JP2835715B2 - Method for producing physical development nuclei for use in silver salt diffusion transfer processing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] The present invention relates to a method for producing a physical development nucleus containing a heavy metal sulfide for use in a silver salt diffusion transfer process. In particular, the present invention relates to the production of physical development nuclei that can be used in producing an image forming material capable of producing a lithographic printing plate by a silver salt diffusion transfer method.

BACKGROUND OF THE INVENTION The principle of the silver complex salt diffusion transfer reversal method (hereinafter referred to as the DTR method) is described in, for example, US Pat. No. 2352014 and The Focal Press in London and New York, 1972, An.
Photographic Silv by dre Rott and Edith Weyde
er Halide Diffusion Processes.

In the DTR method, the undeveloped silver halide of a photographic silver halide emulsion layer material that has been exposed according to information is converted into a soluble silver complex compound with a so-called silver halide solvent, which is diffused into an image receiving material. In which, in the presence of physical development nuclei, is reduced with a developing agent to form a silver image (DTR image) having an image density value inverted from the black silver image obtained in the exposed area of the photographic material it can.

A DTR image bearing material has a DTR silver image area,
It can be used as a lithographic printing plate to form water repellent ink receptive areas on a water receptive ink repellent background. The DTR image is placed in an image receiving layer of a sheet or web material that is another material to the photographic silver halide emulsion material (a so-called two-sheet DT).
R materials) so-called single support materials (also referred to as monosheet materials) which can be formed or contain at least one photographic silver halide emulsion layer integrally with an image-receiving layer in water-permeable relationship therewith In the image receiving layer. D
The latter mono-sheet type is preferred for the production of offset printing plates by the TR method. For example, GB 1 246 661 consists of a sheet material comprising an outer hydrophilic colloid layer on the side where the silver image coming from the underlying exposed silver halide layer is enriched by the silver complex diffusion transfer reversal method. A method for producing a lithographic printing plate is described. The silver image formed on the surface is suitable for printing an image by a lithographic printing method using a wetting liquid.

[0005] Commercially available lithographic printing plate precursors of the latter type typically comprise on a flexible support such as polyester or paper, a base layer acting as an antihalation layer, a silver halide emulsion layer, and A surface layer containing physical development nuclei on which a silver image is formed is contained in this order.

Alternatively, a lithographic printing plate prepared by a silver salt diffusion transfer treatment is prepared by forming a receptor layer containing physical development nuclei and a silver halide emulsion layer on a hydrophilic support such as an aluminum support (for example, see EP-A410500). It can be obtained by providing in order. Following exposure and development,
The plate is washed with water or an aqueous liquid to remove the silver halide emulsion layer and any other layers above the receiving layer, exposing the silver image formed in the receiving layer.

The lithographic printing plate precursor (also referred to as an image forming material) described above can be exposed by a camera.
Or they can be exposed by scanning exposure, for example laser or LED exposure. The latter offers the advantage that the production of the printing plate is simplified by the fact that the paste-up to be used for the exposure of the imaging element can be completely made on a computer. This paste-up made on this computer is then
It is transferred to an image setter, for example equipped with a laser, which undertakes exposure of the imaging material, for example.

Lithographic printing plates obtained by the silver salt diffusion transfer method, and particularly those having a flexible support, generally use a photosensitive polymer composition or a diazo composition as a photosensitive coating for making a printing plate. The printing durability is limited as compared with the aluminum-based printing plate. Nevertheless, lithographic printing plates based on flexible supports offer the advantage that they are less expensive than printing plates based on aluminum supports. DTR plates with an aluminum support offer the advantage of high sensitivity over a large spectral range.

Accordingly, there is a continuing need to improve the printing durability of silver salt diffusion transfer plates. A possible improvement in print durability is preferably not an increase in the number of copies that must be discarded at the start of the printing process, for example as a result of poor ink acceptance or ink acceptance in non-image areas.

[0010] EP-A 546 598 teaches the use of physical development nuclei having an average diameter of less than 6 nm to reduce ink receptivity in the non-printed areas,
The relative number of nuclei having a diameter greater than 4.5 nm is less than 15% of the total number of nuclei in the image receiving layer.

US Pat. No. 4,160,670 describes specific hydrophilic copolymers for improving the ink repellency of background areas. Among the numerous copolymers, mention may be made of acrylamide and copolymers of comonomers having an affinity for physical development nuclei such as pyridine and imidazole.

DE-A 2 165 358 describes the use of high molecular weight compounds in the image-receiving layer, among which are copolymers of acrylamide and N-vinylimidazole.

US Pat. No. 5,236,802 discloses that the presence of polyacrylamide or a copolymer of acrylamide in the physical development nucleus layer or adjacent layers improves ink receptivity in the image area and further improves ink repellency in the background area. It is stated that it does.

