JP2999009B2 - Lithographic printing plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photographic light-sensitive material for producing a lithographic printing plate to which a silver complex salt diffusion transfer method is applied. In particular, the present invention relates to an improved lithographic printing plate having high sensitivity, little print smear, and excellent storage stability.

[0002]

2. Description of the Related Art A lithographic printing plate utilizing a silver complex salt diffusion transfer method is composed of an oleophilic image portion that accepts oily ink and an oil-repellent non-image portion that does not accept ink. The image portion includes a hydrophilic portion that receives water. In a normal lithographic printing plate, therefore, both water and ink are supplied to the plate surface, and the image area contains colored ink.
The non-image area is formed by selectively receiving water and transferring the ink on the image to a substrate such as paper. Therefore, in order to obtain good printed matter, the difference between the lipophilicity and hydrophilicity of the surface of the image area and the background non-image area is sufficiently large, and when water and ink are applied, the image area has a sufficient amount. It is necessary that the non-image portion accepts no ink and does not accept the ink at all.

A printing plate has already been realized in which a silver metal salt image formed by applying a silver complex salt diffusion transfer method is made lipophilic and used as ink receptivity. The present invention relates to Japanese Patent Publication No. 48-30562 and Japanese Patent Application Laid-Open No.
1602, 54-103104, etc., starting from a lithographic printing plate material having a physical development nucleus layer comprising a heavy metal or its sulfide on a silver halide emulsion layer, its printing characteristics, and The present invention relates to a novel material having improved photographic properties. As described above, the ideal as a lithographic printing plate is that the image portion accepts ink well, while the non-image portion does not accept ink at all, and no printing stain occurs. For this purpose, various methods of desensitizing are studied according to the respective plate materials and printing methods.

In general, it is well known in the art that the occurrence of print stains in lithographic printing is not a single cause but is caused by various factors overlapping. It is, for example, due to the inherent properties of the plate material, or due to printing ink, dampening solution, printing paper, and furthermore the condition of the printing press or the temperature at the time of printing. Or the effects of environmental conditions such as humidity. At the time of printing, it is important to properly maintain such conditions and environment. However, from a practical point of view, a material that can be printed under the widest possible conditions is required.

In recent years, as the amount of information has increased,
In view of the strong demand for faster information processing, it is desired to shorten the plate making time, that is, to increase the sensitivity of the photosensitive printing material.

[0006]

In the description of JP-A-53-21602 proposed by the present applicant, the effect of the binder contained in the layer containing physical development nuclei on printing is described in detail. A synthetic polymer compound applied thereto is disclosed. However, these disclosed plate-making materials are qualitatively satisfactory in terms of photographic characteristics, printability, etc., due to deterioration (softening) of photographic characteristics over time and accompanying reduction in printing power and printing stains. Not satisfactory. An object of the present invention is to provide a lithographic printing plate which has improved these properties, has high sensitivity, has stable photographic properties over time with heating, and has little ink smear in printing.

[0007]

Means for Solving the Problems The present inventors have made intensive efforts to provide such a lithographic printing material, and have arrived at the present invention. That is, in a lithographic printing plate to which a silver complex salt diffusion transfer method is applied, the image receiving layer has a physical development nucleus made of a heavy metal or a sulfide thereof, a functional group having an activity against them, and a functional group having a hydrophilizing activity. And a functional group having a substituted trioxysilyl group in a specific ratio, and a polymer represented by the following formula (4).

[0008]

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In the formula, A is a functional group having an affinity for the physical development nucleus and exhibiting activity, and a 5- or 6-membered heterocyclic ring containing a nitrogen atom is suitable. For example, imidazole, imidazoline, imidazolidin, benzimidazole, imidazolone, imidazolidone, pyrazolidone, pyrrolidone, pyridine, pyrazine, triazole, benztriazole,
Examples include tetrazole, but are not necessarily limited thereto. These heterocycles may have a substituent.

B is a hydrophilic active group such as a hydroxyl group, an amino group, a dimethylamino group, a diethylamino group,
Examples include dipropylamino, methylamino, ethylamino, propylamino, butylamino, acetoxyethylamino, hydroxyethylamino, N, N-dihydroxyethylamino and the like.

The group represented by Y is a functional group commonly known as a silane coupling agent, and R ₆ , R ₇
And R ₈ include a methyl group, an ethyl group, a propyl group, a trimethylsilyl group, a triethylsilyl group, and the like. And the like.

