US 3836669 A
Description (OCR text may contain errors)
United States Patent 3,836,669 METHOD OF KILLING BACTERIA USING DIDECYL DIMETHYL AMMONIUM CHLORIDE Zaven A. Dadekian, Sutfern, N.Y., assignor to Baird Chemical Industries, llrlc., New York, NY.
No Drawing. Continuation of application Ser. No.
703,598, Feb. 7, 1968, which is a continuation-inpart of application Ser. No. 617,805, Feb. 23, 1967, both now abandoned. This application Aug. 25, 1971, Ser. No. 174,933
Int. Cl. A01n 9/20 U.S. Cl. 424-329 3 Claims ABSTRACT OF THE DISCLOSURE A method of killing bacteria in the presence of hard water and blood serum by contact with didecyl dimethyl ammonium chloride.
This is a continuation of U.S. application Ser. No. 703,598, filed Feb. 7, 1968, now abandoned, which is in turn a continuation-in-part of U.S. application Ser. No. 617,805, filed Feb. 23, 1967, now abandoned.
This invention relates to new germicidal compositions and their use as germicides in several specialty applications.
The germicidal compositions of the invention contain a quaternary ammonium compound having the formula:
wherein R and R are alkyl having from eight to twelve carbon atoms, and R and R together having an average of nine to eleven carbon atoms; R is a lower alkyl group containing one to four carbon atoms, a lower alkanol group containing two or three carbon atoms, an aralkyl group, or a chloro or alkyl substituted aralkyl group; R is a lower alkyl group containing one to four carbon atoms or a lower alkanol group containing two or three carbon atoms; and X- a chloride, an ethosulfate, or a methosulfate. R and R are the same or different and can be branched or straight chain alkyl, preferably, normal. R is preferably methyl, ethyl hydroxyethyl, benzyl, chlorobenzyl, dichlorobenzyl, or an alkyl benzyl group having one to three alkyl substituents with a total of no more than six carbon atoms in all of the alkyl snbstituents. R is preferably methyl or ethyl.
Examples of these quaternary ammonium compounds are didecyl dimethyl ammonium chloride, didecyl dimethyl ammonium methosulfate, didecyl dimethyl ammonium ethosulfate, didecyl methyl propyl ammonium chloride, didecyl methyl butyl ammonium chloride, didecyl methyl benzyl ammonium chloride, didecyl ethyl benzyl ammonium methosulfate, didecyl methyl ethyl ammonium chloride, didecyl diethyl ammonium chloride, didecyl methyl 4-chlorobenzy1 ammonium chloride, didecyl methyl 3,4- dichlorobenzyl ammonium chloride, decyl octyl dimethyl ammonium chloride, decyl octyl benzyl methyl ammonium chloride, decyl dodecyl dimethyl ammonium chloride, decyl dodecyl ethyl methyl ammonium chloride, dinonyl methyl 2,4-dimethylbenzyl ammonium chloride, diundecyl dimethyl ammonium chloride dinonyl hydroxyethyl methyl chloride, didecyl hydroxypropyl methyl chloride and diundecyl dihydroxyethyl chloride. Blends of compounds containing dioctyl, didecyl and decyl octyl compounds or didecyl, didodecyl and decyl dodecyl compounds are also within the scope of the invention. Many of the compositions of the invention are novel compositions of matter. These include the dodecyl alkyl benzyl and substituted benzyl compounds and the dioctyl-didecyl and the didecyl-didodecyl blends.
Germicidal compositions containing the quaternary ammonium compounds of this invention exhibit unique characteristics as compared with apparently similar compositions containing other closely related quaternary compounds. Specifically, the compositions have exceptional germicidal activity and unusually high tolerance to hard Water and organic soil. Moreover, they have sufficiently high tolerance to anionic surfactants to make them useful for sanitizing or disinfecting hard surfaces in the presence of anionic surfactant. In the light of all these unique properties, the compositions of the invention are particularly useful for hard surface disinfectant and sanitizer applications. Additionally, those compounds having an average number of carbon atoms in the long-chain alkyl groups of nine are particularly useful in laundry applications.
