JPH1090912A - Processing method and processing device of photosensitive lithographic plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the phenomenon of ball-point pen remaining which is caused in processing by setting the carrying speed of a processing device to a specified value or more, and setting the humidity of a processing part and a water washing part to a specified value or more. SOLUTION: The carrying speed in a processing device is set to 2000mm/min or more, and the humidity of a processing part 3 and a water washing part 4 is set to 80% or more. A processing is performed by use of this processing device. In a PS plate processing device, for example, the insertion of a PS plate 10 is detected by a plate detecting means 2, and the operation of the PS plate processing device is started, whereby the plate is fed into the processing part 3 and processed with a developer. It is then carried to the water washing part 4 for treatment, carried to a gum processing part 5 for application of a gum solution, further carried to a drying part 6 or drying, and then used as the PS plate 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing method and a developing apparatus for imagewise dissolving a photosensitive layer of a photosensitive lithographic printing plate subjected to image exposure.

[0002]

2. Description of the Related Art Conventionally, as a method of producing a lithographic printing plate using a photosensitive lithographic printing plate, a method of treating a large number of image-exposed photosensitive lithographic printing plates with an alkaline developing solution which is recycled and reused is known. Practical. The photosensitive lithographic printing plate is generally subjected to a developing process by applying a developing solution while being conveyed after the exposure, followed by washing, rinsing (gumming), and drying. In this processing method, a phenomenon that a ballpoint pen remains on the developed lithographic printing plate may occur. This is thought to be caused by the ink of the ballpoint pen drawn on the photosensitive layer being re-adhered to the grain surface of the support after the photosensitive layer material was removed by the developing solution, Conventionally, they have been achieved by examining the improvement of the grain of the support so as not to generate the ballpoint pen residue. However, it has been clarified that although the improvement of the grain improves the ballpoint pen residue, it adversely affects other performances.

[0003] In order to solve the above problem, there has been proposed a developing apparatus in which the transport speed is increased, and by increasing the transport speed of the photosensitive lithographic printing plate remarkably, the ink of a ball-point pen is applied to the surface of the grain of the support. To prevent redeposition. However, although the above problem can be solved to a certain extent by increasing the transport speed, depending on various transport conditions in several steps from the development processing section to the drying section, it is possible to sufficiently suppress the remaining ballpoint pen. At present, the effect of has not been obtained.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method for developing a photosensitive lithographic printing plate in which the phenomenon of a ball-point pen remaining in the developing process is improved. To provide a developing method. Another object of the present invention is to provide a processing apparatus applicable to the method.

[0005]

The above object of the present invention has been attained by the following constitutions.

(1) A photosensitive lithographic printing plate developing apparatus, wherein the transport speed is 2000 mm / min or more, and the humidity of each of the developing section and the rinsing section is 80% or more.

(2) A method for developing a photosensitive lithographic printing plate, wherein the developing process is performed using the above-described developing apparatus.

In other words, the present inventors have solved the problem of the ball-point pen remaining which has not been sufficiently improved even when the transport speed of the photosensitive lithographic printing plate has been increased, particularly the evaporation of the processing solution in the developing processing section and the washing processing section. It has been found that drying caused by the above, that is, the low humidity state is suppressed as much as possible, and the present invention can be solved by setting the part to a specific humidity condition (maintaining a high humidity), thereby leading to the present invention. .

Hereinafter, the present invention will be described in detail.

The photosensitive lithographic printing plate of the present invention (hereinafter referred to as PS)
Plate), the transport speed is 2000 mm / min or more, and the humidity of the developing unit and the
% Or more, and the method of developing a PS plate of the present invention performs the developing process using the developing apparatus.

[1] Development Processing Apparatus (Automatic Developing Machine) and Development Processing Method Hereinafter, a photosensitive lithographic printing plate processing method and processing apparatus according to an embodiment of the present invention will be described with reference to the drawings. Is not limited to the present embodiment. FIG. 1 is a sectional view showing the structure of a PS plate processing apparatus according to the present invention, FIG. 2 is a sectional view showing the front structure of a developing unit shown in FIG. 1, and FIG. 4 is an enlarged configuration sectional view (a) and a side configuration sectional view (b) of the blocking member of the development processing unit in FIG. 1, and FIG. 5 is a configuration sectional view showing another example of the PS plate processing apparatus of the present invention.