R ₁ , R ₂ and R ₃ are hydrogen, methyl, ethyl, propyl and the like.

X ₁ and X _{2 each} represent —O—,
And other divalent groups, but this group may not be present.

[0014]

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(P is 1 to 5)

[0016]

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L is 1 to 20 mol%, more preferably 2
-10 mol%, n is 0.1-10 mol%, more preferably 0.2-5 mol%, m is (100-ln) mol%
It is. Here, if l is too high, the hydrophilicity is too strong and the ink receptivity of the precipitated silver is reduced, or the miscibility with the colloid particles is reduced. On the other hand, if n is too high, water retention during printing deteriorates, causing stains.

The average degree of polymerization of the polymer used in the present invention is between about 100 and about 3000, preferably about 3
Good between 00 and about 1000. As it deviates from these ranges, the effect of preventing dirt in printing decreases,
Alternatively, any of the above-mentioned disadvantages is likely to occur. When preparing and coating heavy metal sulfide colloidal particles (physical development nuclei), the degree of polymerization of the polymer compound added for the purpose of protecting the colloid, increasing the viscosity, etc. is an important factor.

In another aspect readily imaginable from the present invention,
The polymer can be applied before or after the application of the physical development nucleus, but the method of applying the polymer together with the physical development nucleus is most advantageous from the viewpoint of stability of quality and ease of production. The general level of the polymer that can be used has some dependence on the type, amount, and properties of the colloidal material as a physical development nucleus. The printing characteristics depend on the printing characteristics. On average, is used in an amount of 0.1 g / m ² or less, preferably applied so as to become the amount of 0.001-0.05 grams / m ^2. The production of these polyfunctional polymers can be carried out, for example, according to a conventional vinyl polymerization method. That is, it is obtained by adding a polymerization initiator to a solution of a mixture of three kinds of vinyl monomers and heating, or by keeping a liquid containing the polymerization initiator at a high temperature and dropping the monomer mixture therein. . Many monomers that can be subjected to vinyl polymerization are known (for example, Synthetic Polymer II, published by Asakura Shoten). The polymer of the present invention can be used in combination with the usual water-soluble polymers described in JP-A-54-103104, for example, gelatin, polyvinyl alcohol, hydroxyethyl cellulose, carboxymethyl cellulose and the like.

In the silver complex salt transfer method, usually, the exposed silver halide material is an alkali-bath developing and fixing basically composed of a developing agent, its preservative and a solvent of silver halide. Treated with the composition liquid. According to the general concept of the silver complex diffusion transfer process, the silver halide grains which can be developed by exposure are reduced (reversed in the case of a direct positive type silver halide photosensitive material) by reduction in the composition solution. Is immediately reduced by an agent (developing agent component) to form metallic silver (chemical development). On the other hand, silver halide particles that have not been exposed are hardly subjected to direct reduction, and the silver halide solvent in the composition solution is not easily exposed. For example, thiosulfate, thiocyanate, amines, etc. are once complexed and dissolved, diffused, and reduced around the physical development nucleus surface as a reduction catalyst (physical development). Here, it is natural that the silver halide solvent acts on the silver halide grains that can be developed by exposure, and therefore, the technology of the silver complex salt diffusion transfer method is not a problem. One point is likely to be the balance between the chemical development rate and the physical development rate, including the dissolution process.

It is known that a part or all of the developing agent in a general photographic light-sensitive silver halide material is incorporated in the light-sensitive material. Things become possible.

The developing agents used here include, for example, the following. Hydroxybenzene-based developing agents such as hydroquinone, catechol and pyrogallol and derivatives thereof, such as methylhydroquinone, dimethylhydroquinone, chlorohydroquinone, 4-methylcatechol, 4-ethylcatechol, 4-t-butylcatechol, gallic acid, and gallic acid Methyl ester, gallic acid ethyl ester and the like, and para-aminophenol and its derivatives such as N-methylpara-aminophenol,
4-diaminophenol sulfate or 1-phenyl-
3-pyrazolidone, 1-phenyl-4-methyl-3-pyrazolidone and the like. These developing agents are added after being dissolved in an aqueous solution thereof or a water-miscible organic solvent such as methanol, ethanol, propyl alcohol, acetone or ethylene glycol. Preferably, it is applied together with a liquid containing a heavy metal or a sulfide colloid thereof.

