Kureha Kagaku Kogyo Kabushiki Kaisha

Yoshiharu Nishimoto

Kengo Yamazaki

Masaki Ohya

Hajime Tsukamoto

Ichiro Kitada

Takashi Sato

Kunio Shibuya

Tooru Oosugi

Hajime Takamoto

Eiichi Hayashi

A flexible multilayer film suitable as a (food-)packaging material includes a first seal layer comprising principally a metallocene-catalyzed polyolefin, and a second seal layer comprising a copolymer of at least one oxygen-containing monomer and ethylene. The copolymer is set to have a crystal melting point lower than that of the metallocene-catalyzed polyolefin. The second seal layer may preferably have a thickness larger than that of the first seal layer. Because of the provision of the second seal layer adjacent to the first seal layer, the multilayer film is provided with an improved film-formability while retaining the good sealability of the metallocene-catalyzed polyolefin.

Multilayer film

Disclosed herein is a biaxially oriented laminated film comprising at least a surface layer of a polyester containing not less than 88 mol. % of terephthalic acid as an acid ingredient, an intermediate layer of a polyamide having a melting point of higher than 160.degree. C. and lower than 210.degree. C. and a heat-sealing layer or a polyolefin, the thickness of the polyester layer being lower than the thickness of the polyamide layer.

Biaxially oriented laminated film

A heat-shrinkable laminated film suitable for a packaging film, having at least two layers of a mixed aliphatic polyamide resin layer (A) of 55 to 90 wt. % of an aliphatic polyamide resin with a crystalline melting point of 175.degree. to 240.degree. C. and 45 to 10 wt % of an aliphatic polyamide resin with a crystalline melting point of from not less than 120.degree. C. to less than 175.degree. C.; and a mixed resin layer (B) of a saponified ethylene-vinyl acetate copolymer as the main constituent. These laminated films have excellent gas barrier properties, stretchability, uniform heat-shrinkability and useful dimensional stability.

Heat-shrinkable laminated film

Disclosed herein is a heat-shrinkable laminated film comprising at least two layers of a mixed resin layer (A) consisting essentially of 65 to 85 wt % of a polyamide resin and 15 to 35 wt % of a saponified ethylene-vinyl acetate copolymer, and a layer (B) containing at least 55 wt % of a saponified ethylene-vinyl acetate copolymer, the thickness of said layer (A) being larger than that of said layer (B).

Heat-shrinkable laminated film and process for producing the same

Disclosed herein is a coextruded, biaxially stretched and laminated heat-shrinkable tubular film, comprising:

Heat-shrinkable laminate tubular film

Disclosed herein is a heat-shrinkable laminate tubular film comprising a gas-barrier layer of a copolymer of vinylidene chloride, outer layers of a polyolefin, at least one intermediate layer of a polyamide or a thermoplastic polyester both of which show a crystal melting point of not more than 240.degree. C. and have a specified thickness, and adhesive layers disposed between any of the above layers.

Disclosed herein are a heat-resistant and oil-resistant laminate film comprising gas-barrier resin layer(s), thermoplastic resin layer(s) different from a gas-barrier resin and adhesive layer(s) disposed between the gas-barrier resin layer and the thermoplastic resin layer, produced by co-extruding a gas-barrier resin, a thermoplastic resin and an adhesive composition and irradiating the co-extruded laminate, the total number of the layers of the laminate film being not less than 3, and the adhesive layer comprising a cross-linked polymer and the adhesive composition consisting essentially of 100 parts by weight of a melt-extrudable adhesive resin and 0.1 to 50 parts by weight of a radiation-sensitive compound, and a process for producing the heat-resistant and oil-resistant laminate film.

Heat-resistant and oil-resistant laminate film and process for preparing

Disclosed herein is a heat-shrinkable laminate film comprising outer layers of a polyolefin, a gas-barrier layer of a copolymer of vinylidene chloride, at least one intermediate layer of an ionomer and adhesive layers disposed between any of the above layers, the total thickness of the intermediate layer(s) of an ionomer being 5 to 20% of the total thickness of the heat-shrinkable laminate film. The heat-shrinkable laminate film is particularly useful in packaging foodstuffs.

