KR20220148096A - Surface-protective film and optical component - Google Patents

Abstract

A surface protection film and an optical component are provided. The surface protection film (10) includes a base film (1) made of a resin having transparency, an antistatic agent layer (2) formed on one surface of the base film (1) and an adhesive layer (3) formed on the surface opposite to the antistatic agent layer (2) of the base film (1). The antistatic agent layer (2) includes a first layer (2a) containing a conductive polymer, and a second layer (2b) formed on the opposite to the base film (1) with respect to the first layer (2a) and containing nano carbon.

Description

Surface protection film and optical component {SURFACE-PROTECTIVE FILM AND OPTICAL COMPONENT}

The present invention relates to a surface protection film and an optical component.

When manufacturing and conveying optical products, such as optical films, such as a polarizing plate, retardation plate, a lens film for displays, an antireflection film, a hard coat film, and the transparent conductive film for touch panels, and a display using the same, the said optical film A surface protection film is pasted together on the surface, and prevention of surface contamination and a flaw in a post process is performed. The visual inspection of the optical film which is a product may be performed in the state which bonded the surface protection film to the optical film in order to reduce the effort 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 the single side|surface of a base film WHEREIN: In the manufacturing process of an optical product, in order to prevent the adhesion of the flaw or contamination to the surface of an optical product, it is generally used. A surface protection film is bonded to the film for optics through the adhesive layer of non-adhesive force. To make the pressure-sensitive adhesive layer non-adhesive, when peeling and removing the used surface protection film from the surface of the optical film, it can be easily peeled off, and the pressure-sensitive adhesive does not remain attached to the optical film of the product as an adherend (so-called, to prevent the occurrence of adhesive residue).

As a surface protection film, what provided the antistatic layer in the surface opposite to the adhesive layer of a base film is used many. By forming an antistatic layer on the surface of the surface protection film, static electricity generated during conveyance or handling of the optical product to which the surface protection film is bonded is suppressed in the manufacturing process of an optical product. Thereby, adsorption|suction of dust and dust in the environment is prevented, and it is made easy to perform an external appearance inspection in the state which bonded the surface protection film to the film for optics. In addition, when peeling and removing the used surface protection film from the polarizing plate or retardation plate inserted in the liquid crystal display panel, significant peeling electrification is suppressed, and the case where circuits such as driver ICs are destroyed is also suppressed.

In the antistatic layer on the surface of the surface protection film, various surfactants (nonionic, cationic, anionic, amphoteric surfactants) or ionic group-containing polymers, etc. are blended, metal or metal oxide deposition, or metal or metal oxide There are proposals such as a layer in which particles are blended.

An antistatic layer containing a surfactant or an ionic group-containing polymer is easily affected by environmental humidity, and has a high antistatic effect in a high-humidity environment, but has a problem in that the antistatic performance is significantly deteriorated in a low-humidity environment. . On the other hand, the antistatic layer to which metal or metal oxide particles are added is not easily affected by humidity in the environment, but it is difficult to show transparency, and can be used for optical products, especially for the purpose of inspecting in a state where a surface protection film is bonded. can't As an antistatic layer that is less affected by humidity in the environment and has transparency, an antistatic layer obtained by depositing a metal oxide such as indium tin oxide (ITO) or antimony tin oxide (ATO) is mentioned, but the cost for vapor deposition is high There are very high challenges.

Patent Document 1 discloses a surface protection film in which an antistatic layer is formed on one side of a polyester film, an antifouling layer is formed on the layer, and a non-adhesive layer is formed on the opposite side thereof. The antistatic layer contains a conductive polymer obtained by polymerizing thiophene and/or a thiophene derivative. However, when an antistatic layer is formed using the said conductive polymer, there exists a subject that problems, such as an increase (deterioration) of the surface resistivity accompanying oxidative deterioration and photodegradation, arise with the passage of time.

In order to solve the increase (deterioration) of the surface resistivity due to the passage of time, Patent Document 2 discloses a surface protection film containing polythiophenes in which the antistatic layer is doped with polyanilinesulfonic acid, polyanions, and a binder. has been proposed. This surface protection film is said to be able to suppress the increase (deterioration) of the surface resistivity over time by using polyanilinesulfonic acid in combination with the antistatic layer. hard to do

In Patent Document 3, an antistatic film having good transparency (total light transmittance) and good adhesion of the antistatic layer to the substrate, further comprising a conductive layer containing nano-carbon and a polymer, the surface resistivity of the antistatic film An antistatic film of 1×10 ¹¹ Ω/□ or less has been proposed. However, since this antistatic film uses nano-carbon, such as carbon nanotubes, as an antistatic agent, the rise of the surface resistance value with time is small, but in a moist heat environment (for example, 60 degreeC, relative humidity 90%) , etc.), there is a problem in that the surface resistance value rises (deteriorates).

