236 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS The salicylate end-blocked fluids contain an organic ester linkage. In this respect they differ from the products we will discuss later where the ester contains a carbon-oxygen-silicon linkage. In general, the organic ester linkage is much more stable toward hydrolysis than the carbon- oxygen-silicon linkage. If hydrolysis should take place, however, the products are likely to be salicylic acid and a high molecular weight di- methylpolysiloxane. TABLE 2--COMPARISON OF COMPATIBILITY OF SALICYLATE END-BLOCKED FLUIDS AND 200 FLUIDS WITH VARIOUS MATERIALS* Solicylote Dow Corning 200 Fluid End Blocked Fluid** 20cs Beeswax ...................................... C Lanaiin ...................................... C Mineral Oil ................................... C Petrolotum ................................... C Paraffin ..................................... C Ozokerite .................................... C Sesame oil ................................... i Tested at room temperature as a m•x made up of 1 part sd•cone to 10 parts material listed. M%S•O Content -- 12 units. C--compat•ble •--incompohble TABLE 2A--CoMPARISON OF COMPATIBILITY OF SALICYLATE END-BLocKED FLUIDS AND 200 FLUIDS WITH VARIOUS MATEKIALS* Solicylote Dow Corning 200 Fluid End Blocked Fluid** 20 cs Dow Corning •.00, 100 cs ....................... Dow Corning 555 .............................. Water ...................................... ?0% Isoproponol ............................. 95 % Ethanol .............................. 99% Isoproponol ............................. Ethylene glycol ............................... Propylcnc glycol .............................. Tested at room temperature os o m,x mode up of 1 port s,hcone to lO ports material hsted Me,S•O Content-- 12 umts C---compatible i--incompatible

NEW SILICONES FOR THE COSMETIC INDUSTRY TABLE 2B--CoMPARISON OF COMPATIBILITY OF SALICYLATE END-BLoCKED i•LUIDS AND 200 i•LUIDS WITH VARIOUS MATERIALS* 237 Sulicylute Dow Corning 200 Fluid End Blocked FluidO' 20•s Glycerine .................................... i Stcuryl alcohol ............................... C Isopropyl myristute ............................ C Glyceryl manustearute ......................... C Diglycol stearate ............................. C Oleic acid ................................... i Steorlc acid .................................. C * Tested at room temperature as a mix made up of 1 part silicone to 10 parts material listed. * * Me•SiO Content -- 12 units. C---compatible i--incompatible In contrast with the usual dimethylpolysiloxane (Dow Corning 200) fluids, this type of fluid is soluble in many organic materials (Table 2). Solubility was determined by mixing one part by weight of the silicone with ten parts of the organic material. The mixture was heated (above the melting point of the solids, if present in mix), stirred and cooled to I00 •- 7O •. 60 o _ • 50 c- ,- 40 "3 30 Cell = Standard Path Length • 1 Reference • Air 280 290 300 310 320 330 340 350 360 3?0 380 390 400 410 420 Vv'AVE LENGTH, rnilhrmcrons Figure 1. Light transmission of salicylate end-blocked fluid.