Carrier for use in developer developing electrostatic image and developer using the carrier

Abstract

The carrier includes a particulate core material having magnetism; and a resin layer located on the surface of the particulate core material. The resin layer is prepared by forming a layer including a copolymer, which includes a unit (A) having a specific acrylic siloxane structure, a unit (B) having a specific acrylic silicone structure having a crosslinking ability, and a unit (C) having a specific acrylic structure in a specific ratio, on the particulate core material, and then subjecting the layer to a heat treatment to crosslink the layer.

Description

technical field [0001] The present invention relates to a carrier for an electrostatic image developer used for a two-component developer used in an electrophotography method and an electrostatic recording method, a developer using the carrier, an image forming method using the developer, an image forming apparatus, and Disposal cartridges. Background technique [0002] In order to develop an electrostatic latent image, a dry developing method used in electrophotography is to electrostatically adhere powder toner that rubs against a triboelectric charge imparting member to the electrostatic latent image to form a visible image. [0003] The dry developing method includes a so-called one-component developing method containing only toner as a main component, and a glass ball, or a magnetic carrier, or a coated carrier whose surface is coated with a resin, etc., mixed with the toner. The so-called two-component development method. [0004] The two-component developer used in ...

AI Technical Summary

Problems solved by technology

[0011] However, in recent years, due to the demand for high image quality, there is a tendency for the particle size of toner particles to be reduced, and the printing speed is increased, and it is more likely to cause spent toner to adhere to the carrier.

In addition, in the case of a developer in which wax is contained in the toner to facilitate maintenance, the amount of spent toner is very large, and the current situation is that the remaining amount of toner charge is low, toner scattering, and background smearing are low.

In order to obtain a durable carrier coating, it is effective to strongly coat the core material with a resin material with low surface energy, but generally, it tends to be difficult to coat the core material strongly with a resin material with low surface energy

For stronger coating, for example, sintering coating at higher temperature or cross-linking / hardening can be considered as in the processing of polytetrafluoroethylene (registered trademark). The constraints of the Curie point of the material (may be detrimental to the magnetism), unlike the cladding in other fields, cannot be used casually

[0012] In a color electrophotographic system, if the toner of the carrier is worn out or the coating film is worn or peeled off, the resistance of the carrier or the amount of developer uptake changes, and the image density, especially the density of the halftone portion, changes. The color toner (especially yellow toner) is stained due to filler drop-off, etc., and it is difficult to maintain high image quality at present.

[0013] In addition, depending on the usage environment, the charge amount of the developer changes, and the image density and image quality change are also important issues.

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