| 摘要 |
<p>Transparent drawing paper for drawing with India ink contains quat. NH4 cpds. (I), pref. alkyl dimethyl benzyl ammonium chlorides, (I'), worked into paper-surface, esp in 0.5 g/m2 concn. (w.r.t. dry matl.). The paper is for automatic copying. A highly opaque India ink film can be obtd., yielding higher accuracy and shaper outlines in drawing with same instruments and richer contrast in reprodn., e.g. by diazo-copying.</p> |
