JPH0950134A - Automatic ps plate developing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a good planographic printing plate free from scratches at least while a PS plate can be satisfactorily developed with developer in a developing tank by sprinkling liquid, which is not yet used for a developing processing, on inlet rollers. SOLUTION: The image-exposed PS plate 1 is fed into the developing tank 3 by the inlet rollers 2 so as to execute the developing processing with developer. The developer is not directly supplied to the developing tank 3 by a rise liquid supply tube 3N and the dilution water of replenisher is not directly replenished to the tank 3 by a dilution tube 3L, but at first, the developer and the dilution water are sprinkled on the inlet rollers 2 through respective nozzles. And, after the developer and the dilution water used for cleaning the inlet rollers 2 flow down beneath the inlet rollers 2, the developer and the dilution water flow into the developing tank 3. Thus, the inlet rollers 2 are washed with the liquid which is not yet used for the developing processing and whose pH is equal to or below the pH of the liquid of the developer at the starting time, or the replenisher so as to be nearly proportional to the number of the fed PS plates 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a negative type or positive type P
The present invention relates to an automatic developing machine for developing an image-exposed product of an S plate, that is, a plate material coated with a photocurable or light-soluble type photosensitive resin layer, and in particular, a PS tank after the exposure is developed by an entrance roller in a developing tank. The present invention relates to a PS plate automatic developing machine which is received in a developing tank, is developed with a developing solution in a developing tank equipped with a replenishing means, and is sent out from the developing tank.

[0002]

2. Description of the Related Art The PS plate automatic developing machine as described above is known from JP-A-5-81842 and JP-A-6-236041. Such a conventional PS plate automatic developing machine was damaged even though the developer in the developing tank was replenished with a replenisher to maintain sufficient performance to develop a sufficiently large number of PS plates. There was a problem that a lithographic printing plate could be obtained.

[0003]

DISCLOSURE OF THE INVENTION The present invention produces an automatic developing machine which does not have the above-mentioned problems, that is, a good planographic printing plate having no scratches at least while the developing solution in the developing tank can develop the PS plate well. The purpose is to provide an automatic PS plate developing machine.

[0004]

As a result of pursuing the causes of the above-mentioned problems, the present inventors have found that dust adhering to the PS plate fed into the developing tank or developer splashed out of the developing tank enters the entrance roller. It was clarified that the cause was that it adhered, dried and solidified, and became sludge to damage the plate.

The present invention has been made based on the above-mentioned findings of the present inventors. In the developing tank provided with a replenisher replenishing means, the PS plate after exposure is received by the entrance roller into the developing tank. In the PS plate automatic developing machine which develops with the developing solution and sends it from the developing tank, p of the rising solution of the developing solution is used.
A liquid having a pH not higher than H or a pH not higher than that of the replenisher, which has not been used in the development process, is poured onto the entrance roller, and the above-mentioned object is achieved by this feature.

[0006]

That is, in the PS plate automatic developing machine of the present invention, an unused liquid is poured onto the inlet roller for the development processing at a pH lower than the pH of the rising liquid of the developing liquid or the replenishing liquid. Dust from the plate and splashing developer from the developing tank are also washed away so that they do not adhere to the entrance roller and solidify, so the surface of the entrance roller is always kept clean and the PS plate is kept clean. It is possible to produce a well-developed lithographic printing plate that is well developed as long as the developer maintains the ability to develop the PS plate satisfactorily without scratching. If the liquid that has not been used for processing, that is, the pouring liquid, uses the rising water of the developing liquid or the dilution water used to dilute the replenishing liquid, the pouring liquid can be used later as the diluting water of the developing liquid or the replenishing liquid. It is not necessary most to increase the production cost of the lithographic printing plate.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic cross-sectional view showing an example of a PS plate automatic developing machine according to the present invention. In this PS plate automatic developing machine, the image-exposed PS plate 1 is developed by a pair of inlet rollers 2 in a developing tank. It is sent into the inside of 3 and processed by the developing solution.
Next, it is sent to the rinsing tank 4 to rinse away the developing solution adhered by the rinsing solution and the photosensitive resin dissolved therein, and then is sent to the gumming tank 5 to be coated with the gum solution, and then the drying chamber. For example, Japanese Patent Application Laid-Open No. 6-23 discloses that the lithographic printing plate is sent after being fed to the No. 6 and dried.
No. 6041, JP-A-6-35174, and Japanese Utility Model Laid-Open No. 5-81.
842, JP-A-3-59666, JP-A-62-28
This is the same as in the conventional PS plate automatic developing machine described in JP-A-8845 and JP-A-61-162049.