Patent Document 4 proposes a thermosetting antistatic coating agent containing polythiophene and a conductive filler. This thermosetting antistatic coating agent exhibits little change in surface resistivity with time. However, this thermosetting type antistatic coating agent has the subject that the surface resistance value rises (deteriorates) when it is put in the high moist-heat state (the temperature of 60 degreeC, the conditions of 90% of relative humidity, etc.).

Japanese Patent Laid-Open No. 2000-026817 Japanese Republished Patent Publication No. 2018-012545 Japanese Patent Laid-Open No. 2012-166452 Japanese Laid-Open Patent Publication No. 2016-216714

One aspect of the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a surface protection film and an optical component in which an increase in surface resistance value does not easily occur.

One aspect of the present invention includes a base film made of a resin having transparency, an antistatic agent layer formed on one side of the base film, and an adhesive layer formed on the opposite side to the antistatic agent layer of the base film, The antistatic agent layer provides a surface protection film comprising a first layer containing a conductive polymer, and a second layer formed on the opposite side to the base film with respect to the first layer and containing nano carbon.

As for the said surface protection film, the peeling film may be pasted together on the opposite side to the said base film of the said adhesive layer.

The pressure-sensitive adhesive layer is preferably made of an acrylic pressure-sensitive adhesive.

Another aspect of this invention provides the optical component by which the said surface protection film was bonded.

One aspect of the present invention may provide a surface protection film and an optical component in which an increase in surface resistance value is unlikely to occur.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which showed the surface protection film of embodiment.
It is sectional drawing which showed the surface protection film in which the peeling film which pasted the peeling film to the surface protection film of embodiment was formed.
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.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which showed the surface protection film of embodiment. As shown in FIG. 1, as for the surface protection film 10 which concerns on embodiment, the antistatic agent layer 2 is formed in one surface (upper surface in FIG. 1) of the base film 1. As shown in FIG. The adhesive layer 3 is formed in the surface (lower surface in FIG. 1) on the opposite side to the antistatic agent layer 2 of the base film 1.

[base film]

As the base film 1, 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 surface protection film 10 to the optical component which is a to-be-adhered body. The base film 1 used as the base film 1 is preferably a film (polyester film) made of polyester such as polyethylene terephthalate, polyethylene naphthalate, polyethylene isophthalate, and polybutylene terephthalate. . 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. In addition, you may control the orientation angle of the axial method formed with the draw ratio of a stretched film and crystallization of a stretched film to a specific value.

"Transparency" means, for example, a visible light transmittance calculated as an average value of transmittances in the thickness direction in the entire wavelength region when measured within the measurement wavelength range of 380 nm to 780 nm is 50% or more (preferably 70 % or more, more preferably 80% or more). The light transmittance can be measured based on "a method for obtaining plastic-total light transmittance and total light reflectance" prescribed in JIS K 7375:2008.

Although the thickness of the base film 1 is not specifically limited, For example, the thickness of about 12-100 micrometers is preferable, if it is thickness of about 20-50 micrometers, handling is easy, and it is more preferable.

Moreover, you may give easily adhesion processing, such as surface modification by corona discharge, application|coating of an anchor-coat agent, to the surface of the base film 1 as needed.

[Antistatic agent layer]

As for the antistatic agent layer 2, the 1st layer 2a containing a conductive polymer and the 2nd layer 2b containing nano carbon are laminated|stacked in order from the base film 1 side, and is comprised. The 2nd layer 2b is formed in the opposite side to the base film 1 (upper side in FIG. 1) with respect to the 1st layer 2a.

Although the layer containing a conductive polymer has a possibility of an increase (deterioration) of the surface resistivity accompanying oxidative deterioration or photodegradation with time, etc., in the surface protection film 10, the surface of the 1st layer 2a By forming the second layer 2b containing nano-carbon on (the surface opposite to the base film 1), the problem of oxidative degradation or photodegradation of the first layer 2a containing a conductive polymer is overcome, have.

The layer containing nano-carbon has a possibility of increasing (deteriorating) the surface resistance value when placed in a moist heat environment (for example, conditions of 60° C., relative humidity of 90%, etc.), but in the surface protection film 10 , By the antistatic effect of the 1st layer 2a existing between the 2nd layer 2b and the base film 1, the subject of deterioration of the 2nd layer 2b in a wet heat environment is also overcome.

Examples of the conductive polymer used for the first layer 2a include polyaniline, polythiophene, polypyrrole, and derivatives thereof.

Polyaniline and its derivatives include polyaniline (manufactured by Aldrich), polyaniline (emeraldine salt) (manufactured by Aldrich), OMEGACON (registered trademark) D1033W, OMEGACON (registered trademark) NW-D102MT, OMEGACON (registered trademark) NW-F102ET , OMEGACON (registered trademark) NW-F101MEK (above, manufactured by Nissan Kagaku Corporation), Aquapass (registered trademark) 01X (manufactured by Mitsubishi Chemical Corporation), polyaniline toluene solution PANT (manufactured by Kaken Industries, Ltd.), etc. can be obtained. .

