Lactam melts having increased viscosity and their use

Abstract

The invention relates to lactam mixtures which give lactam melts having increased viscosity, to their production and to their use, preferably in the activated anionic polymerization of lactams (to cast polyamides). According to the invention, certain unsaturated aromatic vinyl compound/diene block copolymers (B) which dissolve in the lactam melt are added to the lactam (melt)s (A) in quantities of 1 to 15% by weight, a component (C) which is compatible with the diene block copolymers (B) and which dissolves completely or partly in the lactam melt optionally being added as an additional component. The block copolymers (B) used contain 10 to 85% by weight aromatic vinyl units and 15 to 90% by weight diene units. The block copolymers (B) may even be partly hydrogenated, epoxidized or grafted. The preferred lactam is .epsilon.-caprolactam. Lactam melts of increased viscosity are particularly suitable for taking up reinforcing materials and fillers (D) and for the production of filled cast polyamides. The invention also relates to the use of lactam melts thus thickened, more particularly lactam melts containing fillers/reinforcing materials, in a process for the production of polyamides and also to corresponding polyamide moldings, more particularly by the anionically activated casting process.