JPH11133613A - Photothermographic material and production of lithographic printing plate using that - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a storage material to produce a lithographic printing plate of high sensitivity by a dry process in a simple method. SOLUTION: This photothermographic material contains an element which can be addressed by light and can be thermally developed on a support. This element contains an org. heavy metal salt which is substantially non- photosensitive, a photosensitive silver halide which is catalytically associated with the substantially non-photosensitive org. heavy metal salt, and an agent reducing the substantially non-photosensitive org. heavy metal salt, and a binder. Further, the photothermographic material has an outermost layer having two phases on the same surface of the support where the thermally developable element exists. At least one phase of the two phases is a dispersion phase of thermoplastic particles. The two phases show different affinities from each other for one printing liquid selected from a group of ink and adhesive liquids to the ink.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[1. FIELD OF THE INVENTION The present invention relates to photothermographic materials for making lithographic printing plates. The invention further relates to a method for making a printing plate from said photothermographic material.

[0002]

[2. BACKGROUND OF THE INVENTION Lithographic printing is a method of printing from a specially prepared surface, some areas of which are receptive to ink (oleophilic areas), while others are not ink receptive (oleophobic areas). The lipophilic area forms the printing area, while the oleophobic area forms the background area.

[0003] Two basic types of lithographic printing plates are known. According to a first type, the so-called wet printing plate, both water or an aqueous dampening solution and ink are applied to the surface of the plate containing hydrophilic and hydrophobic areas. The hydrophilic areas are impregnated with water or dampening liquid and thereby rendered oleophobic, whereas the hydrophobic areas receive ink. A second type of lithographic printing plate works without the use of a dampening solution and is called a driographic printing plate.
This type of printing plate contains highly ink repellent areas and oleophilic areas. Generally, the highly ink repellent areas are formed by a silicon layer.

[0004] Printing plates can be made using photographic materials that are made image-wise receptive or repellent to the ink upon exposure of the material. However, heat mode recording materials are also known for the production of printing plates, the surface of which is exposed imagewise to heating by a light source and, if necessary, subsequently imagewise receptive to the ink when developed. Can be repulsive.

US Pat. No. 3,168,864 produces an imaged lithographic master having a visually distinguishable ink receptive area corresponding to the image area of a different radiation-absorbing graphic original. A method is described wherein the steps include: subjecting the original to short-term intense radiation through a thin radiation-transmissive thermosensitive copy sheet in thermal-conductive contact therewith, wherein the copy sheet is visible. A strongly heat-absorbing lithographic printing plate having a hydrophilic surface which provides a reproduction of the image area which is strongly radiation-absorbing and which has a hydrophilic surface which becomes hydrophobic and ink-receptive when heated. Making a thermally-conductive contact and subjecting it to intense radiation for a shorter period of time, wherein said plate forms a chemically reactive and visually distinct reaction product when heated. The coat Includes ringing. A particular disadvantage of the plate is its low sensitivity and its susceptibility to register problems.

US Pat. No. 3,649,271 discloses, in addition to a continuous phase of a hydrophilic binder and a dispersed phase of thermoplastic hydrophobic particles,
It contains photosensitive silver halide and a developing agent for such halides present in the outermost layer and / or the adjacent lower layer, so that exposure and photographic development using an alkaline solution can be carried out with thermoplastic particles and heat-conductivity. Following the uniform exposure with the developed silver image, the heat generated in the silver image due to such absorption reduces the hydrophilicity of the region of the outermost layer in heat-conductive relationship therewith. A recording material is disclosed. A particular disadvantage of the plate is that it requires wet treatment, thus producing toxic waste.

[0007] US-P-3,476,937 discloses a method for recording or reproducing information which substantially separates a generally uniform layer of finely divided particles consisting essentially of a hydrophobic thermoplastic material. Subjecting the recording material in a continuous relationship to heat applied to the particle layer in a pattern according to the information, the heat at least partially agglomerating particles in regions of the layer corresponding to the pattern, thereby An amount sufficient to significantly reduce the liquid permeability of the layer in the at least partially agglomerated region, and further treating the layer to reduce the liquid permeability of the layer in a region of the layer that is not substantially reduced in permeability. Improvements are disclosed that include developing or reproducing the information by removing the particles to leave partially agglomerated regions corresponding to the thermal pattern. The patent does not disclose the presence of a substantially light-insensitive organic heavy metal salt.

[0008] Therefore, there is still a need for recording elements for the production of lithographic printing plates having high sensitivity and having only a dry processing step and producing no waste liquid.

[0009]

[3. SUMMARY OF THE INVENTION An object of the present invention is to provide a recording material for producing a lithographic printing plate having high sensitivity.

Another object of the present invention is to provide a recording material for preparing a lithographic printing plate having high sensitivity by a dry process without producing a waste liquid by a simple method.

Still another object of the present invention is to provide a method for obtaining a high-quality lithographic printing plate using the image forming material in a simple manner.

