Radiation imagery chemistry: process – composition – or product th – Radiation sensitive product – Two or more radiation-sensitive layers containing other than...
Reexamination Certificate
2000-08-07
2002-07-30
Letscher, Geraldine (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Radiation sensitive product
Two or more radiation-sensitive layers containing other than...
C430S549000, C430S557000, C430S558000, C430S552000, C430S553000, C430S383000, C430S385000, C430S387000, C430S389000
Reexamination Certificate
active
06426178
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to photographic silver halide print media and, in particular, to coupler co-dispersions for chromogenic black and white print media developed in standard rapid color process chemistry.
BACKGROUND OF THE INVENTION
Chromogenic black and white print media are formulated with one or more light sensitive silver halide layers, typically on reflective support. Each light sensitive layer develops to a neutral dye hue when processed in standard RA color development chemistry. This is accomplished by co-dispersing cyan, magenta, and yellow dye-forming couplers in such a manner that the mixture of dyes formed during development combine to give the desired neutral. Other hues of commercial interest may be achieved by changing the relative proportions of the couplers in the co-dispersion.
Current commercial chromogenic print media employ magenta couplers derived from pyrazolones of general formula MAGENTA-I, in particular, four equivalent analogues in which X=H. Chromogenic print media formulated with couplers of general formula MAGENTA-I are unstable to heat or light, causing areas of minimum density, Dmin, to darken with time by formation of a red-yellow stain.
wherein R
c
is a substituent (preferably an aryl group); R
d
is a substituent (preferably an anilino, carbonamido, ureido, carbamoyl, alkoxy, aryloxycarbonyl, alkoxycarbonyl, or N-heterocyclic group); X is hydrogen or a coupling-off group.
Although the prior art discloses other magenta dye-forming couplers possessing improved thermal stability for chromogenic black and white media, these have not been commercially useful because of their low relative reactivities when co-dispersed with typical cyan and yellow dye-forming couplers. Thus, U.S. Pat. No. 5,362,616 of J. L. Edwards, P. T. Hahm, M. J. Bogdanowicz, J. L. LaBarca describe the combination of ortho-aryloxy aniline derived yellow couplers in combination with pyrazolotriazoles for chromogenic black and white media. European Application 0 600 377 A1 of J. L. Edwards describes the use of yellow couplers derived from ortho-methoxy anilines. U.S. Pat. No. 5,728,511 of T. Hirosawa, K. Katsube, J Komiyama, Y. Hayafuchi, and T. Nakamura discloses the use of pyrazolotriazole magenta couplers in combination with yellow couplers derived from ortho-chloro anilines. U.S. Pat. No. 5,939,247 of T. Hirosawa, K. Katsube, T. Nakamura, Y. Hayafuchi, K. Arasawa, J Komiyama, and T. Fujita also discloses pyrazolotriazoles in combination with yellow couplers derived from ortho-chloro anilines. U.S. Pat. No. 5,491,053 of G. N. Barber, P. R. Greco, M. J. Bogdanowicz, and E. L. Kelly teaches the combinations of pyrazolones with ortho chloro anilines for chromogenic black and white media.
In particular, magenta dye-forming couplers derived from pyrazoletriazoles of general formula MAGENTA-2,
wherein R
a
and R
b
independently represents H or a substituent; X is hydrogen or a coupling-off group; and Z
a
, Z
b
, and Z
c
are independently a substituted methine group, ═N—, ═C—, or —NH—, provided that one of either the Z
a
—Z
b
bond or the Z
b
—Z
c
bond is a double bond and the other is a single bond, and when the Z
b
—Z
c
bond is a carbon-carbon double bond, it may form part of an aromatic ring, and at least one of Z
a
, Z
b
, and Z
c
represents a methine group connected to the group R
b
.
The Magenta-2 couplers are disadvantaged in present hromogenic lack and white print media because the dye curves they produce are poorly matched in either speed, contrast, or Dmax relative to the dye curves formed by common yellow and cyan dye-forming couplers previously disclosed in the trade. When the differences in speed, contrast, and Dmax are large enough, non-neutral color shifts may be observed. Balancing coupler proportions to produce neutral highlights in prints causes non-neutral color bias in the shadow details. Similarly, balancing coupler proportions to achieve neutrality in the shadow details may cause a color bias in the highlights. The color bias increases as the differences in speed, Dmax, and contrast increase between the dye curves. It is, therefore, desirable for the speed, contrast, and Dmax of the dye curves to match as closely as possible.
