JP5494884B1 - Intermediate base film and touch panel sensor - Google Patents

Abstract

An intermediate substrate film and a touch panel sensor are provided that can suppress variations in color when viewed from various angles.
An intermediate substrate film for supporting a patterned conductive layer, the transparent substrate and a first high refractive index layer formed on one surface of the transparent substrate. 13 and a first low refractive index layer 14 formed on the first high refractive index layer 13 and having a refractive index lower than that of the first high refractive index layer 13, The normal direction of the surface of the film 10 is set to 0 °, and the intermediate substrate film 10 is irradiated with light from the first low refractive index layer 14 side while changing the incident angle every 5 degrees within the range of 0 ° to 75 °. When the a ^* value and b ^* value of the L ^* a ^* b ^* color system are determined from the reflected light in the regular reflection direction, the variation of the a ^* value is within 1.0, and b ^* An intermediate substrate film 10 having a value variation of 1.6 or less is provided.
[Selection] Figure 1

Description

  The present invention relates to an intermediate substrate film and a touch panel sensor.

  Today, touch panel devices are widely used as input means. The touch panel device includes a touch panel sensor, a control circuit that detects a contact position on the touch panel sensor, wiring, and FPC (flexible print base material). In many cases, the touch panel device is used together with the display device as an input means for various devices including a display device such as a liquid crystal display or a plasma display (for example, a ticket vending machine, an ATM device, a mobile phone, a game machine). Yes. In such a device, the touch panel sensor is disposed on the display surface of the display device, thereby enabling extremely direct input to the display device.

  Touch panel devices are classified into various types based on the principle of detecting a contact position (approach position) on a touch panel sensor. In recent years, a capacitive touch panel device has attracted attention because it is optically bright, has a design property, has a simple structure, and has excellent functionality. There are a surface type and a projection type in the electrostatic capacity method, but the projection type is attracting attention because it is suitable for multi-touch recognition (multi-point recognition).

  A touch panel sensor used for a projected capacitive touch panel includes an intermediate base film and a transparent conductive layer formed on the intermediate base film (see, for example, Patent Document 1). .

JP 2011-98563 A

  At present, the touch panel device is increasing in area, but as the touch panel device is increased in area, the screen size increases, so that the viewing angle tends to vary greatly depending on where the touch panel device is viewed. The intermediate substrate film of the touch panel sensor used in the touch panel device is designed on the assumption that it can be viewed from the front. Therefore, the touch panel device may not be able to cope with an increase in area.

  The present invention has been made to solve the above problems. That is, an object of the present invention is to provide an intermediate substrate film and a touch panel sensor that can suppress variations in color when viewed from various angles.

According to one aspect of the present invention, there is provided an intermediate substrate film for supporting a patterned conductive layer, which is laminated on a transparent substrate and one surface of the transparent substrate, and has a refractive index of 1. A first transparent layer having a thickness of 1 μm or more and a thickness of 1 μm or more, and a refractive index of 1.62 or more and 1.72 or less; A first high refractive index layer having a thickness of 20 nm to 80 nm and a first high refractive index layer laminated on the first high refractive index layer, having a refractive index of 1.44 to 1.54 and a thickness of 3 nm or more. A first low refractive index layer of 45 nm or less, wherein the normal direction of the surface of the intermediate base film is 0 °, and the incident angle is changed every 5 degrees within a range of 0 ° to 75 °. The intermediate base film is irradiated with light from the low refractive index layer side, and the reflected light in the respective regular reflection directions L ^* a ^* b ^* when seeking a ^* and b ^* values of the color system, is within the variation 1.0 of the a ^* value, and the variation of the b ^* value is within 1.6, intermediate A substrate film is provided.

  The intermediate substrate film is laminated on a surface of the transparent substrate opposite to the one surface, and has a refractive index of 1.47 or more and 1.57 or less and a film thickness of 1 μm or more. A transparent layer, a second high refractive index layer having a refractive index of 1.62 to 1.72 and a film thickness of 20 nm to 80 nm, and the second transparent layer, And a second low-refractive-index layer having a refractive index of 1.44 to 1.54 and a thickness of 3 to 45 nm.

  According to another aspect of the present invention, the touch panel includes the intermediate base film and a first conductive layer laminated and patterned on the first low refractive index layer of the intermediate base film. A sensor is provided.

  According to another aspect of the present invention, the intermediate base film, the first conductive layer laminated and patterned on the first low refractive index layer of the intermediate base film, and the intermediate group There is provided a touch panel sensor comprising a second conductive layer laminated on the second low refractive index layer of the material film and patterned.

  According to the intermediate base material fill and the touch panel sensor of one aspect of the present invention, it is possible to suppress variations in color when viewed from various angles.

It is a schematic block diagram of the intermediate | middle base film which concerns on 1st Embodiment. It is the schematic diagram which showed a mode that a ^* and b ^* in an intermediate base film were measured using a spectrophotometer. 1 is a schematic configuration diagram of a touch panel sensor according to a first embodiment. FIG. 4 is a plan view of a part of the first conductive layer shown in FIG. 3. FIG. 4 is a plan view of a part of a second conductive layer shown in FIG. 3. It is a schematic block diagram of the other touch panel sensor which concerns on 1st Embodiment. It is a schematic block diagram of the intermediate | middle base film which concerns on 2nd Embodiment. It is a schematic block diagram of the touchscreen sensor which concerns on 2nd Embodiment.

(First embodiment)
Hereinafter, an intermediate substrate film and a touch panel sensor according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of an intermediate substrate film according to the present embodiment, and FIG. 2 is a schematic diagram showing a state in which the spectral reflectance of the intermediate substrate film is measured with a spectral reflectance meter. In the present specification, terms such as “film”, “sheet”, and “plate” are not distinguished from each other only based on the difference in names. Therefore, for example, “film” is a concept including a member that can also be called a sheet or a plate. As a specific example, the “intermediate base film” includes members called “intermediate base sheet” and the like.

≪Intermediate substrate film≫
The intermediate substrate film is for supporting the patterned conductive layer. “Intermediate base film” means, for example, a base film used inside a device such as a touch panel rather than being used on the outermost surface of the device such as a touch panel when used in a device such as a touch panel. Means.

  An intermediate substrate film 10 shown in FIG. 1 is formed on a transparent substrate 11, a first transparent layer 12 formed on one surface 11A of the transparent substrate 11, and a first transparent layer 12. The first high-refractive index layer 13, the first low-refractive index layer 14 formed on the high-refractive index layer 13, and the surface 11 B of the transparent substrate 11 opposite to the one surface 11 A are formed. The second transparent layer 15 is provided.

  The intermediate base film 10 includes the second transparent layer 15, but may not include the second transparent layer 15. Moreover, the intermediate base film may include a second high refractive index layer or a second low refractive index layer on the second transparent layer. Specifically, as the intermediate substrate film, in addition to the intermediate substrate film 10 shown in FIG. 1, the first transparent layer, the first high refractive index layer, and the first layer on one surface of the transparent substrate. 1 is provided in this order, and an intermediate substrate film in which the second transparent layer is not provided on the other surface of the transparent substrate, and the first substrate on one surface of the transparent substrate. The transparent layer, the first high refractive index layer, and the first low refractive index layer are provided in this order, and the second transparent layer and the second high refractive index layer are provided on the other surface of the transparent substrate. An intermediate substrate film provided in this order, and a first transparent layer, a first high refractive index layer, and a first low refractive index layer are provided in this order on one surface of the transparent substrate, And an intermediate substrate film in which a second transparent layer, a second high refractive index layer, and a second low refractive index layer are provided in this order on the other surface of the transparent substrate. It may be.

