| 摘要 |
PURPOSE:To form positive-electrifiable magnetic material particles by depositing a copolymer of a monomer contg. a specific amino group and vinyl monomer copolymerizable with the monomer on the surface of the magnetic material particles thereby forming a coating layer. CONSTITUTION:A copolymer in which the copolymn. ratio of the unsatd. amide monomer contg. a tertiary amino group as shown in the formula is 0.5-50wt% is dissolved in an org. solvent and after magnetic material particles are dispersed into such soln., org. solvent is dried and evaporated away to form a copolymer layer like a film on the surface of the particles. The positive-electrifiable magnetic material particles produced in such a way are useful as a positive-electrifiable magnetic toner and positive-electrifiable carrier for electrophotographic development. Since said particles have a positive electrifying characteristic, the particles are suitable for an ordinary electrophotographic system in which the surface of a photosensitive body such as a cadmium sulfide photosensitive body or org. photosensitive body is negatively electrified and the copied image having good image quality is obtd. irrespectively of environmental conditions for copying and storage conditions for the toner. |
