JPH02203346A - Production of negative type planographic printing plate - Google Patents

Abstract

PURPOSE:To eliminate fogging at the time of forming metallic images and to obtain the sufficient metallic image forming speed and image strength in high-temp. rapid processing by an automatic developing machine by incorporating a specific compd. into a photosensitive photographic element. CONSTITUTION:The compd. expressed by the formula I is incorporated into the photosensitive photographic element. In the formula I, n denotes >=1 integer; m denotes a hydrogen atom or alkaline metal. Namely, the development acceleration effect by the compd. expressed by the formula I is admitted when the photosensitive photographic element is subjected to a development processing after image exposing. The speed of forming the metallic images is thereby highly accelerated and the secure metallic images having excellent printing resistance are obtd. when this element is used as a printing plate.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Technical Field The present invention relates to a method for producing a negative planographic printing plate using a negative diffusion transfer image forming method.

(B) Prior art and its problems A method is already widely known in which a silver image is formed using a silver salt diffusion transfer method, and the image is subjected to oil sensitization treatment to be used as a lithographic printing plate.

That is, in the above method, after the silver halide coated on the support is imagewise exposed, the silver halide in the exposed area is converted to reduced silver by a treatment containing a developer and a silver halide solvent; The silver halide in the unexposed area is dissolved by the action of a silver halide solvent and deposited as physically developed silver on the adjacent physical development nuclei, and the positive silver image thus obtained is further exposed to light. By turning it into a fat, it becomes a lithographic printing plate that can be used directly for printing. Examples include Special Publication No. 36-10910 and No. 36-1871.
The technology is described in detail in No. 9 or No. 48-30562.

However, all printing plates obtained by the method for producing a lithographic printing plate using the above-described diffusion transfer method are positive printing plates, and cannot be used when producing a lithographic printing plate directly from a negative original.

Furthermore, in direct plate making using a laser scanner, which has recently become widely used, negative type printing is theoretically more advantageous than positive type printing.

On the other hand, little is known about the manufacturing method of lithographic printing plates using the negative silver salt diffusion transfer method.
As a slightly more recent example, JP-A-57-44153 discloses a method in which non-photosensitive, easily soluble metal salt particles that have been made poorly soluble are dissolved out by the physicochemical action that occurs during development of photosensitive silver halide in the exposed area. A method of forming a metal image on a physical development nucleus and sensitizing it is described, and an improved method of the above method is described in JP-A-57-150849. In both cases, metal salt particles that have been treated to make them difficult to solubilize are used as negative image forming materials, so the image formation speed during development is slow. It also has the disadvantage of adversely affecting storage stability.

Therefore, the present inventors have developed a method for producing a negative planographic printing plate that does not have these drawbacks, has a short processing time, and has excellent transfer efficiency of metal salt particles to an image. 2> Particles of metal salt that have substantially no photosensitivity 3> React with the oxidized developing agent produced by development to form the particles described in <2> above.
A compound that releases a compound that acts as a dissolving agent or dissolution physical promoter for metal salt particles (＾gX SoLwen
t Re1essiB Redox Compound
s.

(hereinafter abbreviated as SRR compound) <4> A compound containing physical development nuclei was proposed (Japanese Patent Application Laid-Open No. 60-196764
(No. 1) This negative-tone sensitive material is processed with a developer containing a metal salt particle reducing agent to cause the development of the photosensitive silver halide described in item 1 above in the exposed area, and the effect of the oxidized developing agent produced. An image is obtained by depositing the metal ions or metal complex ions generated from the above-mentioned <2> and <3> as metals on the physical development nuclei of (4).

This method has the above-mentioned advantages and is also excellent in storage stability, but because development is amplified, even a small amount of oxidized developing agent may exist in the system due to air oxidation. It also had the disadvantage of being prone to fogging.

Therefore, the present inventors further added to the above system <5> pH 13,
We proposed a compound containing an electron-donating compound that has a lower oxidation potential than the compound <3> in a buffer solution (25°C) of 0.0°C.

(Japanese Unexamined Patent Publication No. 61-17325) This method has low fog, high sensitivity, high contrast, and excellent metal image forming efficiency, but as a reducing agent for metal salt particles in (2), Because it is not possible to use a strong reducing agent that would interfere with the reaction of the SRR compound, the formation speed and image strength of the metal image on the printing plate are particularly low during high-temperature, rapid processing using recent automatic processors (hereinafter referred to as automatic processors). However, it is still insufficient to be used as such, and further improvements have been desired in these respects.

(C) Object of the Invention The object of the present invention is to provide a novel method for producing a negative lithographic printing plate that has sufficient metal image formation speed and image strength even in high-temperature rapid processing using an automatic processor.

(D) Structure of the Invention The present invention comprises (1) photosensitive silver halide, (2)
Metal salt particles that have substantially no photosensitivity; (3) a compound that reacts with the oxidized developing agent produced by development and acts as a dissolving agent or a dissolved physical development accelerator for the metal salt particles mentioned in (2) above; A light-sensitive photographic element containing a combination of a compound to be released and (4) physical development nuclei is imagewise exposed and then developed to selectively remove the metal salt particles of (2) above in the exposed areas. Production of a negative-working lithographic printing plate characterized in that the photosensitive photographic element contains a compound represented by (I) in a method for producing a negative-working lithographic printing plate comprising the step of depositing a metal image on physical development nuclei. A method by which the above object can be achieved.

[I] (In CI), n is an integer of 1 or more, and M is a hydrogen atom or an alkali metal) That is, when the photosensitive photographic element of the present invention is imagewise exposed and then developed, (1 ) Development of the photosensitive silver halide occurs, producing an oxidized developing agent, which reacts with the SRR compound (3) and releases a compound that acts as a dissolving agent or dissolving physical development accelerator for metal salt particles. , the dissolution or dissolution physical development of the metal salt particles in (2) is promoted, and a negative-like metal image is deposited on the physical development nuclei in (4). By keeping it in place, a development promotion effect far beyond expectations was observed, greatly accelerating the formation speed of metal images, and when used as a printing plate, it was possible to obtain strong metal images with excellent printing durability. was completed.

As the compound [I] of the present invention, preferably n=1 to 4
A compound of M is used, and as M, a compound of M= or Na is preferably used.

As specific examples of the compound (I) used in the present invention, the following compounds are preferably used, but the present invention is not limited thereto.

H H 1゜(In To synthesize the above compounds, as shown in the formula below, first synthesize the corresponding bis-hydroquinone [■], and then sulfonate it using an appropriate method to produce CI). However, for the synthesis of this bis-hydroquinone [■], Die
Makromolekulsye Cbemie108
Volume 198-200 (1967) and other methods were used, and the method for sulfonation of [■] was B.
Synthesis of CI) was carried out using the method described in J. Ull, Soc, Chim Belgls, Vol. 74, pp. 397-406 (1965).

(Hereinafter, blank space) These compounds are added in an amount of 0.0 per 1 d of the photosensitive element of the present invention.
It is used in a range of 5 to 50 moles.

Further, these compounds may be used alone or in combination.

The photosensitive silver halide (1) used in the present invention includes silver chloride, silver bromide, silver iodide, silver chlorobromide, silver chloroiodide, silver iodobromide, silver chloroiodobromide, or these. Although a mixture or the like may be used, preferably silver bromide having high sensitivity or silver iodobromide containing 10 mol % or less of silver iodide is suitable for the present invention. Further, the photographic emulsion containing silver halide in the present invention is prepared by a conventional manufacturing method. Further, the silver halide grains used in the present invention include those having various crystal habits. This silver halide emulsion can be sensitized using various sensitizers, it can also be spectrally sensitized using sensitizing dyes to impart photosensitivity to a desired spectral region, and it can also be sensitized using various sensitizers. It can also be stabilized using a stabilizing agent.

