JP2713990B2 - Thermal development type dry silver salt composition - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to an improvement in the photosensitive characteristics of a heat-developable dry silver salt material, and particularly to an improvement in sensitivity when recording with high illuminance and short exposure. The present invention relates to a thermally developed dry silver salt material. Further, the present invention relates to a recording method using this material.

(Prior art) In place of conventional wet-type silver salt materials, heat-developable dry-type silver salt materials are simple in that the development method simply applies heat. It is used in many fields such as photographic transmission, aerial photography and microfilm. In particular, recently, lasers capable of realizing high illuminance have become widespread, and improvements in recording speed and digitization of information have been demanded, and recording materials capable of sufficiently recording even with short exposure have been demanded. Under such circumstances, this heat-developable dry silver salt material is higher than other non-silver salt recording materials, like the wet silver salt material, because it utilizes the photosensitive mechanism of silver halide. It has high sensitivity and is suitable for short exposure recording. In addition, since the heat-developable dry silver salt does not use a wet solution as compared with the wet silver salt, it does not require complicated liquid treatment, and has the advantage of being maintenance-free. As described above, although there are advantages to wet silver salts, many organic compounds, especially reducing agents
The heat-developable dry silver salt material has a drawback that raw film stability is poor because it is packed in a sheet. In order to improve the raw film stability of the heat-developable dry silver salt material, research was promoted and put to practical use.However, as a result of the improved raw film stability, sensitivity was reduced, and in particular, high illuminance failure was observed. It has grown big.

Representative examples of the heat-developable dry silver salt composition include JP-B-43-4924, JP-A-48-97523, and JP-A-5-97523.
No. 3-114419.

In response to these materials, recent information recording methods are represented by an image forming method using a so-called scanner method of exposing a recording material based on an information signal to form a negative image or a positive image, an optical disk, and the like. The digital recording system has appeared. There are various types of recording apparatuses, and examples of the exposure light source include a glow lamp, a xenon lamp, a mercury lamp, a light emitting diode, a He-Ne laser, an argon laser, a He-Cd laser, and a semiconductor laser. In addition, typical examples of recording materials used in this field include wet silver salt materials, heat-developable dry silver salt materials, selenium / cadmium sulfide, photoconductor materials such as OPC, and many other materials such as photopolymers. Can be done. However, as a recording material such as a laser, a silver salt material is most useful as a material which records in an optical mode and has a large amplification coefficient, and there are many documents and books relating to these recording methods and recording materials. One example is the "Society for Promoting Science", "Recording Materials and Photosensitive Resins" (Academic Publishing Center).

As described above, the recent information recording methods are notable for analog recording and digital recording, such as improvement in recording speed and miniaturization of the apparatus. Among them, an apparatus for recording with high illuminance and short exposure using a laser or the like as an exposure light source has been commercialized. For example, a laser printer,
Laser color copying, compact disk, laser disk, laser typesetting machine, computer output, micro filmer, optical firing system, laser CAD system, etc. are being used in a very wide range of systems. Under these circumstances, there is a strong demand for materials with high illuminance and short exposure and high sensitivity. If high-sensitivity materials are supplied, industrial effects such as an increase in recording speed, miniaturization of the apparatus, and energy saving are great.

(Problems to be Solved by the Invention) As described above, when recording with high illuminance such as laser and short exposure, the sensitivity of the heat-developing dry silver salt is higher than other recording materials, but it is still unsatisfactory. Is enough. A higher sensitivity naturally leads to an improvement in recording speed and energy saving, and a reduction in the size of the apparatus is also realized.

The inventors of the present invention have attempted to increase the sensitivity by changing the composition ratio in the heat-developable dry silver salt composition and the manufacturing method of the composition in order to improve the sensitivity.
However, these changes alone seemed to reach the limit of improving the performance of the heat-developable dry silver salt composition. For example, if the sensitivity is increased, the preservability of the light-sensitive material is deteriorated, and if the preservability is to be maintained, the sensitivity cannot be increased.

