NOVELTY - Fluorocarbon coating is prepared by sequentially adding 1st polyester polyol, isocyanate curing agent, and 1st anhydrous diluent in reactor, heating, adding tin catalyst, reacting, adding fluorocarbon resin to reaction system, mixing, reacting to obtain flurorocarbon polyurethane prepolymer, high speed mixing, cooling, adding nanoscale inorganic filler, hydrolytic stabilizer, dispersant, leveling agent, 2nd tin catalyst, initiator, hydroxyethyl methacrylate ester, and 2nd anhydrous diluent, high speed mixing to obtain part (A), and storing in dry airtight container.    USE - Preparation of fluorocarbon coating for base film coating of solar battery back plate, such as polyethylene terephthalate base film, poly(butylene terephthalate) base film, polyethylene terephthalate and polyethylene naphthalate base film, polybutylene terephthalate and polyethylene naphthalate base film, polyundecalactam bgase film, polydodecalactam base film, polypropylene base film, polyethylene base film, or tempered glass (all claimed) and double-coated backplane.    ADVANTAGE - Coating has interpenetrating network structure, excellent hardness and chemical, weather, water, salt spray, aging, and wear resistance.    DETAILED DESCRIPTION - Fluorocarbon coating is prepared by sequentially adding 1st polyester polyol, isocyanate curing agent, and 1st anhydrous diluent in reactor, heating to 75-85 degrees C while stirring, adding tin catalyst, reacting for 2-3 hours in which molar ratio of hydroxyl (OH) of polyester polyol and isocyanate (NCO) of isocyanate curing agent is 1:3-4 and amount of isocyanate curing agent is equal to 1st anhydrous diluent, and tin catalyst is 0.01-0.1 mass% of total mass, adding fluorocarbon resin to reaction system, mixing, reacting for 2-3 hours to obtain fluorocarbon polyurethane prepolymer in which molar ratio of OH of fluorocarbon resin and OH of polyester polyol is 7-9:1, high speed mixing prepolymer, cooling to room temperature, adding 10-15 mass% nanoscale inorganic filler, 3-5 mass% hydrolytic stabilizer, 1-5 mass% dispersant, 0.1-1 mass% leveling agent, 0.1-1 mass% 2nd tin catalyst, 0.01-0.1 mass% initiator, 5-10 mass% hydroxyethyl methacrylate ester, and 50-100 mass% 2nd anhydrous diluent, high speed mixing at 3000 r/minute for 1-2 hours to obtain part (A), storing in dry airtight container, sequentially adding hydroxyl acrylate resin, isocyanate curing agent, and 3rd anhydrous diluent to reactor, slowly heating to 75-85 degrees C while stirring, adding 3rd tin catalyst, continuously reacting for 2-3 hours, slowly cooling to room temperature to obtain part (B) in which molar ratio of OH of hydroxyl acrylate resin and NCO of isocyanate curing agent is 1:3-4, amount of isocyanate curing agent is equal to 3rd anhydrous solvent, and 3rd tin catalyst is 0.01-0.1 mass% with respect to total mass of hydroxyl acrylate resin, isocyanate curing agent, and 3rd anhydrous diluent, mixing part (A) and part (B) with mass ratio of 1-2:1, uniformly coating material adhesively on surface with thickness of 20-25 mu m, and curing at 120-175 degrees C for 1-5 minutes. An INDEPENDENT CLAIM is included for application of fluorocarbon coating for base film coating of solar battery back plate in which base film is polyethylene terephthalate base film, poly(butylene terephthalate) base film, polyethylene terephthalate and polyethylene naphthalate base film, polybutylene terephthalate and polyethylene naphthalate base film, polyundecalactam base film, polydodecalactam base film, polypropylene base film, polyethylene base film, or tempered glass.