WATER-DILUTABLE DISINFECTANT COMPOSITION

Abstract: A water-dilutable antimicrobial composition char­ acterised by the following ingredients: a) an alpha-substituted aliphatic acid with 2-6 carbon atoms, where the substituents are selected from chloro, iodo, cyano, nitro, amino, imino, thiohydroxy and hydroxy b) an aliphatic alcohol containing six to twelve carbon atoms. The composition may include a solubilising agent for the aliphatic alcohol. The composition may be in the form of a concentrate, or an in-use-solution of use in the disinfection of hard surfaces in the food and beverage, including brewery, industries and also in hospitals, kitchens and in the home.

Description: WATER-DILUTABLE DISINFECTANT COMPOSITION This invention relates to a water-dilutable disinfectant composition. Various compounds are known to have a disinfectant activity by themselves or in combination with other compounds. It is a continuing problem to find compositions which meet the particular requirements which are demanded in practice by industry. This invention is directed to the problem of disinfection of hard surfaces in the food and beverage, including brewery, industries and also in hospitals, kitchens and in the home. Amongst the compounds known as having some antimicrobial (disinfectant) activity may be mentioned bromoacetic acid which is used in combination with sulfuric acid and phosphoric acid. Also aliphatic alcohols have been described in the literature as having antimicrobial activity. We have found that the activity of a composition which contains as a first component an alpha-substituted aliphatic acid, which is a chloro, iodo, cyano, nitro, amino, imino, thiohydroxy or hydroxy carboxylic acid, and as a second component an aliphatic alcohol with six to twelve carbon atoms, is unexpectedly greater than the activity of either component alone. Broadly therefore the invention provides disinfectant compositions which include said first and said second component. The composition in order to be water dilutable will also in practice contain a solubilizing agent, as more fully described below. Of the two components mentioned above the substituted acid is preferably hydroxyacetic (glycolic) acid. The alcohol which makes up the second component, may be an aliphatic alcohol with six to twelve carbon atoms, preferably an alcohol containing from 8 to 12 carbon atoms Preferred alcohols are n-decanol and n-octanol, which may be used in admixture. In a preferred feature of the invention the composition and substituted acetic acid is glycolic acid and the alcohol is n-decanol and/or n-octanol. The compositions according to the invention should be dilutable with water and therefore solubilising agents are preferably included to solubilise the aliphatic alcohols and to achieve stable formulations. The solubilising agents are not intended to contribute significantly to the microbicidal activity. In principle any compound which is capable of solubilising the alcohols, can be used. Examples of classes of compounds which may be used include the following: n-alkyl sulfonates alkyl aryl sulfonates aryl sulfonates fatty alcohol ethoxylates fatty alcohol ethoxypropoxylates fatty alcohol sulfates ethylenediamine ethoxylates ethylenediamine ethoxypropoxylates phenyl poly ethoxylates. These compounds may be used in salt form, e.g. as sodium salts where appropriate. The compositions according to the invention are active at neutral to acidic conditions. In general no ps-adjustment of the in-use solution is necessary for improving or maintaining of the antimicrobial activity. However, for particular applications pH-adjustment may be necessary. The addition of inorganic or organic acids means that the pH of the use-solution becomes more independent of both the properties of the water, used for dilution, and of the C02-partial pressure, which may be quite high in brewery tanks and other facilities where this disinfectant composition may be used. It may also facilitate control of the addition of the composition by measurement of conductivity. Therefore a certain acid content of the formulation will widen the range of applications. The preferred acid for this purpose is phosphoric acid, but also sulfuric and nitric acid can be used. Organic acids such as acetic or citric acid can be used also. The composition according to the invention may also contain auxiliary substances such as dyes, perfumes, surfactants and defoamers. For each composition according to the invention the substituted acid and the aliphatic alcohol exists an optimized ratio of both components. The content of solubilising agent depends on its structure and the alcohol content. The composition according to the invention preferably consists of the following on a wlw basis. a) Chloro, iodo, cyano, nitro, amino, imino, thiohydroxy and/or hydroxy carboxylic acid; 0.4 - 70% (preferably 0.4 - 50.0%) b) Aliphatic alcohol C6-C12; 0.1 - 50% (preferably 1.0 - 40.0%) c) Solubilising agent for the alcohol; O - 50% (preferably 5.0 - 15%) d) Inorganic or organic acids for pH-adjustment of the use-solution: O - 906 (preferably 5 to 60%) e) Auxiliary substances such as dyes, perfumes, surfactants and defoamers, water. The following examples of concentrates containing 2-hydroxy acetic acid (glycolic acid), in which the percentages are on a weight basis, are given by way of illustration only: Concentrates Example 1 2-hydroxy acetic acid 1 n-decanol 3 cene sulfonate, sodium salt 12 enyl poly ethoxylate sodium salt 3 water 81 Example 2 2-hydroxy acetic acid 5 n-decanol 2 phosphoric acid 40 n-decyl sulfonate, sodium salt (406) 15 water 38 The antimicrobial activity of the active components of the composition by themselves and in combination were tested and the results are given in the following table. In this table there is also shown a mixture of 2-hydroxyacetic acid, n-decanol and n-decylsulfonate sodium salt which is according to the invention. Microbicidal activity of ingredients used by themselves in admixture and in admixture according to the invention (dulutions done in tap water 300 ppm water hardness, concentrations given in mg/l, activity given in log10-reduction after 5 min. contact time at 4 C) Chemicals 2-Hydroxy acetic acid 250 500 n-Hexanol 100 n-Octanol 100 n-Decanol 100 n-Dodecanol 100 n-Octylsulfonate sodium salt (40%) 1000 n-Decylsulfonate sodium salt (40%) 1000 1000 1000 1000 Alkylarylsulfonate sodium salt 1000 Cumene sulfonate sodium salt 1000 Phenylpolyethoxylate sodium salt 1000 Fatty alcohol sulfate sodium salt (50%) 1000 Phosphoric acid 4x105 Killing capacity in log10 against Saccharomyces cerevisiae < 0,5 < 0,5 < 0,5 2 1 < 0,5 < 0,5 < 0,5 < 0,5 < 0,5 Microbicidal activity of ingredients used by themselves in admixture and in admixture according to the invention (dilutions done in tap water 300 ppm water hardness, concentrations given in mg/l, activity given in log10-reduction after 5 min. contact time at 4 C) Examples 1 2 Chemicals 2-Hydroxy acetic acid 250 250 250 50 250 n-Hexanol n-Octanol n-Decanol 100 150 10 n-Dodecanol n-Octylsulfonate sodium salt (40%) n-Decylsulfonate sodium salt (40%) 1000 1000 750 alkylarylsulfonate sodium salt cumene sulfonate sodium salt 600 Phenylpolyethoxylate sodium salt 150 fatty alcohol sulfate sodium salt (50%) 1000 Phosphoric acid 375 2000 Killing capacity in log10 against Saccharomyces cerevisiae < 0,5 < 0,5 > 5,3 > 5 > 5 The comparative experiments were carried out on yeast species (Saccharomyces cerevisiae) since these are more difficult to kill than bacteria. The compositions according to the invention also have a very significant activity against bacteria. The results demonstrate the unexpectedly higher activity obtained by the combination of the two active ingredients. The formulations given in the Examples will be diluted to provide in-use solutions when required. A suitable dilution will be selected to give an effective concentration. Thus, for exam pie the formulations may be diluted on the basis that a quantity of 0.50% by weight is diluted with water to 100; by weight, that is to say a dilution of 200. This is the dilution used for the formulations in the tests reported in the tables. However, any suitable dilution may be used and solutions of intermediate dilutions may be prepared. The compositions according to the invention are useful for cold disinfecting and in particular for socalled CIP (cleaning in place) systems where the plant to be disinfected is not dismantled. This is often the case in milk-processing factories and breweries. The temperature of operation is, for such cleaning, of the order of 40C.

