The invention discloses a completely-biodegradable pre-
coating film. The completely-biodegradable pre-
coating film comprises a substrate, a middle layer and an
adhesive layer, wherein the middle layer is positioned between the substrate and the
adhesive layer; the substrate is prepared from the following materials in parts by weight: 1 to 10 parts of
polyethylene terephthalate, 5 to 10 parts of biaxially oriented
polypropylene thin film, 10 to 15 part of biaxially oriented
polyester thin film, 1 to 5 parts of biaxially oriented nylon thin film and 1 to 4 parts of
terpene resin; the middle layer is prepared from the following materials in parts by weight: 1 to 10 parts of
polyethylene wax and 5 to 15 parts of
elastomer; the
adhesive layer is prepared from the following materials in parts by weight: 5 to 10 parts of
ethylene-
vinyl acetate resin, 1 to 5 parts of hydrogenated
petroleum resin, 3 to 6 parts of hydrogenated
rosin glycerol ester, 1 to 10 parts of
petroleum resin and 1 to 10 parts of waterborne
polyurethane. According to the completely-biodegradable pre-
coating film disclosed by the invention, materials used by the completely-biodegradable pre-coating film have good
biocompatibility, good biodegradability and good
hot working performance of plastics, the completely-biodegradable pre-coating film is the first choice of biodegradable packaging materials, and the completely-biodegradable pre-coating film is better in biodegradability, quicker in degradation speed and more complete in degradation.