JPH1039517A - Processing method for photosensitive planographic printing plate material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the hardening of the squeezing roll of a developing tank and to diminish a developing soln. brought from the developing tank into the next processing tank by controlling the surface temp. of the squeezing roll. SOLUTION: An automatic processing machine used for processing a photosensitive planographic printing plate material has a developing part A1 adopting a dip developing system and a rinsing part B1 just behind the part A1 . The developing part A1 has a developing tank 50 and a means of conveying the printing plate material into a developing soln. in the tank 50. A squeezing roll 13a has been disposed at the rear part of the developing part A1 . The pref. temp. of the roll 13a is 25-80 deg.C, especially 30-40 deg.C and the temp. of the roll 13a is controlled by building an electric heater into the central part of the roll, disposing the heater in contact with the roll or blowing hot air on the roll. A thermostat is preferably used in combination. The printing plate material is preferably conveyed at >=1,500mm/min rate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for processing a photosensitive lithographic printing plate material using an automatic processor.

[0002]

2. Description of the Related Art Conventionally, an automatic developing machine is generally used for processing a photosensitive lithographic printing plate material (hereinafter also referred to as a photosensitive material) exposed to an image to form a printing plate.
While transporting the photosensitive material, a developing solution is applied and developed, followed by post-processing such as washing with water and rinsing.

When a large number of photosensitive lithographic printing plate materials are processed using an automatic developing machine, the developer adhering to the printing plate is mixed into the next processing tank such as a washing tank, and stains the tank. There are problems such as the generation of water and sludge, and the effect of cleaning the printing plate surface or rendering it hydrophilic by the treatment liquid in the tank being exhausted. These problems are likely to occur in winter and cold regions.
For this reason, the processing tank in the next step of the development process is not replaced with a plurality of tanks, and the processing liquid that has been exhausted is periodically replaced to prevent the generation of dirt and sludge, or the processing liquid in the processing tank is drained to clean the inside of the tank. We are cleaning and responding. However, since the replacement of the processing liquid is a burden on the operator, it is desired to reduce the frequency of replacing the processing liquid.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to process a photosensitive lithographic printing plate material using an automatic developing machine. An object of the present invention is to reduce mixing into a processing tank.

[0005]

SUMMARY OF THE INVENTION The object of the present invention is to provide a photosensitive lithographic printing plate material which controls the surface temperature of a squeeze roller in a developing tank when the photosensitive lithographic printing plate material is processed using an automatic developing machine. , The temperature is maintained at 25 ° C. or more, and the photosensitive lithographic printing plate material is
This is achieved by conveying at a speed of 0 mm / min or more.

In other words, the present inventor believes that the above-mentioned problem is caused by the fact that the squeeze roller is hardened due to a decrease in temperature and the like and the squeeze performance is degraded and the carry-in amount of the developing solution is increased. Thus, curing was prevented, leading to the present invention.

Hereinafter, the present invention will be described in detail for each item.

<< Squeeze Roller >> In the present invention, the squeeze roller whose temperature is controlled has a contact point with the printing plate above the liquid level of the developing tank storing the developing solution, and is located at the rear of the developing tank. This is a roller for squeezing and removing the developer adhering to the roller. The roller is preferably located at a position where the squeezed printing plate is fed into a processing tank next to a developing tank such as a second developing tank, a washing tank, a rinsing tank or a gum tank. As the squeeze roller itself, a commonly used one can be used. As the material of the squeeze roller, it is preferable to use a rubber roller of butyl resin, EPPM, silicon, neoprene or the like from the viewpoint of chemical resistance.

Although the temperature of the squeeze roller depends on the material of the roller surface, it is generally preferably 25 ° C. to 80 ° C., and more preferably 30 ° C. to 40 ° C. If the temperature is lower than 25 ° C., the squeeze roller may be hardened and sludge may be generated. If the temperature is higher than 80 ° C., the effect of the present invention cannot be obtained effectively.

[0010] The temperature of the squeeze roller can be controlled by a method such as incorporating an electric heater in the center of the roller, providing a heater in close contact with the roller, or blowing hot air onto the roller. Use rollers. Further, it is preferable to use a thermostat in combination.

