JPS6034965B2 - Purification method of polyether polyol - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for purifying polyether polyol (hereinafter referred to as polyether).

Conventionally, polyethers are obtained by addition polymerizing an alkylene oxide to an organic compound having at least one active hydrogen group in the molecule in the presence of an alkaline catalyst.

Examples of alkaline catalysts used in this reaction include caustic potash, caustic soda, sodium methylate, potassium methylate, metallic potassium, potassium carbonate, and sodium carbonate. If these alkaline catalysts or their neutralized salts remain in the polyether, they can be used in all uses of the polyether, such as raw materials for polyurethane resins, raw materials for brake fluids, raw materials for A8 products, raw materials for activators, and raw materials for synthetic lubricating oils. Since it has a negative effect on the environment, it is usually removed. Conventional purification methods for removing alkaline catalysts or their neutralized salts from polyethers containing alkaline catalysts include the following. ... A method for neutralizing an alkaline catalyst with an acid and removing the resulting salt by sieving, as disclosed in Japanese Patent Publication No. 37-15597, Japanese Patent Publication No. 41-21237, and Japanese Patent Publication No. 47-13745.
-26158, Special Publication No. 13021, Special Publication No. 42-13021, Special Publication No. 42-13021, Special Publication No. 13021
No. 5-32432, Special Publication No. 45-331, Special Publication No. 5
2-10018 and Hakama Kosho No. 53-123499, etc., there is a method of using an alkali adsorbent without neutralization. 36-22148 and Samurai Publication No. 51-23211 using an ion exchange resin Method N of Japanese Patent Publication No. 52-3300 in which an alkaline catalyst is neutralized with carbon dioxide gas and the resulting carbonate is passed through A method of neutralizing with phosphoric acid and filtration with phosphoric acid, and removing the sulfur solution with magnesium silicate, aluminum oxide, magnesium oxide, aluminum hydroxide, aluminum carbonate, or a mixture thereof, as disclosed in Tsubaki Publication No. 51-101098. All of these methods have major drawbacks, and improvements are desired.

In other words, in 'a), the particles of the salt produced are fine and unstable, making it extremely difficult to sieve, and being sensitive to fluctuations in pressure, resulting in large variations in quality and cloudiness. Easy to occur.

In addition, halogen-based acids extremely corrode stainless steel, which places extreme restrictions on the material of the equipment, and heavy metal ions are emitted from the equipment, impeding the use of polyenal.

[Although this method is relatively preferable in terms of low performance, these adsorbents do not have sufficient alkali adsorption ability, so they have to be used in large quantities in powder form, and it takes a very long time to complete adsorption. do.

Furthermore, the quality of the haze liquid deteriorates as the transit time passes and the sarugosho rises. However, even if electrostatic coalescence is used to promote the purification effect, the purification effect is insufficient, and problems arise with the remaining amount of potassium + sodium, odor, hue, pH value, etc.

In the case of 0, the ion exchange rate is very slow, and the organic impurities contained in the ion exchange≠sword resin are eluted into the polyether, deteriorating the hue, odor, etc., and the residual amount of potassium + sodium is large.

The target is that the particle strength of the alkali metal carbonate produced by carbon dioxide gas neutralization is weak, so it is destroyed by the Kashiei pressure.
It easily passes through the staghorn membrane, resulting in an increase in the potassium decasodium content of the polyether and occasional turbidity.

Furthermore, the polyether obtained by this method tends to have a high acid value, which is particularly problematic as a raw material for polyurethane resin.

M is the same as the method [A] until phosphoric acid neutralization and filtration, and is a well-known fact.The feature of the invention is rather that it lowers the remaining acid value, and the concept and effect of the purification method. Judging from this, it does not exceed the method of (I).

The present inventors have conducted extensive research to improve the above-mentioned drawbacks, and as a result, have arrived at the present invention.

That is, a polyether polyol containing an alkaline catalyst synthesized in the presence of an alkaline catalyst has a dissociation constant (first dissociation constant in an aqueous solution of 260, hereinafter the same) of 10-3 or more in the presence or absence of water. A polyether polyol purification method that involves neutralizing with an acid or an aqueous solution thereof, dehydration, and then sieving. (1) A key acid (with a dissociation constant of 10- (3 or more) salts or their aqueous solutions, (0)
This is a polyether polyol purification method characterized by adding an acid adsorbent or an alkali adsorbent as an adsorbent in a step after neutralization and before dehydration.

