Claims
- 1. An electrophotographic toner comprising a resin, a pigment and a surface-modified pyrogenically produced aluminum oxide which has been surface modified with a mixture of silane A and silane B corresponding to the formulas: ##STR3## said surface-modified pyrogenically produced aluminum oxide having the following physico-chemical properties:
- ______________________________________Surface (m.sup.2 /g) 50 to 100Stamping density (g/l) 50 to 90Drying loss (%) <5Annealing loss (%) 5.0 to 15C content (%) 0.5 to 12pH 4 to 8.______________________________________
- 2. An electrophotographic toner as set forth in claim 1 in which the ratio of aluminum oxide to silane mixture is in the range 0.5 to 40 parts by weight of silane mixture per 100 parts by weight aluminum oxide.
- 3. An electrophotographic toner as set forth in claim 1 in which there are 1 to 99 parts by weight of silane A to 1 to 99 parts by weight of silane B.
- 4. An electrophotographic toner as set forth in claim 3 in which there are 50.+-.20 parts by weight of silane A and 50.+-.20 parts by weight of silane B.
Priority Claims (1)
Number |
Date |
Country |
Kind |
42 02 694.6 |
Jan 1992 |
DEX |
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Parent Case Info
This is a division of application Ser. No. 08/141,083, filed Oct. 27, 1993 now U.S. Pat. No. 5,419,928 which is a Divisional application of Ser. No. 08/012,163 filed Jan. 28, 1993 now U.S. Pat. No. 5,384,194.
US Referenced Citations (6)
Foreign Referenced Citations (5)
Number |
Date |
Country |
3516937 |
Nov 1985 |
DEX |
58-185405 |
Oct 1983 |
JPX |
59-52255 |
Aug 1984 |
JPX |
2-108069 |
Apr 1990 |
JPX |
5-119517 |
May 1993 |
JPX |
Divisions (2)
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Number |
Date |
Country |
Parent |
141083 |
Oct 1993 |
|
Parent |
12163 |
Jan 1993 |
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