Studies of aqueous resins: IV. Characteristics of water-dispersed polyesters containing polar groups

Ester copolymers containing small amounts of sodium sulphonate groups in their backbone were prepared from tere- and isophtalic acids, adipic acid, 1,2-ethanediol, 2,2-dimethyl-1,3-propanediol and 1,4-butanediol. Stable aqueous dispersions of these polymers could be obtained by using 2-butoxyethanol as a cosolvent. To clarify the role of the cosolvent, they were separated into two layers, polymer and supernatant layers, by ultracentrifugation. Cosolvent contents were found to be different in the former and latter layers. Characteristics of the dispersions such as viscosity are strongly affected by the content of the cosolvent.