| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain an ink which is easily erasable without traces regardless of the material of a writing board and the condition after writing such as whether it is just after written or completely dried, by adding an agent to give the erasing effect which is a combination of a compound selected from fatty acid esters, a silicone oil and the like and a polymer powder. SOLUTION: The ink comprises 0.5-20 wt.% of a pigment, 0.1-20 wt.% of a water soluble or dispersible resin, an agent to give the erasing effect which is a combination of 0.5-20 wt.% of a compound selected from a polyalkylene glycol monoether ester, a bis(polyalkylene glycol monoether) dicarboxylic acid ester, a polyalkylene glycol fatty acid diester, a polyglycerin fatty acid ester, a silicone oil, alkylvinyl ether, a potassium salt of a fatty acid and a pentaerythritol fatty acid ester and 0.1-10 wt.% of a polymer powder having a mean particle size of 0.05-5μm, and water.</p> |