[0014] US Pat. No. 2,698,237 describes a DTR image-receiving element comprising an image-receiving layer having metal sulfide nuclei precipitated in an aqueous silicon dioxide dispersion. The nucleus is taught to exhibit high activity. Further, a hydrophilic organic polymer binder in a layer containing physical development nuclei of a monosheet DTR material suitable for producing a lithographic printing plate is, for example, U
S-P3728114; 4160670; 460696
5; 4510228; 4743525; 487919
3: 5153097; 51008871 and 504135
4.

SUMMARY OF THE INVENTION It is an object of the present invention to improve the lithographic performance of a lithographic printing plate based on DTR, in particular the ink receptivity of the printing area, the ink repellency of the background (reducing dirt and toning) and printing. The purpose is to improve properties such as durability.

Further objects of the present invention will become clear from the description hereinafter.

The object of the present invention can be achieved by producing physical development nuclei containing heavy metal sulfides contained in a receiving layer of an imaging element capable of making a lithographic printing plate by a silver salt diffusion transfer process, The physical development nucleus comprises: (1) precipitating the heavy metal sulfide by bringing the water-soluble heavy metal compound into a reactive association state with the water-soluble sulfide in an aqueous liquid; Comprising the step of dispersing in the presence of a hydrophilic polymer, wherein the hydrophilic polymer is made by a method containing a heterocyclic group,
The heterocyclic group is present in a repeating unit of the hydrophilic polymer, and the repeating unit is contained in the polymer in an amount of 0.1 mol% to 5 mol%.

The present invention further provides the use of a physical development nucleus made as described above in the manufacture of an imaging element capable of making a lithographic printing plate by a silver salt diffusion transfer process.

The present invention further provides an image-wise exposing of an image-forming material comprising a silver halide emulsion layer and an image-receiving layer containing physical development nuclei prepared by the method described above on a support, and exposing according to the image thus obtained. The present invention provides a method for producing a lithographic printing plate by a silver salt diffusion transfer method, which comprises developing the obtained image forming material in the presence of a silver halide solvent and a developing agent.

DETAILED DESCRIPTION OF THE INVENTION According to the method of the present invention for producing physical development nuclei containing heavy metal sulfides, a water-soluble heavy metal compound and a water-soluble sulfide are brought into a reactive association state in an aqueous liquid. Heavy metals suitable for use in connection with the present invention include, for example, Pd, Ag, Ni, Co, and the like, or combinations thereof. Particularly preferred is Pd. Suitable water-soluble Pd compounds include, for example, (NH ₄ ) ₂ PdCl ₄ . Sodium and / or potassium sulphides are advantageously used as water-soluble sulphides.

According to the present invention, the water-soluble heavy metal compound and the water-soluble sulfide are reacted with each other in the presence of a hydrophilic polymer containing a heterocyclic group to precipitate the corresponding heavy metal sulfide. This allows the hydrophilic polymer to act as a dispersant for heavy metal sulfides.

The heterocyclic group is present in the repeating unit of the hydrophilic polymer, and the repeating unit is contained in the hydrophilic polymer in an amount of 0.1 mol% to
It is contained in an amount of 5 mol%, preferably 0.5 mol% to 1.5 mol%. The optimum amount depends on the particular structure of the hydrophilic polymer.

Hydrophilic polymers suitable for use in connection with the present invention include those having a water-solubilizing group such as an amide group, a carboxylic acid group, a hydroxy group, a sulfonic acid group, a phosphonic acid group, and the like. It is a copolymer of a monomer and a second monomer having a heterocyclic group. In addition to these two monomers, the hydrophilic polymer according to the invention can further comprise additional monomers.

Specific examples of heterocyclic groups contained in the second monomer include, for example, imidazole, imidazoline, pyrazole, thiazolidine, thiazolidone, thiazolone, indazole, pyridine, thiazine, benzotriazole, tetrazole and the like. .

According to a particularly preferred embodiment in the context of the present invention, the hydrophilic polymer is a copolymer of (meth) acrylamide and a vinyl monomer having one or more heterocyclic groups. Such vinyl monomers include, for example, vinyl imidazole, vinyl pyridine, vinyl piperidine, vinyl imidazoline, vinyl quinoline, and the like. Additional vinyl monomers may be present in such copolymers. Examples of such additional vinyl monomers include vinyl acetate, vinyl butyral, vinyl chloride, vinylidene chloride, vinyl (meth) acrylate, styrene, and vinyl monomers such as derivatives, vinyl ethers, and the like.
The copolymer can be a random copolymer, an alternating copolymer or a block copolymer.

The polymerization degree (number average) of the polymer used according to the present invention is preferably from 20 to 1,000. The average degree of polymerization according to the invention is determined by means of GPC, in which case a solution of 0.05 mol / l of sodium chloride in water is used as eluent, polyethylene glycol and T
An SK column 3000PW was used. A polymerization degree that is too low results in dissolution of the polymer from the plate during processing, while a polymerization degree that is too high provides coating difficulties.

