Silver halide photographic light-sensitive material

Details Silver halide photographic light-sensitive material Silver halide photographic light-sensitive material

2001-03-07

2002-10-22

Letscher, Geraldine (Department: 1752)

Radiation imagery chemistry: process, composition, or product th

Radiation sensitive product

Identified radiation sensitive composition with color...

C430S543000

Reexamination Certificate

active

06468729

ABSTRACT:

CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2000-062749, filed Mar. 7, 2000, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to a novel color coupler compound and, more particularly, to a silver halide color photographic light-sensitive material using the compound and an image formation method using the material. More specifically, the present invention relates to a silver halide color reversal photographic light-sensitive material and an image formation method using the material.
Recently, silver halide color photographic light-sensitive materials are strongly required to have faithful color reproducibility in addition to high sensitivity, high sharpness, and high graininess.
In the field of silver halide color photographic light-sensitive materials, a 1-phenyl-5-pyrazolone coupler has been conventionally widely used as a magenta coupler. On the other hand, compounds having little side absorption and good hue which are preferred as image forming dyes are being sought recently, and some pyrazoloazole-based couplers having little side absorption near 430 nm have been put into practical use.
Pyrazolotriazole magenta couplers are excellent compounds in that they have good hue. However, when introduced into light-sensitive materials, they pose various problems such as a low color generation efficiency, low resistance against processing variations, and low color image storage stability.
For example, a 4-equivalent coupler which couples with the oxidized form of an aromatic primary amine developing agent in the position of hydrogen atom substitution has a low color generation efficiency, although it has high graininess, and hence causes yellow stains by aging after development. On the other hand, a 2-equivalent coupler whose coupling position is substituted by a split-off group (e.g., a halogen atom) except for a hydrogen atom generates a color with a smaller silver amount than a 4-equivalent coupler. Although this 2-equivalent coupler does not easily cause yellow stains, it unfortunately lowers the graininess and degrades the image quality.
Many such photographic couplers are used as they are dispersed in high-boiling organic solvents such as phosphoric ester and phthalic ester. However, with the recent demand for high sharpness, a reduction of the use amount of these high-boiling organic solvents, i.e., so-called oilless processing is being sought. Unfortunately, many conventional couplers including pyrazolotriazole magenta couplers significantly lower the color generation efficiency when used in oilless processing.
To solve these problems, couplers in which substituents on pyrazoloazole rings are variously improved have been proposed. For example, U.S. Pat. No. 4,882,266 and European Patent Publication No. 183,445 have disclosed improvements of the light fastness of a color image by couplers in which the bulkiness of a 6-position substituent is increased. Jpn. Pat. Appln. KOKAI Publication No. (hereinafter referred to as JP-A-)1-102557 has disclosed improvements of the color generation efficiency in oilless processing by couplers in which carboxylic acid is introduced as a dissociation group into coupler molecules. Unfortunately, when the present inventors attempted to apply these techniques, improvements of yellow stains and color image storage stability by these techniques during aging after processing were still unsatisfactory. Although the color generation efficiency was increased by the introduction of a dissociation group, the couplers increased the cost and deteriorated the crystallinity and hence cannot be used in industrial applications. Also, yellow stains were formed when non-color-forming portions were irradiated with light or in a high-humidity, high-temperature ambient. Furthermore, the sensitivity decreased when the couplers were retained before coating after they were mixed in color-sensitized silver halide emulsions.
Most pyrazoloazole-based couplers currently put into practical use are 2-equivalent couplers having a split-off group except for a hydrogen atom in a portion where these couplers react with the oxidized form of a color developing agent. Color reversal photographic light-sensitive materials are subjected to first development, reversal processing, and color development in this order. 2-equivalent couplers have an essential problem that since they have a high color generation efficiency per mol of silver, they decrease the sensitivity during the course of development compared to 4-equivalent couplers. Therefore, when pyrazoloazole magenta couplers are to be applied to color reversal photographic light-sensitive materials, 4-equivalent couplers are preferred in respect of sensitivity. Applications of 4-equivalent pyrazoloazole magenta couplers to color reversal photographic light-sensitive materials are described in, e.g., JP-A's-5-100382 and 63-153548. However, these techniques have not solved the above-mentioned problem of yellow stains caused by aging after processing.
BRIEF SUMMARY OF THE INVENTION
It is the first object of the present invention to provide a silver halide color photographic light-sensitive material which has high color reproducibility, high fastness, and high image stability, and produces stains little. It is the second object of the present invention to provide a coupler which achieves a high color generation efficiency even when the use amount of a high-boiling organic solvent is reduced, i.e., even in oilless processing. It is the third object of the present invention to provide a novel pyrazolotriazole-based compound which can be produced at low cost and has high producing suitability.
The present inventors made extensive studies to seek a coupler which has high image storage stability, improves sensitivity decrease occurring when mixed with a silver halide emulsion, and has a high color generation efficiency even in oilless processing, and have completed the present invention.
That is, the objects of the present invention are achieved by the following arrangements.
(1) A silver halide color photographic light-sensitive material comprising at least one silver halide emulsion layer on a support, the at least one emulsion layer containing a magenta coupler represented by formula (M-1):
where R
1
represents a substituted or unsubstituted alkyl group, each of L
1
and L
2
independently represents a substituted or unsubstituted alkylene group, or a substituted or unsubstituted arylene group, and A represents a substituted or unsubstituted aryl group, or a substituted or unsubstituted alkyl group, with the proviso that A is neither a
2-octyloxy-5-tert-octylphenyl group nor a
2-(4-methylphenoxy)ethoxy-5-tert-octylphenyl group.
(2) The silver halide color photographic light-sensitive material according to item (1), wherein the magenta coupler is represented by formula (M-2):
where R
1
, L
1
, and L
2
have the same meanings as in formula (M-1) of item (1), R
2
represents a halogen atom, nitro group, cyano group, —COR
3
, —COOR
3
, —CON(R
4
)R
3
, —N(R
4
)COOR
3
, —N(R
4
)CO N(R
5
)R
3
, —CON(R
4
)SO
2
R
3
, or —N(R
4
)COR-
3
, p is an integer from 1 to 5, wherein a plurality of R
2
's may be the same or different if p is not less than 2, and each of R
3
, R
4
, and R
5
independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, R
3
and R
4
may be combined to form a ring, and the value of pKa at 25° C. of —NHSO
2
— which bonds to L
2
and the phenyl group in a magenta coupler represented by formula (M-2) is not more than 12 in a solution of THF/H
2
O={fraction (6/4)}.
(3) The silver halide color photographic light-sensitive material according to item (2), wherein the magenta coupler is represented by formula (M-5):
where R
2
and p have the same meanings as in formula (M-2) of item (2), R
1
represents a secondary or tertiary unsubstituted alkyl group having

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