JPS63141238A - Method of forming filming membrane in color - Google Patents

Abstract

PURPOSE:To eliminate watering spots of a filming membrane, and to reduce the generation of an uneven brightness consequently, by composing a solution of inorganic substance, of a specific wt% of ortho-boric acid, a specific wt% of ethanol or methanol, and the remaining % of water. CONSTITUTION:The composition of a solution including ortho-boric acid is composed of 0.5 to 4 wt% of ortho-boric acid, 10 to 55 wt% of methanol or ethanol, and the remaining % of water. As a result, the drying speed of the ortho-boric acid sprayed on a filming membrane is made faster, the moisture is not accumulated, and the watering is not made easily. Consequently, the spotty unevenness of the brightness caused from the watering is rarely generated.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention provides a filming film in which inorganic microcrystals are uniformly distributed and adhered to the surface of the filming film formed on the fluorescent surface of a color cathode ray tube. Formation method This is a diagram for explaining the process of forming an aluminum film on the fluorescent surface of a tube.As shown in FIG. After forming the matrix (2) and the phosphor layer (3), as shown in FIG. ), and while rotating this panel (1) with a motor (4a), pour a filming liquid (6) containing acrylic emulsion as a main component from a nozzle (5) and apply it. Next, after rotating it at high speed and shaking off the excess filming liquid, as shown in Fig. 8, washing water (8) is poured from the nozzle (7) onto the inner surface (xb) of the panel skirt part. Then, while washing off the sealminder liquid (6) from the position where no filming film is needed on the inner surface (1b) of the panel skirt part to the sealing surface (IC), apply the filming liquid (6) using an infrared heater (9).
) is heated and dried, and as shown in FIG. 4, a filming film α0 is formed by stirring and smoothing the surface of the phosphor layer (3).

Next, as shown in FIG. 5, an aqueous solution of orthoboric acid is applied to the surface of the filming film αQ using a two-fluid spray gun σ◆ toward the surface of the filming film α of the rotating panel (1). (to) is sprayed and dried to precipitate flaky orthoboric acid microcrystals from the aqueous solution adhering to the surface of the filming film GO.

Next, place this pile (1) on a vacuum evaporation device so that the panel inner surface (1a) becomes the wall of the vacuum chamber, and
After evacuation to a vacuum level of 10 PH, a predetermined amount of aluminum metal is melted and evaporated by resistance heating, and as shown in FIG. Form an aluminum thin film (g) with pinholes.

During the above process, the purpose of depositing microcrystals of orthoboric acid on the filming film QQ and forming pinholes with an appropriate density in the aluminum film (T) is to form the phosphor layer (3) and During the heating process in which the organic matter contained in the filming film α0 is thermally decomposed at approximately 420°C in an oxidizing atmosphere, the decomposed gas generated pushes the aluminum film (T) up from the phosphor layer (3). pinhole C1l without causing the so-called blistering phenomenon that causes peeling.
This is to gradually dissipate it through the air.

) is formed on the aluminum film using this method, the risk of blistering is extremely low, so the drying conditions in the previous filming film forming step 3 can be strengthened to further increase the tension of the filming film <10. The aluminum film (
The smoothness of the phosphor 1111 (g) is also improved, and the light emitted from the phosphor 1111 (3) is efficiently reflected by the aluminum film (1) and radiated to the outer surface of the panel, thereby improving the brightness of the phosphor surface.

[Problem that the invention attempts to solve]

However, in the conventional process of forming boric acid microcrystals, an aqueous solution of orthoboric acid is sprayed, so after the sprayed mist adheres to the filming film α0, the water evaporates and forms boric acid microcrystals (very small). ) takes a long time to precipitate, so depending on the density and amount of mist sprayed onto the filming film qQ, water-wet conditions tend to occur, and as a result,
The filming film σQ swells in the water-wetted area, resulting in poor tension, and this often causes problems such as uneven brightness in this area, which hinders the productivity of this process.

This invention was made to solve these problems, and it is a filming film that precipitates uniformly dispersed orthoboric acid microcrystals without causing water spots on the filming film. The purpose is to obtain a formation method.

[Means for solving problems]

The method for forming a filming film according to the present invention includes forming a filming film on a phosphor layer, and then spraying a solution of orthoboric acid onto the surface of the film to generate microcrystals.
A method for forming a filming film, characterized in that the solvent of the solution is ethanol or a mixture of methanol and water, and the solution is sprayed while the temperature of the inner surface of the panel is increased to 40 to 70 ° C. be.

[Effect]

Since the orthoboric acid solution in this invention contains an alcohol component, the mist sprayed onto the filming film dries quickly, and moisture accumulation does not occur, making it difficult for water wetting to occur. As a result, the occurrence of spot-like brightness unevenness due to water wetting is reduced, and productivity is improved.

