JPS606495B2 - Heat-developable photosensitive material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat-developable photosensitive material, and more specifically, by containing a nitrogen-containing organic base whose conjugate acid has a pKa of 0.5 to 10.0, This invention relates to a heat-developable photosensitive material that has significantly increased photosensitivity.

Conventional photographic methods using silver halide emulsions are extremely superior in terms of sensitivity, gradation, and image quality, but the development and fixing processes are green and time-consuming, and each process uses harmful chemicals.
There were various problems such as the water coming into contact with workers' hands and the need for wastewater treatment.

Therefore, heat-developable photosensitive materials have been proposed that can easily form images by short-time dry processing without liquid processing, and various efforts have been made to date. The main image forming agent of this heat-developable photosensitive material is an organic silver salt oxidizing agent, and the material includes a type that can form an image by exposure and heat development (hereinafter, this type is referred to as a preactivated type); Both types (hereinafter referred to as post-activation type) that can form an image by preheating treatment, exposure to light, and thermal development have been proposed.
The former pre-activation type is mainly composed of an organic silver salt oxidizing agent, a small amount of silver halide in catalytic contact with the reducing agent, and the latter post-activation type is pre-heated. Photosensitivity is imparted only when strained, and it remains non-photosensitive under room light until heat pretreatment is applied. but,
All of these types of heat-developable photosensitive materials have the disadvantage of significantly lower photosensitivity than wet silver halide photography.

For this reason, the use of this material as a general-purpose photosensitive material is currently limited. Therefore, the present inventors have attempted to overcome the above-mentioned drawbacks by using halogen molecules as all or a part of the photosensitive silver halide forming component.
Furthermore, it was found that a heat-developable photosensitive material with significantly superior sensitivity and stability of the raw material could be obtained by incorporating a compound organic base with a conjugate acid pKa of 0.5 to 10.0. I put it out.

From the conventionally known facts, it is expected that the stability of the green photosensitive material of heat-developable photosensitive materials is significantly deteriorated in the presence of a nitrogen-containing organic base. Therefore, the effect of the present invention that sensitization can be achieved without impairing the stability of raw materials by adding a base is a surprising result that could not be expected from conventional common sense. The composition of is acidic in the absence of a base, and halogen molecules with strong oxidizing power coexist, so it is assumed that significant sensitization can be achieved using a base without sacrificing stability. The present invention uses a) an organic silver salt oxidizing agent, b) a rurogane molecule, c) a reducing agent for silver ions, and d) a conjugate acid with a pKa of 0.
5-10.

It is characterized by containing a nitrogen-containing organic base having a value of 0.

Examples of the nitrogen-containing organic base of component d) used in the present invention include pyridine, quinoline, inquinoline, acridine, phenanthridinetopyridazine, pyrimidine, pyrazine,
Cinnoline “phthalazine to quinazoline, quinoxaline,
Examples include fuenazine, phenanthroline, pteridine, pyrazole, imidazole, benzimidazole, and substituted products thereof.

Substituents include, but are not limited to, alkyl groups, substituted alkyl groups, aryl groups, substituted aryl groups, nitro groups, halogen groups, nitrile groups, alkoxy groups, carboxyalkyl groups, etc. , derivatives in which the pKa of the conjugate acid of the organic base is between 0.5 and 10.0 are effective.

Further, N-alkylmorpholine, trialkylamine, etc. can also be used if the pKa of the conjugate acid does not exceed 10.0. However, a substance with a high pKa (pKall. 3), such as acetidine, ``even if a small amount is used, the photosensitive material obtained is extremely unstable upon storage.

On the other hand, with a substance having a small pKa such as 2-fluoropyridine (pKa...0.4), almost no sensitization is observed.

