JPS5915324B2 - Manufacturing method of photosensitive resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a photoinsolubilizable photosensitive resin that is soluble in water or a water-containing organic solvent and exhibits high sensitivity.

5. Photosensitive resins are widely used as printing plate manufacturing materials, resists for photoetching, photomilling, etc., and as photosensitive vehicles for paints and printing inks.

Until now, photosensitive resins with photosensitive residues such as azide groups, cinnamoyl groups, and acryloyl o groups have been known, but in many cases, they need to be dissolved in an organic solvent to be used. be. If the solvent can be replaced with water, there will be major benefits such as lower prices, cleaner working environments, and easier wastewater treatment compared to using organic solvents.
Because of these advantages, there is a demand for the development of photosensitive resins that are soluble in water. The present inventor has already discovered that when a nitrogen-containing heterocycle having a styryl group is introduced into polyvinyl alcohol as a photosensitive group, although the rate of introduction is extremely low,
discovered a water-soluble photosensitive resin with the characteristic of exhibiting high sensitivity.
This photosensitive resin is used not only as a printing material for screen printing (Japanese Patent Application Laid-open No. 55-62446), but also for biocatalysts such as enzymes and chloroplasts. It is extremely useful as a fixed material.

The method for producing this photosensitive resin involves preparing an aqueous solution of polyvinyl alcohol or a mixed aqueous solution with an organic solvent.
It has been proposed to introduce a photosensitive group into this through a polymer reaction.

According to this method, the photosensitive resin is reprecipitated and purified in order to remove the acid used as a catalyst for this reaction or to remove the unreacted photosensitive material. However, such a process is complicated and not advantageous in terms of cost. Therefore, as a result of extensive research aimed at simplifying the purification of photosensitive resins, the present inventor found that
This is what led to this conclusion. That is, the present invention provides a general formula (1) (wherein R represents a hydrogen atom or a methoxy group, A represents any one of pyridinium, quinolinium, thiazolium, and benzthiazolium, and m is an integer from 1 to 6. When producing a polyvinyl alcohol-based photosensitive resin having a photosensitive structural unit represented by Generally, while remaining suspended in an aqueous solution? α River) (R, A, m, n in the formula have the same meanings as above). Provided is a method for producing a photosensitive resin, characterized in that the reaction is carried out under acidic conditions of O or less.

This general? The aldehyde in I) may be a functional group such as acetal that is easily converted into an aldehyde under acidic conditions.

Further, the nitrogen-containing heterocyclic compound having a styryl group in general formula 1) exhibits aromaticity. Therefore, examples of compounds represented by the general formula 0) include, but are not limited to.

These rings may be substituted with an alkyl group, an alkoxy group, or a hydroxyl group. The method for producing a photosensitive resin of the present invention is characterized in that polyvinyl alcohol is not dissolved in a solvent, but is reacted in a suspended state with an aldehyde compound represented by formula 1) in the presence of an acid catalyst.

Since the reaction products are still suspended without being dissolved, they can be easily separated, and furthermore, they can be easily separated from the acid and unreacted general formula (
The compound represented by 1) can be removed by washing. When water is used as a solvent, it is possible to take advantage of the property that completely saponified polyvinyl alcohol does not dissolve unless it is heated to a high temperature. In addition, since the number of photosensitive groups introduced in this reaction is small, the solubility of polyvinyl alcohol is not affected even after the reaction.
) A photosensitive resin into which a photosensitive group represented by (a) is also maintained in a suspended state unless the temperature is raised. Therefore, if the photosensitive resin thus obtained is isolated from the reaction solvent by centrifugation or filtration, and further washed with water, a water-containing organic solvent, or alcohol, a purified photosensitive resin can be obtained as is.
In order to reduce the solubility of polyvinyl alcohol in water as much as possible, chemicals that inhibit its dissolution, such as salts such as sodium sulfate, or water-soluble poor solvents such as dioxane and tetrahydrofuran, are converted into polymer acetals. It may be added during the reaction.

Polyvinyl alcohol used when water is used as a solvent has a saponification degree of 95% or more, and its polymerization degree is 3.
Approximately 00 to 3000 is desirable.

Polyvinyl alcohol is usually commercially available in granular or powdered form, so it is suspended in water as is. At this time, the amount of water is usually 2 to 20 times the weight of polyvinyl alcohol. In addition, the general concentration 1 used in the reaction
The aldehyde compound represented by ) is in a range of 0.1 to 10 mol %, preferably 0.5 to 5 mol %, based on the vinyl alcohol units of polyvinyl alcohol. An acid for promoting acetalization is added to a solution in which this polyvinyl alcohol is suspended and a compound represented by general 81) is dissolved. The acid used here may be inorganic or organic, but examples of inorganic acids include hydrochloric acid, sulfuric acid, phosphoric acid, perchloric acid, etc., and examples of organic acids include p-toluenesulfonic acid, methanesulfonic acid, acetic acid, Glycolic acid and the like are suitable. These acids are added so that the pH of the aqueous solution becomes 3 or less. By stirring or shaking this mixture, an acetalization reaction occurs and photosensitive residues are introduced into the polyvinyl alcohol.

