Minnesota Mining and Manufacturing Company

Antonio Luzzi

Ivano Delprato

Piero Ramello

Stefano Mana

Marco Beruto

An infrared sensitive silver halide photographic element which contains a dye represented by the following formula: ##STR1## wherein R.sub.1 and R.sub.2 each independently represent a sulfoalkyl or a sulfatoalkyl group having 2 to 4 carbon atoms, Q represents the atoms necessary to complete a 5- or 6-membered carbocyclic ring group, R.sub.3 represents an alkyl group, R.sub.4 represents an aryl group, X.sup.- represents an anion, n is an integer of 1 or 2, provided that that n is 1 when the dye forms an intramolecular salt, and Z.sub.1 and Z.sub.2 each independently represent the atoms necessary to complete an indole nucleus.

Silver halide photographic elements with infrared absorbing dyes

An infrared sensitive silver halide photographic element which contains an infrared-absorbing dye represented by the following formula ##STR1## wherein: R.sub.1 and R.sub.2 each independently represents a sulfoalkyl or a sulfatoalkyl group,

Silver halide photographic elements

A photographic material for tanning development which comprises a photographic support base, at least one tannable binder material, at least one silver halide emulsion and at least one pigment, said material including a 3-pyrazolidone compound and at least two different 1,4-dihydroxybenzene compounds, the first of which is chosen within the group of those having a standard tanning development time (STDT) of one fourth to twice the hydroquinone STDT (STDTHy) and the second of which is chosen within the group of those having a STDT of one fourth to fifteen times the STDTHy. Most preferably, the above photographic material includes hydroquinone in addition to the 3-pyrazolidone compound and the two 1,4-dihydroxybenzene compounds, wherein the first 1,4-dihydroxybenzene compound, other than hydroquinone, is chosen within the group of those having a STDT of one fourth to twice the STDTHy and the second 1,4-dihydroxybenzene compound is chosen within the group of those having a STDT of two to fifteen times the STDTHy. A method to obtain relief images by using the above said photographic material.

Photographic material for tanning development and method for obtaining a

Silver halide photographic elements for tanning development including tanning developers, which can diffuse into the gelatin layer containing them, can be improved if they are associated with non-diffusing hydroquinones. In the case where such tanning developer is hydroquinone or a derivative thereof, said elements include such diffusing hydroquinone associated with a hydroquinone derivative non-diffusing in the gelatin layer containing it. Such non-diffusing hydroquinones preferably are hydroquinones substituted with aliphatic chains containing a total of at least twelve carbon atoms and, more preferably, are dispersed in the layer dissolved in a high-boiling organic solvent.

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Savona, Italy

Antonio Luzzi