The bolyether applicable to the present invention is obtained by addition polymerizing an alkylene oxide to an organic compound having at least one active hydrogen group in the molecule in the presence of an alkaline catalyst. Examples of organic compounds having at least one active hydrogen group in the molecule used as raw materials for polyether include monohydric alcohols such as methanol, ethanol, butanol, octanol, lauryl alcohol, ethylene glycol, propylene glycol,
4. Dihydric alcohols such as butanediol, alcohols such as glycerin, trimethylolpropane, bentaerythritate, sorbitol, methane, amine compounds such as aniline, ammonia, ethylenediamine, jethylenetriamine, toluenediamine, etc. . Further, the alkylene oxide includes, for example, ethylene oxide, propylene oxide, butylene oxide, styrene oxide, and the like.

The polyether obtained by addition polymerization in this manner is usually a viscous liquid containing 0.1 to 1% by weight of an alkaline catalyst. Next, the purification method of the present invention will be described. In the purification of the present invention, polyether containing an alkaline catalyst is
The dissociation constant of excess equivalents in the presence or absence of water is 10-
Neutralization with three or more key acids or their aqueous solutions.

When neutralization is carried out in the presence of water, up to 1% by weight, preferably from 0.5 to 2% by weight of water is added to the polyether containing the alkaline catalyst.

Neutralization is performed at a temperature of 30 to 100 oo so that the multiplier value is near neutral.

Scale acids or their aqueous solutions with a dissociation constant of 10-3 or more used for neutralization are, for example, ratios S04, HC1, HN03, H
CIQ, NQS03, QS203, Sun2P02, Mountain P
207, HCI03, HI03, Sun 3P04, Sun 3P0
3, Technique S03, Day 2NS03, and their aqueous solutions.

Boric acid has a low dissociation constant, and mineral acids and organic acids have weak bonds between crystalline salt particles, so they are extremely susceptible to fluctuations in overpressure.
In the purification method of the present invention, complete filtration is difficult.

Next, the crystallizer used in any step before dehydration is a mineral acid salt (dissociation constant of 10-3 or more), such as Na
3, Na Yu03・740, K3P03, N
a2HP04・12th 20, NaH2P04・day 20,
CaHP04/2 L○, AIP04, K3P04, M
gS04, M-cross 04・&○, M-book 04・7board 0, K2M
g(S04)2・Thin 20, Na2S〇4, Na2S〇4
・1 day 20, CaS 04, CaS 04 ・2 day 20, N
aA1 (S04) 1 offense 20, KA1 (S04) 2 1
2 L0, AI2 (S04) 3, ZnS04・7th 20
, NaIQ, Na2S203・9day20, Na4P20
7, CaC12, CaC12/mother L0, AIC13, A
IC13, bait 20, etc.

These crystal forming agents promote the growth of salt crystals produced by neutralizing the catalyst. These crystallizers may be added in the form of powder, granules, crystals, or aqueous solution, and the amount added is arbitrary, preferably 1.
% by weight or less, more preferably 0.01-0. Box weight%.

The crystallizer may be added at any step before dehydration. For example, after obtaining a polyether containing an alkaline catalyst, (a) add a crystallizer and then add water; b} water and the crystallizer at the same time; or add the crystallizer as an aqueous solution; { c-If a mineral acid with a dissociation constant of 10-3 or more and a crystallizer are added at the same time, the crystallizer is added as a mixed aqueous solution of the stannic acid,'d} In the presence of water, the crystallizer has a dissociation constant of 10.
-After neutralizing with mineral acid of 3 or more, add crystallizing agent,'
e} After neutralization, a crystal forming agent is added as an adsorbent at the same time as the adsorbent, 'n A crystal forming agent is added after the adsorbent is added, etc.

Next, the adsorbent used in the process after neutralization and before dehydration is an acid adsorbent if the pH value of the neutralized polyether containing an alkaline catalyst is acidic, and an alkaline adsorbent if it is alkaline. Use.

Acid adsorbents include, for example, Li2C03, Na2C03, M
Group 1, D and M oxides or hydroxides such as gC03 and CaC03, 2.5Mg0・AI203・
Composite salts of Group 0 and Group M compounds such as XQ0 (Kyoward 300. manufactured by Kyowa Chemical Industry, hereinafter the same), Mg6N2(OH), 6C03/Bait 20, citrate salts such as synthetic magnesium frogate, synthetic aluminum citrate, etc. or a mixture thereof. Examples of the alkaline adsorbent include synthetic magnesium citrate, synthetic aluminum formate, activated white clay, acid clay, and mixtures thereof.

The timing of addition of these adsorbents is after neutralization and before dehydration, and the amount added is 2% by weight or less, preferably 0.05 to 0.5% by weight, based on the polyether containing the alkaline catalyst.

Also, the pH of the neutralized polyether containing an alkaline catalyst
If the value shows 7.0, those adsorbents may not be used. Next, dehydration should be 80 o'clock or more, preferably 100 to 14
The reaction is carried out at 0°C and under reduced pressure.

Next, pass. The purified polyether obtained according to the purification method of the present invention fully satisfies the specifications required for all applications, such as the following specifications required for one-shot polyurethane foam applications.

Appearance: Transparent liquid, *no turbidity or mist* *Hue (APHA = American Public Health Act) Moisture content: 20 or less
0.05% by weight or less ※※※ Potassium + Sodium 5p
pm or less ※※※※PH 6.5 to 7.5 Odor Virtually absent Note * Turbidity, presence or absence of suspended matter and suspended particles in the kasumi polyether, pillow state.

※※Hue Hazen No. By law.

※※※ Potassium + Sodium By atomic absorption spectrometry.

※※※※PH Isopropanol:water (10:6 volume) Quantity ratio) 10 samples per 100 cc of solution Melt and measure.

Among the above items, 1.0pp for potassium + sodium
It must be less than m.

If the polyether does not meet these standards, one-shot polyurethane foam may cause cracking, shrinkage, or discoloration of the foam, and polyurethane prepolymers may cause abnormal solidification or abnormal pot life.

Examples are shown below.

In the examples, "%" and "part" are based on weight. Example 1 Add 7.5 hours of caustic potash (85%) to 92 hours of glycerin, then add 2500 hours of propylene oxide at a reaction temperature of 1 hour.
At 30:00, ethylene oxide was introduced at a reaction pressure of 10 k9/g of carp, and 500 g of ethylene oxide was added at a reaction temperature of 120°C and a reaction pressure of 3.
K9/DuG was introduced to produce polyether.

Next, 30 hours of water was added and mixed uniformly, and then 9 hours of a 62% sulfuric acid aqueous solution was added at 90 quarts, and the mixture was neutralized by lighting. The pH value of the neutralized polyether was 6.4.

Next, 30% of aluminum sulfate was added as a crystallizing agent, and 15% of synthetic magnesium citrate was added as an acid adsorbent, and the mixture was incubated. Next, it was dehydrated at 120 oo and below 10 Hg, and filtered through a glass filter using frog algae as a filtering aid.
The oak liquid showed the following analysis values and was found to have good quality as a polyether for polyurethane resins.

Analysis item Analysis value acid value (9KOH/evening) 0.0
07 Moisture (%) 0.01
6 Sodium (ppm) 0.0
5 Potassium (ppm) 0.1
0pH
7.0 Hydroxyl number (9KOH)
56.8 Appearance Colorless Transparent Body Example 2 Polyether was produced under exactly the same conditions as in Example 1.

Next, at 80oC, 18.5 hours of a 30% aqueous phosphoric acid solution was added to neutralize the mixture. The pH value of neutralized polyether is 7
．． It was 6. Next, 30 minutes of synthetic aluminum citrate was added as an alkali adsorbent, and after stirring for 120 minutes, magnesium sulfate (7 hydrate) was added as a crystallizing agent.
The mixture was dehydrated for 120 minutes at 20q0, 1 mmHg or less, and filtered through a glass filter using Keishi as a filter aid.

The oak liquid showed the following analytical values, and was found to have good quality as a polyether for polyurethane resin. Analysis items
Analysis value Fuji value (female KOH/evening) 0.00
5 Moisture (%) 0.014
Sodium (ppm) 0.0 Potassium (ppm) 0.10P
H
7.0 hydroxyl number (9KOH/evening)
567 Appearance Colorless transparent liquid Example 3 The following three polyethers were synthesized in the presence of an alkali catalyst.

Polyether A: 200 Glycerin 4.8K9 and Caustic Potassium (85%) 85 in its stainless steel autoclave
After charging 0.0 yen and purging with nitrogen, propylene oxide 145.2k9 was introduced at 12500, 6k9/Chu G,
Once the reaction is completed, ethylene oxide 30
K9 was introduced at 115° C. and 2k9′ base G and reacted.

Polyether B: 200% to the autoclape circle
Syrup syrup 50k9, ethylene glycol 5k9, ethylenediamine 10k9 and caustic soda (
48%) 375 yen was prepared, heated after replacing with nitrogen, and heated to 105 yen.
qC, 50k9 of propylene oxide was introduced at 2k9'G, the reaction was completed, water was distilled off at 125qC, and then 65ko of propylene oxide was introduced at 1
The reaction was completed by introducing 25q0 and 2k9/G.
Polyether C: 200% in its autoclave
Prepared sorbitol 6k9, dipropylene glycol 6k9 and caustic potash (48%) 800mg, 125q0
After removing the water at a temperature of 1 kg Hg or less, propylene oxide 180k9 was introduced at 125°C, 5k9/g, and then ethylene oxide 6k9 was added at 115℃, 2kg'
The reaction was completed by introducing at ○. When these various polyethers obtained were purified according to the method of the present invention,
It became as shown in Table 2. Note that an ultra filter (manufactured by Miura Chemical Industry Co., Ltd.) was used for the moat filtration. Calligraphy 83 Satoshibe.

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<l))) World Example 4 Under the conditions of Example 3, sampling was carried out over time during the sieve filtration, and fluctuations in the analytical values of potassium and sodium of the polyether that had passed through the sieve membrane were investigated.

As shown in Table 2, all the samples ranging from Sarukashi crab to iris showed high quality analytical values, demonstrating the features of the present invention. Table 2 Comparative Example 1 A polyether was synthesized in exactly the same manner as in Example 1.

This polyether was neutralized by adding 37.1 hours of a 30% aqueous phosphoric acid solution at 9000°C.

The pH of the neutralized polyether was 5.6.

Next, add acid adsorbent 2.8Mg○・AI203・XH20 to 1
5 ta was added and treated at 90°C for 2 hours. Next 12
After removing the water at 0° C. and below 10 Hg, the mixture was filtered through a glass filter using Keishinoshi as a filtering agent.

The oak liquor had white fine particles suspended in it and had a strong aldehyde odor. Analysis item Analysis value Moisture (%) 0.014 Acid value (Female KOH/Evening) 0.21P
H
6.0 Sodium (ppm)
0.10 potassium (ppm) 1
42 hydroxyl number (m9KOH/even) 5
7.1 Appearance White Suspension Liquid Comparative Example 2 A polyether was synthesized in exactly the same manner as in Example 1.

An attempt was made to purify this polyether using the following procedure.

{1} Neutralize the polyether by adding 37.1 parts of a 30% aqueous solution of phosphoric acid at 90 oz, then 120 q
After removing the water at a temperature of 1 mmHg or less, it was filtered using celiac earth as a filter aid.

The analytical values of the purified polyether were as shown in Table 3.

(3) Synthesis of Bolyether 31 minutes of magnesium citrate and 60 hours of water were added, and then heated at 120 degrees for 1 hour, dehydrated, and treated with citrate as a filter aid. The analytical values of the purified polyether were as shown in Table 3.

2000 ml of normal hexane was added to the polyether to dissolve it. Next, 2,000 g of water was added and mixed for a while, but the mixture remained in an emulsified state and showed no signs of separation even after 2 hours. After adding 6 volumes of water to '4' polyether and stirring it evenly, the mixture was neutralized by blowing 8.5 volumes of carbon dioxide gas at 5500°C, resulting in a pH of 6.7 and a cloudy appearance.

Next, while maintaining the same temperature, nitrogen gas was bubbled at a rate of 80°/min for 30 minutes.

This was taken out, dehydrated under reduced pressure at 110:00 for 30 minutes, and then filtered through a ditch using cinnabarium as a thinning aid. The analytical values of the purified polyether were as shown in Table 3.

5) Add 150 liters of polyether water, fill it with 300' of cation exchange resin (Mitsubishi Kasei Corporation {Isei Ion SKIB) which has been regenerated into H-type, and put it into a heat-insulating tube with an inner diameter of 35 mm (heated to 80%). Pass it in a downward flow at a space velocity of 12.5, then in a rotary evaporator at 120qo, IQ
Dehydrated below the ship's Hg. The obtained purified polyether showed the analytical values shown in Table 3.

Table 3 Analytical Values of Comparative Polyether All of the polyethers were of poor quality as polyethers for polyurethane resins, but method [4] was relatively good.

Comparative Example 3 Polyether A, polyether B and polyether CC were synthesized in the same manner as in Example 3.

For these polyethers, a scale-up test was conducted using method (2), which had relatively good results in Comparative Example 2. That is, in a 200 qo stainless steel autoclave, 2% water was added to polyether and mixed uniformly, then a predetermined amount of carbon dioxide gas was blown in at 60 qo to neutralize it, and then the mixture was heated with nitrogen gas for 50 minutes. Bubbling was carried out for 30 minutes at a rate of 30 minutes.

Next, the topping was dehydrated at 110° C. for 30 minutes, and filtered using an ultra filter (manufactured by Miura Chemical Industries) using Katsurabu soil as a filter aid. When samples were taken at regular intervals from the start of the transition, as shown in Table 4, it was found that there were extremely large variations in quality.

Table 4

Claims (1)

[Claims] 1 A polyether polyol containing an alkaline catalyst synthesized in the presence of an alkaline catalyst has a dissociation constant (first dissociation constant in an aqueous solution at 25°C, the same hereinafter) of 10^-^3 or more in the presence or absence of water. (I) Mineral acid (dissociation constant 10^- ＾3 or more) or their aqueous solutions, (I
I) A method for purifying polyether polyol, which is characterized by adding an acid adsorbent or an alkali adsorbent as an adsorbent in a step after neutralization and before dehydration.