LAUNDRY SANITIZING COMPOSITION

Abstract

Laundry sanitizing composition to provide improved reduction in bacteria during a laundry washing process comprising quaternary ammonium compounds and a C.sub.4-8 organic tricarboxylic hydroxy acid. Also, a method for adding a laundry sanitizing composition to a laundry washing process comprising the steps of adding a dose of from about 30 to about 180 ml of a liquid composition to the fabric softener compartment of an automatic washing machine.

Claims

1. A laundry composition comprising: i. about 0.5 to about 2.5 wt % of at least one cationic biocidal active agent, selected from quaternary ammonium compounds of Formula I: ##STR00010## wherein R.sub.1 and R.sub.2 are independently selected from C.sub.1-C.sub.4 alkyl, C.sub.1-C.sub.4 alkenyl, and C.sub.1-C.sub.4 alkynyl, R.sub.3 and R.sub.4 are independently selected from C.sub.6-C.sub.22 alkyl, C.sub.6-C.sub.22 alkenyl, C.sub.6-C.sub.22 alkynyl, R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are straight-chained or branched, optionally include one or more amide, ether, or ester linkages, and optionally are substituted by a halogen; X is a salt-forming anion which permits water solubility of the quaternary ammonium complex; ii. about 0.3 to about 1.5 wt % of at least one cationic biocidal active agent, selected from quaternary ammonium compounds of Formula II: ##STR00011## wherein R.sub.1 and R.sub.2 are independently selected from C.sub.1-C.sub.4 alkyl, C.sub.1-C.sub.4 alkenyl, and C.sub.1-C.sub.4 alkynyl; R.sub.3 is selected from C.sub.6-C.sub.22 alkyl, C.sub.6-C.sub.22 alkenyl, C.sub.6-C.sub.22 alkynyl; R.sub.1, R.sub.2, and R.sub.3 are straight-chained or branched, optionally include one or more amide, ether, or ester linkages, and optionally are substituted by a halogen; R.sub.4 is a benzyl group, optionally substituted with one or more substituents selected from C.sub.1-C.sub.4 alkyl and halogen; X is a halide or is a methosulfate anion; iii. about 1 to about 25 wt % of at least one C.sub.4-8 organic tricarboxylic acid or a salt thereof.

2. The laundry composition according to claim 1, wherein: i. the at least one cationic biocidal active agent of Formula I is selected from one or more dialkyldimethyl ammonium chlorides, where each alkyl group is independently selected from straight chain C.sub.8-C.sub.10 alkyl; and/or ii. the at least one cationic biocidal active agent of Formula II is selected from one or more alkyl dimethyl benzalkonium chlorides (BKC): ##STR00012## and/or iii. the at least one C.sub.4-8 organic tricarboxylic acid, or a salt thereof, is a C.sub.6 organic tricarboxylic acid or a salt thereof.

3. The laundry composition according to claim 1, wherein the at least one C.sub.4-8 organic tricarboxylic acid or a salt thereof is citric acid or a salt thereof; and/or wherein the at least one C.sub.4-8 organic tricarboxylic acid or the salt thereof is the only organic hydroxy acid or salt thereof in the composition.

4. The laundry composition according to claim 1, wherein the salt-forming cation of the at least one C.sub.4-8 organic tricarboxylic acid is selected from sodium, potassium, magnesium, calcium, aluminium, ammonium, iron or zinc.

5. The laundry composition according to claim 1, comprising: about 1 to about 2 wt % quaternary ammonium compounds of Formula I; about 0.7 to about 1.3 wt % quaternary ammonium compounds of Formula II, and about 2 to about 25 wt % at least one C.sub.4-8 organic tricarboxylic acid, or a salt thereof.

6. The laundry composition of claim 1 comprising: i. about 1.44 wt % of at least one dialkyldimethyl ammonium chloride (DDAC), where each alkyl group is independently selected from straight chain C.sub.8-C.sub.10 alkyl; ii. about 0.96 wt % of one or more alkyl dimethyl benzalkonium chlorides: ##STR00013## and iii. about 6.25 wt % citric acid.

7. The laundry composition of claim 1 comprising: i. about 1.44 wt % of at least one dialkyldimethyl ammonium chloride (DDAC), where each alkyl group is independently selected from straight chain C.sub.8-C.sub.10 alkyl; ii. about 0.96 wt % of one or more alkyl dimethyl benzalkonium chlorides: ##STR00014## and iii. about 5 wt % sodium citrate.

