Manufacturing method for porous thermal insulation coating layer, porous thermal insulation coating layer and internal combustion engine using the same

Abstract

Disclosed are a manufacturing method for a porous thermal insulation coating layer, a porous thermal insulation coating layer with substantially reduced thermal conductivity and volumetric heat capacity and an internal combustion engine including the porous thermal insulation coating layer thereby having excellent durability.

1 . A method of manufacturing a porous thermal insulation coating layer comprising:
 coating a reaction product obtainable from a reaction of metal alkoxide containing at least one selected from the group consisting of aluminum, zirconia, titanium and silicon with alcohol and water;   drying the coated reaction product at a first temperature; and   performing a thermal treatment at a second temperature that is greater than the first temperature and less than about 300° C.   
     
     
         2 . The method of  claim 1 , wherein the second temperature ranges from about 20° C. to about 220° C. and is greater than the first temperature. 
     
     
         3 . The method of  claim 1 , wherein
 the performing of the thermal treatment at the second temperature is conducted for about 12 hours to 48 hours.   
     
     
         4 . The method of  claim 1 , wherein the first temperature ranges from about 30° C. to about 100° C. 
     
     
         5 . The method of  claim 1 , wherein the second temperature ranges from about 100° C. to about 250° C. 
     
     
         6 . The method of  claim 1 , wherein an amount of about 10 to 100 parts by weight of the alcohol relative to 100 parts by weight of the metal alkoxide of the metal is reacted. 
     
     
         7 . The method of  claim 1 , wherein an amount of about 110 to 500 parts by weight of the water relative to 100 parts by weight of the metal alkoxide of the metal is reacted. 
     
     
         8 . The method of  claim 1 , further comprising,
 before the drying of the coated reaction product at the first temperature, adding a solution including a silane-based compound to the product of the coating step.   
     
     
         9 . The method of  claim 8 , wherein the silane-based compound comprises a silane compound substituted with at least one functional group selected from the group consisting of a C1-C10 alkyl group and a C1-C10 alkoxy group. 
     
     
         10 . The method of  claim 1 , wherein the coated reaction product is dried at the first temperature for about 10 minutes to 500 minutes. 
     
     
         11 - 20 . (canceled)