Personal care formulations comprising an imidazoline quaternary compound

Abstract

The present invention provides a personal care formulation comprising 0.1% to 15% by weight, based on the total weight of the formulation, of a di-alkyl imidazoline quaternary compound which comprises two alkyl groups which are independently selected from branched C12 to C19 alkyl groups. The invention further provides a method of treating hair comprising the compound and the use of the compound for the treatment of hair.

Description

[0001] Personal Care formulations comprising an imidazoline quaternary compound

[0002] Field of the Invention

[0003] The present invention relates to personal care formulations comprising an imidazoline quaternary compound, in particular for application to human skin or hair. The invention further relates to the use of imidazoline quaternary compounds, preferably in hair care formulations.

[0004] Background

[0005] The need for hair care products is well-known. Such products may be used for cleaning, conditioning or styling human hair and / or addressing various problems encountered with human hair, for example, damage by treatments such as bleaching or colouring or by environmental factors, such as sun, heat and pollution. Some hair care products are also directed at improving qualities of the hair such as strength, shine or ease of brushing / combing.

[0006] W02005 / 089702 discloses aqueous hair treatment compositions which comprise a mono- C14-C22 trimethylammonium surfactant, a di-(C2o-C24) imidazoline quaternary surfactant, and a mono-Ci2-C22 alkyl hydroxyethyl dimethylammonium surfactant and which provide improved hair conditioning benefits.

[0007] There is a continual need for the development of improved personal care products and formulations, in particular hair care formulations, and ingredients.

[0008] Summary of the Invention

[0009] It is an object of the present invention to address one or more disadvantages associated with the prior art.

[0010] According to a first aspect, the present invention provides a personal care formulation comprising 0.1% to 15% by weight, based on the total weight of the formulation, of a di- alkyl imidazoline quaternary compound which comprises two alkyl groups which are independently selected from branched C12 to C19 alkyl groups.

[0011] According to a second aspect, the present invention provides a method of treating hair comprising the step of applying to hair a formulation comprising a di-alkyl imidazoline quaternary compound which comprises two alkyl groups which are independently selected from branched Ci2to C19 alkyl groups.

[0012] According to a third aspect, the present invention provides the use of a composition comprising a di-alkyl imidazoline quaternary compound which comprises two alkyl groups which are independently selected from branched Ci2 to C19 alkyl groups, for the treatment of hair.

[0013] Surprisingly, it has been found by the inventors that using branched alkyl groups, particularly isostearyl groups, in the imidazoline quaternary compound, the properties of the compound unexpectedly change and allow for the design of improved personal care formulations, particularly transparent formulations. Surprisingly, the imidazoline quaternary compound may be biodegradable and cold-processable. The biodegradability of the dialkyl imidazoline quaternary compound may be measured by OECD 301 as described herein.

[0014] All of the features described herein may be combined with any of the above aspects, in any combination.

[0015] Detailed Description of the Invention

[0016] It will be understood that any upper or lower quantity or range limit used herein may be independently combined.

[0017] It will be understood that, when describing the number of carbon atoms in a substituent group (e.g. ‘Ci to Ce’), the number refers to the total number of carbon atoms present in the substituent group, including any present in any branched groups. Additionally, when describing the number of carbon atoms in, for example fatty acids, this refers to the total number of carbon atoms including the one at the carboxylic acid, and any present in any branch groups. Many of the chemicals which may be used to produce the composition of the present invention are obtained from natural sources. Such chemicals typically include a mixture of chemical species due to their natural origin. Due to the presence of such mixtures, various parameters defined herein can be an average value and may be non-integral.

[0018] The term ‘quaternary compound’ or ‘quat’ means a compound comprising a quaternary nitrogen atom.

[0019] The term ‘personal care’ means human personal care. The term ‘hair care’ means human hair care. A personal care ingredient is suitable for use on the human body. A hair care ingredient is suitable for use on human hair.

[0020] The term ‘personal care formulation’ when used herein means a consumer product intended to be applied to the human body or any part thereof for cleansing, beautifying, or improving appearance. Personal care formulations include but are not limited to cosmetics; deodorants; bar soaps; liquid soaps; facial and body washes; facial and body cleansers; hair shampoos; hair conditioners; hair oils; hair pomades; hair serums; shaving creams or gels. A personal care formulation does not include any product for which a prescription is required.

[0021] The formulation of the invention may be a topical formulation (i.e. for use on the outside of the body), preferably a topical formulation for application to skin or hair (i.e. human skin or hair), more preferably a topical formulation for application to hair. The formulation of the invention may be a cosmetic formulation.

[0022] The term ‘transparent’ when used herein means a percentage transmittance of at least 90% at 760 nm when measured using a spectrophotometer, preferably when using a UV- Vis spectrophotometer, particular when using a Shimadzu UV-1800 UV-Vis spectrophotometer.

[0023] The transmittance measures the amount of light that can pass through the material. Percentage transmittance is defined as the percentage of light that can be transmitted through the material. A higher value of percentage transmittance indicates a higher transparency of the material. Percentage transmittance may be measured with regard to a reference sample. Di-alkyl imidazoline quaternary compound

[0024] The di-alkyl imidazoline quaternary compound of the invention comprises two alkyl groups which are independently selected from branched Ci2 to C19 alkyl groups.

[0025] As further described in the Examples, the di-alkyl imidazoline quaternary compound may be made by reacting a branched fatty acid with diethylenetriamine to produce an imidazoline intermediate with branched alkyl groups. The imidazoline intermediate may they be reacted with a suitable quaternising agent to produce the final quaternary compound. The quaternary compound may then be diluted with a suitable diluent to reduce its viscosity and make it easier to handle at room temperature.

[0026] Each branched alkyl group comprises at least 12 carbon atoms, preferably at least 14 carbon atoms, preferably at least 16 carbon atoms, preferably at least 17 carbon atoms. Each branched alkyl group comprises at most 19 carbon atoms. Preferably each branched alkyl group is saturated. Preferably at least one of the alkyl groups is an isostearyl group.

[0027] Preferably, each of the alkyl groups is an isostearyl group. Branched alkyl groups, such as isostearyl groups, may provide a surprising balance of beneficial effects, including improving the oil-solubility of the di-alkyl imidazoline quaternary compound and / or providing one or more beneficial effects in hair treatment and / or enabling a transparent personal care formulation to be made. Preferably the di-alkyl imidazoline quaternary compound is an isostearamidoethyl-isostearylmethylimidazolinium.

[0028] As is well known in the art, a suitable quaternising agent will react with the imidazoline intermediate to provide a quaternary nitrogen cation on the di-alkyl imidazoline quaternary compound and a corresponding counter-ion (anion). The counter-ion (anion) of the di-alkyl imidazoline quaternary compound may be selected from chloride, bromide, iodide, fluoride, sulfate, methosulfate, ethosulfate, methanebenzylsulfonate, phosphate, nitrite, nitrate, carboxylate, betaines and mixtures thereof. Preferably the counter-ion is selected from methosulfate and ethosulfate, particularly methosulfate.

