| 摘要 |
PURPOSE:To extremely raise dye solubility and to attain high quality by preparing a dye solvent for pressure-sensitive copying paper with hydrogenated phenanthrene and/or hydrogenated anthracene as a main constituent. CONSTITUTION:The hydrogenated phenanthrene and/or hydrogenated anthracene is finely distilled within a range of 250 to 350 deg.C to obtain the dye solvent having a prescribed nitrogen concentration for pressure-sensitive copying paper. The desirable hydrogenated phenanthrene or hydrogenated anthracene is prepared as follows: crystal-free anthracene oil which is obtained by distilling coal tar and has a nitrogen concentration of about 8000ppm, or anthracene oil is hydrogenated to 1 to 8 degree of hydrogenation to reduce the nitrogen concentration to 1000ppm or below. It is desirable that crystal-free anthracene oil or anthracene oil is distilled, acid-cleaned and extracted, or is subjected to their combined treatment before hydrogenation. |
