JPH0412353A - Processing method for planographic printing plate - Google Patents

Abstract

PURPOSE:To uniformize processing and to simultaneously shorten the time for processing by processing the above printing plate with a compsn. contg. an acetylene glycol compd. CONSTITUTION:The printing plate is processed by the compsn. contg. the compd. in which two pieces of the carbons adjacent to the triple bonds of alkine have respectively one piece of hydroxyl group, i.e. the acetylene glycol compd. The acetylene glycol is expressed by fromula I. In the formula I, R1 preferable denotes a methyl group; R2 preferably denotes up to 4C alkyl group. The ease of foaming of a converting liquid is lessened in this way and the processing with the excellent uniformity of processing and uniform ink receptivity is possible.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Industrial Application Field The present invention relates to the processing of lithographic printing plates produced in a novel manner from photographic silver halide materials. Furthermore, the present invention makes the process uniform, suppresses foaming, and speeds up the process in lithographic printing plate processing in which a photographically formed silver halide image is applied to make it oleophilic and ink receptive. The present invention relates to a method for making processing possible.

CB) Prior art and its problems A lithographic printing plate consists of an oleophilic image area that accepts oil-based ink; and an oil-repellent non-image area that does not accept ink; consists of a hydrophilic part that receives water.

In normal lithographic printing, therefore, both water and ink are supplied to the plate surface, and colored ink is selectively received in the image area and water is selectively received in the non-image area, and the ink on the image line is, for example, This is done by transferring it to a substrate such as paper. Therefore, in order to obtain good printed matter, the difference in lipophilicity and hydrophilicity between the surface of the printed area and the background non-printed area must be sufficiently large, so that when water and ink are applied, the printed area has a sufficient amount. It is necessary to apply ink to the non-image areas, and not to apply any ink to the non-image areas.

The processing method for lithographic printing plates basically described in Japanese Patent Publication No. 57-3939 is similar, in which a material having a light-sensitive silver halide emulsion layer is imagewise exposed and subjected to the usual photographic development process. After that, the portions that were not reduced by development, that is, the remaining silver halide image portions, are treated in the presence of an organic compound that reacts with silver ions to form a releasable compound to make the unexposed surface surface ink-receiving. However, in the above treatment method, the material is brought into contact with a composition solution (hereinafter referred to as a conversion solution) containing an organic compound that reacts with silver ions to form a poorly soluble compound and a silver halide solvent. This method has disadvantages in that it tends to cause uneven contact with the conversion liquid, and it tends to cause uneven ink receptivity in the ink receiving portion, resulting in uneven ink up time and uneven ink coverage.

Furthermore, the conversion liquid described above has the property of being prone to foaming due to the organic compounds it contains, and the conversion liquid does not come into contact with areas where air bubbles have adhered, resulting in areas where ink does not get on. Ta. This tendency is particularly strong in rapid processing using automatic processors, and improvements have been desired.

(C) Object of the Invention An object of the present invention is to provide a method for processing a lithographic printing plate that does not have the above-mentioned drawbacks, has uniform ink receptivity, and is capable of rapid processing using an automatic processor.

(D) Structure of the Invention The present invention discloses that after a photographic light-sensitive material having at least one silver halide emulsion layer is exposed and developed according to the image, the undeveloped silver halide remaining in the unexposed area is reacted with silver ions. For the treatment of lithographic printing plates in which the unexposed surface of the plate is treated in the presence of an organic compound and a silver halide solvent that can be converted into a silver salt with lower solubility (smaller solubility product) to make the surface of the unexposed area ink receptive. The above object was achieved by treatment with a composition containing an acetylene glycol compound.

In the method of the present invention, when the conversion process was carried out using an automatic developing machine for phototypesetting paper, it was found that the processing time was significantly shortened and rapid processing became possible. The superiority of the conversion processing method of the present invention is demonstrated by the fact that the completely unexpected effect of shortening the processing time as well as making the processing uniform with the automatic processor was obtained.

Acetylene glycol has an acetylene bond (
It is a compound having a carbon-carbon triple bond) and an alcohol (ROH: R is an alkyl group), and in particular, acetylene glycol as referred to in this specification is a compound in which two carbons adjacent to the triple bond of an alkyne each have one It is a compound characterized by having a hydroxyl group, and has, for example, the following formula (1).

A particularly preferable example of acetylene glycol is the formula (4
] to which ethylene oxide is added.

OH0H R1 is preferably a methyl group, R2 is preferably a carbon number of 4
Indicates an alkyl group up to.

Specific examples of formula (1) are shown by the following formulas (2) and (3), for example.

H5CH3 (n+m=N represents the number of moles of ethylene oxide added, preferably 10 or more.) These acetylene glycols are widely used as nonionic surfactants in the fields of painting, metal corrosion prevention technology, etc. However, it is said to have unique properties (for example, antifoaming properties) that ordinary nonionic surfactants do not have.

The acetylene glycol used in the present invention is manufactured by Air 9 Products and Chemicals, Inc. in the United States, and manufactured by Nissin Chemical Industry ■.
It is sold under the product name ``ynol''.

The compound represented by the above formula (2) is surfinol 82
, the compound represented by formula (3) is surfinol 104
A, 104E, 104H (104A is a 50ft% solution of 2-ethylhexyl alcohol, 104E and 104H
are 50 and 75 fL% solutions of ethylene glycol),
The compound represented by formula (4) is surfinol 440.4
65.485 (440 is 3.5.465 is 10.4
85 is 30. ) is the product name.

In addition, Surf Inol 104 and polyoxyethylene
Examples include Surfynol TG, which is an alkyl phenyl ether dissolved in ethylene glycol at a high concentration. Surfinol 82.465 and 485 are preferred because they have relatively high solubility in water.

However, other compounds can also be added in relatively sufficient amounts by using miscible compounds such as alcohols, glycols, etc. as mentioned above.

Other surfactants can also be used in combination with acetylene glycol, such as Surfynol TG.

The surfactants include sodium isopropylnaphthalene sulfonate, dioctersodium sulfosuccinate, polyoxyethylene octylphenyl ether,
Polyoxyethylene nonylphenyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene floc copolymer, polyoxyethylene nonylphenyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene nonylphenyl ether /ethylenediamine adducts and the like. In particular, polyoxyethylene alkyl sulfates are preferred because they do not crystallize even in conversion solutions with high ionic strength.

The purpose of the present invention can be fully achieved with the amount of acetylene glycol added to the conversion liquid in an amount of 0.01 to 10% by weight of the conversion liquid used, but depending on the case, the amount added may be other than this. is possible.

When a photosensitive material having a silver halide photographic layer is a hydrophobic support, droplets may adhere to the surface of the support after conversion treatment, causing inconvenience in handling. However, according to the conversion liquid composition of the present invention, , has the advantage of eliminating droplet adhesion due to the excellent surface tension lowering ability of acetylene glycol.

In the present invention, as detailed in the above-mentioned Japanese Patent Publication No. 57-3939, there is a wide range of combinations of organic compounds and silver halide solvents that make the unexposed surface oleophilic, but particularly preferred are silver halide solvents. The solvent (converting agent) is iodide, which is supplied in the form of sodium, potassium, and ammonium salts.

The organic compound is preferably one represented by the following general formula.

General formula (I) Among the compounds of general formula (I), those represented by -numerical formula 徂) and (2) are particularly preferred.

General formula (I[) H-R3 (In the formula, R142 represents hydrogen, an alkyl group, an aryl group, or an aralkyl group. R3 represents hydrogen, acyl, or an arylsulfonyl group.) General formula (II), (2) Typical compounds represented by are specifically exemplified below.

(In the formula, Z represents the remaining atomic group necessary to form a 5- to 6-membered heterocycle together with J The amount used is not uniform depending on the halogen composition of the silver halide emulsion, but is within the range of 10@-2 mole/l@-1 mole/1. The amount of the organic compound is not necessarily uniform for each compound, but is used in a concentration of 10 mol/l-10-1 mol/l.

The processing composition liquid (conversion liquid) containing an organic compound and a silver chloride solvent for lipophilization is used to improve the solubility of the organic compound, such as methanol, ethanol, furopanol, ethylene glycol, diethylene glycol, etc. water-miscible organic solvents.

Moreover, it is preferable that the conversion liquid is buffered to a pH of 4 to 80. As a pH buffer, acetic acid, citric acid,
It can be selected from acids such as phosphoric acid and their salts. Further, the conversion liquid may contain various other components. For example, it may contain water-soluble polymers such as hydroxyethyl cellulose, surface hydrophilic agents such as colloidal silica, and the like.

According to the method according to the invention, the areas of the photographic material which correspond to the steel metal images, but not those areas containing undeveloped silver halide, are made to receive ink. Positive-working printing plates are therefore obtained by imagewise exposure of a negative-type silver halide material and, after development, treatment with a conversion liquid according to the invention. Also, negative-working printing plates can be obtained from directly positive-type silver halide materials.

Furthermore, according to another embodiment, the silver halide light-sensitive material is developed and then fixed, or the silver image remaining after bath development and fixing is oxidized and rehalogenated, and by the method according to the invention, The silver halide image areas can be made ink receptive.

In the method according to the invention for producing the lithographic printing plate of the invention, the photographic material comprising a silver halide emulsion may contain iodide with silver chloride, silver chlorobromide, silver bromide. The binder for the photosensitive material is preferably gelatin. However, part or all of it may be substituted with other colloidal substances, such as albumin, casein, polyvinyl alcohol, polyvinyl alcohol maleic anhydride, polyvinyl alcohol styrene maleic anhydride estenopearginate, cellulose derivatives, etc. .

The weight ratio of binder, preferably gelatin, to silver halide and the absolute amount of binder are important factors in determining the quality of the printing plates of the present invention.

The amount of binder is preferably between 0.3 and 2.0 when the amount of silver halide expressed as silver nitrate is 1. If the ratio of the binder is less than 0.3, the film strength as an emulsion layer tends to decrease, and unfavorable printing characteristics tend to occur. On the other hand, when the ratio of binder increases, the ink acceptance ability may decrease. The silver halide emulsion layer is 0.6 to 7t in terms of the amount of silver nitrate, and 0.5 in terms of the amount of β binder.
Preferably, it is applied at a thickness of ~2.5 mm.

Another important factor in the production of the printing plates of this invention is the hardening of the light-sensitive silver halide emulsion layer.

It must be sufficiently cured at least before printing ink is applied. A hardening agent may be added to the photographic emulsion coating solution in the same manner as in the conventional hardening method for photographic emulsion layers, or
It may be hardened by a method such as heat treatment before or after development and plate-making processing. In order to obtain stable curing characteristics, it is preferable that a silver halide emulsion containing a hardening agent is coated and dried, followed by an appropriate heating treatment. This heating process is
This is a treatment to obtain a good degree of hardening, for example 80
~150℃ for several minutes or tens of minutes, or 30-
The treatment may be performed at 50° C. for several days (about 1 to 20 days).

As the hardening agent, compounds commonly used as hardening agents for photographic emulsion layers can be used. For example, aldehyde curing agents such as formalin, glyoxal, glutaraldehyde, mucochromic acid, urea-formalin striped compounds, melamine-formalin condensates are also effective, and epoxy-based, aziridine-based compounds, active olefins, Known compounds as hardeners for photographic emulsion layers, such as organic hardeners such as incyanate compounds, and inorganic polyvalent metal salts such as chromium, aluminum, and zirconium, can be used alone or in combination.

Furthermore, in order to prevent abrasion of the colloid during printing, the silver halide photographic emulsion layer preferably contains fine particles having a diameter of about 2 to 10 μm, and the fine particles include silica, clay, etc. , talc, gicrite, rice starch, etc. can be used, but silica, which is an oxide of silicon, is particularly preferred.

Silica is added to the silver halide emulsion coating at 0.019 to 1.0 grams per square meter. If the silica particle density becomes too high, it becomes difficult to increase the ink concentration during printing, or a scumming phenomenon occurs. For the purpose of improving the photographic sharpness and ultimately the resolution and sharpness of the printed matter, it is preferred to apply so-called antireflection dyes or pigments. These are present in the photographic silver halide emulsion layer, in the so-called antireflection layer between the support and the silver halide emulsion layer, in the support, or in the silver halide emulsion layer with the support in between. The purpose is achieved by applying in the opposite layer.

The object can also be achieved by using a light-reflecting pigment, such as a white pigment such as titanium oxide, barium sulfate, or magnesium oxide, or a yellow organic pigment in combination with a light-absorbing dye or pigment.

The most preferred embodiment of the photographic light-sensitive material in the method for producing a printing plate of the present invention is to have a colloidal undercoat layer containing an antireflection dye or pigment on the support, and a light-sensitive silver halide emulsion layer on the support. has.

The colloidal subbing layer with anti-reflective dye or pigment preferably comprises gelatin and has a particle size of about 2 as described above.
Contains particles of ~10μ.

A preferred particulate is silica. Gelatin is a binding agent,
0.5 to 2.5 grams per square meter,
It should harden as well as the silver halide emulsion layer. Also, silica is 0.1 grams to 2 grams per square meter.
Granted between 0 grams.

The undercoat layer containing fine particles as in this configuration has the effect of improving the abrasion properties of the colloid during printing and, in turn, improving the printing durability. In this case, fine particle silica is not necessarily required in the emulsion layer.

The support for the light-sensitive silver halide emulsion can be any support commonly used in the art. For example, the support may be paper, resin film, or metal sheet. The paper support is preferably coated on both sides with a resin coating, for example polyethylene. These supports are previously subjected to corona discharge machining, hydrophilic undercoating, etc. for the purpose of improving adhesion between coating layers mainly composed of gelatin.

Above, the lithographic printing plate of the present invention and its manufacturing method have been basically described, but in addition to the photosensitive silver halide material, for example, a surfactant for improving coating properties, a stabilizer for maintaining photographic sensitivity characteristics, Anticapri agents, spectral sensitizers, developers and development accelerators, and dyes, pigments, and the like may optionally be included for the purpose of coloring the photographic emulsion layer.

In a modified embodiment of the present invention, part or all of an organic thiol compound or thione compound or other organic heterocyclic compound that imparts ink receptivity may be added in advance to the material having the silver halide emulsion layer. . It may be a layer other than the photosensitive silver halide emulsion layer. Alternatively, the organic compound may be added by being dissolved in an oil agent and dispersed in the form of minute oil droplets.

Exposure of the material having a silver halide emulsion layer can be carried out by conventional methods such as contact, reflection, and projection methods.

Materials with exposed silver halide emulsion layers can be developed with conventional photographic developers based on para-dihydroxybenzene-based developing agents, and also with lithium-type developer compositions containing only small amounts of so-called sulfites. can.

It is also possible to incorporate a developer into the photosensitive material and treat it with an activating solution consisting essentially of an alkaline solution.

In a preferred embodiment, the exposed and developed material is subsequently treated with a conversion liquid according to the invention.

The printing plate thus produced can be immediately mounted on a printing press, and after ink can be applied, printing can be performed. They can also be stored for long periods of time without inking.

In another embodiment, after the development process, the printing plate is treated with an acidic stop bath such as that used in the processing of conventional silver halide photographic materials, and then the conversion liquid according to the invention is applied to the printing plate, for example on a printing press. It can be applied on top and printed.

The most useful processing method is to use fully automated exposure processing equipment. For example, Silver Master System CP-404 fully automatic plate making machine (trade name of Mitsubishi Paper Industries) can be used.

In this apparatus, the material is supplied in rolls, exposed, cut into lengths, developed in a first bath, and subsequently processed in a second conversion bath according to the invention.

Development in the first bath is usually carried out at a temperature of 20°C to 35°C, but may be performed at a higher temperature. The processing time depends on the temperature of development, but 15 seconds at 30° C. is usually sufficient. The conversion bath treatment in the second bath is usually carried out at room temperature (18°C to 25°C). The processing time for this layer has little effect on printing properties, and a processing time of 5 seconds to 20 seconds is sufficient.

The treated printing plate is then squeezed out of excess liquid by a rubber roller and left as is.
It can be attached to a printing machine and printed. Another advantage of the printing plate of the present invention is that the image can be easily modified and erased.

The liquid composition shown in Japanese Patent Publication No. 51-15761 and Japanese Patent Application Laid-Open No. 51-21901, that is, a liquid composition containing an organic compound having at least one mercapto group or thione group and at least one hydrophilic group in the same molecule, is used for the purpose. Can be used for

The present invention will be specifically described below with reference to Examples, but is not necessarily limited thereto.

(E) Examples Example (1) 1'I) Preparation of lithographic printing material A gelatin undercoating solution containing silica particles (average size 5 μm) and carbon black was coated on corona discharge machined polyethylene coated paper. Further, formalin and dimethylol urea were added as colloid hardening agents. The amounts of gelatin and silica deposited were 1.2 grams and 0.7 grams per square meter, respectively. In addition, the core layer showed a reflection density of 0.9. Subsequently, an ortho-sensitized, high-contrast silver halide emulsion containing formalin and dimethylol urea as colloidal hardeners was coated onto the undercoat layer.

The emulsion layer had the following structure.

After heating the photosensitive silver halide emulsion-containing photographic material at 40° C. for 3 days, an aqueous solution containing a water-soluble synthetic polymer substance having the following formulation was applied to the back of 15 books and dried by heating to obtain a lithographic printing material. It was created.

(I[) Processing After image-wise exposure of the photosensitive material, Kodak D-7
After developing by immersing it in a 1=1 dilution of two developers at 25° C. for 30 seconds, the excess developer was squeezed out. Subsequently, it was wet-etched in a conversion liquid having the following composition at 30° C. for 20 seconds, squeezed, and then dried to obtain a printing plate.

A liquid containing Surf-Inol 465 in the form of acetylene glycol in the form of 0.3 to 22% of the above formulation, a liquid in which 0.3 to 32 of Surf-Inol 485 as acetylene glycol was added, and a liquid in which 0.52 of Surf-Inol 82 was added;
One to which 0.32 of Surf-Inol 104E was added and one to which 0.3r of Surf-Inol 440 was added were simultaneously prepared.

(To) Printing method The printing plate thus obtained was printed on an offset printing machine Knee φB Dick 350CD (AIIB11Dick350).
CD (product name) and the surface of the plate is coated with etching liquid (SLM).
After wiping with -OH liquid (manufactured by Mitsubishi Paper Industries), printing was performed.

The printing room was at 22°C and 60% humidity. From the results in Table 1,
It is found that by treatment with a conversion liquid containing the acetylene glycol compound of the present invention, a lithographic printing plate with uniform ink receptivity, less foaming, and no uneven conversion treatment can be obtained.

Example (2) After exposing the photosensitive material of Example (1) according to the image, it was processed using a processor for phototypesetting paper (DF-305, manufactured by Mitsubishi Paper Mills ■).
1. Leakage of a 1:3 dilution of a computer phototypesetting paper developer (MRA-CD201, manufactured by Mitsubishi Paper Mills) and the conversion processing solution shown in Table 1.
4.9.11.12.13 were used in combination, and the printing plates were processed by changing the processing time by changing the conveyance speed dial at a liquid temperature of 35°C, and were printed by the method of Example (1). The results are shown in Table-2.

Table-2. Ordinary water was used as the wetting liquid, and F-Gloss MB manufactured by Dainippon Ink was used as the printing ink.

The results obtained here are shown in Table 1 below.

Table-1 (× Mold Δ Slightly uneven ○ No unevenness) (× Not possible Δ
From the results in Table 2, it can be seen that the time required to obtain a printing plate with good ink receptivity is shortened by treatment with the conversion liquid containing the acetylene glycol compound of the present invention. I understand.

(F) Effects of the Invention In the lithographic printing plate processing method of the present invention, the following effects were obtained by incorporating an acetylene glycol compound into the conversion treatment composition.

That is, the bubbling of the conversion liquid is reduced, the processing is excellent in uniformity, and a lithographic printing plate with uniform ink receptivity and stable processing can be rapidly provided.

Furthermore, the present invention is a method for processing a lithographic printing material that exhibits stable printing characteristics even over time (replacement) after plate-making processing.

Claims (1)

[Claims] After a photographic light-sensitive material having at least one silver halide emulsion layer is image-wise exposed and developed, undeveloped silver halide remaining in unexposed areas is reacted with silver ions and has a lower solubility (solubility In the treatment of lithographic printing plates in which the surface of the unexposed area is made ink receptive by processing in the presence of an organic compound that can be converted into a silver salt (with a low product density) and a silver halide solvent, the triple bond of the alkyne is A method for treating a lithographic printing plate, comprising treating it with a composition containing a compound in which two adjacent carbons each have one hydroxyl group.