The hydrophilic polymer is preferably 0.2% by weight
~ 2 wt%, more preferably 0.3 wt% to 1 wt% are present or added during the precipitation of heavy metal sulfides.
Additional hydrophilic polymer can be added following completion of the precipitation. Preferably, the total amount of the hydrophilic polymer is present from the beginning of the precipitation, but the hydrophilic polymer can also be added gradually during the precipitation or at intervals during the precipitation.

According to the manufacturing method in the context of the present invention,
A single jet, double jet or multiple jet method can be used to add the reactants to one another. According to the single jet method, the water-soluble sulfide is either added to the water-soluble heavy metal compound or vice versa. In that case, the hydrophilic polymer is preferably present in the solution of the reaction component to which the solution of the other reaction component is added. Alternatively, the hydrophilic polymer can be added to one with the other of the reactants. Furthermore, a part of the total amount of the hydrophilic polymer used during the production can be present in the solution of the reaction components to which the other reaction components are added, and a part can be added with the other reaction components.

According to a highly preferred embodiment, the physical development nuclei are prepared by a double jet method, wherein both reactants (water-soluble sulfide and water-soluble heavy metal compound) are added to a third solution. This third solution preferably contains a hydrophilic polymer. At least some or even all of the hydrophilic polymer can be added via one or both of the solutions containing the reactants.

According to a third embodiment for the precipitation of heavy metal sulfides, a triple jet can be used to add the components together. For example, the binary and the hydrophilic polymer can be added by separate jets.

According to either the double or multiple jet method described above, a portion of one of the reactants (eg, a water-soluble sulfide) can be added to the solution to which the reactants are added by a jet. Furthermore, the rate of addition of one or more of the reaction components may be varied during the course of the precipitation, and may be kept constant or increased. In particular, it is desirable to add a portion of the hydrophilic polymer at the beginning, and then at one or more intervals during the course of the precipitation (eg, at the end).

In connection with obtaining the best lithographic printing plate performance, producing heavy metal sulfides using an excess of sulfides relative to the stoichiometric proportion of sulfides in the heavy metal sulfides to be precipitated is More desirable. Thus, for example, in precipitating a 1: 1 theoretical amount of palladium sulfide containing sulfur ions, it is preferred to add at least 2 moles of sulfide per mole of palladium.

During the precipitation, various other components can be present, in particular other hydrophilic polymers which are not within the scope of the invention, such as polyvinyl alcohol and / or poly (meth) acrylic acid.

Alternatively or additionally, a hydrophilic polymer not according to the invention can be added after the precipitation has been completed. In particular, poly (meth) acrylic acid or poly (meth) acrylamide can be added. Furthermore, an additional amount of the hydrophilic polymer according to the invention can be added following precipitation of the physical development nuclei.

In addition, inorganic colloidal substances can be added during the precipitation of the physical development nuclei, but preferably after the precipitation. Suitable inorganic colloid materials include, for example, colloidal silica or colloidal clay.

Clays are essentially hydrous aluminum silicates in which alkali metals or alkaline earth metals are present as the main constituent. Also, in some clay minerals, magnesium or iron or both replace all or part of the aluminum. The final chemical constituents of clay minerals vary not only in quantity, but also in the way they are bound or present in the various clay minerals. Natural clays are well known, but synthetic clays can also be made in the lab, allowing a great deal of freedom to provide tailor-made and reproducible clay products for use in different applications.

Smectite clays including laponite, hectorite and bentonite from natural clays are well known and can be used in the present invention. For smectite clay, some substitution may occur in both the octahedral and tetrahedral layers of the crystal lattice, resulting in a small number of interlayer cations. Smectite clays absorb water and organic liquids between the composite layers and form a group of "swellable" clays with significant cation exchange capacity. Synthetic and chemically pure clays have been produced from these smectite clays.
They are particularly suitable for use in the present invention.

The clay used in accordance with the present invention is preferably a smectic clay, more preferably a synthetic smectic clay, and most preferably a synthetic laponite. Preferred synthetic laponite clays for the present invention include, for example, those of London.
LAPONITE, a trademark product of LAPORTE INDUSTRIES Limited
There are RD, LAPONITE RDS and LAPONITE JS.

Synthetic clay and its manufacturing method are described in EP Patent 16
1411B1.

In the context of the present invention, physical development nuclei containing heavy metal sulfides are preferably such that they have an average diameter of less than 6 nm and the number of nuclei having a diameter of more than 4.5 nm is less than the total number of nuclei. Produced to be less than 15%.
Although the size of the nucleus is indicated by the diameter, this does not mean that the nucleus is necessarily spherical. By diameter is meant the diameter of a sphere having the same volume so that the size of various shapes of nuclei can be characterized with the same parameters.

According to a highly preferred embodiment in the context of the present invention, the imaging element comprises, on a support, a silver halide emulsion layer and a receiving layer containing physical development nuclei prepared according to the invention as described above. Are contained in this order.

