WO2021140868A1 - Organozinc catalyst - Google Patents

Abstract

Provided is a means for controlling the molecular weight of a polyalkylene carbonate, when reacting a carbon dioxide with an epoxide to obtain a polyalkylene carbonate. More specifically, provided is an organozinc catalyst which is obtained by reacting a zinc compound with an aliphatic carboxylic acid and has a water content of 10-10,000 ppm.

Description

Organozinc catalyst

The present disclosure relates to an organozinc catalyst and a method for producing a polyalkylene carbonate using the catalyst. The contents of all documents described herein are incorporated herein by reference.

It is disclosed that an organozinc compound obtained by reacting a zinc compound with an aliphatic dicarboxylic acid and an aliphatic monocarboxylic acid is used as an organozinc catalyst for catalyzing a reaction for obtaining a polyalkylene carbonate from carbon dioxide and epoxide. (Patent Documents 1 and 2).

It is also disclosed that in the reaction for obtaining a polyalkylene carbonate from carbon dioxide and an epoxide, if the reaction system contains water, the reaction active site for obtaining the polyalkylene carbonate may be adversely affected. ing. Since water can be generated in the reaction of the zinc compound, the aliphatic dicarboxylic acid and the aliphatic monocarboxylic acid, it is used to catalyze the reaction for obtaining a polyalkylene carbonate while being contained in the reaction solution as an organic zinc catalyst. In this case, it is also disclosed that it is preferable to remove these waters and the like by a separation operation such as co-boiling in advance, particularly from the viewpoint of increasing the yield (Patent Documents 1 and 2).

On the other hand, it is also disclosed that when the organozinc compound used as a catalyst is completely dried, it does not show the activity of catalyzing the reaction for obtaining the polyalkylene carbonate, or the activity is very low (Patent). Document 3).

Public relations of JP-A-2007-302731 International Publication No. 2011/142259 International Publication No. 2011/107757

The present inventors have studied to develop a method for controlling the molecular weight of polyalkylene carbonate when reacting carbon dioxide with epoxide to obtain polyalkylene carbonate.

The present inventors have found that the water content of a specific organozinc catalyst that catalyzes the reaction of obtaining a polyalkylene carbonate from carbon dioxide and an epoxide may be related to the molecular weight of the obtained polyalkylene carbonate, and further improvements have been made. Stacked.

When the organozinc compound used as a catalyst is completely dried, it does not show the activity of catalyzing the reaction for obtaining the polyalkylene carbonate, or the activity is very low. Although it is described in Cited Document 3 that water is added and used as a catalyst, the amount of water added is about 2 ppm at most.

The present disclosure includes, for example, the subjects described in the following sections.
Item 1.
An organozinc catalyst obtained by reacting a zinc compound and a carboxylic acid.
Moisture content is 10 to 10000 ppm,
Organozinc catalyst.
Item 2.
Item 2. The organozinc catalyst according to Item 1, which is obtained by reacting a zinc compound and a dicarboxylic acid.
Item 3.
Item 2. The organozinc catalyst according to Item 1, which is obtained by reacting a zinc compound, a dicarboxylic acid, and a monocarboxylic acid.
Item 4.
Item The dicarboxylic acid is an aliphatic dicarboxylic acid having 2 to 15 carbon atoms (preferably at least one selected from the group consisting of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid and sebacic acid). The organic zinc catalyst according to 2 or 3.
Item 5.
The dicarboxylic acid is an aliphatic dicarboxylic acid having 2 to 15 carbon atoms (preferably at least one selected from the group consisting of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid and sebacic acid).
The monocarboxylic acid is an aliphatic monocarboxylic acid having 1 to 15 carbon atoms (preferably at least one selected from the group consisting of formic acid, acetic acid, propionic acid, and trifluoroacetic acid).
Item 3. The organozinc catalyst according to Item 3.
Item 6.
Item 2. The organozinc catalyst according to any one of Items 1 to 5, wherein the zinc compound is zinc oxide and / or zinc hydroxide.
Item 7.
Item 2. The organozinc catalyst according to Item 1, which is obtained by reacting at least zinc oxide and glutaric acid.
Item 8.
Item 2. The organozinc catalyst according to any one of Items 1 to 7, for catalyzing a reaction for obtaining a polyalkylene carbonate from carbon dioxide and an epoxide.
Item 9.
The present invention comprises reacting carbon dioxide with an epoxide in the presence of the organozinc catalyst according to any one of Items 1 to 8 to produce a polyalkylene carbonate.
A method for controlling the molecular weight of the produced polyalkylene carbonate using the water content of the organozinc catalyst used as an index.

