JP3113448B2 - Lithographic printing plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithographic printing plate to which a silver complex salt diffusion transfer method is applied, which has improved printing durability and storage stability over time.

[0002]

2. Description of the Related Art A lithographic printing plate comprises an oleophilic image portion that receives oily ink and an oil-repellent non-image portion that does not receive ink. Generally, the non-image portion is a hydrophilic portion that receives water. It is composed of sex parts. In normal lithographic printing, both water and ink are supplied to the plate surface, the image portion selectively receives color ink, and the non-image portion selectively receives water, and the ink on the image line is, for example, paper or the like. Printing is performed by transferring to a printing medium.

[0003] Therefore, in order to obtain good printed matter, the difference between the lipophilicity and the hydrophilicity between the image area and the non-image area is sufficiently large, and when the water and the ink are supplied to the printing plate, the image area is not sufficient. It is necessary to accept the amount of ink and not to accept the ink at all in the non-image area.

A lithographic printing plate using a silver complex salt diffusion transfer method (DTR method), particularly a lithographic printing plate having a physical development nucleus layer on a silver halide emulsion layer, is disclosed, for example, in US Pat.
No. 8,114, No. 4,134,769, No. 4-1
No. 60,670, No. 4,336,321, No. 4,
Nos. 501,811, 4,510,228, and 4,621,041, and the like. The exposed silver halide crystal undergoes chemical development by DTR development to produce a black color. It becomes silver and forms a hydrophilic non-image area.On the other hand, unexposed silver halide crystals are converted into a silver salt complex by a silver salt complexing agent in a developing solution and diffused to the physical development nucleus layer on the surface to form nuclei. Causes physical development to form an image portion mainly composed of physically developed silver having ink receptivity.

[0005] As described above, the lithographic printing plate requires gelatin-
Since the silver image deposited on the physical development nucleus layer on the silver halide emulsion layer is used as an ink-accepting image area, the image area is higher than that of a general lithographic printing plate (for example, PS plate). The lithographic printing plate, which has insufficient resistance to mechanical abrasion in the part, especially the lithographic printing plate for the purpose of improving the stain resistance, has a smooth surface, so that the image part is missing or the ink receptivity of the image part Has a disadvantage that it is easily lost gradually and printing durability is low.
Further, by storing the lithographic printing plate for a long period from the time it is manufactured until the time it is made, the printing durability of the lithographic printing plate is significantly reduced, and improvement is desired.

In order to overcome this drawback, it has been known that the printing durability is improved by suppressing the fogging by chemical development to maintain the amount of physically developed silver particularly required for printing. 1984-102815. In addition, if the hardness of gelatin is increased or the amount of physical development nuclei is increased, background staining occurs and the printing durability of the lithographic printing plate is significantly reduced. Normally, the mechanical strength of the image portion and the background stain become mutually prominent, and the printing durability of the lithographic printing plate has a limit,
In particular, the printing durability of a sample stored for a long period of time is remarkably reduced, and development of a new technology exceeding this limit has been awaited.

The effect of surface irregularities of a lithographic printing plate on printability is known in the field of PS plates, but is also an important factor in a lithographic printing plate using the silver complex salt diffusion transfer method of the present invention. It was revealed. In particular, in a lithographic printing plate using a silver complex salt diffusion transfer method, the non-image area is mainly made of a gelatin film, and although it is originally high in hydrophilicity, it is matted to improve the printing durability of the image area. In general, the matting property of the surface is designed to be large (the surface irregularities are large) by the agent. Japanese Patent Application Nos. 3-259655, 3-268765, 3-268765, 3-2
68767, same Hei 3-268766, same Hei 3-2856
No. 23 discloses that there is a correlation between the matte property of the surface and the print stain, and that the smoothing of the surface can significantly reduce the print stain in the non-image area.