In the PS plate processing apparatus of FIG. 1, when the PS plate 10 subjected to image exposure is inserted from the insertion table 1, the insertion of the PS plate is detected by the plate detecting means 2, and the operation of the PS plate processing apparatus is started. As a result, the developer is sent to the development processing unit 3 and developed by the developer. PS plate transport speed is 2
000 mm / min or more. Next, it is conveyed to the water washing section 4 where it is processed, further conveyed to the gum processing section 5 where the gum solution is applied, and further conveyed to the drying section 6 where it is dried and subjected to P treatment.
It will be used as the S version. This is disclosed in
This is the same as the case of the PS plate processing apparatus described in JP-A-236041 and JP-A-3-59666.

If the transport speed of the PS plate is lower than 2,000 mm / min, the time during which the ballpoint pen ink eluted in the developer stays on the grain surface of the support becomes longer, and contains a large amount of staying substances. The ratio of exposure to the developer is large, and the effect of the present invention of preventing re-adhesion of the support to the grain surface is not exhibited. Transfer speed is more than 2500mm / min5
000 mm / min or less is preferable. As described above, in the present invention, the PS plate is transported at a transport speed of 2000 mm / min or more, preferably substantially horizontally, and a developing solution is supplied to the image-exposed surface of the PS plate to perform development processing. Further, as is apparent from FIG. 1, in order to maintain the humidity of the developing processing section 3 and the washing processing section 4 at 80% or more, it is important to provide a blocking member for blocking the inside of each section described later. The development processing section 3 and the water washing processing section 4 are hermetically sealed, and the humidity of the processing section is set to 80% or more, thereby achieving the effect for the object of the present invention, that is, prevention of evaporation of the processing liquid by the blocking member. In addition, by providing the processing unit with a blocking member that blocks the outside air, the contact between the processing liquid and the outside air is suppressed, the life of the processing liquid is prolonged, and the liquid is prevented from splashing when the processing liquid is supplied. Become.

In the method of measuring humidity in the present invention, a humidity sensor is installed in front of a transport roller (squeegee roller) at the last of each tank in the developing section and the washing section.
In addition, when the sealing member for sufficiently sealing the blocking member was closed and when the sealing member was opened, it was set at the same position, and when closed, the measurement was performed such that the sealing member was always located inside the sealing member. The room in which the PS plate processing apparatus was installed was air-conditioned at 25 ° C. and 40% humidity, and the humidity at the time when the PS plate was continuously processed for 100 m ² was measured.

It is more effective to make the humidity of the developing section 3 and the washing section 4 preferably 90% or more.

The PS plate 10 is preferably made of a metal sheet, paper, a plastic sheet, a composite sheet obtained by laminating a plastic or a metal on a plastic sheet, or the like. Or an aluminum alloy sheet as a support, and a photosensitive diazo compound, azide compound, a compound having an ethylenically unsaturated double bond, a compound having an ethylenically unsaturated double bond, which is changed to a curable or soluble type by exposure to the one surface of the support, and an acid catalyst. Epoxy compounds that cause polymerization, silyl ether polymers that decompose with an acid, or a layer of a combination of a compound having a C—O—C— group and a photoacid generator are formed. There may be.

The image exposure of any PS plate 10 is carried out through a transparent original drawing having a line image or a halftone image from a light source such as a carbon arc lamp, a mercury lamp, a metal halide lamp, a xenon lamp, a chemical lamp, and a tungsten lamp. This is done by light.

The developing solution in the developing section 3 will be described. The developing solution is an aqueous alkali developing solution containing an alkali metal silicate, preferably [SiO ₂ ] / [M] (wherein
[SiO ₂ ] indicates the molar concentration of SiO ₂ , and [M] is
Shows the molar concentration of the alkali metal. ) Is in the range of 0.4 to 1.2, the content of SiO ₂ is 0.5 to 7% by weight, and the concentration of the alkali metal silicate is 0.1 to 10% by weight.
An alkaline aqueous solution of the range described above, and an alkaline aqueous solution in which other alkaline agents such as sodium hydroxide, potassium hydroxide, tribasic sodium phosphate, dibasic sodium phosphate, sodium carbonate, and potassium carbonate are added and dissolved as necessary. PH (25 ° C., the same applies hereinafter) of 12 or more, 13.5
The following alkaline aqueous solutions are used.

Next, the replenisher will be described. As a replenisher replenished to the developer in order to recover the deterioration of the developing ability due to the use of the developer or the like, the concentration of the alkali agent containing an alkali metal silicate is determined by the concentration of the developer. The above alkaline aqueous solution,
Preferably, [SiO ₂ ] / [M] is in the range of 0.15 to 0.8, the content of SiO ₂ is 0.5 to 7% by weight, and the concentration of alkali metal silicate in the developer is Concentration of alkaline aqueous solution, potassium hydroxide, sodium hydroxide, lithium hydroxide, tribasic sodium phosphate, dibasic sodium phosphate, tribasic potassium phosphate, dibasic potassium phosphate, tertiary phosphorus Inorganic alkali agents such as ammonium acid, dibasic ammonium phosphate, sodium metasilicate, sodium bicarbonate, sodium carbonate, potassium carbonate, ammonium carbonate and the like, mono-, di- or triethanolamine, tetraalkylammonium hydroxide, organic ammonium silicate, etc. 0.05 to 2 organic alkaline agents
An alkaline aqueous solution which is added and dissolved in a range of 0% by weight and whose pH is higher than the pH of the developing solution, preferably higher than the pH of the developing solution by 0.5 or more is used.

The above-mentioned developer and replenisher may contain various surfactants or organic solvents for the purpose of accelerating or suppressing development, dispersing development residue or increasing the ink-affinity of the lithographic printing plate, if necessary. The replenisher may be added in the range of 0.01 to 10% by weight, but when an aqueous alkaline solution having a pH or a concentration of alkali metal silicate higher than that of the developer is used for the replenisher, the replenisher is often replenished to the developer. At this time, the diluting water is also replenished so that the pH and the concentration are close to those of the developing solution. Therefore, a surfactant or an organic solvent may be added to the diluting water. In addition, additives such as an antifoaming agent and a water softener may be added to the developer and the replenisher.

Next, as the rinsing liquid in the water washing section 4, water or water containing a surfactant or the like is used. A liquid containing gum arabic, a starch derivative, or the like is used as the gum solution in the gum processing section 5. Before the operation of the processing apparatus, the replenisher and the diluting water as described above are supplied to the developing tank 30 of the developing unit 3 from the replenisher tank 11 and the dilution water tank 12 at an appropriate ratio, respectively, so that the developer has a predetermined concentration. Store as it is. A floating lid 39 may be floated on the stored developer in order to reduce the contact area with air to prevent oxidative deterioration. The temperature of the developer stored in the developing tank 30 is adjusted to a predetermined temperature by a heater (not shown), and the PS plate 10 causes the developing section 3 to move through the entrance transport roller 3.
2. While being transported by the outlet transport roller 38, the developing tank 3
The developer whose temperature is controlled from the shower pipe 31 at the end of the branch pipe 16 through the filter 13, the pump 14, the head chamber 15, and the branch pipe 16 from the entrance of the circulation path opened at the bottom of the PS plate 10 is used for image exposure of the PS plate 10. It is jetted and supplied to the surface and developed. Then, the used developer is stored in the developing tank 30 again and circulated for use.

The supply of the developer to the PS plate 10 is supplied by spraying through a shower pipe 31, but it may be supplied from a slit nozzle. When the developing solution in the developing tank 30 is circulated and used, the developing performance of the developing solution is reduced due to the elution or oxidation of the photosensitive resin of the PS plate 10 or the aluminum of the support, so that the developing performance is restored. For this purpose, the replenisher is replenished according to the processed amount and processing time of the PS plate. If the developing performance of the developing solution cannot be recovered even by replenishing the replenishing solution, the developing solution in the developing section 3 is sent to the waste liquid processing tank 18 via the valve 17 to clean the developing section 3 and the developing section 3 is cleaned. After supplying the developing solution to the developing tank 30, the developing is restarted.

