WO2016021670A1 - Transparent conductor, liquid crystal display device and method for producing transparent conductor - Google Patents

Abstract

The purpose of the present invention is to provide a transparent conductor which is excellent in terms of productivity and production cost, and wherein a conductive layer is able to be easily formed with a uniform thickness. A transparent conductor according to the present invention is obtained by sequentially laminating, on at least one surface of a polished glass base, an adhesive layer, a polarizing layer and a conductive layer. The conductive layer is formed using a coating composition containing a conductive polymer, and has a surface resistivity of 10²-10⁵ Ω/□.

Description

Transparent conductor, liquid crystal display device, and method of manufacturing transparent conductor

The present invention relates to a transparent conductor, a liquid crystal display device, and a method for producing a transparent conductor.

Conventionally, a display device used for a smartphone or the like has a layer configuration in which an adhesive layer, a conductive layer, and a polarizing layer are sequentially laminated on a glass substrate. Among these, the conductive layer is formed using a material such as ITO (indium tin oxide) in order to prevent malfunction of the display device due to electromagnetic wave noise generated near the display device. In recent years, further reduction in thickness and weight of display devices has been promoted by polishing glass substrates by means such as chemical polishing and mechanical polishing.

On the other hand, scratches such as dimples may occur on the surface of the glass substrate by polishing. When an ITO layer is provided on a glass substrate with scratches such as dimples, the refractive index difference between the glass substrate and the ITO layer is large, so that the scratches are easily visible, and as a result, the display quality deteriorates. There was a thing. In general, in order to maintain the display quality at a certain level industrially, the scratched glass substrate is discarded, but there has been a problem that productivity (yield) is reduced and production cost is increased.
In addition, since the thickness of the glass substrate after polishing treatment is uneven, if an ITO layer is provided as it is, the in-plane variation in film thickness increases, which hinders further improvement in performance of display devices. It was.
Furthermore, sputtering is usually performed when an ITO layer is provided. However, since a thermal load is applied during sputtering, the base material is limited to a heat-resistant material, and manufacturing costs are high because a large apparatus is required for sputtering. There was a problem.
For such a problem, for example, an attempt has been made to make the scratches less visible by laminating a refractive index adjusting layer between a glass substrate and a transparent conductive film (for example, Patent Document 1). However, since it is necessary to provide a refractive index adjusting layer separately, there is still room for reducing the manufacturing cost.

JP 2013-114086 A

An object of this invention is to provide the transparent conductor which can form a conductive layer easily with uniform thickness, and was excellent in the point of productivity or manufacturing cost.

As a result of intensive studies to solve the above problems, the present inventors have replaced the material used for the conductive layer with a coating composition containing a conductive polymer from ITO, which has been conventionally used, and further changed the coating composition to The present invention has found that by providing the conductive layer formed on the polarizing layer instead of the glass substrate, it is possible to easily form a conductive layer having a uniform thickness and solve the problems of productivity and manufacturing cost. Was completed.

That is, the transparent conductor of the present invention is
A transparent conductor in which an adhesive layer, a polarizing layer and a conductive layer are sequentially laminated on at least one surface of a polished glass substrate,
The conductive layer is formed using a coating composition containing a conductive polymer, and has a surface resistivity of 10 ² to 10 ⁵ Ω / □.

In the transparent conductor of the present invention, the pencil hardness of the conductive layer is preferably H or higher.

In the transparent conductor of the present invention, the conductive layer preferably has a surface resistivity after holding for 1000 hours in an environment of 80 ° C. and a relative humidity of 85% that is 5 times or less of the surface resistivity before holding.

In the transparent conductor of the present invention, the coating composition preferably further contains at least one selected from the group consisting of alkoxysilane oligomers, (meth) acrylates, and melamine resins as a binder.

In the transparent conductor of the present invention, the coating composition has a boiling point of 100 ° C. or more as a conductivity improver, and has at least one sulfinyl group, at least one amide group or at least two hydroxyl groups in the molecule. It is preferable that the compound which has is further included.

In the transparent conductor of the present invention, the coating composition further includes a compound having a lactone ring substituted with two hydroxyl groups and / or a compound having two or more phenolic hydroxyl groups as a water-soluble antioxidant. It is preferable.

The liquid crystal display device of the present invention includes the transparent conductor of the present invention.

The liquid crystal display device of the present invention is preferably an IPS liquid crystal display device.

The method for producing a transparent conductor of the present invention uses (i) a coating composition containing a conductive polymer after forming an adhesive layer and a polarizing layer on at least one surface of a polished glass substrate. To further form a conductive layer, or
(Ii) A glass substrate in which a conductive layer is formed on a polarizing layer using a coating composition containing a conductive polymer, and then the surface opposite to the surface on which the conductive layer is formed is polished through an adhesive layer. It is characterized by being adhered to a material.

The coating composition of the present invention is used for forming a conductive layer in the transparent conductor of the present invention.

According to the present invention, a conductive layer can be easily formed with a uniform thickness, and a transparent conductor excellent in productivity and manufacturing cost can be obtained. In addition, by providing a conductive layer on the polarizing layer, electromagnetic wave noise is shielded, and at the same time, there is an effect of preventing dust from adhering to the polarizing layer and preventing damage to the polarizing layer during display device assembly. be able to.

<< Transparent conductor >>
The transparent conductor of the present invention is a transparent conductor in which an adhesive layer, a polarizing layer and a conductive layer are sequentially laminated on at least one surface of a polished glass substrate,
The conductive layer is formed using a coating composition containing a conductive polymer (hereinafter also simply referred to as a coating composition), and has a surface resistivity of 10 ² to 10 ⁵ Ω / □.

<Glass base material>
The material for the glass substrate is not particularly limited, and commercially available materials can be used. Examples of commercially available materials include alkali-free glass, and aluminosilicate glass and aluminoborosilicate glass are particularly preferable.

The polishing treatment of the glass substrate is not particularly limited, and means usually used in this field such as chemical polishing and mechanical polishing can be used.
Although it does not specifically limit as a method of chemical polishing, For example, the method etc. which immerse a commercially available glass base material in etching liquid, and melt | dissolve the surface by chemical reaction etc. are mentioned.
Further, the method of performing mechanical polishing simultaneously with chemical polishing is not particularly limited, and examples thereof include chemical mechanical polishing (CMP) using cerium oxide.

The arithmetic average roughness (Ra) of the surface of the glass substrate is not particularly limited, but is preferably 20 nm or less, more preferably 15 nm or less, and further preferably 10 nm or less. If the arithmetic average roughness (Ra) exceeds 20 nm, transparency may not be maintained. Although the minimum of arithmetic average roughness (Ra) is not specifically limited, For example, it is 0.7 nm. In the present invention, the arithmetic average roughness (Ra) means that measured by an atomic force microscope (AFM).

The thickness of the glass substrate after the polishing treatment is not particularly limited, but is preferably 10 to 10,000 μm, and more preferably 25 to 5000 μm. Further, the total light transmittance of the glass substrate is not particularly limited as long as it is 60% or more, but it is preferably 70% or more, and more preferably 80% or more. Although the haze of a glass base material is not specifically limited, It is preferable that it is 3% or less, and it is more preferable that it is 1% or less. In addition, although the minimum of haze is not specifically limited, For example, it is 0.01%.

<Adhesive layer>
The pressure-sensitive adhesive layer is formed using a pressure-sensitive adhesive composition containing a pressure-sensitive adhesive. It does not specifically limit as an adhesive, A conventionally well-known thing can be used, Specifically, for example, (meth) obtained by homopolymerizing or copolymerizing various (meth) acrylic acid ester monomers. Acrylic resins, ethylene / vinyl acetate copolymer resins, silicone resins such as silicone rubber having a dimethylsiloxane skeleton, polyurethane resins obtained by polyaddition of polyol and polyisocyanate, natural rubber, styrene-isoprene-styrene block Copolymer (SIS block copolymer), Styrene-butadiene-styrene block copolymer (SBS block copolymer), Styrene-ethylene / butylene-styrene block copolymer (SEBS block copolymer), Styrene-butadiene Rubber, polybutadiene, polyisoprene, polyisobuty Emissions, butyl rubber, rubber-based resins such as chloroprene rubber. Among these, (meth) acrylic resins, silicon resins, and polyurethane resins, which are particularly excellent in chemical stability, have a high degree of freedom in chemical structure design, and can easily adjust adhesive strength, are preferable. Furthermore, (meth) acrylic resin and polyurethane resin are also preferable in that they are particularly excellent in transparency.

