JP2018154040A - Optical film, and transparent conductive film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical film having a transparent substrate containing cycloolefin-based resin, which hardly causes scratches and hardly causes cracks when being bent.SOLUTION: An optical film 1 has a transparent substrate 2 which contains cycloolefin-based resin and has a first surface 2a and a second surface 2b positioned on an opposite side to the first surface 2a, and a first layer 3 provided on the first surface 2a of the transparent substrate 2. The first layer 3 contains an acrylic resin and metal oxide particles. The metal oxide particles have an average particle diameter in a range of 10 nm to 100 nm. A content of the metal oxide particles is in a range of 20 mass% to 50 mass% relatively to the mass of the first layer 3.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical film and a transparent conductive film, and more particularly to an optical film and a transparent conductive film that are suitably used for windshields, sunglasses, and display panels of electrical equipment.

  Conventionally, in order to reduce retardation generated when an optical film is provided on a display panel or the like, it has been proposed to use a film containing a cycloolefin resin as a base material in the optical film. In order to protect the film containing a cycloolefin resin, for example, in Patent Document 1, curing including a high molecular weight component having a weight average molecular weight of 10,000 or more and a content of 90% by weight or less and 80% by weight or more. Providing a resin layer on the surface of a cycloolefin resin film has been proposed.

JP-A-2015-115171

  However, the cured resin layer in Patent Document 1 has a problem that it is resistant to cracking but easily damaged. Increasing the hardness of the cured resin layer to suppress scratches tends to cause cracking. For example, if the optical film is wound to be rolled into a roll, it may be cracked. There is.

  The present invention has been made in view of the above points, and an object of the present invention is an optical film including a transparent substrate containing a cycloolefin-based resin, which can be hardly scratched and cracked when bent. It is providing the optical film which can make it hard to produce, and a transparent conductive film provided with this optical film.

  An optical film according to the present invention includes a cycloolefin resin, a transparent substrate having a first surface and a second surface located on the opposite side of the first surface, and provided on the first surface of the transparent substrate. A first layer, the first layer includes an acrylic resin and metal oxide particles, and the metal oxide particles have an average particle diameter in a range of 10 nm to 100 nm, and the metal oxide Content of an object particle exists in the range of 20 mass%-50 mass% with respect to the mass of the said 1st layer.

  In the optical film according to the present invention, the first layer may have a thickness in the range of 500 nm to 10000 nm.

  In the optical film according to the present invention, the first layer may have a pencil hardness higher than B in a pencil hardness test in accordance with JIS K5400.

  In the optical film according to the present invention, the metal oxide particles in the first layer may include at least one of silicon dioxide particles and alumina particles.

  The optical film according to the present invention may further include an anti-blocking layer provided on the second surface of the transparent substrate, and the anti-blocking layer may include metal oxide particles.

  In the optical film according to the present invention, the refractive index of the first layer may be in the range of 1.50 to 1.65, and the first layer is provided on the opposite side of the transparent substrate from the transparent substrate. The second layer may further include an acrylic resin and metal oxide particles, the second layer has a thickness in the range of 10 nm to 100 nm, and has a refractive index. May be in the range of more than 1.65 and 1.95 or less.

  The transparent conductive film according to the present invention is opposite to the optical film, an inorganic layer provided on the optical film opposite to the transparent substrate of the second layer, and the transparent substrate of the inorganic layer. And a transparent conductive layer provided on the side.

  According to the present invention, it is possible to obtain an optical film and a transparent conductive film that are hardly scratched and that are less likely to be cracked when bent.

FIG. 1 shows a schematic cross-sectional view of an optical film according to an embodiment of the present invention. FIG. 2 shows a schematic cross-sectional view of a transparent conductive film according to an embodiment of the present invention.

  Hereinafter, modes for carrying out the present invention will be described.

<Optical film>
The optical film 1 which concerns on this embodiment is demonstrated with reference to FIG.

