Radiation imagery chemistry: process – composition – or product th – Radiation sensitive product – Identified radiation sensitive composition with color...
Reexamination Certificate
2000-06-13
2002-08-27
Baxter, Janet (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Radiation sensitive product
Identified radiation sensitive composition with color...
C430S531000, C430S533000, C430S607000, C430S614000
Reexamination Certificate
active
06440655
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to the use of certain amido compounds as stabilizers/antifoggants in silver halide photographic elements coated on polyester supports.
BACKGROUND OF THE INVENTION
It is well known to coat silver halide photographic materials on cellulose acetate (acetate) supports. In certain instances, it has been found advantageous to coat these materials on polyester supports when increased dimensional stability or mechanical strength of the photographic element is desired, as described in U.S. Pat. No. 3,649,336. Polyethylene terephthalate (“PET”) and polyethylene naphthalate (“PEN”) supports both have improved mechanical strength and curl relaxation characteristics when compared with acetate and other supports.
It is also known that there are advantages in employing small negative sizes in amateur photography, as described in Research Disclosure 36230, June 1994, pp316-329. It is envisioned that amateur photographers will want to have the option of a large number of exposures in a roll (or cassette) of film, without the cassette becoming unduly large and bulky. While 36 exposures is now commonly available, there is a need for 40 or more exposures in a single roll. In order to accommodate this large number of exposures, the total film thickness must be such that the total length of film will fit inside of the film cassette without jamming or binding. This is especially important during periods of high humidity, where the gelatin can swell and cause the film to stick or jam. Thinner supports may be used to reduce total film thickness, but problems arise when the support becomes too thin, such as lack of dimensional stiffness and a high tendency to curl.
It is also desired that the film is protected from fogging due to an electrostatic discharge. In the past this was accomplished through the incorporation of ultraviolet light absorbing (UV) dyes dispersed in coupler solvent in layers above and below the light sensitive imaging layers. In this way, the film is protected against spark generated UV radiation coming in from the front or the back. The dye and the coupler solvent in which the dye is dispersed, however, contribute to the overall thickness of the film. Gelatin may be reduced to decrease thickness, but when the gelatin laydown becomes too low, the coupler solvent coated in the layers below the non-imaging layers may weaken the adhesive bond between those layers and the support.
It is possible to obtain very thin films utilizing PEN and PET supports when compared to cellulose triacetate. It has also been recognized that a feature of PEN base is it's ability to absorb ultaviolet light at 380 nm, as discussed in Hatsumei Kyoukai Koukai Gihou No. 94-6023 Section 12, published by the Japanese Patent Office.
Unfortunately, a change in film sensitometric stability is quite often observed when applying a silver halide photographic emulsion on either PEN or PET. Specifically, high temperature fog growth is more frequently encountered or observed to a larger magnitude when film formula are produced on PEN or PET than when the exact same formula is produced on acetate.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, spectra/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. Nos. 4,255,510 and 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. Nos. 4,442,290 and 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 or developed under high temperature conditions. This need is particularly great for films utilizing PEN or PET as a support.
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 a polyester support and 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;
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 I does not substantially react with oxidized developer to release INH.
The photographic el
Burgmaier George J.
Reynolds James H.
Szatynski Steven P.
Younathan Janet N.
Baxter Janet
Eastman Kodak Company
Meeks Roberts Sarah
Walke Amanda C.
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