The amount of the necessary developing agent to be added is, for example, from 0.02 g / m ² to 1.0 g of hydroquinone.
/ M ² , and for 1-phenyl-3-pyrazolidone,
An amount of 0.001 g / m ² to 0.1 g / m ² is sufficient. The effect known from this is that not only the printing stain is remarkably improved, but also the photographic and printing characteristics are high contrast,
A photosensitive material having high image sharpness, good resolution, and little change in characteristics over time is obtained.

The present invention also relates to a lithographic printing plate to which a silver complex salt diffusion transfer method is applied, wherein a specific polymer is contained in an image receiving layer thereof. It is not limited by the silver halide emulsion layer, the silver complex salt diffusion transfer treatment, or the like. Next, a polymer having a polyfunctional group according to the present invention will be exemplified.
It is not limited by these.

[0025]

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[0026]

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[0027]

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[0028]

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[0029]

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[0030]

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[0031]

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[0032]

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[0033]

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[0034]

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[0035]

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[0036]

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[0037]

EXAMPLES (I) Synthesis of Polymer Synthesis Example (i) (Exemplified Polymer, Chemical Formula 7) 6.40 g of acrylamide in a flask under a nitrogen stream.
(0.090 mol), 1-vinylimidazole 0.47
g (0.005 mol) and 1.24 g (0.005 mol) of 3-trimethoxysilylpropyl methacrylate are dissolved in 70 ml of tetrahydrofuran and kept at 50 ° C. Under stirring, 0.25 g of 2,2′-azobis (2,4-dimethylvaleronitrile) (Wako Pure Chemical Industries, Ltd. V-65) is added, and after stirring for 2 hours, the precipitate is collected by filtration. Tetrahydrofuran 100
Wash several times with ml and filter. 7.34 g (88
%) As a white powder. Water soluble polymer with average molecular weight of about 30,000 (Tosoh GPC, HLC-8
020 PEG conversion). In the same manner, Exemplified Polymerization 8 shown in Table 1 below was synthesized.

[0038] A ′ = 1-vinylimidazole B ′ = acrylamide Y ′ = 3-trimethoxysilylpropyl methacrylate

[0039]

[Table 1]

Synthesis example (ii) 1-vinylimidazole in the above synthesis example (i) was replaced with 4
-Synthesized similarly in place of vinyl pyridine to synthesize exemplified polymers 11 and 12 shown in Table 2 below.

[0041]

[Table 2]

Synthesis Example (iii) A ′ = 2-methyl-1-vinylimidazole B ′ = acrylamide Y ′ = 3-triethoxysilylpropyl methacrylate The exemplified polymerized compounds 15 and 16 shown below were synthesized.

[0043]

[Table 3]

Further, as a comparative polymer,
Compounds 0, 21, and 22 were synthesized in the same manner as in Synthesis Example (i).

[0045]

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[0046]

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[0047]

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[0048]

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(II) Preparation of lithographic printing plate After corona discharge machining of 135 g / m ² polyethylene-coated paper, a gelatin solution containing carbon black was applied,
Further, an ortho-sensitized high-contrast silver halide emulsion was coated thereon. This emulsion layer was basically composed of 1.5 g of silver halide as silver nitrate and 1.5 g of gelatin per square meter, and contained formalin and dimethylol urea as hardeners. After heating the photosensitive silver halide photographic material at 40 ° C. for 3 days, a coating solution containing a physical development nucleus having the following formulation and the polymer of the present invention was prepared and coated.

(1) Preparation of palladium sulfide sol Liquid A 5 g palladium chloride Hydrochloric acid 40 ml Water 1000 ml Liquid B Liquid sulfide 8.6 g water 1000 ml Liquid A and liquid B were mixed with stirring, and after 30 minutes, ion exchange resin (IR) -120E, IRA-400) to obtain a palladium sulfide sol.

(2) Preparation of Physical Development Nucleus Coating Solution Containing the Polymer of the Present Invention 100 ml of the above-mentioned palladium sulfide sol 100 g of hydroquinone 2 g of the polymer of the present invention 2 ml of 10% saponin (surfactant) 2 ml of water are added to make a total volume of 2 l. A lithographic printing plate was prepared by applying the main coating solution on the silver halide photosensitive material obtained as described above.

