US2692862A - Cleansing compositions having antibacterial properties - Google Patents

Description

Patented Oct. 26, 1954 ITION S HAVING ANTI- PROPERTIES Paul Lipsitz, Forest Brook Glen, DeL, assignor to E. I. du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware N Drawing. Application September 5, 1951,

, Serial No. 245,263

CLEANSING COMPOS BACTERIAL 4 Claims.

This invention relates to improved cleansing compositions, such as soap or synthetic detergents, characterized by possessing anti-bacterial properties. It is an object of this invention to provide cleansing compositions of the aforesaid types which are adapted for use both for laundry and toilet purposes and which possess the quality of inhibiting bacterial growth without being irritating to the skin. Further objects and achievements of this invention will appear as the description proceeds.

While organic detergents such as soap and the so-called synthetic detergents are capable of washing large quantities of bacteria and other micro-organisms off surfaces, relatively appreciable numbers of such organisms are left on the surface which continue to multiply. In order to remove these it is usually necessary to use a separate treatment with an anti-bacterial agent or disinfectant. A combined single step procedure would be highly desirable. However, the problem is not easy to solve on a commercial scale in an economical manner inasmuch as soap destroys the bactericidal efiicacy of nearly all disinfectants. In order to be of universal application the bacteriostat must not lose its activity in the pres ence of soaps or synthetic detergents, it should be active at low concentrations, it should be nontoxic to animals and non-irritating to the skin and preferably should have some afiinity for the skin and other surfaces so that after rinsing, a small amount will remain and exert a bacteriostatic effect.

Heretofore, several additives for soap have been proposed as bactericides such as sulfur, mercury compounds, phenols, chlorinated phenols, etc. With some of these, high proportions of agent to soap are required to give the desired effect. Some of the compounds cause irritation to the skin. Others are toxic and present a hazard in use. Still others show no retention on the skin after rinsing, and the cost of the more efiective ones is often so high as to restrict their use.

Now, according to my invention, disinfectant soaps and synthetic detergents of high anti-bacterial activity, of good retentivity on the skin, and being non-toxic and non-irritating to the skin, may be obtained by incorporating into cleansing compositions of the aforementioned types an agent of the formula:

wherein R1 and R2 are the same or different alkyl radicals having not more than a 2 C-atoms each, while N=Z is a radical of the group obtained by removing 1 N-attached I-I-atom from ammonia, a primary or secondary alkyl amine, morpholine and piperidine, the alkyl radicals in the said alkyl amine containing not more than 4. C-atoms each. Following usage in the literature, the above compounds may be designated as alkyl derivatives of thiocarbamo-sulfenamides. They may be obtained by reacting an alkali metal salt of a dialkyl dithiocarbamic acid with the appropriate amine corresponding to the formula HN=Z, as above defined, in the presence of an oxidizing agent for instance iodine or sodium hypochlorite.

It is remarkable that the above compounds exert bacteriostatic properties in the presence of high concentrations of soap, considering that many related compounds which are known to possess anti-microbial activity in the absence of soap, fail when admixed with the latter. At the same time, the agents of this invention have the additional quality of being retained on the skin after the soap has been rinsed off, thereby continuing their bacteria-inhibiting activity for considerable periods after their application.

The recommended concentrations of the bacteriostatic agent, for the purpose of this invention, are from 0.5 to 5.0% by weight based on the Weight of the cleansing composition. They may be incorporated into the cleansing composition at any convenient stage during the manufacture of the latter. For instance, they may be added as a solid or as a finely-divided suspension in water or as a solution in a suitable solvent, for example alcohol. In the case of soaps, they may be added in the crutcher or in the plodder, if desired, when bar soaps are made. In the case of built soaps and synthetic detergents, which are spray dried, they may be added along with the builders (inorganic salts, carboxymethyl cellulose, etc.) immediately before spray drying. It is only necessary that the anti-bacterial agent be dispersed completely and uniformly throughout the product.

The efi'ectiveness of the resulting product may be tested by standard or special tests, for instance, as follows: i

1. Test for dcti'uity.This is determined by preparing a standard soap solution containing a standard, but small, concentration of the agent. Paper discs impregnated with the above: solution are placed on an agar-agar coated surface containing Staphylococcus aureus, and the activity is gauged by the area of inhibited growth observed after incubating for 24 hours.

2. Test for skin retentivity.-Pieces of untanned calf-skin are treated with the test solution described above and then (1) rinsed, (2) rinsed and washed, or (3) rinsed, washed and scoured withsoap. Thesepieces are then placed on an agar-agar coated surface containing Staphylococcus aureas and observed after 24. hours of incubation. The area of inhibited growth around each piece affords a qualitative measure of the retentivity of bacteriostatic agent by the skin after each of the mentioned degrees of cleansing treatment.

Without limiting this invention, the following list of compounds is given as typical of the agents which may be used according tomy invention.

