LATENT HEAT STORAGE MATERIAL

PURPOSE: To obtain the title material which can release the pressure at the time of expansion of the storage material and can easily increase the volume of stored heat by swelling a polyolefin sheet with a changeable phase material to provide an uneven surface on at least one side of it. CONSTITUTION: A polyolefin sheet (e.g. PE or PP) is swelled with a changeable phase material (e.g. a crystalline n-parafin or a crystalline fatty acid) to provide an uneven surface on at least one side of it, thereby producing a latent heat storage material. Because of this uneven surface, when the changeable phase material is melted and volume expansion takes place, it absorbs the pressure, whereas a planar latent heat storage material has no place for the escape of the pressure. Therefore, fracture and migration of the changeable phase material hardly occur and because of the large surface area per unit area which releases (or absorbs) the heat, the heat storage capacity can be easily increased as compared with the planar latent heat storage material.COPYRIGHT: (C)1991,JPO&Japio