Abstract: A composite material (1) comprising at least one prepreg (3), said prepreg comprising at least one polymeric resin and optionally at least one fibrous reinforcement; and a conducting ink (2) applied to at least one surface of said prepreg (3); where the conducting ink (2) has a surface tension lower than the surface energy of the at least one surface of said prepreg (3) to which the ink (2) is applied.

Abstract: A curable resin with at least one electrically conductive metal region on its surface formed by depositing on the surface a composition comprising activator, contacting the activator with a solution of a reducing agent and a solution of a metal ion, the reducing agent and metal ion undergoing chemical reaction activated by the activator to form an electrically conductive metal region on the surface, and method of forming is provided.

Abstract: A composite material (1) comprising at least one prepreg (3), said prepreg comprising at least one polymeric resin and optionally at least one fibrous reinforcement; and a conducting ink (2) applied to at least one surface of said prepreg (3); where the conducting ink (2) has a surface tension lower than the surface energy of the at least one surface of said prepreg (3) to which the ink (2) is applied.

Abstract: Expanded cellular structures are formed from dense nonporous cellulose paper with an air permeance of less than 30 ml/min which cellular structure is provided with a shape retention of at least 90%. The shape stability is obtained by forming the cellular structure, spraying with an aqueous liquid and heating, the amount of liquid, time and temperature of heating being selected and sufficient to provide the desired shape retention. The minimum amount of water is at least 30 weight % of dry paper more usually at least 75% with minimum heating of 1 minute at 100° C.

Abstract: An improved honeycomb structure formed from a non-woven sheet material coated with a resin which contains particles of a polymeric material. The inclusion of solid polymeric particles in the resin coating was found to increase the strength and stiffness of the honeycomb without degrading compressive properties. Composite panels are also disclosed where the improved honeycomb structure is combined with one or more facing sheets.

Abstract: Curing agents for epoxy resins are provided in which an imidazole is substituted on the nitrogen atom by a long chain group. This provides greater latexing (stability) at ambient temperatures without adversely affecting curing properties at temperatures of 50.degree. C. upwards. Those components in which the chain is substituted by a hydroxy group on the 2 position are particularly preferred and are novel compounds.