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...
C430S546000, C430S448000, C430S607000, C430S613000
Reexamination Certificate
active
06472135
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to silver halide photographic materials having both improved raw-stock/latent image keeping properties and reduced fogging. This invention specifically relates to photographic materials comprising hexose reductones and amido compounds.
BACKGROUND OF THE INVENTION
Reductones have been used in the photographic industry to improve raw stock keeping and latent image keeping. Piperidino hexose reductone (PHR) (2-,5-Dihydroxy-5-methyl-3-{1-piperidinyl}-2-cyclo-penten-1-one), R-1) is known in the art as an addendum for photographic materials, as described for example in
Research Disclosure
, Item 37038 of February 1995. Reducing agents in general have been previously disclosed as addenda for silver chloride emulsion applications (EP 335,107). PHR has also been disclosed in combination with spectral sensitizing dyes (U.S. Pat. No. 3,695,888), and reductones are also discussed in U.S. Pat. No. 2,936,308 and U.S. Pat. No. 3,667,958. Water soluble amino hexose reductones have been disclosed in U.S. Pat. No. 5,763,146 and hexose reductone in combination with green sensitized epitaxially finished tabular grain emulsions has been disclosed in U.S. Pat. No. 5,773,208. Unfortunately the use of hexose reductones has been accompanied by an increase in fog growth under high temperature conditions.
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 preparation 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.
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. Such a need particularly exists for photographic elements containing hexose reductone.
SUMMARY OF THE INVENTION
This invention provides a silver halide photographic element comprising at least one silver halide emulsion, said silver halide element further comprising an amido compound represented by Formula 1
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
3a
being defined the same as R
1
or R
2
; and wherein the compound of Formula 1 does not substantially react with oxidized developer to release INH; and a reductone compound represented by Formula 2.
wherein R
7
and R
8
are the same or different, and may represent H, alkyl, cycloalkyl, aryl, or an alkyl group with a solubilizing group such as —OH, sulfonamide, sulfamoyl, or carbamoyl, R
7
and R
8
may be joined to complete a heterocyclic ring, R
4
and R
5
are H, OH, alkyl, aryl, cycloalkyl, or may together represent an alkylidene group, n is 1 or 2 and R
3
is H, alkyl, aryl, or CO
2
R
6
where R
6
is alkyl.
The photographic elements of this invention demonstrate improved raw stock and latent image keeping and they demonstrate reduced fogging under high temperature conditions. They also provide the antifoggant effect when the photographic element is developed under high temperature conditions. The amido compounds contained in such elements provide the antifoggant effect only when needed, e.g. at high storage temperatures, thus reducing the possibility of undesirable sensitometric effects. The preferred 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 1.
The compounds of Formula 1 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 substantially released. A suitable test involves placing an amido compound in the following developer solu
Burgmaier George J.
Kellogg Lillian M.
Reynolds James H.
Szatynski Steven P.
Baxter Janet
Eastman Kodak Company
Meeks Roberts Sarah
Walke Amanda C.
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