CA1120936A - Acylhydrazinophenylthiourea nucleating agents and photographic elements containing such agents - Google Patents

Abstract

Abstract of the Disclosure Novel 3,3-disubstituted acylhydrazinophenyl-thiourea nucleating agents are disclosed as well as silver halide photographic emulsions and elements con-taining silver halide grains capable of forming an internal latent image having the nucleating agents adsorbed to the surface of the silver halide grains. Imaging processes in which these materials participate are also disclosed.

Description

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ACYLHYDRAZINOPHENYLTHIOUREA NUCLEATING AGENTS AND
PHOTOGRAPHIC EMULSIONS AND ELEMENTS CONGAINING SUCH AGENTS
Field of the Invention The present invention is directed to novel photographic emulsions and elements and to novel adsorbed arylhydrazide nucleating agents. More specifically, this invention is directed to novel adsorbed arylhydrazino-phenylthiourea nucleating agents and to photographic emulsions and elements containing such nucleating agents in combination with silver halide grains capable of form-ing an internal latent image.
Background of the Invention _ Photographic elements which produce images having an optical density directly related to the radia-tion received on exposure are said to be negative-working.
A positive photographic image can be formed by producing a negative photographic image and then forming a second photographic image which is a negative of the f`irst nega-tive--that is, a positive image. A direct-positive image is understood in photography to be a positive image that is formed without first forming a negative image. Posi-tive dye images which are not direct-positive images are commonly produced in color photography by reversal process-ing in which a negative silver image is formed and a complementary positive dye image is then formed in the same photographic element. ~he term "direct reversal" has been applied to direct-positive photographic elements and processing which produces a positive dye image without forming a negative silver image. Direct-positive photogra-3 phy in general and direct reversal photography in particularare advantageous in providing a more straightforward approach to obtaining positive photographic images.
A conventional approach to forming direct-positive images is to use photographic elements employing internal latent image-forming silver halide grains. After imagewise exposure, the silver halide grains are developed with a surface developer--that is, one which will leave the latent image sites within the silver halide grains , ~

. ~

substantially unrevealed. Simultaneously, either by uni-form light exposure or by the use of a nucleating agent, the silver halide grains are subjected to development con-ditions that would cause fogging of a negative-working photographic element. The internal latent image-forming silver halide grains which received actinic radiation dur-ing imagewise exposure develop under these conditions at a comparatively slow rate, as compared to the internal latent image-forming silver halide grains not imagewise exposed.
The result is a direct-positive silver image. In color photography, the oxidized developer that is produced during silver development is used to produce a corresponding posi-tive, direct reversal dye image. Multicolor direct reversal photographic images have been extensively investigated in connection with image-transfer photography.
It has been found advantageous to employ nucleat-ing agents in preference to uniform light exposure in the process described above. The term "nucleating agent" is employed herein in its art-recognized usage to mean a fog-ging agent capable of permitting the se].ective development of internal latent image-forming silver halide grains which have not been imagewise exposed in preference to the develop-ment of silver halide grains having an internal latent image formed by imagewise exposure.
A favored class of nucleating agents is arylhydra-zides. These nucleating agents can be incorporated in a developer solution or directly within a photographic element.
Significant advantages have been realized by adsorbing aryl-hydrazide nucleating agents to the surface of internal latent 3 image-forming silver halide grains. This permits small amounts of the nucleating agents to be employed, as compared with those which are nonadsorbed. However, this narrows the choice of arylhydrazide nucleating agents to those including an adsorption-promoting moiety.
Highly effective adsorbed arylhydrazide nucleating agents are the acylhydrazinophenylthioureas of Leone et al U.S. Patent 4,030,925. These acylhydrazinophenylthioureas are characterized by the 3-position nitrogen atom of the thiourea moiety being mono-substituted.

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Summary of the Invention This invention has as its purpose to provide novel and highly effective acylhydrazinophenylthiourea nuc-leating agents. It is a more specific purpose of this inven-tion to provide photographic silve-r halide emulsions and ele-ments containing these novel arylhydrazinophenylthiourea nucleating agents. The invention provides acylhydrazino-phenylthiourea nucleating agents of higher levels of activ-ity which minimize infectious development. The invention also permits photographic processing at reduced pH levels while sustaining nucleating activity.
This invention is directed to 3~3-disubstituted arylhydrazinophenylthiourea nucleating agents, silver halide emulsions containing such nucleating agents and silver halide photographic elements containing at least one silver halide emulsion layer containing such nucleating agents.
In one specific aspect, this invention is directed to a silver halide emulsion comprised of silver halide grains capable of forming an internal latent image and, adsorbed to the surface of the silver halide grains, a nucleating amount of a 3,3-disubstituted acylhydrazinophenylthiourea.
In another aspect, this invention is directed to a photographic element comprised of a support and, coated on the support, a silver halide emulsion layer comprising sil-ver halide grains capable of forming an internal latent imageand, adsorbed to the surface of said silver halide grains, a nucleating amount of a 3,3-disubstituted acylhydrazinophenyl-thiourea.
In still another aspect, this invention is direct-3 ed to a process of obtaining a direct-positive image com-prising imagewise exposing a photographic element according to this invention and selectively developing the silver halide grains remaining unexposed.
Preferred 3,3-disubstituted acylhydrazinophenyl-thiourea nucleating agents are those of the formula tI) O S
1~ H H H 11 ~R2 R C N N R ~ N C N

:. . , .

, --4--wherein R is hydrogen; an alkyl, cycloalkyl, haloalkyl, alkoxyalkyl or phenylalkyl substituent or a phenyl nucleus having a Hammett sigma value-derived electron-withdrawing characteristic more positive than -0.3;
Rl is a phenylene or alkyl, halo- or alkoxy-substituted phenylene group; and R2 and R3 are ~ndependently selected from among alkyl, haloalkyl, alkoxyalkyl or phenylalkyl substituents 10 having from 1 to 18 carbon atoms; a cycloalkyl substituent;
a phenyl nucleus having a Hammett sigma value-derived electron-withdrawing characteristic less positive than +0.50; and naphthyl; or R2 and R3 together form a hetero-cyclic nucleus forming a 5- or 6-membered ringg wherein 15 the ring atoms are chosen from the class consisting of nitrogen, carbon, oxygen, sulfur and selenium atoms;
the alkyl moieties, except as otherwise noted, in each instance include from 1 to 6 carbon atoms; and the cycloalkyl moieties have from 3 to 10 carbon 20 atoms.
More specifically preferred 3,3-disubstituted acylhydrazinophenylthiourea nucleating agents are those of the formula:
(II) O S
11 H H 9--~ H 11 R2 H-C-N-N-o\ /~-N C N\R3 wherein R2 and R3 are independently selected from among alkyl and phenylalkyl substituents, wherein the al~yl moieties 3 are in each instance from 1 to 6 carbon atoms, and a phenyl nucleus having a Hammett sigma value-derived elec-tron-withdrawing characteristic less positive than +0.50;
or R and R3 together form a saturated heterocyclic nucleus forming a 5- or 6-membered ring, wherein the ring atoms 35 are chosen from the class consisting of nitrogen, carbon, oxygen, sulfur and selenium atoms.
Description of the Preferred Embodiments As indicated by R in formula (I), preferred 3,3-disubstituted arylhydrazinophenyithioureas employed in , .

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the practice of this invention contain an acyl group which is the residue of a carboxylic acid, such as one of the acyclic carboxylic acids, including formic acid, acetic acid, propionic acid, butyric acid, higher homologues of these acids having up to about 7 carbon atoms, and halogen, alkoxy, phenyl and equivalent substituted derivatives thereof. In a preferred form, the acyl group is formed by an unsubstituted acyclic aliphatic carboxylic acid having from 1 to 5 carbon atoms. From formula ~II), it is 10 apparent that a specifically preferred acyl group is formyl. The alkyl moieties in the substituents to the carboxylic acids are contemplated to have from 1 to 6 carbon atoms, preferably from 1 to 4 carbon atoms.
In addition to the acyclic aliphatic carboxylic 15 acids, it is recognized that the carboxylic acid can be chosen so that R is a cyclic aliphatic group having from about 3 to 10 carbon atoms, such as cyclopropyl, cyclo-butyl, cyclopentyl, cyclohexyl, methylcyclohexyl, cyclo-octyl, cyclodecyl and bridged ring variations, such as 20 bornyl and isobornyl groups. Cyclohexyl is a specifically preferred cycloalkyl substituent. The use of alkoxy, cyano, halogen and equivalent substituted cycloalkyl substituents is contemplated.
In still another form, R can be the residue of 25 an aromatic carboxylic acid, such as benzoic acid and sub-stituted derivatives thereof. R can take the form of a phenyl nucleus which is either electron-donating (electro-positive) or electron-withdrawing (electronegative);
however, phenyl nuclei which are highly electron-donating 30 may produce inferior nucleating agents. The electron-withdrawing or electron-donating characteristic of a specific phenyl nucleus can be assessed by reference to Hammett sigma values. The phenyl nucleus can be assigned a Hammett sigma value-derived electron-withdrawing char acteristic which is the algebraic sum of the Hammett sigma values of its substituents ~i.e., those of the substituents, if any, to the phenyl group~. For example~ the Hammett sigma values of any substituents to the phenyl ring of the phenyl nucleus can be determined algebraically simply by determining from the literature the known Hammett sigma values for each substituent and obtaining the algebraic sum thereof. ~lectron-~ithdrawing substituents are assigned positive sigma values, while electron-donatin~
substituents are assigned negative sigma values. In a preferred form, R is a phenyl nucleus having a Hammett sigma value-derived electron-withdrawing characteristic more positive than -0.3.
~xemplary meta- and para-sigma values and pro-cedures for their determination are set forth by J. Hine in Physical Organic Chemistry, second edition, page 87, published in 1962, H. VanBekkum, P. E. Verkade and B. M.
Wepster in Rec. Trav. Chim., Volume 78, page 815, published 15 in 1959, P. R. Wells in Chem. Revs., Volume 63, page 171, published in 1963, by H. H. Jaffe in Chem. Revs., Volume 53, page 191, published in 1953, by M. J. S. Dewar and P.
J. Grisdale in J. Amer. Chem. Soc., ~olume 84, page 3548, published in 1962, and by Barlin and Perrin in ~uart.
20 Revs., Volume 20, page 75 et seq, published in 1966. For the purposes of this invention, ortho- substituents to the phenyl ring can be assigned to the published para- sigma ; values.
In a preferred form, R can be the residue of an 25 aromatic carboxylic acid, such as benzoic acid; alkyl, halo-, cyano or alkoxy-substituted benzoic acid or an equivalent thereof. Where R is the residue of a substi-tuted benzoic acid, it is preferred that the benzoic acid be para- or 4-ring position substituted. The alkyl moieties 3 of the ring substituents preferably have from 1 to 6 carbon atoms. Fluoro~ chloro, bromo, iodo and cyano ring substituents are specifically contemplated. It is also contemplated that R can be the residue of naphthoic acid.
As indicated by Rl in formula ~I~, preferred 3,3-disubstituted arylhydrazinophenylthioureas employed in the practice of this invention contain a phenylene or substituted phenylene group. Specifically preferred , :

-, :
, ' .

3~3~

phenylene groups are m- and p-phenylene groups. Exemplary of preferred phenylene substituents are alkoxy substituents ha~ing from 1 to 6 carbon atoms, alkyl substituents having from 1 to 6 earbon atoms, fluoro-, chloro-, bromo- and iodo-substituents. Unsubstituted p-phenylene groups are specifically preferred. Specifically preferred alkyl moieties are those whieh have from 1 to 4 carbon atoms.
While phenylene and substituted phenylene groups are preferred linking groups~ other functionally equivalent 10 divalent aryl groups, such as naphthalene groups, can be employed.
Referring again to formula tI), it is apparent that R2 and R3 can independently take a variety of forms.
One specifically eontemplated form ean be an alkyl group 15 or a substituted alkyl group, such as a haloalkyl group, alkoxyalkyl group, phenylalkyl group, or equivalent group, having a total of up to 18, preferably up to 12, earbon atoms. Specifically R2 and/or R3 can take the form of a methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, 20 nonyl, decyl or higher homologue group having up to 18 total carbon atoms; a fluoro-, chloro-, bromo- or iodo-substituted derivative thereof; a methoxy, ethoxy, pro-poxy, butoxy or higher homologue alkoxy substituted deriva-tive thereof, wherein the total number of carbon atoms are 25 neeessarily at least 2 up to 18; and a phenyl-substituted derivative thereof, wherein the total number of earbon atoms is necessarily at least 7, as in the case of benzyl, up to about 18. In a specific preferred form indicated in formula tII) R2 and/or R3 can take the form of an alkyl or 3 phenylalkyl substituent, wherein the alkyl moieties are in each instance fr-om 1 to 6 carbon atoms.
In addition to the acyclic aliphatic and aromatic forms discussed above, it is also contemplated that R2 and~or R3 can take the form of a cyclic aliphatic substitu-ent, such as a cycloalkyl substituent havin~ from 3 to 10carbon atoms. The use of cyclopropyl, cyclobutyl, cyclopentyl~ cyclohexyl, methylcyclohexyl, cyclo-octyl, cyclodecyl and bridged ring variations, such as `' . .

. ~ ~
, . .

bornyl and isobornyl groups, is contemplated. Cyclohexyl is a preferred cycloalkyl substituent. The use of alkoxy, cyano, halogen and equivalent substituted cycloalkyl substituents is contemplated.
R2 and/or R3 can also be an aromatic substituent, such as phenyl or naphthyl (i.e., l-naphthyl or 2-naphthyl) or an equivalent aromatic group--e.g., 1-, 2- or 9-anthryl, etc. As indicated in both ~ormula ~I~ and formula ~II) R2 and/or R3 can take the form of a phenyl nucleus which is 10 either electron-donating or electron-withdrawing, however phenyl nuclei which are highly electron-withdrawing may produce inferior nucleating agents. For this reason, it is preferred that R2 and/or R3 be a phenyl nucleus having a Hammett sigma value-derived electron-withdrawing charac-15 teristic less positive than +0.50. It is specificallycontemplated that R2 and/or R3 be chosen from among phenyl nuclei having cyano, fluoro-, chloro-, bromo-, iodo-, alkyl groups having from 1 to 6 carbon atoms and alkoxy groups having from 1 to 6 carbon atoms and al~oxy groups 23 having from 1 to 6 carbon atoms, as phenyl ring substituents.
Phenyl ring substituents are preferred in the para- or 4- ring position.
Rather than being independently chosen R2 and R can together form, along with the 3-position nitrogen 25 atom of the thiourea, a heterocyclic nucleus forming a 5-or 6-membered ring. The ring atoms can be chosen from among nitrogen, carbon, oxygen, sulfur and selenium atoms.
The ring necessarily contains at least one nitrogen atom.
Exemplary rings include morpholino, piperidino, pyrrolidinyl, 30 pyrrolinyl, thiomorpholino, thiazolidinyl, 4-thiazolinyl, selenazolidinyl, 4-selenazolinyl, imidazolidinyl, imida-zolinyl 3 oxazolidinyl and 4-oxazolinyl rings. Specifically preferred rings are saturated or otherwise constructed to avoid electron withdrawal from the 3-position nitrogen atom.
To synthesize the 3,3-disubstituted acylhydra zinophenylthioureas of this invention, nitrophenylhydra-zine can be employed as a starting material and can be used to form the desired l-acyl-2-~aminophenyl~hydrazine '...~' ;

:, , :: , . . .
. ~ : , . . -3~

using procedures that are generally described and specific-ally exemplified in Leone U.S. Patent 4,030,925.
A general procedure for syn~hesis using a l-acyl-

2-(aminophenyl)hydrazine as a starting material is to dis-solve this material in acetone and to cool the resultingsolution to -78C in a dry ice-acetone bath. The l-acyl-2-(aminophenyl)hydrazine is then reacted with 1,1'-thiocarbonyldiimidazole. The reaction mixture ;s allowed to warm to room temperature and then the solvent is re-moved. The remaining solid residue consists essentially ofa mixture of a 2-acylhydrazinophenylisothiocyanate and imidazole. The solid is washed ~horoughly with water to remove the imidazole, and the remaining material is recrys-tallized from acetone to give the 2-acylhydrazinophenyl-isothiocyanate separated from the imidazole. The isothio-cyanate is then reacted in a suitable solvent, such as, ethanol or acetonitrile, with a secondary amine, where R 2 and R 3 are independent substituents, or a heterocyclic compound having a functionally equivalent nitrogen atom, where R 2 and R 3 together orm a heterocyclic ring.
After a few minutes reflux the 1-(2-acylhydrazino-phenyl)-3,3-disubs~ituted thiourea separates from the solu-tion as a precipitate. The solid product can be filtered off, washed with ether and dried for subsequen~ use.
This synthesis can be summarized as follows:
(III) O S
R-C-N-N-Rl-NH2 + ~ ~-C-N/ ~-78~C
o R-C N-N-R'-N=C=S
(IV) o Il H H R2 R_C-N-N-RI-N=c=s + R 3~solvent >

O S
Il H H H ll R-C-N-N-Rl-N-C-N

, , ~
; ~ . .

