JP2002053803A - Coating, method for producing coating film, coating film, method for producing electron tube and electron tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating dryable rapidly after coating, good in wet spreading and causing no drying unevenness on the coating film after dried, and to provide an electron tube producible in a shorter time than conventional ones and excellent in a displaying quality by forming a coating film for the surface coat of the electron tube using the above coating. SOLUTION: This method for producing a coating film comprises mixing, at a specified ration, at least two selected from the group consisting of methanol, ethanol, <=4C primary and secondary alcohols, propylene glycol monoethyl ether and diacetone alcohol and using the resultant mixture as the solvent for the coating, and applying the above-mentioned coating by a low-pressure atomization spray method and drying at 40-60 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating film which can be suitably used for preventing reflection of external light on a panel surface, a method for producing the coating film, a coating material thereof, and the like for an electron tube for a television or a computer.

[0002]

2. Description of the Related Art FIGS. 2 and 3 show an electron tube used in a conventional television or computer.

As shown in FIG. 2, a front panel 2 made of glass is formed at the tip of an electron tube 1.

The front panel 2 is required to have an antistatic function for suppressing electromagnetic waves generated from inside the electron tube 1 and an antireflection function for suppressing glare caused by external light. A surface coat 3 configured as follows is provided on the surface of No. 2.

[0005] As shown in FIG. 3, the surface coat 3 has a two-layer structure of an upper layer 4 and a lower layer 5.

The upper layer 4 is formed of silica and has a thickness of about 1.48.
Having a refractive index of

The lower layer 5 is made of a transparent conductive material such as ATO or ITO having an antistatic function, and has a high refractive index of about 2.0.

The refractive index of the front panel 2 made of glass is about 1.52.

As described above, in the electron tube, the upper layer 4 having a low refractive index is formed on the surface of the front panel 2 having a low refractive index via the lower layer 5 having a relatively high refractive index to control the thickness of each layer. Thus, the electron tube 1 is provided with an anti-reflection function.

Therefore, the surface coat 3 has two functions of an antistatic function and an antireflection function.

The upper layer 4 for adding an antireflection function to the surface coat 3 comprises a solid component composed of a silica compound containing either an alkoxide of silica or a siloxane compound, and a solvent in which the solid component is dissolved or dispersed. And, when the solid component is applied with a paint comprising a dispersion containing water necessary for hydrolysis, and dried to evaporate the solvent, the silica compounds generated by the hydrolysis are polycondensed. It is formed.

A typical paint containing a solid component composed of a silica compound is Sumitomo Osaka Cement Co., Ltd.
There is a G-based paint, which is applied by a spin coating method or a high pressure atomization spray method and dried to form a coating film.

[0013]

Problems to be Solved by the Invention AG-based paints are usually used after being diluted with an organic solvent such as ethanol or 1-butanol.

Here, a coating composed of only a single solvent is difficult to control its drying behavior, is difficult to maintain consistency with the drying process, and has a problem in that solids dissolved or dispersed in the coating are difficult. Minutes (nonvolatiles) are more stable to changes over time when dissolved in a mixed solvent than when dissolved only in a single solvent, and the main purpose is to dissolve and disperse solid components. It is known that, in addition to the solvent described above, a solvent that hardly dissolves and disperses the solid component may be added for the purpose of viscosity adjustment, boiling point adjustment, price adjustment, and the like. Therefore, as a solvent constituting the paint,
In general, a mixed solvent obtained by mixing two or more kinds of solvents is often used. For example, a mixed solvent obtained by mixing the above-described organic solvent and water is often used.

However, if the solvent to be mixed is not properly selected, solids dissolved or dispersed in the solvent may precipitate or become unevenly distributed in the mixed solvent. As a result, drying unevenness after application may occur.

Another cause of uneven drying after coating is poor wet spread of the paint. This is considered to be due to the fact that the solvent, which is a moving medium for the solid component, dries faster than it spreads.

The wet spread of the paint is greatly affected by the drying temperature. The higher the drying temperature, the faster the drying speed and the shorter the drying time. However, the coating material is less apt to wet and spread, and drying unevenness tends to occur in the dried coating film.

Conversely, the lower the drying temperature is, the slower the drying speed is, the more easily the paint is wetted and spread, and the less the unevenness of the dried coating film becomes. However, the time required for drying the paint becomes longer than necessary. As a result, when the coating film is used to reflect external light from the electron tube, the production speed of the electron tube is reduced, and the product cannot be obtained efficiently. on the other hand,
Focusing on the coating method of the coating, the spin coating method can form a coating film with relatively little unevenness, but many of the coatings are repelled and discarded. In addition, the high-pressure atomization spray method has little wasteful paint, but liquid components (paint)
However, since a large amount of gas components (mainly air) are mixed, the coating film tends to be uneven. When the AG paint was applied by a high pressure atomization spray method, a coating film with noticeable roughness was formed.

