Graft polymers, their preparation and their use as pour point depressants and flow improvers for crude oils, residual oils and middle distillates

摘要

The invention relates to graft polymers comprising from 20 to 99.9% by weight of an ethylene copolymer (base polymer) and from 0.1 to 80% by weight of a graft component. The base polymer contains from 30 to 95% by weight of ethylene and from 5 to 70% by weight of vinyl esters of saturated, aliphatic C2- to C18-monocarboxylic acids or from 4 to 50% by weight of vinyl esters of saturated, aliphatic C2- to C18-monocarboxylic acids and from 1 to 20% by weight of linear or branched C3- to C18-monoolefins. Graft components are N-substituted alpha,beta-unsaturated dicarboximides and/or dicarboxamides and/or dicarboxylic acid monoamides and/or ammonium salts of the monoamides. The graft polymers are used to improve the flow properties of paraffin-containing mineral oils and mineral oil distillates.