(Means for Solving the Problems) Under such circumstances, the present inventors have evaluated from a wide range of perspectives, such as searching for new additives and introducing new processes, and have evaluated the characteristics. As a result of conducting an enormous number of experiments, it was found that the introduction of a certain type of new additive significantly improved the sensitivity and completed a heat-developable dry silver salt material which was sufficiently practical.

That is, it has been found that a dry silver salt material in which a heat-developing dry silver salt material contains gold atoms in an amount within a certain range has a sufficient sensitivity even with very short exposure. Further, the present invention uses this recording material to obtain 10 ³ ergs / cm ²
By writing in the optical mode under the conditions of high illuminance and short exposure of 10 ^-3 seconds or less, and then performing thermal development, recording can be practically performed by a digital recording method or the like. Also, unlike a wet silver salt composition using water as a solvent and also using only silver halide as image forming silver, an organic solvent is used as a solvent, and silver halide and an organic silver salt oxidizing agent are used as image forming silver. In the dry silver salt composition, it has been found that a trace amount of gold atoms greatly improves the properties.

That is, the present invention provides (A) an organic silver salt oxidizing agent, (A)
In a heat-developable dry silver salt composition containing a polymer compound, (c) a reducing agent and (d) silver halide or a silver halide-forming component as essential components, one silver atom in the silver salt composition On the other hand, the present invention provides a dry silver salt material characterized by containing 10 ^-3 to 10 ^-7 gold atoms.

Further, using the dry silver salt material containing the gold atom,
It is intended to provide a recording method characterized in that this material is written with an illuminance of 10 ³ ergs / cm ² or more with a short exposure of 10 ⁻³ seconds or less and heated at a development temperature of 110 ° C. or more and 140 ° C. or less.

The heat-developing dry silver salt composition used in the present invention has an organic silver salt oxidizing agent, a polymer compound, a reducing agent, a silver halide or a silver halide forming component and a gold atom as essential components,
A toning agent, a heat fogging inhibitor, a sensitizer, a spectral sensitizing dye and the like are optional components. The heat-developable dry silver salt composition as used herein may be usually either photosensitive or non-photosensitive, and is particularly preferably a non-photosensitive heat developable dry silver salt composition. The reason for this is that the non-photosensitive heat-developable dry silver salt composition usually has excellent raw film stability, but the high illuminance failure is larger than that of the photosensitive heat-developable dry silver salt composition. It is considered that this is due to the remarkable effect of the introduction.

To give examples of optional components, as a toning agent, phthalazinone or a derivative thereof, cyclic imides, uracils, oxadiones, etc., and as an antifoggant, mercury acetate,
Mercury ions such as mercuric halides, zinc acetate, calcium acetate, rosin, phthalic acid and the like are used as organic amides such as formamide, N, N-dimethylformamide, tetramethylurea, N-methyl-2- Pyrrolidone, nicotine amide, butyrolactone, 1-vinyl-
2-pyrrolidone and the like, as spectral sensitizing dyes cyanine,
Merocyanine, styrylquinoline, rhodacyanine dyes and the like.

As the organic silver salt oxidizing agent as an essential component, a silver salt of a long-chain fatty acid, for example, a silver salt of stearic acid or a silver salt of behenic acid is particularly useful. However, other non-photosensitive silver salts such as silver succinate, silver benzotriazole and the like can also be used.

Examples of the polymer compound in the present invention include polyvinyl butyral, polymethyl methacrylate, polyvinyl formal, cellulose acetate, cellulose butyrate, polystyrene, and vinyl chloride / vinyl acetate copolymer.

Examples of the reducing agent in the present invention are inhibitory phenols in which a sterically bulky group is bonded to a carbon adjacent to a carbon to which a hydroxyl group is bonded, and the hydroxyl group is sterically hindered. -T-butyl-4-methylphenol, 2,2'-methylenebis- (4-methyl-6-tert-butylphenol), 2,2'-methylenebis- (4-ethyl-6-tert-butylphenol), 2,4,4-trimethylbentylbis- (2-hydroxy-3,5-dimethylphenyl) -methane, 2,5-di-t-butyl-4-methoxyphenol and the like can be mentioned. Also, reducing agents for silver salts such as hydroquinone, 2,5-dimethylhydroquinone, chlorohydroquinone, p-aminophenol, methylhydronaphthalene, phenidone, methyl gallate,
p-Phenylphenol, bisphenol A, 2,4-dihydroxybenzoic acid, p-methoxyphenol can also be used.

