US4337181A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Biodegradable starch-based blown films
Assignee: United States Department of Agriculture
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Filing: 1980-01-17
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Granted: 1982-06-29
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Expires: 2000-01-17
Abstract
Abstract Film-forming formulations comprising starch, ethylene acrylic acid copolymer, and optionally polyethylene, can be blown into films upon neutralization of a portion of the copolymer acid functionality. The resultant biodegradable films have potential application as agricultural mulch, garbage bags, and various types of packaging.
Inventors
- 👤 Felix H. Otey
- 👤 Richard P. Westhoff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:27
CPC Classifications
C; C08; C08K; C08K5/00; C08K5/0008; C08K5/0033; C08J; C08J5/00; C08J5/18; C08L; C08L23/00; C08L23/02; C08L23/04; C08L23/06; C08L23/08; C08L23/0846; C08L23/0869; C08L3/00; C08L3/02; A; A61; A61F; A61F13/00; A61F13/15; A61F13/51; A61F13/514; A61F13/51401; A61F2013/51409; A61F2013/51433; C08J2323/00; C08J2323/02; C08J2323/04; C08J2323/08; Y; Y10; Y10S; Y10S260/00; Y10S260/43
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
106 words
In a method of producing a flexible, self-supporting, and biodegradable film wherein a mixture comprising a partially or completely gelatinized starchy material in an amount up to 60% by weight and an ethylene acrylic acid copolymer is converted into a plasticized matrix and then shaped into said film, the improvement comprising the following steps: a. incorporating into said matrix a neutralizing agent selected from the group of aqueous ammonia and anhydrous ammonia; b. adjusting the moisture content of said matrix to within the range of about 2-10% based on the weight of the matrix; and c. extrusion blowing said ammoniated and moisture-adjusted matrix into a film.
Claim 2
Dependent Claim
106 words
In a method of producing a flexible, self-supporting, and biodegradable film wherein a mixture comprising a partially or completely gelatinized starchy material in an amount up to 60% by weight and an ethylene acrylic acid copolymer is converted into a plasticized matrix and then shaped into said film, the improvement comprising the following steps: a. incorporating into said matrix a neutralizing agent selected from the group of aqueous ammonia and anhydrous ammonia; b. adjusting the moisture content of said matrix to within the range of about 2-10% based on the weight of the matrix; and c. extrusion blowing said ammoniated and moisture-adjusted matrix into a film.
Claim 3
Dependent Claim
15 words
The method as described in claim 1 and further comprising incorporating polyethylene into said matrix.
Claim 4
Dependent Claim
14 words
A flexible, self-supporting, a biodegradable film composition prepared by the process of claim 2.
Claim 5
Dependent Claim
69 words
A composition as described in claim 3 wherein the amount of starchy material is in the range of 10-60%, the amount of ethylene acrylic acid copolymer salt expressed in terms of its acid form is the range of 10-90%, and the amount of polyethylene is in the range of 10-80%, all based upon the combined dry weight of the starchy material, the ethylene acrylic acid copolymer, and the polyethylene.
Claim 6
Dependent Claim
29 words
The method as described in claim 1 wherein said neutralizing agent is incorporated into said matrix prior to adjusting the moisture content to within the range of step (b).
Claim 7
Dependent Claim
29 words
The method as described in claim 1 wherein said neutralizing agent is incorporated into said matrix subsequent to adjusting the moisture content to within the range of step (b).
Claim 8
Dependent Claim
53 words
The method as described in claim 1 wherein said mixture comprises an amount of starchy material in the range of about 10-60%, an amount of ethylene acrylic acid copolymer in the range of about 10-90%, and an amount of polyethylene in the range of about 0-80%, all based upon their combined dry weight.
Claim 9
Dependent Claim
14 words
A flexible, self-supporting, and biodegradable film composition prepared by the process of claim 1.
Claim 10
Dependent Claim
22 words
A composition as described in claim 8 wherein said starchy material is selected from the group consisting of unmodified starches and flour.
Claim 11
Dependent Claim
28 words
A composition as described in claim 8 wherein said starchy material is an unmodified starch selected from the group consisting of cereal grain starches and root crop starches.
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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) | 1985-06-28 | 1985-12-28 | 1986-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-06-28 | 1989-12-28 | 1990-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-06-28 | 1993-12-28 | 1994-06-29 | $7700.00 | Window Closed / Lapsed |