Method of treating spent dryfilm stripping and developing solutions with a chemical mixture
US4999114A · kind A · utility
12Cited by
9References
1Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Feb 16, 1990 |
| Grant date | Mar 12, 1991 |
| Priority date | — |
| Expiry date | Feb 16, 2010 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F2103/40
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A chemical mixture for treating spent dryfilm stripper and developer solutions by mixing the spent solutions with a solution of aluminum sulfate and borax in controlled amounts causing a surface absorption reaction which results in a slurry of a non-sticky, benign precipitate in a supernatant liquid. The supernatant liquid contains the dissolved heavy metals. The non-sticky precipitate does not interfere with the ph measurement which indicates when the reaction is complete, and the benign precipitate can be filtered out for disposal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.