Hollow capsule having a wall permeable to water or an aqueous solution
US7179485B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 26, 2001 |
| Grant date | Feb 20, 2007 |
| Priority date | — |
| Expiry date | Nov 6, 2023 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC11D17/0039
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
This invention discloses, as an article of manufacture, a capsule having a hollow interior and an enclosing wall, referred to as a membrane. The membrane is not soluble in water, but is permeable to water or an aqueous solution. The membrane is comprised of a first material and can also include a second material. When the membrane is comprised of the first material and the second material, then it is referred to as a composite material wherein the first material forms sporting matrix having the second material fixed in the matrix. The first material is a urethane/vinyl hybrid polymer and is not soluble in, reactive with or a solvent for the second material. The second material is a particulate solid, different from the first material, and is not soluble in, reactive with or a solvent for the first material. The capsule of this invention is useful to maintain in the hollow interior thereof a solid, water-soluble first chemical composition which is not soluble in, reactive with or a solvent for the enclosing wall of the capsule. In operation, the exterior of the capsule, having the first composition maintained in the interior thereof, is placed in contact with a water-soluble second …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.