That is, the PS plate 1 is, for example, paper, a plastic sheet, a metal sheet, a composite sheet obtained by laminating a plastic on a paper or a metal on a plastic sheet, etc., preferably one surface is roughened and anodized films are provided on both surfaces. Using aluminum or an aluminum alloy sheet as a support, a photosensitive diazo compound, an azide compound, a compound having an ethylenically unsaturated double bond, which changes into a curable type or a soluble type by exposure on one surface side of the support, an acid Negative type or positive type PS plate on which a layer such as an epoxy compound that polymerizes with a catalyst, a silyl ether polymer that decomposes with an acid, or a combination of a compound having a C—O—C group and a photoacid generator is formed. May be The image exposure of the PS plate 1 is performed by a light rich in actinic rays through a transparent original image having a line image and 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. Done.

As the developing solution in the developing tank 3, an aqueous alkaline developing solution containing an alkali metal silicate is used. The alkali metal silicate is [SiO ₂ ] / [M] (wherein [SiO ₂ ]
Indicates the molar concentration of SiO ₂ , and [M] indicates the molar concentration of alkali metal. Is in the range of 0.5 to 1.2, and potassium silicate or sodium silicate is preferable, and potassium silicate is particularly preferable. It is preferable to add this so that the SiO ₂ concentration in the developer is 0.5 to 6% by weight. It is an alkaline aqueous solution in which other alkaline agents such as sodium hydroxide, potassium hydroxide, sodium phosphate tribasic, sodium phosphate dibasic, sodium carbonate, and potassium carbonate are added and dissolved as necessary, and the pH (25 ℃, the same below) is 12 or more 1
An alkaline aqueous solution of 3.5 or less is preferably used as the developing solution.

As a replenisher for replenishing the developing solution in order to recover the performance deterioration due to the use of the developing solution, an alkaline aqueous solution having an alkaline agent concentration containing a silicate of an alkali metal higher than that of the developing solution is used. [SiO ₂ ] / [M] of the alkali metal silicate is in the range of 0.25 to 0.8, and potassium silicate or sodium silicate is preferable, and potassium silicate is particularly preferable. This addition amount is such that the SiO ₂ concentration in the replenisher is 0.5 to 6% by weight
Is preferably added so that If necessary, potassium hydroxide, sodium hydroxide, lithium hydroxide, sodium phosphate tribasic, sodium phosphate dibasic, potassium phosphate tribasic, potassium phosphate dibasic, ammonium phosphate tribasic, phosphate dibasic Inorganic alkali agents such as ammonium acidate, sodium metasilicate, sodium bicarbonate, sodium carbonate, potassium carbonate, ammonium carbonate, and organic alkali agents such as mono-, di- or triethanolamine, tetraalkylammonium hydroxide, and organic ammonium silicate are used. An alkaline aqueous solution which is added and dissolved in the range of 0.05 to 20% by weight and whose pH is higher than the pH of the developing solution, preferably 0.3 or higher than the pH of the developing solution is used.

