PACKAGING BAG FOR USE IN MICROWAVE OVEN

摘要

PROBLEM TO BE SOLVED: To provide a packaging bag to be used in a microwave oven which automatically releases pressurized vapor out of a tightly sealed system on heating by a microwave oven and is effective for preserving quality of food easily deteriorative by transmission of outside light. SOLUTION: The packaging bag which is formed of a laminate plastic material in which a heat-resistant base layer 1, a middle layer 2 and a sealant layer 3 are stacked in this order starting from the surface side is given an automatic releasing function by high-temperature softening resin layer 2-2 which declines in laminate adhesive strength at the high temperature provided at a specified position on the planar surface of the middle layer 2 for releasing the inside vapor, and a shading layer made up by combination of a white resin layer 3-1 and a black resin layer or by combination of the white resin layer 3-1 and a colored resin layer 3-2 is formed at the sealant layer 3.