Phase change material (PCM) compositions for thermal management

Abstract

The present invention relates to a Phase Change Material (PCM) composition comprising a) from 20 to 80 wt % of a PCM; and b) from 20 to 80 wt % of one or more polymers chosen from the group consisting of b1) Very Low Density Polyethylene (VLDPE) having a density equal or lower than 0.910 g/cm 3 measured according to ASTM 792; b2) Ethylene Propylene Rubber (EPR) having a density equal or lower than 0.900 g/cm 3 measured according to ASTM 792; b3) Styrene Ethylene Butadiene Styrene (SEBS) copolymers; and b4) Styrene Butadiene Styrene (SBS) copolymers. The PCM composition of the present invention can be used in applications where thermal management is needed, like for example in building, automotive, packaging, garments and footwear.

1 . Phase Change Material (PCM) composition comprising: 
 a) from 20 to 80 wt % of a PCM; and    b) from 20 to 80 wt % of one or more polymers chosen from the group consisting of: 
 b1) Very Low Density Polyethylene (VLDPE) having a density equal or lower than 0.910 g/cm 3  measured according to ASTM 792;  
 b2) Ethylene Propylene Rubber (EPR) having a density equal or lower than 0.900 g/cm 3 ;  
 b3) Styrene Ethylene Butadiene Styrene (SEBS) copolymers; and  
 b4) Styrene Butadiene Styrene (SBS) copolymers;  
   the weight percentages being based on the total weight of the composition.    
   
   
       2 . The PCM composition according to  claim 1 , wherein the EPR having a density equal or lower than 0.900 g/cm 3  is Ethylene Propylene Diene Methylene (EPDM), Ethylene Propylene Methylene (EPM) and mixtures thereof.  
   
   
       3 . The PCM composition according to  claim 1 , wherein the one or more polymers is VLDPE having a density equal or lower than 0.910 g/cm 3 .  
   
   
       4 . The PCM composition according to  claim 1 , wherein the PCM is one or more crystalline alkyl hydrocarbons.  
   
   
       5 . The PCM composition according to  claim 1 , further comprising from 10 to 40 wt % of an inert powder having an absorption capacity of at least 50 wt %, the weight percentages being based on the dried mass of the inert powder.  
   
   
       6 . The PCM composition according to  claim 5 , wherein the inert powder has an absorption capacity of at least 120 wt %, the weight percentages being based on the dried mass of the inert powder.  
   
   
       7 . The PCM composition according to  claim 5 , wherein the inert powder is silicate, one or more flame retardant fillers and mixtures thereof.  
   
   
       8 . The PCM composition according to  claim 7 , wherein the one or more flame retardant fillers are chosen among aluminum trihydrate, magnesium hydroxide, melamine pyrophosphate, melamine cyanurate, one or more brominated fillers and mixtures thereof.  
   
   
       9 . The PCM composition according to  claim 1  comprising from 30 to 50 wt % of the one or more polymers.  
   
   
       10 . The PCM composition according to  claim 1  comprising from 50 to 70 wt % of PCM.  
   
   
       11 . The PCM composition according to  claim 1 , wherein the one or more polymers are grafted with 0.2 to 3 wt % of a carboxylic acid or carboxylic acid anhydride functionality, the weight percentages being based on the total weight of the one or more polymers.  
   
   
       12 . The PCM composition according to  claim 1 , wherein the density of the VLDPE is between 0.800 and 0.910.  
   
   
       13 . The PCM composition according to  claim 1 , further comprising antioxidants and UV filters.  
   
   
       14 . The PCM composition according to  claim 1 , wherein the one or more polymers are cross-linked.  
   
   
       15 . A sheet made with a PCM composition as claimed in  claim 1 .  
   
   
       16 . The sheet according to  claim 15  having a thickness between 0.5 and 10 mm.  
   
   
       17 . A multilayer structure comprising at least one PCM sheet (A) according to  claim 15  which is adjacent to at least one layer (B) made of aluminum, polyester vacuum coated with aluminum, one or more flame retardant polymer composition, plaster, rock-wool insulation, glass-wool insulation and foamed polystyrene.  
   
   
       18 . The multilayer structure of  claim 17  wherein the at least one sheet (A) is positioned between two layers (B 1 , B 2 ) independently made of aluminum, polyester vacuum coated with aluminum, one or more flame retardant polymer composition, plaster, rock-wool insulation, glass-wool insulation and foamed polystyrene.  
   
   
       19 . The multilayer structure of  claim 17 , comprising in the following sequence: 
 c) at least one sheet (A);    d) at least one layer (B) positioned adjacent to the at least one sheet (A);    e) one or more additional layers (C) positioned adjacent to the at least one layer (B), said one or more additional layers (C) being independently made of aluminum, polyester vacuum coated with aluminum, one or more flame retardant polymer composition, plaster, rock-wool insulation, glass-wool insulation and foamed polystyrene.    
   
   
       20 . The multilayer structure of  claim 18 , further comprising one or more additional layers (C) positioned adjacent and externally to one or more of the layers (B 1 , B 2 ), said one or more additional layers (C) being independently made of aluminum, polyester vacuum coated with aluminum, one or more flame retardant polymer composition, plaster, rock-wool insulation, glass-wool insulation and foamed polystyrene.  
   
   
       21 . A molded part made of a PCM composition as claimed in  claim 1.