Process for the manufacture of dispersions of homo-and copolymers of acrylic acid esters and methacrylic acid esters having positively charged latex particles

摘要

Aqueous dispersions of homopolymers of acrylic or methacrylic esters or copolymers of such esters with each other or with vinyl esters or esters of maleic acid with monohydric saturated aliphatic alcohols are made by polymerizing the monomer(s) in an aqueous medium in the presence of a free-radical catalyst and 2-14%, calculated on the weight of monomer, of a water-soluble nitrogen-containing polyalkylene glycol of the formula FORM:1001715/C3/1 wherein A represents a polyalkylene glycol chain containing 3 to 2000 alkylene oxide units and R1 represents a bivalent hydrocarbon radical containing 2-14 carbon atoms. The resulting dispersions contain positively charged polymer particles. Catalysts specified are hydrogen peroxide, alkali peroxide and perborates and urea peroxide, which may be used in combination with reducing agents, e.g. ferrous ammonium sulphate, to form redox systems. Catalyst and monomer may be added portionwise during the course of the reaction. Also present in the reaction mixture may be oxyethylated propylene oxide and higher alkylene oxides described in Specification 896,510. The examples describe the use of nitrogen-containing polyalkylene glycols of the formula FORM:1001715/C3/2 in which (a) X=25 and Y represents a figure such that the proportion of ethylene oxide units in the compound amounts to about 80% by weight, and (b) in which X=about 14 and Y=about 44. The polymerization is described of ethyl acrylate, methyl methacrylate, and mixtures of butyl acrylate and methyl methacrylate. Specification 943,198 also is referred to.