EP0781292A1

EP0781292A1 - Mixture of alkylation products of acetalized monosaccharides and epoxides

Info

Publication number: EP0781292A1
Application number: EP95932657A
Authority: EP
Inventors: Alfred Oftring; Martin Aus Dem Kahmen; Günter OETTER; Richard Baur; Richard Schmidt; Hendrik Wulff
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 1994-09-14
Filing date: 1995-09-02
Publication date: 1997-07-02
Also published as: WO1996008501A1; DE4432689A1; JPH10505129A

Abstract

The invention concerns a mixture comprising alkylation products of monosaccharides, of the following formula (I): (CnH2n-1On)-R1, which are acetalized in position 1 by the radical R1, in which formula n stands for the number 5 or 6 and R1 designates a C¿1? to C4 alkyl group, a C1 to C3 mono or dihydroxyalkyl group or a C1 to C3 methoxy or ethoxyalkyl group, and epoxides of formula (II) wherein R?2 and R3¿ independently of each other mean hydrogen or an alkyl or alkenyl radical which can additionally carry C¿1? to C4 carboxylic acid alkylester groups and can be interrupted by non-adjacent oxygen atoms, in which the total number of carbon atoms of the two radicals R?2 and R3¿ has to be between 4 and 60, said mixture containing 50 to 100 wt % monoalkylation products and 0 to 50 wt % higher alkylation products, at least one of the possible regio-isomer monoalkylation products being present in an amount of at least 30 wt % if n equals 6 or at least 40 wt % if n equals 5, in each case relative to the total of all the monoalkylation products formed.

Description

Mixture of alkylation products of acetalized monosaccharides with epoxides Description

The present invention relates to a mixture of alkylation products of monosaccharides acetalized in the 1-position with long-chain epoxides, processes for their preparation and their use as surfactants or emulsifiers in detergents, cleaning products or personal care products.

In the surfactant and emulsifier sector, mostly nonionic surface-active substances based on renewable raw materials have increasingly come to the fore in recent years. Such substances generally have good biodegradability, low toxicity and therefore good environmental compatibility. An important group of such nonionic surfactants

Alkylglycosides in which the long-chain hydrophobic alkyl radical is attached directly to the hydrophilic carbohydrate part of the molecule in the 1-position by means of an acetal bond. Such products already largely meet the expectations placed on them, but they still prove to be in need of improvement in some properties, such as the foam and wetting capacity, the interfacial or surface tension or the fat loss capacity.

US Pat. No. 4,011,389 discloses a mixture of reaction products of long-chain 1,2-epoxyalkanes with glycosides which carry an acetally bound short-chain alkyl, hydroxyalkyl or alkoxyalkyl group in the 1-position. The molar ratio of glycosides to 1,2-epoxyalkanes in the reaction is 4: 1 to 0.83: 1. The 1,2-epoxyalkanes can react with any free hydroxyl group in glycoside. This results in a more or less statistical mixture of the possible reaction products, in which no enrichment of a particular species can be observed. The mixture thus obtained is recommended as a nonionic surfactant for a wide variety of uses.

The object of the present invention was to provide nonionic surfactants or emulsifiers based on renewable raw materials with improved application properties. Accordingly, a mixture of alkylation products of monosaccharides acetalized in the 1-position by the radical R ^{1 was of} the general formula I

(C _n H _2n-1 O _n ) - R ¹ {I) in which n represents the number 5 or 6 and R ^{1 is} a C ₁ - to C ₄ -alkyl group, a mono- or dihydroxy-C ₁ - to C ₃ -alkyl group or a methoxy or ethoxy-C ₁ - to C ₃ -alkyl group, with epoxides of the general formula II

in which R ² and R ³ independently of one another are hydrogen or an alkyl or alkenyl radical which additionally carry C ₁ - to C ₄ -alkyl carboxylate groups and can be interrupted by non-adjacent oxygen atoms, the sum of the C atoms of both radicals R ² and R ³ must be 4 to 60, found which contains 50 to 100% by weight of monoalkylation products and 0 to 50% by weight of higher alkylation products, at least one of the possible regioisomeric monoalkylation products in an amount of at least 30% by weight in the case of n = 6 or at least 40% by weight in the case of n = 5, in each case based on the sum of all monoalkylation products formed.

