JP2000241986A - Apparatus for processing photosensitive planographic printing plate material and processing method for same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for processing a printing plate material in which the printing plate material capable of exposure with IR laser can be washed after development without forming a deposit on the surface of the printing plate material. SOLUTION: The apparatus 10 for processing a photosensitive planographic printing plate material 12 which is made alkali-soluble by IR laser light has a developing part 18 in which the printing plate material 12 is developed by supplying a developer to the printing plate material 12, a weighing means 40 which weighs the developer sticking to the surface of the printing plate material 12 conveyed from the developing part 18 and leaves a prescribed amount of the developer on the surface of the printing plate material 12 and a washing part 24 in which the remaining developer on the surface of the printing plate material 12 conveyed from the weighing means 40 is washed off.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing apparatus and a processing method for a photosensitive lithographic printing plate material, and more particularly, to a photosensitive lithographic printing plate material which becomes alkali-soluble by a reaction other than a chemical reaction by infrared laser light. The present invention relates to a processing device and a processing method.

[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 positive type image recording material comprising a binder such as a cresol resin, a substance that absorbs light and generates heat, and a substance such as quinonediazide that substantially reduces the solubility of the binder is proposed. Have been. In the positive-type image recording material, a substance that absorbs light and generates heat generates heat in the exposed portion, thereby expressing the solubility of the exposed portion.

[0004] 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, an image is recorded on a plate material by infrared laser exposure, and then a development process is performed.

In general, when developing a plate material, an automatic developing apparatus provided with a developing section and a washing section is widely used. In the development processing section, the plate material is immersed in a developer stored in a developing tank, and the photosensitive layer in the non-image portion of the plate material is removed by elution. Next, the plate material is carried out of the developing tank, the plate material is squeezed by a squeezing roller including a pair of rollers having a smooth surface, and the developer adhering to the plate material surface is squeezed. Then, in the washing section disposed downstream of the developing section and the squeezing roller, water is supplied to the surface of the plate material to wash away the developer remaining on the surface of the plate material.

[0006]

The above-mentioned positive type image recording material recordable by infrared laser exposure is used as a plate material, and after the image is recorded on the plate material by infrared laser exposure, the above-mentioned automatic image recording is performed. When a developing process was performed by a developing device, an image defect often occurred on the plate material. The cause is that precipitates are generated on the surface of the plate material,
This is because the plate material is liable to have a defect when there is a precipitate. Such precipitates included a binder resin and the like contained in the components of the photosensitive layer.

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 develop a plate material that can be exposed by an infrared laser and then to form the plate material without forming a precipitate on the surface of the plate material. It is an object of the present invention to provide a processing apparatus and a processing method for a photosensitive lithographic printing plate material which can be washed with water.

[0008]

Means for Solving the Problems As a result of intensive studies, the present inventor has found that a plate material that can be exposed by infrared laser exposure is taken out of a developing tank in a development processing section and passed through a squeezing roller. It has been found that a swelled photosensitive layer adheres to the surface of the laser-exposed portion without being completely eluted in the developer. Furthermore, it has been found that when water is supplied to the exposed portion in the washing section, a precipitate of a photosensitive layer component is generated.

When the concentration of the developing solution is increased or the temperature is increased in order to completely elute the photosensitive layer components in the exposed portion in the developing portion, the plate material recordable by infrared laser exposure has low dissolution resistance. Therefore, the non-exposed portion (image portion) is also dissolved to cause an image defect.

As a result of further intensive studies, the present inventor has found that
It has been found that the formation of precipitates can be significantly suppressed by leaving a predetermined amount of the developing solution on the surface of the plate material conveyed to the washing section. That is, the present invention provides a processing apparatus for a photosensitive lithographic printing plate material which is alkali-soluble by infrared laser light, wherein a developing solution is supplied to the plate material to develop the plate material, Measuring means for measuring a developing solution attached to the surface of the plate material transported from the surface of the plate material and leaving a predetermined amount of the developing solution on the surface of the plate material; and remaining on the surface of the plate material transported from the measuring means. And a rinsing section for washing away the developing solution.

