JPS601721A - Manufacture of picture tube - Google Patents

Abstract

PURPOSE:To obtain a metal backing layer causing perfectly no swelling and coming off of a film by wetting the inside of a bulb with a dilute water solution of water or polyvinyl alcohl containing a granular substance having the grain diameter within a specific range as pretreatment, when forming an organic polymer substance layer on a phosphor layer. CONSTITUTION:A phosphor layer 2 is formed inside a face plate 1, the upper part of said phosphor layer 2 is wetted with water or a water solution 3 containing a granular substance having the grain diameter of 0.1-10mum followed by forming an organic polymer substance layer 4 and forming a metal backing layer 5 on said organic polymer substance layer 4 for performing firing treatment. For instance, after applying a greenly luminous phosphor to the inside of the face plate 1 of a picture tube, the phosphor layer 2 is wetted with a polyvinyl alcohol water solution 3 containing 0.02wt% of alumina grains having the grain diameter of about 3mum while applying a toluene solution of acryl resin by spray and drying to form the organic polymer substance layer 4. Thereafter, the aluminium metal backing layer 5 is formed on said organic polymer substance layer by a vacuum evaporation method for receiving baking treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application 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.

[Background of the invention]

- Normally, when a metal back layer is formed by vapor-depositing a metal such as aluminum on the fluorescent surface of a picture tube, the metal back layer is smooth, almost mirror-like, and bright when observed from the front of the face plate. In order to obtain an image, a suitable pretreatment has conventionally been performed to fill in and smooth the surface irregularities of the previously applied phosphor layer. That is, as shown in FIG. 1, in the manufacturing process of a picture tube, the uneven surface of a phosphor layer 2 coated on the inner surface of a face plate 1 is filled with water or a dilute aqueous solution 3 such as polyvinyl alcohol. The surface of the layer 2 is made into an apparently flat groove, and a solution of an organic polymeric substance dissolved in a solvent is sprayed onto the upper surface of the layer 2, and then dried to evaporate the solvent and water, and the organic polymeric substance layer 4 is formed with a fire. After forming on the upper surface of the light body layer 2 and then depositing metal such as aluminum on the upper surface of this organic polymer material layer 4 as shown in FIG. 2 to obtain a smooth metal back layer 5, Baking treatment is performed at ℃ to decompose and remove organic substances.

However, the aforementioned method of forming a fluorescent surface has the disadvantage that the metal back layer around the face plate panel where no fluorescent material is coated swells and even peels off, which significantly reduces the product value. .

Such blistering and peeling of the metal back layer occurs because there are no pinholes or cracks in the metal back layer 5 formed around the pulp, and the decomposition gas of the organic polymer material layer generated during the baking process is caused by the aluminum metal back layer. This was caused by lifting the layer.

In addition, in the area where the phosphor is coated, some pinholes and cracks occur in the organic polymer material layer 4 and the metal back layer 5 due to the unevenness of the surface of the phosphor layer 2, and the organic decomposed gas is Since the metal back layer 5 was volatilized without being lifted, no blistering or peeling occurred.

[Purpose of the invention]

Therefore, the present invention has been made in view of the above-mentioned situation, and its purpose is to produce a picture tube manufacturing method that makes it possible to obtain a metal back layer that does not cause any blistering or peeling of the film. Our goal is to provide the following.

[Summary of the invention]

In order to achieve such an object, the present invention provides a pretreatment method for forming an organic polymer material layer on a phosphor layer using water or polyvinyl alcohol containing particulate matter with a particle size of 0.1 to 10 μm. The inner surface of the valve is wetted with a dilute aqueous solution such as

According to this method, since the particulate matter adheres to the peripheral part of the pulp where the phosphor is not coated, unevenness is formed in the organic polymer material layer, and some pins are formed in the metal back layer. Holes and cracks form. Therefore, the organic decomposition gas generated in the baking step evaporates without lifting the metal back layer, and a good picture tube without blistering or peeling of the metal back layer can be obtained.

In this case, the 0.1 to 10 μm granular material is
Effects were obtained with both inorganic substances such as alumina (AI20a) and silica, and organic substances such as acrylic resin and polystyrene resin. The concentration of particulate matter in a dilute aqueous solution such as water or polyvinyl alcohol is determined by the material 1 of the particulate matter.
Although it varied depending on the particle size, a significant effect was obtained at 0.1% by weight or more.

[Embodiments of the invention]

3- Next, embodiments of the present invention will be described in detail.

Example 1 First, green-emitting phosphor Zn2 was coated on the inner surface of the face plate of a picture tube by a precipitation coating method in a water glass solution.
After applying S io4:Mn, a polyvinyl alcohol aqueous solution containing 0.02% by weight of alumina particles with a particle size of approximately 3 μm (polyvinyl alcohol is 0% of the total amount in terms of solid content)
．． 2% by weight), and then a toluene solution of acrylic resin was applied by spraying and dried to form an organic polymer material layer. Thereafter, a metal back layer of sialuminium was formed on this organic polymer material layer by vacuum evaporation, and a baking treatment was performed at about 420° C. for about 1 hour.

The picture tube thus obtained was in extremely good condition with no blistering or peeling of the aluminum film over the entire inner surface of the face plate.

Embodiment 2 Next, a case where the method is applied to a color picture tube will be described. First, green, blue, and red light-emitting phosphors consisting of striped patterns formed by coating with polyvinyl alcohol and dichromate-based slurry were applied to the inner surface of the face plate panel, and then polystyrene resin 0 with a particle size of about 1 μm was applied. The phosphor layer is wetted with a polyvinyl alcohol aqueous solution containing .2% by weight (polyvinyl alcohol is 0.2% by weight based on the total amount), and then a toluene solution of acrylic resin is spray applied and dried to form an organic polymer material layer. was formed. Thereafter, an aluminum metal back layer was formed on this organic polymer material layer, and baking treatment was performed at about 450° C. for about 1 hour.

The color picture tube thus obtained was in extremely good condition, with no bulging or peeling of the aluminum film over the entire inner surface of the face plate.

〔Effect of the invention〕

As explained above, according to the present invention, bulges can be prevented.

Since a good metal back layer without peeling can be obtained, an extremely excellent effect can be obtained that can contribute to improving the quality of picture tubes.

[Brief explanation of the drawing]

FIGS. 1 and 2 are sectional views of essential parts for explaining the method of manufacturing a picture tube according to the present invention. 111...Face plate, 2@-phosphor layer,
3...Aqueous solution, 4...Φ organic polymer material layer, 5...
...Metal back layer. 7- Figure 1 Figure 2 97-

Claims (1)

[Claims] forming a phosphor layer on the inner surface of the face plate, wetting the phosphor layer with water or an aqueous solution containing a particulate material having a particle size of 0.1 to 10 μm, and then forming an organic polymer material layer;
A method for manufacturing a picture tube, characterized in that a metal back layer is formed on the organic polymer material layer and subjected to firing treatment.