US3575704A

US3575704A - High contrast light sensitive materials

Info

Publication number: US3575704A
Application number: US743333A
Authority: US
Inventors: Eugene D Salesin
Original assignee: Eastman Kodak Co
Current assignee: Eastman Kodak Co
Priority date: 1968-07-09
Filing date: 1968-07-09
Publication date: 1971-04-20
Anticipated expiration: 1988-04-20
Also published as: GB1267587A; FR2012581A1

Abstract

PHOTOGRAPHIC ELEMENTS COMPRISING A SUPPORT COATED WITH A HYDROPHILIC LAYER CONTAINING A FINE GRAIN, HIGH CONTRAST SILVER HALIDE EMULSION THAT IS ORTHOCHROMATICALLY SENSITIZED WITH A DECOLORIZABLE SPECTRAL SENSITIZING DYE THAT PRODUCES A MODICUM OF SENSITIVITY IN THE RED REGION OF THE SPECTRUM, SAID ELEMENTS HAVING POOR TOLERANCE TO RED SAFELIGHT ARE MADE TOLERANT TO RED SAFELIGHT BY INCORPORATING IN THE HYDROPHILIC COLLOID LAYER WITH OR ABOVE THE SILVER HALIDE, A WATER-SOLUBLE ANTHRAQUINONE DYE WHICH HAS SUBSTANTIALLY NO ABSORPTION OF LIGHT IN THE BLUE AND GREEN REGIONS OF THE SPECTRUM BUT STRONGLY ABSORBS LIGHT IN THE RED REGION OF THE SPECTRUM, WITHOUT ADVERSELY AFFECTING THE QUALITY OFTHE DEVELOPED, HIGH CONTRAST IMAGES OR LEAVING ANY APPRECIABLE STAIN IN THE PROCESSED ELEMENT.

Description

United States Patent 9 US. Cl. 96-94 16 Claims ABSTRACT OF THE DISCLOSURE Photographic elements comprising a support coated with a hydrophilic colloid layer containing a fine grain, high contrast silver halide emulsion that is orthochromatically sensitized with a decolorizable spectral sensitizing dye that produces a modicum of sensitivity in the red region of the spectrum, said elements having poor tolerance to red safelight are made tolerant to red safelight by incorporating in the hydrophilic colloid layer with or above the silver halide, a watersoluble anthraquinone dye which has substantially no absorption of light in the blue and green regions of the spectrum but strongly absorbs light in the red region of the spectrum, without adversely affecting the quality of the developed, high contrast images or leaving any appreciable stain in the processed element.

This invention relates to improved photographic elements and includes photographic elements containing ortho-sensitized high contrast silver halide emulsions having improved safelight tolerance.

Photographic films used in the graphic arts for making half-tone or line images should be capable of producing extremely high contrast and good image sharpness. These factors contribute in the case of half-tone images to high quality, that is, to the production of half-tone dots of high density and sharpness. Photographic elements of the lith-type, that is, elements having a fine grain high contrast silver halide emulsion containing at least 60 mole percent chloride, less than 40 mole percent bromide and less than about 5 mole percent iodide are especially efficacious for use in the graphic arts where high dot quality is required. These elements usually require the use of pure hydroquinone developer solutions having very low sulfite ion concentration in the alkaline solution in order to produce the high contrast and high dot quality required for good quality half-tone reproduction. The known photographic films used in the graphic arts usually are relatively slow in speed and require relatively long exposure even when very high intensity light sources are used. It is, therefore, desired to spectrally sensitize these photographic emulsions so that the green light in the light source as well as the blue light will be recorded. Spectral sensitizing dyes which have been tried in these emulsions for ortho-sensitizing them have left undesirable stains in the processed element. Other spectral sensitizing dyes which have left relatively little, if any, stain in the processed elements have produced an undesirable sensitivity in the red region of the spectrum. This has produced problems because it has always been the practice of those using graphic arts photographic materials to develop the exposed film under enough red light so that the quality of the developing image could be observed and the length of development controlled to give optimum quality. The undesirable red light sensitivity produced by available green light-sensitizing dyes which produce little, if any, stain in the processed photographic materials has made it impractical to use red safelights to follow the develop ment as has been the practice. Improved photographic elements are therefore desired for use in the graphic arts which are ortho-sensitized and which can be processed under red safelights.

