The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 07, 1993
Filed:
Oct. 29, 1992
Bijay S Saha, Rochester, NY (US);
Alec N Mutz, Rochester, NY (US);
Eastman Kodak Company, Rochester, NY (US);
Abstract
Carrier particles suitable for magnetic brush development comprising hard magnetic ferrite material having a single phase, W-type hexagonal crystalline structure represented by the formula MFe.sub.16 Me.sub.2 O.sub.27 where M is strontium or barium and Me is a divalent transition metal selected from the group consisting of nickel, cobalt, copper, zinc, manganese, magnesium, iron and mixtures thereof, exhibiting a coercivity of approximately 100 to 300 Oersteds when magnetically saturated and an induced magnetic moment of at least 60 EMU/g when in an applied magnetic field of 1000 Oersteds are disclosed. Also disclosed are electrostatic two-component dry developer compositions comprising charged toner particles mixed with oppositely charged carrier particles comprising the magnetically hard ferrite material described above and a method of developing an electrostatic charge pattern by contacting the charge pattern with a two-component dry developer composition described above. The carrier particles provide high development efficiencies and improved image density.