WO2007060434A1

WO2007060434A1 - Emulsions

Info

Publication number: WO2007060434A1
Application number: PCT/GB2006/004380
Authority: WO
Inventors: Hanamanthasa Shankarsa Bevinakatti; Emmanuelle Juan
Original assignee: Croda International Plc
Priority date: 2005-11-25
Filing date: 2006-11-24
Publication date: 2007-05-31
Also published as: GB0524022D0

Abstract

Oil in water emulsions include as emulsifiers, surfactant compounds which are long chain fatty mono- or di-ureas having an oligosaccharide residue substituted on a urea nitrogen atom, particularly compounds of the formula (I): H-[S]n-Sj-N(R1)-C(O)-NHR2 where S, n, Sj, R1, and R2 have defined meanings, and which are relatively hydrophilic emulsifiers typically having HLB values in the range 10 to 20 and are useful especially for personal care or agrochemical emulsion products, particularly those requiring electrolyte tolerance. Compounds of the formulae I(b) H-[S]n-Sj-[C(O)-NH-R2b]-N-R1b-N-[R2bHN(O)C]-Sj-[S]n-H (Ib); and I(c) H-[S]n-Sj-N(R1c)-C(O)-NH-R2c-NH-C(O)-N(R1c)Sj-[S]n-H (Ic); where each S, n, Sj, R1b, R1c, R2b and R2c have defined meanings, are part of the invention as such.

Description

Emulsions

This invention relates to emulsions and in particular to emulsions including emulsifier surfactants having a hydrophile which is the residue of a saccharide, particularly an oligomeric saccharide.

Oil in water emulsions are used very widely in many products, notably, but not exclusively in personal care products e.g. milk and cream type personal care formulations. Commonly the emulsifiers used in making such emulsions have included hydrophiles based on petrochemical feedstocks including alkylene oxides particularly ethylene oxide. In recent years there has been a move towards developing surfactants based on renewable feedstocks.

Sugar based surfactants have been available for many years and commercially available materials include the sorbitan esters sold under the Trademark "Span", which are low HLB surfactants and their higher HLB ethoxylated sorbitan esters derivatives sold under the Trademark "Tween". Sorbitol and sucrose esters are available, but are generally relatively expensive and are often broad mixtures including monoesters, diesters and higher esters. Dextrins have been used as starting materials for making surfactants in particular by forming fatty carbamates by reaction with fatty isocyanates for example as described in WO 01/44303 A and WO 03/031043 A. Such products typically include more than one fatty chain per dextrin molecule and can thus be considered branched. This may adversely affect oil in water emulsification properties and the presence of additional fatty chains combined with the fact that the reactions consume hydroxyl groups will make the products less hydrophilic and this may limit their applicability. The present invention is based on our finding that ureas derived from saccharide and dextrin amine derivatives (Schiff bases - see below) are highly effective oil in water emulsifiers having high HLB values. The compounds that we have found useful in this regard include saccharide and dextrin ureas which are known from US 4737488 which describes the compounds as immune system promoters, but says nothing about any useful surfactant properties of the materials. The present invention accordingly provides oil in water emulsions which include as an emulsifier at least one surfactant compound which is a long chain fatty mono-or di-urea including at least one oligosaccharide residue substituted on a urea nitrogen atom.

The surfactant compounds used in the invention are particularly of the formula (I):

H-[S]_n-Sj-N(R¹J-C(O)-NHR² (I) where each S is the residue of monosaccharide; n is an average value of from 0 to 50, particularly 2 to 20; Sj is a deoxy residue of a reducing monosaccharide residue; and R¹ is a Cj to C22 hydrocarbyl or hydroxyhydrocarbyl group; or R¹ is a group of the formula: -R^{1 b}-NH(C(O)-NR^2b)-Sj-[S]_n-H; where each S, n, and Sj is independently as defined above; where

R^{1 b} is a C2 to C22 hydrocarbylene group; and

R^2b is C-i to C22 hydrocarbyl group; or R² is a C-j to C22 hydrocarbyl group; or R² is a group of the formula: -R^2c-NH-(O)C-N(R^{1 c})-Sj-[S]_n-H; where each S, n, and Sj is independently as defined above;

R^1c is C-] to C22 hydrocarbyl or hydroxyhydrocarbyl group; and

R^2c is a C2 to C22 hydrocarbylene group, and wherein at least one of R¹ (when it is a hydrocarbyl group), R^{1 D} and R^{1 c} (when present), R² (when it is a hydrocarbyl group) and R^2b and R^2c (when present) is a Ce to C22 group.