It is an object of my invention to provide improved high contrast fine grain photographic silver halide emulsions which are ortho-sensitized but have improved safelight tolerance.

It is another object of my invention to provide improved photographic elements for use in the graphic arts to produce extremely high contrast images and good image sharpness with little, if any, stain in the processed element, the said emulsion being ortho-sensitized and capable of being handled and developed safely under conventional red safelights used in the graphic arts.

Still other objects Will become apparent from the following specification and claims.

These and other objects are accomplished according to my invention by providing photographic elements containing my ortho-sensitized high contrast fine grain silver halide emulsion in which the silver halide containing at least about 60 mole percent chloride, less than about 40 mole percent bromide and less than about 5 mole percent iodide which has a modicum of sensitivity in the red region of the spectrum, and a Water-soluble anthraquinone dye which has substantially no absorption of light in the blue and green regions of the spectrum but which strongly absorbs light in the red region of the spectrum and which produces substantially no change in quality of high contrast images produced by development of latent images in my silver halide emulsions. By modicum of sensitivity in the red region of the spectrum, I mean a minor amount of sensitivity which will produce an undesirable amount of fog in a high contrast fine grain silver halide emulsion from prolonged exposure to a red safelight followed by the usual photographic development. The anthraquinone dye is advantageously incorporated in the photographic emulsion layer since it has substantially no sensitizing effect on the silver halide emulsion or alternatively it is advantageously coated in a layer over the silver halide emulsion layer or even under the silver halide emulsion layer since the anthraquinone dye is water-soluble and diffuses readily from one layer to the next layer.

My photographic elements have good tolerance to exposure to red safelights and the processed element contains little, if any, residual stain from the spectral sensitizing dye and substantially no stain from the anthraquinone dye. Any of the conventional processes can be used to advantage for processing my photographic elements.

The fine grain silver halide emulsions used to advantage are high contrast emulsions which when developed in high contrast developers, such as, an amine developer in a roller transport system as described in Belgian Patent 704,595, produce a contrast in the range from about 2 to about 20 measured at a density of 0.10 above gross fog over a range of 0.40 log E with a gradient meter. The emulsions have silver halide crystals, preferably containing at least about 60 mole percent chloride, less than about 40 mole percent bromide and less than about 5 mole percent iodide. A preferred emulsion contains at least about percent chloride in the silver halide. The emulsions are advantageously prepared as described by MacWilliam US. Patent 2,756,148, issued July 24, 1956.

The silver halide is dispersed in hydrophilic colloid materials used as binders, including gelatin, colloidion, gum arabic, cellulose ester derivatives, such as, alkyl esters of carboxylated cellulose, hydroxy ethyl cellulose, carboxy methyl cellulose, hydroxy ethyl cellulose, synthetic resins, such as the amphoteric copolymers described by Clavier et al. in US. Patent 2,949,442, issued Aug. 16, 1960, polyvinyl alcohol, and others well known in the art. Examples of these polymeric gelatin substitutes are copolymers of allylamine and methacrylic acid; copolymers of allylamine, acrylic acid and acrylamide; hydrolyzed copolymers of allylamine, methacrylic acid and vinyl acetate;

the copolymers of allylamine, acrylic acid and styrene; the copolymers of allylamine, methacrylic acid and acrylonitrile; alkyl acrylate-acrylic acid copolymers, e.g., cpolymers of butyl acrylate-acrylic acid, etc.

