JPS6022338B2 - Heat-developable photosensitive material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat-developable photosensitive material, and more particularly to a phenol heat-developable photosensitive material whose sensitivity is increased by the addition of a phenol derivative.

Silver halide photographic materials, which have traditionally been used in a wide range of image forming methods, have a
While it has a wide range of uses due to its excellent photographic performance including photosensitivity, it has disadvantages such as the fact that processing such as development and fixing is wet, making processing complicated. It has several points.

However, many attempts have been made to simplify the treatment process by using a dry process instead of relying on such a wet process.

In particular, as a noteworthy image forming method, a thermophenomenal photosensitive material in which the developing step is performed by heat treatment has been proposed. for example,
Mochiko No. 4924/1984 describes a thermophenomenal photosensitive material consisting of a silver halide in catalytic contact with an organic silver salt, a reducing agent, and an organic silver ion.
Further, similar devices are also described in the specification of Mochiko Sho 44-26582, Hakama-Seki Sho 46-6074, and the like. In addition, the detailed cost of Samurai Seki Shomitsuichi No. 97523 is as follows:
A heat-developable photosensitive material containing no silver halide, consisting of a long-chain fatty acid salt, an organic reducing agent, and an organic carboxylic acid, is activated by heat treatment to impart image-forming ability and form an image. A method is described in Hakamaseki Sho 49-1003y, which comprises a silver salt of the longest chain fatty acid, a halogen compound capable of supplying halogen ions, and an organic reducing agent on a support.

It is possible to prepare a heat-developable photosensitive material with little or no image forming film without preheating and preheating the iron layer at least before image exposure and heat development. There is a description of a method for forming an image by giving an image, and after receiving the image, thermally developing it. These heat-developable photosensitive materials have a great advantage over ordinary silver halide photographic materials in terms of ease of processing, but their photosensitivity is still insufficient, and in recent years industrial With the development, it is highly expected that the applications will expand and the sensitivity will increase.

Therefore, an object of the present invention is to provide a heat-developable photosensitive material that has high photosensitivity and can be applied to a wide range of uses.

Conventionally, many studies have been conducted on chemical sensitization methods for silver halide photographic materials, such as sulfur sensitization method,
Reduction sensitization methods and noble metal sensitization methods are widely used. However, the application of the sensitizing method applied to these silver halide photographic materials to the deep visibility photographic material is accompanied by disadvantages such as fogging, and both are inconvenient and cannot yield satisfactory results. Not yet. As a result of various experiments and studies in order to obtain a highly sensitive thermally sensitive photosensitive material, the present inventors have found that at least one layer containing at least a) a reducible organic linear salt and b) a reducing agent is formed on a support. In the heat-developable photosensitive material consisting of forming a photosensitive material, by containing at least one kind of phenol transferor represented by the following general formula in at least one of the layers, excellent photosensitivity can be achieved without fogging, coloring, etc. It has been found that it is possible to obtain a heat-developable photosensitive material having the following properties. General formula [wherein R represents a hydrogen atom, a hydroxyl group, or an alkoxy group, and R2 represents a linear or branched alkyl group, a substituted or unsubstituted aryl group, or an aralkyl group] Phenol derivatives used in the present invention Typical examples are listed below, but the present invention is of course not limited to these examples.

Compound Examples These phenol derivatives can be easily synthesized by a conventional method from a corresponding substituted or unsubstituted salicylaldehyde and a corresponding amine.

For example, the synthesis of Exemplified Compound 1) -(n-butyliminomethyl)phenol is as follows. 3.7 parts of n-butylamine are dissolved in 25 parts of ethyl alcohol, and 6.1 parts of salicylaldehyde are added dropwise while stirring at room temperature.

Heat for a while on a water bath, and ethyl alcohol is distilled off under reduced pressure. Distilling the resulting yellow liquid under reduced pressure; b. p2.5143~
Take the fraction of 143.5pm. Yield: 66.6% Other phenol derivatives used in the present invention can be easily synthesized by the same method.

The compound used in the present invention has excellent solubility in various solvents, so it is easy to add.Also, although some Schiff bases are unstable, the compound used in the present invention is very stable, and the compound No changes occur not only in itself but also during storage in the photosensitive material.

In addition, it has the advantage of being easy to synthesize and can be carried out in good yield, so it can be obtained at low cost.

The method of adding the compound according to the present invention is not particularly limited. directly into the heat-developable photosensitive coating solution, or after coating and drying the photosensitive coating solution on the support,
For example, the compound according to the present invention may be added after being immersed in a solution containing the compound. In addition, the amount added is generally as follows:
1.0 to 0.00 per mole of silver salt of long chain fatty acid
001 mol, particularly preferably 0.1 to 0.00
The amount is 1 mol, but is not particularly limited to this.

