Method to Produce a Composite Material

Abstract

Method of producing an elastic composite material comprising the step of impregnating a fiber fabric with a liquid epoxy system comprising an epoxy resin and a hardener, and curing the impregnated fabric, whereby the epoxy system exhibits a tensile modulus lower than 15 MPa after cure.

1 . Method of producing an elastic composite material comprising the step of
 a) impregnating a fiber fabric with a liquid epoxy system comprising an epoxy resin and a hardener;   b) and curing the impregnated fabric, characterized in that the epoxy system exhibits a tensile modulus lower than 15 MPa when cured and the elastic composite material exhibits a flexural modulus lower than 15 GPa.   
     
     
         2 . Method according to  claim 1 , whereby the epoxy system exhibits the onset of the glass transition temperature Tg at a temperature lower than 0° C. 
     
     
         3 . Method according to  claim 1 , whereby the epoxy system exhibits at 25° C. a viscosity lower than 450 mPa·s. 
     
     
         4 . Method according to  claim 1 , whereby the epoxy system exhibits a yellowness index lower than 20 after an exposure of 200 hrs in a weather-ometer WOM Xenon CI-5000, according to SAE J 1960 test conditions. 
     
     
         5 . Method according to  claim 1 , whereby the epoxy resin is aliphatic having at least two epoxy groups per molecule or a mixture of at least two aliphatic epoxy resins having an average epoxide functionality of at least 1.5. 
     
     
         6 . Method according to  claim 5 , whereby the epoxy resin is a diglycidyl ether. 
     
     
         7 . Method according to  claim 1 , whereby the fiber fabric comprises carbon, glass, aramide or natural fibers. 
     
     
         8 . Composite material obtained by a method according to  claim 1 . 
     
     
         9 . Composite material according to  claim 8  comprising from 30% to 70% volume fraction of fibers based on the total volume of the composite material. 
     
     
         10 . Part of a car or racing car comprising a composite material according to  claim 8 . 
     
     
         11 . Concrete comprising a composite material according to  claim 8 .