In the intermediate base film 10, the normal direction of the surface of the intermediate base film 10 is set to 0 °, and the incident angle is changed every 5 degrees within a range of 0 ° to 75 °. When the intermediate substrate film 10 is irradiated with visible light and the a ^* value and b ^* value of the L ^* a ^* b ^* color system are determined from the reflected light in the respective regular reflection directions, variation in the a ^* value Is within 1.0, and b ^* value variation is within 1.6. “L ^* a ^* b ^* color system”, “a ^* ”, and “b ^* ” are based on JIS Z8729.

The a ^* value and the b ^* value are measured according to JIS Z8722, and can be specifically obtained using, for example, a known spectrophotometer. The spectrophotometer 100 shown in FIG. 3 includes a light source 101 that can move within a range of 0 ° to 75 °, and a detection that moves in synchronization with the movement of the light source so that reflected light in the regular reflection direction can be received. Instrument 102. The moving angle of the light source 101 is 0 ° in the normal direction N of the intermediate base film 10. The intermediate base film 10 is irradiated with light from the light source 101, the reflected light in the regular reflection direction is received by the detector 102, and the a ^* value and the b ^* value are obtained from the reflected light received by the detector 102. it can. As a spectrophotometer, JASCO Corporation absolute reflectance measuring device VAR-7010, ultraviolet visible near-infrared spectrophotometer V-7100, etc. are mentioned. Examples of the light source include a tungsten halogen (WI) lamp alone or a combination of a deuterium (D2) lamp and a tungsten halogen (WI) lamp. In this measurement, as the incident angle increases, the difference in reflectance between s-polarized light and p-polarized light increases. Therefore, it is preferable to use a polarizer whose transmission axis is inclined by 45 ° for accurate measurement.

variation in a ^* and b ^* values is by the spectrophotometer, determine the a ^* and b ^* values at each incident angle by calculating the absolute value of the difference between the maximum value and the minimum value, determining Can do. The variation in a ^* value is preferably within 0.4, and the variation in b ^* value is preferably within 1.55.

And the reflected light of an angle determined the a ^* and b ^* values, the color difference Delta] E ^* ab between the reflected light of the other angle, determined the a ^* value and b ^* value is preferably 5 or less . “ΔE ^* ab” conforms to JIS Z8730.

<Transparent substrate>
The transparent substrate 11 is not particularly limited as long as it has optical transparency. For example, a polyolefin substrate, a polycarbonate substrate, a polyacrylate substrate, a polyester substrate, an aromatic polyether ketone substrate, a polyether sulfone can be used. A base material or a polyamide base material is mentioned.

  As a polyolefin base material, the base material which uses at least 1 sort (s), such as polyethylene, a polypropylene, a cyclic polyolefin base material, for example is mentioned. Examples of the cyclic polyolefin base material include those having a norbornene skeleton.

  Examples of the polycarbonate substrate include aromatic polycarbonate substrates based on bisphenols (bisphenol A and the like), aliphatic polycarbonate substrates such as diethylene glycol bisallyl carbonate, and the like.

  Examples of the polyacrylate substrate include poly (meth) methyl acrylate substrate, poly (meth) ethyl acrylate substrate, (meth) methyl acrylate- (meth) butyl acrylate copolymer substrate, and the like. It is done.

  As a polyester base material, the base material which uses at least 1 sort (s) of a polyethylene terephthalate (PET), a polypropylene terephthalate, a polybutylene terephthalate, and a polyethylene naphthalate (PEN) as an example is mentioned.

  Examples of the aromatic polyether ketone base material include a polyether ether ketone (PEEK) base material.

  The thickness of the transparent substrate 11 is not particularly limited, but can be 5 μm or more and 300 μm or less. The lower limit of the thickness of the transparent substrate 11 is preferably 25 μm or more, more preferably 50 μm or more from the viewpoint of handling properties. . The upper limit of the thickness of the transparent substrate 11 is preferably 250 m or less from the viewpoint of thinning.

  In order to improve adhesion, the surface of the transparent substrate 11 may be preliminarily coated with a coating called an anchor agent or a primer in addition to physical treatment such as corona discharge treatment and oxidation treatment. Examples of the anchor agent and primer agent include polyurethane resin, polyester resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate copolymer, acrylic resin, polyvinyl alcohol resin, polyvinyl acetal resin, ethylene A copolymer of ethylene and vinyl acetate or acrylic acid, a copolymer of ethylene and styrene and / or butadiene, a thermoplastic resin such as an olefin resin and / or a modified resin thereof, a polymer of a photopolymerizable compound, and It is possible to use at least one of thermosetting resins such as epoxy resins.

<First transparent layer and second transparent layer>
The first transparent layer 12 and the second transparent layer 15 in the present embodiment preferably have a hard coat property. When the first transparent layer 12 and the second transparent layer 15 have hard coat properties, the first transparent layer 12 and the second transparent layer 15 have a pencil hardness defined by JIS K5600-5-4 (1999). It has a hardness of “H” or higher in the test (4.9 N load). By setting the pencil hardness to “H” or higher, the hardness of the first transparent layer 12 can be sufficiently reflected on the surface of the first low refractive index layer 14 and the durability can be improved. The upper limit of the pencil hardness on the surface of the first transparent layer 12 is about 4H from the viewpoint of adhesion to the first high refractive index layer 13 formed on the first transparent layer 12, toughness and prevention of curling. It is preferable that Since the touch panel sensor is repeatedly pressed and requires high adhesion and toughness, the upper limit of the pencil hardness of the first transparent layer 12 is set to 4H, so that the intermediate substrate film 10 is incorporated into the touch panel sensor and used. When it does, a remarkable effect can be demonstrated. In addition, when the conductive layer is formed on the first low refractive index layer 14, the intermediate base film is heated, and this heating causes oligomers to precipitate from the transparent base and raises the haze of the intermediate base film. Although a subject may arise, the 1st transparent layer 12 and the 2nd transparent layer 15 can function as a layer which suppresses precipitation of an oligomer.

  The refractive index of the first transparent layer 12 is 1.47 or more and 1.57 or less. The lower limit of the refractive index of the first transparent layer 12 is preferably 1.50 or more, and the upper limit of the refractive index of the first transparent layer 12 is preferably 1.54 or less. The refractive index of the second transparent layer 15 is preferably in the same range as that of the first transparent layer 12. However, the refractive index of the second transparent layer 15 does not necessarily match the refractive index of the first transparent layer 12.

  The refractive indexes of the first transparent layer 12 and the second refractive index layer 15 can be measured with an Abbe refractometer (NAR-4T manufactured by Atago Co., Ltd.) or an ellipsometer after forming a single layer. Moreover, as a method of measuring the refractive index after becoming the intermediate substrate film 10, the first transparent layer 12 and the second refractive index layer 15 are each scraped off with a cutter or the like to prepare a powder sample, and JIS Becke method according to K7142 (2008) B method (for powder or granular transparent material) (using a Cargill reagent having a known refractive index, placing the powdered sample on a glass slide, etc., and placing the reagent on the sample) Drop the sample and immerse the sample in the reagent.Observe the state of the sample by microscopic observation, and the bright line generated in the sample outline due to the difference in the refractive index between the sample and the reagent; Can be used.

  The film thickness of the first transparent layer 12 is 1.0 μm or more. If the thickness of the 1st transparent layer 12 is 1.0 micrometer or more, desired hardness can be obtained. The film thickness of the first transparent layer 12 can be measured by cross-sectional microscope observation. The lower limit of the thickness of the first transparent layer is more preferably 1.5 μm or more, the upper limit is more preferably 7.0 μm or less, and the thickness of the first transparent layer 12 is 2.0 μm or more and 5.0 μm. More preferably, it is as follows. The film thickness of the second transparent layer 15 is preferably in the same range as the film thickness of the first transparent layer 12. However, the film thickness of the second transparent layer 15 does not necessarily need to match the film thickness of the first transparent layer 15.

