KR830000490B1 - Method of Forming Powder Coating Layer - Google Patents

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Description

Method of Forming Powder Coating Layer

1A, 1B, 1C, 1D, 1E, 1F, 1G, and 1H are cross-sectional explanatory views of the powder coating layer for explaining the present invention.

The present invention relates to a method for forming a figure powder coating layer, and more particularly to an improved method for stably forming a shape powder coating layer.

On the inner surface of the screen portion (face plate) of the color CRT, three kinds of phosphors emitting red, green, and blue light are coated in dots or stripes. The conventional method of forming this phosphor coating layer is as follows. First, a layer of a mixture of a first color phosphor such as a green luminescent phosphor and a photosensitive resin is formed on the inner surface of the face plate. As the photosensitive resin, a mixture of polyvinyl alcohol and ammonium dichromate is usually used.

This layer is usually formed by applying a mixture of a photosensitive resin and a phosphor to the inner surface of the face plate and drying it. This layer is then irradiated with ultraviolet light through the holes in the shadow mask.

At this time, the irradiation position of the ultraviolet rays corresponds to the position where the electron beam for emitting the phosphor emits, that is, the position to which the phosphor should adhere. The part which received this ultraviolet irradiation insolubilizes the photosensitive resin, and the whole layer of this part insolubilizes. Next, the layer is washed with a solvent (usually water) and irradiated with ultraviolet rays, so that only the insolubilized portion remains on the face of the faceplate, and the other layers are dissolved and removed. Next, the same operation is performed using a layer of a mixture of the second color phosphor, for example, a blue luminescent phosphor and a photosensitive resin. The same operation is performed using a mixture of a third color phosphor, for example, a red luminescent phosphor and a photosensitive resin.

As can be understood from the above description, the simplification is very desirable because the manufacturing process of the fluorescent surface of the color CRT is complicated and requires many times of wet coating, washing and drying.

Therefore, the inventors of the present invention have previously proposed a method for forming the fluorescent surface of the color-brown tube in a more remarkable and simple process than the conventional element 52-41465. This method has been completed on the basis of the novel view that the photodegradation product of aromatic diazonium salt has the capacity of powder particles, and in the method of forming a graphical powder coating layer on the surface of gas, (1) Aromatic diazonium salt The 1st process of apply | coating to the surface of a base the photosensitive composition which produces adhesiveness by the furnace light containing aromatic diazonium salt as a photosensitive component to make it a thin layer, and shape it into a thin layer. And (3) a third step of bringing the powder particles into contact with the thin layer after the luminous process to cause adhesion to the luminescent part, and accommodating the powder particles in the thin layer according to the powder capacity of the thin layer. .

In the production of the fluorescent surface of the color CRT, the second and third steps described above are repeated with respect to the second and third color phosphors to form a third color phosphor pattern.

However, the powder coating layer formed by such a method is not mechanically strong and is removed from the coating substrate relatively easily by water washing in particular. The reason for this is that the powder coating layer forms a deliquescent liquid such as zinc chloride generated as a result of the photolysis reaction of the photosensitive adhesive material (aromatic diazonium salt) as a binder, and the binder I am water soluble.

In order to solve this problem, a method of fixing the powder coating layer by contacting with ammonium or the like has also been proposed.

Fixation by this method has a weak point that also acts on the labyrinth light portion. Therefore, in the production of the fluorescent surface of the color CRT, when the first color phosphor is applied and then the ammonia fixation is performed, the powder acceptability of the part is low and the powder is low even when the second furnace for applying the second color phosphor is applied. Only a little bit of deposition or no deposition at all. Therefore, ammonia fixation needs to be performed after three colors have deposited phosphors, respectively.

In this case, the following mixed color problem occurs. That is, when the phosphor of the first color and the phosphor of the second color are deposited when the phosphor of the first color is not sufficiently deposited, the powder accommodating capacity remains at the position where the phosphor of the first color should be deposited. Phosphors of the second color are deposited in small amounts to produce mixed colors. In order to prevent this, for example, a method of sufficiently depositing the first color phosphor, etc. has to be taken, and it has been found that the working time becomes long.

An object of the present invention is to provide an improved method for forming a graphical powder coating layer.

Another object of the present invention is to provide a method for enabling the powder to be fixed every time one kind of powder is applied.

