National Research Laboratories

Sudhir K Shringarpurey

Gerald L Maurer

A method of transporting metal ions by introducing a metal complex into a medium containing a moiety which demands the metal ion and the complex releases the ions in a controlled manner upon demand. The metal complexes have an aqueous proton induced dissociation property represented by a sigmoidally-shaped curve on a cartesian coordinate plot of the negative log of the metal ion concentration versus the negative log of hydrogen ion concentration. This dissociation property causes a controlled release of metal ion into mediums containing a reacting moiety upon demand for the metal ion. For example, metalworking emulsions of oil and water are stabilized by the addition thereto of minor amounts of a metal complex, e.g., disodium monocopper(II) citrate, which at alkaline pH metalworking conditions above about 7 to about 9 releases metal cations to the emulsions imparting stabilizing characteristics which prevent emulsion degradation by a number of factors commonly encountered in metalworking operations. Also, the method is effective in the controlled release of metal ions in the normal range of physiological pH, i.e., about 4 to 9, for growth controlling action against microorganisms including bacteria, fungi and viruses.

Method of transporting metal ions

Stabilized metalworking fluid compositions are disclosed comprising an oil and water dispersion and, as a stabilizer therefor, a metal complex of a metal ion and a polyfunctional organic ligand. The metal complexes have an aqueous proton induced dissociation property represented by a sigmoidally-shaped curve on a cartesian coordinate plot of the negative log of the metal ion concentration versus the negative log of hydrogen ion concentration. This dissociation property causes a controlled release of metal ion into the oil and water dispersion to impart metal working stability to the dispersion. Metal working emulsions of oil and water are stabilized by the addition thereto of minor amounts of a metal complex, e.g., disodium monocopper(II) citrate, which at alkaline pH metalworking conditions above about 7 to about 9 releases metal cations to the emulsions imparting stabilizing characteristics which prevent emulsion degradation by a number of factors commonly encountered in metalworking operations. The stabilized compositions of this invention have greatly improved service life and offer significant economies in metalworking operations.

Metalworking fluid compositions and methods of stabilizing same

Antimicrobial agents are disclosed containing as the active ingredient a metal complex of a metal ion and a polyfunctional organic ligand. The antimicrobial metal complexes are characterized by a very unexpected aqueous proton induced dissociation property which causes the controlled release of toxic metal ion at a pH compatible with microorganism growth. This dissociation property is represented by a sigmoidally shaped curve, i.e., one curved in two different directions like the letter 'S,' on a cartesian coordinate plot of the negative logarithm (log) of metal ion concentration versus the negative logarithm (log) of hydrogen ion concentration (or otherwise known as a pM-pH diagram). Antimicrobial metal complexes are also disclosed which are extremely effective in the controlled release of metal ion from the complex in about the normal range of physiological pH, i.e., about 10.sup.- 4 to 10.sup.-9 moles of hydrogen ion per liter.

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Cincinnati, OH, United States of America

Sudhir K Shringarpurey