Many of the above-mentioned nitrogen-containing organic bases that do not have acidic protons in the same molecule fall under this category. In addition, bases with acidic protons in the same molecule, such as penzimidazole,
Sensitization is observed when the proton pKa is greater than 12, such as pyrazole, but no significant sensitization is observed when the proton pKa is less than 12, such as penztriazole and tetrazole. In addition to these conditions,
Those that are stable against oxidation and stable under acidic conditions are more preferred.

2
- Chlorpyridine "3-Chlorpyridine, 2-frompyridine t3-Frompyridine" 2-Methylpyridine, 3
M Methylpyridine, 4-methylpyridine "2-isopropylpyridine, 2-t-butylpyridine, 3-phenylpyridine 2,6-di-t-butylpyridine ~ 3-acetylpyridine ~ 8,8'-dipyridyl, y,y '-dipyrdyl, 2-methylquinoline, 3-methylquinoline, 4
-Methylquinoline "2-chloroquinoline, 4-chloroquinoline, 1-methoxyisoquinoline" 4-methylpyrimidine, 2W dimethylaminopyrimidine, 2-methoxyquinazoline, 2-methylquinoxaline, 1-methylpyrazole, etc.

For example, the pKa value and measurement method can be found in Introduction to Heterocycle Chemistry (A
drienAiben, ``Chemical Handbook (Maruzen), translated by Banji Nakanishi, and Acidobe-Securibria (Ac.
id- alreadyseEouiribria) (E.J.Kin
Author: PerrinmonPress, New York. 1
965). Next, component a), the organic silver salt oxidizing agent, is extremely stable against light and reacts with the reducing agent when heat-developed to produce a silver image.

Higher fatty acid silver such as silver laurate, silver palmitate, silver stearate, silver arachinate, silver behenate, silver penztriazole, silver saccharin, etc. Among them, there is a slight fog during heat development, ~stearin Silver acid, silver arachinate, silver behenate is most preferred. The halogen molecules of component b) are iodine molecules, bromine molecules, bromine iodide, iodine chloride, bromine chloride.

Among these, iodine molecules are the most preferred because they are solid in normal state and are easy to handle. At least a portion of these halogen molecules form photosensitive silver halide during the preparation of emulsions for image-forming materials or during heat treatment of image-forming materials. It can also be used in combination with component c), which is a reducing agent for silver ions.Next, as a reducing agent for silver ions in component c), any of those commonly used in this field can be used, and particularly preferred are inhibiting fufunols. .

For example, Q,Q'-(3,5-di-t-butyl-4-hydroxyphenyl) dimethyl ether, 2,6-bis(
3-t-butyl-2-hydroxy-5'-methylbenzyl)-4-methylphenol "2,2'-methylenebis(4,6-di-t-butylphenol), 2,2'-methylenebis(6-t-butyl-4- ethylphenol)
, 2,4,4-trimethylbentylbis-(2-hydroxy-3,5-dimethylphenyl)methane, and the like.
Others hydroquinone, 2,2-dihydroxy-1,1
-binaphthyl, methyl gallate and the like are also preferred. Two or more of the above reducing agents may be used in combination. Next, in addition to the above-mentioned components, it may contain, if necessary, a spectral sensitizing dye, a color toning agent, a heat fog inhibitor, an image stabilizer, etc., which are commonly used in this field.

Preferred spectral sensitizing dyes include cyanine, merocyanine, and rhodacyaniso dyes. In particular, merocyanine dyes are preferred because of their high spectral sensitizing ability. Among these, merocyanine dyes having an imino group or a carboxyl group are preferred. These dyes may also be used in combination. Also, effective antifogging agents include mercury ions such as mercury acetate and mercury halides, zinc acetate, calcium acetate, rosin, and phthalic acid. Examples of image stabilizers include tetrabromobutane and hexabromocyclohexane.The light-sensitive material used in the present invention may also contain antihalation substances or antihalation dyes commonly used in this field, if desired. be able to.

Each component and each additive of the above heat-developable photosensitive material can be used by being dispersed in various binders.

As a binder, polyvinyl butyral, polvinyl formal, polyvinylpyrrolidone, polystyrene, polymethyl methacrylate, polycarbonate, polyvinyl acetate, polyvinyl chloride, vinyl acetate-vinyl chloride copolymer, cellulose acetate butyrate, ethyl cellulose, Examples include cellulose acetate, cellulose acetate butyrate, polyamide resin, polyvinyl alcohol, gelatin, and collodion. Two or more of these can also be used as a mixture. In addition, each component dispersed in the above binder and The support to which each additive is applied is not particularly specified as long as it is stable against heating.

For example, plastic films such as polyethylene terephthalate, polycarbonate, polyvinyl acetal, cellulose ester, metal foils such as aluminum, glass, various papers, etc. are suitable. Further, the above-mentioned components and additives are dispersed in the binder and applied onto the support. Further, each of the above-mentioned components and additives may be used by being dispersed in two or more layers and laminated.

The sensitivity of the heat-developable photosensitive material having the above composition is increased by preheating treatment. The temperature of the heating pretreatment is 90o~1
5000 is preferable, and the heating time is as high as the heating temperature,
Becomes shorter. The heat development is carried out at a temperature of 900C to 160OO, preferably 11000 to 135OO. As the heating method, a method normally used in this field can be used as appropriate.
EXAMPLES Hereinafter, the present invention will be explained in detail with reference to Examples, but the present invention is not limited thereto. Example 1 A silver behenate suspension was prepared by ball milling 4 parts of silver behenate and 2 $ parts of a methyl ethyl ketone:toluene mixture (2:1 weight ratio) for 24 hours.

Using this suspension, the following composition was mixed and coated onto a polyester film. Coating emulsion 1st layer Silver behenate suspension 12.0 Polyvinyl butyral 3.
0 methyl ethyl ketone 12.0 mercury acetate 0.05 iodine 0.129 Nitrogen-containing organic base compound, amount added and p
Ka is shown in Table 1.

2nd layer cellulose acetate 1.2 tacetone 16.3 ts Phthalazinone 0.28 ts 2,2'-methylenebis(6-t-butyl-4-ethylphenol) ○-70 ts The first layer composition was added as above. Followed the order of description.

After the first layer was applied and dried, the second layer was applied. The photosensitive film obtained is insensitive to normal light, so
After preheating for 5 seconds at qo, the film was exposed to 1' developer sand using a 500W xenon lamp, and developed for 1 second at 13,000.
The optical density of the obtained image is maximum 0. D. max and optical density min 0. D. min, and the raw film at a temperature of 50qo
After being exposed to the conditions of 90% relative humidity for 2 hours, an image was formed using the same image forming process as described above. D. ma
x, 0. D. Table 1 shows the min as the stability of the raw film. The nitrogen-containing organic bases in Tables 1, b, and m below indicate photosensitive films containing the nitrogen-containing organic bases.

Table 1 Nitrogen-containing organic bases (Minato Futami Toyotsu) of conjugate acids.

-0 skin aX. -U skin in raw film stability pKa0. U
. max0. D. min exists--0,340.060.
170.07 Hyridine 0.305.21.880.06
1.830.07 Quinoline 0.304.92.550.
062.500.06 Inquinoline 0.305.42.
630.072.540.07 Pyridathon 0.302.
31.550.061.480.08 Pyrimison 0.3
01.32.200.081.210.09 Phthalazine 0.053.52.230.062.300.06 Quinazoline 0.603.52.410.062.130.0
7 Quinoxaline 0.600.71.900.061.9
00.06 pyrazole 0.052.52.380.07
2.440.09 Pyrolithone 0.0511.31.83
0.101.660.30 (Comparative Sample) Example 2 Using the silver behenate emulsion of Example 1, the following composition was mixed and coated onto a polyester film.