~ here a thiocarbamoyl chloride is available which contains substituents corresponding to the desired R and R3 substituents, such as dimethyl or diethyl carbamoyl chloride, an alternative synthetic route is to react the carbamoyl chloride with a desired 1-acyl-2-(aminophenyl~-hydrazine in an inert solvent, such as acetonitrile, in the presence of a base, such as trimethylamine, under a nitro~en atmosphere at room temperature. The mixture is chilled and the product separates out of solution. The 10 solid is filtered off and then stirred in warm water to remove hydrochloride salts. The remaining solid material represents the 3,3-disubstituted-1-~acylhydrazinophenyl)-thiourea.
This synthesis can be summarized as follows:
15 (IV) Il H H R2 11 Et N
R--C--N--N--R1--NH + ~N--C--C 1 3 2 R3/ MeCN

Il H H H 11 R2 R C N N Rl--N C N/

Illustrative specific 3,3-disubstituted acyl-hydrazinophenylthioureas useful in the practice of this invention include those set forth below in Table I.
TABLE I
NA- 1 1-~4-(2-formylhydrazino)phenyl~-3,3-di-methylthiourea NA 2 1-[4-(2-formylhydrazino)phenyl]-3,3-di-(chloroethyl)thiourea

3 NA- 3 1-[2-(2-formylhydrazino)phenyl]-3,3-di- ;
methylthiourea NA- 4 1-[3-(2-~ormylhydrazino~phenyl]--3,3-di-methylthiourea NA- 5 1-[4-~2-acetylhydrazino)phenyl] 3,3-di-methylthiourea NA- 6 1-[4-(2-chloroacetylhydrazino~phenyl]-3,3-dimethylthiourea .--:- . :
::
:' 3~;

NA- 7 1-[4-(2-methoxyacetylhydrazino)phenyl]-3,3-dimethylthiourea NA- 8 1-[4-~2~heptanoylhydrazino~phenyl~-3,3-dimethylthiourea NA- 9 1-[4-~2-cyclobutanoylhydrazino)phenyl-3,3-dimethylthiourea NA-10 1-{4-[2-~4-cyanobenzoyl)hydrazino]-phenyl}-3~3-dimethylthiourea NA-ll 1-[4-(Z-formylhydrazino~phenyl]-3,3-di-benzylthiourea NA-12 1-[4-(2-acetylhydrazino)phenyl]-3,3-di-benzylthiourea NA-13 1-{4-[2-(4-chlorobenzoyl)hydrazino]-phenyl} 3,3-dibenzylthiourea 15 NA-14 1-~4-(2-formylhydrazino)phenyl]-3-methyl-3-phenylthiourea NA-15 1-[4-(2-formylhydrazino)phenyl]-3g3-di-butylthiourea NA-16 1-[4-C2-formylhydrazino)phenyl]-3-methyl-3-(2-ethoxy)ethylthiourea NA-17 1-[4-(2-formylhydrazino)phenyl]-3,3-di-hexylthiourea NA-18 1-[4-(2-formylhydrazino)phenyl]-3,3-di-dodecylthiourea 25 NA-l9 1-[4-(2-acetylhydrazino)phenyl]-3,3-di-octadecylthiourea NA-20 1-{4-[2-(2-bromobenzoyl)]phenyl}-3,3-di-methylthiourea NA-21 4-[4-(2-formylhydrazino)phenylthiocarb-3 amoyl~morPholine NA-22 4-[4-(2-formylhydrazino)phenylthiocarb- ;
amoyl]thiomorpholine NA-23 3-[4-(2-formylhydrazino)phenylthiocarb-amoyl]thiazolidine 35 NA-24 3-[4-(2-formylhydrazino)phenylthiocarb-amoyl]-4-thiazoline ; NA-25 1-[4-(2-formylhydrazino)phenylthiocarb-amoyl]-3-pyrroline .:
:

NA-26 1-[4-(2-formylhyclrazino)phenylthiocarb-amo~l]pyrrolidine NA-27 1-~4-(2-formylhydrazino)phenylthiocarb-amoyl]imidazolidine NA-28 1-[4-(2-formylhydrazino)phenylthiocarb-amoyl~-2-imidazoline NA-29 3-[4-(2-formylhydrazino)phenylthiocarb amoyl~oxazolidine NA-30 3-C4-(2-formylhydrazino)phenylthiocarb-amoyl]-4-oxazoline NA-31 1-[4-(2-formylhydrazino)phenyl]-3,3-(di-2-naphthyl)thiourea NA-32 1-[4-(2-formylhydrazino)phenylthiocarb-amoyl]piperidine 15 NA-33 1-{4-~2-(4-chlorobenzoyl)hydrazino]phenyl-thiocarbamoyl}piperidine The 3,3-disubstituted arylhydrazinophenylthiourea nucleating agents can be employed with any conventional photographic element capable of forming a direct-positive image containing, coated on a photographic support, at least one silver halide emulsion layer containing a vehicle and silver halide grains capable of forming an internal latent image upon exposure to actinic radiation. As employed herein, the terms "internal latent image silver ; 25 halide grains" and "silver halide grains capable of form-ing an internal latent image" are employed in the art recognized sense of designating s1lver halide grains which produce substantially higher optical densities when coated, imagewise exposed and developed in an internal developer than when comparably coated~ exposed and devel-oped in a surface developer. Preferred internal latent image silver halide grains are those which~ when examined according to normal photographic testing techniques, by coating a test portion on a photographic support at a density of from 3 to 4 grams per square meter, exposing to ; a light intensity scale ~such as~ for example, with a 500-watt tungsten lamp at a distance of 61 cm) for a fixed time between 1 x 10 2 and 1 second and developing for 5 , ~' ' '' ' " ` .

minutes at 25C in Kodak~ Developer DK-50 ~a æurface developer), provide a density of at least 0.5 less than when this testing procedure is repeated, substituting for the surface developer Kodak~ Developer DK-50 containing 0.5 gram per liter of potassium iodide (an internal devel-oper). The internal latent image silver hallde grains most preferred for use in the practice of this invention are those which, when tested using an internal developer and a surface developer as indicated above, produce an optical density with the internal developer at least 5 times that produced by the surface developer. It is addi-tionally preferred that the internal latent image silver halide grains produce an optical density of less than 0.4 and, most preferably, less than 0.25 when coated, exposed and developed in surface developer as indicated nbove--that is~ the silver halide grains are initially substantially unfogged and free of latent image on their surace.
The surEace developer referred to herein as Kodak~ Developer DK-50 is described in the Handbook of ChemLs ry and Physics, 30th edition, 1947, Ghemical Rubber Publishing Company, Cleveland, Ohio, page 2558, and has the following composition:
Water, about 125F (52C? 500.0 cc N-methyl-p-aminophenol sulfate2.5 g Sodium sulfite, desiccated30~0 g Hydroquinone 2.5 g Sodium metaborate 10.0 g Potasslum bromide 0.5 g Water to make 1.0 liter.
Internal latent image silver halide grains which can be employed in the practice of this invention are well known in the art. Patents teaching the use of internal latent image silver halide grains in photographic emulsions and elements include Davey et al U.S. Patent 2,592,250, issued May 8, 1952; Porter et al U.S. Patent 3,206,313, issued September 14, 1965; Milton U~S. Patent 3,761j266, issued September 25~ 1973; Ridgway U.S. Patent 3,586,505, issued June 22, 1971; Gilman et al U.S. Patent 3,772,030, ~ , . -,. . . .

issued November 13, 1973; Gilman et al U.S. Patent 3,761,267, issued September 25, 1973; and Evans U.S.
Pa~ent 3,761,276, issued September 25, 1973.
The internal latent image silver halide grains preferably contain bromide as the predominant halide.
The silver bromide grains can consist essentially of silver bromide or can contain silver bromoiodide, silver chlorobromide, silver chlorobromoiodide crystals and mixtures thereof. Internal latent image-forming sites 10 can be incorporated into the grains by either physical or chemical internal sensitization. Davey et al, cited above, for example, teaches the physical formation of internal latent image-forming sites by the halide con-version technique. Chemical formation of internal la-15 tent image-forming sites can be produced through the use of sulfur, gold, selenium, tellurium and/or reduction sensitizers of the type described, for example, in Sheppard et al U.S. Patent 1,623,499, issued April 5, 1927; Waller et al U.S. Patent 2,399,083, issued April 20 23, 1946; McVeigh U.S. Patent 3,297,447, issued January 10, 1967 and Dunn U.S. Patent 3,297,446, issued January 10, 1967, as taught in the paten~s cited in the preced-ing paragraph. Internal latent image si~es can also beformed through the incorporation of me~al dopants~ par-25 ticularly Group VIII noble metals, such as, ruthenium,rhodium, palladium, iridium, os~ium and platinum, as taught by Berriman U.S. Patent 3,367,778, issued February 6, 1968~ The preferred foreign metal ions are polyvalent metal ions which include the above-noted 30 Group VIII dopants, as well as polyvalent metal ions, such as, lead, antimony, bismuth, arsenic and the like.
In highly preferred embodiments, the silver halide grains are formed in the presence of bismuth, lead or iridium ions. In a preferred approach, the internal 35 latent image sites can be formed within the silver ha-lide grains during precipitation of silver halide. In an alternate approach, a core grain can be formed which is treated to form the internal image sites and then a ,, ~.;.

. ~ ~

shell deposited over the core grains, as taught by Porter et al, cited above.
The silver halide grains employed in the practice of this invention are preferably monodispersed, and in some embodiments are preferably large-grain emulsions made according to Wilgus German OLS 2,1077118, published September 2, 1971. The mono-dispersed emulsions are those which comprise silver halide grains having a substantially uniform diameter.
10 Generally, in such ~mulsions, no more than about 5 percent by number of the silver halide grains smaller than the mean grain size and/or no more than about 5 percent by number of the silver halide grains larger than the mean grain size vary in diameter from the mean 15 grain diameter by more than about 40 percent.
Preferred photographic emulsions of this invention comprise silver halide grains, at least g5 percent by weight of said grains having a diameter which is within 40 percent and preferably within about 30 percent of 20 the mean grain diameter. Mean grain diameter, i.e., average grain size, can be determined using conventional methods, e.g., such as projective area, as shown in an article by Trivelli et al entitled "Empirical Relations Between Sensitometric and Size-Frequency Characterlstics in Photographic Emulsion Series" in The Photographic Journal, Volume LXXIX, 19~9, pages 330 through 338. The aforementioned uniform size distribution of silver halide grains is a characteristic of the grains in monodispersed 30 photographic silver halide emulsionsO Silver halide ~;
grains having a narrow size distribution can be obtained by controlling the conditions at which the silver halide grains are prepared using a double run procedure. In such a procedure, the silver halide 35 grains are prepared by simultaneously running an aqueous solution of a silver salt, such as silver nitrate, and an aqueous solu~ion of a water-soluble halide, for example, an alkali metal halide, such as potas~ium bromide, into a rapidly agitated aqueous solu-.. ..
. r ~', ' ' ' , 1:.. ~ ' ' ' ;

, ~

tion of a silver halide peptizer, preferably gelatin, a gelatin derivative or some other protein peptizer. Suit-able methods for preparing photographic silver halide emulsions having the required uniform particle size are disclosed in an article entitled "Ia: Properties of Photographic Emulsion Grains"~ by Klein and Moisar, The Journal of Photographic Science, Volume 12, 1964, pages 242 through 251; an article entitled "The Spectral Sensi-tization of Silver Bromide Emulsions on Different Crystallographic Faces", by Markocki, The Journal of Photogra~hic Science, Volume 13, 1965, pages 85 through 89; an article entitled "Studies on Silver Bromide Sols, Part I. The Formation and Aging of Monodispersed Silver Bromide Sols", by Ottewill and Woodbridge, The Journal of 15 Photographic Science, Volume 13, 1965, pages 98 through 103; and an article entitled '!Studies on Silver Bromide Sols, Part II. The Effect of Additives on the Sol Parti-cles", by Ottewill and Woodbridge, The Journal of Photo-graphic Science, Volume 13, 1965, pages 104 through 107.
Where internal latent image sites have been formed through internal chemical sensitization or the use of metal dopants, the surface of the silver halide grains can be sensitized to a level below that which will produce substantial density in a surface developer -- that is, less than 0.4 when coated, exposed and surface developed as described above. The silver halide grains are pre-ferably predominantly silver bromide grains chemically surface sensitized to a level which would provide a maximum density of at least 0.5 using undoped silver halide grains of the same size and halide composition when coated, exposed and developed as described above.
Surface chemical sensitization can be undertaken using techniques such as those disclosed by Sheppard, Waller et al, McVeigh or Dunn, cited above. The silver halide grains can also be surface sensitized with salts of the noble metals, such as ruthenium, palladium and .
':
.~ . , ,d ' ' ,` ': ` ' ''~. '' :` ' : ~ ' ~:~2(;~3~

platinum. Representati~e compounds are ammonium chloro-palladate, potassium chloroplatinate and sodium chloro-palladite, which are used ~or sensitizing in amounts below that which produces any substantial fog inhibition, as described in Smith and Trivelli, U.S. Patent 2,448,060, issued August 31, 1948, and as antifoggants in higher amounts, as described in Trivelli and Smith, U.S. Patent 2,566,245, issued August 28, 1951, and U.S. Patent 2,566,263, issued August 28, 1951. ~he silver halide grains can also be chemically sensitized with reducing agents, such as stannous salts (Carroll, U.S. Patent 2,487~850, issued November 15, 1949), polyamines, such as diethylene triamine ~Lowe et al, U.S. Patent 2,518,698, issued August 15, 1960), polyamines, such as spermine ~
15 (Lowe et al, U.S. Patent 2,521,925, issued September 12, :~-1950), or bis(~-aminoethyl)sulfide and its water-soluble ; salts (Lowe et al, U.S. Patent 2,521,926, issued September 12~ 1950).
The photographic silver halide emulsion layers 20 and other layers of the photographic elements can contain various colloids alone or in combination as vehicles.
Suitable hydrophilic materials include both naturally-occurring substances such as proteins, protein deriva-tives, cellulose derivatives -- e.g., cellulose esters, `~
: 25 gelatin -- e.g., alkali-treated gelatin (cattle bone or hide gelatin) or acid-treated gelatin (pigskin gelatin), gelatin derivatives -- e.g., acetylated gelatin, phthalat-ed gelatin and the like, poiysaccharides such as dextran, gum arabic, zein, casein, pectin, collagen derivatives, :3 collodion, agar-agar, arrowroot, albumin and the like, as described in Yutzy et al, U.S. Patents 23614,928 and '929; Lowe et al, U.S. Patents 2,691,582, 2,614,930 and '931, 2,327,808 and 2,448,534; Gates et al, U.S. Patents 2,787,545 and 2,956,880; Himmelmann et al, U.S. Patent 35 3,061,436; Farrell et al, U.S. Patent 2,816,027; Ryan, U~S.
Patents 3,1329945, 3,138,461 and 3,186,846; Dersch et al, U.K. Patent 1,167,159 and U.S. Patents 2,960,405 and 3,436,220; Geary, U.S. Patent 3,486,896; Gazzard, U.K. Patent :
.

,. ~ . . .

