JP2003187643A - Low-transmittance transparent conductive base material and its manufacturing method as well as display device applying this base material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-transmittance transparent conductive base material, and its manufacturing method as well as a display device, with excellent conductivity, low-reflection characteristics, low-transmittance characteristics, and with a good transmitted color, as well as with reduced manufacturing cost. <P>SOLUTION: With the low-transmittance transparent conductive base material composed of a transparent substrate and a transparent membrane, the transparent membrane is structured with a coloring layer, a transparent conductive layer and a transparent coating layer, with an a* value at -10 to +5, a b* value at -10 to +5, of color index in an L*a*b* color model of the transparent membrane (at a standard light source of D65, a visual field angle of 2 degrees) found from transmittance measured for each 5 nm in a visible light range of 380 to 780 nm and a surface resistivity of the transparent membrane at 5×10<SP>3</SP>Ω/(square) or less, reflectance to be minimum in a reflection profile in a visible light range of 380 to 780 nm of less than 2%, a transmittance of 40 to 60%, and a standard deviation of light transmittance excluding the transparent substrate measured for each 5 nm of 7% or less. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a transparent substrate and a transparent film provided on the transparent substrate, and has a low transmissivity transparent conductive film used for a front plate (face panel) of a display device such as a cathode ray tube. In particular, the transparent film is composed of a colored layer, a transparent conductive layer and a transparent coat layer, which are sequentially formed on a transparent substrate, and the conductive property and the low reflection property are preferable for an electric field shield. In addition, it has a low transmission characteristic and a good transmission color of black to bluish black, and also has a low transmittance transparent conductive base material capable of reducing the manufacturing cost, its manufacturing method, and this low transmittance transparent conductive substrate. The present invention relates to a display device to which a material is applied.

[0002]

2. Description of the Related Art Recent office automation (O
Due to the adoption of A) and the spread of Internet communication, many OA devices have been introduced into offices, and it is not uncommon for the environment to face the display of OA devices and work all day. When working in contact with a cathode ray tube (CRT), which is one of the display devices, the display screen is easy to see and does not cause visual fatigue. Also, dust on the front glass (face panel) of the CRT and electric shock are charged. It is hoped that there will be no shock. In addition to this, CR
There is concern that the low-frequency electromagnetic waves generated from T may adversely affect the human body, and such electromagnetic waves do not leak outside C
RT is desired.

By the way, electromagnetic waves are generated from the deflection coil and the flyback transformer, and as the size of the CRT becomes larger, larger electromagnetic waves tend to be generated. Most of the magnetic field leakage can be prevented by changing the shape of the deflection coil. Also, leakage of an electric field can be prevented by forming a conductive transparent film on the outer surface of the face panel. In this case, the electroconductivity of the transparent film is required to be higher than that of the electroconductive film formed for antistatic purposes. That is, the surface resistance is 10 ⁸ for antistatic purposes.
Ω / □ is sufficient, but at least 10 ⁶ Ω / □ or less to prevent leakage electric field (electric field shield),
It is preferably 5 × 10 ³ Ω / □ or less, more preferably 1
It is necessary to form a transparent film having a low resistance of 0 ³ Ω / □ or less.

Several proposals have hitherto been made as a method for forming a conductive transparent film. As one of them, tin oxide, indium oxide, etc. are formed on the outer surface of the face panel by vacuum deposition, CVD, sputtering or the like. There is a method of forming a film of the conductive oxide. Since the transparent film formed by this method is composed of a single composition of tin oxide or indium oxide, the conductivity of the material appears as it is, and a sufficiently low resistance value for the electric field shielding effect can be obtained. Further, the film thickness is sufficiently thin and can be uniformly controlled, and the antireflection treatment is easily performed without impairing the resolution of the CRT.

However, when a method such as vacuum deposition, CVD, or sputtering is used, the atmosphere must be controlled for each CRT, so that a large-scale film forming apparatus is required, and a large amount of transparent film can be formed. Therefore, it is extremely inconvenient for manufacturing a practical CRT. Therefore, these methods are considered unsuitable except for CRTs for special purposes, and there is a demand for a cheaper and faster film forming method.

Under such a technical background, as a material that can realize a low surface resistance at a low cost, an ultrafine indium tin oxide (ITO) powder is used together with a binder of alkyl silicate and N-methyl-2-pyrrolidone. A treatment liquid for electric field shielding, which is dispersed in a polar solvent as a main component, has been proposed (see JP-A-6-279755).

Then, the treatment liquid is applied to the outer surface of the face panel, dried, and then baked at a temperature of 200 ° C. or less to obtain a surface resistance value of 10 ⁴ to 10 ⁶ Ω / □ depending on the film thickness. . The method using this treatment liquid is much simpler than the other methods for forming a conductive transparent film such as a vacuum deposition method and a sputtering method, and the manufacturing cost is low, and the CR
This is an extremely advantageous method for dealing with the electric field shield of T. However, there is a limit to the reduction of the obtained surface resistance value, and there is another aspect that it is difficult to reach the preferable range of 10 ² to 10 ³ Ω / □.

