| 摘要 |
The invention provides a bleaching composition of pH 8-14 which comprises an oxygen transfer agent and hypochlorite or a source thereof and a method for bleaching a stained substrate which comprises the step of treating the substrate with a bleaching composition of pH 8-14 which bleaching composition comprises an oxygen transfer agent and hypochlorite or a source thereof. Particularly preferred oxygen transfer agents are imine quaternary ammonium salts such as N-methyl-3,4-dihydroisoquinolinium salts. Where these salts are used, suitable counter-ions include halides, sulphate, methosulphate, sulphonate, p-toluene sulphonate and phosphate. Oxygen transfer agents which comprise a quaternary nitrogen atom are preferred. In the alternative, the oxygen transfer agent can be a sulphonimine. |