Polythiophene and its derivatives, commercially available, 3,4-ethylenedioxythiophene (BAYTRON (registered trademark) MV2), 3,4-polyethylenedioxythiophene/polystyrenesulfonate (BAYTRON (registered trademark) P, BAYTRON (registered trademark) C), BAYTRON (registered trademark) FE, BAYTRON (registered trademark) MV2, BAYTRON (registered trademark) P, BAYTRON (registered trademark) PAG, BAYTRON (registered trademark) PHC V4, BAYTRON (registered trademark) PHS, BAYTRON (registered trademark) PH, BAYTRON (registered trademark) PH500, BAYTRON (registered trademark) PH510 (above, manufactured by Stark), SEPLEGYDA (registered trademark) AS-Q, SEPLEGYDA (registered trademark) AS-D, SEPLEGYDA (registered trademark) AS-H (above, Shin-Etsu) Polymer Corporation), Conductive Coat S-983, Conductive Coat S-495, Conductive Coat S-948 (above, manufactured by Nakagyo Yushi Corporation), Denatron P-502RG, Denatron P-560ST, Denatron P-500NT, Denatron P- 200HC, Denatron P-800SL (above, manufactured by Nagase Chemtex), PED500 (made by Kaken Sangyo), etc. can be obtained.

As polypyrrole and its derivative(s), polypyrrole (made by Aldrich), SSPY (made by Kaken Sangyo), etc. can be obtained.

As the conductive polymer, polythiophene is preferable in terms of antistatic properties and colorability (color sensation). As polythiophene, polyethyleneoxythiophene is preferable, and polyethylenedioxythiophene (PEDOT) is especially good. Polyethylenedioxythiophene is preferably doped with polystyrenesulfonic acid (PSS) as a dopant. Polyethylenedioxythiophene doped with PSS has a property of being easily soluble in water, and has advantages in heat resistance, moisture resistance, and UV stability.

A conductive polymer may be used by one type, or may use multiple types together. In addition, for the purpose of improving the coatability of the antistatic agent to the base film 1, the adhesion of the antistatic agent layer to the base film, the film strength of the antistatic agent layer, and the durability of the film (abrasion resistance, solvent resistance, etc.), conductive polymer You may add binder resin, a crosslinking agent, a ultraviolet absorber, antioxidant, a leveling agent (wettability improving agent), an adhesiveness improver, etc. to this.

In order to form the 1st layer 2a, it is preferable to coat the conductive polymer to which binder resin was added rather than to form a film of a conductive polymer alone. As binder resin, an acrylic resin, an epoxy resin, a urethane resin, a phenol resin, a polyester resin, etc. are mentioned. You may add a crosslinking agent to binder resin in order to bridge|crosslink these resin (it is also mentioned hardening) as needed. As a crosslinking agent, an isocyanate compound, a melamine compound, an epoxy compound, a metal chelate compound, etc. are mentioned.

The method of forming the 1st layer 2a in the base film 1 may be a well-known method. For example, the coating material containing an antistatic agent (paint containing an antistatic agent and binder resin) to the base film 1 is coated according to a well-known coating method. The 1st layer 2a can be formed by solidifying the formed coating film by heating or ultraviolet irradiation. As the coating method, there are reverse coating, comma coating, gravure coating, slot die coating, Mayer bar coating, air knife coating, and the like.

Examples of the nano-carbon used for the second layer 2b include carbon nanotubes (CNT), graphene, fullerene, and the like. Carbon nanotubes include single-walled CNTs and multi-walled CNTs. Single-layered CNTs, multi-layered CNTs, graphene, and fullerenes all have excellent antistatic properties, but single-layered CNTs, graphene, and fullerenes are expensive, so multi-layered CNTs are easy to use. The second layer 2b is formed on the surface of the first layer 2a for the purpose of preventing the first layer 2a from being exposed to air. Thereby, since the case where the 1st layer 2a is directly exposed to air disappears, it becomes difficult for the 1st layer 2a to oxidatively deteriorate.

Since the film strength of nano carbon does not come out by itself, it is preferable to use it after adding a binder resin, a dispersing agent, etc. and making it into a paint. In addition, in nano-carbon, the coating property of the antistatic agent, the adhesion of the antistatic agent layer (adhesion to the first layer 2a), the film strength of the antistatic agent layer, the durability of the film (abrasion resistance, solvent resistance, etc.) The purpose of improving Therefore, you may add a crosslinking agent, a ultraviolet absorber, antioxidant, a leveling agent (wettability improving agent), an adhesive improving agent, etc.

