Energy Absorbing Blends

Abstract

A composite material which is elastic, which exhibits a resistive load under deformation which increases with the rate of deformation, which is unfoamed or foamed, comminuted or uncomminuted and which comprises i) a first polymer-based elastic material and ii) a second polymer-based material, different from i), which exhibits dilatancy in the absence of i) wherein ii) is entrapped in a solid matrix of i), the composite material being unfoamed or, when foamed, preparable by incorporating ii) with i) prior to foaming.

1 . A composite material which is elastic, exhibits a resistive load under deformation which increases with the rate of deformation, is comminuted or uncomminuted and which comprises:
 i) a first polymer-based elastic material; and   ii) a second polymer-based material, different from i) which exhibits dilatancy in the absence of i) wherein a combination of one or more polymers together with a finely divided particulate material provides dilatancy, and wherein ii) is entrapped in a solid matrix of i),   the composite material being unfoamed or, when foamed, preparable by incorporating ii) with i) prior to foaming.   
     
     
         2 . A composite material according to  claim 1 , wherein the first material i) and second material ii) are in intimate admixture. 
     
     
         3 . A composite material according to  claim 2 , wherein the admixture is prepared by mixing i) and ii) in a semi-molten state or molten state. 
     
     
         4 . A composite material according to  claim 1 , wherein the second material ii) forms from 5% to 80% by volume of the composite material. 
     
     
         5 . A composite material according to  claim 1 , wherein the polymer comprising the first material i) comprises EVA or an olefin polymer. 
     
     
         6 . A composite material according to  claim 1 , wherein the polymer comprising the first material i) comprises an elastomer. 
     
     
         7 . A composite material according to  claim 6 , wherein the elastomer is a natural elastomer. 
     
     
         8 . A composite material according to  claim 6 , wherein the elastomer is a synthetic elastomer. 
     
     
         9 . A composite material according to  claim 8 , wherein the synthetic elastomer is a silicone rubber, a polyurethane or an EP rubber. 
     
     
         10 . A composite material according to  claim 8 , wherein the synthetic elastomer is a thermoplastic elastomer. 
     
     
         11 . A composite material according to  claim 10 , wherein the thermoplastic elastomer comprises a polyester. 
     
     
         12 . A composite material according to  claim 1 , wherein the composite material is comminuted. 
     
     
         13 . A composite material according to  claim 1  which has been subsequently foamed. 
     
     
         14 . A composite material according to  claim 13 , wherein the cells include, as a pneumatogen, a gas, vapor, supercritical liquid, or a precursor thereof. 
     
     
         15 . A shaped article comprising a composite material according to  claim 1 . 
     
     
         16 . A textile or web including shaped articles according to  claim 15 . 
     
     
         17 . An impact protection system including a composite material as claimed in  claim 1 . 
     
     
         18 . An impact protection system according to  claim 17 , which is self-molding in service. 
     
     
         19 . A composite material according to  claim 2 , wherein the first material i) and second material ii) are blended together in intimate admixture. 
     
     
         20 . A composite material according to  claim 4 , wherein the second material ii) forms from 10% to 80% by volume of the composite material. 
     
     
         21 . A composite material according to  claim 4 , wherein the second material ii) forms from 15% to 40% by weight of the composite volume. 
     
     
         22 . A composite material according to  claim 5 , wherein the polymer comprising the first material i) comprises polypropylene or an ethylene polymer. 
     
     
         23 . A composite material according to  claim 22 , wherein the polymer comprising the first material i) comprises high pressure polyethylene (LDPE), LLDPE or HDPE. 
     
     
         24 . A composite material according to  claim 7 , wherein the elastomer is latex rubber. 
     
     
         25 . A composite material according to  claim 9 , wherein the synthetic elastomer is EPDM.