US2183037A - Germicidal detergent - Google Patents

Description

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UNITED STATES PATENT OFFICE GERMICIDAL DETERGENT Milward Bayliss, Hurloek, Md., and John L.

Wilson, St. Paul, and Erling J. Ordal, Minneapolis, Minn., assignors to Economics Labora'tory Inc., St. Paul, Minn., a corporation of Delaware No Drawing. Application May 10, 1935,

.Serial No. 20,766

3 Claims.

This invention relates to improvements in germicidal detergent compositions and includes such compositions in a concentrated or dry state, such as a dry powder, as well as germicidal solutions of such compositions.

The new compositions are valuable for use in homes, hotels, restaurants, hospitals and institutions, as well as in the beverage and dairy industries, where a germicidal action as well as a detergent action is desired.

The new germicidal detergent compositions are in general admixtures of alkalies or buffer salts and wetting agents of the character hereafter referred to, in such proportions that when, for example, a solution is made of the composition containing from to 3% of the composition the solution will have a high pH value, in excess of about'11.5.

The buffer salts which are used in the new composition are alkaline salts or alkalies, such, 'as'carbo'nates, phosphates or silicates, etc., used in such amounts and proportions as will give to the final solution the desired pH value. Among such buffer salts may be mentioned sodium carbonate, mono-sodium-phosphate, disodium phosphate, tri-sodium phosphate, sodium silicates, etc.

In using these buffer salts, in making the new composition, the proper pH is obtained by a selection of the buffer salts employed which may, in some cases, be a single salt or salts of the same acid, or salts of different acids, etc. For example, the proper pH may be obtained by the use of a mixture of various phosphates and carbonates, or various phosphates and silicates, or carbonates and silicates, or by mixtures of phosphates, carbonates and silicates; as well as by mixtures of various phosphates alone, or carbonates alone, or silicates alone. Similarly, other salts besides phosphates, carbonates and silicates may be used to obtain the proper pH.

The wetting agents which are used, together with the alkaline salts, in making the new compositions, are in general wetting agents of a character which are superior to and distinguished from ordinary soap. Among the important wetting agents which are employed in accordance with the present invention, are sulfonated products such as sulfonated hydrocarbons or sulfonated higher alcohols and sulfonated oils which are free from a carboxyl (free or neutralized) group or which have a carboxyl group blanked or made ineffective. Certain phenolic or alcoholic Wetting agents are also included.

The sulfonated higher fatty alcohols have re- I cently been introduced in commerce as wetting agents and these are well adapted for use in the new composition of the present invention. The

higher alcohols are obtainable by catalytic reduction, under proper conditions, from the fatty acids'of natural fats and their esters. When sulfonated with concentrated sulfuric acid under proper conditions they yield products known in the trade as fatty alcohol sulfates or half sulfuric acid esters of the fatty alcohols. While referred to as sulfonated fatty alcohols, they are more properly referred to as alkyl esters of sulfuric acid having for example the general formula R.O.SO2.ONa, where R is a straight chain aliphatic radical containing 8 or 10 carbon atoms or more. A simpler formula for these sulfonated fatty alcohols is R.SO4Na, representing the'sodium'salts of the alkyl sulfates, where R is a long chain aliphatic radical. Among these sulfonated fatty alcohols may be mentioned sodium lauryl sulfate, sodium octadecyl sulfate, and sodium oleyl sulfate. The technical grade of sulfonated JauryL alcohol ,is known. as sulfonated Lorol and the technical grade of sulfonated oleic or oleyl alcohol is known as sulfonated Ocencl.

Where the alcohol'sulfonated is an unsaturated alcohol the sulfuric acid may react by addition at the double bond to form sulfonicor sulfate derivatives as well as by' reaction with the hydroxyl group to form the ester. The products may be in part true sulfonic acids or may contain true sulfonic acids as well as sulfates or suifuric acid esters. When chloro-sulfonic acid is used for sulfonating the unsaturated alcohols true sulfonic acids are produced and where the al coholic hydroxyl is converted into a sulfate the sulfonated alcohol may contain both a sulfonic and a sulfate group. The sulfonated higher alcohols are marketed under various trade names, such as Gardinols, Brilliant Avirols, Orvus,Dreft, etc. The sodium oleyl sulfate, for example, is

marketed under the trade name Gardinol CA and' the lauryl sodium sulfonate is marketed under the trade name Gardinol WA. The higher fatty alcohol sulfonates derived from stearyl and cetyl alcohols are marketed under the trade names Brilliant- Avirols L142, L144 and L168. These various sulfonated alcohol products are used in the form of their sodium salts. I

