Patent US3072584A successfully refreshed from Google Patents.
US3072584A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of production of multi-celled extruded foamed polystyrene, polyethylene and polypropylene
Assignee: Dow Chemical Co
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Filing: 1959-12-21
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Granted: 1963-01-08
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Expires: 1979-12-21
Abstract
No abstract record available.
Inventors
- 👤 Karpovich John
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 08:57
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; C08J9/12; B; B29; B29C; B29C44/00; B29C44/34; B29C44/36; B29C44/46; B29C44/50; B29C44/505; B29C2791/00; B29C2791/004; B29C2791/008; B29K; B29K2023/00; B29K2023/04; B29K2023/06; B29K2023/10; B29K2023/12; B29K2025/00; Y; Y10; Y10S; Y10S264/00; Y10S264/13; Y10S264/16; Y10S521/00; Y10S521/915
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
92 words
IN A PROCESS FOR THE PRODUCTION OF SMALL-CELLED EXTRUDED FOAMED POLYSTYRENE THE IMPROVEMENT OF WHICH COMPRISES; SUBJECTING AN EXTRDE OF POLYSTYRENE AND A FOAMING AGENT TO THE ACTION OF CYCLIC SHOCK WAVES PRIOR TO INITIATION OF NORMAL FOAMING, SAID SHOCK WAVES RANGING IN FREQUENCY FROM SUBSONIC TO ULTRASONIC FREQUENCIES AND SAID SHOCK WAVES INITIATING A MULTIPLCITY OF CELL NUCLEATION SITES IN SAID EXTRUDE AND SAID FOAMING AGENT BEING A MEMBER SELECTED FROM THE GROUP CONSISTING OF METHYL CHLORIDE, N-PENTANE, METHYL ETHER, METHYL ETHYL EHTER, ETHYLENE, PROPYLENE, BUTYLENE, NITROGEN, SULFUR DIOXIDE AND SYM-DICHLOROTETRAFLUOROETHANE.
Claim 2
Dependent Claim
92 words
IN A PROCESS FOR THE PRODUCTION OF SMALL-CELLED EXTRUDED FOAMED POLYSTYRENE THE IMPROVEMENT OF WHICH COMPRISES; SUBJECTING AN EXTRDE OF POLYSTYRENE AND A FOAMING AGENT TO THE ACTION OF CYCLIC SHOCK WAVES PRIOR TO INITIATION OF NORMAL FOAMING, SAID SHOCK WAVES RANGING IN FREQUENCY FROM SUBSONIC TO ULTRASONIC FREQUENCIES AND SAID SHOCK WAVES INITIATING A MULTIPLCITY OF CELL NUCLEATION SITES IN SAID EXTRUDE AND SAID FOAMING AGENT BEING A MEMBER SELECTED FROM THE GROUP CONSISTING OF METHYL CHLORIDE, N-PENTANE, METHYL ETHER, METHYL ETHYL EHTER, ETHYLENE, PROPYLENE, BUTYLENE, NITROGEN, SULFUR DIOXIDE AND SYM-DICHLOROTETRAFLUOROETHANE.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1966-01-07 | 1966-07-09 | 1967-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1970-01-07 | 1970-07-09 | 1971-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1974-01-07 | 1974-07-09 | 1975-01-08 | $7700.00 | Window Closed / Lapsed |