At this time, as a method for examining the developing performance of the developing solution, it is preferable to determine the developing performance according to the throughput of the PS plate.
As for the detection of the processing amount of the PS plate, the processing amount may be detected from the size of the PS plate by the plate detecting means 2 provided near the entrance of the development processing unit 3. Also, the development processing unit 3
In a member such as the developing tank 30 or the entrance conveying roller 32 to which the sludge easily adheres, a linear expansion coefficient β = (dL / dt) / L ₀ (where L is length, t is temperature, and L ₀ is 0 It is preferable to use a material having a large temperature. Linear expansion coefficient β
By heating a member made of a material having a large diameter, the sludge that has adhered can be easily removed and removed. or,
If OH ^- is increased in the developing solution by electrolysis at a portion where the developing solution such as the developing tank 30 of the developing processing unit 3 is stored to maintain an appropriate high pH, the generation of sludge at the portion is prevented. Not only can this be suppressed, but also the generation of sludge at the portion where the high pH developer circulates can be suppressed.

The method is not limited to the above-described example in which the developer is circulated and used, and a method of supplying the necessary amount to the PS plate for processing the developer and disposing it may be employed. Although there is a problem that the consumption of the developing solution tends to increase for good development, the developing time is always shortened and constant because the developing is always performed with a new solution, and the developing solution is controlled by the flow of the developing solution. This solves the problem of sludge generation due to dissolved resin or oxidation, and is excellent in terms of stable development performance and simplified maintenance such as cleaning of the apparatus. Also in this method, the supply amount of the developer necessary for the PS plate is determined based on information such as the size, maker, and type of the PS plate, so that the development can be performed with a relatively small consumption of the developer. Can be.

Further, when the PS plate 10 passes between the rotating brush 35 and the lower receiving guide 34, the rotating brush 35 slides the surface of the image exposure to remove the photosensitive resin dissolved in the developing solution from the surface. It has been removed. Reference numeral 36 denotes a cover for the rotating brush.

As means for maintaining the humidity of the developing section 3 at 80% or more, for example, as shown in FIG. 4, a blocking member 7 for blocking the outside air is provided in the developing section 3. The blocking member 7 is a cover made of metal or resin, and the periphery of the cover is sealed with a sealing member 71 such as a rubber packing or the like to prevent the developer from being fatigued due to contact with outside air. The blocking member 7 serves to maintain the humidity of the development processing unit 3 and to prevent contact with the outside air, as well as to prevent evaporation of the processing liquid and to prevent liquid from splashing during shower development. The moisture evaporated in the development processing unit 3 is condensed on the inner surface of the blocking member 7 and returns to the inside of the processing tank along the inclination of the inner surface to prevent the developer from being concentrated by evaporation. Although not shown in the figure, the humidity sensor is installed in front of the outlet conveyance roller 38, and the humidity at the time when the PS plate is continuously processed by 100 m ² is defined as the humidity of the developing unit.

The developing section 3 will be described in detail with reference to FIG.
When the sheet is inserted into the development processing section from the PS plate conveyance path A formed substantially horizontally as indicated by a dashed line in FIG.
mm / min or more.

While being supported by the guide member 9, the sheet is conveyed by the entrance conveyance roller 32 and the exit conveyance roller 38,
The process moves to the next step from the plate developing section outlet 82. While the PS plate is being conveyed by the entrance conveyance roller 32 and the exit conveyance roller 38, the developer is supplied to the shower pipe 31 as described above.
From the PS plate toward the image-exposed surface of the PS plate, and subjected to shower development. Then, the image exposure surface of the PS plate is rubbed by the rotating brush 35, and the photosensitive resin dissolved in the developer is removed from the surface. During the shower development, the squeezing roller 8
May be provided. If the squeeze roller 8 is driven by the same drive shaft as the transport roller, it is not necessary to provide a new drive source. By providing the squeezing roller 8, the PS
By wiping the developing solution that has reacted with the photosensitive layer once on the plate and supplying a new solution, it is possible to promote the reaction in a shorter time. The squeeze roller 8 can obtain the same effect by using a blade or air pressure. other,
In order to promote the reaction between the photosensitive layer and the developer on the PS plate, the number of shower pipes can be increased, or the PS plate can be vibrated to agitate the developer on the plate.

