Patent ID: 8841475

Claim:
A phosphoric ester of the formula (I) wherein R 1 , R 2 and R 3 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 (OA 1 ) x , (A 2 O) y and (A 3 O) z in each case independently of one another are composed of units selected from the group consisting of CH 2 CH 2 O, C 3 H 6 O and C 4 H 8 O it being possible for the units CH 2 CH 2 O, C 3 H 6 O and C 4 H 8 O within the individual groups (OA 1 ) x , (A 2 O) y and (A 3 O) z to be in blockwise or randomly distributed arrangement, and x, y and z each independently of one another are a number from 25 to 120, 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) R 1 —(OA 1 ) x —OH formula (II) R 2 —(OA 2 ) y —OH formula (III) R 3 —(OA 3 ) z —OH formula (IV) where R 1 , R 2 , R 3 , (OA 1 ) x , (A 2 O) y and (A 3 O) 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.