TWI752204B - Antistatic film, polarizing plate, touch panel and liquid crystal display device - Google Patents

Abstract

An antistatic film comprising "a base film made of a thermoplastic resin containing a polymer containing an alicyclic structure" and "an antistatic layer disposed on the base film", wherein the aforementioned antistatic film The layer includes an acrylate-based binder composition and metal oxide particles, and the residual double bond ratio Dre in the antistatic layer satisfies 2.5<Dre<6.1. Here, Dre=A _{C − H} /A _{C = O} ×Wa/(Wa+Wm)×100. A polarizing plate, a touch panel and a liquid crystal display device comprising the antistatic film are provided.

Description

Antistatic film, polarizing plate, touch panel and liquid crystal display device

The present invention relates to an antistatic film, a polarizing plate, a touch panel and a liquid crystal display device.

Liquid crystal display devices have the advantages of high image quality, thin shape, light weight, and low power consumption, and are widely used in, for example, televisions, personal computers, and car navigation. In the liquid crystal display device, the liquid crystal cell is arranged between two polarizers (ie, the incident-side polarizer and the output-side polarizer) arranged in such a manner that the transmission axes are perpendicular to each other. The voltage changes the alignment of the liquid crystal molecules to display images on the screen.

In addition, in recent years, in portable terminals such as mobile phones and tablet personal computers, liquid crystal display devices including touch panels have been widely used. In a liquid crystal display device including a touch panel, electric charges may be accumulated in components constituting the liquid crystal display device when a user touches the touch panel. Such accumulated charges may cause malfunction of the touch panel or disturb the driving control of the liquid crystal molecules of the liquid crystal cell, resulting in a reduction in image quality. Therefore, in order to control the accumulation of electric charges as described above, it is considered to provide an antistatic film on the liquid crystal display device.

Patent Document 1 describes an antistatic film including a base film and an antistatic layer, and having a haze value and a surface resistance value within a predetermined range.

"Patent Document" "Patent Document 1": International Publication No. 2016/063793 (corresponding publication: US Patent Application Publication No. 2017/238403)

In order to suppress the failure of the touch panel and further effectively suppress the disorder of the driving control of the liquid crystal molecules of the liquid crystal cell to obtain good image quality, the antistatic film is generally provided to extend the entire display range of the liquid crystal display device. Therefore, the user watches the image displayed by the liquid crystal display device through the antistatic film. Therefore, the antistatic film with high transparency is better.

However, if the haze value and the surface resistance value are set to specified ranges as in the technique of Patent Document 1, and it is intended to have both excellent transparency and antistatic properties, the light resistance of the antistatic film may deteriorate, and the antistatic film may be deteriorated. A case where the resistance value of the film after exposure to ultraviolet rays is significantly increased compared to the resistance value before exposure.

The present invention has been made in view of the above, and an object of the present invention is to provide an antistatic film having a low haze value, good transparency, good antistatic properties and excellent light resistance, a polarizing plate comprising the antistatic film, and a polarizing plate comprising the polarized light. A liquid crystal display device of a panel, a touch panel including the antistatic film, and a liquid crystal display device further including a touch panel including the antistatic film.

As a result of intensive research, the present inventors found that the light resistance of the antistatic film is related to the residual double bond ratio in the antistatic layer and the content ratio of metal oxide particles, and completed the present invention.

That is, the present invention is as follows.

[1] An antistatic film, which is an antistatic film used in a touch panel comprising a base film and an antistatic layer disposed on the base film, wherein the antistatic layer comprises an acrylate-based adhesive composition and a Metal oxide particles, the antistatic layer satisfies Formula 2.5<Dre<6.1, and the weight ratio of the metal oxide particles in the antistatic layer to the acrylate-based adhesive composition is 27% by weight or more and 200% by weight or less, Dre by formula based _{Dre = ((a C - H} / a C = O) × (Wa / (Wa + Wm))) of the residual double bond in the antistatic layer as defined in the × 100, a _{C - H} system The infrared absorption related to the out-of-plane bending vibration of the C-H bond _{of the acrylate structure in the infrared absorption spectrum of the antistatic layer, A C = O} is the acrylate structure in the infrared absorption spectrum of the antistatic layer. The sum of the infrared absorption related to the stretching vibration of the C=O bond with the C=O bond and the infrared absorption related to the stretching vibration of the C=O bond derived from the C=O bond of the acrylate structure, Wa is the aforementioned antistatic per unit volume The weight of the acrylate-based adhesive composition in the layer, Wm is the weight of the metal oxide particles in the aforementioned antistatic layer per unit volume.

[2] The antistatic film according to [1], wherein the antistatic layer has a single-layer structure, and the thickness of the antistatic layer is 0.5 μm or more and 10.0 μm or less.

[3] The antistatic film according to [1] or [2], wherein the antistatic layer has a surface resistance value of 1.0×10 ⁶ Ω/□ or more and 7.0×10 ⁸ Ω/□ or less.

[4] The antistatic film according to any one of [1] to [3], wherein the resistance value change ratio of the antistatic layer after a light resistance test through ultraviolet irradiation is 1.0 or more and less than 4.7.

[5] The antistatic film according to any one of [1] to [4], wherein the absolute value of the difference in refractive index between the antistatic layer and the base film is 0.1 or less.

[6] The antistatic film according to any one of [1] to [5], wherein the haze value is 0.3% or less, and the total light transmittance is 85% or more.

[7] The antistatic film according to any one of [1] to [6], wherein the base film is a base film made of a thermoplastic resin containing a polymer containing an alicyclic structure.

[8] The antistatic film according to any one of [1] to [7], wherein the base film has a first surface layer, an intermediate layer and a second surface layer in this order, wherein the intermediate layer contains ultraviolet rays For the absorber, the thickness of the base film is 10 μm or more and 60 μm or less, and the light transmittance of the base film at a wavelength of 380 nm is 10% or less.

[9] The antistatic film according to any one of [1] to [8], wherein the base film is an obliquely stretched film.

[10] The antistatic film according to [9], wherein the base film satisfies the following 1 and 2, 1) the in-plane retardation at a wavelength of 550 nm is 80 to 180 nm, and 2) the retardation axis is relative to the longitudinal direction is 45°±5°.

[11] The antistatic film according to any one of [1] to [10], which is a roll-shaped film.

[12] A polarizing plate comprising the antistatic film according to any one of [1] to [11].

[13] A touch panel comprising the antistatic film and touch panel member according to any one of [1] to [11].

[14] A touch panel comprising the polarizing plate and touch panel member as described in [12].

[15] A liquid crystal display device comprising the antistatic film and touch panel member according to any one of [1] to [11].

[16] A liquid crystal display device comprising the polarizing plate according to [12].

[17] A liquid crystal display device comprising the touch panel according to [13] or [14].

[18] The liquid crystal display device according to any one of [15] to [17], wherein a liquid crystal cell of the liquid crystal display device is connected to the antistatic layer.

[19] The liquid crystal display device according to any one of [15] to [18], wherein the liquid crystal display device is an IPS type.

According to the present invention, it is possible to provide an antistatic film having a low haze value, good transparency, good antistatic properties and excellent light resistance, a polarizing plate including the antistatic film, a liquid crystal display device including the polarizing plate, and a liquid crystal display device including the polarizing plate. The touch panel of the antistatic film further comprises a liquid crystal display device containing the touch panel of the antistatic film.

The following describes the embodiments and examples of the present invention in detail. However, the present invention is not limited to the embodiments and examples disclosed below, and can be implemented with arbitrary changes without departing from the scope of the patent application of the present invention and its equivalent scope.

In the following description, the so-called "long-shaped" film refers to a film having a length of 5 times or more relative to the width, preferably 10 times or more in length. Rolled lengths of film for storage or transport. The upper limit of the length of the elongated film is not particularly limited, but, for example, it may be set to 100,000 times or less.

In the following description, unless otherwise noted, the in-plane retardation Re of the film is represented by the value represented by Re=(nx−ny)×d. In addition, unless otherwise specified, the retardation Rth in the thickness direction of the film is a value represented by Rth=[(nx+ny)/2−nz]×d. Here, nx represents the direction perpendicular to the thickness direction of the film (in-plane direction) and is the refractive index in the direction giving the maximum refractive index, ny represents the in-plane direction and is the refractive index in the direction orthogonal to the nx direction, nz represents the refractive index in the thickness direction, and d represents the thickness of the layer. Unless otherwise noted, the measurement wavelength is 550nm.

In the following description, unless otherwise specified, the so-called directions of elements are "parallel", "perpendicular" and "orthogonal", and within the scope of not impairing the effect of the present invention, for example, the directions of ±5° may be included. error within the range.

In the following description, the longitudinal direction of the elongated film is generally parallel to the flow direction of the film on the production line.

In the following description, unless otherwise specified, the so-called "polarizing plate" and "1/4 plate" include not only rigid members but also flexible members such as resin films.

In the following description, unless otherwise specified, the angles formed by the optical axes of each film (the transmission axis of the polarizer, the retardation axis of the retardation film, etc.) in the components with many films are shown from the thickness direction. The angle of the aforementioned film.

In the following description, unless otherwise specified, the so-called bonding agent includes not only the bonding agent in the narrow sense (the bonding agent with a shear storage elastic modulus of 1MPa to 500MPa at 23°C after irradiation with energy rays or after heat treatment), Also included are adhesives with a shear storage elastic modulus of less than 1 MPa at 23°C.

In the following description, unless otherwise noted, the so-called slow axis of a thin film refers to the in-plane elliptic axis of the thin film.

[1. Outline of antistatic film]

The antistatic film of the present invention comprises a base film and an antistatic layer disposed on the base film.

FIG. 1 is a cross-sectional view schematically showing an embodiment of the antistatic film of the present invention.

As shown in FIG. 1 , the antistatic film 100 of this embodiment includes a base film 110 and an antistatic layer 120 disposed on the base film 110 . Although in this embodiment, the antistatic layer 120 is directly disposed on the surface of the base film 110 , any layer may be interposed between the base film and the antistatic layer.

[2. Substrate film]

As the base film, a film to be used as a base material of an optically stacked body should be appropriately selected and used. Among them, from the viewpoint that the antistatic film including the base film and the antistatic layer can be used as an optical film, a transparent film is preferable as the base film. Specifically, the total light transmittance of the base film is preferably above 80%, preferably above 85%, and particularly preferably above 88%.

The material of the base film is not particularly limited, and various resins can be used. Examples of resins include resins containing various polymers. Examples of the polymer include polymers having an alicyclic structure, cellulose esters, polyesters, polyvinyl alcohols, polyimides, UV-transmitting acrylates, polycarbonates, polysiloxanes, polyethersiloxanes, cyclic Oxypolymers, polystyrene, and combinations of these. Among them, from the viewpoint of transparency, polymers having an alicyclic structure and cellulose esters are preferred, and among them, from the viewpoints of transparency, low hygroscopicity, dimensional stability, light weight, and the like, A polymer having an alicyclic structure is preferred.

A polymer having an alicyclic structure, the structural unit of the polymer has an alicyclic structure. A polymer having an alicyclic structure may have an alicyclic structure in the main chain or may have an alicyclic structure in the side chain. Among them, from the viewpoints of mechanical strength and heat resistance, polymers having an alicyclic structure in the main chain are preferred.

As an alicyclic structure, a saturated alicyclic hydrocarbon (cycloalkane) structure, an unsaturated alicyclic hydrocarbon (cycloalkene, cycloalkyne) structure etc. are mentioned, for example. Among them, the cycloalkane structure and the cycloalkene structure are preferable from the viewpoints of, for example, mechanical strength, heat resistance, and the like, and among them, the cycloalkane structure is especially preferable.

The number of carbon atoms constituting the alicyclic structure, each alicyclic structure, its range is preferably 4 or more, preferably 5 or more, and preferably 30 or less, preferably 20 or less, especially 15 or less is better. By setting the number of carbon atoms constituting the alicyclic structure within this range, the mechanical strength, heat resistance, and moldability of the thermoplastic resin containing the polymer having the alicyclic structure can be highly balanced.

In the polymer having an alicyclic structure, the ratio of the structural unit having an alicyclic structure is appropriately selected according to the purpose of use. The proportion of the structural unit having an alicyclic structure in the polymer having an alicyclic structure is preferably 55% by weight or more, more preferably 70% by weight or more, and particularly preferably 90% by weight or more. When the ratio of the structural unit which has an alicyclic structure in the polymer which has an alicyclic structure is in this range, the transparency and heat resistance of the thermoplastic resin containing the polymer which has this alicyclic structure are favorable.

Examples of the polymer having an alicyclic structure include noralkene-based polymers, monocyclic cycloolefin-based polymers, cyclic conjugated diene-based polymers, and hydrogenated products thereof. Among these, noralkene-based polymers are particularly suitable because of their good moldability. Moreover, the polymer which has an alicyclic structure may be used individually by 1 type, and may be used in combination of 2 or more types in arbitrary ratios.

As the noralkene-based polymer, for example, those described in Japanese Patent Laid-Open No. H3-14882, Japanese Patent Laid-Open No. H3-122137, and Japanese Patent Laid-Open No. H4-63807 can be used. Specific examples of the noralkene-based polymer include ring-opening polymers of monomers having a noralkene structure and hydrogenated products thereof; addition polymers of monomers having a noralkene structure and hydrogenated products thereof; and such modifications. In the following description, a monomer having a noralkene structure may be referred to as a "noralkene-based monomer". Examples of the ring-opening polymer of the noralkene-based monomer include a ring-opening homopolymer of one monomer having a noralkene structure, and a ring-opening homopolymer of two or more monomers having a noralkene structure. Copolymers, and ring-opening copolymers of noralkene-based monomers and other monomers with which they can be copolymerized. In addition, as an example of the addition polymer of the noralkene-based monomer, an addition homopolymer of one kind of monomer having a noralkene structure, and two or more kinds of monomers having a noralkene structure can be mentioned. Addition copolymers of alkenes, as well as addition copolymers of noralkene-based monomers and other monomers that can be copolymerized with them. Among these, a hydrogenated product of a ring-opening polymer of a noralkene-based monomer is particularly suitable from the viewpoints of moldability, heat resistance, low hygroscopicity, dimensional stability, and light weight.

