JP2000206705A - Method for developing photosensitive lithographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To develop a plate material which can be exposed by an IR laser for a long time without causing image defects or the like by using an automatic developing device in which a specified amt. of a substantially unused developer is coated on every plate material to develop a plate material. SOLUTION: In the automatic developing device 1, the excess soln. of the developer sprayed to a plate material 10 by a spraying device 26 in a first zone is scraped off as not used for development of the plate material 10 by a wire bar 22 disposed near the spray device 26. Then a specified amt. of the developer is uniformly coated all over the surface of the plate material 10 by the wire bar 22. The developer scraped off hardly undergoes fatigue deterioration and is again supplied to the plate material 10 through the spraying device 26. Therefore, in this automatic developing device, development can be performed with a developer which is always in a good state and the plate material 10 can be developed for a long time without causing image defects or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for developing a photosensitive lithographic printing plate material, and more particularly to a method for developing a lithographic printing plate material capable of directly making a plate using a digital signal from a computer or the like using an infrared laser. .

[0002]

2. Description of the Related Art In recent years, a system for directly making a plate from digital data of a computer or the like without using a lith film or the like has attracted attention. In recent years, the development of lasers has been remarkable. Particularly, solid-state lasers and semiconductor lasers that emit light in the near-infrared to infrared region are easily available in high-power and small-sized ones. These lasers are very useful as exposure light sources for the system.

As an image recording material recordable by infrared laser exposure, Japanese Patent Application Laid-Open No. 7-285275 discloses
A binder such as cresol resin, a substance that absorbs light to generate heat, and a substance such as quinonediazide that is thermally decomposable and substantially reduces the solubility of the binder when not decomposed. And a positive-type image recording material containing: In the positive image recording material, a substance that absorbs light and generates heat in the exposed portion generates heat, thereby expressing the solubility of the exposed portion.

Further, JP-A-7-20625 and Japanese Patent Application No. 10-22404 disclose a compound which decomposes by light or heat to generate an acid, a cross-linking agent which cross-links with an acid, and an alkali-soluble resin. And a negative image recording material containing at least one of the above and an infrared absorbing agent. This negative-type image recording material is a cross-linking agent that, in an exposed portion, a substance that absorbs light and generates heat, generates heat, and a compound that is decomposed by the heat to generate an acid generates an acid, and the acid cross-links the compound. Image recording by accelerating the crosslinking reaction between the resin and the alkali-soluble resin.

[0005] The above-described image recording material can be used as a plate material for lithographic printing (hereinafter referred to as "plate material").
In order to form a lithographic printing plate, after recording an image on a plate material by infrared laser exposure, a heating process is performed if necessary, and then a development process is performed.

In general, an automatic developing apparatus is used for developing a plate material. As an automatic developing device, a plate material on which an image is recorded is conveyed into a developing tank, the plate material is immersed in a developing solution stored in the developing tank, and a brush roller or the like disposed in the developing solution is used. A structure in which a photosensitive layer in a non-image portion of a plate material is removed by a rubbing means is widely used. Further, the plate on which the image is recorded is conveyed while being pinched by a plurality of pairs of rollers. During this conveyance, the developer is sprayed onto the exposed surface of the plate in a spray form, and the plate is rubbed by a rubbing means such as a brush roller. Those configured to remove the photosensitive layer in the non-image area are also widely used.

[0007]

When a lithographic printing plate is formed by using the above-mentioned positive type image recording material or negative type recording material recordable by infrared laser exposure, for example, the printing plate has an image such as a stain. Defects and image omission sometimes occurred. Therefore, various attempts have been made to change the developing conditions in the automatic developing apparatus, but these image defects and image omissions could not be suppressed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a photosensitive material capable of developing a plate material which can be exposed by an infrared laser without causing image defects or the like over a long period of time. Another object of the present invention is to provide a method for developing a lithographic printing plate material.

[0009]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a positive type image recording material recordable by infrared laser exposure is easy to release heat to the support because the support is aluminum, When a substance that absorbs light and generates heat in a portion generates heat, a portion of the heat is absorbed by the aluminum support, thereby lowering the thermal efficiency and sufficiently expressing the solubility of the exposed portion. I found that I could not do it. Further, the present inventors have found that a negative-type image recording material that can be recorded by infrared laser exposure is a substance that easily escapes heat to the support because the support is aluminum, and absorbs light in the exposed portion to generate heat. It has been found that when heat is generated, a part of the heat is also absorbed by the aluminum support, so that the cross-linking reaction of the exposed portion cannot be sufficiently promoted. Due to these phenomena, when, for example, a lithographic printing plate is to be formed using the positive-type image recording material or the negative-type recording material, heat generation unevenness occurs at the time of infrared laser exposure, and image defects or image omissions occur on the printing plate. Occurs.

As a result of further intensive studies, the present inventor has found that
By applying a predetermined amount of a good developing solution which has not been fatigued and deteriorated for each plate material by an automatic developing device and performing a developing process,
It has been found that the occurrence of image defects and the like can be significantly suppressed.
That is, the present invention provides a method for developing a photosensitive lithographic printing plate material that can be exposed by an infrared laser, wherein an automatic developing device that applies a predetermined amount of a substantially unused developing solution is used for each plate material. It is characterized in that development processing of the plate material is performed.