If necessary, various kinds of surfactants and organic solvents may be added to the above-mentioned developing solution and replenishing solution in an amount of 0.01 or less for the purpose of promoting or suppressing the developing property, dispersing the development residue or enhancing the ink affinity. It may be added in the range of 10 wt%, but when an alkaline aqueous solution having a pH or an alkali metal silicate concentration higher than that of the developer is used as the replenisher, most of the pH is increased when the replenisher is replenished with the developer. Since the dilution water is also replenished so that the concentration of the developer is close to that of the developing solution, a surfactant or an organic solvent may be added to the dilution water. In addition, additives such as an antifoaming agent and a water softener may be added to the developer and the replenisher.

A rinse liquid containing water, a surfactant or the like is used as a rinse liquid in the rinsing tank 4, and a gum liquid containing gum arabic or a starch derivative is used as a gum liquid in the gumming tank 5.

In the developing tank 3 into which the PS plate 1 is fed by the entrance roller 2, there is a conveying roller 3A which receives and conveys the PS plate 1, and a position opposite to the conveying roller 3A. A rotating brush 3B for removing a portion dissolved by the developing solution, and a pair of squeezing rollers 3C for preventing the developing solution from passing together with the PS plate 1 and sending the PS plate 1 from the developing tank 3 to the rinsing tank 4. , A valve that opens and closes based on information detected by a developer level sensor (not shown) of the developer tank 3 to maintain the developer level in the developer tank 3 at a predetermined level, and a developer in the developer tank 3 shared or in parallel therewith. A developing tank drain pipe 3D for discharging the developing solution from the developing tank 3 provided with a valve for withdrawing, a developing solution tank 3E for receiving and storing the developing solution from the developing tank drain tube 3D, and an inlet roller 2 Developed 3 of the PS plate 1 by sending a developing solution in the developing tank 3E pump multiplying poured from the nozzle developer liquid pouring tube 3
F, a developer tank drain pipe 3G equipped with a valve for draining the developer tank 3E, a waste tank 3H for receiving and storing the developer solution from the developer tank drain tube 3G, and a replenisher. A tank 3I and a pump which is driven based on information such as the number of PS plates 1 fed into the developing tank 3, cumulative feed direction length, area, plate surface impedance, or detection information such as electric conductivity of the developing solution and pH Driven based on the information that the replenisher pipe 3J for replenishing the developer tank 3I with the replenisher tank 3I, the dilution water tank 3K, and the pH sensor (not shown) detect the pH of the developer tank in the developer tank 3 or the developer tank 3E. Or a rising pipe tank 3L and a diluting pipe 3L for supplying the diluting water in the diluting water tank 3K to the developing tank 3 by providing a pump that interlocks with the pump of the replenishing pipe 3J.
Equipped with a pump to drive the M and PS plate automatic developing machines at the time of starting up
And a rising liquid supply pipe 3N for supplying the liquid.

The PS plate automatic developing machine of the illustrated example does not directly supply the developing solution to the developing tank 3 through the rising liquid supply pipe 3N and the dilution water to the developing tank 3 through the dilution pipe 3L. First, the developing solution and the diluting water are poured into the inlet roller 2 by the nozzles respectively, and the developing solution and the diluting water that wash the inlet roller 2 flow down below the inlet roller 2 and then flow into the developing tank 3. As a result, the entrance roller 2 is cleaned with the rising liquid of the developer having excellent cleaning performance that does not dissolve the unused photosensitive resin in the development when the feeding of the PS plate 1 is started, and the surface is cleaned. Further, since the PS plate 1 has been fed in, the unused photosensitive resin has not been dissolved in the development.
Since H is washed with dilution water having a pH equal to or lower than the pH of the rising liquid or the replenishing liquid so as to be approximately proportional to the number of fed PS plates 1,
No dust from the PS plate 1 or splashing developer from the developing tank 3 adheres to the surface and solidifies, and the surface of the entrance roller 2 is always kept clean and the PS plate 1 may be damaged. Even if the liquid for cleaning the inlet roller 2 adheres to the PS plate 1, it does not invade the PS plate 1 and cause defective development. As long as the developing performance is maintained, the developing tank 3 develops well.

