JPH1184104A - Conductive antireflection film and cathode ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve productivity and durability and to nearly completely prevent the generation of AEF and the reflection of light by including layers contg. conductive particulates and layers which are disposed to cover these layer and contain SiO2 and the conductive particulates. SOLUTION: A color cathode ray tube has a panel 1 and an enclosure consisting of a funnel 7 integrally joined to this panel 1. A fluorescent surface 9 consisting of tricolor phosphor layers which emit light to blue, green and red and black light absorption layers filling the spacing parts of these tricolor phosphor layers is formed on the inside surface of the face panel 8 built into the panel 1. The conductive antireflection films 2 which comprise a first layer (conductive layer) 14 contg. the particulates 13 of ITO and the second layers 15 dispersed with the particulates 13 of ITO in the matrix of the SiO2 and are so disposed as to cover the first layer 14 by the second layer 15 are formed on the surface of the face panel 8. As a result, the refractive index of the second layer 15 is made smaller than the refractive index of the first layer 14 and the surface resistance value of the second layer 15 is made lower.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a first layer containing conductive fine particles, and a first layer provided to cover the first layer.
a conductive anti-reflection film including iO ₂ and a second layer containing conductive fine particles, and a cathode ray tube anti-reflection film having the conductive anti-reflection film;
The present invention relates to a conductive anti-reflection film for preventing occurrence of an electric field and a cathode ray tube which reduces the reflection of light on the outer surface of a front surface (face panel) of a face plate to thereby prevent the occurrence of AEF.

[0002]

2. Description of the Related Art TV cathode ray tubes and computer C
In a cathode ray tube used for an RT or the like, an electromagnetic wave is generated from the vicinity of an internal electron gun and a deflection yoke.

In recent years, it has been pointed out that such electromagnetic waves may leak to the outside of the cathode ray tube and adversely affect electronic devices and the like arranged in the vicinity.

Therefore, the electromagnetic wave (electric field) is transmitted from the cathode ray tube.
As a method of preventing the leakage of the cathode ray tube, a method of lowering the surface resistance value of the face panel of the cathode ray tube has been proposed.

For example, JP-A-61-118932,
JP-A-61-118946 and JP-A-63-160140 disclose various surface treatment methods for a face panel in order to prevent electrification of the face panel. It has been considered to prevent the generation of an electric field (AEF). As a method for forming a conductive layer having a low surface resistance value on a face panel, there are a PVD method and a CV method.
Vapor phase methods such as D method and sputtering method are conceivable. For example, Japanese Patent Application Laid-Open No. 1-242769 discloses a method for forming a transparent low-resistance conductive layer by a sputtering method.

In general, since the conductive layer has a high refractive index, it is difficult to obtain a sufficient antireflection effect only by the conductive layer. Therefore, the conductive antireflection film usually has a conductive layer covered with, for example, a low-refractive-index antireflection layer containing SiO ₂ in order to achieve both conductivity and prevention of reflection and to protect the conductive layer. Have been done. However, an antireflection layer having a low refractive index containing SiO ₂ has a high surface resistance value,
When the conductive layer is covered with the anti-reflection layer in this way, it is difficult to conduct the anti-reflection layer.

The following method has been proposed as a structure for providing conduction to the antireflection layer of a cathode ray tube.

(1) As shown in FIG. 2, in order to make the conductive layer 3 constituting the conductive anti-reflection film 2 provided on the face panel 8 conductive, the conductive layer penetrates through the anti-reflection layer 4. A special solder 6 is attached by providing a conductive portion 5 leading to 3.

(2) As shown in FIG. 3, a region serving as a conductive portion 5 is provided in the conductive layer 3, and the antireflection layer 4 is not formed in the conductive portion 5.

(3) As shown in FIG. 4, an anti-reflection layer 4 covering the conductive layer 3 is formed to be a porous layer, and the conductive layer 3 is partially exposed to serve as a conductive portion. .

However, if a conductive portion is provided so as to penetrate the anti-reflection layer or solder is attached to the conductive portion in order to conduct the conductive anti-reflection film, the structure of the conductive anti-reflection film becomes complicated. In addition, there is a problem that the productivity of the conductive anti-reflection film is reduced due to an increase in the number of steps in manufacturing.

