430 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS 20 15 IO 5 O 0 o ß [] I 20'C RI2Ts.2G4.o Ri2E09 RI2EOi2 I i I 2O 4O 6O 8O I00 Rel(•tive Humidity {%1 Figure l 1. Water-retaining capacity of R•2TxGy and R•2EO x as a function of relative humidity. 20 Figure 12. at 40øC. I I I I 40'C 20 R 12T7.sG7.9 - 0 0 0 0 I I I i I 2 3 4 Week 40'C 20 43 I I I I 0 I 2 3 4 Week Formaldehyde content and change in pH of R•2T7.9G7.8 and R•2EO2o while in aqueous solution

POLY(GLYCERYL) ALKYL ETHER SURFACTANTS 431 Rle,lEO•o 8 õ 4 • o 0•,- -- • , • // o IO 20 30 IOO H20 wt % Surfactant 50 40 30 20 I0 0 0 H•O (b) El Rm.lEOio ß R 18:1E02_o o RisTi4.1Gi3.2 5 I0 30 I00 wt % Surfactant ....... Chemosls Hyperemla Figure 13. (a) Dermal and (b) eye irritation scores of R•sT•4.•G•3.2 and RnEO x in aqueous solution. CONCLUSION The emulsifying properties of poly(oxytetramethylene) poly(glyceryl) alkyl ether surfac- tants are summarized as follows: 1) The HLB-value of these surfactants increases from 7 to 30 with increasing chain length of the hydrophilic group. 2) RnTxGy does not form a hexagonal or cubic liquid crystalline phase in aqueous solu- tions. Therefore, these surfactants are suitable for paste emulsification. 3) RnTxGy can emulsify several types of oils from nonpolar to polar, and provide stable O/W emulsions. 4) R•T•Gy exhibits humectant properties. 5) Even though R18T14.6G13.2 is very hydrophilic (HLB-value = 30), it provides fine O/W emulsions. 6) The chemical stability of R•T•Gy is greater than that of R•EO•. 7) RnTxGy is safe for the skin and eyes. ACKNOWLEDGEMENT The authors express their appreciation to Mr. H. Momota for his technical assistance. REFERENCES (1) H. Gissepen and B. Magnusson, Effects of detergents on guinea pig skin, Acta. Dermatovener, 46, 269-274 (1966).