Photographic silver halide emulsions include, for example, Parry's
Paul Montel 1967, P. Glafkides, Chimi
e et Physique Photographique; The F in London
ocal Press 1966, GF Duffin, Photo
graphic Emulsion Chemistry; and The London
It can be prepared from soluble silver salts and soluble halides by different methods as described in Making and Coating Photographic Emulsion by Focal Press, 1966, VL Zelikman et al.

The photographic silver halide emulsions used according to the present invention can be prepared by mixing the halide and silver solutions under partially or completely controlled conditions of temperature, concentration, order of addition, and rate of addition. . Silver halide can be precipitated by the single jet method or the double jet method.

The silver halide grains of the photographic emulsions used according to the invention can have a regular crystalline form, such as a cubic or octahedral form, or they can have a transition form. They can also have an irregular crystalline form, such as a spherical or tabular form, or else have a composite crystalline form comprising a mixture of said ordered and irregular crystalline forms.

According to the invention, the emulsion preferably consists mainly of silver chloride, preferably at least 7 silver chloride.
0 mol%, more preferably at least 80 mol%, most preferably at least 95 mol%. If present, the remainder of the silver halide can be silver bromide, optionally silver iodide in an amount up to 3 mol%, preferably up to 1.5 mol%. According to a particularly preferred embodiment in the context of the present invention, 2 mol%
A silver chloroiodide emulsion having the following silver iodide is used. Silver chloroiodide emulsions first precipitate silver nitrate with a water-soluble chloride, such as sodium chloride, and then at the end of the precipitation, typically during the last 10% of the water-soluble iodide, such as potassium iodide. It can be conveniently prepared by precipitation, thus yielding silver halide grains having silver iodide in the shell of the silver halide grains.

The average grain size of the silver halide grains is 0.10
０．７0.70 μm, preferably 0.25 to 0.45 μm.

The size distribution of the silver halide grains of the photographic emulsion to be used according to the invention can be homodisperse or heterodisperse. A homodisperse size distribution is obtained when 95% of the particles have a size that does not deviate more than 30% from the average size.

Preferably during the precipitation stage iridium and / or rhodium containing compounds or a mixture of both are added.
The concentration of these added compounds, AgNO ₃ 1 10 ^-8 to 10 ^-3 mole for mole, preferably AgNO ₃
The range is from 10 ^-7 to 10 ^-6 mole per mole. This means that a small amount of iridium and / or
Or the incorporation of rhodium, so-called iridium and / or rhodium dopants. As is known to those skilled in the art, many scientific and patent literatures describe the addition of iridium or rhodium containing compounds or compounds containing other elements of Group VIII of the Periodic Table during emulsion preparation.

The emulsions can be chemically sensitized during the chemical ripening stage by adding sulfur containing compounds such as allyl isothiocyanate, allyl thiourea, and sodium thiosulfate. A reducing agent such as BE-P493634;
And the derivatives of polyamines such as diethylenetriamine or aminomethanesulfonic acid can also be used as chemical sensitizers. Other suitable chemical sensitizers include noble metals and noble metal compounds such as gold, platinum, palladium, iridium, ruthenium and rhodium. This chemical sensitization method is based on Z. Wiss. Photogr. Ph.
otophys. Photochem. (1951), 46, 65-7
It is described in R. KOSLOWSKY's paper on page 2.

The emulsion of the DTR material can be spectrally sensitized according to the spectral emission of the exposure source for which the DTR material is designed.

Suitable sensitizing dyes for the visible spectral band include John Wiley & Sons, 1964
FM in Cyanine Dyes and Related Compounds
Includes methine dyes such as those described by Hamer. Dyes that can be used for this include cyanine dyes, merocyanine dyes, complex cyanine dyes, complex merocyanine dyes, isopolar cyanine dyes, hemicyanine dyes, styryl dyes and hemioxonol dyes. Particularly useful dyes are those belonging to the cyanine dyes, merocyanine dyes and complex merocyanine dyes.

The silver halide emulsions can be prepared with customary stabilizers, for example isopolar or salt compounds of mercury with aromatic or heterocyclic rings, for example mercaptotriazole, simple mercury salts,
Can contain sulfonium mercury double salts and other mercury compounds. Other suitable stabilizers are azaindenes, preferably tetra or pentaazaindenes, especially those substituted with hydroxy or amino groups. Compounds of this type are described in Z. Wiss. Photogr. Photophys. Photochem.
Published in two years, 47, p. 2-27 by BIRR. Other suitable stabilizers include heterocyclic mercapto compounds, for example heterocycles substituted with bulky substituents such as alkyl groups having at least 5 carbon atoms or aryl groups having at least 8 carbon atoms. Formula mercapto compounds, such as 1-n-heptyl-5-mercaptotetrazole or 3-mercapto-5-n-heptyl-
There are oxazole, phenylmercaptotetrazole, quaternary benzothiazole derivatives, and benzotriazole. Preferred compounds are mercapto-substituted pyrimidine derivatives as described in US Pat. No. 3,692,527.