  The 1st transparent layer 12 and the 2nd transparent layer 15 can be constituted from resin, for example. The resin contains a polymerized product (crosslinked product) of a photopolymerizable compound. The resin may contain a solvent-drying resin or a thermosetting resin in addition to a polymer (cross-linked product) of a photopolymerizable compound. The photopolymerizable compound has at least one photopolymerizable functional group. In the present specification, the “photopolymerizable functional group” is a functional group capable of undergoing a polymerization reaction by light irradiation. Examples of the photopolymerizable functional group include ethylenic double bonds such as a (meth) acryloyl group, a vinyl group, and an allyl group. The “(meth) acryloyl group” means to include both “acryloyl group” and “methacryloyl group”. The light irradiated when polymerizing the photopolymerizable compound includes visible light and ionizing radiation such as ultraviolet rays, X-rays, electron beams, α rays, β rays, and γ rays.

  Examples of the photopolymerizable compound include a photopolymerizable monomer, a photopolymerizable oligomer, and a photopolymerizable polymer, and these can be appropriately adjusted and used. As the photopolymerizable compound, a combination of a photopolymerizable monomer and a photopolymerizable oligomer or photopolymerizable polymer is preferable.

Photopolymerizable monomer The photopolymerizable monomer has a weight average molecular weight of less than 1000. The photopolymerizable monomer is preferably a polyfunctional monomer having two or more photopolymerizable functional groups (that is, bifunctional). In this specification, the “weight average molecular weight” is a value obtained by dissolving in a solvent such as tetrahydrofuran (THF) and converting to polystyrene by a conventionally known gel permeation chromatography (GPC) method.

  Examples of the bifunctional or higher monomer include trimethylolpropane tri (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, and pentaerythritol tri (meth). Acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditri Methylolpropane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, tripentaerythritol octa (meth) acrylate, Lapentaerythritol deca (meth) acrylate, isocyanuric acid tri (meth) acrylate, isocyanuric acid di (meth) acrylate, polyester tri (meth) acrylate, polyester di (meth) acrylate, bisphenol di (meth) acrylate, diglycerin tetra ( (Meth) acrylate, adamantyl di (meth) acrylate, isoboronyl di (meth) acrylate, dicyclopentane di (meth) acrylate, tricyclodecane di (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, and these are PO, EO And the like modified.

  Among these, from the viewpoint of obtaining a hard coat layer having high hardness, pentaerythritol triacrylate (PETA), dipentaerythritol hexaacrylate (DPHA), pentaerythritol tetraacrylate (PETTA), dipentaerythritol pentaacrylate (DPPA) and the like are preferable. .

The photopolymerizable oligomer The photopolymerizable oligomer has a weight average molecular weight of 1,000 or more and less than 10,000. The photopolymerizable oligomer is preferably a bifunctional or higher polyfunctional oligomer. Polyfunctional oligomers include polyester (meth) acrylate, urethane (meth) acrylate, polyester-urethane (meth) acrylate, polyether (meth) acrylate, polyol (meth) acrylate, melamine (meth) acrylate, and isocyanurate (meth). Examples include acrylate and epoxy (meth) acrylate.

Photopolymerizable polymer The photopolymerizable polymer has a weight average molecular weight of 10,000 or more, and the weight average molecular weight is preferably 10,000 or more and 80,000 or less, and more preferably 10,000 or more and 40,000 or less. When the weight average molecular weight exceeds 80000, the viscosity is high, so that the coating suitability is lowered, and the appearance of the obtained optical film may be deteriorated. Examples of the polyfunctional polymer include urethane (meth) acrylate, isocyanurate (meth) acrylate, polyester-urethane (meth) acrylate, and epoxy (meth) acrylate.

  When polymerizing (crosslinking) the photopolymerizable compound, a polymerization initiator or the like may be used. The polymerization initiator is a component that is decomposed by light irradiation to generate radicals to initiate or advance polymerization (crosslinking) of the photopolymerizable compound.

  The polymerization initiator is not particularly limited as long as it can release a substance that initiates radical polymerization by light irradiation. The polymerization initiator is not particularly limited, and known ones can be used. Specific examples include, for example, acetophenones, benzophenones, Michler benzoylbenzoate, α-amyloxime ester, thioxanthones, propiophenone. , Benzyls, benzoins, acylphosphine oxides. In addition, it is preferable to use a mixture of photosensitizers, and specific examples thereof include n-butylamine, triethylamine, poly-n-butylphosphine, and the like.

  As the polymerization initiator, when the binder resin is a resin system having a radically polymerizable unsaturated group, it is preferable to use acetophenones, benzophenones, thioxanthones, benzoin, benzoin methyl ether or the like alone or in combination. .

  The solvent-drying resin is a resin that forms a film only by drying a solvent added to adjust the solid content during coating, such as a thermoplastic resin. When the solvent-drying type resin is added, film defects on the coating surface of the coating liquid can be effectively prevented when the antiglare layer 12 is formed. It does not specifically limit as solvent dry type resin, Generally, a thermoplastic resin can be used.

  Examples of thermoplastic resins include styrene resins, (meth) acrylic resins, vinyl acetate resins, vinyl ether resins, halogen-containing resins, alicyclic olefin resins, polycarbonate resins, polyester resins, polyamide resins. , Cellulose derivatives, silicone resins and rubbers or elastomers.

  The thermoplastic resin is preferably amorphous and soluble in an organic solvent (particularly a common solvent capable of dissolving a plurality of polymers and curable compounds). In particular, from the viewpoint of transparency and weather resistance, styrene resins, (meth) acrylic resins, alicyclic olefin resins, polyester resins, cellulose derivatives (cellulose esters, etc.) and the like are preferable.

  The thermosetting resin is not particularly limited. For example, phenol resin, urea resin, diallyl phthalate resin, melamine resin, guanamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, aminoalkyd resin, melamine-urea cocondensation Examples thereof include resins, silicon resins, polysiloxane resins, and the like.

  The 1st transparent layer 12 and the 2nd transparent layer 15 apply | coat the composition for transparent layers containing the said photopolymerizable compound to the surface of the transparent base material 11, and after making it dry, a coating-form transparent layer The composition can be formed by irradiating the composition for ultraviolet rays with light such as ultraviolet rays to polymerize (crosslink) the photopolymerizable compound.

  In addition to the photopolymerizable compound, a solvent and a polymerization initiator may be added to the transparent layer composition as necessary. Furthermore, according to the purpose of increasing the hardness of the first transparent layer, suppressing curing shrinkage, controlling the refractive index, and the like, the transparent layer composition includes conventionally known dispersants, surfactants, and antistatic agents. Agent, silane coupling agent, thickener, anti-coloring agent, coloring agent (pigment, dye), antifoaming agent, leveling agent, flame retardant, UV absorber, adhesion-imparting agent, polymerization inhibitor, antioxidant, surface A modifier, a lubricant, etc. may be added.

  Examples of the method for applying the transparent layer composition include known coating methods such as spin coating, dipping, spraying, slide coating, bar coating, roll coating, gravure coating, and die coating.

  When ultraviolet rays are used as the light for curing the transparent layer composition, ultraviolet rays emitted from an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a xenon arc, a metal halide lamp, or the like can be used. Moreover, as a wavelength of an ultraviolet-ray, the wavelength range of 190-380 nm can be used. Specific examples of the electron beam source include various electron beam accelerators such as a cockcroft-wald type, a bandegraft type, a resonant transformer type, an insulated core transformer type, a linear type, a dynamitron type, and a high frequency type.

