KR19980060817A - Cathode ray tube bulb and its manufacturing method - Google Patents

Abstract

The present invention discloses a cathode ray tube bulb and a method of manufacturing the same. The method of manufacturing a cathode ray tube bulb may include sequentially forming a conductive layer and a photoconductive layer on an inner surface of a screen, and then charging the photoconductive layer; Fixing a shadow mask to an inner surface of the panel, exposing the photoconductive layer, and then neutralizing the charge of the exposed portion; And sequentially attaching red, blue, and green light emitting phosphors coated with a cyclization rubber layer on an outer surface of the photoconductive layer by using electrostatic attraction. According to the present invention, the packing ratio of the film is improved to obtain a high quality fluorescent film. Cathode ray tube bulbs employing such fluorescent films are excellent in clarity and luminance characteristics.

Description

Cathode ray tube bulb and its manufacturing method

The present invention relates to a cathode ray tube bulb and a method of manufacturing the same. More specifically, a dry electrophotographic method in which a triboelectric is made on a phosphor using a principle of a copier, and sprayed onto a panel in a discharge state is applied. The present invention relates to a cathode ray tube bulb having improved clarity and brightness, and a method of manufacturing the same.

In general, the cathode ray tube bulb 1 is formed on the inner surface of the panel 2, the screen surface 2a having a screen surface 2a for reproducing an image upon reproduction of the screen as a transparent window, as shown in FIG. The fluorescent film 3 of the predetermined pattern, the shadow mask frame assembly 6 installed inside the panel 2, and the panel 2 are sealed to form an outer container of the cathode ray tube, and the electron gun (7) on the neck portion 7a. 5) is provided with the enclosed funnel 7 and the deflection yoke 8 provided in the cone part 7b of this funnel 7.

Among these, in the fluorescent film 3 formed in the color cathode ray tube, red, green, and blue phosphors are formed in the form of dots or stripes between black matrices, and a general manufacturing method of such a fluorescent film is as follows.

First, a slurry containing red phosphor, polyvinyl alcohol as a main component, and potassium dichromate is prepared as a main component, and applied to an inner surface of a panel on which a black matrix is formed, followed by drying, exposure, development, and the like. Go through the process. Subsequently, the remaining two phosphor components are formed on the panel in the same manner to form a phosphor film.

However, according to the above method, there are the following problems.

First, since the state of the fluorescent film obtained varies greatly depending on factors such as viscosity, dispersibility, drying temperature, time, pressure used during development, exposure sensitivity, and the like in the manufacturing process, process control must be strictly controlled.

Second, after applying the phosphor slurry, even after the exposure and development process, the phosphor remains in the unexposed portion, there is a problem that is mixed with the phosphor to be applied later.

Third, a colored material may be produced by the reaction of the hydroxyl group of polyvinyl alcohol contained in the phosphor slurry with ammonium dichromate salt. In this case, since the color emitted by each dot or stripe is far from pure red, green, or blue, there is a problem that the color purity is lowered.

Fourth, when the method of directly applying the phosphor slurry to the panel, the production line is long, takes a long time, and there is a problem of environmental pollution by ammonium dichromate used as a photosensitive agent.

In order to solve this problem, a method of forming a fluorescent film using an electrophotographic method has been proposed as a method of forming a fluorescent film having excellent clarity and brightness characteristics through a simple process compared to the conventional slurry method.

The electrophotographic method uses the photoconductive phenomenon of the electrophotographic process, which will be described in more detail. First, a photoconductive layer is formed on the inner surface of the screen, the photoconductive layer is charged using a corona charger, and the shadow mask is fixed. It exposes. Subsequently, after neutralizing the charge of the exposed portion, the process of repeatedly attaching one of the red, green, and blue phosphors on the photoconductive layer to the unexposed portion by using electrostatic attraction is performed to form a fluorescent film.

However, in the conventional method of manufacturing a fluorescent film according to the electrophotographic method, the adhesion strength of the phosphor to the photoconductive layer is not so large that the phosphor is separated from the photoconductive layer by an external force such as an external impact or pressure, thereby Contamination of dots and clogging of shadow masks were frequent.

In order to solve the above problems, the present inventors have completed the present invention regarding a method of coating a highly charged polymer on the outer surface of a phosphor and spraying the phosphor directly on a panel in a discharged state. .

An object of the present invention is to provide a method for producing a cathode ray tube bulb having a fluorescent film having improved clarity and brightness by coating a polymer having a strong charge on the outer surface of the phosphor to improve the packing ratio of the film.

Another technical problem to be achieved by the present invention is to provide a cathode ray tube bulb which is manufactured according to the above method.

1 is a cross-sectional view of a bulb for a typical cathode ray tube.

Explanation of symbols for the main parts of the drawings

1 ... bulb for cathode ray tube 2 ... panel

2a ... screen surface 3. fluorescent film

5. Electron gun 6. Shadow mask frame assembly

7 ... Funnel 7a. Funnel neck

7b ... funnel cone part 8 ... deflection yoke

The first object of the present invention is to (a) sequentially forming a conductive layer and a photoconductive layer on the inner surface of the screen, and then charging the photoconductive layer; (b) fixing the shadow mask on the inner surface of the panel, exposing the photoconductive layer, and then neutralizing the charge of the exposed portion; And (c) sequentially attaching red, blue, and green light emitting phosphors coated with a cyclized rubber layer on an outer surface of the photoconductive layer by using electrostatic attraction. It is done by

In the step (c), the luminescent phosphor coated with a cyclized rubber layer on the outer surface is prepared using a composition comprising cyclized rubber, a solvent and a phosphor.