The quaternary ammonium compounds used in the invention may be prepared by any known process. See, for example, A. W. Ralston et al., J. Org. Chem 13, p. 186 (1948).
For hard surface disinfectant and sanitizing applications, the quaternary ammonium compounds are generally applied in a use dilution containing from 50 to 2500 p.p.m. quaternary, depending on the particular application. Preferably, the quaternary is prepared as a concentrate composed of Water and a lower alcohol, such as, methanol, ethanol or isopropanol, as the solvent system. From 0.5 to 4 parts of the quaternary are dissolved in one part by weight the total solvent.
A particularly unique property of the quaternary compounds of the invention is the retention of high germicidal activity in the presence of significant quantities of soap and synthetic anionic detergents.
This anionic surfactant tolerance makes the compositions of the invention useful for sanitizing and disinfecting surfaces which have previously been cleaned with, and contain residual amounts of, anionic detergents.
The anionic surfactants used for cleaning hard surfaces have the formula RCOOM, RSO M or ROSO M, where M represents an alkali metal, ammonium or substituted (amine) group and R represents an organic radical having more than 8 carbon atoms. Examples are soaps, fatty acid sarcosinates, alkyl sulfonates, alkyl sulfates, sulfated ethers of long chain aliphatic groups, sulfonated alkyl esters of long chain fatty acids, sulfonated glycol esters of long chain fatty acids, sulfonated alkyl substituted amides of long chain fatty acids, alkylated aryl sulfonates, alkyl sulfosuccinates, and organo phosphate ester surfactants. The definition of anionic surfactants also includes amphoteric surface active agents formulated at a pH above their isoelectric point. These ampholytic surfactants include N-fatty amino propionates, N-fatty iminodipropionates, cycloimidates and N-fatty aryl-N-alkaline or amine carboxymethyl-N-(Z-hydroxyethyl ethylene diamine.
Where the quaternary compounds of the invention are used as sanitizers, their use dilution content is from 50 to 500 ppm, preferably from 150 to 300 ppm. If desired, they may be formulated With non-ionic detergents and/ or detergent builders. A solvent coupler is added to obtain the requisite stability. Based on one part by weight of the quaternary compound, from 0 to 10 parts, preferably from 0.25 to 1 part, of a non-ionic surfactant may be used. The detergent builders are added in amounts ranging from 0.5 to 10 parts by weight, preferably from 1.0 to 5 parts. Typical formulations are:
Acid Detergent Sanitizer Percent Decyl octyl dimethyl ammonium chloride 8 Nonylphenol poly(ethyleneoxy)ethanol 4 Phosphonic acid -a 30 Water 58 Where the quaternary compounds of the invention are used for disinfecting, their concentration in aqueous use dilution ranges from 200 to 3000 p.p.m. preferably from 350 to 650 ppm. Non-ionic surfactants and/or detergent builders may also be used in the same quantities as described for the sanitizer formulations. An example of such formulation is:
Detergent Disinfectant Percent Octyl decyl dimethyl ammonium chloride 5 Nonylphenol poly(ethyleneoxy)ethanol 5 Sodium carbonate 1 Sodium tripolyphosphate 6 Tetrasodium ethylene diamine tetraacetate 1 Water 82 The non-ionic surfactants which may be formulated with the quaternary compounds of the invention include:
(1) Monoethers of polyglycols with long-chain fatty alcohols, such as reaction products of ethylene oxide or polyethylene glycol with a long-chain fatty alcohol (e.g. reaction product of ethylene oxide and myristyl alcohol, viz:
where n is 5 to 20).
(2) Monoesters of plyglycols with long-chain fatty acids, such as reaction products of ethylene oxide or polyethylene glycol with a long-chain fatty acid (e.g. reaction product of ethylene oxide or polyethylene glycol with lauric acid, viz:
where n is 5 to 20).
(3) Monoethers of polyglycols with alkylated phenols, such as reaction products of ethylene oxide or polyethylene glycol with an alkyl phenol (e.g. reaction product of ethylene oxide and nonyl phenol), viz:
Colin CzHOnOH where n is to 20.
