JPS6119028B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for making a lithographic printing plate, and in particular to a method for making a lithographic printing plate from a photosensitive lithographic printing plate having a non-silver photosensitive layer and a photosensitive silver halide emulsion layer. The present invention relates to a plate-making method characterized by using a developer. A photosensitive planographic plate in which a non-silver photosensitive layer such as a photosensitive layer made of an o-quinonediazide compound is provided on a support having a hydrophilic surface such as an aluminum plate, and a gelatin silver halide photosensitive emulsion layer is further provided thereon. Printing plates are known, for example as described in GB 1227603. The plate-making method for obtaining a lithographic printing plate from such a photosensitive lithographic printing plate involves first (1) imagewise exposing a photosensitive silver halide emulsion layer, and (2) developing it with a silver halide developer (hereinafter referred to as step 1). 1
(3) forming a fixed silver image; (4) using the silver image as a mask to expose the underlying non-silver sensitive layer to the active light; and (5) then developing the layer containing the silver image. Basically, the process consists of removing at least a portion of the silver halide emulsion layer (that is, the imagewise exposed and developed silver halide emulsion layer), and then (6) developing the non-silver sensitive layer. The first development in such a plate-making method must satisfy the following various requirements. 1 The silver image obtained by the first phenomenon has a maximum optical density of 1.6 or more and a [base density +
0.3] to shadow, and such silver images have a duration of approximately 60 seconds or less, more preferably 30 seconds or less.
Must be stably obtained with a development time of seconds or less. 2. Silver images as described above can be obtained regardless of variations in processing time (for example, variations over 10 to 16 seconds). 3. The silver image obtained by exposure to actinic light in the above-mentioned plate-making method should be free from spots, image distortion, and unevenness. 4. The silver halide developer used in the first development has little performance deterioration due to air oxidation and has good stability over time. 5. It should not inhibit the removal of the silver halide emulsion layer in the plate-making method. In particular, patent application No. 54-100596
When the silver halide emulsion layer is removed using a proteolytic enzyme as described in JP-A-56-25739, it is important not to interfere with the action of the enzyme. However, it has been extremely difficult to find a silver halide developer that satisfies the above requirements from among the conventionally known solutions. In view of these circumstances, the present inventors have conducted various studies on photosensitive lithographic printing plates and plate-making methods using the same, and have discovered a plate-making method that satisfies the above requirements. , the gist of which is that on a support with a hydrophilic surface, a non-silver photosensitive layer capable of forming a lipophilic image and an average particle size of
A photosensitive lithographic printing plate having a photosensitive silver halide emulsion layer consisting of silver halide grains of 0.7 microns or less is imagewise exposed, the emulsion layer is developed and fixed with a silver halide developer, and the non-silver photosensitive layer is A method for making a lithographic printing plate comprising the step of developing the non-silver photosensitive layer after removing at least a portion of the emulsion layer by exposing to actinic rays, wherein the silver halide developer contains (a) 0.45 to 1.2 Mol/sulfite, (b)0.09
from 0.45 mol/hydroquinone and (c) 0.005
This plate-making method is characterized in that it is an aqueous solution containing 0.03 mol/mole of a compound represented by the following general formula [] and having a pH of 9 to 13. (In the general formula [], A represents an aromatic group,
R ₁ , R ₂ and R ₃ each represent a hydrogen atom, an aliphatic group or an aromatic group, and Z represents a hydrogen atom, an aminoalkyl group or a hydroxyalkyl group,
Except when R ₁ , R ₂ , R ₃ and Z are all hydrogen atoms. ) The basic composition of the photosensitive lithographic printing plate used in the plate-making method of the present invention is a non-silver photosensitive layer capable of forming a lipophilic image and a photosensitive silver halide emulsion on a support having a hydrophilic surface. The silver halide grains in the emulsion layer have an average grain size of 0.7 microns or less. Various types of supports having hydrophilic surfaces are known, but a particularly preferred one is an aluminum plate, the surface of which is grained,
For example, surface treatment such as chemical conversion treatment using an aqueous solution of sodium silicate, potassium fluorozirconate, or phosphate, or anodization treatment is preferably performed. As a non-silver photosensitive layer provided on such a support and capable of forming an oleophilic image, a photosensitive lithographic printing plate (pre-sensitized plate) is used.