The non-photosensitive metal salt particles (2) used in the present invention are (
The dissolution rate of the metal salt particles released from the compound (3) in the dissolving agent is higher than that of the photosensitive silver halide (1), and the compound is a metal salt having substantially no photosensitivity.

In the present invention, "substantially not having photosensitivity" means not being photosensitized relative to the photosensitive silver halide in (1) above, and specifically, ( 1)
This means that when the light energy required to sensitize the light-sensitive silver halide of the present invention is applied to the light-sensitive photographic element of the present invention, it will not be substantially exposed to light at that light energy. In the present invention, the term "non-photosensitive" is also used synonymously.

The non-photosensitive metal salt particles (2) used in the present invention may be selected from those having the above-mentioned properties, but in a preferred embodiment of the present invention, the non-photosensitive metal salt particles (2) are substantially photosensitive. These silver halide grains have a higher dissolution rate in a dissolving agent than the photosensitive silver halide grains of (1) above.

More specifically, the metal salt particles preferably applied to the present invention are pure silver chloride that has not been subjected to chemical sensitization treatment or salt odor particles that have been subjected to desensitization treatment and that contain 5 mol% or less silver bromide. Silver chloride, silver chloroiodide containing 1 mol% or less of silver iodide, or a mixed silver halide thereof, which preferably has finer crystals than the photosensitive silver halide described in (1) above; The metal salt particles are used in an amount of 0.1 mol to 100 mol per mol of photosensitive silver halide in (1),
It is preferably used in a range of 1 mol to 10 mol.

The compound (3) which releases a solubilizing agent or a dissolved physical development accelerator (SRR compound) used in the present invention means a compound represented by the following general formula (III).

NH30□ A-B (III) In formula (m), A is oxidized by cross-oxidation with the oxidized developing agent, and the subsequent hydrolysis reaction, elimination reaction, substitution reaction, or cyclization reaction occurs under alkaline conditions. A redox mother nucleus having the function of releasing a B residue is prepared by using the above method, and B forms a substituent that forms a compound exhibiting a metal salt particle dissolving action or a dissolution physical development promoting action when released from A. A may have a ballast group attached to it to immobilize it in the photographic element.

Described in H3O2 3,928312 US, 4.053.312 Described herein as A is preferably a negative-acting dye-releasing redox compound (Dillusible Dye Releases) commonly known in color diffusion transfer processes.
ing Redox Compounds, hereinafter referred to as DRR
The redox nucleus of the compound (abbreviated as "compound") is used.

Representative examples are shown below.

Described in US, 4 155, 428 Described in US, 4.336 322 HuuH Described in JP-A-59-65839 Ballist HSO2 H Described in JP-A-51-104.34'3 JP-A-53-3. Bxllxsj Described in JP-A-51-014.343 H US, Described in 3.725.062 H Described in Research Disclosure Magazine, No. 17,465 US, Described in 3.443.939 Oxidation as above All reduced cores are SR used in the present invention.
It can be used as a redox mother nucleus for R compounds.

Here, Bxllast represents an organic ballast group, and in the present invention, this is preferably a group containing a hydrophobic group having 8 to 50 carbon atoms.

The mechanism of B residue release by development is the same as the mechanism of dye release of DRR compounds in color diffusion transfer method,
ev, Chem, lnl, Ed, Engl,
It is described in detail in reviews such as Vol. 22, p. 191209 (1983) or Organic Synthetic Chemistry, Vol. 39, No. 4, pp. 331-344 (1981). As the B residue, a substituent that forms a compound that exhibits a metal particle dissolving action or a dissolution physical development promoting action, which is known in the field of photographic light-sensitive materials, is usually used, but more preferably a redox mother nucleus of the DRR compound is used. In addition to heterocyclic compounds such as substituted uracil, substituted hydantoin, substituted imidazolidine thione, substituted thiazolidinethione, and substituted oxazolidinethione, which are bonded to via a sulfonamide group, as well as chain substituted thioethers, substituted amino alcohols, etc. Compounds conventionally known as silver halide solvents or silver halide dissolution physical accelerators in the field of silver salt photosensitive materials are used.