The "substantially unused developer" as used herein means a developer having a developing ability equivalent to that of an unused developer. In the present invention, it is most preferable to use a completely unused developing solution, but it is also possible to mix a used developing solution with an unused developing solution within a range that does not reduce its developing ability. . It is preferable that the automatic developing device is provided with a measuring means for removing an excessive amount of the developing solution and uniformly applying a predetermined amount of the developing solution over the entire surface of the plate material. Examples of the measuring means include a wire bar, a grooved roller, and a blade.

According to such a developing method, a high developing processing ability in an automatic developing apparatus can be always maintained, and even if some processing unevenness occurs during exposure, the adverse effect of the processing unevenness on the plate material is developed. This can be solved by processing. Therefore, it is possible to develop a plate material that can be exposed by an infrared laser without causing image defects or the like over a long period of time.

The photosensitive lithographic printing plate material which is the object of the present invention includes the positive image recording material described in JP-A-7-285275, JP-A-7-20625 or Japanese Patent Application No. And those comprising a negative-type image recording material described in JP-A-22404.

The developer used in the present invention contains the following components. Developer (Alkali agent) The developer and the development replenisher used in the development method of the present invention are aqueous alkaline solutions having a pH of 10.0 to 13.5, more preferably 12.0 to 13.3. As such a developing solution and a developing replenishing solution, conventionally known alkaline aqueous solutions can be used. For example, sodium silicate, potassium, tribasic sodium, potassium, ammonium, dibasic sodium, potassium, ammonium, sodium bicarbonate, potassium,
Inorganic alkali agents such as ammonium, sodium carbonate, potassium, ammonium, sodium bicarbonate, potassium, ammonium, sodium borate, potassium, ammonium, sodium hydroxide, ammonium, potassium and lithium No.
Also, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, Ethyleneimine, ethylenediamine,
Organic alkali agents such as pyridine are also used.

Preferred among these alkaline agents are aqueous silicate solutions such as sodium silicate and potassium silicate. The reason is that silicon oxide Si
The ratio of O ₂ to the alkali metal oxide M ₂ O (generally [Si
O ₂ ] / [M ₂ O] molar ratio) and the concentration
This is because H and the developing property can be adjusted. For example,
The molar ratio of SiO ₂ / Na ₂ O is 1.5 to 2.5 (that is, [SiO ₂ ] / [Na ₂ O] is 1.5 to 2.5), and the content of SiO ₂ is 1 to An alkali metal silicate consisting of an aqueous solution of 4% by weight of sodium silicate is suitably used in the present invention.

A more preferred alkaline agent is a buffer solution comprising a weak acid and a strong base. Weak acids used as such buffers include an acid dissociation constant (pKa) of 10.
Those having a pKa of 0 to 13.3 are particularly preferable.
Those having 1.0 to 13.1 are preferred. For example, in the case of sulfosalicylic acid, the third dissociation constant is 11.7,
It can be suitably used in the present invention. That is, in the case of a polybasic acid, if at least one acid dissociation constant is within the above range, it can be used in the present invention.

Such weak acids include Pergamo.
IONISATION CON issued by nPress
STANTS OF ORGANIC ACIDS I
It is selected from those described in NAQUEOUS SOLUTION and the like, for example, 2,2,3,3-tetrafluoropropanol-1 (pKa 12.74), trifluoroethanol (12.37) and trichloroethanol (12.24) Alcohols such as pyridine)
Aldehydes such as 2-aldehyde (12.68), pyridine-4-aldehyde (12.05), sorbitol (13.0), saccharose (12.7),
-Deoxyribose (12.61), 2-deoxyglucose (12.51), glucose (12.4)
6), galactose (12.35), arabinose (12.34), xylose (12.29), fructose (12.27), lipose (12.2)
2), saccharides such as mannose (12.08) and L-ascorbic acid (11.34); salicylic acid (13.
0), 3-hydroxy-2-naphthoic acid (12.8
4), catechol (12.6), gallic acid (12.
4), sulfosalicylic acid (11.7), 3,4-dihydroxysulfonic acid (12.2), 3,4-dihydroxybenzoic acid (11.94), 1,2,4-trihydroxybenzene (12.4) 11.82), compounds having a phenolic hydroxyl group, such as hydroquinone (11.56), pyrogallol (11.34) and resorcinol (11.27), 2-butanone oxime (12.4).
5), acetoxime (12.42), 1,2-cycloheptanedione dioxime (12.3), 2-hydroxybenzaldehyde oxime (12.10), dimethylglyoxime (11.9), ethane Oximes such as diamide dioxime (11.37) and acetophenone oxime (11.35); 2-quinolone (1
1.76), 2-pyridone (11.65), 4-quinolone (11.28), 4-pyridone (11.11)
2), amino acids such as 5-aminovaleric acid (10.77), 2-mercaptoquinoline (10.25), 3-aminopropionic acid (10.24) and fluorouracil (13.0); Guanosine (12.6), uridine (12.6), adenosine (12.56), inosine (12.5), guanine (12.3), citidine (12.2), cytosine (12.6) 12.2), nucleic acid-related substances such as topoxanthin (12.1) and xanthine (11.9), diethylaminomethylphosphonic acid (12.32), 1-amino-3,3,3 -Trifluorobenzoic acid (12.29), isopropylidene diphosphonic acid (12.10), 1,1-ethylidene diphosphonic acid (11.54), 1,1-ethylidene diphosphonic acid 1-hydroxide Carboxymethyl (same 11.52), benzimidazole (same 12.86), thiobenzamide (the 1
2.8), picoline thioamide (12.55), barbituric acid (12.5) and the like. As the strong base to be combined with these weak acids, sodium hydroxide, ammonium hydroxide, potassium hydroxide and lithium hydroxide are used.