Still another object thereof is a method of forming a graphical powder coating layer on a surface of a substrate, which comprises: (1) a photosensitive composition which generates adhesiveness by furnace light containing an aromatic diazonium salt or an aromatic diazonium salt as a photosensitive component. Is applied to the surface of the substrate to form a thin layer, (2) a second step of generating a sticky shape on the thin layer to generate adhesiveness, and (3) the powder layer is brought into contact with the thin layer after the furnace is lit. The third step of forming the powder coating layer by accommodating the powder particles in the thin layer according to the powder capacity of the thin layer; (4) a powder which reacts with the photolysis product of the aromatic diazo salt leaf to produce a water-insoluble or poorly water-soluble solid substance. And a fourth step of bringing the phase material into contact with the powder coating layer.

The present invention is mixed with a powder to be applied to a product by photolysis reaction of an aromatic diazonium salt, such as zinc chloride, to produce a water-insoluble or poorly water-soluble solid material or to apply the powder after formation of the powder coating layer. By coating the layers repeatedly, some or all of the zinc chloride is changed to a water-insoluble or poorly water-soluble solid material to form a powder coating layer that is non-tacky and mechanically strong and resistant to washing with water. .

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

In the drawings, the present invention passes through the states of Figs. 1a, 1b, 1c, 1d, 1e, or 1a, 1a, 1b, 1c, 1f, 1g, and 1g. And through each state of FIG. 1h.

Referring to the former embodiment, as shown in Figs. 1A and 1B, a film 2 of the photosensitive composition is formed on the substrate 1, and the portion of the photosensitive composition, which is light-emitting on the figure as shown in Fig. 1C, is emitted. (2 ') has adhesiveness by the production of zinc chloride.

To this is given a mixture of the powder 3 of the substance reacting with zinc chloride and the powder particles 4 to be applied as shown in FIG. 1d. As a result of the reaction between zinc chloride and zinc chloride, a solid material (5) is produced as shown in FIG. 1e, thereby making it non-tacky and firmly adhering the powder particles (4) to the substrate.

In the latter method, after the coating layer of the powder particles 4 is formed as shown in FIG. 1f, a powder 3 of a substance that reacts with zinc chloride is applied as shown in FIG. In addition, the solid material (5) is generated by non-tackiness while the solid material crosses the powder particles firmly on the substrate.

It is preferable to perform the above-mentioned fixing every time the three-color phosphors are applied in the production of color CRT only.

However, the present invention also includes applying the three colors of phosphors, that is, performing steps 1c and 1f with respect to the three colors of phosphor, respectively, and then fixing them at one time by performing the steps shown in FIGS. 1g and 1h. This is because any kind of surface-treated phosphor reaches a sufficient powder coating amount in a relatively short time of application, and there is no fear of mixing with respect to the powder coating layer. Therefore, for example, the method of the present invention may be performed once or twice using such a phosphor in the first and / or second colors.

By any of the above methods, it is possible to form a mechanically strong and water-resistant powder coating layer.

The powdery substance which reacts with the product by the photolysis reaction of the aromatic diazonium salt to produce a water-insoluble or poorly water-soluble solid substance may be appropriate depending on the aromatic diazonium salt used. The aromatic diazonium salt which generate | occur | produces adhesiveness by furnace light is described in the said special element 52-41465. One example is aromatic diazonium chloride and zinc chloride double salt, which are produced by the photolysis reaction.

If such a compound is shown in more detail, for example,

4-dimethylaminobenzenediazonium chloride-(1).

Zinc chloride salt ((CH ₃ ) ₂ NC ₃ H ₄ N ₂ Cl.ZnCl ₂ ), 4-diethylaminobenzenediazonium chloride-(1).

Zinc Chloride Salt,

4-chloride (N-ethyl-N-hydroxyethylamino)

Benzenediazonium- (1). Zinc Chloride Salt,

Anthraquinone diazonium chloride-(1). Double Chloride,

2-methoxy 4-nitrobenzenediazonium chloride-(1).

Zinc Chloride Salt,

4-nitronaphthalenediazonium chloride- (1). Zinc Chloride Salt,

4-methoxybenzenediazonium chloride-(1) zinc chloride salt,

2-methoxybenzenediazonium chloride-(1).