A lithographic printing plate using a silver complex salt diffusion transfer method with improved stain resistance is designed to reduce the surface mattability and prevent the accumulation of ink in the concave portions on the surface of the non-image area. This is a condition that is inconsistent with the conventional design for improving the printing durability. Therefore, a lithographic printing plate having satisfactory press life even under such a design has been desired.
Further, since the lithographic printing plate is stored for a long period from the time of manufacture to the time of plate making, the disadvantage that image quality is deteriorated due to softening of photographic characteristics and the resulting deterioration in printing durability is particularly remarkable. Had been requested. That is, a lithographic printing plate using the silver complex salt diffusion transfer method is processed by a camera processor or an automatic developing machine. Storage at elevated locations significantly affects the photographic properties of the printing plate, leading to poor printing performance. As described above, since the storage condition is particularly affected, the printing performance tends to be fluctuated. Thus, a planographic printing plate having improved storage stability over time has been desired.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a lithographic printing plate using a silver complex salt diffusion transfer method, which has excellent stain resistance, printing durability and storage stability over time.

[0010]

An object of the present invention is to provide a silver salt diffusion transfer method comprising sequentially coating a support with at least one undercoat layer, a silver halide emulsion layer and a physical development nucleus layer. In the applied lithographic printing plate,
This was achieved by incorporating a compound represented by the general formula represented by the formula (2) in the silver halide emulsion layer.

In Chemical Formula 1, R1 and R2 each represent a hydrogen atom, an alkyl group, an aryl group, an aralkyl group, an alkenyl group, an amino group, an acylamide group, or a sulfonamide group.

In Chemical Formula 2, M ⁺ represents a hydrogen ion, an alkali metal ion or an ammonium ion. R3, R4, R
5 and R6 are each a hydrogen atom, an alkyl group, an alkenyl group, an aralkyl group, an aryl group, a halogen atom, an alkoxy group, a hydroxy group, an amino group, a carboxy group, a sulfone group, an alkoxycarbonyl group, an acylamide group,
Shows a sulfonamide group. And R3, R4, R5 and R
6 may be connected to form a ring.

Specific examples of the compound of the general formula represented by Chemical formula 1 used in the present invention include Chemical formulas 3 to 16, but the present invention is of course not limited to these compounds.

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[0027]

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The compound of the formula (I) used in the present invention can be added to any layer such as a silver halide emulsion layer and an undercoat layer, but is preferably added to the undercoat layer. Added. Although the amount of addition depends on the compound and the layer structure, it is 1 × 10 ⁻⁴ mmol / m ^{2 to} 1.6 mmol / m ^2.
And preferably from 1.0 × 10 ⁻³ mmol / m ² to
It is in the range of 0.2 mmol / m ² .

Specific examples of the compound of the general formula represented by Chemical formula 2 used in the present invention include Chemical formulas 17 to 30, but the present invention is of course not limited thereto.

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[0043]

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The amount of the compound represented by the general formula (II) used in the present invention depends on the compound and the layer constitution, but is 1 × 10 ^-2 mmol / mole per mol of silver halide.
^{2 to} 1.0 mmol / m ² , preferably 0.1
The range is from 10 mmol / m ² to 10 mmol / m ² .

A lithographic printing plate for the purpose of improving stain resistance has a smooth surface to prevent the accumulation of ink on the surface of the non-image area, and to improve the water-ink responsiveness of the plate surface during printing. The liquid absorption of the printing plate has been reduced. Although the reduction in the liquid absorption of the lithographic printing plate promotes DTR development, the amount of silver deposited tends to increase, but the printing durability significantly decreases with the decrease in the adhesive strength of physically developed silver. In particular, under high temperature conditions such as 40 ° C. processing during development, DTR development is promoted, and the printing durability is significantly reduced. Further, such a smooth surface of the lithographic printing plate causes a large damage to image silver at the time of printing due to low matting property, and further, the adhesive strength of physically developed silver is reduced. As described above, there is a problem that the reduction of the liquid absorption of the lithographic printing plate and the reduction of the printing durability due to the smooth surface of the lithographic printing plate are not sufficient only by suppressing the fog level. The compound of the general formula represented by the chemical formula 1 and the compound of the general formula represented by the chemical formula 2 of the present invention act on the chemical development and especially on the DTR development, to optimize the development balance and the photographic properties during long-term storage. Of the physical developed silver can be maintained under the optimum conditions, and the printing durability can be ensured at a wide range of processing temperatures, long-term storage, or storage under high humidity conditions. It has been found.

