KR900001601B1 - The manufacturing method of fluorescent film in color crt - Google Patents

Abstract

A fluorescent film for color CRT is manufactured by coating and drying a photo-sensitive resin compsn. on the inner surface of color CRT faces; exposing a preditermined-surface of the fluorescent film mask to UV; spray-applying fluorescent powder on the inner of the face and then removing the excess poder; and washing the inner of the face with pure water and contracting-sticking the fluorescent pattern by treating with a boric acid soln., to form the red, blue, green- fluorescent pattern of color CRT. The photosensitive resin compsn. comprises 10-50% pure water, 0.5-5% kalium dichromate, as a plastisizer including 0.5-5% diethylene glycol, 0.5-5% urea, 0.5-5% surfactant etc, the plastisiger being contd. in 20-50 W/V%.

Description

Method for producing fluorescent surface using photosensitive resin composition for color cathode ray tube

1 is a process diagram showing the method of the present invention.

2 is a photograph showing a stripe shape of a fluorescent film obtained by a conventional slurry coating method.

3 is a photograph showing a stripe form of a fluorescent film obtained by the present invention.

* Explanation of symbols for main parts of the drawings

2: face 4: photosensitive film

6: mask 8: fluorescent film

The present invention relates to a fluorescent surface manufacturing method using the photosensitive resin composition for forming the fluorescent surface of the color cathode ray tube. On the inner surface of the face of the color cathode ray tube, three phosphor patterns of red, blue, and green are arranged to form a fluorescent surface. As a method of coating these phosphors to form a predetermined pattern on the inner surface of the face, a slurry coating method using a photosensitive resin composition mixed with phosphors, and exposure to mercury-excited ultraviolet rays to decompose the diazonium salt, wherein zinc chloride is in the air A dry method using a photosensitizer made of a diazonium salt that absorbs water and exhibits adhesion.

In the former slurry coating method, a phosphor slurry is applied to an inner surface of a face, and only a predetermined portion is exposed through a shadow mask, and then a non-exposed portion is washed and developed. The exposure time is long and exposed due to the low sensitivity. Ultraviolet rays cause light scattering on the surface, and thus there is a problem in that fine and clear phosphor patterns cannot be obtained.

In the latter drying method, the photosensitive member is applied to the inner surface of the face and dried, and then exposed, scattered and adhered to the phosphor, the phosphor remaining in the non-exposed part is washed with air, and a loading agent is applied to give the exposed photosensitive agent. As a method of forming by disappearing, it is possible to obtain a fluorescent pattern of a higher quality than the slurry coating method described above, but because it needs to be cleaned with air, it is difficult to clean the phosphor remaining in the non-exposed part, which causes a color cup to be applied when the next fluorescent film is applied. There is a thing.

The sharpness of the screen in a color cathode ray tube depends on how fine, straight and right the fluorescent film pattern of three colors of red, blue and green can be formed.

An object of the present invention is to provide a photosensitive resin composition having no change in adhesiveness after exposure and drying and having a wide drying temperature range to obtain a clear fluorescent film pattern.

Accordingly, the photosensitive resin composition of the present invention is 10-50% pure water, 5-30% polyvinyl alcohol, 0.5-5% dichromate salt, 0.5-5% of ethylene glycol 0.5-5% and ethylene glycol 0.5-% and urea 0.5- as a plasticizer. 5%, 0.5-5% acetamide and 0.5-10% butanediol, 0.5-5% paraaldehyde, 0.5-5% dioxane and 0.5-5% surfactant were used to form the photosensitive resin composition in the face of the color cathode ray tube. After coating on the side, and drying the exposure, the phosphor powder is scattered and adhered to the exposed part, and the phosphor is removed with water, and then treated with boric acid solution to shrink and fix the phosphor pattern.

Hereinafter, the present invention will be described as other embodiments in the accompanying drawings. First, the photosensitive resin composition of the present invention is composed of the following materials.

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로 응고된 이온화기로서 공유결합을 가진다. 이 공유결합들은 다른 폴리비닐 알콜체인의 이온화된 기에 의해 포화되어 3차원적 광가교를 이루게 되어 물에 대한 용해도를 상당히 감소시켜 준다.Polyvinyl alcohol: 5-30% is added. It has the property of photocrosslinking due to the reduced trivalent chromium with light having a wavelength of 364nm. That is, the carboxyl group, which is the final degradation product during oxidation and reduction, forms trivalent chromium and octahedral compounds. This carboxyl group is structurally

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It has a covalent bond as the ionizer solidified with. These covalent bonds are saturated by ionized groups of other polyvinyl alcohol chains, resulting in three-dimensional photocrosslinking, which significantly reduces the solubility in water.

Dichromate salt: 0.5-5% is added. Reacts with polyvinyl alcohol to keep photosensitivity stable under heat and other external influences. In the present invention, the dichromate salt showed the best result using potassium dichromate salt.

