| 摘要 |
PURPOSE:To identify whether a foam can be used for an ink reservoir, by a method wherein the cleanness of the foam is specified according to at least one of a test for deciding a nonvolatile residue level and a test for deciding a surface tension. CONSTITUTION:A foam is exposed to a solvent and extracted without being affected. After the solvent is evaporated, a residue is weighed to be compared with an initial weight of the extracted foam. The weight due to the solvent in the weight of the residue is subtracted from the weight of the foam residue. If the amount of the NVR contained in the foam is less than about 0.2wt.%, a proper cleanness to a specially coated paper is ensured. On the other hand, a surface tension is determined by dipping the foam in a liquid component used for preparing an ink. The surface tension is measured before and after the dipping. With respect to an ink prepared for specially coated papers, a final surface tension more than approximately 40 dyne/cm makes a foam satisfactory in cleanness. With respect to an ink prepared for plain papers, the reduction of the surface tension should be not more than approximately 7 dyne/cm. |
