Patent US3341481A successfully refreshed from Google Patents.
US3341481A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of cellular polyolefins
Assignee: Sekisui America Corp
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Filing: 1964-07-02
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Granted: 1967-09-12
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Expires: 1984-07-02
Abstract
No abstract record available.
Inventors
- 👤 David A Palmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:36
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; C08J9/06; C08J9/0014; C08J9/0028; C08K; C08K5/00; C08K5/36; C08K5/43; Y; Y10; Y10S; Y10S264/00; Y10S264/18; Y10S264/64; Y10S521/00; Y10S521/91; Y10S521/918
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
167 words
A PROCESS FOR PREPARING CELLULAR TGHERMOPLASTIC POLYMERS WHIC COMPRISES (1) HEATING IN A CLOSED MOLD A PREFORMED COMPOSITION COMPRISING (A) A THERMOPLASTIC POLYMER SELECTED FROM THE GROUP CONSISTING OF POLYETHYLENE, POLYPROPYLENE, ETHYLENE-PROPYLENE COPOLYMERS, ETHYLENE-VINYL ACETATE COPOLYMERS, ETHYLENE-ALKYL ACRYLATE COPOLYMERS, POLYSTYRENE, ACRYLONITRILE-BUTADIENE STYRENE TERPOLYMERS, AND POLYVINYL CHLORIDE, (B) AN AZIDO CROSS-LINKING AGENT WHICH DECOMPSES AT A TEMPERATURE WITHIN THE RANGE OF FROM THE SOFTENING TEMPERATURE OF THE COMPOSITION TO ABOUT 275*C., (C) A BLOWING AGENT WHICH YIELDS AT LEAST ONE MOLE OF GAS PER MOLE OF BLOWING AGENT AT A TEMPERATURE WITHIN THE RANGE OF FROM THE SOFTENING TEMPERATURE OF THE COMPOSITION TO ABOUT 275*C., SAID COMPOSITION BEING HEATED TO A TEMPERATURE ABOVE THE SOFTENING POINT OF SAID COMPOSITION AND SUFFICIENT TO RELEASE THE GAS FROM SAID BLOWING AGENT AND TO EFFECT AZIDO MODIFICATION OF SAID POLYMER, AND (2) REDUCING THE PRESSURE ON THE COMPOSITION BY OPENING THE MOLD TO ALLOW FREE EXPANSION AT ATMOSPHERIC PRESSURE OF THE COMPOSITION IN ALL DIRECTIONS TO RETAIN ESSENTIALLY THE PREFORMED SHAPE.
Claim 2
Dependent Claim
167 words
A PROCESS FOR PREPARING CELLULAR TGHERMOPLASTIC POLYMERS WHIC COMPRISES (1) HEATING IN A CLOSED MOLD A PREFORMED COMPOSITION COMPRISING (A) A THERMOPLASTIC POLYMER SELECTED FROM THE GROUP CONSISTING OF POLYETHYLENE, POLYPROPYLENE, ETHYLENE-PROPYLENE COPOLYMERS, ETHYLENE-VINYL ACETATE COPOLYMERS, ETHYLENE-ALKYL ACRYLATE COPOLYMERS, POLYSTYRENE, ACRYLONITRILE-BUTADIENE STYRENE TERPOLYMERS, AND POLYVINYL CHLORIDE, (B) AN AZIDO CROSS-LINKING AGENT WHICH DECOMPSES AT A TEMPERATURE WITHIN THE RANGE OF FROM THE SOFTENING TEMPERATURE OF THE COMPOSITION TO ABOUT 275*C., (C) A BLOWING AGENT WHICH YIELDS AT LEAST ONE MOLE OF GAS PER MOLE OF BLOWING AGENT AT A TEMPERATURE WITHIN THE RANGE OF FROM THE SOFTENING TEMPERATURE OF THE COMPOSITION TO ABOUT 275*C., SAID COMPOSITION BEING HEATED TO A TEMPERATURE ABOVE THE SOFTENING POINT OF SAID COMPOSITION AND SUFFICIENT TO RELEASE THE GAS FROM SAID BLOWING AGENT AND TO EFFECT AZIDO MODIFICATION OF SAID POLYMER, AND (2) REDUCING THE PRESSURE ON THE COMPOSITION BY OPENING THE MOLD TO ALLOW FREE EXPANSION AT ATMOSPHERIC PRESSURE OF THE COMPOSITION IN ALL DIRECTIONS TO RETAIN ESSENTIALLY THE PREFORMED SHAPE.
References Cited (Backward Citations)
US2768407A
Cited
US2283316A
Cited
US2297018A
Cited
US2271498A
Cited
US2678293A
Cited
US2518249A
Cited
US2532243A
Cited
US2830029A
Cited
GB856735A
Cited
US2948664A
Cited
US2927904A
Cited
US3006033A
Cited
US3140266A
Cited
US3058944A
Cited
US3137745A
Cited
US3250731A
Cited
US3250730A
Cited
US6017371A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-09-11 | 1971-03-13 | 1971-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-09-11 | 1975-03-13 | 1975-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-09-11 | 1979-03-13 | 1979-09-12 | $7700.00 | Window Closed / Lapsed |