JPS60123845A - Laser light sensitive lithographic plate material - Google Patents

Abstract

PURPOSE:To enhance sensitivity to laser beams by using a specified sensitizing dye for a silver salt diffusion transfer offset printing plate. CONSTITUTION:A support is coated with an antihalation layer, and a silver halide emulsion layer, and further, with a physical development nucleus layer in this order from the support to form a lithographic plate material. This emulsion layer is composed of >=98mol% silver chloride grains or the total silver halide grains, and further contains a sensitizing dye represented by the formula in which A is 1-4C alkyl; R<1>, R<2> are each lower alkyl, hydroxyalkyl, sulfoalkyl, or carboxyalkyl; Y1, Y2 are each O, S, or Se; Z<1>, Z<2> are each a benzene or naphthalene ring; X is an alkali metal or NH4; and n is 0 or 1. The obtained material is especially suitable for a helium-neon laser and an argon laser.

Description

[Detailed description of the invention]

[Field of Application of the Invention] The present invention relates to a silver salt offset printing plate.
Specifically, the present invention relates to a material for laser plate making that has excellent properties against laser light in off-cent printing plates using the silver salt diffusion transfer method. Photolithographic technology has made remarkable progress in recent years, and printing operations are becoming faster and more streamlined. One of these is plate-making technology using laser light.
Laser plate making is a plate making method that makes use of the characteristics of laser light, which has high energy density and can be modulated, by utilizing the high energy density and modulation characteristics of the laser beam to obtain a printing plate directly from the original or the original plate. In other words, it has three functions: a facsimile machine, an exposure machine, and a plate-making camera. Laser plate making is attracting attention as a technology that will see significant application and development in the future, as it satisfies the industry's needs for resource conservation, pollution-free production, and lower plate-making costs. Currently, the most widely used laser beams include helium-neon, helium-cadmium, argon, krypton, carbon dioxide, ruby, etc. as the 6II1 components of laser oscillation, and recently semiconductor lasers have also appeared. LEDs (light emitting diodes) similar to this are also being used. Among these oscillation systems, those that are most compatible with lithographic printing materials are helium-neon and argon gas lasers, which are currently an innovation in the industry. [Prior Art] Many methods have been known for making lithographic printing plates using the silver salt diffusion transfer method, and a representative example is a method in which a photosensitive element and a printing image element are integrated.
Methods described in Japanese Patent Publications No. 42453 and No. 48-30562 are known. These lithographic printing plates using the silver salt diffusion transfer method are usually
A roll using paper or film base as a support was photographed and developed using a plate-making machine to obtain a printing QI]7 plate. However, when photographing with a camera using such an optical system, the image quality inevitably deteriorates due to lens characteristics or light scattering on the printing plate, and as a result, the image resolution of printed matter is currently reduced. Met. Under these circumstances, direct plate-making technology using laser light was developed, and by scanning and exposing the plate directly without going through a lens system, it became possible to improve the resolution of the image line compared to the conventional method. became. Furthermore, it is now possible to store the information read from the manuscript, making it easier to make corrections, layouts, etc., and the plate-making process is currently experiencing significant technological innovation. In response to such progress in laser engraving technology, the lithographic printing materials that apply the silver salt diffusion transfer method are not always satisfactory; for example, the image quality may be poor due to lack of sensitivity and contrast to various laser beams. In reality, laser engraving machines have not been fully utilized due to deterioration or the need for long exposure times. The second purpose of the present invention is to provide a lithographic printing material that is ink-receptive to a silver image produced by a laser beam, and has characteristics of high sensitivity to laser light and high contrast. The object of the present invention is to provide a printing material capable of producing printed matter free of fine lines or fine halftone dots and free of surface stains. [Specific Structure of the Invention] The object of the present invention as described above is to coat the upper layer of a norsine prevention layer and a silver halide emulsion layer in layers from the support side.
