JPH10198047A - Developing solution for photosensitive planographic printing plate and its preparation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the foaming of a developer, to improve preservability and to prevent stain due to printing and the deterioration of suitability to writing with a ball-point pen, a mark made by patching, etc., by incorporating an org. acid into a developing soln. for a photosensitive planographic printing plate. SOLUTION: An org. acid is incorporated into a developing soln. for a photosensitive planographic printing plate contg. a higher fatty acid as an additive. The developing soln. means a developer or a replenisher soln. for development. A known aq. alkali soln. may be used as the developer. The alkali is, e.g. an inorg. alkali agent such as sodium silicate, potassium silicate, ammonium silicate, sodium sec. phosphate, potassium sec. phosphate, ammonium sec. phosphate, sodium hydrogencarbonate, potassium hydrogencarbonate, ammonium hydrogencarbonate, sodium borate, potassium borate, ammonium borate, sodium hydroxide, potassium hydroxide ammonium hydroxide or lithium hydroxide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing solution for a photosensitive lithographic printing plate and a method for preparing the same. More specifically, the present invention relates to a ball-point pen having little foaming property of a developing solution, excellent storage stability, and producing no printing stains. The present invention relates to a developing solution for a photosensitive lithographic printing plate which does not degrade the suitability and sticking marks, etc., and a method for preparing the same.

[0002]

2. Description of the Related Art In order to obtain a photosensitive printing plate free from printing stains, it is often practiced to add a higher fatty acid or a betaine-based amphoteric surfactant to a developer.

However, higher fatty acids and betaine-based amphoteric surfactants have a property that they are difficult to dissolve in the main components of a developing solution such as an alkali metal silicate. Insolubles were easily formed, which was a limitation in use.

As a method for dissolving higher fatty acids, there is a method using an organic solvent such as ethanol. In this case, when a developer is stored for a long period of time, the gradation of a lithographic printing plate which is separated into two layers or developed is soft. And there is a problem that the suitability of the ballpoint pen may be adversely affected.

[0005] In the case of betaine-based amphoteric surfactants, there is a problem that the foaming property of the developing solution and the sticking mark of the lithographic printing plate are deteriorated, which has been a limitation in using these. As a countermeasure for these, there is a method of using an organic solvent such as propylene glycol in combination, but there is a problem that the initial purpose is to deteriorate the printing stain.

[0006]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to reduce printing stains, and to prevent separation and precipitation even when a developer is stored for a long period of time. An object of the present invention is to provide a developing solution for a photosensitive lithographic printing plate having no foaming property, suitability for a developed photosensitive lithographic printing plate with a ballpoint pen, and deterioration of a sticking mark, and a method for preparing the same.

[0007]

The above object of the present invention is achieved by the following means.

[0008] A photosensitive lithographic printing plate developing solution containing a higher fatty acid as an additive, wherein the developing solution contains an organic acid.

In the step of preparing the photosensitive lithographic printing plate developing solution, a higher fatty acid is mixed and dissolved in an organic acid and then mixed with an alkali metal silicate. Liquid preparation method.

In a photosensitive lithographic printing plate developer containing a betaine-based amphoteric surfactant as an additive,
A developer for a photosensitive lithographic printing plate comprising an organic acid.

Hereinafter, the present invention will be described specifically.

In the present invention, the suitability for a ball-point pen is a function indicating the degree to which the photosensitive layer is lost during development and the grain is exposed even though the part marked with the ball-point pen is an unexposed part. The smaller the exposure and the smaller the exposure, the better the suitability for a ballpoint pen.

The higher fatty acid in the present invention has 6 carbon atoms.
-20, preferably 10-14, particularly preferably 12, for example, lauric acid and the like. The concentration in the photosensitive lithographic printing plate developer is preferably from 1 to 1000 ppm,
200 ppm is particularly preferred.

The developing solution in the present invention means a developing solution or a developing replenisher.

The betaine amphoteric surfactant in the present invention preferably has the following structure.

[0016] ^{_{R (CH 3) 2 N +}} CH 2 COO - such betaine amphoteric surfactant, for example those commercially available as Amogen K (Dai-ichi Kogyo Seiyaku Co., Ltd.).

The organic acid in the present invention has 1 to 4 carbon atoms.
Or a carboxylic acid having an aromatic ring having 7 to 20 carbon atoms, wherein the concentration in a developing solution for a photosensitive lithographic printing plate is from 10 to 50,000 ppm.

As the developer used in the present invention, conventionally known aqueous alkali solutions can be used. For example, sodium silicate, potassium, ammonium,
Sodium diphosphate, potassium, ammonium, sodium bicarbonate, potassium, ammonium, sodium carbonate, potassium, ammonium, sodium bicarbonate, potassium, ammonium, sodium borate, potassium, ammonium, water Sodium oxide,
Inorganic alkaline agents such as potassium, ammonium, and lithium. Also, monomethylamine, dimethylamine, trimethylamine, monoethylamine,
Organic alkaline agents such as diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, ethyleneimine, ethylenediamine and pyridine are also used. Can be These alkaline agents are used alone or in combination of two or more.

If necessary, other additives can be added to the developer.

As the developing solution and the developing replenisher of the present invention, an alkali metal silicate, for example, an aqueous solution of sodium silicate or potassium silicate is preferably used. In that case, the weight concentration of SiO ₂ is 1.0 to 4.0% by weight and the molar ratio of SiO ₂ / alkali metal is 0.1%.
15 to 0.75.

The developing solution and the developing replenisher of the present invention can be applied to the processing of a positive photosensitive lithographic printing plate.
For example, JP-A-6-230582 and JP-A-7-114178
No. 8-171215, Japanese Patent Application No. 7-2218986
And positive photosensitive lithographic printing plates described in JP-A-7-337687.

[0022]

EXAMPLES The effects of the present invention will now be illustrated by examples.

Example 1 (Preparation of Support A) An aluminum plate (material: 1050, tempered H16) having a thickness of 0.3 mm was kept at 85 ° C.
It was immersed in a 0% aqueous sodium hydroxide solution, degreased for 1 minute, and then washed with water. The degreased aluminum plate was immersed in a 10% aqueous sulfuric acid solution kept at 25 ° C. for 1 minute, subjected to desmut treatment, and washed with water. Next, this aluminum plate was roughened in a 2.0% nitric acid aqueous solution at a temperature of 30 ° C. and a current density of 80 A / dm ² for 30 seconds. Then, it was immersed in a 1% aqueous solution of sodium hydroxide maintained at 70 ° C. for 10 seconds and washed with water. Then 2
It was immersed in a 10% aqueous sulfuric acid solution maintained at 5 ° C. for 10 seconds, and then washed with water. Then, in a 30% aqueous sulfuric acid solution, at a temperature of 35
Anodizing was performed for 1 minute at a temperature of 3 ° C. and a current density of 3 A / dm ² , followed by washing with water.

Thereafter, the film was immersed in a 0.1% aqueous solution of polyvinyl phosphonic acid kept at 80 ° C. for 30 seconds,
After drying for 5 minutes, an aqueous solution of JIS No. 3 sodium silicate (10 g / l) was applied to the back surface and dried at 80 ° C. for 3 minutes to prepare an aluminum support A having a coating layer on the back surface. The coating layer was applied so as to have a dry weight of 10 mg / m ² .

(Support B) A support B was prepared in the same manner as the support A except that the aqueous solution of polyvinyl phosphonic acid was replaced with carboxymethyl cellulose.

Next, a photosensitive composition coating solution having the following composition was applied to the surface of the aluminum support and dried at 80 ° C. for 2 minutes to obtain a photosensitive lithographic printing plate in the combination shown in Table 1. At this time, the photosensitive composition coating solution was adjusted to have a dry weight of 2.0 / m ² .

(Photosensitive Composition 1) Polymer Compound 1 0.20 g Hydroxypropyl-β-cyclodextrin 0.20 g Novolak resin (Mw at a molar ratio of phenol / m-cresol / p-cresol of 10/54/36) 6.70 g Condensate of pyrogallol acetone resin (Mw: 3000) and o-naphthoquinonediazide-5-sulfonyl chloride (esterification ratio 30%) 1.50 g Polyethylene glycol # 2000 0.20 g Victoria Pure Blue BOH (Hodogaya 0.09 g 2,4-bis (trichloromethyl) -6- (p-methoxystyryl) -s-triazine 0.15 g Fluorinated surfactant FC-430 (manufactured by Sumitomo 3M) 0.05g cis-1,2 cyclohexanedicarboxylic acid 0.20g Methyl ethyl ketone / propylene glycol monomethyl ether = 3/7 100ml

[0028]

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(Photosensitive composition 2) Polymer compound 2 0.50 g Novolak resin (Mole ratio of phenol / m-cresol / p-cresol is 10/54/36 and Mw is 3500) 6.50 g Pyrogallol acetone resin ( Mw: 2000) and a condensate of o-naphthoquinonediazide-5-sulfonyl chloride (esterification rate 30%) 1.70 g polyethylene glycol # 2000 0.20 g Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.) 0.08 g 2 1,4-bis (trichloromethyl) -6- (p-methoxystyryl) -s-triazine 0.15 g FC-430 (manufactured by Sumitomo 3M) 0.03 g cis-1,2 cyclohexanedicarboxylic acid 0.15 g methyl Cellosolve / ethyl cellosolve = 3/7 100ml

[0030]

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(Photosensitive Composition 3) Polymer Compound 2 1.20 g Novolak resin (Mole ratio of phenol / m-cresol / p-cresol is 5/57/38 and Mw is 4000) 6.50 g Pyrogallol acetone resin ( Mw: 2000) and a condensate of o-naphthoquinonediazide-5-sulfonyl chloride (esterification rate 30%) 1.40 g Condensation resin of p-cresol and formaldehyde (Mw: 1500) and o-naphthoquinonediazide-4-sulfonyl chloride 0.30 g Polyethylene glycol # 2000 0.20 g Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.) 0.06 g Ethyl violet 0.02 g 2,4-bis (trichloromethyl)- 6- (p-methoxystyryl) -s-tria Gin 0.15 g FC-430 (Sumitomo 3M) 0.03 g cis-1,2-cyclohexanedicarboxylic acid 0.20 g Methyl cellosolve / ethyl cellosolve = 3/7 100 ml (photosensitive composition 4) m-cresol- Formaldehyde novolak resin (Mw: 1700) 0.30 g Cresol-formaldehyde novolak resin (m-cresol / p-cresol molar ratio: 60/40, Mw: 3000) 1.10 g Pyrogallol acetone resin and o-naphthoquinonediazide 5- Condensate of sulfonyl chloride (as described in the examples of U.S. Pat. No. 3,635,709) 0.45 g Tetrahydrophthalic anhydride 0.10 g Benzoic acid 0.02 g Oil Blue # 603 (Orient Chemical Industry Co., Ltd.) )) 0.04 g 4- [p- -(P-hydroxybenzoyl) aminophenyl] -2,6-bis (trichloromethyl) -s-triazine 0.02 g Megafac F177 (manufactured by Dainippon Ink and Chemicals, Inc.) 0.02 g methyl ethyl ketone 15.0 g propylene glycol Monomethyl ether 10.0 g Table 1 shows a sample obtained by combining the above support and the photosensitive composition.

[0032]

[Table 1]

Next, the treatment liquid formulation of the present invention will be described.

[Example of Developing Solution of Fatty Acid + Organic Acid] (Developing Solution 1) Concentrated Developing Solution (6-fold Concentrated Solution) 100 parts by weight of potassium silicate (SiO ₂ : 26 wt%, K ₂ O: 13 wt%) Potassium hydroxide 25 Parts by weight Lauric acid 0.3 parts by weight Acetic acid 3 parts by weight Water 200 parts by weight Diluted with 5 volumes of water with respect to 1 volume of the above concentrated liquid.

(Development replenisher 1) Concentrated developer replenisher (4-fold concentrated solution) 100 parts by weight of potassium silicate (SiO ₂ : 26 wt%, K ₂ O: 13 wt%) 26 parts by weight of potassium hydroxide 0.05 part by weight of lauric acid Part Acetic acid 0.5 parts by weight Water 80 parts by weight Diluted with 3 volumes of water per 1 volume of the above concentrated liquid.

(Developer 2) Concentrated developer (6-fold concentrated solution) 100 parts by weight of potassium silicate (SiO ₂ : 26 wt%, K ₂ O: 13 wt%) 25 parts by weight of potassium hydroxide 0.03 parts by weight of myristic acid acetic acid 3 parts by weight Water 200 parts by weight Diluted with 5 volumes of water per 1 volume of the above concentrated liquid.

(Development replenisher 2) Concentrated developer replenisher (4-fold concentrated solution) 100 parts by weight of potassium silicate (SiO ₂ : 26 wt%, K ₂ O: 13 wt%) 26 parts by weight of potassium hydroxide 0.005 part by weight of myristic acid Part Acetic acid 0.5 parts by weight Water 80 parts by weight Diluted with 3 volumes of water per 1 volume of the above concentrated liquid.

[Example of developing solution without fatty acid + organic acid] (Developing solution 3) Concentrated developing solution (6 times concentrated solution) 100 parts by weight of potassium silicate (SiO ₂ : 26 wt%, K ₂ O: 13 wt%) potassium hydroxide 25 parts by weight Lauric acid 0.3 parts by weight Water 200 parts by weight One volume of the above concentrated liquid diluted with 5 volumes of water.

(Development Replenisher 3) Concentrated Developer Replenisher (4-fold concentrated) 100 parts by weight of potassium silicate (SiO ₂ : 26 wt%, K ₂ O: 13 wt%) 25 parts by weight of potassium hydroxide 0.05 parts by weight of lauric acid Part Water 80 parts by weight Diluted with 3 volumes of water per 1 volume of the above concentrated liquid.

[Example of Developing Solution of Fatty Acid + Organic Solvent] (Developing Solution 4) Concentrated Developing Solution (6-fold Concentrated Solution) Potassium Silicate (SiO ₂ : 26 wt%, K ₂ O: 13 wt%) 100 parts by weight Potassium hydroxide 25 Parts by weight Lauric acid 0.3 parts by weight Ethanol 30 parts by weight Water 45 parts by weight Diluted with 5 volumes of water per 1 volume of the above concentrated liquid.

(Development replenisher 4) Concentrated developer replenisher (4-fold concentrated solution) 100 parts by weight of potassium silicate (SiO ₂ : 26 wt%, K ₂ O: 13 wt%) 26 parts by weight of potassium hydroxide 0.05 part by weight of lauric acid Part ethanol 5 parts by weight water 75 parts by weight Diluted with 3 volumes of water per 1 volume of the above concentrated liquid.

[Example of developer containing amphoteric surfactant] (Developer 5) Concentrated developer (6-fold concentrated solution) 100 parts by weight of potassium silicate (SiO ₂ : 26 wt%, K ₂ O: 13 wt%) 25 parts by weight of potassium 2 parts by weight of Amogen K (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 200 parts by weight of water A solution obtained by diluting 1 volume of the above concentrated liquid with 5 volumes of water.

(Development replenisher 5) Concentrated developer replenisher (4-fold concentrated) 100 parts by weight of potassium silicate (SiO ₂ : 26 wt%, K ₂ O: 13 wt%) 25 parts by weight of potassium hydroxide Amogen K (Daiichi Kogyo) 0.8 parts by weight Water 80 parts by weight Diluted with 3 volumes of water per 1 volume of the above concentrated liquid.

[Example of a developing solution using an amphoteric surfactant and an organic acid together] (Developing solution 6) Concentrated developing solution (6 times concentrated solution) Potassium silicate (SiO ₂ : 26 wt%, K ₂ O: 13 wt%) 100 wt Part Potassium hydroxide 25 parts by weight Amogen K (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) 1 part by weight 2-hydroxy-3-naphthoic acid 4 parts by weight Water 200 parts by weight Dilute with 5 volumes of water with respect to 1 volume of the above concentrated liquid. What you did.

(Development replenisher 6) Concentrated developer replenisher (4-fold concentrated) 100 parts by weight of potassium silicate (SiO ₂ : 26 wt%, K ₂ O: 13 wt%) 25 parts by weight of potassium hydroxide Amogen K (Daiichi Kogyo) 0.4 parts by weight 2-hydroxy-3-naphthoic acid 1.5 parts by weight Water 80 parts by weight A solution obtained by diluting 1 volume of the above concentrated liquid with 3 volumes of water.

[Example of a developer using an amphoteric surfactant and an organic solvent in combination] (Developer 7) Concentrated developer (6 times concentrated solution) Potassium silicate (SiO ₂ : 26 wt%, K ₂ O: 13 wt%) 100 wt Part Potassium hydroxide 25 parts by weight Amogen K (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 2 parts by weight Propylene glycol 1 part by weight Water 200 parts by weight A solution obtained by diluting 5 parts by volume of water with respect to 1 part of the above concentrated liquid.

(Development Replenisher 7) Concentrated Developer Replenisher (4-fold concentrated) 100 parts by weight of potassium silicate (SiO ₂ : 26 wt%, K ₂ O: 13 wt%) 25 parts by weight of potassium hydroxide Amogen K (Daiichi Kogyo) 0.8 parts by weight Propylene glycol 0.4 parts by weight Water 80 parts by weight A solution obtained by diluting 1 volume of the above concentrated liquid with 3 volumes of water.

[Evaluation method] (Solubility and long-term storage property) The above-mentioned concentrated solutions for development and replenished solutions for replenishment were prepared, and the solubility was visually evaluated.

Next, the prepared concentrated concentrates for development and replenishment for development replenishment were diluted with water until they reached the concentrations used for development, and the solubility after dilution was also evaluated visually.

Further, the above-mentioned developing concentrates and developing replenishing concentrates 1 to 7 and their respective use solutions were evaluated for long-term storability. As an evaluation method, a method of visually evaluating that no precipitation or coloring was caused by leaving the substrate at 55 ° C. for 4 days was adopted.

Table 2 shows the above evaluation results.

[0052]

[Table 2]

From the results shown in Table 2, the developing solution and the developing replenisher in which the fatty acid or betaine-based amphoteric surfactant of the present invention contains an organic acid have good solubility and storage stability in both the concentrated solution and the used solution. You can see that.

Next, the photosensitive lithographic printing plate, a developing solution and a developing replenisher were processed in combination as shown in Table 3, and the following evaluation was performed. The results are shown in Table 3 below.

(Ink-coating property and printing stain) An original film having a halftone dot pattern and a step tablet for sensitivity measurement (No. 2, manufactured by Eastman Kodak Co., Ltd., 21 steps of gray scale with a density difference of 0.15 each) are closely attached to the photosensitive lithographic printing plate sample of ,
8.0mW / using 2kW metal halide lamp as light source
Exposure was performed for 60 seconds from a distance of 70 cm under the condition of cm ² .

Next, the developing use solution and the developing replenishment use solution of the above 1 to 7 were added to an automatic developing machine (PSZ-90 manufactured by Konica Corporation).
0), and the exposed samples were developed at 30 ° C. for 12 seconds.

The obtained photosensitive lithographic printing plate was mounted on a printing press (DAIYA1F-1 manufactured by Mitsubishi Heavy Industries, Ltd.), and coated paper and dampening solution (etching solution SG-51 manufactured by Tokyo Ink Co., Ltd.) were used.
(Density: 1.5%) and ink (High Plus M Red manufactured by Toyo Ink Mfg. Co., Ltd.).

The evaluation of the print smear was made under the above printing conditions by 50.
After printing 00 sheets, the ink stain on the blanket (the area corresponding to the non-image area on the plate) is peeled off using cellophane tape, and then attached to a blank paper to visually evaluate the degree of the stain, and stopped for 5 minutes. Is inserted, and printing is repeated 100 times at a time, and the number of stains on the non-image portion of the printed coated paper is visually evaluated.

The ink inking property was visually evaluated according to the following criteria.

(Suitability of Ballpoint Pen) A straight line is drawn using a ballpoint pen on an unexposed portion of the photosensitive lithographic printing plate before development, and then developed by the above-described method to determine the degree of missing of the photosensitive layer in the drawn portion by differential interference. Observation was carried out using a microscope, and the evaluation was performed visually based on the criteria described below.

(Foaming property) Shake the developing replenisher solution in a sealed transparent container. The amount of foam generated at this time (A) and the amount of foam remaining without disappearing even after a certain period of time have elapsed. (B) is measured. (A) and (B) were comprehensively evaluated and evaluated according to the criteria described below.

(Sticking mark) A sample was prepared by the same exposure and development method as in the ink depositing property and printing stains (described above) except that an original film for sticking mark evaluation was used. An evaluation was performed.

The above evaluation criteria are as follows, and the results are shown in Tables 3 and 4.

◎: particularly good, ：: good, Δ: practicable, ×: poor, not practicable

[0065]

[Table 3]

[0066]

[Table 4]

From the results shown in Tables 3 and 4, when processing was carried out using a developing solution or a developing replenisher containing a fatty acid or a betaine-based amphoteric surfactant containing an organic acid according to the present invention, ink inking property and ballpoint pen suitability were obtained. It can be seen that all of the evaluations of foamability and sticking marks were good.

Tables 5 and 6 conceptually show the effect of adding or not adding an organic acid to a fatty acid or a betaine-based amphoteric surfactant, respectively.

[0069]

[Table 5]

[0070]

[Table 6]

[0071]

Industrial Applicability According to the present invention, printing stains are reduced, and even when the developer is stored for a long period of time, it does not separate and precipitate. Further, the foaming property of the developer, the suitability of the developed photosensitive lithographic printing plate for ballpoint pen, and the adhesion A developing solution for a photosensitive lithographic printing plate free from deterioration of the imprint and a method for preparing the same can be provided.

Claims (3)

[Claims] 1. A developing solution for a photosensitive lithographic printing plate comprising a higher fatty acid as an additive, wherein the developing solution for a photosensitive lithographic printing plate comprises an organic acid. 2. The photosensitive lithographic printing plate developing method according to claim 1, wherein a higher fatty acid is mixed and dissolved in an organic acid and then mixed with an alkali metal silicate during the preparation of the photosensitive lithographic printing plate developing solution. Preparation of treatment liquid. 3. A developing solution for a photosensitive lithographic printing plate comprising a betaine-based amphoteric surfactant as an additive, wherein the developing solution for a photosensitive lithographic printing plate comprises an organic acid.