US5380813A
Expired / Lapsed
US
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Method for producing lactic acid based polyurethane
Assignee: Neste Oyj
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Filing: 1993-10-15
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Granted: 1995-01-10
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Expires: 2013-10-15
Abstract
Abstract The present invention relates to a production method of lactic acid-based polyurethanes. In the first phase of the product ion, the monomeric lactic acid is polymerized into an oligomer, the molecular weight thereof being about 500 to 10,000. Next, the oligomer thus obtained is copolymerized with an isocyanate reacting with the free hydroxyl and carboxyl groups thereof into polyurethane with a high molecular weight. To make the oligomer react with diol prior to the copolymerization is unnecessary according to the invention. The lactic acid used need not be absolutely pure, and by modifying the process, various biodegradable end products can be obtained therefrom, which according to the invention are appropriate for the material of disposable packages, agricultural film or planting pots, or as a coating of fertilizer granules.
Inventors
- 👤 Jukka Seppala
- 👤 Johan-Fredrik Selin
- 👤 Tao Su
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:52
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/40; C08G18/42; C08G18/4266; C08G18/4283; C08G2230/00; C08G2310/00
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
56 words
A method for producing lactic acid based polyurethane, comprising the steps of polymerizing monomeric lactic acid into an oligomer with a first molecular weight, and thereafter copolymerizing the oligomer with diisocyanate reacting with the free hydroxyl and carboxyl groups of it to form a polyurethane with a second molecular weight higher than said first molecular weight.
Claim 2
Independent Claim
56 words
A method for producing lactic acid based polyurethane, comprising the steps of polymerizing monomeric lactic acid into an oligomer with a first molecular weight, and thereafter copolymerizing the oligomer with diisocyanate reacting with the free hydroxyl and carboxyl groups of it to form a polyurethane with a second molecular weight higher than said first molecular weight.
Claim 3
Dependent Claim
22 words
Method according to claim 1, wherein the molecular weight of the oligomer obtained as an intermediate product is about 500 to 10,000.
Claim 4
Dependent Claim
32 words
Method according to claim 1, wherein about 5 to 70 percent by weight of isocyanate and about 30 to 95 percent by weight of lactic acid oligomer are copolymerized to become polyurethane.
Claim 5
Dependent Claim
17 words
Method according to claim 1, wherein the isocyanate is hexamethyl diisocyanate, diphenyl methane di-isocyanate, or toluene diisocyanate.
Claim 6
Dependent Claim
20 words
Method according to claim 1, wherein the copolymerization is accomplished at 50° to 200° C., preferably 80° to 160° C.
Claim 7
Dependent Claim
13 words
Method according to claim 1, wherein the copolymerization is accomplished without a catalyst.
Claim 8
Dependent Claim
16 words
Method according to claim 1, wherein stannous octoate is used as a catalyst in the copolymerization.
Claim 9
Dependent Claim
25 words
Method according to claim 1, wherein said monomeric lactic acid is provided in the form of a composition that includes sugar or an organic acid.
Claim 10
Dependent Claim
65 words
A material for disposable packages, said material being comprised of a lactic acid based polyurethane in which a monomeric lactic acid is first polymerized into an oligomer with a first molecular weight, and thereafter the oligomer is copolymerized with di-isocyanate reacting with the free hydroxyl and carboxyl groups of it to form a polyurethane with a second molecular weight higher than said first molecular weight.
Claim 11
Dependent Claim
65 words
A material for disposable packages, said material being comprised of a lactic acid based polyurethane in which a monomeric lactic acid is first polymerized into an oligomer with a first molecular weight, and thereafter the oligomer is copolymerized with di-isocyanate reacting with the free hydroxyl and carboxyl groups of it to form a polyurethane with a second molecular weight higher than said first molecular weight.
Claim 12
Dependent Claim
68 words
A material for agricultural film or planting pots, said material being comprised of a lactic acid based polyurethane in which a monomeric lactic acid is first polymerized into an oligomer with a first molecular weight, and thereafter the oligomer is copolymerized with di-isocyanate reacting with the free hydroxyl and carboxyl groups of it to form a polyurethane with a second molecular weight higher than said first molecular weight.
Claim 13
Dependent Claim
68 words
A material for agricultural film or planting pots, said material being comprised of a lactic acid based polyurethane in which a monomeric lactic acid is first polymerized into an oligomer with a first molecular weight, and thereafter the oligomer is copolymerized with di-isocyanate reacting with the free hydroxyl and carboxyl groups of it to form a polyurethane with a second molecular weight higher than said first molecular weight.
Claim 14
Dependent Claim
65 words
A coating of fertilizer granules, said coating being comprised of a lactic acid based polyurethane in which a monomeric lactic acid is first polymerized into an oligomer with a first molecular weight, and thereafter the oligomer is copolymerized with di-isocyanate reacting with the free hydroxyl and carboxyl groups of it to form a polyurethane with a second molecular weight higher than said first molecular weight.
Claim 15
Dependent Claim
65 words
A coating of fertilizer granules, said coating being comprised of a lactic acid based polyurethane in which a monomeric lactic acid is first polymerized into an oligomer with a first molecular weight, and thereafter the oligomer is copolymerized with di-isocyanate reacting with the free hydroxyl and carboxyl groups of it to form a polyurethane with a second molecular weight higher than said first molecular weight.
Claim 16
Dependent Claim
12 words
The method of claim 8 wherein the lactic acid composition includes glucose.
Claim 17
Dependent Claim
16 words
The method of claim 12 wherein the glucose-containing lactic acid composition is prepared by fermenting glucose.
Claim 18
Dependent Claim
13 words
The method of claim 8 wherein the lactic acid composition includes succinic acid.
References Cited (Backward Citations)
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) | 1998-01-09 | 1998-07-11 | 1999-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-01-09 | 2002-07-11 | 2003-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-01-09 | 2006-07-11 | 2007-01-10 | $7700.00 | Window Closed / Lapsed |