The present invention solves the above-mentioned problems, and provides a paint which can be dried quickly after application, has good wet spread, and does not cause drying unevenness in the coating film after drying. An object of the present invention is to provide a method for producing an anti-reflection coating, an anti-reflection coating formed by the production method, and an electron tube having the anti-reflection coating.

[0020]

In order to achieve the above object, a first aspect of the present invention (corresponding to claim 1) is to dissolve or disperse a solid component containing a silica compound and the solid component. In a paint comprising at least a solvent and a dispersion containing water necessary for the solid component to be hydrolyzed, the solvent comprises (1) methanol, (2) ethanol, and (3) an integer having 4 or less carbon atoms. (4) a secondary alcohol having a carbon number of 4 or less, (5) propylene glycol monoethyl ether,
(6) Of the six groups consisting of diacetone alcohol,
A paint containing at least two types.

The second invention (corresponding to claim 2)
Is a solid component containing a silica compound, a solvent that dissolves or disperses the solid component and a dispersion containing water necessary for the solid component to hydrolyze, wherein the solvent comprises: A paint comprising at least two primary alcohols having an integer of 4 or less carbon atoms or at least two secondary alcohols having an integer of 4 or less carbon atoms.

According to this configuration, the solid component can be homogeneously dissolved or dispersed in the solvent, the uneven distribution of the solid component in the paint can be prevented, and the drying unevenness of the coating film can be suppressed.

The third invention (corresponding to claim 3)
Is a first mixed solvent (parts by weight X1) composed of at least one selected from methanol and ethanol
And a second mixed solvent (parts by weight X2) of at least one selected from primary alcohols having an integer of 4 or less and secondary alcohols having an integer of 4 or less. And a third mixed solvent (parts by weight Y) of at least one selected from the group consisting of the propylene glycol monoethyl ether and the diacetone alcohol, wherein the first mixed solvent and the second mixed solvent The present invention is characterized in that the ratio (X1 + X2) / (Y) of the mixed solvent by weight to the third mixed solvent by weight is in the range of 2/1 to 5/1.

According to this structure, a homogeneous mixed solvent can be obtained, uneven distribution of solid components can be prevented, and drying unevenness of the coating film can be suppressed. Can be shortened.

Further, the fourth invention (corresponding to claim 4)
Is that the third mixed solvent contains both the propylene glycol monoethyl ether and diacetone alcohol, and the weight part of the propylene glycol monoethyl ether is twice the weight part of the diacetone alcohol. The present invention is characterized by the features described above.

According to this configuration, a homogeneous mixed solvent can be obtained, uneven distribution of solid components can be prevented, and drying unevenness of the coating film can be suppressed.

The fifth invention (corresponding to claim 5)
Is a method for producing a coating film, comprising: a coating step of applying the coating material of the present invention described above; and a drying step of drying the applied coating material.

The sixth invention (corresponding to claim 6)
The present invention is the above invention, wherein in the drying step, a drying temperature is in a range of 40 to 60 ° C.

According to this configuration, it is possible to shorten the time for the above-mentioned paint to dry and to improve the spread of the paint.

The seventh invention (corresponding to claim 7)
Is a method for producing a coating film using a paint having a solid component composed of a silica compound and a dispersion containing a solvent for dissolving or dispersing the solid component and water for hydrolyzing the solid component, A method for producing a coating film, comprising a step of applying and drying the paint at an atomizing pressure having an upper limit of 0.1 MPa using a low-pressure atomizing spray method.

According to this configuration, it is possible to reduce the amount of wasted paint as compared with the spin coating method, and to reduce the ratio of the atomizing gas component (air) to the liquid component (paint), thereby reducing the ratio of the high pressure atomizing spray method. Can also form a coating film without unevenness.

The eighth invention (corresponding to claim 8)
Is a coating film characterized by using the above-mentioned method for producing a coating film.

The ninth invention (corresponding to claim 9)
Is a method for manufacturing an electron tube, characterized by using the method for manufacturing a coating film described above, comprising a coating film forming step of forming a coating for preventing external light reflection of the electron tube, A method for producing an electron tube, wherein the method is used in the coating film forming step.

A tenth aspect of the present invention (corresponding to claim 10) is an electron tube characterized in that a coating for preventing external light reflection is formed by using the above-described method for manufacturing an electron tube. An electron tube having a coating film on the surface of the front panel is also included in the present invention.

According to this structure, it is possible to provide an electron tube having a display quality with a coating film having an external light antireflection film formed in a short time.