Among the compounds used as surfactants in the invention and in particular within the general formula (I) there are three subclasses of compounds whose use form separate aspects of the invention. The invention accordingly includes emulsions in which the surfactant includes compounds of each of the formulae (Ia), (Ib) and (Ic) as follows: Formula (Ia):

H-[S]_n-Sj-N(R^{1 a})-C(O)-NHR^2a (Ia) where each S, n and Sj is independently as defined for formula (I);

R^{1 a} is a Ci to C22 hydrocarbyl or hydroxyhydrocarbyl group; and R^2a is a C^ to C22 hydrocarbyl group, and wherein at least one of R^{1 a} and R^2a is a Ce to C22 group.

Formula (Ib):

R^2bHN(O)C C(O)-NH-R^2b H-[S]_n-Sj-N-R^{1 b}-N-Sj-[S]_n-H (Ib) where each S, n, Sj, R^{1 D} and R^2b is independently as defined for formula (I); and wherein at least one of groups R^{1 b} and R^2b is a C3 to C22 group.

Formula (Ic): H-[S]_n-Sj-N(R^{1 c})-C(O)-NH-R^2c-NH-C(O)-N(R^{1 c})Sj-[S]_n-H (Ic) where each S, n, Sj, R^{1 c} and R^2c is independently as defined for formula (I); and wherein at least one of R^1c, and R^2c is a Ce to C22 group.

The invention further includes the use of long chain fatty mono-or di-ureas including at least one oligosaccharide residue substituted on a urea nitrogen atom, particularly of the formulae (I), (Ia), (Ib) and/or (Ic) as emulsifiers for oil in water emulsions. The compounds of the formulae (Ib) and l(c) are novel as such and these compounds are part of the invention which accordingly includes compounds of each of the formulae (Ib) and (Ic) as set out above.

The compounds of and used in the invention include saccharide or oligosaccharide groups, in particular in compounds of the formula (I) the group: H-[S]_n-Sj-, corresponds to the residue of a saccharide or oligosaccharide, particularly an oligosaccharide, having a terminal residue (Sj) derived from a reducing saccharide. Suitable oligosaccharides include oligodextroses (oligoglucoses), and oligofructoses such as inulins (glyucosyl terminated oligofructoses). Among oligodextroses, dextrins are particularly useful and especially dextrins derived from starch. Desirably the index n is at least 2, more usually at least 3 and is typically from 5 to 20. The index n is an average value and thus may be non-integral. Where the oligosaccharide is an oligodextrose its degree of polymerisation (and thus its molecular weight) may be described by the Dextrose Equivalent (DE) of the oligosaccharide. DE measures the relative reducing power of a saccharide compared to dextrose expressed as the amount (in grams) of dextrose equivalent to 100 grams of the saccharide. So a DE of 5 indicates that 100 g of the saccharide has the same reducing power as 5 g glucose and for an oligoglucose would indicate a degree of polymerisation of about 20. Suitable ranges of DE for materials which can be used as starting materials to make compounds of and used in this invention are from 1 to 50, particularly 2 to 20 and especially from 5 to 20.

Generally where there is more than one oligosaccharide chain in the compounds of and used in the invention, as in compounds of the formulae (Ib) and (Ic) above, they will be the same as each other (allowing for molecular weight variations within the starting material). However, if desired, the oligosaccharide chains may differ from each other, desirably within the ranges stated above. The use of mixed oligosaccharide chains will generally give a mixture of products with "aa", "ab" and "bb" type products. The compounds of and used in the invention include hydrocarbyl and/or hydrocarbylene chains and at least one of these is a long chain fatty group, particularly a CQ to C22 hydrocarbyl or hydrocarbylene group. Specifically in compounds of the formula (I) the groups R¹, R-* ^a, R^{1 c}, R², R^2a and R^⁰ are or may be hydrocarbyl groups and the groups R^ ^ and R^2c are or may be hydrocarbylene groups. To provide the hydrophobicity necessary to give the desired surfactant properties at least one such group is a Cs to C22 hydrocarbyl or hydrocarbylene group. Desirably at least one such group is a C-JQ to C22. particularly a Cj4 to C20. and especially a C^ to C20. hydrocarbyl or hydrocarbylene group. There may be a plurality of long chain hydrocarbyl or hydrocarbylene groups in the molecule, but this is not usually necessary and may add to the complexity of synthesis. The groups R¹ , R^{1 a} and R^ ^c may be hydroxyhydrocarbyl and when such groups are present, they will generally be used to provide a modest amount of further hydrophilicity so they will generally be relatively short chain groups, in particular C2 to CQ, particularly C2 to C4, hydroxyhydrocarbyl groups e.g. 2-hydroxyethyl or 2- or 3-hydroxypropyl groups. As those skilled in the art will appreciate, the various R¹ and R² groups, particularly when they are fatty groups, are likely to be used as commercially available technical products which are derived from natural products and/or distillation cuts and will thus typically be mixtures of compounds (usually homologues) corresponding approximately, at least on average, to the nominal chain length.

In compounds of the formulae (Ib) and (Ic) the hydrocarbyl groups may be such as to provide symmetric or asymmetric substitution and as for the oligosaccharide chains, "mixed" hydrocarbyl groups will usually give mixtures of "aa", "ab" and "bb" substitution patterns in the products.

The compounds of and used in the invention can be synthesised using generally conventional reaction steps. Thus, compounds of the formula (I) can be made by reacting a precursor amine (Schiff base of a reducing oligosaccharide) with a corresponding isocyanate. Within the general range of formula (I) synthesis of compounds within the sub-classes (Ia), (Ib) and (Ic) can be carried out as follows:

Compounds of the formula (Ia) can be made by reacting one mole of a precursor amine of the formula (Ha):

H-[S]_n-Sj-N(RIa)H (Ha) with one mole of an isocyanate of the formula (Ilia):

OCN-R^2a (Ilia) where each S, n, Sj₁ R^{1 a} and R^2a is as defined for formula (Ia) above. The intermediate amine of the formula (Ha) can be made by reacting one mole of a reducing oligosaccharide of the formula (IV): H-[S]_n-Sj-OH (IV) where each S and n is as defined for formula (I) above, and Sj', is the residue of a reducing monosaccharide, with one mole of an amine of the formula (Va):

R^{1 a}NH₂ (Va) where R^{1 a} is as defined above for formula (Ia).

Compounds of the formula (Ib) can be made by reacting one mole of a precursor amine of the formula (lib): H-[S]_n-Sj-NH-R^{1 b}-NH-Sj-[S]_n-H (lib) with two moles of an isocyanate of the formula (HIb):

OCN-R^2b (HIb) where each S, n, Sj₁ R¹ *> and R^2D is as defined for formula (Ib) above.

The intermediate amine of the formula (lib) can be made by reacting two moles of a reducing oligosaccharide of the formula (IV): H-[S]_n-Sj-OH (IV) where each S and n is as defined for formula (I) above, and S-,>, is the residue of a reducing monosaccharide, with one mole of an amine of the formula (Vb):

H₂N-R^{1 b}-NH₂ (Vb) where R^{1 b} is as defined above for formula (Ib).

Compounds of the formula (Ic) can be made by reacting two moles of a precursor amine of the formula (lie):

H-[S]_n-Sj-N(RiC)H (lie) with one mole of an isocyanate of the formula (IHc): OCN-R²⁰NCO (lllc) where each S, n, Sj, R^1c and R^2c is as defined above for formula (Ic).

The intermediate amine of the formula (lie) can be made by reacting one mole of a reducing oligosaccharide of the formula (IV):

H-[S]_n-Sj-OH (IV) where each S and n is as defined for formula (I) above, and Sv, is the residue of a reducing monosaccharide, with one mole of an amine of the formula (Vc):

R¹ C-NH₂ (Vc) where R^1c is as defined above for formula (Ic). Within these sequences, the reactions between the amine intermediates and the corresponding isocyanates proceed readily at moderate temperatures e.g. from ambient to 100⁰C, particularly from 25 to 80⁰C, especially from 30 to 7O⁰C. We have not found it necessary to use a catalyst, but one could be included if desired. Generally this reaction will be carried out in solution or dispersion e.g. in a hydroxylic solvent such as mono-propylene glycol or glycerol, usually the same solvent as used in the previous step (see below).

