JP2012220658A - Near infrared ray shielding film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a near infrared ray shielding film having sufficient antireflection performance, antistatic performances and near infrared ray absorption power, and having excellent heat resistance, etc. even without laminating a hard coat layer.SOLUTION: A low refractive index layer is directly laminated on one surface of a transparent substrate film, and a near infrared ray absorption adhesive layer is laminated on the other surface. The low refractive index layer includes (b) 40 to 250 parts by mass of hollow silica fine particles, and (c) 1 to 25 parts by mass of a composite consisting of a π conjugated conductive polymer and a dopant per (a) 100 parts by mass of a multi-functional (meth)acrylate. A mass ratio of the π conjugated conductive polymer and the dopant in (c) is 1:1 to 1:5. The near infrared ray absorption adhesive layer includes (d) a (meth)acrylic adhesive resin composition including a (meth)acrylic resin with an acid number of 20 mgKOH/g or less, and (e) a diimmonium based dye or a phthalocyanine based dye.

Description

  The present invention relates to a near-infrared shielding film that is applied to, for example, a plasma display panel (PDP) and the like, has sufficient antireflection performance and near-infrared absorption capability, and is excellent in antistatic performance.

  In an advanced information society in recent years, optoelectronic devices such as electronic displays have made remarkable progress and are widely used for monitors of televisions and personal computers. Among them, plasma display panels (hereinafter sometimes referred to as PDPs) are attracting attention as electronic display panels are becoming larger and thinner. However, peripheral devices such as remote control devices are generated by near-infrared rays generated by the operating principle. There is a problem of causing a malfunction. In recent years, electronic image display devices (electronic displays) such as a plasma display panel and a liquid crystal display panel have a problem in that the visibility of an image displayed due to the reflection of external light is reduced due to the increase in size. For this reason, a method of improving the visibility of an image by providing an antireflection layer on the near-infrared shielding film is generally employed. Furthermore, in order to prevent dust and the like from adhering to the display surface due to static electricity, these near-infrared shielding films are required to have antistatic performance.

  In order to solve these problems, a near-infrared absorption formed by applying an anti-reflection layer (low refractive index layer) used in a PDP optical filter and a near-infrared absorbing adhesive using a diimonium dye or a phthalocyanine dye. A near-infrared shielding film in which an adhesive layer is combined has been proposed (Patent Document 1).

  In order to impart antistatic properties, π-conjugated conductive polymers are used as industrial materials such as various antistatic agents and electrode materials. This π-conjugated conductive polymer is imparted with high conductivity by doping a substance called a dopant. For example, a coating agent composition containing a complex composed of a π-conjugated conductive polymer and a dopant and a polyfunctional (meth) acrylate is known (Patent Document 2).

  Further, a near-infrared shielding film having an antistatic property, in which a hard coat layer and a low refractive index layer are laminated on one side of a transparent base film and a near-infrared absorbing layer is provided on the other side, is known (patent) Reference 3).

Special table 2010-502563 JP 2008-222850 A JP 2009-31506 A

  However, since the near-infrared shielding film described in Patent Document 1 does not contain a material such as an antistatic agent for exhibiting antistatic performance, dust tends to adhere to the display surface, and dirt is conspicuous. Becomes difficult to see. In addition, in the display manufacturing process, problems may occur due to dust contamination.

  In contrast, Patent Document 2 describes a composite having antistatic properties, but such a composite comprising a π-conjugated conductive polymer and a dopant has a high refractive index of about 1.5. Therefore, conventionally, it is generally used as a material for forming a high refractive index layer, and a low refractive index layer cannot be formed as it is.

  In Patent Document 3, since the hard coat layer is formed between the transparent base film and the low refractive index layer, the number of coatings increases, and thus the productivity decreases. In addition, the near-infrared shielding film is required to have sufficient heat resistance and scratch resistance during production and use. However, if the hard coat layer is simply discarded to solve the problem of Patent Document 3, the heat resistance and scratch resistance of the near-infrared shielding film are lowered.

  Therefore, the object of the present invention is to have excellent antistatic performance while having sufficient antireflection performance, excellent near-infrared absorption capability, and heat resistance and scratch resistance even without a hard coat layer laminated. It is providing the near-infrared shielding film excellent in property and pencil hardness.

  In order to achieve the above object, the near-infrared shielding film of the first invention has a low refractive index layer directly laminated on one surface of a transparent substrate film, and absorbs near-infrared light on the other surface of the transparent substrate film. A near-infrared shielding film in which an adhesive layer is laminated, wherein the low refractive index layer comprises (a) polyfunctional (meth) acrylate, (b) hollow silica fine particles, and (c) π-conjugated conductive high And (b) 40-250 parts by mass of hollow silica fine particles per 100 parts by mass of (a) polyfunctional (meth) acrylate, and (c) π-conjugated system conductivity. 1-25 parts by mass of a complex composed of a polymer and a dopant, and the mass ratio of the π-conjugated conductive polymer and the dopant in the complex composed of (c) the π-conjugated conductive polymer and the dopant is 1: 1 to 1: 5, the near-infrared absorbing adhesive layer , (D) a (meth) acrylic adhesive resin composition, and (e) a near-infrared absorbing dye, wherein the (d) (meth) acrylic adhesive resin composition has an acid value of 0 to 20 mgKOH / g. A (meth) acrylic resin is included, and the (e) near-infrared absorbing dye is a diimonium dye or a phthalocyanine dye.

  The near-infrared shielding film of the second invention is characterized in that, in the first invention, the π-conjugated conductive polymer is a polythiophene.

  The near-infrared shielding film of the third invention is characterized in that, in the second invention, the polythiophene is poly (3,4-ethylenedioxythiophene).

