was used as a fouling prevention agent the polymerization conditions and the results are presented in the following table ______________________________________fouling prevention agent 0 0 015 0 030 0g g catalystcatalyst activity 5 6 5 8 5 1 4 8kg polymer g catmelt index mfr 21 hlmi 18 15 17 18 g 10 min reactor temperature u00b0 c 105 0 105 0 105 0 105 0reactor pressure bar 40 40 40 40______________________________________ the addition of the fouling prevention agent did not affect the melt index of the polymer nor the activity of the catalyst a copolymer of ethylene and 1 hexene was produced on an industrial scale in a loop reactor of 86 m 3 by using a chromium acetonate catalyst supported on a silica carrier asa 3 was used as a fouling prevention agent during the polymerization the additive was gradually replaced with the additive tolad 511 according to the invention the electrostatic potential of the polymer powder produced otherwise in prevailing constant conditions dropped from the value of 4 3 to the value of 0 9 while the catalyst activity increased from the value of 2 9 to the value of 3 6 kg g catalyst this demonstrates the efficiency of the additive according to the invention and that it has no poisoning action on catalysts the polymerization of example 2 was repeated by using the agent tolad 511 of the invention as a fouling prevention agent the additive of the invention was suddenly replaced with the other additive asa 3 the catalyst activity dropped dramatically and almost extinguished the polymerization reaction a copolymer of ethylene and 1 hexene was produced on an industrial scale in a.