METHOD FOR PREPARING POLYETHYLENE Russian patent published in 2005 - IPC

FIELD: organic chemistry, polymers, chemical technology.

SUBSTANCE: invention relates to technology for producing polyethylene by method of radical polymerization in mass under high pressure in the single-zone autoclave reactor. Invention describes a method for preparing polyethylene involving feeding ethylene in the single-zone reactor with stirring device and its polymerization in mass under pressure 140-230 MPa and temperature 210-265°C in the presence of chain-transferring agent - isopropyl alcohol, initiation of polymerization reaction with organic peroxides feeding as solutions in organic solvent at top and bottom parts of reactor and the following two-step separation of synthesized polyethylene from unreacted ethylene in systems of recycles of high and low pressures. Method involves using a mixture of isopropyl alcohol with glycols as the chain-transferring agent that comprise 2-5 carbon atoms in molecule, or with their derivatives - polyglycols with molecular mass 3 000 Da, not above, in the mass ratio isopropyl alcohol and glycol or polyglycol = 1:(0.05-0.25), respectively. Method provides improving strength and optical properties of synthesized polymer, reducing mass part (less 0.65%) extractable substances in it in realization the process of ethylene polymerization in the single-zone autoclave reactor, reducing intensity of gas evolving in processing the synthesized polyethylene and increase of elasticity of film made of polyethylene. Invention can be used in chemical and petroleum chemistry industry.

EFFECT: improved method for producing.

5 cl, 1 tbl, 21 ex