WO2004028676A1

WO2004028676A1 - Opacificiers

Info

Publication number: WO2004028676A1
Application number: PCT/EP2003/009865
Authority: WO
Inventors: Kevan Hatchman
Original assignee: Huntsman International Llc
Priority date: 2002-09-26
Filing date: 2003-09-05
Publication date: 2004-04-08
Also published as: AU2003271584A1

Abstract

The invention provides (A) an aqueous amphoteric-based opacifier (e.g. pearl concentrate), which comprises: water; a mixture of glycol stearates comprising from 2 to 15%, by weight, based on the total weight of the suspension, of ethylene glycol monostearate and from 15 to 36%, by weight, based on the total weight of the suspension, of ethylene glycol distearate; from 12 to 25% by weight of amphoteric surfactant; less than 15%, by weight, based on the weight of the amphoteric surfactant, of electrolyte; and from 0 to 10%, by weight, of nonionic or anionic surfactant, and (B) according to a further embodiment, a 'two component' opacifier, which comprises: water; a mixture of glycol stearates comprising from 2 to 12%, by weight, based on the total weight of the suspension, of ethylene glycol monostearate and from 15 to 36%, by weight, based on the total weight of the suspension, of ethylene glycol distearate; from 12 to 25% by weight of a single surfactant selected from anionic, non-ionic, amphoteric and cationic surfactants; from 0.1 to 2% total of a non-ionic or anionic deflocculant having a hydrophilic group with a mass of at least 100 amu and having an HLB greater than 12, and/or a non-ionic dispersant having an HLB of 1.5 to 10.

Description

OPACIFIERS

This invention relates to opacifiers, which can be suspended in liquids to provide an opaque, creamy, visual effect and conceal inhomogeneities. The invention, in its preferred embodiment, relates to pearlisers, which are a species of opacifier, which typically comprise small, thin, transparent platelet crystals, and which can be suspended in a parallel configuration. When so suspended, light falling on the crystals undergoes complex multiple reflections within the substrate, similar to those which occur in a pearl and gives rise to similar optical interference effects.

Natural pearls comprise alternate layers of calcium carbonate and protein. Artificial pearlisers include guanine/hypoxanthine crystals extracted from fish scales, mica, various salts of lead, zinc, mercury and bismuth (e.g. bismuth oxychloride), titanium oxide and various fatty acid derivatives such as magnesium stearate, coconut monoethanolamide, ethylene glycol distearate , ethylene glycol monostearate and polyethyleneglycol stearates. Fish scale extracts are too expensive and the inorganic pearlisers are either too toxic for general use in toiletries e.g. lead, mercury, or relatively ineffective e.g. bismuth. The fatty acid derivatives are therefore now the most widely used pearlisers. Commercial glycol stearate pearlisers all comprise mixtures of ethylene glycol mono stearate (EGMS) and ethylene glycol distearate (EGDS) in varying proportions.

In addition to the chemical nature and physical form of the pearliser the manner in which it is suspended has an important effect on its visual impact. Difficulty is sometimes encountered obtaining the desired effect when incorporating pearlisers into aqueous formulations.

Conventional fatty acid derived pearlisers are supplied as solids, which are usually added to a heated formulation above their melting point and recrystallised in situ. The conditions of crystallisation and especially the amount and nature of the agitation applied must be carefully controlled in order to obtain an acceptable result. This makes it difficult to obtain consistent effects and renders solid pearlisers inconvenient to use. Attempts have been made to prepare liquid concentrates or suspensions, which can be added directly to shampoo formulations without heating. While more convenient for the user, such concentrates face the manufacturer with problems of obtaining a high and consistent pearl effect, similar to those which confront the user of conventional solid pearlisers. Difficulty is also encountered in maintaining the particles in stable suspension and preventing sedimentation.

For many users, a major concern has been the cocktail of surfactants, often used to make such concentrates. There is a demand for products containing only a single surfactant, which, preferably, will be one, which is already intrinsic to, or at least fully compatible with, the customer's intended formulation. Generally, formulators want to avoid using pearl concentrates, which contain surfactants that are extraneous to the end formulation.

Commercial products addressing the above problems, based on the teaching, for example, of WO 01 / 25378, have required the use of anionic surfactants, such as alkyl ether sulphates. However, for many potential applications, the presence of anionic surfactants is unacceptable or undesirable.