It is advantageous to add certain onium salts, such as, quaternary ammonium salts, sulfonium salts and phosphonium salts to my light-sensitive emulsions in order to increase the photographic speed without adversely affecting the dot quality, contrast and evenness of development. Examples of quaternary ammonium salts include nonyl pyridinium perchlorate, hexoxymethyl pyridinium perchlorate, ethylene bis-dioxymethyl pyridinium perchlorate and others described by Carroll U.S. Patent 2,271,- 623, issued February 3, 1942, hexadecamethylene-1,16- bis(pyridinium perchlorate), 9,16-diaza-7,18-dioxa-8,17- dioxotetracosane-1,2,4-bis(pyridinium perchlorate), and others of Beavers et a1. U.S. Patent 2,944,898, issued July 12, 1960. Other examples include the onium salts of polyoxyalkylenes of Carroll et al. U.S. Patent 2,944,- 902, issued July 12, 1960, the polyonium salts of Carroll et al. U.S. Patent 2,288,226, issued June 30, 1942, such as bis(lauryl methyl sulfonium p-toluene sulfonate) l,2 ethane, N,N'-trimethylene dioxymethyl pyridinium perchlorate, etc., the sulfonium salts of Carroll et a1. U.S. 2,275,727, issued Mar. 10, 1942, such as, n-decyl dimethyl sulfonium p-toluene sulfonate, n-nonyl dimethyl sulfonium p-toluene sulfonate, etc., and the phosphonium salts of Carroll et a1. U.S. Patent 2,271,622, issued Feb. 3, 1942, such as, tetramethylene bis-triethyl phosphonium bromide, lauryltriethyl phosphonium bromide, etc.

My light-sensitive emulsions are advantageously coated chemically sensitized with compounds of the sulfur group, e.g., sulfur compounds of Sheppard U.S. Patent 1,574,944, and Sheppard et a1. U.S. Patents 1,623,499 and 2,410,689, selenium compounds of Dunn U.S. Patent 3,297,446, and McVeigh U.S. Patent 3,297,447 and tellurium compounds of Canadian patent application 933,538, filed June 17, 1965, and chemically sensitized with gold compounds of Waller et al. U.S. Patent 2,399,083. My silver halide emulsions advantageously contain water-soluble block polymers of polyoxypropylene and polyoxyethylene of Goffe U.S. Patent 3,294,540 and silicon-containing polymers of Milton U.S. Patent 3,294,537.

My light-sensitive emulsions are advantageously coated on any of the conventional photographic supports including glass, cellulose acetate, polystyrene, polyalkylene terephthalate, etc.

My emulsions are advantageously orthochromatically sensitized by using a spectral sensitizing dye which spectrally sensitizes in the green region of the spectrum and produces a modicum of sensitivity in the red region of the spectrum. My orthochromatic spectral sensitizers leave little, if any, stain after processing. The preferred dyes are substantially completely decolorized during photographic processing. By decolorizing I mean that the dye is either converted to an uncolored form by hydroxyl ions, sulfite ions, etc., in the processing solutions or that the dye is actually washed out of the photographic emulsion during processing. In some instances, the decolorizing may involve both the formation of an uncolored dye and removal of the dye or uncolored dye. Included among the spectral sensitizing dyes used to advantage are: cyanine dyes (e.g., cyanine dyes and complex cyanine dyes having more than two heterocyclic nuclei) in which the conventional to 6-membered basic heterocyclic nuclei are used including thiazoles, benzothiazoles, naphthothia- Zoles, oxazoles, benzoxazoles, naphthox-azoles, imidazoles, benzimidazoles, naphthimidazoles, quinoline, etc., which are unsubstituted or are advantageously substituted with any of the conventional substituents used on cyanine dyes including lower alkyl groups preferably having from 1 to 4 carbon atoms, carboxyalkyl groups; sulfoalkyl groups, hydroxyalkyl groups, all of which preferably have from 1 to 4 carbon atoms, halogens, etc.; merocyanine dyes in which the basic nuclei are substituted or unsubstituted and are any of the above mentioned 5- to 6-membered basic heterocyclic nuclei including in addition pyridines, indoles, tetrazoles, etc. and in which the acidic nucleus is 1,3-cyclohexanedi0ne, or any of the conventional 5- to G-membered acidic heterocyclic nuclei including thiohydantoins, hydantoins, rhodanines, thiazolin-4-ones, 2-thio- 2,4-oxazolidinediones, 5-pyrazolones, barbituric acids, thiobarbituric acids, imidazoles, etc. that are unsubstituted or have substituents such as alkyl having from I to 8 carbon atoms, carboxyalkyl of from 1 to 8 carbon atoms, sulfoalkyl of from 1 to 8 carbon atoms, phenyl, sulfo phenyl, carboxyphenyl, hydroxyphenyl, carboxy, amino, dialkylaminoalkyl in which the alkyl groups have from 1 to 3 carbon atoms, etc.; holopolar dyes in which the two basic nuclei are any of those described above and the meso substituent is any of the acidic nuclei described including 3,5-pyrazolidinediones, and dicyanomethyl, etc.; and oxonol dyes in which the acidic nuclei are any of those described herein previously and in addition include 3(2H)thianaphthenone-l,l-dioxides, and 6-oxo-5,6-dihydroimidazo[2,1-b1thiazoles, etc.