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

According to the present invention, a substantially light-insensitive organic heavy metal salt, a light-sensitive silver halide in catalytic association with a substantially light-insensitive organic heavy metal salt, a substantially light-insensitive light A photo-addressable and thermally developable element containing a reducing agent and a binder for a neutral organic heavy metal salt on a support, the same support as the photo-addressable and thermally developable element. An outermost layer having two phases on the side of the body, wherein at least one of the two phases is a photothermographic material that is a dispersed phase of thermoplastic particles, and the two phases are an ink and an adhesive fluid for the ink. A photothermographic material is provided that exhibits a different affinity for at least one printing fluid selected from the group consisting of:

According to the invention, there is also provided (a) exposing the recording material to actinic radiation image-wise or information-wise;
(B) developing the substantially light-insensitive organic heavy metal salt by exposing the recording material to a temperature of at least 65 ° C. and up to 5 ° C. below the Tg of the thermoplastic particles, thereby forming a heavy metal image; (C) exposing the outermost layer entirely using a light source that emits light having a wavelength that is absorbed by the heavy metal image, and adjusting the temperature of the outermost layer to the Tg of the thermoplastic particles;
There is also provided a method of obtaining a lithographic printing plate comprising the step of image-wise raising to a higher temperature.

[0015]

[4. DETAILED DESCRIPTION OF THE INVENTION The above recording material has a high sensitivity and gives a printing plate without a wet development method or without waste liquid,
It has been found to produce both economic and ecological benefits.

In the context of the present invention, hydrophilic polymer means that the water adheres to the polymer when coated on a support and brought into contact with a mixture of water and oil. However, in the absence of water, oil can adhere to such a layer of hydrophilic polymer. For the purposes of the present invention, a lipophilic polymer is a polymer on a support to which an oil adheres when contacted with a mixture of water and oil.

In a first group of embodiments of the present invention, the outermost layer contains an ink receptive phase and an ink and water repellent phase.

In the first embodiment of this first group of embodiments, the ink receptive phase has a hydrophilic binder as the continuous phase, preferably a hardened hydrophilic continuous binder. Suitable hydrophilic binders for use in this embodiment in connection with the present invention are water-soluble polymers or copolymers, which may be synthetic, for example polyvinyl alcohol, polymers and copolymers of (meth) acrylic acid, of (meth) acrylamide. It can be a polymer and copolymer, a polymer and copolymer of hydroxyethyl (meth) acrylate, a polymer and copolymer of vinyl methyl ether, or the like or a natural such as gelatin, a polysaccharide such as dextran, pullulan, cellulose, gum arabic, alginic acid.

It is also possible to use mixtures of the same or different types of hydrophilic binders. Particularly suitable crosslinked hydrophilic layers are
It can be obtained from a hydrophilic binder cross-linked using a cross-linking agent such as formaldehyde, glyoxal, polyisocyanate or hydrolyzed tetra-alkyl orthosilicate.

First Group of Embodiments The ink and the water-repellent phase used in the first embodiment of the first embodiment contain ink and water-repellent thermoplastic particles, preferably silicon-based polymers or perfluorinated alkyl groups. Contains polymer. Mixtures can also be used. The ratio by weight of ink and water-repellent thermoplastic particles to hydrophilic binder is 1: 5 to 5: 1.
And more preferably within the range of 1: 2 to 2: 1.

In a second embodiment of the first group of embodiments, the ink receptive phase comprises a latex of a lipophilic polymer. Examples of preferred lipophilic polymers for use in connection with this embodiment of the present invention are vinyl chloride, vinylidene chloride,
It is a copolymer or polymer such as acrylonitrile or vinylcarbazole, or a mixture thereof. Particularly preferred are copolymers and polymers of styrene or methyl methacrylate. The polymer latex can be hardened. Latex mixtures can also be used.

The inks and water-repellent phases used in the second embodiment of the first group of embodiments are also inks and water-repellent thermoplastic particles, preferably polymers based on silicon or polymers containing perfluorinated alkyl groups. It contains.
Mixtures thereof can also be used. The ratio by weight of ink and water-repellent thermoplastic particles to lipophilic polymer is in the range of 1:10 to 10: 1, more preferably 1: 5.
It is in the range of 5: 1 and particularly preferably in the range of 1: 2 to 2: 1.

These two embodiments have the advantage that they can be coated from an aqueous dispersion. In a third embodiment of the first group of embodiments, the ink receptive phase comprises a lipophilic binder as a continuous phase. Particular examples of lipophilic polymers for use in the binder in connection with this embodiment of the invention are the lipophilic polymers listed above. The lipophilic binder can be hardened and a mixture of lipophilic polymers can be used.

The lipophilic binder can also be a water-insoluble, alkali-soluble or swellable resin having phenolic hydroxy and / or carboxyl groups. Preferred water-insoluble, alkali-soluble or swellable resins used in connection with this embodiment of the invention contain phenolic hydroxy groups. Water-insoluble alkali-soluble or swellable resins suitable for use in the image-forming layer in connection with the present invention include, for example, synthetic novolak resins such as Reic
ALNOV is a registered trademark of hold Hoechst
DUREZ, a registered trademark of OL and OxyChem, and synthetic polyvinylphenols such as Dyno C
MARUKA LYN, a registered trademark of yanamid
CUR M.

The ink and the water-repellent phase according to the third embodiment of the first group of embodiments also comprise the ink and water-repellent thermoplastic particles, preferably silicon-based polymers or polymers containing perfluorinated alkyl groups. . Mixtures of the particles can also be used. The ratio by weight of ink and water-repellent thermoplastic particles to lipophilic binder is 1:10 to 10: 1.
, More preferably in the range of 1: 5 to 5: 1 and particularly preferably in the range of 1: 2 to 2: 1. In this embodiment, the coating of the recording layer is applied from an organic solvent for the lipophilic polymer.

