Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
81 words
A method for the preparation of a destructured-starch-based composition usable for the production of articles of biodegradable plastics material, including the step of mixing starch as it is, in a heated extruder, with a high-boiling plasticizer and a destructuring agent selected from the group consisting of urea, alkaline and alkaline-earth hydroxides, and mixtures thereof for a time sufficient to bring about destructuring of the starch and at a temperature below the boiling point of the plasticizer and between 120 and 170°C.
Claim 2
Independent Claim
81 words
A method for the preparation of a destructured-starch-based composition usable for the production of articles of biodegradable plastics material, including the step of mixing starch as it is, in a heated extruder, with a high-boiling plasticizer and a destructuring agent selected from the group consisting of urea, alkaline and alkaline-earth hydroxides, and mixtures thereof for a time sufficient to bring about destructuring of the starch and at a temperature below the boiling point of the plasticizer and between 120 and 170°C.
Claim 3
Dependent Claim
28 words
A method according to Claim 1, in which the plasticizer is selected from the group consisting of glycerine, polyethylene glycol, ethylene glycol, propylene glycol, sorbitol, and mixtures thereof.
Claim 4
Dependent Claim
30 words
A method according to Claim 1 or Claim 2, in which the quantity of plasticizer added to the starch is from 0.05 to 100% of the weight of the starch.
Claim 5
Independent Claim
32 words
A method according to any one of Claims 1 to 3, in which the quantity of plasticizer added to the starch is from 20 to 100% of the weight of the starch.
Claim 6
Independent Claim
44 words
A method according to any one of Claims 1 to 4, in which the mixing operation is carried out with the addition of a quantity of an ethylene/acrylic acid and/or polyvinyl alcohol copolymer of up to 15% of the total weight of the mixture.
Claim 7
Independent Claim
31 words
A method according to any one of the preceding claims, in which the starch used is a natural starch which is not dried beforehand and to which water is not added.
Claim 8
Independent Claim
34 words
A method according to any one of the preceding claims, in which the destructuring agent is constituted by urea added in a proportion of from 2 to 20% of the weight of the starch.
Claim 9
Independent Claim
20 words
A method according to any one of the preceding claims, in which the destructuring agent is constituted by sodium hydroxide.
Claim 10
Dependent Claim
22 words
A method according to Claim 5, in which the mixing of the starch is carried out with the addition of ammonium hydroxide.
Claim 11
Independent Claim
45 words
A method according to any one of the preceding claims, including the addition to the starch of additives selected from the group consisting of UV stabilisers, flameproofing agents, cross-linking agents, fungicides, herbicides, antioxidants, fertilisers, opacifiers, and stabilisers which do not interfere with the destructuring process.
Claim 12
Dependent Claim
16 words
A destructured-starch-based composition obtainable by a method according to any one of Claims 1 to 10.