| 摘要 |
<p>PURPOSE:To enable characters or designs to be easily erased with conventional erasers, by mixing Aniline Black with a specified polyethylene glycol in an aq. medium and optionally in the presence of a surfactant. CONSTITUTION:Aniline black (a) is mixed with polyethylene glycol (b) having an MW of 3,000 or above in an aq. medium and optionally in the presence of a surfactant (c). When further potassium salt (d) of a fatty acid is added, the erasability of characters can be improved. The preferred mixing ratio of components is such that (a) is 5-15%, (b) is 3-20% and (d) is 0.1-10% (wt%). Pref. the concn. of component (c) in the aq. medium is 0.05-5wt%. Preferred examples of component (c) are nonionic and anionic surfactants.</p> |
