(19)
(11) EP 0 813 118 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
07.01.1998 Bulletin 1998/02

(43) Date of publication A2:
17.12.1997 Bulletin 1997/51

(21) Application number: 97303745.0

(22) Date of filing: 03.06.1997
(51) International Patent Classification (IPC)6: G03G 9/09, G03G 9/087, G03G 9/097
(84) Designated Contracting States:
AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

(30) Priority: 10.06.1996 JP 147651/96

(71) Applicant: MITA INDUSTRIAL CO. LTD.
Osaka-shi Osaka 540 (JP)

(72) Inventors:
  • Shimizu, Yoshitake
    Chuo-ku, Osaka-shi, Osaka 540 (JP)
  • Nagao, Kazuya
    Chuo-ku, Osaka-shi, Osaka 540 (JP)
  • Funato, Masatomi
    Chuo-ku, Osaka-shi, Osaka 540 (JP)
  • Ishimaru, Seijiro
    Chuo-ku, Osaka-shi, Osaka 540 (JP)
  • Toshimitsu, Masatoshi
    Chuo-ku, Osaka-shi, Osaka 540 (JP)

(74) Representative: W.P. THOMPSON & CO. 
Eastcheap House Central Approach
Letchworth, Hertfordshire SG6 3DS
Letchworth, Hertfordshire SG6 3DS (GB)

   


(54) Toner for two-component type developer


(57) There is provided a toner for a two-component type developer, which comprises (i) toner particles comprising a fixing resin having anionic polar groups, a coloring agent, and a magnetic powder which is used in an amount of 0.1 to 5 parts by weight for 100 parts by weight of the fixing resin, and (ii) an additive comprising silica, alumina and titania, and being adhered on surfaces of the toner particles in a total amount of 0.15 to 2 parts by weight for 100 parts by weight of the toner particles, and contains substantially no charge control agent. The toner exhibits a stable chargeability during a long-term use without generation of a spent toner. As a result, the toner suppresses the image fogging and the toner scattering, and ensures a stable image density and a high image quality for a long term.






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