JPS60176044A - Silver salt lithographic plate material - Google Patents

Abstract

PURPOSE:To impart stable ink receptivity by forming, on a support together with other layers, a physical development layer obtained by dispersing a metal or metal sulfide into an aq. soln. of PVA saponified to >=96%, and spreading the obtained colloidal soln. CONSTITUTION:A layer contg. such an amt. of developing agent as capable of developing exposed silver halide in an activated alkaline bath is formed on a support by using the bead coating method and drying it. This layer is coated with a colloidal soln. prepared by dispersing a metal or metal sulfide into an aq. soln. of PVA saponified to >=96% with an air knife or the like to form a physical development nuclei layer. A silver salt lithographic plate material for silver salt diffusion transfer can be thus obtained. A support usable for said support is baryta paper, PE-coated paper, PP synthetic paper, or the like subjected to corona discharge treatment, subbing treatment, etc.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to the silver salt lithographic printing plate material in more detail.
This invention relates to a silver salt lithographic printing plate material with improved ink layer thickness and printing durability.

(Prior Art) Many methods have been known for producing lithographic printing plates using the silver salt encapsulant transfer method, and representative ones include U.S. Pat. No. 3,344,741; Same 3rd
．． No. 161,508, Special Publication No. 48-16725
The method described in the above publication is known. In addition, special public relations
There are also methods described in No. 6-42453 and No. 48-30562. In the former method, the photosensitive layer with the photosensitive layer and the photonucleus layer, which is an element of the printed image, are each made up of separate units, whereas in the latter method, they are integrated. It's technology.

Another method is the method described in U.S. Pat. No. 3,511,656 and U.S. Pat. No. 3,557,690. After diffusion-transferring the photographic material having the composition onto the lower layer printing element, the FJ- is finally eluted and peeled off with water to obtain a printing plate. A typical processing solution for a lithographic printing material using a silver salt ambiguous transfer method with such a light-sensitive silver halide emulsion layer and a physical layer (all major constituents of the nucleus layer) is current iron, crude drug, silver halide, etc. It contains at least a layering agent and an alkaline agent.

These processing solutions U9 are not only oxidized by oxygen in the air and deteriorate in performance, but also cause fatigue when the printing materials are continuously processed in large quantities, which deteriorates the photographic properties of the resulting printing materials. It is known that VC management has an unfavorable influence.

Therefore, one method for eliminating such drawbacks is to include a chemical compound in the constituent layers of the lithographic printing plate material in an amount necessary to make the exposed silver halide visible. Lithographic printing plate materials for so-called activator-type silver salt diffusion transfer methods, which can be treated with alkaline activated baths that are substantially free of chemical agents, are also known.

However, in a lithographic printing plate using such a silver salt diffusion transfer method, it is extremely important to improve the ink receptivity, that is, the ink receptivity at the heel of the silver image. Therefore, many techniques have been proposed for the purpose of improving the ink receptivity of silver paintings, such as improvements in the lithographic printing plate itself and improvements in processing agents. For example, in a lithographic printing plate having an integral structure as described above using the silver salt diffusion transfer method, the image is coated on the side closer to the support by performing the silver salt diffusion transfer phenomenon. The unexposed silver halide grains of the silver halide emulsion layer accumulate on the physical core of the physical core deposited on the upper side of the silver halide emulsion layer to form a reduced silver painter. However, when this silver image is formed, the more particles that become the nucleus of the phenomenon are present and arranged on the surface of the nucleus layer, the easier it is for lipophilic metallic silver to be formed on the surface. As a result, the ink receptivity, that is, the ink receptivity is improved.

For this reason, it is most preferable that the particles (for example, metal fine particles or metal sulfide fine particles) that serve as the phenomenon nucleus in the physical nuclear layer are exposed and arranged on the top surface without being buried in the layer as much as possible.

Therefore, improved techniques have been proposed in which the amount of binder used in the physical phenomenon nucleus layer is minimized to make it easier to arrange the existing nuclear particles on the surface.
448-3056t2, or polyvinyl alcohol with a saponification degree of 80 to 95 degrees was used for the physical nuclear layer!
It is described in many publications such as 1982-27151.

However, there are advantages as mentioned above)'! i-! It has also been found that in activator-type printing plate materials containing current active ingredients in the constituent layers, serious problems may arise in terms of printing properties if the above improved technology is applied. It has become clear that optically satisfactory printing plate materials cannot be obtained using improved techniques alone.

