Radiation imagery chemistry: process – composition – or product th – Retrieving image made using radiation imagery
Reexamination Certificate
2001-06-22
2004-12-07
McPherson, John A. (Department: 1756)
Radiation imagery chemistry: process, composition, or product th
Retrieving image made using radiation imagery
C430S350000, C430S510000, C430S517000, C430S619000
Reexamination Certificate
active
06828070
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a photosensitive material having a colored layer, which exhibits an excellent stability even under hard storage conditions, and can be easily decolored if necessary. The present invention also relates to a method for forming an image using the photosensitive material.
In photosensitive materials, a photosensitive silver halide emulsion layer, etc. is often colored so that the photosensitive material absorbs a light of a particular wavelength.
For example, to control a light to be irradiated to the silver halide emulsion layer with respect to a spectral composition, a colored layer is disposed farther from a substrate than the silver halide emulsion layer. Such a colored layer is called a filter layer. In the case of a photosensitive material comprising a plurality of silver halide emulsion layers such as a multi-layered color photosensitive material for photographing, the filter layer may be disposed between the silver halide emulsion layers.
A scattered light, which is generated while or after an incident light passes through the silver halide emulsion layer, is often reflected at the interface between the silver halide emulsion layer and the substrate, or at the back surface of the substrate. When the reflected light is introduced into the silver halide emulsion layer, image ambiguity, so-called halation, is often caused. To prevent the halation, the colored layer may be disposed between the silver halide emulsion layer and the substrate or on the back surface of the substrate. Such a colored layer is called an antihalation layer. In the case of a photosensitive material comprising a plurality of silver halide emulsion layers, the antihalation layer may be disposed between the silver halide emulsion layers.
The colored layers are needed only in an exposing process, and thereafter become useless. Particularly, in the case where an image information provided on the photosensitive material is read by a scanner and where the colored layer has an absorption wavelength overlapping with the scanning wavelength, the image information is inevitably made high in density, resulting in a noisy image. Thus, it is preferable that the color density of the colored layer is reduced at least to some extent after the exposing process.
The colored layer in conventional wet-processing type photosensitive materials can be decolored by a liquid treatment after the exposure. However, dry-processing type photosensitive materials cannot be subjected to the liquid treatment, thus, some proposals have been made for decoloring the colored layer in the dry-processing type photosensitive materials, for example:
(1) methods of using a colored layer comprising a heat-decoloring dye described in U.S. Pat. Nos. 3,769,019, 3,821,001, 4,033,948, 4,088,497, 4,153,463 and 4,283,487, Japanese Patent Laid-Open Nos. 52-139136, 53-132334, 54-56818, 57-16060 and 59-182436, etc., or a dye which is decolored by a corrosive gas generated from a counter salt under a heating condition described in U.S. Pat. No. 4,347,401, etc.;
(2) methods of using a colored layer comprising a thermally carbanion-generating agent and a dye to decolor the colored layer by heating, described in U.S. Pat. Nos. 5,135,842, 5,258,274, 5,314,795, 5,324,627 and 5,384,237, European Patent No. 605286, Japanese Patent Laid-Open Nos. 6-222504 and 7-199409, etc.;
(3) methods of using a colored layer comprising a photo-decoloring dye such as an o-nitroarylidene dye and an o-nitro-o-azarylidene dye described in U.S. Pat. No. 3,984,248 and Japanese Patent Laid-Open No. 54-17833, an N—O bond-cleavable dye described in U.S. Pat. No. 3,770,451, a chrominium type cyanine dye described in Japanese Patent Laid-Open No. 2-229864, an anionic dye having an indonium counter ion described in Japanese Patent Laid-Open No. 59-164549, etc.; and
(4) methods of using a colored layer comprising a photosensitive halogen compound described in Japanese Patent Laid-Open Nos. 57-20734 and 57-68831, an azide compound described in Japanese Patent Laid-Open No. 63-146028, a ketone-based sensitizing compound described in Japanese Patent Laid-Open No. 50-10618, a meso ionic compound described in U.S. Pat. No. 4,548,895 or an indonium compound described in U.S. Pat. No. 4,701,402, and a dye which is decolored by reacting with active species generated by light-irradiating and/or heating these compounds, or by interacting with exited derivatives of these compounds.
In the methods of (1) and (2), the colored layer is decolored by heating, thus, the colored layer is easily decolored during thermal development. However, the colored layer used in the methods of (1) and (2) may be decolored during storage so that there is a case where it cannot act in the exposure process. For example, the photosensitive material for photographing is often stored under such a hard condition as in a car in the middle of summer, whereby there is a fear that the colored layer of the photosensitive material for photographing is decolored by the high temperature condition.
In the methods of (3) and (4), the colored layer is decolored by light. However, because decoloring in the methods of (3) and (4) demands a large amount of radiant ray, thermal developing photosensitive layer may be color-changed and long period of time is needed in decoloring the colored layer.
OBJECT AND SUMMARY OF THE INVENTION
An object of the present invention is to provide a photosensitive material having a colored layer, which exhibits an excellent stability even under hard storage conditions, and can be easily decolored if necessary. Another object of the present invention is to provide a method for forming an image using the photosensitive material.
As a result of intense research in view of the above objects, the inventor has found that a reversibly decolorable colored layer that is reversibly colored and decolored at particular temperature exhibits an excellent stability even under hard storage conditions and can be easily decolored if necessary. The present invention has been accomplished by the finding.
Thus, a photosensitive material of the present invention is such that comprises a substrate and a reversibly decolorable colored layer disposed thereon, wherein the reversibly decolorable colored layer is reversibly colored and decolored, the reversibly decolorable colored layer is in a colored state at 25° C., and a temperature at which the color density of the reversibly decolorable colored layer is reduced to 50% based on that at 25° C. is 50 to 120° C. Hereinafter, this temperature of 50 to 120° C. is referred to as “decoloration initiation temperature.” The reversibly decolorable colored layer used in the photosensitive material of the present invention is in a colored state around ordinary temperature at which the photosensitive material is used, thereby sufficiently acting as a filter layer, a antihalation layer, an irradiation-preventing layer, etc. In the case where the photosensitive material is stored under a high temperature condition, the reversibly decolorable colored layer may be decolored during the storage. Even in this case, the reversibly decolorable colored layer can be easily re-colored to exhibit its functions when the photosensitive material is put into practical use at a room temperature, and the reversibly decolorable colored layer can be easily re-decolored by heating when image information provided on the photosensitive material is read by a scanner, etc.
In the photosensitive material of the present invention, the reversibly decolorable colored layer preferably comprises: an electron-donating, organic color-former; a compound having a phenolic hydroxyl group; and at least one compound selected from the group consisting of alcohols, esters, ketones and ethers. Further, the photosensitive material preferably comprises a photosensitive layer comprising a silver halide, a dye-providing compound and a binder to be used as a silver halide photosensitive material for photographing. The photosensitive layer preferably further comprises an organic sil
Ishikawa Shun-ichi
Yabuki Yoshiharu
Fuji Photo Film Co. , Ltd.
McPherson John A.
Sughrue & Mion, PLLC
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