JPH07281443A - Developer for planographic printing plate - Google Patents

Abstract

PURPOSE:To provide a developer responsible for rapid processing in a plate making method of a planographic printing plate using a silver complex salt diffusion transfer method which is extremely effective for rapid development so that lots of planographic printing plates can be rapidly produced with a small amt. of developer without causing decrease in plate wear or contamination with ink which are caused when a developer of conventional system is used. CONSTITUTION:This developer contains a cation surfactant (formula I) or anion surfactant (formula II) having polyoxyethylene chains. In formulae, R1 is an alkyl group having 10 to 20 carbon number, R2 is an alkyl or aryl group having 5-20 carbon number, x, y and z satisfy 5<x+y+z<20, 1<x<15, 1<y<15, 1<z<15, and n satisfies 7<n<14, X is an anion, and M is a cation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithographic printing plate developing solution utilizing a silver complex salt diffusion transfer method, and in particular, a lithographic printing plate is coated with a developing solution in an amount necessary for development. It is suitable for the method (hereinafter referred to as rapid processing).

[0002]

2. Description of the Related Art A lithographic printing plate supplies both water and ink to a plate surface to selectively receive a coloring ink in an image area and water in a non-image area, for example, an ink on the image. Printing is performed by transferring to a printing medium such as paper. Therefore, in order to obtain a good printed matter, the difference in the lipophilicity and hydrophilicity of the surface between the image area and the background non-image area is sufficiently large, and when water and ink are applied, the image area contains a sufficient amount of ink. It is necessary that the non-image area accepts no ink.

A lithographic printing plate using a silver complex salt diffusion transfer method (DTR method), particularly a lithographic printing plate having a physical development nucleus layer on a silver halide emulsion layer is described in, for example, US Pat.
No. 114, No. 4,134,769, No. 4,16
0,670, 4,336,321, 4,5
01, 811, No. 4,510, 228, No. 4,
No. 621,041 and the like.

The exposed silver halide crystals undergo chemical development in the emulsion layer by development processing to become blackened silver, forming hydrophilic non-image areas. On the other hand, the unexposed silver halide crystals are solubilized by the silver complex salt forming agent in the developer, diffused to the physical development nucleus layer on the surface, and the reducing action of the developing agent on the physical development nuclei causes the ink-accepting image silver. Is deposited as.

Therefore, a lithographic printing plate using the DTR method undergoes chemical development and dissolution physical development during development processing. In order for the lithographic printing plate to obtain sufficient printing durability as a printing plate, the balance between the chemical / dissolution physical development and the development is important.

If the chemical development is too fast, sufficient printing durability cannot be obtained, and if the dissolution physical development is too fast, it causes ink stains.

In the development processing method which has been put into practice for such a lithographic printing plate, a development processing tank and a stabilizing processing tank (neutralization processing tank) are used.
An automatic plate-making camera with a built-in is used.

In the plate-making processing method as described above, a developer who has a large amount of plate-making processing discharges a large amount of the developing solution, which becomes waste liquid. Economically, it was a heavy burden on employers.

Needless to say, it takes time to pass through the developing solution tank and, if necessary, the neutralizing solution tank, and fatigue of the developing solution due to the processing of a large number of sheets, for example, a decrease in pH, the generation of sludge, etc. Had.

JP-A-48-76603 and 57-11.
No. 5549 describes a rapid processing method in which an amount of developing solution necessary for developing a lithographic printing plate is applied and supplied to the plate surface to carry out a plate-making process. In the rapid processing, the developing solution can be developed by always supplying the necessary minimum amount of the developing solution, the developing time can be shortened, and the fatigue of the developing solution becomes irrelevant.

However, it has been experimentally found that various problems occur when a conventional developing bath type developing solution is applied to the rapid processing system. First, the developing temperature depends on the ambient temperature, and a wide suitable temperature range is required. Second, there is a change in the development speed balance between chemical development and dissolution physical development. That is, dissolution physical development occurs up to the area where chemical development should originally occur. Or vice versa. Thirdly, in the rapid processing method, it was confirmed that the additives, which were conventionally used, do not exert their effects. That is, the additive does not penetrate into the inside of the light-sensitive material.

