Concentrates of disinfecting agents on the basis of lower fatty acids

0001The invention relates to disinfectant concentrates which contain unbranched and / or branched saturated aliphatic carboxylic acids having 5 to 14 carbon atoms, emulsifiers and, if appropriate, water and small amounts of perfumes, waxes, polymers and similar additives which modify the use properties.

0002The antimicrobial effect of saturated and unsaturated aliphatic carboxylic acids is known from numerous publications. In JJ Kabara, AOCS Monograph No.5, pp. 1 ff. (1978), numerous papers are reported and structure-activity relationships are explained: saturated carboxylic acids with 10 to 12 carbon atoms, monounsaturated carboxylic acids with 16 carbon atoms and polyunsaturated carboxylic acids with 18 carbon atoms show optimal antimicrobial activity.

0003The influence of pH on the bactericidal activity of certain fatty acids is the subject of a referential work by JV Karabinos and HJ Ferlin (J.Amer. Oil Chem. Soc. 31, 228 (1954)). Fatty acids with 8 to 12 carbon atoms are cited as the most effective in inhibiting the growth of mold, while carboxylic acids with odd carbon numbers between 7 and 13 and their sodium salts have been used as excellent fungistats.

0004US Pat. No. 2,190,714 claims the use of straight-chain and / or branched fatty acids having 3 to 12 carbon atoms as a fungistatic preservative in the food industry. US Pat. No. 2,466,663 describes the use of octanoic acid and its salts at pH values ​​from 4.5 to 10.5 as a fungicide in solutions, ointments and powders for use on living tissue, for example on the skin.

0005CA-PS 1 098 039 claims the protection of infusion solutions which are used for parenteral nutrition against infestation by fungi and bacteria by the addition of free organic acids, in particular saturated or unsaturated fatty acids with 4 to 12 carbon atoms. US Pat. No. 4,343,798 describes the antimicrobial activity of ointments containing aliphatic carboxylic acids having 5 to 12 carbon atoms, which, however, additionally contain corticosteroid components.

0006JV Karabinos et al (cited above) also refer to a study on the inhibition of bacterial metabolism by various cationic and anionic detergents. Their inhibitory effect is strongly influenced by the hydrogen ion concentration. The authors of this study showed that anionic detergents show their best inhibitory activity in the acidic pH range.

0007EP-A 0 068 552 describes locally applicable antimicrobial agents which contain fatty acids with 5 to 12 carbon atoms, preferably with 8 to 10 carbon atoms, and their salts, and are not greater than aqueous gels and aqueous lotions with a pH are formulated as 5.

0008So far, no reference to the use of fatty acids for instrument disinfection or surface disinfection can be found in the literature.

0009While only alcoholic preparations (ethanol, n- and i-propanol) and agents based on PVP-iodine, which were able to assert themselves due to their extremely rapid onset of action, are of importance for surgical and hygienic skin and hand disinfection Proper surface disinfection, which also corresponds to the corresponding test guidelines of the German Society for Hygiene and Microbiology (DGHM), According to the current state of the art practically only with preparations based on aldehyde mixtures (formaldehyde, glutaraldehyde, glyoxal), aldehyde mixtures with quaternary ammonium salts or phenols, see. DE-OS 32 05 318, p. 3, lines 5 ff. And Hyg. And Med. 7, 467 ff (1982). In addition to the fact that these agents do not always have the required effect, their vapors lead to considerable odor nuisance, which can even result in irritation or irritation of the mucous membranes.

0010Surprisingly, it has now been found that branched and / or undisclosed fatty acids are on a par with, or in some cases even superior to, the conventional agents used for surface or device disinfection in terms of the speed of their onset of action. In addition, they are better tolerated and absolutely toxicologically safe. They can also be used in significantly lower application concentrations compared to known disinfectants and have significantly better galenic requirements.

0011However, if one tries to test linear and / or branched, saturated aliphatic fatty acids according to the guidelines of the DGHM intended for this purpose for their effectiveness for surface or device disinfection, one finds that the majority of them themselves in a concentration of 1% in water without additional additives are unsuitable for disinfection tasks. This is primarily because the solubility of the fatty acids in water or in the other test media is too low to achieve the dissolution of an amount that is sufficiently effective for disinfection. This reason is all the more decisive as conventional agents for surface or device disinfection are only sold as concentrates, which the user dilutes with water to the required application concentration immediately before application.

0012It was therefore the task to produce disinfectant concentrates based on fatty acids, which by dilution with water result in preparations which can be dissolved in water according to the guidelines of the DGHM and which meet the corresponding requirements of the DGHM for surface and / or device disinfection in terms of effectiveness, cleaning value and toxicity.