Zinc chloride salts;

Examples of powdered solid materials which react with zinc chloride, which is a product of photolysis reaction of these compounds, in an aqueous solution to produce a water-insoluble or poorly water-soluble substance are as follows. That is, they are alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal oxides, bicarbonates of alkali metals, ammonium carbonate, alkali metal borates, alkali metal silicates, alkali metal chromates, ammonium chromates, alkali metal phosphates, ammonium phosphates, and alkali metal emulsions. And ammonium emulsifiers, alkali metal fetocyanides, alkali metal oxalates, ammonium oxalates, alkali metal salts of higher fatty acids such as alkali metal oleate salts, alkali metal stearates, and the like.

Practically particularly preferred among the above materials are those which can be easily micronized and stable in air and they are, for example, calcium hydroxide, sodium bicarbonate, sodium carbonate, sodium oxalate, ammonium oxalate and the like.

Other aromatic diazonium salts include aromatic diazonium acid lactates. As the compound of this system, for example,

Lactic acid 4-dimethylaminobenzenediazonium-(1),

Lactic 4-diethylaminobenzenediazonium-(1),

Lactic acid 4- (phenylamino) benzenediazonium- (1), and the like.

Examples of powdered solid materials which react with lactic acid, which is a photodegradation reaction product of these compounds, in an aqueous solution to produce a water-insoluble or poorly water-soluble substance include alkaline earth metal hydroxides, alkaline earth metal oxides and carbonates, acetates and chlorides of alkaline earth metals.

Particularly preferred among the above materials in practical use are those that are readily micronized and stable in air and they are, for example, calcium hydroxide, calcium carbonate, calcium acetate and the like.

The photosensitive composition to be used in the present invention is 0.5 to 500% by weight (as described below for aromatic diazonium salts), for the purpose of improving coating properties at one time, as described in application 52-41465. Preferably it contains 1 to 50% by weight of the organic polymer compound.

Such organic polymer compounds include gum arabic, polyvinyl alcohol, polyacrylamide, poly (N-vinylpyrrolidone), acrylamide, diacetone acrylamide copolymer, methyl vinyl ether, maleic anhydride copolymer, algilic acid, yl At least one organic polymer compound selected from the group consisting of propylene propylene glycol ester, hydroxypropyl, and methyl cellulose is used.

On the other hand, the photosensitive composition used for this invention can add various surfactant in order to improve coating property once, etc. as a coating material.

It is already well known to add surfactant for achieving such an object, and the surfactant used in such a known method can also be used in the present invention.

The preferable addition amount of surfactant is about 0.01 to 1% with respect to a diazonium salt.

Japanese Patent Application No. 52-41465 also describes a method for depositing more powder in a thin layer. In this method, the powder is deposited in a thin layer, followed by contacting the powder coating layer with alcohol or a vapor such as isopropyl alcohol, ethanol, acetone, methyl ethyl ketone, and then drying the powder coating layer to obtain the same powder as the powder. It is a method of contacting a powder coating layer once again. This invention also includes performing this method. That is, the process of FIG. 1f includes only the case where the powder is deposited on the thin layer only once, after the powder is deposited on the thin layer, more powder is deposited by the above method.

In the present invention, it is preferable to apply the powder which reacts with the zinc chloride solution to produce a water-insoluble or poorly water-soluble solid substance, and then to dry the coating layer by a method such as contacting with high humidity air. .

This is because the reaction between the powder and zinc chloride proceeds rapidly in the wet state.

Hereinafter, the present invention will be described in more detail with reference to the following examples.

Example 1

An aqueous solution having the following composition (1) was applied to a glass surface plate by a rotary coating method of 500 revolutions per minute, dried by infrared heating to form a photosensitive thin layer having a thickness of about 0.2 μm.

This photosensitive thin layer was irradiated with light of 50mw / cm 2 intensity in an ultra-high pressure mercury lamp for 30 seconds through the hole of the shadow mask for color-brown tubes. Next, the blue luminescent fluorescent substance powder for color-brown tubes was apply | coated to the surface of this photosensitive thin layer by dusting. That is, the phosphor powder was scattered on the surface of the thin layer, the phosphor powder was attached to the light-emitting portion of the thin layer, and the remaining phosphor particles were removed by air spraying.

