Radiation imagery chemistry: process – composition – or product th – Radiation sensitive product – Two or more radiation-sensitive layers containing other than...
Reexamination Certificate
1994-07-14
2002-06-25
Letscher, Geraldine (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Radiation sensitive product
Two or more radiation-sensitive layers containing other than...
C430S558000, C430S546000, C430S551000, C430S566000, C430S470000, C430S476000
Reexamination Certificate
active
06410216
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to methods for the formation of photographic color images in photographic silver halide color materials.
BACKGROUND OF THE INVENTION
Existing commercial photographic silver halide color materials form dye images by the reaction of oxidised p-phenylenediamine color developers with a color coupler. The color developing solutions employed contain the color developing agent and used developer solutions need to be disposed of safely. Attempts have been made to incorporate p-phenylenediamine color developing agents into silver halide photographic materials but these have had little success largely due to the pronounced staining produced.
The use of sulphonhydrazides as color developers in aqueous color developer solutions which form an azo dye on coupling with a color coupler are described in U.S. Pat. No. 2,424,256, U.S. Pat. No. 4,481,268 and copending British Application No. 9125688.3.
A problem encountered with this system is that it is difficult to obtain the desired hue for the magenta image, for example 1-naphtholic couplers give a violet hue.
European Patent Specification 0 331 185 A describes a class of 3-pyridinol color couplers which form cyan dyes with conventional phenylenediamine color developing agents. There is no suggestion that they will couple with sulphonhydrazide color developers of any sort.
SUMMARY OF THE INVENTION
The present invention provides a process in which a class of couplers are used with sulphonhydrazide color developers to form image dyes of desirable magenta hue.
According to the present invention there is provided a method of forming a photographic color image which comprises imagewise exposing a photographic silver halide color material and processing it with an alkaline processing solution in the presence of a sulphonhydrazide color developing agent and a 3-pyridinol color coupler optionally containing in the 2-position a ballasting group of such size and configuration as to render the coupler non-diffusible in photographic materials thus forming a magenta dye image by reaction of the oxidised color developing agent and the color coupler.
“The present invention also provides a color photographic material comprising at least two color-forming units sensitive to different regions of the spectrum each comprising a silver halide emulsion layer wherein the material contains in at least one said silver halide emulsion layer, a ballasted sulphonhydrazide color developing agent and a 3-pyridinol photographic color coupler capable of forming a magenta dye upon coupling with the oxidized form of said developing agent, both incorporated therein in droplets of a high boiling solvent.”
DETAILED DESCRIPTION OF THE INVENTION
Advantages of the present invention include being able to photographically generate image dyes of desirable magenta hue without the use of p-phenylenediamine developers and allowing both the coupler and the color developer to be incorporated in the photographic material.
The present invention further provides a color photographic material comprising at least two color-forming units sensitive to different regions of the spectrum each comprising a silver halide emulsion layer characterised in that the material contains in or adjacent said layer, a ballasted photographic color coupler and a ballasted sulphonhydrazide color developing agent incorporated therein in droplets of a high boiling solvent and wherein the color coupler is a 3-pyridinol containing in the 2-position a ballasting group of such size and configuration as to render the coupler non-diffusible in photographic materials.
In a preferred embodiment the invention provides a color photographic material in which the material is a multicolor photographic material comprising a support bearing a yellow dye image-forming unit comprised of at least one blue-sensitive silver halide emulsion layer having associated therewith at least one yellow azo dye-forming coupler, at least one magenta dye image-forming unit comprising at least one green-sensitive silver halide emulsion layer having associated therewith at least one magenta dye-forming coupler at least one cyan dye image-forming unit comprising at least one red-sensitive silver halide emulsion layer having associated therewith at least one cyan dye-forming coupler.
The pyridinol color coupler preferably has the formula:
wherein
R is an electron-donating group,
R
1
and R
2
are each hydrogen or a substituent or together complete a carbocyclic or heterocyclic ring which may be substituted, and
wherein at least one of R, R
1
and R
2
contain a ballasting group of such size and configuration as to render the compound non-diffusible in photographic materials.
Examples of groups R are alkyl, alkoxy, alkylthio, hydroxy, —NHCONHR
3
, —NHCOOR
3
, amino, alkyamino or acylamino any of which may contain further substituents, of which specific examples are: methyl, trifluoromethyl, ethyl, t-butyl, octadecyl, benzyl, phenyl, ball-SO
2
NH—, ball-CONH—, ball-NHSO
2
—, ball-NHCO—, R
3
CONH—, R
3
NH—, R
3
SO
2
NH—, R
3
NH— and —COO-alkyl wherein ball is a ballast group and R
3
is an alkyl or aryl group which may be substituted.
Examples of groups that R
1
and R
2
may represent are halogen (eg Cl, Br, F, I), alkyl, aryl, alkylaryl, arylalkyl, heterocyclic, amido, sulphonamido, carbamoyl, sulphamoyl any of which may be substituted.
Examples of rings that R
1
and R
2
may complete are benzene, naphthalene, pyridine or thiophene.
All the substituents referred to above should, as the skilled man will readily recognise, compatible with the function of the compound.
The azo dye is formed as illustrated below:
wherein R
4
—NHNHSO
2
R
5
represents the sulphonhydrazide developing agent.
The sulphonhydrazide color developing agent may have the formula:
R
4
—NHNH—SO
2
—R
5
(2)
wherein
R
4
is an aryl or heterocyclic group which may be substituted, and
R
5
is an alkyl or aryl group, either of which may be substituted, and
wherein
R
4
or R
5
contains a ballasting group of such size and configuration as to render the compound non-diffusible.
A preferred group of developing agents of formula (2) are those in which R
4
is a heterocyclic group. Examples of R
4
are benzoxazole, benzthiazole, benzimidazole and naphthoxazole, naphthothiazole, naphthimidazole, quinoline and quinoxaline radicals, and preferably a 4-quinazolinyl group.
Examples of R
5
include alkyl, aryl, alkylaryl, arylalkyl or heterocyclic any of which may be substituted.
The coupler and the color developer may be incorporated in the photographic silver halide material or the developer. If incorporated in the material, the compound should have a ballasting group of such size and configuration to render it non-diffusible in the photographic material or be in the form of a polymeric coupler.
The ballast group may be attached to couplers of formula (1) by forming part of R, R
1
or R
2
. The ballast group in the sulponhydrazides of formula (2) may be attached by forming part of either R
4
or R
5
.
As is conventional with color couplers, the coupler and the developing agent may be incorporated in the photographic material in droplets of high boiling coupler solvent. The high boiling solvent used to incorporate the coupler and/or color developer in the photographic material may be any solvent known as a coupler solvent (and used for incorporating couplers into photographic materials). Many such solvents are listed in Research Disclosure Item 308119, December 1989 published by Kenneth Mason Publications, Emsworth, Hants, United Kingdom. The coupler and color developer may be incorporated in the same or different droplets of coupler solvent.
The pyridinol couplers used in the present invention may be prepared as described in “Pyridine and its Derivatives”, Supplement Parts 1 and 3 (1974), ed. R A Abramovitch, Wiley Interscience, New York.
Examples of 3-pyridinol couplers of formula (I) are listed in the following table:
TABLE 1
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
(13)
(14)
The fastness of the
Clarke David
Stanley Paul Louis Reginald
Eastman Kodak Company
Kluegel Arthur E.
Letscher Geraldine
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