The silver halide emulsion can contain a pH controlling component. Preferably, the emulsion layer is coated at a pH value below the isoelectric point of gelatin to improve the stability properties of the coating layer. Other ingredients such as antifoggants, development accelerators, wetting agents, and hardeners for gelatin may be present. The silver halide emulsion layers can contain light screening dyes that absorb scattered light and thus promote image sharpness. Suitable light absorbing dyes are, for example, US-P 4,092,168, US-P4
311787 and DE-P 2 453 217.

Further details on the composition, preparation and coating of silver halide emulsions can be found, for example, in Product Licensing Ind.
ex, Volume 92, December 1971, publication 9232
On pages 107-109.

Between the support and the silver halide emulsion layer,
It is preferred to provide a base layer containing an antihalation dye, such as a light absorbing dye, which absorbs the light used for imagewise exposure of the imaging element. Alternatively, micronized carbon black can be used as the antihalation substance. On the other hand, in order to obtain an increase in sensitivity, a light-reflecting pigment such as titanium dioxide can be present in the base layer. In addition, this layer can contain hardening agents, matting agents, such as silica particles, and wetting agents. Suitable matting agents preferably have a number average diameter of 2 to 10 μm, more preferably 2 to 5 μm. Matting agents are generally present in the imaging element at 0.1
used in a total amount of ^{g / m 2 ~2.5g / m 2} . These matting agents and / or light-reflecting pigments can also be present in the silver halide emulsion layer, but most preferably at least 80% by weight can be contained in the silver halide emulsion layer. However, all of the matting agent can be included in the silver halide emulsion layer, with the base layer being substantially free of matting agent. When the entire matting agent is contained in the silver halide emulsion layer, it is preferable to add a non-water-swellable latex to the base layer. Examples of the non-water-swellable latex include a copolymer of styrene and butadiene, polyethyl acrylate, polymethyl methacrylate, a copolymer of acrylate, and a copolymer of methacrylate.
As a further alternative, the light reflecting pigment can be present in another layer provided between the antihalation layer and the photosensitive silver halide emulsion layer. Like the emulsion layer, the base layer is preferably coated at a pH below the isoelectric point of the gelatin in the base layer.

In a preferred embodiment in the context of the present invention, a backing layer is provided on the non-photosensitive side of the support. This layer, which can act as an anti-curl layer, can contain, for example, matting agents such as silica particles, lubricants, antistatic agents, light absorbing dyes, opacifiers such as titanium oxide and customary components such as hardeners and wetting agents. The backing layer can consist of a single layer or a multilayer pack, for example a double layer pack.

The hydrophilic layer usually contains gelatin as a hydrophilic colloid binder. Mixtures of different gelatins with different viscosities can be used to adjust the rheological properties of the layers. However, instead of or with gelatin, one or more other natural and / or synthetic hydrophilic colloids, such as albumin, casein, zein, polyvinyl alcohol, alginic acid or its salts, cellulose derivatives such as carboxymethylcellulose, modified gelatin such as phthaloyl Gelatin or the like can be used.

The hydrophilic layer of the photographic material, especially when the binder used is gelatin, is a suitable hardener such as an epoxy type, an ethyleneimine type or a vinylsulfone type such as 1,3-vinylsulfonyl- 2-propanol, chromium salts such as chromium acetate and chromium alum, aldehydes such as formaldehyde, glyoxal, and glutaraldehyde, N-methylol compounds such as dimethylolurea and methyloldimethylhydantoin, dioxane derivatives such as 2,3-dihydroxydioxane, active vinyl compounds such as 1,3,5-triacryloyl-hexahydro-s-triazine, an active halogen compound such as 2,4-dichloro-6-hydroxy-
Curable with s-triazines, and mucohalic acids such as mucochloric and mucophenoxycyclo acids. These curing agents can be used alone or in combination. The binders can also be hardened with fast-reacting hardeners, for example carbamoylpyridinium salts of the type described in U.S. Pat. No. 4,063,952.

The imaging element used according to the present invention can further contain various surfactants in the photographic emulsion layer or in at least one other hydrophilic colloid layer. Suitable surfactants include saponins, alkylene oxides such as polyethylene glycol, polyethylene glycol / propylene glycol condensation products, polyethylene glycol alkyl ethers or polyethylene glycol alkyl aryl ethers, polyethylene glycol esters, polyethylene glycol sorbitan esters, polyalkylene glycol alkylamines Or an alkyl amide,
Nonionic surfactants such as silicone polyethylene oxide adducts, glycidol derivatives, fatty acid esters of polyhydric alcohols and alkyl esters of saccharides; anions containing acid groups such as carboxy, sulfo, phospho, sulfate or phosphate groups Surfactants; amphoteric surfactants such as amino acids, aminoalkyl sulfonic acids, aminoalkyl sulfates or phosphates, alkyl betaines and amine-N-oxides; and alkylamine salts, aliphatic, aromatic or heterocyclic quaternary ammonium salts And a cationic surfactant such as an aliphatic or heterocyclic ring-containing phosphonium or sulfonium salt. Preferably, a compound containing a perfluorinated alkyl group is used. Such surfactants can be used for various purposes, for example as coating aids, as antistatic agents, as compounds for improving lubricity, as compounds for facilitating dispersion emulsification, and as compounds for preventing or reducing adhesion.