0013This object is achieved in that unbranched and / or branched, saturated aliphatic carboxylic acids are solved in water with the aid of emulsifiers and / or solubilizers, so that concentrates are formed which result in homogeneous solutions or suspensions when dissolved in water.

0014The invention thus relates to disinfectant concentrates which contain unbranched and / or branched, saturated aliphatic carboxylic acids having 5 to 14 carbon atoms, emulsifiers and, if appropriate, water and small amounts of perfumes, waxes, polymers and similar additives which modify the use properties.

0015Unbranched, saturated aliphatic carboxylic acids such as valeric acid, caproic acid, oenanthic acid, caprylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, tridecanoic acid or myristic acid or else mixtures of two or more of these acids are used as carboxylic acids for the purposes of the present invention.

0016However, there are also branched, saturated aliphatic carboxylic acid, such as 2-methylbutyric acid, isovaleric acid, 2-methylvaleric acid, 2-ethylbutyric acid, isooctanoic acid, isodecanoic acid, isotridecanoic acid, and also comparable branched carboxylic acid, and also mixtures of these acids or mixtures of branched and unbranched aliphatic carboxylic acids. Technical mixtures of aliphatic fatty acids with 5 to 14 carbon atoms can advantageously be used.

0017The disinfectant concentrates according to the invention contain the fatty acids mentioned in an amount of 5 to 95% by weight, based on the finished concentrate.

0018In preferred embodiments, the carboxylic acids are contained in an amount of 10 to 60% by weight.

0019The disinfectant concentrates according to the invention also contain emulsifiers, with the aid of which the above-mentioned fatty acids are soluble in water to give clear solutions or homogeneous suspensions. In a preferred embodiment of the present invention, the emulsifiers are simultaneously surfactants, as a result of which the disinfectant concentrates, after they have been diluted to a concentration suitable for the application, simultaneously have a high cleaning power.

0020Surprisingly, it was found that using such emulsifiers not only improved the solubility of the fatty acids mentioned, but also increased the germicidal effect.

0021Anionic, nonionic and / or cationic surfactants can be used as emulsifiers for the purposes of the present invention. In particular, alkali salts of fatty acids, sulfonated fatty acids and / or sulfonic acids containing an aromatic ring are used.

0022In a preferred embodiment of the invention, part of the fatty acids used according to the invention can be saponified by adding aqueous alkali metal hydroxide solution to the alkali salt of the respective fatty acid, which then takes on the role of an emulsifier.

0023In addition, organic compounds containing several hydroxyl groups, for example glycerol, and also mono- or poly-ethoxylated fatty acids or fatty amines or their ammonium salts and also mixtures of these compounds can be used as emulsifiers. Pentaoxethylstearylammonium chloride or ethoxylated oxystearic acid, for example, are used as compounds of this class.

0024The emulsifiers mentioned are used in an amount of 5 to 30 percent by weight, based on the finished disinfectant concentrate. In preferred embodiments of the present invention, two different emulsifiers of the classes mentioned are used in an emulsifier / co-emulsifier weight ratio of 2: 1 to 10: 1.

0025The disinfectant concentrates according to the present invention also contain, in small amounts, fragrances, waxes, polymers and similar additives which modify the use properties of the concentrates in use.

0026In today's floor care, especially plastic floors, not only do you want the cleaning agent to have a perfect cleaning effect, but you also strive to apply a protective film made of a wax or polymer emulsion to the floor in the same operation. A particularly labor-saving disinfectant for floors should therefore also contain a polymer emulsion for the formation of a protective film in addition to a cleaning effect. Suitable wax emulsions are, for example, LGE montan wax emulsions (BASF), suitable polymer preparations are, for example, Licomer A 53^R, a dispersion of an acrylate copolymer (from Hoechst).

0027The disinfectant concentrates according to the invention can be excellently diluted with tap water to any desired application concentration. Mostly clear solutions are created.

0028The germicidal effect of both the concentrates and the respective dilutions of the concentrates are tested in the area test or in the suspension test according to the guidelines of the DGHM. It was found that disinfectant concentrates with carboxylic acids in the range from 8 to 10 carbon atoms have a maximum activity against bacteria and fungi. These examples in particular also show that the germicidal action of the fatty acids can surprisingly be greatly increased by the addition of emulsifiers.

0029The invention is illustrated by the following examples.

