Radiation imagery chemistry: process – composition – or product th – Radiation sensitive product – Two or more radiation-sensitive layers containing other than...
Reexamination Certificate
1999-09-14
2002-06-04
Schilling, Richard L. (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Radiation sensitive product
Two or more radiation-sensitive layers containing other than...
C430S512000, C430S522000
Reexamination Certificate
active
06399290
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to silver halide imaging materials and is particular to a class of compounds which are suitable for use as acutance, antihalation and filter dyes for such materials. The invention also relates to a method of preparing the aforesaid compounds.
BACKGROUND TO THE INVENTION
It is a common practice with silver halide imaging materials to colour the light sensitive photographic emulsion and/or other hydrophilic colloid layers so as to absorb light of a specified wavelength or wavelengths. For example, where it is necessary or desirable to control the spectral energy distribution of light entering the emulsion layer, a coloured layer known as a “filter layer” can be interposed between the emulsion layer and the exposure source. Where the photographic material comprises a plurality of such photographic emulsion layers, the filter layer may be interposed between successive emulsion layers.
A coloured layer may also be interposed between the photographic emulsion and the support to prevent halation. Halation, which is the spreading or blurring of the photographic image in regions of intense exposure due to the formation of a halo around the image, is caused by light reflected from an interface between two layers, such as the emulsion layer and support, the light being scattered back into the emulsion layer. The coloured layer may also be present on the reverse, uncoated side of the support to prevent the reflection of light from the surface thereof. These coloured layers are collectively referred to as “antihalation layers”. Where the photographic material comprises a plurality of emulsion layers, an antihalation layer may be interposed between every adjacent plurality of layers.
The photographic emulsion layer itself may be coloured to present any reduction in image sharpness caused by light scattering in the emulsion layer. The dyes used to colour the emulsion layer are known as “acutance dyes”.
The photosensitive emulsion and other hydrophilic colloid layers are normally coloured by the addition of a dye to the coating formulation. Such a dye desirably exhibits the following characteristics.
(1) It should have adequate spectral absorption in compliance with the intended use.
(2) It should be photochemically inert. In other words, it should not produce chemically adverse effects (e.g., decrease of sensitivity, fading of latent image and fogging) on the performance of the silver halide photographic emulsion layer.
(3) It should decolourise or dissolve in the processing solution (or water) during photographic processing and should not leave undesirable colours in the photographic light-sensitive material after being processed.
(4) It should not diffuse from the coloured layer to the other layers.
(5) It should be stable and resistant to discolouration in solution and the photographic material for extended periods of time.
It is particularly important that the dye should not diffuse from the coloured layer to adjacent layers. Otherwise, not only are those other layers subject to an adverse spectral effect, but the performance of the coloured layer itself may be markedly affected.
A number of dyes said to be suitable for use in photographic materials are known in the art, including: oxonol dyes, such as those disclosed in British Patent No. 506385 and 1278621 and U.S. Pat. Nos. 3,247,127, 2,533,472 and 3379533; hemioxonol dyes, such as those disclosed in British Patent No. 584509; styryl dyes, such as those disclosed in U.S. Pat. No. 2298733; merocyanine dyes, such as those disclosed in U.S. Pat. No. 2,493,747; cyanine dyes, such as those disclosed in U.S. Pat. No. 2,843,486, and pyrazolone dyes, such as those disclosed in U.S. Pat. Nos. 3,002,837, 3,389,994 and 4,925,782. The dyes are decolourised during processing of the exposed photographic material, typically by reaction with sulphite (or acid sulphite) contained in the developer solution and/or alkaline conditions in combination therewith, as disclosed, for example, in British Patent No. 506385.
However, as many known dyes do not generally exhibit all of the above five characteristics, there is a continuing need for dye compounds that can satisfy the aforesaid criteria.
A class of compounds has now been found which are particularly suitable for use as acutance, antihalation and filter dyes in silver halide imaging materials.