In a silver salt diffusion transfer lithographic printing material having a structure coated with a physical development nucleus layer, the silver halide emulsion layer has a silver halide composition of at least 98 mol% of silver chloride grains, and the halogen This can be achieved by incorporating at least one kind of compound represented by the following general formula [I] into the silveride emulsion. (However, A in the formula is a lower alkyl group having 1 to 4 carbon atoms,
R' and Bt represent the same or different lower alkyl group, hydroxyalkyl group, sulfoalkyl group, or carboxyalkyl group. Yl and Y2 are an oxygen atom, a sulfur atom and a selenium atom, respectively, and Z' and 'Z' represent a condensate of a benzene ring or a naphthalene ring which may have a substituent. X is an alkali metal atom, an ammonium group , n is O or l
represents. ) Next, we will list specific examples of the compound represented by −r=2 above,
The present invention is not limited to this. Compound Examples (CH*) tCOOH (CH
Written by r''' The Cyanjne Dyes an
d Re1ated Compounds”
1964. Infer-8science Public
It can be synthesized according to the method described in J. Shers, or the method described in British Patent No. 742.112 and US Pat. No. 2.213.238. In order to add the compound to the silver halide emulsion in the method of the present invention, it is used after being dissolved in water or a hydrophilic solvent such as methanol or ethanol. Addition time: 1 tl+t:, 1 may be added arbitrarily, but preferably before or after chemical ripening. The amount added is 10 to 500 μg per mole of silver halide.
Enclosed is sufficient. The printing material of the present invention thus obtained has compatibility with various laser beams as described above, and among them, application to helium-neon and argon lasers is preferred. Also, semiconductor laser or light emitting diode [LED]
It is also possible to respond to The present invention will be explained in more detail below. The lithographic printing material for laser light of the present invention (hereinafter simply referred to as the printing material of the present invention) has an antihalation layer and a photosensitive silver halide emulsion layer on a support, and a physical development nucleus layer thereon, as described above. Although the basic layer structure includes the above-mentioned layers, an intermediate layer may be provided between each of the above-mentioned layers. In the printing material of the present invention, it is preferable that in the above-mentioned layer structure, a photosensitive silver halide emulsion layer is provided with a physical development nucleus layer directly on top of the photosensitive silver halide emulsion layer. In the present invention, the L/
The -4/Yon prevention layer is, for example, a hydrophilic compound layer in which carbon black, dyes, pigments, etc. are dispersed. The silver halide composition of the photosensitive silver halide emulsion layer according to the present invention is preferably substantially cubic crystal silver halide containing at least 98 mol % of silver chloride. Such a photosensitive silver halide emulsion containing silver halide may be a 4° silver chlorobromide or silver chloroiodobromide emulsion containing a trace amount of silver iodide or silver bromide; 100
It is preferable to use a pure silver chloride agent containing mol %. A method for preparing such a silver halide emulsion may be a method well known in the art, such as a single jet method, a double jet method, or a controlled jet method. Since the silver halide emulsion according to the present invention is made up of at least 98 mol% silver chloride grains as described above, unless the excess halide ion concentration at the time of grain formation is extremely high, it cannot be used in a normal mixing method. Silver halide grains having a cubic crystal shape can be formed by this process. The average grain size of the silver halide in the silver halide emulsion is preferably in the range of about 0.05μ to 2.0μ. In addition, this silver germide emulsion has a concentration of % after grain formation;
Soluble salts are removed in a conventional manner. The desalted emulsion can be chemically sensitized using a sulfur sensitizer such as thiosulfate, allylthiocarbamide, thiourea, γlylisothiacyanate, and the like. Additionally, U.S. Patent No. 2.399
．． No. 083, No. 2.597.856 No. 2.597
．． Gold compounds described in US Pat. No. 915, etc., U.S. Pat.
．． Platinum, palladium, iridium described in No. 448.060, No. 2.540.086, No. 2.566, 245, No. 2.566, 263, No. 2.598°079 The above emulsion can be ripened using noble metal salts such as rhodium, ruthenium, etc. The hydrophilic binder advantageously used in the silver halide emulsion according to the present invention is gelatin, and some or all of the gelatin can be substituted with synthetic polymers such as polyvinyl alfur, poly-N-vinyl pyrrolidone, etc. A substituted acrylic acid copolymer, a copolymer of methyl vinyl ether and maleic anhydride, or a compound substituted with a cellulose derivative, a gelatin derivative, etc. can be used. Furthermore, various compounds may be added to the emulsion for the purpose of stabilizing it during the manufacturing process or storage, or preventing the occurrence of fog during development. Furthermore, in addition to the above compounds, for example, sensitizers, hardeners, surfactants, etc. can be used as appropriate. For specific compound examples, see "Product Licensing Index" Vol. 92, A9232, pp. 107-110. , T ~
XIII, XVI to XVII, OK (1971,
December). The photosensitive silver halide emulsion layer according to the present invention can be formed by coating the emulsion thus prepared as a layer on the antihalation layer by a known method. Next, regarding the development nuclei of the physical development nucleus layer according to the present invention, for example, water-soluble noble metal salts such as gold, silver, platinum, and palladium, or zinc, cadmium, nickel, cobalt, iron, chromium, and tin. , metal colloids obtained by reducing heavy metals such as antimony, bismuth, etc.