Examples of noralkene-based monomers include: noralkene; alkyl substituted derivatives of noralkene; alkylene substituted derivatives of noralkene; aromatic substituted derivatives of noralkene; and the like polar substituents, etc. Here, as a polar group, a halogen, a hydroxyl group, an ester group, an alkoxy group, a cyano group, an imido group, an imino group, a silicon group, etc. are mentioned, for example. These may be used individually by 1 type, and may be used in combination of 2 or more types at arbitrary ratios. Specific examples of such a noralkene-based monomer include 2-noralkene, 5-methyl-2-noralkene, 5,5-dimethyl-2-noralkene, and 5-ethyl yl-2-nor𦯉ene, 5-butyl-2-nor𦯉ene, 5-ethylidene-2-nor𦯉ene, 5-methoxycarbonyl-2-nor𦯉ene, 5-cyano-2 -nor𦯉ene, 5-methyl-5-methoxycarbonyl-2-nor𦯉ene, 5-phenyl-2-nor𦯉ene, 5-phenyl-5-methyl-2-nor𦯉ene, 5-hexyl-2-nor𦯉ene, 5-octyl-2-nor𦯉ene, 5-octadecyl-2-nor𦯉ene, etc.

In addition, examples of noralkene-based monomers include monomers in which one or more cyclopentadienes are added to noralkenes; alkyl-substituted derivatives of the monomers; alkylene-substituted derivatives of the monomers ; aromatic substituted derivatives of this monomer; and polar substituents of these, etc. Specific examples of such noralkene-based monomers include 1,4:5,8-dimethylbridge-1,2,3,4,4a,5,8,8a-octahydro-2,3 -Cyclopentadienonaphthalene, 6-methyl-1,4:5,8-dimethylbridge-1,4,4a,5,6,7,8,8a-octahydronaphthalene, 1,4:5 , 10:6,9-Trimethyl bridge-1,2,3,4,4a,5,5a,6,9,9a,10,10a-dodecahydro-2,3-cyclopentadienanthracene and so on.

Furthermore, as the noralkene-based monomer, for example, a monomer having a polycyclic structure which is a polymer of cyclopentadiene; an alkyl-substituted derivative of the monomer; an alkylene group of the monomer Substituted derivatives; aromatic substituted derivatives of this monomer; and polar substituents of these, etc. Specific examples of such a noralkene-based monomer include dicyclopentadiene, 2,3-dihydrodicyclopentadiene, and the like.

In addition, examples of noralkene-based monomers include adducts of cyclopentadiene and tetrahydroindene; alkyl-substituted derivatives of the adducts; alkylene-substituted derivatives of the adducts; Aromatic substituted derivatives of this adduct; and polar substituents of these, and the like. Specific examples of such noralkene-based monomers include 1,4-methano-1,4,4a,4b,5,8,8a,9a-octahydro-, 5,8-methano- 1,2,3,4,4a,5,8,8a-octahydro-2,3-cyclopentadienonaphthalene, etc.

The noralkene-based monomer may be used alone or in combination of two or more at any ratio.

Among the noralkene-based polymers, as structural units, those having X: bicyclo[3.3.0]octane-2,4-diyl-ethene structure and Y: paracyclo[4.3.0.1 ^2,5 ] Decane-7,9-diyl-ethylene structure, the content of these structural units is 90% by weight or more relative to the entire structural unit of the noralkene-based polymer, and the content ratio of X and the content ratio of Y The ratio of X:Y weight ratio is 100:0 ~ 40:60. By using such a polymer, a base film having no dimensional change over a long period and excellent stability of optical properties can be obtained.

As a monomer which has a structure of X as a structural unit, the nordicene type monomer which has a structure in which a five-membered ring is couple|bonded with a nordicene ring is mentioned, for example. Specific examples thereof include sancyclo[4.3.0.1 ^2,5 ]dec-3,7-diene (common name: dicyclopentadiene) and derivatives thereof (those having a substituent on the ring), 7,8-Benzotricyclo[4.3.0.1 ^2,5 ]dec-3-ene (common name: tetrahydrofuran) and its derivatives. Further, as the structure of a monomer having a structural unit Y include for example: shop ring [4.4.0.1 ^2,5 .1 ^7,10] deca-3,7-diene (common name: tetracyclododecene ) and its derivatives (those with substituents on the ring).

The polymerization of the above-mentioned monomers can be carried out by well-known methods. In addition, the above-mentioned monomers and any monomers can also be copolymerized or hydrogenated according to requirements, thereby obtaining the desired polymer. In the case of hydrogenation, the hydrogenation rate is 90% or more, preferably 95% or more, and more preferably 99% or more, from the viewpoints of thermal deterioration resistance and light deterioration resistance.

Furthermore, it can also be modified by using, for example, α,β-unsaturated carboxylic acid and its derivatives, styrene-based hydrocarbons, organosilicon compounds with olefinic unsaturated bonds and hydrolyzable groups, and unsaturated epoxy monomers, as required. The modifier modifies the obtained polymer.

The number average molecular weight (Mn) of the polymer having an alicyclic structure is preferably 10,000 or more, preferably 15,000 or more, especially 20,000 or more, preferably 200,000 or less, preferably 100,000 or less, especially Preferably below 50,000. When the number-average molecular weight is within this range, it is suitable that the mechanical strength and formability of the base film are highly balanced.

Here, the number-average molecular weight of the polymer having an alicyclic structure is measured as a polyisoprene-equivalent value by a GPC (gel permeation chromatography) method permeating a cyclohexane solvent.

In the thermoplastic resin containing the polymer having an alicyclic structure, the amount of the polymer having an alicyclic structure is preferably 50% by weight to 100% by weight, more preferably 70% by weight to 100% by weight. By constricting the amount of the polymer having an alicyclic structure within the aforementioned range, a substrate film having desired physical properties can be easily obtained.

The thermoplastic resin containing the polymer having an alicyclic structure may contain any components in combination with the polymer having an alicyclic structure as required. Examples of optional components include: ultraviolet absorbers; inorganic fine particles; stabilizers such as antioxidants, heat stabilizers, and near-infrared absorbers; resin modifiers such as lubricants and plasticizers; colorants such as dyes and pigments; Aging agents; etc. admixtures. An arbitrary component may be used individually by 1 type, and may be used in combination of 2 or more types at arbitrary ratios.

As the cellulose ester, lower fatty acid esters of cellulose (eg, cellulose acetate, cellulose acetate butyrate, and cellulose acetate propionate) are representative. The lower fatty acid means a fatty acid having 6 or less carbon atoms per molecule. Cellulose acetate includes cellulose triacetate (TAC) and cellulose diacetate (DAC).

The acetylation degree of cellulose acetate is preferably 50% to 70%, especially 55% to 65%. The weight average molecular weight is preferably 70,000 to 120,000, especially 80,000 to 100,000. In addition, the above-mentioned cellulose acetate may be partially esterified with fatty acids such as propionic acid and butyric acid as well as acetic acid. In addition, the resin constituting the base film may be contained in combination with cellulose acetate and cellulose esters other than cellulose acetate (cellulose propionate and cellulose butyrate). In this case, it is preferable that the whole of these cellulose esters satisfy the above-mentioned degree of acetylation.

As a preferable example of the film of cellulose triacetate, "TAC-TD80U" by Fujifilm Co., Ltd., and those disclosed in Association of Inventions Publication Technical Publication No. 2001-1745 are mentioned.

The base film may be a single-layer film including only one layer, or may be a multilayer film including two or more layers. Among them, the base film is preferably a multilayer film including a first surface layer, an intermediate layer containing an ultraviolet absorber, and a second surface layer in this order in the thickness direction. That is, it is preferable for the base film to have, for example, the following sequentially in the thickness direction: a first surface layer made of a thermoplastic resin containing a polymer having an alicyclic structure; a first surface layer comprising a polymer having an alicyclic structure and An intermediate layer made of a thermoplastic resin for ultraviolet absorbers; a second surface layer made of a thermoplastic resin containing a polymer having an alicyclic structure. In such a multilayer film, the exudation of the ultraviolet absorber contained in the intermediate layer can be suppressed by the first surface layer and the second surface layer.

In order to effectively suppress exudation, it is preferable that the first surface layer and the second surface layer do not contain an ultraviolet absorber. In addition, the polymer contained in the first surface layer, the polymer contained in the intermediate layer, and the polymer contained in the second surface layer may be the same or different. Therefore, the thermoplastic resin contained in the first surface layer and the thermoplastic resin contained in the second surface layer may also be different, but in terms of facilitating the formation of the layer body, the same is preferred. Usually, the first surface layer and the second surface layer are formed of the same thermoplastic resin as the thermoplastic resin contained in the intermediate layer, except that the ultraviolet absorber is not contained.

Examples of the ultraviolet absorber include organic ultraviolet absorbers such as tris-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, and acrylonitrile-based ultraviolet absorbers. Among them, the three-type ultraviolet absorber is preferable in that it is excellent in ultraviolet absorption performance at a wavelength of around 380 nm. In addition, as the ultraviolet absorber, one having a molecular weight of 400 or more is preferable.

As the tris'-based ultraviolet absorber, for example, a compound having a 1,3,5-tris' ring is preferably used. Specific examples of the tris(2)-based ultraviolet absorber include 2-(4,6-diphenyl-1,3,5-tris(2-yl)-5-[(hexyl)oxy]phenol, 2,4-Bis(2-hydroxy-4-butoxyphenyl)-6-(2,4-dibutoxyphenyl)-1,3,5-tris 𠯤 and the like. Moreover, as a commercial item of a ternary ultraviolet absorber, "TINUVIN 1577" (made by Ciba Specialty Chemicals) etc. are mentioned, for example.

Examples of benzotriazole-based ultraviolet absorbers include 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotri] oxazol-2-yl)phenol], 2-[3,5-bis(tertiarybutyl)-2-hydroxyphenyl]-5-chlorobenzotriazole, 2-(2H-benzotriazole-2 -yl) p-cresol, 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol, 2-benzotriazole-2 -yl-4,6-bis(tertiary butyl)phenol, 2-[5-chloro-(2H-benzotriazol-2-yl)]-4-methyl-6-(tertiary butyl) Phenol, 2-(2H-benzotriazol-2-yl)-4,6-di-tertiary butylphenol, 2-(2H-benzotriazol-2-yl)-4-(1,1 ,3,3-Tetramethylbutyl)phenol, 2-(2H-benzotriazol-2-yl)-4-methyl-6-(3,4,5,6-tetrahydrophthalimide Reaction of methyl) phenol, 3-[3-(2H-benzotriazol-2-yl)-5-tert-butyl-4-hydroxyphenyl]propionate/polyethylene glycol 300 compound, 2-(2H-benzotriazol-2-yl)-6-(straight-chain and side-chain dodecyl)-4-cresol, etc. As a commercial item of a triazole type ultraviolet absorber, "ADK STAB LA-31" (made by Asahi Denka Kogyo Co., Ltd.) etc. is mentioned, for example.

An ultraviolet absorber may be used individually by 1 type, and may be used in combination of 2 or more types in arbitrary ratios.

In the thermoplastic resin contained in the intermediate layer, the amount of the ultraviolet absorber is preferably 1 wt % or more, preferably 3 wt % or more, and preferably 8 wt % or less, more preferably 6 wt % or less. Here, the amount of the ultraviolet absorber refers to the total amount of these ultraviolet absorbers when two or more types of ultraviolet absorbers are used. By setting the amount of the ultraviolet absorber to be more than the lower limit of the aforementioned range, the penetration of ultraviolet rays having a wavelength of 200 nm to 370 nm can be effectively suppressed, and by setting the amount below the upper limit, since the yellow tinge of the film can be suppressed, the color tone can be suppressed. deterioration. In addition, by setting the amount of the ultraviolet absorber in the aforementioned range, since a large amount of the ultraviolet absorber is not contained, the reduction in the heat resistance of the thermoplastic resin can be suppressed.

As a method for producing a thermoplastic resin containing a thermoplastic resin and an ultraviolet absorber, the ultraviolet absorber-containing thermoplastic resin includes blending the ultraviolet absorber with the thermoplastic resin before production of the base film by a melt extrusion method, a solution casting method, or the like. method; method of using a master batch containing a high concentration of ultraviolet absorber; method of blending ultraviolet absorber with thermoplastic resin in the production of base film by melt extrusion method or solution casting method, etc.; etc. In these methods, the dispersibility of the ultraviolet absorber can be sufficiently improved by setting the amount of the ultraviolet absorber in the aforementioned range.

The glass transition temperature of the thermoplastic resin is preferably 70°C or higher, preferably 100°C or higher, more preferably 120°C or higher, and even more preferably 130°C or higher, among which 150°C or higher is preferred, especially 160°C The above is preferable, and the temperature is preferably 250°C or lower, and more preferably 180°C or lower. By setting the glass transition temperature of the thermoplastic resin to be equal to or higher than the lower limit value of the aforementioned range, the durability of the base film in a high temperature environment can be improved, and by setting the glass transition temperature to be equal to or lower than the upper limit value, the stretching treatment can be easily performed.

Furthermore, when the base film includes a first surface layer, an intermediate layer, and a second surface layer, the glass transition temperature TgA of the thermoplastic resin contained in the intermediate layer and the thermoplastic resin contained in the first surface layer and the second surface layer The glass transition temperature TgB of the resin preferably satisfies the relationship of TgB-TgA<15°C.

The light transmittance of the base film at a wavelength of 380 nm is preferably below 10%, preferably below 5%, especially preferably below 1%. In addition, the light transmittance of the base film at a wavelength of 280 nm to 370 nm is preferably 1.5% or less, and more preferably 1% or less. Thereby, since ultraviolet rays can be shielded by the antistatic film, in the liquid crystal display device provided with the antistatic film, damage to the polarizer and the liquid crystal cell caused by ultraviolet rays can be suppressed. Therefore, a decrease in the degree of polarization and coloring of the polarizer can be suppressed. Furthermore, the liquid crystal driving of the liquid crystal cell can be stabilized. The lower limit of the light transmittance of the base film at a wavelength of 380 nm and the light transmittance of the base film at a wavelength of 280 nm to 370 nm are ideally set to 0%.

