| 摘要 |
PURPOSE:To improve developing performance, etc., by reacting a compd. having a carboxylic group with a magnetic material. CONSTITUTION:A compd. having a carboxylic acid or its salt, and a weight average mol.wt. of 300-1,000 with a magnetic material to cover its surface. When a toner is prepared by the suspension polymn. method, since the suspended toner particles are formed in an aq. dispersion medium, and when OH groups remain on the surface of the magneitc material, it concentrates on the surface, and adhesion of the material to the toner particles is made unfavorable, and the material is also released from the surfaces of the toner particles by mechanical shearing stress in a developing machine. Said coated magnetic material is used for the toner to be prepared by the suspension polymn. method, the magnetic material is contained in the inside of the toner particles to raise insulation property, and the toner can be used as the insulating toner as it is. It can also be made a conductive toner by adding a fine conductive powder. |
