Patent US4873137A successfully refreshed from Google Patents.
US4873137A
Expired / Lapsed
US
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Food tray
Assignee: EIDP Inc
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Filing: 1988-06-02
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Granted: 1989-10-10
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Expires: 2008-06-02
Abstract
Abstract A composite structure comprising at least one core layer comprising polyethylene terephthalate and at least one outer layer on each side of the core layer, comprising polyethylene terephthalate and about 10 to about 60 percent glass flake, based on the weight of the outer layer, provides thermoformed articles with good high temperature stiffness and good surface properties.
Inventors
- 👤 Edward J. Deyrup
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:19
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; A; A47; A47J; A47J36/00; A47J36/02; A47J36/04; B32B27/18; B32B27/20; B32B27/36; B32B2367/00; B32B2439/00; B32B2439/70; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/24975; Y10T428/25; Y10T428/252; Y10T428/31504; Y10T428/31786; Y10T428/31797
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
65 words
A rigid composite structure comprising at least one core layer comprising a thermoplastic polymeric material and at least one outer layer on each side of the core layer comprising polyethylene terephthalate and about 10 to about 60 percent glass flake, based on the weight of the outer layers, wherein the core layer comprises about 25% to about 90% of the thickness of the composite structure.
Claim 2
Dependent Claim
65 words
A rigid composite structure comprising at least one core layer comprising a thermoplastic polymeric material and at least one outer layer on each side of the core layer comprising polyethylene terephthalate and about 10 to about 60 percent glass flake, based on the weight of the outer layers, wherein the core layer comprises about 25% to about 90% of the thickness of the composite structure.
Claim 3
Dependent Claim
14 words
The composite structure of claim 1 wherein the the core layer comprises polyethylene terephthalate.
Claim 4
Dependent Claim
14 words
The composite structure of claim 1 wherein the core layer comprises a barrier resin.
Claim 5
Dependent Claim
14 words
The composite structure of claim 1 wherein the core layer also contains regrind material.
Claim 6
Dependent Claim
20 words
The composite structure of claim 1 wherein the thickness of the core layer is about 0.05 to about 3.0 mm.
Claim 7
Dependent Claim
20 words
The composite structure of claim 5 wherein the thickness of the core layer is about 0.4 to about 1.3 mm.
Claim 8
Dependent Claim
18 words
The composite structure of claim 1 wherein the polyethylene terephthalate of the outer layers contains a branching agent.
Claim 9
Dependent Claim
21 words
The composite structure of claim 1 wherein the thickness of each outer layer is from about 0.04 to about 1.3 mm.
Claim 10
Dependent Claim
21 words
The composite structure of claim 8 wherein the thickness of the outer layer is from about 0.05 to about 0.80 mm.
Claim 11
Dependent Claim
21 words
The composite structure of claim 9 wherein the thickness of the outer layer is from about 0.05 to about 0.20 mm.
Claim 12
Dependent Claim
22 words
The composite structure of claim 1 wherein the glass flake has dimensions of about 0.002 to about 0.08 mm on a side.
Claim 13
Dependent Claim
15 words
The composite structure of claim 11 wherein the glass flake is soda lime borosilicate glass.
Claim 14
Dependent Claim
27 words
The composite structure of claim 11 wherein the outer layer contains from about 20 to about 50% glass flake, based on the weight of the outer layer.
Claim 15
Dependent Claim
27 words
The composite structure of claim 13 wherein the outer layers contain from about 25 to about 45% glass flake, based on the weight of the outer layer.
Claim 16
Dependent Claim
35 words
The composite structure of claim 1 wherein the outer layers contain 0 to about 40 percent, based on the the weight of the polymer components of the outer layer, of a low modulus polymeric material.
Claim 17
Dependent Claim
28 words
The composite structure of claim 15 wherein the low modulus polymeric material is a copolymer of methacrylic acid, alkyl acrylate, and at least about 50 mole percent ethylene.
Claim 18
Dependent Claim
27 words
The composite structure of claim 16 wherein the acid groups of the copolymer are partially converted to their salt form, the cation being a divalent metal ion.
Claim 19
Dependent Claim
13 words
The composite structure of claim 17 wherein the metal ion is zinc ion.
Claim 20
Dependent Claim
107 words
A composite structure comprising at least one core layer comprising a thermoplastic polymeric material, at least one outer layer on each side of the core layer comprising polyethylene terephthalate and about 10 to about 60 percent glass flake, based on the weight of the outer layers, and at least one layer of unreinforced polyethylene terephthalate overlying at least one outer layer of glass reinforced polyethylene terephthalate, wherein the thickness of the layer of unreinforced polyethylene terephthalate is less than about 10° of the total thickness of the composite structure and wherein the core layer comprises about 25° to about 90° of the thickness of the composite structure.
Claim 21
Dependent Claim
107 words
A composite structure comprising at least one core layer comprising a thermoplastic polymeric material, at least one outer layer on each side of the core layer comprising polyethylene terephthalate and about 10 to about 60 percent glass flake, based on the weight of the outer layers, and at least one layer of unreinforced polyethylene terephthalate overlying at least one outer layer of glass reinforced polyethylene terephthalate, wherein the thickness of the layer of unreinforced polyethylene terephthalate is less than about 10° of the total thickness of the composite structure and wherein the core layer comprises about 25° to about 90° of the thickness of the composite structure.
Claim 22
Dependent Claim
19 words
The composite structure of claim 2 further comprising at least one layer of a polymer having low oxygen permeability.
Claim 23
Dependent Claim
12 words
The composite structure of claim 1 in the form of a tray.
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) | 1992-10-09 | 1993-04-10 | 1993-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-09 | 1997-04-10 | 1997-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-09 | 2001-04-10 | 2001-10-10 | $7700.00 | Window Closed / Lapsed |