Preparation Of Er-doped Composite Ceramic Conductive Fillers And Conductive Coatings

In order to solve the invalidation problem of traditional metal conductive additives caused by oxidation and corrosion, conductive ceramic powders as f illers were adopted to prepare the conductive coatings. The conductive ceramic powders, with properties of anti-oxidation, corrosion resistance and thermal stability, were obtained via the gaseous penetration of Er to Ba TiO₃ powders and Maifan Stone, respectively.Firstly, the gaseous penetration of Er to Ba TiO₃ ceramic powders and gel precursors was adopted, and the results show that the gaseous penetration owns the ability to dramatically decrease the resistivity of Ba TiO₃ system, and the materials obtained by the Er-penetration to Ba TiO₃ ceramic powders exhibited better conductive performance, with resistivity decreased from 4.30×109 Ω?m to 2.43 Ω?m. Then, the Er-penetration to Maifan stone was carried out, and process condition of this penetration was determined, changes in constitution, structure and morphology of the modified materials were also investigated. The results indicate that the modified Maifan materials obtained under the optimum conditions with the penetration temperature of 500 ℃, Er-concentration of 5.0%, the penetration temperature of 5h and the penetration height of 9cm, exhibit ed the lowest resistivity（93.2 Ω?m）. Compared with the unmodified Maifan Stone, particles of the Er-penetrated materials were more refined, and in this modified materials, the component of Ca CO3 disappeared, the C-element content increased and O-element content decreased.Based on the preparation of conductive Ba TiO₃ and Maifan powders modified by rare-earth Er, conductive coatings were prepared by using them as conductive fillers and epoxy resin as the matrix, and the effects of the dosage of conductive fillers, diluent, curing agent on the performance were investigated. An appropriate composition of the coating was obtained, which contained 5% of acetone as diluent, 4% of KH550 as coupling agent, 2% of 2-ethyl-4-methylimidazole as accelerator, 12.5% of triethanolamine as curing agent, 55% of conductive powders. The cured coating prepared in this condition exhibited a smooth surface, and the hardness reached 5H. With resistivity of 4.86×107 Ω, this kind of conductive coating can be used as an antistatic coating.