[0036]

Embodiments of the present invention will be described below.

When the surface coat 3 is formed in the same manner as in FIG. 4 showing the conventional example, a glass plate of 10 cm square is formed in place of the surface glass panel 2 of the electron tube 1, an ITO film is formed in the lower layer 5, and an upper layer 4 is formed. Were prepared by applying and drying the paints of the conventional example and the present invention by a low-pressure atomization spray method.

The paint of the present invention includes ethanol, 1-
Of the five solvents of propanol, 1-butanol, propylene glycol monoethyl ether, and diacetone alcohol, the first three are group (X) (hereinafter referred to as mixed solvent X).
(Parts by weight X)) and the other two groups (Y) (hereinafter referred to as mixed solvent Y (parts by weight Y)), and the upper layer 4 is formed by changing the ratio X / Y of each part by weight. A paint to be formed was made. In addition, about the ratio X / Y of a weight part, it shows similarly in the following Examples. At this time, with respect to two of the mixed solvents Y, a coating material S was prepared by adjusting the weight part of propylene glycol monoethyl ether to be twice the weight part of diacetone alcohol. Further, the solid component in the solvent was a solid component composed of a silica compound containing either one of an alkoxide of silica and a siloxane compound, as in the conventional example, but the same result was obtained if the solid component was a hydrolyzable silica compound. Is obtained. By the way, when forming the surface coat 3, if the refractive index of air is 1 and the refractive index of the glass plate is ng, in order to obtain an ideal antireflection effect, the film thickness of each of the upper layer 4 and the lower layer 5 must be adjusted. It is preferable that the refractive index satisfies the following relational expressions (Expression 1) to (Expression 3).

N2 = n1 × (ng) ^1/2 (Equation 1) n1 × t1 = λ / 4 (Equation 2) n2 × t2 = λ / 4 (Equation 3) where n1 is a coating film forming the upper layer 4 , N2 is the refractive index of ATO or ITO forming the lower layer, t1 is the thickness of the upper layer 4, t2 is the thickness of the lower layer 5, and λ is the wavelength of the incident light.

A surface coat 3 was formed on the surface of a 10 cm square glass plate while adjusting the thickness of each layer so as to satisfy the above relational expression. Then, the visual state of the surface coat 3, the time required for drying, and the antireflection function were evaluated.

Table 1 shows the results.

[0042]

[Table 1] In addition, "wet spread" in the above Table 1 indicates the width of the coating film,
"Surface condition" represents a visual surface condition. The evaluation is a relative evaluation, and ◎,
△, △, × are shown.

When X / Y is smaller than 2, a high boiling point
The solvent of the group (Y), which is a solvent having a low vapor pressure, is strongly affected, and the spread of the wetness is large, but the drying speed is almost the same or slightly lower than the conventional one. Conversely, when X / Y is greater than 5, the solvent of group (X), which is a solvent having a low boiling point and a high vapor pressure, is strongly affected, and the drying speed is much faster than before, but the wet spread is small, and Irregularities easily occur on the film surface.

When X / Y is 2 or more and 5 or less,
The solvent of the group (X) and the solvent of the group (Y) are mixed appropriately, and the coating film after applying the coating material S by spraying has a well-balanced wet spread, drying time and unevenness of the coating film surface. It spreads well, dries relatively quickly, and becomes a coating film without unevenness.

[0045]

Example 1 Next, as specific examples of the paint of the present invention, the results of experiments on 17 compositions are shown in Table 2 below.
Tables 3 and 4 show the results of drying time and wet spread when applied by the high pressure atomization spray method (atomization pressure: 4.0 MPa).
Are shown below.

In Table 2, MeOH: methanol, EtOH: ethanol, 1-PrOH: 1-propanol, 2-PrOH: 2-propanol, 1-Bu
OH: 1-butanol, Iso-BuOH: isobutanol, 2-BuOH: 2-butanol, PGE: propylene glycol monoethyl ether, DAA: diacetone alcohol, respectively.

The following four-stage surface states are defined as indices for indicating the state of the coating film after drying.

AA: There is no unevenness due to drying at all, and the entire coating film is a clear mirror surface.

A: Although drying unevenness remains when carefully observed, no clear streaks or scales are observed, and the entire coating film is a mirror surface.

B: Drying unevenness remains when carefully observed, but no clear streaks or scales are observed. However, a rough feeling was observed on the surface, and the entire coating film was a slightly cloudy mirror surface.

C: Clear streak-like and scale-like drying unevenness has occurred. In addition, the surface has a rough feeling, and the entire surface of the coating film is considerably clouded.

