JPH1144958A - Developing method of lithographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To faithfully reproduce a silver image on the printing face of a lithographic printing plate to a printed material by incorporating 1-phenyl-3- pyrazolidinone or its deriv. into the structural layers of the lithographic printing plate and developing in the presence of an azole compd. having no mercapto group. SOLUTION: This lithographic printing plate has a physical developing nuclear layer between an aluminum supporting body and a silver halide emulsion layer. The structural layers of the lithographic printing plate contain a 1- phenyl-3-pyrazolidinone or its deriv. and the printing plate is developed in the presence of an azole ring compd. having no mercapto group. The 1-phenyl-3 pyrazolidinone or its deriv. is expressed by the formula. In the formula, R<1> is a substd. or unsubstd. phenyl group, R<2> to R<4> are independently hydrogen atom, a substd. or unsubstd. alkyl group, etc. Thereby, difference between the image on the printing face of the lithographic printing plate and the image on a printed material can be substantially eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for developing 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.

As described therein, a lithographic printing plate using the DTR method includes a two-sheet type in which a transfer material and an image receiving material are separated, or a monolithic plate in which they are provided on a single support. Two types of sheet type are known.
A two-sheet type lithographic printing plate is disclosed in
This is described in detail in JP-A-158844. For the mono-sheet type, see JP-B-48-30562.
No. 51-15765, JP-A-51-111103
And JP-A Nos. 52-150105.

A lithographic printing plate of a monosheet type utilizing a silver complex salt diffusion transfer method using an aluminum plate as a support (hereinafter referred to as an aluminum lithographic printing plate), which is an object of the present invention, is disclosed in JP-A-57-118244. No. 57-158
Nos. 844 and 63-260491, JP-A-3-116
No. 151, 4-282295, U.S. Pat.
Nos. 7,131, 5,427,889 and the like.

[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.

In a lithographic printing plate using the DTR method, silver halide crystals that have produced photosensitive nuclei by exposure become blackened silver by chemical development, while unexposed silver halide crystals are converted to silver salt complex in a developing solution. The agent forms a silver salt complex and diffuses to the physical development nucleus, causing physical development in the presence of the nucleus to form a silver image area.

The aluminum lithographic printing plate to which the present invention is applied has a different structure from a conventionally used lithographic printing plate having a physical development nucleus on a silver halide emulsion layer. The structure has a physical development nucleus under the emulsion layer. It has been found that the difference between the two configurations affects the properties of the silver image formed by the plate making process.

That is, depending on whether the silver salt complex in the emulsion layer diffuses upward (toward the developer) or downward (toward the support), the transfer efficiency and the like differ, which affects the transfer silver formation. Can be considered. That is, the aluminum lithographic printing plate targeted by the present invention is inferior in transfer efficiency, and it is easy to form a silver image with a small amount of transferred silver. It had a bad problem, which is unique to aluminum lithographic printing plates. This problem has caused a reduction in print reproducibility in which a silver image of a lithographic printing plate cannot be faithfully reproduced on a printed material.

[0010] The printing reproducibility means that the ink is reliably applied to the silver image of the lithographic printing plate during printing, and the same image as the silver image can be reproduced on a printed material. If the print reproducibility is good, there is an advantage that the image quality of the printed matter can be understood by looking at the silver image of the lithographic printing plate before printing, which is important when making a lithographic printing plate. When print reproducibility is poor, there is a problem that it is impossible to know whether or not a desired printed matter is obtained unless printing is performed, and the work efficiency of plate making and printing is reduced.

[0011] Usually, the ink riding property of a silver image is determined by a compound (lipophilic agent) which makes the silver image lipophilic, for example,
By reacting a compound having a mercapto group or a thione group described in JP-A-29723 and JP-A-58-127928, a silver image is sensitized to develop ink-inking properties. Similarly, with regard to the aluminum lithographic printing plate to which the present invention is applied, the silver image portion is made sensitized to improve the ink riding property. However, the silver image formed with the low transfer efficiency as described above is hardly sensitized, and has caused the problem of print reproducibility as described above.

Japanese Patent Application Laid-Open No. 7-72630 discloses a 1-phenyl-5-mercapto-substituted compound having a substituent such as a carboxy group in order to obtain a high contrast and good ink receptivity in a printing area. Although development in the presence of tetrazole and processing in the presence of a benzotriazole compound are disclosed in JP-A-7-319165, the desired performance has not been achieved.

