JPS5858364B2 - Method for producing polyether compounds - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a polyether compound by adding a plurality of alkylene oxides to a compound containing active hydrogen. The present invention relates to a method for producing polyether compounds using a novel catalyst system.

Polyurethanes are widely used in foams, elastomers, and other applications.

Polyurethanes are usually obtained by reacting an incyanate compound having at least two isocyanate groups with an active hydrogen compound having at least two active hydrogens.

The most widely used active hydrogen compound is polyether polyol.

Polyether polyols are produced by adding alkylene oxide to an active hydrogen-containing compound having at least two active hydrogens, such as a polyhydric alcohol or amine, as an initiator.

As the alkylene oxide, propylene oxide alone or a combination of propylene oxide and ethylene oxide is often used, and butylene oxide may also be used alone or in combination.

The reaction between the initiator and the alkylene oxide is usually carried out in the presence of a catalyst such as potassium hydroxide.

Polyether polyols used as raw materials for polyurethane have other quality requirements such as residual catalyst amount, water content, acid value, and one of them is the degree of unsaturation.

The degree of unsaturation refers to the amount of unsaturated double bonds in the polyether polyol.

Polyether polyols with a high degree of unsaturation tend to cause discoloration and off-odor of products, and also have an adverse effect on the physical properties and quality of polyurethane, so polyether polyols with a low degree of unsaturation are desired.

Note that the measurement of the degree of unsaturation of polyether polyols is specified in JIS K1557, and the amount is expressed in milliequivalents/gram (ineg/g).

The degree of unsaturation in polyether polyols is most problematic when propylene oxide is used as the alkylene oxide.

That is, it is thought that the cause of the generation of unsaturated groups is due to the abstraction of hydrogen from propylene oxide.

That is, −1[) M −+−CH−CH−a(−+ROH+CH2
=C))-CH20M+2 \.

It is thought that the unsaturated group is generated by the reaction represented by /(RO: ion in inishekhu or polyneedle, M: metal ion).

It is known that the degree of unsaturation increases relative to the reaction temperature, pressure, and amount of catalyst, and is also proportional to the amount of propylene oxide added.

Further, as a catalyst, potassium hydroxide generates fewer unsaturated groups than sodium hydroxide.

Therefore, the reaction of adding propylene oxide to an initiator has conventionally been carried out under relatively miscible conditions using potassium hydroxide as a catalyst.

In addition, the crude polyether polyol obtained by the reaction was purified by neutralization, water washing, adsorbent treatment, solvent treatment, and other methods to obtain a polyether polyol with a low degree of unsaturation.

However, when using the reaction of alkylene oxide under miscible conditions, no improvement in the productivity of polyether polyols can be expected.

Increasing the temperature and pressure and increasing the amount of catalyst improves productivity, but as mentioned above, the degree of unsaturation increases, quality deteriorates, and purification becomes complicated.

Therefore, the present inventor conducted research and examination to find catalysts effective for alkylene oxide addition reactions, such as catalysts that improve the reaction rate without increasing the degree of unsaturation and catalysts that can reduce the degree of unsaturation.

As a result, it was discovered that by using a combination of an alkali metal compound and a phase transfer catalyst as a catalyst, the reaction rate could be increased and alkylene oxide could be added without increasing the degree of unsaturation.

This catalyst system can improve the reaction rate, so
It is also effective in addition reactions of alkylene oxides other than propylene oxide, which causes unsaturated groups.

In addition, polyether compounds obtained by adding alkylene oxide to an initiator are not limited to polyether polyols, which are raw materials for polyurethane, but can also be used as surfactants, lubricants, and other various uses or as raw materials for them. Therefore, it is considered that the present invention is also effective for producing polyether compounds used for these purposes.

The present invention relates to a method for producing these polyether compounds, that is, in a method for producing polyether compounds by adding alkylene oxide to an active hydrogen-containing compound, an alkali catalyst comprising an alkali metal compound and a phase transfer catalyst are used as catalysts. This is a method for producing a polyether compound characterized by using a combination of.

The catalyst in the present invention not only accelerates the addition reaction of alkylene oxide, but also reduces the degree of unsaturation of the polyether compound when the alkylene oxide is propylene oxide.

The reason why this catalyst reduces the degree of unsaturation is not clear, but it is presumed that this catalyst promotes the addition reaction of propylene oxide but does not promote the unsaturated group forming reaction.

As the alkali catalyst made of an alkali metal compound, well-known ones can be used.

Examples include hydroxides and carbonates of potassium and sodium, with hydroxides being particularly preferred.

A particularly preferred alkaline catalyst is caustic potash.

As the phase transfer catalyst, quaternary ammonium salts and quaternary phosphonium salts are suitable.

