JP3368154B2 - Plate making method of lithographic printing plate - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for making a lithographic printing plate using a silver complex salt diffusion transfer method using an aluminum plate as a support. 2. Description of the Related Art A lithographic printing plate using a silver complex salt diffusion transfer method (DTR method) is described in "Photographic Silver" published by Focal Press, London New York (1972), by Andrelot and Edith Weide. Some examples are described in "Halide 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 type 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 the 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. The exposed silver image area and the non-image area are coated with a finishing solution containing a protective colloid such as gum arabic, dextrin, carboxymethylcellulose, polystyrene sulfonic acid and the like for protection. A so-called gumming process is performed. This finishing solution is also called a fixing solution or a finishing solution, and generally contains a compound that makes the silver image area lipophilic (hereinafter, referred to as a lipophilic agent). One of the serious problems in the method of making an aluminum lithographic printing plate is that the silver image portion at the start of printing has poor ink acceptability. In order to solve such a problem, U.S. Pat. No. 4,567,131 discloses that a protease and a lipophilic agent are allowed to act in a finishing treatment step. Although the ink receptivity has been improved to some extent by the above-mentioned conventional method, the ink receptivity may be insufficient depending on changes in printing conditions, for example, changes in the type of printing press or ink. Stable and high ink acceptability has not yet been obtained. Therefore, further improvements are desired. [0010] An object of the present invention is to solve the above-mentioned problems and to provide a plate making method for an aluminum lithographic printing plate having excellent ink acceptability in a stable manner. [0011] The object of the present invention is to provide a lithographic printing material having a physical development nucleus between an aluminum support and a silver halide emulsion layer, comprising:
In a method of making a lithographic printing plate using a metallic silver image portion as an ink receptive material, which is processed in the order of a washing liquid and a finishing liquid, a compound that makes the metallic silver image portion lipophilic in at least one of the above-mentioned processes. And a lithographic printing plate making method characterized in that the washing solution contains a protease. In the process of completing the present invention, the inventor has conducted research based on the following basic concept. That is, in order to improve the ink receptivity of the silver image portion, (1) how to increase the lipophilicity of the silver image portion, and (2) a substance which inhibits the lipophilicity of the silver image portion, especially a hydrophilic property such as gelatin. This means that the two factors of how to completely remove the substance are simultaneously satisfied. The above (1) can be obtained by allowing a lipophilic agent to act in the plate making process. The above (2) is the point where the present inventor struggled the most. As described above, U.S. Pat. No. 4,567,131 discloses that a proteolytic enzyme is allowed to act in a finishing treatment after washing and removal of a silver halide emulsion layer. The nature has not been obtained. The problem with this method is that, from the viewpoint of the basic concept, it is considered that the removal of hydrophilic substances such as gelatin on the silver image is still insufficient. As a result of intensive studies, the present inventors have found that the use of a proteolytic enzyme in the water washing step stably improves ink receptivity. This is because the washing process for removing the silver halide emulsion layer is performed at a relatively high temperature and a large amount of washing solution is supplied to the silver image portion with a relatively strong impact. Decomposing enzymes work,
As a result, it is considered that a hydrophilic substance such as gelatin can be more completely removed. In the present invention, the lipophilic agent may be present at any position in the plate making process, but is preferably present at a plurality of positions. Hereinafter, the present invention will be described in detail.
As the protease used in the present invention (hereinafter referred to as an enzyme), any known vegetable or animal enzyme capable of hydrolyzing proteins such as gelatin can be used. For example, pepsin, rennin, trypsin, chymotrypsin, cathepsin, papain, ficin, thrombin, renin, collagenase, bromelain, bacterial proteinase (for example, bioprase manufactured by Nagase & Co., Ltd.) and the like can be mentioned. Among these, trypsin, papain, ficin, and bacterial proteinase are particularly preferred. The appropriate content of the enzyme in the washing solution is about 0.5 to 50 g / liter. It is preferable that the enzyme is further contained in a finishing solution. The content of the enzyme in the finishing solution is 0.5 to 50.
About g / liter is appropriate. The compound (lipophilic agent) for making the silver image portion lipophilic used in the present invention is described in "Photographic Silver," by Andrelot and Edith Weide, published by Focal Press, London, New York (1972). Halide Diffusion Processes ",
And the compounds described on pages 105 and 106. For example, there are a compound having a mercapto group or a thione group and a quaternary ammonium compound. In the present invention, a compound having a mercapto group or a thione group is preferably used. Particularly preferred are nitrogen-containing heterocyclic compounds having a mercapto group or a thione group.