Alternatively, development nuclei obtained by mixing these water-soluble metal salts, such as nitrates, acetates, borates, chlorides, hydroxides, etc., with water-soluble sulfides, such as sodium sulfide, etc. can be used. As for the type of hydrophilic binder used in the physical development nucleus layer according to the present invention, the same kind of hydrophilic polymer substances as those used in the photosensitive silver halide emulsion layer mentioned above are applicable, but gelatin, polyvinyl aluminium, etc. :】-ru or methyl vinyl ether and anhydrous macer

[-A copolymer of inic acid is preferred, and a combination of these may also be used. Are these hydrophilic? The amount of the binder is not necessarily uniform depending on the type of noble metal or binder, but it ranges from 30% to 100% by weight relative to the physical development nuclei. The physical development nucleus layer described above is preferably coated directly on the photosensitive silver halide emulsion layer. As the support for the printing material according to the present invention, for example,
Irate film, cellulose acetate film,
Examples include cellulose acetate butyrate film, polystyrene film, polyethylene phthalate film, polycarbonate film, laminates thereof, and paper. In addition, baryta or α-olefin polymers, especially polyethylene, polypropylene, ethylene butylene copolymers, etc. α-olefins having 2 to 0 carbon atoms 1)
Paper coated with or laminated with paint, Special Publication 1976-19
068, the surface of which is roughened to enhance adhesion to other polymeric substances, or a support using a surface roughening method described in Japanese Patent Publication No. 56-135840. be able to. Also, in order to reduce plate elongation, a support in which metal foil, for example aluminum foil, is laminated to paper can be used. Colloidal silica can also be used in coatings applied to polyolefin surfaces for the purpose of improving adhesion to polyolefin-coated surfaces or improving printability. Regarding these four methods, the method described in US Pat. No. 3,161,519 may be followed. In order to strengthen the adhesion between the support and the coating layer, the surface of the support may be subjected to a preliminary treatment such as corona discharge, ultraviolet irradiation, flame treatment, or the like. Regarding corona discharge, U.S. Patent No. 2.0
The method described in No. 18.189 is representative. The hardening of the silver halide emulsion and/or other constituent layers can be carried out according to conventional methods. Examples of curing agents include aldehyde compounds such as formaldehyde and glutaraldehyde, ketone compounds such as diacetyl and cyclopentanedione, bis(2-chloroethyl urea),
2-hydroxy-4,6-dichloro-1',3,5-triazine, and other U.S. Pat. No. 3.288.775,
No. 2.732.303, British Patent No. 974.723
Compounds containing reactive halogens, divinyl sulfone, 5-acetyl-1゜3-diacryloylhexahydro-1,3,5-) as shown in the specifications of No. 1, No. 1.167 and No. 207, etc. Reazine and other U.S. Patent No. 3
．． No. 635.718, No. 3.232.763, No. 3.490.911, No. 3.642.486, British Patent No. 994.869, etc. Compounds with reactive olefins, N-hydroxymethylphthalimide, Sono et al. U.S. Patent No. 2.732
．． N-methylol compounds as shown in U.S. Pat. No. 316 and U.S. Pat. No. 2.586.168; isocyanates as shown in U.S. Pat. No. 3,017.280, U.S. Pat.
No. 94, No. 2.725.295, etc. shown in each specification? Acid derivatives such as those described in U.S. Pat. No. 3.100.7
Carbodiimide compounds as shown in US Pat. No. 04, etc., epoxy compounds as shown in US Pat. No. 3.091.5:37, US Pat. No. 3.321.313. No. 3,543.292, inoxazole compounds i, halogenocarboxaldehydes such as mucochloric acid, dioxane derivatives such as dihydroxydioxane and dichlorodioxane, or inorganic Examples of hardening agents include chrome light pan and zirconium sulfate. Also, in place of the above-mentioned compounds, compounds in the form of B-L-cursor, such as alkali metal bisulfite aldehyde adducts, H-H. Methylyl derivatives of toin, tertiary aliphatic nitroalcohols, and the like may also be used. If necessary, known surfactants may be added alone or in combination to the constituent layers of the printing material of the present invention. These may be used as fabric aids, but may also be used for other purposes, such as emulsifying and dispersing, promoting development, improving other photographic properties, adjusting the charge series, preventing static electricity, etc. These surfactants include natural products such as saponin, anionic or nonionic surfactants such as alkylene oxide type, glycerin type, and glycidol type, higher alkylamines, 49th ammonium salts, pyridine and other heterocycles, and phosphonium. or cationic surfactants such as sulfonium, anionic surfactants with acidic groups such as carboxylic acids, sulfonic acids, phosphoric acids, sulfuric esters, phosphorus 9x esters, amino/acid 11i, aminosulfonic acids,
Includes ampholytic active agents such as sulfuric acid or phosphoric acid esters of Amino 711L/Fu-A/. Some examples of surfactant compounds that can be used include U.S. Pat.
0゜472, 2.288.226, 2.7
No. 39891, No. 3.068.101, No. 3.1
58.484, same No. 3゜201, 253, same No. 3,
No. 210,191, No. 3.294.540, No. 3
．． No. 415.649, No. 3.441.413, No. 3, 442.654, No. 3.475.774, No. 3.545°574, British Patent No. 1.077, 31
No. 7, No. 1.198゜450, as well as Ryohei Oda et al.'s "Synthesis of Surfactants and Their Applications" (Maki Shoten, 1964) and A. W. Berry's "Surf Us Active Agents". -gent” (Interscience Publications, Inc., 1958),
It is described in "Encyclopetia of Active Agents Volume 2" by J. P. Sisley (Chemical Vapri, Shcompany, 1964). The printing materials of the present invention may be used as filter dyes or anti-irradiation dyes as described in US Pat. No. 2,274,78.
No. 2, No. 2.527.583, No. 2.956.8
No. 79, No. 3.177, No. 078, No. 3.252.
It may contain the compounds described in each specification of No. 921 and Japanese Patent Publication No. 39-22069. These dyes are
If necessary, it may be mordanted by the method described in US Pat. No. 3,282,699. In addition, a colored layer such as a pigment (for example, lamp black, carbon black, 7-star plastic, ultramarine, malachite green, crystal violet) can also be used as the anti-halation layer. The constituent layers of the printing material according to the present invention can be coated on the above-mentioned support using coating methods well known in the art. For example, there are the Depp method, the Air Knife method, and the Extrusillon Doctor method.
