Patent US5096941A successfully refreshed from Google Patents.
US5096941A
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US
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Environmentally degradable polyethylene composition
Assignee: Dow Chemical Co
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Filing: 1990-08-23
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Granted: 1992-03-17
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Expires: 2010-08-23
Abstract
Abstract A polymeric composition which degrades in the presence of oxygen either photochemically or thermo-oxidatively comprising a blend of polyethylene, e.g. low density polyethylene and cerium (III) stearate. This composition is especially useful in degradable food wrap and packaging and as an agricultural mulch film.
Inventors
- 👤 Robert M. Harnden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:23
CPC Classifications
C; C08; C08K; C08K5/00; C08K5/04; C08K5/09; C08K5/098
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
49 words
An environmentally degradable polymer-based composition which degrades by any one of thermo-oxidation, photo-oxidation and the combination thereof, comprising a major portion by weight of at least one polyethylene, said polymer-based composition having incorporated therein from 0.05 to 0.50 weight percent of cerium +3 stearate, which promotes thermo-oxidation and photo-oxidation.
Claim 2
Dependent Claim
49 words
An environmentally degradable polymer-based composition which degrades by any one of thermo-oxidation, photo-oxidation and the combination thereof, comprising a major portion by weight of at least one polyethylene, said polymer-based composition having incorporated therein from 0.05 to 0.50 weight percent of cerium +3 stearate, which promotes thermo-oxidation and photo-oxidation.
Claim 3
Dependent Claim
46 words
An environmentally degradable composition according to claim 1 wherein said polyethylene is selected from the group consisting of high density polyethylenes having a density of at least 0.94 grams per centimeter and a low density polyethylene having a density not greater than 0.94 grams per centimeter.
Claim 4
Dependent Claim
27 words
A composition in accordance with claim 2 wherein said high density polyethylene has a melt index of a range of from 0.05 to 100 decigrams per minute.
Claim 5
Dependent Claim
30 words
An environmentally degradable composition in accordance with claim 2 wherein said low density polyethylene has a melt index in the range from about 0.05 to about 100 decigrams per minute.
Claim 6
Dependent Claim
29 words
An environmentally degradable composition in accordance with claim 1 wherein said polyethylene comprises a copolymer of ethylene and at least one ethylenically unsaturated monomer which is copolymerizable with ethylene.
Claim 7
Independent Claim
74 words
A method of accelerating thermo-oxidative, photo-oxidative and a combination of photo- and thermo-oxidative degradation of polyethylene under exposure to environmental conditions selected from the group consisting of air and ultraviolet light, air and darkness, air and elevated temperatures and combinations of such environmental conditions, which comprises adding to said polyethylene prior to exposure from about 0.05 to about 0.5 weight percent of cerium +3 stearate, based on the total weight of the resulting composition.
Claim 8
Independent Claim
74 words
A method of accelerating thermo-oxidative, photo-oxidative and a combination of photo- and thermo-oxidative degradation of polyethylene under exposure to environmental conditions selected from the group consisting of air and ultraviolet light, air and darkness, air and elevated temperatures and combinations of such environmental conditions, which comprises adding to said polyethylene prior to exposure from about 0.05 to about 0.5 weight percent of cerium +3 stearate, based on the total weight of the resulting composition.
Claim 9
Dependent Claim
46 words
A method according to claim 6 wherein said polyethylene is selected from the group consisting of high density polyethylenes having a density of at least about 0.94 grams per centimeter and a low density polyethylene having a density not greater than about 0.94 grams per centimeter.
Claim 10
Dependent Claim
29 words
A method in accordance with claim 7 wherein said high density polyethylene has a melt index of a range of from about 0.05 to about 100 decigrams per minute.
Claim 11
Dependent Claim
28 words
A method in accordance with claim 7 wherein said low density polyethylene has a melt index in the range from about 0.05 to about 100 decigrams per minute.
Claim 12
Dependent Claim
41 words
A method in accordance with claim 6 wherein said polyethylene comprises a copolymer of ethylene and at least one ethylenically unsaturated monomer which is copolymerizable with ethylene, and wherein at least about 50% by weight of said copolymer comprises polyethylene units.
Claim 13
Dependent Claim
16 words
A method in accordance with claim 6 wherein said environmental conditions comprise air and ultraviolet light.
Claim 14
Dependent Claim
15 words
A method in accordance with claim 6 wherein said environmental conditions comprise air and darkness.
Claim 15
Dependent Claim
16 words
A method in accordance with claim 6 wherein said environmental conditions comprise air and elevated temperatures.
Claim 16
Dependent Claim
16 words
A method in accordance with claim 6 wherein said environmental conditions comprise darkness and elevated temperatures.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-03-17 | 1995-09-16 | 1996-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-03-17 | 1999-09-16 | 2000-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-03-17 | 2003-09-16 | 2004-03-17 | $7700.00 | Window Closed / Lapsed |