JPH0388824A - Purification of polyethers - Google Patents

Abstract

PURPOSE:To effectively remove a deactivated catalyst and purify a polyether by heat treating the polyether produced by a ring opening reaction of a monoepoxide due to an initiator in the presence of a complex metal cyanide as a complex catalyst and filtrating the reaction mixture. CONSTITUTION:To (A) a polyether produced by a ring opening reaction of >=3C monoepoxide due to an initiator in the presence of a complex metal cyanide as a complex catalyst, (B) 0.5-3wt.% (based on polyether) water is added and heat treatment is carried out preferably at 100-180 deg.C to deactivate the catalyst. The resultant reaction mixture is then treated with (C) a treatment agent consisting of a crystallization agent or an inorganic adsorbent as necessary and filtered to remove the catalyst, thus purifying the polyether.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for purifying polyether.

[Prior Art] Conventionally, polyethers are synthesized using a composite metal cyanide complex as a catalyst, and then this is synthesized with sodium, potassium metal or sodium hydroxide.

The catalyst is deactivated by treatment with potassium hydroxide, etc., and then the polyethers are treated with a mineral acid such as phosphate to precipitate the deactivated catalyst components and the processing agent, which are filtered out from the polyethers. A method has been proposed to
28).

[Problems to be Solved by the Invention] Multimetal cyanide complexes are suitable as catalysts for synthesizing polyols with a small amount of unsaturated monools and have extremely high molecular weights, but after polymerization, there are The presence of the above catalysts catalyzes the reaction of polyether and polyisocyanate during polyurethane production, including the formation of significant amounts of allophanate groups, reducing the physical properties of the polyurethane product. It is necessary to remove it from ethers or completely deactivate it to render it harmless.

The method of deactivating the catalyst with a treating agent such as alkali is one effective method, but since the treating agent catalyzes undesirable reactions during the production of urethane, it is used in various minerals. It had the disadvantage of requiring complicated treatments such as neutralization with acid and repurification.

cMeans for Solving the ProblemsJ The present invention proposes the following invention, which was discovered as a result of various studies, in order to solve the above-mentioned problems. A polyether containing the above-mentioned catalyst obtained by subjecting a monoepoxide having 3 or more carbon atoms to a ring-opening reaction is heat-treated in the presence or absence of water to deactivate the catalyst, and then crystallized as necessary. The present invention provides a method for purifying polyethers, which is characterized in that deactivated catalysts are removed from polyethers by filtration after treatment with a treatment agent consisting of a catalyst or an inorganic adsorbent.

As a method for purifying polyethers containing a composite metal cyanide complex, the polyether containing the catalyst is heat-treated in an amount of water and under temperature conditions sufficient to deactivate the catalyst to obtain a composite metal cyanide complex. Decomposes into ionic species and becomes harmless.

The amount of water added varies depending on the amount of composite metal cyanide catalyst used and the type of polyether, but is usually 0.
It may be selected as appropriate from the range of 2 to 10 wt%, for example, a triol with a molecular weight of 10.000 and a catalyst addition amount of 500.
ppm/polyether, the amount of water used for treatment is 0.5-3 wt%/polyether, preferably 1-2
wt% is appropriate. If the amount of water is small, it will take a long time to detoxify the catalyst components, and if the amount of water is large, the viscosity of the liquid system containing polyether will increase and the detoxification reaction of the catalyst by water will be inhibited. Undesirable.

The treatment temperature range varies slightly depending on the type of polyether containing the catalyst to be treated, presence or absence of water addition, etc., but is usually 100
It may be selected appropriately from the range of ~180°C, for example, molecular weight 1
0.000 polyether and water addition system: 120-1
A suitable temperature is 70°C, preferably 130-150°C, and in a hydrothermal addition system, the temperature is preferably maintained at 150-180°C. If the temperature is below the above range, the deactivation of the multimetal cyanide complex catalyst will not proceed sufficiently, and if the temperature is above 180° C., part of the decomposition of the polyether will proceed, which is not preferable.

The processing time depends on the amount of compound metal cyanide complex used,
Although it varies depending on the type of polyol, etc., the time may be appropriately selected from the range of 1 to 6 hours, preferably 2 to 4 hours.

The catalyst is deactivated by the above treatment, and after dehydration treatment, it is possible to directly use these polyethers and polyisocyanate to synthesize a urethane compound, but the deactivated catalyst residue suspended in the polyether In order to remove it from the polyethers, it is preferable to treat it with a treatment agent consisting of a crystallizing agent or an inorganic adsorbent and filter it from the polyethers.

When using a crystallizer as a treatment agent, it is suitable to use a mineral acid with a dissociation constant of 10'' or more in an aqueous solution at 25°C, and mineral acids such as Na, Ba, K, Ca, A1, etc.
It may be selected as appropriate from sulfates, phosphates, etc. consisting of one or more species. When using an inorganic adsorbent as a treatment agent, for example, LizCO□NamayuzushiCOi, MgCO5,
Oxides or hydroxides of Group I, Group ■, Group ■ such as CaCO5, synthetic aluminum silicate, synthetic silicic acid represented by 2.5Mg0・A1□03・xH,O (Kijiward 300. Kyowa Chemicals), etc. One or more of magnesium, activated clay, acid clay, or a mixture thereof may be used as appropriate, and polyethers containing deactivated multimetal cyanide complexes may also be treated with the above-mentioned treating agent before dehydration treatment. After stirring for 1 to 2 hours at a temperature of 90 to 150°C, preferably 100 to 120°C, the degassed under reduced pressure at the above temperature conditions to coprecipitate the deactivated catalyst with the crystallizer. Remove it by letting it dry or by treating it with an adsorbent.

Through the above series of treatments, it is possible to provide purified polyethers suitable for urethane reactions.

[Examples] The present invention will be specifically explained below using Examples and Comparative Examples, but the present invention is not limited only to these Examples.

(Example 1) Multimetal cyanide complex synthesized from zinc chloride and alkali metal cyanocopaltate (Zn60, Co30
2 wt% of water was added to a polyoxypropylene triol with a molecular weight of 5,000 synthesized using (ppm) and mixed at a temperature of 150°C for 3 hours. Next, the mixture was degassed under reduced pressure at a temperature of 120° C. and a pressure of 10 Torr to remove coexisting moisture, thereby obtaining a polyether in which a small amount of the deactivated catalyst component was suspended. The results of examining the reactivity of this polyether with P-MDI are shown in FIG. 1, and it was confirmed that reaction behavior equivalent to that of polyether containing no catalyst was obtained.

(Example 2) 0.8 wt% Na5HP107 was added to the polyether containing the deactivated catalyst treated in Example 1.
l wt% synthetic magnesium silicate (KW-600S
, Kyowa Kagaku) and mixed for 0.5 hours under a temperature condition of 120''C(7), and then degassed under reduced pressure under a pressure of 10 Torr under the above temperature condition.

Next, the deactivated catalyst and processing agent were separated from the polyether using N15C filter paper, and as a result, approximately 92% of Zn and Go could be removed from the polyether. It was confirmed that this polyether was transparent and showed normal reaction with isocyanate.

(Example 3) After heat treating the same polyether as in Example 1 at a temperature of 170'C for 3 hours, synthetic magnesium silicate (KW-6
0O3, Kyowa Kagaku) to polyether at 1.5wt.
% was added and treated under reduced pressure at a temperature of 120'C for about 1 hour. Then, the deactivated catalyst and processing agent were separated from the polyether using a &5C filter paper, and as a result, Zn and G were extracted from the polyether.

About 80% of the amount was removed, and the reactivity with P-MDI was also normal.

[Effects of the Invention] The present invention provides polyethers obtained by ring-opening a monoepoxide having 3 or more carbon atoms as an initiator using a multimetal cyanide complex as a catalyst under specified temperature conditions. We propose a simple purification method in which the catalyst in the polyether is deactivated by heat treatment.

In the conventional method of using an alkali such as KOH as a decomposing agent, the decomposing agent acts as a catalyst for harmful reactions in the next urethane process, so refining treatment is required to remove this alkaline component again. This was a factor in increasing costs.

In essence, the above-mentioned catalyst is deactivated and rendered harmless only by heat treatment, making it possible to provide purified polyether at a lower cost.

[Brief explanation of drawings]

FIG. 1 is a graph showing the reactivity of the polyether polyol obtained according to the present invention. Taku! Figure 1 Seidan Tf1 Kai (HIS)

Claims (2)

[Claims] (1) Polyethers containing the above catalyst obtained by ring-opening a monoepoxide having 3 or more carbon atoms as an initiator in the presence of a multimetal cyanide complex catalyst in the presence or absence of water. The deactivated catalyst is removed from the polyether by heat treatment to deactivate the catalyst, and then optionally treated with a treatment agent consisting of a crystallizer or an inorganic adsorbent, followed by filtration. A method for purifying polyethers. (2) The method according to claim 1, characterized in that the treatment temperature is 100 to 180°C.