Here, "a photosensitive lithographic printing plate material which becomes alkali-soluble by infrared laser light" means a plate material which becomes alkali-soluble by a reaction excluding a photochemical reaction induced by irradiation with infrared laser. And a plate material that forms a positive image by removing the composition in the exposed area by development (hereinafter, referred to as a “positive plate material”). The term "measuring means" refers to a squeezing roller or the like which is disposed downstream of the developing section and includes a pair of rollers having a special non-smooth surface. As a special surface form, for example, embossing can be performed or a spiral groove can be formed on at least the surface of the pair of rollers constituting the squeezing roller, which is in contact with the image surface side of the plate material. Any material can be used as long as the developer can be left substantially uniformly on the surface of the plate material.

The amount of the developer remaining on the plate material by the measuring means is preferably 10 to 100 ml / m ² , more preferably 10 to 50 ml / m ² . When the residual amount of the developer is less than 10 ml / m ² , the effect of suppressing the formation of precipitates becomes insufficient. Further, when the residual amount of the developer is 1
When it exceeds 00 ml / m ² , the fatigue of the washing water in the washing processing part becomes early. In particular, when running water is washed in the washing section, a large amount of developer components are contained in the waste liquid, which is not preferable in terms of environmental conservation.

According to such a plate material processing apparatus, a predetermined amount of the developing solution remains on the surface of the plate material that has passed through the measuring means. It is moderated, and the generation of precipitates caused by a rapid decrease in pH can be significantly suppressed. Therefore, after developing the plate material that can be exposed by the infrared laser, the plate material can be washed with water without generating a precipitate on the surface of the plate material.

The present invention also relates to a method for treating a photosensitive lithographic printing plate material which becomes alkali-soluble by a reaction other than a chemical reaction by infrared laser light, wherein a developing solution is supplied to the plate material to develop the plate material. Then, the developer adhering to the surface of the plate is measured, a predetermined amount of the developer is left on the surface of the plate, and the developer remaining on the surface of the plate is washed away.

Examples of the photosensitive lithographic printing plate material to which the present invention is applied include the positive image recording materials described in JP-A-7-285275 described above.

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.

More preferred alkaline agents include buffers 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 13.6 are particularly preferable.
Those having 1.0 to 13.6 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.

[0019] 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 as necessary for the purpose of accelerating developability, dispersing development scum, and increasing the ink affinity of the 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 further contain various additives known in the art as needed. 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 above-described developer allows the generation of precipitates to be more remarkably suppressed.

[0031]

Embodiments of the present invention will be described below in detail with reference to the drawings. Automatic developing apparatus 1 shown in FIG.
In the case of No. 0, the positive plate material 12 on which an image is recorded by an infrared laser exposure device (not shown) is developed.

First, the outline of the automatic developing apparatus will be described. The automatic developing device 10 includes a developing unit 18, a measuring unit 40 for leaving a predetermined amount of a developing solution on the surface of the plate 12, a washing unit 24 for washing the developing solution remaining on the plate 12 with water, and a washing unit 24. A finisher 26 for applying a gum solution to the subsequent plate 12 to desensitize it, and a drying unit 16 for drying the plate 12
And The developing section 18 includes the developing tank 14, the washing section 24 includes a washing tank 28, and the finisher section 26 includes a gum solution tank 30.

The outer panel 20 on the side of the developing section 18 is provided with a slit-shaped insertion opening 22 into which the plate 12 is inserted. A pair of transport rollers 32 is provided inside the insertion port 22, and the plate material 12 inserted from the insertion port 22 is nipped and transported by the transport rollers 32,
The developer is fed toward the developing tank 14 at a predetermined angle with respect to the horizontal direction.

The developing tank 14 has a substantially inverted mountain shape having an upper opening and a bottom center protruding downward. The developing tank 14 has an upstream portion along the transport direction of the plate material 12. In order from the side, a pair of the transport roller 34 and the brush roller 3
6, 38 and a squeeze roller 40 as a measuring means are provided. These transport rollers 34, brush rollers 3
6, 38 and the aperture roller 40 are rotated by a drive mechanism (not shown).

Further, backup rollers 44 and 46 are disposed opposite to each other with the brush roller 36 interposed therebetween, and a backup roller 48 is disposed opposite the brush roller 38. These backup rollers 44, 46,
The drive force is not transmitted to 48, and it is rotatable.

In the developing section 18, the developing solution in the developing tank 14 is sucked through a joint pipe 50 provided on the bottom wall, and is discharged through a discharge port (not shown) formed in the side wall. The developer is discharged into the circulator 14 to circulate and agitate the developer. The sealing structure of the developing unit 18 will be described later.