In addition to the above electromagnetic wave leakage prevention measures, in CRTs, in order to make the display screen easier to see, an antiglare treatment is applied to the outer surface of the face panel to suppress the surface reflection of the screen. Anti-glare treatment is also performed by a method of increasing the diffuse reflection of the surface by making fine unevenness on the panel surface, but this method is not a preferable method because the resolution is lowered and the image quality is deteriorated. It is preferable to perform the interference method by controlling the refractive index and the film thickness of the coating so that the reflected light causes destructive interference with the incident light. In order to obtain such low reflectivity, the optical film thickness of the high refractive index film and the low refractive index film is generally (1/4)
λ and (1/4) λ or (1/2) λ and (1/4) λ
The two-layer structure film set in the above is adopted.

In addition to these measures, in a CRT, in order to obtain an image with a good balance of brightness and contrast, the display screen may be darkened to suppress reflection of external light by the phosphor coated on the inner surface of the panel. Done. This is because if the screen is bright, the image becomes whitish and the contrast is reduced. In order to avoid such deterioration of image quality, generally, a panel having a low transmittance is widely adopted, and by forming the above-mentioned two-layer structure film on the outer surface of the panel, a higher quality image can be obtained. There is.

Further, recently, a flat CRT having a flat outer surface of a face panel and improved visibility is rapidly becoming popular. In the flat face panel used for this purpose, the inner surface of the face portion has a curvature in order to obtain a desired mechanical strength, and the thickness of the glass increases from the central portion of the screen toward the peripheral portion. In a panel like this,
A panel with high transmittance is widely used because it causes a difference in brightness between the central portion and the peripheral portion when a panel with low transmittance is used, and image quality deteriorates.If used as is, it depends on the phosphor coated on the inner surface of the panel. There is a drawback that the external light reflection increases and the contrast decreases. In order to obtain a high-contrast image, it is necessary to reduce the amount of light transmitted to the panel itself to suppress reflection of external light. In addition to the above-mentioned conductive and low-reflectivity characteristics, the panel outer surface has low transparency. Attempts have been made to form transparent films.

Further, with respect to the low transparency of the transparent film, not only does the screen become dark, but also the emission intensity balance of red (R), green (G) and blue (B), which are the emission colors of the phosphor, is broken. It is said that a transparent color such as black to bluish black is desirable.

In order to meet these demands, therefore, a method of constructing the transparent film on the transparent substrate with a low-transmittance transparent conductive film having a two-layer structure consisting of a colored conductive layer and a transparent coat layer has been studied. ing.

[0013]

By the way, since the conductive fine particles having high conductivity applied to the colored conductive layer have a light absorption characteristic of the material in the visible light region, they are required for the colored conductive layer. There is a problem that a desired transmission color cannot be obtained.

To solve this problem, it is possible to obtain a desired transmitted color by forming colored conductive layers by mixing colored fine particles that cancel the light absorption peculiar to the above-mentioned conductive fine particles. Since the fine particles impede the conductivity of the colored conductive layer and deteriorate the surface resistance, there is another problem that the conductivity required for the transparent film cannot be obtained.

The present invention has been made by paying attention to such problems, and the problem is that in addition to the conductive property, the low reflection property, and the low transmission property of the transparent film, a good black to blue-black system is obtained. It is an object of the present invention to provide a low-transmissivity transparent conductive base material having various transparent colors and capable of reducing the manufacturing cost, a method for manufacturing the same, and a display device to which the low-transmittance transparent conductive base material is applied.

[0016]

That is, the invention according to claim 1 is premised on a low-transmittance transparent conductive substrate comprising a transparent substrate and a transparent film provided on the transparent substrate. In the above transparent film, the transparent film is composed of a colored layer, a transparent conductive layer and a transparent coat layer which are sequentially formed on a transparent substrate, and which is obtained from the transmittance measured every 5 nm in the visible light region of 380 to 780 nm. L ^* a ^* b ^* color system color index (standard light source D65, viewing angle 2
A ^* value in degrees) is -10 to + 5, b ^* value is in the range of -10 to + 5, and a surface resistance of the transparent film is 5 × 10 ³ Ω / □ or less, the visible light region 380 780n
The minimum reflectance is 2% in the reflection profile of m.
The transmittance is 40 to 60%, and the standard deviation of the light transmittance not including the transparent substrate measured every 5 nm is 7% or less.

The invention according to claim 2 is premised on the low-transmittance transparent conductive substrate according to the invention according to claim 1, wherein the coloring layer contains fine particles of complex oxide or iron containing cobalt and aluminum. The invention according to claim 3 is characterized in that the main component is colored fine particles having an average particle size of 10 to 200 nm and composed of a binder matrix, which are fine particles of complex oxide containing manganese, manganese, and copper, or a mixture of these two kinds. Similarly, on the premise of the low-transmittance transparent conductive substrate according to the invention of claim 1, the transparent conductive layer is mainly composed of conductive fine particles of ruthenium oxide fine particles having an average particle size of 10 to 200 nm and a binder matrix. The invention according to claim 4 is based on the low-transmittance transparent conductive substrate according to the invention according to claim 1, wherein the transparent coat layer is an alkyl group. It is characterized in that a main component Riketo hydrolyzate.

Next, the invention according to claim 5 relates to claims 1 to
Based on the method for producing a low-transmittance transparent conductive substrate according to 4, the coating liquid for forming a colored layer in which colored fine particles are dispersed, the coating liquid for forming a conductive layer in which conductive fine particles are dispersed, and the hydrolysis of an alkyl silicate The coating liquid for forming a transparent coating layer containing the product is sequentially coated on the transparent substrate and dried, and then 100
It is characterized in that the heat treatment is performed at a temperature of 450 ° C.