[0052]

[Table 2]

[0053]

[Table 3]

[0054]

[Table 4] In the case of the composition A of the conventional composition (comparative example), which is a mixed solvent composed of ethanol and water, the drying time is short, but the wet spread of the paint is poor, and the surface of the coating film is rough, and streak-like and scale-like drying unevenness occurs. have done.

On the other hand, the coating compositions of compositions B to R were coating films in which the drying behavior was moderated due to the effect of mixing the solvent, and clear streak-like and scale-like drying unevenness was suppressed. However, there are few compositions that can provide a mirror surface without roughness on the coating film surface and can be used as an external light antireflection film for an electron tube. However, the composition that gives a surface state (state B) that gives a slightly cloudy image is used. There were many.

Subsequently, the results of the drying time and the spread of the wetness are shown in Table 5 for the experimental results when the paint having the composition shown in Table 2 is applied by the low-pressure atomization spray method (atomization pressure: 0.5 MPa). And Table 6.

[0057]

[Table 5]

[0058]

[Table 6] As described above, when the low-pressure atomization spray method is used, the drying time is slightly delayed, but the wet spread of the paint is improved.
As a result, drying unevenness hardly occurs on the surface of the coating film,
In addition, the roughness of the coating film surface was suppressed. However, with respect to the composition A of the conventional composition, although improved with respect to the method using a high-pressure atomization spray, drying unevenness occurred and did not reach the level used as an external light antireflection film for an electron tube. .

Incidentally, the above-mentioned examples were used at 40 ° C., 50 ° C., and 6 ° C.
The results for the case of drying at 0 ° C. are shown,
A coating film can be obtained by drying at a temperature other than the above as a method of forming the coating film. However, when the drying temperature is lower than 40 ° C., the coating material spreads well and unevenness is less likely to occur, but the time required for drying becomes longer. When the drying temperature is 6
When the temperature exceeds 0 ° C., the time required for drying becomes shorter, but the wet spread of the paint becomes worse, and unevenness tends to occur. Therefore, the drying temperature is preferably in the range of 40 to 60C.

With respect to the composition O in Table 2, application was performed by a low-pressure atomization spray method at an atomization pressure of 0.05 MPa, and then the drying state was examined by changing the drying temperature within a range of 30 to 70 ° C. Table 7 shows the results.

[0061]

[Table 7] As described above, when the drying temperature is lower than 40 ° C., it takes too much time for drying, and when the drying temperature is higher than 60 ° C., the occurrence rate of drying unevenness rapidly increases.

The results are for the composition O. However, the paints of the present invention, methanol, ethanol,
A primary alcohol having 4 or less carbon atoms, a secondary alcohol having 4 or less carbon atoms, propylene glycol monoethyl ether, and diacetone alcohol; The same applies to other solvent compositions including the solvent composition of the above, or at least two primary alcohols having an integer of 4 or less carbon atoms or secondary alcohols having at least an integer of 4 or less carbon atoms.

In order to check whether or not the coating film thus obtained has an antireflection function, the above-mentioned paint (composition O) was used.
The coating film obtained by applying the low pressure atomization spray method was used to change the wavelength of light in the range of about 400 nm to 700 nm, and the reflectance was measured.

FIG. 1 shows the measurement results of the obtained reflectance.

As shown in FIG. 1, the wavelength of light is 450 nm.
It was found that a high antireflection effect with a reflectivity of less than 1% was obtained in a wide region from 700 nm to 700 nm.

In this embodiment, the description has been made assuming that the paint is applied by the high-pressure atomization spray method and the low-pressure atomization spray method. However, the present invention is not limited to this, and the coating can control the thickness of the coating film. Any other method may be used.

In this embodiment, the surface coat 3 is formed on the surface of a 10 cm square glass panel. However, the same applies to the surface coat 3 formed on the surface of a glass panel for an electron tube.

Next, when the two methods of the high-pressure atomization spray method and the low-pressure atomization spray method are compared as the method of applying the paint for forming the upper layer 4, how the influence on the surface condition of the coating film differs. Was examined in the same manner as in Example 1.

The surface roughness of the lower layer 5 of the coating before the application of the upper layer 4 was 30 nm in both cases.

Table 8 shows the experimental results.

[0071]

[Table 8] When a conventional composition A (comparative example) was applied by a high-pressure atomization spray method, the surface of the upper layer 4 had a large surface irregularity. In addition, the haze is 3.5 and the degree of haze is large, resulting in a vaguely whitish coating film, which cannot be applied as an external light antireflection film for an electron tube.

On the other hand, when applied by the low-pressure atomization spray method, the surface roughness and haze were improved, but still at a level that was difficult to apply as an external light antireflection film for an electron tube.

