KR100288720B1 - Method of preparing phosphor for dry electrophotographical screen of crt coated with silica and titanate system coupling, method for manufacturing screen using the phosphor and crt manufactured by the method - Google Patents

Abstract

PURPOSE: A method of preparing phosphor for a dry electrophotographical screen of a CRT coated with silica and titanate system coupling, a method for manufacturing a screen using the phosphor and a CRT manufactured by the method are provided to enhance the movability and chargeability of phosphor powder. CONSTITUTION: First, silica is coated and silica is distributed in methanol. Then, phosphor powders are gradually added to the methanol. Next, methanol is again distributed in the methanol having the phosphor powder added. Then, the resultant is filtered. Next, the resultant is dried. Then, silica coating powder is prepared by filtering the dried resultant. In addition, the phosphor powder coated with silica is again coated with titanate system coupling.

Description

Phosphor preparation method for producing dry electrophotographic fluorescent surface on panel inner surface of double coated cathode ray tube with silica and titanate-based coupling, fluorescent surface manufacturing method using same and cathode ray tube manufactured by the same

The present invention relates to a method for producing a phosphor for dry electrophotographic fluorescent surface production on a panel inner surface of a cathode ray tube double coated with silica and titanate-based coupling, a method for producing a fluorescent surface using the same, and a cathode ray tube manufactured thereby. Or a method for manufacturing a phosphor for dry electrophotographic fluorescent surface production on the inner surface of a panel of a double-coated cathode ray tube coated with silica and titanate-based couplings having improved charging and flow characteristics by a corona discharge device, and a method for manufacturing the fluorescent surface using the same To a drawn cathode ray tube.

In general, as shown in FIG. 1, a cathode ray tube includes a vacuum bulb divided into a panel 12, a funnel 13, and a neck 14, and an inside of the neck 14. And an shadow gun 16 mounted on the sidewall of the panel 12.

The inner surface of the panel face plate 18 of the panel 12 is formed with a fluorescent surface 20, the electron beams (19a, 19b) emitted from the electron gun 11 is focused and accelerated by various lens systems, the anode button ( It is greatly accelerated by the high voltage applied through 15) and deflected by the deflection yoke 17 and passed through the apertures or slits 16a of the shadow mask 16 to the fluorescent surface 20.

In addition, the fluorescent surface 20 is formed on the rear surface of the panel face plate 18, and in the case of a color, as shown in FIG. 2, a plurality of stripe or dot shaped phosphors R, G and B and a light absorbing material 21 such as a black coating are formed between the phosphors R, G and B. In addition, the rear surface of the aluminum thin film layer 22 is formed as a conductive film layer to increase the luminance of the fluorescent screen 20, to prevent ion damage of the fluorescent screen 20, the potential drop prevention of the fluorescent screen 20 and the like. Although not shown, a resin such as lacquer is applied between the fluorescent surface 20 and the conductive film layer, which is the aluminum thin film layer 22, in order to increase the plan view and the reflectance of the aluminum thin film layer 22.

The conventional photolithographic wet process in which the fluorescent surface 20 is formed by applying and drying a suspension containing fluorescent particles such as a chrominescent phosphorus component or a suspension containing a light absorbing material 21 and drying In addition, it does not meet the requirements of high-definition, the manufacturing process and the manufacturing equipment is complicated, the manufacturing cost is large, and also has a number of problems, such as the consumption of large quantities of clean water, wastewater generation, phosphorus emissions, hexavalent chromium photoresist emissions. Recently, an electrophotographic fluorescent surface manufacturing method has been developed that improves the wet photolithography. In this electrophotographic manufacturing method, wet methods still have the above-mentioned problems. It was considerably resolved.

As an example, it will be described with reference to the "method of manufacturing a fluorescent surface of the cathode ray tube" filed by the present applicant.

