Konica Minolta, Inc.

Konica Minolta Business Technologies, Inc.

Konica Corporation

Konica-minolta Holdings, Inc.

Shiro Hirano

Junya Onishi

Asao Matsushima

Noboru Ueda

Ken Ohmura

Naohiro Hirose

Aya Shirai

Kouji Sugama

Tatsuya Nagase

Tatsuya Fujisaki

Hiroshi Yamazaki

Meizo Shirose

Takaki Kawamura

Yoshiki Nishimori

Takao Yamanouchi

Shingo Fujimoto

Hiroyuki Yamada

Mikio Kouyama

Yoshiyasu Matsumoto

Naoya Tonegawa

Masaaki Kondo

Ami Motohashi

Yusuke Takigaura

Hiroyuki Fukuda

Shinya Obara

Kaori Soeda

Kaori Matsushima

Hiroyuki Yasukawa

Takanari Kayamori

Hirofumi Koga

Kenshi Miyajima

Hidehito Haruki

Junichi Furukawa

Kouji Sekiguchi

Yuya Kubo

Kenji Hayashi

Hiroshi Nagasawa

Satoshi Uchino

Miyuki Murakami

Masaharu Matsubara

Junya Ueda

Natsuki Ito

Atsushi Iioka

Keisuke Asano

Kazuhiko Nakajima

Kazuhisa Horiuchi

Kentarou Mogi

Youhei Ohno

A toner set includes a plurality of toners, wherein the toner set includes a first toner containing a yellow colorant and a second toner containing a cyan colorant, the first toner and the second toner each contain a binder resin containing a vinyl-based resin and a crystalline resin, and a release agent containing a hydrocarbon wax, a content of the vinyl-based resin with respect to a total mass of the binder resin is 50% by mass or more, the first toner contains the crystalline resin having a moiety having a crystal structure and a crystal nucleating agent moiety having a crystal nucleating agent, and the second toner contains the cyan colorant that is a compound represented by general formula (1).

Toner set and image forming method

The toner for developing an electrostatic charge image of the present invention contains a toner base particle comprising a binder resin and at least two kinds of organic pigments, and strontium titanate as an external additive.

Toner for developing an electrostatic charge image and an image forming method

The toner for developing an electrostatic charge image of the present invention contains a toner base particle comprising a binder resin and at least two kinds of organic pigments, and alumina as an external additive. The at least two kinds of organic pigments comprises: a pigment P1 having an absorption maximum wavelength &#x3bb;max (nm) of greater than 400 nm and less than 600 nm when dispersed in methyl ethyl ketone; and a pigment P2 having an absorption maximum wavelength &#x3bb; max (nm) of 600 nm or more and 700 nm or less when dispersed in methyl ethyl ketone.

Provided is an image forming method, including: transferring and fixing a toner onto a recording medium, and forming an image including a plurality of layers, in which an attachment amount of the toner on the recording medium is greater than or equal to 8 g/mand less than or equal to 40 g/m, a toner forming a layer in contact with a fixing member contains at least a first mold release agent containing ester wax and a second mold release agent containing microcrystalline wax, and a special color toner is contained in any layer of the plurality of layers.

Image forming method

Provided is an electrostatic image developing toner including: toner mother particles containing a binder resin and a releasing agent; and an external additive, wherein the binder resin contains a crystalline resin, and the electrostatic image developing toner satisfies the following formulas (1) and (2),tan &#x3b4;&#x3c;tan &#x3b4;&#x2003;&#x2003;Formula (1):0.0005&#x2264;tan &#x3b4;&#x2212;tan &#x3b4;,&#x2003;&#x2003;Formula (2):wherein: tan &#x3b4;is a peak top value of a loss tangent when the loss tangent is measured from 25&#xb0; C. to 100&#xb0; C. at a frequency of 1 Hz and a heating rate of 6&#xb0; C./min; and tan &#x3b4;is a peak top value of a loss tangent when the loss tangent is measured from 25&#xb0; C. to 100&#xb0; C. at a frequency of 1 Hz and a heating rate of 3&#xb0; C./min.

Electrostatic image developing toner

In an image forming method according to the present invention, an image is formed by removing residual charge from the image on an image recording medium. The image forming method includes formation of an image for forming a toner image by fixing a toner on the image recording medium and application of voltage from a voltage applier, the voltage having a polarity reverse to a polarity of a surface potential of the toner image. The toner includes toner base particles and an external additive. The toner base particles include a crystalline polyester resin.

Provided is a means to exhibit excellent low temperature fixability and to improve all of the heat-resistant storage property of a toner, charging uniformity, and transferability under a high temperature and high humidity condition. A toner for developing electrostatic charge image which contains at least a binder resin, in which the binder resin has a core-shell structure having a core portion which contains a hybrid crystalline polyester resin formed by chemical bonds of a crystalline polyester resin unit with an amorphous resin unit other than a polyester resin and an amorphous resin and a shell portion which contains a hybrid amorphous polyester resin formed by chemical bonds of an amorphous polyester resin unit with an amorphous resin unit other than a polyester resin.