This light transmittance must be measured using a spectrophotometer in accordance with JIS K 0115.

The base film may be an optically isotropic film or may be an optically anisotropic film. The base film may be, for example, an isotropic film having an in-plane retardation Re of 10 nm or less. When the base film is an isotropic film, the retardation Rth in the thickness direction of the base film is preferably 10 nm or less. In addition, when the base film is a film having optical anisotropy, the base film may be a film capable of functioning as a quarter-wave plate. When the base film layer functions as a quarter-wave plate, the in-plane retardation Re of the base film layer at a measurement wavelength of 550 nm is preferably 80 nm or more, more preferably 95 nm or more, and 180 nm or more. The following is preferable, and 150 nm or less is more preferable. If the in-plane retardation Re of the base film layer is within the above-mentioned range, when the antistatic film is incorporated into a liquid crystal display device, even when the installation position is changed with the normal direction of the display surface as the rotation axis, the transmission The image of polarized sunglasses still has less color tone change, so the visibility of the image of the liquid crystal display device is excellent. In addition, when the base film layer functions as a quarter-wave plate, the retardation Rth of the base film layer in the thickness direction at a measurement wavelength of 550 nm is preferably 50 nm to 225 nm.

Furthermore, when the base film layer is an elongated film that can function as a quarter-wave plate, the slow axis of the base film layer is relative to the longitudinal direction of the base film layer. It is preferable to set it so that it becomes the angle of the specified range. Hereinafter, the angle formed by the slow phase axis of the base film layer with respect to the longitudinal direction of the base film layer may be appropriately referred to as an "alignment angle". The range of the alignment angle is preferably 45°±5°, preferably 45°±3°, and particularly preferably 45°±1°. If an antistatic film having a base film layer having an alignment angle of such a range is used, a polarizing plate that can improve the visibility of an image transmitted through polarized sunglasses can be easily manufactured.

The dispersion of the in-plane retardation Re of the base film is preferably within 10 nm, preferably within 5 nm, and particularly preferably within 2 nm. In addition, the dispersion of retardation Rth in the thickness direction of the base film is preferably within 20 nm, preferably within 15 nm, particularly preferably within 10 nm. By condensing the dispersion of retardation Re and Rth within the aforementioned ranges, the display quality of the liquid crystal display device to which the antistatic film of the present invention is applied can be improved.

The thickness of the base film is preferably 10 μm or more, preferably 15 μm or more, especially 20 μm or more, and preferably 100 μm or less, preferably 60 μm or less, and more preferably 50 μm or less. By constricting the thickness of the base film within the aforementioned range, thinning of the antistatic film can be achieved. Furthermore, when the base film includes a first surface layer, an intermediate layer, and a second surface layer, the thickness of the intermediate layer is preferably 10 μm or more and 40 μm or less, and the total thickness of the first surface layer and the second surface layer is 5 μm. It is preferably more than or equal to 20 μm. In addition, the ratio of the thickness of the intermediate layer to the total thickness of the first surface layer and the second surface layer [(thickness of the intermediate layer)/(the total thickness of the first surface layer and the second surface layer)], the production stability From the viewpoint of , it is preferably 1 to 3 μm. Moreover, since the variation of the thickness of the intermediate layer can improve the image display property of the liquid crystal display device, it is preferable to set it within ±2.0 μm over the entire surface.

The base film can be produced, for example, by molding a thermoplastic resin into a film. As the molding method, for example, a hot melt molding method, a solution casting method, or the like can be used. Among them, it is preferable to use a heat-melt molding method in order to reduce the volatile components in the film. The heat-melt molding method can be classified into, for example, a melt extrusion molding method, a press molding method, an inflatable molding method, an injection molding method, a blow molding method, a stretch molding method, and the like in more detail. Among these, in order to obtain a base film excellent in mechanical strength, surface precision, and the like, it is preferable to use a melt extrusion molding method.

In particular, when a multilayer film having two or more layers is produced as a base film, it is preferable to use a co-extrusion method. For example, a substrate film having a multilayer structure of a first surface layer, an intermediate layer and a second surface layer can be obtained by combining the thermoplastic resin used to form the first surface layer, the thermoplastic resin used to form the intermediate layer with Manufactured by co-extrusion from a mold with a thermoplastic resin forming the second surface layer. Among such co-extrusion methods, the co-extrusion T-die method is preferred. In addition, as a co-extrusion T-die method, a feed module and a multi-manifold module can be mentioned.

In the co-extrusion T-die method, the melting temperature of the thermoplastic resin in the extruder with the T-die is preferably (Tg+80)°C or higher, preferably (Tg+100)°C or higher, and preferably (Tg+180)°C The following is preferable, and (Tg+150) ℃ or less is more preferable. Here, "Tg" represents the glass transition temperature of the thermoplastic resin, and when the base film includes a first surface layer, an intermediate layer, and a second surface layer, it represents the temperature of the thermoplastic resin contained in the first surface layer and the second surface layer. glass transition temperature. The flowability of the thermoplastic resin can be sufficiently improved by making the melting temperature in the extruder equal to or more than the lower limit value of the above-mentioned range, and the deterioration of the thermoplastic resin can be suppressed by making it equal to or less than the upper limit value.

Furthermore, in the melt extrusion molding method, the temperature of the thermoplastic resin in the extruder is preferably Tg～(Tg+100)°C at the resin inlet, and (Tg+50)～(Tg+170) at the extruder outlet. ℃, the mold temperature is (Tg+50)℃～(Tg+170)℃.

The manufacturing method of a base film may include the process of subjecting the film obtained by the said shaping|molding method to an extension process. By performing the stretching treatment, optical properties such as retardation can be exhibited in the base film.

The stretching treatment may be carried out by any method depending on the retardation to be expressed in the base film. For example, it is possible to perform a uniaxial stretching process in which the stretching process is performed only in a single direction, or a biaxial stretching process in which the stretching process is performed in two different directions. Further, in the biaxial stretching treatment, simultaneous biaxial stretching treatment in which stretching treatment is performed in two directions at the same time may be performed, or sequential biaxial stretching treatment in which stretching treatment is performed in a certain direction and then stretching treatment in another direction may be performed. In addition, the stretching treatment can be carried out in the longitudinal direction of the film in the longitudinal direction of the film, in the transverse direction of the film in the width direction of the film, and in the inclined direction which is neither parallel nor perpendicular to the film width direction. Any of the oblique extension treatments of the treatment may be performed in combination. As the method of the stretching treatment, for example, a roll method, a float method, a tenter method, etc. are mentioned.

When the base film is a film capable of functioning as a quarter-wave plate, among the above-mentioned stretching treatments, it is preferable to use an oblique stretching treatment. In the case of laminating an antistatic film and a polarizer with a base film as a quarter-wave plate, the transmission axis of the polarizer and the slow axis of the base film are usually set so that they are neither parallel nor perpendicular. It is carried out in a way that the specified angle intersects. At this time, in the base film obtained by the diagonal stretching process, since the slow axis appears in the oblique direction with respect to the width direction of the base film, it is not necessary to cut the antistatic film for lamination. A certain size can be effectively attached by the roll-to-roll method. As the stretching machine that can be used for the diagonal stretching process, for example, a tenter stretching machine is exemplified. The tenter stretching machine includes a horizontal uniaxial stretching machine, a simultaneous biaxial stretching machine, etc. Among them, the one that can continuously and obliquely stretch the long film is preferred.

The stretching temperature is based on the glass transition temperature Tg of the thermoplastic resin contained in the base film, and is preferably (Tg-30)°C or higher, preferably (Tg-10)°C or higher, and preferably (Tg+60)°C or lower , preferably below (Tg+50) ℃.

The stretching ratio is preferably 1.01 times to 30 times, preferably 1.01 times to 10 times, and more preferably 1.01 times to 5 times.

For the surface of the base film, surface treatment can be applied as required. For example, surface treatments such as plasma treatment, corona treatment, alkali treatment, coating treatment, etc. can be applied to the surface of the base film on the side where the antistatic layer is provided, in order to improve the adhesion with the antistatic layer.

Among the surface treatments, corona treatment is preferred. By corona treatment, the adhesion between the base film and the antistatic layer can be significantly improved. The irradiation amount of corona discharge electrons in the corona treatment is preferably 1 W/m ² /min to 1000 W/m ² /min. The water contact angle of the surface of the corona-treated substrate film is preferably 10° to 50°. The measurement of the water contact angle was measured in accordance with the JIS R3257 θ/2 method. In addition, after the corona treatment is applied, in order to make the appearance of the antistatic layer good, it is preferable to remove the static electricity of the base film before forming the antistatic layer on the surface to which the corona treatment has been applied.

[3. Antistatic layer]

The antistatic layer is a layer body disposed on the base film, and includes an acrylate-based adhesive composition and conductive metal oxide particles. In the antistatic layer, the metal oxide particles are aggregated so as to be linked in a chain shape to form a chain link body, and a conductive path is formed through the chain link body. Therefore, the antistatic film of the present invention can exert an antistatic function.

[3.1. Acrylic adhesive composition]

The antistatic layer contains an acrylate-based adhesive composition. The metal oxide particles can be held in the antistatic layer by the acrylate-based binder composition.

In the present invention, the "acrylate-based adhesive composition" means a combination of an acrylate-based adhesive polymer and an acrylate-based polymerizable monomer. The acrylate-based binder polymer is a polymer of a dimer or more obtained by polymerizing a monomer composition containing an acrylate-based polymerizable monomer. When such a polymerization reaction proceeds completely, the acrylate-based adhesive composition consists only of the acrylate-based adhesive polymer. That is, the acrylate-based adhesive composition may be composed of only an acrylate-based adhesive polymer, or may be composed of an acrylate-based adhesive polymer and an acrylate-based polymerizable monomer.

The acrylate-based polymerizable monomer means a monomer containing an acrylate structure. Here, the acrylate structure means the structure represented by H ₂ C=CH—(C=O)—O— in the acrylate.

Examples of acrylate-based polymerizable monomers include alkyl acrylates, esters of acrylic acid and polyhydric alcohols, esters of acrylic acid and polyhydroxy ethers, esters of acrylic acid and alcohols containing aromatic rings, polyfunctional acrylic urethanes, epoxy acrylate.

Examples of alkyl acrylates include acrylates of alkyl groups having 1 to 30 carbon atoms, and specific examples include methyl acrylate, ethyl acrylate, butyl acrylate, hexyl acrylate, and cyclohexyl acrylate. , 2-ethylhexyl acrylate, octyl acrylate, nonyl acrylate, dodecyl acrylate and octadecyl acrylate.

Examples of esters of acrylic acid and polyols include esters of acrylic acid and neotaerythritol (eg, neotaerythritol triacrylate, neotaerythritol tetraacrylate), and esters of acrylic acid and trimethylolpropane (eg : Trimethylolpropane triacrylate), esters of acrylic acid and ethylene glycol (eg: polyethylene glycol diacrylate), and esters of acrylic acid and glycerol.

Examples of esters of acrylic acid and polyhydroxy ethers include esters of acrylic acid and dipivalerythritol (for example, dipeutaerythritol tetraacrylate, dipeutaerythritol pentaacrylate, dipivalerythritol hexaacrylate, etc.) esters), acrylic acid and diethylene glycol (eg: diethylene glycol diacrylate) and acrylic acid and polyethylene glycol (eg: polyethylene glycol diacrylate).

Examples of esters of acrylic acid and alcohol containing an aromatic ring include bisphenoxyethanol perylene diacrylate, bisphenol A ethylene oxide di(meth)acrylate, and bisphenol A epoxy di(meth)acrylate. Acrylate.

As polyfunctional acrylate urethane, for example, diisocyanate and urethane reaction acrylate of ester of acrylic acid and polyhydroxy ether are mentioned. Specific examples of polyfunctional urethane acrylates include urethane-reactive acrylic acid of a mixture of isophorone diisocyanate, neotaerythritol triacrylate, and neotaerythritol tetraacrylate. ester.

As an acrylate type polymerizable monomer, the compound which has 3 or more of acrylate structures in 1 molecule is preferable. The acrylate-based adhesive composition can effectively reduce the surface resistance of the antistatic layer by using a polymer containing such a compound.

As a compound which has 3 or more acrylate structures in 1 molecule, for example, neotaerythritol triacrylate, neotaerythritol tetraacrylate, dipeutaerythritol tetraacrylate, dipeutaerythritol pentaacrylate may be mentioned. esters, dipivaloerythritol hexaacrylate, etc.

Moreover, as an acrylate type polymerizable monomer, the compound which has 3 or more of acrylate structures in 1 molecule can be used individually, and it can also be used combining two or more types in arbitrary ratios. For example, a combination of neotaerythritol triacrylate and neotaerythritol tetraacrylate, as well as dipivoerythritol tetraacrylate and dipivalerythritol pentaacrylate and dipivaloerythritol hexaacrylate can also be used The combination of alcohol esters is used as an acrylate-based polymerizable monomer for obtaining an acrylate-based binder polymer.

As a monomer composition for obtaining an acrylate-based adhesive polymer, it is preferable to use a compound containing 4 acrylate structures in one molecule, a compound containing 5 acrylate structures, and Monomer composition of compounds containing 6 acrylate structures.

Moreover, as a monomer for obtaining an acrylate-based adhesive polymer, arbitrary monomers other than the above-mentioned monomers may be used. As arbitrary monomers, one type may be used alone, or two or more types may be used in combination at an arbitrary ratio.

As an arbitrary monomer, if a compound having a carboxyl group and a polymerizable carbon-carbon double bond is used in 0.01% by weight to 5% by weight relative to the monomer composition for obtaining the acrylate-based adhesive polymer, since it can be It is better to effectively reduce the surface resistance value of the antistatic layer. Examples of the compound having a carboxyl group and a polymerizable carbon-carbon double bond include acrylic acid; methacrylic acid; crotonic acid; fumaric acid; itaconic acid; muconic acid; maleic anhydride and Half-esters of monoalcohols; compounds in which some of the hydroxyl groups of acrylates with hydroxyl groups such as dipeptaerythritol pentaacrylate and neotaerythritol triacrylate are added to the carbon-carbon double bond of acrylic acid; pentaacrylic acid diacrylate Compounds in which the hydroxyl group in the acrylates having hydroxyl groups, such as neotaerythritol ester and neotaerythritol triacrylate, reacts with dicarboxylic acid or carboxylic acid anhydride; etc. These may be used individually by 1 type, and may be used in combination of 2 or more types at arbitrary ratios.

