JP2002156509A - Conductive antireflection film and glass panel for cathode-ray tube covered with the same formed thereon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive reflection preventing film which is provided with high contrast, excellent antistatic effect and electromagnetic wave shielding effect, is hardly accompanied by variation in optical characteristics and resistance before and after the time of heat treatment, exhibits low reflectance over the whole visible ray region, is provided with high film strength, curbs reflection on the rear surface when formed on a glass substrate with high transmittance so as to cover the substrate and further curbs generation of defects such as coloring unevenness and stains and to provide a glass panel for a cathode-ray tube covered with the film formed on the outer surface of the face part. SOLUTION: In a first layer and a second layer denominated successively from the substrate side, the first layer is characterized by being a layer formed by applying a solution containing >=20 pts.mass SiO2 particles with respect to 100 pts.mass Ru metal and/or particles of its compound to the substrate and by heating and baking it and the second layer is characterized by being a layer formed by applying a solution containing a silicon compound as a main component on the first layer and by heating and baking it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a conductive anti-reflection film,
This relates to a glass panel for a cathode ray tube having a coating formed on the outer surface of the face portion.

[0002]

2. Description of the Related Art A cathode ray tube is required to have properties such as reduction of reflected light and improvement of contrast, as well as antistatic and shielding of electromagnetic waves, and it is not necessary to provide an outer surface of a face portion of a glass panel which is a display surface of the cathode ray tube. By forming a metal film made of, for example, Ru for the purpose of shielding electromagnetic waves and an SiO ₂ film functioning as an anti-reflection film thereon, a film having conductivity and anti-reflection properties is formed. I have. Such a conductive anti-reflection film is formed by applying a coating solution containing metal particles of Ru on the outer surface of the panel glass, and then coating a coating solution containing silicate as a main component on the coating solution.
It is formed by heating at a temperature of 60 to 180 ° C. for 30 minutes.

[0003] In recent years, glass panels for cathode ray tubes having a flat outer surface of the face portion are becoming widespread. However, such flat glass panels have been used to obtain a desired mechanical strength. The radius of curvature is designed to be smaller than that of the outer surface, and the thickness of the peripheral region is increased compared to the center thickness of the face portion. Therefore, if such a flat glass panel is made of glass having a low light transmittance, the difference in the amount of transmitted light due to the difference in thickness between the central portion and the peripheral portion of the face portion becomes large, and the difference between the central portion and the peripheral portion becomes large. A luminance difference occurs in the video. Therefore, the glass panel is made of glass having a high light transmittance, thereby reducing the difference in transmittance between the central portion and the peripheral portion, and furthermore, the outer surface of the face portion is coated with a colored conductive antireflection film. Attempts have been made to improve the contrast. For forming such a conductive anti-reflection film, a CVD method, a sputtering method, a spray coating method,
A spin coating method or the like is used.

[0004]

A glass panel for a cathode ray tube having a conductive anti-reflection film formed thereon is frit-sealed with a funnel in a manufacturing process of the cathode ray tube, and further, the inside of the bulb is evacuated. In the process and the exhaust process, a heat treatment of 400 ° C. or more is performed. Conventional conductive anti-reflective coatings tend to fluctuate in reflectivity and resistance before and after this heat treatment, causing changes in appearance due to changes in the reflection color tone, and inducing a decrease in electromagnetic wave shielding properties.
There is a problem that desired reflectance and electromagnetic wave shielding performance cannot be stably obtained.

Further, as a coloring conductive antireflection film,
Using a material such as transition metal particles (for example, Ru) having a strong light absorbing property having a visible light absorption coefficient of 1.0 or more, a wavelength 550 when the thickness is converted to 10.16 mm, for example.
using a glass having a light transmittance of 70% or more in nm,
The transmittance is 5 to improve the contrast of the cathode ray tube.
When a film of about 0% is formed, a film having a geometric thickness of about 10 to 50 nm is formed.

