JPH052215B2 - - Google Patents

Description

[Detailed description of the invention]

FIELD OF THE INVENTION This invention relates to structures for silver halide color photothermography. In other words, the present invention relates to two- or three-color separation photothermographic recording systems that utilize a particular class of leuco dyes as color formers. PRIOR ART Photothermographic imaging systems are materials that form images when imagewise exposed and then heated. Exposure to light or other electromagnetic radiation photoactivates or deactivates components of the imaging element, and subsequent heating causes imaging reactions to occur differently in exposed and unexposed areas. Silver halide photothermographic imaging materials, often referred to as "dry silver" compositions because they do not require liquid development to form the final image, have been known for many years. These imaging materials consist of a non-photosensitive reducible silver source, a photosensitive material that produces silver upon irradiation, and a reducing agent for the silver ions in the silver source. The photosensitive material is generally a photographic silver halide, which must be in catalytic proximity with the non-photosensitive silver source. Catalytic proximity refers to the close physical association of the two materials so that the reduction of the silver source can be catalyzed by the silver nuclei formed on the silver halide. When silver halide is exposed to light, small clusters of silver atoms are created. The imagewise distribution of these clusters is known as the latent image. This latent image is generally not visible by conventional means and the photosensitive product must be further processed to form a visible image. The visible image is produced by the catalytic reduction of silver ions in catalytic proximity of the nuclei of the latent image, as described above. The silver sources used in this technical field are those that contain a reducible source of silver ions. Early and still preferred sources of silver generally consist of silver salts of long chain carboxylic acids of 10 to 30 carbon atoms. The silver salt of behenic acid or a mixture of acids of similar molecular weight is primarily used. Salts of other organic acids or other organic materials such as silver imidazolate have also been proposed, and US Pat. No. 4,260,677 discloses the use of complexes of inorganic or organic silver salts as imaging materials. Chromogenic "dry silver" imaging systems are known in the photographic art. Color development is based on an oxidation/reduction reaction at elevated temperatures between an exposed fatty acid silver salt that has been halogenated and dye-sensitized to a specific wavelength and a color developer. For example, US Patent No. 3531286
No. 6,006,903 teaches the inclusion of color-forming coupling components, such as p-phenylenediamine developer and phenol or activated methylene couplers, in close proximity to the light-sensitive emulsion. J.Published in June 1978.
Research Disclosure No. 17029 by W. Carpenter and PW Rauch is a review of the prior art regarding photothermographic silver halide systems with color development. U.S. Pat. No. 4,021,240 discloses the use of a sulfonamidophenol reducing agent and 4 equivalents of a photographic color coupler in a thermographic or photothermographic emulsion to form a dye image, including a multicolor image. This is disclosed. U.S. Pat. No. 3,985,565 discloses the use of a particular class of phenolic type photographic color couplers in photothermographic emulsions to provide color images. U.S. Pat. No. 4,021,250 discloses the use of 0.0025% leucothiazine dye as a shelf life extender in a photothermographic system consisting of an organic silver salt, a catalytic amount of photosensitive silver halide, a reducing agent, and a binder. has been done. Examples disclosed therein include 1.87% chlorothymol and 0.126% chlorothymol as the imaging reactants.
% phthalazinone was used. Leucomethylene blue and thiazine dyes are known to be effective in recording systems. US Patent No.
No. 2,646,367 discloses, for example, a carbonless copying system using benzoylleucomethylene blue as a coloring agent. US Pat. No. 3,447,944 discloses a thermographic E-copy system that utilizes leucomethylene blue and its derivatives as color formers. U.S. Pat. No. 4,309,255 relates to leucomethylene blue in electrochromic recording paper. Japanese Patent Laid-Open No. 59-5239 discloses a two-sheet positive-working photosensitive heat-developable diffusion transfer structure. SUMMARY OF THE INVENTION Briefly, the present invention comprises a photosensitive and non-photosensitive silver source, an optional silver halide, a binder, an oxidizable leucophenazine or phenoxazine or phenothiazine dye, and a carboxylic acid as a development accelerator. or a single sheet negative-acting photothermographic construction having on a supporting base a photosensitive chromogenic element consisting of a Lewis acid or a Bränsted acid. Known oxidizable leucofuenazine or phenoxazine or phenothiazine are effective in the present invention. The oxidant can have a color ranging from blue-green to yellow. The photothermographic portion of the element is photosensitive and preferably has a temperature of 150-350°C (approximately 65-180°C).
by being heated to a temperature range of (e.g.
Any imageable layer or layers that are developable (on a heated drum roll or by infrared exposure) may be used. Of particular importance is a silver halide photothermographic system consisting of silver halide in a binder, a silver source material in catalytic proximity to the silver halide, and a reducing agent for silver ions. Isosystems are commonly known as "dry silver" constructs. These systems may have a single layer or multiple layers, as is well known. The chromogenic elements of this invention may be useful in two-color or three-color separation photothermographic recording systems.
In such systems, it may be necessary to provide a "barrier layer" within the topcoat layer that is impermeable to the upper adjacent color layer.
Such constructs are described, for example, in US Pat. Nos. 4,460,681 and 4,452,883. In this application "leuco dye" means a colorless or slightly colored dye that can be oxidized to a colored body; "aryl" means phenyl or naphthyl; "arylene" means phenyl or naphthylene; "lower "Alkyl" means alkyl having from 1 to 4 carbon atoms; "lower alkoxy" means alkoxy having from 1 to 4 carbon atoms; "aliphatic" means straight or branched chain hydrocarbon "Halogen" means fluorine, chlorine, bromine, or iodine; and "in combination with" means in the same layer as or in a layer adjacent to. For example, the location of the photosensitive silver halide in the photothermographic elements or compositions of the invention is such as to enable catalysis. Accordingly, the described photosensitive silver halides are combined with the described oxidation-reduction imaging formulations (i.e., an oxidant consisting of a silver salt such as silver behenate or silver stearate and a reducing agent of the invention and (development modifier) or in an adjacent layer. Details The present invention provides a single sheet negative-working phototherm comprising a silver source, optional silver halide, a leuco dye as a reducing agent for silver ions, a binder, and a development accelerator on a support base. (a) the leuco dye has the formula [wherein, X is -S-, -O-, or -NO-; each R may be the same or different and individually represents (i) halogen, (ii) unsubstituted aryl or by an alkyl group, or up to four groups selected from alkyl, alkoxy, cyano, hydroxy, halogen, nitro, mercapto, alkylsulfonyl, arylsulfonyl, and Z, where Z is as defined below. substituted such groups with the proviso that the alkyl and alkoxy groups both have 1 to 20 carbon atoms and are preferably lower alkyl and alkoxy; and (iii) Z, with the proviso that Z is

