Process for preparing copolymers of ethylene and unsaturated carboxylic acids or unsaturated carboxylic-acid esters or mixtures of these monomers

摘要

The copolymers comprise from 96 to 99.6 mol% of ethylene and from 0.4 to 4 mol% of a C3-C6-alkenecarboxylic acid or an ester of this acid having a total of up to 14 carbon atoms, or mixtures of these monomers, and are obtainable by polymerisation in a continuous tubular reactor at a pressure of from 500 to 5000 bar and at elevated temperature in the presence of initiators which decompose to form free radicals, by adding a mixture of said reaction components only at the inlet point of the tubular reactor, the temperature in a first reaction zone being limited to about 240 DEG C, further initiator being metered in at the beginning of a second reaction zone after the temperature has been reduced by from 5 to 20 DEG C, and the reaction being completed at temperatures of up to 300 DEG C.