发明授权
- 专利标题: Magnetic carrier, two-component developer and image forming method
- 专利标题(中): 磁性载体,双组分显影剂和成像方法
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申请号: US358409申请日: 1999-07-22
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公开(公告)号: US6124067A公开(公告)日: 2000-09-26
- 发明人: Yushi Mikuriya , Kenji Okado , Kazumi Yoshizaki
- 申请人: Yushi Mikuriya , Kenji Okado , Kazumi Yoshizaki
- 申请人地址: JPX Tokyo
- 专利权人: Canon Kabushiki Kaisha
- 当前专利权人: Canon Kabushiki Kaisha
- 当前专利权人地址: JPX Tokyo
- 优先权: JPX10-206036 19980722
- 主分类号: G03G9/08
- IPC分类号: G03G9/08 ; G03G9/097 ; G03G9/107 ; G03G9/113 ; G03G15/08
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.