JPH07258403A - Purification of polyether - Google Patents

Abstract

PURPOSE:To provide a method for purifying a polyether, capable of significantly reducing its adsorption time and the amount of the magnesium silicate to be used for its purification, compared to conventional methods. CONSTITUTION:This method for purifying a polyether is such that, when an adsorbent and water are added to a crude polyether produced by addition polymerization of an alkylene oxide to an active hydrogen compound in the presence of a basic catalyst to conduct an adsorption treatment of the basic catalyst, magnesium silicate containing <=0.5wt.% of sodium is used as the adsorbent to purify the crude polyether.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for efficiently removing a basic catalyst from a polyether produced in the presence of the basic catalyst.

[0002]

Polyether is used in large amounts as a raw material for polyurethane foams, resins, surfactants, cosmetic materials and the like. To use it as a raw material, 10 ppm of a basic catalyst in polyether is used. It is necessary to reduce to Conventionally, as a method of removing the basic catalyst from the polyether, a method of neutralizing the basic catalyst with an acidic substance, and then removing the neutralized salt formed by filtration (Japanese Patent Publication No. 38-207442, etc.), solid A method of adsorbing and filtering a basic catalyst on an adsorbent (for example, magnesium silicate) (Japanese Patent Publication No. 52-10018) is proposed. At present, a method using a solid adsorbent is common.

[0003]

With the increase in the size of polyether production facilities, there is a demand for more efficient removal of the basic catalyst from the polyether. Magnesium silicate used as a conventional adsorbent has a sodium content of 1 to 1.
It is 0% by weight and contains a large amount of sodium. Therefore, the adsorption capacity of the basic catalyst as an adsorbent is significantly lower than the theoretical adsorption capacity.
A large amount of magnesium silicate is required to reduce the amount of PM to less than PM, and as a result, there have been problems such as a decrease in the yield of polyether and an increase in processing cost due to an increase in filtration residue. Further, when a large amount of sodium is contained, there is a problem that when water and magnesium silicate are mixed and then mixed with crude polyether, sodium is eluted into water and the adsorption time becomes long.

[0004]

Means for Solving the Problems The present inventors have arrived at the present invention as a result of extensive studies on a method for efficiently removing a basic catalyst from a polyether. That is, the present invention adsorbs a basic catalyst by adding an adsorbent and water to a crude polyether obtained by addition-polymerizing an alkylene oxide (C) to an active hydrogen compound (B) in the presence of a basic catalyst (A). In the treatment, a method for purifying polyether is characterized in that magnesium silicate having a sodium content of 0.5% by weight or less is used as an adsorbent.

Basic catalyst (A) used in the present invention
Examples thereof include alkali metal hydroxides (caustic potash, caustic soda, etc.), alkali metal alcoholates (potassium methylate, sodium methylate, etc.), alkali metal simple substances (metal potassium, metal sodium, etc.), and mixtures of two or more thereof. To be Among these, preferred are alkali metal hydroxides and alkali metal alcoholates.

The crude polyether is obtained by subjecting a compound having at least one or more active hydrogen groups to addition polymerization of alkylene oxide in the presence of a basic catalyst, and is used in the method of the present invention (B ), Monohydric alcohols (methanol, butanol, lauryl alcohol, aryl alcohols, etc.), polyhydric alcohols (polyhydric alcohols having 2 to 8 valences such as ethylene glycol, propylene glycol, diethylene glycol, glycerin, trimethylolpropane, pentaerythrium). Amine compounds (polyamines such as ethylenediamine, propylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine and toluenediamine), polyphenols. (Bisphenols, etc.), and the like. Among these, polyhydric alcohols are preferable, and propylene glycol is particularly preferable.
And glycerin.

Examples of the alkylene oxide (C) used in the present invention include ethylene oxide, propylene oxide, butylene oxide and styrene oxide. Of these, preferred is propylene oxide.

A crude polyether obtained by addition-polymerizing an alkylene oxide (C) to an active hydrogen compound (B) in the presence of a basic catalyst (A) is usually a basic substance which is 0 based on the weight of the polyether. It is a liquid containing 0.001 to 1% by weight.

The adsorption aid used in the present invention is magnesium silicate having a sodium content of 0.5% by weight or less. The sodium content is preferably 0.3% by weight or less. If the sodium content exceeds 0.5% by weight, the adsorption capacity is lowered, the adsorption time is prolonged, and a large amount of adsorbent is required.

The purification treatment method of the present invention can be carried out by adding and mixing water and magnesium silicate to crude polyether. As a method for adding it, a method of mixing water and magnesium silicate and then adding it to a crude polyether in a slurry state A method of adding and mixing water and then a method of adding and mixing magnesium silicate After adding and mixing magnesium silicate A method of adding and mixing water can be used. Preferably, of these, it is not necessary to charge the powder directly,
This is a method because it is easy to keep the oxygen concentration low, and oxidative deterioration is restrained.

The amount of water added is usually 0.05 to 5.0% by weight, preferably 0.1 to 5.0% by weight based on the crude polyether.
It is 3.0% by weight. If less than 0.05% by weight,
The tellurium alcoholate cannot be sufficiently hydrolyzed, and the adsorption ability is lowered, or the adsorption time is significantly increased. 5.0% by weight
In the above case, water cannot be dissolved in the polyether and the water is not separated into two layers to lower the adsorption capacity, or the adsorption time is significantly increased.

The treatment temperature is usually 60 to 200 ° C, preferably 80 to 150 ° C. If the temperature is lower than 60 ° C, the adsorption speed is slow and the adsorption time is significantly increased. The mixing time is 5 to 120 minutes, and preferably 10 to 40 minutes, when ordinary stirring is performed.

The method of the present invention is preferably carried out in the absence of oxygen. Specifically, the oxygen concentration in the gas phase is 1000 ppm.
The following, preferably 500ppm or less, 1000p
When it exceeds pm, the polyether is oxidized and colored.

By performing dehydration after the main adsorption treatment, high-purity polyether could be obtained.

[0015]

EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited thereto. The parts in the examples are parts by weight.

Production Example 1 92 parts of glycerin and 12 parts of caustic potash were charged into an autoclave, which was replaced with nitrogen and vacuum dehydrated at 120 ° C. for 60 minutes.
Then, at 100 to 150 ° C., propylene oxide 3,0
50 parts of the mixture was introduced under pressure for about 3 hours, and the reaction was continued at the same temperature until the volatile content became 0.1% or less to obtain liquid crude polyether (hereinafter referred to as crude polyether A). The caustic potash concentration of the crude polyether A was 3,620 ppm.

Example 1 1,000 parts of crude polyether A was placed in a 1.5 liter autoclave, and the atmosphere was replaced with nitrogen to a gas phase oxygen concentration of 45.
Adjust to 0 ppm, add 30 parts of deionized water, and then add magnesium silicate (sodium content 0.2% by weight) to 1
Add 0 part, and replace the nitrogen again to increase the oxygen concentration in the gas phase to 45
0ppm, 60 minutes at 90 ℃, stirring speed 300rp
It was stirred at m. Then, a glass filter- (GF-7
5: manufactured by Toyo Roshi Kaisha, Ltd.) and filtered under nitrogen.
The filtrate has a colorless and transparent appearance and the residual base concentration is 1.1 p.
It was pm.

Example 2 1,000 parts of crude polyether A was placed in a 1.5 liter autoclave, and the atmosphere was replaced with nitrogen to a gas phase oxygen concentration of 45.
Oxygen was adjusted to 0 ppm, and 30 parts of ion-exchanged water and 10 parts of magnesium silicate (sodium content 0.2% by weight) were mixed and deoxidized in another container, and then added to the autoclave to add oxygen in the gas phase. The concentration was measured to confirm 450 ppm, and the mixture was stirred at 90 ° C. for 60 minutes at a stirring speed of 300 rpm. Then
Using a glass filter (GF-75: manufactured by Toyo Roshi Kaisha, Ltd.),
Filtered under nitrogen. The filtrate had a colorless and transparent appearance, and the residual base concentration was 1.2 ppm.

COMPARATIVE EXAMPLE 1 1,000 parts of crude polyether A was placed in a 1.5 liter autoclave, and the atmosphere was replaced with nitrogen to obtain a gas phase oxygen concentration of 45.
Adjust to 0 ppm, add 30 parts of ion-exchanged water, and then add 10 parts of magnesium silicate (sodium content 3% by weight), and replace the nitrogen with oxygen concentration in the gas phase of 450 ppm.
The mixture was stirred at 90 ° C. for 60 minutes at a stirring speed of 300 rpm. Then, filtration was performed under nitrogen using a glass filter (GF-75: manufactured by Toyo Roshi Kaisha, Ltd.). The filtrate had a colorless and transparent appearance, and the residual catalyst concentration was 60 ppm.

Comparative Example 2 1,000 parts of crude polyether A was placed in a 1.5 liter autoclave, and the oxygen concentration in the gas phase was 45 by substituting nitrogen.
Adjust to 0 ppm, add 30 parts of ion-exchanged water, and then add 10 parts of magnesium silicate (sodium content 3% by weight), and replace the nitrogen with oxygen concentration in the gas phase of 450 ppm.
The mixture was stirred at 90 ° C. for 240 minutes at a stirring speed of 300 rpm. Then, filtration was performed under nitrogen using a glass filter (GF-75: manufactured by Toyo Roshi Kaisha, Ltd.). The filtrate had a colorless and transparent appearance, and the residual catalyst concentration was 6 ppm.

Comparative Example 3 1,000 parts of crude polyether A was placed in a 1.5 liter autoclave, and the atmosphere was replaced with nitrogen to a gas phase oxygen concentration of 45.
Adjust to 0 ppm, add 30 parts of ion-exchanged water and then add 15 parts of magnesium silicate (sodium content 3% by weight), and replace the nitrogen with oxygen concentration of 450 ppm in the gas phase.
The mixture was stirred at 90 ° C. for 60 minutes at a stirring speed of 300 rpm. Then, filtration was performed under nitrogen using a glass filter (GF-75: manufactured by Toyo Roshi Kaisha, Ltd.). The filtrate had a colorless and transparent appearance, and the residual catalyst concentration was 4 ppm.

[0022]

According to the present invention, the purification method using magnesium silicate having a low sodium content as an adsorbent significantly reduces the adsorption time as compared with the conventional method. In addition, the amount of magnesium silicate used can be greatly reduced. In addition, magnesium silicate and water are mixed to form a slurry.
Even if it is added to and mixed with the crude polyether in the state, there is no drawback that the processing time becomes long. Further, the polyether obtained by the present invention has a high purity with little oxidative deterioration. Due to the effects as described above, it becomes possible to manufacture a polyurethane foam, a resin, a surfactant, or a grade of polyether that is satisfactory as a raw material for cosmetics, etc. simply, in a short time and with little waste. .

Claims (2)

[Claims] 1. A basic catalyst is obtained by adding an adsorbent and water to a crude polyether obtained by addition-polymerizing an alkylene oxide (C) to an active hydrogen compound (B) in the presence of a basic catalyst (A). A method for purifying polyether, which comprises using magnesium silicate having a sodium content of 0.5% by weight or less as an adsorbent in the adsorption treatment. 2. The amount of water is 0.0 based on the crude polyether.
The method according to claim 1, which is 5 to 5.0% by weight.