JPS58192243A - Manufacture of metal backing cathode-ray tube - Google Patents

Abstract

PURPOSE:To fully wet the inside of a phosphor layer while degrading interface tension of water by adding a water-soluble macro molecule showing interface activity. CONSTITUTION:The inside of glass 6 of a cathode-ray tube face part is applied with phosphor powder in order to form a phosphor layer 7. A water solution of 1.0wt% of hydroxy-propyl cellulose is injected into said phosphor layer 7 in order to form a uniform water solution layer 8 by removing the surplus water solution. Next, a toluene solution of 3.5wt% of an acryl resin is sprayed in an atomized form on the water solution layer 8 followed by drying and forming a thin film of the acryl resin on the inside of the phosphor layer 7 by evaporating moisture and a solvent in order to obtain a metal backing layer 10 by evaporating alminium thereon. Thereafter, hydroxy-propyl cellulose and the acryl resin are decomposed and removed by heating. The phosphor layer 7 can be fully wetted because the interface tension of the water solution of hydroxy-propyl cellulose is low compared with that of water.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a cathode thin tube having a metal back layer using a metal such as aluminum on the inner surface of a phosphor layer.

When forming a metal layer by vapor depositing a metal such as aluminum on the fluorescent surface of a cathode ray tube, it is necessary to create a smooth metal back layer, that is, a metal back layer that does not have uneven spots when observed from the front of the face glass. In order to obtain
Conventionally, proper pretreatment has been performed to eliminate unevenness on the inner surface of the coated phosphor layer. For example, as shown in Fig. 1, the phosphor layer 2 coated on the inner surface of the face glass 1 of a Km polar ray tube is wetted with water 3 to fill in the unevenness and make the inner surface of the phosphor layer 2 appear smooth. After spraying a liquid M containing an organic polymer substance dissolved in a solvent onto the surface, drying and evaporating the water and solvent, the organic polymer thin film 4 is coated on the inner surface of the phosphor layer 2. A smooth metal back layer 5 is obtained by depositing a metal such as aluminum thereon.

Incidentally, the four portions 4 of the organic polymer material are to be heated and descaled in the next step.

However, since the surface of the phosphor is water repellent, the phosphor 1
-2 was not sufficiently wetted with water, and the unevenness on the inner surface of the phosphor layer could not be completely filled with water, and the metal back layer 5 was also not smooth. For this reason, the effect of metal back l- cannot be fully demonstrated, and ls#LIII
This reduced the commercial value of the pipe.

SUMMARY OF THE INVENTION The present invention provides a method for forming a 111-dimensional organic polymer thin film on a phosphor layer.

To prevent this, in the present invention, a water-soluble polymer exhibiting surface activity is added in order to reduce the interfacial tension of water in order to thoroughly wet the inner surface of the phosphor.

After studying various water-soluble polymers, we found that cellulose derivatives (methylcellulose, hydroxyglobil cellulose, hydroxyglobil methylcellulose, carboxymethylcellulose) and alginic acid derivatives (alginate propylene glycol ester, alginate soda Ethanolamine, ammonium alginate) and polyethylene glycol were found to be suitable.

A part of the interfacial tension measurement results are shown in FIG. 2, and it can be seen that the interfacial tension of the aqueous solution of the cellulose derivative decreases. Figure 2 is a graph showing the relationship between aqueous solution and interfacial tension at 200°C, where a is hydroxypropyl cellulose, b is polyvinyl alcohol, C is isobutylene-maleic acid coelectrode, and d is the property of water. .

The fK of these water-soluble polymers will now be described. The upper limit should be 0005 wt% or more in order to exhibit the effect of reducing interfacial tension. On the other hand, for the limit, the viscosity of the water bath liquid is 5
It is defined that the coating is tolerant when it is below 0cpa (20C). Although it depends on the polymerization degree of each polymer, 7 wt% corresponds to the upper limit of 1 degree for low polymerization degree substances. Although the object of the present invention can be achieved within this a degree range, the range of 0.1 to 2.0 wt % is easiest to manufacture.

As mentioned in -x and h, the viscosity of the water bath liquid is a very important factor in production. Even if the aqueous solution polymer specified in the present invention is added to the bathing polymer water bathing liquid that controls the angle of 45 degrees, the wetting of the bathing liquid to the phosphor J-2 is improved.

Examples of the present invention will be described below. As shown in FIG. 3, a phosphor powder is applied to the inner surface of the face glass 6 of the positive and negative ray tube to form a phosphor 1-7.

Hydroxypropyl cellulose (product name manufactured by Nippon Hakudatsusha [Japan*'HPCJ L brand]) is added to this phosphor 1497.
Add 1.0 wt% of water f4I& and remove excess water to form a uniform aqueous fL layer 8. Next, a toluene solution of 3.5 wt 4 of acrylic resin is sprayed onto the aqueous solution -8, and then dried, water and solvent are evaporated, and the acrylic resin 4 and 9 are coated on the inner surface -F of the phosphor layer 7. A metal back M10 was obtained by vapor-depositing aluminum thereon. After this heating, hydroxypropylcellulose? 'The krill tree was decomposed and removed. Since the aqueous solution of hydroxypropyl cellulose used in this example has a lower interfacial tension than water, it can sufficiently wet the phosphor j-T.

Next, the composition of the water bath solution used in other experiments will be discussed.

Example 2: 0 of alginate propylene glycol ester (manufactured by Kimitsu Chemical Industry Co., Ltd., trade name "Kimiroid" brand MV)
．． 1wt% water bath solution.

Example 3: Polyethylene oxide (manufactured by Kimitsu Chemical Industry Co., Ltd.,
@Product name rPEOj brand 1) 0.2wt% water bath solution.

Example 4: yt! ’) Vinyl alcohol (manufactured by Kuraray Co., Ltd.)

A water bath liquid containing 0.4 wt % of product name 1゛Cura V Poval 217) and hydroquinepropyl cellulose (Nihon Josokusha u, H41 product name [8 buds HPCJ brand L) (1.02 wt%).

By such a method, it is possible to form a metal bank 1- which has a sufficient effect on the phosphor layer made of water-repellent phosphor particles.

[Brief explanation of drawings]

Figure 41 shows the @plane L of a part of the face of a warm electrode tube to explain the conventional method of forming a metal bank on a fluorescent surface.
・A], LA2 diagram is a diagram showing the relationship between 1 degree and V#1 tension of a polymer aqueous solution, and Figure 3 is a diagram showing the difficulties in explaining the method of forming a metal bank on a fluorescent surface according to the present invention☆ ηF (m diagram) of a part of the face part of
1st, 8 ・ ・ ・ - Water M solution 1-19 ・ ・
・ ・ 4 smell, 10...Metal back + 4゜ agent 1) Rishin.

Claims (1)

[Claims] A phosphor is coated on the inner surface of the face of the cathode ray tube, and the inner surface of the phosphor layer is wetted with an aqueous solution containing a cellulose derivative, an alginic acid derivative, or polyethylene oxide as a solute component, and then a thin film of an organic polymer substance is coated with this aqueous solution. A method for manufacturing a metal back cathode ray tube, comprising: forming a metal back layer on the thin film, and then firing the metal back layer.