No. 29723, and JP-A-58-127928. Specific examples will be described below, but the present invention is not limited thereto. 2-mercapto-4-phenylimidazole, 2-mercapto-1-benzylimidazole,
Mercapto-benzimidazole, 1-ethyl-2-mercapto-benzimidazole, 2-mercapto-1-
Butyl-benzimidazole, 1,3-diethyl-benzimidazoline-2-thione, 1,3-dibenzyl-imidazolidin-2-thione, 2,2'-dimercapto-
1,1'-decamethylene-diimidazoline, 2-mercapto-4-phenylthiazole, 2-mercapto-benzothiazole, 2-mercaptonaphthothiazole, 3-
Ethyl-benzothiazoline-2-thione, 3-dodecyl-benzothiazoline-2-thione, 2-mercapto-
4,5-diphenyloxazole, 2-mercaptobenzoxazole, 3-pentyl-benzoxazoline-
2-thione, 1-phenyl-3-methylpyrazoline-5
-Thione, 3-mercapto-4-allyl-5-pentadecyl-1,2,4-triazole, 3-mercapto-5
-Nonyl-1,2,4-triazole, 3-mercapto-4-acetamido-5-heptyl-1,2,4-triazole, 3-mercapto-4-amino-5-heptadecyl-1,2,4-triazole , 2-mercapto-5-
Phenyl-1,3,4-thiadiazole, 2-mercapto-5-phenyl-1,3,4-thiadiazole, 2-
Mercapto-5-n-heptyl-oxathiazole, 2
-Mercapto-5-nheptyl-oxadiazole, 2
-Mercapto-5-phenyl-1,3,4-oxadiazole, 2-heptadecyl-5-phenyl-1,3,4
-Oxadiazole, 5-mercapto-1-phenyl-
Tetrazole, 2-mercapto-5-nitropyridine,
1-methyl-quinoline-2 (1H) -thione, 3-mercapto-4-methyl-6-phenyl-pyridazine, 2-
Mercapto-5,6-diphenyl-pyrazine, 2-mercapto-4,6-diphenyl-1,3,5-triazine, 2-amino-4-mercapto-6-benzyl-1,
3,5-triazine, 1,5-dimercapto-3,7-
And diphenyl-S-triazolino [1,2-a] -S-triazoline. In the present invention, the lipophilic agent is present at any position in the plate making process. It is a variety of processing liquids, ie, a developing liquid, a washing liquid, or a finishing liquid, or a lithographic printing material. It is preferable that the lipophilic agent is present at a plurality of positions. For example, a developer and a washing solution, or a washing solution and a finishing solution, etc., are more preferably contained in the developing solution, the washing solution and the finishing solution. Further, after the finishing treatment, it is preferable to further treat with a treatment liquid containing the above oleophilic agent. This processing liquid is preferably a processing liquid used for etching the plate surface just before the start of printing to bring the plate into a wet order state, and is lipophilic to a processing liquid called a so-called starter liquid or a desensitizing liquid (etching liquid). An embodiment in which the plate is treated with an agent is preferred. When the lipophilic agent is contained in the treatment liquid, the amount of addition is suitably about 0.01 to 10 g / l. When used in a lithographic printing material, it is contained in a silver halide emulsion layer and / or a physical development nucleus layer. The content is 0.
About 01 to 1 g / m ² is appropriate. The above-mentioned compound having a mercapto group or a thione group is dissolved in an alkaline solution, but is not dissolved in a neutral to weakly acidic washing solution or finishing solution, so that an organic solvent, an amine compound (for example, amino alcohol), polyethylene glycol, etc. , A quaternary ammonium salt type cationic surfactant or the like. In the developer used in the present invention, in addition to the lipophilic agent, developing agents such as polyhydroxybenzenes, 3-pyrazolidinones, and alkaline substances such as potassium hydroxide, sodium hydroxide, and hydroxide Lithium, 3rd
Sodium phosphate or 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 thiosulfuric acid Additives such as salts, thiocyanates, cyclic imides, thiosalicylic acid, mesoionic compounds and the like can be included. The pH of the developer is usually 10 to 1
4, preferably 12-14. The washing liquid used in the present invention has a pH of 4 to 8, preferably 4.5, in addition to the enzyme and the lipophilic agent.
