Color photographic recording material containing non-diffusing electron donor precursor compounds
AssigneeAgfa-Gevaert
InventorsWolfgang Lassig, Ernst Meier, Siegfried Schleger
Life of this patent
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Abstract
5- or 6-membered .alpha.-lactones of phenolic compounds, in which the phenyl ring carries a hydroxyl or amino group in its 2- or 4-position to the lactonized phenolic hydroxyl group and in which the lactone ring carries an electron accepting substituent, so that the lactone ring is readily cleavable at pH values of from 10 to 13 to form an electron donor compound (ED-compound) having a redox potential of less than +0.255 V determined against a normal calomel electrode at pH 0 are useful ED precursor compounds for non-diffusing reducible color providing compounds.
Claims7
Color photographic recording material having at least one light-sensitive silver halide emulsion layer and, associated thereto, a non-diffusing electron donor precursor compound (ED precursor compound) from which a non-diffusing ED compound is formed under alkaline development conditions, wherein the improvement comprises said ED precursor compound is a compound of the following general formula ##STR11## in which R.sup.1 represents a carbocyclic or heterocyclic aromatic group,
- R.sup.2, R.sup.3 and R.sup.4 which may be the same or different substituents, represent hydrogen, alkyl, alkenyl, aryl, alkoxy, alkylthio or amino, or
- R.sup.3 and R.sup.4 together complete a condensed carbocyclic ring,
- and at least one of the substituents R.sup.1, R.sup.2, R.sup.3 and R.sup.4, contains a ballast group having 10 to 22 carbon atoms which confers diffusion resistance.
Color photographic recording material having at least one light-sensitive silver halide emulsion layer and, associated thereto, a combination of a non-diffusing, reducible color providing compound which in its reduced and under alkaline development conditions releases a diffusing dye or dye precursor compound, and a non-diffusing electron donor precursor compound (ED precursor compound) from which a non-diffusing electron donor compound (ED compound) is formed under alkaline development conditions, which ED compound reduces the non-diffusing, color providing compound under alkaline development conditions wherein the improvement comprises said ED precursor compound is a compound of the following general formula:
- ##STR12## in which R.sup.1 represents a carbocyclic or heterocyclic aromatic group,
- R.sup.2, R.sup.3 and R.sup.4 which may be the same or different substituents, represent hydrogen, alkyl, alkenyl, aryl, alkoxy, alkylthio or amino, or
- R.sup.3 and R.sup.4 together complete a condensed carbocyclic ring,
- and at least one of the substituents R.sup.1, R.sup.2, R.sup.3 and R.sup.4 contains a ballast group having 10 to 22 carbon atoms which confers diffusion resistance.
Dependencies are inferred from the claim text.