These alkaline agents are used alone or in combination of two or more. Preferred among these alkaline buffers are sulfosalicylic acid, salicylic acid,
It is a combination of saccharose and sorbitol with sodium hydroxide and potassium hydroxide. Among them, a preferred combination is sorbitol and potassium hydroxide or sodium hydroxide. The above-mentioned various alkaline agents are used by adjusting the pH within a preferred range depending on the concentration and combination.

(Surfactant) The developer and replenisher used in the present invention may contain various surfactants, if necessary, for the purpose of accelerating developability, dispersing development scum, and enhancing ink-philicity of a printing plate image area. Agents and 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 esters, propylene glycol monofatty acid esters, sucrose fatty acid partial esters, polyoxyethylene sorbitan fatty acid partial esters, polyoxyethylene sorbitol fatty acid partial esters, polyethylene glycol fatty acid esters, polyglycerin fatty acid partial esters , Polyoxyethylenated castor oils, polyoxyethylene glycerin fatty acid partial esters, fatty acid diethanolamides,
Nonionic surfactants such as N, N-bis-2-hydroxyalkylamines, polyoxyethylene alkylamines, triethanolamine fatty acid esters, and trialkylamine oxides, fatty acid salts, abietic acid salts,
Hydroxyalkanesulfonates, alkanesulfonates, dialkylsulfosuccinates, linear alkylbenzenesulfonates, branched alkylbenzenesulfonates, alkylnaphthalenesulfonates, alkylphenoxypolyoxyethylenepropylsulfonates, polyoxy Ethylene alkyl sulfophenyl ether salts, N-methyl-N-oleyltaurine sodium salt, N-alkyl sulfosuccinic acid monoamide disodium salt, petroleum sulfonates, sulfated tallow oil, sulfate salts of fatty acid alkyl esters, alkyl sulfates Salts, polyoxyethylene alkyl ether sulfates, fatty acid monoglyceride sulfates, polyoxyethylene alkyl phenyl ether sulfates, Oxyethylene styryl phenyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkyl phenyl ether phosphates, partially saponified styrene / maleic anhydride copolymers, Partially saponified olefin / maleic anhydride copolymers, anionic surfactants such as naphthalene sulfonate formalin condensates, quaternary ammonium salts such as alkylamine salts, tetrabutylammonium bromide, polyoxyethylene alkylamine Salts, cationic surfactants such as polyethylene polyamine derivatives, amphoteric surfactants such as carboxybetaines, aminocarboxylic acids, sulfobetaines, aminosulfates, and imidazolic acid. . Among the surfactants listed above, those with polyoxyethylene,
It can be read as a polyoxyalkylene such as polyoxymethylene, polyoxypropylene, polyoxybutylene, and their surfactants are also included.

Further preferred surfactants are fluorine-based surfactants 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 and perfluoroalkylamine oxides such as perfluoroalkyltrimethylammonium salts, perfluoroalkylethylene oxide adducts, oligomers containing perfluoroalkyl and hydrophilic groups,
Non-ionic forms 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. The above surfactants can be used alone or in combination of two or more, and are added to the developer in an amount of 0.001 to 10% by weight, more preferably 0.01 to 5% by weight.

(Development Stabilizer) Various development stabilizers are used in the developer and 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.

Further, 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 are disclosed. There is a water-soluble amphoteric polyelectrolyte described in the gazette. Further, an organic boron compound to which an alkylene glycol has been added described in JP-A-59-84241, a polyoxyethylene / polyoxypropylene block polymerization type water-soluble surfactant described in JP-A-60-111246, 1960-12
No. 9750, polyoxyethylene / polyoxypropylene-substituted alkylenediamine compounds;
Polyethylene glycol having a weight average molecular weight of 300 or more described in Japanese Patent Application Laid-Open No. 1-215554;
No. 8, a fluorine-containing surfactant having a cationic group,
Japanese Patent Application Laid-Open No. 2-39157 discloses an acid or alcohol
Water-soluble ethylene oxide addition compounds obtained by adding at least moles of ethylene oxide, water-soluble polyalkylene compounds, and the like.

