Hexcel Corporation

Richard J Moulton

John D Neuner

Richard B Goodrich

A compound prepared by reacting at least one aromatic or aliphatic polyamine compound having at least two amine groups, which are separated by no more than one carbon atom, with at least one carbonyl-containing compound selected from the group consisting of aldehydes and ketones, wherein said polyamine compound is selected from:

Perimidene and benzimidazole derivatives useful in curable compositions

A curable composition, and composites comprising (A) an epoxy resin and (B) a heterocyclic compound prepared by reacting at least one aromatic or aliphatic polyamine compound having at least two amine groups, which are separated by no more than one carbon atom, with at least one carbonyl-containing compound selected from the group consisting of aldehydes and ketones.

Heterocyclic multifunctional amine adducts and curable compositions

A prepreg having substantially no excess resin while at the same time having an aggressive tack. Small discrete amounts of additional resin are selectively applied to a surface of the prepreg sheets in a regular array. The resin is applied at a sufficient viscosity that it does not sink into the prepreg fabric. The additional resin typically covers less than 25% of the surface and constitutes between 0.1% and 3% of the prepreg weight. The additional resin may be applied by a gravure roller having a surface etched with an appropriate array of indentations. A doctor blade partially defines a reservoir of resin in contact with a portion of the gravure roller and wipes the surface, thereby leaving resin only in the indentations. The doctor blade may be oscillated parallel to the roller axis to prevent accumulations of short fibers from impairing the wiping action.

Prepreg material having increased surface tack

A method for supplying a prepreg having substantially no excess resin while at the same time having an aggressive tack. Small discrete amounts of additional resin are selectively applied to a surface of the prepreg sheets in a regular array. The resin is applied at a sufficient viscosity that it does not sink into the prepreg fabric. The additional resin typically covers less than 25% of the surface and constitutes between 0.1% and 3% of the prepreg weight. The additional resin may be applied by a gravure roller having a surface etched with an appropriate array of indentations. A doctor blade partially defines a reservoir of resin in contact with a portion of the gravure roller and wipes the surface, thereby leaving resin only in the indentations. The doctor blade may be oscillated parallel to the roller axis to prevent accumulations of short fibers from impairing the wiping action.

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Concord, CA, United States of America

Richard J Moulton