Further, the invention according to claim 6 is premised on a display device comprising a device body and a front plate arranged on the front side thereof, and the low transmission according to any one of claims 1 to 4 as the front plate. The transparent conductive substrate is incorporated with its transparent substrate side facing the apparatus body side.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below.

First, the low transmissivity transparent conductive substrate according to the present invention comprises a transparent substrate and a transparent film, and the transparent film comprises a colored layer, a transparent conductive layer and a transparent coat layer which are sequentially formed on the transparent substrate. And visible region 380
The a ^* value of the L ^* a ^* b ^* colorimetric color index (standard light source D65, viewing angle 2 degrees) in the transparent film obtained from the transmittance measured every 5 nm at ˜780 nm is −10 to +.
5, b ^* value is in the range of −10 to +5, and the surface resistance value of the transparent film is 5 × 10 ³ Ω / □ or less,
The minimum reflectance in the visible light region 380 to 780 nm reflection profile is less than 2%, and the transmittance is 40 to 6
It is characterized in that the standard deviation of the light transmittance not including the transparent substrate measured at 0% and 5 nm intervals is 7% or less (claim 1).

The transparent film of the low-transmissivity transparent conductive substrate according to the present invention has a three-layer structure of a colored layer, a transparent conductive layer and a transparent coat layer. By separating the colored layer that controls the transmission color and the transparent conductive layer that controls the conductivity, the problem of achieving both the conductivity and the transmission color is solved.

Therefore, the colored fine particles forming the colored layer do not necessarily need to be conductive, and the light absorption of the conductive fine particles forming the transparent conductive layer is canceled to obtain a transmitted color close to black, for example. Is optional.

It is desirable that the colored fine particles and the conductive fine particles each have an average particle diameter of 10 to 200 nm. This is because fine particles having an average particle diameter of 10 nm or less may be difficult to manufacture, and at the same time, they may not be easily dispersed and are not practical when used as a coating material. Also,
This is because if it exceeds 200 nm, scattering of visible light in the formed transparent film becomes large and the haze of the film becomes high, which may be impractical. The average particle size referred to here is the average particle size of primary particles observed with a transmission electron microscope (TEM). Moreover, haze is a phenomenon observed as cloudiness of a transparent substrate, and haze value is a numerical value of the ratio of diffuse transmitted light to the total transmittance. When the haze value is high, it is perceived by the human eye as cloudiness of the transparent base material.

Next, the colored fine particles forming the colored layer and the conductive fine particles forming the transparent conductive layer are claimed in claim 1.
Any material can be applied, provided that it satisfies the requirement of.

Here, the ruthenium oxide fine particles (claim 3) used as the conductive fine particles have high conductivity and coloring power, and are suitable as a material capable of forming a film having low resistance and low permeability. , The transmission color of the film may be green due to its property of absorbing visible light of blue and red.

On the other hand, the complex oxide fine particles containing cobalt and aluminum or the complex oxide fine particles containing iron, manganese and copper (claim 2) used as coloring fine particles have the property of absorbing green visible light. Therefore, for example, by combining the colored layer to which the colored fine particles are applied with the transparent conductive layer to which the ruthenium oxide fine particles are applied, the transmitted color of the film becomes bluish purple.

Here, examples of the above complex oxide containing iron, manganese, and copper include those represented by the chemical formulas (Cu, Fe, M).
n) A compound having a spinel structure represented by (Fe, Mn) ₂ O ₄ may be mentioned.
Those containing 50% by weight and 10 to 40% by weight of copper are preferably used. This complex oxide is a blackening pigment having a high coloring power, and the transmittance of the film can be reduced by adding a small amount of it.

When these colored fine particles are combined with the above-mentioned ruthenium oxide fine particles and made to coexist in a single layer, the light absorption peculiar to the material is canceled out to obtain a desired transmitted color as described above. Since the fine particles have no conductivity, the conductivity of the single layer formed by mixing with ruthenium oxide is hindered and the surface resistance thereof is increased as described above.

On the other hand, the transparent film of the low transmittance transparent electroconductive substrate according to the present invention has a three-layer structure of a colored layer, a transparent electroconductive layer and a transparent coat layer, and coloring for controlling the transmission color. Since the layer and the transparent conductive layer that is responsible for conductivity are separated, it is possible to improve the transmission color of the transparent film without impairing the conductivity of the ruthenium oxide fine particles.

Next, the colored layer forming coating liquid used for forming the colored layer in the method for producing a low transmittance transparent conductive substrate according to the present invention can be produced by the following method.

For example, fine particles of complex oxide containing cobalt and aluminum or fine particles of complex oxide containing iron, manganese, and copper, or fine particles of a mixture of these two types are mixed with a dispersant and a solvent to prepare a paint. After using a device such as a shaker, sand mill, or ultrasonic disperser to perform a dispersion treatment to a particle size of 10 to 200 nm to obtain a uniform dispersion liquid, dilute it with a solvent and a hydrolyzate of an alkyl silicate to color it. It can be obtained as a layer-forming coating liquid.

Similarly, the conductive layer-forming coating liquid used for forming the transparent conductive layer is prepared by mixing, for example, ruthenium oxide fine particles as conductive fine particles with a dispersant and a solvent, and using the above-mentioned dispersing device. It can be manufactured by performing a dispersion treatment to obtain a uniform dispersion liquid with a dispersion particle diameter of 10 to 200 nm, and then diluting this with a solvent.

