| abstract |
The present invention relates to a process for the production of homopolymers of ethylene and copolymers of ethylene with olefins CH2=CHR, wherein R is an alkyl or aryl radical having a number of carbon atoms of from 1 to 10, and having a density greater than 0.86 g/cm3, comprising at least one (co)polymerization step in the gas phase, in the presence of an active catalyst obtained from a titanium compound supported on a magnesium halide in active form and an Al-alkyl compound. The process is characterized in that a small amount compared with the polymer is fed to the gas-phase reactor of a polyfunctional compound having at least two groups, the same or different, capable of reacting with the alkyl aluminum compound and capable of selectively inhibiting the reactivity of the polymer particle fines compared with the average granulometric size of the polymer present in the bed of a gas-phase polymerization reactor. |