Another problem in current chromogenic black and white media relates to the generally poorer light stability of magenta dyes formed from couplers of general formula MAGENTA-1.
PROBLEM TO BE SOLVED BY THE INVENTION
There is a need for more stable chromogenic black and white images.
SUMMARY OF THE INVENTION
It is an object of the invention to provide improved thermal stability in chromogenic black and white print media.
It is another object to provide improved image stability of chromogenic black and white print media to light.
It is another object to provide improved co-dispersions of cyan, magenta, and yellow dye-forming couplers for chromogenic black and white print media.
It is another object of the invention to provide a chromogenic black and white print media that reproduces color lightness L* as previously disclosed in U.S. Pat. No. 5,362,616; that is, colors are printed as neutrals with similar lightness.
These and other objects of the invention are accomplished by the photographic element for forming neutral images comprising a cyan dye-forming coupler, a magenta dye-forming coupler of formula MAGENTA-2,
wherein R
a
and R
b
independently represents H or a substituent; X is hydrogen or a coupling-off group; and Z
a
, Z
b
, and Z
c
are independently a substituted methine group, ═N—, ═C—, or —NH—, provided that one of either the Z
a
—Z
b
bond or the Z
b
—Z
c
bond is a double bond and the other is a single bond, and when the Z
b
—Z
c
bond is a carbon-carbon double bond, it may form part of an aromatic ring, and at least one of Z
a
, Z
b
, and Z
c
represents a methine group connected to the group R
b
.
and yellow dye-forming coupler of formula YELLOW-II,
wherein:
R
5
-R
10
, are substituents. R
5
is either an alkoxy group with more than one carbon atom, aryloxy group, anilino group, arylthio group, alkylthio group, or dialkylamino group. R
5
groups are linked to the anilide phenyl ring by oxygen, sulfur or nitrogen.
R
6
is bonded to the -3 through -6 position relative to the anilino nitrogen and is independently selected from a group consisting of hydrogen, halogen, alkoxycarbonyl(—CO
2
R), carbamoyl(—CONRR′), carbonamido(—NRCOR′), sulfonate(—OSO
2
R), sulfamoyl(—SO
2
NRR′), sulfonamido(—NRSO
2
R′), or sulfonyl (—SO
2
R). R and R′ may be hydrogen or substituted or unsubstituted alkyl or aryl groups. Suitable examples of R and R′ groups are ethyl, hexadecyl, 2-ethylhexyl, p-dodecylphenyl;
q is 1 to 4;
R
7
is either alkyl, cyclic, or multicyclic alkyl, aryl, heterocyclic, heteroaromatic, and amine groups. Suitable examples of R
7
include tertiary butyl and 1-adamantyl;
R
8
, R
9
, and R
10
are each independently selected from the group hydrogen, alkyl, aryl, or alkoxy groups. Suitable examples of R
8
, R
9
, and R
10
include methyl, ethyl, benzyl, and ethoxy.
ADVANTAGEOUS EFFECT OF THE INVENTION
The invention provides a chromogenic black and white reflective photographic paper material that, when developed in standard RA color development chemistry, produces images having improved thermal and light stability.
DETAILED DESCRIPTION OF THE INVENTION
The invention has numerous advantages over prior chromogenic black and white media. The invention photographic element forms an excellent neutral image over a wide range of exposure times for conventional and digital exposure devices. The image formed by the invention media exhibits much improved thermal and light stability, maintaining white Dmins after extended incubation to heat or light. The invention media also preserves color lightness reproduction previously described in U.S. Pat. No. 5,362,616 which enhances perceived image quality. The preferred structure of the invention media has a single imaging layer that provides for improved sharpness and developability. yellow dye-formin
Coms Frank D.
Roberts Michael R.
Schroeder Kurt M.
Blank Lynne M.
Eastman Kodak Company
Leipold Paul A.
Letscher Geraldine
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