Formulations with unexpected cleaning performance incorporating a biodegradable chelant
A chelating composition suitable for low-temperature use or storage is disclosed. The chelating compositions include 20 to 70 wt. percent of a polar solvent and 30 to 80 wt. percent of a first component of the formula: (I) wherein R is a hydroxyalkyl group and each R′ is individually selected from the group consisting of hydrogen, unsubstituted or inertly substituted alkyl groups, carbonyl-containing alkyl groups, carboxylate-containing alkyl groups, hydroxyalkyl groups and alkoxy groups; R″ is selected from the group consisting of hydrogen, unsubstituted or inertly substituted alkyl groups; carbonyl-substituted alkyl groups, carboxylate-containing alkyl groups, hydroxyalkyl groups and alkoxy groups; M 1 and M 2 are alkali metal ions, wherein the M 1 has a higher atomic weight than M 2 ; wherein x+y=n and the mole fraction of M1 is greater than 0.70 to 1. Methods of suppressing crystallization and methods of cleaning surfaces employing the compositions described herein are also disclosed.
1. A chelating composition suitable for low-temperature use or storage, comprising:
a) 20 to 70 wt. percent of water; and
b) 30 to 80 wt. percent of a first component, of the formula:
wherein R is a hydroxyalkyl group having from 1 to about 10 carbon atoms;
each R′ is individually selected from the group consisting of hydrogen, unsubstituted or inertly substituted alkyl groups; carbonyl-containing alkyl groups, carboxylate-containing alkyl groups, hydroxyalkyl groups and alkoxy groups;
R″ has from 1 to about 10 carbon atoms and is selected from the group consisting of unsubstituted or inertly substituted alkyl groups; carbonyl-substituted alkyl groups, carboxylate-containing alkyl groups, hydroxyalkyl groups and alkoxy groups; or hydrogen;
M 1 and M 2 are individually selected from the group consisting of Na+ and K+, wherein M 1 has a greater atomic weight than M 2 ;
wherein x+y=n and the mole fraction of M 1 is greater than 0.70 up to 1; and
wherein the weight percentages are based on the amounts of the first component and the polar solvent.
2. The composition of claim 1 , wherein less than about 5 weight percent of the composition forms solids after being maintained at −12° C. for at 12 hours.
3. The composition of claim 1 , wherein the first component follows the formula (K + ) x (Na + ) y (HOCH 2 CH 2 N(CH 2 COO) 2 ) −2 ; wherein x+y=2.
4. The composition of claim 3 further comprising a compound of the formula (M 1 + ) x (M 2 + ) y (HOCH 2 CH 2 N(R)(CH 2 COO)) −1 where (R) is hydrogen and wherein the mole fraction of M 1 ranges from greater than 0.80 to 1, and wherein x+y=1.
5. The composition of claim 1 , comprising about 40 to about 70 wt. percent of the first component.
6. The composition of claim 1 , wherein the mole fraction of M 1 ranges from about 0.80 to about 0.95.
7. A method of suppressing crystallization in a chelating solution, comprising mixing the composition of claim 1 with the chelating solution.
8. The method of claim 7 , wherein the first component follows the formula (K + ) x (Na + ) y (HOCH 2 CH 2 N(CH 2 COO) 2 ) −2 ; wherein x+y=2.
9. The method of claim 7 comprising about 40 to about 70 wt. percent of the first component.
10. The method of claim 7 , comprising about 50 to about 60 wt. percent of the first component.