However, it is difficult to form a completely uniform film by applying a liquid containing fine particles having high light absorbing properties to the glass surface by spin coating. In general, although a method of diluting the component concentration of a coating liquid and a technique of applying a small amount of liquid as accurately as possible have been proposed, tiny foreign substances (dust, dust) and organic substances remaining on glass have been proposed. There is a problem that aggregation or repelling of metal particles as a film component occurs due to the deposits or the like, resulting in defects such as uneven coloring and black spots.

In a colored conductive film composed of only the transition metal particles described above, the surface after the formation of such a film has a very high reflectance, and a SiO 2 film as an anti-reflection film is further formed thereon.
_When a two-layer conductive anti-reflection film is formed by forming _two films, the surface reflectance curve exhibits a V-shape with a large change depending on the wavelength, and is low over the entire range of visible light of 400 to 800 nm. It is difficult to obtain reflectivity.

Further, the above conductive anti-reflection film has a problem that the back surface reflectance is high because the film thickness is as small as 10 to 50 nm. When the back surface reflectance is high, the light of the phosphor on the inner surface of the glass panel for a cathode ray tube is reflected on the back surface of the conductive anti-reflection film and is reflected again on the inner surface of the glass panel. There is a drawback that an image by direct light and an image whose position is shifted by reflected light are simultaneously displayed, and the image appears double.

Therefore, the present invention provides a high contrast, excellent antistatic property and electromagnetic wave shielding property, but hardly fluctuates in optical properties and resistance values before and after heat treatment, and has a low reflectance over visible light in general. A conductive anti-reflection film, which has a high film strength and can suppress back surface reflection even when coated on a glass substrate having a high light transmittance, and can suppress occurrence of defects such as uneven coloring and spots. An object of the present invention is to provide a glass panel for a cathode ray tube having a coating formed on an outer surface of a face portion.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems and objects, and includes two layers formed on a substrate, and a first layer and a second layer in order from the substrate side. When referred to as a layer, the first layer is composed of ₂ parts of SiO ₂ particles per 100 parts by mass of fine particles of Ru metal and / or its compound.
The second layer is a layer formed by applying a solution containing 0 parts by mass or more and baking by heating, and the second layer is formed by applying a solution containing a silicon compound as a main component on the first layer and baking by heating. The conductive anti-reflection film is characterized by being a layer formed by performing the method described above.

Further, the film thickness of the first layer is 50 nm.
As described above, the transmittance is 90% or less, and the surface resistance is 10 ⁴ Ω / □.
It is characterized by the following.

[0012] Further, SiO 2 in a solution for forming the first layer may be used.
_{The two} particles are characterized in that crosslinks are formed in a network.

Further, according to the present invention, the conductive anti-reflection film is formed on the outer surface of the face portion so that the average radius of curvature of the outer surface of the face portion is 10,000 mm or more in all radial directions passing through the center of the face portion. When the thickness is converted to 10.16 mm, the light transmittance at a wavelength of 550 nm is 70.
% Of the glass, and the conductive antireflection film is referred to as a first layer and a second layer in order from the face side.
The first layer is a layer formed by applying a solution containing Ru metal and / or its compound particles and SiO ₂ particles having crosslinks formed in a network and heating and baking the second layer. Is a glass panel for a cathode ray tube, characterized in that it is a layer formed by applying a solution containing a silicon compound as a main component and baking by heating.

[0014]

The first layer is a layer formed by applying a solution containing not less than 20 parts by mass of SiO ₂ particles to 100 parts by mass of Ru metal and / or its compound particles and heating and firing the solution. The layer is a colored layer having a refractive index of 1.4 to 2.5 and a conductive coefficient of visible light absorption coefficient of 0.05 to 1.0 and having low light absorption. It has the effect of improving the surface light and reducing the surface reflected light and the back surface reflected light due to the interference with the second layer.

