JPH03105345A - Method for processing photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE:To prevent the fluctuation in the degree of dilution and to attain a stable development processing by measuring and managing the optical density of a developing soln. diluted from a thick developing soln. contg. dyes or optically detecting and controlling the mixing ratio to a dilute liquid. CONSTITUTION:The thick developing soln. composed of aq. solns. of sodium hydroxide, sodium silicate and sodium sulfite, benzoic acid, etc., and dyes, such as victoria pure blue BOH, is charged into a tank 15a of an automatic developing machine and is diluted with the water of a diluting water tank 15b and a mixing tank 4. The dilute soln. is supplied onto the surface of a PS plate via a developing soln. supplying member 6. The optical density of the diluted developing soln. is detected by a sensor 43 in a supplying tank 3. Fixed delivery pumps 16a, 16b are controlled to maintain the optical density when the detected value deviates by specified % or above from a regulated value. Thus, the processing stable at all times for several months is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for processing photosensitive lithographic printing plates, and more specifically, to a method for processing a photosensitive lithographic printing plate, and more specifically, it relates to a method for processing a photosensitive lithographic printing plate. Regarding how to reduce.

[Conventional technology]

Conventionally, photosensitive planographic printing plates (hereinafter referred to as P
When developing the S plate) with an alkaline developer containing water as the main solvent, the developer is repeatedly used.
The activity of the developer, which decreases during development, has been compensated for by adding replenisher, but the amount of replenisher may vary depending on the replenishment accuracy or the type of PS plate. There were variations in the quality of the finished TSP version. As a way to solve such problems,
1-243455 and Japanese Patent Laid-Open No. 62-42159, there is a method of carrying out development using a substantially unused developer.

However, in the above method, the operation of diluting the concentrated developer to create the developer is usually done automatically by sending both solutions through pipes and mixing them to form the developer. There was a problem in that the degree of dilution of the developing solution fluctuated due to dust adhering to the inside of the piping, resulting in variations in the quality of the finished PS plate.

[Purpose of the invention]

The present invention is intended to solve the above-mentioned technical problem, and an object of the present invention is to prevent fluctuations in the degree of dilution when a concentrated developer is automatically diluted and used, and to enable stable development processing.
An object of the present invention is to provide a method for developing an S plate.

[Structure of the invention]

To achieve the above object, the present invention provides a method for processing a photosensitive lithographic printing plate in which an automatic developing machine is used to supply a developer to the surface of each photosensitive lithographic printing plate for development. is characterized in that the concentrated developer from which it is prepared contains a dye.

Further, according to the present invention, a processing method includes controlling the degree of dilution of the concentrated developer by measuring the optical density of the diluted developer;
A method for detecting the mixing ratio of the concentrated developer containing a dye and optically detecting the mixing ratio of the concentrated developer and a diluted solution or another concentrated developer, and a concentrated developer containing the dye. A method for preparing a developer is provided, which detects the mixing ratio of a liquid and a diluted solution or other concentrated developer, and controls the mixing ratio or issues an alarm based on the detection result.

The present invention will be explained in detail below.

In the present invention, the dyes contained in the concentrated developer include dyes and pigments. Various types of dyes are known, and any of them can be used. Types of these dyes include azo dyes, anthraquinone dyes, indigo dyes, sulfur dyes, carbonium dyes, quinone imine dyes, phthalocyanine dyes, reactive dyes, fluorescent dyes, and cyanine dyes, among which carbonium dyes and quinone imine dyes are preferred. In particular, basic dyes are effective. Further structural classification is diphenylmethane dye, triphenylmethane dye, xanthene dye,
Thalein dyes, acridine dyes, azine dyes, oxazine dyes, thiazine dyes, etc. can be particularly preferably used. Specific examples of preferable dyes used in the present invention include:
Victoria Viewer Blue B O H, Victoria Blue BO, Victoria Viewer Blue 81 Years Old Il Blue #
603, crystal violet, methyl violet, patent viewer blue, ethyl violet, brilliant milling green B1 methyl green, brilliant green, malachite green, auramine, fuchsin, rhodamine B, etc. The dye is preferably one that is soluble in the target developer, but in some cases it may be in a dispersed state in the form of fine particles instead of in a dissolved state. Therefore, even pigments can be suitably used if they can be made into a good dispersion state. The content of dye in the developer is o. The range of o.oot to 5vt% is preferable, more preferably o.o.o.t. oi~Q. It is in the range of 5wt%.

