Method for preparing polyvinyl alcohol and polyvinyl acetate latex by use of the bottom residue from vinyl acetate production process

A method for preparing a polyvinyl acetate latex, comprising:

• i. distilling a kettle bottom residue of vinyl acetate to obtain a crude acetic acid and a distillation residue;
• ii. washing the distillation residue with water under boiling conditions several times until a discharged washing water has a pH of 4-6 to obtain a washing residue containing polyvinyl acetate;
• iii. dissolving a first portion of the washing residue into a first solvent to obtain a first polyvinyl acetate solution;
• iv. subjecting the first polyvinyl acetate solution to saponification with an alkali aqueous solution to obtain a polyvinyl alcohol solution;
• v. dissolving a second portion of the washing residue into a second solvent to obtain a second polyvinyl acetate solution;
• and
• vi. dispersing the second polyvinyl acetate solution into the polyvinyl alcohol solution, and optionally recovering the solvent to obtain a polyvinyl acetate latex;
• or adding the second polyvinyl acetate solution into an emulsion reaction system containing the polyvinyl alcohol solution, an emulsifier, vinyl acetate and an initiator and reacting, optionally recovering vinyl acetate, to obtain a polyvinyl acetate latex.