EP0817827B1 - Process for producing aqueous surfactant concentrates - Google Patents

Description

Field of the Invention

The invention relates to a process for the production of aqueous Surfactant concentrates containing selected sugar surfactants and Betaines, which are characterized by improved application properties award.

State of the art

Sugar surfactants, such as, for example, alkyl oligoglycosides, in particular alkyl oligoglucosides, are nonionic surfactants which, due to their excellent detergent properties and high ecotoxicological compatibility, are becoming increasingly important. Preparation and use of these substances have been presented just recently in a number of review articles, one of which is representative of the articles by H. Hensen in Skin Care Forum, (Oct 1992) 1, and D.Balzer N.Ripke in soap Oil-fat waxes 118, 894 (1992) and B.Brancq in soap-oil-fat waxes 118, 905 (1992) are to be mentioned. The same applies to a second group of sugar surfactants, namely the fatty acid N-alkylpolyhydroxyalkylamides and preferably fatty acid N-alkylglucamides.

A large number of binary mixtures of sugar surfactants of the type mentioned with other surfactants are known from the prior art. Among these surfactant compounds, combinations of sugar surfactants, in particular alkyl oligoglucosides with betaines, play a special role, as a synergistic increase in the foam and cleansing power and skin-cosmetic tolerance are observed over a wide mole fraction. For example, a hand dishwashing detergent is known from German patent applications DE-A1 4234487 (Henkel) which, in addition to alkyl glucosides and betaines, also contains fatty alcohol sulfates and fatty alcohol ether sulfates. According to the teaching of DE-A1 4311114 (Henkel), mixtures of alkyl glucosides, betaines and selected fatty alcohol polyglycol ethers can also be used for the same purpose. Finally, DE-A1 4009616 (Henkel) discloses liquid personal cleansing agents which, in addition to alkyl glucosides and betaines, contain protein fatty acid condensates.

EP-A-0 728 836 is state of the art under Article 54 (3) EPC and describes sugar surfactant concentrates with solids contents from 25 to 50% by weight, which are also acidic can.

However, the prior art means in all cases by more or less diluted aqueous solutions, while targeting a manufacturer of alkyl glucoside / betaine mixtures must be highly concentrated products manufacture that is clear in terms of inventory Offer advantages. The manufacture of such concentrates is however, it has a number of disadvantages: mixtures of alkyl glucosides and betaines, which are produced in are generally alkaline, are at solids contents in the range from 40 to 60% by weight viscous and often cloudy. They also show a not always satisfactory Storage stability, i.e. over time, the viscosity increase further due to the formation of liquid crystalline gel phases and / or the products crystallize. This admittedly leads to a very considerable impairment of the economic benefits of such concentrates.

Accordingly, the complex object of the invention has been to a process for the preparation of binary surfactant concentrates to make available that free of the described Disadvantages is.

Description of the invention

(a1) Alkyl- und/oder Alkenyloligoglykoside und/oder

(a2) Fettsäure-N-alkylpolyhydroxyalkylamide und

(b) Betaine

im Gewichtsverhältnis (a) : (b) von 10 : 90 bis 90 : 10, das sich dadurch auszeichnet, daß man die Konzentrate auf einen pH-Wert im Bereich von 3,5 bis 6 und vorzugsweise 4 bis 6 einstellt.The invention relates to a process for the preparation of aqueous surfactant concentrates with a solids content of 55 to 65 wt .-%, containing

(a1) alkyl and / or alkenyl oligoglycosides and / or

(a2) fatty acid N-alkyl polyhydroxyalkylamides and

(b) betaines

in a weight ratio (a): (b) of 10:90 to 90:10, which is characterized in that the concentrates are adjusted to a pH in the range from 3.5 to 6 and preferably 4 to 6.

Surprisingly, it has been found that mixtures of sugar surfactants and betaines, which are usually alkaline The setting is viscous and cloudy, in a simple way become fluid and clear when you check the pH of the mixtures lowered into the acidic range. By this measure the storage stability of the products also becomes positive influenced, i.e. the concentrates show even with longer ones Storage a constant low viscosity and have less tendency to crystallize. The invention also includes the knowledge that one can by retrospectively pH adjustment of viscous surfactant concentrates lower their viscosity and eliminate turbidity.

Alkyl and / or alkenyl oligoglycosides

Alkyl and alkenyl oligoglycosides are known substances which follow the formula (I) (I) R ¹ O- [G] _p in which R ^{1 is} an alkyl and / or alkenyl radical having 4 to 22 carbon atoms, G is a sugar radical having 5 or 6 carbon atoms and p is a number from 1 to 10, and can be obtained by the relevant preparative organic chemistry processes. Representative of the extensive literature, reference is made here to the documents EP-A1-0 301 298 and WO 90/3977 .

The alkyl and / or alkenyl oligoglycosides can differ from Aldoses or ketoses with 5 or 6 carbon atoms, preferably derive the glucose. The preferred alkyl and / or alkenyl oligoglycosides are thus alkyl and / or alkenyl oligoglucosides.

The index number p in the general formula (I) indicates the degree of oligomerization (DP degree), ie the distribution of mono- and oligoglycosides, and stands for a number between 1 and 10. While p in a given compound must always be an integer and here can assume the values p = 1 to 6 in particular, the value p for a certain alkyl oligoglycoside is an analytically determined arithmetic parameter, which usually represents a fractional number. Alkyl and / or alkenyl oligoglycosides with an average degree of oligomerization p of 1.1 to 3.0 are preferably used. From an application point of view, preference is given to those alkyl and / or alkenyl oligoglycosides whose degree of oligomerization is less than 1.7 and in particular between 1.2 and 1.4.

The alkyl or alkenyl radical R ¹ can be derived from primary alcohols having 4 to 11, preferably 8 to 10, carbon atoms. Typical examples are butanol, capronic alcohol, caprylic alcohol, capric alcohol and undecyl alcohol and their technical mixtures, such as are obtained, for example, in the hydrogenation of technical fatty acid methyl esters or in the course of the hydrogenation of aldehydes from Roelen's oxosynthesis. Alkyl oligoglucosides of chain length C ₈ -C ₁₀ (DP = 1 to 3) are preferred, which are obtained as a preliminary step in the separation of technical C ₈ -C ₁₈ coconut fatty alcohol by distillation and with a proportion of less than 6% by weight of C ₁₂ - Alcohol can be contaminated and alkyl oligoglucosides based on technical C _9/11 oxo alcohols (DP = 1 to 3).

The alkyl or alkenyl radical R ¹ can also be derived from primary alcohols having 12 to 22, preferably 12 to 14, carbon atoms. Typical examples are lauryl alcohol, myristyl alcohol, cetyl alcohol, palmoleyl alcohol, stearyl alcohol, isostearyl alcohol, oleyl alcohol, elaidyl alcohol, petroselinyl alcohol, arachyl alcohol, gadoleyl alcohol, behenyl alcohol, erucyl alcohol, and their technical mixtures, which can be obtained as described above. Alkyl oligoglucosides based on hardened C _12/14 coconut alcohol with a DP of 1 to 3 are preferred.

Fatty acid N-alkyl polyhydroxyalkylamides

in der R²CO für einen aliphatischen Acylrest mit 6 bis 22 Kohlenstoffatomen, R³ für Wasserstoff, einen Alkyl- oder Hydroxyalkylrest mit 1 bis 4 Kohlenstoffatomen und [Z] für einen linearen oder verzweigten Polyhydroxyalkylrest mit 3 bis 12 Kohlenstoffatomen und 3 bis 10 Hydroxylgruppen steht.Fatty acid N-alkylpolyhydroxyalkylamides of the formula (I) ,

in the R ² CO for an aliphatic acyl radical having 6 to 22 carbon atoms, R ³ for hydrogen, an alkyl or hydroxyalkyl radical with 1 to 4 carbon atoms and [Z] for a linear or branched polyhydroxyalkyl radical with 3 to 12 carbon atoms and 3 to 10 hydroxyl groups stands.

The fatty acid N-alkyl polyhydroxyalkylamides are known substances which can usually be obtained by reductive amination of a reducing sugar with ammonia, an alkylamine or an alkanolamine and subsequent acylation with a fatty acid, a fatty acid alkyl ester or a fatty acid chloride. With regard to the process for their preparation Patents US US 1,985,424, US 2,016,962 and US 2,703,798 as well as International Patent Application WO 92/06984, reference is made to the. An overview of this topic by H. Kelkenberg can be found in Tens. Surf.Det. 25 , 8 (1988).

The fatty acid N-alkylpolyhydroxyalkylamides are preferably derived from reducing sugars having 5 or 6 carbon atoms, in particular from glucose. The preferred fatty acid N-alkylpolyhydroxyalkylamides are therefore fatty acid N-alkylglucamides as represented by the formula (III):

The preferred fatty acid N-alkylpolyhydroxyalkylamides used are glucamides of the formula (III) in which R ^{3 is} hydrogen or an alkyl group and R ² CO is the acyl radical of caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, palmoleic acid, stearic acid, Isostearic acid, oleic acid, elaidic acid, petroselinic acid, linoleic acid, linolenic acid, arachic acid, gadoleic acid, behenic acid or erucic acid or their technical mixtures. Fatty acid N-alkylglucamides of the formula (III) which are obtained by reductive amination of glucose with methylamine and subsequent acylation with lauric acid or C _12/14 coconut fatty acid or a corresponding derivative are particularly preferred. Furthermore, the polyhydroxyalkylamides can also be derived from maltose and palatinose.

Betaine

Betaines are known surfactants which are predominantly produced by carboxyalkylation, preferably carboxymethylation, of aminic compounds. The starting materials are preferably condensed with halocarboxylic acids or their salts, in particular with sodium chloroacetate, one mol of salt being formed per mole of betaine. Furthermore, the addition of unsaturated carboxylic acids such as acrylic acid is also possible. Regarding the nomenclature and in particular the distinction between betaines and "real" amphoteric surfactants, reference is made to the contribution by U.Ploog in Seifen-Öle-Fette-Wwachs, 198, 373 (1982) . Further overviews on this topic can be found for example by A. O'Lennick et al. in HAPPI, Nov. 70 (1986) , S. Holzman et al. in Tens.Det. 1986 , 23: 309 , R.Bibo et al. in Soap Cosm.Chem.Spec. Apr. 46 (1990) and P.Ellis et al. in Euro Cosm. 1, 14 (1994) .

in der R⁴ für Alkyl- und/oder Alkenylreste mit 6 bis 22 Kohlenstoffatomen, R⁵ für Wasserstoff oder Alkylreste mit 1 bis 4 Kohlenstoffatomen, R⁶ für Alkylreste mit 1 bis 4 Kohlenstoffatomen, n für Zahlen von 1 bis 6 und X für ein Alkali- und/oder Erdalkalimetall oder Ammonium steht.Examples of suitable betaines are the carboxyalkylation products of secondary and in particular tertiary amines which follow the formula (IV)

in which R ⁴ for alkyl and / or alkenyl radicals with 6 to 22 carbon atoms, R ⁵ for hydrogen or alkyl radicals with 1 to 4 carbon atoms, R ⁶ for alkyl radicals with 1 to 4 carbon atoms, n for numbers from 1 to 6 and X for a Alkali and / or alkaline earth metal or ammonium.

Typical examples are are the carboxymethylation products of hexylmethylamine, hexyldimethylamine, octyldimethylamine, decyldimethylamine, dodecylmethylamine, dodecyldimethylamine, Dodecylethylmethylamin, C12 / 14-cocodimethylamine, myristyldimethylamine, cetyldimethylamine, stearyldimethylamine, stearyl, oleyl, C _16/18 tallow alkyl dimethyl amine and technical mixtures thereof.

in der R⁷CO für einen aliphatischen Acylrest mit 6 bis 22 Kohlenstoffatomen und 0 oder 1 bis 3 Doppelbindungen, m für Zahlen von 1 bis 3 steht und R⁵, R⁶, n und X die oben angegebenen Bedeutungen haben.Carboxyalkylation products of amidoamines which follow the formula (V) are also suitable,

in which R ⁷ CO represents an aliphatic acyl radical having 6 to 22 carbon atoms and 0 or 1 to 3 double bonds, m represents numbers from 1 to 3 and R ⁵ , R ⁶ , n and X have the meanings given above.

Typical examples are reaction products of fatty acids having 6 to 22 carbon atoms, namely caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, palmoleic acid, stearic acid, isostearic acid, oleic acid, elaidic acid, petroselinic acid, linoleic acid, linolenic acid, elaeostearic acid, gadoleic acid and arachic acid, arachic acid and their technical mixtures, with N, N-dimethylaminoethylamine, N, N-dimethylaminopropylamine, N, N-diethylaminoethylamine and N, N-diethylaminopropylamine, which are condensed with sodium chloroacetate. It is preferred to use a condensation product of C _8/18 coconut fatty acid N, N-dimethylaminopropylamide with sodium chloroacetate.

in der R⁸ für einen Alkylrest mit 5 bis 21 Kohlenstoffatomen, R⁹ für eine Hydroxylgruppe, einen OCOR⁸- oder NHCOR⁸-Rest und m für 2 oder 3 steht. Auch bei diesen Substanzen handelt es sich um bekannte Stoffe, die beispielsweise durch cyclisierende Kondensation von 1 oder 2 Mol Fettsäure mit mehrwertigen Aminen wie beispielsweise Aminoethylethanolamin (AEEA) oder Diethylentriamin erhalten werden können. Die entsprechenden Carboxyalkylierungsprodukte stellen Gemische unterschiedlicher offenkettiger Betaine dar.Furthermore, suitable starting materials for the betaines to be used in accordance with the invention are also imidazolines which follow the formula (VI)

in which R ^{8 is} an alkyl radical having 5 to 21 carbon atoms, R ^{9 is} a hydroxyl group, an OCOR ⁸ or NHCOR ⁸ radical and m is 2 or 3. These substances are also known substances which can be obtained, for example, by cyclizing condensation of 1 or 2 moles of fatty acid with polyhydric amines such as, for example, aminoethylethanolamine (AEEA) or diethylene triamine. The corresponding carboxyalkylation products are mixtures of different open-chain betaines.

Typical examples are condensation products of the above-mentioned fatty acids with AEEA, preferably imidazolines based on lauric acid or again C _12/14 coconut fatty acid, which are subsequently betainized with sodium chloroacetate.

Surfactant concentrates

The surfactant concentrates are aqueous solutions or pastes with a solids content of 55 to 65 % By weight. Components (a) and (b) are 90:10 in the weight ratio concentrates to 10:90, preferably 80:20 to 20:80 and in particular 60: 40 to 40: 60 included.

The preparation of the surfactant compounds can be done in different ways Ways. For example, it is possible diluted Mixing solutions of sugar surfactants and betaines and then concentrate. It is cheaper, of course, to mix the concentrates and in this way a cumbersome Avoid removing water from the mixtures. Eventually the concentrates fall off during manufacture the betaines immediately when you quaternize the tertiary amines on which the betaines are based in the presence the aqueous sugar surfactant as a solvent. The The time at which the pH value is set is not critical. It is even possible to add viscous, cloudy concentrates later in flawless products from an application technology perspective to convict. The pH is adjusted preferably by adding mineral acids such as Hydrochloric acid, sulfuric acid or preferably phosphoric acid or organic acids such as lactic acid, citric acid and the like. For the same purpose also come at room temperature liquid fatty acids with 8 to 18, preferably 12 to 14 carbon atoms such as lauric acid or oleic acid in question.

Industrial applicability

By lowering the pH value, concentrates of Sugar surfactants and betaines over a wide range of breakwaters provide one for handling advantageously have low viscosity, are clear and a have increased storage stability. The concentrates are suitable themselves for the production of surface-active agents such as in particular manual dishwashing detergents and hair shampoos.

The following examples are intended to be the subject of the invention explain in more detail without restricting it.

Examples I. Surfactants used

A1) C _8/10 alkyl oligoglucoside (Plantaren ^(R) APG 225)

A2) C _12/16 alkyl oligoglucoside (Plantaren ^(R) APG 1200)

A3) C _8/16 alkyl oligoglucoside (Plantaren ^(R) APG 2000)

A4) mixture of A1 and A3 (60:40 parts by weight)

A5) mixture of A1 and A3 (80:20 parts by weight)

A6) Mixture of A1 and A3 (75:25 parts by weight)

A7) Mixture of A1 and A3 (50:50 parts by weight)

A8) mixture of A1 and A3 (43:57 parts by weight)

A9) Coconut fatty acid N-methylglucamide

B1) Betaine based on fatty acid aminoamide ⁽ Dehyton ^(R) PK 45)

B2) Betaine based on tertiary amine (Dehyton ^(R) AB 30)

II. Application results

The mixtures according to Examples 1 to 13 were adjusted to a solids content of 50% by weight and pH = 4 to 6. The viscosity of the products was determined immediately using the Brookfield method (20 ° C., 10 rpm, spindle 2) and after storage at 10 ° C. for a period of 6 months. The condition was assessed visually after a storage time of 10 d. The products according to comparative examples V1 to V4 were treated the same, but adjusted to alkaline. The results are summarized in Table 1 (percentages as% by weight). Viscosity measurements and storage tests E.g. A B A: B FG % pH Vis. [mPa * s] Prod. 1 h 6 m 1 A1 B1 25:75 51 4.2 500 550 clear 2nd A1 B1 50:50 56 5.6 2700 2800 clear 3rd A1 B1 75:25 62 5.7 6150 6175 clear 4th A2 B2 50:50 50 5.0 3000 3100 clear 5 A3 B1 25:75 40 5.0 250 275 clear 6 A3 B1 50:50 44 4.7 1500 1550 clear 7 A3 B1 75:25 47 4.2 1200 1300 clear 8th A4 B1 57:43 54 5.1 3100 3200 clear 9 A5 B1 59:41 55 5.4 3000 3100 clear 10th A6 B1 48:52 53 5.5 2400 2500 clear 11 A7 B1 67:33 55 5.1 3100 3200 clear 12th A8 B1 75:25 56 5.1 2900 3000 clear 13 A9 B1 50:50 50 5.0 1200 1250 clear V1 A1 B1 50:50 56 10.8 6000 - cloudy V2 A2 B2 50:50 50 9.5 7500 - cloudy V3 A3 B1 75:25 47 11.0 1700 - cloudy V4 A3 B1 50:50 48 10.0 6600 - cloudy

The products according to the method of the invention also have a constant low viscosity after 6 months of storage on and are clear. The comparison products, however, fall already in the production as viscous, cloudy mixtures which either crystallize over the period of storage or thicken further.

Claims (5)

1. A process for the production of water-containing surfactant concentrates with a solids content of 55 to 65% by weight, containing

   (a1) alkyl and/or alkenyl oligoglycosides and/or

   (a2) fatty acid-N-alkyl polyhydroxyalkylamides and

   (b) betaines

   in a ratio by weight of (a) to (b) of 10:90 to 90:10, characterized in that the concentrates are adjusted to a pH value of 3.5 to 6.5.
2. A process as claimed in claim 1, characterized in that alkyl and/or alkenyl oligoglycosides corresponding to formula (I): R¹O-[G]_p where R¹ is an alkyl and/or alkenyl radical containing 4 to 22 carbon atoms, G is a sugar unit containing 5 or 6 carbon atoms and p is a number of 1 to 10,
   are used as component (a1).
3. A process as claimed in claim 1, characterized in that fatty acid-N-alkyl polyhydroxyalkylamides corresponding to formula (II):

   

   in which R²CO is an aliphatic acyl radical containing 6 to 22 carbon atoms, R³ is hydrogen, an alkyl or hydroxyalkyl radical containing 1 to 4 carbon atoms and [Z] is a linear or branched polyhydroxyalkyl radical containing 3 to 12 carbon atoms and 3 to 10 hydroxyl groups,
   are used as component (a2).
4. A process as claimed in claims 1 to 3, characterized in that betaines corresponding to formula (IV):

   

   in which R⁴ represents alkyl and/or alkenyl radicals containing 6 to 22 carbon atoms, R⁵ is hydrogen or alkyl radicals containing 1 to 4 carbon atoms, R⁶ represents alkyl radicals containing 1 to 4 carbon atoms, n is a number of 1 to 6 and X is an alkali and/or alkaline earth metal or ammonium,
   are used as component (b).
5. A process as claimed in claims 1 to 3, characterized in that betaines corresponding to formula (V):

   

   in which R⁷CO is an aliphatic acyl radical containing 6 to 22 carbon atoms and 0 or 1 to 3 double bonds, R⁵ is hydrogen or an alkyl radical containing 1 to 4 carbon atoms, R⁶ is an alkyl radical containing 1 to 4 carbon atoms, m is a number of 1 to 3, n is a number of 1 to 6 and X is an alkali metal and/or alkaline earth metal or ammonium,
   are used as component (b).