US5235031A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polymerization of lactide
Assignee: Ecological Chemical Products
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Filing: 1992-03-13
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Granted: 1993-08-10
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Expires: 2012-03-13
Abstract
Abstract A process for polymerizing lactide and up to 20 mole percent of another lactone in the absence of solvent at 100° to 220° C. using an yttrium or lanthanide series rare earth metal catalyst.
Inventors
- 👤 Neville E. Drysdale
- 👤 Thomas M. Ford
- 👤 Stephan J. McLain
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:35
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/78; C08G63/82; C08G63/823
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
128 words
A process for polymerizing lactide comprising melting at 100° to 220° C. a lactide and up to 20 mole percent of another lactone of the formula ##STR5## where n is 4 or 5, h, i, k and m are independently 1 or 2, each R is independently selected from H or hydrocarbyl containing up to 12 carbon atoms or substituted hydrocarbyl containing up to 12 carbon atoms with a catalyst of the formula MZ 3 , wherein M is yttrium or a rare earth metal and one Z is --OCR' 3 where R' is independently hydrogen, hydrocarbyl or substituted hydrocarbyl, the remaining two Zs are fluoride, chloride, bromide, iodide, carboxylate, tetrasubstituted porphyrinato (-2), betadiketone anions, beta keto ester anions, cyclopentadienide, phenoxide or pentamethylcyclopentadienide, and cooling the resulting polymer.
Claim 2
Dependent Claim
128 words
A process for polymerizing lactide comprising melting at 100° to 220° C. a lactide and up to 20 mole percent of another lactone of the formula ##STR5## where n is 4 or 5, h, i, k and m are independently 1 or 2, each R is independently selected from H or hydrocarbyl containing up to 12 carbon atoms or substituted hydrocarbyl containing up to 12 carbon atoms with a catalyst of the formula MZ 3 , wherein M is yttrium or a rare earth metal and one Z is --OCR' 3 where R' is independently hydrogen, hydrocarbyl or substituted hydrocarbyl, the remaining two Zs are fluoride, chloride, bromide, iodide, carboxylate, tetrasubstituted porphyrinato (-2), betadiketone anions, beta keto ester anions, cyclopentadienide, phenoxide or pentamethylcyclopentadienide, and cooling the resulting polymer.
Claim 3
Dependent Claim
18 words
The process of claim 1 wherein the mole ratio of monomer to catalyst is from 500 to 20,000.
Claim 4
Dependent Claim
11 words
The process of claim 2 wherein a lactide homopolymer is produced.
Claim 5
Dependent Claim
18 words
The process of claim 1 wherein the R in the lactone co-monomer is H or CH 3 .
Claim 6
Dependent Claim
18 words
The process of claim 4 wherein the mole ratio of monomer to catalyst is from 500 to 20,000.
Claim 7
Dependent Claim
16 words
The process of claim 1 wherein the lactone co-monomer is epsilon-caprolactone, delta-valerolactone, glycolide, 1,5-dioxepan-2-one or 1,4-dioxan-2-one.
Claim 8
Dependent Claim
18 words
The process of claim 6 wherein the mole ratio of monomer to catalyst is from 500 to 20,000.
Claim 9
Dependent Claim
16 words
The process of claim 1 wherein the polymerization is carried out at 110° to 200° C.
Claim 10
Dependent Claim
15 words
The process of claim 1 wherein two of the -Zs are 2,2,6,6,-tetramethylheptane dionato, or acetylacetonate.
Claim 11
Dependent Claim
14 words
The process of claim 9 wherein the third -Z is isopropoxy, 2-ethoxyethoxy or 2-(N,N-dimethylamino)ethoxy.
Claim 12
Dependent Claim
9 words
The process of claim 1 wherein M is lanthanum.
Claim 13
Dependent Claim
9 words
The process of claim 9 wherein M is lanthanum.
Claim 14
Dependent Claim
15 words
The process of claim 12 wherein the third Z is isopropoxy, 2-ethoxy ethoxy, or 2-N,N-dimethylethoxy.
Claim 15
Dependent Claim
16 words
The process of claim 1 wherein the polymerization is carried out at 165° to 180° C.
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) | 1996-08-09 | 1997-02-08 | 1997-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-08-09 | 2001-02-08 | 2001-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-08-09 | 2005-02-08 | 2005-08-10 | $7700.00 | Window Closed / Lapsed |