Curing agent for thermosetting epoxy resins, and a process for the preparation of insulation systems for electrical engineering

A multiple component thermosetting epoxy resin composition comprising

• (A) at least one epoxy resin, and
• (B) at least one curing agent comprising
• (a) at least one aromatic amine containing at least two amino groups, and
• (b) at least one clathrate compound obtained by reacting:
• 9,9-Bis(4-hydroxyphenyl)fluorene of formula
• as the host molecule and an imidazole or an imidazolium derivative as the guest molecule, wherein,
• R10, R11, R12, R13, R14 and R15 are each hydrogen,
• wherein the clathrate compound is present in the multiple component thermosetting epoxy resin composition in an amount ranging from 1 to 5 parts by weight based on 100 parts by weight of the at least one epoxy resin.

A process for the preparation of an insulation system for electrical engineering by a casting, potting, encapsulation, or an impregnation process, wherein a multiple component thermosetting epoxy resin composition is used, said epoxy resin composition comprising

• (A) at least one epoxy resin, and
• (B) at least one curing agent, comprising
• (a) at least one aromatic amine containing at least two amino groups, and
• (b) at least one clathrate compound obtained by reacting:
• 9,9-Bis(4-hydroxyphenyl)fluorene of formula
• as the host molecule and an imidazole or an imidazolium derivative as the guest molecule, wherein,
• R10, R11, R12, R13, R14 and R15 are each hydrogen.