The acid value of the monomer composition for obtaining the acrylate-based adhesive polymer is preferably 0.01 mgKOH/g to 0.5 mgKOH/g. The surface resistance value of the antistatic layer can be effectively reduced by setting the acid value of the monomer composition used to obtain the acrylate-based adhesive polymer to be above the lower limit of the aforementioned range, and by setting the upper limit Below the value, the stability of the antistatic agent can be made good.

The acid value of the monomer composition can be measured by following JIS K0070 (Test methods for acid value, saponification value, ester value, iodine value, hydroxyl value, and unsaponifiable matter of chemical products) using brorevanillin blue for the indicator Measurement.

In the antistatic layer, the amount of the acrylate adhesive composition is preferably 30% by weight or more, preferably 40% by weight or more, especially 50% by weight or more, and preferably 100% by weight or less, The content is preferably 79% by weight or less, particularly preferably 78% by weight or less. By setting the amount of the acrylate-based adhesive composition in the aforementioned range, the adhesion between the antistatic layer and the base film can be improved, and the dispersibility of the metal oxide particles in the antistatic layer can be improved. Also, the thickness of the antistatic layer can be made uniform.

[3.2. Metal oxide particles]

Examples of the metal oxide contained in the metal oxide particles include tin oxide; tin oxide doped with antimony, fluorine or phosphorus; indium oxide; indium oxide doped with antimony, tin or fluorine; antimony oxide; titanium suboxide. In particular, antimony-doped tin oxide and antimony-doped indium oxide are preferred. In addition, these may be used individually by 1 type, and may be used in combination of 2 or more types at arbitrary ratios.

The average particle size of the metal oxide particles is preferably 2 nm or more, more preferably 4 nm or more, especially 5 nm or more, and preferably 50 nm or less, preferably 40 nm or less, especially 10 nm or less. By making the average particle diameter of the metal oxide particles equal to or more than the lower limit of the above-mentioned range, the metal oxide particles are difficult to agglomerate in a granular form, so that the metal oxide particles are easily aggregated in a chain-like manner. And by setting it below an upper limit, since the haze of an antistatic layer can be reduced, the transparency of an antistatic layer can be improved. Furthermore, metal oxide particles can be easily linked to each other in a chain shape.

Here, the average particle diameter of the particles means the particle diameter at which the scattering intensity becomes the maximum, assuming that the particle diameter distribution measured by the laser diffraction method shows a normal distribution.

In addition, the surface of the metal oxide particles is preferably treated with a hydrolyzable organosilicon compound. The surface of the metal oxide particles to which such a treatment has been applied is usually modified by the hydrolyzate of the organosilicon compound. Therefore, the treatment of the surface of the metal oxide particles through which the hydrolyzable organosilicon compound is permeated may be referred to as "modification treatment" below. In addition, the metal oxide particles whose particle surfaces are treated with a hydrolyzable organosilicon compound are sometimes referred to as "modified particles". By performing such a modification treatment, the chain connection of the metal oxide particles can be strengthened, and the dispersibility of the metal oxide particles can be improved.

As a hydrolyzable organosilicon compound, the organosilicon compound represented by following formula (1) is mentioned, for example. R ¹ _a Si(OR ² ) _4−a (1) (In formula (1), R ¹ and R ² each independently represent a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 10 carbon atoms, and a carbon number 1 A group of a group consisting of organic groups of to 10, and a represents an integer of 0 to 3.)

In formula (1), a vinyl group, an acryl group, an alkyl group having 1 to 8 carbon atoms, etc. are ^{mentioned as preferable examples of R 1 .}

In addition, in formula (1), ^{preferable examples of R 2} include a hydrogen atom, a vinyl group, an aryl group, an acryl group, an alkyl group having 1 to 8 carbon atoms, and -CH ₂ OC _n H _2n+1 (n represents an integer of 1 to 4.) etc.

As the organosilicon compound represented by the formula (1), an organosilicon compound in which "a" is 0 or 1 is preferable. The organosilicon compound in which "a" in the formula (1) is a tetrafunctional of 0 is effective for maintaining the bonding system of the metal oxide particles. In addition, the organosilicon compound in which "a" in the formula (1) is a trifunctional 1 is effective in improving the dispersibility in the antistatic agent of the chain-linked metal oxide particles. In addition, the organosilicon compound in which "a" in the formula (1) is 0 or 1 trifunctional or more generally has a fast hydrolysis rate.

In addition, as the organosilicon compound represented by the formula (1), it is preferable to use a combination of a tetrafunctional organosilicon compound in which "a" is 0 and a trifunctional organosilicon compound in which "a" is 1. In the case of such combination, the molar ratio of the tetrafunctional organosilicon compound and the trifunctional organosilicon compound (tetrafunctional organosilicon compound/trifunctional organosilicon compound) is preferably above 20/80, and preferably 30 /70 or more is preferable, and 80/20 or less is more preferable, and 70/30 or less is more preferable. By not making the tetrafunctional organosilicon compound excessive, the metal oxide particles can be inhibited from being solidified and agglomerated, so that chain-like linkages can be easily formed. In addition, by keeping the trifunctional organosilicon compound in an excess, it is possible to suppress the generation of gel when the metal oxide particles are connected. Therefore, by combining the tetrafunctional organosilicon compound and the trifunctional organosilicon compound represented by the aforementioned molar ratio, the metal oxide particles can be effectively linked in a chain shape.

As described above, by combining a tetrafunctional organosilicon compound and a trifunctional organosilicon compound as the organosilicon compound represented by the formula (1), the metal oxide particles can be reinforced and linked to each other in a chain shape. The reason for this is not clear, but is presumed as follows. Since the activity of the connecting portion of the metal oxide particles is high, the organosilicon compound in which "a" is a tetrafunctional of 0 is easily adsorbed to the connecting portion of the metal oxide particle. In addition, since the tetrafunctional organosilicon compound is easily hydrolyzed, the hydrolysis proceeds simultaneously with the mixing of the alcohol, and a large amount of Si-OH is generated. On the other hand, the organosilicon compound in which "a" is 1-ter-functional has low solubility in water, and is dissolved in water by mixing with alcohol, and hydrolysis proceeds. Therefore, it can be considered that the trifunctional organosilicon compound is first adsorbed to the connecting portion of the metal oxide particles, and then reacts with Si—OH of the hydrolyzed tetrafunctional organosilicon compound.

Therefore, in the case of using a combination of a tetrafunctional organosilicon compound and a trifunctional organosilicon compound, it is preferable that these organosilicon compounds are not mixed with the aqueous dispersion of metal oxide particles at the same time, but firstly, the After the tetrafunctional organosilicon compound is mixed with the aqueous dispersion of metal oxide particles, the trifunctional organosilicon compound is mixed together with the alcohol.

Specific examples of the hydrolyzable organosilicon compound include tetraalkoxysilanes such as tetramethoxysilane and tetraethoxysilane; methyltrimethoxysilane, methyltriethoxysilane, methyl Triacetoxysilane, Methyltripropoxysilane, Ethyltrimethoxysilane, Ethyltriethoxysilane, Vinyltrimethoxysilane, Vinyltriethoxysilane, Vinyltriacetoxysilane Oxysilane, Phenyltrimethoxysilane, Phenyltriethoxysilane, Phenyltriacetoxysilane, γ-Chloropropyltrimethoxysilane, γ-Chloropropyltriethoxysilane, γ-Chloropropyltriethoxysilane -Chloropropyltripropoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-(β-glycidoxyethoxy Trimethoxysilane or trioxosilanes; dimethyldimethoxysilane, dimethyldiethoxysilane, phenylmethyldiethoxysilane, gamma-glycidoxypropylmethyldimethoxysilane Silane, γ-glycidoxypropylphenyldiethoxysilane, γ-chloropropylmethyldimethoxysilane, dimethyldiacetoxysilane, γ-methacryloyloxy Dialkoxysilanes such as propylpropylmethyldimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-aminopropylmethyldimethoxysilane, or diacylsilane; Trimethylchlorosilane, etc. These may be used individually by 1 type, and may be used in combination of 2 or more types at arbitrary ratios.

Next, a method for producing modified particles (metal oxide particles whose surfaces are treated with a hydrolyzable organosilicon compound) will be described. In the production method described below, the modified particles are produced in the state of a dispersion liquid.

In the method for producing modified particles, an aqueous dispersion of metal oxide particles to be treated is prepared. In this case, the concentration of the metal oxide particles in the aqueous dispersion is preferably 1% by weight or more, preferably 10% by weight or more, and preferably 40% by weight or less.

Next, the pH of the aqueous dispersion is adjusted to preferably 2 or more, more preferably 2.5 or more, more preferably 5 or less, and more preferably 4 or less. By making the pH of an aqueous dispersion more than the lower limit of the said range, since spherical aggregation of a metal oxide particle can be suppressed, it becomes easy to generate|occur|produce a chain connection. In addition, when the metal oxide particles are connected in a chain shape, the number of connections can be easily increased by setting the value to be equal to or less than the upper limit value. Therefore, since it is easy to make the average number of connections of the metal oxide particles to be 2 or more, it is easy to improve the antistatic performance of the antistatic film.

As a method of adjusting pH, the ion-exchange treatment method using an ion-exchange resin, the method of mixing an acid, etc. are mentioned. As the ion exchange resin, H-type cation exchange resin is preferable. Usually, the pH of the aqueous dispersion can be changed to be acidic by ion exchange treatment. In addition, when pH cannot be lowered sufficiently by ion exchange resin treatment alone, an acid may be mixed with an aqueous dispersion as required.

In addition, since deionization treatment is generally performed during the ion exchange treatment, the metal oxide particles are easily aligned in a chain shape.

After adjusting the pH, it is preferable to adjust the solid content concentration of the aqueous dispersion to an appropriate range by concentrating or diluting the aqueous dispersion of metal oxide particles. Specifically, the solid content concentration of the pH-adjusted aqueous dispersion is preferably adjusted to 10% by weight or more, preferably 15% by weight or more, more preferably 40% by weight or less, and preferably 35% by weight or less better. By setting the solid content concentration of the aqueous dispersion of metal oxide particles to be equal to or higher than the lower limit value of the aforementioned range, chain-like linkages of metal oxide particles can be easily formed. Therefore, since it is easy to make the average number of connections of the metal oxide particles as large as 3 or more, it is easy to improve the antistatic performance of the antistatic film. Furthermore, by setting it below an upper limit, the viscosity of the aqueous dispersion liquid of metal oxide particles can be reduced, and the mixing by stirring can be performed sufficiently. Therefore, the hydrolyzable organosilicon compound can be uniformly adsorbed to the metal oxide particles.

After that, the aqueous dispersion of metal oxide particles prepared as described above is mixed with the hydrolyzable organosilicon compound. As a hydrolyzable organosilicon compound, the compound represented by the said Formula (1) is mentioned.

The amount of the hydrolyzable organosilicon compound can be appropriately set according to factors such as the type of the organosilicon compound and the particle size of the metal oxide particles. The weight ratio of the metal oxide particles to the hydrolyzable organosilicon compound (organosilicon compound/metal oxide particle) is preferably 0.01 or more, 0.02 or more, 0.5 or less, and 0.3 or less. In the case of using two or more kinds of organosilicon compounds, the total amount of the organosilicon compounds preferably satisfies the range of the aforementioned weight ratio. By making the said weight ratio more than the lower limit of the said range, since the connection of the metal oxide particle linked in a chain can be suppressed from being broken in an antistatic agent, the antistatic film which has an excellent antistatic function can be obtained. In addition, since the dispersibility of the metal oxide particles in the antistatic agent can be improved, the viscosity of the antistatic agent can be reduced, and the time stability of the antistatic agent can be improved, so that the haze of the antistatic layer can be reduced. In addition, by setting the weight ratio to be below the upper limit value of the aforementioned range, since the layer of the hydrolyzate of the organosilicon compound that modifies the surface of the metal oxide particles can be suppressed from being excessively thick, the antistatic can be reduced. The surface resistance value of the layer.

And, in the manufacturing method of the modified particle demonstrated here, the process of hydrolyzing a hydrolyzable organosilicon compound is performed by mixing the aqueous dispersion liquid of a metal oxide particle and an alcohol. This step is usually performed after the step of mixing the aqueous dispersion of metal oxide particles and the hydrolyzable organosilicon compound. However, as mentioned above, in the case of using a combination of a tetrafunctional organosilicon compound and a trifunctional organosilicon compound, it is preferable to: after mixing the tetrafunctional organosilicon compound and the aqueous dispersion of metal oxide particles, The alcohol is mixed into this aqueous dispersion, and the trifunctional organosilicon compound is mixed into the aqueous dispersion of metal oxide particles at the same time or after mixing the aqueous dispersion of metal oxide particles and the alcohol.

As an alcohol, methanol, ethanol, n-propanol, isopropanol, butanol etc. are mentioned, for example. These alcohols may be used alone or in combination of two or more at any ratio. In addition, organic solvents such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether may be used in combination with the aforementioned alcohol.

The amount of the alcohol is adjusted so that the solid content concentration of the aqueous dispersion of the metal oxide particles mixed with the alcohol (including the total solid content of the organosilicon compound. The organosilicon compound is converted to silica.) is preferably condensed within a desired range. . Here, the desired range of the solid content concentration of the aqueous dispersion is preferably 3 wt % or more, more preferably 5 wt % or more, and preferably 30 wt % or less, more preferably 25 wt % or less.

