Laminar articles from a polyolefin matrix, ethylene-vinyl alcohol copolymers and a compatibilizer
AssigneeE. I. Du Pont de Nemours and Company
InventorsJose M. Torradas, Robert W. Scott
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Abstract
The laminar article of the invention comprises a mixture of a polyolefin matrix with a barrier resin of polyethylene-vinyl alcohol copolymer and a compatibilizer selected from an ethylene-ethylenically unsaturated carboxylic acid copolymer such as ethylene methacrylic acid or ethylene acrylic acid, ethylene vinyl acetate, polyethylene vinyl alcohol or mixtures thereof. A process is also claimed for preparing a laminar article with multiple thin, overlapping layers, comprising preparing a melted heterogeneous blend of a polyolefin, an ethylene-vinyl alcohol copolymer, and the above compatibilizer; extending the body of the melt; and cooling the extended body to below the melting point of the polyolefin.
Claims15
A process for manufacturing a laminar, shaped article of polymeric materials comprising the steps of:
- (a) establishing a melted, heterogeneous blend of
- (i) polyolefin (component (i)),
- (ii) a polyethylene-vinyl alcohol polymer (component (ii)) containing about 20-60 mole % of ethylene units and having a melting point at least about 5.degree. C. higher than the polyolefin, and
- (iii) a compatibilizer chosen from the list consisting of an ethylene-.alpha.,.beta.-ethylenically unsaturated carboxylic acid copolymer, polyethylene-vinyl acetate, a polyethylene vinyl alcohol polymer having a melting point which is less than the melting point of the polyethylene-vinyl alcohol polymer component (ii), and mixtures thereof;
- (b) extending a body of the melt;
- and
- (c) cooling the extended body to below the melting point of the polyolefin, so as to provide a laminar shaped article wherein the polyethylene-vinyl alcohol polymer component (ii) is present in the article as thin, substantially parallel, overlapping layers of material.
A laminar article comprising:
- (a) a polyolefin (component (a));
- (b) an polyethylene-vinyl alcohol polymer (component (b)) containing about 20-60 mole % ethylene units and having a melting point at least about 5.degree. C. higher than the polyolefin;
- and
- (c) a compatibilizer (component (c)) chosen from the list consisting of an ethylene-.alpha.,.beta.-ethylenically unsaturated carboxylic acid copolymer, polyethylene-vinyl acetate, polyethylene-vinyl alcohol polymer having a melting point which is less than the melting point of the polyethylene-vinyl alcohol polymer component (b), and mixtures thereof, wherein the polyethylene-vinyl alcohol polymer component (b) is present in the article as thin, substantially parallel, overlapping layers of material.
Dependencies are inferred from the claim text.