US2360269A - Germicidal compositions - Google Patents

Description

Patented Oct. 10, 1944 GERMICIDAL COMPOSITIONS Alexander M. Partansky,

Midland, Mich., assignor to The Dow Chemical Company, Midland, lVlich., a corporation of Michigan No Drawing. Application February 19, 1942, Serial No. 431,496

12 Claims.

This invention is concerned with new germicidal compositions and is particularly directed to mixtures comprising water-soluble phenolates, and certain alkali metalphosphates.

The water-soluble phenolates are well-known as germicidal toxicants and have found wide ap-- plication in such use. These compounds are employed in dispersions, solutions, emulsions, and powders, adapted to be diluted with, or dissolved in, water or other solvent to produce germicidal, bactericidal, and antiseptic compositions.

The phenolates as a class have a tendency to break down on contact with water to liberate free phenols which may be water-insoluble, less toxic to micro-organisms, and more irritating to humans than the salts themselves. To prevent such dissociation, it is common practice to maintain an appreciable excess of alkali or alkaline reacting salt in compositions comprising the phenolates. Alkaline detergent salts are preferred modifying agents for phenolates. especially in germicidal cleansing powders, washing compositions, and the like. A disadvantage accruing to the use of most detergents resides in the fact that in such mixtures the germicidal effectiveness and phenol coefiicient of the phenolate are reduced.

The present invention provides an improved germicidal composition comprising a watersoluble phenolate as an active toxic ingredient, and a phosphate selected from the group consisting of alkali metal hexametaphosphates, a1- kali metal tetrametaphosphates, and alkali metal tetraphosphates. The toxicity of the phenolate in water solutions of such compositions measured in terms of phenol coefficient is much higher than that accruing to unmodified phenolate solutions or to solutions of phenolate in mixture with many other alkaline detergent salts. A further embodiment of the invention resides in phosphate-phenolate mixtures modified with certain preferred wetting and detergent agents.

All of the phosphates with which the present invention is concerned are characterized as being producible by the dehydration of alkali metal dihydrogen-ortho-phosphate and/or alkali metal mono hydrogen ortho phosphate. Equations for the preparation of representative phosphates of this group are as follows:

4KH2PO4--4H20- (ICPOa) 4 Potassium tetrametaphosphate 6NaH2PO4--6H2O- (NaPOs) 5 Sodium hexametapliosphate 2NaH2PO4+2Na2I-IPO4-3H2O- NasP4O13 Sodium tetrapliospliate In preparing the new compositions the watersoluble phenolate and phosphate are ground or mixed together in any suitable fashion with or without the inclusion of such wetting, dispersing, and detergent agents as further increase the efficiency of the phenolate in the mixture. Sodium hydroxide or other suitable caustic alkali may be included where necessary to stabilize aqueous solutions of the phenolate-phosphate mixture, particularly at higher concentrations, and prevent the precipitation of free phenol. The amount of alkali varies with the particular phosphate and phenolate used, the percentage composition of the mixture and the presence or absence of wetting, dispersing, or other addition agents. This amount increases somewhat with the ratio of phosphate to phenolate, but not proportionately. Thus, in a mixture comprising equal parts by weight of sodium hexametaphosphate and phenolate, 0.1 part by weight of caustic alkali may be required, while in a mixture containing 10 parts by weight of the phosphate per part of phenolate, 0.5 part of alkali may be sufiicient. In any event, sufficient alkali may be employed that when the composition is dispersed in water no precipitation of free phenol results The alkali metal tetrameta-, hexameta-, and tetraphosphates are compatible in any practical proportions with the water-soluble phenolates. Although aqueous solutions of these phosphates alone exert no appreciable germicidal action, compounding the water-soluble phenolates therewith in accordance with the present invention gives compositions which in aqueous solution exhibit apparent phenol coefficients on the basis of solid phenolate which are appreciably in excess of those characterizing the unmodified phenolate.

The preferred weight ratio of phosphate to phenolate varies somewhat with the exact materials employed. Compositions comprising sodium ortho-phenyl-phenolate and the sodium and potassium phosphates constitute a preferred embodiment of the invention and the preferred proportions peculiar thereto are representative. In these mixtures, 1 part by weight of phenolate is generally mixed with from 0.33 to 49 parts of the phosphate. Compositions of optimum utility are those in which 1 part by weight of phenolate is mixed with from 0.5 to 6 parts of the phosphate. In addition, from 0.5 to 3 parts of a wetting agent such as sodium lauryl sulfate may be mixed with each part of phenolate.

The method for determining the phenol coefficients as set forth in the following examples is one developed by the United States Public Health Service Hygienic Laboratory and described in Circular 198 of the Food and Drug Administration of the United States Department of Agriculture. The phenol coefi'icients, as hereinafter set forth, are based upon a coefficient of 1.0 for pure phenol. The phenol coefiicientof ortho-phenylphenol as the sodium salt according Ph 1 em to this method is 16-17. wemcient of The following examples are not to be construed Bodegas: as limiting either with respect to the proportions Composition oi test mixture employed or the particular materials disclosed. 6 g eggi z'y ii at EXAMPLE 1 g!) Finely ground sodium ortho-phenyl-phenolate was mixed with various proportions of sodium sodignigrgfiho-phenfihgnoleugoss my OH 210 '1 parts a an par l a hexamet aphosphate, sodium tetrametaphosphate, 10 wimlpm (NaPonjgnd 004 DMNBOH no and sodium tetraphosphate to obtain dry, white g g; foparts's (I 3PPO(;))3andd0602 par: 18 1 par a 3 811 DB! 8- H... powders containing from approximately 4 to 00 wnmparts abmouand (m4 20.0 per cent by weight of the phenolate. In certain 311% 51013811: h m o aand og ar fiaggflm it 8T5 B 511 par 8 in t s m ll am s f s dm hy xi e w r sodium i g gg (mp0s), n 0 incorporated in the mixtures. These composisodium tetrametaphosphatc(NaPOz)4.. 0.0 tions were dissolved in water to obtain detergent sdmm tetaplmphae Nmmo" and germicidal solutions useful for the sterilization of drinking glasses, dishes, and silverware. The Preferred mixtures as musftrated m the Analogous series of mixtures were prepared in foregfltng table may further e o l d to imp which tri-sodium phosphate, sodium carbonate, 20 even higher phenol wefliclel'lt's t0 e Phenolate and other alkaline reacting salts were substituted Contalned therein by h add-1131011 0f certflln typ for the preferred phosphates. The following table of detergent and wetting agents. The preferred sets forth the comparative efficiencies of the 50- group of addltlon agents are the Water-soluble i orthmphenypphenolate m the mixtures salts of the alkyl-aryl-sulfonates, higher fatty Table A 5 alcohol sulfonates, and alkyl-phenylphenol sulfonic acids. The addition of wetting and detergent agents generally to the phosphate mixtures Phenol does not cause an increase in the apparent pH 235 of of the phenolate, nor does the addition of the 30 preferred wetting and dispersing agents to phe- Commsition of test mixture g r nolate mixtures with common alkaline reacting 5.5.32. salts other than the preferred phosphates opervpg ate to the benefit of the ultimate composition. It is believed that the chemical constitution of the modified mixtures as hereinafter set forth is crit- Sodmm ortbo-phenyl-phenolate: 30 1 al 11.0 E 2 i part a: a. 9.5 XAMPLE With 3 parts NmCOa 5. 5 \Yith 5 parts N 1co= 7.2 ng 10 partIsqIYa 8O fi.6 8.3 Mixtures of sodium ortho-phenyl-phenolate it ggg d-. f 2 g 40 with sodium hexametaphosphate, sodium tetraggm 5pa1'ts I\;\3PO().12 1120.- 1.1 metaphosphate and sodium tetraphosphate were 31 ;g g gg ground with sodium alkyl-aryl-sulfonates (marxlitggparts Blgrax and 1.2 parts NaOlEl. 1010 keted as Santomerse #1 and Naccanol NR), and 3g 8g gy gegge gg sodium lauryl-sulfate (variously sold as Orvus, gz'itggparts 1125158 e 45 Brett, and Grasselli IN-18l-P). The following a gggg g d 5 table sets forth the composition of the several git 2; parts 81 383). ring 0.08 part N on" 21,0 mixtures and of certain control compositions, and 5 220: Estate... trainee-.1... as the apparent Phenol coefficients of the phenolate With 10 parts (N aPOa). and 0.26 part NaOEL. 22.0 emp y d therein- Table B Phenol co- Parts by eigi cient of weight of P t f sodium'or' Phosphate Parts of Wetting and dispersing agt. w tt g e or tho'phenyl mo.pheny1 D1105- agent I\aOH phenolate phenolate phate against E. iuphiz at 20 0.

0 Sodium lauryl sulfate. 0. 5 22 0 .d0 1.0 24 0 2.0 22 0 4.0 24 0 0.0 24 3 0.5 20 a 0.5 21 0.5 1.0 31 1.0 1.0 0.0 1.0 31 0.5 2.0 a0 1.0 2.0 10.0 2.0 as 3.0 3.0 35 4.3 35 2. 33 Na? 0:); 6. 0 3. 0 33 BsPuOn 2. 0 2.0 34 NaP4O1; 6.0 d0 3.0 0 Sodium alkyl'eryl-sull'onate (Santomerse #1). 3.0 20 (NQPOQQ 6.0 0 3.0 30 (NaPOzh 6.0 Alkyl-aryl-sullonate (Santomerse #1). 3.0 31 NPQPOIZ 6.0 0 3.0 23 (NaPOz). 6.0 Sodium alkyl-aryl-sulfonate (N accanol 3. 0 28 EXAMPLE 3 Sodium 2-phenyl-monochloro-phenolate was mixed with a number of alkaline salts and the preferred phosphate compounds substantially as described in Example 1. The following table illustrates the results obtained with representative compositions.

Table C Phenol coefiicient of Composition of test mixture 523321 2 typhieat 20 Sodium 2-phenyl-monochlorophenolate:

Alone 85 Vi 1th 10 parts NmCOL 19 With 10 parts N8aPO4. 18 With 10 parts (NaPOm 130 With 10 parts (NaPOz); and 0.4 part NaOH 120 A modified composition was prepared in which one part by weight of the sodium Z-phenyl-monochloro-phenolate, 10 parts of sodium tetrametaphosphate, 10 parts of sodium lauryl sulfate, and 0.4 part of sodium hydroxide were ground together. In this composition the phenolate had an apparent phenol coefficient of 135 against E. typhii at 20 C.

EXAMPLE 4 In a similar manner sodium monochlorocarvacrolate was compounded with representative phosphates and other alkaline salts. In these compositions the sodium monochloro-carvacrolate had the apparent phenol coefficients set forth in the following table.

Any of the other water-soluble salts of the phenols disclosed or the sodium, potassium, lithium, calcium, barium, ammonium, or magnesium salts of such other phenols as carvacrol, thymol, parachloro-thymol, 4-hexyl resorcinol, 2-chloro-4-phenyl-phenol, 2.4.5-trichlorophenol, 2.4.6-trichlorophenol, 2.4.5.6 tetrachlorophenol, pentachlorophenol, 2 chloro 4 tertiaryamylphenol, 4-chloro-symmetrical-Xy1enol or mixtures of such water-soluble phenolates may be employed in place of those compounds shown in the examples. Also potassium hexametaphosphate, potassium tetrametaphosphate, potassium tetraphosphate or mixed sodium and potassium compounds may be substituted for the sodium derivatives shown in the examples. It is also sometimes advantageous to employ combinations of two or more of the wetting and detergent agents as set forth above. In place of the sodium hydroxide shown in certain of the compositions, potassium hydroxide or other suitable alkali metal hydroxides or oxides may be substituted.

I claim:

1. A germicidal composition comprising a water-soluble phenolate and a phosphate selected from the group consisting of the alkali metal hexametaphosphates, tetrametaphosphates, and tetraphosphates, as the sole inorganic alkaline salt constituent.

2. A germicidal composition comprising a water-soluble phenolate, a phosphate selected from the group consisting of the alkali metal hexametaphosphates, tetrametaphosphates, and tetraphosphates, as the sole inorganic alkaline salt constituent, and suificient caustic alkali that when the composition is dissolved in water free phenol is not precipitated from solution.

3. A germicidal composition comprising a sodium phenolate and a phosphate selected from the group consisting of the alkali metal hexametaphosphates, tetrametaphosphates, and tetraphosphates, as the sole inorganic alkaline salt constituent.

4. A germicidal composition comprising sodium orthophenyl-phenolate and a phosphate selected from the group consisting of the alkali metal hexametaphosphates, tetraphosphates, and tetraphosphates, as the sole inorganic alkaline salt constituent.

5. A germicidal composition comprising a water-soluble phenolate and an alkali metal hexametaphosphate, as the sole inorganic alkaline salt constituent.

6. A germicidal composition comprising a water-soluble phenolate and an alkali metal tetrametaphosphate, as the sole inorganic alkaline salt constituent.

7. A germicidal composition comprising a water-soluble phenolate and an alkali metal tetraphosphate, as the sole inorganic alkaline salt constituent.

8. A germicidal composition comprising a water-soluble phenolate and from 0.33 to 49 parts by weight of a phosphate selected from the group consisting of the alkaline metal hexametaphosphates, tetrametaphosphates, and tetraphosphates, as the sole inorganic alkaline salt constituent.

9. A germicidal composition comprising sodium orthophenyl-phenolate and from 0.5 to 6 parts by weight of a phosphate selected from the group consisting of the alkali metal hexametaphosphates, tetrametaphosphates, and tetraphosphates, as the sole inorganic alkaline salt constituent.

10. A germicidal composition comprising a water-soluble phenolate, from 0.33 to 49 parts by weight of a phosphate selected from the group consisting of the alkali metal hexametaphosphates, tetrametaphosphates, and tetraphosphates, as the sole inorganic alkaline salt constituent, and a wetting and detergent agent selected from the group consisting of water-soluble salts of alkyl-aryl-sulphonates, higher fatty alcohol sulphates, and alkyl-phenyl-phenol suli'onic acids.

11. A germicidal composition comprising a water-soluble phenolate, sodium lauryl sulfate, and a phosphate selected from the group consisting of the alkali metal hexametaphosphates, tetrametaphosphates, and tetraphosphates, as the sole inorganic alkaline salt constituent.

12. A germicidal composition comprising sodium orthophenyl-phenolate, sodium lauryl sulfate, and sodium hexametaphosphate, as the sole inorganic alkaline salt constituent.

ALEXANDER M. PARTANSKY.