JP2001143642A - Cathode ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cathode ray tube(CRT) with an antireflective layer, which has a low surface resistance effective to prevent AEF with a high strength. SOLUTION: The outside of the face panel 5 of a CRT is provided with an antireflective layer 16 consisting of a lower conductive layer 14 composed of conductive fine particles 17 and an upper layer composed of SiO2 as the main ingredient. The conductive layer 14 contains at least two kinds of conductive fine particles 17a and 17b, whose average particle sizes are designated M1, M2, etc., with a larger one followed by a smaller one, having the following relationship: 1.25<=M1/M2<=10. Further, an upper layer 15 consisting of mainly SiO2 is installed on the conductive layer 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode ray tube having an antireflection surface treatment film (antireflection film) having a high effect of preventing electromagnetic wave leakage on an outer surface of a front panel (face panel) of a faceplate.

[0002]

2. Description of the Related Art Generally, in a color cathode ray tube used for a TV cathode ray tube, a computer display, or the like, phosphor layers of blue (B), green (G), and red (R) are formed on the inner surface of a face panel by dots. The phosphors are arranged in a predetermined pattern such as a shape or a stripe, and these phosphors emit light of each color by the collision of an electron beam to display an image.

Since such a cathode ray tube is usually used in external light, a plurality of layers having different refractive indexes are laminated on the outer surface of the face panel (the lower layer on the side close to the face panel has a lower refractive index). A high layer, and an upper layer farther from the face panel is a layer having a lower refractive index.) An antireflection film is provided. The light reflected at the interface of each layer of the antireflection film is configured to interfere with each other and cancel each other.

Many proposals have been made to further improve various characteristics of a cathode ray tube having such an anti-reflection film.

That is, an electromagnetic wave (electric field) generated from the electron gun and the vicinity of the deflection yoke inside the cathode ray tube leaks and may adversely affect peripheral electronic devices and the human body. electric f
It is conceivable to reduce the surface resistance of the anti-reflection film formed on the outer surface of the face panel in order to prevent the occurrence of the anti-reflection (or the anti-reflection) of the face panel. Various surface treatment films have been developed as films.

For example, JP-A-61-118932,
No. 61-118946, JP-A-63-160140, etc.
Various surface treatment methods for preventing charging of the face panel have been disclosed. Further, the anti-reflection film for the purpose of preventing AEF needs to have a surface resistance value (sheet resistance measured according to JIS K-6911) of 1 × 10 ⁶ Ω / sq or less. And a conductive layer containing conductive fine particles of a metal oxide such as indium-tin.

Further, in order to improve the contrast, a dye (coloring material) having a selective absorption in a visible wavelength range is also included in the surface treatment film.

[0008]

However, in a cathode ray tube having a surface-treated film containing a coloring material, the surface resistance of the surface-treated film increases, so that AEF cannot be sufficiently prevented. there were.

An antireflection film having a conductive layer containing colored conductive fine particles such as silver has also been proposed. However, the conductive fine particles are not necessarily required to have a desired visible wavelength range (550 nm).
(Neighboring) is not selectively absorbed, so that improvement in contrast cannot be expected, and lack of weather resistance such as UV resistance, moisture resistance, and chemical resistance, resulting in deterioration of film strength or increase in resistance. There was a problem of doing.

Further, in order to improve the long-term reliability and the film strength of the antireflection film, it is conceivable to include a binder such as SiO _{2 in} the conductive layer. However, the desired surface resistance value could not be obtained because the resistance value greatly increased.

The present invention has been made to solve these problems, and provides a cathode ray tube having an antireflection film having a low surface resistance effective for preventing AEF and having sufficient film strength. The purpose is to do.

[0012]

According to a first aspect of the present invention, there is provided a cathode ray tube having a structure in which a translucent panel and two or more layers disposed on an outer surface of the panel are laminated. A cathode ray tube comprising a film and a phosphor layer disposed on an inner surface of the panel, wherein the antireflection film has at least one conductive layer, and the conductive layer has at least two different types of conductive layers. M ₁ , M ₂ containing conductive fine particles and increasing the average particle size of these conductive fine particles in descending order.
Where 1.25 ≦ M ₁ / M ₂ ≦ 10.

