Patent ID: 8124204

Claim:
A multilayer bottle produced by biaxial stretch blow molding of a multilayer preform produced by injection of two resins respectively into a cavity of a mold, comprising a barrel portion including an outermost layer, an innermost layer and at least one barrier layer interposed between the outermost layer and the innermost layer, wherein the outermost layer and the innermost layer are each made mainly of a thermoplastic polyester resin obtained by polymerizing a dicarboxylic acid component containing 80 mol % or more of terephthalic acid with a diol component containing 80 mol % or more of ethylene glycol; and the multilayer bottle satisfies the requirements represented by the following formulae (1) to (3) at the same time: OTR≦0.2 cc·mm/(m 2 ·day·atm) (1) where OTR represents an average oxygen transmission rate of the barrier layer of the barrel portion as measured at a temperature of 23° C. and a relative humidity of 60%; 20≦(Average degree of orientation of barrier layer of barrel portion)≦45 (2) where the degree of orientation represents a value calculated from refractive indices of the barrier layer as measured at 23° C. using an Abbe refractometer according to the following formula: Degree of orientation=[{ n ( x )+ n ( y )}/2 −n ( z )]×1000 where n(x) represents a refractive index of the barrier layer in a height direction of the bottle; n(y) represents a refractive index of the barrier layer in a circumferential direction of the bottle; and n(z) represents a refractive index of the barrier layer in a thickness direction thereof; and 0 ≦b/a ×100≦200 (3) where “a” represents an average thickness (μm) of the barrier layer of the barrel portion; and “b” represents an average thickness (μm) of the barrier layer of a bottom portion of the bottle, wherein, in the above respective formulae, the bottom portion is defined as a portion extending from a ground portion of the bottle to a position corresponding to 20% of a height between the ground portion and an opening portion of the bottle; the barrel portion is defined as a portion except for the ground portion which has an outer diameter corresponding to 80% or more of a maximum outer diameter of the ground portion; and the ground portion is defined as a portion contacting with a floor when the bottle is vertically placed thereon.