US5223546A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High polymer network
Assignee: Mitsui Chemicals Inc
•
Filing: 1992-04-17
•
Granted: 1993-06-29
•
Expires: 2012-04-17
Abstract
Abstract A degradable polymer network obtained by adding from 0.2 to 10 parts by weight of a foaming agent to 100 parts by weight of a polylactic acid-base resin composition comprising from 80 to 100% by weight of polylactic acid or a lactic acid-hydroxycarboxylic acid copolymer and from 0 to 20% by weight of a plasticizer, conducting melt-foaming extrusion of resulting mixture, and opening the foam cells in the extrudate. The high polymer network is characterized in suitable flexibility and hydrolyzability and thus useful as a material for absorbing oils and body fluids, screens for sunlight, heat-insulating materials, filter media and packaging materials; and does not accumulate as industrial wastes because of hydrolyzability in the natural environment, even though abandoned after use.
Inventors
- 👤 Kenji Morita
- 👤 Kohichi Uchiki
- 👤 Hosei Shinoda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:19
CPC Classifications
B; B29; B29C; B29C44/00; B29C44/34; B29C44/56; B29C44/5627; B29C44/5672; C; C08; C08J; C08J9/00; C08J9/04; C08J9/06; C08J9/10; C08J9/102; C08J9/103; C08J9/12; C08J2367/00; C08J2367/04
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
20 words
A degradable high polymer network having mesh structure comprising fibrous branches of polylactic acid or a lactic acid-hydroxycarboxylic acid copolymer.
Claim 2
Dependent Claim
20 words
A degradable high polymer network having mesh structure comprising fibrous branches of polylactic acid or a lactic acid-hydroxycarboxylic acid copolymer.
Claim 3
Dependent Claim
24 words
The degradable high polymer network of claim 1 wherein the polylactic acid essentially consists of an L-lactic acid unit or a D-lactic acid unit.
Claim 4
Dependent Claim
37 words
The degradable high polymer network of claim 1 wherein the polylactic acid comprises from 85 to less than 100% by mole of an L-lactic acid unit and less than 15% by mole of a D-lactic acid unit.
Claim 5
Dependent Claim
37 words
The degradable high polymer network of claim 1 wherein the polylactic acid comprises from 85 to less than 100% by mole of a D-lactic acid unit and less than 15% by mole of an L-lactic acid unit.
Claim 6
Dependent Claim
39 words
The degradable high polymer network of claim 1 wherein the lactic acid-hydroxycarboxylic acid copolymer comprises from 85 to less than 100% by mole of an L-lactic acid unit and less than 15% by mole of a glycolic acid unit.
Claim 7
Dependent Claim
39 words
The degradable high polymer network of claim 1 wherein the lactic acid-hydroxycarboxylic acid copolymer comprises from 85 to less than 100% by mole of a D-lactic acid unit and less than 15% by mole of a glycolic acid unit.
Claim 8
Dependent Claim
84 words
A degradable high polymer network having mesh structure comprising fibrous branches of the high polymer and obtained by the process comprising adding from 0.2 to 10 parts by weight of a foaming agent to 100 parts by weight of a polylactic acid-base resin composition comprising from 80 to 100% by weight of polylactic acid or a lactic acid-hydroxycarboxylic acid copolymer and from 0 to 20% by weight of a plasticizer, conducting melt-foaming extrusion of resulting mixture, and opening the foam cells in the extrudate.
Claim 9
Dependent Claim
84 words
A degradable high polymer network having mesh structure comprising fibrous branches of the high polymer and obtained by the process comprising adding from 0.2 to 10 parts by weight of a foaming agent to 100 parts by weight of a polylactic acid-base resin composition comprising from 80 to 100% by weight of polylactic acid or a lactic acid-hydroxycarboxylic acid copolymer and from 0 to 20% by weight of a plasticizer, conducting melt-foaming extrusion of resulting mixture, and opening the foam cells in the extrudate.
Claim 10
Dependent Claim
24 words
The degradable high polymer network of claim 7 wherein the polylactic acid essentially consists of an L-lactic acid unit or a D-lactic acid unit.
Claim 11
Dependent Claim
37 words
The degradable high polymer network of claim 7 wherein the polylactic acid comprises from 85 to less than 100% by mole of an L-lactic acid unit and less than 15% by mole of a D-lactic acid unit.
Claim 12
Dependent Claim
37 words
The degradable high polymer network of claim 7 wherein the polylactic acid comprises from 85 to less than 100% by mole of a D-lactic acid unit and less than 15% by mole of an L-lactic acid unit.
Claim 13
Dependent Claim
39 words
The degradable high polymer network of claim 7 wherein the lactic acid-hydroxycarboxylic acid copolymer comprises from 85 to less than 100% by mole of an L-lactic acid unit and less than 15% by mole of a glycolic acid unit.
Claim 14
Dependent Claim
39 words
The degradable high polymer network of claim 7 wherein the lactic acid-hydroxycarboxylic acid copolymer comprises from 85 to less than 100% by mole of a D-lactic acid unit and less than 15% by mole of a glycolic acid unit.
Claim 15
Dependent Claim
20 words
The degradable high polymer network of claim 12 wherein the plasticizer is lactic acid, a lactic acid oligomer or lactide.
Claim 16
Dependent Claim
16 words
The degradable high polymer network of claim 12 wherein the foaming agent is azodicarboxylic acid amide.
Claim 17
Dependent Claim
20 words
The degradable high polymer network of claim 7 wherein the plasticizer is lactic acid, a lactic acid oligomer or lactide.
Claim 18
Dependent Claim
16 words
The degradable high polymer network of claim 7 wherein the foaming agent is azodicarboxylic acid amide.
References Cited (Backward Citations)
US1995970A
Cited
JPS5147170A
Cited
US4181983A
Cited
EP0171603A1
Cited
US4702917A
Cited
US4719246A
Cited
US4766182A
Cited
JPH01104635A
Cited
WO1992001737A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-06-28 | 1996-12-28 | 1997-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-06-28 | 2000-12-28 | 2001-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-06-28 | 2004-12-28 | 2005-06-29 | $7700.00 | Window Closed / Lapsed |