Antiperspirant Active Compositions and Manufacture Thereof

摘要

A method of making an antiperspirant active composition and the use of a heating step at elevated temperature to convert Al13 polyhydroxyoxoaluminum cations in the species detectable by 27Al NMR within an aqueous aluminum salt solution into Al30 polyhydroxyoxoaluminum cations in the species detectable by 27Al NMR without increasing a SEC Peak 3 area in the SEC chromatogram of the aluminum salt.

主权项

1. A method of making an antiperspirant active composition comprising:
I) heating an aqueous solution containing a first aluminum salt having an aluminum to chloride molar ratio of 0.3:1 to 3:1 and a buffer, wherein the buffer is an amino acid or betaine and a molar ratio of buffer to aluminum is at least 0.1:1, at a temperature of 50° C. to 100° C. for a period of time of 1 hour to 6 hours to obtain a first aluminum salt solution; II) adding to the first aluminum salt solution an aqueous solution of an inorganic base to obtain a second pH adjusted aluminum salt solution having an OH:Al molar ratio of at most 2.6:1 and a pH of 2 to 5; III) heating the second pH adjusted aluminum salt solution at a temperature of 50° C. to 100° C. for a period of time of at least 6 hours to obtain a third aluminum salt solution containing a third aluminum salt exhibiting an 27Al NMR spectrum with a species distribution including at least 90% Al30 polyhydroxyoxoaluminum cation as the predominant species detectable by 27Al NMR within the third aluminum salt; and IV) optionally adding an aqueous solution containing a zirconium compound to the second pH adjusted aluminum salt solution to thereby obtain a second pH adjusted aluminum-zirconium salt solution having a molar ratio of aluminum to zirconium of 5:1 to 10:1.