As a method for forming the pressure-sensitive adhesive layer, a conventionally known method can be used. For example, a pressure-sensitive adhesive composition containing a pressure-sensitive adhesive is applied to a glass substrate and crosslinked or heat-dried, or crosslinked or heat-dried. And a method of transferring the adhesive layer to the glass substrate. The pressure-sensitive adhesive composition may contain a crosslinking agent in addition to the pressure-sensitive adhesive.
As a method for applying the pressure-sensitive adhesive composition, conventionally known methods can be used. Specifically, for example, a roll coating method, a gravure coating method, a reverse coating method, a roll brush method, a spray coating method, an air coating method, and the like. A knife coating method or the like can be used.

<Polarizing layer>
The polarizing layer is not particularly limited as long as it includes at least a polarizing film. For example, a polarizing plate can be used. A polarizing plate is a member used in an image display device such as a liquid crystal display device (LCD) or an electroluminescence display device (ELD), and one having a transparent protective film on one side or both sides is generally used. The structure is reinforced to prevent characteristic changes.

A conventionally known polarizing film can be used as the polarizing film. For example, a polarizing film in which a dichroic dye such as iodine is adsorbed and oriented can be used on a stretched polyvinyl alcohol-based resin film. . The polyvinyl alcohol resin can be obtained by saponifying a polyvinyl acetate resin. The thickness of the polarizing film is not particularly limited, but is generally 5 to 80 um.

As the material of the transparent protective film, those having excellent transparency, mechanical strength, thermal stability, moisture barrier property, isotropy and the like are preferable, for example, polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, diacetyl cellulose, Examples thereof include cellulose polymers such as triacetyl cellulose, acrylic polymers such as polymethyl methacrylate, styrene polymers such as polystyrene and acrylonitrile / styrene copolymer (AS resin), and polycarbonate polymers. In addition, polyethylene, polypropylene, polyolefins having a cyclo or norbornene structure, polyolefin polymers such as ethylene / propylene copolymers, vinyl chloride polymers, amide polymers such as nylon and aromatic polyamide, imide polymers, sulfone polymers , Polyether sulfone polymer, polyether ether ketone polymer, polyphenylene sulfide polymer, vinyl alcohol polymer, vinylidene chloride polymer, vinyl butyral polymer, arylate polymer, polyoxymethylene polymer, epoxy polymer, or the above Examples include polymer blends. Among these, cellulose polymers such as triacetyl cellulose are preferable from the viewpoints of polarization characteristics and durability.

In addition, when providing a transparent protective film on both surfaces of a polarizing film, the transparent protective film which consists of the same polymer material may be used by the front and back, and the transparent protective film which consists of a different polymer material etc. may be used.

The thickness of the transparent protective film is not particularly limited, but is preferably 1 to 10,000 μm, and more preferably 5 to 5000 μm. Moreover, the total light transmittance of a transparent protective film is although it does not specifically limit, It is preferable that it is 60% or more, and it is more preferable that it is 80% or more.

The method for forming the polarizing layer is not particularly limited, and examples thereof include a method in which a transparent protective film is adhered to one or both sides of the polarizing film via an adhesive or the like. As the adhesive, a pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer may be used. Besides, an isocyanate-based adhesive, a polyvinyl alcohol-based adhesive, a gelatin-based adhesive, a vinyl-based latex adhesive, a polyurethane-based adhesive, Examples include polyester adhesives and epoxy adhesives.

<Conductive layer>
The conductive layer is formed using a coating composition containing a conductive polymer and has a surface resistivity of 10 ² to 10 ⁵ Ω / □.
By forming the conductive layer using a coating composition containing a conductive polymer, adverse effects on the polarizing film that may be a concern when the ITO layer is formed by sputtering (heat load or pressure load during sputtering) The conductive layer can be formed on the polarizing layer without worrying about the deterioration of the polarizing film due to the above.

The coating composition is not particularly limited as long as it contains a conductive polymer.

(Conductive polymer)
The conductive polymer is a compound for imparting conductivity to the conductive layer. The conductive polymer is not particularly limited, and a conventionally known conductive polymer can be used. Specific examples thereof include polythiophene, polypyrrole, polyaniline, polyacetylene, polyphenylene vinylene, polynaphthalene, and derivatives thereof. Can be mentioned. These may be used alone or in combination of two or more. Among these, a conductive polymer including at least one thiophene ring in the molecule is preferable in that a molecule having high conductivity can be easily formed by including a thiophene ring in the molecule. The conductive polymer may form a complex with a dopant such as polyanion.

Of the conductive polymers containing at least one thiophene ring in the molecule, poly (3,4-disubstituted thiophene) is more preferable because it is extremely excellent in conductivity and chemical stability. Further, when the coating composition contains poly (3,4-disubstituted thiophene) or a complex of poly (3,4-disubstituted thiophene) and polyanion (dopant), it can be performed at a low temperature and in a short time. A conductive layer can be formed, and productivity is also excellent. The polyanion is a conductive polymer dopant, and the content thereof will be described later.

The poly (3,4-disubstituted thiophene) is particularly preferably poly (3,4-dialkoxythiophene) or poly (3,4-alkylenedioxythiophene). As poly (3,4-dialkoxythiophene) or poly (3,4-alkylenedioxythiophene), the following formula (I):

A polythiophene in a cationic form consisting of repeating structural units represented by
Here, R ¹ and R ² each independently represent a hydrogen atom or a C _1-4 alkyl group, or, when R ¹ and R ² are bonded, a C _1-4 alkylene group. Represents. The C _1-4 alkyl group is not particularly limited, and examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group. .
In addition, when R ¹ and R ² are bonded, the C _1-4 alkylene group is not particularly limited, and examples thereof include a methylene group, 1,2-ethylene group, 1,3-propylene group, 1, 4-butylene group, 1-methyl-1,2-ethylene group, 1-ethyl-1,2-ethylene group, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, etc. Can be mentioned. Among these, a methylene group, 1,2-ethylene group, and 1,3-propylene group are preferable, and a 1,2-ethylene group is more preferable. In the C _1-4 alkyl group and the C _1-4 alkylene group, a part of hydrogen may be substituted. As the polythiophene having a C _1-4 alkylene group, poly (3,4-ethylenedioxythiophene) is particularly preferable.

The weight average molecular weight of the conductive polymer is not particularly limited, but is preferably 500 to 100,000, more preferably 1,000 to 50,000, and most preferably 1500 to 20,000. When the weight average molecular weight is less than 500, the viscosity required for the coating composition cannot be ensured, and the conductivity of the conductive layer for the transparent conductor may be lowered.

The dopant is not particularly limited, but a polyanion is preferable. The polyanion forms a complex by forming an ion pair with the polythiophene (derivative), and the polythiophene (derivative) can be stably dispersed in water. Although it does not specifically limit as a poly anion, For example, carboxylic acid polymers (for example, polyacrylic acid, polymaleic acid, polymethacrylic acid, etc.), sulfonic acid polymers (for example, polystyrene sulfonic acid, polyvinyl sulfonic acid, polyisoprene) Sulfonic acid etc.). These carboxylic acid polymers and sulfonic acid polymers are also copolymers of vinyl carboxylic acids and vinyl sulfonic acids with other polymerizable monomers such as aromatic vinyl compounds such as acrylates, styrene, vinyl naphthalene, etc. It may be. Among these, polystyrene sulfonic acid is particularly preferable.

The polystyrene sulfonic acid preferably has a weight average molecular weight of 20,000 to 500,000, and more preferably 40,000 to 200,000. If polystyrene sulfonic acid having a molecular weight outside this range is used, the dispersion stability of the polythiophene-based conductive polymer in water may decrease. The weight average molecular weight is a value measured by gel permeation chromatography (GPC).