Conventionally, various anionic activators have been used as coating aids for various coating liquids for photographic light-sensitive materials.
Specific examples thereof are US Pat. Nos. 2,240,476 and 3,
026,202, 3,068,101, 3,2
No. 20,847, No. 3,415,649, West German Patent No. 1,942,665, and the like.

However, what is described in the conventional patent is to improve the coatability of the emulsion. In the coating and developing method, the coatability of the developing solution becomes a problem, and thus it is added to the processing solution in the coating and developing method to improve the coatability and not only to affect the printability but also to strengthen the printing durability. There have been no reports of surfactants so far.

An aqueous solution containing a quaternary ammonium surfactant has already been described in JP-A-3-501831, but the present invention is directed to a developer composition in a coating and developing system. It is unpredictable that by adding such a surfactant to the developing solution, sufficient developing activity can be obtained to secure the ink acceptability and further enhance the printing durability even in a processing method having a low developing activity. Met.

[0015]

SUMMARY OF THE INVENTION The object of the present invention is to provide DT
A developing solution for a lithographic printing plate using the R method is suitable for a rapid processing method, has a good coating property of the developing solution, has a wide range of developing temperature, does not cause ink stains, and further enhances printing durability. To provide such a developer.

[0016]

The object of the present invention is to provide a developer used in a method of coating and developing by supplying a necessary developing solution in a plate making method of a lithographic printing plate utilizing a silver complex salt diffusion transfer method. Achieved with a developer characterized by containing at least one kind of cationic surfactant (Chemical formula 3) or anionic surfactant (Chemical formula 4) having a polyoxyethylene chain represented by the following general formula. Was done.

[0017]

[Chemical 3]

[0018]

[Chemical 4]

In the formula, R1 represents an alkyl group having 10 to 20 carbon atoms, and R2 represents an alkyl group or aryl group having 5 to 20 carbon atoms. x, y, z are 5 <x + y + z
<20, 1 <x <15, 1 <y <15, 1 <z <15, and n is 7 <n <14. Further, X is a monovalent anion such as a halide ion, and M is 1 such as K or Na.
It is a cation.

A more detailed description will be given below. The rapid processing method described in the present invention is a method in which a necessary developing solution is supplied to a light-sensitive material to apply and develop it, and is disclosed in JP-A-48-7660.
No. 3 is described. For example, there are a liquid coating method, a dripping method roller coating method, a dripping method knife coating method, a spray coating method, a brush coating method, etc., but not limited to these. For simplicity, a so-called doctor bar in which a bar is wound around a rod made of an appropriate material can be used. Specifically, the development is performed on the surface of the printing plate that is horizontal and coated with the silver halide emulsion layer. A method of dropping the solution and spreading the developing solution with a doctor bar or a method of passing the solution through an extremely small processing tank in a short time and adsorbing and coating the processing solution on the photosensitive surface can also be adopted.

In the sense of rapid processing, the coating amount of the developing solution on the lithographic printing plate is 10 to 1 per 1 square meter of the printing plate.
It is in the range of 50 ml, preferably in the range of 20 to 80 ml, and the developing time (the time from the application of the developing solution until the developing solution stops the developing effect) is 15 seconds or less, preferably the range of 2 to 10 seconds. The development temperature depends on the temperature control accuracy, but it is 20-4
It has a width of 5 ° C.

In the plate making method using the developing solution of the present invention, for example, a planographic printing plate is first coated with the developing solution, and then the developing solution on the plate surface is removed by a squeezing roller or the like. Next, if necessary, p
To reduce H, a neutralizing solution or washing with water is performed, and further, in an automatic plate making machine or the like, the plate making is completed through a drying step. Of course, a step of heating the lithographic printing plate or the developing solution can be included if necessary during the plate making step.

The following are some specific examples of effective polyethylene alkyl ether (secondary alkyl ether) or polyoxyethylene alkyl phenyl ether (nonyl phenyl ether), but the present invention is not limited thereto.

[0024]

[Chemical 5]

[0025]

[Chemical 6]

[0026]

[Chemical 7]

[0027]

[Chemical 8]

[0028]

[Chemical 9]

[0029]

[Chemical 10]

The amount of the above compound used in the present invention contained in the developing solution is 0.01 g / l to 2.00 g / l,
The range is preferably 0.50 g / l to 1.00 g / l.

In the developer used in the present invention, alkaline substances such as sodium hydroxide, potassium hydroxide, lithium hydroxide, and sodium triphosphate are used, and preservatives such as sulfite salts and silver complex-forming agents such as sodium hydroxide are used. Thiosulfates, alkanolamines, thiocyanates, cyclic imides, thiosalicylic acid, etc., viscous agents such as hydroxymethyl cellulose, carboxymethyl cellulose, antifoggants,
For example, potassium bromide, 1-phenyl-5-mercaptotetrazole, the compounds described in JP-A-47-26201 and the like, and developers such as hydroquinone and 1-phenyl-3-pyrazolidone can be contained.

In carrying out the DTR method, for example, British Patent Nos. 1,000,115, 1,012,476, and 1,017,
No. 273, No. 1,042,477, etc., a developer is incorporated into a silver halide emulsion layer and / or an image receiving layer or another water permeable layer adjacent thereto. There is. Therefore, in such a material,
The processing solution used in the development stage may be a so-called "alkaline activating solution" containing no developer.

The silver halide emulsion of the lithographic printing plate used in the practice of the present invention can use silver chloride, silver bromide, silver chlorobromide, silver chloroiodide, silver chlorobromoiodide, etc., and preferably silver chloride. Is 5
It is 0 mol% or more of silver halide. These silver halides are spectral sensitizers (light sources, spectral sensitizing dyes depending on the application,
For example, camera type, laser light type, color separation panchromatic type, etc. ), Gelatin hardening agents, coating aids, antifoggants, plasticizers, developers, matting agents and the like.

Binders for silver halide emulsions are the natural and / or synthetic binders generally used for this purpose.
For example, gelatin, colloidal albumin, cellulose derivative and the like can be used.

An undercoat layer for improving adhesion and / or an undercoat layer for the purpose of preventing halation may be included on the lower side (support surface) of the silver halide emulsion layer.
A matting agent can also be included.

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

The physical development nuclei used in the physical development nuclei layer are
Examples of this type of chemical are well known and include antimony, bismuth, cadmium, cobalt, palladium, nickel,
Metals such as silver, lead and zinc and their sulfides can be used. The physical development nucleus layer may also contain a developer and may contain a water-soluble binder.

The lithographic printing plate produced according to the present invention is, for example, Japanese Patent Publication No. 48-29723, US Pat. No. 3,721,539.
Ink receptivity can be converted or enhanced by a compound as described in the specification.

The printing method or the desensitizing liquid, the dampening liquid and the like to be used can be based on a commonly known method.

[0040]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. Example 1 A silver master (trade name) manufactured by Mitsubishi Paper Mills, Ltd. was used as a lithographic printing plate utilizing the DTR method. The lithographic printing plate precursor was imagewise exposed with a plate-making camera having an image reversing mechanism.

Then, in a room kept at about 25 ° C, 25 ° C
Place the image-exposed lithographic printing plate on a horizontal glass plate that was kept at a constant temperature, and use an infrared surface thermometer (Horiba Seisakusho Co., Ltd.).
It is confirmed by IT-330) that the surface temperature of the lithographic printing plate has reached a predetermined temperature, and each of the developing solutions shown below is dropped,
Spread with a doctor bar. Doctor Bar has a diameter of 5
A stainless steel rod having a diameter of 0.4 mm is wound with a wire having a diameter of 0.4 mm.

After the following developing solution was spread on the lithographic printing plate and left for 5 seconds to remove excess developing solution with a roller, it was subsequently immersed in the following neutralizing solution and left for about 15 seconds. In the same manner, excess neutralizing solution was removed with a roller. The plate was then dried.

Developer solution Potassium hydroxide 35.00 g Sodium hydroxide 15.00 g Sodium sulfite 20.00 g Ethanolamine 20.00 g Surfactant 1.00 g Water is added to make 1 liter.

Chemical formulas 5 and 9 of the present invention were used as surfactants, and chemical formulas 11 to 14 were used as comparative surfactants.
Further, a product processed by an automatic processor at 30 ° C. using a developer containing no surfactant (A), and a product coated and developed using a developer containing no surfactant ( B) was used as a comparison.

[0045]

[Chemical 11]

[0046]

[Chemical 12]

[0047]

[Chemical 13]

[0048]

[Chemical 14]

Neutralization liquid Water 600 ml Citric acid 10 g Sodium citrate 35 g Colloidal silica (20% liquid) 5 ml Ethylene glycol 5 ml Water is added to make 1 liter.

The lithographic printing plate prepared by the above operation was mounted on an offset printing machine, and printing was performed using the following desensitizing solution.

Desensitizing liquid Water 900 ml Isopropyl alcohol 400 ml Ethylene glycol 50 g 3-Mercapto-4-acetamide 5-n-heptyl-1,2,4-triazole 1 g

Wetting liquid Water 900 ml Potassium monophosphate 12 g Sodium nitrate 3 g Triethanolamine 2 g Colloidal silica 80 g Ethylene glycol 40 g

The printing machine is an AB DIC 350CD
(A, B, trademark of offset printing machine manufactured by Dick) was used. The number of printed sheets at the time when the image was not printed due to the background stain of the non-image area and the missing of the silver image and the image could not be printed. Photographic property: Good; good. Δ: The tone is soft. X: The tone is extremely soft. Ink acceptability: A; 1 to 10 sheets B; 11 to 20 sheets C; 21 to 30 sheets D; 31 to 40 sheets E; 41 to 50 sheets F; 50 sheets or more Printing durability: A; 40,000 sheets or more B: 30,000-40,000 sheets C: 20,000-30,000 sheets D: 15,000-20,000 sheets E: 10,000-15,000 sheets F: 5,000-10,000 sheets G: Less than 5,000 sheets Ink stain resistance: ○: No stain at all △: Light stain on the entire surface or part of × × Dark stain on the entire surface

The evaluation results are shown in Table 1.

[0055]

[Table 1]

Example 2 As in Example 1, except that Chemical Formulas 5 and 9 were used as the surfactants added to the developing solution and the amount was changed from 0.1 g to 3.0 g. The same was done.

The evaluation results are shown in Table 2.

[0058]

[Table 2]

Example 3 After each developer used in Example 1 was aged at 50 ° C. for 7 days, the same test as in Example 1 was conducted.

The evaluation results are shown in Table 3.

[0061]

[Table 3]

From the results, it is apparent that the developer containing the cationic surfactant or the anionic surfactant as shown in the present invention improves the coatability during development of the lithographic printing plate, and further the photographic properties of the lithographic printing plate. In addition, the printing durability and ink stain resistance have improved dramatically. The stability of the developer over time was also good.

[0063]

According to the developer of the present invention, it is extremely effective for the rapid processing developing method, and there are drawbacks such as reduction of printing durability and occurrence of ink stain, which are observed when the developer of the conventional system is applied. It is possible to rapidly make a large number of lithographic printing plates without using a small amount of developing solution.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Atsushi Urasaki 3-4 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Paper Mills, Ltd.

Claims (1)

[Claims] 1. A developer used in a method of coating and developing by supplying a necessary developer in a plate making method of a lithographic printing plate utilizing a silver complex salt diffusion transfer method, which is at least one of the following: A developer containing a cationic surfactant or anionic surfactant having a polyoxyethylene chain represented by the general formulas 1 and 2. [Chemical 1] [Chemical 2] In the formula, R1 is an alkyl group having 10 to 20 carbon atoms, R2
Represents an alkyl group or an aryl group having 5 to 20 carbon atoms. x, y, z are 5 <x + y + z <20, 1 <
x <15, 1 <y <15, 1 <z <15, and n is
7 <n <14. Further, X is an anion and M is a cation.