The following compounds are used as examples of the SRR compound (III).

RR-1 H (blank below) 5RR-2 RR RR-6 H RR-7 OC+sLi C3HI + (1) RR-4 RR-5 H RR-8 0CRs)In RR-9 C(CH,)3 5RR-10 OH These compounds may be used alone or in combination. In addition, when [I [I] is used as a solubilizer or a dissolved physical development accelerator-releasing compound, the redox mother nucleus A of (III) among the developing agents used in the development of ordinary photographic light-sensitive materials can be used as a developing agent. Any compound that forms an oxidant capable of cross-oxidizing may be used, but a preferred example is a 1-phenyl-3-pyrazolidinone derivative that is commonly used as a cross-oxidizing agent in color diffusion transfer materials. The developing agent may be contained in the processing solution or in the photosensitive material.

The physical development nucleus (4) in the present invention has the function of catalytically promoting the reaction in which metal ions or metal complex ions produced by dissolving the metal salt particles (2) are reduced to metal by a reducing agent. Indicates a substance that has As examples, metal sulfide colloids, noble metal colloids, etc. are used, and more specifically, palladium sulfide, nickel sulfide, silver sulfide, metal silver colloids, metal palladium colloids, etc. are preferably used.

The negative planographic printing plate according to the present invention basically includes at least one support and the above-mentioned (1) photosensitive silver halide (2).
Metal salt particles having substantially no photosensitivity (3) React with the oxidized developing agent produced by development to release a compound that acts as a dissolving agent or dissolved physical development accelerator for the metal salt particles mentioned in (2) above. Compound (4) Physical development nucleus and CI
), but (1), (2
), (3), (4) and (I) may be contained in a single layer, or a layer containing two or more of them in any combination may be included. good.

Also, the order of the layers can take various configurations, and (1
), (2), (3), (4) and [I] may be separately contained on multiple supports in any combination and layer configuration, and may be configured to be used together. .

A particularly preferred layer structure of the negative planographic printing plate according to the present invention is that (1), (2), (3) and C
Apply a layer containing a mixture of the champion of I), and then apply (
Either a layer containing 4) is coated to form a two-layer structure, or a layer containing a mixture of (1) and (3) is coated on the support, and then (2) and [! ], and then a layer containing (4) is coated on top of it to form a three-layer structure, or alternatively, a layer containing (+) is coated on the support, and a layer containing (2) is coated on top of that. ), (3) and (I) are coated, and a layer containing (4) is further coated on top of that to form a three-layer structure.

Furthermore, depending on the purpose, the photographic element of the present invention may have appropriate layers at various positions as long as the effects of the present invention are not impaired, such as a protective layer, an intermediate layer, an antihalation layer, or a backing layer. It may also be in a so-called activated form, which includes a layer containing a developing agent.

Furthermore, in the photographic element of the present invention, photographic additives other than those described above may be added to any layer of the photographic element, depending on the purpose, to the extent that the effects of the present invention are not impaired. In order to particularly improve or improve printing properties such as water retention and printing durability, fine powder particles such as silica gel, colloidal silica, silicon dioxide, magnesium oxide, titanium dioxide, calcium carbonate, etc. may be used in any layer. can. Further, hardeners commonly used in the art can be used to strengthen adhesion to the support and physical properties of the film, and surfactants can also be used to improve the coating stability of the coating solution.

Next, any support can be used in the present invention as long as it has a hydrophilic surface.

For example, baryta paper, polyethylene-coated paper, cellulose acetate, polyester film such as polyethylene terephthalate, polyamide film, polystyrene film, glass plate, which has been subjected to corona discharge treatment, undercoating treatment, etc., or aluminum which has been anodized. Metal plates such as plates are included, but particularly preferred are polyethylene-coated paper, polyester films, and aluminum plates. Further, as the surface hydrophilic treatment methods such as the corona discharge treatment, undercoating treatment, and anodizing treatment, known methods commonly used in the art can be used.

Hereinafter, the present invention will be explained in more detail using typical examples, but the technical scope of the present invention is not limited thereby.

Example 1 (a) Preparation method of high-sensitivity silver iodobromide emulsion (r(1) Preparation of photosensitive silver halide grains) Iodide odor is removed from silver nitrate, potassium bromide, and potassium iodide by an ordinary neutral method. A silveride emulsion (silver iodide 2 mol %) was prepared, chemically sensitized by gold and sulfur sensitization, and 4-hydroxy-6-methyl-1,3,3a,'r-tetrazaine was added as a stabilizer. Den was added to obtain a silver iodobromide emulsion with a grain size of 0.4 microns.

(b) Preparation method of desensitized silver chlorobromide emulsion (r(2) Preparation of non-photosensitive metal salt particles) Desensitized salt odor using rhodium chloride as a desensitizer to silver nitrate, sodium chloride, and potassium bromide Silver bromide emulsion (silver bromide 1
2 mol%) was prepared.

The grain size of the resulting emulsion grains was 0.1 micron.

(c) Preparation of physical development nuclei Physical development nuclei consisting of silver sulfide were prepared with sodium sulfide and silver nitrate in an aqueous polyvinyl alcohol solution.

(a) High-sensitivity silver iodobromide emulsion (b) prepared as described above
) Desensitized silver chlorobromide emulsion (c) Physical development nuclei (d) Separately synthesized silver halide solvent-releasing redox compound 5RR-6
Gel containing in gelatin by oil dispersion method,
and (e) separately synthesized compound of the present invention 1. The following inventive samples and comparative samples were prepared by applying gelatin gel containing the following on a paper support.

Sample 1-1 (sample of the present invention) A layer containing (a) and (d) is coated, a layer containing (b) and (e) is coated, and a layer containing (c) is further coated on top of that. Sample 1-2 (comparative sample) A sample in which a layer containing (a) and (d) was coated, a layer containing (b) was coated, and a layer containing (C) was further coated on top of that. For all samples, the coated silver amount was 0.25 g/% for the high-sensitivity silver iodobromide emulsion (a), and the coated silver amount was 0.50 g/% for the desensitized silver chlorobromide emulsion (b). rd
, For palladium sulfide in (c), the coating amount is 6×
10-1'mol/11? , (d) (7) For the SRR compound (SRR-6), the coating amount is 0°5 mmol/r.
For d and (e), the coating amount is ■0.05 mmol/rr? , ■0.1 mmol/nf.

The coating was carried out so that (1) the concentration was 0.2 mmol/rrr, and (2) the concentration was 0.5 mmol/a.

The above samples were wedge exposed to light at 4.5 CMC and then developed for 20 seconds at 25° C. with a developer having the following composition.

After development, the sample was fixed using a commercially available Kodak F-5 fixer (manufactured by Eastman Kodak, USA), washed with water, and dried. The silver content of the sample was measured, and the results shown in Table 1 were obtained. Ta.

(Hereinafter referred to as margins) From the above results, it can be understood that the method of the present invention can provide a novel negative planographic printing plate in which a sufficient amount of metal images can be formed even in a short processing time.

Example 2 An emulsion prepared by mixing (a) the same high-sensitivity silver iodobromide emulsion used in Example 1 and (d) gelatin gel in which 5RR-6 was dispersed in oil was placed on a paper support. The coating amount of (d) is 0.3g as silver, and the coating amount of SRR (d) is 0.5g.
mmol/n! The desensitized silver chlorobromide emulsion (b), which is also the same as that used in Example 1, and (
f) Thyroid 5Y-308 (silica gel powder, manufactured by Fuji Davison) was mixed with (e) Compounds 1, 3. and 5. The coating amount of (b) was 0 as silver, and the emulsion containing nothing as a comparison.
．． 6g/rd, coating amount of (f) is 0゜5g/rr
The coating amounts of f and (e) were each 0.2 mmol/a.

