JP5625660B2 - Touch panel film and touch panel using the touch panel film - Google Patents

Description

The present invention relates to a touch panel using the superior touch panel film and the touch panel film its blocking resistance.

  When a hard coat is applied to a thermoplastic film such as a PET film, there is a problem that blocking occurs during film winding.

  As one method for dealing with such a problem, a method is known in which blocking is prevented by applying a thin film containing particles to the back surface of a substrate and forming an uneven structure on the surface of the coating film (Patent Document 1). ).

  However, in the method of Patent Document 1, the thickness of the coating film must be made smaller than the particle size, the mechanical strength is lowered, and scratches are easily caused, and glare and the like also occur. From such a background, there is a need for a hard coat film that can prevent blocking and that is excellent in optical properties and hard coat properties.

JP 2005-132897 A

The present invention has been made by paying attention to the above-described problems in the prior art, and the problem is that it can prevent blocking and is excellent in optical characteristics and hard coat properties . It is to provide a film and a touch panel using the touch panel film.

  The present inventors diligently studied the above problem and found that the above problem can be solved by using the means described below.

That is, an invention according to claim 1, containing a hard coat film, and a transparent conductive layer provided on the hard coat film, the hard coat film, and at least one or more resins and waxes is composed of the hard coat layer, the hard coat layer, the wax is precipitated by phase separation, Ri layers der which are arranged on the surface, the resin for forming the hard coat layer, photocurable acrylate A monomer or oligomer having a main component, and a radical-generating photopolymerization initiator, and the difference in SP value between the monomer or oligomer having the acrylate as a main component and the wax is 1.0 or more. , an average particle diameter of the wax is a touch panel film, wherein the at 1.0μm or less.

Invention according to claim 2, wherein the wax is paraffin wax, microcrystalline wax, carnauba wax, polyethylene wax, among Fischer Tron Tropsch wax, to claim 1, characterized in that it contains at least one more It is a film for touchscreens of description.

According to a third aspect of the invention, the addition amount of the wax, to claim 1 or 2, wherein the acrylate is less than 20 mass% to 1 mass% with respect to monomer or oligomer as a main component It is a film for touchscreens of description.

A fourth aspect of the present invention is a touch panel using the touch panel film according to any one of the first to third aspects.

The film for a touch panel of the present invention contains a wax in a monomer or oligomer containing acrylate as a main component, and the wax is precipitated by phase separation after application of the hard coat layer, and is arranged on the surface, thereby improving the slip property of the surface. And blocking can be prevented. Moreover, transparency of a film is not impaired by an average particle diameter being 1.0 micrometer or less.

  As described above, by adopting the present invention, it is possible to prevent blocking that occurs when a hard film is applied to a thermoplastic film such as a PET film, and the degree of influence on optical properties and hard coat properties is also improved. It is possible to provide a hard coat film with few and improved quality.

It is a schematic cross section which shows embodiment of the hard coat film with which the film for touchscreens of this invention is provided .

  Next, embodiments of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the hard coat film of this embodiment is obtained by laminating a hard coat layer 2 on a plastic film substrate 1 made of a thermoplastic resin. If necessary, two or more layers or hard coat layers may be laminated on both surfaces of the film substrate 1. When hard coat layers are laminated on both surfaces of the film substrate 1, the effect of blocking prevention according to the present embodiment is further remarkable.

  Although the thickness of the film base material 1 used for this embodiment is not specifically limited, Preferably it is 25 micrometers or more and 500 micrometers or less, More preferably, they are 50 micrometers or more and 300 micrometers or less. As the film substrate 1, for example, a plastic film made of a thermoplastic resin is used.

  The plastic film is not particularly limited, and can be appropriately selected from known plastic films. Specifically, polyethylene film, polypropylene film, polyester film, polyvinyl chloride film, cellophane, nylon film, polyvinyl alcohol film, polycarbonate film, polyvinylidene chloride film, polyacetate film, polystyrene film, acrylic film, heat resistance -Plastic films such as engineering plastic films, fluororesin films, and triacetyl cellulose films.