【formula】 【formula】

[Formula] − SO ₂ Q, or

[Formula], each Q may be the same or different, and individually represents (i) halogen, (ii) unsubstituted aryl or alkyl group, or alkyl, alkoxy, cyano, hydroxy, halogen , nitro, mercapto, alkylsulfonyl, arylsulfonyl, and those groups substituted with up to four groups selected from Z (where Z is as defined above), provided that none of the alkyl and alkoxy groups have 1 to 20 carbon atoms and are preferably lower alkyl and alkoxy; R' may be the same or different and individually represent hydrogen, halogen , carbon atom 1~
6 alkyl or alkoxy, or
phenazine having the following: selected from those groups substituted with up to 3 halogen atoms; L is Z or hydrogen; with the proviso that R and L together can have up to 5 carbonyl and sulfonyl groups; phenothiazine, or a phenoxazine leuco dye; and (b) the development accelerator has (i) the formula R ¹⁰ (COOH) _o , where n is an integer with a value of 1 to 4, preferably 1 to 3; R ¹⁰ is unsubstituted or at least one group selected from amino, hydroxyl, aryl, lower alkyl, lower alkoxy, cyano, sulfonyl, mercapto, nitro, halogen, and Z (where Z is as defined above) is a group substituted with: provided that when n is 1, R ¹⁰ is selected from the group consisting of alkyl, alkenyl, aryl, and phenylalkyl having up to 10 carbon atoms, and when n is 2, (ii) preferably ^halides , nitrates, sulfates, sulfonates, and carboxylic acids; Lewis acids selected from acid salts such as ammonium nitrate, alkylammonium nitrate, Ni, Zn,
nitrates of Al, Cu, and Hg, mercuric chloride, etc.; and (iii) at least one acid selected from brensted acid, preferably selected from sulfonic acids, sulfinic acids, phenols, phosphonic acids, phosphinic acids, and sulfimides. Consists of seeds. The leuco dye may have a molecular weight of up to 2000 (preferably up to 700) and the carboxylic acid may have a molecular weight of up to 500 (preferably up to 400). The preferred photothermographic construction of the present invention is of the "dry silver" type.
Chromogenic elements capable of providing images ranging from cyan to yellow (including magenta, red, violet, purple, and blue) can be of single construction, or the photosensitive layer can be combined with a leuco dye, i.e. , a two-layer structure may be used. The single layer construction must contain the silver source material, silver halide, developer, and development accelerator in the same layer. In a two-layer construction, the photosensitive layer has a topcoat layer consisting of a leuco dye and an acid material.
Dry silver two-layer constructions must contain a silver source and silver halide in one emulsion layer (usually the layer adjacent to the substrate). Other components may be present in the same layer, a second layer, or both layers. Optional additives include toning agents, coating aids, and other aids. The photothermographic color compositions of the present invention contain at least one spectrally sensitized chromogenic element of the present invention for producing monochromatic or multicolor photothermographic color records. Spectral sensitization where at least two chromogenic elements are present is characterized in that each chromogenic element is sensitized to a spectral range that differs by at least 60 nm from the other chromogenic elements, and each chromogenic layer is For a pair of colors, such as two of the colors black, yellow, red, green, blue, and purple, as long as it produces a visible dye that has a maximum absorption that differs by at least 60 nm from that of the dye produced in the dye. It is fine as long as it is something. Preferred color pairs in which the construct may be spectrally sensitized are yellow/cyan;
yellow/magenta and cyano/magenta. Preferably, a barrier polymer is provided between each pair of color forming layers that is impermeable to the solvent system of the upper color component. Such barrier polymer(s) are essential for good color separation. Tests to determine whether a barrier polymer is impermeable to the solvent of the next layer can be easily performed. Such a test is described in US Pat. No. 4,452,883, which is incorporated herein by reference. Photothermographic color constructions may be constructed from three separate monochromatic layers to provide a three-color system. Oxazine and thiazine leuco dyes for use in the present invention can be prepared by acrylation of unsaturated phenoxane or phenothiazine compounds to N-acrylated phenoxazine or phenothiazine compounds in a known manner. As is known, nitration in acetic acid gives the 3,7-dinitrophenoxazine or phenothiazine compound after recrystallization. Hydrogenation catalyzed by platinum metal yields the corresponding diamino compounds. Treatment of diamino compounds with a suitable alkylating or acylating agent in the presence of a base such as pyridine, triethylamine or sodium hydroxide at room temperature provides diamino-substituted leuco dyes. To prepare the leucophenazine dyes useful in the present invention, a phenylene diamine compound, such as N,N-dimethyl p-phenylene diamine, and an alinine compound, such as N,N-dimethylalinine, are mixed in a solvent, preferably water, in a reactor. Combine and stir preferably at room temperature. Preferably, the reaction is carried out in an acidic aqueous environment. A second alinine compound, such as 4-methylalinine, is then added to the mixture. The resulting mixture is then stirred and heated for a sufficient period of time to form the dye product in educt form. Ionizable halide salts in solution, e.g. KI,
NaCl is added to precipitate the dye product. The solution is then cooled and the dye is collected by filtration and air dried. Hydrogen leuco dyes are obtained by reduction in the presence of an aqueous reducing agent such as sodium dithionite. Leuco dyes are obtained by extraction with a non-reactive water-insoluble solvent (eg methylene dichloride) and treatment of the organic phase with a reactive halide compound (eg benzoyl chloride). In a preferred embodiment in which the photothermographic structure is of the dry silver type, the silver source material may be any material containing a reducible source of silver ions, as described above. Silver salts of organic acids, especially long-chain (10 to 30, preferably 15 to 28 carbon atoms) fatty carboxylic acids, are preferred. Complexes of organic or inorganic silver salts in which the ligand has a large stability constant for silver ions of 4.0 to 10.0 are also desirable. The silver source material should constitute about 5-70%, preferably 7-30% by weight of the imaging layer. The second layer in a two-layer construction will not affect the proportion of silver source material required in a single imaging layer. The silver halide may be any photosensitive silver halide such as silver bromide, silver iodide, silver chloride, silver bromoiodide, silver chlorobromoiodide, silver chlorobromide, etc., and it is used as a silver source material. It may be added to the emulsion layer in such a manner that it is placed in close proximity to the catalyst. Silver halide is generally present as 0.75 to 15% by weight of the imaging layer, although larger amounts up to 20% or 25% are also useful. Preferably, 1 to 10% by weight of silver halide is used in the imaging layer, most preferably 1.5 to 7.0%. If the composition has more than one color-forming element, the dye produced from the leuco dye in each color-forming layer should of course be different. It is necessary that the reflection or transmission maximum absorption differ by at least 60 nm. Preferably the absorbance maximum of the resulting dye is at least