<< Automatic Developing Machine >> FIG. 1 is a diagram showing a schematic configuration of an example of an apparatus for performing the processing method of the present invention. Automatic developing machine shown in the figure, immersion development method has a developing unit A ₁ and rinsing unit B ₁ subsequent by, the developer in the developing tank 50 and the developing tank 50 developing section A ₁ is subjected to immersion development A squeeze roller 13a is disposed at the rear of the developing unit. The concentrated developing replenisher in the concentrated developing replenisher tank 16 or the diluting water in the diluting water tank 18 is supplied to the developing tank 50 by the pump 9a. The selection of whether to send the concentrated development replenisher or the dilution water is made by opening and closing the valves 51a and 51b.

[0012] In the rinsing unit B _1, the printing plate is washed with wash water water is rinsing liquid in the rinsing liquid tank 53 is supplied from the nozzle pipe 11a with the pump 9b, the automatic developing machine is squeezed by the squeeze roller 13b It is carried out.

In addition to the above, the automatic developing machine is provided with a sensor for detecting the insertion, length, and area of the photosensitive material, and a detecting means for detecting the performance of the developing means of the developing means in the developing means and the conveying means such as a pair of conveying rollers. And at least means for controlling the operation of the pump so as to maintain the temperature of the processing liquid within a predetermined range.

FIG. 2 shows a schematic configuration of another example of the automatic developing machine. In the automatic developing machine shown in the figure, the photosensitive material 1 is inserted from the left end in the figure with the photosensitive layer face up, and a developing section A ₂ and a rinsing section B ₂
The developer and other processing liquid are applied to the photosensitive layer and processed while the gumming portion C is horizontally transported rightward along the transport path PS by transport means such as the transport roller pair 5 and the transport roller 6. Things.

[0015] In the developing unit A _2, the developer in the developer tank 8 is fed to the nozzle pipe 11b by a pump 9c, it is applied is injected from the nozzle pipe 11b and the photosensitive layer of the photosensitive material 1. The photosensitive layer to which the developer has been applied is a rotating brush 12a.
It is rubbed by being eluted developed and sent is squeezed by squeeze rollers 13c to rinse section B _2.

The developing section A ₂ has a developing tank 14 below the transport path PS, and is sprayed from the nozzle pipe 11b to the developing tank 1
The developer that has flowed into the tank 4 returns to the developer tank 8 and is circulated and used. In order to recover the fatigue of the circulated developer, the concentrated developer replenisher tank 16
The concentrated developing replenisher therein is sent to the developing tank 14 by the pump 9d to be replenished. Furthermore, the developing solution in the developing solution tank 8 which has reached the limit of fatigue due to circulating use can be discharged to the waste liquid tank 19 by opening the valve 20.

The squeeze printing plate squeeze roller 13c, in the rinse section B _2, the rinsing liquid tank 3
The rinsing liquid (including the washing liquid) in 0 is supplied from the nozzle pipe 11c by the pump 9f, rubbed by the brush roller 12b, squeezed by the squeeze roller 13d, and transferred to the gumming section C which is the next processing step. Conveyed. The rinse liquid injected from the nozzle pipe 11c and flowing down into the rinse tank 31 returns to the rinse liquid tank 30 and is used for circulation.

In the gum pulling section C, the gum solution in the gum solution tank 40 is fed by the pump 9g and applied to the upper surface of the printing plate being conveyed from the nozzle pipe 11d, and then squeezed by the squeeze roller 13e to be automatically squeezed. It is carried out of the developing machine. Gumming tank 4 sprayed from nozzle pipe 11d
The gum solution flowing down into 1 is returned to the gum solution tank 40 and used for circulation.

In the present invention, the number, length and area can be detected (see JP-A-61-182041), or the plate impedance (JP-A-61-1).
17547), liquid conductivity (Japanese Patent Laid-Open No. 61-16 / 1986).
2049), pH of the solution (JP-A-60-1423)
It is preferable that the detection and / or measurement results are fed back to the development replenishment conditions and the replenishment is carried out using an automatic developing machine capable of measuring J.I.