A pair of receiving rollers 4A for receiving and sending the PS plate 1 sent from the developing tank 3 to the rinsing tank 4.
And a guide member 4B that receives and guides the PS plate 1 sent by the receiving roller 4A, and occupies a position facing the guide member 4B.
Rotating brush 4C for removing the dissolved photosensitive resin by the developer not removed from the surface of S plate 1, and PS plate 1
A pair of squeezing rollers 4 that prevent the rinsing liquid from passing therethrough and send the PS plate 1 from the rinsing tank 4 to the gumming tank 5.
D, a rinsing liquid tank 4E for draining and storing the rinsing liquid from the bottom of the rinsing tank 4, and a pump for feeding the rinsing liquid of the rinsing liquid tank 4E to receive the rinsing liquid from the nozzle, and feed roller 4A and guide member 4
Rinse injection pipe 4F that is poured onto the PS plate 1 that is sent to and from B
Are provided.

A pair of receiving rollers 5 for receiving and sending the PS plate 1 sent from the rinsing tank 4 to the gumming tank 5.
A, a pair of squeezing rollers 5B that prevent the gum solution from passing together with the PS plate 1 and send the PS plate 1 from the gumming tank 5 to the drying tank 6, and the gum solution from the bottom of the gumming tank 5. 5C of gum liquid tank for extracting and storing the gum liquid, and a pump for sending the gum liquid of the gum liquid tank 5C to receive the gum liquid from the nozzle and pour it onto the PS plate 1 sent between the feeding roller 5A and the squeezing roller 5B. 5D and are provided.

The PS plate 1 sent out from the gumming tank 5 is sent into the drying chamber 6 via the transition roller 56, and in the drying chamber 6, hot air is blown from the air nozzles 6A and 6B at the upper and lower sides of the transport path to both upper and lower surfaces. Is sent by a pair of conveying rollers 6C, and hot air is blown onto both upper and lower surfaces from air nozzles 6D and 6E above and below the conveying path.
It is discharged to the outside of the machine by F and used as a lithographic printing plate that is well developed without scratches.

Further particularly preferred examples will be shown below,
The present invention is not limited to the following examples as described above.

Example 1 Using a PS plate automatic developing machine as shown in FIG.
Processes both the positive PS plate and the negative PS plate shown below.

Positive PS plate: JIS with a thickness of 0.24 mm
A 1050 aluminum sheet is immersed in a 2% aqueous solution of sodium hydroxide for degreasing treatment, electrochemically roughened in a dilute nitric acid solution, washed well, and then anodized in a dilute sulfuric acid solution. An oxide film of 0.5 g / m ² is formed on the roughened surface. This aluminum sheet is washed with water and dried, and a photosensitive composition coating solution having the following composition is dried at a weight of 2.0 g.
/ M ² and then dried to obtain a PS plate.

(Photosensitive Composition Coating Liquid) Naphtoquinone- (1,2) -diazide- (2) -5-Sulfonyl Chloride Ester Compound with Pyrogallol-Acetone Resin 2.7 parts by weight Phenol, m-, p - copolycondensation resin of cresol mixture and formaldehyde (during synthesis of phenol, m- cresol and p- cresol each molar ratio of 10:54:36, a weight-average molecular weight M _W = 5500) 7.0 parts by weight of p An ester compound of a novolak resin synthesized from -tert-octylphenol and formaldehyde and naphthoquinone- (1,2) -diazide (2) -5-sulfonic acid chloride (condensation rate: 50 mol%, M _W = 1700). 1 part by weight PEG # 2000 0.1 part by weight Naphthoquinone- (1,2) -diazide- (2) -4- Rufonic acid chloride 0.05 parts by weight Victoria Pure Blue BOLL (manufactured by Hodogaya Chemical Co., Ltd.) 0.08 parts by weight Ethyl cellosolve 80 parts by weight Methyl cellosolve 20 parts by weight Negative PS plate: same as the positive type aluminum sheet Degrease with a 3% aqueous sodium hydroxide solution and add 25
80 A / dm ² in 11.5 g / liter hydrochloric acid solution at ℃
Electrolytic etching was performed at a current density of 11 seconds for 11 seconds, followed by washing with water and anodization in a 30% sulfuric acid solution at 30 ° C. under the conditions of 11.5 A / dm ² for 15 seconds. Then, it was treated with a 1% sodium metasilicate aqueous solution at 85 ° C. for 30 seconds, washed with water and dried to obtain a support. The photosensitive composition coating liquid of the following composition filtered on this support had a dry weight of 1.5 g / m 2 by a bar coater.
^It was applied so as to have a thickness of ² and dried to obtain a PS plate.