80 or 100nm different. If three dyes are to be produced, two of them should differ by at least this minimum, and the third dye should be at least as different from at least one of the other dyes.
They should differ by 150 nm, preferably at least 200 nm or at least 250 nm. This results in a good full color gamut final image. In the present invention, the reducing agent (developer) for silver ions is the above-mentioned leucohuenazine or phenoxazine or phenothiazine dye, which reduces silver ions to metallic silver and itself becomes a colored dye. A number of representative examples of these dyes are shown in Tables 1 and 2. The reducing agent should be present as 0.1-10% by weight of the imaging layer. 2
In layer constructions, a slightly higher percentage of about 2-15% tends to be desirable when the reducing agent is in the second layer. Additional reducing agents may be useful. Conventional photographic developers such as phenidone, hydroquinone and catechol are useful in small amounts, and hindered phenol reducing agents may also be added. Leuco dyes other than those specified above (e.g. crystal violet)
may be useful as an additional reducing agent in small amounts (up to about half the amount of primary reducing agent). Toning agents such as known phthalazinone, phthalazine, etc. are not essential to the construction, but are desirable.
These materials may be present in amounts of, for example, 0.001 to 1% by weight. Binders for silver coating include gelatin, polyvinyl acetal, polyvinyl chloride, polypynylacetate, cellulose acetate, ethylcellulose, polyolefin,
Selected from well-known natural and synthetic resins such as polyester, polystyrene, polyacrylonitrile, polycarbonate, methacrylate copolymers, maleic anhydride copolymers, butadiene-styrene copolymers, and the like. When using multiple layers of simultaneous coating, the binder is selected to be compatible with the solvent used. Copolymers and terpolymers, including the above binders, are of course included in these definitions.
A preferred photothermographic silver-containing binder is polyvinyl butyral. The binder generally accounts for 20-75% by weight of each layer, preferably about 30-75% by weight of each layer.
Used in the range of 55% by weight. Development modifiers that may be useful in the present invention are defined above. The acid selected for a particular photosensitive element will depend on the activity of the leucodiazine, oxazine, or thiazine dye, ie, its susceptibility to oxidation into colored form. Leuco dyes that are more reactive require less acidic material than leuco dyes that are less easily oxidized. For example, Pergascript Turquois ^™ (a more reactive leuco dye) requires phthalic acid, while Copichem ^™ (a less reactive leuco dye) requires a more reactive acid such as 4-nitrophthalic acid. shall be. Representative preferred development modifiers are phthalic acid, benzoic acid, chlorinated and nitro-substituted benzoic acids, 1,2,4-benzenetricarboxylic acid, 2,3-naphthalenedicarboxylic acid, tetrachlorophthalic acid, 4-methylphthalic acid. , homophthalic acid, 4-nitrophthalic acid, o-phenylacetic acid, naphthoic acid, naphthalic acid, phthalic anhydride, naphthalic anhydride, tetrachlorophthalic anhydride, 3
- aromatic carboxylic acids and their anhydrides such as nitrophthalic acid; aliphatic carboxylic acids such as malic acid, chloroacetic acid, idaconic acid, tartaric acid, benzoylformic acid, thioniacetic acid; Other acidic substances such as sulfonic acids, phosphonic acids, phosphinic acids, phenols such as 2,4-dinitrophenol and 2,6-dinitrophenol and pentachlorophenol, sulfimides (e.g. saccharin); or nickel nitrate, nitric acid Lewis acids, including copper, nitrates such as mercury nitrate, zinc nitrate, aluminum nitrate, and ammonium nitrate. Sensitizing dyes useful in the present invention include a number of known compounds as well as 454 (synthesized as in U.S. Pat. No. 2,493,748). Erythrosin (manufactured by Aldrich Chemical Co., Milwaukee, WI) 563 (synthesized as in U.S. Pat. No. 3,719,495) 421 (synthesized as in US Pat. No. 3,719,495) 421 etc. The supporting base or substrate is a transparent or opaque polymeric film. Preferably it is comprised of materials such as polyesters (eg polyethylene terephthalate), cellulose esters (eg cellulose acetate, cellulose acetate, cellulose acetate propionate), polyolefins, polyvinyl resins and the like. The coating can be applied as a single layer, for example by knife coating or extrusion, and dried before applying the next layer, or each monochrome can be applied in double coats, for example by double slide coating or double extrusion. It is also possible to: i.e. each sensitized silver layer can be coated together with its respective topcoat (which may contain a barrier resin), thereby reducing the number of coater passes. I can do it. Representative examples of useful leucodiazine, oxazine, and thiazine dyes are listed in Tables 1 and 2.
D _nio for a two-layer element prepared as follows
and D _nax are shown. Silver solution Silver behenate 1.7g Toluene 9.3g Methyl ethyl ketone (MEK) 3.1g These three components were homogenized. The following were added to it separately: Toluene 71.1g Ethanol 6.5g Polyvinyl butyral resin ( ^ButvalTM B-
76, manufactured by Monsanto Corp.) 8.3 g Mixing continued until Butval was dissolved. Then 1 ml of a solution of 4.3 g of ZnCl ₂ in 100 ml of ethanol was added and mixing was continued for 1 hour. This dispersion was coated at 76μ (3
Supercalendered 691B Simpson ^MT Photographic Paper (Simpson Paper Co., Vicksburg, MI) with (mill) orifice (wet thickness)
applied on top. The coating was dried at 85°C (185°C) for 4 minutes. Preparation of Topcoat Ethanol 50.0g Acetone 42.5g Butval B-76 7.5g UV absorber ( ^CiasolveTM UV5411, manufactured by American Cyanamid) 0.1g Phthalic acid 0.5g These five components were mixed until dissolution occurred. For each individual sample (8 g) of this top coat solution,
0.05g of each of the leuco dyes listed in Tables 1 and 2 were added and mixed. All of these are
A 76 micron (3 mil) wet thickness was applied with a Bird applicator onto individual samples of the dry silver coating described above. These constructs were dried either at room temperature (21°C) for 15 minutes (Condition A) or at 85°C (185°C) for 3 minutes (Condition B). These constructs are 3M
About 3800fc by model 636 tungsten lamp
for 20 seconds and then developed in a heated blanket processor at 124°C (255°C) for the specified time.

