Laminate for radiative cooling and preparing method thereof

Abstract

A laminate for radiative cooling includes a porous base layer including a visible-ray reflective polymer and having nano-sized pores formed in the visible-ray reflective polymer, and a coating layer formed on one face of the porous base layer and including an infrared-ray emissive polymer.

What is claimed is: 
     
         1 . A method for preparing a laminate for radiative cooling, the method comprising:
 applying and curing a raw material composition containing a visible-ray reflective polymer and pore-forming inorganic particles to form a cured film;   etching and removing the pore-forming inorganic particles from the cured film to obtain a porous base layer in which pores derived from the pore-forming inorganic particles are formed; and   forming a coating layer comprising an infrared-ray emissive polymer on a face of the porous base layer.   
     
     
         2 . The method of  claim 1 , wherein the visible-ray reflective polymer and the infrared-ray emissive polymer each comprises a fluorine-based polymer. 
     
     
         3 . The method of  claim 2 , wherein the fluorine-based polymer comprises a copolymer having a hydrofluoroolefin (HFO)-derived repeating unit and a perfluoroolefin (PFO)-derived repeating unit. 
     
     
         4 . The method of  claim 3 , wherein the fluorine-based polymer comprises poly(vinylidene fluoride-hexafluoropropylene). 
     
     
         5 . The method of  claim 1 , wherein the pore-forming inorganic particles comprise a compound or element selected from a group consisting of silicon dioxide (SiO 2 ), titanium dioxide (TiO 2 ), aluminum oxide (Al 2 O 3 ), aluminum (Al), silicon nitride (Si 3 N 4 ), and combinations thereof. 
     
     
         6 . The method of  claim 1 , wherein the pore-forming inorganic particles have an average diameter in a range of 400 to 600 nm. 
     
     
         7 . The method of  claim 1 , wherein the raw material composition comprises the visible-ray reflective polymer and the pore-forming inorganic particles in a mass ratio in a range of 1:0.8 to 1:5. 
     
     
         8 . The method of  claim 1 , wherein the forming of the cured film comprises:
 applying the raw material composition to form an applied film; and   heating the applied film at a temperature in a range of 40° C. to 80° C. for 2 to 5 hours.   
     
     
         9 . The method of  claim 1 , wherein the forming of the pores comprises etching and removing the pore-forming inorganic particles using a weak acid solution. 
     
     
         10 . The method of  claim 9 , wherein the weak acid solution comprises a fluorine-based solution. 
     
     
         11 . The method of  claim 1 , wherein the forming of the coating layer comprises applying and curing a coating layer composition containing the infrared-ray emissive polymer. 
     
     
         12 . The method of  claim 10 , wherein the curing carried out at a temperature in a range of 50 to 90° C. for 1 to 4 hours.