  The optical film 1 is a transparent film and includes a transparent substrate 2. The transparent substrate 2 has a first surface 2a and a second surface 2b located on the opposite side of the first surface 2a in the thickness direction. The transparent substrate 2 contains a cycloolefin resin. When the transparent substrate 2 contains a cycloolefin-based resin, retardation that occurs when light passes through the transparent substrate 2 can be reduced. The amount of the cycloolefin resin contained in the transparent substrate 2 is not particularly limited. The transparent substrate 2 can contain only a cycloolefin resin, for example.

  The cycloolefin-based resin is a resin in which a cyclic olefin structure is included in at least a part of the main chain in the molecule. That is, the cycloolefin resin is a polymer of a raw material monomer containing a cycloolefin monomer. Such a raw material monomer may contain only a cycloolefin monomer, or may contain an ethylenically unsaturated monomer such as ethylene or propylene in addition to the cycloolefin monomer. The cycloolefin monomer preferably has a norbornene skeleton. In this case, the cycloolefin resin preferably contains a norbornene resin. The norbornene-based resin can improve the transparency of the transparent substrate 2 and reduce haze, and can further reduce retardation.

  The optical film 1 includes a first layer 3 provided on the first surface 2 a of the transparent substrate 2. The first layer 3 is a transparent layer and may be in contact with the first surface 2 a of the transparent substrate 2. The first layer 3 includes an acrylic resin and metal oxide particles. By including the acrylic resin in the first layer 3, it is possible to impart appropriate flexibility to the first layer 3, and even if the optical film 1 is bent, the optical film 1 can be made difficult to break. Moreover, hardness can be provided to the 1st layer 3 when the 1st layer 3 contains a metal oxide particle, and, thereby, the optical film 1 becomes difficult to be damaged. The thickness of the first layer 3 is preferably in the range of 500 nm to 10000 nm. In this case, the first layer 3 can have both hardness and flexibility. In particular, the thickness of the first layer 3 is preferably in the range of 800 nm to 1200 nm.

  The first layer 3 preferably has a higher hardness than the transparent substrate 2. In particular, the pencil hardness of the first layer 3 is preferably higher than B. The pencil hardness of the present embodiment is obtained, for example, by a pencil hardness test based on JIS K5400.

  Acrylic resin contains the polymer of the unsaturated compound containing the compound which has a (meth) acryl group, for example. An unsaturated compound can also contain the other monomer (henceforth a monomer (A)) copolymerizable with the compound which has a (meth) acryl group.

  The acrylic resin may be formed from, for example, a thermosetting resin composition, a thermoplastic resin, an ultraviolet curable resin composition, or an electron beam curable resin composition. Among these, the ultraviolet curable resin composition is preferable from the convenience of obtaining an acrylic resin. Moreover, a polymer can be formed from an unsaturated compound by arbitrary polymerization initiators. This polymerization initiator is preferably one that generates radicals to initiate the polymerization reaction. Such radicals are generated by performing an arbitrary treatment such as ultraviolet irradiation, heating, or electron beam irradiation according to the properties of the polymerization initiator.

  When the acrylic resin is formed from a thermosetting resin composition, the thermosetting resin composition can include an unsaturated compound and an organic peroxide serving as a polymerization initiator. Examples of the organic peroxide include t-butylperoxy-2-ethylhexyl monocarbonate, t-butylperoxybenzoate, t-butylcumyl peroxide, dicumyl peroxide, α, α′-di (t-butylperoxide). Oxy) diisopropylbenzene, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane.

  When the acrylic resin is formed from an ultraviolet curable resin composition, the ultraviolet curable resin composition includes at least one component of an unsaturated compound, a photopolymerization initiator serving as a polymerization initiator, and a photosensitizer. Can be included. Examples of the photopolymerization initiator include acetophenones, benzophenones, α-amyloxime esters, and thioxanthones. Examples of the photosensitizer include n-butylamine, triethylamine, tri-n-butylphosphine, and thioxanthone.

  The compound having a (meth) acryl group can include, for example, a resin having a (meth) acrylate group. Examples of such resins include oligomers and prepolymers of relatively low molecular weight polyfunctional compounds and (meth) acrylates. Examples of the polyfunctional compound include polyester resins, polyether resins, acrylic resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, and polyhydric alcohols.