Note that the visible light absorption coefficient means the logarithmic ratio of the light intensity before and after transmission through an object. To explain using symbols, a is the radiant flux of the absorbed light absorbed by the object, i is the radiant flux of the incident light incident on the object, r is the radiant flux of the reflected light reflected on the object surface, and passes through the object. Assuming that the radiant flux of the transmitted light is t, the expression a = i−rt holds.
According to Lambert-Bouguer's law, the logarithm of the ratio of the radiant flux t of the transmitted light to the radiant flux i of the incident light is proportional to the transmission distance x of the light transmitted through the object.
/ I) =-kx holds. The proportional coefficient k at this time is called an absorption coefficient. When a thin film is formed on a substrate, reflection at the surface of the thin film and reflection at the interface between the substrate and the thin film occur, and the two reflected lights interfere with each other. Therefore, the absorption coefficient k also affects the reflectance of the thin film. I do. This absorption coefficient k is 0.05
When the thickness is less than the above, when the thickness x of the thin film is the same, the radiant flux t of the transmitted light is larger than the radiant flux i of the incident light, the coloring property is weak, and the contrast is poor. On the other hand, if it exceeds 1.0, the radiant flux t of the transmitted light is smaller than the radiant flux i of the incident light, the coloring property is too strong, the reflectivity of the back surface of the thin film becomes large, and the cathode ray made of glass having a high light transmittance. If a thin film is formed on a glass panel for a tube, the image projected on the cathode ray tube will appear double.

The geometric thickness is to be distinguished from an optical thickness such as λ / 4 and means a thickness independent of wavelength.

In the present invention, the film constituting the first layer is made of Ru metal and / or its compound particles and SiO ₂
It is a film formed by applying a solution containing particles and baking by heating, and when formed on a glass panel for a cathode ray tube to be subjected to a reheating treatment after the formation of a conductive antireflection film, the reheating treatment is also performed. It does not cause any change in film characteristics before and after, for example, transmittance, reflectance, and resistance value, and has high film strength.

In the present invention, the above-mentioned SiO ₂ particles are not amorphous (amorphous) particles, but are SiO ₂ particles in a crystallized state in advance.

In the present invention, the first layer is made of Ru metal or
And / or 100 parts by mass of the compound particles, S
iO_TwoApplying a solution containing 20 parts by mass or more of particles and baking by heating
SiO2_Twograin
The thickness of the first layer is increased by adding
Back reflection can be kept low. On the other hand, SiO _Two 
Particles are Ru metal and / or its compound particles
If too large, the resistance due to the increase in the distance between the Ru metal particles in the film is increased.
To reduce the value, more preferably, Ru metal and
And / or 100 parts by mass of the compound particles, SiO 2
_TwoThe particles are 30 to 150 parts by mass.

The first layer is formed by, for example, forming an aqueous sol containing Ru metal and / or compound particles thereof with SiO ₂
This can be achieved by preparing a coating solution obtained by ultrasonically mixing an aqueous sol containing particles in a polar solvent such as alcohol, applying the coating solution, and heating and baking.

The second layer formed by applying a solution containing a silicon compound as a main component and sintering the solution is 60
A transparent layer having a geometric thickness of about 150 nm and a refractive index of visible light of 1.4 to 1.6, and having an effect of reducing front surface reflected light and back surface reflected light by an interference effect with the first layer. are doing.

As the coating liquid used for forming the second layer,
SiO ₂ particles or (1) Formula (R ₁ ) _n M (OR ₂ ) _4-n (1) (where R _{1 is} an alkyl group, an alkenyl group, M: Si,
R _{2 is} an alkyl group, and n = 0 or 1) is more preferably used as a coating liquid because it has a practically high film strength. If necessary, Ti, Sn, Sb, Al, Zr,
A mixture of oxides or composite oxide particles containing a metal such as Ce or Zn, or a compound of the above formula (1) may be added.

In the present invention, it is more preferable that the film constituting the first layer has a thickness of 50 nm or more, a transmittance of 90% or less, and a surface resistance of 10 ⁴ Ω / □ or less. If the thickness is less than 50 nm, the effect of suppressing back surface reflection is not sufficient. On the other hand, if the film thickness is too large, the film itself may be cracked by stress caused by the decrease in the film thickness due to volatilization of the solvent inside the film in the heating and firing step after application of the solution. Is more preferable. On the other hand, if the transmittance is greater than 90%, the content of the conductive metal particles is reduced, so that 10 ⁴ Ω /
□ It is difficult to obtain the following surface resistance value, and desired electromagnetic wave shielding properties cannot be obtained.

