| 摘要 |
PURPOSE:To form a clear image on paper by fixing and to enable the erasion of the image with a rubber eraser without leaving a mark by using a toner which adheres to paper by softening or melting at the fixing temp. and does not stick to other substance contacting with the toner such as paper after cooling to ordinary temp. CONSTITUTION:A colorant is added to one or more kinds of solid silicone varnish having 90-110 deg.C low softening point and 500-4,000mol.wt. as a binder by 1-40pts.wt. per 100pts.wt. silicone varnish, and a chargeability controller and other auxiliaries are further added by a proper amount each. They are kneaded under heating at 120-150 deg.C or dissolved in a proper solvent and kneaded. The kneaded material is crushed with a speed mill or the like and pulverized with a pulverizer by an air jet system. The resulting powder is classified to obtain a negatively chargeable powdery toner of about 5-20mum particle size for electrophotography. |