[0029] Preferably the di-alkyl imidazoline quaternary compound is isostearamidoethyl- isostearylmethylimidazolinium methosulfate. The di-alkyl imidazoline quaternary compound may be represented by formula (1) in which each R group is independently a branched Ci2 to C19 alkyl group.

[0030] The di-alkyl imidazoline quaternary compound may comprise at least two nitrogen atoms, preferably at least 3. The di-alkyl imidazoline quaternary compound may comprise at most 5 nitrogen atoms, preferably at most 4, particularly at most 3. Preferably, the di-alkyl imidazoline quaternary compound comprises 3 nitrogen atoms.

[0031] The di-alkyl imidazoline quaternary compound comprises at least one quaternary nitrogen atom. Preferably the di-alkyl imidazoline quaternary compound comprises one quaternary nitrogen atom. The di-alkyl imidazoline quaternary compound may comprise at least one secondary nitrogen atom. Preferably the di-alkyl imidazoline quaternary compound comprises one secondary nitrogen atom. The di-alkyl imidazoline quaternary compound may comprise at least one tertiary nitrogen atom. Preferably the di-alkyl imidazoline quaternary compound comprises one tertiary nitrogen atom.

[0032] Preferably, the di-alkyl imidazoline quaternary compound comprises, one secondary nitrogen atom, one tertiary nitrogen atom and one quaternary nitrogen atom.

[0033] An advantage of the di-alkyl imidazoline quaternary compound of the invention is that it is biodegradable, preferably readily biodegradable. The biodegradability of the di-alkyl imidazoline quaternary compound may be measured by a method under OECD 301 B, as described in the Test Methods herein. The di-alkyl imidazoline quaternary compound, when tested for biodegradability using the method described in OECD 301 B, preferably has a mean degradation value of at least 60% after 30 days, preferably at least 70%, more preferably at least 80%, yet more preferably at least 90%.

[0034] Diluent Preferably the personal care formulation further comprises a diluent selected from triglycerides, mono-esters and di-esters. The diluent may advantageously improve the flowability or processability of the di-alkyl imidazoline quaternary compound, preferably by reducing viscosity, particularly by making the viscosity at room temperature of the diluted di-alkyl imidazoline quaternary compound suitable for addition to a personal care formulation without the need for heating or specialist pumping equipment.

[0035] Preferably the diluent is selected from a saturated or unsaturated triglyceride of C4 to C14 fatty acids. Preferably the fatty acids in the triglyceride comprise at least 6 carbon atoms, preferably at least 7 carbon atoms. Preferably the fatty acids in the triglyceride comprise at most 12 carbon atoms, preferably at most 11 carbon atoms. Surprisingly such a diluent may enable the diluted di-alkyl imidazoline quaternary compound to be included a personal care formulation at room temperature (i.e. about 23-25°C) while maintaining other beneficial properties such as the transparency of the formulation and / or beneficial effects on application to hair. Preferably the diluent is a triglyceride of Cs to C10 fatty acids, which may also be known as capric / caprylic triglyceride (CCTG).

[0036] The diluent may be selected from mono-esters. Suitable mono-esters for inclusion in personal care formulations comprise mono-esters which are included on the INCI (International Nomenclature of Cosmetic Ingredients) register. An example of a suitable mono-ester is isopropyl myristate.

[0037] The diluent may be selected from di-esters which are known to the skilled person as suitable for inclusion in personal care formulations. An example of a suitable di-ester is dioctyl succinate.

[0038] The diluent is preferably derived from renewable and / or bio-based sources. The level of this may be determinable by ASTM D6866 as a standardised analytical method for determining the bio-based content of samples using14C radiocarbon dating. ASTM D6866 distinguishes carbon resulting from bio-based inputs from those derived from fossil-based inputs. Using this standard, a percentage of carbon from renewable sources can be calculated from the total carbon in the sample.

[0039] Preferably, the diluent has a renewable carbon content of at least 80 wt%, more preferably at least 90 wt%, particularly at least 95 wt%, desirably 100 wt% when determined using ASTM D6866. A high renewable carbon content may be advantageous in improving the environmental profile of the personal care formulation.

[0040] Personal Care and / or Hair Care Formulations

[0041] The present invention provides a personal care formulation comprising 0.1% to 15% by weight, based on the total weight of the formulation, of a di-alkyl imidazoline quaternary compound, wherein the alkyl groups are selected from branched Ci2 to C19 alkyl groups.

[0042] Preferably the personal care formulation is for topical application to skin or hair.

[0043] The personal care formulation may comprise at least 0.2 wt%, based on the total weight of the formulation, of the di-alkyl imidazoline quaternary compound, preferably at least 0.5 wt%, preferably at least 1 wt%, preferably at least 1.5 wt%, preferably at least 2 wt%. The personal care formulation may comprise at most 10 wt%, based on the total weight of the formulation, of the di-alkyl imidazoline quaternary compound, preferably at most 8 wt%, preferably at most 6 wt%, preferably at most 4 wt%.

[0044] Preferably the personal care formulation further comprises 0.01% to 10% by weight, based on the total weight of the formulation, of a diluent selected from triglycerides, mono-esters and di-esters.

[0045] The personal care formulation may comprise at least 0.05 wt%, based on the total weight of the formulation, of the diluent, preferably at least 0.12 wt%, preferably at least 0.25 wt%, preferably at least 0.37 wt%, preferably at least 0.5 wt%. The personal care formulation may comprise at most 5 wt% based on the total weight of the formulation, of the diluent, preferably at most 2.5 wt%, preferably at most 2 wt%, preferably at most 1.5 wt%, preferably at most 1 wt%.

[0046] The weight ratio of di-alkyl imidazoline quaternary compound to diluent in the personal care formulation may be at most 10:1 , preferably at most 8:1 , particularly at most 6:1. The weight ratio of di-alkyl imidazoline quaternary compound to diluent in the personal care formulation may be at least 1:1 , preferably at least 2:1, particularly at least 3:1.

[0047] Surprisingly such a weight ratio may enable the diluted di-alkyl imidazoline quaternary compound to be included a personal care formulation at room temperature (i.e. about 23- 25°C) while maintaining other beneficial properties such as the transparency of the formulation and / or beneficial effects on application to hair.

