摘要:
An image forming method is disclosed in which a contact charging means is brought into contact with a latent image bearing member to electrostatically charge the latent image bearing member on which electrostatic latent images are formed and developed with a one component type or two component type developer to form toner images, using a developing assembly provided with a developing container and a developer carrying member. The one component developer is comprised of toner particles. The two component type developer is comprised of toner particles and a magnetic carrier. The toner particles of the one component type and two component type developers contains fine particles as an external additive.The latent image bearing member has a surface layer having a volume resistivity A of from 10.sup.8 to 10.sup.15 .OMEGA..multidot.cm; the contact charging means comprises an assembly for electrostatically charging the latent image bearing member by applying a voltage to a charging member having a volume resistivity B of from 10.sup.4 to 10.sup.9 .OMEGA..multidot.cm; the toner has, as an external additive, fine particles having a volume resistivity C of from 10.sup.7 to 10.sup.11 .OMEGA..multidot.cm; the magnetic carrier has a volume resistivity D1 of from 10.sup.9 to 10.sup.15 .OMEGA..multidot.cm; and the developer carrying member has a surface layer having a volume resistivity D2 of from 10.sup.9 to 10.sup.15 .OMEGA..multidot.cm. The resistivities A, B, C, D1 and D2 stasisfy the following conditions: B
摘要:
A toner is disclosed which has toner particles and an external additive. The toner has (a) in circularity distribution of particles measured with a flow type particle image analyzer, an average circularity of from 0.920 to 0.995, containing particles with a circularity of less than 0.950 in an amount of from 2% by number to 40% by number; and (b) a weight-average particle diameter of from 2.0 .mu.m to 9.0 .mu.m as measured by Coulter method. The external additive has, on the toner particles, at least (i) an inorganic fine powder (A) present in the state of primary particles or secondary particles and having an average particle length of from 10 m.mu.m to 400 m.mu.m and a shape factor SF-1 of from 100 to 130 and (ii) a non-spherical inorganic fine powder (B) formed by coalescence of a plurality of particles and having a shape factor SF-1 of greater than 150. Also, a two-component developer and an image forming method, using the toner, are disclosed.
摘要:
A two-component type developer has a negatively chargeable toner having toner particles and an external additive and a magnetic-fine-particle-dispersed resin carrier. The magnetic-fine-particle-dispersed resin carrier has composite particles containing at least inorganic compound particles and a binder resin. The inorganic compound particles have been surface-treated with a lipophilic-treating agent having at least one type of functional group (A) selected from the group consisting of an epoxy group, an amino group, a mercapto group, an organic acid group, an ester group, a ketone group, an alkyl halide group and an aldehyde group, or a mixture of the agent. The composite particles have been surface-coated with at least one type of coupling agent having at least one type of functional group (B) different from the functional group (A) the lipophilic-treating agent. The functional group (B) the coupling agent has being a functional group or groups selected from the group consisting of an epoxy group, an amino group and a mercapto group. The negatively chargeable toner has a weight-average particle diameter of from 3 &mgr;m to 9 &mgr;m.
摘要:
In the image forming machine of the invention, a two-component type developer has a spherical magnetic powder dispersion type carrier, which has a weight average particle diameter of from 15 to 60 .mu.m. The external additive is present in the form of particles on the toner particle, and comprises inorganic oxide fine particles A having a shape factor SF-1 of from 100 to 130, and non-spherical inorganic oxide fine particles B, having a shape factor SF-1 larger than 150 and particles B having been obtained by combining a plurality of component particles.
摘要:
An electrophotographic black toner containing carbon black in a good dispersion state as well as a combined charge control agent system including a specific azo iron metal compound of formula (1) shown below and an oxycarboxylic acid metal compound is produced through polymerization in an aqueous system. The combined charge control agent system shows an effects of synergistically improving the chargeability of spherical polymerized toner particles. The azo iron metal compound improves the dispersion of the carbon black in the toner particles. ##STR1## wherein the denotations of R.sub.1 -R.sub.6, n, n' and A.sup..sym. are omitted.
摘要:
In an image forming apparatus having at least one single electrostatic latent image bearing member and a plurality of image forming units each having a replenishing developer cartridge and a developing assembly, at least one of the image forming units is a special-color image forming unit having a special-color replenishing developer cartridge containing a special-color replenishing developer, and at least one of the other image forming unit is a non-special-color image forming unit having a non-special-color replenishing developer cartridge containing a non-special-color replenishing developer. The special-color replenishing developer cartridge has a volume larger than the volume of the non-special-color replenishing developer cartridge, and the special-color replenishing developer contains a toner and a carrier.
摘要:
In a full-color image-forming method having at least a charging step, a latent-image-forming step, a developing step of developing an electrostatic latent image by the use of a developer; a transfer step, and a fixing step, the developer comprises a plurality of color developers and a black developer. The color developers are each a two-component developer for full-color image formation which has i) a color toner having color toner particles containing at least a binder resin, a colorant and a wax and ii) a carrier for the color developer. The black developer is a two-component developer for full-color image formation which has i) a black toner having black toner particles containing at least a binder resin, carbon black and a wax and ii) a carrier for the black developer. The carrier for the black developer has a larger absolute value of charge quantity when the same toner is used, than the respective carriers for the color developers.
摘要:
In an image forming apparatus having a powder transport mechanism including a powder container and a powder transport means which rotates relative to the powder container, the powder transport means has the rotation center substantially on the axis of the powder container, and the space between the inner wall surface of the powder container and the powder transport means is sealed with magnetic particles held by a magnetic-filed generation means. The magnetic particles have a specific saturation magnetization σs and a specific value of A×σA where the residual magnetic flux density of the magnetic-field generation means is represented by A in a specific range and the magnetization intencity of the magnetic particles in a magnetic field with the residual magnetic flux density A is represented by σA.
摘要:
A carrier for use in electrophotography has carrier cores comprising a binder resin and metal compound particles dispersed therein, and a coating resin for coating the surfaces of the carrier cores. Water adsorption TH2O-H (% by weight) after the carrier has been left in an environment of 30° C./80%RH, water adsorption TH2O-L (% by weight) after the carrier has been left in an environment of 23° C./5%RH, and particle surface area Sm (cm2/g) of the carrier satisfy the following relationship: 6.00×10−6≦TH2O-H/(100×Sm)≦1.50×10−5, and 1.00×10−6≦TH2O-L/(100×Sm)≦5.50×10−6.
摘要:
A magnetic carrier constituting a two-component developer for use in an electrophotographic image forming method is formed of a carrier core comprising a first resin and magnetic fine particles dispersed in the first resin, and a second resin surface-coating the carrier core. (a) The magnetic carrier has a true specific gravity of 2.5-4.5, a magnetization .sigma..sub.1000 as measured in a magnetic field of 1000.times.(10.sup.3 /4.pi.).multidot.A/m (1000 oersted) of 15-60 Am.sup.2 /kg (emu/g), a residual magnetization .sigma..sub.r of 0.1-20 Am.sup.2 /kg (emu/g) and a resistivity of 5.times.10.sup.11 -5.times.10.sup.15 ohm.cm. (b) The first resin has a polymer chain including a methylene unit (--CH.sub.2 --). (c) The second resin has at least a fluoro-alkyl unit, a methylene unit (--CH.sub.2 --) and an ester unit. (d) The carrier core is surface-coated with (i) a mixture of the second resin and a coupling agent having at least an amino group and a methylene unit, or (ii) a coupling agent having at least an amino group and a methylene unit, and then with the second resin.