US4657715A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing smooth skinned extruded foams with water-organic blowing agent
Assignee: Pactiv LLC
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Filing: 1984-12-31
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Granted: 1987-04-14
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Expires: 2004-12-31
Abstract
Abstract Water instead of carbon dioxide is substituted for part of the volatile organic blowing agent, e.g., pentane, resulting in extruded foams having a smooth, lustrous drum side skin compared to foams containing only organic blowing agent or organic blowing agent plus carbon dioxide.
Inventors
- 👤 Donald W. Myers
- 👤 Dennis O'Brien
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:11
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; C08J9/12; C08J9/127; B; B29; B29C; B29C44/00; B29C44/34; B29C44/3442; B29C44/3446; B29C44/36; B29C44/46; B29C44/50; B29C44/507; B29K; B29K2025/00; B29L; B29L2023/00; C08J2203/00; C08J2203/14; C08J2325/00; C08J2325/02; C08J2325/04; C08J2325/06; Y; Y10; Y10S; Y10S264/00; Y10S264/05
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
73 words
A method for producing a thermoplastic foam sheet having a smooth, lustrous surface by extruding a foamed tube of thermoplastic material, water and a volatile organic blowing agent; drawing the foam tube over the cylindrical surface of a cooling drum; and slitting the tube; in which said smooth, lustrous surface is on the surface drawn over said cooling drum and has a smoothness and luster which is greater than obtained absent the water.
Claim 2
Independent Claim
73 words
A method for producing a thermoplastic foam sheet having a smooth, lustrous surface by extruding a foamed tube of thermoplastic material, water and a volatile organic blowing agent; drawing the foam tube over the cylindrical surface of a cooling drum; and slitting the tube; in which said smooth, lustrous surface is on the surface drawn over said cooling drum and has a smoothness and luster which is greater than obtained absent the water.
Claim 3
Dependent Claim
11 words
The method of claim 1 in which said thermoplastic is polystyrene.
Claim 4
Dependent Claim
17 words
The method of claim 1 in which said organic blowing agent is a hydrocarbon or halogenated hydrocarbon.
Claim 5
Dependent Claim
13 words
The method of claim 1 in which said organic blowing agent is isopentane.
Claim 6
Dependent Claim
11 words
The method of claim 3 in which said thermoplastic is polystyrene.
Claim 7
Dependent Claim
11 words
The method of claim 4 in which said thermoplastic is polystyrene.
Claim 8
Dependent Claim
20 words
The process of claim 1 in which the molar ratio of water to organic blowing agent is 0.1:1 to 0.5:1.
Claim 9
Dependent Claim
13 words
The process of claim 1 in which said thermoplastic includes a nucleating agent.
Claim 10
Dependent Claim
12 words
The process of claim 8 in which the nucleating agent is talc.
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) | 1990-04-13 | 1990-10-13 | 1991-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-13 | 1994-10-13 | 1995-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-04-13 | 1998-10-13 | 1999-04-14 | $7700.00 | Window Closed / Lapsed |