JP2015041135A - Method for manufacturing film for touch panel, film for touch panel, and touch panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film for a touch panel, which substantially prevents scattering of light and significantly improves visibility.SOLUTION: A film 10 for a touch panel comprises: a film (A) having a functional film 4 formed on one surface of a first substrate film 1 and having a transparent electrode 2' formed on the other surface; and a film (B) having a transparent electrode 2' formed on one surface of a second substrate film 1. The films (A) and (B) are laminated via a pressure-sensitive adhesive 5 in such a manner that the transparent electrodes 2' of the films face each other. The functional film 4 includes at least a hard coat layer.

Description

  The present invention relates to a method for producing a film for a touch panel provided with a functional film, a film for a touch panel, and further to a touch panel.

  2. Description of the Related Art In recent years, touch panel type input devices (hereinafter simply referred to as touch panels) have been adopted in operation units of various electronic devices such as smartphones, portable information terminals such as tablets, and car navigation systems. The touch panel is used as an input device that detects a contact position of a fingertip or a pen tip on a display surface of a display panel such as a liquid crystal display device or an organic EL device. The touch panel system is roughly classified into a resistive film type, a capacitance type, an optical type, and an ultrasonic type, and each has a merit and a demerit, and is used properly according to the application.

  Among them, the capacitive touch panel has a matrix-like translucent conductive film formed on a single transparent substrate, and changes in the capacitance induced by the contact of a finger or the like between the electrodes. The position to be touched on the touch panel is specified by detecting it as a weak current change. The electrostatic capacitance type further includes a surface type and a projection type. A projected capacitive touch panel includes a plurality of electrodes arranged on a grid in the X direction and the Y direction, is capable of multi-touch, and is currently spreading rapidly.

  There are a film type and a glass type in the projected capacitive touch panel sensor. The film type is advantageous in that it is easy to remove bubbles when it is bonded to another display device or a cover glass because it is lightweight, hard to break, inexpensive to manufacture, and flexible. On the other hand, the glass type has higher transmittance than the film, and the positional accuracy of the wiring pattern formed on the glass is superior to that of the film. Therefore, the frame part covering the wiring can be made smaller, and the surface smoothness can be reduced. Since it is excellent in properties, there is an advantage that it looks better than the film type. However, since glass is broken by an impact such as dropping, it is necessary to provide a scattering prevention film on the glass surface. For small products such as smart phones that require high definition and low power consumption, such as portable terminals, glass types are often used, such as tablet computers and televisions that require low cost and easy bonding, etc. Many film types are used for medium and large products. (Patent Document 2)

  A film-type projected capacitive touch panel sensor is generally composed of two layers of transparent electrodes for the X direction and Y direction and an interlayer insulating layer between the two transparent electrodes. Also, a single-sided structure in which two transparent electrode layers are formed on one side of a film base by forming it with an interlayer insulating layer, and the film base is also used as an interlayer insulating layer, and the two transparent electrode layers are used as the film. There are two types of double-sided structures formed on both sides of the substrate.

  In the above-mentioned transparent electrode, indium tin oxide (ITO) is generally used because of its high transparency and excellent practicality. In addition, new conductive materials such as conductive polymers and silver nanowires have been put into practical use. Furthermore, a method has been disclosed in which a transparent electrode is made of a mesh structure in which fine conductive metal fine-line patterns are stretched in a lattice pattern to achieve both low resistance and transparency (for example, Patent Documents). 1). ITO with high transparency is widely used for small products such as portable terminals. On the other hand, when the size is 15 inches or more, particularly 20 inches or more, the wiring resistance of the ITO wiring becomes high and the touch position detection sensitivity is lowered, so that the use of a metal wiring with a lower resistance of the mesh structure is becoming widespread.

