Dimensionally stable phase change material and a continuous process for making same

Abstract

Methods for producing a dimensionally stable phase change material (PCM), and dimensionally stable PCMs are disclosed. The methods include providing a porous base material, mixing a phase change material having a polar functional group with a substance that increases the polar attraction of the phase change material for the porous base material to form a mixture thereof; and, thereafter, mixing the mixture with the porous base material until a selected saturation of phase change material in the porous base material is reached. The methods may include filtering the porous base material after the selected saturation is reached to form a cake of dimensionally stable PCM and, thereafter, reducing the size of the dimensionally stable PCM to an average mean particle size of about 10 to about 50 μm, or more preferably 20 to 30 μm.

What is claimed is: 
     
         1 . A dimensionally stable phase change material comprising:
 a porous base material having within its pores a selected saturation amount of a mixture of a phase change material having a polar functional group and a substance that increases the polar attraction of the phase change material for the porous base material.   
     
     
         2 . The dimensionally stable phase change material of  claim 1 , wherein the substance that increases the polar attraction of the phase change material comprises vinyl acetate. 
     
     
         3 . The dimensionally stable phase change material of  claim 2 , wherein the substance that increases the polar attraction of the phase change material comprises an ethylene-vinyl acetate copolymer resin. 
     
     
         4 . The dimensionally stable phase change material of  claim 1 , having a maximum of 2% free phase change material leakage and a minimum enthalpy of 125 J/g as measured by differential scanning calorimetry. 
     
     
         5 . The dimensionally stable phase change material of  claim 1 , having an average mean particle size of about 20 to about 30 μm; and wherein the porous base material comprises expanded perlite. 
     
     
         6 . A dimensionally stable phase change material made by a method comprising:
 providing porous particles;   mixing a phase change material having a polar functional group with a substance that increases the polar attraction of the phase change material for the porous base material to form a mixture thereof; and   mixing the mixture with the porous base material until a selected saturation of the mixture in the porous base material is reached.   
     
     
         7 . The dimensionally stable phase change material of  claim 6 , wherein the dimensionally stable phase change material is in the form a cake. 
     
     
         8 . The dimensionally stable phase change material of  claim 7 , wherein the dimensionally stable phase change material has an average mean particle size of about 20 to about 50 μm. 
     
     
         9 . The dimensionally stable phase change material of  claim 6 , wherein the method further comprises adding one or more Lewis acids and/or Lewis bases to the phase change material before mixing with the porous base material. 
     
     
         10 . The dimensionally stable phase change material of  claim 6 , wherein the method further comprises heating while mixing the porous base material with the mixture. 
     
     
         11 . The dimensionally stable phase change material of  claim 6 , wherein mixing of the phase change material and the substance that increases the polar attraction of the phase change material includes mixing equal parts thereof. 
     
     
         12 . The dimensionally stable phase change material of  claim 6 , wherein the polar functional group of the phase change material includes one or more of an alcohol, glycol, ketone, ester, diesters, carboxylic acid, anhydride, epoxide, amine, nitrile, carbonate, and amide. 
     
     
         13 . The dimensionally stable phase change material of  claim 6 , wherein the porous base material comprises expanded perlite. 
     
     
         14 . The dimensionally stable phase change material of  claim 6 , wherein the phase change material comprises methyl palmitate. 
     
     
         15 . The dimensionally stable phase change material of  claim 6 , wherein the substance that increases the polar attraction of the phase change material comprises vinyl acetate. 
     
     
         16 . The dimensionally stable phase change material of  claim 15 , wherein the substance that increases the polar attraction of the phase change material comprises an ethylene-vinyl acetate copolymer resin. 
     
     
         17 . The dimensionally stable phase change material of  claim 8 , wherein the dimensionally stable phase change material has a maximum of 2% free phase change material leakage and a minimum enthalpy of 125 J/g as measured by differential scanning calorimetry. 
     
     
         18 . The dimensionally stable phase change material of  claim 6 , further comprising, after the selected saturation of the modified phase change material in the porous substrate is reached, emulsifying the mixture until an average mean particle size is within about 10 to about 50 μm.