TW201637842A - Film for stacking transparent conductive layer, manufacturing method thereof and transparent conductive film - Google Patents

Abstract

The present invention provides a film for stacking transparent conductive layer, which is difficult in visually recognizing the transparent conductive film pattern and capable of setting the resistance of the transparent conductive film to a desired value, and has an excellent processing capability in providing a wiring or the like on the surface of a low refractive index layer, and also provides a transparent conductive film that is made by using the film for stacking transparent conductive layer. The film for stacking transparent conductive layer (1) of the present invention comprises a transparent plastic substrate (2) and a low refractive index layer (4) arranged on at least one side of the transparent plastic substrate (2). The film for stacking transparent conductive layer is characterized in that: the refractive index of the low refractive index layer (4) is 1.30 to 1.50; the surface area increment rate of the low refractive index layer (4) is 5% or less; the surface free energy of the low refractive index layer (4) is 25.0 to 100 mJ/m2; the thickness of the low refractive index layer (4) is 2 to 70 nm.

Description

Transparent conductive film laminate film, method for producing the same, and transparent conductive film

The present invention relates to a film for a transparent conductive film laminate, a method for producing the film, and a transparent conductive film produced using the film.

A touch panel capable of inputting information by directly contacting an image display unit is a type of light-transmitting input device disposed on various displays. As a representative form, a resistive touch panel and a capacitive touch can be cited. Control panel.

A transparent conductive film in which a transparent conductive film made of tin-doped indium oxide (ITO) or the like is laminated on a transparent plastic substrate is used for the touch panels.

In the electrostatic capacitance type touch panel, in order to sense the contact position of the finger, after laminating the transparent conductive film, the two transparent conductive films having a linear pattern are arranged such that the transparent conductive films cross each other in a lattice shape. The electrostatic capacitance type touch panel thus obtained has a portion in which a transparent conductive film is laminated and a portion in which no layer is laminated, and the reflectance and the light transmittance are different due to the presence or absence of the transparent conductive film, thereby causing recognition by two pieces of transparency. The lattice pattern of the transparent conductive film formed of the conductive film causes a problem that the visibility of the display is lowered.

In order to make it difficult to recognize the lattice pattern, that is, a portion in which a transparent conductive film is laminated, it is proposed to laminate a high refractive index layer, a low refractive index layer, and a transparent conductive film on a transparent base film (transparent plastic substrate). Film (See Patent Documents 1 and 2).

[Previous Technical Literature] [Patent Literature]

Patent Document 1: Japanese Laid-Open Patent Publication No. 2014-197080

Patent Document 2: Japanese Laid-Open Patent Publication No. 2014-119475

In the transparent conductive film described in Patent Document 1, a high refractive index layer is formed on a transparent plastic substrate by using a composition containing 10 parts by mass of a thermoplastic resin and 12.24 parts by mass of titanium oxide in order to obtain a desired refractive index. Further, a low refractive index layer is formed by using a composition containing 10 parts by mass of the active energy curing resin and 100 parts by mass of the hollow cerium oxide sol (paragraphs 0066, 0069, and 0071 in Patent Document 1). However, in such a transparent conductive film, the resistance value of the transparent conductive film is made higher than a desired value.

Further, in the transparent conductive film described in Patent Document 2, in order to obtain a desired refractive index, a composition containing 58 parts by mass of a polymerizable monomer and 37 parts by mass of a polymerizable oligomer is used in polyparaphenylene. A hard coat layer is formed on the ethylene formate film, and a high refractive index layer is formed thereon by using a composition containing a high refractive index resin, and 60 parts by mass of the polymerizable monomer and 35 parts by mass are used thereon. The composition of the fluorine-containing compound forms a low refractive index layer (paragraphs 0113, 0115, 0118, and 0125 to 0126 in Patent Document 2). However, in such a transparent conductive film, the surface on the opposite side of the high refractive index layer in the low refractive index layer is coated with a silver wiring or the like to form a silver paste, or floats. The adhesion of the formed silver wiring to the surface is lowered. Further, when the adhesive material is bonded to the surface of the low refractive index layer, the adhesion between the surface and the adhesive material is also insufficient.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a pattern in which a transparent conductive film can be easily recognized, and a resistance value of a transparent conductive film can be set to a desired value, and wiring can be provided on the surface of the low refractive index layer. A film for a transparent conductive film laminate which is excellent in workability at the same time, a method for producing the film, and a transparent conductive film produced using the film. Further, in the present specification, the "surface" of the low refractive index layer is not particularly limited, and means a surface on the opposite side of the transparent plastic substrate or the high refractive index layer in the low refractive index layer.

In order to achieve the above object, the present invention provides a film for a transparent conductive film laminate (Invention 1), the transparent conductive film laminate film includes: a transparent plastic substrate; and a low refractive index layer provided on the transparent plastic substrate The film for a transparent conductive film laminate is characterized in that the refractive index of the low refractive index layer is 1.30 to 1.50, and the surface on the opposite side of the transparent plastic substrate in the low refractive index layer is arbitrarily selected to be 4.992 μm. a square area of the square, the surface of the surface of the low refractive index layer corresponding to one side of the square, and the surface of the low refractive index layer corresponding to the other side orthogonal to the one side When the product of the surface length is taken as the actual surface area, the values calculated by the following formula (I) are as follows: The surface area increase rate is 5% or less, the surface free energy of the low refractive index layer is 25.0 to 100 mJ/m ² , and the low refractive index layer has a thickness of 2 to 70 nm.

In the above invention (Invention 1), since the refractive index of the low refractive index layer is sufficiently low, it is difficult to recognize the pattern of the transparent conductive film. Moreover, since the thickness of the low refractive index layer is not too thick, the invisibility of the pattern of the transparent conductive film can be sufficiently ensured. Further, since the smoothness of the surface of the low refractive index layer is sufficiently high, when the surface layer is a transparent conductive film, the resistance value of the transparent conductive film can be set to a desired value. Further, since the surface free energy of the low refractive index layer is sufficiently high, it is possible to suppress the occurrence of floating when the silver paste is applied to the surface of the low refractive index layer, and the adhesion between the surface and the silver wiring is also sufficient. Further, when the adhesive material is bonded to the surface, the adhesion between the surface and the adhesive material is also sufficient.

In the above invention (Invention 1), the low refractive index layer does not contain the particles for refractive index adjustment, or the refractive index is adjusted to be contained in an amount of less than 100 parts by mass based on 100 parts by mass of the matrix resin composition constituting the low refractive index layer. It is preferred to use particles (Invention 2).

In the above inventions (Inventions 1 and 2), it is preferred that a high refractive index layer having a refractive index larger than a refractive index of the low refractive index layer is interposed between the transparent plastic substrate and the low refractive index layer (invention 3).

In the above invention (Invention 3), it is preferred that the refractive index of the high refractive index layer is from 1.60 to 1.90 (Invention 4).

Secondly, the present invention provides a method for producing a film for a transparent conductive film layer, and the method for producing a film for a transparent conductive film layer (Inventions 1 to 4) is characterized in that, when the low refractive index layer is formed, the coating composition is low. After the material of the refractive index layer, the heating is performed at a temperature of 30 to 70 ° C for 10 seconds to 3 minutes. Treatment (Invention 5).

Thirdly, the present invention provides a transparent conductive film characterized by comprising: a film for laminating a transparent conductive film (Inventions 1 to 4); and a transparent conductive film laminated on the opposite side of the transparent plastic substrate in the low refractive index layer. One side of the side (Invention 6).

In the above invention (Invention 6), when the transparent conductive film is etched in the transparent conductive film, the absolute value of the difference in reflectance (%) at a wavelength of 400 nm before and after the etching is preferably 9 or less (Invention 7) ).

According to the present invention, it is possible to provide a pattern in which the transparent conductive film can be easily recognized, and it is possible to set the resistance value of the transparent conductive film to a desired value, and to provide transparency in the processability when wiring or the like is provided on the surface of the low refractive index layer. A film for conducting a conductive film, a method for producing the film, and a transparent conductive film produced using the film.

