JPS60247238A - Photosensitive composition - Google Patents

Abstract

PURPOSE:To form efficiently the image of a coated fluorescent powder layer faithful to an optical image, especially a high quality fluorescent screen on the inside of a color cathode-ray tube by adding KBr and/or NaBr together with a specified diazonium salt. CONSTITUTION:This photosensitive composition contains 1mol aromatic diazonium salt such as double salt of p-diazo-N,N-dimethylaniline zinc chloride and 0.5-1.5mol in total of KBr and/or NaBr. Said double salt may be only used as the photosensitive composition. The photosensitive composition further contains a water soluble org. polymer such as gum arabic, PVAL or polyacrylamide by about 5-50wt% of the amount of the diazonium salt. A photosensitive film of the photosensitive composition absorbs well ultraviolet light, and the diazonium salt in the film photodegrades at a high speed, so an optical sticking film can be efficiently formed in a short time. Accordingly, an image of a coated flurorescent powder layer faithful to an optical image is easily formed, and a high quality fluorescent screen can be efficiently formed on the inside of a color cathode- ray tube.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a photosensitive composition used for forming a powder coating layer image according to an optical image, and particularly for use in the production of fluorescent surfaces of color cathode ray tubes. The present invention relates to a highly sensitive photosensitive composition for forming a photoadhesive film.

[Background of the invention]

On the inner surface of the screen part (face plate) of a color cathode ray tube, there are three types of phosphors that emit red, green, and blue light in the form of dots or stripes.
r4pe). The conventional method of forming this phosphor coating layer is.

(1) First, a mixture of a first color phosphor and a photosensitive resin is applied to the inner surface of the face plate.

Dry to form a coating film.

(2) Next, apply a shadow mask (Sha
Ultraviolet rays are irradiated through the holes in the dow mask.

The ultraviolet irradiation position at this time corresponds to the position where the electron beam for causing the phosphor to emit light strikes, that is, the position where the phosphor is to be fixed. The photosensitive resin in the area exposed to this ultraviolet ray irradiation becomes insolubilized, and thereby the coating film in that area becomes insolubilized.

(3) Next, the coating film is washed with a solvent, leaving only the insolubilized portion remaining on the inner surface of the face plate, and the other portions being dissolved and removed.

(4) Next, a mixture of a second color phosphor and a photosensitive resin is applied, and a second color phosphor coating film is formed using the same method as for forming the first color coating film described above.

Furthermore, a third color phosphor coating film is formed by the same method to complete three types of phosphor coating layers on the face plate surface of the color cathode ray tube.

As is clear from the above explanation, the process of manufacturing the fluorescent surface of color cathode ray tubes is complex and requires repeated wet coating, washing, and drying many times.

Simplification of the process is highly desirable.

To this end, the present inventors previously proposed Japanese Patent Application Laid-Open No. 126861/1986 as a method for forming a fluorescent surface of a color cathode ray tube using a process that is significantly simpler than that of the prior art.

In this method, (1) a photosensitive composition containing an aromatic diazonium salt that is decomposed by light irradiation, the resulting substance is hygroscopic, and becomes sticky by absorbing moisture in the atmosphere, is transferred to a color cathode ray tube. (2) The thin layer is exposed to light of a predetermined wavelength in a pattern to create stickiness in the exposed area; (3) After exposure, Powder particles of a specified phosphor are brought into contact with the thin layer, and the thin layer becomes sticky.

It is characterized by receiving (adhering to) powder particles of a predetermined phosphor. According to this method, the application of the second and third color phosphors is as follows.

It is only necessary to repeat the exposure to light of a predetermined wavelength and the contact reception of the phosphor powder particles, and once a coating film that becomes sticky due to exposure is formed, it is then possible to create any number of phosphor patterns (P It is also possible to form it with the following. However, the photosensitivity of the photosensitive composition used in this method is slightly lower than that of conventionally used photosensitive resins.

This method has the disadvantage that it takes some time to complete a given phosphor coating layer, which reduces production efficiency accordingly.

[Purpose of the invention]

The object of the present invention is to solve the above-mentioned drawbacks of the prior art and to provide a method for forming a powder coated layer image of a phosphor according to an optical image on the phosphor surface of a color cathode ray tube, etc., in a short time and efficiently. The present invention provides a photosensitive composition that produces a highly sensitive photoadhesive film.

[Summary of the invention]

The highly sensitive photosensitive composition (hereinafter abbreviated as high 4-sensitivity composition) according to the present invention is represented by the following general formula. Per 1 mole of p-diazo-N,N-dimethylaniline zinc chloride double salt, potassium bromide and sodium bromide are contained in a total amount of 0.5 to 1.5 moles of one or more of the two. .

A photoresist film formed by applying a solution containing the highly sensitive composition of the present invention nine times is covered with fine crystal grains of a diazonium salt compound. The fine crystals of this diazonium salt compound are represented by the original general formula (1). It was not p-diazo-N,N-dimethylaniline zinc chloride double salt, but had a different double salt structure. It is thought that it has changed to a diazonium salt represented by the following general formula (U).

