Abstract: A positively chargeable toner for two-component development comprising a resin binder; a colorant; a releasing agent comprising a wax having a melting point of 50° to 120° C.; and an external additive comprising a positively chargeable silica, the positively chargeable silica having an absolute deviation of an error of 0.1 or less, against an approximate straight line showing an adhesion state of silicon atoms to carbon atoms, and a free ratio of 5% or less, wherein the positively chargeable toner is usable together with a ferrite carrier having a saturation magnetization of from 40 to 100 Am2/kg. This positively chargeable toner is used for development of an electrostatic latent image formed in electrophotography, electrostatic recording method, electrostatic printing method, or the like.
Abstract: A magnetic carrier exhibiting excellent durability against mechanical impact as exerted by vibration and capable of exhibiting a stable charging performance in electrophotography is provided.
Abstract: A carrier for electrophotography and a two component type developer using the carrier. The carrier is composed of magnetic particles of a magnetic ferrite component represented by Formula: (Fe2O3)X(MnO)Y(A)Z. An image forming method is also disclosed which uses the two component type developer.
Type:
Application
Filed:
March 28, 2002
Publication date:
January 9, 2003
Inventors:
Tsuyoshi Takiguchi, Kenji Okado, Tetsuya Ida
Abstract: A method for use in two-components electrostatic image developers is disclosed, in which secure separation of a carrier coating resinous materials from a core magnetic material is achieved without affecting the properties of the core materials through process steps benign to the environment in super- or sub-critical water compositions under the conditions of a temperature of 300° C. or more and a pressure of 20 MPa. The core magnetic material is subsequently recycled for forming carrier. This method may also be useful for processing waste including magnetic materials with silicone resin coating.
Abstract: Methods for development of an electrostatic image are disclosed that utilize developer compositions with hard magnetic carrier compositions which can provide improved development efficiencies and reduced amounts of image carrier pick-up. The methods utilize hard magnetic carrier particles that are modified to have specific levels of resistivity, such as, for example, of from about 1×105 ohm-cm to about 1×1010 ohm-cm, and a carrier charge-to-mass of greater than about 1.0 &mgr;C/g, which carriers can provide greater development speeds without unacceptable levels of image carrier pick-up. In embodiments, the hard magnetic materials are doped, i.e., bulk substituted, with multi-valent metals to adjust resistivity, while in other embodiments, the hard magnetic materials are coated with at least one multi-valent metal oxide.
Type:
Application
Filed:
May 11, 2001
Publication date:
February 28, 2002
Inventors:
Patrick Lambert, Li C. Stelter, William K. Goebel, Peter S. Alexandrovich
Abstract: Disclosed are methods and apparatus for electrographic development which utilize a rotating magnetic core, a toner shell disposed around the rotating magnetic core, and developer compositions disposed on the toner shell which include a hard magnetic material, such as a strontium ferrite. The shell in embodiments has an outer surface with a surface roughness Ra of less than 32 microinches. The methods and apparatus do not require special manufacturing steps to place surface roughness or irregularities on the shell, and, thus, can provide the same or better image quality with relatively less complex manufacturing steps and at reduced cost.
Type:
Application
Filed:
May 11, 2001
Publication date:
December 27, 2001
Inventors:
Eric C. Stelter, Robert D. Fields, Thomas A. Jadwin
Abstract: A ferrite carrier includes manganese oxide, ferric oxide and minor amounts of titanium dioxide and provides an environmentally benign, highly conductive, reprographic carrier powder.