(Organic Solvent) An organic solvent is further added to the developing solution and the developing replenisher, if necessary. 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-phenoxyethanol, Benzyloxyethanol, o-methoxybenzyl alcohol, m-methoxybenzyl alcohol, p-methoxybenzyl alcohol, benzyl alcohol, cyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol and 4-methylcyclohexanol, N-phenylethanol Examples include amines and N-phenyldiethanolamine. The content of the organic solvent is 0.1 to 5% by weight based on the total weight of the used solution. The amount used is closely related to the amount of surfactant used, and as the amount of organic solvent increases,
Preferably, the amount of surfactant is increased. 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.

(Reducing Agent) A reducing agent is further added to the developer and replenisher used in the present invention. This prevents contamination of 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. More 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 the developer during use,
It is contained in the range of 0.05 to 5% by weight.

(Organic carboxylic acid) The developing solution and replenisher used in the present invention may further contain an organic carboxylic acid. Preferred organic carboxylic acids are those having 6 to 2 carbon atoms.
0 fatty acid carboxylic acid and aromatic carboxylic acid.
Specific examples of aliphatic carboxylic acids include caproic acid,
Examples include enanthylic acid, caprylic acid, lauric acid, myristic acid, palmitic acid and stearic acid, and particularly preferred are alkanoic acids having 8 to 12 carbon atoms. Further, 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.
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-
Although there are naphthoic acid and the like, hydroxynaphthoic acid is particularly effective. The above aliphatic and aromatic carboxylic acids are preferably used as sodium salts, potassium salts or ammonium salts in order to increase the water solubility. The content of the organic carboxylic acid in the developer used in the present invention is not particularly limited,
An effect lower than 0.1% by weight is not sufficient, and an effect higher than 10% by weight cannot be improved further,
Dissolution may be hindered when another additive is used in combination. Therefore, the preferable addition amount is 0.1 to the developing solution at the time of use.
10 to 10% by weight, more preferably 0.5 to 4% by weight
It is.

(Others) The developer and replenisher used in the present invention may further contain an antifoaming agent and a water softener, if necessary. Examples of water softeners include polyphosphoric acid and its sodium, potassium and ammonium salts, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraminehexaneacetic acid, hydroxyethylethylenediaminetriacetic acid, nitrilotriacetic acid, 1,2-diaminocyclohexanetetraacetic acid. Acetic acid and 1,3-diamino-2-
Aminopolycarboxylic acids such as propanoltetraacetic acid and their sodium, potassium and ammonium salts, aminotri (methylenephosphonic acid), ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid), triethylenetetraminehexa (methylene Phosphonic acid), hydroxyethylethylenediaminetri (methylenephosphonic acid) and 1-hydroxyethane-1,1-diphosphonic acid and their sodium, potassium and ammonium salts. The optimum value of such a water softener varies depending on the chelating power, the hardness of the hard water used and the amount of the hard water. %, More preferably in the range of 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 replenisher is water, but may optionally contain various additives known in the art. It is advantageous from the viewpoint of transportation that the developing solution and the replenishing solution used in the present invention are prepared as concentrated solutions having a smaller water content than 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. In the present invention, the use of the developing solution as described above can further remarkably suppress the occurrence of image defects and the like.

[0029]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an automatic developing apparatus capable of implementing the present invention. The automatic developing device 1 is a plate material 1 on which an image is recorded by an infrared laser exposure device (not shown).
0 development processing. The plate material 10 nipped and conveyed by a pair of guide rollers 12 arranged on the upstream side of the automatic developing device 1 is automatically developed through a first area 14, a second area 16 and a third area 18.

In the first area 14, a pair of guide rollers 2
No. 0 pinches and transports the plate material 10. Immediately after the guide roller 20, a spray device 26 is disposed, and the spray device 26 is provided with a developer 30 in a stock tank 28.
Is supplied via a pump 34 and a pipe 32,
The developer is sprayed on the exposed surface of the plate material 10 by the spray device 26. After that, the printing plate 10 is sprayed by the spray device 26.
The developer transported between the wire bar 22 and the guide roller 24 in contact with the wire bar, which is disposed in the vicinity of the plate bar, is measured.

The wire bar 22 has a structure in which a wire 50 having a predetermined diameter is spirally wound around a shaft 48. The gap formed between the outer periphery of the wire 50 and the guide roller 24 causes the printing material 10 Metering of the developer on the surface takes place. That is, excess developer is scraped off, and a predetermined amount (for example, a liquid film thickness of 300 mm) is applied to the surface of the plate material 10 that has passed between the wire bar 22 and the guide roller 24.
μm). In addition, wire bar 2
Numeral 2 may be in a rotated state or a stopped state, so that the weighing operation can be appropriately performed. The scraped developer falls and is collected in a tray 36 disposed below the wire bar 22.

The developer recovered in the tray 36 is guided to the pipe 32 via the pipe 38 and the pump 40, and is again supplied to the spray device 26. The pipe 38 is connected to a pipe 44 via a valve 42 so that the developer in the tray 36 can be returned to the stock tank 28 at the end of the work. Further, a heater 46 is provided in the stock tank 28 so that the developer 30 can be maintained at a predetermined temperature.

