Hypochlorite compositions containing thiosulfate and use thereof
US4908215A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 21, 1988 |
| Grant date | Mar 13, 1990 |
| Priority date | — |
| Expiry date | Nov 21, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC11D2111/14
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
A one step process providing timed exposure to a substantially constant concentration of hypochlorite disinfectant is described, said process being completed when the hypochlorite is destroyed in an autocatalytic reaction with thiosulfate. The hypochlorite lifetime is precisely controlled by adjusting the initial pH of an alkaline disinfection solution of thiosulfate and hypochlorite, said solution containing a molar ratio of between 0.25 and 0.75 moles of thiosulfate to 1.00 mole of hypochlorite. Subsequently, with gradual evolution of acid and decreasing pH, the acid-dependent autocatalytic oxidation of thiosulfate is accelerated. This consumes the hypochlorite in a brief time interval, terminating the disinfection process. Also included in said alkaline disinfection solution is an appropriate concentration of Na.sub.2 HPO.sub.4 or other chemical which is unreactive with hypochlorite and allows said initially alkaline pH to substantially decrease, but which later becomes a functioning pH buffer, controlling the final pH of the hypochlorite-free, disinfected solution. Completion of the disinfection process which is accompanied by a substantial pH decrease can be visualized by incl…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.