JP3076726B2 - Method for producing polyoxyalkylene polyol - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for recovering a polyoxyalkylene polyol polymerization catalyst and a method for producing a polyoxyalkylene polyol. Specifically, the present invention is a method for recovering a polymerization catalyst for a polyoxyalkylene polyol used as a raw material for a polyurethane resin or a surfactant,
And a method for producing a polyoxyalkylene polyol by ring-opening addition polymerization of an alkylene oxide using a recovered catalyst.

[0002]

2. Description of the Related Art A polyoxyalkylene polyol used as a raw material for polyurethane is usually obtained by ring-opening addition polymerization of an alkylene oxide in the presence of an active hydrogen compound initiator and an alkaline catalyst. In the production of polyoxyalkylene polyol, various proposals have hitherto been made for the purpose of improving productivity and improving product quality.

[0003] The rate of alkylene oxide addition polymerization during the production of the polyoxyalkylene polyol may increase when the concentration of the alkylene oxide during the reaction is high, when the reaction temperature is high, or when the amount of the alkali metal compound polymerization catalyst is increased. Are known. When productivity is improved by such a method, the amount of unsaturated bonds due to side reactions increases at the same time. The unsaturated bond is derived from a monol having a terminal double bond formed by a side reaction of propylene oxide, which is an alkylene oxide, and this monool causes deterioration of the quality of the produced polyoxyalkylene polyol, and is converted into a polyurethane resin. Undesirable results such as deterioration of physical properties at the time are brought.

[0004] For this reason, studies have been made on polymerization conditions that affect the increase in the amount of monool produced.
0, No. According to 2,121-126, (1993), when the reaction is carried out at a high temperature, the degree of increase in the amount of unsaturated bond is the largest, and the concentration of alkylene oxide and the concentration of potassium hydroxide polymerization catalyst are dependent on the amount of unsaturated bond. The effect is stated to be relatively small. However, there is a limit in the pressure resistance performance of the reactor, and it is relatively difficult to increase the concentration of the alkylene oxide.

Although it is very easy to increase the concentration of the potassium hydroxide polymerization catalyst, the polymerization catalyst is discarded after being separated from the crude polyoxyalkylene polyol by acid neutralization or washing with water after use. As the amount of the polymerization catalyst used increases, the cost of the product increases, and the basic unit deteriorates due to the increase in the amount of the product attached to the catalyst neutralizing salt or the amount of washing water.

Further, there has been proposed a method for producing a polyoxyalkylene polyol having a small amount of unsaturated bond by changing the type of the alkali metal compound polymerization catalyst (USP 3, US Pat.
393,243). In this case, since the production amount of monool is suppressed, there is a characteristic that quality is not deteriorated even if productivity is improved by a high-speed reaction. In the above reference, a cesium compound catalyst is used for the production of the polyoxyalkylene polyol to reduce the amount of unsaturated bonds, and a neutralization step of adding a neutralizing agent composed of water and oxalic acid is performed. However, there is no description on the recovery of cesium salts. Cesium compounds are very expensive and this method has the disadvantage that it is not economical when used industrially.

Various techniques for recovering a cesium compound catalyst have been studied. For example, a crude polyoxyalkylene polyol polymerized in the presence of a cesium compound catalyst is neutralized by adding an organic acid such as oxalic acid and water, the resulting cesium salt is separated, and the separated cesium salt and attached to it. This is a technique of sintering a mixture of polyoxyalkylene polyols to form cesium oxide, and then recovering it as cesium hydroxide by a hydration reaction, and reusing the recovered cesium hydroxide as a catalyst for polyoxyalkylene polyol (Japanese Patent Application Hei 04-331996). However, this method has a problem of a cost of an organic acid used for neutralization and a problem of a cost of a fuel used for sintering, and does not satisfy the demand for cost reduction.

Further, a crude polyoxyalkylene polyol polymerized in the presence of a cesium compound catalyst is used as it is.
Alternatively, the aqueous solution of the cesium salt compound obtained by neutralizing the crude polyoxyalkylene polyol with at least one of an organic acid or a mineral acid and water is brought into contact with a cation exchange resin to adsorb cesium ions on the cation exchange resin, Next, there is a technique of recovering cesium hydroxide as a polyoxyalkylene polyol polymerization catalyst using a basic eluent (Japanese Patent Application Nos. 04-331997 and 04-33309).
4). However, such a method also has a problem in that the eluent is mixed into the cesium hydroxide aqueous solution and the purity of the cesium hydroxide is reduced, so that the performance as a polyoxyalkylene polyol polymerization catalyst is reduced.