The sulfonated higher alcohols, although produced by the sulfonating of the alcohols, are in.

sulfonic acid is sold under the trade names Neomerpin, Erkalin and Alkanol SA. The alkylated naphthalene sulfonic or sulfuric acid products are used in the form of their sodium salts, for example, the sodium isopropyl naphthalene sulfonate. Other sulfonated hydrocarbons are represented by sulfonated abietenes, or suli'onated abietanes, for example, sodium abietene sulfonate; or the sodium salt of sulfonated abietanes (hydrogenated abietenes), The naphthalene sulfonic acid compound may be combined with one of the fatty sulfonic acid compounds, as in Oranit BN Extra. The. sodium salts of naphthalene 'sulfonic acid derivatives are also marketed under the trade name Alkanol. Sodium tetralin sulfonate is also marketed under the trade name Alkanol S. Sodium tetrahydro naphthalene sulfonate is the active wetting agent in Alkanol PF.

Certain sulfonated wetting agents are made from oleic acid and isethionic acid. The prodnot having the formula CH3 (CH2) 7CH 2 CH CH2) 7COOCH2CH2SO3N8.

is sold under the trade name Igepon A. A somewhat different product having the formula CHJ(CHI)7CH:CH(CH2)1CONCHZCHZSOSNB I is sold under the trade name Igepon T. Igepon T in a solvent is sold under the trade name Laven-' sold in the trade as Avirol AH Extra. Sulfonated fatty oils are sold under the trade names Nopco Castor and Intrasol.

The sodium salt of the sulfuric ester of oleic gclid amide is sold under the trade name Humeco C.

The various wetting agents are used in the new composition in the form of their sodium salts together with the buffer or alkaline salts in such proportions that there will be present in the solution made of the composition only a small percentage of the wetting agent together with such amount of the buffer salt as will give to the solution. a Qgh pH value of around 11.5 or higher. While the wetting agents themselves are relatively inefiective as germicides, the compositions in which they are used together with the alkaline salts are highly eifective, such that solutions from the new compositions are excellent detergents and exhibit sufficient germicidal properties so that they can also be used as germicides. In general the solutions made from the new compositions will contain .from around to 3% of the composition, although the amount can be somewhat varied.

The new compositions are advantageously compounded and marketed in the form of'a dry powder containing the wetting agent, where available in a dry powdered form, together with'the pulverulent alkaline salt, in the form of an intimate and substantially homogeneous mixture, such that a definite weight of the powdered composition can be used to give a solution of definite strength and proportions of the different ingredients. Such a dry mixture of the ingredients can be readily produced, handled, shipped and stored and a definite amount measured or weighed out for use in producing germicidal detergent solutions.

The particular alkali salt or salts used in the composition for giving it the desired high pH value can be varied and are best defined by the pH value of the resulting solution rather than by attempting to give the various combinations of chemicals which will provide the desired high pH value.

In testing the solutions of the new composition, we have used the following test: The dry mixture, containing the ingredients of the composition, is made into a solution of from A to 3% strength. To 5 cc. of this solution is added cc. of a 24 hour culture of the standard test organism, Staphylococcus aureus (Insecticide Board strain). Before the culture is added to the test solution, it is brought to the required temperature; the temperature we have used has been 37 C. or in some cases a higher temperature. After the culture has been in the test solution for five minutes, a 4 mm. loopful is removed and added to a tube of molten agar at a temperature of 45 C-. and the mixture is poured into a Petri plate. The plates are incubated for 48 hours, at the end of which time a count is made of the colonies appearing on the plate. The number of organisms originally added to thetest solution is in the neighborhood of five hundred millions (500,000,000). If no organisms are killed, the loopful removed will contain an excess of 10,000 organisms, and therefore the number of colonies appearing on the plates will be, in excess of 10,000. If some of the organisms are killed, the number of colonies appearing on the plates will be less than 10,000. In the data reported in the following examples, the numbers indicate the colonies appearing on the test plate after 48 hours of incubation. Similar tests were made using Eberthella typhi (Hopkins strain).

