SYNTHETIC ESTER DISPERSING AGENTS 215 5O 4O 5 30 z 2o u.i o o 30 60 90 12o 15o 18o 2Io 240 TIME,seconds Figure 2. Aluminum chlorhydroxide complex with dispersing agent (oeo•' code see Fig. 1) 40 o '- 30 •. •o lo FH 30 60 90 120 150 180 TIME,seconds Figure 3. Sta]'ch with dispe•sing agent (fo•' code see Fig. 1) 210 240

216 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS 0 30 60 90 120 150 180 210 240 TIME,seconds Figure 4. Talcum with dispersing agent (for code see Fig. 1) Additional samples were prepared by placing 4 g each of the appropriate fluid and powder in a mortar. The mixture was thoroughly mixed and poured into a compatibility tube. Propellant 11 was used to rinse the mortar, and the rinsings were added to the compatibility tube. A total of 35 ml of Propellant 12 was added to bring the final volume to exactly 80 ml. The samples were placed into a water bath and treated as was previously indicated. Since no differences were noted between the results obtained when the dispersing agent was dissolved in the propellant or when they were dispersed directly onto the powder, the results shown in Figs. 2-4 are representative of the re- suits obtained by both methods of mixing. Dispersibility of Powders-Additional samples were prepared exactly as was previously indicated. After the contents of each compatibility tube had attained a temperature of 25 ø C - 1 ø and the volume had been brought to exactly 80 ml, the tubes were inverted serveral times to disperse the powder. The tubes were then stored upright, and the number of inversions required to fully disperse the powders after they had been standing 24 hours and then af- ter they had been standing 1 week were recorded. Table III indicates the re- sults that were obtained when the dispersing agents were added directly to the propellant, while Table IV gives the results when the dispersing agents were mixed directly with the solid.