Sensitized Plate) and abbreviated as PS version. ) includes a suitable photosensitive layer. Here, the above-mentioned "oleophilicity" means the property of repelling dampening water used during printing and accepting oil-based ink. The specific composition of such a non-silver photosensitive layer is as follows:
diazo resin, o-quinonediazide compound, photosensitive azide compound, polymer main chain or side chain.

[Formula] group-containing polymer compounds, and photopolymerizable compositions comprising addition-polymerizable unsaturated compounds and photoinitiators, all of which are well-known in this field. These compositions are coated onto a support from a solution in a suitable solvent and have a dry weight of from about 0.1 g/m ² to about 5 g/m ²
It is set up so that On the other hand, the photosensitive silver halide emulsion provided on the non-silver photosensitive layer may be a negative type emulsion or a direct positive type emulsion.
It is an emulsion of silver iodide or mixed silver halide, and the average grain size must be 0.7 microns or less. If a silver halide emulsion having an average grain size larger than 0.7 microns, such as a silver iodobromide emulsion used in X-ray film, is used, requirements 1 and 2 above cannot be satisfied. Moreover, it becomes difficult to complete the fixing process in a short time, and only a silver image is obtained in which the non-silver photosensitive layer has a low covering power for active light. Therefore, the average grain size of silver halide is preferably 0.01 to 0.5 microns. Photosensitive silver halide emulsions can be subjected to chemical sensitization such as sulfur sensitization, reduction sensitization, sensitization with noble metal salts, and spectral sensitization using sensitizing dyes, and can also be subjected to various commonly used additives. can be added. Particularly preferred silver halide emulsions in this invention are those containing at least about 20 mole percent silver chloride, at most about 80 mole percent silver bromide, and from 0 to at most 2 mole percent silver iodide. In addition, the silver halide emulsion layer contains a substantially water-insoluble lipophilic resin in the form of fine particles (preferably 0.01
It is preferable to disperse the colloid with a grain size of 1 to 10 μm, and the amount thereof is preferably 1 to 10 parts by weight per 10 parts by weight of hydrophilic colloid (eg, gelatin) in the silver halide emulsion. Examples of the above-mentioned lipophilic resins include silica resin, polyamide resin, phenolic resin, polyvinyl acetal resin, linear polyurethane resin, and polyester resin. The photosensitive silver halide emulsion layer is provided directly on the non-silver photosensitive layer or via an intermediate layer if necessary, and the coating amount is from about 1 g/m 2 to about 10 g/m ² in terms of dry weight.
g/m ² , preferably 2 to 6 g/m ² . Furthermore, when using a silver halide emulsion having a preferable halogen composition as described above, the amount of coated silver can be set from 1.0 g/m ² to 2.5 g/m ² , which is similar to that of X-ray film. 1/3 to 1/10 of coated silver amount
corresponds to A protective layer may be provided on the photosensitive silver halide emulsion layer. This protective layer may be one used in general silver halide photosensitive materials, or may be one as described in JP-A-52-154626. The method and process for making a lithographic printing plate using the PS plate as described above are as follows. Image exposure first,
A latent image is formed on the silver halide in the gelatin silver halide photosensitive emulsion layer. The silver halide is then developed (first development), treated with a fixing solution and then exposed to active light on the non-silver photosensitive layer, and then at least a portion, preferably all, of the gelatin silver halide photoemulsion layer is processed. After that, a second development process is carried out to remove the exposed or unexposed part of the non-silver photosensitive layer to expose the hydrophilic surface of the support and obtain a lithographic printing plate. It will be done. In this case, the processing solution used for the second development must be such that it selectively dissolves either the exposed or unexposed areas of the non-silver photosensitive layer, but depending on the type of non-silver photosensitive layer mentioned above, The appropriate treatment solution is
Various types are known. For example, when the non-silver photosensitive layer is a layer made of an o-quinonediazide compound, a sodium silicate aqueous solution or a
A developer such as that described in No. 4141733 is used. In the present invention, the first development in the above-mentioned plate-making step is performed using (a) 0.45 to 1.2 mol/sulfite, (b)
0.09 to 0.45 mol/hydroquinone and (c)
The process is characterized in that it is carried out using a silver halide developer consisting of an aqueous solution containing 0.005 to 0.03 mole of a compound represented by the following general formula [] and having a pH of 9 to 13. (In the general formula [], A represents an aromatic group,
R ₁ , R ₂ and R ₃ each represent a hydrogen atom, an aliphatic group or an aromatic group, and Z represents a hydrogen atom, an aminoalkyl group or a hydroxyalkyl group,
Except when R ₁ , R ₂ , R ₃ and Z are all hydrogen atoms. ) The developing agents of the developer used in the present invention are hydroquinone and a 1-aryl-3-pyrazolidone derivative represented by the general formula []. By using hydroquinone and a 1-aryl-3-pyrazolidone derivative in a relatively high concentration, ie, 0.09 to 0.45 mole/percentage, a developer that satisfies requirements 1 and 2 above can be obtained. By combining it with a higher concentration of sulfite than the amount normally used, i.e. 0.45 to 1.2 mol/
A developing solution that satisfies requirements other than the above-mentioned requirements 1 and 2 can be obtained. Sulfites are alkali metal or ammonium salts of sulfite. sulfites
By using 0.45 mol/or more, it improves the stability and solubility of the developing agent, increases the development activity of silver halide, widens the range of optimal processing time, increases processing capacity, and is used for subsequent processing. Fatigue of the fixer is reduced, and the above requirement 3 is also achieved.