8. The laundry composition according to claim 1, wherein the composition does not comprise any further quaternary ammonium compounds.

9. The laundry composition according to claim 1, wherein the composition does not contain a bleach agent.

10. The laundry composition according to claim 1 wherein the at least one C.sub.4-8 organic tricarboxylic acid or the salt thereof is the C.sub.4-8 organic tricarboxylic acid and the pH of the solution is less than 7.

11. The laundry composition of claim 1, consisting essentially of: i. about 1.44 wt % of at least one dialkyldimethyl ammonium chloride (DDAC), where each alkyl group is independently selected from straight chain C.sub.8-C.sub.10 alkyl; ii. about 0.96 wt % of one or more alkyl dimethyl benzalkonium chlorides (BKC): ##STR00015## iii. about 2.5 wt % to about 15 wt % citric acid; iv. sodium hydroxide, and v. water.

12. The laundry composition of claim 1, consisting essentially of: i. about 1.44 wt % of at least one dialkyldimethyl ammonium chloride (DDAC), where each alkyl group is independently selected from straight chain C.sub.8-C.sub.10 alkyl; ii. about 0.96 wt % of one or more alkyl dimethyl benzalkonium chlorides (BKC): ##STR00016## iii. about 1 wt % to about 10 wt % a citric acid salt, and iv. water.

13. (canceled)

14. A method of sanitizing laundry during a laundry washing process comprising adding from about 30 to about 180 ml of the laundry composition of claim 1 to the fabric softener compartment of an automatic washing machine and using the automatic washing machine to perform a laundry washing process.

15. (canceled)

16. The laundry composition of claim 1, wherein R.sub.1, R.sub.2, R.sub.3, and R.sub.4 of Formula I are straight chained.

17. The laundry composition of claim 1, wherein X of Formula I is a chloride, bromide, iodide, or a methosulfate anion.

18. The laundry composition of claim 1, wherein R.sub.1, R.sub.2, R.sub.3, and R.sub.4 of Formula II are straight chained.

19. The laundry composition of claim 1, wherein X of Formula II is a chloride, bromide, iodide, or a methosulfate anion.

20. The laundry composition of claim 1, wherein the at least one C.sub.4-8 organic tricarboxylic acid or the salt thereof is the salt and the pH of the solution is from about 7 to about 10.

21. The laundry composition of claim 1, wherein the at least one C.sub.4-8 organic tricarboxylic acid or the salt thereof is the salt and the pH of the solution is greater than 7.

22. The laundry composition of claim 12, wherein the laundry composition consists essentially of about 5 wt % sodium citrate.

Description

EXAMPLES

[0097] The following examples illustrate exemplary formulations as well as preferred embodiments of the invention. It is to be understood that these examples are provided by way of illustration only and that further useful formulations falling within the scope of the present invention and the claims may be readily produced by one skilled in the art without deviating from the scope and spirit of the invention.

Test Method

[0098] The compositions in the tables below were evaluated for their antimicrobial efficacy against Staphylococcus aureus (ATCC 6538), Escherichia coli (ATCC 10536), Pseudomonas aeruginosa (ATCC 15442) and Enterococcus hirae (ATCC 10541).

[0099] The test method used to evaluate the antimicrobial effectiveness of the Examples was an antimicrobial suspension test based on British Standard reference No: EN 1276:2009 method entitled Chemical Disinfectants and AntisepticsQuantitative Suspension Test for the Evaluation of bactericidal activity of chemical disinfectants and antiseptics used in food, industrial, domestic and institutional areasTest method and requirements (Phase 2, step 1). A greater than 5-log reduction of all organisms (Pseudomonas aeruginosa, Staphylococcus aureus, Enterococcus hirae, Escherichia coli) for a contact time of 1 to 60 minutes (determined by product specification) at a testing temperature ranging from 4? C. to 60? C.+1.0? C. (determined by product specification) is required to pass the EN1276. Additional and optional contact times, temperatures, and test organisms can be used.

[0100] The test protocol tests the efficacy of the compositions of the present invention and the comparative examples against gram-negative and gram-positive bacteria. The test organisms used were Staphylococcus aureus (ATCC 6538), Escherichia coli (ATCC 10536), Pseudomonas aeruginosa (ATCC 15442) and Enterococcus hirae (ATCC 10541).

