JPH09274324A - Treatment of photosensitive planographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the method for treating a photosensitive planographic printing plate by which insoluble matter is hardly stuck to a sensor or the like for measuring the electrical conductivity or impedance of developer and extremely stabilized treatment is performed over a long period. SOLUTION: The photosensitive planographic printing plate is developed by using the developer which contains at least one kind of weak acid and at least one kind of chlorine having an acid dissociation constant (pKa) 10.0-13.3 and whose pH is within 9.0-13.9, and the deterioration of the activity of the developer is detected by measuring the electrical conductivity or the impedance of the developer, and developing replenishing liquid is replenished so as to maintain the activity constant based on a detected result.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a processing method for a photosensitive lithographic printing plate, and more particularly to a processing method for a photosensitive lithographic printing plate having improved development stability.

[0002]

2. Description of the Related Art Conventionally widely used positive-working photosensitive lithographic printing plates are provided on an aluminum plate as a support.
-A photosensitive layer made of a quinonediazide compound is provided. It is known that an o-quinonediazide compound is converted into a carboxylic acid upon exposure to ultraviolet light. Therefore, when the o-quinonediazide compound is developed with an aqueous alkali solution, only the exposed portion of the photosensitive layer is removed and the surface of the support is exposed. Since the surface of the aluminum support is hydrophilic, a portion (non-image portion) where the surface of the support is exposed by development retains water and repels oil-based ink. On the other hand, the area (image area) where the photosensitive layer has not been removed by the development is lipophilic and thus repels water and receives ink.

Photosensitive layer of these positive-working photosensitive lithographic printing plates
Is a binder of the above o-quinonediazide compound (hereinafter
Usually called cresol novolac as binder)
Resins have been used. Therefore, as a developer,
Strong enough to dissolve resol novolak resin around pH 13.
It was common to use alkaline silicates. Or
Used as a developer for a positive-working photosensitive lithographic printing plate
A variety of alkaline aqueous solutions are known, but most are
Sodium silicate and potassium silicate are commonly used.
An aqueous solution of silicate such as um. The reason is the component of silicate
Silicon oxide SiO_TwoAnd alkali metal oxide M_TwoO's
Ratio (generally [SiO_Two] / [M_TwoO _Two] Molar ratio
It is possible to adjust the developability to some extent depending on the
That's because. In addition, almost all positive photosensitive lithographic plates
The printing plate requires a strong alkali of around pH 13 for development,
The silicate has a good buffering effect in its pH range and is stable.
This is because it can be developed.

These silicates are not limited to the above-mentioned positive-working photosensitive lithographic printing plates, but also reverse type negative-working photosensitive lithographic printing plates using an o-quinonediazide photosensitive layer described in JP-B-56-14970 and alkalis. Negative-type photosensitive lithographic printing plate developer using a soluble diazonium salt as a photosensitive layer, and development of a negative-type photosensitive lithographic printing plate using a photosensitive layer containing a resin having a side chain of a dimethylmaleimide group as a photocrosslinking agent It has also been used as a liquid, particularly as a common processing developer for negative-type and positive-type photosensitive lithographic printing plates.

In recent years, automatic developing machines for photosensitive lithographic printing plates have been widely used in the plate making / printing industry in order to rationalize and standardize the plate making work. This automatic developing machine is generally composed of a device for conveying a photosensitive lithographic printing plate, a developing solution tank and a spraying device, and while conveying the exposed photosensitive lithographic printing plate horizontally, the developer pumped up by a pump is used. Spray
It is developed by spraying from a nozzle. Also,
Recently, a method has also been known in which a photosensitive lithographic printing plate is immersed and conveyed in a developing treatment tank filled with a developing solution by means of a submerged guide roll or the like to perform a developing treatment.

When a positive photosensitive lithographic printing plate is developed using such an automatic processor, SiO ₂ /
The molar ratio of Na ₂ O is 1.0 to 1.5 (ie [SiO ₂ ].
/ [Na ₂ O] is 1.0 to 1.5) and SiO ₂
Is used, and the molar ratio of SiO ₂ / Na ₂ O is 0 continuously or intermittently depending on the throughput of the positive-working photosensitive lithographic printing plate. By adding an aqueous solution of sodium silicate (replenisher) of 0.5 to 1.5 (that is, [SiO ₂ ] / [Na ₂ O] of 0.5 to 1.5) to the developer, the developer in the tank for a long time is added. JP-A-54-62004 discloses that a large amount of positive-working photosensitive lithographic printing plates can be processed without exchanging them.

Further, Japanese Patent Publication No. 57-7427 discloses
[SiO ₂ ] / [M] is 0.5 to 0.75 (that is, [S
iO ₂ ] / [M ₂ O] is 1.0 to 1.5), and S
Using an alkali metal silicate developer having an iO ₂ concentration of 1 to 4% by weight, [SiO ₂ ] / [M] of the alkali metal silicate used as a replenisher is 0.25 to 0.75 (that is, [SiO ₂ ] / [M ₂ O] is 0.5 to 1.5), and both the developer and the replenisher are at least based on gram atoms of all alkali metals present therein. A development method is disclosed which comprises containing 20% potassium.

However, the silicate, which is the main component of the developing solution, is stable in the alkaline region, but when it is neutral, it gelates and becomes insoluble, and when it is evaporated to dryness, it is only a strong acid such as hydrofluoric acid. It has the drawback of not melting. Actually, the actual damages are stains of the solidified product due to liquid splash around the developing tank of the automatic developing machine, precipitation of insoluble products due to neutralization when discarding the developing waste liquid, and the like.

Japanese Unexamined Patent Publication (Kokai) No. 58-95349 is provided with a sensor for electrically measuring the elution degree of the photosensitive layer in the non-image area of the photosensitive plate. When the elution degree drops to a predetermined level, a developing replenisher solution is provided. Are disclosed. When the developing solution is a silicate type, insoluble matter of silicate is deposited on this sensor and the detection sensitivity is lowered, so that normal replenishment cannot be performed and there is a problem that processing stability is significantly reduced.

Japanese Unexamined Patent Publication No. 64-21451 discloses a method of measuring the AC impedance of a developing solution with a sensor and replenishing the replenishing solution when the measured value reaches a predetermined value. Also in the method, there is a problem that the insolubilized silicate is deposited on the sensor and the detection sensitivity is lowered, so that the replenishment becomes excessive and the stability of the treatment is significantly lowered.

In order to solve this problem, it has been attempted to use an alkaline agent other than silicate in a developer for a positive type photosensitive lithographic printing plate, and a strong combination of trisodium phosphate and a combination of sodium hydroxide and trisodium phosphate. Alkali was evaluated as a developer, but the buffer action was weak in all cases, and stable development was not possible.

[0012]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to prevent insoluble matter from adhering to a sensor or the like for measuring the electric conductivity or impedance of a developing solution, and to perform extremely stable processing for a long period of time. Another object of the present invention is to provide a method for processing a photosensitive lithographic printing plate that can be used.

[0013]

Means for Solving the Problems As a result of intensive studies conducted by the present inventors in order to achieve the above object, a buffer solution in which a weak acid such as a saccharide and a base are combined is extremely useful for developing a photosensitive lithographic printing plate. The present invention has been made, and further, the inventors have found that the developing solution and the developing replenishing solution containing the buffer solution as a main component do not generate insoluble matter in the above-mentioned sensor or the like, and have completed the present invention.

That is, according to the present invention, the acid dissociation constant (pKa) 1
PH of 9.0 to 1 containing at least one weak acid having 0.0 to 13.3 and at least one base
The photosensitive lithographic printing plate is developed using a developer in the range of 3.9, and deterioration of the activity of the developer is detected by measuring the conductivity or impedance of the developer, and the detection is performed. A method of processing a photosensitive lithographic printing plate, which comprises replenishing a developing replenisher so as to keep the activity constant based on the result, wherein at least one saccharide and at least one base selected from non-reducing sugars. The photosensitive lithographic printing plate is developed using a developer having a pH in the range of 9.0 to 13/9, and deterioration of the activity of the developer is caused by the conductivity or impedance of the developer. The method for processing a photosensitive lithographic printing plate is characterized in that the development replenisher is replenished so as to keep the activity constant based on the detection result.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

[0016]

[Developer]

[0017]

[Alkaline agent] The developing solution and the developing replenisher used in the present invention contain, as a main component, a buffer solution having a buffering action in the alkaline region, which comprises at least one weak acid and at least one strong base, and has a pH of 9. It is in the range of 0 to 13.9. As the weak acid used as the buffer solution, those having a dissociation constant (pKa) of 10.0 to 13.3 are preferable, and those having a pKa of 11.0 to 13.2 are more preferable.
Those of 2.0 to 13.2 are preferable.