1‧‧‧Transparent film for transparent conductive film

2‧‧‧Transparent plastic substrate

3‧‧‧High refractive index layer

4‧‧‧Low refractive index layer

10‧‧‧Transparent conductive film

5‧‧‧Transparent conductive film

Fig. 1 is a cross-sectional view showing a film for a transparent conductive film laminate according to an embodiment of the present invention.

Fig. 2 is a cross-sectional view showing a transparent conductive film according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described.

[Thin film for transparent conductive film laminate]

Fig. 1 is a film for a transparent conductive film laminate according to an embodiment of the present invention. Sectional view. The transparent conductive film laminate film 1 of the present embodiment is made of a transparent plastic substrate 2, and a high refractive index layer 3 laminated on one surface (upper side in FIG. 1) of the transparent plastic substrate 2, laminated on a high refractive index layer. The low refractive index layer 4 of the surface (the upper side in FIG. 1) on the opposite side of the transparent plastic base material 2 is comprised.

In the film 1 for a transparent conductive film laminate of the present embodiment, the refractive index of the low refractive index layer 4 is sufficiently low as 1.30 to 1.50, and the refractive index difference of the layers of the low refractive index layer 4 and the low refractive index layer 4 is sufficient. Large, so it is difficult to recognize the pattern of the transparent conductive film. Further, the thickness of the low refractive index layer 4 is 2 to 70 nm, and the thickness is not excessively thick, so that the invisibility of the pattern of the transparent conductive film can be sufficiently ensured. Further, the surface area increase rate of the low refractive index layer 4 is 5% or less, and the smoothness of the surface of the low refractive index layer 4 is sufficiently high. Therefore, when the surface area layer is transparent conductive film, the resistance value of the transparent conductive film can be set. For the expected value. Further, since the surface free energy of the low refractive index layer 4 is sufficiently high as 25.0 to 100.0 mJ/m ² , even if a silver paste or the like is applied to the surface of the low refractive index layer 4, generation of floating can be suppressed and formed. The adhesion of the silver wiring on the surface is also sufficient. Further, when the adhesive material is bonded to the surface, the adhesion between the surface and the adhesive material is also sufficient.

<low refractive index layer>

The low refractive index layer 4 of the thin film 1 for a transparent conductive film laminate of the present embodiment is a layer having a relatively low refractive index. The refractive index of the low refractive index layer 4 is 1.30 to 1.50, preferably 1.32 to 1.48, and particularly preferably 1.34 to 1.47. Since the refractive index of the low refractive index layer 4 is within a predetermined range, the refractive index difference between the low refractive index layer 4 and the high refractive index layer 3 or the transparent plastic substrate 2 in which the low refractive index layer 4 is laminated becomes sufficient, thereby The pattern of the transparent conductive film can be easily recognized. And, if the low refractive index layer 4 When the refractive index is within the above range, it is not necessary to limit the materials that can be used, and the like, and other characteristics such as transparency can be optimized. Further, the refractive index in the present specification is a value measured in the manner shown in the examples.

The surface of the low refractive index layer 4 of the transparent conductive film laminate film 1 of the present embodiment has a relatively high smoothness. Specifically, a square region of 4.992 μm square is arbitrarily selected on the surface on the opposite side of the transparent plastic substrate 2 in the low refractive index layer, and the above surface of the low refractive index layer corresponding to one side of the square is selected. When the product of the surface length and the surface length of the surface of the low refractive index layer corresponding to the other side orthogonal to the one side is the actual surface area, the result calculated by the following formula (I) is as follows: The surface area increase rate is 5% or less, preferably 4.8% or less, and particularly preferably 4.6% or less. Further, the lower limit of the surface area increase rate is 0%, which is preferable to the value. Here, the surface length indicates the length measured along the unevenness existing on the surface. The inventors have found that the smoother the surface of the low refractive index layer 4 is, the higher the resistance value of the transparent conductive film laminated on the surface is. In the film 1 for a transparent conductive film laminate of the present embodiment, the surface area increase rate is 5% or less, so that the smoothness of the surface of the low refractive index layer 4 is sufficiently high, and when the surface layer is a transparent conductive film, the transparent conductive film is The resistance value is maintained at a low value. Therefore, by using the transparent conductive film laminate film 1 of the present embodiment to produce a transparent conductive film, the resistance value of the transparent conductive film can be set to a desired value. In addition, the surface area increase rate in this specification can be measured using a laser microscope or the like which can be observed and the surface shape is measured, and specific measurement conditions are as shown in the test examples described later.

In the film 1 for a transparent conductive film laminate of the present embodiment, the surface free energy of the low refractive index layer 4 is 25.0 to 100.0 mJ/m ² , 28.0 to 70.0 mJ/m ² is preferable, and 30.0 to 60.0 mJ/m ^{2 is} particularly preferable. good. Since the surface free energy of the low refractive index layer 4 is 25.0 to 100.0 mJ/m ² , the workability when wiring or the like is provided on the surface of the low refractive index layer 4 is excellent. In addition, the surface free energy in the present specification is determined by measuring the contact angle of various droplets (dispersion component/dipole component/hydrogen bond component) with respect to the surface of the low refractive index layer 4, and based on this value, by Kitasaki .畑(Kitazaki/Hata) theory to find the person. The contact angle was measured by a contact angle meter (DM-701, manufactured by Kyowa Interface Science Co., Ltd. in the test example), and JIS R3257 was measured by an intravenous drip method. The specific measurement conditions are as shown in the test examples described later.

The thickness of the low refractive index layer 4 in the present embodiment is 2 to 70 nm, preferably 10 to 60 nm, and particularly preferably 20 to 40 nm. Since the thickness of the low refractive index layer 4 is 70 nm or less, the invisibility of the pattern of the transparent conductive film can be ensured. Further, since the thickness of the low refractive index layer 4 is 2 nm or more, the smoothness of the surface of the low refractive index layer 4 can be sufficiently ensured. Further, the thickness of the low refractive index layer 4 in the present specification is a value measured by an ellipsometer, and specific measurement conditions are as shown in the test examples described later.

The material constituting the low refractive index layer 4 of the present embodiment is not particularly limited to those satisfying the above physical properties, and the low refractive index layer 4 is preferably composed of a siloxane compound. As the siloxane compound, an inorganic lanthanoid compound, a polyorganosiloxane compound, and a mixture thereof can be used. The inorganic lanthanide compound contains polydecanoic acid.

When a polyorganosiloxane compound is used as the siloxane compound, it is preferred to use a methyl group having less than two bonds to Si atoms from the viewpoint of obtaining a desired surface free energy.

The oxoxane compound may be produced by a known method, and for example, it may be the following general formula (A), that is, R ¹ _n Si(OR ² ) _4-n (A)

(R ^{1 is} a non-hydrolyzable group, and is an alkyl group or a substituted alkyl group (the substituent is a halogen atom, a hydroxyl group, a thio group, an epoxy group, a (meth) acryloxy group, etc.), an alkenyl group. , aryl or aralkyl, R ² is lower alkyl, n is an integer from 0 to 3. When there are a plurality of R ¹ groups and OR ² groups, respectively, the plurality of R ¹ groups may be the same or different, and plural The OR ² groups may be the same or different. The alkoxydecane compound is obtained by partial or complete hydrolysis using an inorganic acid such as hydrochloric acid or sulfuric acid or an organic acid such as oxalic acid or acetic acid, and is obtained by polycondensation. In order to carry out the reaction, an organic solvent may be used in order to make the hydrolysis uniform, and an appropriate amount of an aluminum compound such as aluminum chloride or trialkoxy aluminum may be used as needed. In addition, the "(meth) propylene fluorenyl group" in this specification means two of an acryloxy group and a methacryloxy group. The same explanation is given for other similar terms.

In the above formula (A), when n = 0, the alkoxydecane compound becomes a tetraalkoxynonane, but by polycondensing the tetraalkoxydecane completely, polyfluorene-based compound can be obtained, whereby an inorganic quinone compound can be obtained by By partial hydrolysis and polycondensation, a polyorganosiloxane compound or a mixture of an inorganic lanthanide compound and a polyorganosiloxane compound can be obtained.

