US5288765A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Expanded articles of biodegradable plastics materials and a method for their production
Assignee: Spherilene SRL
•
Filing: 1992-11-04
•
Granted: 1994-02-22
•
Expires: 2012-11-04
Abstract
Abstract Expanded articles of biodegradable plastics are produced by the extrusion of a composition including starch, a polymer compatible with starch, in particular, an ethylene-acrylic acid copolymer and/or ethylene-vinyl alcohol copolymer, and an expanding agent. Preferably use is made of sodium bicarbonate as expanding agent in the presence of a polymeric acid.
Inventors
- 👤 Catia Bastioli
- 👤 Vittorio Bellotti
- 👤 Luciano Del Giudice
- 👤 Roberto Lombi
- 👤 Angelos Rallis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:07
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/0061; C08L; C08L23/00; C08L23/02; C08L23/04; C08L23/08; C08L23/0846; C08L3/00; C08L3/02; C08J2303/00; C08J2303/02; C08J2403/00; C08L2205/00; C08L2205/03; C08L23/0853; C08L23/0861; C08L23/0869; C08L29/00; C08L29/02; C08L29/04; Y; Y10; Y10S; Y10S521/00; Y10S521/916
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
46 words
Expanded articles of biodegradable plastics material comprising a material including starch and a synthetic polymer selected from the group consisting of ethylene-vinyl alcohol, ethylene-acrylic acid, and mixtures thereof, said articles having a closed pore structure and a density of from 0.1 to 0.3 g/cm 3 .
Claim 2
Dependent Claim
46 words
Expanded articles of biodegradable plastics material comprising a material including starch and a synthetic polymer selected from the group consisting of ethylene-vinyl alcohol, ethylene-acrylic acid, and mixtures thereof, said articles having a closed pore structure and a density of from 0.1 to 0.3 g/cm 3 .
Claim 3
Dependent Claim
32 words
Expanded articles according to claim 1, wherein the ethylene-vinyl alcohol copolymer has an ethylene content of from 10 to 40% by weight and a melt flow index of from 6 to 20.
Claim 4
Dependent Claim
36 words
Expanded articles according to claim 1, wherein the ethylene-acrylic acid copolymer is produced by the copolymerization of a mixture including from 3 to 30% by weight of acrylic acid and from 97 to 70% of ethylene.
Claim 5
Dependent Claim
22 words
Expanded articles according to claim 1, wherein the starch and the copolymer are in a weight ratio of from 1:4 to 4:1.
Claim 6
Dependent Claim
13 words
Expanded articles according to claim 1, further including urea and/or a high-boiling plasticizer.
Claim 7
Dependent Claim
24 words
Expanded articles according to claim 1, further including a polymeric acid selected from the group consisting of polyacrylic acid, and ethylene-acrylic acid-vinyl alcohol copolymer.
Claim 8
Dependent Claim
19 words
Expanded articles according to claim 1, including a filler consisting of granular pyrolized foamed starch or hollow glass microspheres.
Claim 9
Independent Claim
50 words
A method for the production of expanded articles of biodegradable plastics material, comprising the step of extruding a composition including starch and a synthetic polymer selected from the group consisting of ethylene-vinyl alcohol and ethylene-acrylic acid in the presence of a polymeric acid and sodium bicarbonate as the expanding agent.
Claim 10
Independent Claim
50 words
A method for the production of expanded articles of biodegradable plastics material, comprising the step of extruding a composition including starch and a synthetic polymer selected from the group consisting of ethylene-vinyl alcohol and ethylene-acrylic acid in the presence of a polymeric acid and sodium bicarbonate as the expanding agent.
Claim 11
Dependent Claim
33 words
A method according to claim 8, wherein the synthetic polymer is ethylene-vinyl alcohol and the polymeric acid is selected from the group consisting of polyacrylic acid, ethylene-acrylic acid, and ethylene-acrylic acid-vinyl alcohol copolymers.
Claim 12
Dependent Claim
35 words
A method according to claim 8 in which the copolymer is produced by a copolymerization of a mixture including from 3 to 30% by weight of acrylic acid and from 97 to 70% of ethylene.
Claim 13
Dependent Claim
33 words
A method according to claim 8 wherein the ethylene vinyl alcohol copolymer has an ethylene content of from 10 to 40% by weight and a melt flow index of from 6 to 20.
Claim 14
Dependent Claim
35 words
A method according to claim 8 wherein the quantity of sodium bicarbonate added is equal to at least 0.3 equivalents of the bicarbonate for each equivalent weight of free carboxyl groups in the polymeric acid.
Claim 15
Dependent Claim
22 words
A method according to claim 8, in which the starch and the copolymer are in a ratio of from 4:1 to 1:4.
Claim 16
Dependent Claim
32 words
A method according to claim 8, in which the composition includes a quantity of urea of up to 30% by weight of the total weight of the composition and/or a high-boiling plasticizer.
Claim 17
Dependent Claim
50 words
A method according to claim 8, wherein the synthetic polymer is ethylene-acrylic acid and the polymeric acid is the ethylene-acrylic acid synthetic polymer and wherein the composition is mixed in an extruder barrel heated to a temperature of between 100° C. and the temperature of thermal decomposition of the bicarbonate.
Claim 18
Dependent Claim
29 words
A method according to claim 8, in which the composition includes a quantity of water of from 10 to 25% by weight of the weight of the dry starch.
Claim 19
Dependent Claim
36 words
A method according to claim 8, wherein the synthetic polymer is ethylene-acrylic acid and the polymeric acid is selected from the group consisting of polyacrylic acid, the ethylene-acrylic acid synthetic polymer and ethylene-acrylic acid-vinyl alcohol copolymers.
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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) | 1997-02-21 | 1997-08-23 | 1998-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-02-21 | 2001-08-23 | 2002-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-02-21 | 2005-08-23 | 2006-02-22 | $7700.00 | Window Closed / Lapsed |