JPS6214144A - Silver halide photographic sensitive material - Google Patents

Abstract

PURPOSE:To improve the stability of the titled material in handling at a daylight room by incorporating at least one sort of 4-mercaptobenzoic acid to a silver halide emulsion layer or its adjacent layer. CONSTITUTION:The titled material comprises at least one kind of 4- mercaptobenzoic acid to the silver halide emulsion layer or its adjacent layer in the titled material which is suitable to use at the daylight room, and is incorporated a desensitizer to the negative type fine particle silver halide emulsion contg. at least 80mol% silver chloride in the silver halide emulsion layer provided on a substrate. The usable 4-mercaptobenzoic acid is comprised for example, the substituents of 4-mercaptobenzoic acid substd. by an alkyl, an alkoxy, an amino, an acylamino group and a halogen atom, and its substituent contg. a protective group capable of forming a mercapto group, in addition or 4- mercaptobenzoic acid. Thus, the prescribed silver halide photographic sensitive material is maintained the stability during a storage, under the light of the daylight room which is not removed an UV ray. Even if the titled material is used after storing for a long period, said material may be safely handled under the light of the daylight room.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Industrial Application Field The present invention relates to a silver halide photographic light-sensitive material, and more particularly to a silver halide photographic light-sensitive material suitable as a light-sensitive material for bright room use.

(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 purpose, a photographic film with an ultra-low sensitivity of about 10-3 to 10-5 has been developed compared to the conventional film for turning. It has begun to be put to practical use as a photosensitive material.

The performance required of such a photosensitive material for bright room use is that it has high contrast and sufficient maximum density, and has a sharp photographic characteristic curve.
It can be used for long periods of time in a bright room and has high sensitivity to printer light sources. However, it cannot be said that the 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 photosensitive materials for bright rooms, JP-A-56-
125734, in which a large amount of rhodium salt is used as an inorganic desensitizer in silver halide containing silver chloride, or the method generally used in direct positive silver halide emulsions. It is manufactured by a method using an organic desensitizer, etc. Japanese Patent Publication No. 59-17753
As described in Publication No. 7, at least one type of 2-mercaptobenzoic acid is added to the silver halide emulsion layer or adjacent to the emulsion layer in order to safely handle it under bright room light for a long time. can be added to the layer. but,
The present inventors have discovered that silver halide light-sensitive materials for bright room use prepared using at least one of an organic desensitizer and a rhodium salt and 2-mercaptobenzoic acids may be used after long-term storage or when exposed to ultraviolet light. When left for a short time in a bright room with no color removed, significant fogging occurred and stability over time was confirmed to be poor. Although it is fine to use the product immediately after manufacture, in reality it takes a long time to use it after manufacture, and in many cases it is stored for a long period of time before being used. In addition, it can be handled in a bright room that removes ultraviolet light, but the prevalence of bright rooms that remove ultraviolet light is low, and it is often handled under commonly used fluorescent lights that contain ultraviolet light. There is a demand for improved handling safety.

(C) Object of the Invention The object of the present invention is to provide a silver halide photographic material for use in a bright room, which is safe under white light and does not remove ultraviolet rays.

(D> Structure of the Invention As a result of repeated research to achieve the above object, the inventors have
A silver halide photographic light-sensitive material for bright room use containing at least one type of desensitizer in a negative fine-grain silver halide emulsion containing at least 80% silver chloride, in which the silver halide emulsion layer or a layer adjacent to the emulsion layer is It has been found that the above object can be achieved by a silver halide photographic material containing at least one type of 4-mercaptobenzoic acid.

In addition to 4-mercaptobenzoic acid, the 4-mercaptobenzoic acids used in the present invention include those in which 4-mercaptobenzoic acid is substituted with a furkyl group, an alkoxy group, an amino group, an acylamino group, a halogen atom, etc. Furthermore, those having a protecting group so as to be able to generate a mercapto group, such as S-acetyl-4-mercaptobenzoic acid, S-
Methylcarbamoyl-4-mercaptobenzoic acid, S-)
Examples include carbamoyl-4-mercaptobenzoic acid. These 4-mercaptobenzoic acids are preferably added to the silver halide emulsion, but may also be added to the coating solution for the layer adjacent to the emulsion layer and diffused into the emulsion layer.

The addition time may be any time during the emulsion manufacturing process, and the amount added is generally 0.02 to 5 g per mole of silver halide.
It can be selected as appropriate within the range.

Of course, other antifoggants or stabilizers can also be used if necessary.