In the above formula (A), when n = 1 to 3, the alkoxydecane compound has a non-hydrolyzable group, which is reduced by partial or complete hydrolysis of the compound. Poly, a polyorganosiloxane compound can be obtained.

Examples of the alkoxydecane compound represented by the above formula (A) include tetramethoxynonane, tetraethoxydecane, tetra-n-propoxydecane, tetraisopropoxydecane, and tetra-n-butyl Oxydecane, tetraisobutoxydecane, tetra-sec-butoxydecane, tetra-tert-butoxydecane, methyltrimethoxydecane, methyltriethoxydecane, methyltripropoxydecane, methyl Triisopropoxy decane, ethyl trimethoxy decane, ethyl triethoxy decane, propyl triethoxy decane, butyl trimethoxy decane, phenyl trimethoxy decane, phenyl triethoxy矽, γ-glycidyl ether propyl trimethoxy decane, γ-propylene methoxy propyl trimethoxy decane, γ-methyl propylene methoxy propyl trimethoxy decane, dimethyl dimethoxy decane , methyl phenyl dimethoxy decane, vinyl trimethoxy decane, vinyl triethoxy decane, divinyl dimethoxy decane, divinyl diethoxy decane, trivinyl methoxy Decane, trivinyl ethoxy decane, and the like. These may be used singly or in combination of two or more.

The oxoxane compound may be obtained by hydrolyzing a hydrazine compound such as sodium metasilicate, sodium orthosilicate or water glass (sodium citrate mixture), in addition to those obtained by the above method. This hydrolysis can cause an acid such as hydrochloric acid, sulfuric acid or nitric acid or a metal compound such as magnesium chloride or potassium sulfate to act to promote the reaction. Free citric acid is formed by the hydrolysis, and a chain-like, cyclic or grid-shaped siloxane compound is obtained by polymerization of the citric acid. Any one of a chain shape, a ring shape, and a mesh shape may be determined depending on the type of the ruthenium compound as a raw material. For example, among the oxoxane compounds obtained from water glass, the following general formula (B) is also known as [Chemical Formula 1] (m represents the degree of polymerization, and R represents a hydrogen atom, a ruthenium atom, or a metal atom such as magnesium or aluminum.) The chain structure is the main component.

Examples of the other examples of the siloxane compound include cerium (SiO _{X .} nH ₂ O) which is an inorganic quinone compound.

The low refractive index layer 4 of the present embodiment can be composed of a cured product obtained by curing a composition containing an active energy ray-curable compound with an active energy ray. Here, the active energy ray-curable compound is a polymerizable compound which has an energy quantum in an electromagnetic wave or a charged particle beam, that is, a crosslinking or curing by irradiation with ultraviolet rays or electron beams. Examples of such an active energy ray-curable compound include a photopolymerizable prepolymer and/or a photopolymerizable monomer.

The photopolymerizable prepolymer has a radical polymerization type and a cationic polymerization type, and examples of the radical polymerization type photopolymerizable prepolymer include a polyester acrylate type, an epoxy acrylate type, and a urethane acrylate type. Polyol acrylate or the like. Here, as the polyester acrylate-based prepolymer, for example, (meth)acrylic acid can be used for the hydroxyl group of the polyester oligomer having a hydroxyl group at both terminals obtained by condensation of a polyvalent carboxylic acid and a polyhydric alcohol. Obtained by esterification or obtained by esterifying a hydroxyl group at the terminal of the oligomer obtained by adding an alkylene oxide to a polyvalent carboxylic acid with (meth)acrylic acid.

The epoxy acrylate-based prepolymer can be obtained, for example, by reacting (meth)acrylic acid with an oxirane ring having a relatively low molecular weight or an oxirane ring of a novolac epoxy resin to obtain a (meth)acrylic acid. Epoxy acrylate prepolymerization An example of the substance is a phenol novolac type prepolymer. The urethane acrylate-based prepolymer can be obtained, for example, by esterifying a polyether polyol or a polyurethane oligomer obtained by a reaction of a polyester polyol and a polyisocyanate with (meth)acrylic acid. Further, the polyol acrylate-based prepolymer can be obtained by esterifying a hydroxyl group of a polyether polyol with (meth)acrylic acid. These photopolymerizable prepolymers may be used alone or in combination of two or more.

On the other hand, an epoxy resin is usually used as the cationic polymerization type photopolymerizable prepolymer. The polyepoxy resin such as a bisphenol resin or a phenol resin is oxidized by a epoxidized compound such as epichlorohydrin, and a linear olefin compound or a cyclic olefin compound is oxidized by a peroxide or the like. And the obtained compound and the like.

Further, examples of the photopolymerizable monomer include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and neopentyl glycol di(methyl). Acrylate, polyethylene glycol di(meth)acrylate, neopentyl glycol adipate di(meth)acrylate, hydroxypivalic acid neopentyl glycol di(meth)acrylate, dicyclopentan Di(meth)acrylate, caprolactone modified dicyclopentyl di(meth)acrylate, ethylene oxide modified di(meth)acrylate, allylated cyclohexyl di(a) Acrylate, isocyanurate di(meth)acrylate, trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propionic acid modified dipentaerythritol tris (a) Acrylate, pentaerythritol tri(meth)acrylate, propylene oxide modified trimethylolpropane tri(meth)acrylate, tris(propylene oxyethyl)isocyanurate, propionic acid modification Dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, caprolactone modified dipentaerythritol hexa(meth) acrylate A multifunctional acrylate such as an ester. Among these acrylates, dipentaerythritol hexaacrylate is preferably used from the viewpoint of easily obtaining desired physical properties of the low refractive index layer 4. These photopolymerizable monomers may be used singly or in combination of two or more kinds, and may be used in combination with the above photopolymerizable prepolymer.

These polymerizable compounds can be used in combination with a photopolymerization initiator as required. The photopolymerization initiator may, for example, be benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin, for the radical polymerization type photopolymerizable prepolymer or photopolymerizable monomer. Isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2 -hydroxy-2-methyl-1-phenylpropyl-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholine Generation-propan-1-one, 4-(2-hydroxyethoxy)phenyl-2(hydroxy-2-propyl)one, benzophenone, p-phenylbenzophenone, 4,4' -diethylaminobenzophenone, dichlorobenzophenone, 2-methyloxime, 2-ethylhydrazine, 2-tert-butylhydrazine, 2-aminopurine, 2-methylthiazide Tons of ketone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzoin dimethyl ketal, benzene Ethyl ketone dimethyl ketal, p-dimethylamino benzoate, and the like. Among them, 1-hydroxycyclohexyl phenyl ketone is preferably used. In addition, examples of the photopolymerization initiator for the cationic polymerization type photopolymerizable prepolymer include anthracene sulfonium ion, aryloxy sulfonium ion, aromatic iodonium ion, etc., tetrafluoroborate, and hexafluorocarbon. A compound composed of an anion such as phosphate, hexafluoroantimonate or hexafluoroarsenate. These may be used alone or in combination of two or more. In addition, the amount thereof is appropriately selected in the range of 0.2 to 10 parts by mass based on 100 parts by mass of the photopolymerizable prepolymer and/or the photopolymerizable monomer.

The low refractive index layer 4 of the present embodiment may contain particles for refractive index adjustment from the viewpoint of achieving a desired refractive index. In particular, when the low refractive index layer 4 of the present embodiment is composed of a composition containing an active energy ray-curable compound, it is preferred to add particles for refractive index adjustment to the composition. Examples of the particles for adjusting the refractive index include cerium oxide sol, porous cerium oxide fine particles, and hollow cerium oxide fine particles.

As the cerium oxide sol having an average particle diameter of about 0.005 to 1 μm, colloidal cerium oxide in which a cerium oxide microparticle of 10 nm to 100 nm is suspended in an organic solvent of an alcoholic or cellosolve type in a colloidal state can be suitably used. Preferably. Further, the average particle diameter can be obtained by a dynamic light scattering method.

Further, the hollow ceria particles or the porous ceria particles have fine voids in the open state or the closed state in the fine particles, and are filled with a gas such as air having a refractive index of 1, so that the fine particles have a low refractive index per se. Characteristics. When the aggregate of the fine particles is not formed in the coating film, when it is uniformly dispersed, the effect of lowering the refractive index of the coating film is increased, and the transparency is excellent. The refractive index of the hollow ceria particles or the porous ceria particles having voids is 1.20 to 1.45, which is lower than that of the general colloidal ceria particles having no voids (refractive index n = 1.46 or so).

