JPH0545884A - Developer for planographic printing plate - Google Patents

Abstract

PURPOSE:To obtain a silver picture image having high ink-receiving property and large plate wear resistance in the developing process of direct planographic printing using a silver complex salt diffusion-transfer process by adding a specified diffusion-transfer promotor into the developer liquid. CONSTITUTION:At least one compd. expressed by formula I is incorporated into the developer for a planographic printing plate using a silver complex salt diffusion-transfer process. In formula I, R is hydrogen atom, alkyl group (e.g. methyl group), or aryl group (e.g. phenyl group), R1 is alkylene group (e.g. ethylene, propylene, tetraethylene), and n is 1-4. This compd. can be incorporated in a single form or with other compd. into treating liquids for photographic printing such as a stopping liquid or fixing liquid or into various treating liquids used in printing processes such as desensitizing liquid and dampening liquid. Especially, it is effective to incorporate the compd. above described into a developer.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a developer used for a lithographic printing plate by a silver complex salt diffusion transfer method.

[0002]

2. Description of the Related Art An offset printing plate using a silver image obtained by a silver complex salt diffusion transfer method (DTR) has already been described in JP-B-46-43132 and JP-A-48-30562, and further positive type printing. For the original plate, JP-A-49-55402, and for the negative type printing original plate, JP-A-52-106902 and 52-112.
No. 402 and the like are described in detail.

The construction of these direct printing plates comprises a subbing layer for preventing halation, a silver halide emulsion layer, and a physical development nucleus layer on a support. When the photosensitive material is imagewise exposed and then developed, the silver halide on which a latent image is formed becomes blackened silver in the emulsion layer. On the other hand, silver halide on which no latent image is formed is dissolved by the silver halide complexing agent in the development processing solution and diffuses to the surface of the photosensitive material.
The diffused silver complex salt is deposited as a silver image on the physical development nuclei of the surface layer by the reducing action of the developing agent. In order to enhance the ink receptivity of the silver image thus obtained, an oil-sensitizing treatment is performed if necessary, and the ink image is transferred to a printed matter by an offset printing machine. Thus, the direct photographic printing material has advantages such as excellent operability and cost, but on the other hand, due to the nature of forming a printing silver image by photographic development processing, excess silver ions tend to remain, Was one of the causes of deterioration of storage stability and printing durability. Various methods are utilized to remedy these drawbacks. One is the use of oxidizing agents. JP-A-55-9875
No. 3, describes the combined use of a sulfur-containing organic compound and an oxidizing agent.
No. 223740 describes a method of improving printing durability using iodine ions and an oxidizing agent. Further, the removal of excessive silver ions by using the chelate resin was also effective in increasing the printing durability. However, these methods often tend to lower the ink acceptability of silver images, and there has been no satisfactory method for increasing the printing durability without lowering the ink acceptability.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to obtain a silver image having good printing durability and high ink acceptability in the development process of a direct lithographic printing plate using a silver complex salt diffusion transfer method. To provide the liquid.

[0005]

The object of the present invention has been achieved by adding a diffusion transfer accelerator represented by the chemical formula 2 during the development processing.

[0006]

[Chemical 2]

In the formula, R represents a hydrogen atom, an alkyl group (eg, methyl group) or an aryl group (eg, phenyl group), and R ₁ represents an alkylene group (eg, ethylene, propylene, tetraethylene). , N represents 1 to 4.

Representative specific examples of the compound of Chemical formula 2 used in the present invention are shown below.

[0009]

[Chemical 3]

[0010]

[Chemical 4]

[0011]

[Chemical 5]

[0012]

[Chemical 6]

[0013]

[Chemical 7]

[0014]

[Chemical 8]

[0015]

[Chemical 9]

[0016]

[Chemical 10]

These compounds are commercially available, for example, from the Journal of Chemical Society (JCS) 72 ,
1879 (1950), Journal of Organic Chemistry (JOC) 24 , 470 (19).
53), Britain Chemical Society (Bul
l. Chem. Soc. ) 40 , 2854 (196)
7), Pharmaceutical Journal 85 , 1537 (1968), Japanese Patent Publication Sho 3
9 , 26203, 60 , 11341 and the like. The details of the synthesis method will be described below using synthesis examples.

Synthesis Example 1 (Synthesis of Exemplified Compound 3) 2-Amino-2 ′ -Hydroxy
Cidiethyl sulfide 4.81 g, triethylamine
Internal temperature of a mixture of 4.86 g and 50 ml of ethyl alcohol
3.35 g of carbon disulfide are added with stirring at 0 ° C. Room
After 2 hours of warm stirring, the mixture was further heated at 50 ° C. for 30 minutes. afterwards
The internal temperature was cooled to 0 ° C, and 3.83 g of chloroacetone was added.
It was Stir at room temperature for 1 hour. After heating at 40 ° C for 2 hours, the reaction mixture
Is concentrated under reduced pressure, and 30 ml of acetic acid is added to the residue. Heating 3
After hours, the reaction mixture was diluted with water and extracted with ethyl acetate,
The ethyl acetate layer was washed with water and dried over anhydrous sodium sulfate,
The ethyl acetate was distilled off. Column chromatography of the residue
-(Chloroform / methanol = 10/1)
6.51 g of a pale yellow oil was obtained. CMR (CDCL₃)
δ 188.5, 139.5, 106.4, 61.0, 4
7.1, 35.1, 28.1, 15.5 PMR (CD
CL₃) Δ8.28, 4.35, 3.80, 3.47,
2.95, 2.82, 2.35

The amount of the compound of the present invention added to the developing solution is preferably 0.01 to 10.0% by weight, more preferably 0.01 to 4.0% by weight.

The developing solution of the present invention contains an alkaline substance,
For example, sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium triphosphate, etc. and sulfites as preservatives (potassium sulfite, sodium sulfite, etc.) are essential, but other compounds such as sulfates (sulfuric acid Sodium, ammonium sulfate, etc.), phosphoric acid, nitric acid, nitrous acid,
Tannic acid and salts thereof, wetting agents, for example, polyol compounds having two or more hydroxy groups (polyethylene glycol, propylene glycol, pentaerytriol, glycerol, hexylene glycol, etc.), organic acids (citric acid, succinic acid, tartaric acid, Adipic acid, ascorbic acid, propionic acid, etc.), inorganic fine particles (colloidal silica, alumina, etc.), polyacrylic acid, ammonium dichromate, chrome ban, silver halide solvent (thiosulfate, thiocyanate, cyclic imide) , Thiosalicylic acid, amines, etc., thickeners (gum arabic, hydroxyethyl cellulose (HEC), carboxemethyl cellulose (CMC), sodium alginate, vinyl pyrrolidone (PVP), vinyl imidazole, methyl vinyl ether-maleic anhydride Acid copolymers, carboxymethyl starch, ammonium alginate, alginate oxydide cellulose, methyl cellulose, etc.), antifoggants (potassium bromide, 1-phenyl-5-mercaptodetrazole, described in JP-A-47-26201). Compound), developing agent (hydroquinone, 1-phenyl-3-
Pyrazolidone, metol, phenidone, catechol, pyrogallol, glycine, chlorohydroquinone, etc.), a development modifier (polyoxyalkylene compound, onium compound), etc. may be contained. Further, a surfactant [propylene glycol alginate, aminopolycarboxylic acid salt (sodium ethylenediaminetetraacetate, etc.)] 1
It is also possible to contain one kind or two or more kinds. In addition to this, a water-miscible organic solvent for the solvent of the compound of the present invention (methanol, ethanol, propanol, isopropyl alcohol, n-butyl alcohol, dimethylformaldehyde, dioxane, etc.) can be included.

In carrying out the complex salt diffusion transfer method, for example, British Patent Nos. 1,000,115 and 1,012,47.
No. 6, No. 1,017,273, No. 1,042,477
It is practiced to incorporate a developing agent into the silver halide emulsion layer and / or the image-receiving layer or another water-permeable layer adjacent thereto as described in the specification of U.S. Pat. Therefore, in such a light-sensitive material, the processing solution used for development may be a so-called "alkaline activating solution" containing no developing agent.

The silver halide emulsion of the lithographic printing plate used in the practice of the present invention may be silver chloride, silver bromide, silver chlorobromide, silver chloroiodide or silver chlorobromoiodide, preferably silver chloride. Fifty
It is a silver halide of mol% or more. These silver halide emulsions include spectral sensitizers (light sources, spectral sensitizing dyes depending on the application, such as camera type, laser light type, panchromatic type for color separation), gelatin hardening agents, coating aids, antifoggants. , A plasticizer, a developing agent, a matting agent and the like.

The binder used in the silver halide emulsion of the lithographic printing plate of the present invention is usually gelatin. Gelatin is a part of starch, albumin, sodium alginate, hydroxyethyl cellulose (HEC),
Hydrophilic polymer bonds such as gum arabic, polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), carboxymethyl cellulose (CMC), polyacrylamide, styrene-maleic anhydride copolymer, polyvinyl methyl ether-maleic anhydride copolymer, etc. It is also possible to substitute with one or more agents. Further, an aqueous dispersion of vinyl copolymer (latex) can also be used.

On the lower side (support surface) of the silver halide emulsion layer, an adhesion improving subbing layer and / or a subbing layer for the purpose of preventing halation may be contained, and a developing agent and a matting agent are contained in this layer. Can be included.

The support on which the silver halide emulsion is coated is
Paper, various films, plastics, paper coated with resin-like substances, metal plates, etc. can be used.

The physical development nuclei used in the physical development nuclei layer are
Chemicals of this type are well known and include antimony, cadmium, cobalt, palladium, nickel, silver, lead, zinc,
Metals such as and their sulfides can be used. The physical development nucleus layer may also contain a developing agent, or may contain a hydrophilic binder.

The compound of the chemical formula 2 of the present invention is used in a photolithography processing solution such as a stop solution and a fixing solution used in the present invention, or in various processing solutions such as a desensitizing solution and a dampening solution used in a printing process step. They can be contained alone or in combination, but it is particularly effective to contain them in the developing solution.

[0028]

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

Example 1 A matting layer containing silica particles having an average particle size of 5 μ was provided on one surface of a polyester film support which had been subjected to an undercoating treatment, and an amount of carbon having an optical reflectance of 3% at 633 nm was provided on the opposite surface. 20 including photographic gelatin, including black
5% by weight of an anti-halation undercoat layer containing silica powder having an average particle size of 7 μm (adjusted to pH 4.0) and silica powder having an average particle size of 7 μm after being chemically sensitized with respect to photographic gelatin. And a spectrally sensitized high-sensitivity silver chloride emulsion (adjusted to pH 4.0). The gelatin of the undercoat layer is 3.5 g / m ² , and the gelatin of the emulsion layer is 0.8 g / m ² .
m ² and 1.0 g / m ² of silver halide converted to silver nitrate were applied. The subbing layer and the emulsion layer contain formalin as a hardening agent in an amount of 5.0 mg / g based on gelatin. After drying and heating at 40 ° C. for 14 days, the emulsion is coated with the core solution described in Plate No. 31 of Example 2 of JP-A-54-103104 and dried to produce a lithographic printing plate. The silver halide emulsion was prepared by adding 4 × 10 ⁻⁶ mol of rhodium chloride per mol of silver halide during physical ripening, and had an average grain size of 0.40 μm. The original plate of the lithographic printing plate thus obtained was image-exposed with a plate-making camera having an image reversal mechanism, and developed with the following developer A (use solution) at 30 ° C. for 30 seconds, followed by the following neutralizing solution. Processed in.

Developer A Sodium hydroxide 24 g Potassium hydroxide 8 g Anhydrous sodium sulfite 50 g 2-Methyl-2-amino-1-propanol 30 g Uracil 0.2 g Water is added to make 1 liter.

Neutralizing solution Ethylene glycol 5 g Colloidal silica (20% aqueous solution) 1 g Citric acid 10 g Sodium citrate 35 g Water is added to make 1 liter.

On the other hand, for the purpose of comparison with the developer A, a developer B (B1 to B8) was prepared by adding the compound of the chemical formula 3 of the present invention into the developer, and the developer A was completely used. Plate-making processing was carried out similarly. Then, the printing plate was set in an offset printing machine, the plate surface was sufficiently wetted with an etchant having the following composition, and printing was performed using a dampening solution having the following composition.

Etching solution Water 600 ml Isopropanol 400 ml Ethylene glycol 50 g 3-Mercapto-4-acetamido-5-n-butyl-1,2,4-triazol 1 g

Humidifying liquid Water 8 l Succinic acid 6 g Sodium sulfate 25 g Ethylene glycol 100 g Colloidal silica (20% aqueous solution) 28 g

The printing machine is ABCD350CD
(Trademark of offset printing machine manufactured by AB Dick) was used. The printing durability of printing was judged by the following method. 1,
Printing was continued from 000 sheets to 50,000,000 sheets, and the following five levels were evaluated according to the number of printed sheets when the ink spreads in the silver image area. A 50,000 or more B 50,000 or less C 25,000 or less D 5,000 or less E 2,000 or less

[0036]

[Table 1]

The printing plate obtained with the developer A has a thickness of 5,000.
In contrast to the partial missing of the transferred silver image by the number of sheets,
The printing plate obtained with the developer B (B1 to B8) of the present invention is
Even with 10,000 sheets, the transfer silver image was not lost.

Example 2 A plate-making process was carried out in the same manner as in the developer A except that 0.5 g / l of each of Chemical formulas 4 to 10 was added instead of Chemical formula 3 used in the developer B of Example 1. Processed. The printing results are shown in the table. The printing durability was better than that of Developer A in all cases.

[0039]

[Table 2]

[0040]

EFFECTS OF THE INVENTION The planographic printing plate prepared by the developing solution of the present invention is improved in the lack of transferred silver image, the printing durability is remarkably improved, and the ink receiving ability is not deteriorated.

Claims (1)

[Claims] 1. A developer for a lithographic printing plate using a silver complex salt diffusion transfer method, which contains at least one compound represented by the following formula: [Chemical 1] In the formula, R represents a hydrogen atom, an alkyl group or an aryl group, R ₁ represents an alkylene group, and n represents 1 to 4.