The automatic developing machine used in the present invention preferably has a closed structure for preventing air contact and evaporation. For example, a partition plate that opens and closes in accordance with the passage of the photosensitive material and does not come into contact with the photosensitive material and is provided at the outlet and / or entrance of the photosensitive material of the automatic developing machine, A partition plate such as a plastic blade is provided at the outlet and / or the inlet, a floating lid is provided on the surface of the developing solution, a carbon dioxide removing device for removing carbon dioxide from air in the developing space is provided, It is preferable to provide a humidifier for humidifying the air. It is also preferable to have a structure in which at least a part of the washing waste liquid is reused as dilution water for the developing replenisher.

The automatic developing machine used in the present invention is an immersion developing system (JP-A-57-64237 and JP-A-6-236).
No. 041), a new solution coating and developing method (Japanese Patent Laid-Open No. Sho 62-62).
It is preferable to use any one of the developing methods of a shower developing method (see Japanese Patent Application Laid-Open No. 58-95349) and a slit developing method (see Japanese Patent Application Laid-Open No. 62-288845). The shower development system is particularly preferred. It is preferable from the viewpoint of operability that the processing liquid can be automatically changed.

In the present invention, even if the photosensitive material is conveyed at a high speed of 1500 mm / min to 4000 mm / min, good squeezing performance can be obtained, and the present invention can be carried out at a conveying speed of 2500 to 3500 mm / min. The effect of is fully demonstrated.

<< Photosensitive lithographic printing plate material >> As the photosensitive lithographic printing plate material to which the processing method of the present invention is applied, for example,
A negative photosensitive lithographic printing plate material having a photosensitive layer containing a diazo compound on a support, or a photosensitive layer containing a photopolymerizable and / or photocrosslinkable photosensitive composition, and an orthoquinonediazide compound on a support And a positive photosensitive lithographic printing plate material having a photosensitive layer containing

The photosensitive lithographic printing plate material can be exposed by a usual method. For example, a transparent original image having a line image, a halftone dot image, or the like is brought into close contact with a photosensitive surface and exposed, and then the photosensitive layer in the non-image area is removed using an appropriate developing solution to obtain a relief image.

When the support is made of aluminum, the light-sensitive material to which the processing method of the present invention is applied is preferably provided with a back surface layer for suppressing elution of aluminum from the back surface of the support. JP-A-6-35174 can be referred to as the technique.

<< Treatment Solution >> A negative photosensitive lithographic printing plate having a photosensitive layer containing a photopolymerizable and / or photocrosslinkable photosensitive material on a support, and an orthoquinonediazide compound on a support, The positive photosensitive lithographic printing plate having a photosensitive layer containing as a developer can be developed using a common developing solution and a developing replenisher.

An aqueous alkaline developer containing an alkali metal silicate is used as a developer, and the SiO ₂ concentration and [SiO ₂ ] / [M] in the developer (where [SiO ₂ ] is Si
The molar concentration of O ₂ is shown, and [M] is the molar concentration of the alkali metal. ) Is SiO ₂ = 0.5 to 6 wt%, [S
iO ₂ ] / [K] = 0.35-1.0, especially SiO ₂ = 1
~ 3, when [SiO ₂ ] / [K] = 0.4 to 0.7,
And the developing replenisher for the developer is SiO ₂ = 0.5 to
6 wt%, [SiO _2] /〔K〕=0.2～0.8, especially SiO ₂ = 1～4Wt%, [SiO _2] / [K] = 0.
In the case of 3 to 0.7, the effect of the present invention is more remarkable.

The aqueous alkaline developer containing the alkali metal silicate includes potassium silicate, sodium silicate,
Sodium metasilicate, those containing potassium metasilicate etc., these include sodium hydroxide, potassium hydroxide,
Other alkali agents such as sodium triphosphate, sodium phosphate dibasic, sodium carbonate, potassium carbonate and the like can be contained. At this time, the concentration of the alkaline aqueous solution is
Although it depends on the type of the photosensitive composition and the alkali, a range of 0.1 to 10% by weight is generally appropriate.