The average particle diameter of the hollow ceria particles or the porous ceria particles is about 5 nm to 300 nm, preferably 5 nm to 200 nm, and particularly preferably 10 nm to 100 nm, and the average pore diameter of the void is about 10 nm to 100 nm, and has Hollow ceria particles or porous ceria particles containing air-containing closed cells and/or continuous cells. The refractive index of the entire microparticle is about 1.20 to 1.45. The hollow cerium oxide particles used in the embodiment Since the sub- or porous ceria fine particles are added to the active energy ray-curable compound to form the low refractive index layer 4, even if the refractive index of the cured product of the active energy ray-curable compound is 1.45 or more, the overall refractive index can be lowered. Further, since the hollow ceria particles or the porous ceria particles are dispersed in the low refractive index layer 4, the low refractive index layer 4 is excellent in transparency. Further, the average particle diameter can be obtained by a dynamic light scattering method.

Further, the refractive index adjusting particles may be bonded to an organic compound containing a polymerizable unsaturated group. For example, an organic compound containing a polymerizable unsaturated group may be bonded to the cerium oxide microparticles. The cerium oxide microparticles bonded to the organic compound containing a polymerizable unsaturated group can be obtained by reacting with the stanol group on the stanol group on the surface of the cerium oxide microparticle having an average particle diameter of about 0.005 to 1 μm. It is obtained by reacting a functional group-containing organic compound containing a polymerizable unsaturated group. Examples of the polymerizable unsaturated group include a radical polymerizable acrylonitrile group and a methacryl group.

The mixing ratio of the particles for refractive index adjustment in the low refractive index layer 4 of the present embodiment to the matrix resin composition is appropriately set so that the refractive index and surface area increase rate of the formed low refractive index layer 4 are in the above range. Inside. For example, the particles for refractive index adjustment are preferably less than 100 parts by mass based on 100 parts by mass of the matrix resin composition, more preferably 60 parts by mass or less, more preferably 30 parts by mass or less. However, as described above, it is preferable that the low refractive index layer 4 does not have particles for refractive index adjustment from the viewpoint of achieving excellent smoothness of the surface.

The low refractive index layer 4 in the present embodiment can contain various desired additives within a range that does not impair the effects of the present invention. Examples of the various additives include a dispersant, a dye, a pigment, a crosslinking agent, a curing agent, and an antioxidant.

As the material constituting the low refractive index layer 4 of the present embodiment, the above-described siloxane compound and active energy ray-curable compound can be used in combination. Further, the particles for refractive index adjustment may be added to the above. However, from the viewpoint of easily exhibiting desired physical properties, the low refractive index layer 4 is preferably composed of only a siloxane compound or a combination of an active energy ray-curable compound and particles for refractive index adjustment.

<High refractive index layer>

In the film 1 for a transparent conductive film laminate of the present embodiment, a high refractive index layer 3 having a refractive index larger than that of the low refractive index layer 4 may be interposed between the transparent plastic substrate 2 and the low refractive index layer 4. . At this time, the high refractive index layer 3 is directly laminated on the transparent plastic substrate 2 or laminated on the high refractive index layer via the easy adhesion layer. By providing the high refractive index layer 3, the inconsistency of the pattern of the transparent conductive film can be achieved by the low refractive index layer 4 and the high refractive index layer 3.

The high refractive index layer 3 of the transparent conductive film laminate film 1 of the present embodiment preferably has a refractive index of 1.60 to 1.90, more preferably 1.65 to 1.85, and more preferably 1.68 to 1.80. Since the refractive index of the high refractive index layer 3 is 1.60 to 1.90, the refractive index difference with the low refractive index layer 4 can be sufficiently ensured, and the pattern of the transparent conductive film can be effectively invisible, and this embodiment can be optimized. The physical properties of the thin film 1 for a transparent conductive film laminate in the form of transparency.

The material constituting the high refractive index layer 3 in the present embodiment may, for example, be a thermoplastic resin or an active energy ray-curable compound.

When the high refractive index layer 3 in the present embodiment is formed using a thermoplastic resin, the adhesion between the high refractive index layer 3 containing the thermoplastic resin and the transparent plastic substrate 2 and adhesion to the low refractive index layer 4 Excellent, and its The body plays the same role as the easy-to-back layer.

Specifically, the thermoplastic resin contained in the high refractive index layer 3 has a polarity (or composition) close to the surface of the transparent plastic substrate 2, and exhibits a high affinity with respect to the transparent plastic substrate 2, so that it can be The high refractive index layer 3 is in close contact with the transparent plastic substrate 2. On the other hand, if a material of the low refractive index layer 4 containing an organic solvent is applied onto the high refractive index layer 3, the organic solvent in the material of the low refractive index layer 4 causes the thermoplastic resin in the high refractive index layer 3 Dissolved, and the low refractive index layer 4 can be adhered (fused) to the high refractive index layer 3 by the dissolved thermoplastic resin. Thereby, the layer structure of the film 1 for transparent conductive film lamination can be simplified without separately providing an easy-adhesion layer.

Specific examples of the thermoplastic resin include a polyester resin, a polyurethane resin, an acrylic resin, a polyolefin resin, polyvinyl chloride, polystyrene, polyvinyl alcohol, and polyvinylidene chloride. In particular, at least one selected from the group consisting of a polyester resin, a urethane resin, and an acrylic resin is preferable from the viewpoint of adhesion to the transparent plastic substrate 2 and fusion property with the low refractive index layer 4, and is selected from the group consisting of At least one of the ester resin and the urethane resin is more preferable, and the polyester resin is further preferable.

When the high refractive index layer 3 in the present embodiment is used to form the high refractive index layer 3 in the present embodiment, the active energy ray-curable compound for constituting the low refractive index layer 4 can be used. The composition containing the active energy ray-curable compound is hardened with an active energy ray, whereby the high refractive index layer 3 can be formed. Here, the refractive index of the high refractive index layer 3 needs to be higher than that of the low refractive index layer 4. From the viewpoint of the active energy ray-curable compound used for constituting the low refractive index layer 4, it is preferred to select an aromatic ring and a heterocyclic ring in the molecule, and to form the high refractive index layer 3 Active energy used The amount of the radiation hardening type compound is preferably a group having an aromatic ring and/or a hetero ring in the molecule. Further, for example, by causing the high refractive index layer 3 to contain a metal oxide to be described later, the refractive index of the high refractive index layer 3 can be increased. As a material constituting the high refractive index layer 3, a phenol novolak type prepolymer is preferably used for the active energy ray-curable compound from the viewpoint of easily obtaining desired physical properties of the high refractive index layer 3. Further, the active energy ray-curable compound and the thermoplastic resin may be combined to form the high refractive index layer 3.

The high refractive index layer 3 in the present embodiment contains a material for adjusting the refractive index (hereinafter sometimes referred to as "refractive index adjusting agent"). For example, a metal oxide is preferable. The metal oxide which can be contained in the high refractive index layer 3 is not particularly limited, and examples thereof include titanium oxide, zirconium oxide, hafnium oxide, zinc oxide, indium oxide, antimony oxide, antimony oxide, tin oxide, antimony oxide, and tin-doping. Indium oxide (ITO), antimony doped tin oxide (ATO), and the like. These metal oxides may be used alone or in combination of two or more. Among them, titanium oxide and/or zirconia are preferably used from the viewpoint of refractive index.

It is preferred that the above metal oxide is contained in the high refractive index layer 3 in the form of fine particles. In this case, the average particle diameter of the metal oxide fine particles is preferably 0.005 to 1 μm, more preferably 0.01 to 0.1 μm. In addition, the average particle diameter of the metal oxide fine particles in the present specification is a value measured by a measurement method using zeta potential measurement method.

