Method for preparing polar thermoplastic resin compositions having improved gas barrier properties
AssigneeContinental Can Company, Inc.
InventorIhab M. Hekal
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Abstract
A method of preparing a polar thermoplastic resin having improved resistance to gas permeability is disclosed wherein a blend of the resin and coarse mica flakes having an average particle size of less than about 100 mesh is prepared, the blend being prepared under mixing conditions which impart a shear force to the mica flakes sufficient to delaminate the flakes into individual platelets, substantially increasing the original aspect ratio of the flakes whereby an increase in the gas barrier properties of the resin is attained greater than that attained with fine mica flakes having an average particle size greater than about 100 mesh.
Claims27
A method of preparing a polar thermoplastic resin having increased resistance to gas permeability which comprises providing a blend of the resin and mica flakes having a plurality of platelets, the flakes having a particle size less than about 100 mesh before blending and then admixing the mica flakes and resin at a temperature at which the resin is molten, the admixing imparting a shear force which effects delamination of the mica platelets and a substantial increase in the aspect ratio whereby improved gas barrier and heat stability properties are achieved.
The composition of 14 wherein the polyepoxide is the condensate of Bisphenol A and epichlorohydrin.
A method of forming a thermoplastic container having increased gas barrier and heat stability properties and adapted to be used for the packaging of foodstuffs highly susceptible to oxidative deterioration which comprises providing a blend of a polar thermoplastic resin and mica flakes having a plurality of platelets, the flakes having an average particle size less than about 100 mesh, admixing the mica flakes and polar thermoplastic resin at a temperature at which the resin is molten, the admixing imparting a shear force which effects delamination of the mica platelets to effect a substantial increase in the aspect ratio of the flakes with a concommitant increase in the gas barrier properties of the resin, and then molding the admixture into a container.
Dependencies are inferred from the claim text.