The present invention is characterized in that when a concentrated developer contains a dye and is mixed with a diluted solution to form a developer, the mixing ratio is detected based on the concentration of the dye in the mixed solution. Therefore, the method can be applied to any developer and concentrated developer.

The developing solution and concentrated developer to which the method of the present invention can be applied include a negative-working PS plate developer using a diazo compound as a photosensitive block, and a positive-working PS plate developer using an 0-quinonediazide compound as a photosensitive block. and a common developer for the negative PS plate and the positive PS plate.

In the present invention, the concentrated developer (other than the diluted solution) may be composed of one solution or two or more solutions. In the case of two or more liquids, at least one of them may contain a dye, or each liquid may separately contain dyes having different spectral absorption characteristics.

A typical developer to which the present invention is applied is an alkaline developer containing water as a main solvent (50% by weight or more of the solvent in the developer is water). The developing solution may have the composition of a developer commonly used for developing a photosensitive lithographic printing plate containing an 0-quinonediazide compound or a diazo resin as a photosensitive component, and in addition to an alkaline agent, for example, an organic It can contain carboxylic acids and salts thereof, anionic, nonionic, and cationic surfactants, organic solvents, and the like.

Examples of the alkaline agents contained in the above developer include sodium silicate, potassium silicate, sodium/lium hydroxide, lithium hydroxide, tribasic sodium phosphate, dibasic sodium phosphate, tribasic potassium phosphate, Potassium phosphate, tribasic ammonium phosphate, dibasic ammonium phosphate, sodium metasilicate, sodium bicarbonate, sodium carbonate,
Useful are inorganic alkaline agents such as potassium carbonate, ammonium carbonate, etc., organic alkaline agents such as monogy or triethanolamine and tetraalkylammonium hydroxide, and organic ammonium silicates.

The content of the alkaline agent in the developer is at least 0.
It can range from 0.05 to 20% by weight.

The developer solution may contain a water-soluble or alkali-bathable organic and inorganic reducing agent.

Examples of organic reducing agents include phenolic compounds such as hydroquinone, methol, and methoxyquinone, and amine compounds such as phenylenediamine and phenylhydrazine. Examples of inorganic reducing agents include sodium sulfite, potassium sulfite, ammonium sulfite, Sulfites such as sodium hydrogen sulfite and potassium hydrogen sulfite, sodium phosphite, potassium phosphite, sodium hydrogen phosphite,
Examples include phosphates such as potassium hydrogen phosphite, sodium dihydrogen phosphite, and dipotassium hydrogen phosphite, hydrazine, sodium thiosulfate, and sodium dithionite.

These water-soluble or alkali-soluble reducing agents contain at least 0
．． It can be contained in an amount of 1 to 10% by weight.

The organic carboxylic acids include aliphatic carboxylic acids having 6 to 2 carbon atoms and aromatic carboxylic acids in which a benzene ring or a naphthalene ring is substituted with a carpoxyl group.

The aliphatic carboxylic acid is preferably an alkanoic acid having 6 to 2 carbon atoms, and specific examples include caproic acid, enantinoleic acid, caprinoleic acid, belargonic acid, cabric acid,
Examples include lauric acid, mystiric acid, valmitic acid, and stearic acid, and particularly preferred are alkanoic acids having 6 to 12 carbon atoms. Further, fatty acids having a double bond in the carbon chain or those having branched carbon chains may be used. The above aliphatic carboxylic acid may be used as a sodium, potassium or ammonium salt.