[0009]

An object of the present invention is to efficiently convert a crude polyoxyalkylene polyol obtained by polymerizing an alkylene oxide in the presence of an alkali metal compound catalyst into a polyoxyalkylene polyol polymerization catalyst.
It is an object of the present invention to provide a method for economically recovering and further provide a method for producing a polyoxyalkylene polyol by reusing the recovered polyoxyalkylene polyol polymerization catalyst.

[0010]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, have found that a crude polyoxysiloxane obtained by polymerizing an alkylene oxide by a specific method in the presence of an alkali metal compound catalyst. A polyoxyalkylene polyol polymerization catalyst can be efficiently and economically recovered from an alkali metal salt obtained after neutralizing an alkylene polyol with a mineral acid or an organic acid, and using the recovered polyoxyalkylene polyol polymerization catalyst As a result, it was found that the polymerization of the polyoxyalkylene polyol was possible again, and the present invention was finally completed.

That is, a first object of the present invention is to provide a crude polyoxyalkylene polyol containing an alkali metal compound catalyst with a neutralizing step of adding a neutralizing agent composed of water and a mineral acid or an organic acid. After dehydration and drying, a desalting step of filtering the precipitated alkali metal salt, and then contacting the obtained alkali metal salt as an aqueous alkali metal salt solution with an OH-type anion exchange resin to remove a mineral acid or an organic acid anion A step of recovering a polyoxyalkylene polyol polymerization catalyst by ion exchange to be adsorbed, and then using the recovered polyoxyalkylene polyol polymerization catalyst to subject the active hydrogen compound initiator to ring-opening addition polymerization of an alkylene oxide. A process for producing an oxyalkylene polyol, comprising: A second object of the present invention is a method for producing a polyol, wherein an aqueous alkali metal salt solution is added to a mixture of an alkali metal salt and a polyoxyalkylene polyol after the desalting step of the first invention with water or water and an organic compound. A method for producing a polyoxyalkylene polyol characterized by being an aqueous alkali metal salt solution phase obtained by adding a mixture of solvents and separating the mixture into a polyoxyalkylene polyol phase and an aqueous alkali metal salt solution phase. A third object is a method for recovering a polymerization catalyst for a polyoxyalkylene polyol, which comprises a neutralization step, a desalination step, and a recovery step according to the first invention.

In the present invention, the alkali metal compound catalyst includes metal sodium, sodium hydroxide, metal potassium, potassium hydroxide, metal rubidium, rubidium hydroxide, metal cesium, cesium hydroxide, or sodium hydroxide, potassium hydroxide, Rubidium hydroxide or cesium hydroxide monohydrate may be mentioned, but preferably metal rubidium, rubidium hydroxide, metal cesium, cesium hydroxide, or rubidium hydroxide or cesium hydroxide monohydrate, Preferably, it is cesium metal, cesium hydroxide or its monohydrate, but most preferably it is cesium hydroxide or its monohydrate.

After these catalysts are added to the active hydrogen compound initiator or the polyoxyalkylene polyol,
It is desirable to carry out dehydration or dehydrogenation by heating and to alcoholate the active hydrogen compound to carry out alkylene oxide addition polymerization, but it may be used as it is in some cases. Even if the alkali metal compound catalyst is recovered by the recovery step of the present invention, there is no problem.

The amount of the alkali metal compound catalyst is as follows:
The range is preferably 0.01 to 5 parts by weight based on 100 parts by weight of the polyoxyalkylene polyol after the alkylene oxide addition polymerization.