Silver halide or silver halide forming components include silver chloride, silver bromide, silver iodide, iodine, calcium iodide, barium iodide, rubidium iodide, cesium iodide, aluminum iodide, magnesium iodide, iodine Such as sodium bromide and the corresponding bromide, chloride,
Examples include ionizable organic halogen compounds, nonmetal halide compounds, and halogen-containing organic metals. Representative examples of the heat-developing dry silver salt composition include JP-B-43-4924, JP-A-48-97523,
JP-B-52-17415, JP-B-53-2687, JP-B-59-2895 and the like can be mentioned.

The amount of the essential components of the heat-developable dry silver salt composition is such that the polymer compound is in a weight ratio to the organic silver salt oxidizing agent of about 10: 1 to about 1:10, preferably about 4: 1 to about 1:10. One to four,
The reducing agent varies depending on the type of reducing agent and the like, but is generally about 0.01 mol to about 10 mol, preferably about 0.1 mol to about 3 mol, per 1 mol of the organic silver salt oxidizing agent. The silver or silver halide forming component is an organic silver salt oxidizing agent 1
It is preferably from 0.01 mol to 0.5 mol per mol.

In the present invention, the term "silver atom" refers to silver contained in an organic silver salt oxidizing agent and silver contained in silver halide or a silver halide-forming component. Gold atoms are gold atoms, gold ions,
Any form such as a gold complex, a gold complex ion, and a gold compound may be used, and typical examples include a gold atom, a gold ion, a gold chloride ion, a gold thiocyanate ion, and a gold thiosulfate ion. It is important that the heat-developable dry silver salt material contains 10 ^-3 to 10 ^-7 gold atoms per silver atom, and it is particularly preferable to select a silver atom in the range of 10 ^-4 to 10 ^-6. preferable.
If the content of gold atoms exceeds 10 ^-3 , strong fog will occur after thermal development, which is not preferable.If the content is less than 10 ^-7 , the sensitivity is the same as that of a heat-developable dry silver salt material containing no gold atoms. No increase in sensitivity, which is an effect of the invention, is observed.

Usually, in the case of a non-photosensitive heat-developable dry silver salt composition, a photoreactive organic halogen oxidizing agent is an essential component in addition to the above essential components. Suitable for the present invention are halogen compounds capable of generating halogen free radicals upon irradiation with light. Preferred as such a halogen compound is a halogen compound in which a carbon atom and a bromine atom or an iodine atom are bonded. Preferred are α, α, α ',
α′-tetrabromo-o-xylene, α, α, α ′,
α'-tetrabromo-m-xylene, 1,1,1-tribromo-p-bromotoluene, 1,1,1-tribromo-2,2-diphenylethane, 2,2,2-tribromoethanol, meso-1, 2,3,4-tetrabromobutane and the like can be mentioned. As a typical example of a non-photosensitive dry silver salt composition,
JP-A-48-97523, JP-B-53-2687, JP-B-53-41967, JP-A-48-51626, and JP-A-53-216.
-114419, JP-A-53-114420 and the like.

In the heat-developable dry silver salt composition, the essential and optional components are usually dispersed and dissolved in an organic solvent, and coated on a support. As the organic solvent to be used, toluene, methyl ethyl ketone, acetone, methanol,
It is sufficient that ethanol, isopropanol, hexane, dioxane, tetrahydrofuran, etc. have a boiling point of 150 ° C. or lower.

