| 摘要 |
PURPOSE:To improve dispersion stability, electric charge stability, and fixability and to obtain a high density by incorporating specific polymer particles which are substantially insoluble in a hydrocarbon medium having a high insulating characteristic and a specific copolymer which is soluble in the medium in said medium. CONSTITUTION:Copolymer particles A which contain a vinyl acetate and an addition polymerizable heterocyclic compd. having nitrogen atom in the ring and are substantially insoluble in a hydrocarbon medium having a high insulating characteristic, a copolymer B which is soluble in a medium contg. an adition polymerizable compd. having a carboxylic group, a coloring dye C, and an electric charge control agent D are incorporated into said medium. N-vinyl imidazole N-vinyl-2-methyl imidazole, N-vinyl-2- ethyl imidazole, etc. are used as the addition polymerizable heterocyclic compd. having nitrogen atom in the ring. The copolymer B soluble in the medium contains an addition polymerizable monomer having a carboxylic group, for example, an acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, etc. as a copolymer component. Org. solvent having a low dielectric constant and a high electrical insulating characteristic, for example, normal paraffinic hydrocarbon, isoparaffinic hydrocarbon, alicyclic hydrocarbon, arom. hydrocarbon, halogenated aliphat. hydrocarbon, etc. are used. |
