American National Can Company

Other

Frank T Bauer

Roger P Genske

Yong J Kim

Robert J Blemberg

John P Eckstein

Mark E Nordness

David M Banik

Grant A Gustafson

Compositions of matter, sheet material, and packages made therefrom. Novel compositions of polypropylene and high density polyethylene are useful as sealant materials for flexible sheet material structures wherein the sheet material is sealable to a preformed container, to form a lid therefor, and is peelable therefrom, with cohesive failure of the sealant layer in the area of the formed seal. The novel sealant layer compositions provided for package closure and sealing which is capable of withstanding retort conditions while maintaining the integrity of the package closure and seal. Concurrently the lid is readily peeled from the package to provide access to the interior of the package. The peelability comprises cohesive failure of the sealant material in a novel blend of a polypropylene polymer with an ethylene polymer having a density of at least 0.940. The novel sealant materials of the invention can be used on a variety of multiple layer sheet material substructures, and particularly those providing barrier properties to food type packaging: especially barrier to the transmission of oxygen and moisture. Typical barrier materials are metal foil, vinylidene chloride copolymer, vinyl alcohol copolymer, olefin polymers and copolymers, and combinations of the above materials.

Peelable packaging and sheet materials and compositions for use therein

A multiple layer sheet material comprising a first layer 12 of vinylidene chloride copolymer having a first softening temperature. A second polymeric sealant layer 14 has a second softening temperature no more than about 50.degree. C. less than the first softening temperature. An optional third layer 16 between the first and second layers has a third softening temperature greater than either of the first and second softening temperatures and comprises a polyethylene terephthalate composition. A fourth polymeric layer 18 has a fourth softening temperature greater than the first and second softening temperatures. The first layer is positioned between the third and fourth layers. A fifth impact layer 20 is positioned between layers 14 and 16. The composition of the impact layer 20 comprises, as a first component, a base polymer drawn from the same family of polymers as a major polymeric component of the second sealant layer, and, as a second component, a polymeric composition providing elastomeric properties to the impact layer and increased shock tolerance to the multiple layer sheet material. The disclosure also teaches the use of the sheet materials in fabrication of packages and teaches methods of fabricating both the sheet materials and the packages.

Multiple layer packaging sheet material

Packaging sheet materials 10 and packages having improved impact/shock tolerance as measured in a slope drop test. The sheet materials comprise an impact layer 12 of a blend of polypropylene and a polymer providing elastomeric properties between a sealant substructure 14 and a substrate substructure 16.

Vinylidene chloride methyl acrylate copolymer coextruded with second and third different polymeric compositions in fabrication of multiple layer films. The third layer is between the first and second layers. The second composition can have a melting temperature greater than 204.degree. C., and can be, for example, polyester, polyamide, or polycarbonate. Preferred films contain at least five layers, at least one of which has a typical extrusion processing temperature higher than the typical extrusion processing temperature of the VDC-MA. Methods of fabricating such films are also disclosed.

Coextruded film and methods comprising vinylidene chloride methyl

Compositions of matter, sheet material, and packages made therefrom. Novel compositions of polypropylene and high density polethylene are useful as sealant materials for flexible sheet material structures wherein the sheet material is sealable to a preformed container, to form a lid therefor, and is peelable therefrom, with cohesive failure of the sealant layer in the area of the formed seal. The novel sealant layer compositions provide for package closure and sealing which is capable of withstanding retort conditions while maintaining the integrity of the package closure and seal. Concurrently the lid is readily peeled from the package to provide access to the interior of the package. The peelability comprises cohesive failure of the sealant material in a novel blend of a polypropylene polymer with an ethylene polymer having a density of at least 0.940. The novel sealant materials of the invention can be used on a variety of multiple layer sheet material substructures, and particularly those providing barrier properties to food type packaging; especially barrier to the transmission of oxygen and moisture. Typical barrier materials are metal foil, vinylidene chloride copolymer, vinyl alcohol copolymer, olefin polymers and copolymers, and combinations of the above materials.

Growing community of inventors

Appleton, WI, United States of America

Frank T Bauer