Aerogel blanket and method of production

Abstract

A method of making a nonwoven wet laid aerogel blanket is provided. The aerogel blanket can exhibit improved thermal conductivity, lower corrosivity, lower dust production and a uniform structure. The blanket can be made from an aerogel floc that is formed from a slurry of aerogel particles.

What is claimed is: 
     
         1 . A nonwoven insulation blanket comprising:
 aerogel particles;   fibers; and   a binder, wherein the density of aerogel particles in the upper 10% of a cross section of the blanket is within +/−20% of the density of aerogel particles in the lowest 10% of the cross section.   
     
     
         2 . The nonwoven insulation blanket of  claim 1  comprising an infrared opacifier. 
     
     
         3 . The nonwoven insulation blanket of  claim 1  having a thermal conductivity of less 40 mW/m∘K, than less than 35 mW/m∘K or less than 30 mW/m∘K at 150° C. 
     
     
         4 . The nonwoven insulation blanket of  claim 1  wherein the density of the blanket is less than 0.2 g/cc, less than 0.15 g/cc, less than 0.13 g/cc or less than 0.12 g/cc. 
     
     
         5 . The nonwoven insulation blanket of  claim 1  wherein the blanket is translucent. 
     
     
         6 . The nonwoven insulation blanket of  claim 1  wherein the blanket exhibits corrosivity of less than 5 ppm HCl by ASTM C1617. 
     
     
         7 . The nonwoven insulation blanket of  claim 1  wherein the aerogel particles have an average diameter of less than 2.0 mm. 
     
     
         8 . The nonwoven insulation blanket of  claim 1  wherein all of the aerogel particles have a diameter of less than 4.0 mm. 
     
     
         9 . The nonwoven insulation blanket of  claim 1  wherein the blanket exhibits a flame spread index (ASTM E84) of less than 25 and a smoke developed index of less than 450 (ASTM E84). 
     
     
         10 . The nonwoven insulation blanket of  claim 1  wherein the blanket exhibits shrinkage of less than 2% at 650° C. when tested using ASTM method C356. 
     
     
         11 . The nonwoven insulation blanket of  claim 1  wherein the aerogel particles are hydrophobic and exhibit a water contact angle of greater than 90 degrees. 
     
     
         12 . The nonwoven insulation blanket of  claim 1  wherein the aerogel particles are derived from waterglass. 
     
     
         13 . The nonwoven insulation blanket of  claim 1  wherein the aerogel particles have a caloric content of less than 10 MJ/Kg. 
     
     
         14 . The nonwoven insulation blanket of  claim 1  comprising a polymer comprising polyamine, polyacrylamide, dicyandiamide, or polydiallyldimethylammonium chloride. 
     
     
         15 . The nonwoven insulation blanket of  claim 1  wherein the fibers have an average length less than 5 mm, or none of the fibers have a length greater than 5 mm. 
     
     
         16 . The nonwoven insulation blanket of  claim 1  wherein none of the fibers have a length greater than 5 mm. 
     
     
         17 - 34 . (canceled)