Both the composition C and the composition O had a surface state that could be used as an external light antireflection film for an electron tube in both the high-pressure atomization spray method and the low-pressure atomization spray method. However, when the low-pressure atomization spray method was used, a coating film having smaller surface roughness and smaller haze could be obtained.

In the case of the high-pressure atomization spray method in which the atomization pressure exceeds 0.1 MPa, the amount of air at the time of application from a spray nozzle for mixing to atomize the paint is large. The drying proceeds until the coating surface is reached, and the wet spread on the coating surface is poor. As a result, the coating film tends to be cloudy, the haze increases, and the transparency of the coating film decreases.

In the above-described method for producing a coating film, the description has been made on the assumption that the atomizing pressure is 0.05 MPa. However, the pressure is such that the paint can be atomized, and the upper limit is 0.1 MPa. It is not necessary to limit to this. However, in order to make the atomization state uniform and stable, 0.01M
The atomization pressure is preferably Pa or more.

In the above-mentioned surface roughness / haze measurement, the results obtained when the compositions C and O were used as examples of the paint of the present invention are shown. Among the six groups consisting of primary alcohols having an integer of 4 or less, secondary alcohols having an integer of 4 or less, propylene glycol monoethyl ether, and diacetone alcohol, at least 2
The same applies to other solvent compositions containing species, or other solvent compositions containing at least two primary alcohols having an integer of 4 or less carbon atoms or secondary alcohols having at least an integer of 4 or less carbon atoms. is there.

In the above-mentioned method for producing a coating film, an example of the low-pressure atomization spray method has been described as being applied using a low-pressure atomization spray nozzle AM45S-IST manufactured by ATOMAX Co., but is not limited thereto. There is no need to use another spray nozzle as long as it is a spray nozzle that can realize application at an atomizing pressure of 0.1 MPa or less.

Although the above examples show the results when dried at 40 ° C., a coating film can be obtained by drying at a temperature other than the above as a method of forming the coating film.
However, when the drying temperature is lower than 40 ° C., the coating material spreads well and unevenness is less likely to occur, but the time required for drying becomes longer. On the other hand, when the drying temperature exceeds 60 ° C., the time required for drying is shortened, but the wet spread of the paint is deteriorated, and unevenness is likely to occur. Therefore, the drying temperature is preferably in the range of 40 to 60C.

[0079]

Example 2 As in Example 1, as specific examples of the above-mentioned paints, the results of the drying time and wet spread when each composition shown in Table 9 was applied by the high-pressure atomization spray method are shown. 10 and Table 11 respectively.

In Table 9, EtOH: ethanol, 1-PrOH: 1-propanol, and PGE: propylene glycol monoethyl ether are shown.

[0081]

[Table 9]

[0082]

[Table 10]

[0083]

[Table 11] As described above, by changing the solvent composition to a three-component system, drying of the solvent became gentle, and almost no drying unevenness occurred on the surface of the coating film. Also, the roughness of the coating film surface was reduced. Here, if the composition was such that X / Y was smaller than 2, drying took too much time. X / Y is 5
When the composition was larger, the spread of wetness became poor, and a rough feeling was generated on the coating film surface.

Subsequently, the results of the drying time and the spread of the wetness are shown in Table 12 for the experimental results when the paint having the composition shown in Table 9 is applied by the low-pressure atomization spray method (atomization pressure: 0.5 MPa). And Table 13 below.

[0085]

[Table 12]

[0086]

[Table 13] As described above, when the low-pressure atomization spray method is used, the drying time is slightly delayed, but the wet spread of the paint is improved.
As a result, drying unevenness hardly occurs on the surface of the coating film,
In addition, the roughness of the coating film surface was suppressed.

Note that the above-mentioned examples were performed at 40 ° C., 50 ° C., and 6 ° C.
The results for the case of drying at 0 ° C. are shown,
A coating film can be obtained by drying at a temperature other than the above as a method of forming the coating film. However, when the drying temperature is lower than 40 ° C., the coating material spreads well and unevenness is less likely to occur, but the time required for drying becomes longer. When the drying temperature is 6
When the temperature exceeds 0 ° C., the time required for drying becomes shorter, but the wet spread of the paint becomes worse, and unevenness tends to occur. Therefore, the drying temperature is preferably in the range of 40 to 60C.

The composition SA in Table 9 was applied by a low-pressure atomization spray method at an atomizing pressure of 0.05 MPa, and the drying state was examined by changing the drying temperature in the range of 30 to 70 ° C. Table 14 shows the results.

[0089]

[Table 14] As described above, when the drying temperature is lower than 40 ° C., it takes too much time for drying, and when the drying temperature is higher than 60 ° C., the occurrence rate of drying unevenness rapidly increases.

