WO2012144323A1

WO2012144323A1 - Optical adjustment film, and transparent conductive film using same

Info

Publication number: WO2012144323A1
Application number: PCT/JP2012/059196
Authority: WO
Inventors: 圭一梶田; 勝紀武藤; 田中　治; 佳弘黒澤; 大治五島
Original assignee: 積水ナノコートテクノロジー株式会社; 東山フイルム株式会社
Priority date: 2011-04-20
Filing date: 2012-04-04
Publication date: 2012-10-26
Also published as: TW201302477A; JP5745037B2; JPWO2012144323A1

Abstract

Provided is an optical adjustment film enabling the manufacture of a transparent conductive film having a patterned transparent conductive layer and high visibility in an advantageous manner. The optical adjustment film comprises a transparent film base material on at least one surface of which a high-refractive index layer and a low-refractive index layer are layered successively from the base material side directly or via one or more functional layers. The optical adjustment film is manufactured such that the minimum value of specular reflectivity at the wavelengths of 200 to 800 nm is given in the wavelength range of 230 to 265 nm.

Description

Optical adjustment film and transparent conductive film using the same

The present invention relates to an optical adjustment film and a transparent conductive film using the same, and in particular, an optical adjustment film advantageously used when producing a transparent conductive film for a touch panel, and a transparent conductive using the same It relates to film.

In recent years, a tablet-type position input device is disposed on the surface of a display device such as a liquid crystal panel, and a finger or the like is displayed at a position where the instruction image is displayed while referring to the instruction image displayed in the image display area There is an increasing number of devices that can input information corresponding to an instruction image by touching. Such an electronic component combining a display device (liquid crystal panel or the like) and a position input device is called a touch panel, and is widely adopted in mobile phones, car navigation, personal computers, various ticket vending machines, bank terminals, etc. ing.

And in the position input device of a touch panel, generally, in order to detect the position inputted into the surface efficiently, the transparent conductive film provided with the transparent conductive layer which has a predetermined pattern shape in the outermost layer is adopted. There is.

Here, in the transparent conductive film, when the transparent conductive layer is patterned, the refractive index of light is different between the portion (pattern portion) where the pattern exists and the portion (pattern opening portion) where the pattern does not exist. There is a risk that the user of the touch panel can recognize the presence of the pattern. The touch panel is to display only the information from the display device correctly, and the situation where the user can recognize the presence of the pattern is not preferable. In particular, in a so-called electrostatic capacitance type touch panel, since a patterned transparent conductive layer is formed on the entire surface of the display unit, it is a transparent conductive film having a patterned transparent conductive layer, What can not be recognized visually by the pattern, that is, a transparent conductive film having excellent visibility is required.

Under such circumstances, in recent years, it is a transparent conductive film having a patterned transparent conductive layer, and various patterns can not be recognized visually by visual recognition (a transparent conductive film having excellent visibility). Have been proposed (see Patent Documents 1 to 6).

However, with the recent advances in display technology for liquid crystal panels and the like, also for transparent conductive films used in position input devices, higher visibility than before is required, and in this respect, conventional transparent In the case of the conductive film, the problem still to be solved is inherent.

JP, 2010-23282, A JP, 2010-27294, A JP 2008-98169 A JP, 2010-15861, A JP, 2009-76432, A JP, 2009-259203, A

Here, the present invention has been made in the background of the above circumstances, and the problem to be solved is that when producing a transparent conductive film by providing a patterned transparent conductive layer, An object of the present invention is to provide an optical adjustment film capable of advantageously producing a film excellent in visibility. Another object of the present invention is to provide a transparent conductive film obtained by using such an optical adjustment film.

And in order to solve such a subject advantageously, the present invention is a high refractive index layer sequentially from the substrate side directly or via one or more functional layers on at least one surface of a transparent film substrate. And an optical adjustment film formed by laminating a low refractive index layer, wherein a minimum value of regular reflectance at a wavelength of 200 to 800 nm is given in a wavelength range of 230 to 265 nm. As its gist.

In such an optical adjustment film according to the present invention, preferably, the average value of the regular reflectance at a wavelength of 400 to 650 nm is 6.16% to 6.90%.

