Methods of Making Solid Stick Antiperspirant Compositions

Abstract

A method of manufacturing a packaged solid stick antiperspirant composition is provided. The method includes combining an antiperspirant active, one or more structurants and a surfactant to form a mixture, dispensing the mixture from a nozzle to fill a dispensing package, forming a solid stick antiperspirant composition within the dispensing package. The surfactant has a melt temperature that is greater than the crystallization onset temperature of the solid stick antiperspirant composition. The antiperspirant active and the surfactant are in contact for about 5 minutes or less from the moment that the antiperspirant active and the surfactant and the structurant are mixed until the moment that the mixture is dispensed from the nozzle.

What is claimed is: 
     
         1 . A method of manufacturing a packaged solid stick antiperspirant composition, comprising:
 combining an antiperspirant active, one or more structurants and a surfactant to form a mixture;   dispensing the mixture from an exit opening to fill a dispensing package;   forming a solid stick antiperspirant composition within the dispensing package; and   wherein the solid stick composition is a single phase, the surfactant has a melt temperature that is greater than the crystallization onset temperature of the solid stick antiperspirant composition and wherein the antiperspirant active and the surfactant are in contact for about 5 minutes or less from the moment that the antiperspirant active and the surfactant and the structurant are mixed until the moment that the mixture is dispensed from the exit opening;
 wherein the active is a particulate and the solid stick antiperspirant composition is anhydrous; and 
 wherein the antiperspirant active has a hygroscopicity greater than 30% at 86% relative humidity after 5 days and a metal to chloride ratio less than 1.5. 
   
     
     
         2 . A method according to  claim 1 , wherein the antiperspirant active is aluminum zirconium tetrachlorodrex or aluminum zirconium tetrachlorohydrate glycine. 
     
     
         3 . A method according to  claim 1 , wherein the antiperspirant active has a metal to chloride ratio greater than 1.3. 
     
     
         4 . A method according to  claim 3 , wherein the antiperspirant active is aluminum zirconium pentachlorohydrate glycine or aluminum zirconium pentachlorohydrex. 
     
     
         5 . A method according to  claim 1 , wherein the antiperspirant active has a metal to chloride ratio greater than 1.4. 
     
     
         6 . A method according to  claim 1 , wherein the solid stick antiperspirant composition is substantially or completely free of aluminum zirconium tetrachlorohydrate glycine having a metal to chloride ratio less than 1.3. 
     
     
         7 . A method according to  claim 1 , wherein the surfactant is a non-ionic exthoxylated linear alcohol having a carbon chain length from about 20 to about 40. 
     
     
         8 . A method according to  claim 1 , wherein the surfactant is has an HLB value between 6 and 12. 
     
     
         9 . A method according to  claim 1 , wherein the surfactant has a melt temperature from 70° C. to 120° C. 
     
     
         10 . A method according to  claim 1 , wherein the surfactant has a concentration from about 1% to about 4% by weight of the solid stick antiperspirant composition. 
     
     
         11 . A method according to  claim 1 , wherein the one or more structurants has a melt temperature less than 85° C. 
     
     
         12 . A method according to  claim 1 , wherein the one or more structurants comprises at least one material selected from the group consisting of stearyl alcohol, hydrogenated castor wax, ozokerite, behenyl alcohol, polyethylene, polymethylene and a triglyceride. 
     
     
         13 . A method according to  claim 1 , wherein the antiperspirant active and a liquid carrier are mixed in a first tank to form a first composition at first temperature and wherein the structurant and surfactant are mixed in a second tank at a second temperature that is greater than the first temperature to melt the structurant and wherein the first composition is pumped from the first tank to a static mixer comprising a plurality of static baffles and the second composition is pumped from the second tank to the static mixer. 
     
     
         14 . A method according to  claim 1 , wherein the temperature of the mixture at the moment that the mixture leaves the exit opening is at least 10° C. above the onset of crystallization temperature of the solid stick antiperspirant composition. 
     
     
         15 . A method according to  claim 1 , wherein the solid stick antiperspirant composition has a Red Dot Color Value of 0.5 or less at 4, 5, 10 and 15 minutes and a Red Dot Color Value greater than 1 at 30 seconds. 
     
     
         16 . A method according to  claim 1 , wherein the antiperspirant active has a concentration from 12% to 35% by weight of the solid stick antiperspirant composition.