When carbon dioxide and epoxide are reacted to produce polyalkylene carbonate, the molecular weight of the obtained polyalkylene carbonate can be controlled.

The results of the polymerization carried out in Examples 1 to 6 (relationship between the water content of the organozinc catalyst and the molecular weight of polypropylene carbonate) are shown as a graph.

Hereinafter, each embodiment included in the present disclosure will be described in more detail. The present disclosure preferably includes, but is not limited to, a specific organozinc catalyst, a method for producing a polyalkylene carbonate under the catalyst, and the like, and the present disclosure is disclosed in the present specification and recognized by those skilled in the art. Include everything you can.

The organozinc catalyst included in the present disclosure is an organozinc catalyst obtained by reacting a zinc compound and a carboxylic acid, and has a water content of 10 to 10,000 ppm. Hereinafter, the catalyst included in the present disclosure may be referred to as "organozinc catalyst of the present disclosure" or "catalyst of the present disclosure".

As described above, the catalyst of the present disclosure is obtained by reacting a zinc compound and an aliphatic carboxylic acid. In other words, the catalyst of the present disclosure can be said to be a reaction product of a zinc compound and an aliphatic carboxylic acid.

As the zinc compound, an inorganic zinc compound is preferable. Examples of the inorganic zinc compound include zinc oxide, zinc sulfate, zinc chlorate, zinc nitrate, zinc acetate, and zinc hydroxide, and zinc oxide and zinc hydroxide are more preferable. The zinc compound may be used alone or in combination of two or more.

As the aliphatic carboxylic acid, it is preferable to use at least an aliphatic dicarboxylic acid. Further, an aliphatic monocarboxylic acid and an aliphatic tricarboxylic acid can also be used. The aliphatic carboxylic acid can be used alone or in combination of two or more. Of these, it is preferable to use an aliphatic dicarboxylic acid, or to use an aliphatic dicarboxylic acid and an aliphatic monocarboxylic acid. When an aliphatic dicarboxylic acid and an aliphatic monocarboxylic acid are used, the molar ratio of the aliphatic monocarboxylic acid to the aliphatic dicarboxylic acid is about 0.0001 to 0.1 or 0.001 to 0.05. It is preferable to use it so as to be a degree.

As the aliphatic dicarboxylic acid, an aliphatic dicarboxylic acid having 2 to 15 carbon atoms (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15) is preferable. More specifically, for example, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid and the like can be mentioned. The aliphatic monocarboxylic acid has 1 to 15 carbon atoms (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15). Monocarboxylic acids are preferred, and more specific examples include formic acid, acetic acid, propionic acid, trifluoroacetic acid and the like. As the aliphatic tricarboxylic acid, an aliphatic tricarboxylic acid having 3 to 15 carbon atoms (3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15) is preferable, and more specific. Examples thereof include tricarbaryl acid and 3,3', 3''-nitrilotripropionic acid. Among the aliphatic carboxylic acids, malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, formic acid, acetic acid, and propionic acid are particularly preferable.

The ratio of the zinc compound and the aliphatic carboxylic acid used is, for example, preferably about 0.1 to 1.5 mol, more preferably about 0.5 to 1.2 mol, based on 1 mol of the zinc compound. It is preferable, and more preferably about 0.8 to 1.0 mol.

