PROBLEM TO BE SOLVED: To provide a substrate for a cosmetic sheet that safely and sustainedly releases a cosmetic component onto the skin, exhibits excellent adhesion to the skin, imparts moisture and tightness to the skin and permits deep penetration of the cosmetic component into the skin.SOLUTION: The substrate for a cosmetic sheet comprises a regenerated cellulose flat film having an average pore size of at least 20 nm and at most 1 &mum, a film thickness of at least 50 &mum and at most 500 &mum and a porosity of at least 70% and being composed of at least 100 layers. The surface having a larger pore size of the film is brought into close adhesion to the skin. A pharmaceutical to penetrate into the skin is held in a pore in the film in the form of an aqueous solution. The cosmetic component held is caused to sustainedly release into the skin through a diffusion mechanism of pore diffusion and diffusion within the liquid.COPYRIGHT: (C)2012,JPO&INPIT【課題】化粧成分を皮膚に安全に徐放させ、皮膚との密着性が優れ、皮膚に水分とハリを与える、皮膚内部への高浸透性の効果がある化粧シート用基材を提供すること。【解決方法】本発明の化粧シート基材では、平均孔径が20nm以上1um 以下、膜厚は50um 以上500 um 以下、空孔率70% 以上で100 層以上の再生セルロース平膜を用いる。膜の孔径の大きい面を皮膚に密着させ、皮膚に浸透させる薬剤は膜中の孔に水溶液の形で保持させる。孔拡散と液体内拡散の拡散機構で、保持した化粧成分を皮膚に徐放させる。【選択図】 なし