Claims: CLAIMS: 1. A water-dilutable antimicrobial composition characterised by the following ingredients: a) an alpha-substituted aliphatic acid with 2-6 carbon atoms, where the substituents are selected from chloro, iodo, cyano, nitro, amino, imino, thiohydroxy and hydroxy b) an aliphatic alcohol containing six to twelve carbon atoms. 2. A composition as claimed in claim 1 in which the substituted aliphatic acid is monohydroxyacetic acid. 3. A composition as claimed in claim 1 or claim 2 in which the alcohol contains from 8 to 12 carbon atoms. 4. A composition as claimed in claim 3 in which the alcohol is n-decanol and/or n-octanol. 5. A composition as claimed in any of claims 1 to 4 in which the composition also includes a solubilising agent for the aliphatic alcohol. 6. A composition as claimed in claim 5 in which the solubilising agent is one or more of the following: fatty alcohol ethoxylates, fatty alcohol ethoxypropoxylates, ethylenediamine ethoxylates, n-alkylsulfonates, alkyl aryl sulfonates, aryl sulfonates, fatty alcohol sulfonates and phenyl poly ethoxylates. 7. A composition as claimed in any of claims 1 to 6 which also contains an inorganic or organic acid. 8. A composition as claimed in claim 7 in which the acid is phosphoric acid. 9. A composition as claimed in any of claims 1 to 8 in which the ratio of the substituted aliphatic acid to the alcohol is optimized. 10. A composition as claimed in any of claims 1 to 9 in the form of a concentrate. 11. An in-use solution or a solution of intermediate concentration made by the dilution of a composition as claimed in claim 10 with water. 12. A composition as claimed in any of claims 1 to 11 consisting of the following, on a wlw basis: w/w a) 2-substituted aliphatic acid 0.4 - 70% b) aliphatic alcohol C6-C12 0.1 - 50% c) solubilising agent for (b) O - 50% d) inorganic and/or organic acid 0 - 90% e) auxiliary agents, that is dyes, perfurmes, surfactants and/or defoamers, water to 100% 13. A composition as claimed in claim 1 substantially, as herein described with reference to any one of the examples. 14. A method of disinfecting surfaces which comprises applying to said surface as an in-use solution a composition as claimed in any of claims 1 to 13. 15. Surfaces disinfected by the method of claim 14.

Inventors: LICHTENBERG, FLORIAN, RYSIOK, THOMAS
Applicants: DIVERSEY GMBH
Application year: 1986
Main classification: A01N37
IPC codes: A01N37, A01N59