JPH04304458A - Processing method for dampening waterless photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE:To suppress the degradation in the concn. of a dyeing liquid and the dyeing density of image parts. CONSTITUTION:The concn. of the dyeing liquid is <=30 times the liquid to be used in the method for replenishing the dyeing liquid having the concn. higher than the concn. of the dyeing liquid to the dyeing liquid in a dyeing stage for the image parts after a developing stage of the dampening waterless photosensitive planographic printing plate. Absorbance, area, number of processing sheets, operating time, stop time, liquid volume, etc., are detected in order to detect the concn. of the dyeing liquid. For example, the fall of the liquid level is detected by a liquid level detecting sensor and the loss component of the evaporated water is replenished. The absorbance is detected and a dye concentrated liquid is replenished.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a processing method that improves running properties when automatically conveying and processing photosensitive lithographic printing plates that do not require dampening water. The present invention relates to a method for processing a photosensitive lithographic printing plate that does not require dampening water, and which suppresses a decrease in dyeing density in the area.

0002

BACKGROUND OF THE INVENTION In recent years, printing plates that print without using dampening water have been developed, such as those in which a photosensitive layer and a silicone rubber layer are sequentially provided on a support. This is called an unnecessary photosensitive lithographic printing plate.

[0003] This photosensitive lithographic printing plate that does not require dampening water is subjected to image exposure and then developed using, for example, an aqueous developer to obtain a printing plate, but this printing plate visually has an image area and a non-image area. There is a problem in that it is difficult to clearly distinguish visually, and therefore, in order to obtain plate inspection properties after development, a photosensitive lithographic printing plate that does not require dampening water is developed and then dyed.

As a method for this dyeing, the Toray Co., Ltd. photosensitive lithographic printing plate processing system (TWL) that does not require dampening water has been known, and in this method, the concentration of the dyeing liquid used is
The diluted solution is diluted twice to replenish the reduced amount. Furthermore, JP-A-2-264957 discloses a waterless lithographic printing plate developing device which dyes a waterless lithographic printing plate in a dyeing tank after developing it, and which detects the throughput of the waterless lithographic printing plate. inspection

[0005] The apparatus is characterized in that it has a discharge means, a replenishment means for replenishing the staining solution into the dyeing tank, and a control means for operating the replenishment means based on the throughput amount detection means to replenish the staining solution. A waterless lithographic printing plate developing device is described, in which when the concentration of the dye solution to be replenished is high, a dilution water tank containing dilution water is provided separately from the dye solution tank;
It has also been shown that it is preferable to supply the dyeing solution and dilution water to the dyeing solution recovery tank, respectively.

[0006] In this dyeing process, the dyeing solution is normally reused by circulating it, but in this method of circulating and reusing, water evaporates relatively frequently, so the concentration of components in the dyeing solution increases during dyeing. Generally speaking, a decrease in density is unlikely to occur, but the treatment process before the dyeing process may include not only the development process but also various processes such as washing with water and rinsing, and depending on the plate processed in such processes, Processing solutions such as a developer, washing water, and rinsing solution are brought into the dyeing solution and the dyeing solution is diluted.

Furthermore, depending on the working environment conditions (such as when the ambient temperature is low and the amount of water evaporated is small, when the number of times the dye solution is circulated, or when the amount of plate processing (processing area) is large relative to the circulation time of the dye solution, etc.) There is a problem in that the concentration decreases further.

As a result of various studies on these problems, the inventors of the present invention found that the cause of the problem is that the processing solution flows into the dyeing solution more than the evaporation of water, and the working environment conditions combine to cause the dyeing solution to evaporate. It was discovered that the concentration usually decreases while the concentration increases, and this problem was solved by using a solution with a higher concentration than the staining solution used, and the present invention was thus achieved.

[0009]

OBJECTS OF THE INVENTION Therefore, it is an object of the present invention to provide a method for processing a photosensitive lithographic printing plate that does not require dampening water and is capable of improving running properties, that is, suppressing a decrease in dyeing solution concentration and dyeing density in image areas. It's about doing.

0010

[Structure of the Invention] The above object of the present invention is to provide a method for automatically transporting and processing a photosensitive lithographic printing plate that does not require dampening water after image exposure. This is achieved by a method for processing a photosensitive lithographic printing plate that does not require dampening water, which is characterized by replenishing a dyeing solution with a higher concentration than the dyeing solution used.

