05.01.19
US Patent No. 10,226,404 B2 (Kenji Takahashi, Junichi Yokogi); The Procter & Gamble Company has patented a method of preparing a hair care composition that comprises a cationic surfactant system (wherein the cationic surfactant system comprises a mono-long alkyl quaternized ammonium salt wherein the mono-long alkyl quaternized ammonium salt is behenyl trimethyl methosulfate, and a di-long alkyl quaternized ammonium salt wherein the di-long alkyl quaternized ammonium salt in dicetyl dimethyl ammonium chloride); a high melting point fatty compound having a melting point of 25°C to 90°C selected from the group consisting of cetyl alcohol, stearyl alcohol, benzyl alcohol and mixtures thereof; an aqueous carrier; and an antidandruff agent selected from metal pyrithiones wherein the metal pyrithione is zinc pyrithione. The method comprises the following steps: mixing the cationic surfactant system, high melting point fatty compound and aqueous carrier to form an emulsion; and adding the antidandruff agent to the emulsion by in-line injection with one pass mixing.
