| 摘要 |
PURPOSE:To provide a stable, nontoxic, inexpensive, reversible heat-sensitive material capable of exhibiting a reversible change in color tint accompanying a change in temp., which is composed mainly of a Bi2O3-Cr2O3 polycrystalline material obtained by mixing a Bi compd. with a Cr compd. at a specific molar ratio and calcining the mixture. CONSTITUTION:50-86mol% bismuth compd. such as oxide, hydroxide, halide, nitrate (e.g.; Bi2O3) or org. compd of bismuth is mixed with 50-14mol% chromium compd. (e.g.; Cr2O3). The mixture is calcined, and an intended reversible, heat-sensitive material is prepared using the bismuth oxide-chromium oxide polycrystalline material as a main component. The reversible, heat-sensitive material changes in color tone reversibly from green and yellow to yellow and red at about 140 deg.C. The tone to be changes can freely be selected by varying the Bi/Cr compsn. ratio. The title material is suited for use in displays for warning overheat of a stove or the like.
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