CONDUCTOMETRIC TESTING AND CORROSION STUDY OF HAIR SPRAY 1.51 5OO • 4oo E •oo • •oo ._ • •oo o t o o I 2 ---'-ml IN Na0H Figure I 3 4 2 3 4 5 oo[ 4oo F -•. --• ml IN HCI Figure 2 Conductometric titration A--2.4 g Resyn 28-1310 in 100 ml anhydrous ethanol B--2.71 g Rcsyn 28-1310 90% neutr. with AEPD in 1()0 ml anhydrous ethanol C--0.31 g AEPD in 100 ml anhydrous ethanol 2OO Figure $. Conductivity of a hair spray product during its lifetime This method is useful not only for hair sprays but also for any aerosol products having low conductivity, where the conductivity of the con- tents substantially changes by forming HC1 from Freon 11, or by reac- tion with the metal of the container. EXPERIMENTAL Method and .•1 pparatus For evaluation of results, the Conductivity Bridge,* Model 1t5 B2, was used. This was equipped with a glass-type cell (0.1 cell constant) having black platinized platinum electrodes. Approximately 3 ml of the liquid sample was collected by spraying out of the 3-piece 8 oz tinplated aerosol can into a test tube, and after four hours of condi- tioning at room temperature (24 øC) the conductivity was measured. * Industrial Instruments, Inc.

JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS o 20 o I I I I I I 0 I 2 3 4 5 6 7 • Time (hrs.) Figure 4. Conductivity of a hair spray sample at different times after spraying out of a container 4 6 8 I0 No, of runs Figure 5. Air concentration in vapor space in container without dip tube at consecutive determinations / 0 I0 20 30 40 / 0 I0 20 30 40 • Time (days} • Time (days} 200 ,oo ,ooL I , , f o I•"T"F , , , o• / o IO 2o $o 4o o IO 2o $o 4o , Time (doys} • Time (doys} Figure 6 Figure 7 Comparison of value of pH and conductivity as they relate to corrosion at similar times (at 48øC = 120øF) Conc.: 3(• VEM-9 (90% neutr. with AMPD) in 90% by wt. ethanol Fill: Fig. 6--35t)• conc., 65% F12/11 35/65 Fig. 7--35% conc., 65% F12/11S 35/65 A--less than 0.5% air in vapor space B--approx. 8% air in vapor space