JPH1152585A - Production of aluminum planographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an aluminum planographic printing plate having improved ink receptivity and water retentivity by using a silver complex salt diffusion transfer process and further having improved gelatin removability. SOLUTION: In this method, a planographic printing plate material having physical developing nuclei between an aluminum substrate and a silver halide emulsion layer is exposed and then processed with at least a developer and a washing liq. in order to produce the objective planorgaphic printing plate. The developer and/or the washing liq. contains a nonionic compd. having at least one of oxyalkylene and glycerol units and a structural part which is more hydrophobic than these units.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for making a lithographic printing plate utilizing a silver complex salt diffusion transfer method using an aluminum plate as a support.

[0002]

2. Description of the Related Art A planographic printing plate using a silver complex salt diffusion transfer method (DTR method) is described in "Photographic Silver Halide," published by Focal Press, London New York (1972), by Andrelot and Edith Weide. Some examples are described in "Diffusion Processes", pp. 101-130.

There are two types of planographic printing plates using the DTR method: a two-sheet type in which a transfer material (photosensitive material) and an image receiving material are separated, or a mono-sheet type in which they are provided on a single support. Are known. The two-sheet type lithographic printing plate is described in detail in JP-A-57-158844. For the mono sheet type, see JP-B-48-30562 and JP-B-51-1576.
No. 5, JP-A-51-111103 and JP-A-52-1501.
It is described in detail in each gazette such as No. 05.

A mono-sheet type lithographic printing plate utilizing a silver complex salt diffusion transfer method using an aluminum plate as a support (hereinafter referred to as an aluminum lithographic printing plate) is disclosed in
No. 118244, No. 57-158844, No. 63-2
60491, JP-A-3-116151, 4-28
No. 2,295, U.S. Pat. Nos. 4,567,131, 5,196,290, and 5,427,889.

[0005] The aluminum lithographic printing plate has a structure in which a physical development nucleus is supported on a roughened and anodized aluminum support, and a silver halide emulsion layer is further provided thereon. The general method of making a lithographic printing plate is
After exposure, development, washing (removal of the silver halide emulsion layer), and finishing are performed.

More specifically, a metal silver image portion is formed on a physical development nucleus by a development process, and a silver halide emulsion layer is removed by a subsequent washing process to form a metal silver image portion (hereinafter referred to as silver) on an aluminum support. Image portion) is exposed. At the same time, the anodized aluminum surface itself is exposed as a non-image area.

The exposed silver image area and the non-image area are coated with a finishing solution containing a protective colloid such as gum arabic, dextrin, carboxymethylcellulose, polystyrene sulfonic acid and the like for protection. A so-called gumming process is performed. This finishing solution is also called a fixing solution or a finishing solution, and is also known to contain a compound that makes the silver image portion lipophilic (hereinafter, referred to as a lipophilic agent).

One of the serious problems in the method of making an aluminum lithographic printing plate is the problem of removing gelatin from a silver halide emulsion layer. In the aluminum lithographic printing plate, the removal of the silver halide emulsion layer is a very important step for completely exposing the silver image portion and the non-image portion composed of the aluminum surface itself. In particular, the silver image portion receiving the ink needs to have strong lipophilicity, and it is necessary to completely remove substances that inhibit lipophilicity such as gelatin.

The washing process is generally carried out by spraying a washing solution at 25 to 35 ° C. by a jet method to peel and remove the emulsion layer, or by spraying the washing solution and peeling the emulsion layer with a scrub roller. I have. However,
It is difficult to completely remove the emulsion layer by such a physical stripping and removing method, and as a result, there is a problem that water retention and ink acceptability are low.

On the other hand, the washing liquid is circulated through a filtration filter to collect the components of the emulsion layer eluted or dispersed in the washing liquid, for example, gelatin and silver ions, and to reuse the washing liquid. ing. Therefore, it is preferable to efficiently filter the components of the emulsion layer eluted or dispersed in the washing solution for the reuse of the washing solution, but at present it is not sufficiently collected by filtration, and the washing solution is contaminated. There was a problem. The gelatin dissolved in the washing solution easily rots and deteriorates the working environment. Furthermore, if the amount of gelatin dissolved in the washing solution increases due to the running process, the gelatin in the washing solution re-adheres to the aluminum surface and the silver image area, and the ink receptivity and the water retention deteriorate.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a method of making an aluminum lithographic printing plate having excellent ink acceptability and water retention. Another object of the present invention is to provide a plate making method capable of efficiently filtering emulsion gelatin components eluted or dispersed in a washing solution. Still another object is to provide a plate making method that maintains the performance of a washing liquid in running processing and maintains ink acceptability and water retention.

