Radiation imagery chemistry: process – composition – or product th – Thermographic process – Heat applied after imaging
Reexamination Certificate
2001-08-03
2003-11-18
Chea, Thorl (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Thermographic process
Heat applied after imaging
C430S264000, C430S351000, C430S380000, C430S543000, C430S544000, C430S552000, C430S553000, C430S554000, C430S555000, C430S556000, C430S557000, C430S558000, C430S598000, C430S607000, C430S965000
Reexamination Certificate
active
06649329
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a photothermographic material. In particular, the present invention relates to a novel photothermographic material that enables control of image color tone and reduction of silver amount to be used by forming dye images by heat development.
RELATED ART
Methods for forming images by heat development are described in, for example, U.S. Pat. Nos. 3,152,904 and 3,457,075 and D. Klosterboer, “Thermally Processed Silver Systems”, Imaging Processes and Materials, Neblette, 8th ed., compiled by J. Sturge, V. Walworthand A. Shepp, Chapter 9, p.279, (1989). Such photothermographic materials comprise a reducible non-photosensitive silver source (e.g., silver salt of an organic acid), a photocatalyst (e.g., silver halide) in a catalytically active amount and a reducing agent for silver, which are usually dispersed in an organic binder matrix. While the photosensitive materials are stable at an ordinary temperature, when they are heated to a high temperature (e.g., 80° C. or higher) after light exposure, silver is produced through an oxidation-reduction reaction between the reducible silver source (which functions as an oxidizing agent) and the reducing agent. The oxidation-reduction reaction is accelerated by catalytic action of a latent image generated upon exposure. The silver produced from the reaction of the reducible silver salt in the exposed areas shows black color and provides contrast with respect to the non-exposed areas, and thus images are formed.
A method of releasing or forming diffusible dyes imagewise by heat development and transferring these diffusible dyes to an image-receiving material was proposed. In this method, either of a negative dye image and a positive dye image can be obtained by changing the kind of dye-donating compound or the kind of silver halide to be used. Further details are disclosed in U.S. Pat. Nos. 4,500,626, 4,483,914, 4,503,137, 4,559,290, Japanese Patent Laid-open Publication (Kokai, hereinafter referred to as JP-A) 58-149046, JP-A-60-133449, JP-A-59-218443, JP-A-61-238056, EP220746A2, JIII Journal of Technical Disclosure (Kokai Giho) No. 87-6199 and EP210660A2 and so forth.
Various methods have been proposed as for methods of obtaining positive color images by heat development. For example, U.S. Pat. No. 4,559,290 discloses a method in which a so-called dye releasing redox compound (hereinafter also referred to as a DRR compound) converted into a compound of oxidized form having no dye-releasing ability is used together with a reducing agent or a precursor thereof, so that the reducing agent should be oxidized in proportion to the exposure amount of silver halide by heat development, and the compound is reduced with the remaining reducing agent not oxidized so that the compound should release diffusible dyes. Further, EP220746A and JIII Journal of Technical Disclosure (Kokai Giho) No. 87-6199 (vol. 12, No. 22,) disclose color photothermographic materials using, as a compound that releases diffusible dyes by a similar mechanism, a compound which releases diffusible dyes by reductive cleavage of N-X bond (X represents an oxygen atom, a nitrogen atom or a sulfur atom).
As a method for forming dye images for photographic materials, the method utilizing a coupling reaction of a coupler and an oxidation product of developing agent is most commonly used, and color photothermographic materials utilizing this method are described in U.S. Pat. Nos. 3,761,270, 4,021,240, JP-A-59-231539, JP-A-60-128438 and so forth. In the techniques disclosed in the aforementioned patent documents, p-sulfonamidophenol is used as a developing agent. Because, in the photosensitive materials of coupling type, the couplers do not show absorption in the visible region before development, they are more advantageous in view of sensitivity compared with the photosensitive materials utilizing the aforementioned color materials, and they are considered to have an advantage that they can be used not only as printing materials but also as image-capturing materials.
These methods for obtaining dye images by heat development are suitable for photothermographic materials utilizing thermal transfer, diffusion transfer or sublimation type thermal transfer from a photosensitive layer to an image-receiving layer. However, for obtaining dye images as photothermographic materials of monosheet type, they do not necessarily have suitable characteristics as for image-forming temperature, image stability and color tone.
In photothermographic materials, compounds called “toning agents” are added to the photosensitive materials as required, in order to improve image density of silver images, silver color tone, and heat developability.
In photothermographic materials utilizing silver salts of an organic acid, toning agents of a wide range can be used. Examples of the toning agent are disclosed in, for example, JP-A-46-6077, JP-A-47-10282, JP-A-49-5019, JP-A-49-5020, JP-A-49-91215, JP-A-50-2524, JP-A-50-32927, JP-A-50-67132, JP-A-50-67641, JP-A-50-114217, JP-A-51-3223, JP-A-51-27923, JP-A-52-14788, JP-A-52-99813, JP-A-53-1020, JP-A-53-76020, JP-A-54-156524, JP-A-54-156525, JP-A-61-183642, JP-A-4-56848, Japanese Patent Publication (Kokoku, hereinafter referred to as JP-B) 49-10727, JP-B-54-20333, U.S. Pat. Nos. 3,080,254, 3,446,648, 3,782,941, 4,123,282 and 4,510,236, British Patent No. 1,380,795, Belgian Patent No. 841,910, JP-B-1-25050 and so forth.
Specific examples of the toning agent include phthalimide and N-hydroxyphthalimide; succinimide, and cyclic imides such as pyrazolin-5-ones, quinazolinone, 3-phenyl-2-pyrazolin-5-one, 1-phenylurazole, quinazoline and 2,4-thiazolidinedione; naphthalimides such as N-hydroxy-1,8-naphthalimide; cobalt complexes such as cobalt hexaminetrifluoroacetate; mercaptanes such as 3-mercapto-1,2,4-triazole, 2,4-dimercaptopyrimidine, 3-mercapto-4,5-diphenyl-1,2,4-triazole and 2,5-dimercapto-1,3,4-thiadiazole; N-(aminomethyl)aryldicarboxyimides such as N,N-(dimethylaminomethyl)phthalimide and N,N-(dimethylaminomethyl)naphthalene-2,3-dicarboxyimide; blocked pyrazoles, isothiuronium derivatives and a certain kind of photobleaching agents such as N,N′-hexamethylenebis(1-carbamoyl-3,5-dimethylpyrazole), 1,8-(3,6-diazaoctane)bis(isothiuroniumtrifluoroacetate, and 2-(tribromomethylsulfonyl)benzothiazole; 3-ethyl-5-[(3-ethyl-2-benzothiazolinylidene)-1-methylethyli dene]-2-thio-2,4-oxazolidinedione; phthalazinone, phthalazinone derivatives and metal salts thereof such as 4-(1-naphthyl)phthalazinone, 6-chlorophthalazinone, 5,7-dimethyloxyphthalazinone or 2,3-dihydro-1,4-phthalazinedione; combinations of phthalazinone with a phthalic acid derivative such as phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid, tetrachlorophthalic acid anhydride and homophthalic acid; phthalazine, phthalazine derivatives such as 4-(1-naphthyl)-phthalazine, 6-chlorophthalazine, 5,7-dimethoxyphthalazine, 6-isopropylphthalazine, 6-isobutylphthalazine, 6-tert-butylphthalazine, 5,7-dimethylphthalazine and 2,3-dihydrophthalazine, and metal salts thereof; combinations of phthalazine or a derivative thereof and a phthalic acid derivative such as phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid, tetrachlorophthalic acid anhydride and homophthalic acid; quinazolinedione, benzoxazine and naphthoxazine derivatives; rhodium complexes that function not only as a toning agent but also as a halide ion source for the formation of silver halide at the site, such as ammonium hexachlororhodate(III), rhodium bromide, rhodium nitrate and potassium hexachlororhodate (III); inorganic peroxides and persulfates such as ammonium disulfide peroxide and hydrogen peroxide; benzoxazine-2,4-diones such as 1,3-benzoxazine-2,4-dione, 8-methyl-1,3-benzoxazine-2,4-dione and 6-nitro-1,3-benzoxazine-2,4-dione; pyrimidines and asymmetric triazines such as 2,4-dihydroxpyrimidine and 2-hydroxy-4-aminopyrimidine; azauracil and tetraazapentalene derivatives such as 3,6-dimercapto-1,4-diphenyl-1H,4H-2,3a,5, 6a-tetraazapentalene and 1,4-di(o-chlorophenyl)
Katoh Kazunobu
Oya Toyohisa
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