Patent Application
20090004287
The invention relates to disinfectant compositions comprising hydrogen peroxide and quarternary ammonium compounds. It further relates to a method for killing or inhibiting the growth of microorganisms by applying a disinfectant composition according to the invention. Another object of the invention is a method for inhibiting the decomposition of aqueous solutions of hydrogen peroxide. Still another object of the invention is a method for inhibiting the corrosive action of hydrogen peroxide solutions on metals.
The use of quaternary ammonium compounds as biocides is well known (see e.g. Kirk-Othmer's Encyclopedia of Chemical Technology, 3rd Ed., Vol. 7, pp. 793-832, in particular pp. 815-818). Also well known is the use of hydrogen peroxide as an antiseptic (Kirk-Othmer, loc. cit., p. 807). Each of these compounds have their own weaknesses and strengths. For example, quaternary ammonium compounds are less effective in the presence of hard water and surfactants, while hydrogen peroxide is less affected by these factors. On the other hand, quaternary ammonium compounds are more stable in solution, and are biologically efficacious at lower concentrations than hydrogen peroxide. A problem with both halogenated quaternary ammonium compounds and hydrogen peroxide is that they are corrosive to metals.
Accordingly, the problem to be solved by the present invention was to provide disinfectant compositions comprising quaternary ammonium compounds and hydrogen peroxide which are chemically stable and non-corrosive to metals.
According to the invention, this problem has been solved by the disinfectant compositions of the invention.
It has been found that biocidal quaternary ammonium carbonates and bicarbonates, more specifically, benzylalkyl- or dialkyldimethylammonium salts containing either carbonate, bicarbonate, or a combination thereof, as the anion, used in combination with hydrogen peroxide make a highly effective disinfectant which is chemically stable and non-corrosive to metals.
Provided is a disinfectant composition comprising at least one biocidal quaternary ammonium compound selected from the group consisting of quaternary ammonium carbonates and quarternary ammonium bicarbonates; and hydrogen peroxide.
In a preferred embodiment, the quaternary ammonium carbonates and bicarbonates have the formulas
(R1R2R3R4N+)2CO32− (I)
and
R1R2R3R4N+HCO3− (II),
wherein R1 is benzyl or C8-20 alkyl;
R2 is selected from the group consisting of C8-20 alkyl and —[(CH2)2—O]n—R5, wherein n is an integer from 1 to 20 and R5 is selected from the group consisting of hydrogen, phenyl and alkyl-substituted phenyl; and R3 and R4 are independently C1-20 alkyl.
Here and hereinbelow the expression “C1-20 alkyl” is to be understood to comprise all linear or branched alkyl groups having 1 to 20 carbon atoms, including, but not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, tert-pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl and icosyl. Accordingly, the expression “C8-20 alkyl” is to be understood to comprise all linear or branched alkyl groups having 8 to 20 carbon atoms.
The expression “alkyl-substituted phenyl” is to understood to comprise any phenyl group bearing from one to five alkyl groups, in particular C1-20 and preferably C1-8 alkyl groups as substituents.
More preferably, R1 and R2 are C8-20 alkyl and R3 and R4 are methyl.
Still more preferably, R1 and R2 are C10 alkyl, most preferably n-decyl.
Preferably, the weight ratio of quaternary ammonium compound(s) to hydrogen peroxide is from 1:100 to 2:1, more preferably from 1:20 to 1:1, and even more preferably from 1:5 to 1:1.
Another object of the invention is a method for killing or inhibiting the growth of microorganisms, algae and/or fungi, said method comprising applying a disinfectant composition as described above to a substrate in or on which said microorganisms, algae and/or fungi are growing or may grow.
Still another object of the invention is a method for inhibiting the decomposition of aqueous solutions of hydrogen peroxide, said method comprising adding at least one quaternary ammonium compound selected from the group consisting of quaternary ammonium carbonates and quaternary ammonium bicarbonates to said aqueous solution of hydrogen peroxide.
Yet another object of the invention is a method for inhibiting the corrosive action of aqueous solutions of hydrogen peroxide on metal surfaces, said method comprising adding at least one quaternary ammonium compound selected from the group consisting of quaternary ammonium carbonates and quaternary ammonium bicarbonates to said aqueous solution of hydrogen peroxide.
Preferably, the quaternary ammonium carbonates and bicarbonates to be employed in the above methods for inhibiting the decomposition of aqueous solutions of hydrogen peroxide or their corrosive action on metal surfaces have the formulas
(R1R2R3R4N+)2CO32− (I)
and
R1R2R3R4N+HCO3− (II),
wherein R1 is benzyl or C8-20 alkyl;
R2 is selected from the group consisting of C1-20 alkyl and —[(CH2)2—O]n—R5, wherein n is an integer from 1 to 20 and R5 is selected from the group consisting of hydrogen, phenyl and alkyl-substituted phenyl;
and R3 and R4 are independently C1-20 alkyl.
The weight ratio of quaternary ammonium compound(s) to hydrogen peroxide in the above method is from 1:100 to 2:1, preferably from 1:20 to 1:1.
The following non-limiting examples will illustrate the invention. All concentrations in percent or ppm are by weight unless otherwise noted.
All solutions were diluted in water of 400 ppm hardness and all concentrations were expressed in ppm. Each of the solutions was tested in 4 replicates as described below. The numbers in Table 2 below indicate the number of “positive” cells or ineffective disinfection of 4 replicates. Various contact times noted on the tables were evaluated.
Flat bottom microplate wells were inoculated with 15 μL each of a suspension of 10% P. aeruginosa+5% fetal bovine serum in a saline solution, 4.5×107 cfu/mL using a Quadra Tower 400 Series High Throughput apparatus (Tomtec Inc., Hamden, Conn.). The plates were dried with cover open for 40 minutes at 36° C. Then, 120 μL of each test substance was transferred from the deep-well block to the test wells. The test organisms were exposed to the test substance for different contact times, after which the substances were removed with the Quadra and 150 μL of modified AOAC Letheen neutralizer+0.5% Na thiosulfate/growth broth was added to each well. The microplates were incubated at 36° C. for 24 hours and scored for growth/no growth.
| Number | Date | Country | Kind |
|---|---|---|---|
| 07005428 | Mar 2007 | EP | regional |
This application has priority benefit of U.S. Provisional Application No. 60/898,411, filed on Jan. 31, 2007, and of European Patent Application No. EP 07005428, filed on Mar. 16, 2007.
| Number | Date | Country | |
|---|---|---|---|
| 60898411 | Jan 2007 | US |
