Packaging container for microwave oven

Abstract

A packaging container for a microwave oven. Completion of heating of the container contents and automatic opening of the container can be easily recognized. This can be achieved without requiring a special member and complex steps, but by processing wrapping materials constructing the packaging container. Also provided is a packaging container for a microwave oven, where danger, including spilling of the contents of the container and burning by touching an opening section occurring in heating by a microwave oven, can be avoided. Further provided is a packaging container for a microwave oven, sealed by heat-sealing plastic films and having a steam vent seal section having a weakened section. The steam vent seal section has mark emerging means, and when the steam vent seal section is separated and opened, the means shows different surface-and back face-wrapping materials constituting the steam vent seal section, enabling recognition of opening.

1 - 15 . (canceled)  
   
   
       16 . A packaging container for a microwave oven hermetically sealed by heat-sealing with a plastic film, the packaging container comprising a vapor release seal part having a weakened part, 
 characterized in that the vapor release seal part is provided with a mark developing means with which exfoliation opening of the vapor release seal part can be recognized by an outer color difference between the opened vapor release seal part and adjacent parts caused by opacification or whitening in association with peeling due to cohesion failure of the vapor release seal part.    
   
   
       17 . A packaging container for a microwave oven according to  claim 16 , characterized in that the mark developing means is constituted by providing a color printing layer for an upper layer of the vapor release seal part of at least one plastic film constituting the packaging container on a side of an external surface of the container.  
   
   
       18 . A packaging container for a microwave oven according to  claim 16 , characterized in that the vapor release seal part is formed continuously along a peripheral edge seal part of the packing container.  
   
   
       19 . A packaging container for a microwave oven according to  claim 16 , characterized in that the vapor release seal part is formed separately from the peripheral edge seal part of the packing container.  
   
   
       20 . A packaging container for a microwave oven according to  claim 16 , characterized in that the vapor release seal part is provided with a through-hole, a semi through-hole, or a slit to thereby form a weakened part.  
   
   
       21 . A packaging container for a microwave oven according to  claim 16 , characterized in that a cutout is formed in the packing container inwardly into the container and a periphery edge of the cutout is heat-sealed to thereby form the vapor release seal part having a weakened part.  
   
   
       22 . A packaging container for a microwave oven according to  claim 16 , characterized in that a pouring port forming means is arranged near the vapor release seal part.  
   
   
       23 . A packaging container for a microwave oven according to  claim 16 , characterized in that the packaging container comprises a packaging pouch hermetically sealed by heat-sealing with a plastic film.  
   
   
       24 . A packaging container for a microwave oven according to  claim 23 , characterized in that the packaging pouch comprises a standing pouch.  
   
   
       25 . A packaging container for a microwave oven according to  claim 23 , characterized in that the packaging pouch comprises a packaging pouch having a branched section.  
   
   
       26 . A packaging container for a microwave oven according to  claim 16 , characterized in that the packaging container is hermetically sealed by heat-sealing of a container main body having a flange part with a lid composed of a plastic film.  
   
   
       27 . A packaging container for a microwave oven according to  claim 26 , characterized in that the vapor release seal part is formed by causing a heat-seal part between the flange part of the packaging container and the lid to project toward an inside of the container.