• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.4 s.54
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• pp.337-342
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• 2005

The aim of this study was to evaluate the influence of different skin care ingredient concentrations on the effect of polyols and oils on the human skin moisturization and skin surface roughness. Polyols and oils were essential ingredients to make a skin care formulation. But these were still not understood how much concentration(s) were tested on human skin in the aspect of efficacy and sensory. We studied to examine various concentrations of ingredient by cosmetic companies using noninvasive methods. Polyols were composed of glycerol and butylene glycol (BG) as 1:1 ratio, and oils were hydrogenated polydecene, cetyl ethylhexanoate and pentaerythrityl tetraethylhexanoate (PTO(R), Stearinerie Dubois Fils Co., France) as 1:1:1 ratio. All compounds were tested $0{\sim}27%dml$ Polyols and $0{\sim}35%dml$ oils in O/W emulsions. We investigated the effect of water contents and the effect of stratum corneum roughness in forearm skin after application of compounds. Water contents of the skin measured by skin capacitance and skin surface roughness measured visual scoring of skin surface biopsy through the scanning electron microscopy. Water contents of the skin were highly related to amount of polyols (to 20%) and oils (to 12%). Correlation coefficients were 0.971 and 0.985 respectively (p<0.01), 2 h after application. Skin surface roughness was positively correlated with polyol contents in concentration dependent manner, and depend on oils up to 6%. The ratio of coefficient was 2.5 to 1 (polyol to oils) by regression analysis. Further studies will be conducted with other ingredients such as surfactants, lipids and aqueous materials, and with ether methods for noninvasive measurement.

• Polymer(Korea)
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• v.36 no.4
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• pp.440-447
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• 2012

The branched copolyester was synthesized and its molecular weight, $T_g$, 1/2 method temperature ($T_{1/2}$) and rheological properties were characterized for the application of toner binder. The linear copolyester had low molecular weight and melt elasticity obtained by dimethylterephthalate (DMT), ethylene glycol (EG) and 2,2-bis(4-(2-hydroxypropoxy) phenyl)propane (HPP). The branched copolyesters prepared with various branching agents such as 2-(hydroxymethyl)-2-ethylpropane-1,3-diol (trimethylol propane, TMP), 2,2-bi(hydroxymethyl)-1,3-propanediol (pentaerythritol, PER), 1,2,4-benzenetricarboxylic anhydride (trimellitic anhydride, TMA) and glycerol to improve the physical properties of the linear copolyester. The effect of branching agents on the molecular weight and melt elasticity of the branched copolyester was examined. The branched copolyesters prepared by adding over 15 mol% of branching agent showed relatively high molecular weight and melt elasticity, and $T_{1/2}$ value of $140^{\circ}C$. Therefore, the highly branched copolyesters were deemed suitable as a hot-melt toner of laser print process.