Biocidal compositions

Abstract

Embodiments of the present subject matter provide a biocidal composition comprising an aqueous mixture of (a) a phosphonium compound and (b) a polymeric ammonium compound, wherein the weight ratio of compound (a) to compound (b) is from 0.2:1 to 20:1, and wherein the phosphonium compound (a) has formula: ##STR00001## wherein each R is independently a C.sub.1-C.sub.6 alkyl group which is unsubstituted or substituted by a cyano, hydroxyl, esterified hydroxyl or aryl group; R.sup.1 represents a C.sub.8-C.sub.18 alkyl group which is substituted or unsubstituted; and X represents either chlorine or bromine; and wherein the polymeric ammonium compound (b) comprises the repeat unit: ##STR00002## wherein each R.sup.2 is independently a C.sub.1-C.sub.2 alkyl group which is substituted or unsubstituted; R.sup.3 represents a C.sub.2-C.sub.18 alkyl or alkenyl group which is substituted or unsubstituted; and R.sup.4 represents a C.sub.2-C.sub.18 alkyl or alkenyl group which is substituted or unsubstituted, a diethyl ether group, an isopropanol group, a N,N-dipropylurea group, or a 2-butene group. In some embodiments, the biocidal composition has a synergy index (SI) of less than 1 in relation to the effect of the composition on the inhibition of growth of biological organisms.

Claims

1. A biocidal composition comprising an aqueous mixture of (a) a phosphonium compound and (b) a polymeric ammonium compound; wherein the weight ratio of compound (a) to compound (b) is from 0.5:1 to 5:1; and wherein the phosphonium compound (a) is tri n-butyl n-tetradecyl phosphonium chloride (hereinafter TTPC); and wherein the polymeric ammonium compound (b) has formula: ##STR00018## wherein each R.sup.2 is independently a methyl group; R.sup.3 represents a C.sub.2 alkyl group; R.sup.4 represents a diethyl ether group or an isopropanol group; X.sup.1 represents chlorine; and n is 2-40; and wherein the composition comprises an amphoteric surfactant.

2. A composition according to claim 1, wherein compound (b) is Poly[oxyethylene(dimethylimino)ethylene(dimethylimino)ethylene dichloride] (hereafter polyquat).

3. The composition according to claim 1, wherein the weight ratio of compound (a) to compound (b) is from 1:1 to 2:1.

4. A composition according to claim 1, wherein the biocidal composition has a synergy index (SI) of less than 1 in relation to the effect of the composition on the inhibition of growth of Pseudomonas aeruginosa bacteria, wherein the synergy index is determined by:
Q.sub.a/Q.sub.A+Q.sub.b/Q.sub.B=synergy index(SI) wherein: Q.sub.A=quantity of compound (a), acting alone, producing an end point Q.sub.B=quantity of compound (b), acting alone, producing an end point Q.sub.a=quantity of compound (a) in mixture, producing an end point Q.sub.b=quantity of compound (b) in mixture, producing an end point.

5. A composition according to claim 1, wherein the composition comprises compound (a) and compound (b) in a combined amount of between 1% and 100% by weight of the composition.

6. A method of treating an aqueous system to inhibit growth of one or more micro-organisms therein; wherein the method comprises adding (a) a phosphonium compound and (b) a polymeric ammonium compound to an aqueous system such that the weight ratio of compound (a) to compound (b) is from 0.5:1 to 5:1; and wherein the phosphonium compound (a) is tri n-butyl n-tetradecyl phosphonium chloride (hereinafter TTPC); and wherein the polymeric ammonium compound (b) has formula: ##STR00019## wherein each R.sup.2 is independently a methyl group; R.sup.3 represents a C.sub.2 alkyl group; R.sup.4 represents a diethyl ether group or an isopropanol group; X.sup.1 represents chlorine; and n is 2-40; and wherein the method comprises adding an amphoteric surfactant.

