Compositions of dibromomalonamide and their use as biocides

Abstract

A biocidal composition comprising a synergistic ratio of 2,2-dibromomalonamide and hydroxymethyl-substituted phosphorus compound, and its use for the control of microorganisms in aqueous and water-containing systems.

Claims

1. A biocidal composition comprising a synergistic blend of 2,2-dibromomalonamide and tetrakis(hydroxymethyl)phosphonium sulfate wherein the weight ratio of 2,2-dibromomalonamide to the tetrakis(hydroxymethyl)phosphonium sulfate is between 1:4 and 1:16 and further wherein the synergistic blend is synergistically effective against anaerobic bacteria.

2. The biocidal composition according to claim 1 which is: paint, coating, aqueous emulsion, latex, adhesive, ink, pigment dispersion, household or industrial cleaner, detergent, dish detergent, mineral slurry polymer emulsion, caulk, adhesive, tape joint compound, disinfectant, sanitizer, metalworking fluid, construction product, personal care product, textile fluid, spin finish, industrial process water, oil and gas field injection/fracturing, flowback and produced water and fluids as well as functional fluids, fuel, air washer, wastewater, ballast water, filtration systems, swimming pool or spa water.

3. A method for controlling microorganism growth and metabolic activities in an aqueous or water-containing system, the method comprising treating the aqueous or water-containing system with an effective amount of a composition according to claim 1.

4. The method according to claim 3 wherein the aqueous or water-containing system is paint, coating, aqueous emulsion, latex, adhesive, ink, pigment dispersion, household or industrial cleaner, detergent, dish detergent, mineral slurry polymer emulsion, caulk, adhesive, tape joint compound, disinfectant, sanitizer, metalworking fluid, construction product, personal care product, textile fluid, spin finish, industrial process water, oil and gas field injection/fracturing, flowback and produced water and fluids as well as functional fluids, fuel, air washer, wastewater, ballast water, filtration system, swimming pool or spa water.

Description

EXAMPLES

(1) The synergism of the biocides combination of the present invention was determined using the method described by Kull, F. C, et al. in Applied Microbiology 9:538-541 (1961). The formula to calculate the synergistic index (SI) is
Qa/QA+Qb/QB=SI
where
QA=concentration of compound A in ppm, acting alone produced an end point or if end point could not be established, the highest concentration tested will be used the as the end point for the calculation and the SI will be recorded in less than or < values
Qa=concentration of compound A in ppm, in the mixture, which produced an end point
QB=concentration of compound B in ppm, acting alone produced an end point or if end point could not be established, the highest concentration tested will be used the as the end point for the calculation and the SI will be recorded in less than or < values
Qb=concentration of compound B in ppm, in the mixture, which produced an end point Synergism within two biocides is demonstrated when the SI has a value less than 1. The mixtures showed an additive effect if SI is equal to 1 and antagonistic if SI is greater than 1.

Example 1: Synergistic Effect of DBMAL and THPS

Blends Against Anaerobic Bacteria24 Hour Contact Time

(2) Inside an anaerobic chamber (Bactron anaerobic chamber), a deoxygenated sterile salt solution (3.1183 g of NaCl, 1.3082 mg of NaHCO.sub.3, 47.70 mg of KCl, 72.00 mg of CaCl.sub.2, 54.49 mg of MgSO.sub.4, 172.28 mg of Na.sub.2SO.sub.4, 43.92 mg of Na.sub.2CO.sub.3 in 1 L water, pH was adjusted to 7) was inoculated with Desulfovibrio longus ATCC 51456 to a final bacterial concentration of 10.sup.7 to 10.sup.8 CFU/mL. Aliquots of this cell suspension were then treated with DBMAL, THPS, and DBMAL/THPS blends, at selected active concentrations. After the treated cell suspensions were incubated at 40 C. for 24 hours, viable bacteria in each treated and untreated (control) cell suspensions were enumerated using a serial dilution method in Modified Baar's Medium (2.0 g of MgSO.sub.4, 5.7 g of Sodium citrate.2H.sub.2O, 1.0 g of CaSO.sub.4, 1.0 g of NH.sub.4Cl, 3.5 g of Sodium lactate, 1.0 g of Yeast extract, 0.5 g of K.sub.2HPO.sub.4, 0.1 g of Sodium Thioglycolate, 0.02 g of Fe(NH.sub.4).sub.2(SO.sub.4).sub.2, 20 g of NaCl in 1 L deionized water). The biocidal efficacy was determined by minimum tested biocide concentration for bacteria kill in the aliquots (MBC).