- 18 _ 793,549; Gates et al, U.S. Patents 2,992,213, 3,157,506, 3,184,312 and 3,539,353; Miller et al, U.S. Patent 3,227,571;
Boyer et al, U.S. Patent 3,532,502; Malan, U.S. Patent 3,551,151; Lohmer et al, U.S. Patent 4,018,609; Luciani et al, U.K. Patent 1,186,790; U.K. Patent 1,489,080; and Hori et al, Belgian Patent 856,631, U.K. Patent 1,490,644, U.K. Patent 1,483,551; Arase et al, U.K. Patent 1,459,906;
Salo, U.S. Patents 2,110,491 and 2,311,086; Fallesen, U.S.
Patent 2,343,650; Yutzy, U.S. Patent 2,322,085; Lowe, U.S.
Patent 2,563,791; Talbot et al, U.S. Patent 2,725,293;
Hilborn, U.S. Patent 2,748,022; DePauw et al, U.S. Patent 2,956,883; Ritchie, U.K. Patent 2,095; DeStubner, U.S.
Patent 1,752,069; Sheppard et al, U.S. Patent 2,1273573;
Lierg, U.S. Patent 2,256,720; ~Jaspar, U.S. Patent 2,361,536;
Farmer, U.K. Patent 15,727; Stevens, U.K. Patent 1,062,116;
and Yamamoto et al, U.S. Patent 3,923,517.
Photographic emulsion layers and other layers of photographic elements, such as overcoat layers, interlayers and subbing layers, as well as receiving layers in image-transfer elements~ can also contain alone or in combinationwith hydrophilic water-permeable colloids as vehicles or vehicle extenders (e.g., in the form cr latices), synthetic polymeric peptizers, carriers and/or binders such as poly-(vinyl lactams), acrylamide polymers, polyvinyl alcohol and its derivatives, polyvinyl acetals, polymers of alkyl and sulfoalkyl acrylates and methacrylates, hydrolyzed polyvinyl acetates, polyamides, polyvinyl pyridine, acrylic acid polymers, maleic anhydride copolymers, polyalkylene oxides, methacrylamide copolymers, polyvinyl oxazolidinones, maleic acid copolymers, vinylamine copolymers, methacrylic acid copolymers, acryloyloxyalkylsulfonic acid copolymers, sulfo-alkylacrylamide copolymers, polyalkyleneimine copolymers, polyamines, N,N-dialkylaminoalkyl acrylates, vinyl imidazole copolymers, vinyl sulfide copolymers, halo~enated styrene polymers, amlneacrylamide polymers, polypeptides and the like, as described in Hollister et al, U.S. Patents 3,679,425, 3,706,564 and 3,813,251; Lowe, U.S. Patents 2,253,078, 2,276,322 and '323, 2,281,703, 2,311,058 and 2,414,207;

~, , , Lowe et al, U.S. Patents 2,484,456, 2,541,474 and 2,632,704;
Perry et al, U.S. Patent 3~425,836; Smith et al, U.S. Patents 3,415,653 and 3,615,624; Smith, U.S. Patent 3,488,708;
~hiteley et al, U.S. Patents 3,392,025 and 3g511~818;
5 Fitzgerald~ U.S. Patents 3,681,o79, 3,721,565, 3,852,073, 3,861,918 and 3,925,o83; Fitzgerald et al, U.S. Patent 3,879,205; Nottorf, U.S. Patent 3,142,568; Houck et al, U.S. Patents 3,062,674 and 3,220,844; Dunn et al, U.S. Patent 2,882,161; Schupp, U.S. Patent 2,579,016; Weaver, U.S. Patent lo 2,829,053; Alles et al, U.S. Patent 2,698,240; Priest et al, U.S. Patent 3,oo3,879; Merrill et al, U.S. Patent 3,419,397;
Stonham, U.S. Patent 3,284,207; ~ohmer et al, U.S. Patent 3,167,430; Williams, U.S. Patent 2,957,767; Dawson et al, U.S. Patent 2,893~867; Smith et al, U.S. Patents 2,860,986 and 2,904,539; Ponticello et al, U.S. Patents 3,929,482 and 3,860~428; Ponticello, U.S. Patent 3,939,130; Dykstra, U.S.
Patent 3,411,911; Dykstra et al, Canadian Patent 774,054;
Ream et al, U.S. Patent 3,287,289; Smith, U.K. Patent 1,466,600; Stevens, U.K. Patent 1,062,116; Fordyce, U.S.
Patent 2,211,323; Martinez, U.S. Patent 2,284,877; Watkins, U.S. Patent 2,420,455; Jones, U.S. Patent 2,533,166; Bolton, U.S. Patent 2,495,918; Crraves, U.S. Patent 2,289,775; Yackel, U.S. Patent 2,565,418; Unruh et al, U.S. Patents 2,865,893 and 2,875,059; Rees et al, U.S. Patent 3,536,491; Broadhead et al, U.K. Patent 1,348,815; Taylor et al, U.S. Patent 3,479,186; Merrill et al, U.S. Patent 3,520,857; Bacon e~ al, U.S. Patent 3,690,888; Bowman, U.S. Patent 3,748,143, Dickinson et al, U.K. Patents 808,227 and ~228; Wood, U.K.
Patent 822,192; and Iguchi et al, U.K. Patent 1,398,055.
The layers of the photographic elements can be coated on a variety of supports. Typical photographic supports include polymeric film, wood fiber -- e.g., paper, metallic sheet and foil, glass and ceramic supporting elements provided with one or more subbing layers to enhance 35 the adhesive, antistatic, dimensional, abrasive, hardness, frictional~ antihalation and/or other properties of the support surface.

, ;, _ 20 _ Typical of useful polymeric film supports are films of cellulose nitrate and cellulose esters, such as cellulose triacetate and diacetate, polystyrene, polyamides, homo- and co-polymers of vinyl chloride, poly(vinyl acetal), polycarbonate, homo- and co-polymers of olefins, such as polyethylene and polypropylene, and polyesters of dibasic aromatic carboxylic acids with divalent alcohols, such as poly(ethy~ene terephthalate).
Typical of useful paper supports are those which are partially acetylated or coated with baryta and/or a polyolefin, particularly a polymer of an ~-olefin containing 2 to 10 carbon atoms, such as polyethylene, polypropylene, copolymers of ethylene and propylene and the like.
Polyolefins, such as polyethylene, polypropylene 15 and polyallomers -- e.g., copolymers of ethylene with propyl-ene, as illustrated by Hagemeyer et al, U.S. Patent 3,478,128, are preferably employed as resin coatings over paper, as lllustrated by Crawford et al, U.S. Patent 3,411,908, and Joseph et al, U.S. Patent 3,630,740, over polystyrene and :20 polyester film supports, as illustrated by Crawford et al, U.S. Patent 3,630,742a or can be employed as unitary flex~ble reflection supports, as illustrated by Venor et al, U.S.
Patent 3,973,963.
;Preferred cellulose ester supports are cellulose 25 triacetate supports, as illustrated by Fordyce et al, U.S.
Patents 2,492,977, '978 and 2,739,069, as well as mixed cellulose ester supports, such as cellulose acetate propionate and cellulose acetate butyrate, as illustrated by Fordyce et al, U.S. Patent 2,739,070.
Preferred polyester film supports are comprised of linear polyester, such as illustrated by Alles et al, U.S. Patent 2,627,088; Wellman, U.S. Patent 2,720,503;
Alles, U.S. Patent 2,779,684; and Kibler et al, U.S. Patent 2,901,466. Polyester films can be formed by varied tech-;35 niques, as illustrated by Alles, cited above, Czerkas et al, U.S. Patent 3,663,683 and Williams et al, U.S. Patent : 3,504,075, and modified for use as photographic film supports, as illustrated by Van Stappen, U.S. Patent 3,227,576; ~adeau ~, 3~ :

et al, U.S. Patent 3,501,301; Reedy et al, U.S. Patent 3,589,905, Babbitt et al, U.S. Patent 3,850,640; Bailey et al, U.S. Patent 3,888,678; ~unter, U~S. Patent 3,904,420;
and Mallinson et al, U.S. Patent 3,928,6~7.
The photographic elements can employ supports which are resistant to dimensional change at elevated temperatures. Such supports can be comprised of linear condensation polymers which have glass transition tempera-tures above about 190C, preferably 220C, such as poly-carbonates, polycarboxylic esters, polyamides, polysulfon-amides, polyethers, polyimides, polysulfonates and copolymer variants, as illustrated by Hamb, ~J.S. Patents 3,634,089 and 3,772,405; ~amb et al, U.S. Patents 3,725,070 and 3,793,249;
Wilson, Research Disclosure, ~olume 118, February 1974, 15 Item 11833, and Volume 120, April 1974, Item 120~6; Conklin et al, Research Disclosure, Volume 120, April 1974, Item 12012; Product Licensing Index, ~olume 92, December 1971, Items 9205 and 9207; Research Disclosure~ ~olume 101, September 1972, Items 10119 and 10148; Research Disclosure, :20 ~olume 106, February 1973, Item 10613; Research ~isclosure Volume 117, January 1974, Item 11709; and Research D
closure, Volume 134, June 1975, Item 13455. Both Research ;;
Disclosure and Product Licensing Index are published by Industrial Opportunities, Ltd., Homewell, Havant, Hamp-25 shire, P09 lEF, United Kingdorn.
The 3,3-disubstituted arylhydrazinophenylthiourea nucleating agents of this invention can be employed in any desired concentration that will permit a degree of selec-tivity in developing imagewise silver halide grains capable of forming an internal latent image, which grains have not been imagewise exposed, as compared to silver halide grains containing an internal latent image formed by imagewise exposure.
In a preferred form of this invention, the 3,3-35 disubstituted arylhydrazinophenylthiourea nucleatingagents are adsorbed to the surface of the internal latent image silver halide grains and ernployed in concentrations ranging from 0.1 to 500 mg of adsorbed nucleating agent per mole o~ silver. Preferably, 1 to 100 mg of adsorbed nucleating agent per mole of silver is employed. Optimum concentrations can, of course, var~ somewhat from one application to another. ~here the 3,3-disubstituted arylhydrazinophenylthiourea nucleating agent is to be adsorbed to the surface of the silver halide grains, it can be adsorbed using the procedures well known to those skilled in the art for adsorbing sensitizing dyes, such as cyanine and merocyanine dyes, to the surface of silver 10 halide grains.
A simple exposure and developrnent process can be used to form a direct-positive image. In one embodiment, a photographic element comprising at least one layer of a silver halide emulsion as described above can be imagewise 15 exposed and then developed in a silver halide surface developer.
It is understood that the term "surface devel-oper" encompasses those developers whlch will revea~ the surface latent image on a silver halide grain, but will 20 not reveal substantial internal latent image in an internal image-forming emulsion, and under the conditions generally used develop a surface-sensitive silver halide emulsion.
The surface developers can generally utilize any of the silver halide developing agents or reducing agents, but 25 the developing bath or composition is generally substan-tially free of a silver halide solvent (such as water-soluble thiocyanates, water-soluble thioethers, thiosul-fates, ammonia and the like) which will disrupt or dissolve the graîn to reveal substantial internal image. Low 3 amounts of excess halide are sometimes desirable in the developer or incorporated in the emulsion as halide-releasing compounds, but high amounts of iodide or iodide-releasing compounds are generally avoided to prevent substantial disruption of the grain. Typical silver 35 halide developing agents which can be used in the devel-oping composîtions of this invention include hydroquinones, catechols, aminophenols, 3-pyrazolidones, ascorbic acid and its derivatives, reductones, phenylenediamines and the ;

. .
. . : .`

like, or combinations thereof. Illustrative of useful sur face developers are those disclosed in Ives U.S. Patent 2,563,785, Evans U.S. Patent 3,761S276, Knott et al U.S.
Patent 2,456,953 and Juoy U.S. Patent 3,511,662.
Where the developing agents are initially entirely incorporated in the photographic elements, the remaining - components (e.g., water, activators to ad~ust pH, preser vatives, etc.) normally present in surface developers constitute what is commonly referred to as an activator solution. Except for the omission of the developing agent, activator solutions are identical to developer solutions in composition and are employed identically with incor-porated developing agent photographic elements. Subsequent references to developing compositions are inclusive of both 15 developer and activator solutions. ~-Photographic elements containing monosubstituted acylhydrazinophenylthioureas have been employed in combina-tion with developing compositlons having a pH at or above 13.5. At lower pH levels the nucleating activity of mono-substituted acylhydrazinophenylthioureas is significantlydiminished. It is a distinct advantage of the present invention that the 3,3-disubstituted acylhydrazinophenyl-thioureas retain to a relatively high degree their nucleat-ing activity when employed with developing compositions at p~ levels down to and below 12Ø In addition to being useful at higher pH levels conventionally employed with monosubstituted acylhydrazinophenylthioureas, typically in the range of from 13.5 to 13.9, the 3,3-disubstituted acylhydrazinophenylthioureas are useful at pH levels as low 3 as 11.8 andg depending upon the specific form of the photo-graphic element employed, even lower. It is frequently desirable to lower developing composition pH levels to reduce the potential hazard which the higher pH levels entail if the developing compositions are carelessly or otherwise improperly handledu For such applications, it is specifically preferred to employ developing composi-tions in the lower pH ranges, of from about 12.0 to 13.0, in processing photographic elements according to this .

.:

invention containing 3,3-disubstituted acylphenyl-hydrazinophenylthioureas.
The developing compositions used in the pro-cess of this invention can contain certain antifoggants and development restrainers, or, optionally, they can be incorporated in layers of the photographic element.
For example, in some applications, improved results can be obtained when the direct-positive emulsions are pro-cessed in the presence of certain antifoggants, as dis-closed in Stauffer U.S. Patent 2,497~917.
Typical useful antifoggants include benzotria-zoles, such as, benzotriazole, 5-methylbenzotriazole, 5-ethylbenzotriazole and the like, benzimidazoles, such as, 5-nitrobenzimidazole and the like, benzothiazoles, such as, 5-nitrobenzothiazole, 5-methylbenzothiazole and the like, heterocyclic thiones, such as, l-methyl-2-tetrazoline-5-thione and the like, triazines, such as, 2,4-dimethylaminG 6-chloro-5-triazine and the like, benzoxazoles, such as, ethylbenzoxazole and the like, and pyrroles, such as, 2,5-dimethylpyrrole and the like.
In certain embodiments, good results are ob-tained when the elements are processed in the presence of high levels of ~he antifoggants mentioned above.
When antifoggants such as benzotriazoles are used, good results can be obtained when the processing solution contains up to 5 grams per liter and preferably 1 to 3 grams per liter; when they are in orporated in the pho-tographic element, concentrations of rom 1,000 mg per mole of Ag and preferably concentrations o~ 100 to 500 mg per mole of Ag are employed.
The essential features of the 3,3-disubstituted arylhydrazinophenylthiourea nucleating agents of this invention and the silver halide emulsions and photographic elements in which they are incorporated, as well AS pro-cedures for their use and processing, are described above.It is appreclated that, in preferred photographic appli-cations, the emulsions and el.ements can contain addi~ional ~ '~

, . ~
, .
:: :

3 ~

features which are in themselves well known to those familiar with the photographic arts. Further, these applications can entail conventional modifications in the procedures described above. A variety of such features are disclosed in Research Disclosure, Volume 176, December 1978, Item 17643, the disclosure of which is herein incor-porated by reference, particularly Paragraph II, Emulsion ~ashing; Paragraph I~, Spectral Sensitization and Desensi-tization; Paragraph V, Brighteners; Paragraph VI, Anti-;lO foggants and Stabilizers; Paragraph VIII, Absorbing and Scattering Materials; Paragraph X, Hardeners; Paragraph XI, Coating Aids; Paragraph XII, Plasticizers and Lubricants; Paragraph XIII, Antistatic Layers; Paragraph XIV, Methods of Addition; Paragraph XV, Coating and ~-Drying Procedures; Paragraph XVI, Matting Agents; Para-graph ~VIII, Exposure; Paragraph XX, Developing Agents; and Paragraph XXI, Development Modifiers.
It is specifically contemplated to employ in com-bination with 3,3-disubstituted acylhydrazinophenyl-thiourea nucleating agents other conventional nucleatingagents. In a specifically preferred form one or a combina-tion of 3,3-disubstituted acylhydrazinophenylthiourea nuc-leating agents are employed at a concentration of up to about 200 mg per mole of silver, as indicated above, in combination with a conventional substituted hydrazine type nucleating agent which is present in a concentration of -from about 200 mg to about 2 grams per mole o~ silver.
Where the 3,3-disubstituted acylhydrazinophenylthiourea ;nucleating agent actually increases photographic speed, with increasing processing temperatures, using the nucleat-ing agent in combination with a conventional nucleating agent which decreases photographic speed with increasing processing temperatures, can result in a surprising degree of temperature insensitivity for the speed and develop-ability of the resulting photographic emulsion.
In one preferred form of this invention the 3~3-disubstituted acylhydrazinophenylthiourea nucleating agents , :, ': ' : ' .. . .

.~31~3~

are employed in combination with hydrazide and hydrazone nucleating agents of the type disclosed by Whitmore~ cited above. Such hydrazides and hydrazones are nitrogen-con-taining compounds having the formulas T-NH-NH-Tl and T-NH_N=T2 wherein T is an aryl radical and includin~ a substituted aryl radical; T is an acyl or a sulfonyl radical; and T2 is an alkylidene radical and including substituted alkyl-idene radicals. Typical aryl radicals for the substituent T have the formula r~-T3-; wherein T is an aryl radical (such as phenyl, l-naphthyl, 2-naphthyl, etc.) and M can be such substituents as hydrogen, hydroxy, amino, alkyl, alkylamino, arylamino, heterocyclic amino (amino contain-ing a heterocyclic moiety), alkoxy, aryloxy~ acyloxy, arylcarbonamido, alkylcarbonamido, heterocyclic carbonamido (carbonamido containing a heterocyclic moiety), arylsul-fonamido, alkylsulfonamido, and heterocyclic sulfonamido (sulfonamido containing a hyeterocyclic moiety). Typical acyl and sulfonyl radicals for the substitutent Tl have the formula O O
,. ..
~ -S-Y or -C-G
O
wherein Y can be such substituents as alkyl, aryl and heterocyclic radicals, G can represent a hydrogen atom or the same substituent as Y as well as radicals having the formula O

3 to form oxalyl radicals wherein A is an alkyl, aryl or a heterocyclic radical. Typical alkylidene radicals for the substituent T2 have the formula =C-D2 wherein D can be a hydrogen atom or such radicals as alkyl, aryl and hetero-cyclic radicals. Typical aryl substituents for the above-described hydrazides and hydrazones include phenyl,naphthyl, diphenyl, and the like. Typical heterocyclic substituents for the above-described hydrazides and hydra-zones include azoles, azines, furan, thiophene, quinoline, ~ ~ "

- .