A second object of the present invention is made by a cathode ray tube bulb, characterized in that manufactured according to the above method.

The present invention relates to a method for producing a fluorescent film according to a dry electrophotographic method in which a triboelectric material is formed on a phosphor coated with a triboelectric generating material and sprayed onto the cathode ray tube panel in a discharged state.

As a material capable of generating the triboelectricity, various polymers may be used, but polymers having excellent solubility and adhesion to organic solvents are used. As a substance having such a property, cyclized rubber is preferable.

Here, the cyclized rubber is prepared by reacting natural rubber or synthetic rubber with a substance such as heavy metal chloride in addition to sulfuric acid and paratoluene sulfonyl chloride. This material is a thermoplastic rubber derivative having a lower fluorine degree than the original rubber and containing a cyclized structure in the molecule, and has a very excellent adhesive force.

Hereinafter, a method of manufacturing the phosphor used in the present invention will be described.

The phosphor composition used in the present invention contains a binder, a solvent and a phosphor.

As the binder, cyclized rubber is used as described above, and the content of the cyclized rubber is preferably 1 to 40% by weight, particularly 1 to 10% by weight in the total composition. If the content of the cyclized rubber exceeds 40% by weight, agglomeration occurs, and if the content of the cyclized rubber is less than 1% by weight, it is not preferable because phosphor charging becomes difficult.

As the solvent, an isoparaffinic hydrocarbon compound is used, and most preferable ones thereof are isoparg (Isopar G: Exxon) and Soltron 100 (Soltron 100: Philipspartium). At this time, the content of the solvent is 40 to 70% by weight, preferably 40 to 50% by weight. Within this range, the dispersibility of the phosphor and the binder is excellent.

The content of the phosphor is preferably 10 to 50% by weight, particularly 30 to 50% by weight of the total composition.

The binder and the solvent having the composition as described above are preferentially mixed sufficiently. Thereafter, a phosphor is added thereto, and the reaction mixture is sufficiently stirred to have a uniform composition.

The reaction mixture is then heated to 80-150 ° C. and stirred for 4-6 hours.

The resulting precipitate is filtered and dried to prepare phosphor coated with cyclized rubber.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the following Examples.

Example 1

5 g of Alpex CK-450 (ALPEX CK-450: Hoechst) and 200 g of Isopar G (ISOPAR G: Esso Chemicals) were mixed and stirred for about 1 hour.

150 g of phosphor particles were added to the reaction mixture, followed by stirring for about 2 hours to completely disperse the phosphor in isopar G.

The fully dispersed solution was stirred at about 80 ° C. for about 3 hours, and the resulting precipitate was filtered and dried to prepare phosphor coated rubber.

Example 2

The inner surface of the panel was cleaned and then a conductive layer was applied. The photoconductive composition comprising 15 g of poly-2-pyridinemethyl methacrylate, 10 g of 3,5-dinitrobenzonitrile, 100 g of polymethyl methacrylate, 100 g of silicone sila 100, and 700 g of toluene was applied to the conductive layer. A photoconductive film having a thickness of 4 μm was formed.

The photoconductive layer was charged using a corona charger.

A predetermined portion of the photoconductive layer was exposed using a shadow mask. After neutralizing the charge of the exposed portion, the phosphor prepared according to Example 1 was attached to the unexposed portion. The fluorescent film was semi-fixed using acetone and completely fused using an infrared heater to form a fluorescent film.

The clarity and screen brightness of the cathode ray tube employing the fluorescent film produced according to the above method was measured.

As a result, it can be seen that the cathode ray tube employing the fluorescent film manufactured according to the above embodiment improves the brightness and clarity of the screen compared with the cathode ray tube employing the fluorescent film formed according to a conventional method.

According to the present invention, the packing ratio of the film is improved to obtain a high quality fluorescent film. Cathode ray tube bulbs employing such fluorescent films are excellent in clarity and luminance characteristics.

Claims (6)

(a) sequentially forming a conductive layer and a photoconductive layer on the inner surface of the screen, and then charging the photoconductive layer; (b) fixing the shadow mask on the inner surface of the panel, exposing the photoconductive layer, and then neutralizing the charge of the exposed portion; And and (c) attaching red, blue, and green light emitting phosphors having a cyclized rubber layer coated on an outer surface thereof to the upper portion of the photoconductive layer using electrostatic attraction. The method according to claim 1, wherein in the step (c), the phosphor having a cyclized rubber layer coated on its outer surface is manufactured using a composition comprising cyclized rubber, a solvent, and a phosphor. The method according to claim 2, wherein the content of the cyclized rubber is a cathode ray tube bulb, characterized in that 1 to 40% by weight in the total composition. The method of claim 2, wherein the content of the phosphor is 10 to 50% by weight in the total composition. The method of claim 2, wherein the content of the solvent is 40 to 70% by weight in the total composition. Cathode ray tube bulb prepared according to any one of claims 1 to 5.