LATENT HEAT TYPE MULTI-LAYER HEAT STORAGE MATERIAL

PURPOSE: To provide a latent heat type multi-layer heat storage material having improved heat storage properties and shape retention, by using high-density polyethylene as a core and coating the outer layer thereof with a resin having a m.p. higher than that of the polyethylene. CONSTITUTION: High-density polyethylene having a density of 0.960g/cm3 or above is used as a core, and the outer layer thereof is coated with a resin having a m.p. higher than that of said polyethylene. Preferred high-density polyethylene includes those having a crystallinity index of 80% or above as measured by X-rays and an MW of 1,000W100,000, because they are easily fused and the heat of fusion is high. Examples of the resins used for the coating are polypropylene, poly-4-methyl-1-pentene, and polyethylene terephthalate. The multi-layer heat storage material can be prepd. by co-extrusion, multi-layer injection molding, extrusion coating, etc.COPYRIGHT: (C)1984,JPO&Japio