Examples of such a weak acid include Pergamo.
IONISION CONS issued by nPress
TANTS OF ORGANIC ACIDS IN
It is selected from those described in AQUEOUS SOLUTION and the like, for example, 2,2,3,3-tetrafluoropropanol-1 (pKa 12.74), trifluoroethanol (12.37), trichloroethanol (12.13). 24) and other alcohols, pyridine-
Aldehydes such as 2-aldehyde (the same 12.68), pyridine-4-aldehyde (the same 12.05), salicylic acid (the same 13.0), 3-hydroxy-2-naphthoic acid (the same 12.84), Catechol (12.6), gallic acid (12.4), sulfosalicylic acid (11.7),
3,4-dihydrosisulfonic acid (12.2), 3,
4-dihydroxybenzoic acid (11.94), 1,2,
4-trihydroxybenzene (11.82), hydroquinone (11.56), and pyrogallol (11.82).
34), o-cresol (the same 10.33), resorsonol (the same 11.27), p-cresol (the same 10.2).
7), a compound having a phenolic hydroxyl group such as m-cresol (id. 10.09), sorbit (id.
0), sucrose (12.7), glucose (1)
2.46), galactose (12.35), arabinose (12.34), xylose (12.29),
Fructose (same 12.27), ribose (same 12.2)
2), sugars such as mannose (12.08) and L-ascorbic acid (11.34), 2-butanone oxime (12.45), acetoxime (12.42),
1,2-cycloheptanedionethioxime (12.
3), 2-hydroxybenzaldehyde oxime (the same 1
2.10), dimethylglyoxime (11.9), ethanediamidedioxime (11.37), acetophenone oxime (11.35), and other oximes, adenosine (12.56), and inosine (same). 12.5), guanine (12.3), cytosine (12.2), hypoxanthine (12.1), xanthine (11.9).
In addition to nucleic acid-related substances such as diethylaminomethylphosphonic acid (12.32), 1-amino-3,3,3-trifluorobenzoic acid (12.29), isopropylidenediphosphonic acid (12.10). ), 1,1-ethylidene diphosphonic acid (the same 11.54), 1,1-ethylidene diphosphonic acid 1-hydroxy (the same 11.52), benzimidazole (the same 12.86), thiobenzamide (the same 1).
2.8), picoline thioamide (the same 12.55), barbituric acid (the same 12.5) and the like.

Among these weak acids, saccharides are preferable because they are relatively inexpensive, and among the saccharides, non-reducing sugars are particularly preferable because they are stable in alkali. Such a non-reducing sugar is a saccharide that does not have a free aldehyde group or a ketone group and does not exhibit reducing properties, and is a trehalose-type oligosaccharide in which reducing groups are bound to each other, or a glycoside in which a reducing group of a saccharide and a non-saccharide are bound to each other. It is classified into sugar alcohols obtained by hydrogenating the body and saccharides, and any of them is preferably used in the present invention. Trehalose-type oligosaccharides include saccharose and trehalose, and examples of glycosides include alkyl glycosides, phenol glycosides, and mustard oil glycosides. Further, sugar alcohols include D, L-arabite, rebite, xylit, D, L-sorbit,
Examples thereof include D, L-mannite, D, L-idit, D, L-talit, zuricit, and alodulcit. Furthermore, maltitol obtained by hydrogenation of disaccharides and reductants obtained by hydrogenation of oligosaccharides (reduced starch syrup)
Is preferably used. Among these, preferred non-reducing sugars in the present invention are sugar alcohols and saccharose, and especially D-
Sorbit, sucrose, and reduced starch syrup are preferable because they have a buffering action in an appropriate pH range and are inexpensive.

These weak acids and non-reducing sugars can be used alone or in combination of two or more, and their proportion in the developing solution is preferably 0.1 to 30% by weight, more preferably 1 to 20% by weight. %. If it is below this range, a sufficient buffering effect cannot be obtained, and if it is above this range, it is difficult to highly concentrate it, and there is a problem of cost increase. As the base which is the other component of the buffer solution, a conventionally known alkaline agent can be used. For example, sodium hydroxide, potassium, lithium, trisodium phosphate, potassium, ammonium, disodium phosphate, potassium, ammonium, sodium carbonate, potassium, ammonium, sodium hydrogencarbonate, potassium, ammonium And inorganic alkali agents such as sodium borate, potassium and ammonium. Further, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, Organic alkaline agents such as ethyleneimine, ethylenediamine, pyridine and tetramethylammonium hydroxide are also used supplementarily.

These alkaline agents may be used alone or in combination of two or more. Among these, sodium hydroxide and potassium hydroxide are preferred. The reason is,
This is because the pH can be adjusted in a wide pH range by adjusting the amounts of the weak acid and the non-reducing sugar. Trisodium phosphate, potassium phosphate, sodium carbonate, potassium phosphate, and the like are also preferable because they have a buffering action.

These alkaline agents increase the pH of the developer to 9.
It is added so as to be in the range of 0 to 13.9, and its addition amount is determined depending on the desired pH, the type of non-reducing sugar and the addition amount, and a more preferable pH range is 10.0 to 13.8.

[0023]

[Surfactant] The developer and development replenisher used in the present invention may contain various surfactants as necessary for the purpose of accelerating the developability, dispersing the development residue and enhancing the ink affinity of the image portion of the printing plate. Organic solvents can be added. Preferred surfactants include anionic, cationic, nonionic and amphoteric surfactants.

Preferred examples of the surfactant include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, and glycerin fatty acid partial esters. , Sorbitan fatty acid partial esters,
Pentaerythritol fatty acid partial ester, propylene glycol monofatty acid ester, sucrose fatty acid partial ester, polyoxyethylene sorbitan fatty acid partial ester, polyoxyethylene sorbitol fatty acid partial ester, polyethylene glycol fatty acid ester, polyglycerin fatty acid partial ester , Polyoxyethylenated castor oil, polyoxyethylene glycerin fatty acid partial ester, fatty acid diethanolamide,
Nonionic surfactants such as N, N-bis-2-hydroxyalkylamines, polyoxyethylenealkylamines, triethanolamine fatty acid esters, and trialkylamine oxides, fatty acid salts, abietic acid salts,
Hydroxyalkane sulfonates, alkane sulfonates, dialkylsulfosuccinate ester salts, linear alkylbenzene sulfonates, branched chain alkylbenzene sulfonates, alkylnaphthalene sulfonates, alkylphenoxypolyoxyethylenepropyl sulfonates, polyoxy Ethylene alkyl sulfophenyl ether salts, N-methyl-N-oleyl taurine sodium salt, N-alkyl sulfosuccinic acid monoamide disodium salt, petroleum sulfonates, sulfated tallow oil, sulfate ester salts of fatty acid alkyl esters, alkyl sulfate esters Salts, polyoxyethylene alkyl ether sulfate ester salts, fatty acid monoglyceride sulfate ester salts, polyoxyethylene alkylphenyl ether sulfate ester salts, Oxyethylene styryl phenyl ether sulfate ester salts, alkyl phosphate ester salts, polyoxyethylene alkyl ether phosphate ester salts, polyoxyethylene alkylphenyl ether phosphate ester salts, partial saponification products of styrene / maleic anhydride copolymers, Partial saponification products of olefin / maleic anhydride copolymers, anionic surfactants such as naphthalene sulfonate formalin condensates, alkylamine salts, quaternary ammonium salts such as tetrabutylammonium bromide, polyoxyethylene alkylamines Examples include cationic surfactants such as salts and polyethylene polyamine derivatives, and amphoteric surfactants such as carboxybetaines, aminocarboxylic acids, sulfobetaines, aminosulfates, and imidazolines. . Among the surfactants listed above, those with polyoxyethylene are
It can be read as a polyoxyalkylene such as polyoxymethylene, polyoxypropylene, and polyoxybutylene, and their surfactants are also included.

A more preferred surfactant is a fluorinated surfactant containing a perfluoroalkyl group in the molecule. Such fluorosurfactants include perfluoroalkyl carboxylate, perfluoroalkyl sulfonate, anionic type such as perfluoroalkyl phosphate, amphoteric type such as perfluoroalkyl betaine,
Cationic type and perfluoroalkylamine oxide such as perfluoroalkyltrimethylammonium salt, perfluoroalkylethylene oxide adduct, perfluoroalkyl group- and hydrophilic group-containing oligomer,
Non-ionic types such as oligomers containing perfluoroalkyl groups and lipophilic groups, oligomers containing perfluoroalkyl groups, hydrophilic groups and lipophilic groups, and urethanes containing perfluoroalkyl groups and lipophilic groups are included.

The above-mentioned surfactants can be used alone or in combination of two or more, and can be used in a developing solution in an amount of 0.
It is added in the range of 001 to 10% by weight, more preferably 0.01 to 5% by weight.

