US3672898A - Multicolor silver halide photographic materials and processes - Google Patents

Abstract

ESSES UTILIZING THE ELEMENTS OF THE INVENTION ARE ALSO DESCRIBED.

MULTICOLOR PHOTOGRAPHIC ELEMENTS ARE PROVIDED WHICH CONTAIN YELLOW, MAGENTA AND CYAN DYE FORMING UNITS, EACH OF THE UNITS HAVING A RELATIVE LOG SPECTRAL SENSITIVITY DISTRIBUTION SUCH THAT ACCEPTABLE NEUTRALS AND GOOD COLOR RENDITION ARE OBTAINED UPON EXPOSURE OF THE FILM TO ANY ONE OF A VARIETY OF ILLUMINANTS, SUCH AS DAYLIGHT, TUNGSTEN OR FLUORESCENT ILLUMINANTS. THE SPECTRAL DISTRIBUTION OF EACH DYE FORMING UNIT IN ACCORDANCE WITH THE INVENTION IS SHOWN IN FIGS. 1-3 AND TABLES I-III HEREOF. PHOTOGRAPHIC PROC-

Description

June 27, 1972 MULTICOLOR SILVER HALIDE PHOTOGRAPHIC MATERIALS AND PROCESSES Filed Sept. 29, 1969 YELLOW DYE FORM/N6 U/V/7'.

6 Sheets-Sheet l L06 SENS/Tl V/TY 600 1 nm (.t 5)

JUDITH A. SCHWA/V JAMES L. GRAHAM INVENTORS A T TOR/V5 Y June 27, 1972 J, scHw ETAL 3,672,898

MULTICOLOR SILVER HALIDE PHOTOGRAPHIC MATERIALS AND PROCESSES Filed Sept. 29, 1969 6 Sheets-Sheet 2 MAGENTA DYE FORM/N6 UNIT X /5/ 0 E 0; (/)-/0% a (09) 9% a (.08) 8% (on- 7% Q Q \l JUD/TH A. SCHWA/V JAMES L. GRAHAM INVENTORS BY 41 41, #1]. L V ,qy

A T TOR/VEY J1me 1972 J. A. SCHWAN ETAL 3,672,898

MULTICOLOR SILVER HALIDE PHOTOGRAPHlC MATERIALS AND PROCESSES Filed Sept. 29, 1969 6 Sheets-Sheet 5 X /5% t L E (//-/0% .09) 9% /.08)8

.0/ f j 450 500 550 600 650 700 nm(: 5)

FIG 3 JUDITH A SCHWA/V JAMES L. GRAHAM INVENTORS A 7' TORNE Y June 27, 1972 J. A. SCHWAN ETAL 3,672,898

MULTICOLOR SILVER HALIDE PHOTOGRAPHlC MATERIALS AND PROCESSES Filed Sept. 29, 1969 6 SheetsSheet 4 YELLOW FUER DYE-FORMING BL UE SE/VS/T/VE EMULS/O/V T F/L rm MAGENTA DYE- FORM/N6 GREEN SENSITIVE EMULS/O/V U/v/r F/L TE}? CYA/V 50 SENS/Tl v5 EMULSION D Z ZQ SUPPORT JUDITH A. SCHWAN JAMES L. GRAHAM INVENTORS BY 6,, MM

A 7' TORNEY June 27, 1972 J. A. SCHWAN ETAL 3,572,398

MULTICOLOR SILVER HALIDE PHOTOGRAPHIC MATERIALS AND PROCESSES 6 Sheets-Sheet 5 Filed Sept. 29, 1969 ULTRAVIOLET AND BLUE ABSORB/NG F/LTER 0 0 \L twamq #Gt mm JUDITH A. scHwA/v JAMES L GRAHAM INVENTORS 0 L 0 W 7 M L m L w 6 S L M R V Y P. m k M F 6H m M N N M z mm l m L E X M L ow 2 a w 0 0 0 x .QWEIMQ 332k 06 A TTORNEY 6 Sheets-Sheet 6 J. A. SCHWAN ETAL YELLOW FILTER MULTICOLOR SILVER HALIDE PHOTOGRAPHIC MATERIALS AND PROCESSES JUD/TH A. SCHWAN JAMES L. GRAHAM INVENTORS ATTORNEY WAVELENGTH //V M/LL/M/CRO/VS F IG 6 June 27, 1972 Filed Sept. 29, 1969 United States Pat Ofice 3,672,898 Patented June 27, 1972 3,672,898 MULTICOLOR SILVER HALIDE PHOTOGRAPHIC MATERIALS AND PROCESSES Judith A. Schwan and James L. Graham, Rochester, N.Y., assignors to Eastman Kodak Company, Rochester, N.Y. Continuation-impart of application Ser. No. 715,005, Mar. 21, 1968. This application Sept. 29, 1969, Ser. No. 864,275

Int. Cl. G03e 1/76, 1/84, 1/10 US. C]. 96-74 42 Claims ABSTRACT OF THE DISCLOSURE This application is a continuation-in-part of our copending US. patent application Ser. No. 715,005, filed Mar. 21, 1968, now abandoned.

This invention relates to photographic elements and processes. In one aspect, it relates to photographic elements which provide subtractive multicolor dye images. In another aspect, it relates to certain novel photographic dye-forming units. In still another aspect this invention relates to photographic processes.

Since the human visual system adapts to a wide variety of illuminant conditions, most colors appear to change only to a minor degree as the color quality of the illuminant changes. Photographic systems are much less versatile in this respect.

For a color film to reproduce colors approximately as the eye sees them, its responses to red, green and blue parts of white light must bear the same relation to each other as do the responses of the eye to these same colors. If the film has relatively too much sensitivity to red light, for example, red objects in the scene will appear much too light in the color reproduction, assuming that the exposure is correct for green and blue objects, and white objects will appear reddish.

Matching the color sensitivity of the eye would be simpler for the film if the three receptor systems involved in human vision were constant in their response to light. The actual situation, however, is that the receptors shift in relative sensitivity as the eye adapts to prevailing illumination. As one goes from daylight to weaker and yellower tungsten light, for example, the sensitivities of all three receptors increase, but the sensitivity to blue light increases to a much greater extent than the sensitivity to red light, thus partially compensating for the lower proportion of blue in tungsten light. In the less common situation where the tungsten light is stronger than the daylight, the receptor sensitivities of the eye decrease, but the sensitivity to blue light decreases less than the sensitivity to red light.

This type of adaptation is a convenience in everyday life. It reduces our consciousness of the color variation of illumination and thus tends to make the apparent colors of objects approximately constant. Color films, however, are necessarily limited in their response to a single adaptation level, or in other words, they have a certain color balance which is determined at the time of their manufacture. Color films do not automatically shift in sensitivity, but rather see a scene only with respect to one particular sensitivity.

Not only do daylight and the various types of artificial light differ in color quality, but individually each is subject to considerable variation. For example, two extremes of illumination which occur on a clear day are the reddish sunlight late in the afternoon and the bluish skylight reaching a shaded subject.

While some compensation for the difierences in color reproduction of color negative films has been made in the printing stage so that the prints become satisfactory representations of the original scene, no such compensation can be made for color reversal films for the effect of the color of the exposing light. Therefore, it has been desired to obtain a single color film, the color sensitivities of which minimize the effects of illuminant color differences, for acceptable representation of all scenes. Such a film should provide acceptable color rendition Whether exposed to tungsten, fluorescent or daylight illumination. These films are referred to herein as STF films. In the phrase STF, S refers to sunlight, including all daylight conditions; T refers to tungsten; and, F refers to fluorescent. STF films provide acceptable color balance, including good neutrals, upon exposure to daylight, tungsten or fluorescent illumination.

No disclosure has been found in the prior art of a suitable method for making acceptable STF films. Suggestions have been made which would allegedly improve the color rendition of a film when exposed under ditfering daylight conditions. See, for example, Schneider US. Pat. 2,343,- 424, issued Mar. 7, 1944. However, color films modified as suggested by Schneider cannot properly be regarded as STF films since they do not give acceptable color renditions when exposed to such differing illuminants as daylight, tungsten or fluorescent sources.

Suggestions have also been made for modifying the red sensitization of the cyan dye-forming color unit of multicolor films so that they will record certain blue colors, such as the heavenly blue morning glory, as blue rather than pink. See, for example, German Pat. 1,113,873, issued Sept. 14,1961. However, the mere fact that a color film will accurately record such blue tints does not mean that it is an STF film. Thus, the other color forming units of the film must be properly sensitized and the red sensitive layer itself, although properly reproducing blue tints such as those of the heavenly blue morning glory, must meet certain other criteria.

One object of this invention is to provide novel photographic elements and processes.

Another object of this invention is to provide novel photographic elements and processes which provide good color rendition and acceptable neutrals upon exposure under any of a variety of illuminants, such as sunlight, tungsten or fluorescent.

A further object of this invention is to provide novel photographic dye-forming units.

Still another object of this invention is to provide photographic silver halide emulsions containing novel combinations of sensitizing dyes.

Other objects of this invention will be apparent from the following description and the appended claims.

Applicants have now found that STF films for subtractive color photography can be prepared through the selective spectral sensitization of blue, green and red sensitive emulsion layers of a color film which, in cooperation with certain yellow-ultraviolet, yellow and magenta filters provide yellow, magenta and cyan dye-forming units which produce good acceptable subtractive color rendition upon exposure to any of a variety of common illuminants, including daylight, tungsten and fluorescent sources.

An understanding of the present invention will be facilitated by reference to the accompanying drawings. FIGS. 1, 2 and 3, respectively, show the tolerances for the relative log spectral sensitivity responses for the blue sensitive, yellow dye-forming unit; the green sensitive, magenta dye-forming unit; and, the red sensitive, cyan dye-forming unit. FIGS. 5, 6 and 7, respectively, show the preferred adsorption characteristics of the yellowultraviolet, yellow colored and magenta colored filters. FIG. 4 shows, in greatly enlarged cross section, a multilayer color film in accordance with the invention comprising a support having coated thereon a red sensitive photographicsilver halide emulsion layer 2, which in cooperation with filter layer 3, forms the cyan dye-forming unit; a green sensitive photographic silver halide emulsion layer 4 which, in cooperation with layer 5, forms the magenta dye-forming unit; and a blue sensitive photographic silver halide emulsion layer 6 which, in cooperation with filter layer 7, forms the yellow dye-forming unit. As noted hereinafter, filter layer 7 does not have to be an integral part of the photographic element. Rather, filter layer 7 can,- if desired, be employed separate from the photographic element, for example, as a camera filter.

