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
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-10-29 21:26
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/685
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
27 words
A light-sensitive material according to claim 1, wherein for every part by weight of photochromic compound 1/2 to 10 parts by weight of stabilizing agent are present.
Claim 2
Dependent Claim
16 words
A light-sensitive material according to claim 1, wherein the photochromic compound is 1'', 3'', 3''-trimethyl-6-nitro-spiro (2H-1-benzopyran-2,2''-indoline).
Claim 3
Dependent Claim
15 words
A light-sensitive material according to claim 1, wherein the photochromic compound is 6-bromo-1'', 3'', 3''-trimethyl-8-nitro-spiro(2H-1-benzopyran-2,2''-indoline).
Claim 4
Dependent Claim
15 words
A light-sensitive material according to claim 1, wherein the photochromic compound is 6,8 dinitro-3''-phenyl-2,2''-spirobi (2H-1-benzopyran).
Claim 5
Dependent Claim
16 words
A light-sensitive material according to claim 1, wherein the light-sensitive layer also comprises a binding agent.
Claim 6
Dependent Claim
14 words
A light-sensitive material according to claim 6, wherein the binding agent is poly-n-butyl methacrylate.
Claim 7
Dependent Claim
89 words
Process for the stabilization of a photographic image formed in a light-sensitive layer of a photochromic spiropyran compound, which comprises intimately mixing the photochromic compound before exposure to actinic light with a stabilizing agent in an amount sufficient to impart stabilization to said photochromic compound having the general formula : wherein : R1 represents hydrogen, unsubstituted phenyl or phenyl substituted 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 :