Abstract: The invention relates to a multilayer prepreg comprising a first and a second fiber prepreg, one or two micaceous prepregs and B staged thermosetting resin, which may be different for each layer or identical. The micaceous prepregs are positioned on the top (outside) of the fiber prepregs. There may be plurality of further fiber prepregs. The micaceous prepregs preferably comprise mica flakes in the form of a mica paper. The use of such prepreg as surfacing layer at the top of a composite material or near the top of a composite material can determine an improvement in burn-through and fire retardancy performance of composite materials. It is also disclosed a cured composite panel, such as an aircraft part, obtainable by curing the multilayer prepreg to a C stage.

Abstract: A curable composition comprising: i) a glycidyl ether of a novolac, comprising or consisting of moieties having the formula (I), wherein —Ra is either always hydrogen or always methyl; —B is either always *—CH2-** or always formula (A); —a fraction of 0.8 to 0.99 of the Y moieties are essentially —O-glycidyl, this fraction being designated as x, and the remainder of the Y moieties, this fraction being designated as (1-x), are divalent bridging spacers of the structure *—O—CH2—CH(OH)—CH2—O—** connecting two moieties according to above formula (I); and—n is a number in the range of 0.1 to 3.0; and wherein said novolac glycidyl ether has an epoxy equivalent weight FEW in the range of 160 to 270 g/eq. and the average number of epoxy groups per molecule of novolac glycidyl ether (I), designated as f, is in the range of 2.1 to 5.0; ii) dicyandiamide; and iii) an urea derivative of the formula (II). This composition is stable upon storage at room temperature and fire-retardant.