A heat-resistant polyester container wherein the temperature T is not
lower than 120.degree. C. at a moment when the rate of contraction in the
barrel portion of the polyester container represented by the following
formula is 0.66%,
Ratio of contraction (%)=(amount of contraction/gauge length).times.100
(1)
wherein the amount of contraction is measured from a test piece cut from
the barrel portion of the polyester container so as to possess a gauge
length of 20 mm in compliance with TMA without pre-loading while
elevating the temperature at a rate of 3.degree. C./min after 30.degree.
C. is exceeded.
The polyester container exhibits excellent heat resistance, and enables
the retort-sterilization to be executed after the food or beverage has
been filled and sealed without permitting the barrel portion of the
container to be deformed.
