Production method of two-component developer

Abstract

The invention provides a two-component developer. The two-component developer can prevent breakage of toner particles, burying of external additives and breakage of carrier particles through lightweight of a resin coated carrier even under violent agitation in high speed printing. The invention provides a production method of the two-component developer. The method for making the resin coated carrier with a porous magnetic core particle comprises: blocking the pit apertures of the porous magnetic core particle surface with rubber particles for forming a carrier intermediate body, and coating resin on the surface of the carrier intermediate body for making the resin coated carrier.

Description

Technical field [0001] The present invention relates to a method for manufacturing a two-component developer used for image formation in electrophotographic mode, in particular to a method for manufacturing a two-component developer with a resin-coated carrier, which is made of a magnetic core material The particles are coated with resin, and the magnetic core material particles cover the fine pores on the surface with rubber particles. Background technique [0002] Developers that can be applied to image forming devices such as photocopiers and printers of the electrophotographic method include one-component developers consisting of toner alone, and two-component developers consisting of toner and magnetic powder called carrier Sub-developer. When an image is formed using a two-component developer, the toner can be quickly charged due to the presence of a carrier, which is advantageous for high-speed printing. [0003] As described above, the carrier used in the two-component de...

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Problems solved by technology

[0005] However, in electrophotographic image forming apparatuses, the agitation in the developing device becomes stronger with the increase in the speed of printing and the miniaturization of the apparatus, and the impact on the developer caused by the vigorous agitation is also increasing.

For example, when stirring, the collision between the toner and the carrier becomes severe, and the toner particles are damaged under the impact, and the external additives are buried, and the charging of the toner cannot reach the specified level.

As a result, the following problems will occur: image defects such as fogging (caburi) or poor transfer due to poor charging of the toner, or degradation of the charging performance due to toner crushed matter adhering to the surface of the carrier particles, and further In-flight pollution caused by the presence of flying objects

However, in the magnetic powder dispersion type carrier, since the binder resin coats the magnetic powder, the impedance of the carrier is high, the toner cannot be charged sufficiently, and it is difficult to form a toner image with sufficient image density.

In addition, during high-speed printing, etc., the impact caused by stirring can cause resin peeling and magnetic powder detachment, which in turn hinders stable toner image formation

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