Next, in the method for producing a low-transmittance transparent conductive substrate according to the present invention, the transparent coating layer-forming coating liquid used for forming the transparent coating layer and the alkyl used for the colored layer-forming coating liquid. hydrolyzate of silicates, commercial ethyl silicate _{28 [Si (OC 2 H5)} 4], methyl silicate _{39 [Si (OCH 3) 4} ], ethyl silicate _{40 [Si n O (n-} 1) (OC 2 H ₅ ) _{(2n + 2)} ], and
Methyl silicate 51 [Si _n O _(n-1) (OCH ₃ )
_{(2n + 2)} ] and other alkyl silicates are mixed and stirred with water, a solvent, and a small amount of acid to obtain a hydrolyzate, which can be diluted with an organic solvent for production. As the acid for promoting the hydrolysis reaction, for example, nitric acid, hydrochloric acid or the like can be used.

The following method can be used to form the above-mentioned transparent film having a three-layer structure of a colored layer, a transparent conductive layer and a transparent coat layer on the transparent substrate.

For example, a transparent substrate such as a glass substrate or a plastic substrate is coated on the transparent substrate such as a spray substrate, a spin coater, a wire bar coater, a doctor blade coater or the like with the above-mentioned coloring layer forming coating liquid or conductive layer forming coating liquid. Liquid and a coating liquid for forming a transparent coating layer are sequentially applied and dried, and then each coating film is cured by heat treatment at a temperature of 100 to 450 ° C. in the atmosphere to form the above transparent film having a three-layer structure. To do.

Regarding the heat treatment temperature of each coating film, when the film is formed on the face panel before vacuum sealing, the temperature can be raised to 450 ° C. just below the glass softening point, but the film formation of the CRT completed sphere after sealing is performed. On the other hand, if the heating temperature is high, there is a risk of explosion. For example, when a hydrolyzate of an alkyl silicate is applied to a coating liquid for forming a transparent coat layer, during the heat treatment, polycondensation of the silicate and evaporation of the solvent component occur, and the coating film shrinks, dries and cures. . The polycondensation reaction of the silicate is completed at 200 to 250 ° C., but if it is 100 ° C. or higher, a considerably strong film can be formed although a small amount of unreacted and unvaporized ink components remain. Generally, a higher temperature is preferable, and especially when the temperature is 250 ° C. or higher, the gel condensation reaction and drying of the silicate are completed, and this further shrinks the film, which increases the packing density of the conductive fine particles and lowers the surface resistance. To do. Further, the contact state between the conductive fine particles is also improved with the evaporation of the solvent component, so that the surface resistance is stabilized and the change with time is improved.

[0038]

EXAMPLES Examples of the present invention will be specifically described below. In the specification, "part" means "part by weight", and the average dispersed particle size means the average particle size measured by using a particle size distribution meter (ELS-800) manufactured by Otsuka Electronics Co., Ltd. ing.

[Example 1] As a composite oxide fine particle containing cobalt and aluminum, TM blue manufactured by Dainichiseika Kogyo Co., Ltd. was used, and 20.0 parts of TM blue, 40.0 parts of water and 19 parts of ethanol were used. After mixing in a ratio of 0.0 part, 3.4 parts of isopropanol and 17.6 parts of a dispersant, dispersion treatment was performed using a ball mill. The average dispersed particle diameter of the TM blue fine particles after the treatment was 113 nm.

This treatment liquid was diluted with ethanol and isopropanol to form a colored layer containing 10.0 parts of TM blue, 20.0 parts of water, 52.0 parts of ethanol, 9.2 parts of isopropanol and 8.8 parts of a dispersant. TM blue dispersion liquid for liquid was prepared (liquid A).

Next, a mixed solution of 19.6 parts of methyl silicate 51 manufactured by Tama Chemical Industry Co., Ltd., 54.8 parts of ethanol, 9.7 parts of isopropanol, and 2.1 parts of water was stirred while stirring. A mixed solution of 0.1 part of 60% nitric acid, 7.9 parts of water, 4.9 parts of ethanol and 0.9 part of isopropanol was added dropwise and stirred for 1 hour to prepare a hydrolyzate of alkyl silicate (solution B). ).

Further, 14.0 parts of ruthenium oxide fine particles manufactured by Sumitomo Metal Mining Co., Ltd., 80.7 diacetone alcohol
Parts and 5.3 parts of the dispersant, and then dispersed using a ball mill. The average dispersed particle diameter of the RuO ₂ fine particles after the treatment was 82 nm. This treatment liquid was diluted with ethanol and isopropanol to give RuO ₂ fine particles of 7.0.
Parts, diacetone alcohol 40.4 parts, ethanol 4
A RuO ₂ dispersion liquid for forming a conductive layer was prepared, which was composed of 2.5 parts, 7.5 parts of isopropanol, and 2.6 parts of a dispersant (C
liquid).

Next, 7.0 parts of the above liquid B, 30.0 parts of propylene glycol monomethyl ether, 15.0 parts of diacetone alcohol, 40.8 parts of ethanol, and 7.2 parts of isopropanol were mixed to form a transparent coat layer. A silicate liquid as a coating liquid for liquid was prepared (liquid D).