The temperature at the time of hydrolysis is preferably 30°C or higher, more preferably 40°C or higher. The upper limit of the temperature at the time of hydrolysis is usually below the boiling point (about 100° C.) of the solvent used. By setting the temperature at the time of hydrolysis to be equal to or higher than the lower limit value, the time required for the hydrolysis can be shortened and the residual of the hydrolyzable organosilicon compound can be suppressed. The stability of the modified particles is good, so excessive aggregation of the particles can be suppressed.

Furthermore, an acid can also be mixed into the aqueous dispersion of metal oxide particles as a hydrolysis catalyst as required. Examples of the acid include hydrochloric acid, nitric acid, acetic acid, and phosphoric acid. In addition, an acid may be used individually by 1 type, and may be used in combination of 2 or more types at arbitrary ratios.

A suitable specific example of the operation at the time of hydrolyzing the organosilicon compound is as follows.

First, a tetrafunctional organosilicon compound in which "a" in formula (1) is 0 is mixed with an aqueous dispersion of metal oxide particles, and the aqueous dispersion is mixed with alcohol to hydrolyze the tetrafunctional organosilicon compound. After that, the aqueous dispersion is cooled to room temperature, and is mixed with the aforementioned alcohol again if necessary. Then, the organosilicon compound in which "a" in the formula (1) is 1-trifunctional is mixed with the aforementioned aqueous dispersion, and the temperature is raised to a temperature suitable for the aforementioned hydrolysis to perform hydrolysis. Thereby, the chain connection of the metal oxide particles can be maintained through the hydrolyzate of the tetrafunctional organosilicon compound. Furthermore, since the bonding of the hydrolyzate of the trifunctional organosilicon compound to the surface of the metal oxide particles is promoted, the dispersibility of the metal oxide particles can be improved.

The modified particles can be obtained by hydrolyzing the organosilicon compound as described above and modifying the surface of the metal oxide particles through the hydrolyzate of the organosilicon compound. Immediately after the hydrolysis, the modified particles can be obtained in a state of being dispersed in a dispersion liquid of a solvent such as water. The dispersion of the modified particles can be directly used in the preparation of the antistatic agent, but it can also be subjected to cleaning treatment or deionization treatment as required. By reducing the ion concentration by deionization treatment, a dispersion liquid of modified particles excellent in stability can be obtained. This deionization treatment can be performed, for example, using an ion exchange resin such as a cation exchange resin, an anion exchange resin, and a zwitterion exchange resin. In addition, the cleaning treatment can be performed, for example, using an ultrafiltration permeable membrane method or the like.

Furthermore, the obtained dispersion liquid of modified particles can also be used after being substituted with a solvent according to requirements. When solvent substitution is performed, the dispersibility with respect to the acrylate-based adhesive composition and polar solvent is improved. Therefore, the coatability of the antistatic agent can be improved. Therefore, the smoothness of the surface of the antistatic layer can be improved, and the occurrence of appearance defects such as streaks and unevenness in the antistatic layer can be suppressed. Furthermore, the scratch resistance, transparency, and adhesiveness of the antistatic layer can be improved, and the haze can be reduced. Also, the manufacturing reliability of the antistatic film can be improved.

In addition, the obtained dispersion of modified particles can also be mixed with water as required. By mixing with water, the number of linkages of the modified particles is generally increased and the conductivity of the obtained antistatic layer is increased. Therefore, since ^{an antistatic layer having a surface resistance value of about 10 2} Ω/□ to 10 ¹² Ω/□ can be obtained, an antistatic film excellent in antistatic property can be obtained.

The metal oxide particles (including modified particles) having the above-mentioned conductivity are usually linked in a chain shape in a dispersion liquid or an antistatic agent containing the metal oxide particles. Furthermore, since this connection is maintained even in the antistatic layer, conductive paths are formed in the antistatic layer by the connected metal oxide particles. Therefore, the antistatic layer is presumed to exhibit excellent antistatic properties. In addition, since the metal oxide particles are not aggregated into particles, but aggregated in a chain-like manner, it is difficult for the metal oxide particles to form aggregates as large as visible light scattering. Therefore, it is presumed that the haze of the antistatic layer containing such metal oxide particles can be reduced. However, the present invention is not limited to the aforesaid speculation.

The average number of connections of the metal oxide particles is preferably 2 or more, preferably 3 or more, and particularly preferably 5 or more. The antistatic performance of an antistatic layer can be improved by making the average number of connection of metal oxide particles more than the said lower limit. The upper limit of the average number of connections of the metal oxide particles is preferably 20 or less, more preferably 10 or less. By setting the average number of connections of the metal oxide particles to be equal to or less than the above-mentioned upper limit value, the production of chain-like metal oxide particles can be easily performed.

Here, the average number of connections of the metal oxide particles can be measured by the following method.

Photographs of chain-like linkages of metal oxide particles were taken with a transmission microscope. From this photograph, with respect to 100 chain-like connected bodies of metal oxide particles, the number of connections in each of the chain-like connected bodies was determined. Then, the average value of the number of connections of each chain-like connection body was calculated, and the average number of connections of the metal oxide particles was obtained by rounding off the first decimal place.

In the antistatic layer, the amount of metal oxide particles is usually 25 wt % or more, preferably 27 wt % or more, preferably 43 wt % or more, especially 58 wt % or more, and usually 200 wt % % or less, preferably 198 wt % or less, more preferably 98 wt % or less, particularly preferably 78 wt % or less. By making the amount of the metal oxide particles more than the lower limit value of the aforementioned range, the surface resistance value of the antistatic layer can be reduced, and the antistatic performance can be improved. In addition, by setting it below the upper limit value, the haze of the antistatic layer can be reduced, so that the transparency of the antistatic film can be improved, and the scratch resistance of the antistatic layer can be maintained at or above a certain value.

In the antistatic layer, the ratio of the metal oxide particles to the acrylate-based adhesive composition is within a specific range. The weight ratio of the metal oxide particles to the acrylate-based binder composition is 27% by weight or more, preferably 45% by weight or more, more preferably 60% by weight or more, and 200% by weight or less, and 100% by weight or less is preferable, and 80% by weight or less is more preferable. By making the ratio of the metal oxide particle with respect to the acrylate type adhesive composition more than the said lower limit, the surface resistance value of an antistatic layer can be made small, and an antistatic performance can be made favorable. Furthermore, by setting it below the said upper limit, since the haze of an antistatic layer can be reduced, the transparency of an antistatic film can be improved, and the scratch resistance of an antistatic layer can be maintained at a certain value or more.

[3.3. Arbitrary components]

The antistatic layer may contain any components other than the above-mentioned acrylate-based adhesive composition and metal oxide particles, as long as the effects of the present invention are not significantly impaired.

[3.4. Residual double bond ratio Dre of antistatic layer]

The residual double bond ratio Dre of the antistatic layer satisfies 2.5<Dre<6.1. Here, the residual double bond ratio Dre is defined by the following formula. Dre=((A _{C - H} /A _{C = O} )×(Wa/(Wa+Wm)))×100

In the above formulas, A _{C - H} infrared-based antistatic layer to absorb the C-H bond of the acrylate structural spectrum has an outer surface of the bending vibration associated infrared absorption, A _{C - O-based} antistatic layer the In the infrared absorption spectrum, the sum of the infrared absorption of the stretching vibration of the C=O bond of the acrylate structure and the infrared absorption of the stretching vibration of the C=O bond of the C=O bond of the acrylate structure, The weight ratio of the Wa/(Wa+Wm)-based acrylate-based binder composition to the acrylate-based binder composition and the metal oxide particles.

Wa is the content weight of the acrylate adhesive composition per unit volume of the antistatic layer, and Wm is the content weight of the metal oxide particles per unit volume of the antistatic layer.

Wa and Wm are generally used as the weight of the alkenoate-based polymerizable monomer and the weight of the metal oxide particles to be blended in the antistatic agent for obtaining the antistatic layer, respectively, and Wa/(Wa+Wm) is generally used as the antistatic agent The weight ratio of the acrylate-based polymerizable monomer to the acrylate-based polymerizable monomer and the metal oxide particles.

The infrared absorption spectrum of the antistatic layer can be measured, for example, by total reflection measurement (ATR method).

As the measuring device, "Spectrum Spotlight 300" manufactured by Perkinelmer was used.

If the acrylate is polymerized, the vinyl group in the acrylate structure will be converted into an ethyl extension, and the carbonyl group bonded to the vinyl group will become a carbonyl group bonded to the ethyl extension. The "C=O bond derived from the C=O bond of the acrylate structure" means the C=O bond bonded to the carbonyl group of the ethylidene group, which occurs due to the polymerization of the acrylate.

When the peak related to the stretching vibration of the C=O bond in the acrylate structure and the peak related to the stretching vibration of the C=O bond derived from the C=O bond of the acrylate structure are not separated and become a single peak The infrared absorption of this single peak can be regarded as the infrared absorption related to the stretching vibration of the C=O bond of the acrylate structure and the stretching vibration of the C=O bond derived from the C=O bond of the acrylate structure. The sum of the associated infrared absorptions.

As the value of A _{C - H} /A _{C = O , the area (area C - H} ) of the peak related to the out-of-plane bending vibration of the C-H bond possessed by the acrylate structure can be used divided by the value possessed by the acrylate structure. The value of the area of the peaks related to the stretching vibration of the C=O bond and the area of the peaks related to the stretching vibration of the C=O bond derived from the C=O bond of the acrylate structure (area _{C = O} ) value (area _{C - H} /area _{C = O} ).

In the infrared absorption spectrum, the peaks related to the out-of-plane bending vibration of the C-H bond of the acrylate structure usually appear around 810cm ⁻¹ . In addition, the peaks related to the stretching vibration of the C=O bond in the acrylate structure and the peaks related to the stretching vibration of the C=O bond derived from the C=O bond of the acrylate structure usually appear at 1720 cm ⁻¹ nearby.

The value of A _{C - H} /A _{C = O} depends on the amount of unreacted acrylate structures contained in the acrylate adhesive composition, and the value of Dre depends on the amount contained in the unit volume of the antistatic layer. The value depends on the amount of unreacted acrylate structures.

When the value of Dre satisfies 2.5<Dre<6.1, an antistatic film having good antistatic properties and excellent light resistance can be obtained. The antistatic property can be confirmed by measuring the surface resistance value of the antistatic layer. Excellent light resistance was confirmed by the fact that the resistance value change rate of the antistatic film after the light resistance test was small. The surface resistance value and the resistance value change rate will be described in detail later.

The reason why an antistatic film with good antistatic properties and excellent light resistance can be obtained by satisfying the value of Dre 2.5<Dre<6.1 is not clear, but is presumed as follows.

Although it can be said that the lower the resistance value of the antistatic layer is, the better the antistatic performance of the antistatic layer is, but it is presumed that the better the metal oxide particles are dispersed in the layer, the lower the resistance value of the antistatic layer is.

In the production process of the antistatic layer or in the light resistance test, it is presumed that if the acrylate-based binder polymer is formed by rapidly polymerizing the acrylate-based polymerizable monomer, the volume of the antistatic layer will be rapidly shrunk. Since the metal oxide particles of the acrylate-based adhesive composition are aggregated into a granular form, the resistance value of the antistatic layer increases. It is presumed that by setting the value of Dre to satisfy 2.5<Dre<6.1, the amount of the acrylate-based polymerizable monomer polymerized in the production process of the antistatic layer or in the light resistance test can be controlled so that the metal oxide particles do not As a result, it is possible to obtain an antistatic film with good antistatic properties and a small resistance value change rate after the light resistance test.

However, the present invention is not limited by the above speculation.

The value of Dre is greater than 2.5, preferably 3.2 or more, and more preferably 3.7 or more. By making the value of Dre so large, an antistatic film with good antistatic properties can be obtained.

The value of Dre is less than 6.1, preferably less than 5.4, more preferably less than 4.8. By making the value of Dre so small, the resistance value change rate of the antistatic film can be made smaller, and an antistatic film excellent in light resistance can be obtained.

The value of Dre can be controlled by adjusting the irradiation intensity and time of the active energy ray to be irradiated during the production process of the antistatic layer.

[3.5. Surface resistance value of antistatic layer]

The surface resistance value of the antistatic layer is preferably 1.0×10 ⁶ Ω/□ or higher, preferably 1.0×10 ⁷ Ω/□ or higher, more preferably 1.0×10 ⁸ Ω/□ or higher, especially 1.5×10 ⁸ Ω/□ or more is preferable, and preferably 7.0×10 ⁸ Ω/□ or less, preferably 6.0×10 ⁸ Ω/□ or less, especially 5.5×10 ⁸ Ω/□ or less.

The lower the surface resistance value of the antistatic layer, the better the antistatic property.

Since there is a tendency that "the smaller the residual double bond ratio Dre, the higher the surface resistance value; the larger the Dre value, the lower the surface resistance value", so by controlling the residual double bond ratio Dre, the surface resistance can be improved. The resistance value is set in the above-mentioned range.

The surface resistance value of the antistatic layer is measured by a measurement method in accordance with JIS K6911. As a measuring apparatus, "HIRESTA-UX MCP-HT800" manufactured by Mitsubishi Chemical Analytech Co., Ltd. was used.

[3.6. Rate of change of resistance value of antistatic layer]

According to the antistatic film of the present invention, the resistance value change rate of the antistatic layer after the light resistance test by ultraviolet irradiation can be made smaller.

Here, the resistance value change rate of the antistatic layer after the light resistance test means the numerical value measured according to the method described in the item (measurement method of initial resistance value) and item (light resistance test) of the following examples , the resistance value change rate is calculated from the resistance value (R1)/initial resistance value (R0) after the light resistance test.

In the antistatic film of the present invention, the resistance value change rate of the antistatic layer after the light resistance test through ultraviolet irradiation is preferably 1.0 or more, preferably more than 1.0, more preferably 1.7 or more, especially preferably 1.8 or more. , and preferably less than 4.7, preferably below 4.1, especially preferably below 3.5.

The more the residual double bond rate Dre is increased, the smaller the initial resistance value and the greater the resistance value change rate; the more the residual bond double bond rate Dre is decreased, the greater the initial resistance value is and the resistance value changes tend to be smaller. Therefore, by controlling the residual double bond ratio Dre, the initial resistance value and the resistance value change rate can be set within a specified range.

