| (19) |
 |
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(11) |
EP 0 438 245 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
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11.09.1991 Bulletin 1991/37 |
| (43) |
Date of publication A2: |
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24.07.1991 Bulletin 1991/30 |
| (22) |
Date of filing: 14.01.1991 |
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| (51) |
International Patent Classification (IPC)5: G03G 9/097 |
|
| (84) |
Designated Contracting States: |
|
DE FR GB |
| (30) |
Priority: |
16.01.1990 JP 4614/90
11.12.1990 JP 409657/90
11.12.1990 JP 409677/90
|
| (71) |
Applicants: |
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- NIPPON ZEON CO., LTD.
Tokyo (JP)
- Oki Electric Industry Co., Ltd.
Tokyo (JP)
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| (72) |
Inventors: |
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- Makuta, Yoshihiro,
2-9-941 Fujisawa Seibu
Kanagawa-ken (JP)
- Ueno, Mitsuo
Yokohama-shi,
Kanagawa-ken (JP)
- Isobe, Minoru,
c/o Oki Electric
Minato-ku,
Tokyo (JP)
- Kikuchi,
c/o Oke Electric,
Industry Co.,Ltd.
Minato-ku,
Tokyo (JP)
- Ito, Katsuyuki,
c/o Oki Electric,
Industry Co.,Lt
Minato-ku,
Tokyo (JP)
|
| (74) |
Representative: Perry, Robert Edward et al |
|
GILL JENNINGS & EVERY
Broadgate House
7 Eldon Street
London EC2M 7LH
London EC2M 7LH (GB) |
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| |
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| (54) |
Non-magnetic one-component developer |
(57) A non-magnetic one-component developer suitable for use in a contact or non-contact
development system. The developer comprises 100 parts by weight of colored fine particles,
which comprises a binder resin and a colorant, and 0.3-10 parts by weight of at least
one fine inorganic powder selected from (i) a fine inorganic powder (I) obtained by
subjecting a fine inorganic powder having an average particle size of 0.1-10 µm and
a heating loss (under drying conditions of 150°C and 1 hour) of at most 1 wt.% to
a hydrophobicity-imparting treatment with a silicone oil and (ii) a fine inorganic
powder (II) obtained by subjecting a fine inorganic powder having an average particle
size of 0.1-10 µm to a two-step hydrophobicity-imparting treatment with at least one
compound selected from silane coupling agents and silazane compounds and then further
with a silicone oil.