JP3214945B2 - Lithographic printing plate manufacturing method and manufacturing apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithographic printing plate, in which a printing original plate on which an image is exposed is heated on a photosensitive layer, and then a non-image portion other than an image portion is removed (hereinafter referred to as etching). It relates manufacturing method and manufacturing apparatus.

[0002]

2. Description of the Related Art Today, lithographic offset printing plates include:
Positive photosensitizers containing diazo compounds and phenolic resins as main components, and PS plates using negative photosensitizers containing acrylic monomers or prepolymers as main components have been put into practical use. For this reason, a film master on which an image has been recorded in advance is subjected to close contact exposure to make a plate. On the other hand, due to advances in computer image processing, large-volume data storage, and data communication technology, in recent years, computer operations have been consistently performed from document input, correction, editing, layout to page set, and real-time remote control via high-speed communication networks and satellite communications. An electronic editing system that can output to the terminal plotter on the ground has been put into practical use. In particular, the demand for an electronic editing system is high in the newspaper printing field, which requires immediacy. In addition, even in fields where original documents are currently stored in the form of films and printing plates are duplicated as necessary, originals are being developed along with the development of large-capacity recording media such as optical disks. It is considered that these recording media will be stored as digital data. However, a direct printing plate for directly producing a printing plate from the output of a terminal plotter has hardly been put to practical use. Even when an electronic editing system is operating, the output is performed on a silver halide photographic film, and this is used as a PS plate. The fact is that a printing plate is prepared by contact exposure to a substrate. One of the reasons is that it is difficult to develop a direct type printing plate having a sensitivity high enough to produce a printing plate in a practical time by a light source of an output plotter (for example, a He-Ne laser, a semiconductor laser, or the like). Was the cause.

An electrophotographic photoreceptor is considered as a photoreceptor having high photosensitivity capable of providing a direct printing plate. As a method of preparing a printing plate using electrophotography, a method of removing a photoconductive layer in a non-image portion after forming a toner image is already known. For example, Japanese Patent Publication No. 37-17162 and 38-6
No. 961, No. 38-7758, No. 41-2426,
Nos. 46-39405, JP-A-50-19509, JP-A-50-19510, JP-A-52-2437, and JP-A-54-1
No. 45538, No. 54-134632, No. 55-10
No. 5254, No. 55-153948, No. 55-161
No. 250, No. 57-147656, No. 57-1618
No. 63, for example, an electrophotographic printing plate precursor. In the above method, a binding resin that dissolves in an alkaline solvent or swells and releases is used as a binding resin of the electrophotographic photoreceptor, and the hydrophilic surface is exposed by removing a portion other than the toner image portion using the toner image as a resist. ,
A lithographic printing plate.

In producing the printing plate, after developing the toner by electrophotography, the toner can be fixed by a known fixing method such as heat fixing, pressure fixing, and solvent fixing. In order to make the layer act as a resist to the etching solution, it is preferable to form a complete film by heating or a solvent. When a solvent or the like is used, there are problems such as the hermeticity of the apparatus, disposal, and adverse effects on the environment. As an actual fixing method, heat fixing can be preferably used. In the next etching step, the swelling or elution rate of the photoconductive layer varies significantly depending on the temperature of the etching solution. That is, as the etching temperature increases, the elution rate increases, and the image portion becomes extremely thin due to side etching. In addition, when the temperature is lowered, the etching of the non-image portion becomes insufficient, resulting in contamination during printing. In order to prevent this and always maintain a stable image and printing performance, it has been proposed to cool the printing original plate to a certain temperature after heating and fixing, and to convey it to an etching step.
As a cooling method, contact with a liquid such as water, a gas such as air, or various metals can be considered, and contact with a liquid such as water is preferably used in terms of cooling speed, uniformity, low cost, and the like.

[0005] However, when a printing plate is prepared by the above-described process, if it is used for a long time, spot-like stains are generated on the surface of the printing plate, which may not be practical. The present inventors have conducted intensive studies to solve this, and as a result, when a liquid such as water is used in the cooling step, microorganisms such as bacteria, fungi, algae, and the like grow on the printing original plate, and spots are formed. It was found that defects occurred. In addition, microorganisms such as bacteria, molds, and algae generated in the cooling step not only cause image defects but also cause clogging of the cooling pipe, that is, cause offensive odor and the like, which is a problem to be solved practically.

