▎ 摘　　要

NOVELTY - Wet and corrosion resistant coating comprises PTC ceramic heater subjected for once spraying treatment, deposition treatment, secondary spray coating and baking sequentially. USE - Wet and corrosion resistant coating is used for positive temperature coefficient (PTC) ceramic heater. Can also be used for other types of ceramic heater. ADVANTAGE - The coating has the effects of high temperature resistance, heat conduction, moisture resistance and corrosion resistance. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparation method of wet and corrosion resistant coating comprising: (1) spraying PTC ceramic heater with 0.05 times of nickel nitrate solution, baking at 45°C for 55-70 minutes to obtain the pre-processing heater; (2) placing the pre-processing heater in the radio frequency plasma device, vacuumizing to 1 × 10-3to 5 × 10-3Pa, under the nitrogen atmosphere, heating to 500 °C, thermal insulating for 20-30 minutes, introducing hydrogen to the volume ratio of hydrogen and nitrogen of 1: 4, reacting for 50-62 minutes, introducing methane to the pressure of 25-30 Pa, reacting for 30 -46 minutes, cooling to room temperature in the nitrogen atmosphere to obtain the carbon nano-tube heater; (3) mixing heat-resistant resin, NW-5, leveling agent DC51, benzoin, modified nano-fiber, diphenyl sulfone, anhydrous potassium carbonate, anhydrous sodium carbonate, polytetrafluoroethylene to the mass ratio of 1: 0.2: 0.01: 0.007: 0.2: 3: 0.02: 0.1: 0.008 to 1: 0.3: 0.02: 0.008: 0.4: 3: 0.03: 0.1: 0.02, stirring uniformly, extruding at 120-140°C, tableting, grinding for 8-16 minutes at 5000 revolutions/minute (rpm) to obtain powder coating; placing the carbon nano-tube heater into the plasma chamber, under the carbon dioxide atmosphere, the voltage is 9.5kV, the frequency is 9.8kHz processing discharging power for 100-130 seconds at 12.3W, spraying powder coating to the carbon nano-tube heater until the thickness is 0.1-0.3mm, raising the temperature to 220-290 °C, after baking for 56-72 minutes, raising the temperature to 300-320°C, baking for 2-4 hours, obtaining the wet and corrosion resistant coating for PTC ceramic heater.