Next, a fine powder of sodium hydrogen carbonate was applied on the surface of the photosensitive thin layer and the phosphor coating layer by dusting, after which excess powder was removed by air spray.

The fine powder of sodium hydrogen carbonate used at this time is manufactured by the following operation. That is, 20 g of sodium hydrogen carbonate was dissolved in 23.0 g of water, and 50 ml of muethanethanol was added thereto while stirring, and the resulting precipitate was filtered off and dried over anhydrous calcium chloride to obtain fine powdered sodium hydrogen carbonate.

Subsequently, air saturated with water vapor at 40 ° C. was brought into contact with the powder coating layer to make the coating layer wet, and then allowed to stand in air to dry naturally.

In this way, a phosphor coating layer firmly fixed on the glass substrate was obtained. This phosphor coating layer exhibited sufficient resistance to water washing by the flow of water.

And the same result was obtained also when it was left to stand for about 20 minutes without contacting saturated air with water vapor.

In addition, even if a phosphor that emits light of a different color is applied onto the phosphor coating layer, there is no problem of mixed color in which the phosphor is not deposited again.

The phosphor coating layer obtained as a result of performing the same conditions as the above except performing dusting of sodium hydrogen carbonate with respect to the above was not completely endured with water washing by the flow of water, and was completely removed by washing with water.

Example 2

The same composition as in Example 1 was formed on the glass substrate by the same rotary operation, and the same light emission as in Example 1 was performed.

Next, the phosphor composition of the following composition (2) was apply | coated to the surface of this photosensitive thin layer by dust similar to Example 1.

By this operation, a mixed powder coating layer of a phosphor and sodium hydrogen carbonate was formed in the furnace part of the photosensitive thin film.

Next, the powder coating layer was wetted and dried in the same manner as in Example 1 to obtain a powder coating layer firmly fixed on a glass substrate. It was confirmed that this powder coating layer had sufficient resistance to water washing by the flow of water.

Example 3

In place of sodium hydrogen carbonate in Example 1, (1) sodium carbonate powder, (2) calcium hydroxide powder, and (3) sodium oxalate powder were used, and otherwise, by the same operation using the same composition phosphor as in Example 1 When the powder coating layer was formed on the glass substrate, it was found that even when powders were used in any of (1), (2) and (3), the formed coating layer had sufficient resistance to washing with water flow.

The sodium carbonate of (1) was prepared by heating sodium hydrogen carbonate prepared by the method described in Example 1 at 220 ° C. in air for 30 minutes, and the calcium hydroxide of (2) was purchased as a reagent. The sodium oxalate powder of (3) was pulverized very thinly as a fluid of menow which was purchased as a reagent.

Example 4

A powder coating layer was formed using the same materials and operations as in Example 2, except that the following Composition (3), Composition (4) and Composition (5) were used instead of the composition of Composition (2) in Example 2. When using any of composition (3), composition (4) and composition (5), it was confirmed that a powder coating layer having sufficient resistance to washing with water flow was obtained.

And the same result was obtained by using sodium oxalate and other things such as ammonium phosphate.

Example 5

The photosensitive thin layer was formed using the following composition (6) in place of the composition (1) in Example 1, and then replaced with the composition (2) in Example 2, using the following composition (7). Similar results were obtained.

In addition, almost the same results were obtained when using other than calcium hydroxide.

In addition, using the green and red luminescent phosphors instead of the blue luminescent phosphors, the same operation was carried out as follows to obtain the same results.

Claims (1)

In the method for forming a graphical powder coating layer on the surface of the base (1), by applying a photosensitive composition that generates adhesiveness by the furnace light containing an aromatic diazonium or an aromatic diazonium salt as a photosensitive component on the surface of the base (1) The first step of forming a thin layer, the second step of generating light-adhesiveness on the thin layer to generate adhesiveness, and the powder particles 4 are brought into contact with the thin layer after the light-receiving, so that the powder particles are in accordance with the powder containing capacity of the thin layer. The third step of accommodating (4) in a thin layer to form a powder coating layer and contacting the powder coating layer with a powdery substance which reacts with the photolysis product of the aromatic diazonium salt to produce a water-insoluble or poorly water-soluble solid substance (5). And a fourth step of making the powder-coated powder layer.

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