US3676419A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing fine polyethylene powder
Assignee: Japan Atomic Energy Agency
•
Filing: 1969-02-28
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Granted: 1972-07-11
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Expires: 1989-02-28
Abstract
Abstract It has been found that a fine powder of polyethylene, the average particle size of which is not more than 100 microns in diameter, is obtained by polymerizing ethylene at a temperature lower than the melting point of the produced polyethylene, by means of irradiation of an ionizing radiation or free radical initiator, dispersing the thus produced powder polyethylene in a water-miscible liquid dispersing medium which wets the polyethylene but does not substantially dissolve it, and the surface tension of which is not more than 32.5 dyne/cm, to dissociate the agglomerated polyethylene powder particles washing the dissociated polyethylene powder particles with water, and drying the particles.
Inventors
- 👤 Masaaki Takehisa
- 👤 Shiro Senrui
- 👤 Hayato Nakajima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 08:58
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/12; C08J3/16; C08J2323/00; C08J2323/02; C08J2323/04; C08J2323/06; Y; Y10; Y10S; Y10S526/00; Y10S526/909
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
14 words
The process of claim 1 wherein the organic compound is acetone, or ethyl ether.
Claim 2
Dependent Claim
38 words
The process of claim 1 wherein the polymerization is carried out in a liquid or gas-liquid mixed phase in the presence of the dispersing medium as the polymerization medium, and said dispersion takes place as the polymerization proceeds.
References Cited (Backward Citations)
US3553187A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-11 | 1976-01-10 | 1976-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-11 | 1980-01-10 | 1980-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-11 | 1984-01-10 | 1984-07-11 | $7700.00 | Window Closed / Lapsed |