Method For Producing Alkoxylated Phosphoric Acid Triesters

A phosphoric ester of the formula (I)

• wherein
• R1, R2 and R3 may be alike or different and are a linear or branched, saturated alkyl group having 6 to 30 carbon atoms, a linear or branched, mono- or polyunsaturated alkenyl group having 6 to 30 carbon atoms, or an aryl group, which may be substituted by 1 to 3 branched alkyl groups each independently of one another containing 3 to 18 carbon atoms,
• the individual groups (OA1)x, (A2O)y and (A3O)z in each case independently of one another are composed of units selected from the group consisting of CH2CH2O, C3H6O and C4H8O it being possible for the units CH2CH2O, C3H6O and C4H8O within the individual groups (OA1)x, (A2O)y and (A3O)z to be in blockwise or randomly distributed arrangement, and
• x, y and z each independently of one another are a number from 10 to 150,
• prepared by a process which comprises
• a) reacting phosphoric acid or a phosphoric acid derivative selected from the group consisting of orthophosphoric acid, tetraphosphorus decaoxide, and polyphosphoric acid with alkoxylated alcohols of the formula (II), (III) and (IV)
• R1—(OA1)x—OH formula (II)
• R2—(OA2)y—OH formula (III)
• R3—(OA3)z—OH formula (IV)
• where R1, R2, R3, (OA1)x, (A2O)y and (A3O)z are defined as in formula (I),
• b) in a molar ratio of phosphoric acid or phosphoric acid derivative to alkoxylated alcohol of 1:2.5 to 1:3.3,
• c) at 200 to 240° C.