KR100244950B1 - Composition and manufacturing method of a fluorescent slurry - Google Patents

Abstract

A phosphor slurry composition for producing a highly dispersed phosphor slurry composition without increasing the amount of a surfactant, and obtained by pre-coating a phosphor with polyvinyl acetate followed by pure water, polyvinyl alcohol, a surfactant, and ammonium dichromate.

Description

Phosphor Slurry Composition and Manufacturing Method Thereof

Figure 1a shows the state that the phosphor is dispersed in the phosphor slurry according to the prior art,

Figure 1b shows a state in which the phosphor is dispersed in the phosphor slurry according to the present invention.

2 shows the correlation between the amount of surfactant and the viscosity of the phosphor slurry composition.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phosphor slurry composition used for preparing cathode ray tube fluorescent surfaces of color television, and relates to a phosphor slurry composition having excellent dispersibility due to no aggregation between phosphor particles and a method for producing the same.

The phosphor pattern forming the fluorescent surface of the color cathode ray tube consists of an array of three phosphors that emit three colors of red, green, and blue, respectively, when the electron beam collides. Generally, a fluorescent substance is apply | coated to the inner surface of the panel of a cathode ray tube by the dust method or the slurry method, and a predetermined fluorescent substance pattern is formed.

The dust method is a method of forming a phosphor pattern through a process of applying a special photosensitive resin composition in which the photosensitive part becomes sticky on a panel and exposing the light, then scattering the powdered phosphor and sucking and collecting the remainder thereon, The slurry method is a method of filling a phosphor slurry into an etching site formed by a photolithography method so that a predetermined phosphor pattern is formed. Since the slurry method has advantages in that the process is easier and quality is easier to control than the former dust method, most This slurry method is applied.

The fluorescent substance slurry used for a slurry method can be obtained by mix | blending predetermined fluorescent substance powder with polyvinyl alcohol, ammonium dichromate, surfactant, and pure water in an appropriate ratio.

In the conventional phosphor slurry composition, the dispersibility is increased by controlling the amount of the surfactant and the polyvinyl alcohol. The surfactant has a limit in the amount increase due to the viscosity that increases as the amount of the additive is increased, and the polyvinyl alcohol is also used. There is a problem that it is difficult to manufacture a high-density fluorescent film due to the increase in viscosity with increasing amount. The correlation between the amount of surfactant and the viscosity of the phosphor slurry composition can be seen in FIG.

The present invention is to solve the problems of the prior art as described above, an object of the present invention is to prepare a highly dispersible phosphor slurry without increasing the viscosity by using only a suitable amount of the surfactant.

In order to achieve the above object, the present invention, 100 parts by weight of the phosphor to the solution obtained by adding 0.01 to 0.5 parts by weight of polyvinyl acetate to the organic solvent and stirred with respect to 100 parts by weight of the phosphor was stirred for 3 to 5 hours Next, the fluorescent substance slurry composition which consists of injecting and stirring an organic solvent, 200-250 weight part of pure waters, 5.0-11.5 weight part of polybiyl alcohols, 0.2-0.5 weight part of surfactants, and 0.1-1.0 weight part of ammonium dichromate to the obtained fluorescent substance. It provides a method of manufacturing.

The present invention is described in detail as follows.

In the present invention, the amount of polyvinylacetate coated on the phosphor is preferably within 0.01 to 0.5 parts by weight based on 100 parts by weight of the phosphor. When the amount of polyvinyl acetate added is less than 0.01 part by weight, the amount to be coated is small, and the steric hindrance effect is insignificant, and when it is more than 0.05 part by weight, the packing tends to be worse.

As the organic solvent used to dissolve the polyvinylacetate, alcohols such as methanol and ethanol are preferably used. The amount of the organic solvent used is preferably in the range of about 3 to 5 times the volume of the phosphor, and the stirring time for dissolving the polyvinyl acetate in the organic solvent is sufficient for about 1 to 2 hours.

Phosphor was added to a solution in which polyvinyl acetate was dissolved in an organic solvent, and the mixture was sufficiently stirred for 3 to 5 hours, and then the organic solvent was filtered off to obtain a phosphor coated with polyvinylacetate.

Pure water, polyvinyl alcohol, a surfactant, and ammonium dichromate (photosensitive agent) are sequentially added to the polyvinylacetate-coated phosphor thus obtained. At this time, when pure water is initially added, stirring should be started slowly and added with constant stirring to make uniform mixing.

