Canon Kabushiki Kaisha

Nobuyoshi Sugahara

Wakashi Iida

Takayuki Itakura

Hironori Minagawa

Hiroyuki Fujikawa

Koh Ishigami

Yoshinobu Baba

Yuto Onozaki

Hirohide Tanikawa

Naoki Okamoto

Yuko Sato

Yuu Nishimura

Nozomu Komatsu

Yojiro Hotta

Yasuhiro Ichikawa

Takaaki Kotaki

Ryuichiro Matsuo

Kazuhiko Hayami

Minoru Yoshifuku

Toru Takahashi

Tetsuya Ida

Takaaki Kohtaki

Hitoshi Sano

Kazunari Ooyama

Takakuni Kobori

Takaaki Kaya

Takaho Shibata

Masaaki Taya

Kazuo Terauchi

Yuzo Tokunaga

Daisuke Tsujimoto

Shin Kitamura

Junko Yoshikawa

Ryo Nakajima

Kazuki Murata

Nobuhiro Yoshida

Atsushi Nakano

Akira Hashimoto

Makoto Kanbayashi

Ryoichi Fujita

Kohji Takenaka

A magnetic carrier comprises a magnetic carrier core and a coating resin layer coating a surface of the magnetic carrier core. The coating resin layer contains resin A and resin B at contents of 1% to 50% by mass and 50% to 90% by mass, respectively, based on resin components of the coating resin layer. The resin A has a first partial structure and a second partial structure, while the resin B has a third partial structure and a fourth partial structure. The mass X of the resin A, the total mass Ma of the first partial structure, and the total mass Mb of the second partial structure satisfy 0.50≤(Ma+Mb)/X≤1.00 and 0.10≤a/b≤30.0, and the SP value of the first partial structure SPa1 and the SP value of the third partial structure SPb3 satisfy 0≤|SPa1−SPb3|≤10.0.

Magnetic carrier and two-component developer

A toner includes toner particles containing a binder resin, a colorant, and inorganic fine particles, in which in a depth profile of an element distribution in a depth region from the outermost surface of a particle to a depth of 500 nm the depth profile being obtained by an element analysis performed by X-ray photoelectron spectroscopy using the toner as a sample, two or more minimum points of a concentration of a carbon element in the depth region exist, a concentration of an inorganic element becomes a maximum value at a depth position corresponding to each of the minimum points, and the inorganic element is an element derived from the inorganic fine particle.

Toner

A magnetic carrier, which is suppressed from causing the loss and wear of a magnetic carrier coating resin even when used for a long time period, and achieves a stable image density and a reduction in toner scattering. In the magnetic carrier, the resin coating layer contains a resin A having a fluorine polymer moiety, the resin coating layer has an average thickness of 50 nm or more, a ratio F(x) (atomic %) of a fluorine atom detected at a position at a depth of x nm from a surface of a magnetic carrier particle by X-ray photoelectron spectroscopy satisfies formula (1) and formula (2), and when x represents an integer of 0 or more and 20 or less, F(x) satisfies formula (3):5.0≤F(0)≤15  (1)F(20)≤5.0  (2)|F(+1)−F()|≤7.5  (3).

Magnetic carrier, two-component developer, and developer for replenishment

A toner comprising a toner particle containing a binder resin containing at least 50 mass % of a polyester resin, wherein the polyester resin contains a polyester resin A having a silicone segment, and in XPS analysis, when X is a ratio of the number of silicon atoms attributable to silicone segments relative to a total number of measured atoms, X1 is a value of the X on the toner particle surface, X2 is a value of the X at a depth of 30 nm from the surface, Z is a ratio of the number of carbon atoms attributable to ester bonds relative to a total number of measured atoms, Z1 is a value of the Z on the toner particle surface and Z2 is a value of the Z at a depth of 30 nm from the toner particle surface, X1, Z1, X2 and Z2 satisfy a specific relationship.

A toner including a toner particle comprising a binder resin and a crystalline polyester, wherein the binder resin contains a polyester having a structure represented by the following formula (1): in formula (1), Rs each independently represent hydrogen, a methyl group, or a phenyl group;A represents a polyester segment;B represents a polyester segment or any functional group selected from the group consisting of &#x2014;ROH, &#x2014;RCOOH, and &#x2014;RNHwherein Rrepresents a single bond or a Calkylene group; andthe average repeat number n is 10 to 80.

A magnetic carrier including a magnetic carrier particle having a magnetic carrier core and a resin coating layer formed on a surface of the magnetic carrier core, wherein the resin coating layer includes a resin component including a resin A and a resin B, the resin A is a copolymer of monomers including (a) a (meth)acrylic acid ester monomer having an alicyclic hydrocarbon group and (b) a specific macromonomer, the resin B is a copolymer of monomers including (c) a styrene-based monomer and (d) a specific (meth)acrylic acid ester monomer, and in a molecular weight distribution of a THF soluble component of the resin component contained in the resin coating layer, a peak derived from the resin B is present in a molecular weight range of from 1000 to 9500.

Magnetic carrier, two-component developer, replenishing developer, and image forming method

A magnetic carrier comprising a magnetic carrier core and a resin coating layer formed on the surface of the magnetic carrier core, wherein wherein, Ris H or CH, and X is a structure represented by the following formula (2):&#x2014;(CH)&#x2014;R&#x2014;(CH)&#x2014;OH&#x2003;&#x2003;(2)wherein, Ris a hydrocarbon group being a cyclic structure having 4 to 8 carbon atoms, and m and n are integers of 0 to 4.