The acetalized monosaccharides I are based on conventional ones

Pentoses (n = 5) or hexoses (n = 6). Aldopentoses such as ribose, arabinose, xylose and lyxose, aldohexoses such as allose, old rose, glucose, mannose, gulose, idose, galactose and talose and ketohexoses such as are preferably used as such carbohydrates

Fructose. Of these, mannose, glucose, galactose and fructose are preferred. Glucose is particularly preferred. The naturally occurring carbohydrates of the D series are normally considered, but representatives of the L series can also be used.

The radical R ¹ denotes in particular methyl, ethyl, n-propyl, isopropyl, n-butyl or isobutyl, but also are

2-hydroxyethyl, 2-hydroxypropyl, glyceryl, 2-methoxyethyl and Suitable for 2-ethoxyethyl. The meaning methyl is particularly preferred for R ¹ .

The method of preparation of the acetalized monosaccharides I, which exist in both anomeric forms, i.e. in α- or β-form, for example from the underlying monosaccharide and the corresponding alcohol under acid catalysis, is part of the general specialist knowledge and therefore does not need to be elaborated on here.

The following are particularly suitable as long-chain epoxides II:

(a) terminal epoxides, ie those in which R ^{2 is} a C ₄ to C ₃₃ alkyl or alkenyl radical and R ^{3 is} hydrogen;

(b) central epoxides, ie those in which R ² and R ³

each represent a C ₄ to C ₃₀ alkyl or alkenyl radical, it being possible for the two radicals to be the same or different; (C) central epoxyalkane carboxylic acid C ₁ - to C ₄ alkyl esters, in particular the corresponding epoxides of fatty acid alkyl esters such as epoxidized methyl oleic acid esters, ie those

Compounds in which one of the radicals R ² or R ^{3 is} a C ₄ to C ₃₀ alkyl or alkenyl radical and the other is a C ₄ to C ₃₀ alkyl or alkenyl radical which is preferably a carboxylic acid C ₁ - to C ₄ alkyl ester grouping means;

(d) Glycidyl ether, ie those compounds in which R ^{2 is} a C ₃ to C ₂₉ alkyl or alkenyloxymethyl radical and R ^{3 is} hydrogen.

A long-chain radical R ² or R ³ represents branched or preferably linear alkyl or alkenyl having 4 to 30 C atoms, in particular 6 to 20 C atoms, especially 8 to 16 C atoms.

With a chain length of 9 to 14 carbon atoms for R ² or R ³ , an optimum in the application properties is often achieved, since the optimal ratio between hydrophobic and hydrophilic parts of the molecule is evidently present.

The following alkyl and alkenyl groups are listed as examples of linear long-chain radicals R ² and R ³ : n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tπdecyl, n-tetradecyl, n-pentadecyl, n- Hexadecyl, n-heptadecyl, n-octadecyl, eicosyl, hexadec-7-enyl, hexadeca-7, 10-dienyl and hexadeca-7,10,13-tπenyl.

Mixtures of different radicals R ² or R ³ can also occur, for example mixtures of n-decyl and n-dodecyl or n-dodecyl and n-tetradecyl. As C ₁ to C ₄ alkyl ester radicals in (c) are n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl and in particular

Consider methyl and ethyl.

Alkylation products are products in which one or more of the free hydroxyl groups in the acetalized monosaccharides I have been replaced by groups of the formula -O-CHR ³ -CH (OH) -R ² . When one hydroxyl group is replaced, there are monoalkylation products, and when two or more hydroxyl groups are replaced, higher alkylation products are present. In the case of pentose-based acetalized monosaccharides I (n = 5) exist

3 regioisomeric monoalkylation products, on hexoses

based acetalized monosaccharides I (n = 6) exist

4 regioisomeric monoalkylation products, in the case of aldohexoses such as glucose these are the 2-, 3-, 4- and 6-alkylation products (2-, 3-, 4- and 6- (2'-hydroxyalkyl) glycosides).

For the purposes of the present invention, the mixture described is enriched with at least one, in particular one or two, of the respective regioisomeric monoalkylation products. Under

Enrichment is an amount of at least 30% by weight, preferably at least 34% by weight, in particular at least 38% by weight in the case n = 6 and of at least 40% by weight, preferably at least 45% by weight, in particular at least 50% by weight in the case n = 5, in each case based on the sum of all monoalkylation products formed.

In extreme cases, the enrichment can go so far that a regioisomeric monoalkylation product is present in the mixture according to the invention in practically pure form, that is to say 95 95% by weight. However, such high levels of enrichment can generally only be achieved by additional complex cleaning or work-up steps such as chromatographic techniques, so that they are normally no longer interesting for large-scale production of the mixture according to the invention. The application properties of the practically pure regioisomeric monoalkylation products usually exceed the already excellent application properties of the, as above described, at least 30 wt .-% or 40 wt .-% enriched monoalkylation products.

With aldohexoses, especially with glucose, they are

4- (2'-hydroxyalkyl) glycosides and especially the 6- (2'-hydroxyalkyl) glycosides are the most technically effective species.

A mixture according to the invention is therefore preferred which is enriched in these two species or in one of them. The mixture according to the invention can contain up to 50% by weight, in particular up to 35% by weight, especially up to 20% by weight, based on the mixture as a whole, of higher alkylation products. These levels of higher alkylation products can have advantages in certain applications because they have a foam-suppressing effect.

The mixture according to the invention can be prepared in a simple manner by reacting the acetalized monosaccharides I with the epoxides II in a molar ratio of 5: 1 to 25: 1, in particular 6: 1 to 15: 1. Through the excess

Glycoside I is presumably directed the reaction in such a way that a certain one or more certain regioisomeric monoalkylation products preferentially form, in the case of aldohexose derivatives I these are mostly the 4- and / or 6-alkylation products. Another favorable effect is the only small to nonexistent proportion of higher alkylation products in the mixture according to the invention.

The mixture according to the invention can also be more simple

Be prepared by designing the metering of the epoxides II into the acetalized monosaccharides I in such a way that a stable monosaccharide I-epoxide II emulsion is present during the reaction, i.e. is worked in a heterogeneous phase. In the simplest case, this can be achieved in that the epoxide II in a suitable manner, i.e. finely distributed and with thorough mixing, is continuously introduced into the reaction mixture, for example by slow injection. Pumping systems via an external liquid circuit, into which the epoxy II is fed by means of a liquid jet pump, are particularly effective. In this invention

As a rule, monosaccharide I and epoxide II are prepared in a molar ratio of 0.5: 1 to 5: 1, preferably 1: 1 to 3: 1. To achieve good emulsification of monosaccharide I and epoxide II, customary emulsifiers such as further alkyl glycosides or fatty alcohol ethoxylates or alkyl phenol ethoxylates can be used become. The concentrations of such emulsifiers in the reaction mixture are normally 0.5 to 30% by weight, in particular 1 to 15% by weight. The two measures of the excess procedure on monosaccharide I and the formation of an emulsion can also be combined.

The implementation of the acetalized monosaccharides I with the

Epoxides II is advantageously made without solvent at higher temperatures, for example at 120 to 250 ° C, in particular at 150 to 200 ° C, i.e. in the melt. But you can also work in inert, sufficiently polar solvents at about 80 to 200 ° C. The reaction is more successful if suitable catalysts are used in the usual amounts, e.g. of alcoholates such as potassium tert-butoxide.

To work up such a reaction batch, the crude product is usually in a solvent, e.g. an alcohol or an alcohol-containing solvent mixture, added and a basic or acidic catalyst used, if appropriate, neutralized. Unreacted monosaccharide I can normally be removed by filtration. The mixture according to the invention is then obtained by distilling off the solvent or the solvent mixture. Further purification with further enrichment or isolation of individual species can be carried out using chromatographic techniques. The crude product still containing monosaccharide I can also be used directly for various applications. The mixture according to the invention is used as a surface-active substance, i.e. as a non-ionic surfactant, in detergents and cleaning agents, for example for cleaning processes in technology and household as for textile washing or for cleaning processes in the food sector such as cleaning beverage bottles or in hand dishwashing detergents. It also serves as an emulsifier in personal care products such as skin creams, lotions, gels, skin oils or hair shampoos.

The present invention also relates to detergents, cleaning agents and personal care products which, in addition to the usual constituents, contain 0.5 to 50% by weight, preferably 1 to 30% by weight, of the mixture according to the invention. The usual constituents and composition of detergents and cleaning agents and of personal care products are known to the person skilled in the art and therefore need not be discussed further here. The mixture according to the invention is a nonionic surfactant or emulsifier, which usually has an unusually low interfacial tension, especially against essential oils (for applications in cosmetics as a solubilizer), non-polar oils such as motor oils (for applications in technical cleaners) or fatty oils such as olive oil ( when used in hand dishwashing detergents), which correlates very well with a high fat ablation ability, and effectively lowers the surface tension and has a very low critical micelle formation concentration. It shows a good wetting ability of hard surfaces such as glass, metal, ceramic or plastic, which they are suitable for

Makes detergent suitable. It is still readily soluble in water. As a rule, it has very good wetting power, in particular on textile surfaces, and usually produces little foam during the washing process, in particular with a low content of higher alkylation products, which makes it suitable for textile detergents, in particular powder detergents.

The mixture according to the invention is particularly suitable as an emulsifier or solubilizer for essential oils. Essential oils such as spruce needle oil, rosemary oil or pine needle oil are dissolved in water or, for example, in aqueous ethanol at a suitable weight ratio of the mixture according to the invention to ethereal oil, usually 0.1: 1 to 10: 1, in particular 1: 1 to 5: 1, water-clear solubilized. The emulsions produced in this way are stable almost indefinitely. Such aqueous or aqueous-alcoholic formulations of essential oils are used, for example, in cosmetic or pharmaceutical preparations. As a rule, washing, cleaning and personal care products

Obtaining mixtures of nonionic and anionic and optionally further surface-active substances, the mixture according to the invention is a valuable building block for setting a certain property profile in these agents.

The mixture according to the invention is based on pure monosaccharides and thus does not have the known problems which occur with alkyl polyglycosides in the production and use in terms of purity, color or reproducibility of the composition.

The mixture according to the invention is biodegradable, non-toxic and therefore has good environmental compatibility. Manufacturing examples

Example 1 38.8 g (200 mmol) of anhydrous α-methylglucoside were melted under a nitrogen atmosphere at a bath temperature of 180 ° C., 1.12 g (10 mmol) of potassium tert-butoxide were added and the mixture was dissolved with stirring. Then 3.68 g was added dropwise

(20 mmol) 1,2-epoxydodecane to the clear carbohydrate melt. After the dropping was complete, it was completely

Sales stirred further at 180 ° C.

For working up, the cooled reaction mixture was taken up in methanol and neutralized with glacial acetic acid. To separate the unreacted methyl glucoside, diethyl ether was added and the solid was filtered off. After the solvents were distilled off, a yellowish syrup was obtained, which contains the corresponding monoalkylation products as the main constituent in the following

Weight ratio contained:

20% by weight of 2- (2'-hydroxydodecyl) methyl glucoside

16% by weight of 3- (2'-hydroxydodecyl) methyl glucoside

30% by weight of 4- (2'-hydroxydodecyl) methyl glucoside

34% by weight 6- (2'-hydroxydodecyl) methyl glucoside

General working instructions for the further enrichment or isolation of individual species

To remove the higher alkylation products, one works by flash chromatography with ethyl acetate / methanol mixtures. The regioisomeric monoalkylation products are separated by flash chromatography using methanol / dichloromethane / chloroform. Suitable protective group technology (such as acetalization and benzylation) can simplify the separation. The protective groups are removed after cleaning according to usual

Methods removed.

Examples 2 to 5 The mixture of the 4 monoalkylation products from Example 1 was separated into the 4 individual species according to the above general working instructions, which were then each present in approximately 95% by weight purity (Example 2: 2 isomer, Example 3: 3 -Isomer, example 4: 4-isomer, example 5: 6-isomer). Example 6

485.5 g (2.5 mol) of anhydrous α-methylglucoside were melted at 195 ° C. and 28.1 g (0.25 mol) of potassium tert-butoxide were added. The melt was pumped around (under a nitrogen atmosphere), 460 g (2.5 mol) of 1,2-epoxydodecane being injected into the circuit over a period of 10 hours in such a way that a stable suspension was formed during the reaction. 875 g of a dark syrup were obtained as the crude product. Working up was carried out as in Example 1. The yellowish syrup obtained had the following composition:

65% by weight of mono- (2'-hydroxydodecyl) methylglucoside (of which 49% by weight of 6- (2'-hydroxydodecyl) methylglucoside

21% by weight of 4- (2'-hydroxydodecyl) methyl glucoside

17% by weight of 3- (2'-hydroxydodecyl) methyl glucoside

13% by weight of 2- (2'-hydroxydodecyl) methylglucoside) and 35% by weight mainly higher (2'-hydroxydodecyl) methylglucoside and other by-products.

Application properties The table below shows the application data regarding interfacial tension γ against (i) motor oil (at 25 ° C) and against (ii) lard (at 60 ° C) (each 1 g / l with a contact time of 30 min), more critical Micelle concentration (CMC) (at 25 ° C) and wetting (NV) on cotton (1 g / l, 23 ° C).

In terms of application technology, the 2-isomer (example 2) behaves similarly to the 3-isomer (example 3), the 4-isomer (example 4) behaves similarly to the 6-isomer in terms of application technology

(Example 5).

Example 7

Aqueous formulation for an essential oil 1 g of rosemary oil and 3 g of the mixture from Example 6 were mixed with 96 g of water and stirred at room temperature for 5 min.

A clear liquid was obtained which remained stable over a period of at least 6 weeks.

Claims

claims

1. Mixture of alkylation products from the 1-position

by the radical R ¹ acetalized monosaccharides of the general formula I

(C _n H2 _n-1 O _n ) - R ¹ (I) in which n stands for the number 5 or 6 and

R ^{1 is} a C ₁ to C ₄ alkyl group, a mono- or

Dihydroxy-C ₁ - to C ₃ -alkyl group or a methoxy or ethoxy-C ₁ - to C ₃ -alkyl group, with epoxides of the general formula II i

in which R ² and R ³ independently of one another are hydrogen or an alkyl or alkenyl radical which additionally carry C ₁ -C ₄ -alkyl carboxylate groups and can be interrupted by non-adjacent oxygen atoms, the sum of the C atoms from both residues R ² and R ³

Must be 4 to 60, containing 50 to 100% by weight of monoalkylation products and 0 to 50% by weight of higher alkylation products, at least one of the possible regioisomeric monoalkylation products in an amount of at least 30% by weight in the case n = 6 or at least 40% by weight in the case n = 5, in each case based on the sum of all monoalkylation products formed.

2. Mixture according to claim 1, wherein corresponding acetals of mannose, glucose, galactose or fructose are used as acetalized monosaccharides I.

3. Mixture according to claim 1 or 2, wherein the radical R ¹ denotes methyl, ethyl, n-propyl, isopropyl, n-butyl or isobutyl.

4. Mixture according to claims 1 to 3, wherein (a) R ^{2 is} C ₄ to C ₃₀ alkyl or alkenyl and R ^{3 is} hydrogen or

(b) R ² and R ³ each represent a C ₄ to C ₃₀ alkyl or alkenyl radical or

(c) one of the radicals R ² or R ^{3 is} a C ₄ to C ₃₀ alkyl or alkenyl radical and the other is a C ₄ to C ₃₀ alkyl or alkenyl radical which is a carboxylic acid C ₁ to C ₄ alkyl ester group carries, means or

(d) R ^{2 is} C ₃ to C ₂₉ alkyl or alkenyloxymethyl and R ^{3 is} hydrogen.

5. A process for the preparation of a mixture according to claims 1 to 4, characterized in that the acetalized monosaccharides I with the epoxides II in molar

Ratio of 5: 1 to 25: 1.

6. A process for the preparation of a mixture according to claims 1 to 4, characterized in that the metered addition of the epoxides II to the acetalized monosaccharides I is designed such that a stable monosaccharide I-epoxide II emulsion is present during the reaction.

7. Use of a mixture according to claims 1 to 4 as a surface-active substance in washing and cleaning agents.

8. Use of a mixture according to claims 1 to 4 as an emulsifier in personal care products.

9. Use of a mixture according to claims 1 to 4

as a solubilizer for essential oils in aqueous or aqueous alcohol formulations for cosmetic or pharmaceutical preparations.

10. washing, cleaning and personal care products containing, in addition to the usual constituents, 0.5 to 50% by weight of a mixture according to claims 1 to 4. Mixture of alkylation products of acetalized monosaccharides with epoxides Summary

Mixture of alkylation products of monosaccharides I acetalized in the 1-position by the radical R ¹

(C _n H _2n-1 O _n ) -R ¹ (I) in which n represents the number 5 or 6 and

R ^{1 is} a C ₁ to C ₄ alkyl group, a mono- or dihydroxy C ₁ to C ₃ alkyl group or a methoxy or ethoxy C ₁ to bis

C ₃ alkyl group, with epoxides II

where R ² and R ³ independently of one another are hydrogen or an alkyl or alkenyl radical which additionally carry carboxylic acid C ₁ -C ₄ -alkyl ester groups and can be interrupted by non-adjacent oxygen atoms, the sum of the C atoms being from both radicals R ² and R ³ must be 4 to 60, containing 50 to 100% by weight of monoalkylation products and 0 to 50% by weight of higher alkylation products, at least one of the possible regioisomeric monoalkylation products in an amount of at least 30% by weight. % in the case n = 6 or at least 40% by weight in the case n = 5, in each case based on the sum of all monoalkylation products formed.