It is thought that the fine crystals of the diazonium salt represented by the general formula (IT) have the property of absorbing ultraviolet light well and being easily photodecomposed.

Regarding the diazonium salt represented by general formula (1) in the present invention. The amount of carlum bromide (KBr) or sodium bromide (NaBr) and its mixture added is based on 1 mole of the above diazonium salt.

0.5 to 1.5 mol is preferable, and less than 0.5 mol,
The effect of sensitizing the photosensitive film is small and the exposure time becomes long.

Furthermore, if the amount of KBr or NaBr added exceeds 1.5 mol, excessive KBr or NaBr will precipitate on the photoresist film, making the photoadhesive film cloudy and having poor light transmittance, which is not preferable. The most preferred range is.

For diazonium salts represented by general formula (I).

is about the same mole.

In addition, as a highly sensitive composition in the present invention, the general formula (1
) In addition to the diazonium salts represented by

Other aromatic diazonium salts, such as aromatic diazonium borohydrofluoride, aromatic diazonium sulfate,
Aromatic diazonium sulfonate.

Also, one or more aromatic diazonium/zinc chloride double salts may be contained in a total amount of 5 to 50% by weight based on the diazonium salt of general formula (I).

In this case, if the amount of other aromatic diazonium salts added is less than 5% by weight, the effect of improving sensitivity (sensitization) will be small, and if it exceeds 50% by weight, the crystallinity of the photosensitive film will deteriorate, and if the amount of other aromatic diazonium salts added is produces a photo-adhesive film in an amorphous state, and the film in this state has the property of slightly adhering powder (phosphor) even when unexposed, which is undesirable, and the more preferable range is 10 to 20% by weight. .

Furthermore, in the present invention, in order to adjust the viscosity of the solution of the highly sensitive composition and improve the coatability of the photosensitive film, water-soluble polymer compounds 9 such as gum arabic, polyvinyl alcohol, polyacrylamide, poly(N -vinylpyrrolidone) and acrylamide-diacetone acrylamide copolymer may be added in a total amount of 5 to 50% by weight based on the diazonium salt represented by the general formula (1). In this case, if the amount of the water-soluble polymer compound added is less than 5% by weight, no improvement in the coatability of the photosensitive film can be expected, and if it exceeds 50% by weight, the crystallinity of the film will deteriorate, which is undesirable. , the more preferable range is 5 to 20% by weight.
It is.

FIG. 1 shows the ultraviolet absorption spectrum of a photoadhesive film formed on a glass substrate using the highly sensitive composition of the present invention. In the figure, the horizontal axis is the wavelength of ultraviolet light (nm), and the vertical axis is the optical density (log (irradiation light intensity/light intensity passing through the film)).
represents. Curve 1 in Figure 1 is.

Glass substrate only 9 Curve 2 is the ultraviolet absorption spectrum of only the diazonium salt represented by general formula (1). % of KBr and 9 curve 4 contains two diazonium salts of the general formula (1) according to the present invention and about 25% by weight of other aromatic diazonium salts (5-diazo-2 chloride). -methoxy-N,
N-dimethylaniline zinc chloride double salt) was added. When about 30% by weight of KBr is added to the mixed diazonium salt and the diazonium salt of general formula (1) above, an ultraviolet absorption spectrum of 8- is shown. As is clear from FIG. 1, the optical adhesive film according to the present invention to which KBr is added exhibits a very high absorption rate of ultraviolet light.

This indicates that it is easily photodegradable.

Generally, diazonium salts absorb ultraviolet light, mainly light having a wavelength of 365 nm, and undergo photodecomposition. therefore.

By measuring the rate of decrease in light absorption at this wavelength,
Measure the speed of photodecomposition of diazonium salts.

You can know the degree of sensitivity improvement (sensitization). FIG. 2 is a graph showing the speed of photodecomposition of a photosensitive film formed using the high-sensitivity composition of the present invention, and the horizontal axis is l'! at the time of exposure. ! 1(
The vertical axis shows the light transmittance (%) at 365 nm. Curve 5 in FIG.

In the case of only the diazonium salt represented by general formula (1), 2 curve 6 is 9. In the case of adding about 30% by weight of KBr to the diazonium salt of general formula (1) according to the present invention, 2 curve 7 is 9 curve 6 About 30 N a Br in place of KBrO
9 Curve 8 is the weight percent added.

1 shows the relationship between exposure time (minutes) and light transmittance (%) in the case of the component of curve 4 in FIG. 1, that is, a mixed diazonium salt.

As is clear from FIG. 2, 9 KBr or Na of the present invention
Added Br. It can be seen that the photosensitive film containing the diazonium salt represented by the general formula (1) has a higher light transmittance faster than the photosensitive film without the addition of the diazonium salt, and the diazonium salt is decomposed faster.

In addition, other aromatic diazonium salts (in the case of 5-diazo chloride,
As shown in curve 4 in Figure 1, the absorption wavelength width of ultraviolet light becomes wider, and as shown in curve 8 in Figure 2, the decomposition rate of the diazonium salt becomes faster than in the case of a single diazonium salt. This shows that there is a sensitizing effect.

