Image forming toner, and developer and process cartridge using the toner

Abstract

An image forming toner, includes a mother particle including a paraffin wax having a melting point of from 60 to 90 DEG C. and a binder resin, wherein the mother particle has an endothermic peak of the paraffin wax of from 2.0 J / g to 5.5 J / g when measured by a DSC and an aspect ratio of from 0.8 to 0.90.

Description

Technical field [0001] The present invention relates to a toner that is used as a toner for developing electrostatic latent images in electrophotography, electrostatic recording, and electrostatic printing. The present invention also relates to development using the toner Agent and processing cartridge. Background technique [0002] Recently, the market demand for high image quality and energy saving has accelerated the development of suitable developing toners and developers. The suitable toner mainly has a small particle size and a narrow particle size distribution. Individual toner particles with a narrow particle size distribution can have consistent actions during development and can perform well on dot images. As a method of preparing such a toner with a narrow particle size distribution, Recently, a polymerization method has been used. This polymerization method can be exemplified by suspension polymerization, emulsion polymerization to easily change the toner into a diff...

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Problems solved by technology

[0003] In order to fix the toner at a low temperature, polyester resins with good low-temperature fixability and heat-resistant fixability are used instead of traditionally used styrene / acrylic resins. In order to further improve low-temperature fixability, there are It is necessary to control the thermal properties of the resin. However, if the resin has an excessively low glass transition temperature (Tg), the heat-resistant storage of the obtained toner will deteriorate. For example, the softening temperature of the resin [T(F1 / 2 )], the thermal offset of the obtained toner will become lower. Therefore, it has not been made to have good low-temperature fixing and high thermal offset occurrence temperature. Further, since the developer needs to undergo long-term Image formation and long-term stirring, the release agent in the toner and the polyester resin with a low melting point will adhere to the carrier, which will deteriorate the charging ability of the carrier, thereby causing the charging of the developer volume becomes low.

[0004] If silica as a flow agent does not adhere well to the toner with unevenness, it will move to the concave portion of this toner, and such toner will easily contaminate the photoreceptor and adhere to the fixing roller. Although there is an advantage in using a polyester resin that can be fixed at a low temperature, since the solution-suspension method adds a polymer material to the solution or suspension of the resin and the colorant in order to improve the releasability of the resulting toner, resulting in An oil-free fixing toner. As a result, the solution or dispersion has a high viscosity, and the productivity becomes low. Japanese Patent Laid-Open No. 9-15903 discloses a preparation for developing an electrostatic latent image A method for a toner comprising, dissolving a binder resin and a colorant in a solvent that is not miscible with water to prepare a composition; preparing the prepared composition in the presence of a dispersion stabilizer A step of dispersing in an aqueous solvent to form a suspension; a step of removing the solution by heating and / or reduced pressure to form particles having a concave-convex surface; and a step of spheroidizing or deforming the particles. However, obtaining The toner is irregular and amorphous, so it cannot be stably charged, and there is no polymer design to make it have basic life and fractal properties.

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