Heat Generating Body and Process For Producing Heat Generating Body

Abstract

There is provided a heat generating body which by forming a temporary adhering part upon temporary adhesion between a substrate and a heat generating composition molded body and a covering material with an adhesive layer and subsequent heat sealing, realizes higher line speed, thereby largely improving the productivity, does not generate position deviation of the heat generating composition molded body in welding the substrate and the covering material, is able to be heat sealed and is free from seal failure. A heat generating body as formed by laminating a heat generating composition molded body resulting from molding of a heat generating composition containing, as essential components, an exothermic substance, a carbon component, a reaction accelerator and water and having a water mobility value of from 0.01 to 20 on a substrate, covering by a covering material and heat sealing the periphery of the heat generating composition molded body, is characterized in that the substrate and the covering material are temporarily adhered with a sticky layer, the temporarily adhered portion is heat sealed with a heat seal layer which the substrate and/or the covering material has, the sticky layer component and the heat seal layer component are co-present in the heat seal part, and the heat seal part has a seal strength at 60° C. of 0.8 kg/25 mm or more.

1 . A heat generating body as formed by laminating a heat generating composition molded body resulting from molding of a heat generating composition containing, as essential components, an exothermic substance, a carbon component, a reaction accelerator and water and having a water mobility value of from 0.1 to 20 on a substrate, covering by a covering material and heat sealing the periphery of the heat generating composition molded body, characterized in that:
 the substrate and the covering material are temporarily adhered with a sticky layer, the temporarily adhered portion is heat sealed with a heat seal layer which the substrate and/or the covering material has, the sticky layer component and the heat seal layer component are co-present in the heat seal part, and the heat seal part has a seal strength at 60° C. of 0.8 kg/25 mm or more.   
   
   
       2 . The heat generating body according to  claim 1 , characterized in that at least a part of the heat seal part has a region having an air vent part heat sealed therein. 
   
   
       3 . The heat generating body according to  claim 1 , characterized in that, the sticky layer is constituted of a hot melt based adhesive. 
   
   
       4 . The heat generating body according to  claim 1 , characterized in that the total thickness of the heat seal layer is the thickness of the sticky layer or more. 
   
   
       5 . The heat generating body according to  claim 1 , characterized in that the sticky layer has a thickness of from 0.1 to 100 μm. 
   
   
       6 . The heat generating body according to  claim 1 , characterized in that the sticky layer has a void. 
   
   
       7 . The heat generating body according to  claim 1 , characterized in that a mixed part of the heat seal layer component and the adhesive layer component is present in the heat seal part. 
   
   
       8 . The heat generating body according to  claim 1 , characterized in that the substrate and the covering material are formed of an extensible raw material. 
   
   
       9 . The heat generating body according to  claim 1 , characterized in that the heat generating composition molded body is sectioned by a sectioned part which is a heat seal part and is disposed in a plural number. 
   
   
       10 . The heat generating body according to  claim 1 , characterized in that the exothermic substance in the heat generating composition comprising iron powder particles, and the iron powder particles have iron oxide film. 
   
   
       11 . The heat generating body according to  claim 1 , characterized in that the heat generating composition molded body is compression treated. 
   
   
       12 . The heat generating body according to  claim 1 , characterized in that after heat sealing, at least a part of the heat generating composition molded body is moved into the temporary adhering part which is not heat sealed, thereby deadhering the temporary adhering part which is not heat sealed. 
   
   
       13 . The heat generating body according to  claim 1 , characterized in that the heat generating body has a fixing measure on the exposed surface thereof. 
   
   
       14 . A process for producing a heat generating body, characterized in that an air-permeable substrate and/or covering material at least has a heat sealable heat seal layer; a heat generating composition molded body resulting from molding of a heat generating composition containing, as essential components, an iron powder, a carbon component, a reaction accelerator and water and having a water mobility value of from 0.01 to 20 is laminated on the substrate; a hot melt based adhesive is provided as a sticky layer thereon by a melt blow system; the covering material is covered thereon; the heat generating composition molded body and/or the substrate is temporarily adhered to the covering material by temporary adhesion rolls; the periphery of the heat generating composition molded body is then heat sealed; and the seal part has a seal strength at 60° C. of 0.8 kg/25 mm or more. 
   
   
       15 . The process for producing a heat generating body as according to  claim 14 , characterized in that after temporarily adhering the outer circumference of the heat generating body, the outer circumstance of the heat generating body is heat sealed while retaining an air vent part. 
   
   
       16 . The process for producing a heat generating body according to  claim 14 , characterized in that heat sealing is achieved by using heat rolls having the heat seal part smaller than the temporary adhering part in the temporary adhesion rolls. 
   
   
       17 . The process for producing a heat generating body according to  claim 14 , characterized in that the heat generating composition molded body is moved into the temporary adhering part which is not heat sealed, thereby deadhering the temporary adhering part which is not heat sealed.