Studies on Plant Pigments (2) : Dyeing properties of Dioscorea chirrhosa L_<our> (Department of Forestvy)

ソメモノイモの染色性について検討し, 次の結果を得た。1)ソメモノイモの熱水抽出物は約17%であった。2)素材に絹布を用いて染色条件を検討した。その結果, 最適染色条件は染料濃度が5%, 染色温度が80℃, および染色時間は60分であった。3)最適染色条件で染色した絹布を重クロム酸カリウム, 及び硫酸第一鉄で媒染を行ったとき発色が顕著だった。また, この時の媒染色剤濃度は, 重クロム酸カリウムで75ppm, 硫酸第一鉄で100ppmが適当と考えられた。4)染色堅牢度のうち最も重要な日光堅牢度, および洗濯堅牢度について検討した。最適染色条件で染色し, ここでは, 重クロム酸カリウム, および硫酸第一鉄で媒染した。その結果, 日光堅牢度が優れており(5級以上), また洗濯堅牢度も5回以上の重ね染めにより安定した。The dyeing properties of root of Somemonoimo, Dioscorea chirrhosa L_, for silk cloth, traditionally used in making Ryukyuan textile, were examined. The results of obtained are summarized as follows. 1. An amount of hot water extracts from roots of Dioscorea japonica Thmb. contained approximately seventeen percent. 2. The conditions of dyeing were determined for silk cloth. The optimum concentration of dyes, the optimum dyeing temperature, and the optimum dyeing time were five percent, 80℃, and 90min. respectively. 3. The cloth which was dyed with the extracts was mordanted to pale brown with potassium permanganate and iron (II) sulfate. Their optimum concentration were 75ppm of potassium permanganate and 100ppm of iron (II) sulfate respectively. 4. The most important factor of color fastness in dyeing was examined. The cloth which was dyed under optimum condition with potassium permanganate. These types of color fastness were in proportion to the times under repeating dyeing and kept constant at five or more