According to a second aspect of the present invention, there is provided a cathode ray tube, comprising: a translucent panel; an antireflection film having a structure in which two or more layers provided on an outer surface of the panel are laminated; and an inner surface of the panel. A cathode ray tube provided with a phosphor layer provided, wherein the antireflection film has at least one conductive layer, and the conductive layer is of the same type and has two or more peaks in the particle size distribution. When conductive particles are contained and the peaks of the particle diameters of the conductive particles are P ₁ , P _2, ... In descending order, 1.25 ≦ P ₁ / P ₂ ≦ 10.

In the present invention, the conductive fine particles include:
Fine particles of metal such as silver (Ag), palladium (Pd), and gold (Au), silver oxide, silver nitrate, silver acetate, silver benzoate, silver bromate, silver bromide, silver carbonate, silver chloride, and chromic acid Silver,
Fine particles of a silver compound such as silver citrate, and ITO,
Fine particles of tin oxide such as ATO (antimony-tin oxide) can be mentioned, and one or more of them can be selected and used.

The average particle diameter of the two or more different conductive fine particles used in the present invention is M ₁ , M ₂
When the ..., the value of M _1,. 1 to and preferably a 10~100nm than 400 nm, the value of M _2, preferably from 0.1 to 320 nm is preferably set to 1 to 80 nm. Also, if you select the one type of the conductive fine particles having two or more peaks in the particle size distribution, the peak of particle diameter, when the P _1, P ₂ ...... in descending order, the P ₁ Value from 1 to 400
More preferably nm is set to 10 to 100 nm, the value of P _2, 0.1 to
More preferably, it is set to 1 to 80 nm.
In any case, the use of particles with a particle size exceeding 400 nm
Not only does this significantly decrease the light transmittance of the film, but also causes scattering of light due to particles, which is not preferable because the film becomes cloudy and the resolution decreases.

The ratio of the content of these conductive fine particles is such that the content (molar number) of the first conductive fine particles having the largest average particle size or the maximum particle size of the particle size distribution peak is C ₁ , 2. The content (molar number) of the second largest second conductive fine particle is C
_When it is set to ₂ , 0.01 ≦ C ₁ / C ₂ ≦ 100, more preferably 0.05 ≦ C ₁ / C ₂ ≦ 10. When the content ratio (molar ratio) is less than 0.01, the resistance value and the film strength do not change from the case where the conductive layer is composed of only the second conductive fine particles. Conversely, when the content ratio exceeds 100, the resistance and the film strength are not different from those in the case where the conductive layer is composed of only the first conductive fine particles, which is not preferable.

In the cathode ray tube of the present invention, silica (SiO ₂ ) is a main component directly or via another layer on the conductive layer (high refractive index layer) composed of such conductive fine particles. An upper layer having a low refractive index is provided, and the antireflection film has a structure in which two or more such layers are stacked. The thickness ratio of the lower conductive layer to the upper layer mainly composed of SiO ₂ is not particularly limited, but may be 1: 1 to 1: 1.
It is desirable to set the ratio to 1: 5.

In the present invention, in order to form such an antireflection film, it is desirable to adopt a wet method (wet method) described below. In this method, first, the ratio of the average particle size (M ₁ / M ₂ ) or the ratio of the particle size at the peak of the particle size distribution (P
₁ / P ₂ ) is one or two in the range of 1.25 to 10.
More than one kind of conductive fine particles are added to a solvent containing ethanol, 2-propanol or the like as a main component, and sufficiently stirred to prepare a dispersion. Then, the obtained dispersion liquid was polished and washed with cerium oxide on the outer surface of the face panel,
Spin coating, directly or through another layer (underlayer),
It is applied by a known method such as spray coating, roll coating, bar coating, etc. to form a lower coating film.

Next, on the lower coating film, ethanol or
A dispersion containing silica alkoxide (alcoholate) as a main component using 2-propanol or the like as a solvent is applied by a known method such as spin coating, spray coating, roll coating, bar coating, etc. to form an upper layer coating film. . Here, when spin coating is used to form the upper coating film, a smoother film is formed, and high resolution is obtained.

