Abstract: Disclosed is a process for the preparation of polyesters, comprising the following steps and characterized by the following measures: a) suspending polyethylene terephthalate waste in ethylene glycol and/or in 1,2-propylene glycol containing a transesterification catalyst, b) heating the reaction mixture to depolymerize the polyethylene terephthalate waste for a time sufficient to decompose the polyethylene terephthalate into monomers and into oligomers, c) addition of end group forming monomers in the form of polyalkylene glycol monoalkyl ethers, fatty alcohols, fatty amines, fatty acids or esters thereof or mixtures of two or more thereof, and/or sulfo(poly)alkylene glycols and/or sulfoaryl carboxylic acids or esters thereof, d) addition of sulfoarylene dicarboxylic acids or polyester-forming derivatives thereof, e) optionally adding aliphatic diols, cycloaliphatic diols, organic dicarboxylic acids, their polyester-forming derivatives, crosslinkers or mixtures of two or more thereof, f) heating the react

Abstract: Disclosed are aqueous compositions of selected anionic polyesters and of selected nonionic polyesters. These compositions are characterized by good storage stability and low viscosity and can be used in detergents and cleaning agents to improve soil release.

Abstract: Disclosed are polyesters containing structural units corresponding to formula (I) or to formula (II) or to formulae (I) and (II), structural units of formula (III) or of formula (IV) or of formulae (III) and (IV), and optionally structural units of the formula (V) —CO—R1—CO—O—C2H4—O—??(I), —CO—R1—CO—O—(C3H6—O)—??(II), —CO—R2—CO—O—C2H4—O—??(III), —CO—R2—CO—O—(C3H6—O)—??(IV), —CO—R3—CO—O—R4—O—??(V), as well as nonionic endgroups of the formula (VI), and optionally nonionic endgroups of the formula (VII) —CO—(O—C2H4—)n—OR5??(VI), —CO—OR6??(VII). In these structural units and endgroups R1 to R6 are selected organic radicals and n is a number between 30 and 500. The polyesters according to the invention are characterized by very good soil release properties, can be readily stored in detergent and cleaning agent formulations and can be used as soil-release polymers.