Preferred representative orthochromatic sensitizing dyes used to advantage according to my invention include the following:

(I) anhydro-5,6-dichloro-1,3'-diethy1-3-(3-sulfopropyl) benzimidazolooxacarbocyanine hydroxide (II) 1,3-diethyl-6'-methyl-4,5-benzothia-2-cyanine bromide (HI) anhydro-S,5',6,6'-tetrachloro-l,l'-diethyl-3,3'-

di(3-sulfobutyl)benzimidazolocarbocyanine hydroxide (IV) 3,3-diethyl-9-methyl-4,5-benzoxathiacarbocyanine iodide (V) anhydro-S-chloro-l,3'-diethyl-3-(3-sulfobutyl) benzimidazolothiacarbocyanine hydroxide (VI) 1-ethyl-1'-(B-hydroxypropyl)-2,2-cyanine iodide (VII) anhydro-9-ethyl-5,5'-diphenyl-3,3-di(3-sulfobutyl)oxacarbocyanine hydroxide monosodium salt (VIII) 5-(5,6-dichloro-l,3-diethyl-2-benzimidazolinylidene) -3-ethyl-2-[ (3-ethyl-2-benzothiazolinylidene) methyl]-4-oxo-2-thiazolininm-p-toluenesulfonate (IX) 3 -carboxymethyl-1,5-[(3-methy1-2-thiazolidinylidene)isopropylidene1rhodanine (X) 5 3-ethylnaphth [2,1-a] oxazolin-2-ylidene) ethylidene] -3-N-heptyl-1-phenyl-2-thiohydantoin (XI) 5-[(3-ethyl-2-benzoxazolinylidene)ethylidene]- 3-heptyl-1-phenyl-2-thiohydantoin (XII) 3-ethyl-5-{ 3- (4-sulfobutyl) -2-thiazolidinylidene]ethylidene}rhodanine, potassium salt (XIII) 3-carboxymethyl-5-{ 3-ethyl-4-(paramethoxyphenyl -5-phenyl-2- 4-oxazolinylidene) Jethylidene} rhodanine (XIV) Z-diphenylamino- (3 -ethyl-2-benzothiazolinylidene)ethylidene] -2-thiazolin-4-one (XV) 3-ethyl[ (3-ethyl-2-benzothiazolinylidene) isopropylidene]-2tl1io-2,4-oxazolidinedione (XVI) 5-[(3-ethyl-2-benzoxazolinylidene)ethylidene]- 3-heptyl-2-thio-2,4-oxazolidinedione (XVII) 3-methyl-1-(p-sulfophenyl)-4-[ 1,3,3-trimethyl- 2-indolinylidene ethylidene] -5-pyrazolone (XVIII) 4- 3-ethyl-2-benzothiazolinylidene) isopropylidene] -3-rnethyll- (p-sulfophenyl -5-pyrazolone (XIX) 3-carboxy-4-[(3-ethyl-2-benzoxazolinylidene) ethylidene] -5-pyrazolone (XX) 5 (3 -ethyl-2-benzoxazolinylidene) ethylidene] 3-p-hydroxyphenylrhodanine (XXI) 3-carboxymethyl-5-(1-methyl-4(1H)quinoly1- idene)rhodanine (XXII) 5-( 1,-B-carboxyethyl-4 lH)-pyridylidene) rhodanine (XXIII) 5-{[1-(4-carboxybutyl-4-p-chlorophenyl-2- tetrazolin-S-ylidene]ethylidene}-3-ethy1rhodanine (XXIV) 3-ethyl-l-phenyl-5-{[3-(4-sulfobutyl)-2-thiazoidinylidene] ethylidene}-2-thiohydantoin, potassium salt (XXV) l-(Z-diethylaminoethyl)-5-[(3-ethyl-2- benzothiazolinylidene ethylidene] -3-phenylbarbituric acid (XXVI) 3-ethyl-5- (3-ethyl-2-benzothiazolinylidene)isopropylidene]-2-methyl-4-oxo-1-phenyl-2- imidazolinium perchlorate (XXVII) 2-[ 1-ethy1naphtho[1,2-d]thiazolin-Z-ylidene) ethylidene]-1,3-cyclohexanedione (XXVIII) 1,3-diethyl-5-{ [4,6-di(4-fluorophenyl)-lphenyl-2( 1H) -pyridylidene] ethylidene}-2- thiobarbituric acid (XXIX) 1,2-diphenyl-4-{ (3-ethyl-2-benzothiazolinylidene methyl] 1-ethyl-2 1H) -quinolylidene) methyl] methylene}-3,5-pyrazolidinedione (XXX) 1,1-dicyano-2,2-di (3-ethyl-2-benzothiazolinylidene) -methyl] ethylene (XXXI) [3-ethylrhodanine (5)] [3 (2H)-thianaphthenone-1,1-dioxide- (2 ]methineoxonol (XXXII) [7-ethyl-6-oxo-3-phenyl-5,6-dihydroirnidazo [2,1-b] thiazolium(5) [3-ethylrhodanine(5)] methineoxonol Dyes I through VIII are examples of cyanine dyes (dye VIII in a complex cyanine dye), dyes IX through XXVIII are examples of merocyanine dyes, dyes XXIX and XXX are holopolar dyes, and dyes XXXI and XXXII are oxonol dyes. These dyes are all well known in the art and are prepared by conventional synthesis.

