JPS58192246A - Manufacture of picture tube - Google Patents

Abstract

PURPOSE:To obtain a flat metal backing layer having no generated stripes and patches by filling unevenness on the surface of a phosphor layer with a water- soluble organic water solution having a pyrrolidone base as pretreatment. CONSTITUTION:Firstly, a green luminous phosphor Cas : Ce is applied to inside face of a face plate 1 of a picture tube in a water glass water solution by a settling application method, then the phosphor layer 2 is wetted with, for instance, 0.2wt% of a polyvinylpyrrolidine water solution 3 as a water-soluble organic substance containing pyrrolidone base, further a toluene solution of an acryl resin is applied by spraying while being dried thus to form a thin film 4 of an organic high-molecular substance. Thereafter, an aluminium metal backing layer 5 is formed on said thin film by vacuum evaporation to be treated by firing. In the picture tube thus obtained, the extremely good metal backing layer 5 having no generated stripes and patches all over inside of the face plate can be obtained while improving brightness by 5-10% as compared with the former one.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a picture tube, and more particularly to a method for forming a filming layer as a base for a metal back layer formed on the upper surface of a phosphor layer.

Normally, when a metal back layer is formed by vapor-depositing a metal such as aluminum on the fluorescent surface of a picture tube, when observing from a smooth metal back layer close to the - direction, that is, from within Nm of the face plate, the editing Alternatively, in order to obtain a metal back layer that does not have uneven spots, a suitable eruption treatment has conventionally been carried out to fill in the irregularities on the surface of the coated phosphor layer and smooth it. That is, as shown in the figure, in the manufacturing process of the receiving tube, the phosphor layer 2 coated on the inner surface of the face plate 1 is melted in a polyvinyl alcohol diluted water bath 3.
The surface of the phosphor layer 2 was propped up to make it smooth, and then a spray of liquid containing an organic polymer was sprayed onto the top surface for drying. Then, the supply agent and moisture are released A, and the organic polymer material ′j [spatter 4 is the phosphor]-2 is formed on the top surface of the organic polymer ′j [sprinkle powder 4 is the phosphor]-2. Then, a metal such as aluminum is vapor-deposited on the top surface to form a smooth metal back. I got layer 5.

However, according to the method for forming a fluorescent surface described above, the polyvinyl alcohol in the polyvinyl alcohol dilute water bath solution 3 spray-coated onto the phosphor layer 2 condenses unevenly during drying and grows on the upper surface. Cracks or pinholes were generated in the applied Ichiki Sho Molecular Materials thin film 4. The partial occurrence of these cracks or pinholes causes stripes or uneven spots on the metal back layer 5 formed on the upper surface, thus forming a smooth metal back layer 5 over the entire inner surface of the face plate 1. It has become clear from the results of experimental research by the inventors that this has become extremely difficult and the product value has been significantly reduced.

Therefore, the present invention has been made in view of the above-mentioned situation, and an object thereof is to provide a method for manufacturing a picture tube in which a smooth metal back layer can be obtained over the entire inner surface of the face plate of the picture tube. be.

In order to achieve such an object, the present invention provides a phosphor 11
In forming a thin film of an organic polymer substance on the phosphor layer, the surface irregularities of the phosphor layer are filled with a 0.01 to 2Xt% aqueous solution of a water-soluble organic substance having a pyrrolidone group as a pretreatment. According to this method, the phosphor itself or an inorganic substance attached to the phosphor surface, such as Z
r? ”, Cj”, so! −.

In contrast to pyrrolidone group-containing water-based organic substances, which are chemically extremely stable, good results were obtained.

Examples of the present invention will be described in detail below.

First, Uke 1.1! Green-emitting phosphor C was applied to the inner surface of the face plate of f by a precipitation coating method in a water glass bath solution.
After overlaying aS:Ce, the phosphor layer is wetted with a water-soluble organic substance containing a pyrrolidone group, such as a polyvinylpyrrolidone water bath solution of 02 densities, and then an acrylic resin toluene densities is applied by spraying and dried. and formed a thin film of organic-molecular material. Thereafter, an aluminum metal back was formed on this III film by an empty evaporation method, and a firing process was performed.

The picture tube obtained in this way has an extremely good metal back I- with no stripes or uneven spots over the entire inner surface of the face plate, and has higher brightness than picture tubes manufactured using conventional methods. It was possible to improve it by 5 to 10%.

In addition, the concentration of polyvinylpyrrolidone aqueous solution is 0.01
If it is less than 2.0% by weight, a metal back layer with a smooth trowel surface cannot be formed, and if it is more than 2.0% by weight, undecomposed resin remains and the brightness decreases. therefore,
A range of Oo1 to 2.0% by weight is optimal.

In addition, in the above example, the case where it was applied to a phosphor layer coated by precipitation in a water glass aqueous solution was explained.
The present invention is not limited thereto, and can of course be applied to, for example, a phosphor layer formed by coating with a polyvinyl alcohol/t-chromate slurry used in the manufacturing method of color picture tubes.

Further, in the above example, a case was explained in which polyvinylpyrrolidone was used as a water-soluble organic substance having a pyrrolidone group, but the present invention is not limited thereto. For example, as a compound having a pyrrolidone group, 1-methyl- Of course, 2-pyrrolidone and the like can also be applied.

As explained above, according to the present invention, since a smooth metal back layer is formed without any ring or spot unevenness, the brightness of the picture tube is greatly improved, contributing to improvements in product quality and yield. You can get the very rth effect that you can.

[Brief explanation of drawings]

The figure is a sectional view of a main part of a face plate illustrating an example of the method of manufacturing a picture tube according to the present invention. 1st race... face spray 1゛, 2... fluorescent material 1m
, 3...Polyvinyl alcohol liquid, 4...Myoiso^ Molecular substance precious thin film, 5...Metal back 1 so.

Claims (1)

[Scope of Claims] 1. A phosphor layer is formed on the inner surface of the face plate, and after wetting the phosphor layer with an aqueous solution of a water-based organic substance having a pyrrolidone group, a thin film of an organic polymer substance is formed; A method for manufacturing picture tubes in which a metal back layer is formed on a thin film and then fired. 2. The method for manufacturing a picture tube according to claim 1, wherein the water bathing organic substance having a pyrrolidone group is polyvinylpyrrolidone. 3-1” self-polyvinylpyrrolidone, 001-2.0
The method for manufacturing a picture tube according to claim 2, characterized in that the content is in a range of % by weight.