The reaction temperature must be avoided at high temperatures to prevent dissolution of polyvinyl alcohol. Usually, a temperature range from room temperature to 50°C is appropriate. Further, the reaction time depends on the amount of added acid and the aldehyde compound represented by the general formula 0), but is preferably about 1 hour to 3 days. The progress of the reaction can be determined by taking out a portion of the reaction mixture, separating and purifying the suspended polyvinyl alcohol derivative by centrifugation or filtration, dissolving this in hot water to make an aqueous solution, and forming a film to improve the sensitivity. Just measure it. Alternatively, it can also be tracked by ultraviolet absorption spectrum. After the reaction is completed, the reaction mixture is filtered using gauze or the like as a filter medium, or the reactants are separated using a centrifuge.

The product is purified by washing it with water, a water-containing organic solvent, or alcohol, and further washing with weak alkaline water, such as a dilute solution of ammonia, to completely remove the catalyst acid. In this way, a photosensitive resin having the general structure 1) can be produced. The product may be stored as is, suspended in water, or dried and stored. However, since the product is sufficiently swollen with water during the reaction and can be easily dissolved in hot water or a water-containing organic solvent, it is preferable to suspend the product in water. Alternatively, it may be dissolved in hot water and stored as an aqueous solution. in this way,
According to the present invention, general? ) A photoinsoluble resin into which a photosensitive residue represented by the following formula is introduced can be easily produced.

In particular, since unreacted substances and catalytic acids can be removed extremely easily, high-purity photosensitive resins can be produced in large quantities. By taking advantage of these characteristics, it is suitable for entrapping and immobilizing biocatalysts such as enzymes, organelles, and bacterial cells, in addition to printing materials and resist materials. Alternatively, it can be used as a durable sizing agent for textile products such as cloth foil. Next, the present invention will be explained in more detail with reference to Examples.

Example 1 1-Methyl-4-(P-formylstyryl)pyridinium methosulfate 228W9 was dissolved in 15 cd of water, and completely saponified polyvinyl alcohol with a degree of polymerization of 2000 was added to the solution.
0t was suspended and gently stirred at room temperature for one day.

The reaction product was collected by filtration in a dark place through 300 mesh polyester gauze, and the filtrate was washed repeatedly with water to make it neutral. This reaction product was mixed with 30 cr of water again.
When suspended in i1 and heated and stirred at 90°C, a transparent pale yellow aqueous solution is obtained. When this resin liquid was applied to an aluminum plate and the sensitivity was measured using a step tablet, it was 6% by weight.
The sensitivity was 10 times higher than that of polyvinyl alcohol containing ammonium dichromate salt. Examples 2 and 3 In Example 1, fully saponified polyvinyl alcohol was made to have a degree of polymerization of 500 and 1400, and was isolated and purified under the same conditions. The value was about 4 times higher.

Examples 4 to 10 Completely saponified polyvinyl alcohol with a degree of polymerization of 1100 is suspended in water, and compounds 1, 2, 4,
5, 6, 7, and 8 were added in the amounts shown in Table 1, and the mixture was stirred at room temperature for 2 days.

The product was separated and washed in the same manner as in Example 1. Table 1 shows the results of dissolving the resin in hot water to make an aqueous resin solution, coating this on an aluminum plate, and measuring the sensitivity. Compounds 1 and 5
In the resin obtained from the method, the hydrogen atom bonded to the nitrogen atom of the photosensitive group is released and becomes a free base, so immediately before the sensitivity measurement, an acid was added and coated on an aluminum plate. Example 11 3 tons of completely saponified polyvinyl alcohol with a degree of polymerization of 2000
was suspended in 30 crA of water containing 3 t of phosphoric acid, and 314 η of dimethyl acetal of compound 12 was dissolved therein to obtain 4
It was shaken at 0°C for 3 days.

Claims (1)

[Claims] 1 General formula ▲ Numerical formula, chemical formula, table, etc. , m is an integer from 1 to 6, and n is 0 or 1). When producing a polyvinyl alcohol-based photosensitive resin having a photosensitive structural unit represented by , general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (R, A, m, n in the formula have the same meanings as above) An aldehyde compound or its precursor acetal compound is heated to a pH of 3.0 or less. A method for producing a photosensitive resin characterized by reaction under acidic conditions.