Gas-barrier, multi-layer hollow container
AssigneeKureha Kagaku Kogyo Kabushiki Kaisha
InventorsZenya Shiiki, Yukichika Kawakami, Nobuo Sato, Mitsuru Hoshino, Toshitaka Kouyama
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Abstract
The invention relates a gas barrier multi-layer hollow container having a multi-layer wall structure that a thermoplastic resin layer is laminated on at least one side of a layer formed from polyglycolic acid containing at least 60 wt. % of a repeating unit represented by the following formula (1): wherein the container has excellent oxygen gas barrier property and/or carbon dioxide gas barrier property, and a production process thereof.
Claims17
A gas barrier multi-layer hollow container having a multi-layer wall structure comprising a thermoplastic resin layer laminated on at least one side of a layer formed from polyglycolic acid containing at least 60 wt. % of a repeating unit represented by the following formula (1):
- and having a melt viscosity, η*, of 500 to 100,000 Pa·s as measured at a temperature of the melting point of the polymer+20° C. and a shear rate of 100/sec, a melting point, Tm, of at least 150° C., and a melt enthalpy, ΔHm, of at least 20 J/g,
- wherein said container is a blow-molded and uniaxially or biaxially stretched product.
A process for producing a multi-layer hollow container, which comprises respectively heating and melting polyglycolic acid containing at least 60 wt. % of a repeating unit represented by the following formula (1):
- at least one thermoplastic resin, and an adhesive in extruders, causing the respective resins to flow into a die for forming a multi-layer tubular parison, holding the parison by a split mold before it is solidified, pinching off one end of the parison, and at the same time blowing up the parison to the mold wall by introducing air into the parison, and then cooling the blown parison, thereby molding the container.
A process for producing a multi-layer hollow container, which comprises co-injecting polyglycolic acid containing at least 60 wt. % of a repeating unit represented by the following formula (1):
- and having a melt viscosity, η*, of 500 to 100,000 Pa·s as measured at a temperature of the melting point of the polymer+20° C. and a shear rate of 100/sec, a melting point, Tm, of at least 150° C., and a melt enthalpy, ΔHm, of at least 20 J/g, at least one thermoplastic resin, and optionally an adhesive into a closed-end parison, blowing up the parison to the mold wall by introducing air into the parison in the mold after solidifying the parison once, or in a supercooled state or at a temperature not higher than the melting point, Tm, but not lower than the glass transition point, Tg, of the parison without solidifying it, while stretching the parison in a longitudinal direction and cooling the blown parison, thereby molding the container.
A gas barrier multi-layer hollow container having a multi-layer wall structure comprising a thermoplastic resin layer laminated on each side of a layer formed from polyglycolic acid containing at least 60 wt. % of a repeating unit represented by the following formula (1):
- wherein an adhesive layer is provided between the polyglycolic acid layer and each thermoplastic layer, and wherein the container is a blow-molded product.
Dependencies are inferred from the claim text.