Next, 40.0 parts of the above liquid A and liquid 10.0
Part, propylene glycol monomethyl ether 15.0
Parts, 29.7 parts of ethanol, and 5.3 parts of isopropanol were mixed to prepare a coating liquid for forming a colored layer containing 4.00% by weight of TM blue.

Then, this coating solution was applied onto a glass substrate heated to about 40 ° C. by a spin coating method and dried to form a colored layer.

Next, the obtained glass substrate with a colored layer was reheated to about 40 ° C., and 12.7 parts of the liquid C, 10.0 parts of propylene glycol monomethyl ether, 5.0 parts of dimethylformamide were added thereto. RuO ₂ prepared by mixing 61.5 parts of ethanol and 10.8 parts of isopropanol.
A conductive layer-forming coating liquid containing 0.89% by weight of fine particles was applied by a spin coating method and dried.

Subsequently, the liquid D was similarly applied thereon and dried to obtain a low-transmittance transparent conductive substrate having a three-layered transparent film composed of a coloring layer, a conductive layer and a transparent coating layer.

[Example 2] As a composite oxide fine particle of iron, manganese and copper, Dainichi Seika Kogyo Co., Ltd. containing about 3% by weight of iron, about 40% by weight of manganese and about 25% by weight of copper. Using the product name TM Black, TM Black 15.0
Parts, 46.8 parts of water, 21.3 parts of ethanol, 3.7 parts of isopropanol, and 13.2 parts of a dispersant, and the mixture was crushed using a ball mill. The average dispersed particle size of TM black after the treatment was 110 nm.

This treatment solution was diluted with ethanol and isopropanol, and TM black was added in an amount of 10.0 parts and water was added in an amount of 31.2.
Parts, ethanol 42.5 parts, isopropanol 7.5
Parts and 8.8 parts of a dispersant, a concentrated dispersion of TM black was prepared (liquid E).

Next, 21.0 parts of solution A, 0.6 parts of solution E, and B
Liquid 10.0 parts, propylene glycol monomethyl ether 15.0 parts, ethanol 45.4 parts, isopropanol 8.0 parts were mixed in a ratio of TM blue 2.10 wt% and TM black 0.06 wt%. A coating liquid for forming a colored layer was prepared. This coating solution was applied on a glass substrate heated to about 40 ° C. by a spin coating method and dried to form a colored layer.

Next, the obtained glass substrate with a colored layer was reheated to about 40 ° C., and 13.6 parts of the liquid C, 10.0 parts of propylene glycol monomethyl ether and 5.0 parts of dimethylformamide were added thereto. , 60.7 parts of ethanol and 10.7 parts of isopropanol were mixed to prepare RuO.
₂ A conductive layer forming coating liquid containing 0.95% by weight of fine particles was applied by a spin coating method and dried. Subsequently, the liquid D was similarly applied onto it and dried to obtain a low-transmittance transparent conductive substrate having a three-layered transparent film composed of a colored layer, a conductive layer and a transparent coat layer.

Example 3 Solution A 14.0 parts, Solution E 0.9 parts, Solution B 10.0 parts, Propylene glycol monomethyl ether 15.0 parts, Ethanol 51.1 parts, Isopropanol 9.0 parts. To prepare a colored layer forming coating liquid containing 1.40% by weight of TM blue and 0.09% by weight of TM black.

This coating solution was applied on a glass substrate heated to about 40 ° C. by spin coating and dried to form a colored layer.

Next, the obtained glass substrate with a colored layer was reheated to about 40 ° C., and 13.6 parts of C liquid, 10.0 parts of propylene glycol monomethyl ether, 5.0 parts of dimethylformamide were added thereto. RuO prepared by mixing 60.7 parts of ethanol and 10.7 parts of isopropanol
₂ A conductive layer forming coating liquid containing 0.95% by weight of fine particles was applied by a spin coating method and dried.

Subsequently, the liquid D was similarly applied thereon and dried to obtain a low-transmittance transparent conductive substrate having a three-layered transparent coating consisting of a colored layer, a conductive layer and a transparent coating layer. .

Example 4 Liquid A 30.0 parts, Liquid E 1.3 parts, Liquid B 10.0 parts, Propylene glycol monomethyl ether 15.0 parts, Ethanol 37.1 parts, Isopropanol 6.6 parts. Were mixed at a ratio of 3.00% by weight to prepare a coating liquid for forming a colored layer containing TM blue at 3.00% by weight and TM black at 0.13% by weight.

This coating solution was applied onto a glass substrate heated to about 40 ° C. by a spin coating method and dried to form a colored layer.

Next, the obtained glass substrate with a colored layer was reheated to about 40 ° C., and 8.6 parts of C liquid, 10.0 parts of propylene glycol monomethyl ether, 5.0 parts of dimethylformamide, RuO ₂ prepared by mixing 64.9 parts of ethanol and 11.5 parts of isopropanol.
A conductive layer-forming coating liquid containing 0.60% by weight of fine particles was applied by a spin coating method and dried.

Subsequently, the liquid D was similarly applied onto it and dried to obtain a low-transmittance transparent conductive substrate having a three-layered transparent coating consisting of a colored layer, a conductive layer and a transparent coating layer. .

[Comparative Example 1] 12.7 parts of the above liquid C, liquid A 4
0.0 parts, propylene glycol monomethyl ether 1
0.0 parts of dimethylformamide, 5.0 parts of ethanol, 27.5 parts of ethanol, and 4.8 parts of isopropanol were mixed to obtain 0.89% by weight of RuO ₂ fine particles and TM blue 4.00.
A coating liquid for forming a colored conductive layer containing a weight% was prepared.

