Radiation imagery chemistry: process – composition – or product th – Radiation sensitive product – Identified radiation sensitive composition with color...
Reexamination Certificate
2000-06-13
2002-10-29
Baxter, Janet (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Radiation sensitive product
Identified radiation sensitive composition with color...
C430S607000, C430S614000
Reexamination Certificate
active
06472133
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to the use of certain amido compounds as stabilizers/antifoggants in silver halide photographic elements.
BACKGROUND OF THE INVENTION
Problems with fogging have plagued the photographic industry from its inception. Fog is a deposit of silver or dye that is not directly related to the image-forming exposure, i.e., when a developer acts upon an emulsion layer, some reduced silver is formed in areas that have not been exposed to light. Fog can be defined as a developed density that is not associated with the action of the image-forming exposure, and is usually expressed as “D-min”, the density obtained in the unexposed portions of the emulsion. Density, as normally measured, includes both that produced by fog and that produced as a function of exposure to light. It is known in the art that the appearance of photographic fog related to intentional or unintentional reduction of silver ion (reduction sensitization) can occur during many stages of reparation of the photographic element including silver halide emulsion preparation, spectral/chemical sensitization of the silver halide emulsion, melting and holding of the liquid silver halide emulsion melts, subsequent coating of silver halide emulsions, and prolonged natural and artificial aging of coated silver halide emulsions. The chemicals used for preventing fog growth as a result of aging or storage are generally known as emulsion stabilizers.
The control of fog, whether occurring during the formation of the light-sensitive silver halide emulsion, during the spectral/chemical sensitization of those emulsions, during the preparation of silver halide compositions prior to coating on an appropriate support, or during the aging of such coated silver halide compositions, has been attempted by a variety of means. Mercury-containing compounds, such as those described in U.S. Pat. Nos. 2,728,663; 2,728,664; and 2,728,665, have been used as additives to control fog. Thiosulfonates and thiosulfonate esters, such as those described in U.S. Pat. Nos. 2,440,206; 2,934,198; 3,047,393; and 4,960,689, have also been employed. Organic dichalcogenides, for example, the disulfide compounds described in U.S. Pat. Nos. 1,962,133; 2,465,149; 2,756,145; 2,935,404; 3,184,313; 3,318,701; 3,409,437; 3,447,925; 4,243,748; 4,463,082; and 4,788,132 have been used not only to prevent formation of fog but also as desensitizers and as agents in processing baths and as additives in diffusion transfer systems Recently, a class of compounds has been reported to have benefits in stabilizing silver halide emulsions against such changes due to storage at high temperature and humidity. This class of sulfur heterocycle are compounds in which one of the two sulfur atoms in a five-membered heterocyclic ring is oxidized either to the tetravalent state (dithiolone dioxide) or to the trivalent state (dithiolone oxide). U.S. Pat. No. 5,693,460 teaches the stabilizing properties of dithiol-3-one 1,1-dioxides. U.S. Pat. No. 5,670,307 describes the combination of dithiol-3-one 1,1-dioxides with sulfinates. U.S. Pat. No. 5,756,278 relates to the combination of water soluble gold sensitizers with dithiolone dioxide compounds for enhanced emulsion sensitivity. U.S. Pat. No. 5,677,119 describes the stabilizing properties of dithiol-3-one 1-oxide in silver halide light sensitive materials.
U.S. Pat. No. 4,255,510 and U.S. Pat. No. 4,256,881 describe blocked benzotriazoles as development restrainers for color diffusion transfer photographic elements. UK Patent GB 2,062,884(A) discloses a photographic dye image-receiving sheet containing a blocked 5-mercaptotetrazole development restrainer. Blocked mercaptotetrazoles are also described in U.S. Pat. No. 4,442,290 and U.S. Pat. No. 4,888,268. In addition, various blocked antifoggants and development restrainers have been disclosed in Japanese Patent No. 586,882 and U.S. Pat. Nos. 3,364,028, 3,575,699 and 3,649,267.
However, despite all the efforts in this field there still remains a need for compounds which act as effective antifoggants in photographic elements which are stored under high temperature conditions.
