IMPROVED PROCESS FOR RESIN TRANSFER MOLDING AND FORMULATIONS USEFUL TO PRACTICE THE PROCESS

摘要

An improved tackifier for making tackified substrates contains: (a) at least one epoxy resin, and (b) at least one curing agent for the epoxy resin, but (c) no catalytic amount of catalyst for the reaction between the epoxy resin and the curing agent. The tackified substrates are used to make composites by: (1) placing one or more of the tackified substrates in a mold; (2) injecting into the mold a matrix resin formulation which is chemically-similar to the tackifier, except that it contains a catalytic amount of catalyst for the reaction between the epoxy resin and the curing agent; and (3) curing the matrix resin formulation. The tackifiers are more storage-stable than similar tackifiers which contain catalyst, and the resulting composites have and/or retain physical properties better than composites made using tackifiers without curing agent.