摘要 |
<p>The application to an object, as cathode, of a composite coating comprising a polyfluorocarbon resin and a metal and opt. particles of a different material, the ave. size of the resin particles being 10 mu and the latter being kept in suspension at a concn. of 3-1 50 g/1 bath soln. in the presence of a cationic fluorocarbon surfactant and a non-ionic surfactant, is disclosed. In this process (a) the non-ionic surfactant is a fluorocarbon cpd; (b) the mol. ratio of cationic surfactant to non-ionic surfactant is 25:1 1:3.5; (c) the total amt. of surfactive fluorocarbon cpds. is not >=3 x 10-3, esp. 6.10-3 - 12.10-3 m moles/m2 of surface of the resin particles. For coating Ni and also Pb, Cu, Fe, Zn, Ag, Au, etc. coming in contact with corrosive liquids, e.g. as in cooking utensils, industrial pipe systems, heat exchangers, spinning plates requiring frequent cleaning, etc. The resin i.e. PTFE is not agglomerated but distributed very uniformly in the coating.</p> |