Specific compounds of aromatic carboxylic acids include benzoic acid, 0-chlorobenzoic acid, p-chlorobenzoic acid, 0-hydroxybenzoic acid, p-hydroxybenzoic acid, p-ter
t-butylbenzoic acid, 0-aminobenzoic acid, p-aminobenzoic acid, 2,4-dihydroxybenzoic acid, 2.5-dihydroxybenzoic acid, 2.6-dihydroxybenzoic acid,
2.3-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, gallic acid, ■-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 2-hydroxy-
These include 1-naphthoic acid, 1-naphthoic acid, 2-naphthoic acid, and the like.

The above-mentioned aromatic carboxylic acid may be used as a sodium or potassium salt or an ammonium salt.

The content of aliphatic carboxylic acid and aromatic carboxylic acid can be at least 0 to 30% by weight.

The above developer is anionic type, nonionic type, as shown below.
It can contain cationic surfactants and organic solvents.

Examples of anionic surfactants include higher alcohols (C.I.
~C,2) Sulfuric acid ester salts [e.g., sodium salt of lauryl alcohol sulfate, sodium salt of octyl alcohol sulfate, ammonium salt of laurinoleanoreconoresanolephate, rTeepo
l-81J (trade name, Shell Chemical Co., Ltd.), Sodium Sodium Alkyl Sulfate 1, etc. 1, Aliphatic Alcohol Phosphate Salts (e.g. Sodium Salt of Cetyl Alcohol Phosphate, etc.), Alkylaryl Sulfonate M (For example, the sodium salt of dodecylbenzenesulfonic acid, the sodium salt of isoprobylnaphthalenesulfonic acid,
- salts of dinaphthalene disulfonic acid, sodium salts of dinaphthalene disulfonic acid, sodium salts of metanilobenzene sulfonic acid), sulfonate salts of alkylamides (e.g., C,
ytl+ 3CON(CIl3)CH2SO3Na, etc.), sulfonic acid salts of dibasic fatty acid esters (e.g., sodium sulfosuccinate dioctyl ester,
Na1-lium sulfosuccinic acid dihexyl ester, etc.)
There is.

Among these, sulfonate salts are particularly preferably used.

As the nonionic surfactant, both polyethylene glycol type and polyhydric alcohol type can be included.

As a nonionic surfactant, for example, the following general formula (1
) to [8].

[l) R O (CI{zcHxo)nH [2] [3] C{1, R − 0-(CH.CHO)m − (CI+2CH
20) nH [4] [5] 0 [6] HO(C2H.O)a - (C.H40)b-(C2
H,O)ctl[7] H(OCzHa)y(OCxFIa)X\/(CJgO
)X (C2H40)yHH(OCztL)Y (
OC3Ha)x/\(C3H,O)x-(C2H40)
yH [8]? O (Cl■CH20)nil In the formulas [1] to [8], R represents a hydrogen atom or a valent organic group. The organic group includes, for example, a linear or branched alkyl group having 1 to 30 carbon atoms, which may have a substituent {for example, an aryl group (phenyl, etc.)}, and an alkylcarbonyl group in which the alkyl moiety is the above-mentioned alkyl group. and a phenyl group which may have a substituent (for example, a hydroxyl group, an alkyl group as described above, etc.). a
1b, c, m, n, x and y each represent an integer of 1-40.

Specific examples of nonionic surfactants are shown below.

Polyethylene glycol, polyoxyethylene lauryl ether, polyoxyethylene nonyl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene behenyl ether, polyoxyethylene polyoxypropylene cetyl ether Tenore,
Polyoxyethylene polyoxybrobylene behenyl ether, polyoxyethylene noninolephenyl ether, polyoxyethylene ethylene octyl phenyl ether, polyoxyethylene stearylamine, polyoxyethylene oleylamine, polyoxyethylene stearamide, polyoxyethylene Ethylene oleic acid amide, polyoxyethylene castor oil, polyoxyethylene abiethyl ether, polyoxyethylene lanolin ether, polyoxyethylene monolaurate, polyoxyethylene monostearate, polyoxyethylene glyceryl monooleate, polyoxyethylene glyceryl monooleate cell monostearate,
Polyoxyethylene propylene glycol monostearate, oxyethylene oxypropylene block polymer, distyrenated phenol polyethylene oxide adduct, tribenzylphenol polyethylene oxide adduct, octylphenol polyoxyethylene polymoxypropylene adduct, glycerol monostearate 1,
norbitan monolaure-1, polyoxyethylene monolaurate, etc.

