Wettable Heat Generating Composition Compressed Body, Heat Generating Body, and Process for Producing Wettable Heat Generating Composition Compressed Body

Abstract

An object of the invention is to provide a wettable heat generating composition compressed body which has various shapes and various sizes, is wettable and is capable of generating heat upon contact with air. Another object of the invention is to provide a heat generating body having a structure in which the foregoing wettable heat generating composition compressed body is interposed between a substrate and a covering material and at least the periphery of the wettable heat generating composition compressed body is sealed and having an exothermic part having an air-permeable part. A wettable heat generating composition compressed body resulting from compression of a moldable heat generating composition capable of causing an exothermic reaction upon contact with air, which is characterized in that the heat generating composition is one prepared by subjecting a reaction mixture containing, as essential components, an iron powder, a carbon component, a reaction accelerator, a crosslinking type water absorptive polymer and water but not containing a flocculant aid, a flocculant, an agglomeration aid, a dry binder, a dry binding agent, a dry binding material, a sticky raw material, a thickener, an excipient, an alcohol, a crosslinking agent and a plasticizer and having a water content of from 1 to 20% by weight and a water mobility value of less than 0.01 to a contact treatment with an oxidizing gas under circumstances at 0° C. or higher, regulating a temperature rise of the reaction mixture at 1° C. or higher within 10 minutes, and adjusting the water content so as to contain surplus water having a water mobility value of from 0.01 to 20 and has moldability due to the surplus water as a connecting substance, in which the water in the heat generating composition does not function as a barrier layer; that the moldable heat generating composition is molded by in-mold compression by filling in a mold cavity of a mold cavity-provided die to a depth substantially the same as the depth of the mold cavity and compressing to a thickness of from 50 to 99.5% against the depth of the mold cavity; and that the compressed body is non-flexible and has shape holding properties.

1 . A wettable heat generating composition compressed body resulting from compression of a moldable heat generating composition capable of causing an exothermic reaction upon contact with air, characterized in that:
 1) the heat generating composition is one prepared by subjecting a reaction mixture containing, as essential components, an iron powder, a carbon component, a reaction accelerator, a crosslinking type water absorptive polymer and water but not containing a flocculant aid, a flocculant, an agglomeration aid, a dry binder, a dry binding agent, a dry binding material, a sticky raw material, a thickener, an excipient, an alcohol, a crosslinking agent and a plasticizer and having a water content of from 1 to 20% by weight and a water mobility value of less than 0.01 to a contact treatment with an oxidizing gas under circumstances at 0° C. or higher, regulating a temperature rise of the reaction mixture at 1° C. or higher within 10 minutes, and adjusting the water content so as to contain surplus water having a water mobility value of from 0.01 to 20 and has moldability due to the surplus water as a connecting substance, in which the water in the heat generating composition does not function as a barrier layer; that   2) the moldable heat generating composition is molded by in-mold compression by filling in a mold cavity of a mold cavity-provided die to a depth substantially the same as the depth of the mold cavity and compressing to a thickness of from 50 to 99.5% against the depth of the mold cavity; and that   3) the compressed body is non-flexible and has shape holding properties.   
   
   
       2 . The wettable heat generating composition compressed body according to  claim 1 , characterized in that the heat generating composition contains at least one member selected from additional components consisting of a water retaining agent, a pH adjusting agent, a hydrogen formatio inhibitor, an aggregate, a fibrous material, a functional substance, a surfactant, an organosilicon compound, a pyroelectric substance, a moisturizer, a fertilizer component, a hydrophobic polymer compound, a heat generating aid, a metal other than iron, a metal oxide other than iron oxide, an acidic substance, and a mixture thereof. 
   
   
       3 . The wettable heat generating composition compressed body as according to  claim 1 , characterized in that the iron powder comprising particles, a surface of each of which is at least partially covered with an iron oxide film; that the iron oxide film has a thickness of 3 nm or more; and that the active iron powder particles having a region of an oxygen-free iron component in at least one region selected from a central region of the iron powder particles and a region beneath the iron oxide film is contained in an amount of from 20 to 100% by weight. 
   
   
       4 . A heat generating body, characterized by having an exothermic part having a structure in which the wettable heat generating composition compressed body according to  claim 1  is interposed between a substrate and a covering material and at least the periphery of the wettable heat generating composition compressed body is sealed. 
   
   
       5 . The heat generating body according to  claim 4 , characterized in that the exothermic part is an exothermic part in which a plural number of sectional exothermic parts are provided at intervals; that the sectional exothermic parts contain the wettable heat generating composition compressed body; that the wettable heat generating composition compressed body has a height of from 0.1 to 10 mm and a volume of from 0.01 to 30 cm 3 ; and that a ratio of the capacity of the sectional exothermic parts to the volume of the wettable heat generating composition compressed body is from 0.6 to 1.0. 
   
   
       6 . The heat generating body according to  claim 4 , characterized in that in the heat generating body provided with two or more of the sectional exothermic parts, the air-permeable surface is covered by an air permeability adjusting material. 
   
   
       7 . The heat generating body according to  claim 4 , characterized in that an outer periphery of the sealed wettable heat generating composition compressed body is collapsed by an outer pressure. 
   
   
       8 . The heat generating body according to  claim 4 , characterized in that at least a part of one of the exposed surfaces of the heat generating body has a fixing measure. 
   
   
       9 . A process for producing a wettable heat generating composition compressed body resulting from compression of a moldable heat generating composition capable of causing an exothermic reaction upon contact with air, which is characterized by:
 1) using, as a heat generating composition, a moldable heat generating composition prepared by subjecting a reaction mixture containing, as essential components, an iron powder, a carbon component, a reaction accelerator, a crosslinking type water absorptive polymer and water but not containing a flocculant aid, a flocculant, an agglomeration aid, a dry binder, a dry binding agent, a dry binding material, a sticky raw material, a thickener, an excipient, an alcohol, a crosslinking agent and a plasticizer and having a water content of from 1 to 20% by weight and a water mobility value of less than 0.01 to a contact treatment with an oxidizing gas under circumstances at 0° C. or higher, regulating a temperature rise of the reaction mixture at 1° C. or higher within 10 minutes, and adjusting the water content so as to contain surplus water having a water mobility value of from 0.01 to 20, and   2) filling the moldable heat generating composition in a mold cavity of a mold cavity-provided die to a depth substantially the same as the depth of the mold cavity and compressing to a thickness of from 50 to 99.5% against the depth of the mold cavity.