The results are for the composition SA. The mixed solvent (X1) comprising at least one selected from methanol or ethanol, which corresponds to the first mixed solvent of the present invention, and the present invention Primary or secondary having an integer of 4 or less, which corresponds to the second mixed solvent of
And at least one solvent selected from the group consisting of propylene glycol monoethyl ether and diacetone alcohol corresponding to the third mixed solvent of the present invention. In the mixed solvent (Y), the sum of the weight parts of the mixed solvent X1 and the mixed solvent X2 is used as the weight part X of the mixed solvent X, and the ratio X of the weight part Y of the mixed solvent X and the weight part Y of the mixed solvent Y is used.
The same applies to other solvent compositions where / Y is in the range of 2/1 to 5/1.

In order to examine whether or not the coating film thus obtained has an antireflection function, the above-mentioned paint (composition S
With respect to the coating film obtained by applying the low pressure atomization spray method using the method A), the reflectance was measured while changing the wavelength of light in a range of about 400 nm to 700 nm.

FIG. 4 shows the measurement results of the obtained reflectance.

As shown in FIG. 4, the light wavelength is 450 nm.
It was found that a high antireflection effect with a reflectivity of less than 1% was obtained in a wide region from 700 nm to 700 nm.

In the present embodiment, the description has been made assuming that the paint is applied by the high-pressure atomization spray method and the low-pressure atomization spray method. However, the present invention is not limited to this, and the coating can control the thickness of the coating film. Any other method may be used.

In this embodiment, the surface coat 3 is formed on the surface of a 10 cm square glass panel. However, the same applies to the surface coat 3 formed on the surface of a glass panel for an electron tube.

Next, when comparing the two types of the high-pressure atomization spray method and the low-pressure atomization spray method as the method of applying the paint when forming the upper layer 4, how the influence on the surface condition of the coating film differs. Was examined in the same manner as in Example 1.

The surface roughness of the lower layer 5 of the coating film before application of the upper layer 4 was 30 nm in both cases.

Table 15 shows the experimental results.

[0099]

[Table 15] In the case of the composition SA, both the high-pressure atomization spray method and the low-pressure atomization spray method were able to obtain a coating film having sufficient transparency to be applied as an external light antireflection film for an electron tube, that is, a coating film having a small haze. In particular, when the low-pressure atomization spray method was used, a low-haze coating film of 2.4 could be obtained.

In the above-mentioned method for producing a coating film, the description has been made on the assumption that the atomizing pressure is 0.05 MPa. However, the pressure is such that the paint can be atomized, and the pressure is not more than 0.1 MPa. It is not necessary to limit to this. However, in order to make the atomization state uniform and stable, 0.01M
The atomization pressure is preferably Pa or more.

In the above-described surface roughness and haze measurement, the results obtained when the composition SA was used as an example of the coating material of the present invention are shown. However, methanol or methanol, which corresponds to the first mixed solvent of the present invention, is used. A mixed solvent (X1) composed of at least one selected from ethanol, and at least one selected from primary or secondary alcohols having an integer of 4 or less and corresponding to the second mixed solvent of the present invention. A mixed solvent (X2) composed of one kind and a mixed solvent (Y) composed of at least one kind selected from the group consisting of propylene glycol monoethyl ether and diacetone alcohol, which corresponds to the third mixed solvent of the present invention. In the above, the sum of the weight parts of the mixed solvent X1 and the mixed solvent X2 is used as the weight part X of the mixed solvent X, and the ratio X / Y of the weight part X and the weight part Y of the mixed solvent Y is 2 / The same applies to the other solvent composition in the range of 5/1.

In the above-described method for producing a coating film, an example of the low-pressure atomization spray method has been described as being applied using a low-pressure atomization spray nozzle AM45S-IST manufactured by ATOMAX, but is not limited thereto. There is no need to use another spray nozzle as long as it is a spray nozzle that can realize application at an atomizing pressure of 0.1 MPa or less.

Although the above examples show the results when dried at 40 ° C., a coating film can be obtained by drying at a temperature other than the above as a method of forming the coating film.
However, when the drying temperature is lower than 40 ° C., the coating material spreads well and unevenness is less likely to occur, but the time required for drying becomes longer. On the other hand, when the drying temperature exceeds 60 ° C., the time required for drying is shortened, but the wet spread of the paint is deteriorated, and unevenness is likely to occur. Therefore, the drying temperature is preferably in the range of 40 to 60C.

[0104]

Example 3 As in Example 1, as specific examples of the above-mentioned paints, the results of drying time and wet spread when each composition shown in Table 16 was applied by the high-pressure atomization spray method were shown. 17 and Table 18 respectively.