On the other hand, a lithographic printing plate utilizing the DTR method is exposed to a plate making camera for several seconds to several tens of seconds by a plate making camera to make a plate, and a laser beam (a helium / neon laser, an argon laser, a semiconductor laser, A lithographic printing plate for scanning exposure that directly makes a plate using a diode or the like is known. Scanning exposure has the advantage that it has better sharpness and resolution than camera exposure.

However, even if a lithographic printing plate having a high resolution is obtained by the scanning exposure, as described above, the ink running property of the silver image is poor and the fine lines and halftone dots on the plate surface cannot be faithfully reproduced on the printed matter. However, there is a serious problem that the advantage of the lithographic printing plate for scanning exposure cannot be utilized.

[0015]

SUMMARY OF THE INVENTION An object of the present invention is to provide a lithographic printing plate development method capable of solving the above-mentioned problems and reproducing a silver image on a lithographic printing plate surface faithfully in a printed matter. That is. In particular, it is an object of the present invention to provide a method of developing a lithographic printing plate suitable for utilizing the high resolution of the lithographic printing plate for scanning exposure.

[0016]

An object of the present invention is to provide a method for developing a lithographic printing plate having a physical development nucleus layer between an aluminum support and a silver halide emulsion layer, the lithographic printing plate comprising This can be achieved by carrying out development in the presence of an azole ring compound containing 1-phenyl-3-pyrazolidinone or a derivative thereof in the layer and having no mercapto group.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. 1-phenyl- contained in the constituent layers of the lithographic printing plate of the present invention
3-Pyrazolidinone or a derivative thereof is represented by the following general formula.

[0018]

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In the formula, R ¹ is a substituted (halogen atom, nitro group, carboxyl group, alkoxy group, alkyl group having 1 to 5 carbon atoms, etc.) or unsubstituted phenyl group, R ² , R ³ , R
^{And 4} is a hydrogen atom, a substituted or unsubstituted alkyl group (for example, an alkyl group having 1 to 5 carbon atoms or a substituent such as a halogen atom, a carboxyl group, or a hydroxyl group at an appropriate position of the alkyl group. Or an alkoxy group (for example, an alkoxy group having 1 to 5 carbon atoms), or a substituted (for example, a phenyl group, a halogen atom, a nitro group, a carboxyl group, an alkyl group having 1 to 5 carbon atoms) or an unsubstituted aryl group ( For example, a phenyl group).

The above-mentioned 1-phenyl-3-pyrazolidinone or a derivative thereof also includes a precursor represented by the general formula (2) or (3).

[0021]

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In the formula, R ⁵ has the same meaning as R ¹ in Chemical formula ^1, and R ⁶ and R ⁷ have the same meaning as R ² and R ^{3 in} Chemical formula 1. R ⁸ represents a hydrogen atom, a substituted or unsubstituted alkyl group (for example, an alkyl group having 1 to 5 carbon atoms or a substituent such as a halogen atom, a carboxyl group, or a hydroxyl group at an appropriate position of the alkyl group; An alkoxy group (for example, an alkoxy group having 1 to 5 carbon atoms), a substituted (for example, a phenyl group, a halogen atom, a nitro group, a carboxyl group, an alkyl group having 1 to 5 carbon atoms) or an unsubstituted aryl group (for example, Phenyl group), a substituted or unsubstituted alkenyl group (for example,
Represents an alkenyl group having 1 to 5 carbon atoms, a carboxyalkenyl group having 1 to 5 carbon atoms or the like, or an aryloxy group (for example, a phenoxy group or carboxyphenoxy group having 1 to 5 carbon atoms).

[0023]

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In the formula, R ⁹ has the same meaning as R ^{1 in} Chemical Formula ^1, and R ¹⁰ and R ¹¹
Has the same meaning as R ² and R ^{3 in} Chemical Formula 1. R ¹² has the same meaning as R ⁸ in Chemical Formula 2.

Specific examples of 1-phenyl-3-pyrazolidinone or a derivative thereof used in the present invention are shown below.

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Among the above 1-phenyl-3-pyrazolidinones or derivatives thereof, at least one substituted or unsubstituted alkyl group (for example, methyl,
An unsubstituted alkyl group such as an ethyl or propyl group, or a substituted alkyl group having a halogen atom, a hydroxyl group, a carboxyl group, or the like, or an alkoxy group (for example, having 1 to 5 carbon atoms)
Is particularly preferable.

