Novel Environment-friendly Green Pigments for Over-glazed Decoration of Arita Ware

摘要

新規な環境調和型の(Y_(1-x)R_x)BaCuO_5(0≤x≤0.3:R=Sm~(3+),Gd~(3+),Yb~(3+),Lu~(3+))顔料を固相反応法により合成し，それらの色彩を評価した。添加元素種および組成の最適化を行った結果，Lu~(3+)を添加した(Y_(0.9)Lu_(0.1)_2BaCuO_5試料の緑色度(-a~*=48.6)が最大となることが明らかになった。この値は,市販の緑色無機顔料であるクロムグリーン(Cr_2O_3)(-a~*=18.2)およびコバルトグリーン(ZnO·CoO)(-a~*=25.3)を大きく凌いだ。さらに，合成したY_2BaCuO_5および(Y_(0.9)Lu_(0.1))_2BaCuO_5顔科を陶磁器用の上絵具に用いたところ,今までの有田焼にない鮮明な緑色が得られたことから,新しい有田焼の上絵用顔料として有望であることがわかった。%Environmental-friendly inorganic green pigments based on (Y_(0.9)R_(0.1))_2BaCuO_5 (R = Sm~(3+), Gd~(3+), Yb~(3+), and Lu~(3+)) solid solutions were synthesized and the dopant element was optimized to give the most greenish color. Among the samples, it was found that Lu-doped sample showed brilliant green hue. In response to the results, (Y_(1-x)Lu_x)_2BaCuO_5 (0 ≤x ≤ 0.3) pigments were further synthesized and their color properties were characterized in an attempt to find a new environmentally friendly pigment that has more sufficient green chromaticity. Among the samples, the most vivid green hue was obtained for (Y_(0.9)Lu_(0.1)_2BaCuO_5 with a greenness value (-a~*) of 48.6 in the CIE L~*a~*b~* system, which was significantly larger than those of commercially available Cr_2O_3 (-a~* =18.2) and CoO·ZnO (-a~* = 25.3) pigments. The Y_2BaCuO_5 and (Y_(0.9)Lu_(0.1))_2BaCuO_5 pigments were used in paints for porcelain. The green colors of the overglazed decoration panels were brilliant. Therefore, these pigments could be the potential candidates for novel green pigments of over-glazed decoration of Arita ware.