[0006]

SUMMARY OF THE INVENTION The inventor of the present invention has been made in view of the above circumstances, and an object of the present invention is to use a cooling liquid mainly composed of water for a long period of time during the manufacturing process of a lithographic printing plate. An object of the present invention is to provide a method and an apparatus for manufacturing a lithographic printing plate that can stably obtain high-quality images without causing image defects due to microorganisms.

[0007]

SUMMARY OF THE INVENTION The object of the present invention is to provide a first step of heating an image-exposed printing plate precursor,
A second step of cooling the printing original plate,
A third step of removing the photosensitive layer other than the image on the printing original plate;
In the method and apparatus for manufacturing a lithographic printing plate,
The third step provided between the first step and the third step;
In two steps, preservative, at least one of fungicides and fungicides, in particular, at least one selected from phenolic compounds, thiazole and isothiazole compounds, organic bromide compounds, quaternary ammonium salt compounds A method of cooling the printing original plate using a cooling liquid containing the method and
This could be achieved with the device .

[0008]

The electrophotographic lithographic printing plate to which the present invention is applied is formed by forming a toner image, fixing by heating and removing the photoconductive layer in the non-image area by a conventionally known method. That is,
It is charged substantially uniformly in a dark place and forms an electrostatic latent image by image exposure. As an exposure method, a semiconductor laser, He-
Scanning exposure by Ne laser or xenon lamp,
Reflection image exposure using a tungsten lamp, a fluorescent lamp or the like as a light source, contact exposure through a transparent positive film, and the like can be mentioned. Next, the electrostatic latent image is developed with toner. As the developing method, various conventionally known methods such as cascade development, magnetic brush development, powder cloud development, and liquid development can be used. Among them, liquid development is capable of forming a fine image and is suitable for preparing a printing plate. In addition, it is possible to use either a normal development in which toner is attached to a non-exposed portion or a reversal development in which toner is attached to an exposed portion.

The formed toner image is heated by a known heating method,
For example, heat fixing is performed by contact with a lamp heater, a ceramic heater, heated air, a heated metal, or the like. If necessary, it can be used in combination with pressure fixing. The heating temperature varies depending on the toner and the photoconductive layer, and cannot be specified unconditionally. However, the fixing is preferably performed at 40 ° C. to 300 ° C., more preferably 70 ° C. to 200 ° C.
It is good to fix at ℃. The printing plate thus fixed is brought into contact with the liquid and cooled. Although various liquids can be used as the liquid, it is preferable to use a cooling liquid mainly composed of water in consideration of pollution, odor and influence on the etching step. As the temperature of the printing original plate, it is preferable to cool from 10 ° C to 60 ° C, and further from 20 ° C to 40 ° C. The lithographic printing plate is prepared by using the fixed and cooled toner image as a resist and removing the electrophotographic photosensitive layer in the non-image area with an etching solution.

Further, there is a photopolymerization type image forming method as a lithographic printing plate manufacturing method including a heating-cooling-etching step to which the present invention can be applied other than the electrophotographic method. In this method, an image is formed by exposing an image with an actinic ray and then heating to elute a non-image portion. Specifically, there are known image forming methods described in JP-A-2-89055, JP-A-2-103051, German Patent 4013358A1, and the like. However, when the heated image forming material is directly conveyed to the elution section, the temperature of the elution section rises, and the elution speed of the non-image section changes, making it difficult to always obtain a constant image. Requires a cooling step.

In addition, the present invention can be applied to lithographic printing plate production by a silver sensor polymerization type image forming method. That is, this is a highly sensitive image forming method in which polymerization is started using a silver salt to form an image. In this method, an image is formed by exposing an image with an actinic ray and then heating to heat develop the silver salt, and further elute the non-image portion. Specifically, JP-A-3-18854 and JP-A-3-204
No. 650, Japanese Patent Application No. 2-295834, Japanese Patent Application No. 3-131788, Japanese Patent Application No. 3-131789, Japanese Patent Application No. 3-131790, Japanese Patent Application No. 3-131.
An image forming method described in JP-A-791 and the like is known.
In these cases, similarly to the above, when the heated image forming material is directly carried into the elution portion, the temperature of the elution portion rises, and the elution speed of the non-image portion changes, so that it is difficult to always obtain a constant image. After the heating, some cooling step is required.

