Method for preparing multifunctional environmental friendly coating for waterproof and oil-proof food packaging papers by one step method and application thereof

A waterproof and oil-proof food packaging paper, comprising a paper body, wherein one side of the paper body is coated with a waterproof and oil-proof oil layer;

• the waterproof and oil-proof oil layer is obtained by coating the multifunctional environmentally friendly coating for waterproof and oil-proof food packaging papers prepared by a one-step method, then drying it;
• a preparation method of the multifunctional environmentally friendly coating for waterproof and oil-proof food packaging paper is as follows:
• adding a chitosan to an acetic acid solution according to a ratio, heating and stirring until clear, to obtain an acidic chitosan solution;
• then, adding a palm wax to the acidic chitosan solution according to a ratio, and heating a resulting mixture to 90° C. with a constant temperature and a high-speed stirring for emulsification for 10 minutes;
• after the emulsification is completed, an obtained emulsion is quickly cooled to a room temperature in a cold water to obtain an environmentally friendly coating for waterproof and oil-proof food packaging papers;
• the mass fraction of anhydrous acetic acid in the acetic acid solution is 1-3 wt %;
• the mass ratio of chitosan to anhydrous acetic acid is 1:1;
• the mass ratio of palm wax to chitosan is 5:1;
• a drying temperature is 90-100° C., and a drying time is 5-15 minutes;
• a quantification of the waterproof and oil-proof layer is 6.5 g/m2.