The spray device 2 in the first section 14
6 and the wire bar 22 are arranged at predetermined intervals so that the developing solution sprayed on the plate material 10 by the spray device 26 does not start developing the exposed surface before reaching the wire bar 22. I have. The first area 14
The developing solution applied to the exposed surface of the plate material 10 is configured to spread over the entire width of the plate material in the width direction.

The stock tank 28 is connected to a replenishing water tank 100 via a pump 98 and a pipe 102, and is connected to a replenishing developer tank 114 via a pump 110 and a pipe 114. Liquid reductions are replenished from these tanks. Note that a configuration may be adopted in which the end of the printing plate 10 is detected by a sensor, and the supply of the developer from the spray device 26 is stopped.

In the second section 16, the plate 12 conveyed from the first section 14 is guided onto the guide plate 54 via the guide roller 52, and then onto the guide plate 58 via the guide roller 56. The plate material is guided, and the plate material is further conveyed between the pair of squeeze rollers 60. The guide plates 54 and 58 may be provided with a heater for promoting development efficiency.

A tray 62 is disposed below the guide rollers 52 and 56, and a tray 64 is disposed below the squeeze roller 60. Pipes 66 and 68 are connected to these trays 62 and 64, respectively,
By opening 0 and 72, the exhausted developer stored in the trays 62 and 64 after development can be discarded. Above the guide plates 54, 58, brush rollers 74, which can move up and down to come in contact with and separate from the plate 10,
76 are provided. The brush rollers 74 and 76 rotate and approach the guide plates 54 and 58 as necessary, rub the plate 10 guided on the guide plates 54 and 58, and rub the non-image portions of the plate. Of the photosensitive layer is removed.

Cleaning spray devices 78 and 80 are disposed upstream of the brush rollers 74 and 76, respectively, so that the brush rollers 74 and 76 can be cleaned. A cleaning spray 82 is also provided on the upstream side of the squeeze roller 60.

In the third section on the downstream side of the squeeze roller 60, the plate material 10 is transported between a pair of guide rollers 84 and 86, respectively. A spray nozzle 88 is disposed at an intermediate portion of the transport path, and performs a finishing process on the plate material 10 passing therethrough. In this third area 18, a water washing treatment, a desensitization treatment and the like are performed as necessary.

Below the third section 18, the tray 9
0,92 are arranged. The tray 90 is connected to a stock tank 116 via a pipe 94 and a valve 96. The tray 92 includes a pipe 106, a valve 10
4 and a pump 118 connected to the stock tank 116. The pump 118 can send the finishing agent in the stock tank 116 to the spray nozzle 88 via the valve 113 and the pipe 111. The plate material 10 that has been treated with the finishing agent is conveyed while the finishing agent is removed by the guide roller 86, and the developing device 1
It is sent out of.

As the conveying roller and the squeezing roller, any material can be used as long as it can withstand the processing chemicals. Preferably, silicone rubber, butyl rubber, ethylene / propylene rubber (EPT / EPDM), acrylonitrile / butadiene rubber (NBR), styrene / butadiene rubber (SBR), polybutadiene rubber (B
R), chloropyrene rubber (CR) and the like can be used.

It is preferable to use a roller containing a fungicide or an antibacterial agent for the conveying roller and the squeezing roller. As the antifungal agent and the antibacterial agent, generally known substances can be used, but preferably, 2- (4-thiazolyl) -benzimidazole (Hokuster HP manufactured by Hokuko Chemical Industry Co., Ltd.) is used.
For example, thiazole-based compounds, thiazoline-based compounds of Amorden SK-950 (trade name, manufactured by Daiwa Chemical Co., Ltd.), and binazine (Vinyzene, trade name, manufactured by Morton Thiokol, USA) can be used. The addition amount of the fungicide and the antibacterial agent is preferably 0.1 to 5% by weight of the rubber roller.

In the automatic developing apparatus 1 having the above-described structure, the excess amount of the developing solution sprayed on the plate material 10 by the spray device 26 in the first area is transmitted to the plate material by the wire bar 22 disposed close to the spray device 26. 10 without being developed. Then, a predetermined amount of the developer is uniformly applied over the entire surface of the plate material 10 by the wire bar 22. The scraped-off developer is hardly deteriorated by fatigue, and is again supplied to the plate material 10 via the spray device 26. Therefore, according to the automatic developing device 1, since the developing process can always be performed with the developer in a good state, the plate material that can be exposed by the infrared laser is developed without causing image defects or the like over a long period of time. be able to. Also, the developer can be saved significantly.