BRIEF SUMMARY OF THE INVENTION
According to one aspect of the present invention there is provided a compound comprising a nucleus represented by one of the following general formulae (I) and (II):
in which;
A and B independently represent those non-metallic atoms necessary to complete a neutral (i.e., non-charged) heterocyclic ring in which at least one ring atom is nitrogen,
R represents hydrogen or an alkyl group, and
Y represents a divalent aliphatic linking group.
The class of compounds represented by general formulae (I) and (II) absorb light in the UV/VIS (blue) region of the spectrum, particularly at wavelengths between 360 and 450 mm (inclusive). They may be incorporated into conventional silver halide photographic materials to selectively colour one or more layers of the material for acutance, antihalation and filter purposes, but without adversely affecting the photographic characteristics, especially the spectral sensitisation, of the photographic emulsion. The compounds of formulae (I) and (II) are substantive, having a reduced tendency to diffuse into adjacent layers, and are decolourisable by conventional photographic processing. The compounds of formulae (I) and (II) also show good stability and are resistant to bleaching on storage.
Therefore, according to a further aspect of the present invention there is provided a light-sensitive silver halide photographic material comprising a support having coated thereon in one or more layers a photographic silver halide emulsion, which photographic material comprises in either the silver halide emulsion layer(s) and/or an auxiliary layer as an acutance, antihalation or filter dye, a compound of formula (I) or (II).
DESCRIPTION OF PREFERRED EMBODIMENTS
The groups completed by A and B are generally 5, 6 or 7-membered heterocyclic rings, the constituent atoms of which are normally selected from C,N,O,S and Se, but with the proviso that at least one ring atom is nitrogen. The heterocyclic rings may optionally possess one or more substituents selected from alkyl groups (e.g., methyl, ethyl, isopropyl etc.), halogen atoms (e.g., fluorine, chlorine, bromine and iodine), a hydroxy group, alkoxy groups (e.g., methoxy, ethoxy etc.), aryloxy groups (e.g., phenoxy, hydroxyphenoxy etc.), amino groups (e.g., amino, methylamino, dimethylamino etc.), a cyano group, acylamino groups (e.g., acetylamino, benzoylamino etc.), diacylamino groups (e.g., succinimido etc.), ureido groups (e.g., methylureido etc.) sulphonamido groups (e.g., methanesulphonamide etc.), acyloxy groups (e.g., acetyloxy etc.), sulphamoyl groups (e.g., N-ethylsulphamoyl etc.), alkylcarbonyl groups,. arylcarbonyl groups, alkoxycarbonyl groups (e.g., methoxycarbonyl, is ethoxycarbonyl etc.), aryloxycarbonyl groups (e.g., phenoxycarbonyl etc.), alkoxycarbonyl amino groups (e.g., ethoxycarbonylamino etc.), carbamoyl groups (e.g., N-ethylcarbamoyl etc.), aryl groups (e.g., phenyl, tolyl etc.), hydroxyalkyl groups (e.g. hydroxyethyl, hydroxypropyl etc.), alkoxyalkyl groups (e.g., methoxyethyl, methoxypropyl etc.), mercapto groups, alkylthio groups, arylthio groups, alkylsulphonyl groups, arylsulphonyl groups, acyl groups, aralkyl groups, alkyl groups containing a carboxyl group (e.g., carboxymethyl, carboxyethyl etc.), each of which groups may, where appropriate comprise up to 14, preferably up to 10 carbon atoms, and those non-metallic atoms necessary to complete a fused ring substituent incorporating at least two ring atoms of the heterocyclic ring and generally comprising up to 14 ring atoms in toto.
As is well understood in this technical area, a large degree of substitution is not only tolerated, but is often advisable. As a means of simplifying the discussio
Hall Kevin P.
Mott Andrew W.
Eastman Kodak Company
Schilling Richard L.
Tucker J. Lanny
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