| 摘要 |
PROBLEM TO BE SOLVED: To provide a container formed by draw and blow molding made of propylene polymer wherein defect of drawing blow-molded container of propylene polymer produced by cold parison process is cleared and impact resistance is remarkably improved, and a method for its manufacture. SOLUTION: Relating to a container 21 formed by drawn blow molding of a bottomed preform which consists of a propylene polymer and having a neck part which is virtually not yet drawn, and a barrel part 24 and a bottom part 25 which are both drawn, a difference (d) in birefringence between the inner surface and the outer surface of the barrel part 24, defined by an equation d=|Δ0 -ΔI|(provided thatΔ0 =NZ0 -NX0 andΔI=NZI-NXI and in which NZ0 is a refractive index in the direction of height at the outer surface of the barrel part, NX0 is a refractive index in the direction of thickness at the outer surface of the barrel part, NZI is a refractive index in the direction of height at the inner surface of the barrel part, and NXI is a refractive index in the direction of thickness at the inner surface of the barrel part) should be 0.0025 or less in terms of absolute value.
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