The amount of the spectral sensitizing dye used to advantage can be varied over a Wide range and will depend upon the particular emulsion, the particular dye and the effects desired. The operable and preferred amount of a given dye used advantageously to spectrally sensitize a given silver halide emulsion is easily determined by methods well known in the art and need not be discussed further. The dyes are advantageously added to the silver halide emulsion as a solution in water or other suitable solvent, such as, acetone, methanol, pyridine, etc., or mixtures of two or more of these solvents.

As mentioned before, the anthraquinone dye used as a filter dye in my photographic elements is advantageously added to the silver halide emulsion or coated over the silver halide emulsion layer. My anthraquinone dyes have at least one alkaline sulfomethylamino group and have their maximum absorption in the red region of the spectrum with substantially no absorption of light in the blue and green regions of the spectrum. These dyes are water-soluble and have substantially no sensitizing effect on the photographic silver halide emulsion. These dyes have substantially no effect on the quality of the high contrast images formed by development of latent images in the silver halide emulsion layers of my elements. The

anthraquinone dye is substantially completely removed from the photographic element during photographic processing. By alkaline sulfomethylamino group I mean a group represented by the formula:

wherein M represents an alkali metal atom (e.g., sodium, potassium, etc.), ammonium (NH or organic ammonium salt group (e.g., pyridinium, triethylammonium, trimethylammonium, etc.)

The anthraquinone dyes of my invention include those having the formula:

NHCHzSOaM R R 0 R4 i R1 0 Rs H 2 wherein M is as described previously; R, R R R R and R each represents a member such as hydrogen, chlorine, bromine, hydroxyl, methyl, ethyl, propyl, methoxy,

ethoxy, propoxy, a SO M group, a NHCH SO M group, etc.

Preferred examples of anthraquinone dyes used according to my invention include the following:

(A) 1,5-disulfomethylamino-3,7-disulfo-4,8-dihydroxyanthraquinone tetrasodium salt (B) l,5-disulfomethylamino-3,7-disulfo-4,8-dihydroxyanthraquinone tetraammonium salt (C) 1,5-disulfomethylamino-3,7-disulfo-4,8-dihydroxyanthraquinone tetrapotassium salt (D) l,8-disulfomethylaminoanthraquinone disodium salt (E) l,8-disulfomethylamino-3,6-disulfo-4,S-dihydroxyanthraquinone tetrasodium salt (F) 1-sulfomethylamino-3-sulfo-4-hydroxyanthraquinone disodium salt (G) 1,4-disulfomethylaminoanthraquinone disodium salt (H) 1,4-disulfomethylaminoanthraquinone dipyridium salt (I) l,S-disulfomethylaminoanthraquinone disodium salt (J) 1,5-disulfomethylaminoanthraquinone di-triethylammonium salt My anthraquinone dyes are advantageously added as an aqueous solution to a hydrophilic colloid (as described before) either with or Without the silver halide emulsion. The dyes may be used over a wide range of concentrations. An operable range is from about .1 gram to about 50 grams per silver mole. A preferred range of concentration is from about .2 to about 20 grams per silver mole and an especially efiicacious concentration range is from about 1 gram to about 5 grams per silver mole. The amount of dye needed will depend upon the particular dye in question and the amount of the sensitivity of the silver halide emulsion in the red region of the spectrum. The optimum concentration can be determined readily by techniques well known in the art and need not be discussed further herein.