【table】

【table】

【table】

【table】

[Table] The objects and effects of the present invention will be further explained by the following examples, but the specific materials and amounts cited in these examples, as well as other conditions and details, will unnecessarily limit the present invention. It should not be construed as something that does. The dye used in the examples has the following structure: Synthetic heliotrope B dye of leucodiazine A (Pfalz & Bauer Chemical Co., Stanford, CT) 10 g was dissolved in 250 ml of water under a nitrogen blanket. Sufficient sodium dithionite was added until the color was completely removed. 200 ml of methylene chloride was added and the solution was stirred vigorously with a mechanical stirrer. Benzoyl chloride 8
g was added and stirring was maintained for 3 hours while adjusting the pH of the aqueous phase to 10. At that point the methylene chloride phase was separated, washed with water, diluted with potassium carbonate solution and washed again with water. The solution was dried with MgSO ₄ and the solvent was removed under vacuum to obtain the crude product. This material was recrystallized from acetone to give the product Leukodiazine A. Example 1 A leucooxazine dye, Pergascript Turquoise S-2G, was tested for photothermographic imaging using a Lewis acid as a development accelerator in a silver soap system in the absence of metal halides. did. Silver soap dispersion 1A

【table】

[Table] The above solution is 240 ml filled with 12.7 mm glass beads.
Milled in a ml glass jar. Final silver soap coating solution 1B Mix the following ingredients and spread on baryta coated paper.
It was applied at 0.1016 mm (4 mil) and air dried.

