Synergistic antimicrobial or biocidal mixtures including isothiazolones
AssigneeBoard of Governors of Wayne State University
InventorHarold W. Rossmoore
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Abstract
Antimicrobial mixtures of isothiazolones and a metal complex with a polyfunctional ligand which are synergistic are described. The mixtures particularly include mixtures of a monocopper disodium citrate as the ligand and a 5-x-2-lower alkyl 4-isothiazolin-3-one wherein x is a halo or hydrogen group as the isothiazolone. The compositions are particularly useful for metal cutting fluids wherein long duration antimicrobial activity is desired.
Claims23
A concentrated composition which comprises in admixture:
- (a) a heavy metal complex of a polyfunctional organic ligand(A);
- and
- (b) an isothiazolone or isothiazolones (B), wherein the isothiazolone(s) (B) is present in an amount with the metal complex (A) which is less than is required for biocidal activity alone in a fluid which supports microbial growth, wherein the metal complex provides a metal ion in the fluid which is toxic to microbial growth with the isothiazolone(s) and wherein between 1.5 and 500 ppm of metal ion is provided in the fluid from the metal complex and wherein the microbial growth in the fluid is suppressed for over 50 hours in the presence of ferric ion.
A biocidal metal working composition which comprises in admixture:
- (a) a metal working fluid in admixture with a biocidal amount of
- (b) a heavy metal complex of a polyfunctional ligand (A) and an isothiazolone or isothiazolones (B), wherein the isothiazolones(s) (B) is present in an amount with the metal complex (A) which is less than is required for biocidal activity alone in the fluid, wherein the metal complex provides a metal ion in the fluid which is toxic to microbial growth with the isothiazolone(s), wherein between 1.5 and 500 ppm of metal ion is provided in the fluid from the metal complex and wherein microbial growth is suppressed for over 50 hours in the presence of ferric ion.
A method for producing a fluid having biocidal activity wherein the fluid supports microbial growth which comprises:
- providing a biocidal amount of a heavy metal complex of a polyfunctional organic ligand (A) and an isothiazolone or isothiazolines (B) in the fluid, wherein the isothiazolone(s) (B) is present in an amount which is less than is required for biocidal activity alone in the fluid wherein the metal complex provides a metal ion in the fluid which is toxic to microbial growth with the isothiazolone(s), wherein between 1.5 and 500 ppm of metal ion is provided in the fluid from the metal complex and wherein microbial growth is suppressed for over 50 hours in the presence of ferric ion.
A concentrated composition which comprises in admixture:
- (a) a metal complex consisting essentially of disodium monocopper (II) citrate;
- and
- (b) an isothiazolone mixture consisting essentially of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one;
- and wherein the isothiazolones are present in amount with the metal complex which is less than is required for biocidal activity when the concentrated composition is introduced into a fluid which supports microbial growth, wherein between 1.5 and 500 ppm of copper ion is provided in the fluid from the metal complex and wherein microbial growth is suppressed for over 50 hours in the presence of ferric ion.
A method for producing a fluid having biocidal activity which comprises:
- providing a biocidal amount of a metal complex consisting essentially of disodium monocopper (II) citrate and an isothiazolone mixture consisting essentially of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one in the fluid, wherein between 1.5 and 500 ppm of copper ion is provided in the fluid from the metal complex and wherein microbial growth is suppressed for over 50 hours in the presence of ferric ion.
A biocidal metal working composition which comprises in admixture:
- (a) a metal working fluid in admixture with a biocidal amount of
- (b) a metal complex consisting essentially of disodium monocopper(II) citrate and an isothiazolone mixture consisting essentially of 5-chloro-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one, wherein the isothiazolones are present in an amount which is less than is required for biocidal activity alone in the fluid, wherein between 1.5 and 500 ppm of copper is provided in the fluid from the metal complex and wherein microbial growth is suppressed for over 50 hours in the presence of ferric ion.
Dependencies are inferred from the claim text.