EP0400532A1
Expired / Lapsed
EP
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Polymer compositions for the production of articles of biodegradable platics material and methods for their preparation
Assignee: Novamont SpA
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Filing: 1990-05-28
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Granted: —
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Expires: 2010-05-28
Abstract
Abstract A polymer composition usable for the production of articles of biodegradable plastics material includes an ethylene/vinyl alcohol copolymer and destructured starch. Preferably, the composition is obtainable by mixing the ethylene/vinyl alcohol copolymer, in a heated extruder, with a starch component constituted by a destructured starch composition produced beforehand by mixing starch with a high-boiling plasticizer, such as glycerine and a destructuring agent, preferably constituted by urea, in an extruder. Alternatively, the composition can be obtained by mixing the ethylene/vinyl alcohol copolymer with starch and a plasticizer in an extruder, with water added as appropriate and possibly with a suitable destructuring agent. The composition is particularly useful for the production of films with good resistance to perforation and tearing and moulded articles with improved mechanical strength. The products made from this composition are also good oxygen and carbon dioxide barriers.
Inventors
- 👤 Catia Bastioli
- 👤 Vittorio Bellotti
- 👤 Luciano Del Giudice
- 👤 Roberto Lombi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 21:40
CPC Classifications
C; C08; C08L; C08L3/00; C08L3/02; C08L23/00; C08L23/02; C08L23/04; C08L23/08; C08L23/0846; C08L23/0853; C08L23/0861; C08L29/00; C08L29/02; C08L29/04; C08L2205/00; C08L2205/03; C08L23/0869; C08L71/00; C08L71/02
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
48 words
A polymer composition usable for the production of articles of biodegradable plastics material, including an ethylene/vinyl alcohol copolymer and a destructured starch, wherein said ethylene/vinyl alcohol copolymer has an ethylene content of from 10 to 90% by weight and a melt flow index of from 2 to 50.
Claim 2
Dependent Claim
48 words
A polymer composition usable for the production of articles of biodegradable plastics material, including an ethylene/vinyl alcohol copolymer and a destructured starch, wherein said ethylene/vinyl alcohol copolymer has an ethylene content of from 10 to 90% by weight and a melt flow index of from 2 to 50.
Claim 3
Dependent Claim
26 words
A polymer composition according to Claim 1, in which the copolymer and the starch are present in a ratio of from 1:19 to 19:1 by weight.
Claim 4
Dependent Claim
26 words
A polymer composition according to Claim 1, in which the copolymer and the starch are present in a ratio of from 1:4 to 4:1 by weight.
Claim 5
Dependent Claim
27 words
A polymer composition according to Claim 1, also including a high-boiling plasticizer at a concentration of from 0.05 to 100% of the weight of the starch component.
Claim 6
Dependent Claim
27 words
A polymer composition according to Claim 4, in which the concentration of the high-boiling plasticizer is from 20% to 100% of the weight of the starch component.
Claim 7
Dependent Claim
32 words
A composition according to Claim 4 or Claim 5, in which the high-boiling plasticizer is selected from the group consisting of glycerine, polyethylene glycol, ethylene glycol, propylene glycol, sorbitol, and mixtures thereof.
Claim 8
Dependent Claim
28 words
A composition according to anyone of Claims 1 to 6, also including a quantity of urea of from 2 to 20% of the weight of the starch component.
Claim 9
Dependent Claim
26 words
A composition according to anyone of Claims 1 to 7, including water at a concentration of up to 6% of the total weight of the composition.
Claim 10
Dependent Claim
38 words
A composition according to anyone of Claims 1 to 8, including a quantity of a polymer selected from modified ethylene copolymers, in particular ethylene/acrylic acid, and mixtures thereof, of up to 15% of the weight of the composition.
Claim 11
Dependent Claim
13 words
A composition according to anyone of Claims 1 to 9, including polyvinyl alcohol.
Claim 12
Dependent Claim
26 words
A composition according to anyone of Claims 1 to 10, also including a quantity of ammonia of up to 0.5% of the weight of the composition.
Claim 13
Dependent Claim
34 words
A composition according to Claims 1 to 11 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
19 words
Articles in the form of films made from a polymer composition according to anyone of Claims 1 to 12.
Claim 15
Dependent Claim
16 words
Moulded articles made from a polymer composition according to any one of Claims 1 to 12.
Claim 16
Independent Claim
103 words
A method for the preparation of a polymer composition usable for the production of articles of biodegradable plastics material, comprising the step of: - mixing an ethylene/vinyl alcohol copolymer and starch in a ratio by weight of from 1:19 to 19:1 with a quantity of a high-boiling plasticizer of from 0.05 to 100% of the weight of the starch, possibly in the presence of a destructuring agent selected from the group consisting of urea, alkaline-earth or alkali metal hydroxides, in an extruder which is heated to a temperature and for a period of time sufficient to bring about the destructuring of the starch.
Claim 17
Independent Claim
103 words
A method for the preparation of a polymer composition usable for the production of articles of biodegradable plastics material, comprising the step of: - mixing an ethylene/vinyl alcohol copolymer and starch in a ratio by weight of from 1:19 to 19:1 with a quantity of a high-boiling plasticizer of from 0.05 to 100% of the weight of the starch, possibly in the presence of a destructuring agent selected from the group consisting of urea, alkaline-earth or alkali metal hydroxides, in an extruder which is heated to a temperature and for a period of time sufficient to bring about the destructuring of the starch.
Claim 18
Dependent Claim
105 words
A method according to Claim 15, comprising the step of mixing, in an extruder heated to a temperature of between 120 and 170°, an ethylene/vinyl alcohol copolymer with a destructured-starch-based component which is prepared beforehand by mixing starch in an extruder with a quantity of a high-boiling plasticizer of from 0.05 to 100% of the weight of the starch, in the presence of a quantity of a destructuring agent selected from the group consisting of urea, alkaline or alkaline-earth hydroxides, and mixtures thereof effective for causing the destructuring of the starch at a temperature below the boiling of the plasticizer and between 120 and 170°C.
Claim 19
Dependent Claim
32 words
A method according to Claim 15 or Claim 16, in which the high-boiling plasticizer is selected from the group consisting of glycerine, polyethylene glycol, ethylene glycol, propylene glycol, sorbitol, and mixtures thereof.
Claim 20
Dependent Claim
78 words
A method according to Claim 15, in which the destructuring agent is added in a quantity of from 2 to 20% of the weight of the starch component, in which the mixing operation is carried out with the addition of a quantity of water of from 0.05 to 100% of the weight of the starch component, and in which the water concentration is reduced to a value no greater than 6% of the weight of the whole composition.
Claim 21
Independent Claim
17 words
A method according to any one of Claims 16 to 18, also including the addition of ammonia.
References Cited (Backward Citations)
US3652542A
Cited
EP0327505A2
Cited
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