Patent application number | Description | Published |
20090123856 | DEVELOPER FOR REPLENISHMENT AND IMAGE FORMING METHOD - Provided is a developer for replenishment capable of forming a high-quality image even upon duration. The developer for replenishment includes at least a toner and a magnetic carrier, and in the developer for replenishment, 1 part by mass of the magnetic carrier is blended with 2 to 50 parts by mass of the toner, and the magnetic carrier contains a ferrite core and a resin component, has a true specific gravity of 2.5 to 4.2 g/cm | 05-14-2009 |
20090197190 | TWO-COMPONENT DEVELOPER, REPLENISHING DEVELOPER, AND IMAGE-FORMING METHOD USING THE DEVELOPERS - An object of the present invention is to suppress the adhesion of a carrier to an image bearing member and the generation of a flaw in the surface layer of the image bearing member, and to improve the dot reproducibility of an electrostatic latent image, and soon. The object is achieved by a two-component developer containing a magnetic carrier, which contains resin-containing magnetic particles, in which the packed bulk density ρ1 is 0.80 to 2.40 and ρ1/ρ2 (ρ2 represents true density) is 0.20 to 0.42 of the porous magnetic core particles, and a specific resistance of the porous magnetic core particles, an average breaking strength of the magnetic carrier and a toner surface tension constant in a 45-vol % aqueous solution of methanol measured by a capillary suction time method fall into the specific range, respectively. | 08-06-2009 |
20090233212 | TONER AND TWO-COMPONENT DEVELOPER - Provided is a toner including: toner particles each containing at least a binder resin and a wax; and an external additive, in which surfaces of the toner particles have an average surface roughness (Ra) measured with a scanning probe microscope of 1.0 nm or more and 30.0 nm or less; and the toner has a surface tension index I for a 45-vol % aqueous solution of methanol measured by a capillary suction time method and calculated from the following equation (1) of 5.0×10 | 09-17-2009 |
20090246675 | TWO-COMPONENT DEVELOPER, REPLENISHING DEVELOPER, AND IMAGE-FORMING METHOD USING THE DEVELOPERS - An object of the present invention is to suppress the adhesion of a carrier to an image bearing member and the generation of a flaw in the surface layer of the image bearing member, and to improve the dot reproducibility of an electrostatic latent image, and so on. The object is achieved by a two-component developer containing a magnetic carrier, which contains resin-containing magnetic particles, in which the packed bulk density ρ1 is 0.80 to 2.40 and ρ1/ρ2 (ρ2 represents true density) is 0.20 to 0.42 of the porous magnetic core particles, and a specific resistance of the porous magnetic core particles, an average breaking strength of the magnetic carrier and a toner surface tension constant in a 45-vol % aqueous solution of methanol measured by a capillary suction time method fall into the specific range, respectively. | 10-01-2009 |
20100028796 | MAGNETIC CARRIER AND TWO-COMPONENT DEVELOPER - A magnetic carrier and two-component developer are provided alleviating coarse images, fogging when printing is done after a copier body is left standing for one week in a high temperature and high humidity environment and carrier adhesion after extensive operation in a low image ratio. The magnetic carrier includes magnetic carrier particles including porous magnetic core particles and a resin, wherein in a mercury intrusion method applied to the porous magnetic core particles, a pore diameter in which a differential pore volume in the specific pore diameter range becomes maximum is in a specific range, and when the maximum value of a differential pore volume in the specific pore diameter range is defined as P1 and the maximum value of a differential pore volume in the specific pore diameter range is defined as P2, P1 is in a specific range and the ratio P2/P1 is in a specific range. | 02-04-2010 |