In the optical adjustment film according to the present invention, more preferably, the optical thickness of the high refractive index layer is 59 to 89 nm, and the optical thickness of the low refractive index layer is 40 to 51 nm.

On the other hand, according to the present invention, in the optical adjustment film of each aspect described above, the pattern portion and the pattern opening are provided directly on the surface provided with the high refractive index layer and the low refractive index layer or via one or more functional layers. The gist of the present invention is also a transparent conductive film provided with a transparent conductive layer consisting of parts.

In addition, in this transparent conductive film, Preferably, (DELTA) R calculated by a following formula is 0.5 or less.
ΔR = | R ₁ -R ₂ | ... (formula)
However, R ₁ is a wavelength of 400 to the pattern opening.
R ₂ is the average value of specular reflectance at 650 nm, and R ₂ is the average value of specular reflectance at wavelengths of 400 to 650 nm for the pattern part.

Thus, in the optical adjustment film according to the present invention, the minimum value in the regular reflectance measured at the wavelength within the predetermined range (200 to 800 nm) is given by the wavelength within the range of 230 to 265 nm In the case where a transparent conductive layer comprising a pattern portion and a pattern opening portion is provided on the surface of such an optical adjustment film on which the high refractive index layer and the low refractive index layer are provided to form a transparent conductive film, Such a transparent conductive film has excellent visibility with which the pattern of the transparent conductive layer is hard to be recognized.

It is a fragmentary sectional view of thickness direction which shows an example of the transparent conductive film using the optical adjustment film of this invention.

Hereinafter, the present invention will be described more specifically by referring to the drawings as appropriate.

FIG. 1 schematically shows, in a cross-section in the thickness direction, an example of a representative embodiment of a transparent conductive film using the optical adjustment film according to the present invention. In the optical adjustment film 12, the high refractive index layer 16 and the low refractive index layer 18 are sequentially laminated on one surface of the transparent substrate 14 from the substrate 14, and such an optical adjustment film A transparent conductive layer 20 composed of a pattern opening 20 a and a pattern portion 20 b is provided on the surface of the low refractive index layer 18 in 12, to form a transparent conductive film 10. And, in the present invention, the optical adjustment film 12 is characterized in that the minimum value of the regular reflectance at the wavelength of 200 to 800 nm is given in the range of the wavelength: 230 to 265 nm, a great feature exists. It is difficult for the transparent conductive film 10 provided with the transparent conductive layer 20 including the pattern opening 20a and the pattern portion 20b to have a pattern easily recognized by the optical adjustment film 12 having such characteristics. That is, visibility becomes excellent.

Here, the transparent substrate 14 is generally made of various types of plastic having transparency. The plastic constituting the transparent substrate 14 includes polyester resins, acetate resins, polyethersulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth) acrylic resins, poly Examples of the resin include vinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl alcohol resin, polyarylate resin, polyphenylene sulfide resin and the like. Among them, particularly, polyester resins, polycarbonate resins, polyolefin resins and the like are advantageously used.

The thickness of the transparent substrate 14 is preferably in the range of 2 to 500 μm, and more preferably in the range of 2 to 200 μm. Within this range, it is possible to thin the film while securing the mechanical strength of the entire transparent conductive film.

The high refractive index layer 16 provided on the transparent substrate 14 in FIG. 1 can be formed of various conventionally known materials as long as the object of the present invention is not hindered. For example, inorganic compounds, organic compounds, and mixtures thereof can be used. Specifically, examples of the inorganic compound include zinc oxide, titanium oxide, cerium oxide, aluminum oxide, tantalum oxide, yttrium oxide, ytterbium oxide, zirconium oxide, indium tin oxide and the like. Moreover, when forming the high refractive index layer 16 by the wet coating method mentioned later, it is preferable to use the mixture of the microparticles | fine-particles of the above-mentioned inorganic compound, and a curable monomer and a polymer. Such a curable monomer is not particularly limited, and examples thereof include polyfunctional or monofunctional (meth) acrylate esters, silicon compounds such as tetraethoxysilane, and the like. Moreover, even if it exists in a polymer, it does not specifically limit, A conventionally well-known thing can be used. From the viewpoint of the productivity and the strength of the high refractive index layer 16, a UV curable (photopolymerizable) polyfunctional acrylate monomer is particularly preferably used.

When an inorganic compound is used as fine particles, the average particle size thereof preferably does not exceed the thickness of the high refractive index layer 16, and particularly preferably 100 nm or less. When the average particle size is too large, the transparency of the high refractive index layer 16 may be reduced, for example, due to scattering. In addition, the fine particles may have their surfaces modified with various coupling agents and the like, as necessary. As such a coupling agent, organic substituted silicon compounds, metal alkoxides such as aluminum, titanium, zirconium and antimony, organic acid salts and the like can be exemplified.

Further, the high refractive index layer 16 in the present invention is preferably formed to have an optical film thickness of 59 to 89 nm, more preferably 73 to 77 nm. By thus setting the optical film thickness of the high refractive index layer 16 within a predetermined range, it is possible to more advantageously receive the effects of the present invention. The optical film thickness is calculated by multiplying the physical film thickness and the refractive index.

The low refractive index layer 18 provided on the surface of the high refractive index layer 16 in FIG. 1 does not hinder the object of the present invention, and provides a lower refractive index than that of the high refractive index layer 16. It is possible to form with material. Specifically, inorganic compounds such as silicon oxide (silica), lanthanum fluoride, magnesium fluoride, cerium fluoride, magnesium fluoride, fluorine-containing organic compounds, monofunctional or polyfunctional (meth) acrylic esters, tetra It is possible to use organic compounds such as ethoxysilane, alone or as a mixture thereof. When the low refractive index layer 18 is formed by a wet coating method described later, it is preferable to use a mixture of fine particles of the above-mentioned inorganic compound and a curable monomer or polymer. Such a curable monomer is not particularly limited, but from the viewpoint of the productivity and the strength of the low refractive index layer 18, a UV curable (photopolymerizable) polyfunctional acrylate monomer is particularly preferably used. Be

When an inorganic compound is used as fine particles, the average particle size thereof preferably does not exceed the thickness of the low refractive index layer 18, and particularly preferably 100 nm or less. When the average particle diameter is too large, the transparency of the low refractive index layer 18 may be reduced, for example, due to scattering. In addition, the fine particles may have their surfaces modified with various coupling agents and the like, as necessary. As such a coupling agent, organic substituted silicon compounds, metal alkoxides such as aluminum, titanium, zirconium and antimony, organic acid salts and the like can be exemplified.

The low refractive index layer 18 in the present invention is preferably formed to have an optical film thickness of 40 to 51 nm, more preferably 46 to 51 nm. In particular, a transparent conductive film obtained by using an optical adjustment film in which the optical film thickness of the low refractive index layer 18 is 46 to 51 nm and the optical film thickness of the high refractive index layer 16 is 73 to 77 nm. If it is, better visibility can be exhibited.

The above-mentioned high refractive index layer 16 and low refractive index layer 18 may contain other components in addition to the above-mentioned compounds and the like as long as the object of the present invention is not hindered. Such components include inorganic fillers, inorganic or organic pigments, polymers, polymerization initiators, polymerization inhibitors, polymerization inhibitors, antioxidants, dispersants, surfactants, light stabilizers, light absorbers, leveling agents, etc. It can be illustrated.

Further, as a method of forming the high refractive index layer 16 and the low refractive index layer 18, any conventionally known method such as a dry coating method or a wet coating method can be employed. In the present invention, the wet coating method is preferable from the viewpoint of productivity and economy (low cost). As a wet coating method, a roll coating method, a spin coating method, a dip coating method, etc. are widely known, and among them, a method capable of continuously forming a layer, such as a roll coating method, is particularly useful. It is adopted advantageously from the point of view. In the wet coating method, a liquid material obtained by dispersing the above-described compound or the like in water or an organic solvent or the like is used.

According to the materials and methods described above, the high refractive index layer 16 and the low refractive index layer 18 are sequentially provided on the surface of the transparent substrate 14 from the substrate side, and the optical adjustment film 12 is formed. The selection etc. is comprehensively judged so that the minimum value of the regular reflectance at the wavelength of 200 to 800 nm is given in the range of the wavelength of 230 to 265 nm. That is, since the optical adjustment film 12 of the present invention has characteristic optical properties, the transparent conductive film 10 provided with the patterned transparent conductive layer 20 described later is a transparent conductive layer 20 The pattern is difficult to recognize, that is, it has excellent visibility.

