JPS6350833A - Image forming method - Google Patents

Abstract

PURPOSE:To rapidly and stably obtain an image having superior dot quality by imagewise exposing a photosensitive material contg. a specified compd. in the photographic silver halide emulsion and by processing the material with a specified developing soln. CONSTITUTION:A silver halide photographic sensitive material contg. a compd. represented by formula I (where each of R1 and R2 is H, halogen, alkyl or the like) in the negative type fine-grain silver halide emulsion contg. at least 80mol% silver chloride is imagewise exposed and processed with a developing soln. contg. 0.05-0.5mol/l dihydroxybenzene developing agent, >=0.25mol/l free sulfite ions, >=20mg/l 5- or 6-nitroindazole and an alkali agent enough to adjust the pH to >=10.5. The developing soln. does not practically contain an auxiliary developing agent. Thus, a silver image having superior dot quality can be rapidly obtd. The image can be stably used over a long period.

Description

Detailed Description of the Invention (A> Industrial Application Field The present invention relates to an image forming method, and more specifically to a silver halide photographic light-sensitive material that can be handled substantially under conditions called a bright room. This invention relates to an image forming method for obtaining an image with excellent halftone dot quality in a printing plate making process using a printing process.

(B) Prior art and its problems In recent years, in the printing field, due to the complexity of printed matter and the development of scanners, there has been a demand for improved efficiency in the turning process. For this reason, a photographic film with an ultra-low density of about 10-3 to 10-5 has been developed compared to the conventional film for return, which can be handled in a bright room (under white fluorescent light with no ultraviolet rays). It has begun to be put to practical use as a film, that is, a light-sensitive material.

The performance required of such bright room photosensitive materials is that they have high contrast and sufficient maximum density, can be handled for long periods of time in a bright room, and have high sensitivity to ultraviolet light sources. etc. However, it cannot be said that conventional photosensitive materials for use in bright rooms fully satisfy the above-mentioned performance, and there is a desire to develop improved photosensitive materials for use in bright rooms.

As a silver halide emulsion for light-sensitive materials for bright room use, JP-A-5
6-125734, in which a large amount of rhodium is used as an inorganic desensitizer in silver halide mainly composed of silver chloride, or pinacryp, which is commonly used in direct positive silver halide emulsions. It is manufactured by a method using an organic desensitizer such as Tall Yellow.

As described in Japanese Patent Application Laid-open No. 59-177537, in order to improve long-term safety in a bright room,
- It is known to add mercaptobenzoin MX conductors to silver halide or adjacent layers of the emulsion layer.

On the other hand, in recent years, a dihydroxybenzene-based development process and three
- A system (Rapid Access System) using a developer in combination with: - Pyrazolidone-based developer has been put into practical use, and is published in Japanese Patent Application Laid-Open No. 60-95538.58-19094.
It is listed in 3rd class. However, with this system it is not possible to obtain a silver image with sufficiently excellent halftone quality.

(C) Object of the Invention The object of the present invention is to quickly and stably provide images with excellent halftone dot quality using a bright room silver halide photographic material that can be safely handled under bright room light. An object of the present invention is to provide an image forming method.

(D) Structure of the invention As a result of extensive research to achieve the above objective, the inventor has
After imagewise exposing a silver halide photographic material containing a compound represented by the following general formula [I] to a negative fine-grain silver halide emulsion containing at least 80 mol% of silver chloride,
(1) Dihydroxybenzene-based developing agent from 0.05 to 0
．． 5 mol/I! (2) substantially free of auxiliary developing agents; (3) free positive sulfite ions of 0.25 mol/l
(4) containing 20 my/l or more of 5- or 6-nitroindazole, and (5) processing with a developer containing an alkaline agent sufficient to raise the pH to 10.5 or more. It has been found that the above objectives are achieved.

General formula CI) (Here, R1 and R2 may be the same or different substituents, and represent hydrogen, a halogen atom, an alkyl group, a carboxyl group, an amino group, or an alkoxy group.) Specific examples of these compounds are shown below. However, the present invention is not limited thereto.

