Ballasted optical brighteners
AssigneeEastman Kodak Company
InventorsAnthony Adin, Pranab Bagchi
Life of this patent
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Abstract
An inexpensive, ballasted optical brightener for use in photographic elements is prepared by reacting an optical brightener of the formula ##STR1## where M is a cation; X is a group capable of undergoing nucleophilic displacement; and Z is ##STR2## or --O--R.sub.3, where each of R1 and R2 is a hydrogen atom, or an aromatic group which can be unsubstituted or substituted with one or more groups unreactive towards X; and R3 is an aromatic group which can be unsubstituted or substituted with one or more groups unreactive towards X with a water soluble polymer, such as gelatin. The resulting ballasted optical brightener is stable in aqueous photographic compositions.
Claims4
A ballasted water-soluble optical brightener of the formula:
- ##STR15## wherein Polymer is a gelatin residue;
- M is a cation;
- X is a group capable of undergoing nucleophilic displacement;
- and Z is ##STR16## or --O--R.sub.3, where each of R.sub.1 and R.sub.2 is a hydrogen atom, or an aromatic group which can be unsubstituted or substituted with one or more groups unreactive towards X;
- and R3 is an aromatic group which can be unsubstituted or substituted with one or more groups unreactive towards X.
An optical brightener which has the formula:
- ##STR17## where Gel is a gelatin residue.
Dependencies are inferred from the claim text.