Further, when the antireflection layer covering the conductive layer is formed as a porous layer, there is a problem that the strength of the antireflection layer is reduced and the durability of the conductive antireflection film is significantly reduced. .

By the way, as a method of forming a conductive layer on a base material such as a face panel, conventionally, a coating method in which conductive oxide fine particles or metal fine particles are dispersed on a base material by a coating method or a wet method. There is known a method in which a liquid is applied to form a coating film, and the coating film is dried, cured or fired to form a conductive layer.

In this method, the refractive index of the layer closest to the substrate is increased, and the refractive index of the layer laminated on the layer is set lower than the refractive index of the layer closest to the substrate. Are changed to form a plurality of layers. That is, in this method, the layer farthest from the substrate has the lowest refractive index.

However, since a layer having a higher conductivity usually has a higher refractive index than a layer having a lower conductivity, when a conductive layer is formed on a layer farthest from the substrate, the function of the conductive anti-reflection film to prevent light from being reflected. Is reduced or lost.

Therefore, for example, SiO ₂ is formed on the conductive layer.
Is provided with an antireflection layer having a low refractive index to prevent light reflection.In this case, since the antireflection layer acts as a capacitor, the surface of the conductive antireflection film has a sufficiently low resistance value. In this case, a conductive portion cannot be formed on the surface of the conductive antireflection film.

[0017]

However, when a conductive portion is provided so as to penetrate the anti-reflection layer or a solder is attached to the conductive portion in order to conduct the conductive anti-reflection film, the conductive anti-reflection film is not provided. There is a problem that the structure of the film becomes complicated, and the number of steps increases during manufacturing, so that the productivity of the conductive antireflection film decreases.

Further, when the antireflection layer covering the conductive layer is formed as a porous layer, there is a problem that the strength of the antireflection layer is reduced and the durability of the conductive antireflection film is significantly reduced. .

Further, in order to form a conductive layer on a base material such as a face panel, a coating solution in which conductive oxide fine particles or metal fine particles are dispersed is applied on the base material to form a coating film. In the method of drying and curing or baking this coating film to form a conductive layer, the layer farthest from the substrate has the lowest refractive index, but usually, a layer having a higher conductivity has a higher refractive index than a layer having a lower conductivity. When a conductive layer is formed on the layer farthest from the substrate,
There is a problem that the function of the conductive anti-reflection film for preventing light reflection is reduced or lost.

Further, when an anti-reflection layer containing SiO ₂ having a low refractive index is provided on the conductive layer to prevent light reflection, the anti-reflection layer acts as a capacitor. There is a problem that the surface of the anti-reflection film cannot have a sufficiently low resistance value, and a conductive portion cannot be formed on the surface of the conductive anti-reflection film as it is.
The present invention has been made in order to solve the above problems, and almost completely prevents the generation of AEF and the reflection of light, can easily conduct electricity from the surface, and is excellent in productivity and durability. It is an object of the present invention to provide a conductive anti-reflection film.

Another object of the present invention is to provide a cathode ray tube having the conductive anti-reflection film and capable of displaying a high quality image for a long period of time.

[0022]

According to the present invention, a layer to be a surface (part farthest from a substrate) of a conductive antireflection film is formed of SiO.
_The presence of the conductive fine particles together with ₂ makes the surface of the conductive anti-reflection film conductive so that a conductive portion can be easily formed on the surface.

That is, the conductive anti-reflection film according to the present invention is provided so as to cover a first layer containing conductive fine particles and a first layer containing SiO ₂ and conductive fine particles. And two layers.

According to the conductive antireflection film of the present invention,
By covering the first layer containing the conductive fine particles with the second layer containing SiO ₂ and the conductive fine particles,
Can be made smaller than the refractive index of the first layer, and the surface resistance of the second layer can be made lower. Therefore, reflection of light is prevented by the second layer, and the second layer
It is possible to conduct electricity directly from this layer.

A cathode ray tube according to the present invention is provided on a face plate having a first face provided with a fluorescent substance, and on a second face opposite to the first face of the face plate,
It is characterized by comprising a first layer containing conductive fine particles, and a second layer provided to cover the first layer and containing SiO ₂ and conductive fine particles.