Thereafter, the lower and upper coating films are simultaneously dried and cured or fired by heating the coating film in which the upper and lower coating films are laminated. In this method, in the process of densifying the silica gel of the upper layer by baking, the density of the lower conductive fine particle layer is also increased, so that the conductive fine particles come into contact with each other and sufficient conductivity is obtained. Thus, an antireflection film in which the conductive layer containing one or more kinds of conductive fine particles having different particle diameters and the upper layer mainly composed of SiO ₂ are formed.

Further, in the present invention, for example, since the conductive layer contains two or more kinds of conductive fine particles having an average particle diameter ratio in the above range, the film strength of the antireflection film is greatly improved. That is, in the layer made of conductive fine particles, as shown in FIG. 1 (a), since a large void portion 2 exists between the conductive fine particles 1, sufficient film strength cannot be obtained. As shown in FIG. 1 (b), since two or more types of conductive fine particles 1 having different particle sizes are contained, the gap between the first conductive fine particles 1a having a large particle size has a smaller particle size. When the second conductive fine particles 1b enter,
Since the gaps 2 existing between the first conductive fine particles 1 are filled, the mechanical strength as an antireflection film is greatly improved.

Here, the first conductive fine particles having a large particle size
The average particle size of 1a is M₁, A second conductive material having a smaller particle size
The average particle diameter of the fine particles 1b is M_TwoAnd the ratio of the average particle size
(M ₁/ M_Two) Is less than 1.25, the second conductive fine
The voids 2 between the first conductive fine particles 1a are formed by the particles 1b.
Insufficient filling and sufficient improvement in film strength
Not. On the contrary, M₁/ M_TwoIf the value of is greater than 10,
Average particle size M of second conductive fine particles 1b_TwoWas too small
In order to fill the gap 2 existing between the first conductive fine particles 1,
Effect is not sufficiently exhibited, and has sufficient film strength
Can not. In the drawings, reference numeral 3 denotes a face panel,
No. 4 is SiO_TwoThe upper layer mainly composed of
You.

Further, in the present invention, since a smooth upper layer mainly composed of SiO ₂ is provided on such a conductive layer composed of two or more kinds of conductive fine particles, high resolution is obtained. In the upper layer, an alkylsilane derivative such as an alkylsilane or a fluoroalkylsilane, a silica coupling agent, silicone or the like is contained in an amount of 0.01 to 20% (in terms of mass%; the same applies hereinafter), more preferably 1 to 5%. , It is possible to further improve the film strength and the weather resistance.

Further, in the present invention, since the voids between the conductive fine particles are filled with other conductive fine particles having different particle diameters, the surface resistance is lower than that of a conventional surface treatment film using an insulating material as a binder. A rise in the value is suppressed, and AEF can be effectively prevented. Furthermore, since different types of conductive fine particles are contained in the conductive layer, migration of particles and the like hardly occur, and long-term reliability is obtained.

[0025]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a sectional view showing the structure of a color cathode ray tube according to one embodiment of the present invention.

As shown in the drawing, the cathode ray tube of the embodiment is a translucent panel (face panel) such as a glass panel.
5 and an envelope composed of a funnel 6 and a neck 7 integrally joined to the panel 5, and a phosphor screen 8 is provided on the inner surface of the panel 5. The phosphor screen 8 is a phosphor layer of each color of blue (B), green (G), and red (R) arranged and formed in a predetermined shape such as a stripe shape and a circular dot shape (not shown). And a light absorbing layer (black matrix) (not shown) that fills the gaps between these phosphor layers. In addition,
The phosphor layers of blue, green, and red are a blue light-emitting phosphor (ZnS: Αg, Al) and a green phosphor (ZnS:
Cu, Δl), a red phosphor (Y ₂ O ₂ S: Eu)
Are mixed and dispersed in pure water together with polyvinyl alcohol (PVA), ammonium bichromate (ADC), a surfactant, etc. (suspension).
Is applied and dried on the inner surface of the panel by a usual method.