Particularly preferred is a phase transfer catalyst consisting of a quaternary ammonium salt.

These catalysts are usually compounds containing a hydrophobic group such as an alkyl group or an aryl group and a hydrophilic group such as a quaternary ammonium salt or a quaternary phosphonium salt moiety.

In general formula, R4A+X (R: same or different monovalent hydrocarbon group, A+: 100-0 N or PX, halogen, OH, I (SO4゜(JO
It is a compound represented by a monovalent anion such as 4).

Especially preferred as R are an alkyl group, an aryl group, and an arylalkylene group.

Examples of specific compounds include the following.

(CH3(CH2)3)4 N+Cl'□, CCH3
(CH3)3)40-NBr, (CH3(CH2)3)4N+(H
8O,l)-(raH17)3CH3N+Cd, (C
4H0)4NO1'.

(CI2 H25) (CH3)3 N+ci, (
C3H7,)+N”CJ?(n-c16)(33)(C
4H9)3N+cg, (C2H5)3(C5H5C
H2) N+CIJ-2(CHs (CH2)3)4”
"Ko(n-Cl6 H33) (C4H9)aP+Br
The amount of phase transfer catalyst used is not particularly limited.

However, it is usually preferable to use 1 mole or more, particularly 10 to 100 moles, based on the alkali metal compound.

The active hydrogen-containing compound, ie, the initiator, is a compound having a hydrogen-containing group to which an alkylene oxide can be added, and typical hydrogen-containing groups are a hydroxyl group and an amino group.

In order to produce polyether polyol, which is the raw material for polyurethane, the initiator requires at least two active hydrogens.

Therefore, polyhydric alcohols and amines are suitable as initiators.

Compounds having two or more phenolic hydroxyl groups such as polyhydric phenol are also used.

In addition, polyether monools may be used as surfactants, lubricants, and other uses other than polyurethane, and in such cases, monohydric alcohols are mainly used as the initiator.

Examples of polyhydric alcohols include dihydric alcohols such as ethylene glycol and propylene glycol, trihydric alcohols such as glycerin, hexanetriol, and trimethylolpropane, pentaerythritol, sorbitol, and other polyhydric alcohols with a valence of 4 or more. .

Further, amines such as ethylenediamine and aniline, hydroxyl group-containing phosphorus compounds, and polyhydric phenols such as bisphenol A are suitable as initiators for polyether polyols as raw materials for polyurethane.

Polyether polyols are also used as incubators of higher molecular weight polyether polyols.

In this case, it is suitable for producing a polyether polyol having a relatively low hydroxyl value.

The alkylene oxide is preferably an alkylene oxide having 2 to 4 carbon atoms, such as ethylene oxide, propylene oxide, butylene oxide, or epichlorohydrin, but is not limited to these, and may be an alkylene oxide having 5 or more carbon atoms.

Particularly preferred are alkylene oxides containing propylene oxide that produce unsaturated groups.

That is, the present invention is applicable to the production of polyether compounds containing at least oxyalkylene groups, such as when propylene oxide is added alone, a mixture of propylene oxide and other alkylene oxides, or when propylene oxide and other alkylene oxides are sequentially added. Preferably used.

As the other alkylene oxide to be combined with propylene oxide, ethylene oxide is most preferred.

A polyether compound is an active hydrogen-containing compound, that is, a compound in which two or more molecules of alkylene oxide are added to one molecule of Onishake, especially +OR'+n (R'
: alkylene group, n: an integer of 2 or more).

Furthermore, the polyether compound is preferably a polyether polyol that can be used as a raw material for polyurethane.

In particular, conventional polyether polyols had a high degree of unsaturation.

It is preferable to apply the present invention to the production of polyether polyols with a high addition amount of propylene oxide.

This high molecular weight polyether polyol has a hydroxyl value of 1
It is a polyether polyol having a molecular weight of 5 to 200, and is mainly used as a raw material for soft, highly elastic polyurethane foams and polyurethane elastomers.

Preferably, the reaction is carried out under conventional conditions, but
It is not limited to that.

For example, the alkali metal compound catalyst is usually used in an amount of 1 to 30% more by weight than the active hydrogen-containing compound, and the alkylene oxide is added at a humidity of 80 to 180° C. under normal pressure or increased pressure.

In the present invention, these conditions can of course be used as they are, but the reaction can also be carried out under more miscible conditions or more aggressive conditions.

Although the present invention will be specifically explained above using Examples and Comparative Examples, the present invention is not limited only to these Examples.

Example 1 After mixing 750 g of propylene oxide added to glycerin with a molecular weight of 1500 using caustic potash as a catalyst and 19.5 g of caustic IJ, 17.3 g of tetrabutylammonium chloride was simultaneously charged into an autoclave and heated to 110°C. The temperature rose to .

After removing moisture from the catalyst under reduced pressure, 3180 g of propylene oxide were introduced over a period of 5.5 hours.

The reaction proceeded while the autoclave internal pressure was maintained at 2.8 ky/cat G.

Thereafter, aging was performed at 110°C for 2 hours.

After the reaction was completed, 172 g of magnesium silicate was added, 11
The catalyst was adsorbed by stirring at 0° C. for 3.5 hours, filtered and dried to obtain a polyol.

The OH value of the obtained product is 29.8, which is unsaturated rice (meq.
/g) was 0.046.

Measurement Comparative Example-1 Based on US JIS K-1557-1970 Propylene oxide was added to glycerin to obtain a molecular weight of 1
What was 500 was 750! ! and caustic potash 19.5. P was placed in an autoclave, and propylene oxide was introduced in the same manner as in Example 1.

5. To introduce 3180 g of propylene oxide.
It took 5 hours.

Is the autoclave internal pressure 4 or 8 ky/a? The reaction proceeded while being maintained at tG.

Thereafter, thermal formation was performed at 110° C. for 3.5 hours for further purification.

The OH value of the obtained product is 3o.8, and the degree of unsaturation is 0.1.
It was 88 meq/g.

Compared to Example-1, although the same propylene oxide introduction rate was adopted, the autoclave internal pressure was higher, and the reaction rate was correspondingly slower, which seems to be due to the accumulation of propylene oxide monomers.

Furthermore, the degree of unsaturation of polyether polyol is high, which means that chain transfer reactions with propylene oxide monomers occur frequently.

Examples 2 to 9 Polyether polyols were synthesized in the same manner as in Example 1 by changing the type of phase transfer catalyst.

The amount of phase transfer catalyst was all y5 moles relative to caustic potash.

The results are shown in Table 1.

Table 1 Reaction conditions Molecular weight 1500 Triol 750g Caustic potash 19.5.9 Propylene oxide 3181 It can be seen that the reaction rate is faster and the degree of unsaturation of the product is lower in all of the Examples than in Comparative Example-1.

Example 10 The product obtained in Example 1 without removing the catalyst was subjected to an addition reaction of 15φ of ethylene oxide at 120°C.

The obtained product has an OH value of 25.8 and an unsaturation degree of 0.040.
Met.

Comparative Example 2 The product obtained in Comparative Example-1 before removing the catalyst was subjected to an addition reaction of 15φ of ethylene oxide at 120°C.

The obtained product has an OH value of 26.3 and an unsaturation degree of 0.101.
Met.

Comparative Example-3 In Example-1, only tetrabutylammonium chloride in an amount of 1/10 times the total number of moles of caustic potash and tetrabutylammonium chloride (0.41 moles) was used as a catalyst, and Example- 1 to 1/
Experiments were conducted on a scale of 10.

That is, 75 g of a glycerin-propylene oxide adduct with a molecular weight of 1500 and 11.4.9 g of tetrabutylammonium chloride, which does not contain caustic potassium, were charged into an autoclave, and propylene oxide was added at a pressure of 5.5 kg/g.
It was introduced until it became ffl.

When this state was maintained at 110° C. for 2 hours, there was virtually no pressure drop, and it was confirmed that propylene oxide hardly reacted.

Reference Example 1 The polyols obtained in Example 10 and Comparative Example 2 are shown in the table below.
The mixture was mixed according to the foaming recipe shown in No. 2, and poured into an aluminum mold whose humidity had been adjusted to 50°C in advance.

The mold was released after 10 minutes at room temperature, and the physical properties of the foam were measured after being left at room temperature overnight.

It can be seen that the polyether polyol with a low degree of unsaturation obtained in Example 10 has superior compressive strength and compression set compared to that of Comparative Example 2.

Claims (1)

[Claims] 1. A method for producing a polyether compound by adding alkylene oxide to an active hydrogen-containing compound, in which an alkali catalyst consisting of an alkali metal compound and a phase transfer catalyst (excluding tetraalkylammonium hydroxide) are used as catalysts. ) A method for producing a polyether compound, characterized by using a combination of 2. The method of claim 1, wherein the phase transfer catalyst is a quaternary ammonium salt. 3. The method according to claim 1, wherein the active hydrogen-containing compound is a polyhydric alcohol. 4. The method according to claim 1, wherein the active hydrogen compound is a polyether polyol. 5. The method according to claim 1, wherein the alkylene oxide is propylene oxide alone or a combination of propylene oxide and ethylene oxide. 6. The method according to claim 1, wherein the polyether compound is a polyether polyol. 7 The hydroxyl value of poly-lyethyl polyol is 15-20
6. The method of claim 5, wherein: 0.