Magnetic carrier, two-component developer, replenishment developer, and image forming method

A magnetic carrier includes a magnetic carrier particle including a magnetic carrier core particle having an amino group on a surface thereof and a resin covering layer disposed on the surface of the magnetic carrier core particle, in which the resin covering layer contains a vinyl-based copolymer and a trialkoxyalkylsilane.

Magnetic carrier, two-component developer, developer for replenishment, and image forming method

A magnetic carrier including a magnetic carrier particle having a magnetic carrier core and a resin coating layer formed on a surface of the magnetic carrier core, wherein the resin coating layer includes a resin component including a resin A and a resin B, the resin A is a copolymer of monomers including (a) a (meth)acrylic acid ester monomer having an alicyclic hydrocarbon group and (b) a specific macromonomer, the resin B is a copolymer of monomers including (c) a styrene-based monomer and (d) a specific (meth)acrylic acid ester monomer, and based on the resin components of the resin coating layer, the amount of the resin A is from 20% by mass to 99% by mass, and the amount of the resin B is from 1% by mass to 80% by mass.

Provided is a magnetic carrier comprising a magnetic carrier particle having a magnetic body-dispersed resin carrier core material and a resin coating layer; the core material includes magnetic particles A and B having number average primary particle diameter of ra and rb (&#x3bc;m), respectively, satisfying ra&#x2265;rb; the particles A each include an oxide of at least one nonferrous metal of Mn, Al, Mg, Ti, and Ni; and an iron oxide; M1 represents total content of the nonferrous metal and F1 represents content of an iron of the magnetic carrier particle measured by XRF diffraction, M1/F1 is 0.010 to 0.100; M2 represents total content of the nonferrous metal and F2 represents content of an iron is F2 of the magnetic carrier particle measured by XPS, M2/F2 is 1.0 to 10.0.

A magnetic carrier having a ferrite-type core material and a resin coat layer present on the surface of the ferrite-type core material, wherein the ferrite-type core material contains a magnetic ferrite-type core material particle and an amino group-bearing primer compound; the resin coat layer contains a coating resin A that is a polymer of monomer containing a (meth)acrylate ester having an alicyclic hydrocarbon group; the content of the amino group-bearing primer compound in the ferrite-type core material and the content of the resin coat layer in the magnetic carrier are within the prescribed range.

Magnetic carrier, two-component developer, replenishing developer, and image-forming method

A magnetic carrier according to the present invention includes a magnetic carrier core and a resin covering layer formed on a surface of the magnetic carrier core, wherein the resin covering layer contains a resin component and an inorganic fine particle, the inorganic fine particle contains an oxide of a typical metal element or a carbonate of a typical metal element, a moisture adsorption rate of the inorganic fine particle when allowed to stand in an environment of a temperature of 30&#xb0; C. and a humidity of 80% for 72 hours is 25.0% by mass or less, an electrical conductivity of the inorganic fine particle is 2.0&#xd7;10&#x3bc;S/m or more and 2.5&#xd7;10&#x3bc;S/m or less, and a degree of crystallinity of the inorganic fine particle is 60% or less.

Magnetic carrier

A magnetic carrier comprising: a magnetic material-dispersed resin carrier core material; and a resin coating layer on the surface of the magnetic material-dispersed resin carrier core material, wherein the magnetic material-dispersed resin carrier core material contains a core material particle containing a magnetic material and a binder resin, and a primer compound having an amino group, the resin coating layer contains a coating resin A, which is a polymer of monomers including at least a (meth)acrylic acid ester having an alicyclic hydrocarbon group, and the content of the primer compound in the magnetic material-dispersed resin carrier core material and the content of the resin coating layer are in specific range.

Magnetic carrier, two-component developer, replenishment developer, and image formation method

Provided is a magnetic carrier, including: a ferrite core particle; and a coating resin, in which: the coating resin has a surface resin layer and a resin composition in the stated order from a surface side thereof; the resin composition contains a resin, and an inorganic particle or carbon black that is subjected to a hydrophilic treatment; the surface resin layer contains a resin, is free of the inorganic particle or the carbon black, and has a thickness of from 0.01 &#x3bc;m or more to 4.00 &#x3bc;m or less; and a moisture percentage change between a moisture percentage when the magnetic carrier is left to stand under an environment of 30&#xb0; C. and 80% RH for 24 hours, and a moisture percentage when the magnetic carrier is left to stand under an environment of 23&#xb0; C. and 5% RH for 24 hours after the standing is 0.030 mass % or less.

The present invention is a magnetic carrier that has a magnetic carrier core and a resin coat layer, wherein the resin coat layer contains a coat resin A and a coat resin B, the coat resin A is a polymer obtained by polymerization of a (meth)acrylate ester monomer that has an alicyclic hydrocarbon group, the coat resin B is a polymer obtained by polymerization of (meth)acrylic monomer and has a polar group and an acid value of 4.0 to 50.0 mg KOH/g, the content of the coat resin A is 10 to 90 mass %, the content of the coat resin B is 10 to 90 mass %, and an acid value of the resin component in the resin coat layer is 1.0 to 10.0 mg KOH/g.

Growing community of inventors

Shizuoka, Japan

Nobuyoshi Sugahara