US4157437A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Addition copolymers of lactide and glycolide and method of preparation
Assignee: Ethicon Inc
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Filing: 1978-06-12
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Granted: 1979-06-05
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Expires: 1998-06-12
Abstract
Abstract Relatively high molecular weight, fiber-forming, crystalline copolymers of lactide and glycolide are prepared in a two-stage polymerization process. In the first stage there is prepared a random copolymer of a major proportion of an optically active lactide with a minor proportion of glycolide or d,l-lactide. In the second stage, a major amount of glycolide and a minor amount of lactide monomers are admixed with the copolymer of the first stage and the polymerization resumed until there is obtained a high molecular weight addition copolymer of lactide and glycolide containing from about 50 to 75 wt percent of units derived from glycolide. The polymer is fiber-forming and useful in the preparation of absorbable surgical sutures.
Inventors
- 👤 Yuzi Okuzumi
- 👤 A. Darline Mellon
- 👤 David Wasserman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 00:56
CPC Classifications
A; A61; A61L; A61L17/00; A61L17/06; A61L17/10; A61L17/12; C; C08; C08G; C08G63/00; C08G63/02; C08G63/06; C08G63/08
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
151 words
A method for preparing a crystalline copolymer of lactide and glycolide containing from 50 to 75 wt percent glycolide which comprises: a. preparing a random copolymer comprising a major portion of an optically active lactide and a minor portion of a monomer selected from the group consisting of glycolide and d,1-lactide, and b. admixing with said random copolymer additional monomers comprising from 70 to 90 wt percent glycolide and 10 to 30 wt percent of an optically active lactide, the quantity of glycolide being sufficient to provide from 50 to 75 wt percent glycolide in the polymer-monomer mixture, and c. polymerizing said polymer-monomer mixture to obtain said crystalline copolymer of lactide and glycolide, said copolymer having an inherent viscosity determined as a 0.1% solution in hexafluoroisopropanol at 25° C. of at least about 1.20, a melting point of at least about 160° C. and a crystallinity of at least about 15%.
Claim 2
Independent Claim
151 words
A method for preparing a crystalline copolymer of lactide and glycolide containing from 50 to 75 wt percent glycolide which comprises: a. preparing a random copolymer comprising a major portion of an optically active lactide and a minor portion of a monomer selected from the group consisting of glycolide and d,1-lactide, and b. admixing with said random copolymer additional monomers comprising from 70 to 90 wt percent glycolide and 10 to 30 wt percent of an optically active lactide, the quantity of glycolide being sufficient to provide from 50 to 75 wt percent glycolide in the polymer-monomer mixture, and c. polymerizing said polymer-monomer mixture to obtain said crystalline copolymer of lactide and glycolide, said copolymer having an inherent viscosity determined as a 0.1% solution in hexafluoroisopropanol at 25° C. of at least about 1.20, a melting point of at least about 160° C. and a crystallinity of at least about 15%.
Claim 3
Dependent Claim
39 words
The method of claim 1 wherein said random copolymer comprises from 60 to 90 wt percent of optically active lactide and from 10 to 40 wt percent of another monomer selected from the group consisting of glycolide and d,1-lactide.
Claim 4
Dependent Claim
18 words
The method of claim 2 wherein the optically active lactide is L(-)-lactide and the other monomer is glycolide.
Claim 5
Dependent Claim
26 words
The method of claim 3 wherein the random copolymer comprises from 65 to 75 wt percent of L(-)-lactide and from 25 to 35 mol percent glycolide.
Claim 6
Dependent Claim
18 words
The method of claim 2 wherein the optically active lactide is L(-)-lactide and the other monomer is d,1-lactide.
Claim 7
Dependent Claim
26 words
The method of claim 5 wherein the random copolymer comprises from 65 to 75 wt percent of L(-)-lactide and from 25 to 35 wt percent d,1-lactide.
Claim 8
Dependent Claim
21 words
The method of claim 1 wherein the optically active lactide admixed with the random copolymer according to Step (b) is L(-)-lactide.
Claim 9
Dependent Claim
37 words
The method of claim 7 wherein the mixture of L(-)-lactide and glycolide admixed with the random copolymer according to Step (b) comprises from 80 to 90 wt percent glycolide and from 10 to 20 wt percent L(-)-lactide.
Claim 10
Dependent Claim
26 words
The method of claim 1 wherein the random copolymer is ground to produce a particulate material prior to admixing with additional monomers according to Step (b).
Claim 11
Dependent Claim
9 words
The copolymer product of the process of claim 1.
Claim 12
Dependent Claim
9 words
The copolymer product of the process of claim 3.
Claim 13
Dependent Claim
9 words
The copolymer product of the process of claim 6.
Claim 14
Dependent Claim
9 words
The copolymer product of the process of claim 8.
References Cited (Backward Citations)
US3297033A
Cited
US3442871A
Cited
US3422181A
Cited
US3636956A
Cited
US3867190A
Cited
US3839297A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-06-04 | 1982-12-04 | 1983-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-06-04 | 1986-12-04 | 1987-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-06-04 | 1990-12-04 | 1991-06-05 | $7700.00 | Window Closed / Lapsed |