JP2595766B2 - Method for producing polyoxyalkylene alcohol - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a polyoxyalkylene alcohol.

[Prior art] Polyoxyalkylene alcohols use a compound having an active hydrogen-containing functional group capable of reacting with an alkylene oxide such as a hydroxyl group, an amino group or a carboxylic acid group as an initiator, and ring-opening the alkylene oxide to the initiator. A compound synthesized by polymerization and having an ether bond in the molecular chain and a hydroxyl group as a terminal group. Polyoxyalkylene alcohols having two or more hydroxyl groups (polyoxyalkylene polyols), also called polyether polyols, are one of the main raw material compounds in the polyurethane industry and the like, and are industrially important compounds. . In addition, polyoxyalkylene alcohols having one or more hydroxyl groups are widely used as surfactants, oils, and the like, or as raw materials thereof. By selecting an initiator having an arbitrary number of functional groups as the initiator, the polyoxyalkylene alcohol can have a corresponding arbitrary number of hydroxyl group terminals. The number of functional groups of the initiator is, in principle, any number of 1 or more, and is generally selected in the range of 1 to 8.

As described above, a typical example of the polyoxyalkylene alcohol in the present invention is a polyoxyalkylene alcohol having two or more hydroxyl groups, that is, a polyoxyalkylene polyol. Hereinafter, the present invention will be described mainly with reference to a polyoxyalkylene polyol, but the present invention does not exclude a polyoxyalkylene alcohol having one hydroxyl group, that is, a polyoxyalkylene monool.

As a method for producing polyoxyalkylene alcohol by ring-opening polymerization of alkylene oxide, a method using a double metal cyanide complex such as cobalt zinc cyanide-glyme as a catalyst is described in the following U.S. Patent and EP283148.

USP 3278457, USP 3278458, USP 3278459, USP 3427256, USP 3427334, USP 3427335, USP 3829505, USP 3941849, USP 4355188, USP 4472560, USP 4721818 Characteristically, it allows the production of polyoxyalkylene alcohols with low by-product formation and therefore higher molecular weight. Furthermore, the molecular weight distribution of the resulting polyoxyalkylene alcohol is narrow. However, according to the study of the present inventors, these performances are different depending on the type of each double metal cyanide complex catalyst, and not all of them have the same performance. In addition, the double metal cyanide complex catalyst in which by-product formation is smaller or the molecular weight is higher, and the double metal cyanide complex catalyst in which the molecular weight distribution is narrower have contradictory properties. That is, when the former catalyst was used, the molecular weight distribution was broadened, and when the latter catalyst was used, the amount of by-products was increased, and it was difficult to produce a higher molecular weight polyoxyalkylene alcohol. Therefore, in producing a polyoxyalkylene alcohol by ring-opening polymerization of an alkylene oxide, optimization of these double metal cyanide complex catalysts is desired. In particular, it has been desired to produce a high molecular weight polyoxyalkylene alcohol having a narrow molecular weight distribution, which is difficult to produce with the above-mentioned catalysts.

[Means for Solving the Problems] The present invention basically provides the following method for producing a polyoxyalkylene alcohol.

In a method for producing a polyoxyalkylene alcohol by subjecting an initiator to ring-opening polymerization of an alkylene oxide in the presence of a double metal cyanide complex catalyst, a double metal cyanide in which by-products are reduced or the molecular weight is higher in the former stage A method for producing a polyoxyalkylene alcohol, comprising using a complex catalyst and a double metal cyanide complex catalyst having a narrower molecular weight distribution in a later stage.

It is considered that the double metal cyanide complex in the present invention has a structure represented by 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, aldehyde, ester, alcohol, and amide.

As described above double metal cyanide complex represented by the general formula (1) is a metal salt MX _a (M, a is as described above, X is an anion which forms a M salts) and poly cyanometalate (salt) Z _e
[X ′ _x (CN) _y ] _f (M ′, x, y is the same as above. Z is hydrogen, alkali metal, alkaline earth metal, etc., and e, f is Z, M ′
Are mixed with each other or a solution of a mixed solvent of water and an organic solvent, and the resulting double metal cyanide is brought into contact with an organic ligand R. Produced by removing excess solvent and organic compound R.

Polycyanometallate (salt) _Ze [ _X'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 double metal cyanide complex catalyst in which the by-product formation is reduced, when a polyoxypropylene alcohol having a weight average molecular weight of 5,000 is produced, the weight fraction of the by-product is 6% or less. Preferably, there is. The double metal cyanide complex catalyst having a higher molecular weight is preferably a catalyst capable of ring-opening polymerizing 8 kg or more of propylene oxide using 1 g of the catalyst. These two catalysts are generally considered to be catalysts having the same properties. This is because a high molecular weight polyoxyalkylene alcohol can be obtained because the amount of by-products is small. The double metal cyanide complex catalyst having a narrower molecular weight distribution is preferably a catalyst in which the ratio of weight average molecular weight / number average molecular weight of polyoxypropylene alcohol produced using the catalyst is 1.3 or less. As described above, such a catalyst has more by-products than the above-mentioned catalyst, and it is difficult to increase the molecular weight of the polyoxyalkylene alcohol.