' In FIGS. 1, 2 and 3, the relative log sensitive (ordinate) of the respective dye-forming units are plotted against wavelength (abscissa) in nanometer (nm.) units. The logarthmic units appear in parenthesis on the ordinate, indicating relative sensitivity for any given wavelength on the abscissa. Percentages are noted along the ordinate so that reference can be made to the relative log spectral sensitivity characteristics at various levels (percentages) below maximum sensitivity.

In referring to FIGS. 1, 2 and 3 herein, it is to be understood that the wavelengths given on the abscissa in nm. units can be raised'or lowered by a factor of nm. FIGS. 1, 2 and 3 define theacceptable spectral sensitivity tolerances of the three dye-forming units employed in the elements of the invention. STF films are provided in accordance with this invention when the relative log sensitivity to radiation of each unit is a smooth, continuous curve which falls within the area defined between the two curves in FIGS. 1, 2 and 3.

The upper 98% of the relative log spectral sensitivity response of the color forming units of the invention is described in FIGS. 1, 2 and 3, and in Tables I, II and HI below. The upper 90% of response appears to be the most important in achieving the objects of the present invention. Improved results are achieved if each colorforming unit meets the full criteria set out herein, i.e., the upper 98% of the log spectral sensitivity response. It will be understood, however, that in certain applications an even larger area, approaching 100% of the log spectral sensitivity response, will be important. In such instances, the criteria set out herein can be extended to provide the desired results.

As used herein and in the appended claims, smooth, continuous curve refers to curves which are essentially free from flat areas, or abrupt, irregular changes, such as an irregular and excessively high or low sensitivity to radiation of certain wavelength. The term smooth, continuous curves, as used herein, refers to curves which have essentially the same regular curve shapes as those which appear in FIGS. 1, 2 and 3.

The word about as used herein to describe radiation of a particular wavelength in nanometer (nm.) units is understood to be plus or minus five (:5) nanometers.

In accordance with one embodiment of this invention, a photographic element is provided comprising the following dye-forming units carried on a support:

(1) a yellow dye-forming unit having at least one light sensitive layer comprising silver halide grains which exhibit highest sensitivity to radiation longer than 445 nm., and are sensitive to radiation between about 441 nm. to about 458 nm.; about 429 nm. to about 472 nm.; and about 412 nm. to about 498 nm. at 80%, 40% and 10%,

respectively, of a sensitivity of the emulsion to radiation of about 450 nm.; said silver halide grains, at least when exposed to radiation which first passes through an ultraviolet and blue absorbing filter material which absorbs substantially all radiation shorter than about 375 nm. to which the silver halide grains are sensitive and selectively absorbs radiation longer than about 375 nm.:

(a) have maximum relative log sensitivity to radiation of about 450 nm.;

(b) are sensitive to radiation having a wavelength from about 441 nm. to about 458 nm., and are substantially insensitive to radiation shorter than about 433 nm. and longer than about 473 nm., at of said maximum relative log sensitivity;

(c) are sensitive to radiation having a wavelength from about 429 nm. to about 472 nm., and are substantially insensitive to radiation shorter than about 416 nm. and longer than about 493 nm., at 40% of said maximum relative log sensitivity;

(d) are sensitive to radiation having a Wavelength from about 412 nm. to about 498 nm., and are substantially insensitive to radiation shorter than about 389 nm. and longer than about 525 nm., at 10% of said maximum relative log sensitivity; and,

(e) produce a smooth, continuous relative log spectral sensitivity response curve;

(2) a magenta dye-forming unit having at least one light sensitive layer comprising spectrally sensitized silver halide grains which exhibit highest spectral sensitivity to radiation longer than 539 nm., and are sensitive to radiation between about 528 nm. to about 557 nm.; about 507 nm. to about 573 nm.; and, about 481 nm. to about 594 nm. at 80%, 40% and 10% respectively, of a spectrally sensitized sensitivity of the emulsion to radiation of about 544 nm.; and, yellow colored filter material which selectively adsorbs visible radiation shorter than said highest sensitivity so that when said silver halide grains are exposed by light which first passes through said yellow dyeforming unit and said yellow colored filter material, said grams:

(a) have maximum relative log sensitivity to radiation of about 544 nm.;

(b) are at least sensitive to radiation having a wavelength from about 528 nm. to about 557 nm., and are substantially insensitive to radiation shorter than about 522 nm. and longer than about 565 nm., at 80% of said maximum relative log sensitivity;

(c) are at least sensitive to radiation having a wavelength from about 507 nm. to about 573 nm., and are substantially insensitive to radiation shorter than about 493 nm. and longer than about 588 nm., at 40% of said maximum relative log sensitivity;

(d) are at least sensitive to radiation having a wavelength from about 481 nm. to about 594 nm., and are substantially insensitive to radiation shorter than 462 nm. and longer than about 620 nm., at 10% of said maximum relative log sensitivity; and,

(e) produce a smooth, continuous relative log spectral sensitivity response curve; and,

(3) a cyan dye-forming unit having at least one light sensitive layer comprising spectrally sensitized silver halide grains which exhibit highest spectral sensitivity to radiation longer than 603 nm., and are senstive to radiation between about 595 to about 620 nm., about 580 to about 633 nm. and about 561 nm. to about 654 nm., at 80%, 40% and 10%, respectively, of a spectrally sensitized log sensitivity of the emulsion to radiation of about 608 nm.; and, magenta-colored filter material which adsorbs visible radiation shorter than said highest sensitivity so that when said silver halide grains are exposed by light which first passes through said yellow and magenta dye-forming units, and said magenta-colored filter material, the grains:

(a) have maximum relative log sensitivity to radiation of about 608 nm.;

(b) are at least sensitive to radiation having a wavelength from about 595 nm. to about 620 nm., and are substantially insensitive to radiation shorter than about 587 nm. and longer than about 627 nm., at 80% of said maximum relative log sensitivity;

(c) are at least sensitive to radiation having a wavelength from about 5 80 nm. to about 633 nm., and are substantially insensitive to radiation shorter than about 561 nm. and longer than about 655 nm., at 40% of said maximum relative log sensitivity;

(d) are at least sensitive to radiation having a wavelength from about 561 nm. to about 654 nm., and are substantially insensitive to radiation shorter than 536 nm. and longer than about 684 nm., at of said maximum relative log sensitivity; and,

(e) produce a smooth, continuous relative log spectral sensitivity response curve.

Such photographic elements provide good, acceptable color rendition whether exposed under daylight, tungsten or fluorescent illumination.

The yellow, magenta and cyan dye-forming units employed in this invention are described in Tables I-III below. These tables give the wavelengths of radiation to which each color forming unit is sensitive at specific percentages of maximum relative log spectral sensitivity. Dyeforming units which have a smooth, continuous relative log spectral sensitivity response curve that has the maximum sensitivity, and meets the sensitivity criteria in Tables I-III at 80%, 40% and 10% of maximum sensitivity, are suitable for use in the STF films of the invention. All wavelengths given in Tables I-III may be varied by plus or minus 5 nm.

TABLE I.YELLOW DYE-FORMING UNIT [Maximum sensitivity: 450 nm.]

Sensitive to Insensitive to TABLE II.MAG ENIA DYE-FORMING UNIT [Maximum sensitivity: 544 nm.]

Sensitive to Insensitive to Percent of radiation (nm.) radiation (nm.) maximum seneitiv- Longer Shorter Shorter Longer ity thanthanthau than- TABLE III.-CYAN DYE-FORMING UNIT [Maximum sensitivity: 608 nm.]

Sensitive to Iusensitive to In another embodiment of this invention, a photographic element is provided which comprises the following dye-forming units coated on a support:

(a) a first blue-sensitive, yellow dye-forming unit having a light sensitive layer comprising silver halide grains which have a relative log spectral sensitivity response to radiation longer than approximately 445 nm. at least as great as the response of curve BE in FIG. 1, said grains, at least when exposed through an ultraviolet and blue absorbing filter which selectively adsorbs ultraviolet and blue radiation, exhibit an effective relative log spectral sensitivity distribution which has a smooth, continuous curve which falls within the area defined between curves ABC and DBE of FIG. 1 when exposed to light which first passes through the filter;

(b) a second green-sensitive, magenta dye-forming unit having a light sensitive layer comprising silver halide grains which have a relative long spectral sensitivity response to radiation longer than approximately 539 nm. at least as great as the response of curve G] of FIG. 2. and, a yellow-colored filter which selectively adsorbs blue and green radiation; said filter and said light sensitive layer cooperating to provide an effective relative log speetral sensitivity distribution which has a smooth continuous curve which falls within the area defined between curves FGH and IG] of FIG. 2 When said light sensitive layer is exposed to light which first passes through the yellow filter and said yellow dye-forming unit;

(0) a third red-sensitive, cyan dye-forming unit having a light sensitive layer comprising silver halide grains which have a relative log spectral sensitivity response to radiation longer than approximately 603 nm. at least as great as the response of curve LO of FIG. 3, and, a

magenta-colored filter which selectively adsorbs green and red radiation; said filter and said light sensitive layer cooperating to provide an effective relative log spectral sensitivity distribution which has a smooth, continuous curve which falls within the area defined between curves KLM and NLO of FIG. 3 when the light sensitive layer is exposed to light which first passes through said magenta-colored filter and said yellow and said magenta dyeforming units.

In still another embodiment of this invention, novel cyan, magenta and yellow dye-forming units are provided as described herein.

In accordance with another embodiment of this invention, a photographic element having the yellow, magenta and cyan dye-forming units described herein is exposed; silver images are developed in the silver halide emulsion layers of the photographic element; and, yellow, magenta and cyan dyes are generated in, respectively, the yellow, magenta and cyan dye-forming units of the element in proportion to the silver images produced. The process of this invention is particularly suitable when yellow, magenta and cyan dye forming photographic couplers are employed in the yellow, magenta and cyan dye forming units, reversal silver images are developed with a black and white photographic silver halide developer to provide a negative silver image, the undeveloped silver halide is fogged and the fogged silver halide is developed with a photographic color developing agent, such as a p-phenylene diamine color developing agent, to form yellow, magenta and cyan dye images in the unexposed areas of the blue, green and red sensitive emulsion layers of the yellow, magenta and cyan color forming units.