Particularly preferred is the bead coating method described in U.S. Pat. No. 2,761,791. A silver halide developing agent may be incorporated in the constituent layers of the printing material according to the present invention. In this case, development after exposure can be carried out by activation treatment using an alkaline aqueous solution. The developing agent can be contained in the silver halide emulsion layer or its adjacent layer (undercoat layer, intermediate layer, or anti-halation layer). Note that the developing agent may also be contained in the developing solution. Specific compounds for the developer include polyhydroxybenzenes such as hydroquinone, catechol, chlorohydroquinone, pyrogallol, bromohydroquinone, isopropylhydroquinone, toluhydroquinone, methylhydroquinone, 2,3-dichlorohydroquinone, and 2,5-dichlorohydroquinone. −
Dimethylhydroquinone, 2,3-dichlorohydroquinone, 1,4-dihydroxy-2-acetophenone, 2,
5-dimethylhydroquinone, 4-phenylcatechol,
4-phthylcatefur, 4-n-butylpyrogallol, 4,5-dibromocatechol, 2,5-diethylhydroquinone, 2,5-penzoylaminohydroxyne,
Included are 4-benzyloxycatechol, 4-n-butoxycatechol, and the like. Among these, hydroquinone and methylhydroquinone are particularly preferably used. In addition, other developing agents include "-pyrazolidone compounds such as 1-phenyl-3-pyrazolidone, 1-pyrazolidone,
p-) Zyl-3-pyrazolidone, 1-phenyl-4-
Methyl-3-pyrazolidone, 1-phenyl-4,4-dimethyl-3-pyrazolidone, 1-p-chlorophenyl-
3-pyrazolidone, 1-p-methoxyphenyl-3-pyrazolidone, 1-phenyl-2-a7thyl-3-pyrazolidone, 1-phenyl-5,5-dimethyl-3-pyrano'J)', 1-o -chlorophenyl-4-methyl-4
-ethyl-3-pyrazolidone, l-m-acetamidophenyl-4,4-diethyl-3-pyrazolidone, 1.5-
diphenyl-3-pyrazolidone, 1-(m-tolyl)-
5-phenyl-3-pyrazolidone, 4,4-dihydroxymethyl-1-phenyl-3-pyrazolidone, 4,4-
dihydroxymethyl-1-tolyl-3-pyrazolidone,
4-Hydroxymethyl-1-phenyl-3-hyrazolidone, 4-hydroxymethyl-4-methyl-1-(p-
Chlorphenyl)-3-pyrazolidone and the like are included. Examples of aminophenols include p-(methylamino)phenol, p-aminophenol, 2,4-diaminophenol, p-(benzylamino)phenol, and 2-methyl-4-aminophenol. The above developing agents can be used alone or in combination. Particularly preferred is a combination of a polyhydroxybenzene compound and a 3-pyrazolidone compound. The amount of the developing agent used in the constituent layers is not uniform, but it is preferably in the range of 0.0019 to 1 g per layer, and in the case of a silver halide emulsion layer, it is 0.01 g to 3 g per silver halide layer. ! ? Used within the range of Furthermore, if necessary, a compound called a complexing agent that tends to form a soluble silver complex salt with silver halide in the unexposed area can be included in the constituent layers to advantageously accelerate physical development. . Examples of complexing agents include thiosulfates, thiocyanates, amine thiosulfates as described in U.S. Pat. No. 3,169,962, or U.S. Pat.
Cyclic imides described in specification No. 857.276, Japanese Patent Publication No. 4
A mercapto compound described in Japanese Patent Publication No. 6-11957 can be included. The above-described developing agents may be added to the coating solution after being dissolved in water or a hydrophilic solvent such as methanol, or may be added after being dissolved in a high-boiling organic solvent or a low-boiling organic solvent. As a high boiling point organic solvent, the boiling point is generally about 180℃.
Among the above, there are, for example, alkyl esters of heptatalic acid such as ethyl phthalate and n-butyl phthalate, and phosphorus esters such as tricresyl phospade. In addition, the low boiling point organic solvent generally has a boiling point between about 150°C and 150°C, such as lower alkyl acetates such as ethyl acetate and butyl acetate. The dissolved developing agent may be dispersed in the hydrophilic colloid by any known method. When added to the constituent layers of the printing material according to the present invention, it can be added directly to any layer or dissolved in gelatin or a synthetic polymer compound such as polyvinyl alcohol, polyvinyl pyrrolidone, US Patent No. 3
．． Examples include alkyl acrylates, sulfoalkyl acrylates, and acrylic acid fupolymers described in No. 488.708. When developing or image processing the printing material of the present invention, a processing liquid containing a glaze may be used. Typical examples include alkaline agents (e.g. alkali metal or ammonium hydroxides, carbonates, phosphorus salts), pH adjusting or buffering agents (e.g. weak acids and bases such as acetic acid, ?Mt acids, salts), development accelerators (for example, various pyridinium compounds and cationic compounds described in U.S. Pat. Nos. 2,648,604 and 3,671,247, potassium nitrate, sodium nitrate,
U.S. Patent No. 2.533.990, U.S. Patent No. 2.577, 1
Polyethylene glycol condensates and their derivatives as described in British Patent No. 27, British Patent No. 2.950.970, etc., British Patent No. 1.020.033 and British Patent No. 1.020.
