HUMIDITY DETECTION MATERIAL

摘要

PROBLEM TO BE SOLVED: To provide a humidity detection material which is made safe to the human body by using no cobalt chloride and can change its color to be identical to the color of cobalt chloride. SOLUTION: An indicator is carried by a silica gel, which changes its color to be blue in its dry state, and to red or pink in its moisture state in order to identify a dry condition or a moisture condition. Safranine being an organic coloring matter is preferably used as the indicator. The safranine is carried such that its concentration ranges from 20 ppm to 200 ppm. The cobalt chloride can be replaced thereby with out varying any conventional recognition of the color change caused by the cobalt chloride, and a user can use it without feeling odd. COPYRIGHT: (C)2007,JPO&INPIT