JPS59168449A - Photosensitive lithographic plate improved in safelight safety - Google Patents

Abstract

PURPOSE:To obtain the titled plate without increasing a load in a film dissolving step by forming a photosensitive silver halide emulsion layer contg. a negative photosensitive silver halide and a specified desensitizing dye on a support having a hydrophilic surface. CONSTITUTION:A support, such as an aluminum plate, having a hydrophilic surface is coated with a 0.1-5g/m<2> photopolymerizable compsn. composed of an addition-polymerizable unsatd. compd. and a photopolymn. initiator and dried to form a photosensitive nonsilver layer capable of forming an oleophilic image. A photosensitive silver halide emulsion layer is formed by coating this layer with a photosensitive silver halide emulsion contg. negative photosensitive silver halide sensitized up to 560nm wavelength and having 0.01-5mum average grain diameter, and a desensitizing dye having absorption on the side of wavelengths longer than the intrinsic wavelength of this silver halide, and its main absorption in 560-680nm. wavelengths, such as comps. of formulae I and II in an amt. of 1-10g/m<2>, and drying this emulsion.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a high-sensitivity photosensitive lithographic printing plate using a silver halide emulsion layer, which has significantly improved safety against yellowing and red safelight. It relates to lithographic printing plates, and in particular to photosensitive lithographic printing plates that have high sensitivity and are improved in safety so that they can be worked under yellow or red safelights.

Conventionally, the 28th edition (Pre
Sensitized Plate) is, for example, Japanese Patent Publication No. 44-27242, Japanese Patent Publication No. 16725-1982, Japanese Patent Publication No. 30562-1982, U.S. Patent No. 4221858, U.S. Patent No. 4173477, U.S. Pat.
61508, 3721559 and 5,14
6,104, etc.

Furthermore, as the 28th edition that improved them, for example,
6-26521, Japanese Patent Application Publication No. 54.27804, West German Patent Publication (OLS) No. 2517711, OLS No. 2640766
The number etc. are known. Furthermore, further improved PS versions are known, such as US Pat. In addition, in order to improve printing durability, oil sensitivity, and image reproducibility, a non-silver photosensitive layer is provided on the hydrophilic aluminum support, and a photosensitive layer containing silver halide is directly applied on top of the non-silver photosensitive layer. The PS version created is US Patent No. 42686.
No. 09, No. 4299912, etc.17).

PS plates using these photosensitive silver halides have high sensitivity, but on the other hand, when exposed to light in the photosensitive wavelength range of the silver halide photosensitive layer during plate-making work before development, fogging may occur, and the above-mentioned problems may occur. The sensitivity is 1 compared to the sensitivity of the photosensitive wavelength range.
/10 or less, so there is virtually no sensitivity, and even light in the longer wavelength photosensitive range causes sensitization due to the sub-exposure effect, so it has the disadvantage of having to be handled under a dark yellow or red safelight. there were.

As a method of overcoming this drawback, it is generally used in film recording materials to provide a single filter layer on the silver halide photosensitive layer for cutting off long wavelength light that produces a sub-exposure effect. However, providing a single filter layer is not preferable because it not only complicates the manufacturing process but also increases manufacturing costs. Furthermore, for example, JP-A-55-
In the composite PS plate shown in No. 166645, the presence of one filter increases the burden of the leaching process, and often causes defective leaching.

Therefore, an object of the present invention is to provide a photosensitive lithographic printing plate with improved safety against safelight without complicating the layer structure and, in the case of composite PS plates, without increasing the burden of the leaching process. It's about doing.

The inventors of the present invention have conducted various studies in view of the above circumstances, and have found that a photosensitive silver halide emulsion layer or a non-silver photosensitive layer capable of forming a lipophilic image on a support having a hydrophilic surface has been developed. A photosensitive lithographic printing plate having a photosensitive silver halide emulsion layer provided in this order is coated with a negative light-sensitive silver halide emulsion layer and a light-sensitive silver halide emulsion layer having an absorption on the longer wavelength side than the characteristic wavelength of the silver halide emulsion layer. It has been found that the above object can be achieved by coexisting a sensitive dye.

According to the preferred embodiment of the present invention, the silver halide is usually sensitized to 560 nm.

A desensitizing dye coexisting therewith has main absorption at 560 nm to 680 nm, and a photosensitive lithographic printing plate with improved safety against yellow to red safelight is provided.

A feature of the present invention is that the photosensitive silver halide emulsion layer contains, together with negative-working silver halide, a dye that has absorption at a wavelength longer than the intrinsic sensitivity wavelength of the 710 silver halide and exhibits desensitization properties. The goal is to coexist.

The present invention will be explained in detail below.