The above 1-phenyl-3-pyrazolidinone or a derivative thereof is dissolved in an appropriate solvent (eg, water, methanol, ethanol, dimethylformamide, etc.),
When used in a coating solution but cannot be dissolved or when an organic solvent is not used, it can be added as a solid-dispersed liquid.

The constituent layer containing 1-phenyl-3-pyrazolidinone or a derivative thereof may be, for example, a silver halide emulsion layer, a physical development nucleus layer having physical development nuclei, a halogenated layer for the purpose of safety light resistance, scratch resistance and the like. A timing layer provided above or below the silver emulsion layer, an antistatic layer provided for the purpose of preventing static electricity, and the like. Preferably, it is contained in a silver halide emulsion layer.

The content of 1-phenyl-3-pyrazolidinone or a derivative thereof is determined by using silver halide (in terms of silver nitrate).
30 to 500 mg / g is appropriate, preferably 60 mg / g.
It is about 200 mg. Further, the compound represented by the general formula (1), (2) or (3) may be contained in two or more constituent layers. Further, 1-phenyl-3-pyrazolidinone or a derivative thereof is preferably contained in a developer. The amount added to the developer is about 0.1 to 10 g / l, preferably 1 to 5 g / l. The effect is more remarkably exhibited by including the lithographic printing plate and the developer in the lithographic printing plate.

The azole compound having no mercapto group used in the present invention is represented by the following general formula.

[0056]

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In the formula, R ₁ is a hydrogen atom, a halogen atom, or an alkyl group (eg, methyl, ethyl, propyl,
Isopropyl, butyl group, etc.), amino group, alkenyl group (eg, allyl group, etc.), aralkyl group (eg, benzyl, phenethyl group, etc.), aryl group (eg, phenyl,
o-tolyl, m-tolyl, p-tolyl, m-chlorophenyl, p-nitrophenyl group, etc.), alkoxy group, hydroxy group, carboxy group, sulfo group, alkoxycarbonyl group, acylamide group, sulfonamide group, acyl group, Represents an alkylsulfonyl group or the like. n represents an integer of 0 to 4, and when n is 2 or more, they may be the same or different. Z represents an atomic group necessary to form an azole ring, and examples of the azole ring include pyrrole, imidazole, pyrazole, triazole, tetrazole, oxazole, oxadiazole, thiazole, thiadiazole and the like. These rings may be condensed with a benzene ring or a naphthalene ring. Preferred specific examples of Chemical formula 29 used in the present invention are shown below.

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Among the above compounds, imidazole,
Triazole or a substituted derivative thereof is preferred,
Particularly, imidazole having a phenyl group as a substituent and triazole having an amino group are preferable. By containing imidazole or a substituted derivative thereof in a developing solution, more effects can be obtained.

The compounds used in the present invention are contained in a lithographic printing plate and / or a developer. When it is contained in a lithographic printing plate, it can be contained in any of the constituent layers, but is preferably contained in a silver halide emulsion layer. When added to lithographic printing plates, the amount added is 0.1
５００500 mg / m ² , preferably about 0.1-100 mg / m ² . When it is contained in a developer, the content is preferably about 0.1 to 10 g / liter. Two or more azole compounds may be used in combination.

In the present invention, the lithographic printing plate contains 1-phenyl-3-pyrazolidinone or a derivative thereof,
It is considered that the development processing in the presence of an azole ring compound having no mercapto group optimizes the balance between physical development and chemical development in DTR development.

The lithographic printing plate to which the present invention is directed has 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 type of emulsion may be either a negative type or a positive type. These silver halide emulsions can be chemically or spectrally sensitized as necessary.

In the present invention, sensitizing dyes suitably used for the lithographic printing plate for scanning exposure are those compatible with an argon laser, as disclosed in Japanese Patent Application Nos. 7-283280 and 8-2772.
JP-A-2-251853 and JP-A-3-27455 for the sensitizing dyes described in No. 3 and for red and infrared lasers.
And sensitizing dyes described in JP-A-4-9853 and JP-A-8-45874.

