Novel polyolefin waxes and aqueous polishing emulsions thereof

In a process for preparing a metal-containing polyolefin wax comprising melting a reaction product of a starting polyolefin wax having an average molecular weight of 400 - 1,500 and an ethylenically unsaturated dibasic acid having 4 - 5 carbon atoms or anhydride thereof and reacting the melted reaction product with a metal compound in which the metal is selected from the metals of Group II of the Periodic Table, to produce an acid-modified polyolefin wax, the improvement which comprises reacting said acid-modified polyolefin wax and Group II metal compound at 100.degree.-200.degree. C in the presence of water or a volatile acid as a catalyst thereby to obtain the metal-containing polyolefin wax.