[0101] The bacterial strains were cultured on tryptic soy agar (TSA) slant from frozen stock and incubated for 18-24 hours. Following incubation, 2.sup.nd and 3.sup.rd generation transfers were prepared and used to prepare test suspensions as described in the BS EN 1276:2009 test method. The working culture must be either a second or third generation subculture on TSA slants from a cryogenic stock. The cell suspensions were adjusted to produce approximately 1.5-5.0?10.sup.8 CFU mL.sup.?1. Subcultures were prepared on TSA slants and incubated at 36?1? C. for 18-24 hours. The growth medium and temperature used were TSA and 36?1? C. Test solutions and test cultures are equilibrated to a test temperature of 20?1? C. in a water bath.

[0102] The tests were performed using clean experimental conditions, i.e. 0.3 g/l Bovine Albumin (BA) in-test concentration, rather than dirty experimental conditions, i.e. 3 g/l BA in-test concentration. For laundry sanitizers, the desired experimental conditions are clean conditions because the laundry sanitizer is used after a laundry detergent in a laundry washing process, i.e. on clean laundry.

[0103] Experimentally, a 1:1 dilution of the test culture and test conditions was performed and allowed to react for 2 minutes. 2.0 mL of the test culture was exposed to 8.0 mL of the test product for a 16-minute contact time and then a 1.0 mL aliquot was neutralized in a verified neutralizer. After a 5-minute neutralization time, the neutralized sample was serially diluted, plated on TSA and incubated at 36?1? C. for 48 hours. The average Log.sub.10 CFU/mL for the test suspension was calculated and used to compute the log reduction post-treatment. At least a 5-log reduction of all organisms tested for a 16-minute contact time was chosen to indicate that the tested formulation has the desired level of antimicrobial properties against tested organisms. Log reduction greater than 4 means >99.99% reduction in the number of cells; log reduction greater than 5 means >99.999% reduction in the number of cells and denotes complete kill.

[0104] The microbiocidal effect (ME) due to the action of the product over the test contact time at the temperature at which the test was performed is expressed by the formula below:

ME=Log Nc?Log Nd

[0105] where Nc=Number of cfu/ml of the test suspension count and Nd=Number of cfu/ml of the sample count after treatment.

Samples

[0106] DDAC and BKC are typically provided as solutions containing DDAC or BKC and solvents, which are typically selected from water, ethanol, isopropyl alcohol, ethylene glycol and mixtures thereof. In the following examples the DDAC used was Bardac? 2080, a twin chain dimethyl ammonium chloride composition available from Lonza (CAS No. 68424-95-3), which typically comprises 80% actives (Octyl decyl dimethyl ammonium chloride ?40%, Dioctyl dimethyl ammonium chloride ?16% and Didecyl dimethyl ammonium chloride ?24%), 10% water and 10% ethanol. In the following examples the BKC is BTC 1218-80, (80% BKC) available from Stepan (CAS No. 68424-95-3).

Sample Preparation

[0107] The following formulations were made by adding the raw materials step wise, waiting until the mixture was homogenous after each material was added before adding the next raw material. The raw materials were added in the following order. [0108] 1. Deionized water [0109] 2. BKC (BTC 1218-80) [0110] 3. DDAC (Bardac? 2080) [0111] 4. Organic acid(s) [0112] 5. Di-sodium EDTA [0113] 6. Sodium hydroxide (30%) [0114] 7. Deionised water

[0115] The sodium hydroxide was added in an amount to adjust the formulation to about pH 3. The final step of deionised water was added in an amount sufficient to achieve the desired amount of active, e.g. 1.8 wt % DDAC and 1.2 wt % BKC.

TABLE-US-00001 Sample 1 2 3 4 5 6 Citric acid (50% 12 8.3 12.5 12.5 sol) Lactic acid (50% 12.5 4.2 12.5 sol) Succinic Acid Di-Sodium EDTA BKC (80% active) 3 3 3 1.2 3 3 DDAC (80% active) 1.8 Sodium Hydroxide 3.2 1.716 2.484 2.796 2.656 1.74 Sol. (30%) pH 3.99 3 3.01 3 3.03 3 S. aureus >5.18 5.23 >5.23 >5.23 >5.23 5.26 E. coli >5.37 5.28 4.02 5.28 4.3 4.12 P. aeruginosa 3.76 4.3 4.23 5.39 4.72 3.22 E. hirae >5.32 >5.39 >5.45 5.45 >5.45 >5.49

