摘要:
An encapsulated toner is provided by coating core particles with an outer shell. The outer shell comprises, as predominant components thereof, vinyl polymers A and B of different molecular weights. More specifically, the ratio of the number-average molecular weight of the vinyl polymer A (Mn.sub.A) to that of the vinyl polymer B (Mn.sub.B) is in the range of 2 to 15. The vinyl polymers A and B respectively have a ratio of weight-average molecular weight to number-average molecular weight of 5 or less. Because of these specific molecular weight characteristics of the shell-constituting polymers, the durability and triboelectric charging characteristics of the encapsulated toner are improved. These effects are enhanced particularly when inorganic fine particles are attached to embedded in the surface or surface layer of the core particles.
摘要:
An encapsulated toner for development of electrical latent images comprises a core particle containing a colorant and a soft solid material, inorganic fine particles attached to the vicinity of the surface of the core particle, and a shell coating the core particle and the inorganic fine particles. The inorganic fine particles function to, e.g., reinforce the encapsulated toner with a thin shell and may be attached to the core particles through dry-mixing. The core particles with the attached inorganic particles may be coated with a shell resin through phase separation.
摘要:
A mixture of a colorant, and a binder compound having an aliphatic hydrocarbon long chain and having a relatively low melt viscosity, is kneaded in a molten state in the presence of solid media such as balls or beads to form a uniform mixture in which the colorant particles or aggregates have been disintegrated to a size of 5 .mu. or below. Solid particles which may be used as a toner are formed from the uniform mixture and may be encapsulated, as desired, to provide a capsule toner.
摘要:
A core material comprising a binder mixture of a long chain organic compound and an ester of a higher alcohol and a higher carboxylic acid is encapsulated with a thin shell material to give an encapsulated toner. The encapsulated toner has a uniform structure and a narrow particle size distribution and is excellent in developing and fixation characteristics, when used in electrophotography, etc.
摘要:
A capsule toner, comprising core particles of a core material exhibiting a cloud point within the range of from 30 to 90 and a penetration within the range of from 2 to 15, and a shell material coating the core particles. The capsule toner is preferably formed by dispersing the core particles in solution of the shell material in a good solvent for the shell material, and then adding a poor solvent for the shell material to cause the deposition of the shell material on the core particles.
摘要:
A pressure-fixable capsule toner for electrophotography having characteristics such as good combination of fixability and durability and also a stable charge controlling characteristic is provided. The core materials typically are of polyethylene or paraffin wax. The shell material is a vinyl polymer characterized by low molecular weight distribution represented by a ratio of weight-average molecular weight/number average molecular weight of not larger than 3.5. The vinyl polymer is preferably a copolymer of styrene or a derivative thereof and a tertiary amino-group containing vinyl monomer.
摘要:
A microcapsule toner having a colored core material coated successively with a first resin wall and a second resin wall can be provided with both excellent pressure fixing characteristic and physical stability when the first resin wall has affinity to both the core material and the second resin wall, and can suitably be used for electrophotography, electrostatic printing, etc.
摘要:
A microcapsule toner for pressure fixing, comprising a core material containing a pressure-fixable component and a magnetic material, a first shell layer comprising a formaldehyde copolymer resin and a second shell layer comprising a polymer soluble in an organic solvent provided successively by coating therearound. This microcapsule, since a pressure-fixable core material is successively coated with a lipophobic first shell layer and a lipophilic second shell layer, has well-balanced pressure fixing characteristic and developing characteristic without core material exposed on the surface.
摘要:
The present invention provides a process for producing a toner having little remaining polymerizable monomer in it by suspension polymerization. During the latter half of the polymerization reaction, the remaining polymerizable monomers and the aqueous medium are evaporated or removed while supplying the aqueous medium, saturated vapor of the aqueous medium, saturated vapor of a water-soluble solvent, or water-soluble gas to maintain the ratio of solid-liquid constant.