2. The present inventors have confirmed through experiments that other bromide salts other than KBr and NaBr (L i B r , N H4 B r, etc.) are not suitable for the Figure 1-shaped powder coating film. There is.

[Embodiments of the invention]

Next, one embodiment of the present invention will be given and explained in more detail.

(Example 1) An aqueous solution having the following composition 1 was applied onto a glass substrate by a spin coating method, and dried by infrared heating to a thickness of about 0.0 mm.
Three photoresist thin layers were formed.

The ultraviolet absorption spectrum of this thin photoresist film is curve 3 in Figure 1.
Shown below. As is clear from the figure, the optical density is much higher than that without adding KBr.

11- It is well established that it is easily photodegraded.

(Example 2) In place of the photosensitive composition liquid of Composition 1 in Example 1, an aqueous solution of Composition 2 below was used, and under almost the same conditions as Example 1,
A thin photoresist layer having a thickness of about 0.3 mm was formed.

The photodecomposition rate of this thin photoresist layer is shown by curve 7 in FIG.

It is clear from the figure that the light transmittance increases faster than the photoresist film to which no NaBr is added, indicating that the diazonium salt is decomposed faster.

-12 = (Example 3) Instead of the photosensitive composition liquid of composition 1 of Example 1, the following composition 3 was used.
A thin photoresist layer was formed using the same aqueous solution as in Example 1.

As is clear from curve 4 in Figure 1, by adding an appropriate amount of another aromatic cyazonium salt φ to the diazonium salt of formula (1), the absorption wavelength width of ultraviolet light of the photosensitive film becomes wider, and This is because the light transmittance increases rapidly, as shown by curve 8 in FIG.

It can be seen that it is easier to photodecompose and the rate of photodecomposition is faster than in the case of a single diazonium salt, and that it has the effect of sensitizing the photosensitive film.

The reason why the light transmittance of some photoresist films in FIG. 2 decreases at the initial stage of exposure is thought to be because the undecomposed crystalline diazonium salt temporarily becomes amorphous.

Furthermore, for each photoresist film in FIG. 2, the light transmittance at zero exposure time is used as a reference.

When light was irradiated for an exposure time corresponding to a 10% increase in light transmittance, and the resulting photoadhesive film received (adhered) a phosphor, it was found that approximately the same amount of phosphor was covered. I was able to get him to wear it.

In addition, using the high-sensitivity composition of Composition 1 shown in Example 1 above, a coating film was prepared according to the method for forming a graphic powder coating layer proposed by the present inventors in JP-A-53-126861. By performing exposure, phosphor deposition, and excess phosphor removal operations for blue, green, and red phosphors, we were able to fabricate a phosphor surface for a color cathode ray tube with excellent performance. Ta.

〔Effect of the invention〕

As explained in detail above, 9 General formula (1) according to the present invention
A photoresist film formed by a high-sensitivity composition containing a predetermined amount of KBr or NaBr in a diazonium salt represented by the formula or a mixed diazonium salt obtained by adding an appropriate amount of other diazonium salts is capable of absorbing ultraviolet light. absorbs well,
Moreover, since the photodecomposition rate of the diazonium salt in the photosensitive film is high, a photoadhesive film can be formed efficiently in a short time.

It is easy to form a fluorescent powder coated layer image according to an optical image, and it is possible to manufacture a high-quality fluorescent surface on the inner surface of a color cathode ray tube with high efficiency, thereby improving productivity. The practical effect is remarkable.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the 15-ultraviolet absorption spectrum of a photoresist made of the highly sensitive composition of the present invention, and FIG. 2 is a graph showing the photodecomposition rate of the photoresist made of the highly sensitive composition of the present invention. . Representative Patent Attorney Junnosuke Nakamura 16-

Claims (1)

[Scope of Claims] 1. In a photosensitive composition containing an aromatic diazonium salt, p-diazo-N chloride is used as the aromatic diazonium salt.
, N-dimethylaniline zinc chloride double salt, and further contains one or both of potassium bromide and sodium bromide. 2. In a photosensitive composition containing an aromatic diazonium salt, one or two of potassium bromide and sodium bromide are added at 9% per mol of p-diazo-N,N-dimethylaniline zinc chloride double salt. 2. The photosensitive composition according to claim 1, wherein the photosensitive composition contains 0.5 to 1.5 moles in total. 3. In the photosensitive composition containing an aromatic diazonium salt, the aromatic diazonium salt is p-diazo-N chloride,
2. The photosensitive composition according to claim 1, comprising only N-dimethylaniline zinc chloride double salt. 4. A water-soluble organic polymer compound in a photosensitive composition containing an aromatic diazonium salt. One or more of gum arabic, polyvinyl alcohol, polyacrylamide, poly(N-vinylpyrrolidone), and acrylamide-diacetone acrylamide copolymer, in a total amount of 5 to 50% based on the aromatic diazonium salt. %
The photosensitive composition according to claim 1, characterized in that it contains: