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
2003-04-29
Letscher, Geraldine (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Radiation sensitive product
Two or more radiation-sensitive layers containing other than...
C430S552000, C430S553000, C430S558000, C430S523000, C430S631000
Reexamination Certificate
active
06555304
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a direct view silver halide photographic element containing a particular red record that contains a desirable combination of couplers.
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 unduly under dark conditions are undesirable. It is a therefore a desire to provide the foregoing flesh reproduction 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 has also been suggested to use a combination of phenolic couplers in a red record in U.S. Pat. No. 5,047,314.
It is a problem to be solved to provide a direct view multicolor element that provides improved flesh tone reproduction and good dye dark stability.
SUMMARY OF THE INVENTION
The invention provides a silver halide direct view multicolor photographic element comprising a red record containing (1) a red light sensitized silver halide emulsion, (2) a cyan dye-forming NB first coupler, and (3) a second coupler selected from (a) a magenta dye forming coupler in an amount of 2-30 mole % of the total coupler in the red record and (b) a cyan dye-forming coupler having a greater absorption in the green spectra than the first coupler in an amount sufficient to provide a Status A green density in the range of 0.27 to 0.40 using a red light separation exposure at a Status A red density of 1.0.
Embodiments of the invention provide direct view elements that exhibit improved flesh tone reproduction and good dye dark stability.
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 red record to enable an improved flesh tone reproduction and good dye dark stability.
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 least 15 nm, preferably at least 25 nm, less than that of the same dye in acetonitrile solution.
In the invention, the photographic element comprises a red record containing a red light sensitized silver halide emulsion, a cyan dye-forming NB coupler, and at least one of (a) a magenta dye forming coupler or (b) a cyan dye-forming coupler having a greater absorption in the green spectra than the first coupler. Such a coupler is typically not an NB coupler. The cyan dye-forming second coupler to be included in the cyan layer is one sufficient to provide for the record a status A green density of 0.27-0.40 using a red light separation exposure at a red density of 1.0. The value is typically in the range of 0.29-0.38.
The cyan dye-forming coupler useful to be included in the cyan record is a phenolic, naphtholic or pyrroloazole coupler. A particularly useful phenolic coupler is a 2,5-diacylamino phenol, or a 2-ureido-5-acylamino phenol. The amount of the cyan dye-forming second coupler to be included in the red record is suitably in the amount of 5-75 mole % of the couplers in the record and typically 10-65 mole %.
The magenta dye-forming coupler in the cyan record is suitably any magenta dye-forming coupler, such as an azole coupler. Examples are pyrazolone and pyrazoloazole couplers. One type of suitable coupler is a pyrazolotriazole coupler, particularly one with a tetramethylethyl link. Examples of pyrazolo couplers include a 1H-pyrazolo (5,1-c) [1,2,4] triazole or a 1H-pyrazolo (1,5-b) [1,2,4] triazole compound. The amount of the magenta coupler in the cyan record is suitably in the range of 2-30 mole % of the couplers in the record with 2-25 or 5-20% typically preferred.
The magenta dye-forming coupler to be used 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 one desirable 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.
In another desirable embodiment of the invention, the green record contains 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.
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
Brown Glenn M.
Ellinger Carolyn H.
Fitzgerald Cynthia A.
Flow Vincent J.
Harder John H.
Eastman Kodak Company
Kluegel Arthur E.
Letscher Geraldine
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