Thermal insulation and method of producing the same

Abstract

Provided is a thermal insulation having both excellent thermal insulating performance and excellent strength, and a method of producing the same. A method of producing a thermal insulation according to the present invention includes curing (S 2 ) a dry-pressed compact, including silica fine particles each having an average particle diameter of 50 nm or less and a reinforcement fiber, at a relative humidity of 70% or more.

1 . A method of producing a thermal insulation, comprising curing a dry-pressed compact containing silica fine particles each having an average particle diameter of 50 nm or less and a reinforcement fiber, at a relative humidity of 70% or more. 
     
     
         2 . The method of producing a thermal insulation according to  claim 1 , wherein the dry-pressed compact is free of a binder. 
     
     
         3 . The method of producing a thermal insulation according to  claim 1 , wherein the dry-pressed compact comprises 50 to 98 mass % of the silica fine particles and 2 to 20 mass % of the reinforcement fiber. 
     
     
         4 . The method of producing a thermal insulation according to  claim 1 , wherein the dry-pressed compact comprises at least one of an alkaline-earth metal hydroxide and an alkali metal hydroxide. 
     
     
         5 . The method of producing a thermal insulation according to  claim 4 , wherein the dry-pressed compact comprises at least one of the alkaline-earth metal hydroxide and the alkali metal hydroxide, each at 0.1 to 10 parts by weight with respect to 100 parts by weight of a raw material for the thermal insulation comprising the silica fine particles, and the reinforcement fiber. 
     
     
         6 . A thermal insulation, which is produced by the method according to  claim 1 . 
     
     
         7 . A thermal insulation, comprising silica fine particles each having an average particle diameter of 50 nm or less and a reinforcement fiber, wherein the thermal insulation has a bulk density of 190 to 600 kg/m 3  and has a compressive strength of 0.65 MPa or more. 
     
     
         8 . The thermal insulation according to  claim 7 , wherein the thermal insulation is free of a binder. 
     
     
         9 . The thermal insulation according to  claim 7 , comprising 50 to 98 mass % of the silica fine particles and 2 to 20 mass % of the reinforcement fiber. 
     
     
         10 . The thermal insulation according to  claim 7 , further comprising at least one of an alkaline-earth metal and an alkali metal in addition to the silica fine particles and the reinforcement fiber. 
     
     
         11 . The thermal insulation according to  claim 10 , comprising at least one of the alkaline-earth metal and the alkali metal, each at 0.1 to 10 parts by weight with respect to 100 parts by weight of a raw material for a thermal insulation containing the silica fine particles, and the reinforcement fiber. 
     
     
         12 . The thermal insulation according to  claim 7 , wherein the thermal insulation has a thermal conductivity at 600° C. of 0.05 W/(m·K) or less.