Idemitsu Petrochemical Co., Ltd.

Toyokazu Yamada

Takeshi Shinohara

Hiroshi Odaka

Hiroyuki Takahashi

Masao Miyama

Hiroshi Maeda

Hideo Sugimura

Masahiro Akamatsu

A multilayer composite and an easily openable container produced by using the multilayer composite are provided. The multilayer composite comprises a surface layer of a polyolefin resin, an intermediate layer of a mixture of a polystyrenic resin with a thermoplastic elastomer or with a thermoplastic elastomer and a polyolefin resin, and a base layer of a polystyrenic resin, and the peeling strength between the intermediate layer and the base layer is larger than the peeling strength between the surface layer and the intermediate layer. The easily openable container produced by using the multilayer composite is capable of being sealed with a lid strongly while maintaining easy openability because the opening of the sealed container is performed utilizing the peeling between the surface layer and the intermediate layer.

Multilayer composites and easily openable containers

A method for recovering and reusing a scrap multilayer plastic sheet or film comprising at least a base material layer and laminated with an adhesive resin comprising at least one of an ethylene-vinyl acetate copolymer, a styrene-isoprene copolymer, a styrene-butadiene copolymer, a styrene-methyl methacrylate copolymer and an ethylene-acrylic acid ester-maleic anhydride copolymer. The method comprises heating the scrap multilayer sheet or film to a temperature lower than the softening point of the base material layer to make the interlaminar peeling strength of the adhesive resin lower than the strength at break of a layer having the lowest strength at break, except for the adhesive layer, and separating the multilayer scrap into at least two scrap layers and recovering at least one scrap layer in sheet or film form. The present invention provides effective reuse of scrap with almost no reduction in physical properties. Furthermore the cost of the production or molding of the sheet can be reduced. Still further, it is not necessary to add an additive, a white pigment and the like for preventing thermal deterioration. When polypropylene is used as a base material in the present method, it is not necessary to use low viscosity polypropylene as is conventionally required. That is, since high viscosity polypropylene can be used, vacuum molding becomes easy and furthermore a multilayer sheet or film having desirable physical properties can be produced very economically.

Method for recovering scraps of multi-layer plastic sheet or film

A multilayer container with a flange for sealing with a lid, wherein the thickness of the inner surface layer at the inner edge of the flange is thinner than that in the sealing area, is produced by a method wherein a circular portion of a multilayer sheet to be the flange is held at a certain pressure while the multilayer sheet is being thermoformed under specified molding conditions, with the other portion than the circular portion being stretched. Even a seal ring having an even surface serves as a means for sealing the resulting multilayer container with a lid while ensuring easy openability.

Method of producing an easily openable multilayer plastic container

Multilayer plastics containers and methods of producing the same

A multilayer structure comprising (C) a substrate layer, (A) a surface layer of a thermoplastic resin, and (B) an intermediate layer of a thermoplastic resin sandwiched between the (C) substrate layer and the (A) surface layer, wherein the (B) intermediate layer contains 0 to 70% by weight of a flake inorganic filler, the peeling strength between the (A) surface layer and the (B) intermediate layer is from 0.3 to 2.0 kg/15 mm, and the peeling strength between the (B) intermediate layer and the (C) substrate layer is at least 1.2 times as large as the peeling strength between the (A) surface layer and the (B) intermediate layer. When a packaging container is produced by forming the multilayer structure into a container body and sealing the container body with a lid, easy openability and high sealing property will be ensured because the opening of the packaging container is not operated by using the delamination between the sealed portion but by using the easy delamination between the surface layer (A) and the intermediate layer (B). The use of the multilayer structure for production of packages is economically advantageous because the recovered scrap can be reused as the material for the substrate layer (C) without affecting the peelability of the surface layer (A).

Multilayer structure and easily openable container and lid

A laminated material is prepared in which a resin composition layer (A) containing a thermoplastic resin and an inorganic filler in a scaly or non-scaly form in an amount from 20% to 80% by weight of the total weight of the thermoplastic resin and the filler interposes a resin composition layer (B) containing a thermoplastic resin and an inorganic filler in an amount from 30% to 70% by weight of the weight of the inorganic filler contained in the resin composition layer (A), the filler being in a scally form when the filler in the layer (A) is in a scaly form or being in a non-scaly form when the filler in the layer (A) is in a non-scaly form with a thermoplastic resin layer. For the laminated material in which the scaly inorganic filler is contained in the layer (A), the layer (B) containing the thermoplastic resin and the non-scaly inorganic filler in the amount of 20% to 80% by weight of the total weight of the thermoplastic resin and the non-scaly filler is interposed between the layer (A) containing the thermoplastic resin and the scaly inorganic filler in the amount of 20% to 80% by weight of the total weight of the thermoplastic resin and the scaly inorganic filler and the thermoplastic resin (C).

Laminated materials and laminated articles

A method of manufacturing a multi-layer resin material by employing a plurality of kinds of thermoplastic resin. Resins for inner and outer layers are supplied into a feed block of a feed block type T-die coextrusion apparatus where they are laid up another, and are then sent to the T-die side. In this case, a resin which is practically similar to the resin for the outer layer is supplied as an auxiliary resin to both lateral edges of the multi-layer resins within the feed block. Thus, the sheet extruded from the T-die slit has lateral edges which are made of a single resin.

Method of manufacturing multi-layer resin material

A resin laminate is disclosed, which comprises a gas permeation-resistant resin layer having laminated on each side thereof a polyolefin based resin layer, wherein said polyolefin based resin layer contains an inorganic filler in an amount of 30 to 80% by weight based on the total weight of the resin composition. The resin laminate may be provided with a thermoplastic resin layer containing no inorganic filler on the outersurface thereof. The resin laminate has a minimized oxygen gas permeability and has a low calorific value and is useful as a packaging material.

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Himeji, Japan

Toyokazu Yamada