Compound 1 l 13r Sr Compound 5 Br Cfl CH3CH3 C2to15 C2H5 ″8 COOHCOOH Compound 9 COOHCz H5 “ 1O N Hz N Hz 0CH30CH3 “ 12 Ct-f3 These disulfide compounds are silver halide milk It is preferable to add it to the agent. , it may be added to the coating solution of the layer adjacent to the emulsion layer and diffused into the emulsion layer.

The addition period may be any time during the emulsion manufacturing process, and the addition period is generally about 20 m3 to 5 m3 per mole of silver halide.
It can be selected as appropriate within the range of 7.

The silver halide emulsion in the present invention may contain an organic desensitizer generally known for use in direct positive silver halide emulsions. The organic desensitizer referred to herein is characterized by its polarographic half-wave potential, its redox potential determined by polarography. That is, the sum of the polarographic anode potential and the cathode potential is positive.

Methods for measuring these redox potentials are described, for example, in US Pat. No. 3.50'1,307.

Specific examples of such organic desensitizers can be found in numerous patent specifications,
All of them have the same effect in the present invention, and for example,
6-'l 7595, Kaimei 39=20261, Kaimei 40
-26751, Kaimei 43-13167, Kaimei 45-88
33, Kaimei 47-8746, Kaimei 47-10197, Kaimei 50-37530, JP-A-48-24734, Kaimei 4
9-84639, U.S. Pat. No. 56-142525, U.S. Patent No. 2.271.229, U.S. Pat.
Same 3rd. '124,458@, same number 3.326,687
Compounds described in specifications such as @ and No. 3,671,254 can be used.

The silver halide emulsion used in the present invention is a fine-grain silver halide emulsion, preferably having an average grain size of about 0.05 μm to 0.3 μm. In addition, more than 90% of the total number of particles is within ± the average particle size.
Those having a particle size in the 10% range are preferred. The silver halide emulsion may be prepared by any known method such as forward mixing, back mixing, and simultaneous mixing. Rhodium may or may not be included.

The silver halide emulsion obtained according to the present invention can contain various antifoggants. Generally it is benzotriazole, 1-phenyl-5-mercaptotetrazole.

The silver halide emulsion obtained by the present invention contains a covering power improver, an irradiation inhibitor, a film property improver,
It can contain additives used in general photographic emulsions such as surfactants, hardeners, matting agents, developing agents, etc., and is coated on a known support. It may have other hydrophilic colloid layers such as a protective layer and an undercoat layer.

The light-sensitive photosensitive material obtained according to the present invention is exposed to light using a light source rich in ultraviolet light mainly used in the printing field, such as a mercury lamp, an ultra-high pressure mercury lamp, a metal halide, and the like.

The aqueous alkaline developer used in the present invention (1) contains 0.05 to 0.5 mol/l of a dihydroxybenzene-based developing agent, (2) contains substantially no auxiliary developing agent, and (3) contains free Contains 0.25 mol/liter or more of sulfite ions, (4
) 5- or 6-nitroindazole at 20 m'J/I!
and (5) contains an alkaline agent in an amount sufficient to adjust the pH to 10.5 or higher.

Examples of dihydroxybenzene-based developing agents include hydroquinone, chlorohydroquinone, bromohydroquinone, isopropylhydroquinone, toluhydrohydroquinone, methylhydroquinone, 2,3-dichlorohydroquinone, and 2,5 dimethylhydroquinone.

The aqueous alkaline developer in the present invention contains a sulfite preservative for the purpose of preserving the developer from air oxidation.

For example, sodium sulfite, potassium sulfite, potassium metabisulfite, sodium bisulfite, etc. are added. The preferred amount added is 0.25 to 1.00 mol/! It is.

The aqueous alkaline developer in the present invention is 5- or 6-
- Contains nitroindazole. The preferred addition amount is 20m
g/I! That's all.

The aqueous alkaline developer in the present invention has D+-('2
Contains potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, sodium acetate, potassium triphosphate, etc. for adjustment.