:~L1~93~
.

pyrazole, and the like. Typical alkyl ~or alkylidene) substituents for the above-described hydrazides and hydra-zones ha~e 1 to 22 carbon atoms including methyl, ethyl, isopropyl, _-propyl, isobutyl~ _~butyl, t-butyl, amyl, _-octyl, n-decyl, n-dodecyl, n-octadecyl, _-eicosyl, -docosyl, etc.
Illustrative specific hydrazide (named as hydra-zine derivatives) and hydrazone nucleating agents useful in the practice of this invention include those set forth below in ~able II.
TABLE II ~:
H~ acetyl-2-phenylhydrazine H- 2 1-acetyl-2-(4 hydroxyphenyl)hydrazine H- 3 1-acetyl-2-(4-aminophenyl~hydrazine :~
: 15 H- 4 1-acetyl-2 (4-methylphenyl)hydrazine : H- 5 1-acetyl-2-(4-acetamidophenyl)hydrazine ~ H- 6 1-acetyl-2-(4-benzamidophenyl)hydrazine :~ H- 7 1-acetyl-2-(4-methoxyphenyl)hydrazine H- 8 1-acetyl-2-[4-(3-sulfobenzamido)phenyl~-hydrazine H- 9 1-acetyl-2-(4-phenylsulfamidophenyl)- :
~ hydrazine :~ H-10 1-acetyl-2-(4-methylsulfonamidophenyl)-~ hydrazine ; 25 H~ phenylsulfonyl-2-phenylhydrazine H-12 1-methylsulfonyl-2-phenylhydrazine H-13 1-benzoyl-2-phenylhydrazine H-14 1-benzoyl-2-(4-benzamidophenyl)hydrazine -: H-15 1-ethoxyalyl-2-phenylhydrazine ; 3 H-16 1-methoxysulfonyl-2-(3-phenylsulfonamido- ~ :~
phenyl)hydrazine H-17 1-(4-acetamidophenylsulfonyl)-2 naphthyl)hydrazine H-18 1-ethylsulfonyl-2-(4 diethylaminophenyl)-hydrazine H-19 1-phenylsulfonyl-2-(4-benzamido-2,5-di-ethoxyphenyl)hydrazine H-20 5-(1-carbo 2-phenylhydrazino)-1-phenyl-3-pyrazolidone ,., :

~ . . : . -- ~ , :

H-21 2-(1-carbo-2-phenylhydrazino)furan H-22 4~ carbo-2-phenylhydrazino)pyridine H-23 2-(1-carbo-2-phenylhydrazino)benzothia zole H-24 1-[2-(2,4-di-tert-amylphenoxy)-5-(3,5-disulfobenzamido)benzoyl]-2-phenyl-hydrazine H-25 1-acetyl-2-{4-[5-amino-2-(2,4-di-tert-pentyl-phenoxy)benzamido]phenyl}hydra-zine H-26 1-lauroyl-2-phenylhydrazine H-27 1-lauroyl-2-[4-(3-sulfobenzamido)-phenyl]hydrazine H-28 1-methylsul~onyl-2-(4-octadecylphenyl)-hydrazine H-29 l~octadecyloxalyl-2-phenylhydrazine H-30 1-octadecyloxalyl-2-~4-(3-sulfobenz-amido)phenyl]hydrazine H-31 1-lauroyl-2-[4-(~-methylsulfonamido-ethyl)phenyl]hydrazine H-32 1-[3-(2,4-di-tert-amyl-x-sulfophenoxy)-benzoyl]-2-phenylhydrazine H-33 5-{1-carbo-2-[4-(~-sulfostearamido)-phenyl[hydrazino}-l-phenyl-3-pyrazoli-done H-34 Formaldehyde phenylhydrazone H-35 Formaldehyde 4-(~-methylsulfonamido-~: ethyl)phenylhydrazone H-36 Mucochloric acid 4-(S-methYlsulfonamido-3 ethyl)phenylhydrazone H-37 Acetone 4-methylphenylhydrazone H-38 Benzaldehyde 4-(~-methylsulfonamido~
ethyl)phenylhydrazone H-39 Benzaldehyde 4-methoxyphenylhydrazone 35 H-40 Benzaldehyde 4-(3-sulfobenzamido)phenyl-~ hydrazone ; H-41 Formaldehyde 4-methylsulfonamidophenyl-hydrazone ....

: .. :

,~ :

H-42 Acetaldehyde 4-phenylsulfonamidophenyl-hydrazone H-43 _-tolualdehyde 4-diethylaminophenyl~
hydrazone 5 H-44 cinchoninaldehyde 4-acetamidophenyl-hydrazone H-45 2-furaldehyde 4-methylsulfonamido-1-naphthylhydrazone H-46 Nicotinaldehyde 4-(3-methylsulfamyl-benzamido)-2,5~diethoxyphenylhydrazone H-47 Hendecanal 4-(a-sulfostearamido)phenyl- ;
hydrazone H-48 3-octadecyloxybenzaldehyde phenyl-hydrazone ;
15 H-49 3-octadecyloxybenzaldehyde 4-(4-sulfo-benzamido)phenylhydrazone H-50 benzaldehyde 4-C5-(3,5-disulfo)-2-(2,4-di-tert-pentyl-phenoxy)benzamido]phenyl-hydrazone dipotassium salt 20 H-51 oxyguargum 4-(~-methylsulfonamidoethyl)-: phenylhydrazone H-52 1-phenylacetyl-2-phenylhydrazine : H-53 1-formyl-2-p-tolylhydrazine In another preferred form of this invention the 3,3-disubstituted acylhydrazinophenylthiourea nucleating agents are employed in combination with N-substituted cycloammonium salts of the type disclosed by Kurtz, Harbi-son, Heseltine and Lincoln, cited above. Generally, these compounds can be represented by the formula 3~ ____ z__ ___ N~CH-CH)j =C-E
xe (CH2)a E

wherein Z represents the atoms necessary to complete a hetero-cyclic nucleus containing a heterocyclic ring o~ 5 to 6 atoms including the quaternary nitrogen atom, with the . .
, ' ~3o-additional atoms of the heterocyclic ring being selected from carbon, nitrogen, oxygen, sulfur and selenium, ~ represents a positive integer of from 1 to 2, a represents a positive integer of from 2 to 6, xe represents an acid anion, E represents a member selected from (a) a formyl radical, (b) a radical having the formula ~C~
~ L2 wherein each of Ll and L2, when taken alone, represents a member selected from an alkoxy radical and an al~ylthio radical3 and Ll and L2, when taken together, represent the atoms necessary to complete a cyclic radical selected from cyclic oxyacetals and cyclic thioacetals having from 5 to 6 atoms in the heterocyclic acetal ring, and (c) a l-hydrazonoalkyl radical, and El represents either a hydrogen atom, an alkyl radi-cal, an aralkyl radical, an alkylthio radical or, an aryl radical such as phenyl or naphthyl, and including substi-tuted aryl radicals.
In certain preferred embodiments of this inven- -tion, the N-substituted cycloammonium quaternary salts are those which contain N~substituted alkyl radicals having the terminal carbon atom substituted with a hydrazono radical, an acyl radical such as a formyl radi-cal, an acetyl radical or a benzoyl radical, and those which have a dihydro~aromatic ring nucleus, such as, for example, a dihydropyridinium nucleus.
3 Illustrative specific N-substituted quaternary ammonium salt nucleating agents useful in the practice of this invention include those set forth below in Table III.
TABLE III 5 QAS- 1 3-(2-formylethyl)-Z~methylbenzothiazo-lium salt QAS 2 3~(2~formylethyl)-2~methylnaphtho-~2,3-d]thiazolium salt 3~

QAS- 3 3-(2-acetylethyl)-2-phenoxymethyl-benzo-thiazolium salt QAS- 4 3-(2-acetylethyl)-2-benzoselenazolium salt QAS- 5 1,2-dihydro-3-methyl-4-phenylpyrido-[2,1-b]benzothlazolium salt QAS- 6 1,2-dihydro-3-methyl-4-phenyLpyrido-[2,1-b]-5-phenylbenzoxazolium salt QAS- 7 1,2-dihydro~3,4-dimethylpyrido-[2,1-b]benzothiazolium salt QAS- 8 1,2-dihydro-3,4-diphenylpyrido-[2,1-b]benzothiazolium salt QAS- 9 1,2-dihydro-2-butyl-3-methyl-4-phenyl-pyrido~2,1-b]-5-carbethoxybenzothia-zolium salt QAS-10 1,2-dihydro-3-methyl-4-phenylpyrido-~- [2,1-b]-5-(N-methyl-N-phenylcarbamido)-benzothiazolium salt QAS 11 192-dihydro-3,4-dimethylpyrido[2,1-b]-5-(N-ethyl-N-octadecylcarbamido)benzo-~:~ thiazolium salt QAS-12 3-(3,3-di(ethylthio)pyrpyl]-2-methyl-.- benzothiazolium iodide QAS-13 1-(2-formylethyl)lepidinium bromide 25 QAS-14 3-[3,3-di(ethyl)propyl]-2-methylbenzo-~ thiazolium iodide QAS-15 3-(6,6-diethoxy-_-hexyl)-2-methylnaphtho-; ~2,1-d~thiazolium bromide ~. QAS-16 3-[2-(1,3-dioxan-2-yl)ethyl]-2-methyl-: 3 benzoselenazolium bromide QAS-17 3-~3-(1,3-dioxolan-2-yl)propyl]-2-phenylbenzimidazolium perchlorate QAS-18 5-chloro-3-(2-formylethyl)-2-methyl-benzothiazolium bromide 35 QAs-l9 3-(3,3-di(ethylthio)propyl~-2-methyl-benzothiazolium iodide QAS-20 3-(6,6-diethoxy-n-hexyl)-2-methyl-naphtho[2,1-d]thiazolium bromide -.
, QAS-21 3-[2-(1,3-dithiolan-2-yl)ethyl]-2-methylbenzo thiazolium iodide QAS-22 3-(3,3-diethoxypropyl)-2-ethylthionaphtho-[2,3-d~thiazolium methylsulfate QAS-23 3-[3-(1,3-dioxolan-2-yl)propyl]-1-ethyl-2-phenyl-benzimidazolium perchlorate It is also speciically contemplated to employ the 3,3~disubstituted acylhydrazinophenylthiourea nucleat-ing agents of ~his patent application in combination with the monosubstituted acylhydrazinophenylthiourea nucleating agents of Leone et 81 U.S. Patent 4,030,925, cited above, and N-(acylhydrazinophenyl)thioamides of Leone et al U.S.
Patent 4,080,207. It is further recognized that adducts of a thioamine and glutaraldehyde or acrylic aldehyde, such as those described in Plakunov et al U.S. Patent 3,708,302 and Amering U.S. Patent 3,869,286, are capable of acting as nucleating gents and are useful in combina-tion with the nucleating agents of this invention.
The silver halide emulsions can be spectrally sensitized with cyanine, merocyanine, and o~her poly-methine dyes and supersensitizing combinations thereof well known in the art. Spectral sensitizers în conven-tional surface-sensitive emulsions are comparably effec-tive in the emulsions of this invention. In general 3 they enhance nucleation. Nonionic, zwitterionic and anionic spectral sensitizers are preferred. Particularly efec-tive are carboxy-substituted merocyanine dyes of the thio-hydantoin type described by Stauffer et al U.S. Pa~ent 2,490,758.
Effective red sensitizers are the carbocyanines of formula (V) C=CH-C-CH- ~ ~ (X~ n-~
I G
Rl R2 wherein each of zl and Z2 represents the atoms necessary to form a benzothiazole, benzoselenazole, naphthothiazole, or ,~ '' .

3~;

naphthoselenazole, the benzothiazole and benzoselenazole being preferably 5 and/or 6-substituted with groups such as lower alkyl, lower alkoxy, chloro, bromo, fluoro, hydroxy, acylamino3 cyano and trifluoromethyl, G represents hydrogen and lower alkyl, preferably ethyl or methyl, each of Rl and R2 represents lower alkyl or hydroxy-(lower)alkyl, at least one of Rl and R2 being preferably acid-substituted~lower)alkyl, such as carboxyethyl, 0 sulfopropyl, sulfatoethyl, etc.~
represents an acid anion, and n is 1 or 2.
Particularly effective are certain supersensitiz-ing combinations of the above dyes with each other and with dyes or other adsorbed organic compounds ha~ing polarographic oxidation potentials (Eox) of about 0.3 to 0.9 volt. r~any such combinations are described in U.S.
Patents 2~075,048; 2,313,922; 2,533,426; 2,704,714;
2,70LI,717; 2,688,545 and 3,672,898, and include, as well, the acid-substituted analogues thereof well known in the art.
Effective green sensitizers are cyanines and merocyanines of formulas (VI) and (VII) ~ (VI) z~ ~z2 25 C~C=CH-C=CH-C~ J (X ) n 1 R R
wherein eàch of zl and z2 represents the atoms necessary to form benzoxazole and benzimidazole nuclei, benzimidazole being substituted in the 3~position by lower alkyl or aryl, and preferably in the 5- and/or 6-positions with groups selected from fluoro, chloro, bromo, lower alkyl, cyano, acylamino and trifluoromethyl, and the benzoxazole ring preferably substituted in the 5- or 6-posltions with lower alkyl, lower alkoxy, phenyl, fluoro, chloro, and bromo, Z3 represents the atoms necessary to form benzo-thiazole, benzoselenazole, naphthothiazole, naphthoselena-zole, or 2-quinoline, Z4 represents the atoms necessary to form 2-quinol-ine, G represents lower alkyl and, if at least one of zand z2 forms benzimidazole, hydrogen, each of Rl, R2, R3 and R4 represents lower alkyl or hydroxy(lower)alkyl, at least one of Rl and R2 and of R3 and R4 being preferably acid~substituted(lower)alkyl such as carboxyethyl, sulfopropyl, sulfatoethyl, etc,, X represents an acid anion, and : n is 1 or 2.
Particularly effective are certain supersensitiz- ~`
ing combinations o~ the above dyes, such as those described in U.S. Patents 3,397,o60; 2,688,545; 2,701,198 and 2,973,264, and their acid-substituted analogues well known ~; in the art.
Effective blue sensitizers are simple cyanines and merocyanines of formulas (VIII) and (IX) (VIII) z1 ~ zz -CH-C~ ~ (X )n_ ~:~ 25 (IX) Il;C-Q
R-N- (CH=CH-) mC=C~ ~N-R
~, wherein 3 each of zl and z2 represents the atoms necessary to form benzothiazo~e, benzoselenazole, naphthothiazole and naphthoselenazole nuclei which may be substituted with groups such as chloro, methyl or methoxy, chloro, bromo, lower alkyl or lower alkoxy, Z3 represents benzothiazole, benzoselenazole which may be substituted as in Z and Z , and pyridine nuclei, Ql and Q2 together represent the atoms necessary to complete a rhodanine, 2-thio-2?4-oxazolidine-dione or 2-':
`"

.
~ . ! ~ . , ~ ,, ' ' ' ':

9~

thiohydantoin ring, the latter having a second nitrogen atom with a substituent R5, m represents O or 1, each of Rl, R2 and R3 represents lower alkyl or 5 hydroxy(lower)alkyl, at least one of` Rl and R2 being preferably acid-substituted(lower)alkyl such as carboxy-ethyl, sulfopropyl and sulfatoethyl, etc., R4 and R5 represent lower alkyl and hydroxy(lower)-alkyl, and R4 additionally can represent carboxyalkyl and sulfoalkyl, X is an acid anion, and n is 1 or 2. . .
The photographic elements are prefera~ly color photographic elements which ~orm dye images through the 15 selective destruction, formation or physical removal of dyes.
The photographic elements can produce dye images through the selective destruction of dyes or dye pre-cursors, such as silver-dye-bleach processes, as illus-20 trated by A. Meyer, The Journal of Photographic Science,Volume 13, 1965, pages 90 through 97. Bleachable azo, azoxy, xanthene, azine, phenylmethane, nitroso complex~
indigo, quinone, nitro-substituted, phthalocyanine and formazan dyes, as illustrated by Stauner et al, U.S.
25 Patent 3,754,923; Piller et al, U.S. Patent 3,749,576;
Yoshida et al, U.S. Patent 3,738,839; Froelich et al, U.S.
Patent 3,716,368; Piller, U.S. Patent 3,655,388; Williams et al, U.S. Patent 3,642,482; Gilman, U.S. Patent 3,567,448; Loeffel, U.S. Patent 3,443,953; Anderau, U.S.
30 Patents 3,443,952 and 3,211,556; Mory et al, U.S. Patents 3,202,511 and 3,178,291; and Anderau et al, U.S. Patents 3,178,285 and 3,178,29Q, as well as their hydrazo, diazonium and tetrazolium precursors : ~ , 9;~6;

and leuco and shifted derivatives, as illustrated by U.K.
Patents 923,265, 999,996 and 1,042,300; Pelz et al, U.S.
Patent 3,684,513; Watanabe et al, U.S. Patent 3,615,493;
Wilson et al, U.S. Patent 3,503,741; Boes et al, U.S.
5 Patent 3,340,059; Gompf et al, U.S. Patent 3,493,372; and Puschel et al, U.S. Patent 3,561,970, can be employed.
The photographic elements can produce dye images through the selective formation of dyes, such as by reacting (coupling) a color-developing agent (e.g., a primary aro-matic amine) in its oxidized form with a dye-forming coupler.
The dye-~orming couplers can be incorporated in the photo-graphic elements, as illustrated by Schneider et al, Die Chemie, Volume 57, 1944, page 113; Mannes et al, U.S.
Patent 2,304,940; Martinez, U.S. Patent 2,269,158; Jelley . :~ 15 et al, U.S. Patent 2,322,027; Frolich et al, U.S. Patent `~ 2,376,679; Fierke et al, U.S. Patent 2,801,171; Smith, ~; U.S. Patent 3,748,141; Tong, U~S. Patent 2,772,163; Thirtle ~; et al, U.S. Patent 2,835`,579; Sawdey et al, U.S. Patent ~: 2,533,514; Peterson~ U.S. Patent 2,353,754; Seidel, U.S.
:~: 20 Patent 3,409,435; and Chen, ~esearch Disclosure, Volume 159, July 1977, Item 15930.
In one form, the dye-forming couplers are chosen to form subtractive primary (i.e., yellow, magenta and cyan~ image dyes and are n~ndiffusible, colorless couplers, "~ 25 such as two- and four-equivalent couplers of the open chain ; ketomethylene, pyrazolone, pyrazolotriazole, pyrazolobenz- ;~-imidazole, phenol and naphthol type hydrophobically ballasted ~; for incorporation in high-boiling organic (coupler) solvents.
Such couplers are illustrated by Salminen et al, U.S. Patents 2,423,730; 2,772,162; 2,895,826; 2,710,803; 2,407,207;
: 3,737,316; and 2,367,531; Loria et al, U.S. Patents `~ 2,772,161; 2,600,788; 3,006,759; 3,214,437; and 3,253,924;
McCrossen et al, U.S. Patent 2,875,057; Bush et al, U.S.
Patent 2,908,573; Gledhill et al~ U.S. Patent 3,034,892;
35 Weissberger et al, U.S. Patents 2,474,293; 2,407,210;
3,062,653; 3,265,506; and 3,384,657; Porter et al, U.S.
Patent 2,343,703; Greenhalgh et al, U.S. Patent 3,127,269;
Feniak et al, U.S. Patents 2,865,748; 2,933,391; and .
.

