Abstract: A five-layered container formed by biaxial orientation blow molding of an injection-molded, five layered-structured parison, wherein central, innermost and outermost layers comprise a resin A, two intermediate layers between the innermost layer and the central layer and between the outermost layer and the central layer comprise a resin B, the resin A comprises a polyester resin containing ethylene terephthalate as a main recurring unit, and the resin B comprises a mixture of a polyester resin containing ethylene terephthalate as a main recurring unit with polyarylate or a resin produced by an ester-exchange reaction of said polyester resin with polyarylate, and a m-xylene group-containing polyamide resin.

Abstract: A parison, as a precursor of a container, composed at least of a thermoplastic resin (resin A) and another thermoplastic resin having excellent gas-barrier property (resin B) and containing a multilayered resin layer at least in an intermediate layer between an outermost layer and an innermost layer each composed of resin A at parts other than the open end part of the mouth portion of the parison, or wholly in the parison, said multilayered resin layer being formed by using an injection-molding machine equipped with a static mixing-stirring device provided in a nozzle portion of an injection cylinder, or in a mold, or in a resin flow passage between the nozzle portion and a mold, and injecting the resins A and B through the static mixing-stirring device so that flows of the resins A and B are divided in a plurality of thin layers parallel to the flowing direction; and a process for production thereof.

Abstract: A biaxially oriented blow-molded container composed of a thermoplastic gas-barrier resin (resin B) and a thermoplastic resin (resin A) other than resin B and having excellent gas-barrier property and delamination strength. The container comprises a substantially non-oriented mouth portion composed of resin A, a portion composed of two layers of resin A and one layer of resin B which are laminated with the resin A layer and the resin B layer occurring alternately and a portion composed of three layers of resin A and two layers of resin B which are laminated with the resin A layer and the resin B layer occurring alternately. A portion having a small radius of curvature where delamination tends to occur is formed in a three-layer structure. A process for producing the container is also provided.

Abstract: A biaxially oriented multilayered container consisting of a body portion and a mouth portion. The body portion comprises one or more layers of a thermoplastic gas-barrier resin B and layers of a thermoplastic resin A other than the resin B which are larger in number than the resin B layers by 1, the resin A and B layers being laminated alternately, and at least the open end part of said mouth portion is composed of a single layer of the resin A. As a characteristic feature, a coarsely mixed resin layer of resins A and B in which the proportion of resin particles having a long diameter of not more than 10 .mu.m is not more than 10% exists in at least one of the boundaries between the resin A and B layers.