| abstract |
A polyester fiber composite material useful for reinforcing rubber articles, comprises a polyester fiber substrate impregnated with an impregnating composition containing (A) a polyepoxide compound, (B) a rubber latex, (C) a resorcin-formaldehyde prepolymer and a water-soluble polyurethane compound of the formula (I): <IMAGE> (I) wherein A=a tri-hepta valent radical, X=a monovalent residue of blocking compound capable of dissociating from the compound (c) at an elevated temperature, Y=a monovalent residue of an aminosulfonic acid having 2 to 6 carbon atoms or aminocarboxylic acid having 1 to 6 carbon atoms, n=5-30, m=1-5, l=1-5 and l+m=2-6, the impregnating composition having been heat-treated on the substrate at least once at a temperature of 120 DEG C. to the melting point of the polyester fiber. |