Further, it is possible to suppress the hardening of the silver halide emulsion layer that occurs during development, fixing, and exposure to light, thereby providing advantageous washout properties. By the way, in the example of British Patent No. 1227603, there is a statement that a trace of phenidone, that is, 1-phenyl-3-pyrazolidone (unsubstituted product) is added to the developer. If this 1-phenyl-3-pyrazolidone is used in place of the 1-aryl-3-pyrazolidone derivative used in the present invention, the above requirement 2
Not only are conditions 4 and 4 not fully achieved, but development activity is lost and fogging occurs after 2 to 3 days of continuous processing. 1- represented by the general formula [] of the present invention
Surprisingly, when a certain amount of allyl-3-pyrazolidone derivative is used, the fatigue of hydroquinone is reduced.
-Fatigue of the aryl-3-pyrazolidone derivatives is also significantly reduced. In the developing solution having the composition of the present invention,
Development of silver halide proceeds by consuming almost the theoretical value of hydroquinone and the theoretical value of sulfohydroquinone produced during the development process, and progresses without consuming too much of the 1-aryl-3-pyrazolidone derivative. I can think of it. Next, the compound represented by the above general formula [] will be explained. A in the general formula [] represents an aromatic group, and specifically includes an unsubstituted aryl group and a substituted aryl group. An example of an unsubstituted aryl group is phenyl, and examples of substituted aryl groups include tolyl, p-methoxyphenyl, p-
Ethoxyphenyl, p-hydroxymethylphenyl, hydroxyphenyl, o-chlorophenyl,
Examples include various groups such as carboxyphenyl. R ₁ , R ₂ and R ₃ in the general formula [] each represent an aliphatic group or an aromatic group, and aliphatic groups include unsubstituted alkyl groups and substituted alkyl groups, and aromatic groups include unsubstituted alkyl groups. Includes aryl groups and substituted aryl groups. The unsubstituted alkyl group preferably has 1 to 4 carbon atoms, such as methyl, ethyl, propyl, isopropyl, etc.
Substituted alkyl groups include hydroxymethyl, methoxymethyl, aminoethyl, chloromethyl, carboxymethyl, vinylmethyl, benzyl, o-
Examples include various groups such as chlorobenzyl. In addition, unsubstituted aryl groups include phenyl groups, and substituted aryl groups include p-hydroxyphenyl,
o-methoxyphenyl, m-aminophenyl, o
Examples include groups such as -carboxyphenyl.
Furthermore, Z in the general formula [] represents a hydrogen atom, for example an aminoalkyl group such as an aminoethyl group, or a hydroxyalkyl group such as hydroxyethyl. Among the compounds represented by the above general formula [], particularly preferred in the present invention are compounds in which R ₃ and Z are hydrogen atoms. Preferred specific examples of the compound represented by the above general formula [] include the following. -1 4-Methyl-1-phenyl-3-pyrazolidone-2 4,4-dimethyl-1-phenyl-3-
Pyrazolidone-3 4-hydroxymethyl-1-phenyl-
3-pyrazolidone-4 4,4-di(hydroxymethyl)-1-
Phenyl-3-pyrazolidone-5 4-methyl-1-p-tolyl-3-pyrazolidone-6 4-dimethylaminomethyl-1-p-chlorophenyl-3-pyrazolidone The compound represented by the general formula [ ] is disclosed in British Patent No.
1093281, French Patent No. 1454109, French Patent No. 1454177
No. 1573593, U.S. Patent No. 3241967, U.S. Patent No.
