| 摘要 |
PURPOSE:To obtain the titled copolymer excellent in pour point depressing effect and low-temperature filtrability, in high yields, by copolymerizing ethylene with vinyl acetate in the presence of a mixed solvent consisting of tert-butyl alcohol and an aliphatic or alicyclic hydrocarbon or an ester. CONSTITUTION:An ethylene/vinyl acetate copolymer is obtained by charging an autoclave with a mixed solvent consisting of 0-60wt% aliphatic hydrocarbon, alicyclic hydrocarbon or a fatty acid ester of an aliphatic alcohol (e.g., n- heptane, cyclopentane, methyl acetate) and 100-40wt% tert-butyl alcohol and vinyl acetate, pressurizing the autoclave with ethylene and copolymerizing the reaction mixture at 130-180 deg.C. The produced copolymer is added to an oil such as light naphtha, heavy naphtha or crude oil, in an amount of 50-3,000ppm to prevent the viscosity increase of oil with a termperature decrease and the deposition of paraffin in oil. |
