JPS5848985B2 - Keikomenkeiseihouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling a fluorescent surface shape of a cathode ray tube.
This provides an effective method that skillfully utilizes phase separation of emulsions.

-4) In order to improve the brightness, a reflective film made of an aluminum film is provided on the fluorescent surface of the cathode ray tube.

In this case, a well-known method is to provide an organic film on the fluorescent film and form aluminum on the film by vapor deposition.

In these steps, providing an organic film is called filming, and aluminum vapor deposition is called metal backing.

Therefore, this method requires a film formation process called filming for metabacking after forming the fluorescent film.

There are two methods for this coating process, one is to spray a lacquer solution, and the other is to flow-coat a water-based emulsion paint, each of which has its advantages and disadvantages.

The present invention relates to a method that completely eliminates such a filming step, and provides a novel method in which a filming film is formed simultaneously with the completion of a fluorescent film.

A suspension or slurry in which phosphor particles are suspended in an aqueous adhesive solution is generally used as a coating solution for a phosphorescent film. A solution obtained by dissolving in a solvent with a specific gravity lower than that of water and a lower vapor pressure than water is made into an emulsion and stably suspended, and when a fluorescent film is formed using this slurry, the coating film dries. In the process, the stability of the emulsion is destroyed, and the particles mutually condense into large particles, which eventually undergo phase separation and become a single unit, floating and separating as a continuous body above the fluorescent film.

As the drying progresses further, the solvent is evaporated and an organic film is formed on the fluorescent film to form a filming film.

According to this method, the fluorescent film and the filming film can be formed at the same time, so the process is omitted and the economical effect is extremely large.

Examples will be described below. Example 1 Approximately % of toluene is added to pure water, mixed thoroughly, and separated to remove only water.

Separately, prepare a 3% toluene solution of Inptyl polymethacrylate resin.

To 100 parts of the separated water, 20 parts of phosphor, 3 parts of polyvinyl alcohol, and as a surfactant, for example, Tween 200
．． A suspension is prepared so that the composition is 1 part.

Add 30 parts of the toluene solution to 100 parts of this suspension and perform ultrasonic stirring to prepare an emulsion to form a slurry.

When this slurry was spin-coated onto a glass plate or other panel glass and dried with a heater, a filming film could be formed at the same time as a fluorescent film.

Example 2 The above is a case of monochrome storage, but in the case of a color picture tube, it is necessary to form three-color phosphors into dots or stripes, and an exposure method using photography is generally used. It is well known that it has been adopted.

Therefore, when development is performed after coating the first color, it becomes difficult to develop because the organic film formed on the top of the fluorescent film is continuous.

Therefore, in the case of a color picture tube, it is necessary to use a material having photosensitivity as well as an organic polymer capable of forming a film.

For example, solvent-based KPR (Kodak Photoresist) may be used in place of the inptyl polymethacrylate.

Since this film is insoluble in solvent only in the exposed areas, first develop it with a solvent such as toluene, leaving only the parts where dots are to be formed on the filming film, and then perform normal water development to develop the dots. A dot is also formed.

The same applies to striped fluorescent surfaces.

Claims (1)

[Claims] 1. A solution of a solvent-based polymer with film-forming ability dissolved in a water-incompatible solvent is suspended in an aqueous phosphor slurry in the form of an emulsion, and this is used to form a phosphor coating within the panel. 1. A method for forming a fluorescent surface of a cathode ray tube, characterized in that a filming film is formed at the same time as the film is formed.