The imaging element of the present invention may further comprise various other additives such as compounds which improve the dimensional stability of the photographic material,
V absorbers, spacing agents, and plasticizers can be included.

Additives suitable for improving the dimensional stability of the photographic material include, for example, dispersions of water-soluble or poorly soluble synthetic polymers, such as alkyl (meth) acrylates, alkoxy (meth) acrylates, glycidyl ( (Meth) acrylate, (meth) acrylamide, vinyl ester, acrylonitrile, polymer of olefin and styrene, or those described above and acrylic acid, methacrylic acid, α, β-unsaturated dicarboxylic acid, hydroxyalkyl (meth) acrylate, sulfoalkyl There is a dispersion of a copolymer of (meth) acrylate and styrene sulfonic acid.

Suitable supports of the imaging element in the context of the present invention can be either opaque or transparent;
The latter offers the advantage of exposure through the support, so that the exposure can take place in a camera without a reflector. Particular examples of supports are polyethylene-coated paper, polypropylene-coated paper, opaque or transparent polyester films, especially polyethylene terephthalate films. Aluminum supports or other hydrophilic supports can also be used as described in the introduction herein. In that case, the image receiving layer is located between the support and the silver halide emulsion layer.

According to a preferred embodiment in connection with the [0063] present invention, it has a thickness of 0.1Mm～0.35Mm, at least 4300N / mm ^2, more preferably at least 4500N / mm ² Young's modulus (E- (Modulus). Young's modulus, also referred to as E-modulus in the context of the present invention, can be measured by Method A according to ANSI-D882-91.

The polyester film support is preferably coated with a layer which improves the adhesion of the hydrophilic layer.

A particularly preferred adhesion improving layer comprises a copolymer containing a water-soluble monomer and a water-insoluble monomer in a molar ratio of 1:99 to 20:80. Preferably, the water-soluble monomer is a monomer having one or more carboxylic acid groups. Examples of particularly preferred copolymers for use in the adhesion improving layer include:
It is a polymer containing 1 to 10% by weight, more preferably 1 to 5% by weight of itaconic acid. Suitable polymers containing itaconic acid include, for example, copolymers of itaconic acid and vinylidene chloride, copolymers of itaconic acid, vinylidene chloride and vinyl acetate, copolymers of itaconic acid, vinylidene chloride and methyl (meth) acrylate. And copolymers of itaconic acid and vinyl chloride, copolymers of itaconic acid, vinyl chloride, vinylidene chloride and methyl (meth) acrylate. In copolymers of itaconic acid, vinylidene chloride and optionally methyl (meth) acrylate, the amount of itaconic acid is 1% to 5%, the amount of vinylidene chloride is 70% to 95%, and methyl (meth) The amount of acrylate is between 0% and 15%. Preferably, the adhesion improving layer does not contain gelatin.

On top of this adhesion-improving layer may be provided an intermediate layer containing microparticles having an average diameter of less than 50 nm, preferably containing colloidal silica and gelatin in a weight ratio of 1: 2 to 2: 1.

According to a preferred method of the present invention, an image-forming material containing, in this order, a silver halide emulsion layer and a receiving layer containing physical development nuclei prepared according to the present invention on a support is prepared by the DTR method. And then developed. The DTR monosheet imaging material in the context of the present invention may be exposed to light in a device according to its particular use, for example with a conventional plate making camera containing a conventional light source or with a high intensity short exposure such as a laser containing device. it can.

The alkaline processing liquid used to develop the image-forming material preferably contains at least a part of a silver halide solvent. Preferably, the silver halide solvent is 0.1.
It is used in an amount of from 01% to 10% by weight, more preferably from 0.05% to 8% by weight. Silver halide solvents suitable for use in connection with the present invention include, for example, 2-
There are mercaptobenzoic acids, cyclic imides, oxazolidones, thiocyanates and thiosulfates. Still other preferred silver halide solvents for use in connection with the present invention are described in EP-A 554584. It should be noted that the effect of the present invention is particularly remarkable when a combination of an alkanolamine and a meso-ion thiolate compound, preferably a meso-ion triazolium thiolate, is used as a silver halide solvent.

According to the invention, the alkaline processing liquid preferably also contains a hydrophobizing agent in order to improve the hydrophobicity of the silver image obtained in the image-receiving surface layer. The hydrophobizing agent used in connection with the present invention can react with silver or silver ions,
Compounds that are hydrophobic, ie, insoluble or only slightly soluble in water. In general, these compounds contain a mercapto or thiolate group and one or more hydrophobic substituents, for example an alkyl group containing at least 3 carbon atoms. Examples of hydrophobizing agents for use according to the invention include, for example, US Pat. No. 3,776,728, US Pat.
563410 and EP-A554584.