3453109 and 3740221, and other compounds are also synthesized according to the synthesis methods described in these specifications.
can be obtained easily. The compounds represented by the general formula [] can be used alone or in combination of two or more, and the amount used must be in the range of 0.005 to 0.03 mol/, preferably 0.006 to 0.015 mol/ . On the other hand, the sulfite contained in the silver halide developer is preferably an alkali metal salt such as sodium sulfite or potassium sulfite, or ammonium sulfite, and the amount used should be in the range of 0.45 to 1.2 mol/, preferably 0.5 to 1.2 mol/. Also, the preferred amount of hydroquinone used is 0.18
The range is from 0.40 mol/. Since the silver halide developer used in the present invention has a pH in the range of 9 to 13, an alkaline agent is added. Examples of alkaline agents used include alkali metal hydroxides, carbonates, phosphates, borates, and aqueous ammonia, which are combined with suitable buffers, such as inorganic acids or organic acids corresponding to the above-mentioned salts.
Used with silicates, organic amines (eg pyridine, triethanolamine, diethanolamine), etc. The silver halide developer used in the present invention includes:
By further adding glycols, the above-mentioned requirements 3 and 5 can be more easily achieved. Preferred glycols have a boiling point of 180°C or higher, a solubility in water of 10% by weight or higher, and are good solvents for developing agents, especially 1-aryl-3-pyrazolidone derivatives, and have the following general formula: It is selected from the compounds indicated by [ ]. (In the general formula [], R ₄ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ₅ represents a hydrogen atom, a methyl group, or an ethyl group, and n represents 1 to 5
indicates an integer. ) Preferred specific examples of glycols include ethylene glycol monomethyl ether, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, and the like. For glycols, silver halide developer 1
It is preferable to use between 10 and 80 g per serving.
This not only makes it easier to dissolve the developing agent as an aqueous solution, but also suppresses rapid drying of the emulsion film surface after development, fixing, and processing, prevents precipitation of salts, and prevents spots caused by exposure to light and distortion of silver images. This has the effect of preventing the occurrence of unevenness and making it easier to wash out the silver halide emulsion layer. The silver halide developer used in the present invention includes:
Various commonly known additives, such as potassium bromide, potassium iodide, US Pat. No. 2,496,940,
Antifoggants such as nitrobenzimidazole and 1-phenyl-5-mercaptotetrazole described in the same No. 2656271, such as alkali metal salts of alkylene polyamine polycarboxylic acids (e.g. disodium EDTA salt), alkali metal salts of polyphosphates. Water softeners such as alkali metal phosphonates may also be added. According to the plate making method of the present invention, the first development can be completed in a short time. Therefore, when designing an automatic plate printing machine, there is an advantage that the volume for the first development can be made small. Furthermore, since the silver halide developer used in the present invention is not easily oxidized by air, a method can be adopted in which the developer is sprayed onto the photosensitive silver halide emulsion layer of the PS plate. This is extremely advantageous in terms of the design of an automatic plate making machine. The content of the present invention will be specifically explained below using Examples. Note that % indicates weight % unless otherwise specified. Example 1 A 2S aluminum plate mechanically grained by the method disclosed in JP-A-48-33911 was immersed in a 2% sodium hydroxide aqueous solution kept at 40°C for 1 minute to corrode a part of the surface. . After washing with water, it was immersed in a sulfuric acid-chromic acid solution for about 1 minute to expose the pure aluminum surface. It was immersed in 20% sulfuric acid kept at 30°C, anodized for 2 minutes at a DC voltage of 1.5V and a current density of 3A/dm ² , then washed with water and dried. Next, a photosensitive solution having the following composition was continuously coated using a roll coater so that the dry weight was about 2 g/m ² to provide a non-silver photosensitive layer.

