GB1583765A - Liquid disinfectant - Google Patents

Description

(54) LIQUID DISINFECTANT (71) We, COLGATE-PALMOLIVE COM- PANY, a Corporation organised under the laws of the State of Delaware, United States of America, of 300 Park Avenue, New York, New York 10022, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a liquid disinfectant; more particularly to a liquid disinfectant composition that exhibits a substantially stable single phase over a wide range of temperatures while at the same time having a relatively high phenol coefficient, i.e. greater than 3, preferably greater than 5. Phenol coefficient as used herein is the value derived from the method employed in determining the phenol coefficients developed by the United States Public Health Service Hygienic Laboratory, United States Department of Agriculture. These values are based upon a coefficient of 1.0 for pure phenol.

The compositions of the present invention exhibit a good "shock" emulsion when poured into water. That term, as used herein, means the immediate formation of an emulsion when the composition is poured into water.

Phenols, such as those that are non-halogenated as well as those that are halogenated, such as, dichloro-m-xylenol, are known to possess an effective germicidal activity against Gram negative bacteria such as the organism Salmonella typhi. In order to make practical use of its germicidal effect, however, it is necessary to ensure that when the dichloro-m-xylenol is brought into contact with the organisms to be killed it is in the form of an aqueous solution or dispersion. Like many other chlorinated phenols, however, dichloro-m-xylenol is almost insoluble in water (in fact, it is soluble only to the extent of about I part in 25,000), and in practice it is normally formulated with a stabilizer, particularly with a soap such as caster oil soap. The usual method of formulation is to solubilize dichloro-m-xylenol in a relatively concentrated aqueous solution of castor oil soap or coconut oil soap to ensure that when the composition has been diluted with a large excess of water, as the marketed composition normally will be immediately before use, the dichloro-m-xylenol is maintained as an emulsion.

It is also customary to add an essential oil such as terpineol, and this, in addition to its capacity to confer on the formulation a pleasant odour, often has itself an appreciable solubilizing action on the dichloro-m-xylenol.

Current trends in the compounding of synthetic phenolic germicides have been toward the preparation of liquid water-miscible concentrates adapted to be diluted by the ultimate user to produce aqueous solutions and dispersions of any desired concentration. In these compositions the phenolic material is intimately dispersed or dissolved in materials adapted to act as emulsifying and solubilizing agents therefor upon subsequent dilution with water. A representative composition might comprise orthophenylphenol in mixture with an alkali hydroxide, a soap or synthetic wetting and dispersing agent, and a water-miscible organic solvent, or such combination of two or more of the foregoing as is required to give a liquid germicidal material freely miscible with water.

Conventionally, chlorinated phenol and pine oil disinfectants are solubilized generally by castor oil and red oil soaps. The foregoing soaps are relatively expensive materials that generally provide poor low temperature solubility. On the other hand, when nonionic surfactants are employed as the solubilizer, they tend to deactivate or reduce the germicidal properties of the chlorinated phenols. The foregoing represents a serious deficiency inasmuch as the phenol coefficient should be about 3 or greater in order to provide effective germicidal properties. An alkyl benzene sulphonate anionic surfactant, when employed alone, fails adequately to solubilize the pine oil/chlorinated phenol mixture; while, when a mixture of anionics is employed (e.g. secondary alkyl sulphates), there is satisfactory solubilization but with increased cost of the product. It is known that the minimum surfactant present yields the maximum germicidal properties, i.e. inverse relationship between surfactant and phenol coefficient.

U.S.P. 2,906,664 discloses a dichloromethylxylenol-based disinfectant using soluble salts of dichloromethylxylenol, and hence, there is no need for a solubilizer.

U.S.P. 2,359,241 shows a pine oil based dis infectant incorporating a partially neutralized sulphonated vegetable oil; however, this vegetable oil is probably an unsaturated fatty acid and hence, again there is no need for a solubilizer.

U.S.P. 3,326,808 discloses an antiseptic detergent composition useful as a liquid skin cleaner which contains a disinfectant agent, anionic detergent, a super-fatting agent and a glycol ether having a mild pH. The teaching therein, however, is directed to a detergent formulation for use on the skin and therefore the phenol coefficient is lower than required of a straight disinfectant liquid.

It is nevertheless a fact that dichloro-mxylenol compositions as ordinarily formulated with a soap or anionic detergent suffer from a serious disadvantage, namely their low activity against Gram positive bacteria, for example, Staphylococcus aureus strains, which are largely responsible for blood infections. While castor oil soap enhances the activity of dichloro-mxylenol against Gram negative bacteria, so that as the proportion of soap in an aqueous composition containing a given quantity of dichlorm-xylenol is increased so the germicidal activity of the composition against these organisms is increased (at least within ordinary limits), tests have shown that castor oil soap exerts exactly the opposite effect on the activity of dichlorom-xylenol compositions against Staphylococcus aureus. This phenomenon may possibly be due to the fundamental differences in the cell wall structures of Gram negative and Gram positive bacteria, but whatever the reason, it is found in practice that in order to prepare from dichlorom-xylenol a germicidal composition having a usefully high degree of activity against such organisms as Salmonella typhi, there has to be used such a high proportion of soap that the activity of the composition against Gram positive organisms such as Staphylococcus aureus is reduced to an undesirably low value.

