Reversible microcapsule filter cake
US9656233B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 16, 2015 |
| Grant date | May 23, 2017 |
| Priority date | — |
| Expiry date | May 23, 2035 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E60/14
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
The invention teaches a method of efficiently dewatering a microcapsule slurry to form a water re-suspendable filter cake of microcapsules. The process comprises providing an aqueous slurry of microcapsules dispersed in an aqueous solution; adding an agglomeration agent and dispersing the agglomeration agent into the aqueous slurry; adjusting the pH to a pH level sufficient to agglomerate the dispersed microcapsules; and filtering the aqueous slurry of microcapsules by gravity, vacuum or pressure filtration to thereby form a filter cake of dewatered microcapsules. The agglomeration agent is sodium polyphosphate, sodium tetrapolyphosphate, sodium hexametaphosphate, and/or sodium tripolyphosphate; or with anionic microcapsules or coatings even alkaline earth metal salts such as magnesium chloride, calcium chloride or barium chloride, or even aluminum salt such as aluminum chloride.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.