Gelatin is preferably used as the hydrophilic colloid in the silver halide emulsion layer when preparing silver halide grains. Various gelatins such as acid-treated gelatin and alkali-treated gelatin can be used as the gelatin.
Further, those modified gelatins (for example, phthalated gelatin, amidated gelatin, etc.) can also be used. Further, a hydrophilic polymer compound such as polyvinylpyrrolidone, various starches, albumin, polyvinyl alcohol, gum arabic, and hydroxyethyl cellulose can be contained. As the hydrophilic colloid used,
It is desirable that a hardener is not substantially contained in order to facilitate peelability after development. The amount of gelatin in the silver halide emulsion layer is about 1 to 10 g / m ² , preferably ^{2 to 5} g / m ^2.
It is.

The roughened and anodized aluminum plate used in the present invention is described in, for example, US Pat. No. 5,427,
No. 889, for example.

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.

The developing solution used in the present invention includes developing agents such as polyhydroxybenzenes, 3-pyrazolidinones, and alkaline substances such as potassium hydroxide, sodium hydroxide, lithium hydroxide, and tertiary sodium phosphate.
Alternatively, amine compounds, preservatives such as sodium sulfite, thickeners such as carboxymethylcellulose, antifoggants such as potassium bromide, development modifiers such as polyoxyalkylene compounds, silver halide solvents such as thiosulfate and thiocyanate Additives such as acid salts, cyclic imides, and thiosalicylic acid can be included.

The pH of the developer is usually about 10 to 14, preferably about 12 to 14. The pretreatment (for example, anodic oxidation) of the aluminum support of the lithographic printing plate to be used,
It depends on the photographic element, the desired image, the type and amount of various compounds in the developer, the development conditions, and the like.

[0099]

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

Example 1 An average diameter of about 5 μm was obtained by electrolytic surface roughening treatment and anodic oxidation.
A 0.30 mm thick aluminum plate having about 5,600 pits having a diameter of 0.03 to 0.30 μm per 100 μm ² on the plateau and having an average diameter of these pits of 0.08 μm was obtained. . This aluminum plate is anodized after the surface roughening treatment, and has an average roughness (Ra) of 0.5 to
It was 0.6 μm.

As physical development nuclei, JP-A-63-2088
After preparation according to the method for preparing a nuclear liquid (A) described in JP-A-43-43, the pH was adjusted to 6.8. This physical development nucleus solution was applied onto the aluminum support.

A silver halide emulsion was prepared as follows. A silver chloride emulsion was prepared by simultaneously adding an aqueous solution of silver nitrate and an aqueous solution of sodium chloride at an addition rate of 4 ml / min while maintaining the aqueous solution of inert gelatin at 60 ° C. and stirring vigorously. These emulsion grains have an average size of 0.3
μ, the crystal habit was cubic, and 90% by weight or more of all particles were contained within ± 30% of the average particle size. The emulsion thus obtained was subjected to precipitation and washing with a conventional method, and then redissolved. Further, sodium thiosulfate and chloroauric acid were added thereto, and the mixture was chemically sensitized and further ortho-sensitized.

A surfactant was added to the prepared silver halide emulsion to prepare a coating solution (pH: 4.0). To this coating solution were added a 1-phenyl-3-hydroxyperidinone derivative in an amount of 100 mg / g of silver halide (in terms of silver nitrate), and an azole compound and the following comparative compound in an amount of 10 mg / m ² . Details are shown in Table 1. This silver halide emulsion was coated on an aluminum support coated with physical development nuclei so that the silver amount was 2 g / m ² (the gelatin amount was 3 g / m ² ).

[0104]

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The lithographic printing plate thus obtained was exposed to a camera using a resolution chart so that a fine line of 50 μm was obtained, and then processed by a plate-making processor (DLT Pont's SLT-8N automatic developing machine). To make a lithographic printing plate. The plate-making processor has a development process (22 ° C,
Immersion for 15 seconds), water washing process (wash water at 33 ° C for 10 seconds)
The emulsion layer is peeled off with a scrub roller while showering for 2 seconds), finishing process (21 ° C., 5 seconds shower)
And a drying step. The developing solution, washing solution and finishing solution are shown below.

<Developer> Hydroquinone 20 g 1-phenyl-4-human peroxymethyl-4-methyl-3-hydroxyperidinone 2 g Sodium sulfite 80 g EDTA 4 g Sodium hydroxide 22 g N-methylethanolamine 10 g 2-mercapto-5-nheptyl- Oxadiazole 0.5 g Polyethylene glycol (average molecular weight 400) 10 g Add water to make the total amount 1000 cc. The pH is adjusted to 12.8.

