US5409751A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Degradable container
Assignee: Mitsui Chemicals Inc
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Filing: 1993-03-17
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Granted: 1995-04-25
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Expires: 2013-03-17
Abstract
Abstract A degradable container which is excellent in transparency and impact strength and can be decomposed into nontoxic water and carbon dioxide in the natural environment within a relatively short period can be obtained by using the process for molding a container of an arbitrary shape from a thermoplastic composition having polylactic acid of lactic acids or a copolymer of lactic acids and other hydroxycarboxylic acids as a main component, preforming the composition and thereafter molding the container in a temperature range from Tg to Tg+60 DEG C. on the basis of the glass transition temperature Tg of the thermoplastic polymer composition and under the condition of a draw ratio of 6 times or less.
Inventors
- 👤 Kazuhiko Suzuki
- 👤 Takayuki Watanabe
- 👤 Yasuhiro Kitahara
- 👤 Masanobu Ajioka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 03:09
CPC Classifications
B; B65; B65D; B65D65/00; B65D65/38; B65D65/46; B65D65/466; B29; B29C; B29C49/00; B29C49/0005; B29C49/0006; C; C08; C08L; C08L67/00; C08L67/04; B29K; B29K2067/00; B29K2067/04; B29K2067/046; B29K2995/00; B29K2995/0018; B29K2995/0026; B29K2995/0037; B29K2995/0063; B29K2995/0089; Y; Y02; Y02W; Y02W90/00; Y02W90/10; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/1352; Y10T428/139; Y10T428/1397
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
149 words
The impact resistant, biodegradable container having a light transmittance of 85% or more obtained by the process for molding a container of a shape from a thermoplastic polymer composition having a polymer of lactic acid or a copolymer of lactic acid and hydroxycarboxylic acids other than lactic acid as a main component having a molecular weight of 10,000 or more, the process comprising: (1) preforming the thermoplastic polymer composition into a preform in a temperature range of 180°-300° C., and thereafter (2) drawn blow molding the preform into a container in a temperature range of 20° to 125° C. which corresponds to the range of from Tg to Tg+60° C. on the basis of the glass transition temperature Tg of the thermoplastic polymer composition and at a draw ratio of 1.2 to 6 times, wherein the glass transition temperature Tg is in the range of 20° to 65° C.
Claim 2
Dependent Claim
149 words
The impact resistant, biodegradable container having a light transmittance of 85% or more obtained by the process for molding a container of a shape from a thermoplastic polymer composition having a polymer of lactic acid or a copolymer of lactic acid and hydroxycarboxylic acids other than lactic acid as a main component having a molecular weight of 10,000 or more, the process comprising: (1) preforming the thermoplastic polymer composition into a preform in a temperature range of 180°-300° C., and thereafter (2) drawn blow molding the preform into a container in a temperature range of 20° to 125° C. which corresponds to the range of from Tg to Tg+60° C. on the basis of the glass transition temperature Tg of the thermoplastic polymer composition and at a draw ratio of 1.2 to 6 times, wherein the glass transition temperature Tg is in the range of 20° to 65° C.
Claim 3
Dependent Claim
16 words
The container of claim 1 wherein the lactic lactic is a dimer of said lactic acid.
Claim 4
Dependent Claim
18 words
The container of claim 1 wherein the lactic acid is L-lactic acid, D-lactic acid or a mixture thereof.
Claim 5
Dependent Claim
12 words
The container of claim 1 wherein the hydroxycarboxylic acids is glycolic acid.
Claim 6
Dependent Claim
15 words
The container of claim 1 wherein said draw ratio is from 2 to 4 times.
Claim 7
Dependent Claim
26 words
The container of claim 1 wherein preforming is injection molding, the preform is a bottomed parison and the drawn blow molding is injection drawn blow molding.
Claim 8
Dependent Claim
25 words
The container of claim 1 wherein preforming is extrusion molding, the preform is a parison and the drawn blow molding is extrusion drawn blow molding.
Claim 9
Dependent Claim
16 words
The container of claim 1 wherein the container has a light transparency of at least 90%.
References Cited (Backward Citations)
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Cited
EP0321176B1
Cited
US5180765A
Cited
WO1992004413A1
Cited
US5191037A
Cited
US5206341A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-04-24 | 1998-10-24 | 1999-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-04-24 | 2002-10-24 | 2003-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-04-24 | 2006-10-24 | 2007-04-25 | $7700.00 | Window Closed / Lapsed |