The compounding ratio of the metal oxide in the high refractive index layer 3 is appropriately set so that the refractive index of the high refractive index layer 3 is within the above range. Specifically, it is preferably about 50 to 1000 parts by mass, more preferably 80 to 800 parts by mass, per 100 parts by mass of the active energy ray-curable compound and/or the thermoplastic resin. 100 to 500 parts by mass is more preferable.

The high refractive index layer 3 in the present embodiment can contain various desired additives within a range that does not impair the effects of the present invention. Examples of the various additives include a dispersant, a dye, a pigment, a crosslinking agent, a curing agent, and an antioxidant.

The high refractive index layer 3 has a thickness of 20 to 150 nm, preferably 30 to 130 nm, more preferably 50 to 110 nm. Since the thickness of the high refractive index layer 3 is in this range, the pattern of the transparent conductive film can be hardly recognized, and the adhesion between the high refractive index layer 3 and the transparent plastic substrate 2 and the low refractive index layer 4 becomes excellent, and The smoothness of the surface of the high refractive index layer 3 becomes sufficient. Further, the thickness of the high refractive index layer 3 in the present specification is a value measured by an ellipsometer, and specific measurement conditions are as shown in the examples below.

<Transparent plastic substrate>

The transparent plastic substrate 2 used in the present embodiment is not particularly limited, and those having a transparency can be suitably selected from known plastic films which are conventional optical substrates. Examples of such a plastic film include a polyester film such as polyethylene terephthalate (PET), polybutylene terephthalate or polyethylene naphthalate (PEN), polyethylene film, and poly Propylene film, cellophane, diacetyl cellulose film, triethylene glycol film, cellulose acetate butyrate film, polyvinyl chloride film, polyvinylidene chloride film, polyvinyl alcohol film, ethylene-vinyl acetate Copolymer film, polystyrene film, polycarbonate film, polymethylpentene film, polysulfone film, polyetheretherketone film, polyether film, polyether quinone film, polyimine film, fluorine A plastic film such as a resin film, a polyamide film, an acrylic resin film, a norbornene resin film, or a cycloolefin resin film, or a laminated film of these.

Among the above films, a polyester film, a polycarbonate film, a polyimide film, a norbornene resin film, a cycloolefin resin film, or the like is preferable because it has strength suitable for a touch panel or the like. Among these, polyester film is particularly preferable from the viewpoints of transparency and thickness precision, and polyethylene terephthalate (PET) is more preferable.

When polyethylene terephthalate (PET) is used as the transparent plastic substrate 2, since PET has excellent adhesion, it is not necessary to provide an easy-adhesion layer for improving adhesion to the high refractive index layer. Further, when the easy-adhesion layer is not provided, PET has a high refractive index of 1.65, and PET can perform its function instead of the high refractive index layer, so that it is not necessary to provide the high refractive index layer 3.

The thickness of the transparent plastic substrate 2 is not particularly limited and may be appropriately selected depending on the application, and is usually 15 to 300 μm, preferably 30 to 250 μm. Further, the transparent plastic substrate 2 can be subjected to surface treatment by an oxidation method, an unevenness method, or the like on one or both sides as needed in order to improve the adhesion between the layers provided on the surface thereof. The oxidation method is, for example, a corona discharge treatment, a chromic acid treatment (wet), a flame treatment, a hot air treatment, an ozone/ultraviolet irradiation treatment, or the like, and a blasting method, a spray treatment method, or the like is used as the unevenness method. These surface treatment methods are appropriately selected depending on the type of the transparent plastic substrate 2, but it is generally preferred to use a corona discharge treatment method in view of effects and workability.

<Manufacture of Thin Film for Transparent Conductive Film Lamination>

The transparent conductive film laminate film 1 can be produced, for example, by the method described below. Here, a production example of the transparent conductive film laminate film 1 in which the high refractive index layer 3 is provided between the low refractive index layer 4 and the transparent plastic substrate 2 will be described. In addition, the low refractive index layer 4 is directly laminated on the transparent plastic substrate 2 In the production example of the transparent conductive film laminate described below, the preparation/forming process of the high refractive index layer 3 is omitted, and other processes are performed in the same manner.

First, a coating agent for a high refractive index layer 3 containing a material constituting the high refractive index layer 3 and an organic solvent is prepared, and a coating agent for a low refractive index layer 4 containing a material constituting the low refractive index layer 4 and an organic solvent is prepared. .

When an active energy ray-curable compound is used as the material constituting the high refractive index layer 3, the organic solvent used for preparing the coating agent for the high refractive index layer 3 is excellent in solubility of the active energy ray-curable compound and the refractive index is adjusted. It is preferred that the dispersibility of the agent is excellent. Specific examples of such an organic solvent include cyclohexanone, methyl ethyl ketone, methyl isobutyl ester, toluene, ethyl acetate, and the like.

On the other hand, when an active energy ray-curable compound is used as the material constituting the low refractive index layer 4, the organic solvent used in the preparation of the coating agent for the low refractive index layer 4 is excellent in solubility of the active energy ray-curable compound. It is preferred that the particles for refractive index adjustment are also excellent in dispersibility. Specific examples of such an organic solvent are the same as the specific examples of the organic solvent in the case where the active energy ray-curable compound is used as the material constituting the high refractive index layer 3.

Further, when the low refractive index layer 4 is composed of a siloxane compound, it is preferred to use an alcohol solvent for the organic solvent used for preparing the coating agent for the low refractive index layer 4 from the viewpoint of solubility and dispersibility. Examples of the alcohol solvent include isopropanol and isobutanol.

After preparing the coating agent for the high refractive index layer 3 and the low refractive index layer 4, first, coating the high refractive index layer 3 on one surface of the transparent plastic substrate 2 Coating agent. Thereafter, the coating agent is dried and irradiated with an active energy ray to harden the coating film, thereby forming the high refractive index layer 3.

Next, a coating agent for the low refractive index layer 4 is applied onto the high refractive index layer 3. When a siloxane compound is used as the material constituting the low refractive index layer 4, the coating agent is dried to form the low refractive index layer 4. On the other hand, when an active energy ray-curable compound is used as the material constituting the low refractive index layer 4, the coating agent is dried and then irradiated with an active energy ray to harden the coating film to form the low refractive index layer 4. The film 1 for a transparent conductive film laminate was obtained by the above method.

Examples of the coating method of the coating agent include a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, and a gravure coating method.

When the low refractive index layer 4 is formed on the high refractive index layer 3, it is preferable to apply a heat treatment (drying treatment) to the low refractive index layer 4 with a coating agent at a temperature of 30 to 70 ° C for about 10 seconds to 3 minutes. When a siloxane compound is used as the material constituting the low refractive index layer 4, after drying, the coating agent is further cured by heating at a temperature of 110 to 150 ° C for about 5 seconds to 3 minutes. When the active energy ray-curable compound is used as the material constituting the low refractive index layer 4, the drying treatment is performed, and then the active energy ray is irradiated to cure the coating agent. As described above, by performing heat treatment (drying treatment) at a temperature of 30 to 70 ° C for about 10 seconds to 3 minutes, it is possible to partially or completely evaporate the solvent before the material of the low refractive index layer 4 is cured, and it is possible to suppress The generation of roughness of the surface of the low refractive index layer 4 caused by evaporation of the solvent.

Ultraviolet rays, electron beams, and the like are usually used as the active energy ray, and ultraviolet rays are particularly preferable. The amount of irradiation of the active energy ray varies depending on the type of the energy ray. For example, when the ultraviolet ray is used, the amount of light is preferably 50 to 1000 mJ/cm ^{2 , more} preferably 100 to 500 mJ/cm ² . Further, in the case of an electron beam, it is preferably about 0.1 to 50 kGy. The ultraviolet irradiation can be performed by a high pressure mercury lamp, a fused H lamp, a xenon lamp, or the like. Further, the electron beam irradiation can be performed by an electron beam accelerator or the like.

The film 1 for a transparent conductive film layer obtained as described above is suitably used as a material for producing a transparent conductive film to be described later.

[Transparent Conductive Film]

Fig. 2 is a cross-sectional view showing a transparent conductive film according to an embodiment of the present invention. The transparent conductive film 10 of the present embodiment is on the opposite side of the high refractive index layer 3 in the low refractive index layer 4 of the transparent conductive film laminate film 1 (the upper side of the low refractive index layer 4 in Fig. 2) Further, a transparent conductive film 5 is laminated. The transparent conductive film 10 is a pattern in which the transparent conductive film 5 is not easily recognized by the presence of the high refractive index layer 3 and the low refractive index layer 4.

