Novel Hole Transport Materials and their Application for Electrophotography

摘要

A family of novel dimeric carbazole hydrazones hole transport materials was developed and evaluated for electrophotography. The general structure of the family (shown below) enables us to make several derivatives with different R group substituents on the carbazole and different x linkage groups that connects the two hydrazone moieties. The synthesis of the hole transport materials was achieved via 4-step reaction sequence: N-alkylation of the carbazole, Vilsmeier reaction followed by reaction with phenylhydrazine. In the final step, the dimer is formed. The total yield of the final product from all 4 steps is ～ 46%. The H-NMR spectra of all intermediates along with the final product is in agreement with their structures. The hole drift mobility determined by Time of Flight measurement (TOF), ionization potential and electrophotographic cycling results of these hole transport material will be described.