| 摘要 |
<p>PURPOSE: To easily produce a low-cost high-quality toner in a very high yield by directly dyeing synthetic resin particles with a water-soluble dye in a dyeing medium under specified conditions. CONSTITUTION: Synthetic resin particles having a prescribed particle diameter or average particle diameter are dyed with a water-soluble dye under stirring in a dyeing medium made of water heated to a temp. between the softening point of the resin particles and the softening point +40 deg.C in the presence of fine anhydrous silica powder. The weight ratio of the water to the resin particles is >=5. The dyed resin particles are dehydrated and dried. When the temp. of the medium is below the softening point of the resin particles, it is difficult to dye the resin particles to the required color density or practical dyeing is not carried out because a remarkably long time is required. When the temp. of the medium is above the softening point +40 deg.C, the resin particles fuse even by dyeing under vigorous stirring to form an aggregate unfavorable for a toner.</p> |