<Transparent Conductive Film>

The material of the transparent conductive film 5 in the transparent conductive film 10 of the present embodiment can be used as long as it has a material having both transparency and conductivity, and is not particularly limited, and examples thereof include tin-doped indium oxide (ITO). Cerium oxide (IrO ₂ ), indium oxide (In ₂ O ₃ ), tin oxide (SnO ₂ ), fluorine-doped tin oxide (FTO), indium oxide-zinc oxide (IZO), zinc oxide (ZnO), gallium-doped zinc oxide (GZO), a transparent conductive metal oxide such as aluminum-doped zinc oxide (AZO), molybdenum oxide (MoO ₃ ), or titanium oxide (TiO ₂ ). The thin film of the metal oxide is a transparent conductive film having both transparency and conductivity by adopting appropriate mold-forming conditions.

The thickness of the transparent conductive film 5 is preferably 4 to 800 nm, more preferably 5 to 500 nm, and particularly preferably 10 to 100 nm. The thickness of the transparent conductive film 5 is in the Within the range, it becomes a continuous film and stable conductivity can be obtained without causing a decrease in transparency.

Further, the refractive index of the transparent conductive film 5 is preferably about 1.90 to 2.05.

<physical property>

In the transparent conductive film 10, when the transparent conductive film 5 is etched, the absolute value of the difference in reflectance (%) at a wavelength of 400 nm before and after etching is preferably 9 or less, more preferably 8 or less, and even more preferably 6 or less. Here, the difference in reflectance before and after the etching is the difference between the etching before and after the etching at a wavelength of 400 nm in accordance with JIS K7142 before and after the etching treatment of the transparent conductive film 5, respectively. The value of the quantity.

When the transparent conductive film 5 is etched, the absolute value of the reflectance difference at a wavelength of 400 nm before and after the etching is 9 or less. Therefore, the transparent conductive film 10 of the present embodiment has excellent transparency and is not easily recognized as transparent conductive under reflected light. The pattern of the film 5 is.

<Manufacture of Transparent Conductive Film>

The transparent conductive film 10 of the present embodiment can be produced, for example, by the method described below. First, after the film 1 for a transparent conductive film laminate is produced as described above, a vacuum deposition method, a sputtering method, a CVD method, an ion plating method, a spray method, or a sol-condensation are appropriately selected depending on the type of the material and the required film thickness. In a known method such as a gel method, the transparent conductive film 5 is laminated on the surface of the low refractive index layer 4 on which the thin film 1 for a transparent conductive film layer is provided, whereby the transparent conductive film 10 can be manufactured.

In addition, after the above transparent conductive film 5 is manufactured as above, by light The lithography method forms a resist mask of a predetermined pattern, and an etching process is performed by a known method, whereby a linear pattern or the like can be formed, for example.

In the transparent conductive film 10 of the present embodiment, the transparent conductive film laminate film 1 of the present embodiment is used, and the portion in which the transparent conductive film is laminated can be easily identified, and the resistance value of the transparent conductive film can be set to a desired value. The value is excellent in workability when wiring or the like is provided on the surface of the low refractive index layer.

The embodiments described above are described to facilitate the understanding of the present invention, and are not intended to limit the invention. Therefore, it is intended that all the features and equivalents of the technical scope of the invention are included in the embodiments disclosed herein.

[Examples]

Hereinafter, the present invention will be specifically described by way of Examples and the like, but the scope of the present invention is not limited to the Examples and the like.

Further, the thicknesses of the high refractive index layer and the low refractive index layer in the examples or comparative examples shown below were formed by a spectroscopic ellipsometer (manufactured by JAWOOLLAM Co, product name: M-2000) at the stage of forming the layers. Determination.

[Preparation Example 1] (coating agent H-1 for high refractive index layer)

A phenol novolac-based ultraviolet curable prepolymer (manufactured by Hitachi Chemical Company, Ltd., HITALOID7663, solid content 80%, methyl isobutyl ester (MIBK)) as an active energy ray-curable compound was diluted with MIBK as a diluent solvent. Diluted) 100 parts by mass (solid content conversion; the same applies hereinafter), 300 parts by mass of zirconium oxide having an average particle diameter of 10 nm as a refractive index adjusting agent, and 1-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator (BASF company) Ltd. Manufactured, trade name: Irgacure 184) 5 parts by mass to prepare a coating agent H-1 for a high refractive index layer.

[Preparation Example 2] (coating agent H-2 for high refractive index layer)

A coating agent H-2 for a high refractive index layer was prepared in the same manner as in Production Example 1, except that titanium oxide having an average particle diameter of 10 nm was used as the refractive index adjusting agent.

[Preparation Example 3] (Coating Agent L-1 for Low Refractive Index Layer)

Dipentaerythritol hexaacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name: NK ester A-DPH, solid content 100% by mass) 100 as an active energy ray-curable compound was diluted with MIBK as a diluent solvent. 25 parts by mass of hollow cerium oxide having an average particle diameter of 60 nm as a refractive index adjusting particle, and 1-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator (manufactured by BASF company Ltd., trade name: Irgacure) 184) 5 parts by mass to prepare a coating agent L-1 for a low refractive index layer.

[Preparation Example 4] (Coating Agent L-2 for Low Refractive Index Layer)

Using a isopropyl alcohol (IPA) as a diluent solvent to dilute 100 parts by mass of a decyl alkane resin (manufactured by COLCOAT Co., Ltd., trade name: COLCOAT P) as a siloxane compound, thereby preparing a low refractive index layer Coating agent L-2.

[Preparation Example 5] (Coating agent L-3 for low refractive index layer)

The coating agent L-3 for a low refractive index layer was prepared in the same manner as in Production Example 3 except that the blending amount of the particles for refractive index adjustment was changed to 50 parts by mass.

[Preparation Example 6] (Coating agent L-4 for low refractive index layer)

A coating agent L-4 for a low refractive index layer was prepared in the same manner as in Production Example 3 except that the blending amount of the particles for refractive index adjustment was changed to 12.5 parts by mass.

[Preparation Example 7] (Coating agent L-5 for low refractive index layer)

In addition to changing the blending amount of the particles for refractive index adjustment to 12.5 parts by mass, a reactive fluorine oligomer to be used as an antifouling agent (manufactured by DIC Co., Ltd., trade name: MEGAFACE RS-75, solid content 40%, MIBK) was further added. A coating agent L-5 for a low refractive index layer was prepared in the same manner as in Production Example 3 except for 8.2 parts by mass.

[Preparation Example 8] (coating agent L-6 for low refractive index layer)

A coating agent L-6 for a low refractive index layer was prepared in the same manner as in Production Example 3 except that the particles for refractive index adjustment were not added.

[Preparation Example 9] (coating agent L-7 for low refractive index layer)

A coating agent L-7 for a low refractive index layer was prepared in the same manner as in Production Example 3 except that the amount of the particles for refractive index adjustment was changed to 100 parts by mass.

[Preparation Example 10] (coating agent L-8 for low refractive index layer)

A coating agent L-8 for a low refractive index layer was prepared in the same manner as in Production Example 7, except that the blending amount of the antifouling agent was changed to 11.8 parts by mass.

Here, the blending of Preparation Examples 1 to 10 is shown in Table 1. In addition, the details such as the abbreviations shown in Table 1 are as follows:

[diluting solvent]

MIBK: methyl isobutyl ester

IPA: isopropanol

【Table 1】

[Example 1]

An easy-to-layer layer of a polyethylene terephthalate (PET) film (manufactured by TOYOBO Co., Ltd., trade name: Cosmoshine A4100, thickness: 50 μm) having an easy-to-adhere layer as one of the transparent plastic substrates The surface of the opposite side was coated with the coating agent L-1 for the low refractive index layer obtained in Preparation Example 3 using a Meyer rod. After drying at 50 ° C for 1 minute in an oven, ultraviolet rays of 200 mJ/cm ² were irradiated with a high-pressure mercury lamp under a nitrogen atmosphere to form a low refractive index layer having a thickness of 35 nm to obtain a film for a transparent conductive film laminate. A transparent conductive film having a thickness of 30 nm was formed by sputtering on the low refractive index layer of the obtained film for transparent conductive film laminate using an ITO target (10% by mass of tin oxide) to form a transparent conductive film. Further, the refractive index of the transparent conductive film was 1.95 in accordance with measurement by a spectroscopic ellipsometer described later. Further, the transparent conductive film is formed so as to leave a portion where the transparent conductive film is not laminated, in consideration of the identification test described later.

