Stabilization of photographic spiropyran compounds
Abstract
Abstract Photographic images formed in a layer of photochromic material upon exposure to actinic light are stabilized so that a more permanent image is obtained by intimately mixing the photochromic material with a stabilizing agent of the formula: WHEREIN: R1 represents hydrogen, phenyl or phenyl substitute by at least one substituent taken from hydroxyl, carboxyl, halogen, amino, nitro, methoxy, aryloxy, pyridyl and quinone diazide groups, or wherein R1 represents a substituent of the formula: WHEREIN: X stands in ortho, meta or para-position with respect to the free bond of the phenyl group and represents -O.SO2-, -NH-SO2-, -O-CO- or -NH-CO- and Y is nitro or methoxy; R2 and R3 represent a phenyl or naphthyl group carrying at least one hydroxyl, methylamino, naphthoquinone-diazidesulphonyloxy or -2-methyl-indolyl group; or R2 and R3 together with the common carbon atom form a di- or tri-phenyl-methane compound with ring closure over an oxygen atom, a sulphur atom, a sulphodioxide group or a substitute or unsubstituted nitrogen atom.
Inventors
- 👤 Albert Lucien Poot
Bibliographic Details
Claims Analysis
Total Claims: 7References Cited (Backward Citations)
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