As the reaction between the zinc compound and the aliphatic carboxylic acid, a known reaction can be used, and for example, the reaction conditions described in Patent Document 1 or 2 can be used. More specifically, for example, the reaction solvent is not particularly limited, and various organic solvents can be used. Specific examples of such an organic solvent include aromatic hydrocarbon solvents such as benzene, toluene and xylene, aliphatic solvent such as hexane, heptane and cyclohexane, dichloromethane, chloroform, 1 and 2. -Halogen-based hydrocarbon solvents such as dichloroethane, alcohol-based solvents such as methanol, ethanol and isopropanol, ether-based solvents such as diethyl ether, tetrahydrofuran and dioxane, ester-based solvents such as ethyl acetate and butyl acetate, acetone, methyl ethyl ketone and methyl isobutyl. Examples thereof include ketone solvents such as ketones, carbonate solvents such as dimethyl carbonate, diethyl carbonate and propylene carbonate, and acetonitrile, dimethylformamide, dimethylsulfoxide, hexamethylphosphotriamide and the like. Of these, aromatic hydrocarbon solvents such as benzene, toluene, and xylene are preferable from the viewpoint of facilitating the reaction.

The amount of the reaction solvent used is not particularly limited, but is 500 to 10000 parts by mass with respect to 100 parts by mass of the zinc compound, for example, from the viewpoint of smoothing the reaction and obtaining an effect commensurate with the amount used. It is preferable to have.

The reaction temperature is not particularly limited, but is preferably 0 to 110 ° C, more preferably 20 to 100 ° C, and even more preferably 50 to 80 ° C. When the reaction temperature is 0 ° C. or higher, the reaction can proceed more efficiently. Further, when the reaction temperature is 110 ° C. or lower, side reactions are less likely to occur, and a decrease in yield can be suppressed. The reaction time varies depending on the reaction temperature and cannot be unequivocally determined, but is, for example, 1 to 20 hours.

Further, the reaction is preferably carried out in an atmosphere of an inert gas (for example, nitrogen).

Although not particularly limited, an organic zinc catalyst obtained by reacting at least zinc oxide and glutaric acid can be mentioned as a particularly preferable form of the catalyst of the present disclosure. The organozinc catalyst is, for example, one in which only zinc oxide is reacted as a zinc compound, one in which only glutaric acid is reacted as an aliphatic carboxylic acid, or one in which only zinc oxide and glutaric acid are reacted. Is preferably included.

As described above, the catalyst of the present disclosure has a water content of 10 to 10000 ppm. The lower limit of the range may be, for example, 20, 30, 40, 50, 60, 70, 80, 90, or 100 ppm. Further, the upper limit of the range may be, for example, 9000, 8000, 7000, 6000, 5000, 4000, 3000, 2000, or 1800 ppm. For example, the range is preferably 10 to 5000 ppm, more preferably 20 to 3000 ppm.
The water content is a value obtained by vaporizing the water content in the catalyst and measuring the water content by the Karl Fischer method. A moisture vaporizer (for example, manufactured by Hiranuma Sangyo, product name "EV-6") can be used for moisture vaporization in the catalyst. Further, for the measurement by the Karl Fischer method, a Karl Fischer moisture meter (for example, manufactured by Hiranuma Sangyo, product name "AQ-300") can be used.

The catalyst of the present disclosure is preferably used for catalyzing a reaction (copolymerization reaction) for obtaining a polyalkylene carbonate from carbon dioxide and an epoxide. The present disclosure also preferably includes a method for producing a polyalkylene carbonate by reacting (copolymerizing) carbon dioxide and an epoxide under the catalyst of the present disclosure.

The epoxide is not particularly limited, but for example, ethylene oxide, propylene oxide, 1-butane oxide, 2-butane oxide, isobutylene oxide, 1-pentene oxide, 2-pentene oxide, 1-hexene oxide, 1-. Octene oxide, 1-decene oxide, cyclopentene oxide, cyclohexene oxide, styrene oxide, vinylcyclohexane oxide, 3-phenylpropylene oxide, 3,3,3-trifluoropropylene oxide, 3-naphthylpropylene oxide, 3-phenoxypropylene oxide, Examples thereof include 3-naphthoxypropylene oxide, butadiene monooxide, allylglycidyl ether, 3-vinyloxypropylene oxide and 3-trimethylsilyloxypropylene oxide. Of these, ethylene oxide and propylene oxide are preferable from the viewpoint of having high reactivity. These epoxides may be used alone or in combination of two or more.