[Embodiments of the invention]

Examples of the present invention will be described below.

A filming liquid mainly composed of water-soluble acrylic emulsion is applied onto the phosphor layer (3) on the inner surface of the panel (1a), and after drying, the solvent and composition of the orthoboric acid solution are sprayed onto the film. The table below shows the results of investigating the occurrence of water wetting under various coating conditions by varying the ratio and increasing/decreasing the amount of spray 4 at the same time.

In the table, the injection time and the amount of liquid sprayed per spray gun are the conditions of the apparatus shown in FIG. The air pressure in L4 was 2.5 kg/d.

When the orthoboric acid (H3BO8) of Conventional Example 1 is a 2 wt% aqueous solution, the injection time is 10 seconds and the injection liquid volume is 0.8 m
Under the conditions of 1.1 tsl, no water spots were observed on the filming crotch, but when the amount of liquid in Conventional Example 2 was increased to 1.1 tsl, the evaporation of the liquid was delayed and uneven spots appeared on the screen. did. On the other hand, as in Examples 1 and 2, 2. When using a solution of methanol mixed at a weight ratio of 10° and water of 88, the injection time was increased to 15 to 20 seconds and the amount of injection liquid was increased to 1.1 to 1.5 zl. Acid microcrystals could be uniformly dispersed and formed on the filming crotch.

Furthermore, as in Examples 8 to 6, orthoboric acid was added to 2 and ethanol was added to 35 to 55. Even when using a solution prepared with the remaining amount as water, the injection time is 15 to 20 seconds,
Even when the amount of liquid injected was increased to 16 ml, no abnormality occurred, and microcrystals of orthoboric acid could be uniformly dispersed and precipitated.

The optimum pupil circumference for the amount of liquid to be sprayed varies somewhat depending on the conditions of the spray gun, i.e. solid angle of spray, spray area, etc., but based on the size and density of the microcrystals, it is 0.6 to 1.2.
ml range is preferable, and therefore, a spraying method that does not cause uneven coating in this area is desirable.

From the above results, by adding 10 to 55 weight percent of alcohol to the solvent as the composition of the boric acid solution,
It has become possible to deposit microcrystals without uneven coating over the entire optimum range of spray amount.

In addition, the panel temperature when spraying this solution was set to 35°C.
When the effect of not raising the temperature to ~70°C was investigated, it was found that when the temperature is below about 40°C, the drying rate of the mist droplets is slow, so that water wetting phenomenon tends to occur.

〔Effect of the invention〕

As explained above, this invention forms a smooth filming film on the surface of a phosphor layer formed on the inner surface of a panel, and then sprays a solution containing orthoboric acid and dries the film. In the filming film forming step of precipitating microcrystals of orthoboric acid on the film, the composition of the solution is changed to 0.5 to 4% by weight of orthoboric acid and 10 to 4% by weight of orthoboric acid.
It is characterized by containing 55% by weight of methanol or ethanol and the remaining amount of water, and the drying speed of the orthoboric acid solution sprayed onto the filming film is increased, so that the filming film is not wet with water. As a result, the occurrence of unevenness in the R degree of the cathode ray tube is reduced, which has the effect of improving productivity.

[Brief explanation of the drawing]

Figure 1 is an enlarged cross-section to explain the structure of the fluorescent surface of the panel, Figures 2 and 3 are conceptual diagrams to explain the filming process, and Figure 4 is a pie lens after the filming process has been completed. Fig. 5 is an explanatory diagram of the process of spraying orthoboric acid solution onto the filming film, Fig. 6 is an enlarged sectional view of a panel in which an aluminum film is deposited on the surface on which boric acid microcrystals are formed. It is. (1)...Panel, (1b)...Inner surface of panel, σ
0... Filming g, R... Solution of orthoboric acid, 04)... Spray gun, α'i)... Microcrystal of boron (to)... Aluminum group, OI... ·Pinhole. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] (1) A filming liquid is applied onto the phosphor layer formed on the inner surface of the panel of a color picture tube, and after drying to form a filming film of uniform thickness, an inorganic substance solution is sprayed. In the method for forming a filming film, the solution of the inorganic material is mixed with 0.5 to 4% by weight of orthoboric acid (H_3BO_3 ) and 10
A method for forming a filming film for a color cathode ray tube, characterized in that the composition comprises ~55% by weight of ethanol or methanol and the remaining amount of water. (2) The method for forming a filming film for a color cathode ray tube according to claim 1, wherein the temperature of the inner surface of the panel when spraying the orthoborate solution is 40 to 70°C.