| 摘要 |
A technical problem to be solved by this invention is to create a bottom wall structure that enables the bottom to perform a satisfactory vacuum absorbing function when the bottom plate is allowed to draw upward smoothly with the progress of pressure reduction. This problem is achieved by a biaxially stretched, blow molded synthetic resin bottle with a bottom (5) comprising a sunken bottom portion (11), which deforms as it draws upward in a direction of bottle inside and which comprises a ring groove (15) formed by being successively connected to an inner peripheral edge of a ground contact portion (16) disposed at the foot of an outer peripheral wall of the bottom (5), a central concave portion (12) disposed at a center of the bottom (5), and a flat ring portion (13) disposed between an inner peripheral edge of the ring groove (15) and the central concave portion (12), wherein the sunken bottom portion (11) is characterized by comprising a plurality of short slim ribs (14) disposed at several points of the flat ring portion (13). |
