| 摘要 |
<p>PURPOSE:To obtain a marking ink for a writing board, which can give writings easily erasable even after a long time after writing, by adding a urea to a wipable marking ink for a writing board. CONSTITUTION:0.1-10wt.%, desirably, 0.2-5wt.% urea (E) which acts as a whitening agent for component C and is selected from among urea, 1,3-dimethylurea, 1,3-diethylurea, 1,3-dibutyleneurea, ethyleneurea, etc. is added to a wipable marking ink for a writing board, comprising an alcoholic solvent and/or a glycol solvent (A) (e.g., ethanol), a coloring matter (B) (e.g., Varifast Red #1308), a natural or synthetic resin (C) soluble in component A (e.g., polyvinyl butyral resin) and, optionally, additives (D) such as a surfactant, an eraser, a dry-up preventing agent, a pH controller, a preservative and a rust inhibitor.</p> |
