Radiation imagery chemistry: process – composition – or product th – Radiation sensitive product – Identified radiation sensitive composition with color...
Reexamination Certificate
2000-12-15
2002-07-23
Baxter, Janet (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Radiation sensitive product
Identified radiation sensitive composition with color...
C430S558000
Reexamination Certificate
active
06423484
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a silver halide color photographic light-sensitive material, more specifically to a silver halide color photographic light-sensitive material which excels in a color reproduction and an image fastness and which has an excellent color developability.
BACKGROUND OF THE INVENTION
In general, in a color image forming-process using a silver halide color photographic light-sensitive material, a color image is formed from three color dyes derived from yellow, magenta and cyan couplers.
An aptitude of a color developability in each color is judged by an absorption characteristic, and the absorption characteristic of a color-developed dye can be shown by a spectral absorbing wave form, that is, a characteristic value such as a maximum absorbing wavelength and an absorption coefficient. In addition to these values, a presence of a sub-absorption, a width of an absorption band and a sharpness of an absorption end are important in a problem on a color reproduction of a color photo. For example, a white light is composed of a blue light (400 to 500 nm), a green light (500 to 600 nm) and a red light (600 to 800 nm). Absorption of the green light by a magenta dye provides a red purple color which is the complementary color thereof. In this case, an inferior absorption characteristic of the magenta dye allows a part of the blue light and the red light to be absorbed and causes a hue to be turbid. A vivid color can not be reproduced with the dye having such the inferior absorption characteristic.
A magenta coupler determines a quality of a color development of a green color which is the most sensitive to a human being's eye and therefore, the absorption characteristic thereof is important. In recent years, a pyrazoloazole series coupler having an excellent absorption characteristic has been developed as the magenta coupler in order to improve a color reproduction. Of them, a 1H-pyrazolo[3,2-c][1,2,4]triazole series magenta coupler and a 1H-pyrazolo[1,5-b][1,2,4]triazole series magenta coupler are excellent in terms of not only an absorption characteristic of a dye but also a color developability as compared with the other couplers. The pyrazolotriazole type coupler does not show a sub-absorption in a blue light region as compared with a pyrazolone type coupler and the absorption end thereof at a longer wavelength side is sharply cut, and an excessive absorption in a red light region is very small as well.
An optimum absorption wavelength of a magenta dye is varied according to a cyan coupler and a yellow coupler which are used in combination therewith, and therefore in a dye derived from the magenta coupler having such the absorption characteristic as described above, absence of an absorbing wavelength in a suitable position causes an another problem. That is, an absorption in a too short wavelength region generates a region in which a light is not sufficiently absorbed at an interval to an absorption region of a cyan dye and leads to incapability to reproduce a vivid purple color and black color. On the contrary, an absorption in a too long wavelength region generates a region in which a light is not sufficiently absorbed an interval to an absorption region of a yellow dye and leads to incapability to reproduce a vivid red color and black color. Accordingly, a technique for controlling a hue is important in the pyrazoloazole series coupler more than in the pyrazolone type coupler.
Further, an optimum absorption wavelength of the magenta dye is varied as well according to a use purpose of a light-sensitive material. In the case where the light-sensitive material is used, for example, as a block copy, a design is required to be made so that the optimum absorption wavelength is shifted to a shorter wavelength than in case of a conventional color print to meet a hue of a printing ink. That requires a technique for freely controlling the hue.
With respect to the technique for controlling the hue, the hue can be controlled with a substituent. For example, in the couplers having the same primary structure, an absorption wavelength of a dye formed can be changed according to the kind of the substituent. A degree of controlling the hue is varied according to a position into which the substituent is introduced. In general, introduction of an electron attractive group causes a long wavelength shift and the introduction of an electron donative group causes a short wavelength shift.
However, such a change in the substituent is accompanied with a change in a performance which is important for a coupler, such as, for example, a coupling activity and a fastness to heat and light. These performances are not necessarily changed to a preferable direction at the same time as controlling the hue. As a matter of fact, this requires to select and use a coupler which has a lot of the averagely excellent performances and provides a working load for selecting the coupler.
Even if the same coupler would be used, the absorption wavelength of the dye can be controlled to some extent according to the use method thereof, for example, a kind and an amount of a high boiling organic solvent used for emulsion-dispersion and use of the other additives. The most important is a polarity of the high boiling organic solvent represented by a dielectric constant, a hydrogen bonding property and an electron donating property. Of them, the dielectric constant is used as a parameter for the polarity in many cases. The high boiling organic solvent having the high dielectric constant allows an absorption wavelength to be shifted to a shorter wavelength. A molecular structure of the high boiling organic solvent for raising the dielectric constant is a polar group containing a hetero atom and a structure containing a lot of an aromatic ring, and the high boiling organic solvent which is used well includes, for example, tricresyl phosphate and dibutyl phthalte. Meanwhile, the molecular structure of the high boiling organic solvent for lowering the dielectric constant is a structure containing a lot of a part of a hydrophobic aliphatic chain and includes, for example, trioctyl phosphate and fatty acid alkyl esters. A hue control by such the high boiling organic solvent affects a color developability of a coupler and a fastness of a dye in some cases but succeeds to some extent.
It is known that an addition of a compound having a phenolic hydroxyl group and a sulfonamide group can allow an absorption by a dye to be shifted to a longer wavelength.
However, an additive which allows an absorption wavelength to be shifted to a shorter wavelength is not known.
A relationship of a dielectric constant of the high boiling organic solvent with a hue is described in N. S. Bayliss and E. G. McRae, J. Phys. Chem. 58, 1002, 1006 (1954).
Meanwhile, there are described in European Patents EP0276319 and EP0382443, the processes in which the polymers derived from acrylic acid ester, acrylamide and styrene are added to an oil drop together with a coupler for a purpose of improving a fastness of a dye to light and heat. In this case, the polymers generally have a molecular weight of not much more than 10,000 to 200,000. In the case where the polymer has the molecular weight of 20,000 or more, it is excellent in terms of an anti-discoloring effect but includes a problem that it lowers a color developability of the coupler.
The present inventors investigated to use the high boiling organic solvent with which a success has been gained to some extent for a purpose of controlling a hue of the magenta coupler of the present invention based on a conventional knowledge. That resulted in obtaining an almost satisfactory result regarding a shift to a longer wavelength but it was clarified that a serious problem was still remained regarding a shift to a shorter wavelength. That is, in the case where the high boiling organic solvent having a low dielectric constant is used in order to shift a hue of a coupler to a shorter wavelength, a turbidity is generated in a coated fil
Kawagishi Toshio
Mizukawa Yuki
Sato Kozo
Sato Takehiko
Takahashi Osamu
Baxter Janet
Walke Amanda C
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