JPS59157633A - Manufacture of silver halide photographic emulsion - Google Patents

Abstract

PURPOSE:To enable handling in the light room by incorporating a silver halide emulsion specified in grain diameter and an org. desensitizing agent in an emulsion. CONSTITUTION:A negative type fine grain silver halide photographic emulsion having 0.1-0.3mum average grain diameter and contg. at least 80mol% silver chloride incorporates a water-soluble rhodium salt in an amt. of 10<-8>-10<-5>mol per mol of silver halide and an org. desensitizing agent having a positive sum of both anode potential and cathode potential of the polarograph. An amt. of rhodium salt to be added can be reduced as compared with the case of adding only the rhodium salt, so the obtained emulsion can be enhanced in sensitivity and contrast. As the org. desensitizing agent, ordinary agents, such as pinacryptol yellow and green, and phenosafranine, can be used.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a silver halide photographic emulsion, and more particularly to a method for producing a silver halide photographic emulsion suitable for light-sensitive materials for bright room use.

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, photographic Finrem, which has an ultra-low sensitivity of about 10-3 to 10-5 compared to the conventionally used return film, has been developed, and it is a return film that can be handled in a bright room, that is, a light-sensitive material for bright rooms. It has begun to be put into practical use.

The performance required of such a light-sensitive material for use in a bright room is that it has a sufficient maximum density with high contrast, can be handled for a long time in a bright room, and has high sensitivity to printer light sources. This is the case. However, conventional photosensitive materials for bright room use are
It is difficult to say that the performance described above is fully satisfied.
The development of improved photosensitive materials for use in bright rooms is desired.

As a silver halide emulsion for light-sensitive materials, JP-A-56
10-5 to 10-3 per mole of silver halide containing at least 90 mole of silver chloride.
Emulsions using molar rhodium salts are described. This emulsion uses a large amount of rhodium salt as an inorganic desensitizer.

However, the present inventors have confirmed that the photosensitive material for bright rooms using this emulsion has a serious drawback in that it can only ensure extremely insufficient safety when handling in bright rooms.

The present invention provides a method for producing a silver halide photographic emulsion that has high sensitivity and high contrast characteristics when printed with a light source rich in ultraviolet light, and has improved handling safety in a bright room where ultraviolet light is cut. The purpose is to

As a result of intensive research to achieve the above object, the present inventors have found that the average particle diameter is 0.1 to 0. When producing a silver halide photographic emulsion containing at least 80 mol of silver chloride in a water-soluble rhodium salt containing 10 to 10 mol of water-soluble rhodium salt per 1 mol of silver halide and the sum of the anode potential and cathode potential of the polarograph being positive. This was achieved by a method for producing a negative-working silver halide photographic emulsion, which is characterized by the addition of a certain organic desensitizer.

The present invention will be explained in more detail below.

Generally, emulsions with ultra-low sensitivity that can be used as light-sensitive materials can be obtained by using inorganic desensitizers such as rhodium salts or organic desensitizers such as pinacryptol yellow.

The one using rhodium salt is disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 56-1257.
No. 34, a photosensitive material coated with this emulsion causes significant capri when handled for a long time under bright room light. If the amount of rhodium salt is reduced, the same fogging problem will occur as the sensitivity increases, and the tone will also become softer.

By using an organic desensitizer as the main desensitizer and combining it with a small amount of rhodium salt, handling safety under bright room light is significantly improved, and a light-sensitive material with particularly high contrast characteristics can be obtained. I found it. Said Japanese Unexamined Patent Publication No. 56-1257
When a large amount of rhodium salt is combined as described in No. 4, the tone is softer than that of the light-sensitive material according to the present invention, and furthermore, it can be left under bright room light after image exposure until development. It has also been found that this causes a significant decrease in sensitivity. The rhodium salt is 10-
5 to 10-8 moles, preferably 5X10' to 5X10
``The amount added in moles.

The water-soluble rhodium salt used in the present invention may be one that has been lacking in the past, but typically rhodium monochloride, rhodium digloride, rhodium trichloride, rhodium ammonium chloride, etc. are used.

It is generally preferable to use the rhodium salt during precipitation or physical ripening of silver halide, but it can also be used at any time thereafter.

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 characterized by its polarographic tear semifluid potential, ie its redox potential determined polarographically.

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.

Specific examples of such organic desensitizers are described in numerous patent specifications and literature, all of which are not applicable to the present invention.
For example, it has the same effect in
o-2a 7 s 1, Showa 43-13167, Showa 4
5-8833V 1974-8746. 1971-101
97, 1977 5O-37530X JP 48-24734
X 49-84639 14252 U.S. Patent No. 227122 No. 2541472, No. 303
No. 5917, No. 3062651, No. 312445
Compounds described in specifications such as No. 8, No. 3326687, and No. 3671254 can be used.

An example is shown below.

