Development restrainer release compounds
AssigneePolaroid Corporation
InventorsJames R. Bartels-Keith, Anthony J. Puttick
Life of this patent
Estimating the term…
Abstract
There are described novel compounds which are represented by the formula ##STR1## wherein R is ##STR2## A is sulfur or selenium; X represents the nonmetallic atoms necessary to form a nucleus which completes a five or six membered heterocyclic moiety; R.sub.1 is H or lower alkyl; R.sub.2 is H or a hydrolyzable group; and R.sub.3 is H, alkyl or a hydrolyzable group. The compounds are useful in photographic applications and provide controlled release of a photographically useful material during processing of photographic elements with an aqueous alkaline processing composition.
Claims18
A compound represented by the formula ##STR24## wherein R is ##STR25## A is sulfur or selenium;
- X represents the nonmetallic atoms necessary to form a nucleus which completes a tetrazole moiety;
- R.sub.1 is H or alkyl having from 1 to 6 carbon atoms;
- R.sub.2 is H or a group which is hydrolyzable upon contact with an aqueous alkaline medium;
- and R.sub.3 is H, alkyl or a group which is hydrolyzable upon contact with an aqueous alkaline medium.
A compound represented by the formula ##STR35## wherein R is ##STR36## X represents the nonmetallic atoms necessary to form a nucleus which completes a five or six membered heterocyclic moiety;
- R.sub.1 is H or alkyl having from 1 to 6 carbon atoms;
- R.sub.2 is H or a group which is hydrolyzable upon contact with an aqueous alkaline medium;
- and R.sub.3 is H, alkyl or a group which is hydrolyzable upon contact with an aqueous alkaline medium.
A compound represented by the formula ##STR40## wherein R is ##STR41## A is sulfur or selenium;
- X represents the nonmetallic atoms necessary to form a nucleus which completes a five or six membered heterocyclic moiety;
- R.sub.1 is H or alkyl having from 1 to 6 carbon atoms;
- R.sub.2 is H or a group which is hydrolyzable upon contact with an aqueous alkaline medium;
- R.sub.3 is H, alkyl or a group which is hydrolyzable upon contact with an aqueous alkaline medium;
- and R.sub.4 is either a group having a pKa of from about 7 to about 14 which is ionizable to an anion whereby the silver salt of the moiety resulting from cleavage of R is more soluble in the pH range within which R.sub.4 is ionized to an anion that it is below that pH range or a precursor thereof, said precursor being capable of being converted to R.sub.4 upon contact with an aqueous alkaline medium.
Dependencies are inferred from the claim text.