．． Anionic compounds such as polythioethers as typified by the compound described in US Pat. No. 032, sulfide ester polymer compounds as typified by the compound described in US Pat. Other organic amines such as pyridine, ethanolamine, cyclic amines, benzyl alfur, hydrazines, etc.), antifoggants (such as alkali chloride, alkali bromide, alkali iodide, U.S. Pat. No. 2.496.940, U.S. Pat. In addition to the nitrobenzimidazoles described in 2.656゜271, mercaptobenzimidazole,
5-Methylbenztriazole, 1-phenyl-5-mercaptotetrazole, U.S. Pat. No. 3,113°864
No. 3.342.596, No. 3.295.97
No. 6, No. 3.615.522, No. 3.597.1
Compounds for rapid processing liquids described in the specification of No. 99 etc., thiosulfonyl compounds described in the specification of British Patent No. 972゜211, or phenazine as described in Japanese Patent Publication No. 46-41675. N-oxides, other
Fogging suppressants described in "Science Photography Handbook" Vol. 29-47), and other U.S. Patent No. 3.161
No. 513, No. 3.161.514, British Patent No. 1
．． 030°442, 1.144.481 and 1.251.558, as well as preservatives (e.g. sulfites, acid sulfites, hydroxylamine hydrochloride, Form sulfide, alkanolamine sulfide additives, etc.). In addition, metal sequestering agents such as sodium hexametaphosphate and enanthyl diaminetetraacetic acid, wetting agents such as sahonin and ethylene glycol, etc. can be used. Furthermore, the developing solution contains silver halide solvents such as sodium thiosulfate, sodium thiocyanate, potassium thiocyanate, alkanolamines, cyclic imines, alkyl-substituted amino alcohols, thiourea, thiosalicylic acid, and thiosulfuric acid in an alkaline solution. For example, it may contain 5-methylcarbamoylthiosalicylic acid, which can produce . If the printing material according to the invention needs to be stopped after development, a neutralizing solution can be used. This neutralizing solution is a normal acid stop bath with a pH of approximately 3.0 to 8.0.
It may be adjusted to This neutralizing solution may contain a water softener, a pH adjuster, a buffer, a hardening agent, etc., and may also contain colloidal silica or polyols for the purpose of eliminating ink stains on the printing plate being processed. etc. may be added. After the printing material is treated as described above to obtain a plate, various post-treatments can be carried out for the purpose of improving printability. For example, for the purpose of improving ink adhesion, US Pat. No. 3,592. '647, same No. 3゜490, 90
No. 6, Specification No. 3.161.508, Special Publication No. 1973-
1091. (No. 1, No. 4.8-29723, No. 51-
No. 15762 and the method described in Japanese Patent No. 52-15762. Hereinafter, the present invention will be explained in more detail with reference to Examples. Example 1 A coating solution having the following composition was applied as an antihalation layer onto a polyethylene-coated paper (corona discharge treated) having a thickness of 160.9/m by a dipping method. [Composition of coating liquid for antihalation layer] a-t! Funan 45y (finished with water 400 ml, finished with water 300 mer formalin (35% aqueous solution) 3 ml (finished with water 100 ml) After dissolving and dispersing the above liquids a, b and c, respectively, After sequentially mixing, and then adding liquid d, a final coating solution was prepared in 11. After coating the above coating solution as a layer, layer 1 was coated with silver halide milk ff1a1 prepared as follows. The photosensitive silver halide emulsion was a regular double diluted emulsion. It was a pure silver chloride emulsion prepared by the atto method, with a sulfur content of 11.
,'. After chemical sensitization with a stabilizer, exemplified compounds according to the present invention and comparative compounds (a) and [b] were added as shown in Table 1 below, and then 4-hydroxy- An appropriate amount of 6-methyl-1,3,3a, 7-chitrazaindene was added. Comparative compound [a] Comparative compound (b) C2H5 Subsequently, an appropriate amount of isoamyl-n-decylsulfosuccinic acid sodium salt was added as a coating aid. An emulsion coating liquid was prepared.The amount of coated silver was 0.8 g/m'' in terms of silver. After seasoning the two-layer coated sample obtained above (left at 40°C and 45% RH for 3 days),
A physical development nucleus layer coating solution having the following composition was applied to the upper layer of the coating layer by a bead coating method and dried to obtain a lithographic printing material sample according to the present invention. [Preparation of coating solution for physical development nucleus layer] 1. Finish with water 50 ml (NaBH+ 0.81 1. Finish with water nitrate 200 ml) After mixing the above solutions a and b at room temperature, apply C under strong stirring.