A bat 37 for immersing the lower part of the lower roller of each roller pair may be provided below the inlet conveying roller 32, the outlet conveying roller 38 and the squeezing roller 8. This is provided to prevent sludge from sticking to a transport roller or the like, and to always wet the roller to prevent sticking of the developer. The vat 37 contains a developer and dilution water, and the developer and dilution water can be circulated and used. The developed PS plate is transported to the rinsing section 4 by the exit transport roller 38.

Next, the washing section 4 will be described.
The rinsing tank 40 of the rinsing section 4 also supplies a rinsing liquid from a rinsing liquid supply means (not shown) and stores the rinsing liquid at a predetermined level before the operation of the processing apparatus. When the washing is performed, the water is circulated through a rinse liquid circulation path provided with a shower pipe 42 at a terminal that returns to the inside of the washing tank 40 through the pump 41 from an inlet opening at the bottom of the washing tank 40. That is, the rinsing liquid is spray-supplied from the nozzle of the shower pipe 42 to the PS plate 10 sent by the transport roller 43 in the washing tank 40,
The developer adhering to the plate 10 and the photosensitive resin dissolved in the developer are washed away and collected at the bottom of the washing tank 40, and are again supplied to the PS plate 10 from the nozzle of the shower pipe 42 through the rinse liquid circulation path. You. It is preferable that the total area of the blow-out holes of the shower pipe is set to 1/2 to 1/3 of the cross-sectional area of the pipe. This rinsing liquid is also a predetermined number of PS
When the plate 10 is washed with water and the washing ability is reduced by a developer or the like, the rinsing liquid in the washing section 4 is dropped into the waste rinsing liquid tank 45 via the valve 44 without further development, and the washing section 4 is washed. Is cleaned, and development is restarted after the rinsing liquid is renewed. In the rinsing section 4, water containing water or a surfactant is used as rinsing water.

Here, another application example of the washing section will be described with reference to FIG. This application example is a system in which washing water is supplied to a tank on the downstream side in the transport direction of the PS plate 10 by a multi-stage countercurrent washing method, and the washing is performed by sequentially overflowing the tank on the upstream side. The squeeze blade 47 provided above the partition plate of each tank is made of a flexible film such as a PET film for preventing backflow of washing water. Below the squeeze blade 47, there is a squeeze blade receiving roller 48 also serving as a PS plate transport guide. The bat 46 immerses the lower part of the lower roller of the transport roller 43. The rinsing tank 40 is provided below the transport path to circulate and use the rinsing water. A floating lid 49 is provided in the washing tank 40, and a float switch (not shown) is further provided so that when a drop in the liquid level is detected, the liquid is automatically supplied. By using a multi-stage countercurrent washing method, there is an advantage that washing can be performed with a small amount of washing water and the amount of waste liquid can be reduced. Although two tanks are shown in the figure, at least two tanks are sufficient. The tank for storing the final overflow liquid may be provided, for example, outside the processing apparatus (not shown). As described above, the PS plate 10 washed in the water washing section 4 is sent to the gum processing section 5.

As described above in the developing section 3, as means for maintaining the humidity of the washing section 4 at 80% or more, for example, a blocking member 7 for blocking the outside air is provided as shown in FIG. The blocking member 7 is as described above in the development processing section 3. Although not shown in the figure, the humidity sensor is installed in front of the conveying roller 43 near the outlet, and the humidity at the time when the PS plate is continuously processed for 100 m ² is defined as the humidity of the water washing section.

Next, the gum processing section 5 will be described with reference to FIG. In the gum solution tank 50, the gum solution is supplied in advance from a gum solution supply means (not shown) and stored at a predetermined level.
When the PS plate 10 is fed by the transport roller 53 in the gum processing section 5, the gum solution passes through the pump 51 from the inlet opened at the bottom of the gum solution tank 50 and returns to the gum solution tank 50 through the gum solution circulation path. Is supplied to the PS plate 10 from the nozzle of the shower pipe 52 of the terminal. PS plate 10 is transport roller 5
3, while the gum solution from the gum solution tank 50 is applied from both sides of the PS plate 10 through the shower pipe 52, and the PS plate passes through the crossover roller 56 and the drying unit 6
Transported to

Next, the drying section 6 will be described. The transfer section roller 56 and the transport roller 62 are provided with gummed P
The roller is provided with a warp so that the area of contact until the S plate is dried is reduced. The discharge roller 63 is a cloth Molton roller. The PS plate 10 passes through the transfer roller 56 and enters the drying unit 6, and the PS plate 10 is sent by the conveying rollers 62 and 63, during which hot air from the air nozzle 61 hits the surface of the PS plate 10, Dry P
The S plate is discharged out of the processing apparatus. In addition, drying may be performed by irradiating infrared rays in addition to the warm air, and a stocker for stocking a PS plate (not shown) may be connected to the outlet of the processing apparatus.