[0027]

[Development Stabilizer] Various development stabilizers are used in the developer and the development replenisher used in the present invention. Preferred examples thereof include polyethylene glycol adducts of sugar alcohols described in JP-A-6-282079, tetraalkylammonium salts such as tetrabutylammonium hydroxide, phosphonium salts such as tetrabutylphosphonium bromide, and iodonium such as diphenyliodonium chloride. Salts are mentioned as preferred examples.

Furthermore, anionic or amphoteric surfactants described in JP-A-50-51324, water-soluble cationic polymers described in JP-A-55-95946, and JP-A-56-142528. There are water-soluble amphoteric polyelectrolytes described in the publication. Furthermore, an alkylene glycol-added organoboron compound described in JP-A-59-84241, a polyoxyethylene / polyoxypropylene block polymerization type water-soluble surfactant described in JP-A-60-111246, 60-60
Alkylenediamine compounds substituted with polyoxyethylene / polyoxypropylene described in Japanese Patent Publication No. 9750, JP-A-Sho 6
Polyethylene glycol having a weight average molecular weight of 300 or more as described in JP-A 1-215554, JP-A-63-17585.
No. 8, a fluorine-containing surfactant having a cationic group,
4 in the acid or alcohol disclosed in JP-A-2-39157
Water-soluble ethylene oxide addition compound obtained by adding more than ethylene oxide, triethanolamine,
Examples thereof include water-soluble polyalkylene compounds obtained by adding ethylene oxide and / or propylene oxide to amines such as ethylenediamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine.

[0029]

[Organic solvent] If necessary, an organic solvent may be added to the developing solution and the developing replenishing solution. As such an organic solvent, those having a solubility in water of about 10% by weight or less are suitable, and preferably selected from those having a solubility of 5% by weight or less. For example, 1-phenylethanol, 2-phenylethanol, 3-phenyl-1-propanol, 4-phenyl-
1-butanol, 4-phenyl-2-butanol, 2-
Phenyl-1-butanol, 2-phenoxyethanol, 2-benzyloxyethanol, o-methoxybenzyl alcohol, m-methoxybenzyl alcohol, p
-Methoxybenzyl alcohol, benzyl alcohol,
Cyclohexanol, 2-methylcyclohexanol,
3-methylcyclohexanol and 4-methylcyclohexanol, N-phenylethanolamine and N
-Phenyldiethanolamine and the like can be mentioned. The content of organic solvent is 0.1 based on the total weight of the liquid used.
~ 5% by weight. The amount used is closely related to the amount used of the surfactant, and it is preferable to increase the amount of the surfactant as the amount of the organic solvent increases. This is because when the amount of the surfactant is small and the amount of the organic solvent is large, the organic solvent is not completely dissolved, and therefore, it is impossible to expect good developing property.

[0030]

[Reducing Agent] A reducing agent is further added to the developing solution and the developing replenishing solution used in the present invention. This prevents stains on the printing plate and is particularly effective when developing a negative photosensitive lithographic printing plate containing a photosensitive diazonium salt compound. Preferred organic reducing agents include phenolic compounds such as thiosalicylic acid, hydroquinone, metol, methoxyquinone, resorcin, and 2-methylresorcin; and amine compounds such as phenylenediamine and phenylhydrazine. Further preferred inorganic reducing agents include sodium salts, potassium salts, and ammonium salts of inorganic acids such as sulfurous acid, bisulfite, phosphorous acid, bisulfite, diphosphite, thiosulfate and dithionite. Salts and the like can be mentioned. Among these reducing agents, sulfites are particularly excellent in the stain prevention effect. These reducing agents are preferably used in a developing solution at the time of use.
It is contained in the range of 0.5 to 5% by weight.

[0031]

[Organic carboxylic acid] An organic carboxylic acid may be further added to the developing solution and the developing replenishing solution used in the present invention. Preferred organic carboxylic acids are aliphatic carboxylic acids having 6 to 20 carbon atoms and aromatic carboxylic acids. Specific examples of the aliphatic carboxylic acid include caproic acid, enantiic acid, caprylic acid, lauric acid, myristic acid, palmitic acid and stearic acid, and particularly preferred are alkanoic acids having 8 to 12 carbon atoms. . In addition, unsaturated fatty acids having a double bond in the carbon chain or branched fatty acids may be used.

The aromatic carboxylic acid is a compound in which a benzene ring, a naphthalene ring, an anthracene ring or the like is substituted with a carboxyl group, and specifically, o-chlorobenzoic acid,
p-chlorobenzoic acid, o-hydroxybenzoic acid, p-hydroxybenzoic acid, o-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, 1-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 2-hydroxy-1-naphthoic acid, 1-naphthoic acid , 2-naphthoic acid, etc., but hydroxynaphthoic acid is particularly effective.

The above aliphatic and aromatic carboxylic acids are preferably used in the form of sodium salt, potassium salt or ammonium salt in order to enhance water solubility. The content of the organic carboxylic acid in the developer used in the present invention is not particularly limited, but if it is lower than 0.1% by weight, the effect is not sufficient.
If it is 0% by weight or more, not only the effect cannot be further improved but also dissolution may be hindered when another additive is used in combination. Therefore, the preferable addition amount is 0.1 to 10% by weight with respect to the developing solution at the time of use, and more preferably 0.5 to
4% by weight.

[0034]

Others The developer and replenisher used in the present invention may further contain a preservative, a colorant, a thickener, a defoaming agent, a water softener and the like, if necessary. Examples of the preservative include the compound according to claim 1 of Japanese Patent Application No. 6-263552, benzoic acid, sodium benzoate, sorbic acid, sodium sorbate, potassium sorbate, isobutyl p-oxybenzoate, p. -Isopropyl oxybenzoate, methyl p-oxybenzoate, p-
Ethyl oxybenzoate, propyl p-oxybenzoate,
Butyl p-oxybenzoate, dehydroacetic acid, sodium dehydroacetate, sodium propionate, diphenyl, o-phenylphenol, sodium o-phenylphenol, thiabendazole, hydrogen peroxide, sodium hypochlorite, p-chloro-m-cresol , Stearyldimethylbenzylammonium chloride, 2-octyl-
4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-
Isothiazolin-3-one, 4,5-dichloro-2-n
-Octyl-4-isothiazolin-3-one, (2,2
-Dihydroxy-5,5-dichloro) diphenylmethane, allylmethanol halogen alkylacylaminomethanol, N- (2-hydroxypropyl) aminomethanol, 2-bromo-2-nitro-1.3-propanediol, 2,2-dibromo -2-nitroethanol,
1,2-benzisothiazolin-3-one, tetrachloroisophthalonitrile, 2- (4-thiazolyl) benzimidazole and the like are mentioned as preferable specific examples.

As the defoaming agent, for example, JP-A-2-244
Mineral oils, vegetable oils, surfactants, silicones and the like described in Japanese Patent No. 143 publication are listed. Examples of water softeners include polyphosphoric acid and its sodium, potassium, and ammonium salts, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraminehexaacetic acid, hydroxyethylethylenediaminetriacetic acid, nitrilotriacetic acid, 1,2-diaminocyclohexanetetraacetic acid. Aminopolycarboxylic acids such as acetic acid and 1,3-diamino-2-propanoltetraacetic acid and their sodium, potassium and ammonium salts, aminotri (methylenephosphonic acid), ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylene Phosphonic acid), triethylenetetraminehexa (methylenephosphonic acid), hydroxyethylethylenediaminetri (methylenephosphonic acid) and - hydroxyethane-1,1-diphosphonic acid and their sodium salts, potassium salts and ammonium salts.

The optimum amount of such a water softener to be added varies depending on the chelating power, the hardness of the hard water used and the amount of hard water. The content of the liquid is 0.01 to 5% by weight, and more preferably 0.01 to 0.5% by weight. If the added amount is less than this range, the intended purpose is not sufficiently achieved, and if the added amount is more than this range, adverse effects on the image area such as color omission appear.

The remaining component of the developer and developer replenisher is water. It is advantageous in terms of transportation that the developing solution and the developing replenishing solution used in the present invention are concentrated solutions in which the content of water is smaller than that at the time of use and are diluted with water at the time of use. The degree of concentration in this case is suitably such that each component does not cause separation or precipitation.

Further, it is supplied in the form of powder, granules or tablets,
It is preferable for transportation to dilute with water before use.

[0039]

[Photosensitive composition] Photosensitive lithographic printing plate (hereinafter referred to as PS plate) developed using the developer and the development replenisher of the present invention.
As a positive type P using an o-quinonediazide photosensitive layer
S plate, an inversion-type negative PS plate using an o-quinonediazide photosensitive layer, a negative PS plate using an alkali-soluble diazonium salt in the photosensitive layer, and a resin containing a dimethylmaleimide group as a side chain as a photocrosslinking agent Negative PS using photosensitive layer
Versions are included.

