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US5516883A Expired / Lapsed US ⏱️ 0.0 years remaining

Biodegradable optically active copolymer and process for producing the same

Assignee: Takasago International Corp
•
Filing: 1993-12-09
•
Granted: 1996-05-14
•
Expires: 2013-12-09
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Abstract

Abstract A biodegradable, optically active copolymer is disclosed. The copolymer is represented by general formula (I): ##STR1## wherein R 1 represents a group selected from the group consisting of methyldimethylene, 1,2-dimethyldimethylene, 1,1-dimethyldimethylene, methyltrimethylene, tetramethylene, methyltetramethylene, pentamethylene, 1,4-dimethyl-2-oxo-3-oxytetramethylene, 2-oxo-3-oxytetramethylene, and 2-methyl-3-oxypentamethylene, and m and n each represents a natural number of from 10 to 15,000. According to the present invention, useful polymers which are a new type of functional materials characterized as having optical activity, biodegradability (enzymatic degradability), and hydrolyzability can be easily produced in an industrially advantageous manner by the ring-opening copolymerization of optically active β-butyrolactone with various lactones.

Inventors

  • 👤 Yoji Hori
  • 👤 Akio Yamaguchi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 07:54
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/78; C08G63/82; C08G63/823; C08G63/02; C08G63/06; C08G63/08; C08G63/66; C08G63/664

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 60 words
A biodegradable, optically active copolymer represented by general formula (I): ##STR7## wherein R 1 represents a group selected from the group consisting of methyldimethylene, 1,2-dimethyldimethylene, 1,1-dimethyldimethylene, methyltrimethylene, tetramethylene, methyltetramethylene, pentamethylene, 1,4-dimethyl-2-oxo-3-oxytetramethylene, 2-oxo-3-oxytetramethylene, and 2-methyl-3-oxypentamethylene, and m and n each represents a natural number of from 10 to 15,000, said copolymer having a weight-average molecular weight of from 8,000 to 1,000,000.
Claim 2
Dependent Claim 60 words
A biodegradable, optically active copolymer represented by general formula (I): ##STR7## wherein R 1 represents a group selected from the group consisting of methyldimethylene, 1,2-dimethyldimethylene, 1,1-dimethyldimethylene, methyltrimethylene, tetramethylene, methyltetramethylene, pentamethylene, 1,4-dimethyl-2-oxo-3-oxytetramethylene, 2-oxo-3-oxytetramethylene, and 2-methyl-3-oxypentamethylene, and m and n each represents a natural number of from 10 to 15,000, said copolymer having a weight-average molecular weight of from 8,000 to 1,000,000.
Claim 3
Dependent Claim 30 words
A biodegradable, optically active copolymer as claimed in claim 1, wherein the ratio of the structural units (III) ##STR8## to the structural units (IV) ##STR9## ranges from 99:1 to 1:99.
Claim 4
Dependent Claim 53 words
A process for producing the biodegradable, optically active copolymer as claimed in claim 1, which comprises subjecting optically active β-butyrolactone and a four-, five-, six- or seven-membered lactone to ring-opening copolymerization in the presence of a catalyst which is selected from the group consisting of a tin compound catalyst and a distannoxane catalyst.
Claim 5
Dependent Claim 78 words
A process as claimed in claim 3, wherein the catalyst is a distannoxane catalyst represented by general formula (V): ##STR10## wherein R 2 represents either an alkyl group having from 1 to 4 carbon atoms or a phenyl group, X is selected from the group consisting of Cl, Br, and NCS, and Y is selected from the group consisting of Cl, Br, NCS, OH, an alkoxy group having from 1 to 4 carbon atoms, and a phenoxy group.
Claim 6
Dependent Claim 13 words
A process as claimed in claim 3, wherein the catalyst is dibutyltin oxide.

References Cited (Backward Citations)

US4320753A Cited
US4981696A Cited
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EP0509203A2 Cited
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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) 1999-05-14 1999-11-13 2000-05-14 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2003-05-14 2003-11-13 2004-05-14 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2007-05-14 2007-11-13 2008-05-14 $7700.00 Window Closed / Lapsed

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