Heat-shrinkable laminate film

Disclosed herein is a heat-shrinkable laminate film excellent in gas-barrier property and oil-resistance and heat-sealing resistance, comprising a core layer of a gas-barrier resin which is a copolymer of vinylidene chloride or a copolymer of ethylene and vinyl alcohol, the outer layer (A) of a resin which is a copolymer (I) of ethylene and alpha-olefine having specific gravity of 0.900 to 0.950 and of a crystal melting point of 110.degree. to 130.degree. C. or a mixture of more than 20% by weight of the copolymer (I) and less than 80% by weight of a copolymer (II) of ethylene and vinyl acetate having crystal melting point of 80.degree. to 103.degree. C., the other outer layers (B) of a resin which is a cross-linked material formed from a polymer selected from the group consisting of the copolymer (I), the copolymer (II) and mixture of the copolymer (I) and the copolymer (II) by exposing the polymer to an ionizing irradiation, and two adhesive layers disposed between the core layer and the outer layers (A) and (B).

Disclosed herein is a heat-shrinkable multi-layered laminate film comprising a core layer made of a saponified copolymer of ethylene and vinyl acetate, two outer layers made of a mixture of a copolymer of ethylene and vinyl acetate having a crystal melting point of 85.degree. to 103.degree. C. and a copolymer of propylene and ethylene having a crystal melting point of 126.degree. to 155.degree. C. or a linear low-density polyethylene having a crystal melting point of 110.degree. to 125.degree. C. and two adhesive layers disposed between the core layer and the two outer layers, the multi-layered laminate film being excellent in gas-barrier property, oil resistance and peel-resistance of the sealed parts in the heat shrinkage and suitable for heat-shrinking packaging of foodstuffs, particularly for vacuum heat-packaging of foodstuffs.

Heat shrinkable multi-layered laminate film

Described is a laminate film excellent in oil-resistance, heat-resistant sealing ability, peel resistance and gas-barriering property having a percentage of heat-shrinkage of larger than 15% at 90.degree. C. comprising a center layer consisting of a copolymer(I) of vinylidene chloride and both two outermost layers consisting of a mixture of 20 to 70% by weight of a copolymer(II) of ethylene and alpha-olefin of density of 0.900 to 0.950 and of crystalline melting point of 110.degree. to 125.degree. C. and 80 to 30% by weight of a copolymer(III) of ethylene and vinyl acetate with the proviso that the content of the copolymer(II) in the total amount of copolymers in both the two outermost layers is less than 65% by weight and showing a structure of having an adhesive layer between the center layer and the outermost layer.

Laminate film having a heat-shrinkage rate greater than 15 percent at

A heat-shrinkable multilayer laminate film possessing excellent heat resistance, oil resistance and gas-barrier properties is obtained by interposing one intermediate layer of a thermoplastic resin having a crystalline melting point of from 70.degree. to 100.degree. C. between a core layer of a vinylidene chloride copolymer and outer surface layers of an ethylene/.alpha.-olefin copolymer having a crystalline melting point of not lower than 110.degree. C. or a mixture of this ethylene/.alpha.-olefin copolymer and an .alpha.-olefin polymer having a crystalline melting point of from 80.degree. to 100.degree. C. The thus obtained laminate film can be in sheet or tubular form, and is suitable for use in packaging by heat shrinkage raw meat, processed meat, cheese and other fat-containing food. This heat-shrinkable laminate film is produced by biaxially stretching the starting laminate film at a specific temperature determined by the crystalline melting points of the resins of the intermediate layer and the outer surface layers.

A method of molding a tubular laminate comprising joining flows of a plurality of thermoplasticized resins together to prepare a laminated composite flow having two side edges, and then passing the composite flow having two side edges through an annular extrusion die to abut both side edges of the respective layers to each other in the die, thereby forming an integrated tubular flow.

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Iwaki, Japan

Yoshiharu Nishimoto