  A near-infrared shielding film of a fourth invention is characterized in that, in the first invention, the π-conjugated conductive polymer is polypyrrole or polyaniline.

  The near-infrared shielding film of a fifth invention is characterized in that, in any one of the first to fourth inventions, the dopant is a polyanion.

  A near-infrared shielding film of a sixth invention is characterized in that, in the fifth invention, the polyanion is polystyrene sulfonic acid.

  According to the near-infrared shielding film of the first invention, the following effects can be exhibited. Since the low refractive index layer has an antireflection effect, when the near-infrared shielding film of the present invention is bonded to the display surface of an electronic image display device such as a plasma display panel or a liquid crystal display panel, an external light source such as a fluorescent lamp is used. The reflection of the irradiated light beam can be suppressed and the visibility of the image displayed on the display can be improved. At the same time, since the low refractive index layer contains a complex composed of a π-conjugated conductive polymer and a dopant, the near-infrared shielding film has an antistatic action, and a near-infrared shielding film stuck on the display surface. Attachment of dust and the like to the film due to static electricity can be suppressed.

  In addition, based on the nature of the cured product of (a) polyfunctional (meth) acrylate, it is possible to improve the scratch resistance and pencil hardness of the near-infrared shielding film without providing a hard coat layer. . In addition, (c) the mass ratio of the π-conjugated conductive polymer and the dopant in the complex composed of the π-conjugated conductive polymer and the dopant is set to 1: 1 to 1: 5, so that In addition to exhibiting excellent electrical conductivity, it is possible to exhibit good heat resistance. Moreover, since the near-infrared absorbing adhesive layer is laminated on the other surface of the transparent base film, it is possible to prevent malfunction of peripheral devices remotely controlled by near-infrared rays emitted from the module.

  In the near-infrared shielding film of the second invention, since the π-conjugated conductive polymer is a polythiophene, in addition to the effects of the first invention, it exhibits good conductivity with a smaller content. Can do.

  In the near-infrared shielding film of the third invention, since the polythiophene is poly (3,4-ethylenedioxythiophene), in addition to the effects of the second invention, good conductivity with a smaller content In addition, the material can be easily obtained.

  In the near-infrared shielding film of the fourth invention, since the π-conjugated conductive polymer is polypyrrole or polyaniline, in addition to the effect of the first invention, good conductivity with a smaller content is obtained. Can be expressed.

  In the near-infrared shielding film of the fifth invention, since the dopant is a polyanion, in addition to the effects of any one of the first to fourth inventions, good conductivity can be expressed with a smaller content. it can.

  In addition to the effects of the fifth invention, the near-infrared shielding film of the sixth invention can exhibit good conductivity with a smaller content and easily obtain materials since the polyanion is polystyrene sulfonic acid. Is possible.

<Transparent substrate film>
The transparent substrate film used for the near-infrared shielding film of the present invention is not particularly limited as long as it has transparency, but the refractive index (n) is in the range of 1.55 to 1.70 in order to suppress light reflection. The inside is preferable. As a material for forming such a transparent substrate film, for example, polyester such as polyethylene terephthalate (PET, n = 1.65), polycarbonate (PC, n = 1.59), polyarylate (PAR, n = 1. 60) and polyethersulfone (PES, n = 1.65) are preferred. Among these, a polyester film, particularly a polyethylene terephthalate film is preferable from the viewpoint of ease of molding.

  The thickness of the transparent substrate film is preferably 25 to 400 μm, more preferably 50 to 200 μm. In addition, various additives may be contained in the transparent base film. Examples of such additives include ultraviolet absorbers, antistatic agents, stabilizers, plasticizers, lubricants, flame retardants, and the like. Moreover, in order to improve the adhesiveness of a transparent base film and a low refractive index layer, you may provide a well-known interference prevention layer between a transparent base film and a low refractive index layer. The interference prevention layer can be formed on the surface of the transparent substrate film by a known method during the production of the transparent substrate film, or a commercially available product of a transparent substrate film on which an interference prevention layer has been formed in advance is used. You can also.

<Low refractive index layer>
The low refractive index layer comprises (a) polyfunctional (meth) acrylate, (b) hollow silica fine particles, and (c) a complex composed of a π-conjugated conductive polymer and a dopant (conductive polymer, complex). It is a cured product of the coating liquid for the low refractive index layer contained. The thickness of the low refractive index layer is preferably kλ / 4 because surface reflection is reduced by light interference and the transmittance is improved. Here, λ represents a wavelength of light of 400 to 650 nm, and k represents 1 or 3. Thus, the antireflection effect can be further enhanced by setting the thickness of the low refractive index layer to kλ / 4. In this case, when k is 1, antireflection performance (luminosity reflectance) is improved, and when k is 3, scratch resistance is improved.

  The refractive index of the low refractive index layer is preferably 1.20 to 1.44. When the refractive index is less than 1.20, the content of the polyfunctional (meth) acrylate is relatively decreased in relation to the content of the hollow silica fine particles described later, so that the low refractive index layer has sufficient coating strength. It becomes difficult to have On the other hand, when the refractive index exceeds 1.44, sufficient antireflection performance cannot be obtained.

[Multifunctional (meth) acrylate]
(a) Polyfunctional (meth) acrylate is a resin that undergoes a curing reaction when irradiated with active energy rays such as ultraviolet rays and electron beams, and the type thereof is not particularly limited. From the viewpoint of improving the strength and scratch resistance of the coating film, polyfunctional (meth) acrylate is used instead of monofunctional (meth) acrylate. Here, the monofunctional (meth) acrylate indicates a resin having one acryloyl group (CH ₂ ═CHCO—) or methacryloyl group (CH ₂ ═C (CH ₃ ) CO—) in the molecule, and is polyfunctional. (Meth) acrylate refers to a resin having two or more acryloyl groups or methacryloyl groups in the molecule.