The composite of the conductive polymer and the polyanion is preferably a composite of poly (3,4-ethylenedioxythiophene) and polystyrene sulfonic acid because it is particularly excellent in transparency and conductivity. .

The conductivity of the conductive polymer is not particularly limited, but is preferably 0.01 S / cm or more and 0.05 S / cm or more from the viewpoint of imparting sufficient conductivity to the conductive layer. More preferred.

The content of the conductive polymer in the coating composition is not particularly limited, but is preferably 0.01 to 50.0 mg / m ² when the conductive layer is formed, and preferably 0.1 to 10.0 mg / m ^2. Is more preferred. Is less than 0.01 mg / m ^2, the existing ratio of the conductive polymer in the conductive layer is reduced, the conductivity of the conductive layer may not be sufficiently secured, whereas, the 50.0 mg / m ² This is because if it exceeds, the proportion of the conductive polymer in the conductive layer increases, which may cause adverse effects on the strength and film formability of the conductive layer.

As an example of a method for producing a conductive polymer, a method for producing an aqueous dispersion of a complex of polythiophene represented by formula (I) and a dopant will be described. 3,4-dialkoxythiophene represented by the following formula (II)

(Wherein R ³ and R ⁴ each independently represent a hydrogen atom or a C _1-4 alkyl group, or, when R ³ and R ⁴ are bonded, C _1-4 alkylene) The C _1-4 alkyl group is not particularly limited, and examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group. In addition, when R ³ and R ⁴ are bonded, the C _1-4 alkylene group is not particularly limited, and examples thereof include a methylene group, 1,2-ethylene group, 1,3- Propylene group, 1,4-butylene group, 1-methyl-1,2-ethylene group, 1-ethyl-1,2-ethylene group, 1-methyl-1,3-propylene group, 2-methyl-1,3 -Propylene groups, etc. Among these, , Methylene group, 1,2-ethylene, 1,3-propylene group are preferred, 1,2-ethylene group is more preferred alkyl groups _{.C 1-4,} and _an alkylene group of _{C 1-4,} the A part of hydrogen may be substituted.) Is produced through a step of oxidative polymerization in an aqueous solvent using an oxidizing agent in the presence of a dopant.

In the production of polythiophene, a monomer is oxidatively polymerized by a chemical polymerization method using various oxidizing agents. Since the chemical polymerization method is simple and capable of mass production, it is a method suitable for an industrial production method as compared with the conventional electrolytic polymerization method.

Although it does not specifically limit as an oxidizing agent used for a chemical polymerization method, For example, the oxidizing agent which uses a sulfonic acid compound as an anion, and makes an expensive transition metal a cation etc. is mentioned. Examples of the expensive transition metal ions constituting this oxidant include Cu ²⁺ , Fe ³⁺ , Al ³⁺ , Ce ⁴⁺ , W ⁶⁺ , Mo ⁶⁺ , Cr ⁶⁺ , Mn ⁷⁺ and Sn ⁴⁺ . Among these, Fe ³⁺ and Cu ²⁺ are preferable. Specific examples of the oxidizing agent having a transition metal as a cation include FeCl ₃ , Fe (ClO ₄ ) ₃ , K ₂ CrO ₇ , alkali perborate, potassium permanganate, copper tetrafluoroborate and the like. It is done. Examples of the oxidizing agent other than the oxidizing agent having a transition metal as a cation include alkali persulfate, ammonium persulfate, and H ₂ O ₂ . Furthermore, hypervalent compounds represented by hypervalent iodine reactants can be mentioned. These may be used alone or in combination of two or more.

The amount of dopant such as polyanion used is preferably 50 to 2000 parts by weight and more preferably 100 to 1000 parts by weight with respect to 100 parts by weight of 3,4-dialkoxythiophene.

In the transparent conductor of the present invention, in order to impart sufficient electromagnetic wave noise shielding performance to the conductive layer, it is preferable to use a conductive polymer that has a low surface resistivity when formed into a conductive layer. A conductive polymer capable of achieving a low surface resistivity can be produced by, for example, a method described in Japanese Patent No. 4077675.

The coating composition may optionally contain other components in addition to the conductive polymer as long as the object of the present invention is not impaired. Examples of other components include, but are not limited to, binders, conductivity improvers, metal nanowires, solvents, crosslinking agents, catalysts, surfactants and / or leveling agents, water-soluble antioxidants, antifoaming agents, rheology A control agent, a thickener, a neutralizing agent, etc. are mentioned.

(binder)
By mix | blending a binder with a coating composition, the compound in a coating composition can be couple | bonded and a conductive layer can be formed more reliably. Although it does not specifically limit as a binder, For example, a polyester-type resin, a polyacrylic acid-type resin, a polyurethane, an epoxy resin, an acrylic resin, an alkoxysilane oligomer, a polyolefin-type resin, (meth) acrylate, a melamine resin etc. are mentioned. These may be used alone or in combination of two or more.

The polyester-based resin is not particularly limited as long as it is a polymer compound obtained by polycondensation of a compound having two or more carboxyl groups in the molecule and a compound having two or more hydroxyl groups. Examples thereof include polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate. These may be used alone or in combination of two or more.

The polyacrylic acid resin is not particularly limited, and examples thereof include polyacrylic acid and sodium polyacrylate. These may be used alone or in combination of two or more.

The polyurethane is not particularly limited as long as it is a polymer compound obtained by copolymerizing an isocyanate group-containing compound and a hydroxyl group-containing compound. For example, ester / ether polyurethane, ether polyurethane, polyester polyurethane , Carbonate polyurethane, acrylic polyurethane and the like. These may be used alone or in combination of two or more.

The epoxy resin is not particularly limited. For example, a bisphenol A type, a bisphenol F type, a phenol novolak type, a tetrakis (hydroxyphenyl) ethane type or a tris (hydroxyphenyl) methane type which is a polyfunctional type having a large number of benzene rings. , Biphenyl type, triphenolmethane type, naphthalene type, orthonovolak type, dicyclopentadiene type, aminophenol type, alicyclic epoxy resin, silicone epoxy resin and the like. These may be used alone or in combination of two or more.

The acrylic resin is not particularly limited, and examples thereof include (meth) acrylic resins and vinyl ester resins. The acrylic resin may be a polymer containing a polymerizable monomer having an acid group such as a carboxyl group, an acid anhydride group, a sulfonic acid group, and a phosphoric acid group as a constituent monomer. Or a copolymer of a polymerizable monomer having an acid group and a copolymerizable monomer. These may be used alone or in combination of two or more.

The (meth) acrylic resin may be polymerized with a copolymerizable monomer as long as it contains a (meth) acrylic monomer as a main constituent monomer (for example, 50 mol% or more). It is sufficient that at least one of the (meth) acrylic monomer and the copolymerizable monomer has an acid group. Examples of the (meth) acrylic resin include an acid group-containing (meth) acrylic monomer [(meth) acrylic acid, sulfoalkyl (meth) acrylate, sulfonic acid group-containing (meth) acrylamide, etc.] or a combination thereof. Polymer, (meth) acrylic monomer optionally having acid group, and other polymerizable monomer having acid group [other polymerizable carboxylic acid, polymerizable polyvalent carboxylic acid or anhydride Vinyl aromatic sulfonic acid, etc.] and / or copolymerizable monomers [for example, (meth) acrylic acid alkyl ester, glycidyl (meth) acrylate, (meth) acrylonitrile, aromatic vinyl monomer, etc.] Polymer, other polymer monomer having an acid group and (meth) acrylic copolymerizable monomer [for example, (meth) acrylic acid alkyl ester, hydroxyalkyl (meth) acrylate, Rishijiru (meth) acrylate, copolymers of (meth) acrylonitrile, etc.], rosin-modified urethane acrylate, special modified acrylic resins, urethane acrylates, epoxy acrylates, and urethane acrylates emulsion and the like.

