BENARD CONVECTION ZNO RESIN LACQUER COATING - A NEW APPROACH TO ELECTROSTATIC DISSIPATIVE COATING/

Coating of ZnO/resin composite films has been investigated by optical microscopy, scanning electron microscopy and electromeasurement. Poly( vinyl chloride)/poly(methyl methacrylate) lacquer mixed with either ne edle like (N-) or tetrapod-like (T-) ZnO particles is spread in a 200 mu m thick layer on a glass sheet. Benard convection occurs in the coa ting. N-ZnO particles flow along the convection streams, and are then dispersively fixed within the cells but not at the boundaries. On the other hand, T-ZnO particles aggregate in rings along the boundaries of Benard cells. While the lacquer dries and solidifies, the rings of th e T-ZnO particles are broken down into two or three pieces, and form a network structure by meeting and parting among them. The T-ZnO/resin composite films have a surface resistivity of 10(6) Omega/square or le ss, and provide a good electrostatic dissipative coating. (C) 1997 Els evier Science S.A.