(4) Polyoxyethylene sorbitan fatty and/or resin acid esters, e.g. polyoxyethylene sorbitan monolaurate. The latter is the reaction product of sorbitan monolaurate and either ethylene oxide or polyethylene glycol.
(5) N,N-polyethoxylates and polypropoxylates of long chain aliphatic amines. For example, the reaction product of either ethylene oxide or polyethylene glycol with coco amine yields:
(CHzOH2O)zH R- N/ (OHzCHzOMH where R is coco and x+y= moles of ethylene oxide. (6) N,N-polyethoxylates and/or polypropoxylates of long chain aliphatic acid amides. For example, the reaction product of either ethylene oxide or polyethylene glycol and hydrogenated tallow amide yields:
where RC is hydrogenated tallowyl x+y=50 moles of ethylene oxide.
The detergent builders which may be used include:
(1) Water soluble inorganic alkaline builder salts alone or in admixture; e.g., carbonates, borates, phosphates, polyphosphates, bicarbonates and silicates. Specific examples of such salts are sodium tripolyphosphate, sodium carbonate, sodium tetraborate, sodium acid pyrophosphate, sodium bicarbonate, potassium tripolyphosphate, tetrapotassium pyrophosphate, sodium hexametaphosphate, sodium sesquicarbonate, trisodium phosphate, and potassium bicarbonate. Such inorganic builder salts enhance the detergency of the composition.
(2) Water soluble or anic sequestrant builder salts used alone or in admixture, such as alkali metal, ammonium or substituted ammonium amino polycarboxylates, e.g., sodium and potassium ethylenediaminetetraacetate, sodium and potassium N-(2-hydroxyethyl) ethylenediaminetriacetates, sodium and potassium nitrilotriacetates and sodium potassium, and triethanolammonium N-(2- hydroxyethyl)iminodiacetates. Other organic sequestrant builder salts which can be used are: N-hydroxyethyliminodiacetates, dihydroxyethyl glycinates, diethylenetriaminepentaacetates; 1,2 cyclohexanediamine tetraacetates. Mixed salts of these polycarboxylates are also suitable. Gluconic acid, phytic acid and their alkali and amine salts are also suitable as organic sequestrant builders.
In the case of laundry product applications, the compounds of the invention may be added during the washing or rinse cycle. When used during the wash cycle, they are formulated with a non-ionic detergent so that the applied dose of the compounds of the invention is 50-3000 p.p.m., preferably -400 p.p.m., based on the dry weight of clothes load. A typical antimicrobial laundry detergent formulation is the following:
Antimicrobial Laundry Detergent Percent Octyl decyl dimethyl ammonium chloride 0.8 Linear sec. alcohol ethylene oxide adduct 10.0 Sodium tripolyphosphate 40.0 Sodium metasilicate pentahydrate 12.5 Sodium carboxymethyl cellulose 1.5 Optical brightener 0.4
Anhydrous sodium sulfate 34.8
Tergitol 15-S-9, a trademark of Union Carbide Corporation for polyethylene glycol ether of a linear secondary alcohol containing an average of nine moles of ethylene oxide per mole of alcohol.
b Car-hose D, a trademark of Wyandotte Chemical Corporation for sodium carboxymethylcellulose. 65 percent active.