Desensitization in the present invention means that the image forming sensitivity of a lithographic printing material to which a desensitizing dye has been added is 1 ogE (where E indicates the exposure amount) compared to the sensitivity of the same lithographic printing material except that no desensitizing dye has been added. 0.02-1 preferably 0.05-0
．． 4. This refers to a feeling of low sensation, which can be confirmed by the method described in Example-1.

The desensitizing dye used in the present invention is from s6onm to 680n.
Dyes having main absorption in m are used, and preferred dyes are selected from triphenylmethanes, anthraquinones, azos, oquinoles, pyrazolone azomethines, indophenols, phthalocyanines, and the like. Various types of desensitizing dyes of this kind have been known in the past, and these can be suitably used in the present invention, but particularly preferred specific examples will be given below. Of course, it is not limited to this.

1. Orient Solving - 0BB (Orient) λmax 61 [] nm 2. Patent Blue AFX (Hoechst) λmax
x 656nm 6, Lionol Blue GSF-1 (Toyo Ink Manufacturing) λmax 667.666nm 4, Suminol Royering Blue AGG (Sumitomo Chemical) λmax λmax 612nm 8゜λmax 617nm /ゝCH2CH2CH25o3K) These dyes in i3 are as described above. The purpose of this is to prevent the influence of the sub-exposure effect of photosensitive silver halogenide, so if the above object cannot be achieved alone, two or more types of dyes are used in combination. If a negative light-sensitive silver halide emulsion is specified, the amount of these dyes to be added can be easily determined by simple experiments.

Next, the photosensitive lithographic printing component of the present invention will be explained. The support used in the present invention has a hydrophilic surface and may be any support used as a lithographic printing plate at °C, but particularly preferred is an aluminum plate, the surface of which is grained. For example, surface treatment such as chemical conversion treatment using an aqueous solution of sodium silicate, potassium fluorozirconate, or phosphate, or oxidation treatment is preferably performed.

A photosensitive lithographic printing plate (Pre-8
It is called the Ensitized Plate and is abbreviated as the 28th edition. ) includes a suitable photosensitive layer. Here, the above-mentioned "oleophilicity" refers to the property of repelling dampening water used during printing and accepting oil-based ink. Specific compositions of such a non-silver photosensitive layer include those consisting of a diazo resin, those consisting of a 〇-quinonediazide compound, those consisting of a photosensitive azide compound, and those containing -CH= in the main chain or side chain of the polymer. , those made of polymeric compounds containing CH-C- groups, and photopolymerizable compositions made of addition-polymerizable unsaturated compounds and photoinitiators, all of which are well-known compositions in this field. be. Further details of these compositions are described, for example, in US Pat. No. 4,299,912. These compositions are coated onto a support from a solution in a suitable solvent and provided at a dry weight of about 0.1 y/m to about 5 y/m.

The silver halide-containing photosensitive layer used in the present invention is
Those described in JP-A-5-166645, JP-A-56-14269 and JP-A-56-50330 are used. The photosensitive 710 silver halide emulsion is a negative type emulsion, and silver chloride, silver bromide, silver iodide, or a mixed silver halide thereof can be used.The average grain size is 0. A diameter of .01 to 5μ is preferred.

The particles may be sensitized by e.g. sulfur to achieve appropriate sensitivity.
Chemical sensitization such as reduction sensitization, sensitization with salts of noble metals such as Rh, Rh, and Pt, and spectral sensitization using sensitizing dyes can be performed. Any particle having a surface latent image type or internal latent image type latent image distribution may be used. Commonly used additives can be added to this.

It is preferable that the photosensitive silver halide emulsion contains an oil-like, wax-like, or resin-like lipophilic compound dispersed in the form of fine particles. , No. 609.

These light-sensitive silver halide emulsion layers have a density of about 1 to 10
It can be applied in a dry amount of y/i preferably from 2 to 6 y/m. Application is done by dip, air knife,
Coating methods such as curtains also e.g. U.S. Pat. No. 2,681
, 7ξ-coating method and extrusion coating method described in No. 294 can be applied.

The method and process for making a lithographic printing plate using the photosensitive lithographic printing plate according to the present invention are as follows. First, imagewise exposure is performed to form a latent image on the silver halide in the photosensitive layer containing silver halide. Next, the silver halide is developed (first development), and then exposed to active light including ultraviolet rays through a process of treatment with a fixing solution, and then the gelatin silver halide emulsion layer is washed out. After that, the support is sent to a second development stage where only the non-image areas of the non-silver photosensitive layer are dissolved and removed to expose the hydrophilic surface of the support to obtain a printing plate.

