Production of copolymer powders from maleic anhydride and 1-olefins

A process for the production of a copolymer which comprises reacting maleic acid anhydride and an excess of at least one 1-olefin having from 2 to 8 carbon atoms at a temperature of from 30.degree. C to 200.degree. C and a pressure of from 1 to 200 atm in an organic dispersion medium comprising said 1-olefin or said 1-olefin and a solvent which is inert with respect to the monomers and which dissolves the 1-olefin but not maleic acid anhydride, the reaction taking place in the presence of a radical former and from 0.5 to 10% by weight based on the maleic acid anhydride of a dispersion agent soluble in the dispersion medium which is obtained by the reaction of:

• I. 1 mol of a copolymer of maleic acid anhydride and a 1-olefin having from 2 to 8 carbon atoms, with
• Ii. from 1 to 10 mol of an aliphatic, saturated or monoolefinically unsaturated, linear or branched, monohydric alcohol having from 8 to 22 carbon atoms, or from 1 to 10 mol of an aliphatic, saturated, linear or branched monoamine having from 8 to 22 carbon atoms or from 1 to 10 mol of a mixture of the monohydric alcohol and monoamine, at least 30 mol% of the anhydride groups being esterified to semi-esters or amidated to semi-amides.