<First high refractive index layer>
The first high refractive index layer 13 is a layer having a refractive index higher than that of the first transparent layer 12. Specifically, the refractive index of the first high refractive index layer 13 is 1.62 or more and 1.72 or less. The lower limit of the refractive index of the first high refractive index layer 13 is preferably 1.65 or more, and the upper limit of the refractive index of the first high refractive index layer 13 is preferably 1.69 or less. The refractive index of the first high refractive index layer 13 can be measured by the same method as the refractive index of the first transparent layer 12. The refractive index difference between the first transparent layer 12 and the first high refractive index layer 13 is preferably 0.05 or more and 0.15 or less from the viewpoint of further suppressing variation in color.

  The film thickness of the first high refractive index layer 13 is 20 nm or more and 80 nm or less. The lower limit of the film thickness of the first high refractive index layer 13 is preferably 40 nm or more, and the upper limit of the refractive index of the first high refractive index layer 13 is preferably 60 nm or less.

  The first high-refractive index layer 13 and the first low-refractive index layer 14 reduce the difference in light transmittance and reflectance between the region where the conductive layer is provided and the region where the conductive layer is not provided. It can function as an index matching layer.

  The first high refractive index layer 13 is not particularly limited as long as it has the above refractive index and the above film thickness. For example, the first high refractive index layer 13 includes, for example, high refractive index particles and a binder resin. It can consist of.

Examples of the high refractive index particles include metal oxide fine particles. Specific examples of the metal oxide fine particles include titanium oxide (TiO ₂ , refractive index: 2.3 to 2.7), niobium oxide (Nb ₂ O ₅ , refractive index: 2.33), and zirconium oxide. (ZrO ₂ , refractive index: 2.10), antimony oxide (Sb ₂ O ₅ , refractive index: 2.04), tin oxide (SnO ₂ , refractive index: 2.00), tin-doped indium oxide (ITO, refractive index) : 1.95 to 2.00), cerium oxide (CeO _2, refractive index: 1.95), aluminum-doped zinc oxide (AZO, refractive index: 1.90 to 2.00), gallium-doped zinc oxide (GZO, Refractive index: 1.90 to 2.00), zinc antimonate (ZnSb ₂ O ₆ , refractive index: 1.90 to 2.00), zinc oxide (ZnO, refractive index: 1.90), yttrium oxide (Y ₂ O _3, the refractive index: 1 87), antimony-doped tin oxide (ATO, refractive index: 1.75 to 1.85), phosphorus-doped tin oxide (PTO, refractive index: 1.75 to 1.85), and the like. Among these, zirconium oxide is preferable from the viewpoint of high refractive index and cost.

  The binder resin contained in the first high refractive index layer 13 is not particularly limited, and a thermoplastic resin can be used. From the viewpoint of increasing the surface hardness, a thermosetting resin or a photopolymerizable compound, etc. Of these, a polymer (cross-linked product) is preferable, and a photopolymerizable compound is more preferable.

  Examples of the thermosetting resin include resins such as acrylic resin, urethane resin, phenol resin, urea melamine resin, epoxy resin, unsaturated polyester resin, and silicone resin. When curing the thermosetting resin, a curing agent may be used.

  Although it does not specifically limit as a photopolymerizable compound, A photopolymerizable monomer, an oligomer, and a polymer can be used. Examples of the monofunctional photopolymerizable monomer include ethyl (meth) acrylate, ethylhexyl (meth) acrylate, styrene, methylstyrene, and N-vinylpyrrolidone. Examples of the bifunctional or higher photopolymerizable monomer include polymethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, and pentaerythritol tris. (Meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) Examples include acrylates, compounds obtained by modifying these compounds with ethylene oxide, polyethylene oxide, and the like.

  In addition, these compounds may have a refractive index adjusted to be high by introducing an aromatic ring, a halogen atom other than fluorine, sulfur, nitrogen, phosphorus atoms, or the like. In addition to the above compounds, relatively low molecular weight polyester resins having unsaturated double bonds, polyether resins, acrylic resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, etc. Can also be used. When the photopolymerizable compound is polymerized (crosslinked), the polymerization initiator described in the columns of the first transparent layer and the second transparent layer may be used.

  The first high refractive index layer 13 can be formed by, for example, a method similar to the method for forming the first transparent layer 12. Specifically, first, the first high refractive index layer composition containing at least the high refractive index fine particles and the photopolymerizable compound is applied to the surface of the first transparent layer 12. Next, the coating film-like first composition for a high refractive index layer is dried. Thereafter, the first high refractive index layer 13 can be formed by irradiating the coating composition for transparent layer with light such as ultraviolet rays to polymerize (crosslink) the photopolymerizable compound.

<First low refractive index layer>
The first low refractive index layer 14 is a layer having a refractive index lower than that of the first high refractive index layer 13. The first low refractive index layer only needs to have a refractive index lower than that of the first high refractive index layer, and does not necessarily need to have a refractive index lower than that of the first transparent layer. . Specifically, the refractive index of the first low refractive index layer 14 is 1.44 or more and 1.54 or less. The lower limit of the refractive index of the first low refractive index layer 14 is preferably 1.47 or more, and the upper limit of the refractive index of the first low refractive index layer 14 is preferably 1.51 or less. The refractive index of the first low refractive index layer 14 can be measured by the same method as the refractive index of the first transparent layer 12. The refractive index difference between the first high-refractive index layer 13 and the first low-refractive index layer 14 is preferably 0.10 or more and 0.22 or less from the viewpoint of further suppressing variation in color.

  The film thickness of the first low refractive index layer 14 is not less than 3 nm and not more than 45 nm. The lower limit of the film thickness of the first low refractive index layer 14 is preferably 5 nm or more, and the upper limit of the film thickness of the first low refractive index layer 14 is preferably 25 nm or less.

  The first low refractive index layer 14 is not particularly limited as long as the first low refractive index layer 14 has the above refractive index and the above film thickness, but the first low refractive index layer 14 includes, for example, low refractive index particles and a binder resin. Or a low refractive index resin.

  Examples of the low refractive index particles include solid or hollow particles made of silica or magnesium fluoride. Among these, hollow silica particles are preferable, and such hollow silica particles can be produced, for example, by the production method described in Examples of JP-A-2005-099778.

  As the low refractive index fine particles, it is preferable to use reactive silica fine particles having a reactive functional group on the silica surface. As the reactive functional group, a photopolymerizable functional group is preferable. Such reactive silica fine particles can be prepared by surface-treating silica fine particles with a silane coupling agent or the like. As a method of treating the surface of the silica fine particles with a silane coupling agent, a dry method in which the silane coupling agent is sprayed on the silica fine particles, or a wet method in which the silica fine particles are dispersed in a solvent and then reacted by adding the silane coupling agent. Etc.

  Examples of the binder resin that constitutes the first low refractive index layer 14 include the same binder resin that constitutes the first high refractive index layer 13. However, a resin having a low refractive index such as a resin in which a fluorine atom is introduced or an organopolysiloxane may be mixed in the binder resin.

  Examples of the low refractive index resin include a resin into which a fluorine atom is introduced and a resin having a low refractive index such as organopolysiloxane.

  The first low refractive index layer 14 can be formed by, for example, a method similar to the method for forming the first transparent layer 12. Specifically, first, the first low refractive index layer composition containing at least the low refractive index fine particles and the photopolymerizable compound is applied to the surface of the first high refractive index layer 13. Next, the coating film-like first composition for a low refractive index layer is dried. Thereafter, the first low-refractive-index layer 14 is formed by irradiating light such as ultraviolet rays to the coating-like first low-refractive-index layer composition to polymerize (crosslink) the photopolymerizable compound. Can do.

