JP2910778B2 - Method for producing polyethers - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a polyether, and more particularly to a method for producing a polyether polyol.

[Prior Art] Polyethers obtained by subjecting an initiator to a ring-opening reaction of a monoepoxide such as an alkylene oxide are widely used as raw materials for synthetic resins such as polyurethane, surfactants, lubricants and other uses. The initiator is A
H) A hydroxyl group-containing compound represented by _n (A; residue obtained by removing a hydrogen atom from a hydroxyl group of a hydroxyl group-containing compound, n; an integer of 1 or more).

Examples of the initiator include a monohydric alcohol, a polyhydric alcohol, a monohydric phenol, and a polyhydric phenol. Further, compounds having a hydroxyalkylamino group (alkanolamines, amines-alkylene oxide adducts, etc.) are also used as initiators. Further, polyethers obtained by reacting the above initiator with a monoepoxide are also used as the initiator.

Polyethers are the following compounds obtained by subjecting the initiator to a ring-opening addition reaction of a large number of monoepoxides.

_{AR-O m H] n R} -O: Units were ring-opening reaction of monoepoxide m: integer conventional method of reacting the monoepoxide in the presence of alkaline catalyst as a method for producing a polyether have been widely used. As the alkali catalyst, an alkali metal compound such as potassium hydroxide or sodium hydroxide has been used. However, polyethers obtained using an alkali catalyst have the following problems. That is, an unsaturated monool generated by isomerization of a monoepoxide, particularly propylene oxide, becomes an initiator, and an unsaturated polyether monool in which a monoepoxide is ring-opened and added thereto (hereinafter also referred to as an unsaturated monool). .

As the molecular weight of polyethers increases, the ratio of isomerization increases, and this tendency becomes remarkable when the molecular weight is 6500 or more (in the case of trifunctionality). Therefore, when propylene oxide is used as the monoepoxide, the polyether having a molecular weight of 6500 or more The synthesis of the class was virtually impossible.

On the other hand, it is known to produce polyethers using double metal cyanide complexes as catalysts (US 32784).
57, US 3278458, US 3278459, US 3427256, US 3427334, US
3427335). This catalyst produces a small amount of the above-mentioned unsaturated monool, and is also capable of producing polyethers having an extremely high molecular weight.

[Problems to be Solved by the Invention] However, when polyethers are produced using the double metal cyanide complex catalyst, if the initiator has a low molecular weight, the reaction of monoepoxide does not occur, or the reaction rate is extremely slow. There is a problem. For this reason, conventionally, an initiator with a high molecular weight is used,
A large amount of catalyst had to be used.

However, a high molecular weight initiator is obtained by reacting monoepoxide with a polyhydric alcohol or the like, and it is difficult to use a double metal cyanide complex catalyst in this reaction. The use of a conventional alkali catalyst in this reaction produces unsaturated monols, and the use of an initiator containing this unsaturated monool reduces the advantage of producing polyethers using a double metal cyanide complex catalyst. Let it.

[Means for Solving the Problems] The present invention provides the following inventions which have been made to solve the above-mentioned problems.

In a method for producing a polyether by subjecting a monoepoxide to a ring-opening addition reaction with an initiator having at least one hydroxyl group in the presence of a double metal cyanide complex catalyst, a first initiator having a molecular weight per hydroxyl group of 1000 or less, A mixed initiator of a polyether second initiator having a molecular weight per hydroxyl group of 100 or more and twice or more the molecular weight per hydroxyl group of the first initiator is used, and the molecular weight per hydroxyl group is equal to that of the second initiator. A method for producing polyethers, which comprises producing polyethers that are equivalent or more.

According to the study of the present inventor, the catalytic action of the double metal cyanide complex is based on the etheric oxygen atom derived from the ring-opening unit of the monoepoxide in the initiator (hereinafter, unless otherwise specified, the etheric oxygen atom means the monoepoxide Is referred to as an etheric oxygen atom derived from the ring-opening unit) and a certain interaction of the catalyst. As described later, the double metal cyanide complex is a complex in which an organic ligand such as ether is coordinated. The high catalytic activity of the double metal cyanide complex with respect to the initiator comprising a relatively high molecular weight polyether may be attributed to the interaction between the initiator having the etheric oxygen atom and the catalyst.

Therefore, if a relatively high molecular weight initiator having this etheric oxygen atom is used as a part of the initiator, it is considered that the catalytic activity of the double metal cyanide complex increases and the catalytic activity for low molecular weight also increases. The present invention has been completed based on such a technical idea.

The second initiator according to the present invention is a relatively high molecular weight initiator having the etheric oxygen atom. The first initiator is a relatively low molecular weight initiator which has not been able to exhibit sufficient catalytic activity with the conventional double metal cyanide complex. The first initiator has no etheric oxygen atoms or has a smaller number of etheric oxygen atoms as compared to the second initiator. When a sufficient amount of monoepoxide is reacted with a mixed initiator composed of a mixture of the first initiator and the second initiator, polyethers having substantially the same molecular weight can be obtained.

The reason is that monoepoxide does not uniformly react with both initiators but mainly reacts with the low molecular weight first initiator, and the difference in molecular weight of the polyethers generated from each initiator is reduced, resulting in substantially equal molecular weights. Is considered to be a polyether. Alternatively, it is considered that the telomerization activity of the catalyst is high, and the molecular weight of the produced polyethers is averaged together with the reaction of the monoepoxide, resulting in polyethers having substantially the same molecular weight.

Therefore, for example, if both initiators have the same number of hydroxyl groups and the second initiator has the same oxyalkylene chain as the target polyether, the polyethers generated from both initiators are difficult to distinguish, and As a result, only one kind of polyether is obtained.

It is considered that the double metal cyanide complex in the present invention has the structure of the following general formula (1) as shown in the above-mentioned known examples.

M _a [M ′ _x (CN) _y ] _b (H ₂ O) _c (R) _d (1) where M is Zn (II), Fe (II), Fe (III), Co (I
I), Ni (II), Al (III), Sr (II), Mn (II), Cr
(III), Cu (II), Sn (II), Pb (II), Mo (IV), M
o (VI), W (IV), W (VI), etc., where M ′ is Fe (I
I), Fe (III), Co (II), Co (III), Cr (II), Cr
(III), Mn (II), Mn (III), Ni (II), V (IV),
V (V), etc., R is an organic ligand, a, b, x and y are positive integers depending on the valence and coordination number of the metal, and c and d are the coordination of the metal. It is a positive number that changes depending on the number.

M in the general formula (1) is preferably Zn (II), and M ′ is
Fe (II), Fe (III), Co (II), Co (III) and the like are preferable. Examples of the organic ligand include ketone, ether,
There are aldehydes, esters, alcohols, amides, nitriles, sulfides and the like. Preferred are ethers, esters, alcohols, amides and the like. Specifically, for example, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, t-butanol, N, N-
And dimethylacetamide.

As described above, the double metal cyanide complex represented by the general formula (1) includes a metal salt MX _a (M, a is the same as described above, X is an anion forming a salt with M) and polycyano metallate (salt)
_Ze [ _M'x (CN) _y ] _f (M ', x, y is the same as above. Z is hydrogen, alkali metal, alkaline earth metal, etc., e, f is Z,
The respective aqueous solutions or the mixed solvent solutions of water and an organic solvent were mixed together, and the organic metal ligand R was brought into contact with the obtained double metal cyanide. Thereafter, it is produced by removing excess solvent and organic compound R.

Polycyanometallate (E) _Ze [ _M'x (CN) _y ] _f
In Z, various metals including hydrogen and alkali metals can be used as Z, but lithium salts, sodium salts, potassium salts, magnesium salts, and calcium salts are preferable. Particularly preferred are ordinary alkali metal salts, that is, sodium salts and potassium salts.

As the initiator, a polyhydroxy compound having 2 to 8 hydroxyl groups is particularly preferable. Examples of the polyhydroxy compound include dihydric alcohols such as ethylene glycol and propylene glycol, trihydric alcohols such as glycerin, trimethylolpropane, and hexanetriol; tetravalent or higher valents such as pentaerythritol, diglycerin, dextrose, sorbitol, and sucrose. There are alcohols and polyethers having a lower molecular weight than the target product obtained by reacting a monoepoxide such as an alkylene oxide with these alcohols.

Compounds having a phenolic hydroxyl group or a methylol group such as bisphenol A, resole, and novolak;
There are compounds having a hydroxyl group and other active hydrogen such as ethanolamine and diethanolamine, and polyethers having a lower molecular weight than the target product obtained by reacting a monoamine or polyamine with a monoepoxide such as alkylene oxide.

The first initiator is an initiator having a molecular weight per hydroxyl group of 1,000 or less among the above-described initiators. Preferably, the molecular weight per hydroxyl group is 200 or less, especially 1
The initiator is 00 or less. It is preferable that this initiator does not have an etheric oxygen atom, or even if it has an etheric oxygen atom, the number is not more than twice the number of hydroxyl groups. The compound is preferably a monohydric or polyhydric alcohol or phenol or an alkylene oxide adduct thereof (the number of addition is 2 or less per hydroxyl group).

The second initiator has a molecular weight per hydroxyl group of 100 or more and 2 of the molecular weight per hydroxyl group of the first initiator.
It is a polyether-based initiator that is twice or more. The molecular weight per hydroxyl group of the second initiator is preferably 150 or more, particularly preferably 250 or more. The upper limit depends on the target polyethers, and is usually a molecular weight slightly lower than the molecular weight per hydroxyl group of the target polyethers.

The molecular weight per hydroxyl group of the second initiator is:
It must be at least twice the molecular weight per hydroxyl group of the first initiator used in combination therewith. If the difference between the two molecular weights is small, the features of the present invention will not be exhibited. Preferably, the difference is at least 5 times, especially at least 10 times. The compound is preferably a mono- or polyhydric alcohol or a monoepoxide adduct such as an alkylene oxide of a phenol. The addition amount of the monoepoxide is preferably 1 or more, particularly preferably 2 or more per hydroxyl group.

The amount of the first initiator in the mixed initiator composed of the first initiator and the second initiator (each initiator may be two or more types) is not particularly limited, but is 2 to 95% by weight, particularly 5 to 5% by weight. Preferably it is 80% by weight.

The amount of the double metal cyanide complex catalyst used is not particularly limited, but may be 30 to 5000 based on the second initiator used.
About ppm is appropriate, and 100-2000 ppm is more preferable.

The catalyst may be introduced into the reaction system in a lump at first, or may be divided and introduced sequentially. However, since the catalyst is considered to have some interaction with the second initiator as described above, it is preferable to use the catalyst in advance by mixing it with the second initiator.

For example, the mixture may be heated to enhance its interaction, or the second initiator synthesized using the double metal cyanide complex catalyst may be used while maintaining the activity of the catalyst contained therein. Is preferably used as a mixture of the second initiator and the catalyst. In particular, it is preferable to use a second initiator containing an active catalyst obtained by reacting at least a part of a monoepoxide in the presence of a catalyst.

The monoepoxide in the present invention is a monoepoxide having 2 or more carbon atoms, and particularly preferably an alkylene oxide having 2 or more carbon atoms. More preferred are alkylene oxides having 2 to 4 carbon atoms such as propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, epichlorohydrin, and ethylene oxide, and most preferred is propylene oxide. These can be used alone or in combination of two or more thereof and other monoepoxides such as styrene oxide, glycidyl ether and glycidyl ester.

In the case of using two or more alkylene oxides or using an alkylene oxide and another monoepoxide, they can be mixed and added or sequentially added to form a random polymerized chain or a block polymerized chain.

The polyethers obtained by the method of the present invention are preferably polyoxyalkylene polyols. The polyoxyalkylene polyol is obtained by sequentially performing a ring-opening addition reaction of a monoepoxide such as an alkylene oxide to an initiator having at least two hydroxyl groups.

Although the molecular weight of the obtained polyethers is not particularly limited, the lower limit of the molecular weight is, as described above, particularly since the object of the present invention is to produce polyethers having a high molecular weight.
The hydroxyl value is preferably 60 or less, particularly preferably 40 or less. The lower limit of the hydroxyl value is not particularly limited, but is usually about 5.

Polyethers are produced by reacting a mixture of a monoepoxide and an initiator in the presence of a catalyst. Further, the reaction can be carried out while gradually adding the monoepoxide to the reaction system. An organic solvent may be present in the reaction system. The reaction occurs at room temperature, but if necessary,
The reaction system can be heated or cooled. Normally,
50-150 ° C, preferably 80-120 ° C is employed.

The polyether polyol obtained by the present invention is most useful as a polyol for a polyurethane raw material used alone or in combination with other polyols. Further, the polyether polyol or polyether monol obtained according to the present invention is also used for raw materials and additives of synthetic resins other than polyurethane. Further, it can be used as lubricating oil, insulating oil, hydraulic oil, other oils, or as a raw material thereof. Further, the polyethers obtained according to the present invention can be converted into other compounds such as alkyl ether compounds and acyl compounds to be used for various applications.

Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited to only these Examples.

[Example] (Example 1) Synthesized using zinc hexacyanocobaltate-glyme as a catalyst, and 100 parts (parts by weight; hereinafter the same) of polyoxypropylene triol containing 1,000 ppm of the catalyst and having a weight average molecular weight of 2000 was added with 10 parts of glycerin. Then, propylene oxide was added at 120 ° C. to synthesize polyoxypropylene triol having a weight average molecular weight of 6000. Looking at the molecular weight distribution of the polyoxypropylene triol after completion of the synthesis, it was a polyol having a single peak at a weight average molecular weight of 6000.

(Example 2) Weight average molecular weight synthesized using zinc hexacyanocobaltate-glyme as a catalyst and containing the catalyst at 800 ppm
100 parts of ethylene glycol was added to 100 parts of 1000 polyoxypropylene diol, and propylene oxide was added at 120 ° C. to synthesize a polyoxypropylene diol having a weight average molecular weight of 1500. The molecular weight distribution of the polyoxypropylene diol after completion of the synthesis was a polyol having a single peak at a weight average molecular weight of 1500.

(Example 3) Weight average molecular weight synthesized using zinc hexacyanocobaltate-glyme as a catalyst and containing 300 ppm of the catalyst
150 parts of glycerin was added to 100 parts of 1000 polyoxypropylene triol, and propylene oxide was added at 120 ° C. to synthesize polyoxypropylene triol having a weight average molecular weight of 1100. Looking at the molecular weight distribution of the polyoxypropylene triol after completion of the synthesis, it was a polyol having a single peak at a weight average molecular weight of 1100.

(Comparative Example 1) Zinc hexacyanocobaltate-glyme was added to glycerin at 1000 ppm, propylene oxide was added, and the mixture was heated to 120 ° C.
For 2 hours, but propylene oxide did not substantially react.

(Comparative Example 2) Zinc hexacyanocobaltate in methyl alcohol
Add 300 ppm glyme, add prolene oxide and add 12 ppm
Stirring was continued at 0 ° C. for 3 hours, but propylene oxide did not substantially react.

[Effects of the Invention] The present invention enables the use of a low-molecular-weight initiator, which was conventionally difficult to use, when producing a high-molecular-weight polyether using a double metal cyanide complex catalyst. . Conventionally, it has been necessary to use a polyether having a relatively high molecular weight as an initiator or to use a large amount of a catalyst.

In the present invention, a high molecular weight polyether obtained by reacting a monoepoxide with a low molecular weight initiator can be obtained by using a low molecular weight initiator and a polyether initiator having a relatively high molecular weight. Moreover,
Since a product having a molecular weight substantially equal to that of a polyether obtained from a polyether-based initiator is obtained, if the number of hydroxyl groups of the initiator is the same, a product that can be regarded as a single polyether is obtained.

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Claims (5)

(57) [Claims] 1. A method for producing polyethers by subjecting an initiator having at least one hydroxyl group to a ring-opening addition reaction with an initiator having at least one hydroxyl group in the presence of a double metal cyanide complex catalyst, wherein the molecular weight per hydroxyl group is 1,000 or less. A mixed initiator of 1 initiator and a second initiator of a polyether type having a molecular weight per hydroxyl group of 100 or more and twice or more the molecular weight per hydroxyl group of the first initiator, wherein the molecular weight per hydroxyl group is used. A method for producing polyethers, which comprises producing polyethers that are equal to or more than the second initiator. 2. The first initiator is a monohydric or polyhydric alcohol or phenol or an alkylene oxide adduct thereof, and has a molecular weight per hydroxyl group.
The production method according to claim 1, wherein the number is 200 or less. 3. The second initiator is an alkylene oxide adduct of a monohydric or polyhydric alcohol or phenol, has at least one oxyalkylene group per hydroxyl group, and has a molecular weight per hydroxyl group. 3. The production method according to claim 1, wherein the polyether initiator is 150 or more. 4. The method according to claim 1, wherein the first initiator and the second initiator have the same number of hydroxyl groups, and the produced polyether is a polyether which can be regarded as a single polyether. Or the production method according to 3. 5. The amount of the first initiator in the mixed initiator is 5 to 80% by weight, and the amount of the double metal double metal cyanide complex catalyst is 100% by weight of the second initiator.
The production method according to claim 1, 2, 3 or 4, wherein the concentration is 20002000 ppm.