Next, a preservative to be contained in the cooling liquid,
For the fungicides and fungicides, "The Chemistry of Bactericidal and Fungicide" by Hiroshi Horiguchi (published by Sankyo Shuppan on January 10, 1982), "Encyclopedia of Bacterial and Fungicide" Committee of the Japanese Society of Bactericidal and Fungicide Various known compounds described in K.K. (Japan Society of Antimicrobial and Fungicide, issued on August 22, 1986) can be used. For example, phenol,
Cresol, o-phenylphenol, p-chloro-m
Phenolic compounds such as -xylenol, 2 ', 4', 5-trichloro-2-phenoxyphenol, benzisothiazolone, isothiazolone, 1,2-benzisothiazolin-3-one, 5-chloro-2-methyl-4-isothiazoline Thiazole and isothiazole compounds such as -3-one, 2- (thiocyanomethylthio) benzothiazole, 2-mercaptobenzothiazole, 3-allyloxy-1,2-benzisothiazole-1,1-oxide, 2,2 -Dibromo-2'-chloroacetophenone, 2,2-dibromoacetophenone, bis- (1,
4-dibromoacetoxy) -2-butene, bromomethylrhodanate, dibromonitrosopropionamide, 2-heptadecyl-1-ethylethanolimidazolium bromide, 2-bromo-4'-hydroxyacetophenone,
ω-bromo (or chloro) isonitroacetophenone,
Organic bromo compounds such as bromoacetic acid ethylthiophenyl ester and 2,2-zobrom-3-nitrilopropioamide; n-alkyldimethylbenzylammonium chloride; methyloxyethyldodecyloxyethylbenzylammonium chloride; Quaternary ammonium salt compounds, glycine compounds such as alkyl bis (aminoethyl) glycine, bis (alkylaminoethyl) glycine, guanidine compounds such as polyhexamethylene biguanidine, carboxylic acid esters such as dehydroacetic acid and benzoate; Its salt, hexadro-1,3,5-tris (2-hydroxyethyl) -S-
Triazine, hexahydro-1,3,5-triethyl-
Triazine compounds such as S-triazine, 2- (thiocyanomethylthio) benzimidazole, 4,5,6,7
-Imidazole compounds such as tetrachloro-2-trifluoromethylbenzimidazole and perpentazole;
Pyridine compounds such as 2,3,5,6-tetrachloro-4-methylsulfonylpyridine, amide compounds such as dithiobis (benzmethylamide), N, N-dimethyl-
N'-phenyl N '-(fluorodichloromethylthio)
-Sulfamide and the like. The above compounds can also be used as emulsified dispersions, alkali salts and organic amino salts to dissolve in water. Among them, phenol compounds, thiazole and isothiazole compounds, organic bromo compounds, and quaternary ammonium salt compounds are particularly preferable.

These preservatives, fungicides and fungicides can be used alone or in combination of two or more. Upon addition to the cooling water, it is preferable to dissolve in water and a suitable organic solvent in advance. These may be added prior to plate making, or may be added once or several times at desired times. Further, a preservative, an antifungal agent, and a microbicide are encapsulated with a bactericide. It is also effective to release the polymer by laminating or releasing the polymer from a support using a porous substance or a macromolecular compound having an active group bonded to a side chain, and to add the polymer to cooling water. The amount added to the cooling water varies depending on the bactericidal activity of the compound used or the fungi mixed in the cooling water and the amount thereof.
pm, more preferably 10-10000 ppm
When used in the range, image defects due to microorganisms can be prevented.

The cooling means using the cooling liquid containing the preservative, antifungal agent and bactericide has a structure in which the cooling liquid is sprayed on the printing plate or a structure in which the printing plate is immersed in the cooling liquid. . As a result, the heated printing original plate does not increase the etching temperature, and the printing original plate is not etched more than necessary. Therefore it is possible to manufacture the free printing plate causing deterioration in the quality of the printed matter.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below by taking an electrophotographic lithographic printing plate as an example. As described above, the exposed printing original plate is formed into a printing plate by a heating-cooling-etching process. If so, the printing original plate is not limited to the electrophotographic type.