Next, a PS plate processing apparatus showing another mode different from the above will be described. In the PS plate processing apparatus shown in FIG. 5, an insertion section I for inserting the PS plate 10, a development processing section 3 for development, a rinsing processing section 4 for rinsing, a gum processing section 5 for performing post-processing such as rinsing and gumming. Drying unit 6 for drying
It mainly comprises a control mechanism (not shown) for controlling the operation of the processing liquid feed pump and the like. Insertion part I,
An insertion table 1 for guiding the insertion of the PS plate 10, plate detection means 2, which is an optical sensor for detecting the insertion of the PS plate 10 by reflected light,
An inlet conveyance roller 32 for nipping and conveying the PS plate 10 is provided. The development processing unit 3 is configured to convey the PS plate 10 in a curved manner in the developing solution put in the developing tank 30 by the conveying roller pair 3a and the conveying roller 3b. During this, the developing solution in the developing tank 30 is sent to the shower pipe 31 by the pump 14, and the developing solution is sprayed on the photosensitive layer surface of the PS plate 10. Further, in the immersed state, the PS plate 10 is nipped by the plate pressing roller 3c and the rotating brush 35, and the surface thereof is rubbed by the rotating brush 35 to promote the development. The squeegee is transported to the washing section 4. Although not shown, the humidity sensor is installed in front of the outlet conveyance roller 38, and the humidity at the time when the PS plate is continuously processed by 100 m ² is defined as the humidity of the development processing unit.

The developer in the developing tank 30 is maintained at a predetermined temperature range by the heater H.

To replenish the developing solution in the developing tank 30, the concentrated developing replenishing solution in the concentrated developing replenishing solution tank 11 is pumped by a pump 14.
a, the dilution water in the dilution water tank 12 is sent to the liquid preparation tank T by a pump 14b at a predetermined ratio, and mixed in the tank T to form a developing replenisher.
P being transported from the shower pipe 31 located immediately before
The developer is supplied onto the S plate 10 to replenish the developer in the developing tank 30. The developing solution overflowing from the developing tank 30 is returned to the developing tank 30 by a pump 14d, and further has a replenishing circuit (not shown) for replenishing the PS plate 10 in accordance with the processing of the PS plate 10. ing.

The rinsing section 4 includes a rinsing tank 4 for storing rinsing water.
0, pump 41, shower pipe 42, transport roller 43
Mainly consisting of Here, the water washing section 4
As a means for maintaining the humidity of the developing unit 3 at 80% or higher, the same blocking member 7 for blocking the outside air as shown in FIG. 5 is used. Section 3 is as described above. Although not shown, by sealing the periphery with a sealing member such as rubber packing,
It is possible to further improve the airtightness. Although not shown in the figure, the humidity sensor is installed in front of the conveying roller 43 near the outlet, and the humidity at the time when the PS plate is continuously processed for 100 m ² is defined as the humidity of the water washing section.

The gum processing section 5 includes a gum solution tank 50 for storing a finisher solution (rinse solution, gum solution, etc.), a pump 51,
It mainly comprises a replenishing mechanism (not shown) for replenishing according to the processing of the shower pipe 52, the transport roller 53 and the PS plate 10. In the figure, * 1 and * 1, * 2 and *
2 are connected by piping. The drying section 6 mainly includes an air nozzle 61 and a transport roller 63.

A large number of plate detecting means 2 provided at the insertion portion I of the automatic developing machine are arranged at equal intervals over the width direction of the automatic developing machine. Is detected, and this detection signal is integrated by a replenishment circuit (not shown) to obtain an integration signal. The pump 14 (a, b, c) is replenished with a required replenishment amount proportional to the integrated area. It is configured to control operation. Further, it is preferable that the replenishment circuit has a function of replenishing a fixed amount of replenisher per unit time regardless of the processing of the PS plate.

As described above, the PS plate is developed at a high speed in the compact developing section, and the humidity of each of the developing section and the rinsing section is maintained at 80% or more, that is, a sealing member is provided to provide airtightness. By maintaining the humidity of the development processing section by improving the, peeled or eluted during the development processing,
The amount of ballpoint pen ink drawn on the PS plate attached to the surface of the PS plate support can be reduced. In addition, it has the additional effects of improving the life of the processing solution by preventing contact between the developing solution and the outside air, preventing evaporation of the processing solution, and preventing splashing of the solution during shower development.

[0042]

EXAMPLES The present invention will be described below in detail with reference to examples, but embodiments of the present invention are not limited thereto.

<< Preparation of photosensitive lithographic printing plate >> (Preparation of support) An aluminum plate (JIS-1050) having a thickness of 0.24 mm is immersed in a 10% aqueous solution of sodium hydroxide at 85 ° C. and degreased for 1 minute. And then washed with water. The degreased aluminum plate was immersed in a 25% aqueous 10% sulfuric acid solution for 1 minute, desmutted, and then washed with water. Next, the aluminum plate was electrochemically roughened in a 1.0% nitric acid aqueous solution at a temperature of 30 ° C. and a current density of 50 A / dm ^{2 so as} to have an electric quantity of 400 c / dm ² . Thereafter, chemical etching is performed in a 50 ° C. 10% aqueous sodium hydroxide solution so that the amount of aluminum dissolved is 3 g / m ^2, and the aluminum plate is immersed in a 25 ° C. 10% nitric acid aqueous solution for 10 seconds and desmutted. Washed with water. Then, a current density of 2 A / d in a 35% 20% aqueous sulfuric acid solution.
Anodizing treatment was performed at m ² for 1 minute. After that, it is immersed in a 0.1% ammonium acetate aqueous solution at 80 degrees for 30 seconds,
A sealing treatment was performed, followed by drying at 80 ° C. for 5 minutes to prepare a support.

Next, a coating solution of a photosensitive composition having the following composition was applied to the surface of the obtained aluminum support using a wire bar, and dried at 80 ° C. for 2 minutes to obtain a PS plate. At this time, the photosensitive composition coating solution had a dry weight of 2.0 g / m2.
^{It was set to 2} .

<< Coating Solution for Photosensitive Composition >> Polymer Compound 1 0.20 g Hydroxypropyl-β-cyclodextrin 0.20 g Novolak resin (molar ratio of phenol / m-cresol / p-cresol is 10/54/36) 6.70 g Condensation product of pyrogallol acetone resin (Mw: 3000) and O-naphthoquinonediazide-5-sulfonyl chloride (esterification ratio 30%) 1.50 g Polyethylene glycol # 2000 0.20 g Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.) 0.08 g 2,4-bis (trichloromethyl) -6- (P-methoxystyryl) -S-triazine 0.15 g Fluorinated surfactant FC-430 (Sumitomo 3M Co., Ltd.) 0.03 g cis-1,2 cyclohexanedicarboxylic acid 0.2 0 g methyl ethyl ketone / propylene glycol monomethyl ether = 3/7 100 ml

[0046]

Embedded image

Using a 2 kW metal halide lamp as a light source, the obtained PS plate was 70 cm at 8 mW / cm ² .
Exposure was performed by irradiating from a distance of 60 seconds. The exposed PS plate was charged in a developing solution (35 degrees) having the following composition charged in an automatic developing machine of the type shown in FIGS.
Development processing was performed for 0 seconds. In addition, 25 L of the following developer was put into the developing tank of the automatic developing machine, and tap water was poured into the washing tank.
The finisher tank was charged with 10 L of a 2-fold dilution of the finisher gum solution, and the temperature was controlled.

More specifically, the transport speed is 1400 mm / min,
The development was carried out at a rate of 2800 mm / min. With the horizontal transfer type shown in FIG. 1 and the immersion type shown in FIG. 5, the blocking member was closed and partially opened, respectively. Although an automatic developing machine with a different length was used, only one type of developing layer is schematically illustrated in the drawings. Hereinafter, the development processing was performed by the combination shown in Table 1, respectively.