  In general, handwritten input tablets consisting of a touch panel and a reflective liquid crystal panel, in particular, are highly visible in indoor and outdoor environments due to the light reflected from the display unit depending on the direction and angle of the light that accompanies the usage environment. There was a problem of lowering. In particular, if there is a gap between the display unit and the protective film or between the film sensors, light reflection occurs in the apparatus, and there is a problem that the visibility is remarkably lowered. (Patent Document 3)

JP 2012-53644 A JP 2012-230491 A JP 2001-147777 A

  The present invention has been made in view of the above problems, and it is an object of the present invention to provide a film for a touch panel that hardly causes light scattering and significantly improves visibility.

  The invention according to claim 1 for achieving the above object is characterized in that a film A in which a functional film is formed on one surface of a first base film and a transparent electrode is formed on the other surface; A film for a touch panel, which is formed by laminating a film B in which a transparent electrode is formed on one surface of the base film so that the transparent electrodes face each other through an adhesive.

  The invention according to claim 2 is the film for a touch panel according to claim 1, wherein the functional film includes at least a hard coat layer.

  The invention according to claim 3 is a film A comprising a step of forming a functional film on one surface of the first base film, and a step of forming a transparent electrode on the other surface, and a second base film. A method for producing a film for a touch panel, comprising: a step of laminating a film B comprising a step of forming a transparent electrode on one surface of the film with an adhesive layer so that the respective transparent electrodes face each other. It is.

  The invention according to claim 4 is characterized in that the step of forming the transparent electrode includes a step of forming a film of indium tin oxide (ITO) using a sputtering apparatus and etching using an etching apparatus. 3 is a method for producing a film for a touch panel according to 3.

  In the invention according to claim 5, the step of forming the transparent electrode is a linear shape having a width of 20 μm or less made of at least one metal material selected from the group consisting of Cu, Ag, Pt, Au, Al, Zn, and Zr. It is a manufacturing method of the film for touchscreens of Claim 3 which has the process of forming the electrode which carried out the mesh arrangement | positioning of the pattern.

  The invention according to claim 6 is the method for manufacturing a film for a touch panel according to claim 5, wherein the metal material is Cu.

  The invention according to claim 7 is a touch panel manufactured using the method for manufacturing a film for touch panel according to any one of claims 3 to 6.

  According to invention of Claim 1 and 3, film A in which a functional film is formed on one surface of the first base film and a transparent electrode is formed on the other surface, and the second substrate By laminating the film B in which the transparent electrode is formed on one surface of the material film so that the transparent electrodes face each other through the adhesive, the adhesive between the films A and B has no gap. It is possible to provide a film for a touch panel that is filled, hardly scatters light, and remarkably improves visibility.

  According to invention of Claim 2, since the said functional film contains a hard-coat layer at least, although the base material is a film, it has the outstanding tolerance with respect to impacts, such as surface mechanical strength and a fall. The film for touch panels which has can be provided.

  According to the inventions described in claims 4 to 6, since it becomes possible to efficiently manufacture a touch panel film with a functional film in which the transparent electrode has a mesh structure of ITO or metal wiring, A wide range of touch panel films can be provided, including touch panels with a size of 15 inches or more, particularly 20 inches or more.

  As a result of the formation of functional films such as hard coat and antireflection, the display part can be protected from impacts such as dropping, and surface reflection from outside light can be prevented, and a method for producing a film having excellent surface hardness and a touch panel The purpose is to provide.

The manufacturing-process figure of one Embodiment of the film for touchscreens of this invention. Sectional drawing of one Embodiment of the film A of FIG.

  The film for a touch panel of the present invention includes a film A in which a functional film is formed on one surface of the first base film and a transparent electrode is formed on the other surface, and one of the second base film. A film B having a transparent electrode formed on the surface is laminated so that the transparent electrodes face each other with an adhesive interposed therebetween.

  Hereinafter, based on FIG. 1, the manufacturing method of the film for touchscreens of this invention is demonstrated.

  As shown in FIG. 1A, a transparent conductive layer 2 is formed on one surface of the first base film 1. Next, as shown in FIG. 1B, a photosensitive resin composition (hereinafter referred to as a resist) is applied on the transparent conductive layer 2 and dried to form a resist film 3. Next, as shown in FIG.1 (c), it exposes through a mask and is developed, wash | cleaned, and dried after that, and a pattern is formed. Next, as shown in FIG. 1D, the transparent conductive layer 2 is etched. Thereafter, as shown in FIG. 1E, the residual resist film is peeled off to form a transparent electrode 2 ′. Then, as shown in FIG.1 (f), the functional film | membrane 4 is formed in the other surface of the 1st base film 1, and the film A is produced.