The working pressure of carbon dioxide is not particularly limited, but is usually preferably 0.1 to 20 MPa, more preferably 0.1 to 10 MPa, and even more preferably 0.1 to 5 MPa. Carbon dioxide may be supplied in a lump sum, intermittently, or continuously.

The amount of the organozinc catalyst used is, for example, preferably 0.001 to 50 parts by mass, more preferably 0.01 to 40 parts by mass, and 0.1 to 30 parts by mass with respect to 100 parts by mass of the epoxide. It is more preferably a part.

The solvent used in the copolymerization reaction is not particularly limited, and various organic solvents can be used. Specific examples of such an organic solvent include aliphatic hydrocarbon solvents such as pentane, hexane, octane, decane and cyclohexane; aromatic hydrocarbon solvents such as benzene, toluene and xylene; dichloromethane and chloroform. , 1,2-Dichloroethane, chlorobenzene, bromobenzene and other halogenated hydrocarbon solvents; ethyl acetate, isopropyl acetate, butyl acetate and other ester solvents; tetrahydrofuran, 1,4-dioxane and other ether solvents; dimethyl carbonate, diethyl Examples thereof include carbonate-based solvents such as carbonate and propylene carbonate.

The amount of the solvent used is not particularly limited, but is, for example, 100 to 10000 parts by mass with respect to 100 parts by mass of the epoxide from the viewpoint of smoothing the reaction and obtaining an effect commensurate with the amount used. Is preferable. Moreover, it is not necessary to use a solvent.

The method for producing the polyalkylene carbonate has different polymerization forms such as solution polymerization and precipitation polymerization depending on the type and amount of the solvent used, but the copolymerization reaction proceeds without any problem in any of the polymerization forms. , Their reaction efficiency is very high.

The reaction temperature of the copolymerization reaction is not particularly limited, but is preferably, for example, 20 to 100 ° C, more preferably 40 to 80 ° C. The reaction time cannot be unequivocally determined because it varies depending on the reaction temperature, but is, for example, 2 to 40 hours.

The method for mixing the organozinc catalyst with carbon dioxide and epoxide is not particularly limited, but for ease of mixing, for example, there is a method of adding carbon dioxide after mixing the organozinc catalyst with epoxide. ..

Further, the polyalkylene carbonate thus obtained is dried by using a vacuum drying method or the like after removing the catalyst or the like by filtration or washing with a dilute acid aqueous solution or a dilute alkaline aqueous solution, if necessary, and then reprecipitating. Can be isolated by

Furthermore, the present disclosure includes reacting carbon dioxide with an epoxide in the presence of the organozinc catalyst to produce a polyalkylene carbonate, and the polyalkylene carbonate produced using the water content of the organozinc catalyst used as an index. Also preferably includes a method of controlling the molecular weight of.

In the reaction of carbon dioxide and epoxide in the presence of the organozinc catalyst to produce polyalkylene carbonate, the present inventors have a water content of 10 to 10000 ppm (preferably, for example, 10 to 5000 ppm) of the organozinc catalyst. , More preferably in the range of, for example, 20 to 3000 ppm), it was found that there is a correlation between the water content and the molecular weight of the obtained polyalkylene carbonate.

Therefore, the molecular weight of the polypropylene carbonate to be produced can be controlled by adjusting the water content of the organozinc catalyst. Further, the water content of the organozinc catalyst can be appropriately adjusted by adjusting the drying treatment (for example, adjusting the drying treatment time).

In this method, for example, when the molecular weight of the polypropylene carbonate to be produced is about 10,000 to 40,000 (preferably about 20,000 to 35,000), it correlates strongly with the water content of the organozinc catalyst. In the case of producing polypropylene carbonate, it is particularly preferable to use this method.

In this specification, "including" also includes "consisting of" and "consisting of" (The term "comprising" includes "consisting essentially of" and "consisting of."). The present disclosure also includes all combinations of the constituent requirements described herein.

Further, the various characteristics (property, structure, function, etc.) described for each embodiment of the present disclosure described above may be combined in any way in specifying the subject matter included in the present disclosure. That is, the present disclosure includes all subjects consisting of any combination of each combinable property described herein.

Hereinafter, embodiments of the present disclosure will be described in more detail with reference to examples, but the embodiments of the present disclosure are not limited to the following examples.

Each analysis was performed by the following method.
<Measurement of water content of zinc catalyst>
Regarding the moisture content of the zinc catalyst described in Examples and Production Examples, the moisture vaporizer (manufactured by Hiranuma Sangyo, product name "EV-6") and the Karl Fischer moisture meter (manufactured by Hiranuma Sangyo, product name "AQ-300") Was measured using. Specifically, 0.5 g of a zinc catalyst was weighed and introduced into a moisture vaporizer, and the vaporized moisture was introduced into a Karl Fischer moisture meter. The water content in the zinc catalyst was calculated by subtracting the measured value (blank measured value) in which only the cell was introduced into the water vaporizer.

Moisture meter analysis conditions / generated liquid: "Hydranal Coulomat AK" manufactured by Sigma-Aldrich
・ Counter electrode: Sigma-Aldrich "Hydranal Coulomat CG-K"
・ Moisture vaporizer temperature: 120 ℃
・ Wait time: 5 minutes ・ Analysis time: 30 minutes

<Measurement of molecular weight of polyalkylene carbonate>
The weight average molecular weight of the polyalkylene carbonate described in each Example and Production Example was measured under the following conditions using a gel permeation chromatograph measuring device (manufactured by Waters, product name "waters2695" separation module). It is the converted weight average molecular weight. The sample was introduced into the measuring device as an N, N-dimethylformamide solution having a polymer concentration of 0.3% by mass.

GPC measurement conditions-Column: Showa Denko's "Shodex OHpak SB-804 HQ" and "Shodex OHpak SB-805" connected in sequence-Column temperature: 40 ° C
・ Developing solvent: 5 mmol / L LiBr-N, N-dimethylformamide solution ・ Flow rate: 1.0 mL / min
・ Detector: Differential refractometer ・ Standard sample: Polystyrene

[Example 1] Production of organozinc catalyst 81 g (1.00 mol) of zinc oxide, 132 g (1.00 mol) of glutaric acid, 1000 g of toluene in a 1.5 L volume separable flask equipped with a cooling tube / thermometer and a stirrer. Was prepared. Then, the temperature was raised to 60 ° C. under a nitrogen atmosphere, and the mixture was stirred and reacted at the same temperature for 8 hours. Then, the mixture was cooled to room temperature and suction filtered to obtain 310 g of a zinc catalyst (moisture content: 20000 ppm, hereinafter referred to as undried zinc catalyst).
By drying 50 g of this undried zinc catalyst at 90 ° C. and 7.5 mmHg for 1 hr, 30 g of a zinc catalyst having a water content of 1108 ppm was obtained.
Subsequently, after replacing the inside of the 1 L autoclave system equipped with a stirrer, a gas introduction pipe and a thermometer with a nitrogen atmosphere in advance, the above zinc catalyst 10 g (0.05 mol), ethyl acetate 500 g, and propylene oxide 58 g ( 1.00 mol) was charged. The temperature was raised to 60 ° C., carbon dioxide was filled until the inside of the reaction system became 1.0 MPa, and the polymerization reaction was carried out for 12 hours while replenishing the consumed carbon dioxide. Then, the autoclave was cooled and depressurized to obtain an ethyl acetate slurry of a white polymer. This was filtered and dried under reduced pressure to obtain 80 g of polypropylene carbonate (yield 78%, molecular weight Mw277000).

[Example 2]
By drying 50 g of the undried zinc catalyst of Example 1 at 90 ° C. and 7.5 mmHg for 2 hours, 29 g of a catalyst having a water content of 696 ppm was obtained. Using this catalyst, polymerization was carried out in the same manner as in Example 1 to obtain 84 g of polypropylene carbonate (yield 82%, molecular weight Mw261000).

[Example 3]
By drying 50 g of the undried zinc catalyst of Example 1 at 90 ° C. and 7.5 mmHg for 4 hours, 30 g of the catalyst having a water content of 513 ppm was obtained. Using this catalyst, polymerization was carried out in the same manner as in Example 1 to obtain 86 g of polypropylene carbonate (yield 84%, molecular weight Mw251000).

[Example 4]
By drying 50 g of the undried zinc catalyst of Example 1 at 90 ° C. and 7.5 mmHg for 8 hours, 29 g of a catalyst having a water content of 408 ppm was obtained. Using this catalyst, polymerization was carried out in the same manner as in Example 1 to obtain 88 g of polypropylene carbonate (yield 86%, molecular weight Mw248000).

[Example 5]
By drying 50 g of the undried zinc catalyst of Example 1 at 70 ° C. and 7.5 mmHg for 4 hours, 30 g of a catalyst having a water content of 1600 ppm was obtained. Using this catalyst, polymerization was carried out in the same manner as in Example 1 to obtain 83 g of polypropylene carbonate (yield 81%, molecular weight Mw312000).

[Example 6]
By drying 50 g of the undried zinc catalyst of Example 1 at 120 ° C. and 7.5 mmHg for 4 hours, 29 g of the catalyst having a water content of 71 ppm was obtained. Using this catalyst, polymerization was carried out in the same manner as in Example 1 to obtain 83 g of polypropylene carbonate (yield 81%, molecular weight Mw220,000).

The results of the polymerization carried out in Examples 1 to 6 (zinc catalyst water content, polypropylene carbonate molecular weight, and polypropylene carbonate yield) are summarized in Table 1 below. The polymers in Table 1 are polypropylene carbonates. The relationship between the water content of the organozinc catalyst and the molecular weight of polypropylene carbonate is shown in FIG. 1 as a graph.

From the results, it was found that the higher the water content contained in the catalyst, the higher the molecular weight of the polymer. Normally, the higher the water content in the reaction system, the lower the molecular weight, but the opposite tendency was seen for the water incorporated in the catalyst. It was also found that by utilizing this, it is possible to control the molecular weight of the polymer at the time of polymerization by controlling the water content of the catalyst.

Claims (9)

An organozinc catalyst obtained by reacting a zinc compound and an aliphatic carboxylic acid.
Moisture content is 10 to 10000 ppm,
Organozinc catalyst. The organozinc catalyst according to claim 1, which is obtained by reacting a zinc compound with an aliphatic dicarboxylic acid. The organozinc catalyst according to claim 1, which is obtained by reacting a zinc compound, an aliphatic dicarboxylic acid, and an aliphatic monocarboxylic acid. The organozinc catalyst according to claim 2 or 3, wherein the aliphatic dicarboxylic acid is an aliphatic dicarboxylic acid having 2 to 15 carbon atoms. The aliphatic dicarboxylic acid is an aliphatic dicarboxylic acid having 2 to 15 carbon atoms.
The aliphatic monocarboxylic acid is an aliphatic monocarboxylic acid having 1 to 15 carbon atoms.
The organozinc catalyst according to claim 3. The organozinc catalyst according to any one of claims 1 to 5, wherein the zinc compound is zinc oxide and / or zinc hydroxide. The organozinc catalyst according to claim 1, which is obtained by reacting at least zinc oxide and glutaric acid. The organozinc catalyst according to any one of claims 1 to 7, for catalyzing a reaction for obtaining a polyalkylene carbonate from carbon dioxide and an epoxide. The present invention comprises reacting carbon dioxide with an epoxide in the presence of the organozinc catalyst according to any one of claims 1 to 8 to produce a polyalkylene carbonate.
A method for controlling the molecular weight of the produced polyalkylene carbonate using the water content of the organozinc catalyst used as an index.

Images