3 (a) to (e) schematically show each process according to the above manufacturing method. 3A illustrates a coating process in which a conductive film 132 and a photoconductive film 134 are formed on an inner surface of the panel face plate 18. The conductive film 132 is a polyelectrolyte, for example, a conventional solution of 1-50% by weight of Catfloc-c manufactured by Calgon and 1-50% by weight of 10% PVA solution (water remaining). It is formed by applying and drying in the method of. A new photoconductive coating solution containing a substance reacting with ultraviolet rays is applied thereon and dried. UV-sensitive materials include at least one of bis dimethyl phenyl diphenyl butatriene, trinitrofluorenone (TNF) and ethyl anthraquinone (EAQ). As a photocoating solution, 0.01 to 10% by weight of bis dimethyl phenyl diphenyl butytriene and 1 to 30% by weight of polystyrene as a polymer binder are toluene or xylene remaining. It was used by dissolving in (xylene).

3B schematically illustrates the charging process. A DC voltage of + 1K volts or less, preferably +700 volts or more was applied to charge the corona discharge device 36. Since the photoconductive film 134 reacts with ultraviolet rays having a wavelength of at least 450 nm or less, darkroom work is unnecessary.

3C schematically shows an exposure process, in which ultraviolet light having a short wavelength and straightness from the ultraviolet light source 138 passes through the ultraviolet lens 140 and enters the shadow mask 16 at a desired angle of incidence. The photoconductive film 134 is exposed in a desired arrangement through the aperture or slits 16a of the shadow mask 16 having the arrangement. At this time, the conductive film 132 is earthed, and the charge of the exposed portion is discharged through the conductive film 132. The charge in the non-exposed portion remains in the photoconductive film 134 as it is. Since this exposure process uses the ultraviolet light source 138, it is not necessary to work in a dark room.

3D schematically shows a developing process. Conventionally, in this development step, the carrier beads and the phosphor particles or the light absorbing material particles are mixed to charge static electricity by friction, but according to the present invention, fine powders such as phosphor powder or powder of the light absorbing material are applied by air pressure. The fine powder is charged by spraying the hopper 148 through the venturi tube 146 through the discharge electrode 144a such as the corona discharge device 36 and the nozzle 144b to charge the fine powder, and to expose the exposed portion of the photoconductive film 134. It is attached to either of the non-exposed parts. The polarity of the static electricity charged by the fine electrode by the discharge electrode 144a is determined by whether the fine powder is attached to the exposed portion or the non-exposed portion in the exposure process. In other words, the fine powder is charged to -charge when attached to the non-exposed portion that is positively charged, and the fine powder is charged to + charge when attached to the exposed portion where the charge is released. In addition, the charged fine powder injected into the developing container 142 is strongly attached to the surface of the photoconductive film 134 in a desired arrangement by the action of electrical attraction and repulsive force.

Figure 3e schematically illustrates a fixing process according to the applicant's invention using vapor swelling method. In this step, at least the photoconductive film 134 is squeezed by subjecting the solvent vapor, such as acetone and methyl isobutyl ketone, to the surface of the photoconductive film 134 to which the desired fine powder (s) are attached in a desired arrangement in the developing step. The polymer contained therein is dissolved, and the fine powder (s) attached by the action of electric force are fixed by the adhesion of the dissolved polymer. The above-described "method of manufacturing a fluorescent surface of a cathode ray tube" described by the present applicant has been described. In the process, the phosphor powder from the hopper 148 is interposed through a venturi tube 146 as in the developing process of FIG. 3D. When injected to 144b), a polymethyl methacrylate primary film and a polyacrylamide secondary film are formed on the phosphor particles to charge the phosphor powder by the discharge electrode 144a. However, these two coats are cumbersome and are not uniformly and sufficiently charged even by the polymethyl methacrylate primary film and the polyacrylamide secondary film, and further, by friction without using the discharge electrode 144a. Even when charging, there is a problem such as requiring a carrier bead for generating triboelectricity in addition to coating on phosphor particles as in the developing process in US Pat. No. 4,921,767. In addition, simply forming a primary film of polymethyl methacrylate (PMMA) and a secondary film of poly acrylamide (PAA) in order to impart charging characteristics to the phosphor powder does not have sufficient flow. There is a problem of sticking to a container or the like.

Accordingly, the present invention provides a dry electron on the inner surface of a panel of a cathode ray tube double coated with silica and titanate-based coupling to improve the flow characteristics and charging characteristics of the phosphor powder particles to solve the above problems. It is an object of the present invention to provide a method for producing a phosphor for producing a photo-luminescent surface, a method for producing a fluorescent surface using the same, and a cathode ray tube manufactured thereby.

