| (19) |
 |
|
(11) |
EP 0 422 892 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
29.05.1991 Bulletin 1991/22 |
| (43) |
Date of publication A2: |
|
17.04.1991 Bulletin 1991/16 |
| (22) |
Date of filing: 09.10.1990 |
|
|
| (84) |
Designated Contracting States: |
|
CH DE ES FR GB LI NL |
| (30) |
Priority: |
09.10.1989 JP 262243/89
02.03.1990 JP 49513/90
|
| (71) |
Applicant: MITA INDUSTRIAL CO., LTD. |
|
Osaka 540 (JP) |
|
| (72) |
Inventors: |
|
- Fukumoto, Takatomo
Osaka (JP)
- Teshima, Takashi
Ibaragi-shi,
Osaka-fu (JP)
- Yamamura, Kazuhiko
Higashi-osaka-shi,
Osaka-fu (JP)
- Taguchi, Kyouya
Imazu,
Nishinomiya-shi,
Hyogo-ken (JP)
- Hazama, Hiroyuki
Noma,
Itami-shi,
Hyogo-ken (JP)
- Higuchi, Takeshi
Yamato-kouriyama-shi,
Nara-ken (JP)
- Honda, Koji
Higashi-osaka-shi,
Osaka-fu (JP)
|
| (74) |
Representative: Cresswell, Thomas Anthony et al |
|
J.A. KEMP & CO.
14 South Square
Gray's Inn
London WC1R 5LX
London WC1R 5LX (GB) |
|
| |
|
| (54) |
Developer and developing process using said developer |
(57) Disclosed is a two-component type developer comprising a toner having an electroconductivity
lower than 3.5 x 10
-10 S/cm, in which an amino group-containing silicone resin is used as the coating resin
for a magnetic carrier. By using the amino group-containing silicone resin as the
coating resin for the magnetic carrier, reduction of the image density caused by a
lowly electroconductive toner is prevented, and even in a color developer for which
a lowly electroconductive toner is used, a high-density image can be formed. According
to a developing process using this developer, the development is possible even under
a high bias voltage condition, and a high-quality image having a high density can
be formed.