  1 (a) to 1 (e), a film B is manufactured through the same steps. As shown in FIG. 1 (g), the film A and the film B are each transparent with an adhesive 5 interposed therebetween. A film for a touch panel is produced by laminating so that the electrodes 2 'face each other. In addition, FIG. 2 shows one Embodiment of the film for touchscreens of this invention more concretely.

<Base film>
The substrate film 1 according to the present invention is a plastic film having high transparency (light transmittance), and satisfies physical properties that can be used as a transparent substrate of a functional film. Polyethylene terephthalate resin (PET) is preferable from the viewpoint of cost, but cellulose resin such as cellulose diacetate and cellulose triacetate, polyethylene resin, polypropylene resin, methacrylic resin, cyclic polyolefin resin, polystyrene resin, acrylonitrile- (poly) Styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), polyvinyl chloride resin, poly (meth) acrylic resin, polycarbonate resin, polyester resin, polyamide resin, polyamideimide A thermoplastic resin film having a thickness of 10 to 300 [mu] m manufactured from a base resin can be used, and PET having a thickness of 50 to 188 [mu] m is often used in terms of transparency, processability and cost. Moreover, the transparent film base material may be subjected to surface treatment such as easy adhesion treatment, plasma treatment, corona treatment or the like on one or both surfaces.

<Functional membrane>
Examples of the functional film 4 according to the present invention include a hard coat film, an antireflection film, and an antifouling film. Further, hard coat properties can be imparted to the antireflection film and the antifouling film.

  For example, the hard coat film indicates a hardness of “H” or higher in a pencil hardness test generally defined by JIS 5600-5-4 (1999). Hereinafter, components of the resin composition for forming a hard coat film will be described in order.

  The resin composition for forming a hard coat film is an ionizing radiation curable composition that is used after being crosslinked and cured by ionizing radiation energy such as electromagnetic waves, ultraviolet rays, visible rays, and electron beams, and has two or more in one molecule. It is preferable in terms of production efficiency and production stability that the main component is a polyfunctional monomer containing a (meth) acryloyl group in the molecule. In the case of curing by ultraviolet irradiation, a high pressure mercury lamp light source containing light having a wavelength in the range of 150 to 450 nm is used. In the case of electron beam curing, an electron beam with an irradiation voltage of 3 to 300 kGy in an acceleration voltage range of 10 to 500 kV, more preferably 30 to 200 kV is required.

  Polyfunctional monomers include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol (meth) acrylate, ethylene glycol di (meth) acrylate, triethylene glycol Di (meth) acrylate, tripropylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, 3-methylpentanediol di (meth) acrylate, diethylene glycol bis β- (meth) acryloyloxypropionate, trimethylolethane Tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tri (2-H Roxyethyl) isocyanate di (meth) acrylate, pentaerythritol tetra (meth) acrylate, 2,3-bis (meth) acryloyloxyethyloxymethyl [2.2.1] heptane, poly 1,2-butadiene di (meth) acrylate 1,2-bis (meth) acryloyloxymethylhexane, nonaethylene glycol di (meth) acrylate, tetradecane ethylene glycol di (meth) acrylate, 10-decanediol (meth) acrylate, 3,8-bis (meth) acryloyl Oxymethyltricyclo [5.2.10] decane, hydrogenated bisphenol A di (meth) acrylate, 2,2-bis (4- (meth) acryloyloxydiethoxyphenyl) propane, 1,4-bis ((meta ) Acryloyloxymethyl E) Cyclohexane, hydroxypivalin sun ester neopentyl glycol di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, epoxy-modified bisphenol A di (meth) acrylate, and the like. A polyfunctional monomer may be used independently and may use 2 or more types together. Further, if necessary, it can be copolymerized in combination with a monofunctional monomer.

