To provide a manufacturing method of an ethylene-vinyl acetate copolymer emulsion which permits reduction of the unreacted vinyl acetate monomer concentration to at most 0.1 wt% and satisfactory attainment of the purposes of low VOC and low odor.
The manufacturing method of the ethylene-vinyl acetate copolymer emulsion comprises the first to third steps below: The first step is a step of emulsion polymerization using a redox catalyst comprising an oxidizing agent, a reducing agent and a transition metal compound to reduce the unreacted vinyl acetate monomer concentration down to less than 10 wt%; The second step is a step of purging unreacted ethylene to ordinary pressure after the completion of the first step and further depressurizing to remove ethylene to 4-26 KPa at 30-70°C; and The third step is a step of adding the oxidizing agent and/or the reducing agent to lower the unreacted vinyl acetate monomer concentration down to at most 0.1 wt%.
| WO/2019/126913 | A METHOD FOR PREPARING AQUEOUS COPOLYMER DISPERSIONS |
| JP2006273880 | EMULSIFYING AGENT FOR EMULSION POLYMERIZATION |
Toru Nakayama
Masayuki Enomoto