[0043]

The remarkable effects of the present invention will be described below based on examples. (Example 1) [Preparation of positive type lithographic printing plate material] A surface of an aluminum plate (material 1050) having a thickness of 0.3 mm was washed and degreased, and then a nylon brush and a 400 mesh pumistone-water suspension were used. The surface was grained and washed well with water. This plate is immersed in a 25% aqueous solution of sodium hydroxide at 45 ° C. for 9 seconds to perform etching.
% Nitric acid for 20 seconds and washed with water. At this time, the etching amount of the grained surface was about 3 g / m ² . Next, this plate was provided with a 3 g / m ² DC anodic oxide coating at a current density of 15 A / dm ² using 7% sulfuric acid as an electrolytic solution, washed with water, dried, and further treated with a 2.5 wt% aqueous solution of sodium silicate. 3
Treat at 0 ° C for 10 seconds, apply the following undercoat liquid,
The substrate was dried at 0 ° C. for 15 seconds to obtain a substrate. The coating amount of the coating film after drying was 15 mg / m ² .

Undercoat liquid 1 g of the following compound 1 0.3 g methanol 100 g water 1 g

[0045]

Embedded image

The following photosensitive solution [a] was applied to the obtained substrate so that the coating amount was 1.1 g / m ² , to obtain a positive type infrared-sensitive lithographic printing plate material [A]. 80
It was cut to a size of 0 mm and a large number of pieces were prepared. Photosensitive solution [a] Specific copolymer 1 0.75 gm, p-cresol novolak (m, p ratio = 6/4, weight average molecular weight 3,500, unreacted cresol 0.5% by weight) 25 g p-toluenesulfonic acid 0.003 g tetrahydrophthalic anhydride 0.03 g cyanine dye A (structure shown below) 0.017 g dye in which the counter ion of Victoria Pure Blue BOH is 1-naphthalenesulfonic acid anion 0 0.015 g Megafax F-177 (manufactured by Dainippon Ink and Chemicals, Inc., fluorine-based surfactant) 0.05 g γ-butyl lactone 10 g Methyl ethyl ketone 10 g 1-methoxy-2-propanol 1 g

[0047]

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The specific copolymer 1 in the photosensitive solution [a]
Was obtained by the following procedure. In a 500 ml three-necked flask equipped with a stirrer, a condenser and a dropping funnel, 31.0 g (0.36 mol) of methacrylic acid and ethyl chloroformate 39.
1 g (0.36 mol) and 200 ml of acetonitrile were added, and the mixture was stirred while cooling in an ice water bath. To this mixture, 36.4 g (0.36 mol) of triethylamine was dropped by a dropping funnel over about 1 hour. After the addition, the ice-water bath was removed, and the mixture was stirred at room temperature for 30 minutes.

51.7 g (0.30 mol) of p-aminobenzenesulfonamide was added to the reaction mixture, and the mixture was stirred for 1 hour while warming to 70 ° C. in an oil bath. After completion of the reaction, the mixture was added to 1 liter of water while stirring the water, and the resulting mixture was stirred for 30 minutes. The mixture was filtered to remove the precipitate, which was then washed with 500 m of water.
Then, the slurry was filtered and the obtained solid was dried to obtain a white solid of N- (p-aminosulfonylphenyl) methacrylamide (yield 46.9 g).

Next, 4.61 g of N- (p-aminosulfonylphenyl) methacrylamide was placed in a 20 ml three-necked flask equipped with a stirrer, a condenser and a dropping funnel.
92 mol), and 2.94 g (0.02 g) of ethyl methacrylate.
58 mol), 0.80 g (0.015 g) of acrylonitrile
Mol) and 20 g of N, N-dimethylacetamide, and the mixture was stirred while being heated to 65 ° C. in a hot water bath. This mixture was mixed with “V-65” (manufactured by Wako Pure Chemical Industries, Ltd.).
0.15 g was added, and the mixture was stirred for 2 hours under a nitrogen stream while maintaining at 65 ° C. N- (p-
Aminosulfonylphenyl) methacrylamide 4.61
g, 2.94 g of ethyl methacrylate, 0.80 g of acrylonitrile, N, N-dimethylacetamide and "V-
65 "and a mixture of 0.15 g was added dropwise with a dropping funnel over 2 hours. After the addition was completed, the obtained mixture was further stirred at 65 ° C. for 2 hours. After completion of the reaction, methanol (40 g) was added to the mixture, and the mixture was cooled. The obtained mixture was added to 2 liters of water while stirring the water. The mixture was stirred for 30 minutes, and the precipitate was taken out by filtration and dried. 15 g of a white solid was obtained. The weight average molecular weight (polystyrene standard) of this specific copolymer 1 was determined by gel permeation chromatography to be 53,000.
It was 0.

The thus-obtained infrared-sensitive lithographic printing plate material [A] was obtained at an output of 500 mW and a wavelength of 830 n.
Exposure was performed at a main scanning speed of 5 m / sec using a semiconductor laser having an m and a beam diameter of 17 μm (1 / e ² ). Next, a development processing section for supplying a substantially unused developer for each plate so as to spread it almost uniformly on the exposed surface, and after development, squeezing out the tired developer by a roller and discarding it, followed by An automatic developing apparatus including a water washing section and a finishing section was prepared. 8 liters of tap water in the washing tank and FP-2W (Fuji Photo Film Co., Ltd.) in the finishing tank:
8 liters of the finishing gum solution diluted with water = 1: 1 was charged. The thus-prepared automatic developing apparatus is charged with the exposed infrared-sensitive lithographic printing plate [A].
Was developed while supplying 350 ml of the following developer a for each plate. At that time, the washing tank should be filled with 60
The finishing gum tank was replenished with the finishing gum solution in an amount of 40 ml per plate.

