Coating for humidity indicator, method for production of the coating, and humidity indicator using the coating
US8962521B2 · kind B2 · utility
1Cited by
4References
8Claims
0Family size
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Key dates
| Filing date | Apr 25, 2007 |
| Grant date | Feb 24, 2015 |
| Priority date | — |
| Expiry date | Dec 28, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/81
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.