JPS61123629A - Removal of heteropolyacid from polyalkylene ether - Google Patents

Abstract

PURPOSE:To adsorb and remove heteropolyacid existing at a small amount in a polyalkylene ether, by treating the polyalkylene ether or a mixture of said compound and an organic solvent with an adsorbent such as activated carbon in the presence of a specific (halogenated) hydrocarbon solvent. CONSTITUTION:A polyalkylene ether or its mixture with an organic solvent is mixed with one or more solvents selected from 3-15C hydrocarbons (e.g. cyclopentane) and 1-15C halogenated hydrocarbons (e.g. chlorocyclohexane), and is treated with one or more adsorbents selected from activated carbon, solid basic compounds (oxide, hydroxide or carbonate of magnesium, calcium or rare earth metal), alumina compounds (e.g. alumina, silica alumina, etc.) and basic ion exchange resins. The heteropolyacid existing in the polyalkylene ether can be removed to a concentration of <=0.0001wt% by this treatment. The product is heated at 100-180 deg.C under reduced pressure to obtain a polyalkylene ether having extremely low impurity content.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for removing heteropolyacids contained in small amounts in polyalkylene ethers.

(Prior art) Polyalkylene ether has been in the spotlight as a raw material for spandex, urethane elastomer, ester elastomer, etc., and its usage has been increasing in recent years.
Various improvements have been made in this production method and seed-seed method. Among them, various polyalkylene ether compounds are synthesized by homopolymerization using epoxy compounds such as ethylene oxide and propylene oxide, cyclic ethers such as tetrahydrofuran, or metals such as diols using a heteropolyacid as a catalyst (Japanese Patent Application Laid-Open No. 58-85028). , Japanese Unexamined Patent Publication No. 59-67255, Patent Application No. 1119-1988 Qat
No. 58-95054, patent application No. 59-5848
No. 5), or partial depolymerization reaction of polyalkylene ether using heteropolyacid (%Gan Sho 58-21511)
No. 2), and further, synthetic reactions of various compounds by reacting these polyalkylene ether compounds with carboxylic acids, etc. are attracting attention.

In such a case, methods for removing the heteropolyacid catalyst from the polyalkylene ether include washing with water, neutralization with a basic substance, etc. !K can be removed, but not more than 0.1% by weight based on the polyalkylene ether.
It is extremely difficult to reduce O and O to less than - by weight. This is due to the fact that the fullylene ether and the heteropolyacid have a strong affinity due to the interaction with the oxygen in the ether, and this small amount of the heteropolyacid is It is considered that it is extremely difficult to separate and remove by this method.

(Problems to be Solved by the Invention) In the conventional method described above, apart from reducing the heteropolyacid to 0.01 weight or less relative to the polyalkylene ether, it is a solid phase, and the polyalkylene ether Even a small amount of such a heteropolyacid in the product can completely deteriorate the quality of the product and cause t7 to have adverse effects such as corrosion of equipment.

(Means for Solving the Problems) Under such circumstances, the inventors of the present invention have spent $P on various methods to effectively remove such a trace amount of remaining heteropolyacid from polyalkylene ether. Then, we arrived at the present invention.

That is, the present invention provides polyalkylene ether with
゛A single solvent selected from hydrocarbons having 3 to 15 carbon atoms or halogenated hydrocarbons having 1 to 15 carbon atoms or a mixture of two or more solvents is allowed to coexist, activated carbon, solid base compound (
(magnesium, calcium, rare earth oxides, hydroxides, carbonates), alumina-containing materials such as alumina or silica-alumina, or basic ion exchange resins.
This is a method for removing a trace amount of heteropolyacid contained in polyalkylene glycol, characterized by adsorption and removal using s or two or more types of adsorbents. Moreover, the present invention
After removing the heteropolyacid by this method, under reduced pressure, 100~
This is a method for purifying polyalkylene ether treated at 180C.

The polyalkylene ether that is the object of the present invention has the general formula: It is a ratio having an alkylene group and is not limited to %. The present inventors first applied for a patent, and then, using polyoxytetramethylene glycol (hereinafter abbreviated as PTMG) obtained from THFi polymerization using a heteropolyacid coordinated with a small amount of water as a catalyst, or THF and Polyether polyol obtained by total copolymerization with alcohol (patent application 1982-
No. 8j081, patent application No. 1983-95056, patent application No. 1973?
-5134a5), and polyether glycols obtained by total copolymerization of 9THF and other cyclic ethers using the same catalyst are preferred mainstream applications.

The organic solvent mixed with the polyalkylene glycol is! ! Examples include, but are not limited to, cyclic ethers which are constituent members of the polyalkylene glycol, polyhydric alcohols, and alcohols commonly used as polymerization end terminators. Next, there is no problem even if water is contained in small amounts.