<Washing solution> Proteolytic enzyme 2 g 2-mercapto-5-n-heptyl-oxadiazole 0.5 g Triethanolamine 13 g Potassium monophosphate 40 g Water is added to adjust the total amount to 1000 cc. The pH was adjusted to 6.0. The proteolytic enzyme is bioprase AL-15 (bacterial proteinase, manufactured by Nagase & Co., Ltd.).

<Finishing solution> Gum arabic 10 g 2-mercapto-5-n-heptyl-oxadiazole 0.5 g Triethanolamine 26 g Sodium monophosphate 10 g Water is added to adjust the total amount to 1000 cc. The pH was adjusted to 6.0. The proteolytic enzyme is bioprase AL-15.

The obtained printing plate was transferred to a printing machine Heidelberg M
O (Heidelberg Offset printing machine trademark) for printing. For the 100th printed matter after starting printing,
The reproducibility of the fine line was measured with a microdensitometer.
Table 1 shows the line width of a 50 μm thin line on the printing plate reproduced on the printed matter. The closer the numerical value of the printed thin line is to 50 μm, the better.

[0112]

[Table 1]

Table 1 shows that when the present invention was used, the difference between the fine lines of the printing plate and the printed matter was reduced, and the reproduction was almost faithful.

Example 2 Instead of adding the azole compound of the present invention and the comparative compound added to the silver halide emulsion layer of Example 1 to the silver halide emulsion layer, processing was performed by adding 2 g / liter to each of the developing solutions. did. The obtained printing plate was tested in the same manner as in Example 1. As a result, the same result as in Example 1 was obtained.

Example 3 An alkali-treated gelatin was used as a protective colloid, and an average particle size of 0.25 μm was obtained by a control double jet method.
A silver chloroiodobromide emulsion (AgBr 20 mol%, AgI 0.4 mol%) was prepared by doping potassium hexachloroiridate (IV) with 0.006 mmol per mol of silver. Further, this emulsion was subjected to sulfur gold sensitization, and spectral sensitization was performed using 3 mg of a sensitizing dye represented by Chemical Formula 68 per 1 g of silver.

[0116]

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A surfactant was added to the silver halide emulsion thus prepared to prepare a coating solution. To this coating solution,
100 mg per 1 g of silver halide (in terms of silver nitrate) was added to the 1-phenyl-3-perazoperidinone derivative, and 10 mg / m ² of an azole compound and the following comparative compound were added. Details are shown in Table 2. This silver halide emulsion layer was coated on the aluminum support coated with the physical development nuclei of Example 1 so that the silver amount was ² g / m ² (gelatin amount was 3 g / m ² ), dried and scanned. A lithographic printing material for exposure was obtained.

The lithographic printing material was output by an output device using a 63 nm red LD laser as a light source so that a 10% halftone dot image was obtained on the plate surface, and processed in the same manner as in Example 1 to obtain a printing plate. Was. The obtained printing plate was printed in the same manner as in Example 1,
The halftone dot area of the printed matter after printing 100 sheets was measured.
Table 2 shows the results. The closer the halftone dot area of the printed matter is to 10%, the more faithfully the plate image is reproduced on the image of the printed matter.

[0119]

[Table 2]

A lithographic printing plate for scanning exposure capable of coping with a laser light source can obtain a high resolution, but a comparative printing plate has low image reproducibility with respect to printed matter. On the other hand, the printing plate of the present invention reproduces halftone dots on the plate surface almost exactly.

[0121]

According to the present invention, in printing using an aluminum lithographic printing plate utilizing a silver complex salt diffusion transfer method,
The difference between the image on the plate of the lithographic printing plate and the image of the printed matter can be substantially eliminated. In particular, in the case of a lithographic printing plate for scanning exposure which can provide a high resolution, the advantage of the lithographic printing plate for scanning exposure can be exploited for the first time by faithfully reproducing a silver image on the plate surface in a printed matter.

Claims (3)

[Claims] 1. A method for developing a lithographic printing plate having a physical development nucleus layer between an aluminum support and a silver halide emulsion layer, wherein the lithographic printing plate contains 1-phenyl-3-pyrazolidinone or Containing its derivatives,
A method for developing a lithographic printing plate, comprising developing in the presence of an azole compound having no mercapto group. 2. The method according to claim 1, wherein the lithographic printing plate is a lithographic printing plate for scanning exposure. 3. The method for developing a lithographic printing plate according to claim 1, wherein the development is performed with a developer having 1-phenyl-3-pyrazolidinone or a derivative thereof.