Canon Kabushiki Kaisha

Yoshitaka Suzumura

Yusuke Hasegawa

Tomohisa Sano

Shuichi Hiroko

Kozue Uratani

Takashi Matsui

Michihisa Magome

Takuma Ikejiri

Shotaro Nomura

Yuujirou Nagashima

Satoshi Arimura

Atsuhiko Ohmori

Keisuke Tanaka

Hiroyuki Tomono

Osamu Matsushita

Takuya Mizuguchi

Shohei Yamashita

Kazuhiro Yamauchi

Masahiro Watanabe

Taichi Sato

Masahiro Kurachi

Tomohito Taniguchi

Atsushi Uematsu

Noboru Miyagawa

Dai Nozaki

Yoshihiro Ogawa

Takashige Kasuya

Shuntaro Watanabe

Kosuke Fukudome

Tetsuya Kinumatsu

Hiroki Akiyama

Shunsuke Matsushita

Tadashi Dojo

Takehiko Aoyama

Tomohiro Unno

Akira Sakakibara

Issei Imamura

Eriko Yanase

Kenji Ookubo

Hiroki Kagawa

Kouji Nishikawa

Miho Okazaki

Tomoko Sugita

Kozue Aoki

A toner comprising a toner particle, and an external additive on a surface of the toner particle, wherein the external additive comprises an agglomerate of fine silica particles surface-treated with silicone oil; when a number-average particle diameter of the agglomerate of the fine silica particles is defined as Rb, the Rb is 12 to 80 nm; when an integrated value of a D unit is defined as A, which obtained when an integrated value of a Q unit is set to 100 in a CP/MAS measurement in aSi-solid-state NMR of the fine silica particles, the A is 120 to 300, and the agglomerate of the fine silica particles has a coefficient of variation of particle diameters of 1.00 to 3.00, based on a number of the agglomerate of the fine silica particles.

Toner

A toner and a method for producing the toner, wherein; the toner comprising a toner particle comprising a polyester resin, and has a softening point of 150° C. or less; the toner particle has the polyester resin within 100 nm from a surface of the toner particle, and where a value obtained by dividing an amount of counted ions for a structure represented by following formula (A) measured from the surface of the toner particle to a depth of 100 nm by TOF-SIMS by a total amount of counted ions is taken as a standard value, one or more peaks of the standard value are present within a range of 100 nm from the surface of the toner particle, and where A(dmax) denotes a standard value at a maximum peak and A(0) denotes a standard value on the toner particle surface, formula 1.15≤A(dmax)/A(0)≤5.00 is satisfied.

Toner and method for producing toner

The toner contains a toner particle having a core-shell structure including: a core containing a binder resin and a colorant; and a shell, wherein the toner contains a crystalline material, and the shell contains an amorphous thermoplastic resin; and when SP values of the crystalline material and the amorphous thermoplastic resin, which are calculated by the Fedors method, are defined as SPc (J/cm)and SPa (J/cm), respectively, the SPc and the SPa (J/cm) satisfy a particular relationship, and when the toner is observed by SEM after the toner has been subjected to ruthenium staining that treats the toner in an atmosphere of RuOgas having 500 Pa for 15 minutes, a ratio S2 (%) of an area occupied by the crystalline material per area of the toner satisfies a particular relationship.

A toner comprising a toner particle comprising a binder resin and a crystalline resin, wherein the binder resin comprises an amorphous resin, when the toner is measured with a temperature-modulated differential scanning calorimeter, at least one endothermic peak derived from the crystalline resin is present in a temperature range from 55.0&#xb0; C. to 95.0&#xb0; C. in a total heat flow; and a ratio of an endothermic quantity of the endothermic peak in a reversing heat flow to an endothermic quantity of the endothermic peak in the total heat flow is 50.0% or more, a glass transition temperature Tg1st obtained in the reversing heat flow in a first temperature rise and a glass transition temperature Tg2nd obtained in a reversing heat flow in a second temperature rise satisfy Tg1st&#x2212;Tg2nd&#x2265;7.0&#xb0; C.

An electrophotographic apparatus comprising an electrophotographic photosensitive member, a charging device and a developing device, wherein the charging device comprises a conductive member arranged to be capable of contacting the electrophotographic photosensitive member, the conductive layer at the outer surface of the conductive member comprises a matrix and a plurality of domains dispersed in the matrix, at least some of the domains are exposed at the outer surface of the conductive member, the matrix has a volume resistivity R1 of larger than 1.00&#xd7;10&#x3a9;&#xb7;cm, the volume resistivity R1 of the matrix is 1.0&#xd7;10times or more a volume resistivity R2 of the domains, the developing device comprises the toner comprising a toner particle and a silica fine particle, and a coverage ratio of the toner surface with the silica fine particles is from 62.0% by area to 100.0% by area as determined by X-ray photoelectron spectroscopy.