Here, “the minimum value of regular reflectance at a wavelength of 200 to 800 nm is given in the range of wavelength: 230 to 265 nm” means that the regular reflectance at a wavelength of 200 to 800 nm is measured for an optical adjustment film. In this measurement, it means that the measurement wavelength at the time when the regular reflectance becomes the minimum value falls within the range of 230 to 265 nm.

In addition to the optical properties described above, the optical adjustment film 12 preferably has an average specular reflectance of 6.16% to 6.6 at a wavelength of 400 to 650 nm, in order to more advantageously receive the effects of the present invention. It is preferably 90%. The average value of specular reflectance at a wavelength of 400 to 650 nm means the arithmetic mean of specular reflectance measured at a wavelength of 400 to 650 nm.

Then, as shown in FIG. 1, the pattern opening 20a and the pattern 20b are formed on the surface of the low refractive index layer 18 of the optical adjustment film 12 consisting of the transparent base 14, the high refractive index layer 16 and the low refractive index layer 18. The transparent conductive layer 20 which consists of these is provided, and it is set as the transparent conductive film 10.

Here, to form the transparent conductive layer 20 including the pattern opening 20a and the pattern portion 20b, first, the transparent conductive layer 20 'is formed to cover the entire surface of the low refractive index layer 18, and then the transparent conductive layer 20 is formed. A so-called etching method is generally employed, in which the surface of the 'is covered with a partially opened predetermined mask, and a predetermined acid decomposes (dissolves) the transparent conductive layer 20' corresponding to the site where the mask is opened. Ru. Examples of the acid used in the etching include inorganic acids such as hydrochloric acid, sulfuric acid and nitric acid, organic acids such as acetic acid, and mixtures thereof.

The transparent conductive layer 20 (pattern portion 20b) is usually made of indium, tin, zinc, gallium, antimony, titanium, silicon, zirconium, magnesium, aluminum, gold, silver, copper, palladium or tungsten, or their oxides. Configured Among them, those containing indium oxide as a main component such as indium oxide or indium oxide (ITO) containing tin oxide are particularly preferably used from the viewpoint of transparency and conductivity.

In addition, as a method of forming the transparent conductive layer 20 ′ before the pattern opening 20 a is provided, any known method such as a dry coating method or a wet coating method can be employed. The dry coating method may, for example, be a direct current magnetron sputtering method, a sputtering method such as a high frequency magnetron sputtering method or an ion beam sputtering method, a vacuum evaporation method such as electron beam evaporation, an ion plating method or a CVD method.

As described above, in the case of the transparent conductive film obtained by using the optical adjustment film according to the present invention, since the optical adjustment film has a predetermined optical property, the transparent conductive film is patterned on its surface. Even if the conductive layer 20 is provided, the pattern of the transparent conductive layer is difficult to recognize, that is, it has excellent visibility. In particular, a transparent conductive film in which ΔR calculated by the following formula is 0.5 or less is more excellent in visibility, and can be advantageously used in a touch panel or the like.
ΔR = | R ₁ -R ₂ | ... (formula)
However, R ₁ is a wavelength of 400 to the pattern opening.
R ₂ is the average value of specular reflectance at 650 nm, and R ₂ is the average value of specular reflectance at wavelengths of 400 to 650 nm for the pattern part.

As mentioned above, although one representative embodiment of the present invention has been described in detail, it goes without saying that the present invention is not limited to such an embodiment. Specifically, one or more functional layers may be provided between the transparent substrate and the high refractive index layer or between the low refractive index layer and the transparent conductive layer, as long as the object of the present invention is not impaired. It is also possible to provide. As such a functional layer, a layer provided for the purpose of improvement in adhesion, improvement in hardness of the whole film, antiglare, prevention of generation of Newton ring, etc. is exemplified. Such various functional layers can be formed by a conventionally known method.