Further, in the present invention, the SiO ₂ particles in the solution forming the first layer are cross-linked in a network to form voids of several to several tens nm in the matrix, and It is more preferable because Ru metal and / or its compound fine particles can be taken in and chemically adsorbed and stabilized. When such a solution is applied to the surface of a glass panel for a cathode ray tube and heated and fired to form a film, the film surface is suppressed in gloss peculiar to a metal, and has a low-reflection film over the entire visible light of 400 to 800 nm. Become. Therefore, a conductive antireflection film having a low reflectance over the entire visible light can be obtained by forming a film mainly composed of SiO ₂ as the second layer thereon and causing interference. . Further, SiO ₂ having cross-links formed in a network form
Aggregation of metal fine particles caused by extraneous foreign matter (dust, dust) or organic matter attached to glass at the time of film formation due to stabilization of Ru metal and / or its compound particles by particles. Repelling can be suppressed, and the occurrence of uneven coloring and black spots can be prevented. In the case where a film is formed by spin coating using glass as a substrate, the wettability with the glass surface is improved, so that spin-off due to minute irregularities on the glass surface (the glass is rotated by the glass rotation in the spin coating process). It is possible to suppress the occurrence of radial transmission unevenness due to the non-uniformity of the process of scattering excess liquid from the surface.

A known method can be used for preparing the network-crosslinked SiO ₂ particles contained in the solution for forming the first layer. For example, water / alcohol of alkoxide of Si can be used. The alkoxide of Si is hydrolyzed in the solution dissolved therein, and then the polycondensation reaction proceeds to form primary particles of SiO _{2. Then} , in the solution of the alkoxide of Si dissolved in water / alcohol, A method of obtaining crosslinked SiO ₂ particles by condensation polymerization, or the above-mentioned hydrolysis, and then the SiO ₂ primary particles obtained by condensation polymerization are chain-reacted under predetermined reaction conditions to form a three-dimensional chain. A method of obtaining network-formed SiO ₂ particles by forming them may be used.

In the glass panel for a cathode ray tube according to the present invention, the average radius of curvature of the outer surface of the face portion is 10,000 mm or more in all radial directions passing through the center of the face portion, and the wavelength at a wavelength of 550 nm when the thickness is converted to 10.16 mm. Since the light transmittance is made of glass having a transmittance of 70% or more, the difference in luminance between the central portion and the peripheral portion of the face portion is small, and the conductive antireflection film is coated on the outer surface of the face portion. Even when a colored conductive anti-reflection film having a high visible light absorption coefficient is formed as the first layer on such a high transmittance glass, it occurs due to the formation of the colored layer and is confirmed by transmitted light. It is possible to prevent the occurrence of defects such as coloring unevenness and spots, and to obtain a cathode ray tube with good visibility of a displayed image.

In the glass panel for a cathode ray tube of the present invention, the formation of the two-layer conductive anti-reflection film coated on the outer surface of the face portion is performed by sequentially applying a solution, drying and heating and baking for each layer. Alternatively, after applying and drying the solution for the first layer, applying and drying the solution for forming the second layer, these two layers may be simultaneously heated and fired. The heating and firing temperature is 300 ° C. or higher from the viewpoint of removing the solvent in the coating solution and stabilizing the film, and is preferably from 300 to 5 from the viewpoint of forming the glass panel for a cathode ray tube.
20 ° C.

Further, in the glass panel for a cathode ray tube of the present invention, in addition to the above-mentioned first and second layers, an additional film may be added for the purpose of improving the adhesion of the film and adjusting the color tone as required. It is also possible to provide a suitable film layer as appropriate.

As a method for forming the conductive antireflection film of the present invention, a general film forming means can be used. For example, a spin coating method, a sputtering method, a vacuum deposition method, or the like can be applied, but the spin coating method is most suitable because a film having a large film thickness can be produced relatively inexpensively.

