JPH0854728A - Plate making device for planographic printing plate - Google Patents

Abstract

PURPOSE:To provide a plate making device for a planographic printing plate which is equipped with a cleaning device to prevent contamination of a planographic printing plate at high accuracy after the cleaning process. CONSTITUTION:The plate making device is equipped with a cleaning device 31 having the following constitution. The carrying route of the planographic printing plate 1 is equipped with a brush roller 13 which slides on the planographic printing plate 1 and rotates in the opposite direction to the carrying direction. A black part after exposure and development in a silver photosensitive layer formed on the planographic printing plate 1 is scraped off by the brush roller 13. Chips of the black part scraped are stopped together with a cleaning liquid supplied from a cleaning liquid supply means 17 and then discharged together.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate making apparatus for making a lithographic printing plate, and more particularly to a photosensitive lithographic printing plate having a gelatin silver halide photosensitive emulsion layer provided on a non-silver photosensitive layer. To a plate making apparatus for obtaining

[0002]

2. Description of the Related Art As a photosensitive lithographic printing plate, a support having a hydrophilic surface has a non-silver photosensitive layer capable of forming a water-insoluble lipophilic image, and a gelatin silver halide photosensitive layer thereon. There are complex types. A plate-making method using this photosensitive lithographic printing plate is described in JP-A-56-2573.
No. 9 publication. In this photosensitive lithographic printing plate, the gelatin silver halide photosensitive layer has sensitivity to light having a wavelength different from that of the non-silver photosensitive layer, and has a function of masking the underlying non-silver photosensitive layer in an image form.

The structure of the photosensitive lithographic printing plate 1 will be described below with reference to FIG. 3 (a). The support 2 is made of aluminum in the form of a plate having a thickness of 0.1 mm or more. Further, a non-silver photosensitive layer 3 and a gelatin silver halide photosensitive emulsion layer 4 are formed in a laminated state. Next, FIG.
Explaining the plate making process of the planographic printing plate with reference to (g),
As shown in FIG. 2B, the silver halide silver halide emulsion layer 4 is exposed from above with a laser beam 5 or the like, and then immersed in a photographic developer. As a result, the exposure position is blackened as shown in (c), and when it is dipped in the fixing solution in this state, silver halide other than the blackened portion 6 is removed as shown in (d). That is, except for the blackened portions 6, the silver halide silver halide emulsion layer 4 becomes transparent.

Next, as shown in (e), when the entire surface of the photosensitive lithographic printing plate 1 is exposed to ultraviolet light 7, the non-silver photosensitive layer 3 except the lower part of the blackened portion 6 is exposed. In the following description, the exposed photosensitive lithographic printing plate is simply referred to as a lithographic printing plate. Next, the process proceeds to the step of removing the gelatin silver halide photosensitive emulsion layer 4 including the blackened portion 6.
This removal process is also called wash-off, and is conventionally performed as shown in FIG.
The cleaning device 11 as shown in FIG. That is, the carrying roller 12 is for carrying the planographic printing plate 1 at the stage shown in FIG. 3E in the direction of arrow A, and the brush roller 13 is provided in the middle thereof. The brush roller 13 is configured to rotate in the arrow B direction, that is, in the direction in which the planographic printing plate 1 is conveyed. A water storage tank 14 containing a cleaning liquid (for example, warm water) is provided below the transportation path of the planographic printing plate 1, and the water storage tank 14 is provided with a heater 15 for heating the cleaning liquid to, for example, about 45 ° C. . The hot water in the water storage tank 14 is sucked up by the pump P1, filtered by the filter 16, and then jetted from the jet nozzle 17 to the entire surface of the planographic printing plate 1. The pump P2 is for supplying the cleaning liquid into the water storage tank 14.

In the cleaning device 11 having the above construction, the brush roller 1 is carried while the planographic printing plate 1 is carried by the carrying roller.
When 3 is rotated, the gelatin silver halide photosensitive emulsion layer 4 containing the blackened portion 6 is scraped off. Then, the scraped blackened portion 6 becomes a small piece, which is made to flow into the water storage tank 14 by the hot water jetted from the jet nozzle 17. As a result, in the planographic printing plate 1, as shown in FIG.
The entire surface of is exposed. This lithographic printing plate 1 is conveyed to the next developing step, the non-silver photosensitive layer 3 in the portion exposed by the ultraviolet light 7 is removed, and the lithographic printing plate 2 shown in FIG.
1 is completed. However, the conventional cleaning device 11 has the following problems.

[0006]

The blackened portion 6 scraped off by the brush roller 13, that is, the exposed / developed gelatin silver halide photosensitive emulsion layer 4 is not immediately dissolved but is in a gel state for a while. Or, it will float on the surface of the planographic printing plate 1 in a granular state. The scraped blackened portion 6 contains blackened silver particles, which adhere to the transport roller 12 while drifting in the liquid, and as shown in FIG. 3 (f), the planographic printing plate. Transferred to the surface of No. 1 to form black spot stains 18. If such a spot stain 18 remains attached and the process proceeds to the next developing step, the next developing step is carried out with a highly alkaline solution, but the spot stain 18 cannot be dissolved and remains on the plate surface as it is and becomes black during printing. Spot stains occur.

Further, since the gelatinous silver halide grains remain on the plate surface, the elution of the non-silver photosensitive layer 3 is hindered, and when the part is a non-image part, the elution is poor (not developed). As a result, spot stains, that is, print stains are generated during printing, and high-quality printed matter cannot be obtained. An object of the present invention is to provide a plate making apparatus for a lithographic printing plate which can be surely washed after the washing process so that silver particles do not adhere to the plate surface and can obtain a good quality printed matter.

[0008]

The above object of the present invention can be achieved by the following constitution. (1) A non-silver photosensitive layer capable of forming a water-insoluble hydrophilic image is provided on a support having a hydrophilic surface and a thickness of 0.1 mm or more, and gelatin is formed on the non-silver photosensitive layer. A silver sensitized silver halide photosensitive layer provided with a gelatin silver halide sensitized layer containing silver halide and silver halide, and the developed silver sensitized layer from the non-silver sensitized layer exposed through the exposed and developed silver sensitized layer A plate making apparatus having a cleaning device for removing a cleaning liquid, comprising a cleaning liquid supply means for supplying a cleaning liquid to the photosensitive surface of the printing plate, wherein the cleaning device is arranged on the downstream side of the cleaning liquid supply means. A plate making apparatus having a brush roller that is in sliding contact with the photosensitive surface of the printing plate and rotates in a direction opposite to the conveying direction of the printing plate to dam the cleaning liquid.

(2) The plate making apparatus according to (1), wherein the cleaning device has a free roller on the upstream side of the brush roller that restricts upward movement of the printing plate. (3) The plate making apparatus according to (1), wherein the cleaning device has a bar on the upstream side of the brush roller that restricts upward movement of the printing plate. (4) The plate making apparatus according to (1) or (2), wherein the cleaning device further includes a cleaning liquid supply unit that supplies a cleaning liquid to the plate surface of the printing plate on the downstream side of the brush roller.

[0010]

According to the present invention, the brush roller rotates in the direction opposite to the printing plate conveying direction to contact the printing plate to remove the silver photosensitive layer while dampening the cleaning liquid, so that the dirty cleaning containing silver particles is performed. Water does not flow downstream from the brush roller. The brush roller is preferably densely brushed,
Thereby, the contact portion with the printing plate can be made watertight. Further, by rotating the brush roller at a high speed, a force in the direction opposite to the conveying direction is applied to the cleaning liquid on the printing plate, so that the cleaning liquid is less likely to flow downstream. The cleaning liquid containing silver particles does not flow downstream from the brush roller, and since the silver photosensitive layer is removed from the printing plate by contact with the brush, silver particles reach the printing plate downstream from the brush roller. It does not adhere. However, in order to increase the reliability, it is preferable to wash the printing plate with the washing liquid even on the downstream side of the brush roller.