  The monomer (A) is a compound different from the compound having a (meth) acryl group, and can be a reactive diluent in the composition. Monomers (A) include, for example, monofunctional monomers such as ethyl (meth) acrylate, ethylhexyl (meth) acrylate, styrene, methylstyrene, and N-vinylpyrrolidone; and trimethylolpropane tri (meth) acrylate, hexane Diol (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate And polyfunctional monomers of neopentyl glycol di (meth) acrylate.

  When the acrylic resin is formed from a thermoplastic resin, the thermoplastic resin includes a polymer of an unsaturated compound, and has a property of being melted by heating and re-cured by cooling. It is good to be.

  The acrylic resin may be a dried and cured product of a binder composition containing a polymer of an unsaturated compound and an arbitrary solvent. In this case, the first layer 3 is formed from a mixture of the binder composition and the metal oxide particles. Such a mixture is formed on the first surface 2a of the transparent substrate 2 by, for example, a wet method.

  The metal oxide particles contained in the first layer 3 have an average particle diameter in the range of 10 nm to 100 nm, preferably in the range of 20 nm to 50 nm. When the average particle diameter is 10 nm or more, scratching of the optical film 1 can be suppressed, and when the average particle diameter is 100 nm or less, cracking of the optical film 1 starting from the metal oxide particles can be suppressed. For this reason, damage to the optical film 1 can be suppressed while suppressing cracking of the optical film 1. The average particle diameter of the present embodiment is a volume-based arithmetic average value calculated from a particle size distribution measured by a laser diffraction / scattering method.

  Further, the content of the metal oxide particles is in the range of 20% by mass to 50% by mass, more preferably in the range of 30% by mass to 40% by mass with respect to the mass of the first layer 3. When the content is 20% by mass or more, scratching of the optical film 1 can be suppressed, and when the content is 50% by mass or less, cracking of the optical film 1 starting from the metal oxide particles is prevented. While suppressing, the transparency of the optical film 1 can be made hard to be impaired by the metal oxide particles. For this reason, while suppressing the crack of the optical film 1, the damage of the optical film 1 can be suppressed and the good transparency of the optical film 1 can be maintained.

  The metal oxide particles in the first layer 3 preferably include at least one of silicon dioxide particles and alumina particles. These particles can particularly contribute to the suppression of damage to the optical film 1.

  In forming the first layer 3, for example, a mixture containing an unsaturated compound and metal oxide particles is applied to the first surface 2 a of the transparent substrate 2. Alternatively, a mixture containing a binder composition containing a polymer of an unsaturated compound and metal oxide particles may be applied to the first surface 2a of the transparent substrate 2 by a wet method. The mixture thus applied is formed on the first surface 2 a of the transparent substrate 2.

  When applying the mixture, the mixture may be applied directly to the first surface 2 a of the transparent substrate 2. Examples of the application method of the mixture include a wire bar coating method, a roll coating method, a spin coating method, and a curtain coating method.

  When the mixture includes an unsaturated compound and a polymerization initiator, the polymerization reaction of the unsaturated compound is started by applying a treatment according to the properties of the polymerization initiator, and the applied mixture is transferred to the first surface of the transparent substrate 2. The first layer 3 can be formed by curing on 2a.

  When the mixture includes a binder composition, the first layer 3 can be formed by drying and curing the applied mixture on the first surface 2 a of the transparent substrate 2.

  Moreover, when the polymer of an unsaturated compound is contained in a thermoplastic resin, you may heat-knead a thermoplastic resin and a metal oxide particle, and may produce a mixture. Then, the mixture may be directly applied to the first surface 2a of the transparent substrate 2 by an application method such as a wire bar coating method, a roll coating method, a spin coating method, or a curtain coating method. The first layer 3 can be formed by cooling and curing the mixture thus applied. Moreover, you may form previously the mixture obtained by heat kneading in a sheet form. Then, the sheet-like mixture is placed on the first surface 2a of the transparent substrate 2 to produce a laminated body, and the laminated body is subjected to, for example, a heating press or a heating roll, so that the first layer 3 becomes the transparent substrate 2 And may be formed integrally.