The weight average molecular profit of nonionic surfactants is 300-10
A range of 000 is preferred. The concentration of nonionic surfactant in the developer solution can be at least 0.001-10% by weight.

Various cationic surfactants can be contained. Cationic surfactants are broadly classified into amine type and quaternary ammonium salt type, and any of these can be used in the present invention.

Examples of amine types include polyoxyethylenealkylamines, N-alkylpropyleneamines, N-alkylpolyethylenepolyamines, N-alkylpolyethylenepolyamine dimethyl sulfates, alkyl biguanides, long chain amine oxides, alkylimidazolines, l-hydroxyethyl amines, Examples include 2-anolequinoleimidazoline, (1)-acetylaminoethyl-2-alkylimidazoline, and 2-alkyl-4-methyl-4-hydroquinemethyloxazoline.

Examples of quaternary ammonium salts include long chain l amine salts, alkyltrimethylammonium salts, dialkyldimethylethylammonium salts, alkyldimethylammonium salts, alkyldimethylpendylammonium salts, alkylpyridinium salts, and alkylquinolinium salts. salt, alkylisoquinolinium salt, alkylviridinium sulfate, stearamidemethylviridinium salt, acylaminoethynolediethynoleamine salt, acylaminoethynolemethyldiethylammonium salt, alkylamidobrobyl dimethylbenzylammonium salt, fatty acid polyethylene polyamide, acinoleaminoethynoleviridinium salt, acylcolaminoformylmethylpyridinium salt,
Stearooxymethyl viridinium salt, fatty acid triethanolamine, fatty acid triethanolamine formate, trioxyethylene fatty acid triethanolamine, fatty acid dibutylaminoethanol, cetyloxymethyl viridinium salt, p-cutylphenoxyethoxyethyl There are dimethylbenzylammonium salts, etc. ("Alkyl" in the above compound examples refers to a straight chain or partially substituted alkyl having 6 to 20 carbon atoms, specifically,
Straight chain alkyls such as hexyl, octyl, cetyl, stearyl and the like are preferably used. ) It is also possible to contain a polymeric cationic surfactant having a cationic component as a repeating unit, such as a polymer containing a quaternary ammonium salt obtained by copolymerizing with a lipophilic heptanomer.

The amount of cationic surfactant added to the developer solution can range from at least 0.001 to LO weight percent.

Moreover, those having a weight average molecular weight of at least 300 to 50,000 can be used.

As an organic solvent, the solubility in water at 20°C is I.
0% by weight or less, such as ethyl acetate, probyl acetate, butyl acetate, benzyl acetate, ethylene glycol monobutylacetate, butyl lactate, butyl leprinate; ethyl butyl ketone, methyl isobutyl ketone. , ketones such as nclohexanone; ethylene glycol monobutyl ether,
Alcohols such as ethylene glycol benzyl ether, ethylene glycol mono-7enyl ether, benzyl alcohol, methyl 7-enyl carbinol, n-, amyl alcohol, methyl amyl alcohol; alkyl-substituted aromatic hydrocarbons such as xylene; methylene dichloride, Examples include halogenated hydrocarbons such as ethylene dichloride and monochlorobenzene. One or more types of these organic solvents may be used.