[0040]

[Positive PS plate] Of these, the main components of the photosensitive composition of the positive PS plate are a polymer binder and an o-quinonediazide compound.

[0041]

[Binder] As the binder, a polymer compound soluble in an alkaline developing solution is suitable, and particularly preferable polymer compounds soluble in alkaline water include, for example, phenol formaldehyde resin, o-, m- and p-cresol. Formaldehyde resin, m / p-mixed cresol Formaldehyde resin, phenol / cresol (o-,
m-, p-, m / p- and o / m-mixtures). Further, pyrogallol-acetone resin, hydroxystyrene resin and halogenated hydroxystyrene resin are also preferable.

The amount of the polymer binder in the photosensitive layer of the PS plate used in the present invention is 30 to 90% by weight, more preferably 40 to 70% by weight. In the photosensitive composition of the PS plate used in the present invention, other alkali-soluble resin can be optionally used in combination. Examples of the alkali-soluble resin include the following (1) to (4)
A film-forming resin having at least one selected from the alkali-soluble group-containing monomers as described above as a polymerization component is preferable. Furthermore, in addition to these alkali-soluble group-containing monomers, a film-forming resin obtained by copolymerizing the following monomers (5) to (14) is preferably used. (1) For example, N- (4-hydroxyphenyl) acrylamide or N- (4-hydroxyphenyl) methacrylamide, o-, m- or p-hydroxystyrene,
o- or m-bromo-p-hydroxystyrene, o-
Or m-chloro-p-hydroxystyrene, o-, m
-Or p-hydroxyphenyl acrylate or methacrylate such as acrylamides having an aromatic hydroxyl group, methacrylamides, acrylic acid esters, methacrylic acid esters and hydroxystyrenes,
(2) Unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride and its half ester, itaconic acid, itaconic anhydride and its half ester, (3) N- (o-aminosulfonylphenyl)
Acrylamide, N- (m-aminosulfonylphenyl) acrylamide, N- (p-aminosulfonylphenyl) acrylamide, N- [1- (3-aminosulfonyl) naphthyl] acrylamide, N- (2-aminosulfonylethyl) acrylamide, etc. Acrylamides, N- (o-aminosulfonylphenyl) methacrylamide, N- (m-aminosulfonylphenyl) methacrylamide, N- (p-aminosulfonylphenyl) methacrylamide, N- [1- (3-aminosulfonyl) )
Naphthyl] methacrylamide, methacrylamides such as N- (2-aminosulfonylethyl) methacrylamide, o-aminosulfonylphenyl acrylate, m-aminosulfonylphenyl acrylate, p-
Unsaturated sulfonamides such as acrylic acid esters such as aminosulfonylphenyl acrylate and 1- (3-aminosulfonylphenylnaphthyl) acrylate, o
-Unsaturated sulfonamides such as methacrylic acid esters such as -aminosulfonylphenyl methacrylate, m-aminosulfonylphenyl methacrylate, p-aminosulfonylphenyl methacrylate, 1- (3-aminosulfonylphenylnaphthyl) methacrylate, (4)
Phenylsulfonyl acrylamide optionally substituted such as tosyl acrylamide, and phenyl sulfonyl methacrylamide optionally substituted such as tosyl methacrylamide. (5) Acrylic acid esters and methacrylic acid esters having an aliphatic hydroxyl group,
For example, 2-hydroxyethyl acrylate or 2-
Hydroxyethyl methacrylate, (6) methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate,
Cyclohexyl acrylate, octyl acrylate, phenyl acrylate, benzyl acrylate, acrylate-2
-Chloroethyl, 4-hydroxybutyl acrylate,
(Substituted) acrylic acid esters such as glycidyl acrylate and N-dimethylaminoethyl acrylate, (7)
Methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, octyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-chloroethyl methacrylate, methacrylic acid 4 (Substituted) methacrylic acid esters such as -hydroxybutyl, glycidyl methacrylate and N-dimethylaminoethyl methacrylate, (8) acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, N-ethylacrylamide, N-ethylmethacryl Amide, N-hexyl acrylamide, N-hexyl methacrylamide, N-cyclohexyl acrylamide, N-cyclohexyl methacrylamide N- hydroxyethyl acrylamide, N- hydroxyethyl methacrylamide, N
-Phenylacrylamide, N-phenylmethacrylamide, N-benzylacrylamide, N-benzylmethacrylamide, N-nitrophenylacrylamide, N
-Nitrophenylmethacrylamide, N-ethyl-N-
Acrylamides or methacrylamides such as phenylacrylamide and N-ethyl-N-phenylmethacrylamide, (9) ethyl vinyl ether, 2-
Vinyl ethers such as chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octyl vinyl ether and phenyl vinyl ether, (10) Vinyl acetate, vinyl chloroacetate, vinyl butyrate, vinyl benzoate and other vinyl esters, (11) Styrenes such as styrene, α-methylstyrene, methylstyrene and chloromethylstyrene, vinyl ketones such as (12) methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone and phenyl vinyl ketone, (13) ethylene, propylene and isobutylene, Olefin such as butadiene and isoprene, (14) N-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine,
Acrylonitrile, methacrylonitrile, etc.

Such alkali-soluble film-forming resins can be used alone or in combination of two or more, and are used in an amount of 50% by weight or less based on the total photosensitive composition. The preferred molecular weight of the above copolymer is 10,000 to 10
It is ten thousand. If necessary, a polyvinyl butyral resin, a polyurethane resin, a polyamide resin, and an epoxy resin may be added to the copolymer.

These alkali-soluble polymer compounds can be used alone or in combination of two or more,
It is used in an amount of 40% by weight or less of the total photosensitive composition.

[0045]

[O-quinonediazide compound] PS used in the present invention
The o-naphthoquinonediazide compound, which is one of the main components of the photosensitive layer of the plate, is preferably an o-quinonediazide sulfonic acid ester of a polyhydroxy compound. As such a polyhydroxy compound, pyrogallol-acetone resin,
Examples thereof include phenol-formaldehyde resin, cresol formaldehyde resin, hydroxystyrene resin and halogenated hydroxystyrene resin. When synthesizing an o-naphthoquinonediazide compound from these polyhydroxy compounds, it is preferable to react 1,2-diazonaphthoquinonesulfonic acid chloride with 0.2 to 1.2 equivalents relative to the hydroxyl group of the polyhydroxy compound, It is more preferable to react 0.3 to 1.0 equivalent. As the 1,2-diazonaphthoquinonesulfonic acid chloride, 1,2-diazonaphthoquinone-5-sulfonic acid chloride or 1,2-diazonaphthoquinone-4-sulfonic acid chloride can be used.

The obtained o-naphthoquinonediazide compound is a mixture of 1,2-diazonaphthoquinonesulfonic acid ester groups having different positions and introduction amounts, but all of the hydroxyl groups are 1,2-diazonaphthoquinonesulfone. The proportion of the acid-esterified compound in this mixture (content of the completely esterified compound) is preferably 5 mol% or more, more preferably 20 to 99 mol%. Specific examples of o-quinonediazide compounds are described in JP-A Nos. 51-139402 and 58-58.
-150948, 58-203434, 59-
165053, 60-121445, 60-1
34235, 60-163043, 61-11
No. 8744, No. 62-10645, No. 62-1064
No. 6, No. 62-153950, No. 62-178562.
No. 64-76047, U.S. Pat. No. 3,102,8.
No. 09, No. 3,126, 281 and No. 3,130,
No. 047, No. 3,148,983, No. 3,18
No. 4,310, No. 3,188,210, No. 4,6
Examples thereof include those described in each publication or specification such as No. 39,406.

The amount of the o-quinonediazide compound in the total amount of the photosensitive composition of the PS plate used in the present invention is 10 to 10.
50% by weight is suitable, and more preferably 15-40% by weight.

[0048]

[Oil-sensitizing agent] Further, as described in US Pat. No. 4,123,279, a substituent having an alkyl group having 3 to 8 carbon atoms such as t-butylphenolformaldehyde resin and octylphenolformaldehyde resin is substituted. It is preferable to use the condensate of phenol and formaldehyde, which is also used, in order to improve the oil sensitivity of the image.

[0049]

[Development Accelerator] In the photosensitive composition of the PS plate used in the present invention, it is preferable to add cyclic acid anhydrides, phenols and organic acids in order to enhance sensitivity. Examples of the cyclic acid anhydride include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 3,6-endooxy-Δ4-tetrahydrophthalic anhydride described in U.S. Pat. No. 4,115,128. Tetrachlorphthalic anhydride, maleic anhydride, chloromaleic anhydride, α
-Phenyl maleic anhydride, succinic anhydride, pyromellitic dianhydride, etc. can be used.