TABLE-US-00002 Sample 7 8 9 10 11 Citric acid (50% sol) 6.5 12.5 12.5 Lactic acid (50% sol) 8 12.5 Succinic Acid 4.5 Di-Sodium EDTA 0.5 0.5 BKC (80% active) 3 1.2 1.2 1.2 1.2 DDAC (80% active) 1.8 1.8 1.8 1.8 Sodium Hydroxide Sol. 1.688 1.98 2.0 2.0 1.73 (30%) pH 3.03 3 3.07 3.03 3.03 S. aureus 5.09 5.26 >5.28 >5.14 >5.27 E. coli 4.44 3.92 >5.37 >5.27 >5.31 P. aeruginosa 2.33 5.52 >5.32 >5.27 >5.29 E. hirae 5.46 >5.49 >5.29 >5.29 >5.30

Results

[0116] Samples 1-3 and 5-7 did not contain DDAC and did not provide a 5-log reduction in P. aeruginosa when tested.

[0117] Samples 2 and 6-8 did not contain citric acid and did not provide a 5-log reduction in all four bacteria, typically not against P. aeruginosa. Sample 8 achieved a 5-log reduction in three bacteria but did not achieve a 4-log reduction in E. coli.

[0118] All samples containing citric acid, BKC and DDAC achieved a 5-log reduction in all four bacteria, see samples 4 and 9-11. Surprisingly, halving the amount of citric acid still led to a greater than 5-log reduction against all four bacteria, see sample 9 and sample 11.

[0119] Tests on samples containing sodium citrate also provided a 5-log reduction in all four bacteria.

[0120] The results above demonstrate that the compositions of the present invention show excellent antimicrobial activity against all four bacteria tested.

Example 2

[0121] In the following experiments, all samples were prepared using the method above.

[0122] The samples for Experiment 1 used a small amount of non-ionic surfactant to improve stability, so a small amount of non-ionic surfactant was added to all samples in these Experiments. The effect of this small amount of non-ionic surfactant on the germ kill efficacy was considered to be negligible. Samples for Experiment 2 did not require any non-ionic surfactant.

[0123] The Samples were tested using the same method above. However, the Samples were tested against Pseudomonas aeruginosa (PSA) only. As shown above, PSA is the most resilient organism, and the Samples were considered highly likely to provide a 5-log reduction against S. aureus, E. coli and E. hirae, particularly if a 5-log reduction was achieved against PSA.

Experiment 1

[0124]

TABLE-US-00003 A B C D E F BKC 0.8 0.96 0.84 0.96 0.84 0.84 DDAC 0.8 1.44 0.84 1.44 0.84 0.84 ADEBAC 0.8 0.84 0.84 0.84 Malonic Acid 0.75 Citric Acid 0.75 6.25 3 Lactic Acid 3 3 6.25 Total Quat 2.4 2.4 2.52 2.4 2.52 2.52 Total Organic Acid 1.5 6.25 3 3 6.25 3 PSA Results <4.10 >5.47 4.23 4.38 >5.47 >5.47

[0125] The success criteria in testing were a log reduction above 5 in PSA and so the result for Sample A was given as below 4.1 log reduction, i.e. below the quantification of the test. Sample B, the sample according to the invention, therefore showed an improved antimicrobial activity versus Sample A, which had a Quat: Organic Acid (Q:OA) ratio of 37.5:23.4.

[0126] Samples C and D (lactic acid) had a Q:OA ratio of 1:1.19 and 1:1.25, respectively and did not achieve a 5-log reduction in PSA. Sample F, which contained citric acid, showed improved antimicrobial activity over Sample C (equivalent amount of lactic acid).

Experiment 2

[0127] In this experiment, the samples all contained the same quat blend, i.e. 0.96 wt % BKC and 1.44 wt % DDAC (from 1.2 wt % of an 80% active BKC solution and 1.8 wt % of an 80% active DDAC solution) and the amounts of citric acid and malonic acid were varied. As above, the success criteria in testing were a greater-than 5-log reduction in PSA.

TABLE-US-00004 A B C D I E F G H J Citric Acid 2.5 2 1.5 1 0.5 1.5 1 0.75 0.5 0.25 Malonic Acid 1.5 1 0.75 0.5 0.25 PSA Results >5.31 >5.31 >5.31 >5.31 4.6 >5.31 >5.31 >5.31 4.96 4.24

[0128] Samples D and H both contained 1% organic acid. Sample D containing citric acid without malonic acid showed improved antimicrobial activity over Sample H containing citric acid and malonic acid.

[0129] Sample G demonstrates that the quat combination of the present invention provides improved antimicrobial activity versus the 0.8 wt % BKC, 0.8 wt % DDAC and 0.8 wt % ADEBAC used in Experiment 1, Sample A above.