The above-mentioned problem is, for example, that depending on the phenomenon processing method of the printing plate material, differences may occur in the ink receptivity and printing durability of the printing plate.

In other words, the printing characteristics and printing durability V can be improved by processing one static phenomenon using one plate phenomenon and one agitation process using an automatic plate making machine.
Is there a big difference here? This causes a phenomenon in which printing durability is significantly deteriorated during processing using an automatic plate making machine, for example.

From this perspective, as a user of printing plate materials, I would like to:
There has been a strong desire for a lithographic printing plate material that has stable ink receptivity and printing durability no matter what type of darkening treatment method it uses.

(Object of the Invention) Therefore, the object of the present invention is to provide a silver salt lithographic printing plate for the silver salt diffusion transfer method, which can always provide stable ink receptivity and long printing life no matter what phenomenon processing method is used. All materials are provided.

(Structure of the Invention G) For the purpose of the present invention, a physical nucleophobic layer and an amount of nucleophobic layer that allows exposed silver halide to be oxidized in an alkali activation bath are provided.
In a silver salt lithographic printing plate material for a silver salt diffusion transfer method having a constituent layer containing a fast main system on a support, the physical property 1
Achieved by a silver salt lithographic printing plate material in which the crystal nucleus layer is a layer formed by applying a colloidal solution of a metal or metal sulfide dispersed in a polyvinyl alcohol aqueous solution having a saponification degree of 961 or higher. can do.

The invention will now be described in more detail.

The silver salt lithographic printing plate material of the present invention (hereinafter referred to as the printing plate material of the present invention) includes a photographic layer carrying a photosensitive layer and a photonucleus layer that becomes one photoelement of a printed image. This includes a wide range of products, including those in which each is constructed as a separate unit or one in which each is constructed as an integrated unit. After diffusing and transferring one silver painting to the artist's base,
The uppermost photosensitive layer is peeled off using water to form printing plate 7.
This also includes methods of obtaining such information.

In the present invention, a lithographic printing plate material having a structure in which an antihalation layer, a silver halide emulsion layer, and a physical phenomenon nucleus layer are coated in order from the support side is more preferred.

The above-mentioned antihalation layer is a colored layer containing a thick film filter dye, an antihalation dye, a pigment, etc. used in ordinary photographic materials.

The antihalation layer in the present invention is, for example, US Pat. No. 2.274.782, US Pat.
No. 3, No. 2.956,879, No. 3.177.0
78, No. 3.252.921, and the compounds described in Japanese Patent Publication No. 39-22069? May contain. These dyes are optionally available in U.S. Patent No. 3.
It may be mordanted by the method described in No. 282.699. In addition, as the antihalation layer, a pigment (
For example, colorants such as Lang black, carbon black, fast black, ultramarine, malachite green, crystal violet) can also be used.

Additives that are usually added to emulsions, such as anti-capri agents, matting agents, and surfactants, can also be used.

The photosensitive silver halide emulsions used in the present invention include silver chloride, silver bromide, silver iodide, silver chlorobromide, and silver chloride, which are generally used in silver halide photographic materials. It is selected from silver oxide, silver bromoiodide, and mixtures of two or more thereof. The type of emulsion may be either a negative emulsion or a positive emulsion. For example, the surface of the emulsion may be made of photosensitive silver halide and a hardening agent, which is more easily archable than the silver halide. It may also be a special emulsion of the type described in JP-A-54-48544, which consists of substantially non-photosensitive metal salt particles which have been rendered opaque to some extent.

These silver halide emulsions are chemically sensitized with sulfur sensitizers, selenium sensitizers, noble metal sensitizers, reduction sensitizers, polyalkylene oxide thread sensitizers, etc. as necessary. Ru. Furthermore, if necessary, spectral sensitization can be performed using various sensitizing dyes, and generation of capri can also be prevented by using known stabilizers such as imidazoles, triazoles, and azaindenes.

Furthermore, if necessary, hardeners, antistatic agents, antioxidants,
Preservatives, dyes, matting agents, N11If agents, grain quality improvers, surfactants, thickeners, ultraviolet absorbers, etc. can be used.

As the binder for the antihalation layer and silver halide emulsion layer, commonly used binders can be used, such as gelatin, gelatin derivatives, polyvinyl alcohol, and anhydrous maleic.

Examples include copolymers of acids and vinyl compounds and ester compounds thereof.

Preferred examples of the hardening agent having the above structure include formaldehyde, glutaraldehyde, glyoxal, etc., and these may be used alone or in combination of two or more, and if necessary, they may be used in combination with the fl11a hardening agent. You may. These hardeners can be used directly or with water,
It may be added to the layer coating solution for the above-mentioned constituent layers in an organic core medium or the like, or it may be added at any stage of the coating process.

According to the present invention, the constituent layers of the printing plate material of the present invention contain a herbal medicine that enables the exposed silver halide to be developed in an alkaline activation bath.

In this case, the exposed film can be activated using an alkaline aqueous solution.

The present iron base agent can be incorporated into the silver halide photosensitive layer or its adjacent layers (undercoat layer, intermediate layer, antihalation layer, release layer), etc. Incidentally, the alkaline activation bath may naturally contain a phenolic agent.

Specific compounds of the current ironing agent include polyhydroxobenzenes such as hydroquinone, catechol, chlorohydroquinone, pyrogallol, bromohydroquinone, isoglobilhydroxyne, tolu'hydroxy/, methylhydroquinone, and 2,3-dichlorohydroquinone. , 2.5
-dimethylhydroquinone, 2,3-dibromohydroquinone, 1゜4-dihydroxy-2-acetophenone, 2,
5-dimethylhydroquinone, 4-phenylcatechol,
4-t-butylcatechol, 4-n-butylpyrogallol, 4.5-dibromocatechol, 2.5-diethylhydroquinone, 2,5-benzoylaminohydroquinone,
Included are 4-benzyloxycatechol, 4-n-butoxycatechol, and the like.

Among these, hydroquinone and methylhydroquinone are particularly preferably used.

In addition, as the current main drug of So, 3-pyrazolidone compound such as LflJ is 1-phenyl-3-pyrazolidone-
11-p-tolyl-3-pyrazolidone, 1-phenyl-
4-methyl-3-pyrazolidone, 1-phenyl-4,4
-dimethyl-3-pyrazolidone, 1-p-chlorophenyl-3-pyrazolidone, 1-p-methoxyphenyl-3
-pyrazolidone, 1-phenyl-2-acetyl-3-pyrazolidone, 1-phenyl-5,5-dimethyl-3-pyrazolidone, 1-〇-chlorophenyl-4-methyl-4
-ethyl-3-pyrazolidone, l-m-acetamidophenyl-4,4-diethyl-3-pyrazolidone, 1.5-
Diphenyl-3-pyrazolidone, 1-(m-tolyl)
-5-phenyl-3-pyrazolidone, 4,4-dihydroxymethyl-1-phenyl-3-pyrazolidone, 4,4
-dihydroxymethyl-1-tolyl-3-pyrazolidone, 4-hydroxymethyl-4-methyl-1-phenyl-
Included are 3-virazolidone, 4-hydroxymethyl-4-methyl-1-(p-chlorphenyl)-3-virasoliton, and the like.

Examples of amine phenols include p-(methylamine)phenol, p-aminephenol, 2,4-diaminophenol, p-(benzylamino)phenol, 2-methyl-4-aminophenol, 2-hydroxymethyl-4 -Aminophenol, etc. can be mentioned.

It can be used alone or in combination with the above-mentioned herbal medicines. In particular, a combination of polyhydroxybenzene (1 compound) and a 3-pyrazolitone compound is preferable.The usage of the current main drug in the constituent layers is not uniform, but 0.001.9% per 1 compound is used. - II, and in the case of a silver halide photosensitive layer, it is used in the range of H0,01,9 to 3,9/1 g of silver halide.

In addition, in the constituent layers of the printing plate material of the present invention, if necessary, a compound called a complexing agent, which easily forms a soluble silver complex salt with silver halide in the unexposed area, is added to the layer to facilitate physical development. It can be advantageously promoted.

The printing plate material of the present invention preferably has a physical layer (a core layer) on the above-mentioned antihalation layer and silver halide emulsion layer, although the layer structure is not specified. According to the invention, the physical core layer is formed by applying a colloid of a metal or a metal oxide dispersed in an aqueous polyvinyl alcohol solution having a degree of saponification of 96% or more. Characteristics.

That is, the physical core of the physical core layer according to the present invention includes metals such as antimony, bismuth, cadmium, cobalt, palladium, nickel, gold, silver, zinc, etc., and known nuclei such as sulfides of these metals. ? It may be a colloidally dispersed layer, specifically /ruvar]-ride,
7' If you want.

Process, (Focal Press, 1972) 54
The methods described on pages 57 to 57 can be applied.

In the present invention, as described above, colloid I (polyvinyl alcohol having a saponification degree of 96% or more was used as an inder) for dispersing metal or metal sulfide in colloidal form.

In the present invention, the above-mentioned polyvinyl alcohol may be used alone, but it may also be used as a reaction product with a copolymer of a vinyl compound represented by the following general formula and maleic anhydride.

In the general formula, R7-[represents a hydrogen atom, a methyl group, a methoxy group, or a phenyl group. Among the above substituents, a methoxy group is most preferred, and such a compound is commercially available from Rikyo Sangyo Co., Ltd. under the trade name ``1 GANTORETSU''.

The above reaction between Gantrett and polyvinyl alcohol can be easily obtained by dispersing each in water in an arbitrary ratio and heating the mixture to 85° C. or higher while stirring.

The above reaction can be stopped by cooling when the desired viscosity is reached, and the pH is adjusted as necessary.

Polyvinyl alcohol used in the present invention (
Kuraray Co., Ltd., Denki Kagaku Kogyo (Koshi, Nippon Gosei Chemical Industry @)
They are commercially available under product names such as ``Kurarayboval,'' ``Denka Poval,'' and ``Gohsenol,'' but they are also given detailed product names based on their degree of polymerization, degree of saponification, etc. There is.

-e Polyvinyl alcohol Vinegar can be synthesized by hydrolysis of vinyl, but its properties are largely determined by the number of hydroxyl groups rather than the degree of polymerization, and therefore the degree of saponification is very heavy.

For example, Japanese Patent Application Laid-Open No. 56-27151 discloses a DM method for a printing plate material having a saponified layer of 80 to 95 thick polyvinyl alcohol all around it as a physical core layer of the printing plate material.

Bolivinyl alcohol with a degree of saponification of 7"1 has excellent bath dissolution in water, and at relatively high concentrations, sol formation occurs compared to those with a high degree of saponification, and it is also highly colloidal. It is also in good condition, and it is certainly too dredged to show the colloidal bath liquid of the physical toge core. However, according to the research conducted by the present inventors, regarding the ink layer adhesion, especially the ink adhesion when plate making using an automatic plate making machine, printing made using polyvinyl alcohol with a high degree of saponification The printed version is much better.

The reason for this is not necessarily clear, but it is thought that the decrease in polyvinyl alcoholoid properties with a high degree of saponification is rather suitable for arranging physical nuclear particles on the surface of the printing plate.
It is assumed that one of the reasons for this is that polyvinyl alcohol with a high degree of saponification has a high nucleation film ability, or that the film has low water absorption. According to Kennami, the inventor of the present invention, when cleaning a printing plate using an automatic plate-making machine, the automatic cleaning of the plate material itself occurs regardless of whether or not the processing solution is stirred.
The F feeding adds a stirring effect, making it easier for silver particles to be formed on the surface due to diffusion transfer, compared to the static appearance in the secondary plate pattern.

Therefore, printing plates obtained using automatic plate making machines have good initial ink receptivity, but the silver particles tend to peel off easily, making it difficult to obtain sufficient printing durability.

However, as in the printing plate material of the present invention, by using so-called completely saponified type I polyvinyl alcohol with a degree of saponification of 96% or more as a binder for the physical phenomenon core layer, the wear resistance of the layer is improved. Furthermore, since the hardening effect of the aldehyde hardener can be significantly exhibited, water resistance is also improved, and printing durability can be improved, which is an unexpected effect.

Examples of the support for the lithographic printing plate in the present invention include baryta paper, polyethylene-coated paper, polypropylene-based paper, glass plate, cellulose acetate, cellulose nitrate, and polyethylene terephthalate, which have been subjected to corona discharge treatment, subbing treatment, etc. Examples include polyester films, polyamide films, polypropylene films, polycarbonate films, polystyrene films, metal plates such as anodized aluminum plates, and Fs metal foil laminated paper.

These supports can be transparent or opaque depending on the purpose of the forest material. It can also be colored and made transparent using dyes or pigments.

The opaque support is typically paper, but it also includes paper made light-shielding with carbon black, dyes, pigments, etc., and glass films.

Further, the entire back surface of the support can be roughened with a matting agent to make it difficult to scratch.

The constituent layers of the printing plate material of the present invention may be coated on the above-mentioned support by coating using a coating method well known in the art, such as dip coating, air knife coating, extrusion coating, etc. A doctor method, bead coating method, etc. can be used.

According to the present invention, the entire hydrophilic colloid layer excluding the physical core layer is coated by bead coating method, and after drying, the physical core layer is coated on this layer by the air knife method. is preferred.

When coating the above-mentioned constituent layers, it is preferable to add a known coating aid to the head cloth solution.

These coating aids include natural products such as saponin, anionic or nonionic surfactants such as alkylene oxide, glycerin, glycidol, and fluorine surfactants, higher alkylamines, 4e, ammonium salts, and heterocycles such as pyridine. cationic surfactants such as phosphonium or sulfonium, 7=one surfactants with acidic groups such as carboxylic acids, sulfonic acids, phosphoric acids, sulfuric esters, phosphoric esters, amino acids, aminosulfonic acids, amino alcohols ampholytic active agents such as sulfuric acid or phosphoric acid esters.

Some examples of surfactant compounds that can be used include U.S. Pat. Nos. 2,271,623 and 2,240.
No. 472, No. 2.288, 226, No. 2.739
, No. 891, No. 3,068,101, No. 3.15
No. 8.484, No. 3,201.253, No. 3.2
No. 10.191, No. 3,294.540, No. 3.
No. 415.649, No. 3.441.413, No. 3
．． No. 442,654, No. 3,475.774, No. 3.545.574, British Patent No. 1.077.317
No. 1,198.450, as well as the specifications, "Synthesis of surfactants and their applications" by Ryoheiike Odara (Maki Shoten, 1964), and part of "Surface Active Agents" by A., W. Peri. ” (Interxienspaglication Incorporated.

1958), J. P. Sisley [Encyclopedia of Active Agents, $2 Volume] (Chemical Publishing Co., Ltd., 1964).

Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1 Coating solutions having the following compositions were prepared as an antihalation layer and a silver halide emulsion layer, respectively.

(Composition of antihalation layer coating liquid) [Liquid A] Carbon black (4% solids dispersion) 150# gelatin 45, ? Water 40011L [Liquid B] Sapo = y (10% water heart fluid) 10ml Matting agent (silica, Thyroid 308) 10,? Water 300rI
Ll [Class C] Dimaison 1.5I Hydroquinone 7.0g 7' Evening/-) L/ Finish into 100 catfish with 40.01nl water.

[Liquid D]

Formalin 35% solution 6. □ntl Finish to 100% with water.

The above [Liquid A], [Liquid B] and [Liquid C] are mixed in sequence, the pH is adjusted to 4.5, and [D] is added in-line just before coating.

(Preparation of silver halide emulsion coating solution) A pure silver chloride emulsion prepared by a conventional mixing method was chemically ripened using a chemical sensitizer, and ortho-sensitized using an optical sensitizer. After the ripening was completed, appropriate amounts of 4-hydroxy-6-methyl-1,3.3a,7-chitrazaindene compound and potassium bromide were added as stabilizers. Furthermore, as a coating aid, inamyl-n-decylsulfokono1
Appropriate amount of sodium phosphate and fine silica powder (Thyroid 308) as a matting agent 90.2 ft per Ig of gelatin
11) After washing, the pH was adjusted to 4.5. Note that the concentration of gelatin was 6%.

Each of the antihalation coating solution obtained above and the coating solution for silver halide emulsion obtained above,
On a polyethylene paper support having a thickness of 135.9 mm, an antihalation layer is applied as a layer close to the supporting body, that is, as a lower layer, and a silver halide emulsion layer is applied as an upper layer, and the layers are coated simultaneously using a bead coating method and dried. did.

The resulting two-layer coated sample was seasoned (40
After leaving it for 3 days at 45° C.RH (1 ton), a coating solution for a physical development nucleus layer having the following composition was further applied to the upper layer by an air knife method and dried to prepare a printing plate material.

(Composition of strong cloth liquid for physical phenomenon 1 nucleus layer) [A cause] Binder (see below) 0.13 g Water 750 ml [B solution] HAuCl4 4H200-8,9 Water 50R1 [C solution] NaBH40,4,9 Water 200 ml After mixing the above [Liquid A] and [By] at room temperature, while stirring strongly, [Liquid C] was added to the tube and reduced to prepare gold colloid liquid M.

The following four types of polyvinyl alcohols were used as the binder.

(1) Ri5 V HopZ-le pVA-215 (saponification degree 81) (2) Reaction product of Kuraray Bobal pVA-215 and Gantolets (3) Ri 5 V Hohar pVA-110 (saponification!
98.5%) (4) Kuraray Boval pVA-11
0 and Gantretz's reaction product Inamyl-n was added as a coating aid to the gold colloid m solution mentioned above.
- Added appropriate amount of sodium glucylsulfosuccinate.

The prepared printing plate material was subjected to a static phenomenon and an automatic plate making machine (
IPA-300 manufactured by Aitchik Co., Ltd.
Development-stabilization treatment was performed.

The composition of the treatment liquid used is as follows.

(alkali activation g,) Caustic potash 25 II Anhydrous sodium sulfite 50.9 Sodium thiosulfate 31I 2-Mercapto-5-methyl- Oxadiazole 0.1g Finish with water to 1000-.

(stabilization bath) citric acid sodium citrate Add water to make it 1000m.

The treated printing plates were printed using an offset printing machine (Gestettner 200, manufactured by Gestettner), and the results are shown in Table 1 below.

In addition, the ink layer thickness shown in the table is determined by bringing the water roller into contact with the plate surface, supplying sufficient water, and then feeding the paper first. After starting, the ink roller was brought into contact with the plate surface, and the number of prints until a good print was obtained was evaluated.

◎: less than 10 sheets 0: 10 or more sheets less than Δ: 20 or more sheets Groove and printing durability were evaluated by continuously printing risoo sheets.

◎There is no drop in the knee iron, no small spots, etc.

A decrease in 0:1 tan density and some small dots are observed.

Δ: Deterioration in image quality and small dots are quite noticeable.

Table 1 As is clear from the above table, in the sample of the present invention using polyvinyl alcohol with a degree of saponification of 96% or more as the binder of the physical core layer, static plate making and automatic plate making It is possible to obtain printing properties 7 which are superior to those of the comparative samples in terms of both machine-induced effects.

Example 2 A printing plate material was prepared in the same manner as in Example 1 except that the coating composition of the physical slag core layer was changed to the following formulation.

(Coating liquid composition for physical phenomenon 1 phenomenon nucleus layer) [Liquid A] Binder 0.2g Water 434m1 [Liquid B] 1) eLC40-7f IN-HC! 7 5.3ml Water 150- Heat at 50°C for 10 minutes, and after dissolving, cool.

[Liquid C]

Na, 5-9H, Q 1.4 g Water 4001rLl After mixing the above [Liquid A] and [Liquid B], stir at 15°C [
Add [Liquid C]. After the addition reaction, it was purified by ultrafiltration.

The following two types of polyvinyl alcohol were used as the binder.

(1) f Tsukapoval B-20 (Saponification degree 87-89%
) and Cantrez reaction product (2) Denkapoval K-20 (saponification degree 97.5
98.5%) and Cantrez. Isoamyl-n-7 is added as a coating aid to the above-mentioned physical phenomenon 1 nucleus layer coating solution.
'Sodium Silsulfosuccinate Society JI! Il Shun added. The prepared printing plate samples were processed as in Example 1 and the excellent results are shown in Table 2 below.

Table 2 From what is shown in the above table, in the sample of the present invention using polyvinyl alcohol with a degree of saponification of 96% or more according to the present invention as the binder of the physically simulated nuclear layer, the types of physically simulated nuclei are different. Even if it changes, it remains still and the current e1 produced by the automatic plate making machine! It was also found that superior printing characteristics could be obtained in both cases compared to the comparative samples.

(Effects of the Invention) The silver salt lithographic printing plate material according to the present invention, which has a physical phenomenon (I) (inner is polyvinyl alcohol with a degree of saponification of 96% or more) in the core layer, exhibits a static phenomenon and automatic Excellent ink receptivity and printing resistance can be obtained during processing using a plate-making machine.

Agent Patent Attorney No 1) Parent-in-law

Claims (1)

[Claims] A method for use in silver salt diffusion transfer method having on a support a core layer that exhibits a physical phenomenon, and a constituent layer that completely absorbs an amount of the current iron base agent in an amount that enables the exposed silver halide to be developed in an alkaline activation bath. In the silver salt lithographic printing plate material, the physical iron core layer has a saponification degree of 96
% or more of a polyvinyl alcohol bath solution.