[0012]

SUMMARY OF THE INVENTION The object of the present invention is to treat with a nonionic compound having at least one of an oxyethylene unit and a glycerol unit and having a structural part more hydrophobic than them. And a plate making method.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS That is, the present invention comprises, after exposing a lithographic printing plate having a physical development nucleus between an aluminum support and a silver halide emulsion layer, having at least one of an oxyethylene unit and a glycerol unit, Further, the treatment is carried out with a developing solution and / or a washing solution containing a nonionic compound having a structural portion more hydrophobic than those units.

A nonionic compound having at least one of an oxyethylene unit (OE) and a glycerol unit (GO) and a structural part more hydrophobic than OE or GO (hereinafter abbreviated as OE-OP compound) is developed. It is contained in the liquid and / or the washing liquid, but may be contained in both. By including the OE-OP compound in the washing liquid, the gelatin separated by a scrub roller or the like is agglomerated to facilitate removal. When the OE-OP compound is contained in the developing solution, the OE-OP compound is carried into the next washing solution in a state of being contained in the emulsion layer and the like, and also the gelatin is easily aggregated and easily removed. The silver halide emulsion layer may be removed between the developing tank and the washing tank.

The gelatin / silver halide emulsion layer is not substantially hardened and can be removed relatively easily. However, it is possible to completely remove a small amount of gelatin adhering to an aluminum surface having micro unevenness or a transferred silver image. It was very difficult to wash and remove. According to the present invention, the OE-OP compound exhibits an aggregating action of gelatin in the processing solution, and can not only satisfactorily separate gelatin from the processing solution but also remove even a trace amount of gelatin from the aluminum surface and the transferred silver image area. In addition, ink receptivity and water retention are improved.

The presence of the OE-OP compound in the washing solution improves the efficiency of the filtration and recovery of the gelatin dissolved in the washing solution, and can prevent the decay of the gelatin due to the running process. Furthermore, if the amount of gelatin eluted in the washing solution is reduced, re-adhesion to the aluminum surface and the silver image area does not occur, so that it is possible to prevent a decrease in ink receptivity and water retention (stain resistance) in running processing. .

Hereinafter, the present invention will be described in more detail. In the OE-OP compound used in the present invention, the number of OE units or GO units may be one, but preferably two or more polyoxyethylene (POE) or two or more polyglycerol (PGO). OE and GO
The more hydrophobic structural part is preferably (poly) oxypropylene (POP), but may be an alkyl group, an aryl group, an alkoxycarbonyl group, an alkenyl group or the like, or may have a complex structure thereof. May be. Specifically, a block polymer of a POE unit and a POP unit, a compound in which an alkyl group, an aryl group, or an alkenyl group is bonded to the block polymer, an ester compound of the block polymer, and a POE unit or PG
Examples include compounds in which an alkyl group, an aryl group, or an alkenyl group is bonded to an O unit, and ester compounds of a POE unit or a PGO unit. The alkyl group, the aryl group, and the alkenyl group include those having an ether bond in the POE unit and, in some cases, the POP unit.

The alkyl group is preferably a straight-chain alkyl group having 3 to 30 carbon atoms, preferably 4 to 20 carbon atoms, and may have an unsaturated bond. The aryl group is phenyl, naphthyl, or the like, and may have a substituent such as an alkyl group. The alkenyl group is an allyl group or the like. The ester group is preferably an ester group having an alkyl group as described above.
The OE unit or GO unit has no upper limit as long as it is dissolved in the washing solution as an OE-OP compound, but is from 1 to 50, preferably from 2 to 30.

A specific example will be described below. The numbers in parentheses are
Indicates the number of OE units, GO units or OP units. PO
E (3) / POP (24) block polymer, POE
(4) POP (36) block polymer, POE (1
0) · POP (36) block polymer, POE (5)
・ POP (5) block polymer, POE (9) ・ PO
P (9) block polymer, POE (16) POP
(24) Block polymer, POE (30) POP
(10) Block polymer, POE (1) POP (4)
Cetyl ether, POE (20) / POP (8) cetyl ether, POE (5) nonylphenyl ether, PO
E (15) nonylphenyl ether, POE (12)
POP (6) decyl tetradecyl ether, bis (PO
E (5) • POP (5) mono-2-ethylhexyl ether) methane, POE (10) • POP (10) pentaerythritol ether, POE (9) • POP (9) n
Butyl ether, POE (20) .POP (20) n butyl ether, POE (5) .POP (5) n nonyl ether, POE (12) .POP (12) oleyl ether, PGO (6) lauric ester, PGO (2)
0) Laurate ester, POE monopalmitate (2
0) sorbitan, POE monooleate (20) sorbitan, POE tetraoleate (40) sorbit, P
OE (10) monostearate, POE (8) POP
(8) Distearyl ester, POE (2) POP
(36) POE (2) block polymer, POE (1
0) POP (30) GO (1) block polymer.

In the present invention, the amount of the OE-OP compound added to the developing solution or the washing solution is preferably 0.05 to 50 g / l, more preferably 0.1 to 30 g / l.

The developer used in the present invention includes the above OE
In addition to -OP compounds, developing agents such as polyhydroxybenzenes, 3-pyrazolidinones, alkaline substances such as potassium hydroxide, sodium hydroxide, lithium hydroxide, sodium tertiary phosphate, or amine compounds, preservatives, E.g. sodium sulfite, thickeners such as carboxymethyl cellulose, antifoggants such as potassium bromide, development modifiers such as polyoxyethylene compounds, silver halide solvents such as thiosulfates, thiocyanates,
Additives such as cyclic imides, thiosalicylic acid, mesoionic compounds and the like can be included. The pH of the developer is usually 1
It is 0-14, preferably 12-14. Further, a lipophilic agent for making the silver image lipophilic can be contained. As the lipophilic agent, a compound having a mercapto group or a thione group described below is preferable.

The pH of the washing solution used in the present invention is 4-9.
The pH is preferably about 8 or less, particularly preferably about 7 or less. In the water washing solution, in addition to the OE-OP compound,
Buffers that buffer the pH in the range of 4-8, preferably 5-7, such as phosphate buffers, citrate buffers or mixtures thereof, can be included. Further, a preservative may be contained. Further, it is preferable that the washing solution contains a proteolytic enzyme. In combination with the OE-OP compound, gelatin can be decomposed and removed more effectively, and ink receptivity is further improved.

As the proteolytic enzyme, known vegetable or animal enzymes capable of hydrolyzing proteins such as gelatin can be used. For example, pepsin, rennin, trypsin, chymotrypsin, cathepsin, papain, ficin, thrombin, renin, collagenase, bromelain, bacterial proteinase (for example, bioprase manufactured by Nagase & Co., Ltd.) and the like can be mentioned. Among these, trypsin, papain, ficin, and bacterial proteinase are particularly preferred. The content of the enzyme in the washing solution is
About 0.5 to 50 g / liter is appropriate.

The washing liquid preferably further contains a compound having a mercapto group or a thione group. As the compound having a mercapto group or a thione group, those described in JP-B-48-29723 and JP-A-58-127728 are preferably used. Particularly, a 5- or 6-membered nitrogen-containing heterocyclic compound having a mercapto group or a thione group is preferred.

Specific examples of the 5- or 6-membered nitrogen-containing heterocycle include imidazole, imidazoline, thiazole, thiazoline, oxazole, oxazoline, pyrazoline,
Triazole, thiadiazole, oxadiazole, tetrazole, pyridine, pyrimidine, pyridazine, pyrazine, triazine, etc., and these rings may be two or more condensed rings, which are condensed with a benzene ring or a naphthalene ring. It may be something. Further, it is preferable that the compound does not have a water-soluble group such as a carboxy group and a sulfo group.

