CS241409B1 - Method of water/soluble polyerthers' and/or copolyethers' refining or at least limitation - Google Patents

Abstract

At least partially water-soluble polyethers and/or copolyethers based on ethylene oxide and/or propylene oxide are purified from a catalyst, comprising ions of alkali metals or undesired admixtures, by acids or acidically reacting substances, e.g. ion exchangers, inorganic or polyhydridic organic acids, preferably trihydrogen phosphoric acid, in an amount of 0.3 to 2.0 mol per one mole of the catalyst.

Description

(54)

A method of refining at least limited water-soluble polyethers and / or copolyethers

The refining of at least sparingly water-soluble polyethers and / or copolyethers based on ethylene oxide and / or propylene oxide from the catalyst, in particular alkali metal ions or undesirable impurities formed during production, is carried out with acids or acid-reacting substances, in particular organic or polyesters, inorganic preferably from 0.3 to 2.0 per mole of catalyst, optionally in the presence of a solvent, a sorbent, or a chemical decolorizer, followed by centrifugation of insoluble matter by filtration or centrifugation. Refined products can be used for the preparation of polyurethanes.

241 409

The invention relates to the treatment of at least water-insoluble polyethers and / or copolyethers based on ethylene oxide and / or propylene oxide so that they can be a suitable raw material for. ^b productions of ^hy drof NYC ^{hp l ly} ure of ^{which is} a new productions úalšie ^b ky.'Ide especially the removal of catalyst residues or polyadacie kopolyadacie, such as alkali metal and by-products of the reaction of the synthesis of polyethers.

For the production of polyurethanes it is required that the content of alkali^hkovov v^pabout^LyetEroc^h he was.^pabout^D 5 · 1θ ”^ wt. (5 p.p.m ·). While the refining of water-insoluble polyethers, e.g. polyether diols to polyether polyols, prepared e.g. polyadation of propylene oxide to diols to polyols is protected by many patents and copyright certificates.^iOof alkali metals. So remove^òovanie h^yalkali metal hydroxides from water-insoluble polyethers is based on their neutralization with aqueous solutions of saric acid or organic, mainly dicarboxylic acids⁽V. Brit. pat. 916 552 and 958 39⁰⁾. ba^lit is alike^toata the lysers adsorb on magnesium silicates at a temperature of 80 to -30 ° C per year^atOmnos^you me^Leho mno^fromwater.^pabout^TSilicates are then removed by filtration (U.S. Pat. No. 4,129,718). . They are also known. way. removing the alkali catalysts from the water-insoluble polyols by extracting the alkali catalysts with water, the extraction being rapidly dissolved. polyols in hexane (U.S. Pat. No. 3,715,402), or the alkaline catalysts are neutralized with acidic acid with alkylbenzenesulfonic acid or alkyltoluenesulfonic acid (NSR Pat, e.g. 2,737,473). from alkali with an aqueous solution of potassium bisulfite at a temperature of 20 to 130 ° C and a pH of 6.5 to 7.5 · The precipitated salts are removed by vacuum removal of water! (Polish Pat. 94 4θ8), A similar GDR pat · 71 622 heats the removal of the alkaline catalyst with an aqueous sodium hydrogen sulphate solution. The separation of alkali salts from crude emulsions formed by neutralizing an alkali catalyst in a water-insoluble polyether with sulfuric acid in the presence of 1 to 30% by weight of water and 0 to 30% by weight of an organic solvent is also known.

The disadvantage of these processes is mainly that they are only suitable for refining water-insoluble polyethers. In addition, in the case of use of water resp. of aqueous solutions, too much heat is required to distill off the water. These disadvantages are eliminated, respectively. solves the technical problems of refining water-soluble polyethers by the process of the present invention.

According to the invention, the process for the refining of at least sparingly water-soluble polyethers and / or icopolyethers based on ethylene oxide and / or propylene oxide from a catalyst, in particular alkali metal ions or undesirable admixtures produced during production, is carried out by refining with acids or acid-reacting substances of polybasic organic acids, preferably trihydroxyphosphoric acid, in an amount of 0.3 to 2.0, preferably 0.8 to 1.1 mol per mole of catalyst, optionally in the presence of a solvent, sorbent or chemical decolorizer, followed by removal of insoluble matter by filtration or centrifugation .

An advantage of the water refining process of at least partially soluble polyethers of the present invention is the high efficiency of the removal of alkali metal cations or alkali metals from the ether poles or copolyethers. The polyether or copolyether thus treated contains, under 3 · 1θ% or 1 · 10% by weight, alkali metal cations and is suitable for preparing polyurethanes.