1 is a schematic cross-sectional view partially showing a colored cathode ray tube;

FIG. 2 is a partially enlarged cross-sectional view illustrating a fluorescent surface configuration of the cathode ray tube of FIG. 1;

3 (a) to (e) is an explanatory view schematically showing a dry electrophotographic fluorescent surface manufacturing process for producing a fluorescent surface of a cathode ray tube using the phosphor of the present invention,

Figure 4 (a) is an enlarged view of the phosphor particles according to an embodiment of the present invention for producing a fluorescent surface, (b) is an enlarged view of the phosphor particles according to an embodiment of the present invention constituting the fluorescent surface.

Explanation of symbols on the main parts of the drawings

10 cathode ray tube (CRT) 11 electron gun

12: panel 13: funnel

14 neck 15 anode button

16: shadow mask 17: deflection yoke

18: panel face plate 19a, 19b: electron beam

20: fluorescent surface 21: light absorbing material

22: aluminum thin film layer 36: corona discharge device

132: conductive film 134: photoconductive film

138: ultraviolet light source (lamp) 140: ultraviolet lens

142: developing container 144a: discharge electrode

144b: Nozzle 146: Venturi tube

148: Hopper C1: Silica Coating

C2: titanate-based coupling P: phosphor particles

In order to achieve the above object, the present invention provides a method for producing a double-coated phosphor of silica powder and silicate titanate-based coupling in the form of dry powder to improve the flow characteristics and charging characteristics of the phosphor particles used in the production of the fluorescent surface of the inner surface of the cathode ray tube panel In the silica coating step: the first dispersion step of dispersing silica in methanol; An addition step of slowly adding the phosphor powder to methanol in which the silica is dispersed; A second dispersion step of dispersing the methanol again in methanol to which the silica is dispersed and the phosphor powder is added; A filtering step of filtering the result of the second dispersion step; A drying step of drying the filtered result in the filtering step; And a sieve step of preparing a silica-coated phosphor powder by sieving the resultant dried in the drying step, wherein the titanate-based coupling is coated on the silica-coated phosphor powder: titanate in an organic solvent such as N-hexane. A first dispersion step of dispersing the system coupling; An addition step of slowly adding the silica coated phosphor powder to the methanol in which the titanate-based coupling is dispersed; A second dispersion step of dispersing the organic solvent such as N-hexane again in the methanol in which the titanate-based coupling is dispersed and the phosphor powder is added; A filtering step of filtering the result of the second dispersion step; A drying step of drying the filtered result in the filtering step; And a sieve sifting the resultant dried in the drying step to obtain a phosphor powder of the double coating of silica and titanate-based couplings provides a phosphor manufacturing method for producing a dry electrophotographic fluorescent surface of the cathode ray tube.

The dispersion steps are steps that are dispersed by ultrasonic waves, and the filtering step is a step of filtering by a glass frit filter, and the drying step is a step of drying at about 100 ° C. or less for about 3 to 5 hours.

In addition, the present invention is to form a volatile photoconductive film on the volatile conductive film coated on the inner surface of the panel, and to charge the photoelectric film with a uniform electrostatic charge, and then selectively expose the photoconductive film through a shadow mask through a light source. The exposed portion is developed with a discharge electrode or a first charged phosphor by friction, and the above-mentioned charging step, exposure step and developing step are repeated in a desired arrangement with respect to the second and third phosphors, respectively. In the method of manufacturing a dry electrophotographic fluorescent surface of a cathode ray tube comprising a fixing step of fixing the solvent vapor by splicing them, the particles of the first to third phosphors introduced in the developing step are dispersed and coated with silica and titanate-based coupling. It provides a dry electrophotographic fluorescent surface manufacturing method of the cathode ray tube characterized in that the.