Hiltamine CWD, a trademark of Hilton-Davis Chemical Company for a compound having the formula:
In commercial laundries, the germicides may be added with the laundry sour. Sours, added to neutralize residual alkali 0r hypochlorite bleach, are commonly ammonium, zinc or sodium silicofluoride. The quaternary compounds of this invention are used in the range of 0.1-10
'5 parts, preferably 0.2-0.5 part, to one part by weight of fluoride sour. A typical example is:
Germicidal Laundry Sour Percent Didecyl benzyl methyl ammonium chloride 33 Ammonium silicofluoride 67 the fabric softener for each part of the quaternary ammonium compound. Examples of fabric softeners are: di(hydrogenated tallow)dimethyl ammonium chloride and 1 methyl-1-alkaneamidoethyl-2-alkylimidazolinium methylsulfate, e.g. l-methyl-1-stearylamidoethyl-Z-stearylimidazolinium methylsulfate. Examples of optical brighteners are: bis-thiazinyl derivatives of 4,4'-diaminostilbene- 2,2'-disulfonic acid and benzimidazolyl derivatives. A typical formulation is:
Germicidal Fabric Softener p I Percent l-methyl 1 stearylamidoethyl-Z-stearyl-imidazolinium methylsulfate 5.1 Isopropyl alcohol 1.6 Octyl decyl dimethyl ammonium chloride 1.5 Optical brightener (20% active) 1.5 Water 91.3
Hiltamlne Arctic White CC, a trademark of Hilton-Davis Chemical Company for a compound having the formula:
N (onlcmomiN-f Tun .While all of the compounds of the invention are useful for laundry products applications, it has been found that surprisingly useful results are obtained with a blend of the'didecyl dimethyl ammonium chloride and the dioctyl dimethyl ammonium chloride. The blend may contain from :1 to 1:10 by weight of each quat, preferably, from 3:1 to 1:3. The presence of the decyl octyl dimethyl ammonium compound is advantageous.
A particularly outstanding blend for laundry applications may be prepared as follows:
EXAMPLE A Using a one gallon autoclave 6 moles of octyl chloride and 6 moles of decyl chloride are reacted with 6 moles of monomethylamine in the presence of grams of potassium iodide and 1056 grams of 50% aqueous caustic (13.2 moles NaOH). The reaction continues for 6 hours at 165 CfAfte'r cooling to 120 C., the two phases are separated and the upper phase vacuum stripped and a product having a molecular weight of 294 is obtained.
Of this product, 2.55 moles are loaded into a one gallon autoclave with 230 grams of isopropyl alcohol. A vacuum is drawn and 2.50 moles of methyl chloride is loaded. The batch is heated at 80 C. for 2 hours. The quaternary ammonium salt obtained has a statistical distribution of products which is approximately dioctyl, 25% didecyl and 50% decyl octyl dimethyl ammonium chloride. The superiority of this material for laundry products applications is shown subsequently.
Benzyl didecyl methyl ammonium chloride is a water soluble, crystalline quaternary melting at 85 -8 C. These physical properties, combined with outstanding disinfectant activity, make it particularly applicable for easy dry blend production of solid disinfectant products, e.g., powdered disinfectant cleaners, sanitizer tablets and powdered antimicrobial laundry detergents. The following blends are useful for the stated application:
Powdered Disinfectant Cleaner Percent Benzyl didecyl methyl ammonium chloride 5 Linear primary alcohol ethylene oxide adduct 5 Sodium tripolyphosphate 55 Sodium carbonate 35 Plin-afax A-38 (flaked) a trademark of Wyandotte Chemical Corporation for the polyethylene glycol ether of a linear primary alcohol.
Sanitizing Tablet Percent Benzyl didecyl methyl ammonium. chloride 50.0 Sodium bicarbonate 12.5 Citric acid 6.3 Dextrose 15.0 Sodium chloride 16.2
Antibacterial Laundry Detergent Percent Benzyl didecyl methyl ammonium chloride 1.0 Linear primary alcohol ethylene oxide adduct a 10.0 Sodium tripolyphosphate 40.0 Sodium carbonate 34.7 Sodium metasilicate pentahydrate 12.5 Sodium carboxymethyl cellulose (65% active) 1.5 Optical brightener 0.3
"Plurafac A-3S (flaked) Wyandotte Chemicals Corp. Carbose D Wyandotte Chemicals Corp. c Hiltamine CWD Hilton-Davis Chemical Co. The preparation of the aforesaid compound is shown in the following example:
EXAMPLE B A mixture of 31.1 g. of didecylamine, 12.6 g. of benzyl I chloride, 400 ml. of acetonitrile and 200 m1. of acetone was refluxed 16 hours on a steam bath. The mixture of solvents was removed by distillation in vacuo and the remaining oil takes up in about 100 ml. of isopropanol. The solvent was again removed by distillation in vacuo. The residual yellow oil was dissolved in absolute ether and diluted with n-pentane until crystallization commenced. Crystallization proceeded slowly and additional n-pentane was added from time to time. After standing overnight, white crystalline product was collected on a suction funnel, washed with additional n-pentane and dried free of solvent; yield, 30.5 g. of white crystalline product, which was didecyl methyl benzyl ammonium chloride, melting at 88 C.
