Polyesters and their use

A polyester comprising at least one diacid-based building block, at least one diol-based building block and at least one polyol-based building block, wherein the diacid-based building block comprises a group of formula (I)

• wherein R1 is a group according to the formula-A1—O—(C═O)—CH2—O—(AO)x—X1, with x being a number from zero to 75, X1 being hydrogen or methyl and AO being alkylene oxide selected from the group consisting of ethylene oxide and combinations of ethylene oxide with at least one of propylene oxide and butylene oxide,
• wherein A1 is C2-C6-alkylene, branched or straight-chain,
• wherein the polyol building blocks are derived from compounds bearing y hydroxyl groups per molecule, and y is at least three,
• wherein the asterisks indicate bonds to diol or polyol building blocks through the ester oxygen atoms, and
• wherein the molar ratio of diacid-based building blocks to the sum of diol building blocks and polyol building blocks, the latter being multiplied with 2/y, is in a range from 2:1 to 1:2.