In the following, some examples of the present invention will be shown to clarify the present invention more specifically, but the present invention is not limited by any description of such examples. Is, of course. In addition to the following embodiments, the present invention also includes various modifications based on the knowledge of those skilled in the art without departing from the spirit of the present invention other than the specific description described above. It should be understood that modifications, improvements, etc. may be added.

In addition, each physical property of the optical adjustment film and the transparent conductive film which were produced in the following Example and comparative example was measured (and calculated) according to the following methods, respectively. The results are shown in Table 1 below.

-Calculation of optical film thickness-
The refractive index and thickness (physical film thickness) of each layer were measured, and the optical film thickness was calculated by multiplying them (refractive index × physical film thickness). The measurement of the refractive index was carried out by using a Abbe refractometer manufactured by Atago Co., Ltd., in such a manner that the measurement light was made incident on each measurement surface, according to a prescribed measurement method indicated by the refractometer. Further, the thickness (physical film thickness) of each layer was calculated using a reflection spectral film thickness meter (trade name: FE-3000) manufactured by Otsuka Electronics Co., Ltd. The optical film thickness of the transparent conductive layer is calculated by the refractive index and the thickness (physical film thickness) in the pattern portion.

-Measurement of minimum specular reflectance wavelength-
Attach the attached 5 ° specular reflection unit to a spectrophotometer (trade name: U4100) manufactured by Hitachi, Ltd., and set the incident angle to 5 ° using a regular reflection mode, at a wavelength of 200 to 800 nm (measurement range) The reflection spectrum was measured, and the wavelength (measurement wavelength) giving the minimum value of the regular reflectance within this measurement range was defined as the minimum regular reflectance wavelength. In the measurement, the back side of the sample was shielded by a black tape in order to eliminate back reflection of the sample and incidence of light from the back side.

-Calculation of average value of regular reflectance-
Attach the attached 5 ° specular reflection unit to a spectrophotometer (trade name: U4100) manufactured by Hitachi, Ltd., and measure the reflection spectrum at a wavelength of 200 to 800 nm using a specular reflection mode with an incident angle of 5 ° Then, the average value (arithmetic average value) of the regular reflectance within the range of 450 to 650 nm was calculated. In the measurement, the back side of the sample was shielded by a black tape in order to eliminate back reflection of the sample and incidence of light from the back side. As for the transparent conductive film was measured for each of the sites of pattern opening portion and the pattern portion, R ₁ (in the pattern openings, Wavelength: The average value of the specular reflectance at 400 ~ 650 nm), and R ₂ ( The wavelength of the pattern portion was calculated as the average value of the regular reflectances at 400 to 650 nm. Furthermore, ΔR was calculated by the following equation.
ΔR = | R ₁ -R ₂ | ... (formula)

First, the following materials were prepared.

-Preparation of hard coat material-
To the photopolymerization agent-containing urethane acrylate oligomer (manufactured by Nippon Kayaku Co., Ltd., trade name: KAYANOVA FOP4000), a mixed solvent obtained by mixing toluene and methyl ethyl ketone (MEK) in a ratio of 5: 5 (weight ratio) is added Thus, a liquid hard coat material (solid content concentration: 30% by weight) was prepared.

-Preparation of material for high refractive index layer-
16 parts by weight of zirconium oxide having an average particle size of 20 to 40 nm, 5 parts by weight of a urethane acrylate oligomer (manufactured by Arakawa Chemical Industries, Ltd., trade name: Beam set 575), and a photopolymerization initiator Mixed solvent (trade name: Irgacure 184, manufactured by Chemicals Co., Ltd.): 3 parts by weight, methyl isobutyl ketone (MIBK) and methyl ethyl ketone (MEK) in a ratio of 5: 5 (weight ratio) A liquid high refractive index layer material (solid content concentration: 5% by weight) was prepared using a MIBK / MEK mixed solvent).

-Preparation of material for low refractive index layer-
100 parts by weight of colloidal silica (Nissan Chemical Co., Ltd., trade name: MEK-ST) having an average particle diameter of 10 to 20 nm and a photopolymerization agent-containing urethane acrylate oligomer (trade name: Orex, manufactured by China Paint Co., Ltd.) A liquid low refractive index layer material (solid content concentration: 5% by weight) was prepared using 20 parts by weight of 344): and a MIBK / MEK mixed solvent.