Conventionally, the refractive index and film thickness of the low refractive index layer, etc. of the intermediate substrate film are mainly the difference between the reflectance of the intermediate substrate film and the reflectance of the conductive layer laminated on the intermediate substrate film (reflection). It has been determined from the viewpoint of reducing the (rate difference), and no attention has been paid to variations in color when the intermediate base film is viewed from various angles. On the other hand, the human eye can easily perceive the color change more than the reflectance difference, and in order to reduce the reflectance difference between the intermediate base film and the conductive layer, the high refractive index layer and the low refractive index layer When the refractive index difference is increased, the color variation tends to increase. As a result of extensive research conducted by the present inventors, it has been found that variation in tint can be suppressed by adjusting the a ^* value and b ^* value of the intermediate substrate film. Specifically, the normal direction of the surface of the intermediate substrate film is set to 0 °, and the incident angle is changed every 5 degrees within the range of 0 ° to 75 °, while the intermediate substrate film is viewed from the first low refractive index layer side. When the a ^* value and b ^* value of the L ^* a ^* b ^* color system are calculated from the reflected light in each regular reflection direction, the variation of the a ^* value is within 1.0. If the variation in b ^* value is within 1.6, it was not recognized that the tint was dispersed even when the observer viewed the intermediate substrate film from various directions. I found it from the experiment. Further, on the transparent base material, the first transparent layer having a refractive index of 1.47 or more and 1.57 or less and a film thickness of 1 μm or more, and a refractive index of 1.62 or more and 1.72 or less, And a first high refractive index layer having a thickness of 20 nm to 80 nm and a first low refractive index layer having a refractive index of 1.44 to 1.54 and a thickness of 3 nm to 45 nm. When laminated in this order, it was found that the variation in the a ^* value in the intermediate base film can be within 1.0 and the variation in the b ^* value can be within 1.6. According to the present embodiment, the normal direction of the surface of the intermediate base film 10 is set to 0 °, and the incident angle is changed every 5 degrees within the range of 0 ° to 75 ° from the first low refractive index layer 14 side. When the intermediate substrate film 10 is irradiated with light and the a ^* value and b ^* value of the L ^* a ^* b ^* color system are determined from the reflected light in the respective regular reflection directions, the variation of the a ^* value is 1. Since it is within 0.0 and the variation in b ^* value is within 1.6, variation in color when the base film 10 is viewed from various angles can be suppressed. The first transparent layer 12 having the refractive index and the film thickness, the first high refractive index layer 13 having the refractive index and the film thickness, and the first low refractive index layer 14 having the refractive index and the film thickness. In the intermediate substrate film 10 having the above, the difference in reflectance with the conductive layer is within an allowable range, but the difference in reflectance with the conductive layer is larger than that in the conventional intermediate substrate film, so that From the viewpoint of reducing the difference in reflectance between the intermediate base film and the conductive layer, it cannot be employed. Therefore, the refractive index and film thickness of the first transparent layer 12, the first high refractive index layer 13, and the first low refractive index layer 14 are within the above range, and the a ^* value and the b ^* value are within the above range. It can be said that the above-mentioned effect produced by the inside is a remarkable effect exceeding the range that can be predicted in light of the technical level of the conventional intermediate base film.

≪Touch panel sensor≫
The intermediate base film 10 can be used by being incorporated into a touch panel sensor, for example. 3 is a schematic configuration diagram of a touch panel sensor incorporating the intermediate substrate film according to the present embodiment, FIG. 4 is a plan view of a part of the first conductive layer shown in FIG. 3, and FIG. 4 is a plan view of a part of a second conductive layer shown in FIG. FIG. 6 is a schematic configuration diagram of another touch panel sensor incorporating the intermediate substrate film according to the present embodiment.

  The touch panel sensor 20 shown in FIG. 3 has a structure in which a first conductive film 30 and a second conductive film 40 are laminated. The first conductive film 30 is formed on the intermediate base film 10, the first conductive layer 31 that is supported and patterned by the intermediate base film 10, and the intermediate base film 10 and the first conductive layer 31. And a first transparent adhesive layer 32 provided. The second conductive film 40 is formed on the intermediate base film 10, the second conductive layer 41 supported and patterned by the intermediate base film 10, and the intermediate base film 10 and the second conductive layer 41. And a second transparent adhesive layer 42 provided.

  The first conductive layer 31 and the second conductive layer 41 are not particularly limited as long as they are patterned in a desired shape and have conductivity. The first conductive layer 31 and the second conductive layer 41 are connected to a terminal portion (not shown) through an extraction pattern (not shown). Although the shape of the 1st conductive layer 31 and the 2nd conductive layer 41 is not specifically limited, A square shape, a rhombus shape, or stripe shape is mentioned. The first conductive layer 31 and the second conductive layer 41 have a square shape as shown in FIGS.

  Since the first conductive layer 31 functions as an electrode in the X direction in the touch panel sensor 20, the pattern shape forming the first conductive layer 31 is electrically connected in the horizontal direction as shown in FIG. Has been. The first conductive layer 31 is provided on the first low refractive index layer 14 of the intermediate base film 10 that constitutes the first conductive film 30.

  Since the second conductive layer 41 functions as an electrode in the Y direction in the touch panel sensor 20, the pattern shape constituting the second conductive layer 41 is electrically connected in the vertical direction as shown in FIG. Has been. The second conductive layer 41 is provided on the first low refractive index layer 14 of the intermediate base film 10 constituting the second conductive film 40.

  The first conductive layer 31 is arranged on the viewer side with respect to the intermediate base film 10 constituting the first conductive film 30, and the second conductive layer 41 includes the second conductive film 40. It arrange | positions at the observer side rather than the intermediate | middle base film 10 to comprise. That is, the second conductive layer 41 is disposed between the intermediate base film 10 constituting the first conductive film 30 and the intermediate base film 10 constituting the second conductive film 40. The first conductive film 30 and the second conductive film 40 are attached by a second transparent adhesive layer 42.

  The intermediate base film 10 may be incorporated in a touch panel sensor according to another aspect. The touch panel sensor 50 shown in FIG. 6 includes an intermediate base film 10, a first conductive layer 51 and a second conductive layer 52 that are supported and patterned by the intermediate base film 10, and a first conductive layer 51. And a transparent adhesive layer 53 that fixes the second conductive layer 52 to each other. The second conductive layer 51 is formed on one surface of the glass plate 54, and the second conductive layer 51 and the glass plate 54 are integrated.

  The first conductive layer 51 functions as an electrode in the X direction in the touch panel sensor 30, and has a pattern shape similar to that of the first conductive layer 31. The second conductive layer 52 functions as an electrode in the Y direction in the touch panel sensor 30 and has a pattern shape similar to that of the second conductive layer 41. Both the first conductive layer 51 and the second conductive layer 52 are provided on the first low refractive index layer 14 of the intermediate base film 10.

<First conductive layer and second conductive layer>
The first conductive layers 31 and 51 and the second conductive layers 41 and 52 are preferably transparent conductive layers made of a transparent conductive material, for example. Transparent conductive materials include tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO), zinc oxide, indium oxide (In ₂ O ₃ ), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), oxidation Examples thereof include metal oxides such as tin, zinc oxide-tin oxide, indium oxide-tin oxide, and zinc oxide-indium oxide-magnesium oxide. The first conductive layers 31 and 51 and the second conductive layers 41 and 52 are not limited to transparent conductive layers, and may be, for example, patterned metal mesh layers. The metal mesh layer is preferably black-coated with nickel or copper oxide. This black coating can suppress metal reflection of the metal mesh layer.