In carrying out the present invention, the reducible organic silver salts used include the silver salts of organic acids described in the above-mentioned Samurai Ko No. 43-4924 and Samurai Seki No. 46-6074; / group or mercapto group, and are resistant to unfavorable changes such as discoloration at room temperature and under indoor light, such as silver behenate, silver stearate, palmitic acid, etc. Silver salts of long chain fatty acids such as silver, silver myristate, silver laurate, silver oleate or silver hydroxystearate are suitable.

Further, as the reducing agent, developers used in ordinary silver halide photosensitive materials, such as hydroquinone, methylhydroquinone, chlorohydroquinone, methylhydroxynaphthalene, N.I. N'-diethyl-P-phenylene diamine, aminophenol, ascorbic acid, 1-phenyl-3-pyrazolidone, etc. are used, and in addition to these, 2,2-methylenebis(6-tertiarybutyl-4-
methylphenol), 4,4-butyldenbis (6-tert-butyl-3-methylphenol), 4,4-thiobis (6-tert-butyl-3-methylphenol), etc. The bisnaphthol-based reducing compounds described in No. 6074 can also be effectively used.

In the present invention, it is possible to use a heat-developable photosensitive material containing a halide radiation such as silver bromide, silver chloride, silver iodide, silver iodobromide, and silver iodochloride. Particularly fine particles are effective, and as a preferred example, part of the reducible organic silver salt is halogenated to prepare fine silver halide for use.

In the present invention, color toning agents can also be used. For example, phthalazinone or its derivatives described in U.S. Pat. Cyclic imides are also effective. Furthermore, phthalazinedione compounds described in Hakama Seki Sho 50-132927 can also be used effectively. The heat-developable photosensitive material of the present invention may be used by adding thiazolium salts, azaindene compounds, or mercury salts described in U.S. Pat. No. 3,9903 as antifoggants and storage stabilizers. I can do it.

It is also possible to add and use spectral sensitizing dyes such as cyanine dyes, merocyanine dyes, and xanthene dyes. Furthermore, the present invention can be used by adding binders, ultraviolet absorbers, optical brighteners, antistatic agents, fillers, etc. as appropriate.
As the binder, polyvinyl butyral, cellulose acetate butyrate, polymethyl methacrylate, polyvinylpyrrolidone, ethyl cellulose, cellulose acetate, polyvinyl acetate, polyvinyl alcohol, gelatin, etc. are preferably used in the present invention.

The support used in the present invention is not particularly limited as long as it is stable against heating, but preferably synthetic resin films such as polyethylene terephthalate, polycarbonate, and cellulose acetate, synthetic paper made from these materials,
Paper coated with these resins, metal plates such as aluminum,
These include photographic baryta paper, glass plates, etc.

Further, the heat-developable photosensitive material to which the phenol derivative according to the present invention has been added and which has been subjected to the hardening process according to the present invention can be used immediately after image formation.
Although the background layer may be slightly colored yellow, this coloring easily disappears when left indoors or exposed to indoor light, and is not a problem.

The present invention will be specifically explained below with reference to Examples.
Of course, the present invention is not limited to these.

Example 1 A first coating dispersion consisting of the following components was dispersed in a ball mill for one turn and coated onto photographic base paper using a roll coater so that the dry weight was 7 coats/coat.

First coating liquid Silver behenate 17 Silver behenate
13 Polyvinyl Butyral 40 Tatoluene 350' Etanol 350 Z Further, a second coating liquid consisting of the following components was applied using a roll coater so that the dry coating weight was 3.5 mm and dried. .

Second coating liquid 2,2-methylenebis(6-tertiarybutyl-4-methylphenol) 50% Phthalazinone 15% Exemplified Compound 1} 1.972 Sensitizing dye *9 out of 10 Polyvinyl butyral 10 Taetanol 100.

Sh*3-ethyl-5-[(3-methyl-2-thiazolinidene)ethylidene] rhodanine The heat-developable photosensitive material A obtained by the above method was heated at 100°C using a heating roller.
Pre-heat treatment for 5 seconds, use a 150W tungsten lamp for enlargement as a light source, and use a 1-sunama, light butterfly (
Kodak step tablet material. Stepwise exposure was applied in step 2), followed by heat development at 12,000 for 5 seconds.

As a result, an image of black on a pale yellow background was obtained, which was negligible. In addition, as a control experiment, a heat-developable photosensitive material A' containing no compound according to the present invention was prepared with the above-mentioned second coating liquid composition, and the same treatment as for A was performed.
As a result, a black image on a white background was obtained. The table below lists the relative sensitivity, maximum concentration and Cap IJ concentration results obtained.

