WO2006048104A1

WO2006048104A1 - Insect repellent composition

Info

Publication number: WO2006048104A1
Application number: PCT/EP2005/011014
Authority: WO
Inventors: Chintamani K Lagoo; Suresh Ramamurthi
Original assignee: Unilever N.V.; Unilever Plc; Hindustan Lever Limited
Priority date: 2004-11-01
Filing date: 2005-10-13
Publication date: 2006-05-11
Also published as: AR051752A1

Abstract

The invention provides aqueous compositions comprising a surfactant, a chlorine-based disinfecting compound and an insect repellent compound selected from diphenylmethane, beta-naphthol methyl ether, naphthalene or benzophenone.

Description

Insect Repellent Composition

Technical Field

The invention relates to insect-repellent compositions and in particular to cleaning compositions that provide insect repellency.

Background and Prior art

Insect repellent compositions are used for repelling insects like ants, flies, cockroaches, mosquitoes among others which are crop pests, vectors & carriers of human disease and are also a nuisance. Insect repellent compositions for application on soft surfaces like fabrics and on hard surfaces at home and elsewhere, and application on the skin are also known. Insect repellents are available in a variety of forms. Insect repellent compositions, while repelling insects, must be safe to the people in the area where the composition is applied.

US2897112 (Harford, 1956) describes a pest combating composition suitable for combating houseflies, consisting essentially of a pyrethrin, diphenylmethane and acetophenone in a hydrocarbon distillate fraction, the total amount of pyrethrin being 0.02 to 0.6% by weight of said composition, the ratio of the weight of acetophenone to pyrethrin lying in the range of 5:1 to 15:1 and the ratio of the weight of diphenyl methane to pyrethrin lying in the range of 5:1 to 15:1. This composition essentially requires use of a hydrocarbon distillate fraction which is undesirable as it is both flammable and cost extensive. Diphenyl methane is also a perfumery material which has been used in cleaning compositions e.g WO9612468 (P&G, 1996) describes personal treatment compositions comprising from about 0.001 % to about 10 % of an enduring perfume, from about 0.01 % to about 95 % surfactant system and the balance carrier. In this publication, one of the enduring perfume mentioned is diphenyl methane.

WO00027197 (P&G, 2000) describes an insect repellent composition comprising: a) an insect repellent active blend comprising a fragrance carbonyl compound, a fragrance alcohol, a fragrance ester, a nitrile compound, an epoxide, and an ether compound; and b) a cosmetically-acceptable carrier. One of the carbonyl compounds described therein is benzophenone.

WO9725137 (Surtsey) describes a solid composition intended for use in garbage containers to combat malodours and repel insects, particularly flies. The composition comprises water-isoluble absorbent granules, a hypochlorite compound and optionally an insect repellent chosen from camphor, citronella oil, pine needle oil, naphtalene and citric acid.

Beta naphthol methyl ether also known as yara yara has been widely used as a perfumery molecule and has been incorporated in cleaning and cosmetic compositions. The journal article in Nippon Nogei Kagaku Kaishi (18, 27-34, 1942) reports the insecticidal properties of naphthyl ethers [C10H7OR] where R was varied as H, methyl, ethyl, and phenyl. The article reports that the insecticidal properties of 2-naphthyl methyl ether were good. Naphthalene which is a sublimable solid material has been used for repelling insects.

The present inventors have now determined after extensive experimentation that insect-repellent compounds selected from diphenyl methane, beta naphthol methyl ether, benzophenone and naphthalene in a base comprising water and a surfactant provide for synergistic benefit in repelling insects in the presence of a chlorine based disinfecting compound.

Objects of the invention

It is thus an object of the invention to provide for an insect repellent composition that is highly efficient in repelling insects.

It is another object of the invention to provide for an insect repellent composition that in addition to repelling insects cleans the surface being treated.

It is another object of the invention to provide for an insect repellent composition that in addition to repelling insects disinfects the surface being cleaned against germs.