Calcd. for C H NO: N, 31.7%. Found: N, 31.4%.
Didecyl methyl benzyl ammonium chloride is soluble in Water to the extent of 4.7%.
In order to show the efficacy of the compounds of the invention, a comparison with other quaternary ammonium compounds is set forth in the following examples. For brevity these known compounds shall be referred to in the examples as follows:
Quaternary A-a blend of 50% n-alkyl (60% C 30% C 5% C 5% C benzyl dimethyl ammonium chloride and 50% n-alkyl (50% C 30% C 17% C 3% C dimethyl ethylbenzyl ammonium chloride.
Quaternary Bn-alky1 (50% C 40% C12, 10%
C benzyl dimethyl ammonium chloride.
In the case of the compounds of the invention used in the example, where the long-chain alkyl groups differ,
7 e.g., decyl octyl dimethyl ammonium chloride and decyl dodecyl dimethyl ammonium chloride, the compositions contain a statistical distribution of materials such as described in Example A. Such compositions have longchain alkyl groups between eight and twelve and an average number of carbon atoms of nine and eleven, respectively.
EXAMPLE I In order to illustrate the outstanding biological activity of the compounds of the invention, Broth Dilution Tests were performed. See Cutler, et al. Soap and Chemical Specialties, volume XLIII, no. 4; page 74 (April 1967). In the Broth Dilution Tests (18 hr. immersion), the minimum inhibitory concentration was determined. In Table 1, columns 1 and 2 show the performance of two quaternaries within the scope of the invention. Column 3 illustrates the results obtained with another quaternary and column 4 a. quaternary ammonium bromide.
TABLE 1.B ROTH DILUTION TEST Minimum inhibitory concentration (p.p.m.) of
Bacteria 1 2 3 4 Staphylococcus aareua- 0. 5 0. 5 0. 5 l Escherichia coli 5 10 Pseadomonas aerugihosa 50 50 150 50 Norrn.1=didecyl dimethyl ammonium chloride; 2=decyl octyl dimethyl ammonium chloride; 3=quaternary A (above identified); 4=decy1 octyl ethyl methyl ammonium bromide.
Fungi l 2 3 4 Aspcrgill'us higcr 5 10 15 20 Trichlophyton mentagrophytcs 5 10 5 20 Candida albicahs 1 5 5 20 NOTE.1=dideeyl dimethyl ammonium chloride; 2=decyl octyl dimethyl ammonium chloride; 3=decyl octyl benzyl methyl ammomum chloride 4=quaternary A (above identified).
Table 3 describes the superior fungistatic activity of the compounds of the invention, when compared with Quaternary A.
EXAMPLE IV This example shows the unusually high Phenol Coefiicient obtained by using the compositions of the invention. Phenol Coefficients are determined according to'the procedure described in Official Methods of Analysis of the Association of Oflicial Agricultural Chemists, 10th Ed. Washington, DC. (1965), hereinafter AOAC, pages 80-82.
TABLE 4 Phenol coefficient Bacteria 1 2 3 4 5 6' 7 thb'llhlilfilfiKit::13:3:311:13: 823 "332 333 i333 til it NorE.1=didecyl dimethyl ammonium chloride; 2=didecyl benzyl methyl ammonium chloride; 3=decy1 octyl dimethyl ammonium chloride; 4=decyl octyl benzyl methyl ammonium chloride; 5=decyl dodecyl dimethyl ammonium. chloride; 6=dioctyl dimethyl ammonium chloride; 7 =didodecyl dimethyl ammonium chloride.