  The hard coat agent for forming the hard coat layer 2 contains a monomer or oligomer containing acrylate as a main component, a photopolymerization initiator, and a wax. For example, the monomer or oligomer mainly composed of acrylate contained in the hard coat agent is a photocurable acrylate monomer or photocurable acrylate oligomer.

  The acrylate as the main component of the hard coat agent used in the present embodiment is not particularly limited, but a resin that can withstand the temperature during drying and maintain transparency is preferable. In addition to the mechanical properties and transparency after curing, chemical resistance, and heat resistance, as well as various physical properties such as low viscosity during coating processing, specifically, more than three functionalities that can be expected to achieve three-dimensional crosslinking An ultraviolet curable resin obtained by crosslinking a monomer or oligomer containing acrylate as a main component is preferable.

  As trifunctional or higher acrylates, trimethylolpropane triacrylate, isocyanuric acid EO-modified triacrylate, pentaerythritol triacrylate, dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, Ditrimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, polyester acrylate and the like are preferable. Particularly preferred are isocyanuric acid EO-modified triacrylates and polyester acrylates. These may be used alone or in combination of two or more. In addition to these tri- or higher functional acrylates, so-called acrylic resins such as epoxy acrylate and urethane acrylate can be used in combination. Even if any coating method is used, these resins are preferably those that can be cured within 5 minutes in consideration of industrial production.

  Examples of the base curable resin include compounds having at least one crosslinkable double bond in one molecule. For example, the photocurable resin is preferably an acrylic resin such as polyurethane acrylate, epoxy acrylate, or polyol acrylate. Specifically, it contains a crosslinkable oligomer, a monofunctional or polyfunctional monomer, a photopolymerization initiator, a photoinitiator auxiliary agent, and the like.

  As the crosslinkable oligomer, acrylic oligomers such as polyester (meth) acrylate, polyether (meth) acrylate, polyurethane (meth) acrylate, epoxy (meth) acrylate, and silicone (meth) acrylate are preferable. Specific examples include polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, bisphenol A type epoxy acrylate, polyurethane diacrylate, cresol novolac type epoxy (meth) acrylate, and the like.

  As the monofunctional or polyfunctional monomer, acrylic monomers such as (meth) acrylic acid esters are preferable. Specific examples of the bifunctional (meth) acrylic acid ester include tripropylene glycol di (meth) acrylate, 1,6-hexanediol diacrylate, and tetraethylene glycol di (meth) acrylate. Examples of the trifunctional (meth) acrylic acid ester include trimethylolpropane tri (meth) acrylate and pentaerythritol tri (meth) acrylate. Examples of tetrafunctional (meth) acrylic acid esters include tetramethylolmethane tetra (meth) acrylate and pentaerythritol tetra (meth) acrylate. Examples of hexafunctional (meth) acrylic acid esters include dipentaerythritol hexaacrylate.

  The wax to be contained in the hard coat layer 2 may be any wax that can be deposited by phase separation and arranged on the surface when the hard coat layer is formed, and natural wax or synthetic wax can be used. For example, natural waxes include petroleum waxes such as paraffin wax and microcrystalline wax, and plant waxes such as carnauba wax. In addition, examples of the synthetic wax include synthetic hydrocarbons such as polyethylene wax and Fischer-Tropsch wax.

  One of the indexes indicating the phase separation of the wax is SP value.

  The SP value is an abbreviation for a solubility parameter and is a measure of the solubility of a two-component solution. It is empirically known that the smaller the difference between the SP values of the two components, the greater the solubility. The SP value can be calculated by the method described in R. f. Fedors, Polymer Engineering Science, 14, p147 (1967), and this value is adopted in the present invention.

  The difference in SP value between the monomer or oligomer containing acrylate as the main component and the wax is preferably 1.0 or more. When the difference in SP value is less than 1.0, the compatibility is high and phase separation is unlikely to occur, so the amount of wax arranged on the surface is reduced and the effect of preventing blocking is reduced, which is not preferable.

  The phase separation of the wax occurs during drying after the hard coat layer 2 is applied or during curing. Therefore, for example, the amount of wax arranged on the surface varies depending on the drying method or the curing method.

