Salt S comprising: i) at least one acid AC of formula R-(OC m H 2m) w (OC n H 2n) z -X wherein - R is selected from H, optionally substituted linear or branched C 1 -C 22 alkyl, C 6 -C 20 aryl or aralkyl and mixtures thereof, - groups -(OC m H 2m) w and (OC n H 2n) z are linear or branched polyoxyalkylene groups, wherein m and n independently are an integer of from 2 to 5 and w in which the sum of w + z and z an integer of from 0 to 20, in which the sum of w + z is between 1 and 40, and mixtures thereof, - X is a group selected from -O-R1-COOH, -S-R1-COOH, -NR2-R1-COOH, -P(=O)OR3OR4, -O-P(=O)OR3OR4, -O-PO 3 H, -O-R1-P(=O)OR3OR4, wherein R1 is an optionally substituted linear or branched C 1 -C 4 alkylene, C 6 -C 20 aryl or aralkyl; R2 is selected from H, -R and -C(=O)R, wherein R is a group as defined above; at least one of R3 and R4 is H and the other may be H or R-(OC m H 2m) w (OC n H 2n) z - as defined above; and II) at least one amine AM of formula wherein - R5 and R6 are independently selected from H, optionally substituted saturated or unsaturated linear or branched C 2 -C 22 alkyl, C 4 -C 10 cycloalkyl, C 6 -C 20 aryl and aralkyl, at least one of R5 and R6 being other than H. i) at least one acid AC of formula R-(OC m H 2m) w (OC n H 2n) z -X wherein - R is selected from H, optionally substituted linear or branched C 1 -C 22 alkyl, C 6 -C 20 aryl or aralkyl and mixtures thereof, - groups -(OC m H 2m) w and (OC n H 2n) z are linear or branched polyoxyalkylene groups, wherein m and n independently are an integer of from 2 to 5 and w in which the sum of w + z and z an integer of from 0 to 20, in which the sum of w + z is between 1 and 40, and mixtures thereof, - X is a group selected from -O-R1-COOH, -S-R1-COOH, -NR2-R1-COOH, -P(=O)OR3OR4, -O-P(=O)OR3OR4, -O-PO 3 H, -O-R1-P(=O)OR3OR4, wherein R1 is an optionally substituted linear or branched C 1 -C 4 alkylene, C 6 -C 20 aryl or aralkyl; R2 is selected from H, -R and -C(=O)R, wherein R is a group as defined above; at least one of R3 and R4 is H and the other may be H or R-(OC m H 2m) w (OC n H 2n) z - as defined above; and - R is selected from H, optionally substituted linear or branched C 1 -C 22 alkyl, C 6 -C 20 aryl or aralkyl and mixtures thereof, - groups -(OC m H 2m) w and (OC n H 2n) z are linear or branched polyoxyalkylene groups, wherein m and n independently are an integer of from 2 to 5 and w in which the sum of w + z and z an integer of from 0 to 20, in which the sum of w + z is between 1 and 40, and mixtures thereof, - X is a group selected from -O-R1-COOH, -S-R1-COOH, -NR2-R1-COOH, -P(=O)OR3OR4, -O-P(=O)OR3OR4, -O-PO 3 H, -O-R1-P(=O)OR3OR4, wherein R1 is an optionally substituted linear or branched C 1 -C 4 alkylene, C 6 -C 20 aryl or aralkyl; R2 is selected from H, -R and -C(=O)R, wherein R is a group as defined above; at least one of R3 and R4 is H and the other may be H or R-(OC m H 2m) w (OC n H 2n) z - as defined above; and II) at least one amine AM of formula wherein - R5 and R6 are independently selected from H, optionally substituted saturated or unsaturated linear or branched C 2 -C 22 alkyl, C 4 -C 10 cycloalkyl, C 6 -C 20 aryl and aralkyl, at least one of R5 and R6 being other than H. - R5 and R6 are independently selected from H, optionally substituted saturated or unsaturated linear or branched C 2 -C 22 alkyl, C 4 -C 10 cycloalkyl, C 6 -C 20 aryl and aralkyl, at least one of R5 and R6 being other than H.