Silver polish formulation containing thiourea
US5958854A · kind A · utility
7Cited by
19References
3Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 5, 1997 |
| Grant date | Sep 28, 1999 |
| Priority date | — |
| Expiry date | Jun 5, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23G1/10
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A chemical cleaning composition for silver- or copper-containing surfaces consists of a water-soluble solid or powder comprising thiourea or a derivative thereof, and is formulated in unit application form, e.g. in tablet or sachet form. A preferred composition comprises up to 60% thiourea or a derivative thereof; up to 4% surfactant; not more than 40% acidifier; less than 20% disintegrant; up to 10% binder; 0-1% lubricant; and up to 40% diluent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.