Toner for developing electrostatic charge image

An electrostatic charge image developing toner includes a binder resin and a release agent. A ratio of a crystalline polyester resin to the total amount of a amorphous polyester resin and the crystalline polyester resin is within a range exceeding 40% by mass to 60% by mass. A temperature at which a storage modulus before heat left G' before being left to stand at a temperature of X&#xb0; C. becomes 1.0&#xd7;10Pa is within a range exceeding 45&#xb0; C. to 55&#xb0; C. A storage modulus after heat left G&#x2032; at a temperature of X&#x2032;&#xb0; C. at which a value of a ratio of the storage modulus after heat left G&#x2032; at a temperature of X&#xb0; C. after being left to stand at the temperature of X&#xb0; C. for 2 hours to the storage modulus before heat left G&#x2032; at the temperature of X&#xb0; C. becomes the maximum is within a range of 1.0&#xd7;10to 5.0&#xd7;10Pa.

Electrostatic charge image developing toner

A toner for electrostatic charge image development contains a binder resin and a releasing agent. The binder resin contains an amorphous polyester resin as a main component and a vinyl resin, the vinyl resin contains a constitutional unit derived from a specific monomer. The releasing agent has a melting point of from 65 to 90&#xb0; C. and contains an ester wax.

Toner for electrostatic charge image development

An electrostatic latent image developing toner includes toner particles which comprises a binder resin and a releasing agent. A main component of the binder resin is a polyester resin. The binder resin comprises a crystalline polyester resin, an amorphous polyester resin and a hybrid vinyl resin. The hybrid vinyl resin is composed of a vinyl polymer segment and at least one segment selected from a polyester polymer segment, an urethane polymer segment and an urea polymer segment which is chemically bound to the vinyl polymer segment. A main component of the hybrid vinyl resin is the vinyl polymer segment which comprises a structural unit derived from a monomer having a specific structure. A tetrahydrofuran-soluble fraction of the toner has a main peak of a molecular weight distribution measured by gel permeation chromatography within the range of 11000 to 30000.

Electrostatic latent image developing toner

Provided is a toner for developing electrostatic images containing a toner particle. The toner particle contains a binder resin and a release agent. The binder resin contains a vinyl resin component and a crystalline polyester resin component. The vinyl resin component has a structural unit derived from an alkyl (meth)acrylate monomer represented by Formula (1):HC&#x2550;CR&#x2014;COOR&#x2003;&#x2003;Formula (1):In Formula (1), Rrepresents a hydrogen atom or a methyl group, and Rrepresents an alkyl group having 8 to 22 carbon atoms. The crystalline polyester resin component satisfies Formula (2):5&#x2264;|C&#x2212;C|&#x2264;12 &#x2003;&#x2003;Formula (2):In Formula (2), Crepresents the number of carbon atoms of the main chain of a structural unit derived from a polyhydric alcohol and Crepresents the number of carbon atoms of the main chain of a structural unit derived from a polyvalent carboxylic acid.

Toner for developing electrostatic images

An electrostatic charge image developing toner includes a particulate toner matrix containing a binder resin and an external additive. The binder resin includes an amorphous polyester resin, a crystalline resin, and an amorphous vinyl resin. A storage modulus G'(t) measured before the toner is left and storage moduli G&#x2032;(t) and G&#x2032;(t) measured after the toner is left for three hours at temperatures (T-10)&#xb0; C. and (T-20)&#xb0; C., respectively, based on a melting point (T&#xb0; C.) derived from the crystalline resin satisfy the relations represented by G&#x2032;(t)&#x3c;G&#x2032;(t), G&#x2032;(t)&#x3c;G&#x2032;(t), and G&#x2032;(x)/G&#x2032;(x)&#x2264;1.5 in a temperature range A for measurement where the storage modulus G&#x2032;(t) is 1.0&#xd7;10Pa or more. The value t represents any temperature (&#xb0; C.) for measurement in the temperature range A for measurement; and the value x represents the temperature (&#xb0; C.) for measurement having a maximum difference between the storage moduli G&#x2032;(t) and G&#x2032;(t).

An object of the present invention is to provide an electrostatic latent image developing toner containing: a binder resin; and a releasing agent, wherein the binder resin contains a crystalline polyester resin; an endothermic peak top temperature of the electrostatic latent image developing toner is 70&#xb0; C. or more measured with differential scanning calorimetry (DSC) in a heating-up period of the toner; and a heat value &#x394;H(L) is 15% or less with respect to a heat value &#x394;H, wherein the heat value &#x394;H(L) is a heat value in the range of (an exothermic peak top temperature r&#x2212;7&#xb0; C.) or less; and the heat value &#x394;His a heat value of the total exothermic peak measured with DSC in a heating-down period of the toner.

A process for producing a toner of the present invention includes: a first step of heating a dispersion containing an aqueous medium and a binder resin containing a crystalline resin to a temperature higher than or equal to a melting point of the crystalline resin; and a second step of maintaining the dispersion at temperature T (&#xb0; C.) for 30 minutes or longer in a state where a pH of the dispersion is maintained at 5.5 or higher and 9.0 or lower, in which the temperature T satisfies the following expression, Rc&#x2212;25&#x2264;T&#x2264;Rc&#x2212;5, where the Rc represents a recrystallization temperature (&#xb0; C.) of the crystalline resin.

Process for producing a toner

The present invention relates to a toner for electrostatic charge image development, including toner base particles containing a binder resin containing as a main component a vinyl resin having a constitutional unit derived from a monomer having an acid group, and aluminum, wherein a concentration of the aluminum in the toner base particles, as measured by radio inductively coupled plasma emission spectral analysis, is from 900 to 2,200 ppm. According to the present invention, there is provided a means for improving the environmental stability of electrification, and the glossiness and the image density of the image to be formed in a good balance while maintaining sufficient low temperature fixability in a toner for electrostatic charge image development.

Growing community of inventors

Hachioji, Japan

Shiro Hirano