Moreover, urethane acrylate is also mentioned as a preferred polyfunctional monomer in the present invention,
In general, a polyester polyol can be easily formed by reacting an acrylate monomer having a hydroxyl group with a product obtained by reacting a polyester polyol with an isocyanate monomer or a prepolymer.

  Specific examples include pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer, dipentaerythritol pentaacrylate hexamethylene diisocyanate urethane prepolymer, pentaerythritol triacrylate toluene diisocyanate urethane prepolymer, dipentaerythritol pentaacrylate toluene diisocyanate urethane prepolymer. Pentaerythritol triacrylate isophorone diisocyanate urethane prepolymer, dipentaerythritol pentaacrylate isophorone diisocyanate urethane prepolymer, and the like can be used. Moreover, these monomers can be used 1 type or in mixture of 2 or more types. Further, these may be monomers in the coating liquid, or may be oligomers that are partially polymerized.

  Examples of the photopolymerization initiator include 2,2-ethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, dibenzoyl, benzoin, benzoin methyl ether, benzoin ethyl ether, p-chlorobenzophenone, p-methoxybenzophenone, Michler ketone, acetophenone, 2 -Chlorothioxanthone and the like. You may use these individually or in combination of 2 or more types.

  Examples of the photosensitizer include tertiary amines such as triethylamine, triethanolamine and 2-dimethylaminoethanol, alkylphosphine such as triphenylphosphine, and thioethers such as β-thiodiglycol. These may be used alone or in combination of two or more.

  Furthermore, an antifoaming agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a polymerization inhibitor and the like can be contained for improving the performance.

  Next, the antireflection film will be described as a functional film according to the present invention. It is known to add fine particles to the antireflection film, and as the fine particles, those having transparency such as various metal oxides, glass, and plastic can be used. For example, metal oxides such as silica, zirconia, titania, calcium oxide, inorganic conductive fine particles such as conductive alumina, tin oxide, indium oxide, antimony oxide, polymethyl methacrylate, polystyrene, polyurethane, acrylic-styrene. Examples include crosslinked or uncrosslinked organic fine particles and silicone fine particles composed of various polymers such as polymers, melamine, and polycarbonate. These shapes are not particularly limited and may be bead-shaped spheres or may be indefinite shapes such as powders, but are preferably spherical, and particularly preferably spherical. . These fine particles can be used by appropriately selecting one kind or two or more kinds.

  The average particle diameter of the fine particles is 10 to 200 nm, preferably 10 to 100 nm. When the average particle diameter is less than 10 nm, a sufficient uneven shape cannot be formed, which is not sufficient for suppressing sticking. On the other hand, when the average particle diameter is 200 nm or more, light scattering occurs in the antireflection film, and the transmittance decreases. The ratio of the fine particles is appropriately determined in consideration of the average particle diameter of the fine particles, the thickness of the functional film, etc., but is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the resin.

As the solvent in the present invention, dibutyl ether, dimethoxymethane, dimethoxyethane, diethoxyethane, propylene oxide, 1,4-dioxane, 1,3-dioxolane, 1,3 are used as solvents for dissolving or swelling the cellulose film surface. Ethers such as, 5-trioxane, tetrahydrofuran, anisole and phenetole, and ketones such as acetone, methyl ethyl ketone, diethyl ketone, dipropyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone and methylcyclohexanone, Es such as ethyl formate, propyl formate, n-pentyl formate, methyl acetate, ethyl acetate, methyl propionate, propion brewed ethyl, n-pentyl acetate, and γ-ptyrolactone Le ethers, furthermore methyl cellosolve, cellosolve, butyl cellosolve, cellosolve such as cellosolve acetate. You may use these individually or in combination of 2 or more types. Moreover, it is preferable to use at least one of methyl acetate, ethyl acetate, methyl ethyl ketone, acetylacetone, acetone, and cyclohexanone.

  These solvents are preferably prepared such that the solvent is 50 to 150 parts by weight with respect to 100 parts by weight of the resin composition. When the solvent is 50 parts by weight or less, the viscosity of the coating solution increases, and a good coating surface cannot be formed by the wet coating method. On the other hand, if the solvent is 150 parts by weight or more, a functional film having a predetermined film thickness cannot be formed.