The precursor amines, particularly of the formulae (Ua), (lib), and (lie), can be regarded as (or potentially as) Schiff bases or imines and the reaction making these materials is in principle reversible, particularly in the presence of excess water. Further, these amines can be regarded as an equilibrium mixture of an open chain imino and closed ring amine substituted structures. The formulae (Ha), (lib), and (lie) show the structure as the amine (closed ring) form as this is the form that reacts with the isocyanates and also appears to be the predominant form. This reaction to form the Schiff bases proceeds readily at moderate temperatures apparently to or close to completion without the need to remove the by-product water. However, addition of water, e.g. as in making an aqueous emulsion formulation, would be expected to reverse the reaction. The subsequent reaction with the isocyanate is effectively irreversible, thus "fixing" the structure of compounds of the formulae (I), (Ia), (Ib), and (Ic). The reaction between the reducing saccharide or oligosaccharide and amine generally proceeds readily at moderate temperatures e.g. from ambient to 100⁰C, particularly from 25 to 80⁰C, especially from 30 to 7O⁰C. We have not found it necessary to use a catalyst, but one could be included if desired. Generally this reaction will be carried out in solution or dispersion e.g. in a hydroxylic organic solvent such as mono-propylene glycol (MPG) or glycerol, and usually the same solvent will be used in the following step (see above). The reaction making the Schiff base releases water and is generally readily reversible, so including water in the reaction mixture unnecessarily is undesirable. We have found that using nominally dry or anhydrous starting materials, the reaction proceeds to substantial completion without the specific removal of the water formed in the reaction. However, care will normally be taken to avoid adding free water to the reaction mixture. This may be particularly relevant if glycerol is used as the reaction solvent/diluent because commercially available glycerol typically contains significant amounts of water e.g. up to ca 1%, commonly about 0.5% (ultrapure glycerol is available but expensive). For this reason MPG may be preferred as this is readily available in substantially anhydrous form. Saccharides, particularly reducing saccharides, are well known to react with amines in Maillard type reactions to produce coloured materials and this is generally undesirable. Accordingly, in making compounds of and used in this invention by the sequence outlined above, particularly in steps involving reaction of saccharides, including oligosaccharides, especially those including reducing saccharide residues, with amines, the reaction temperatures will be kept as low as conveniently possible to reduce the extent of such colour forming reactions. Similarly at elevated temperatures oxidation or pyrolysis reactions may give rise to coloured products (caramelisation) and the reactions may be carried out in an inert atmosphere to reduce this. We have found that the Maillard type reactions tend to take place more readily than caramelisation so using an inert atmosphere may not offer major benefit, provided the reaction temperatures is not allowed to rise substantially above about 80⁰C.

The molar proportions referred to above are those theoretically required for the desired reactions. It is generally desirable to use a slight to moderate excess of reducing saccharide or oligosaccharide over amine in making the intermediate Schiff bases to reduce the risk of leaving free amine in the final products (undesirable especially in personal care products). In the subsequent reaction with the isocyanate, a slight excess of isocyanate may be tolerated to ensure complete reaction of the Schiff base because there will be many other groups containing reactive hydrogen atoms, especially OH groups in the molecules and any such slight excess of isocyanate will readily react with these - forming pendent carbamate groups which may provide a modest further source of hydrophobic groups - thus removing the isocyanate from the reaction mix. The extent of any such surplus of isocyanate will be as small as reasonably possible as, by reaction with OH groups it will make the molecules more hydrophobic. The surfactant compounds of and used in this invention include oligosaccharide residues which will usually make them hydrophilic and typically water soluble or dispersible and thus can be used as surfactants in water based systems, particularly as oil in water emulsifiers. In particular, the compounds of and used in the invention generally have HLB values greater than 7 and typically in the range 10 to 20, more particularly 12 to 18 and especially 14 to 17.

A wide range of disperse phase oils can be used in the emulsions of the invention including mineral oils, alkoxylated, particularly propoxylated, fatty alcohols, ester oils including natural triglyceride oils, particularly vegetable oils, modified, particularly alkylated, vegetable oils, fatty acid esters and more complex esters such as triethylhexanoin, and silicone oils such as cyclomethicone oils. The proportion of the disperse oil phase may vary widely and the amount of oil is typically from 1 to 90%, usually 3 to 60%, more usually 5 to 40%, particularly 8 to 20%, and especially 10 to 15% by weight of the total emulsion.

Such emulsions can be used in personal care applications; in emulsion polymerisation; in crop protection formulations; and other applications. The electrolyte tolerance of the compounds of and used in the present invention, particularly of compounds of the formula (I), makes them useful in personal care applications where electrolyte tolerance is important e.g. in stick deodorant and anti- perspirant roll-on formulations, especially those based on aluminium salts, and in agrochemica! formulations especially combination formulations including both a pesticide or herbicide and a fertilizer. The properties of the surfactants of this invention make them particularly suitable as emulsifiers in oil in water personal care emulsions. Personal care emulsion products can take the form of creams and milks desirably and typically include emulsifier to aid formation and stability of the emulsion. Typically, personal care emulsion products use emulsifiers (including emulsion stabilisers) in amounts of about 3 to about 5% by weight of the emulsion. The oil phase of such emulsions are typically emollient oils of the type used in personal care or cosmetic products, which are oily materials which is liquid at ambient temperature or solid at ambient temperature, in bulk usually being a waxy solid, provided it is liquid at an elevated temperature, typically up to 100⁰C more usually about 8O⁰C, so such solid emollients desirably have melting temperatures less than 100⁰C₁ and usually less than 7O⁰C, at which it can be included in and emulsified in the composition.

The concentration of the oil phase may vary widely and the amount of oil is typically from 1 to 90%, usually 3 to 60%, more usually 5 to 40%, particularly 8 to 20%, and especially 10 to 15% by weight of the total emulsion. The amount of water (or polyol, e.g. glycerine) present in the emulsion is typically greater than 5%, usually from 30 to 90%, more usually 50 to 90%, particularly 70 to 85%, and especially 75 to 80% by weight of the total composition. The amount of surfactant used on such emulsions is typically from 0.1 to 10%, more usually 0.5 to 8%, more desirably 1 to 7%, particularly 1.5 to 6%, and especially 2 to 5.5%, by weight of the emulsion.

The end uses formulations of such emulsions include moisturizers, sunscreens, after sun products, body butters, gel creams, high perfume containing products, perfume creams, baby care products, hair conditioners, skin toning and skin whitening products, water-free products, anti-perspirant and deodorant products, tanning products, cleansers, 2-in-1 foaming emulsions, multiple emulsions, preservative free products, emulsifier free products, mild formulations, scrub formulations e.g. containing solid beads, silicone in water formulations, pigment containing products, sprayable emulsions, colour cosmetics, conditioners, shower products, foaming emulsions, make-up remover, eye make-up remover, and wipes. A preferred formulation type is a sunscreen containing one or more organic sunscreens and/or inorganic sunscreens such as metal oxides, but desirably includes at least one particulate titanium dioxide and/or zinc oxide. A further use that takes particular advantage of the electrolyte tolerance of the surfactants of and used in the invention is in making emulsion deodorants and anti-perspirant formulations, particularly stick deodorants and roll on anti- perspirants, because in such formulations the active materials typically include metal compounds or salts e.g. aluminium chlorohydrates, which contain or may hydrolyse to yield ionic species.

The surfactants of and used in the invention are also useful in emulsions including other components that can be difficult to formulate including skin moisturising additives such as urea, typically used for this purpose at up to 10% by weight, skin cooling additives such as ethanol, typically used for this purpose at up to 25% by weight and skin smoothing alpha-hydroxy acids such as glycolic and lactic acids and beta-hydroxy acids, such as salicylic acid, and their salts.

The compounds of and used in the invention can used as emulsifiers in agrochemical formulations, in particular for emulsion formulations incorporating herbicides and/or pesticides such as, fungicides, insecticides, acaricides and/or plant growth regulator formulations and/or fertiliser materials which may be water soluble electrolyte materials such as inorganic salts containing nitrogen, potassium and/or sulphur, and in particular for combination formulations including both a herbicide and/or pesticide and/or plant growth regulator and a fertiliser, particular a water soluble electrolyte containing fertiliser. The amount of surfactant used in such emulsions is typically from 1 to 30%, more usually from 2 to 10%, by weight based on the formulation. In such emulsion formulations, the disperse oil phase is commonly used as a solvent or carrier for the agrochemical active and oils commonly used for this include mineral oils, vegetable oils and alkylated vegetable oils. The formulations may further include solvents and/or diluents; and/or other surfactants which may be anionic surfactants, cationic surfactants or non-ionic surfactants. Such other components will, as with formulations using purely conventional surfactants, be used in amounts based on the desired effect. The following Examples illustrate the invention. All parts and percentages are by weight unless otherwise stated.

