Fuji Xerox Co., Ltd.

Fujifilm Business Innovation Corp.

Soutaro Kakehi

Sakon Takahashi

Moegi Iguchi

Yutaka Saito

Yuka Yamagishi

Mona Tasaki

Tsuyoshi Murakami

Satoshi Kamiwaki

Akihiro Iizuka

Tsutomu Furuta

Yasuko Torii

An electrostatic image developer includes a toner containing toner particles, a carrier, and an external additive containing titanium dioxide particles of two types having different refractive indexes, fatty acid metal salt particles, and an abrasive.

Electrostatic image developer, process cartridge, image forming apparatus, and image forming method

An electrostatic-image developing toner includes toner particles, inorganic particles externally added to the toner particles, and a low-molecular-weight siloxane having a molecular weight of 200 or more and 600 or less. The low-molecular-weight siloxane includes only a siloxane bond and an alkyl group. The total content of the low-molecular-weight siloxane in the electrostatic-image developing toner is, by mass, 0.01 ppm or more and 5 ppm or less.

Electrostatic-image developing toner, electrostatic-image developer, toner cartridge, process cartridge, image forming apparatus, and image forming method

Provided is an electrostatic charge image developing toner including: toner particles; and strontium titanate particles A and strontium titanate particles B having different average primary particle diameters from each other. The strontium titanate particles B have an average primary particle diameter Db of 10 nm to 100 nm. An average primary particle diameter Da of the strontium titanate particles A and the average primary particle diameter Db of the strontium titanate particles B satisfy a relationship of 10&#x2264;Da/Db&#x2264;100.

Electrostatic charge image developing toner and electrostatic charge image developer

An electrostatic charge image developing toner includes: a toner particle having average circularity of 0.91 or more and 0.98 or less, a silica particle externally added to the toner particle, and a strontium titanate particle that is externally added to the toner particle, that has an average primary particle diameter of 10 nm or more and 100 nm or less, that has average primary particle circularity of 0.82 or more and 0.94 or less, and circularity that becomes 84% of accumulation of the primary particle of more than 0.92.

Electrostatic charge image developing toner, electrostatic charge image developer, and toner cartridge

An electrostatic charge image developing toner includes: a toner particle that contains a releasing agent, that has an exposed portion in which the releasing agent is exposed on a surface, and in which a proportion of the exposed portion occupying a surface, which is obtained by X-ray photoelectron spectroscopic analysis is 1 atom % or more and 20 atom % or less; and a strontium titanate particle that is externally added to the toner particle, that is doped with a metal element other than titanium and strontium, and in which an average primary particle diameter is 10 nm or more and 100 nm or less.

An electrostatic charge image developing toner includes a toner particle, a lubricant particle that is externally added to the toner particle, and a strontium titanate particle that is externally added to the toner particle, that has an average primary particle diameter of 10 nm or more and 100 nm or less, that has an average primary particle circularity of 0.82 or more and 0.94 or less, and that has a primary particle circularity that becomes 84% of accumulation of more than 0.92.

An electrostatic charge image developing toner includes: a toner particle and a strontium titanate particle that is externally added to the toner particle, in which an average primary particle diameter of the strontium titanate particle that is present on a surface of the toner particle is 30 nm or more and 100 nm or less, and average primary particle circularity is 0.82 or more and 0.94 or less, and in which circularity that becomes 84% of accumulation of the primary particle is greater than 0.92.

An electrostatic charge image developing toner includes a toner particle; a strontium titanate particle that is externally added to the toner particle and that is doped with a metal element having an electronegativity of 1.3 or less; and a silica particle that is externally added to the toner particle, in which in a case where a detected peak intensity of a metal element having an electronegativity of 1.3 or less is Me-R, a detected peak intensity of strontium is Sr&#x2014;R, a detected peak intensity of silicon is Si&#x2014;R, and an element proportion of strontium is Sr&#x2014;P, Conditions (1) to (3) are satisfied,0.08 kcps&#x2264;Me-R&#x2264;10 kcps,&#x2003;&#x2003;(1)0.1%&#x2264;Sr&#x2014;P&#x2264;3.0%, and&#x2003;&#x2003;(2)0.15&#x2264;Sr&#x2014;R/Si&#x2014;R&#x2264;12.&#x2003;&#x2003;(3)

A carrier set for electrostatic charge image developer, includes: a first carrier that satisfies Expression (1); 160 mJ&#x2266;x&#x2266;200 mJ, and a second carrier that satisfies Expression (2); 210 mJ&#x2266;y&#x2266;250 mJ, wherein x is a total energy amount, which is measured by a powder rheometer, of a developer which is prepared by mixing the first carrier and a toner for measurement such that a weight ratio of the toner is 8% by weight based on the developer, and y is a total energy amount, which is measured by the powder rheometer, of a developer which is prepared by mixing the second carrier and the toner for measurement such that a weight ratio of the toner is 8% by weight based on the developer.

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Kanagawa, Japan

Soutaro Kakehi