Method for emulsion polymerizing olefins

A process for the preparation of an aqueous polymer dispersion comprising reacting at least one olefin in the presence of at least one polymerization catalyst and one emulsifier in an aqueous medium, wherein the polymerization catalyst is produced in an in situ reaction by reacting the ligand compound 2,6-dichloro-para-benzoquinone (Ia) and/or 2,3,6-trichloro-para-benzoquinone (Ib)

• with a phosphine compound PR3′, where R′ is hydrogen, C1-C12-alkyl, C3-C12-cycloalkyl, C7-C15-aralkyl or C6-C14-aryl,
• or with a diphosphine compound R2′P-G-PR2′, where R′ has the same meanings as in the phosphine compounds PR3′ and G is a divalent radical, such as C1-C12-alkylene, C3-C12-cycloalkylene, C7-C15-aralkylene or C6-C14-arylene,
• and with a metal compound of the formula M(L2)2 or M(L2)2(L1)z,
• where:
• M is a transition metal of groups 7 to 10 of the Periodic Table of the Elements,
• L1 are phosphanes (R1)xPH3-x, or amines (R1)xNH3-x having identical or different radicals R1, diamines, ethers (R1)2O, water, alcohols (R1)OH, pyridine, pyridine derivatives of the formula C5H5-x,(R1)xN, carbon monoxide, C1-C12-alkylnitriles, C6-C14-arylnitriles or ethylenically unsaturated double bond systems, where x is an integer from 0 to 3,
• R1 is hydrogen or C1-C20-alkyl, which in turn may be substituted by O(C1-C6-alkyl) or N(C1-C6-alkyl)2, or is C3-C12-cycloalkyl, C7-C15-aralkyl or C6-C14-aryl,
• L2 are halide ions, R2xNH3-x, where x is an integer from 0 to 3 and R2 is C1-C12-alkyl, and furthermore C1-C6-alkyl anions, allyl anions, benzyl anions or aryl anions, where L1 and L2 may be linked to one another by one or more covalent bonds,
• z is from 0 to 4,
• and the polymerization of the at least one olefin is effected in an aqueous medium which comprises at least 50% by volume of water.