Photographic emulsions and elements capable of forming direct-positive images

Claim 2

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 dihydrospiropyran bis-condensation product of a salicylic aldehyde and at least one heterocyclic ammonium salt.

Claim 3

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 dihydrospiropyran of the formula ##STR6## wherein X and Y each independently represent a sulfur atom, a selenium atom, or a --C(R 1 R 2 )-- radical, R 1 and R 2 independently represent lower alkyl of from 1 to 5 carbon atoms or together represent an alkylene radical of 4 or 5 carbon atoms, R 3 , R 4 , R 5 , and R 6 each represent hydrogen, a hydroxy radical, or a lower alkyl or alkoxy radical of from 1 to 5 carbon atoms, Z 1 and Z 2 each represent the nonmetallic atoms completing a nitrogen-containing heterocyclic nucleus of the type found in cyanine dyes, and R 7 and R 8 each represent a ring nitrogen substituent of the type found in cyanine dyes.

Claim 4

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 dihydrospiropyran of the formula ##STR6## wherein X and Y each independently represent a sulfur atom, a selenium atom, or a --C(R 1 R 2 )-- radical, R 1 and R 2 independently represent lower alkyl of from 1 to 5 carbon atoms or together represent an alkylene radical of 4 or 5 carbon atoms, R 3 , R 4 , R 5 , and R 6 each represent hydrogen, a hydroxy radical, or a lower alkyl or alkoxy radical of from 1 to 5 carbon atoms, Z 1 and Z 2 each represent the nonmetallic atoms completing a nitrogen-containing heterocyclic nucleus of the type found in cyanine dyes, and R 7 and R 8 each represent a ring nitrogen substituent of the type found in cyanine dyes.

Claim 5

A silver halide emulsion according to claim 2 wherein said dihydrospiropyran is present in a concentration of from 10 -4 to 10 -2 mole per mole of silver halide.

Claim 6

A silver halide emulsion according to claim 1, 2, or 3 wherein said silver halide grains are predominantly silver bromide and contain metal dopants occluded therein, which grains when coated on a photographic support, exposed to a light intensity scale, and developed for 5 minutes at 25° C. in test surface developer provide (a) a density of less than 0.4 and (b) a density of at least 0.5 less than when this testing procedure is repeated modifying the test surface developer by the inclusion of 0.5 gram per liter of potassium iodide, the test surface developer being of the following composition: ______________________________________ Water 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 1.0 liter. ______________________________________

Claim 7

A silver halide emulsion according to claim 4 wherein Z 1 and Z 2 are chosen to complete a heterocyclic nucleus chosen from the class consisting of thiazole, benzothiazole, naphthonthiazole, selenazole, benzoselenazole, naphthoselenazole, and indolenine.

Claim 8

A silver halide emulsion according to claim 4 wherein R 7 and R 8 each represent a ring nitrogen alkyl substituent of the type found in cyanine dyes.

Claim 9

In a photographic element comprised of a support and a silver halide emulsion layer comprised of silver halide grains capable of forming an internal latent image and, adsorbed to the surface of said silver halide grains, a nucleating agent, the improvement comprising said nucleating agent being a dihydrospiropyran bis-condensation product of salicylic aldehyde and at least one heterocyclic ammonium salt.

Claim 10

In a photographic element comprised of a support and a silver halide emulsion layer comprised of silver halide grains capable of forming an internal latent image and, adsorbed to the surface of said silver halide grains, a nucleating agent, the improvement comprising said nucleating agent being a dihydrospiropyran bis-condensation product of salicylic aldehyde and at least one heterocyclic ammonium salt.

Claim 11

In a photographic element capable of forming direct-reversal photographic images comprised of a support and at least one color-forming layer unit comprised of a silver halide emulsion layer containing silver halide grains capable of forming an internal latent image and, adsorbed to the surface of said silver halide grains, a nucleating agent, the improvement comprising said nucleating agent being a dihydrospiropyran of the formula ##STR7## wherein X and Y each independently represent a sulfur atom, a selenium atom, or a --C(R 1 R 2 )-- radical, R 1 and R 2 independently represent lower alkyl of from 1 to 5 carbon atoms or together represent an alkylene radical of 4 or 5 carbon atoms, R 3 , R 4 , R 5 , and R 6 each represent hydrogen, a hydroxy radical, or a lower alkyl or alkoxy radical of from 1 to 5 carbon atoms, Z 1 and Z 2 each represents the nonmetallic atoms completing a nitrogen-containing heterocyclic nucleus of the type found in cyanine dyes, and R 7 and R 8 each represent a ring nitrogen substituent of the type found in cyanine dyes.

Claim 12

In a photographic element capable of forming direct-reversal photographic images comprised of a support and at least one color-forming layer unit comprised of a silver halide emulsion layer containing silver halide grains capable of forming an internal latent image and, adsorbed to the surface of said silver halide grains, a nucleating agent, the improvement comprising said nucleating agent being a dihydrospiropyran of the formula ##STR7## wherein X and Y each independently represent a sulfur atom, a selenium atom, or a --C(R 1 R 2 )-- radical, R 1 and R 2 independently represent lower alkyl of from 1 to 5 carbon atoms or together represent an alkylene radical of 4 or 5 carbon atoms, R 3 , R 4 , R 5 , and R 6 each represent hydrogen, a hydroxy radical, or a lower alkyl or alkoxy radical of from 1 to 5 carbon atoms, Z 1 and Z 2 each represents the nonmetallic atoms completing a nitrogen-containing heterocyclic nucleus of the type found in cyanine dyes, and R 7 and R 8 each represent a ring nitrogen substituent of the type found in cyanine dyes.

