Ballistic resistant body armor article

Abstract

Disclosed herein are ballistic resistant articles comprising one or more woven fabric layers woven from yarns having a tenacity of at least 7.3 grams per dtex and a modulus of at least 100 grams per dtex and one or more sheet layers comprising a carbon nanotube-polymer composite, the composite comprising randomly oriented carbon nanotubes embedded in a condensation polymer.

What is claimed is: 
     
         1 . A ballistic resistant article, comprising:
 (1) one or more woven fabric layers woven from yarns having a tenacity of at least 7.3 grams per dtex and a modulus of at least 100 grams per dtex; and   (2) one or more sheet layers comprising a carbon nanotube-polymer composite, the composite comprising:
 (a) randomly oriented carbon nanotubes entangled to form a planar structure, and 
 (b) a condensation polymer, wherein the randomly oriented carbon nanotubes are embedded in the condensation polymer; 
   wherein:   (i) the composite comprises from about 15 weight percent to about 80 weight percent carbon nanotubes based on the combined weight of the carbon nanotubes and the condensation polymer;   (ii) the woven fabric layers and the sheet layers are stacked together to form a core section comprising one or more woven fabric layers and one or more sheet layers; and
 (iii) the sheet layers comprise from about 0.25 weight percent to about 15 weight percent of the total weight of the article. 
   
     
     
         2 . The article of  claim 1 , wherein the yarns have linear density of 50 dtex to 4500 dtex, a tenacity of 10 g/dtex to 65 g/dtex, a modulus of 150 g/dtex to 2700 g/dtex, and an elongation to break of 1 percent to 8 percent. 
     
     
         3 . The article of  claim 1 , wherein the yarns are made of filaments made from a polymer selected from the group consisting of polyamides, polyolefins, polyazoles, and mixtures thereof. 
     
     
         4 . The article of  claim 1 , wherein the carbon nanotubes comprise single wall nanotubes, multiwall nanotubes, or mixtures thereof, and the carbon nanotubes have an average longest dimension in the range of about 1 μm to about 1000 μm. 
     
     
         5 . The article of  claim 1 , wherein the condensation polymer comprises polyester, polyamide, polyaramid, or polyacetal. 
     
     
         6 . The article of  claim 5 , wherein the polyester comprises polybutylene terephthalate and the weight percent of the nanotubes is from about 40 weight percent to about 60 weight percent. 
     
     
         7 . The article of  claim 1 , wherein the composite has an areal density in the range of about 5 grams per square meter to about 100 grams per square meter. 
     
     
         8 . The article of  claim 1 , wherein the composite has an average acoustic velocity of at least 2250 m/sec. 
     
     
         9 . The article of  claim 1 , wherein each of the sheet layers has a thickness between about 0.01 mm and 0.1 mm. 
     
     
         10 . The article of  claim 1 , wherein the sheet layers are isotropic or substantially isotropic with regard to the ratio of maximum strain to failure value to minimum strain to failure value. 
     
     
         11 . The article of  claim 1 , wherein the sheet layers comprise 0.25 weight percent to 5 weight percent of the total weight of the article. 
     
     
         12 . The article of  claim 1 , wherein the woven fabric layers and the sheet layers, stacked together, have an areal density between 2.5 to 6.5 kg/m 2 . 
     
     
         13 . The article of  claim 1 , wherein the core section contains 1 to 60 of the woven fabric layers and 1 to 60 of the sheet layers. 
     
     
         14 . The article of  claim 1 , wherein the core section comprises a number of repeat units, each repeat unit comprising one or more woven fabric layers and one or more sheet layers. 
     
     
         15 . The article of  claim 14 , wherein the number of repeat units is from 1 to 10. 
     
     
         16 . The article of  claim 14 , wherein each repeat unit contains, in order, 1 to 5 of the woven layers and 1 to 5 of the sheet layers. 
     
     
         17 . The article of  claim 1 , wherein the core section has a first-strike surface and a body-facing surface, and wherein the article further comprises a first strike section and a body-facing section, the first strike section comprising a plurality of the woven fabric layers stacked together and in contact with the first-strike surface, and the body-facing section comprising a plurality of the woven fabric layers stacked together and in contact with the body-facing surface. 
     
     
         18 . The article of  claim 17 , wherein the first strike section contains 2 to 30 woven fabric layers stacked together and the body-facing section contains 2 to 30 woven fabric layers stacked together. 
     
     
         19 . The article of  claim 1 , wherein the article has a backface deformation of 30 less than or equal to 44 mm at a projectile velocity (V o ) of 1430 ft/sec plus or minus (+/−) 30 ft/sec (436 m/sec+/−9 m/sec) in accordance with NIJ Standard—0101.06 “Ballistic Resistance of Personal Body Armor”, issued in July 2008.