Experimental Example 1 The surface of a JIS1050 aluminum sheet was grained with a rotating nylon brush using a Pumice-water suspension as an abrasive. The surface roughness (center line average roughness) at this time was 0.5 μm.
m. After washing with water, it was immersed in a 10% aqueous solution of caustic soda at 70 ° C., and was etched so that the amount of aluminum dissolved was 6 g / m ² . After washing with water, the sample was neutralized by immersion in a 30% aqueous nitric acid solution for 1 minute, and sufficiently washed with water. afterwards,
In a 0.7% nitric acid aqueous solution, using a rectangular alternating waveform having a voltage of 13 volts at the time of anode and 6 volts at the time of cathode (Japanese Patent Publication No.
-19191) electrolytic surface roughening for 20 seconds.
After immersing in a 50% solution of 0% sulfuric acid to wash the surface,
Washed with water. Further, the substrate was subjected to anodizing treatment in an aqueous 20% sulfuric acid solution so that the weight of the anodized film became 3.0% g / m ² , washed with water, and dried to prepare a substrate. Then ε
1.0 g of the same type phthalocyanine Liophon-ERPC (manufactured by Toyo Ink Co., Ltd.), copolymer of butyl methacrylate and methacrylic acid (methacrylic acid 30 mol%) 1
0.0 g, 60 g of tetrahydrofuran and 40 g of cyclohexanone were put in a 500 ml glass container together with glass beads, and the mixture was shaken with a paint shaker (Toyo Seiki Seisakusho Co., Ltd.)
To prepare a dispersion for a photoconductive layer.
This coating solution for a photoconductive layer was coated on the above substrate by bar coating and dried at 120 ° C. for 10 minutes to prepare a printing plate precursor for electrophotographic plate making having a dry film thickness of 4 μm. The above photosensitive material was charged to a surface potential of +300 V by a corona charger in a dark place, and then a negative image was exposed to tungsten light, and polymethyl methacrylate particles (particle size 0.3 μm) were placed in 100 ml of Isopar H (Esso Standard). 5 g was dispersed as toner particles, and a liquid developer prepared by adding 0.01 g of zirconium naphthenate as a charge control agent was used.
By applying a bias voltage of +200 V to the counter electrode, a clear positive toner image could be obtained. The printing original plate thus prepared is processed by a device provided with a fixing unit using a lamp heater and a cooling step of spraying cooling water onto the printing original plate as a pre-process of a PS plate developing machine Stublon 900N manufactured by Fuji Photo Film Co., Ltd. did. As cooling water, biohope (manufactured by KI Chemical Co., Ltd.), which is a thiazole preservative, was added to 100 ppm, and the water temperature was maintained at 25 ° C. In addition, Stublon 9
35 g of potassium silicate, 15 g of potassium hydroxide, and 10 g of monoethanolamine were added to a 690 ml of water in a 00N developing tank.
To prepare a printing plate for offset printing, dilute the gum solution GU-7 (manufactured by Fuji Photo Film Co., Ltd.) 1: 1 with water in the gum coater and apply it to the plate surface, and then dry by using the diluted etching solution and water for the washing layer. did. When the lithographic printing plate was prepared for one week by repeating the above operation, a high-quality image could be stably formed.

Comparative Example 1 A printing plate was prepared in the same manner as in Experimental Example 1 except that tap water was used as the cooling water. As a result, sludge-like precipitates were generated in the cooling portion, and spot-like spots were generated on the image after the etching, which was not practical.

Experimental Example 2 Fanside 910 containing a quaternary ammonium salt instead of the cooling water of Experimental Example 1 (Tokyo Fine Chemical Co., Ltd.)
A printing plate was prepared in exactly the same manner except for using a printing plate. When the lithographic printing plate was prepared for one week by repeating the above operation, a high-quality image could be stably formed.

