Container having a bottom with a corrugated internal seat portion

Container of plastic material, comprising a body and a bottom, the bottom having an annular outer seat defining a principal seating plane for the container, and a deformable membrane that extends radially inside the annular outer seat and is arranged to be able to adopt two configurations:

• a retracted configuration, in which the membrane extends axially above the principal seating plane;
• a deployed configuration, in which the membrane comprises an annular inner seat in the form of an annular bead projecting towards the exterior of the container, which extends axially beneath the principal seating plane and defines a secondary seating plane, and
• the bottom comprises a series of hollow reserves in the annular inner seat, the reserves extending radially astride the annular inner seat, which form local discontinuities of the secondary seating plane, the secondary seating plane being formed from a discrete series of sections of coplanar arcs at the end of the inner seat, which extend between the hollow reserves;
• and wherein the reserves have a central zone and connection fillets with adjacent sections of coplanar arcs, the central zone having a double curvature, a first curvature, viewed from the side, with concavity oriented downwards, a second curvature in radial cross section, with concavity oriented upwards.