US4205114A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat and grease resistant containers comprising poly (p-methylstyrene)
Assignee: Mobil Oil AS
•
Filing: 1978-11-16
•
Granted: 1980-05-27
•
Expires: 1998-11-16
Abstract
Abstract There are provided shaped articles, such as trays and food containers, thermoformed from oriented poly (p-methylstyrene) sheet, oriented foamed poly (p-methylstyrene) film with oriented poly (p-methylstyrene) foam or polystyrene foam, that have been cross-linked by exposure to radiation. Such articles are resistant to fats and fatty foods contained therein can be placed in microwave ovens without destruction by hot, melted fats. The articles can also withstand conventional oven temperatures.
Inventors
- 👤 Peter J. Canterino
- 👤 Harold A. Arbit
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:04
CPC Classifications
B; B29; B29C; B29C71/00; B29C71/04; B32; B32B; B32B27/00; B32B27/30; B32B27/302; B32B27/06; B32B27/065; B32B27/16; B32B5/00; B32B5/18; B65; B65D; B65D81/00; B65D81/34; B65D81/3446; B29C35/00; B29C35/02; B29C35/08; B29C35/0805; B29C2035/0844; B29C2035/085; B29C35/0866; B29C2035/0877; B29C51/00; B29K; B29K2025/00; B29K2105/00; B29K2105/04; B29L; B29L2031/00; B29L2031/712; B32B2266/00; B32B2266/02; B32B2266/0214; B32B2266/0221; B32B2266/0228; B32B2439/00; B32B2439/70; B65D2581/00; B65D2581/34; B65D2581/3401; B65D2581/3402; B65D2581/3416; B65D2581/3417; Y; Y10; Y10S; Y10S264/00; Y10S264/18; Y10S428/00; Y10S428/91; Y10S521/00; Y10S521/915; Y10T; Y10T428/00; Y10T428/13; Y10T428/1352; Y10T428/1376; Y10T428/249921; Y10T428/249953; Y10T428/249987; Y10T428/249991; Y10T428/249992
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
32 words
Thermoformed and irradiated with ionizing radiation at a dose between about 30 megarads and about 70 megarads shaped articles of poly (p-methylstyrene) for use as food containers which are resistant to fats.
Claim 2
Dependent Claim
32 words
Thermoformed and irradiated with ionizing radiation at a dose between about 30 megarads and about 70 megarads shaped articles of poly (p-methylstyrene) for use as food containers which are resistant to fats.
Claim 3
Dependent Claim
17 words
The shaped articles of claim 1, wherein the poly (p-methylstyrene) is in the form of foam sheet.
Claim 4
Dependent Claim
29 words
The shaped articles of claim 1, wherein the poly (p-methylstyrene) is in the form of a laminate of poly (p-methylstyrene) film laminated on foamed polystyrene or poly (p-methylstyrene) sheet.
Claim 5
Dependent Claim
16 words
The shaped articles of claim 1, wherein the poly (p-methylstyrene) is in the form of sheet.
Claim 6
Independent Claim
48 words
The method for producing shaped articles adaptable for use as food containers which are resistant to fats, that comprises thermoforming sheet material containing poly (p-methylstyrene) to produce a shaped article and subjecting said article to ionizing radiation at a dose between about 30 megarads and about 70 megarads.
Claim 7
Independent Claim
48 words
The method for producing shaped articles adaptable for use as food containers which are resistant to fats, that comprises thermoforming sheet material containing poly (p-methylstyrene) to produce a shaped article and subjecting said article to ionizing radiation at a dose between about 30 megarads and about 70 megarads.
Claim 8
Dependent Claim
12 words
The method of claim 5, wherein said sheet material is foamed poly(p-methylstyrene).
Claim 9
Dependent Claim
21 words
The method of claim 5, wherein said sheet material is poly(p-methylstyrene) film laminated on foamed polystyrene sheet or foamed poly(p-methylstyrene) sheet.
Claim 10
Dependent Claim
12 words
The method of claim 5, wherein said sheet material is poly(p-methylstyrene) sheet.
References Cited (Backward Citations)
US2857625A
Cited
US3060513A
Cited
US3242238A
Cited
US3515615A
Cited
US3331899A
Cited
US3640913A
Cited
US3725317A
Cited
US3832312A
Cited
US4085073A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-05-27 | 1983-11-26 | 1984-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-05-27 | 1987-11-26 | 1988-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-05-27 | 1991-11-26 | 1992-05-27 | $7700.00 | Window Closed / Lapsed |