Heat storage materials and methods of manufacturing the heat storage materials

Abstract

The present invention includes a heat storage granule having a plurality of microcapsules mixed with a binder and granulated into the heat storage granule. Each of the microcapsules may have an outer case and a phase change material contained therein. The outer case may be made of synthetic resin. The phase change material can absorb and dissipate latent heat in response change in temperature. The heat storage granule may have a cover layer that has heat conductivity and resistance against alcohol, both of which may be higher than those of a thermosetting resin or a thermoplastic resin.

1 . A heat storage material comprising:
 a heat storage granule having a plurality of microcapsules mixed with a binder and granulated into the heat storage granule; wherein:   each of the microcapsules has an outer case and a phase change material contained therein,   the outer case is made of synthetic resin,   the phase change material can absorb and dissipate latent heat in response change in temperature; and   the heat storage granule has a cover layer covering a surface of the heat storage granule, the cover layer having heat conductivity and resistance against alcohol, both of which are higher than those of at least one of a thermosetting resin and a thermoplastic resin.   
   
   
       2 . The heat storage material as in  claim 1 , wherein the cover layer comprises a metal layer. 
   
   
       3 . The heat storage material as in  claim 1 , wherein the cover layer comprises a diamond-like carbon layer. 
   
   
       4 . The heat storage material as in  claim 1 , wherein the cover layer comprises an electrolessly deposited nickel layer. 
   
   
       5 . The heat storage material as in  claim 1 , wherein:
 the heat storage granule has voids formed between the microcapsules;   an underlying layer is provided between the cover layer and a surface of the heat storage granule, so that the voids within at least a surface layer part of the heat storage granule are filled with the underlying layer.   
   
   
       6 . The heat storage material as in  claim 1 , wherein the underlying layer is made of a resin having resistance against alcohol. 
   
   
       7 . The heat storage material as in  claim 1 , wherein the heat storage material comprises a plurality of the heat storage granules, the heat storage material is used in combination with an adsorption material for a canister, and the adsorption material can adsorb and desorb a fuel vapor. 
   
   
       8 . A method of manufacturing a heat storage material comprising the steps of:
 granulating a mixture of a plurality of microcapsules and a binder into a plurality of porous heat storage granules each having voids between the microcapsules; wherein:   each of the microcapsules has an outer case and a phase change material contained therein,   the outer case is made of synthetic resin; and   the phase change material can absorb and dissipate latent heat in response change in temperature; and   providing an underlying layer on each of the porous heat storage granules, so that the voids within at least a surface layer part of each of the porous heat storage granules are filled with the underlying layer; and   providing a cover layer on a surface of each of the porous heat storage granules having the underlying layer, the cover layer having heat conductivity and resistance against alcohol, both of which are higher than those of at least one of a thermosetting resin and a thermoplastic resin.   
   
   
       9 . A method of manufacturing a heat storage material comprising the steps of:
 granulating a mixture of a plurality of microcapsules and a liquid binder into a plurality of non-porous heat storage granules; wherein:   each of the microcapsules has an outer case and a phase change material contained therein,   the outer case is made of synthetic resin; and   the phase change material can absorb and dissipate latent heat in response change in temperature; and   providing a cover layer on a surface of each of the non-porous heat storage granules, the cover layer having heat conductivity and resistance against alcohol, both of which are higher than those of at least one of a thermosetting resin and a thermoplastic resin.   
   
   
       10 . The method as in  claim 8 , wherein the step of providing the cover layer comprises electrolessly depositing nickel. 
   
   
       11 . The method as in  claim 9 , wherein the step of providing the cover layer comprises electrolessly depositing nickel. 
   
   
       12 . A heat storage granule comprising:
 a granule body including a plurality of microcapsules each capable of absorbing and dissipating heat in response to change in temperature; and   a metal cover layer formed on a surface of the granule body, so that the microcapsules are prevented from being exposed to the outside of the granule body.   
   
   
       13 . The heat storage granule as in  claim 12 , wherein the metal cover layer is made of nickel. 
   
   
       14 . The heat storage granule as in  claim 12 , further comprising an intermediate layer formed between the granule body and the cover layer, wherein the intermediate layer is made of resin. 
   
   
       15 . A heat storage granule comprising:
 a granule body including a plurality of microcapsules capable of absorbing and dissipating heat in response to change in temperature; and   a carbon cover layer formed on a surface of the granule body, so that the microcapsules are prevented from being exposed to the outside of the granule body.   
   
   
       16 . The heat storage granule as in  claim 15 , wherein the carbon cover layer is made of diamond-like carbon. 
   
   
       17 . The heat storage granule as in  claim 15 , further comprising an intermediate layer formed between the granule body and the cover layer, wherein the intermediate layer is made of resin.