JPS62145626A - Manufacture of board for display - Google Patents

Abstract

PURPOSE:To form a board for display which is excellent in emission char acteristics having no color shade and no deterioration in luminous efficiency and has the fluorescent material of uniform thickness even if the board is a meter-sized board, by making a photosensitive resin compound from polyvinyl alcohol and an organic curing agent. CONSTITUTION:The prior photosensitive resin compound is substituted for a compound made from polyvinyl alcohol and an organic curing agent, so that the forming of a uniform thick paint film and the problems owing to the existence of heavy metals can be mainly solved. In view of coating ability, developing suitability, the lubricating ability of a cured film and the like, the polyvinyl alcohol of about 87-89% saponification degree is favorable as a polyvinyl alcohol to be used. And in view of the luminous efficiency of a fluorescent material, the suitable film thickness (10-20mum) of a fluorescent element, the dispersion stability of the fluorescent material and the like, the polyvinyl alcohol of high polymerization degree, especially the polyvinyl alcohol of not less than 1,000 polymerization degree is suitable.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for manufacturing a display substrate, and more particularly, the present invention relates to a method for manufacturing a display substrate, and more particularly, the present invention relates to a method for manufacturing a display substrate, and more specifically, a method for manufacturing a display substrate, in which a phosphor formed in alignment with an electrode has a uniform thickness over the entire large substrate. The present invention relates to a method for easily providing a display substrate that can be used for display purposes.

(Prior Art) In recent years, as image technology has progressed, large-screen displays have been required for home use, educational use, industrial use, and public use. As these large displays, cathode ray tube type direct viewing type and projection type displays using screens have been developed, but these displays have large depth and overall weight, etc. from,
The problem is that it requires a large amount of space. From this point of view, there is a strong demand for a so-called 1V display that is flat and thin, such as a wall-mounted television.

(Problem to be Solved by the Invention) The above display substrate is made by regularly arranging phosphors that emit red, green, and blue light on the face plate. 4j. Applying liquid V, in which a desired phosphor is uniformly dispersed in a liquid photosensitive resin composition, to the substrate surface on which one electrode is formed;
It is formed by patterning according to a conventional method, but as the substrate surface is uneven due to the formation of electrodes, it is difficult to maintain a constant coating film thickness, and as a result, the phosphor remains. There is a problem in that variations occur and color unevenness occurs when emitting light.

Particularly in the case of a color display, three types of phosphors are sequentially applied 41, which causes problems such as entrapment of air bubbles and damage to the quencher and electrodes previously applied. Particularly, such problems become more pronounced when a large-sized, for example, meter-sized substrate is used. Therefore, conventionally, it has not been possible to obtain a display substrate that is satisfactory for large, meter-sized substrates.

In addition, photosensitive resin compositions consisting of polyvinyl alcohol and dichromate have been widely used as photosensitive resin compositions with good coating properties for conventional television cathode ray tube displays. Unlike the above display, chromium ions remain in the phosphor, and the remaining chromium ions in the phosphor deteriorate the luminescence properties of the phosphor. Furthermore, since chromium ions are harmful, problems arise in the treatment of wastewater generated during production.

Therefore, the main object of the present invention (1) is to provide a display substrate that has a uniform phosphor thickness even on a large-sized, especially meter-sized substrate, and has excellent luminescent properties without color unevenness or deterioration of luminescent properties. It is to provide.

Another object of the present invention is to provide a method for manufacturing a display substrate without using chromium or other materials that adversely affect the luminescent properties of phosphors, that is, without causing problems in wastewater treatment. It is to provide.

Furthermore, another object of the present invention is the above (1) and (2) [
The first objective is to provide a large color display substrate.

(Means for Solving the Problems) As a result of intensive research in order to solve the above-mentioned drawbacks of the prior art and achieve the above-mentioned object of the present invention, the present inventor has developed a method for manufacturing a display substrate. It has been found that the above object of the present invention can be achieved by using a photosensitive resin composition consisting of polyvinyl alcohol and an organic curing agent, and preferably by employing a doctor blade method as the coating method. The invention has been completed.

That is, the present invention applies a photosensitive resin composition in which a phosphor is dispersed on a substrate on which electrodes of arbitrary shapes are formed,
In the method for producing a display board, which involves exposing, developing and baking, the above-mentioned photosensitive resin composition is characterized in that it consists of polyvinyl alcohol and an organic curing agent.Next, the production of the present invention The method will be explained in more detail.