Electrophotographic apparatus, process cartridge and cartridge set

An electrophotographic apparatus comprising an electrophotographic photosensitive member, a charging device and a developing device, wherein the charging device comprises a conductive member arranged to be capable of contacting the electrophotographic photosensitive member, a conductive layer of the conductive member comprises a matrix domain structure, at least a part of the domains Dt is exposed at the conductive member outer surface, the matrix has a volume resistivity R1 of larger than 1.00&#xd7;10&#x3a9;&#xb7;cm, the domains Dt has a volume resistivity of smaller than R1, the developing device comprises the toner, domains Dc formed of the crystalline material exist in a cross section of the toner, distances between adjacent wall surfaces of the domains Dc is from 30 to 1,100 nm, and a weight-average particle diameter D4 of the toner and distances Dms between adjacent wall surfaces between the domains Dt satisfies D4&#x2265;Dms.

Electrophotographic apparatus, process cartridge, and cartridge set

Provided is a toner containing a toner particle including a binder resin, a wax, and a colorant. The softening point of the toner is at least 80&#xb0; C. and not more than 140&#xb0; C. The average circularity of the toner is at least 0.940. The integrated value of stress in the toner at 150&#xb0; C. which is measured by using a tackiness tester is at least 78 g&#xb7;m/sec.

A magnetic toner is provided, which has a magnetic toner particle containing a binder resin, a wax, and a magnetic body, wherein, when Dn is a number-average particle diameter of the toner, CVis coefficient of variation of a brightness variance value of the toner in a particle diameter range of Dn &#x2212;0.500 to +0.500, and CVis coefficient of variation of a brightness variance value of the toner in a particle diameter range of Dn &#x2212;1.500 to &#x2212;0.500, a relationship CV/CV&#x2264;1.00 is satisfied; an average brightness of the toner in the range of Dn &#x2212;0.500 to +0.500 is 30.0 to 60.0; and when, in a cross section of the toner observed using a transmission electron microscope, which is divided with a square grid having a side of 0.8 &#x3bc;m, coefficient of variation CVof an occupied area percentage for the magnetic body is 40.0 to 80.0%.

Magnetic toner and image-forming method

The toner has a toner particle that contains a binder resin, a colorant, a release agent, and a crystalline polyester, wherein the release agent contains an ester wax, and the peak top temperature of the maximum endothermic peak of the ester wax as measured with a differential scanning calorimeter is from 65&#xb0; C. to 85&#xb0; C., the ester wax satisfies specific conditions and the crystalline polyester satisfies specific conditions, the toner contains from 3.0 parts by mass to 20.0 parts by mass of the crystalline polyester per 100 parts by mass of the binder resin, and the mass ratio of the ester wax to crystalline polyester is from 25/75 to 75/25.

Provided is a toner including toner particles, each of which contains a binder resin, a colorant, a releasing agent and a crystalline polyester, wherein in an observation of a cross-section each of the toner particles by transmission electron microscopy, specific toner particles each of which has domains of the crystalline polyester and domains of the releasing agent, are present at a ratio of at least 70% by number of the toner particles in the toner, an arithmetic mean of maximum diameters of the domains of the releasing agent is within prescribed range, and the specific toner particles satisfy prescribed conditions.

A magnetic toner containing a magnetic toner particle having a binder resin and a magnetic body, and inorganic fine particles, wherein when the inorganic fine particles are classified as first inorganic fine particles, second inorganic fine particles, and third inorganic fine particles in accordance with fixing strength thereof to the magnetic toner particle and in the sequence of the weakness of the fixing strength, the content of the first inorganic fine particles, the ratio of the second inorganic fine particles to the first inorganic fine particles, and the coverage ratio X of coverage of the magnetic toner surface by the third inorganic fine particles are in prescribed ranges.

Magnetic toner

The magnetic toner contains a magnetic toner particle having a binder resin and a magnetic body, and inorganic fine particles, wherein the average circularity of the magnetic toner is at least 0.955 and, when classifying the inorganic fine particles, in accordance with the fixing strength thereof to the magnetic toner particle and in the sequence of the weakness of the fixing strength, as first inorganic fine particles, second inorganic fine particles, and third inorganic fine particles, the content of the first inorganic fine particles, the ratio of the second inorganic fine particles to the first inorganic fine particles, and the coverage ratio X are in prescribed ranges.

Provided is a toner including a binder resin, a colorant, a crystalline polyester, and a release agent, wherein a cross-sectional image of the toner is observed using a scanning transmission electron microscope, domains of the crystalline polyester are present in the cross-sectional image of the toner, the domains have a number-average major diameter of at least 50 nm and not more than 300 nm, the number of the domains is at least 8 and not more than 500, and the domains are present at least 60 number % and not more than 100 number % from an outline of the cross-sectional image to 25% of the distance between the outline and the centroid of the cross-sectional image.

A toner comprising toner particles, each of which contains a binder resin and a colorant, wherein an onset temperature Te (&#xb0; C.) of a storage elastic modulus E' obtained in a powder dynamic viscoelastic measurement on the toner is at least 50&#xb0; C. and not more than 70&#xb0; C., and a value at Te (&#xb0; C.) of a storage elastic modulus G&#x2032; obtained in a pellet dynamic viscoelastic measurement on the toner is at least 4.0&#xd7;10Pa and not more than 1.0&#xd7;10Pa.

Growing community of inventors

Mishima, Japan

Yoshitaka Suzumura