Claim 13

In a direct-reversal photographic element according to claim 8 the further improvement in which said dihydrospiropyran is of the formula ##STR8## wherein X and Y each independently represent a sulfur atom, a selenium atom, or a --C(R 1 R 2 )-- radical, R 1 and R 2 independently represent lower alkyl of from 1 to 5 carbon atoms or together represent an alkylene radical of 4 or 5 carbon atoms, R 3 represents hydrogen, a hydroxy radical, or a lower alkyl or alkoxy radical of from 1 to 5 carbon atoms, and R 7 and R 8 each represents an alkyl substituent of from 1 to 5 carbon atoms.

Claim 14

In a photographic element according to claim 9 the further improvement in which X and Y are both sulfur.

Claim 15

In a photographic element according to claim 10 the further improvement in which said dihydrospiropyran is 3,4-dihydro-3'-methyl-4-(3-methyl-2-benzothiazolinylidenemethyl)spiro[2H-1-benzopyran-2,2'-benzothiazoline] or 3,4-dihydro-8-methoxy-3'-methyl-4-(3-methyl-2-benzothiazolinylidenemethyl)spiro[2H-1-benzopyran-2,2'-benzothiazoline].

Claim 16

In a photographic element according to claim 9 the further improvement in which X and Y are both --C(R 1 R 2 )--.

Claim 17

In a photographic element according to claim 12 the further improvement in which said dihydrospiropyran is 3,4-dihydro-1',3',3'-trimethyl-4-(1,3,3-trimethylindolinylidenemethyl)spiro[2H-1-benzopyran-2,2'-indoline] or 3,4-dihydro-8-methoxy-1',3',3'-trimethyl-4-(1,3,3-trimethylindolinylidenemethyl)spiro[2H-1-benzopyran-2,2'-indoline].

Claim 18

In a photographic element according to claim 7, 8, 9, 10, 11, 12 or 13 the further improvement wherein said silver halide grains are predominantly silver bromide and contain metal dopants occluded therein, which grains when coated on a photographic support, exposed to a light intensity scale, and developed for 5 minutes at 25° C. in test surface developer provide (a) a density of less than 0.25 and (b) a density of at least 5 times greater when this testing procedure is repeated modifying the test surface developer by the inclusion of 0.5 gram per liter of potassium iodide, the test surface developer being of the following composition: ______________________________________ Water 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 1.0 liter. ______________________________________

Claim 19

In a photographic element according to claim 14 the further improvement wherein said dihydrospiropyran is present in a concentration of from 10 -2 to 10 -4 mole of nucleating agent per mole of silver.

Claim 20

In a process of producing by surface development 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 capable of forming an internal latent image and, adsorbed to the surface of the silver halide grains, a nucleating agent in an amount sufficient to promote surface development of unexposed silver halide grains, the improvement comprising developing in the presence of a dihydrospiropyran bis-condensation product of salicylic aldehyde and at least one heterocyclic ammonium salt.

Claim 21

In a process of producing by surface development 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 capable of forming an internal latent image and, adsorbed to the surface of the silver halide grains, a nucleating agent in an amount sufficient to promote surface development of unexposed silver halide grains, the improvement comprising developing in the presence of a dihydrospiropyran bis-condensation product of salicylic aldehyde and at least one heterocyclic ammonium salt.

Claim 22

A process of producing a direct-reversal dye image in a photographic element comprised of a support and at least one color-forming layer unit comprised of a dye-forming coupler and a silver halide emulsion layer containing silver halide grains capable of forming an internal latent image and, adsorbed to the surface of said silver halide a dihydrospiropyran nucleating agent of the formula ##STR9## wherein X and Y each independently represent a sulfur atom, a selenium atom or a --C(R 1 R 2 )-- radical, R 1 and R 2 independently represent lower alkyl of from 1 to 5 carbon atoms or together represent an alkylene radical of 4 or 5 carbon atoms, R 3 represents hydrogen, a hydroxy radical or a lower alkyl or alkoxy radical of from 1 to 5 carbon atoms and R 7 and R 8 each represent an alkyl substituent of from 1 to 5 carbon atoms, comprising developing the photographic element in a surface developer having a pH in the range of from 10 to 13 containing a color-developing agent.

Claim 23

A process of producing a direct-reversal dye image in a photographic element comprised of a support and at least one color-forming layer unit comprised of a dye-forming coupler and a silver halide emulsion layer containing silver halide grains capable of forming an internal latent image and, adsorbed to the surface of said silver halide a dihydrospiropyran nucleating agent of the formula ##STR9## wherein X and Y each independently represent a sulfur atom, a selenium atom or a --C(R 1 R 2 )-- radical, R 1 and R 2 independently represent lower alkyl of from 1 to 5 carbon atoms or together represent an alkylene radical of 4 or 5 carbon atoms, R 3 represents hydrogen, a hydroxy radical or a lower alkyl or alkoxy radical of from 1 to 5 carbon atoms and R 7 and R 8 each represent an alkyl substituent of from 1 to 5 carbon atoms, comprising developing the photographic element in a surface developer having a pH in the range of from 10 to 13 containing a color-developing agent.

Claim 24

A process according to claim 17 in which the pH of the developer is maintained in the range of from 10.2 to 12.0.

Claim 25

A process according to claim 17 in which the surface developer contains a benzotriazole antifoggant.

Claim 26

A process according to claim 19 in which the surface developer contains a para-phenylenediamine color-developing agent and a reductone developing agent.