The thermoplastic particles used in connection with this embodiment of the present invention have a coagulation temperature above 70 ° C. Coagulation can result from softening or melting of the thermoplastic particles under the influence of heat. There is no specific upper limit for the coagulation temperature of the thermoplastic particles, but the temperature must be well below the decomposition temperature of the thermoplastic polymer particles to avoid decomposition. A coagulation temperature at least 10 ° C. below the temperature at which the decomposition of the thermoplastic particles occurs is preferred. When such thermoplastic particles are subjected to temperatures above the coagulation temperature, they coagulate to form ink and water repellent agglomerates.

Suitable ink receptive or ink and water repellent polymers have a weight average molecular weight in the range of 5,000 to 1,000,000 daltons.

In a second group of embodiments of the present invention, the outermost layer contains a lipophilic phase and a hydrophilic phase, wherein the lipophilic thermoplastic particles are dispersed in a continuous phase containing a hydrophilic binder.

The hydrophilic binder used in connection with the present invention is preferably not crosslinked or only slightly crosslinked. Suitable hydrophilic binders for use in the second group of embodiments used according to the invention are water-soluble polymers or copolymers, which are synthetic, for example polyvinyl alcohol, polymers and copolymers of (meth) acrylic acid, (meth) Polymers and copolymers of acrylamide, polymers and copolymers of hydroxyethyl (meth) acrylate, polymers and copolymers of vinyl methyl ether, etc., or natural eg gelatin, polysaccharides such as dextran, pullulan, cellulose, gum arabic, alginic acid. it can.

It is also possible to use mixtures of the same or different types of hydrophilic binders.

Second Embodiment of the Embodiment Used According to the Invention
The hydrophobic thermoplastic particles used in connection with the group have a coagulation temperature of at least 70 ° C, preferably higher than 85 ° C. Coagulation can result from softening or melting of the thermoplastic particles under the influence of heat. There is no specific upper limit for the coagulation temperature of the thermoplastic particles, but the temperature must be well below the decomposition temperature of the thermoplastic polymer particles to avoid decomposition. A coagulation temperature at least 10 ° C. below the temperature at which the decomposition of the thermoplastic particles occurs is preferred. When such thermoplastic particles are subjected to temperatures above the coagulation temperature, they coagulate to form hydrophobic agglomerates, and the hydrophobic thermoplastic particles in these parts are insoluble in water or aqueous liquids. Becomes

Preferred lipophilic thermoplastic polymer particles for use in connection with the second group of embodiments used in accordance with the present invention having a Tg of greater than 85 ° C. are copolymers of vinyl chloride, vinylidene chloride, acrylonitrile, vinyl carbazole or the like. Contains polymers or mixtures thereof. Particularly preferred are copolymers and polymers of styrene or methyl methacrylate. Mixtures of latexes can also be used.

[0033] Suitable hydrophobic lipophilic thermoplastic polymers have a weight average molecular weight in the range of 5,000 to 1,000,000 daltons.

The hydrophobic lipophilic thermoplastic polymer particles have a particle diameter of 0.1%.
01 μm to 50 μm, more preferably 0.05 μm to 1
It can have a particle size of 0 μm and most preferably 0.05 μm to 2 μm.

The hydrophobic lipophilic thermoplastic polymer particles are present as a dispersion in the aqueous coating solution of the image forming layer,
It can be prepared by the method disclosed in US-P-3,476,937. Other methods particularly suitable for the preparation of aqueous dispersions of thermoplastic polymer particles are:-dissolving a hydrophobic thermoplastic polymer in an organic solvent immiscible with water;-dissolving the resulting solution in water or aqueous Dispersing in a medium-including removing the organic solvent by evaporation.

The amount of the hydrophobic lipophilic thermoplastic polymer particles contained in the image forming layer is preferably 20% to 90% by weight, more preferably 25% by weight when the layer contains a hydrophilic binder. ~ 85% by weight and most preferably 3%
0% to 80% by weight.

If the outermost layer contains a hydrophilic binder, it can also contain a crosslinking agent, but this is not required. Preferred crosslinking agents are low molecular weight substances containing methylol groups, such as melamine-formaldehyde resins, glycoluril-formaldehyde resins, thiourea-formaldehyde resins, guanamine-formaldehyde resins, benzoguanamine-formaldehyde resins. A plurality of the melamine-formaldehyde resins and glycolyl-formaldehyde resins are CYMEL (Dyno Cyan).
amid Co. , Ltd. ) And NIKALAC (S
anwa Chemical Co. , Ltd. ) Is commercially available under the trade name.

The thickness of the outermost layer preferably ranges from 0.2 to
It is within the range of 25 μm, more preferably within the range of 1 to 10 μm.

The thermoplastic particles, whether ink and water repellent thermoplastic particles or lipophilic thermoplastic particles, can contain a plasticizer or can be incorporated into the thermoplastic particles during the first development step. Can be diffused. The Tg of the thermoplastic particles referred to above is the Tg of the thermoplastic particles at the time they are totally exposed.