[0048] Preferably the personal care formulation further comprises a personal care ingredient selected from a cleaning agent, hair conditioning agent, hair oil, hair styling agent, antidandruff agent, hair growth promoter, perfume, sunscreen, sunblock, pigment, moisturizer, film former, hair color, make-up agent, thickening agent, emulsifier, humectant, emollient, antiseptic agent, deodorant active, dermatologically acceptable carrier, surfactant, abrasive, absorbent, fragrance, colorant, essential oil, astringent, anti-acne agent, anticaking agent, anti-foaming agent, anti-oxidant, binder, enzyme, enzyme inhibitor, enzyme activator, coenzyme, botanical extract, ceramide, buffering agent, bulking agent, chelating agent, cosmetic biocide, external analgesic, substantivity increasing agent, opacifying agent, pH adjuster, reducing agent, sequestrant, skin bleaching and / or lightening agent, skin conditioning agent, skin soothing and / or healing agent, skin treating agent, vitamin or preservative.

[0049] Preferably the personal care formulation is a topical hair care formulation.

[0050] Preferably the personal care formulation further comprises a hair care ingredient selected from shine enhancers, moisturisers, herbal additives, hair strengtheners, vitamin additives, colorants, hair thickening agents; setting and styling agents; ultraviolet absorbers; silicone oils; essential oils and fragrances; thickening or viscosity-enhancing agents; detergents; surfactants; cleaning agents; stabilising agents; emollients; chelating agents; sequestering agents; preservatives; disinfectants; anti-oxidants / radical scavengers; antistatic agents; conditioning agents; detangling ingredients; emulsifying or dispersing agents.

[0051] The personal care formulation may have a range of different consistencies and / or viscosities depending on the desired end use of the formulation.

[0052] The personal care formulation may have a percentage transmittance, preferably measured by UV-Vis spectrophotometer, of at least 70%, preferably at least 80%, more preferably at least 90%. The personal care formulation may be transparent, preferably measured as described herein. The personal care formulation may be selected from moisturizers, body butters, gel creams, high perfume containing products, perfume creams, hair conditioners, hair relaxer formulations, hair shampoos, hair styling products, leave-on hair products, water-free products, anti-perspirant and deodorant products, cleansers, 2-in-1 foaming emulsions, emulsifier free products, mild formulations, scrub formulations e.g. containing solid beads, silicone in water formulations, pigment containing products, sprayable emulsions such as hair detanglers, colour cosmetics, shower products, make-up remover, eye make-up remover, and wipes. More preferably, the end use applications of such formulations include hair conditioners, hair relaxer formulations, hair shampoos, hair styling products, leave-on hair products and sprayable emulsions such as hair detanglers.

[0053] A preferred further component of the personal care formulation, particularly hair care formulation according to the invention is a conditioning oil. Preferably the conditioning oil is water-insoluble. By water-insoluble is meant that the solubility in water at 25°C is 0.01% by weight or less. It is preferred if the conditioning oil is non-volatile, by which it is meant that the vapour pressure of the oil at 25 °C is less than 10 Pa.

[0054] As used herein, the term "conditioning oil" includes any material, which is used to give a particular conditioning benefit to hair. For example, suitable materials are those, which deliver one or more benefits selected from improved shine, softness, comb-ability, wethandling, anti-static properties, body, volume, style-ability, manageability and protection against damage.

[0055] Suitable conditioning oils are selected from hydrocarbon oils, fatty esters, triglycerides, and mixtures thereof.

[0056] Hydrocarbon oils include cyclic hydrocarbons, straight chain aliphatic hydrocarbons (saturated or unsaturated), and branched chain aliphatic hydrocarbons (saturated or unsaturated). Straight chain hydrocarbon oils will preferably contain from about 12 to about 30 carbon atoms. Branched chain hydrocarbon oils can and typically may contain higher numbers of carbon atoms. Also suitable are polymeric hydrocarbons of alkenyl monomers, such as C2-C6 alkenyl monomers. These polymers can be straight or branched chain polymers. The straight chain polymers will typically be relatively short in length, having a total number of carbon atoms as described above for straight chain hydrocarbons in general. The branched chain polymers can have substantially higher chain length. The number average molecular weight of such materials can vary widely, but will typically be up to about 2000, preferably from about 200 to about 1000, more preferably from about 300 to about 600.

[0057] Specific examples of suitable hydrocarbon oils include paraffin oil, mineral oil, saturated and unsaturated dodecane, saturated and unsaturated tridecane, saturated and unsaturated tetradecane, saturated and unsaturated pentadecane, saturated and unsaturated hexadecane, and mixtures thereof. Branched-chain isomers of these compounds, as well as of higher chain length hydrocarbons, can also be used.

[0058] Particularly preferred hydrocarbon oils are the various grades of mineral oils. Mineral oils are clear oily liquids obtained from petroleum oil, from which waxes have been removed, and the more volatile fractions removed by distillation. The fraction distilling between 150°C to 300°C is termed mineral oil, and it consists of a mixture of hydrocarbons.

[0059] Suitable fatty esters are characterised by having at least 10 carbon atoms and include esters with hydrocarbyl chains derived from fatty acids or alcohols, e.g., monocarboxylic acid esters, polyhydric alcohol esters, and di- and tricarboxylic acid esters. The hydrocarbyl radicals of the fatty esters hereof can also include or have covalently bonded thereto other compatible functionalities, such as amides and alkoxy moieties, such as ethoxy or ether linkages. Monocarboxylic acid esters include esters of alcohols and / or acids of the formula R'COOR in which R' and R independently denote alkyl or alkenyl radicals and the sum of carbon atoms in R' and R is at least 10, preferably at least 20. Specific examples include, for example, alkyl and alkenyl esters of fatty acids having aliphatic chains with from about 10 to about 22 carbon atoms, and alkyl and / or alkenyl fatty alcohol carboxylic acid esters having an alkyl and / or alkenyl alcohol-derived aliphatic chain with about 10 to about 22 carbon atoms, benzoate esters of fatty alcohols having from about 12 to 20 carbon atoms. The monocarboxylic acid ester need not necessarily contain at least one chain with at least 10 carbon atoms, so long as the total number of aliphatic chain carbon atoms is at least 10. Examples include isopropyl isostearate, isopropyl myristate, hexyl laurate, isohexyl laurate, isohexyl palmitate, isopropyl palmitate, decyl oleate, isodecyl oleate, hexadecyl stearate, decyl stearate, isopropyl isostearate, dihexyldecyl adipate, lauryl lactate, myristyl lactate, cetyl lactate, oleyl stearate, oleyl oleate, oleyl myristate, lauryl acetate, cetyl propionate, and oleyl adipate. Di- and trialkyl and alkenyl esters of carboxylic acids can also be used. These include, for example, esters of succinic acid, glutaric acid, adipic acid, hexanoic acid, heptanoic acid, and octanoic acid. Examples include diisopropyl adipate, diisohexyl adipate, and diisopropyl sebacate. Other specific examples include isocetyl stearoyl stearate, and tristearyl citrate.

[0060] Polyhydric alcohol esters include alkylene glycol esters, for example ethylene glycol mono and di-fatty acid esters, diethylene glycol mono- and di-fatty acid esters, polyethylene glycol mono- and di-fatty acid esters, propylene glycol mono- and di-fatty acid esters, polypropylene glycol monooleate, polypropylene glycol monostearate, ethoxylated propylene glycol monostearate, polyglycerol poly-fatty acid esters, ethoxylated glyceryl monostearate, 1,3-butylene glycol monostearate, 1 ,3-butylene glycol distearate, polyoxyethylene polyol fatty acid ester, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters and mono-, di-and triglycerides.

[0061] Particularly preferred fatty esters are mono-, di- and triglycerides, more specifically the mono-, di-, and tri- esters of glycerol and long chain carboxylic acids such as C10-C22 carboxylic acids. A variety of these types of materials can be obtained from vegetable and animal fats and oils, such as coconut oil, castor oil, safflower oil, sunflower oil, cottonseed oil, corn oil, olive oil, cod liver oil, almond oil, avocado oil, palm oil, sesame oil, peanut oil, lanolin and soybean oil. Synthetic oils include triolein and tristearin glyceryl dilaurate.

[0062] Specific examples of preferred materials include cocoa butter, palm stearin, sunflower oil, soyabean oil and coconut oil.

[0063] The personal care formulation may comprise at least 0.1 wt%, based on the total weight of the formulation, of the conditioning oil, preferably at least 0.5 wt%, preferably at least 1.0 wt%, preferably at least 1.5 wt%, preferably at least 2.0 wt%. The personal care formulation may comprise at most 5.0 wt%, based on the total weight of the formulation, of the conditioning oil, preferably at most 4.5%, preferably at most 4 wt%, preferably at most 3.0 wt%.

[0064] The personal care (or hair care) formulation according to the present invention may also contain other additional emollient materials, preferably emollient oils. Preferably, the emollient oil is a polar or non-polar oil. Examples of emollient oils which are suitable for use in the present formulation include mineral or paraffin oil; esters of fatty acids and fatty alcohols, preferably C10-C20 acids or alcohols, although isopropyl esters may be used; fatty acid glycol esters; fatty acid triglycerides; esters and diesters of alkoxylated fatty alcohols; botanical (plant) extracts; and hydrocarbons, preferably C12-C16. Preferably, the emollient is mineral oil. When present in the formulation, each additional emollient is preferably present at a concentration of at least 1 % and up to 30% by weight based on the total weight of the formulation.

[0065] The personal care (or hair care) formulation according to the present invention may also contain one or more surfactants, for example sodium lauryl ether (or laureth) sulphate and / or cocam idopropyl betaine. When present in the formulation, each surfactant is preferably present at a concentration of between 1% and 20%, preferably between 2% and 15% and more preferably between 4% and 10% by weight based on the total weight of the formulation.

[0066] The personal care (or hair care) formulation according to the present invention may also contain one or more cationic ingredients. When present in the formulation, each cationic ingredient is preferably present at a concentration of between 0.01 % and 10%, preferably between 0.05% and 8% and more preferably between 0.1 % and 5% by weight based on the total weight of the formulation.

[0067] The personal care (or hair care) formulation according to the present invention may also contain one or more film forming components. When present in the formulation, each film forming component is preferably present at a concentration of between 0.01% and 5%, preferably between 0.05% and 3% and more preferably between 0.1% and 2% by weight based on the total weight of the formulation.

[0068] Many other components that may be used in the formulations according to the present invention. These components may be oil soluble, water soluble or non-soluble. Examples of such materials include:

[0069] (i) preservatives, preferably those approved for cosmetic use, particularly as listed in Annex 5 of the European Union cosmetics regulations. The preservative preferably comprises sodium benzoate, potassium sorbate or phenoxyethanol. The preservative may comprise parabens (alkyl esters of 4-hydroxybenzoic acid), substituted ureas or hydantoin derivatives, e.g. those sold commercially under the trade names Germaben II, Nipaguard BPX and Nipaguard DMDMH. The preservative may be used at a concentration in the range from 0.5 wt.% to 2 wt.% based on the total weight of the composition;

[0070] (ii) perfumes, when used typically at a concentration in the range from 0.1 wt.% to 10 wt.% more usually up to about 5 wt.% and particularly up to about 2 wt.%, based on the total weight of the composition;

[0071] (iii) humectants or solvents such as alcohols, polyols such as glycerol and polyethylene glycols, when used typically at a concentration in the range from 1 wt.% to 10 wt.% based on the total weight of the composition;

[0072] (iv) alpha hydroxy acids such as glycolic, citric, lactic, malic, tartaric acids and their esters; self-tanning agents such as dihydroxyacetone;

[0073] (v) vitamins and their precursors including: (a) Vitamin A, e.g. as retinyl palmitate and other tretinoin precursor molecules, (b) Vitamin B, e.g. as panthenol and its derivatives, (c) Vitamin C, e.g. as ascorbic acid and its derivatives, (d) Vitamin E, e.g. as tocopheryl acetate, (e) Vitamin F, e.g. as polyunsaturated fatty acid esters such as gammalinolenic acid esters;

[0074] (vi) skin care agents such as ceramides either as natural materials or functional mimics of natural ceramides;

[0075] (vii) natural phospholipids, e.g. lecithin;

[0076] (viii) silicones;

[0077] (ix) botanical extracts with beneficial skin care properties;

[0078] (x) skin whiteners such as kojic acid, arbutin and similar materials;

[0079] (xi) skin repair compounds actives such as Allantoin and similar series;

[0080] (xii) caffeine and similar compounds;

[0081] (xiii) cooling additives such as menthol or camphor;

[0082] (xiv) insect repellents such as N,N-diethyl-3-methylbenzamide (DEET) and citrus or eucalyptus oils;

[0083] (xv) essential oils; and

[0084] (xvi) pigments, including microfine pigments, particularly oxides and silicates, e.g. iron oxide, particularly coated iron oxides, and / or titanium dioxide, and ceramic materials such as boron nitride, or other solid components, such as are used in make-up and cosmetics, to give suspoemulsions, typically used in an amount in the range from 1 wt.% to 15 wt.%, but usually at least 5 wt.%, and particularly about 10 wt.% based on the total weight of the formulation. The formulations may comprise a fragrance-imparting material to provide a pleasant scent. In one aspect, a scent is provided from a natural source, such as but not limited to alfalfa, almond, amber, angelica root, anise, apple, apricot, banana, basil, bay, bay laurel, benzoin, bergamot, bitter orange, black pepper, bois de rose (rosewood), cajeput, cardamom, carrot seed, cedarwood, cinnamon, citronella, citrus, clary sage, clove, cocoa, coconut, coffee, coriander, cranberry, cypress, elemi, eucalyptus globulous, eucalyptus, fennel, frankincense, galbanum, geranium, German chamomile, ginger, grapefruit, helichrysum, hyssop, jasmine, juniper berry, lavender, lemon, lemongrass, lily, linden blossom, mango, marjoram, melissa, mint, myrrh, myrtle, neroli, niaouli, nutmeg, orange, oregano, palm, parsley, patchouli, peach, peppermint, petitgrain, pine, pineapple, raspberry, Roman chamomile, rose, rosemary, sandalwood, spearmint, spruce, strawberry, tea, thyme, vanilla, vetiver, violet, yarrow, ylang ylang, and the like. Preferably, the fragrance is selected from mint or vanilla.

[0085] The invention may provide a hair care formulation comprising the composition of the invention and a hair care ingredient. Preferably the hair care formulation is for topical application to hair.

[0086] The hair care ingredient may be selected from shine enhancers, moisturisers, herbal additives, hair strengtheners, vitamin additives, colorants, hair thickening agents; setting and styling agents; ultraviolet absorbers; silicone oils; essential oils and fragrances; thickening or viscosity-enhancing agents; detergents; stabilising agents; emollients; chelating agents; sequestering agents; preservatives; disinfectants; anti-oxidants / radical scavengers; antistatic agents; conditioning agents; detangling ingredients; emulsifying or dispersing agents.

[0087] Preferably the hair care formulation is a hair cleansing, conditioning, de-tangling, colourprotecting or styling formulation, particularly preferably a hair cleansing or conditioning formulation.

[0088] The hair care formulation may comprise a silicone fluid or oil such as dimethylpolysiloxane, dimethyl silicone, highly polymerised methyl polysiloxane, and methyl polysiloxane, known generically as dimethicone, cyclic oligomeric dialkylsiloxanes, such as the cyclic oligomers of dimethylsiloxane, known generically as cyclomethicone. The concentration of silicone oil in the formulation may preferably be in the range from 0.1 wt.% to 40 wt.%, more preferably 0.3 wt.% to 20 wt.%, particularly 0.5 wt.% to 5 wt.%, and especially 1 wt.% to 1.5 wt.% based on the total weight of the formulation. Alternatively, the hair care formulation may not comprise a silicone compound.

[0089] The hair care formulation may contain many different types of functional ingredients such as;

[0090] (i) cationic hair conditioning agents, e.g. ethoxylated phosphate fatty quats, such as those sold by Croda as Ariasilk™; fatty amido amines, such as those sold by Croda as Incromine™; fatty quats, such as those sold by Croda as Incroquat™, Crodazosoft™, Rejuvasoft™ or VibraRiche™ typically used at a concentration in the range from 1 wt.% to 5 wt.% based on the total weight of the composition. These are typically combined with polymeric hair conditioning cationic materials such as quaternised cellulose sold by Croda as Crodacel™ and MiruStyle™, quaternised proteins, such as those sold by Croda, as Croquat™, Crosilkquat™, Kerestore™ and Hydrotriticum™.

[0091] (ii) fatty alcohols, e.g. stearyl, cetearyl, cetyl, oleyl alcohols, used typically at a concentration range of 2 wt.% to 5 wt.% based on the total weight of the composition.

[0092] (iii) humectants or solvents, e.g. alcohols and polyols such as glycerol and polyethylene glycols, when used typically at a concentration in the range from 1 wt.% to 10 wt.% based on the total weight of the composition;

[0093] (iv) reconstructors, e.g. hydrolysed proteins such as wheat protein, which function to penetrate the hair and strengthen the hair structure through polymer crosslinking;

[0094] (v) glossing or detangling materials which bind to the hair and reflect light, e.g. silicones such as dimethicone, phenyltrimethicone, dimethiconol and / or trimethylsilylamodimethicone, usually at a concentration in the range from 0.2 wt.% to 10 wt.% based on the total weight of the composition;

[0095] (vi) acidity regulators, e.g. citric acid, lactic acid, which generally maintain the pH of the conditioner at about 4 to 6;

[0096] (vii) thermal protectors, usually heat-absorbing polymers, which shield the hair against excessive heat, e.g. caused by blow-drying or curling irons or hot rollers such as for instance those sold by Croda as Mirustyle™ MFP (quaternised starch); and

[0097] (viii) UV protection agents, to protect hair or formulation components from degradation by UV light, such as those sold by Croda as Crodasorb™ UV-HPP.

[0098] Method of the Invention The invention provides a method of treating hair comprising the step of applying to hair a formulation comprising a di-alkyl imidazoline quaternary compound which comprises two alkyl groups which are independently selected from branched Ci2to C19 alkyl groups.

[0099] Preferably the method comprises one or more steps selected from bleaching, colouring, straightening, perming, curling, relaxing, fixing, holding, shaping, styling, thermal treatment, cleaning or conditioning of the hair.

[0100] The method may comprise any of the features described herein.

[0101] Use of the Invention

[0102] The invention provides the use of a composition comprising a di-alkyl imidazoline quaternary compound which comprises two alkyl groups which are independently selected from branched Ci2to C19 alkyl groups, for the treatment of hair.

[0103] Preferably the treatment of hair improves at least one of smoothness, shine, wet-combing and / or dry combing of hair, preferably measured as described herein.

[0104] Preferably the use of a composition comprising at least 3% by weight of the di-alkyl imidazoline quaternary compound, based on the total weight of the composition, for the treatment of hair provides a statistically significant reduction in the wet-combing force for the hair when compared with a control, as described herein. Preferably the statistical significance shows a p<0.01 value using a one-way ANOVA test.

[0105] Preferably the use of a composition comprising at least 3% by weight of the di-alkyl imidazoline quaternary compound, based on the total weight of the composition, for the treatment of hair provides a statistically significant reduction in the dry-combing force for the hair when compared with a control, as described herein. Preferably the statistical significance shows a p<0.05 value using a one-way ANOVA test.

[0106] The use may comprise any of the features described herein.

[0107] Any of the features described herein may be taken in any combination and with any aspect of the invention. Examples

[0108] The invention is illustrated by the following non-limiting examples. All parts and percentages are given by weight unless otherwise stated.

[0109] It will be understood that all tests and physical properties listed have been determined at atmospheric pressure and ambient / room temperature (i.e. about 23-25°C), unless otherwise stated herein, or unless otherwise stated in the referenced test methods and procedures.

[0110] Test Methods

[0111] In this specification the following test methods have been used:

[0112] (i) Wet-combing force was measured using a DiaStron MTT175 Miniature Tensile Tester for wet and dry combing and friction. The Diastron MTT175 is an industry standard Miniature Tensile Tester (MTT) which is well known to a person skilled in the art for measuring different properties of hair tresses, including Combing, Volume, Friction, Curl Compression, 3-point bending and Tensile. The combing attachment of the MTT175 allows the work required for combing a hair tress to be measured, in accordance with the wet combing test method described herein. The dry friction test method described herein uses the parallelogram friction test apparatus of the MTT175.

[0113] (ii) Dry-combing force was measured using a DiaStron MTT175 Miniature Tensile Tester for wet and dry combing and friction. The Diastron MTT175 is an industry standard Miniature Tensile Tester (MTT) which is well known to a person skilled in the art for measuring different properties of hair tresses, including Combing, Volume, Friction, Curl Compression, 3-point bending and Tensile. The combing attachment of the MTT175 allows the work required for combing a hair tress to be measured, in accordance with the wet combing test method described herein. The dry friction test method described herein uses the parallelogram friction test apparatus of the MTT175.

[0114] (iii) Smoothness of hair was measured using the following sensory protocol. For this sensory study, hair swatches were treated with different oils and then washed with plain SLES-based shampoo and dried overnight. 17 untrained panellists evaluated shine, smoothness, and ease of combing for dry hair swatches. They were then rated from 1 to 5 (1 being the least shine and smooth and 5 being the most shine and smooth).

[0115] (iv) Shine of hair was measured using the following sensory protocol. For this sensory study, hair swatches were treated with different oils and then washed with plain SLES-based shampoo and dried overnight. 17 untrained panellists evaluated shine, smoothness, and ease of combing for dry hair swatches. They were then rated from 1 to 5 (1 being the least shine and smooth and 5 being the most shine and smooth).

[0116] (v) Transparency was measured using a Shimadzu UV-1800 UV-Vis spectrophotometer.

[0117] (vi) Biodegradability was measured according to OECD 301(B) using a CO2 Evolution measurement protocol (Modified Sturm Test)

[0118] Example 1 - Synthesis of Sample A

[0119] 2 moles of C18 branched fatty acid (Isostearic Acid) and 1 mole of diethylenetriamine were placed in a dry stirred pressure vessel fitted with a nitrogen inlet. The vessel was purged with nitrogen and heated to 160-170° C for 5 hours until a desired base value was reached. The reaction mixture was then heated to 190-200° C and vacuum was applied for 8-10 hours to obtain a 94-98% tertiary amine content measured according to ASTM method No. D 2074. The resulting imidazoline intermediate was then cooled to 70° C and 0.95 moles of dimethyl sulfate were slowly added over a 60-minute period with stirring at 70-80° C. Once all dimethyl sulfate was added, the reaction mixture was held at 75-80° C for another 60 minutes.

[0120] A resulting light greenish yellow liquid product was formed comprising the diisostearyl imidazoline quat known as isostearamidoethyl-isostearylmethylimidazolinium methosulfate. The cationic activity of this product was more than 90% measured by titration. Then 20 wt% capric / caprylic triglyceride (CCTG) was added to the product at 70-80° C and stirred well for 60 minutes. The resulting composition was liquid & flowable at room temperature and will be referred to as Sample A.

[0121] The biodegradability of isostearamidoethyl-isostearylmethylimidazolinium methosulfate was tested according to OECD 301 B using a CO2 Evolution Test. All the treatments were added with equal volume of inoculum which was collected from the secondary effluent treatment plant receiving predominantly domestic sewage and volume made with mineral media. Treatment mixtures were aerated for 30 days with carbon dioxide (CO2) free air. The CO2 released was trapped in a series of bottles containing barium hydroxide, which were connected to the outlet of each test vessel. The residual barium hydroxide was measured on days 2, 4, 7, 10, 13 16, 19, 22, 25, 29 and 30 after the initiation of the test. The mean percent degradation of the sample was 98.57% at the end of test while, the percent degradation of reference item was 100% and the toxicity control was 100% at the end of the test. This shows the test item is not inhibitory to the test system. Based on the results, isostearamidoethyl-isostearylmethylimidazolinium methosulfate was concluded as readily biodegradable since degradation reached > 60% degradation in 10-day window period and also the sample was not inhibitory.

[0122] Example 2

[0123] The solubility of Sample A in various oils was tested as follows. Sample A was solubilised with various vegetable oils at 3 wt% dosage by stirring at room temperature. Solubility of sample A was determined by visual observation. Absence of any insoluble component or any haziness in the sample indicates miscibility of sample A in respective oil / carrier liquid, while presence of any insoluble component or any haziness in the sample indicates immiscibility of sample A in respective oil carrier liquid. The results of the tests are given in Table 1.

[0124] Table 1 - solubility of Sample A

[0125] Example 3

[0126] The transparency of Sample A compared with Crodazosoft DBQ (comprising di-behenyl imidazolinium methosulfate) in various oils was tested as follows.

[0127] Method for testing transparency of quats solubilized in oils:

[0128] 1. Sample A was solubilised with various Vegetable oils at 3 wt% dosage by stirring at room temp. Crodazosft DBQ was solubilised with various Vegetable oils 3 wt% dosage at 80°C with stirring.

[0129] 2. Percentage Transmittance readings were taken using UV-vis spectrophotometer (Shimadzu UV-1800) in triplets at 760nm with an average of the 3 readings being calculated.

[0130] 3. The transmittance is stated with reference to a Blank sample containing the neat Vegetable oil which is given a reference reading of 100.

[0131] Table 2 - transparency / transmittance of Sample A

[0132] Example 4

[0133] The effect of Sample A on wet combing of hair was tested as follows.

[0134] Indian virgin hair tresses were treated with 3 hair oil variants: Hair Oil 01 - coconut oil (Placebo)

[0135] Hair Oil 02 - 3 wt% Sample A + 97 wt% coconut oil

[0136] Hair Oil 03 - 4 wt% Sample A + 96 wt% coconut oil Treated hair tresses were rinsed with non-conditioning shampoo and wet and dry combing were evaluated using a DiaStron MTT175 which is an industry standard miniature tensile tester.

[0137] The evaluation steps were:

[0138] 1. Hair tresses were wetted with deionised water and then combed with a wide tooth comb to remove large knots.

[0139] 2. The tresses were then dunked once into water and the excess water removed while taking them out.

[0140] 3. T resses were then attached to the combing instrument of the Dia-Stron MTT 175 to measure the wet combing force of each tress.

[0141] 4. Tresses were removed from the clamp attachment after each measurement.

[0142] 5. Steps 2 to 4 were repeated until 5 consistent passes were captured

[0143] Results of the tests are given in Table 3. This study showed that the addition of Sample A in coconut oil at both dosages (3 wt% & 4 wt%) showed significant improvement in hair conditioning and detangling in wet combing and significant detangling in dry combing. Hair oil 02 and Hair oil 03 were significantly better than hair oil 01 in the reduction of both peak load (detangling) and total work (overall conditioning).

[0144] Table 3 - wet-combing force changes using Sample A p < 0.01, one-way ANOVA

[0145] The p value was calculated using one-way ANOVA based on 5 readings with calculations of average and standard deviation.

[0146] Example 5

[0147] The effect of Sample A on dry combing of hair was tested as follows.

[0148] The protocol was the same as for the wet combing (Example 4) using the Dia-Stron MTT175 except the test was done on dry hair under controlled humidity conditions: 1. Hair tresses were equilibrated in a chamber for at least 1 hour at 50% relative humidity.

[0149] 2. Tresses were then combed with a wide tooth comb to remove large knots before being attached onto a combing instrument.

[0150] 3. The dry combing force of each tress was measured by capturing 5 consistent passes.

[0151] The results are given in Table 4.

[0152] Table 4 - dry-combing force changes using Sample A p < 0.05, one-way ANOVA

[0153] The p value was calculated using one-way ANOVA based on 5 readings with calculations of average and standard deviation.

[0154] Example 6

[0155] Sample A was tested in a sensory study as follows.

[0156] The protocol comprised hair swatches were treated with different oils and then washed with plain SLES-based shampoo and dried overnight. 17 untrained panellists evaluated shine, smoothness, and ease of combing for dry hair swatches. They were then rated from 1 to 5 (1 being the least shine and smooth and 5 being the most shine and smooth).

[0157] Results are given in Table 5.

[0158] Table 5 - sensory study for Sample A

[0159] The Percentage mentioned in the above table indicates the preference of the panellist. From the above table it is clear that majority of the panellists preferred oil with sample A with respect to all the above three attributes.) Example 7

[0160] The following formulations are provided to show different ways in which the imidazoline quaternary compounds of the invention may be used in various personal care formulations.

[0161] Formulation A - Hair Pomade

[0162] Product / INCI Name Functionality % w / w

[0163] Part A

[0164] Deionised Water Solvent To 100

[0165] Glycerin Humectant 7.00

[0166] Propylene Glycol Humectant 2.50

[0167] Part B

[0168] Sample A (Isostearamidoethyl Conditioning 3.00

[0169] Isostearylmethylimidazolinium Methosulfate (and) agent

[0170] Caprylic / Capric Triglyceride)

[0171] Coconut Oil (Cocos Nucifera Oil) Natural emollient 2.00

[0172] Cresmer™ HE (PEG-7-Glyceryl Cocoate)1Emollient 4.00

[0173] Tween™ 20 (Polysorbate 20)1Co-Emulsifier 2.00

[0174] Brij™ CS25 (Ceteareth-25)1Emulsifier 20.00

[0175] Croduret™ 40 (PEG-40 Hydrogenated Castor Oil)1Solubiliser 2.00

[0176] Euxyl PE 9010 (Phenoxyethanol, Preservative 0.70

[0177] Ethylhexylglycerin)3

[0178] Chromatic2Fragrance 1.00

[0179] Suppliers: - 1 : Croda 2: Iberchem 3. Schulke & Mayr GmbH

[0180] Procedure to make Formulation A:

[0181] Weigh Part A (add 10% extra water to combat water loss) and heat it in water bath for 70- 75°C. Weigh Part B and heat it in water bath. Add Part B in Part A under high-speed stirring (600rpm) and continue heating. A transparent phase is formed. Add fragrance and preservative and stir for five minutes. Pour formula into the desired container in a heated phase and leave overnight to set.

[0182] Table 6 - properties of Formulation A

[0183] Formulation B - Hair Conditioner

[0184] Product / INCI Name Functionality % w / w

[0185] PART A

[0186] Deionised Water Solvent To 100

[0187] Glycerine Humectant 2.00

[0188] Disodium EDTA Chelating agent 0.20

[0189] PART B

[0190] Sample A (Isostearamidoethyl Conditioning agent 3.00

[0191] Isostearylmethylimidazolinium Methosulfate (and)

[0192] Caprylic / Capric Triglyceride)

[0193] NG Shea Unsaponifiable™ (Butyrospermum Parkii Natural emollient 3.00

[0194] (Shea) Butter Unsaponifiable)2

[0195] Cresmer™ EW (Proprietary blend)1Emulsifier 2.00

[0196] Polawax™ NF (Proprietary blend)1Emulsifier 3.00

[0197] Cetostearyl Alcohol Thickening agent 3.00

[0198] Crodamol™ BOSS (Phenoxy PEG-4 Emollient 3.00

[0199] Laurate / Palmitate)1

[0200] PART C

[0201] Cucumber Water3Fragrance 1.00

[0202] Euxyl PE 9010 (Phenoxyethanol, Preservative 0.70

[0203] Ethylhexylglycerin)4

[0204] Suppliers: - 1: Croda 2: Sederma 3: Iberchem 4. Schulke & Mayr GmbH

[0205] Procedure to make Formulation B: Separately combine Part A and B and heat up to 70-75°C. Add Part B to Part A under stirring (500-600rpm). Homogenise the system for a minute. Continue stirring till emulsion cools down to room temperature add Part C Table 7 - properties of Formulation B

[0206] Formulation C - Hair Shampoo

[0207] Product / INCI Name Functionality % w / w

[0208] Deionised Water Solvent To 100

[0209] Disodium EDTA (sodium dihydrogen Chelating Agent 0.20 ethy I enedi am i netetraacetate)

[0210] SLES (28%) (Sodium Lauryl Ether Sulphate) Surfactant 20.00

[0211] Sample A (Isostearamidoethyl Conditioning agent 3.00

[0212] Isostearylmethylimidazolinium Methosulfate

[0213] (and) Caprylic / Capric Triglyceride)

[0214] Cresmer™ HE (PEG-7-Glyceryl Cocoate)1Emollient 3.00

[0215] Crodateric™ CAB 30 (Cocamidopropyl Foam booster 10.00

[0216] Betaine)1

[0217] Versathix™ (PEG-150 pentaerythrityl Rheology Modifier 3.00 tetrastearate (and) PPG-2 hydroxyethyl cocam ide (and) water)1

[0218] Euxyl PE 9010 (Phenoxyethanol, Preservative 0.70

[0219] Ethylhexylglycerin)2

[0220] Suppliers: - 1 : Croda 2: Schulke & Mayr GmbH Procedure to make Formulation C: Pre-mix Cresmer™ HE and Sample A well. Weigh all the ingredients one by one in main beaker and keep it under stirring. Add the premix of Cresmer™ HE and Sample A in the main beaker, slowly under stirring. Add preservative and Versathix™ Stir for two minutes. Table 8 - properties of Formulation C

[0221] Formulation D - Hair Shampoo

[0222] Ingredient / INCI Name Functionality % w / w

[0223] Deionised Water Solvent To 100

[0224] Disodium EDTA Chelating Agent 0.20

[0225] Cresmer™ HE (PEG-7 Glyceryl Cocoate)1Emollient 3.00

[0226] Sample A (Isostearamidoethyl Conditioning Agent 3.00

[0227] Isostearylmethylimidazolinium Methosulfate

[0228] (and) Caprylic / Capric Triglyceride)

[0229] Crodasinic™ LS 30 (Aqua (and) Sodium Surfactant 25.00

[0230] Lauroyl Sarcosinate)1

[0231] Crodateric™ CAB 30 (Cocamidopropyl Foam Booster 20.00

[0232] Betaine)1

[0233] Adinol™ CT95 SD (Sodium Methyl Cocoyl Foam Booster 5.00

[0234] Taurate)1

[0235] Versathix™ (PEG- 150 pentaerythrityl Rheology Modifier 2.40 tetrastearate (and) PPG-2 hydroxyethyl cocam ide (and) water)1

[0236] Euxyl PE 9010 (Phenoxyethanol, Preservative 0.70

[0237] Ethylhexylglycerin)2

[0238] Suppliers: - 1 : Croda 2: Schulke & Mayr GmbH

[0239] Procedure to make Formulation D: Pre-Mix Cresmer™ HE and Sample A well. Weigh all the ingredients one by one in main beaker. And keep it under stirring. Add the premix of Cresmer™ HE& Sample A in the main beaker slowly under stirring. Add preservative and Versathix™ in it. Stir for two minutes.

[0240] Table 9 - properties of Formulation D

[0241] Formulation E - Hair Serum

[0242] Product / INCI Name Functionality % w / w

[0243] Sample A (Isostearamidoethyl Conditioning agent 3.00

[0244] Isostearylmethylimidazolinium Methosulfate (and)

[0245] Caprylic / Capric Triglyceride)

[0246] Coconut Oil (Cocos Nucifera Oil) Natural emollient 3.00

[0247] Crodamol™ ISIS (Isostearyl Isostearate)1Emollient 2.00

[0248] Crodamol™ GTCC (Caprylic / Capric Triglyceride)1Emollient 3.00

[0249] LexFeel™ WOW A DT (C13-15 Alkane (and) Heptyl Natural silicone 88.00

[0250] Undecylenate)3alternative

[0251] Cherry Ecocert2Fragrance 1.00

[0252] Suppliers: - 1 : Croda 2: Iberchem 3: Index Procedure to make Formulation E:

[0253] Simply weigh all the ingredients one by one. Stir it well.

[0254] Table 10 - properties of Formulation E

[0255] It is to be understood that the invention is not to be limited to the details of the above embodiments, which are described by way of example only. Many variations are possible.

Claims

Claims:

1. A personal care formulation comprising 0.1% to 15% by weight, based on the total weight of the formulation, of a di-alkyl imidazoline quaternary compound which comprises two alkyl groups which are independently selected from branched Ci2 to C19 alkyl groups.

2. A personal care formulation according to claim 1 wherein at least one of the alkyl groups is an isostearyl group.

3. A personal care formulation according to claim 1 or claim 2 wherein the di-alkyl imidazoline quaternary compound is an isostearamidoethyl-isostearylmethylimidazolinium.

4. A personal care formulation according to any preceding wherein the di-alkyl imidazoline quaternary compound is isostearamidoethyl-isostearylmethylimidazolinium methosulfate.

5. A personal care formulation according to any preceding claim further comprising 0.01 % to 10% by weight, based on the total weight of the formulation, of a diluent selected from triglycerides, mono-esters and di-esters.

6. A personal care formulation according to claim 5 wherein the diluent is a saturated or unsaturated triglyceride of C4 to C14 fatty acids.

7. A personal care formulation according to any preceding claim, wherein the personal care formulation is transparent, preferably measured as described herein.

8. A personal care formulation according to any preceding claim, further comprising a personal care ingredient selected from a cleaning agent, hair conditioning agent, hair styling agent, anti-dandruff agent, hair growth promoter, perfume, sunscreen, sunblock, pigment, moisturizer, film former, hair color, make-up agent, thickening agent, emulsifier, humectant, emollient, antiseptic agent, deodorant active, dermatologically acceptable carrier, surfactant, abrasive, absorbent, fragrance, colorant, essential oil, astringent, antiacne agent, anti-caking agent, anti-foaming agent, anti-oxidant, binder, enzyme, enzyme inhibitor, enzyme activator, coenzyme, botanical extract, ceramide, buffering agent, bulking agent, chelating agent, cosmetic biocide, external analgesic, substantivity increasing agent,opacifying agent, pH adjuster, reducing agent, sequestrant, skin bleaching and / or lightening agent, skin conditioning agent, skin soothing and / or healing agent, skin treating agent, vitamin or preservative.

9. A personal care formulation according to any preceding claim, wherein the personal care formulation is a topical hair care formulation.

10. A personal care formulation according to any preceding claim, further comprising a hair care ingredient selected from shine enhancers, moisturisers, herbal additives, hair strengtheners, vitamin additives, colorants, hair thickening agents; setting and styling agents; ultraviolet absorbers; silicone oils; essential oils and fragrances; thickening or viscosity-enhancing agents; detergents; surfactants; cleaning agents; stabilising agents; emollients; chelating agents; sequestering agents; preservatives; disinfectants; anti- oxidants / radical scavengers; antistatic agents; conditioning agents; detangling ingredients; emulsifying or dispersing agents.

11. A method of treating hair comprising the step of applying to hair a formulation comprising a di-alkyl imidazoline quaternary compound which comprises two alkyl groups which are independently selected from branched Ci2 to C19 alkyl groups.

12. A method according to claim 11, wherein the method comprises one or more steps selected from bleaching, colouring, straightening, perming, curling, relaxing, fixing, holding, shaping, styling, thermal treatment, cleaning or conditioning of the hair.

13. Use of a composition comprising a di-alkyl imidazoline quaternary compound which comprises two alkyl groups which are independently selected from branched Ci2to C19 alkyl groups, for the treatment of hair.

14. Use according to claim 13, wherein the treatment of hair comprises one or more steps selected from bleaching, colouring, straightening, perming, curling, relaxing, fixing, holding, shaping, styling, thermal treatment, cleaning or conditioning of the hair.

15. Use according to claim 13 or 14, wherein the treatment of hair improves at least one of smoothness, shine, wet-combing and / or dry combing of hair, preferably measured as described herein.

16. Use according to any of claims 13 to 15, wherein the use of a composition comprising at least 3% by weight of the di-alkyl imidazoline quaternary compound, based on the total weight of the composition, provides a reduction in the wet-combing force for the hair when compared with a control, preferably measured as described herein.

17. Use according to any of claims 13 to 16, wherein the use of a composition comprising at least 3% by weight of the di-alkyl imidazoline quaternary compound, based on the total weight of the composition, provides a reduction in the dry-combing force for the hair when compared with a control, preferably measured as described herein.

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