Positively chargeable toner for electrostatic charge image development

Abstract

This invention provides a positively chargeable toner for electrostatic charge image development which can also be used with a toner supply-type image forming apparatus and, in the supply of a toner, can realize no significant fogging and imparting of temporally stable electrification properties and fluidity to toner particles, and, even in continuous printing of a number of sheets, can realize an excellent hairline reproducibility in a print, and, even under a high-temperature and high-humidity environment, is less likely to cause a deterioration in image quality due to fogging or the like and can realize excellent print durability. The positively chargeable toner for electrostatic charge image development comprises a binder resin, colorant-containing colored resin particles, and an external additive. The external additive contains fine particles of spherical colloidal silica having a number average primary particle diameter of 30 to 80 nm and a triboelectrification amount of -50 to +300 [mu]C / g, and fine particles of fumed silica having a number average primary particle diameter of 5 to 25 nm. The content of the fine particles of spherical colloidal silica and the content of the fine particles of fumed silica are 0.3 to 2 parts by weight and 0.1 to 1 part by weight, respectively, based on 100 parts by weight of the colored resin particles.

Description

Technical field The present invention relates to a positively charged toner for developing electrostatic images used for developing electrostatic latent images in electrophotographic methods, electrostatic recording methods, electrostatic printing methods, etc. (hereinafter referred to as "positively charged toner" or "Toner"). More specifically, it relates to a positively charged toner for developing electrostatic images that can be applied to an image forming apparatus of a toner replenishment system. Background technique Image forming apparatuses such as electrophotographic devices, electrostatic recording devices, electrostatic printing devices, etc. widely adopt an image forming method that develops an electrostatic latent image formed on a photoreceptor with toner for developing electrostatic images, thereby forming a desired image. Used in copiers, printers, fax machines and their composite all-in-ones, etc. For example, in an electrophotographic apparatus using an ele...

AI Technical Summary

Problems solved by technology

However, for toners obtained by using the external additives disclosed in Patent Documents 1 to 5, although attempts have been made to improve the functions of the external additives, images that can respond to the toner replenishment methods required in recent years have not yet been achieved. high performance forming device

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