Among these (meth) acrylic resins, (meth) acrylic acid- (meth) acrylic acid ester polymers (acrylic acid-methyl methacrylate copolymer, etc.), (meth) acrylic acid- (meth) acrylic acid An ester-styrene copolymer (such as acrylic acid-methyl methacrylate-styrene copolymer) is preferred.

The alkoxysilane oligomer is, for example, a high molecular weight alkoxysilane formed by condensation of alkoxysilane monomers represented by the following formula (III), and has a siloxane bond (Si—O—Si). Examples include oligomers having one or more in one molecule.
SiR ₄ (III)
(In the formula, R is hydrogen, a hydroxyl group, an alkoxy group having 1 to 4 carbon atoms, an alkyl group which may have a substituent, or a phenyl group which may have a substituent. At least one of R is an alkoxy group having 1 to 4 carbon atoms or a hydroxyl group)

The structure of the alkoxysilane oligomer is not particularly limited, and may be linear or branched. Moreover, as an alkoxysilane oligomer, the compound represented by Formula (III) may be used independently, and 2 or more types may be used together. The weight average molecular weight of the alkoxysilane oligomer is not particularly limited, but is preferably more than 152 and 4000 or less, and more preferably 500 to 2500. Here, the weight average molecular weight is a value measured by gel permeation chromatography (GPC).

The polyolefin resin is not particularly limited, and examples thereof include chlorinated polypropylene, non-chlorinated polypropylene, chlorinated polyethylene, and non-chlorinated polyethylene. These may be used alone or in combination of two or more.

Although it does not specifically limit as (meth) acrylate, For example, polyfunctional (meth) acrylate, urethane (meth) acrylate resin, etc. are mentioned. Examples of the polyfunctional (meth) acrylate include epoxy (meth) acrylate resin, bifunctional or higher polyester (meth) acrylate, polyether (meth) acrylate, carboxyl-modified reactive poly (meth) acrylate, and the like. Examples of the urethane (meth) acrylate resin include compounds obtained by reacting a hydroxy group-containing (meth) acrylate and a polyisocyanate. Examples of the hydroxy group-containing (meth) acrylate include 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, hydroxyhexyl (meth) acrylate, pentaerythritol triacrylate, diester Examples include pentaerythritol pentaacrylate and trimethylolpropane diacrylate. These may be used alone or in combination of two or more.

Although it does not specifically limit as a melamine resin, For example, the compound represented by the following general formula (IV) is mentioned.

In the formula, R ⁵ to R ¹⁰ are represented by H or CH ₂ OR ¹¹ , and R ¹¹ represents H or a C _1-4 alkyl group.

The melamine resin in which all the substituents R ⁵ to R ¹⁰ are hydrogen atoms is an imino melamine resin, the melamine resin in which all the substituents R ⁵ to R ¹⁰ are CH ₂ OH is a methylol melamine resin, and the substituent R A melamine resin having a structure in which ⁵ to R ¹⁰ are all CH ₂ OR ¹¹ and R ¹¹ is substituted with a C _1-4 alkyl group is a full ether type melamine resin. Melamine resins having a structure in which two of the three substituents are mixed in one molecule are classified as iminomethylol type, methylol ether type or imino ether type, and the melamine resin in which all are mixed is the iminomethylol ether type. . When R ⁵ to R ¹⁰ are represented by CH ₂ OR ¹¹ and R ¹¹ is a C _1-4 alkyl group, _examples of the C _1-4 alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group. There are groups. The melamine resin may be an oligomer self-condensed with formula (III) as a basic skeleton. These melamine resins may be used alone or in combination of two or more.

The coating composition preferably contains at least one selected from the group consisting of alkoxysilane oligomers, (meth) acrylates, and melamine resins as a binder. The reason is that since these binders form a dense structure in the conductive layer, sufficient pencil hardness and heat-and-moisture resistance can be ensured.

The transparent conductor of the present invention is characterized in that the conductive layer is provided on the polarizing layer. However, since the conductive layer is arranged farthest from the glass base material, compared with the conventional layer configuration, It will be placed in an environment that is susceptible to external influences such as moisture, oxygen, and ultraviolet rays in the atmosphere. In the transparent conductor of the present invention, a conductive polymer is used as the conductive component of the conductive layer. However, since the conductive polymer is an organic compound, resistance to environmental factors such as heat, atmospheric moisture, oxygen, and ultraviolet rays is particularly low. Normally, the conductivity of the conductive layer deteriorates with time due to these environmental factors. In the transparent conductor of the present invention, in the coating composition for forming the conductive layer, a binder, particularly at least one binder selected from the group consisting of alkoxysilane oligomers, (meth) acrylates and melamine resins, is used. As a result of providing a dense cross-linked structure (cross-linked network) in the coating film (conductive layer) by using in combination with molecules, while exhibiting sufficient pencil hardness that can withstand physical stimulation from the outside, As a result of the above-described dense cross-linking structure protecting the conductive polymer from attack by environmental factors, it is possible to maintain a level of conductivity that can withstand use in various applications even after a certain period of time.

When the coating composition contains a binder, the content is not particularly limited, but is preferably 80% by weight or less, more preferably 60% by weight or less in the coating composition. When the content exceeds 80% by weight, the dispersibility is deteriorated, the viscosity becomes too high, and the applicability of the coating composition may be lowered.

(Conductivity improver)
By adding a conductivity improver to the coating composition, the conductivity of the conductive layer formed using the coating composition can be improved. In addition, when using a conductivity improver, compared to the case without using a conductivity improver, the amount of the conductive polymer can be reduced while maintaining the surface resistivity. As a result, there is an advantage that transparency can be improved. is there.
In the transparent conductor of the present invention, in order to obtain sufficient electromagnetic wave noise shielding performance in the conductive layer, it is preferable to add a conductivity improver to the coating composition.

Various conductivity improvers are known, but the coating composition for forming a conductive layer in the transparent conductor of the present invention has a boiling point of 100 ° C. or higher as a conductivity improver, It is preferable to include a compound having at least one sulfinyl group, at least one amide group or at least two hydroxyl groups.

The compound having a boiling point of 100 ° C. or more and having at least one sulfinyl group, at least one amide group or at least two hydroxyl groups in the molecule is not particularly limited, and examples thereof include the following compounds:
A compound having a boiling point of 100 ° C. or higher and having at least one sulfinyl group in the molecule;
A compound having a boiling point of 100 ° C. or higher and having at least one amide group in the molecule;
A compound having a boiling point of 100 ° C. or higher and having at least two hydroxyl groups in the molecule;
A compound having a boiling point of 100 ° C. or higher and having at least one sulfinyl group and at least one amide group in the molecule;
A compound having a boiling point of 100 ° C. or higher and having at least one sulfinyl group and at least two hydroxyl groups in the molecule;
A compound having a boiling point of 100 ° C. or higher and having at least one amide group and at least two hydroxyl groups in the molecule; and a boiling point of 100 ° C. or higher and having at least one sulfinyl in the molecule A compound having a group, at least one amide group, and at least two hydroxyl groups.

Examples of the compound having a boiling point of 100 ° C. or more and having at least one sulfinyl group, at least one amide group or at least two hydroxyl groups in the molecule include dimethyl sulfoxide, N, N-dimethylacetamide, N— Methylformamide, N, N-dimethylformamide, acetamide, N-ethylacetamide, N-phenyl-N-propylacetamide, benzamide, N-methylpyrrolidone, β-lactam, γ-lactam, δ-lactam, ε-caprolactam, lauro Lactam, ethylene glycol, diethylene glycol, propylene glycol, trimethylene glycol, β-thiodiglycol, triethylene glycol, tripropylene glycol, 1,4-butanediol, 1,5-pentanediol, 1 , 3-butanediol, 1,6-hexanediol, neopentyl glycol, catechol, cyclohexanediol, cyclohexanedimethanol, glycerin, erythritol, immitol, lactitol, maltitol, mannitol, sorbitol, xylitol, sucrose and the like. These may be used alone or in combination of two or more.