The following additives can be added to the above-mentioned developer in order to improve development performance. For example, JP-A-58-751
Neutral salts such as NaCf2 and KCl21KBr described in JP-A No. 52, EDT described in JP-A-59-190952
A. , Chelating agents such as NTA, JP-A-59-1213
Complexes such as (Co(N's)3acI2) described in No. 36, ampholytic polymer electrolytes such as the copolymer of nohinylpenzyltrimethylammonium chloride and sodium acrylate described in JP-A-56-142528, and Kaisho 5
Inorganic lithium compounds such as lithium chloride described in Japanese Patent Publication No. 8-59444, organic lithium compounds such as lithium benzoate described in Japanese Patent Publication No. 50-34442, JP-A-59-7
The pH of the above-mentioned developer may be in the range of 12 to 13.5, including the organometallic surfactant containing Si, Ti, etc. described in JP-A-5255, and the organoboron compound described in JP-A-59-84241. can.

In the present invention, it is preferable that the developer is a negative/positive developer, since the effect of the present invention is greater. Specific examples of the developer include JP-A-62-24263;
No. 62-24264, No. 62-25761, No. 62
-35351, 62-75535, 62-39
No. 060, No. 62-125357, No. 62-1334
No. 60, No. 62-159148, No. 62-16816
No. 0, No. 62-175758, No. 63-200154
Examples include developers described in No. 63-205658 and various publications.

The concentrated developer containing the dye according to the present invention is a developer having a higher concentration than the developer (used solution), preferably 2 to IO times the concentration, more preferably 3 to 8 times the concentration of the used solution.

Furthermore, in the present invention, the diluent is preferably water.

Preferably, the apparatus for carrying out the method of the present invention has a sensor for detecting the concentration of the diluted developer in the developer dilution tank or the subsequent developer supply tank or piping. It is preferable to use a transmission type densitometer as the detection device, and it is also preferable to incorporate the detection device into the main body of the automatic processor.

〔Example〕

EXAMPLES Hereinafter, the present invention will be explained in detail with reference to Examples, but the present invention is not limited thereto.

In the following Examples and Comparative Examples, an automatic developing machine shown in FIG. 1 and FIG. 2 (both schematic sectional views) was used. 1st
In the figure, IO is a developing section, 20 is a water washing section, 30 is a rinse/gum section that performs treatment with a rinsing liquid or a desensitizing liquid, and PS is a PS plate. 1, 24, 34
1 is a transport roller that nip and transport the PS plate, 2 is a press roller for stabilizing the transport position of the PS plate, 3 is a developer supply tank, 4 is a developer mixing tank, 5 is a developer supply pipe, 6 is a developer supply member for uniformly supplying the developer onto the PS plate, 7 is a roller that supports the lower end of the developer supply member 6 and the PS plate, 8 is a developer tank, 9 is a guide roller, 11, 25 , 35 is a squeeze roller, 14 is a rotating brush, 15a is a concentrated developer tank, 15b is a concentrated developer dilution water tank, 16a, 16b, 18 is a metering bomb, 19 is a solenoid valve, 2l is a washing water tank, 13, 23A
．． 23B 33 is a shower nozzle, 3L is a rinse/gum liquid tank that holds rinse liquid or desensitizing liquid, 40
numeral 41 and 42 are pump control sections, and 43 is an optical density detection sensor.

In the diagram, *l and *l1 *2 and *2, *3 and *3, *4 and *
4 and are connected by piping, respectively.

The automatic developing machine shown in FIG.
Input to the alarm device control unit 45 instead of 0 and enter the alarm device 46
The structure is the same as that of the automatic developing machine shown in FIG. 1 except that the developing machine is operated.

Example 1 The following concentrated developer was charged into the concentrated developer tank 15a of the automatic processor shown in FIG.

Pure water
400g benzyl alcohol
3g propylene glycol
30g benzoic acid 80
g50% sodium hydroxide aqueous solution 200g Emanoregen A-500 3
g (manufactured by Kao Corporation, nonionic surfactant) sodium 1.lium silicate aqueous solution 190 g (JIS standard sodium silicate No. 3) 40% sodium sulfite aqueous solution 320 g Victoria Viewer Blue B O H 1.5
g (manufactured by Hodogaya Chemical Co., Ltd., dye) When this concentrated developer was diluted 6 times with water, the pH was 13.
It was 0.