The ultraviolet and blue absorbing filter referred to herein can comprise an integral part of the photographic element. For example, the filter material can be employed in the blue sensitive silver halide emulsion layer or in a separate layer. Photographic elements can also be prepared in accordance with the invention in which the ultraviolet and blue absorbing filter is not an integral part of the photographic element. Such photographic elements are advantageously exposed through an ultraviolet and blue absorbing filter which cooperates with the silver halide grains in the yellow dye-forming unit to provide a relative log spectral sensitivity distribution of the type described herein for the yellow dye forming unit. Of course, when such photographic elements are exposed to radiation which has low quantities'of ultraviolet and a blue radiation, for example tungsten illumination, it is unnecessary to expose the elements through an ultraviolet and blue absorbing filter to obtain acceptable color balance. Accordingly, elements of the invention which do not contain an integral ultraviolet and blue absorbing filter are particularly suitable for use in cameras in which an ultraviolet and blue absorbing filter material can be employed when exposure is made to illumination rich in blue and ultraviolet radiation, such as exposures made under daylight illumination.

In one preferred embodiment of this invention, the magenta dye-forming unit has at least one photographic silver halide emulsion layer having maximum spectral sensitivity at about 544 nm., and a relative log spectral sensitivityresponse to radiation longer than approximately 500 nm. within the area defined between curves 'UGH and T6] of FIG. 2 (and meets all criteria in Table II except for too high a sensitivity to radiation shorter than about 500 nm. at less than about 40% of maximum sensitivity. See col. 4 of Table II). Advantageously, an overlying yellow-colored filter is provided which selectively adsorbs radiation shorter than about 500 nm. whereby the elfective log spectral sensitivity response in the magenta color forming unit to radiation shorter than about 500 nm. falls within the area defined between curves EU and IT of FIG. 2 (and meets all the criteria of Table II, including the values for less than 40% in col. 4).

In another preferred embodiment of this invention the cyan dye-forming unit has at least one light sensitive photographic silver halide emulsion layer having maximum spectral sensitivity at about 608 nm., and a relative log spectral sensitivity response to radiation longer than approximately 570 nm. within the area defined between curves VLM and WLO of FIG. 3, (and meets all the criteria in Table III, except for too high sensitivity to radiation shorter than about 570 nm. at less than about 50% of maximum sensitivity. (See col. 4 of Table III.) Advantageously, an overlying magenta-colored absorbing filter layer is provided which selectively absorbs radiation shorter than about 570 nm. whereby the elfective log spectral sensitivity response of the unit to radiation shorter than approximately 570 nm., falls within the area between curves KV and NW of FIG. 3 (and meets all the criteria of Table III, including the values for less than 50% in col. 4).

Photographic color film which utilizes emulsions in the yellow dye-forming unit having a sensitivity greater than curve AB in FIG. 1 will result in reproductions in which shadows will appear too blue. Emulsions employed ,in the cyan dye-forming unit which are sensitive to radiation longer than that indicated in curve LM will have an overall reddish cast. Emulsions used in either the yellow, magenta or cyan dye-forming units which have a narrower log relative spectral sensitivity distribution than that shown in FIGS. 1-3 will appear, respectively, too blue, too green or too red for certain colors (i.e., colors corresponding to the wavelength to which the particular emulsion is sensitive) and will lack sufiicient blue, green or red for other colors.

The blue sensitive, yellow dye-forming unit employed in the photographic elements of this invention advantageously has at least one light sensitive layer comprising silvenhalide grains which have a relative log spectral sensitivity response to radiation longer than approximately 445 nm., at least as great as the response of curve BE in FIG. 1 (and the minimum sensitivies shown in col. 3 of Table I). Silver halide emulsions which have a relatively low iodide content, and which are not spectrally sensitized, generally do not have adequate response to longer wavelength radiation. Such emulsions normally have a lower relative log spectral sensitivity than that represented by curve BE in FIG. 1. However, non-spectrally sensitized silver halide emulsions can be used in the blue-sensitive emulsion layer when the silver halide comprises a sufiicient amount of iodide so that the emulsion has a response to radiation at least as great as curve BE of FIG. 1 (or that required in col. 3 of Table I). Generally, silver halide emulsions having an iodide content of at least 3 mole percent iodide, and preferably from about 4 to 8 mole percent iodide, provide good results when used in the light sensitive layer of the yellow dye-forming unit of the invention. Silver bromoiodide emulsions containing 4 to 8 mole percent iodide are i highly useful. When it is desirable to employ silver halide emulsions of lower iodide content, it is advantageous to .OIiF-t;

Dye 11-Anhydro 5-ohloro3'-ethyl-3- (4-sulfobutyl) thlacyanlne hydroxide CHaCHzCHzCHzSOg Dye 12--1-ethyl-2- [2- p-anisylamlno) propylidene] -flnaphthothiazoline Dye 13-5- etl1y1-2-benzothiazolinylidene) -3fisulfoethylrhodanine C2115 Dye 14-3-carboxymethyl-5- (3-ethyl-2 (3H) -beuzothlazolylldene) rhodanine CzHs Dye 15-55-diclilo1'o3,3"diethylthiucyanine iodide Dye 16-2- (34nethyl-2 (3H) -benmothiazolylidene) -3- (2H) -benzofuranoue Dye 17 --1-ethyl-2- [2- a-naphthylimino) propylidene] fi-naphtliothiazoline l C 2H5 Dye 18-2-[2 (B-naphthylamino) propenyl] naphthothiazole ethiodide Dyo iii-Anhydro-Q- ['2- (p-anisidino)propenyl] -1- ('3-sulfopropyl) -naplitl1o [1,2d]thiazoli um hydroxide U as)...

The silver halide emulsions employed in the blue sensitive layer normally have an undesirably high response to radiation shorter than approximately 445 nm. Referring to FIG. 1, silver halide emulsions have a higher relative log spectral sensitivity response to radiation greater than that response plotted on curve AB. In Table I, the response will be greater than the values shown in col. 4. This excessive response to the shorter wavelength radiation, unless corrected, would result in pictures which are too yellow when exposed to tungsten radiation; or, pictures which are too blue when exposed to daylight radiation. The emulsion employed sometimes has, in addition, an excessively high response to longer wavelength radiation, such as a response greater than the response shown in FIG. 1, curve BC (or greater than the response indicated in col. 5 of Table I). This excessive response to longer or shorter radiation than that specified in Table I or FIG. 1 is corrected in accordance with the present invention by employing an ultraviolet and blue absorbing filter, which can be coated as a layer over the silver halide emulsion layer, or employed as a separate filter, e.g., a camera filter. The filter contains a sufiicient amount of dye to selectively adsorb radiation to correct the response of the emulsion to radiation between about 350 and 550 nm. or within the area defined between curves ABC and DBE of FIG. 1, and within the limits described in Table I.

The filter may be composed of one or more dyes, the preferred arrangement being an ultraviolet-adsorbing dye and a dye which selectively absorbs blue radiation (i.e., a yellow-colored dye). The term ultraviolet absorber as used herein refers to a compound which has strong absorption of radiation generally below about 375 nm. Any of the known ultraviolet absorbers are useful, including the acenaphthenotriazoles of Sawdey U.S. Pat. 3,271,156, issued Sept. 6, 1966; the phenylbenzotriazole ultraviolet absorbers of Sawdey German Pat. 1,166,623, issued Mar. 26, 1964; or, the ultraviolet absorbers of Hiller et al. U.S. Pat. 3,004,896, issued Oct. 17, 1961; Sawdey French Pat. 1,359,924, issued Mar. 23, 1964; Fierke U.S. Pat. 2,691,579, issued Oct. 12, 1954; Sawdey et al. U.S. Pat. 2,719,086, issued Sept. 27, 1955; Oliver U.S. patent application Ser. No. 567,070, filed July 22, 1966; and, Weigel U.S. Pat. 2,798,004, issued July 2, 1957, the disclosures of which are incorporated herein by reference. An especially useful group of ultraviolet absorbers are described in Graham Canadian Pat. 754,094, issued Mar. 7, 1967, at page 1, lines 16- through page 5, line 4, which disclosure is also incorporated herein by reference. It will be appreciated by those skilled in the art that when gelatin is employed as binder for the filter dyes in the yellow dye-forming unit, the gelatin itself will absorb some ultraviolet radiation.

The filter used to correct the blue sensitive emulsion layer advantageously contains, in addition to an ultraviolet absorber, a suitable yellow colored dye. The function of this dye is to impart the desired spectral distribution to the yellow dye-forming unit. Any suitable yellow colored dye can be employed, such as blue trimmer dyes 2 [(3-cyan0-3-dodecylsulfonyl)allylideneJ-3-(3-sulfopropyl) thiazolidene, potassium salt; 2-[ (3-cyano-3,4- t-butylphenyl-sulfonyl)allylidene] 3 (3-sulfopropyl) thiazolidene, potassium salt; 1-methyl-2,6-bis[(1,3,5-trimethyl-4-pyrazolyl)vinyllpyridinium iodide; 4-(3-ethyl- Z-benzothiazolinylidene)-3-heptadecyl 1 (4 sulfo-2- tolyl)-2-pyrazolin-5-one; and bis(1,2-diphenyl-4-pyrazolidine-3,5-dione) monomethine oxonol.

The most useful filters for the yellow dye-forming unit have an optical density to radiation of up to about 480 nm. which falls within the shaded area between curves RS and TS in FIG. 5, or as indicated in Table IV below:

TABLE IV Absorption of filter for yellow dye-forming unit Radiation up to In the above table, as in Tables V and VI below, the optical density shows the amount of absorption of the filters at radiation of various wavelengths (plus or minus 5 nm.). The optical density given in Tables IV, V and VI can be converted to percent transmission by the density-transmittance table on pages 76 and 77 of Kodak Wratten Filters For Scientific and Technical Use, 22 ed., published by the Eastman Kodak Company, 1965. Filters for the yellow dye-forming unit which have a smooth, continuous curve (i.e., similar in shape to curves RS and TS, and which have the absorption characteristics shown in Table IV at optical densities of .1, .4, .8, and 1.0, are useful herein.

The yellow dye-forming units of this invention prevents shadows from appearing too blue when the element is exposed under daylight conditions.

The magenta dye-forming unit of the invention includes at least one light sensitive layer comprising silver halide grains that have a relative log spectral sensitivity response, to radiation longer than approximately 539 nm., at least as great as the response indicated in col. 3 of Table II, or that of curve GJ of FIG. 2. Such silver halide emulsions, which are spectrally sensitized to green radiation, have a response to radiation shorterthan approximately 539 nm. which is greater than the response indicated on curve FG of FIG. 2 or the minimum response indicated in col. 4 of Table II. The overall response of these emulsions can be corrected so that the response of this unit is brought within the limits specified in col. 4 and col. 2 of Table II, or the area defined between curves FGH and IGH of FIG. 2, by the use of an overlying filter layer which cooperates with the spectrally sensitized emulsion to selectively decrease the emulsions sensitivity to radiation shorter than approximately 539 nm. One feature of this invention is the provision of a combination of sensitizing dyes which imparts the correct spectral response to radiation longer than about 500 nm., i.e., the area defined between curves UGT and IGH of FIG. 2, thus requiring filter correction to lower the response of the emulsion to only those wavelengths shorter than about 500 nm.