The conductive anti-reflection film of the present invention can be formed by a spin coating method, and since the desired characteristics can be obtained even though the total number of the films is two, it can be manufactured at low cost. Also, the present invention can be applied to various displays such as a liquid crystal display substrate and a plasma display substrate which are subjected to a high-temperature heat treatment after film formation.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments.

Table 1 shows the material of each layer constituting the conductive anti-reflection film of the example and the comparative example, and the geometric thickness.

[0033]

[Table 1]

The method for producing the conductive antireflection films of Examples 1 to 3 and Comparative Example in Table 1 is as follows.

First, the minimum value of the average radius of curvature of the outer surface of the face portion (in all radiation directions passing through the center of the face portion) is 50,000 mm, and the light transmittance at a wavelength of 550 nm when the thickness is converted to 10.16 mm is 80. Glass panel for cathode ray tube (21 inch size)
Was prepared.

Next, regarding the first layer and the second layer,
A solution containing a predetermined amount of the membrane material was prepared.

Example 1 As a coating solution used for the first layer, Ru / metal particles (average primary particle size: 2 nm) were added to a water / ethanol sol containing SiO ₂ particles having a primary particle size of 20 nm.
Aqueous sol containing Ru: SiO ₂ = 100: 6
A solution was prepared by dispersing and mixing under vibration in ultrasonic waves so as to be 0. As a coating liquid used for the second layer, SiO ₂
A solution was prepared by dispersing particles (average primary particle size: 3 nm) in a water / ethanol solvent.

(Example 2) As a coating solution used for the first layer, SiO _{2 in} which Ru metal particles (average primary particle size: 2 nm) and a cross-link were formed in a network shape was used, and the mass ratio was Ru: SiO ₂ =
A solution was prepared by dispersing and mixing in a water / ethanol solvent under ultrasonic vibration in a ratio of 100: 60.

As for the SiO ₂ sol, silica ethoxide is hydrolyzed in a solution of silica ethoxide in a water / ethanol solvent, and then polycondensation is allowed to proceed to form primary particles (average of SiO ₂ ). Primary particle size 10n
After forming m), the obtained primary particles of SiO ₂ were reacted in a chain to obtain a sol containing networked SiO ₂ particles. An aqueous sol containing Ru metal particles (average primary particle size: 2 nm) was dispersed and mixed under vibration in ultrasonic waves so as to have the above-mentioned mass ratio, to obtain a liquid containing Ru metal particles and network SiO ₂ . Further, the coating solution used for the second layer was the same solution as in Example 1.

(Embodiment 3) The same network SiO as in Embodiment 2
_{2 Using a} sol, R is used as a coating liquid for the first layer.
The mass ratio of the aqueous sol containing u metal particles (average primary particle size 2 nm) to the network SiO ₂ sol is Ru: SiO ₂ = 100: 30.
A solution was prepared by dispersing and mixing in a water / ethanol solvent under ultrasonic vibrations so that Further, the coating solution used for the second layer was the same solution as in Example 1.

(Comparative Example) As a coating solution used for the first layer, a solution in which Ru metal particles (average primary particle size: 2 nm) were dispersed in a water / ethanol solvent was prepared. Further, the coating solution used for the second layer was the same solution as in Example 1.

Using the solutions for conductive anti-reflective coatings of Examples 1 to 3 and Comparative Example, each layer was formed on the above-mentioned glass panel for a cathode ray tube by spin coating.

The cathode ray tube panel (21 inch size) was prepared, and its outer surface was polished with cerium oxide, washed and dried. Next, after the surface of the glass panel is heated to about 40 ° C. by a pre-heat treatment, the glass panel is set in a spin coater, and rotated at a rotation speed of 40 to 150 rpm, from the first liquid nozzle installed above the glass panel. The solution for forming the first layer was dropped. At this time, the first nozzle was moved from the vicinity of the center of the glass panel toward the periphery at a speed of 50 to 500 mm / min. Thus, the solution for forming the first layer was uniformly applied to the outer surface of the face portion of the glass panel and dried. After that, the glass panel is continuously rotated at 40 to 40 rpm.
While rotating at 150 rpm, a solution containing SiO ₂ was dropped from the second liquid nozzle installed above the glass panel onto the outer surface of the face portion in the same manner as described above, uniformly applied, and dried.