The lithographic printing plate which is the object of the present invention contains gelatin, and the layer containing the gelatin is an undercoat layer, an emulsion layer, and may be a physical development nucleus layer. These gelatin-containing layers can be hardened with a gelatin hardener.
Gelatin hardeners include, for example, inorganic compounds such as chrome alum, aldehydes such as formalin, glyoxal, malealdehyde and glutaraldehyde, N-methylol compounds such as urea and ethylene urea, mucochloric acid, 2,3 Aldehydes such as dihydroxy-1,4-dioxane, 2,4-dichloro-6-hydroxy-
Compounds having an active halogen such as S-triazine salt, 2,4-dihydroxy-6-chloro-S-triazine salt, divinyl sulfone, divinyl ketone, N, N, N
-Tricloyl hexahydrotriazine, compounds having two or more ethyleneimino groups or epoxy groups as active three-membered rings in a molecule, one of various compounds such as dialdehyde starch as a polymer hardener or Two or more can be used.

The hardener can be added to all layers or to some or only one layer.
Of course, in the case of two-layer simultaneous application, the diffusible hardener can be added to only one of the layers. The addition method can be added at the time of emulsion production or in-line at the time of coating.

A part of the gelatin in the gelatin-containing layer of the present invention is water-soluble gelatin, starch, dextrin, albumin, sodium alginate, hydroxyethylcellulose, acacia, polyvinyl alcohol, polyvinylpyrrolidone, carboxymethylcellulose, polyacrylamide, styrene. It can be substituted with one or more hydrophilic polymers such as maleic anhydride copolymer and polyvinyl methyl ether-maleic anhydride copolymer. Further, an aqueous vinyl polymer dispersion (latex) can be added to the gelatin layer.

The polymer binder of the undercoat layer is generally 0.5
More preferably to 10 g / m ² is 1 to 6 g / m ^2. The undercoat layer may contain pigments such as carbon black, dyes and the like for the purpose of preventing halation. Further, a photographic additive such as a developing agent can be included. The undercoat layer is disclosed in
8-5503, 48-100203, and 49-1
6507.

The matting agent used in the present invention has an average particle size of 1 to 1.
10 micron solid powder, for example, silica particles,
Etc. In the present invention, silica particles having an average particle diameter of 1 to 5 microns are preferred. In particular, silica particles surface-treated with hydrogen fluoride are preferable because of their excellent dispersion stability.
Specific examples of the silica particles include Siloid manufactured by Fuji Divison Chemical Co., Ltd. In the present invention, the matting agent may be contained in any coating layer on the side including the silver halide emulsion layer, but preferably, a subbing layer between the support and the silver halide emulsion layer, And / or a silver halide emulsion layer. The amount of the matting agent varies depending on various conditions, but is 0.1 g / m ^2.
Ｇ3.0 g.

The silver halide emulsion layer includes, for example, silver chloride,
It consists of silver bromide, silver chlorobromide, and those containing silver iodide. The silver halide crystals may contain a heavy metal salt such as a rhodium salt, an iridium salt, a palladium salt, a ruthenium salt, a nickel salt, a platinum salt, and the like, and the addition amount is 10 ^-8 to 10 ^-3 per mol of silver halide. Is a mole. The crystal form of the silver halide is not particularly limited, and may be cubic to tetradecahedral grains, or core-shell or tabular grains. The silver halide crystal may be a monodisperse or polydisperse crystal,
Its average particle size is in the range of 0.2-0.8 μm. One preferred example is a monodispersed or polydispersed crystal containing 80 mol% or more of silver chloride, which contains a rhodium salt or an iridium salt.