The above quaternary compounds all show high bacteriostatic activity towards Staphylococcus aureus. Gram negative bacteria are known to be more resilient to quats than Gram positive organisms. Unexpectedly, the dialkyl quats of the invention show significantly superior Gram negative activity.
EXAMPLE II To illustrate the speed of kill of bacteria, the Germicidal Efiiciency Tests were preformed using a preferred compound of the invention and a commercial compound. This test, which is carried out with distilled water, is a modification of the Germicidal and Detergent Sanitizers Test (see Oflicial Methods of Analysis of the Association of Official Agricultural Chemists; 10th edition; paragraphs 5.023-5.026, 5029-5032; pp. s7-9 (1965). Table 2 describes the concentration required to effect 99.999% reduction in bacteria count in seconds:
TABLE 2 Germicidal etficiency test, p.p.m.
Bacteria 1 2 S aareus. 10 25 Escherichia coli 13 2O Pscudomonas aeruginoaa 25 33 No'm.1=dldecyl dimethyl ammonium chloride; 2=quaternary 13 (above identified).
Table 2 showss that the compounds of the invention shows overall faster speed of kill than the benzalkonium chloride compound.
Table 4 shows that either a slight increase or reduction in the average number of carbon atoms in the dialkyl moiety of the compounds causes a sharp depression in antibacterial activity as measured by the standard Phenol Coefiicient Test. The attached Figure illustrates graphically the criticality of the average number of carbon atoms in the two long chain alkyl groups on the 'bactericidal activity of the quaternary compounds.
EXAMPLE V The didecyl compounds retain higher bactericidal activity toward Staphylococcus aureus in the presence of organic soil than the commercially avaliable ben2alkonium chlorides. This is shown in Table 5 by carrying out the Phenol Coefficient Test against Staphylococcus aureus in the presence of blood serum loads.
TABLE 5 Phenol coctficient vs Percent retention of Staphylococcus aereas activity Percent blood serum 1 2 3 1 2 3 (above identified); 3=quaternary B (above identified).
No'rE.1=didecyl dimethyl ammonium chloride; 2=quaternary A EXAMPLE VI Another hard surface disinfectant test, viz., the AOAC Use Dilution Method, pp. 82-84 of AOAC, surpa, demonstrates the high retention of activity of the decyl octyl dimethyl ammonium chloridein. the presence. of an anionic surfactant load, viz., sodium stearate. .Thiswas demonstrated using Staphylococcus aureus as the test organism. The usual level of quaternary for disinfectant action, i.e., 400 p.p.m., was also used. The results in Table 6 are reported as the number of positions per ten carriers tested, where positives indicate growth of bacteria and the lack of disinfectant action.
TABLE 6 Number of positives per 10 ring carriers Anionic surfactant (p.p.m.) (soap) MOO r- E ve N Nora. 1=decyl octyl dimethyl ammonium chloride; 2=quaternary (above identified); 8=quaternary B (above identified).
The above results confirm the high retention of bacterial activity of the compositions of the invention in the presence of an anionic surfactant. For example, this latter quality makes the compounds of the invention particularly useful for use in disinfectant formulat ons applied to surfaces previously cleaned with aniomc detergents.
EXAMPLE VII In order to demonstrate the outstanding hard water tolerance of the compounds of the invention, with respect to Escherichia coli, the Germicidal & Detergent Sanitizers Test, described in AOAC, supra, pgs. 87 and 89, was performed. Table 7 illustrates the results obtained.
TABLE 7 Quaternary Ammonium Hard Water Tolerance Chloride (p.p.m. CaCO Didecyl dimethyl 1500 Didecyl benzyl methyl 1000 Decyl dodecyl dimethyl 1000 Dioctyl dimethyl -100 Didodecyl dimethyl 700 Quaternary A (above identified) 850 Quaternary B (above identified) 650 The above table shows that the compounds which have an average of 10 to 11 carbon atoms in the alkyl chains have exceptionally high hard water tolerance. While the didecyl dimethyl ammonium chloride is most outstanding, the other compounds of the invention which are illustrated are also markedly better than Quaternaries A and B. The inferior results obtained with the dioctyl and didodecyl dimethyl ammonium compounds show the importance of the number of carbon atoms in the long chain alkyl group with regard to hard water tolerance performance.