, 2,865,751; Bailey et al, U.S. Patent 3,725,067; Beavers et al, U.S~ Patent 3,758,308; Lau, U.S. Patent 3,779,763; Fernandez, U.S. Patent 3,785,829, U.K. Patent 969,921; U.K. Patent 1,241,069; U.K. Patent 1,011,940; Vanden ~ynde et al, U.S.
5 Patent 3,762,921; Beavers, U.S. Patent 2,983,608; Loria, U.S. Patents 3,311,476; 3,408,194; 3,458,315; 3,447,928; and 3,476,563; Cressman et al, U.S. Patent 3,419,390; Young, :~
U.S. Patent 3,419,391; Lestina, U.S. Patent 3,519,429;
U.K. Patent 975,923; U.K. Patent 1,111,554; Jaeken, U.S.
Patent 3,222,176 and Canadian Patent 726,651; Schulte et al, U.K. Patent 1,248,924; and Whitmore et al, U.S. Patent 3,227,550. ~ :~
The photographic elements can incorporate alkali- ~:
soluble ballasted couplers, as illustrated by Froelich et al ; 15 and Tong, cited abo~e. The photographic elements can be adapted to form nondiffusible image dyes using d~le-forming couplers in developers, as illustrated by U.K. Patent 478,984; Yager et al, U.S. Patent 3,113,864; Vittum et al, U.S. Patents 3?C02,836; 2,271,238; and 2,362,598; Schwan et al, U.S. Patent 2,950,970; Carroll et al, U.S. Patent : ~ 2,592,243; Porter et al, U.S. Patents 2,343,703; 2,376,380;
and 2,369,489; Spath, U.K. Patent 886,723 and U.S. Patent ~ 2,899,306; Tuite, U.S. Patent 3,152,896; and Mannes et al, :~ U.S. Patents 2, lI5,394; 2,252,718; and 2,108 ~ 602.
The:dye-forming couplers upon coupling can release photographically useful fragments, such as development ; ~ inhibitors or accelerators, bleach accelerators, developing : agents, silver halide solvents, toners, hardeners, fogging agents, antifoggants, competing couplers, chemical or spec-: 30 tral sensitizers and desensitizers. Development inhibitor-releasing (DIR) couplers are illustrated by Whitmore et al, U.S. Patent 3,148,062; 3arr et al, U.S. Patent 3,227,554;
Barr, U.S. Patent 3,733,201; Sawdey, U.S. Patent 3,617,291;
Groet et al, U.S. Patent 3,703,375; Abbott et al, U.S.
35 Paten~ 3,615,506; Weissberger et al, U.S. Patent 3,265,506;
Seymour, U.S. Patent 3,620,745; Marx et al, U.S. Patent 3,632,345; Mader et al, U.S. Patent 3,869,291; U.K. Patent 1,201,110; Oishi et al, U.S. Patent 3,642,485; Verbrugshe, :

: , , . , l~ZU~

U.K. Patent 1,236,767; Fu~iwhara et al, U.S. Patent 3,770,436; and Matsuo et al, U.S. Patent 3,808,945. DIR
compounds which do not form dye upon reaction with oxidized color-developing agents can be employed, as illustrated by Fujiwhara et al, German OLS 2,529,350 and U.S. Patents 3,928,041; 3,958,993; and 3,961,959; Odenwalder et al, German OLS 2,448,063; Tanaka et al, German 01S 2,610,546;
Kikuchi et al, U.S. Patent 4,049,455; and Credner et al, U.S. Patent 4,052,213. DIR compounds which oxidatively cleave can be employed, as illustrated by Porter et al, U.S. Patent 3,379,529; Green et al, U.S. Patent 3,043,690;
Barr, U.S. Patent 3,364,022; Duennebier et al, U.S. Patent 3,297,445; and Rees et al, U.S. Patent 3,287,129.
The photographic elements can incorporate colored dye-forming couplers, such as those employed to form inte-gral masks for negative color images, as illustrated by Hanson, U.S. Patent 2,449,966; Glass et al, U.S. Patent 2,521,908; Gledhill et al, U.S. Patent 3,034,892; Loria, U.S. Patent 3,476,563; Lestina, U.S. Patent 3,519,429;
Friedman, U.S. Patent 2,543,691; Puschel et al, U.S. Patent 3,028,238; Menzel et al, U.S. Patent 3,061,432; and Greenhalgh, U.K. Patent 1,035,959; and/or competing couplers, as illustrated by Murin et al, U.S. Patent 3,876,428;
Sakamoto et al, U.S. Patent 3,580,722; Puschel, U.S. Patent 2,998,314; Whitmore, U.S. Patent 2,808,329; Salminen, U.S.
Patent 2,742~832; and Weller et al, U.S. Patent 2,689,793.
` The photographic elements can produce dye images through the selective removal of dyes. Nega~ive or positive dye images can be produced by the immobilization or mobiliza-3 tion of incorporated color-providing substances as a function of exposure and development, as illustrated by U.K. Patents 1,456,413; 1,479,739; 1,475,265; and 1,471,752; Friedman, U.S. Patent 2~543g691; Whitmore, U.S. Patent 3,227,552;
Bloom et al, U.S. Patent 3,443,940; ~orse, U.S. Patent 3,549,364; Cook, U.S. Patent 3,620,730; Danhauser, U.S.
Patent 3,730,718; Staples, U.S. Patent 3,923,510; Oishi et al, U.S. Patent 4,052,214; and Fleckenstein et al, U.S.
Patent 4,o76,529.

" Q .1~

The photographic elements can contain antistain agents (i.e., oxidized developing agent scavengers) to prevent developing agents oxidized in one dye image layer unit from migrating to an ad~acent dye image layer unit.
Such antistain agents include ballasted or otherwise non-diffusing antioxidants, as illustrated by Weissberger et al, U.S. Patent 2~336~327; Loria et al, U.S. Patent 2~728~659; Vittum et al, U.S. Patent 2~360~290; Jelley et al, U.S. Patent 2~403~721; and Thirtle et al, U.S. Patent 2~701~197~ To avoid autooxidation the antistain agents can be employed in combination with other antioxidants, as illustrated by Knechel et al, U.S. Patent 3~700~453~
The photographic elements can include image dye stabilizers. Such image dye stabilizers are illustrated by U.K. Patent l~326388g; Lestina et al, U.S. Patents 3~432~300 and 3~698~909; Stern et al, U.S. Patent 3~574~627; Brannock et al, U.S. Patent 3~573~050; Arai et al, U.S. Patent 3 ~ 764 ~ 337; and Smith et al, U.S. Patent

4~042~394 ~
This invention is particularly useful with photographic elements used in image transfer processesor in image transfer film units.
Image transfer systems include colloid transfer systems, as illustrated by Yutzy et al, U.S. Patents 25 2~596~756 and 2~716~059; imbibition transfer systems, as illustrated by Minsk, U.S. Patent 2~882~156~ and color image transfer systems, as illustrated by Research Dis-closure, Volume 151~ November 1976~ Item 15162~ and Volume 123, July 1974 ~ Item 12331n 3 Color i~age transfer systems (including emulsion layers, receiving layers, timing layers, acid layers, processing compositions, supports and cover sheets) and the images they produce can be varied by choos~ng among a variety of features, combinations of which can be used together as desired.
Film units can be chosen which are either inte-grally laminated or separated during exposure, processing and/or viewing, as illustrated by Rogers, U.S. Patent ., . ~
.
.
- . .

---~o -2,983,606; Beavers et al, IJ.S. Patent 3,445,228; Whitmore, Canadian Patent 674,082; Friedman et al, U.S. Patent 3,3Q9,201; Land, U.S. Patents 2,543,181; 3,053,659;
3,415,644; 3~415,645; and 3,415,646; and Barr et al, U.K.
Patent 1,330,524.
A variety of approaches are known in the art for obtaining transferred dye images. Transferred dye images are obtained by altering the initial mobility of dye image providing compounds. ~In~tial mobility refers to the 10 mobility of the dye image providing compound when it is contacted by the processing solution. Initially mobile dye image providing compounds as coated do not migrate prior to contact with processing solution.) Dye image providing compounds are classified as 15 either positive-working or negative-working. Positive-working dye image providing compounds are those which produce a positive transferred dye image when employed in combination with a conventional, negative-working silver halide emulsion. Negative-worklng dye image providing 20 compounds are those which produce a negative transferred dye image when employed ln combination with conventional, negative-worklng silver halide emulsions. (The foregoing definitions assume the absence of special image reversing techniques~ such as those referred to in Research Disclosure, 25 Vol. 176, December 1978, Item 17643, paragraph XXIII~
When, as in the present invention, the silver halide emul-sions are direct-positive emulsions, positive-working dye image providilig compounds produce negative transferred dye ; images and negatlve-working dye image providing compounds 30 produce posltive transferred dye images. `
Image transfer systems, which include both the dye image provlding compounds and the silver halide emul-sions, are positlve-working when the transferred dye image is positive and negative working when the transferred dye 35 image is negative. When a retained dye image is formed, it is opposite in sense to the transferred dye 1mage.
A variety of dye image providing compounds are known and can be employed in the practice of this inven-tion. One approach is to employ ballasted dye-forming ., :

~ 6 (chromogenic) or non-dye-forming (nonchromogenic) couplers having a mobile dye attached at a coupling-off site. Upon coupling with an oxidized color developing agent, such ~s a ~ -phenylenediamine, the mobile dye is displaced so that it can transfer to a receiver. Such negative-working dye image providing compounds are illustrated by Whitmore et al U.S.
Patent 3 3 227,550; Whitmore U.S. Patent 3,227,552; and Fujihara et al U.K. Patent 1,445,797.
In a preferred image transfer system according to this invention employing negative-working dye image providing compounds, a cross-oxidizing developing agent (electron trans-fer agent) develops silver halide and then cross~oxidizes with a compound containing a dye linked through an oxidizable sul-fonamido group, such as a sulfonamidophenol, sulfonamido-aniline, sulfonamidoanilide, sulfonamidopyrazolobenzimidazole, sulfonamidoindole or sulfonamidopyrazole. Following cross-oxidation, hydrolytic deamidation cleaves the moblle dye wlth the sulfonamido group attached. Such systems are illustrated by Fleckenstein U.S. Patents 3,928,312 and 4,053,312, Fleckenstein et al U.S. Patent 4,076,529, Melzer et al U.K.
Patent 1~489,694, Deguchi German OLS 2,729,820, Koyama et al German QLS 2,613,005, Yetter et al German OLS 2,505,248, and Kestner et al Research Disclosure, Volume 151, November 1976, Item 15157. Also speciflcally contemplated are otherwise similar systems which employ an immobile, dye-releasing (a) hydroquinone, as illustrated by Gompf et al U.S. Paten~
3,698,897 and Anderson et al U.S. Patent 3,725,062, ~b~
para-phenylenediamine, as illustrated by Whitmore et al Canadian Patent 602,607, or (c) quaternary ammonium compound, as illustrated by Becker et al U.S. Patent 3,728,113.
Another specifically contemplated dye image transfer system which is employs negative-working dye image providing compounds reacts an oxidized electron transfer agent or, specifically, in certain forms, an oxidized ~ara-phenylenediamine with a ballasted phenolic coupler having a dye attached through a sulfonamido linkage. Ring , .
.
.: ..

closure to form a phenazine releases mobile dye. Such an imaging approach is illustrated by Bloom et al, U.S.
Patents 3,443,939 and 3,443,940.
In still another image transfer system employing negative-working dye image providing compounds, ballasted sulfonylamidrazones, sulfonylhydrazones or sulfonylcarbonyl-hydrazides can be reacted with oxidized para-phenylenediamine to release a mobile dye to be transferred, as illustrated by Puschel et al, U.S. Patents 3,628,952 and 3,844,785.
10 In an additional image transfer system, a hydrazide can be reacted with silver halide having a developable latent image site and thereafter decompose to release a mobile, transferable dye, as illustrated by Kohara et al, Bulletin Chemical Society of Japan, Volume 43, pages 2433 through 15 2437 and Lestina et al, ~esearch Disclosure, Volume 28, December 1974, Item 12832.
The foregoing systems all employ initially immobile negative-working dye image providing compounds containing a preformed dye which is split off during imaging. The 20 released dye is mobile and can be transferred to a receiver.
Positive-working dye image providing systems which split off mobile dyes from immobile initially present compounds are also known. For example, it is known that when silver halide is imagewise developed, the residual silver ions ~-25 associated with the undeveloped silver halide can react with a dye substituted ballasted thiazolidine to release a mobile dye imagewise, as illustrated by Cieciuch et al, U.S. Patent 3,719,489 and Rogers, U.S. Patent 3,443,941.
Preferred initially immobile positive-working 3 dye image providing compounds are those which release mobile dye by anchimeric displacement reactions. The compound in its initial form is hydrolyzed to its active form while silver halide development with an electron transfer agent is occurring. Cross-oxidation of the active dye-releasing compound by the oxidized electron transfer agent prevents hydrolytic cleaving of the dye moiety. Benzisoxazolone precursors of hydroxylamine dye-releasing compounds are illustrated by Hinshaw et al, U.K.

:

Patent 1,464,104 and Re earch Disclosure, Volume 144, April 1976, Item 14447. N-Hydroquinonyl carbamate dye image providing compounds are illustrated by Fields et al, U.S.
Patent 3,980,479. Image transfer systems are also known in which an immobile reducing agent ~electron donor~ is employed in combination with an immobile ballasted electron-accepting nucleophilic displacement ~BEND) compound which, on reduction, anchimerically displaces a diffusible dye.
Hydrolysis of the electron donor precursor to its active 10 form occurs simultaneously with silver halide development by an electron transfer agent. Cross-oxidation of the electron donor with the oxidized electron transfer agent prevents further reaction. Cross-oxidation of the BEND
compound with the residual, unoxidized electron donor then 15 occurs. Anchimeric displacement of mobile dye from the reduced BEND compound occurs as part of a ring cIosure reaction. A system of this type is illustrated by Chasman et al, U.S. Patent 4,139,379, issued February 13, 1979.
Other positive-working, initially immobile, 20 dye image providing compounds are illustrated by Rogers, U.S. Patent 3,185,567 and U.K. Patents 880,233 and ~234.
A variety o~ image transfer systems are known in which a positive-working dye image providing compound containing a dye or dye precursor is initially mobile, but 25 can be imagewise immobilized by reduction of developable silver halide directly or indirectly through an electron transfer agent. Systems which employ mobile dye developers, including shifted dye developers, are illustrated by Rogers, U.S. Patents 2,774~668 and 2,983,606; Idelson et 3 al, U.S. Patent 3,3-~79947; Dershowitz et al, U.S. Patent 3,230,085; Cieciuch et al, U.S. Patent 3,579~334; Yutzy, U.S. Patent 2,756~142; and Harbison, Defensive Publication T889,~17. In a variant form a dye moiety can be attached to an initially mobile coupler. Oxidation of a para-phenylenediamine or hydroquinone developing agent canresult in a reaction between the oxidized developing agent and the dye containing a coupler to form an immobile compound. Such systems are illustrated by Rogers, U.S.
Patents 2,774,668 and 3gO87,817; Greenhalgh et alg U.K.