The steps for manufacturing the display plate of the present invention are as shown diagrammatically in FIGS. 1a to 1d.
For example, an electrode 2 is provided on a glass substrate 1 by a thick film printing method, and then a photosensitive resin composition containing a phosphor is applied to the entire surface of the electrode surface by an arbitrary coating method, dried, and then the photosensitive resin composition is applied. A composition layer 3 is formed, and after pattern exposure through a mask (not shown) having a desired pattern, it is developed, leaving the cured phosphor layer R, and removing the layer in the non-exposed area and drying. At this stage, a monochrome display substrate is obtained. In the case of a color display substrate, the same method as above is used, including the phosphor used for the above patterning, using a red-emitting phosphor R, a green-emitting phosphor G, and a blue-emitting phosphor B. Na coating 11
By repeating drying, exposure and development, and patterning a total of three times, red (R), green (G) and r
The phosphors of the three colors (B) are arranged regularly. And finally 7. t; By firing the board at high temperature, a full-color display substrate can be obtained.

In L, the thickness of the substrate is generally 1 to 10 mm, the electrodes are mainly provided in a stripe shape, and the thickness is generally 0.11-100JL, and lJ of the stripe-shaped electrode is approximately 50 to 500 pm, and the layer of the photosensitive resin composition has a dry thickness of about 20 to 200 m.

The above-mentioned 'M manufacturing process itself may be the same as the conventional technology, and therefore, the electrode materials used, the electrode forming method, the substrate material, the coating method, the exposure, development, baking methods, or their conditions are all the same as the conventional technology. The same is fine.

However, in the conventional method consisting of the above steps, as the photosensitive resin composition used is one consisting of polyvinyl alcohol and a laminate.
This caused various problems.

The first feature of the present invention is that polyvinyl alcohol is used instead of the conventional photosensitive resin composition described above. j, curing agent), which mainly solves the problems caused by the formation of a coating film of uniform thickness and the presence of heavy metals.

As the polyvinyl alcohol used in the present invention, any conventionally known polyvinyl alcohol can be used, but from the viewpoint of coatability, developability, swelling property of cured film, etc. Polyvinyl alcohol of a certain degree is preferable.

Also, the luminous efficiency of the phosphor, the suitable film thickness of the phosphor element (io~
20 gm), and from the viewpoint of phosphor dispersion stability, etc., polyvinyl alcohol with a high degree of polymerization, particularly polyvinyl alcohol with a degree of polymerization of 1.000 or more, is suitable.

Further, the curing agent used in the present invention is an organic curing agent, and any conventionally known organic curing agent such as diazonium salts, phenyl azides, and 0-quinone azides can be used; From the viewpoint of developability, sinterability, etc., diazonium salt-based curing agents are particularly suitable, and a particularly useful one is a formalin condensate of p-diazodiphenylamine (degree of condensation 2 to 3).

The amount of such an organic curing agent added to polyvinyl alcohol is 2 to 7 times the amount of polyvinyl alcohol, li
t% is preferable, and if it is less than 2%, curing of the polyvinyl alcohol will be insufficient and film lifting may occur during development. Further, if the amount added exceeds 7%, only the surface layer may be cured due to coloring of the diazonium salt, which may result in poor curing as a whole, which is not preferable.

The phosphor to be added to the above photosensitive resin composition is as follows:
Any of the phosphors used in conventional color ceilings can be used; for example, as a red-emitting phosphor, Y
2O2S: Eu, green luminescent phosphor: ZnS:
Cu:Ag, ZnS:Ag as a blue-emitting phosphor
etc. are suitable. Of course, phosphors other than these preferred phosphors can also be used.

Such a phosphor is Ushiki Polyvinyl Alcohol 100
Preferably, it is added in a proportion of about 300 to 800 parts by weight.

The photosensitive resin composition used in the present invention has the above-mentioned components as essential components, but any other conventionally known additives may be included as necessary.

In the present invention, the above-mentioned essential components and optional components are made into a coating liquid using water or a mixture of water and a water-soluble organic solvent such as alcohol. The amount of solvent used varies depending on the type of polyvinyl alcohol used and the C degree of the phosphor, but generally the total solid content is about 20 to 40% by weight and the viscosity is 500 to 3. A range of 0OOcps is preferable. As a method for dispersing a phosphor in a photosensitive resin composition, any conventional method of dispersing a solid in a liquid, such as a ball mill, sand mill, roll mill, speed line mill, etc., can be used. In the present invention, by using the photosensitive resin M1 composition containing the above-mentioned photoreceptor, a four-spring with a uniform thickness can be obtained, and it also has excellent curability, developability, etc. , Part 1: Since problems such as nichrome ions do not occur, many problems of the prior art have been solved.

Any conventional coating method such as doctor blade coating, Miyahe coating, roll coating, screen coating, spinner coating, etc. can be used to apply the photosensitive resin composition on the substrate provided with the desired electrodes. However, doctor blade coating is the most suitable from the viewpoints of preventing air bubbles from entering, phosphor settling, etc., preventing damage to the electrode due to uneven electrode substrates, preventing air bubbles from entering, uniformity of coating amount, etc. I found out. In particular, since the electrodes 2 on the substrate 1 are generally provided in a striped pattern as shown in FIG. By doing this, there are no problems such as inclusion of bubbles due to electrode resistance, damage to the electrodes, uneven coating, etc., and a smooth coating with a uniform thickness can be achieved. We found that it is possible to achieve this.