[Example 2]

A transparent conductive film was produced in the same manner as in Example 1 except that the thickness of the low refractive index layer was changed to 50 nm.

[Example 3]

An easy-to-layer layer of a polyethylene terephthalate (PET) film (manufactured by TOYOBO Co., Ltd., trade name: Cosmoshine A4100, thickness: 50 μm) having an easy-to-adhere layer as one of the transparent plastic substrates The surface of the opposite side was coated with the coating agent L-2 for the low refractive index layer obtained in Preparation Example 4 using a Meyer bar. After drying in an oven at a temperature of 50 ° C for 20 seconds, it was hardened by heating at a temperature of 130 ° C for 40 seconds to form a low refractive index layer having a thickness of 35 nm. Thus, a film for laminating a transparent conductive film was obtained. A transparent conductive film having a thickness of 30 nm was formed by sputtering on the low refractive index layer of the obtained film for transparent conductive film laminate using an ITO target (10% by mass of tin oxide) to form a transparent conductive film. Further, the refractive index of the transparent conductive film was 1.95 based on measurement by a spectroscopic ellipsometer described later. Further, the transparent conductive film is formed so as to leave a portion where the transparent conductive film is not laminated, in consideration of the identification test described later.

[Example 4]

A transparent conductive film was produced in the same manner as in Example 1 except that the coating agent L-3 for a low refractive index layer obtained in Preparation Example 5 was used as a coating agent for a low refractive index layer.

[Example 5]

A transparent conductive film was produced in the same manner as in Example 1 except that the coating agent L-4 for a low refractive index layer obtained in Preparation Example 6 was used as a coating agent for a low refractive index layer.

[Example 6]

A transparent conductive film was produced in the same manner as in Example 1 except that the coating agent L-5 for a low refractive index layer obtained in Preparation Example 7 was used as a coating agent for a low refractive index layer.

[Example 7]

In addition to being used as a transparent plastic substrate, an easy-to-adhere layer having a high refractive index on one side and a polyethylene terephthalate (PET) film having a low interfering layer on the other side (manufactured by MITSUBISHI PLASICS Inc., trade name) : DIAFOIL O 901, having a thickness of 125 μm), and coating a coating agent for a low refractive index layer on the surface of the film having an adhesive layer having high refractive index, A transparent conductive film was produced in the same manner as in Example 1.

[Example 8]

An easy-to-layer layer of a polyethylene terephthalate (PET) film (manufactured by TOYOBO Co., Ltd., trade name: Cosmoshine A4100, thickness: 125 μm) having an easy-to-adhere layer as one of the transparent plastic substrates The surface of the opposite side was coated with the coating agent H-1 for high refractive index layer obtained in Preparation Example 1 using a Meyer bar. After drying at 50 ° C for 1 minute in an oven, ultraviolet rays of 200 mJ/cm ² were irradiated with a high-pressure mercury lamp under a nitrogen atmosphere to form a high refractive index layer having a thickness of 50 nm. Further, the coating agent L-1 for a low refractive index layer obtained in Preparation Example 3 was coated on the high refractive index layer using a Meyer rod. After drying at 50 ° C for 1 minute in an oven, ultraviolet rays of 200 mJ/cm ² were irradiated with a high-pressure mercury lamp under a nitrogen atmosphere to form a low refractive index layer having a thickness of 35 nm, thereby obtaining a film for a transparent conductive film laminate. A transparent conductive film having a thickness of 30 nm was formed by sputtering on the low refractive index layer of the obtained film for transparent conductive film laminate using an ITO target (10% by mass of tin oxide) to form a transparent conductive film. Further, the refractive index of the transparent conductive film was 1.95 based on measurement by a spectroscopic ellipsometer described later. Further, the transparent conductive film is formed so as to leave a portion where the transparent conductive film is not laminated, in consideration of the identification test described later.

[Example 9]

In addition to being used as a transparent plastic substrate, an easy-to-adhere layer having a high refractive index on one side and a polyethylene terephthalate (PET) film having a low interfering layer on the other side (manufactured by MITSUBISHI PLASICS Inc., trade name) :DIAFOIL O 901, thickness 125 μm), and has a high in the film The coating agent for a high refractive index layer is applied to the surface of the refractive index-sensitive adhesive layer, and the coating agent H2 for high refractive index layer obtained in Preparation Example 2 is used as a coating agent for a high refractive index layer. A transparent conductive film was produced in the same manner as in Example 8.

[Comparative Example 1]

A transparent conductive film was produced in the same manner as in Example 1 except that the thickness of the low refractive index layer was changed to 80 nm.

[Comparative Example 2]

A transparent conductive film was produced in the same manner as in Example 1 except that the coating agent L-6 for a low refractive index layer obtained in Preparation Example 8 was used as a coating agent for a low refractive index layer.

[Comparative Example 3]

A transparent conductive film was produced in the same manner as in Example 1 except that the coating agent L-7 for a low refractive index layer obtained in Preparation Example 9 was used as a coating agent for a low refractive index layer.

[Comparative Example 4]

A transparent conductive film was produced in the same manner as in Example 1 except that the coating agent L-8 for a low refractive index layer obtained in Preparation Example 10 was used as a coating agent for a low refractive index layer.

[Test Example 1] (Measurement of refractive index)

The coating agent for a high refractive index layer and the coating agent for a low refractive index layer obtained in Preparation Examples 1 to 10 were respectively applied to polyethylene terephthalate (PET) having an easy adhesion layer on one surface thereof. a film (manufactured by TOYOBO Co., Ltd., trade name: Cosmoshine A4100, thickness: 50 μm) on the opposite side of the easy-adhesion layer, and a low refractive index layer was formed under the same conditions as in the examples and the comparative examples. High refractive index layer.

The obtained low refractive index layer and high refractive index layer were measured by a spectroscopic ellipsometer (manufactured by JAWOOLLAM Co., Ltd., product name: M-2000) under the conditions of a measurement wavelength of 589 nm and a measurement temperature of 23 ° C. Refractive index. In the measurement, the opposite side of the surface on which the low refractive index layer or the high refractive index layer was formed was wiped with a sandpaper, and the measurement was performed by black coating with an oil-based pen (manufactured by ZEBRA Co., Ltd., mack black). A refractive index at a wavelength of 589 nm is used. The results are shown in Table 2.

Further, a polyethylene terephthalate (PET) film having an easy adhesion layer having a high refractive index on one side and an easy adhesion layer having a low interference property on the other side (MITSUBISHI) was measured by the above-described spectroscopic ellipsometer. The refractive index of the easy-adhesion layer manufactured by PLASICS Inc., trade name: DIAFOIL O 901, thickness 125 μm). The results are shown in Table 2.

[Test Example 2] (Measurement of surface area increase rate of low refractive index layer)

For each of the transparent conductive films obtained in the examples and the comparative examples, a low refractive index layer was obtained at a magnification of 900 times using a laser microscopic magnification device (manufactured by KEYENCE Co., Ltd., product name: VK-9700). An image of the face on the opposite side of the transparent plastic substrate.

A square area of 4.992 μm square was arbitrarily selected on the acquired image, and the surface length of the surface of the low refractive index layer corresponding to one side of the square was measured, which was taken as the longitudinal surface length. Further, the surface length of the surface of the low refractive index layer corresponding to the other side orthogonal to the one side was measured, and this was taken as the lateral surface length.

The selection of the square and the measurement of the surface length were carried out twice. Calculate the average value based on the obtained three longitudinal surface lengths, and obtain The average of the three lateral surface lengths is calculated. The product of the average values was taken as the actual surface area, and the surface area increase rate was calculated by the following formula (I). The results are shown in Table 2.

