KR100612957B1 - Method for the preparation of alkylene carbonate using the catalytic system comprising of metal halide and alicyclic ammonium halide - Google Patents

Abstract

The present invention relates to a method for producing an alkylene carbonate using a catalyst system composed of a metal salt and an alicyclic amine salt, and more particularly, zinc (A) as a reaction catalyst in preparing an alkylene carbonate by reacting an alkylene oxide with carbon dioxide. Zn), a catalyst system consisting of a salt of a metal selected from iron (Fe), manganese (Mn), lead (Pb) and indium (In), and a salt of an alicyclic amine selected from pyrrolidine, piperidine and morpholine The present invention relates to a method for producing alkylene carbonate in a high yield within a short time at a lower pressure and temperature conditions compared to the conventional production method using.

Alkylene carbonate, alkylene oxide, carbon dioxide, metal salt, alicyclic amine salt

Description

Method for the preparation of alkylene carbonate using the catalytic system comprising of metal halide and alicyclic ammonium halide}

The present invention relates to a method for producing an alkylene carbonate using a catalyst system composed of a metal salt and an alicyclic amine salt, and more particularly, zinc (A) as a reaction catalyst in preparing an alkylene carbonate by reacting an alkylene oxide with carbon dioxide. Zn), a catalyst system consisting of a salt of a metal selected from iron (Fe), manganese (Mn), lead (Pb) and indium (In), and a salt of an alicyclic amine selected from pyrrolidine, piperidine and morpholine The present invention relates to a method for producing alkylene carbonate in a high yield within a short time at a lower pressure and temperature conditions compared to the conventional production method using.

Alkylene carbonates are not only used as raw materials for polycarbonates, intermediates in pharmaceutical processes, oxyalkylation agents for dyestuff synthesis processes, process equipment protection agents, solvents for fiber production processes, etc. The range of use, such as the solvent of an electrolyte, is expanding day by day. In addition, recently developed new process for producing ethylene glycol has been improved to the process of synthesizing ethylene oxide via ethylene carbonate without directly reacting with water, and the interest in ethylene carbonate synthesis is increasing.

In general, alkylene carbonate is prepared by reacting alkylene oxide and carbon dioxide in the presence of a catalyst, as shown in Scheme 1 below.

In Reaction Scheme 1, R ^a and R ^b are the same as or different from each other and are selected from a hydrogen atom, an alkyl group having ₁ to ₄ carbon atoms, and a phenyl group.

In the above reaction, in order to obtain an industrially useful reaction rate, high temperature and high pressure conditions are required, but under high temperature and high pressure conditions, a raw material alkylene oxide tends to decompose or polymerize. Therefore, various kinds of materials have been developed as catalysts to further mitigate the reaction conditions.

As such a catalyst, there is a method of using an inorganic salt, a phosphonium halide and an ammonium halide-based compound as a catalyst [Japanese Patent Laid-Open No. 9-67365, Japanese Patent Laid-Open No. 59-13776, Japanese Patent Laid-Open No. 9-235252 And US Pat. No. 2,773,070 and the like. Japanese Patent Laid-Open No. 9-67365 discloses a method of using potassium iodide (KI) as a catalyst, and Japanese Patent Laid-Open No. 59-13776 discloses a tetraalkylphosphonium halide such as tributylmethylphosphonium iodide. Discloses a method of using as a catalyst. In addition, Japanese Patent Laid-Open No. 9-235252 discloses a method of using a polystyrene copolymer having a quaternary phosphonium halide bonded to a polymer terminal as a catalyst. The above-mentioned known technique states that a yield of 50 to 95% is obtained when reacting at a reaction temperature of 100 to 170 ° C. for 1 to 5 hours, but a high temperature and a long reaction time are required to obtain a high yield. There is a problem in that the moisture content of carbon dioxide and alkylene oxide, which is a substance, has to be adjusted to several hundred ppm or less.