Desensitizers used in the present invention include organic desensitizers and/or
Alternatively, at least one type of water-soluble rhodium salt is used. The organic desensitizer used in the present invention is generally known to be used in direct positive silver halide emulsions. That is, the organic desensitizer used in the present invention is
It is determined by its polarographic half-wave potential, that is, its polarographic potential. It is characterized by its redox potential. Organic desensitizers useful in the present invention are those in which the sum of polarographic anode potential and polarographic cathode potential is positive. Methods for measuring these redox potentials are described, for example, in US Pat. No. 3,501.307.

Many specific examples of such organic desensitizers are described in patent specifications and literature, and all of them have the same effect in the present invention. For example,
Special Publications 17595-1970, 20261-1970, 26751-1970, 13167-1970, 13167-1970, 1972-
8833, 1974-8746, 1974-10197
, No. 50-37530, JP-A-48-24734, JP-A-49-84639, JP-A-56-142525, U.S. Patent Nos. 2,271,229, 2,541.472, 3.035 , No. 917, No. 3.062,651
No. 3,124,458, No. 3,326,68
Compounds described in specifications such as No. 7, No. 3,671°254 can be used.

Examples of the desensitizer used in the present invention are shown below, but the desensitizer is not limited thereto.

(D-1) 1,3-diethyl-lower-methyl-2'-
Phenylimidazo-[4,5-b]-quinoxazo-3
'-Indolocarbocyanine iodide (D-2) Pinacryptol Yellow (D-3)
1. Ding, 3.3.3', 3'-hexamethyl-
5,5'-dinitroindocarbocyanine p-toluenesulfonate (D-4) 5.5-dichloro-3,3'-diethyl-6,6'-dinitrothiacarbocyanine iodide (D-5) 1. 1-dimethyl-2,2'-diphenyl-3゜3'-introcarbocyanine bromide (D-6) 1.1'-3,3'-tetraethylimidazo[4゜5-b]quinoxalinocarbocyanine chloride (D-7) 5-m-nitrobenzylidenerhodanine (D-8) 6-chloro-4-nitrobenzotriazole (υ-9) 19-dibutyl-4,4'-bipyridinium dibromide ( D-10) 1. D-ethylene-2,2'-bipyridinium dibromide (D-11) 4- (p-n-amyloxyphenyl)
-2,6-di(p-ethylphenyl)thiapyrylium
Berchlorate (D-12) 2-mercapto-4-methyl-5-nitrothiazole (013) 2- (0-nitrostyryl)-3-ethylbenzothiazolium P-toluenesulfonate (D-14) 2- (p-nitrostyryl)-quinoline p-toluenesulfonate (Di5) phenosanolanine (D-16) pinacryptol green (D-17)
2. 3-Dimethyl-6-nitropenzothiazolium p-toluenesulfone 1 to use of organic desensitizer, 0.05 to 5 g per mole of silver halide, preferably 0.
The amount is selected within the range of 1 to 3 g, but when used in combination with the water-soluble rhodium salt described later, the purpose of the present invention can be achieved even with less than this amount.

The timing of addition is not limited, although it is generally added after the completion of ripening.

In the present invention, examples of the water-soluble rhodium salt used include rhodium dichloride, rhodium trichloride, ammonium hexachlorodate, etc., and preferably a complex compound of rhodium trichloride and a halogen.

The amount added is preferably 10-3 to 10-6 mole per mole of silver halide, but when the above-mentioned organic desensitizer is used at the same time,
The object of the present invention can be achieved even if the amount is less than this. Addition of 10 −3 mol or more of water-soluble rhodium salt causes softening of the tone. On the other hand, if an organic desensitizer is not used at the same time, if the amount is less than 10-8 mol, desensitization cannot be achieved until it can be safely handled in a bright room.

In the present invention, to prepare silver halide in the presence of a water-soluble rhodium salt, the water-soluble rhodium compound may be added by any method at any time during emulsification and physical ripening.

The silver halide emulsion used in the present invention has at least 8
This is a negative emulsion containing 0 mol% silver chloride.

A negative emulsion is a normal type of silver halide emulsion that forms a negative image on a positive original, which is distinguished from a direct positive silver halide emulsion.

Preferably, it is a silver halide emulsion containing 90 mol% or more of silver chloride. If the silver chloride content is less than 80 mol%, it is inconvenient to achieve the purpose of the present invention. It is preferable that silver iodide is not substantially contained, but a very small amount, for example, about 0.2 mol %, can be contained if necessary.