(Photosensitive composition coating liquid) trimethylolpropane triacrylate 0.3 g Poly (N- (4-hydroxyphenyl) methacrylamide / acrylonitrile / methylmethacrylate / methacrylic acid) copolymer Molar ratio 25/25 / 42/8 copolymer (Mw = 42000) 0.3 g Nippon Kayaku Co., Ltd. DETX (the following structure) 0.03 g

[0024]

Embedded image

EPA (the following structure) manufactured by Nippon Kayaku Co., Ltd. 0.03 g

[0026]

Embedded image

Diazo Resin-1 0.024 g Victoria Blue BOH (trade name, manufactured by Hodogaya Chemical Co., Ltd.) 0.012 g JULIMER AC-10L (trade name, manufactured by Nippon Pure Chemical Industries, Ltd.) 0.012 g Methyl Cellsolve 8 0.0 g The above-mentioned diazo resin-1 is obtained as follows.

3.5 g (25 mmol) of p-hydroxybenzoic acid and p-diazodiphenylamine sulfate 2
1.75 g (75 mmol) are dissolved in 90 g concentrated sulfuric acid under ice cooling. To this solution 2.7 g (90 mmol)
Paraformaldehyde slowly, reaction temperature 10 ℃
Add not to exceed. The reaction solution is stirred for 2 hours and then added dropwise to 1 liter of ethanol, and the generated precipitate is separated by filtration and washed with ethanol. 200m of washed precipitate
It is dissolved in 1 l of pure water, and an aqueous solution in which 10.5 g of zinc chloride is dissolved is added. The generated precipitate is filtered, washed with ethanol, and then dissolved in 300 ml of pure water. 1 in this solution
An aqueous solution of 3.7 g ammonium hexafluorophosphate is added. The resulting precipitate was filtered off, washed with water and ethanol, and then dried at 25 ° C for one day to diazo resin-
Get one. The weight average molecular weight of this diazo resin-1 measured by gel permeation chromatography (hereinafter abbreviated as GPC) was about 2300.

In the above-mentioned positive PS plate and negative PS plate,
A 2 kW metal halide lamp was adhered by closely adhering a manuscript film having a corresponding halftone dot pattern and a step tablet for sensitivity measurement (Eastman Kodak Co., No. 2, 21-step gray scale with a density difference of 0.15). A light source was exposed under a condition of 8.0 mW / cm ² from a distance of 70 cm for 60 seconds to obtain a sample to be developed.

A developing solution and a replenishing solution having the following compositions are prepared, and the rising solution of the developing solution is 10 from the start of feeding the PS plate 1.
At a pace of 0 ml / m ² , it is poured onto the entrance roller 2 and the PS plate 1 sent by it, and flows into the developing tank 3, and the developing solution in the developing tank 3 is also sent to the developing tank 3 at a pace of 100 ml / m ^2. It is circulated so as to be poured over the PS plate 1, and the replenisher is replenished to the developer in the developing tank 3 under the replenishment conditions described below. As a result, each sample is 30 ℃
Development is performed for 12 seconds. The order of treatment is positive PS plate and negative PS plate, one for each Kikuzen size per day.
50 editions and 50 editions total 200 editions for 2 weeks, total edition 24
It is assumed that the 00 plate processing is performed, and the detailed processing order is random.

