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US4572852A
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Thermoforming partially crystalline polyester articles
Assignee: Corpus Christi Polymers LLC
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Filing: 1984-11-05
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Granted: 1986-02-25
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Expires: 2004-11-05
Abstract
Abstract Thin walled thermoformed articles of partially crystallized polyethylene terephthalate containing a minor component of a polyolefin which exhibit improved impact resistance and high temperature dimensional stability are disclosed herein. A method for thermoforming such articles using polyethylene terephthalate/polyolefin blends which provides improved mold release is also revealed.
Inventors
- 👤 Robert J. Gartland
- 👤 Joseph N. Feil
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:22
CPC Classifications
C; C08; C08L; C08L67/00; C08L67/02; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/1352; Y10T428/1397; Y10T428/31504; Y10T428/31786
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
96 words
A thermoformed, non-oriented, heat set, thin wall article, the composition consisting of: (A) from about 99 to about 90 weight percent of polyethylene terephthalate with an intrinsic viscosity as measured in a 60/40 by volume mixed solvent of phenol/tetrachloroethane at 30° C. from about 0.65 to about 1.2: and (B) from about 1 to about 10 weight percent of a polyolefin with repeat units derived from olefin monomers containing 2 to 6 carbon atoms; and (C) an effective amount of a heat stabilizer; said article having a total crystallinity of from about 10 to about 40%.
Claim 2
Dependent Claim
96 words
A thermoformed, non-oriented, heat set, thin wall article, the composition consisting of: (A) from about 99 to about 90 weight percent of polyethylene terephthalate with an intrinsic viscosity as measured in a 60/40 by volume mixed solvent of phenol/tetrachloroethane at 30° C. from about 0.65 to about 1.2: and (B) from about 1 to about 10 weight percent of a polyolefin with repeat units derived from olefin monomers containing 2 to 6 carbon atoms; and (C) an effective amount of a heat stabilizer; said article having a total crystallinity of from about 10 to about 40%.
Claim 3
Dependent Claim
20 words
An article as described in claim 1 wherein said polyolefin is selected from the group consisting of polyethylene and polypropylene.
Claim 4
Dependent Claim
25 words
An article as described in claim 2 wherein from about 0.005 to about 2.0 weight percent of said heat stabilizer is present in said composition.
Claim 5
Dependent Claim
25 words
An article as described in claim 3 wherein said heat stabilizer is a polyphenol selected from the group consisting of 1,3,5-Trimethyl-2,4,6-tris(3,5-di-t butyl-4-hydroxybenzyl)benzene, and tetrakis(methylene3-(3,5-ditertiary butyl-4-hydroxyphenyl)-propionate)methane.
Claim 6
Dependent Claim
25 words
An article as described in claim 4 wherein from about 0.01 to about 0.5 weight percent of said heat stabilizer is present in said composition.
Claim 7
Dependent Claim
12 words
An article as specified in claim 5 wherein said polyolefin in polyethylene.
Claim 8
Dependent Claim
14 words
An article as specified in claim 6 wherein said article is a food container.
Claim 9
Dependent Claim
15 words
An article as specified in claim 7 wherein said polyolefin is linear low density polyethylene.
Claim 10
Dependent Claim
101 words
A thermoformed, non-oriented, heat set, thin walled article, the composition consisting of: (A) from about 99 to about 90 weight percent of polyethylene terephthalate with an intrinsic viscosity as measured in a 60/40 by volume mixed solvent of phenol/tetrachloroethane at 30° C. from about 0.65 to about 1.2; (B) from about 1 to about 10 weight percent of a polyolefin with repeat units derived from olefin monomers containing 2 to 6 carbon atoms; (C) an effective amount of a heat stabilizer; and (D) at least one non-nucleating colorant; said article having a total crystallinity of from about 10 to about 40%.
Claim 11
Dependent Claim
101 words
A thermoformed, non-oriented, heat set, thin walled article, the composition consisting of: (A) from about 99 to about 90 weight percent of polyethylene terephthalate with an intrinsic viscosity as measured in a 60/40 by volume mixed solvent of phenol/tetrachloroethane at 30° C. from about 0.65 to about 1.2; (B) from about 1 to about 10 weight percent of a polyolefin with repeat units derived from olefin monomers containing 2 to 6 carbon atoms; (C) an effective amount of a heat stabilizer; and (D) at least one non-nucleating colorant; said article having a total crystallinity of from about 10 to about 40%.
Claim 12
Dependent Claim
20 words
An article as described in claim 9 wherein said polyolefin is selected from the group consisting of polyethylene and polypropylene.
Claim 13
Dependent Claim
25 words
An article as described in claim 10 wherein from about 0.005 to about 2.0 weight percent of said heat stabilizer is present in said composition.
Claim 14
Dependent Claim
30 words
An article as specified in claim 9 wherein said non-nucleating colorant is selected from the group consisting of phthalocyanine blue, solvent red 135, and dispersed yellow 64 (CAS No. 10319-14-9).
Claim 15
Dependent Claim
12 words
An article as specified in claim 12 wherein said polyolefin is polyethylene.
Claim 16
Dependent Claim
25 words
An article as specified in claim 13 wherein said heat stabilizer is a polyphenol selected from the group consisting of 1,3,5-Trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl)benzene, and 3-(3,5-ditertiary butyl-4-hydroxyphenyl)-propionate)-methane.
Claim 17
Dependent Claim
25 words
An article as described in claim 14 wherein from about 0.01 to about 0.5 weight percent of said heat stabilizer is present in said composition.
Claim 18
Dependent Claim
14 words
An article as described in claim 15 wherein said article is a food container.
Claim 19
Dependent Claim
15 words
An article as specified in claim 16 wherein said polyolefin is linear low density polyethylene.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1989-02-24 | 1989-08-26 | 1990-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-24 | 1993-08-26 | 1994-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-24 | 1997-08-26 | 1998-02-25 | $7700.00 | Window Closed / Lapsed |