  The formation method of the first conductive layers 31 and 51 and the second conductive layers 41 and 52 is not particularly limited, and a sputtering method, a vacuum deposition method, an ion plating method, a CVD method, a coating method, a printing method, or the like can be used. Can be used. As a method of patterning the first conductive layers 31 and 51 and the second conductive layers 41 and 52, for example, a photolithography method can be given.

<Transparent adhesive layer>
Examples of the first transparent adhesive layer 32, the second transparent adhesive layer 42, and the adhesive layer 53 include known pressure-sensitive adhesive layers and adhesive sheets.

(Second Embodiment)
Hereinafter, an intermediate substrate film and a touch panel sensor according to a second embodiment of the present invention will be described with reference to the drawings. FIG. 7 is a schematic configuration diagram of an intermediate substrate film according to the present embodiment. In addition, in this embodiment, the member to which the same code | symbol as the member demonstrated in 1st Embodiment is attached | subjected means that it is the same member as the member demonstrated in 1st Embodiment, and The contents overlapping with those of the first embodiment are omitted unless otherwise specified.

  The intermediate substrate film 60 shown in FIG. 7 is formed on the transparent substrate 11, the first transparent layer 12 formed on one surface 11A of the transparent substrate 11, and the first transparent layer 12. The first high refractive index layer 13, the first low refractive index layer 14 formed on the first high refractive index layer 13, and the surface 11 </ b> B opposite to the one surface 11 </ b> A of the transparent substrate 11. The second transparent layer 15 formed thereon, the second high refractive index layer 61 formed on the second transparent layer 15, and the second high refractive index layer 61 formed on the second high refractive index layer 61. And a low refractive index layer 62. That is, the intermediate base film 60 is obtained by forming the second high refractive index layer 61 and the second low refractive index layer 62 on the second transparent layer 15 of the intermediate base film 10.

  The second high refractive index layer 61 preferably has the same refractive index and film thickness as the first high refractive index layer 13. That is, the second high refractive index layer 61 preferably has a refractive index of 1.62 to 1.72 and a film thickness of 20 nm to 80 nm. Further, the second high refractive index layer 61 can be made of the same material as that of the first high refractive index layer 13.

  The second low refractive index layer 62 preferably has the same refractive index and film thickness as the first low refractive index layer 14. That is, the second low refractive index layer 62 preferably has a refractive index of 1.44 to 1.54 and a film thickness of 3 nm to 45 nm. The second low refractive index layer 62 can be made of the same material as the first low refractive index layer 13.

In the intermediate base film 60, the normal direction of the surface of the intermediate base film 60 is set to 0 °, and the incident angle is changed every 5 degrees within the range of 0 ° to 75 °, and the first low refractive index layer 14 side When the intermediate substrate film 60 is irradiated with visible light and the a ^* value and b ^* value of the L ^* a ^* b ^* color system are determined from the reflected light in the respective regular reflection directions, variation in the a ^* value Is within 1.0, and b ^* value variation is within 1.6. The variation in a ^* value is preferably within 0.4, and the variation in b ^* value is preferably within 1.55.

According to this embodiment, the first transparent layer 12 having a refractive index of 1.47 or more and 1.57 or less and a film thickness of 1 μm or more on the transparent substrate 11 and a refractive index of 1.62 or more. A first high-refractive-index layer 13 having a thickness of 20 to 80 nm and a refractive index of 1.44 to 1.54 and a thickness of 3 to 45 nm; Since the low refractive index layer 14 of 1 is laminated in this order, the normal direction of the surface of the intermediate base film 60 is set to 0 °, and the incident angle is changed every 5 degrees within the range of 0 ° to 75 °. The intermediate base film 60 is irradiated with light from the first low refractive index layer 14 side, and the a ^* value and b ^* value of the L ^* a ^* b ^* color system are obtained from the reflected light in the respective regular reflection directions. when in the variation of the a ^* value in the intermediate base film 60 is 1.0 less and a variation in the b ^* value It can be within .6. Thereby, the dispersion | variation in the tint at the time of visually recognizing from various angles can be suppressed.

In the intermediate base film 60, the normal direction of the surface of the intermediate base film 60 is set to 0 °, and the incident angle is changed every 5 degrees within the range of 0 ° to 75 °. When the intermediate substrate film 60 is irradiated with visible light and the a ^* value and b ^* value of the L ^* a ^* b ^* color system are determined from the reflected light in the respective regular reflection directions, variation in the a ^* value Is preferably within 1.0 and b ^* value variation is preferably within 1.6. The variation in a ^* value is preferably within 0.4, and the variation in b ^* value is preferably within 1.55. In this case, the variation in the a ^* value is within 1.0 and the variation in the b ^* value is within 1.6 on both surfaces of the base film 60. Variations in tint when viewed from an angle can be suppressed.

≪Touch panel sensor≫
The intermediate base film 60 can be used by being incorporated into a touch panel sensor, for example. FIG. 8 is a schematic configuration diagram of a touch panel sensor incorporating the intermediate substrate film according to the present embodiment.

  The touch panel sensor 70 shown in FIG. 8 includes an intermediate base film 60, a first conductive layer 71 and a second conductive layer 72 which are supported and patterned by the intermediate base film 60, the intermediate base film 60 and A first transparent adhesive layer 73 provided on the first conductive layer 71 and a second transparent adhesive layer 74 provided on the intermediate base film 60 and the first conductive layer 72 are provided.

  The first conductive layer 71 functions as an electrode in the X direction in the touch panel sensor 70 and has a pattern shape similar to that of the first conductive layer 31. The first conductive layer 71 is provided on the first low refractive index layer 14 of the intermediate base film 60. The second conductive layer 72 functions as an electrode in the Y direction in the touch panel sensor 70 and has the same pattern shape as the second conductive layer 41. The second conductive layer 72 is provided on the second low refractive index layer 62 of the intermediate base film 60.

  The first conductive layer 71 is disposed closer to the observer than the intermediate base film 10, and the second conductive layer 72 is disposed closer to the light source than the intermediate base film 10.

  The first conductive layer 71 and the second conductive layer 72 preferably have the same configuration as the first conductive layers 31 and 51 and the second conductive layers 41 and 52. The first conductive layer 71 and the second conductive layer 72 can be made of the same material as the first conductive layers 31 and 51 and the second conductive layers 41 and 52.

  Since the first conductive layer 71 and the second conductive layer 72 are formed on both surfaces of the intermediate base film 60, they can be patterned by photolithography, and in this case, the first conductive layer 71 The positional accuracy of the layer 71 and the second conductive layer 72 can be increased.

  In order to describe the present invention in detail, examples will be described below, but the present invention is not limited to these descriptions.