..

f~

Patents 1,157,501 and ' 506; Puschel et al, U.S. Patent 33844~785; Stewart et al, U.S. Patent 3,653,896; Gehin et al, French Patent 2,287,711; and Research Disclosure, Volume 145, May 1976, Item 14521.
Other image transfer systems are known ln which varied immobili~.ation or transfer techniques are employed.
For example, a mobile developer-mordant can be imagewise immobilized by development of silver halide to imagewise immobilize an initially mob~le dye, as illustrated by Haas, 10 U.S. Patent 3,729,314. Silver halide development with an electron transfer agent can produce a free radical intermediate which causes an înitially mobile dye to polymerize in an imagewise manner, as illustrated by Pelz et al, U.S~ Patent 39585,030 and Oster, U.S. Patent 3,019,104. Tanning develop-15 ment of a gelatino-silver halide emulsion can render the gelatin impermeable to mobile dye and thereby imagewise restrain transfer of mobile dye, as illustrated by Land, U.S. Patent 2,543,181. Also gas bubbles generated by silver halide development can be used effectively to restrain 20 mobile dye transfer, as illustrated by Rogers, U.S. Patent 2?774,668. Electron transfer agent not exhausted by silver halide development can be transferred to a receiver to imagewise bleach a polymeric dye to a leuco form, as illus- .
~ trated by Rogers, U.S. Patent 3,015,561.
A number of image transfer systems employing posi-tive-working dye image providing compounds are known in which : dyes are not initially present~ but are formed by reactions occurring in the photographic element or receiver following exposure. For example, mobile coupler and color developing 30 agent can be lmagewlse reacted as a function of silver halide development to produce an immobile dye while residual developing agent and c.oupler are transferred to the receiver, and the developing agent is oxidized to form on coupling a transferred ~mmoblle dye image, as illustrated by Yutzy, U.S.
Patent 2,756,142; Greenhalgh et al, U.K. Patents 1,157,501-506; and Land, U.S. Patents 2,559,643; 2,647,049; 2,661,293;
2,6989244; and 2,698,798. In a variant form of this system, : the coupler can be reacted with a solubilized diazonium salt (or azosulfone precursor~ to form a diffusible azo dye .

.

3~ ~
--Ll 5--before transfer, as illustrated by Viro et al, U.S. Patent 3,837,852. In another variant form, a single, initially mobile coupler-developer compound can participate in inter-molecular self-coupling at the receiver to form an immobile

5 dye image, as illustrated by Simon, U.S. Patent 3,537,85a and Yoshiniobu, U.S. Patent 3,865,593. In still another variant form, a mobile amidrazone is present with the mobile coupler and reacts with it at the receiver to form an immobile dye image, as illustrated by Janssens et al, U.S. Patent lo 3,939,o35. Instead of using a mobile coupler, a mobile leuco dye can be employed. The leuco dye reacts with oxid-ized electron transfer agent to form an immobile product, while unreacted leuco dye is transferred to the receiver and oxidized to form a dye image, as illustrated by Lestina et al~
15 U.S. Patent 3,880,658; Cohler et al, U.S. Patent 2,892,71~;
Corley et al, U.S. Patent 2,992,105; and Rogers, U.S. Patents 2,909,430 and 3,0655074. ~obile quinone-heterocyclammonium salts can be immobilized as a function of silver halide development and residually transferred to a receiver where 2~ conversion to a cyanine or merocyanine dye occurs, as illus-trated by Bloom, U.S. Patents 3,537,851 and ' 852.
Image transfer systems employing negative_working dye image providing compounds are also known in which dyes are not initially present, but are formed by reactions occurr-25 ing in the photographic element or receiver following exposure.For example, a ballasted coupler can react with color develop-ing agent to form a mobile dye, as illustrated by Whitmore et al U.S. Patent 3,2273550, Whitmore U S. Patent 3,227,552, Bush et al U.S. Patent 3,7~1,827 and Viro et al U.S. Patent 30 4,o36,643. An immobile compound containing a coupler can react with oxidized ~ -phenylenediamine to release a mobile coupler whiGh can react with additional oxidized para-phenyl-enediamine before, during or after release to form a mobile dye, as illustrated by F~gueras et al U.S. Patent 3,734,726 and Janssens et al German OLS 2,317,134. In another form, a ballasted amidrazone reacts with an electron transfer agent as a function of silver halide development to release a mobile amidrazone which reacts with a coupler to form a dye at the receiver, as illustrated by Ohyama et al U.S. Patent 3~933,493.

molecular self-coupling at the receiver to form an immobile dye image, as illustrated by Simon, U.S. Patent 3,537,850 and Yoshiniobu, U.S. Patent 3,~65,593. In still another variant form, a mobile amidrazone is present with the mobile 5 coupler and reacts with it at the receiver to form an immobile dye image, as illustrated by Janssens et al, U.S. Patent 3,939,035. Instead of using a moblle coupler, a mobile leuco dye can be employed. The leuco dye reacts with oxid-ized electron transfer agent to form an immobile product, while unreacted leuco dye is transferred to the receiver and oxidized to form a dye image, as illustrated by Lestina et al, U.S. Patent 3,880,658; Cohler et al, U.S. Patent 2,892,710;
Corley et al, U.S. Patent 2,992~105; and Rogers, U.S. Patents 2,909,430 and 3,065,074. Mobile quinone-heterocyclammonium salts can be immobilized as a function of silver halide development and residually transferred to ~ receiver where conversion to a cyanine or merocyanine dye occurs9 as illus-trated by Bloom, U.S. Patents 3,537,851 and '852.
Negative-working image transfer systems are also 20 known in which dyes are not initially present, but are formed by reactions occurring in the photographic element or receiver following exposure. For example, a ballasted coupler can react with color developing agent to form a mobile dye, as illustrated by Whitmore et al, U.S. Patent ~ 25 3,227,550; Whitmore, U.S. Patent 3,227,552; Bush et al, : U.S. Patent 3,791,827; and ~iro et al, U.S. Patent 4,036,643.
An immobile compound containing a coupler can react with oxidized para-phenylenediamine to release a mobile coupler which can react with additional oxidized ~ phenylenediam~ne 3 before, during or after release to form a mobile dye, as illustrated by Figueras et al, U.S. Patent 3,734,726 and Janssens et al, German OLS 317,134. In another form, a ballasted amidrazone reacts with an electron transfer agent as a function of silver halide development to release a mobile amidrazone which reacts with a coupler to form a dye : at the receiver, as illustrated by Ohyama et al, U.S. Patent 3,933,493-~`
:

,, , . ~ - : :

An image to be viewed can be transferred from the image-forming layersO A retained image can be formed for viewing as a concurrently formed complement of ~he trans-ferred image. Positive transferred images and useful nega-tive retained images can be formed with the direct positivesilver halide emulsions of this invention when imaging chemistry is negative-working; and negative transferred images and positive retained images can be formed when the imaging chemistry is positive-working. Images retained in 1~ and transferred from the image-forming layers are illus-trated by U.K. Patent 1,456,413, Friedman U.S. Patent 2,543,691, Bloom et al U.S. Pa~ent 3,443,940, Staples U.S.
Patent 3,923,510, and Fleckenstein et al U.S. Patent 4,076,529.
Where mobile dyes are transferred to the receiver a mordant is commonly present in a dye image providing layer~
Mordants and mordant containing layers are described in the followi.ng references: Sprague et al U.S. Patent 2,S48,564, Weyer~s U.S. Patent 2,548,575, Carroll et al U.S. Patent 2,675,316, Yutzy et al U.S. Patent 2,713,305, Saunders et al U.S. Patent 2,756,149, Reynolds et al U.S. Patent 2,768,078, Gray et al U.S. Patent 2,839,401, Minsk U.S. P~tents 2,882,156 and 2,945~006, Whitmore et al U.S. Patent 2,940,849, Condax U.S. Patent 2,952,566, Mader et al U.S.
Patent 3,016,306, Minsk et al U.S. Patents 3,048,487 and 3,184,309, Bush U.S. Patent 3~271,147, Whitmore U.S. Patent 3,271,148, Jones et al U,S. Patent 3,~82,699, Wolf et al U.S. Patent 3,408,193, Cohen et al U.S. Patents 3,488,706, 3,557,066, 3,625,694, 3,709,690, 3,758,445, 3,788,855, 3,898,088, and 3,944,424, Cohen U.S. Paten~ 3,639,357, Taylor U.S. Patent 3,770,439, Campbell et al U.S. Patent 3,958,995; and Ponticello et al Research Disclosur~, Vol.
120, April 1974, Item 120459 as well as Campbell et al U.S.
Serial No. 906,289, filed May 15, 1978.
One-step processing can be employed, as illustrat-ed by U.K. Patent 1,471,752, Land U.S. Patent 2,543,181, Rogers U.S. Patent 2,983,606 ~pod processing), Land U.S.
Patent 3,485,628 (soak image former and laminate to receiver) and Land U.S. Patent 3,907,563 ~soak receiver and laminate to image-~orming element~ or multi-step processing can be employed, as illustrated by Yutzy U.S. Patent 2,756,1~2, Whitmore et al U.S. Patent 3,227,550 and Faul et al U.S.
Patent 3,998,637.
Preformed reflective layers can be employed, as illustrated by ~hitmore Canadian Patent 674,082, Beavers 10 U.S. Patent 3~445,228 Land U.S. Patents 2,543,181, 3,415,644, '645 and '646 and Barr et al U.~. Patent 1,330,524 or pro-cessing-formed reflective layers can be employed, as illus-trated by Land U.S. Patents 2,607,685 and 3,647,437, Rogers U.S. Patent 2,983,606 and Buckler U.S. Patent 3,661,585.
Generally, the image transfer film units in accordance with this invention comprise:
(1) a photographic element comprising a support having thereon at least one silver halide emulsion layer containing radiation-sensitive internal latent image silver halide grains 20 and a 3,3-disubstltuted arylhydrazinophenylthiourea nucleat-i~g agent, the emulsion layer preferably having in contact therewith an image dye-providing material, (2) an image-receiving layer, which can be located on a separate support and superposed or adapated to be superposed 25 on the photographic element or, preferably~ can be coated as a layer in the photographic element, (3) an alkaline processing composition, (4) means containing and adapted to release the alkaline ; processing composition into contact with the emulsion layer, 3 and (5) a silver halide developing agent located in at ~ least one of the photographic element and alkaline processing ; composition so that the processing composition and developing ~ agent, when brought together, form a silver halide surface ; 35 developer.
In highly preferred embodiments, the film units of this invention contain a support having thereon a layer con-taining a blue-sensitive emulsion and in contact therewith a yellow image dye-providing materlal, a red-sensitive silver ,,,"

`

: . : : :
: : .
- : ;, . ,- . :

~2vg3~
_L~g~
halide emulslon and in contact therewith a cyan image dye-providing material, and a green-sensitive emulsion and in contact therewith a magenta image dye-providing material, and preferably all of said image dye-providing materials are initially immobile image dye-providing materials.
The terms "diffusible" (or "mobile") and "immobile"
(or "nondiffusible"), as used herein, refer to compounds which are incorporated in the photographic element andg upon contact with an alkaline processing solution, are substan-tially diffusible or substantially immobile, respectively,in the hydrophilic colloid layers of a photographic element.
The term "irnage dye-providing material", as used herein, is understood to refer to those compounds which are employed to form dye images in photographic elements. These compounds include dye developers, shifted dyes, color coup-lers, oxichromic compounds, dye redox releasers, etc, as described above in connection with positive-working and negative-working image transfer systems.
In one preferred embodiment, the receiver layer is coated on the same support with the photosensitive silver halide emulsion layers, the support is preferably a trans parent support, an opaque layer is preferably positioned between the image-receiving layer and the photosensitive silver halide layer, and the alkaline processing composition 25 preferably contains an opacifying substance, such as carbon or a p~-indicator dye which is discharged into the film unit between a dimensionally stable support or cover sheet and the photosensitive element. `~
In certain embodiments, the cover sheet can be 3 superposed or is adapted to be superposed on the photosensi-tive element. The image-receiving layer can be located on the cover sheet so that it becomes an image-receiving element. In certain preferred embodiments where the image-receiving layer is located in the photosensitive 35 element, a neutralizing layer is located on the cover sheet.
Increases in DmaX can be obtained in color image transfer film units containing internally sulfur- and gold-sensitized emulsions of the type described by Evans, U.S.
Patent 3,761,276, and sulfonamidonaphthol redox dye-releasing .:~

compounds of the type described by Fleckenstein British Patent 1,405,662, by incorporation into the emulsion layers of a variety of chemical addenda generally recognized in the art as antifoggants or development inhibitors, as well as hydrolyzable precursors there of. Many of these compounds also provide improved stabilization o sensitometric properties of liquid emulsion and of the storage life of the coated emul-sion. The effects, shown in film units of the type described in Examples 40 ~hrough 42 of British Patent 1,405,662~ are in addition to the effect of 5-methyl-benzotriazole in the processing composition even when the latter is present in quantities as high as 4 grams per liter. Effective compounds in general are selected from the group consisting of (a) 1,2,3-triazoles, te-~razoles and benæotriazoles having an N-Rl group in the heterocyclic ring, wherein R' represents hydrogen or an alkali-hydrolyzable group, or ~b~ heterocyclic mercaptans or thiones and precursors thereof~ mostly having one of the formulas Z N or Z N-R' li ~ I
C-SR 2 C~S
wherein Z comprises the atoms necessary ~o complete an azole ring, and R~ represents, in addition to the groups speci:Eied above for Rl, a metal ion.
The compounds are generally employed at concentra-tions less than about 300 mg per mole of silver, each com pound having an optimum concentration above which development and/or nucleation are inhibited and DmaX decreases with increasing concentration. Specifically preferred antifog-gants and stabilizers, as well as other preferred color image transfer film unit and system features, are more specifically disclosed in Research Disclosure~ Volume 151, November 1976, Item 15162.
A more detalled description of useful image transfer film units and systems is con~ained in the patents rela~ing " ' ~

~:

~ 6 to image transfer cited above. A specific, preferrPd image-transfer film unit and image transfer system is that disclosed by Leone et al U.S. Patent 4,030,925, cited above.
The following examples illustrate the inven~ion.
S All temperatures are in C. Unless otherwise indicated, parenthetically indicated coating coverages are in grams per square meter.
Example 1 - Preparation of 1-~4-(2-formylhydrazino)-phenyl]-3,3-dimethylthiourea (NA-l) 1-Formyl-2-(4-aminophenyl)hydrazine (1.51 g, 0.01 mole) and triethylamine (1.0 g, 0.01 mole) were mixed with dry acetonitrile (30 ml). The mixture was kept under a nitrogen atmosphere and a solution of dimethylthiocarb-amoyl chloride (1.24 g, 0.01 mole) in acetonitrile (10 ml) was added dropwise at room temperature. After the addi-tion was complete, the reaction mixture was chilled in ice 9 then filtered. The solid was washed wlth e~hanol and allowed to dry. The material was stirred in water ~40 ml) and heated to 60QC to remove any hydrochloride salts. The aqueous mixture was filtered; the solid was washed with ether and dried. This gave 0.60 g (25 percent) of product as a pale tan powder, m.p. 187-189C~
Example 2 -- Preparation of l-t4-(2-acetylhydrazino)-phenyl]-3,3-dimethylthiourea (NA-5) The procedure or the preparation of NA-l in Example 1 was followed with l~acetyl-2-(4-aminophenyl)-hydrazine (0.82 g, 0.005 mole), dimethylthiocarbamoyl chloride (0.62g, 0.005 mole) and N~N-diisopropylethyl-amine (0.65 g, 0.005 mole). Yield 0.30 g (24 percent)~, m~p. 187-189C.
Example 3 -- Preparation of 1-{4-[2-(4-cyanobenzoyl)-hydrazino]phenyl}-3S3-dimethylthloure~
(NA~10) 1 (4-Aminophenyl)-2-(4 cyanobenzoyl)hydrazine (1.6 g, 0.0063 mole) and N,N-diisopropylethylamine ~0.83 g, 0.0064 mole) were slurried in dry acetonitrile (60 ml).

.. ., j ..

3~

-51a-Dimethylthiocarbamoyl chloride (0.8 g, 0.0065 mole) in dry acetonitrile (15 ml) was added dropwise, then the mixture was stirred under nitrogen overnight. The mixture was evaporated to dryness; the residue was washed with water to give a red-brown solid. 1.5 g of the solid was separated on a Waters preparative liquid chromatograph (silica gel column; methylene chloride/acetonitrile, 4:1, as eluant).
Fraction 10 gave~ on recrystallization from acetonitrile~
0.10 g (5 percent) of product as an off~white solid, m.p.
205-209C (dec).
Example 4 -- Preparation of 1-[4-(2-formylhydrazino)-phenyl]-3,3-dibenzylthiourea (NA-ll) 4-(2-Formylhydrazino)phenyl isothiocyanate was first prepared in the following mannerO l-formyl-2-(4-aminophenyl)hydrazine (1.1 g, 0.0075 mole) was dissolvedin dry acetone (75 ml) and the resulting solution was cooled to -78C in a dry ice-acetone bath. The reaction mixture was stirred and kept under a nitrogen atmosphere.
A solution of l,l'-thiocarbonyldiimidazole (1.35 g, 0.0075 mole) in dry acetone (75 ml) was added dropwise to the reaction mixture. After the addition was complete, the mixture was stirred for 30 minutes at -780C, then allowed to warm to room temperature. The solvent was removed at reduced pressure. The remaining solid residue was stirred in water at room temperature. The solid was filtered off, washed with water, then ether, and allowed to dry. The crude product was recrystallized from acetone to give 0.80 g (55 percent) of a white crystalline powder, m.p. 178-180C.
3 Dibenzylamine (0.20 g, 0.001 mole) and 4-(2-formylhydrazino)phenyl isothiocyanate (0.19 g, 0.001 mole) were mixed in ethanol (25 ml) and the resulting mixture was heated to reflux for 20 minutes. The reaction mixture was cooled to room temperature, t~len was chilled in ice.
After scratching the flask walls, a white crystalline solid was separated out of solution. The solid was filtered off, washed thoroughly with ether, and allowed to dry. This gave 0.31 g (80 percent) of product as a white crystalline powder, m.p. 174-176C.

