TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The barrier film is metallic foil or inorganic metalized film. The metallic foil comprises aluminum foil, and copper foil or stainless foil. The inorganic metalized film comprises indium tin oxide, indium zirconium oxide, and silicon oxide (SiOx) or aluminum oxide (AlOx). Preferred Properties: The thickness of the metallic foil is 1-200 mu m. The thickness of the inorganic metalized film is 1-1000 nm. The thickness of the primer layer is 0.01-5 mu m.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The oxazoline group-containing compound is homopolymer of oxazoline group-containing monomer, and/or copolymer containing oxazoline group-containing monomer and at least one comonomer. The oxazoline group-containing monomer is of formula (I), preferably chosen from 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline and 2-isopropenyl-5- ethyl-2-oxazoline. The solvent contains acetone, methyl ethyl ketone, dimethylformamide and dimethylacetamide.R1-R4=H, alkyl, halo or phenyl (optionally substituted);andR5=acyclic hydrocarbyl having unsaturated bond.    TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The fluoropolymer is obtained by polymerizing at least one monomer chosen from vinylidene fluoride, vinyl fluoride, tetrafluoroethylene, hexafluoropropylene, chlorotrifluoroethylene, trifluoroethylene, hexafluoroisobutylene, (perfluorobutyl)ethyene, perfluoro(methylvinylether), perfluoro(ethylvinylether), perfluoro(propylvinylether), perfluoro(hexyl vinyl ether), perfluoro-2,2-dimethyl-1,3-dioxole and perfluoro-2-methylene-4- methyl-1,3-dioxolan. The coating layer further comprises pigment, filler, UV stabilizer, thermal stabilizer, dispersing agent or barrier particles. The multi layer film further has a basic material (substrate) in the barrier film bottom. The base material is single sheet, lamination sheet or co-extruded material of aluminum, iron, polyethylene terephthalate, polyethylene naphthalate or polybutylene terephthalate. A fluorinated polymer composition used in manufacture of multi layer film comprises fluoro polymer and solvent having boiling point of 200 degrees C or less. Preferred Properties: The weight-average molecular weight of the fluoropolymer is 50000-1000000. The melting point of the fluoropolymer is 80-175 degrees C. The thickness of the coating layer is 3-50 mu m. The thickness of the base material is 50-500 mu m.