Preparation of photographic silver halide emulsions
AssigneeAGFA-Gevaert N. V.
InventorsLuc Achiel De brabandere, Robert Joseph Pollet, Herman Alberik Pattyn, Hendrik Alfons Borginon
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Abstract
In the preparation of silver halide emulsions silver halide grain-growth is accelerated by the addition to the precipitation medium during or before silver halide precipitation of a compound of the formula ##STR1## wherein: N IS AN INTEGER FROM 1 TO 5 R.sup.1 is C.sub.1 -C.sub.5 alkyl or substituted alkyl R.sup.2 is hydrogen or C.sub.1 -C.sub.5 alkyl or substituted alkyl, or a carboxylic acyl group R.sup.3 is hydrogen or C.sub.1 -C.sub.5 alkyl or substituted alkyl, and R.sup.4 is hydrogen or C.sub.1 -C.sub.5 alkyl or substituted alkyl group, aryl or substituted aryl or a salt-forming cation.
Claims13
A method for preparing a silver halide emulsion which comprises the step of precipitating silver halide grains in an aqueous solution of peptizer and adding to the peptizer solution a silver halide grain ripener to accelerate grain growth wherein before or during precipitation from about 500 mg to about 30 g of a silver halide grain ripener corresponding to the following formula is added to the peptizer solution per mole of silver halide to be formed:
- ##STR4## wherein:
- n is an integer from 1 to 5
- R.sup.1 is a C.sub.1 -C.sub.5 alkyl group
- R.sup.2 is hydrogen, a C.sub.1 -C.sub.5 alkyl group or a carboxylic acyl group
- R.sup.3 is hydrogen, a C.sub.1 -C.sub.5 alkyl group or substituted alkyl, and
- R.sup.4 is hydrogen, a C.sub.1 -C.sub.5 alkyl group, an aryl group or a salt-forming cation.
Dependencies are inferred from the claim text.