Example 2 In the description of Example 1 above, 160 o of mercuric acetate, which is used as a fog suppressant for heat-developable photosensitive materials, was added to the second coating solution, and the above-mentioned exemplary compound of the present invention was added. example(
A heat-developable photosensitive material B containing 1' and a heat-developable photosensitive material B' not containing the compound according to the present invention were prepared, and the same treatments as in Example 1 were carried out.

Even when used in combination with a fog suppressant, the sensitizing effect of the present invention was not affected by the window, and the results shown in the table below were obtained. Example 3 In the description of Example 2, the exemplified compound example '11
Instead, heat-developable photosensitive material C was prepared using the above-mentioned Exemplified Compound Example '31, and heat-developable photosensitive material D was prepared using the above-mentioned Illustrated Compound Example '6}, which did not contain the compound according to the present invention. A comparison was made with the thermophenomenal photosensitive material B'.

The results are shown in the table below. The inoculation method has been effectively applied to those implementing the present invention. Example 4 A first coating liquid consisting of the following components was dispersed in a Terama ball mill and applied to photographic base paper using a roll coater so that the dry coating weight was 7 mm/day. .

First coating solution Silver behenate 17 Benhenic acid 13 Mercury mercuric acetate 0.12 Potassium bromide 0.3 Polypynyl butyral 40 Tatoluene 35
Further, a second coating liquid consisting of 0 Kikonor 350 and the following components was applied using a roll coater so that the dry coating weight was 2 mm.

Second coating liquid 2,2-methylenepis (6-tert-butyl-4-methylphenol) 50 tafthalazinone 15 The above-mentioned exemplified compounds Example [1} 1.97 sensitizing dye* 1ow3 Polyvinyl butyral 10 Taethanol
-.

〇. *3-Ethyl-5-[(3-methyl-2-thiazolinidene)ethylidene] rhodanine The heat-developable photosensitive material E obtained as above was heated at 800 lux using a 150W tungsten lamp for enlarging as a light source. 1-cho Sunama,
Kodak Step Tablet M. 2 was used to give stepwise exposure, and then heat development was carried out at 120° C. for 5 seconds.

In addition, as a control experiment, a heat-developable photosensitive material E' containing no compound according to the present invention was prepared, and the same treatment as that for E was carried out. As a result, the results shown in the table below were obtained. In this case as well, those implementing the invention are advantageously benefited.

Example 5 The heat-developable photosensitive material B obtained in Example 2 was left on the floor for a day and night after image formation, and the results were compared with the material after image formation, as shown in the table below. .

After the image was formed, it was left in a lighthouse for a day and night, and the pale yellow background that appeared immediately after the image was formed completely disappeared and turned white, while the image area was not affected in any way, as shown in the table above. The contrast has further increased. Example 6 The heat-developable photosensitive material B obtained in Example 2 was exposed to room light for 5 minutes after image formation, and compared with that immediately after image formation, the results shown in the table below were obtained. Ta.

The light yellow color of the background that appeared immediately after image formation completely disappeared and became white, while the image area was not affected at all, and as a result, the contrast was further increased as seen in the table above.

Claims (1)

[Scope of Claims] 1. In a heat-developable photosensitive material comprising at least one layer containing a) a reducible organic silver salt b) a reducing agent formed on a support, at least one of the layers A heat-developable photosensitive material characterized in that each layer contains at least one phenol derivative represented by the following general formula. General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. represent. [In the formula, R_1 represents a hydrogen atom or an alkoxy group,
R_2 represents a linear or branched alkyl group, a substituted or unsubstituted aryl group, or an aralkyl group. The thermophenomenal photosensitive material according to claim 1, which is a compound represented by the following. 3. The thermophenomenal photosensitive material according to claim 2, wherein the phenol derivative is a compound represented by the formula ▲ Numerical formula, chemical formula, table, etc. ▼. 4. The thermophenomenal photosensitive material according to claim 2, wherein the phenol derivative is a compound represented by the formula ▲ Numerical formula, chemical formula, table, etc. ▼. 5. The thermophenomenal photosensitive material according to claim 2, wherein the phenol derivative is a compound represented by the formula ▲ Numerical formula, chemical formula, table, etc. ▼. 6. The heat-developable photosensitive material according to claim 1 or 2, wherein the reducible organic silver salt is a long-chain fatty acid silver salt having 12 to 24 carbon atoms. 7. The heat-developable photosensitive material according to claim 6, wherein the organic silver salt to be reduced is behenic acid silver salt.