Verfahren zur Herstellung von wasserlöslichen Polyestern und Copolyestern, die danach hergestellten Produkte und deren Verwendung

摘要

Disclosed is a method of preparing polyesters in powder form by means of polycondensation of dicarboxylic acid diol precondensates (oligomers) at elevated temperature in a heat transfer medium in the presence of polycondensation catalysts and optionally cocondensable modifiers. The liquid heat transfer medium is inert and free of aromatic components and has a boiling point in the range of 180 to 300 DEG C. The dicarboxylic acid diol precondensate contains on analytical average 1 to 30 mol % oligomer or monomer containing at least one sulfonic acid group. The weight ratio of dicarboxylic acid diol precondensate to liquid heat transfer medium is in the range of 20:80 to 80:20 and the polycondensation is carried out in the presence of a dispersion stabilizer, the resulting polyester being water-soluble.