CA2007514A1 - Process for the production of alkyl glucosides - Google Patents
Process for the production of alkyl glucosidesInfo
- Publication number
- CA2007514A1 CA2007514A1 CA002007514A CA2007514A CA2007514A1 CA 2007514 A1 CA2007514 A1 CA 2007514A1 CA 002007514 A CA002007514 A CA 002007514A CA 2007514 A CA2007514 A CA 2007514A CA 2007514 A1 CA2007514 A1 CA 2007514A1
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- CA
- Canada
- Prior art keywords
- propylene glycol
- fatty alcohol
- weight
- mol
- alkyl
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07H—SUGARS; DERIVATIVES THEREOF; NUCLEOSIDES; NUCLEOTIDES; NUCLEIC ACIDS
- C07H15/00—Compounds containing hydrocarbon or substituted hydrocarbon radicals directly attached to hetero atoms of saccharide radicals
- C07H15/02—Acyclic radicals, not substituted by cyclic structures
- C07H15/04—Acyclic radicals, not substituted by cyclic structures attached to an oxygen atom of the saccharide radical
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/582—Recycling of unreacted starting or intermediate materials
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Crystallography & Structural Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Biochemistry (AREA)
- Biotechnology (AREA)
- General Health & Medical Sciences (AREA)
- Genetics & Genomics (AREA)
- Molecular Biology (AREA)
- Saccharide Compounds (AREA)
Abstract
Abstract A process for the production of alkyl glucosides In the process which is based on transacetalization with propylene glycol, a saccharide component (B) containing starch or partial starch degradation products is first added to a reaction medium (A) containing at least propylene glycol and an acidic catalyst and, optionally, higher (C8-18) fatty alcohol, which has been heated to 100 to 130°C, resulting initially in the formation of propylene glycol glucoside which is transacetalized with fatty alcohol. The molar ratio of fatty alcohol to propylene glycol is at most 1. Working up by methods known per se gives a product containing a high proportion of C8-18 alkyl monoglucoside which is color-stable in alkaline medium.
Quantities of propylene glycol and fatty alcohol recovered by distillation can be recycled without further working up.
Quantities of propylene glycol and fatty alcohol recovered by distillation can be recycled without further working up.
Description
;~07~S~ ~
Docket Case D 7923 CA
A PROCESS FOR THE PRODUCTION OF ALKYL GLUCOSIDES
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
The invention is a new improved process for the production of alkyl qlucosides by the transacetalization method using propylene glycol.
Renewable raw materials are being used to an increasing extent for the development and production of new surface-active materials which are suitable as industrial surfactants for the production of detergents and cleaning preparations. Hitherto, oleochemical raw materials such as, for example, fatty acid, fatty acid esters and fatty alcohols, have mainly come into consideration for this purpose. Recently, surface-active alkyl glucosides, which are acetals of glucose and fatty alcohols, have acquired interest in this regard. The term alkyl glucoside is intended to encompass alkyl monoglucosides and also alkyl oligoglucosides and alkyl polyglucosides, but especially mixtures of mono- and oligoglucosides.
The term "alkyl" in alkyl glucoside applies to the residue of the corresponding primary alcohols of natural and/or synthetic origin preferably containing C8 to C18 alkyl or alkenyl radicals.
The most important saccharide starting material in practice are the anhydrous polyglucose compounds widely available in nature, of which the individual glucose units are present in ~-glucosidic linkage. The most important natural starting material of this type is starch which is formed worldwide by useful plants of various kinds, for example potatoes, corn, tapioca, rice and the like. Powder-form starches and their partial degradation products, for example in the form of a corresponding, generally highly concentrated glucose syrup, are available as comparatively inexpensiYe starting materials.
The sixties and seventies saw a number of proposals for the production of alkyl glucosides which were concerned in particular with two measures. First, it was proposed not to use the polyanhydroglucose components as such on account of the high - . .. .
,; .. ~, . , )'7~
,ensitivity of polysaccharides to the high temperatures and pressures hitherto required in the production of alkyl glucosides, but instead to degrade this starting material of natural origin to monosaccharide, i.e. to glucose, which could then be subjected to acetalization as an anhydrous material or as glucose hydrate.
The second measure adopted makes use of the fact that lower alcohols and glycols, particularly those having an alkyl chain length in the C3 5 range, lead comparatively easily to the desired acetalization of the monosaccharide. However, the resulting acetals of the monosaccharide show inadequate surfactant properties. They are converted by transacetalization with the relatively long-chain (Cg18) monofunctional alcohols into the desired alkyl glucoside reaction products having surface-active properties. This apparently comparatively simple method of production is attended in practice by numerous difficulties, such as the production of light-colored, color-stable alkyl glucosides which remain color-stable above all in alkaline medium.
RELATED ART
European patent application 102 558 (corresponding to US
4,704,453) describes the production of long-chain alkyl glucoside mixtures by transacetalization of C35 alkyl glucosides. This process starts out from glucose. European patent application 99 133 describes the conversion of saccharides, particularly 2S polysaccharides, such as starch, into glucoside mixtures using alcohols containing at least 3 carbon atoms. In this case, the reaction is said to be carried out in the presence of at least 2 mol water per molar saccharide unit and in the presence of, in particular, acidic catalysts. Preferably, the liquid phase used to disperse the polysaccharide compound additionally contains an alcohol-soluble organic auxiliary solvent. Alkanols containing 3 to 6 carbon atoms and, in particular, 3 or 4 carbon atoms proved to be particularly suitable alcohols for forming the alkyl glucoside compounds. According to European Patent Application 99~83, the lower alkyl glucosides formed in this way may be used as intermediate compounds in the production of surface-active alkyl glucoside compounds, although no particulars of this ~",:'' : -~''.'''''' .
