Patent ID: 9689742
Date: 2017-06-27
CPC Classifications: G01J,G01N

Claim:
1. An ultraviolet-sensing sheet which has a change in reflection density ΔD1 of 0.2 or more in a range of cumulative illuminance of 1 mJ/cm 2 or more and less than 10 mJ/cm 2 , a change in reflection density ΔD2 of 0.2 or more in a range of cumulative illuminance of 10 mJ/cm 2 or more and less than 100 mJ/cm 2 , and a change in reflection density ΔD3 of 0.2 or more in a range of cumulative illuminance of 100 mJ/cm 2 or more and 1,000 mJ/cm 2 or less, as measured at a wavelength of 365 nm when the ultraviolet-sensing sheet is irradiated with a high-pressure mercury lamp, wherein the ultraviolet-sensing sheet comprises an ultraviolet-sensing layer comprising a capsule containing a photo-oxidant and a leuco dye capable of developing color by the photo-oxidant; the mass ratio of the photo-oxidant and the leuco dye is 0.3 to 0.8:1; and the leuco dye is present in an amount of 0.3 to 0.8 g per 1 m