The light-addressable and thermally developable element according to the present invention comprises a substantially light-insensitive organic heavy metal salt, a light-sensitive silver halide in catalytic association therewith and a substantially light-insensitive light-sensitive material. Organic heavy metal salts and an organic reducing agent and a binder that are in a thermal working relationship with the organic heavy metal salt. The element is comprised of a silver halide in catalytic association with a substantially light-insensitive organic silver salt component, optionally with a supersensitizer in sensitizing association with silver halide grains. And a layer system in which the other components active in the thermal development process or before or after development of the element can be in the same or another layer, provided that the organic reduction The agent and the toning agent, if present, are in thermal working relationship with the substantially light-insensitive organic heavy metal salt, i.e., the reducing agent and, if present, the toning agent are substantially non-photosensitive during thermal development. It can diffuse into photosensitive organic heavy metal salts.

The outermost layer containing the two phases can be the outermost layer of the photo-addressable, thermally developable element, but preferably is the layer above the photo-addressable, thermally developable element. It is.

The substantially light-insensitive organic heavy metal salts according to the invention can be, for example, iron and gold salts, but are preferably silver salts, more preferably organic carboxylic acids, especially aliphatic carbon chains, preferably at least at least one. A silver salt of an aliphatic carboxylic acid known as a fatty acid having 12 C-atoms, such as silver laurate, the silver salt of which is also called "silver soap";
Silver palmitate, silver stearate, silver hydroxystearate, silver oleate and silver behenate; US-P 4,
504,575; silver di- (2-ethylhexyl) -sulfosuccinate described in EP-A 227 141. For example, GB-P
Aliphatic carboxylic acid modified with a thioether group described in 1,111,492 and GB-P 1,439,47
Other organic silver salts described in 8, for example, silver benzoate and silver phthalazinone can be used as well to produce thermally developable silver images. Furthermore, silver imidazolate and US-P
No. 4,260,677, which are substantially non-photosensitive inorganic or organic silver salt complexes.

The light-sensitive silver halide used in the present invention is 0.1 to 90 mole percent of a substantially light-insensitive organic silver salt; preferably 0.2 to 50 mole percent; particularly preferably 0.5 to 0.5 mole percent. ~ 35 mole percent; and especially can be used in the range of 1-12 mole percent.

The silver halide may be any photosensitive silver halide such as silver bromide, silver iodide, silver chloride, silver bromoiodide, silver chlorobromoiodide, silver chlorobromide and the like. it can. The silver halide can be in any form that is photosensitive, including but not limited to cubic, oblique, tabular, tetrahedral, octagonal, etc., and can have epitaxial growth of crystals thereon. .

The silver halide used in the present invention can be used without modification. However, it is possible to use chemical sensitizers such as compounds containing sulfur, selenium, tellurium, gold,
Chemical sensitization can be carried out using a compound containing platinum, palladium, iron, ruthenium, rhodium or iridium, a reducing agent such as tin halide, or a combination thereof. Details of these methods can be found in T.W. H.
James, “The Theory of the P
photographic Process ”, Fort
h Edition, Macmillan Publi
shingCo. Inc. , New York (197
7), Chapter 5, pages 149-16
9.

A suspension of particles containing a silver salt of a substantially light-insensitive organic carboxylic acid is described in EP-A 754 969.
By using a method comprising simultaneous metered addition of an aqueous solution or suspension of an organic carboxylic acid or a salt thereof and an aqueous solution of a silver salt to an aqueous liquid as described in (1).

The silver halide can be added to the light-addressable, thermally developable element in any manner that places it in catalytic proximity with a substantially light-insensitive organic silver salt. it can. Coating the silver halide and the substantially light-insensitive organic silver salt in a separately manufactured, i.e., ex-situ or "pre-manufactured" binder by mixing before use A liquid can be prepared, but it is also effective to blend both for a long time. Further, a halogen-containing compound is added to the organic silver salt to partially convert the substantially light-insensitive organic silver salt to silver halide, as disclosed in US Pat. No. 3,457,075. It is effective to use a method including.

In accordance with the present invention, a particularly preferred manner of preparing an emulsion of an organic silver salt and a photosensitive silver halide for coating a photo-addressable and thermally developable element from a solvent medium is described in US Pat. , 839, 049, but with a Research Discl.
osure, June 1978, item 1702
Other methods such as those described in US Pat. No. 9,700,458 and US Pat. No. 3,700,458 can also be used to prepare the emulsion.

In accordance with the present invention, a particularly preferred manner of preparing an emulsion of an organic silver salt and a light-sensitive silver halide for coating a photo-addressable, thermally developable element from an aqueous medium is disclosed in unpublished PCT- Application PCT / EP96 /
02579, the application of which is:
(I) providing a support; (ii) a substantially light-insensitive organic silver salt, a light-sensitive silver halide catalytically associated with the substantially light-insensitive organic silver salt, substantially Coating the support with a photo-addressable, thermally developable element comprising a reducing agent and a binder in thermal operation with the non-photosensitive organic silver salt, wherein the substantially light-insensitive Reacting an aqueous emulsion of grains of an organic silver salt with at least one onium salt having a halide or polyhalide anion to form a photosensitive silver halide as well as photo-addressable and thermally developable A method for making a photothermographic material is disclosed, wherein the element is coated from an aqueous dispersion medium.