Diethylene glycol: 0.5-5% is added. Used as a plasticizer. Ethylene glycol: 0.5-5% is added. Determine photosensitivity and dryness. In this experiment, first-class reagents from Japanese quasi-secondary companies were used. Used as a plasticizer.

Urea and acetamide: 0.5-5% is added. These materials, which contain amines, maintain the dry state in the formation of the fluorescent film, and absorb moisture in the air to improve the crystallinity of the fluorescent film. In the present invention, Japanese Hayashi company first grade was used. Used as a plasticizer.

Butanediol: 0.5-10% is added. It is included in the overall composition to act as a plasticizer.

Paraaldehyde and dioxane: 0.5-5% of each is added. It acts as a plasticizer to control the evaporation rate of the composition and keeps the dry state of the photosensitive resin film constant.

Surfactant: It is made by dissolving 6 g of Tamol 731SD manufactured by Rohm & Hass in USA in 100 ml of hot water and adding 4-5 drops of Triton CF-10 dropwise.

The composition process of the above-described material is as follows.

First, diethylene glycol and ethylene glycol are added while stirring pure water and polyvinyl alcohol diluent at room temperature. Stir for about 10 minutes and mix well, then add urea, acetamide and butanediol in that order. With continued stirring, mix paraaldehyde and dioxane and add surfactant. The resulting composition is used by filtration with 400 mesh. The viscosity of this composition and the addition or subtraction of a solid substance are adjusted by adding or subtracting polyvinyl alcohol, pure water, etc. according to the distribution density of a fluorescent film.

In addition, the total content of plasticizers consisting of dieethylene glycol, ethylene glycol, urea, acetamide, butanediol, paraaldehyde and dioxane is limited to 20-50 W / V%. When the content of the plasticizer is less than 200W / V%, the fluorescent film is easily dried, and the adhesion density is lowered. On the contrary, when the content of the plasticizer is more than 50W / V%, the drying is not good, and thus a pattern is not formed.

In addition, the above-mentioned composition is used as it is when the red and blue fluorescent film is applied, but in the case of a rust fluorescent film, a binder may be added to increase the adhesion to the glass surface.

At this time, the binder is used in the United States DuPont Ludox AM 0.5-5% range.

The method of forming the fluorescent surface as the above composition is carried out as shown in FIG.

The composition is applied to the inner side of the face 2 to form the first photosensitive film 4. Subsequently, the green fluorescent film mask 6 is mounted on the face 2 and exposed. Since the exposed portion of the first photoresist film 4 has adhesiveness and insolubility in water, when the phosphor powder is sprayed at this time, a rust fluorescent film 8 is formed.

Since the content of the plasticizer in the composition is 20-50W / V%, the adhesion density of the phosphor is considerably high.

Subsequently, the over-dispersed phosphor is recovered by a suitable collecting means such as a vacuum aspirator, and washed with pure water to remove residual phosphor powder so that subsequent color residue does not occur.

Through the above process, the green fluorescent film pattern 8 ′ remains on the inner surface of the face 2. This is again treated with boric acid water so that the fluorescent pattern shrinks and sticks. In the present invention, boric acid water used a 2.5% solution. The red and blue fluorescent film patterns use the composition as it is, and form the same process as the formation of the green fluorescent film pattern.

An enlarged image of the fluorescent film pattern thus obtained is shown in FIG. 3.

FIG. 2 is an enlarged photograph of the fluorescent film pattern obtained by the conventional slurry coating method. As compared with the above FIG. 3 photograph, it can be seen that the stripe is coarse with the naked eye in FIG.

As described above, according to the present invention, since the fluorescent film pattern is remarkably ordered and clearly formed, it is advantageous to provide a color cathode ray tube of highly improved image quality.

Claims (3)

In the color cathode ray tube to form red, blue, and green fluorescent patterns, 10-50% of pure water, 5-30% of polyvinyl alcohol, 0.5-5% of potassium dichromate salt, 0.5-5% of diethylene glycol and 0.5 of ethylene glycol as a plasticizer -5%, 0.5-5% urea and 0.5-5% acetamide and 0.5-10% butanediol, 0.5-5% paraaldehyde and 0.5-5% dioxane, 0.5-5% surfactant, The photosensitive resin composition having the total content limited to 20-50W / V% is applied to the face inner surface of the color cathode ray tube and dried, and irradiated with ultraviolet rays through a fluorescent mask to expose only a predetermined portion, and then the phosphor powder on the face inner surface. A method for forming a fluorescent film of a color cathode ray tube, characterized in that the fluorescent film pattern formed by washing the inner surface of the face with pure water and shrinking-fixed by sputtering and recovering the excess phosphor powder by the collecting means. The method for forming a fluorescent film of a color cathode ray tube according to claim 1, wherein boric acid water is a 2.5-10% solution. The method for forming a fluorescent film of a color cathode ray tube according to claim 1, wherein the collecting means is a vacuum inhaler.

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