In this case, the processing solution used for the second development needs to be such that it selectively dissolves only the non-image areas of the non-silver photosensitive layer, and is particularly suitable for developing the 28 plate which has a normal non-silver photosensitive layer. The developer can be selected from among the developer solutions listed above or similar developers. For example, when the non-silver photosensitive layer is a layer made of an 0-quinonediazide compound, an aqueous solution of sodium silicate or a developer as described in US Pat. No. 4,141,733 is used.

The content of the present invention will be explained in detail below using Examples.

Note that ``chi'' indicates weight %.

Example 1゜A 2S material aluminum plate mechanically grained by the method of JP-A No. 48-43911 was heated to 2% at 40°C.
It was immersed in an aqueous sodium hydroxide solution for 1 minute to corrode a part of the surface. After washing with water, it was immersed in a sulfuric acid-chromic acid solution for about 1 minute to expose the pure aluminum surface. Immersed in 20% sulfuric acid kept at 60°C, current voltage 1.5V, current density 3
After anodizing for 2 minutes under the condition of ``A/drn'', it was washed with water and dried.Next, a photosensitive solution with the following composition was continuously applied using an extrusion type Giesser so that the dry weight was about 21y. I applied the coating.

Naphthoquinone-1,2-diazide(2)-5-sulfonic acid ester of acetone-pyrogallol resin (synthesis method is according to the method of Example 1 of US Pat. No. 3,635,709)...2.5'iP Cresol formaldehyde resin...5.0? Methyl ethyl ketone...75y-cyclohexanone...6C1 Separate silver iodobromide emulsions were prepared as follows.

A silver bromide emulsion with an average grain size of 0.25 μm was obtained by adding a silver nitrate aqueous solution and a potassium bromide aqueous solution to an aqueous gelatin solution kept at 50° C. while stirring simultaneously for 50 minutes, and controlling the pAg at 79 during that time. . After removing soluble salts by a conventional method, this emulsion was prepared with 46 mg/mole of silver bromide.
RV sodium thiosulfate was added and chemically aged at 60°C for 60 minutes. Next, potassium iodide in an amount equivalent to 0.4 molty was added to obtain a silver iodobromide emulsion. This emulsion is enriched with 701 gelatin per mole of silver iodobromide and 1.8 per KfI of emulsion.
It contained 5 moles of silver iodobromide.

Ethyl acetate 660?459 of phenol formaldehyde resin MP120HH (Gunei Chemical Industry ■) and methyl ethyl lactone 120y- dissolved in a mixture of gelatin 1
An emulsion prepared by dispersing a solution of 10% sodium nonylbenzenesulfonate solution mixed with 15.0% of a 10% methanol solution of funnel oil in 60yd of an aqueous solution.
・-13005' 0.1 timethanol solution of 1.6-dinityl-5-C2-(3-(3-sulfopropyl)benzoxazol-2-ylidene)ethylidene]thiohydantoin sodium salt...100ml 4-hydroxy- 6-methyl-1,3,3a.

7 - 0.5% alkaline aqueous solution of chitrazaindene...
Sample P was obtained by coating on the 200-light layer so that the dry weight was 4y/g and drying with hot air at a final temperature of 110°C.

Further, finished emulsion B obtained by adding 90 ml of a 2-water solution of Orienton Lupul Blue (manufactured by Orient Co., Ltd.) to the finished emulsion A was coated and dried on the non-silver photosensitive layer in the same manner as A, and a sample was prepared. I got Q.

After samples P and Q were left at room temperature for one week, a step wedge for sensitometry was photographed, and then the following processing was performed using an automatic processor. Developing solution (1) with the following composition was heated at 62℃ for 20 minutes.
After passing for a second, fixer solution (1) with the following composition was added for 10 minutes at room temperature.
It lasts for seconds. Next, an ultraviolet exposure section consisting of three reflector-type mercury lamps was applied for 15 seconds, and the washing section
Soak in ~45°C warm water, remove with a brush, use a squeeze roller, and then use a developer (If) with the following composition at 60°C for 30 minutes.
Gum coater 800 manufactured by Fuji Photo Film ■
Using G, a FP coating plate was obtained.

Composition water of developer (1) -700
1nl metol...6,
Oy-Sodium sulfite...45
．． O? Hydroquinone...12
．． 0y-Sodium carbonate (monohydrate)...8[
3, [3? Potassium bromide...
2. This stock solution, made up to 1 t by adding P water, is diluted with water (1:2') and used.

Developer (If) J Engineering S1 Sodium silicate...100y-sodium metasilicate...5(1) Pure water...-180[]y Fixer (
1) Water -700
ml ammonium thiosulfate...224f
! - Sodium sulfite... 21 Add water to... 1000 ml of sample P
, when comparing the printing plates obtained from Q, Q is P 1) 1ag
A desensitization of 0.1 in E (logarithm of exposure amount) was observed.

