JPH02250056A - Method and device for processing photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE:To prevent the generation of a developing defect and staining in printing by subjecting the surfaces of the photosensitive planographic printing plate to a processing of squeezing the surfaces with squeezing rollers, then spraying a developing soln. and rubbing the surfaces with brushes in the process when the plate is immersed in the soln. and is transported. CONSTITUTION:The photosensitive planographic printing plate 3 subjected to an image exposing is introduced by transporting rollers 4, 4', 5, 5', etc., into a processing liquid tank 1 and is transported therein. Guide plates 16 to 18 guide the front end of the plate 3 to a prescribed transporting route. The photosensitive layers of the non-image parts of the plate 3 transported in the processing liquid 2 swell and are squeezed by the squeezing rollers 8, 8', by which the parts corresponding to the photosensitive layers of the non-image parts are removed. The non-image parts are further removed by spraying of the developing soln. 2 by shower nozzles 10, 11 so that the photosensitive layers of the non-image parts are completely removed by the friction of the rolls 12, 13. The generation of the developing defect and the stains in printing is prevented.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a developing method and a developing device for photosensitive lithographic printing plates. The present invention relates to a processing method and a processing apparatus in an automatic processor that can produce a printing plate that is free from scratches.

[Background of the invention]

Conventionally, as a processing device for developing a photosensitive lithographic printing plate that has been imagewise exposed, a method has been known in which a processing liquid is sprayed onto the photosensitive layer surface of the photosensitive lithographic printing plate using a shower, and the processing liquid is circulated and reused. However, this method has drawbacks such as unstable development due to uneven spraying on the surface of the photosensitive layer, and severe deterioration of the developer due to absorption of charcoal gas in the air.

In order to solve these problems, Japanese Patent Laid-Open No. 57-64237 discloses a method in which a photosensitive lithographic printing plate is transported in a curved manner and immersed in a processing liquid for processing.

However, this method has the problem of significant deterioration of the developer because the spray is outside the solution, and an even bigger problem is that because it is an immersion process, the permeability of the developer into the photosensitive layer is poor, resulting in poor development. There is also a problem that the development process becomes unstable.

Furthermore, when processing a photosensitive lithographic printing plate having photosensitive layers on both sides of the support, a one-way shower system or a
In the method described in No. 37, it is difficult to maintain constant processability on the upper and lower sides of the photosensitive lithographic printing plate.

[Problem that the invention seeks to solve]

The present invention aims to solve the problems of the above-mentioned conventional techniques and to provide a method and a processing apparatus for developing a photosensitive lithographic printing plate, which are capable of stable and good development. The object of the present invention is to provide a development processing method and apparatus that can obtain a printing plate that does not cause development defects and does not cause stains during printing.

A second object of the present invention is to provide a development processing method and apparatus that can maintain stable developability at all times.

A third object of the present invention is to provide an economical developing processing method and apparatus that can minimize the amount of replenisher to be refilled. A fourth object of the present invention is to provide a development processing method and apparatus capable of uniformly developing both sides of a photosensitive lithographic printing plate having photosensitive surfaces on both sides.

[Structure of the invention]

The first to third objects of the present invention provide a method for processing a photosensitive lithographic printing plate, which includes a step of transporting the photosensitive lithographic printing plate while immersing it in a developer solution and carrying out a development process. A method for processing a photosensitive lithographic printing plate, including a process of squeezing the plate surface of the photosensitive lithographic printing plate with a squeezing roller, then spraying a developer onto the plate surface, and then rubbing the plate surface with a brush, and a dipping treatment. Achieved by a processing device having a conveying means for conveying the photosensitive planographic printing plate while being immersed in the processing liquid in a liquid tank, and a squeezing roller, a spray device, and a brush device in the conveyance direction in the submerged conveyance path by the conveying means. be done.

A fourth object of the present invention is to provide a processing method in which each of the processes of squeezing using the squeezing roller, spraying of a developer, and friction using a brush are performed on both upper and lower surfaces of a photosensitive planographic printing plate, and the squeezing roller; This is accomplished by a processing device in which a spray device and a brush device are placed opposite the photosensitive surface of the photosensitive lithographic printing plate.

Hereinafter, the present invention will be explained in detail based on examples.

FIG. 1 is a sectional view of a preferred example of a developing processing apparatus according to the present invention.