The present invention will be explained in more detail below. The present invention provides a dyeing solution in which the concentration of at least one component in the dyeing solution is higher than the concentration of the corresponding component in the dyeing solution used in the dyeing process.
Hereinafter, it is also referred to as a dye concentrate or simply a concentrate. ), it is possible to improve the running properties, that is, to suppress the decrease in the staining solution concentration and the staining concentration in the image area.

[0012] In the dyeing process used in the present invention, the dyeing solution is circulated and reused, and when the dyeing solution is replenished with a dyeing concentrate under such a process, the concentration of the replenishing dyeing solution is the same as that used for dyeing. It is higher than the liquid and 30 times or less than the working liquid, preferably 1.5 to 10 times.

[0013] In the present invention, there are various detection methods for detecting the concentration of the staining solution. For example, there are methods of detecting absorbance, area, number of sheets processed, running time, stopping time, liquid volume, etc., and preferably This method measures the absorbance and calculates the amount of liquid to be replenished based on the decrease from the set value.

Further, replenishment of the concentrated liquid can be effectively carried out by detecting the processing amount per unit operating time and replenishing the concentrated liquid according to the value when the amount exceeds a predetermined amount. A preferred detection method in the present invention is an area detection method, and this method uses, for example, an aluminum detector that detects the area of a photosensitive lithographic printing plate that does not require dampening water. A plurality of units are arranged along the width direction of the photosensitive lithographic printing plate that does not require dampening water, and by measuring the time it takes for the photosensitive lithographic printing plate that does not require dampening water to pass over the top of this aluminum detector, it is possible to detect the Detect area.

Alternatively, instead of directly measuring the area, the length of the width direction of the photosensitive planographic printing plate that does not require dampening water is input into the control device in advance, and the length is detected using a single phototube. may be calculated. In the present invention, if a large amount of water evaporates and the absorbance increases due to changes in the working environment conditions, it is preferable to replenish the water. Detects,
Replenish water accordingly. Therefore, water is replenished when the absorbance is above the set value, and concentrated liquid is replenished when the absorbance is below the set value.

In addition, as a method for detecting a drop in the liquid level and replenishing water, it is also preferable to use a liquid level detection sensor. In this method, as shown in FIG. 2, the liquid level is detected using a float switch as the liquid level detection sensor. In this example, sensing parts 772 and 773 are provided at the upper and lower parts of the shaft 774, and when the liquid level matches the sensing parts (not shown) of the float 771 at these positions, the liquid level is detected and a signal is sent to the control device C. is sent, the liquid feed pump 733 is operated, and the water 63 is automatically replenished. In addition, various conventionally known liquid level detection sensors can be used.

[0017] This liquid level detection is preferably carried out when the operation of the automatic processing apparatus is stopped. In the present invention, it is preferable to provide a step of washing or rinsing with water between the developing step and the dyeing step. As the rinsing liquid, an aqueous solution containing an organic acid, an inorganic acid or a salt thereof, a surfactant, etc. is used. Preferably used inorganic acids include:
Examples include hydrochloric acid, phosphoric acid, polyphosphoric acid, sulfuric acid, nitric acid, sulfurous acid, nitrous acid, and boric acid.

Examples of organic acids include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, oxalic acid, cyclohexanecarboxylic acid, cyclohexanedicarboxylic acid, tartaric acid, succinic acid, citric acid, malic acid, lactic acid, gluconic acid, and tannic acid. , ascorbic acid, levulinic acid, phthalic acid, benzoic acid, salicylic acid, gallic acid, naphthoic acid, hydroxynaphthoic acid, and the like.

Among these, particularly preferred are aliphatic carboxylic acids such as acetic acid, and oxyacids such as gluconic acid and citric acid. Furthermore, effects can be obtained even when these acids contain salts with alkali metals such as sodium and potassium. The amount of acid added to the rinse solution is 0.01% by weight
~10% by weight, preferably ~0.1% by weight
It is in the range of 5% by weight.

