JP3599027B2 - Continuous production method of polyethers - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for continuously producing polyethers, and more particularly to a method for continuously producing polyethers using a double metal cyanide complex catalyst.
[0002]
[Prior art]
Polyethers obtained by ring-opening addition polymerization of monoepoxides such as alkylene oxides as initiators are used as raw materials for synthetic resins such as polyurethane, media such as lubricating oils, surfactants such as nonionic surfactants, etc. Used for applications.
[0003]
The ring-opening addition polymerization of monoepoxide requires a catalyst. As the catalyst, a complex metal cyanide complex is known in addition to a conventionally known alkali catalyst (see US Pat. Nos. 3,287,457, 3,287,458 and 3,287,459).
[0004]
[Problems to be solved by the invention]
From the economic viewpoint, a continuous production method is preferable as a method for producing polyethers, but a production method for polyethers using a double metal cyanide complex catalyst is usually a batch method (batch method). There are many. That is, a method in which a catalyst and an initiator are charged into a reaction vessel, nitrogen replacement is performed, monoepoxide is supplied and reacted, and when a predetermined amount of monoepoxide has reacted, the reaction is stopped, and the resulting polyether is taken out.
[0005]
However, this method has the drawbacks that the volume produced depends on the size of the reaction tank, that it must be washed each time to prevent the incorporation of pre-products, and that the production volume of the product relative to the size of the equipment is small. Was.
[0006]
A continuous production method using an alkali catalyst is known, but has a disadvantage that the molecular weight distribution of the obtained polyethers is too wide.
[0007]
[Means for Solving the Problems]
The present invention has been made to solve the above-mentioned problems, and provides a continuous method for producing polyethers using a double metal cyanide complex catalyst in the method for producing polyethers.
[0008]
The present invention relates to a method of performing a ring-opening addition polymerization reaction of a monoepoxide having 2 or more carbon atoms with an initiator in the presence of a double metal cyanide complex catalyst. A method for continuously producing ethers, wherein the continuous reaction tank is a reaction tank having a flow path through which a substance can move in a certain direction, and a raw material supply port is provided at a start point of the flow path and a reaction product is provided at an end point of the flow path. An annular continuous reaction tank having an outlet, or a reaction tank having a flow path through which a substance can move in a certain direction, and a raw material supply port at a start point of the flow path, a reaction product outlet at an end point, and annular continuous reactor der having a raw material supply port to the middle point between the start point and the end point is, the supply amount of the monoepoxide from one raw material supply port (a monoepoxide amount), the supply of all the initiator Amount (assuming total initiator amount Contrast, the monoepoxide amount / total amount of initiator <3 (weight ratio), a continuous production method of polyethers, characterized in that.
[0009]
The double metal cyanide complex in the present invention is considered to have a structure represented by the following general formula (1) as shown in the above-mentioned known examples.
[0010]
^{_{M 1 a [M 2 x (}} CN) y] b (H 2 O) c R d ... (1)
Here, M ¹ is Zn (II), Fe (II), Fe (III), Co (II), Ni (II), Al (III), Sr (II), Mn (II), Cr (III), Cu (II), Sn (II ), Pb (II), Mo (IV), Mo (VI), W (IV), W (VI) and the like, ^{M 2} is Fe (II), Fe (III ) , Co (II), Co (III), Cr (II), Cr (III), Mn (II), Mn (III), Ni (II), V (IV), V (V), etc. 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 positive numbers depending on the coordination number to the metal.
[0011]
In formula (1), M ¹ is preferably Zn (II), and M ² is preferably Fe (II), Fe (III), Co (II), Co (III) or the like. Examples of the organic ligand include ketone, ether, aldehyde, ester, alcohol, and amide.
[0012]
The double metal cyanide complex represented by the general formula (1) includes a metal salt M ¹ X _a (M ¹ , a is the same as described above, X is an anion that forms a salt with M ¹ ) and polycyano metallate (salt) _Ze [M ² _x (CN) _y ] _f (M ² , x, y are the same as above. Z is hydrogen, an alkali metal, an alkaline earth metal, etc. e and f are the valences of Z and M ^2. Aqueous solution or a mixed solvent solution of water and an organic solvent, and contacting the resulting complex metal cyanide with an organic ligand R. Produced by removing ligand R.
[0013]
Although various metals including hydrogen and alkali metals can be used as Z in polycyanometallate (salt) _Ze [M ² _x (CN) _y ] _f , lithium salt, sodium salt, potassium salt, magnesium Salts and calcium salts are preferred. Particularly preferred are ordinary alkali metal salts, that is, sodium and potassium salts.
[0014]
The continuous reaction vessel in the present invention is a reaction vessel having a flow path through which a substance can move in a certain direction, and a reaction vessel having a raw material supply port at a start point of the flow path and a reaction product take-out port at an end point. Or, a reaction vessel having a flow path through which a substance can move in a certain direction, and a raw material supply port at a start point of the flow path, a reaction product take-out port at an end point, and a halfway between the start point and the end point. This is a reaction tank having a raw material supply port at a point. FIG. 1 shows a cross-sectional view of one example of the annular continuous reaction tank in the present invention. The direction of the arrow in the figure indicates the direction in which the substance flows (the same applies hereinafter).