Examples of the crude polyoxyalkylene polyol in the present invention include those having any molecular weight obtained by addition polymerization of an alkylene oxide in the presence of a known active hydrogen compound initiator in the presence of an alkali metal compound catalyst. Known active hydrogen compound initiators include, for example, monohydric alcohols such as methanol, ethanol, and butanol.
2 such as propylene glycol and 1,4-butanediol
Polyhydric alcohols such as polyhydric alcohols, glycerin, pentaerythritol, sorbitol, and sugar; alkanolamines such as monoethanolamine, diethanolamine and triethanolamine; aliphatic amines such as ethylenediamine; aniline, toluylenediamine, and diphenylmethanediamine There are aromatic amines, phenol compounds such as bisphenol A and novolak, and water.
Further, polyoxyalkylene polyols obtained by adding a low mole number of an alkylene oxide to these active hydrogen compound initiators by a known method can also be used as the active hydrogen compound initiator.

The crude polyoxyalkylene polyol is
An active hydrogen compound initiator obtained by subjecting an alkylene oxide to ring-opening addition polymerization using an alkali metal compound catalyst, and a part of the terminal hydroxyl groups of the polyoxyalkylene polyol has a structure of an alkali metal alcoholate, and is self-made. It doesn't matter if it's a thing or a purchase.

Examples of the alkylene oxide in the present invention include known ones such as propylene oxide, ethylene oxide, butylene oxide, and styrene oxide, and these can be used in combination of two or more.
The amount of the alkylene oxide to be added is not particularly limited, but is usually preferably in the range of 1 to 120 mol per 1 mol of the hydroxyl group in the active hydrogen compound initiator. These addition polymerizations can be carried out under known methods and conditions.

The crude polyoxyalkylene polyol can be neutralized by adding water and a neutralizing agent at 50 to 120 ° C. Water is industrial water, ion-exchanged water, distilled water or the like depending on the purpose.
0.05 to 30 parts by weight per 100 parts by weight is preferred.
Neutralizing agents include mineral acids, for example, phosphoric acid, hydrochloric acid, sulfuric acid, sulfurous acid, carbonic acid, organic acids, for example, formic acid, oxalic acid, succinic acid, acetic acid, maleic acid. These neutralizers can be used alone or in combination of two or more.

In some cases, after the above neutralization treatment, if necessary, an adsorption treatment can be carried out using an adsorbent. As the adsorbent, synthetic magnesium silicate is preferably used, and Tomix-AD600NS, Tomix-AD6
00B, Tomix AD-300 (manufactured by Tomita Pharmaceutical Co., Ltd.), Kyoward 400, and Kyoward 600 (manufactured by Kyowa Chemical Industry Co., Ltd.).

The method for recovering the polyoxyalkylene polyol polymerization catalyst of the present invention is as follows. Water and a neutralizing agent are added to the crude polyoxyalkylene polyol obtained by polymerizing the alkylene oxide in the presence of the alkali metal compound catalyst to adjust the pH to 3.0 to 9.0, and then the added water is added to 50 to 90%.
After the alkali metal salt precipitated by the dehydration and drying treatment at 120 ° C. under reduced pressure is filtered off, water is added to obtain an alkali metal salt aqueous solution. However, a small amount of polyoxyalkylene polyol is usually attached to this alkali metal salt, and water or a mixture of water and an organic solvent is added to the alkali metal salt obtained by filtration, and the mixture is usually stirred and mixed at 10 to 100 ° C. It is preferable to allow it to stand still. After liquid separation into a polyoxyalkylene polyol phase and an aqueous alkali metal salt phase, the aqueous alkali metal salt solution is brought into contact with an OH type anion exchange resin to adsorb mineral acid or organic acid anions, thereby polymerizing the polyoxyalkylene polyol. Recover the catalyst. Examples of the organic solvent used for separating the polyoxyalkylene polyol and the alkali metal salt include aliphatic hydrocarbons such as n-hexane, alicyclic hydrocarbons such as cyclopentane, benzene,
Examples thereof include aromatic hydrocarbons such as toluene, and halogenated hydrocarbons such as carbon tetrachloride, chloroform, and methylene chloride.

It is also desirable to mix and use the polyoxyalkylene polyol phase separated by the above method with a crude polyoxyalkylene polyol or the like after polymerization, since loss in the polyoxyalkylene polyol purification step is reduced.

The concentration of the aqueous alkali metal salt solution to be treated with the anion exchange resin is not particularly limited.
Usually, about 0.01 to 50% by weight is preferably used. The use of an aqueous alkali metal salt solution outside this concentration range does not impair the gist of the present invention.

