Class of masked stabilizers in photographic materials or developing solutions
Patent 5236815 Issued on August 17, 1993. Estimated Expiration Date: August 3, 2012. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
430/448, Using processing ingredient in element430/486, Processing additive containing430/489, Antifoggant430/490, Stabilizer-preservative430/523, Identified backing or protective layer containing430/551, And antifoggant or color stabilizer430/607, Stabilizing or fog inhibiting ingredient containing430/613Heterocyclic compound
A new class of photographic masked stabilizers is disclosed showing following general chemical formula (Ia) or (Ib): ##STR1## wherein X and Y each independently represent N or CR, R being hydrogen or lower alkyl,Z represents a lower alkyl group, a nitro group, a halogen atom or hydrogen, andM represents a positive counterion, preferably an alkali cation, ammonium or substituted ammonium.The compounds are demasked by hydrolysis under alkaline conditions. They can be incorporated in a developing solution or in a photographic material, preferably in the backing layer. They show an enhanced solvability in water compared to the corresponding unmasked stabilizers.A preferred compound is 1-(2-sulphonatobenzoyl)-5-nitroindazole trimethylamine, sodium or potassium salt.
August 3, 2012. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