Suitable organic reducing agents for the reduction of substantially light-insensitive organic heavy metal salts are mono-, bis-, tris-
Or tetrakis-phenol; mono- or bis-naphthol; di- or polyhydroxy-naphthalene; di- or polyhydroxybenzene; hydroxy monoethers such as alkoxynaphthols, e.g.
4-methoxy-1- according to SP 3,094,41.
Naphthol; pyrazolidin-3-one type reducing agents such as PHENIDONE ^™ ; pyrazolin-5-one; indane-1,3-dione derivative; hydroxytetronic acid; hydroxytetronimide; 3-pyrazolin; pyrazolone; For example, METOL ^™ ;
p-phenylenediamine, for example US-P 4,08
Hydroxylamine derivatives as described in US Pat. No. 2,901; reductones such as ascorbic acid; hydroxamic acids; hydrazine derivatives; amidoximes; at least one linked to O, N or C as in the case of n-hydroxyurea and the like. Organic compounds containing two active hydrogen atoms, US-P 3,074,809, 3,08
0,254, 3,094,417 and 3,887,37
See also FIG.

Among the useful aromatic di- and tri-hydroxy compounds having at least two hydroxy groups in the same aromatic nucleus, for example in the ortho- or para-position on the benzene nucleus, hydroquinone and substituted hydroquinone, catechol and substituted catechol Is preferred.

Among substituted catechols, ie reducing agents containing at least one benzene nucleus having two hydroxy groups (-OH) in the ortho position, 1,2-dihydroxybenzoic acid, 3- (3 ', 4' -Dihydroxyphenyl) propionic acid, pyrogallol, polyhydroxyspiro-bis-indane compounds, gallic acid, gallic esters such as methyl gallate, ethyl gallate and propyl gallate, tannic acid and 3,4-dihydroxy-benzoic ester Is preferred. Particularly preferred catechol type reducing agents are EP-A 692 733 and EP-A
599 369.

Polyphenols, such as 3M Dry S
bisphenols used in ilver ^™ materials,
Sulfonamidophenols and naphthols as used in Kodak Dacomatic ^™ materials are useful for photothermographic recording materials having photo-addressable and thermally developable elements based on photosensitive silver halide / organic silver salts / reducing agents. Particularly preferred.

During the thermal development process, the reducing agent must be present in such a way that it can diffuse into the substantially light-insensitive organic heavy metal salt particles and reduction of the organic heavy metal salt can take place. .

The heavy metal image density depends on the above-defined reducing agent and organic heavy metal salt coverage, and is preferably 80 ° C.
It must be possible to obtain an optical density of at least 1.5 when heated to higher temperatures. Preferably at least 0.10 mole of reducing agent is used per mole of organic heavy metal salt.

The above reducing agents, which are considered as primary or main reducing agents, can be used together with so-called auxiliary reducing agents. Auxiliary reducing agents that can be used in conjunction with the primary reducing agents described above are published in Periodic Research Discl.
osure, February 1979, item
17842, US-P 4,360,581 and 4,7
82,004 and sulfonamidophenols as described in EP-A 423 891.

Other auxiliary reducing agents which can be used together with the above-mentioned primary reducing agents to improve the gradation of heavy metal images are hydrazines as disclosed in EP-A 762 196; US Pat. No. 5,464. EP-A; sulfonyl hydrazide reducing agents as disclosed in U.S. Pat.
Alkenyl hydrazine as disclosed in U.S. Pat. No. 741,320; trityl hydrazide and formyl-phenyl- as disclosed in U.S. Pat. No. 5,496,695.
Hydrazide; US-P 5,545,505, US-P
5,637,449, US-P 5,545,507
And trityl and formyl-phenyl-hydrazine in combination with amines, hydroxamic acids, N-acyl-hydrazines and hydrogen atom donors as disclosed in US Pat. No. 5,558,983; EP-A 764.8.
Hydroxamic acid as disclosed in US Pat. No. 78;
5,545,515 and US-P 5,635,33
Acrylonitrile as disclosed in US Pat. No. 9,460,946 and 3,547,648.
Organic reducing metal salts, such as stannous stearate, as disclosed in US Pat. The printing plate requires a high gradient.

The photo-addressable and thermally developable element of the photothermographic materials of this invention can contain a spectral sensitizer for silver halide, optionally in combination with a supersensitizer. . Silver halide may optionally be in the presence of so-called supersensitizers, especially in the case of sensitization to red radiation, in the presence of various known dyes including cyanine, merocyanine, styryl, hemicyanine, oxonol, hemioxonol and xanthene dyes. It can be spectrally sensitized with a dye. Useful cyanine dyes include basic nuclei,
Examples include those having a thiazoline nucleus, oxazoline nucleus, pyrroline nucleus, pyridine nucleus, oxazole nucleus, thiazole nucleus, selenazole nucleus and imidazole nucleus. Preferred useful merocyanine dyes include not only the above-described basic nuclei, but also acid nuclei such as thiohydantoin nuclei, rhodanine nuclei, oxazolidinedione nuclei, thiazolidinedione nuclei,
Those having a barbituric acid nucleus, thiazolinone nucleus, malononitrile nucleus and pyrazolone nucleus are also included. Among the above cyanine and merocyanine dyes, those having an imino group or a carboxyl group are particularly effective. Suitable supersensitizers for use with red spectral sensitizers are EP-A's
559 228 and 587 338 and US-P '
s 3,877,943 and 4,873,184.

The film-forming binder for the light-addressable and thermally developable element used according to the present invention can be coatable from a solvent or an aqueous dispersion medium.

