| abstract |
A surfactant characterized in that it comprises a mixture of an acidic or neutral N-acyl 8-24-amino acid and a base, wherein said base has an ionic pair formed by an anion derived from a carboxyl group of an amino acid and a cation which derived from alkali metals, alkaline earth metals, organic amines, basic amino acids, sodium N-methyltaurine, potassium N-methyltaurine, sodium taurine, potassium taurine, and said acidic or neutral N-acyl C 8-24-amino acid and said base is mix and neutralize to form an ionic pair having a pH of 5 to 9, in which the amount of said base is 1.0 to 1.6 equivalents relative to 1 equivalent of N-acyl C 8-24-amino acid and, in the case where the N-acyl C 8-24-amino acid has two carboxyl groups, it is 1.3 to 2.3 equivalents relative to 2 equivalents of N-acyl C8-24-amino acid. |