[Test Example 3] (Measurement of Resistance Value of Transparent Conductive Film)

After sputtering on the low refractive index layer of each of the transparent conductive film laminate films obtained in the examples and the comparative examples, the ITO target (tin oxide 10% by mass) was annealed at a temperature of 150 ° C for 30 minutes to form ITO. Crystallization.

The sample was placed on a glass plate, and a resistivity meter (MITSUBISHI CHEMICAL ANALYTECH Co.) equipped with a probe (manufactured by MITSUBISHI CHEMICAL ANALYTECH Co., Ltd., four-probe ASP probe, product name: MCP-TP03P) was used. , manufactured by Ltd., product name: Loresta-AX) to determine the resistance value of the transparent conductive film. The results are shown in Table 2. Further, when the resistance value was 400 Ω/□ or less, it was judged to be good.

[Test Example 4] (Evaluation of invisibility performance)

For each of the transparent conductive films obtained in the examples and the comparative examples, a portion provided with a transparent conductive film and a transparent portion were separately measured by a spectrophotometer (manufactured by SHIMADZU Co., Ltd., product name: UV-3600). The reflectance (単: %) of a portion of the conductive film at a wavelength of 400 nm. The difference in reflectance between the portion where the transparent conductive film is provided and the portion where the transparent conductive film is not provided is calculated, and the absolute value thereof is obtained. The results are shown in Table 2.

Moreover, according to the absolute value of the reflectance difference, the following criteria are used. Evaluate invisibility performance. The evaluation results are shown in Table 2.

○: The absolute value of the reflectance difference is 0~7

△: The absolute value of the reflectance difference is 7~9

×: The absolute value of the reflectance difference exceeds 9

Moreover, the invisibility performance can also be evaluated by the naked eye. Each of the transparent conductive films obtained in the examples and the comparative examples was placed at a position of 1 m from the white fluorescent lamp (27 W; 3 wavelength) so that the transparent conductive film faced the white fluorescent lamp side. In the state where the white fluorescent lamp was projected onto the transparent conductive film, the end portion of the transparent conductive film in which the transparent conductive film was laminated was visually observed from a position at a distance of 30 cm from the transparent conductive film on the same side where the white fluorescent lamp was provided. . Thereafter, the boundary between the portion where the transparent conductive film was laminated and the portion where the transparent conductive film was not laminated (the boundary of the transparent conductive film) was evaluated as follows according to the following criteria. The results are shown in Table 2.

○: No change in color tone was observed at the boundary of the presence or absence of the transparent conductive film.

△: Some color tone is seen at the boundary of the presence or absence of the transparent conductive film.

×: The color tone was observed at the boundary of the presence or absence of the transparent conductive film.

[Test Example 5] (Measurement of surface free energy of low refractive index layer)

With respect to the films for the respective transparent conductive film laminates obtained in the examples and the comparative examples, the contact angles of the various droplets with respect to the surface on which the low refractive index layer was present were measured, and the value was based on the Northakis. The surface free energy (mJ/m ² ) of the low refractive index layer was determined by the Kitazaki-Hata theory. The contact angle was measured by a static drop method in accordance with JIS R3257 using a contact angle meter (manufactured by Kyowa Interface Science Co., Ltd., DM-701). For the droplets, diiodomethane was used as the "dispersion component", 1-bromonaphthalene was used as the "dipole component", and distilled water was used as the "hydrogen bond component". The results are shown in Table 2.

[Test Example 6] (Evaluation of wiring processability of low refractive index layer)

The surface of the transparent conductive film of each of the transparent conductive films obtained in the examples and the comparative examples was screen-printed with silver paste (manufactured by FUJIKURA KASEI Co., Ltd., trade name: FA-401CA), and A silver wiring having a silver paste width of 5 mm and an interval between silver pastes of 0.5 mm was formed. The silver wiring formed was visually evaluated according to the criteria shown below. The results are shown in Table 2.

○: Wiring is formed neatly.

X: Since the floating of the slurry occurs and the end portion has a zigzag shape or the like, the wiring is not formed neatly.

Table 2 shows the structures of Examples 1 to 9 and Comparative Examples 1 to 4 and the measurement results of Test Examples 1 to 6. In addition, the details such as the abbreviations shown in Table 2 are as follows:

[substrate]

Cosmoshine A4100: Polyethylene terephthalate (PET) film having an easy-to-adhere layer on one of the faces (manufactured by TOYOBO Co., Ltd., trade name: Cosmoshine A4100, thickness: 50 μm)

DIAFOIL O 901: a polyethylene terephthalate (PET) film having an easy adhesion layer having a high refractive index on one side and an easy adhesion layer on the other side (manufactured by MITSUBISHI PLASICS Inc., trade name :DIAFOIL O 901, thickness 125μm)

【Table 2】

As is clear from Table 2, the transparent conductive film produced in the examples showed a lower surface area increase rate than the comparative example, and showed a higher surface. Free Energy. Further, in the transparent conductive film produced in the examples, the transparent conductive film has a low electric resistance value and exhibits excellent invisibility, and exhibits excellent wiring workability.

On the other hand, in Comparative Example 1 in which the thickness of the low refractive index layer was thick, the invisibility of the pattern became insufficient. Further, in Comparative Example 2 in which the refractive index of the low refractive index layer was high, the invisibility of the pattern became insufficient. Further, in Comparative Example 3 in which the content of the refractive index adjusting particles in the low refractive index layer is high, the surface area increasing rate of the low refractive index layer is increased, and the resistance value of the transparent conductive layer is increased. Further, in Comparative Example 4 in which the low refractive index layer contains a fluorine-containing compound, the surface free energy was lowered, and wiring workability was deteriorated.

[Industrial availability]

The present invention is suitable for producing a transparent conductive film for an electrostatic capacity type touch panel.

1‧‧‧Transparent film for transparent conductive film

2‧‧‧Transparent plastic substrate

3‧‧‧High refractive index layer

4‧‧‧Low refractive index layer

Claims (7)

A transparent conductive film laminate film comprising: a transparent plastic substrate; and a low refractive index layer disposed on at least one surface side of the transparent plastic substrate, wherein the low refractive index layer has a refractive index of 1.30 to 1.50 a square region of 4.992 μm square is arbitrarily selected on the opposite side of the transparent plastic substrate in the low refractive index layer, and a surface of the surface of the low refractive index layer corresponding to one side of the square is provided When the product of the length and the surface length of the aforementioned surface of the low refractive index layer corresponding to the other side orthogonal to the aforementioned side is taken as the actual surface area, the values calculated by the following formula (I) are as follows: The surface area increase rate is 5% or less, the surface free energy of the low refractive index layer is 25.0 to 100 mJ/m ² , and the low refractive index layer has a thickness of 2 to 70 nm. The film for a transparent conductive film layer according to the first aspect of the invention, wherein the low refractive index layer does not contain particles for refractive index adjustment, or contains less than 100 parts by mass of the matrix resin composition constituting the low refractive index layer. 100 parts by mass of the particles for refractive index adjustment. The film for a transparent conductive film laminate according to the first aspect of the invention, wherein the transparent plastic substrate and the low refractive index layer have a refractive index higher than a refractive index of the low refractive index layer. Refractive index layer. The film for a transparent conductive film laminate according to the third aspect of the invention, wherein the high refractive index layer has a refractive index of 1.60 to 1.90. A film for a transparent conductive film laminate according to any one of claims 1 to 4, which is characterized in that, when the low refractive index layer is formed, the coating composition is formed. After the material of the low refractive index layer, heat treatment is performed at a temperature of 30 to 70 ° C for 10 seconds to 3 minutes. A transparent conductive film, comprising: a film for a transparent conductive film layer according to any one of claims 1 to 4; and a transparent conductive film laminated on the transparent plastic base in the low refractive index layer One side of the opposite side of the material. The transparent conductive film according to claim 6, wherein when the transparent conductive film is etched into the transparent conductive film, the absolute value of the difference in reflectance (%) at a wavelength of 400 nm before and after the etching is 9 or less.