| 摘要 |
<p>PURPOSE:To obtain a photodecolorizable ink which gives written characters excellent in decolorizability under exposure to near-infrared rays and enables writing on the same part as before and decolorized by mixing a specific cationic dye having absorption in the near-infrared region, a decolorizer, and a lactone or lactam. CONSTITUTION:A photodecolorizable ink is produced by mixing a cationic dye having absorption in the near-infrared region and represented by formula I wherein D<+> is a cation having absorption in the near-infrared region; and A<-> is an anion such as a halide ion, a perchlorate ion, PF<->6, BF<->4, SbF<->6, or a sulfonate ion or formula II wherein R<1>, R<2>, R<3>, and R<4> are each alkyl, aryl, allyl, aralkyl, alkenyl, alkynyl, etc., a decolorizer represented by formula III wherein R<5>, R<6>, R<7>, and R<8> are alkyl, aryl, allyl, aralkyl, etc., (e.g. tetramethylammonium n-butyltriphenylborate), and a compd. represented by formula IV wherein n is 2-9; and X is 0 or N, e.g. beta-butyrolactone).</p> |