Buffers that buffer in the range of ~ 7, such as phosphate buffers,
It can contain a citrate buffer or a mixture thereof. Further, a preservative may be contained. Between the developing process and the washing process, a neutralization stabilizing process for stopping the progress of the development may be performed, and the neutralizing solution may contain the lipophilic agent. The washing solution is used for completely removing the silver halide emulsion layer on the aluminum support.
Usually, a method of spraying a washing liquid at 25 to 35 ° C. by a jet method or a method of peeling the emulsion layer with a scrub roller while spraying the washing liquid is adopted. The silver image portion and the non-image portion exposed by the water washing process are treated with a finishing liquid in order to increase their lipophilicity and hydrophilicity and to protect the plate surface.
In the present invention, in addition to the above enzyme and lipophilic agent, in order to protect the anodized layer in the non-image area and improve hydrophilicity, the finishing liquid contains arabic gum, dextrin, sodium alginate, propylene glycol ester of alginic acid, It is preferable to contain a protective colloid such as ethyl starch, carboxymethylcellulose, hydroxyethylcellulose, polyvinylpyrrolidone, polystyrenesulfonic acid, and polyvinyl alcohol. The planographic printing plate of the present invention 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 emulsion type may be either a negative type or a positive type. These silver halide emulsions can be chemically or spectrally sensitized as necessary. The silver halide emulsion layer preferably contains the lipophilic agent. 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, arabic gum, hydroxyethyl cellulose and the like can be contained. As the hydrophilic colloid to be used, it is desirable to use a hydrophilic colloid layer substantially free of a hardener in order to facilitate the peelability after development. The aluminum support used in the present invention is a roughened and anodized aluminum plate, preferably the one described in US Pat. No. 5,427,889. The physical development nucleus of the physical development nucleus layer used in the present invention may be a physical development nucleus used in a known silver complex salt diffusion transfer method, for example, a colloid of gold or silver, or a water-soluble salt of 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. EXAMPLES The present invention will be described below with reference to examples. EXAMPLE 1 Electrolytic surface roughening treatment and anodization of an aluminum support were carried out according to the method described in US Pat. No. 5,427,889.
0.35 μm pits of about 5,60 per 100 μm ²
And the average diameter of these pits is 0.08
An aluminum plate having a thickness of 0.30 mm and a thickness of 0.3 μm was obtained.
This aluminum plate was anodized after the surface roughening treatment, and had an average roughness (Ra) of 0.5 to 0.6 μm. The aluminum support was coated with a physical development nucleus solution consisting of a silver sol prepared by the Curey Lea method, and then dried. The amount of silver contained in the physical development nucleus layer was 3 mg / m ² . As a silver halide emulsion, alkali-treated gelatin was used as a protective colloid, and potassium hexachloroiridate (IV) having an average particle size of 0.2 μm was prepared by a control double jet method in an amount of 0.006 m per mol of silver.
A mol-doped silver chloroiodobromide emulsion (AgBr 20 mol%, AgI 0.4 mol%) was prepared. Further, this emulsion was subjected to sulfur gold sensitization, and the sensitizing dye represented by Chemical formula 1 was added in an amount of 3 per gram of silver.
mg was used for spectral sensitization. Embedded image A surfactant is added to the thus-prepared silver halide emulsion, coated on the aluminum support coated with the physical development nuclei so that the silver amount becomes 2 g / m ² , and dried to form a lithographic plate. Printing material A was obtained. A lithographic printing plate obtained by further adding 0.2 g / m ^{2 of} 3-mercapto-5-nonyl-1,2,4-triazole as an oleophilic agent to the silver halide emulsion layer of the lithographic printing material A. B was created. A 633 nm red LD was used for the lithographic printing material.