In addition, Japanese Patent Application Laid-open No. Hei 7-206846 discloses a method using a catalyst in which an ion exchange resin is substituted with cesium hydroxide (CsOH), rubidium hydroxide (RbOH), and an ammonium halide. Patent No. 4,233,221 discloses a method of using an ion exchange resin of DOWEX and Amberlite series, but the above methods have a problem in that yield and productivity are poor.

Further, in addition to the catalysts mentioned above, U.S. Patent No. 5,283,356 describes cobalt (Co), chromium (Cr), iron (Fe), manganese (Mn), nickel (Ni), titanium (Ti), vanadium (V) and zirconium. A method of using phthalocyanin including (Zr) as a catalyst is disclosed, and Japanese Patent Laid-Open No. Hei 7-206547 discloses rubidium (Rb) or cesium (Cs) ions instead of hydrogen ions of heteropoly acid. A method of using a catalyst system in which is substituted is disclosed. Both of these methods require expensive catalysts, and the reaction temperature is not only high at 120 to 180 ° C but also low at 30 to 90%.

As described above, the known production method of alkylene carbonate requires a high temperature in order to industrially produce, not only the reaction conditions such as moisture removal of raw materials are difficult, but also the selectivity and yield are low, and the reaction time is long. .

On the other hand, the present inventors have also studied to develop a new reaction catalyst which does not require the water removal process of the raw material and enables the industrial mass production of alkylene carbonate with high yield in a short time under milder temperature and pressure conditions. As a result, an imidazolium zinc halide complex compound formed by complexing imidazolium halide and zinc halide in a 2: 1 molar ratio was prepared, and this complex compound was used as a catalyst for the synthesis of alkylene carbonate from alkylene oxide and carbon dioxide. The technology has also been applied for a patent [Korean Patent Application No. 2002-86949].

The present invention has been obtained as a result of continued research after the invention of the above-mentioned Korean Patent Application No. 02-86949, and a metal selected from zinc (Zn), iron (Fe), manganese (Mn), lead (Pb) and indium (In). When a salt mixture in which a salt of and a salt of an alicyclic amine selected from pyrrolidine, piperidine and morpholine has a predetermined content ratio is used as a reaction catalyst in the process of preparing an alkylene carbonate, a milder reaction than the conventional method The present invention has been completed by knowing that alkylene carbonate can be produced in high yield in a short time under conditions.

Accordingly, an object of the present invention is to provide a method for producing alkylene carbonate using a catalyst system composed of a specific metal salt and an alicyclic amine salt.

The present invention provides a method for producing alkylene carbonate by reacting an alkylene oxide and carbon dioxide under a catalyst,

The catalyst includes a salt of a metal selected from zinc (Zn), iron (Fe), manganese (Mn), lead (Pb), and indium (In), and an alicyclic amine selected from pyrrolidine, piperidine, and morpholine. It is characterized by using a catalyst system composed of a salt of.

Referring to the present invention in more detail as follows.

The present invention relates to a novel catalyst system applied to a reaction for producing alkylene carbonate by reacting alkylene oxide with carbon dioxide. The catalyst system of the present invention is a salt of a metal selected from zinc (Zn), iron (Fe), manganese (Mn), lead (Pb) and indium (In), and an aliphatic cyclic type selected from pyrrolidine, piperidine, and morpholine. It consists of a salt of an amine. When the catalyst system of the present invention is applied to the reaction of alkylene oxide and carbon dioxide, there is no need to perform the water removal process of the raw materials separately, and a fast time even under mild reaction conditions (60 to 150 ℃ and 10 to 100 atm conditions) Alkylene carbonates can be prepared in excellent yields.

