In a simple construction, a conventional color negative film intended for in camera exposure typically takes the following form:
______________________________________ CNF-I ______________________________________ OC BRLU YFL GRLU IL RRLU AHL TRANSPARENT FILM SUPPORT ______________________________________
On the transparent film support are coated in the order shown, a series of processing solution penetrable hydrophilic colloid layers: antihalation layer AHL, a red recording layer unit RRLU containing a red sensitized silver iodobromide (AgIBr) emulsion and a cyan dye-forming coupler, an interlayer IL containing an oxidized developing agent scavenger, a green recording layer unit GRLU containing a green sensitized AgIBr emulsion and a magenta dye-forming coupler, a yellow filter layer YFL containing a Carey Lea silver or a processing solution decolorizable yellow filter dye and an oxidized developing agent scavenger, a blue recording layer unit BRLU containing blue sensitive (optionally blue sensitized) AgIBr emulsion and a yellow dye-forming coupler, and a transparent protective overcoat OC. In the simplest possible construction capable of producing a color negative image, all of the hydrophilic colloid layers, except BRLU, GRLU and RRLU can be omitted. In the overwhelming majority of practical applications all of the layers of CNF-I described above are employed and, most commonly, many additional addenda are incorporated for performance enhancement.
In their simplest possible construction each of BRLU, GRLU and RRLU contain a single AgIBr emulsion. However, as elaborated on in Research Disclosure, Vol. 389, September 1996, Item 38957, I. Emulsion grains and their preparation, E. Blends, layers and performance categories, paragraph (7), when a fast emulsion layer is coated over a slow emulsion layer, an increase in imaging speed without an offsetting increase in granularity can be realized. Therefore, it is common practice to double-coat or triple-coat by splitting the AgIBr emulsions in BRLU, GRLU and RRLU into two or three separate emulsion layers differing in imaging speed.
A typical double-coated color negative film construction can take the following form:
______________________________________ CNF-II ______________________________________ OC BRLU Fast blue recording emulsion layer Slow blue recording emulsion layer YFL GRLU Fast green recording emulsion layer Slow green recording emulsion layer IL RRLU Fast red recording emulsion layer Slow red recording emulsion layer AHL TRANSPARENT FILM SUPPORT ______________________________________
Since this arrangement locates the fast green and fast red emulsion layers beneath slow emulsion layers, alternative arrangements have been suggested from time to time, such as illustrated by the following:
______________________________________ CNF-III ______________________________________ OC Fast BRLU IL Fast GRLU IL Fast RRLU IL Slow BRLU YFL Slow GRLU IL Slow RRLU AHL TRANSPARENT FILM SUPPORT ______________________________________
This arrangement differs from CNF-II in that it separates the fast and slow emulsion layers in each recording layer unit of CNF-II into separate recording layer units with the fast recording layer units located to receive exposing radiation prior to the slow recording layer units, but it does not succeed entirely in protecting the green and red exposure records from blue light contamination, attributable to the native blue sensitivity of the AgIBr emulsions in the fast green and red recording layer units.
An alternative construction is disclosed by Eeles and O'Neill U.S. Pat. No. 4,184,876, as illustrated by the following:
______________________________________ CNF-IV ______________________________________ OC BRLU YFL Fast GRLU IL Fast RRLU IL Slow GRLU IL Slow RRLU AHL TRANSPARENT FILM SUPPORT ______________________________________
The blue recording layer unit can be constructed as in CNF-I or CNF-II. The yellow filter layer YFL is located to protect all of the green and red recording layer units from exposure to blue light. The positioning of the fast red recording layer unit Fast RRLU above the slow green recording layer unit Slow GRLU results in a significant increase in the red speed of the color negative film while degrading the acutance (sharpness) of the green image record only slightly.
The Kodak Flexicolor.TM. C-41 process is commonly employed for processing imagewise exposed color negative films. Since minor adjustments of the C-41 process are undertaken from time to time, the following detailed description is provided:
______________________________________ Develop 3'15" Developer 37.8.degree. C. Bleach 4' Bleach 37.8.degree. C. Wash 3' 35.5.degree. C. Fix 4' Fixer 37.8.degree. C. Wash 3' 35.5.degree. C. Rinse 1' Rinse 37.8.degree. C. ______________________________________ Developer Water 800.0 mL Potassium Carbonate, anhydrous 34.30 g Potassium bicarbonate 2.32 g Sodium sulfite, anhydrous 0.38 g Sodium metabisulfite 2.96 g Potassium Iodide 1.20 mg Sodium Bromide 1.31 g Diethylenetriaminepentaacetic acid 8.43 g pentasodium salt (40% soln) Hydroxylamine sulfate 2.41 g N-(4-amino-3-methylphenyl)-N-ethyl- 4.52 g 2-aminoethanol Water to make 1.0 L pH @ 26.7.degree. C. 10.00 +/- 0.05 Bleach Water 500.0 mL 1,3-Propylenediamine tetra- 37.4 g acetic acid 57% Ammonium hydroxide 70.0 mL Acetic acid 80.0 mL 2-Hydroxy-1,3-propylenediamine 0.8 g tetraacetic acid Ammonium Bromide 25.0 g Ferric nitrate nonahydrate 44.85 g Water to make 1.0 L pH 4.75 Fix Water 500.0 mL Ammonium Thiosulfate (58% solution) 214.0 g (Ethylenedinitrilo)tetraacetic acid 1.29 g disodium salt, dihydrate Sodium metabisulfite 11.0 g Sodium Hydroxide (50% solution) 4.70 g Water to make 1.0 L pH at 26.7.degree. C. 6.5 +/- 0.15 Rinse Water 900.0 mL 0.5% Aqueous p-tertiary-octyl-(.alpha.- 3.0 mL phenoxypolyethyl)alcohol Water to make 1.0 L ______________________________________
USPTO Backgrounds
USPTO Backgrounds