[0020] As the surfactant, anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric ionic surfactants, etc. are used. Specifically, the anionic surfactants include (1) higher alcohols; Sulfuric esters, (e.g. sodium salt of lauryl alcohol sulfate, ammonium salt of octyl alcohol sulfate, ammonium salt of lauryl alcohol sulfate, sulfonic sodium alkyl sulfate, etc.)

(2) Aliphatic alcohol phosphate ester salts (for example, sodium salt of cetyl alcohol phosphate ester, etc.) (3) Alkylaryl sulfonates (for example, dodecylbenzenesulfonic acid sodium salt, isopropylnaphthalene sulfonic acid sodium salt) , dinaphthalenesulfonic acid sodium salt, metanitrobenzenesulfonic acid sodium salt, etc.)

0022
] (4) Alkylamide sulfonates, (C17H3
5CON(CH3)CH2CH2SO3Na etc.) (5
) sulfonic acid salts of dibasic aliphatic esters (e.g. sodium sulfosuccinate dioctyl ester, sodium sulfosuccinate dihexyl ester, etc.) (6) formaldehyde condensates of alkylnaphthalene sulfonates;
(For example, formaldehyde condensate of sodium dibutylnaphthalene sulfonate, etc.).

Examples of nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkylphenol ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, oxyethylene sorbitan fatty acid ester, glycerin fatty acid ester, oxyethylene oxypropylene block polymer, etc. Can be mentioned.

[0024] Examples of the cationic surfactant include alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamines, and the like. Examples of amphoteric surfactants include alkyl betaines, and among these, anionic surfactants are suitable. These surfactants can be used alone or in combination of two or more.

The appropriate amount of the surfactant used in the present invention is 0.01% to 60% by weight, preferably 0.1% to 10% by weight. Furthermore, before the dyeing process, when a treatment with a developer, washing water, rinsing liquid, etc. is performed, the treatment liquid is carried into the staining liquid and the staining liquid is diluted. In such a case, a dyeing solution darker than the used solution is replenished, but such a step can also be combined with a water replenishing step.

[0026] The staining liquid used in the present invention may be one or two types.
One or more dyes dissolved or dispersed in an aqueous solution of an organic solvent such as water, alcohol, or ether is used. This staining solution also has the ability to improve dyeing density, prevent unevenness,
In order to prevent precipitation in the dyeing solution, acids or salts thereof, surfactants, etc. similar to those used in the rinsing solution are added, and it is also preferable to add chelating agents, dyeing aids, etc.

The dyes used in the present invention include diphenylmethane, triphenylmethane, acridine,
Thiazine series, azine series, oxazine series, phenazine series,
There are xanthene-based, anthraquinone-based, iminonaphthoquinone-based, and azomethine-based dyes, and specifically, there are the following.

Brilliant green, eosin, ethyl violet, erythrosin B, methyl green, crystal violet, basic fuchsin, phenolphthalein, 1,3-diphenyltriazine, alizarinlet S, thymolphthalein, methyl violet 2B, quinaldine red, Rose Bengal, methanyl yellow, thymol sulfophthalein, xylenol blue, methyl orange, orange IV, diphenylthiocarbazone, 2,7-dichlorofluorescein,

002
9] Paramethyl red, Congo red, benzopurpurin 4B, α-naphthyl red, nine blue 2B, nine blue A, phenacetaline, methyl violet,
Malachite green, parafuchsin, oil blue #6
03 (manufactured by Orient Chemical Industry Co., Ltd.), oil pink #31
2 (manufactured by Orient Chemical Industry Co., Ltd.), Oil Red 5B (manufactured by Orient Chemical Industry Co., Ltd.), Oil Scarlet #308
(manufactured by Orient Chemical Industry Co., Ltd.), Oil Red OG (manufactured by Orient Chemical Industry Co., Ltd.), Oil Red R

[0030]R
(manufactured by Orient Chemical Industry Co., Ltd.), Oil Green #502
(manufactured by Orient Chemical Industries, Ltd.), Spiron Red BEH Special (manufactured by Hodogaya Chemical Industries, Ltd.), Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Industries, Ltd.), Patent Pure Blue (manufactured by Sumitomo Mikuni Chemical Industries, Ltd.), Sudan Blue I
I (manufactured by BASF), m-cresol purple, cresol red, rhodamine B, rhodamine 6G, fast acid violet R, sulforhodamine B, auramine, 4-p-diethylaminophenyl imino naphthoquinone, 2-carboxyanilino-4- p-diethylamide

Nophenylimino naphthoquinone, 2-carbostearylamino-4-p-dihydroxyethyl-
Amino-phenylimino naphthoquinone, p-methoxybenzoyl-p'-diethylamino-o'methylphenyliminoacetanilide, cyano-p-diethylaminophenylaminoacetanilide, 1-phenyl-3-methyl-4-p-diethylaminophenylimino-5- Pyrazolone, 1-β-naphthyl-4-p-diethylaminophenylimino-5-pyrazolone, a dye in which the counter anion of a basic dye has a sulfonic acid group, and the like.