As the anion exchange resin in the present invention, a resin having a structure in which a styrene-divinylbenzene copolymer is used as a carrier and a quaternary ammonium salt compound is used as an ion exchange group in a side chain is preferably used. Further, both the gel type and the macroporous type can be used in the present invention. This type of ion exchange resin is Levatit MP500, M500, M504, MP6.
00, MP500A (manufactured by Bayer), Diaion PA406, PA408, PA412 (manufactured by Mitsubishi Kasei), Amberlite IRA430, IRA45
8. The product is commercially available under various trade names such as IRA900 (both manufactured by Rohm and Haas). These anion exchange resins are used after a part or all of them are converted to an OH type as a counter anion of a quaternary ammonium cation by a conventionally known method. On the other hand, it is also possible to purchase and use an anion exchange resin that has already been converted to the OH type. The use temperature of the ion exchange resin is not particularly limited, but is usually preferably used in the range of 10 to 100 ° C.

The aqueous alkali metal salt solution is ion-exchanged,
Since it is converted to an aqueous alkali metal hydroxide solution, the aqueous alkali metal hydroxide solution can be used as it is or after being concentrated to a desired concentration as a catalyst for an alkali metal compound in the polymerization of alkylene oxide. Further, the alkali metal hydroxide aqueous solution can be dehydrated and used in the form of the alkali metal compound catalyst in the form of the above-mentioned polyoxyalkylene polyol in the form of a solid alkali metal hydroxide. The alkali metal compound catalyst thus recovered can be used again as a polyoxyalkylene polyol polymerization catalyst, then recovered again, and used repeatedly as a polyoxyalkylene polyol polymerization catalyst.

The polyoxyalkylene polyol is obtained by removing the polyoxyalkylene polyol polymerization catalyst in the crude polyoxyalkylene polyol and further purifying it. This production method is the same as the above-described production method of the crude polyoxyalkylene polyol, but the production of the polyoxyalkylene polyol in the present invention uses the polyoxyalkylene polyol polymerization catalyst already used through the recovery step. . When the recovered polyoxyalkylene polyol polymerization catalyst is used, it is a dehydrated solid or an aqueous solution having an arbitrary concentration, and its form is not limited.

[0026]

The present invention will be described below with reference to examples. Example 1 A reactor purged with nitrogen was charged with 150 g of glycerin as an active hydrogen compound (initiator) and 113 g of a 50% aqueous cesium hydroxide solution as a catalyst. Next, the temperature inside the reactor was raised to 105 ° C., and the dehydration rate was 90
%, And 9650 g of propylene oxide (hereinafter abbreviated as PO) as an alkylene oxide was gradually charged under the conditions of an internal temperature of 105 ° C. and an internal pressure of 4 kg / cm ² G, and the reaction was carried out in 13 hours. finished. After completion of the reaction, unreacted PO in the system was removed under reduced pressure to obtain 9820 g of crude polyoxyalkylene polyol (hereinafter abbreviated as crude polyol). Next, 10 wt% of water, cesium hydroxide and an equimolar amount of phosphoric acid were added to the crude polyol for neutralization. After neutralization, water was removed from the crude polyoxyalkylene polyol, and the precipitated cesium salt was separated and removed. The purified polyoxyalkylene polyol from which the cesium salt has been removed has a hydroxyl value of 28 mgKOH / g and a viscosity of 1100 cps.
/ 25 ° C. Next, a 7% by weight aqueous solution of caustic soda, which is 50 times the ion exchange capacity, was passed through 200 ml of a chlorine-type anion exchange resin (LEVATIT MP500) to obtain O 2.
H-type anion exchange resin (Revatit MP500) 200
ml were obtained. Water was added to the cesium salt to form a 15% aqueous solution (hereinafter abbreviated as aqueous solution A), and the phosphate ion concentration was measured to be 54.7 mg / ml. Next, 100 ml of the aqueous solution A and 200 ml of an OH-type anion exchange resin (Levatit MP500) were placed in the flask and stirred at 20 ° C. for 15 minutes to adsorb phosphate ions. As a result of filtering this aqueous solution, a cesium hydroxide aqueous solution containing a very small amount of cesium salt (phosphate ion concentration: 1.10 mg / ml) and having a purity of 98 wt% was obtained. 99% recovery of cesium.

Example 2 1300 g of ethylene oxide was added to 7850 g of the crude polyol obtained in Example 1 at an internal temperature of 105 ° C. and an internal pressure of 4 kg / cm ² G.
And the reaction was completed in 4 hours. The hydroxyl value of the polyoxyalkylene polyol purified according to Example 1 was 24 mgKOH / g, and the viscosity was 1300 cps.
/ 25 ° C. Water was added to this cesium salt to form a 15% aqueous solution (hereinafter abbreviated as aqueous solution B). In a flask, 100 ml of aqueous solution B was replaced with an OH-type ion-exchange resin (Levatit MP500) 200 obtained in the same manner as in Example 1.
Then, the mixture was stirred at 20 ° C. for 15 minutes to adsorb phosphate ions. As a result of filtering this aqueous solution, a cesium hydroxide aqueous solution having a purity of 99 wt% containing a very small amount of cesium salt was obtained. 96% recovery of cesium.

Example 3 To 500 g of a pentaerythritol PO adduct (having a hydroxyl value of 450 mg KOH / g), 70 g of a 50% cesium hydroxide aqueous solution was charged as a catalyst, and PO was added according to the method of Example 1. After completion of the reaction, unreacted PO in the system was removed under reduced pressure to obtain 7900 g of a crude polyoxyalkylene polyol (hereinafter abbreviated as crude polyol). The hydroxyl value of the polyoxyalkylene polyol purified according to Example 1 was 28 mgKOH / g, and the viscosity was 1,400 cps / 25 ° C. Water was added to this cesium salt to form a 15% aqueous solution (hereinafter abbreviated as aqueous solution C).
1 and 200 ml of an OH-type anion exchange resin (Levatit MP500) obtained in the same manner as in Example 1 were added and stirred at 20 ° C. for 15 minutes to adsorb phosphate ions. As a result of filtering this aqueous solution, a purity of 98 wt.
% Cesium hydroxide aqueous solution was obtained. 96% recovery of cesium.

Example 4 77 g of a 50% aqueous rubidium hydroxide solution was charged as a catalyst, and PO was added to glycerin according to the method of Example 1.
After completion of the reaction, unreacted PO in the system is removed under reduced pressure, and crude polyoxyalkylene polyol (hereinafter abbreviated as crude polyol).
9820 g are obtained. Next, the crude polyol was neutralized by adding 5% by weight of water, rubidium hydroxide, and equimolar phosphoric acid.
After neutralization, the added water is dehydrated and removed to obtain a rubidium salt. Water was added to the rubidium salt to form a 15% aqueous solution (hereinafter abbreviated as aqueous solution D), and 100 ml of aqueous solution D was placed in a flask and OH-type anion exchange resin 200 obtained in the same manner as in Example 1.
The mixture is stirred at 20 ° C. for 15 minutes to adsorb phosphate ions. The aqueous solution is filtered to obtain a 97 wt% pure rubidium hydroxide aqueous solution containing a small amount of a rubidium salt.
95% recovery of cesium.

Example 5 As a catalyst, 40 g of a 50% aqueous potassium hydroxide solution was charged, and PO was added to glycerin according to the method of Example 1. After completion of the reaction, unreacted PO in the system was removed under reduced pressure, and crude polyoxyalkylene polyol (hereinafter abbreviated as crude polyol) 9
820 g are obtained. Next, the crude polyol is neutralized by adding 5% by weight of water, potassium hydroxide and equimolar phosphoric acid, and after neutralization, the added water is dehydrated and removed to obtain a potassium salt. Water was added to the potassium salt to form a 15% aqueous solution (hereinafter abbreviated as aqueous solution E).
200 ml of the OH-type anion exchange resin obtained in the same manner as described above is added and stirred at 20 ° C. for 15 minutes to adsorb phosphate ions. The aqueous solution is filtered to a purity of 97 with a very small amount of potassium salt.
A wt% aqueous solution of potassium hydroxide is obtained. 95% recovery of cesium.

Example 6 According to Example 2, the produced crude polyoxyalkylene polyol was neutralized by adding 5% by weight of water, cesium hydroxide and equimolar phosphoric acid. After neutralization, the added water is dehydrated and removed, and the polyoxyalkylene polyol is reduced to 40 w by filtration.
A cesium salt having attached t% was obtained. Water at 70 ° C. was added to the obtained cesium salt (to which the polyoxyalkylene polyol adhered), and the mixture was stirred and mixed at 80 ° C., and allowed to stand still to separate a lower cesium phosphate aqueous solution phase. Cesium phosphate aqueous solution phase 15%
(Hereinafter abbreviated as aqueous solution F), and the phosphate ion concentration was measured and found to be 63.2 mg / ml. Next, 100 ml of the aqueous solution F and an OH-type anion exchange resin (Levatit MP5) obtained in the same manner as in Example 1 were placed in the flask.
00) 200 ml was added and stirred at 20 ° C. for 15 minutes to adsorb phosphate ions. As a result of filtration of this aqueous solution, a very small amount of cesium salt was contained (phosphate ion concentration: 1.26 mg /
ml) A cesium hydroxide aqueous solution having a purity of 98 wt% was obtained. 90% recovery of cesium.

Example 7 According to Example 3, 5% by weight of water, cesium hydroxide and an equimolar amount of phosphoric acid were added to the produced crude polyoxyalkylene polyol for neutralization. After neutralization, the added water is dehydrated and removed, and the polyoxyalkylene polyol is reduced to 40 w by filtration.
A cesium salt having attached t% was obtained. Water at 70 ° C. was added to the obtained cesium salt (to which the polyoxyalkylene polyol adhered), and the mixture was stirred and mixed at 80 ° C., and allowed to stand still to separate a lower cesium phosphate aqueous solution phase. Cesium phosphate aqueous solution phase 15%
(Hereinafter abbreviated as aqueous solution G), and the phosphate ion concentration was measured to be 63.2 mg / ml. Next, 100 ml of the aqueous solution G and an OH-type anion exchange resin (Levatit MP5) obtained in the same manner as in Example 1 were placed in the flask.
00) 200 ml was added and stirred at 20 ° C. for 15 minutes to adsorb phosphate ions. At this time, as a result of filtering the aqueous solution,
Contains a very small amount of cesium salt (phosphate ion concentration 1.26mg
/ Ml) A cesium hydroxide aqueous solution having a purity of 98 wt% was obtained. 75% recovery of cesium.

Example 8 The cesium hydroxide aqueous solution obtained in Example 6 (aqueous solution F)
Was concentrated to obtain a cesium hydroxide solution having a concentration of 50% by weight. Active hydrogen compound (initiator) in a reactor purged with nitrogen
Of glycerin and 113 g of a 50% aqueous cesium hydroxide solution as a catalyst. Next, the temperature inside the reactor was raised to 105 ° C., and dehydration was continued under a reduced pressure of 10 mmHg until the dehydration rate exceeded 90%.
Under the conditions of an internal pressure of 4 kg / cm ² G, alkylene oxide was converted to propylene oxide (hereinafter abbreviated as PO) 9650.
g was gradually charged, and the reaction was completed in 13.5 hours. After completion of the reaction, unreacted PO in the system was removed under reduced pressure, and crude polyoxyalkylene polyol (hereinafter abbreviated as crude polyol) 98
20 g were obtained. Next, the crude polyol was neutralized by adding 5% by weight of water, cesium hydroxide and an equimolar amount of phosphoric acid.
After neutralization, the added water was dehydrated and removed, and the cesium salt was filtered off to obtain a polyoxyalkylene polyol. Hydroxyl value 28m
gKOH / g, viscosity 1100 cps / 25 ° C., and the obtained purified polyoxyalkylene polyol had the same hydroxyl value and viscosity as those of Example 1.

Example 9 A reactor purged with nitrogen was charged with 300 g of glycerin as an active hydrogen compound (initiator) and 80 g of a 50% aqueous cesium hydroxide solution as a catalyst. Next, the temperature in the reactor was set to 1
The temperature was raised to 05 ° C and the dehydration rate was 90% under reduced pressure of 10 mmHg.
After dehydration is continued until the internal temperature exceeds 105 ° C and internal pressure 4
Under the condition of kg / cm ² G, 1360 g of propylene oxide (hereinafter abbreviated as PO) as an alkylene oxide was gradually charged, and the reaction was completed in 150 minutes. After completion of the reaction, unreacted PO in the system was removed under reduced pressure to obtain 1700 g of crude polyoxyalkylene polyol (hereinafter abbreviated as crude polyol). Next, the crude polyol was neutralized by adding 5% by weight of water, cesium hydroxide and an equimolar amount of phosphoric acid. After neutralization, the added water was dehydrated and removed to obtain a cesium salt. Water is added to the obtained cesium salt to give a 15% aqueous solution (hereinafter abbreviated as aqueous solution H).
When the phosphate ion concentration was measured, 54.5 mg /
ml. Next, the aqueous solution H100m was placed in the flask.
1 and 200 ml of an OH-type anion exchange resin (Levatit MP500) obtained in the same manner as in Example 1 were added and stirred at 20 ° C. for 15 minutes to adsorb phosphate ions. As a result of filtering this aqueous solution, a cesium hydroxide aqueous solution containing a very small amount of cesium salt (phosphate ion concentration: 1.09 mg / ml) was obtained.

[0035]

According to the method of the present invention, a polyoxyalkylene polyol polymerization catalyst can be efficiently recovered from a purified salt obtained from a crude polyoxyalkylene polyol, and economic efficiency can be improved by reusing the recovered catalyst. Contribute to improvement.

────────────────────────────────────────────────── (5) References JP-A-7-70308 (JP, A) JP-A-4-175338 (JP, A) JP-A-62-267325 (JP, A) US Pat. No. 4,985,551 (US) U.S. Pat. No. 4,764,567 (US, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 65/00-65/48 WPI / L

Claims (9)

(57) [Claims] 1. A neutralization step of adding a neutralizing agent composed of water and a mineral acid or an organic acid to a crude polyoxyalkylene polyol containing an alkali metal compound catalyst, and then the resulting liquid is dehydrated and dried, and then the precipitated alkali metal A desalting step of filtering the salt, and then contacting the obtained alkali metal salt as an aqueous alkali metal salt solution with an OH type anion exchange resin, thereby adsorbing a mineral acid or an organic acid anion. A step of recovering the polyol polymerization catalyst, and then a step of producing a polyoxyalkylene polyol, which comprises subjecting the active hydrogen compound initiator to ring-opening addition polymerization using the recovered polyoxyalkylene polyol polymerization catalyst. A method for producing a polyoxyalkylene polyol. 2. The method for producing a polyoxyalkylene polyol according to claim 1, wherein the alkali metal compound catalyst is cesium metal, cesium hydroxide or a monohydrate thereof. 3. The method for producing a polyoxyalkylene polyol according to claim 1, wherein the alkali metal compound catalyst is metal rubidium, rubidium hydroxide or a monohydrate thereof. 4. An aqueous alkali metal salt solution is added to the mixture of the alkali metal salt and the polyoxyalkylene polyol by adding water or a mixture of water and an organic solvent to the mixture of the alkali metal salt and the polyoxyalkylene polyol. 2. The method for producing a polyoxyalkylene polyol according to claim 1, wherein the aqueous solution is an alkali metal salt aqueous solution phase obtained by liquid separation into a metal salt aqueous solution phase. 5. The method for producing a polyoxyalkylene polyol according to claim 4, wherein the alkali metal compound catalyst is cesium metal, cesium hydroxide or a monohydrate thereof. 6. The method for producing a polyoxyalkylene polyol according to claim 4, wherein the alkali metal compound catalyst is metal rubidium, rubidium hydroxide or a monohydrate thereof. 7. The neutralizing step, the desalting step according to claim 1,
A method for recovering a polyoxyalkylene polyol polymerization catalyst, comprising a recovery step. 8. The method for recovering a polyoxyalkylene polyol polymerization catalyst according to claim 7, wherein the alkali metal compound catalyst is cesium metal, cesium hydroxide or a monohydrate thereof. 9. The method for recovering a polymerization catalyst for a polyoxyalkylene polyol according to claim 7, wherein the alkali metal compound catalyst is metal rubidium, rubidium hydroxide or a monohydrate thereof.