Further, as described above, the light source of the short exposure used in the present invention includes a glow lamp, a xenon lamp, a mercury lamp, a light emitting diode, a He-Ne laser, an argon laser, a He-Cd laser, a semiconductor laser, and the like. . These light sources can easily achieve high illuminance of 10 ³ ergs / cm ² or more. At illuminance less than 10 ³ ergs / cm ² , the sensitivity improvement is not significant. It is difficult to define an upper limit, which can be reached until the composition deteriorates. As an example of a method of making the short exposure, a gas laser such as a He-Ne laser achieves a short exposure of 10 ^-3 seconds or less by passing the laser light through an optical component such as an AO modulator that serves as a shutter. You. In addition, since a semiconductor laser has an on-off function itself, short exposure can be easily achieved. In the present invention, the sensitivity is remarkably improved by a short exposure of 10 ⁻³ seconds or less, and preferably 10 ⁻⁹ seconds to 10 ⁻⁵ seconds. Realization of short exposures of 10 ^-10 seconds or less is difficult with current technology.

The development method may be any type as long as it is heat development, and includes direct heating typified by heating on a hot plate, heating in silicon oil, indirect heating typified by heating with hot air, and the like. . If the temperature is lower than 110 ° C., an image cannot be formed. If the temperature exceeds 140 ° C., fogging of the image occurs, which is not practical. In particular, it is preferable to select the temperature between 120 ° C and 140 ° C.

For the measurement of the optical density, a density measuring device equipped with a tungsten halogen lamp as a light source, a ratten # 106 as a filter, and a circular 1 mm aperture was used. The measured value of the diffuse permeability conforms to the US ANSI standard PH2.19-1959.

The terms `` illuminance '', `` high illuminance '', and `` high illuminance failure '' used in the present invention are generally used as photographic technical terms, and `` illuminance '' is the amount of energy ergs / unit area in the present invention. It refers to cm ^2.

Next, the present invention will be described in more detail with reference to examples, but these examples do not limit the scope of the present invention.

Example 1 First, a dry silver salt composition solution 10 having the following component ratio was prepared.

Silver behenate 2 g Polyvinyl butyral resin 1.5 g Calcium iodide 10 mg Sodium bromide 50 mg Phthalazinone 1 g 2,2'-methylenebis- (4-ethyl-6-tert-butyl-phenol) 2.3 g Quinoline 0.7 g N-methylpyrrolidone 1 g Methyl ethyl ketone 25g Toluene 9g Mercury acetate 0.5mg Methanol 3g Sensitizing dye 0.2mg Sodium tetrachloroaurate (III) described in Table 1 Mix all of the above components in a dark room and stir well at 23 ° C for about 2 hours. After that, the coating solution was kept constant at 23 ° C. Next, this coating solution was dried at 65 ° C. on a polyethylene terephthalate film having a thickness of about 100 μm with a reverse roll coater, and the film thickness became 10 μm.
m was applied. Application and drying were performed under safety light. The recording was performed using a He-Ne laser of 2 mW, under the conditions that the energy of the photosensitive material surface was 3.7 × 10 ⁷ ergs / cm ² and the exposure time was 2.5 × 10 ⁻⁶ seconds. After exposure, 125 ℃
The heating on the hot plate was performed in 5 seconds.

From the above results, it can be seen that, according to the present invention, when the heat-developable dry silver salt composition contains gold atoms, the sensitivity is dramatically improved.

Example 2 First, about 10 dry silver salt composition solutions having the following component ratios were prepared.

Silver behenate 2 g polyvinyl butyral resin 1.6 g barium iodide 90 mg phthalazinone 0.4 g 2,2'-methylenebis- (4-ethyl-6-tert-butyl-phenol) 1.5 g quinoline 0.8 g α, α, α ', α' -Tetrabromo-o-xylene 0.7 g N-methylpyrrolidone 1 g Methyl ethyl ketone 25 g Toluene 9 g Mercuric acetate 4 mg Methanol 3 g Sensitizing dye solution 0.2 mg Sodium tetrachloroaurate (III) Table 2 After sufficiently stirring at 22 ° C. for about 2 hours, the coating solution was kept constant at 22 ° C. Next, this coating solution was coated on a polyethylene terephthalate film having a thickness of about 100 μm with a reverse roll coater to a thickness of about 9 μm after drying.
The first layer was applied such that

Next, a second layer constituting liquid having the following component ratio was uniformly applied so that the film thickness after drying was about 7 μm, and a dried and wound roll film was used.