The film-forming binder for the photo-addressable and thermally developable element used according to the present invention can be coatable from a solvent dispersion medium according to the present invention, All kinds of natural, modified natural or synthetic resins or mixtures of such resins which can be homogeneously dispersed: for example polymers derived from α, β-ethylenically unsaturated compounds, for example polyvinyl chloride Post-chlorinated polyvinyl chloride, copolymer of vinyl chloride and vinylidene chloride, copolymer of vinyl chloride and vinyl acetate, polyvinyl acetate and partially hydrolyzed polyvinyl acetate, made from polyvinyl alcohol as starting material, repeated Polyvinyl alcohol, in which only some of the vinyl alcohol units can react with the aldehyde It can be a cetal, preferably polyvinyl butyral, a copolymer of acrylonitrile and acrylamide, polyacrylate, polymethacrylate, polystyrene and polyethylene or mixtures thereof. A particularly suitable polyvinyl butyral containing a small amount of vinyl alcohol units is MONS
BUTVAR ^™ B76 and B by ANTO USA
Sold under the trade name UTVAR ^tm B79 and exhibits excellent adhesion to paper and properly primed polyester supports.

The film-forming binder for the photo-addressable and thermally developable element coatable from the aqueous dispersion medium used in accordance with the present invention should be capable of uniformly dispersing the organic heavy metal salt. Or translucent water-dispersible or water-soluble natural, modified natural or synthetic resins or mixtures of such resins, for example proteins, such as gelatin and gelatin derivatives (for example phthaloyl gelatin) , Cellulose derivatives such as carboxymethylcellulose, polysaccharides such as dextran, starch ether, galactomannan, polyvinyl alcohol, polyvinylpyrrolidone, acrylamide polymers, homopolymerized or copolymerized acrylic or methacrylic acid, having or having a hydrophilic group And Latex had water dispersible polymer or may be a mixture thereof. Polymers having hydrophilic functional groups for the formation of aqueous polymer dispersions (latex) are described, for example, in U.S. Pat.
51, which serves for the formation of a barrier layer that prevents unwanted diffusion of vanadium pentoxide, which is present as an antistatic agent.

The weight ratio of binder to organic heavy metal salt is preferably in the range 0.2 to 6, and the thickness of the photo-addressable and thermally developable element is preferably in the range 1 to 50 μm. It is.

The above binders or mixtures thereof can be used in conjunction with waxes or “heat solvents”, also called “thermal solvents” or “thermosolvents”, which enhance the rate of redox reactions at elevated temperatures. . In the context of the present invention, the term "heat solvent" refers to a material that is in a solid state below 50 ° C. but becomes a plasticizer in the heated region and / or at least one of the redox reactants above 60 ° C.
For example, a non-hydrolyzable organic material that serves as a liquid solvent for a reducing agent for an organic heavy metal salt.

To obtain a pure black tone, the photo-addressable, thermally developable element contains a so-called toning agent known from thermography or photothermography in admixture with organic heavy metal salts and reducing agents. Is preferred.

Suitable toning agents are succinimide, phthalazine and phthalimide and US Pat. No. 4,082,9.
Phthalazinone and U within the general formula described in
SP 3,074,809, 3,446,648 and 3,844,797. Particularly useful toning agents are GB-P 1,439,478, US-P 3,
Benzoxazinedione or naphthoxazinedione type heterocyclic toner compounds described in US Pat. No. 951,660 and US Pat. No. 5,599,647.

To extend shelf life and reduce fog, stabilizers and antifoggants can be incorporated into the photo-addressable, thermally developable elements of the present invention. Examples of suitable stabilizers and antifoggants which can be used alone or in combination and their precursors include US-P 2,131,038 and 2,694,7
No. 16, a thiazolium salt; US-P 2,886.
Azaindenes according to 437 and 2,444,605;
Urazole according to US-P 3,287,135; U
Sulfocatechol according to SP 3,235,652; oxime according to GB-P 623,448; US
-P 3,220,839 thyuronium salt; U
Palladium, platinum and gold salts as described in SP 2,566,263 and 2,597,915; US-P 3,70
U.S. Pat. No. 0,457, tetrazolyl-thio-compounds;
-P 4,404,390 and 4,351,896, a mesoionic 1,2,4-triazolium-3-thiolate stabilizer precursor; a tribromomethyl ketone compound described in EP-A 600 587; EP- A 600
A combination of an isocyanate and a halogenated compound according to EP 586; a vinyl sulfone and a β-halosulfone compound according to EP-A600 589;
ging Processes and Materi
als, Neblette's 8th edition
n ", by D. Kloosterboer, edit
ed by J. Sturge, V .; Walworth
and A. Shepp, page 279, Van
Nostrand (1989) Chapter
9; Research Disc published in June 1978
loss 17029; as well as the compounds mentioned in this reference in all of the references cited therein.

In addition to the components, the photo-addressable and thermally developable element may contain other additives, such as free fatty acids, surfactants, antistatic agents, such as F ₃ C (CF ₂ ) ₆ CON.
Non containing fluorocarbon group as in _{H (CH 2 CH 2 O)} -H - ionic antistatic agent, silicone oil, for example BAYSILONE Oel A (BAYER AG
GERMANY), UV absorbing compounds, white light reflecting and / or UV reflecting pigments, silica, colloidal silica, polymeric microparticles [eg poly (methyl methacrylate)] and / or optical brighteners Can be contained.