The plate material 12 carried out of the developing tank 14 is weighed by scraping off the excess amount of the developer adhering to its surface by a squeeze roller 40 as measuring means, and then conveyed to the water washing section 24. You. Details of the aperture roller 40 will be described later.

In the washing section 24, a pair of transport rollers 54 and 56 are disposed above the washing tank 28, respectively. These transport rollers 54 and 56 are rotatably supported by side plates, and the driving force of the driving unit is transmitted to the developing unit 18.
The transport path of the plate material 12 sent from the printer is formed.

Further, a spray pipe 58 is disposed between the transport rollers 54 and 56 so that the spray port is directed toward the transport path. Rinsing water pumped up by a pump from a rinsing water tank (not shown) is ejected from the spray pipe 58, and the front and back surfaces of the printing plate 12 are washed with the rinsing water. The washing water after washing flows to the washing tank 28.

A pair of squeezing rollers 60 are provided above the gum solution tank 30 of the finisher unit 26, which is a desensitizing unit downstream of the washing unit 24. Then, the plate material 12 sent out by the transport roller 56 is sent to the squeezing roller 60. On the upstream side of the squeezing roller 60, a spray pipe 62 is vertically opposed to each other, and the ejection port is directed to the transport path. From the spray pipe 62, the gum solution sucked by the pump from the gum solution tank 30 is jetted out and applied to the front and back surfaces of the printing plate 12.

Thereafter, the plate material 12 on which the gum solution has been uniformly applied by the squeezing roller 60 is guided to the drying unit 16 through a passage opening 66 opened and closed by a shutter 64. In the drying section 16, the dried plate material 12 conveyed by the guide roller 68 and the pair of skewer rollers 70 and 72 and dried is discharged out of the automatic developing device 10 through the discharge port 74.

Next, the sealed structure of the developing section will be described. The developing section 18 is provided with a box-shaped shielding lid 76 supported by a support section provided on the tank wall of the developing tank 14. The bottom wall 76 </ b> A of the shielding lid 76 includes the transport roller 34 and the brush roller 3.
6. It is continuously curved in an arc shape so as not to come into contact with the upper outer peripheral surface of the backup roller 48, so that it does not interfere with the roller or the like.

The width dimension of the bottom wall 76A is
Are substantially the same as the inner dimensions of the side plates constituting the bottom wall 7.
The liquid surface is not exposed from the gap between 6A and the side plate. Further, the peripheral wall of the shielding lid 76 extends to a cover 78 that covers the upper part of the automatic developing device 10. The cover 78 is formed with, for example, a rectangular groove. When the shielding lid 76 is set on the developing tank 14 and covered with the cover 78, the groove and the upper part of the peripheral wall are engaged, and the upper part of the developing tank 14 is engaged. Seal completely. Also, a convex portion may be formed instead of the groove to engage with the upper part of the peripheral wall.

In the above configuration, the flow of air above the developer (the flow of air from the insertion port 22 to the discharge port 74) is completely blocked by the peripheral wall of the shielding lid 76 and the cover 78. Therefore, the degree of sealing of the developing unit 18 is increased, and no new carbon dioxide gas flows. Therefore, the deterioration of the developer due to the carbon dioxide gas is suppressed, and the developing process can always be performed with the developer in a good state.

The transport roller 34 and the brush roller 3
6, 38, and the transfer means such as the backup rollers 44, 46, and 48 are disposed in the substantially sealed developing tank 18, so that the surface of the transfer means does not dry.
No precipitate adheres to the surface. In this specification, “substantially sealed” means, for example, when an opening is provided as a plate material insertion port in the wall of a developing tank or another processing tank communicating with the developing tank, except when the plate material is inserted. By closing the openings to prevent air from freely entering and exiting the developing tank.
A closed state that can be achieved by floating a floating lid or the like on the liquid surface of the developer stored in the developing tank in order to reduce contact between the air and the developer. Needless to say, the degree of sealing of the developing tank may be higher than these sealed states.

Therefore, the high development processing ability of the automatic developing apparatus 10 is maintained, and the positive plate material 12 that can be exposed by the infrared laser can be developed for a long period of time without causing image defects or the like. The replenisher is replenished in the developer so that the liquid level of the developer is always above the bottom wall 76A of the shielding lid 76. This creates a space below the bottom wall 76A and prevents air from entering.

