| 摘要 |
<p>PURPOSE:To solve the problem of pigment sedimentation, by fixing a part of or the whole of a pigment to hollow microspheres in microcapsule form so that the bulk specific gravity of the composition is equal to the specific gravity of a solvent, and dispersing the composition in the solvent. CONSTITUTION:For example, a Saran resin is dissolved in tetrahydrofuran to saturation, and vaporized low-temperature air from a liquid air bomb is introduced into this solution as micro-bubbles through a bubbler. The Saran resin separated by the low-temperature air is suspended in the upper part of the solution as hollow microspheres containing air, and these microspheres are taken out before redissolution to evaporate tetrahydrofuran, thus giving hollow microspheres in microcapsule form. These hollow microspheres are then mixed with a pigment containing, e.g., an adsorbed plasticizer under high- speed agitation. The mixture is dried in an air stream to fix a part of or the whole of the pigment to the hollow microspheres, and the composition thus obtained is dispersed in a solvent preferably after appropriate surface treatment (e.g., polyvinyl butyral coating) to increase the compatibility with the solvent.</p> |
