Alkaline light duty dishwashing detergent composition containing an alkyl ethoxy carboxylate surfactant, magnesium ions, chelator and buffer

A light-duty liquid or gel dishwashing detergent composition comprising, by weight:

• (a) from about 5% to 70% of a surfactant mixture comprising, by weight:
• (i) from about 70% to 100% of alkyl ethoxy carboxylates of the formula:
• RO(CH.sub.2 CH.sub.2 O).sub.x CH.sub.2 COO.sup.- M.sup.+
• wherein R is a C.sub.12 to C.sub.16 alkyl group, x ranges from 0 to about 10 and the ethoxylate distribution is such that, on a weight basis, the amount of material where x is 0 is less than about 20% and the amount of material where x is greater than 7 is less than about 25%, the average x is from about 2 to 4 when the average R is C.sub.13 or less, and the average x is from about 3 to 6 when the average R is greater than C.sub.13, and M is a cation;
• (ii) from 0% to about 15% of alcohol ethoxylates of the formula:
• RO(CH.sub.2 CH.sub.2 O).sub.x H
• wherein R is a C.sub.12 to C.sub.16 alkyl group and x ranges from 0 to about 10 and the average x is less than about 6;
• and
• (iii) from 0% to about 15% of soaps of the formula:
• RCOO.sup.- M.sup.+
• wherein R is a C.sub.11 to C.sub.15 alkyl group and M is a cation;
• (b) from about 0.1% to about 3% of magnesium ions;
• (c) a magnesium chelating agent which forms a soluble magnesium complex, having a log of formation constant, log K.sub.f, between about 1 and about 3.5;
• the agent being selected from the group consisting of sarcosine (N-methylglycine), bicine (bis(2-ethanol) glycine), N-2-hydroxyethyl iminodiacetic acid, N-(2,3-dihyroxypropyl) iminodiacetic acid, their alkali metal salts, and mixtures thereof, in an amount sufficient to prevent the formation of Mg(OH).sub.2 precipitates in the composition;
• and
• (d) sufficient alkalinity buffering agent selected from the group consisting of 2 amino-2-ethyl-1,3-propanediol, 2-amino-2-methyl propanol, 2-amino-2-methyl-1,3-propanediol, tris-(hydroxymethyl) aminoethane, disodium glutamate, N-methyl diethanolamine, 1,3-diamino-2-propanol, N,N'-tetramethyl-1,3-diamino-2-propanol, N tris (hydroxymethyl) methyl glycine and mixtures thereof to maintain the pH of the composition between about 8 and 10 when diluted with water to about 0.1% to 0.4%, by weight.