US3983080A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Extrusion foaming of normally crystalline vinylidene chloride polymers
Assignee: Dow Chemical Co
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Filing: 1974-09-20
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Granted: 1976-09-28
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Expires: 1994-09-20
Abstract
Abstract This invention is directed to a process for forming stable, low density, fine celled extruded foam from normally crystalline vinylidene chloride polymers such process comprising (1) forming an admixture of a normally crystalline vinylidene chloride polymer in powder form with a blowing agent composed of a compound or mixture of compounds having a boiling point of less than about 40°C, a vapor pressure at the foaming temperature used of greater than atmospheric pressure and less than about 1000 p.s.i. and a solubility parameter of greater than about 6.6 and less than about 8.7, then (2) extrusion foaming the admixture using an extrusion temperature of from about 120°C to about 150°C.
Inventors
- 👤 Kyung W. Suh
- 👤 Richard E. Skochdopole
- 👤 Malcolm E. Leduc
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:57
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; C08J9/12; C08J9/14; C08J9/143; C08J2327/00; C08J2327/02; C08J2327/04; C08J2327/08; Y; Y10; Y10S; Y10S521/00; Y10S521/91
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
113 words
A process for forming stable low density extruded foam from normally crystalline vinylidene chloride polymer such process comprising (1) admixing a normally crystalline vinylidene chloride polymer in comminuted form with from about 5 to about 25 percent based on polymer weight of a blowing agent composed of a compound or compound mixture having a boiling point of less than about 40° C, a vapor pressure at the foaming temperature used of greater than atmospheric pressure but less than about 1000 p.s.i. and a solubility parameter of greater than about 6.6 and less than about 8.7, then (2) extrusion foaming the admixture using an extrusion temperature of from about 120°C to about 150° C.
Claim 2
Dependent Claim
113 words
A process for forming stable low density extruded foam from normally crystalline vinylidene chloride polymer such process comprising (1) admixing a normally crystalline vinylidene chloride polymer in comminuted form with from about 5 to about 25 percent based on polymer weight of a blowing agent composed of a compound or compound mixture having a boiling point of less than about 40° C, a vapor pressure at the foaming temperature used of greater than atmospheric pressure but less than about 1000 p.s.i. and a solubility parameter of greater than about 6.6 and less than about 8.7, then (2) extrusion foaming the admixture using an extrusion temperature of from about 120°C to about 150° C.
Claim 3
Dependent Claim
21 words
The process of claim 1 wherein said normally crystalline vinylidene chloride polymer is a copolymer of vinylidene chloride and vinyl chloride.
Claim 4
Dependent Claim
27 words
The process of claim 2 wherein said copolymer is a copolymer of about 85 percent by weight vinylidene chloride and about 15 percent by weight vinyl chloride.
Claim 5
Dependent Claim
36 words
A foamed structure prepared by the process of claim 1 and characterized by a density of less than about 15 pounds per cubic foot and an average cell size of about 0.1 to about 1 mm.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-09-28 | 1980-03-29 | 1980-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-09-28 | 1984-03-29 | 1984-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-09-28 | 1988-03-29 | 1988-09-28 | $7700.00 | Window Closed / Lapsed |