1st layer silver behenate suspension i2.0 polyvinyl butylene 3.
0 methyl ethyl ketone 12.0 mercury acetate 0.05 diphenyl tellurium dibromide 0.05 taurine 0.1
The name of the nitrogen-containing organic base compound and the amount added are shown by Ko Omotegawa.

2nd layer polymethyl methacrylate 1.2% methyl ethyl ketone 16.3 taffetaazinone 0.28% 2,2-methylenebis-(6-t-butyl-4-methylphenol) 0.7
The order of addition of the first layer was in accordance with the order described above.

After the first layer was applied and dried, the second layer was applied. The photosensitive film obtained is insensitive to normal light, so it is
After preheating at 00 for 1 second, exposure was performed for 1'60 seconds using a 300 W tungsten lamp, and development was performed for 3 seconds at 12,000. Maximum optical density of the obtained image〇D. max and minimum optical density〇D. min, and the raw film at a temperature of 6
000, and after being exposed to conditions of 90% relative humidity for 1 hour, 0.D of the image formed by the same image forming process as above.
．． max, 0. D. Table 01 shows the stability of the raw film as min. Table 2. Nitrogen-containing organic bases and nitrogen-containing conjugate acids.

-D, maX. -D-mind
No pKa of added amount of group--0.200.060.18
0.08 Quinoline 0.304.91.990.071-
810.072-Methylquinoline 0.305.41.8
60.061.850.065-Methylquinoline 0.3
04.61.900.061.910.063-Chlorquinoline 0.302.41.600.061.430.
06 Pyridine 0-305.21.470.071130
0.07o,o'-dipyrisol 0.154.41.88
0.061.870.062M {monobutylpyridine 0.061.870.062M
305.82.010.072.100.082,6-
Diimbrovirpyridine 0.305.31.970.0
62.100.093-acetylpyridine 0.303.
21.680.071.560.07 Pyrimidine 0.3
01.31.540.08-1.440.084-Methylpyrimidine 0.202.01.730.081.74
0.08 Phthalazine 0.103.52.250.062
．． 200.06 Pyrazo 0.102.51.580.07
1.500.093-Methylpyrazole 0.103.6
1.900.062.000.09 Penztriazole 0.301.60.530.060.480.06 (Comparative sample) Tetrazole 0.300.420.050.3
60.06 (comparative sample) The pKa of acidic protons of benztriazole and tetrazole is 8.57 for the former.
, the latter is 4.9.

Comparative Example A film was prepared by repeating the same operations as in Example 1 except that 0.10 g of ammonium bromide was used in place of iodine in Example 1.

The obtained photosensitive film was heated with a 500W xenon lamp for 1'
It was exposed for 8 seconds and developed at 13000 for 1 second. The maximum optical density of the obtained image is 0. D. max and minimum optical density 0.
D. min and the raw film at a temperature of 5000 and a relative humidity of 9.
After being exposed to 0% conditions for 24 hours, an image was formed using the same image forming process as above. D. max, 0. D. m
In is shown in Table m as the raw film stability. No. m Nitrogen-containing organic base electrotoxin end treatment at the home of K.

Claims (1)

[Claims] 1 At least a) an organic silver salt oxidizing agent, b) an iodine molecule,
c) reducing agents for silver ions, and d) pyridine, quinoline, isoquinoline, acridine, phenanthridine,
A nitrogen-containing organic base selected from pyridazine, pyrimidine, pyrazine, cinnoline, phthalazine, quinazoline, quinoxaline, phenazine, phenanthroline, pteridine, pyrazole, imidazole, benzimidazole and substitutes thereof, and the nitrogen-containing organic base is There is no acidic proton in the same molecule, and the pKa of the conjugate acid is 0.5 to 1.
It is characterized by containing four components: a nitrogen-containing organic base having a value of 0, or a nitrogen-containing organic base having an acidic proton in the same molecule and having a conjugate acid pKa of 0.5 to 10. A heat-developable photosensitive material that is sensitized by preheating.