One type of nano carbon may be used and may use several types together. As binder resin, an acrylic resin, an epoxy resin, a urethane resin, a phenol resin, a polyester resin, etc. are mentioned. You may add a crosslinking agent to binder resin in order to bridge|crosslink these resin (it is also mentioned hardening) as needed. As a crosslinking agent, an isocyanate compound, a melamine compound, an epoxy compound, a metal chelate compound, etc. are mentioned.

In order to form the 2nd layer 2b, you may use the coating material marketed as the coating material for antistatic agents. As a commercial item, Denatron C-300, Denatron CD-001 (above, Nagase Chemtex Co., Ltd. make), Kohl coat CS-3002, Kohl coat CS-3202 (above, Kohl coat company make), etc. are mentioned.

The method of forming the 2nd layer 2b on the surface of the 1st layer 2a may be a well-known method. For example, a coating material containing nano-carbon (a coating material containing nano-carbon and a binder resin) is applied to the surface of the first layer 2a using a known coating method. By solidifying the formed coating film by heating or ultraviolet irradiation, the 2nd layer 2b can be formed. As the coating method, there are reverse coating, comma coating, gravure coating, slot die coating, Mayer bar coating, air knife coating, and the like.

The thickness of the 1st layer 2a and the 2nd layer 2b is not specifically limited. The thickness of the first layer 2a is determined by the amount of the conductive polymer and the binder resin. The thickness of the second layer 2b is determined by the amount of nano-carbon and binder resin. The thickness of the first layer 2a and the second layer 2b is a state in which the first layer 2a and the second layer 2b are laminated, and the surface resistivity value is 10 to the 7th power (10 ⁷ ) to 10 Adjust it so that it is about the 9th power of (10 ⁹ ).

[Adhesive layer]

It is preferable that the pressure-sensitive adhesive layer 3 adheres to the surface of an adherend, is easily peeled off after use, and has characteristics that are difficult to contaminate the adherend. As an adhesive used for the adhesive layer 3, adhesives, such as an acrylic adhesive, a urethane adhesive, and a rubber-type adhesive, etc. are mentioned. As the pressure-sensitive adhesive, an adhesive resin such as polyethylene vinyl acetate resin can also be used. Especially, an acrylic adhesive and a urethane type adhesive are preferable.

As an acrylic adhesive, the adhesive which added the crosslinking agent to the (meth)acrylic-type polymer (acrylic resin composition) is preferable. The (meth)acrylic polymer includes a main monomer such as n-butyl acrylate, 2-ethylhexyl acrylate, isooctyl acrylate, and isononyl acrylate, and acrylonitrile, vinyl acetate, methyl methacrylate, ethyl acrylate, etc. A polymer obtained by copolymerizing a comonomer of acrylic acid, methacrylic acid, hydroxyethyl acrylate, hydroxybutyl acrylate, glycidyl methacrylate, or a functional monomer such as N-methylol methacrylamide is preferable. . As for the monomer composition which comprises a (meth)acrylic-type polymer, it is preferable that 50% or more of (meth)acrylic-type monomers are sufficient, and 100% of a (meth)acrylic-type monomer may be sufficient.

The crosslinking agent crosslinks the (meth)acrylic polymer. As a crosslinking agent, an isocyanate compound, an epoxy compound, a melamine compound, a metal chelate compound, etc. are mentioned. The amount of the crosslinking agent to be added may be determined in consideration of the type of (meth)acrylic polymer, the degree of polymerization, the amount of functional groups, and the like. Although the addition amount of a crosslinking agent is not specifically limited, It is preferable to set it as about 0.5-1.0 mass parts of crosslinking agents with respect to 100 mass parts of (meth)acrylic-type polymers.

As a urethane-type adhesive, the polyurethane-type resin containing a polyol component and a polyisocyanate component is preferable. What is necessary is just to select a polyurethane-type resin in consideration of adhesiveness, wettability, and to-be-adhered body contamination property. The polyol component and the polyisocyanate component are not particularly limited. Polyurethane-type resin may be used independently and may mix and use 2 or more types.

Examples of the polyol component include polyester polyol, polyether polyol, polycaprolactone polyol, polycarbonate polyol, and castor oil-based polyol. These polyol components may be used independently and may mix and use 2 or more types.

As the polyisocyanate component, an aliphatic polyisocyanate, an alicyclic polyisocyanate, an aromatic polyisocyanate, a multimer of diisocyanate, or the like is used. These polyisocyanate components may be used independently and may mix and use 2 or more types.

Commercially available polyurethane pressure-sensitive adhesives include Cyabaine (registered trademark) SH-101, SH-101M, SP-205, SP-220 (manufactured by Toyochem Co., Ltd.), Aracoat (registered trademark) FT100, FT200 (Arakawa Kagaku Kogyo Co., Ltd. product), UN1175, UN1176 (Daido Kasei Kogyo Co., Ltd. product) etc. are mentioned. The pressure-sensitive adhesive layer may be formed by crosslinking or curing a polyurethane pressure-sensitive adhesive.

