DE102008004044A1 - Preparation of terminal sulfated alpha-alkenyl polyether comprises reacting sulfur trioxide with hydroxyl-group terminated alpha-alkenyl-omega-polyether in a microstructure reactor - Google Patents

Abstract

Preparation of terminal sulfated alpha -alkenyl polyether, comprises reacting sulfur trioxide with hydroxyl-group terminated alpha -alkenyl-omega -polyether in at least one microstructure reactor. An independent claim is included for a method for sulfating hydroxyl-group terminated alpha -alkenyl-omega -polyether of formula ([CH 2=CR 1>-L-(C 2H 4O) n(C 3H 6O) p(C xH 2 xO) q(C 2H 4 - dR 2> dO) r]H) (I) in undiluted form or dissolved form, continuously with sulfur trioxide in a microstructure reactor, selectively at the hydroxyl group by receiving the alpha -terminated carbon-carbon double bond. R 1>H or CH 3; L : bivalent optionally branched 1-18C, preferably 1C, hydrocarbon residue; n, p, q, r : 0-100, where the sum of n, p, q and r is >= 1; d : 1-3; x : 4-20; and R 2>1-20C hydrocarbon residue or aromatic (both optionally substituted).

Description

The The invention relates to a process for the preparation of terminal sulfated α-alkenyl polyethers by reaction of gaseous Sulfur trioxide with OH-terminated α-alkenyl polyethers in microstructured reactors.

The sulfation of saturated fatty alcohol ethoxylates with gaseous sulfur trioxide to alkyl ether sulfates is known in the art and is z. B. in detail in "Surfactants in Consumer Product, Publisher: J. Falke, 1987, Springer Verlag, Berlin - Heidelberg, page 67 ff" described. Also known and prior art is the reaction of gaseous sulfur trioxide with α-olefins to so-called α-olefinsulfonates, which have great technical importance as surfactants. In detail, this process and the underlying chemistry in "Surfactants in Consumer Product, Publisher: J. Falke, 1987, Springer Verlag, Berlin - Heidelberg, page 71 ff" described. Ebendort is described that in the implementation of α-olefins z. B. R-CH ₂ -CH ₂ -CH ₂ -CH = CH ₂ with sulfur trioxide to form the following reaction products: 1.) R-CH ₂ -CH ₂ -CH ₂ -CH = CH-SO ₃ H, 2. ) R-CH ₂ -CH ₂ -CH = CH-CH ₂ -SO ₃ H, 3) R-CH ₂ -CH = CH-CH ₂ -CH ₂ -SO ₃ H, 4.) R-CH = CH -CH ₂ -CH ₂ -CH ₂ -SO ₃ H. In parallel, the formation of a 1,3-sultone takes place, which reacts by hydrolysis with water or alkalis to the following products: 5.) R-CH ₂ -CH ₂ - CH (OH) -CH ₂ -CH ₂ -SO ₃ H, 6.) R-CH ₂ -CH = CH-CH ₂ -CH ₂ -SO ₃ H and 7.) R-CH ₂ -CH ₂ -CH = CH-CH ₂ -SO ₃ H. Depending on the reaction route, the double bond is retained, but is substituted by an SO ₃ H group or no longer terminal.

The DE 1 917 300 teaches that in the reaction of unsaturated alcohols with sulfur trioxide a combination of the reactions as they are known from the reaction of α-olefins or fatty alcohols with sulfur trioxide occur, ie both the double bond and the OH group are sulfonated by the sulfur trioxide or sulfated.

However, a simple and technically feasible process is desired in which α-unsaturated alcohols, in particular α-alkenyl polyethers, are sulfated selectively at the OH group, the terminal CH ₂ CHCH double bond remaining intact and unchanged. Such terminal double bonds can be z. B. hydrosilylate with hydrogen siloxanes under the conditions known to those skilled. The silicone polyether sulfates obtainable thereby find, inter alia, use as wetting and emulsifying agents, such as. B. in the DE-17 45 514 ( US 3,513,183 ), or for the production of aqueous foams for cosmetic purposes, such as. B in US 4,960,845 and US-B-6,777,521 disclosed.

In the hitherto known processes for the sulfation of unsaturated alcohols or unsaturated alcohol ethoxylates, the procedure is as follows:
The DE 1 917 300 discloses a process for reacting unsaturated alcohols having about 10 to 20 carbon atoms, such that the molar ratio of sulfur trioxide to alcohol is about 1.15 to 1. However, about 12% of the double bonds continue to be sulfated.

