Metal-resin composite container

Abstract

Provided is a metal-resin composite container in which a flange portion formed of metal and a container portion formed of resin are joined together by overlapping of a flange vertical wall projecting from the flange portion and a container vertical wall projecting from the container portion. This overlapping prevents separation of the metal flange portion and the resin container portion caused by deformation of the resin container portion. The metal-resin composite container has a plurality of engagement parts each comprising a convex portion formed partially on the container vertical wall and a concave portion formed partially on the flange vertical wall and engaged with the convex portion. This convex-concave engagement allows gravity which acts on the container portion to be received by the concave portion of the flange portion and prevents cracking caused by excessive stress concentration.

What is claimed is: 
     
         1 . A metal-resin composite container, comprising a frame-shaped flange portion formed of metal, and a container portion formed of resin and integrally joined to an opening peripheral portion of the flange portion, wherein:
 the flange portion has a ring-shaped flange vertical wall projecting toward the container portion, and the container portion has a ring-shaped container vertical wall projecting toward the flange portion, the flange portion and the container portion being integrally joined by overlapping of the flange vertical wall and the container vertical wall; and   the metal-resin composite container has a plurality of engagement parts each comprising a convex portion formed partially on an external surface or an internal surface of the container vertical wall and a concave portion formed partially on an internal surface or an external surface of the flange vertical wall and engaged with the convex portion.   
     
     
         2 . The metal-resin composite container according to  claim 1 , wherein at least a pair of engagement parts are provided in such positions as to oppose each other across an opening of the flange portion or the container portion. 
     
     
         3 . The metal-resin composite container according to  claim 1 , wherein at least one of convex portions have an undercut shape. 
     
     
         4 . The metal-resin composite container according to  claim 1 , wherein a fore end surface of the container vertical wall contacts a step portion formed on the internal surface or the external surface of the flange vertical wall, and one or more second convex portions formed on the fore end surface are respectively engaged with one or more second concave portions formed on the step portion. 
     
     
         5 . The metal-resin composite container according to  claim 1 , wherein at least the flange vertical wall of the flange portion has a polar functional group on a surface thereof, and at least the container vertical wall of the container portion contains an adhesion-improving agent including an adhesive functional group to make an interaction with the polar functional group, and
 the flange vertical wall and the container vertical wall are joined together by the interaction between the polar functional group and the adhesive functional group.   
     
     
         6 . The metal-resin composite container according to  claim 1 , wherein the flange portion and the container portion have flat portions having flat surfaces and curved portions projecting inward respectively from the flat portions, and
 each engagement parts is formed on the flat portion.