Radiation imagery chemistry: process – composition – or product th – Thermographic process – Heat applied after imaging
Reexamination Certificate
2002-07-11
2004-03-02
Chea, Thorl (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Thermographic process
Heat applied after imaging
C430S021000, C430S531000, C430S619000, C430S621000, C430S600000, C430S613000, C430S945000
Reexamination Certificate
active
06699649
ABSTRACT:
The present invention relates to a silver salt photothermographic dry imaging material, and an image recording method as well as an image forming method using the same.
FIELD OF THE INVENTION
Heretofore, in the medical and graphic arts fields, effluent resulting from wet processing for image forming materials has caused problems with workability. In recent years, from the viewpoint of environmental protection as well as space saving, a decrease in said processing effluent has bee increasingly demanded.
As a result, there have been demanded techniques relating to photothermographic materials which allow to be effectively exposed employing laser imagers and laser image setters, and can form clear black-and-white images exhibiting high resolution.
Such techniques are described in, for example, U.S. Pat. Nos. 3,152,904 and 3,487,075 of D. Morgan and B. Shely, and D. H. Klosterboer et al., “Dry Silver Photographic Materials”, (Handbook of Imaging Materials, Marcel Dekker, Inc. page 48, 1991). Also known are silver salt photothermographic dry imaging materials (hereinafter occasionally referred to as light-sensitive materials) comprising a support having thereon organic silver salts, light-sensitive silver halide and reducing agents. Since solution-based processing chemicals are not completely employed for said silver salt photothermographic dry imaging materials, it is possible to provide customers with a system which is simpler and has less adverse impact on environment.
These silver salt photothermographic dry imaging materials are characterized in that light-sensitive silver halide grains, which are incorporated in a light-sensitive layer, are utilized as a photo-sensor and images are formed in such a manner that silver halide grains are thermally developed, commonly at 80 to 140° C., utilizing said incorporated reducing agents while using organic silver salts as a supply source of silver ions, and fixing need not be carried out.
However, said silver salt photothermographic dry imaging materials tend to result in fogging during storage prior to thermal development, due to incorporation of organic silver salts, light-sensitive silver halide grains and reducing agents. Further, after exposure, thermal development is carried out commonly at 80 to 250° C. followed by no fixing. Therefore, since all or some of the silver halide, organic silver salts, and reducing agents remain after thermal development, problems occur in which, during extended storage, image quality such as silver image tone tends to vary due to the fact that metallic silver is created by heat as well as light.
Techniques, which overcome these problems, are disclosed in Japanese Patent Publication Open to Public Inspection Nos. 6-208192 and 8-267934, U.S. Pat. No. 5,714,311, European Patent No. 1096310, and references cited therein. These techniques disclosed therein exhibit some effects, but are not sufficient to meet the market's requirements.
On the other hand, demanded as so-called “everlasting objectives” is further improvement of image quality. Specifically, in the medical image field, demanded is improvement of image quality which makes more accurate diagnosis possible. In particular, wide dynamic range materials have been demanded which can meet various diagnostic needs.
In addition, in order to decrease material cost, as well as to enhance productivity, a decrease in silver coverage is demanded. However, it is not preferable to simply decrease the silver coverage since the resultant image density decreases. In order to minimize the decrease in density at a relatively low silver amount, it is effective to increase the number of developable points per unit area so as to enhance covering power. Heretofore, in light-sensitive materials for graphic arts, techniques have been perfected which make it possible to achieve high image density at a relatively low silver amount and increasing covering power, utilizing “infectious development” employing nucleating agents (described in Japanese Patent Publication Open to Public Inspection (PCT Application) Nos. 10-512061 and 11-511571). However, light-sensitive materials, which are comprised of conventional nucleating agents known in the art, as well as conventional silver ion reducing agents known in the art, have caused problems in which storage stability is degraded and diagnostic properties are deteriorated due to yellow tinting.
SUMMARY OF THE INVENTION
From the viewpoint of the foregoing, the present invention was achieved. An object of the present invention is to provide a silver salt photothermographic dry imaging material which exhibits excellent pre-exposure storage stability, irrespective of high sensitivity as well as low fogging, and further exhibits excellent stability of silver images after thermal development, a wide dynamic range, high maximum density, irrespective of a low silver amount, and desired silver image tone, and an image recording method, as well as an image forming method of the same.
The aforesaid object of the present invention was achieved employing the means described below.
1. A photothermographic imaging material comprising a support having thereon a photosensitive layer comprising a photosensitive silver halide, a light-insensitive organic silver salt, a binder, and a reducing agent for silver ions,
wherein the reducing agent is represented by the following Formula (S):
wherein Z is a group of atoms necessary to form a non aromatic ring of 3 to 10 members; Rx is a hydrogen or an alkyl group; each Ro′ and Ro″ is independently a hydrogen, an alkyl group, an aryl group, or a heterocyclic group; Qo is a substituent; and each n and m is independently an integer of 0 to 2; and plural Qos may be the same or different.
2. The photothermographic imaging material of item 1,
wherein the reducing agent is represented by the following Formula (T):
wherein Q
1
is a halogen, an alkyl group, an aryl group or a heterocyclic group; Q
2
is a hydrogen, a halogen, an alkyl group, an aryl group or a heterocyclic group; G is a nitrogen or a carbon; ng is 0 when G is a nitrogen and ng is 0 or 1 when G is a carbon; Z
2
is a carbon or a group of atoms necessary to form a non aromatic ring of 3 to 10 members with G; and each Ro′, Ro″, Rx, Qo, n and m is the same as used in Formula (S).
3. The photothermographic imaging material of item 1,
wherein the reducing agent has a 6 membered non aromatic ring.
4. The photothermographic imaging material of item 1,
wherein the photosensitive layer has a silver coverage of from 0.5 to 1.5 g/m
2
.
5. A photothermographic imaging material, comprising a support having thereon a photosensitive layer comprising a photosensitive silver halide, a light-insensitive organic silver salt, a binder, and a reducing agent for silver ions,
wherein the reducing agent is represented by the following Formula (A).
wherein X is a chalcogen or CHR, in which R is a hydrogen, a halogen, or an aliphatic group having at most 7 carbon atoms; and each R′ and R″ is an alkyl group, and
wherein the silver coverage of the photosensitive layer on the support is from 0.5 to 1.5 g/m
2
.
6. The photothermographic imaging material of item 1,
wherein the photosensitive layer has a thermal transition temperature of from 46 to 200° C. measured after the photothermographic imaging material being processed at over 100° C.
7. The photothermographic imaging material of item 1,
wherein the binder has a glass transition temperature of from 70 to 105° C.
8. The photothermographic imaging material of item 1,
wherein the light-insensitive organic silver salt is produced in the presence of a compound selected from a crystallizing retarding agent and a dispersing agent.
9. The photothermographic imaging material of item 8,
wherein the compound is an organic compound having a hydroxyl group or a carboxyl group.
10. The photothermographic imaging material of item 1,
wherein the photosensitive layer further comprises a silver-saving compound.
11. The photothermographic imaging material of item 1,
wherein the photo
Fukusaka Kiyoshi
Iwamoto Ryohei
Miura Norio
Morita Kiyokazu
Nakamura Kazuaki
Chea Thorl
Konica Corporation
LandOfFree
Silver salt photothermographic imaging material, and image... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Silver salt photothermographic imaging material, and image..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Silver salt photothermographic imaging material, and image... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3250320