It has been proposed to suspend glycol stearates in non- ionic surfactants. However, many formulations cannot tolerate the addition of significant levels of either anionic or non-ionic surfactant. There is a need for a suspension of opacifier containing amphoteric surfactant, preferably as the sole surfactant species, or optionally with no more than minor amounts of anionic or non-ionic surfactants. It is an object of the invention to satisfy that need.

Current commercial pearl concentrates, whether anionic or non-ionic, contain undesirably low levels of opacifier, e.g., typically, in the range 15 to 25%, by weight. Higher levels usually give unacceptably high viscosities. It is therefore a further object of the present invention to provide pourable suspensions containing higher levels of glycol stearates, and especially levels greater than 30%, by weight. Unfortunately, aqueous mixtures of amphoteric surfactants and economically acceptable levels of glycol stearates tend to be either too viscous, or unstable to be commercially acceptable, and to thicken to an intractable paste, on storage under warm conditions.

We have now discovered that it is possible to suspend commercially viable concentrations of glycol stearate in amphoteric surfactant, by keeping electrolyte levels low, and/or by including small amounts of non-ionic or anionic deflocculants and/ or non-ionic dispersants. In particular, we have succeeded in making pourable suspensions containing more than 30% by weight glycol stearates, e.g. up to 40% or more.

We have also discovered it is possible to use deflocculants and/ or dispersants to enhance the pourability of other single surfactant opacifier suspensions, especially at high opacifier loading, at concentrations which do not compromise their acceptability as single surfactant formulations. The term "single surfactant", in this context does not, of course, exclude surfactants, which are mixtures of homologues.

Our invention provides an aqueous glycol stearate suspension, which comprises: water; a mixture of glycol stearates comprising from 2 to 15%, by weight, based on the total weight of the suspension, of ethylene glycol monostearate and from 15 to 36%, by weight, based on the total weight of the suspension, of ethylene glycol distearate; from 12 to 25% by weight of amphoteric surfactant; less than 15%, by weight, based on the weight of the amphoteric surfactant, of electrolyte; and from 0 to 10%, by weight, of non-ionic or anionic sufactant.

According to a further embodiment our invention provides an aqueous glycol stearate suspension, which comprises: water; a mixture of glycol stearates comprising from 2 to 12%, by weight, based on the total weight of the suspension, of ethylene glycol monostearate and from 15 to 36%, by weight, based on the total weight of the suspension, of ethylene glycol distearate; from 12 to 25% by weight of a single surfactant selected from anionic, non-ionic, amphoteric and cationic surfactants; from 0.1 to 2% total of a non-ionic or anionic deflocculant having a hydrophilic group with a mass of at least 100 amu and having an HLB greater than 12, and/or a non-ionic dispersant having an HLB of 1.5 to 10.

In the following discussion of the invention, unless stated to the contrary, the disclosure of alternative values for the upper or lower limit of the permitted range of a parameter, coupled with an indication that one of said values is more highly preferred than the other, is to be construed as an implied statement that each intermediate value of said parameter, lying between the more preferred and the less preferred of said alternatives, is itself preferred to said less preferred value and also to each value lying between said less preferred value and said intermediate value.

The EGDS is preferably present in a proportion of more than 16%, more preferably more than 17%, even more preferably more than 20% by weight, most preferably more than 25%, but preferably less than 38%, more preferably less than 34%, even more preferably less than 32%, most preferably, less than 30%. The amount of EGMS is critical, if a good pearl effect is required. It is preferably less than 13%, more preferably less than 12%, even more preferably less than 10%, most preferably less than 8%, by weight, based on the weight of the suspension, and, for best mobility combined with a good pearl effect, it is preferred to include at least 4%, more preferably at least 5%, most preferably more than 5.5%, by weight of the suspension.

Preferably the weight ratio of glycol stearate to surfactant is greater than 1:1, more preferably greater than 1.3:1, even more preferably greater than 1.5:1, yet more preferably greater than 1.6:1, more preferably still, 1.7:1 most preferably greater than 1.8:1, but preferably less than 2.7:1, more preferably less than 2.5:1, even more preferably less than 2.4:1, more preferably still, less than 2.3:1, most preferably less than 2.2:1. The total weight % of glycol stearates is preferably greater than 20%, by weight, more preferably greater than 25%, even more preferably greater 28%, more preferably still, greater 30%, most preferably greater than 32%. Generally, in order to avoid excessive viscosity, we prefer that the total concentration of glycol stearates should be less than 50%), more preferably less than 45%, even more preferably less than 42%, more preferably still, less than 40%>, most preferably less than 38%, by weight, based on the total weight of the composition.