The solution was added for reduction, and after 10 minutes, the total amount was reduced to ]1 to obtain a stock solution of physical development nuclei. An appropriate amount of saponin was added to this physical development nucleus stock solution to prepare a coating solution, and the coating solution was coated to give an amount of 2.5 m9 per 1771 inches in terms of gold.The obtained printing plate was made by the following method. Plate making method Two cylindrical scanning facsimile transmitters with neutral gray wedges, dot wedges (120, 93 finch) and photocopy
A helium-neon laser (10
mw/emission peak 632°01) Scanning exposure was performed by modulating the light output of the light source. Subsequently, the printing material was developed with the following processing solution. Developer (alkaline activation bath) Processing time 30'C3
0 seconds anhydrous sodium sulfite 50g Potassium hydroxide 30g Hypo 2.0g Stop solution (stabilizing liquid) made to 11 with water Treatment time Sodium citrate heated at 30°C 109 Citric acid 1.0g Ethylene glycol 10g Finished to 11 with water - The obtained IJ characteristics are shown in Table 1 below. Table 1 Contrast in the table is expressed by gamma in the edges and edges, and halftone dots and character quality are expressed using a 5-level scale with 5 being the best for the sharpness of the image observed with a magnifying glass. This is what I did. As shown in Table 1 above, samples A1 to A6 produced by the method of the present invention all have better line drawing properties than comparative samples &7. A plate with a sharp image without exposure blurring even under vibration was obtained. . Example 2 A sample according to the present invention and a comparative sample were prepared in exactly the same manner as in Example 1. However, the silver halide emulsions used and the compounds added thereto are as shown in Table 2 below. The obtained E material was used in Example 1.
Scanning exposure was performed on the plate using a 10 mw argon laser as a light source. Next, the exposed sample was developed in exactly the same manner as in Example 1 to form a diffusion transfer image. Next, the plate surface was lightly wiped with a lipophilic liquid having the composition shown below, and then printing was carried out using a printing machine equipped with a device for supplying a dampening liquid having the same composition as shown below. Lipophilic liquid composition 1-p-ethoxyphenyl-5-mercaptotetrazole 0.19 Ethanol 101114 Isopropatol 20 ml Moisturizing liquid composition finished with water to 100 ml Glycerol 10111/! Kotetrasilic acid (20% liquid) 3tnt boric acid 0.
The results obtained are shown in Table 2 below. Note that the ground stains in the table are indicated by the number of printed sheets where the ground stains occurred at the beginning of printing. The results in Table 2 also show that the composition of the silver halide emulsion consists of 98 mol% or more of silver chloride grains by the method of the present invention,
It is also seen that excellent printing results can be obtained by incorporating the compound according to the present invention. Incidentally, a printing test was similarly conducted for the samples of Example 1, and as a result, all of the samples related to the present invention reproduced the image quality at the time of plate making as they were, and obtained high-quality printed matter. [Effects of the Invention] As is clear from the above examples, the present invention provides a lithographic printing plate that is highly sensitive to laser light, has excellent line drawing properties, and has printing characteristics without smudging. can do. Agent Yoshimi Kuwahara

Claims (1)

[Claims] In a silver salt diffusion transfer lithographic printing material having a structure in which an antihalation layer and a silver halide emulsion layer are layered and coated from the support side, and then a physical development nucleus layer is coated on that layer, The silver halide composition consists of at least 98 mol% or more of silver chloride grains, and the silver halide emulsion has the following general formula [
(2) A lithographic printing material for laser light, characterized in that it contains at least one compound represented by [2]. General 2m (However, A in the formula is a lower alkyl group having 1 to 4 carbon atoms.
R' and R2 are the same or different lower argyl groups,
Represents a hydroxyalkyl group, a sulfoalkyl group, or a carboxyalkyl group. Yl and Y2 are an oxygen atom, a sulfur atom and a selenium atom, respectively, and Zl and Z2 represent a condensate of a benzene ring and a naphthalene ring which may have a substituent. X is alkali gold 1.1 (atom or ammonium group, n represents O or 1)