Synthetic resin container

Abstract

A synthetic resin container includes a bottom part having a bottom plate part present at the center of the bottom part and a peripheral part positioned at the periphery of the bottom plate part. The peripheral part includes a grounding part having an inside slope rising outwardly of the container with the outer peripheral edge of the bottom plate part being a start point, and an outside slope continuing to the side surface of the bottom part. When a load is applied in the axial direction in the state where the container stands upright on the grounding surface, the shape of the bottom part changes reversibly such that the bottom plate part is depressed inwardly to the container. Thus, it is possible to avoid deformation of the container into an unintended shape if a load is applied to the container in the axial direction, and to ensure the rigidity thereof.

1 . A synthetic resin container comprising a mouth part, a trunk part and a bottom part, wherein
 the bottom part includes a bottom plate part which is present at a center of the bottom part and a peripheral part which is positioned at a periphery of the bottom plate part,   the peripheral part includes a grounding part having an inside slope which rises outwardly of the container with an outer peripheral edge of the bottom plate part being a starting point, and an outside slope which continues to a side surface of the bottom part,   the peripheral part includes a plurality of groove parts which extends in a radial direction with the outer peripheral edge of the bottom plate part being the starting point, to divide the grounding part into a plurality of parts along a circumferential direction at substantially equal angular intervals,   the container includes a first virtual surface including an axis of the container or an axis of the bottom part and dividing the grounding part into two parts in a circumferential direction, and a second virtual surface including the axis of the container or the axis of the bottom part and dividing the groove part into two parts in the circumferential direction,   in an overlapped virtual surface wherein the first virtual surface and the second virtual surface are rotated around the axis of the container or the axis of the bottom part to overlap with each other,   when the container is placed upright on a grounding surface by defining an intersection of the grounding part and a grounding surface as C, and   when a line CF connecting a point F on the groove part in the overlapped virtual surface and the intersecting point C orthogonally crosses a tangent for the groove part at the point F in the overlapped virtual surface,   an angle formed by the tangent and the grounding surface is 3 to 20°, and   when a load is applied in an axial direction in a state where the container stands upright on the grounding surface, a shape of the bottom part changes reversibly such that the bottom plate part is depressed inwardly to the container.   
     
     
         2 . The synthetic resin container according to  claim 1 , wherein in the overlapped virtual surface, when an intersection of the inside slope of the grounding part and the groove part is taken as A, and an intersection of the outside slope of the grounding part and the groove part is taken as B, an angle formed by the intersections A, C and B (<ACB) is obtuse. 
     
     
         3 . The synthetic resin container according to  claim 1 , wherein in the overlapped virtual surface, when an intersection of the outside slope of the grounding part and the groove part is taken as B,
 when a projection relative to the grounding surface of the intersection B, which is parallel to the axial core of the container or the axial core of the bottom part, is taken as E, and   when an intersection of the axial core of the container or the axial core of the bottom part and the grounding surface is taken as O,   a ratio (OC/OE) of a length of a line OC relative to a length of a line OE is 0.5 to 0.9.   
     
     
         4 . The synthetic resin container according to  claim 3 , wherein a ratio (2 OC/dmax) of a double of the length of the line OC relative to a maximum trunk diameter (dmax) of the container is 0.5 to 0.9. 
     
     
         5 . The synthetic resin container according to  claim 1 , wherein a step part is provided concentrically with the bottom plate part at a position nearer to the center than the outer peripheral edge of the bottom plate part. 
     
     
         6 . The synthetic resin container according to  claim 1 , wherein the bottom plate part is formed to protrude inwardly of the container.