(3) Table 1 summarizes the synergistic effect of each biocide and their blends, and the Synergy Index of each combination.

(4) TABLE-US-00001 TABLE 1 Synergistic effect of DBMAL, THPS, and DBMAL/THPS blends against anaerobic bacteria and resulting Synergy Index values Ratio of DBMAL to MBC (ppm active) Synergy THPS (active w/w) DBMAL THPS Index 1:0 200.0 0.0 2:1 100.0 50.0 1.50 1:1 50.0 50.0 1.25 1:2 50.0 100.0 2.25 1:4 6.3 25.0 0.53 1:8 3.3 25.0 0.52 1:16 1.5 25.0 0.51 0:1 0.0 50.0

Example 2: Synergistic Effect of DBMAL and THPS

Blends Against Aerobic Bacteria1 Hour Contact Time

(5) Sterile salt solution (0.2203 g of CaCl.sub.2, 0.1847 g of MgSO.sub.4, and 0.2033 g of NaHCO.sub.3 in 1 L water, adjust pH to 7.4) was inoculated with approximately 10.sup.7 CFU/mL of Pseudomonas aeruginosa ATCC 10145 and Staphylococcus aureus ATCC 6538.

(6) Aliquots of the cell suspension were then treated with DBMAL, THPS, and combinations of these actives at selected concentrations.

(7) After incubating at 37 C. for 1 hr, viable bacteria in each treated and untreated (control) cell suspensions were enumerated using a serial dilution method in Tryptic Soy Broth. The biocidal efficacy was determined by minimum biocide concentration for bacteria kill in the aliquots (MBC). Synergy Index was then calculated. Table 2 summarizes the MBC of each biocide and their blends, and the Synergy Index of each combination.

(8) TABLE-US-00002 TABLE 2 Synergistic effect of DBMAL, THPS, DBMAL/THPS blends against aerobic bacteria in 1 hr contact time and resulting Synergy Index values Ratio of DBMAL to MBC (ppm active) Synergy p value in two THPS (active w/w) DBMAL THPS Index tailed Z-test 1:0 >100.0 9:1 >90.0 >10.0 NA 0 3:1 >75.0 >25.0 NA 0 1:1 >50.0 >50.0 NA 0 1:3 25.0 75.0 <1.00 0 1:9 10.0 90.0 <1.00 0 0:1 0.0 100.0 * P value < 0.05 means that there is significant difference between the Synergy Index and 1

(9) The same test procedure in Example 2 was used to evaluate the biocidal efficacy of DBMAL, THPS and their blends against aerobic bacteria in a 2-hr contact assay. Table 3 summarizes the MBC of each biocide and their blends, and the Synergy Index of each combination.

Example 3: Synergistic Effect of DBMAL and THPS

Blends Against Aerobic Bacteria2 Hour Contact Time

(10) TABLE-US-00003 TABLE 3 Synergistic effect of DBMAL, THPS, and DBMAL/THPS blends agains aerobic bacteria in a 2-hr contact assay and resulting Synergy Index Ratio of DBMAL to MBC (ppm active) Synergy p value in two THPS (active w/w) DBMAL THPS Index tailed Z-test 1:0 77.8 0.0 9:1 95.0 10.6 1.62 3.65 3:1 >37.5 >112.5 >4.29 NA 1:1 >75.0 >75.0 >3.53 NA 1:3 16.7 50.0 1.91 0 1:9 3.0 26.7 0.94 0 0:1 0.0 29.6

(11) As showed in Table 2 and Table 3, DBMAL in combination with THPS at 1:3 to 1:9 active weight ratios are synergistic against aerobic bacteria.

(12) While the invention has been described above according to its preferred embodiments, it can be modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using the general principles disclosed herein. Further, the application is intended to cover such departures from the present disclosure as come within the known or customary practice in the art to which this invention pertains and which fall within the limits of the following claims.