SUMMARY OF THE INVENTION
This invention provides a silver halide photographic element comprising at least one silver halide emulsion layer containing a dye-forming coupler which reacts with an oxidized color developing agent to form dye, said silver halide element further comprising an amido compound of Formula I
wherein INH is a development inhibitor;
LINK is a linking or timing group and m is 0, 1 or 2; and
R
1
and R
2
independently represent an aliphatic, aromatic or heterocyclic group, or R
1
and R
2
together with the nitrogen to which they are attached represent the atoms necessary to form a 5 or 6 membered ring or multiple ring system, or R
1
and R
2
are independently a —C(═O)(LINK)
m
—INH group, or are substituted with an —NR
3a
C(═O)—LINK)
m
—INH group, with R
3
a being defined the same as R
1
or R
2
, and wherein the compound of Formula I does not substantially react with oxidized developer to release INH.
The photographic elements of this invention demonstrate reduced fogging under high temperature conditions. In addition, the amido compounds contained in such elements provide the antifoggant effect only when needed, i.e. at high storage temperatures, thus reducing the possibility of undesirable sensitometric effects. The amido compounds also do not season out of the photographic elements during processing, thereby reducing seasoning of the photographic processing solutions. Unintentional seasoning of such solutions with antifogging or stabilizing compounds can also cause undesirable sensitometric effects.
DETAILED DESCRIPTION OF THE INVENTION
The amido compounds of this invention are blocked antifoggants represented by the following Formula I.
The compounds of Formula I are not couplers and do not substantially react with oxidized color developing agent to form dye and release INH during normal processing conditions. That is, when silver halide photographic elements containing the amido compounds are processed in developer as described below, the INH moiety is not released. A suitable test involves placing an amido compound in the following developer solution; para-phenylenediamine (4.5 g/l), potassium carbonate (34.4 g/l), potassium bicarbonate (2.3 g/l) at pH 10 to which has also been added 1 g/l of potassium ferricyanide to oxidize the developer to Dox. Under these conditions at 40 deg C, inhibitor-releasing couplers that are well known in the art will react substantially in three minutes to form dye and release their inhibitors. However, the materials useful in this invention will undergo less than a 5% reaction under similar conditions.
INH is a development inhibitor moiety. Examples of INH include but are not limited to compounds having a mercapto group bonded to a heterocyclic ring, such as substituted or unsubstituted mercaptoazoles (specifically 1-phenyl-5-mercaptotetrazole, 1-(4-carboxyphenyl)-5-mercaptotetrazole, 1-(3-hydroxyphenyl-5-mercaptotetrazole), 1-(4-sulfophenyl)-5-mercaptotetrazole, 1-(4-sulfamoylphenyl)-5-mercaptotetrazole, 1-(3-hexanoylaminophenyl)-5-mercaptotetrazole, 1-ethyl-5-mercaptotetrazole, 1-(2-carboxyethyl)-5-mercaptotetrazole, 2-methylthio-5-mercapto-1,3,4-thiadiazole, 2-(2-carboxyethylthio)-5-mercapto-1,3,4-thiadiazole, 3-methyl-4-phenyl-5-mercapto-1,3,4-thiadiazole, 2-(2-dimethyaminoethylthio)-5-mercapto-1,3,4-thiadiazole, 1-(4-n-hexylcarbamoylphenyl)-2-mercaptoimidazole, 3-acetylamino-4-methyl-5-mercapto-1,2,4-triazole, 2-mercaptobenzoxazole, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 2-mercapto-6-nitro-1,3-benzoxazole, 1-(1-naphthyl)-5-mercaptotetrazole, 2-phenyl-5-mercapto-1,3,4-oxadiazole, 1-(3-(3-methylureido)phenyl)-5-mercaptotetrazole, 1-(4-nitrophenyl)-5-mercaptotetrazole, and 1-butyl-5-mercaptotetrazole), substituted or unsubstituted mercaptoazaindenes (specifically 6-methyl-4-mercapto-1,3,3a,7-tetraazaindene, 6-methyl-2-benzyl-4-mercapto-1,3,3a,7-tetraazaindene, 6-phenyl-4-mercaptotetraazaindene, and 4,
Burgmaier George J.
Kellogg Lillian M.
Reynolds James H.
Singer Stephen P.
Szatynski Steven P.
Baxter Janet
Eastman Kodak Company
Meeks Roberts Sarah
Walke Amanda C.
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