Using each of the materials thus obtained, optically prepared films and transparent conductive films were produced in accordance with the procedure described below.

-Example 1-
Thickness: A liquid hard coat material is coated by a roll coater on one side of a 125 μm easily adhesive polyester film (made by Toyobo Co., Ltd., trade name: A4300), and the coated film is dried in a dryer oven And dried at 100 ° C. for 1 minute. Next, the coated film after drying was irradiated with ultraviolet light (irradiation amount: 200 mJ / cm ² ) to provide a hard coat having a thickness of about 3 μm on the polyester film. By subjecting the other side of the polyester film to the same operation, a hard coat film in which a hard coat having a thickness of about 3 μm was provided on both sides of the polyester film was obtained.

A liquid high refractive index layer material separately prepared is coated on one side of the obtained hard coat film using a roll coater, and the coated film is dried at 100 ° C. for 1 minute using a dryer oven. It heat-dried on condition of. Next, the coated film after drying is irradiated with ultraviolet light under a nitrogen purge (irradiation amount: 200 mJ / cm ² ) to crosslink the urethane acrylate oligomer contained in the coated film, thereby making the polyester film hard A high refractive index layer was provided on the coat. In addition, the thickness of the coating film which consists of high refractive index layer material was adjusted so that the optical film thickness of the high refractive index layer finally obtained may be set to 85 nm.

In addition, a liquid low refractive index layer material prepared separately is coated on the high refractive index layer using a roll coater, and the coated film is heated at 100 ° C. for 1 minute using a dryer oven. It was dry. Next, the coated film after drying is irradiated with ultraviolet light under nitrogen purge (irradiation amount: 200 mJ / cm ² ) to crosslink the urethane acrylate oligomer contained in the coated film to form a low refractive index layer The optical adjustment film was produced by carrying out. In addition, the thickness of the coating film which consists of low refractive index layer material was adjusted so that the optical film thickness of the low refractive index layer finally obtained may be 40 nm.

Furthermore, a DC magnetron sputtering method is performed using a sintered material comprising 97 wt% of indium oxide and 3 wt% of tin oxide as a target material on the surface of the low refractive index layer which is the outermost layer of the obtained optical adjustment film. A transparent conductive layer was formed to cover the entire surface of the low refractive index layer. Specifically, after evacuating the chamber to 5 × 10 ^-4 Pa or less, a mixed gas of 95% Ar gas and 5% oxygen gas is introduced into the chamber, and the pressure in the chamber is Sputtering was performed at 0.2 to 0.3 Pa. Sputtering was performed so that the optical film thickness of the finally obtained transparent conductive layer would be 50 nm.

Then, after forming a patterned photoresist film on the obtained transparent conductive layer, the whole film is mixed solution of HCl / HNO ₃ / H ₂ O at 25 ° C. [HCl: HNO ₃ : H ₂ O = 20: By immersing in a solution of 1:30 (volume ratio) for 10 minutes, a transparent conductive film having a transparent conductive layer consisting of a pattern opening and a pattern portion on the outermost surface was obtained.

-Example 2-
In the same manner as in Example 1, except that various conditions were changed such that the optical film thickness of the high refractive index layer was 77 nm, and the optical film thickness of the low refractive index layer was 46 nm, Film was obtained.

-Example 3-
In the same manner as in Example 1 except that various conditions were changed such that the optical film thickness of the high refractive index layer was 68 nm, and the optical film thickness of the low refractive index layer was 42 nm, Film was obtained.

-Example 4-
In the same manner as in Example 1 except that various conditions were changed such that the optical film thickness of the high refractive index layer was 78 nm, and the optical film thickness of the low refractive index layer was 40 nm, Film was obtained.

-Example 5
In the same manner as in Example 1 except that various conditions were changed such that the optical film thickness of the high refractive index layer was 89 nm, and the optical film thickness of the low refractive index layer was 46 nm, Film was obtained.

-Example 6-
In the same manner as in Example 1, except that various conditions were changed such that the optical film thickness of the high refractive index layer was 59 nm, and the optical film thickness of the low refractive index layer was 48 nm, Film was obtained.