[3.7. Structure of antistatic layer]

The antistatic layer may have a multilayer structure having two or more layers, but it is preferable to have a single-layer structure consisting of only one layer. Since the antistatic layer has a single-layer structure, the antistatic layer can be easily fabricated and the thickness of the antistatic film can be reduced.

The thickness of the antistatic layer is preferably 0.5 μm or more, preferably 0.8 μm or more, especially 1.0 μm or more, and preferably 10.0 μm or less, preferably 5.0 μm or less, especially 3.0 μm or less. good.

The thickness of the antistatic layer was measured with an interferometric film thickness meter (“F20 film thickness measurement system” manufactured by Filmetrics).

[4. Physical properties and shape of antistatic film]

[4.1. Refractive index]

The absolute value of the refractive index difference between the antistatic layer and the base film is preferably 0.1 or less, preferably 0.07 or less, and particularly preferably 0.05 or less. By making the absolute value of the refractive index difference so small, the reflection of light at the interface between the base film layer and the antistatic layer can be suppressed, and as a result, the antistatic film can be made into one with excellent transparency, and the Suppresses the appearance of interference patterns of light on the antistatic film. In addition, since the coating unevenness and light spot unevenness of the antistatic layer can be hardly recognized, the appearance of the antistatic film can be easily improved.

[4.2. Haze value of antistatic film]

The haze value of the antistatic film is preferably below 0.3%, preferably below 0.2%, especially preferably below 0.1%. The lower limit of the haze value of the antistatic film is ideally 0%.

The haze value of the antistatic film can be measured using a haze meter (“HAZE-GARD II” manufactured by Toyo Seiki Co., Ltd.) in accordance with JIS K7136.

[4.3. Total light transmittance of antistatic film]

The total light transmittance of the antistatic film is preferably above 85%, preferably above 86%, especially preferably above 87%. The upper limit of the total light transmittance of the antistatic film should ideally be 100%.

The total light transmittance of the antistatic film must be measured with a UV/Vis spectrometer in the wavelength range of 380nm to 780nm.

The total light transmittance of the antistatic film is measured in accordance with JIS K7361-1. As a measuring device, a haze meter (“HAZE-GARD II” manufactured by Toyo Seiki Co., Ltd.) was used.

[4.4. Shape of antistatic film]

The shape of the antistatic film of the present invention is not limited, and it can be a long film or a film cut into a certain size. Generally, an antistatic film is produced as a long film from the viewpoint of improving production efficiency. When the antistatic film of the present invention is an elongated film, the film is usually wound into a roll shape. Also, in the case of manufacturing the antistatic film cut into a certain size, the antistatic film cut into a certain size is usually produced by cutting the long antistatic film into a desired shape.

[5. Manufacturing method of antistatic film]

The antistatic film of the present invention can be produced by coating an antistatic agent containing an acrylate-based polymerizable monomer and metal oxide particles on the aforementioned base film to form an antistatic layer.

Acrylate-based polymerizable monomers are usually polymerized by irradiation with active energy rays such as ultraviolet rays. Therefore, the antistatic agent preferably contains a photopolymerization initiator. As the photopolymerization initiator, for example, benzoin derivatives, diol condensed benzoyls, α-hydroxyacetophenones, α-aminoacetophenones, phosphine oxides, O-oximes Wait. Further, as commercially available photopolymerization initiators include, for example: benzophenone / amine, which meter Le ketone / benzophenone, thio 𠮿 port star ketone / amine combinations (product name: IRGACURE or DAROCUR etc., manufactured by Ciba-Geigy Corporation) etc. A photopolymerization initiator may be used individually by 1 type, and may be used in combination of 2 or more types in arbitrary ratios.

The amount of the photopolymerization initiator, relative to 100 parts by weight of the acrylate-based polymerizable monomer, is preferably 1 part by weight or more, preferably 2 parts by weight or more, especially 3 parts by weight or more, and 20 parts by weight or more. It is preferably below 10 parts by weight, especially preferably below 5 parts by weight. By setting the amount of the photopolymerization initiator in the aforementioned range, the polymerization efficiency of the polymerizable monomer can be favorably performed, and excessive mixing of the photopolymerization initiator can be avoided, and the initiation of photopolymerization caused by unreacted can be suppressed. The yellowing of the antistatic layer of the agent or the change of the physical properties of the film.

The antistatic agent must contain a solvent. The solvent is preferably one that can dissolve the acrylate-based polymerizable monomer and can easily volatilize. Examples of such solvents include water; alcohols such as methanol, ethanol, propanol, butanol, isopropanol, diacetone alcohol, furfuryl alcohol, tetrahydrofurfuryl alcohol, ethylene glycol, hexanediol, and propylene glycol; methyl acetate Esters, ethyl acetate and other esters; diethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol Alcohol monoethyl ether, propylene glycol monomethyl ether, tetrahydrofuran and other ethers; acetone, methyl ethyl ketone, methyl isobutyl ketone, acetone acetone, acetyl acetate, cyclohexanone and other ketones; Cellulose such as Cellulose, Ethyl Cellulose, Ding Cellulose, etc.; Aromatic compounds such as toluene and xylene; Isophorone, etc. In addition, a solvent may be used individually by 1 type, and may be used in combination of 2 or more types in arbitrary ratios.

Among the aforementioned solvents, hydrophilic solvents are preferred. By using a hydrophilic solvent, whitening due to absorption of moisture in the air can be suppressed when the antistatic agent is applied. Specifically, a mixed solvent of ethanol, methanol, and isopropanol (IPA) is preferable.

Furthermore, among the aforementioned solvents, diacetone alcohol, cyclohexanone, and acetone acetone are preferable because the surface flatness of the film of the antistatic agent is improved after coating.

Furthermore, when the metal oxide particles are prepared in the state of a dispersion liquid containing water, it is preferable to use a solvent having water solubility as a solvent of the antistatic agent.

The amount of the solvent is preferably set so that the solid content concentration of the antistatic agent is within a desired range. Here, the solid content concentration of the antistatic agent is preferably 10 wt % or more, preferably 20 wt % or more, especially 30 wt % or more, and preferably 70 wt % or less, preferably 55 wt % or less is better. By constricting the concentration of the solid content in the antistatic agent within the aforementioned range, the thickness of the antistatic layer can be easily controlled within an appropriate range, and an antistatic layer having sufficient antistatic performance can be easily produced. Furthermore, since the haze of the antistatic layer can generally be reduced, the transparency of the antistatic film can be improved. In addition, cracking of the antistatic layer and warpage of the base film can generally be suppressed. Furthermore, since the viscosity of the antistatic agent can be lowered, the coatability of the antistatic agent can be improved. Therefore, the flatness of the surface of the antistatic layer can be improved and the occurrence of uneven streaks can be suppressed.

In addition, the antistatic agent may contain arbitrary components contained in the antistatic layer.

The antistatic agent is obtained by mixing each component contained in the antistatic agent with a suitable mixing device. As a mixing apparatus, a homomixer etc. are mentioned, for example.

After preparing the antistatic agent, it is preferable to coat the antistatic agent on the base film to form a film of the antistatic agent on the base film. Furthermore, after removing the solvent from the film of the antistatic agent by drying as required, it is preferable to polymerize the acrylate-based polymerizable monomer by irradiating active energy rays such as ultraviolet rays to cure the film of the antistatic agent to obtain an antistatic layer. .

As a coating method, a bar coating method, a slit coating method, a spin coating method, a roll coating method, a curtain coating method, a screen printing method, etc. are mentioned, for example.

[6. Polarizing plate]

The antistatic film of the present invention can be used as a polarizer in combination with a polarizer.

The polarizing plate of the present invention includes a polarizer and an antistatic film disposed on at least one side of the polarizer.

As a polarizer, a film that allows one of the two linearly polarized lights intersecting at right angles to penetrate and absorb or reflect the other is used. Specific examples of polarizers include applying dichromatic iodine and dichroic dyes to films of vinyl alcohol-based polymers such as polyvinyl alcohol and partially formaldehyde polyvinyl alcohol in an appropriate order and manner. Appropriate treatment such as dyeing treatment, extension treatment, and cross-linking treatment of sexual substances. In particular, a polarizer containing polyvinyl alcohol is preferable. In addition, the thickness of the polarizer is usually 5 μm to 80 μm.

In the polarizer, when the base film of the antistatic film is a 1/4 wavelength plate, with respect to the transmission axis of the polarizer, the retardation axis of the base film of the antistatic film becomes a specified angle θ. Configuration is good. The aforementioned angle θ, specifically, is preferably above 40°, preferably above 43°, preferably below 50°, preferably below 48°, especially within the range of 45°±1° The angle is good. With this configuration, since the polarized light that penetrates the liquid crystal cell and the polarizer and advances through the antistatic film can be converted into circularly polarized light or elliptically polarized light, even when the user of the liquid crystal display device wears polarized sunglasses, It is also possible to make the displayed content identifiable.

The polarizer can be manufactured by attaching an antistatic film to one side of the polarizer.

During lamination, adhesive can also be used as required. When a polarizer and an antistatic film are bonded together to obtain a polarizing plate, the polarizer, the base film, and the antistatic layer are usually bonded together in this order.

As the adhesive, any adhesive can be used, and for example, rubber-based, fluorine-based, acrylic-based, polyvinyl-alcohol-based, polyurethane-based, polysiloxane-based, polyester-based, polyamide-based, and polyether-based can be used. adhesive, epoxy adhesive, etc. In addition, these adhesives may be used individually by 1 type, and may be used in combination of 2 or more types in arbitrary ratios. Among them, between the polarizer and the antistatic film, it is preferable to set an ultraviolet curing adhesive layer such as an acrylic adhesive layer, and attach the polarizer and the antistatic film through the ultraviolet curing adhesive layer. combine. Thereby, since the influence of moisture on the polarizer can be reduced, deterioration of the polarizer can be suppressed. In this case, the film thickness of the adhesive layer is preferably 0.1 μm or more and 2.0 μm or less.

The polarizing plate may be combined with the above-mentioned polarizer and antistatic film, and may further include an arbitrary layer. For example, the polarizer may be provided with any protective film (polarizer protective film) other than the antistatic film for the protection of the polarizer. Such a protective film is usually provided on the surface of the polarizer on the opposite side to the antistatic film.

As an arbitrary protective film, an optically isotropic isotropic film can be used, and a retardation film having a desired retardation can also be used. In the case of using a retardation film as any protective film, the retardation film can exert an optical compensation function to improve viewing angle dependence, and compensate for the light leakage phenomenon of the polarizer during squint to improve the viewing angle characteristics of the liquid crystal display device. As such a retardation film, for example, a longitudinally uniaxially stretched film, a laterally uniaxially stretched film, a longitudinally and laterally biaxially stretched film, a retardation film obtained by polymerizing a liquid crystal compound, etc. can be used. Specific examples of the retardation film include uniaxially or biaxially stretched thermoplastic resin films made of thermoplastic resins such as resins containing polymers having an alicyclic structure such as noralkene-based polymers. In addition, examples of commercially available thermoplastic resin films include "ZeonorFilm" manufactured by ZEON Corporation, "Escena" and "SCA40" manufactured by Sekisui Chemical Industry Co., Ltd., and "ArtonFilm" manufactured by JSR Corporation.

[7. Touch panel]

The antistatic film of the present invention can be used as a touch panel in combination with a touch panel component. As the combined touch panel components, any form may be used.

A touch panel component is a sensor component installed on a display device so that data can be input by a user touching a designated position while referring to an image displayed on the display surface of the display device as required. As the form of touch panel components, there are: an external type in which patterned electrodes are provided on a substrate such as glass or film to be separated from the liquid crystal cell, and an internal type in which the patterned electrodes are integrated inside the liquid crystal cell. An in-cell type, an out-cell type in which a patterned electrode is integrated outside a liquid crystal cell, etc., can be used for any of these.

The touch panel must be made to include polarizers.

In addition, a polarizing plate including the antistatic film of the present invention and a polarizer and a touch panel member may be combined to form a touch panel including a polarizing plate.

[8. Liquid crystal display device]

The antistatic film of the present invention can be used in a liquid crystal display device.

The antistatic film of the present invention is preferably installed in an image display device having a touch panel member. In addition, it is preferable that the liquid crystal display device is provided with a touch panel including the antistatic film of the present invention. A liquid crystal display device equipped with a touch panel equipped with the antistatic film of the present invention generally includes a liquid crystal cell, a polarizer disposed on the viewing side of the liquid crystal cell, and an antistatic film disposed on the viewing side of the polarizer, and more Equipped with touch panel parts. At this time, the position where the touch panel member is mounted varies depending on the configuration of the liquid crystal display device. From the viewing side (the side where the user views the image), (1) touch panel member / antistatic film / Polarizer/Liquid Crystal Cell, (2) Antistatic Film/Touch Panel Parts/Polarizer/Liquid Crystal Cell, (3) Antistatic Film/Polarizer/Touch Panel Parts/Liquid Crystal Cell, (4) Antistatic Film/polarizer/liquid crystal cell with in-cell touch panel components, (5) antistatic film/polarizer/liquid crystal cell with in-cell touch panel components, etc. In the above configuration, the antistatic film can be used in a state of a polarizer, a touch panel component or pre-integrated with a liquid crystal cell, or an adhesive can be used to attach the antistatic film to the surface of a liquid crystal display device with a touch panel component. Type use. Among them, especially (5) the composition of the antistatic film/polarizer/liquid crystal cell with in-cell touch panel components is easily affected by the degradation of the display quality of the liquid crystal cell caused by the charging through the touch panel, And it is the structure which can best exert the function of the antistatic film of the present invention. Therefore, the liquid crystal display device including the antistatic film of the present invention preferably has the configuration of (5) above.

Since the antistatic film of the present invention is excellent in light resistance, the liquid crystal display device can stabilize the driving control of the liquid crystal molecules of the liquid crystal cell. In addition, especially when the base film of the antistatic film is made of a thermoplastic resin containing a polymer containing an alicyclic structure, heat resistance and moisture resistance can be improved. A water-based adhesive is used, so it is possible to suppress the deterioration of the quality of the durability test under high temperature and high humidity. Furthermore, in the case where the base film of the antistatic film contains an ultraviolet absorber, the liquid crystal cells and polarizers can be protected from ultraviolet rays exposed to sunlight during the manufacture of the liquid crystal display device and ultraviolet rays exposed to external light when the liquid crystal display device is used. constituent parts.

