Multilayer Packaging Structure Maintaining Gas Barrier After Extrusion Lamination

The patent applies preliminary action by forming a protective layer containing phosphorus compound on the aluminum-containing layered product before subjecting it to extrusion coating lamination. This pre-formed layer prevents the deterioration of gas barrier properties that would otherwise occur during the subsequent lamination process. The phosphorus compound layer acts as a protective barrier that maintains the integrity of the underlying gas barrier structure.

The patent employs composite materials by creating a multilayer structure that combines different materials with complementary properties: a base layered product containing aluminum for gas barrier properties, and an additional layer containing phosphorus compound for protective functions. This composite structure allows the material to simultaneously achieve heat-sealing capability from the lamination while maintaining gas barrier properties through the phosphorus-containing protective layer.

The patent applies local quality by creating distinct layers with different properties: the aluminum-containing layer provides gas barrier and light shielding properties where needed, while the phosphorus compound-containing layer provides transparency and microwave safety in its region. This spatial differentiation of functions allows the multilayer structure to simultaneously achieve opacity/gas barrier in the aluminum layer and transparency/microwave compatibility in the phosphorus layer.

The patent uses composite materials to combine the advantages of different materials: aluminum provides excellent gas barrier properties, while the phosphorus compound provides transparency and microwave safety. The composite multilayer structure integrates these materials so that the final product achieves both gas barrier performance and visual inspection capability, as well as microwave compatibility.

The patent merges (combining) multiple approaches by integrating both aluminum-containing layers and phosphorus compound-containing layers into a single multilayer structure. This combination allows the system to achieve the transparency and microwave safety associated with phosphorus compounds while simultaneously obtaining the superior gas barrier properties of aluminum, thereby resolving the trade-off between transparency and gas barrier performance.

The patent employs composite materials by creating a multilayer structure that combines aluminum-containing layers with phosphorus compound-containing layers. This composite approach allows the material to simultaneously achieve transparency and microwave safety from the phosphorus layer while maintaining high gas barrier properties from the aluminum layer, overcoming the limitations of using either material alone.