(III) Processing Method After exposing the photosensitive material according to an image, the photosensitive material is immersed in a transfer developer (C) of the following formulation at 30 ° C. for 30 seconds to perform transfer development. In stop solution consisting of 3
The material was immersed for 0 seconds (25 ° C.) and squeezed to remove excess liquid, and the material was dried under atmospheric conditions.

Formulation C Transfer developer Water 1500 ml Sodium hydroxide 20 g Sodium sulfite 100 g Hydroquinone 12 g 1-phenyl-3-pyrazolidone 1 g Sodium thiosulfate 10 g Potassium thiocyanate 5 g Potassium bromide 5 g Water is added to make a total volume of 2 L.

Formulation D Stop solution Water 2 l Citric acid 10 g Sodium citrate 35 g

(IV) Printing method The printing plate thus obtained is used for an offset printing machine AB Dick 350CD (AB Dick 350CD).
(Trade name), and after wiping the plate surface with a liquid of formula (E), printing was performed. The printing room was at 22 ° C. and 60% humidity.

Formulation E Water 400 ml Citric acid 1 g Sodium citrate 3.5 g 2-mercapto-5-heptyl-1,3,5 oxadiazole 0.5 g Ethylene glycol 50 ml As a wetting liquid, a commercially available dampening water is used. The printing ink used was F Nippon Ink B manufactured by Dainippon Ink and F Gloss Blue Indigo. F-gloss blue indigo is one of the inks that tends to smear on the offset printing plate.

(V) Evaluation of photographic properties The plate-making material obtained as described above was exposed through an optical wedge, and the plate material developed and processed was subjected to reflection density measurement using an ordinary optical densitometer, and the sensitivity (S ) And tone (gamma γ). The sensitivity (S) was shown as a relative value, with the value of fresh comparative polymerization 19, 20 and 21 as 100. The fresh plate was heated at 50 ° C. for 4 days in order to examine the deterioration due to the heat storage. Thereafter, the same processing was performed, and the sensitivity (S ′) and the tone (γ ′) after the heating processing were obtained. Table 4 shows the results.

[0058]

[Table 4]

From the results shown in Table 4, the polymer of the present invention obtained by copolymerizing the monomer containing the substituent Y has higher sensitivity than the comparative polymer not containing the same, and is softened by heat treatment. No, it is stable to heat.

(VI) Evaluation of Printing Characteristics Next, the plate material obtained as described above was printed by the above-described offset printing machine according to a predetermined process. The printing characteristics were evaluated based on the degree of smearing of the printed matter, and evaluated according to the following five levels. 5: There is almost no dirt. 4 ... There is a slight dirt in the middle of 5 and 3. 3 ... Partially thin stains occur. 2. There is a dirt in the middle between 3 and 1. 1: Thin dirt is generated on the entire surface. Table 5 shows the results.

[0061]

[Table 5]

From the results shown in Table 5, the degree of occurrence of print smear is equal to or less than that of the comparative polymer, and the printing characteristics show stable printing characteristics even with the heat treatment.

[0063]

As is clear from the examples, the polymer compound shown in the present invention is a novel polymer useful as a binder resin in the production of a lithographic printing plate to which a silver complex salt diffusion transfer method is applied. From the results shown in Tables 4 and 5, the polymer having a silyl group-containing functional group of the present invention has excellent storage stability and high sensitivity of a printing plate using the polymer, as compared with the conventional polymer.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-53-21602 (JP, A) JP-A-55-96955 (JP, A) JP-A-59-201898 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) G03F ^7/ 00-7/42

Claims (1)

(57) [Claims] A lithographic printing plate comprising a photographic photosensitive layer mainly composed of a silver halide emulsion on a support and a layer containing physical development nuclei on a lithographic printing plate using a silver complex salt diffusion transfer method. A lithographic printing plate comprising Chemical Formula 1 as a binder in a layer containing a nucleus. Embedded image Wherein R1, R2 and R3 are hydrogen or a lower alkyl group, A is a nitrogen-containing heterocyclic group, B is a hydroxyl group or
Represents chemical formula 3. X1 and X2 are divalent linking groups and may not be present. l is 1 to 20 mol%, n is 0.1
-10 mol%, and m represents (100-ln) mol%] (R4 and R5 each represent hydrogen or a lower alkyl group which may have a substituent) (R6, R7 and R8 are lower alkyl groups and substituted silyl groups)