| 摘要 |
PURPOSE:To make solution stability and corrosion resistance compatible by allowing an organic coloring matter to be dissolved in a mixture of a solvent which does not virtually dissolve a resin substrate and a solvent where the vapor pressure is higher than that of the above-mentioned solvent and which dissolves the resin substrate and to be coated. CONSTITUTION:An organic coloring matter is dissolved in a mixed solvent of a solvent (1) which has a vapor pressure of 60mmHg or less at room temperature and does not virtually dissolve a resin substrate 1 and a solvent (2) which has a vapor pressure which is higher than that of the solvent (1) at room temperature and does not dissolve the resin substrate 1, and is coated. When the steam pressure at room temperature exceeds 60mmHg, evaporation of the solvent at the time of coating the mixed solvent is excessively fast, thus causing a non-uniform coating film to be formed and preventing a uniform coating film from being obtained unless an extremely troublesome and special operations such as coating at a low temperature or that under solvent vapor atmosphere. When the above pressure is lower than that of the solvent (1) which virtually does not dissolve the substrate, inconveniences of melting property of the organic coloring matter for the mixed solvent being not sufficient or clouding is generated by the resin substrate being attached at the time of coating. |