  In addition, a step of roughening the first surface 2a of the transparent substrate 2 in advance by an etching process may be included before the first layer 3 is formed. In this case, the adhesion between the transparent substrate 2 and the first layer 3 can be improved. Examples of the etching treatment include physical surface treatment such as plasma treatment, corona discharge treatment, and flame treatment; and chemical surface treatment with a coupling agent, acid, or alkali agent.

  The optical film 1 can include a second layer 4 provided on the opposite side of the first layer 3 from the transparent substrate 2. That is, the transparent substrate 2, the first layer 3, and the second layer 4 are preferably laminated in this order. Such a second layer 4 is a transparent layer and may be in contact with the surface of the first layer 3.

  The second layer 4 has a higher refractive index than the first layer 3. When the optical film 1 includes the second layer 4, when the optical film 1 and the transparent conductive layer 7 overlap, the transparent conductive layer 7 can be hardly seen.

  When the optical film 1 includes the second layer 4, the refractive index of the first layer 3 is preferably in the range of 1.50 to 1.65. On the other hand, the refractive index of the second layer 4 is preferably in the range of more than 1.65 and not more than 1.95, and the thickness is preferably in the range of 10 nm to 100 nm. In this case, the optical film 1 can make the transparent conductive layer 7 especially difficult to visually recognize.

  Further, the second layer 4 can include an acrylic resin and metal oxide particles. In this case, the average particle diameter of the metal oxide particles is preferably in the range of 20 to 50 nm.

  When the second layer 4 includes metal oxide particles, the refractive index of the second layer 4 is easily adjusted to the above range. The metal oxide particles in the second layer 4 can include, for example, at least one kind of particles selected from the group consisting of silicon dioxide particles, alumina particles, and zirconia particles. In particular, the second layer 4 preferably contains zirconia particles as metal oxide particles. In addition to the above particles, if there are particles suitable for the second layer 4, these particles can also be used as metal oxide particles. In addition, the content of the metal oxide particles is preferably in the range of 50% by mass to 60% by mass with respect to the mass of the second layer 4.

  Further, when the second layer 4 includes an acrylic resin, the acrylic resin may be the same as the acrylic resin used for the first layer 3. In this case, moderate flexibility can be imparted to the second layer 4.

  In forming the second layer 4, for example, a mixture containing an unsaturated compound and metal oxide particles is placed on the side opposite to the second surface 2 b in the thickness direction of the first layer 3. Can be applied to the surface. Further, a mixture containing a binder composition containing a polymer of an unsaturated compound and metal oxide particles may be applied to the surface of the first layer 3 by a wet method. The mixture thus applied is formed on the surface of the first layer 3.

  When applying the mixture, the mixture may be applied directly to the surface of the first layer 3. Examples of the application method of the mixture include a wire bar coating method, a roll coating method, a spin coating method, and a curtain coating method.

  When the mixture contains an unsaturated compound and a polymerization initiator, the polymerization reaction of the unsaturated compound is started by applying a treatment according to the properties of the polymerization initiator, and the applied mixture is placed on the surface of the first layer 3. The second layer 4 can be formed by curing with.

  When the mixture includes a binder composition, the second layer 4 can be formed by drying and curing the applied mixture on the surface of the first layer 3.

  Moreover, when the polymer of an unsaturated compound is contained in a thermoplastic resin, you may heat-knead a thermoplastic resin and a metal oxide particle, and may produce a mixture. Then, the mixture may be directly applied to the surface of the first layer 3 by a coating method such as a wire bar coating method, a roll coating method, a spin coating method, or a curtain coating method. The second layer 4 can be formed by cooling and curing the mixture thus applied. Moreover, you may form previously the mixture obtained by heat kneading in a sheet form. Then, a sheet-like mixture is placed on the surface of the first layer 3 to produce a laminate, and the laminate 4 is subjected to, for example, a heating press or a heating roll, so that the second layer 4 becomes the first layer 3. Further, it may be formed integrally with the transparent substrate 2.

