US4925762A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Carrier for reprography and production of this carrier
Assignee: BASF SE
•
Filing: 1988-08-17
•
Granted: 1990-05-15
•
Expires: 2008-08-17
Abstract
Abstract Carriers for a two-component dry developer are based on a ferrite or iron-containing core which carries a metal oxide layer consisting of reaction products deposited in the gas phase. The carriers according to the invention have abrasion-resistant metal oxide layers which permit electrostatic charging in both directions. By adjusting the thickness of the metal oxide layer, the electrical conductivity can be altered.
Inventors
- 👤 Werner Ostertag
- 👤 Erwin Czech
- 👤 Franz-Ulrich Schmitt
- 👤 Detlef Schulze-Hagenest
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 02:45
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/10; G03G9/107; G03G9/1075; G03G9/113; G03G9/1139; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
58 words
A carrier for a two-component dry developer, wherein the said carrier has, on particles of a ferrite core or a metallic iron core, a homogeneous metal oxide layer formed by a gas phase reaction of a volatile metal compound with oxygen or water or with oxygen and water in the presence of agitated core particles at elevated temperatures.
Claim 2
Dependent Claim
58 words
A carrier for a two-component dry developer, wherein the said carrier has, on particles of a ferrite core or a metallic iron core, a homogeneous metal oxide layer formed by a gas phase reaction of a volatile metal compound with oxygen or water or with oxygen and water in the presence of agitated core particles at elevated temperatures.
Claim 3
Dependent Claim
22 words
A carrier as claimed in claim 1, wherein the metal oxide layer consists of iron oxide produced by oxidation of iron carbonyl.
Claim 4
Dependent Claim
22 words
A carrier as claimed in claim 1, wherein the metal oxide layer consists of iron oxide produced by oxidation of iron pentacarbonyl.
Claim 5
Dependent Claim
27 words
A carrier as claimed in claim 1, wherein the metal oxide layer consists of titanium dioxide produced by hydrolytic decomposition of titanium tetrachloride in the gas phase.
Claim 6
Dependent Claim
22 words
A carrier as claimed in claim 1, which has a specific electrical conductivity of from 10 to 10 -11 S.cm -1 .
Claim 7
Dependent Claim
22 words
A carrier as claimed in claim 2, which has a specific electrical conductivity of from 10 to 10 -11 S.cm -1 .
Claim 8
Dependent Claim
22 words
A carrier as claimed in claim 3, which has a specific electrical conductivity of from 10 to 10 -11 S.cm -1 .
Claim 9
Dependent Claim
22 words
A carrier as claimed in claim 4, which has a specific electrical conductivity of from 10 to 10 -11 S.cm -1 .
Claim 10
Dependent Claim
53 words
A process for the preparation of a carrier for a two-component dry developer, which carrier has a metal oxide coating on a ferrite or metallic iron core, wherein a volatile metal compound is reacted with oxygen or water or with oxygen and water in the presence of agitated core particles at elevated temperatures.
Claim 11
Dependent Claim
53 words
A process for the preparation of a carrier for a two-component dry developer, which carrier has a metal oxide coating on a ferrite or metallic iron core, wherein a volatile metal compound is reacted with oxygen or water or with oxygen and water in the presence of agitated core particles at elevated temperatures.
Claim 12
Dependent Claim
30 words
A process as claimed in claim 9, wherein the volatile metal compound and its reactants, oxygen or water or oxygen and water, are introduced with the aid of carrier gases.
Claim 13
Dependent Claim
17 words
A process as claimed in claim 9, wherein the volatile metal compound used is an iron carbonyl.
Claim 14
Dependent Claim
12 words
A process as claimed in claim 11, wherein iron pentacarbonyl is used.
Claim 15
Dependent Claim
16 words
A process as claimed in claim 9, wherein the volatile metal compound used in titanium tetrachloride.
Claim 16
Dependent Claim
16 words
A process as claimed in claim 10, wherein the volatile metal compound used is titanium tetrachloride.
Claim 17
Dependent Claim
17 words
A process as claimed in claim 9, wherein the core particles are fluidized in a fluidized bed.
Claim 18
Dependent Claim
17 words
A process as claimed in claim 12, wherein the core particles are fluidized in a fluidized bed.
Claim 19
Dependent Claim
17 words
A process as claimed in claim 13, wherein the core particles are fluidized in a fluidized bed.
Claim 20
Dependent Claim
17 words
A process as claimed in claim 9, wherein the core particles are agitated in a fixed bed.
Claim 21
Dependent Claim
33 words
A process as claimed in claim 12, wherein the concentration of the volatile metal compound does not exceed 5% by volume, based on the total amount of other gases introduced per unit time.
Claim 22
Dependent Claim
33 words
A process as claimed in claim 13, wherein the concentration of the volatile metal compound does not exceed 5% by volume, based on the total amount of other gases introduced per unit time.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-05-14 | 1993-11-13 | 1994-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-14 | 1997-11-13 | 1998-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-14 | 2001-11-13 | 2002-05-15 | $7700.00 | Window Closed / Lapsed |