  This polyfunctional (meth) acrylate is not particularly limited, and a known polyfunctional (meth) acrylate can be used. Moreover, in order to make the refractive index of a low refractive index layer lower, fluorine-containing polyfunctional (meth) acrylate can also be used. As the polyfunctional (meth) acrylate, for example, a bifunctional to hexafunctional acrylate is used. Specifically, 1,6-hexanediol di (meth) acrylate, triethylene glycol di (meth) acrylate, ethylene oxide-modified bisphenol A di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra ( (Meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, pentaerythritol tri (meth) acrylate, 3- (meth) acryloyloxyglycerin mono (meth) acrylate, urethane acrylate, epoxy acrylate, Although ester acrylate etc. are mentioned, it is not necessarily limited to these. These compounds may use only 1 type and may use 2 or more types together.

[Hollow silica fine particles]
(b) The hollow silica fine particles are fine particles in which silica (silicon dioxide, SiO ₂ ) is formed in a substantially spherical shape and has a hollow portion in the outer shell. The average particle diameter of the hollow silica fine particles is preferably 10 to 100 nm, more preferably 20 to 60 nm. When the average particle diameter of the hollow silica fine particles is smaller than 10 nm, it is not preferable because the production of the hollow silica fine particles becomes difficult. On the other hand, when the average particle size is larger than 100 nm, the light scattering in the low refractive index layer increases, the reflection increases in the thin film, and the antireflection function decreases. In addition, the average particle diameter in this invention is the value measured by the dynamic light scattering theory / frequency matrix analysis method (FFT method) using nanotracUPA-EX150 [The particle size distribution measuring machine by Nikkiso Co., Ltd.]. Say.

  The hollow silica fine particles are used by being dispersed in an organic solvent. The hollow silica fine particles can also be synthesized by a method for producing hollow spherical silica-based fine particles having a cavity inside the outer shell, as disclosed in, for example, JP-A-2006-21938. Based on this method, modified hollow silica fine particles (sol) are produced in Examples and Comparative Examples described later. In addition, modified hollow silica fine particles obtained by modifying the surface of the hollow silica fine particles with a silane coupling agent having a polymerizable double bond can also be used.

[Composite composed of π-conjugated conductive polymer and dopant]
(c) A complex composed of a π-conjugated conductive polymer and a dopant refers to a compound obtained by doping a π-conjugated conductive polymer with a dopant. Its refractive index is approximately 1.5. Even if a π-conjugated conductive polymer is used alone, conductivity is not exhibited, but doping with a dopant generates electrons that can move freely on the π-conjugated conductive polymer, and the conductivity is low. It will be obtained.

  The π-conjugated conductive polymer is a polymer compound having a π-conjugated structure (a structure in which double bonds are adjacent to each other with a single bond) in the molecular structure. The polymer compound here means a compound having a molecular weight of 10,000 or more. A well-known thing can be used as (pi) conjugated system conductive polymer. Of these, polythiophenes, polypyrroles or polyanilines are preferably used from the viewpoint of conductivity and stability in the external environment, and polythiophenes are particularly preferably used.

  Specific examples of polythiophenes include poly (3,4-ethylenedioxythiophene), poly (3-methylthiophene), poly (3,4-ethylenedioxythiophene), poly (3-hexyloxythiophene), poly (3-methyl-4-methoxythiophene) and the like. Specific examples of polypyrroles include poly (3-butylpyrrole) and poly (3-methyl-4-hexyloxypyrrole). Specific examples of the polyanilines include poly (2-methylaniline) and poly (3-isobutylaniline).

  The dopant (dopant) generates electrons that can move freely on the π-conjugated conductive polymer by doping (complex formation) with the π-conjugated conductive polymer. It is a substance that develops conductivity in molecules. A well-known thing can be used for a dopant. Among these, it is particularly preferable to use a polyanion as a dopant from the viewpoint that the conductivity when the π-conjugated conductive polymer is doped can be further increased.

  A polyanion is a compound having an anionic group in the molecule. Specific examples of the polyanion include polystyrene sulfonic acid, polyvinyl sulfonic acid, polyacrylic acid ethyl sulfonic acid, polythienyl methyl sulfonic acid, and the like. These homopolymers may be sufficient and 2 or more types of copolymers may be sufficient. The combination of the π-conjugated conductive polymer and the dopant is not particularly limited, but a combination of polythiophenes and polyanions is preferable from the viewpoint of conductivity and availability of materials, and poly (3,4-ethylenedioxythiophene) and A combination of polystyrene sulfonic acids is more preferred.

  The mass ratio between the π-conjugated conductive polymer and the dopant needs to be 1: 1 to 1: 5. When the mass ratio of the dopant to the π-conjugated conductive polymer is smaller than 1: 1, the π-conjugated conductive polymer is not sufficiently doped, and the conductivity of the composite is lowered. On the other hand, when the mass ratio of the dopant to the π-conjugated conductive polymer is larger than 1: 5, the heat resistance of the composite deteriorates due to the influence of the excessive dopant. What is necessary is just to use what was synthesize | combined by the well-known method as a composite_body | complex which consists of (pi) conjugated system conductive polymer and a dopant. Further, an aqueous dispersion of a complex composed of a π-conjugated conductive polymer and a dopant may be used by replacing with an organic solvent.

