WO2001038398A1

WO2001038398A1 - Hydrophobically modified polyols

Info

Publication number: WO2001038398A1
Application number: PCT/EP2000/011782
Authority: WO
Inventors: Jan Gerardus Batelaan
Original assignee: Akzo Nobel N.V.
Priority date: 1999-11-24
Filing date: 2000-11-20
Publication date: 2001-05-31
Also published as: NL1013658C2; AU2162801A

Abstract

Hydrophobically modified polyols, preferably obtainable by reacting at least a portion of the phosphate groups of polyol phosphates having a weight average molecular weight of at least 1,000 with a non-ionic mono-epoxide. The polyol phosphates preferably are compounds selected from the group of (a) phosphorylated polysaccharides, (b) wholly or partially saponified polyvinyl acetate, and (c) homo- or copolymers of polyhydroxyethyl(meth)acrylate. The non-ionic mono-epoxide advantageously comprises a compound of the formula: R1-(OCH2CH(R2))n-Q, wherein R1 has the meaning of a C1-C30 group, R2 is hydrogen or methyl, n is 0-10, and Q stands for a 1,2-epoxy group or a glycidyl ether group.

Description

HYDROPHOBICALLY MODIFIED POLYOLS

The invention pertains to hydrophobically modified polyols, and to inulin phosphate.

The literature discloses many processes for the preparation of hydrophobically modified polyols. For example, EP-A-0 384 167 discloses a process in which use is made of a polysaccharide with ether substitution which is then converted with a hydrophobic alkylaryl compound. Using a polysaccharide with ether substitution instead of an unsubstituted polysaccharide results in more of the hydrophobic alkylaryl compound being built in. While this makes for a more efficient hydrophobizing reaction, there is great need for yet further enhancement thereof.

EP-A-0 566 911 discloses a process in which a polysaccharide is reacted with an alkyl halide, an alkylene oxide or chloroacetic acid in the presence of alkali and then reacted with a compound containing a hydrophobic alkyl group or alkylaryl group having 8 to 24 carbon atoms and a reactive group such as a glycidyl ether, epoxide or isocyanate. As in the case of the first patent publication mentioned, there is the drawback here of low efficiency of the compounds' substitution with hydrophobic groups.

Finally, EP-A-0 189 935 discloses a process for the preparation of water- soluble, hydrophobe-derivatized polysaccharides, more particularly hydroxy- ethyl cellulose (HEC). In this process HEC is alkylated with a quaternary nitrogen-containing compound such as 3-chloro-2-hydroxypropyl trimethyl- ammonium chloride and a hydrophobic alkyl halide such as dodecyl bromide. In one example (run no. 35) a Degree of Molar Substitution (= MS or the average number of moles of a particular reaction component bound per anhydroglucose unit) of 0.016 was obtained. From this a hydrophobe substitution efficiency of 13% can be calculated. A drawback to the process disclosed in this publication is that the thus obtained hydrophobically modified polysaccharide will always contain a quaternary ammonium group. Because of their high aquatoxicity and their tendency to adsorb on all surfaces, cationic polymers are less desirable particularly for environmental reasons.

The invention now provides hydrophobically modified polyols which are free of quaternary ammonium groups and which can be prepared comparatively quickly and without any problems.

The invention consists in that the hydrophobically modified polyols are obtainable by reacting at least a portion of the phosphate groups of a polyol phosphate having a molecular weight of at least 1 ,000 with a non-ionic mono- epoxide.

It should be noted that the reaction of a polyol phosphate such as polysaccharide phosphate with an epoxy compound is known as such from US- A-5,409,705. The epoxy compound employed in that document is an ionic mono-epoxide, viz. an epoxidized quaternary ammonium compound. Per phosphate group not more than one epoxy compound is added. Thus the invention also pertains to a hydrophobically modified phosphorylated polyol having a molecular weight of at least 1 ,000, characterized in that at least a portion of the phosphate groups of the polyol contains a non-ionic hydroxy group-containing moiety, the hydroxy group being in the β position of the moiety with regard to the phosphate group.

Also in WO 97/30090 there is question of polysaccharide phosphate, more particularly cellulose phosphate, being reacted with an epoxy compound, albeit that in this document there is question only of using a difunctional epoxide as a cross-linking agent to reduce the solubility. Surprisingly, it has been found that when use is made of a non-ionic mono- epoxy compound, the reaction with polyol phosphates such as cellulose phosphate leads to a much higher substitution efficiency than when use is made of an epoxide incorporating a quaternary ammonium group. Very likely this has to be attributed to the fact that as soon as one of the two acid groups present in a polyol phosphate ester group has reacted with the epoxy group of an non- ionic mono-epoxide, the remaining acid group's reactivity towards an epoxy group is much higher than that of the two acid groups originally present. One of the consequences of this phenomenon is that it is possible to prepare polyols in which the phosphate groups in the hydrophobically modified polyol consist practically entirely of monoester phosphate groups not yet reacted with epoxy groups on the one hand and triester phosphate groups fully reacted with epoxy groups on the other. A significant advantage of this is that usually two hydrophobic groups are present per hydrophobically modified phosphate group. Because of this, the same effect can be achieved using hydrophobic groups of far lower molecular weight than when only one hydrophobic group is present per phosphate group, as is the case with the well-known polysaccharide derivatives discussed above. Thus it is also an object of the invention to provide a hydrophobically modified phosphorylated polyol having a weight average molecular weight of at least 1 ,000 comprising monoester phosphate groups and hydrophobically modified triester phosphate groups. Preferably, the ratio of monoester phosphate groups and hydrophobically modified triester phosphate groups is 1000:1 to 1 :10, more preferably 100:1 to 1 :1. A further advantage consists in that the hydrophobically modified phosphate esters are easy to hydrolyze by the biological route, which as a rule produces products harmless to nature. This holds particularly in the case of polysaccharide-based polyol phosphate esters, the decomposition products of which are non-toxic to fish, crustaceans or algae. What is especially remarkable about these phosphate esters is that they have properties which closely match those of existing commercial products made of non-recyclable raw materials. The term "hydrophobic group" as used in this invention, means a group that is bonded to a phosphate group and that increases the hydrophobicity of the polyol. Thus the hydrophobic modified polyols are more hydrophobic than the unmodified polyols. Preferably, the hydrophobic groups contains 1-30 C atoms, more preferably 4 to 22 C atoms.

The polyols which, according to the invention, after reaction with phosphoric acid are eligible for reaction with a non-ionic mono-epoxide to form polyol- phosphates are preferably selected from the group of polysaccharides, wholly or partially saponified polyvinyl acetate, and homo- or copolymers of polyhydroxyalkyl(meth)acrylate, more in particular polyhydroxyethyl(meth)acrylate.

The polysaccharides preferably comprise compounds having at least 10 monosaccharide units and belong to the group of starch, amylose, amylopectine, maltose, cellulose, dextran, and inulin.

Polyolphosphates can be obtained with the aid of many processes known from the state of the art. In one preferred embodiment, the procedure usually is as follows. First, a polyol is reacted with a polyphosphoric acid having a P₂O₅ content of greater than 72% (preferably from 82 to 84%). When the P₂O₅ content exceeds about 85%, the number of diester phosphate groups, and thus the degree of cross-linking, will increase substantially. Preferably, use is made of amounts of polyphosphoric acid which correspond to 0.5 to about 1.0 mole equivalent P₂Os for every polyol equivalent. By "polyol equivalent" is meant the equivalent number of hydroxyl groups present in the polyol. If so desired, an excess of P₂O₅ may be employed in the reaction.

An alternative method consists in that instead of P₂O5, urea phosphate, i.e. urea mixed with orthophosphoric acid is employed as phosphatizing agent. When preparing urea phosphate preferably use is made of a molar ratio of urea to orthophosphoric acid in the range of 1.0 to 2.0. More particularly, when phosphorylating low-molecular weight polyvinyl alcohol advantageous use is made of urea phosphate.

Phosphorylated starch is supplied by AVEBA under the trade designation "Nylgum™".

When the polysaccharide used is cellulose, preference is given to a process in which cellulose is added to a polyphosphoric acid having a P₂Os content of 72- 85 wt.% in an appropriate kneader and/or mixer to give a solution 94-100 wt.% of which is composed of the constituents cellulose, phosphoric acid and/or its anhydrides, and water. Examples of suitable cellulose phosphate compositions are listed in WO 96/06208 and WO 97/28298.

Inulin phosphates having a molecular weight of at least 1000 that are suitable for making the hydrophobically modified polyols of the invention are not known as such. They can be made in a manner analogously to that of the synthesis of other phosphorylated polysaccharides, such as the phosphorylation of cellulose, starch, dextran, and the like.

According to the invention, the term "phosphoπc acid" means all inorganic acids of phosphorus and/or their mixtures. Orthophosphoric acid (H₃PO ) is the acid of pentavalent phosphorus. Its anhydrous equivalent, i.e. the anhydride, is phosphorus pentoxide (P₂O₅). In addition to orthophosphoric acid and phosphorus pentoxide there is, depending on the amount of water in the system, a series of acids of pentavalent phosphorus with a water-binding capacity in between those of phosphorus pentoxide and orthophosphoric acid, e.g. (H₆P₄O₁₃, PPA).

In addition to water, phosphoric acid and its anhydrides, and polyols and/or reaction products of phosphoric acid and polyols, other substances may be present in the solution when preparing phosphorylated polyols. The solution can be obtained by mixing constituents classifiable into four groups: polyols, more particularly polysaccharides such as cellulose, water, inorganic acids of phosphorus including their anhydrides, and other constituents. These "other constituents" may be substances which benefit the processability of the polyol solution, solvents other than phosphoric acid, moisturizing additives or adjuvants (additives), e.g., to counter polyol degradation as fully as possible, or dyes and the like.

Where there is question within the framework of this description of weight percentages of dissolved polyols, more particularly dissolved polysaccharides, in the case of the polysaccharides with phosphorus bound thereto, these weight percentages relate to quantities calculated back on the phosphorus-free polyols. The same holds, mutatis mutandis, for the weight percentages of dissolved phosphorus listed in the description. It was found that, in general, very favorable results are achieved when the hydrophobically modified polyols are obtained from phosphorylated polysaccharides or a polysaccharide phosphate having a degree of substitution DSp in the range of 0.001 to 3, preference being given to a degree of substitution of 0.05 to 1.5. In the case of cellulose phosphate, optimum results are obtained with a molecular weight <250,000 and a degree of substitution of 0.1 to 1.0.

Hydrophobically modified polyols with favorable properties are compounds obtained by reacting polyol phosphates with a non-ionic mono-epoxide of the formula: R₁-(OCH₂CH(R₂))_n-Q, wherein Ri has the meaning of a C C3o group, R₂ is hydrogen or methyl, n is 0-10, and Q stands for a 1 ,2-epoxy group or a glycidyl ether group. Products having very favorable properties are obtained by reaction with an epoxide of the aforementioned formula wherein Ri has the meaning of a linear or branched butyl such as n-butyl, isobutyl, tert-butyl or sec-butyl, and n=0. Preferred are products which are obtained by reaction with compounds of the aforementioned formula wherein Ri has the meaning of a C -C₂₂ group, more particularly a C₈-C₂₂ group.

Suitable epoxides also comprise compounds of the aforementioned formula wherein Ri has the meaning of a nonylphenyl, 2-ethylhexyl, dodecyl, tetradecyl, hexadecyl, octadecyl or hexacosyl group. Ri usually is derived from fatty acids such as are found in nature, originating from coconut oil, palm oil, talc, and hydrogenated talc. If so desired, one or more alkylene oxide groups may be incorporated into the epoxides, e.g., ethylene oxide and propylene oxide. Representative examples of suitable epoxy compounds, which after reaction with the phosphate are transferred to hydrophobic groups attached to said phosphate, are: ethyl glycidyl ether, butyl glycidyl ether, butoxyethyl glycidyl ether, tert-butyl glycidyl ether, isobutyl glycidyl ether, propyl glycidyl ether, benzyl glycidyl ether. Preferred in this case are the dodecyl glycidyl ether, tetradecyl glycidyl ether, hexadecyl glycidyl ether, octadecyl glycidyl ether, dodecyl bis-(oxyethyl)-glycidyl ether, tetradecyl bis-(oxyethyl)-glycidyl ether, hexadecyl bis-(oxyethyl)-glycidyl ether, octadecyl-bis-(oxyethyl)-glycidyl ether, tetradecyl-penta(oxyethyl)-glycidyl ether, (2,3-epoxypropyl)benzene, styrene oxide, 1 ,2-epoxy-3-phenoxypropane, 2-methylphenyl glycidyl ether, 3-(pentadecadienyl)phenylglycidyl ether, 4-tert- butylphenyl-glycidyl ether, 4-chlorophenyl glycidyl ether, 4-methoxyphenyl glycidyl ether, or a mixture of these.

In general, preference is given to compounds where in the aforementioned formula R₂ represents hydrogen.

In addition, the aforementioned non-ionic mono-epoxides may carry substituents such as halogen or a blocked or unblocked reactive group, for instance a blocked isocyanate group. Particularly important are epoxides with an ethylenically unsaturated group such as are present in unsaturated fatty acids like oleic acid or linoleic acid. In this case both long-chain fatty acids and short-chain compounds such as are present in allyl glycidol are employed. The hydrophobically modified polyol can be put to advantageous use as a cross- linking agent in particular when said last compound is present. Of course, in addition other epoxides which may be unsaturated or not or aromatic or not may be present.

Under certain conditions the use of allyl glycidol may give rise to premature cross-linking.

It was found that there will be far fewer problems in this respect when the

(meth)acrylate ester of glycidol is used as the ethylenically unsaturated epoxide.

The reaction of polyol phosphate with a non-ionic mono-epoxide generally proceeds as follows. First, a suspension is made of the polyol phosphate to be derivatized in an alcohol (ethanol, or preferably 2-propanol), the addition of water, when 2-propanol is the reaction medium, having a favorable effect on the derivatization result. Some derivatizations can also be carried out in water.

Next, with proper stirring, the epoxide is added, either as such or as a solution in ethanol or an ethanol/water mixture. On conclusion of the exothermal reaction the mixture is stirred for a further 1/2 to 3 hours at a temperature in the range of 20 to 65°C. After cooling the reaction mixture if necessary is precipitated in a non-solvent such as acetone and then filtered and dried in vacuo at a temperature in the range of 65 to 75°C.

Depending on the nature of the starting polyol (polysaccharide, cellulose, polyvinyl alcohol or a copolymer of polyhydroxyethyl(meth)acrylate, the molecular weight, the weight percentage of phosphorus, and the nature of the hydrophobic substituents provided, the hydrophobically modified polyol derivatives according to the invention can be put to the widest possible range of uses. These include for example: propylene oxide-modified cellulose phosphate for the manufacture of films, the preparation of ink and paper, in paste for printing textiles, and as surface active agent in emulsion polymerization, glycidol-modified cellulose phosphate for the preparation of reversible gels to enhance oil drill holes porosity (fracturing), butyl glycidol-modified cellulose phosphate having a high degree of substitution: for use in coatings and ink, having a average degree of substitution: for use in coatings and ink and for coating tablets, having a low degree of substitution: for use as a surface active compound in detergents and cosmetics, fatty alkyl glycidol-modified cellulose phosphate or starch phosphate having a low degree of substitution: for use in detergents and cosmetics, glycidol methacrylate-modified cellulose phosphate having a low degree of substitution as polyacrylates cross-linking agent, allyl glycidol- or 1 ,2-epoxy-but-3-ene-modified cellulose phosphate having a low degree of substitution as polyacrylates cross-linking agent for superabsorbents, cellulose phosphate modified with aryl groups-containing epoxide as lubricant, butyl glycidol- and/or 2-ethylhexyl glycidol-modified starch phosphate or inulin phosphate for use as an emulsifier, allyl glycidol- or 1 ,2-epoxy-butene-modified (co)polymers of hydroxy- ethyl(meth)acrylate phosphate having a low degree of substitution as polyacrylates cross-linking agent for superabsorbents, branched alkyl glycidyl ether-modified starch phosphate, cellulose phosphate or inulin phosphate as low- or non-foaming emulsifier or dispersant, polyol phosphate modified with aryl groups-containing epoxide as flocculant, cellulose phosphate or starch phosphate substituted with C₄-C₁₄ epoxide as anti-redeposition agent or soil release agent in detergents, butyl glycidyl-modified cellulose phosphate or starch phosphate in the form of a film as packaging foil, cellulose phosphate or starch phosphate of high molecular weight and low degree of substitution substituted with C₁₀-C₂₂ epoxide as associative thickener, cellulose phosphate or starch phosphate of low molecular weight and low degree of substitution substituted with Cι₀-C₂₂ epoxide as cleaning surfactant in cleansing agents, and butyl glycidyl ether- and/or 2-ethylhexyl glycidyl ether-modified starch phosphate or inulin phosphate for use as co-surfactant.

The invention will be illustrated with reference to the following examples. Of course these examples are submitted for a better understanding of the invention only; they are not to be construed as limiting in any manner the scope thereof. For the preparation of polysaccharide derivatives three hydroxy groups are available per anhydroglucose unit. The examples employ the common terminology of this field of the art, wherein DS stands for "Degree of Substitution" and MS stands for "Degree of Molar Substitution," with DS representing the average number of substituted hydroxy groups per anhydroglucose unit and

MS representing the average number of moles of a particular reaction component bound per anhydroglucose unit.

Example I Preparation of reaction product of cellulose phosphate and propylene oxide

Into a 250 ml 3-neck flask equipped with a mechanical stirrer, a nitrogen inlet, and a reflux condenser were charged 4.6 g of cellulose phosphate (DSp = 0.42, corresponding to 20 meq acid) in 23 g of water. To this whole 30 ml (425 mmoles) of propylene oxide were in one go added at room temperature. The reaction proceeded highly exothermally, after which the flask was placed in an ice bath. On conclusion there was further stirring for 45 minutes at 40°C on a water bath. Titration with 0.08N NaOH of the dried product made it possible to ascertain that about 95% of the acid had been converted.

Example II

Esterification of cellulose phosphate with n-butyl glycidyl ether (BGE) 1 g of a cellulose phosphate having a degree of substitution DSp = 0.39 was suspended in a mixture of 1.56 g (11.98 mmoles) n-butyl glycidyl ether and 10 ml of ethanol, followed by 2 hours of stirring at 60°C. After cooling to room temperature 50 ml of ethanol were added and stirred. The precipitate formed was filtered off and then purified by washing with acetone, followed by filtration and drying in vacua at 40°C.

Obtained was 0.91 g of product, which corresponds to 60% of theory. Titration with 0.1 N NaOH made it possible to ascertain that 95% of the acid had been converted. The product had moderate foam stabilizing properties in aqueous systems.

Example III

Esterification of cellulose phosphate with n-butyl glycidyl ether (BGE)

Use was made of a cellulose phosphate having a degree of substitution DSp = 0.42. 45 g of this material were suspended for 10 minutes in 600 ml of a mixture of 94 parts by volume of 2-propanol and 6 parts by volume of water at about 65°C, after which 33 ml of n-butyl glycidyl ether of 95% purity (corresponding to about 219 mmoles, vs. 192 meq acid from the cellulose phosphate) were added in one go to the suspension at hand, and the whole was stirred for a further 4 hours at about 65°C.

After cooling the suspension was poured, with stirring, into 1.5 I of cold acetone and the whole was left to stand overnight at 2°C, followed by decanting of the supernatant, renewed stirring with 500 ml of fresh acetone, and finally separating the product from the reaction medium by means of filtration. After drying in vacuo for 16 hours at 60°C 49 g of end product were obtained, which corresponds to 70% of the theoretical amount.

Titration of a sample of dried material with 0.05 N NaOH made it possible to ascertain that the degree of substitution of the available acid with n-butyl glycidyl ether was about 0.26, which corresponds to a degree of derivatization of (0.26 / 0.84) x 100% = 31 %. The material obtained was water-soluble and showed excellent foam stabilizing properties.

Also, the material proved capable of reducing the surface tension of water to about 34 mN/m, as was determined on a solution containing 1.8 wt.% of the product. The surface tension of water used without addition of the product was 70.5 mN/m.

Example IV

Preparation of the diglycidol diester of cellulose phosphate Glycidol was prepared in situ by reacting 3-chloro-1 ,2-propanediol with NaOH.

To this reaction mixture was added cellulose phosphate with a degree of substitution DSp = 0.15.

On conclusion of the reaction titration showed that 79% of the available acid had been converted.

Example V

Esterification of cellulose phosphate with n-butyl glycidyl ether (BGE) and dodecyl glycidyl ether(DGE)

In a manner analogous to that described in Example II, 1 g of cellulose phosphate having a degree of substitution DS_P = 1 was suspended in a mixture of 3.41 g of n-butyl glycidyl ether and 5 ml of ethanol (the reaction mixture will then hold 8.3 meq acid protons vs. 24.9 mmoles of glycidyl ether), followed by stirring for 2 hours at 65°C. After cooling to room temperature 20 ml of ethanol were added and stirred. The precipitate formed was filtered and then purified by washing with acetone, after which it was filtered again, followed by drying in vacuo at 50°C.

The resulting products had the following properties: after reaction with n-butyl glycidyl ether only: MS_BGE=2.1. after reaction with a mixture of C /Cι₂-glycidyl ethers: MS_BGE=1.32 and MS_DGE=0.87. after reaction with C₁₂-glycidyl ether only: MS_DGE=0.13. Example VI

Preparation of the diallyl glycidyl diester of cellulose phosphate Into a 250 ml 3-neck flask equipped with a mechanical stirrer, a nitrogen inlet, and a reflux condenser were charged 5 g of cellulose phosphate (DS_P = 0.42, which corresponds to 21.3 meq acid) in 160 ml of ethanol/water 75/25 v/v mixture, after which the whole was heated to 65°C. Next, 5.62 g of allyl glycidyl ether (AGE), corresponding to 49.2 meq of epoxide, dissolved in 10 ml of ethanol were added, and the mixture was stirred for 3 hours at 65°C. After cooling in an ice bath the reaction mixture was poured, with stirring, into 1200 ml of acetone, followed by filtering of the suspension. The insoluble fraction was washed with fresh acetone. The gel fraction was isolated and the precipitate was purified by filtration and dried in vacuo. The yield of envisaged product was 2.9 g (which corresponds to about 39% of theory). Titration with 0.08N NaOH showed that about 21 % of the available protons had been converted, which corresponds to DSAGE = 0.18 and a degree of derivatization of (0.18/0.84) x 100% = about 21.4%.

Despite the relatively small number of derivatized groups the product proved to be very reactive and also to gel easily after the addition of an ammonium persulfate-containing radical initiator and heating.

Example VII

Preparation of the diglycidyl methacrylate diester of cellulose phosphate

Into a 2 I rotary evaporator were charged 40 g of cellulose phosphate (DS_P =

7.1 , which corresponds to 183 meq acid) in 800 ml of ethanol and 50 ml of water, whereupon the whole was heated for 1 hour at 65°C to give the fibers the opportunity to swell.

Next, 52 g of glycidyl methacrylate (corresponding to 366 meq epoxide) dissolved in 50 ml of ethanol were added, and the reaction mixture was stirred for a further 1.5 hours. After cooling on an ice bath and the addition of 500 ml of acetone the reaction mixture was stored in a refrigerator for 48 hours. After decanting of the supernatant and the addition of about 2 I of fresh acetone a product which was easy to filter was obtained. After being washed twice more with acetone the filtered product was dried in vacuo at 40°C, with 36 g of the envisaged product being obtained (55% of theory). The product was readily soluble in water and gelled on being heated in the presence of ammonium persulfate.

Example VIII

Preparation of inulin phosphate.

A 65 wt.% suspension of NaH₂PO in water was made, and 90 g of inulin (Frutafit type EXL™, ex. Sensus) was slurried into 250 ml of this suspension. The slurry was heated to 65°C, whereupon the NaH₂PO₄ was dissolved completely. The system was kept at that temperature for 30 minutes, after which the solids were separated by filtration under vacuum. The cake was spread into a thin layer and dried overnight under a nitrogen vent at reduced pressure, in a stove at 90°C. Phosphate salt impregnated inulin powder was obtained having a weight of 167 g.

Phosphatation of the inulin was performed by submersing a round-bottomed flask in silicon oil and heating it to a set temperature of 190°C, after which the phosphate salt impregnated inulin powder was added under stirring and applying a vacuum atmosphere. After 10 minutes of residence time the phosphatation reaction was completed. The roasted product was dissolved in water, to obtain a 40 wt.% solution and the non-reacted phosphates were removed by dialysis.

Claims

1. A hydrophobically modified phosphorylated polyol having a weight average molecular weight of at least 1 ,000, characterized in that at least a portion of the phosphate groups of the polyol contains a non-ionic hydroxy group- containing moiety, the hydroxy group being in the β position of the moiety with regard to the phosphate group.

2. A hydrophobically modified polyol obtainable by reacting at least a portion of the phosphate groups of a polyol phosphates having a weight average molecular weight of at least 1 ,000 with a non-ionic mono-epoxide.

3. A hydrophobically modified phosphorylated polyol having a weight average molecular weight of at least 1 ,000 comprising monoester phosphate groups and hydrophobically modified triester phosphate groups.

4. The hydrophobically modified polyol of any one of claims 1 to 3, characterized in that the polyol phosphate is selected from the group of phosphorylated (a) polysaccharide,

(b) wholly or partially saponified polyvinyl acetate, and

(c) homo- or copolymers of polyhydroxyethyl(meth)acrylate.

5. The hydrophobically modified polyol of claim 4 wherein the polyol phosphate polyol is a polysaccharide phosphate having at least 10 monosaccharide units which belongs to the group of amylose, amylopectine, maltose, dextran, and inulin, and preferably, starch and cellulose.

6. The hydrophobically modified polyol of any one of claims 1 to 5 wherein the degree of substitution DSp of the polysaccharide phosphate is in the range of 0.001 to 3, preferably in the range 0.05 to 1.5.

7. The hydrophobically modified polyol of claim 2 wherein the non-ionic mono- epoxide comprises a compound of the formula: R₁-(OCH₂CH(R₂))_n-Q, wherein

Ri has the meaning of a C₁-C₃₀ group, R₂ is hydrogen or methyl, n is 0-10, and Q stands for a 1 ,2-epoxy group or a glycidyl ether group.

8. The hydrophobically modified polyol of claim 7 wherein Ri has the meaning of a linear or branched butyl group and n = 0.

9. The hydrophobically modified polyol of claim 7 wherein that Ri has the meaning of a C₈-C₂₂ group.

10. The hydrophobically modified polyol of claim 7 wherein the non-ionic mono- epoxide is selected from allyl glycidyl ether, ethyl glycidyl ether, butyl glycidyl ether, butoxyethyl glycidyl ether, tert-butyl glycidyl ether, iso-butyl glycidyl ether, propyl glycidyl ether, benzyl glycidyl ether, dodecyl glycidyl ether, tetradecyl glycidyl ether, hexadecyl glycidyl ether, octadecyl glycidyl ether, dodecyl bis-(oxyethyl)-glycidyl ether, tetradecyl bis-(oxyethyl)-glycidyl ether, hexadecyl bis-(oxyethyl)-glycidyl ether, octadecyl bis-(oxyethyl)-glycidyl ether, tetradecyl penta-(oxyethyl)-glycidyi ether, (2,3-epoxy-propyl)benzene, styrene oxide, 1 ,2-epoxy-3-phenoxy propane, 2-methylphenyl glycidyl ether, 3-(pentadecadienyl)phenyl glycidyl ether, the (meth)acrylate ester of glycidol, and mixtures thereof.

11. The hydrophobically modified polyol of claim 7 wherein the non-ionic mono- epoxide is allyl glycidyl ether or the (meth)acrylate ester of glycidol.

12. An inulin phosphate having weight average weight of at least 1 ,000 suitable for making the hydrophobically modified polyol of any one of claims 1-11.