A wide variety of dyes can be used to spectrally sensitize the green sensitive layer. At least one sensitizing dye is employed which imparts maximum sensitivity to radiation longer than approximately 539 nm., and at least one dye which imparts a relative log spectral sensitivity response curve at least as great as that of curve G] of FIG. 11, or to radiation longer than that shown in col. 3 of Table II. In the preferred embodiments of this invention, a combination of dyes is employed which includes at least one dye having the following general formula:

and at least one dye selected from the group consisting of a styryl dye base having the general formula:

Formula Ia and a merocyanine dye having the formula:

Formula II s Z: (3 6 4) l -1 said combination of dyes providing a log relative sensitivity responce to radiation longer than approximately 539 nm.

at least as great as the response of curve G] of FIG. 2, or at least as great as the response shown in col. 3 of Table II. Preferably, a combination of dyes is chosen which imparts a maximum sensitivity to the emulsion layer at about 544 nm. The dyes advantageously impart a spectral distribution which results in a smooth, continuous curve which falls between curves UGH and T6] of FIG. 2. Best results are obtained using two dyes having Formula I together with (l) a styryl dye, or (2) a merocyanine dye of Formula II.

In Formulas I, Ia and II above, L, L and L, each represents a methine group; such as =CH- or =C(R') represent alkyl, such as methyl, ethyl, propyl or butyl, alkoxy such as methoxy, ethoxy, propoxy or butoxy, or aryl such as phenyl; R and R are each independently selected from the class consisting of an alkyl group, including substituted alkyl (preferably a lower alkyl containing from 1 to 4 carbon atoms), e.g., methyl, ethyl, propyl, isopropyl, butyl, hexyl, cyclohexyl, decyl, dodecyl, etc., and substituted alkyl groups (preferably a substituted lower alkyl containing from 1 to 4 carbon atoms), such as a hydroxyalkyl group, e.g., p-hydroxyethyl, w-hydroxybutyl, etc., an alkoxyalkyl group, e.g., ,B-methoxyethyl, w-butoxybutyl, etc., a carboxyalkyl group e.g., S-carboxyethyl, w-carboxybutyl, etc., a sulfoalkyl group, e.g., ,8-sulfoethyl, w-sulfobutyl, etc., a sulfatoalkyl group, e.g., B-sulfatoethyl, w-sulfatobutyl, etc., an acyloxyalkyl group, e.g., fi-acetoxyethyl, 'y-acetoxypropyl, w-butyryloxybutyl, etc., an alkoxycarbonylalkyl group, e.g., fi-methoxycar-bonylethyl, w-ethoxycarbonylbutyl, etc., or an aralkyl group, e.g., benzyl, phenethy], etc., and

the like; R represents a value given for R or, when taken together with L an alkylene group of from 2 to 3 carbon atoms, such as ethylene or propylene; R and R" each represents an alkyl group of from 1 to 4 carbon atoms; 12 represents an integer of from 1 to 3; Z, Z, Z; and Z each represents the non-metallic atoms required to complete a heterocyclic ring of the type used in methine dyes and containing from 5 to 6 atoms in said ring. The heterocyclic ring can contain a second hetero atom selected from oxygen, sulfur, selenium or nitrogen. Typical representative nuclei include: a thiazole nucleus, e.g., thiazole, 4-methylthiazole, 4-phenylthiazole, 5- methylthiazole, 5-phenylthiazole, 4,5-dimethylthiazole, 4,5-diphenylthiazole, 4 (2 thienyl)thiazole, benzothiazole, 4-chlorobenzothiazole, 5-chlorobenzothiazole, 6- chlorobenzothiazole, 7-chlorobenzothi-azole, 4-methylbenzothiazole, S-methylbenzothiazole, 6-methylbenzothiazole, 5-bromobenzothiazole, 6-bromobenzothiazole, 6- phenylbenzothiazole, 5-phenylbenzothiazole, 4-methoxybenzothiazole, S-methoxybenzothiazole, 6-methoxybenzothiazole, 5-iodobenzothiazole, 6-iodobenzothiazole, 4- ethoxybenzothiazole, S-ethoxybenzothiazole, tetrahydrobenzothiazole, 5,6-dimethoxybenzothiazole, 5,6-dioxymethylene benzothiazole, S-hydroxybenzothiazole, 6-hydroxybenzothiazole, a-naphthothiazole, p-naphthothiazole, 5-methoxy-fi, 8-naphthothiazole, S-ethoxy-fi-naphthothiazole, 8 methoxy on naphthothiazole, 7-methoxyu-naphthothlazole, 4' methoxythianaphtheno 7,6',4, 5-th1azole, etc.; an oxazole ring, e.g., 4-methyloxazole,

13 methylpyridine, 4-methylpyridine, etc.; a quinoline ring, e.g., quinoline, 3-methylquinoline, S-ethylquinoline, 6- chloroquinoline, 8-chloroquinoline, fi-methoxyquinoline, etc.; a 3,3-dia1kylindolenine ring, e.g., 3,3-dimethylindolenine, 3,3-diethylindolenine, etc.; an imidazo ring, e.g., imidazole, l-alkylimidazole, 1 alkyl 4,5 dimethylimidazole, benzimidazole, l-alkylbenzimidazole, l-aryl- 5,6 dichlorobenzimidazole, l-alkylnaphthimidazole, 1- aryl B naphthimidazole, 1 alkyl methoxy oznaphthimidazole, etc., and the like; n represents an integer of from 1 to 3; and Q represents the non-metallic atoms required to complete a 5 to 6 membered heterocyclic nucleus, typically containing a hetero atom selected from nitrogen, sulfur, and oxygen, such as a 2-pyrazolin- S-one nucleus, e.g., 3-methyl-l-phenyl-Z-pyrazolin-S-one, 1 phenyl 2 pyrazolin 5 one, 1 (2 benzothiazolyl) 3 methyl 2 pyrazolin 5 one, etc.; an isoxazolone nucleus, e.g., 3 phenyl 5 (4H) isoxazolone, 3 methyl 5(4H) isoxazolone, etc.; an oxindole nucleus, e.g., 1 alkyl 2 oxindoles, etc.; a 2,4,6-triketohexahydropyrimidine nucleus, e.g., barbituric acid or 2- thiobarbituric acid as well as their l-alkyl (e.g., l-methyll-ethyl, 1- propyl, l-heptyl, etc.) or 1,3-dialkyl (e.g., 1,3- dimethyl, 1,3-diethyl, 1,3-dipropyl, 1,3-diisopropyl, 1,3- dicyclohexyl, 1,3-di(fl-methoxyethyl), etc.); or 1,3-diaryl (e.g., 1,3-diphenyl, 1,3 di(p chlorophenyl), 1,3-di(pethoxycarbonylphenyl), etc.), or l-aryl (e.g., l-phenyl, l-p-chlorophenyl, 1 p ethoxycarbonylphenyl, etc.) or 1-alkyl-3-aryl (e.g., 1 ethyl 3 phenyl, 1-n-heptyl-3- phenyl, etc.) derivatives; a rhodanine nucleus (i.e., 2thio- 2,4-thiabolidinedione series), such as rhodanine, 3-alkylrhodanines, e.g., 3-ethylrhodanine, 3-allylrhodanine, etc., 3-carboxyalkylrhodanines, e.g., 3 (2 carboxyethyl) rhodanine, 3 (4 carboxybutyDrhodanine, etc., 3-sulfoalkylrhodanines, e.g., 3 (2 sulfoethyl)rhodanine, 3- (3-sulfopropyl)rhodanine, 3 (4 sulfobutyl)rhodanine, etc., or 3-arylrhodanines, e.g., 3-phenylrhodanine, etc.; a 2-(3H)-irnidazo[l,2ra]pyridone nucleus; a 5,7- dioxo 6,7 dihydro 5 thiazole[3,2-a]pyrimidine nucleus, e.g., 5,7 dioxo 3 phenyl 6,7 dihydro 5- thiazolo[3,2-a]pyrimidine, etc.; a 2-thio-2,4-oxazolidinedione nucleus (i.e., those of the 2-thio-2,4(3H,5H)-oxazoledione series) e.g., 3 ethyl 2 thio 2,4 oxazolidinedione, 3 (2 sulfoethyl) 2 thio 2,4 oxazolidinedione, 3 (4 sulfobutyl) 2 thio 2,4- oxazolidinedione, 3 (3 carboxypropyl) 2 thio 2,4- oxazolidinedione, etc.; a thianaphthenone nucleus, e.g., 3 (2H) thianaphthenone, etc.; a 2-thio-2,5-thiazolidinedione nucleus (i.e., the 2-thio-2,5(3H,4H)-thiazoledione series), eg, 3 ethyl 2 thio 2,5 thiazolidinedione, etc.; a 2,4-thiazolidinedione nucleus, e.g., 2,4-thiazolidinedione, 3 ethyl 2,4 thiazolidinedione, 3-phenyl- 2,4 thiazolidinedione, 3 a naphthyl 2,4 thiazolidinedione, etc.; a thiazolidinone nucleus, e.g., 4-thiazolidinone, 3 ethyl 4 thiazolidinone, 3 phenyl 4 thiazolidinone, 3 a naphthyl 4 thiazolidinone, etc.; a 2 thiazolin 4 one nucleus, e.g., 2 ethylmercapto 2- thiazolin 4 one, 2 alkylphenylamino 2 thiazolin- 4-one, 2 diphenylamino 2 thiazolin 4 one, etc.; a 2 imino 4 oxazolidinone (i.e., pseudohydantoin) nucleus; a 2,4-imidazolidinedione (hydantoin) nucleus, e.g., 2,4 irnidazolidinedione, 3 ethyl 2,4 imidazolidinedione, 3 phenyl 2,4 irnidazolidinedione, 3-0:- napthyl 2,4 irnidazolidinedione, 1,3 diethyl 2,4- imidazolidinedione, 1 ethyl 3 phenyl 2,4 imidazolidinedione, 1 ethyl 3 a naphthyl 2,4 irnidazolidinedione, 1,3 diphenyl 2,4 irnidazolidinedione, etc.; a 2 thio 2,4 imidazolidinedione (i.e., 2-thiohydantoin) nulceus, e.g., 2 thio 2,4 irnidazolidinedione, 3-ethyl- 2 thio 2,4 irnidazolidinedione, 3-(4-sulfobutyl)-2- thio 2,4 irnidazolidinedione, 3 (2 carboxyethyl) 2- thio 2,4 irnidazolidinedione, 3 phenyl 2 thio 2,4- imidazolidinedione, 3 a naphthyl 2 thio 2,4- imidazolidinedione, 1,3 diethyl 2 thio 2,4 imidazolidinedione, 1 ethyl 3 phenyl 2 thio 2,4- imidazolidinedione, 1 ethyl 3 a naphthyl 2 thio- 2,4-imidazolidinedione, 1,3 diphenyl 2 thio 2,4- imidazolidinedione, etc.; a 2 imid-azolin 5 one nucleus, e.g., 2 propylmercapto 2 imidazolin 5 one, etc.; etc. (especially useful are nuclei wherein Q represents a heterocyclic nucleus containing 5 atoms in the heterocyclic ring, 3 of said atoms being carbon atoms, 1 of said atoms being a nitrogen atom, and 1 of said atoms being selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom).

Some highly useful dyes having general Formula I are listed below.

3,3'-diethyl-4-methyloxaselenazolocarbocyanine iodide l'-ethyl-3-methyl-4-pheny1selenazole-2'-cyanine iodide Anhydro-3-ethyl-3 (4-sulfobutyl) thiathiazolinocarbocyanine hydroxide 5,6-dichloro-1-p-diethylaminoethyl-3-ethyl-1,3,3-trimethylbenzimidazoloindocarbocyanine perchlorate 1,3 '-diethyl-3 ,10-ethylene-3-H-naphth 1,2-d] imidazolooxacarbocyanine iodide 1,7-ethylene-3-methyl-2-pyridothiazolinocarbocyanine iodide Some highly useful styryl dyes having general Formula Ia are listed below:

2- 4-dimethylaminostyryl benzothiazole 2-(4-diethy1aminostyryl)benzoselenazole 2-(4-dibutylaminostyryl)benzoxazole 2- 4-dipropylaminostyryl benzimidazole The following list includes representative useful dyes having Formula II:

3-carboxymethyl-5-[3-methyl-2-thiazolidinylidene) ethylidene] rhodanine 5-[ (349-carboxyethyl-2-thiazolidinylidene) ethylidene] -3- ethylrhodanine 3-methyl- 1-phenyl-4 1 ,3 ,3-trimethyl-2-indolinylidene ethylidene] -2-pyrazolin-5-one 4-[ (l-ethylnaphtho 1,2-d]thiazolin-2-ylidene)ethylidene1- 3-phenyl-2-isoxazolin-5-one 3- [3-ethyl-2-benzothiazolinylidene ethylidene] -1-phenyl- 2-indo1inone 1-(2-diethylaminoethyl) -5- [4-(3-ethyl-2-benzoxazolinylidene) -2-butenylidene] -3 -phenylbarbituric acid 5-( 1-butyl-4( 1H) -quinoly1idene) -3-carboxymethylrhodanine 3 1,3, 3-trimethyl-2-indolinylidene) ethylidene] irnidazo[ 1,2-a] pyridin-2 (3H)-one 3-ethyl-5-[ (3-,B-methoxyethyl-Z-benzothiazolinylidene) l-methylethylidene] -2-thio-2,4-0Xazolidinedione 5- (3 -ethyl-2-benzoaxazolinylidene) ethylidene] -3-sulfomethyl-Z-thio-2,4-oxazolidinedione I 2[ 3-ethyl-2-benzoxazolinylidene) ethylidene] benzo[b]- thiophen-3 (2H) -one 5- (3-ethyl-2-b enzoxazolinylidene) ethylidene] -3-pheny1- 2,4-thiazolidinedione 2[ (2-benzimidazolyl) imino] -3-ethyl-5-[ 3-methyl-2- thiazolidinylidene) ethylidene] -4-thiazolidinone 2[ (Z-benzothiazolyl) imino] -3-ethyl-5-[ 3-ethyl-2-benzoxazolinylidene) ethylidene] -4-thiazolidinone 2-diphenylamino-5- [3-ethy1-2-benzothiazolinylidene) ethylidene] -2-thiazolin-4-one 2-benzoylimino-3-ethyl-5- (3-ethyl-2-benzothiazolinylidene)ethy1idene] -4-oxazolidinone 3-ethyl-5- (3-ethyl-2-benzothiazolinylidene) ethylidene] l-phenylhydantoin 1- (2-diethylaminoethyl)-3-ethyl-5-[ (-3-methyl-2-thiozolidinylidene) ethylidene] -2-thiohydantoin 3-carboxymethyl-5- (3-ethyl-2-benzoazolinylidene) ethylidene]-1-pheny1-2-thiohydantoin 2-benzoylimino-3-ethyl-5- (3-ethyl-Z-benzothiazolinylidene) ethylidene]-1-phenyl-4-imidazolidinone Some typical preferred dyes which are included in Formula I that can be employed as spectral sensitizers for the light sensitive layer of the magenta dye-forming unit include:

Dye 21-'Anhy.dro-.1-ethyl-3- 3sulfobutyl thia-2-cyanine droxid fobutylbenzimidazolocarbocyanine hydroxide tcnsis i 94 0:11

Dye 24.-Anihydlro-5,5,6,6-tetraohlono-1,1",3-nriethyl-3- (3.- sulfobutyl benzimidazoloearbocyanine hydroxide C2115 2 5 01 -o1 CCH=CH-CH=C 01 N/ -01 Dye '25tAn|l1ydro-5,6-dlchl0ro-1,3'-diethyl-3- 8-sulfopropy1) benzimidazolooxacarbocyanine hydroxide CCH=CHCH=C s omcmornsoa (Jim Dye 26Anhyd'ro-5,5-',6,6'-tetrachlor0-1,1'-diebhyl-3,3'-

disul foethylbenzimidnzolocarbocyani ne hydroxide Typical merocyanine dyes, which have general Formula H, that can be used in the light sensitive layer of the magenta dye-forming unit are:

Dye 354-[ (1-ethylnaphtho[1,'2-d] thlazolin-2-ylidene) -methyl-ethylidene] 3-methyl-1- (4-su1fopheny1) -2-pynazolin-5-oue) Dye 36-3etl1yl-5-[ (3-etl1yl2ebenzothiazolinyilidene) -1- methylethylidene] -2-two-12,4-oxazolldined'ione A preferred styryl dye base which can be employed in the emulsion layer or layers of the magenta dye-forming unit is:

Dye 452-(4-diethylaminostyry1)benzothiazole S C2H5 Advantageously, a combination of dyes is employed in the silver halide emulsion layer or layers of the magenta dye-forming unit. Preferred combinations of dyes in accordance with this invention are:

(1) Dye 21 plus Dye 22 plus Dye 35;

(2) Dye 2-2 plus Dye 25 plus Dye 35;

(3) Dye 24 plus Dye 25 plus Dye 35;

(4) Dye 23 plus Dye 25 plus Dye 35 (5) Dye 22 plus Dye 35 plus Dye 24; and

(6) Dye 22 plus Dye 25 plus Dye 35 plus Dye 23.

In the above combinations, Dye 35 can be replaced, if desired, by various other merocyanine dyes, such as Dye 36, or with a styryl dye base, such as Dye 45, to obtain generally similar sensitization.

The magenta dye-forming unit has a yellow colored (blue-absorbing) filter. This filter is preferably a layer between the yellow dye-forming unit and the silver halide emulsion of the magenta dye-forming unit. The yellow filter dye coacts with the silver halide emulsion of the magenta dye-forming unit, so that the emulsion of the magenta dye-forming unit has an effective response within the limits given in Table II, or within the area between curves FG-H and IG] of FIG. 2, when exposed by radiation of between about 475 to about 650 which first passes through the filter of the magenta dye-forming unit. The specific filter employed will, therefore, depend on the spectral sensitivity distribution of the silver halide emulsion employed. Particularly good results are obtained when the filter has an optical density to radiation up to about 535 nm. between curves U'V' and W'V' of FIG. 6, or has the following absorption characteristics:

TABLE V Absorption of filter in magenta dye-forming unit Radiation up to Filters in the magenta dye-forming unit which have a smooth, continuous curve (i.e., similar to curves U'V' 17 and WV' of FIG. 6) and which have the absorption characteristics shown in Table V at optical densities of .1, .2, .4, .8, 1.2 and 1.6, are useful herein.

A wide variety of yellow colored filters can be used in the magenta dye-forming unit, of the elements of this invention, e.g., silver dispersions such as Carey Lea silver or various filter dyes. An especially useful group of dyes has the following general formula:

R"'-1-'I-c=oH crr= (2:0

wherein R'" represents an alkyl group such as methyl, ethyl, n-propyl, n-butyl, isobutyl, B-sulfoethyl, 3-sulfobutyl, 4-sulfobutyl, etc., Z" represents the non-metallic atoms necessary to complete a benzoxazole nucleus (inclucling benzoxazole and benzoxazole substituted by simple substituents, such as methyl, ethyl, phenyl, methoxyl, ethoxyl, chlorine, bromine, etc.), and Q represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the pyrazolinone series, at least one of Q and R containing an acid substituted, e.g., sulfo or carboxy. The most useful dyes comprise those dyes containing at least two hydrocarbon radicals of groups which have been further substituted by a carboxyl or sulfo group. These yellow filter dyes are spontaneously removed during conventional color processing or they can be easily removed at any time simply by treatment with an aqueous alkaline solution. Certain of these dyes may actually be decolorized or bleached during processing, thus making complete removal thereof unnecessary, particularly in a negative process.

The structural formulas of some specific useful dyes having the above Formula A are shown below:

The formulas or names of still other useful yellow filter dyes are shown below:

(Quinone Yellow S) H C NHSO CH (5 O OH -COONa (Tartrazine) ONa (Uram'ne-Oolor Index 766) The red sensitive cyan dye-forming unit includes at least one light sensitive layer comprising silver halide grains which have a relative log spectral sensitivity response to radiation longer than approximately 603 nm. which meets the criteria in col. 3 of Table HI, or is at least as great as the response of curve L0 in FIG. 3. Such a response can be suitably imparted to silver halide grains by the use of spectral sensitizing dyes. Such dyes generally impart an excessively high response to green and blue radiation. A filter is employed in accordance With the invention, overlying the emulsion, which cooperates with the emulsion layer to adjust the response thereof to fall within the limits set out in Table III, or within the area defined between curves KLM and NLO of FIG. 3. It is one feature of this invention to provide sensitizing dye combinations which impart the correct spectral sensitivity for emulsions within the area defined between curves VLM and WLO of FIG. 3. These emulsions meet all the criteria in Table III except for too high a response to 19 radiation shorter than about 570 nm. at less than about 55% of maximum sensitivity. See col. 4 of Table III. Such emulsions require correction only for wavelengths shorter than about 570 nm. This correction brings the eflective response of the emulsion layer, to radiation between about 525 nm. and 725 nm. between curves KLM and NLO of FIG. 3, and within the limits specified in Table HI.

A variety of dye combinations can be employed in accordance with this invention to spectrally sensitize emulsions for use in the red sensitive layer. At least one sensitiizng dye is employed which imparts maximum sensitivity to radiation longer than approximately 603 nm., and at least one dye which imparts a relative log spec tral sensitivity response at least as great as curve L in FIG. 3 or to radiation longer than that shown in col. 3 of Table III. One highly useful class of sensitizing dyes has the following general formula: (m) Z1: 3:0 (|C=L) n1d\ ;Z4

wherein Z and Z, are selected from the values given for Z, Z and Z above; R and R are selected from the values given for R and R, above, R represents a hydrogen atom, lower alkyl group of from 1 to 4 carbon atoms such as methyl, ethyl, n-propyl, or iso-butyl or, taken together with 'R;,, an alkylene bridge of from 2 to 3 carbon atoms, such as an ethylene or propylene bridge; and, R represents a hydrogen atom or a lower alkyl group of from 1 to 4 carbon atoms, such as methyl, ethyl, iso-propyl or nbutyl, It, being alkyl when 2; and Z each, are selected from the group consisting of an oxazole, thiazole, or selenazole nucleus; n represents an integer of from 1 to 3 and is preferably 3; and, X represents an acid anion. Specific representative dyes of this class are set out below. Dyes in accordance with Formula HI above give excellent sensitization for the emulsions utilized in cyan dyeforming units in accordance with this invention. These dyes do not require separate addition when two or more dyes are employed, nor digestion of the emulsion between addition of the dyes. Carbocyanine dyes wherein at least one of Z, and Z, represents a halogen-substituted benzimidazole nucleus, such as a dichlorobenzimidazole nucleus, are especially useful.

Typical preferred dyes which can be used to sensitize the silver halide emulsion of the cyan dye-forming unit are listed below:

Dye 60Anhydro-5,6-dichloro 1 ethyl-3-(3-sulfobutyl-3 (3 sulfopropyl) 4',5' benzobenzimidazolothiacarbocyanine hydroxide Dye 61Anhydro-9-ethyl-3-methyl-5-phenyl-3'- 3-sulfobutyl oxaselenacarbocyanine hydroxide Dye 62-2- (4-diethylaminostyry1) benzothiazole 0-0 H=CH (1 G N\ Dye 63Anhydro-3,3'-di(fl-carboxyethyl)-5,5'-dlchlor0-9- ethylthiacarbocyanine hydroxide S S 2 I C=CHC=CHC N I I 9 CHzCHaGOOH HaCHzCOO Dye 649-ethyl-3,3'-dimethyl-4,5,4',5'-dibenzothiacarb0- cyanine chloride C=CHO=CH-C N I I OH; 0g 01 Dye 65Anhydro 5 s 3 sulfobutyls cyanine hydroxide 6 dichloro 3 ethyl 1 isopropyl- 4Z5 benzobenzimidazolothiacarbo- Dye 67Anhydro-5,5,6,6'-tetrachloro-1,1'-diethyl-3,3-disulfoethylbenzimidazolocarbocyauine hydroxide (llaHs 2 N N 01 c1 O-CH=CHCH=C 01 c1 60 f f (011M03 (CH:)SO:Na Dye 68-Anhydmo-9-ethyrh-3B'di (sulst'opropyl) -4,5,4',5' -dibenzothiacarbocyanine hydroxide, sodium salt C=CHC=CHC 7 C2115 e CHzCHzCHzSOaNa HzCHzCHzSO Dye 69Auhydro-5,6-dichloro-1,3-diethyl-5-methoxy-3'- (3- sulfoplropyl)benzzimidazo1oselena.carbocyanine hydroxide C=GH-CH=CHG O1 OCH; 70 ea 2H5 CHzCHzCHzSOa" All of the above dyes, except Dye 62, have above general Formula HI. Styryl dyes having above Formula la can be used in sensitizing the red sensitive layer. Advantageously, a combination of dyes is employed to impart the proper spectral distribution to the emulsion layer employed in the cyan dye-forming unit. Typical useful dye combinations are listed below:

(1) Dye 61 plus Dye 60 plus Dye 63 plus Dye 64;

(2) Dye 61 plus Dye 60 plus Dye 63 plus Dye 68;

(3) Dye 66 plus Dye 60 plus Dye 63 plus Dye 64;

(4) Dye 66 plus Dye 60 plus Dye 63 plus Dye 68;

(5) Dye 67 plus Dye 60 plus Dye 63 plus Dye 64;

(6) Dye 66 plus Dye 60 plus Dye 63 plus Dye 68;

(7) Dye 65 plus Dye 60 plus Dye 63 plus Dye 64;

(8) Dye 65 plus Dye 60 plus Dye 63 plus Dye 68; and, (9) Dye 61 plus Dye 69 plus Dye 63 plus Dye 64.

Still other dyes which can be used to sensitize the red sensitive emulsion layer of the cyan dye-forming unit are listed below:

1,8-ethylene-3-methylthiazolino-2'-carbocyanine iodide 5-{ (3 -ethyl-2-b enzothiazolinylidene) methyl] 1-ethyl- 4( 1H -pyridylidene methyl] methylene}- l-methyl- 2-thiobarbituric acid 1'-(3-dimethylaminopropyl)-1,3,3-trimethyl-4',6'-diphenylindo-2-pyridocarbocyanine iodide 1-(3-dimethylaminopropyl)-3-methyl-4,6-diphenyl-2- pyridothiazolinocarbocyanine iodide 1,1'-di(fl-hydroxyethyl)-3,3,3,3-tetramethylindocarbocyanine bromide Anhydro-9-ethyl-3',10-ethylene-5-phenyl-3-(3-sulfobutyl)-oxathiacarbocyanine hydroxide 3-benzyl-5-[ (3,4-trimethylene-2=benzothiazolinylidene ethylidene] rhodanine 3 '-ethyl-1,8-ethylene-3,3-dimethyl-4,5-benzo-indooxacarbocyanine iodide Anhydro-5,6-dichloro-l-ethyl-l,10-ethylene-3',3-dimethyl-3- (S-sulfobutyl) benzimidazolo-indocarbocyanine hydroxide 5-{ 1- (Z-diethylaminoethyl) -4,6-diphenyl-2 1H) -pyridylidene] -ethylidene}-3-ethylrhodanine Some of the dyes in the above list have general Formula III above; others are merocyanine dyes. These dyes can be used in various combinations, such as those listed above, to give similar spectral sensitization.

It will be noted that some dyes can be used in either the emulsion of the magenta dye-forming unit or the emulsion of the cyan dye-forming unit, to give proper spectral distribution to the emulsion thereof.

The cyan dye-forming unit has a magenta colored (green-absorbing) filter. This filter is preferably a layer between the magenta dye-forming unit and the silver halide emulsion of the cyan dye-forming unit. The magenta filter dye coacts with the silver halide emulsion of the cyan dye-forming unit so that the emulsion of the cyan dye-forming unit has an effective response within the limits given in Table III, or within the area between curves KLM and NLO of FIG. 3, when exposed by radiation between about 525 and 725 nm., which first passes through the filter of the magenta dye-forming unit. The specific magenta colored filter employed will, therefore, depend on the spectral sensitivity distribution of the silver halide emulsion employed. Particularly good results are obtained when the filter has an optical density to radiation up to about 610 nm. between curves XY and ZY of FIG. 7, or has the following absorption characteristics:

TABLE VI Absorption of filter in cyan dye-forming unit Radiation up to Optical density: wavelength, nm.

22 TABLE VIContinued Radiation up to Filters in the cyan dye-forming unit which have a smooth, continuous curve (i.e., similar to curves XY and ZY of FIG. 7) and which have the absorption characteristics shown in Table VI at optical densities of .1, .2, .4, .6, .8 and 1.0, are useful herein.

A wide variety of dyes can be employed in the filter of the cyan dye-forming units of the elements of this invention. Especially useful dyes are bis[3 methyl-l-(psulfophenyl) 2 pyrazolin-5-one(4)]trimethine oxonol; bis[l,3 di (5 carboxypentyl)-2-thiobarbituric acid (5)]trimethine oxonol; bis(Z-heXyl-Z-methyl-1,3-dioxane- 4,6 dione (5)pentamethine oxonol, potassium salt; trimethyl aurintricarboxylic acid, sodium salt (preferably mordanted as an aluminum lake); anhydro-5,5',6,6-tetrachloro l,l,diethyl-3,3'-disulfobutylbenzimidazolocarbocyanine hydroxide (preferably adsorbed to a fogged Lippman emulsion); 1,8-dihydroxy-2(6,8-disulfonaphthyl)-2- azo 3,6 disulfonaphthalene-sodium salt (4); 4-[4-(3- ethyl 2(3H) benzoxazolylidene) 2 butenylidene]-3- methyl-l-p-sulfophenyl 2 pyrazolin 5 one, monosulfonated; and, 3,3,3,3' tetramethyl 1,1 di(4-sulfobutyl)indocarbocyanine iodide.