The preferred pH is 10.5 or higher.

The aqueous alkaline developer in the present invention is used to minimize fog formation and to provide desirable photographic properties by 1q.
Contains necessary organic antifoggants for the purpose of Benzotriazole, 6-nitrobenzimidazole nitrate, 5-
Methylbenzo l-lyazole, 1-phenyl-2-tetrazoline-5-thione, 5-phenyltetrazole, 1
-Phenyl-5-mercaptotetrazole and the like are common, and 5-methylbenzotriazole is preferred.

The aqueous alkaline developer in the present invention includes ascorbic acid,
It can contain antioxidants such as jetanolamine and kojic acid, water softeners such as nitrilotriacetic acid and ethylenediaminetetraacetic acid, polyalkylene oxides, amino compounds, triethylene glycol, methanol and the like.

The image forming method of the present invention makes it possible to quickly obtain a silver image with excellent halftone dot quality required in the printing process,
Moreover, it has the advantage that it can be used stably for a long period of time.

(E) Examples Example 1 Silver halide was precipitated in a conventional manner using 100 mg of adenine and 10 −5 mol of rhodium per 1 mol of silver chlorobromide containing 95 mol % of silver chloride, followed by physical ripening. 19 to produce an emulsion with an average grain size of 0.1 mm and a narrow grain size distribution. After desalting and redissolving this emulsion, Pinacryptol Yellow was added as an organic desensitizer at a concentration of 50% per mole of silver halide.
0 mg, further added a hardening agent and a surfactant, and coated on a polyester film with a gelatin solution for a protective layer so that the silver ratio was 3.59/edge, and dried (blank sample).
.

This is designated as sample A.

Roughly, the above emulsion contains a compound exemplified by general formula (1) (
1) was added in an amount of 50 mg per 1 mole of ui, coated on a film in the same manner, and dried. This is designated as sample B.

Samples A and B were subjected to sensitometry using a Meishi printer, processed using two types of developing solutions shown in Table 1 at 38 degrees Celsius for 20 seconds, fixed, and dried.

Table 1 Developer Formula In Table 1, Processing Solution B is the developer of the present invention, and Processing Solution A is the developer of the present invention except for 5-nitroindazole.

The evaluation results are shown in Table 2.

In Table 2, the halftone dot quality is expressed in five levels, with 5 being the best. From this table, it can be seen that high quality halftone dots can be obtained only when the photosensitive material of the present invention and the processing liquid are combined.

Therefore, it can be seen that the image forming method of the present invention is extremely useful in achieving the excellent halftone dot quality required in the printing process.

Example 2 An emulsion was prepared in the same manner as in Example 1, and further, compounds (1) to (12) exemplified by general formula [I] were added in an amount of 50 m'j per mole of silver, and applied to a film. Dry film 1-12). Twelve types of films were subjected to sensitometry using a bright room printer, developed using processing solution B at 38°C for 20 seconds, fixed, and dried. The results are shown in Table 3.

(The following is a blank space) Table 3 From this table, it can be said that the compound and image forming method of the present invention are extremely useful methods for obtaining excellent halftone dot quality using a stable developer.

Claims (5)

[Claims] (1) After imagewise exposing a silver halide photographic light-sensitive material containing a compound represented by the following general formula [I] to a negative fine-grain silver halide photographic emulsion containing at least 80 mol % of silver chloride, (1) dihydroxybenzene-based 0.0 developing agent
Contains 5 to 0.5 mol/l, (2) does not substantially contain an auxiliary developing agent; (3) Contains 0.25 mol/l or more of free sulfite ions, (4) 20 mg/l of 5- or 6-nitroindazole
Contains more than (5) An image forming method characterized by processing with a developer containing an alkaline agent in an amount sufficient to adjust the pH to 10.5 or higher. General formula [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (Here, R_1 and R_2 may be the same or different substituents, and represent hydrogen, halogen atom, alkyl group, carboxyl group, amino group, or alkoxy group. .)