Automatic dishwashing compositions comprising cobalt catalysts
AssigneeThe Procter & Gamble Company
InventorsWilliam Michael Scheper, Christopher Mark Perkins
Life of this patent
Estimating the term…
Loading patent…
AssigneeThe Procter & Gamble Company
InventorsWilliam Michael Scheper, Christopher Mark Perkins
Estimating the term…
Automatic dishwashing detergent compositions comprising certain cobalt catalysts are provided. More specifically, the invention relates to automatic dishwashing detergents which provide enhanced cleaning/bleaching benefits (especially tea stain removal) through the selection of cobalt bleach catalyst having the formula: Co(NH.sub.3).sub.n (M).sub.m (B).sub.b !T.sub.y wherein cobalt is in the +3 oxidation state; n is 4 or 5 (preferably 5); M is one or more ligands coordinated to the cobalt by one site; m is 0, 1 or 2 (preferably 1); B is a ligand coordinated to the cobalt by two sites; b is 0 or 1 (preferably 0), and when b=0, then m+n=6, and when b=l, then m=0 and n=4; and T is one or more appropriately selected counteranions present in a number y, where y is an integer to obtain a charge-balanced salt (preferably y is 1 to 3; most preferably 2 when T is a -1 charged anion); and wherein further said catalyst has a base hydrolysis rate constant of less than 0.23 M.sup.-1 s.sup.-1 (25.degree. C.). Preferred automatic dishwashing compositions comprise amylase and/or protease enzymes. Included are methods for washing tableware in domestic automatic dishwashing appliances using the cobalt catalysts.
An automatic dishwashing composition comprising:
A method for removing tea and coffee stains from tableware, said method comprising treating tea-stained or coffee-stained tableware with an aqueous alkaline bath comprising a source of hydrogen peroxide providing from about 0.015% to about 4.5% available oxygen and from about 0.1 ppm to about 50 ppm of the cobalt bleach catalyst of the formula Co(NH.sub.3).sub.5 OAc!T.sub.y wherein T is one or more counteranions present in a number y, where y is 1 or 2.
Dependencies are inferred from the claim text.