JPS60155533A - Black powder for black matrix color tv tube - Google Patents

Abstract

PURPOSE:To form a fine black matrix by oscillation method, by using black powder for black matrix color TV tube having a density falling within a specific range. CONSTITUTION:The compound having the composition of formula I (M is Ca or Sr; A is Co, Ni or Fe; 0<=x<=0.6) and formula II (A' is Co or Ni; 0<=x<=0.5) and having a specific gravity of 3.7-7.2 and larger particle diameter than the fluorescent material, is used as the black powder for black matrix color TV tube. A black matrix can be produced by the powder oscillation process of the black powder for black matrix using a photosensitive powdery sticking agent.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a black powder for a black matrix color cathode ray tube.

[Background of the invention]

Conventionally, the black matrix of color picture tubes was made by applying a photosensitive resin liquid to the inner surface of the face plate.

Drying, exposure, development, drying, coating and drying of carbon dispersion,
It is formed through the steps of peeling off and drying a photosensitive resin film. This method has problems such as complicated steps and the necessity of using a large amount of water for developing and peeling off the photosensitive resin.

Some of the inventors of the present invention previously published
In No. 1, based on the knowledge that photodecomposition products of aromatic diazonium salts have the ability to accept powder particles, a thin layer containing the resulting sticky aromatic diazonium salt is formed on the surface of a substrate by exposure to light. After the layer receives the powder particles, the remaining powder particles are removed from the thin layer, which is repeated once or twice or more, so that the desired shape of the powder is deposited on the surface of the substrate. A method for forming the coating layer was proposed.

Forming a black matrix by this method involves exposing the inner surface of a color cathode ray tube face plate to light and imparting phosphors to each of the three types of phosphors using the above method. This is possible by bringing a black powder substance into contact with the paint film.

The application of powder by this method is carried out by a rocking method. The figure is a conceptual diagram of the rocking method. First, the principle of the rocking method will be explained using this diagram. A color cathode ray tube face plate 1 is fixed to a support frame 2. This support frame is integrated with the variable angle rotor 4, and by moving the rotor 4 in the direction of the arrow, it can be tilted by 55 degrees alternately in the short side direction of the face plate with respect to the horizontal plane of the face plate. In addition, the support frame 2 has a reed on the support plate 5, and by moving the angle-changing rotor 3 in the direction of the arrow, the support frame 2 is rotated by 23 degrees alternately in the long direction of the side on the face plate with respect to the horizontal plane of the face plate. Can be tilted. That is, by moving the rotors 3 and 4 at the same time, the aggregate 6 of the injected powder particles is slid in a zigzag pattern as shown by the broken line, thereby applying the powder to the adhesive substance. can. With this method, it is not possible to apply carbon powder, which has conventionally been used as a black matrix material.

[Purpose of the invention]

An object of the present invention is to define the specific gravity of a black powder suitable for manufacturing a black matrix color picture tube by the rocking method, and to provide a black powder suitable for this purpose.

[Summary of the invention]

The invention is achieved with a black powder having a true specific gravity of 3.6 to 7.2. A compound that satisfies this condition is, for example, FeT10s lLal-3lLa1-3C, where M:Ca, 8r A:Co+Ni+Fe+Ox<
0.6) and La2-x 4/r XA' 04 (
However, A': Co, N i , 0X<0.
5) etc.

The present invention will be explained in detail below. The deflection of the short side of the color cathode ray tube faceplate shown in the figure is an operation necessary to move the powder aggregate.