Furthermore, the same physical development nuclei (C) as used in Example 1 were coated on top of this in an amount of 3 x 10-' mol/g of palladium sulfide to obtain the inventive samples and comparative samples shown below. Created.

Sample 2-1 (sample of the present invention): Contains compound 1 of the present invention The results are shown in Table 2.

(Leaving space below) '2-1 ■ (): Contains 12-1 ■ (): Contains '2-2 (comparative sample): Contains nothing Sample of the present invention with three-layer structure prepared as above After imagewise exposing 2-1 and comparative sample 2-2, the following developer and Example 1 were applied.
Processing was carried out using the same fixing solution used in , and varying the processing time.

(However, the development temperature was 35°C.) The surfaces of the above inventive samples and comparative samples were coated with SLM.
After wiping with -OH liquid (oil sensitizing liquid, manufactured by Mitsubishi Paper Industries) and applying oil sensitization, use regular offset printing ink.
When SLM-OD liquid (manufactured by Mitsubishi Paper Corporation) was used as a wetting liquid and applied to an offset printing machine, sample 2-1 of the present invention was obtained.
For ■ to ■, clear ink images with no ink stains in the non-exposed areas were obtained for both samples with a development time of 10 seconds and 30 seconds, whereas in comparison sample 2-2, the sample with a development time of 10 seconds The ink image in the exposed area was not blurred at all, and with the development time of 30 seconds, the ink stain in the non-exposed area was so severe that a clear ink image could not be obtained.

From the above, it can be understood that the present invention is an excellent method for producing a negative planographic printing plate that has an excellent image forming speed and little fog.

Example 3 The same highly sensitive silver iodobromide emulsion (a) as used in Example 1, the desensitized silver chlorobromide emulsion (b), the physical development nuclei of (C) and Example 2 were deposited on a polyethylene terephthalate film. A sample having the same configuration and the same coating amount as that prepared in Example 2 is prepared using Thyroid 5Y-308 (f), which is the same as that used in Example 2. However, as the SRR compound of d), 5RR-6
Instead, 5RR-10 (application amount 0.6 mmol/-)
In addition, in Sample 3-1 (sample of the present invention), the compound of the present invention (coating amount 0.3 mmol/r) was applied to the non-photosensitive gelatin layer.
d), and in Sample 3-2 (comparative sample), nothing was added to the non-photosensitive gelatin layer. Above samples 3-1 and 3-
2 was exposed, developed, fixed and sensitized in the same manner as in Example 2 to obtain a printing plate. (However, development time is 25 seconds) When the printing plate thus obtained was run on an offset printing machine in the same manner as in Example 2, a clear image without ink stains was obtained in Sample 3-1 of the present invention. It also had a printing life of more than 1000 copies,
Comparative sample 3-2 had a lot of ink stains in the non-exposed area, and
The silver image in the exposed area also peeled off after printing about 100 copies, making it impossible to print.

From the above, it can be understood that the present invention is a method for producing a negative planographic printing plate that is free from fog and has excellent printing durability.

Claims (1)

[Scope of Claims] 1. On a support, (1) photosensitive silver halide, (2) metal salt particles having substantially no photosensitivity, and (3) reacting with an oxidized developing agent produced by development. A photosensitive photographic element containing a combination of (2) a compound that releases a compound acting as a dissolving agent or a dissolved physical development accelerator, and (4) physical development nuclei is imagewise exposed and then developed. In a method for producing a negative planographic plate, which comprises a step of selectively precipitating the metal salt particles of the above (2) in the exposed area as a metal on the physical development nuclei of the above (4) by processing, the metal salt particles in the photosensitive photographic element are A method for producing a negative lithographic printing plate characterized by containing a compound represented by [I]. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [I] (However, in [I], n is an integer of 1 or more, and M represents a hydrogen atom or an alkali metal)