This coating solution was applied onto a glass substrate heated to about 40 ° C. by a spin coating method and dried, but the particles were aggregated and the colored conductive layer could not be formed.

[Comparative Example 2] 13.6 parts of the above C liquid, A liquid 2
1.0 part, E solution 0.6 part, propylene glycol monomethyl ether 10 parts, dimethylformamide 5 parts, ethanol 42.3 parts, isopropanol 7.5 parts by mixing in a ratio of RuO ₂ fine particles 0.95% by weight, A colored conductive layer forming coating liquid containing 2.10% by weight of TM blue and 0.06% by weight of TM black was prepared.

This coating solution was applied on a glass substrate heated to about 40 ° C. by a spin coating method and dried. Subsequently, the liquid D was similarly applied thereon and dried to obtain a low-transmittance transparent conductive substrate having a two-layered transparent film composed of a colored conductive layer and a transparent coat layer.

[Comparative Example 3] 13.6 parts of the above C liquid, A liquid 1
4.0 parts, E solution 0.9 parts, propylene glycol monomethyl ether 10 parts, dimethylformamide 5 parts, ethanol 48.0 parts, and isopropanol 8.5 parts by mixing in a ratio of RuO ₂ fine particles 0.95% by weight, A colored conductive layer forming coating liquid containing 1.40% by weight of TM blue and 0.09% by weight of TM black was prepared.

This coating solution was applied on a glass substrate heated to about 40 ° C. by a spin coating method and dried. Subsequently, the liquid D was similarly applied thereon and dried to obtain a low-transmittance transparent conductive substrate having a two-layered transparent film composed of a colored conductive layer and a transparent coat layer.

[Comparative Example 4] 8.6 parts of the above C liquid, A liquid 3
0.0 parts, 1.3 parts of E liquid, 10 parts of propylene glycol monomethyl ether, 5 parts of dimethylformamide, 38.3 parts of ethanol, and 6.8 parts of isopropanol, and mixed with RuO ₂ fine particles 0.60% by weight, A colored conductive layer forming coating solution containing 3.00% by weight of TM blue and 0.13% by weight of TM black was prepared.

This coating solution was applied on a glass substrate heated to about 40 ° C. by spin coating and dried. Subsequently, the liquid D was similarly applied thereon and dried to obtain a low-transmittance transparent conductive substrate having a two-layered transparent film composed of a colored conductive layer and a transparent coat layer.

[Comparative Example 5] The above C liquid (15.0 parts), propylene glycol monomethyl ether (10.0 parts), ethanol (63.7 parts) and isopropanol (11.3 parts) were mixed in a ratio of 1.05 parts by weight of RuO ₂ fine particles. % To prepare a conductive layer-forming coating liquid.

This coating solution was applied on a glass substrate heated to about 40 ° C. by spin coating and dried. Subsequently, the liquid D was similarly applied thereon and dried to obtain a low-transmittance transparent conductive substrate having a transparent coating having a two-layer structure composed of a transparent conductive layer and a transparent coat layer.

The low transmittance transparent conductive base material according to each example and the low transmittance transparent conductive base material according to each comparative example thus obtained were heat-treated in an electric furnace, and the film characteristics of the transparent film were measured. .

Table 1 below shows the results of heat treatment at 180 ° C. for 30 minutes, and Table 2 shows the results of heat treatment at 450 ° C. for 30 minutes.

The surface resistance value was measured using a surface resistance meter Loresta AP (MCP-T350) manufactured by Mitsubishi Petrochemical Co., Ltd., and the transmittance and haze value were measured by Murakami Color Research Laboratory haze meter (HR -200). The reflectance including the bottom reflection, the transmitted color index, and the standard deviation of the transmittance were measured using a spectrophotometer (U-4000) manufactured by Hitachi, Ltd. Further, the bottom reflectance means the minimum reflectance in the reflection profile of the low transmittance transparent conductive substrate, and the bottom wavelength means the wavelength at which the reflectance is minimum.

The transmittance and the transmission profile in this specification are obtained as follows by using the transmittance and the transmission profile of a transparent coating having a two-layer structure or a three-layer structure excluding a glass substrate.

Transmittance (%) of transparent film excluding glass substrate
= [(Transmittance including glass substrate) / (transmittance of glass substrate)] x 100 The transmission profile of each low-transmittance transparent conductive substrate thus obtained is shown in Fig. 1 (Example 1 and Comparative Example). (Base material heat-treated at 180 ° C. for 30 minutes according to Example 5), FIG. 3 (base material heat-treated at 180 ° C. for 30 minutes according to Example 2, Comparative Example 2 and Comparative Example 5), FIG. 5 (Example 3, comparison) Base material heat-treated at 180 ° C. for 30 minutes according to Example 3 and Comparative Example 5), FIG. 7 (base material heat-treated at 450 ° C. for 30 minutes according to Example 1 and Comparative Example 5), FIG. 9 (Example 2, comparison) Substrate heat-treated at 450 ° C. for 30 minutes according to Example 2 and Comparative Example 5), FIG. 11 (450 according to Example 3, Comparative Example 3 and Comparative Example 5)
The substrate which was heat-treated at 30 ° C. for 30 minutes) and FIG. 13 (the substrate which was heat-treated at 450 ° C. for 30 minutes according to Example 4, Comparative Example 4 and Comparative Example 5), and the spectrophotometer (U-
4000), the reflection profile of each low-transmissivity transparent conductive base material is shown in FIG. 2 (base material heat-treated at 180 ° C. for 30 minutes according to Example 1 and Comparative Example 5), and FIG. (Base material heat-treated at 180 ° C. for 30 minutes according to Comparative Example 2 and Comparative Example 5), FIG. 6 (base material heat-treated at 180 ° C. for 30 minutes according to Example 3, Comparative Example 3 and Comparative Example 5), FIG. Base material heat-treated at 450 ° C. for 30 minutes according to Example 1 and Comparative Example 5), FIG. 10 (base material heat-treated at 450 ° C. for 30 minutes according to Example 2, Comparative Example 2 and Comparative Example 5),
FIG. 12 (45 according to Example 3, Comparative Example 3 and Comparative Example 5)
14) (base material heat-treated at 0 ° C. for 30 minutes) and FIG. 14 (base material heat-treated at 450 ° C. for 30 minutes according to Example 4, Comparative Example 4, and Comparative Example 5).