Developer b) D-Sorbit 2.5% by weight 1.3% by weight of potassium hydroxide 0.1% by weight of diethylenetriaminepenta (methylenephosphonic acid) 5Na salt 96.1% by weight of water

The exposed infrared-sensitive lithographic printing plate material [A] was processed by the automatic developing apparatus at a rate of 30 plates per day. When the line width of the reference fine line (8 μm) on the lithographic printing plate obtained by this treatment was measured, no change was observed from the start of the treatment to one month after the treatment. In addition, a part of the obtained lithographic printing plate was extracted and the following test was performed.
Printing skills were evaluated.

(Printing durability test) Among the printing plates obtained as described above, the plates treated on the first, fifth, tenth, fifteenth, twenty-fifth, twenty-fifth, and thirty-day Was applied to a printing machine Lithrone manufactured by Komori Corporation, and printing was performed using a commercially available black ink. At this time, the number of normal printed matter obtained (the number of printed sheets until the image on the printing plate was worn and sufficient ink did not adhere and the density of the printed matter became insufficient) was evaluated. Table 1 shows the results.

(Ink Adhesion Test and Hardness Test on Leaving) The plate treated on the same day as that used in the printing durability test was
Applying to a printing machine SOR-M manufactured by Heidel Co., Ltd., 10,000 sheets were printed with a commercially available red ink. At this time, it was examined how many good prints could be obtained from the start of printing (ink adhesion test). Also, temporarily stop the printing press,
After being left as it is for one hour, printing was started again. At this time, the number of printed sheets until a beautiful printed matter free of stains was obtained was evaluated and evaluated as follows (a test for the resistance to standing stains). Table 1 shows the results. ：: Within 30 sheets. Δ: Within 60 sheets. ×: Within 100 sheets. XX: Cleaner wiping is required.

For comparison, development processing was performed using an automatic developing apparatus of the type in which an image-recorded plate material was conveyed and immersed in a developer stored in a developing tank, 900NP manufactured by Fuji Photo Film Co., Ltd. Then, a part of the obtained printing plate was extracted, and the printing skill was evaluated. Table 2 shows the results.

[0057]

[Table 1]

[0058]

[Table 2]

The effects of this embodiment are clear from Tables 1 and 2. As shown in Table 1, in Example 1, good results were obtained in all of the printing durability, the ink deposition property, and the resistance to standing stains. As shown in Table 2, in Comparative Example 1, development failure occurred from the 15th day, and stains occurred in the printing execution evaluation.

Example 2 The following photosensitive solution [b] was applied to the same substrate as in Example 1 so that the coating amount was 1.0 g / m ² , and an infrared-sensitive lithographic printing plate material [B] was applied. Obtained. Photosensitive solution [b] Specific copolymer 10.4 gm, p-cresol novolak (m, p ratio = 6/4, weight average molecular weight 3,500, unreacted cresol 0.5% by weight) 6 g p-Toluenesulfonic acid 0.003 g Tetrahydrophthalic anhydride 0.03 g Cyanine dye B (structure shown below) 0.017 g Ethyl violet (Orient Chemical Industry Co., Ltd.) has a counter ion of 1-naphthalene sulfone Dye converted to acid anion 0.015 g Megafax F-177 (manufactured by Dainippon Ink and Chemicals, Inc., fluorine-based surfactant) 0.05 g γ-butyl lactone 10 g Methyl ethyl ketone 10 g 1-methoxy-2-propanol 3 g

[0061]

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The thus-obtained infrared-sensitive lithographic printing plate [B] was subjected to the same exposure and development treatment as those of the lithographic printing plate [A] of Example 1. When the line width of the reference fine line (8 μm) on the lithographic printing plate obtained by this treatment was measured, no change was observed from the start of the treatment to one month after the treatment. From the resulting lithographic printing plate, beautiful prints can be obtained with only 15 sheets from the start of printing.
In addition, good results were obtained stably in both printing durability and stain resistance.

(Example 3) [Preparation of negative type lithographic printing plate material] JI having a thickness of 0.3 mm
After degreasing the surface of the SA1050 aluminum plate,
Using a nylon brush and a 400 mesh pumicestone-water suspension, the surface was grained and washed well with water.
This plate was immersed in a 25% aqueous sodium hydroxide solution at 45 ° C. for 9 seconds to perform etching, washed with water, and further washed with 2% HNO 3.
₃ for 20 seconds and washed with water. At this time, the etching amount of the grained surface was about 3 g / m ² . Next, this plate was subjected to a current density of 15 A / dm using 7% H ₂ SO ₄ as an electrolytic solution.
After providing a 3 g / m ² direct current anodic oxide film at ² , the sample was washed with water and dried. Next, the following undercoat liquid was applied to this aluminum plate, and dried at 80 ° C. for 30 seconds. The coating amount after drying is 1
It was 0 mg / m ² .

