| 摘要 |
NEW MATERIAL:A compound shown by the formula I or formula II (R1 and R2 are halogen, 1-5C alkyl, 1-5C alkoxyl, cyano, nitro, 2-10C alkoxyalkl; A is 1-20C alkylene, or 8-20C arylalkylene). EXAMPLE:1',1''( 1, 10-Decanediyl )bis( 1', 3'-dihydro-3',3'-dimethyl-5',8-dimethoxy-6- nitro-spiro[2H-1-benzothiopyran-2,2'-[2H]indole]. USE:A laser recording medium for optical video disc, etc. Having high absorption ability especially at about 780nm, improved stability of coloring state, capable of repeating coloring-decoloring. PREPARATION:Spiropyran of benzothiopyran is dimerized through an n-alkylene group or an arylalkylene group.
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