Examples of phenols include bisphenol A, p-nitrophenol, p-ethoxyphenol,
2,4,4'-trihydroxybenzophenone, 2,
3,4-trihydroxybenzophenone, 4-hydroxybenzophenone, 4,4 ', 4 "-trihydroxy-
Examples thereof include triphenylmethane, 4,4 ′, 3 ″, 4 ″ -tetrahydroxy-3,5,3 ′, 5′-tetramethyltriphenylmethane.

Further, as organic acids, JP-A-60-8 is used.
No. 8942, JP-A-2-96755 and the like, there are sulfonic acids, sulfinic acids, alkyl sulfates, phosphonic acids, phosphoric esters and carboxylic acids, and specifically, p-toluene sulfone Acid, dodecylbenzenesulfonic acid, p-toluenesulfinic acid, ethyl sulfate, phenylphosphonic acid, phenylphosphinic acid, phenyl phosphate, diphenyl phosphate, benzoic acid, isophthalic acid, adipic acid, p-toluic acid,
3,4-dimethoxybenzoic acid, phthalic acid, terephthalic acid, 1,4-cyclohexene-2,2-dicarboxylic acid,
Erucic acid, lauric acid, n-undecanoic acid, ascorbic acid and the like can be mentioned.

The ratio of the above cyclic acid anhydrides, phenols and organic acids in the photosensitive composition is 0.05.
-15% by weight is preferable, and 0.1-5% by weight is more preferable.

[0053]

[Development Stabilizer] Further, in the PS plate photosensitive composition used in the present invention, in order to broaden the stability of processing to developing conditions (so-called development latitude), JP-A-62-25 is used.
Nonionic surfactants such as those described in JP 1740 and JP 4-68355 A, JP 59-12.
Amphoteric surfactants such as those described in Japanese Patent Application No. 1044 and Japanese Patent Application No. 2-115992 can be added.

Specific examples of the nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan trioleate, stearic acid monoglyceride, polyoxyethylene sorbitan monooleate and polyoxyethylene nonylphenyl ether. Specific examples of the amphoteric surfactant include alkyl di (aminoethyl) glycine, alkyl polyaminoethyl glycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine and N
-Tetradecyl-N, N-betaine type (for example, trade name Amogen K, manufactured by Dai-ichi Kogyo Co., Ltd.) and alkyl imidazoline type (for example, trade name Levon 15, Sanyo Kasei Co., Ltd.)
Manufactured).

The proportion of the above nonionic surfactant and amphoteric surfactant in the photosensitive composition is 0.05 to 15.
% Is preferable, and 0.1 to 5% is more preferable.

[0056]

[Print-out agent and dye] In the PS plate photosensitive composition used in the present invention, a print-out agent for obtaining a visible image immediately after exposure and a dye or pigment as an image colorant can be added. . Representative examples of the printing-out agent include a combination of a compound that releases an acid upon exposure (photoacid releasing agent) and an organic dye that can form a salt. Specifically, combinations of o-naphthoquinonediazide-4-sulfonic acid halogenide and salt-forming organic dyes described in JP-A Nos. 50-36209 and 53-8128, and JP-A-53-53, -36223, 54-74728, 60
-3626, 61-143748, 61-15
Examples thereof include combinations of trihalomethyl compounds and salt-forming organic dyes described in JP-A Nos. 1644 and 63-58440. Such trihalomethyl compounds include oxazole-based compounds and triazine-based compounds, both of which have excellent stability over time and give clear print-out images.

As the image colorant, other dyes can be used in addition to the above-mentioned salt-forming organic dyes. Suitable dyes, including salt-forming organic dyes, include oil-soluble dyes and basic dyes. Specifically, Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS,
Oil Blue # 603, Oil Black BY, Oil Black BS, Oil Black T-505 (all manufactured by Orient Chemical Industry Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), malachite green (CI42000), methylene blue (CI5201)
5) and the like. Further, Japanese Patent Application Laid-Open No.
The dyes described in Japanese Patent No. 93247 are particularly preferable.

[0058]

[Coating Solvent] The PS plate photosensitive layer used in the present invention is dissolved in a solvent capable of dissolving each of the above components and coated on an aluminum plate of a support. As the solvent used here, the organic solvents described in Japanese Patent Application No. 61-95463 can be used alone or in combination.

The photosensitive composition of the present invention contains 2 to 50% by weight.
Is dissolved and dispersed at a solid content concentration of, and coated and dried on a support.

[0060]

[Coating amount] The coating amount of the layer of the photosensitive composition (photosensitive layer) coated on the support varies depending on the use, but is generally 0.3 to 4.0 g / dry weight. m ² is preferred.
As the amount of coating decreases, the amount of exposure for obtaining an image may be small, but the film strength is reduced. As the coating amount increases, the exposure amount is required but the photosensitive film becomes strong. For example, when used as a printing plate, a printing plate having a high printable number (high printing durability) can be obtained.

[0061]

[Improvement of coating surface quality] In the photosensitive layer of the PS plate used in the present invention, a surfactant for improving coating surface quality, for example,
Fluorine-based surfactants as described in JP-A-62-170950 can be added. The preferable addition amount is 0.001 to 1.0% by weight of the total photosensitive composition, and more preferably 0.005 to 0.5% by weight.

[0062]

[Matt layer] A mat layer is provided on the surface of the photosensitive layer provided as described above in order to reduce the vacuuming time during contact exposure using a vacuum baking frame and to prevent baking blur. Is preferred. Specifically, JP-A-50-1258
No. 05, Japanese Patent Publication No. 57-6582, No. 61-28986
And a method in which a solid powder is thermally fused as described in JP-B-62-62337.

[0063]

[Support] The PS plate photosensitive layer used in the present invention is coated on a support to be used as a PS plate. As such a support, the support described in JP-A-5-45885 is used.

[0064]

[Organic Undercoat Layer] The support may be provided with an organic undercoat layer as described in JP-A-5-45885, if necessary, before coating the photosensitive layer.

[0065]

[Backcoat] A backcoat is provided on the back surface of the support, if necessary. Such a back coat comprises a metal oxide obtained by hydrolyzing and polycondensing an organic polymer compound described in JP-A-5-45885 and an organic or inorganic metal compound described in Japanese Patent Application No. 4-189448. A coating layer is preferably used.

Of these coating layers, Si (OC
H_Three)_Four, Si (OC_TwoH_Five)_Four, Si (OC _ThreeH₇)_Four, S
i (OC_FourH₉)_FourCheap silicon alkoxy compounds such as
It is easy to obtain the metal oxide coating layer obtained from
It has excellent resistance to developing solution and is particularly preferable.

[0067]

[Negative PS Plate] Examples of the negative PS plate to which the treatment method of the present invention is preferably applied include those having a photosensitive layer containing a photosensitive diazo compound, a photopolymerizable photosensitive layer, a photocrosslinkable photosensitive layer and the like. However, as a particularly preferred example, JP-A-6-
The PS plate having a negative photosensitive layer described in detail in Japanese Patent No. 282079 can be mentioned.

[0068]

[Development and Post-Treatment] The PS plate used in the present invention is exposed through a transparent original image by an actinic ray having a carbon arc lamp, a mercury lamp, a metal halide lamp, a xenon lamp, a tungsten lamp or the like as a light source, and then, by the processing method of the present invention. It is developed. The processing method of the present invention is carried out using an automatic processor. In recent years, in the plate making and printing industries, automatic developing machines for PS plates have been widely used in order to streamline and standardize plate making operations. This automatic developing machine generally comprises a developing section and a post-processing section, an apparatus for conveying a PS plate, each processing solution tank and a spraying apparatus, and the exposed PS
While the plate is conveyed horizontally, each processing liquid pumped up by a pump is sprayed from a spray nozzle to develop and post-process. Further, recently, a method has been used in which a PS plate is immersed and conveyed by a submerged guide roll or the like in a processing solution tank filled with the processing solution, and a developing process is carried out. This method is most preferred for the processing method of the present invention. Applicable.

The developed PS plate is post-treated with washing water, a rinse solution containing a surfactant and the like, a finisher and a protective gum solution mainly containing gum arabic and a starch derivative. These treatments can be used in various combinations for the post-treatment of the PS plate of the present invention. For example,
Development → Rinse processing, Development → Finisher processing, Development →
Rinse → Rinse treatment, Development → Rinse → Finisher treatment,
Processing such as development → washing → rinsing treatment → protective gum, development → rinsing treatment → finisher treatment can be combined. Further, countercurrent multi-stage processing using a plurality of processing tanks, such as development-> rinse processing-> rinse processing, development-> finisher processing-> finisher processing, is also preferable.

Further, in the treatment method of the present invention, it is preferable to replenish each replenisher according to the treatment amount also in the above post-treatment. One embodiment of the treatment method of the present invention will be described in detail below, but in addition to this, Japanese Patent Application No. 7-253472.
The developing replenishment method described in the specification can be preferably applied to the present invention. The lithographic printing plate obtained by such a process is set on an offset printing machine and used for printing a large number of sheets.