Therefore, the 1,6 diethyl-5-[2-(
0.3-sulfopropyl)penzoxazole-2-ylidene)ethylidenecothiohydantoin sodium salt.
Emulsion C, which corrected this desensitization by increasing the amount of 1% methanol solution to 200 -, was coated on the non-silver sensitive layer in the same manner as emulsions A and B.

Sample R was obtained by drying.

After leaving the sample R at the same temperature for one week, it was cut into 1/2 pieces and designated as R1 and R2, respectively. At the same time, the sample P is also cut into 1/2 and designated as pl and p2. These four samples were made into plates as follows.

Pl and R1 are orange-yellow safelight light that cuts out light with wavelengths as short as 560 nm (using one S2C safelight made by Fuji Film ■ to cut out light with wavelengths as short as 560 nm) and an illuminance of 20 lux. The entire surface was exposed to light for 60 minutes.

Sample P2 which was not exposed to safelight light after this. R
Sample p1. Exposure was carried out at p2°R1 and R2, respectively. Next, using an automatic processor, the same treatment as the sample Q was applied to produce four printing plates P1, P2.
R1 and R2 were obtained.

These four printing plates were printed using a Heidel KOR printing machine, and the image quality of the printed matter was examined. A non-silver photosensitive layer was provided in accordance with Example 1, and the following finished emulsion C was added thereon to a dry weight of 4'i.
/m”.

Phenol formaldehyde resin M p-120HH (
451 (manufactured by Gunei Chemical Industry ■) and dioctyl adipate were dissolved in a mixture of ethyl acetate 660y'' and methyl ethyl ketone 1201 to make a 10% gelatin aqueous solution 60 Ome.
Inside, 10ql of sodium nonylbenzenesulfonate
) 60% solution of 10% methanol solution of funnel oil
Emulsion dispersed in a solution mixed with 50ml
...130 (silver chlorobromide gelatin emulsion (Ct
-70 mol%, Br-60 mol of silver chlorobromide, average grain size...0.28μ emulsion l Ky, comb gelatin 55
? Contains 085 moles of silver halide)...
...20005'1.3-tethyl-5-[2-(3
-(3-sulfopropyl)benzoxazol-2-ylidene)ethylidenecothiohydantoin sodium salt 0.1% methanol solution 10
0rnl.

0.5 aqueous alkaline solution of 4-hydroxy-6-methyl-1,3z3aj7-chitrazaindene...2
001n1 2% aqueous solution of 2.4"-dichloro-6-hydroxy-8-triazine...70d Dry with hot air at a final temperature of 110°C to obtain sample S. Also, sample S was obtained from the emulsion 1 and 3 of the above emulsion. - The amount of 0.1% methanol solution of diethyl-5-[2-13-(S-sulfopropyl)benzoxazol-2-ylidene)ethylidene cothiohydantoin sodium salt was increased to 200 μg, and Suminol Royering Plug AGG (manufactured by Sumitomo Chemical) 1% aqueous solution
A finished emulsion E obtained by adding ...90- was coated on a non-silver photosensitive layer in the same manner as D and dried to obtain sample T.

After leaving samples S and T at room temperature for one week, each material was cut into 1/2 pieces and 81. S2. Let TI be T2. These two pairs of materials were made into plates according to Example 1 as follows.

si and 'ri were completely exposed to orange safelight light, which cuts out light with a wavelength shorter than 560°C, at an illuminance of 20 flex for 60 minutes. After this, document 82 that is not illuminated by safelight light. A transparent negative film obtained by reducing the size to about 115 with T2 and photographing the character lines was enlarged 5 times using an enlarger with a 600 lux light source for 10 seconds as a test sample 1. s2, T1. Each was exposed to T2. Next, the same development treatment as in Example 1 was performed to obtain a printing plate.

When these four printing plates were printed using an Idel KOR printing machine and the image quality of the printed matter was examined, the following results were obtained.

Claims (1)

[Claims] 1) A photosensitive silver halide emulsion layer or a non-silver photosensitive layer capable of forming a lipophilic image and a photosensitive silver halide emulsion layer on a support having a hydrophilic surface in this order. In the photosensitive lithographic printing plate comprising the negative photosensitive silver halide, a desensitizing dye having absorption at a wavelength longer than the intrinsic sensitivity wavelength of the silver halide is co-presented. A photosensitive lithographic printing plate with improved safety against safelight with wavelengths longer than the specific photosensitive wavelength of . 2) The silver halide is sensitized to at most about 560 nm, and the desensitizing dye coexisting with the silver halide is sensitized to about 560 nm.
The photosensitive lithographic printing plate according to claim 1, which has improved safety against safelight of yellow to red light having main absorption in the wavelength range of m to 680 nm.