TABLE Topcoat Formulations The following solutions were prepared to evaluate several acids or development modifiers. Master solution 1C

[Table] Effect of nickel nitrate 1 ml of a solution obtained by dissolving 0.1 g of nickel nitrate in 5 ml of methanol and 5 ml of N-methylpyrrolidone.
to 5 g of master solution 1C (no acid) of this example,
Also, m-nitrobenzoic acid (master solution 1C12.1
0.075 g/g) of this example master solution containing 1 C of 5 g. These coating solutions were applied onto the silver soap coating 1B at a thickness of 0.1016 mm and air-dried. The results are shown in Table 3.

[Table] Benzoic acid
30 1.5 0.42 0.76
The data in Table 3 demonstrate that nickel nitrate acts as a development catalyst without the use of additional carboxylic acid catalysts. Example 2 Silver Soap Solution 2A A halide sensitized silver soap solution was prepared using the Example 2A silver soap homogenate as follows:

[Table] This was coated at 0.0762 mm on a 0.0508 mm (2 mil) thick titanium oxide-containing polyester film and air-dried. Topcoat Master Solution 2B A topcoat master solution was prepared as follows:

[Table] Experiment using Pergascript Turquoise Then, Topcoat Master Solution 2B 10g
Purgascript Turquois S2G0.125g
was added. A developer modifier was added and the resulting solution was coated onto Silver Soap Coating 2A at 6 mils and allowed to air dry. The resulting coating was then exposed to ultraviolet light and developed at 124°C. The results are shown in Table 4.

[Table] Experiment using Copichem and Leucodiazine A. Using the same procedure, Pargascript Turquoise
Copichem or Leucodiazine A instead of S2G
We conducted an experiment using . The results are shown in Table 5.

Tables 4 and 5 demonstrate the effectiveness of various acids as development accelerators for use with oxazine, thiazine, or diazine leuco dyes in photothermographic systems containing silver halide. There is. Example 3 Silver Behenate Premix 3A 300g of Silver Behenate Half Soap was added to ethanol.
A dispersion was made by dispersing in 2696 ml and 347 ml of toluene by rapid mixing. Then, we modeled this dispersion using the Manton-Gaulin model.
15M8TBA SND homogenizer (Manton-Gaulin) with 550Kg/cm ² (8000psi) and 225Kg/cm ²
(4000 psi) for two passes. after that,
389.8 g of this material was diluted with 113 ml of ethanol.
Polyvinyl butyral polymer (Butval-B76)
The premix was completed by mixing in 34.7 g for 1 hour. Silver soap coating liquid 3B containing Pergascript Turquoise S2G and acid The effect of acid on the redox reaction between Pergascript Turquoise and silver behenate half soap was evaluated. The following formulation was used in this evaluation.

[Table] These coating solutions were applied to a thickness of 0.1016 mm on polyester containing titanium oxide (3M) with a thickness of 0.0508 mm, air-dried for 3 minutes, and further dried at 82°C (180〓) for 3 minutes. It was then administered via a serially staged tablet called “BioLite” (Allied Linn Supply, Inc., CA).
The cells were exposed to an ultraviolet light source (General Electric 15W Black Light) for 120 seconds. It was then processed in a 3M Model 70 Thermal Blanket Processor at 127°C (260°C) for 1-120 seconds. Density was measured with a Macbeth densitometer using a red filter. The acids tested are listed in Table 6 below.

[Table] Phthalic acid 4-nitrophthalic acid is mercuric chloride (0.57g/
The same test was performed by adding 3.0 ml of 5 g Ionox ^™ (R) 201 antioxidant (Siel Chemical Co.) to the test solution formulation. repeated.
These coating solutions were applied and tested in the same manner as in the previous example. The results are listed in Table 7.

[Table] 〓Ionox
201〓 in combination The data in Table 7 shows that mercuric chloride, with or without an antioxidant, can be used as a Lewis acid type development accelerator and as an antifoggant in the present invention. Silver Behenate Coating Containing Copichem and Acid The effects of various acids on the redox reaction between Copichem and silver behenate half soap were evaluated. The following formulation was used for this evaluation:

Table: These coatings were applied, dried, and processed as described in Example 3B. Acid is the 8th
listed in the table.

[Table] Phthalic acid
3.4〓Chloro 55 0.22 0.48 Green

phthalic acid
Silver behenate coating containing leucodiazine A, acid, and toning agent The effect of acid on the oxidation-reduction reaction between leucodiazine A and silver behenate half soap was evaluated. The following formulation was used in this evaluation.

Table: Solutions These coating solutions were applied, dried and processed as described in 3B. The material evaluated was the 9th
listed in the table. Measurements were performed using a green filter.

[Table] Non-phthalic acid *〓Used 1.5ml of phthalazinone (2.5g/100ml methanol) solution〓
The data in Table 9 shows that the combination of phthalazinone and phthalic acid provides higher image density than phthalic acid alone. Example 4 Evaluation of metal nitrate salts when used with leucooxazine dyes Silver Behenate Premix 4A Use of metal nitrate salts with oxazine and thiazine leuco dyes in silver behenate half-soap systems containing dye-sensitized silver halide Silver behenate premixes were prepared for use in the evaluation of Silver behenate homogenate 4A
It was used.

