GB746371A - Improvements in protective structure - Google Patents

Abstract

A structure or material adapted to protect personnel and equipment against the destructive action of high velocity missiles is made from a continuous phase or matrix of rubber-like material having a flexural modulus of from 18,000 to 45,000 pounds per square inch, and having dispersed therein solid particles having a hardness on Moh's scale of 7 or more. The particles may be made of abrasives such as silicon carbide, alundum (fused aluminium oxide), emery, boron carbide, quartz, sharp silica sand, and glass, and are present in a proportion ranging from 40-60 per cent of the total volume. The size of the particles ranges from 8-80 mesh U.S. Standard. The matrix may comprise a heat-cured homogeneous mixture of a potentially reactive phenol-aldehyde resin (cashew nut shell oil modified phenol-aldehyde resins), a butadiene-acrylonitrile rubbery copolymer, and a filler such as diatomaceous earth or carbon black in amount sufficient to raise the flexural modulus to the required value. A hardening agent such as hexamethylenetetramine or paraformaldehyde is incorporated in the mix before curing. The material may be used in laminated form, e.g. with armour-steel or sheet aluminium.