  The heating temperature during drying is 30 to 150 ° C., preferably 40 to 120 ° C., and the heating time is 0.1 to 20 minutes, preferably 0.3 to 10 minutes. If the heating temperature is too low or the heating time is too short, the amount of wax arranged on the surface becomes insufficient, which is not preferable. On the other hand, when the heating temperature is too high or the heating time is too long, the haze increases, which is not preferable.

As light to be irradiated upon curing, light having an exposure amount of 0.05 to 5 J / cm ² , preferably 0.1 to 3 J / cm ² can be used. If it is less than 0.05 J / cm ² , the amount of wax arranged on the surface becomes insufficient, which is not preferable. On the other hand, if it exceeds 5 J / cm ² , haze increases, which is not preferable.

  The method of changing the amount of the wax arranged on the surface is not limited to the above method, as long as the wax is precipitated by phase separation as a result of the formation of the hard coat layer and can be arranged on the surface. There is no particular limitation.

  The average particle size of the wax is 1.0 μm or less, preferably 0.01 to 0.5 μm when the coating needs transparency. When it exceeds 1.0 μm, the transparency is lowered.

  The content of the wax is preferably 1% by mass or more and 20% by mass or less with respect to the monomer or oligomer mainly composed of acrylate. If it is larger than 20%, the haze increases and this causes a problem in appearance. On the other hand, if it is less than 1%, there is not enough wax arranged on the surface, and blocking occurs when the hard coat film is rolled.

  Moreover, although the film thickness of the hard-coat layer 2 is determined by required hardness and a softness | flexibility, as a preferable film thickness, it is 1-15 micrometers. If the film thickness is less than 1 μm, sufficient film strength cannot be obtained and the film is easily damaged. In addition, since the film thickness tends to vary, problems such as interference fringes occur. On the other hand, if it exceeds 15 μm, cracks due to bending may occur, and curling tends to occur in the hard coat film to be formed.

  In the present embodiment, when the active energy ray is ultraviolet light, it is necessary to add a photosensitizer (photopolymerization initiator). As radical-generating photoinitiators, benzoin and its alkyl ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzyl methyl ketal; acetophenone, 2,2, -dimethoxy-2-phenylacetophenone, Acetophenones such as 1-hydroxycyclohexyl phenyl ketone; anthraquinones such as methylanthraquinone, 2-ethylanthraquinone, 2-amylanthraquinone; thioxanthones such as thioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone; acetophenone Ketals such as dimethyl ketal and benzyl dimethyl ketal; benzophenone, 4,4-bismethylaminobenzophenone, etc. Benzophenones and azo compounds, and the like. These can be used alone or as a mixture of two or more thereof, and further, tertiary amines such as triethanolamine and methyldiethanolamine; benzoic acid derivatives such as 2-dimethylaminoethylbenzoic acid and ethyl 4-dimethylaminobenzoate, etc. It can be used in combination with a photoinitiator aid or the like.

  The addition amount of the photopolymerization initiator is 0.1% by mass or more and 10% by mass or less with respect to the main component acrylate. If it is less than 0.1% by mass, the hard coat layer is not sufficiently cured, which is not preferable. On the other hand, when the content exceeds 10% by mass, yellowing of the hard coat layer occurs or weather resistance decreases, which is not preferable.

  The light used for curing the photocurable resin is ultraviolet rays, electron beams, or gamma rays, and in the case of electron beams or gamma rays, it is not always necessary to contain a photopolymerization initiator or a photoinitiating aid. As these radiation sources, high pressure mercury lamps, xenon lamps, metal halide lamps, accelerated electrons, and the like can be used.

  The solvent is not particularly limited as long as it dissolves the main component acrylate. Specifically, as a solvent, ethanol, isopropyl alcohol, isobutyl alcohol, benzene, toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, n-butyl acetate, isoamyl acetate, ethyl lactate, methyl cellosolve, ethyl cellosolve, Examples include butyl cellosolve, methyl cellosolve acetate, and propylene glycol monomethyl ether acetate. These solvents may be used alone or in combination of two or more.

  Although the coating method to the film base material 1 is not particularly limited, practically, a die coater, curtain flow coater, roll coater, reverse roll coater, gravure coater, knife coater, bar coater, spin coater, Coating with a micro gravure coater or the like is common.

