| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain excellent color developability and transparency even if either of recording paper and OHP is subjected to image formation by incorporating a high concn. of chromatic coloring agents, binder resins and metal oxide particulates into a master batch. SOLUTION: The master batch for color toners contg. the high concn. of the chromatic coloring agents, binder resins and metal oxide particulates is used. This master batch is obtd. by mixing raw materials, melting and kneading the mixture composed thereof and pulverizing the mixture after cooling. More specifically, the chromatic coloring agents, the binder resins and the metal oxide particles are mixed by a device, such as Henschel mixer, which acts shearing force on the material to be treated. The disintegration of the secondary flocs of the chromatic coloring agent is induced as a result of the stresses by the shearing force in this mixing stage. This mixture is then subjected to melting and kneading, then to pulverizing after cooling, by which the master batch is obtd. The large shear acts on the coloring agents in consequence of the high concn. of the chromatic coloring agents in the kneaded mixture and the coloring agents are finely dispersed in this melting and kneading stage.</p> |
