Substituted benzonitriles and compositions useful for bleaching
Reference Number: N 03-07
Inventors: Deline, James E.; Arbogast, James W.; Foland, Lafayette D.; Smith, William L.
Invention SummaryIt is an object of the present invention to provide activator compounds useful for bleaching applications.
In one aspect of the present invention a composition, useful for bleaching, comprises a substituted benzonitrile as an activator compound. The composition further includes a peroxygen source in a sufficient amount to form an oxidizing agent derivative of the activator compound when the peroxygen source and the activator compound are admixed in a solvent therefore. The solvent will typically be aqueous based, such as in laundry (washing machine) applications. The oxidizing agent derivative is thought to be a peroxyimidic acid. The peroxygen source preferably is in an amount that provides peroxygen in a molar ratio with respect to activator compound of about 1:1 or greater.
The composition preferably includes a pH adjusting agent and/or a metal sequestering agent. The pH adjusting agent, when present, is effective to adjust or to maintain the pH of a solution in which the oxidizing agent is intended to be dissolved, preferably an aqueous based solution, to a pH greater than about 8. The metal sequestering agent, when present, preferably includes a phosphonate, amino phosphates, or a mixture thereof.
Embodiments of the invention are benzonitriles with one or a plurality of cyano groups. When an embodiment has one cyano group, then there are also two other electron withdrawing groups unless the embodiment has a quaternary ammonium substituent such as ##STR1## (where R.sub.1, R.sub.2 and R.sub.3 are C.sub.1-20 alkyl, and more preferably C.sub.1-4 alkyl). In the instance of a quaternary ammonium substituent, then that substituent itself is a sufficient electron-withdrawing group so it may be the sole substituent (in addition to the cyano group). When there are a plurality of cyano groups, then the embodiment has at least one additional electron-withdrawing group.
A particularly preferred embodiment of the invention is 3,5-dinitrobenzonitrile, which gives excellent bleaching performance on oxidant sensitive stains. For all embodiments, the electron-withdrawing groups are believed to activate the nitrile portion of the molecule to react with peroxygen and to form an oxidizing agent derivative in aqueous solutions such as in laundry applications.
When practicing the invention in bleaching compositions, then bleaching power comparable to sodium hypochlorite on some stains with some embodiments of the inventive activators can be achieved.