  The optical film 1 can include an anti-blocking layer 5 provided on the second surface 2 b of the transparent substrate 2. The anti-blocking layer 5 is a transparent layer and may be in contact with the second surface 2 b of the transparent substrate 2. The anti-blocking layer 5 has a concavo-convex structure on its outer surface (exposed surface). The outer surface of the anti-blocking layer 5 is located on the side opposite to the second surface 2 b of the transparent substrate 2 in the thickness direction of the anti-blocking layer 5.

  In the manufacturing process, the optical film 1 provided with the anti-blocking layer 5 is wound into a roll shape or cut into a predetermined size, for example. When such an optical film 1 is stacked up and down, the uneven structure of the anti-blocking layer 5 makes it difficult for the upper and lower optical films 1 and 1 to stick to each other. The property of the optical film 1 that makes it difficult to stick with such an uneven structure is also referred to as anti-blocking property.

  In order to impart antiblocking properties to the antiblocking layer 5, metal oxide particles can be included in the antiblocking layer 5. In this case, an uneven structure is formed on the outer surface of the anti-blocking layer 5 by the metal oxide particles.

  The metal oxide particles in the anti-blocking layer 5 can include at least one particle selected from the group consisting of silicon dioxide particles, alumina particles, and zirconia particles, for example. In particular, the metal oxide particles preferably include silicon dioxide particles. The average particle size of the metal oxide particles is preferably in the range of 50 nm to 5000 nm.

  When the anti-blocking layer 5 contains metal oxide particles, the anti-blocking layer 5 can also suppress damage to the optical film 1. The content of the metal oxide particles with respect to the mass of the anti-blocking layer 5 can be set to a predetermined content such that the anti-blocking layer 5 can sufficiently contribute to the suppression of scratches on the optical film 1 and impart anti-blocking properties. . The content of the metal oxide particles is preferably in the range of 5 to 40% by mass with respect to the mass of the antiblocking layer 5, for example.

  In addition, the anti-blocking layer 5 is preferably set to a predetermined thickness that can sufficiently contribute to the suppression of damage to the optical film 1, and specifically, set to a thickness within a range of 500 to 10,000 nm. It is preferable that

  The anti-blocking layer 5 can further contain an acrylic resin in addition to the metal oxide particles. This acrylic resin may be the same as the acrylic resin for use in the first layer 3. In this case, moderate flexibility can be imparted to the anti-blocking layer 5.

  In forming the anti-blocking layer 5, for example, a mixture containing an unsaturated compound and metal oxide particles can be applied to the second surface 2 b of the transparent substrate 2. Alternatively, a mixture containing a binder composition containing a polymer of an unsaturated compound and metal oxide particles may be applied to the second surface 2b of the transparent substrate 2 by a wet method. The mixture thus applied is formed on the second surface 2 b of the transparent substrate 2.

  When applying the mixture, the mixture may be applied directly to the second surface 2 b of the transparent substrate 2. Examples of the application method of the mixture include a wire bar coating method, a roll coating method, a spin coating method, and a curtain coating method.

  When the mixture includes an unsaturated compound and a polymerization initiator, the polymerization reaction of the unsaturated compound is started by applying a treatment according to the properties of the polymerization initiator, and the applied mixture is then transferred to the second surface of the transparent substrate 2. The anti-blocking layer 5 can be formed by curing on 2b.

  When the mixture includes a binder composition, the anti-blocking layer 5 can be formed by drying and curing the applied mixture on the second surface 2 b of the transparent substrate 2.

  Moreover, when the polymer of an unsaturated compound is contained in a thermoplastic resin, you may heat-knead a thermoplastic resin and a metal oxide particle, and may produce a mixture. Then, the mixture may be directly applied to the second surface 2b of the transparent substrate 2 by an application method such as a wire bar coating method, a roll coating method, a spin coating method, or a curtain coating method. The anti-blocking layer 5 can be formed by cooling and curing the mixture thus applied. Further, from the viewpoint of imparting anti-blocking properties, it is preferable that the mixture obtained by heat kneading is not formed into a sheet shape in advance.

<Transparent conductive film>
Next, the transparent conductive film 10 will be described with reference to FIG.

  The transparent conductive film 10 according to this embodiment includes the optical film 1. For this reason, the description of the optical film 1 can be referred for the structure of the code | symbol same as FIG.

  The transparent conductive film 10 can further include an inorganic layer 6 and a transparent conductive layer 7. In this case, the inorganic layer 6 may be provided on the opposite side of the second layer 4 from the transparent substrate 2. The transparent conductive layer 7 can be provided on the opposite side of the inorganic substrate 6 from the transparent substrate 2. In this case, the 2nd layer 4, the inorganic layer 6, and the transparent conductive layer 7 are good to be laminated | stacked in this order.

  The inorganic layer 6 is made of, for example, a metal oxide having electrical insulation. The metal oxide can include, but is not limited to, at least one compound selected from the group consisting of, for example, silicon dioxide and alumina.

  The inorganic layer 6 can improve the adhesion between the optical film 1 and the transparent conductive layer 7. Further, since the first layer 3, the second layer 4, and the inorganic layer 6 are laminated in this order, the transparent conductive layer 7 can be made particularly difficult to visually recognize. The inorganic layer 6 is formed in contact with the second layer 4.

  The inorganic layer 6 preferably has a thickness in the range of 10 to 30 nm. In this case, the planar view shape of the transparent conductive layer 7 can be made more difficult to visually recognize through the optical film 1. That is, when the transparent conductive film 10 provided with the transparent conductive layer 7 to which the planar view shape is given is observed, it is difficult to cause a hue difference between the region where the transparent conductive layer 7 is present and the region where the transparent conductive layer 7 is not present.

  The refractive index of the inorganic layer 6 is preferably in the range of 1.3 to 1.5. In this case, the planar view shape of the transparent conductive layer 7 can be made more difficult to visually recognize through the optical film 1. That is, when the transparent conductive film 10 provided with the transparent conductive layer 7 to which the planar view shape is given is observed, it is difficult to cause a hue difference between the region where the transparent conductive layer 7 is present and the region where the transparent conductive layer 7 is absent.

  In forming the inorganic layer 6, for example, a vapor deposition material containing a metal oxide can be formed into a thin film by any vapor deposition method. Examples of the vapor deposition method include a sputter vapor deposition method and a vacuum vapor deposition method.

  Moreover, the inorganic layer 6 may be formed from the composition containing a silicon alkoxide type compound, for example. In this case, a thin film inorganic layer 6 can be formed by applying a thin composition containing a silicon alkoxide compound to the second layer 4 by a wet process and curing the applied composition. When the composition is cured, a hydrolytic condensate can be formed from the silicon alkoxide compound in the composition. In this case, treatments such as heating, humidification, ultraviolet irradiation, and electron beam irradiation can be performed according to the properties of the silicon alkoxide compound.

  Examples of the silicon alkoxide compound include silicon alkoxides; and oligomers and polymers that are partial hydrolysates of silicon alkoxides. Examples of the silicon alkoxide include tetramethoxysilane, tetraethoxysilane, tetra-iso-propoxysilane, tetra-n-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, tetra-tert-butoxysilane, Tetrapentaethoxysilane, tetrapenta-iso-propoxysilane, tetrapenta-n-propoxysilane, tetrapenta-n-butoxysilane, tetrapenta-sec-butoxysilane, tetrapenta-tert-butoxysilane, methyltrimethoxysilane, methyltriethoxysilane, Methyltripropoxysilane, methyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethylethoxysilane, dimethylmethoxysilane, dimethyl Le propoxysilane, dimethyl-butoxy silane, methyl dimethoxy silane, methyl diethoxy silane, hexyl trimethoxy silane.

  Examples of the method for applying the composition include a wire bar coating method, a roll coating method, a spin coating method, and a curtain coating method.

  The transparent conductive layer 7 is preferably formed in contact with the inorganic layer 6. The transparent conductive layer 7 is made of a conductive metal oxide. The metal oxide can include at least one compound selected from the group of, for example, indium tin oxide (ITO), antimony-doped tin oxide (ATO), ZnO, and aluminum-doped zinc oxide (AZO), It is not limited to these. In particular, the transparent conductive layer 7 preferably contains indium tin oxide as its main component. The thickness of the transparent conductive layer 7 is in the range of 10 to 60 nm, for example.