In FIG. 1, l is a processing liquid tank containing a processing liquid for photosensitive planographic printing plates, 2 is a processing liquid, 3 is a photosensitive planographic printing plate,
4.4', 5.5', 6,6', 7.7' are conveyance rollers for conveying the photosensitive planographic printing plate 3; 8.8
', 9.9' is a squeezing roller, 10% 11 is a shower nozzle which is a squirting device that sprays processing liquid onto the photosensitive planographic printing plate, and 12.13 is a rotating brush device which rubs the surface of the photosensitive planographic printing plate. A brush, 14.15 a press roller, and 16.17.18.19 a conveyance guide plate for guiding the photosensitive planographic printing plate 3 to a predetermined conveyance path. 20
2 is a pump for circulating the processing liquid 2 in the processing liquid tank and sending it to the shower nozzle 10.11, 21 is a heat exchanger for keeping the processing liquid at a constant temperature, and 22 is shower piping.

The peripheral wall surface of the squeezing roller 8.8'' having a squeezing function, the friction surface of the shower nozzle 10.11, and the rotating brush 12.13 are provided so as to be located in the processing liquid 2. Note that only one side is exposed to light. In an apparatus that processes only photosensitive lithographic printing plates having layers, one of the rotating brushes can be omitted.

In the figure, the photosensitive planographic printing plate 3 is conveyed from left to right.

In the present invention, it is preferable that the squeezing roller provided in the liquid be provided approximately at the center of the transport path in the processing liquid, specifically within 20% of the central portion of the length of the transport path in the processing liquid. The squeezing roller can be one commonly used in automatic developing machines for photosensitive planographic printing plates, but a preferable squeezing roller is, for example, a rubber having a hardness (JIS-A) of 30 to 60 and a recoil elasticity of 50% or more. Examples include those using materials.

Figure 2 is like Figure 1! -1 sectional view (partial sectional view), on the side of a pipe with a diameter of 10 to 20 mm, such as stainless steel or vinyl chloride resin, whose end is closed and the other end is connected to the pipe 22, in the length direction of the pipe, for example. It is a pipe that has holes with a diameter of 1 to 3+ am at intervals of 30 to 60 m.
The spray device is not limited to the above-mentioned tube, but may be any device that can uniformly spray the processing liquid onto the photosensitive planographic printing plate surface in the direction of the conveyance width. Tubes or the like having sides on each other can be used.

The angle of the spray jet against the plate surface of the photosensitive planographic printing plate is preferably 90°±45'', and the pressure of the jet jet against the plate surface is preferably 100 g/m'' or more.

As the brush device, one commonly used in automatic developing machines for photosensitive planographic printing plates can be used.

For example, as a brush roller as shown in Fig. 1, for example, nylon bristles with a diameter of 0.05 to 0.1 mm and a bristles length of 10 to 20 s+m and a diameter of about 50 mm are used. A rotating brush embedded in a vinyl resin pipe can be used.

The purpose of the squeezing roller in the present invention is to squeeze out the developer on the printing plate before it enters the printing plate. Since the squeezing effect differs depending on the hardness and elasticity of this roller, it is necessary to select the material, hardness, etc. of the roller. A preferable squeezing roller is one using a material having a recoil elasticity of 50% or more and a hardness (JIS-A) of 30 to 60. Such materials include, for example, silicone rubber (hardness 40, anti-bacterial elasticity 70%), isoprene rubber (hardness 50, anti-bacterial elasticity 80%), styrene rubber, butadiene rubber, chloroprene rubber, urethane rubber, urethane rubber, etc. There are propylene rubber, etc.

Further, the squeeze roller may have its both end shafts pressed against the printing plate using springs or the like.

3 and 4 show another embodiment of a brush device for rubbing the upper and lower surfaces of a photosensitive planographic printing plate. In the example shown in FIG. 3, two rotating brush rollers 32 are used. ．．
A photosensitive planographic printing plate is conveyed between 33.

In the example shown in FIG. 4, the photosensitive planographic printing plate 3 is conveyed between fixed brushes 42,43.

In the present invention, t is the point at which a certain point of the photosensitive planographic printing plate being transported is immersed in the developer, and t is the point at which the point is squeezed by a squeezing roller submerged in the liquid. , the point at which friction begins due to the brush device submerged in the liquid.

