POSITIVE CHARGING SILICA PARTICLE AND PRODUCTION METHOD THEREOF

PROBLEM TO BE SOLVED: To solve the problem associated with conventional positive charging silica particles in which plus charging is gradually reduced as being used as a toner external additive, due to mechanical stress by repeated contact with a toner for a long time, and due to thermal stress from...

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Bibliographic Details
Main Authors KOMATSUBARA TANCHI, YAMANO TOMOYA, MORI AKIYOSHI
Format Patent
LanguageEnglish
Japanese
Published 04.02.2016
Subjects
CHEMISTRY
CINEMATOGRAPHY
COMPOUNDS THEREOF
ELECTROGRAPHY
ELECTROPHOTOGRAPHY
HOLOGRAPHY
INORGANIC CHEMISTRY
MAGNETOGRAPHY
METALLURGY
NON-METALLIC ELEMENTS
PHOTOGRAPHY
PHYSICS
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Summary:PROBLEM TO BE SOLVED: To solve the problem associated with conventional positive charging silica particles in which plus charging is gradually reduced as being used as a toner external additive, due to mechanical stress by repeated contact with a toner for a long time, and due to thermal stress from long storage under a high temperature and high humidity environment, in a developer, and charging of the silica particle returns to minus charging original to the silica, resulting in insufficient long charging stability; and provide a novel positive charging silica particle that is excellent in long charging stability and can maintain stable image characteristics as the toner external additive.SOLUTION: A positive charging silica particle according to this invention is a surface-treated silica particle in which a group including an amino group and a hydrophobic substituted silyl group are introduced to a surface by covalent binding, and at least a part of the surface is coated by a silicon oil.SELECTED DRAWING: None 【課題】 正帯電性シリカ粒子は、トナー外添剤として使用していくうちに、現像機内において、長期に渡り繰り返しトナーと接触することによる機械的ストレスや、高温高湿環境下での長期保管による熱的ストレスによって、次第にプラスの帯電を失い、シリカ本来のマイナスの帯電に戻ってしまうという、長期帯電安定性に課題が残されていた。本発明は、従来の正帯電性シリカ粒子について上記の課題を解消したものであり、長期帯電安定性に優れ、安定した画像特性を維持することが可能なトナー用外添剤としての正帯電性シリカ粒子を提供することである。【解決手段】 アミノ基含有基と、疎水性の置換シリル基とが夫々共有結合により表面に導入されてなる表面処理シリカ粒子であって、さらにその表面の少なくとも一部がシリコーンオイルで被覆されてなることを特徴とする正帯電性シリカ粒子である。【選択図】 なし
Bibliography:Application Number: JP20140143812