US4133784A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Biodegradable film compositions prepared from starch and copolymers of ethylene and acrylic acid
Assignee: United States Department of Agriculture
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Filing: 1977-09-28
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Granted: 1979-01-09
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Expires: 1997-09-28
Abstract
Abstract Biodegradable film compositions which will withstand outdoor exposure for a desired time and then disintegrate are prepared from starch and ethylene acrylic acid copolymers. These film compositions are useful for agricultural mulch and heat-sealable packaging.
Inventors
- 👤 Felix H. Otey
- 👤 Richard P. Westhoff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 02:07
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/18; C08L; C08L3/00; C08J2303/00; C08J2303/02; C08J2323/00; C08J2323/02; C08J2323/04; C08J2323/08
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
23 words
A flexible, self-supporting, and biodegradable film composition comprising a dry composite of a starchy material and a water-dispersible ethylene acrylic acid (EAA) copolymer.
Claim 2
Dependent Claim
23 words
A flexible, self-supporting, and biodegradable film composition comprising a dry composite of a starchy material and a water-dispersible ethylene acrylic acid (EAA) copolymer.
Claim 3
Dependent Claim
25 words
A composition as described in claim 1 wherein said starchy material is selected from the group consisting of unmodified starches, modified starches, amylose, and amylopectin.
Claim 4
Dependent Claim
28 words
A composition as described in claim 1 wherein said starchy material is an unmodified starch selected from the group consisting of cereal grain starches and root crop starches.
Claim 5
Dependent Claim
39 words
A composition as described in claim 1 wherein the amount of starchy material is in the range of 10-90% and the amount of EAA is in the range of 90-10%, both based on the dry weight of said composition.
Claim 6
Dependent Claim
39 words
A composition as described in claim 1 wherein the amount of starchy material is in the range of 20-60% and the amount of EAA is in the range of 80-40%, both based on the dry weight of said composition.
Claim 7
Dependent Claim
36 words
A composition as described in claim 5 wherein the amount of EAA is at least 20% based on the dry weight of said composition and said composition is further characterized by the property of being heat-sealable.
Claim 8
Dependent Claim
25 words
A composition as described in claim 1 and further comprising paraformaldehyde in an amount of about 2% based on the dry weight of said composition.
Claim 9
Dependent Claim
25 words
A composition as described in claim 1 and further comprising stearic acid in an amount of 1-5% based on the dry weight of said composition.
Claim 10
Independent Claim
47 words
A method of producing a flexible, self-supporting, and biodegradable film composite comprising the steps of: a. providing an aqueous dispersion of a starchy material and an ethylene acrylic acid (EAA) copolymer; b. heating said dispersion; c. forming said dispersion into a film; and d. drying said film.
Claim 11
Independent Claim
47 words
A method of producing a flexible, self-supporting, and biodegradable film composite comprising the steps of: a. providing an aqueous dispersion of a starchy material and an ethylene acrylic acid (EAA) copolymer; b. heating said dispersion; c. forming said dispersion into a film; and d. drying said film.
Claim 12
Dependent Claim
40 words
The method as described in claim 9 wherein said starchy material provided in step (a) is gelatinized and said heating in step (b) is at a temperature in the range of 50°-100° C. for a time period of 0.5-1 hour.
Claim 13
Dependent Claim
46 words
The method as described in claim 9 wherein said starchy material provided in step (a) is granular and said heating in step (b) is at a temperature in the range of 60°-100° C. for a time period of 0.5-2 hours whereby said granular starch becomes gelatinized.
Claim 14
Dependent Claim
42 words
The method as described in claim 9 wherein in step (a) the amount of starchy material is in the range of 10-90% and the amount of EAA is in the range of 90-10%, both based on the dry weight of said composition.
Claim 15
Dependent Claim
42 words
The method as described in claim 9 wherein in step (a) the amount of starchy material is in the range of 20-60% and the amount of EAA is in the range of 80-40%, both based on the dry weight of said composition.
Claim 16
Dependent Claim
17 words
The method as described in claim 9 wherein said forming in step (c) is effected by casting.
Claim 17
Dependent Claim
17 words
The method as described in claim 9 wherein said forming in step (c) is effected by extrusion.
Claim 18
Independent Claim
54 words
A method of producing a flexible, self-supporting, and biodegradable film composite comprising the steps of: a. providing a dry mix of a starchy material and an ethylene acrylic acid (EAA) copolymer; b. milling said dry mix at a plasticizing temperature to provide a plasticized matrix; and c. rolling said plasticized matrix into a film.
Claim 19
Independent Claim
54 words
A method of producing a flexible, self-supporting, and biodegradable film composite comprising the steps of: a. providing a dry mix of a starchy material and an ethylene acrylic acid (EAA) copolymer; b. milling said dry mix at a plasticizing temperature to provide a plasticized matrix; and c. rolling said plasticized matrix into a film.
Claim 20
Dependent Claim
17 words
The method as described in claim 16 wherein said starchy material provided in step (a) is gelatinized.
Claim 21
Dependent Claim
17 words
The method as described in claim 16 wherein said starchy material provided in step (a) is granular.
Claim 22
Dependent Claim
42 words
The method as described in claim 16 wherein in step (a) the amount of starchy material is in the range of 10-90% and the amount of EAA is in the range of 90-10%, both based on the dry weight of said composition.
Claim 23
Dependent Claim
42 words
The method as described in claim 16 wherein in step (a) the amount of starchy material is in the range of 20-60% and the amount of EAA is in the range of 80-40%, both based on the dry weight of said composition.
Claim 24
Dependent Claim
22 words
The method as described in claim 16 wherein said plasticizing temperature in step (b) is in the range of about 120°-135° C.
References Cited (Backward Citations)
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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) | 1982-01-08 | 1982-07-10 | 1983-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-01-08 | 1986-07-10 | 1987-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-01-08 | 1990-07-10 | 1991-01-09 | $7700.00 | Window Closed / Lapsed |