The novel cyan, magenta and yellow dye forming units described herein are separately useful as photographic emulsion layers, as well as being useful in combination. For example, the cyan dye-forming unit hereof can be employed alone or with other magenta and yellow dye-forming units which do not necessarily conform to the sensitivity criteria for the magenta and yellow dye-forming units described above. In one highly useful embodiment of the invention, a cyan dye-forming unit of the type described herein, which may be sensitized, for example, with the combination of dyes described in Example 2, can have coated thereover, in the order given: a light-sensitive photographic silver halide emulsion layer containing a magenta dye-forming coupler and spectrally sensitized to green radiation with anhydro-S,5',6,6-tetrachloro-1,1',3- triethyl 3' (3 sulfobutyl)benzimidazolooarbocyanine hydroxide together with anhydro-5,5'-dichloro-9 ethyl- 3,3'-di(3-sulfopropyl)oxacarbocyanine hydroxide, sodium salt (which does not give the required spectral sensitivity distribution to meet the criteria set out above for magenta dye-forming units of the invention) together with a yellow filter layer thereotver, such as the yellow filter layer of layer 6 in Example 1 below; and, a photographic silver halide emulsion layer sensitive to blue radiation and containing a yellow dye-forming coupler. Elements of the type just described are particularly useful when balenced to give a neutral when exposed to tungsten or fluorescent radiation, and employed in a camera adapted to optionally employ over the lens a suitable ultraviolet filter which also a bsorbs some blue radiation, such as a Kodak Wratten No. Filter (described in Kodak Wratten Filters for Scientific and Technical Use, 2nd edition, published in 1966 by the Eastman Kodak Company, page 57). Advantageously the filter is adapted (for automatic or manual placement over the camera lens when exposure is made under daylight illumination. Preferably, the filter is moved to an inoperable position when exposure is made under tungsten or fluorescent illumination.

The silver color forming units described above are arranged on a support with the magenta dye-forming unit intermediate the yellow dye-forming unit and the cyan dye-forming unit. The layers of the photographic element are arranged so that when exposed, radiation passes through, in the order given, the filter for the yellow dyeforming unit; the blue sensitive silver halide emulsion;

the filter in the magenta dye-forming unit; the green sensitive emulsion; the filter of the cya.n dye-forming unit; and, the red sensitive emulsion. When a transparent support is used, either the yellow dye-forming unit or the cyan'dyeforming unit can be coated adiacent the support. Using a transparent support with the yellow dye-forming unit closest to the support, the element can be exposed through the support. When opaque supports are employed, the red sensitive cyan dye-forming unit is advantageously placed closest the support, with the magenta dye-forming unit and the yellow dye-forming units, respectively, placed thereover in the manner shown in FIG. 4.

In order to extend the exposure latitude of the film, each dye-forming unit can contain more than one silver halide emulsion layer. For example, each unit can contain a fast and a slow emulsion layer. Other means known in the art for extending the latitude of multicolor films, such as employing mixed grain emulsions, can also be employed.

As indicated above, dyes can be used in the filters of the dye-forming units. -It is sometimes desirable to mordant the dye, especially when the dye used tends to migrate from the layer. When a basic dye is employed, an acidic mordant can be used. However, preferred dyes used herein are acidic dyes (i.e., they contain one or more acidic groups, such as carboxyl or sulfo acid groups, in free acid form or salt form). Such dyes can be mordanted with a basic mordant.

The most useful mordants are, therefore, basic in character and have a molecular weight of at least 250. These mordants are readily dispersible in water, or water containing an ionic dispersing agent. Particularly useful mordants comprise those having molecular weight of at least 250, at least one tertiary or quaternary nitrogen atom, and sufiicient hydrophilic properties to enable these mordants to be dispersed readily in water. The most useful mordants comprise those derived from a linear polymer or interpolymer. Representative of such polymers are mordants obtained from a monoethylinically-unsaturated, polymerizable compound containing a di alkylamino group, or polymerized, monoethylenically-unsaturated compounds which have been modified to contain a dialkylamino group.

Typical mordants which can be used are piperidyl cellulose, chloromethylated polystyrene which has been solubilized by treatment with pyridine (see U.S. Pat. 2,694,702), dial-kylaminoalkyl esters or dialkylamino alkylamino amides (e.g., such as those described in Carroll et a1. U.S. Pat. 2,675,316, issued Apr. 13, 1954), reaction products or canbonyl containing polymers and aminoguanidine or their salts (e.g., those derived by reacting polyvinyl alkyl ketones or aldehydes, such as polyacrolein, polyvinyl methyl ketone, etc., with aminoguanidine, as described in L. M. Minsk, U.S. 2,882,156, granted Apr. 14, 1959, or polymers obtained by reacting a dialkyllaminoalkyl amine with a polymer of maleic anhydride or a derivative of maleic anhydride. Other mordants which can be used comprise those described in Fowler et al., U.S. Pat. 2,721,852, issued Oct. 25, 1955, and Fowler et al. U.S. Pat. 2,798,063, issued July 2, 1957. Non-polymeric high molecular weight mordants which can be used comprise long-chain alkyl quaternary ammonium compounds, such as decamethylene-bis-trimethylammonium bromide, n-octyl tri-fi-hydroxyethylammonium chloride, n-dodecyl diethyl-B-hydroxyethylammonium chloride, etc. (e.g., tetraalkylammonium halides containing an alkyl group having at least 8 carbon atoms). Particularly useful mordants comprise those derived from maleic anhydride, or a derivative thereof and those of Minsk U.S. Pat. 2,882,156, referred to above.

Photographic elements comprising the dye-forming units of the invention can be employed in any subtractive photographic color process where white is produced by the absence of colored materials; black is produced by the combined absorptions of all colored materials; and, the

colored materials produced comprise yellow, magenta and cyan colored dyes. Such dyes can be formed in any convenient manner, Such as by the photographic process referred to below. The relative speeds of the emulsions employed in the dye-forming unit are adjusted in any suitable manner, so that neutrals will be reproduced accurately. Generally, highly useful results are obtained when the relative speed of the emulsion layers of the magenta and cyan dye-forming units are about the same, and the emulsion of the yellow dye-forming unit is somewhat faster, preferably at least about 50% faster, such as from about 75% to about faster than the speed of the emulsions in the other dye-forming units. The speed of the' emulsions in the yellow dye-forming unit can be much faster than the speed of the other units, since suitable speed correction can be made with a yellow filter without changing the speed of the other emulsions.

The elements of this invention give good neutrals upon exposure to subjects illuminated by daylight, tungsten or fluorescent sources. This is to be contrasted with prior art reversal color films, some of which are balanced to give a neutral upon exposure to daylight, and others being balanced to give neutrals upon exposure to tungsten illumination. Serious defects in color balance and rendition of neutrals are apparent when a film balanced for one source is exposed to a different source. Thus, pictures obtained with prior art reversal subtractive color films balanced to give a neutral under daylight exposure conditions, appear yellowish when exposure is made with a tungsten source, and to green when a fluorescent source is used. If the film is balanced to give neutrals when a tungsten source is used, pictures obtained when the film is exposed under daylight conditions will be too blue; and the pictures will appear greenish-blue when fluorescent illumination is utilized.

In a preferred embodiment of the invention, the photo graphic elements are utilized in a subtractive multicolor photographic system wherein the emulsion layers of the dye-forming units contain, or have contiguous to the silver halide thereof, color-formers or couplers. As used herein, the term color-former includes any compound which reacts (or couples) with the oxidation products of primary aromatic amino developing agent on photographic development to form a dye, and are non-diifusible in a hydrophilic binder (e.g., gelatin) useful for photographic silver halide. Typical useful color-formers include phenolic, 5-pyrazolone, heterocyclic and open-chain ketomethylene compounds. Specific cyan, magenta and yellow color-formers which can be used, respectively, in the cyan, magenta and yellow dye-forming units of the invention are described in Graham et al., U.S. Pat. 3,046,129, issued July 24, 1962, column 15, line 45 through column 18, line 51, which disclosure is incorporated herein by reference. Such color formers can be dispersed in the emulsion layers in any convenient manner, such as by using the solvents and the techniques described in U.S. Pats. 2,322,027 or 2,801,171. The useful couplers include Fischer-type incorporated couplers such as those disclosed in Fischer, U.S. Pat. 1,055,155, and particularly non-dilfusiblie Fischertype couplers containing branched carbon chains, e.g., those referred to in the references cited in Frohlich et al., U.S. Pat. 2,376,679, col. 2, lines 56-60. These elements can be processed by one of the procedures described in Graham et al., U.S. Pat. 3,046,129, cols. 23 and 24.

The photographic elements of this invention are also highly useful in subtractive multicolor photographic processes wherein color-former is introduced into the silver halide emulsion layers during development. Processes of this type are described in the literature, such as Mannes et al., U.S. Pat. 2,252,718, issued Aug. 19, 1941. Typical useful color-formers which can be used in such processes include the aqueous alkali soluble pyrazolone, phenolic and open-chain ketomethylene couplers which combine with the reaction products of color developing agents, such as p-phenylenediamine, to form magenta, cyan and yellow dyes. Specific color-formers which can be used include 25 those cited in McCarthy, U.S. Pat. 3,165,407, issued Jan. 12, 1965, at col. 2, line 20 through col. 3, line 47; Fierke et al., U.S. Pat. 2,801,171, issued July 30, 1957; and, 'McCrossen et al., U.S. Pat. 2,875,057, issued Feb. 24, 1959, the disclosures of which is incorporated herein by reference.

In color systems of the type described above, substractive dye images can be generated by a color negative process, such as the process described by W. T. Hanson and W. I. Kesner in an article in the Journal of the Society of Motion Picture and Television Engineers, vol. 61 (1953) pages 667701; or, by a color reversal process wherein reversal silver images are generated in any convenient manner, such as by using a direct positive emulsion or using a negative emulsion which is given an image-wise exposure, developed in a black-and-white developer to provide a negative silver image, and then at least one additional exposure (or other suitable fogging treatment) followed by additional development to generate the desired substractively colored dye images.

The color-forming developers which can be used in accordance with the two processes described above have been previously described in the art. The mo t useful of such color-forming developers are the phenylene diamines and substituted derivatives thereof, such as those disclosed in Weissberger et al., U .8. Pat. 2,548,574 issued Apr. 10, 1951; Weissberger et al., U.S. Pat. 2,552,240-2, issued May 8, 1951; and, Weissberger et al., U.S. Pat. 2,566,271, issued Aug. 28, 1951. Other phenylene diamine colorforming developers can be employed to advantage in the process of this invention.

This invention is also applicable to other photographic processes for forming multicolor images, such as color diffusion transfer processes of the type described in Rogers U.S. Pat. 2,983,606, issued May 9, 1961; Weyerts U.S. Pat. 3,146,102; issued Aug. 25, 1964; Rogers U.S. Pat. 3,087,817, issued Apr. 30, 1963; Barr et 'al. U.S. Pat. 3,227,551, issued Jan. 4, 1966; Barr et a1. U.S. Pat. 3,227,- 554, issued Jan. 4, 1966; Barr. U.S. Pat. 3,243,294, issued Mar. 29, 1966; Whitmore et al. U.S. Pat. 2,337,550, issued Jan. 4, 1966; Yutzy U.S. Pat. 2,756,142, issued July 24, 1956; Whitmore U.S. lPat. 3,227,552, issued Aug. 27, 1964; and, Land U.S. Pats. 3,415,664, 3,415,645 and 3,- 415,646, all issued Dec. 10, 1968.