[0075]

[Table 1] Note 1: 5 in the visible light wavelength range 380 to 780 nm
It is a value obtained as a standard light source D65 and a viewing angle of 2 degrees from the transmittance excluding the glass substrate measured for each nm.

Note 2: Visible light wavelength region 380 to 780n
It is a value for the transmittance (%) excluding the glass substrate measured every 5 nm in m.

[0077]

[Table 2] Note 1: 5 in the visible light wavelength range 380 to 780 nm
It is a value obtained as a standard light source D65 and a viewing angle of 2 degrees from the transmittance excluding the glass substrate measured for each nm.

Note 2: Visible light wavelength region 380 to 780n
It is a value for the transmittance (%) excluding the glass substrate measured every 5 nm in m.

[Confirmation] (1) As can be seen from the results shown in Table 1 and Table 2, the surface resistance value and the haze value of the low-transmittance transparent conductive base materials having the two-layer structure of Comparative Examples 2 to 4 were confirmed. However, the low-transmissivity transparent conductive substrate having a three-layer structure provided with the colored layer of each example is considered to be preferable for the electric field shield.
It is confirmed that a surface resistance value of 0 ³ Ω / □ or less is obtained, and good haze value and reflection characteristics are obtained.

(2) Further, as can be seen from the results shown in Tables 1 and 2, in the low transmittance transparent conductive substrate of Comparative Example 5, the b ^* value in the transmitted color index exceeded the condition +5. It is confirmed that the desired light transmission color is not obtained.

(3) Further, as can be seen from the numerical values shown in Tables 1 and 2, if the heat treatment after forming the transparent film coating is carried out at a high temperature, a transparent conductive substrate having a low transmittance can be obtained. It is also confirmed that

(4) Further, Tables 1 and 2 and FIGS.
As can be seen from the results shown in Fig. 4, the standard deviation of the transmittance of each Example is smaller than that of Comparative Example 5, and it is confirmed that the light transmission color is improved.

[0083]

According to the low-transmissivity transparent conductive base material of the present invention, a three-layer structure comprising a colored layer, a transparent conductive layer and a transparent coat layer which are sequentially formed on a transparent substrate. The transparent film of 40 to 60% has a low transmittance, has the conductivity which is preferable for the electric field shield and the low reflectivity which suppresses the surface reflection, and has an effect of enabling a better transmitted color. There is.

According to the method for producing a low-transmissivity transparent conductive substrate according to the invention of claim 5, a colored layer forming coating liquid, a conductive layer forming coating liquid, and a transparent coating layer forming are formed on a transparent substrate. The low-transmittance transparent conductive substrate can be obtained simply and at low cost because the low-transmittance transparent conductive substrate can be obtained simply by heat-treating after sequentially applying the coating liquid for coating and drying. It has the effect that it can be manufactured.

Further, according to the display device of the invention described in claim 5, as the front plate, the low-transmissivity transparent conductive base material according to any one of claims 1 to 4 is arranged such that its transparent substrate side is on the device body side. Since it is incorporated so as to face the above, it has an effect that the display device can be provided with low reflectivity for suppressing surface reflection.

[Brief description of drawings]

FIG. 1 shows the results of Example 1 and Comparative Example 5 for 30 at 180 ° C.
The graph figure which shows the transmission profile of the low transmittance transparent electroconductive base material heat-processed for a minute.

FIG. 2 shows the results of Example 1 and Comparative Example 5 at 180 ° C. for 30 minutes.
The graph figure which shows the reflection profile of the low transmittance transparent electroconductive base material heat-processed for a minute.

FIG. 3 shows 18 according to Example 2, Comparative Example 2 and Comparative Example 5;
The graph figure which shows the transmission profile of the low transmittance | permeability transparent conductive base material heat-processed at 0 degreeC for 30 minutes.

FIG. 4 shows 18 according to Example 2, Comparative Example 2 and Comparative Example 5;
The graph which shows the reflection profile of the low transmittance transparent electroconductive base material heat-processed at 0 degreeC for 30 minutes.

FIG. 5 shows 18 according to Example 3, Comparative Example 3 and Comparative Example 5;
The graph figure which shows the transmission profile of the low transmittance | permeability transparent conductive base material heat-processed at 0 degreeC for 30 minutes.