As illustrating the action of water alone, sodium lauryl sulfate alone, in various amounts, sodium carbonate, trisodium phosphate, sodium meta-silicate and sodium sesqui-silicate, the following table gives the results of tests made as above described, with these various substances, the tests being carried out with Staphylococcus aureus (F. D. A. strain) at a temperature of 37 C. and with a plate count after 5 minutes and 10 minutes respectively. The organism employed and the temperature and time of the test are in accordance with the standards adopted by the Federal Food .and Drug Administration (F. D. A.)

Plate counts Solution tested.

5 min 10 min.

Water alone 10, 000+ 10,000+ 0.01%.sodium lauryl sulfate 10. 000+ 10, 000+ 0.1% sodium lauryl suliate 10. 000+ 10. 000+ 1.0% sodium lauryl sulfate 10,000+ 10,000+ 2.0% sodium lauryl sulfate 10. 000+ 10.0004- 1% sodium carbonate (NmCOa) (DH=11.4) 10, 000+ 10. 000+ 2% sodium carbonate (NazOOz) (pH=1l.5) 10. 000+ 10. 000+ 1% T. S. P. (trisodium phosphate) (N8zPO4.12HzO) (pH=12.0) 10,000+ 10.000+

o T. S. P. (trisodium phosphate) (N8zP04.12Hz0) (pH=l2.2) 3, 000+ 3,000+ 2% Metso (sodium metasilicate) (NagSiOafiHzO) (pH=12.6) 1.800 900 1% Metso (sodium metasilicate) (NazSiO;.5H10)(pH=12.3) 10, 000+ 8, 000+ 1% Metso 99 (sodium sesquisilicate (pH=12.6) 2, 000 800 LJLI From this table it will be seen that the various alkaline salts alone are ineffective at this temperature and in these concentrations as germicides and that the sodium lauryl sulfate is likewise ineifective. However, when sodium lauryl sulfate or.other effective wetting agents, such as those above referred to are used in combination with the alkaline salts, a pronounced germicidal action as wellas detergent action is obtained. The germicidal action of sodium lauryl sulfate in various amounts used together with trisodium phosphate and sodium meta-silicate (Metso) are illustrated by the following table, the organism used, the temperature, etc., being those above referred to:

5 min. 0 min.

+.0l% sodium lauryl sulfate +.01'5% sodium lauryl sulfate +.02%sodium lauryl sulfate +.05%'sodium lauryl sulfate 2% 'l. +.l% sodium lauryl sulfat 2% 'l. +.5% sodium lauryl sulfate. 1% Metso +01% sodium lauryl sulfate 1% Metso +0.05% sodium lauryl sulfate 1% Metso +0.02% sodium lauryl sulfate 1% Metso +0.015% sodium lauryl sulfate 1% Metso +0.01% sodium lauryl sulfate 2% Metso +01% sodium-lauryl sulfate. 2% Metso +0.05% sodium lauryl sulfate 2% Mctso +0.02% sodium lauryl sulfate 2% Metso +0.0l5% sodium lauryl sulfate. 2% Metso +0.01% sodium lauryl sulfate M ooccosmwooococw Plate counts Solution tested 5 min. 10 min.

The results of tests made as above described with compositions made with various wetting agents and with sodium meta-silicate or sodium carbonate, in accordance with the tests above referred to are given in the following table:

Plate counts Solution tesferl 5 min. 10 min.