  In forming the transparent conductive layer 7, for example, a conductive metal oxide is formed on the surface of the inorganic layer 6 by an arbitrary vapor deposition method. Examples of the vapor deposition method include a sputter vapor deposition method and a vacuum vapor deposition method. Moreover, the transparent conductive layer 7 has an arbitrary plan view shape according to the purpose. For example, the transparent conductive layer 7 can be given a plan view shape by etching the transparent conductive layer 7.

  Hereinafter, the present invention will be specifically described by way of examples.

First, an acrylic ultraviolet curable resin composition was applied to a norbornene resin film having a thickness of 50 μm (manufactured by Zeon Corporation, product number: COP ZF16-050) by a wire bar coating method. Subsequently, the applied acrylic ultraviolet curable resin composition was dried by heating at 60 ° C. for 1 minute, and the dried acrylic ultraviolet curable resin composition was irradiated with ultraviolet rays under the condition of 500 mJ / cm ² . . As a result, the acrylic ultraviolet curable resin composition was cured to prepare a test coating film having a thickness of 1 μm. And the test piece which has this test coating film and a norbornene-type resin film was used for the selection test of an acrylic type ultraviolet curable resin composition. The test piece was bent 180 ° so that both ends of the test piece overlapped, and it was visually confirmed whether or not the norbornene-based resin film was broken and the test coating film was cracked. In such a selection test, an acrylic ultraviolet curable resin composition in which breakage of the norbornene-based resin film and cracking of the test coating film did not occur was used in the following examples and comparative examples.

[Example 1]
As the transparent substrate, a norbornene resin film (manufactured by Nippon Zeon Co., Ltd., product number: COP ZF16-100) having a thickness of 100 μm was used. The retardation of the norbornene resin film is shown in the following table.

The norbornene-based resin film has a first surface in the thickness direction and a second surface located on the opposite side to the first surface. Of the first and second surfaces of the norbornene resin film, the first layer (hard coat layer) was formed on the first surface as follows. First, an ultraviolet curable mixture was prepared by mixing an acrylic ultraviolet curable resin composition and silica particles (average particle diameter 20 nm). In the stage of preparing this mixture, 35% by mass of silica particles was blended with respect to the total amount of the acrylic ultraviolet curable resin composition and the silica particles in terms of solid content. The mixture thus obtained was applied to the first surface of the norbornene-based resin film using a wire bar coater # 6. Subsequently, the applied mixture was dried by heating at 60 ° C. for 1 minute, and the dried mixture was irradiated with ultraviolet rays under the condition of 500 mJ / cm ² . Thereby, the mixture was cured to form a first layer having a thickness of 1.0 μm. The refractive index, thickness, and pencil hardness of this first layer are shown in the table below.

Next, a second layer (optical adjustment layer) was formed on the surface of the first layer as follows. First, an ultraviolet curable mixture was prepared by mixing an acrylic ultraviolet curable resin composition and zirconia particles (average particle size 20 nm). In the stage of preparing this mixture, 55% by mass of zirconia particles was blended with respect to the total amount of the acrylic ultraviolet curable resin composition and zirconia particles in terms of solid content. The mixture thus obtained was applied to the surface of the first layer using a wire bar coater # 3. Subsequently, the applied mixture was dried by heating at 100 ° C. for 1 minute, and the dried mixture was irradiated with ultraviolet rays under the condition of 500 mJ / cm ² . As a result, the mixture was cured to form a second layer having a thickness of 60 nm. The refractive index and thickness of this second layer are shown in the table below.

Next, an antiblocking layer was formed on the second surface of the norbornene resin film as follows. First, an ultraviolet curable mixture was prepared by mixing an acrylic ultraviolet curable resin composition and silica particles (average particle size 100 nm). In the step of preparing this mixture, 40% by mass of silica particles was blended with respect to the total amount of the acrylic ultraviolet curable resin composition and the silica particles in terms of solid content. The mixture thus obtained was applied to the second surface of the norbornene-based resin film using a wire bar coater # 6. Subsequently, the applied mixture was dried by heating at 60 ° C. for 1 minute, and the dried mixture was irradiated with ultraviolet rays under the condition of 500 mJ / cm ² . Thereby, the mixture was cured to form an anti-blocking layer (AB layer) having a thickness of 1.0 μm.

  Thus, an optical film was obtained.

[Example 2]
When forming the first layer, an optical film was obtained in the same manner and under the same conditions as in Example 1 except that the proportion of silica particles was 35% by mass.

[Example 3]
When forming the first layer, an optical film was obtained in the same manner and under the same conditions as in Example 1 except that the proportion of silica particles was 20% by mass.

[Example 4]
When the first layer was formed, an optical film was obtained by the same method and the same conditions as in Example 2 except that the average particle diameter was changed to silica particles having a particle size of 10 nm.

[Example 5]
When the first layer was formed, an optical film was obtained by the same method and the same conditions as in Example 2 except that the average particle diameter was changed to silica particles having a diameter of 100 nm.

[Example 6]
When forming the first layer, an optical film was obtained in the same manner and under the same conditions as in Example 2 except that the silica particles were changed to alumina particles (average particle diameter 20 nm).

[Comparative Example 1]
When forming the first layer, an optical film was obtained in the same manner and under the same conditions as in Example 1 except that the silica particles were not blended.

[Comparative Example 2]
When the first layer was formed, an optical film was obtained by the same method and the same conditions as in Example 2 except that the average particle diameter was changed to silica particles having a diameter of 120 nm.

[Comparative Example 3]
When forming the first layer, an optical film was obtained in the same manner and under the same conditions as in Example 1 except that the proportion of silica particles was 65% by mass.

[Evaluation test]
The optical film obtained in each example and comparative example was subjected to the following evaluation test. The results are shown in the table below.

(Haze measurement)
The haze of the optical film was measured using a haze meter (Nippon Denshoku Industries Co., Ltd., model number NDH2000).

(Total light transmittance measurement)
The total light transmittance of the optical film was measured using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., model number NDH2000).

(Pencil hardness)
The pencil hardness of the first layer was evaluated by a pencil hardness test in accordance with JIS K5400.

(Flexibility)
The optical film was folded 180 ° so that both ends of the optical film overlapped, and it was visually evaluated whether or not a crack occurred in the fold. In the table below, “A” indicates a case where no crack is generated in the fold, and “C” indicates a case where a crack is generated in the fold.

DESCRIPTION OF SYMBOLS 1 Optical film 2 Transparent substrate 2a 1st surface 2b 2nd surface 3 1st layer

Claims (7)

A transparent substrate containing a cycloolefin resin and having a first surface and a second surface located on the opposite side of the first surface;
A first layer provided on the first surface of the transparent substrate,
The first layer includes an acrylic resin and metal oxide particles,
The metal oxide particles have an average particle diameter in the range of 10 nm to 100 nm,
The content of the metal oxide particles is in the range of 20% by mass to 50% by mass with respect to the mass of the first layer.
Optical film. The thickness of the first layer is in the range of 500 nm to 10000 nm.
The optical film according to claim 1. The first layer has a pencil hardness higher than B in a pencil hardness test according to JIS K5400.
The optical film according to claim 1. The metal oxide particles in the first layer include at least one of silicon dioxide particles and alumina particles.
The optical film of any one of Claim 1 to 3. An anti-blocking layer provided on the second surface of the transparent substrate;
The anti-blocking layer includes metal oxide particles.
The optical film of any one of Claim 1 to 4. The refractive index of the first layer is in the range of 1.50 to 1.65,
A second layer provided on the opposite side of the first layer from the transparent substrate;
The second layer includes an acrylic resin and metal oxide particles,
The second layer has a thickness in the range of 10 nm to 100 nm and a refractive index in the range of more than 1.65 and not more than 1.95.
The optical film of any one of Claim 1 to 5. The optical film according to claim 6;
An inorganic layer provided on the side opposite to the transparent substrate of the second layer in the optical film;
A transparent conductive layer provided on the opposite side of the inorganic layer from the transparent substrate,
Transparent conductive film.

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