According to the cathode ray tube according to the present invention, the face plate having the first surface provided with the fluorescent substance has the second surface opposite to the first surface and containing the conductive fine particles on the second surface. Providing a first layer, and covering the first layer with a second layer containing SiO ₂ and conductive fine particles, so that the refractive index of the second layer is smaller than the refractive index of the first layer; and The surface resistance of the second layer can be reduced. Therefore,
The second layer prevents reflection of light and makes it possible to make electrical contact with the second layer at a required conductivity.

In the present invention, the conductive fine particles contained in the first layer and the conductive fine particles contained in the second layer may be the same or different.

Examples of the conductive fine particles used in the present invention include ultrafine particles of at least one substance selected from the group consisting of gold, silver, silver compounds, copper, copper compounds, tin compounds and titanium compounds. . Examples of the silver compound include silver oxide, silver nitrate, silver acetate, silver benzoate, silver bromate, silver bromide, silver carbonate, silver chloride, silver chromate, silver citrate, and silver cyclohexanebutyrate. . In terms of being able to exist in a more stable state in the first and second layers, for example, Ag-Pd, Ag-Pt and A
A silver alloy represented by g-Au is suitable. Examples of the copper compound include copper sulfate, copper nitrate, copper phthalocyanine, and the like. As a tin compound, for example,
ATO and I represented by Sb _x Sn _1-x O ₂ and In _x Sn _1-x O ₂
TO can be given. Further, as the titanium compound, TiN and the like can be mentioned.

As the conductive fine particles, for example, one or more kinds are selected from fine particles made of these substances and used.

The size of the conductive fine particles is preferably as large as possible in view of the improvement in conductivity. However, in consideration of the optical characteristics of the conductive anti-reflection film, the particle size (particles having a sphere having the same volume) can be used. Is 400 nm or less, more preferably
Desirably, it is 50 to 200 nm. If the particle size of the conductive fine particles exceeds 400 nm, the light transmittance of the conductive anti-reflection film will be remarkably reduced, and light will be scattered by the fine particles, and the conductive anti-reflection film will become cloudy. Particle size 400
When a conductive antireflection film formed using conductive fine particles having a size exceeding nm is applied to a cathode ray tube, the resolution of the cathode ray tube may be reduced.

The preferable amount of the conductive fine particles to be contained in the second layer is 5 to 50 weight% with respect to SiO ₂ , that is, the value of conductive fine particles (weight) / SiO ₂ (weight) × 100. %, More preferably 10 to 40% by weight.
When the amount of the conductive fine particles contained in the second layer is less than 5% by weight based on SiO ₂ , the surface resistance of the second layer becomes
There is a possibility that the resistance value may not be as low as that required for establishing conduction with the surface of the conductive antireflection film.

When the amount of the conductive fine particles contained in the second layer exceeds 50% by weight with respect to SiO ₂ , the light reflectance of the conductive anti-reflection film becomes high, and the light reflection becomes insufficient. May be difficult to prevent.

Further, in the present invention, in order to improve the optical characteristics of the conductive antireflection film, pigment ultrafine particles of a dye such as copper phthalocyanine can be present in the first layer. At this time, the particle size of the ultrafine particles of the dye (the value obtained by converting the particles into spheres having the same volume) is 10 to 2
The range is about 00 nm. Further, in order to improve the weather resistance (water resistance, chemical resistance, etc.) of the second layer and increase the reliability of the conductive anti-reflection film, for example, Zr is added to the second layer.
One or more compounds such as O ₂ , fluorinated silanes or silicates can be present depending on environmental conditions and the like. Note that the amount of the compound in the second layer is adjusted so as not to impair the function of the conductive antireflection film. For example, when ZrO ₂ is present in the second layer, the content of ZrO _{2 is 5 to} the content of SiO ₂ , that is, ZrO ₂ (mol) / SiO ₂ (mol) × 100. 40 mol%, more preferably 10 to
20 mol%. When the content of ZrO ₂ in the second layer is less than 5 mol% of SiO ₂ , the effect of ZrO ₂ is hardly obtained. When the content of ZrO ₂ in the second layer exceeds 40 mol% with respect to the content of SiO ₂ ,
The strength of the second layer is reduced. Further, as described above, the second layer may contain ZrO ₂ together with, for example, fluorine silane. In this case, the conductive antireflection film can easily contact the surface with the required conductivity, and can further improve water resistance, acid resistance, alkali resistance, and the like.