  The content of each of (a) polyfunctional (meth) acrylate, (b) hollow silica fine particles, (c) π-conjugated conductive polymer and dopant in the coating solution for the low refractive index layer is (a ) Per 100 parts by mass of polyfunctional (meth) acrylate, (b) from 40 to 250 parts by mass of hollow silica fine particles (in terms of solid content in the hollow silica fine particle-dispersed sol), (c) from π-conjugated conductive polymer and dopant 1 to 25 parts by mass (solid content converted value) of the composite. When the content of the hollow silica fine particles is less than 40 parts by mass, the effect of reducing the refractive index of the low refractive index layer is low, and sufficient antireflection performance of the near infrared shielding film cannot be obtained. On the other hand, when the amount is more than 250 parts by mass, the content of the polyfunctional (meth) acrylate is relatively decreased, so that the scratch resistance of the near-infrared shielding film is lowered.

  Moreover, when the content of the complex composed of the π-conjugated conductive polymer and the dopant is less than 1 part by mass, sufficient antistatic performance of the near-infrared shielding film cannot be obtained, and more than 25 parts by mass. In such a case, since the content of the polyfunctional (meth) acrylate is relatively reduced, the scratch resistance of the near-infrared shielding film is lowered.

[Diluted solvent]
Any solvent can be used for the coating solution for the low refractive index layer. Specific examples of the solvent include alcohols such as methanol, ethanol, isopropyl alcohol, butanol, isobutyl alcohol and methyl glycol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methylcyclohexanone and diacetone alcohol, methyl acetate, Examples thereof include esters such as ethyl acetate and butyl acetate, and ethers such as propylene glycol monomethyl ether, tetrahydrofuran and 1,4-dioxane.

[Other ingredients]
In addition, other components can be added to the coating solution for the low refractive index layer within a range not impairing the effects of the present invention. Examples of such other components include additives such as a polymer, a polymerization initiator, a polymerization inhibitor, an antioxidant, a dispersant, a surfactant, a light stabilizer, and a leveling agent.

<Method for forming low refractive index layer>
The method for forming the low refractive index layer on the surface (one side) of the transparent substrate film is not particularly limited, but the coating solution for the low refractive index layer is a roll coating method, spin coating method, coil bar method, dip coating method, die coating method. Examples thereof include a method of irradiating ultraviolet rays or an electron beam after coating on the surface of the transparent substrate film by a coating method such as. By such a method, the coating solution for the low refractive index layer is cured to obtain a cured product, and a low refractive index layer is formed. As a method for applying the coating solution for the low refractive index layer, a method capable of continuously forming the low refractive index layer such as a roll coating method is preferable from the viewpoint of productivity.

  In addition, before applying the coating solution for the low refractive index layer to the surface of the transparent substrate film by a coating method such as a roll coating method, a spin coating method, a coil bar method, a dip coating method, or a die coating method, A pretreatment such as a discharge treatment may be performed.

<Near-infrared absorbing adhesive layer>
The near-infrared absorbing adhesive layer is a functional layer having both a near-infrared absorbing function and an adhesive function, and is laminated on the other surface on the opposite side where the low refractive index layer is laminated on the transparent substrate. A near-infrared absorptive adhesive layer is formed by hardening of a near-infrared absorptive adhesive containing (d) a (meth) acrylic adhesive resin composition and (e) a near-infrared absorbing dye. Although the film thickness of a near-infrared absorptive adhesive layer is not specifically limited, 15-30 micrometers is preferable and 20-25 micrometers is more preferable.

  The method for providing the near-infrared absorbing adhesive layer on the back surface (the other side) of the transparent base film is not particularly limited as long as it is a method for applying a near-infrared absorbing adhesive by a wet coating method. Conventionally known coating methods such as a coating method and a die coating method can be employed.

[(Meth) acrylic adhesive resin composition]
The (d) (meth) acrylic pressure-sensitive adhesive resin composition in the present invention is, for example, a polymer obtained by polymerizing an alkyl (meth) acrylate such as methyl (meth) acrylate or butyl (meth) acrylate and (meth) acrylic acid. Can be used. The monomer that forms the (meth) acrylic adhesive resin composition is not particularly limited, and a conventionally known polymer can be used.

  The acid value of the (meth) acrylic adhesive resin composition is 0 to 20 mgKOH / g, preferably 0 to 15 mgKOH / g, and more preferably 0 to 10 mgKOH / g. When this acid value is larger than 20 mgKOH / g, deterioration of the near-infrared absorbing dye is promoted when the near-infrared absorbing dye is added to the (meth) acrylic adhesive resin composition, which is not preferable.

  The monomer that forms the (meth) acrylic pressure-sensitive adhesive resin composition is not particularly limited. For example, alkyl (meth) acrylate such as methyl (meth) acrylate and butyl (meth) acrylate and (meth) acrylic acid are polymerized. A polymer can be used. In addition to (meth) acrylate, for example, an olefin monomer having an unsaturated double bond such as ethylene, vinyl acetate, styrene, or a copolymer with a vinyl monomer can also be used.

  In addition to (meth) acrylic acid, the (meth) acrylic adhesive resin composition is a monomer having a hydroxyl group such as 2-hydroxyethyl (meth) acrylate, or a carboxyl group such as maleic acid, itaconic acid or crotonic acid. It may be formed by containing a monomer having a functional group that reacts with an isocyanate group of an isocyanate-based cross-linking agent such as a monomer having. Thereby, the monomer having the functional group can be copolymerized with the (meth) acrylic acid to obtain a (meth) acrylic resin having a functional group, and the functional group is an isocyanate group of the isocyanate crosslinking agent. It can react with A to form a crosslinked structure, and the mechanical strength and the like of the near-infrared absorbing adhesive layer can be increased.

  Although the crosslinking agent used for a (meth) acrylic-type adhesive resin composition is not specifically limited, For example, an isocyanate type crosslinking agent etc. are used suitably. Other additives may be added to the adhesive resin composition as long as the functions of the present invention are not impaired. Examples of other additives include, but are not limited to, antioxidants and ultraviolet absorbers. Moreover, a conventionally well-known compound can be used for another additive.

[Near-infrared absorbing dye]
The (e) near-infrared absorbing dye in the present invention is selected from diimonium dyes or phthalocyanine dyes. Since these near-infrared absorbing dyes have a maximum absorption wavelength at a light wavelength of 800 to 1100 nm, they do not absorb visible light unnecessarily, and exhibit sufficient near-infrared absorbing ability for use in PDPs and the like. it can.

  The near-infrared absorbing dye selected from these diimonium dyes or phthalocyanine dyes is not particularly limited, and conventionally known compounds or commercially available products can be used. Examples of such a diimonium dye include CIR-1085, CIR-RL [above, trade names of diimonium dyes manufactured by Nippon Carlit Co., Ltd.], IRG-022, IRG-067 [above, Nippon Kayaku Co., Ltd. The name of the phthalocyanine dye such as e-excolor IR-10A, e-excolor IR-12, e-excolor IR-14, TX-EX-820, and TX-EX- 906B, TX-EX-910B, TX-EX-915 [above, trade names of phthalocyanine dyes manufactured by Nippon Shokubai Co., Ltd.] and the like.

  As for content of a near-infrared absorption pigment | dye, 0.5-3.0 mass parts is preferable with respect to 100 mass parts of (d) (meth) acrylic-type resin composition. When the content of the near-infrared absorbing dye is 0.5 to 3.0 parts by mass, a near-infrared absorbing adhesive layer having practically sufficient near-infrared absorbing ability and visible light transmittance can be obtained. When the content of the near-infrared absorbing dye is less than 0.5 parts by mass, the near-infrared absorbing ability cannot be sufficiently exhibited, and the visible light transmittance tends to decrease. On the other hand, when the content is more than 3.0 parts by mass, the adhesive performance of the near-infrared absorbing adhesive layer tends to decrease.

  The near-infrared absorbing dye is used after being dissolved in an organic solvent, but may be used in a fine particle dispersed state in order to improve durability. In this case, it is preferably present in a fine particle dispersed state having an average particle diameter of 0.001 to 0.1 μm, and more preferably present in a fine particle dispersed state having an average particle diameter of 0.005 to 0.03 μm. If the average particle size exceeds 0.1 μm, white blurring occurs due to light scattering, which is inappropriate. If the average particle size is less than 0.001 μm, the durability cannot be sufficiently exhibited by dissolution. is there.

  The dispersion method of the near infrared absorbing dye is not particularly limited, and a conventionally known dispersion method can be used. For example, a method of adding a diimonium salt compound to an organic solvent while stirring little by little, adding glass beads and physically pulverizing with a paint shaker can be mentioned, but is not limited thereto.

(Color correction dye)
Further, the near-infrared absorbing adhesive layer may contain a color correction dye having a maximum absorption wavelength in a region of light wavelength of 380 to 780 nm (visible light wavelength region). By including this color correction pigment, color reproducibility can be improved when the near-infrared absorbing adhesive layer is used in a PDP or the like. The color correction dye having a maximum absorption wavelength in the light wavelength region of 380 to 780 nm is not particularly limited, and examples thereof include azaporphyrin compounds, cyanine compounds, other squarylium compounds, azomethine compounds, polymethine compounds, xanthene compounds, Conventionally known compounds such as pyromethene compounds, isoindolinone compounds, quinacridone compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, and dioxazine compounds can be used. Among these, an azaporphyrin-based compound having good durability performance is preferable. Among the azaporphyrin compounds, tetraazaporphyrin compounds having good absorption characteristics are preferable. Examples of commercially available products include TAP-2, TAP-18 (tetraazaporphyrin compound manufactured by Yamada Chemical Co., Ltd.), PD- 320, PD-321 (tetraazaporphyrin compound manufactured by Yamamoto Kasei Co., Ltd.) and the like are used.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. In addition, the part in each example shows a mass part and% represents the mass%.

(Preparation of coating solution for low refractive index layer)
(a) The following commercial products were used as polyfunctional (meth) acrylates. In addition, in the below-mentioned Tables 1-5, the kind of (a) polyfunctional (meth) acrylate is displayed by the commercial item name.
DPHA: dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., trade name: DPHA, hexafunctional acrylate)
UV7600B: manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name: purple light UV7600B, hexafunctional urethane acrylate PE-3A: pentaerythritol triacrylate (manufactured by Kyoeisha Chemical Co., Ltd., trade name: light acrylate PE-3A, trifunctional acrylate)
OD2H2A: 1,10-Diacryloyloxy-2,9-dihydroxy-4,4,5,5,6,6,7,7, -octafluorodecane (bifunctional acrylate)

(b) The hollow silica fine particles have an average particle diameter of 60 nm, a refractive index of 1.25, a porosity of 40 to 45%, a specific surface area of 130 m ² / g, and a mass reduction ratio by thermal mass measurement (TG) of 3.6%. This was used as an organosol in which modified hollow silica fine particles were dispersed (modified hollow silica fine particle-dispersed sol). In addition, the composition of the composite consisting of (c) a π-conjugated conductive polymer and a dopant is shown in Tables 1 to 5 described later. In the said Tables 1-5, the mixture ratio of (b) hollow silica fine particles and (c) composite_body | complex is a solid content conversion value.

(Preparation of coating liquid for low refractive index layer (L-1 to L-14))
The composition for low refractive index layer (a), (b), (c) shown in Table 1 and a photopolymerization initiator [Ciba Specialty Chemicals, Inc., trade name: Irgacure 907] 12 .5 parts and 4000 parts of isopropyl alcohol were mixed to prepare low refractive index layer coating liquids (L-1 to L-14).

(Preparation of coating liquid for low refractive index layer (L-15 to L-18))
Preparation of coating solutions for low refractive index layers (L-1 to L-14), except that the compositions (a), (b) and (c) for the low refractive index layer were as shown in Table 2. Similarly, coating solutions for low refractive index layers (L-15 to L-18) were prepared.

(Preparation of coating solution for low refractive index layer (L-19 to L-23))
Preparation of coating solutions for low refractive index layers (L-1 to L-14), except that the compositions (a), (b) and (c) for the low refractive index layer were as shown in Table 3. Similarly, coating solutions for low refractive index layers (L-19 to L-23) were prepared.

(Preparation of coating liquid for low refractive index layer (L-24 to L-28))
Preparation of coating solutions for low refractive index layers (L-1 to L-14) except that the compositions (a), (b) and (c) for the low refractive index layer were as shown in Table 4. Similarly, coating solutions for low refractive index layers (L-24 to L-28) were prepared.

(Preparation of coating liquid for low refractive index layer (L-29 to L-35))
Preparation of coating solutions for low refractive index layers (L-1 to L-14), except that the compositions (a), (b) and (c) for the low refractive index layer were as shown in Table 5. Similarly, coating solutions for low refractive index layers (L-29 to L-35) were prepared.

(Preparation of near-infrared absorbing adhesive B-1)
94.6 parts by mass of n-butyl acrylate (nBA), 4.4 parts by mass of acrylic acid (AA), 1 part by mass of 2-hydroxyethyl methacrylate (2HEMA), 0.4 parts by mass of azobisisobutyronitrile, ethyl acetate 90 parts by mass and 60 parts by mass of toluene were mixed, and the mixture was heated to 65 ° C. under a nitrogen atmosphere and subjected to a polymerization reaction for 10 hours to prepare an acrylic resin composition (acid value: 9 mgKOH / g). (D) (meth) acrylic adhesive by adding 1 part by weight of coronate L [polyisocyanate manufactured by Nippon Polyurethane Co., Ltd.] to this acrylic resin composition and ethyl acetate so that the solid content concentration is 20% by weight. A solid content concentration 20% by mass solution a-1 of the resin composition was obtained. Next, in a glass container, (e) bis [bis (trifluoromethanesulfone) imidic acid] -N, N, N ′, N′-tetrakis [p-di (isopropyloxy) which is a diimonium dye as a near infrared absorbing dye. After adding 0.2 parts by weight of ethyl) aminophenyl] -p-phenylenediamine, 3.8 parts by weight of toluene, and glass beads having a particle size of 0.8 mm, the mixture was shaken with a paint shaker for 3 hours, and then the glass beads were removed. By filtration, a fine particle dispersion b-1 (solid content concentration 5 mass%, average particle diameter 0.015 μm) of diimonium dye was obtained. The average particle size of the near-infrared absorbing dye was measured by a dynamic light scattering theory / frequency matrix analysis method (FFT method) using nanotracUPA-EX150 (a particle size distribution measuring machine manufactured by Nikkiso Co., Ltd.). Subsequently, 26 parts by mass of the fine particle dispersion b-1 (1.3 in terms of solids) was added to a solution a-1 having a solids concentration of 20% by mass of 500 parts by mass of the (d) (meth) acrylic adhesive resin composition. (Mass part) By adding and stirring and mixing, near-infrared absorptive adhesive B-1 was obtained.

(Preparation of near-infrared absorbing adhesive B-2)
95.4 parts by mass of n-butyl acrylate (nBA), 4.6 parts by mass of 2-hydroxyethyl methacrylate (2HEMA), 0.2 parts by mass of azobisisobutyronitrile, 90 parts by mass of ethyl acetate, 60 parts by mass of toluene The mixture was mixed, and the mixture was heated to 65 ° C. under a nitrogen atmosphere to carry out a polymerization reaction for 14 hours to prepare an acrylic resin composition (acid value 0 mg KOH / g). (D) (meth) acrylic adhesive by adding 1 part by mass of BHS8515 [Toyo Ink Manufacturing Co., Ltd. polyisocyanate] and ethyl acetate so that the solid content concentration is 20% by mass to this acrylic resin composition A solid content concentration 20 mass% solution a-2 of the resin composition was obtained. Next, (e) bis (hexafluoroantimonic acid) -N, N, N ′, N′-tetrakis [p-di (cyclohexylethyl) aminophenyl]-, which is a diimonium dye as a near infrared absorbing dye, is placed in a glass container. After adding 0.2 parts by weight of p-phenylenediamine, 3.8 parts by weight of toluene, and glass beads having a particle diameter of 0.8 mm, and stirring and shaking with a paint shaker for 4 hours, the glass beads are separated by filtration to obtain a diimonium dye. Fine particle dispersion b-2 (solid content concentration 5 mass%, average particle size 0.010 μm) was obtained. Subsequently, the fine particle dispersion b-2 was added in an amount of 26 parts by mass (1.3 in terms of solids) to 500 parts by mass of the (d) (meth) acrylic pressure-sensitive adhesive resin composition having a solid content of 20% by mass. By adding 0.11 part by mass of PD-320 [tetraazaporphyrin compound manufactured by Yamamoto Kasei Co., Ltd.] as a color correction dye, and stirring and mixing, a near-infrared absorbing adhesive B-2 was obtained. .