Examples 1 to 19

0030The concentrates likewise given in Table 1 were prepared by stirring together the fatty acid, emulsifier and water ingredients indicated in Table 1.<tables id="tabl0001" num="0001"><img file="EP0135898A2_D0001.tif" /></tables>(Continuation)<tables id="tabl0002" num="0002"><img file="EP0135898A2_D0002.tif" /></tables>

0031Comments on Table 1:<ul id="ul0001" list-style="none"><li>a) List of emulsifiers and co-emulsifiers from Examples 1-16:</li><li>A Na dodecylbenzenesulfonate</li><li>B dodecylbenzenesulfonic acid</li><li>C Genamin KS 5: 21% solution of pentaoxethylstearylammonium chloride (Hoechst)</li><li>D Na cumene sulfonate</li><li>E Cremophor HS 15^R: Ethoxylated oxystearic acid (BASF)</li><li>F alkylphenol with 8EO</li><li>G 65% solution of sodium ddisooctyl sulfosuccinate Steinapol SB-DO 70^R (Rewo)</li><li>H coconut fatty acid diethanolamide<ul id="ul0002" list-style="none"><li>b) Carboxylic acid -8.9.1 (Hoechst)</li><li>c) EDENOR V 85 KR: fatty acid mixture (60% C8 and 35% C10) (Henkel)</li></ul></li></ul>

Example 20

0032Germicidal effect of dilutions of the concentrates of Examples 1 to 19 in the suspension test

0033Disinfectants with test concentrations according to Table 2, column 2 were prepared by diluting the disinfectant concentrates of Examples 1 to 19 with water of standardized hardness (WSH).

0034The test germs were pre-grown in casein peptone soy flour peptone solution and mixed with the agent to be tested. The initial germ count in the disinfectant-test germ mixture was 1 x 10⁷ up to 5 x 10⁷/ ml.

0035After exposure times of 2.5, 5, 10, 20, 30 and 60 min, 0.1 ml was removed from the reaction vessel and transferred to casein peptone-soybean meal peptone solution with a detergent (tween-lecithin-histidine). The germicidal effect was considered to have been demonstrated if there was no multiplication in the subculture.

0036Table 2 contains the killing times in minutes at which there was no further increase in the subculture for the first time.<tables id="tabl0003" num="0003"><img file="EP0135898A2_D0003.tif" /></tables>

Comparative Examples 1-5

0037The following comparative examples 1 to 5 were carried out as in example 20. However, the fatty acids specified in Table 3 below were used as disinfectants to be tested in the corresponding concentrations without the addition of an emulsifier.

0038The specified kill times (min) are those times in which there was no further multiplication in the subculture for the first time.<tables id="tabl0004" num="0004"><img file="EP0135898A2_D0004.tif" /></tables>

Remarks:

a) Technical mixture of C

8

- and C

10

-Carboxylic acids

Example 21

0039Germicidal effect of dilutions of the concentrates of Examples 1 to 8 in the area test on PVC

0040By diluting with water of standardized hardness (17 ° DH), WSH, disinfectant solutions were prepared from the disinfectant concentrates of Examples 1 to 8 to concentrations corresponding to Table 4, column 2 below.

0041The test germs (Staph. Aureaus and E. coli) were pre-grown on casein peptone soy flour peptone agar and washed off with casein peptone soy flour peptone solution.

0042Each 0.1 ml of the germ suspension was distributed with a glass spatula onto a 5 cm x 5 cm PVC floor covering, which was sprayed with the respective test solution after the test germs had dried on. After exposure times of 5, 10, 20, 30 and 60 min, a survival germ was checked using a smear culture. Efficacy on the PVC surface was proven if less than 10 colonies of the test germ were visible on the subcultures.

0043Columns 3 and 4 in Table 4 below show the exposure times after which for the first time less than 10 colonies of the test germ became visible on the subcultures.<tables id="tabl0005" num="0005"><img file="EP0135898A2_D0005.tif" /></tables>

Comparative Examples 6-8

0044The following comparative examples 6 to 8 were carried out in accordance with example 21. However, only the carboxylic acids listed in Table 5 below without an emulsifier were used for disinfection.

0045<tables id="tabl0006" num="0006"><img file="EP0135898A2_D0006.tif" /></tables>

Example 22

0046A disinfectant concentrate which was mixed with tap water in a ratio of 1: 9 was prepared by stirring together 2 parts by weight of caprylic acid, 3 parts by weight of glycerol and 15 parts by weight and 0.5 part by weight of NaOH. A cloudy caprylic acid emulsion with a pH of approx. 6.0 was formed.

0047The antimicrobial effect of this disinfectant solution was tested in a suspension test in accordance with Example 20.

0048The killing times for numerous test germs can be found in Table 6 below.<tables id="tabl0007" num="0007"><img file="EP0135898A2_D0007.tif" /></tables>

Example 23

0049A concentrate according to the invention with a care effect for floors is produced by stirring together 15% octanoic acid, 2% Na dodecylbenzenesulfonate and 83% of a 21% aqueous montan wax emulsion (trade name LGE wax, BASF).

0050If a 0.5% solution of this concentrate is tested for disinfection according to Example 21, then after 30 minutes in the subculture at Staph. aureus and E. coli no longer propagate. An analogous disinfectant concentrate can be used with a Licomer^R-Dispersion can be produced.