The present invention also includes a vacuum bulb divided into a panel, a funnel and a neck, an electron gun mounted inside the neck, and a shadow mask mounted on a side wall of the panel, and a plurality of stripes on the inner surface of the panel face plate of the panel. In a cathode ray tube in which a fluorescent surface having a uniform arrangement of light-absorbing materials such as a dot-shaped phosphor and a black coating is formed, and an aluminum thin film layer formed as a conductive film layer is formed on the rear surface of the fluorescent surface, the fluorescent surface is silicon and titanium. It provides a cathode ray tube, characterized in that the fluorescent surface formed on the inner surface of the panel by dry electrophotographic using a phosphor, dispersed in the coating.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

4A shows particles of double coated phosphors of silica and titanate-based couplings, and FIG. 4B shows particles of phosphors in which volatiles are burned by baking and silicon and titanium remain.

First, one embodiment of a method for producing a silica coated phosphor is as follows.

1 g of silica is dispersed in 1 L of methanol. This dispersion step is preferably by ultrasonic dispersion.

Thereafter, 1 Kg of phosphor powder was slowly added to the silica in which silica was dispersed, and 0.5 L of methanol was further dispersed. Also in this case, it is dispersed by ultrasonic waves.

The resultant is then filtered with a glass frit filter, followed by drying at 60-80 ° C. for 2-3 hours followed by a sieving step. In this sieving step, a screen of about 400 mesh is sieved to obtain a phosphor in which the desired silica is dispersed and coated.

The silica-coated phosphor obtained in this way has excellent flow characteristics and is not easily adhered to each other or other materials, and thus has excellent workability in the above-described fluorescent surface manufacturing process. Due to its dispersion and coating, it is also excellent for removing volatiles.

Therefore, even in the baking process, the heating time and temperature can be shortened, whereby a more preferable phosphor array structure without disturbing the array boundary of the phosphor can be obtained.

As described above with reference to FIG. 4A, the titanate-based coupling (C2) is substituted for the PMMA secondary film (PM) and the PAA primary film (PA) in order to improve the charging characteristics due to the discharge electrode or the friction on the silica-coated phosphor particles (P). ) The coating is formed to be dispersed. The titanate-based coupling (C2) contains hydrophobic and hydrophilic groups, and examples thereof include the following structural formulas.

In the structural formula, the stearyl group (C ₁₇ H ₃₅ ) is a hydrophobic group, isopropoxy (isopropoxy) (C ₃ H ₇ ) is a hydrophilic group, the titanate-based coupling (C2) is the phosphor particles ( It is dispersed and coated in P) to bond with the metal sulfide or oxysulfide metal of the phosphor particles (P). That is, instead of the hydrophilic group (isopropoxy (C ₃ H ₇ )) in the above structure, it is bonded to SiO ₂ attached to the surface of the phosphor in place.

The phosphor particles (P) coated with the titanate-based coupling (C2) are easily charged to + by the hydrophobic group (stearyl group (C ₁₇ H ₃₅ )) as shown in FIG. 4A. However, when the titanate-based coupling (C2) is 1% by weight or more, the electrical conductivity is inferior.

An embodiment of the method of manufacturing the titanate-based coupling coating phosphor described above is as follows.

First, 10 g of titanate-based coupling is dispersed in 1 L of an organic solvent such as N-hexane. This dispersing step is preferably by ultrasonic dispersion, and the titanate-based couplings are trade names KR TTS, KR 46B, KR 55, KR 41B, KR 38S, KR 138S, KR238S, 338X, KR 12, KR44, KR 9SA, KR 34S, etc. are mentioned.

Thereafter, 1 Kg of the above-described silica coating (C1) phosphor powder was slowly added to an organic solvent such as N-hexane in which the titanate-based coupling was dispersed, and again, an organic solvent such as 0.5 L of N-hexane was dispersed. Also in this case, it is dispersed by ultrasonic waves.

The resultant is then filtered with a glass frit filter, followed by drying at 60-80 ° C. for 2-3 hours followed by a sieving step.

In this sieving step, the sieving of about 400 mesh (sieve) to obtain the phosphor particles (P) coated with the desired silica (C1) and titanate-based coupling (C2), as shown in Figure 4a.

The phosphor particles (P) obtained as described above were all excellent in charge characteristics with a resistance of 10 ¹⁴ Ωcm or more.

FIG. 4B is a double-coated phosphor particle of silica and titanate-based couplings of FIG. 4A added to the above-described fluorescent surface manufacturing process to form a fluorescent surface, and after forming the aluminum thin film layer 22 by a conventional method, baking Process, that is, phosphor particles P in which volatile substances such as the conductive film 132, the photoconductive film 134, and the hydrophobic group of the titanate-based coupling are removed. In this manner, silica (Si) and titanium (Ti) are dispersed and coated on the phosphor particles (P) constituting the fluorescent surface.