In the present invention, as a method of forming the first layer, for example, Ag or Ag may be used together with a nonionic surfactant.
Examples thereof include a method in which a solution in which fine particles such as Cu are dispersed is applied to a base material such as an outer surface of a face panel of a cathode ray tube by a spin coating method, a spraying method or a dipping method. At this time, in order to further suppress the occurrence of unevenness in forming the first layer and obtain a first layer having a uniform film thickness, the temperature of the surface of the base material is set to about 5 to 60 ° C. It is desirable to keep. The thickness of the first layer is determined by the concentration of fine particles of metal such as Ag or Cu contained in the solution, the number of revolutions at the time of coating in the spin coating method, the discharge amount of the dispersion in the spraying method, or the pulling speed in the dipping method. It can be easily controlled by adjusting. In addition, as a solvent of the solution, for example, ethanol, IPA, or the like can be contained together with water as necessary. In addition, an organic metal compound, a pigment, a dye, and the like may be further contained in the solution to add another function to the formed first layer.

As a method of forming the second layer on the first layer, for example, Ag is added together with a nonionic surfactant.
Examples thereof include a method in which a solution in which fine particles such as Cu or Cu and a silicate are dispersed is applied on the first layer by a spin coating method, a spray method, a dipping method, or the like. The thickness of the second layer is
For example, it can be easily controlled by adjusting the concentration of Ag, Cu, silicate, and the like contained in the solution, the number of rotations at the time of application in the spin coating method, the amount of the solution released in the spray method, or the pulling speed in the immersion method. it can. The first and second coating films thus formed are
By sintering simultaneously at 50 to 450 ° C. for 10 to 180 minutes, the conductive antireflection film according to the present invention can be obtained. In the present invention, in order to more effectively reduce the reflectance of the conductive antireflection film, for example, the reflectance of the first layer and the reflectance of the first layer may be reduced between the first layer and the second layer. By providing a third layer having a reflectance approximately in the middle of the reflectance of the two layers, two or more layers can be formed. At this time, the reflectance of the conductive anti-reflection film can be effectively reduced by setting the difference in the refractive index between two adjacent layers to be low. In the present invention, when the conductive anti-reflection film is composed of the first and second layers, the thickness of the first layer is usually 2.
00nm or less, set the refractive index to be about 1.7-3,
For the second layer, the thickness of the layer is set to be about 10 times or less the thickness of the first layer, and the refractive index is set to be about 1.38 to 1.70. When the third layer is provided between the first and third layers, the thickness and refractive index of each of the first to third layers are appropriately set in consideration of the light transmittance and the refractive index of the entire antireflection film. do it.

[0036]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail with reference to specific examples, but the present invention is not limited to the following examples.

First, ITO fine particles were dispersed in ethanol to prepare a 2% by weight ITO dispersion.

A 1% by weight silicate solution (tetramethoxysilane trimer / tetramer mixed solution (3.5%
Against mer)), 0 wt% with respect to SiO ₂ in SiO ₂ in terms of solid content (Comparative Example), 5,10,20,40,50 and 10
Fine particles of ITO were added and mixed so as to be 0% by weight (Examples 1 to 6) to prepare second to eighth dispersions (where the weight% is ITO (weight) / SiO ₂ (weight ) × 100). Next, the outer surface of the face panel (17-inch panel) of the cathode ray tube after the assembly is finished is puff-polished with cerium oxide to remove dirt, dust, oil and the like, and then the first dispersion is applied by spin coating. Thus, a first coating film was formed. The application conditions are as follows: panel (application surface) temperature is 30 ℃, rotation speed is 80rpm-5s at the time of solution injection
ec, 150 rpm-80 sec at the time of liquid sweeping (film formation). Next, on the first coating film, each of the second to eighth solutions is applied by a spin coating method under the conditions of 80 rpm-5 sec at the time of injecting the solution and 150 rpm-80 sec at the time of swirling the solution to form the second coating. After forming the film, the first and second coating films were baked at a temperature of 210 ° C. for 30 minutes.