FIG. 6 shows 18 according to Example 3, Comparative Example 3 and Comparative Example 5;
The graph which shows the reflection profile of the low transmittance transparent electroconductive base material heat-processed at 0 degreeC for 30 minutes.

FIG. 7: 30 at 450 ° C. according to Example 1 and Comparative Example 5
The graph figure which shows the transmission profile of the low transmittance transparent electroconductive base material heat-processed for a minute.

FIG. 8: 30 at 450 ° C. according to Example 1 and Comparative Example 5
The graph figure which shows the reflection profile of the low transmittance transparent electroconductive base material heat-processed for a minute.

FIG. 9 shows 45 according to Example 2, Comparative Example 2 and Comparative Example 5.
The graph figure which shows the transmission profile of the low transmittance | permeability transparent conductive base material heat-processed at 0 degreeC for 30 minutes.

FIG. 10 is a graph of 4 according to Example 2, Comparative Example 2 and Comparative Example 5;
The graph figure which shows the reflection profile of the low transmittance transparent electroconductive base material heat-processed at 50 degreeC for 30 minutes.

11 is a diagram relating to Example 3, Comparative Example 3 and Comparative Example 5; FIG.
The graph figure which shows the transmission profile of the low transmittance | permeability transparent conductive base material heat-processed at 50 degreeC for 30 minutes.

FIG. 12 is a graph of 4 according to Example 3, Comparative Example 3 and Comparative Example 5;
The graph figure which shows the reflection profile of the low transmittance transparent electroconductive base material heat-processed at 50 degreeC for 30 minutes.

13 is a diagram relating to Example 4, Comparative Example 4 and Comparative Example 5; FIG.
The graph figure which shows the transmission profile of the low transmittance | permeability transparent conductive base material heat-processed at 50 degreeC for 30 minutes.

14 is a diagram relating to Example 4, Comparative Example 4 and Comparative Example 5; FIG.
The graph figure which shows the reflection profile of the low transmittance transparent electroconductive base material heat-processed at 50 degreeC for 30 minutes.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G02B 1/11 H01B 13/00 503B 5C032 5/22 H01J 9/20 A 5G307 H01B 13/00 503 29/88 5G323 H01J 9/20 G02B 1/10 A 29/88 Z F-term (reference) 2H048 CA01 CA05 CA09 CA14 CA19 CA24 2K009 AA06 BB02 CC03 CC09 CC21 CC42 DD02 DD06 EE01 EE03 4F100 AA17B AA17C AA19B AA23B AG00 AH06D AK01B AK01C AR00B AR00C AR00D AT00A BA02 BA04 BA07 CB00B CB00C CC00D DE01C EH462 EJ422 GB41 JG01C JG04B JL10B JN01A JN01B JN01C JN01D JN06B YY00B 4G059 AA07 AC04 AC08 AC11 EA01 EA05 EA07 EB07 EB09 GA02 GA12 5C028 AA07 AA10 5C032 AA02 DD10 5G307 FA01 FA02 FB01 FC03 FC09 FC10 5G323 BA02 BB01 BB02 BC01

Claims (6)

[Claims] 1. A low-transmittance transparent conductive substrate comprising a transparent substrate and a transparent film provided on the transparent substrate, wherein the transparent film is a colored layer formed in sequence on the transparent substrate.
Along with a transparent conductive layer and a transparent coat layer,
L ^* in the transparent film obtained from the transmittance measured every 5 nm in the visible light region 380 to 780 nm
a ^* b ^* colorimetric color index (standard light source D65, viewing angle 2 degrees) has a ^* value within the range of -10 to +5 and b ^* value of -10 to +5, and the surface of the transparent film Resistance value is 5 × 1
0 ³ Ω / □ or less, the minimum reflectance in the reflection profile in the visible light region 380 to 780 nm is less than 2%,
A low-transmissivity transparent conductive substrate having a transmittance of 40 to 60%, a standard deviation of light transmittance not including a transparent substrate measured every 5 nm of 7% or less. 2. The colored layer, wherein the average particle diameter is 10 to 200 nm, which is composed of composite oxide fine particles containing cobalt and aluminum, or composite oxide fine particles containing iron, manganese, and copper, or a mixture of these two kinds. The low-transmissivity transparent conductive substrate according to claim 1, which comprises colored fine particles and a binder matrix as main components. 3. The transparent conductive layer with low transmittance according to claim 1, wherein the transparent conductive layer is mainly composed of conductive fine particles of ruthenium oxide fine particles having an average particle size of 10 to 200 nm and a binder matrix. Base material. 4. The transparent coating layer contains a hydrolyzate of an alkyl silicate as a main component.
The low-transmittance transparent conductive substrate described. 5. The method for producing a low-transmittance transparent conductive substrate according to any one of claims 1 to 4, wherein a coloring layer-forming coating liquid in which colored fine particles are dispersed, and a conductive layer-forming coating in which conductive fine particles are dispersed. Liquid, a coating liquid for forming a transparent coat layer containing a hydrolyzate of an alkyl silicate, is sequentially applied on the transparent substrate and dried, and then 100 to 4
A method for producing a low-transmissivity transparent conductive substrate, which comprises heat treatment at a temperature of 50 ° C. 6. A display device comprising a device main body and a front plate arranged on the front side thereof, wherein the low transmittance transparent conductive base material according to claim 1 is used as the front plate. A display device characterized in that it is incorporated with the side facing the device body side.