Photographic processing compositions including hydrophobically modified thickening agent
AssigneePolaroid Corporation
InventorsRobert D. Eckert, Daniel D. Huang, Francis M. Pierce
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Abstract
Photographic processing compositions comprising an aqueous alkaline medium and a hydrophobically modified thickening agent are disclosed. The subject thickening agent increases the viscosity of the processing composition while maintaining a relatively uniform homogenous mixture of the constituents thereof. The subject processing compositions are useful in photographic diffusion transfer film units and processes.
Claims13
A photographic processing composition comprising an aqueous alkaline medium having a pH in excess of 10 and including a thickening agent therein, said thickening agent comprising a copolymer polymerized from a monomer system comprising:
- (a) carboxylic acid monomers, the same or different, selected from the group consisting of:
- acrylic acid, methacrylic acid, ethacrylic acid, propacrylic acid and butacrylic acid;
- and
- (b) hydrophobe monomers, the same or different, represented by the formula:
- ##STR10## wherein R.sup.1 is selected from hydrogen and alkyl having from 1 to 4 carbon atoms;
- and X is selected from --O--R.sup.2 and --NR.sup.3 R.sup.4 wherein R.sup.2 is selected from:
- aralkyl, alkaryl and alkyl wherein said alkyl portion of each group comprises from 8-30 carbon atoms;
- R.sup.3 is selected from methyl and hydrogen;
- and when R.sup.3 is methyl, R.sup.4 is an alkyl group consisting of 1-18 carbon atoms;
- and when R.sup.3 is hydrogen, R.sup.4 is a tertiary alkyl group consisting of 4 to 18 carbon atoms wherein the carbon atom of attachment of said alkyl group is tertiary.
Dependencies are inferred from the claim text.