2H-benzimidazole photoreductive imaging

Claim 2

IN A PHOTOGRAPHIC ELEMENT HAVING A SUPPORT AND COATED THEREON AT LEAST ONE RADIATION-SENSITIVE IMAGE-RECORDING LAYER COMPRISED OF A SOURCE OF LABILE HYDROGEN ATOMS, AN IMAGERECORDING MEANS FOR REGISTERING AN ABSORPTION CHANGE UPON REDUCTION BY A PHOTOREDUCTANT, SAID MEANS BEING SELECTED FROM THE GROUP CONSISTING OF AMINOTRIARYLMETHANE DYES, AZO DYES, XANTHENE DYES, TRIAZINE DYES, NITROSO DYE COMPLEXES, INDIGO DYES, PHTHALOCYANINE DYES, TETRAZOLIUM SALTS, AND TRIAZOLIUM SALTS; AND A PHOTOREDUCTANT IN INTIMATE ASSOCIATION WITH SAID IMAGE-RECORDING MEANS, SAID PHOTOREDUCTANT BEING CAPABLE OF FORMING A REDUCING AGENT IN THE PRESENCE OF SAID HYDROGEN ATOMS; THE IMPROVEMENET IN WHICH SAID PHOTOREDUCTANT IS A 2H-BENZIMIDAZOLE.

Claim 3

In a photographic element according to claim 1 the further improvement in which said hydrogen atoms are supplied by a compound external to said photoreductant.

Claim 4

In a photographic element according to claim 2 the further improvement in which said external hydrogen source compound incorporates a labile hydrogen atom attached to a carbon atom which is also bonded to the oxygen atom of an oxy substituent or the nitrogen atom of an amine substituent.

Claim 5

In a photographic element according to claim 2 the further improvement in which said external hydrogen source compound is a polymer capable of functioning as a binder for said image recording layer.

Claim 6

In a photographic element according to claim 4 the further improvement in which said polymer binder is a cellulosic compound.

Claim 7

In a photographic element according to claim 5 the further improvement in which said polymer binder is cellulose acetate butyrate.

Claim 8

In a photographic element according to claim 2 the further improvement in wHich said hydrogen source means is phenyl-1,2-ethanediol.

Claim 9

In a photographic element according to claim 1 the further improvement in which said image-recording means is a triaryl-2H-tetrazolium salt.

Claim 10

In a photographic element according to claim 1 the further improvement in which said 2H-benzimidazole incorporates an electron donating substituent.

Claim 11

In a photographic element according to claim 9 the further improvement in which said 2H-benzimidazole incorporates an alkoxy group as an electron donating substituent.

Claim 12

In a photographic element according to claim 10 the further improvement in which said alkoxy group contains 6 or fewer carbon atoms.

Claim 13

In a photographic element according to claim 1 the further improvement in which said 2H-benzimidazole incorporates a trihalomethyl group.

Claim 14

In a photographic element according to claim 1 te further improvement in which said 2H-benzimidazole incorporates a carboalkoxy group.

Claim 15

In a photographic element according to claim 13 the further improvement in which said carboalkoxy group incorporates six or fewer carbon atoms in said alkyl moiety.

Claim 16

In a photographic element according to claim 1 the further improvement in which said 2H-benzimidazole is a spiro(2H-benzimidazole-1'',2-cyclohexane).

Claim 17

In a photographic element according to claim 1 the further improvement in which said 2H benzimidazole is a dispiro(2H-benzimidazole-2,1''-cyclohexane-40'',2''''-2H-benzimidazole).

Claim 18

In a photographic element according to claim 1 the further improvement in which from 0.1 to 10 moles of said image-recording means are present per mole of photoreductant.

Claim 19

In a photographic element according to claim 2 the further improvement in which said hydrogen source means is present in a concentration of at least 0.5 moles per mole of said photoreductant.

Claim 20

In a photographic element according to claim 1 the further improvement in which said photographic element incorporates a binder in said image-recording layer in a concentration of up to about 99 percent by weight.

Claim 21

In a photographic element according to claim 19 the further improvement in which said photographic element incorporates a binder in said image-recording layer in a concentration of from 50 to 90 percent by weight.

Claim 22

In a photographic element according to claim 17 the further improvement in which said image-recording means and said photoreductant are present in substantially equal molar proportions.

Claim 23

AN IMAGE-RECORDING PROCESS COMPRISING CONVERTING A 2H-BENZIMIDAZOLE WITHIN A SELECTED AREAL PORTION OF A RADIATION-SENSITIVE LAYER OF A PHOTOGRAPHIC ELEMENT TO A DIHYDROBENZIMIDAZOLE BY IMAGEWISE EXPOSING THE 2H-BENZIMIDAZOLE TO ACTINIC RADIATION IN THE PRESENCE OF LABILE HYDROGEN ATOMS, REDUCING AN IMAGE-RECORDING COMPOUND CAPABLE OF CHANGING ITS RADIATION-ABSORPTION CHARACTERISTIC UPON REDUCTION WITH THE DIHYDROBENZIMIDAZOLE GENERATED WITHIN THE SELECTED AREAL PORTIONS OF THE LAYER, SAID COMPOUND BEING SELECTED FROM THE GROUP CONSISTING OF AMINOTRIARYLMETHANE DYES, AZO DYES, XANTHENE DYES, TRIAZINE DYES, NITROSO DYE COMPLEXES, INDIGO DYES, PHTHALOCYANINE DYES, TETRAZOLIUM SALTS, AND TRIAZOLIUM SALTS; AND HEATING THE LAYER TO CONVERT RESIDUAL 2H-BENZIMIDAZOLE NOT EXPOSED TO ACTINIC RADIATION TO 1H-BENZIMIDAZOLE.

Claim 24

AN IMAGE-RECORDING PROCESS COMPRISING CONVERTING A 2H-BENZIMIDAZOLE WITHIN A SELECTED AREAL PORTION OF A RADIATION-SENSITIVE LAYER OF A PHOTOGRAPHIC ELEMENT TO A DIHYDROBENZIMIDAZOLE BY IMAGEWISE EXPOSING THE 2H-BENZIMIDAZOLE TO ACTINIC RADIATION IN THE PRESENCE OF LABILE HYDROGEN ATOMS, REDUCING AN IMAGE-RECORDING COMPOUND CAPABLE OF CHANGING ITS RADIATION-ABSORPTION CHARACTERISTIC UPON REDUCTION WITH THE DIHYDROBENZIMIDAZOLE GENERATED WITHIN THE SELECTED AREAL PORTIONS OF THE LAYER, SAID COMPOUND BEING SELECTED FROM THE GROUP CONSISTING OF AMINOTRIARYLMETHANE DYES, AZO DYES, XANTHENE DYES, TRIAZINE DYES, NITROSO DYE COMPLEXES, INDIGO DYES, PHTHALOCYANINE DYES, TETRAZOLIUM SALTS, AND TRIAZOLIUM SALTS; AND HEATING THE LAYER TO CONVERT RESIDUAL 2H-BENZIMIDAZOLE NOT EXPOSED TO ACTINIC RADIATION TO 1H-BENZIMIDAZOLE.

Claim 25

An image-recording process according to claim 22 in which said radiation-sensitive layer is heated to a temperature in the range of from 100* to 150*C.

Claim 26

An image-recording process according to claim 22 in which said radiation-sensitive layer is imagewise exposed to light.

Claim 27

An image-recording process according to claim 24 in which said radiation-sensitive layer is imagewise exposed to visible light.

Claim 28

An image-recording process according to claim 24 in which said radiation-Sensitive layer is imagewise exposed to ultraviolet light.