In Table 16, EtOH: ethanol, 1-PrOH: 1-propanol, PGE: propylene glycol monoethyl ether, and DAA: diacetone alcohol are shown, respectively.

[0106]

[Table 16]

[0107]

[Table 17]

[0108]

[Table 18] The drying property and the wet spreading property of the composition T, the composition TA, and the composition TB were almost equal. However, in the case of a coating film obtained from a coating material having a composition T in which the composition ratio of PGE and DAA is PGE: DAA = 2: 1, the coating film is a clear coating film in which no drying unevenness is observed. The coatings obtained from the paints of the composition TA and the composition TB have a level that can be applied as an anti-reflection coating for external light of an electron tube, but have slight drying unevenness in several places, and the coating is slightly cloudy. Met.

Tables 19 and 20 show the results of the drying time and the spread of the wetness, respectively, of the experimental results when the paints shown in Table 16 were applied by the low-pressure atomization spray method.

[0110]

[Table 19]

[0111]

[Table 20] As in the case where the high-pressure atomization spray method was used, the drying property and the wet spreading property of the composition T, the composition TA, and the composition TB were almost the same. However, when the composition ratio of PGE and DAA is PGE: D
In the case of a coating film obtained from a coating material having a composition of AA = 2: 1, a clear coating film in which no drying unevenness is observed was obtained, whereas a coating film having a composition of TA and composition TB was obtained. Although the coated film is at a level that can be applied as an anti-reflection film for external light of an electron tube, thin dry unevenness has occurred in several places, and the film was slightly cloudy.
In the above embodiment, the description has been made assuming that the paint is applied by the high-pressure atomization spray method and the low-pressure atomization spray method.
It is not necessary to limit to this, and any other coating method may be used as long as the coating method can control the thickness of the coating film.

In the above embodiment, the surface coat 3 was formed on the surface of a 10 cm square glass panel. However, the same applies to the surface coat 3 formed on the surface of a glass panel for an electron tube.

In the above examples, the results obtained when using the composition T, the composition TA and the composition TB as examples of the coating material of the present invention are shown, but using propylene glycol monoethyl ether and diacetone alcohol as solvents. The same applies to paints of other compositions including the same.

Next, when the two methods of the high-pressure atomization spray method and the low-pressure atomization spray method are compared as a method of applying the paint when forming the upper layer 4, how the influence on the surface state of the coating film differs. Was examined in the same manner as in Example 1.

The surface roughness of the lower layer 5 of the coating film before application of the upper layer 4 was 30 nm in both cases.

The results of the experiment are shown in Table 21.

[0117]

[Table 21] As described above, in both the composition T and the composition TA, even when using either the high-pressure atomization spray method or the low-pressure atomization spray method, it is possible to obtain a coating film with little drying unevenness and a small haze (a small degree of haze). Was completed. In particular, when the paint of the composition T was applied using the low-pressure atomization spray method, a coating film having the best surface condition and a low haze could be obtained.

In the above-described method for producing a coating film, the description has been made on the assumption that the atomizing pressure is 0.05 MPa. However, the pressure is such that the paint can be atomized, and the upper limit is 0.1 MPa. It is not necessary to limit to this. However, in order to make the atomization state uniform and stable, 0.01M
The atomization pressure is preferably Pa or more.

In the above measurement of the surface roughness and haze, the results obtained when the composition T and the composition TA are used as examples of the paint of the present invention are shown. The same applies to paints of other compositions containing at least diacetone alcohol as a solvent.

In the above-described method for producing a coating film, as an example of the low-pressure atomization spray method, the description has been made assuming that the low-pressure atomization spray nozzle AM45S-IST manufactured by ATOMAX Co. is applied, but the invention is not limited to this. There is no need to use another spray nozzle as long as it is a spray nozzle that can realize application at an atomizing pressure of 0.1 MPa or less.

Although the above examples show the results when dried at 40 ° C., a coating film can be obtained by drying at a temperature other than the above as a method of forming the coating film.
However, when the drying temperature is lower than 40 ° C., the coating material spreads well and unevenness is less likely to occur, but the time required for drying becomes longer. On the other hand, when the drying temperature exceeds 60 ° C., the time required for drying is shortened, but the wet spread of the paint is deteriorated, and unevenness is likely to occur. Therefore, the drying temperature is preferably in the range of 40 to 60C.

As described above, according to the coating material in each embodiment of the present invention, the solid component composed of the silica compound can be uniformly dissolved or dispersed in the solvent, and the uneven distribution of the solid component in the coating material can be prevented. In addition, drying unevenness of the coating film can be suppressed.

