Abstract: A molding compound is made by heat-softening, fusing and compressing strips of unidirectionally aligned filaments embedded in a thermosetting resin. The thermosetting resin is non-tacky at room temperature, which allows for easy handling, elimination of cold storage and the use of robotic manufacturing methods. Composites made by molding the molding compound have excellent, highly isotropic tensile properties.

Abstract: The present invention provides thermosetting resin pre-impregnated or infused fiber materials or prepregs comprising a thermosetting resin mixture and a fiber material component of a heat resistant fiber, such as carbon fiber, having an areal weight of from 500 to 3,000 g/m2 having a coating of from 0.5 to 4 phr of a latent, particulate curative or solid curative, preferably, dicyandiamide, wherein the prepregs are infused with a thermosetting resin mixture comprising (a) at least one liquid epoxy resin, and (b) a hardener and/or a catalyst, as well as methods of making the same. The prepregs of present invention enables the simple provision of lightweight composites having consistent resin cure throughout.

Abstract: The surface of a carbon fiber is electrochemically treated by a method to form nitrogen containing groups on the surface of the carbon fiber. The method comprises contacting a carbon fiber surface with an aqueous solution comprised of a non-cyclic aliphatic amine and water soluble inorganic hydroxide with said aqueous solution having a pH of at least 9. A positive electrical bias is then applied to the carbon fibers in the aqueous solution relative to another electrode in contact with the aqueous solution, wherein the positive electrical bias is at a voltage above the oxidation potential of water. The treated carbon fibers are useful for making epoxy reinforced carbon fiber composites.

Abstract: The present invention provides thermosetting resin pre-impregnated or infused fiber materials or prepregs comprising a thermosetting resin mixture and a fiber material component of a heat resistant fiber, such as carbon fiber, having an areal weight of from 500 to 3,000 g/m2 having a coating of from 0.5 to 4 phr of a latent, particulate curative or solid curative, preferably, dicyandiamide, wherein the prepregs are infused with a thermosetting resin mixture comprising (a) at least one liquid epoxy resin, and (b) a hardener and/or a catalyst, as well as methods of making the same. The prepregs of present invention enables the simple provision of lightweight composites having consistent resin cure throughout.

Abstract: The surface of a carbon fiber is electrochemically treated by a method to form nitrogen containing groups on the surface of the carbon fiber. The method comprises contacting a carbon fiber surface with an aqueous solution comprised of a non-cyclic aliphatic amine and water soluble inorganic hydroxide with said aqueous solution having a pH of at least 9. A positive electrical bias is then applied to the carbon fibers in the aqueous solution relative to another electrode in contact with the aqueous solution, wherein the positive electrical bias is at a voltage above the oxidation potential of water. The treated carbon fibers are useful for making epoxy reinforced carbon fiber composites.

Abstract: A molding compound is made by heat-softening, fusing and compressing strips of unidirectionally aligned filaments embedded in a thermosetting resin. The thermosetting resin is non-tacky at room temperature, which allows for easy handling, elimination of cold storage and the use of robotic manufacturing methods. Composites made by molding the molding compound have excellent, highly isotropic tensile properties.