<Preparation of composition for transparent layer>
First, each component was mix | blended so that it might become a composition shown below, and the composition for transparent layers was obtained.
(Transparent layer composition 1)
Pentaerythritol triacrylate (PETA): 30 parts by mass Polymerization initiator (product name “Irgacure 184”, manufactured by BASF Japan Ltd.): 1.5 parts by mass Methyl isobutyl ketone: 70 parts by mass

(Transparent layer composition 2)
Pentaerythritol triacrylate (PETA): 18 parts by mass Propylene glycol monomethyl ether acetate (PGMEA): 12 parts by mass Polymerization initiator (product name “Irgacure 184”, manufactured by BASF Japan Ltd.): 1.5 parts by mass Isobutyl ketone: 70 parts by mass

<Preparation of composition for high refractive index layer>
Each component was mix | blended so that it might become a composition shown below, and the composition for high refractive index layers was obtained.
(Composition 1 for high refractive index layer)
High refractive index fine particle dispersion (Methyl ethyl ketone dispersion of ZrO ₂ fine particles (solid content: 30% by mass), product name “MZ-230X”, manufactured by Sumitomo Osaka Cement Co., Ltd.): 58.8 parts by mass Pentaerythritol triacrylate ( Product name “KAYARAD PET-30” (manufactured by Nippon Kayaku Co., Ltd.): 11.8 parts by mass / polymerization initiator (product name “Irgacure 184”, manufactured by BASF Japan): 0.6 parts by mass / methyl isobutyl ketone (MIBK) ): 28.8 parts by mass

(Composition 2 for high refractive index layer)
High refractive index fine particle dispersion (Methyl ethyl ketone dispersion of ZrO ₂ fine particles (solid content: 30% by mass), product name “MZ-230X”, manufactured by Sumitomo Osaka Cement Co., Ltd.): 59.5 parts by mass Pentaerythritol triacrylate ( Product name “KAYARAD PET-30”, manufactured by Nippon Kayaku Co., Ltd .: 11.1 parts by mass / polymerization initiator (product name “Irgacure 184”, manufactured by BASF Japan): 0.6 parts by mass / methyl isobutyl ketone (MIBK) ): 28.8 parts by mass

(Composition 3 for high refractive index layer)
・ High refractive index fine particle dispersion (methyl ethyl ketone dispersion of ZrO ₂ fine particles (solid content: 30% by mass), product name “MZ-230X”, manufactured by Sumitomo Osaka Cement Co., Ltd.): 59.9 parts by mass. Pentaerythritol triacrylate ( Product name “KAYARAD PET-30” (manufactured by Nippon Kayaku Co., Ltd.): 10.7 parts by mass / polymerization initiator (product name “Irgacure 184”, manufactured by BASF Japan): 0.6 parts by mass / methyl isobutyl ketone (MIBK) ): 28.8 parts by mass

(Composition 4 for high refractive index layer)
・ High refractive index fine particle dispersion (Methyl ethyl ketone dispersion of ZrO ₂ fine particles (solid content: 30% by mass), product name “MZ-230X”, manufactured by Sumitomo Osaka Cement Co., Ltd.): 62.0 parts by mass. Pentaerythritol triacrylate ( Product name “KAYARAD PET-30” (manufactured by Nippon Kayaku Co., Ltd.): 8.6 parts by mass / polymerization initiator (product name “Irgacure 184”, manufactured by BASF Japan): 0.6 parts by mass / methyl isobutyl ketone (MIBK) ): 28.8 parts by mass

<Preparation of composition for low refractive index layer>
Each component was mix | blended so that it might become the composition shown below, and the composition for low refractive index layers was obtained.
(Composition 1 for low refractive index layer)
Hollow silica fine particles (Methyl isobutyl ketone dispersion of hollow silica fine particles (solid content: 20% by mass), average particle size: 50 nm): 40 parts by mass Pentaerythritol triacrylate (PETA) (Product name “PETIA”, Daicel Cytec Co., Ltd.): 10 parts by mass / polymerization initiator (product name “Irgacure 127”, manufactured by BASF Japan): 0.35 parts by mass / modified silicone oil (product name “X22164E”, manufactured by Shin-Etsu Chemical Co., Ltd.): 0 .5 parts by mass-Methyl isobutyl ketone (MIBK): 320 parts by mass-Propylene glycol monomethyl ether acetate (PGMEA): 161 parts by mass

(Composition 2 for low refractive index layer)
Hollow silica fine particles (Methyl isobutyl ketone dispersion of hollow silica fine particles (solid content: 20% by mass), average particle size: 50 nm): 40.5 parts by mass Pentaerythritol triacrylate (PETA) (product name “PETIA”, Daicel Cytec Co., Ltd.): 9.5 parts by mass Polymerization initiator (Product name “Irgacure 127”, manufactured by BASF Japan): 0.35 parts by mass Modified silicone oil (Product name “X22164E”, Shin-Etsu Chemical Co., Ltd.) Manufactured): 0.5 parts by mass Methyl isobutyl ketone (MIBK): 320 parts by mass Propylene glycol monomethyl ether acetate (PGMEA): 161 parts by mass

(Composition 3 for low refractive index layer)
Hollow silica fine particles (Methyl isobutyl ketone dispersion of hollow silica fine particles (solid content: 20% by mass), average particle size: 50 nm): 41 parts by mass Pentaerythritol triacrylate (PETA) (product name “PETIA”, Daicel 9 parts by mass / polymerization initiator (product name “Irgacure 127”, manufactured by BASF Japan): 0.35 parts by mass / modified silicone oil (product name “X22164E”, manufactured by Shin-Etsu Chemical Co., Ltd.): 0 .5 parts by mass-Methyl isobutyl ketone (MIBK): 320 parts by mass-Propylene glycol monomethyl ether acetate (PGMEA): 161 parts by mass

(Composition 4 for low refractive index layer)
Hollow silica fine particles (Methyl isobutyl ketone dispersion of hollow silica fine particles (solid content: 20% by mass), average particle size: 50 nm): 38.4 parts by mass Pentaerythritol triacrylate (PETA) (product name “PETIA”, Daicel Cytec Co., Ltd.): 8.4 parts by mass, polymerization initiator (product name “Irgacure 127”, manufactured by BASF Japan): 0.35 parts by mass, modified silicone oil (product name “X22164E”, Shin-Etsu Chemical Co., Ltd.) Manufactured): 0.5 parts by mass Methyl isobutyl ketone (MIBK): 320 parts by mass Propylene glycol monomethyl ether acetate (PGMEA): 161 parts by mass

(Composition 5 for low refractive index layer)
Hollow silica fine particles (Methyl isobutyl ketone dispersion of hollow silica fine particles (solid content: 20% by mass), average particle size: 50 nm): 35.7 parts by mass Pentaerythritol triacrylate (PETA) (product name “PETIA”, Daicel Cytec Co., Ltd.): 5.7 parts by mass Polymerization initiator (Product name “Irgacure 127”, manufactured by BASF Japan): 0.35 parts by mass Modified silicone oil (Product name “X22164E”, Shin-Etsu Chemical Co., Ltd.) Manufactured): 0.5 parts by mass Methyl isobutyl ketone (MIBK): 320 parts by mass Propylene glycol monomethyl ether acetate (PGMEA): 161 parts by mass

<Example 1>
A polyethylene terephthalate base material (product name “Cosmo Shine”, manufactured by Toyobo Co., Ltd.) having a refractive index of 1.62 and a thickness of 125 μm is prepared as a transparent base material, and a transparent layer composition is formed on both sides of the polyethylene terephthalate base material. 1 was applied to form a coating film. Next, 50 ° C. dry air was passed through the formed coating film at a flow rate of 0.2 m / s for 15 seconds, and then 70 ° C. dry air was passed through for 30 seconds at a flow rate of 10 m / s. By evaporating the solvent in the coating film and irradiating the ultraviolet light with an integrated light amount of 100 mJ / cm ² under a nitrogen atmosphere (oxygen concentration of 200 ppm or less) to cure the coating film, the refractive index is increased. A transparent layer having a thickness of 1.52 and a thickness of 4.5 μm was formed. Subsequently, the composition 1 for high refractive index layers was apply | coated on each transparent layer, and the coating film was formed. And after drying the formed coating film for 1 minute at 40 degreeC, under a nitrogen atmosphere (oxygen concentration 200 ppm or less), it hardens | cures by irradiating with an ultraviolet-ray with the integrated light quantity of 100 mJ / cm < ² >, and refractive index is 1. And a high refractive index layer having a thickness of 50 nm was formed. Subsequently, the composition 1 for low refractive index layers was apply | coated on each high refractive index layer, and the coating film was formed. And after drying the formed coating film for 1 minute at 40 degreeC, under a nitrogen atmosphere (oxygen concentration 200 ppm or less), it hardens | cures by irradiating with an ultraviolet-ray with the integrated light quantity of 100 mJ / cm < ² >, and refractive index is 1. A low refractive index layer having a thickness of .49 and a thickness of 20 nm was formed, and an intermediate substrate film according to Example 1 was produced.