The alkaline processing liquid can also contain the developing agents used according to the invention. In this case, the alkaline processing liquid is called a developer. On the other hand, some or all of the developing agent can be present in one or more layers of the imaging element.
When all of the developing agent is contained in the imaging element, the alkaline processing liquid is referred to as an activator or liquid.

The silver halide developing agent for use in accordance with the present invention is preferably a 1-phenyl-3-pyrazolidone developing agent and / or a p-dihydroxybenzene based developing agent in combination with an auxiliary developing agent which is p-monomethylaminophenol. , For example, hydroquinone, methylhydroquinone or chlorohydroquinone. Particularly useful auxiliary developing agents include those of the phenidone type, such as 1-phenyl-3-pyrazolidone, 1-phenyl-4-monomethyl-3-pyrazolidone, and 1-phenyl-4,4-dimethyl-3-pyrazolidone. is there.
However, other developing agents can be used.

The alkaline processing liquid preferably also contains a preservative having antioxidant activity, for example, sulfite ions provided by sodium or potassium sulfite. For example, the aqueous alkaline solution contains sodium sulfite in an amount ranging from 0.15 to 1.0 mol / l. In addition, thickeners such as hydroxyethylcellulose and carboxymethylcellulose, antifoggants such as potassium bromide, potassium iodide and benzotriazole (known to improve print durability), calcium sequestering compounds, sludge prevention Agents and hardeners, including latent hardeners, can be present.

The development is accelerated by various compounds for the alkaline processing solution and / or one or more layers of the photographic material, preferably for example US Pat. No. 3,038,805, US Pat.
8075, US-P4292400, US-P4975
This can be achieved with the aid of a polyalkylene derivative having a molecular weight of at least 400 as described in 354.

Following development in an alkaline processing solution, the surface of the printing plate is preferably neutralized using a neutralizing solution.

The neutralizing solution generally has a pH of 5-7. The neutralization solution preferably contains a buffer such as a phosphate buffer, a citrate buffer or a mixture thereof. The neutralizing solution may further comprise a bactericide, for example phenol, thymol, turpi as described in EP 0150517.
nal) or 5-bromo-5-tetro-1,3-dioxane. The liquid is also a substance which affects the hydrophobic / hydrophilic balance of the printing plate obtained after processing of the DTR material,
For example, silica can be contained. Further, the neutralizing solution may contain a wetting agent, preferably a compound containing a perfluorinated alkyl group.

The present invention is illustrated by the following examples, but the invention is not limited thereto. All parts are by weight unless otherwise specified.

EXAMPLES Preparation of a silver halide emulsion coating solution A silver chlorobromide emulsion consisting of 98.2 mol% of silver chloride and 1.8 mol% of silver bromide was prepared by the double jet precipitation method. The average silver halide grain size was 0.38 μm (diameter of a sphere having the same average volume) and contained rhodium ions as internal dopant. The emulsion was stabilized with 1-phenyl-5-mercaptotetrazole and sensitized orthochromatically.

[0078] have a thickness 175μm preparation of image forming material, a six polyethylene terephthalate film support provided with adhesive improving layer, the gelatin and 0.4 g / m ² in an amount of 0.4 g / m ^2, respectively Coated with a layer containing colloidal silica with an average particle diameter of 7 nm. The adhesion improving layer was made of itaconic acid (2
%), A copolymer of vinylidene chloride (88%) and methyl methacrylate (10%).

The coated polyethylene terephthalate film support was coated with a silver halide emulsion prepared as described above together with an antihalation layer (which is below the silver halide emulsion layer). Was 2.7 g / m ² and 1.34 g / m ² for the silver halide emulsion layer. AgNO
The amount of silver halide indicated as ₃ is 1.25 g / m ²
And the emulsion layer further contained 120 mg / m ² of formaldehyde as a developing agent and a curing agent. The antihalation layer further contained a silica matting agent having an average particle size (weight average diameter) of 3.4 μm and carbon black as antihalation means. The material thus obtained was kept at 57 ° C. at a relative humidity of 34% a day.

The physical development nucleus (PdS) was prepared by adding a soluble palladium salt (A) and a sodium sulfide solution (B) to 400 d
Prepared by double jet precipitation adding at a constant rate to the third solution (C) containing sodium sulfide with stirring at pm for 4 minutes. Following precipitation, the resulting precipitated nuclei are
Dialysis was performed to a conductivity of mS.

The method described above was applied using different solutions A, B and C to change the precipitation conditions of physical development nuclei. The following solutions were made:

[0082] PVA is a 1% solution of polyvinyl alcohol in water. PAA is a 1% solution of polyacrylamide in water. PAI-1 is a 1% solution of a copolymer of acrylamide (99 mol%) and vinyl imidazole (1 mol%). PAI-2 is a 1% solution of a copolymer of acrylamide (98 mol%) and vinyl imidazole (2 mol%).