Further, a rubber blade 90 is provided from one side plate to the other side plate in contact with the pair of conveying rollers 32 and the squeezing rollers 40 and 60, and a shutter 64 is provided in the passage opening 66. The degree of sealing of the portion 18 is further increased, and the deterioration of the developer due to carbon dioxide gas and the evaporation of water in the developer are further suppressed.

Further, by providing the developing cover 18 with the shielding cover 76, a portion of the cover 78 where moisture is condensed on the rear surface is reduced, so that the condensed water drops fall on the conveyed plate material 12 to be conveyed. , The occurrence of mold due to the condensed water droplets adhering to the upper part of the side plate and the like, and the dirt of clothes caused by the water droplets generated when the cover 78 is opened can be prevented.

The insertion port 22 may be provided with a rubber blade 21 for preventing air from flowing into the developing section 18. In the above-described configuration, the box-shaped hollow shielding lid is used. However, the present invention is not limited to this, and a solid shielding lid may be used, as long as the sealing degree of the developing tank is increased.

Next, the details of the aperture roller 40 will be described.
The squeezing roller 40 has a rough surface, which is at least one of the pair of rollers 40a and 40b that is in contact with the image surface side of the plate material. In this specification, "rough surface" means a surface other than a smooth surface, in other words,
A surface on which a developer can be substantially uniformly left on a plate material surface. For example, the surface includes an embossed surface, a surface in which grooves are spirally formed, a surface in which grooves are formed at predetermined intervals in the roller axial direction, and the like.

The material of the squeeze roller 40 and the other transport rollers may be any 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), 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 squeezing roller and the transport roller. As the fungicides and antibacterial agents, those known in the first edition can be used, but preferably, 2- (4-thiazolyl) -benzimidazole (Hokuster H manufactured by Hokuko Chemical Industry Co., Ltd.)
P) and the like, thiazoline based on Amorden SK-950 (trade name, manufactured by Daiwa Chemical Co., Ltd.), and binazine (Vinyzene, trade name, available from Morton Thiokol, USA) can be used.

In this embodiment, as shown in FIG. 1, a pair of rollers 40
One of the rollers 40a and 40b (the lower roller in FIG. 1) 40b is immersed in the developer.

According to the above configuration, the plate material 12 carried out of the developing tank 14 is provided with the roller 40 having a rough surface.
The excess amount of the developer adhering to the surface of the squeezing roller 40 is scraped off by the squeezing roller 40 and weighed, and then conveyed to the washing section 24. Therefore, a predetermined amount (for example, 10 to 100 ml) is applied to the surface of the plate material 12 that has passed through the squeezing roller 40.
/ M ² ) of the developing solution is left, so that the rapid drop in the pH of the exposed area in the washing section 24 is alleviated, and the formation of precipitates due to the rapid drop in pH can be remarkably suppressed.

Since one roller 40b of the pair of rollers constituting the squeezing roller 40 is immersed in the developing solution,
The developer can be measured while supplying a sufficient amount of the developer to the plate material 12. Therefore, the squeezing roller 40
The developer can be uniformly left on the surface of the plate material 12 that has passed through.

The automatic developing apparatus 10 according to the present embodiment
Is a roller 40a having a rough surface formed by replacing a roller having a smooth surface in an aperture roller of an existing automatic developing apparatus
It can be configured simply by replacing it. Therefore, the existing automatic developing device can be easily changed to the automatic developing device 10 of the present embodiment, so that the equipment cost can be significantly reduced. Further, by replacing the roller, the residual amount of the developer can be easily changed.

[0057]

The remarkable effects of the present invention will be described below based on examples. (Example 1) [Preparation of plate material for positive type lithographic printing] After cleaning the surface of an aluminum plate (material 1050) having a thickness of 0.3 mm with trichloroethylene and degreased, a nylon brush and a 400 mesh pumice water suspension were used. The surface was grained using 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.
After washing with water, it was further immersed in 20% nitric acid for 20 seconds and washed with water. At this time, the etching amount of the grained surface is about 3 g / m.
^{Was 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. Hydrophilic treatment was performed at 30 ° C. for 10 seconds, the following undercoating solution was applied, and the coating film was dried at 80 ° C. for 15 seconds to obtain a substrate. The coating amount of the coating film after drying was 15 mg / m ² .