Experimental Example 3 1.0 g of x-type phthalocyanine, vinyl acetate and crotonic acid copolymer (RESYN) were placed on the aluminum substrate of Experimental Example 1.
28-2930 Kanebo NS Co., Ltd.)
10.0 g, 60 g of detrahydrofuran, and 40 g of cyclohexanone were put together with glass beads in a 500 ml glass container, and dispersed with a paint shaker (manufactured by Toyo Seiki Seisaku-sho, Ltd.) for 60 minutes to prepare a dispersion for a photoconductive layer. . This coating solution for a photoconductive layer was coated on the above substrate using a bar coater and dried at 100 ° C. for 10 minutes to prepare a printing plate precursor for electrophotographic plate making having a dry film thickness of 4 μm. The printing original plate for electrophotographic plate making prepared in this way is 400 mm × 1100
and cut into a plate making machine. After charging the surface potential to +300 V by corona charging, an image portion was drawn by a semiconductor laser, and a printing plate was prepared by processes such as toner development, fixing, cooling, etching, washing with water, and gumming. The toner developing section was prepared by dispersing 6 g of polyvinyl acetate particles (particle size: 0.2 μm) as toner particles in 1000 ml of Isopar H (Esso Standard) and adding 0.01 g of zirconium naphthenate as a charge control agent. A liquid developer was charged, and a bias voltage of +200 V was applied to the counter electrode to perform reversal development. The plate surface temperature of the fixing unit was 100 ° C., and the cooling unit was maintained at 25 ° C. by adding an organic bromide-based preservative, Buiten CF (produced by K-I Kasei Co., Ltd.). In the etching part, an etching solution obtained by diluting the developing solution DP-4 for PS plate manufactured by Fuji Photo Film Co., Ltd. at 1:20, tap water in the washing part, and gum solution GU manufactured by Fuji Photo Film Co., Ltd. in the gum part. -7 was diluted 1: 1 with water and charged. When the lithographic printing plate was prepared for one week by repeating the above operation, a high-quality image could be stably formed.

Comparative Example 2 A printing plate was prepared in the same manner as in Experimental Example 3 except that tap water was used as the cooling water. The sludge-like precipitate was generated in the cooling part, and spot-like spots were generated on the image after etching, which was not practical.

Experimental Example 4 A printing plate was prepared in exactly the same manner except that Proxel GLX (manufactured by ICI Co., Ltd.), which is a benzothiazole preservative, was used instead of the cooling water of Experimental Example 1. When the lithographic printing plate was prepared for one week by repeating the above operation, a high-quality image could be stably formed.

Experimental Example 5 A printing plate was prepared in exactly the same manner as in Experimental Example 1, except that methylene bisisocyanate was used in place of the cooling water. When the lithographic printing plate was prepared for one week by repeating the above operation, a high-quality image could be stably formed.

Next, an electrophotographic plate making apparatus to which the present invention is applied will be described with reference to the drawings. FIG. 3 is a plan view showing the arrangement of the present invention. As shown in FIG. 3, the electrophotographic plate making apparatus 1 has a plate feeding unit 2, a drawing unit 3, a developing and fixing processing unit 4, a cooling unit 5, a dissolution processing unit 6, and a standby unit 7 along a transport direction indicated by an arrow A. , A puncher section 8 and a plate bending section 9 are provided.

The plate supply unit 2 is provided with a conveyor, and supplies the unexposed printing plate 10 with the photoconductive photosensitive layer facing upward to the drawing unit 3. As shown in FIG. 4, the drawing unit 3 is provided with a transfer table 11 on which the printing plate 10 is placed. The transfer table 11 can be moved in the transfer direction and the reverse direction. A charger 12 for positively charging the photoconductive photosensitive layer of the printing plate 10 is provided in an intermediate portion above the transport surface, and an exposure unit 13 is provided downstream thereof. The exposure unit 13 includes a semiconductor laser, and scans the charged photoconductive photosensitive layer with a laser beam to form an electrostatic latent image. Note that the drawing unit 3 is provided with a holding claw so that the exposed printing plate 10 is transferred to the developing and fixing processing unit 4 in the next stage.

As shown in FIG. 3, the developing / fixing processing section 4
4, a squeezing unit 15, a drying unit 16, and a fixing unit 17 are provided with a transport unit for transporting the printing plate 10. Developing unit 1
Reference numeral 4 applies a toner liquid to the printing plate 10 under a bias voltage, and reversely develops the electrostatic latent image to make it visible. The portion where the toner is attached becomes lipophilic. Excess toner liquid remaining on the developed printing plate 10 is air blown by the squeeze unit 15,
Further, in the drying unit 16, it is dried by warm air of a dryer and sent to the fixing unit 17. The fixing unit 17 includes a plurality of lamp heaters, and melts and fixes the toner particles attached to the printing plate 10 by radiant heating. The printing plate heated in the fixing unit 17 is cooled in the cooling unit 5 to a temperature that does not hinder the next etching process. As the cooling liquid, cooling water to which at least one selected from phenolic compounds, thiazole and isothiazole compounds, organic bromide compounds, and quaternary ammonium salt compounds is added, is sprayed on the plate 10 or the plate 10 Is cooled by immersion in the cooling water.