: :

3~i Example 5 -- Preparation of 1-[4-(2-acetylhydrazino)-phenyl]-3,3-dibenzylthiourea (NA-12) 4-(2-Acetylhydrazino)phenyl isothiocyanate was prepared as described for NA-ll in Example 4 with 1-acetyl-2-(4-aminophenyl)hydrazine (1.23 g, 0.0075 mole) and l,l'-thiocarbonyldiimidazole (1.35 g, 0.0075 mole).
Yield 1.20 g (77 percent), m.p. 172-174C.
Dibenzylamine (0.20 g, 0.001 mole) and 4-(2-acetylhydrazino)phenyl isothiocyanate (0.21 g, 0.001 mole) were r-eacted according to the procedure described for MA-11 in Example 4. Yield 0.35 g (88 percent), m.p. 207-Example 6 -- Preparation of 1-{4-[2-(4-chlorobenzoyl)-hydrazino)phenyl}-3,3-dibenzylthiourea NA-13) 4-[2-(4-Chlorobenzoyl)hydrazino]phenyl iso-thiocyanate was prepared as described for NA-ll in Example 4 with 1-(4-chlorobenzoyl)-2-(4-aminophenyl)hydrazine hydrochloride (o.60 g, 0.002 mole), l,l'-thiocarbonyldi-imidazole (0.39 g, 0.002 mole), and triethylamine (0.20 g,0.002 mole). Yield 0.45 g (74 percent) from acetonitrile, m.p. 181C~
Dibenzylamine (0.20 g, 0.001 mole) and 4-[2-(4-chlorobenzoyl)hydrazino]phenylisothiourea (0.30 g, 0.001 mole) were reacted according to the procedure described for NA-ll in Example 4. Yield 0.18 g (36 percent), m.p.
174-176C.
Example 7 -- Preparation of 1-[4-(2-formylhydrazino)-phenyl]-3-methyl-3-phenylthiourea (NA 14) N-Methylaniline (0.11 g, 0.001 mole) and 4-(2-formylhydrazino)phenyl isothiocyanate (0.19 g, 0.001 mole) were reacted according to the procedure described for NA-11 in Example 4. Yield 0.15 g (50 percent), m.p. 137-139C. 5 Example 8 -- Preparation of 1-~4-(2-formylhydrazino)-phenyl]-3,3-dibutylthiourea (NA-15) Di-n-butylamine (0.13 g, 0.001 mole) and 4-(2-formylhydrazino)phenyl isothiocyanate (0.19 g, 0.001 mole) "; ' ~, 3~

were reacted according to the procedure described for NA-11 in ~xample 4. Yield 0.10 g (31 percent), m.p. 139-141C.
Example 9 -- Preparation of 4-[4-(2-formylhydrazino)-phenylthiocarbamoyl]morpholine ~NA-21) Morpholine to.o87 g, 0.001 mole) and 4-(2-formyl-hydrazino)phenyl isothiocyanate (0.19 g, 0.001 mole) were reacted according to the procedure described for NA-ll in Example 4. Yield 0.22 g ~79 percent), m.p. 204-206C.
10 Example 10 -- Preparation of 1-[4-(2-formylhydrazino)-phenylthiocarbamoyl]piperidine (NA-32) Piperidine ~o.o85 g, 0.001 mole) and 1-(2-formylhydrazino)phenyl isothiocyanate (0.19 g, 0.001 mole) were reacted according to the procedure described for NA-ll 15 in Example 4. Yield 0.14 g (50 percent), m.p. 174-176C.
hxample 11 -- Preparation of 1-[4-(2-formylhydrazino)-phenylthiocarbamoyl]pyrrolidine (NA-26) Pyrrolidine (0.071 g, 0.001 mole) and 1-(2-formylhydrazino)phenyl isothiocyanate (0.19 g, 0.001 mole) 20 were reacted according to the procedure described for NA-ll in Example 4. Yield 0.15 g (58 percent), m.p.
199-201C.
Example 12 -- Preparation of 1-[4-(2-formylhydrazino)-phenylthiocarbamoyl]-3-pyrroline (NA-25) 3-Pyrroline (0.069 g, 0.001 mole) and 1-(2-formylhydrazino)phenyl isothiocyanate (0.19 g, 0.001 mole) were reacted according to the procedure described for NA-ll in Example 4. Yield 0.18 g (69 percent)g m.p.
218-220C.
3 Example 13 -- Preparation of 1-{4-[2-(4-chlorobenzoyl)-hydrazino}phenyothiocarbamoyl}piperidine ~NA-33~
Piperidine (Q.085 g, 0.001 mole) and 4-[2-(4~
chlorobenzoyl) hydrazino]phenyl isothiocyanate (0.30 g, 0.001 mole) were reacted according to the procedure des-cribed for NA-ll in Example 4. Yield 0.37 g C95 percen-t3, m.p. 193-195C.
Example 14 -- Photographic Comparisons A photographic multicolor image transfer element - :, -: . . . .
- :, : :
:, : : .

was prepared by coating onto a polyester form support to produce the indicated layer arrangement. (Coverages are expressed in g/m2 unless otherwise specified.~
Layer 9 -- Overcoat layer of gelatin (o.86) and a latex mordant, poly(styrene-co-N-vinylbenzyl-N-benzyl-N,N'-dimethylammonium sulfate-co-divinyl-benzene ~0.11) _ Layer 8 -- Blue-sensitive internal image gelatin (0.81? silver bromide ~0.75~ emulsion; sodium 5-octadecylhydroquinoe-2-sulfonate tl2 g/mole Ag);
and the same prior art nucleating agent present in Layer 2 (10 mg/mole Ag~
Layer 7 -- Gelatin ~1.08) and a yellow redox dye-releaser of the type described iIl U. S . Patent 4 013,633 (~.65) Layer 6 -- Interlayer of gelatin (0.97) and di-dodecylhydroquinone (0.70) _ _ Layer 5 -- Green-sensitive internal image gelatin (0.81) silver bromide (0.75) emulsion; sodium 5 octadecylhydroqulnone-2-sulfonate (12 g/mole Ag);
and the same prior art nucleating agent present in Layer 2 (lO mg/mole Ag) ; Layer 4 -- Gelatin ~l.o8) and a magenta redox dye-releaser of the type described in U.S. Patent 3 954 476 (0.54) Layer 3 -- Interlayer of gelatin (0.97) and di-dodecylhydroquinone (0~70) Layer 2 -- Red-sensitive internal image gelatin (1.08) silver bromide (0.75) emulsion; sodium 5-octadecylhydroquinone-2-sulfonate (12~g/mole Ag);
and prior art nucleating agent 1-[4-(2-formyl-hydrazino~phenyl]-3-methylthiourea ~C l~ ~8 mg/-mole Ag~
Layer l -- Gelatin ~l.o8) and a cyan redox dye-releaser of the type disclosed in U.S. Patent 3,942,987 (0 54) / / / / / / / / / S U P P O R T / / / / / / / /

,, A second element was identically prepared, except that the three emulsion layers each contained the nucleat-ing agent l-[4-~2-formylhydrazino~phenyl]-3~3-dimethyl-thiourea ~NA-1~ of the invention substituted at the same concentration for the prior art nucleating agent 1-[4-t2-formylhydrazino~phenyl]-3-methylthiourea (C-l).
Each element was exposed to a multicolor grad-uated density test object for 0.5 second and soaked for 15 seconds in an activator at 29C, identified as Activator Solution A ~described below in Table I~.
TAB~E_I~
benzyl alcohol 10 ml 5-methylbenzotriazole1 g 11-aminoundecanoic acid2 g

6-aminohexanoic acid10 g 0.5 N potassium hydroxide to 1 liter pH 13.5 The element was then laminated to a dry image receiver sheet for two minutes, then peeled apart, and 2~ the receiver was washed with water.
The receiver sheet comprised the following layers coated on a polyolefin-coated paper support.
. .
Layer 2 -- An overcoat layer of polyvinyl alcohol (0 11) (Elvanol 71-30) --Layer 1 -- A mordant layer of gelatin (2.28) and a latex poly(styrene-co-N-vinylbenzyl-N-benzyl-N,N-dimethylammonium sulfate-co-divinylbenzene) (2.28), 4-hydroxymethyl-4-methyl-1-phenyl-3-pyrazolidinone 3 (0.16) The DmaX and Dmin of the sensitometric curves are shown in Table V.

~ .

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~1 a P; o o ~ ~ ~.
a) ~ LS~
a s o o a~ Lf~ oo m o o ~1 u~ o a) ~ ~
~; o s~
r~
CC) ~D
E~ ~ co C~l :: :q ~

, r~
~ I
~ a) ~ ¢
Z
o Io C~
rl S~
: N N
O
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O S
b~ :>~
¢
~ ~ s, a O ~ O ~
~rl ~
a) i I
O ~ IJ
~ l Z

' . , : . _ :: , , ,-, ': ' : '; ' ~' ' ' ' The data show that nucleating agent NA-l is a more active nucleating agent than the 3-mono-substituted nucleating agent C-l as indicated by the higher DmaX and Dmin values at the same concentration. An unexpected result of coating this layer structure directly on poly-ester support is overcoming the suppression of the release of cyan dye in layers containing the nucleating agent C-l.
This suppression is completely overcome by using the 3,3-disubstituted thiourea-containing nucleating agents of 10 this invention.
Example 15 A series of photographic single color image transfer elements were prepared~having the following layers coated on a black opaque polyester support. The ; 15 coatings dif~ered only in the type of nucleating agent in the emulsion layer. The prior art nucleating agent 1-[4-(2-formylhydrazino)phenyl]-3-phenylthiour~a (C-2) of U.S. Patent 4,0302925 was coated at 4.5 X 10 5 mole/mole Ag. The compounds of the invention were su~stituted at 20 the same concentration in otherwise identical elements.
The elements exhibited the following layer arrangement.

Layer 3 -- An overcoat layer of gelatin ( o . 86) and a latex mordant poly~styrene-co-N-vinylbenzyl-N-benzyl-N,N-dimethylammonium sulfate-co-divinyl-benzene) (0.11) , Layer 2 -- A green-sensitive internal-image silver bromide (0.43 Ag) gelatin (1.1~ emulsion including 12 g/mole sodium 5-octadecylhydroquinone-2-sulfon-ate and the nucleating agent Layer 1 -- Gelatin ~1.34) and magenta redox dye- -~
releaser (o.48~ of the type disclosed in Fernandez U.S. Patent 42135,929 The elements were exposed as described in ~xample 14, given a 10 second soak in an activator2 either Acti-vator Solution A (described above in Table IV~ or Activator Solution B (described below in Table VI) at 29C~ and then ~.;

:

. : : - .: .: ..
1 , ; : ~: : ; : : :
,: :. : :
:. : .... . , .:
:.
.,; ,~ `

laminated to a dry image receiver sheet for two minutes, peeled apart, and the receiver sheet washed with water.
TABL~ VI
benzyl alcohol ~ ml 5-methylbenzotriazole 1 g ll-aminoundecanoic acid 2 g KBr 4 g 0.5 N potassium hydroxide to 1 liter pH 13.5 The receiver sheet was comprised of a mordant layer coated on a polyolefin-coated paper support, as indicated below.
-A mordant layer of gelatin ~1.71) and poly(N-vinylimidazole-co-3-~-hydroxyethyl-1-vinylimida-zolium chloride) (2.28), 4-hydroxymethyl-~-methyl-l-phenyl-3-pyrazolidininone (0.16) The activity levels of the nucleating agents are compared in Table V~I, which compares relative nucleating activity of compounds of this invention with prior art nucleating agent C-2. The activity rating value is based upon the concentration of nucleating agent that is required to match as closely as possible the characteristic curve (that is, similar DmaX, contrast, speed and Dmin) as prior art nucleating agent C-2. For example, with C-2 assigned an activity rating of 1.0, a nucleating agent with a rating of 2.0 is twice as active--i.e., only one-half the concen-tration of nucleating agent on a molar weight basis is 3 required to give the same relative curve shape as compound C-2. Acylhydrazinophenylthioureas having a formyl acyl group are more active than comparable nucleating agents having acetyl or benzoyl acyl groups. The fact that the nucleating activity of NA-5 and NA-10 is on a generally 35 comparable level to that of C-2 indicates that NA-5 and NA-10 will exhibit a substantially superior nucleating agent activity as compared to otherwise identical nucleat-ing agents that are mono-substituted in the 3-position.

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Example 16 A comparison between nucleating agent C-l at a concentration of 1.8 X 10 4 mole~mole Ag and a nucleating agent of the invention was made utilizing an activator solution having a pH of only 12Ø
Single color image transfer elements were pre-pared having the following layer arrangement coated on a black opaque polyester support.

Layer 3 ~- An overcoat layer of gelatin (o.86) and a latex mordant poly(styrene co-N-vinylbenzyl-N-benzyl-N,N-dimethylammonium sulfate-co-divinyl-benzene (0.11) _ Layer 2 -- A green-sensitive internal image silver bromide (1.07 Ag) gelatin tl.61) emulsion includ ing 12 g/mole sodium 5-octadecylhydroquinone-2-sulfonate and the nucleating agent Layer 1 -- Gelatin (1.61) and a magenta redox dye-releaser E (0. 54 ) of the type disclosed by U.S.
Patent 3,954,476 The elements were exposed for 0.2 second through a graduated density test object, soaked for 40 seconds in 25 Activator Solution C (described below in Table VIII) at ;~
22C, and then laminated to a dry image receiver sheet for 3 minutes, peeled apart and the receiver sheet washed with water.
TABLE VIII
3 Activator Solution C
K3P04 60 g benzyl alcohol 10 ml 5-methylbenzotriazole 1 g ll-aminoundecanoic acid 2 g distilled water to 1 liter pH 12.0 The receiver sheet was comprised of a mordant layer coated over a gelatin layer (0.86) on a polyolefin-coated paper support. The mordant layer consisted of gelatin (2.28) and poly(styrene-co-N-vinylbenzyl-N-benzyl-N,N-dimethylammonium sulfate-co-divinylbenzene) (2.28) and 4-hydroxymethyl-4-methyl-1-phenyl-3-pyrazolidinone (0.22).
The results are set forth below in Table IX.
TABLE IX
Relative Nucleation Activity Activity Rating Nucleator Solution C
lO 1-~4-(2-formylhydrazino)phenyl]-3-methylthiourea (C-l) l.0 l ~4-(2-formylhydrazino)phenyl]-3,3-dimethylthiourea (NA-l) 2.1 This demonstrates the superior nuc~eation activity of the 15 nucleating agents of this invention as compared with prior art acylhydrazinophenylthiourea nucleating agents at lower pH levels.
The invention has been described in detail with particular reference to preferred embodiments thereof, but ,~ 20 it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

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Claims (38)

1. WHAT IS CLAIMED IS
   l. A silver halide emulsion comprised of silver halide grains capable of forming an internal latent image and, adsorbed to the surface of said silver halide grains, a nucleating amount of a 3,3-disubstituted acylhydrazino-phenylthiourea of the formula wherein R is hydrogen; an alkyl, cycloalkyl, haloalkyl, alkoxy-alkyl or phenylalkyl substituent or a phenyl nucleus having a Hammett sigma value-derived electron-withdrawing char-acteristic more positive than -0.3;
   Rl is a phenylene or alkyl, halo- or alkoxy-substituted phenylene group; and R2 and R3 are independently selected from among alkyl, haloalkyl, alkoxyalkyl or phenylalkyl substituents having from 1 to 18 carbon atoms; a cycloalkyl substituent; a phenyl nucleus having a Hammett sigma value-derived elec-tron withdrawing characteristic less positive than +0.50;
   and naphthyl; or R2 and R3 together form a heterocyclic nucleus forming a 5- or 6-membered ring, wherein the ring atoms are chosen from the class consisting of nitrogen, carbon, oxygen, sulfur and selenium atoms;
   the alkyl moieties, except as otherwise noted, in each instance include from l to 5 carbon atoms; and the cycloalkyl moieties have from 3 to 10 carbon atoms.
2. 2. A silver halide emulsion according to Claim 1 wherein said 3,3-disubstituted acylhydrazinophenylthiourea is of the formula wherein R2 and R3 are independently selected from among alkyl and phenylalkyl substituents, wherein the alkyl moieties are in each instance from 1 to 6 carbon atoms, and a phenyl nucleus having a Hammett sigma value-derived electron-withdrawing characteristic less positive than +0.05; or R2 and R3 together form a saturated heterocyclic nucleus forming a 5- or 6-membered ring, wherein the ring atoms are chosen from the class consisting of nitrogen, carbon, oxygen, sulfur and selenium atoms.
3. 3. A silver halide emulsion according to Claims 1 or 2 wherein said 3,3-disubstituted acylhydrazinophenyl-thiourea is present in a concentration of from 0.1 to 500 mg per mole of silver.
4. 4. A silver halide emulsion according to Claims 1 or 2 wherein said silver halide grains are predominantly silver bromide and contain metal dopants occluded therein, which grains have been chemically sensitized on the sur-face thereof to a level which would produce a density of less than 0.4 when imagewise exposed and developed in a test surface developer for 5 minutes at 27°C and to at least a level which would produce a density of greater than 0.5 in an undoped silver halide emulsion of the same grain size and halide composition when exposed and de-veloped in the test surface developer, provided said emul-sions are coated at a coverage of between about 3 and 4 grams per square meter.
5. 5. A photographic element comprised of a sup-port bearing a silver halide emulsion layer comprising silver halide grains capable of forming an internal latent image and, adsorbed to the surface of said silver halide grains, a nucleating amount of a 3,3-disubstituted acyl-hydrazinophenylthiourea of the formula wherein R is hydrogen; an alkyl, cycloalkyl, haloalkyl, alkoxyalkyl or phenylalkyl substituent or a phenyl nucleus having a Hammett sigma value-derived electron-withdrawing characteristic more positive than -0.3;
   