Next, 154 liters of water was added to 2 liters of rinse water, and 1012 liters of SGW-2 (gum liquid manufactured by Konica Corporation) was mixed with water at a ratio of 1:1 to 3 liters of rinse gum liquid. is.

The concentrated developer is diluted six times with water in the developer mixing tank 4 and supplied onto the PS plate surface via the developer supply member 6. At this time, the optical density of the diluted developer is It is detected by a sensor 43 installed in the supply tank 3, and if the value deviates by 8% or more from the specified value, the metering pumps 16a and 16b are controlled to adjust the optical density of the developer. I tried to return it to the specified concentration. The temperature of the developer solution in the developer supply member 6 and developer tank 8 was set to 27°C. Further, the developer tank 17 was charged with 512 ml of the above-mentioned concentrated developer diluted 6 times with water.

Under these conditions, negative type PS version SWN and positive type P
S version SMP-N (all manufactured by Konica Corporation) at 1:l
Processing was carried out at a rate of 100 copies per day for 3 months (5 days 1 week, 13 weeks). In addition, the developer in the developer tank 17 should be used once every two weeks, the washing water should be washed every day, and the gum solution should be filled with 50% PS plate.
The developer solution in the developer tank 8 was replaced every day after each 01 processing. In addition, Nyawar nozzles 13, 2
3a, 23b. 33 is installed once a week in each processing liquid tank (
17, 21. 31) was designed to be cleaned when replacing the internal liquid.

As a result, we were able to perform stable treatment for three months. Further, when the obtained lithographic printing plates were sampled every 500 plates and printed, good printed matter was obtained.

Comparative Example In the automatic developing machine shown in FIG. The same experiment as in Example 1 was conducted except that the function of 42 was stopped. When printing was performed using the lithographic printing plate obtained in the third month (6,500 plates), scumming occurred in the non-image area.

Example 2 An experiment similar to Example 1 was conducted except that the automatic developing machine shown in FIG. 2 was used.

As a result, when I tried to process the 6250th PS plate, an alarm went off, so I temporarily stopped the development process and turned off the fixed amount bomb 1.
After cleaning the insides of 6a and 16b, the development process was restarted. After that, stable processing was possible.

〔Effect of the invention〕

According to the present invention, it is possible to reduce fluctuations in the degree of dilution when a concentrated developer is automatically diluted and used, and stable development processing can be performed.

[Brief explanation of drawings]

1 and 2 are schematic sectional views showing an example of an automatic developing machine used in the method of the present invention. 3...Developer supply tank 4...Developer mixing tank 6...Developer supply member 8...Developer tank 15a...Concentrated developer tank 15b...Concentrated developer dilution water tank 16a, 16b, 18 - Metering pumps 40, 44...
- Arithmetic unit 4L42...Pump control unit 43...Concentration detection sensor 45...Alarm device control unit 46...Alarm device

Claims (4)

[Claims] (1) Using an automatic developing machine, apply developer to photosensitive planographic printing plate 1.
1. A method for processing a photosensitive lithographic printing plate in which a concentrated developer from which the developer is prepared contains a dye, in a method for processing a photosensitive lithographic printing plate in which the plate surface is supplied and developed sheet by sheet. (2) The processing method according to claim 1, wherein the degree of dilution of the concentrated developer is controlled by measuring the optical density of the diluted developer. (3) A method for detecting a mixing ratio, which comprises making a concentrated developer contain a dye and optically detecting the mixing ratio between the concentrated developer and a diluted solution or another concentrated developer. (4) The feature is that a dye is contained in a concentrated developer, the mixing ratio of the concentrated developer and a diluted solution or another concentrated developer is detected, and the mixing ratio is controlled or an alarm is issued based on the detection result. How to prepare a developer solution.