ethylene oxide with a reaction product of a carboxylic acid having a c 4 to c 20 alkyl or alkenyl group and an alkanolamine adduct having a molecular weight of at most 1 000 of at least 3 moles of ethylene oxide with a polyhydric alcohol a polycarboxylic acid a polyamine a polyhydric phenol or their derivatives adduct having a molecular weight of at most 1 000 of at least 3 moles of propylene oxide with a polyhydric alcohol a polycarboxylic acid a polyamine a polyhydric phenol or their derivatives adduct having a molecular weight of at most 1 000 of at least 3 moles of a mixture of ethylene oxide and propylene oxide with a polyhydric alcohol a polycarboxylic acid a polyamine a polyhydric phenol or their derivatives adduct having a molecular weight of at most 5 000 of at least 3 moles of ethylene oxide with an ester of castor oil or lanoline having hydroxyl group adduct having a molecular weight of at most 5 000 of at least 3 moles of propylene oxide with an ester of castor oil or lanoline having hydroxyl group adduct having a molecular weight of at most 5 000 of at least 3.