20100119967 | MAGNETIC CARRIER AND TWO-COMPONENT DEVELOPER - A magnetic carrier and a two-component developer are provided which have remedied blank areas, fog after leaving, carrier sticking during running, and image density variations before and after running. The magnetic carrier has magnetic carrier particles having at least porous magnetic core particles and a resin. The magnetic carrier particles satisfying the specific conditions (a), (b) and (c) where, in a reflected electron image of cross sections of the magnetic carrier particles as photographed with a scanning electron microscope, straight lines that divide a cross section of a magnetic carrier particle into 72 at intervals of 5° are drawn from a reference point of the cross section thereof toward the surface of the magnetic carrier particle; the magnetic carrier particles being contained in an amount of 60% by number or more. | 05-13-2010 |
20100119968 | MAGNETIC CARRIER AND TWO COMPONENT DEVELOPER - Provided is a magnetic carrier giving a high quality image free of density variation without the occurrence of fogging or carrier adhesion and having excellent dot reproducibility even during long-term use. The magnetic carrier has magnetic carrier particles produced by filling pores of porous magnetic core particles with a resin. The magnetic carrier contains 80% by number or more of the magnetic carrier particles satisfying the specific conditions (a) and (b) when 18 straight lines passing through a reference point of a cross section of the magnetic carrier particle are drawn at intervals of 10° in a reflected electron image of the cross section of the magnetic carrier particle photographed by a scanning electron microscope. | 05-13-2010 |
20100136473 | MAGNETIC CARRIER AND TWO-COMPONENT DEVELOPER - A magnetic carrier which has magnetic carrier particles each having at least porous magnetic core particles and a resin, in which, in a backscattered electron image of the magnetic carrier particles, photographed with a scanning electron microscope as taken at an accelerating voltage of 2.0 kV, magnetic carrier particles having area proportion S | 06-03-2010 |
20100143833 | MAGNETIC CARRIER, TWO-COMPONENT DEVELOPER AND IMAGE FORMING METHOD - A magnetic carrier is provided which uses a toner having high coloring power and enables development to be performed at low electric field intensity and can form high quality images while keeping gradation characteristics. The magnetic carrier includes magnetic carrier particles including at least porous magnetic core particles and a resin. The electric field intensity just before the break-down of the magnetic carrier is 1,300 V/cm or more and 5,000 V/cm or less. | 06-10-2010 |
20100183971 | MAGNETIC CARRIER, TWO-COMPONENT DEVELOPER AND IMAGE FORMING METHOD - A magnetic carrier having magnetic carrier particles each containing at least a magnetic core particle and a resin; the magnetic carrier having a resistivity of from 1.0×10 | 07-22-2010 |
20110136060 | TONER AND TWO-COMPONENT DEVELOPER - Provided is a toner including: toner particles each containing at least a binder resin and a wax; and an external additive, in which surfaces of the toner particles have an average surface roughness (Ra) measured with a scanning probe microscope of 1.0 nm or more and 30.0 nm or less; and the toner has a surface tension index I for a 45-vol % aqueous solution of methanol measured by a capillary suction time method and calculated from the following equation (1) of 5.0×10 | 06-09-2011 |
20110143277 | TONER, BINARY DEVELOPER, AND IMAGE FORMING METHOD - It is an object of the present invention to provide a toner having the transfer efficiency and the cleanability in combination, exhibiting excellent stress resistance, and ensuring the low-temperature fixing. | 06-16-2011 |
20130171556 | TONER - An object of the present invention is to improve resistance to wraparound during fixing while achieving both low-temperature fixability and resistance to hot offset. A further object is to suppress image density variations and fogging in white background regions during use at high print coverage rate at high temperature and high humidity. A toner containing inorganic fine particles and toner particles containing a binder resin and a wax being provided, the toner being characterized in that the binder resin contains a polyester resin A obtained by condensation polymerization of a polyvalent carboxylic acid and an alcohol component mainly containing an aromatic diol and a polyester resin B obtained by condensation polymerization of a polyvalent carboxylic acid and an alcohol component mainly containing an aliphatic diol, and in that the degree of segregation of the wax in the toner depth direction from the toner surface toward the toner center is controlled. | 07-04-2013 |
20130236830 | TONER, BINARY DEVELOPER, AND IMAGE FORMING METHOD - It is an object of the present invention to provide a toner having the transfer efficiency and the cleanability in combination, exhibiting excellent stress resistance, and ensuring the low-temperature fixing. | 09-12-2013 |
20130244164 | TONER - A toner having toner particles, each of which contains a binder resin, a wax and inorganic fine particles, wherein the inorganic fine particles are fixed at the surface of the toner particles as a result of a surface treatment by hot air, and the degree of uneven distribution of wax in the toner is controlled in a depth direction of the toner, from the toner surface towards a toner central portion. | 09-19-2013 |
20130288173 | TONER - Provided is a toner that has excellent low-temperature fixability, hot offset resistance, high image glossiness and fixing wraparound resistance, as well as high durable stability. The toner includes toner particles that contain a binder resin, a colorant and a wax, and fine inorganic particles on a surface of the toner particles, wherein the binder resin contains a polyester resin A and a styrene resin B, and a content ratio A/B of the polyester resin A and the styrene resin B is 85/15 or more and 98/2 or less based on mass, the styrene resin B has a weight average molecular weight Mw of a tetrahydrofuran soluble component of 2,000 or more and 5,000 or less, and the toner has been subjected to a hot-air surface treatment. | 10-31-2013 |
20130288174 | TONER - A toner is provided that exhibits a satisfactory heat-resistant storability and an excellent low-temperature fixability. The toner has toner particles each of which contains at least a binder resin and a wax, and is characterized in that this toner is obtained by attaching a metal compound to the surface of the toner particle and thereafter performing a surface treatment with a hot air current; the binder resin contains at least a polyester resin; and the metal compound is formed by coordinating or bonding a specific aromatic oxycarboxylic acid to a metal. | 10-31-2013 |
20140113228 | TONER, TWO-COMPONENT DEVELOPER, AND IMAGE FORMING METHOD - A toner has a weight-average particle diameter (D4) of 3.0 μm or more and 8.0 μm or less, wherein the average circularity analyzed by dividing particles of the toner having an equivalent circle diameter of 1.98 μm or more and less than 200.00 μm into 800 in a range of a circularity of 0.200 or more and 1.000 or less is 0.960 or more and 0.985 or less, the proportion of particles A having a circularity of 0.990 or more and 1.000 or less is 25.0% or less on a basis of the number of particles, and the ratio of particles B having an equivalent circle diameter of 0.50 μm or more and less than 1.98 μm to the total particles having an equivalent circle diameter of 0.50 μm or more and less than 200.00 μm is 10.0% or less on a basis of the number of particles. | 04-24-2014 |
20140329176 | TONER AND IMAGE FORMING METHOD - Provided is a toner that allows a transferred image to be stably output regardless of smoothness of a transfer material even under high-temperature and high-humidity environment or under low-temperature and low-humidity environment, that is excellent in cleanability for a transfer member even at the time of high-speed printing, and that causes less member contamination. The toner is a toner including toner particles each containing a binder resin and a wax, and silica fine particles on surfaces of the toner particles, wherein the silica fine particles have a number-average particle diameter of primary particles of 60 nm or more and 300 nm or less, a coverage rate of the surfaces of the toner particles with the silica fine particles is 15% or more and 95% or less, and the toner has a uniaxial collapse stress at a maximum consolidation stress of 10.0 kPa, of 2.5 kPa or more and 3.5 kPa or less. | 11-06-2014 |
20150086917 | TONER AND TWO-COMPONENT DEVELOPER - Provided are a toner and a two-component developer each of which: shows a small fluctuation in charge quantity and a small fluctuation in image density even under a high-temperature and high-humidity environment; and does not cause any member contamination even after endurance and hence can stably output an image. The toner and the two-component developer each have a feature in that positively chargeable strontium titanate fine particles are added to toner particles having fixed thereto negatively chargeable silica fine particles. | 03-26-2015 |