【table】

[Table] Sensitized silver behenate premix 4B and
4C Solution Premix 4A was halogenated and dye-sensitized to green light with the following formulation:

[Table] This coating solution was applied in a thickness of 0.0508 mm onto a 0.0508 mm thick polyester containing titanium oxide (3M), and
Dry at 77°C (170°C) for 3 minutes. This was done to evaluate metal nitrates used in top coats containing leuco dyes and phthalates and polymers.
used. Topcoat Master Solution 4D A topcoat master solution containing Pergascript Turquoise for Lewis acid (nitrate) evaluation was prepared using the following ingredients:

[Table] Dissolved.
Topcoat Solution 4E Nitrate was previously dissolved in methanol at a concentration of 1 g/100 ml. This is 2.34× per 30g of solution.
It was added to Topcoat Master Solution 4D to give an equivalent concentration of 10 ^-5 molar metal nitrate. The evaluated nitrates and their usage (mg) are shown in Table 10.

Table: These topcoat solutions were applied to the top of silver behenate coatings 4B and 4C, respectively, using a 0.1016 mm orifice setting and dried at 77°C (170°) for 5 minutes. These are sent to a xenon flash (EG&G sensitometer) via a continuous tone wedge.
It was exposed for 10 ^-3 seconds and then heat developed for 20 seconds at 124°C (255°C) in a 3M Model 70 Heated Blanket Processor. The resulting wedge was measured with a computerized densitometer using a red filter. The results are shown in Tables 11 and 12.

[Table] Minium 4 Ammonium nitrate .08 1.22 31° 174
monium

[Table] Minium 8 Ammonium nitrate .07 2.16 55° 659
Monium The data in Table 11 shows that Lewis acids (nitrates) improve the thermal reactivity of the system, giving higher image density, gamma angle, and photosensitivity. The color of the above-mentioned image was blue to cyan. Example 5 Evaluation of nickel nitrate and nickel bromide as development accelerators when used with leucothiazine dyes Sensitized silver behenate premix 5A The solution premix 4A prepared in Example 4 was halogenated with the following formulation: and dye-sensitized to green light.

[Table] Solution This coating solution was applied at a thickness of 0.0508 mm onto a 0.508 mm thick polyester containing titanium oxide, and then heated at 77°C.
(170〓) for 3 minutes. Topcoat Master Solution 5B A topcoat master solution containing Copichem for metal nitrate evaluation was prepared with the following formulation:

[Table] [Pre-dissolve Copichem in (D) before adding to (A)] Nickel nitrate evaluation Nickel nitrate and phthalic acid were pre-dissolved individually in ethanol at a concentration of 1 g per 100 ml. Then, 0.5 ml of this equal solution was added to each 22.354 g of Topcoat Master Solution 5B. Apply these top coat solutions onto the sensitized silver behenate coating 5A.
Apply with 0.1016mm orifice setting and 77℃
(170〓) for 5 minutes. They were exposed, processed and tested as in Example 4.
The results are shown in Table 13:

Table: This data represents the effectiveness of nitrates as development accelerators. Example 6 Combination of Leuco Oxazine and Thiazine Dyes with Other Leuco Dyes Topcoat Master Solution 6A To evaluate the effectiveness of the combination of Oxazine and Thiazine leuco dyes with nickel nitrate, 4
- A top coat master solution containing nitrophthalic acid and leuco crystal violet was prepared. The following formulation was used:

[Table] Pergascript Turquoise, Copichem, and nickel nitrate (manufactured by Tsuchi Chemical Co.) were pre-dissolved in a solvent and then added to 20.12 g of Example Topcoat Master Solution 4G. The following solutions were prepared:

[Table] Tanol 0.0762 of these coating solutions were applied on silver behenate coating 5A.
mm and dried at 77°C (170°) for 5 minutes. They were exposed, processed and tested as in Example 4. The results are shown in Table 14.

[Table] All images are bluish green. The data in Table 14 show that the leuco dyes of the present invention provide effective systems in combination with other leuco dyes and nickel nitrate. Example 7 Effect of Phthalazine The following formulations 7A and 7B were used to evaluate the effect of Phthalazine:

【table】

[Table] These solutions were coated onto silver behenate coating 4C to a thickness of 0.1016 mm and dried at 77°C (170°) for 5 minutes. They were exposed, processed and tested as in Example 4. The results are shown in Table 15.

Table: These samples were aged in a 2000 foot candle for 2 hours at 27°C (80°C) and 60% relative humidity. Table 15 shows the changes in D _nio .

TABLES The data in Tables 15 and 14 indicate that conventional developer modifiers used in dry silver are also effective in this system. Phthalazine reduces thermal reactivity but improves print stability. The combination of phthalazine with nickel nitrate and Pergascript Turquoise was evaluated in the following formulations.

[Table] Ethanol These solutions were coated at 0.1016 mm onto silver behenate coating 4C and dried at 77°C (170°) for 5 minutes.
They were exposed, processed and tested as in Example 4D. The results are shown in Table 17.