Among these, triphenylmethane type, xanthene type, oxacin type, thiazine type, monoazo type,
Quinoneimide dyes are preferred, and triphenylmethane dyes are particularly preferred. The amount of the dye used in the present invention is 0.1% to 5% by weight, preferably 0.2% to 3% by weight, based on the dyeing solution.

These dyes can be used alone or in combination of two or more. As the organic solvent used in the present invention, known organic solvents can be used, and for example, most of those described in "Solvent Pocket Book" (Ohm Co., Ltd.) can be used.

In order to improve the dyeing density, organic solvents having a solubility in water at 20° C. of less than 10% by weight, so-called poorly water-soluble organic solvents, are preferably used, such as diisobutyl ketone, acetophenone, isophorone, diethyl succinate, Methyl benzoate, diethyl oxalate, dimethyl phthalate, isobutyl acetate, benzyl benzoate, ethylene glycol monophenyl ether, ethylene glycol dibutyl ether, ethylene glycol benzyl ether, diethylene glycol di-n-butyl ether, diethylene glycol diacetate, n-amyl alcohol, benzilua

Examples include alcohol, cyclohexanone, cyclohexanol, N-benzylethanolamine, anisyl alcohol, dimethylbenzylcarbitol, 2-N-ethylanilinoethanol, propylene glycol monophenyl ether, N-phenylethanolamine, and the like.

Among these, ethylene glycol monophenyl ether, ethylene glycol benzyl ether, benzyl alcohol, cyclohexanone, cyclohexanol, N-benzylethanolamine, anisyl alcohol, dimethylbendicarbeetle, 2-N-ethylanilinoethanol, Propylene glycol monophenyl ether and N-phenylethanolamine are particularly effective.

[0037] The amount of organic solvent used in the present invention is:
1% to 10% by weight, preferably 2% to 6% by weight
is preferred. Furthermore, an organic solvent having a solubility in water at 20° C. of 10% by weight or more is also preferably used.

[0038] Among the organic solvents having a solubility in water of 10% or more at 20°C used in the present invention, the alcohols include methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, t-butanol, Examples include furfuryl alcohol and tetrahydrofurfuryl alcohol. Examples of the ether or acetal include 1,2-propylene oxide, 1,4-dioxane, tetrahydrofuran, and methylal.

Examples of the ketone include acetone, methyl acetone, methyl ethyl ketone, acetone oil, acetonyl acetone, diacetone alcohol and the like. Examples of esters include methyl formate, methyl acetate, methyl lactate, and ethyl lactate.

Examples of polyhydric alcohols and their derivatives include ethylene glycol, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether, ethylene glycol diethyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol isopropyl ether, ethylene glycol monobutyl ether, and ethylene glycol. Glycol dibutyl ether, ethylene glycol monobutyl ether acetate,
Ethylene glycol isoamyl ether, ethyl

004
1] Len glycol monophenyl ether, methoxymethoxyethanol, ethylene glycol monoacetate, ethylene glycol diacetate, ethylene chlorohydrin, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether,
Diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethyl

Ren glycol diethyl ether, diethylene glycol acetate, triethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, tetraethylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, 1-butoxyethoxypropanol, propylene Chlorhydrin, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether

Tyl ether, tripropylene glycol monomethyl ether,
Trimethylene glycol, butanediol, 1,5-pentadiol, hexylene glycol, glycerin, glyceryl monoacetate, glyceryl diacetate, glycerin ether, glycerin-α-monochlorohydrin, glycerin-α-,γ-dichlorohydrin, trimethylol Examples include propane, 1,2,6-hexanetriol, and the like.