Undercoat liquid 2-aminoethylphosphonic acid 0.5 g Methanol 40 g Pure water 60 g

Next, the following solution [n] was prepared, and this solution was applied to the above-mentioned primed aluminum plate.
After drying at 0 ° C. for 1 minute, a negative type lithographic printing plate material [N] was obtained. The coating amount after drying was 1.5 g / m ² . Solution [n] Maruka Linker MH-2P 1.4 g (Poly (p-hydroxystyrene) manufactured by Maruzen Petrochemical Co., Ltd.) Crosslinking agent [KZ-1] 0.6 g Infrared absorbing dye [IK-1] 0.2 g Acid generator [SH-1] 0.2 g Victoria pure blue naphthalene sulfonate 0.04 g Megafac F-177 0.04 g (Fluorine-based surfactant manufactured by Dainippon Ink and Chemicals, Inc.) Agent) methyl ethyl ketone 10 g methanol 7 g 1-methoxy-2-propanol 10 g

The chemical formulas of the crosslinking agent [KZ-1], the infrared absorbing dye [IK-1] and the acid generator [SH-1] are shown below.

[0067]

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[0068]

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[0069]

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The obtained negative type lithographic printing plate material [N] was
Infrared laser exposure system by Creo Corporation, Trend
Image exposure was performed by adjusting the plate surface energy to 130 mJ / m ² using dsetter 3244MT. After exposure, W
It was heated at 140 ° C. for 60 seconds in an SPC-MINI oven manufactured by isconsin Oven Corporation. After heating, a developing solution manufactured by Fuji Photo Film Co., Ltd., DP-4 was used by using an automatic developing apparatus having a configuration shown in FIG. 1 and capable of supplying 300 cc of a substantially unused developing solution for each plate.
Using a 1: 8 dilution of a developer as a developer, a size of 1030 ×
Each of the 800 mm plates was processed for eight months for one month. When the line width of the reference fine line (8 μm) on the lithographic printing plate obtained by this treatment was measured, no change was observed from the start of the treatment to one month after the treatment. Further, a part of the obtained lithographic printing plate was sampled, the following test was performed, and the printing skill was evaluated.

(Printing durability test) Among the printing plates obtained as described above, the plates treated on the first, fifth, tenth, fifteenth, twenty-fifth, twenty-fifth, and thirty-day Was applied to a printing machine Lithrone manufactured by Komori Corporation, and printing was performed using a commercially available black ink. The number of normal printed matter obtained at this time was evaluated. Table 3 shows the results.

(Test for resistance to standing stains) A plate treated on the same day as that used in the printing durability test was applied to a printing machine SOR-M manufactured by Heidel Co., Ltd., and 2,000 sheets were printed with a commercially available red ink. did. Thereafter, the printing press was once stopped, left as it was for one hour, and then printing was started again. At this time, how the ink was removed from the non-image area (the speed at which the stain on the non-image area was removed) was visually evaluated as follows. ：: The non-image area was quickly dispensed with ink. Δ: The ink was removed from the non-image area slightly later. ×: The ink was removed very slowly in the non-image area. Table 3 shows the results.

For comparison, development processing was performed using an automatic developing apparatus of the type in which an image-recorded plate material was conveyed and immersed in a developing solution stored in a developing tank, 900NP manufactured by Fuji Photo Film Co., Ltd. Extract a part of the obtained printing plate,
Printing skills were evaluated. Table 4 shows the results.

[0074]

[Table 3]

[0075]

[Table 4]

From Tables 3 and 4, the effect of this embodiment is clear. As shown in Table 3, in the printing durability test, in Example 3, all the plates could print 95,000 to 105,000 sheets and could maintain stable printing durability. In addition, in the test for difficulty in leaving stains, in Example 3, the ink was quickly removed from all the plates, and the stains were able to be maintained stably. As shown in Table 4, in Comparative Example 2, the development gradually became excessive, and the printing durability was lowered.

[0077]

As described above in detail, according to the developing method of the present invention, a plate material that can be exposed by an infrared laser can be developed for a long period of time without causing image defects or the like.

[Brief description of the drawings]

FIG. 1 is a diagram showing processing equipment capable of implementing the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Plate material (photosensitive lithographic printing plate material) 14 1st area 16 2nd area 18 3rd area 22 Wire bar (measuring means) 24 Guide roller 26 Spray device 60 Squeeze roller

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Keitaro Aoshima 4,000 Kawajiri, Yoshida-cho, Haibara-gun, Shizuoka Pref.

Claims (1)

[Claims] 1. A method for developing a photosensitive lithographic printing plate material that can be exposed by an infrared laser, comprising: using an automatic developing device that applies a predetermined amount of a substantially unused developing solution to each plate material. A method for developing a photosensitive lithographic printing plate material, comprising developing the plate material.