After the two-layer film is formed on the glass panel in this manner, the glass panel is taken out from the spin coater, placed in an electric furnace, and baked at 400 ° C. for 30 minutes. A conductive antireflection film having a two-layer structure was obtained.

In the conductive anti-reflection films of Examples 1 to 3 and the comparative example, the conductive anti-reflection film was set such that the total transmittance (the product of the transmittance of the film and the glass) at a wavelength of 550 nm was almost 50%. A film was formed.

The thus obtained conductive anti-reflection films according to Examples 1 to 3 and Comparative Example were formed on the outer surface thereof at a central portion of a glass panel for a cathode ray tube, and a wavelength of 400
The surface luminous reflectance and reflection chromaticity using a D65 light source at 、 ２800 nm and a 2 ° visual field, the back surface reflectance at a wavelength of 550 nm, and the resistance value were measured.

The measurement results are shown in Table 2, and the reflectance curves are shown as A to D in FIG. In FIG. 1, A represents the reflectance curve of Example 1, B represents Example 2, C represents Example 3, and D represents the reflectance curve of Comparative Example.

The surface reflectance in Table 2 is measured by an instantaneous multi-reflectometer (MCPD-1000 manufactured by Otsuka Electronics Co., Ltd.).
And 15 ° regular reflection was measured using The backside reflectance was measured by measuring the total reflectance from the backside of the glass panel on which the conductive antireflection film was formed using a spectrophotometer (a self-recording spectrophotometer U-4000 manufactured by Hitachi, Ltd.). It is obtained in consideration of the reflectance and the absorptance. The resistance value is obtained by forming an electrode with ultrasonic solder at the center of both short sides of the face portion of the glass panel, and measuring the resistance between the electrodes using an insulation resistance meter (manufactured by Toa Denpa Co., Ltd.).

Table 2 shows that the conductive anti-reflection coatings of Examples 1 to 3 and Comparative Example were each made up of 10 glass panels for a cathode ray tube.
After performing film formation and heat treatment on the sheets (n = 10), the number of occurrences of unevenness of the colored film by a transmitted light inspection and the total number of black defects visually observed in 10 sheets were investigated. The result is shown.

Further, Table 2 shows the scratch resistance and pencil hardness of the glass panel for a cathode ray tube having the conductive anti-reflection film formed on the outer surface according to Examples 1 to 3 and Comparative Example as evaluation of the film strength. The results are shown.

The abrasion resistance was measured using a surface property measuring device (HEIDON-14DR, manufactured by Shinto Kagaku Co., Ltd.) under a load of 1 kg under an eraser (ER-2 manufactured by Lion Office Equipment Co., Ltd.).
After the film surface reciprocated 100 times at (0R), the presence or absence of damage on the surface was visually determined. The evaluation criteria are expressed as follows: ○: no scratch is visually observed, Δ: some scratch is visually observed, ×: peeling is visually observed. The pencil hardness was measured using the above-mentioned surface property measuring instrument, and a pencil of various hardness was scanned once under a load of 1 kg on the membrane surface, and the pencil hardness at which scratches began to be formed on the membrane surface by visual inspection was determined. It is shown as

[0052]

[Table 2]

Next, the glass panels for cathode ray tubes on which the conductive anti-reflection films of Examples 1 to 3 and Comparative Example were formed were reheated at 450 ° C. for 60 minutes, and their wavelengths were adjusted to 400. D65 light source at ~ 800 nm, 2 °
Surface luminous reflectance and reflection chromaticity using visual field, wavelength 55
The back surface reflectance at 0 nm and the resistance value were measured.
Table 3 shows the results.

In FIG. 1, A ′ to D ′ are:
A is a reflectance curve after each reheating treatment in each of the reflectance curves after the reheating treatment, where A 'is Example 1, B' is Example 2, C 'is Example 3, and D' is a comparison curve after each reheating treatment. Is shown.

