Application of Ester Quats as Hair Conditioning Agents

Biodegradable quats, such as monoethanol ester diethyl monomethyl ammonium chloride (MEC) and diethanol ester dimethyl ammonium chloride (DEC) are expected as new ingredients for hair conditioners, while monoalkyl trimethyl ammonium chloride (MAC) and dialkyl dimethyl ammonium chloride (DAC) have been widely used as hair conditioning agents. We investigated properties of MEC and DEC (ester quats: EQ) in comparison with MAC and DAC (alkyl quats: AQ) for hair conditioner application. EQ showed good water holding ability and adsorption property on keratin powder compared with corresponding AQ. These results seemed to relate to the ester linkages of EQ. Bending moment of hair treated by AQ was better than that of EQ, however, it was found that DEC is comparable to MAC. The result of sensory evaluation suggested that EQ are possible ingredients for hair conditioners. These findings would promote development of hair conditioners with EQ. Especially, it is considered that DEC is new and unique ingredient for hair conditioner.