Fire-retardant composite materials

Abstract

A prepreg for the manufacture of a fibre-reinforced composite material, the prepreg including: i. an epoxy-resin matrix including: a. at least one non-halogenated epoxide-containing resin which has been chemically modified with at least one of a nitrogen- and/or phosphorous-containing molecule which has been chemically reacted with the epoxide-containing molecule; b. at least one toughening additive comprising an elastomeric or thermoplastic material chemically reacted with the at least one epoxide-containing resin; c. at least one mineral filler to provide fire-retardancy; and d. at least one catalyst for curing the epoxide-containing resin; and ii. a fibrous reinforcement at least partially impregnated by the epoxy resin matrix.

1 . A prepreg for the manufacture of a fibre-reinforced composite material, the prepreg comprising:
 i. an epoxy-resin matrix comprising:   a. at least one non-halogenated epoxide-containing resin which has been chemically modified with at least one of a nitrogen- and/or phosphorous-containing molecule which has been chemically reacted with the epoxide-containing molecule;   b. at least one toughening additive comprising an elastomeric or thermoplastic material chemically reacted with the at least one epoxide-containing resin;   c. at least one mineral filler to provide fire-retardancy; and   d. at least one catalyst for curing the epoxide-containing resin; and   ii. a fibrous reinforcement at least partially impregnated by the epoxy resin matrix.   
     
     
         2 . A prepreg according to  claim 1  wherein the at least one toughening additive comprises the combination of the elastomeric material chemically reacted with the at least one epoxide-containing resin and the thermoplastic material chemically reacted with the at least one epoxide-containing resin. 
     
     
         3 . A prepreg according to  claim 1  wherein the epoxide-containing molecule has been chemically reacted with a phosphinic acid derivative. 
     
     
         4 . A prepreg according to  claim 3  wherein the phosphinic acid derivative comprises dihydro-oxa-phospha-phenanthrene-oxide (DOPO). 
     
     
         5 . A prepreg according to  claim 1  wherein the epoxide-containing resin comprises from 2 to 10 wt % added phosphorous, based on the weight of the phosphorous-containing epoxide-containing resin. 
     
     
         6 . A prepreg according to  claim 1  wherein the epoxide-containing resin comprising phosphorous, comprises from 24 to 44 wt %, based on the weight of the resin matrix. 
     
     
         7 . A prepreg according to  claim 1  wherein the at least one toughening additive comprises from 3 to 30 wt %, based on the weight of the resin matrix. 
     
     
         8 . A prepreg according to  claim 1  wherein the at least one toughening additive comprises, as the elastomeric material, a difunctional-terminated rubber reacted with the epoxide groups of the at least one epoxide-containing resin. 
     
     
         9 . A prepreg according to  claim 8  wherein the difunctional-terminated rubber comprises from 1 to 15 wt %, based on the weight of the resin matrix. 
     
     
         10 . A prepreg according to  claim 8  wherein the difunctional-terminated rubber is a carboxyl-terminated rubber, preferably a carboxyl-terminated butadiene acrylonitrile rubber. 
     
     
         11 . A prepreg according to  claim 1  wherein the at least one toughening additive comprises, as the thermoplastic material, a polyhydroxyl ether reacted with the epoxide groups of the at least one epoxide-containing resin. 
     
     
         12 . A prepreg according to  claim 10  wherein the polyhydroxyl ether comprises from 2 to 15 wt %, based on the weight of the resin matrix. 
     
     
         13 . A prepreg according to  claim 1  wherein the at least one toughening additive further comprises a rubber dispersion throughout the resin matrix. 
     
     
         14 . A prepreg according to  claim 13  wherein the rubber dispersion comprises from 3 to 15 wt %, based on the weight of the resin matrix. 
     
     
         15 . A prepreg according to  claim 1  wherein the at least one toughening additive comprises the combination of a difunctional-terminated rubber chemically reacted with the epoxide groups of the at least one epoxide-containing resin, a polyhydroxyl ether chemically reacted with the epoxide groups of the at least one epoxide-containing resin, and a rubber dispersion throughout the resin matrix. 
     
     
         16 . A prepreg according to  claim 1  wherein the at least one mineral filler comprises at least one fire-retardant mineral filler and at least one smoke-suppressant mineral filler. 
     
     
         17 . A prepreg according to  claim 16  wherein the at least one fire-retardant mineral filler comprises ammonium polyphosphate. 
     
     
         18 . A prepreg according to  claim 16  wherein the at least one fire-retardant mineral is present in an amount of from 15 to 30 wt % based on the weight of the resin matrix. 
     
     
         19 . A prepreg according to  claim 16  wherein the at least one smoke-suppressant mineral filler comprises zinc borate. 
     
     
         20 . A prepreg according to  claim 19  wherein the at least one smoke-suppressant mineral is present in an amount of from 1 to 10 wt % based on the weight of the resin matrix. 
     
     
         21 . A prepreg according to  claim 1  wherein the at least one catalyst comprises plural catalysts, each having a respective curing temperature range, and the plural temperature ranges overlap to provide a broader cumulative curing temperature range for the epoxide-containing resin. 
     
     
         22 . A prepreg according to  claim 1  wherein the at least one catalyst for curing the epoxide-containing resin comprises dicyanamide. 
     
     
         23 . A prepreg according to  claim 21  wherein the at least one catalyst for curing the epoxide-containing resin further comprises a catalyst for reducing the curing temperature of the dicyanamide. 
     
     
         24 . A prepreg according to  claim 21  wherein the at least one catalyst for curing the epoxide-containing resin further comprises an imidazole-based curing agent. 
     
     
         25 . A prepreg according to  claim 1  further comprising at least one anti-settling agent for the at least one mineral filler. 
     
     
         26 . A prepreg according to  claim 25  wherein the at least one anti-settling agent comprises amorphous silicon dioxide. 
     
     
         27 . A prepreg according to  claim 25  wherein the at least one anti-settling agent is present in an amount of from 0.1 to 1.5 wt % based on the weight of the resin matrix. 
     
     
         28 . A fibre-reinforced composite material produced from the prepreg of  claim 1 . 
     
     
         29 . A fibre-reinforced composite material according to  claim 28  adhered by the epoxy resin matrix to a core material, optionally a honeycomb core material.