Referring to the process of forming the phosphor pattern from the phosphor slurry thus prepared in relation to the stripe type, the coating of the undercoating solution → front exposure → green phosphor coating → green stripe exposure on a panel on which a black matrix is formed which distinguishes green, blue and red stripes. And developing → blue phosphor coating → blue stripe exposure and developing → red phosphor coating → red stripe exposure and developing → filming liquid coating → drying.

In the following, preferred embodiments of the present invention are described.

Example 1

1000 ml of methanol was put into a 2 L beaker, and 10 g of a vinyl acetate polymer (Japan Junsei Chemical, 50% resin) was added and stirred. After stirring for 1 hour, 300g of ZnCdS: Ag green phosphor was added thereto, followed by stirring for 3 hours. The mixture was then filtered under reduced pressure using a filter paper to obtain a polymer coated phosphor. The phosphor obtained by filtration was immediately transferred to another beaker without drying, and in order, 128 g of pure water, 106 g of 8% polyvinyl alcohol, 7.3 g of 5% surfactant and 4.8 g of 5% ammonium dichromate were added with gentle stirring and stirring continued for 8 hours. A green phosphor slurry composition was prepared.

Example 2

1000 ml of methanol was put into a 2 L beaker, and 15 g of vinyl acetate polymer (50% of resin powder, manufactured by Nippon Seishi Chemical Co., Ltd.) was added thereto and stirred. After stirring for 1 hour, 300g of ZnS: Ag blue phosphor was added thereto, followed by stirring for 3 hours. The mixture was then filtered under reduced pressure using a filter paper to obtain a polymer-coated phosphor. The phosphor obtained by filtration was immediately transferred to another beaker without drying, and in order, blue phosphor was added slowly and stably with 122 g of pure polyvinyl alcohol, 115 g of polyvinyl alcohol, 10.2 g of 5% surfactant, and 12.2 g of 5% ammonium dichromate, and continued stirring for 8 hours. A slurry composition was prepared.

Example 3

1000 ml of methanol was put in a 2 L beaker, and 20 g of vinyl acetate polymer (Japan Junsei Chemical Co., 50% resin) was added thereto and stirred. After stirring for 1 hour, 300 g of Y ₂ O ₂ S: Eu red phosphor was added thereto and stirred for 3 hours. The mixture was then filtered under reduced pressure using a filter paper to obtain a polymer-coated phosphor. The phosphor obtained by filtration was immediately transferred to another beaker without drying, and in order, 126 g of pure water, 115 g of 8% polyvinyl alcohol, 11.2 g of 5% surfactant, and 15.2 g of 5% ammonium dichromate were added with gentle stirring and stirring continued for 8 hours. A red phosphor slurry composition was prepared.

Using the green, blue and red phosphor slurry composition prepared in Examples 1 to 3, the fluorescent surface was prepared by the following method.

[Fluorescent surface manufacturing process]

On a panel inner surface of the CRT, a predetermined amount of a photocurable resin exhibiting photoadhesion by ultraviolet rays or the like was applied and dried, followed by exposure to form a photoadhesive film. Here, the green fluorescent substance slurry composition obtained in Example 1 was apply | coated and dried, and exposure using the high pressure mercury lamp was performed. After the exposure was completed, washing was performed with warm water to obtain a fluorescent surface on a stripe or dot having a predetermined shape. Subsequently, the above-described process was performed sequentially using the blue phosphor slurry composition and the red phosphor slurry composition obtained in Examples 1 and 2 to prepare a fluorescent surface.

The phosphor slurry composition prepared according to the present invention is excellent in dispersibility because phosphor aggregation is prevented due to steric hindrance dispersion effect by polyvinylacetate in addition to dispersion effect by electrostatic repulsive force by surfactant.

In addition, according to the present invention, since the amount of the surfactant can be reduced, the amount of Na salt or the like which has a detrimental effect on the life of the CRT can be reduced.

Claims (3)

100 parts by weight of phosphor was added to the solution obtained by adding 0.01 to 0.05 parts by weight of polyvinyl acetate to the organic solvent and stirred for 3 to 5 hours, followed by filtration and removal of the organic solvent. A method for producing a phosphor slurry composition comprising 200 to 250 parts by weight, polyvinyl alcohol 5.0 to 11.5 parts by weight, 0.2 to 0.5 parts by weight of surfactant, and 0.1 to 1.0 part by weight of dichromic acid. The method of claim 1, wherein the organic solvent is methanol or ethanol. Phosphor slurry composition prepared by the method of claim 1.