US 6,011,092 A · Thermoplasticized starch component and process for the preparation thereof

Abstract

The invention relates to a process for thermoplasticizing starch, a melt-processible polymer composition, which contains a starch-based component and a thermoplastisized polymer component, and a method for preparating such a composition. According to the invention the starch component, which contains hydroxyl groups capable of reacting with isocyanate groups, is modified so that it can be dissolved or gelatinized/plastisized in the melt of a hydroxy acid polymer. The starch component is then reacted with a thermoplastic component formed by a hydroxy acid polymer, in particular a lactic acid polymer, in order to produce a melt-processible, biologically degradable starch-based polymer, which can be used as an adhesive and for coating of paper and cardboard products and for preparation of injection moulded and thermoformed articles.

Claims45

Dependent claims

A process for plastisizing starch, comprising

bringing the starch into a such a modified form that it contains at least some free hydroxyl groups and it is soluble in a hydroxyacid polymer melt,
reacting the thus modified starch with a thermoplastic component consisting of an isocyanate-terminated hydroxyacid polymer at 140-200.degree. C., and
continuing the reaction until an at least essentially homogeneous mixture is obtained and the thermoplastic component is at least partially bound to the starch component by means of urethane bonds.

Dependencies are inferred from the claim text.

Thermoplasticized starch component and process for the preparation thereof

Life of this patent

Thermoplasticized starch component and process for the preparation thereof

Life of this patent

Abstract

Claims45