7. The method according to claim 6, wherein compound (b) is Poly[oxyethylene(dimethylimino)ethylene(dimethylimino)ethylene dichloride] (hereafter polyquat).

8. The method according to claim 6, wherein the weight ratio of compound (a) to compound (b) is from 1:1 to 2:1.

9. The method according to claim 6 wherein the method comprises adding compound (a) and compound (b) to the aqueous system such that they are present in a combined amount of from 0.05 to 200 parts by weight per one million parts by weight of said aqueous system.

10. The method according to claim 6, wherein the method comprises: adding a biocidal composition comprising an aqueous mixture of (a) the phosphonium compound and (b) the polymeric ammonium compound to the aqueous system wherein the weight ratio of compound (a) to compound (b) in the biocidal composition is from 0.5:1 to 5:1.

11. The method according to claim 6, wherein the method comprises a method of controlling the growth of Pseudomonas aeruginosa bacteria and/or Chlorella vulgaris algae in an aqueous system.

12. A method according to claim 6, wherein the aqueous system comprises a cooling water system, a pulping and/or papermaking water system or an oil and/or gas field water system.

13. An apparatus comprising an aqueous system which comprises (a) a phosphonium compound and (b) a polymeric ammonium compound; wherein the weight ratio of compound (a) to compound (b) is from 0.5:1 to 5:1; and wherein the phosphonium compound (a) is tri n-butyl n-tetradecyl phosphonium chloride (hereinafter TTPC); and wherein the polymeric ammonium compound (b) has formula: ##STR00020## wherein each R.sup.2 is independently a methyl group; R.sup.3 represents a C.sub.2 alkyl group; R.sup.4 represents a diethyl ether group or an isopropanol group; X.sup.1 represents chlorine; and n is 2-40; and wherein the aqueous system comprises an amphoteric surfactant.

14. The apparatus of claim 13, wherein compound compound (b) is Poly[oxyethylene(dimethylimino)ethylene(dimethylimino)ethylene dichloride] (hereafter polyquat).

15. The apparatus of claim 13 wherein the weight ratio of compound (a) to compound (b) is from 1:1 to 2:1.

16. The apparatus of claim 13 wherein the aqueous system comprises compound (a) and compound (b) in a combined amount of from 0.05 to 200 parts by weight per one million parts by weight of said aqueous system.

17. The apparatus according to claim 13, wherein the aqueous system comprises a biocidal composition comprising an aqueous mixture of (a) the phosphonium compound and (b) the polymeric ammonium compound wherein the weight ratio of compound (a) to compound (b) in the biocidal composition is from 0.5:1 to 5:1.

18. The apparatus of claim 13, wherein the apparatus comprises a cooling apparatus, pulping and/or papermaking apparatus or oil and/or gas field apparatus.

19. A composition according to claim 1, wherein the amphoteric surfactant is selected from the group consisting of alkyl ampho- or iminocarboxylate amphoteric surfactants and alkyl ampho- or iminodicarboxylate amphoteric surfactants.

20. A composition according to claim 1, wherein the amphoteric surfactant is selected from the group consisting of alkyl iminodipropionate amphoteric surfactants.

21. A composition according to claim 20, wherein the biocidal composition comprises an alkyl iminodipropionate amphoteric surfactant in an amount of between 0.3% and 35% by weight.

22. A method according to claim 6, wherein the amphoteric surfactant is selected from the group consisting of alkyl ampho- or iminocarboxylate amphoteric surfactants and alkyl ampho- or iminodicarboxylate amphoteric surfactants.

23. A method according to claim 6, wherein the amphoteric surfactant is selected from the group consisting of alkyl iminodipropionate amphoteric surfactants.

24. An apparatus according to claim 13, wherein the amphoteric surfactant is selected from the group consisting of alkyl ampho- or iminocarboxylate amphoteric surfactants and alkyl ampho- or iminodicarboxylate amphoteric surfactants.