The phosphor obtained in this way has excellent flow and charging characteristics, and can be easily charged with a predetermined + charge by friction, discharge electrode, or phosphor particles, thereby shortening the developing time in the developing process. In addition, in the baking process, which is the final process of the fluorescent surface, silica and titanate-based couplings are dispersed and coated, which is excellent in removing volatile substances, and the film thickness of the manufactured fluorescent surface can be made uniform. There is.

While preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various changes and modifications may be made by those skilled in the art from the matters described in the claims.

Claims (4)

Fabrication of dry powder type silica and titanate-based coupling double coated phosphors to improve the flow and charging characteristics of phosphor particles used to manufacture the fluorescent surface 20 on the inner surface of the cathode ray tube panel 12 by dry electrophotographic In the method, the silica coating step comprises: a first dispersion step of dispersing silica in methanol; An addition step of slowly adding the phosphor powder to methanol in which the silica is dispersed; A second dispersion step of dispersing the methanol again in methanol to which the silica is dispersed and the phosphor powder is added; A filtering step of filtering the result of the second dispersion step; A drying step of drying the filtered result in the filtering step; And a sieve step of preparing a silica-coated phosphor powder by sieving the resultant dried in the drying step, wherein the titanate-based coupling is coated on the silica-coated phosphor powder: titanate in an organic solvent such as N-hexane. A first dispersion step of dispersing the system coupling; An addition step of slowly adding the silica coated phosphor powder to the methanol in which the titanate-based coupling is dispersed; A secondary dispersing step of dispersing the organic solvent such as N-hexane again in the methanol in which the titanate-based coupling is dispersed and the phosphor powder is added; A filtering step of filtering the result of the second dispersion step; A drying step of drying the filtered result in the filtering step; And a sieve step of sifting the resultant dried in the drying step to obtain a phosphor powder of a double coating of silica and titanate-based couplings, and dry electrons of the cathode ray tube double-coated with silica and titanate-based couplings. Method for producing phosphor for photographic fluorescent surface production. The method of claim 1; The dispersion steps are steps dispersed by ultrasonic waves; The filtering step is filtering by a glass frit filter; The drying step is a step of drying for about 3 to 5 hours at 100 ℃ or less, silica and titanate coupling method for producing a fluorescent electrophoretic fluorescent surface for producing a fluorescent electroluminescent surface on the inner surface of the panel of the double-coated cathode ray tube. After forming a volatile photoconductive film 134 on the volatile conductive film 132 coated on the inner surface of the panel 12, and charging the photoconductive film 134 with a uniform electrostatic charge, the photoconductive film 134 is a light source. Through the shadow mask 16 to selectively expose the exposed portions, and develop the exposed portions with the first phosphor charged by the discharge electrode or the friction, and the charging step in a desired arrangement for the second and third phosphors, respectively. In the method of manufacturing a dry electrophotographic fluorescent surface of a cathode ray tube comprising a fixing step of repeating the exposure step and the developing step, and then fixing the phosphors by solvent vapor, the first to third phosphors introduced in the developing step A method for producing a dry electrophotographic fluorescent surface on an inner surface of a panel of a cathode ray tube, wherein the particles are dispersed and coated with silica and titanate-based coupling. A vacuum bulb divided into a panel 12, a funnel 13 and a neck 14, an electron gun 11 mounted inside the neck 14, and a shadow mask 16 mounted on the side wall of the panel 12. The inner surface of the panel face plate 18 of the panel 12 has a constant array structure of a plurality of stripe or dot-shaped phosphors (R, G, B) and light absorbing material (21) such as black coating. In a cathode ray tube in which a fluorescent surface 20 is formed and an aluminum thin film layer 22 formed as a conductive film layer is formed on the rear surface of the fluorescent surface 20, the fluorescent surface 20 is a phosphor in which silicon and titanium are dispersed and coated on a particle surface. Cathode ray tube, characterized in that the fluorescent surface 20 formed on the inner surface of the panel by dry electrophotographic using.