(Developer) A potassium silicate (SiO ₂ : 26% by weight, K ₂ O: 13% by weight) 100 parts by weight Potassium hydroxide 19 parts by weight Water 1200 parts by weight (replenisher) A potassium silicate (SiO ₂ : 26% by weight, K ₂ O: 13% by weight) 100 parts by weight Potassium hydroxide 22 parts by weight Water 40 parts by weight (replenishment conditions) Diluting water 600 against replenisher 162 parts by weight
Replenishment at a rate of parts by weight, processing replenishment by this diluted replenishment amount: 70 ml / m ² , replenishment over time: 240 ml / h, daily replenishment (replenishment during the non-operating period of the automatic processor): 200 m
1 / h. The dilution water is replenished by pouring it into the entrance roller 2 as described above.

Water is used as the rinsing liquid, and the gum liquid is disclosed in
A gum solution under conventionally known conditions as described in Japanese Patent No. 314054 is used.

Under the above conditions, a lithographic printing plate of 2400 plates was obtained in 2 weeks, but no scratches were found and good images could be printed.

Example 2 A lithographic printing plate was obtained under the same conditions as in Example 1 except that the rising liquid of the developing solution was supplied to the developing tank 3 before the feeding of the PS plate 1. Each of the obtained lithographic printing plates was free from scratches and could print good images.

COMPARATIVE EXAMPLE 1 The PS plate automatic developing machine shown in FIG. 1 has a dilution pipe 3L from a dilution water tank 3K and a rising liquid supply pipe 3N from a rising liquid tank 3M directly into the developing tank 3, respectively. A lithographic printing plate was similarly obtained under the same processing conditions as in Example 2 except that the lithographic printing plate was supplied. The planographic printing plates obtained were one in the first 800 plates, two in the next 800 plates, and 5 in the last 800 plates.
A scratched version was found.

[0036]

According to the PS plate automatic processor of the present invention, the surface of the entrance roller is kept clean without being scratched and the PS plate is not scratched, and the PS plate is well developed by the developing solution. As long as the obtained performance is maintained, a well-developed scratch-free lithographic printing plate can be produced. Furthermore, by using the dilution water used for diluting the rising liquid of the developer or the replenisher as the pour liquid poured on the entrance roller, the pour liquid can be used later as the diluting water for the developer and the replenisher.
The production cost of the planographic printing plate can be hardly increased.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a configuration showing an example of a PS plate automatic developing machine of the present invention.

[Explanation of symbols]

 1 PS plate 2 Inlet roller 3 Development tank 3B, 4C Rotating brush 3C, 4D, 5B Squeezing roller 3D Development tank drain pipe 3E Developer tank 3F Development injection pipe 3I Replenishment liquid tank 3J Replenishment pipe 3K Dilution water tank 3L Dilution pipe 3M Rising liquid tank 3N Rising liquid supply pipe 4 Rinsing tank 5 Guming tank 56 Crossover roller 6 Drying room

Claims (3)

[Claims] 1. An automatic PS plate developing machine which receives a PS plate after exposure into a developing tank with an entrance roller, develops the developing solution with the developing solution in a developing tank equipped with a replenishing solution replenishing means, and sends out from the developing tank. Is the pH of the developing solution rising or lower,
Alternatively, a PS plate automatic developing machine is characterized in that a liquid having a pH not higher than that of the replenishing liquid and not used in the developing process is poured onto the inlet roller. 2. The PS plate automatic developing machine according to claim 1, wherein the unused liquid is the same as the rising liquid. 3. The PS plate automatic developing machine according to claim 1, wherein the unused liquid is dilution water used for diluting the replenisher.