The support for the photothermographic materials of the present invention can be transparent, translucent or opaque, for example, having a white light-reflecting surface, and is preferably coated, for example, with sheet metal, such as aluminum, paper, polyethylene. Paper or cellulose esters, for example cellulose triacetate, corona and flame treated polypropylene, polystyrene, polymethacrylate, polyimide, polycarbonate or polyester, for example GB 1,293,676, GB 1,44
1,304 and GB 1,454,956 are thin flexible carriers made from a transparent resin film made from polyethylene terephthalate or polyethylene naphthalate. For example, there are paper-based substrates that can contain white reflective pigments, and the pigment can optionally be applied to an interlayer between the photo-addressable and thermally developable element and the paper-based substrate. . The support can also be glass.

The support can be in the form of a sheet, ribbon or web, subbed if necessary to promote adhesion to the photo-addressable and thermally developable element coated thereon. Can be. The support can be made from an opaque resin composition, for example polyethylene terephthalate, opaque using pigments and / or micropores and / or by coating an opaque pigment-binder layer, Information on such supports can be referred to as synthetic paper or paper-like film; EP's 194 106 and 234 563 and US-P's 3,944,6
99, 4,187,113, 4,780,402 and 5,059,579. If a transparent base is to be used, the base may be substantially colorless or colored, for example having a blue color.

To obtain a lithographic printing plate, the photothermographic materials described above are exposed image-wise or information-wise to actinic light.

Actinic light is light that is absorbed by photo-addressable, thermally developable elements. UV light is actinic light in all cases. Blue light, green light and red light can be actinic light, depending on the composition of silver halide and optional spectral sensitization.

In a subsequent step, the exposed photothermographic material is heated to a temperature of at least 60 ° C. and at most 5 ° C. lower by the Tg of the thermoplastic particles to develop the substantially light-insensitive organic heavy metal salt. Preferably the temperature is in the range from 85C to 95C. The heating does not take long, preferably 2 to 30 seconds, more preferably 5 to 2 seconds.
0 seconds.

In the last step, the image-wise exposed and heated photothermographic material is globally exposed to a light source that emits light having a wavelength that is absorbed by the heavy metal image.

The image-exposed and heated photothermographic material is exposed to light when the image-
The image area of the exposed and heated photothermographic material is warmed to a temperature above the Tg of the thermoplastic particles and at least 10 ° C. below the decomposition temperature of the thermoplastic particles. In most cases, a temperature of 110-150C is preferred.

The overall exposure was an IR-illuminator and I
It is preferably performed using a light source selected from the group consisting of R-lasers.

It should be noted that the photothermographic materials of the present invention can provide anhydrous offset printing plates as well as printing plates that require water or dampening solution for printing. In fact, the photothermographic recording materials according to the first group of embodiments of the invention in which the outermost layer contains an ink-receptive phase and an ink and a water-repellent phase give an anhydrous offset printing plate. Photothermographic recording materials according to the second group of embodiments of the invention, in which the outermost layer contains a lipophilic phase as well as a hydrophilic phase, provide printing plates that require water or a fountain solution for printing.

The following examples illustrate the present invention without limiting it. All parts are by weight unless otherwise specified.

[0078]

【Example】

Example 1 Light - coated with a layer having the following composition addressable thermally developable layer preparation subbed polyethylene terephthalate support on - silver behenate 4.00g / m ² - (2- tri triphenylphosphonium) propionic acid iodide 0.30 g / m ² - methyl methacrylate, copolymers 4.00g / m ² -3- (3 butadiene and itaconic acid ', 4'-dihydroxyphenyl) propionic acid 0.70 g / m ² - Preparation of phthalazine 0.20 g / m ² outermost layer 4 g in 25.5 g of 5.5 wt% polyvinyl alcohol
A dispersion is prepared by adding Syloid ^™ 161 (SiO ₂ matting agent with an average diameter of 4 μm from Grace). To this dispersion is added 7 g of a 20% by weight polystyrene dispersion and 2.1 g of 23.8% by weight of tetramethyl orthosilicate. The dispersion is diluted with deionized water to a final volume of 40 ml. The resulting dispersion is mixed well and applied to a final wet thickness of 30 μm on the photo-addressable and thermally developable layer in red light.

Preparation of printing plate The dried plate was placed on a metal halogen lamp CDLi 1205.
Image on contact illuminator (80 units, level 3)
Exposure as follows. Place the exposed material on a hot plate at 90 ° C for 1
The silver image is developed by heating for 0 seconds. The plate is subsequently irradiated by an IR-lamp to a final temperature of 120-130 ° C. at the surface of the printing plate.

The printing plate obtained in this way was applied to a Van Son
Rubberbase as ink, 2% Time
Was printed as a dampening solution on an ABDick 360 printing press.

Example 2 A coating solution is prepared by mixing 10 g of a 20% silver behenate dispersion and 13.33 g of 1.24% tri-phenyl-phosphonium propionate iodide. Mix the solution thoroughly for 15 minutes. The solution is then stirred under constant stirring with 2.0 g having an average diameter of 4 μm.
Of SiO ₂ (Grace Gmbh, sold by Germany Syloed 161), 5.5% solution of polyvinyl alcohol 12.75g and 5.8
g to a dispersion containing 12.45% polystyrene dispersion.

To this dispersion, under constant stirring, 1.0 g of a 24.88% solution of tetramethylorthosilicate, 2.16 g of a 5.6% solution of phthalazinone and 5.4% solution of dihydroxyphenylpropionic acid. 6.66 g are added. After mixing, the dispersion is coated on a subbed polyethylene terephthalate support using a 100 μm coating knife. The layer is dried at a temperature of 40 ° C. for 5 hours.