The coating film formed as described above varies depending on the thickness of the electrode, but generally has a thickness of about 5 to 50 mm when dried.
Approximately JLm is preferable. The drying of the coating film, curing by pattern exposure, development by elution of unexposed areas, and baking, etc. and their respective conditions are as described above, and as exemplified in the examples below, there are no particular limitations. Instead, it may be the same as in the prior art.

(Function/Effect) According to the method of the present invention as described above, a photosensitive resin composition consisting of polyvinyl alcohol and an organic curing agent, particularly a diazonium salt type curing agent, is used, and further combined with this, By preferably adopting the doctor blade method as the coating method, even if the substrate is large, for example meter-sized, and the substrate surface is uneven with electrodes, coating with a uniform thickness over the entire surface of the substrate is achieved. As a result, various problems caused by non-uniform film thickness in conventional methods have been solved.

Therefore, according to the present invention, the present invention has a large size that has been difficult to provide in the past, and has uniform luminescence over the entire substrate, and can be used in a wide variety of flat-type cathode ray tubes (CRTs),
A display substrate useful as a phosphor-excited display such as a fluorescent display tube or a plasma display, particularly a full-color display substrate, is provided.

Furthermore, as a result of using the specific curing agent of the present invention, there is no need to use dichromate as in the conventional technology, which eliminates the problem of luminescent deterioration of the phosphor due to residual chromium ions, etc., and waste water treatment during manufacturing. issue was also resolved at the same time.

Next, the present invention will be explained in more detail with reference to Examples. In addition, parts or % in the text are based on heavy Fi-standard unless otherwise specified.

Example Three types of mill bases were prepared by dispersing the following components in a ball mill for 2 hours.

Milbase A Polyvinyl alcohol (10% aqueous solution, degree of polymerization 2.40
0, degree of saponification 88 mol%) 45 parts phosphor (Y202 S
: Eu, red luminescent material) 22 parts ion-exchanged water 22 parts methanol 111 parts Milpase polyvinyl alcohol (10% aqueous solution, degree of polymerization 2.40)
0, degree of saponification 88 mol%) 55 parts phosphor (ZnS:Cu
+Ag, green luminescent material) 22 parts Ion-exchanged water 11 parts Methanol 12 parts Millbase C Polyvinyl alcohol (10% aqueous solution, degree of polymerization 2.40
0. saponification degree 88 mol%) 55 parts phosphor (ZnS:Ag
, blue luminescent material) 11 parts of ion-exchanged water 12 parts of methanol Next, 0.225 parts of diazoresin (D-011, manufactured by Shinko Giken Co., Ltd.) was added to Millbase 1001 described below to prepare a photosensitive resin composition. A, B and C were created. ''; After coating a glass substrate with a size of 100 cm x IOO cm x 5 m++* on which electrodes were formed by thick film printing using a doctor blade coater, the photosensitive resin composition A was dried at 55 ° C. for 30 minutes. Ta. The doctor blade clearance was 20,071 m, and the phosphor coating after drying was 15 pm. After pattern exposure through a mask, spray development was performed with water, non-exposed areas were selectively removed, and then dried at 90° C. for 15 minutes.

The same operation was carried out for photosensitive resin composition B, and photosensitive resin composition C. After patterning the three-color phosphors of R, G, and B, this was heated at 350°C for 1 hour and then at 440°C.
The mixture was fired for 2 hours to produce a c'-shaped nine-body structure. As a result of irradiating this phosphor pattern with ultraviolet light, a clear and uniform luminescent image 11) was created over the entire substrate. Also,
It was also confirmed that these did not cause luminescent deterioration over time.

[Brief explanation of drawings]

FIG. 1 is a diagram schematically showing the steps of the manufacturing method of the present invention, and FIG. 2 is a diagram schematically showing coating by a doctor blade coater. 1; substrate 2, '; ii pole 3; polar light; photosensitive resin composition Kutablaid R; red light-emitting phosphor G: green light-emitting phosphor B; blue light-emitting phosphor

Claims (1)

[Scope of Claims] (1) A method for manufacturing a display substrate in which a photosensitive resin composition in which a phosphor is dispersed is applied onto a substrate on which an electrode of an arbitrary shape is formed, and then exposed, developed, and baked. The above manufacturing method, wherein the photosensitive resin composition comprises polyvinyl alcohol and an organic curing agent. (2) The manufacturing method according to boxed item (1), wherein the organic curing agent is a photodegradable curing agent. (3) Organic curing agent is 89% diazonium salt type curing agent
Claim No. (1) which is polyvinyl alcohol
The manufacturing method described in section. (6) The manufacturing method according to claim (1), wherein the polyvinyl alcohol has a degree of polymerization of 1.000 or more. (7) The manufacturing method according to claim (l), in which the photosensitive resin composition is applied by a doctor blade method.