| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an oil-base erasable ink composition for a marking pen, which can give writing of a uniform density of blackness on a white board even after a long-term storage. SOLUTION: This composition comprises at least one organic solvent (a) selected among a 2-4C lower aliphatic alcohol, an ethylene glycol monoalkyl ether with a 1-3C alkyl and a propylene glycol monoalkyl ether with a 1-3C alkyl, carbon black (b), a polyvinyl butyral resin (c), at least one erasability improver (d) being a liquid soluble in the organic solvent and normally difficulty evaporable or substantially non-evaporable and selected among fatty acid esters, higher hydrocarbons, higher alcohols, polyoxyethylene ether phosphoric esters, polyoxyethylene ether sulfuric esters, etc., and at least one amine- or amide-type surfactant (e) selected among oxyethylene alkylamines, polyoxyethylenealkylamines, oxyethylenelakyldiamines, etc.</p> |