Table: Phthalazine The data in Table 17 shows the increased concentration and sensitivity of the nickel nitrate/phthalazine containing construct. Addition of nickel nitrate improved sensitometry without harming print stability when compared to phthalazine alone. Example 8 Acid and Oxazine Dye A cyanide-silver coating solution 8A (below) was prepared and applied to a 0.076 mm thick polyester film "Melinex ^™ " type 329 (ICI) in a laboratory manual knife coater.
It was coated at 3.6 g/m ² (0.32 g/sq ft) on top. Leucooxazine dye Pergascript
Various acids were used in constructing with TurkOis S2G.

【table】

[Table] 0.064mm (2.5mil) orifice; 82℃ (180〓)
Dry for 5 minutes. The following formulation was used to evaluate acid in the top coat over a previously applied red sensitive silver coating (8A).

[Table] Cal surfactant top coat is applied with a 0.076mm orifice,
Dry at 82°C (180°) for 5 minutes. after that,
The material was exposed to an EG&G xenon flash sensitometer for 10 ^-3 seconds. No filter was used. The samples were processed in a 3M Model 70 Thermal Blanket Processor at 124°C (255°C).
Table 20 shows the test acids together with the residence time, D _nio and D _nax .

[Table] Acid

[Table] Yellowtail
9. Satukarin 0.4 60 0.10 0.55

【table】

【table】

[Table] Monium

Table: Dicarboxylic Acids The data in Table 20 shows the effectiveness of various acids as development accelerators for use with Pergascript Turquoise S2G in color constructions. Example 9 Cyanoxazine leuco dye developer in magenta/cyan bipack Dispersion of silver behenate half soap was prepared in toluene 90%
% and 10% by weight in a mixed solvent of 10% ethanol
In the Manton-Gaulin homogenizer model
550Kg/cm ² and 225Kg/cm ² (8000psi and
4000 psi) twice.
The silver soap dispersion was then prepared for coating by adding diluting solvent, halide, polymer, and sensitizing dye at selected times and mixing sequences.

【table】

[Table] Stop mixing at 340 minutes. 90 g of the dye of Example 1 was dye sensitized with 2.7 cc of #534 dye (green sensitizer) solution at a concentration of 0.013 g/50 c.c. methanol. Apply this solution to 0.076 mm (3 mil) using a laboratory manual knife applicator.
It was applied to the top of a 0.05 mm (2 mil) thick polyester film containing titanium dioxide (3M) using an orifice. This coating was dried at 81°C (177°C) for 5 minutes.

【table】

[Table] *8.15g of 2,6-dichlorophenol in 300ml of water
and 15.9 g of sodium carbonate; then, 150 ml of chloroform was added. A solution of 65.9 g of potassium ferricyanide in 300 ml of water was added and the solution was stirred for 1 hour. Separate the chloroform phase;
Wash with 5% aqueous sodium hydroxide solution, MgSO ₄
and stripping to produce the dye. 1 g of this dye was dissolved in 200 ml of diethyl ether and 0.58 g of t-butylhydroquinone.
was added. This mixture was left for 3 hours. The ether was extracted with 5% aqueous sodium hydroxide.
The aqueous phase was separated and acidified with 10% hydrochloric acid.
A precipitate formed. The suspension was extracted with ether. Evaporation of the ether gave a pale brown material magentaloid aniline dye. This coating solution was applied to the top surface of coating 9A using a 0.076 mm (3 mil) orifice and dried at 81°C (177°C) for 5 minutes. Another dispersion of silver behenate half soap was prepared in the same manner as 9A except that a mixed solvent of 90% ethanol and 10% toluene was used.
This silver soap dispersion was used to prepare a red-sensitive coating solution for a cyan color system to be applied on top of a previously applied magenta color system.

【table】

【table】

[Table] 50g of cyanide silver premix 9C solution at a concentration of 0.017
Dye sensitization was performed with 1.2 cc of MSD563 dye (red sensitizer) solution in g/50 c.c. methanol. This was applied with a 0.05 mm (2 mil) orifice on top of the previously applied layers 9A and 9B. Paint film at 81℃ (177
〓) for 5 minutes. Cyan Color Topcoat 9D The following topcoat solution was prepared for coating on top of cyan silver premix 9C to complete the magenta/cyan color bipack.

[Table] Add this to the top surface of Cyan Silver Premix 9C at 0.1016
mm (4 mil) orifice and 81℃
(177〓) for 5 minutes. Thus magenta/
The cyan bipack was completed and had the following structure: Base - 0.05 mm thick (2 mil) _TiO2 loaded polyester first layer - Green sensitive silver second layer - Barrier polymer magenta color developer and development. Modifier Layer 3 - Red Sensitive Silver Layer 4 - Cyan color developer and development modifier in hard topcoat polymer.
(EG&G is the electro-optics division, MA
State Salem) was exposed to a xenon flash sensitometer. Latuten No.58 and Latuten No.25 were used. The exposed material was then heated to 124°C (255°C).
〓) for 20 seconds. The sensitometry of this bipack is shown in Table 18.

