JP2001142231A - Stripping agent for photoresist used in production of shadow mask - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new stripping agent for a photoresist used in the production of a shadow mask for a color cathode-ray tube. SOLUTION: The stripping agent comprises an aqueous solution containing at least one selected from the group comprising ether, ester and ether ester derivatives of a polyol, an alkali metal hydroxide and a chelate compound. Preferably the stripping agent further contains a polyol.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a shadow mask for a color cathode ray tube by photolithography, and more particularly to an improved stripping agent used for stripping a resist after etching.

[0002]

2. Description of the Related Art When manufacturing a shadow mask for a color cathode ray tube, a metal material to be used as a shadow mask is subjected to a pretreatment such as degreasing and washing, and then, for example, milk caseinate or polyvinyl alcohol. After applying a photosensitive liquid comprising a colloidal substance of the above and ammonium dichromate as a synthesizer, forming a photosensitive film, exposing using a desired pattern, developing and removing unexposed portions, for example, The material to be processed in the unexposed portion is etched and drilled with an etching solution containing iron as a main component, and a hole serving as an electron beam passage hole is formed. Finally, a method is used in which the photoresist, which is an exposed photosensitive film remaining on the material to be processed, is peeled off using a peeling agent such as an aqueous solution of caustic soda.

[0003] In particular, if the photoresist remains on the material to be processed in this stripping step, it may cause molding defects in the subsequent steps, and thus a strong stripping agent having a stripping action is required.

For this purpose, for example, Japanese Patent Application Laid-Open No. 57-202
No. 540 describes a method of adding a dihydric alcohol represented by propylene glycol or a derivative thereof to caustic soda as a photoresist stripping agent.
JP-A-2-273436 describes a method of adding a chelating agent to caustic soda as an improved release agent used for manufacturing a shadow mask.

However, in any of the above aqueous solutions,
Although it exhibits a certain stripping effect, there is a problem that the effect is insufficient for the desired complete stripping of the photoresist. In particular, there remains a problem in the releasability of an acrylic ultraviolet cured film applied in an etching step described later. Of course, even with these release agents, release is possible if the processing conditions are severe, such as increasing the release time or number of treatments, increasing the temperature, or increasing the pressure at which the release agent is sprayed onto the material to be processed. However, in order to worsen productivity and cost, further improvement in peelability is required.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a method of manufacturing a shadow mask for a color cathode-ray tube manufactured by a photoengraving method. The purpose of this is to peel off.

[0007]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, as a photoresist stripping agent used for manufacturing a shadow mask for a color cathode ray tube, an ether derivative of a polyhydric alcohol, It has been found that a release agent comprising an aqueous solution containing at least one selected from the group consisting of ester derivatives and ether ester derivatives, an alkali metal hydroxide, and a chelate compound can be suitable for the purpose. On the basis of,
The present invention has been made.

That is, the present invention relates to a photoresist stripping agent used for producing a shadow mask for a color CRT, at least one selected from the group consisting of ether derivatives, ester derivatives and ether ester derivatives of polyhydric alcohols, and an alkali metal. The present invention relates to a release agent comprising an aqueous solution containing a hydroxide and a chelate compound. The present invention also relates to the above-mentioned release agent, which further contains a polyhydric alcohol in order to increase the release effect.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail.

The alkali metal hydroxide added to the stripping agent of the present invention is specifically sodium hydroxide, potassium hydroxide, or the like.

The content thereof is preferably 10 to 40% by weight, more preferably 15 to 40% by weight, based on the whole release agent.
３０30% by weight. If the content of the alkali metal hydroxide is less than 10% by weight, the peeling effect tends to be reduced, and if it is more than 40% by weight, no particular improvement in the peeling effect tends to be seen. Rather, there is a tendency that the material to be processed is liable to be chemically damaged called alkali burn.

It is considered that the effect of this component is mainly that the photoresist is peeled off from the material to be processed and dissolved.

The chelate compound added to the release agent of the present invention is preferably a carboxylic acid compound having a hydroxyl group. Specifically, gluconic acid, sodium gluconate, tartaric acid, sodium tartrate, citric acid, sodium citrate, etc., and other metal salts such as potassium salts are also preferably used.

Further, the content thereof is preferably 1 to 10% by weight based on the whole release agent. If less than 1% by weight,
The peeling effect tends to decrease, and 10% by weight
At most, no particular improvement in the peeling effect tends to be observed, which is uneconomical.

It is considered that the effect of this component is that chromium of ammonium dichromate, which is mainly added to the photosensitive solution as a synthesizer, is removed as a chelate compound.

The polyhydric alcohol ether derivative, ester derivative and ether ester derivative added to the release agent of the present invention may be a mono- or di-alkylene glycol mono- or di-alkyl ether, a mono- or di-alkylene glycol mono- or di-alkyl ester, a mono- or di-alkyl ester. Alkylene glycol alkyl ether esters and the like are preferred.