Such an ill-balanced germicidal activity against different types of organism, which may well be present together on a surface required to be disinfected, can be a practical disadvantage of considerable importance.

According to the present invention a liquid disinfectant composition comprises by weight, (a) from 1% to 10% of a phenolic compound having germicidal properties (b) pine oil, (c) a water-soluble C12 to C20 olefin sulphonate or C12 to C20 alkyl sulphonate and (d) water, the ratio of (b) to (a) and (c) to (a) being from 0.5 : 1 to 4 : which composition has a phenol coefficient (as defined above) of at least 3, preferably at least 5.

The composition may also contain up to 30% (e.g. from 1% to 30%) of a lower alkanol, particularly when the sulphonate is present in amount between 1% and 5%.

Abrasivity may be provided to the liquid disinfectant composition by including therein from 5% to 15%, preferably about 10% of an abrasive such as calcite, amorphous or crystalline silica or clays such as feldspar and the like.

By including in the phenol-containing compositions the pine oil and the sulphonate as set forth above, improved compositions are obtained which have the desirable properties of the known mixtures as regards stability and in which the activity of the phenolic constituent (as measured in terms of phenol coefficient against Staphylococcus aureus) is significantly improved over that which might be expected.

The amount of pine oil which is incorporated in such compositions is generally between about 1 and 4 parts per part by weight of the phenolic material in the composition. In mixtures of these proportions, the apparent phenol coefficient of the phenolic material is appreciably in excess of that of phenol in unmodified compositions.

The foregoing is exhibited despite the fact that a germicidal phenolic material is added to an aqueous solution of an anionic surface active agent in order to solubilize the phenolic material and so to facilitate its access to the bacterial cell wall and hence its germicidal action against the bacteria. When abrasive is employed, it is added after the phenolic material is solubilized in the anionic surface active agent.

Typically the components are contacted at about 10"-50 "C with stirring.

The preferred proportion of pine oil varies with the particular sulphonate and amount thereof employed in the composition, but substantial excesses of sulphonate detergent and pine oil are to be avoided if compositions of high efficacy are desired.

In the development of the present invention it has been found that a particularly improved result is obtained with compositions including dichlorometaxylenol, although other phenols such as orthophenylphenol, monochloroorthophenylphenol, monochloroparaphenylphen ol and orthobenzylparachlorophenol are useful.

While mixtures of these phenols with pine oil have a somewhat increased effectiveness against S.-typhi, their effectiveness against the more difficultly-controlled Staphylococcus organisms does not appear to be affected.

The amount of phenolic compound which is incorporated in the formulated germicidal composition will depend on the type of composition it is desired to produce, and when preparing an aqueous germicidal solution, for example of the type intended for household use, an amount of the phenolic material sufficient to give a concentration of from 1 to 10%, typically about I to 5% w./v., will in general be found satisfactory. However, if it is desired to prepare a highly concentrated composition, say in the form of a viscous liquid or a paste comprising the phenolic material and surface-active agent, which can be economically transported and subsequently diluted with water to form an aqueous germicidal composition, then considerably more than 5% w./v., can be employed.

It has also been found to be advantageous to employ a lower alkanol (Cl 6) in the composition, for example, about 1 to 30% by weight, preferably about 5 to 20%.

The anionic sulphonate preferably has an alkyl or alkanyl chain length of 14 to 17 carbon atoms, and then sulphonate as anionic detergent is preferably employed in amounts of 3 to 10%.

Operative sulphonates falling within the abovementioned class include long-chain alkene sulphonates, longchain hydroxyalkane sulphonates. Other examples of sulphonate detergents are paraffin sulphonates containing about 12 to 20 carbon atoms having the sulphonated group distributed along the paraffin chain as shown in U.S. Patents 2,503,280; 2,507,088; 3,260,188; and German Patent 735,096.

As has already been mentioned, it is very desirable that a germicidal composition should have a balanced activity; that is to say its germicidal activity against each type of organism (gram positive or gram negative) should be roughly of the same order, and the invention provides compositions having a usefully high activity against both types. In practice a compromise will usually be sought by adjusting the proportion of sulphonate to phenolic compound so that the resulting composition is stable and possesses maximum activity against both types of organisms mentioned. Again it is a fairly simple matter to determine what minimum level of sulphonate to use in order to achieve this result, and very satisfactory compositions have, for example, been obtained using the sulphonate and the phenolic compound in the proportion of about 1:1 to 4 1 and particularly about 2 : 1 by weight.

A quantity of pine oil amounting from about 2% to 8% w./v preferably about 5% w./v of the aqueous composition has been found to give very satisfactory results.

The compositions of the present invention may be packaged in any suitable container, such as, for example, a flexible plastic tear open envelope having metered amounts therein, a capped rigid pourable container, an aerosol, pump etc.

In operating according to the invention, it is sufficient to add the required amount of phenol to a mixture of pine oil and alkanol with stirring. The foregoing mixture is then added to the sulphonate. In an alternative procedure, the phenol may be dissolved in the pine oil. The exact method of compounding is not critical, provided only that there be formed a homogeneous liquid concentrate which, on dilution with water, has a milky appearance.

The following Examples are offered by way of illustration and are not to be considered as limiting the scope of the invention. All parts, percentages and proportions therein as well as in the appended claims are by weight unless otherwise indicated.

EXAMPLE I The following product is prepared following the making procedure as outlined above.

PARTS Dichlorometaxylenol (DCMX) 2.0 Pine Oil 5.0 Isopropanol 12.0 *Hostapon SAS 60 7.0 Water q.s to 100.0 This is made by dissolving the DCMX in a mixture of the pine oil and isopropanol and adding this to an aqueous solution of the paraffin sulphonate.

* Cl4 l7 n-Alkane Sulphonate - 60% A.l.

(Hoechst) (Hostapon is a Trade Mark) EXAMPLES 2-5 The procedure of Example 1 is repeated except that monochloroorthoxylenol, orthophenylphenol, monochloroparaphenylphenol and orthobenzyl parachlorophenol are substituted for the dichlorometaxylenol, respectively.

EXAMPLES 6-11 The procedure of Examples 2-5 is repeated except that the amounts of the respective phenols is decreased to 1 part and increased to 3 parts respectively.

EXAMPLES 12-13 The procedure of Example 1 is repeated except that a C12 to 16 and C15 to 17 n-alkane sulphonate is substituted for that of Example 1, respectively.

EXAMPLES 14-15 The procedure of Examples 12-13 is repeated except that the amount of sulphonate used is 6 parts rather than 4.2 parts, respectively.

EXAMPLES 16-17 The procedure of Example 1 is repeated except that the alcohol is ethanol or butanol, respectively, and the amounts thereof are decreased to 8 parts and increased to 16 parts respectively.

EXAMPLES 18-19 The procedure of Example 1 is repeated except that a C14 to 16 olefin sulphonate is employed in place of the paraffin sulphonate, in amounts of 5% and 6%, respectively.

EXAMPLE 20 The procedure of Example 1 is modified to provide an abrasive disinfectant composition of calcite after the DCMX is solubilized in the paraffin sulphonate. The composition is as follows: PARTS DCMX 2 Pine Oil 5 Calcite 10 Hostapon SAS 60 10 Water q.s. to 100 All of the foregoing formulations will exhibit good "shock" emulsion properties as well as low temperature stability as well as having a phenol coefficient greater than about 3.

Claims (16)

WHAT WE CLAIM IS:

1. A single phase disinfectant composition comprising, by weight (a) from 1% to 10% of a phenolic compound having germicidal properties (b) pine oil (c) a watemsoluble C12 to C20 olefin sulphonate or C12 to C20 alkyl sulphonate and (d) water, the ratio of (b) to (a) and (c) to (a) being from 0.5:1 to4 : 1,whichcom- position has a phenol coefficient (as hereinbefore defined) of at least 3.

2. A composition as claimed in Claim 1 comprising 1 to 30Sto of sulphonate (c).

3. A composition as claimed in claim 1 or claim 2 wherein from 1% to 30% of a lower alkanol is present.

4. A composition as claimed in any of claims 1 to 3 wherein from 5% to 15% of an abrasive is present.

5. A composition as claimed in claim 4 wherein the abrasive is calcite.

6. A composition as claimed in any of the preceding claims wherein component (a) is a halogenated phenol.

7. A composition as claimed in claim 6 wherein the halogenated phenol is a chlorinated phenol.

8. A composition as claimed in claim 7 wherein the chlorinated phenol is dichlorometaxylenol.

9. A composition as claimed in any of the preceding claims wherein component (c) is a C12 to C20 paraffin sulphonate.

10. A composition as claimed in any of the preceding claims having a phenol coefficient greater than 5.

11. A composition as claimed in any of the preceding claims having a pH in the range from 6 to 10.

12. A single phase liquid disinfectant composition substantially as described in the Examples.

13. A method of making the composition claimed in any of the preceding claims comprising forming a mixture of components (a) and (b), adding the mixture to component (c) and thereto and thereafter adding the thus formed solution to component (d).

14. A method as claimed in claim 13 carried out at temperatures in the range from 10 to 50 "C, with stirring.

15. A method of making the composition claimed in any of claims 1 to 12 substantially as described in the Examples.

16. A method of disinfecting an article to be treated comprising applying a composition as claimed in any of claims 1 to 12 to the surface of the treated article.