Method of continuously removing and obtaining ethylene diamine tetracetic acid (EDTA) from the process water of electroless copper plating
US5091070A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 30, 1990 |
| Grant date | Feb 25, 1992 |
| Priority date | — |
| Expiry date | Aug 30, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S204/13
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
The invention relates to a method of continuously removing and obtaining ethylene diamine tetracetic acid (EDTA) from the process water of electroless copper plating. For that purpose the process water containing the EDTA is directed into an electrodialysis cell alternatingly equipped with bipolar membranes and anion exchange membranes and/or cation exchange membranes, and to which a potential difference is applied. The EDTA is converted into its charge-neutral form by means of protonation, and the protons required for that purpose are generated via bipolar membranes through electrodialysis. The required pH-value is adjusted by a pH-controlled electric field regulation via the bipolar membranes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.