The novel addenda of this invention can also be employed to advantage in photographic elements which are useful in providing dye images by the photographic silver dye bleach process. In such Processes, which are described in the literature, bleachable dye is incorporated in or contiguous to a given silver halide layer, a silver image is produced after exposure, and the dye is bleached imagewise in proportion to the silver image developed to provide contrasting dye images.

When photographic elements of the invention are utilized in any of the multi-color photographic processes and systems referred to above, good color rendition is obtained whether exposure is to daylight, tungsten or fluorescent illumination.

Advantageously, the dye formers utilized are selected so that they will give a good neutral. Preferably, the cyan dye formed has its major absorption between about 600 and 680 nm.; the magenta dye has its major absorption between about 500 and 580 nm; and the yellow dye has its major absorption between about 400 and 480 nm.

The light sensitive layers of the dye-forming units of the invention can comprise any suitable light sensitive silver halide, including silver bromide, silver iodide, silver chloride, or mixed silver halides, such as silver chlorobromide, silver bromoiodide or silver chlorobromoiodide.

The light sensitive silver halide emulsions employed in the dye-forming units of this invention can contain various chemical sensitizers, optical sensitizers, stabilizers, speed increasing compounds, plasticizers, hardeners and coating aids, such as are described and referred to in Beavers U.S. Pat. 3,039,873, issued June 19, 1962, cols.

9-12. The light sensitive silver halide salts can be dispersed in various binders, such as the colloids described and referred to in aforementioned Beavers patent, col. 13 or those disclosed in U.S. Pats. 3,142,568; 3,193,386; 3,062,- 674; and 3,220,844, including the water insoluble polymers of alkyl acrylates and methacrylates, acrylic acid, sulfoalkyl acrylates or methacrylates, and the like. Any suitable support can be used, such as a cellulose ester, poly(ethylene terephthalate), paper, baryta coated paper, polyolefin coated paper such as polyethylene or polypropylene coated paper, which can be electron bombarded to promote emulsion adhesion. Emulsion layers having difierent speeds can be utilized to extend the latitude of the element.

The following examples are included for a further understanding of the invention. Example 1 shows a photographic element having coated thereon the three dyeforming units of the invention.

EXAMPLE 1 A photographic element is prepared by coating cyan, magenta and yellow dye-forming units in accordance with the invention on a cellulose acetate film support carrying an antihalation coating thereon of gelatin (455 mg. per square foot) containing gray colloidal silver (23 mg. per square foot). The dye-forming units, described below are coated, in the order given, over the antihalation coating:

CYAN DYE-FORMING UNIT Layer 1Slow, red sensitive Gelatin silver bromoiodide (6 mole percent iodide) emulsion is coated at 97.9 mg. per square foot gelatin, 68.2 mg. per square foot silver and contains 40.9 mg. per square foot of a dispersion of a cyan forming coupler, coupler No. 4 of Fierke et al. U.S. Pat. 2,801,171 (col. 2) in conventional coupler solvent such as tri-o-cresyl phosphate. Spectral sensitivity is provided by mg. Dye 61; 270 mg. Dye 60; 45 mg. Dye 63 and 30 mg. Dye 64, all dye concentrations being per mole of silver. The relative speed of the emulsion is 50.

Layer 2--Fast, red sensitive This layer has essentially the same composition as layer 1 except that the relative speed of the emulsion is 100, the gelatin coverage is at the rate of 89.6 mg. per square foot; the silver coverage is at 68.2 mg. per square foot; the coupler coverage is at 66.7 mg. per square foot; and, spectral sensitivity is provided by 144 mg. Dye 61, 216 mg. Dye 60; 36 mg. Dye 63 and 24 mg. Dye 64, all dye concentrations being per mole of silver.

Layer 3--Magenta colored filter A filter layer is coated at the rate of 60 mg. gelatin per square foot and 8 mg. per square foot of the dye, bis[3- methyl-l-(p-sulfophenyl)-2 pyrazolin-S one) (4)]trimethine oxonol, premordanted with 8 mg. per square foot of poly-u-methyl-allyl-Naguanidyl-keti'mine glycollate.

MAGENTA DYE-FORMING UNIT Layer 4-Slow, green sensitive A gelatin silver bromoiodide (6 mole percent iodide) emulsion is coated at the rate of 119 mg. per square foot gelatin, 77.7 mg. per square foot silver and contains 49.9 mg. per square foot of a pyrazolone coupler, coupler No. 7 of Fierke et a1. U.S. Pat. 2,801,171 (col. 2) in tri-ocresyl phosphate. Spectral sensitivity is provided by 356 mg. dye 25, 71.5 mg. Dye 35 and 178.2 mg. Dye 26, all dye concentrations being per mole of silver. The relative speed of the emulsion is 50.

Layer 5Fast green sensitive This layer has essentially the same composition as layer 4 except that the silver coverage is at the rate of 93.3 mg. per square foot; the coupler concentration is 66.9 mg. per square foot; the gelatin concentration is 103.6 mg. per square foot; and the concentration of sensitizing dyes,

per mole of silver, is 286 mg. Dye 25, 57.2 mg. Dye 35 and 143 mg. Dye 26. The relative speed of this layer is 100.

Layer 6Yellow filter layer A gelatin layer is coated at the rate of 91 mg. per square foot and contains 18 mg. per square foot of 4-[(3- ethyl-2( 3H) benzoxazolylidene)ethylidene]-3-methyl-1- p-sulfophenyl-Z-pyrazolin-5-one, monosulfonated and 18 mg. per square foot of poly-a-methyl-allyl-N-guanidylketimine glycollate as mordant.

YELLOW DYE-EORMING UNIT Layer 7 A gelatin silver bromoiodide (6 mole percent iodide) emulsion is coated at the rate of 82 mg. per square foot gelatin, 45 mg. per square foot silver and contains 66 mg. per square foot of a yellow image-forming coupler, coupler No. III of McCrossen et al. US. Pat. 2,875,057, issued Feb. 24, 1959, dispersed in dibutyl phthalate. The layer has a relative speed of 125 and contains no spectral sensitizing dye.

layer 8Fast blue sensitive This layer has the same composition as layer 7 except that the gelatin is coated at the rate of 145 mg. per square foot, the silver coverage is 82.5 mg. per square foot and the concentration of coupler is 133 mg. per square foot. The relative speed of this layer is 175.

Layer 9Ye1low and ultraviolet filter layer A gelatin layer is coated at a coverage of 91 mg. per square foot and contains as ultraviolet absorber and blue trimming dye 55 mg. per square foot of 2-[(3-cyano-3- dodecylsulfonyl)allylidene] 3 (3-sulfopropyl)thiazolidene, potassium salt, mordanted with 55 mg. per square foot poly-a-methyl-allyl-N-guanidyl ketimine glycolate.

When the photographic element prepared as described above is sensitometrically exposed to white light and developed as described below, it is found that the response of the yellow dye forming unit falls within the curves ABC and DBE of 'FIG. 1; the response of the magenta dye-forming unit falls within the area defined between curves FGH and 16] of FIG. 2; and, the response of the cyan dye forming unit falls within the areas defined between curves KLM and NLO of FIG. 3. Separate samples of the film are tested sensitometrically by exposure to color charts illuminated with tungsten, fluorescent and daylight illumination: Good neutrals and acceptable color rendition is obtained with each sample. Similar results are obtained when layer 9 of the above-identified element is replaced with a clear gelatin layer as a protective overcoat, and the exposure is made through a yellow and ultraviolet filter layer comprising a glass support having coated thereon a layer having the same composition as layer 9 above.

In Example 1 and the following examples, the elements are developed in the following reversal color process: first, the exposed film is developed in a developer having the following composition:

Sodium hexametaphosphate g 2.0 N-methyl-p-aminophenol sulfate g 6.0 Sodium sulfite, anhydrous g 50.0 Hydroquinone g 6.0 Sodium carbonate monohydrate g 35.0 Potassium bromide g 2.0 Sodium thiocyanate g 1.5 0.5% solution of 6-nitrobenzimidazole nitrate cc 12.

0.1% solution of potassium iodide cc 10.0

Water to make 1 liter.

The element is then thoroughly washed with water and treated in a hardening bath having the following composition:

Potassium chrome alum crystals g 30.0 Water to make 1 liter.

The element is then thoroughly washed with water and treated for 30 seconds in a solution having the following composition:

. G. Sodium borohydride 0.25 Sodium hydroxide 4.0

Water to make 1 liter.

The element is then treated in a color developer having the following composition:

Water to make 1 liter.

4 amino-N-ethyl-N-(fi-methanesulfonamldoethyl)-m-toluidine sesquisnlfate monohydrate.

The element is then thoroughly washed with water and treated in a clearing and fixing bath having the following composition:

G. Sodium thiosulfate 150.0 Sodium bisulfite 20.0

Water to make 1 liter.

The element was then treated in a bleach bath having the following composition:

G. Potassium dichromate 5.0 Potassium ferricyanide 70.0 Potassium bromide 20.0

Water to make 1 liter.

The element is again washed and treated once again with the clearing and fixing bath identified above. The element is again washed and treated in a stabilizing bath having the following composition:

Formaldehyde (37% by weight) cc 7.0

Dispersing agent (octylphenoxy polyethoxy ethanol) E 0.5

Water to make 1 liter.

Examples 2-7 show various combinations of spectral sensitizing dyes which can be used in the red sensitive silver halide emulsion layers employed in the cyan dye forming units of the invention.

EXAMPLE 2.

A photographic element is prepared exactly as described in Example 1 except the emulsions of layers 1 and 2 are spectrally sensitized with the combination of 72 mg. Dye 61; 108 mg. Dye 60; 18 mg. Dye 63 and 24 mg. Dye 68, all concentrations being per mole of silver.

EXAMPLE 3 A photographic element is prepared exactly as described in Example 1 except the emulsions of layers 1 and 2 are spectrally sensitized with 72 mg. Dye 66; 108 mg. Dye 60; 18 mg. Dye 63 and 24 mg. Dye 68, all concentrations being per mole of silver.

EXAMPLE 4 A photographic element is prepared exactly as described in Example 1 except that the red sensitive emulsions in layers 1 and 2 are spectrally sensitized with 72 mg. Dye 67; 108 mg. Dye 60; 18 mg. Dye 63 and 24 mg. Dye 64, all concentrations being per mole of silver.

Images