The elution processing section 6 includes an etching section 18 for immersing the printing plate 10 in an alkaline solution to elute a non-image portion of the photoconductive photosensitive layer, and a squeezing section 19 for removing excess alkali liquid attached to the printing plate 10. A washing unit 20 for washing with water to remove an alkaline solution, a gum solution applying unit 21 for applying a gum solution to the washed plate 10, and a drying unit 22 for drying the applied gum solution, and are fed by a transport roller. The above processing is performed on the printing plate 10 to form a plate surface. The printing plate 10 having been subjected to the above-described processing is conveyed to the standby unit 7 and stands by. The notch for positioning at the time of plate hanging is punched by the next puncher unit 8, and further, the printing plate 10 is bent by the plate bending unit 9 in the longitudinal direction. A printing plate is formed by bending both ends by a predetermined size.

FIGS. 1 and 2 show the structure of one embodiment of the cooling section 5 in the above plate making apparatus. FIG. 1 is a perspective view showing a schematic structure thereof, and FIG. 2 is a side sectional view thereof. As shown in FIGS. 1 and 2, a tray 23 is disposed below the cooling unit 5, and above the tray 23, a fixing unit 17 is disposed.
Guides the printing plate 10 conveyed from the direction 3 in the direction of arrow A in FIG.
A number of spray beds 24 are provided. Each of these spray beds 24 has an L-shaped cross section having a vertical wall portion 24A on the upstream side in the transport direction of the printing plate 10, and is separated from each other at a predetermined interval in a direction perpendicular to the transport direction of the printing plate 10. They are arranged in parallel. An optical sensor 25 is provided above the cooling unit 5 on the upstream side, detects whether the printing plate 10 has been carried into the cooling unit 5 from the fixing unit 17, and outputs a detection signal to the control unit 26 (FIG. 2).

Further, from the bottom of the receiving tray 23, a water supply pipe 28 as a cooling means is provided upright. The water supply pipe 28 is bifurcated in the vicinity of the bottom of the tray 23, one of which is further branched into three, and the tips 28 A of the respective branches are arranged along the lower portions of the three spray beds 24. ing. The other end of the water supply pipe 28 is
The upper part of the three spray beds 24 is branched into two, and the tip 28B of each branch part is arranged along the gap between the three spray beds 24. As shown in FIG. 2, circular through holes 30 are formed at predetermined intervals along the axial direction (perpendicular to the paper surface of FIG. 2) on the upper surface of the distal end portion 28 </ b> A of the water supply pipe 28. 24B
A circular through hole 32 is formed coaxially with the through hole 30. On the other hand, circular through holes 34 are formed at predetermined intervals along the axial direction (perpendicular to the plane of the drawing) at the lower portion of the distal end portion 28B of the water supply pipe 28 to serve as a spray nozzle. A cock 36 is provided on the upstream side of the distal end portion 28B of the water supply pipe 28.
The supply of the cooling water to the distal end portion 28B can be stopped. A squeeze roller 38 is provided downstream of the cooling unit 5.
Is provided, and the printing plate 10 passes between the squeeze rollers 38.

The water supply pipe 28 penetrates through the bottom of the tray 23, extends downward, and reaches a cooling water tank 40. The cooling water tank 40 is filled with the cooling water 42 of the present invention, and the cooling water 42 is pumped into the water supply pipe 28 by the pump 44. On the other hand, the upper end of the collecting pipe 46 is connected to the bottom of the tray 23, and the lower end of the collecting pipe 46 reaches the cooling water tank 40.
It can be collected inside. The recovery pipe 46
A filter 48 is interposed in an intermediate portion of the cooling water 42 to remove foreign matter in the collected cooling water 42.