Further, a shadow mask 9 having a large number of electron beam passage holes formed therein is disposed opposite to and inside the phosphor screen 8, and an electron beam is provided in the neck 7 of the envelope. An electron gun 11 emitting 10 is provided. Further, inside the funnel 6, an electron gun 1 is provided.
An inner shield 12 that shields the electron beam 10 emitted from 1 from an external magnetic field is disposed, and a deflecting device 13 that deflects the electron beam 10 by the generated magnetic field is disposed outside.

[0029] the outer surface of the panel 5 in such a cathode ray tube, as shown enlarged in FIG. 3, the conductive layer 14 and the SiO ₂
An anti-reflection film 16 having a structure in which an upper layer 15 mainly composed of is laminated. The conductive layer 14 contains two different types of conductive fine particles 17 having the following average particle diameter ratios. That is, the average particle size of the conductive fine particles 17 is set to M ₁ , M ₂
..., the ratio (M ₁ / M ₂ ) of the average particle diameter of the first conductive fine particles 17a having the largest particle diameter to the average particle diameter of the second conductive fine particles 17b having the second largest particle diameter is as follows. From 1.25
Two or more types of conductive fine particles 17 are set to fall within the range of 10.
Is selected, and a conductive layer is formed mainly of the conductive fine particles 17.

In the cathode ray tube of the embodiment constructed as described above, the anti-reflection film 16 stably realizes a low surface resistance value effective for preventing the generation of AEF, and the conductive layer 14 Since two or more types of conductive fine particles 17a and 17b having significantly different average particle diameters are contained and the gap 18 is almost eliminated between the conductive fine particles 17a and 17b, the film strength of the antireflection film 16 is greatly improved. are doing.

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

Examples 1 to 8 A lower layer coating solution and an upper layer coating solution for forming an antireflection film were respectively prepared. First, as a lower layer coating solution,
ITO (average particle size 100 nm), Au (average particle size 50-85n)
m), Ag-Pd (average particle size 55 to 95 nm) fine particles,
Ethanol dispersions containing the lower layer in a molar ratio shown in Table 1 and containing other components such as a dispersant and water were prepared.

Further, a dispersion liquid containing 1.0% of an alcoholate of silica was prepared as a coating liquid for the upper layer.

Next, the outer surface of the cathode ray tube face panel (17-inch panel) after assembly is buffed with cerium oxide to remove dirt, dust, oil, etc. Apply by spin coating method, about 0.
An undercoating film having a thickness of 05 to 0.2 μm was formed. The application conditions are as follows: panel (application surface) temperature is 30 to 45 ° C, rotation speed is 80rpm-5sec when liquid is injected, and 150rpm-80sec when liquid is shaken (film formation).
And

Next, an upper layer coating solution was applied onto the lower layer coating film at a rate of 80 rpm-5 sec when the liquid was poured, and 150 rpm-80 s when the liquid was shaken off.
Apply by spin coating under ec conditions, about 0.05-0.2
After forming a film having a thickness of μm, the upper and lower coating films were baked at a temperature of 210 ° C. for 30 minutes to form a smooth surface treatment film (anti-reflection film).

As comparative examples, ITO, Au, Ag-
Each fine particle of Pd was selected in a combination shown in Table 2 to prepare a lower layer coating solution. Using this lower layer coating solution, a smooth antireflection film was formed in the same manner as in the example.

Next, Examples 1 to 8 and Comparative Examples 1 to 8
The inter-panel resistance of each surface-treated film obtained in the above was measured. Measurements were taken at H, which is the midpoint of both short sides of the panel.
Immediately above the so-called register mark portion at the end, terminals were each made of special solder (Cerasolaza manufactured by Asahi Glass Co., Ltd.), and the resistance value between these terminals was measured by a tester.

The scratch and eraser strengths (ablation strengths) were measured. In measuring the eraser strength, apply a pressure of 9.8 × 10 ⁴ Pa to the eraser.
When the film was reciprocated 100 times, a mark on the surface of the film which did not show any visible mark was judged as 、, and a mark which was not recognized by ordinary light but could be recognized by strong light was evaluated as ×. Further, the scratch strength was determined by applying a load of about 19.6 N in the vertical direction using a Rockwell hardness HRC 60 test needle, and checking for scratches. Table 1 shows the measurement results.
And in the lower column of Table 2.