Specifically, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether,
Ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol monoacetate, ethylene glycol diacetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol monoacetate, diethylene glycol monoethyl ether acetate, Propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol dimethyl ether, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl Chromatography ether acetate, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether. Further, glycerin ether derivatives, ester derivatives and ether ester derivatives can also be used. This component may be used alone or in combination of two or more.

The content thereof is preferably 0.05 to 10% by weight, more preferably 0.1 to 5% by weight, based on the whole release agent. This component can show a remarkable effect even in the range of 0.05 to 1% by weight, which is a smaller usage amount than the usage amount of the alkali metal hydroxide and the chelate compound. If the content is less than 0.05% by weight, a remarkable effect of adding this component tends to not be obtained, and
When the content of this component is 10% by weight or less, a sufficient peeling effect is obtained, and further addition tends to be uneconomical.

The function of this component is to reduce the adhesion between the photoresist and the material to be processed when peeling the photoresist from the material to be processed, and to promote the dissolution of the photoresist by the alkali metal hydroxide. It is thought that there is.

Further, a polyhydric alcohol can be added to the release agent of the present invention in order to increase the release effect. The polyhydric alcohol added to the release agent of the present invention is preferably a mono- or dialkylene glycol. Specifically, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol and the like are included. Glycerin and the like can also be used. This component may be used alone or in combination of two or more.

The content thereof is preferably 0.05 to 10% by weight, more preferably 0.1 to 5% by weight, based on the whole release agent. If the amount is less than 0.05% by weight, the remarkable effect of adding this component tends not to be seen. Also, if the amount of this component is 10% by weight or less, there is a sufficient effect of accelerating the peeling. It tends to be economic.

It is considered that the effect of this component is to cause the photoresist to swell and facilitate peeling from the work material.

The release agent of the present invention comprises at least one selected from the group consisting of the above-mentioned three components, ie, a polyhydric alcohol ether derivative, an ester derivative and an ether ester derivative; an alkali metal hydroxide; And, more preferably, by the synergistic effect of the combination of the four components to which the polyhydric alcohol is added, a conventional caustic soda-only stripping agent, a mixed stripping agent of caustic soda and a chelating agent, or a mixture of caustic soda and a polyhydric alcohol or a derivative thereof. A remarkably strong photoresist stripping action not found in the mixed stripping agent or the like is recognized.

Further, the release agent of the present invention is applied to an acrylic UV-cured film (commonly known as varnish; generally, a prepolymer such as oligoester acrylate or urethane acrylate),
It is composed of a monomer such as hydroxyethyl acrylate and a photopolymerization initiator. It is also characterized in that the releasability of ()) is extremely excellent as compared with conventional release agents.

More specifically, the above-described etching process is actually performed by “two-stage etching”. First, one side of the processed material from which the unexposed portions of the photosensitive film have been removed is half-etched with an etching solution to a predetermined depth (a hole is formed to about half of the material thickness), and then acrylic ultraviolet curing called varnish is performed on the surface. Form a film. This is to protect the already etched surface from splashing of the etchant or the like when etching the other surface. Then, the other side which has not been etched is etched to form an electron beam passage hole. Finally, the varnish and photoresist are stripped together with the same stripping agent.

This varnish is more difficult to peel off than a photoresist made of casein or the like, and the varnish remains often a problem. Therefore, the excellent varnish release property is an industrially useful property, and it can be said that the release agent of the present invention is a very important advantage as compared with the conventional release agent.

The release agent of the present invention can be used in the production of a shadow mask for a color cathode ray tube in exactly the same manner as the conventional photoresist release agent.
That is, after a material to be processed such as an iron-nickel alloy serving as a shadow mask is subjected to a pretreatment such as degreasing and washing, a photosensitive material including, for example, milk caseinate as a colloidal substance and ammonium bichromate as a synthesizer is used. The liquid is applied and dried to form a photosensitive film on both surfaces of the material to be processed. Then, a desired pattern original corresponding to the electron beam passage hole of the shadow mask is brought into close contact with both sides, exposed and printed, and then the photosensitive film is sprayed with hot water or the like and developed to remove unexposed portions. As a result, a photoresist, which is an exposed photosensitive film and has an opening at a portion to be an electron beam passage hole, is formed on both surfaces. Then, the corrosion resistance of the photoresist is increased by heat treatment, and then, for example, an etching solution containing ferric chloride as a main component is sprayed one by one using the above-described two-stage etching method, and finally etched on both surfaces. To form a hole that becomes an electron beam passage hole.

Finally, the photoresist or varnish remaining on the material to be processed is removed by applying the release agent of the present invention to a predetermined temperature, for example, 80 ° C.
Spray completely at about ° C. Then wash,
Dry to form a shadow mask.