3. NT,N-dimethyl-N ',N'-diethyl-thiocarbamo-sulfenamide,

(CH3) zN(]%-SN C 2H5) 2 s 4. N,Ndiethyl-thiocarbamo-sulfenamide,

c2115) ewe-satin 5. The compound obtained by condensing, by the aid of iodine, N,N-dimethyl-dithiocarbamic acid and piperidine:

CH2CH2 6. The compound obtained by condensing, by the aid of iodine, N,N-dimethyl-dithiocarbamic acid and morpholine:

CH2CH2 '7. N,N,N',N tetraethyl thiocarbamo sulfenamide,

9. N,N-dim ethyl- N ,N -diisopropyl-thiocarbamosulfenamide,

U. S. P. 2,045,888,1Exam'ple 6. But, 'for the sake. of better clearness, the following "examples are" given to illustrate the method of synthesis.

A. 9.4 parts (0.05 mole) of sodium dimethyldithiocarbamate was dissolved in parts of water and both this solution and 75 parts of a 5.25% solution of sodium hypochlorite dropped, with agitation, into 150 parts of concentrated aqueous ammonia. The temperature of theammonia was held at 010 C. and when the addition was complete, the white precipitate was filtered ofi, washed with cold water, and dried. Its melting point was found to be at 69-70 C.

B. 4 parts (0.0213 mole) of sodium dimethyl dithiocarbamate was dissolved in 17 parts of water and was addedto 35.2 parts of a 25% solution of dimethylamine. The mixture was kept at 20-25" C. and an iodine solution in aqueous potassium iodide was added dropwise with stirring overa period of 2 hours. Stirring was continued for 1 hours, and the precipitate was filtered, washed with water and dried. After recrystallization from petroleum ether, the white product melted at 48-51 C.

The above compounds were tested by me in compositions typified by the following examples, with results as indicated.

Eacample 1.-Soap bar parts of soap powder (Ivory Snow) and 2 parts of N,N-dimethyl thiocarbamo-sulfenamide were pulverized through a micromill, mixed thoroughly and the mixture pressed into molds at 7500 p. s. i.

Tests made with a solution of the above composition containing 1 gram of the soap in 100 cc. of water showed excellent activity and re-, markably high retentivity.

Example 2.Am'onic detergents 1 gram of a sodium alkyl-benzener-sulfonate detergent containing in the alkyl radical an average of about 12 C-atoms was dissolved in 100 cc. of water, and then .020 grams of N,N,N',N'-tetramethyl thiocarbamosulfenamide were added.

Example 3.-Nonionic detergents The detergent in this case was a mixture of compounds obtained by condensing a long-chain alcohol with an average of 16 to 18 moles of ethylene oxide. 100 grams of a 1% solution of this detergent water were treatedwithZ grams of the agent named in Example 2.

Example 4.C'ationic detergents It will be clear that my invention provides.

novel cleansingcompositions of great practical;

and economic value. They may be used in all instances where separate steps of'washing and then disinfecting have been used heretofore.

Thus, the laundering of hospital supplies, the

cleaning of hospital floors and walls, the cleaning of dairies including the barns and the milk-proo essing buidings, the washing of bottles which are to contain foodstuffs, the washing of dishes in restaurants and hotels, the cleaning of oflice buildings, the cleaning oflavatories in public buildings and a myriad of similar applications are carried out with simultaneous disinfection thereof. Also, disinfection can be accomplished simultaneously with washing where it normally is not done because of the necessity for a separate treatment such as in toilet soap for personal use, the home laundry, home cleaning and scrubbing, etc. It is also useful for physicians, nurses, and veterinaries in that washing the hands simultaneously disinfects them and leaves a bacteriostatic residue retained on the skin.

Many other variations in the details of this invention will be readily apparent to those skilled in the art.

I claim as my invention:

1. A cleansing composition comprising soap and an anti-bacterial agent represented by the formula:

/N-(|JSN=Z R2 wherein R1 and R2 are alkyl radicals of not over 2 C-atoms each, while N=Z represents a radical of the group obtained by removing one N-attached H-atom from ammonia, primary and secondary alkyl amines having not more than 4 C-atoms in each alkyl radical, morpholine and piperidine.

2. A cleansing composition as in claim 1, the anti-bacterial agent being present in the propor tion of 0.5 to 5.0% by Weight based on the Weight of the cleansing composition.

3. A cleansing composition as in claim 1, the anti-bacterial agent being N,N-dimethyl-thiocarbamo-sulfenamide.

4. A bacteriostatic cleansing composition comprising soap and N,N-dimethyl-thiocarbamosulfenamide, the proportion of the latter being from 0.5 to 5.0% by Weight of the entire composition.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Re. 22,750 Tisdale et a1 Apr. 30, 1946 2,353,735 Kunz et al July 18, 1944

Claims (1)

1. A CLEANSING COMPOSITION COMPRISING SOAP AND AN ANTI-BACTERIAL AGENT REPRESENTED BY THE FORMULA: