Patent ID: 6814909
Filing Date: 2004-11-09
Classification: G09F

Abstract:
A time indicator comprising a porous resin material, and a liquid, which can be evaporated, retained in the pores of said porous resin material, which satisfies the following relationship:W1&gE;80 and (W1âˆ’W2)&gE;20 wherein W1 is a whiteness of the porous resin material, and W2 is a whiteness of the indicator, and wherein said porous resin material comprises a filler and a thermoplastic resin which satisfy the following relationship (1), and is prepared by stretching a molded article made of a composition having a volume percentage of the filler in the range between 15 and 40%, and said liquid satisfies the following relationship (2):(1) a ratio of refractive index of thermoplastic resin to refractive index of filler =0.98-1.02; and (2) a ratio of refractive index of liquid to refractive index of thermoplastic resin=0.867-1.13.