Assuming that, when the total development time is set in the range of 10 to 40 seconds, 1. #1. Appropriately, the time for is 2 to 25 seconds, and the time for jl to t is approximately 3 to 35 seconds. The developing solution may be sprayed in the shower at any time after it is squeezed by the squeezing roller in the solution and after it is rubbed by the brush device.

Next, the operation of the apparatus shown in FIG. 1 will be described.

The image-exposed photosensitive planographic printing plate is transported by a conveying roller 4.4'
, 5.5', etc., and transported into the processing liquid tank. At this time, the guide plates 16, 17, 18 guide the leading edge of the photosensitive planographic printing plate to a predetermined transport path.

The photosensitive layer in the non-image area of the photosensitive lithographic printing plate transported into the processing liquid swells, and is squeezed by a squeezing roller 8.8' to remove a considerable portion of the photosensitive layer in the non-image area.

Next, the non-image area is further removed by spraying a developer from the shower nozzle 10.11, and the photosensitive layer in the non-image area is completely removed by friction from the brush roll 12.13.

In the present invention, the photosensitive lithographic printing plate to be processed is 18th plate, which may be either positive type or negative type, and the processing liquid may also be a positive type mainly containing an alkali, a negative type containing an organic solvent, or a negative plate containing an organic solvent.
Any type of developer for both positive and negative use may be used.

Further, in addition to the processing device of the present invention, the automatic developing machine to which the present invention is applied may be provided with post-processing devices such as washing with water, processing with a rinsing liquid, and processing device using a gum solution. A replenishment system may be applied using circulating fluids.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 A JIS-1050 aluminum plate with a thickness of 0.24 mm was immersed in a 2% aqueous sodium hydroxide solution, degreased, and then electrochemically roughened in a dilute hydrochloric acid solution and thoroughly washed. After that, anodizing treatment is performed in a dilute sulfuric acid solution.
．． An oxide film of No. 09/Ten 8 was formed on the surface of the aluminum plate. After washing and drying the aluminum plate treated in this way, a photosensitive solution having the following composition was added to the dry weight of 2.2p/
m'' and dried to obtain a positive photosensitive planographic printing plate.The size of the photosensitive planographic printing plate was 1010O3.
There were two types: x800-s and 900+5 x 600-s.

(Photosensitive liquid) Pyrogallol-acetone resin naphthoquinone-1゜2-
Diazide (2)-5-sulfonic acid ester (Special Publication No. 43
(Synthesized by the method described in Example 1 of Publication No. 28403) ... 1 part by weight ■, p-talesol-formaldehyde resin... 2 parts by weight tert-butyleenol-formaldehyde resin
...0.3 parts by weight Oil Blue Agitation 603 (Product name: Orient Chemical Industry)
Co., Ltd., dye) ... 0.03 parts by weight Crystal Violet (B, A, S, F Co., Ltd., dye)
...0.03 parts by weight Ethylene diglycol heptanoethyl ether...20 parts by weight A large number of the thus obtained positive-working photosensitive lithographic printing plates were prepared, a transparent positive film was adhered to them, and they were heated with a 2-kilowatt metal halide lamp. Exposure was performed for 60 seconds from a distance of 70 cm.

The photosensitive lithographic printing plate was developed using the processing apparatus shown in FIG. In this device, the squeezing roller 8.8' has a diameter of 60 mm and the rubber is silicone rubber (hardness (J
The shower nozzle 1O111 has an inner diameter of 15 m and a thickness of 1 m.
A developing solution was sent to each of the shower nozzles 10 and 11 at a rate of 15 ff/min using an S+ tube with holes of 2 mm in diameter at a pitch of 40 mm in the length direction. rotating brush 1
As for 2.13, the length of nylon hair is 15m and the diameter is 6.
The length of the submerged conveyance path was reduced by 500 cm by using a material implanted in a 0 mm PVC pipe.

A developer having the following composition was used as the developer, the temperature of the developer was 27° C., and the immersion time in the developer was 20 seconds. 40 ff of developer was put into developer tank 1.

(Dear inventor, please add details regarding the specific conditions to the extent possible regarding the apparatus and method that are the characteristics of the present invention.) (Developer) Sodium silicate (11 industrial standard sodium silicate No. 3)...・15 parts by weight Sodium hydroxide 3.5 parts by weight Perex NB-L (surfactant manufactured by Kao Corporation)
...0.2 parts by weight water ...500
The photosensitive lithographic printing plate subjected to the weight part development process was washed with water and gummed for 10 seconds each. When the lithographic printing plate thus obtained was printed on an offset printing machine, a large number of good prints were obtained.

