US6326440B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Biodegradable film and process for producing the same
Assignee: Mitsubishi Chemical Corp
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Filing: 1998-11-13
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Granted: 2001-12-04
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Expires: 2018-11-13
Abstract
Abstract A plastic film is provided in which brittleness has been improved, and which is not too soft, and which has practically satisfactory physical properties, heat-sealability stable with time, and biodegradability in natural environment. The film comprises a polylactic acid-family polymer and other aliphatic polyester at the ratio of 80:20 to 20:80, and the heat of fusion DELTAHm1 converted to the polylactic acid-family polymer when the temperature of the film is raised is 35 J/g or under.
Inventors
- 👤 Shigenori Terada
- 👤 Jun Takagi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:38
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/18; C08L; C08L67/00; C08L67/02; C08L67/04; Y; Y10; Y10S; Y10S525/00; Y10S525/938
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
71 words
A biodegradable film comprising a polylactic acid-family polymer whose fusion heat of crystal ΔHm 2 when secondary temperature raising is carried out is 3 J/g or under and other aliphatic polyester than the polylactic acid-family polymer at the weight ratio of 80:20 to 20:80, characterized in that the heat for fusion ΔHm1 converted to the polylactic acid-family polymer when the temperature of the film is raised is 35 J/g or under.
Claim 2
Dependent Claim
71 words
A biodegradable film comprising a polylactic acid-family polymer whose fusion heat of crystal ΔHm 2 when secondary temperature raising is carried out is 3 J/g or under and other aliphatic polyester than the polylactic acid-family polymer at the weight ratio of 80:20 to 20:80, characterized in that the heat for fusion ΔHm1 converted to the polylactic acid-family polymer when the temperature of the film is raised is 35 J/g or under.
Claim 3
Dependent Claim
96 words
The biodegradable film as claimed in claim 1 characterized in that the aliphatic polyester has a weight-average molecular weight of 20 to 300 thousand and has the structure expressed by the following formula (1) (wherein R1 and R2 are alkylene or cycloalkylene groups having 2 to 10 carbon atoms, n is the degree of polymerization required for the weight-average molecular weight to be 20-300 thousand, R1 or R2 may be identical to or different from each other, and in the formula, instead of ester-bound residue, urethane-bound residue and/or carbonate-bound residue may be contained up to 5%).
Claim 4
Dependent Claim
22 words
The biodegradable film as claimed in claim 2 wherein the glass transition point of said aliphatic polyester is 0° C. or lower.
Claim 5
Dependent Claim
22 words
The biodegradable film as claimed in claim 2 wherein the weight-average molecular weight of said aliphatic polyester is 150 to 250 thousand.
Claim 6
Dependent Claim
23 words
The biodegradable film as claimed in claim 2 wherein the weight-average molecular weight of said polylactic acid-family polymer is 100 to 300 thousand.
Claim 7
Dependent Claim
22 words
The biodegradable film as claimed in claim 1 wherein the glass transition point of said aliphatic polyester is 0° C. or lower.
Claim 8
Dependent Claim
22 words
The biodegradable film as claimed in claim 1 wherein the weight-average molecular weight of said aliphatic polyester is 150 to 250 thousand.
Claim 9
Dependent Claim
23 words
The biodegradable film as claimed in claim 1 wherein the weight-average molecular weight of said polylactic acid-family polymer is 100 to 300 thousand.
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) | 2004-12-03 | 2005-06-04 | 2005-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-12-03 | 2009-06-04 | 2009-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-12-03 | 2013-06-04 | 2013-12-04 | $7700.00 | Window Closed / Lapsed |