[Table] Image color Magenta Cyan
The data in Table 18 shows that good color separation was achieved and demonstrates the utility of the two-color system. Example 10 Example of Cyanoxazine Leuco Dye Developer in Yellow/Magenta/Cyan Tripack Next, a three-color separation system using the cyanoxazine leuco dye Pergascript Turkuose will be illustrated. Yellow Silver Coating Solution 10A This solution was prepared by adding 1.5 cc of #454 dye (blue sensitizer) solution at a concentration of 0.032 g/50 c.c. methanol to 40 g of Magenta Silver Coating 9A.
This was coated onto a 0.0508 mm (2 mil) thick polyester film with titanium dioxide (3M) using a laboratory manual knife coater with a 0.1016 mm (4 mil) orifice. The coating was dried at 81°C (177°C) for 5 minutes.

Table: Ropanol Charges B and C were mixed before being added to Charge A.

Table: Charge materials B to F were pre-dissolved in charge material A and then charge material G was added. This solution was applied to the top surface of the previously applied yellow silver coating 9A using a 0.076 (3 mil) orifice and heated to 79°C (175〓).
and dried for 5 minutes. Magenta coloring system 9A described in Example 8
and 9B were applied to the upper surface of the yellow coloring system. The resultant was exposed and processed according to the procedure of Example 9. For yellow color, Ratsuten No.
47B (blue light) was used. The sensitometry of this yellow/magenta bipack is shown in Table 19.

【table】

[Table] Image Color Yellow Magenta A cyan coloring system using Cyan Silver Premix 9C and Cyan Silver Coating Liquid 9D was applied to the top surface of Eronomagenta Bipack. Yellow, magenta and cyan sensitometry was obtained in the same manner as above. The results showed good three-color separation suitable for color reproduction. The yellow sensitometry was the same as the bipack, and the magenta and cyan were the same as disclosed in the magenta/cyan bipack. Various modifications and variations will become apparent to those skilled in the art without departing from the scope and spirit of the invention. The invention is not unnecessarily limited to the exemplary embodiments described herein.

Claims (1)

[Scope of Claims] 1. A photosensitive and non-photosensitive silver source, a binder, an oxidizable leucophenazine or phenoxazine or phenothiazine dye as a reducing agent for the silver source, and a carboxylic acid or Lewis acid as a development accelerator. or brensted acid on a supporting base, the color of the image being imparted by the oxidized form of the leuco dye, a single monochrome image capable of forming a color image. Construction for negative-acting photothermography of sheets. 2. The composition of claim 1, wherein the photosensitive silver source is silver halide. 3 (a) The leuco dye has the formula [In the formula, each R may be the same or different, and individually represents (i) halogen, (ii) unsubstituted aryl or alkyl group, or alkyl, alkoxy, cyano, hydroxy, halogen, alkyl sulfonyl, arylsulfonyl, and such groups substituted with up to 4 groups selected from Z (where Z is as defined below), provided that both alkyl and alkoxy groups are substituted with 1 to 20 groups; and (iii) Z (where Z is [Formula] [Formula] [Formula] -SO ₂ Q, or [Formula], and each Q may be the same or different) Often, individually (i) halogen, (ii) unsubstituted aryl or alkyl group, or alkyl, alkoxy, cyano, hydroxy, halogen, alkylsulfonyl, arylsulfonyl, and Z, where Z is as defined above. with the proviso that the alkyl and alkoxy groups each have from 1 to 20 carbon atoms; R' are the same; Hydrogen, halogen, carbon atoms 1 to 1, which may be present or different, individually
6 alkyl or alkoxy, or
selected from those groups substituted with up to 3 halogen atoms; X is -S-, -O-, or -NQ-; L is hydrogen or Z; provided that R and L are 5 in total; and (b) the development accelerator comprises (i) a phenazine, phenothiazine, or phenoxazine leuco dye having the formula R ¹⁰ (COOH) _o , n is an integer with a value of 1 to 4, and R ¹⁰ is unsubstituted or amino, hydroxyl, aryl, lower alkyl, lower alkoxy, cyano, sulfonyl, mercapto,
A group substituted with at least one group selected from nitro, a halogen atom, and Z (where Z is as defined above); however, when n is 1, R ¹⁰ is a group having 10 or less carbon atoms. , alkyl, alkenyl, aryl, and phenylalkyl, and when n is 2, 3, or 4, R ¹⁰ is a group consisting of alkenylene, alkylene, and arylene of up to 14 carbon atoms. (ii) Lewis acids selected from halides, nitrates, sulfates, sulfonates, and carboxylates; and (iii) sulfonic acids, sulfinic acids, phenols;
Claim 1 or claim 1, comprising at least one acid selected from phosphonic acid, phosphinic acid, and brensted acid selected from sulfimide, and the color of the image is provided by the oxidized product of the leuco dye. A binary construct. 4 The leuco dye is or The composition according to any one of claims 1 to 3. 5. The composition according to any one of claims 1 to 4, wherein the carboxylic acid is substituted benzoic acid or naphthoic acid. 6. The composition of any one of claims 1 to 5, wherein the Lewis acid is selected from nitrates of Ni, Zn, Al, Cu, Hg, and _NH4 ⁺ . 7. The composition according to any one of claims 1 to 6, wherein the color-forming element has a single layer structure. 8. The composition according to any one of claims 1 to 7, wherein the color-forming element has a two-layer structure. 9. An arrangement according to any one of claims 1 to 8, which is part of a two-color or three-color separation recording system.