TONER

• Main Authors: NISHIKAWA KOJI, HOTTA YOJIRO, TERAUCHI KAZUO, YAMAZAKI KATSUHISA, TSUDA SHOHEI, ITAKURA TAKAYUKI, SHIOZAWA MOTOHIDE, NAKA TAKESHI
• Format: Patent
• Language: English; Japanese
• Published: 12.03.2015
• Subjects: CINEMATOGRAPHY; ELECTROGRAPHY; ELECTROPHOTOGRAPHY; HOLOGRAPHY; MAGNETOGRAPHY; PHOTOGRAPHY; PHYSICS

PROBLEM TO BE SOLVED: To provide a toner that satisfies the quality of the initial density after being left unused and exhibits excellent durable stability in high-speed printing, and prevents the occurrence of an adverse effect on images (streaks) due to contamination of members with an external additive.SOLUTION: There is provided a toner including toner particles containing a binder resin and colorant, iron oxide particles, and organic-inorganic composite fine particles, where the organic-inorganic composite fine particles include vinyl resin particles and inorganic fine particles embedded in the surface of the vinyl resin particles; the organic-inorganic composite fine particles, on the surface thereof, (i) have at least a part of the inorganic fine particles exposed, (ii) have recesses derived from the inorganic fine particles present, and (iii) have a coverage with the inorganic fine particles of 20% or more and 70% or less; and the iron oxide particles are present on the surface of the toner particles in an amount of 0.1 mass% or more and 5.0 mass% or less based on the mass of the toner particles. 【課題】高温多湿環境における、放置後の初期濃度と高速印字における耐久安定性と、外添剤の部材汚染による画像弊害（スジ）が生じないトナーを提供すること。【解決手段】結着樹脂と着色剤を含有するトナー粒子、酸化鉄粒子、及び有機無機複合微粒子を有するトナーであって、該有機無機複合微粒子は、ビニル系樹脂粒子と、該ビニル系樹脂粒子の表面に埋め込まれている無機微粒子とを有し、該有機無機複合微粒子は、その表面において、ｉ）該無機微粒子の少なくとも一部が露出しており、ｉｉ）該無機微粒子に由来する凸部が存在しており、ｉｉｉ）該無機微粒子による被覆率が２０％以上７０％以下であり、該トナー粒子表面に存在する該酸化鉄粒子が、トナー粒子の質量を基準として、０．１質量％以上５．０質量％以下であることを特徴とする。【選択図】なし