W'ater alone 10, 000+ 10, 000+ 1% Metso (sodium metasilicate) (N8zSiOa.5H:O) (pl2 [=12.3) 10. 000+ 8,000 1% Metso+.1% Erkal1n 125 15 1% Metso+.2% ErkalilL 0 0 1% Metso+.l% Alkanol B. 200 30 1% Metso+.2% Alkanol B. '5 0 1% Metso+.2% Merpentine 6 0 1% Mctso+.2% Alkanol SA l5 3 1% Metso+.2% Orvus (sodium lauryl sulfate). 20 0 1% Metso+0.2% sod iumstearyl sulfate 40 0 1% Metso+0.2% Alkanol PF. 40 0 1% Metso+0.2% Laventine KB 125 2 1% Metso+0.2% sodium oleyl sulfate 250 3 1% Metso+0.2% Humcctol C .i 300 5 Another series of tests made with compositions containingsodium meta-silicate and a fraction of a percent of various wetting agents is indicated by the following table, the temperature maintained in these tests being 45 C. and the same organism being used as in the tests laLJi'ui w ry-g above referred to, the last three solutions representing phenol solutions used as control:

Solution tested 5 min. 10 min.

MOOOCOOQOO ooooopcooco From the above examples it will be noted that the solution tested contained only a small fraction of a percent of the wetting agent and only around 1 or 2% of the total composition, but the solution was nevertheless effective as a germicide in addition to its detergent properties.

,The wetting agents used in the composition impart improved penetrating properties to the composition, making the composition effective in its detergent as well as its germicidal properties.

In general the amounts of wetting agents will be around 0.002% or higher, the amount to be used 3 in practice depending on the wetting agent used,

on the pH of the solution, on the temperature of the solution, and on the length of time of contact with and the kind of organisms to be killed. 1

In general the amount of the wettiiig'ag'fifiwill form only a small proportion of the dry mixture, where the composition is prepared and marketed in dry form, the greater part of the composition being made up of the alkaline or buffer salts of such nature and amount as will impart to the solution of the composition the desired high pH value. I

The new compositions are useful for many purposes as in hospitals or institutions, where germicidal detergents are important, as well as in 45 hotels and restaurants for dish-washing and other purposes, and in various industries such as the beverage and dairy industries, where it is important, for example, to sterilize the bottles and containers as well as to wash them.

' In some cases it is advantageous to use a plu-. rality or mixture of active wetting agents, instead of only one active wetting agent, in the new composition. The active wetting agents differ somewhat in their detergent or sudsing 55 properties, and it is sometimes advantageous to add a wetting agent which is less ineffective in the germicidal properties which it imparts to the composition together with another active wetting agent which is more effective, thereby 0 obtaining a balance in antiseptic and detergent properties by the use of two or more active wetting agents which differ somewhat from each other in their properties, or one of which, though more effective, is more expensive, and can be 5 advantageously used in smaller amounts together with one or more other active wetting agents.

It will be understood that, where a mixture or plurality of active wetting agents is used, the alkali salt, or mixture of alkali salts used to give 7 to the solution the high pH value, can be varied, and a single salt, or a mixture of salts, used, in such proportions as will insure in the resulting solution the desired high pH value.

By the term wetting agents we. mean those Plate counts 5 wetting agents which are sulfonated products such as sulfonated hydrocarbons or sulfonatedhigher alcohols, and which are free from carboxyl groups, whether free or neutralized, or which have carboxyl groups blanked or made ineffective in a suitable manner, as by substituting for the hydrogen of the carboxyl group an alkyl group, or an amido group, or other suitable group and which do not form objectionable precipitates with calcium and magnesium ions found in hard water, as distinguished from ordinary soaps, which are neutralized carboxylic acids and which form objectionable precipitates with calcium and magnesium ions present in hard water.

We claim: e

1. A germicidal detergent composition comprising a sulfonated alcohol wetting agent and alkaline salts in such proportions that an aqueous solution containing from to 3% of the composition will have a pH value in excess of about 11.5 and will contain a small fraction of 1% of the sulfonated alcohol.

2. A germicidal detergent composition comprising sodium lauryl sulfate and alkaline salts in such proportion that an aqueous solution containing from /2 to 3% of the composition will contain a small fraction of 1% of the sodium lauryl sulfate and will have a pH value in excess of about 11.5.

' 3. A germicidal detergent composition containing a major proportion of 'bufier salts and containing a-relatively small proportion of a mixture of active sulfonated wetting agents, including a sulfonated alcohol wetting agent, said composition being adapted when dissolved in water in amounts ranging from /2 to 3% to form a gel icidal detergent solution'containing a small if n of 1% of the wetting agents with a sufllcient amount of the alkaline salts to give a pH value in excess of about 11.5.