US 5,316,847 AGranted

Biologically degradable films comprising enzyme-coated bio-degradable polymer particles

AssigneeBiodata S.p.A.

InventorHannu L. Suominen

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Abstract

A biologically degradable film is prepared consisting of a synthetic polymer and a biologically degradable polymer. The biologically degradable polymer is divided into small particles in an aqueous suspension by means of enzymes that split and release small molecules from the surface of the biopolymer particles. After achieving desired particle size, an emulsion is formed with vegetable oil and the particles coated with enzyme protein become coated with vegetable oil, which at the same time interrupts the degradation of the biopolymer particles by the enzyme. The coated particles with the oil are separated from the suspension to remove small molecules after which the particles are re-dried and then pulverized. The final film is prepared in a film extruder in which the biopolymer is mixed with the synthetic polymer and possibly other additives that are generally used in forming polymer films.

Claims10

Dependent claims

Biologically degradable film composed of

a synthetic polymer and
biologically degradable polymer particles having a particle size smaller than about 10 .mu.m, said biologically degradable polymer particles being homogeneously distributed in said synthetic polymer,
said particles of said biologically degradable polymer being coated with enzymes in an amount effective to degrade said biologically degradable polymer when said enzyme is exposed to moisture, said particles being further coated with an oxidizable outer coating comprising vegetable-based oil, said oil coating being present in an effective amount to prevent moisture from contacting said enzymes and thereby temporarily preventing the degradation of said biologically degradable polymer by said enzymes after said biologically degradable polymer particles have attained a particle size smaller than about 10 .mu.m, said oil coating when oxidized allowing moisture to contact said enzymes and thereby degrade said biologically degradable polymer.

Dependencies are inferred from the claim text.

Facts

Application: 07/998,913Filed 30 Dec 1992 · continuation
Priority: FI 8947345 Oct 1989
Granted: 31 May 1994
Term ends: Not estimatedThe source records don’t support an estimate.

Classification19 codes

A01G 13/33
Mats; Nets; Sheets or films: sheets or films
C08J 5/18
Manufacture of articles or shaped materials containing macromolecular substances: manufacture of films or sheets
C08L 23/04
Not modified by chemical after-treatment: homopolymers or copolymers of ethene
C08L 101/00
Compositions of unspecified macromolecular compounds