  The antireflection film having hard coat properties can be obtained by forming an antireflection film having a refractive index lower than the refractive index of the hard coat film on the hard coat film. For example, as a preferable form of the present invention, the refractive index of the hard coat film is 1.5 or more, and the refractive index of the low refractive index film is less than 1.5, more preferably 1.45 or less, still more preferably 1.35. The following is preferable. If the refractive index is 1.5 or more, the refractive index difference between the low refractive index film and the functional film such as the hard coat layer is small, and the reflection becomes high. Therefore, it is desirable that the refractive index is low.

  Examples of the low refractive index particles in the low refractive index film include the use of fine particles having voids. The fine particles having voids are a structure in which a gas is filled in a fine particle or a porous structure containing a gas. It is a fine particle that forms a structure selected from one or more and has a refractive index that is inversely proportional to the gas occupancy in the fine particle compared to the original refractive index of the fine particle.

  Also included are fine particles capable of forming a nanoporous structure at least partially selected from one or more of the inside and the surface depending on the form, structure, aggregation state, and dispersion state of the fine particles inside the coating. The low refractive index film using these fine particles can adjust the refractive index to 1.30 or more and 1.45 or less.

  Examples of inorganic fine particles having such voids include hollow silica fine particles. Since hollow silica fine particles having voids are easy to manufacture and have high hardness, when layered with a binder to form a low refractive index film, the layer strength is improved and the refractive index is 1.20 or more and 1 It is possible to adjust within a range of about 45 or less.

  The average particle size of the hollow silica fine particles is preferably 5 nm to 300 nm, the lower limit is 8 nm, the upper limit is more preferably 100 nm, the lower limit is 10 nm, and the upper limit is further preferably 80 nm.

  When the average particle diameter of the fine particles is within this range, excellent transparency can be imparted to the low refractive index layer. The hollow silica fine particles are usually used in an amount of 0.1 to 500 parts by weight, preferably 10 to 200 parts by weight, based on 100 parts by weight of the matrix resin in the low refractive index layer.

In the formation of a low refractive index film, a polyfunctional monomer containing two or more (meth) acryloyl groups in one molecule as a resin for forming a low refractive index film, hollow silica fine particles, and as necessary Accordingly, a solution or dispersion obtained by dissolving or dispersing an additive (polymerization initiator, antistatic agent, antiglare agent, etc.) in a solvent is used as a composition for forming a low refractive index film, and a coating film made of the composition is used. A low refractive index film can be obtained by forming and curing by ultraviolet irradiation or heating. In addition, well-known things can be used for additives, such as a polymerization initiator, an antistatic agent, and an anti-glare agent.

  As a polyfunctional monomer containing two or more (meth) acryloyl groups in one molecule of the low refractive index film forming resin, an ionizing radiation curable type used when forming a functional film such as a hard coat layer is used. Resins described in the resin can be used.

  The low refractive index film is usually applied after being diluted in a volatile solvent. In consideration of stability of the composition, wettability to a functional film such as a hard coat layer, volatility, etc., alcohols such as methanol, ethanol, isopropanol, butanol, 2-methoxyethanol are used as the dilution solvent. , Ketones such as acetone, methyl ethyl ketone and methyl isobutyl, esters such as methyl acetate, ethyl acetate and butyl acetate, ethers such as diisopropyl ether, glycols such as ethylene glycol, propylene glycol and hexylene glycol, ethyl cellosolve and butyl cellosolve Glycol ethers such as ethyl carbitol and butyl carbitol, aliphatic hydrocarbons such as hexane, heptane and octane, halogenated hydrocarbons, aromatic hydrocarbons such as benzene, toluene and xylene, N-methylpyrrole , Dimethylformamide and the like. You may use these individually or in combination of 2 or more types. Of these, methyl isobutyl ketone, methyl ethyl ketone, isopropyl alcohol (IPA), n-butanol, s-butanol, t-butanol, PGME, and PGMEA are preferable. Moreover, the preparation method of a composition should just be able to mix a component uniformly, should just implement according to a well-known method, and can carry out mixing and dispersion | distribution using a well-known apparatus.

The film thickness (nm) dA when forming the low refractive index film is represented by the following formula (1).
dA = mλ / (4 nA) Equation (1)
In the formula (1), nA is the refractive index of the low refractive index film, m is a positive odd number, λ is the wavelength, and m = 1 and λ = 480 to 580 nm are preferable.

  The functional film forming composition according to the present invention may be applied by a roll coating method, a gravure roll coating method, an air doctor coating method, a blade coating method, a wire doctor coating method, a knife coating method, a reverse coating method, or a transfer roll. At least one side of the substrate film by coating method, micro gravure coating method, spin coating method, flow coating method, spray coating method, kiss coating method, cast coating method, slot orifice coating method, calendar coating method, die coating method, etc. Can be applied. Among these, a micro gravure coating method that can be uniformly applied as a thin film is preferable.

Moreover, as a curing method after the application of the functional film forming composition, for example, ultraviolet irradiation, heating or the like can be used. In the case of ultraviolet irradiation, a high-pressure mercury lamp, a halogen lamp, a xenon lamp, or the like can be used. The amount of ultraviolet irradiation is usually 100 mJ / cm ² or more and 800 mJ / cm ² or less.

  In addition, when the film thickness of a functional film calculates | requires hard-coat property, if it is 3 micrometers or more, it will become sufficient intensity | strength, but the range of 5 micrometers or more and 10 micrometers or less is preferable from coating accuracy and handling. This is because if the thickness is 10 μm or more, warpage, distortion, and bending of the substrate due to curing shrinkage occur. Furthermore, it is very preferable for the hard coat layer to have a film thickness in the range of 5 μm to 7 μm.

<Transparent electrode>
The transparent electrode according to the present invention uses, for example, a metal oxide such as ITO or IZO or a metal foil such as Cu, Ag, Pt, Au, Al, Zn, or Zr formed in a mesh structure by a photolithography method. be able to. It can also be formed by pattern printing with a conductive ink containing a metal powder such as Al or Ag. Among these, ITO is preferable in that it has excellent adhesion to a base film, thin film formability, and transparency. Of metal foils such as Cu, Ag, Pt, Au, Al, Zn, and Zr, Cu is preferable because it is easy to process the mesh structure. In addition, a transparent electrode refers to the electrode which has transparency visually.

  Below, the specific formation method of a transparent electrode can be formed by the process shown to Fig.1 (a)-(e). Hereinafter, ITO will be described as an example of the transparent electrode.

  First, a resist film 3 made of a photosensitive resin composition is formed by coating on ITO formed as a transparent conductive layer 2 on a base film 1, and then a mask for forming an electrode pattern is formed by photolithography. The pattern of the resist film 3 is formed through development, washing, and drying processes. As the resist film 3, a general-purpose dry film type negative resist or casein resist can also be used. At this time, a 3% sodium carbonate aqueous solution or the like is preferable as the developer, but is not particularly limited.

  Next, using an ITO etching solution made of an acidic aqueous solution such as oxalic acid, phosphoric acid, nitric acid, hydrochloric acid, etc., the ITO exposed from the resist pattern is removed by etching, and the remaining resist pattern is peeled off to remove the ITO transparent electrode 2 ′. Can be formed.

  Moreover, as shown in FIG. 2, the extraction wiring 7 and the terminal connection part 6 can be formed simultaneously with formation of said ITO transparent electrode 2 '.

<Adhesive>
The pressure-sensitive adhesive that can be used in the present invention can be used without particular limitation as long as it has transparency. Preferably it can firmly adhere films, etc., is excellent in optical transparency, exhibits adhesive properties such as moderate wettability, cohesiveness and adhesiveness, does not fire even under high temperature and high humidity conditions, In view of excellent weather resistance and heat resistance, an acrylic pressure-sensitive adhesive is preferably used.