[0015]
A raw material for starting a reaction is supplied from a raw material supply port 4 provided at a starting point 1. From the reaction product outlet 5 provided at the end point 2, the produced polyether, unreacted raw materials and catalyst are taken out. At an intermediate point 3 between the start point 1 and the end point 2, one or more raw material supply ports 6 for supplying an additional raw material may be provided.
[0016]
It is preferable that the raw material is pressure-fed from the raw material supply port 4 at the starting point 1 and / or the raw material supply port 6 at the midpoint 3 by a liquid feed pump, a gas medium, or the like. That is, the raw materials pumped from the raw material supply ports 4 and 6 at the starting point and / or the intermediate point flow toward the reaction product outlet 5 at the end point 2 while reacting, and flow together with the unreacted raw materials as the generated polyether. The reaction product is taken out at the reaction product take-out port 5 at the end point 2.
[0017]
In this case, the average feed rate of the raw materials, that is, the pressure feed rate of the raw materials, is preferably 0.01 to 1 m ³ / hour per 1 m ³ of the reaction tank. Further, the supply amount of monoepoxide (referred to as monoepoxide amount) from one raw material supply port is based on the supply amount of all initiators (referred to as total initiator amount) / monoepoxide amount / total initiator amount <3 (weight ratio). ) .
[0018]
When there is no raw material supply port at an intermediate point, an initiator, a double metal cyanide complex catalyst and a monoepoxide are supplied from the raw material supply port 4 at the starting point. When the raw material supply port 6 is provided at the intermediate point 3, the initiator and the double metal cyanide complex catalyst are supplied from the raw material supply port 4 at the starting point, and the monoepoxide is supplied from the raw material supply port 6 at the intermediate point 3. However, it is not limited to this.
[0019]
Also, as described below, when two or more continuous reaction tanks are connected in series and used, from the starting point of the second or subsequent continuous reaction tank, the reaction product is taken out from the reaction product outlet of the preceding continuous reaction tank. The reaction product containing the resulting polyether to be produced and additional raw materials as needed.
[0020]
As a method of supplying the double metal cyanide complex catalyst to the continuous reaction tank, a method of supplying the mixed metal cyanide complex catalyst by mixing it in the initiator, a method of synthesizing the double metal cyanide complex catalyst in the initiator and supplying it in a state of being stably dispersed Is preferred.
[0021]
It is preferable to supply mainly the monoepoxide from the raw material supply port 6 at the intermediate point 3. Further, the number of the raw material supply ports 6 at the intermediate point 3 is not limited.
[0022]
As the continuous reaction tank, an annular continuous reaction tank described below is used.
[0023]
FIG. 1 shows a schematic view of one example of the annular continuous reaction tank. The annular continuous reaction tank is a reactor composed of an annular tube, and a feed pump 15 is attached to a part of the annular tube. The raw material supplied from the raw material supply port 4 provided at the starting point 1 and the raw material supply port 6 at the intermediate point 3 is pumped by the pump 15 and flows through the annular pipe in the direction of the arrow. The reaction product is taken out from the reaction product take-out port 5 provided at the end point 2 as product polyether.
You may use the heat exchanger type continuous reaction tank which added the function of the heat exchanger to the said continuous reaction tank.
[0024]
Further, two or more continuous reaction tanks may be connected in series. For example, if n continuous reactors are connected, the product polyether containing unreacted monoepoxide and catalyst taken out from the end point of the k-th continuous reactor less than n is converted to the (k + 1) -th continuous reactor. Supplied from the starting point. At this time, additional monoepoxide and double metal cyanide complex catalyst can be supplied from the starting point of the (k + 1) th continuous reaction tank.
[0025]
In the present invention, by connecting two or more continuous reaction tanks in series, polyethers produced using only one continuous reaction tank can be further increased in molecular weight.
[0026]
The polyethers obtained by the method of the present invention are preferably polyoxyalkylene polyols. The polyoxyalkylene polyol is obtained by sequentially subjecting an initiator having at least two hydroxyl groups to a ring-opening addition polymerization reaction of a monoepoxide such as an alkylene oxide.
[0027]
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 polyether polyols having a lower molecular weight than the target product obtained by reacting a monoepoxide such as an alkylene oxide with these alcohols.
[0028]
Compounds having a phenolic hydroxyl group or a methylol group such as bisphenol A, resol, and novolak; compounds having a hydroxyl group such as ethanolamine and diethanolamine and other active hydrogen; and compounds obtained by reacting these with a monoepoxide such as an alkylene oxide. There are polyether polyols of lower molecular weight than the desired product.
[0029]
Furthermore, there is a polyether polyol having a molecular weight lower than that of a target product obtained by reacting a monoamine or a 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.
[0030]
The present invention can also be applied to a method for producing a polyether monol by subjecting a monovalent initiator to a ring opening reaction of a monoepoxide. Examples of the monovalent initiator include methanol, ethanol, butanol, hexanol, other monools, phenol derivatives such as phenols and alkyl-substituted phenols, and products obtained by reacting these with monoepoxides such as alkylene oxides. There are also low molecular weight polyether polyols. Furthermore, there is a polyether polyol 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.
[0031]
The monoepoxide in the present invention is a monoepoxide having 2 or more carbon atoms, particularly preferably an alkylene oxide having 2 or more carbon atoms. More preferred are alkylene oxides having 3 to 4 carbon atoms such as ethylene oxide, propylene oxide, butylene oxide and epichlorohydrin, and most preferred is propylene oxide. They may be used alone, or two or more of them may be used in combination with 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 polymer chain or a block polymer chain.
[0032]
The molecular weight of the obtained polyethers is not particularly limited. Preferably, the amount of monoepoxide reacted per mole of initiator is at least about 10 moles, more preferably at least about 50 moles. An average of at least about 10 molecules per hydroxyl group of the initiator is particularly preferred, and polyethers obtained by reacting at least about 30 molecules are most preferred.
[0033]
In terms of the hydroxyl value, 200 or less, particularly 100 or less is appropriate. For example, as a raw material for polyurethane, a liquid polyether polyol having a hydroxyl value of about 5 to 200, particularly 5 to 60 is preferable.
[0034]
When a normal alkali catalyst is used, polyethers synthesized in a continuous reaction tank have a drawback that the molecular weight distribution is wide. It is known that the synthesis reaction of polyethers by the double metal cyanide complex catalyst is characterized in that monoepoxide reacts and polymerizes with the terminal of polyethers having lower molecular weight. Therefore, the molecular weight distribution does not spread.
[0035]
Further, the ring-opening addition polymerization reaction of monoepoxide with a double metal cyanide complex catalyst is suitable for continuation since the reaction occurs quickly.
[0036]
【Example】
Reference examples (Examples 2 and 4) are shown below .
[0037]
[Example 2]
A trifunctional polyol obtained by partially polymerizing with a 150 ppm double metal cyanide complex catalyst in a semi-batch reactor from a molecular weight of 800 to a molecular weight of 1000 to a molecular weight of 1,000 is used as an initiator, and is made of stainless steel having a capacity of 500 cm ³ . It was supplied at a rate of 15 g / hour from the starting point of the heat exchanger type tubular continuous reaction tank. A total of 210 g / hour of propylene oxide was supplied from 20 points on the way, and the reaction was carried out at a reaction temperature of 130 ° C. As a result, a polyether polyol having a weight average molecular weight of 14,000 was continuously synthesized and taken out.
[0039]
[Example 4]
Using a stainless steel complete mixing tank having a capacity of 5000 cm ³ , 2000 ppm of a double metal cyanide complex catalyst and 500 g of a trifunctional polyol having a molecular weight of 1000 as an initiator were supplied. Propylene oxide was supplied at a reaction temperature of 120 ° C. When the propylene oxide supply rate was set to 1800 g / hour, the reaction pressure increased, causing problems such as insufficient cooling rate, and the necessity of washing each time. Therefore, the actual productivity was 1/3 or less of the feed rate of the polymerization raw material.
[0040]
【The invention's effect】
According to the present invention, polyethers can be efficiently and continuously produced.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an example of an annular continuous reaction tank according to the present invention.
1: Start point 2: End point 3: Midway point 4: Raw material supply port 5: Reaction product outlet 6: Raw material supply port 14: Reactor 15: Pump

Claims (3)

In conducting a ring-opening addition polymerization reaction of a monoepoxide having 2 or more carbon atoms with an initiator in the presence of a double metal cyanide complex catalyst, a continuous reaction of a polyether which continuously performs a ring-opening addition polymerization reaction using a continuous reaction tank. A manufacturing method,
A continuous reaction vessel is a reaction vessel having a flow path through which a substance can move in a certain direction, and an annular continuous reaction vessel having a raw material supply port at a start point of the flow path and a reaction product outlet at an end point, or A reaction vessel having a flow path through which a substance can move in a certain direction, and a raw material supply port at a start point of the flow path, a reaction product outlet at an end point, and an intermediate point between the start point and the end point. annular continuous reactor der having a raw material supply port to is,
The supply amount of monoepoxide (referred to as monoepoxide amount) from one raw material supply port is the amount of monoepoxide / total initiator amount <3 (weight) with respect to the supply amount of all initiators (referred to as total initiator amount). Ratio) , a continuous method for producing polyethers. The continuous production method according to claim 1, wherein when supplying the raw material, the raw material is pressure-fed from a raw material supply port at a starting point and / or an intermediate point. Material having an average pumping rate when pumping is the reaction vessel 1 m ³ per 0.01~1m ³ / time, a method of continuous manufacturing according to claim 2.

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