Specific examples of such compounds include 2-mercapto-4-phenylimidazole and 2-mercapto-
1-benzylimidazole, 2-mercapto-1-butyl-benzimidazole, 1,3-dibenzyl-imidazolidin-2-thione, 2-mercapto-4-phenylthiazole, 3-butyl-benzothiazoline-2-thione, 3 -Dodecyl-benzothiazoline-2-thione, 2
-Mercapto-4,5-diphenyloxazole, 3-
Pentyl-benzoxazoline-2-thione, 1-phenyl-3-methylpyrazolin-5-thione, 3-mercapto-4-allyl-5-pentadecyl-1,2,4-triazole, 3-mercapto-5-nonyl-1 , 2,4
-Triazole, 3-mercapto-4-acetamide-5
-Heptyl-1,2,4-triazole, 3-mercapto-4-amino-5-heptadecyl-1,2,4-triazole, 2-mercapto-5-phenyl-1,3,4
-Thiadiazole, 2-mercapto-5-n-heptyl-oxathiazole, 2-mercapto-5-nheptyl-oxadiazole, 2-mercapto-5-phenyl-
1,3,4-oxadiazole, 2-heptadecyl-5
-Phenyl-1,3,4-oxadiazole, 5-mercapto-1-phenyl-tetrazole, 3-mercapto-4-methyl-6-phenyl-pyridazine, 2-mercapto-5,6-diphenyl-pyrazine, -Mercapto-4,6-diphenyl-1,3,5-triazine, 2-
Amino-4-mercapto-6-benzyl-1,3,5-
Examples include, but are not limited to, triazines.

The content of the compound having a mercapto group or a thione group in the washing liquid is suitably about 0.01 to 10 g / liter.

In the present invention, the compound having a mercapto group or a thione group is contained in the washing solution, thereby enabling silver ions eluted in the washing solution to be recovered by filtration and preventing the washing solution from being clouded by silver ions. I do. Therefore, by using an OE-OP compound and a compound having a mercapto group or a thione group together, the emulsion layer components such as gelatin and silver ions are efficiently removed from the washing solution, and the clean washing solution without dirt is reused. Enable.

Including a compound having a mercapto group or a thione group in a washing solution is effective in removing gelatin by an OE-OP compound or a protease thereof and a compound having a mercapto group or a thione group. Is promoted to the transferred silver image, and the ink receptivity and printing durability are further improved.

The water washing solution is used for removing a silver halide emulsion layer and the like on an aluminum support.
A method of spraying a washing liquid of 5 to 35 ° C by a jet method,
Alternatively, a method of peeling an emulsion layer with a scrub roller while spraying a washing liquid is known.

The silver image portion and the non-image portion exposed by the water washing process are subjected to a treatment with a finishing solution in order to increase their lipophilicity and hydrophilicity and to protect the plate surface.
In the present invention, in addition to the lipophilic agent in the finishing solution, for protecting the anodized layer of the non-image area and improving the hydrophilicity, arabic gum, dextrin, sodium alginate, propylene glycol ester of alginic acid, hydroxyethyl starch, It is preferable to contain a protective colloid such as carboxymethylcellulose, hydroxyethylcellulose, polyvinylpyrrolidone, polystyrenesulfonic acid, and polyvinyl alcohol.

The lithographic printing plate used in the present invention has at least a physical development nucleus and a silver halide emulsion layer on an aluminum support. The silver halide emulsion is selected from commonly used silver chloride, silver bromide, silver iodide, silver chlorobromide, silver chloroiodobromide, silver iodobromide, etc., but mainly contains silver chloride (50 mol of silver chloride). %). The emulsion type may be either a negative type or a positive type. These silver halide emulsions can be chemically or spectrally sensitized as necessary.

As the gelatin used for the silver halide emulsion layer, various gelatins are used, and alkali-treated gelatin is preferable. Further, hydrophilic polymer compounds such as polyvinylpyrrolidone, various starches, albumin, polyvinyl alcohol, gum arabic, and hydroxyethyl cellulose can be contained. As the hydrophilic colloid to be used, it is desirable to use a hydrophilic colloid layer substantially free of a hardener in order to facilitate the peelability after development. Gelatin content of the silver halide emulsion layer 1 to 5 g / m ^2, preferably from 2 to 4 g / m ² approximately.

