Canon Kabushiki Kaisha

Syuhei Moribe

Takashige Kasuya

Katsuhisa Yamazaki

Masami Fujimoto

Daisuke Yoshiba

Yoshihiro Ogawa

Hiroshi Yusa

Shuichi Hiroko

Kenji Okado

Takakuni Kobori

Junko Nishiyama

Kouji Nishikawa

Junko Hirata

Tooru Takahashi

Hirata Junko

An image-forming method includes forming an electrostatic image on an electrostatic image bearing member which has been charged; developing the electrostatic image to form a toner image; transferring the toner image on the electrostatic image bearing member with or without mediating an intermediate transferring member onto a transfer material; and fixing the toner image on the transfer material. The electrostatic image bearing member is a photosensitive member obtained by sequentially laminating a photoconductive layer and a surface layer formed of hydrogenated amorphous silicon carbide, and a sum of an atomic density of silicon atoms and an atomic density of carbon atoms in the surface layer of the photosensitive member is 6.60&#xd7;10atoms/cmor more. The toner has a binder resin and magnetic iron oxide particles, and the magnetic iron oxide particles contain Fe(2+) at a content of 20.0 mass % or more and 25.0 mass % or less.

Image-forming method and image-forming apparatus

Provide is a toner including toner particles each containing at least a binder resin and a colorant, and an inorganic fine powder, in which the inorganic fine powder has a ratio (A/B) of a total pore volume A measured in a pore diameter range of from 1.9 nm or more and to 8.0 nm or less to a total pore volume B measured in a pore diameter range of from 1.9 nm or more and to 300.0 nm or less of from 0.20 or more and to 1.00 or less, and the total pore volume A is from 1.00&#xd7;10cm/g or more and to 1.00 cm/g or less.

Toner

The present invention provides a toner which is excellent in low-temperature fixability and transparency and has high gloss, and which is excellent in offset resistance, storage stability, and development stability. The toner is characterized in that: a square radius of inertia Rt at a peak top of a main peak in GPC-RALLS-viscometer analysis of tetrahydrofuran (THF) soluble matter when the toner is dissolved in a THF solvent at 25&#xb0; C. for 24 hours is 1.0 nm to 3.8 nm; and the square radius of inertia Rt and a square radius of inertia Rp at a peak top of a main peak in GPC-RALLS-viscometer analysis of THF soluble matter when linear polystyrene, having an absolute peak molecular weight value at the same value as a main peak value of the toner, is dissolved in a THF solvent at 25&#xb0; C. for 24 hours satisfy the relationship of Rt/Rp&#x3c;0.85.

To provide a developer and an image forming method with each of which a high-resolution, high-definition image can be stably obtained over a long time period irrespective of an environment. The present invention provides a developer including at least: toner particles each containing at least a binder resin; and a composite inorganic fine powder, the developer being characterized in that: the composite inorganic fine powder has a peak at a Bragg angle (2&#x3b8;&#xb1;0.20 deg) of each of 32.20 deg, 25.80 deg, and 27.50 deg in a CuK&#x3b1; characteristic X-ray diffraction pattern; and the half width of the X-ray diffraction peak at a Bragg angle (2&#x3b8;&#xb1;0.20 deg) of 32.20 deg is 0.20 to 0.30 deg.

Developer and image forming method

The present invention aims to provide a toner having excellent developability and excellent low-temperature fixability without causing adhesion of ejected sheets even in a high-speed oilless fixing system and capable of preventing a frameless printing from causing a twisted offseting phenomenon. Specifically, provided is a toner having toner particles including at least a binder resin and a colorant, in which, when the toner is dissolved in a tetrahydrofuran (THF) solvent at 25&#xb0; C. for 24 hours, the ratio of a THF-soluble matter having an intrinsic viscosity of 5.0&#xd7;10dl/g or less with respect to the total amount of the THF-soluble matter in a GPC-RALLS-viscometer analysis is 15.0 mass % to 60.0 mass %, and the ratio of a THF-soluble matter having an intrinsic viscosity of 1.5&#xd7;10dl/g or more with respect to the total amount of the THF-soluble matter in a GPC-RALLS-viscometer analysis is 20.0 mass % to 40.0 mass %.

Toner with specified amounts of the THF-soluble matter having certain intrinsic viscosity

A toner is provided which can stably provide a favorable density stability, line reproducibility and dot reproducibility even in high-speed copying machines, printers and the like which form high resolution latent images over a long period regardless of environmental conditions, and can provide the image quality adaptable to embedded pattern printing, QR code printing and the like. The present invention is characterized in that the toner which includes toner particles including at least a binder resin and a colorant, and a fine silica powder, has a volume median diameter (D) of not less than 0.70 &#x3bc;m and not more than 3.00 &#x3bc;m, and a total pore volume of not more than 0.200 cm/g, measured in the range of the pore diameter from not less than 1.7 nm and not more than 300.0 nm.

Toner used in electrophotography having toner particles and silica powder

Provided is a magnetic toner comprising magnetic toner particles each comprising at least a binder resin and a magnetic iron oxide, the magnetic toner being excellent in developability and environmental stability, and being capable of reducing a toner consumption. A saturation magnetization &#x3c3;s and a remanent magnetization &#x3c3;r of the magnetic toner in a measured magnetic field of 795.8 kA/m are arranged in the range of 5 to 60 Am/kg and in the range of 0.1 to 10.0 Am/kg, respectively, and the binder resin having a polyester component polymerized by using a Ti chelate compound as a catalyst is used.

Magnetic toner

A toner of the present invention comprises at least a binder resin comprising as a main component a polyester resin, a wax, and a colorant, in which in case of measuring a wettability of the toner with respect to a mixed solvent of methanol and water in terms of an optical transimittance at an optical wavelength of 780 nm, a methanol concentration of the mixed solvent is in a range of 45 to 65% by volume when an optical transmittance is 80% and 10%, respectively; a melt index (MI) is of 0.1 to 10 g/10 min at a temperature of 125&#xb0; C. and a load of 5 kg; the toner comparises a resin component insoluble to tetrahydrofuran (THF insoluble component) in an amount of 5 to 40% by mass based on a mass of the binder resin; and the toner comprises a THF soluble component having a main peak in a molecular weight region of 3,000 to 20,000, and has a proportion of a component having a molecular weight of 10,000 or less in the THF soluble component is 50% by mass or more, according to a chromatogram of the THF soluble component measured by gel permeation chromatography. According to the toner of the present invention, it is possible to control lowering of an image density after leaving under a high temperature and high humidity environment, and a decline in the image density due to a charge-rise phenomenon upon low rate printing. Further, the toner has excellent fixing property and high temperature offset characteristic, and occurring of the end-offset is controlled.

Growing community of inventors

Numazu, Japan

Syuhei Moribe