A crosslinking catalyst may be added as an additive to the adhesive layer 3 in order to accelerate|stimulate a crosslinking reaction as needed. In order to improve the adhesiveness of the base film 1 and an adhesive to the adhesive layer 3 as needed, you may add adhesive improvers, such as a silane coupling agent, as an additive. You may add additives, such as an antistatic agent, antioxidant, and a ultraviolet absorber, to the adhesive layer 3 as needed.

Although limitation in particular is not carried out as for the thickness of the adhesive layer 3, For example, about 5-40 micrometers is preferable, and about 10-30 micrometers is more preferable. Moreover, 0.3 N/25 mm or less is preferable and, as for the adhesive force (low-speed adhesive force) at the peeling speed of 0.3 m/min with respect to the surface of a to-be-adhered body of a surface protection film, it is more preferable that it is 0.2 N/25 mm or less. Moreover, it is preferable that the adhesive force (high-speed adhesive force) at the time of a peeling speed|rate of 30 m/min is 0.8 N/25 mm or less. When high-speed adhesive force exceeds 0.8 N/25 mm, there exists a possibility that workability|operativity at the time of peeling a protective film after use may become inferior. A well-known method, such as a change of an adhesive composition, adjustment of the addition amount of a hardening|curing agent, adjustment of the addition amount of a tackifier, or adhesive force regulator, can be used for adjustment of adhesive force. What is necessary is just to match the adhesive force of the adhesive layer 3 with predetermined adhesive force by these methods.

As a method of forming the adhesive layer 3 on the surface of the base film 1, a well-known method can be used. 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.

2 : is sectional drawing which showed the surface protection film 11 in which the peeling film which pasted the peeling film 4 to the surface protection film 10 was formed. As shown in FIG. 2, as the peeling film 4, what is necessary is just to use a well-known peeling film. As the peeling film 4, you may use polyolefin films, such as a polyethylene film and a polypropylene film, a fluorine film, etc. as a film single-piece|unit. The release film 4 may be a release film in which the resin film is treated with a release agent (also referred to as a release agent). As a resin film, polyester films, such as PET (polyethylene terephthalate) and PEN (polyethylene naphthalate), and a polyamide film are mentioned, for example. As a mold release agent, a silicone resin, long-chain alkyl-group containing resin, a fluororesin, etc. are mentioned. Especially, the peeling film which processed the silicone type mold release agent to PET film is preferable.

The thickness of the release film is not particularly limited, but a release film having a thickness of 12 to 38 µm is often used in view of workability and cost.

What is necessary is just to perform the method of forming the adhesive layer 3 in the base film 1, and the method of bonding the peeling film 4 together to the adhesive layer 3 by a well-known method, and is not specifically limited. Specifically, (1) on one side of the base film 1, a resin composition for forming the pressure-sensitive adhesive layer 3 is applied and dried to form the pressure-sensitive adhesive layer 3, and then a release film is applied to the pressure-sensitive adhesive layer 3 After apply|coating and drying the resin composition for forming the adhesive layer 3 on the surface of the method of bonding (4), (2) peeling film 4, and forming the adhesive layer 3, the adhesive layer 3 Although the method of bonding the base film 1 together to ), etc. are mentioned, Any method may be used.

3 is a cross-sectional view showing an embodiment of the optical component of the present invention. 3 : has shown the optical component 20 to which the surface protection film 10 was bonded. As shown in FIG. 3, as for the surface protection film 11 (refer FIG. 2) in which the peeling film was formed, the peeling film 4 is peeled, and it will be in the state in which the adhesive layer 3 was exposed. This surface protection film (refer FIG. 1) is bonded by the adhesive layer 3 to the optical component 5 which is a to-be-adhered body.

As an optical component, optical films, such as a polarizing plate, a retardation plate, a lens film, a polarizing plate used as retardation plate, and a polarizing plate used as a lens film, are mentioned. 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.

According to the optical component of embodiment, in the state which bonded the surface protection film to the optical component (film for optics) which is a to-be-adhered body, there exists an antistatic agent layer on the surface protection film surface. For this reason, static electricity generated at the time of conveyance or handling of an optical component can be suppressed low. Therefore, the adsorption|suction of the substance which causes foreign substances, such as dust and dust in a process, is suppressed, and an optical component with few faults can be obtained. Moreover, when peeling and removing a surface protection film from an optical component, since peeling electrification voltage can be suppressed low, there is little possibility of destroying circuit components, such as a driver IC, a TFT element, and a gate line drive circuit. Therefore, for example, the production efficiency in the process of manufacturing a liquid crystal display panel etc. can be improved, and the reliability of a production process can be maintained.

