| abstract |
A water-soluble flame-retardant polyester resin which is obtained by subjecting a dicarboxylic acid ingredient, a glycol ingredient, an ingredient for imparting water solubility, and a reactive phosphorus compound to condensation or polycondensation so that the water-solubility-imparting ingredient accounts for 1 to 60 mol% of the sum of the dicarboxylic acid ingredient and the water-solubility-imparting ingredient. This polyester resin is soluble in solvents because it was obtained by imparting water solubility to a phosphorus-containing polyester which is halogen-free and excellent in flame retardancy, etc. Applicability can hence be improved and the problems concerning working atmospheres and environmental preservation which are attributable to solvents can be eliminated. When the polyester resin is used in the treatment of works such as fibers, PET films, etc., it does not deteriorate these works. |