Further, even when the colloidal substance in the above-mentioned photosensitive solution is made of polyvinyl alcohol, the stripping agent of the present invention is sprayed on the photoresist and the varnish remaining after etching under the same conditions. Then, the varnish can be completely removed.

[0030]

Next, the present invention will be described more specifically with reference to examples and comparative examples.

An amber steel plate (iron-nickel 36% alloy) having a thickness of about 0.2 mm and made of the same material as that used for a shadow mask for a color cathode ray tube is degreased and washed, and then milk alkali alkali caseinate and ammonium bichromate are used. After forming a photosensitive film (thickness: about 10 μm) by applying a photosensitive solution consisting of the following, exposure treatment and heat treatment are performed, and a casein film peeling test steel plate (referred to as peeling test steel plate A in Table 1; Side 10
cm).

Next, a varnish-casein film peeling test steel sheet having an acrylic UV-cured film called a varnish formed on the casein film peeling test steel sheet A (referred to as a peeling test steel sheet B in Table 1 with the same dimensions as above). (Casein film thickness: about 10 μm, varnish film thickness: about 30 μm).

The peel test was performed as follows. Stainless steel container filled with a release agent aqueous solution (height 12 cm, width 12 c
m, thickness 2 cm) in a standing state in an oil bath with a controlled temperature, and after the release agent temperature inside the container reaches a predetermined test temperature, a release test steel plate is placed on the release agent. The steel sheet was pulled out of the release agent after 40 seconds in the case of the test steel sheet A, and after 80 seconds in the case of the test steel sheet B, and sufficiently washed with running water. During the immersion, a stainless steel container was covered to avoid a temperature change. Then, the peeled state of the photoresist and the varnish on the test steel plate was inspected visually and by a microscope.

<Examples 1 to 14> Examples 1 to 14 in Table 1
The peel test was carried out on the two types of peel test steel plates A and B described above, while changing the components and concentrations of the release agent of the present invention (the remainder other than the indicated components was water), and the temperature, respectively. Part of the result.

After the test, visual inspection and microscopic inspection of the steel sheet for peel test revealed that the photoresist was completely peeled in each case.

<Comparative Examples 1 to 5> Comparative Examples 1 to 5 in Table 1
This is a part of the results of a peel test performed in the same manner as in the examples, while changing the components and concentrations of the release agents shown in the table (the remainder other than the indicated components is water), and the temperature, respectively.

After the test, a similar test was conducted on the steel sheet for peel test. In each case, a part of the photoresist remained, and the steel sheet was not completely peeled.

[0038]

[Table 1]

As is clear from Table 1, the conventional release agent is:
While the stripping action of the photoresist is insufficient under various processing conditions, the stripping agent of the present invention exhibits a very excellent stripping action.

[0040]

The stripping agent of the present invention is extremely useful as a stripping agent, since it has a strong stripping effect when used for stripping a photoresist in the production of a shadow mask for a color cathode ray tube.

Continued on the front page (72) Inventor Kenji Akagishi 2767-11, Niihama, Shima, Kojima, Kurashiki-shi, Okayama Asahi Kasei Kogyo Co., Ltd. In-house F term (reference) 2H095 AA02 2H096 AA27 BA05 BA07 EA02 GA08 LA03 5C027 HH11

Claims (7)

[Claims] 1. An aqueous solution containing at least one selected from the group consisting of ether derivatives, ester derivatives and ether ester derivatives of polyhydric alcohols, an alkali metal hydroxide, and a chelate compound. Photoresist stripper used for shadow mask production. 2. The content of at least one selected from the group consisting of polyhydric alcohol ether derivatives, ester derivatives and ether ester derivatives is 0.05 to 10% by weight, and the content of alkali metal hydroxide is 10 to 10% by weight. The photoresist stripping agent according to claim 1, wherein the content of the chelating compound is 1 to 10% by weight. 3. The content of at least one selected from the group consisting of ether derivatives, ester derivatives and ether ester derivatives of polyhydric alcohols is 0.1 to 5% by weight, and the content of alkali metal hydroxide is 15 to 5%. 3. The photoresist stripping agent according to claim 1, wherein the content of the chelate compound is 1 to 10% by weight. 4. The release agent for a photoresist used in manufacturing a shadow mask according to claim 1, further comprising a polyhydric alcohol. 5. The polyhydric alcohol content is 0.05 to 1
5. The release agent for a photoresist used for manufacturing a shadow mask according to claim 4, wherein the amount is 0% by weight. 6. The photoresist stripping agent according to claim 4, wherein the content of the polyhydric alcohol is 0.1 to 5% by weight. 7. The photoresist used for manufacturing a shadow mask according to claim 1, wherein the shadow mask is used for removing an acrylic ultraviolet cured film or an acrylic ultraviolet cured film and a photoresist in the shadow mask manufacturing process. Release agent.