[0083]

[0084]

The five precipitates were combined with solutions Ai, Bi and Ci
(In this case, i corresponds to the solution number in each of the above tables) according to the method described above. As a result, five kinds of coating solutions for coating physical development nuclei were obtained. Numbers 1 to 5 corresponding to the numbers of the solutions A to C from which the solutions A to C were obtained were given. Further, the coating solution 2 contains P corresponding to 0.7%.
The amount of AA was added to obtain another coating solution (coating solution 2b).

To each of these coating solutions, formaldehyde and hydroquinone were added such that their amounts in the final image receiving layer were 30 mg / m ² and 0.4 g / m ² , respectively.

The resulting coating solution was used to make six imaging materials by coating the solution on the six materials made as described above. Subsequently, 34% of the image forming material
At 57 ° C. for 1 day.

The following alkaline treatment solution was prepared: sodium hydroxide 30 g methylhydroquinone 2 g anhydrous sodium sulfite 35 g amino-ethylaminoethanol 45 ml compound A (see below) 0.8 g EDTA / 4Na 1 g 3-mercapto-5-n-heptyl Oxadiazole 0.35 g Make up to 1 l with water. EDTA · 4Na is a sodium salt of ethylenediaminetetraacetic acid.

[0089]

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The following neutralized solution was prepared: 10 g of citric acid 35 g of sodium citrate 5 g of anhydrous sodium sulfite 5 g of phenol 50 mg The mixture was made up to 1 l with water.

The following humidifying solution was prepared: water 880 ml citric acid 6 g boric acid 8.4 g anhydrous sodium sulfite 25 g ethylene glycol 100 g colloidal silica 28 g

The image-forming material described above was imagewise exposed, treated with the above-mentioned alkaline processing solution at 30 ° C., subsequently neutralized at 25 ° C. with the above-mentioned neutralizing solution and dried.

The printing plate thus prepared was mounted on an offset printing machine (two-color GTO printing machine). The moisturizing solution described above was used during printing. The printing properties were evaluated by the ink receptivity of the starting print areas and the unwanted ink receptivity (toning) in the non-print areas as follows:

The ink receptivity is the number of copies required to obtain a stable density of the printed part. 1: <10 copies required 2: 10-15 copies required 3:> 15 copies required

Toning is the number of copies required to obtain a clean print without ink reception in the non-print area. 1: 100-150 copies 2: 151-250 copies 3: 251-300 copies 4:> 300 copies

The results obtained are as follows:

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ronii de Clark Mozèle, Belgium, Septetriat 27 Inside Agfa Géberd na Ml ベ ン ze Bennoutchap (72) Inventor René de Keizer, Mozère, Belgium, Septestate 27 Inside Agfa Gewerth Namurose Bennoutchap (56) References JP-A-1-262541 (JP, A) JP-A-49-16507 (JP, A) (58) Fields studied (Int .Cl. ⁶ , DB name) G03C 8/28 G03F 7/07

Claims (8)

(57) [Claims] 1. A lithographic printing plate is produced by a silver salt diffusion transfer method.
A method for producing an image forming material, wherein the image forming material is
Physical expression containing heavy metal sulfide produced by the following process
Preparation containing Zokaku: (1) Step Ru precipitate the heavy metal sulphide by bringing a water-soluble heavy metal compound in reactive association state with a water-soluble sulfide in aqueous solution; and, the precipitate (2) A step of dispersing the heavy metal sulfide in the presence of a hydrophilic polymer (the hydrophilic polymer
Contains a heterocyclic group), in the heterocyclic group is present in the repeating unit of the hydrophilic polymer, the repeating units are the polymer to 0.1 mol% to 5 mol% A method characterized in that it is contained in an amount. 2. The method of claim 1, wherein said water-soluble heavy metal compound is a water-soluble palladium compound and said water-soluble sulfide is potassium or sodium sulfide. 3. The hydrophilic polymer comprises: (i) a first monomer having a water-solubilizing group selected from the group consisting of an amide group, a hydroxy group, a carboxylic acid group and a sulfonic acid group; The method of claim 1 or 2, wherein the copolymer is a copolymer of a second monomer having a cyclic group and (iii) an optional additional monomer. 4. The method of claim 3, wherein said first monomer is acrylamide or methacrylamide. 5. The method according to claim 3, wherein the second monomer is vinylimidazole or vinylpyridine. 6. The polymer according to claim 6, wherein the heterocyclic group is present in a repeating unit of the hydrophilic polymer, and the repeating unit is present in the polymer in an amount of 0.1 to 0.2.
The method according to any one of claims 1 to 5, which is contained in an amount of 1 mol% to 1.5 mol%. 7. The method according to claim 1, wherein the hydrophilic polymer is contained in an amount of 0.3% by weight to 1% by weight.
7. The composition according to claim 1, wherein said compound is present in an amount of 5% by weight.
The method according to any one of the preceding claims. 8. The method according to claim 1, wherein the sulfide is added in excess of the theoretical amount of sulfide in the heavy metal sulfide.
The method according to any one of claims 1 to 7.