In addition, according to the paint of the present invention, the drying time can be shortened to shorten the time required for forming a coating film.
Since the wet spread of the paint is good, it is possible to suppress drying unevenness that occurs in the coating film after drying.

Further, according to the method for producing a coating film of the present invention,
A coating film is formed while controlling the temperature using the coating material of the present invention, and by using a low-pressure atomization spray method as a coating method of the coating material, the coating film having an anti-reflection function for external light can be formed in a short period of time. It can be manufactured without it.

The coating film of the present invention is produced by the above-mentioned method for producing a coating film of the present invention, has an external light reflection preventing function, can be produced in a short time, and has no unevenness due to drying.

According to the method for manufacturing an electron tube of the present invention, an anti-reflection coating for external light is formed on the surface of the electron tube by using the method for manufacturing a coating of the present invention. An electron tube having a film and good display quality can be manufactured in a short time.

The electron tube of the present invention is manufactured by the above-described method for manufacturing an electron tube of the present invention, and can be manufactured in a short time while providing an anti-reflection coating for external light on the surface of the electron tube. Are better.

[0128]

As described above, according to the present invention, a coating film having an external light reflection preventing function can be obtained, and an electron tube provided with the coating film and having excellent display quality can be produced in a short time. Can be manufactured.

[Brief description of the drawings]

FIG. 1 is a diagram showing the reflectance of a surface coat in Example 1 of the present invention.

FIG. 2 is a configuration diagram of a conventional electron tube.

FIG. 3 is a configuration diagram of a conventional surface coat.

FIG. 4 is a diagram showing the reflectance of a surface coat in Example 2 of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electron tube 2 Surface panel 3 Surface coat 4 Upper layer 5 Lower layer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J038 DL031 JA18 JA20 JA26 JA34 MA08 MA10 NA19 PA06 PA19 PB09 5C028 AA10 5C032 AA01 DD02 DF01 DG01

Claims (10)

[Claims] 1. A paint comprising at least a solid component containing a silica compound, a solvent containing the solid component dissolved or dispersed therein, and a dispersion containing water necessary for the solid component to undergo hydrolysis. The solvents are (1) methanol, (2) ethanol,
(3) a primary alcohol having a carbon number of 4 or less,
(4) a secondary alcohol having a carbon number of 4 or less;
(5) propylene glycol monoethyl ether,
(6) Of the six groups consisting of diacetone alcohol,
A paint comprising at least two types. 2. A paint comprising at least a solid component containing a silica compound, a solvent dissolving or dispersing the solid component, and a dispersion containing water necessary for the solid component to undergo hydrolysis. A coating material characterized in that the solvent contains at least two primary alcohols having an integer of 4 or less carbon atoms, or at least two secondary alcohols having an integer of 4 or less carbon atoms. 3. A first mixed solvent (parts by weight X1) comprising at least one selected from the group consisting of methanol and ethanol, a primary alcohol having an integer of 4 or less, and a primary alcohol having a carbon number of 4 or less. A second mixed solvent (parts by weight X2) of at least one selected from secondary alcohols that is an integer of 4 or less; and at least one selected from the group consisting of propylene glycol monoethyl ether and diacetone alcohol. A third mixed solvent (parts by weight Y) of one kind, and a ratio (X1 + X2) / (parts by weight) of the first mixed solvent and the second mixed solvent to the third mixed solvent by weight.
The paint according to claim 1, wherein (Y) is in the range of 2/1 to 5/1. 4. The third mixed solvent contains both the propylene glycol monoethyl ether and diacetone alcohol, and the weight part of the propylene glycol monoethyl ether is twice the weight part of the diacetone alcohol. The paint according to claim 3, wherein the paint is provided. 5. A method for producing a coating film, comprising: an application step of applying the coating material according to claim 1; and a drying step of drying the applied coating material. 6. The drying step, wherein the drying temperature is 40.
The method for producing a coating film according to claim 5, wherein the temperature is within a range of from 60C to 60C. 7. Production of a coating film using a paint having a solid component comprising a silica compound, and a dispersion containing a solvent for dissolving or dispersing the solid component and water for hydrolyzing the solid component. The method of claim 1, wherein the paint is sprayed at 0.1 MPa using a low pressure atomization spray method.
A method for producing a coating film, comprising a step of applying and drying with an atomizing pressure having an upper limit of. 8. A coating film formed by the method for producing a coating film according to claim 5. 9. A method for manufacturing an electron tube, comprising using the method for manufacturing a coating film according to claim 5, wherein a coating for preventing external light reflection of the electron tube is formed. A method for manufacturing an electron tube, comprising a coating film forming step, wherein the method for manufacturing a coating film is used in the coating film forming step. 10. An electron tube manufactured by using the method for manufacturing an electron tube according to claim 9.