The aluminum support used in the present invention is a roughened and anodized aluminum plate, preferably the one described in US Pat. No. 5,427,889.

The physical development nucleus of the physical development nucleus layer used in the present invention may be a physical development nucleus used in a known silver complex salt diffusion transfer method, for example, a colloid such as gold or silver, or a water-soluble salt such as palladium or zinc. Metal sulfide mixed with sulfide can be used. Various hydrophilic colloids can be used as the protective colloid. For details and manufacturing method,
For example, Focal Press, London New York (1972), Andre Lott and Edith
See Weide, "Photographic Silver Halide Diffusion Processes".

In the present invention, a water-swellable intermediate layer described in JP-A-3-116151 may be provided between the physical development nucleus layer and the silver halide emulsion layer.

[0037]

EXAMPLES The present invention will be described below with reference to examples.

Example 1 The electrolytic surface roughening treatment and anodic oxidation of an aluminum support were carried out according to the method described in US Pat. No. 5,427,889 on a plateau having an average diameter of about 5 μm.
0.30 μm pits are about 5,600 per 100 μm ²
And the average diameter of these pits is 0.08 μm
Was obtained as an aluminum plate having a thickness of 0.30 mm. This aluminum plate was anodized after the surface roughening treatment, and had an average roughness (Ra) of 0.5 to 0.6 μm.

A palladium sulfide physical development nucleus solution containing a small amount of a hydrophilic binder was applied to the aluminum support, and then dried. The amount of PdS nuclei contained in the physical development nucleus layer was 3 mg / m ² .

As a silver halide emulsion, alkali-treated gelatin was used, and a control double jet method was used to form a salt of iodobromide doped with potassium hexachloroiridate (IV) having an average particle size of 0.2 μm and having a concentration of 0.006 mmol per mole of silver. A silver emulsion (AgBr 20 mol%, AgI 0.4 mol%) was prepared. Further, this emulsion was subjected to sulfur gold sensitization, and spectral sensitization was performed using 3 mg of a red sensitizing dye per 1 g of silver.

A surfactant was added to the silver halide emulsion thus prepared, and the silver amount was 3 g / m ² and the gelatin amount was 3 g on the aluminum support coated with the physical development nuclei.
/ M ² and dried to obtain a lithographic printing material.

A 633 nm red LD was used for the lithographic printing material.
An image was output by an output device using a laser as a light source, and then processed by a plate-making processor (SLT-85N automatic developing machine manufactured by DuPont) to prepare a lithographic printing plate. The plate-making processor includes a developing step (immersion at 21 ° C. for 15 seconds), a washing step (separating the emulsion layer with a scrub roller while spraying a washing liquid at 33 ° C. for 10 seconds), and a finishing step (21 ° C. 5 seconds shower) and a drying step. The water washing process of the plate making processor is carried out through a tank for storing 30 liters of the washing liquid, a unit for supplying the lithographic printing material from the tank to the lithographic printing material via a pump and peeling and removing the emulsion layer, and a filtration filter arranged outside the system from the tank. It is composed of a unit that circulates washing water.
As the filtration filter, a cylindrical 5 μm filter was used.

A 100 plate plate making process was carried out using the following developing solution, washing solution and finishing solution. <Developer A> Sodium hydroxide 20 g Hydroquinone 20 g 1-Phenyl-3-pyrazolidinone 2 g Anhydrous sodium sulfite 80 g Monomethylethanolamine 6 g Anhydrous sodium thiosulfate 6 g Ethylene diamine tetraacetate sodium salt 5 g Polyethylene glycol (average molecular weight 400) 10 g To 1000 ml. pH is 1
It was adjusted to 3.0.

<Washing solution A> 40 g of first potassium phosphate water is added to adjust the total amount to 1000 ml. pH is 6.
Adjusted to zero.

<Washing solution B> The washing solution A had an average molecular weight of 4
1.5 g of polyethylene glycol of 00 were added.

<Washing solution C> 1.5 g of dimethyl laurylamine oxide was added to the above washing solution A.