Examples of hydrocarbons having 3 to 15 carbon atoms or halogenated hydrocarbons having 1 to 15 carbon atoms that should be present in , pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, chloroform, trichlorotrifluoroethane,
Examples include trichlorofluoromethane, benzene, toluene, and chlorobenzene.

The amount of the hydrocarbon or halogenated hydrocarbon to be present is preferably 0.055 times or more by weight, more preferably 0.2 times or more by weight relative to the amount of polyalkylene glycol. When an organic solvent such as THF is mixed, it is preferable to add an amount equal to or more than the amount of the organic solvent. When polyalkylene ether is used alone or when a small amount of organic solvent is heated, the hydrocarbon or halogenated hydrocarbon solvent may phase separate from the polyether phase. Even if you use it, it has little effect. (9) If a suitable amount of the hydrocarbon or halogenated hydrocarbon is mixed in advance as an organic solvent, there is no need to add it, and it may be added if necessary. alkylene ether tx
If a large amount of heteropolyacid is dissolved in the organic solution, a phase mainly composed of heteropolyacid may precipitate. good.

Adsorbents are important, and effective ones are activated carbon, solid basic compounds (oxides, hydroxides, carbonates of magnesium, calcium, rare earths), alumina compounds such as alumina or silica-alumina, or basic ions. It is a replacement resin. Activated carbon is coconut shell based, coal based, petroleum based,
Charcoal-based etc. 4 well! It is not limited to #. The basic ion exchange resin is not particularly limited, but a macroporous type is preferred.

Among these, activated carbon, alumina, and silica alumina have the advantage of having high adsorption capacity and being crushed when packed in an adsorbent t column and processed. %CaO1Ca(OH)1, CaCO
5 may be inexpensive, but MgO has the advantage of less elution. Basic ion exchange resins have the disadvantage that they have a lower adsorption capacity than other adsorbents, need to be used in large quantities, and impurities in the resin are eluted.

The amount of adsorbent used varies depending on the amount of dissolved heteropolyacid, and is used 2 to 5000 times, preferably 10 to 1000 times the weight of the dissolved amount of heteropolyacid. The larger the amount used, the lower the heteropolyacid concentration after treatment.

The heteropolyacid in the present invention is %Mo%W%V,
at least one oxide and other elements, e.g. %P%
It is a general term for oxy acids produced by condensation of oxy acids such as Si, As, Ge, 1% Ti, % Ce, Co, etc., and the atomic ratio of the former to the latter is 2.3 to 12.

Specific examples of these heteropolyacids include phosphomolybdenum g! 2. Phosphotagstic acid, phosphomolybdotungstic acid, phosphomolybdovanadate, phosphomolybdotandustvanadate, phosphorusdustvanadic acid, phosphomolybdoniobic acid, silicotungstic acid, silicomolybdic acid, silicomolybdotungstic acid, keimoly Butotangest vanadate, germanium tungstic acid, borotungstic acid, boromolybdic acid, boromolybdotungstic acid, boromolybdovanadate, borax tandust vanadate, cobalt molybdate, cobalt tungstic acid, arsenic molybdate, arsenic These include tungstic acid, titanium molybdic acid, and sericum molybdic acid.

In contrast, these metal salts also include chloride.

The processing temperature is not limited to IP#, but a temperature that is easy to operate within a temperature range where the processing liquid has an appropriate viscosity is selected. 2a to 150 for copolymerized polyether glycol with ether diol
C, more preferably #i30 to 100C.

The treatment method is to first mix and stir the adsorbent powder with particles, then evaporate to completely separate the adsorbent, or to use conventional methods such as packing the adsorbent in a column and passing the liquid through it. , continuous formula are both applicable. Although the processing time is not particularly limited, it is usually 0.03 to 10 hours, and
Performed in f~3 hours. The used adsorbent can be used again as long as it has adsorption capacity, or after appropriate regeneration treatment.

After the adsorption treatment, the coexisting solvent is removed by distillation under normal pressure or reduced pressure to obtain a polyether with a reduced concentration of heteropolyacid. The 9-polyalkylene glycol treated by this method is less susceptible to deterioration even when heated, and is heated using a thin film molecular distillation apparatus tube at 100 to 1130 C, more preferably 120 to 160 C, under reduced pressure, preferably 3 T.
Since it is possible to perform distillation at less than orr, it is possible to remove not only the solvent but also the linear and cyclic oligomer components contained in the polyalkylene/glycol.

(Effects of the Invention) According to the present invention, the concentration of heteropolyacid in polyalkylene ether can be reduced to ta, ooot weight - or less K. Moreover, elution of impurities from the adsorbent can be suppressed.Finally, by removing the solvent by distillation or the like after the adsorption treatment, a polyalkylene ether with extremely low impurities can be obtained. In addition, trace amounts of heteropolyacids, which are difficult to remove even when adsorbing a mixture of polyalkylene ether and a raw material component such as THF, can be removed by adding the hydrocarbon or halogenated hydrocarbon. Can remove dark spots. After applying the adsorption treatment according to this method, T
By distilling and recovering unreacted upper particles such as HF, scale formation in the distillation column can be suppressed, and furthermore, under reduced pressure,
Even when heated to 0C, deterioration such as depolymerization of the polyalkylene ether is suppressed, and the contained solvent and the like can be substantially completely removed.

This effect is believed to be based on the cooperative action of the hydrocarbon, halogenated hydrocarbon, and the selected adsorbent.

That is, due to the presence of hydrocarbons and halogenated hydrocarbons, the affinity of heteropolyacid for polyalkylene ether is reduced, the adsorption effect of the adsorbent is strengthened, and the elution of the components of the adsorbent itself is suppressed. It is estimated to be. It is also conceivable that salts, hydrocarbons, and halogenated hydrocarbons facilitate the diffusion of heteropolyacids to the adsorbed surface.

Among them, trace analysis of heteropolyacids can be carried out by analyzing W, Mo, etc. using fluorescent X-ray analysis. Very small amount of W remaining in polyalkylene ether after adsorption treatment
However, it is unknown whether Mo maintains the original structure of the heteropolyacid.

(Example) The present invention will be explained below with reference to Examples.

Example 1 Phosphortungstic acid (HlPwl, O, o) is 250p
P-dissolved polyoxyditetramethylene glycol 500
t and THF500P:&H,00,II P 125Of n-octane is added to the solution containing M.

Next, after adding MgO powder, the mixture was stirred for 1 hour at 40C. After that, after removing and collecting the MgO powder with a Teflon membrane filter, THF and n-
Most of the octane was recovered by vacuum distillation, and then 140Cs O,I Torr was recovered using a thin film molecular distillation apparatus.
By distilling off the solvent, water, and linear and cyclic oligomer components contained in polyoxytetramethylene glycol, it is purified to a W content of 0.5 p.
pm to obtain polyoxytetramethylene glycol.

Comparative Example 1 When a liquid having the composition described in Example 1 was treated in the same manner without adding n-octane, the W content was 5avr.
Polyoxytetramethylene glycol which is p is obtained. In addition, the polyoxytetramethylene glycol was partially depolymerized and the recovery rate decreased.Examples 2 to 1S In addition, the polyalkylene ether 100f listed in Table 1 containing the heteropolyacid was added with the hydrocarbon or halogenated carbon dioxide listed in Table 1. After mixing a predetermined amount of hydrogen, adding a predetermined amount of the adsorbent listed in Table 1, stirring at 80C for 1 hour, and recovering with adsorbent t-filtration, and then removing the solvent by distillation under reduced pressure. Then, W
After decreasing the content, polyalkylene ether gold was obtained. The results are shown in Tables 1&C.

Example 14 Phosphortungstic acid (H,FW,,O,,) is 170p
pm dissolved polyoxytetramethylene glycol 50
゜f%THF500f, Hll 00.5f To the liquid composition, n-butane t-1250/ was added, and then activated carbon (Carboy-CAL) was added at 20? It was passed through the packed column at a flow rate of 20 d/hr. Then THF and n
- When hebutane is removed by vacuum distillation, the W content is Ij
A polyoxytetramethylene glycol with a pH reduced to 1 was obtained.

Procedural amendment December 27, 1982

Claims (2)

[Claims] (1) When removing a small amount of heteropolyacid contained in a polyalkylene ether or a mixture of a polyalkylene ether and an organic solvent, a hydrocarbon having 3 to 15 carbon atoms or a halogenated hydrocarbon having 1 to 15 carbon atoms is used. By coexisting a single solvent or a mixture of two or more solvents,
Activated carbon, solid base compounds (magnesium, calcium,
It is characterized by adsorption and removal using one or more adsorbents selected from rare earth oxides, hydroxides, carbonates), alumina compounds such as alumina or silica alumina, or basic ion exchange resins. A method for removing heteropolyacids. (2) When removing a heteropolyacid contained in a small amount in a polyalkylene ether or a mixture of a polyalkylene ether and an organic solvent, a hydrocarbon having 3 to 15 carbon atoms or a halogenated hydrocarbon having 1 to 15 carbon atoms is used. By coexisting a single solvent or a mixture of two or more solvents,
Activated carbon, solid base compounds (magnesium, calcium,
The heteropolyacid was adsorbed and removed using one or more adsorbents selected from rare earth oxides, hydroxides, carbonates), alumina compounds such as alumina or silica alumina, or basic ion exchange resins. After that, under reduced pressure, 10
A method for purifying polyalkylene ether, characterized by processing at 0 to 180°C.