US3900414A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrophotographic developer
Assignee: Memorex Corp
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Filing: 1974-01-30
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Granted: 1975-08-19
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Expires: 1994-01-30
Abstract
Abstract A developer mixture for developing electrostatic images made up of relatively large carrier particles having toner particles electrostatically bonded to them, the carrier particles are small metal particles coated with an acrylic resin having a glass transition temperature at least 50*C and below 100*C, with a cellulose acetate butyrate resin containing 10 - 35% by weight acetate, 10 - 40% by weight butyrate and containing less than 60% by weight acetate plus butyrate, or with mixtures of such acrylic resins and such cellulose acetate-butyrate resins.
Inventors
- 👤 Elinor J Tanck
- 👤 Lauren L Hulse
- 👤 Paul P Kelly
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 11:32
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/10; G03G9/113; G03G9/1132; G03G9/1133; G03G9/1135; Y; Y10; Y10S; Y10S430/00; Y10S430/001; Y10S430/105
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
56 words
CARRIER PARTICLES FOR XEROGRAPHIC TONER CONSISTING ESSENTIALLY OF 200-600 MICRON MEAN DIAMETER PARTICLES OF STEEL SHOT THINLY COATED WITH A MIXTURE OF A COPOLYMER OF METHYL METHACRYLATE AND ETHYL ACYLATE HAVING A GLASS TRANSITION TEMPERATURE AT LEAST 50*C. AND BELOW 100*C., AND A CELLULOSE ACETATE BUTYRATE RESIN CONTAINING LESS THAN 60% BY WEIGHT ACETATE PLUS BUTYLATE.
Claim 2
Dependent Claim
56 words
CARRIER PARTICLES FOR XEROGRAPHIC TONER CONSISTING ESSENTIALLY OF 200-600 MICRON MEAN DIAMETER PARTICLES OF STEEL SHOT THINLY COATED WITH A MIXTURE OF A COPOLYMER OF METHYL METHACRYLATE AND ETHYL ACYLATE HAVING A GLASS TRANSITION TEMPERATURE AT LEAST 50*C. AND BELOW 100*C., AND A CELLULOSE ACETATE BUTYRATE RESIN CONTAINING LESS THAN 60% BY WEIGHT ACETATE PLUS BUTYLATE.
References Cited (Backward Citations)
US3533835A
Cited
US3632512A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-18 | 1979-02-17 | 1979-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-18 | 1983-02-17 | 1983-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-18 | 1987-02-17 | 1987-08-19 | $7700.00 | Window Closed / Lapsed |