Abstract: A carrier for an electrophotographic developer which has a flowability index F1, represented by formula (1), of 63 to 75 sec/(50·cm3) and a flowability index F2, represented by formula (2), of 30 to 100 Oe·g/cm3:
Type:
Application
Filed:
January 30, 2002
Publication date:
November 28, 2002
Applicant:
POWDERTECH CO., LTD.
Inventors:
Hiromichi Kobayashi, Tsuyoshi Itagoshi, Yasuhiko Kataoka, Yuji Sato
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: A carrier comprised of a core and thereover a polymer, and which polymer contains dispersed therein a mixture of an inorganic polymer, and an organic metallic polymer.
Type:
Grant
Filed:
June 20, 2001
Date of Patent:
July 23, 2002
Assignee:
Xerox Corporation
Inventors:
Stephan V. Drappel, Daniel A. Foucher, Richard P. N. Veregin
Abstract: The present invention provides a carrier for electrophotography, which is capable of charging the toner in the developer very rapidly to a target electrostatic charge and at the same time, is capable of maintaining the target electrostatic charge during printing, so that the chemical fogging related to the slow charging rate can be eliminated and the image density related to the maintenance of the electrostatic charge can be preserved during printing. The charging rate and the charge maintenance of the electrophotographic carrier can be preserved if the carrier composed of magnetic core particles and the resin coat satisfies the following equation (B)>[(−19.4)×(A)+31], wherein (A) represents a carbon content (weight %) of the carrier and (B) represents a ratio of the square root of the number of emitted photoelectrons ((CPS)½) and the photon energy (eV).
Abstract: A carrier for an electrophotographic developer which comprises a carrier core and a resin coat having a conducting agent dispersed therein, the resin coat having an inner layer on the carrier core side and an outer layer coating the inner layer, wherein the inner layer contains 7 to 20% by weight of a conducting agent based on the resinous solid content of the inner layer, the outer layer contains 3 to 15% by weight of a conducting agent based on the resinous solid content of the outer layer, and the conducting agent content of the inner layer is greater than that of the outer layer.
Type:
Grant
Filed:
February 12, 2001
Date of Patent:
May 14, 2002
Assignee:
Powdertech Co., Ltd.
Inventors:
Kanao Kayamoto, Kazunori Takagi, Yuji Sato
Abstract: 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.
Abstract: A micro-powder includes:
(i) a sub-micron sized powder recovered from a synthetic latex emulsion of polymer and surfactant;
(ii) a conductive filler incorporated into the powder; and
(iii) optional charge enhancing additives incorporated into the powder.
The conductive micro-powder finds particular utility as a coating for carrier core particles of toner and developer compositions.
Type:
Grant
Filed:
November 28, 2000
Date of Patent:
March 12, 2002
Assignee:
Xerox Corporation
Inventors:
John Gregory Van Dusen, Thomas R. Hoffend, Vladislav Skorokhod, Richard Phillip Nelson Veregin, Deepak R. Maniar, Mary L. McStravick
Abstract: The present invention provides a toner comprising a binding resin, a colorant, and an ester based wax having an iodine value of not more than 25 and a saponification value of 30 to 300 (for example, at least one selected from the group consisting of meadowfoam oil and derivatives thereof and jojoba oil and derivatives thereof) and a method for producing the same. The present invention also provides a toner comprising silica fine powder containing a component having a polydimethyl siloxane skeleton extracted by an organic solvent at a content of not more than 2.5 wt %, and a method for producing the same. This stabilizes the chargeability and flowability of the toner during long period use, and eliminates the filming on a photoconductive member or a transfer medium. Moreover, toner that provides good fixability, anti-offset properties, waste toner recycle properties, and transfer efficiency can be obtained with good reproducibility.
Type:
Grant
Filed:
January 4, 2001
Date of Patent:
December 4, 2001
Assignee:
Matsushita Electric Industrial Co., Ltd.
Abstract: A toner for electrophotography is disclosed. The toner comprises a binder resin and a colorant and a wax in amount of 0.5 to 8 percent by weight, and adhesion power index of wax particles to toner particles is between 0.7 and 2.2. The toner improves the durability of the developer material and a photoreceptor, minimizes image smear at high temperature and humidity, and exhibits excellent fixation as well as offsetting resistance.
Abstract: There is provided a carrier, for an electrostatographic developer, comprising particles of a hard magnetic ferrite material as the core, the core having a coating of a polymer resin, said resin in turn having a coating of an organic conductive material. The organic conductive material can be a charge control agent and can be present in very small amounts. The developer compositions have no need for preconditioning since they have stable charging characteristics. Further, they exhibit low levels of “dusting”.
Type:
Application
Filed:
June 12, 1998
Publication date:
May 31, 2001
Applicant:
Dinesh Tyagi et al
Inventors:
DINESH TYAGI, DONNA A DIPRIMA, JAMES H ANDERSON