   R1 is a phenylene or alkyl, halo- or alkoxy-substituted phenylene group; and R2 and R3 are independently selected from among alkyl, haloalkyl, alkoxyalkyl or phenylalkyl substituents having from 1 to 18 carbon atoms; a cycloalkyl substituent;
   a phenyl nucleus having a Hammett sigma value-derived electron-withdrawing characteristic less positive than +0.50; and naphthyl; or R2 and R3 together form a hetero-cyclic nucleus forming a 5- or 6-membered ring, wherein the ring atoms are chosen from the class consisting of nitrogen, carbon, oxygen, sulfur and selenium atoms;
   the alkyl moieties, except as otherwise noted, in each instance include from 1 to 6 carbon atoms; and the cycloalkyl moieties have from 3 to 10 carbon atoms.
6. 6. A photographic element according to Claim 5 wherein the 3,3-disubstltuted acylhydrazinophenylthiourea is of the formula wherein R2 and R3 are independently selected from among alkyl and phenylalkyl substituents, wherein the alkyl moieties are in each instance from 1 to 6 carbon atoms9 and a phenyl nucleus having a Hammett sigma value-derived elec-tron-withdrawing characteristic less positive than +0.50;
   or R2 and R3 together form a saturated heterocyclic nucleus forming a 5- or 6-membered ring, wherein the ring atoms are chosen from the class consisting of nitrogen, carbon, oxygen, sulfur and selenium atoms.
7. 7. A photographic element according to Claims 5 or 6 wherein said 3,3-disubstituted acylhydrazinophenyl-thiourea is present in a concentration of from 1.0 to 100 mg per mole of silver.
8. 8. A photographic element according to Claim 6 wherein said silver halide grains contain a metal dopant;
   provide a maximum optical density less than 0.25 when coated on a support at a density of from 3 to 4 grams per square meter, exposed to a light intensity scale for a fixed time of from 1 x 10-2 to 1 second and developed for 5 minutes at 25°C in the surface developer; and provide a maximum optical density at least 5 times greater than the above maximum density when the above procedure is repeated additionally including in the surface developer 0.5 gram per liter of potassium iodide to form an internal developer
9. 9. A process of obtaining a direct-positive image comprising imagewise exposing a photographic element comprised of a support and coated on the support, a silver halide emulsion layer comprising silver halide grains capable of forming an internal latent image and, adsorbed to the sur-face of the silver halide grains, a nucleating amount of a 3,3-disubstituted acylhydrazinophenylthiourea of the formula wherein R is hydrogen; an alkyl, cycloalkyl, haloalkyl, alkoxyalkyl or phenylalkyl substituent or a phenyl nucleus having a Hammett sigma value-derived electron-withdrawing characteristic more positive than -0.3;
   R1 is a phenylene or alkyl, halo- or alkoxy-substituted phenylene group; and R2 and R3 are independently selected from among alkyl, haloalkyl, alkoxyalkyl or phenylalkyl substituents having from l to 18 carbon atoms; a cycloalkyl substituent;
   a phenyl nucleus having a Hammett sigma value-derived electron-withdrawing characteristic less positive than +0.50; and naphthyl; or R2 and R3 together form a hetero-cyclic nucleus forming a 5- or 6 membered ring, wherein the ring atoms are chosen from the class consisting of nitrogen, carbon, oxygen, sulfur and selenium atoms;
   the alkyl moieties, except as otherwise noted, in each instance include from 1 to 6 carbon atoms; and the cycloalkyl moieties have from 3 to 10 carbon atoms, and selectively developing the silver halide grains remaining unexposed.
10. 10. A nucleating agent of the formula wherein R is hydrogen; an alkyl, cycloalkyl, haloalkyl, alkoxyalkyl or phenylalkyl substituent or a phenyl nucleus having a Hammett sigma value-derived electron-withdrawing characteristic more positive than -0.3;
    R1 is a phenylene or alkyl, halo- or alkoxy-substituted phenylene group; and R2 and R3 are independently selected from among alkyl, haloalkyl, alkoxyalkyl or phenylalkyl substituents having from 1 to 18 carbon atoms; a cycloalkyl substituent;
    a phenyl nucleus having a Hammett sigma value-derived electron-withdrawing characteristic less positive than +0.50; and naphthyl; or R2 and R3 together form a hetero-cyclic nucleus forming a 5- or 6-membered ring, wherein the ring atoms are chosen from the class consisting of nitrogen, carbon, oxygen, sulfur and selenium atoms;
    the alkyl moieties, except as otherwise noted, in each instance include from 1 to 6 carbon atoms; and the cycloalkyl moieties have from 3 to 10 carbon atoms.
11. 11. A nucleating agent of the formula wherein R2 and R3 are independently selected from among alkyl and phenylalkyl substituents, wherein the alkyl moieties are in each instance from 1 to 6 carbon atoms, and a phenyl nucleus having a Hammett sigma value-derived elec-tron-withdrawing characteristic less positive than +0.50;
    
    or R2 and R3 together form a saturated heterocyclic nucleus forming a 5- or 6-membered ring, wherein the ring atoms are chosen from the class consisting of nitrogen, carbon, oxygen, sulfur and selenium atoms.
12. 12. 1-[4-(2-formylhydrazino)phenyl]-3,3-di-methylthiourea.
13. 13. 1-[4-(2-acetylhydrazino)phenyl]-3,3-di-methylthiourea.
14. 14. 1-{4-[2-(4-cyanobenzoyl)hydrazino]phenyl}-3,3-dimethylthiourea.
15. 15. 1-[4-(2-formylhydrazino)phenyl]-3,3-di-benzylthiourea.
16. 16. 1-[4-(2-acetylhydrazino)phenyl]-3,3-di-benzylthiourea.
17. 17. 1-{4-[2-(4-chlorobenzoyl)hydrazino]phenyl}-3,3-dibenzylthiourea.
18. 18. 1-[4(2-formylhydrazino)phenyl]-3,3-dibutyl-thiourea.
19. 19. 1-[4-(2-formylhydrazino)phenyl]-3-methyl-3-phenylthiourea.
20. 20. 4-[4-(2-formylhydrazino)phenylthiocarb-amoyl]morpholine.
21. 21. 1-[4-(2-formylhydrazino)phenylthiocarb-amoyl]piperidine.
22. 22. 1-[4-(2-formylhydrazino)phenylthiocarb-amoyl]pyrrolidine.
23. 23. 1-[4-(2-formylhydrazino)phenylthiocarb-amoyl]-3-pyrroline.
24. 24. 1-{4-[2-(4-chlorobenzoyl)hydrazino]phenyl-thiocarbamoyl}piperidine.
25. 25. In an image transfer film unit which com-prises a photographic element comprising a support bearing at least one silver halide emulsion layer containing radiation sensitive internal latent image-forming silver halide grains and, adsorbed to the surface of said silver halide grains, a nucleating agent, said photographic element including an image dye-providing material within or in contact with said silver halide emulsion layer, an image-receiving means positioned to receive image dye from said photographic element, an alkaline processing composition, means containing and adapted to release said alkaline processing composition for contact with said emulsion layer, and a silver halide developing agent located in at least one of the photographic element and the alkaline process-ing composition, the improvement wherein said nucleating agent is a 3,3-disubstituted acylhydrazinophenylthiourea of the formula wherein R is hydrogen; an alkyl, cycloalkyl, haloalkyl, alkoxyalkyl or phenylalkyl substituent or a phenyl nucleus having a Hammett sigma value-derived electron-withdrawing characteristic more positive than -0.3;
    Rl is a phenylene or alkyl, halo- or alkoxy-substituted phenylene group; and R2 and R3 are independently selected from among alkyl, haloalkyl, alkoxyalkyl or phenylalkyl substituents having from 1 to 18 carbon atoms; a cycloalkyl substituent;
    a phenyl nucleus having a Hammett sigma value-derived electron-withdrawing characteristic less positive than +0.50; and naphthyl; or R2 and R3 together form a hetero-cyclic nucleus forming a 5- or 6-membered ring, wherein the ring atoms are chosen from the class consisting of nitrogen, carbon, oxygen, sulfur and selenium atoms;
    the alkyl moieties, except as otherwise noted, in each instance include from l to 6 carbon atoms; and the cycloalkyl moieties have from 3 to 10 carbon atoms.
26. 26. An improved image transfer film unit accord-ing to Claim 25 wherein said film unit incorporates an antifoggant.
27. 27. An improved image transfer film unit accord-ing to Claim 26 wherein sid antifoggant is a benzotriazole antifoggant.
28. 28. An improved image transfer film unit accord-ing to Claim 25 wherein said 3,3-disubstituted acylhydra-zinophenylthiourea is of the formula wherein R2 and R3 are independently selected from among alkyl and phenylalkyl substituents, wherein the alkyl moieties are in each instance from 1 to 6 carbon atoms, and a phenyl nucleus having a Hammett sigma value-derived electron-withdrawing characteristic less positive than +0.50; or R2 and R3 together form a saturated heterocyclic nucleus forming a 5- or 6- membered ring, wherein the ring atoms are chosen from the class consist-ing of nitrogen, carbon, oxygen, sulfur and selenium atoms.
29. 29. An image transfer film unit comprising (a) a photographic element comprising a support bearing (1) a layer containing a blue-sensitive silver halide emulsion having in contact therewith an immobile material capable of releasing a mobile yellow image dye, (2) a layer containing a green-sensitized silver halide emulsion having in contact therewith an immobile material capable of releasing a mobile magenta image dye, and (3) a layer containing a red-sensitive silver halide emulsion having in contact therewith an immobile material capable of releasing a mobile cyan image dye, wherein each of said silver halide emulsions comprises silver halide grains having metal dopants occluded therein, said grains being substantially unfogged on their surfaces and being chemically sensitized on their surfaces (a) to a level which will provide a maximum density of less than 0.4 when developed in a test surface developer of the composition indicated below for 5 minutes at 27°C after exposure to a light intensity scale for a fixed time of from 1 x 10 2 to 1 second when said photosensitive composi-tion is coated at a coverage of between about 3 and 4 grams of silver per square meter, and (b) to at least a level which would provide a maximum density of at least 0.5 using undoped silver halide grains of the same grain size and halide composition when coated, exposed and developed in like manner, (b) an image-receiving means positioned to receive image dye from said photographic element, (c) an aqueous alkaline processing composition, (d) means containing and adapted to release said alkaline processing composition into contact with said silver halide emulsions, (e) a silver halide surface developing agent located in said processing composition, and (f) from 1 to 100 mg per mole of silver of a nucleat-ing agent adsorbed to said silver halide grains within at least one of said silver halide emulsion layers, said nucleating agent having the formula wherein R2 and R3 are independently selected from among alkyl and phenylalkyl substituents, wherein the alkyl moieties are in each instance from 1 to 6 carbon atoms, and a phenyl nucleus having a Hammett sigma value-derived elec-tron-withdrawing characteristic less positive than +0.50;
    or R2 and R3 together form a saturated heterocyclic nucleus forming a 5- or 6-membered ring, wherein the ring atoms are chosen from the class consisting of nitrogen, carbon, oxygen, sulfur and selenium atoms;
    
    the test surrace developer consisting essen-tially of Water (52°C) 500.0 cc N-methyl-p-aminophenol sulfate 2.5 g Sodium sulfite, desiccated 30.0 g Hydroquinone 2.5 g Sodium metaborate 10.0 g Potassium bromide 0.5 g Water to make 1 liter.
30. 30. A photographic element according to Claim 29 wherein said silver halide grains contain a metal dopant; provide a maximum optical density less than 0.25 when coated on a support at a density of from 3 to 4 grams per square meter, exposed to a light intensity scale for a flxed time of from 1 X 10-2 to 1 second and developed for 5 minutes at 25°C in the surface developer; and provide a maximum optical density at least 5 times greater than the above maximum density when the above procedure is repeated additionally including in the surface developer 0.5 gram per liter of potassium iodide to form an internal developer.
31. 31. A photographic element according to Claim 29 wherein the immobile materials capable of relasing mobile image dye are redox dye-releasers.
32. 32. In a process of producing a visible image in an imagewise exposed photographic element having a support and, coated on the support, a silver halide emul-sion layer comprising silver halide grains capable of forming an internal latent image and, adsorbed to the sur-face of the silver halide grains, a nucleating agent in an amount sufficient to promote development of unexposed silver halide grains comprising processing in an aqueous alkaline developing composition in the presence of a developing agent, the improvement comprising developing in the presence of a 3,3-disubstituted acylhydrazinophenylthiourea of the formula wherein R is hydrogen; an alkyl, cycloalkyl, haloalkyl, alkoxyalkyl or phenylalkyl substituent or a phenyl nucleus having a Hammett sigma value-derived electron-withdrawing characteristic more positive than -0.3;
    R1 is a phenylene or alkyl, halo- or alkoxy-substituted phenylene group; and R2 and R3 are independently selected from among alkyl, haloalkyl, alkoxyalkyl or phenylalkyl substituents having from l to 18 carbon atoms; a cycloalkyl substituent;
    a phenyl nucleus having a Hammett sigma value-derived electron-withdrawing characteristic less positive than +0.50; and naphthyl; or R2 and R3 together form a hetero-cyclic nucleus forming a 5- or 6-membered ring, wherein the ring atoms are chosen from the class consisting of nitrogen, carbon, oxygen, sulfur and selenium atoms;
    the alkyl moieties, except as otherwise noted, in each instance include from l to 6 carbon atoms; and the cycloalkyl moieties have from 3 to 10 carbon atoms.
33. 33. In a process according to Claim 32 the fur-ther improvement in which the developing composition is at a pH in the range of from 13.9 to 11.8.
34. 34. In a process according to Claim 32 the fur-ther improvement in which the developing composition is at a pH in the range of from 12.0 to 13Ø
35. 35. In a process of producing a visible image in an imagewise exposed photographic element having a support and, coated on the support, a silver halide emulsion layer comprising silver halide grains and a nucleating agent in an amount sufficient to promote development of unexposed silver halide trains, the silver halide grains which have metal dopants occluded therein and which have been chemi-cally sensitized on the surface thereof (a) to a level which will provide a density of less than 0.4 when developed in Kodak Developer DK-50 for 5 minutes at 27°C after image-wise exposure when the emulsion is coated at a coverage of between about 300 to about 400 mg of silver per square foot and (b) to at least a level which would provide a density of 0.5 in an undoped silver halide emulsion of the same grain size and halide composition when coated, exposed and developed in like manner, the improvement wherein the nucleating agent is a 3,3-disubstituted acylhydrazinophenylthiourea of the formula wherein R is hydrogen; an alkyl, cycloalkyl, haloalkyl, alkoxyalkyl or phenylalkyl substituent or a phenyl nucleus having a Hammett sigma value-derived electron-withdrawing characteristic more positive than -0.3;
    Rl is a phenylene or alkyl, halo- or alkoxy-substituted phenylene group; and R2 and R3 are independently selected from among alkyl, haloalkyl, alkoxyalkyl or phenylalkyl substituents having from 1 to 18 carbon atoms; a cycloalkyl substituent;
    a phenyl nucleus having a Hammett sigma value-derived electron-withdrawing characteristic less positive than +0.50; and naphthyl; or R2 and R3 together form a hetero-cyclic nucleus forming a 5- or 6-membered ring, wherein the ring atoms are chosen from the class consisting of nitrogen, carbon, oxygen, sulfur and selenium atoms;
    the alkyl moieties, except as otherwise noted, in each instance include from 1 to 6 carbon atoms; and the cycloalkyl moieties have from 3 to 10 carbon atoms, and the developing composition is at a pH in the range of from 12.0 to 13Ø
36. 36. In a process according to claim 35 the fur-ther improvement in which the nucleating agent is of the formula wherein R2 and R3 are independently selected from among alkyl and phenylalkyl substituents, wherein the alkyl moieties are in each instance from 1 to 6 carbon atoms, and a phenyl nucleus having a Hammett sigma value-derived elec-tron-withdrawing characteristic less positive than +0.50;
    or R2 and R3 together form a saturated heterocyclic nucleus forming a 5- or 6-membered ring, wherein the ring atoms are chosen from the class consisting of nitrogen, carbon, oxygen, sulfur and selenium atoms.
37. 37. In a process according to Claim 35 the fur-ther improvement wherein a visible image is transferred to a receiver.
38. 38. In a process according to claim 37 the fur-ther improvement wherein the photographic element is a dye image transfer photographic element containing in contact with the silver halide emulsion layer an initially immobile dye releasing material and image dye is transferred to the receiver to form a visible image.