The following examples are included for a further understanding of my invention.

EXAMPLE 1 To separate portions of a fine grain silver chlorobromoiodide gelatin emulsion containing mole percent chloride, 9 mole percent bromide, 1 mole percent iodide, that is chemically sensitized with sufur and gold compounds are added the indicated spectral sensitizers at the indicated concentration (see Table 1) with and without absorbing dye A, i.e., 1,5-disulfomethylamino-3,7-disulfo- 4,8-dihydroxyanthraquinone tetrasodium salt. Each spectrally sensitized emulsion is coated on a separate piece of a polyethylene terephthalate support at 456 mg. silver/ ft. (i.e., 4908 mg./m. 296 mg. gelatin/ft. (i.e., 3181 mg./m. and 296 mg./ft. (i.e., 3181 mg./m. of an alkyl acrylate polymer of the type described in French Patent 1,510,222 dlivre Dec. 11, 1967. A gelatin overcoat is coated on the emulsion layer of each coating at 82.6 mg./ft. 2 (i.e., 889 mg./m. After drying the fol lowing exposures are made on each of the coatings. A sensitometric exposure to white light is made on one area of a piece of each coating and a sensitometric exposure to red light is made on another area of each coating to determine white and red light speeds. On a still different unexposed area of each coating a safelight safety test is made by exposing through a sensitometric step tablet having consecutive steps which produce 0.3 log E increments in exposure and have printed on each step an identifying number for seconds to a 500 w. tungsten light source modulated by a Wratten safelight series 1 filter (Eastman Kodak Company trademark and designation for a redcolored safelight filter) from a distance of about one foot (i.e., about 30.48 cm.). All the exposed coatings are developed for 1% minutes in an amine-developer roller transport processor system as described in Belgian Patent 704,595. After fixing with a conventional sodium thiosulfate fixing bath, washing and drying, the contrasts, relative white light speeds and relative red light speeds are determined from the processed film samples. From the last number that can be read on the developed safelight safety test step tablet image, a safelight safety value is determined from a table. Safelight safety test values of 90 and above are considered excellent, values from 45 to 90 are considered acceptable and values less than 45 are considered poor. Even though safelight safety test values of 90 are considered excellent, it is desirable to obtain higher values since they indicate that the light sensitive material is even less sensitive to the red safelight and can be used with more freedom under the safelight without causing fog. A net safelight safety value is determined by normalizing the relative red light speed to relative white light speed with the difference illustrating that the absorbing dye results in higher red light absorption than blue or green light absorption. Therefore, the net safelight safety values, when adjusted for differences in white light speed, result in slower red light speed 20 with the absorbing dye than the corresponding coating without the absorbing dye. The following Table 1 summarizes the results.

Red light-absorbing dyes outside my invention such as 3 methyl-4-{6-[3-(4-sulfobutyl)-2-benzoxazolinylidene]- 1,3-neopentylene 2,4 hexadienylidene}-1-p-sulfophenyl- 2-pyrazolin-5-one, 3 methyl-4-{6-[3-(3-sulfopropyl)-2- benzoxazolinylidene] 1,3 neopentylene 2,4 hexadienylidene} 1 p sulfophenyl-Z-pyrazolin-5-one, bis[1,3- di-(S-carboxypentyl) 2 thiobarbituric acid(5)] pentamethine oxonol, bis[l-butyl 3 carboxymethylbarbituric acid(5)]pentamethine oxonol cannot be used in place of my red light-absorbing dyes because they cause detrimental loss in the quality of the high contrast images developed from latent images in my silver chlorobromide emulsions. These dyes also produce an undesired increase in red sensitivity in my orthochromatically sensitized silver halide emulsions.