"Amphoteric surfactant" is used herein in its usual sense in the art, to include zwitterionic surfactants. For convenience, the term "amphoteric surfactant" also includes amine oxides.

The commonest amphoteric surfactants are betaines, which are made by reacting sodium chloracetate with an amine. The reaction forms sodium chloride as an equimolar by-product. Betaines therefore contain about 20%) by weight of salt based on the weight of surfactant. Phosphobetaines, sulphobetaines and amphoacetates are made by analogous reactions, and also contain salt in similar amounts. The amino propionates are made by reacting amines with acrylic acid, and contain no salt.

We have found that amphoterics containing low levels of salt, preferably betaines, from which the salt has been removed, are capable of suspending glycol stearate more readily than conventional amphoterics. We prefer that the amount of salt should be less than 10%, more preferably less than 5%, even more preferably less than 3%, more preferably still, less than 1%, most preferably less than 0.5%), by weight, based on the weight of amphoteric surfactant.

Salt may be removed from amphoteric surfactants, either by electrosmosis, e.g. as described in our GB 1 525 692 or in EP 0 736 521, or by membrane filtration, for example as described in EP 0 626 881. We prefer that the above limits for salt content should apply to total electrolyte content and not only to sodium chloride. Typically the amphoteric surfactant is derived from an amine, which has one aliphatic substituent with more than 7, preferably more than 10, most preferably more than 13 carbon atoms which is a long chain, hydrophobic substituent wherein the chain is formed of carbon and hydrogen atoms, optionally with one or more nitrogen and/or oxygen atoms and/or, less commonly, one or more sulphur and/or phosphorus atoms. The expression "long chain" means having more than 7 atoms and preferably more than 12 atoms linearly arranged, i.e. excluding any branching, which may be present. The amine may also have up to two short chain aliphatic substituents each having less than five carbon atoms in total. The short chains may for example be, or comprise methyl, ethyl, hydroxyethyl, propyl or butyl groups, the long chains are typically octyl, octyl amido propyl, decyl, decyl amido propyl, lauryl, lauryl amido propyl, tetradecyl amido propyl, tetradecyl, myristyl, myristyl amido propyl, palmityl amido propyl, palmityl, stearyl amido propyl, stearyl, behenyl, oleyl amido propyl, oleyl, linoleyl, linolenyl, erucyl amido propyl or erucyl. The chain may optionally include one or more ether, ester or keto groups, e.g. polyoxypropylene.

Mixtures comprising the foregoing, and especially mixtures derived from natural oils or fats are generally preferred. The most preferred betaine is coconut amido propyl betaine commonly know as CAPB. The term CAPB is normally used generically to include amido propyl betaines made from coconut oil feedstocks and also from other feedstocks, natural or synthetic with a similar distribution of homologues, e.g. palm oil. CAPB comprises C₁₂ amido propyl betaine as its principal constituent with smaller amounts of the C₈, C₁₀, C₁ , C_16. and C₁₈ alkyl and oleyl homologues.

The surfactants for use according to our invention typically have the formula :

(R')n

R-N n+ (CH₂)_m XT

R² Wherein : R is the aliphatic group containing more than 7 carbon atoms; R¹ and R² are each, independently, hydrogen or an ethyl, hydroxyethyl or most preferably a methyl group; m is 1 or 2; X is a phosphono, sulphono, or, preferably, carboxy group; and n is 0 or, preferably, 1.

R preferably has from 12 to 25 carbon atoms and is desirably a straight chain alkyl or alkyl amido alkylene group, especially a group of the formula CH₃(CH₂)_aCONH(CH₂)_b where (a+b) is from 12 to 23 and b is preferably 2 or most preferably 3.

Products derived from unsaturated feedstocks, or from synthetic feedstocks, which are usually branched chain, and/or which may comprise an odd number of carbon atoms, or products with hydroxyl groups, such as alkyl (bis 2-hydroxyethyl) betaines may be used.

The surfactant may comprise a so-called quaternary imidazoline betaines, which are also called ampho acetates, and traditionally ascribed the formula : CH₂ CH₂

N sr — CH₂coo^_

\

R¹

R because they are obtained by reacting sodium chloroacetate with an imidazoline. It has been shown, however, that, they are actually present, at least predominantly, as the corresponding linear amido amine

RCONH CH₂ CH₂ N^"1" R¹

CH₂COO^" Which is usually obtained commercially in admixture with the dicarboxymethylated form:

RCON1H CH₂ CH₂ N⁺ R¹

CH₂COO^" CH₂COO^"

When using amphoacetate as the amphoteric surfactant according to the invention it is preferred that the pH be acid to neutral, e.g. less than 7.5, more preferably less than 7, most preferably less than 6.5, but desirably more than 4, preferably more than 4.5, most preferably more than 5.

Amine oxides, including amido amine oxides, behave in an analogous manner to zwitterionic surfactants, and are therefore included under the heading of amphoteric surfactants, for the purpose of this invention. They are preferably represented by the formula: RR^N* — O^", where R is an aliphatic group having from 8 to 25 carbon atoms, such as an alkyl, alkenyl or alkylamido propyl group, and each of R¹ and R² is a C alkyl or hydroxy alkyl group and preferably a methyl or ethyl group. It is also possible for two or more of R, R¹ and R², in the last foregoing formula, to be joined as part of a single or multiple ring system, such as N-alkyl pyrrolidine oxides or N-alkyl piperazine oxides. The N- alkyl group may be a fatty alkyl, e.g. N-lauryl pyrrolidine oxide, or a C).₄ alkyl, the fatty alkyl group being substituted elsewhere on the ring, e.g. N-methy 1-3 -stearyl pyrrolidine oxide.

To avoid introducing excessive amounts of water and electrolyte to the system we prefer to use desalted or low salt, and at least partially dehydrated, e.g. vacuum or freeze dried, amphoterics. In particular we prefer to use non-deliquescent, substantially anhydrous amphoteric surfactants, such as dried, desalted LAPB, or any of the dried products described and claimed in WO 02/22552. Compositions of the invention, according to its second embodiment may contain an anionic surfactant, as the single surfactant. The anionic surfactant may, preferably, comprise an alkyl ether sulphate which is preferably the product obtained by ethoxylating a natural fatty or synthetic C1₀-₂₀ e.g. a C₁₂.₁₄ alcohol with from 1 to 20, preferably 2 to 10 e.g. 3 to 4 ethyleneoxy groups, optionally stripping any unreacted alcohol, reacting the ethoxylated product with a sulphating agent and neutralising the resulting alkyl ether sulphuric acid with a base. The ether sulphate may alternatively be an alkyl glyceryl sulphate, or a random or block copolymerised alkyl ethoxy/ propoxy sulphate.

The anionic surfactant may also be, for example, a C₁₀-₂₀ (e.g. C₁₂.₁ ) alkyl sulphate, a Cιo-₂o alkyl benzene sulphonate or a C₈-₂₀ (e.g. C_JO-_IS) aliphatic soap. The soap may be saturated or unsaturated, straight or branched chain. Preferred examples include dodecanoates, myristates, stearates, oleates, linoleates, linolenates, behenates, erucates and palmitates and coconut and tallow soaps. The surfactant may also include other anionic surfactants, such as olefm sulphonates, paraffin sulphonates, taurides, isethionates, ether sulphonates, ether carboxylates, sarcosinates, aliphatic ester sulphonates e.g. alkyl glyceryl sulphonates, sulphosuccinates or sulphosuccinamates.

The cation of any anionic surfactant is typically sodium but may alternatively be potassium, lithium, calcium, magnesium, ammonium, or an alkyl ammonium having up to 6 aliphatic carbon atoms including ethylammonium, isopropylammonium, monoethanolammonium, diethanolammonium, and triethanolammonium.Ammonium and ethanolammonium salts are generally more soluble than the sodium salts. Mixtures of the above cations may be used.

The single surfactant may be a non-ionic surfactant, which may typically comprise a polyglyceryl fatty ester, fatty acid ethoxylate, fatty acid monoalkylolamide, fatty acid dialkylolamide, fatty acid alkylolamide ethoxylate, propylene glycol monoester, fatty alcohol propoxylate, alcohol ethoxylate, alkyl phenol ethoxylate, fatty amine alkoxylate, fatty acid glyceryl ester ethoxylate, mixed ethylene oxide propylene oxide block copolymer, ethylene glycol monoester, alkyl polyglycoside, alkyl sugar ester (preferably an alkyl sucrose ester), alkyl oligosaccharide ester, sorbitan ester, ethoxylated sorbitan ester, alkyl capped polyvinyl alcohol or alkyl capped polyvinyl pyrrolidone.

For optimum viscosity, it is often desirable to include a non-ionic or anionic deflocculant. The latter may comprise one or two fatty alkyl or alkenyl groups linked to a large (e.g. more than lOOamu, preferably more than 200, more preferably more than 300, even more preferably more than 400, yet more preferably more than 500, most preferably more than 600amu) non-ionic or anionic hydrophilic group.

Examples include alkyl polyglycosides, polyglyceryl esters, sorbitan esters, polyethylene glycol esters, thiol polyacrylates, alkyl polyethoxylates and sucrose esters. We generally prefer that the deflocculant has an HLB greater than 12, more preferably greater than 13, even more preferably greater than 14, most preferably greater than 15.

Additionally or alternatively to the deflocculant, the composition may contain a non- ionic dispersant, which has an HLB below 10, preferably below 8, more preferably below 7, even more preferably below 6, most preferably below 5, but above 1.1 preferably above 1.5, more preferably above 2, still more preferably above 3, most preferably above 4. Examples of suitable dispersants include glyceryl and poly (e.g. 2 to 5, preferably 3 to 4 mole) glyceryl esters, especially of one or preferably more fatty acids, such as stearic, oleic, erucic or isostearic acid. Polyglyceryl esters of dimerised unsaturated fatty acids, such as dimerised linoleic acid, and their (preferably longer chain, i.e. C₁ .₂ ) fatty acid derivatives, such as diisostearoyl polyglyceryl-3 dimer dilinoleate, are particularly preferred. Also of use as dispersants are sorbitan mono or preferably di-esters of (preferably longer chain) fatty acids. The deflocculant and/or the dispersant are each typically present in a concentration of less than 5%, by weight, preferably less than 4%, more preferably less than 3%, even more preferably less than 2%, yet more preferably less than 1%, more preferably still, less than 0.5%, most preferably less than 0.3%, by weight, based on the weight of the suspension. Preferably the total concentration of deflocculant and dispersant is less than 5%, more preferably less than 4%, even more preferably less than 2%, more preferably still, less than 1%, most preferably less than 0.5%.

Effective deflocculation/ dispersion usually requires more than 0.01%, preferably more than 0.05%, most preferably more than 0.1%, by weight of deflocculant/ dispersant.

The aqueous medium may additionally comprise a preservative. Solvents are preferably absent, but may sometimes be used in small quantities to improve mobility. For example, alcohols such as ethanol or isopropanol, glycols such as ethylene or propylene glycol, glycerol, polyethylene glycols and glycol ethers may be present, sometimes in concentrations as high as 10% by weight, but preferably less than 5%, more preferably less than 2%, most preferably less than 1%. Hydrotropes, such as urea, or toluene-, cumene- or xylene- sulphonates are not normally needed, but could be added in amounts up to about 5% by weight, e.g. 0.1 to 2%, if desired. It is also possible to suspend other solids, e.g. polyethylene glycol distearates or other co- opacifiers or pearlisers, in addition to the ethylene glycol stearates.

In principle the suspensions of the invention can contain any chemically compatible ingredient that may be required or tolerated in the customer's formulation, however, we strongly prefer to include only the minimum number of essential ingredients, so as to give the customer maximum flexibility. In general these essential ingredients are water, a single surfactant and glycol stearates, together, usually, with amounts of deflocculant, dispersant and/or preservative, which are too small to affect the end user's formulation, or to require separate listing. The suspensions of the invention are preferably made by mixing the ingredients at, or raising a mixture of the ingredients to, a temperature above the melting point of the EGDS, e.g. above 60°C, preferably above 70°C, typically 80 to 90°C, stirring the mixture to disperse the molten wax and cooling to re-crystallise the wax. In general, where a good pearl effect is required, we prefer to cool the mixture slowly, e.g. less than 0.5°C per minute, preferably less than 0.2°C, especially between 0.15 and 0.01°C per minute. In particular we prefer to cool most slowly at, and just below, the temperature at which the glycol stearate crystalises. We particularly prefer to hold the mixture at a temperature slightly below the crystalisation temperature, e.g. between 55and 60°C, for from 1 to 4 hours

The invention will be illustrated by the following examples, in which all proportions are percentages by weight of active ingredient, based on the total weight of the composition, unless stated to the contrary:

EXAMPLE I

A mixture of:

Desalted aqueous CAPB (36% active, 0.2% NaCl) 51.4%

EGDS 28.1%

EGMS 5.9%

Polyglyceryl -3 oleate 0.25%

Preservative "KATHON" CG (RTM) 0.1%

Water balance was heated to 85° with stirring to disperse the molten wax. The mixture was cooled, with further stirring, at a rate of 0.1 °C per minute, to a temperature of58°C. After 1.5 hours stirring at 55-58°C, the mixture was cooled to 30°C, at a rate of 0.05°C per minute. A stable, mobile pearl concentrate was obtained. EXAMPLES II and III

A non-ionic pearl concentrate was found to have a viscosity greater than 12Pas (Brookfield RNT/S4/10rpm/30sec@20°C). This was commercially unacceptable. Addition of deflocculants substantially reduced the viscosity as shown in the following table:

1. APG is an alkyl polyglucoside sold under theRegistered Trade Mark "GLUCAPOΝ" 215 CS

2. XB 16 is a C₁₂.₁ thiol polyacrylate sold under theRegistered Trade Mark "BENALOID" XB16

It will be understood that the opacifying waxes for use in this invention could comprise, or consist of glycol ester waxes, such as mono- or di-esters of ethylene glycol with C₁₄-₂₄ fatty acids, which are equivalent to ethylene glycol mono- and di- stearates respectively. As used herein, the terms "glycol stearate", "ethylene glycol monostearate", "EGMS", "ethylene glycol distearate" and "EGDS" are to be construed as embracing such equivalents wherever the context permits.

Claims

1. An aqueous glycol stearate suspension, which comprises: water; a mixture of glycol stearates comprising from 2 to 15%, by weight, based on the total weight of the suspension, of ethylene glycol monostearate and from 15 to 36%), by weight, based on the total weight of the suspension, of ethylene glycol distearate; from 12 to 25 % by weight of amphoteric surfactant; less than 15%, by weight, based on the weight of the amphoteric surfactant, of electrolyte; and from 0 to 10%, by weight, of non-ionic or anionic surfactant.

2. An aqueous glycol stearate suspension, which comprises: water; a mixture of glycol stearates comprising from 2 to 12%, by weight, based on the total weight of the suspension, of ethylene glycol monostearate and from 15 to 36%, by weight, based on the total weight of the suspension, of ethylene glycol distearate; from 12 to 25% by weight of a single surfactant selected from anionic, non-ionic, amphoteric and cationic surfactants; from 0.1 to 2% total of a non-ionic or anionic deflocculant having a hydrophilic group with a mass of at least 100 amu and having an HLB greater than 12, and/or a non- ionic dispersant having an HLB of 1.5 to 10.

3. A composition according to either of claims 1 and 2, wherein the EGDS is present in a proportion of more than 20% by weight.

4. A composition according to any foregoing claim, wherein the proportion of EGDS is less than 38% by weight.

5. A composition according to any foregoing claim wherein the amount of EGMS is less than 10% by weight.

6. A composition according to any foregoing claim wherein the amount of EGMS is greater than 4% by weight.

7. A composition according to any foregoing claim wherein the weight ratio of glycol stearate to surfactant is greater than 1:1.

8. A composition according to claim 7, wherein the weight ratio of glycol stearate to surfactant is more than 1.7:1.

9. A composition according to any foregoing claim wherein the weight ratio of glycol stearate to surfactant is less than 2.7:1.

10. A composition according to any foregoing claim, comprising a non-ionic or anionic deflocculant, having one or two fatty alkyl or alkenyl groups linked to a more than lOOamu non-ionic or anionic hydrophilic group.

11. A composition according to any foregoing claim comprising a non-ionic dispersant, which has an HLB below 10.

12. A composition according to claim 11, wherein said dispersant has an HLB below 7.

13. A composition according to any of claims 10 to 12, wherein the deflocculant and the dispersant are each present in a concentration of less than 5%, by weight.

14. A composition according to claim 13, wherein the deflocculant and the dispersant are each present in a concentration from 0.1 to 0.5% by weight.

15. A method for the manufacture of a composition according to any foregoing claim, which comprises mixing the ingredients at, or raising a mixture of the ingredients to, a temperature above the melting point of the EGDS, stirring the mixture to disperse the molten wax and cooling to re-crystallise the wax.