Morton L. Barr

Basic aluminum antiperspirant active material having enhanced activity, antiperspirant active composition containing such material, and methods for preparation of such material and composition

Disclosed are basic aluminum antiperspirant materials having univalent complex oxoanions (e.g., nitrate); methods of making such materials; antiperspirant compositions containing such basic aluminum materials, another antiperspirant active material (e.g., a basic zirconium halide salt), and optionally a neutral amino acid; and methods of making such compositions. Size exclusion high performance liquid chromatography chromatograms of the disclosed basic aluminum materials have a peak 4 relative area of at least 25%, a peak 3 relative area of less than 60%, the sum of the peaks 3 and 4 being at least 50%; and less than 10% of the chromatographic peaks eluting at peaks 1 and 2. The disclosed basic aluminum materials have less than 25% of the aluminum in the form of Alb polyhydroxyaquoaluminum, and have a 27 Al NMR spectrum in which the area of the 71.5-73.5 ppm resonance line includes more than 50% of the combined areas of the 62.5-63.5 ppm and 71.5-73.5 ppm resonance lines, and 5%-30% of the total area under the spectrum from 140 ppm to -80 ppm is contained in the resonance line at 71.5-73.5 ppm. The basic aluminum material of the present invention can be produced by adding a stoichiometric or near-stoichiometric amount of aluminum metal to a solution of an aluminum salt having a univalent complex oxoanion; the basic aluminum material can also be made by adding to such solution of the aluminum salt, aluminum metal having, in total, a relatively small surface area (large-sized particles of aluminum).