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

[0059]

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The following substrate was coated with the following photosensitive solution [a] at a coating amount of 1.8 g / m ² to obtain a positive type infrared-sensitive lithographic printing plate material [A].
It was cut into mm size to prepare a large number of pieces. 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

[0061]

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The specific copolymer 1 in the photosensitive solution [a] was used.
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.

To this reaction mixture was added 51.7 g (0.30 mol) of p-aminobenzenesulfonamide, and the mixture was stirred for 1 hour while being heated 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 infrared-sensitive lithographic printing plate material [A] thus obtained was subjected to an output of 500 mW, a wavelength of 830 nm,
Exposure was performed at a main scanning speed of 5 m / sec using a semiconductor laser having a beam diameter of 17 μm (1 / e ² ). Next, the following developer a (pH about 13) was placed in the developing tank of the automatic developing apparatus shown in FIG.
Was charged and kept at 30 ° C. 8 liters of tap water in the second bath and FP-2W (manufactured by Fuji Photo Film Co., Ltd.): Water = 1:
8 liters of the 1-diluted finishing gum solution was charged.

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 squeezing roller 40a is provided with an embossing roller (a surface having a diameter of 5 mm and a depth of 1 mm).
(A silicon roller having about 20,000 recesses per square meter) was mounted, and a lower roller 40b was provided with the same silicon rubber smooth roller.

Using this automatic developing apparatus, the exposed infrared-sensitive lithographic printing plate material [A] was processed 50 plates per day with the front side (the side having the photosensitive layer) facing upward. At that time, 30 ml per plate, 250 ml per hour of automatic machine operation, 80 ml per stop hour of the following replenisher A, 60 ml water per plate in the second bath, and 3 ml bath in the third bath FP-2W: water = 1: 1 dilution gum solution was replenished at 40 ml per plate.

Development replenisher D-Sorbit 5.6% by weight Potassium hydroxide 2.5% by weight Diethylenetriaminepenta (methylenephosphonic acid) 5Na salt 0.2% by weight Water 91.7% by weight

In the lithographic printing plate obtained by this treatment, a neat printing plate was obtained without deposits in the washing section. At this time, an average of 17 ml / m ² of developer remained on the front side of the printing plate passed through the squeeze rollers 40a and 40b.

Example 2 The following photosensitive solution [b] was applied to the same substrate as in Example 1 so that the coating amount was 1.8 g / m ² , to obtain an infrared-sensitive lithographic printing plate material [B]. Was. 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

[0072]

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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. With the lithographic printing plate obtained by this treatment, a beautiful printing plate could be obtained without any residue attached to the printing plate surface.

(Comparative Example) In Example 1, the roller 40
A similar process was performed under the same conditions as in Example 1 except that a smooth roller made of the same material was used instead of the embossing roller of a. As a result, scum precipitates in the washing section and is transferred to the plate,
Attached. The residue could not be removed by printing, but the ink adhered and the printed matter was stained.

[0075]

As described above in detail, according to the present invention, after a plate material which can be exposed by an infrared laser is developed, the plate material is washed with water without forming a precipitate on the surface of the plate material. be able to.

[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 Automatic developing apparatus 12 Plate material (photosensitive lithographic printing plate material) 14 Developing tank 16 Drying part 18 Developing part 22 Insertion port 24 Rinsing part 26 Finisher part 34 Transport roller (transport means) 36, 38 Brush roller 40 Squeeze roller 76 Shield Lid 78 Cover 90 Rubber blade

Claims (2)

[Claims] An apparatus for processing a photosensitive lithographic printing plate material which is alkali-soluble by infrared laser light, comprising: a developing processing unit for supplying a developing solution to the printing plate material to develop the printing plate material; Measuring means for measuring a developing solution attached to the surface of the plate material transported from the surface of the plate material and leaving a predetermined amount of the developing solution on the surface of the plate material; and remaining on the surface of the plate material transported from the measuring means. A photosensitive lithographic printing plate material processing apparatus, comprising: a water washing section for washing away the developed developer. 2. A method of processing a photosensitive lithographic printing plate material which becomes alkali-soluble by infrared laser light, wherein a developing solution is supplied to the plate material to develop the plate material and adhere to the surface of the plate material. A method for treating a photosensitive lithographic printing plate material, comprising weighing a developer, leaving a predetermined amount of the developer on the surface of the plate material, and washing away the developer remaining on the surface of the plate material.