Furthermore, 100 of the photosensitive lithographic printing plates were continuously processed,
Similar printing was performed on the 100th plate, and as with the first plate, a good printed matter was obtained.

Example 2 A JIS-1050 aluminum plate with a thickness of 0 to 24 mm was immersed in a 20% sodium phosphate aqueous solution to degrease it, electrochemically roughened in a dilute hydrochloric acid solution, thoroughly washed, and anodized in a dilute sulfuric acid solution. Oxidation treatment was performed to form an oxide film of 1.59/l" on the surface of the aluminum plate. The aluminum plate thus treated was further immersed in an aqueous solution of sodium metasilicate for pore sealing treatment. , washing with water,
After drying, a photosensitive solution with the following composition was added to a dry weight of 1.89/
A negative type photosensitive lithographic printing plate was obtained by coating to a thickness of 11'' and drying.

The sizes of the photosensitive lithographic printing plates are the same as in Example 1: 1003mm x 8005m and 900mm x 600+
There were two types: m.

(Photosensitive liquid) 2-methoxy-4-hydroxy-5-benzoylbenzenesulfonate, a condensate of p-diazodiphenylamine and paraformaldehyde...1 part by weight 2-hydroxyethyl methacrylate copolymer (British Patent No. 1 .505,739 Specification, Example 1) ... 10 parts by weight Oil Puno, -$603 (trade name, Orient Chemical Industry (
Co., Ltd., dye) ... 0.3 parts by weight Ethylene glycol monomethyl ether ... 100 parts by weight A large number of negative photosensitive lithographic printing plates thus obtained were prepared, and a transparent negative film was adhered to them. Exposure was performed for 30 seconds from a distance of 70 cm using a Kilowatt metal halide lamp.

The same processing device as in Example 1 was used, and the developer tank 1 contained the following developer 40 for a negative photosensitive lithographic printing plate.
I put m.

(Developer) Ethylene glycol monophenyl ether...20 parts by weight Sodium carbonate-hydrate...3 parts by weight Sodium sulfite...3 parts by weight 3-methyl-3-methoxybutanol...74 parts by weight Water
...500 parts by weight of the above-exposed negative photosensitive lithographic printing plate was heated with a developer at a temperature of 27°C.
The film was developed by immersion in a developer for 20 seconds.

After the development process, the same process as in Example 1 was carried out], and when the obtained lithographic printing plate was printed using an offset printing machine, a large number of good prints were obtained.

Example 3 The positive in Example 1 was placed on the same aluminum support as the photosensitive lithographic printing plate, and a photosensitive solution having the following composition was applied at a dry weight of 2-2.
9/s'' and dried to obtain a positive photosensitive lithographic printing plate.

(Photosensitive liquid) Resorcinol-benzaldehyde resin 7-quinone-1
．． 2-Diazide (2)-5-sulfonic acid ester (described in Example 1 of JP-A No. 56-1044)...lt quantity Cresol phenol-formaldehyde resin...3 parts by weight tart Naphthoquinone-1,2-diazide(2)-5-sulfonic acid ester of -butylphenol-benzaldehyde resin (Example 1 of JP-A-60-31188)
)...0.1 part by weight Crystal violet (manufactured by B, A, S, F companies, dye)
...0.03 parts by weight Victoria Pure Blue BOH (trade name, manufactured by Hodogaya Chemical Co., Ltd., dye) ...0.02 parts by weight Ethylene glycol monomethyl ether...20 parts by weight Thus obtained A large number of positive photosensitive lithographic printing plates were prepared, a transparent positive film was adhered thereto, and exposure was performed for 50 seconds from a distance of 70 cm using a 2 kilowatt metal halide lamp.

On the other hand, a negative photosensitive lithographic printing plate was prepared as follows. A photosensitive solution having the following composition was placed on the same aluminum support as the negative photosensitive lithographic printing plate in Example 3 at a dry weight of 1
．． It was coated to give a ratio of 89/11'' and dried to obtain a negative photosensitive lithographic printing plate.