241 409

Another advantage is the possibility of simultaneously removing other, especially colored admixtures from polyethers and last but not least - low energy consumption of refining.

Implementation of the refining process. according to the invention, it does not require expensive equipment and can be carried out continuously, discontinuously or semi-continuously.

In a particular embodiment of the method of the present invention, a number of variants may be used which may be appropriate to the individual under the circumstances. manufacturers or users of polyethers but. bo copolyethers. As used herein, a polyether or a polyether diol and a polyether polyol of the present invention, - means homopolyadície products of ethylene oxide and propylene oxide, i.e. polyethylene glycol, and also the ^p ro ^{LYP Pyle} co ^glycol n ^L, poured PROD. ^c t ^{y - y} and ^says the objective of ethylene oxide and propylene oxide to diol to polyol, or mixtures thereof. The term copolyether means, on the one hand, the products of copolyaddition. ethylene oxide with propylene oxide, but most often block polyadditions, e.g. to polyethylene glycol the polyaddition of propylene oxide continues, or to polypropylene glycol the polyaddition of ethylene oxide continues. The copolyaddition may also begin on other diols or even polyols, e.g. to glycerol, trimethylolpropane, pentaerythritol, triethanolamine and the like. Said production of polyethers or copolyethers is carried out under the catalytic action of bases, in particular alkali metal hydroxides or Lewis acids. However, catalysts or catalyst residues need to be removed from the polyethers or copolyethers produced for a number of technically demanding applications. In this case, it is appropriate to ensure that polyethers pain TekUT ^{E P} R ^A CH temperature to 150 ° C. In ^EXAMPLE ap ^d e ^to the ^melt of the ^Requirement is difficult to ensure a possible procedure is to dilute the polyether -s - a suitable solvent, "eg. nižším.alkoholom. It is possible not just ^{f b} b ⁱ EZ water alco znLeiovadJo of 'the P ^ fall, ^the en. the ions are removed by cation exchangers or by anion exchangers.

The use of alcohols such as methanol or isopropyl alcohol and the like. it is preferred that these alcohols do not dissolve the sodium and potassium salts. The alkali metal salts can then be removed by conventional separation procedures, such as e.g. - filtration and centrifugation. In addition, to remove alcohols from. 5,241,409 distillation flows require considerably less heat than water removal. In addition to the solvents mentioned it can also be ^{employed, and} e ^ner · kt ^ ^and out of the solvent S, at ^p and ^d not zrieáovačELá, the ^p r. ^ketones, acetone »methyl ethyl, ^ metylíormamid., ^p r ^IR ora Where they are used for the preparation of polyurethanes, solvent ^and dl ^ovou te ^c ervices," Papadis is a ^C o-treb ^yl icii and> N of ^P olyéteru removed . An example is the production of microporous polyurethane materials.

The use of inorganic acids exploits the fact that potassium salts. and hydrogen, e.g. phosphates, sulphates, carbonates, chlorides are insoluble in polyethers or polyether diols, and the resulting precipitate can be removed by filtration, possibly by another separation method. These reasons it is desirable to use anhydrous, and particularly polybasic acids, particularly orthophosphoric acid, which also is suitable in terms of the low co ^Rc will eat in the konštrulráným materisúom ^No. m ^p ou ^ ny kyse ^living matter or tAhydrogénfosforečnej of overdose, since not only normal but also acid salts of sodium and potassium · are polyether or polyether-insoluble. Similarly, sulfuric acid salts do not dissolve in alcohols and acetone.

In a particular embodiment of the process according to the invention, the stoichiometric amount of trihydrogenphosphoric acid, optionally with a 10% excess, is added, depending on the amount of catalyst (potassium or sodium hydroxide) used or present in the crude polyether or copolyether. The solution was stirred for about 20 minutes, ^wherein the warm • a temperature between approximately ³⁰ and 12 ^{W 0} and the ^P R is held typically for 20 to 30 minutes, and then filtered the precipitate. Alternatively, the alkali content of the polyether diol or polyether solution can be determined by acidimetric titration and the amount of acid required for precipitation is used.

If the polyether diol is dark, activated carbon may be added to the solution before precipitation of the alkali, optionally a chemical decolorizing agent, e.g. sodium sulfite, phosphoric acid, sodium hypochlorite. The activated carbon is then filtered off along with the precipitated salt, most preferably potassium phosphate and / or sodium phosphate.

241 409

Deionization can also be carried out on ion exchangers - ion exchangers rt- ^lH , anion exchangers and / or cation exchangers. These are used in Mц vxij, respectively. -form. In this case, it is most advantageous to use a continuous or semi-continuous device, where it is filled through the tower. the polyether or polyether diol, respectively. polyether, optionally a solution thereof. It is desirable to temper the towers to make the polyether less viscous. The most suitable order of ion exchangers is anion exchange resin. In addition to trapping any anion residues, the anion exchanger also has a decolorizing effect on the polyether or copolyether. Sodium and potassium ions are then virtually quantitatively captured on the cation exchange resin. The ion exchange capacity of the ion exchangers can be determined whether or not it can be checked by titration with acid, respectively. The sodium or potassium content of the product is definitively determined, usually photometrically.

Regeneration of ion exchangers is carried out with aqueous solutions of acid or hydroxide with conc. 3 to 5% by weight, and washed into a neutral reaction with distilled water. After removal of acids and bases, the ion exchanger is flushed with lower alcohol or acetone to remove moisture. The process may be combined with the acid precipitation as described above after removal of the salt by filtration. In these cases, a sodium and potassium content of less than 1.1% by weight is achieved. (1 p.p.m.) and ensure a long service life of the ion exchangers.

Said process achieves high purity of polyethers or polyether diols and copolyethers which are suitable for preparing polyurethanes, with destroyed energy costs compared to water-based processes.

Further details of the refining process of the present invention are evident from the examples, which, however, do not exhaust all possible combinations of uses.

Example 1

Two boxes with an inner diameter of 3 cm and a height of 92 cm, jacketed for tempering with recirculated tempering

- 7 241 409 liquids are filled with ion exchangers. Anion exchange column I (Lewatit S-10) and a cation exchange column II (Ostion KS). The volume of ionic ions is 500 cm each. Ion exchange resins are activated 1500 ^cc of aqueous sodium hydroxide solution of concentration. 5 wt. hydrochloric acid with conc. 3% by weight, at a flow rate of 3 h. the ion exchangers are rinsed with distilled water by introducing 1.5 volumes per volume of ion exchange resin per hour for 7 h at 80 ° C. After removal of residual sodium hydroxide, respectively. hydrochloric acid (as determined by pH monitoring), the ion exchangers are rinsed with isopropyl alcohol for 1 500 cm each and are used to deionize the crude water-soluble products of the polyaddition or copolyaddition of olefin oxides C8 to C18. The results of analyzes of these products after refining, in particular from the alkali metal ions on the anion exchanger-cation exchanger are given in Table 1. The raw crude water-soluble products have a total potassium hydroxide and sodium hydroxide content determined by titration of 0.20-0.30% by weight. (ie 2,000 to 3,000 ppm).

Accordingly, polyglycols, respectively. polyethers with mol. weight over 1000, resp. the copolyethers above 1500 are too viscous at room temperature, deionizing in the form of n-butanol or aqueous solution with conc. 10 to 30 wt.%, At 80 ° C. After deionization, the solvent is removed by rotary evaporation under reduced pressure. 1 dnP of the polyether is refined on the cation so that the potassium cation content is below 3 · 10 -4% by weight.

(below 3 p »p« m.).

After tests for the preparation of polyurethanes with 4,4'-diphenylmethane diisocyanate in a nitrogen atmosphere, linearly soluble polyurethanes soluble in organic solvents such as e.g. in dimethylformamide ·

Table 1

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Type of crude product of polyaddition or copolyaddition

Molecular weight [gunol * ¹ ]

Content of etoxamer groups [% by weight] polyethylene glycol polyethylene glycol polyethylene glycol polypropylene. ethylene glycol copolyether of ethylene oxide and. propylene oxide ethylene oxide-propylene oxide copolymer ethylene oxide-propylene oxide copolyether

650

030

600

920

990

500

340

100

100

100

42.5

69.3

The content of the de-ionizing ^'[0 l.1 ^"4% by weight in ppm ÍM Γωΐ LHaj LKj 0,2 1,13 0.0 o, 3! 0.1 0.65 0,2 1,1 0,1 0,54 ^! 0,0 0,57 0,2 1,6

Example 2

Copolymer of propylene oxide and ethylene oxide with mol. of a weight of 1 200 g.mol ', containing' 52% by weight of ethoxylate units and potassium hydroxide 'of 0,22% by weight. (2,200 ppm) is treated by adding 0.59 moles of sulfuric acid per mole of potassium hydroxide; 0.39 mol of phosphoric phosphoric acid per 1 mol of potassium hydroxide; 1.09 mol of hydrochloric acid per mol of potassium hydroxide; 1.17 .mol of butyric acid, acetic acid, and ^0, 4 ¹ mol of ^alkyl ester se.liny set ^{L 1} to each possible aprefúkanim potassium ^hydroxide with carbon dioxide.

After 30 minutes of acid deposition, respectively. of the acid of that of the ^full 25 ° ^t e m ^ 0 for the input of a solution of / or. extended LCY foreign ^ ⁱ e 9241 409 Vayu to 80 DEG C. After 30 minutes, the resulting precipitate filtered. The potassium chloride precipitate is best filtered.

Moreover, in the order KC1> K ^ PO ^ ^ 2θθ3

The use of formic acid and betic acid practically does not produce a precipitate. The product after filtration is determined by ion-selective electrodes on ions; % with 0.012 wt.

followed by an amount of potassium (170 p.p.m.), with sulfuric acid 0.0205 wt. % (205 p.p.m.), with hydrochloric acid 0.0392 wt. (392 p.p.m.), with carbon dioxide of 0.0070 wt. (70 p.p.m.), with oxalic acid 0.0166 wt. % (166.5 p.p.m.), with formic acid and acetic acid 0.18 to 0.21 wt. (1,850 to 2,100 p.p.m.).

After filtration, the products are deionized on a cation exchange resin (sulfonated styrene-divinylbenzene copolymer resin in β-Pj form). In doing so, the refining power? of cation exchanger when using hydrochloric acid increases fourfold (the purification efficiency of 10 dm ^ of copolyether per 1 day of cation exchanger) and tenfold when using phosphoric acid.

Example 3

Copolymer polyether with mol. weight of 1200 gmol ^- ^ om a content of 30% by weight, etoxamérových units and residues of catalyst of polyaddition in the amount of 0.23% by weight, essentially potassium hydroxide with admixture of sodium hydroxide were mixed with various amounts of orthophosphoric acid. After addition of the trihydrogenphosphoric acid, the polyether is stirred for 10 min at room temperature and then for 30 min at 120 ° C and filtered hot. Sodium and potassium ions are determined spectrophotometrically in the filtrate.

Results of the effect of the amount of trihydrogenphosphoric acid added to 500 g of samples of copolymer polyethers with mol.

- 1 by weight of 1 200 g.mol and containing 30% by weight of etoxamer units and 0,23% by weight of potassium hydroxide with admixtures of sodium hydroxide are summarized in Table 2.

Table 2 241 409

Addition of HoP0. 1.0 1.5 • 2.0 2.5 2.7 2.9 3.1 3.3 w Add ok H, J ^P ° ⁴ 0.42 0.63 0.84 1.05 1.13 1.22 1.3 1.33 .mu.mol .mol ^TJJ After refining Γ (+) Ί content [KJ Γΐ .10 ~ ⁴ % hmo ^ie > 190 173 152 3.7 3.0 i 0.0 .1 1 0.0 0,0! Contents W On the i: ^[ .1 o ⁴  wt 3.3 2.1 1.9 0.0 0.0 0.0 0.0 0.0 pH. 9.9 7.7 6.4 4.5 3.3 ’- - -

The amount of trihydrogenphosphoric acid required. other acid can be determined? direct titration with an acid at a pH decrease of below 6. If the pH falls below 6.0, the product was added calcium carbonate (e.g., 0.6% wt.) to neutralize the acid and ^{L p} néj then about the 'heated to a · -tepotu ¹²⁰ ° C and mieišania a solution of the ďalšorn and ^{after 10} min / odfiltouje. In BC ^and fall, the water-soluble polyéter'před refining is tmavosfarbený, it is advisable before adding. acid admixture? 1.5. % by weight of activated carbon and after 20 min the solution was filtered off. Is it possible to combine filtration of the activated carbon? with filtration after neutralization of the base. By this operation, the solution is decolorized. Similar discoloration is achieved. application of sodium sulfite. The prapadoch overdose of the pushes, the ^p re ^{it to} the anion ^of LCO ^O N E.

C ^u p ^s rava Selinou ^{dihydroquinazolin} tr ro en ^{f g f} Orečný the person ^used EURO m ^and 1 mole of ^{s when} n ^s is the fundamental kata ^ 1 ^ of hours required úalsie purification of polyethers or copolyethers ion-exchange.

Claims (1)

OBJECT OF THE INVENTION 241 409 Process for refining at least sparingly water-soluble polyethers and / or copolyethers based on ethylene oxide and / or pxylene oxide from a catalyst, in particular alkali metal ions or undesirable impurities formed during production, characterized in that the refining is carried out with acids or acid-reacting substances. of an ion exchange group, inorganic or polybasic organic acids, preferably trihydrogenphosphoric acid, in an amount of 0.3 to 2.0, preferably 0.8 to 1.1 moles per mole of catalyst, optionally in the presence of a solvent, a sorbent or a chemical decolorizer followed by removal insoluble matter by filtration or blasting.