Next, an automatic developing machine to which an embodiment of the PS plate processing method according to the present invention is applied will be described with reference to FIG. In FIG. 1, the sheet-shaped PS plate 10 is continuously conveyed while being horizontally or curved in a predetermined conveying direction (arrow A direction) with the photosensitive layer on the upper surface.
0, the washing section 50 and the finisher section 60 are respectively subjected to predetermined processing. The activity of the developer stored in the developing tank 21 of the developing unit 20 is determined by the supply of the developing replenisher to the developing tank 21 under the control of a control unit (not shown).
It is kept almost constant.

In the developing section 20, the photosensitive layer of the PS plate 10 is developed by the action of the developer stored in the developing tank 21. The developing unit 20 includes a transport roller 22,
A pair of upper and lower squeeze rollers 23 and 24 are provided so as to sandwich the PS plate 10, and a rotating brush roller 25 is provided so as to sandwich the PS plate 10 with the guide rollers 26 or 28.

By rotating the PS plate 10 while sandwiching the PS plate 10, the transfer roller 22 guides the PS plate 10 by the guide roller 27 and the guide plate 30 and conveys the PS plate 10 while curving the PS plate 10 in the developing solution in the developing tank 21. Soak in. The squeeze roller 23 is disposed substantially in the center of the developing tank 21, is immersed in the developing solution, and rotates while holding the PS plate 10 passing through the developing solution, thereby conveying the PS plate 10 and Wastes and the like in the developer adhering to the surface of the photosensitive layer of the PS plate 10 are removed.

The squeeze roller 24 is disposed on the downstream side in the transport direction A in the developing tank 21, and rotates the PS plate 10 that has passed through the developing solution while being sandwiched, thereby transporting the PS plate 10. Excess developer adhering to the surface of the PS plate 10 is removed. Each of the brush rollers 25 is arranged so as to be immersed in the developing solution, and is rotated by a brush roller motor (not shown) to scrape off the elution layer on the surface of the PS plate 10.

A spray pipe 31 is provided in the developing tank 21 near the lower end of the guide plate 30 and at a position sandwiched by the squeeze roller 23 and the guide roller 26. Each spray pipe 31 has a large number of discharge ports (not shown), and each discharge port communicates with the developing tank 21 via a circulation pipe 32 and a circulation pump 33. Each spray pipe 31 develops by ejecting the developer sucked from the developing tank 21 toward the bottom of the developing tank 21 again from each discharge port in accordance with the operation of the circulation pump 33 based on the control of the controller. The developer in the bath 21 is circulated.

A sensor 34 is provided on the circulation pipe 32 that connects each spray pipe 31 and the circulation pump 33. The sensor 34 detects the deterioration of the developing solution caused by the processing of the image-exposed PS plate 10 by measuring the electric conductivity or the impedance of the developing solution. Developing tank 21
Is connected to a developing replenisher stock solution tank 35 through a connecting pipe 36 and a stock solution replenishing pump 37, and the developing replenisher stock solution tank 35 develops from the developing replenisher solution stock solution tank 35 in accordance with the operation of the stock solution replenishing pump 37 under the control of the controller. A required amount of developing replenisher stock solution is supplied to the tank 21.

A liquid surface lid 38 is arranged in the developing tank 21 so as to come into contact with the stored developing solution and cover the surface thereof. The liquid surface lid 38 is made of a lightweight material such as polyvinyl chloride, polyethylene or polyamide. Liquid cover 38
Is supported by a machine frame (not shown) so that both ends thereof in the transport direction A can move up and down, and by moving up and down according to the change in the liquid level of the developer, the contact between the developer surface and the air is suppressed as much as possible. .

In the vicinity of both ends of the liquid level lid 38 in the transport direction A,
The blade 39 has a liquid level lid 38 and an outer panel 11 respectively.
It will be installed between and. Each blade 39 substantially completely isolates the space surrounded by the upper surface of the liquid surface lid 38 in FIG. 1 and the inner surface of the outer panel 11 from the outside air, thereby suppressing the evaporation of the developing solution as much as possible. In the water washing section 50, PS
The plate 10 is subjected to the required washing treatment. In the washing section 50,
Two pairs of conveying rollers 51 are provided so as to sandwich the PS plate 10, and a spray pipe 52 is provided between the conveying rollers 51.

The spray pipe 52 has a large number of discharge ports (not shown), and each discharge port communicates with a washing water tank 55 via a connecting pipe 53 and a washing pump 54. The spray pipe 52 sprays a large amount of water from the discharge port on the upper surface of the transport roller 51 on the downstream side in accordance with the operation of the washing pump 54, so that the P after the development processing is performed.
The surface of the S plate 10 is washed with water via the conveyance roller 51. Each of the transport rollers 51 is arranged so as to be immersed in the water stored in the receiving tray 56 in the lower side of FIG. 1, and the PS plate 10 is substantially rotated by rotating the PS plate 10 in a sandwiched state. It is transported horizontally and the saucer 5
The bottom surface of the PS plate 10 in FIG. 1 is washed with water drawn from 6. The tray 56 is the lower conveyance roller 5 in FIG.
1 is provided so as to cover the lower half of the first plate 1 and stores the water from the spray pipe 52 whose upper surface in FIG.

A washing tank 57 is provided below the tray 56 to store the water overflowing from the tray 56. The washing tank 57 communicates with the developing tank 21 via a connecting pipe 58 and a water replenishing pump 59. That is, the required amount of water in the washing tank 57 is supplied to the developing tank 21 in accordance with the operation of the water replenishing pump 59 under the control of the control unit, and becomes the diluted water of the developing replenisher stock solution.

In the finisher section 60, the PS plate 10 is subjected to the required finishing treatment by the action of the gum solution. The finisher section 60 has a spray pipe 61.
Are provided above and below with the PS plate 10 interposed therebetween, and the squeeze roller 6 is provided on the downstream side of the spray pipe 61.
Two PS's are provided on the upper and lower sides with the PS plate 10 interposed therebetween. Each of the spray pipes 61 has a large number of discharge ports (not shown), and each discharge port communicates with a gum solution tank 65 via a connecting pipe 63 and a gum solution pump 64. Each of the spray pipes 61 has a gum solution pump 64.
1, the gum liquid (finishing liquid) is sprayed toward each of the guide plates 66 facing the discharge port, so that the upper surface and the lower surface of the PS plate 10 after the water washing process in FIG.
The gum solution is sprayed through each guide plate 66.

Each of the squeeze rollers 62 is a PS plate 1
By rotating with 0 clamped, the PS plate 10
And the excess gum solution adhering to the surface of the PS plate 10 after the finishing treatment is removed. Squeeze roller 62
The gum solution removed by is collected in the gum solution tank 67. The lower half of the lower squeeze roller 62 in FIG. 1 is immersed in the gum solution in the gum solution tank 67.
The gum solution pumped up from 7 is applied to the lower surface of the PS plate 10 in FIG.

In the developing section 20, the water washing section 50, and the finisher section 60, the developing tank 21, the water washing tank 57, and the gum solution tank 67 are provided with overflow pipes 12, respectively. Each overflow pipe 12 communicates with a waste liquid tank 14 via a connecting pipe 13, and when the liquid level of each tank exceeds a predetermined height, the liquid overflowing from each tank is drained via the connecting pipe 13 to the waste liquid tank 14. Discharge to the tank 14.

The control section calculates the amount m of the developer replenisher and the dilution ratio based on the detection result of the conductivity or the impedance of the developer by the sensor 34. Then, the control unit controls the stock solution replenishing pump 37 and the water replenishing pump 59 to supply the required amount of the development replenishing solution diluted to the calculated ratio to the developing tank 21, that is, from the development replenishing solution stock solution tank 35. A required amount of developing replenisher stock solution is supplied to the developing tank 21, and a required amount of water is supplied from the washing tank 57 to the developing tank 21.
To supply. As a result, the control unit always keeps the activity of the developer stored in the developing tank 21 substantially constant.

FIG. 2 is a control flowchart for replenishing the developing replenisher into the developing tank 21 by the control unit. Hereinafter, the replenishment control of the development replenisher will be described with reference to FIG. 2 (see FIG. 1 for reference numerals). When the operation of the automatic developing machine is started, the brush roller motor is activated in step S1 and the brush roller 25 is rotated. As a result, the developer in the developing tank 21 is agitated. Then, in step S2, the circulation pump 33 is operated, and the circulation of the developer in the developing tank 21 is started. In this way, since the developer is stirred and circulated immediately after the start of the operation, it is possible to eliminate the concentration unevenness of the developer that occurs during the stop of the operation of the automatic developing machine, relatively early.

