PROBLEM TO BE SOLVED: To provide a penetration enhancing agent having a superior effect on enhancing penetration to hair and solubility in water, and to provide a hair cosmetic containing the penetration enhancing agent and a water-soluble active component and exhibiting superior penetration performance of the active component.SOLUTION: The penetration enhancing agent includes a diester of a dicarboxylic acid expressed by formula 1 and a polyoxyethylene monoalkyl ether expressed by formula 2. Formula 1: HO-CO-R1-CO-OH (in the formula, R1 is 2-10C straight, branched or cyclic hydrocarbon group). Formula 2: R2-(OCH2CH2)n-OH (in the formula, R2 is 1-12C straight, branched or cyclic hydrocarbon group and n is integer of 2-11).COPYRIGHT: (C)2013,JPO&INPIT【課題】毛髪への優れた浸透促進効果を有し、更に水溶性を兼ね備えた浸透促進剤の提供。また、該浸透促進剤と水溶性有効成分とを含有した、有効成分の浸透性に優れる毛髪化粧料の提供。【解決手段】化1で表されるジカルボン酸と化2で表されるポリオキシエチレンモノアルキルエーテルとのジエステルを含有する浸透促進剤を用いる。【化1】HO-CO-R1-CO-OH(式中、R1は炭素数2~10の直鎖、分岐鎖若しくは環状の炭化水素基を表す)【化2】R2-(OCH2CH2)n-OH(式中、R2は炭素数1~12の直鎖、分岐鎖若しくは環状の炭化水素基であり、nは2~11の整数を表す)【選択図】なし