Of the conductive polymers, for example, polythiophene-based conductive polymers are usually often used as a complex with a dopant (for example, poly (3,4-ethylenedioxythiophene) and polystyrenesulfonic acid. Complex). In general, polythiophene-based conductive polymers are used in the form of aqueous dispersions. However, since polythiophene exhibits strong hydrophobicity, it reacts with hydrophilic solvents (water or a mixed solvent of water and organic solvents). It is said that the polythiophene molecule exists as a core-shell structure in which a polythiophene molecule is a nucleus (core) and a dopant is a shell (shell). However, even when a conductive polymer having a core-shell structure is used as it is for the conductive layer, sufficient conductivity is hardly exhibited because the polythiophene exhibiting conductivity is surrounded by the insulating dopant.

On the other hand, in general, when a conductivity improver is used, the hydrophilicity of the entire system including the conductive polymer is lowered (hydrophobicity is increased), so the repulsive action between the conductive polymer and the solvent is weakened. The core-shell structure tends to collapse. Among the conductivity improvers, the above-mentioned boiling point is 100 ° C. or higher and the compound has at least one sulfinyl group in the molecule, the boiling point is 100 ° C. or higher and the compound has at least one amide group in the molecule, and the boiling point is 100 Three of the compounds having two or more hydroxyl groups in the molecule at a temperature of ℃ or higher contribute to the stabilization of polythiophene in the solvent in addition to the reduction of the repulsive action between the conductive polymer and the solvent. Therefore, the effect of improving conductivity is particularly high. For this reason, these conductivity improvers are suitably used in applications requiring high conductivity such as a noise cut film of an IPS liquid crystal display device.

Also, usually, when the content of the conductive polymer in the coating composition is increased, the conductivity increases, while the transparency tends to decrease due to coloring, but the conductivity is improved when achieving a certain level of conductivity. By using an agent, it has an advantage that transparency can be improved while ensuring conductivity as compared with the case where the agent is not used.

When the coating composition contains a conductivity improver, the content is not particularly limited, but is preferably 0.01 to 100,000 parts by weight, preferably 0.1 to 10,000 parts by weight based on 100 parts by weight of the solid content of the conductive polymer. Part by weight is more preferred, and 1 to 5000 parts by weight is even more preferred.

(Water-soluble antioxidant)
By adding a water-soluble antioxidant to the coating composition, it is possible to improve the moisture and heat resistance of the conductive layer formed using the coating composition, and to moderate the progress of the conductive deterioration of the conductive layer over time. it can.
The water-soluble antioxidant is not particularly limited, and examples thereof include a reducing water-soluble antioxidant and a non-reducing water-soluble antioxidant. These may be used alone or in combination of two or more.

Examples of reducing water-soluble antioxidants include L-ascorbic acid, sodium L-ascorbate, potassium L-ascorbate, D (-)-isoascorbic acid (erythorbic acid), sodium erythorbate, potassium erythorbate A compound having a lactone ring substituted with two hydroxyl groups such as: maltose, lactose, cellobiose, xylose, arabinose, glucose, fructose, galactose, mannose and other monosaccharides or disaccharides (excluding sucrose); Flavonoids such as rutin, myricetin, quercetin, kaempferol, sanmerin (registered trademark) Y-AF; gallic acid, methyl gallate, propyl gallate, tannic acid, curcumin, rosmarinic acid, chlorogenic acid, hydroquinone, 3,4,5 -bird Compounds having two or more phenolic hydroxyl group such as Dorokishi benzoic acid; cysteine, glutathione, a compound having a pentaerythritol tetrakis (3-mercapto butyrate) thiol groups, such as and the like.

Non-reducing water-soluble antioxidants include, for example, oxidative degradation such as phenylimidazolesulfonic acid, phenyltriazolesulfonic acid, 2-hydroxypyrimidine, phenyl salicylate, sodium 2-hydroxy-4-methoxybenzophenone-5-sulfonate. The compound which absorbs the ultraviolet-ray which causes this is mentioned.

Among these, a compound having a lactone ring substituted with two hydroxyl groups and / or a compound having two or more phenolic hydroxyl groups are preferable. L-ascorbic acid, sodium L-ascorbate, L-ascorbic acid More preferred is at least one selected from the group consisting of potassium, D (−)-isoascorbic acid, gallic acid, methyl gallate, propyl gallate and tannic acid.

As described above, when the conductive polymer is an aqueous dispersion, the conductive polymer has a core-shell structure, resulting in a problem that sufficient conductivity is not exhibited. However, on the other hand, the core-shell structure of the conductive polymer has a polythiophene (in the case of using a complex of polythiophene and dopant as the conductive polymer) that is important for achieving conductivity, and the surrounding oxidation component ( It also plays a role in protecting against oxygen derived from the atmosphere and radicals generated by heat and ultraviolet rays. As described above, in order to obtain a high level of conductivity that can be used in applications such as a noise cut film of an IPS liquid crystal display device, the transparent conductor of the present invention has a boiling point of 100 ° C. or higher in the molecule. Conductivity such as a compound having at least one sulfinyl group, a compound having a boiling point of 100 ° C. or more and having at least one amide group in the molecule, and a compound having a boiling point of 100 ° C. or more and having two or more hydroxyl groups in the molecule An improver is preferably used. However, when the core-shell structure is relaxed by the conductivity improver, polythiophene is easily attacked by an oxidizing component, and as a result, the oxidation of the conductive polymer proceeds rapidly. In particular, in the transparent conductor of the present invention, since the conductive layer using the conductive polymer is provided on the polarizing layer, the influence of the decrease in conductivity due to the oxidizing component is significant, and no conductivity improver is used. Compared to the case, the decrease in conductivity proceeds rapidly. Therefore, in the transparent conductor of the present invention, the use of a water-soluble antioxidant is particularly effective in moderately reducing the conductivity of the conductive layer and maintaining a certain level of conductivity over a long period of time.

Furthermore, the above-mentioned compound having a lactone ring substituted with two hydroxyl groups and / or a compound having two or more phenolic hydroxyl groups are common in that they have higher acidity than other water-soluble antioxidants. Are the above-mentioned conductivity improvers (a compound having a boiling point of 100 ° C. or higher and having at least one sulfinyl group in the molecule, a compound having a boiling point of 100 ° C. or higher and having at least one amide group in the molecule, and a boiling point of 100 Compared to the case of using other water-soluble antioxidants by using in combination with a compound having two or more hydroxyl groups in the molecule at a temperature of ℃ or higher, in the solvent due to solvation or hydrogen bond formation. Since it is stabilized, it is preferable in that a stable and homogeneous antioxidant ability can be exhibited in the conductive layer.

The transparent conductor of the present invention must have high transparency and good appearance. Among water-soluble antioxidants, compounds having a lactone ring substituted with two hydroxyl groups, phenolic hydroxyl groups A compound having two or more of them is preferably used because it interacts with the polythiophene-based conductive polymer and the binder, so that it easily stays in the conductive layer and hardly deteriorates in appearance due to bleeding out.

When the coating composition contains a water-soluble antioxidant, its content is not particularly limited, but is preferably 0.001 to 500 parts by weight, preferably 0.01 to 500 parts by weight with respect to 100 parts by weight of the solid content of the conductive polymer. 300 parts by weight are more preferable, and 0.05 to 200 parts by weight are even more preferable.

(Metal nanowires)
By mix | blending metal nanowire with a coating composition, the electroconductivity of the conductive layer formed using the coating composition can be improved.

(solvent)
The solvent is not particularly limited. For example, water; alcohols such as methanol, ethanol, 2-propanol, and 1-propanol; ethylene glycols such as ethylene glycol, diethylene glycol, triethylene glycol, and tetraethylene glycol; ethylene glycol monomethyl Glycol ethers such as ether, diethylene glycol monomethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether; Glycol ether acetates such as ethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate; propylene glycol, dipropylene glycol, Such as tripropylene glycol Propylene glycols; propylene such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, propylene glycol dimethyl ether, dipropylene glycol dimethyl ether, propylene glycol diethyl ether, dipropylene glycol diethyl ether Glycol ethers; Propylene glycol ether acetates such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate; diethyl ether, diisopropyl ether Ethers such as methyl-t-butyl ether and tetrahydrofuran; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; Carbonization such as toluene, xylene (o-, m-, or p-xylene), benzene, hexane, and heptane Hydrogen: Esters such as ethyl acetate and butyl acetate: Halogens such as chloromethane (methyl chloride), dichloromethane (methylene chloride), trichloromethane (chloroform), tetrachloromethane (carbon tetrachloride), acetonitrile, water and these And a mixed solvent (hydrous organic solvent) with two or more organic solvents, and a mixed solvent of two or more organic solvents. These solvents may be used alone or in combination of two or more.