(1)-1) 1,3-diethyl-11-methyl-21-
Phenylimidazo(:4,5-b)-quinoxazino-3
1-Indolocarbocyanine iodide (D-2) Pinacryptol Yellow (D-3
) 1.1', 3.3.3', 3'-hexamethyl-
5,5'-dinitroindocarbocyanine P-)luenesulfonate (p-4)s,s-dichloro-3,31-diethyl-6
゜6hinitrothiacarbocyanine iodide (D-s) 1.1μ dimethyl-2,21-diphenyl-
33'-f androcarpocytenin bromide (D-
6) 1.1', 3.3'-tetraethylimidazo (
4,5-1)] quinoxalinolupocyanine chloride CD-7) 5-m-=tobenzyritinlogenine (D
-s) 6-chloro-4-nitrobenzotriazole (D-9) 1.1+-dibutyl-4,4I-bipyridinium-dibromide (D-10) l, 1'-ethylene-2,2'- Bipyridinium dibromide (D-11) 4-(P-n-γξloxinenyl)-2゜6-di(p-ethylphenyl)thiavilirum.
Barchlorate (D-12>2-mercapto-4-methyl-5-dito a
Thiazole (D-13) 2- (0-nidos/L/) -
s' -xyrruhenzotibuzolium/P-toluenesulfonate (D-14) 2- (P-nitrostyryl) ~ quinoline/P-toluenesulfonate (D-1s) Phenosafranine (D-16) Pinacryptol green ( D-1
7) 2,3-dimethyl-6-nitro-benzothia/”l
The amount of the organic desensitizer (M-P-) luenesulfonate used is 50 to 50 per mole of silver halide.
5000mg 1 Preferably selected in the range of 50 to 5000r1g. It is generally added after ripening.

The silver halide emulsion used in the present invention has at least 8
This is a negative emulsion containing 0 mol of 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. A silver halide emulsion containing preferably 90 moles or more of silver chloride may be included as required.

The silver halide emulsion used in the present invention has an average grain size of 0.
1 to 0.37A. The method for calculating the total number of particles is
Any known method such as forward mixing, back mixing, or simultaneous mixing may be used.

In order to preferably achieve the object of the present invention, it is better not to substantially perform chemical ripening. Chemical ripening is a process of sensitizing at a predetermined temperature and time in the presence of a chemical sensitizer (for example, sodium thiosulfate) after physical ripening and desalting treatment, and is obvious to those skilled in the art. belongs to.

A silver halide emulsion, a base, a stabilizer, obtained according to the present invention,
It may also contain other hydrophilic colloid layers such as an undercoat layer containing antifoggants, covering power improvers, anti-irradiation agents, film property improvers, surfactants, hardeners, matting agents, developing agents, etc. .

The photosensitive material for bright room use obtained by the present invention can be used mainly from light sources rich in ultraviolet light used in the printing field, such as mercury lamps,
Exposure is performed using an ultra-high pressure mercury lamp, metal halide, etc.

The photosensitive material for bright room use obtained according to the present invention can be safely handled for a long time under bright room light, both before and after the above-mentioned exposure.

Example 1 Silver halide was precipitated in a conventional manner using 10-6 mol of rhodium chloride salt per 1 mol of silver chlorobromide containing 95 mol of silver chloride, and subjected to physical ripening to obtain an average side diameter. 0.2
A monodispersed emulsion was obtained in step 7. After desalting and redissolving this emulsion, Pinacryptol Yellow was added as an organic desensitizer.
(D-2) was added as a halogen, 200 mg of 1 mol of silver nitride was added, and a stabilizer, a hardening agent, and a surfactant were added to form a protective layer of 5 g/m' of silver nitrate on the polyester film. It was coated with gelatin solution and dried.

This sample was exposed to light for sensitometry using a printer for bright rooms, and was heated at 20°C using a D-85 developer.

Developed for 2 minutes, fixed, and dried. The gradation gamma (rJ) was 5.5 and the Capri value was 0.04. Also, when this sample was irradiated for 5 hours in a bright room under about 500 lux and then exposed and developed in the same manner as above, the sensitivity was , and then irradiated for 15 minutes in the above-mentioned bright room and developed in the same manner, the sensitivity was 90% of the above sensitivity, and there was no change in gradation or capri.

For comparison, the rhodium salt of the above emulsion was
A sample prepared in exactly the same manner except for using molar values had a gamma of 3.8 and a capri of 0.03. This sample was desensitized to a sensitivity of 40% in the bright room light irradiation test after exposure. Furthermore, a sample prepared in exactly the same manner except that the rhodium salt was removed from the emulsion of the present invention was a comma 3.3 turnip I.
J0.04, and the sensitivity was desensitized to so% in the bright room light irradiation test after exposure.

Example 2 Organic desensitizers (D-1), (D-s), (D-6), (D
-7), (D-8), (D-9), (D-10),
Both samples have a gamma of 5.2 to 5.7 and a capri value of 0.03 to
0.04, and regarding the safety under bright room light according to Example 1, no increase in Capri was observed at all, and desensitization was as small as 5 to 15%.

Claims (1)

[Scope of Claims] α) A water-soluble rhodium salt with an average particle size of 0.1 to 0.3/L and at least 80 mol and 10-8 to 10-5 mol and a polarograph whose sum of anode potential and cathode potential is positive. A method for producing a silver halogenide photographic emulsion, which comprises adding an organic desensitizer. (2) The manufacturing method according to claim 1, which does not substantially involve chemical ripening.