The layers are image-wise exposed using CDL 1205 (1200 W metal halogen lamp; 8 seconds; level 3). The images are processed on a warm surface at a temperature of 90 ° C. for 10 seconds. The imaged element is now globally exposed for 10 seconds to an IR-emitter (Elstein FSR-250W). The plate is then used as a wet offset plate on an ABDick 360 printing press using Van Son Rubberbase ink and 2% Name dampening solution. A clean printed image was obtained.

Example 3 4.06 g of a 12.45% polystyrene dispersion was added to 4.0
g of a 50% silicon emulsion (Dehes from Wacker)
The coating solution is prepared by mixing with 0.81 g of a 37% solution of ive 410E) and a crosslinker (crosslinker V72 from Wacker). The dispersion is then made up to a volume of 10 ml with water. Mix the dispersion thoroughly,
Coating in red light on the photo-addressable thermally developable layer described in Example 1 using a 10 μm coating knife. The layer is then dried at a temperature of 60 ° C. for 6 hours.

The layer is image-wise exposed using CDL 1205 (1200 W metal halogen lamp; 8 seconds; level 3). The images are processed on a warm surface at a temperature of 90 ° C. for 10 seconds. The imaged element is scanned entirely using a NdYLF laser (1053 nm), this time at a drum speed of 2 m / s, an output level of 200 mw and a spot diameter of 16 μm.

[0086] The plate was then transferred to a Hostmann-Steinberg Refl on an ABDick 9860 printing press.
ecta dry ink (magenta) is used as an anhydrous printing plate.

The main features and aspects of the present invention are as follows.

1. A substantially light-insensitive organic heavy metal salt, a light-sensitive silver halide in catalytic association with the substantially light-insensitive organic heavy metal salt, for the substantially light-insensitive organic heavy metal salt A photo-addressable and thermally developable element containing a reducing agent and a binder on a support, wherein the photo-addressable and thermally developable element comprises 2 on the same side of the support as the photo-addressable and thermally developable element. A photothermographic material having an outermost layer having a phase, wherein at least one of the two phases is a dispersed phase of thermoplastic particles, wherein the two phases are selected from the group consisting of ink and an adhesive liquid for the ink. A photothermographic material characterized by exhibiting different affinities for at least one printing liquid to be obtained.

2. 2. A photothermographic material according to claim 1, wherein said outermost layer contains an ink receptive phase and an ink and water repellent phase.

3. 3. A photothermographic material according to claim 2 wherein said ink receptive phase comprises a continuous hydrophilic binder.

4. 3. The photothermographic material of claim 2 wherein said ink receptive phase comprises a lipophilic polymer latex.

[0092] 5. 3. A photothermographic material according to claim 2 wherein said ink receptive phase comprises a continuous lipophilic binder.

6. 2. The photothermographic material according to claim 1, wherein said outermost layer contains a lipophilic phase and a hydrophilic phase.

7. A photothermographic material according to claim 1, wherein the thermoplastic particles have a coagulation temperature of at least 70 ° C.

8. Item 8. The photothermographic material according to any one of Items 1 to 7, wherein the thickness of the outermost layer is in the range of 0.2 to 25 µm.

9. The photothermographic material according to any one of claims 1 to 7, wherein the substantially light-insensitive organic heavy metal salt is a substantially light-insensitive organic silver salt.

10. (A) exposing the recording material according to 1 to 9 above to actinic radiation image-wise or information-wise;
(B) developing the substantially light-insensitive organic heavy metal salt by exposing the recording material to a temperature of at least 65 ° C. and up to 5 ° C. below the Tg of the thermoplastic particles, thereby forming a heavy metal image; (C) exposing the outermost layer entirely using a light source that emits light having a wavelength that is absorbed by the heavy metal image, and adjusting the temperature of the outermost layer to the Tg of the thermoplastic particles;
A method for obtaining a lithographic printing plate comprising the step of image-wise raising to a higher temperature.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI G03F 7/00 503 B41M 5/18 102Z

Claims (2)

[Claims] 1. A substantially light-insensitive organic heavy metal salt, a light-sensitive silver halide in catalytic association with said substantially light-insensitive organic heavy metal salt, A photo-addressable and thermally developable element containing a reducing agent and a binder for an organic heavy metal salt is provided on a support, wherein the photo-addressable
An outermost layer having two phases on the same side of the support as the addressable and thermally developable element, wherein at least one of the two phases
One is a photothermographic material that is a dispersed phase of thermoplastic particles, wherein the two phases exhibit different affinities for at least one printing liquid selected from the group consisting of ink and an adhesive liquid for the ink. Photothermographic materials. 2. The method of claim 1, wherein (a) exposing the recording material of claim 1 to actinic radiation image-wise or information-wise, and (b) exposing the recording material to at least 65 ° C. and up to thermoplastic particles. Developing a substantially light-insensitive organic heavy metal salt by exposing it to a temperature 5 ° C. below Tg, thereby forming a heavy metal image; (c) providing a light source that emits light having a wavelength that is absorbed by the heavy metal image. A method for obtaining a lithographic printing plate, comprising the steps of: exposing the outermost layer entirely using the method to raise the temperature of the outermost layer imagewise to a temperature higher than the Tg of the thermoplastic particles.