Toner, two-component developer, developing device, and image forming apparatus

Abstract

A toner in which even a toner containing crystalline polyester exhibits excellent fixing property, chargeability, color reproducibility, and long-term stability, as well as a two-component developer, a developing device, and an image forming apparatus are provided. The toner includes toner base particles which contain a colorant and a binder resin containing at least crystalline polyester and an amorphous resin; and a mixed oxide of aluminum oxide and silicon dioxide externally added to the toner base particles, and the toner is so adjusted that the binder resin contains 20% by weight to 50% by weight of the crystalline polyester and that a compositional proportion of aluminum oxide in the mixed oxide of aluminum oxide and silicon dioxide falls within a range of 35% by weight or more and less than 50% by weight.

Description

technical field [0001] The present invention relates to a toner, a two-component developer, a developing device, and an image forming device. Background technique [0002] In recent years, image forming apparatuses using electrophotography such as electrostatic copiers and laser printers, especially image forming apparatuses capable of full-color printing, have rapidly become popular. [0003] An image forming apparatus using electrophotography refers to an apparatus that forms an image on a recording medium such as paper or a sheet through a charging process, an exposure process, a development process, a transfer process, and a fixing process. In the charging step, the surface of the photoreceptor is uniformly charged. In the exposure step, an electrostatic latent image is formed on the surface of the photoreceptor by exposing the charged photoreceptor. In the developing step, a developer is made to adhere to the electrostatic latent image formed on the surface of the pho...

AI Technical Summary

Problems solved by technology

[0012] In Japanese Patent Application Laid-Open No. 2002-287426, in a toner containing a crystalline polyester having a low chargeability, since no consideration is given to controlling the charge amount by an external additive, the long-term stability of the charge amount may deteriorate

[0013] In Japanese Patent Application Laid-Open No. 4-452, since titanium oxide that deteriorates the transparency of the toner is used, and the chargeability and color reproducibility of the toner are not considered, the use of titanium oxide containing Color reproducibility may be poor in the case of color toners of crystalline polyesters with poor transparency

[0014] Since the technology disclosed in Japanese Patent Application Laid-Open No. 2001-83731 does not consider toners containing crystalline polyesters, when using toners containing crystalline polyesters with low chargeability, even when using the disclosed mixture The non-crystalline silicon-aluminum co-oxide powder with adjusted ratio may also deteriorate the long-term stability of charge

[0015] In Japanese Patent Application Laid-Open No. 2001-166537, polylactic acid resin, which is a crystalline polyester, is used, but since the dispersibility of the crystalline polyester is not considered, good fixing properties may not be obtained

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