In the cooling water tank 40, a temperature sensor 52 for detecting the temperature of the cooling water 42 is provided.
The temperature sensor 52 is connected to the control device 26.
Further, the cooling water tank 40 is connected to a cooler 50, and the cooler 50 is controlled by the control device 26. With such a configuration, when the temperature T1 of the cooling water 42 in the cooling water tank 40 becomes equal to or higher than the predetermined temperature T0, the control device 26 operates the cooler 50 based on the output signal of the temperature sensor 52, The temperature T1 of the cooling water 42 in the cooling water tank 40 is set lower than the predetermined temperature T0.

In this embodiment, the cooling water in the cooling water tank is sprayed onto the printing plate from the through-hole at the tip of the water supply pipe. Instead, the cooling water controlled to a predetermined temperature is used. An immersion method in which the printing plate passes through the filled cooling tank may be used.

[0032]

As described above, the heat-fixed printing plate precursor is prepared by adding at least one of a preservative, a fungicide, and a bactericide,
Cooling with cooling water containing at least one selected from phenolic compounds, thiazole and isothiazole compounds, organic bromide compounds, and quaternary ammonium salt compounds causes image defects even after long-term use. Not only was it possible to consistently provide high image quality.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of a cooling means in the present invention.

FIG. 2 is a side sectional view of FIG.

FIG. 3 is a plan view showing an arrangement of an embodiment of the plate making apparatus of the present invention.

FIG. 4 is a side sectional view showing a schematic structure of a drawing unit in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrophotographic plate-making apparatus 2 Plate feeding part 3 Drawing part 4 Developing and fixing part 5 Cooling part 6 Elution processing part 7 Standby part 8 Puncher part 9 Plate bending part 10 Printing plate 11 Transport stand 12 Charger 13 Exposure part 14 Development part 15 Squeeze part 16 Drying part 17 Fixing part 18 Etching part 19 Squeeze part 20 Rinse part 21 Gum liquid application part 22 Drying part 23 Receiving tray 24 Spray bed 24A Vertical wall part 24B Top wall part 25 Optical sensor 26 Control device 28 Water supply pipe 28A, 28B Tip 30, 32, 34 Through hole 36 Cock 38 Squeeze roller 40 Cooling water tank 42 Cooling water 44 Pump 46 Recovery pipe 48 Filter 50 Cooler 52 Temperature sensor

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G03F 7/38 G03F 7/00 503 G03F 7/30 G03G 13/28

Claims (8)

(57) [Claims] 1. A first method for heating a printing plate precursor to which an image has been exposed .
And a second step of cooling the heated printing original plate
And removing the photosensitive layer other than the image on the cooled printing original plate
A lithographic printing plate manufacturing method including the third step of:
And provided between the first step and the third step.
Further, the second step comprises the step of reducing the amount of a preservative, a fungicide and a bactericide.
The printing original plate is cooled by a cooling liquid containing at least one kind.
A method for producing a lithographic printing plate. 2. The preservative, the fungicide and the bactericide contained in the cooling liquid are selected from phenolic compounds, thiazole and isothiazole compounds, organic bromo compounds and quaternary ammonium salt compounds. 2. The method for producing a lithographic printing plate according to claim 1, wherein the method comprises at least one. 3. The method according to claim 1, wherein the image forming of the printing original plate is performed by an electrophotographic method. 4. The method for producing a lithographic printing plate according to claim 1, wherein the image forming of the printing original plate is performed by a photopolymerization type image forming method. 5. The method for producing a lithographic printing plate according to claim 1, wherein the image forming of the printing original plate is performed by a silver sensor polymerization type image forming method. 6. A first method for heating a printing plate precursor to which an image has been exposed .
And a second step of cooling the heated printing original plate
And removing the photosensitive layer other than the image on the cooled printing original plate
In a lithographic printing plate manufacturing apparatus including a third step to be provided between the first step and the third step
A lithographic printing plate manufacturing apparatus, wherein a cooling means for cooling the printing original plate with a cooling liquid containing at least one of a preservative, a fungicide and a bactericide is provided in the second step . 7. The printing apparatus according to claim 6, wherein the cooling unit sprays the cooling liquid onto the printing plate.
A lithographic printing plate manufacturing apparatus according to Claim 1. 8. The cooling device according to claim 6, wherein the cooling means is configured to immerse the printing original plate in the cooling liquid.
A lithographic printing plate manufacturing apparatus according to Claim 1.