| 摘要 |
<p>PURPOSE:To provide the titled ink compsn. which has sufficient erasability and exhibits excellent writing stability over a long period of time, by blending rubber, a solvent, a pigment, a conditioner, and a lubricant in a specified ratio. CONSTITUTION:16-22wt% (based on the total amount of the compsn.) rubber (A) such as natural pale crepe rubber or synthetic cis-1,4-polyisoprene rubber having a Mooney viscosity of 20-26, a low-boiling rubber solvent (B) in an amount of 1.3-1.8 times that of the rubber, such as petroleum naphtha or isoparaffin, a pigment (C) in an amount of 0.8-1.1 times that of the rubber, such as carbon black or org. azo dye, a conditioner (D) in an amount of 1.5-1.8 times that of the pigment, such as dioctyl phthalate or mineral oil having a b.p. of 300 deg.C or higher, and an appropriate amount of a lubricant (E) such as fatty acid or nonionic surfactant are blended together.</p> |