The solvent is preferably water, an organic solvent, or a mixed solvent of water and an organic solvent. When the coating composition contains water as a solvent, the content of water is not particularly limited, but is preferably 70% by weight or less, and more preferably 50% by weight or less in the coating composition. When content exceeds 70 weight%, a viscosity will fall and the applicability | paintability of a coating composition may fall.

It is preferable that the solvent does not remain in the conductive layer formed using the coating composition. In the present specification, there is no particular distinction between those in which all components of the coating composition are completely dissolved (ie, “solvent”) and those in which insoluble components are dispersed (ie, “dispersion medium”). Are described as “solvents”.

(Crosslinking agent)
By blending a crosslinking agent, the binder can be crosslinked, and the strength of the conductive layer formed using the coating composition can be further improved.
Although it does not specifically limit as a crosslinking agent, For example, crosslinking agents, such as a melamine type, a polycarbodiimide type, a polyoxazoline type, a polyepoxy type, a polyisocyanate type, a polyacrylate type, are mentioned. These crosslinking agents may be used independently and may use 2 or more types together.

When the coating composition contains a crosslinking agent, the content is not particularly limited, but is preferably 30% by weight or less, more preferably 20% by weight or less in the coating composition.

(catalyst)
When the coating composition contains a binder and a crosslinking agent, the catalyst for crosslinking the binder is not particularly limited, and examples thereof include a photopolymerization initiator and a thermal polymerization initiator. When the coating composition contains an acrylic resin as a binder, it is preferable to use a photopolymerization initiator.

(Surfactant and / or leveling agent)
By blending a surfactant and / or a leveling agent, the leveling property of the coating composition can be improved, and a uniform conductive layer can be formed by using such a coating composition.

(Thickener)
By blending a thickener in the coating composition, the viscosity and rheological properties of the coating composition can be adjusted. Although it does not specifically limit as a thickener, For example, polyacrylic acid-type resin, a cellulose ether resin, polyvinylpyrrolidone, a polyurethane, a carboxy vinyl polymer, polyvinyl alcohol etc. are mentioned. Examples of such commercially available thickeners include CARBOPOL ETD-2623 (crosslinkable polyacrylic acid, manufactured by BF Goodrich), GE-167 (N-vinylacetamide and acrylic acid copolymer, Showa Denko Co., Ltd.) Company), Jurimer (polyacrylic acid, manufactured by Nippon Pure Chemicals Co., Ltd.), polyvinylpyrrolidone K-90 (polyvinylpyrrolidone, manufactured by Nippon Shokubai Co., Ltd.), and the like. These may be used alone or in combination of two or more.

The conductive layer is formed on the polarizing layer. More specifically, the conductive layer is formed by applying a coating composition on the polarizing layer. Since the coating composition has a high affinity for the film constituting the polarizing layer, a more uniform conductive layer can be formed.
Further, since the coating composition is applied to the film, it can be produced in a roll-to-roll manner, the productivity is improved, and the display device can be easily increased in area.

A method for forming the conductive layer using the coating composition is not particularly limited, and examples thereof include a method in which the coating composition is applied on the polarizing layer, followed by heat treatment, light irradiation treatment, and the like. A method for applying the coating composition on the polarizing layer is not particularly limited, and examples thereof include a roll coating method, a bar coating method, a dip coating method, a spin coating method, a blade coating method, a curtain coating method, a spray coating method, and a doctor. A coating method or the like can be used. Among these, the spray coating method is particularly preferable.

When applying the coating composition on the polarizing layer, a layer such as a primer layer may be formed on the polarizing layer in advance, and the coating composition may be applied on the layer. Moreover, you may apply | coat a coating composition, after giving surface treatment to the surface of a polarizing layer beforehand as needed. The surface treatment is not particularly limited, and examples thereof include corona treatment, plasma treatment, itro treatment, and flame treatment.

A conductive layer can be formed on the polarizing layer by subjecting the coating composition applied on the polarizing layer to a heat treatment, a light irradiation treatment, or the like. The heat treatment is not particularly limited and may be performed by a known method. For example, the heat treatment may be performed using a blow oven, an infrared oven, a vacuum oven, or the like. In addition, when a coating composition contains a solvent, a solvent is removed by heat processing.

Although heat processing is not specifically limited, It is preferable to perform on 150 degreeC or less temperature conditions. When the temperature of the heat treatment exceeds 150 ° C., the material of the base material to be used is limited. For example, a base material made of a material generally used for a transparent electrode film such as a PET film, a polycarbonate film, or an acrylic film cannot be used. . In this invention, even if it is heat processing on 150 degreeC or less temperature conditions, it has an advantage which can obtain the transparent conductor which has sufficient transparency and electroconductivity. The temperature of the heat treatment is preferably 50 to 140 ° C, more preferably 60 to 130 ° C. The treatment time for the heat treatment is not particularly limited, but is preferably 0.1 to 60 minutes, more preferably 0.5 to 30 minutes.

The light irradiation treatment is not particularly limited, but mainly ultraviolet rays, visible light, electron beams, ionizing radiation, etc. are used. In the case of ultraviolet curing, ultraviolet rays emitted from a light source such as an ultra-high pressure mercury lamp, a high-pressure mercury lamp, a low-pressure mercury lamp, a carbon arc, a xenon arc, or a metal halide lamp can be used. Here, the irradiation amount of the energy ray source is about 50 to 5000 mJ / cm ² as an integrated exposure amount at an ultraviolet wavelength of 365 nm.

In the transparent conductor of the present invention, the pencil hardness of the conductive layer is not particularly limited, but is preferably H or more. The reason is that sufficient film resistance can be obtained when a transparent conductor is used.

In the transparent conductor of the present invention, the thickness of the conductive layer is not particularly limited, but is preferably 0.01 to 1.0 μm, and more preferably 0.05 to 0.5 μm. The reason is that transparency, pencil strength, and moist heat resistance can be maintained while having sufficient electromagnetic wave noise shielding properties.

In the transparent conductor of the present invention, the surface resistivity of the conductive layer is not particularly limited as long as it is 10 ² to 10 ⁵ Ω / □, but it is preferably 100 to 3000 Ω / □. When the surface resistivity exceeds 10 ⁵ Ω / □, the conductive layer may not exhibit sufficient electromagnetic wave noise shielding properties.

The conductive layer preferably has a surface resistivity after holding for 1000 hours in an environment of 80 ° C. and a relative humidity of 85% that is not more than 5 times the surface resistivity before holding. If the surface resistivity after holding exceeds 5 times the surface resistivity before holding, electromagnetic wave noise may not be shielded.

The transparent conductor of the present invention may have a structure in which other layers having various functions are arbitrarily laminated in addition to the glass substrate, the adhesive layer, the polarizing layer, and the conductive layer described above. Although it does not specifically limit as another layer, For example, a hard-coat layer, a glare-proof layer, a low reflection layer, etc. are mentioned. The order of stacking these other layers is not particularly limited as long as the function as the transparent conductor is not impaired.

The total light transmittance of the transparent conductor of the present invention is not particularly limited, but is preferably 50% or more, more preferably 60% or more, and further preferably 80% or more. On the other hand, the upper limit is 100%.

The haze of the transparent conductor of the present invention is not particularly limited, but is preferably 1.0% or less, more preferably 0.8% or less, and further preferably 0.5% or less. The smaller the haze is, the better. Therefore, the lower limit is not particularly limited, but is, for example, 0.1%.

The transparent conductor of the present invention is suitably used for a liquid crystal display device, particularly an IPS liquid crystal display device.