[Table] Next, use a photosensitive solution with the following composition, with a dry weight of 4.5 g/m ²
It was coated continuously so that the final temperature was 90°C and dried with hot air. Let this sample be No.1. Phenol formaldehyde resin MP120HH
(manufactured by Gunei Chemical Industry Co., Ltd.) was dissolved in a mixture of 330 g of ethyl acetate and 120 g of methyl ethyl ketone, 10% gelatin, and 600 ml of an aqueous solution, 60 ml of a 10% solution of sodium nonylbenzenesulfonate and 10% funnel oil. Emulsion dispersed in a solution mixed with 150 ml of methanol solution …………1300 g Silver chlorobromide gelatin emulsion (Cl ^- 70 mol%, Br ^- 30
Mol% of silver chlorobromide, average particle size…………0.28μ,
(Contains 55 g of gelatin and 0.85 mol of silver halide per 1 kg of emulsion) 2000 g 1,3-diethyl-5-[2-{3-(3-sulfopropyl)benzoxazol-2-ylidene}ethylidene]thiohydantoin sodium 0.1% methanol solution of salt …………100ml 4-hydroxy-6-methyl-1・3・3a・
0.5% alkaline aqueous solution of 7-tetrazaindene 200ml 2% aqueous solution of 2,4-dichloro-6-hydroxy-s-triazine 70ml On the other hand, for comparison, silver chlorobromide gelatin emulsion 2000
g instead of the same amount of X-ray film emulsion, i.e. silver iodobromide emulsion (Br ^- 98 mol%, I ^- 2 mol% silver iodobromide, average grain size 1.0μ, 55g gelatin per 1kg emulsion) Sample No. A was obtained in exactly the same manner as Sample No. 1, except that 0.85 mol of silver halide) was used. After each sample was left at room temperature for 4 days, the resulting transparent micro-negative film was reduced to about 1/6 and the text and line drawings were photographed. Image exposure was performed for 5 seconds under magnification. Sample A was exposed imagewise through a gray filter with an optical density of 1.34. Next, the following processing was performed using an automatic plate making machine. A stock solution formulation of a silver halide developer having the composition shown below was diluted 1:1 with water or the stock solution was run at 32°C for 20 seconds, and the following fixer () was run at 20°C for 10 seconds. Next, pass through an ultraviolet exposure section consisting of three reflector-type mercury lamps for 15 seconds, pass through the following washing solution () at 40-45℃ at the washing section, rub with a brush, pass through a squeeze roller, and then apply a developer solution with the composition below. () for 30 seconds at 30°C and coated with gum arabic solution to obtain a printing plate.

【table】

[Table] Fixing solution () Water …………700ml Ammonium thiosulfate …………224g Sodium sulfite …………20g Add water to make 1000ml Washing solution () Bioplase PN-4 (Nagase Seikagaku Kogyo) Enzyme Co., Ltd.) …10g Water …1 Developer solution () JIS No. 1 Sodium silicate …100g Sodium metasilicate …50g Pure water …1800ml The above plate-making process The performance of each PS plate of Samples No. 1 and A as a printing plate was evaluated in the case where it was processed at 5 m ² / over 4 days and when it was processed at 10 m ² / over 8 days. Printing was carried out using a Heidel KOR printing machine, and the results shown in Table 1 were obtained.

[Table] From the results shown in Table 1, it can be seen that the lithographic printing plates obtained by the plate making method of the present invention are excellent. i.e. sulfite, hydroquinone and 1-
Good results have been obtained only when the amount of each of the phenyl-3-pyrazolidone derivatives in the developer lies within a certain range. Also, 1-phenyl-3- which is not included in the compound represented by the above general formula []
When using pyrazolidone, good results cannot be obtained even if the amount used is within the specified range as mentioned above (see the results when using silver halide developer stock solution No. B) . Furthermore, even with the silver halide developer used in the present invention, good results can be obtained when the average grain size of the silver halide in the photosensitive silver halide emulsion of the PS plate is larger than 0.7 microns. (See the case using sample No. A).

Claims (1)

[Scope of Claims] 1. On a support having a hydrophilic surface, a non-silver photosensitive layer capable of forming a lipophilic image and an average particle size of
A photosensitive lithographic printing plate having a photosensitive silver halide emulsion layer consisting of silver halide grains of 0.7 microns or less is imagewise exposed, the emulsion layer is developed and fixed with a silver halide developer, and the non-silver photosensitive layer is A method for making a lithographic printing plate comprising the step of developing the non-silver photosensitive layer after removing at least a portion of the emulsion layer by exposing to actinic rays, wherein the silver halide developer contains (a) 0.45 to 1.2 Mol/sulfite, (b)0.09
from 0.45 mol/hydroquinone and (c)
A plate-making method characterized in that the aqueous solution contains 0.005 to 0.03 mole of a compound represented by the following general formula [] and has a pH of 9 to 13. (In the general formula [], A represents an aromatic group,
R ₁ , R ₂ and R ₃ each represent a hydrogen atom, an aliphatic group or an aromatic group, and Z represents a hydrogen atom, an aminoalkyl group or a hydroxyalkyl group,
Except when R ₁ , R ₂ , R ₃ and Z are all hydrogen atoms. )