there is an effect of reducing the peeling electrification voltage by adding a small amount of the antistatic agent, there is no contamination on the adherend, and a good antistatic surface protection film was obtained.

The antistatic surface protection film of the present invention is, for example, a polarizing plate, a retardation plate, an optical film such as a display lens film, etc. In the production process of various optical components, etc., in order to protect the surface of the optical component, etc. Can be used. In particular, even when used as an antistatic surface protection film for an optical film such as an LR polarizing plate or AG-LR polarizing plate whose surface is antifouling treated with a silicone compound or a fluorine compound, etc., once pasted to the adherend, the adherend When peeling, the amount of static electricity generation can be reduced.

The antistatic surface protection film of the present invention is easy to peel off the release sheet during use, has little contamination to the adherend, and does not deteriorate over time and has excellent peeling antistatic performance, so the workability and yield of the production process can be improved, so it has great industrial use value.

One… base film, 2... Adhesive layer, 3... description, 4... release agent layer, 5... release sheet, 7... antistatic agent, 8... An adherend (optical component), 10... Antistatic surface protection film, 11... The antistatic surface protection film in the state which peeled the peeling sheet, 20... The optical part which pasted the antistatic surface protection film together.

Claims (3)

A release sheet for an antistatic surface protection film capable of transferring an antistatic agent to the surface of the pressure-sensitive adhesive layer of the antistatic surface protection film in which an adhesive layer is formed on one side of a base film made of a resin having transparency, comprising:
The release sheet for an antistatic surface protection film is formed by laminating a release agent containing dimethylpolysiloxane on one side of a substrate and a release agent layer formed of a resin composition containing an antistatic agent,
The substrate is a substrate including paper, which has a thickness of 50 to 150 μm,
The pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive layer formed by crosslinking a (meth)acrylate copolymer,
The (meth) acrylate copolymer is made by copolymerizing a compound containing a polyoxyalkylene group,
The release sheet for an antistatic surface protection film, wherein the antistatic agent is lithium bis (fluorosulfonyl) imide or lithium bis (trifluoromethanesulfonyl) imide. The method of claim 1,
The release sheet for an antistatic surface protection film, wherein the pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive layer formed by crosslinking a (meth)acrylate copolymer with a curing agent. The antistatic surface protection film for optical films in which the peeling sheet for antistatic surface protection films of Claim 1 or 2 is bonded together.

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