<Washing solution D> POE (5) was added to the washing solution A.
-1.5 g of POP (5) block polymer was added.

<Rinse solution E> POE (1
5) 1.5 g of nonylphenyl ether was added.

<Washing Fluid F>
(5) .POP (5) mono-2-ethylhexyl ether) methane was added in an amount of 1.5 g.

<Washing solution G> PGO (6) was added to the washing solution A.
1.5 g of lauric ester were added.

<Finishing Solution> Gum arabic 10 g Protease 2 g 2-mercapto-5-n-heptyl-oxadiazole 1 g Triethanolamine 26 g Sodium monophosphate 10 g Water is added to adjust the total amount to 1000 cc. pH 6.0
Was adjusted. Proteolytic enzyme is Bioprase AL
−15.

For the first and 100th lithographic printing plates prepared by the method described above, the printing press Heidelberg T
OK (Trademark of offset printing machine manufactured by Heidelberg), Ink (New Champion Ink H manufactured by Dainippon Ink Co., Ltd.)
Printing was performed using a commercially available humidifying solution for PS plates, and the ink receptivity (inking) was evaluated based on the number of sheets until the image density did not change. The water retention was evaluated by observing the stain on the non-image area when 100,000 sheets were printed, and evaluated according to the following four criteria. Reference numeral 4 indicates no stain, and reference numeral 3 indicates a slight stain. 2 is partially stained. 1 is stained on the entire surface.

[0053]

[Table 1]

As is clear from the above results, OE-OP
It can be seen that the washing solution of the present invention containing a compound is superior in ink acceptability and water retention as compared with the comparative washing solution. In the water washing solution of the present invention, the eluted gelatin was agglomerated and precipitated during the treatment, so that it could be easily removed from the system. Further, the washing liquid of the present invention can maintain high printing performance without lowering of printing performance due to running processing.

Example 2 Using the developing solution A of Example 1, the rinsing solution A of Example 1, and the rinsing solution H described below, the condition of the stain of the rinsing solution when the 100-plate processing was performed in the same manner as in Example 1 was examined. Observed.

<Washing Solution H> 2-mercapto-5-nheptyl-oxadiazole 0.5 g triethanolamine 13 g polystyrenesulfonic acid (average molecular weight 500,000) 10 g POE (10) / POP (36) block polymer 5 g 1 Potassium phosphate 40 g Water is added to adjust the total amount to 1000 cc. pH is 6.
Adjusted to zero.

As a result, the comparative washing solution A had considerable stains and cloudiness, and had a putrefactive smell of gelatin. However, the washing solution H of the present invention had no stain, cloudiness, and putrefaction smell, and did not accept ink. The properties have also been significantly improved.

Example 3 The OE-OP compound of the present invention and the comparative compound used in the washing solutions B to G of Example 1 were added to the developer A of Example 1 in an amount of 3 g each, and tested. A lithographic printing plate made with a developer to which the OE-OP compound of the present invention has been added is superior in both ink receptivity and water retention to a lithographic printing plate made with a developer having a comparative compound added thereto. there were.

[0059]

In the plate making process of an aluminum lithographic printing plate utilizing a silver complex salt diffusion transfer method, an OE-OP
The presence of the compound improves ink receptivity and water retention at the start of printing, further increases the efficiency of gelatin recovery by filtration of the washing solution, prevents decay of the washing solution during the running process, It is possible to prevent a decrease in ink acceptability and water retention.

Further, by containing a compound having a mercapto group or a thione group in the washing solution, silver ions eluted in the washing solution can be easily collected by filtration, and OE-OP
The combination with the compound makes it possible to reuse a washing liquid free of stains and white turbidity, and further improves ink acceptability.

Claims (1)

[Claims] A lithographic printing material having physical development nuclei between an aluminum support and a silver halide emulsion layer, after exposure,
In a method of making a lithographic printing plate wherein at least a developer and a washing solution are processed in this order, the developing solution and / or the washing solution has at least one of an oxyethylene unit and a glycerol unit, and is more than those units. A method for making a lithographic printing plate, comprising a nonionic compound having a hydrophobic structural part.