| 摘要 |
PURPOSE:To obtain the titled copolymer for use in food packaging, etc., by high-pressure radical polymerization between ethylene and a polar comonomer, making the resultant reaction mixture put under reduced pressure to add specific amount of ethylene to the system followed by separation and purification of the unreacted monomer to return it to the polymerizer. CONSTITUTION:Ethylene 1 and a polar comonomer 2 are put in a high-pressure state by compressors 3 and 4 to feed them to polymerizer 5 to carry out high- pressure radical polymerization. The resulting reaction mixture is put at a reduced pressure state by reducing valve 6, and such an amount of ethylene as to be >=2.0 in the weight ratio; ethylene/copolymer is newly fed to the system in a molten state of the copolymer under a pressure 1-500kg/cm<2> to come into contact with the copolymer. The reaction mixture is then fed to separator 7 to separate the unreacted monomer. Following that, the ethylene newly brought into contact with the copolymer and said unreacted monomer separated are both purified by purification process 12, being returned to the polymerizer 5, thus obtaining the objective copolymer. |
