Low thermal expansion film adhesives for multilayer transparent armour and related applications

Abstract

The present disclosure is directed to a composite material comprising a thermoplastic adhesive and nanotubes oriented in the in-plane orientation. In additional aspects, the disclosure includes a laminated armor material comprising the composite and armor materials.

1 . A composite material comprising:
 a) an adhesive; and   b) nanotubes;   wherein the composite material is in a sheet-like formation having x, y and z dimensions, wherein the measurement of the z dimension is less than the x and y dimensions, and wherein a portion of the nanotubes are oriented within the plane in the x and y dimensions of the composite material, and wherein the in-plane orientation of the nanotubes is sufficient to reduce the coefficient of thermal expansion (CTE) of the adhesive.   
     
     
         2 . The composite material of  claim 1 , wherein the CTE of the composite adhesive in the x and y dimensions (CTE x,y ) is less than the CTE of the composite adhesive in the z dimension (CTE z ). 
     
     
         3 . The composite material according to  claim 1 , wherein the amount of nanotubes in the composite material is about 5 wt % to about 50 wt %. 
     
     
         4 . The composite material according to  claim 3 , wherein the amount of nanotubes in the composite material is about 5 wt % to about 25 wt %. 
     
     
         5 . The composite material according to  claim 4 , wherein the amount of nanotubes in the composite material is about 5 wt % to about 20 wt %. 
     
     
         6 . The composite material according to  claim 1 , wherein the amount of nanotubes in the composite material is at least 5 wt %. 
     
     
         7 . The composite material according to  claim 1 , wherein about 80% or more of the nanotubes in the composite material have an average angle of about 30° or less relative to the plane of the sheet defined as the x-y plane. 
     
     
         8 . The composite material according to  claim 1 , wherein the adhesive is a thermoplastic or a thermoset polyurethane. 
     
     
         9 . The composite material according to  claim 1 , wherein the nanotubes comprise carbon nanotubes, boron-nitride nanotubes, boron-carbon-nitrogen nanotubes, silicon-carbide nanotubes, other nanoparticles, hybrids of any two or more thereof, or a combination of any two or more thereof. 
     
     
         10 . The composite material according to  claim 9 , wherein the nanotubes are boron-nitride nanotubes. 
     
     
         11 . The composite material according to  claim 1 , wherein the composite material has a coefficient of thermal expansion of about 3.0 10 −6 /° K to about 100.0×10 −6 /° K. 
     
     
         12 . The composite material of  claim 11 , wherein the composite material has a coefficient of thermal expansion of about 3.0 10 −6 /° K to about 10.0×10 −6 /° K. 
     
     
         13 . The composite material of  claim 11 , wherein the composite material has a coefficient of thermal expansion of about 50.0 10 −6 /° K to about 70.0×10 −6 /° K. 
     
     
         14 . The composite material according to  claim 1 , wherein the z dimension of the composite material is between about 1 μm to about 1000 μm. 
     
     
         15 . A laminated armor material, comprising
 a) two or more armor materials; and   b) an adhesive layer between the armor materials which bonds the armor materials together, wherein the adhesive layer comprises the composite material as defined in  claim 1 .   
     
     
         16 . The laminated armor material according to  claim 15 , wherein about 90% or more of the nanotubes in the composite material have an average angle of about 20° or less relative to the plane of the sheet defined as the x-y plane. 
     
     
         17 . The laminated armor material according to  claim 15 , wherein the armor materials are the same or different and each are independently selected from ceramic, metal, glass, a polymeric material and fibre reinforced polymer composites. 
     
     
         18 . The laminated armor material according to  claim 15 , wherein the armor materials are transparent. 
     
     
         19 . The laminated armor material according to  claim 18 , wherein the transparent armor material is glass or ceramic. 
     
     
         20 . The laminated armor material according to  claim 17 , wherein the polymeric armor material is a thermoplastic material. 
     
     
         21 . The laminated armor material according to  claim 20 , wherein the thermoplastic material is polycarbonate or polymethylmethacrylate. 
     
     
         22 . The laminated armor material according to  claim 15 , wherein the nanotubes comprise carbon nanotubes, boron-nitride nanotubes, boron-carbon-nitrogen nanotubes, silicon-carbide nanotubes, other nanoparticles, hybrids of any two or more thereof, or a combination of any two or more thereof. 
     
     
         23 . The laminated armor material according to  claim 22 , wherein the nanotubes comprise boron nitride nanotubes, or other transparent reinforcing particles. 
     
     
         24 . The laminated armor material according to  claim 15 , wherein the amount of nanotubes in the composite material is about 5 wt % to about 50 wt %. 
     
     
         25 . The laminated armor material according to  claim 15 , wherein the armor materials have a coefficient of thermal expansion of about 1.0 10 −6 /° K to about 10.0×10 −6 /° K, and the composite material has a coefficient of thermal expansion of about 3.0 10 −6 /° K to about 10.0×10 −6 /° K 
     
     
         26 . The laminated armor material according to  claim 15 , wherein a first armor material has a coefficient of thermal expansion of about 1.0 10 −6 /° K to about 10.0×10 −6 /° K, a second armor material has a coefficient of thermal expansion of about 50.0 10 −6 /° K to about 70.0×10 −6 /° K, and the composite material has a coefficient of thermal expansion of about 10.0 10 −6 /° K to about 50.0×10 −6 /° K. 
     
     
         27 . The laminated amor material according to  claim 15 , wherein the composite adhesive layer has a graded composition in the thickness (z) direction. 
     
     
         28 . The laminated armor material according to  claim 15 , wherein the laminated armor material is transparent and comprises a first and second armor material wherein:
 a) the first armor material is glass;   b) the second armor material is polycarbonate or polymethylmethacrylate; and   c) the composite material comprises thermoplastic polyurethane and boron nitride nanotubes.   
     
     
         29 . A process for preparing the composite material of  claim 1 , the process comprising:
 a) obtaining a solution of an polymeric adhesive in a first solvent;   b) obtaining a suspension of nanotubes in a second solvent;   c) mixing the solution of the polymeric adhesive and the suspension of nanotubes together to form a mixture;   d) filtering or spraying the mixture onto a substrate to obtain the composite material of  claim 1 .