  Examples of the acrylic pressure-sensitive adhesive include acrylic polymer, silicone polymer, polyester, polyurethane, polyamide, polyvinyl ether, vinyl acetate / vinyl chloride copolymer, modified polyolefin, epoxy-based, fluorine-based, natural rubber, and synthetic rubber. Those having a base polymer such as a rubber-based polymer can be appropriately selected and used. Also, a drying agent such as barium oxide or calcium oxide can be used for the pressure-sensitive adhesive in order to remove moisture contained in the adhesive layer to such an extent that light transmission is not hindered. Furthermore, in order to control the thickness of the adhesive layer, an inorganic filler of about several percent may be mixed. A touch panel or the like is applied with the adhesive thus produced using a coating device such as a comma coater, printing, a dispenser, or a spray.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in more detail, this invention is not limited only to this Example.

<Example 1>
An ITO film having a thickness of 230 mm was formed on one surface of a rolled PET film having a width of 1,330 mm, a thickness of 100 μm, and a length of 2,000 m by sputtering. Next, a negative resist was applied onto ITO with a thickness of 1.5 μm using a roll coater, and dried at 90 ° C. for 30 minutes to form a resist film. Next, UV is passed through a photomask having a pattern constituting a transparent electrode.
After irradiation with light of about 100 mJ / cm ^2, development processing was performed with a 3% aqueous sodium carbonate solution to form a resist pattern.

  Next, the roll-shaped film on which the resist pattern is formed is immersed in an etching solution in which phosphoric acid / nitric acid / water is mixed at a weight ratio of 60/10/30 at 40 ° C. for 90 seconds to remove the exposed ITO portion. Etching was removed. Thereafter, the remaining resist was immersed in a 5% by weight NaOH aqueous solution at 40 ° C. for 120 seconds to remove the remaining resist, thereby obtaining a film (A) on which a transparent electrode made of ITO was formed. Moreover, it carried out similarly to the film (A), and obtained the film (B).

On the surface side of the film (A) where the transparent electrode is not formed, the following hard coat film-forming resin composition was applied by microgravure so that the film thickness after drying was 6 μm, and after drying, A hard coat film as a functional film was formed by irradiating with an ultraviolet ray of 600 mJ / cm ^{2 with} a high-pressure mercury lamp to be cured.

<Resin composition for forming hard coat film>
・ 100 parts by weight of urethane acrylate (UV-1700B manufactured by Nippon Synthetic Chemical Co., Ltd.)
-10 parts by weight of fine particles (colloidal silica MEK-ST-L average particle size 40 nm 30% MEK solution manufactured by Nissan Chemical Industries, Ltd.)
Photopolymerization initiator (Irgacure 184 manufactured by BASF) 5.0 parts by weight Solvent (methyl ethyl ketone) 100 parts by weight Layered clay mineral 2.0 parts by weight (manufactured by Lucentite STN Corp Chemical)

  Next, an adhesive was applied to the surface of the film (A) on which the transparent electrode was formed with a thickness of 10 μm. Furthermore, the adhesive-coated surface of the film (A) and the surface on which the transparent electrode of the film (B) was formed were bonded together to produce a touch panel film.

<Example 2>
On the hard coat film of the film (A), an antireflection film-forming composition having the following composition was applied by a microgravure coating method so that the coating amount after drying was 0.2 g / cm ^2, and the temperature was 50 Dry for 60 seconds in a hot oven at 0 ° C. Thereafter, a film for a touch panel was obtained in the same manner as in Example 1 except that an antireflection film was formed by irradiating with an ultraviolet ray with an integrated light amount of 300 mJ / cm ² to be cured.

<Antireflection film forming composition>
-Hollow silica fine particles (The solid content of the silica fine particles is a 20 wt% solution; methyl isobutyl ketone, particle diameter 50 nanometers) 70 parts by weight-Pentaerythritol triacrylate (PETA) 30 parts by weight-Photopolymerization initiator (Irgacure 127 (Made by BASF) 3.0 weight part ・ Methyl isobutyl ketone 50 weight part ・ Propylene glycol monomethyl ether (PGME) 50 weight part

<Example 3>
A touch panel film was obtained in the same manner as in Example 1 except that copper (mesh structure) was used as the transparent electrode. In addition, about formation of the said copper (mesh structure), it describes concretely below.