(Photosensitive liquid) Hexafluorophosphate of a condensate of p-diazodiphenylamine and paraformaldehyde...1 part by weight N-(4-hydroxyphenyl)metalacrylamide copolymer (implementation of Japanese Patent Publication No. 57-43890) (Those described in Example 1) ...10 parts by weight Victoria Pure Blue BOH (trade name, Hodogaya Chemical Industry Co., Ltd.)
1 part by weight of ethylene glycol monomethyl ether (100 parts by weight) The resulting negative was prepared by preparing a large number of photosensitive lithographic printing plates and adhering transparent negative film to a 2-kilowatt. Exposure was performed for 30 seconds from a distance of 70 cm using a metal halide lamp.

Next, in the same automatic developing machine as in Example 1, the exposed positive-working photosensitive lithographic printing plate and the negative-working photosensitive lithographic printing plate were alternately developed at 27° C. for 20 seconds.

The developer used was a concentrated developer having the following composition diluted six times with water.

(Concentrated developing composition) Water: 426 parts by weight β-anilinoethanol: 25 parts by weight R-propylene gellicol: 25 parts by weight 2-hydroxy-3-naphthoic acid: 50
Part by weight p-tert-butylbenzoic acid...
100 parts by weight potassium hydroxide...1
25 parts by weight Nonionic surfactant (Emulgen 147, manufactured by Kao Corporation) 2.5 parts by weight Potassium silicate A 175 parts Potassium sulfite 50 parts By weight When each of the lithographic printing plates obtained from the photosensitive lithographic printing plate and the negative-type photosensitive lithographic printing plate was printed using an offset printing machine, a large number of good prints were obtained without any staining. Furthermore, when 50 sheets each of the negative and positive photosensitive lithographic printing plates were successively mixed and printed in the same manner, both positive and negative lithographic printing resulted in the same result as the first plate. Good printed matter was obtained.

Example 4 The same procedure as in Example 1 was carried out except that the plate to be processed was processed with its photosensitive surface facing down. As in Example 1, a large number of good printed materials were obtained.

Example 5 Example 2 was carried out in the same manner as in Example 2, except that the plate to be processed was processed with its photosensitive surface facing down. As in Example 2, a large number of good printed materials were obtained.

Comparative Example 1 Example 2 except that the brush was removed in Example 2
When I did the same thing as above, the printing was smudged.

Comparative Example 2 Example 1 except that the brush was removed in Example 1
When the process was carried out in the same manner as above, there was no staining, but when comparing the number of stages of the step wedge, it can be seen that the developability has deteriorated.

Each step in Examples and Comparative Examples [Effects of the Invention] According to the present invention, the developability in the immersion development method is improved compared to the conventional technology. Therefore, the relationship between poor development and staining during printing for the same transport length in immersion development is improved, and the development processing time can be shortened. Furthermore, according to the present invention, both sides of a photosensitive lithographic printing plate having photosensitive layers on both sides can be developed to the same level.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an example of the device of the present invention, FIG. 2 is a cross-sectional view taken along line I-1 showing an example of the essential parts of the shower nozzle of the same device, and FIGS. 3 and 4 are different views of the brush device. It is a sectional view showing an example. 1: Processing liquid tank 2: Processing liquid 3: Photosensitive planographic printing plates 4.4', 5.5', 6.6', 7.7': Conveyance rollers 8, 8', 9.9', 38. 38″, 48
．． 48″: Squeezing roller 1O111, 30, 31, 40,
41: Shower nozzle 12.13.32.33: Rotating brush 14.15: Presser roller

Claims (4)

[Claims] (1) In a method for processing a photosensitive lithographic printing plate, which includes a step of conveying the photosensitive lithographic printing plate while immersing it in a developer and developing it, the plate surface of the photosensitive lithographic printing plate is A method for processing a photosensitive lithographic printing plate, comprising the steps of: squeezing with a squeezing roller, then spraying a developer, and then rubbing with a brush. (2) The processing method according to claim 1, wherein each of the processes of squeezing with the squeezing roller, spraying of the developer, and friction with a brush are performed on both the upper and lower surfaces of the photosensitive planographic printing plate. (3) A conveyance means for immersing and conveying the photosensitive planographic printing plate in the treatment liquid in the treatment liquid tank, and a submerged conveyance path by the conveyance means, including a squeezing roller, a spray device, and a brush device in order in the conveyance direction. A processing device for a photosensitive lithographic printing plate, characterized in that: (4) The processing apparatus according to claim (3), wherein the squeezing roller, the spray device, and the submerged brush device of the submerged conveyance path are devices disposed opposite to the photosensitive surface of the photosensitive planographic printing plate. .