[0055]

[Table 3]

The conductive antireflection films of Examples 1 to 3 according to the present invention and the glass panel for a cathode ray tube on which the coatings are formed have lower surface reflectance and lower surface reflectance than the comparative example. Substantially no change in optical characteristics or resistance value due to heat treatment during the manufacture of a cathode ray tube, and also occurs during the formation of a conductive anti-reflection film, such as coloring unevenness and black spots confirmed by transmitted light. The occurrence of defects could be greatly reduced. In addition, the glass panels for cathode ray tubes coated with the conductive anti-reflection films of Examples 1 to 3 all showed higher scratch resistance and pencil hardness than the comparative examples.

In particular, the conductive anti-reflection coatings of Examples 2 and 3 and the glass panel for a cathode ray tube coated with the coatings are
It exhibited lower surface reflections over the entire visible light range of 400-800 nm and had better performance.

[0058]

As described above, the conductive anti-reflection film of the present invention and the glass panel for a cathode ray tube on which the coating is formed are as follows.
While having high contrast, excellent antistatic properties and electromagnetic wave shielding properties, optical properties and resistance values are not easily changed before and after heat treatment, have low reflectance over visible light, and have high film strength. The glass panel for a cathode ray tube according to the present invention has an excellent effect, and the average radius of curvature of the outer surface of the face portion is 100 in all radial directions passing through the center of the face portion.
Although it is not less than 00 mm, the light transmittance at a wavelength of 550 nm when converted to a thickness of 10.16 mm is made of glass having a value of 70% or more. Therefore, the difference in luminance between the central portion and the peripheral portion of the face portion is small. Even if a colored conductive anti-reflection film having a high visible light absorption coefficient is formed on such a high transmittance glass, the colored layer is That can prevent the occurrence of defects such as coloring unevenness and spots which are caused by the transmitted light and which can be obtained at the time of formation of the CRT, and which has an excellent effect that a cathode ray tube with good display image visibility can be obtained. It is.

[Brief description of the drawings]

FIG. 1 is a graph showing a reflectance curve.

[Explanation of symbols]

 A: reflectance curve of Example 1 A ′ reflectance curve after reheating treatment of Example 1 B: reflectance curve of Example 2 B ′ reflectance curve after reheating treatment of Example 2 C: reflection of Example 3 Rate curve C ′ Reflectance curve after reheating treatment of Example 3 D Reflectance curve of comparative example D ′ Reflectance curve after reheating treatment of Comparative example

Continued on the front page F term (reference) 2K009 AA05 BB02 CC09 CC14 DD02 DD06 EE03 5C032 AA02 DD02 DE01 DF07 DG01 DG02 DG10

Claims (4)

[Claims] 1. A method comprising: two layers formed on a substrate; a first layer and a second layer, which are referred to as a first layer and a second layer in this order from the substrate side.
Layer is made of Ru metal and / or its compound particles 100
A layer formed by applying a solution containing 20 parts by mass or more of SiO ₂ particles with respect to parts by mass and heating and baking the second layer. The second layer has a silicon compound as a main component on the first layer. A conductive antireflection film, which is a layer formed by applying a solution to be coated and baking by heating. 2. The conductive layer according to claim 1, wherein the first layer has a thickness of 50 nm or more, a transmittance of 90% or less, and a surface resistance of 10 ⁴ Ω / □ or less. Anti-reflection film. 3. The conductive anti-reflection film according to claim ₂ , wherein the SiO ₂ particles in the solution forming the first layer are crosslinked in a network. 4. A conductive anti-reflection film is formed on the outer surface of the face portion so that the outer surface of the face portion has an average radius of curvature of 10,000 m in all radial directions passing through the center of the face portion.
m and a glass having a light transmittance of 70% or more at a wavelength of 550 nm when the thickness is converted to 10.16 mm. The conductive anti-reflection film comprises a first layer and a second layer in order from the face side. When referred to as a layer of
u is a layer formed by applying a solution containing SiO ₂ particles having cross-links formed in a network and metal particles and / or compound particles thereof, followed by heating and sintering. The second layer mainly contains a silicon compound. A glass panel for a cathode ray tube, which is a layer formed by applying a solution as a component and baking by heating.