Laminate packaging material

A laminate packaging material for use with food products, and a retortable pouch (10) comprising that material, are disclosed. The laminate material includes an outer polyethylene terephthalate layer (20), a nylon second layer (22), and a polypropylene inner layer (24). A solventless adhesive (62,64) is used to bond the layers together. The solventless adhesive includes surface-modified exfoliated montmorillonite clay platelets. The platelets lie generally parallel to the plane of the laminate, and overlap to form a barrier to oxygen and other volatile materials. The retortable pouch (40) is formed by heat sealing the edges one of more sheets of the laminate such that the polypropylene layers face inward and are welded together. The pouch and its contents can then be pasteurized by heat-treatment without degradation of the laminate or the heat seal (44).