Next, in step S3, it is determined whether or not it is time to measure the electrical conductivity (or impedance). If it is time to measure, the process proceeds to step S4. On the other hand, when it is not the measurement time, the determination in step S3 is repeated. In step S4, the electrical conductivity (or impedance) of the developer is measured by the sensor 34, and in step S5, the electrical conductivity (or impedance) is within a predetermined allowable range based on the measured value of the electrical conductivity (or impedance). It is determined whether or not there is a need for replenishment of the developing replenisher.

When it is judged in step S5 that the replenishment of the developing replenisher is necessary, the process proceeds to step S6, and the data is stored in the memory of the control unit based on the measured value of the electric conductivity (or impedance). The replenishment amount n of the developing replenisher required per liter of the developer is read from the existing map, and the developer volume D stored in the developing tank 21 is read in step S7. On the other hand, if it is determined in step S5 that replenishment is not necessary, the process proceeds to step S13.

In step S8, the amount of developing replenisher solution m corresponding to the developing solution volume D is calculated (m = n × D), and in step S9, development is performed based on the calculated developing replenisher solution amount m and the dilution ratio. The stock solution replenishing solution amount and the diluting water amount are set respectively, and further, in step S10, the stock solution replenishing pump 37 and the water replenishing pump 59 are operated, and the required amount of the development replenishing solution diluted to the calculated ratio is obtained.
Supplied within.

In step S11, it is determined whether or not the developing tank 21 has been replenished with a predetermined amount of developing replenisher solution m. If it is determined that the replenishment has been completed, step S
12, the stock solution replenishing pump 37 and the water replenishing pump 59 are stopped in step S12. On the other hand, if it is determined that the supplement has not been completed, the determination in step S11 is repeated.

In step S13, it is determined whether or not a predetermined time has elapsed since the electrical conductivity (or impedance) was measured. When it is determined that the predetermined time has elapsed after the measurement of the electric conductivity (or impedance), the process proceeds to step S14, and in step S14, the brush roller motor is stopped and the rotation of the brush roller 25 is stopped. Further, in step S15, the circulation pump 33 is stopped and then reset.

On the other hand, if it is determined in step S13 that the predetermined time has not elapsed after the measurement of the electric conductivity (or impedance), the determination of step S13 is repeated. In addition, in the above-described replenishment control, when the electric conductivity (or impedance) is measured for the second time and thereafter, the brush roller 25 is driven by the brush roller motor PS
Circulation pump 33 so that it is performed only while the plate is passing
Are controlled so as to be activated at every conductivity (or impedance) measurement time.

The present invention is described in detail below with reference to examples. Example 1 An aluminum plate having a thickness of 0.24 mm was grained on its surface using a nylon brush and a 400 mesh pumicetone-water suspension, and then thoroughly washed with water. Immerse in 10% sodium hydroxide at 70 ° C. for 20 seconds for etching, then rinse with running water, and then neutralize with 20% HNO ₃ .
Washed with water. This was subjected to electrolytic surface-roughening treatment in a 0.7% nitric acid aqueous solution with an electric quantity of 400 coulomb / dm ² using a sinusoidal alternating waveform current under the condition of VA = 12.7V. This substrate was treated in a 10% aqueous sodium hydroxide solution so that the amount of aluminum dissolved on the surface was 0.9 g / m ² . After washing with water, neutralization in a 20% nitric acid solution, washing to remove smut, and then anodic oxidation in an 18% H ₂ SO ₄ aqueous solution so that the amount of oxide film was 3 g / m ² .

Then, it was immersed in a 2% aqueous solution of No. J3 sodium silicate at 30 ° C. for 15 seconds for hydrophilic treatment. On the thus-prepared support, the undercoat solution a having the following composition was applied so as to have a dry weight of 10 mg / m ² and 90 ° C.
And dried for 1 minute to form an undercoat layer. Undercoat liquid a Phenylphosphonic acid 0.06 parts by weight Sulfuric acid 0.12 parts by weight Methanol 100 parts by weight Subsequently, a photosensitive solution having the following composition was prepared, and the weight after drying was 1.8 g / m ² on the substrate. The photosensitive layer was provided so that. Photosensitive solution m-cresol formaldehyde resin (content of trinuclear or higher components 86.5% by weight, molecular weight 4,800) 1.9 parts by weight 1,2-diazonaphthoquinone-5-sulfonyl chloride and pyrogallol-acetone resin Esterification product (molecular weight 2,500) 0.76 parts by weight tetrahydrophthalic anhydride 0.2 parts by weight 4- [p-N- (p-hydroxybenzoyl) aminophenyl] -2,6-bis (trichloromethyl)- s-Triazine 0.02 parts by weight Victoria Pure Blue BOH (Hodogaya Chemical Co., Ltd.) 0.03 parts by weight Megafac F-177 (Dainippon Ink and Chemicals Co., Ltd. fluorine surfactant) 006 parts by weight Methyl ethyl ketone 15 parts by weight Propylene glycol monomethyl ether 15 parts by weight It provided a matte layer by spraying a mat layer-forming resin solution in the like, to obtain a PS plate A.

A 12% aqueous solution of methyl methacrylate / ethyl acrylate / acrylic acid (preparation weight ratio 65:20:15) copolymer as a part of sodium salt was prepared as a mat layer forming resin solution, and was subjected to rotary atomization. Rotation speed of atomizing head is 25,000 rpm and the amount of resin liquid is 40 with an electric coating machine.
ml / min, the applied voltage to the atomizing head is -90 kV, the ambient temperature at the time of application is 25 ° C., and the relative humidity is 50%.
The coated surface was sprayed with steam for 5 seconds to wet it, and then, 3 seconds after wetting, hot air with a temperature of 60 ° C. and a humidity of 10% was sprayed for 5 seconds to dry. The height of the mat was about 6 μm, the size was about 30 μm, and the number was 150 / mm ² .

The PS plate A thus obtained was treated with 1,0
A large number of sheets cut into a size of 03 mm × 800 mm were prepared, and these were exposed through a document film for 60 seconds using a metal halide lamp of 3 kW from a distance of 1 m. Next, a commercially available automatic developing machine P having an immersion type developing tank
Into a S-900V (manufactured by Fuji Photo Film Co., Ltd.) developing tank, 18 liters of a developing solution having a pH of about 13.0, which was prepared by diluting the following developing solution stock solution 9 times with tap water, was charged and heated to 30 ° C. . Tap water is automatically supplied to the second washing bath of PS-900V so that the PS plate can be washed. FP in the finishing bath, which is the third bath
2 liters of -2W (manufactured by Fuji Photo Film Co., Ltd.) was diluted twice with tap water, and 4 liters of a finishing liquid was charged. Separately, the developing replenisher stock solution tank was charged with 5 liter of the following developing replenisher stock solution a.

The automatic processor PS-900V is PS
A decrease in the liquid activity of the plate processing and the development due to carbon dioxide in the air is detected by a built-in AC impedance meter, and a feedback control of a computer based on the detected value detects that water is added to the developing replenisher stock solution a1. The developer replenisher diluted in the ratio of is added to the developing tank. As a result, the activity of the developer stored in the developing tank is kept substantially constant. The automatic processor PS-900V has an impedance setting range of 12.5 to 25.0 in the commercial state.
Since it is Ω · cm, the automatic processor PS-900V was modified so that the impedance of the developer a could be measured. The set value of the control impedance is 27.8Ω.
cm. Other conditions were PS-900V standard conditions.

Even in the post-processing section, the PS plate A is 1 m
^{2 After} each treatment, wash water 30ml, finishing liquid F
P-2W (a solution diluted two-fold with tap water) was supplemented at a rate of 20 ml. Undiluted developer a D-Sorbit 21.2% by weight Sodium hydroxide 7.5% by weight Ethanol oxide 30 mol adduct of triethanolamine 0.16% by weight DEQUEST 2066 (Chelating agent manufactured by Monsanto, USA) 0.34% by weight % Water 70.8% by weight Development replenisher stock solution a D-Sorbit 26.5% by weight Sodium hydroxide 10.7% by weight Ethanol oxide 30 mol adduct of triethanolamine 0.24% by weight DEQUEST 2066 (Monsanto, USA) Chelating agent) 1.2 wt% water 61.36 wt% Under such conditions, the exposed PS plate described above is
120 plates per day were processed every day except Saturday, Sunday and public holidays for 6 months.

For the activity check, a step tablet (15 steps with an optical density difference of 0.15 per step and 15 steps) was used to change the amount of light stepwise to develop the one printed on the PS plate, The number of steps of the remaining image corresponding to the amount of light on the plate was read and compared with the number of steps at the start of processing. During the 6-month test period, the clear part (complete image removal part) of the step tablet was kept at 5.5 steps, and the solid part (complete image remaining part) was kept at 11.5 steps, maintaining stable processing. It was After the processing, the developing solution was drained from the developing tank, but no insoluble matter was deposited on the bottom of the developing tank. In addition, when the surface of the impedance meter sensor was checked, it was in a good state with no dirt attached. Comparative Example 1 PS plate A was processed and evaluated in the same manner as in Example 1 except that the following developer b and development replenisher b were used. However, the developing replenisher used was a liquid diluted with the developing replenisher stock solution 1 at a ratio of water 6.5, and the set value of the control impedance was 16.0 Ω · cm.