25. An apparatus according to claim 13, wherein the amphoteric surfactant is selected from the group consisting of alkyl iminodipropionate amphoteric surfactants.

Description

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(1) The present invention will now be illustrated by way of example with reference to the following preferred embodiments.

(2) Synergy

(3) The exemplified embodiments illustrate the synergistic relationship obtained with the biocidal compositions of the present invention. Synergy was determined by the industry accepted method described by S. C. Kull et al. in Applied Microbiology, vol. 9, pages 538-541 (1961) using the relationship:
Q.sub.a/Q.sub.A+Q.sub.b/Q.sub.B=synergy index

(4) Where:

(5) Q.sub.A=quantity of composition A, acting alone, producing an end point

(6) Q.sub.B=quantity of composition B, acting alone, producing an end point

(7) Q.sub.a=quantity of composition A in mixture, producing an end point

(8) Q.sub.b=quantity of composition B in mixture, producing an end point <1, it indicates synergy

(9) If the synergy index (SI) is: 1, it indicates additivity >1, it indicates antagonism

Example 1

(10) A suspension of Pseudomonas aeruginosa bacteria containing from 3-510.sup.6 cells/mL was prepared in pH 8.5 phosphate buffer. Aliquots of this suspension were dosed with the indicated concentrations of the different compositions with the concentrations being measured as ppm by weight of the stated composition in the dosed suspension. At the designated contact times, each aliquot was sampled to determine the total number of viable organisms in colony forming units per milliliter (CFU/mL) on plate count agar. An endpoint of 1 or 4 log.sub.10 reduction in viable organisms was then selected for calculating synergy.

(11) The following formulations (compositions C and D) according to the invention were prepared from:

(12) Bellacide 350 (an aqueous composition of tri n-butyl n-tetradecyl phosphonium chloride (hereafter TTPC) and water consisting of water and 50% by weight of TTPC) (composition A);

(13) WSCP (an aqueous composition of poly[oxyethylene(dimethyliminio)ethylene(dimethyliminio)ethylene dichloride] (hereafter poyquat) and water consisting of water and 60% by weight of polyquat); (composition B); and water

(14) The components were added sequentially in the proper amounts to yield the desired formulation starting with TTPC followed by polyquat and then water and were gently mixed to form a homogenous mixture.

(15) Formulations:
Composition C (ratio A:B=4:1)

(16) 4 parts by weight composition A

(17) 1 part by weight composition B

(18) 5 parts by weight water
Composition D (ratio A:B=1.5:1)

(19) 3 parts by weight composition A

(20) 2 parts by weight composition B

(21) 5 parts by weight water

(22) Activity of Compositions A to D Against Pseudomonas aeruginosa

(23) TABLE-US-00001 Log.sub.10 Reduction Composition Concentration, ppm 1 hour 3 hours 6 hours A 1.0 0 1.1 3.3 2.0 1.1 4.7 5.3 4.0 1.0 6.2 6.2 8.0 0.7 6.2 6.2 B 0.8 0.1 1.0 2.1 1.7 0.8 2.1 4.1 3.3 1.5 6.2 6.2 6.7 1.2 6.2 6.2 C 1.9 1.2 3.3 4.3 3.8 1.1 3.9 5.3 7.7 4.2 6.2 6.2 15.4 4.0 6.2 6.2 D 1.9 2.0 5.0 5.0 3.7 3.3 5.3 5.3 7.4 5.0 6.2 6.2 14.8 4.6 6.2 6.2

(24) Synergy calculation for composition C:

(25) After one hour of contact time, to achieve 1 log.sub.10 reduction,

(26) Q.sub.A=2 (ppm A alone)

(27) Q.sub.B=3.3 (ppm B alone)

(28) Q.sub.a=0.76 (ppm A in mixture)

(29) Q.sub.b=0.19 (ppm B in mixture)
SI=0.76/2+0.19/3.3=0.44

(30) Synergy calculation for composition D:

(31) After one hour of contact time, to achieve a 1 log.sub.10 reduction,

(32) Q.sub.A=2 (ppm A alone)

(33) Q.sub.B=3.3 (ppm B alone)

(34) Q.sub.a=0.57 (ppm A in mixture)

(35) Q.sub.b=0.38 (ppm B in mixture)
SI=0.57/2+0.38/3.3=0.41

Example 2

(36) A suspension of Pseudomonas aeruginosa bacteria was prepared, dosed and sampled as described in Example 1. An endpoint of 1 or 4 log.sub.10 reduction in viable organisms was selected for calculating synergy.

(37) The following formulations (products E to H) according to the invention were prepared from: Bellacide 350 (an aqueous composition of tri n-butyl n-tetradecyl phosphonium chloride (hereafter TTPC) and water consisting of water and 50% by weight of TTPC) (composition A);

(38) WSCP (an aqueous composition of poly[oxyethylene(dimethyliminio)ethylene(dimethyliminio)ethylene dichloride] (hereafter poyquat) and water consisting of water and 60% by weight of polyquat) (composition B);

(39) a hydrotrope composition consisting of an aqueous mixture of water and 70% by weight of alkyl iminodiopropionate amphoteric surfactant; and

(40) water.
Composition E (ratio A:B=4:1)

(41) 4 parts by weight composition A

(42) 1 part by weight composition B

(43) 1.82 parts by weight hydrotrope composition

(44) 3.18 parts by weight water
Composition F (ratio A:B=1.5:1)

(45) 3 parts by weight composition A

(46) 2 parts by weight composition B

(47) 1.96 parts by weight hydrotrope composition

(48) 3.04 parts by weight water
Composition G (ratio A:B=1:1)

(49) 2.5 parts by weight composition A

(50) 2.5 parts by weight composition B

(51) 2.1 parts by weight hydrotrope composition

(52) 2.9 parts by weight water
Composition H (ratio A:B=1:1)

(53) 3.3 parts by weight composition A

(54) 3.3 parts by weight composition B

(55) 3.4 parts by weight hydrotrope composition

(56) Activity of compositions A and B and E to H against Pseudomonas aeruginosa

(57) TABLE-US-00002 Log.sub.10 Reduction Composition Concentration, ppm 1 hour 3 hours 6 hours A 1.0 0.1 0.9 1.8 2.0 0.7 2.9 4.2 4.0 4.1 6.6 6.5 B 0.8 1.4 1.6 1.6 1.7 2.8 3.4 4.2 3.3 4.7 6.6 6.5 E 1.9 4.4 6.6 6.6 3.8 6.6 6.6 6.6 7.7 6.6 6.6 6.6 F 1.9 6.6 6.6 6.6 3.7 6.6 6.6 6.6 7.4 6.6 6.6 6.6 G 1.8 4.7 6.6 6.5 3.6 6.4 6.6 6.5 7.3 6.4 6.6 6.5 H 1.4 4.2 6.6 6.5 2.7 5.4 6.6 6.5 5.5 6.4 6.6 6.5

(58) Synergy calculation for composition E:

(59) After one hour of contact time, to achieve a 4 log.sub.10 reduction,

(60) Q.sub.A=4 (ppm A alone)

(61) Q.sub.B=3.3 (ppm B alone)

(62) Q.sub.a=0.76 (ppm A in mixture)

(63) Q.sub.b=0.19 (ppm B in mixture)
SI=0.76/4+0.19/3.3=0.25

(64) Synergy calculation for composition F:

(65) After one hour of contact time, to achieve a 4 log.sub.10 reduction,

(66) Q.sub.A=4 (ppm A alone)

(67) Q.sub.B=3.3 (ppm B alone)

(68) Q.sub.a=0.57 (ppm A in mixture)

(69) Q.sub.b=0.38 (ppm B in mixture)
SI=0.57/4+0.38/3.3=0.26

(70) Synergy calculation for composition G:

