DE2220723A1 - PROCESS FOR THE PRODUCTION OF PURE POLYALKYLENE ETHERS WITH MODIFIED END GROUPS - Google Patents

Description

Badische Anilin- & Soda-Fabrik AG

Our reference: O.Z. 29 144 M / Wil

6700 Ludwigshafen, April 26th, 1972

Process for the production of pure polyalkylene ethers with modified End groups

The invention relates to a process for the production of pure polyalkylene ethers with modified end groups by polymerization of alkylene oxides in the presence of basic catalysts and subsequent modification of the polyalkylene ether with various End groups with simultaneous removal of the catalyst residues, the alkali-containing polyalkylene ethers with Compounds containing bound halomethyl, halomethylene or haloethyl groups are implemented.

The production of polyalkylene ethers by polymerizing alkylene oxides, which are attached to a starting component with reactive Adding hydrogen atoms in the presence of alkaline catalysts is known. Polyalkylene ethers are obtained with free hydroxyl groups, some of which have terminal alcoholate groups due to the alkaline reaction medium. Pure the further use of the polyalkylene ethers, it is necessary to convert the alcoholate residues of the polymers into free hydroxyl groups, in such a way that the polymers practically no longer contain any inorganic constituents.

In general, for this purpose, the alkali-containing polymers are neutralized with inorganic or organic acids, whereby Form emulsions from aqueous salt solutions and polyalkylene ethers. The water from the emulsions is then distilled off with a continuous increase in temperature. The remaining ones, in the polyether precipitating salts are separated off mechanically.

Inorganic acids such as sulfuric acid, phosphoric acid, hydrochloric acid, or acidic acids are used to neutralize the polymers Salts such as potassium hydrogen phosphate or organic acids such as citric acid, tartronic acid and others, must be exactly up to the equivalence point be neutralized to a minimum on the one hand

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basic residual alkali salts or, on the other hand, a minimum of excess acid. Furthermore, the alkali salt often falls in so fine crystals that the filtration, despite the use of filter aids, presents difficulties. In addition, discoloration of the polyalkylene ethers occurs especially when using sulfuric acid.

The difficulty of having to set the equivalence point exactly during the neutralization can, according to the US patent 5 0l6 4o4 can be removed by the use of a volatile acid such as hydrogen chloride. Here the hydrogen chloride Excess distilled off as a gas. The process has the disadvantage that the hydrogen chloride is highly corrosive to the Vessel material acts and the excess gas to avoid air pollution with the help of costly absorption and Washing towers must be separated or destroyed.

According to British patent specification No. 877 269, soils treated with acids are used to neutralize the polyalkylene ethers. A disadvantage of this method is the handling of solids, which can prepare, particularly with larger reaction mixtures difficulties, since up to about 4% by weight. Such earth, based on the Polyäthergewicht, necessary for neutralization of the polymers. In order to obtain a clear filtrate, a very dense filter material must be used to filter off such soils, which in turn results in long filtration times.

In order to purify the products, it has also been proposed to use polyalkylene ethers to dilute with a water-insoluble solvent and wash the resulting solution with water. By however, the subsequent solvent regeneration makes the process expensive in terms of equipment. Another difficulty creates the easy emulsification.

Apparatus and the use of auxiliaries are also expensive Process used to neutralize the reaction solution ion exchanger use. This is carried out in the presence of diluents, which are then separated off and regenerated

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Need to become. To avoid high product losses that ^s ion exchangers must be washed completely free of product before regeneration.

It is also proposed to remove the basic catalyst been to neutralize the reaction solution with carbon dioxide and then dehydrate it under reduced pressure. The process has the disadvantage that the basic catalyst is often incompletely neutralized, the resulting Alkali carbonate is very difficult to filter because of its fine particle size and is therefore an insufficiently purified polyalkylene ether polyol results.

For the reasons mentioned, it has so far not been possible in many cases - without lengthy post-treatment of the products - Polyalkylene ethers can be produced industrially by customary processes which are alkali-free, colorless and odorless at the same time.

The invention allows these disadvantages to be avoided and in one technically simple process by condensation of the alkaline Polyalkylene ethers with compounds containing activated halogen atoms bound, almost completely alkali-free, colorless and odorless polyalkylene ethers with modified end groups to manufacture.

The invention relates to a process for the production of pure polyalkylene ethers with modified end groups by polymerization of optionally substituted alkylene oxides with 2 to 4 carbon atoms in the alkylene chain in the presence of basic Catalysts and subsequent modification of the polyalkylene ether end groups with simultaneous removal of the basic catalyst residues. The new procedure is through characterized in that the alkali-containing polyalkylene ethers with compounds containing halomethyl, halomethyl or haloethyl groups contain bound with activated halogen atoms, reacts and separates the alkali salts formed.

With the aid of the process according to the invention it is possible to prepare polyalkylene ether polyols with modified end groups and a remainder

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to produce an alkali content of <5 ppm.

The new process offers the advantage that the precipitating agent does not cause any side reactions such as esterification or dehydration be effected, and that the polyalkylene ethers are modified with special end groups and in a process stage at the same time the basic catalyst residues can be separated in the form of easily filterable alkali halides,

The polyalkylene ethers are prepared by the customary, known working techniques; alkylene oxides with two to four carbon atoms are attached to themselves or generally to starter molecules with reactive hydrogen atoms in the presence of basic catalysts.

Suitable alkylene oxides are, for example, 1,3-propylene oxide, 1,2-butylene oxide, 1, ^ - butylene oxide, styrene oxide and preferably Ethylene oxide and 1,2-propylene oxide. The various alkylene oxides can be used individually, alternately one after the other or as a mixture,

Examples of starting molecules with reactive hydrogen atoms are: water, alcohols, glycols, triols, Phenols, amino alcohols, aliphatic or aromatic amines, diamines, triamines and hydrazines.

Common catalysts are alkali alkoxides with 1 to 4 carbon atoms in the alkyl radical, such as sodium and potassium methylate, Sodium and potassium ethylate, potassium isopropylate and sodium butylate and preferably alkali hydroxides such as sodium hydroxide and preferably potassium hydroxide. The catalyst is usually in an amount from 0.002 to 1.0, preferably from 0.01 to 0.5% by weight, based on the total weight of the starting components, used,

It is an essential feature of the new manufacturing process that the alkali-containing polyalkylene ethers with compounds that Contain halomethyl, halomethylene or haloethyl groups bound with activated halogen atoms, reacted and there-

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modified with special end groups and cleaned at the same time and then the alkali salts formed are separated off. Such compounds can be used individually or as mixtures.

Suitable compounds that contain bound halomethyl groups, are for example monochloromethyl glycol ether, chloromethyl ethyl ether, monochloroacetic acid ethyl ester, allyl chloride, Benzyl chloride and derivatives of the compounds mentioned. As the compound containing a halomethylene group, for example called the cyclic butadiene sulfone chlorohydrin. As containing halogenated ethyl groups Compounds come into consideration, for example; 3-chloro-l, 2-propanediol, 2-chloro-l, 5-propanediol, 2-chloroethyl-2'-hydroxy-ethyl-sulfone, Ethyl bromide, ethyl iodide, 2-chloroethyl acetate, 2-chloroethyl acrylate, N-2-chloroethylethylsulfonamide and N-2-chloroethyl-N-methylanilln. Preferably, however as compounds containing halogenated ethyl groups, halohydrins, such as phenylethylene chlorohydrin, ethylene bromohydrin and ethylene chlorohydrin used.

The halomethyl, halomethylene or haloethyl groups mentioned Containing compounds can optionally also have other reactive functional groups, such as amino or Contains hydroxyl groups bound. In this way, depending on the type of connections that can be used, the functionality is possible to vary the polyalkylene ethers. If, for example, compounds are used which, in addition to halomethyl, halomethyl- or halogenoethyl groups contain no other reactive groups, the hydroxyl functionality of the polyalkylene ethers becomes reduced. In some cases, however, it is of interest to improve the hydroxyl functionality through the use of di- or compounds of the type mentioned containing polyhydroxyl groups increase or with the help of derivatives containing monohydroxyl groups.

Compounds that have more than one reactive halomethyl, halomethyl or contain bound haloethyl group, show the same excellent cleaning effect with the polyalkylene ethers. Since such bl- or polyfunctional compounds at the same time

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act as crosslinking agents, however, the molecular weights will the polyalkylene ethers by linear chain extension or optionally three-dimensional networks changed many times.

Containing the amount of halomethyl, halomethylene or haloethyl groups required to bind the basic salts Compounds depends on the content of the reaction solution basic catalyst. Expediently, 1 to 3, preferably 1 to 3, are used per equivalent of the basic catalysts 1.2 equivalents of the halo-methyl, halomethylene or haloethyl-halo compounds mentioned, however, it is it is also possible to use the compounds mentioned in a large excess, for example 30 to 50 times the equivalent amount to use. In this case it is advantageous to select compounds which, if appropriate, are easily made by distillation the reaction mixture can be separated off, such as ethylene chlorohydrin or 3-chloro-1,2-propanediol.

More specifically, the polyalkylene ether are prepared so that in a mixture of the starter molecule and basic catalyst at temperatures of 90 to 150 ⁰ C, preferably 100 to 130 ⁰ C, optionally using a solvent inert under the reaction conditions, for example nitrogen, diluted alkylene oxide in the extent to which it reacts, for example in 2 to 6 hours, preferably 5 to 10 hours, at atmospheric pressure or optionally under increased pressure at 0.1 to 20, preferably 1 to 6 atmospheres.

After completion of the polymerization, the excess ethylene oxide at temperatures of 100 to 15O ⁰ C under reduced pressure, is distilled off and contain bound with activated halogen atoms of the polyalkylene having the described compounds halomethyl, halogen, methyl or Halogenäthylgruppen, at temperatures of 20 to 15O ⁰ C, preferably from 40 to 120 ⁰ C, treated.

The reaction mixture is - if the viscosities of the polyalkylene ethers are too high with inert solvents, like hydrocarbons or chlorinated hydrocarbons, diluted -

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Stirred for 0.5 to 20 hours, preferably 1 to 5 hours, after which the reaction vessel is optionally depressurized and any water still present and optionally volatile by-products or the excess halomethyl, halomethylene or haloethyl compounds, optionally under reduced pressure, at temperatures between 50 and 100 ⁰ C distilled off "Subsequently, the alkali metal halides in the usual manner, for example by decanting off the polyalkylene ether, washing with water, or preferably by filtration ,, optionally in the presence of 0.1 to 1 wt.% filter aid, based on the total weight of the reaction mixture, separated. '

The pure polyalkylene ethers produced according to the invention possess Molecular weights from 500 to 6000 and, depending on the type of product, viscosities from 300 to 25,000 centipoise at 25 ° C, Hydroxyl group functionalities from 2 to -14 and optionally above, in particular between 2 and 6> and alkali levels below 20 ppm, preferably below 5 ppm.

The polyalkylene ethers are used as textile auxiliaries, surface-active Substances and hydraulic fluids used. The products are also suitable for the production of polyurethanes, for example paints, films, elastomers and hard, semi-hard and soft foams.

The manufacturing method of the present invention is carried out by the following Examples explained in more detail. The parts mentioned in the examples are parts by weight. Parts by volume are related to parts by weight as liters are related to kilograms.

example 1

A mixture of 500 parts of a block polyether polyol with a hydroxyl number of 4l, which was prepared from trimethylolpropane as a starter, propylene oxide and ethylene oxide in a molar ratio of 1 % 71 s 15 in the presence of sodium methylate as a catalyst and contains 1,400 ppm of sodium ions as an impurity, and 6.19 parts of j5-chloro-1,2-propanediol is stirred at 80 C for two to three hours in a nitrogen atmosphere and then

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treated with 25 parts of a silica gel based filter aid. After filtering off the impurities at 80 ° C., a colorless, clear polyether polyol with a hydroxyl number of 43, a sodium ion content of 1 ppm and a chloride content below 0.5% by weight is obtained .

Examples 2 to 5

500 parts of a block polyether polyol with a hydroxyl number of 37, which consists of trimethylolpropane as a starter, propylene oxide and ethylene oxide in a molar ratio of 1 s 72; 15 in the presence of potassium methylate was prepared as a catalyst and contains 1,400 ppm of potassium ions as an impurity, is analogous to the information in Example 1 treated with halogen-active substances. The halogen-active substances used and the analysis values of the obtained Pure polyether polyols are summarized in Table 1.

Table 1

at
game Ha1οgenakt ive
Substances Parts per
500 parts Analysis values of the pure
Polyether polyol Hydroxyl
number Polyether
polyol Potassium halogen
ions ions
(ppm) {%) 42 2 Glycerol chlorine
hydrin 5.67 3 0.18 36 3 Ethylene chlorohydrin 4.34 6 0.059 35 4th Benzyl chloride 6.3 7 0.2 36 5 Ethylene bromohydrin. 3.6 8 ο, η Example 6

A mixture of 500 parts of a block polyether polyol with a hydroxyl number of 17, which was prepared from glycerine as a starter, propylene oxide and ethylene oxide in a molar ratio of 0.5 % 72:15 in the presence of potassium methylate as a catalyst and contains ΐβΟΟ ppm potassium ions as an impurity, and 6.9 parts Ä'thylenchlorhydrin is at 80 ° C for two to three hours in a stick

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Stirred substance atmosphere and then with 25 parts of one Treated filter aid based on silica gel. After filtering off the salts at 80 ° C., a colorless, clear one is obtained polyether polyol with a hydroxyl number of 19 and a content of potassium ions less than 1 ppm and chloride ions of 0.1J weight;

Example ¹ J

A mixture of 500 parts of a polyether polyol having a hydroxyl number of 42 which was prepared from glycerin as an initiator and a mixture of propylene oxide and ethylene oxide weight ratio i _m 0.24 s 14.2 s 2.5 as a catalyst in the presence of potassium hydroxide and l600 ppm Contains potassium ions as an impurity, and 10 parts of 3-chloro-1,2-propanediol is treated analogously to the information in Example 6. After filtering off the impurities, a colorless polyether polyol with a potassium ion content of 4 ppm and a hydroxyl number of 58 is obtained.

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Claims (2)

- 10 - 0.Ζ.29 l44 Claims ^L. Process for the preparation of pure polyalkylene ethers with modified end groups by polymerizing optionally substituted alkylene oxides with 2 to 4 carbon atoms in the alkylene chain in the presence of basic catalysts and subsequent modification of the polyalkylene ether end groups with simultaneous removal of the basic catalyst residues, characterized in that the alkali-containing polyalkylene ethers with compounds containing halomethyl, halomethylene or haloethyl groups bound with activated halogen atoms, converts and separates the alkali metal salts formed. 2. Process for the preparation of pure polyalkylene ethers with modified end groups according to claim 1, characterized in that the alkali-containing polyalkylene ethers are reacted with halohydrins and the alkali salts formed are separated off. Badische Anilin- & Soda-Fabrik AG. 309845/1033