<Example 2>
In Example 2, it was carried out except that the high refractive index layer composition 1 and the low refractive index layer composition 2 were used in place of the high refractive index layer composition 1 and the low refractive index layer composition 1. In the same manner as in Example 1, an intermediate substrate film was produced. The refractive index of the high refractive index layer of the base film according to Example 2 was 1.69, and the refractive index of the low refractive index layer was 1.51.

<Example 3>
In Example 3, instead of the composition 1 for the transparent layer, the composition 1 for the high refractive index layer, the composition 1 for the low refractive index layer, the composition 2 for the transparent layer, the composition 3 for the high refractive index layer, the low An intermediate substrate film was produced in the same manner as in Example 1 except that the refractive index layer composition 3 was used and the thickness of the high refractive index layer was changed to 60 nm. The refractive index of the transparent layer of the base film according to Example 3 was 1.53, the refractive index of the high refractive index layer was 1.70, and the refractive index of the low refractive index layer was 1.53.

<Comparative Example 1>
In Comparative Example 1, instead of the transparent layer composition 1, the high refractive index layer composition 1, the low refractive index layer composition 1, the transparent layer composition 2, the high refractive index layer composition 4, An intermediate substrate film was produced in the same manner as in Example 1 except that the refractive index layer composition 3 was used and the thickness of the high refractive index layer was changed to 60 nm. The refractive index of the transparent layer of the base film according to Comparative Example 1 was 1.53, the refractive index of the high refractive index layer was 1.76, and the refractive index of the low refractive index layer was 1.53.

<Comparative example 2>
In Comparative Example 2, instead of the transparent layer composition 1, the high refractive index layer composition 1, and the low refractive index layer composition 1, the transparent layer composition 2, the high refractive index layer composition 4, and the low refractive index layer composition 1. An intermediate substrate film is produced in the same manner as in Example 1 except that the refractive index layer composition 4 is used, the thickness of the high refractive index layer is 65 nm, and the thickness of the low refractive index layer is 30 nm. did. The refractive index of the transparent layer of the base film according to Comparative Example 2 was 1.53, the refractive index of the high refractive index layer was 1.76, and the refractive index of the low refractive index layer was 1.43.

<Comparative Example 3>
In Comparative Example 3, the high refractive index layer composition 1 and the low refractive index layer composition 1 were used in place of the high refractive index layer composition 1 and the low refractive index layer composition 1, and the high refractive index layer was used. An intermediate substrate film was produced in the same manner as in Example 1 except that the film thickness of the film was 65 nm and the film thickness of the low refractive index layer was 30 nm. The refractive index of the high refractive index layer of the base film according to Comparative Example 3 was 1.76, and the refractive index of the low refractive index layer was 1.33.

<a ^* Oyobib ^* Nobaratsuki>
In each of the intermediate substrate films obtained in the examples and comparative examples, variations in a ^* and b ^* were determined as follows. Specifically, using VAR-7010 manufactured by JASCO Corporation, each intermediate substrate film is irradiated with light from the low refractive index layer side while changing the incident angle every 5 ° within a range of 5 ° to 65 °. Then, the a * value and the b * value were obtained from the reflected light in the respective regular reflection directions. The measurement conditions were as follows. As a light source, a deuterium (D2) lamp and a tungsten halogen (WI) lamp are used, a polarizer whose transmission axis is inclined by 45 °, a measurement range of 380 nm to 780 nm, a data acquisition interval of 1 nm, and an incident angle. And the position of the detector were synchronized, and measurement was performed so that specularly reflected light was captured. Then, from the obtained a ^* value and b ^* value at each incident angle, the absolute value of the difference between the maximum value and the minimum value was calculated, and the variation of the a ^* value and the variation of the b ^* value were obtained.

<Color variation>
It was evaluated whether or not the color of each intermediate substrate film varied when the intermediate substrate films obtained in Examples and Comparative Examples were viewed from various directions. The evaluation criteria were as follows.
○: No variation in color could be confirmed.
X: Variation in color was confirmed.

The results are shown in Tables 1 to 3 below.

As shown in Table 3, the intermediate substrate films of Comparative Examples 1 to 3 satisfy the requirement that the variation in a ^* value is within 1.0 and the variation in b ^* value is within 1.6. As a result, variation in color could not be suppressed.

On the other hand, since the intermediate substrate films of Examples 1 to 3 satisfy the requirement that the variation in a ^* value is within 1.0 and the variation in b ^* value is within 1.6, The change in color could be suppressed.

DESCRIPTION OF SYMBOLS 10, 60 ... Intermediate base film 11 ... Transparent base material 11A, 11B ... Surface 12 ... 1st transparent layer 13 ... 1st high refractive index layer 14 ... 1st low refractive index layer 15 ... 2nd transparent layer 20, 50, 80 ... touch panel sensors 31, 51, 71 ... first conductive layer 41, 52, 72 ... second conductive layer 61 ... second high refractive index layer 62 ... second low refractive index layer

Claims (8)

An intermediate substrate film for supporting the patterned conductive layer,
A transparent substrate;
A first high refractive index layer laminated on one surface of the transparent substrate;
A first low refractive index layer laminated on the first high refractive index layer and having a refractive index lower than the refractive index of the first high refractive index layer;
The normal direction of the surface of the intermediate substrate film is set to 0 °, and light is applied to the intermediate substrate film from the first low refractive index layer side while changing the incident angle every 5 degrees within a range of 0 ° to 75 °. When the a ^* value and b ^* value of the L ^* a ^* b ^* color system are determined from the reflected light in the regular reflection direction, the variation of the a ^* value is within 1.0, and An intermediate substrate film having a b ^* value variation of 1.6 or less.   The intermediate substrate film according to claim 1, wherein a refractive index difference between the first high refractive index layer and the first low refractive index layer is 0.10 or more and 0.22 or less.   The first high refractive index layer has a thickness of 20 nm to 80 nm and a refractive index of 1.62 to 1.72, and the first low refractive index layer is a film of 3 nm to 45 nm. The intermediate substrate film according to claim 1 or 2, having a thickness and a refractive index of 1.44 or more and 1.54 or less.   4. The apparatus according to claim 1, further comprising a first transparent layer having a refractive index of 1.47 or more and 1.57 or less between the transparent substrate and the first high refractive index layer. The intermediate substrate film described.   The intermediate substrate film according to claim 4, wherein the first transparent layer has a film thickness of 1 μm or more. A second high refractive index layer laminated on a surface opposite to the one surface of the transparent substrate;
The second low-refractive index layer that is laminated on the second high-refractive index layer and has a lower refractive index than the refractive index of the second high-refractive index layer. The intermediate substrate film according to any one of the above. The intermediate substrate film according to any one of claims 1 to 6,
A touch panel sensor comprising: a first conductive layer laminated on the first low refractive index layer of the intermediate base film and patterned. The intermediate substrate film according to claim 6,
A first conductive layer laminated and patterned on the first low refractive index layer of the intermediate substrate film;
A touch panel sensor comprising: a second conductive layer laminated on the second low refractive index layer of the intermediate base film and patterned.

Images