Since the surface protection film of embodiment can suppress that the surface resistance value of the antistatic agent layer on the surface rises (deteriorates) also under exposure to external air or a moist heat environment, the said effect is difficult to change with time. Great value to use.

Example

Next, the present invention will be further described by way of Examples.

(Example 1)

An antistatic agent composition comprising a conductive polymer, a polythiophene-based antistatic agent (BAYTRON (registered trademark) PAG manufactured by Stark Corporation), an acrylic resin (Fesresin (registered trademark) SWX-079R manufactured by Takamatsu Yushi Corporation), and methylated An antistatic agent A containing a melamine crosslinking agent (Nikarak (registered trademark) MW-30HM manufactured by Nippon Carbide Co., Ltd.) at a solid content mass ratio of 30/100/10 was prepared.

As an antistatic agent composition containing nano-carbon, a carbon nanotube dispersion liquid (Denatron (trademark) CD-100 manufactured by Nagase Chemtex Co., Ltd.) and an acrylic resin (Feresin (registered trademark) SWX-079R manufactured by Takamatsu Yushi Co., Ltd.) and a methylated melamine crosslinking agent (Nikarak (registered trademark) MW-30HM manufactured by Nippon Carbide Co., Ltd.) at a solid content mass ratio of 10/100/10, an antistatic agent B was prepared.

A pressure-sensitive adhesive composed of a copolymer of 80 parts by mass of 2-ethylhexyl acrylate, 10 parts by mass of butyl acrylate, 7 parts by mass of methoxypolyethylene glycol (400) methacrylate, and 3 parts by mass of 2-hydroxyethyl acrylate prepared This adhesive is an acrylic adhesive. To 100 parts by mass of a 40% ethyl acetate solution of this adhesive, 0.3 parts by mass of lithium bis(trifluoromethanesulfonyl)imide as an antistatic agent and "Coronate (registered trademark) HX manufactured by Toso Corporation as an isocyanate curing agent" " 2 mass parts was added, it stirred and mixed, and the adhesive composition 1 was obtained.

The antistatic agent A was diluted 10-fold with water/ethanol (mass ratio of water/ethanol 50/50) to obtain a first coating material. The first paint was applied to the surface of a polyethylene terephthalate film (PET film, base film) having a thickness of 38 µm so that the thickness after drying became 0.15 µm, and dried in a hot air circulation type oven at 120° C. for 1 minute. Thereby, the 1st layer was formed.

Antistatic agent B was diluted 10-fold with water/ethanol (mass ratio of water/ethanol 50/50) to obtain a second coating material. The second coating material was applied on the surface of the first layer so that the thickness after drying might be set to 0.05 µm, and dried in a hot air circulation type oven at 120°C for 1 minute. Thereby, the 2nd layer was formed.

By the above process, the antistatic film in which the base film (PET film) / 1st layer (antistatic agent A) / 2nd layer (antistatic agent B) was laminated|stacked in this order was obtained.

On the surface of the PET film on which the antistatic agent layer is not laminated, the pressure-sensitive adhesive composition 1 was applied using an applicator to a thickness of 20 µm after drying, and dried in a hot air circulation type oven at 120°C for 3 minutes. Thereby, the adhesive layer was formed.

A release film (25 µm thick) (diafoil (registered trademark) MRF-25 manufactured by Mitsubishi Chemical Corporation) treated with a silicone release agent was bonded to the surface of the pressure-sensitive adhesive layer to obtain a surface protection film with a release film. The surface protection film with the obtained peeling film was aged at 40 degreeC for 3 days, and the surface protection film of Example 1 was obtained.

(Example 2)

Except having both the thickness of the 1st layer and the thickness of the 2nd layer being 0.1 micrometer, it carried out similarly to Example 1, and produced the surface protection film of Example 2.

(Example 3)

The surface protection film of Example 3 was produced in the same manner as in Example 1 except that the thickness of the first layer was 0.05 µm and the thickness of the second layer was 0.15 µm.

(Example 4)

Except for an adhesive and a hardening|curing agent, it carried out similarly to Example 2, and produced the surface protection film of Example 4.

As the pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive (Aracoat (registered trademark) FT200, manufactured by Arakawa Chemical Industries, Ltd.) was used instead of the acrylic pressure-sensitive adhesive. As the curing agent, instead of 2 parts by mass of “Coronate (registered trademark) HX manufactured by Toso Co., Ltd.”, “Aracoat (registered trademark) CL2503 manufactured by Arakawa Kagaku Kogyo Co., Ltd. (content rate of non-volatile matter of curing agent is 40% by mass)” 5.7 A mass part was used.

(Example 5)

In the same manner as in Example 2, except that a polyester resin (Vironal (registered trademark) MD-1480, manufactured by Toyobo) was used instead of the acrylic resin (Fesresin (registered trademark) SWX-079R, manufactured by Takamatsu Yushi). , a surface protection film of Example 5 was produced.