As the liquid crystal display device, any of a TN type, a VA type, and an IPS type can be used. Among them, the IPS type liquid crystal display device is preferable because the display color of the liquid crystal display does not change when the viewing angle changes. In addition, when the liquid crystal display device is used as a touch panel sensor, in order to reduce the thickness of the entire liquid crystal display device, an in-cell type liquid crystal cell may be used.

In the liquid crystal display device, the liquid crystal cell and the antistatic layer of the antistatic film are preferably connected to each other. Thereby, since the electric charge stored in the liquid crystal cell can be dissipated to the antistatic layer and the charging of the liquid crystal cell can be suppressed, the driving control of the liquid crystal molecules of the liquid crystal cell can be effectively stabilized.

In a liquid crystal display device, the antistatic film is usually arranged such that the substrate film is closer to the orientation of the liquid crystal cell than the antistatic layer.

The components of the liquid crystal display device, such as liquid crystal cells, touch panel components, polarizer protective films, polarizers and antistatic films, can also be laminated and integrated. For example, a polarizer protective film, a polarizer and an antistatic film can also be laminated together to form a single polarizer. In addition, the polarizing plate and the liquid crystal cell may be bonded together, and the polarizing plate may be fixed to the liquid crystal cell. In this case, the aforementioned constituent members may be bonded through an appropriate adhesive layer, or may be directly bonded by methods such as plasma treatment on the surface of the member.

As the adhesive used for the above-mentioned adhesive layer, any of the above-mentioned adhesives can be used.

"Example"

The following examples are disclosed to specifically illustrate the present invention. However, the present invention is not limited to the embodiments disclosed below, and can be implemented with arbitrary changes without departing from the scope of the patent application of the present invention and the scope of its equivalents. In the following descriptions, unless otherwise specified, "%" and "parts" indicating parts are based on weight. And, unless otherwise noted, the operations described below are carried out under the conditions of normal temperature and normal pressure.

[Evaluation method]

(Measuring method of average number of linkages of metal oxide particles)

Photographs of chain-like linkages of metal oxide particles were taken with a transmission electron microscope. From this photograph, with respect to 100 chain links of metal oxide particles, the number of links in each chain link body was obtained, the average value was calculated, and the number of metal oxide particles was rounded off to the first decimal place to obtain the Average number of links.

(Measurement method of thickness of substrate film)

The thickness of the base film was measured with a contact thickness gauge (“Dial gauge” manufactured by Mitutoyo Corporation).

(Measuring method of light transmittance at the measurement wavelength of 380nm for the base film)

The light transmittance at the measurement wavelength of 380 nm of the base film was measured with a spectrophotometer (“V-7200” manufactured by JASCO Corporation).

(Measurement method of residual double bond ratio of antistatic layer)

The residual double bond ratio of the antistatic layer was calculated as follows.

The infrared absorption spectrum of the antistatic layer was measured by ATR method.

Specifically, with an ATR measuring device (model name "Spectrum Spotlight 300", manufactured by Perkinelmer), under the condition of one reflection using ZeSe as a fluoride, the amount of the antistatic layer exposed on the surface of the antistatic film was measured. Infrared absorption spectroscopy. Since as A _{C -} peak appears in the vicinity of the area of the 810cm ^-1 _H (a1) and as A _{C = O} peak appears in the vicinity of the area of 1720cm ^-1 (a2) calculating a1 / a2 as A _{C - H} / A _{C =} the value of _O.

Calculate the weight ratio of the acrylate-based polymerizable monomer in the antistatic agent to the acrylate-based polymerizable monomer and the metal oxide particles, that is, (the blending weight of the acrylate-based polymerizable monomer)/( The value of (the blending weight of the acrylate-based polymerizable monomer) + (the blending weight of the metal oxide particles)) was taken as the value of Wa/(Wa+Wm).

A _{C - H} /A _{C = O} ×Wa/(Wa+Wm)×100 was calculated as the value of the residual double bond ratio Dre of the antistatic layer.

(Measuring method of surface resistance value of antistatic layer)

The antistatic film before the light resistance test described later was cut out into a square of 10 cm×10 cm to obtain a sample film. A fluororesin plate was placed so as to be in contact with the base film side of the sample film, and a resistivity meter ("HIRESTA-UX MCP-HT800" manufactured by Mitsubishi Chemical Analytech Co., Ltd., with probe URS) was used at 500 V, The surface resistivity of the antistatic layer side was measured under the condition of 10 seconds. The smaller the surface resistance value, the better the antistatic property.

(Measurement method of initial resistance value)

Cut the antistatic film (conductive hard coat protective film) to obtain a rectangular sample of 45mm × 50mm. The direction of the side of the rectangular sample was set to be the longitudinal direction of the elongated base film and the direction parallel to the width direction, the longitudinal direction was set to 50 mm, and the width direction was set to 45 mm.

On the base film side of the antistatic film, a 45mm x 50mm adhesive sheet (CS9621T: manufactured by Nitto Denko Co., Ltd., thickness 20 μm), a polarizing film (manufactured by SANRITZ Corporation), "HCL2-5618S"), adhesive sheet (CS9621T: manufactured by Nitto Denko Co., Ltd., thickness 20 μm), glass (thickness 0.7 mm). On the other hand, blue flat glass (thickness 0.7mm) of 45mm×45mm was bonded to the antistatic layer using an adhesive sheet (CS9621T: manufactured by Nitto Denko Corporation, thickness 20 μm). At this time, the both ends of the longitudinal direction of the antistatic layer were bonded together so that each of them had an excess of 2.5 mm. In this way, a material having (blue flat glass)/(adhesive sheet)/(antistatic layer)/(substrate film)/(adhesive sheet)/(polarizing film)/(adhesive sheet)/(blue flat glass) is obtained. A stack of layers with exposed antistatic layers at the ends.

A silver paste was applied to a portion where the antistatic layer of the obtained stack was exposed, and it was dried at room temperature for 24 hours to prepare a test piece.

Connect the alligator clips in the tester to the conductive tape at both ends of the test piece, and start the measurement of the resistance value under the condition of a voltage of 250V. The measurement value at a time point of 30 seconds from the start of the measurement was set as the initial resistance value R0.

(Light fastness test)

After the measurement of the initial resistance value, ultraviolet rays were irradiated on the blue plate glass side surface of the test piece. Irradiation was performed using an automatic ultraviolet fading tester (U48AUB: manufactured by Suga Testing Machine Co., Ltd.) under the conditions of 500 W/m ² and a black panel temperature of 63°C. The largest resistance value among the resistance values at the time of 96 hours, the time of 192 hours, and the time of 288 hours after the start of irradiation was set as the maximum resistance value R1, and the value of R1/R0 was obtained as the resistance value rate of change. Light fastness was evaluated based on this value. The smaller the resistance value change rate, the better the light resistance.

(Measurement method of haze value of antistatic film)

The haze value of the antistatic film was measured using a haze meter (“HAZE-GARD II” manufactured by Toyo Seiki Co., Ltd.) in accordance with JIS K7136.

(Measuring method of total light transmittance of antistatic film)

The total light transmittance of the antistatic film was measured using a haze meter (“HAZE-GARD II” manufactured by Toyo Seiki Co., Ltd.) in accordance with JIS K7361-1.

(Measurement method of thickness of antistatic layer)

The thickness of the antistatic layer was measured with an interferometric film thickness meter (“F20 film thickness measurement system” manufactured by Filmetrics).

(Measuring method of refractive index of base film and antistatic layer)

The refractive indices of the base film and the antistatic layer were measured at three wavelengths of 407 nm, 532 nm, and 633 nm with a refractive index film thickness measuring device ("Hydronium Coupler" manufactured by Metricon). When the base film is a stretched film, the refractive index from the stretching direction (ns), the refractive index in the in-plane direction perpendicular to the stretching direction (nf), and the refractive index in the thickness direction (nz) are expressed as (ns+nf+nz)/ Formula 3 calculates the average refractive index of the substrate film, and uses this average refractive index as the measured value of the refractive index of the substrate film. In addition, when the base film is a uniaxially stretched film, the refractive index (nz) in the thickness direction is calculated to be approximately equal to the refractive index (nf) in the in-plane direction perpendicular to the stretching direction. Since the antistatic layer is not aligned and has the same refractive index in any direction, the refractive index in the longitudinal direction is used as the measured value of the refractive index of the antistatic layer. Using this measured value as a reference, Cauchy fitting was performed to calculate the respective refractive indices of the base film and the antistatic layer at a wavelength of 550 nm.

[Production Example 1: Production of Metal Oxide Particles]

A mixed solution in which 130 g of potassium stannate and 30 g of potassium antimony tartrate were dissolved in 400 g of pure water was prepared.

An aqueous solution prepared by dissolving 1.0 g of amine nitrate and 12 g of 15% ammonia water in 1000 g of pure water was prepared. While stirring this aqueous solution at 60°C, the aforementioned mixed solution was added to this aqueous solution over 12 hours to perform hydrolysis. In addition, at this time, a 10% nitric acid solution was added to the aforementioned aqueous solution so as to maintain the aforementioned aqueous solution at pH 9.0. By hydrolysis, a precipitate is formed in the aqueous solution.

After filtering and washing the generated precipitate, it was dispersed in water again to prepare a dispersion liquid of the hydroxide of the antimony-doped tin oxide precursor with a solid content concentration of 20% by weight. This dispersion was spray-dried at a temperature of 100°C to obtain a powder. Antimony-doped tin oxide powder was obtained by heat-treating the obtained powder at 550° C. for 2 hours in an air environment.

60 parts of this powder were dispersed in 140 parts of potassium hydroxide aqueous solution having a concentration of 4.3% by weight to obtain an aqueous dispersion. This aqueous dispersion was pulverized with a sand mill for 3 hours while maintaining at 30°C to prepare a sol. Next, this sol was subjected to debasic treatment with an ion exchange resin until the pH became 3.0. Next, pure water was added to this sol to prepare a particle dispersion liquid containing antimony-doped tin oxide particles at a solid content concentration of 20% by weight. The pH of this particle dispersion was 3.3. And the average particle diameter of the particle|grains was 9 nm.

Next, 100 g of the particle dispersion liquid was adjusted to 25° C., _{4.0 g of tetraethoxysilane (manufactured by Tama Chemical Co., Ltd.: ethyl orthosilicate, SiO 2} concentration 28.8%) was added over 3 minutes, and the mixture was stirred for 30 minutes. Thereafter, 100 g of ethanol was added over 1 minute, the temperature was raised to 50° C. over 30 minutes, and a heat treatment was performed for 15 hours. The solid content concentration of the dispersion liquid after the heat treatment was 10%.

Next, the water and ethanol in the dispersion medium were replaced with ethanol by an ultrafiltration membrane. Thereby, the dispersion liquid containing the particle|grains of the antimony-doped tin oxide coated with silica as the metal oxide particle (P1) was obtained at a solid content concentration of 20%. The above-mentioned metal oxide particles (P1) are connected in a chain shape by agglomeration of many. At this time, the average number of connections of the metal oxide particles ( P1 ) was five.

[Production Example 2-1: Production of Antistatic Agent (A1)]

The acrylic polymerizable monomers were prepared containing dipivalerythritol hexaacrylate (hereinafter, sometimes abbreviated as "DP6A") and pentaerythritol pentaacrylate (hereinafter, sometimes abbreviated as "DP5A". ) and the composition (R1) of a UV-curable polymerizable monomer of dipivaloerythritol tetraacrylate (hereinafter, it may be abbreviated as "DP4A".) In the composition (R1) of this polymerizable monomer, the weight ratio of each component is DP6A/DP5A/DP4A=64/17/19. In addition, the solid content concentration of the polymerizable monomer composition (R1) was 100%.

Prepare 222 parts by weight of isophorone diisocyanate, neotaerythritol triacrylate (hereinafter, it may be abbreviated as "PE3A".) and neopentaerythritol tetraacrylate (hereinafter, it may be abbreviated as "PE4A".) The mixture (PE3A/PE4A=75/25 (weight ratio)) of 795 parts by weight is a polyfunctional acrylic urethane (U1) of urethane-reactive acrylate. This polyfunctional urethane acrylate (U1) is an acrylate-based polymerizable monomer. The solid content concentration of this polyfunctional urethane acrylate (U1) was 100%.

A mixed ethanol of a mixture of ethanol, n-propanol, methanol, and water was prepared. In this mixed ethanol, the weight ratio of each component was ethanol/n-propanol/methanol/water=85.5/9.6/4.9/0.2.

13.7 parts by weight of the polymerizable monomer composition (R1), 1.5 parts by weight of the polyfunctional urethane acrylate (U1), 7.3 parts by weight of methyl ethyl ketone, 7.3 parts by weight of the mixed ethanol, and acetone acetone 7.3 parts by weight and 0.86 parts by weight of a photopolymerization initiator (“IRGACURE 184” manufactured by BASF Japan Co., Ltd., solid content 100%) were thoroughly mixed to obtain a mixed solution. To this mixed solution, 21.7 parts by weight of the dispersion of the metal oxide particles (P1) (20% solid content) prepared in Production Example 1 and 0.24 parts by weight of the acrylic surfactant (100% solid content) were added, and the mixture was uniformly mixed. A liquid composition having active energy ray curability was obtained as an antistatic agent (A1). The acrylate-based polymerizable monomer of the antistatic agent (A1) (the polymerizable monomer composition (R1) and the polyfunctional urethane acrylate (U1)) relative to the acrylate-based polymerizable monomer and metal oxide The weight ratio of the particles (P1) was 0.78. In addition, the weight ratio of the metal oxide particles to the acrylate-based polymerizable monomer was 0.28 (28% by weight).