An image was output by an output machine using a laser as a light source, and then processed by a plate-making processor (SLT-N automatic developing machine manufactured by DuPont) to prepare a lithographic printing plate. The plate-making processor includes a developing step (immersion at 21 ° C. for 30 seconds), a washing step (peeling off the emulsion layer with a scrub roller while shower jetting a washing liquid at 33 ° C. with strong force for 10 seconds), and a finishing step ( 21 ° C., shower for 5 seconds) and a drying step. Plate making was performed by changing the combination of the following developing solution, washing solution and finishing solution. <Developer A> Sodium hydroxide 20 g Hydroquinone 20 g 1-Phenyl-3-pyrazolidinone 2 g Anhydrous sodium sulfite 80 g Monomethylethanolamine 6 g Anhydrous sodium thiosulfate 6 g Ethylene diamine tetraacetate sodium salt 5 g Polyethylene glycol (average molecular weight 400) 10 g To 1000 cc. pH is 1
It was adjusted to 3.0. <Developer B> To Developer A, 0.5 g of 2-mercapto-5-nheptyl-oxadiazole was added as a lipophilic agent. <Washing solution A> Tap water <Washing solution B> Proteolytic enzyme 2 g Potassium monophosphate 40 g Water is added to adjust the total amount to 1000 cc. pH is 6.
Adjusted to zero. Bioprolase AL-15 (bacterial proteinase, Nagase Sangyo Co., Ltd.)
Was used. <Washing solution C> 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. pH is 6.
Adjusted to zero. Proteolytic enzyme is bioprase A
L-15. <Finishing liquid A> Gum arabic 10 g Proteolytic enzyme 2 g 2-mercapto-5-n-heptyl-oxadiazole 1 g Triethanolamine 26 g Sodium monophosphate 10 g Water is added to adjust the total amount to 1000 cc. pH 6.0
Was adjusted to Proteolytic enzyme is Bioprase AL
−15. <Finishing liquid B> 2-Mercapto-5-nheptyl-oxadiazole and triethanolamine were removed from the finishing liquid A. <Finishing solution C> The proteolytic enzyme (bioprelase AL-15) was removed from the finishing solution A. <Finishing Solution D> The proteolytic enzyme (bioprase AL-15), 2-mercapto-5-nheptyl-oxadiazole and triethanolamine were removed from the finishing solution A. With respect to the lithographic printing plate prepared by the above-described method, printing conditions relatively poor in ink acceptability obtained empirically, that is, a printing press Heidelberg TOK (Heidelbe
Printing is performed using an offset printing machine manufactured by RG Co., Ltd.), ink (New Champion Boku H, manufactured by Dainippon Ink and Chemicals Co., Ltd.), and a commercially available humidifying solution for PS plates. Was evaluated. The ink acceptability was evaluated by the number of sheets after the start of printing until the change in image density did not occur. Table 1 shows the results. [Table 1] As is apparent from the above results, the present invention is superior in ink receptivity as compared with the comparison. Example 2 A test was conducted in the same manner as in Example 1 except that the enzyme in Example 1 was replaced with trypsin, and the same results as in Example 1 were obtained. Example 3 The lipophilic agent of Example 1 was replaced with 3-mercapto-5-nonyl-
A test was conducted in the same manner as in Example 1 except that 1,2,4-triazole was used, but the same results as in Example 1 were obtained. Example 4 A test was conducted in the same manner as in Example 1 except that the lipophilic agent in Example 1 was changed to 3-pentylbenzoxazoline-2-thione, and the same results as in Example 1 were obtained. Example 5 Test No. 1 of Example 1 4 and NO. Immediately before starting printing, the printing plate prepared in Step 8 was treated with a processing solution (starter solution) containing 1 g / liter of 2-mercapto-5-nheptyl-oxadiazole and 26 g / liter of triethanolamine. When printing was performed in the same manner as in Example 1, the ink receptivity was improved to 11 sheets and 6 sheets, respectively. By using the plate making method of the present invention for plate making of an aluminum lithographic printing plate utilizing a silver complex salt diffusion transfer method, ink receptivity at the start of printing can be stably improved.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-116151 (JP, A) JP-A-63-260491 (JP, A) JP-A-5-313373 (JP, A) JP-A-5-313373 303206 (JP, A) JP-A-60-35734 (JP, A) JP-A-55-138743 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03F 7/07 B41C 1 / 10 B41N 3/08 G03F 7/00 503 G03F 7/32 G03C 8/36

Claims (1)

(57) [Claims 1] A lithographic printing material having a physical development nucleus between an aluminum support and a silver halide emulsion layer is exposed to a lithographic printing material in the order of at least a developing solution, a washing solution and a finishing solution after exposure. In the method of making a lithographic printing plate using a metallic silver image portion as an ink-receptive agent, the process is performed in the presence of a compound that renders the metallic silver image portion lipophilic in at least one of the processes, and A method for making a lithographic printing plate, wherein the washing liquid contains a protease.