An indicator comprising a porous resin material, and a liquid retained in the pores of the porous resin material, in which the whiteness of the porous resin material is at least 80, and the whiteness of the porous resin material is at least 20 larger than that of the indicator. This indicator displays information such as a period through the change of a color tone, and the like, well maintains the displaying properties, and suffers from less variation of displayed periods.
This application claims the benefit under 35 U.S.C. .sctn.371 of prior PCT International Application No. PCT/JP95/02028, which has an International filing date of Oct. 4, 1995, which designated the United States of America, the entire contents of which are hereby incorporated by references.
7472667 - Period indicator - Owned by Sumitomo Chemical Co., Ltd. (Osaka,JP) Nippon Paper Papylia Company, Limited (Shizuoka,JP)
A period indicator including a liquid-permeable substrate and an indicative section which is overlaid on a portion of the substrate and which is formed from a liquid-permeable material having a low light refractive index, the indicator containing a volatile liquid, wherein the indicative section is formed by coating a surface of the substrate with an indicative-section-forming material prepared by mixing a binder and finely divided particulate matter having a low light refractive index, the indicative section is composed of two or more regions, and the regions differ in height from one another as measured from the surface of the substrate, as the coating amounts per unit area of the indicative section forming material in respective regions differ from one another. Since the period indicator can indicate the chemical-containing state stepwise, it is useful for indicating the available period of use of a chemical such as a mothproofing agent, an insecticide, a deodorant, or a fragrance.