It is yet another object of the invention to provide for an insect repellent composition that repels insects, disinfects against germs and has a pleasant odour either without the need for addition of further perfumes or can be suitably blended with other perfumery chemicals. Summary of the invention

According to the present invention there is provided an insect repellent composition comprising (a) 0.01 to 90% by weight of an insect repellent selected from diphenyl-methane, beta-naphthol methyl ether, naphthalene or benzophenone,

(b) 0.5 to 25% by weight of a surfactant,

(c) 0.1 to 6% by weight of a chlorine based disinfecting compound

(d) the balance being water

Detailed description of the invention

The invention provides for a cleaning composition which essentially comprises an insect repellent compound selected from the group comprising diphenyl methane, beta naphthol methyl ether, naphthalene, or benzophenone in an aqueous surfactant solution and a chlorine based disinfecting compound .

The insect repellent compound is present in an amount in the range of 0.01 to 90%, preferably 0.1 to 50%, more preferably 0.5 to 25% by weight of the composition.

Particularly preferred insect repellent compounds are: diphenyl-methane, beta-naphthol methyl ether and benzophenone.

The composition comprises a surfactant in an amount in the range of 0.5 to 25%, preferably 1 to 15%, more preferably 2 to 10% by weight of the composition. The surfactant is chosen from any known surfactant e.g. of the anionic, cationic, amphoteric, nonionic or zwitterionic types, but it is preferred that the surfactant is of the anionic or non-ioni.c type.

The anionic surfactant may be soap or non-soap. The term soap denotes salts of carboxylic fatty acids. The soap may be derived from any of the triglycerides conventionally used in soap manufacture - consequently the carboxylate anions in the soap may contain from 8 to 22 carbon atoms. The term total fatty matter, usually abbreviated to TFM is used to denote the percentage by weight of fatty acid and triglyceride residues present in soaps without taking into account the accompanying cations.

For soap having 18 carbon atoms, an accompanying sodium cation will generally amount to about 8% by weight. Other cations may be employed as desired for example zinc, potassium, magnesium, alkyl ammonium and aluminium. -

The soap may be obtained by saponifying a fat and/or a fatty acid. The fats or oils generally used in soap manufacture may be such as tallow, tallow stearines, palm oil, palm stearines, soya bean oil, fish oil, castor oil, rice bran oil, sunflower oil, coconut oil, babassu oil, palm kernel oil, and others. In the above process the fatty acids are derived from oils/fats selected from coconut, rice bran, groundnut, tallow, palm, palm kernel, cotton seed, soyabean, castor etc. The fatty acid soaps can also be synthetically prepared (e.g. by the oxidation of petroleum or by the hydrogenation of carbon monoxide by the Fischer-Tropsch process) . Resin acids, such as those present in tall oil, may be used. Naphthenic acids are also suitable.

Tallow fatty acids can be derived from various animal sources and generally comprise about 1-8% myristic acid, about 21-32% palmitic acid, about 14-31% stearic acid, about 0-4% palmitoleic acid, about 36-50% oleic acid and about 0-5% linoleic acid. A typical distribution is 2.5% myristic acid, 29% palmitic acid, 23% stearic acid, 2% palmitoleic acid, 41.5% oleic acid, and 3% linoleic acid. Other similar mixtures, such as those from palm oil and those derived from various animal tallow and lard are also included.

Coconut oil refers to fatty acid mixtures having an approximate carbon chain length distribution of 8% Cs, 7% Cio, 48% Ci₂, 17% Ci₄, 8% Ci₆, 2% Ci₈, 7% oleic and 2% linoleic acids (the first six fatty acids listed being saturated) . Other sources having similar carbon chain length distributions, such as palm kernel oil and babassu kernel oil, are included within the term coconut oil.

A typical fatty acid blend consists of 5 to 30% coconut fatty acids and 70 to 95% fatty acids ex hardened rrice bran oil. Fatty acids derived from other suitable oils/ffats such as groundnut, soybean, tallow, palm, palm kernel, etc. may also be used in other desired proportions.

A suitable class of anionic surfactants are water-soluble salts of organic sulphuric acid mono-esters and sulphonic acids having in the molecular structure a branched or straight chain alkyl group containing 8-22 C atoms or an alkylaryl group containing 6-20 C atoms in the alkyl part .

Examples of such anionic surfactants are water soluble salts of :

- long chain (i . e . 8-22 C-atom) alcohol sulphates (hereinafter referred to as PAS ) , especially those obtained by sulphating the fatty alcohols produced from tallow or coconut oil or the synthetic alcohols derived from petroleum; alkylbenzene-sulphonates, such as those in which the alkyl group contains from 6 t o 20 carbon atoms ;

- secondary alkanesulphonates . Also suitable are the salts of : - alkylglyceryl ether sulphates , especially of the ethers of fatty alcohols deri ved from tallow and coconut oil; fatty acid monoglyceride sulphates; sulphates of ethoxylated aliphatic alcohols containing 1-12 ethyleneoxy groups ; alkylphenol ethylenoxy-ether sulphates with from 1 to 8 ethyleneoxy units per molecul e and in which the alkyl groups contain from 4 to 14 carbon atoms ;

- the reaction product of fatty acids esterified with isethionic acid and neutralis ed with alkali .

Suitable nonionic detergent active compounds can be broadly described as compounds produced b^~γ the condensation of alkylene oxide groups , which are tiydrophilic in nature, with an organic hydrophobic compound which may be aliphatic or alkyl aromatic in nature . The Hength of the hydrophilic or polyoxyalkylene radical which Λ.s condensed with any particular hydrophobic group can be readily adjusted to yield a water-soluble compound having the desired degree of balance between hydrophilic and hydrophobic elements. Other nonionic surfactants that can be employed include the alkylpolyglucosides.

Particular examples include the condensation product of aliphatic alcohols having from 8 to 22 carbon atoms in either straight or branched chain configuration with ethylene' oxide, such as a coconut oil ethylene oxide condensate having from 2 to 15 moles of ethylene oxide per mole of coconut alcohol; condensates of alkylphenols whose alkyl group contains from 6 to 12 carbon atoms with 5 to 25 moles of ethylene oxide per mole of alkylphenol; condensates of the reaction product of ethylenediamine and propylene oxide with ethylene oxide, the condensate containing from 40 to 80% of polyoxyethylene radicals by weight and having a molecular weight of from 5,000 to 11,000; tertiary amine oxides of structure ¹R₃NO, where one group R is an alkyl group of 8 to 18 carbon atoms and the others are each methyl, ethyl or hydroxyethyl groups, for instance dimethyldodecylamine oxide; tertiary phosphine oxides of structure R₃PO, where one group R is an alkyl group of from 10 to 18 carbon atoms, and the others are each alkyl or hydroxyalkyl groups of 1 to 3 carbon atoms, for instance dimethyldodecylphosphine oxide; and dialkyl sulphoxides of structure R₂SO where the group R is an alkyl group of from 10 to 18 carbon atoms and the other is methyl or ethyl, for instance methyltetradecyl sulphoxide; fatty acid alkylolamides; alkylene oxide condensates of fatty acid alkylolamides and alkyl mercaptans. Further examples of suitable surfactants are compounds commonly used as surface-active agents given in the wel_l- known textbooks: "Surface Active Agents" Vol.l, by Schwartz & Perry, Interscience 1949; "Surface Active Agents" Vol.2 by Schwartz, Perry & Berch, Interscience 1958; the currrent edition of "McCutcheon' s Emulsifiers and Detergents" published by Manufacturing Confectioners Company; "Tenside- Taschenbuch", H. Stache, 2nd Edn., Carl Hauser Verlag, 1981.

Highly preferred surfactants used in the compositions of the invention include amine oxides and sodium lauryl ethoxy sulphates.

The composition of the invention comprises a chlorine based disinfecting compound in the range of 0.1 to 6%, preferably 0.5 to 5% by weight of the composition. The chlorine based disinfecting compound is preferably an alkali metal hypochlorite or an alkaline earth metal hypochlorite . A highly preferred disinfecting compound is sodium hypochlorite. When an alkali metal hypochlorite or an alkaline earth metal hypochlorite is used, it is desirable to maintain the pH above 10, preferably above 11 and iaore preferably above 12. The alkalinity of the composition is obtained by use of any or a combination of the following alkaline materials e.g. sodium hydoxide, alkaline silicate, meta silicate, sodium aluminate or sodium carbonate. It is preferable to have an equivalent free alkalinity of 1% as sodium hydroxide to maintain the suitable high pH. OPTIONAL INGREDIENTS

Optionally abrasives may be present in the composition of the invention. Solvents can optionally be used in the composition of the invention. Suitable solvents include hydrocarbons, ketones, ethers, alcohols and their esters, more preferably tertiary alcohols and their esters.

The composition according to the invention may contain other ingredients that aid in cleaning performance, in addition to providing the insect repellency effect. For example, the composition can contain detergent builders other than the special water-soluble salts such as nitrilotriacetates, polycarboxylates, citrates, dicarboxylic acids, water-soluble phosphates especially polyphosphates, mixtures of ortho- and pyrophosphates, zeolites and mixtures thereof. Such builders can additionally function as abrasives if present in an amount in excess of their solubility in water. In general the builder other than the special water-soluble salts when employed, preferably will form from 0.1 to 25% by weight of the composition.

Composition according to the invention can also contain, in addition to the ingredients already mentioned, various other optional ingredients such as structurants, colourants, hydrotropes, whiteners, optical brigb-teners, soil suspending agents, detersive enzymes, compatible bleaching agents (particularly hypohalites) , and preservatives such as sodium meta periodate.

The composition of the invention can be in the form of a liquid, gel, cream, bar, tablet, powder, aerosol, spray, foam, biphasic liquid, microemulsion, coil, mat, vaporizer, paste, or mousse and can also be impregnated on a suitable substrate to provide a slow release of the actives. A preferred form is a liquid composition of pH 11.5 to 13.0, more preferably an aqueous liquid. Various ways of delivering the insect repellent compound and the chlorine based disinfectant can be used. It can be in the form of dual compartment packaging for liquids and sprays, or partitioned in a tablet with an intermediate inert medium. The composition can also be delivered as a kit where the necessary ingredients are provided separately and mixed together when required. The liquid product can be used either as a neat solution or can be diluted depending on the consumer requirement and type of insect infestation.

The composition of the invention can be made by any conventional process known in the art. Preferred process of preparing the composition is by preparing a solution of the chlorine based disinfecting compound along with surfactant in water followed by mixing of the insect repellent compound in a mixer. Other optional ingredients such as thickeners, perfumes, colour and preservatives can be sequentially added to the above while mixing at around 25 ⁰C.

The invention will now be illustrated with the help of the following non-limiting examples:

The composition is suitable for repelling many different nuisance insects, but is particularly useful for repelling ants and cockroaches, particularly the latter. EXAMPLES

Example 1-3

The compositions as shown in Table-1 were preparing using

3% of the insect-repellent compound in a 1.5% solution of a surfactant viz . amine oxide in water with and without the sodium hypochlorite solution . The compositions so prepared were tested for repellency of ants using the following test procedure .

Test procedure for repellency of ants

A glazed ceramic tile (20 x 20 cm) , white in colour, is cleaned with water and alcohol . A filter paper (Whatman filter paper 95 sq . cm) is soaked with 5 mL of sugar solution and centrally placed on the white tile . The area outside the filter paper on the tile is applied with the insect repellent composition . The tile is placed near an ant' s nest . The time up which no ants are observed feeding on the sugar in the filter paper is noted as the time for 100% repellency .

The data on repellency is summarized in Table -1. Table-1 also indicates the synergistic effect of including sodium hypochlorite in each of the compositions prepared. Table-1

The data in Table-1 indicates that the insect repellent compositions of the invention are highly effective in repelling insects and there is synergistic benefit in including a chlorine based disinfecting compound e.g. sodium hypochlorite in the composition.

Examples 4-5 The compositions as shown in Table-2 were preparing using

1% of the insect-repellent compound in a 1.5% solution of a surfactant viz. amine oxide in water with and without the sodium hypochlorite solution. Repellency tests were conducted using the following procedure on another type of insect viz. housefly and the results are summarized in Table-2. Test procedure for repellency of housefly

A glass cage 1 x 1 x 1 m is cleaned dry. A solution of the insect repellent composition is applied on the sides of the cage and allowed to dry. 25 adult houseflies are released into the cage. A small port is provided for flies to come outside the cage. The number of flies coming out of the port over a time period of one hour is counted.

% repellency is reported as [Number of flies that came out of the cage]/ [Number of flies released into the cage] * 100.

Table-2

The data in table-2 indicates that the insect repellent compounds of the invention provide for synergistic benefit in repelling houseflies in the presence of the chlorine based disinfectant compound.

Examples 6-8

The compositions as shown in Table-3 were preparing using

1% of the insect-repellent compound in a 1.5% solution of a surfactant viz. amine oxide in water along with 1.6% of a sodium hypochlorite solution. Repellency tests were conducted using the following procedure on another type of insect viz. cockroaches and the results are summarized in Table-3.

Test procedure for repellency of cockroaches:

PVC drainpipe of standard dimension is cleaned with water followed with alcohol swipe. About 5 ml of the insect repellent composition is applied on the inside of the tube using a cotton swab attached to a rod. The exact amount of product is quantified by weighing the swab before and after application. 30 adult cockroaches are released into the pipe and the ends are closed with paper and a rubber band. The tube is then placed horizontally. The equilibration time is 5 minutes post which the ends of the tube are opened on the floor. The number of cockroaches repelled from the tube are counted after 15 minutes. The % repellency is given by [Number of cockroaches outside the tube] /[Number of cockroaches originally introduced in the tube]*100..

Table-3

Data in table-3 indicates that very high repellency against cockroaches could be obtained with the compositions of the invention. Example-9

A sustained repellency test study was conducted using the procedure followed in Examples 6-8 with the composition made from 3% diphenyl methane. The repellency of the cockroaches to the composition was observed for up to 8 hours and the data is summarized in Table-4.

Table-4

The data in table-4 indicates that the use of the insect repellent composition according to the invention provides for sustained repellency of cockroaches over a long period of time.

Claims

1. An insect repellent composition comprising

(a) 0.01 to 90% by weight of an insect repellent compound selected from the group comprising di- phenyl-methane, beta-naphthol methyl ether, naphthalene, or benzophenone,

(b) 0.5 to 25% by weight of a surfactant,

(c) 0.1 to 6% by weight of a chlorine based disinfecting compound

(d) the balance being water

2. A composition according to claim 1 wherein the surfactant is present in an amount of 1 to 15% by weight of the composition.

3. A composition according to claim 2 wherein the surfactant is present in an amount of 2 to 10% by weight of the composition.

4. A composition according to any one of the preceding claims wherein the surfactant is chosen from anionic or nonionic type.

5. A composition according to any one of the preceding claims wherein the insect repellent compound is present in an amount of 0.1 to 50% by weight of the composition.

6. A composition according to claim 5 wherein the insect repellent compound is present in an amount of 0.5 to 25% by weight of the composition.

7. A composition according to any one of the preceding claims wherein the chlorine based disinfecting compound is present in an amount of 0.5 to 5% by weight of the composition.

8. A composition according to any one of the preceding claims wherein the chlorine based disinfecting compound is an alkali metal hypochlorite or alkaline earth metal hypochlorite.

9. A composition according to any one of the preceding claims wherein the composition has a pH in the range of 11 to 13.

10. A composition according to any one of the preceding claims wherein the composition is in the form of a liquid, gel, cream, bar, powder, tablet, aerosol, spray, foam, biphasic liquid, microemulsion, coil, mat, vaporizer, paste or mousse.