The silver halide emulsion can be sensitized in various ways as it is manufactured or coated. It is preferred to chemically sensitize by methods well known in the art such as, for example, with sodium thiosulfate, alkyl thioureas, or with gold compounds such as rhodium gold, gold chloride, or a combination of both. Silver halide emulsions can also be sensitized or desensitized positively or negatively by dyes such as cyanine, merocyanine and the like. There is no particular limitation on the wavelength range in which the sensitization or desensitization can be performed. Therefore, orthosensitization, panchromatic sensitization, helium-neon laser sensitization, argon laser sensitization, LED sensitization, and semiconductor laser sensitization can be performed, and UV sensitization and visible light reduction for a bright room can be performed. You can feel it.

The surface layer present above the emulsion layer contains physical development nuclei. As physical development nuclei, silver, antimony, bismuth, cadmium, cobalt, lead, nickel, palladium, rhodium, gold, platinum and other metal colloid fine particles, and sulfides, polysulfides, selenides of these metals, or those It may be a mixture or a mixed crystal. The physical development nucleus may or may not contain a hydrophilic binder. It may contain a copolymer of imidazole and acrylamide, a copolymer of acrylic acid and acrylamide, a hydrophilic polymer such as polyvinyl alcohol or an oligomer thereof, and the content thereof is 0.5 g / m2.
It is preferably ² or less. Further, the physical development nucleus layer may contain a developing agent such as hydroquinone, methylhydroquinone, or catechol, or a known hardener such as formalin or dichloro-s-triazine.

Each coating layer such as an undercoat layer, a silver halide emulsion layer and a physical development nucleus layer may contain some of anionic, cationic or neutral surfactants as coating aids. , An antifoggant, a thickener, an antistatic agent and the like.

As the support of the lithographic printing plate of the present invention,
Paper, a synthetic or semi-synthetic polymer film, a metal plate of aluminum, iron, or the like can be used as long as it can withstand lithographic printing. One or both surfaces of the support may be coated with one or more polymer films or metal thin films. The surface of these supports can be subjected to a surface treatment in order to improve the adhesion to the coating layer.

Particularly preferably used supports are paper coated on both sides or one side with a polyolefin polymer, a polyester film, a polyester film having a hydrophilized surface, an aluminum plate having been subjected to a surface treatment, and the like.
These supports may contain pigments for preventing halation and solid fine particles for improving the surface properties. The support may be light-transmissive so that backside exposure is possible.

The developing solution used in the present invention includes an alkaline substance such as sodium hydroxide, potassium hydroxide,
Lithium hydroxide, tribasic sodium phosphate, etc., sulfites as preservatives, silver halide solvents such as thiosulfate,
Thiocyanates, cyclic imides, 2-mercaptobenzoic acid, amines and the like, thickeners such as hydroxyethylcellulose, carboxymethylcellulose and the like, antifoggants,
For example, potassium bromide, a compound described in JP-A-47-26201, a developing agent such as hydroquinones, catechol, 1-phenyl-3-pyrazolidone, a developing modifier,
For example, it can contain a polyoxyalkylene compound, an onium compound, and the like. Further, as the developing solution, a compound or the like described in U.S. Pat. No. 3,776,728 which improves the ink running of the surface silver layer can be used.

The surface silver layer after development of the lithographic printing plate of the present invention can be converted to ink receptivity or enhanced in receptivity with any known surface treating agent. Examples of such a processing solution include JP-B-48-29723 and U.S. Pat.
21, 559 and the like. The printing method, the desensitizing solution, the humidifying solution, and the like to be used can be a commonly known method. Hereinafter, the present invention will be described with reference to Examples, but it should be understood that the present invention is not limited thereto.

[0059]

EXAMPLES The present invention will be described below with reference to examples, but of course, the present invention is not limited to these examples.

Example 1 For the purpose of hydrophilization, an undercoating layer was formed on a polyester film support which had been subjected to aqueous undercoating with an undercoating composition containing an epoxy compound as disclosed in JP-A-60-213942. Coat the emulsion layer.

<Undercoating Coating Solution> Gelatin 35 g Water 200 g Siloid (grade 308) manufactured by Fuji Divison 3 g Polylac 50 g manufactured by Mitsui Toatsu Chemicals, Inc. Carbon black dispersion (solid content 32%) 8 g Formaldehyde (30% aqueous solution) 2 g Grio Gizar (30% aqueous solution) 4g Chemical compound 6 Chemical compound Ag Chemical compound Bg Surfactant 6 ml Water is added to make the total amount 500 g.

<Emulsion coating solution> Ortho-sensitized high-contrast silver chloride emulsion 80 g Surfactant 1.2 ml Formaldehyde (30% aqueous solution) 0.05 g Compound of formula 4 Cg Compound of compound 21 Dg Water was added and the total amount was 125 g. To

Table 1 shows the addition amounts A to D of the respective compounds contained in the undercoating liquid and the emulsion coating liquid.

[0064]

[Table 1]

The coating amount is a moisture coating amount and the undercoat layer is 50 g / m
^2. The emulsion layer thereon was coated at 12.5 g / m ² at 1.5 g / m ² in terms of silver nitrate. (Samples 1 and 2). The average particle size of Fuji Divison's thyroid (grade 308) was measured by the Coulter counter method,
3.5μ. For comparison, Comparative Examples 1 to 4 were prepared based on the addition amounts of the respective compounds shown in Table 1 above, and were applied in the same manner. After drying, the mixture was heated at 50 ° C. for 2 days, and then coated with a nucleus coating solution described in Example 2 of JP-A-58-21602 (polymer containing No. 3 copolymer of acrylamide and imidazole and hydroquinone as a developing agent) To 0.
8 g / m in a proportion of ²⁾ the sodium polyacrylate (average molecular weight 260000) was prepared in the same manner a solution was added to a 0.04 g / m ^2, was coated. (Sample 1,
2, comparison 1, 2, 3, 4)

On the other hand, as a compulsory test, a sample stored for 3 to 9 days at 50 ° C. and 80% was added as a forced test to check the storage stability with time. Was used to perform image exposure and development processing. Development was carried out at 30 ° C. for 20 tons using the following diffusion transfer developer. Stabilization is performed at 25 ° C for 20 minutes with a stabilizing solution having the following composition.
Let dry.

<Diffusion Transfer Developer> Water 700 g sodium hydroxide 18 g potassium hydroxide 7 g anhydrous sodium sulfite 50 g 2-mercaptobenzoic acid 1 g uracil 10 g 2-methylaminoethanol 30 g 5-phenyl-2-mercapto-1,3,4 -Oxadiazole 0.1 g Potassium bromide 1 g Water is added to bring the total volume to 1,000 ml.

<Stabilizing Solution> Water 600 g Citric acid 10 g Sodium citrate 35 g Colloidal silica (20%) 5 g Ethylene glycol 5 g Add water to make the total volume 1,000 ml.

The printing evaluation was performed by AB Dick 350
CD (trademark of offset printing machine manufactured by AB Dick)
It was used. Regarding the printing durability, after treating each lithographic printing plate with the following desensitizing solution, using the following humidifying solution, printing was performed using New Champion Ink N manufactured by Dainippon Ink Co., Ltd. Used as ink, Dainippon Ink F
Gloss black was used, and the number of prints when image skipping due to lack of a silver image portion occurred and printing could not be performed was determined according to the following evaluation criteria. (A) 20,000 or more (B) 10,000 to 20,000 (C) 5,000 to 10,000 (D) 2,000 to 5,000 (E) Less than 2,000 Table 2 shows the results.

<Desensitizing Solution> Water 600 g Isopropyl alcohol 400 g Ethylene glycol 50 g 3-mercapto-4-acetamido-5-n-heptyl-1,2,4-triazole 1 g

<Humidifying liquid> O-phosphoric acid 10 g Nickel nitrate 5 g Sodium nitrite 5 g Ethylene glycol 100 g Colloidal silica (20% solution) 28 g Water is added to make 2,000 ml.

On the other hand, in order to check the water retention (ground stain) of the non-image area, Dai-Nippon Ink F Gloss Purple 68S was used as the ink.
Using a 2.5% aqueous solution of KPS # 500 manufactured by Lawoss Co., Ltd. as a humidifying liquid, the number of printed sheets when the AB Dick 350CD was soiled and could not be used for printing was determined according to the following evaluation criteria. (A) 3000 sheets or more (B) 1000 to 3000 sheets (C) 500 to 1000 sheets (D) 100 to 500 sheets (E) Less than 100 sheets The printing results are shown in Table 2.

[0073]

[Table 2]

As is clear from Table 2, the sample of the present invention was found to be superior in the printing durability as compared with Comparative Examples 1, 2, and 3 without changing the stain resistance performance. Also, comparisons 1, 2, 3, 4
Although there is a difference in the level of printing durability, the printing durability decreases as the number of days of forced storage increases. On the other hand, the sample of the present invention shows no improvement in the printing durability as well as the improvement in the printing durability as compared with the comparison, and is excellent in the printing durability and excellent in the printing durability even in a wide range of forced aging storage days. Turned out to be. In addition, no time dependency of the stain was observed.

Table 3 shows the results of the relative sensitivity and tone (L2) of each lithographic printing plate for the fresh sample (0 days) and the forced aging samples (3 days and 9 days).

[0076]

[Table 3]

As apparent from Table 3, Comparative Example 1
The samples 2, 3, and 4 have different levels of photographic characteristics after forced aging, but the samples of the present invention show no change in relative sensitivity and are excellent in maintaining photographic characteristics over a wide range of forced aging days. It has been found.

Example 2 In the same manner as in the preparation of Samples 1 and 2 in Example 1, Chemical Formula 7 was added to the undercoat layer, and Chemical Formulas 17, 19 and 2 were added to the emulsion layer.
Samples 3 to 6 are systems obtained by changing and combining Chemical formulas 26 and 26, respectively.

Samples 3 to 6 of the present invention did not change the stain resistance like samples 1 and 2, and the printing durability was the same level as samples 1 and 2 in Table 2. No decrease in printing durability was observed even when the number of storage days over time increased. Therefore, the sample of the present invention has not only improved printing durability but also no dependence on printing durability over time, and is excellent in printing durability.
It was found that the printing durability was excellent even over a wide range of the number of days of forced storage. In addition, no time dependency of the stain was observed.

Samples 3 to 6 of the present invention showed no change in relative sensitivity similarly to Samples 1 and 2, and the photographic characteristics were as shown in Table 3.
And the same level as that of Samples 1 and 2 above, and it was found to be excellent in maintaining photographic characteristics over a wide range of forced aging days.

Example 3 In the same manner as in the preparation of Samples 1 and 2 of Example 1, Chemical Formula 17 was added to the emulsion layer, and Chemical Formulas 3, 7, 9, and 14 were added to the undercoat layer. The changed and combined systems are referred to as Samples 7 to 10, respectively.

Samples 7 to 10 of the present invention did not change the stain resistance similarly to Samples 1 and 2, and the printing durability was at the same level as Samples 1 and 2 in Table 2. No decrease in printing durability was observed even when the number of storage days over time increased. Therefore, the sample of the present invention has not only improved printing durability but also no dependence on printing durability over time, and is excellent in printing durability.
It was found that the printing durability was excellent even over a wide range of the number of days of forced storage. In addition, no time dependency of the stain was observed.

Samples 7 to 10 of the present invention had no change in relative sensitivity similarly to Sample 1, had the same photographic characteristics as Samples 1 and 2 in Table 3, and exhibited a wide range of forced aging days. It turned out to be excellent to maintain.