My photographic elements provide a valuable technical advance in the art because they are photographically faster, because of the orthochromatic sensitization, produce excellent quality high contrast image reproductions and because they have excellent red safelight safety values.

The invention has been described in detail with particular embodiments thereof, but it will be understood TABLE 1 Relative red light Llght- Safespeed minus sensitizing llgh re ve ing dye, safety white light Gms/Mol Dye class 2.0 g./m. Contrast value speed 16 Cyanine None. 4.2 16 do A 4.8 22 Complexcyanine. None.... 7.0 22 do 7.0 Merocyani 9.0 10 do.. 6.9 6.9 7.4 9.0 7.5 9.9 II 10.5 XXIX 6.5 XXIX 5.5 XXX 6.2 XXX 6.1 XXXI None 7.4 XXXI 10 d0 6.5 XXXIII 13 d0 None... 6.9 2 XXXIII 13 d0 A 6.5

The even numbered coatings 2, 4, 6, 8, 10, 12, 14, 16, 18 and are of my invention while the odd numbered coatings are outside my invention and are used for controls, for example, coating 1 is used as a control for coating 2, coating 3 is used as a control for coating 4, etc. The results show that my coatings each have a substantially higher safelight safety value than the respective control coating. Coatings 5, 7, 11 and 19 outside my invention have only poor safelight safety values. My coatings 8, 12 and 20 have acceptable safelight safety values and my coatings 2, 4, 6, 10, 14, 16 and 18 have excellent safelight safety values. Even though coatings 1 and 3 have excellent safelight safety test values, the addition of light absorbing dye A increased the safelight safety test value up to 525 representing a valuable technical advance.

EXAMPLE 2 Example 1 is repeated using light-absorbing dyes B, C, D, E, F, G, H, I and J in place of dye A. Results similar to those obtained in my Example 1 coatings containing dye A are obtained for each of dyes B through I.

Similar results to those obtained in Examples 1 and 2 are obtained when other fine grain silver chlorobrornoiodide gelatin emulsions are used containing at least 60 mole percent chloride, less than mole percent bromide and less than about 5 mole percent iodide.

Similar results are obtained when the above examples are repeated using other high contrast and especially lithographic developer solutions and processes known in the art.

that variations and modifications can be effected within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

I claim:

1. A lith-type photographic element comprising a support coated with a hydrophilic colloid layer containing a fine grain, high contrast silver halide emulsion in which the said silver halide contains at least about 60 mole percent chloride, less than about 40 mole percent bromide and less than about 5 mole percent iodide, a sensitizing dye that orthochromatically sensitizes the said silver halide and produces a modicum of sensitivity in the red region of the spectrum, said sensitizing dye being substantially completely decolorized during photographic processing, and as a filter dye for said silver halide emulsion a watersoluble anthraquinone dye having at least one alkaline sulfomethylamino group which has substantially no absorption of light in the blue and green regions of the spectrum and which strongly absorbs light in the red region of the spectrum, and which produces substantially no change in quality of high contrast images produced by development of latent images in the said silver halide emulsion, said anthraquinone dye being substantially completely removed from the photographic element during photographic processing.

2. A lith-type photographic element comprising a support coated with a hydrophilic colloid layer containing a fine grain, high contrast silver halide emulsion in which the said silver halide contains at least about 60 mole percent chloride, less than about 40 mole percent bromide and less than about mole percent iodide, a sensitizing dye selected from the class consisting of a cyanine dye, a merocyanine dye, a holopolar dye, and an oxonol dye that orthochromatically sensitizes the said silver halide and produces a modicum of sensitivity in the red region of the spectrum, said sensitizing dye being substantially completely decolorized during photographic processing, and as a filter dye for said silver halide emulsion a watersoluble anthraquinone dye having at least one alkaline sulfomethylamino group which has substantially no absorption of light in the blue and green regions of the spectrum and which strongly absorbs light in the red region of the spectrum, and which produces substantially no change in quality of high contrast images produced by development of latent images in the said silver halide emulsion, said anthraquinone dye being substantially completely removed from the photographic element during photographic processing.

3. A lith-type photographic element comprising a support coated with a hydrophilic colloid layer containing a fine grain, high contrast silver halide emulsion in which the said silver halide contains at least about 60 mole percent chloride, less than about 40 mol percent bromide and less than about 5 mole percent iodide, a merocyanine sensitizing dye that orthochromatically sensitizes the said silver halide and produces a modicum of sensitivity in the red region of the spectrum, said sensitizing dye being substantially completely decolorized during photographic processing, and as a filter dye for said silver halide emulsion a water'soluble anthraquinone dye having at least one alkaline sulfomethylamino group which has substantially no absorption of light in the blue and green regions of the spectrum and which strongly absorbs light in the red region of the spectrum, and which produces substantially no change in quality of high contrast images produced by development of latent images in the said silver halide emulsion, said anthraquinone dye being substantially completely removed from the photographic element during photographic processing.

4. A lith-type photographic element comprising a support coated with a hydrophilic colloid layer containing a fine grain, high contrast silver halide emulsion in which the said silver halide contains at least about 60 mole percent chloride, less than about 40 mole percent bromide and less than about 5 mole percent iodide, an acid substituted merocyanine sensitizing dye that orthochromatically sensitizes the said silver halide and produces a modicum of sensitivity in the red region of the spectrum, said sensitizing dye being substantially completely decolorized during photographic processing, and as a filter dye for said silver halide emulsion a water-soluble anthraquinone dye having at least one alkaline sulfomethylamino group which has substantially no absorption of light in the blue and green regions of the spectrum and which strongly absorbs light in the red region of the spectrum, and which produces substantially no change in quality of high contrast images produced by development of latent images in the said silver halide emulsion, said anthraquinone dye being substantially completely removed from the photographic element during photographic processing.

5. A photographic element of claim 4 in which the said merocyanine dye contains a rhodanine nucleus.

6. A photographic element of claim 4 in which the said merocyanine dye contains a thiohydantoin nucleus.

7. A photographic element of said claim 2 in which the said anthraquinone dye is in a hydrophilic colloid layer coated over the hydrophilic colloid layer containing the said silver halide emulsion.

8. A photographic element of claim 2 in which the said anthraquinone dye is in the same hydrophilic colloid layer that contains the said silver halide emulsion.

9. A photographic element of claim 2 in which the said anthraquinone dye is represented by the formula:

0 NHOHzSOsM R5 H R 0 C B5 II R2 wherein M represents a member selected from the class consisting of an alkali metal atom, the ammonium group, and an organic ammonium salt group; R, R R R R and R each represents a member selected from the class consisting of hydrogen, chlorine, bromine, the hydroxyl group, methyl, ethyl, methoxy, ethoxy, a SO M group and a -NHCH SO M group.

10. A photographic element of claim 2 in which the said sensitizing dye is anhydro-5,6-dichloro-1,3'-diethyl-3- (3-sulfopropyl)benzimidazolooxacarbocyanine hydroxide.

11. A photographic element of claim 2 in which the said sensitizing dye is 1,2-diphenyl-4-{[(3-ethyl-2-benzothiazolinylidene)methyl][(l ethyl 2(1H) quinolylidene)methyl]methylene}-3,S-pyrazolidinedione.

12. A photographic element of claim 2 in which the said sensitizing dye is 3-carboXymethyl-l,5-[(3-methyl-2- thiazolidinylidine)isopropylidene]rhodanine.

13. A photographic element of claim 2 in which the said sensitizing dye is 5-[ (3-ethylnaphth[2,1-a] oXazolin-2- ylidene)ethylidene] 3 N heptyl-1-phenyl-2-thiohydantoin.

14. A photographic element of claim 2 in which the said sensitizing dye is 5-[(3-ethyl-2-benzoxazolinylidene) ethylidene] -3-heptyl-1-phenyl-2-thiohydantoin.

15. A photographic element of claim 2 in which the said sensitizing dye is 3-ethyl-5-{[3-(4-sulfobutyl)-2-thiaazolidinylidene]ethylidene}rhodanine, potassium salt.

16. A photographic element of claim 3 in which the said anthraquinone dye has at least one alkaline sultomethylamino group.

References Cited UNITED STATES PATENTS 2,456,956 12/1948 Knott et al. 96-64 2,622,082 12/ 1952 Sprague 260--240.9X 2,865,752 12/1958 Saunders et al. 96l02 NORMAN G. TORCHIN, Primary Examiner A. T. SURO PICO, Assistant Examiner US. Cl. X.R. 96106