Materials

Dextrins DX1 19 DE maltodextrin ca DP 5.3, Glucidex 19 ex Roquette

DX2 12 DE maltodextrin ca DP 8.3, Glucidex 12 ex Roquette

DX3 14 DE maltodextrin ca DP 7.1 , CDry MD 01910 ex Cerestar

DX4 15 DE maltodextrin ca DP 6.7, Maldex 150 ex Amylum

Amines AM1 methylamine (33% w/w in ethanol) ex Aldrich

AM2 ethanolamine

AM3 octadecylamine, Rofamin STD ex EcogreenOleo

AM4 tallowamine, Armeen TD ex Akzo Nobel

AM5 n-hexadecylamine ex Aldrich AM6 oleylamine ex Aldrich

AM7 cocoamine, Rofamin KD ex EcogreenOleo

AM8 fatty amine derived from rape oil fatty acid, Rofamin RD ex EcogreenOleo lsocyanates

IC1 /7-octadecylisocyanate ex Bayer (now Lanxess) IC2 n-butylisocyanate ex Aldrich

IC3 1 ,6-hexyldiisocyanate ex Aldrich

IC4 isophoronediisocyanate ex Aldrich

IC5 4,4^Λ-methylenebis(phenylisocyanate) (MDI) ex Aldrich

Solvent SoM monopropyleneglycol (MPG)

Sol2 glycerol

Conventional Surfactants

Surf1 stearyl alcohol 20-ethoxylate, Brij 78 ex Uniqema

Surf2 stearyl alcohol 2-ethoxylate, Brij 72 ex Uniqema Surf3 stearyl alcohol 21-ethoxylate, Brij 721 ex Uniqema

Surf4 sorbitan monostearate Arlacel 60V ex Uniqema

Surf5 glycerol monostearate (43% monoester), Estol 1474 ex Uniqema

Surfδ sorbitol monostearate ex Uniqema

Surf7 glycerol monostearate 98% mono content, Armostat 1000P ex Akzo Nobel Surfδ stearyl alcohol ex Aldrich Oils

OiH /so-hexadecane, Arlamol HD ex Uniqema

0112 stearyl alcohol 15-propoxylate, Arlamol E ex Uniqema

0113 triethylhexanoin, Estol 3609 ex Uniqema Oil4 cyclomethicone, ex Dow Corning

Anti-Perspirant materials

AP1 aluminium chlorohydrate, Locron ex Clariant

Hydrophilic-Lipophilic balance (HLB)

We have found that HLB values for the compounds of and used in this invention can be calculated by considering a notional equivalent compound by substituting 7 EO residues for each saccharide residue (based on the average number in the molecule) and then calculating the HLB from the usual formula: HLB = (wt% EO in surfactant)/5. The resulting values provide a good match for the emulsification properties of the compounds especially as compared with alcohol ethoxylates having well established HLB values. Synthesis Examples

Example SE1 Λ/-maltodextrinyl-Λ/-(2-hydroxyethyl)-Λ/'-octadecyl urea

Dextrin DX1 (50 g; 56 mmol) was dissolved in solvent SoH (65.8 g) by warming at 100⁰C for 30 minutes; then the mixture was cooled to 5O⁰C, ethanolamine (2.56 g, 42 mmol) was added and the resulting mixture was stirred for 2h at 5O⁰C. (For some runs the reaction mixture stood at ambient temperature overnight at this stage.) The mixture was warmed to 60⁰C and isocyanate IC1 (13.24g, 45 mmol) was added and stirred for 4h (following the reaction using IR spectroscopy). The product was obtained as a white viscous sticky paste. The identity of the product was confirmed using MS (MALDI) and IR and NMR spectroscopy.

Various reaction runs were carried out altering the starting materials or their proportions, to obtain different products, solvent and amount of solvent, and reaction conditions, particularly temperature and time. Bis-urea compounds were made by a similar general reaction scheme, but substituting an equivalent proportion of a di-isocyanate for the isocyanate used in Example SE1.

The materials used and reaction conditions are summarised in Tables 1a and 1b below. Table 1a (Synthesis Examples - Materials)

(1 ) The amount of solvent is given as a proportion of the starting reaction mixture

(1) after the 1st stage, the reaction mixture stood overnight at ambient temperature

Application Examples

In the Application Examples, the amounts of emulsifier used are amounts of active emulsifier. In many cases the actual amount of material added will be larger because of the presence of solvent or diluent e.g. from the synthesis.

Application Test Methods

Emulsion stability - 50 ml samples were stored at ambient temperature (Amb) or at 5O⁰C and visually assessing stability after 1 day (1 d), 1 week (1 w) and 1 month (1m). The form of the emulsion (if not as smooth fluid) and the extent of any separation is abbreviated: Gr: grainy emulsion; NS: no separation; Tr: trace (of separation or coalescence); Sb: separation from the bottom (may include a % estimate); St: separation from the top (may include a % estimate); Co: coalescence; Cr: creaming; Br: emulsion broken.

Emulsion droplet size - was measured using a Coulter Multisizer Il - the number average droplet size is quoted in μm. Application Example AE1 - Preparation of oil in water emulsions

Oil in water emulsions were prepared using 1% surfactant (SE 4) as the solution obtained directly from the synthesis reaction (surfactant SE 4a run AE 1.1) or as solid precipitated from the synthetic reaction mix by adding acetone and then filtering and drying the product (surfactant SE 4b run AE 1.2), and 20% of OiH non-polar oil using compounds of the formula (I) and a conventional fatty alcohol ethoxylate (Surfi) for comparison.

Material Amount (% w/w)

Oil 1 20

Test Surfactant 1

Water 79

The aqueous phase was prepared by dissolving 2 g samples of surfactant in 158 g water with stirring. 40 g of the oil was then added slowly and the mixture was homogenised in an Ultra Turrax blender at 13500 rpm (225 Hz) for 2 min. The droplet size of each emulsion was measured and the emulsions assessed for storage stability; at ambient temperature and at 5O⁰C. The results are set out in Table AE1 below.

Table AE1

Application Example AE2

Roll-on anti-perspirant emulsion formulations were prepared based on a reference formulation using 1.5% by weight of non-ionic fatty alcohol ethoxylate water soluble surfactant (Surf3). Experimental formulations were made up using the following proportions:

Material Amount (%w/w)

Water phase Test Surfactant (see Table AE2)

Water to 100

Oil Phase Surf2 3.5

Oil2 4

Oil3 1

Oil4 3

Anti-oersDirant AP1 20

Method

The water phase was made up by dissolving the test surfactant (usually dissolved in the solvent used in its synthesis) in the water in a beaker at ambient temperature under stirring to give a dear solution. The oil phase was made up in a separate beaker by mixing the oil phase surfactant, Surf2, and the oils (Oil2, Oil3 and Oil4). The two mixtures were heated separately on a water bath at 8O⁰C until the oil phase was a clear solution, removed from the water bath and the water phase slowly added to the stirred oil phase and stirring continued until the temperature reached 5O⁰C. The emulsion was then homogenised in an Ultra Turrax blender at 13500 rpm (225 Hz) for 2 min. The anti-perspirant component AP1 was then added slowly to the stirred emulsion and the mixture allowed to cool to ambient temperature. The emulsions were assessed for storage stability; at room temperature and at 5O⁰C. The results, using a range of quantity of test surfactant, are set out in Table AE2 below. Generally, the surfactants of and used in the invention were used as the direct products of the synthesis examples i.e. as a solution in the solvent used in the synthesis. The proportions of this product used were calculated based on the known amount of solvent used in the synthesis to give the desired proportion of the (unpurified) "active" surfactant for the test run. Where present, the solvent is not specifically mentioned in the composition noted above. In Application Example AE2.1, the surfactant used was a solid powder obtained by precipitation from the reaction mixture by adding acetone and then filtering and drying the product.

Table AE2 (Roll on anti-perspirant formulations)

(1 ) Surfactant added to oil phase during formulation

(2) Surfactant used as solid by acetone precipitation Application Example AE3

Roll-on anti-perspirants emulsion formulations including various cosurfactants were made as generally described in Example AE2 using various emulsifiers and substituting other coemulsifiers for the fatty alcohol ethoxylate, Surf2, used in AE2. The formulations and test results are set out in Table AE3 below.

General formulation:

Material Amount (%w/w)

Water phase Test Surfactant (see Table AE3)

Water to 100

Oil Phase Various (see table AE3) 3.5

Oil2 4

Oil3 1

Oil4 3

Anti-perspirant AP1 20

Table AE3 (Roll on anti-pi srspirant formulati

(1 ) Surfactant added to oil phase during formulation

Claims

Claims 1 An oil in water emulsion which include as an emulsifier at least one surfactant compound which is a long chain fatty mono-or di-urea including at least one oligosaccharide residue substituted on a urea nitrogen atom. 2 An emulsion as claimed in claim 1 wherein the surfactant compound is of the formula (I): H-[S]n-Sj-N(R1 )-C(O)-NHR2 (I) where each S is the residue of monosaccharide; n is an average value of from 0 to 50, particularly 2 to 20; Sj is a deoxy residue of a reducing monosaccharide residue; and R1 is a C-] to C22 hydrocarbyl or hydroxyhydrocarbyl group; or R1 is a group of the formula: -R1 b-NH (O)C-N(R2b)-Sj-[S]n-H; where each S, n, and Sj is independently as defined above and where R""3 is a C2 to C22 hydrocarbylene group; and R2b is C^ to C22 hydrocarbyl group; or R2 is a C-j to C22 hydrocarbyl group; or R2 is a group of the formula: -R2c-NH-(O)C-N(R1 c)-Sj-[S]n-H; where each S, n, and Sj is independently as defined above and R1 c is C-j to C22 hydrocarbyl or hydroxyhydrocarbyl group; and R2c is a C2 to C22 hydrocarbylene group, and wherein at least one of R1 (when it is a hydrocarbyl group), R1 b and R1c (when present), R2 (when it is a hydrocarbyl group) and R2b and R2c (when present) is a CQ to C229rouP- 3 An emulsion as claimed in claim 2 wherein the surfactant compound is of the formula (Ia): H-[S]n-Sj-N(R1 a)-C(O)-NHR2a (Ia) where each S, n and Sj is independently as defined for formula (I); R1a is a Ci to C22 hydrocarbyl or hydroxyhydrocarbyl group; and R2a is a C-| to C22 hydrocarbyl group; and wherein at least one of the groups R^ a and R2a is a Cg to C22 group. 4 An emulsion as claimed in claim 2 wherein the surfactant compound is of the formula (Ib): R2bHN(O)C C(O)-NH-R2b H-[S]n-Sj-N-R1 b-N-Sj-[S]n-H (Ib) where each S1 n, Sj, R1^ and R2b is independently as defined for formula (I); and wherein at least one of groups R1 b and R2b is a Cs to C22 group. 5 An emulsion compound as claimed in claim 2 wherein the surfactant compound is of the formula (Ic): H-[S]n-Sj-N(R1 c)-C(O)-NH-R2c-NH-C(O)-N(R1 c)Sj-[S]n-H (Ic) where each S, n, Sj, R1c and R2c is independently as defined for formula (I); and wherein at least one of the groups R1 c and R2c is a C% to C22 group. 6 An emulsion compound as claimed in any one of claims 2 to 5 in which at least one of the following conditions is met:

(1 ) n is at least .2, particularly 3 to 20, especially 5 to 20;

(2) at least one of R¹, R^{1 a}, R^{1 c}, R², R^2a and R^2b is C₁₀ to C₂2. particularly a C₁₄ to C20. and especially a C₁ ρ to C20. hydrocarbyl and/or at least one of R^""⁵ and R^2c is C₁Q to C22₁ particularly a C₁₄ to C20. and especially a C₁ g to C20. hydrocarbylene; and

(3) one or more of the groups R¹ , R^{1 a} and R^{1 c} is a C2 to CQ, particularly C2 to C₄, a hydroxyhydrocarbyl group especially a 2-hydroxyethyl or 2- or 3-hydroxypropyl group.

7 An emulsion as claimed in any one of claims 1 to 6 in the form of a personal care emulsion in which the disperse oil phase is an emollient oil or wax.

8 An emulsion as claimed in claim 11 in the form of a cream or a milk and including from 3 to 5% by weight of the emulsion of emulsifier and/or emulsion stabiliser.

9 An emulsion as claimed in any one of claims 1 to 6 in the form of an agrochemical emulsion including at least one pesticide or herbicide. 10 An emulsion as claimed in claim 9 which additionally includes at least one fertilizer.

11 A surfactant compound of the formula (Ib):

R^2bHN(O)C C(O)-NH-R^2b

I -u I

H-[S]_n-Sj-N-R^{1 b}-N-Sj-[S]_n-H (Ib) where each S, n, Sj, R^{1 b} and R^2b is independently as defined for formula (I) in claim 1; and wherein at least one of groups R^{1 b} and R^2b is a CQ to C22 group.

12 A surfactant compound of the formula (Ic):

H-[S]_n-Sj-N(R^{1 c})-C(O)-NH-R^2c-NH-C(O)-N(R^{1 c})Sj-[S]_n-H (Ic) where each S, n, Sj, R^{1 c} and R^2c is independently as defined for formula (I) in claim 1 ; and wherein at least one of the groups R^{1 c} and R^2c is a Cs to C22 group.