The processing of the photosensitive lithographic printing plate used in the present invention will be described below. The photosensitive lithographic printing plate used in the present invention is one in which a gelatin silver halide photosensitive emulsion layer is directly provided on a non-silver photosensitive layer as described above, in which a substantially water-insoluble The lipophilic resin is dispersed and contained in the form of fine particles. Here, the lipophilic resin is a sample in which a predetermined resin is applied to a certain support by 2 μm or more, and the contact angle θ of the resin surface of the sample is measured. Printed magazine No. 25, October issue (1968) Mitsuo Obana "Weting phenomenon in lithographic printing" suggests that the sample is immersed in water at 24 ° C by the captive bubble method, and fine particles (foam) of kerosene on the surface. Contact the contact angle of kerosene in water with a goniometer θ _{o / w} , contact the sample with kerosene and bring fine particles of water (bubbles) into contact with the surface, and contact angle θ of water in kerosene in the same manner. Measure _{w / o} and θ =-[θ _{o / w} −θ _{w / o} ]
Say what is almost positive. Such a substantially water-insoluble lipophilic resin is the one mentioned as the resin of the binder used in the non-silver photosensitive layer, for example, shellac, polyamide resin, phenol resin, polyvinyl acetal resin, linear polyurethane. In addition to resins, novolac type phenol resins, polyester resins, polyvinyl cinnamate resins and photosensitive polymers such as photosensitive unsaturated polyesters are included.

These lipophilic resins are preferably dispersed in a gelatin silver halide photosensitive emulsion with a grain size of 0.01 μm to 10 μm. The amount thereof may be about 0.1 part by weight to about 20 parts by weight based on 10 parts by weight of the hydrophilic colloid in the gelatin silver halide photosensitive emulsion. It is preferably 1 to 10 parts by weight, and most preferably 2 to 5 parts by weight, relative to 10 parts by weight of the hydrophilic colloid. The gelatin silver halide emulsion may be a negative type ordinary emulsion or a direct positive type emulsion. As the silver halide, commonly used silver chloride, silver bromide, silver iodide or a mixed silver halide thereof can be used. The average particle diameter is preferably about 0.01 μm to 5 μm. The particles have, for example, sulfur sensitization, reduction sensitization, Ir, R
Chemical sensitization such as sensitization with salts of precious metals such as h and Pt,
Spectral sensitization with a sensitizing dye can be performed. Any particle having a latent image distribution of surface latent image type or internal latent image type may be used. Additives usually used can be added to this. When the photosensitive silver halide emulsion layer containing the lipophilic resin dispersed therein is used as described above, strong adhesion with the lower non-silver photosensitive layer is achieved. Even when a photosensitive silver halide emulsion containing such a lipophilic resin is directly coated on the non-silver photosensitive layer and dried, troubles due to peeling of the silver halide photosensitive layer which may occur in the drying step are caused. Can be avoided.

These gelatin silver halide photosensitive emulsion layers
Is about 1 g / m²To 10 g / m ², Preferably 2g
/ M²To 6 g / m²Can be applied in a dry amount of
It Use dip, air knife, curtain, etc.
Cloth method, for example, US Pat. No. 2,681,294
Hopper coating method and extrusion coating method
Can be applied. Also, on the non-silver photosensitive layer, a special composition
An intermediate layer is provided and a gelatin silver halide photosensitive emulsion is formed on the intermediate layer.
It is also possible to provide a photosensitive layer containing. As above
Method and process for making a lithographic printing plate using a photosensitive lithographic printing plate
The reason is as follows. Image exposure first, gelatin halogen
Form a latent image on the silver halide in the silver halide emulsion layer.
It Next, development of silver halide (first development) is performed, and development is performed.
After processing either with stop solution or fixer
The non-silver photosensitive layer is exposed to active light and then gelatinized.
A washout process to remove the silver halide emulsion layer
Then the exposed or unexposed areas of the non-silver photosensitive layer.
Exposing the hydrophilic surface of the support by dissolving and removing only one side
Then, a second development process for obtaining a lithographic printing plate is performed. This place
In the case of the second development, the processing liquid used for the second development is the exposed portion of the non-silver photosensitive layer.
Or a treatment that selectively dissolves only one of the unexposed areas
A liquid is required, and it is especially used in the development of PS plates.
You can choose from image solutions or similar developers
It For example, is the non-silver photosensitive layer an o-quinonediazide compound?
If the layer consists of
It is described in Japanese Patent No. 4,141,733.
Such a developer is used.

For the development of the gelatin silver halide emulsion light-sensitive layer, the development method usually used for silver halide light-sensitive materials is used. The developing agent includes hydroquinone, catechol, resorcin, pyrogallol, a halogen atom, an aryl group, an amino group, a C _{1 to} C ₆ alkyl group,
The above compound substituted with an alkoxy group or the like is used. The developing solution further includes an alkali agent such as sodium hydroxide, potassium hydroxide and triethanolamine, a pH buffering agent such as sodium carbonate, potassium carbonate and potassium silicate, and sodium triphosphate, potassium bromide, a mercapto compound and triazole. An antifoggant such as a class of compounds, a water softener such as EDTA or sodium polyphosphate, a preservative such as sodium sulfite, or ethanolamine can be used. The processing conditions with such a developing solution are generally a liquid temperature of 20 ° C. to 50 ° C., more preferably 24 ° C. to 40 ° C. for 10 seconds to 120 seconds, and more preferably 10 seconds to 40 seconds.
Seconds. The fixing solution contains a silver halide solvent such as sodium thiosulfate, sodium sulfite, ammonium rhodanate or ammonium thiosulfate, and a pH buffering agent, and a fixing solution which is usually used for silver halide light-sensitive materials is used. The fixing process is carried out at room temperature for 1 to 30 seconds, preferably 10 seconds or less.

In the present invention, it is preferable that the gelatin silver halide light-sensitive emulsion layer is washed out in the presence of a protease. Here, "in the presence" means a mode in which the protease is present in the emulsion layer at the time of washing-out treatment, and the protease is dissolved in an aqueous solution which is a treatment liquid for washing-out. Both of the aspects to be kept are included. As a more specific example of the former embodiment, a proteolytic enzyme inactivated with respect to gelatin is contained in advance in the gelatin silver halide light-sensitive emulsion layer (for example, low pH with sulfuric acid (for example, 4 or less). ) A method in which a protease treated with a solution is contained in a gelatin silver halide light-sensitive emulsion layer kept at a low pH), and the protease is dissolved in the fixing solution to fix the gelatin. A mode in which a protease is contained in the silver halide light-sensitive emulsion layer is included.
Further, as a modification of the latter embodiment, it is possible to perform the washing-out treatment by dividing it into two baths, in which the proteolytic enzyme is contained in the first bath, the second bath, or both of them.
Among these, the mode in which the proteolytic enzyme is contained in the processing solution for washing out is preferable, and the mode in which the proteolytic enzyme is dissolved in the fixing solution is most preferable.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a planographic printing plate making apparatus to which the present invention is applied will be described below with reference to FIG. FIG.
FIG. 3 is a schematic configuration diagram of a cleaning device that constitutes a plate making device, and members that perform the same operations as those of the conventional cleaning device are designated by the same reference numerals and description thereof is omitted. Cleaning device 31 in this embodiment
2 is configured so that the rotation direction C of the brush roller 13 is opposite to the rotation direction C, that is, the direction in which the exposed lithographic printing plate 1 conveyed in the direction of arrow A is pushed back to the upstream side. A free roller 32 for restricting upward movement of the planographic printing plate 1 is provided upstream of the brush roller 13.
Is provided. Further, the injection nozzle 17 is provided not only on the upstream side of the brush roller 13 but also on the downstream side.

The diameter of the brush roller 13 is set to about 100 mm, and the rotation speed is set to about 100 to 500 rpm. Further, the transportation speed of the planographic printing plate 1 is 600
Although it is set to mm / min, not only the diameter but also the rotation speed and the conveyance speed are not limited to the above. The functions of the water storage layer 14, the heater 15, the pumps P1 and P2, and the filter 16 are the same as those of the conventional example described above.
7, hot water heated to about 45 ° C. is jetted onto the surface of the planographic printing plate 1 being conveyed. Then, in the cleaning device 31, the planographic printing plate 1 described with reference to FIG. 3 (e), that is, the blackened portion 6 formed by photographic development, is further exposed to ultraviolet light 7 (hereinafter, simply referred to as planographic printing plate). A printing plate) is delivered.

Next, the operation of the cleaning device 31 will be described.
The blackened portion 6 is scraped off by rotating the brush roller 13. The photosensitive layer in the non-blackened portion is also scraped off. At this time, the hot water jetted from the upstream side of the brush roller 13 and flowing along the surface of the planographic printing plate 1 is stopped by the rotation of the brush roller 13 so to speak. Then, the scraped off small pieces of the blackened portion 6 are also mixed in the dammed warm water and are not flowed downstream from the brush roller 13 as the lithographic printing plate 1 moves. Thus, since the hot water is vigorously jetted from the jet nozzle 17 while the hot water containing the small pieces of the blackened portion 6 is dammed, the small pieces of the blackened portion 6 are provided in the lower portion of the transport path. It flows into the water tank 14. Therefore, the small pieces of the blackened portion 6 do not adhere to the planographic printing plate 1,
Even if it adheres, it will be washed away by the hot water sprayed from the spray nozzle 17 provided between the transport roller 12 on the downstream side.

Here, comparing with the conventional cleaning device 11,
In the conventional cleaning device 11, the scraped small pieces of the blackened portion 6 are blown toward the conveying roller 12 on the downstream side by the rotation of the brush roller 13. Then, the small pieces that could not be flushed were pressed against the surface of the lithographic printing plate 1 by the transport roller 12, and it became more difficult to flow. However, in the cleaning device 31 in this embodiment, the scraped blackened portion 6 is not blown to the downstream side, and the brush roller 13 does not have a function of pressing the scraped small piece. It will be washed away in the tank 13. Further, even if a small piece of the blackened portion 6 is attached and conveyed to the downstream side, it is not pressed, and the injection nozzle 17 provided on the downstream side of the brush roller 13
It is easily washed away by the hot water sprayed from. Therefore, in the cleaning device 31 of the present embodiment, the spot stains are not formed, and the lithographic printing plate 1 can be developed to obtain a lithographic printing plate 21 free from stains, and beautiful printing is performed. be able to.

A support plate 33 is provided below the position where the brush roller 13 is disposed, and is configured to support the planographic printing plate 1 from the back side. Therefore, when the brush roller 13 is pressed against the planographic printing plate 1, the pressure contact force is not reduced by bending downward, and scraping can be efficiently performed. Brush roller 1 that rotates when the end of lithographic printing plate 1 faces upward and is curled or bent
However, since the trailing portion is restricted from being raised by the free roller 32, the planographic printing plate 1 returns to an appropriate transport position due to the transport force and its own rigidity. Therefore, the blackened portion 6 can be scraped off smoothly and accurately from the planographic printing plate 1.

Next, a second embodiment of the present invention will be described with reference to FIG. The main difference between this embodiment and the first embodiment is that the brush rollers 13a, 13 having different rotation directions are used.
Two sets b are provided along the transport direction of the planographic printing plate 1. That is, the cleaning device 31 is provided with two sets of brush rollers 13a and 13b and a support plate 33 as shown in FIG. In this configuration, the first brush roller 1
Since 3a is rotating in the direction of arrow B as in the conventional example, the scraped small pieces of the blackened portion 6 are blown toward the brush roller 13b on the downstream side. However, since the jet nozzle 17 is provided between the brush rollers 13a and 13b and the brush roller 13b on the downstream side is rotating in the direction of arrow C, it is scraped off by the blown small pieces and the brush roller 13b on the downstream side. The small piece of blackened part 6
Similarly to the above, the water is blocked before the brush roller 13b on the downstream side and is washed away by the hot water jetted from the jet nozzle 17 disposed in the middle.

In the cleaning device 31 shown in this embodiment, the blackened portion 6 can be scraped off more reliably, and the brush roller 13a on the upstream side conveys the planographic printing plate 1 in the direction in which it is conveyed. It is possible to speed up the scraping work in combination with the fact that it is rotating. In addition, the free roller 32
Since the support plate 33 and the support plate 33 operate in the same manner as described above, the planographic printing plate 1
The scraping work can be performed reliably regardless of the size of the. Then, a lithographic printing plate without spot stains can be obtained in the same manner as described above, and beautiful printing can be performed. The free roller 32 may be replaced with a bar. Further, the brush roller 13 on the downstream side in the second embodiment.
An injection nozzle may be added between b and the conveyance roller 12 so that the dirt can be removed more reliably. Further, the cleaning device 31 is not limited to cleaning the lithographic printing plate and can be widely used in the step of removing the film.

[0023]

As described above, in the planographic printing plate making apparatus according to the present invention, the planographic printing plate conveying path is in sliding contact with the planographic printing plate and rotates in a direction opposite to the conveying direction. A brush roller is provided, and the developed silver photosensitive layer formed on the planographic printing plate is scraped off by the brush roller, and the scraped silver photosensitive layer pieces are dammed and washed away together with the cleaning liquid supplied from the cleaning liquid supply means. Configured. Therefore, the scraped pieces of the silver photosensitive layer do not adhere to the lithographic printing plate and are not transported, and spot stains on the lithographic printing plate, which are print stains during printing, can be completely prevented. Since the lithographic printing plate is washed reliably and accurately,
The quality of the planographic printing plate and the cleaning efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a configuration of a cleaning apparatus that is a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a configuration of a cleaning apparatus that is a second embodiment of the present invention.

3A is a sectional view of a photosensitive lithographic printing plate, FIG. 3B is a sectional view showing exposure of the photosensitive lithographic printing plate, FIG. 3C is a sectional view showing a development step of a silver photosensitive layer, and FIG. ) Is a cross-sectional view showing the fixing step, (e) is a cross-sectional view showing exposure by ultraviolet light, (f)
FIG. 4G is a cross-sectional view showing a form after cleaning and before development, and FIG. 6G is a cross-sectional view showing a form after cleaning and after development.

FIG. 4 is a schematic configuration diagram showing an example of a conventional cleaning device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photosensitive lithographic printing plate 2 Support 3 Non-silver photosensitive layer 4 Gelatin silver halide photosensitive emulsion layer 5 Laser light 6 Blackening part 6a Image forming part 7 Ultraviolet light 11, 31 Cleaning device 12 Conveying rollers 13, 13a, 13b Brush Roller 14 Water tank 15 Heater 16 Filter 17 Injection nozzle 18 Spot dirt 32 Free roller 33 Support plate

Claims (4)

[Claims] 1. A non-silver photosensitive layer capable of forming a water-insoluble hydrophilic image is provided on a support having a hydrophilic surface and a thickness of 0.1 mm or more, and on the non-silver photosensitive layer. The developed silver from the non-silver photosensitive layer exposed through the exposed and developed silver photosensitive layer of the photosensitive lithographic printing plate having a gelatin silver halide photosensitive layer containing gelatin and silver halide on A plate making apparatus comprising a cleaning device for removing a photosensitive layer, comprising a cleaning liquid supply means for supplying a cleaning liquid to the photosensitive surface of the printing plate, wherein the cleaning device is arranged on the downstream side of the cleaning liquid supply means, A plate making apparatus having a brush roller which is in sliding contact with the photosensitive surface of the printing plate and rotates in a direction opposite to the conveying direction of the printing plate to dam the cleaning liquid. 2. The plate making apparatus according to claim 1, wherein the cleaning device has a free roller on the upstream side of the brush roller that restricts the upward movement of the printing plate. 3. The plate making apparatus according to claim 1, wherein the cleaning device has a bar on the upstream side of the brush roller that restricts upward movement of the printing plate. 4. The plate making apparatus according to claim 1, wherein the cleaning device has a cleaning liquid supply unit that further supplies a cleaning liquid to the plate surface of the printing plate on the downstream side of the brush roller.