[0044] As the nitrogen compound, monomethylamine,
Dimethylamine, trimethylamine, monomethylamine, diethylamine, triethylamine, isopropylamine, n-butylamine, isobutylamine, sec-
Butylamine, n-amylamine, sec-amylamine, sec-hexylamine, cyclohexylamine,
Monoethanolamine, diethanolamine, triethanolamine, ethyl monoethanolamine, n-butyl monoethanolamine, dimethylethanol

004
5] Amine, diethylethanolamine, ethyldiethanolamine, n-butyldiethanolamine, triisopropanolamine, isopropanolamine (mixture), formamide, acetamide, acetonitrile,
Examples include pyridine, α-picoline, β-picoline, γ-picoline, 2,4-lutidine, 2,6-lutidine, quinoline, and morpholine. Among these organic solvents, alcohols, polyhydric alcohols and derivatives thereof are preferably used.

The content of these organic solvents is 0.1% to 40% by weight, preferably 0.1% to 40% by weight, based on the dyeing solution.
It is 5% to 15% by weight. Both of the organic solvents used in the present invention can be used alone or in a mixture of two or more. Moreover, both organic solvents can also be used in combination. When a poorly water-soluble organic solvent is used in the dyeing solution, tar is likely to be generated in the dyeing solution, so when such a dyeing solution is used, it is particularly preferable to replenish water, thereby preventing the generation of tar.

Furthermore, in the present invention, a chelating agent can be blended, and the chelating agent includes a compound that forms a chelate compound by coordinating with a metal ion, such as polysulfonic acids, especially aminopolycarboxylic acids. is preferred. These aminopolycarboxylic acids have the general formula
=N-(CH2)) n-COOR [wherein, n represents 1 or 2, and R represents a hydrogen atom or an alkali metal. ] is a compound having a group represented by the following in its molecule, and if -(CH2)) n -COOR is represented by X, it can be classified as follows.

(1) RNX2 type compound (2) NX3
Compound (3) R-NX-CH2 -CH2 -NX-R type compound (4) R-NX-CH2 -CH2 -NH2 type compound (5) Compound containing X2 N-R'-NX2 type and 4 or more of X [Wherein, R represents a hydrogen atom, an organic group which may have a substituent such as an alkyl group, a hydroxyalkyl group, an alkoxyalkyl group, and R' is a chain or cyclic alkylene group,
Represents an organic group such as a phenylene group or a substituted product thereof. ]

0
[049] Typical examples of aminopolycarboxylic acids include iminodiacetic acid, iminodipropionic acid, N-(
3,3-dimethylbutyl)iminodiacetic acid, mercaptoethyliminodiacetic acid, methoxyethyliminodiacetic acid, methylthioethyliminodiacetic acid, N-(carbamoyl)iminodiacetic acid, aminoethyliminodiacetic acid, 2-ethoxycarbonylaminoethyliminodiacetic acid Acetic acid, sulfoethyliminodiacetic acid, nitrilotriacetic acid, carboxyethyliminodiacetic acid, N,N'-ethylenediaminediacetic acid, N-(2
-Hydroxycyclohexyl)ethylenediaminetriacetic acid, N'-

Hydroxyethyl-ethylenediamine-N
, N,N'-triacetic acid, ethylenediaminetetraacetic acid,
Ethylenediamine-N,N'-dipropionic acid, 1,2
-Propylenediaminetetraacetic acid, trimethylenediaminetetraacetic acid, hexaethylenediaminetetraacetic acid, 1
, 2cyclopentanediaminetetraacetic acid, trans-
Cyclohexane-1,2-diaminetetraacetic acid, 2,2
'-Diaminoethyl ether-N,N,N',N'-tetraacetic acid, diethylenetriaminepentaacetic acid, glycoldiaminetetraacetic acid, thioglycoldiaminetetraacetic acid, 2,2'-

Diaminoethylthioether-N,N,N
',N'-tetraacetic acid, N',N''-dimethyltrimethylenetetramine-N,N,N,N''',N'''
Examples include -tetraacetic acid, trimethylenetetraminehexaacetic acid, and their sodium or potassium salts. Among these, ethylenediaminetetraacetic acid or its alkali metal salt is advantageous in terms of effectiveness and ease of availability.