  The hard coat film of the present invention can be used as a film for a touch panel by providing a transparent conductive layer on the hard coat film.

  The material for forming the transparent conductive layer is not particularly limited, and examples thereof include indium, tin composite oxide (ITO), tin oxide, copper, aluminum, nickel, and chromium. The transparent conductive layer may be formed by stacking different forming materials among the above forming materials.

  Common methods for forming the transparent conductive layer include PVD methods such as sputtering, vacuum deposition, and ion plating, coating methods, and printing methods.

  In addition, in order to improve the adhesion between the transparent conductive layer and the hard coat film, a metal composed of a single metal element or an alloy of two or more metal elements between the transparent conductive layer and the hard coat film. A layer may be provided. As the metal layer forming material, it is preferable to use a metal selected from the group consisting of silicon, titanium, tin, and zinc.

The usefulness of the present invention will be specifically described below with reference to examples and comparative examples. However, the present invention is not limited to these examples. In addition, a part is a mass reference | standard unless there is particular notice.

<Preparation of hard coat layer>
In Table 1 below, the compositions constituting the hard coat layers used in Examples 1 to 4 and Comparative Examples 1 and 2 are described.

With the combination shown in Table 1, it was applied to a polyethylene terephthalate film (manufactured by Teijin Ltd., 100 μm thickness) with a wire bar to a cured film thickness of 8 μm, dried, and irradiated with 400 mJ / cm ² ultraviolet rays with a metal halide lamp A hard coat layer was formed. Table 1 shows the evaluation results of blocking resistance, pencil hardness, and haze of each hard coat film.

<Evaluation method>
(1) Blocking resistance Two hard coat films were used, the hard coat layer surfaces were brought into close contact with each other and pressurized at 250 g / cm ² , the blocking state of both layers at that time was observed, and the following evaluation criteria were used. evaluated.
○: Both layer surfaces were not intimate Δ: Both layer surfaces were slightly adhered and adhered ×: Both layer surfaces were adhered and adhered (2) Pencil hardness According to JIS-K5400 Evaluation was performed.

(3) Haze Using a haze meter (manufactured by Suga Test Instruments Co., Ltd.), the diffusion light transmittance (Td (%)) and the total light transmittance (Tt (%)) of the antiglare film are measured, and the haze is calculated. did.
Haze (%) = Td / Tt × 100
In the hard coat films of Examples 1 to 4, compared to the hard coat film of Comparative Example 1, by adding a wax to the monomer or oligomer mainly composed of acrylate to form a hard coat layer, It was confirmed that the blocking property was improved. In particular, the anti-blocking property of Example 2 which is a hard coat film having a large difference in SP value between the monomer or oligomer mainly composed of acrylate and the wax was improved as compared with Comparative Example 2. Further, by making the addition amount of the wax 1% by mass or more and 20% by mass or less, it is possible to provide a hard coat film that has less influence on optical properties and hard coat properties and is improved in quality. .

DESCRIPTION OF SYMBOLS 1 ... Film base material 2 ... Hard-coat layer 3 ... Wax

Claims (4)

Hard coat film,
A transparent conductive layer provided on the hard coat film,
The hard coat film is
Is composed of a hard coat layer containing at least one or more resins and waxes, the hard coat layer, the wax is precipitated by phase separation, Ri layers der which are arranged on the surface,
The resin that forms the hard coat layer contains a monomer or oligomer mainly composed of a photocurable acrylate, and a radical-generating photopolymerization initiator,
The difference in SP value between the wax or the monomer or oligomer mainly composed of the acrylate is 1.0 or more,
The touch panel film average particle diameter of the wax, characterized in der Rukoto below 1.0 .mu.m. The touch panel film according to claim 1, wherein the wax contains at least one of paraffin wax, microcrystalline wax, carnauba wax, polyethylene wax, and Fischer-Tropsch wax. The touch panel film according to claim 1 or 2, wherein the amount of the wax added is less than 20 mass% to 1 mass% with respect to monomer or oligomer as a main component the acrylate. Touch panel characterized by using a touch panel film according to any one of claims 1 to 3.

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