[0039]

[Table 1]

[0040]

[Table 2]

As is clear from Table 1, all of the antireflection films obtained in Examples 1 to 8 have a low resistance value effective for preventing AEF and have sufficient film strength.
On the other hand, the antireflection films obtained in Comparative Examples 1 to 8 are:
As is clear from Table 2, the ratio of the average particle size of the two types of conductive fine particles constituting the conductive layer is smaller than 1.25 or larger than 10, or the content of the two types of conductive fine particles. Since the ratio (molar ratio) is not in the range of 0.01 to 100, the film strength is not sufficient, and it is difficult to put to practical use. In addition, the antireflection films obtained in Comparative Examples 1 to 2, 4 to 5 and 7 have significantly higher resistance values than those of Examples, and do not have sufficient conductivity effective for preventing AEF.

[0042]

As is apparent from the above description, according to the present invention, a low-resistance antireflection film which has sufficient film strength, is stable against changes in environmental conditions and the like, and is effective for preventing AEF. And a high-performance cathode ray tube can be realized.

[Brief description of the drawings]

FIG. 1 schematically shows the structure of an antireflection film,
(A) is an enlarged sectional view showing a structure of an antireflection film in a conventional cathode ray tube, and (b) is an enlarged sectional view showing a structure of an antireflection film in a cathode ray tube of the present invention.

FIG. 2 is a sectional view showing a schematic configuration of a color cathode ray tube according to one embodiment of the present invention.

FIG. 3 is an enlarged sectional view showing a structure of an antireflection film in the cathode ray tube of the embodiment.

[Explanation of symbols]

5 Panel 8 Phosphor screen 9 Shadow mask 14 Conductive layer 15 Upper layer mainly composed of SiO ₂ 16 Antireflection film 17 Conductive fine particles 17a... First conductive fine particles 17b... Second conductive fine particles

Claims (8)

[Claims] 1. A light-transmitting panel, an antireflection film having a structure in which two or more layers provided on an outer surface of the panel are laminated, and a phosphor layer provided on an inner surface of the panel. Wherein the antireflection film has at least one conductive layer, the conductive layer contains at least two types of conductive fine particles, and the average particle size of these conductive fine particles is A cathode ray tube characterized by satisfying 1.25 ≦ M ₁ / M ₂ ≦ 10, where M ₁ , M _2, ... 2. The value of M ₁ is 1 to 400 nm, preferably 10 to 100 nm, and the value of M ₂ is 0.1 to 320 nm.
2. The cathode ray tube according to claim 1, wherein the thickness is more preferably 1 to 80 nm. 3. A light-transmitting panel, an antireflection film having a structure in which two or more layers provided on an outer surface of the panel are stacked, and a phosphor layer provided on an inner surface of the panel. Wherein the antireflection film has at least one conductive layer, and the conductive layer contains conductive fine particles of the same type and having two or more peaks in the particle size distribution, and P ₁ , P ₂
A cathode ray tube, wherein 1.25 ≦ P ₁ / P ₂ ≦ 10. The value of wherein said P ₁ is more preferably. 1 to 400 nm is 10 to 100 nm, the value of the P ₂ is 0.1 to 320 nm
4. The cathode ray tube according to claim 3, wherein the thickness is more preferably 1 to 80 nm. 5. The content (molar number) of the first conductive fine particles having the largest average particle diameter or the maximum particle diameter of the particle size distribution is C ₁ , and the second largest second conductive fine particles are described. 5. The cathode ray tube according to claim 1, wherein the content (molar number) of C ₂ satisfies 0.01 ≦ C ₁ / C ₂ ≦ 100. 6. The method according to claim 5, wherein the content ratio C ₁ / C _{2 of the first} conductive fine particles and the second conductive fine particles is 0.05 ≦ C ₁ / C ₂ ≦ 10. A cathode ray tube as described. 7. The cathode ray tube according to claim 1, wherein an upper layer mainly composed of SiO ₂ is provided on the conductive layer. 8. The cathode ray tube according to claim 7, wherein a thickness ratio of the conductive layer to the upper layer mainly composed of SiO ₂ is from 1: 1 to 1: 5.