(Preparation of near-infrared absorbing adhesive B-3)
The above (d) (meth) acrylic pressure-sensitive adhesive resin composition having a solid content concentration of 20% by mass solution a-1 (500 parts by mass), (e) IR-14 as an infrared absorbing dye [Nippon Shokubai Phthalocyanine Compound] ] 0.3 parts by mass, TXEX820 [Nippon Catalysts phthalocyanine compound] 0.55 parts by mass, TXEX915 [Nippon Catalysts phthalocyanine compound] 0.58 parts by mass, and TAP-2 as a color correction dye [Tetraazaporphyrin compound manufactured by Yamada Chemical Co., Ltd.] 0.12 parts by mass were added and mixed by stirring to obtain near-infrared absorbing adhesive B-3.

(Example 1-1)
A low refractive index layer coating liquid L-1 is coated on a transparent substrate film made of polyethylene terephthalate (PET) having a thickness of 100 μm (trade name: A4300, manufactured by Toyobo Co., Ltd.), and the optical film thickness after curing is kλ / 4 (k: 1, λ: 550 nm) was applied by a gravure coating method, dried, and then cured by irradiation with ultraviolet rays of 400 mJ / cm ^{2 in} a nitrogen atmosphere. Subsequently, the near-infrared absorbing adhesive B-1 was applied on a PET-made separate film using an auto applicator so that the thickness after drying was 25 μm, dried at 90 ° C. for 2 minutes, and then a transparent base film The near-infrared shielding film of Example 1-1 was obtained by bonding to the other surface opposite to the surface on which the low refractive index layer was formed and storing at 30 ° C. for 5 days. The near-infrared shielding film of Example 1-1 had a 850 nm transmittance of 12% and a 950 nm transmittance of 5%.

About the obtained near-infrared shielding film of Example 1-1, evaluation of the visibility reflectance, surface resistivity, surface hardness, heat resistance, scratch resistance, and near-infrared absorptivity was performed by the methods described below. The evaluation results are shown in Table 1.
(1) Visibility reflectance In order to remove the reflection on the back surface of the measurement surface, the back surface is roughened with sandpaper and painted with a black paint by a spectrophotometer [trade name: U-best 560 manufactured by JASCO Corporation]. The 5 ° and −5 ° regular reflection spectra of light wavelengths of 380 nm to 780 nm were measured. Using the obtained spectral reflectance of 380 nm to 780 nm and the relative spectral distribution of the CIE standard illuminant D65, the tristimulus value Y of the object color due to reflection in the XYZ color system assumed in JIS Z8701 is obtained as the luminous reflectance. (%).
(2) Surface resistivity The surface resistivity (Ω / □) of the antireflection film was measured using a digital insulation meter [manufactured by Toa DKK, trade name: SM-8220]. In Tables 1 to 3, “RANGE OVER” means that the surface resistivity increased as it exceeded the measurement limit.
(3) Heat resistance The antireflection film was left in a thermostat set at 80 ° C., taken out from the thermostat after 1000 hours, and the surface resistivity was measured. Compared with the surface resistivity measured before putting in the thermostatic bath, it was marked with ○ when the increase in surface resistivity was suppressed within 2 digits, and when the surface resistivity was increased by 3 digits or more.
(4) Scratch resistance An anti-reflective film with # 0000 steel wool fixed to the tip of an eraser abrasion tester manufactured by Honko Seisakusho Co., Ltd. and a load of 2.5 N (250 gf) and 1 N (100 gf) applied. The surface scratches after 10 reciprocating rubs on the surface were visually observed and evaluated according to the following 6 grades A to E.
A: No scratch, A ': 1-3 scratches, B: 4-10 scratches, C: 11-20 scratches, D: 21-30 scratches, E: 31 or more (5) Near infrared absorption ability Measurement was performed using UV-1600PC (product name of spectrophotometer manufactured by Shimadzu Corporation). If the near-infrared transmittances at wavelengths of 850 nm and 950 nm were both less than 15%, the result was ◯, and if it was 15% or more, the result was ×.

(Example 1-2 to Example 1-14)
In Example 1-1, instead of the low refractive index layer coating liquid (L-1), the low refractive index layer coating liquids (L-2 to L-14) were used, and (B The near-infrared shielding films of Examples 1-2 to 1-14 were obtained in the same manner as Example 1-1 except that -1 to B-3) were used. About each obtained near-infrared shielding film, the result of having evaluated the visibility reflectance, surface resistivity, heat resistance, scratch resistance, and near-infrared absorption ability by the method similar to Example 1-1 is shown in Table 1. Show.

  As shown in Table 1, in Examples 1-1 to 1-14, a single layer configuration has sufficient antireflection performance, excellent antistatic performance, and good heat resistance and scratch resistance. A near-infrared shielding film could be obtained.

(Example 2-1 to Example 2-4)
In Example 1-1, instead of the coating solution for low refractive index layer (L-1), the coating solution for low refractive index layer (L-15 to L-18) was used, and (B The near-infrared shielding film of Example 2-1 to Example 2-4 was obtained in the same manner as Example 1-1 except that -1 to B-3) were used. About each obtained near-infrared shielding film, the result of having evaluated the visibility reflectance, surface resistivity, heat resistance, scratch resistance, and near-infrared absorptivity by the method similar to Example 1-1 is shown in Table 2. Show.

  As shown in Table 2, Examples 2-1 to 2-4 have a single layer configuration and good antireflection performance, good antistatic performance, and good heat resistance and scratch resistance. A near infrared shielding film could be obtained.