The JP 58035165 discloses a process for the preparation of sulfate esters of benzyl alcohol and allyl alcohol using the sulfur trioxide / dioxane complex to sulfate the hydroxy group in 1,2-dichloroethane as a solvent at a temperature of -10 ° C. A disadvantage of this process is the use of a sulfur trioxide-dioxane complex and a halogen-containing solvent, as well as the industrially difficult cryogenic reaction.

Nowak et al. report in Przemysl Chemiczny (1971), 50 (4), pages 222 to 225 , on the reaction of unsaturated C ₁₆ -C ₂₂ fatty alcohols with gaseous sulfur trioxide using z. As ether derivatives of fatty alcohols or phenols as additives, wherein the reaction of the unsaturated fatty alcohols 92-97% with a selectivity of Alkenylsulfatbildung of 70-85%. A disadvantage of this method is the use of additives, which must then be separated again to obtain pure products.

The JP 096-157243 discloses a process for sulfating unsaturated higher alcohols with gaseous SO ₃ in a falling film reactor with the addition of 5-40 wt%, based on the unsaturated alcohol, of saturated polyethylene glycol diesters for selective sulfation of the OH group. A disadvantage is the high addition of an additive to achieve a selective sulfation of the OH group. Furthermore, the document generally refers to the sulfation of an OH group in the presence of a double bond and not in particular to α-position unsaturated alcohols.

The DE 1 802 696 discloses a process for the selective sulfonation of unsaturated fatty alcohols and their ethoxylation products using gaseous SO ₃ and amido compounds which serve to inhibit the reaction between SO ₃ and the carbon-carbon double bond. As amido compounds z. For example, urea, diethylformamide, urea derivatives or acid amides. Likewise, the FR 2 198 911 a method for the selective sulfation of unsaturated alcohols in the presence of urea. A disadvantage of the process described here is again the use of an additive for selective sulfation of the OH group to obtain the double bond.

Around in the prior art selective sulfation of the OH group with sulfur trioxide in unsaturated alcohols or their Alkoxylates with unchanged preservation of carbon-carbon To obtain double bond must have additives of the reaction be added, the selectivity for sulfation increase at the OH group.

Of the The present invention is therefore based on the object, a method for the selective sulfation of the terminal OH group of unsaturated Alcohols or their alkoxylates, preferably of α-alkenyl polyethers with terminal OH group and more preferably of Allyl polyethers with terminal OH group, with preservation to find the α-alkenyl group, under overcoming the disadvantages of the prior art. It was still a task the invention to develop a method that simply is to be transferred to the technical scale.

Surprisingly, it has been found that the object can be achieved by reacting an α-alkenylpolyether having a terminal OH group and particularly preferably an allylpolyether having a terminal OH group with gaseous SO ₃ in a microstructure reactor. In particular, the method according to the invention has the advantage over the prior art that no additional additives are necessary for the selective reaction.

The Inventive method will be exemplified below without the invention being limited to these exemplary embodiments should be. Below are areas, general formulas, or compound classes given, these should not only the corresponding areas or groups of compounds explicitly mentioned but also all subsections and subgroups of compounds, by removing individual values (ranges) or connections can be obtained. Be under the present Description Documents cited, their contents should be completely to Disclosure of the present invention.

It Thus, a process for the preparation of terminal sulfated α-alkenyl polyethers by reaction of sulfur trioxide with OH groups terminated α-alkenyl-ω-hydroxy-polyethers in at least one microstructure reactor available posed.

The Process can be carried out at temperatures from 10 ° C to 100 ° C be performed.

Furthermore, the process can be carried out without molar deficiency of SO ₃ .

Further Embodiments of the invention Process emerge from the claims, their content is completely part of this description.

Microstructured reactors are characterized by chemical micro process control, preferably a continuous flow of substrate through structures used with characteristic dimensions in the sub-millimeter range becomes.

The microstructured reactors preferably used here are characterized by horizontal or vertical fillaments which are traversed by the reactants in the countercurrent principle and thus lead to intensive contact between the components in the narrowest space and at the same time extremely effective temperature control. A particularly preferred type of microstructured reactor in the context of this application is a microfine-film reactor which, in 1 is shown schematically.

In a preferred embodiment of the invention, the process for the sulfation of OH-terminated α-alkenyl polyethers is that α-alkenyl-ω-hydroxy-polyether of the general formula (I) [CH ₂ = CR ¹ -L- (C ₂ H ₄ O) _n (C ₃ H ₆ O) _p (C _x H ₂ O) _q (C ₂ H _4-d R ² _d O) _r ] H (I ) In which
R ^{1 is} H or methyl,
L is a divalent optionally branched hydrocarbon radical having 1 to 18 C atoms, preferably 1 to 4 C atoms and particularly preferably a C atom, the indices
n, p, q and r are independent integers from 0 to 100, the sum of
n, p, q and r ≥ 1, and if more than one of the indices n, p, q, r> 0, the general formula (I) may be a random oligomer or a block oligomer;
wherein the sum of n, p, q and r is preferably 2 to 250, preferably 5 to 150 and particularly preferably 10 to 80 and in which such alkenyl-ω-hydroxy-polyethers (I) are preferred in which n and / or each p is ≥ 3, preferably 3 to 100, and preferably 5 to 50; Particular preference is given to those alkenyl polyethers (I) in which n and p are each 3, preferably 3 to 100 and preferably 5 to 80 and
q and / or r 0, preferably q and r = 0,
d is an integer 1 to 3,
x is an integer of 4 to 20, preferably 4 to 12, particularly preferably 4 to 8,
R ^{2 is} a monovalent branched or unbranched substituted or unsubstituted hydrocarbon radical having 1 to 20 C atoms, which is also an aromatic or optionally also a substituted aromatic radical,
in undiluted liquid or dissolved form are metered continuously into a microfine film reactor and the α-alkenyl-ω-hydroxy-polyether sulfated under metered supply of sulfur trioxide in the microreaction channels in contact with a heat exchange surface selectively at the terminal OH group and the reaction product continuously from the microfill film reactor is discharged.

Prefers is α-alkenyl-ω-hydroxy-polyether an α-allyl-ω-hydroxy-polyether used.

at the process of the invention is the α-alkenyl-ω-hydroxy-polyether over passed a plurality of parallel microreaction channels.

The Microreaction channels are preferably on a reaction plate arranged and in contact with a heat exchange surface.

Prefers the sulfur trioxide is continuously metered in gaseous form.

In this case, the sulfur trioxide can be passed in cocurrent, countercurrent or crossflow to the α-alkenyl-ω-hydroxy-polyether. Preferably, the SO _{3 is passed} in countercurrent to the alkenyl-ω-hydroxy-polyether.

The sulfur trioxide stream may be diluted with other inert gases that do not participate in the reaction. Inert gas may be helium, neon, argon, krypton, xenon, nitrogen or carbon dioxide or mixtures thereof. Nitrogen is particularly preferred as the inert gas. The sulfur trioxide can thus be supplied to the microstructure reactor as pure gas or in mixture with an inert gas. In this case, the content of sulfur trioxide in admixture with an inert gas can be from 1 to 100% by volume, preferably 1-50% by volume, more preferably 1-10% by volume, of SO ₃ .

The Molar ratio of sulfur trioxide to OH-terminated α-alkenyl-ω-hydroxy-polyether can are in the range of 1.0 to 1.25: 1, preferably in the range from 1.0 to 1.1: 1.

With a deficiency of SO ₃ incompletely sulfated product mixtures are obtained.

In the examples impressively clear the advantage of the invention Procedure can be shown in which also a surplus reagent does not cause a further reaction under attack on the olefinic Double bond leads.

The Sulfation of the α-alkenyl-ω-hydroxy-polyether with gaseous sulfur trioxide can in a temperature range from 10 ° C to 100 ° C, preferably 20 ° C to 75 ° C and more preferably from 30 ° C to 60 ° C, be performed.

The α-alkenyl polyether may be in a solvent which does not interfere with the sulfation reaction participates, be solved. Examples are Alkanes, cycloalkanes or OH-free polyethers. Especially preferred However, the reaction is in the absence of a solvent carried out.

at higher viscosity α-alkenyl polyethers may be diluted with an inert solvent for reducing the viscosity purely technically advantageous to lower the pump pressure to be able to.

After the reaction, the reaction product may be subjected to further purification. The acid α-alkenyl polyether sulfates obtained in the reaction can be stirred into aqueous bases, neutralized and adjusted to a desired pH, eg. B. between 5 and 8, can be set. The neutralization can be carried out with bases selected from the group consisting of alkali metal hydroxides such as sodium, potassium and lithium hydroxide, alkaline earth metal oxides and hydroxides such as magnesium oxide, magnesium hydroxide, calcium oxide and calcium hydroxide, alkali metal carbonates, alkali metal hydrogencarbonates and ammonia, mono-, di- and tri-C _{2 4} alkanolamines, for example mono-, di- and triethanolamine, as well as primary, secondary or tertiary C _1-4 alkylamines. Neutralization is preferably carried out with alkali metal hydroxides or alkali metal carbonates or alkali metal hydrogencarbonates. Neutralization is particularly preferred with an aqueous solution of the alkali metal hydroxides or alkali metal carbonates or alkali metal hydrogencarbonates. Particularly preferred are sodium hydroxide and sodium carbonate or sodium bicarbonate for neutralization. The neutralization bases can be used as solid or as aqueous solutions with a content of 5 to 55% by weight of neutralization base.

The Alkenylpolyethersulfates may continue after neutralization, in a manner known per se to those skilled in the art, by addition bleached from hydrogen peroxide or sodium hypochlorite solution to achieve a color lightening.

A particularly advantageous embodiment of the invention in that several microfine film reactors are connected in parallel.

at The process of the invention is the α-alkenyl-ω-hydroxy-polyether preferably metered continuously into the microstructure reactor and the reaction product after the reaction is preferably continuous pumped out of the reactor.

The Sulfur trioxide may, for. B. by stripping an oleum solution with an inert gas, preferably nitrogen. Of the Inert gas flow can be adjusted with an external flow controller and thus provides for the adjustment of the sulfur trioxide concentration in the gas mixture. Alternatively, the sulfur trioxide can also be used directly or metered without inert gas. The setting of the temperature in Microstructure reactor is preferably carried out by means of a thermostat. By installing thermocouples in the educt and product side of the microstructure reactor can be input and output temperature be measured.

The Product of the reaction can be further worked up as needed, eg. B. be neutralized.

1 shows, by way of example, an arrangement of a microstructure reactor of the type of a falling film reactor to be used according to the invention. The components of this type of reactor are ( 1 ) a housing bottom with integrated cooling passage, ( 2 ) a lid with integrated reaction space, ( 3 ) a microstructured reaction sheet, ( 4 ) a reaction zone mask, ( 5 ) the educt feed (liquid), ( 6 ) the product removal, ( 7 ) the liquid flow in microchannels, ( 8th ) Reaction gas guide, ( 9 ) the gas inlet, ( 10 ) the gas outlet, ( 11 ) Cooling medium guide, ( 12 ) the Kühlmediumauslass and ( 13 ) the cooling medium inlet.

Advantageous two pumps are used, on the one hand a pump of the feed the educt in the microstructure reactor and on the other hand the second pump discharges the product from the system.

Embodiment:

In the example below is the present Invention described by way of example, without the invention, whose Range of application is the entire description and the claims results in the embodiments mentioned in the examples should be limited.

Example:

The α-allyl-ω-hydroxy-polyether (structure: CH ₂ = CH-CH ₂ - (C ₂ H ₄ O) ₁₁ -CH ₂ -CH ₂ -OH) is reacted at 90 ml / h (0.15 mol / h). h) with a educt pump in the microfine film reactor (see schematic representation of 1 ). In countercurrent process 30 Nl / h of nitrogen, which are passed through a template with oleum, fed into the reactor. By weight loss it was previously determined that this corresponds to an input of 0.15 mol / h SO ₃ , so that the molar ratio α-alkenyl-polyether: SO _{3 is} equal to 1. The reactor is thermostated with a thermostat at 50 ° C. The resulting product is removed from the reactor with a product pump. After 90 minutes run time, a sample is taken and analyzed by NMR spectroscopy.

By doubling the metering rate of the α-alkenyl-ω-hydroxy-polyether and increasing the nitrogen flow to 50 Nl / h, which corresponds to an amount of SO ₃ of 0.25 mol / h, the molar ratio of the components becomes greater than 1 to 1 set. The new molar ratio α-alkenyl-ω-hydroxy-polyether: SO ₃ then results in 1,2. After a further 90 minutes running time another sample is taken and analyzed by NMR spectroscopy.

The ¹ H-NMR spectroscopy (measured with a Bruker AVANCE 400 NMR spectrometer with the evaluation software XWIN-NMR 3.1 and tetramethylsilane as internal standard) each gave a degree of purity of the produced α-allyl polyether ω-sulfate of> 99%, wherein the Allyldoppelbindung remained completely and unsubstiuted. There was also no shift of the double bond or substitution on the double bond. Only the terminal OH group was sulfated and converted into a -OSO ₃ H group.

This result was independent of the SO ₃ dosage to achieve, as long as only the α-allyl ω-hydroxy polyether to SO ₃ ratio greater than 1: 1.

In order to shows in an impressive way the advantage of the invention Procedure in which even an excess of reagent is not to a further reaction under attack on the olefinic double bond leads.

1

caseback with integrated cooling passage

2

cover with integrated reaction space

3

microstructured reaction plate

4

Reaction zone mask

5

reactant (liquid)

6

product

7

liquid stream in microchannels

8th

reaction gas

9

Gas inlet

10

Gas outlet

11

cooling medium

12

coolant outlet

13

Coolant inlet

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 1917300 [0003, 0005]
• - DE 1745514 [0004]
• - US 3513183 [0004]
• - US 4960845 [0004]
• - US 6777521 B [0004]
• - JP 58035165 [0006]
• - JP 096-157243 [0008]
• - DE 1802696 [0009]
• FR 2198911 [0009]

Cited non-patent literature

• - "Surfactants in Consumer Product, publisher: J. Falke, 1987, Springer Verlag, Berlin - Heidelberg, page 67 ff" [0002]
• - "Surfactants in Consumer Product, publisher: J. Falke, 1987, Springer Verlag, Berlin - Heidelberg, page 71 et seq." [0002]
• - Nowak et al. report in Przemysl Chemiczny (1971), 50 (4), pages 222 to 225 [0007]

Claims (17)

Process for the preparation of terminal sulfated α-alkenyl polyethers by reaction of sulfur trioxide with OH groups terminated α-alkenyl-ω-hydroxy-polyethers in at least one microstructure reactor. Method according to claim 1, characterized in that that the reaction is carried out at 10 ° C to 100 ° C becomes. Method according to one of claims 1 or 2, characterized in that the reaction is carried out without molar deficiency of SO ₃ . Process for the sulfation of OH-terminated α-alkenyl-ω-hydroxy-polyethers of the general formula (I) CH ₂ = CR ¹ -L- (C ₂ H ₄ O) _n (C ₃ H ₆ O) _p (C _x H ₂ O) _q (C ₂ H _4-d R ² _d O) _r ] H (I) Wherein R ^{1 is} H or methyl, L is a divalent optionally branched hydrocarbon radical having 1 to 18 C atoms, preferably 1 to 4 C atoms and particularly preferably a C atom, the indices n, p, q and r are independent from one another Numbers are from 0 to 100 and the sum of n, p, q and r ≥ 1 is d is an integer 1 to 3 x is an integer 4 to 20, R ^{2 is} a monovalent branched or unbranched substituted or unsubstituted hydrocarbon radical having 1 to 20 C atoms, which is also an aromatic or optionally a substituted aromatic radical, in neat liquid or dissolved form, continuously with sulfur trioxide in a microstructure reactor, selectively at the OH group to give the alpha carbon-carbon double bond. Process according to claims 1 to 4, characterized in that the microstructured reactor is a microfine film reactor is that of a variety of parallel microreaction channels on a reaction plate and in contact with a heat exchange surface stands. Method according to one of claims 1 or 4, characterized in that the sulfur trioxide continuously is metered in gaseous form. Method according to one of claims 1 to 4, characterized in that the sulfur trioxide as pure gas or supplied to the microstructure reactor in admixture with an inert gas becomes. Method according to one of claims 1 to 4, characterized in that as α-alkenyl-ω-hydroxy-polyether an α-allyl-ω-hydroxy-polyether is used. Method according to one of claims 1 or 4, characterized in that the sulfation of the α-alkenyl-ω-hydroxy-polyether with gaseous sulfur trioxide in a temperature range from 20 ° C to 75 ° C is performed. Method according to claim 9, characterized that the sulfation of the α-alkenyl-ω-hydroxy-polyether with gaseous sulfur trioxide in a temperature range from 30 ° C to 60 ° C is performed. Method according to one of claims 1 to 10, characterized in that the molar ratio of sulfur trioxide to α-alkenyl-ω-hydroxy-polyether in the range of 1.0 to 1.25: 1. Method according to claim 11, characterized in that the molar ratio of sulfur trioxide to α-alkenyl-ω-hydroxy-polyether in the range of 1.0 to 1.1: 1. Method according to one of claims 1 to 12, characterized in that the α-alkenyl-ω-hydroxy-polyether in a solvent that does not participate in the sulfation reaction participates, is solved. Method according to claim 13, characterized in that that as solvents alkanes, cycloalkanes or OH-free polyethers or mixtures thereof can be used. Method according to one of claims 1 to 12, characterized in that the reaction in the absence of a solvent is carried out. Method according to one of claims 1 to 15, characterized in that a plurality of microstructured reactors, in particular Microfalm film reactors are connected in parallel. Method according to one of claims 1 to 16, characterized in that the sulfur trioxide in cocurrent, countercurrent or cross-flow of the α-alkenyl-ω-hydroxy-polyether is supplied.