[0052] The staining solution used in the present invention contains at least one of the above chelating agents in a range of 0.01% to 2% by weight, preferably 0.05% to 0.5% by weight.
% by weight. The photosensitive lithographic printing plate used in the present invention is generally a well-known photosensitive lithographic printing plate that does not require dampening water, and has a structure in which a photosensitive layer and a silicone rubber layer are sequentially provided on a support. It has a basic configuration and includes various types.

In order to process this photosensitive lithographic printing plate that does not require dampening water, first, the cover film is removed from the exposed photosensitive lithographic printing plate that does not require dampening water, and then it is subjected to a development process, and then washed with water. After dyeing in the dyeing process, wash with water,
dry.

EXAMPLES Next, examples of the present invention will be described based on the drawings, but the present invention is not limited only to these examples.

Example 1 [Synthesis of diazo resin -1] 14.5 g (50 mmol) of p-diazodiphenylamine sulfate was dissolved in 40.9 g of concentrated sulfuric acid under ice cooling. 1.35 g (45 mmol) of paraformaldehyde was gradually added to this reaction solution so that the reaction temperature did not exceed 10°C.

[0055] This reaction mixture was added dropwise to 500 ml of ethanol under ice-cooling, and the precipitate formed was filtered. After washing with ethanol, this precipitate was dissolved in 100 ml of pure water, and a cold concentrated aqueous solution containing 6.8 g of zinc chloride was added to this solution. After filtering the resulting precipitate,
It was washed with ethanol and dissolved in 150 ml of pure water. To this liquid was added a cold concentrated aqueous solution in which 8 g of ammonium hexafluorophosphate was dissolved. The resulting precipitate was collected by filtration, washed with water, and then dried to obtain diazo resin-1.

[Preparation of photosensitive lithographic printing plate that does not require dampening water] The following primer layer composition was coated and dried to a film thickness of 15 μm after curing on a smooth aluminum plate that had been degreased in a conventional manner. After that, high pressure mercury lamp (output 80W/cm
) and was exposed to light and cured.

[Primer layer composition] (1) Copolymer of 2-hydroxyethyl methacrylate and methyl methacrylate in a molar ratio of 40/60

100 parts by weight (2) Totimethylolpropane triethoxytriacrylate 8
0 parts by weight (3) 2,4-diethylthioxanthone
4 parts by weight (4) 3 parts by weight of p-dimethylaminobenzoic acid ethyl ester (5) Kett Yellow 402 (manufactured by Dainippon Ink Co., Ltd., yellow pigment)
8 parts by weight (6) Zinc oxide (FINE X-25,
Manufactured by Sakai Chemical Co., Ltd. 25 parts by weight (
7) Propylene glycol monomethyl ether
Next, 600 parts by weight of the photosensitive composition shown below was coated on the primer layer and dried at 100° C. for 2 minutes to form a photosensitive layer having a thickness of 0.5 μm.

[Photosensitive composition] (1) Diazo resin-1

40 parts by weight (2) Copolymer of 2-hydroxyethyl methacrylate, N-(4-hydroxyphenyl)methacrylamide, and acrylic acid in a molar ratio of 50/47/3
50
Part by weight (3) Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd., dye)

1 part by weight (4) Methyl cellosolve
900
Parts by Weight Next, the following silicone rubber composition was coated on the photosensitive layer to a thickness of 2.0 g/m 2 and dried at 90° C. for 10 minutes to obtain a photosensitive lithographic printing plate that did not require dampening water.

[Silicone rubber layer composition] (1) Dimethylpolysiloxane having hydroxyl groups at both ends (molecular weight 52,000)
100 parts by weight (2)
triacetoxymethylsilane
10 parts by weight (3) dibutyltin dilaurate
0.8 parts by weight (4) Isopar G (manufactured by Esso Chemical Co., Ltd.)
900 parts by weight Next, a positive film was vacuum-adhered onto the silicone rubber layer, and then exposed to light using a metal halide lamp as a light source.

[0060] The exposed dampening water-free photosensitive lithographic printing plate was
Development and staining were performed. The processing apparatus used in the method of processing a photosensitive lithographic printing plate that does not require dampening water according to the present invention is shown in FIG. It consists of a second water washing step.

FIG. 1 shows a processing apparatus used in the method of processing a photosensitive lithographic printing plate that does not require dampening water according to the present invention. The plate is carried in by a roller 3 made of rubber or the like, and is detected by a carry-in sensor 7 to identify whether it is a PS plate or a photosensitive lithographic printing plate that does not require dampening water.
In the case of a photosensitive lithographic printing plate that does not require dampening water, the development process is carried out according to the development recipe for the photosensitive lithographic printing plate that does not require dampening water.

The developer used in this development recipe was a solution prepared by diluting SDR-1, a positive PS plate developer manufactured by Konica Corporation, six times with water and adjusting the temperature to 27°C. The developing process section has a developer tank 11 which is open at the top and has an overflow port 19 and a developer waste discharge port 20.
3 are connected via pumps 731 and 732, respectively,
A control device C is used to replenish the developer and adjust the concentration of the developer.

The upper part of the developer tank 11 has a developer spraying part that sprays the developer along the development line, and three brush rolls 21, 22, and 23 arranged along the line, and these brush rolls have a cross section. It is covered with a U-shaped brush cover to prevent developer from scattering. Further, a guide plate 18 for the developer flowing into the developer tank 11 is provided at the bottom of this line. The developer that has passed through the development line by this guide plate 18 flows into the developer tank 11 and is used for circulation.

The developer shower nozzles 51, 52, and 53 installed in the developer injection section are connected via a pump 73 and a filter 74, and the pump 73 supplies developer to each nozzle. After the developer 61 is sprayed from the developer shower nozzle 51 onto the plate, it is rubbed by three brush rolls 21, 22, and 23 to remove the silicone rubber layer in the image area. It is developed by

The rotational speed of the developing brush may vary depending on the individual brush roll, but it is 100 to 800 rpm,
Preferably it is set to 200 to 600 rpm. Next, in the washing process section, the brush roll 2 is placed between the two rollers 3 and 3.
4, a rinsing water spray nozzle 55 is installed facing the roll, and this roll is covered with a brush cover 92. Further, a washing water spray nozzle 56 is located close to the roller 3 located at the rear.

[0066] Sufficient cleaning is performed in this first water washing step. Moreover, a rinsing process can also be performed following this water washing process. In the dyeing process section, rollers 3 are used along the conveyance direction.
, 3 are arranged, and dyeing solution injection nozzles 57, 5 are arranged inside thereof.
8 are arranged so as to be able to spray the dyeing liquid toward the rollers 3, 3 located on the outside, respectively. Further, a rectifier plate is provided between these nozzles 57, 58 and rollers 3, 3 to uniformly control the flow of the dyeing solution. These are covered with a cover 93 to prevent the staining solution from splashing.

A dye tank 16 is located below this conveyance line, and contains a dye liquid 66 having the following composition.Furthermore, an absorbance detector 81 is installed at the bottom of this dye tank 16, and an absorbance detector 81 is installed at the top of the dye tank 16. A liquid level detection sensor 77 is provided. These absorbance detector 81 and liquid level detection sensor 77 are connected to a control device C (not shown) for signal processing. The absorbance detector 81 measures the concentration of the staining solution, and when the concentration decreases, the pump 734 is activated and the staining solution tank 1 is activated.
The concentrated staining solution 65 in 5 is replenished. The liquid level detection sensor 77 is activated when the amount of the staining liquid 66 decreases, and replenishes the lost amount of water.

The dyeing tank 16 is connected to the dyeing solution tank 15 via a pump 734 and also to the dilution water tank 13 via a pump 733, so that the dyeing tank 16 is connected to the dyeing solution tank 15 via a pump 734, and is also connected to the dilution water tank 13 via a pump 733. When replenishing, the concentrated staining liquid (concentrated liquid) stored in this staining liquid tank 15 is used. Here, as the staining solution, a concentrated staining solution is diluted twice and used.

[Composition of staining solution used] Crystal violet
0.1
Part by weight Nonionic surfactant (polyoxyethylene lauryl ether, HLB 17.0)

2.0 parts by weight anionic surfactant (sodium lauryl sulfate) 0.
1 part by weight sodium acetate

0.1 parts by weight benzyl alcohol

3.0 parts by weight gluconic acid (50%
aqueous solution)
1.0 parts by weight Tetrasodium ethylenediaminetetraacetic acid
0.1 parts by weight water

100 parts by weight This dyeing liquid was used at a controlled temperature of 30°C.

In the second washing step, washing nozzles 59 and 90 are provided between the rollers 3 and 3, and the front and back surfaces of the dyed printing plate are washed and then dried. In the present invention, Kikuzen plate is processed in the processing device at a rate of one plate every 1.5 minutes, 200 plates are continuously processed, the absorbance is controlled by the control device C to be constant, and the replenisher is used as a replenisher. A 2-fold concentrated solution was used. (A in Figure 3)

Next, we changed the working environment and processed one Kikuzen version every 10 minutes, processing a total of 1000 versions. At this time, the concentration of the staining liquid 65 is similarly measured by the absorbance detector 81 installed in the staining tank 16 so that the absorbance is constant, and when the concentration rises, the pump 734 is operated and the dilution water 65 is measured.
3 was added. Replenishment is done by replenishing the staining solution while circulating it, and when the concentration becomes equal to the concentration of the unused solution, the pump 73
4 and stopped refilling. (B in FIG. 3) All of the plates mentioned above were dyed well, and no tar was observed in the dyeing solution.

Comparative Example 1 Detecting the processing area of a photosensitive lithographic printing plate that does not require dampening water,
Continuous treatment was carried out in the same manner as in Example 1, except that 20 ml of water was replenished per sample. In FIG. 3A, the absorbance decreased and the staining density decreased as well. Also, B in the diagram
In this case, the dye solution was concentrated by evaporation and a tar-like precipitate was generated. As a result, tar and the like adhered to the plate surface and appeared as stains, making it impossible to process. Additionally, the interior of the dyeing tank became dirty and required frequent cleaning.

Comparative Example 2 Except for not replenishing the dye concentrate and water at all,
The treatment was carried out in the same manner as in Example 1. In A of the figure, the absorbance is
The staining density decreased in both cases, and in B of the figure, the staining solution was concentrated due to evaporation, and tar was significantly generated.

Example 2 The processing area of a photosensitive lithographic printing plate that does not require dampening water was detected, and only when the processing amount was 4 m2 or more for 10 minutes of operation time, 3 ml of dye concentrate was added per 1 m2. Replenishment was performed, and if the amount was less than 4 m2, the water level sensor was used to control the amount of water to be replenished. Other than that, the process was carried out in the same manner as in Example 1. Although the absorbance decreased slightly as shown in FIG. 3B, all plates were stained well.

[0075]

[Effects of the Invention] The present invention improves the running properties by replenishing the staining solution with a concentrated solution, that is, suppressing the decrease in the staining solution concentration and the staining density in the image area, and also when water is replenished. can prevent the generation of tar in the staining solution.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a processing apparatus used in the processing method of the present invention.

FIG. 2 is a sectional view showing a liquid level detection sensor used as one of the detection methods.

FIG. 3 is a graph showing the relationship between throughput and absorbance. The dotted line indicates the amount of tar generated.

[Explanation of symbols]

1 Photosensitive planographic printing plate that does not require dampening water 11 Developer tank 12 Developer solution stock tank 13 Dilution water tank 14, 17 Washing tank 19 Over port 20 Waste liquid outlet 21, 22, 23 Brush roll 3 Roller 4 Guide plate 51, 52, 53, 54, 55, 56, 57, 58, 5
9, 60 Shower nozzle 61 Developer solution 62 Developer solution stock solution 63 Dilution water 64, 67 Washing water 65, 66 Staining solution 7 Carrying sensor 71 Filter 72 Bubble prevention plate 73, 731, 732, 733, 734 Pump 74
Filter 77 Liquid level sensor 771 Float 772, 773 Sensing part 774 Mandrel 8 Flow rate adjustment valve 81 Absorbance detector 91, 92, 93 Cover C Control device applicant Konica Corporation Patent attorney Mikio Nakajima

Claims (1)

[Claims] Claim 1: In a method for automatically transporting and processing a photosensitive lithographic printing plate that does not require dampening water after image exposure, in the dyeing step of the image area after the development step, the dyeing solution has a concentration higher than that of the dyeing solution. A method for processing a photosensitive lithographic printing plate that does not require dampening water and is characterized by replenishing a high-density dyeing solution.