FIG. 1 shows a cathode ray tube obtained in this way and corresponding to Examples 1 to 6.

In FIG. 1 (a), a color cathode ray tube has a panel 1 and a funnel 7 integrally joined to the panel 1.
The face panel 8 incorporated in the panel 1 has a three-color phosphor layer that emits blue, green, and red light, and fills a gap between the three-color phosphor layers. A fluorescent screen 9 composed of a black light absorbing layer is formed. The three-color phosphor layer is obtained by using a slurry in which each phosphor is dispersed together with PVA, a surfactant, pure water, and the like, and applying the slurry to the inner surface of the face panel 8 according to an ordinary method. The shape of the three-color phosphor layer may be a stripe shape or a dot shape. Further, a shadow mask 10 having a large number of electron beam passage holes formed inside and facing the fluorescent screen 9 is mounted. An electron gun 12 for irradiating the phosphor screen 8 with an electron beam is disposed inside the neck 11 of the funnel 7, and the electron beam emitted by the electron gun 12 collides with the phosphor screen 9, The three-color phosphor layer is excited and emits light. The conductive antireflection film 2 is formed on the outer surface of the face panel 8. Further, FIG.
2 shows a cross section of the cathode ray tube shown in FIG. As shown in FIG. 1 (b), on the surface of the face panel 8, a first layer (conductive layer) 14 containing the ITO fine particles 13, IT in the SiO ₂ matrix
The conductive anti-reflection film 2 is formed from the second layer 15 in which fine particles 13 of O are dispersed. Next, for the conductive anti-reflection films obtained in Examples 1 to 6 and Comparative Example 1, respectively, the surface resistance, resistance stability, film strength, and luminous regular reflectance were measured. The surface resistance was measured using Loresta IP MCP-T250 (manufactured by Yuka Denshi Co., Ltd.). The one in which the middle numerical value fluctuated was evaluated as x. Further, the film strength after contact with the conductive anti-reflection film a probe consisting of SUS 304 with a pressure of 1.5 kg / cm ^2, while the conductive reflecting該探needle was pressurized at a pressure of 1.5 kg / cm ² The sample was moved on the prevention film, and the sample which was not damaged by the probe was evaluated as ○, and the sample which was damaged was evaluated as ×. The luminous regular reflectance is
It is a value obtained by CR-353G (manufactured by Minolta). Table 1 shows the results of these measurements.

[0041]

[Table 1] As is clear from Table 1, the conductive anti-reflection films obtained in Examples 1 to 6 each have a low surface resistance effective for conducting from the surface of the conductive anti-reflection film, It has sufficient resistance stability. Also, the luminous regular reflectance is practically sufficient to function as a conductive anti-reflection film. On the other hand, in the conductive anti-reflection film obtained in the comparative example, the second layer is made of ITO.
Since no fine particles were present, the surface resistance was high and the resistance stability was unstable. As a result, conduction could not be obtained from the surface of the conductive antireflection film.

In Example 6, the film strength was x, but the film strength of the conductive antireflection film of Example 6 was
Practically enough.

As is clear from the above examples, according to the conductive anti-reflection film of the present invention, the first layer containing the first conductive fine particles is provided in the SiO ₂ matrix in the second layer.
By covering with a second layer containing conductive fine particles of
The refractive index of the second layer can be made smaller than the refractive index of the first layer, and the surface resistance of the second layer can be reduced. Therefore, the occurrence of AEF is prevented, the reflection of light is prevented by the second layer, and the conductive anti-reflection can be stably conducted from the second layer without forming a conduction portion or the like. A membrane can be provided. Further, since the number of steps and the cost for establishing conduction from the conductive anti-reflection film can be reduced, a conductive anti-reflection film having excellent productivity can be provided. Further, since the second layer covering the first layer has high stability, a conductive antireflection film having excellent durability can be provided.

