Film-spreading powder for suppressing water evaporation
US6303133A · kind A · utility
Inventor
Key dates
| Filing date | Nov 17, 1998 |
| Grant date | Oct 16, 2001 |
| Priority date | — |
| Expiry date | Nov 17, 2018 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA01G2013/004
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The invention pertains to enhancing the dispersion on the surface of a still or moving body of a polar liquid, such as water, of particles of a powder of the composition essentially comprising a monolayer-forming constituent, such as hexadecanol or octadecanol or a blend thereof, together with a high proportion of a soluble or sparingly soluble alkaline earth metal hydroxide, more particularly about five times the monolayer-forming constituent's weight when the hydroxide constituent is--as preferred for potable water evaporation reduction--calcium hydroxide procured as inexpensive pre-powdered agricultural hydrated lime. A melt-processing manner of producing the composition is described. When particles of the composition contact the body of water, so long as lime remains present in any floating particles, they will be individually positively charged, resulting in their repulsion from one another. This enhanced dispersal effect is due to the ionization of the calcium hydroxide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.