[Production Example 2-2: Production of Antistatic Agent (A2)]

10.3 parts by weight of the polymerizable monomer composition (R1) prepared in accordance with Production Example 2-1, 1.1 parts by weight of polyfunctional acrylate urethane (U1) prepared in accordance with Production Example 2-1, methyl methacrylate 7.3 parts by weight of methyl ethyl ketone, 7.3 parts by weight of mixed ethanol, 7.3 parts by weight of acetylacetone and photopolymerization initiator (“IRGACURE 184” manufactured by BASF Japan Co., Ltd., solid content 100%) 0.86 parts by weight were thoroughly mixed to obtain a mixed solution. To this mixed solution, 41.1 parts by weight of the dispersion of the metal oxide particles (P1) (20% solid content) prepared in Production Example 1 and 0.24 parts by weight of the acrylic surfactant (100% solid content) were added, and the mixture was uniformly mixed. A liquid composition having active energy ray curability was obtained as an antistatic agent (A2). The acrylate-based polymerizable monomer of the antistatic agent (A2) (the polymerizable monomer composition (R1) and the polyfunctional urethane acrylate (U1)) relative to the acrylate-based polymerizable monomer and metal oxide The weight ratio of the particles (P1) was 0.58. In addition, the weight ratio of the metal oxide particles to the acrylate-based polymerizable monomer was 0.72 (72% by weight).

[Example 1]

(1-1. Manufacture of base film)

100 parts of a dried thermoplastic resin (COP1) containing a polymer having an alicyclic structure (manufactured by ZEON Co., Ltd., glass transition temperature: 123°C) and a benzotriazole-based ultraviolet absorber ( ADEKA Corporation "LA-31") 5.5 copies. Next, this mixture was injected|thrown-in to the hopper connected to an extruder, and it supplied to a uniaxial extruder and melt-extruded, and obtained the thermoplastic resin (J1) containing an ultraviolet absorber. The amount of the ultraviolet absorber in this thermoplastic resin (J1) was 5.2% by weight.

A double-screw type uniaxial extruder with a screw diameter of 50 mm equipped with a leaf disk-shaped polymer filter with a mesh size of 3 μm (ratio of screw effective length L to screw diameter D L/D=32) was prepared. The aforementioned thermoplastic resin (J1) was put into the feed hopper charged in this uniaxial extruder. Then, this thermoplastic resin (J1) was melted, and the melted thermoplastic resin (J1) was supplied to the multi-manifold die at an outlet temperature of 280° C. of the extruder and a rotation speed of the gear pump of the extruder at 10 rpm. The arithmetic surface roughness Ra of the mold gap of this manifold mold was 0.1 μm.

On the other hand, a uniaxial extruder (L/ D = 32). The thermoplastic resin (COP1) containing a polymer having an alicyclic structure, which is the same as that used by the manufacturer of the thermoplastic resin (J1), was put into the feed hopper charged in the uniaxial extruder. Then, this thermoplastic resin (COP1) was melted, and the melted thermoplastic resin (COP1) was supplied to the multi-manifold die at an outlet temperature of 285° C. of the extruder and a rotation number of a gear pump of the extruder at 4 rpm.

The molten thermoplastic resin (COP1), the molten thermoplastic resin containing the ultraviolet absorber (J1), and the molten thermoplastic resin (COP1) were discharged from the manifold mold at 280°C, respectively, and cast until the temperature was adjusted to 150°C. °C cooling roll to obtain the film before stretching. When the resin was discharged, the amount of air gap was set to 50 mm. In addition, edge pinning is employed as a method of casting the discharged resin on the cooling roll.

The obtained pre-stretching film was sequentially provided with: a resin layer made of a thermoplastic resin (COP1) with a thickness of 15 μm, a resin layer made of a thermoplastic resin containing an ultraviolet absorber (J1) with a thickness of 40 μm, and a thermoplastic resin ( COP1) is a multilayer film with a three-layer structure of resin layers with a thickness of 15 μm. In addition, the width of the film before stretching was 1400 mm, and the total thickness was 70 μm. The pre-stretching film thus obtained was subjected to a trimming process in which both end portions in the width direction of the pre-stretching film were each cut by 50 mm, and the width was set to 1300 mm.

The pre-stretching film was stretched in an oblique direction neither parallel nor perpendicular to the longitudinal direction of the pre-stretching film under the conditions of a stretching temperature of 140° C. and a stretching speed of 20 m/min to obtain a stretched film as a base film. The obtained stretched film was sequentially provided with: a first surface layer made of a thermoplastic resin (COP1) with a thickness of 8 μm, an intermediate layer made of a thermoplastic resin (J1) containing an ultraviolet absorber with a thickness of 31 μm, and a thermoplastic resin. (COP1) is a multilayer film with a 3-layer structure of the second surface layer with a thickness of 8 μm. In addition, the width of this stretched film was 1330 mm, the thickness was 47 μm, and the slow axis formed an angle of 45° with respect to the longitudinal direction of the stretched film.

This stretched film has an in-plane retardation of 100 nm at a measurement wavelength of 550 nm, a light transmittance of 0.02% at a measurement wavelength of 380 nm, and a refractive index of 1.53.

(1-2. Manufacture of antistatic film)

Corona treatment (output 0.4kW, discharge amount 200W·min/m ² ) was applied to one side of the stretched film as the base film, and the antistatic agent (A1) was cured by using a die coater to obtain an antistatic layer. The thickness of 2.2 μm was applied to form a film of the antistatic agent (A1). The coating of the said antistatic agent (A1) was performed in the environment of 50% of relative humidity. Then, after drying the film of the antistatic agent (A1) at 60° C. for 2 minutes, ^{it was cured by irradiating light with a cumulative light amount of 564 mJ/cm 2} with a high-pressure mercury lamp to form an antistatic layer. Thereby, the elongated antistatic film provided with the base film and the antistatic layer provided on this base film is obtained.

The evaluation of the antistatic film thus obtained was carried out by the above-mentioned method. The results are disclosed in Table 1.

[Example 2]

As the antistatic agent, A2 obtained in Production Example 2-2 was used in place of A1 obtained in Production Example 2-1.

The coating thickness of the antistatic agent was changed, and the thickness of the antistatic layer obtained after curing was set to 1.51 μm.

The cumulative light amount of the light irradiated for curing the film of the antistatic agent was changed to 386 mJ/cm ² .

Except for the above points, the antistatic film was obtained by operating according to Example 1. The obtained antistatic film was evaluated by the above-mentioned method. The results are disclosed in Table 1.

[Example 3]

As the antistatic agent, A2 obtained in Production Example 2-2 was used in place of A1 obtained in Production Example 2-1.

The coating thickness of the antistatic agent was changed, and the thickness of the antistatic layer obtained after curing was set to 1.58 μm.

The cumulative light amount of the light irradiated for curing the film of the antistatic agent was changed to 593 mJ/cm ² .

Except for the above points, the antistatic film was obtained by operating according to Example 1. The obtained antistatic film was evaluated by the above-mentioned method. The results are disclosed in Table 1.

[Example 4]

As the antistatic agent, A2 obtained in Production Example 2-2 was used in place of A1 obtained in Production Example 2-1.

The coating thickness of the antistatic agent was changed, and the thickness of the antistatic layer obtained after curing was set to 1.3 μm.

The cumulative light amount of the light irradiated for curing the film of the antistatic agent was changed to 300 mJ/cm ² .

Except for the above points, the antistatic film was obtained by operating according to Example 1. The obtained antistatic film was evaluated by the above-mentioned method. The results are disclosed in Table 1.

[Comparative Example 1]

The cumulative light amount of the light irradiated for curing the film of the antistatic agent was changed to 188 mJ/cm ² .

Except for the above points, the antistatic film was obtained by operating according to Example 1. The obtained antistatic film was evaluated by the above-mentioned method. The results are disclosed in Table 2.

[Comparative Example 2]

The cumulative light amount of the light irradiated for curing the film of the antistatic agent was changed to 282 mJ/cm ² .

Except for the above points, the antistatic film was obtained by operating according to Example 1. The obtained antistatic film was evaluated by the above-mentioned method. The results are disclosed in Table 2.

[Comparative Example 3]

As the antistatic agent, A2 obtained in Production Example 2-2 was used in place of A1 obtained in Production Example 2-1.

The coating thickness of the antistatic agent was changed, and the thickness of the antistatic layer obtained after curing was set to 1.11 μm.

The cumulative light intensity of the light irradiated for curing the film of the antistatic agent was changed to 588 mJ/cm ² .

Except for the above points, the antistatic film was obtained by operating according to Example 1. The obtained antistatic film was evaluated by the above-mentioned method. The results are disclosed in Table 2.

"Table 1" Table 1

"Table 2" Table 2

From Table 1, it can be seen that the antistatic films according to Examples 1 to 4 have a low haze value and good transparency.

FIG. 2 is a graph showing the relationship between the residual double bond ratio and the resistance value change rate of the antistatic films according to Examples 1 to 4 and Comparative Examples 1 to 3. FIG.

3 is a graph showing the relationship between the residual double bond ratio and the surface resistance value of the antistatic films according to Examples 1 to 4 and Comparative Examples 1 to 3. FIG.

2 , it can be seen that the antistatic films of Examples 1 to 4 whose Dre value is more than 2.5 and less than 6.1 have a small resistance value change rate of less than 4.7, and are excellent in antistatic and light resistance. On the other hand, it was found that the antistatic films of Comparative Examples 1 and 2 having a Dre value of 6.1 or more had a large resistance value change rate of 4.7 or more, and were inferior in antistatic light resistance. In addition, according to FIG. 3 , the antistatic films of Examples 1 to 4 in which the Dre value was more than 2.5 and less than 6.1 had a surface resistance value of 7.0×10 ⁸ Ω/□ or less, and had good antistatic properties. On the other hand, the antistatic film of Comparative Example 3 with a Dre value of 2.5 or less had a resistance value change rate of 1.9, but the surface resistance value was as large as 7.1×10 ⁸ Ω/□, and the antistatic property was inferior.

From this, it was found that the antistatic films of Examples 1 to 4 had a low haze value and good transparency, and simultaneously achieved both good antistatic properties and excellent light resistance.

100‧‧‧Antistatic film110‧‧‧Substrate film120‧‧‧Antistatic layer

<FIG. 1> FIG. 1 is a cross-sectional view schematically showing an embodiment of the antistatic film of the present invention.

<FIG. 2> FIG. 2 is a graph showing the relationship between the residual double bond ratio and the resistance value change rate of the antistatic films according to the examples and the comparative examples.

<FIG. 3> FIG. 3 is a graph showing the relationship between the residual double bond ratio and the surface resistance value of the antistatic films according to the examples and the comparative examples.

100‧‧‧Antistatic film

110‧‧‧Substrate film

120‧‧‧Antistatic layer

Claims (19)

An antistatic film, which is an antistatic film used in a touch panel comprising a base film and an antistatic layer disposed on the base film, wherein the antistatic layer comprises an acrylate-based adhesive composition and a metal oxide particles, the antistatic layer satisfies the formula 2.5<Dre<6.1, and the weight ratio of the metal oxide particles in the antistatic layer to the acrylate-based adhesive composition is 27% by weight or more and 200% by weight or less, Dre lines by formula _{Dre = ((a C - H} / a C = O) × (Wa / (Wa + Wm))) of the residual double bonds of the antistatic layer of defined × 100, a _{C - H} the anti-based The infrared absorption related to the out-of-plane bending vibration of the C-H bond in the acrylate structure in the infrared absorption spectrum of the electrostatic layer, A _{C = O} is the acrylate structure in the infrared absorption spectrum of the antistatic layer. The sum of the infrared absorption related to the stretching vibration of the C=O bond and the infrared absorption related to the stretching vibration of the C=O bond originating from the C=O bond of the acrylate structure, Wa is the unit volume of the antistatic layer. Wm is the weight of the acrylate-based adhesive composition, and Wm is the weight of the metal oxide particles in the antistatic layer per unit volume. The antistatic film according to claim 1, wherein the antistatic layer has a single-layer structure, and the thickness of the antistatic layer is 0.5 μm or more and 10.0 μm or less. The antistatic film according to claim 1 or 2, wherein the surface resistance value of the antistatic layer is 1.0×10 ⁶ Ω/□ or more and 7.0×10 ⁸ Ω/□ or less. The antistatic film according to claim 1 or 2, wherein the resistance value change rate of the antistatic layer after the light resistance test through ultraviolet irradiation is 1.0 or more and less than 4.7. The antistatic film according to claim 1 or 2, wherein the absolute value of the difference in refractive index between the antistatic layer and the base film is 0.1 or less. The antistatic film according to claim 1 or 2, wherein the haze value is below 0.3%, and the total light transmittance is above 85%. The antistatic film according to claim 1 or 2, wherein the base film is a base film made of a thermoplastic resin containing a polymer containing an alicyclic structure. The antistatic film according to claim 1 or 2, wherein the base film has a first surface layer, an intermediate layer and a second surface layer in sequence, wherein the intermediate layer comprises an ultraviolet absorber, and the base film has a thickness of 10 μm or more and 60 μm or less, the light transmittance of the base film at a wavelength of 380 nm is 10% or less. The antistatic film according to claim 1 or 2, wherein the base film is an obliquely extending film. The antistatic film according to claim 9, wherein the base film satisfies the following 1 and 2, 1) the in-plane retardation at a wavelength of 550 nm is 80 to 180 nm, and 2) the retardation axis is 45° with respect to the longitudinal direction ±5°. The antistatic film according to claim 1 or 2, which is a roll-shaped film. A polarizing plate comprising the antistatic film according to any one of claims 1 to 11. A touch panel, comprising the antistatic film as described in any one of claims 1 to 11 and a touch panel component. A touch panel comprising the polarizing plate and touch panel components as described in claim 12. A liquid crystal display device comprising the antistatic film according to any one of claims 1 to 11 and a touch panel member. A liquid crystal display device comprising the polarizing plate as described in claim 12. A liquid crystal display device comprising the touch panel according to claim 13 or 14. The liquid crystal display device of any one of claims 15 to 17, wherein a liquid crystal cell of the liquid crystal display device is connected to the antistatic layer. The liquid crystal display device according to any one of claims 15 to 17, wherein the liquid crystal display device is an IPS type.

Images