<< Liquid Crystal Display >>
The liquid crystal display device of the present invention includes the transparent conductor of the present invention. Since the liquid crystal display device of the present invention includes the transparent conductor of the present invention, the manufacturing cost and time can be suppressed, and the occurrence of problems due to charging is small.

The liquid crystal display device of the present invention is preferably an IPS liquid crystal display device. This is because the influence of electromagnetic noise on the operation of the display device, particularly the IPS liquid crystal, is significant.

<< Method for producing transparent conductor >>
The method for producing the transparent conductor of the present invention is as follows.
(I) after forming an adhesive layer and a polarizing layer on at least one surface of a polished glass substrate, further forming a conductive layer using a coating composition containing a conductive polymer, or
(Ii) A glass substrate in which a conductive layer is formed on a polarizing layer using a coating composition containing a conductive polymer, and then the surface opposite to the surface on which the conductive layer is formed is polished through an adhesive layer. It is characterized by being adhered to a material.

<Manufacturing method (i)>
In this method, an adhesive layer and a polarizing layer are formed on at least one surface of a polished glass substrate, and then a conductive layer is further formed using a coating composition containing a conductive polymer. The method for forming the adhesive layer, the method for forming the polarizing layer, and the method for forming the conductive layer using the coating composition are all as described above.

<Manufacturing method (ii)>
In this method, after forming a conductive layer using a coating composition containing a conductive polymer on a polarizing layer, a surface opposite to the surface on which the conductive layer is formed is polished through an adhesive layer. Adhere to the substrate. The method for forming the conductive layer on the polarizing layer using the coating composition is as described above. As a method of adhering the surface of the polarizing layer opposite to the surface on which the conductive layer is formed to the polished glass substrate through the adhesive layer, it is common to perform adhesion by pressing, but if necessary Heat may be applied.

According to the method for producing a transparent conductor of the present invention, the transparent conductor of the present invention can be produced easily and inexpensively with a small number of steps.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated, this invention is not limited to a following example. Hereinafter, “part” or “%” means “part by weight” or “% by weight”, respectively, unless otherwise specified.

1. Materials used 1-1. Glass substrate / glass substrate subjected to polishing treatment (produced by chemically polishing non-alkali glass (Corning, EAGLE XG) with an etching solution)

1-2. Adhesive layer (adhesive)
・ Acrylic resin (Nagase ChemteX, SG790)
(Crosslinking agent)
・ Isocyanate compound (Nihon Polyurethane, Coronate HL)

1-3. Polarizing layer (transparent protective film)
Triacetyl cellulose (TAC) film (Konica Minolta, KC8UX2MW, thickness 80 μm)
・ Cycloolefin resin (COP) film (manufactured by Nippon Zeon Co., Ltd., ZEONOR, thickness 60μm)
(Polarizing film)
・ Polyvinyl alcohol film (Nippon Gosei Co., Ltd., thickness 75μm)
(adhesive)
・ UV curable epoxy adhesive (made by ADEKA, KR series)

1-4. Conductive layer (conductive polymer)
・ PEDOT / PSS (manufactured by Heraeus, Clevios PH1000)
(binder)
・ Polyester resin (manufactured by Nagase ChemteX Corporation, Gabsen ES-210)
・ Alkoxysilane oligomer (manufactured by Fuso Chemical Industry Co., Ltd., N-POS)
・ Alkoxysilane oligomer (manufactured by Shin-Etsu Chemical Co., Ltd., KBE-402)
・ (Meth) acrylate (Daiichi Kogyo Seiyaku Co., Ltd., New Frontier R-1150D)
・ Acrylic resin (Toagosei Co., Ltd., Jurimer AT-510, solid content 30%)
・ Melamine resin (Mitsui Cyanamid Co., Ltd., Cymel 300)
(Conductivity improver)
・ Ethylene glycol (Wako Pure Chemical Industries, Ltd.)
・ Dimethyl sulfoxide (DMSO) (manufactured by Wako Pure Chemical Industries, Ltd.)
・ Acetamide ・ Dioxane ・ ε-Caprolactam (Water-soluble antioxidant)
・ Ascorbic acid (Wako Pure Chemical Industries, Ltd.)
・ Tannic acid (Wako Pure Chemical Industries, Ltd.)
・ Hydroquinone (Wako Pure Chemical Industries, Ltd.)
・ D (+)-glucose (manufactured by Wako Pure Chemical Industries, Ltd.)
(solvent)
-Industrial denatured alcohol (manufactured by Nippon Alcohol Sales Co., Ltd., Solmix AP-7)

2. Evaluation method The transparent conductors obtained in the respective Examples and Comparative Examples were evaluated as follows.

2-1. Surface resistivity (SR)
The surface resistivity of the conductive layer was measured using a resistivity meter (manufactured by Mitsubishi Chemical Corporation, Lorester GP MCP-T600).

2-2. Moisture and heat resistance test The surface resistivity immediately after the formation of the conductive layer and the surface resistivity after being kept in an environment of 80 ° C. and 85% relative humidity for 1000 hours using a thermo-hygrostat (manufactured by ESPEC, FR-1J). The measurement was made using a resistivity meter (Lorestar GP MCP-T600, manufactured by Mitsubishi Chemical Corporation), and the moisture and heat resistance was evaluated in the following seven stages.
7: Surface resistivity after holding is 1.1 times or less of surface resistivity before holding 6: Surface resistivity after holding is larger than 1.1 times of surface resistivity before holding 1.2 5 or less: The surface resistivity after holding is greater than 1.2 times the surface resistivity before holding and 1.5 times or less. 4: The surface resistivity after holding is the surface resistivity before holding. 3 to 1.5 times greater than or equal to 2.0 and less than or equal to 3: Surface resistivity after holding is greater than 2.0 times and less than or equal to 3.0 times surface resistivity before holding 2: Surface after holding Resistivity is more than 3.0 times and less than 5.0 times the surface resistivity before holding 1: The surface resistivity after holding is more than 5.0 times the surface resistivity before holding

2-3. Pencil hardness The pencil hardness of the conductive layer was measured using a pencil scratch hardness tester (manufactured by Yasuda Seiki Seisakusho Co., Ltd.) according to the test method of JIS-K5600-5-4.

2-4. In-plane variation (CV%)
In a section of the conductive layer having a width of 20 cm and a length of 20 cm, the surface resistivity was measured by the method described in 2-1, for a total of 25 points with an interval of 50 mm in the width direction and 50 mm in the length direction. An average value was obtained, and a coefficient of variation CV% representing in-plane variation was calculated by the following formula.
CV% = standard deviation σ / average surface resistivity r × 100 (%)

2-5. Electromagnetic wave noise shielding properties Electromagnetic wave noise shielding properties were measured in the frequency range of 1 to 100 MHz by the KEC method and evaluated according to the following criteria.
A: The electromagnetic wave noise shielding effect is 30 dB or more.
Δ: Electromagnetic wave noise shielding effect is 20 dB or more and less than 30 dB.
X: The electromagnetic wave noise shielding effect is less than 20 dB.

2-6. Illumination for visual inspection of the transparent conductor was placed on the back of the transparent conductor, and the appearance characteristics of the transparent conductor were evaluated in the following two stages.
○: Concavities and convexities and scratches were not confirmed.
X: Concavities and convexities and scratches were confirmed.

2-7. Adhesion (cross cut test)
According to JIS K 5400, a cross cut test was performed and evaluated according to the following criteria.
5: The result of the cross cut test is 10 points 4: The result of the cross cut test is 9 points 3: The result of the cross cut test is 8 points 2: The result of the cross cut test is 7 points 1: Cross-cut test result is 6 points or less

2-8. Weather resistance test Immediately after forming the conductive layer (initial surface resistivity) and using a xenon lamp with a weather resistance tester (manufactured by ATLAS Material Testing Technology GmbH, SUNSET CPS), an irradiance of 162 W / m ² (300 To 400 nm), a temperature resistivity of 63 ° C., and a humidity of 50%. The surface resistivity after irradiation with UV for 500 hours (surface resistivity after irradiation) was measured with a resistivity meter (Lorestar GP, manufactured by Mitsubishi Chemical Corporation). MCP-T600) and the weather resistance was evaluated according to the following 7 levels.
7: Surface resistivity after irradiation is less than 3 times the initial surface resistivity 6: Surface resistivity after irradiation is 3 times or more and less than 5 times the initial surface resistivity 5: Surface resistivity after irradiation is The initial surface resistivity is 5 times or more and less than 10 4: The surface resistivity after irradiation is 10 times or more and less than 20 times the initial surface resistivity 3: The surface resistivity after irradiation is 20 times the initial surface resistivity. The surface resistivity after irradiation is 30 times or more and less than 50 times the initial surface resistivity. 1: The surface resistivity after irradiation is 50 times or more the initial surface resistivity.

