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US 5,312,721 AGranted
Bleachable antihalation system
AssigneeE. I. Du Pont de Nemours and Company
InventorIngrid Gesing
Life of this patent
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Abstract
The invention involves a bleachable antihalation system, particularly for use in thermally developable photographic recording materials. This antihalation system contains, besides an antihalation dye, a bleaching agent that forms sulfurous acid or sulfurous acid derivatives on treatment with heat or irradiation with actinic radiation.
Claims11
A bleachable antihalation system containing
- (a) a bleaching agent which is 2,4-diaryl-substituted 1,2,3,5-oxathiadiazole-2-oxide, wherein said aryl groups are unsubstituted or independently of each other substituted by at lest one substituent selected from the set consisting of alkyl, aryl, ether, ester, halogen, hydroxy, cyano, amino, carbonyl, carxboxyl, carbamoyl, sulfonyl groups, carbocyclic and heterocyclic annular ring, and
- (b) an antihalation dye which is triphenylmethane, quinone imine or oxonol dye with the proviso that said system upon exposure to heat, actinic radiation, or combination thereof, said bleaching agent forms at least one of sulfurous acid, derivitized sulfuric acid or sulfur dioxide.
Dependencies are inferred from the claim text.