Patent · US Expired

Process for isolating sulphur dyestuffs from aqueous crude melts containing sodium polysulphide

US4309178A · kind A · utility

0Cited by

3References

7Claims

0Family size

Assignee

Cassella Aktiengesellschaft · DE

Inventors

Georg Daniek · Frankfurt am Main, DE
Artur Meyer · Schöneck, DE
Wolf Weidemuller · Frankfurt am Main, DE

Key dates

Filing date	Oct 17, 1980
Grant date	Jan 5, 1982
Priority date	—
Expiry date	Oct 17, 2000

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC09B67/0096
WIPO fieldBasic materials chemistry
WIPO sectorChemistry

Abstract

In the processs for isolating solid sulphur dyestuffs from crude sulphur dyestuff melts, the improvement comprises adding 10.sup.-4 to 1% by weight, relative to the amount of dyestuff, of an organic flocculating auxiliary to the crude dyestuff melt to produce a filterable dyestuff precipitate and then separating said precipitate.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.