(Examples 1 to 3, 5, 6, 8 to 53)
Each component was mixed in the weight ratio described in Tables 1 to 4 to prepare an adhesive composition. Next, the obtained pressure-sensitive adhesive composition was applied to one side of a polished glass substrate with an applicator so that the film thickness after drying was 15 μm, and dried at 120 ° C. for 2 minutes. An adhesive layer was formed on top.
Next, after extending | stretching a polyvinyl alcohol film 5 times in iodine aqueous solution, it was dried at 50 degreeC for 4 minute (s), and the polarizing film was produced. A triacetyl cellulose (TAC) film as a transparent protective film was adhered to both sides of the polarizing film using an ultraviolet curable epoxy adhesive to form a polarizing layer. This polarizing layer was bonded to the aforementioned adhesive layer.
Furthermore, each component was mixed in the weight ratios described in Tables 1 to 4 to prepare a coating composition, and then applied onto the polarizing layer prepared above using a bar coater (manufactured by Yasuda Seiki Seisakusho) A conductive layer was formed by heat treatment at 100 ° C. for 1 minute using a drier (Tokyo Rika Kikai Co., Ltd., WFO-401 type) to obtain a transparent conductor.

Example 4
A transparent conductor was obtained in the same manner as in Example 1 except that a cycloolefin resin (COP) film was used instead of the TAC film.

(Example 7)
The polyvinyl alcohol film was stretched 5 times in an aqueous iodine solution and then dried at 50 ° C. for 4 minutes to produce a polarizing film. A triacetyl cellulose (TAC) film as a transparent protective film was adhered to both sides of the polarizing film using an ultraviolet curable epoxy adhesive to form a polarizing layer. Next, after mixing each component by the weight ratio described in Table 1, and producing a coating composition, it apply | coats on the polarizing layer produced above using a bar coater (made by Yasuda Seiki Seisakusyo Co., Ltd.), and blows air. A conductive layer was formed on the polarizing layer by heat treatment at 100 ° C. for 1 minute using a constant temperature dryer (manufactured by Tokyo Rika Kikai Co., Ltd., WFO-401 type).
Moreover, each component was mixed by the weight ratio described in Table 1, and after producing an adhesive composition, the obtained adhesive composition was dried with the applicator on the single side | surface of the glass substrate by which the grinding process was carried out. It apply | coated so that a film thickness might be set to 15 micrometers, and it dried for 2 minutes at 120 degreeC, and formed the adhesion layer on the glass base material.
Furthermore, the transparent conductor was obtained by bonding the polarizing layer to the glass substrate via the adhesive layer on the surface opposite to the surface on which the conductive layer was formed.

(Comparative Example 1)
An ITO layer was formed by sputtering ITO on the polished glass substrate. Moreover, each component was mixed by weight ratio described in Table 4, and an adhesive composition was produced, it apply | coated so that the film thickness after drying with an applicator might be set to 15 micrometers on an ITO layer, and 120 degreeC 2 It dried for minutes and formed the adhesion layer on the ITO layer. Next, after extending | stretching a polyvinyl alcohol film 5 times in iodine aqueous solution, it was dried at 50 degreeC for 4 minute (s), and the polarizing film was produced. A triacetyl cellulose (TAC) film as a transparent protective film was adhered to both sides of the polarizing film using an ultraviolet curable epoxy adhesive to form a polarizing layer. Furthermore, this polarizing layer was bonded to the above-mentioned adhesive layer to obtain a transparent conductor.

(Comparative Example 2)
A transparent conductor was obtained in the same manner as in Example 1 except that the coating composition obtained by mixing each component at the weight ratio shown in Table 4 was used.

(Comparative Example 3)
A coating composition obtained by mixing each component at a weight ratio shown in Table 4 on a polished glass substrate was applied using a slit coater, and a blown constant temperature dryer (manufactured by Tokyo Rika Kikai Co., Ltd.). , WFO-401 type) was heated at 100 ° C. for 1 minute to form a conductive layer. Moreover, each component was mixed by the weight ratio described in Table 4, the adhesive composition was produced, and it apply | coated so that the film thickness after drying with an applicator might be set to 15 micrometers on a conductive layer, and 120 degreeC 2 It dried for minutes and formed the adhesion layer on the conductive layer. Next, after extending | stretching a polyvinyl alcohol film 5 times in iodine aqueous solution, it was dried at 50 degreeC for 4 minute (s), and the polarizing film was produced. A triacetyl cellulose (TAC) film as a transparent protective film was adhered to both sides of the polarizing film using an ultraviolet curable epoxy adhesive to form a polarizing layer. A transparent conductor was obtained by pasting this polarizing layer on the adhesive layer described above.

Using the transparent conductors obtained in Examples 1 to 53 and Comparative Examples 1 to 3, the surface resistivity (SR) was measured by the above-described method, and the moisture resistance, pencil hardness, in-plane variation, electromagnetic wave noise were measured. The shielding property, appearance of the transparent conductor, adhesion, and weather resistance were evaluated. The results are shown in Tables 1 to 4.
For reference, the total light transmittance (without glass substrate, adhesive layer and polarizing film) is applied on the transparent protective film using a bar coater (manufactured by Yasuda Seiki Seisakusho). Tables 1 to 4 also show the results of measuring Tt) and haze using a haze computer (HGM-2B, manufactured by Suga Test Instruments Co., Ltd.) in accordance with JIS K7150.

Claims (10)

1. A transparent conductor in which an adhesive layer, a polarizing layer and a conductive layer are sequentially laminated on at least one surface of a polished glass substrate,
   The conductive layer is a transparent conductor formed using a coating composition containing a conductive polymer and having a surface resistivity of 10 ² to 10 ⁵ Ω / □.
2. The transparent conductor according to claim 1, wherein the conductive layer has a pencil hardness of H or more.
3. 3. The transparent conductor according to claim 1, wherein the conductive layer has a surface resistivity after holding for 1000 hours in an environment of 80 ° C. and a relative humidity of 85% that is 5 times or less of the surface resistivity before holding. .
4. The transparent conductor according to any one of claims 1 to 3, wherein the coating composition further comprises at least one selected from the group consisting of an alkoxysilane oligomer, a (meth) acrylate, and a melamine resin as a binder.
5. The coating composition further comprises, as a conductivity improver, a compound having a boiling point of 100 ° C. or higher and having at least one sulfinyl group, at least one amide group, or at least two hydroxyl groups in the molecule. 5. The transparent conductor according to any one of 1 to 4.
6. The coating composition further comprises a compound having a lactone ring substituted with two hydroxyl groups and / or a compound having two or more phenolic hydroxyl groups as a water-soluble antioxidant. 2. The transparent conductor according to item 1.
7. A liquid crystal display device comprising the transparent conductor according to any one of claims 1 to 6.
8. The liquid crystal display device according to claim 7, which is an IPS liquid crystal display device.
9. (I) after forming an adhesive layer and a polarizing layer on at least one surface of a polished glass substrate, further forming a conductive layer using a coating composition containing a conductive polymer, or
   (Ii) A glass substrate in which a conductive layer is formed on a polarizing layer using a coating composition containing a conductive polymer, and then the surface opposite to the surface on which the conductive layer is formed is polished through an adhesive layer. Glue to the material,
   The method for producing a transparent conductor according to any one of claims 1 to 6.
10. A coating composition for forming a conductive layer in the transparent conductor according to any one of claims 1 to 6.