Example 4 The emulsion layers were prepared in the same manner as in Samples 1 and 2 of Example 1 except that the emulsion layers represented by Chemical Formulas 17 and 3, Chemical Formulas 17 and 7, Chemical Formulas 17 and 10, and Chemical Formulas 17 and 15 were prepared. Combine the two compounds,
Samples 11 to 14 are systems in which Chemical Formula 7 is added to the undercoat layer, that is, a system in which two kinds of undercoat layers are combined with one kind of each compound in the emulsion layer.

Samples 11 to 14 of the present invention did not change the stain resistance similarly to Samples 1 and 2, and the printing durability was at the same level as Samples 1 and 2 in Table 2. No decrease in printing durability was observed even when the number of storage days over time increased. Therefore, the sample of the present invention has not only improved printing durability but also no dependence on printing durability over time, and is excellent in printing durability.
It was found that the printing durability was excellent even over a wide range of the number of days of forced storage. In addition, no time dependency of the stain was observed.

Samples 11 to 14 of the present invention did not show any change in relative sensitivity similarly to Samples 1 and 2, had the same photographic characteristics as Samples 1 and 2 in Table 3, and exhibited a wide range of forced aging days. It turned out that it was excellent in maintaining characteristics.

Example 5 In the same manner as in the preparation conditions of Samples 1 and 2 of Example 1, the undercoat layer was made of Chemical Formulas 17 and 3, Chemical Formulas 17 and 7, Chemical Formulas 17 and 10, and Chemical Formulas 17 and 13 Each of the two types of compounds are combined,
Samples 15 to 18 were obtained by adding Chemical Formula 17 to the emulsion layer, that is, a system in which two kinds of emulsion layers were combined with one kind of each compound in the undercoat layer.

Samples 15 to 18 of the present invention have the same level of printing durability as Samples 1 and 2 in Table 2 without changing the stain resistance as in Sample 1. No decrease in printing durability was observed even when the number of days increased.
Therefore, it was found that the sample of the present invention shows not only the improvement of the printing durability but also the aging dependency of the printing durability, excellent printing stability, and excellent printing durability even in a wide range of forced aging storage days. did. In addition, no time dependency of the stain was observed.

Samples 15 to 18 of the present invention showed no change in relative sensitivity similarly to Samples 1 and 2 and had the same photographic characteristics as Samples 1 and 2 in Table 3 and showed a wide range of forced aging days. It turned out that it was excellent in maintaining characteristics.

[0090]

According to the present invention, it is possible to provide a lithographic printing plate using a silver complex salt diffusion transfer method, which is excellent in stain resistance, printing durability and time dependency.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-62-239161 (JP, A) JP-A-1-237552 (JP, A) JP-A-63-198064 (JP, A) JP-A-56-239 110927 (JP, A) JP-A-4-323659 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03F 7/07 G03F 7/00 503

Claims (1)

(57) [Claims] 1. A lithographic printing plate comprising a support and at least one undercoat layer, a silver halide emulsion layer and a physical development nucleus layer sequentially coated thereon. A lithographic printing plate comprising a compound of the general formula represented by the formula (1) in a layer and a compound of the general formula represented by the formula (2) in the silver halide emulsion layer. . Embedded image (In the formula, R1 and R2 represent a hydrogen atom, an alkyl group, an aryl group, an aralkyl group, an alkenyl group, an amino group, an acylamide group, and a sulfonamide group, respectively.) (Wherein, M ⁺ represents a hydrogen ion, an alkali metal ion, or an ammonium ion. R3, R4, R5, and R6
Is a hydrogen atom, an alkyl group, an alkenyl group, an aralkyl group, an aryl group, a halogen atom, an alkoxy group,
Hydroxy, amino, carboxy, sulfone,
It represents an alkoxycarbonyl group, an acylamide group, or a sulfonamide group. R3, R4, R5 and R6 may be linked to form a ring. )