EXAMPLE VIII The antibacterial activity of the compounds of the invention was evaluated for their application in non-ionic laundry detergents. Cotton test swatches (80 x 80 mesh, Test Fabrics Inc.) are treated with an aqueous solution containing a germicidal quat and 0.3% laundry detergent in a Launder-ometer (Type LHD-EF, Atlas Electric Devices Co.). The composition of the laundry detergent is:
Antibacterial Laundry Detergent Percent Linear nonylphenol poly(ethyleneoxy)ethanol 10.0
Decyl octyl dimethyl ammonium chloride 1.0 Sodium tripolyphosphate 40.0 Sodium metasilicate pentahydrate 12.5
each part of fabric (based on the dry Weight thereof) for 4 minutes at 100 F. The rinse water is then decanted. The wet cloth is placed in a clothes wringer adjusted to a first moisture pick-up equal to the dry weight of the fabric. The moist fabric is dried and then evaluated for residual antibacterial activity by the method of Haskins, et al. Factors Influencing the Detection of Antimicrobial Activity of Treated Fabric; Proceedings of the 53rd Mid- Year Meeting of the Chemical Specialties Manufacturers Association (May 1967).
Table 8 shows the superior antibacterial activity of the compounds of the invention containing an average of nine carbon atoms in the two long chain alkyl groups. The bacteristatic levels found in. Table 8 describe the minimum quantity of quaternary compound (based on the dry weight of fabric) added to the detergent during the wash cycle required to effect 100% inhibition of bacteria count on the treated cloth.
Broad spectrum antibacterial claims for laundry detergent products require imparting effective residual activity to fabric against Gram negative (E. coli), as well as Gram positive (S. aureus) bacteria. The required dose for obtaining these claims is considerably less when using compounds of the invention.
EXAMPLE IX The antibacterial activity of the compounds of the invention was evaluated for their application in final rinse laundry products. Cotton test swatches x 80 mesh, Test Fabrics Inc.) are treated with an aqueous solution, containing a germicidal quat in a. Tergotometer (Model 7243, US. Testing Co.). The final rinse conditions are: solution to cloth ratio20:l; temperature of solution- F.; and time-4 minutes. After treatment, the rinse solution is decanted. The wet cloth is wrung in a clothes winger so that the moisture pick-up is 1:1 based on the dry weight of cloth. The moist cloth is dried and evaluated for residual antibacterial activity by the method of Haskins, et al. supra.
TABLE 9 Required level for 100% inhibition,
Compound S. aureus E. colt Decyl octyl dimethyl ammonium chloride. 200 Didecyl dimethyl ammonium chloride 150 400 Quaternary A (above identified) 150 400 Broad spectrum antibacterial claims for final rinse products require effective residual activity towards Gram negative (E. CD), as well as Gram positive (S. aureus) activity. Table 9 demonstrates the considerably lower dose .1 1 1 2 prises contacting the E. coli with from 50 to 3000 p.p.m. OTHER REFERENCES. of didecyl dimethyl ammonium chloride. H k t A d U 9 3. A method of killing S. aureus in the presence of blood e pp 1e 1cm w 6 .6 3
serum which comprises contacting the S. aureus with from K h t Ch Ab L 35 5 50 to 3000 p.p.m. of didecyl dimethyl ammonium chlo- 5 u n e a em s V0 3 97 (1941) Deciquam 222 Technical bulletin. 7 V ride. Resuggan, Quaternary Ammonium Compds. in 'Chem- References Cited ical sterilisation, 1951, pp. II, 12-120.
UNITED STATES PATENTS 3,223,645 12/1965 Kalberg 257-117 10 fi l j Puma f V, or
FOREIGN PATENTS RO SON, Assistant Examiner 795,814 5/ 1958 Great Britain. US. Cl. X.R.
6,802,352 8/1968 Netherlands. 252106, 107