The silver halide emulsion used in the present invention is a fine grain silver halide, preferably having an average grain size of about 0.05 to 0.3 grains. In addition, more than 90% of the total number of particles has an average particle size of ±1
Those having a particle size in the range of 0% are preferred. The silver halide emulsion may be prepared by any known method such as forward mixing, back mixing, and simultaneous mixing. The emulsion prepared in this way may be subjected to chemical ripening; Even without this, the purpose of the invention is achieved. What is chemical ripening?
This is a step of sensitizing the material at a predetermined temperature and time in the presence of a chemical sensitizer (for example, sodium thiosulfate, etc.) after physical ripening and desalting treatment, and is obvious to those skilled in the art.

The silver halide emulsion obtained according to the present invention contains stabilizers, antifoggants, covering power improvers, ylan 1-ion inhibitors, film property improvers, surfactants, hardeners, matting agents, developing agents, etc. It can contain additives used in general photographic emulsions, and is coated on a known support. It may also have a hydrophilic colloid layer such as a protective layer or an undercoat layer.

The silver halide photographic light-sensitive material for bright room use obtained by the present invention is exposed to light from 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.

(E) Examples Example 1 Silver halide was precipitated in a conventional manner using 100 mg of adenine and 10-5 moles of rhodium chloride salt per mole of silver chlorobromide containing 95 mol% of silver chloride. A monodisperse emulsion with an average grain size of 0.2 llft was obtained by ripening. This emulsion was desalted and redissolved as an organic desensitizer.
Pinacryptol yellow (D-2) to 1 part silver halide
Add 500 fff per mole of silver, add 50 m'j of 2-mercaptobenzoic acid per mole of silver, and further add a hardener and a surfactant, so that the amount of silver is 3.2 g on the polyester film.
/m together with the gelatin solution for the protective layer and dried. (Sample 1) This sample was exposed to light for sensitometry using a bright room printer, developed with a D-85 developer at 20° C. for 2 minutes, fixed, and dried.

It had good characteristics with a gradation gamma (γ) of 7.1 and a fog value of 0.02. Furthermore, when this sample was left for 5 minutes under bright room light of about 200 lux using a commonly used fluorescent lamp containing ultraviolet light, and then developed in the same manner as above, the fog value was as low as 0.04. However, when this sample was heated at 55°C and 50% relative humidity for 3 days, left in the bright room light for 5 minutes, and then developed in the same manner as above, the fog value increased to 1.20. did.

Furthermore, a sample was prepared exactly the same as Sample 1 except that 2-mercaptobenzoic acid was replaced with 4-mercaptobenzoic acids and a comparative compound, and the relative sensitivity when the same development treatment was performed after the above sensitometry exposure, Gradation gamma (γ), undercut, and fog value when left under bright room light containing ultraviolet rays for 5 minutes and subjected to similar development processing,
Further, the samples were heated at 55° C. and 5% relative humidity for 3 days, then left in a bright room under light in the same manner as above, and developed. The fog values are shown in Table 1 below. The breakage value is determined by visually evaluating the breakage at the foot of the characteristic curve on a five-point scale, with 1 being the best and 5 being the worst.

(Margins below) The results in Table 1 show that the 4-mercaptobenzoic acids of the present invention do not significantly change photographic properties at 55°C and relative humidity.
After heating at 0% for 3 days, fogging when left under bright room light as described above can be significantly reduced, indicating that stability over time is improved.

Example 2 Example 1 was followed except that the organic desensitizers were combined as shown in Table-2. After heating a sample using 2-mercaptobenzoic acid or 4-mercaptobenzoic acid at 55°C and 50% relative humidity for 3 days, the fog was observed when it was left under the bright room light containing ultraviolet rays for 5 minutes. It is shown in Table-2.

(Leaving space below) Table 2 The results in Table 2 show that when using 2-mercaptobenzoic acid with any organic desensitizer, after heating at 55°C and 50% relative humidity for 3 days, it was left in the bright room under the light. This results in severe fogging, but 4-mercaptobenzoic acid improves both, indicating that stability over time can be improved.

(F) Effects of the Invention The silver halide photographic light-sensitive material for bright room use obtained by the present invention does not deteriorate in safety under bright room light without removing ultraviolet rays, and can be used after long-term storage. Even when cleaning, it can be handled safely in a bright room.

Claims (1)

[Claims] The silver halide emulsion layer provided on the support is at least 80%
In a silver halide photographic light-sensitive material for bright room use, which contains at least one type of desensitizer in a negative fine-grain silver halide emulsion containing mol% silver chloride, the silver halide emulsion layer or a layer adjacent to the emulsion layer contains 4. - A silver halide photographic material containing at least one type of mercaptobenzoic acid.