(Example 3-1 to Example 3-5)
In Example 1-1, instead of the low refractive index layer coating liquid (L-1), the low refractive index layer coating liquids (L-19 to L-23) were used, and (B -1 to B-3) were used in the same manner as Example 1-1 to obtain near-infrared shielding films of Example 3-1 to Example 3-5. About the obtained near-infrared shielding films, the evaluation results of visibility reflectance, surface resistivity, heat resistance, scratch resistance, and near-infrared absorptivity were evaluated in the same manner as in Example 1-1. Show.

  As shown in Table 3, Examples 3-1 to 3-5 have a single layer configuration and good antireflection performance, good antistatic performance, and good heat resistance and scratch resistance. A near-infrared shielding film could be obtained.

(Example 4-1 to Example 4-5)
In Example 1-1, instead of the low refractive index layer coating liquid (L-1), the low refractive index layer coating liquids (L-24 to L-28) were used, and (B The near-infrared shielding films of Examples 4-1 to 4-5 were obtained in the same manner as Example 1-1 except that -1 to B-3) were used. Table 4 shows the results obtained by evaluating the visibility reflectance, surface resistivity, heat resistance, scratch resistance, and near-infrared absorptivity of the obtained near-infrared shielding films in the same manner as in Example 1-1. Show.

  As shown in Table 4, Examples 4-1 to 4-5 have a single layer configuration and good antireflection performance, good antistatic performance, and good heat resistance and scratch resistance. A near infrared film could be obtained.

(Comparative Example 1-1 to Comparative Example 1-6)
In Example 1-1, instead of the low refractive index layer coating liquid (L-1), the low refractive index layer coating liquids (L-29 to L-34) were used, and (B -1 to B-3) were used in the same manner as in Example 1-1 to obtain near-infrared shielding films of Comparative Examples 1-1 to 1-6. About each obtained near-infrared shielding film, the result of having evaluated visibility reflectance, surface resistivity, heat resistance, scratch resistance, and near-infrared absorption ability by the method similar to Example 1-1 is shown in Table 5. Show.

(Comparative Example 1-7)
On a polyethylene terephthalate (PET) film having a thickness of 100 μm (trade name: A4300, manufactured by Toyobo Co., Ltd.), a coating solution for low refractive index layer (L-35) is used, and the optical film thickness after curing is kλ / 4 ( k: 1, λ: 550 nm), applied by a gravure coating method, dried, and then cured by irradiation with ultraviolet rays of 400 mJ / cm ^{2 in} a nitrogen atmosphere. About the obtained near-infrared shielding film of Comparative Example 1-7, evaluation of the visibility reflectance, surface resistivity, heat resistance, scratch resistance, and near-infrared absorptivity was performed in the same manner as in Example 1-1. The results are shown in Table 5.

  As shown in Table 5, since Comparative Example 1-1 did not have a complex composed of a π-conjugated conductive polymer and a dopant, the antistatic performance was not exhibited. In Comparative Example 1-2, since the content of the complex composed of the π-conjugated conductive polymer and the dopant is large, the content of the polyfunctional (meth) acrylate is relatively decreased, and the scratch resistance is deteriorated. It was a result of doing. In Comparative Example 1-3, since the content of the hollow silica fine particles is too small, the refractive index of the cured film is not sufficiently lowered, resulting in high visibility reflectance and poor antireflection performance.

Moreover, in Comparative Example 1-4, since the content of the hollow silica fine particles was excessive, the content of the polyfunctional (meth) acrylate was relatively decreased, and the scratch resistance was deteriorated. In Comparative Example 1-5, since the amount of the dopant is too small with respect to the π-conjugated conductive polymer, the π-conjugated conductive polymer is not sufficiently doped, resulting in low conductivity and antistatic properties. Declined. In Comparative Example 1-6, since the amount of the dopant was too much with respect to the π-conjugated conductive polymer, the heat resistance was deteriorated due to the influence of the excessive dopant. Furthermore, in Comparative Example 1-7, since there was no near-infrared absorptive adhesive layer, the near-infrared absorptivity was bad.

Claims (6)

A low-refractive index layer is directly laminated on one surface of the transparent substrate film, and a near-infrared shielding film in which a near-infrared absorbing adhesive layer is laminated on the other surface of the transparent substrate film,
The low refractive index layer contains (a) polyfunctional (meth) acrylate, (b) hollow silica fine particles, and (c) a complex composed of a π-conjugated conductive polymer and a dopant,
1 to 25 parts by mass of a composite comprising (b) 40 to 250 parts by mass of hollow silica fine particles, (c) a π-conjugated conductive polymer and a dopant per 100 parts by mass of (a) polyfunctional (meth) acrylate Including
(C) The mass ratio of the π-conjugated conductive polymer and the dopant in the complex composed of the π-conjugated conductive polymer and the dopant is 1: 1 to 1: 5,
The near-infrared absorbing layer includes (d) a (meth) acrylic adhesive resin composition, and (e) a near-infrared absorbing dye,
The (d) (meth) acrylic adhesive resin composition includes a (meth) acrylic resin having an acid value of 0 to 20 mgKOH / g,
(E) The near infrared ray absorbing film, wherein the near infrared ray absorbing dye is a diimonium dye or a phthalocyanine dye.   The near-infrared shielding film according to claim 1, wherein the π-conjugated conductive polymer is a polythiophene.   The near-infrared shielding film according to claim 2, wherein the polythiophene is poly (3,4-ethylenedioxythiophene).   The near-infrared shielding film according to claim 1, wherein the π-conjugated conductive polymer is polypyrrole or polyaniline.   The near-infrared shielding film according to any one of claims 1 to 4, wherein the dopant is a polyanion. The near-infrared shielding film according to claim 5, wherein the polyanion is polystyrene sulfonic acid.