The ease of movement of the powder depends on the size of this angle14
In case of inch face plate, coating efficiency is 49-55
The degree is appropriate. In addition, changing the angle of the long side of the color cathode ray tube face plate is an operation to spread the powder over the entire surface of the face plate. From the above, in order to move the powder, at least the angle of the face plate (face plate The powder aggregate needs to start moving when the angle (with respect to the horizontal plane) reaches 49 degrees. Also, the reason why we set the upper limit of the angle of the face plate to 55 degrees is because if the angle is larger than this, it will collide with the skirt of the face plate with force, causing the powder aggregate to collapse and become stuck. , because it scatters out of the face plate. As a result of examining the ease of movement of powder from various aspects, we found that it is related to the specific gravity of the powder. That is, powders of various specific gravity were placed on a face plate (14 inches) coated with aromatic diazonium salt,
As a result of examining the specific gravity of the powder that starts moving when the angle of the face plate is set to 49 degrees, it was found that the specific gravity was 3.7 or more. In addition, if the specific gravity increases, it becomes easier to move, but if the specific gravity increases beyond 7.2, the three types of fluorescent films that were formed before applying the black powder will be scraped off (fluorescence 4% or more of the film), which is not preferable.

Note that when using a 6-inch 2-ace plate, its curvature is smaller than that of a 14-inch face plate, so even if the inclination angle of the face plate is 35 degrees, the specific gravity is 3.7. Powder can be applied.

FeTjOs is a desirable black powder.

Lai, xMxAOs and La2-XSr xA'
The specific gravity is shown in the table below.

As described above, these compounds satisfy the conditions of the present invention and can form a clean black matrix by the rocking method. The particle size of the black powder is desirably larger than the particle size of the phosphor in order to prevent it from being mixed into the previously applied phosphor film.

Although we have not yet found a black powder with a specific gravity that does not reach 3.6, experimentally there is no problem with white powder.
ioa < specific gravity 3.5), AL2stOs (specific gravity 3
．． 2) and Ce (PO3)3 (specific gravity 3.3). These did not move even when the tilt angle of a 14-inch color cathode ray tube 7 x-splate (coated with aromatic diazonium salt) was set to 49 degrees. Furthermore, since there were no suitable black particles with a specific gravity exceeding 7.2, we substituted white powders EuzOs (specific gravity 7.4) and Gd20a (specific gravity 7.4) and conducted the same experiment as above. I did it. These powders have a faceplate (14 inches in size) with an inclination angle of TL-49.
It was found that although it moves easily when applied to a certain degree, the side of the luminescent film formed before application is about 1H4 (J4 area ratio). This is undesirable because it reduces the brightness of the color cathode ray tube.

[Embodiments of the invention]

The present invention will be explained below using examples.

Examples 1 to 9 A photosensitive composition (photoadhesive) containing 4-dimethylaminobenzenediazonium chloride zinc chloride double salt was applied to a 14-inch color cathode ray tube face plate and irradiated with light through a shadow mask. (ultraviolet rays), give adhesiveness to the first coating position, and add blue phosphor (ZnS:Ag, CL) there using the rocking method. Apply and develop with air spray. Continuing, in the same way as above, green phosphors (ZnS:Cu, Al
l.

AL) and red phosphor (Y2O2S: E u ) (
D coating.

Perform development. Next, the entire surface of the coating film is irradiated with ultraviolet rays, and each substance shown in the table below, which is a black powder, is applied on it by a rocking method, and then developed by air spray to form a black matrix. The condition of the paint film was investigated. As a result, a dense black matrix was obtained in all cases.

〔Effect of the invention〕

As mentioned above, according to the black powder for a black matrix of the present invention, it is possible to form a black matrix by shaking the powder using a photosensitive powder adhesive substance. This has a great effect on simplification, etc.

The figure is a conceptual diagram regarding application of powder by the rocking method.

Claims (1)

[Claims] 1. A black powder for black matrix color cathode ray tubes having a specific gravity of 3.7 to 7.2. 2.Chemical formula FeT tQ31 L a 1- x M
x AOs (However, M: Ca, S'r A: Co, Ni
, i”eO< X≦0.6 ) + L az−xs
r x A' 04 (However, A': Co, Ni o≦X
The black powder for a black matrix color cathode ray tube according to claim 1, which is represented by O.5).