Examples of the alkali silicate to be contained in the developer include potassium silicate, sodium silicate, sodium metasilicate, potassium metasilicate and the like, and potassium silicate is preferred.

A nonionic surfactant may be added to the developer. The addition amount of the nonionic surfactant is 0.01 to 1
0% by weight, preferably 0.02 to 2% by weight
Range.

The developing replenisher may be composed of two or more liquids. However, the developing replenisher is composed of one liquid because the supply section of the replenishing device, the storage tank, and the like become complicated and the apparatus becomes large. Is preferred.

The pH of the developer (25 ° C., the same applies hereinafter) is 1
The pH is preferably 2 or more and 13.5 or less.
It is preferably 12.5 or more and 14 or less, and the pH of the developing replenisher is preferably 0.3 or more higher than the pH of the developing solution.

The rinsing liquid (water washing liquid) can be used without particular limitation as long as it is a liquid for removing the developing solution component and the photosensitive layer eluting component from the developed printing plate to clean them. As the rinsing liquid, for example, those described in JP-A-63-172270 can be preferably used. Use a gum solution that removes the alkaline developer component adhering to the developed printing plate, changes the lithographic printing plate to a property that is easily compatible with water, and forms a film that prevents scratches and stains. For example, a finisher described in JP-A-4-314054 can be used.

[0034]

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

Example 1 << Preparation of a positive photosensitive lithographic printing plate material >> 0.24 m thick
m JIS-1050 aluminum plate is immersed in a 2% aqueous sodium hydroxide solution, degreased, electrochemically roughened in a dilute nitric acid solution, washed well, and then diluted in a dilute sulfuric acid solution. Anodizing treatment was performed to form a 2.0 g / m ² oxide film on the surface of the aluminum plate. The thus treated aluminum plate was washed with water, dried, coated with a photosensitive solution having the following composition to a dry weight of 2.0 g / m ^2, and dried to obtain a positive photosensitive lithographic printing plate material.

(Photosensitive Coating Composition) An ester compound of naphthoquinone- (1,2) -diazide- (2) -5-sulfonic acid chloride and pyrogallol / acetone resin (Japanese Patent Application Laid-Open No. Sho 60-143345) 2.7 parts by weight Copolycondensation resin of phenol and m-, p-mixed cresol and formaldehyde (the molar ratio of each of phenol, m-cresol and p-cresol at the time of synthesis was 10) : 54:36, weight-average molecular weight Mw = 5500) 7.0 parts by weight Novolac resin synthesized from p-tert-octylphenol and formaldehyde and naphthoquinone- (1,2) -diazide (2) -5-sulfonic acid Ester compound with chloride (condensation ratio: 50 mol%, Mw = 1700) 0.1 part by weight Polyethylene glycol 0.1% by weight naphthoquinone- (1,2) -diazide- (2) -4-sulfonic acid chloride 0.05 part by weight Victoria Pure Blue BOH ( Hodogaya Chemical Co., Ltd.) 0.08 parts by weight Ethyl cellosolve 80 parts by weight Methyl cellosolve 20 parts by weight << Preparation of negative photosensitive lithographic printing plate material >> JP-A-3-59
A negative photosensitive lithographic printing plate was prepared according to the examples described in JP-A-666. The photosensitive solution is the photosensitive solution [A] in the embodiment.
-1 was used.

An original film having a halftone dot pattern corresponding to each of the above photosensitive materials and a step tablet for sensitivity measurement (No. 2, manufactured by Eastman Kodak Co., Ltd., gray scale of 21 steps each having a density difference of 0.15) are closely attached. ,
8.0mW / using 2kW metal halide lamp as light source
Exposure was performed for 60 seconds from a distance of 70 cm under the condition of cm ² .

Next, a developer and a replenisher having the following compositions were charged into the automatic developing machine shown in FIG. 1 and the above-described positive-working photosensitive lithographic printing plate material and the negative-working photosensitive lithographic printing plate material which had been subjected to image exposure were prepared. At 30.degree. C. for 12 seconds.