Second layer component liquid phthalazinone 1.3 g 2,2'-methylenebis- (4-methine-6-tert-butyl-phenol) 4 g polymethyl methacrylate 5.8 g methyl ethyl ketone 70 g The gold atom is sodium tetrachloroaurate (III). First layer included. As a recording method, an experiment was performed using a He-Ne laser of 2 mW at an energy of 8.1 × 10 ⁸ ergs / cm ² and an exposure time of 1 × 10 ⁻⁷ sec. However, since the heat-developable dry silver salt composition of this example is usually a non-photosensitive film, it was preheated at about 100 ° C. for 3 seconds before exposure. Development condition is 1
Heating was performed on a hot plate at 30 ° C. for 4 seconds.

From the above results, it can be seen that the present invention dramatically improves the sensitivity when the heat-developable dry silver salt composition contains gold atoms.

Example 3 In the same manner as in Example 2, a heat-developable dry silver salt film was prepared. However, in this example, since a 3 mW semiconductor laser having a wavelength of 780 nm was used as an exposure source, di-ethylthiatetracarbocyanine bromide having a sensitivity of 780 nm was used as the sensitizing dye of the first layer. The introduction of gold atoms was performed with sodium gold thiocyanate. Gold atoms were tested at a ratio of 2.3 × 10 ⁻⁵ to silver atoms. The developing method is the same as in Example 2.

In this example, the OD value as an index of the sensitivity was measured by changing the exposure time. The illuminance was also changed so that the irradiation energy was constant. Table 3 shows the results.
As can be seen from Table 3, when the exposure time is long (Experiment Nos. 1 to 3), the increase in sensitivity due to the addition of gold is negligible, but when the exposure time is short, the sensitivity is significantly increased due to the addition of gold. It can be seen that the illuminance failure was significantly improved.

From the results of Example 3 above, with a short exposure of 10 ^-3 to 10 ^-9 seconds,
The benefit of the thermally developed dry silver salt composition containing gold atoms has been clarified. As described above, at the present stage, short exposure of 1 × 10 ⁻⁹ seconds or less is very difficult with the current technology.

Example 4 A heat-developable dry silver salt film was prepared in the same manner as in Example 2. The amount of gold atoms is 2.3 × 10 ^-5 with respect to silver atoms. The used light source and the like are the same as in the second embodiment.

From the results of Example 4 above, the developing temperature was 110 ° C. or more to 1
It turns out that 40 degreeC or less is preferable. The development time is
If the time exceeds 1 minute, it is practically difficult. If the time is shorter than 1 second, unevenness of an image becomes severe and the image cannot be put to practical use.

(Effects of the Invention) If the recording method of the present invention is used to record on the heat-developable dry silver salt material of the present invention, the sensitivity is dramatically improved, so that the writing speed can be increased and the recording energy can be saved. And a reduction in the size of the device. Laser printer, write-once optical disk, optical tape, optical card,
Applications such as COM (computer output microfilmer), transmission photography, and laser photography are considered.
The industrial effect is great.

Claims (2)

(57) [Claims] 1. A heat-developable dry silver salt comprising (a) an organic silver salt oxidizing agent, (a) a polymer compound, (c) a reducing agent, and (iv) silver halide or a silver halide-forming component as essential components. In the composition, gold atoms were added to 1 of all silver atoms in the silver salt composition.
A dry silver salt material characterized by containing 10 ^-3 to 10 ^-7 . 2. A heat-developable dry silver salt material according to claim 1, which is written with a high illuminance of 10 ³ ergs / cm ² or more and a short exposure of 10 ^-3 seconds or less, at a developing temperature of 110 ° C. to 140 ° C. A recording method characterized by heating below.