摘要 |
<p>Disclosed is a humidity indicator which contains no heavy metal and has good visibility of a color change that occurs when the humidity is increased. The humidity indicator can be produced by applying an aqueous coating comprising a leuco dye, an acidic compound which is in a solid state at ambient temperature, a deliquescent substance and an aqueous resin emulsion onto a substrate such as a resin film, a nonwoven fabric or a paper, and heating and drying the resulting product.</p> |