| 摘要 |
Disclosed are two-phase glass composite carrier particles which comprise a composite of a magnetically hard ferrite material having a single phase hexagonal crystalline structure of the formula MO.6Fe2O3 where M is barium, strontium or lead exhibiting a coercivity of at least 300 Oersteds when magnetically saturated and an induced magnetic moment of at least 20 EMU/gm when in an applied field of 1000 Oersteds which is dispersed in a glass matrix comprised of from about 10 to 20 molar percent CuO, from about 10 to 40 molar percent BaO and from about 10 to 40 molar percent B2O3; or a glass matrix comprised of from about 10 to 20 molar percent of V2O5, from about 10 to 40 molar percent BaO and from about 10 to 40 molar percent B2O3. Also disclosed is an electrostatic two-phase dry developer composition comprising charged toner particles mixed with oppositely charged carrier particles as described above. A method of developing an electrostatic image by contacting the image with the two-phase dry developer composition also is disclosed. The developer compositions of the invention exhibit reduced toner throw-off and other disclosed advantages.
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