Radiation imagery chemistry: process – composition – or product th – Radiation sensitive product – Two or more radiation-sensitive layers containing other than...
Reexamination Certificate
2002-01-18
2003-05-06
Letscher, Geraldine (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Radiation sensitive product
Two or more radiation-sensitive layers containing other than...
C430S554000, C430S555000, C430S558000, C430S552000, C430S553000, C430S631000, C430S567000
Reexamination Certificate
active
06558886
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a direct view silver halide photographic element containing a particular green record that contains a coupler or couplers that provide an improved flesh tone reproduction.
BACKGROUND OF THE INVENTION
In a silver halide photographic element, a color image is formed when the element is exposed to light and then subjected to color development with a primary aromatic amine developer. Color development results in imagewise reduction of silver halide and production of oxidized developer. Oxidized developer then reacts with one or more incorporated dye-forming couplers to form an imagewise distribution of dye.
In any polychromatic chromogenic photographic element designed for direct view, it is desirable to accurately reproduce the hue of flesh tones of different densities. Direct view elements are more fully defined hereinafter to include reproductions intended for human viewing such as prints, projection images and transparencies such as back-lit signs. These photographic elements are distinguished from the so-called image capture elements that are used only as an intermediate to produce direct view elements via optical or digital printing methods.
It is also desirable to accurately reproduce neutral backgrounds in scenes when the photographic material is balanced to a pleasing flesh tone. This is especially true for wedding portraits and similar images where the blacks and whites must be accurately reproduced.
Finally, besides providing images with desirable flesh hue and neutrals, it is also desirable to provide images with satisfactory image stability. Images that fade quickly upon exposure to light and/or the environment are undesirable. It is a therefore a desire to provide the foregoing flesh and neutral benefits without sacrificing image stability.
It has been suggested to employ pyrazolotriazole magenta dye-forming couplers in the green record of direct view elements. It has also been suggested to employ certain so-called 2,5-diacylamino cyan couplers in the red record of direct view elements. See for example U.S. Pat. Nos. 5,925,503, 5,972,574, and 5,962,198.
It is a problem to be solved to provide a direct view multicolor element that provides improved flesh tone reproduction.
SUMMARY OF THE INVENTION
The invention provides a silver halide direct view multicolor photographic element comprising a green record containing a green light sensitized silver halide emulsion and comprising either (a) a magenta dye-forming coupler and a cyan dye-forming coupler in an amount of at least 0.1 mole % of the couplers present in the green record, or (b) a green record having a coupler or couplers sufficient to provide upon development a Status A red density greater than 0.23 as measured using a green light separation exposure at a Status A green density of 1.0.
Embodiments of the invention provide direct view elements that have an improved flesh tone reproduction.
DETAILED DESCRIPTION OF THE INVENTION
The invention is generally as described above. The multicolor elements of the invention comprise a blue record sensitized for maximum sensitivity in the range of 400-500 nm, a green record sensitized for maximum sensitivity in the range of 500-600 nm, and a red record sensitized for maximum sensitivity in the range of 600-700 nm. The present invention provides for the selection of the dye forming couplers in the green record to enable an improved flesh tone reproduction.
In the invention, the green record contains one or more couplers capable of forming a dye upon development so that the element exhibits a Status A red density greater than 0.23 at a green density of 1.0, as measured using a green light separation exposure. In one embodiment, the green record contains a light sensitive magenta dye-forming coupler and a cyan dye-forming coupler in an amount of at least 0.1 mole %, suitably at least 0.3 mole % or at least 0.5 mole % of the couplers of the couplers present in the record.
The cyan dye-forming coupler to be included in the magenta record is a phenolic, naphtholic or pyrroloazole coupler. A useful phenolic coupler is a 2-acylamino-5-alkyl phenol, a 2,5-diacylamino phenol, or a 2-ureido-5-acylamino phenol. In one embodiment, the useful cyan coupler is a so-called NB coupler as more fully defined hereinafter.
The magenta dye-forming coupler in the magenta record is suitably an azole coupler. One type of suitable coupler is a pyrazolotrazole coupler, particularly one with a tetramethylethyl link. Examples include a 1H-pyrazolo (5,1-c)[1,2,4]triazole or a 1H-pyrazolo(1,5-b)[1,2,4]triazole compound.
In another embodiment of the invention, the green record contains a magenta dye-forming coupler such that the element exhibits a Status A red density greater than 0.23 at a green density of 1.0, as measured using a green light separation exposure. Desirably, the red density is greater than 0.24 or 0.25 and is less than 0.40. The green record of such an element may also contain the cyan coupler as above described.
A direct view multicolor photographic element of the invention comprises a green record containing a light sensitive magenta dye-forming coupler exhibiting a Status A red density sufficiently greater than 0.23 to improve the flesh tone reproduction of the element, compared to the same element containing a magenta dye-forming coupler exhibiting a red density of less than 0.23, as measured using a green light separation exposure at a green density of 1.0.
It is important to closely match the coupler reactivity when blending couplers. Mis-matched blended coupler reaction rates with oxidized color developer will result in color shifts through the neutral density scale. Reactivity mismatches can also result in unacceptable color reproduction performance. Ideally the coupler blends would react to form one blended dye spectra that forms the same blended dye spectra up and down the density scale. In practice some deviation from one blended dye spectra can occur. If the dye spectra deviation is not too large the tone scale neutrality and color reproduction properties will be acceptable.
Embodiments of the invention may provide a combination of improved flesh tone reproduction and image stability. In such cases, the use of an NB 2,5-diacylamino phenolic coupler and the pyrazolotriazole coupler with a tetramethylethyl link is preferred.
A useful embodiment of the invention incorporates a block copolymer of polyoxypropylene and polyoxyethylene in one of the layers such as in the overcoat. Examples of such materials are described in U.S. Pat. No. 5,491,052 and include Pluronic L44 of BASF Corp.
An “NB coupler” is a narrow bandwidth coupler having substituents so that there is a reduction in left bandwidth in spin-coating form vs. solution form of at least 5 nm. In accordance with the procedure, a dye is formed by combining the coupler and the developer 4-amino-3-methyl-N-ethyl-N-(2-methanesulfonamidoethyl)aniline sesquisulfate hydrate. If the left bandwidth (LBW) of its absorption spectra upon “spin coating” of a 3% w/v solution of the dye in di-n-butyl sebacate solvent is at least 5 nm. less than the LBW for a solution of the same dye in acetonitrile, then the coupler is an “NB Coupler”. The LBW of the spectral curve for a dye is the distance between the left side of the spectral curve and the wavelength of maximum absorption measured at a density of half the maximum.
The “spin coating” sample is prepared by first preparing a solution of the dye in di-n-butyl sebacate solvent (3% w/v). If the dye is insoluble, dissolution is achieved by the addition of methylene chloride. The solution is filtered and 0.1-0.2 ml is applied to a clear polyethylene terephthalate support (approximately 4 cm×4 cm) and spun at 4,000 RPM using the Spin Coating equipment, Model No. EC101, available from Headway Research Inc., Garland Tex. The transmission spectra of the so prepared dye samples are then recorded.
Preferred “NB couplers” form a dye which, in n-butyl sebacate, has a LBW of the absorption spectra upon “spin coating” which is at le
Brown Glenn M.
Ellinger Carolyn R.
Fitzgerald Cynthia A
Flow Vincent J.
Hendricks Jess B.
Eastman Kodak Company
Kluegel Arthur E.
Letscher Geraldine
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