~075~
ubsequent reaction step are provided in the disclosure.
US-PS 3,772,269 describes the production of alkyl glucosides from a saccharide component and relatively long-chain monofunctional alcohols essentially containing C82s alkyl or al~enyl chains b}T the transacetalization method using aliphatic C3 5 glycols, preferably propylene glycol. In a first step, glycol, higher alcohol containing a primary or secondary OH
group, saccharide, preferably glucose, although oligo- or polysaccharides may also be used, and an acidic catalyst are mixed together and the resulting mixture is subsequently heated to reaction temperature which is between 70 and 160C, depending on the components used. The reaction mixture is worked up by methods known E~E se. The products obtained are distinguished by a high content of glycol glucosides or of fatty alcohol glucosides, depending on the process conditions. However, to obtain products having a high content of fatty alcohol glucosides generally meant that a large excess of fatty alcohol over the glycol had to be used. The quality of the products in regard to color and alkali stability is not mentionsd.
The problem addressed by the present invention is to convert the polysaccharides available as natural starting materials in the form of starches or their partial degradation products into surface-active alkyl glucoside compounds in such a way that no intermediate stages have to be isolated and the reaction products show the requisite light color, color stability and, in particular, alkaline color stability.
BRIEF DESCRIPTION OF THE INVENTION
Accordingly, the present invention relates to a process for the production of alkyl glucosides from a saccharide component and relatively long-chain monofunctional alcohols containing C8 18 alkyl or alkenyl chains by the transacetalization method using propylene glycol, characterized in that a saccharide component (B) containing starch or partial starch degradation products is added to a reaction medium (A) containing at least propylene glycol and an acidic catalyst and, optionally, higher fatty alcohol, which has been heated to 100 to 130C, the alcohol ~ontaining a primary OH group and the molar ratio of higher Z~O 75~LL/~
.lcohol to propylene glycol being at most 1.
DETAILED DESC~IPTION OF THE INVENTION
Polysaccharides are particularly useful as the glucose starting material. The preferred polysaccharide for processing by the process according to the invention is starch of any origin and/or partial starch degradation products of the type available in the form of generally highly concentrated aqueous syrup-like products as used herein saccharide component refers to starch or starch partial degradated products.
The useful alcohols comprise monofunctional aliphatic alco-hols, particularly primary C818 alcohols. Preferred alcohols are linear alcohols of natural origin (fatty alcohols), although synthetic primary alcohols, such as for example the so-called oxo alcohols, which contain a per~entage, generally 20 to 40%, of branched isomers containing a 2-methyl group are also suitable.
Accordingly, typical suitable alcohols are decanol, dodecanol, tetradecanol, hexadecanol, octadecanol and 2-methyl undecanol and also mixtures of C10, C12 and C~4 alcohols.
Paratoluenesulfonic acid is preferably used as the acidic catalyst by virtue of its less corrosive effect on apparatus and pipes of steel by comparison with sulfuric acid. However, any acidic compound, including the acids of phosphorus and Lewis acids, which catalyze the acetalization reaction between a fatty alcohol and a sugar molecule, are basically suitable as catalysts.
In one preferred embodiment of the process, a reaction medium (A) containing propylene glycol in quantities of 3 to 8 mol per mol saccharide (expressed as anhydroglucose) and an acidic catalyst in a quantity of 0.01 to 0.03 mol per mol of the glucose unit present in the saccharide used is heated to a reaction temperature of 100 to 130C. The saccharide component (B) containing starch or partial starch degradation products is then added to this preheated mixture (A) in such a way that the reaction mixture always remains a clear solution. It has proved to be preferable in terms of process technology to add a saccharide component (B) in which the saccharide is suspended in propylene glycol. Quantities of 2 to 4 mol propylene glycol per s~
- .. . .
~;''.. ~,:'' ', ' ' ~075~4 .ol anhydroglucose units are preferably used. The saccharide component (B) may be added both in portions and also continuously, continuous addition of the saccharide component (B) being the preferred embodiment.
The propylene glycol glucoside obtained as intermediate product does not have to be isolated because water and excess propylene glycol are removed under a reduced pressure of the order of 100 mm Hg with simultaneous introduction of the higher fatty alcohol preferably preheated to 90 to 100C. The fatty alcohol is used in quantities of 3 to 8 mol per mol anhydroglucose units, the molar ratio of fatty alcohol to propylene glycol being at most 1. In one preferred embodiment, the fatty alcohol to be added to the reaction mixture formed by mixing of the (A) and (B) is mixed with 0.5 to 1 mol propylene glycol per mol fatty alcohol which facilitates a synchronous propylene glycol/fatty alcohol exchange.
In another preferred embodiment of the process according to the invention, a mixture containing propylene glycol and the acidic catalyst in the quantities shown above and, in addition, higher fatty alcohol in quantities of 3 to 8 mol per mol anhydroglucose units is used as the reaction medium (A). The saccharide component (B) is added to the heated reaction medium (A) as described above. Water and propylene glycol are then removed by distillation at a temperature of 115 to 120C by reduction of the pressure in stages from 100 to 15 mm Hg. The propylene glycol recovered, which may also contain fatty alcohol, can be recycled.
Accordingly, another preferred embodiment of the process according to the invention is characterized by the use of a reaction medium (A) which contains propylene glycol and catalyst in the quantities shown, but only a portion of the total fatty alcohol to be used. The remaining fatty alcohol is then introduced into the intermediate propylene glycol/glucoside mixture as described above.
The end product obtained by the process according to the invention is purified and worked up by methods known per se as described in detail in the literature cited at the beginning and , . . . .. . . . . . .
7 .. ~ - . ., - - ... .. .
"~" ~
~,~07~
n German patent application 37 23 826.
In the process according to the invention, neutralization of the acid-catalyzed reaction product is preceded by filtration to remove the unreacted saccharide which may then be reused as starting material for another batch.
The acidic catalyst may be neutralized with organic or inorganic basic alkali or, more particularly, alkaline earth compounds, preferably organomagnesium compounds, such as magnesium alcoholates, or inorganic magnesium compounds, such as magnesium oxide or magnesium hydroxide. pH values of at least 8 and preferably of from about 9 to 10 are preferably established. The establishment of these pH values improves the color stability of the surfactant in alkaline medium during storage and in particular during its subsequent processing.
After - another - filtration, the excess fatty alcohol may be distilled off in known product-friendly vacuum distillation units. The use of thin-layer evaporators and/or falling-film evaporators is particularly suitable for this purpose. The fatty alcohol recovered can be returned to the process.
After cooling, the end product of the reaction is a pale yellowish wax-like mass which may advantageously be converted into an aqueous paste having an active-substance content of approximately 60% in the interests of better handling. Where the color of the end product has to satisfy particularly stringent requirements, production of the aqueous paste may be accompanied by bleaching with hydrogen peroxide or an organic peracid or corresponding peracid salts to obtain additional color lightening. A further addition in the form of sodium hydroxide or a sodium hydroxide/citric acid buffer has proved to be appropriate.
The color stability of the product is determined by a simple test. A sample quantity of the product is mixed with water to form an approximately 50% paste to which concentrated sodium hydroxide is added at normal temperature to establish a pH value of about 12 to 13, followed by heating for 60 minutes to lOODC.
In the case of mixtures containing process products, little or no change in color occurs after this treatment. The color values .
~0~
,f the products were determined by the KLETT method (5% solution in water/isopropanol 70 : 25, l cm cell, blue filter). It is possible by this method to simulate long-term storage tests of the product under standard conditions and also methods for further processing of the stored product, in particular to detergents and cleaning preparations, and the associated alkaline conditions. The end products of the process preferably have Klett values of less than 35.
It has been found that the presence of propylene glycol glucoside in the end reaction product can be of advantage so that, in one preferred embodiment, the production process is displaced in such a way that at most 15% by weight propylene glycol glucoside remain in the reaction mixture. The residual content of propylene glycol glucoside may be obtained by premature termination of the transacetalization or by variations in the quantity of distillate obtained during removal of the excess propylene glycol. The presence of the propylene glycol glucoside not only improves the flow properties of the reaction mixture, thereby facilitating the removal of fatty alcohol, it also improves the color and alkaline stability of the end product, so that bleaching of the end product is not absolutely essential.
The present invention also relates to certain alkyl glucoside mixtures as new products obtainable by the process according to the invention. One preferred embodiment contains less than 3% by weight residual fatty alcohol. Another preferred embodiment contains 50 to 65% by weight alkyl monoglucoside, 8 to 15% by weight alkyl diglucoside, 2 to 5~ by weight alkyl triglucoside, at most 3% by weight residual fatty alcohol, 5 to 15% by weight propylene glycol glucoside and 5 to 20% by weight polyglucose. In all the products, the free glucose content is preferably less than 1% by weight.
. .
~7~1~
E X A M P L E S
Example 1 Potato starch was processed by the single-step process according to the invention to a reaction product containing surface-active alkyl glucoside compounds. The following starting materials were used in the quantities shown:
5.77 kg potato starch (water content 18%), corresponding to 4.73 kg starch (anhydrous) and 1.04 kg water 13.80 kg propylene glycol, of which 8.13 kg were in-troduced at the outset and 5.67 kg in admixture with the starch kg Cl2 ~4 fatty alcohol (native basis; mixture of approx. 75% by weight dodecanol and approx. 25%
by weight tetradecanol) 128 g paratoluenesulfonic acid monohydrate 134 g magnesium methylate for neutralization The propylene glycol and C1214 fatty alcohol were introduced together with the catalyst and heated to approximately 120~C.
When that temperature had been reached, the slurry consisting of propylene glycol and potato starch began to be added either continuously or in 3 portions, the next portion being added as soon as the reaction mixture was clear. The addition was terminated after about 50 minutes. To remove the starch moisture, the pressure was reduced (100 mm Hg) immediately after the last addition. 1.7 kg liquid (water and propylene glycol) distilled off.
Another 11 kg liquid (93~ by weight propylene glycol/ 7%
weight C12~4 fatty alcohol) were distilled off at llS to 120-C by reduction of the pressure in stages (100/7S/S0/ 20/15 mm Hg).
It was found to be appropriate in this regard to heat the ascending "cooler" to 80C. The reaction mixture was neutralized with magnesium methylate for 30 minutes at 80~C and adjusted to a pH value of 9 to 10. Undissolved magnesium methylate (residue 100 g) was then filtered off through an 80 ~m filter bag.
The excess fatty alcohol was distilled off in a thin-film evaporator in a vacuum of approximately 1 torr and at a sump ' '; '' ' ' ' - ~07~4 _emperature up to about 160C.
After venting with nitrogen, a sample of the melt was taken for analytical purposes. The C1214 glucoside thus s~nthesized consisted essentially of 56% by weight monoglucoside, 12% by weight diglucoside, 3% by weight triglucoside, 12% by weight polyglucose, 5~ by weight propylene glycol glucoside and 3% by weight residual fatty alcohol. The free glucose content was less than 1% by weight. The OH value was 652. After the melt had been cooled to 100C, 5 5 kg water preheated to 70 to 80C were added and, at the same time, the product was bleached with 0.5%
hydrogen peroxide (based on active substance) for 1 hour at pH
10 (addition of sodium hydroxide).
The product obtained in this way had a Klett value of 10 (after the color stability test: 15). A comparable quality (Klett value 31.7) without subsequent bleaching was shown by only one product in the production of which only 83% of the propylene glycol had been distilled off (see Table 1).
Example 2 Potato starch was processed by the multistage process according to the in~ention to a reaction product containing surface-active alkyl glucoside compounds. The following starting materials were used in the quantities shown:
5.77 kg potato starch (water content 18%) corresponding to 4.73 kg starch (anhydrous) and 1.04 kg water 27.55 kg propylene glycol, of which 8.13 kg were in-troduced at the outset, 5.67 kg in admixture with the starch and 13.75 kg together with the fatty alcohol kg C1214 fatty alcohol (native basis; mixture of approx. 75% by weight dodecanol and 25% by weight tetradecanol) 128 g paratoluenesulfonic acid monohydrate 134 g magnesium methylate for neutralization 35 The propylene glycol and catalyst were initially introduced together and heated to approximately 120C. The slurry of propylene glycol and starch was added as in Example 1. After the ~ ' ~o~
starch moisture (quantity of distillate: 1.7 kg liquid of water and propylene glycol) had been removed, the mixture of propylene glycol and fatty alcohol preheated to 90 to 1004C was introduced in a vacuum of 10~ mm Hg.
The removal of propylene glycol by distillation and the working up of the product mixture were carried out as in Example 1.
Neither the composition nor the quality of the reaction product differed significantly from the data of the product obtained in accordance with Example 1.
In further tests, complete transacetalization was carried out (0% by weight propylene glycol glucoside in the end reaction product).
Where MgO was used as the neutralizing agent, a product of high color quality (Klett value: 15, after the color stability test: 20) was also obtained with subsequent bleaching (see Table 1). :
' ~
.. . . . . . . .
~07~1 4 , - Table 1 Determination of the Klett values of C1214 glycoside (5% solutions in H2O: isopropanol = 70 : 25) .
Neutra- Bleaching % by weight Remarks Klett Color of lizing yes/no propylene value paste agent glycol glucoside Mg(OEt~2 + 5 ~ 10 Light yellow Mg(OEt) 2 + 5 pH 12** 15 Light yellow 1 hour, 100 C, Mg(OEt)2 - lS 83% PG* 31.7 Light yellow distil-led off MgO + - - 15 Light yellow MgO + _ pH 12**, 20 Light yellow 1 hour, NaOH/MgSO4 + - - 27 Light yellow . _ .
NaOH/MgSO4 + - pH 12**, 51.5 Dark yellow 1 hour, .. . .
NaOH + - - 50 Dark yellow ,45 * PG = propylene glycol ** Color stability test .
Docket Case D 7923 CA
A PROCESS FOR THE PRODUCTION OF ALKYL GLUCOSIDES
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
The invention is a new improved process for the production of alkyl qlucosides by the transacetalization method using propylene glycol.
Renewable raw materials are being used to an increasing extent for the development and production of new surface-active materials which are suitable as industrial surfactants for the production of detergents and cleaning preparations. Hitherto, oleochemical raw materials such as, for example, fatty acid, fatty acid esters and fatty alcohols, have mainly come into consideration for this purpose. Recently, surface-active alkyl glucosides, which are acetals of glucose and fatty alcohols, have acquired interest in this regard. The term alkyl glucoside is intended to encompass alkyl monoglucosides and also alkyl oligoglucosides and alkyl polyglucosides, but especially mixtures of mono- and oligoglucosides.
The term "alkyl" in alkyl glucoside applies to the residue of the corresponding primary alcohols of natural and/or synthetic origin preferably containing C8 to C18 alkyl or alkenyl radicals.
The most important saccharide starting material in practice are the anhydrous polyglucose compounds widely available in nature, of which the individual glucose units are present in ~-glucosidic linkage. The most important natural starting material of this type is starch which is formed worldwide by useful plants of various kinds, for example potatoes, corn, tapioca, rice and the like. Powder-form starches and their partial degradation products, for example in the form of a corresponding, generally highly concentrated glucose syrup, are available as comparatively inexpensiYe starting materials.
The sixties and seventies saw a number of proposals for the production of alkyl glucosides which were concerned in particular with two measures. First, it was proposed not to use the polyanhydroglucose components as such on account of the high - . .. .
,; .. ~, . , )'7~
,ensitivity of polysaccharides to the high temperatures and pressures hitherto required in the production of alkyl glucosides, but instead to degrade this starting material of natural origin to monosaccharide, i.e. to glucose, which could then be subjected to acetalization as an anhydrous material or as glucose hydrate.
The second measure adopted makes use of the fact that lower alcohols and glycols, particularly those having an alkyl chain length in the C3 5 range, lead comparatively easily to the desired acetalization of the monosaccharide. However, the resulting acetals of the monosaccharide show inadequate surfactant properties. They are converted by transacetalization with the relatively long-chain (Cg18) monofunctional alcohols into the desired alkyl glucoside reaction products having surface-active properties. This apparently comparatively simple method of production is attended in practice by numerous difficulties, such as the production of light-colored, color-stable alkyl glucosides which remain color-stable above all in alkaline medium.
RELATED ART
European patent application 102 558 (corresponding to US
4,704,453) describes the production of long-chain alkyl glucoside mixtures by transacetalization of C35 alkyl glucosides. This process starts out from glucose. European patent application 99 133 describes the conversion of saccharides, particularly 2S polysaccharides, such as starch, into glucoside mixtures using alcohols containing at least 3 carbon atoms. In this case, the reaction is said to be carried out in the presence of at least 2 mol water per molar saccharide unit and in the presence of, in particular, acidic catalysts. Preferably, the liquid phase used to disperse the polysaccharide compound additionally contains an alcohol-soluble organic auxiliary solvent. Alkanols containing 3 to 6 carbon atoms and, in particular, 3 or 4 carbon atoms proved to be particularly suitable alcohols for forming the alkyl glucoside compounds. According to European Patent Application 99~83, the lower alkyl glucosides formed in this way may be used as intermediate compounds in the production of surface-active alkyl glucoside compounds, although no particulars of this ~",:'' : -~''.'''''' .
~075~
ubsequent reaction step are provided in the disclosure.
US-PS 3,772,269 describes the production of alkyl glucosides from a saccharide component and relatively long-chain monofunctional alcohols essentially containing C82s alkyl or al~enyl chains b}T the transacetalization method using aliphatic C3 5 glycols, preferably propylene glycol. In a first step, glycol, higher alcohol containing a primary or secondary OH
group, saccharide, preferably glucose, although oligo- or polysaccharides may also be used, and an acidic catalyst are mixed together and the resulting mixture is subsequently heated to reaction temperature which is between 70 and 160C, depending on the components used. The reaction mixture is worked up by methods known E~E se. The products obtained are distinguished by a high content of glycol glucosides or of fatty alcohol glucosides, depending on the process conditions. However, to obtain products having a high content of fatty alcohol glucosides generally meant that a large excess of fatty alcohol over the glycol had to be used. The quality of the products in regard to color and alkali stability is not mentionsd.
The problem addressed by the present invention is to convert the polysaccharides available as natural starting materials in the form of starches or their partial degradation products into surface-active alkyl glucoside compounds in such a way that no intermediate stages have to be isolated and the reaction products show the requisite light color, color stability and, in particular, alkaline color stability.
BRIEF DESCRIPTION OF THE INVENTION
Accordingly, the present invention relates to a process for the production of alkyl glucosides from a saccharide component and relatively long-chain monofunctional alcohols containing C8 18 alkyl or alkenyl chains by the transacetalization method using propylene glycol, characterized in that a saccharide component (B) containing starch or partial starch degradation products is added to a reaction medium (A) containing at least propylene glycol and an acidic catalyst and, optionally, higher fatty alcohol, which has been heated to 100 to 130C, the alcohol ~ontaining a primary OH group and the molar ratio of higher Z~O 75~LL/~
.lcohol to propylene glycol being at most 1.
DETAILED DESC~IPTION OF THE INVENTION
Polysaccharides are particularly useful as the glucose starting material. The preferred polysaccharide for processing by the process according to the invention is starch of any origin and/or partial starch degradation products of the type available in the form of generally highly concentrated aqueous syrup-like products as used herein saccharide component refers to starch or starch partial degradated products.
The useful alcohols comprise monofunctional aliphatic alco-hols, particularly primary C818 alcohols. Preferred alcohols are linear alcohols of natural origin (fatty alcohols), although synthetic primary alcohols, such as for example the so-called oxo alcohols, which contain a per~entage, generally 20 to 40%, of branched isomers containing a 2-methyl group are also suitable.
Accordingly, typical suitable alcohols are decanol, dodecanol, tetradecanol, hexadecanol, octadecanol and 2-methyl undecanol and also mixtures of C10, C12 and C~4 alcohols.
Paratoluenesulfonic acid is preferably used as the acidic catalyst by virtue of its less corrosive effect on apparatus and pipes of steel by comparison with sulfuric acid. However, any acidic compound, including the acids of phosphorus and Lewis acids, which catalyze the acetalization reaction between a fatty alcohol and a sugar molecule, are basically suitable as catalysts.
In one preferred embodiment of the process, a reaction medium (A) containing propylene glycol in quantities of 3 to 8 mol per mol saccharide (expressed as anhydroglucose) and an acidic catalyst in a quantity of 0.01 to 0.03 mol per mol of the glucose unit present in the saccharide used is heated to a reaction temperature of 100 to 130C. The saccharide component (B) containing starch or partial starch degradation products is then added to this preheated mixture (A) in such a way that the reaction mixture always remains a clear solution. It has proved to be preferable in terms of process technology to add a saccharide component (B) in which the saccharide is suspended in propylene glycol. Quantities of 2 to 4 mol propylene glycol per s~
- .. . .
~;''.. ~,:'' ', ' ' ~075~4 .ol anhydroglucose units are preferably used. The saccharide component (B) may be added both in portions and also continuously, continuous addition of the saccharide component (B) being the preferred embodiment.
The propylene glycol glucoside obtained as intermediate product does not have to be isolated because water and excess propylene glycol are removed under a reduced pressure of the order of 100 mm Hg with simultaneous introduction of the higher fatty alcohol preferably preheated to 90 to 100C. The fatty alcohol is used in quantities of 3 to 8 mol per mol anhydroglucose units, the molar ratio of fatty alcohol to propylene glycol being at most 1. In one preferred embodiment, the fatty alcohol to be added to the reaction mixture formed by mixing of the (A) and (B) is mixed with 0.5 to 1 mol propylene glycol per mol fatty alcohol which facilitates a synchronous propylene glycol/fatty alcohol exchange.
In another preferred embodiment of the process according to the invention, a mixture containing propylene glycol and the acidic catalyst in the quantities shown above and, in addition, higher fatty alcohol in quantities of 3 to 8 mol per mol anhydroglucose units is used as the reaction medium (A). The saccharide component (B) is added to the heated reaction medium (A) as described above. Water and propylene glycol are then removed by distillation at a temperature of 115 to 120C by reduction of the pressure in stages from 100 to 15 mm Hg. The propylene glycol recovered, which may also contain fatty alcohol, can be recycled.
Accordingly, another preferred embodiment of the process according to the invention is characterized by the use of a reaction medium (A) which contains propylene glycol and catalyst in the quantities shown, but only a portion of the total fatty alcohol to be used. The remaining fatty alcohol is then introduced into the intermediate propylene glycol/glucoside mixture as described above.
The end product obtained by the process according to the invention is purified and worked up by methods known per se as described in detail in the literature cited at the beginning and , . . . .. . . . . . .
7 .. ~ - . ., - - ... .. .
"~" ~
~,~07~
n German patent application 37 23 826.
In the process according to the invention, neutralization of the acid-catalyzed reaction product is preceded by filtration to remove the unreacted saccharide which may then be reused as starting material for another batch.
The acidic catalyst may be neutralized with organic or inorganic basic alkali or, more particularly, alkaline earth compounds, preferably organomagnesium compounds, such as magnesium alcoholates, or inorganic magnesium compounds, such as magnesium oxide or magnesium hydroxide. pH values of at least 8 and preferably of from about 9 to 10 are preferably established. The establishment of these pH values improves the color stability of the surfactant in alkaline medium during storage and in particular during its subsequent processing.
After - another - filtration, the excess fatty alcohol may be distilled off in known product-friendly vacuum distillation units. The use of thin-layer evaporators and/or falling-film evaporators is particularly suitable for this purpose. The fatty alcohol recovered can be returned to the process.
After cooling, the end product of the reaction is a pale yellowish wax-like mass which may advantageously be converted into an aqueous paste having an active-substance content of approximately 60% in the interests of better handling. Where the color of the end product has to satisfy particularly stringent requirements, production of the aqueous paste may be accompanied by bleaching with hydrogen peroxide or an organic peracid or corresponding peracid salts to obtain additional color lightening. A further addition in the form of sodium hydroxide or a sodium hydroxide/citric acid buffer has proved to be appropriate.
The color stability of the product is determined by a simple test. A sample quantity of the product is mixed with water to form an approximately 50% paste to which concentrated sodium hydroxide is added at normal temperature to establish a pH value of about 12 to 13, followed by heating for 60 minutes to lOODC.
In the case of mixtures containing process products, little or no change in color occurs after this treatment. The color values .
~0~
,f the products were determined by the KLETT method (5% solution in water/isopropanol 70 : 25, l cm cell, blue filter). It is possible by this method to simulate long-term storage tests of the product under standard conditions and also methods for further processing of the stored product, in particular to detergents and cleaning preparations, and the associated alkaline conditions. The end products of the process preferably have Klett values of less than 35.
It has been found that the presence of propylene glycol glucoside in the end reaction product can be of advantage so that, in one preferred embodiment, the production process is displaced in such a way that at most 15% by weight propylene glycol glucoside remain in the reaction mixture. The residual content of propylene glycol glucoside may be obtained by premature termination of the transacetalization or by variations in the quantity of distillate obtained during removal of the excess propylene glycol. The presence of the propylene glycol glucoside not only improves the flow properties of the reaction mixture, thereby facilitating the removal of fatty alcohol, it also improves the color and alkaline stability of the end product, so that bleaching of the end product is not absolutely essential.
The present invention also relates to certain alkyl glucoside mixtures as new products obtainable by the process according to the invention. One preferred embodiment contains less than 3% by weight residual fatty alcohol. Another preferred embodiment contains 50 to 65% by weight alkyl monoglucoside, 8 to 15% by weight alkyl diglucoside, 2 to 5~ by weight alkyl triglucoside, at most 3% by weight residual fatty alcohol, 5 to 15% by weight propylene glycol glucoside and 5 to 20% by weight polyglucose. In all the products, the free glucose content is preferably less than 1% by weight.
. .
~7~1~
E X A M P L E S
Example 1 Potato starch was processed by the single-step process according to the invention to a reaction product containing surface-active alkyl glucoside compounds. The following starting materials were used in the quantities shown:
5.77 kg potato starch (water content 18%), corresponding to 4.73 kg starch (anhydrous) and 1.04 kg water 13.80 kg propylene glycol, of which 8.13 kg were in-troduced at the outset and 5.67 kg in admixture with the starch kg Cl2 ~4 fatty alcohol (native basis; mixture of approx. 75% by weight dodecanol and approx. 25%
by weight tetradecanol) 128 g paratoluenesulfonic acid monohydrate 134 g magnesium methylate for neutralization The propylene glycol and C1214 fatty alcohol were introduced together with the catalyst and heated to approximately 120~C.
When that temperature had been reached, the slurry consisting of propylene glycol and potato starch began to be added either continuously or in 3 portions, the next portion being added as soon as the reaction mixture was clear. The addition was terminated after about 50 minutes. To remove the starch moisture, the pressure was reduced (100 mm Hg) immediately after the last addition. 1.7 kg liquid (water and propylene glycol) distilled off.
Another 11 kg liquid (93~ by weight propylene glycol/ 7%
weight C12~4 fatty alcohol) were distilled off at llS to 120-C by reduction of the pressure in stages (100/7S/S0/ 20/15 mm Hg).
It was found to be appropriate in this regard to heat the ascending "cooler" to 80C. The reaction mixture was neutralized with magnesium methylate for 30 minutes at 80~C and adjusted to a pH value of 9 to 10. Undissolved magnesium methylate (residue 100 g) was then filtered off through an 80 ~m filter bag.
The excess fatty alcohol was distilled off in a thin-film evaporator in a vacuum of approximately 1 torr and at a sump ' '; '' ' ' ' - ~07~4 _emperature up to about 160C.
After venting with nitrogen, a sample of the melt was taken for analytical purposes. The C1214 glucoside thus s~nthesized consisted essentially of 56% by weight monoglucoside, 12% by weight diglucoside, 3% by weight triglucoside, 12% by weight polyglucose, 5~ by weight propylene glycol glucoside and 3% by weight residual fatty alcohol. The free glucose content was less than 1% by weight. The OH value was 652. After the melt had been cooled to 100C, 5 5 kg water preheated to 70 to 80C were added and, at the same time, the product was bleached with 0.5%
hydrogen peroxide (based on active substance) for 1 hour at pH
10 (addition of sodium hydroxide).
The product obtained in this way had a Klett value of 10 (after the color stability test: 15). A comparable quality (Klett value 31.7) without subsequent bleaching was shown by only one product in the production of which only 83% of the propylene glycol had been distilled off (see Table 1).
Example 2 Potato starch was processed by the multistage process according to the in~ention to a reaction product containing surface-active alkyl glucoside compounds. The following starting materials were used in the quantities shown:
5.77 kg potato starch (water content 18%) corresponding to 4.73 kg starch (anhydrous) and 1.04 kg water 27.55 kg propylene glycol, of which 8.13 kg were in-troduced at the outset, 5.67 kg in admixture with the starch and 13.75 kg together with the fatty alcohol kg C1214 fatty alcohol (native basis; mixture of approx. 75% by weight dodecanol and 25% by weight tetradecanol) 128 g paratoluenesulfonic acid monohydrate 134 g magnesium methylate for neutralization 35 The propylene glycol and catalyst were initially introduced together and heated to approximately 120C. The slurry of propylene glycol and starch was added as in Example 1. After the ~ ' ~o~
starch moisture (quantity of distillate: 1.7 kg liquid of water and propylene glycol) had been removed, the mixture of propylene glycol and fatty alcohol preheated to 90 to 1004C was introduced in a vacuum of 10~ mm Hg.
The removal of propylene glycol by distillation and the working up of the product mixture were carried out as in Example 1.
Neither the composition nor the quality of the reaction product differed significantly from the data of the product obtained in accordance with Example 1.
In further tests, complete transacetalization was carried out (0% by weight propylene glycol glucoside in the end reaction product).
Where MgO was used as the neutralizing agent, a product of high color quality (Klett value: 15, after the color stability test: 20) was also obtained with subsequent bleaching (see Table 1). :
' ~
.. . . . . . . .
~07~1 4 , - Table 1 Determination of the Klett values of C1214 glycoside (5% solutions in H2O: isopropanol = 70 : 25) .
Neutra- Bleaching % by weight Remarks Klett Color of lizing yes/no propylene value paste agent glycol glucoside Mg(OEt~2 + 5 ~ 10 Light yellow Mg(OEt) 2 + 5 pH 12** 15 Light yellow 1 hour, 100 C, Mg(OEt)2 - lS 83% PG* 31.7 Light yellow distil-led off MgO + - - 15 Light yellow MgO + _ pH 12**, 20 Light yellow 1 hour, NaOH/MgSO4 + - - 27 Light yellow . _ .
NaOH/MgSO4 + - pH 12**, 51.5 Dark yellow 1 hour, .. . .
NaOH + - - 50 Dark yellow ,45 * PG = propylene glycol ** Color stability test .
Claims (11)
1. A process for the production of alkyl glucosides from a saccharide component and at least one C8-C18 alkyl or alkenyl monofunctional primary fatty alcohol by the transacetalization method using propylene glycol, wherein a saccharide component (B), containing starch or partial starch degradation products, is added to a reaction medium (A), containing at least propylene glycol and an acidic catalyst and, which may contain, the fatty alcohol, which has been heated to 100 to 130°C, and the molar ratio of higher alcohol to propylene glycol being at most 1.
2. A process as claimed in claim 1, wherein the reaction medium (A) contains the propylene glycol in an amount of 3 to 8 mol per mol saccharide (expressed as anhydroglucose) and the fatty alcohol preheated to 90 to 100°C is added to the mixture of (A) and (B) in an amount of 3 to 8 mol per mol anhydroglucose under a pressure reduced to about 100 mm Hg, water and glycol being simultaneously removed by distillation.
3. A process as claimed in claim 1, wherein the reaction medium (A) contains a mixture of propylene glycol in an amount of 3 to 8 mol per mol saccharide component (expressed as anhydroglucose) and fatty alcohol in an amount of 3 to 8 mol per mol anhydroglucose and, after the addition of (B), water and propylene glycol are removed by distillation by reduction of the pressure in stages from 100 to 15 mm Hg at a temperature of from about 115 to about 120°C.
4. A process as claimed in any of claims 1 to 3, wherein in the saccharide component (B) comprises a mixture of starch or partial starch degradation products and propylene glycol, in an amount of 2 to 4 mol propylene glycol per mol anhydroglucose.
5. A process as claimed in any of claims 1 to 3, wherein the saccharide component (B) is added continuously.
6. A process as claimed in claim 1 or 2, wherein the monofunctional fatty alcohol in admixture with propylene glycol, in a ratio of 0.5 to 1.2 mol propylene glycol per mol fatty alcohol, is added to a mixture of (A) and (B).
7. A process as claimed in any of claims 1 to 3, wherein to obtain products of high color quality, the transacetalization reaction is prematurely terminated.
8. A process as claimed in any of claims 1 to 3, wherein after the transacetalization reaction, a) the acidic catalyst is neutralized with an organic or inorganic basic alkali or alkaline earth compound the pH is adjusted to a value of at least 8 and b) after filtration, the excess fatty alcohol, is distilled off to less than 5% by weight by a method which does not affect the reaction product.
9. A process as claimed in any of claims 1 to 3, wherein after the transacetalization reaction, a) the acidic catalyst is neutralized with an organic or inorganic basic alkali or alkaline earth compound the pH is adjusted to a value of from 9 to 10 and b) after filtration, the excess fatty alcohol, is distilled off to less than 5% by weight by a method which does not affect the reaction product.
10. A process as claimed in any of claims 1 to 3, wherein the catalyst is an acid from the group consisting of sulfuric, phosphoric and paratoluenesulfonic acid, present in an amount of from 0.01 to 0.03 mol per mol of the anhydroglucose unit present in the saccharide component.
11. A product obtainable by the process claimed in any of claims 1 to 3, comprising of 50 to 65% by weight alkyl monoglucoside, 8 to 15% by weight alkyl diglucoside, 2 to 5% by weight alkyl triglucoside, 5 to 20% by weight polyglucose and at most 3% by weight residual fatty alcohol and a free glucose content of less than 1% by weight.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE3900590A DE3900590A1 (en) | 1989-01-11 | 1989-01-11 | METHOD FOR PRODUCING ALKYL GLUCOSIDES |
| DEP3900590.0 | 1989-01-11 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2007514A1 true CA2007514A1 (en) | 1990-07-11 |
Family
ID=6371853
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002007514A Abandoned CA2007514A1 (en) | 1989-01-11 | 1990-01-10 | Process for the production of alkyl glucosides |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0377883A1 (en) |
| CN (1) | CN1044466A (en) |
| CA (1) | CA2007514A1 (en) |
| DE (1) | DE3900590A1 (en) |
| WO (1) | WO1990008154A1 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0492397A1 (en) * | 1990-12-26 | 1992-07-01 | Kao Corporation | Process for producing alkyl glycoside |
| ES2095348T3 (en) * | 1991-05-16 | 1997-02-16 | Kao Corp | AQUEOUS ALKYL GLYCOSIDE SOLUTION AGAINST MICROBIAL ACTIVITY. |
| DE4127231A1 (en) * | 1991-08-16 | 1993-02-18 | Henkel Kgaa | NEW ALKYLETHERGLYCOSIDES |
| DE4138250A1 (en) * | 1991-11-21 | 1993-05-27 | Henkel Kgaa | METHOD FOR PRODUCING ALKYLOLIGOGLUCOSIDES WITH REDUCED POLYGLUCOSE CONTENT |
| CN1045261C (en) * | 1992-04-12 | 1999-09-29 | 轻工业部日用化学工业科学研究所 | Prepn. method of alkyl glucoside surfactant |
| CN111423477A (en) * | 2020-05-28 | 2020-07-17 | 福建莲珂科技有限公司 | Polyol glucoside and preparation method and application thereof |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3772269A (en) * | 1969-07-24 | 1973-11-13 | Ici America Inc | Glycoside compositions and process for the preparation thereof |
| DE3001064A1 (en) * | 1980-01-12 | 1981-07-16 | Basf Ag, 6700 Ludwigshafen | METHOD FOR PURIFYING ALKYL GLYCOSIDES BY DISTILLATIVE DETERMINATION OF UNACTIVATED ALCOHOLS |
| EP0099183A1 (en) * | 1982-07-08 | 1984-01-25 | A.E. Staley Manufacturing Company | Method for preparing organo glycosides |
| DE3232791A1 (en) * | 1982-09-03 | 1984-03-08 | Basf Ag, 6700 Ludwigshafen | METHOD FOR PRODUCING ALKYL GLUCOSIDES |
-
1989
- 1989-01-11 DE DE3900590A patent/DE3900590A1/en not_active Withdrawn
- 1989-12-22 WO PCT/EP1989/001594 patent/WO1990008154A1/en unknown
- 1989-12-22 EP EP89123750A patent/EP0377883A1/en not_active Withdrawn
-
1990
- 1990-01-09 CN CN90100093A patent/CN1044466A/en active Pending
- 1990-01-10 CA CA002007514A patent/CA2007514A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| CN1044466A (en) | 1990-08-08 |
| WO1990008154A1 (en) | 1990-07-26 |
| EP0377883A1 (en) | 1990-07-18 |
| DE3900590A1 (en) | 1990-07-12 |
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