Process for reducing propylene chlorohydrin in hydroxypropylated products
US10626192B2 · kind B2 · utility
0Cited by
7References
18Claims
0Family size
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Key dates
| Filing date | May 2, 2017 |
| Grant date | Apr 21, 2020 |
| Priority date | — |
| Expiry date | Oct 12, 2037 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N30/7206
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method of reducing the amount propylene chlorohydrin produced in a reaction to make a hydroxypropylated/crosslinked starch comprising removing residual propylene oxide from alkaline slurry. The residual propylene oxide is removed by the dewatering the alkaline slurry or by washing the starch in slurry at a pH of around 10. The starch is then neutralized in an acid solution and recovered from the second slurry and may or may not be washed, depending on whether the slurry while at pH around 10 to make a hydroxypropylated/crosslinked starch having less than 1 ppm propylene chlorohydrin.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.