First, a 12 μm thick copper foil and a PET film as a substrate film were laminated with a dry laminator through a 6 μm thick adhesive. Next, the negative resist was applied on the copper foil surface with a film thickness of 6 μm using a roll coater, and dried at 90 ° C. for 30 minutes. Next, UV light was irradiated at about 100 mJ / cm ² through a photomask provided with a stripe pattern having a line width of 15 μm constituting a copper foil mesh portion to be a transparent electrode and an extraction electrode pattern. Thereafter, development processing was performed with a 3% aqueous sodium carbonate solution to form a resist pattern having a line width of 15 μm.

  Next, the exposed portion of the copper foil was removed by etching using ferric chloride solution having a specific gravity of 1.45, and the remaining resist was peeled off to form a transparent electrode having a copper foil mesh structure with a line width of 15 μm. . At the same time, a lead-out wiring and a terminal connection portion were formed on the outer peripheral portion to produce a touch panel film.

<Comparative Example 1>
A film for a touch panel was produced in the same manner as in Example 1 except that the electrodes of the film (A) and the film (B) were opposed to each other and arranged via epoxy beads having a diameter of 30 μm.

<Evaluation>
The film for touch panels obtained in Examples 1 to 3 and Comparative Example 1 was mounted on the surface of the liquid crystal display, and the luminance was measured. The liquid crystal display includes a polarizing plate, a front glass, a color filter, a liquid crystal / electrode / TFT layer, and a back glass. Further, the liquid crystal display is illuminated from the back glass side with a backlight, and the displayed image is visually recognized through the display area and is operated by the touch panel film. The luminance was measured using a color luminance meter (BM-5AS) and evaluated as 500 cd / m ² or more: ◯, less than 500 cd / m ² : x. The results are shown in Table 1 below.

<Comparison result>
As shown in Table 1, the touch panel according to the present invention obtained in Examples 1 to 3 has a panel luminance of 500 cd / m ² or more, whereas the touch panel obtained in Comparative Example 1 has a backlight. Panel light is scattered by the epoxy beads, and the panel brightness is lowered.

  The present invention can be used as a position input device for electronic devices such as smartphones, tablet computers, and car navigation systems.

DESCRIPTION OF SYMBOLS 1 ... Base film 2 ... Transparent conductive layer 2 '... Transparent electrode 3 ... Resist film 4 ... Functional film 5 ... Adhesive 6 ... Terminal connection part 7 ... Extraction wiring 10 ・ ・ Film for touch panel

Claims (7)

  A film having a functional film formed on one side of the first base film and a transparent electrode formed on the other side, and a transparent electrode formed on one side of the second base film A film for a touch panel, wherein the film B is laminated so that the respective transparent electrodes face each other through an adhesive.   The touch panel film according to claim 1, wherein the functional film includes at least a hard coat layer.   A film A comprising a step of forming a functional film on one side of the first base film, a step of forming a transparent electrode on the other side, and a transparent electrode on one side of the second base film A method for producing a film for a touch panel, comprising: a step of laminating a film B comprising a step of forming via an adhesive layer such that the respective transparent electrodes face each other.   4. The touch panel film according to claim 3, wherein the step of forming the transparent electrode includes a step of forming a film of indium tin oxide (ITO) using a sputtering apparatus and etching using an etching apparatus. Production method.   In the step of forming the transparent electrode, an electrode in which a linear pattern having a width of 20 μm or less made of at least one metal material selected from the group consisting of Cu, Ag, Pt, Au, Al, Zn, and Zr is meshed is arranged. It has the process to form, The manufacturing method of the film for touchscreens of Claim 3 characterized by the above-mentioned.   The said metal material is Cu, The manufacturing method of the film for touchscreens of Claim 5 characterized by the above-mentioned.   A touch panel manufactured using the method for manufacturing a film for a touch panel according to claim 3.

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