According to the cathode ray tube of the present invention, the first conductive fine particles containing the first conductive fine particles are formed on the face plate.
And the first layer is covered with a second layer containing SiO ₂ and second conductive fine particles, so that the refractive index of the second layer is smaller than the refractive index of the first layer. In addition, the surface resistance of the second layer can be reduced. Therefore,
To provide a cathode ray tube capable of preventing generation of AEF, preventing reflection of light by a second layer, and stably conducting from the second layer without forming a conducting portion or the like. Can be. Further, since the number of steps and cost for establishing conduction from the conductive anti-reflection film can be reduced, a cathode ray tube excellent in productivity can be provided. Further, since the second layer covering the first layer has high stability, it is possible to provide a cathode ray tube capable of displaying a high-quality image for a long time.

[0045]

As is apparent from the above description, according to the conductive anti-reflection film of the present invention, the first layer containing the first conductive fine particles is made of SiO ₂ and the second conductive fine particles. By covering with a second layer containing a, the refractive index of the second layer can be made smaller than the refractive index of the first layer, and the surface resistance of the second layer can be lowered. Therefore,
A conductive antireflection film capable of preventing generation of AEF, preventing light reflection by the second layer, and stably conducting from the second layer without forming a conducting portion or the like. Can be provided. Further, since the number of steps and the cost for establishing conduction from the conductive anti-reflection film can be reduced, a conductive anti-reflection film having excellent productivity can be provided. Further, since the second layer covering the first layer has high stability, a conductive antireflection film having excellent durability can be provided.

According to the cathode ray tube of the present invention, the first conductive fine particles containing the first conductive fine particles are formed on the face plate.
And the first layer is covered with a second layer containing SiO ₂ and second conductive fine particles, so that the refractive index of the second layer is smaller than the refractive index of the first layer. In addition, the surface resistance of the second layer can be reduced. Therefore,
To provide a cathode ray tube capable of preventing generation of AEF, preventing reflection of light by a second layer, and stably conducting from the second layer without forming a conducting portion or the like. Can be. Further, since the number of steps and cost for establishing conduction from the conductive anti-reflection film can be reduced, a cathode ray tube excellent in productivity can be provided. Further, since the second layer covering the first layer has high stability, it is possible to provide a cathode ray tube capable of displaying a high-quality image for a long time.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a configuration of a cathode ray tube (a) and a conductive antireflection film (b) according to the present invention.

FIG. 2 is a diagram schematically showing a configuration of a conductive antireflection film in a conventional cathode ray tube.

FIG. 3 is a diagram schematically showing a configuration of a conductive anti-reflection film in a conventional cathode ray tube.

FIG. 4 is a diagram schematically showing a configuration of a conductive anti-reflection film in a conventional cathode ray tube.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Panel 2 ... Conductive anti-reflective film 3 ... Conductive layer 4 ... Anti-reflective layer 5 ... Conducting part 6 ... Solder 7 ... Funnel 8 ... Face panel 9 ...
Fluorescent surface 10 Shadow mask 11 Neck 12
... Electron gun 13 ... ITO fine particles 14 ... First layer 15
.... 2nd layer

Claims (6)

[Claims] 1. A semiconductor device comprising: a first layer containing conductive fine particles; and a second layer provided to cover the first layer and containing SiO ₂ and conductive fine particles. A conductive anti-reflection film. 2. The first and second conductive fine particles,
The conductive anti-reflective coating according to claim 1, wherein the conductive anti-reflective coating is the same or different substance selected from the group consisting of gold, silver, silver compound, copper, copper compound, tin compound and titanium compound. 3. The conductive anti-reflection film according to claim 1, wherein the particle size of the conductive fine particles (the value obtained by converting the particles into spheres having the same volume) is 400 nm or less. 4. The compounding amount of the conductive fine particles to be contained in the second layer is 5 to 5 with respect to the total amount of the conductive particles and SiO _2.
4. The conductive anti-reflection film according to claim 1, wherein the content is 50% by weight. 5. A face plate having a first surface provided with a fluorescent substance, and a first layer provided on a second surface opposite to the first surface of the face plate and containing conductive fine particles. And a second layer provided so as to cover the first layer and containing SiO ₂ and conductive fine particles. 6. The method according to claim 5, wherein the conductive fine particles are the same or different substances selected from the group consisting of gold, silver, silver compounds, copper, copper compounds, tin compounds and titanium compounds. A cathode ray tube as described.