It has been found that such differences in catalyst performance are caused by differences in organic ligands even for catalysts having the same metal component. Even when the metal components are different, the influence of the organic ligand is large. According to the study of the present inventors, a catalyst in which the organic ligand is an alcohol or an amide has a high ability to produce a polyoxyalkylene alcohol having less by-product formation or a higher molecular weight. Further, a catalyst in which the organic ligand is an ether or an ester has a high ability to produce a polyoxyalkylene alcohol having a narrower molecular weight distribution. Therefore, in the present invention, as a double metal cyanide complex catalyst in which by-product formation is reduced or the molecular weight is increased, a catalyst comprising a complex in which an organic ligand is an alcohol or an amide is preferable, and the molecular weight distribution is low. As the double metal cyanide complex catalyst which becomes narrower, a catalyst comprising a chain in which the organic ligand is an ether or an ester is preferable.

The polyoxyalkylene alcohol is usually produced by reacting a mixture of monoepoxide and initiator in the presence of a catalyst. In addition, the reaction can be carried out while gradually adding monoepoxide to the reaction system. The reaction occurs at room temperature, but the reaction system can be heated or cooled if necessary. The amount of the catalyst used is not particularly limited, but is suitably about 1 to 5000 ppm, more preferably 30 to 1000 ppm, for the initiator used. The catalyst may be introduced into the reaction system in a lump at first, or may be divided and introduced sequentially. For the exchange of the first-stage catalyst and the second-stage catalyst, a method is usually employed in which the first-stage catalyst is removed after the first-stage reaction is completed, and then the second-stage catalyst is added to perform the second-stage reaction. Alternatively, the former catalyst can be deactivated by a method that does not affect the latter catalyst, and the reaction can be carried out by adding the latter catalyst while containing the deactivated former catalyst. In some cases, the latter-stage reaction can be performed by adding the latter-stage catalyst while leaving the former-stage catalyst. This method is industrially advantageous because only one step of catalyst deactivation and removal is required.

The polyoxyalkylene alcohol in the present invention is preferably a polyoxyalkylene polyol. 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.
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, and tetravalent or higher valents such as pentaerythritol, diglycerin, dextrose, sorbitol and sucrose. There are alcohols and polyoxyalkylene alcohols having a lower molecular weight than the target product obtained by reacting these alcohols with a monoepoxide such as an alkylene oxide. Compounds having a phenolic hydroxyl group or a methylol group such as bisphenol A, resole and novolak, compounds having a hydroxyl group such as ethanolamine and diethanolamine and other active hydrogens, and compounds obtained by reacting these with a monoepoxide such as an alkylene oxide. There is a polyoxyalkylene alcohol having a lower molecular weight than the intended product. Further, there is a polyoxyalkylene alcohol having a molecular weight lower than that of a target product obtained by reacting a monoamine or polyamine having at least two hydrogen atoms bonded to a nitrogen atom with a monoepoxide such as an alkylene oxide. In addition, phosphoric acid, its derivatives, and other polyhydroxy compounds can also be used. These polyhydroxy compounds may be used in combination of two or more.

The present invention is also applicable to polyoxyalkylene monols obtained by subjecting a monovalent initiator to a ring-opening reaction of monoepoxide. Monovalent initiators include, for example, methanol, ethanol, butanol, hexanol, other monols, phenol,
There are phenol derivatives such as alkyl-substituted phenols, and polyoxyalkylene alcohols having a lower molecular weight than the target product obtained by reacting these with a monoepoxide such as an alkylene oxide. Furthermore, there is a polyoxyalkylene alcohol having a molecular weight lower than that of a target product obtained by reacting a monoamine or polyamine having one hydrogen atom bonded to a nitrogen atom with a monoepoxide such as an alkylene oxide.

The monoepoxide is a monoepoxide having 2 or more carbon atoms, particularly preferably an alkylene oxide having 2 or more carbon atoms. More preferably, alkylene oxides having 3 to 4 carbon atoms such as propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, and epichlorohydrin are preferable, and propylene oxide is most preferable. The alkylene oxides having 3 to 4 carbon atoms can be used alone or in combination of two or more thereof, or in combination with other monoepoxides such as ethylene oxide, styrene oxide, glycidyl ether and glycidyl ester. When two or more alkylene oxides are used or when an alkylene oxide and another monoepoxide are used, they can be mixed and added or sequentially added to form a random polymerized chain or a block polymerized chain.

The molecular weight of the polyoxyalkylene alcohol in the present invention is not particularly limited. However, products that are liquid at room temperature are preferred in terms of their use. The reaction amount of monoepoxide with respect to 1 mol of the initiator is preferably at least about 10 mol, and more preferably at least about 50 mol. More preferably, polyoxyalkylene alcohols obtained by reacting an average of at least about 10 molecules, particularly at least about 30 molecules per hydroxyl group of the initiator are preferred. Also, if expressed in terms of hydroxyl value, it is 200 or less, especially 100
The following are appropriate: For example, as a raw material for polyurethane, a liquid polyoxyalkylene polyol having a hydroxyl value of about 5 to 200, particularly 5 to 60 is preferable. Other applications, for example, polyoxyalkylene poly (or mono) ol in the above range, such as oil raw materials such as hydraulic oil, are preferable.

The polyoxyalkylene 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. The polyoxyalkylene poly (or mono) ol obtained according to the present invention is also used as a raw material of synthetic resins other than polyurethane and as an additive.
In addition, as lubricating oil, insulating oil, hydraulic oil, and other oils,
Alternatively, it can be used as a raw material. further,
The polyoxyalkylene alcohol 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 purposes.

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited thereto.

[Example] A polyoxypropylene triol having a molecular weight of 1000 was used as an initiator, a zinc hexacyanocobaltate complex having a different organic ligand was used as a double metal cyanide complex catalyst, and propylene oxide (hereinafter, referred to as an initiator) was used at 120 ° C. , P
O)) was subjected to ring-opening polymerization. The organic ligand of each catalyst is as follows.

Catalyst A; Organic ligand = tert-butyl alcohol Catalyst B; Organic ligand = N, N-dimethylacetamide Catalyst C; Organic ligand = diethylene glycol dimethyl ether Catalyst D; Organic ligand = ethylene glycol dimethyl ether 0.1 g of the catalyst A was added to 1000 g of the initiator, and 4000 g of PO was reacted. Next, 0.5 g of catalyst C was additionally added, and 5000 g of PO was further reacted.

Example 2 0.2 g of the catalyst B was added to 1000 g of the initiator, and 4000 g of PO was reacted. Next, 0.5 g of catalyst D was additionally charged, and 5000 g of PO was further reacted.

Comparative Example 1 0.6 g of the catalyst D was added to 1000 g of the initiator, and 9000 g of PO was added to carry out the reaction, but the reaction was stopped halfway.

Comparative Example 2 0.6 g of the catalyst B was added to 1000 g of the initiator, and 9000 g of PO was added to carry out a reaction.

The weight fraction (W) and the ratio of weight average molecular weight / number average molecular weight (N) of the by-product of polyoxypropylene triol produced in the above example are shown in Table 1 below.

[Effect of the Invention] In the present invention, when a polyoxyalkylene alcohol is produced using a double metal cyanide complex catalyst, a polyoxyalkylene alcohol having a particularly narrow molecular weight distribution can be produced. It is difficult to produce a sufficiently high molecular weight polyoxyalkylene alcohol simply by using a catalyst capable of producing a polyoxyalkylene alcohol having a narrow molecular weight distribution.

Continuation of front page (56) References JP-A-3-281529 (JP, A) JP-A-58-185433 (JP, A) JP-A-58-185621 (JP, A) JP-A-63-277236 (JP, A) JP-A-2-242821 (JP, A) JP-B-44-551 (JP, B1) JP-B-46-27250 (JP, B1)

Claims (6)

(57) [Claims] A method for producing a polyoxyalkylene alcohol by subjecting an initiator to ring-opening polymerization of an alkylene oxide in the presence of a double metal cyanide complex catalyst,
Polyoxy, characterized by using a double metal cyanide complex catalyst in which the by-product formation is smaller or the molecular weight is higher in the first stage and a double metal cyanide complex catalyst in which the molecular weight distribution is narrower in the second stage. A method for producing an alkylene alcohol. 2. When a double metal cyanide complex catalyst which produces less by-products produces polyoxypropylene alcohol having a weight average molecular weight of 5000, the weight fraction of the by-products becomes 6% or less. The method according to claim 1, which is a catalyst. 3. The double metal cyanide complex catalyst having a higher molecular weight is a catalyst capable of ring-opening polymerization of 8 kg or more of propylene oxide using 1 g of the catalyst. Method. 4. The double metal cyanide complex catalyst having a narrower molecular weight distribution is a catalyst in which the ratio of weight average molecular weight / number average molecular weight of polyoxypropylene alcohol produced using the catalyst is 1.3 or less. Item 2. The method according to Item 1. 5. The method of claim 1, wherein the double metal cyanide complex catalyst with lower by-product formation or higher molecular weight comprises a complex wherein the organic ligand is an alcohol or an amide. 6. The method of claim 1 wherein the double metal cyanide complex catalyst having a narrower molecular weight distribution comprises a complex wherein the organic ligand is an ether or an ester.