(Comparative Example 1)

Except that the thickness of the 1st layer was 0.2 micrometer and there was no 2nd layer, it carried out similarly to Example 1, and obtained the surface protection film of the comparative example 1.

(Comparative Example 2)

Except for having no 1st layer and having the thickness of the 2nd layer being 0.2 micrometer, it carried out similarly to Example 1, and the surface protection film of the comparative example 2 was obtained.

(Comparative Example 3)

It carried out similarly to Example 2 except having the antistatic agent layer of a single-layer structure instead of the antistatic agent layer of a two-layer structure, and produced the surface protection film of the comparative example 3.

The antistatic agent layer of a single layer structure was formed by coating the antistatic agent which mixed the antistatic agent A and the antistatic agent B so that it might become a solid content mass ratio of 50/50, and the thickness after drying might be set to 0.2 micrometer.

(Comparative Example 4)

Except having reversed the position of a 1st layer and a 2nd layer, it carried out similarly to Example 2, and obtained the surface protection film of the comparative example 4.

(Comparative Example 5)

Except having no 1st layer and 2nd layer, it carried out similarly to Example 1, and produced the surface protection film of Comparative Example 5.

Hereinafter, the method and result of an evaluation test are shown.

(Measuring method of surface resistivity value of surface protection film)

The surface specific resistance value (Ω/□) of the surface of the surface protection film was measured using a high-performance high resistivity meter (Hirestar (registered trademark)-UP manufactured by Mitsubishi Chemical Analytech) at an applied voltage of 100 V and a measurement time of 30 seconds. measured under conditions.

(Evaluation method of heat-and-moisture resistance)

After leaving the surface protection film to stand for a predetermined period (1 day or 30 days) on the conditions of the temperature of 60 degreeC and 90% of relative humidity, it was left to stand on the conditions of the temperature of 23 degreeC and 50% of relative humidity for 1 hour. The surface resistivity value (Ω/□) of the surface of the surface protection film was measured using a high-performance high resistivity meter (Hirestar (registered trademark)-UP manufactured by Mitsubishi Chemical Analytech) at an applied voltage of 100 V and a measurement time of 30 seconds. measured under conditions.

(Method for evaluating exposure resistance)

The surface protection film was left to stand for a predetermined period (1 day or 30 days) in a state in which the surface was exposed to air under conditions of a temperature of 23°C and a relative humidity of 50%. The surface resistivity value (Ω/□) of the surface of the surface protection film was measured using a high-performance high resistivity meter (Hirestar (registered trademark)-UP manufactured by Mitsubishi Chemical Analytech) at an applied voltage of 100 V and a measurement time of 30 seconds. measured under conditions.

<Measuring method of low-speed adhesive force of surface protection film>

The polarizing plate which used the TAC film for the polarizer protective film was bonded together on the surface of a glass plate using the bonding machine. Then, after bonding the surface protection film cut to 25 mm in width on the surface of a polarizing plate, 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 the direction of 180 degrees at the peeling speed of 0.3 m/min using a tensile tester was measured, and this was made into low-speed adhesive force (N/25mm).

<Measuring method of high-speed adhesive force of surface protection film>

The polarizing plate which used the TAC film for the polarizer protective film was bonded together on the surface of a glass plate using the bonding machine. Then, after bonding the surface protection film cut to 25 mm in width on the surface of a polarizing plate, 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 at the peeling speed of 30 m/min using a high-speed peeling tester (made by Tester Sangyo) was measured, and this was made into high-speed adhesive force (N/25 mm).

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

The polarizing plate which used the TAC film for the polarizer protective film was bonded together on the surface of a glass plate using the bonding machine. Then, after bonding the surface protection film cut to 25 mm in width on the surface of a polarizing plate, it stored in the test environment of 23 degreeC x 50 %RH for 1 day. Thereafter, the surface potential of the polarizing plate surface was measured every 10 ms using a surface electrometer (manufactured by Keyence Co., Ltd.) while peeling the surface protection film at a peeling rate of 30 m/min using a high-speed peel tester (manufactured by Tester Sangyo). The maximum value of the absolute value of the surface potential at the time of doing so was taken as the peel electrification voltage (kV).

<Method for confirming the surface contamination property of the surface protection film>

The polarizing plate which used the TAC film for the polarizer protective film was bonded together on the surface of a glass plate using the bonding machine. Then, after bonding the surface protection film cut to 25 mm in width on the surface of a polarizing plate, it stored in the test environment of 23 degreeC x 50 %RH for 3 days. Then, the surface protection film was peeled and the contamination property of the surface of a polarizing plate was observed visually. As a criterion for determining surface contamination property, the case in which there was no contamination transfer in the polarizing plate was set to "○" (Good), and the case in which contamination transfer was confirmed in the polarizing plate was set to "x" (No Good).

About the surface protection film of Examples 1-5 and Comparative Examples 1-5, the measurement result was shown to Tables 1-3. In Tables 1 to 3, "CNT" represents the ratio of the thickness of the second layer to the total thickness of the first layer and the second layer. "PEDOT" represents the ratio of the thickness of a 1st layer with respect to the total thickness of a 1st layer and a 2nd layer. "CNT/PEDOT(Mix)" represents the mixing ratio of the antistatic agent B and the antistatic agent A in the antistatic agent (mixture) when the antistatic agent layer of a single-layer structure is employ|adopted. "100 (50/50)" means that both the antistatic agent A and the solid content mass ratio of the antistatic agent B are 50 %.

"Antistatic agent layer lamination order" shows the lamination order of a 1st layer and a 2nd layer. "(circle)" shows that the lamination|stacking order of a base film, a 1st layer, and a 2nd layer is the order of "base film / 2nd layer / 1st layer."

"(circle)" in "acrylic resin" shows that the binder resin of a 1st layer and a 2nd layer is an acrylic resin. "(circle)" in "polyester resin" shows that the binder resin of a 1st layer and a 2nd layer is a polyester resin.

"(circle)" in "acrylic adhesive" shows that the acrylic adhesive was used as an adhesive. "(circle)" in "urethane adhesive" shows that the urethane-type adhesive was used as an adhesive. 1.0E+09 of the surface resistivity value represents 1.0×10 to the 9th power. 1.0E+13< indicates that the measurement limit (1.0×10 to the 13th power) of the measuring device (high-performance high-resistivity meter) is exceeded, and an overrange is obtained.

From the measurement results shown in Tables 1-3, the following things are known.

In the surface protection films of Examples 1-5, the surface resistance value of the antistatic agent layer did not rise (deteriorate) also under exposure to outdoor air and a moist heat environment.

On the other hand, in Comparative Example 1 in which the antistatic agent layer was formed only with the first layer (including a conductive polymer), an increase (deterioration) of the surface resistance value of the antistatic agent layer was observed when exposed to the outside air.

In Comparative Example 2 in which the antistatic agent layer was formed only with the second layer (including nano-carbon), an increase (deterioration) of the surface resistance value of the antistatic agent layer on the surface was observed in a moist heat environment.

In Comparative Example 3, in which the antistatic agent layer was not a two-layer structure but a single-layer structure composed of a mixture of antistatic agents A and B, the surface resistance value of the antistatic agent layer slightly increased (deteriorated) in a humid heat environment. The increase (deterioration) of the surface resistance value of the antistatic agent layer on the surface became large in the environment exposed to outdoor air.

In Comparative Example 4 in which the order of laminating the antistatic agent layer was reversed from that of Examples 1 to 5, an increase (deterioration) of the surface resistance value of the antistatic agent layer on the surface was observed in an environment exposed to external air and a humid heat environment.

In Comparative Example 5 in which the antistatic agent layer was not provided, since the surface resistance value of the surface protection film is high, it is estimated that static electricity is easily generated in the process.

The surface protection film of the embodiment, for example, in the production process of optical films such as polarizing plate, retardation plate, lens film, etc., various optical parts, etc. In order to protect the surface by bonding to the optical parts etc. have. The surface protection film of embodiment can suppress the raise (deterioration) of the surface resistance value of the surface antistatic agent layer also in external air exposure or a moist heat environment. The surface protection film of embodiment can suppress the static electricity which generate|occur|produces at the time of conveyance and handling of the optical product which bonded the surface protection film in the manufacturing process of an optical product, and can reduce the adsorption|suction of dust and dust in the environment. When the surface protection film of the embodiment peels and removes the used surface protection film from the polarizing plate or retardation plate inserted in the liquid crystal display panel, significant peeling and charging can be suppressed, so there is a fear of destroying circuits such as driver IC is less For this reason, the yield of a production process can be improved, and industrial use value is large.

One… Base film, 2... antistatic agent layer, 2a... 1st floor, 2b... 2nd floor, 3... Adhesive layer, 4... release film, 5... An adherend (optical component), 10... surface protection film, 11... The surface protection film in which the peeling film was formed, 20... optical components.

Claims (4)

A base film made of a resin having transparency;
An antistatic agent layer formed on one side of the base film;
A pressure-sensitive adhesive layer formed on the opposite side to the antistatic agent layer of the base film
to provide
The antistatic agent layer,
a first layer comprising a conductive polymer;
A surface protection film formed on the opposite side to the base film with respect to the first layer, and comprising a second layer containing nano-carbon. The method of claim 1,
The surface protection film by which the peeling film was pasted together on the opposite side to the said base film of the said adhesive layer. 3. The method according to claim 1 or 2,
The pressure-sensitive adhesive layer is a surface protection film made of an acrylic pressure-sensitive adhesive. The optical component to which the surface protection film of Claim 1 or 2 was stuck.

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