-Example 7-
In the same manner as in Example 1 except that various conditions were changed such that the optical film thickness of the high refractive index layer was 75 nm, and the optical film thickness of the low refractive index layer was 47 nm, Film was obtained.

-Example 8-
In the same manner as in Example 1 except that various conditions were changed such that the optical film thickness of the high refractive index layer was 73 nm, and the optical film thickness of the low refractive index layer was 47 nm, Film was obtained.

-Example 9-
In the same manner as in Example 1 except that various conditions were changed such that the optical film thickness of the high refractive index layer was 75 nm, and the optical film thickness of the low refractive index layer was 51 nm, Film was obtained.

-Comparative example 1-
In the same manner as in Example 1 except that various conditions were changed such that the optical film thickness of the high refractive index layer was 90 nm, and the optical film thickness of the low refractive index layer was 48 nm, Film was obtained.

-Comparative example 2-
In the same manner as in Example 1, except that various conditions were changed such that the optical film thickness of the high refractive index layer was 69 nm and the optical film thickness of the low refractive index layer was 30 nm, Film was obtained.

The visibility of the eight types of transparent conductive films obtained as described above was evaluated according to the following method.

-Visibility (background color: black)-
The transparent conductive film was placed on the black plate so that the transparent conductive layer side was the outermost surface, and the film was visually observed from the transparent conductive layer side. The case where it was difficult to discriminate between the pattern portion and the pattern opening portion was evaluated as 、, and the case where it was possible to discriminate between the pattern portion and the pattern opening portion was evaluated as x. The evaluation results are shown in Table 1 below.

-Visibility (background color: white)-
The transparent conductive film was placed on the white plate so that the transparent conductive layer side was the outermost surface, and the film was visually observed from the transparent conductive layer side. A case where discrimination between the pattern portion and the pattern opening portion is difficult is 〇, a case where discrimination between the pattern portion and the pattern opening portion is slightly possible by visual angle is △, and discrimination between the pattern portion and the pattern opening portion is The case where possible was evaluated as x. The evaluation results are shown in Table 1 below.

As apparent from Table 1 above, in the case of a transparent conductive film (Examples 1 to 6) in which the optical adjustment film according to the present invention is provided with a transparent conductive layer consisting of a pattern portion and a pattern opening, It is recognized that discrimination between a part and a pattern opening is difficult and the visibility is excellent. In particular, the optical adjustment film was manufactured using an optical thickness of the high refractive index layer in the range of 73 to 77 nm and an optical thickness of the low refractive index layer in the range of 46 to 51 nm. In the case of the transparent conductive film (Example 2, Examples 7 to 9), excellent visibility is observed for both black and white background colors.

10 Transparent conductive film 12 Optical adjustment film 14 Transparent base 16 High refractive index layer 18 Low refractive index layer 20 Transparent conductive layer

Claims

The optical adjustment film is formed by laminating a high refractive index layer and a low refractive index layer sequentially on at least one surface of a transparent film substrate from the substrate side directly or via one or more functional layers. An optical adjustment film characterized in that the minimum value of specular reflectance at 200 to 800 nm is given in the wavelength range of 230 to 265 nm.
The optical adjustment film according to claim 1, wherein the average value of specular reflectance at a wavelength of 400 to 650 nm is 6.16% to 6.90%.
The optical adjustment film according to claim 1 or 2, wherein the optical thickness of the high refractive index layer is 59 to 89 nm, and the optical thickness of the low refractive index layer is 40 to 51 nm.
The pattern according to any one of claims 1 to 3, directly or through one or more functional layers, on the surface provided with the high refractive index layer and the low refractive index layer. The transparent conductive film provided with the transparent conductive layer which consists of a part and a pattern opening part.
The transparent conductive film according to claim 4, wherein ΔR calculated by the following formula is 0.5 or less.
ΔR = | R 1 -R 2 | ... (formula)
Where R 1 is the wavelength of 40 for the pattern opening
R 2 is an average value of specular reflectance at 0 to 650 nm, and R 2 is an average value of specular reflectance at a wavelength of 400 to 650 nm for the pattern part.