<< Developer >> Potassium A silicate 100 parts by weight (SiO ₂ /M=0.4, Si concentration 2 wt%) Potassium hydroxide 86 parts by weight Water 1513 parts by weight << Finisher gum solution >> White dextrin 5.0 parts by weight Hydroxypropyl etherified starch 10 parts by weight Gum arabic 1.0 part by weight Ammonium phosphate 0.1 part by weight Sodium dilauryl succinate 0.15 part by weight Polyoxyethylene nonylphenyl ether 0.5 part by weight ethylene glycol 1.0 Parts by weight EDTA 0.005 parts by weight Dehydroacetic acid 0.005 parts by weight Water 100.0 parts by weight Thereafter, evaluation was made according to the following evaluation method.

<< Ball Pen Remaining >> Load 50, PS
The image was drawn using an oil-based ballpoint pen (manufactured by Pilot) over 75 and 100 g. After that, exposure under the conditions described above,
After performing a development treatment, the degree of residual ballpoint pen ink on the obtained lithographic printing plate was visually evaluated according to the following evaluation criteria.

◎: No residual ink at all ・ ・ ・: A small amount of residual ink is visible △: The residual ink is somewhat noticeable X: Many residual inks are noticeable

The results are shown below.

[0053]

[Table 1]

Horizontal Sealing A development processing apparatus of the horizontal transport type shown in FIG. 1 in which the blocking member is sealed using a sealing member.

Immersion Sealing The development processing apparatus of the immersion type shown in FIG. 5 in which the blocking member is sealed using a sealing member.

Horizontal Opening The developing apparatus of the horizontal transport type shown in FIG. 1 in which a blocking member is partially opened without using a sealing member.

Immersion Opening The developing apparatus of the immersion type shown in FIG. 5 in which the blocking member is partially opened without using the sealing member.

As is clear from Table 1, it can be seen that the developing apparatuses 1 and 2 using the developing method of the present invention can produce a lithographic printing plate having a very excellent degree of residual ballpoint pen ink. However, the processing devices 3 to 8 of the comparative examples
In each case, the residual degree of the ink is at a level at which there is a problem in practice, and it is understood that it is important that both the transport speed of the PS plate and the humidity of the developing section and the washing section are within the range of the present invention.

[0059]

According to the present invention, the above-described configuration has a remarkably excellent effect that the phenomenon of the ball-point pen residue occurring in the development processing is improved. In addition, it also has the attendant effects of improving the service life of the processing solution, preventing evaporation of the processing solution, and preventing splashing during shower development. Further, according to the present invention, the efficiency of workability can be improved by increasing the transport speed of the PS plate, and the effect that color contamination such as reddish color does not occur on the surface of the PS plate itself also occurs.

[Brief description of the drawings]

FIG. 1 is a configuration sectional view showing an example of a PS plate processing apparatus of the present invention.

FIG. 2 is a front sectional view showing a configuration of a development processing unit in FIG. 1;

FIG. 3 is a cross-sectional view illustrating a configuration of a water washing section according to another application example.

4A and 4B are an enlarged configuration cross-sectional view and a side configuration cross-sectional view, respectively, of a blocking member of the development processing unit in FIG.

FIG. 5 is a sectional view showing the configuration of another example of the PS plate processing apparatus of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 insertion table 2 plate detection means 3 development processing part 4 washing processing part 5 gum processing part 6 drying part 7 blocking member 8 squeezing roller 9 guide member 10 PS plate 11 replenisher tank 12 dilution water tank 18 waste liquid processing tank 30 developing tank 31 shower Pipe 32 Inlet transport roller 34 Lower receiving guide 35 Rotary brush 38 Outlet transport roller 40 Rinse tank 71 Sealing member 81 PS plate development processing unit inlet 82 PS plate development processing unit outlet A PS plate conveyance path

Claims (2)

[Claims] 1. A conveying speed of 2000 mm / min or more, and a humidity of a developing section and a washing section of 8
A photosensitive lithographic printing plate development processing apparatus, wherein the content is 0% or more. 2. A method for developing a photosensitive lithographic printing plate, comprising performing a developing process using the developing device according to claim 1.