From about the third month, the number of steps of the step tablet gradually started to increase. Then, when the developing solution was taken out from the developing tank, accumulation of insoluble matter was observed at the bottom of the developing tank. Insoluble matter was attached to the surface of the impedance meter sensor. Stock solution of developer b [SiO ₂ ] / [K ₂ O] molar ratio 1.2, potassium silicate aqueous solution of SiO ₂ 12.2 wt% 99.8 wt% polyoxyethylene (additional mole number n = 12) sorbit ether 0 0.2 wt% developing replenisher stock solution b [SiO ₂ ] / [K ₂ O] molar ratio 1.0, SiO ₂ 19.9 wt% potassium silicate aqueous solution 99.6 wt% polyoxyethylene (addition mole number n = 12) Sorbit ether 0.4% by weight Example 2 An aluminum plate having a thickness of 0.2 mm and a nylon brush were used.
The surface was sand-grained with an aqueous suspension of 00 mesh pamistone, and then thoroughly washed with water. After dipping in 10% sodium hydroxide at 70 ° C. for 60 seconds for etching and washing with running water, this was washed with 1% nitric acid aqueous solution under a condition of VA = 12.7V using a sinusoidal alternating current.
The electrolytic surface-roughening treatment was performed with an electric quantity at the time of the anode of 0 coulomb / dm ² . Subsequently, it is immersed in a 30% sulfuric acid aqueous solution and
After desmutting at 5 ° C for 2 minutes, in a 20% sulfuric acid aqueous solution,
Anodization was performed so that the thickness was 1.5 g / m ² at a current density of 2 A / dm ² , and then hydrophilization treatment was performed at 70 ° C. with a 2% aqueous solution of sodium silicate No. 3.

Next, the following sensitizing solution was prepared, coated on the previously grained substrate so as to have a dry weight of 1.5 g / m ^2, and dried at 80 ° C. for 2 minutes. A negative PS plate B was obtained. Photosensitive solution Methyl methacrylate / N- [6- (methacryloyloxy) hexyl] -2,3-dimethylmaleimide / methacrylic acid = 10/60/30 (molar ratio) copolymer [Mw = 3.5 × 104 (GPC) , Tg = about 40 ° C. (DSC)] 5 parts by weight 3-ethoxycarbonyl-7-methyl-thioxanthone 0.25 parts by weight Dodecylbenzene sulfonate of formaldehyde co-condensate of 4-diazodiphenylamine and phenoxyacetic acid 0.20 parts by weight Parts Propylene glycol monomethyl ether 50 parts by weight Methyl ethyl ketone 50 parts by weight Megaffac F-177 (Dainippon Ink and Chemicals, Inc., fluorine-based nonionic surfactant) 0.03 parts by weight Victoria Pure Blue BOH (Hodogaya Chemical Co., Ltd.) 0.10 parts by weight Next, the positive PS plate of Example 1 In the same manner as in Example 1 except that A and the negative PS plate B were used in a ratio of 1: 1,
The PS plates A and B were developed.

During the 6-month test period, the step tablet of PS plate A was kept at 5.5 steps in the clear section and 11.5 steps in the solid section. In addition, PS plate B was kept in a clear section of 8.5 steps and a solid section of 2.5 steps, and stable processing was maintained. After treatment,
The developer was drained from the developing tank, but no insoluble matter was found on the bottom of the developing tank. In addition, when the surface of the impedance sensor was checked, it was in a good state with no dirt attached. Example 4 A positive PS plate C was prepared in the same manner as in Example 1 except that the undercoat liquid B having the following composition was used. Undercoating liquid Poly-p-vinylbenzoic acid 0.5% by weight Methanol 95% by weight Water 4.5% by weight Treated in the same manner as in Example 1 except that this PS plate C was used, and the results were evaluated. Similar to the above, stable treatment was possible. Example 5 The same procedure as in Example 1 was carried out until the anodizing treatment, and the undercoat liquid (C) having the following composition was applied on the support prepared without the sodium silicate treatment so that the weight after drying was 10 mg / m ^2. And dried at 90 ° C. for 1 minute to form an undercoat layer. Undercoating liquid Hatriethanolamine / hydrochloride 0.5% by weight Methanol 95% by weight Water 4.5% by weight Subsequently, the photosensitive liquid of Example 1 was prepared, and the weight after drying was 1.8 g on the above substrate. The photosensitive layer was provided so as to be / m ² . Example 1 was formed on the surface of the photosensitive layer thus prepared.
In the same manner as above, a positive PS plate D having a mat layer was prepared by spraying the mat layer forming resin liquid.

The same treatment as in Example 1 was carried out except that this PS plate D was used, and the results were evaluated. As a result, similar to Example 1, stable treatment was possible. Example 6 Using a developing solution stock solution c (diluting solution pH of about 13.0) and a developing replenishing solution stock solution c having the following compositions, a control impedance set value was set to
As a result of treating PS plate A of Example 1 in the same manner as in Example 1 except that it was set to 6.1 Ωm · cm, as in Example 1, extremely stable treatment was possible. Stock solution of developer c D-saccharose 46.17% by weight sodium hydroxide 8.28% by weight Ethylene oxide 30 mol adduct of triethanolamine 0.27% by weight DEQUEST 2066 (chelating agent manufactured by Monsanto, USA) 0.6% by weight % Water 44.68% by weight Development replenisher stock solution cD-sucrose 51.3% by weight Sodium hydroxide 10.0% by weight Ethanol oxide 30 mol adduct of triethanolamine 0.35% by weight DEQUEST 2066 (Monsanto, USA) Chelating agent) 1.25% by weight water 37.1% by weight Example 7 Using a developing solution undiluted solution d (diluting solution pH of about 13.1) and a developing replenisher undiluted solution d having the following composition, a control impedance set value was set to 2
The PS plate A of Example 1 and the PS plate C of Example 4 were treated in the same manner as in Example 4 except that the resistance was 2.2 Ω · cm. As a result, similar to Example 4, extremely stable treatment was obtained. did it. Stock solution of developing solution d D-sorbit 21.2% by weight potassium hydroxide 7.4% by weight ethylene oxide 30 mol adduct of triethanolamine 0.16% by weight DEQUEST 2066 (a chelating agent manufactured by Monsanto, USA) 0.34% by weight % Water 70.9% by weight Development replenisher stock solution d D-Sorbit 26.4% by weight Potassium hydroxide 13.0% by weight Ethanol oxide 30 mol adduct of triethanolamine 0.24% by weight DEQUEST 2066 (Monsanto, USA) Chelating agent) 1.2% by weight Water 59.16% by weight

[0103]

According to the present invention, the use of a developing solution and a developing replenishing solution, which have a strong buffering effect on the alkaline side and hardly produce an insoluble matter on the sensor for measuring the activity of the developing solution, and the conductivity of the developing solution. Deterioration of the developing solution is detected by measuring the degree or impedance, and the developing replenisher is replenished based on the detection result, so that the photosensitive lithographic printing plate can be processed extremely stably for a long period of time. be able to.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an automatic developing machine to which an embodiment of a method for processing a photosensitive lithographic printing plate of the present invention is applied.

FIG. 2 is a control flowchart of replenishment of a developing replenisher into a developing tank by a control unit.

FIG. 3 is a control flowchart for replenishing a developing replenisher to a developing tank by a control unit.

[Explanation of symbols]

 10 Photosensitive planographic printing plate (PS plate) 20 Development section 21 Development tank 33 Circulation pump 34 Sensor 35 Development replenisher stock solution tank 37 Stock solution replenishment pump 50 Rinsing section 57 Rinsing tank 59 Water replenishing pump 60 Finisher section

Claims (2)

[Claims] 1. An acid dissociation constant (pKa) of 10.0 to 13.
While developing the photosensitive lithographic printing plate with a developer having a pH in the range of 9.0 to 13.9 and containing at least one weak acid having 3 and at least one base,
Deterioration of the activity of the developer is detected by measuring the conductivity or impedance of the developer, and a developer replenisher is replenished so as to keep the activity constant based on the detection result. And a method of processing a photosensitive lithographic printing plate. 2. The photosensitive lithographic printing plate is developed with a developer containing at least one saccharide selected from non-reducing sugars and at least one base and having a pH in the range of 9.0 to 13.9. At the same time, the deterioration of the activity of the developer is detected by measuring the conductivity or the impedance of the developer, and the developer replenisher is replenished so as to keep the activity constant based on the detection result. A method for treating a photosensitive lithographic printing plate characterized by: