NEW MATERIAL:A photochromic compound shown by formula I (R1 and R2 are H, 1W5C alkyl, alkoxy, halogen, cyano or nitro; R3 is 1W20C alkyl; R4 is H or 1W5C alkyl; R5 is H or nitro).
EXAMPLE: 1'-Hexadecyl-3',3'-dimethyl-8-carboxyl-spiro[2H-1-benzothiopyran-2,2'- indoline].
USE: Showing absorption characteristics approximately at 780nm, a wavelength range of semiconductor laser and improved color preservation. Therefore, a photochromic sensitized material using a photochromic compound is useful as a medium for reproduction of semiconductor laser record, also usable for various recording, recording material, copying material, etc., and further useful as optical filter, display material, etc.
PREPARATION: A compound shown by formula II (X- is p-toluenesulfonic acid ion, etc.,) is reacted with a compound shown by formula III in the presence of a base to give a compound shown by formula I.
ARAKAWA SEIICHI
ISHIKAWA TOMIKO
SETO NOBUYOSHI
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