Toyo Seikan Kaisha, Ltd.

Toru Suzuki

Sadao Hirata

Akira Kishimoto

Shunsaku Hirata

Muneki Yamada

Jinichi Yazaki

Fumio Kano

Yoshitsugu Maruhashi

Kozaburo Sakano

Syunsaku Hirata

Shinichi Miyazaki

Shigezo Nohara

A molded container having a wall composed of a thermoplastic resin oriented in at least one direction on the wall face, wherein the container wall has a layer of a blend composed mainly of a plurality of melt-extrudable thermoplastic resins, each of which has a solubility parameter (Sp) of at least 9.5, at least one of said thermoplastic resins has an oxygen permeability lower than 5.times.10.sup.-11 cc.multidot.cm/cm.sup.2 .multidot.sec.multidot.cmHg, said thermoplastic resins are chosen so that the difference (.DELTA.Sp) of the solubility parameter in said thermoplastic resins is not greater than 4.5, the elongation of said resin blend is higher than the arithmetic mean (.epsilon.) of elongations of the respective thermoplastic resins, and wherein the container has a thermal shrinkability (.delta.) of at least 5% in the orientation direction of said container wall.

Molded container having wall composed of oriented resin blend

A transparent multi-layer container comprising a co-extrudate of an oxygen-barrier resin layer and an orienting resin layer which is monoaxially or biaxially oriented is disclosed. An adhesive resin layer is preferably interposed between the oxygen-barrier layer and the orienting resin layer, and this co-extrudate is drawn and molded at a specific temperature determined relatively to the melting points and softening points of the respective resins. This container is excellent in the combination of transparency, rigidity, mechanical strength, gas-barrier property and interlaminar peel strength.

Process for making a container

Multilayer container

A packaging material having an improved gas permeation resistance, which comprises at least one layer composed of (A) an ethylene-vinyl alcohol copolymer having a vinyl alcohol content of 50 to 75 mole % and a residual vinyl ester content of up to 4 mole % based on the sum of the vinyl alcohol and vinyl ester or (B) a blend of said ethylene-vinyl alcohol copolymer with up to 150% by weight, based on said copolymer, of at least one thermoplastic polymer other than said copolymer, said ethylenevinyl alcohol copolymer having a main endothermic peak satisfying substantially the following requirement:

Packaging materials having excellent gas permeation resistance and

In a multi-layer blow molded container having a joint portion at least in the bottom portion thereof, barrier characteristics to gases such as oxygen and water vapor and liquids such as water, solvents, aqueous ammonia and salt water and interlaminar strength characteristics such as interlaminar adhesion strength, peel strength and impact strength in the content-filled state can be highly improved by blow molding a parison of a laminate structure of two or more polymer layers in which the polymer composition is different with respect to the thickness direction of the container wall but substantially identical with respect to the plane direction and each of the polymer layers is continuous with respect to the plane direction, in such a manner that a tapered projection protruding outwardly in the thickness direction of the container wall is formed in the joint portion so that each of the polymer layers is substantially continuous in this joint portion. This improved container can easily be prepared according to the customary blow molding technique by using a pair of split molds having such a configuration that a tapered concave groove is formed in the section pinching off the parison when the molds are registered with each other.

Multi-layer blow molded container and process for preparation thereof

A resin laminate structure comprising a layer of a polyolefin and a layer of an ethylene-vinyl acetate copolymer saponified product having an ethylene content of 25 to 50 mole % and a degree of saponification of at least 96 %, wherein a thermoplastic polymer having a carbonyl group in the main chain or side chain thereof is incorporated in at least one of said two layers in an amount of 5 to 100 parts by weight per 100 parts by weight of said polyolefin or said ethylene-vinyl acetate copolymer saponified product.

Resinious laminates having improved gas permeation and delamination

A resin laminate structure comprising a layer of a polymer selected from the group consisting of polyolefins and saponified products of ethylene-vinyl acetate copolymers and a layer of a blend comprising (A) a polyolefin and (B) a saponified product of an ethylene-vinyl acetate copolymer having an ethylene content of 25 to 50 mole % and a degree of saponification of at least 96% at an A:B mixing weight ratio ranging from 98:2 to 2:98, said two layers being laminated so that they are adjacent to each other.

Growing community of inventors

Yokosuka, Japan

Toru Suzuki