In the processing, the positive type photosensitive lithographic printing plate material and the negative type photosensitive lithographic printing plate material were each treated in a chrysanthemum size at 1 day each.
50 editions and a total of 200 editions of 50 editions for 2 weeks, 2 editions in total
400 editions were performed. The processing order was random.

<< Development Initiation Solution (pH: 12.74) >> Potassium A-silicate (SiO ₂ : 26 wt%, K ₂ O: 13 wt%) 100 parts by weight Potassium hydroxide 19 parts by weight Water 1200 parts by weight << Concentrated development replenisher A potassium silicate (SiO ₂ : 26 wt%, K ₂ O: 13 wt%) 100 parts by weight Potassium hydroxide 22 parts by weight Water 40 parts by weight With respect to 162 parts of the above concentrated developer replenisher, 600 parts of dilution water (pH: 6) .5) and a replenisher for development (pH: 13.3)
1).

The replenishment amount of the development replenisher is 70 m for processing replenishment.
1 / m ² , replenishment with time: 240 ml / h, daily replenishment (replenishment during the non-operation period of the automatic developing machine, replenished at the start of operation of the automatic developing machine): 200 ml / h. The above-mentioned replenishment amount is an amount after the concentrated development replenisher is diluted with water.

Water was used as the rinsing liquid for the rinsing part B ₁ . The transport speed was 2800 mm / min.

The treatment was performed under the following conditions.

(Processing 1) An electric heater was mounted inside the squeeze roller 13a, and the temperature of the roller surface was controlled by a thermostat so as to be 35 ° C. The squeeze roller was made of rubber made of butyl resin.

(Process-2) The process was performed in the same manner as process-1 except that the roller surface temperature was controlled at 50 ° C.

(Comparative treatment-1) The treatment was carried out without controlling the surface temperature. The roller surface temperature was 20 ° C.

<< Evaluation >> After each processing was completed, the following evaluation was performed using the lithographic printing plate prepared by the processing.

(Recovery of Soil) The obtained lithographic printing plate was smeared with ink (described below) on the entire surface, and then coated on a coated paper using a printing machine manufactured by Mitsubishi Heavy Industries, Ltd .; Fountain solution manufactured by Ink Co., Ltd .; etch liquid SG-51
(Density 1.5%), printing using Toyo Ink Co., Ltd. ink; High Plus M Red, and the number of sheets from the start of printing until a clear and complete image was obtained was evaluated.

(Small dot stains) When printing was performed 5,000 times, the printing machine was temporarily stopped, and printing was resumed after one hour, the number of small dot stains generated was an average of the number within 100 cm ² . evaluated.

(Background Smear at the Time of Printing) The presence or absence of stain on the printed matter was visually observed and evaluated according to the following criteria.

◎: No dirt at all ○: Slight dirt seen, but practically no problem.

X: Stain is considerably seen.

Table 1 shows the above results.

[0054]

[Table 1]

[0055]

As demonstrated in the examples, according to the present invention, the squeeze roller of the developing tank can maintain good squeeze performance.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an example of an automatic developing machine for photosensitive lithographic printing plate material.

FIG. 2 is a schematic configuration diagram showing another example of the automatic developing machine.

[Description of Signs] 1 Photosensitive lithographic printing plate material (photosensitive material) A ₁ , A ₂ developing section B ₁ , B ₂ rinsing section C gumming section PS transport path 5 transport roller pair 6 transport roller 8 developer tank 9a to 9g Pump 11a-11d Nozzle pipe 13a-13e Squeeze roller 50 Developing tank 16 Concentrated developing replenisher tank 18 Dilution water tank 30 Rinse liquid tank 31 Rinse tank

Claims (3)

[Claims] 1. A method for processing a photosensitive lithographic printing plate material, comprising controlling the surface temperature of a squeeze roller in a developing tank when processing the photosensitive lithographic printing plate material using an automatic developing machine. 2. The method for processing a photosensitive lithographic printing plate material according to claim 1, wherein the temperature is maintained at 25 ° C. or higher. 3. A photosensitive lithographic printing plate material having a thickness of 1500 mm /
3. The method for processing a photosensitive lithographic printing plate material according to claim 1, wherein the material is transported at a speed of at least one minute.