JPH02215840A - Filming emulsion for cathode ray tube - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is directed to the production of cathode ray tubes 1, for example, color picture tubes, in which a phosphor layer is formed on the inner surface of the panel, and then a metal reflective film is formed on the phosphor layer. Regarding the organic filming emulsion used as the base for forming the film, in particular, a film for cathode ray tubes that is suitable for forming a smooth metal reflective film with excellent reflectivity without causing blistering of the metal reflective film. ming emulsion.

[Conventional technology]

When forming the phosphor screen of a color picture tube, normally a green, blue, and red emitting phosphor layer is formed on the inner surface of the panel, and then aluminum is vapor-deposited to form a reflective film. In order to obtain a high reflectance, a so-called filming process is performed prior to aluminum vapor deposition.

The purpose of this filming is to smooth the uneven surface of the phosphor layer by covering it with a film such as acrylic resin, but one of the important requirements in this process is to reduce the reflectance of the aluminum vapor-deposited film. In order to increase the brightness of the phosphor screen, it is necessary to make the formed film smooth. However, the smoother the film surface, the higher the degree of sealing by the vapor-deposited aluminum film, and in the subsequent baking process, the gas generated by the decomposition of acrylic resin, etc., loses its escape port, and as shown in Figure 2, the aluminum film becomes more tightly sealed. This causes the membrane to swell, making it more likely to peel off.

As a countermeasure for this, for example, by spraying a liquid containing particulate material onto a smooth film surface to make the particulates adhere, and using the shading effect of the protrusions of the surface deposits to form fine pinholes in the aluminum vapor-deposited film. , a method has been proposed to reduce the occurrence of blistering and peeling of the aluminum film by escaping decomposed gas from the pinhole (Japanese Patent Publication No. 51-4).
No. 22).

[Problem to be solved by the invention]

However, in the case of using the above method, there is a problem that the process time becomes longer because the process of eruption is added after filming, and also, when the amount of eruption adhesion becomes excessive, the aluminum evaporated film The diameter of the resulting pinhole becomes large, which impedes improvement in the brightness of the phosphor screen, and in order to avoid this, there is also the problem that fine adjustment and management of the jet nozzle, air pressure, etc. is required.

An object of the present invention is to solve the above-mentioned problems of the prior art, to enable the simultaneous formation of a filming film and protrusions on the film, without requiring a process bath, and to improve the brightness of the phosphor screen. An object of the present invention is to provide a filming emulsion for cathode ray tubes that can maintain improved brightness.

[Means to solve the problem]

The above objective is to create a filming emulsion that contains acrylic/water emulsion as its main component, has poor compatibility with the acrylic component, and has a minimum film forming temperature (Mini Um Film-
Forming Temperature; M F
This can be achieved by forming a filming emulsion containing, as an additive component, a water emulsion of an organic material whose T ) is higher than that of the acrylic component.

[Effect]

After the above filming emulsion is coated on the phosphor layer, the acrylic component is fused to form a smooth continuous film when heated and dried at a temperature higher than the MFT of the acrylic component and lower than the MFT of the additive components. However, organic material components that are not compatible with the acrylic component and have a higher MFT than the acrylic component precipitate on the acrylic film to form fine protrusions.

Next, when aluminum is vapor-deposited on the surface of the filming film, minute pinholes are formed scattered on the smooth surface of the vapor-deposited film due to the shading effect of the protrusions, and when baking is performed afterwards, decomposition occurs. Since the gas escapes from the pinhole, the deposited film does not bulge or peel.

〔Example〕

Below, regarding the filming emulsion for cathode ray tubes of the present invention,
This will be specifically explained using examples.

The composition of the filming emulsion used in the examples is as follows.

Acrylic emulsion: 13% (Brimal 874 Nippon Acrylic Co., Ltd. 111) Polystyrene emulsion: 0.05% Acrylic acid/cellulose copolymer: 1% (thickener) Water: Balance Here, the numerical values of the composition ratios indicate weight % as solid content, and the MFT of the acrylic component is about 42°C, and the MFT of the polystyrene component is about 100°C.

The emulsion described above is used to coat the phosphor layer provided on the face panel, and then heated to a temperature of about 4°C above the MFT of the acrylic component.
Drying was performed at 3°C. At this humidity, the acrylic components fuse together to form a smooth continuous film, but the polyethylene component has poor compatibility with the acrylic component and
Since F'T is high, it precipitates on the surface of the acrylic film. In this case, the acrylic emulsion and polystyrene emulsion can be mixed uniformly in the emulsion state, so when the acrylic component forms a film, the polystyrene component is not unevenly distributed and uniform precipitation occurs (Figure 1). ).

Next, about 3000 angstroms (
When aluminum is vapor-deposited to a thickness of 100 mm (300 mm) thick, minute pinholes are formed on the smooth surface of the vapor-deposited film due to the shading effect of the polystyrene precipitate. escaped from the pinhole, and an aluminum vapor-deposited surface without blistering or peeling could be obtained.

In addition, when we performed film formation, aluminum evaporation, and baking in the same manner as above using samples with different polystyrene emulsion contents in the above ingredients, we found that the smoothness of the acrylic film itself was lost when the amount of polystyrene exceeded 2%. On the other hand, when boristyrene io, 01%
In the following, the effect of preventing blistering of the aluminum vapor deposited film was lost.

〔Effect of the invention〕

As described above, the filming emulsion for cathode ray tubes is made into a filming emulsion according to the content of the present invention, that is, it contains an acrylic emulsion as a main component, has poor compatibility with the acrylic component, and has a higher M F T than the acrylic component. By using a filming emulsion containing a water emulsion containing a highly organic material as an additive component, we have solved the problems of the conventional technology and achieved high reflectance without causing blistering or peeling during the baking process. It was possible to provide a filming emulsion for cathode ray tubes that can provide an aluminum deposited film that retains its properties.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a phosphor screen showing a filming film formed using the filming emulsion for a cathode ray tube of the present invention, and FIG. 2 is a sectional view of a phosphor screen showing blistering of an aluminum vapor-deposited film. DESCRIPTION OF SYMBOLS 1... Face panel, 2a... Green light emitting phosphor layer, 2b... Blue light emitting phosphor layer, 2c... Red light emitting phosphor layer, 3... Filming mainly composed of acrylic resin Film, 4... Polystyrene resin precipitate, 5... Aluminum vapor deposited film, 6... Aluminum vapor deposited film blisters.

Claims (1)

[Claims] 1. A cathode ray characterized by having an acrylic/water emulsion as a main component and an organic substance/water emulsion as an additive component that has poor compatibility with the component and has a higher minimum film forming temperature than the component. Filming emulsion for tubes.