(71) After one hour of contact time, to achieve a 4 log.sub.10 reduction,

(72) Q.sub.A=4 (ppm A alone)

(73) Q.sub.B=3.3 (ppm B alone)

(74) Q.sub.a=0.45 (ppm A in mixture)

(75) Q.sub.b=0.45 (ppm B in mixture)
S1=0.45/4+0.45/3.3=0.25

(76) Synergy calculation for composition H:

(77) After one hour of contact time, to achieve a 4 log.sub.10 reduction,

(78) Q.sub.A=4 (ppm A alone)

(79) Q.sub.B=3.3 (ppm B alone)

(80) Q.sub.a=0.47 (ppm A in mixture)

(81) Q.sub.b=0.47 (ppm B in mixture)
SI=0.47/4+0.47/3.3=0.26

Example 3

(82) A suspension of Chlorella vulgaris algae that had an absorbance of 0.5 at 450 nm was prepared in pH 8.5 Allen's media. This gives the appropriate number of algae cells per milliliter for the biocide challenge test. One hundred and fifty microliters of this suspension was placed into each well of a 96 well tissue culture plate. The first well in each row was dosed with the desired amount of the indicated product and the final volume was brought up to 300 microliters using the algae suspension. Serial two fold dilutions were then made down each row. The plates were incubated under cool white lights for 12 days and then the minimum inhibitory concentration was determined. Synergy was calculated based on a comparison of the minimum inhibitory concentration achieved by each composition.

(83) Activity of compositions A and B and E to H against Chlorella vulgaris

Minimum Inhibitory Concentration (in ppm)

EvaluationTest Rows

(84) TABLE-US-00003 Composition 1 2 Average A 4 4 4 B 6.7 13.3 10 E 15.4 15.4 15.4 F 29.6 14.8 22.2 G 29 1629 29 H 21.8 21.8 21.8

(85) Synergy calculation for composition E:

(86) Q.sub.A=4 (ppm A alone)

(87) Q.sub.B=10 (ppm B alone)

(88) Q.sub.a=6.2 (ppm A in mixture)

(89) Q.sub.b=1.5 (ppm B in mixture)
SI=6.2/4+1.5/10=1.70

(90) Synergy calculation for composition F:

(91) Q.sub.A=4 (ppm A alone)

(92) Q.sub.B=10 (ppm B alone)

(93) Q.sub.a=6.3 (ppm A in mixture)

(94) Q.sub.b=4.4 (ppm B in mixture)
SI=6.3/4+4.4/10=2.02

(95) Synergy calculation for composition G:

(96) Q.sub.A=4 (ppm A alone)

(97) Q.sub.B=10 (ppm B alone)

(98) Q.sub.a=7.3 (ppm A in mixture)

(99) Q.sub.b=7.3 (ppm B in mixture)
S1=7.314+7.3/10=2.56

(100) Synergy calculation for composition H:

(101) Q.sub.A=4 (ppm A alone)

(102) Q.sub.B=10 (ppm B alone)

(103) Q.sub.a=7.3 (ppm A in mixture)

(104) Q.sub.b=7.3 (ppm B in mixture)
SI=7.3/4+7.3/10=2.56

(105) It can be seen from Example 3 that the testedcompositions did not show synergy in relation to inhibition of growth of Chlorella vulgaris algae. However compositions that did not exhibit synergy in relation to inhibition of growth of Chlorella vulgaris algae remained effective against such growth and also exhibited significant synergy in relation to growth of Pseudomonas aeruginosa bacteria as illustrated by Example 2.

(106) It will be appreciated that preferred embodiments of the present invention may prove particularly effective in treating water systems and in particular in inhibiting growth of organisms such as Pseudomonas aeruginosa bacteria. Compositions in which the ratio of TTPC:polyquat is selected to be around 1.5:1 may be particularly effective against both Chlorella vulgaris algae and Pseudomonas aeruginosa bacteria.