In particular, the present invention has the advantage that the alkylene carbonate can be synthesized by reacting the alkylene oxide and carbon dioxide in the presence of a small amount of the metal catalyst. During the vacuum distillation process necessary during the purification of the alkylene carbonate, the metal catalyst remaining in the reactant decomposes the alkylene carbonate as shown in Scheme 2 below. Therefore, when preparing alkylene carbonate from alkylene oxide and carbon dioxide, it is important to use as little metal catalyst as possible to separate and purify the alkylene carbonate as a product after the reaction. For this reason, the present study shows that the catalyst system composed of aliphatic amine salts to metal salts has a very effective catalytic performance, while at the same time conducting a study on a catalyst system with a small amount of metal catalyst while maintaining the catalyst performance. It was found that the yield of alkylene carbonate increased significantly with increasing. That is, when using the catalyst of the present invention in the catalyst system of the same performance, it is possible to greatly reduce the relative molar ratio of the metal salt present, and consequently to greatly suppress the reaction of the decomposition of alkylene carbonate during the purification of the product alkylene carbonate. Can be.

Specific examples of the reaction that can be made in the catalyst system of the present invention consisting of a metal salt and an alicyclic amine salt are shown in the following Scheme 3.

In Scheme 3, R ₁ And R ₂ is the same or different and is selected from a C _1-18 chain or branched alkyl group, C _6-12 aryl group and C _7-12 aralkyl group; X ⁻ represents a halogen anion; M is a metal atom selected from Zn, Fe, Mn, Pb, In; z and m are integers 1-3, respectively.

According to Scheme 3, the catalyst system of the present invention is a kind of 'aliphatic amine metal salt catalyst', which has the characteristics of Lewis base and Lewis acid of an ionic liquid at the same time in the reaction of alkylene oxide and carbon dioxide. It is judged to exhibit high catalytic activity.

Hereinafter, the method for preparing alkylene carbonate using the catalyst system of the present invention will be described in detail.

Alkylene oxide and carbon dioxide used as raw materials in the production method according to the present invention may be used as a high-purity material, even if it contains nitrogen, hydrogen, carbon monoxide, low concentration of hydrocarbons and water, etc. does not significantly affect the reaction. Therefore, industrially produced carbon dioxide and alkylene oxide may be used as it is without further purification.

The catalyst applied to the production method of the present invention uses a catalyst system composed of a metal salt and an alicyclic amine salt. At this time, the molar ratio of [aliphatic cyclic amine salt] / [metal salt] is used in the range of 1 to 10. When the molar ratio is less than 1, the reaction rate is too slow, and when the molar ratio exceeds 10, further reaction rate is increased. There is no economic benefit because it does not increase. Metal salts and alicyclic amine salts used to construct the catalyst system of the present invention are precursor materials capable of providing metal cations and alicyclic ammonium cations, and are generally used in the field of catalyst production such as nitrates, acetates, and halides. The compound may be applied, but in terms of catalytic activity, it is preferable to use a salt compound in the form of a halide as a precursor material, and particularly preferably use a salt compound in the form of a chloride as a precursor material. The aliphatic cyclic amine salt is an aliphatic heterocyclic compound containing a nitrogen atom, specifically, a pyrrolidinium halide represented by the following Chemical Formula 1a, a piperidinium halide represented by the following Chemical Formula 1b, and a morpholinium represented by the following Chemical Formula 1c. Halides and the like.

In the above, R ₁ And R ₂ is the same or different and is selected from a C _1-18 chain or branched alkyl group, C _6-12 aryl group and C _7-12 aralkyl group; X ⁻ represents a halogen anion.

In addition, the molar ratio of [alkylene oxide] / [metal salt] is preferably used in the range of 100 to 20,000 in carrying out the preparation method of the present invention. When the molar ratio is less than 100, the reaction rate is too fast to generate a lot of by-products. In addition, there is a problem that the productivity is greatly reduced, and when the molar ratio exceeds 20,000, the reaction rate is remarkably slowed so that the productivity is no longer improved.

In the production reaction of the alkylene carbonate according to the present invention using the catalyst system, the alkylene carbonate may be produced in excellent yield even under the reaction temperature of 60 to 150 ° C. and the reaction pressure of 10 to 100 atm. If the reaction temperature is kept lower than 60 ℃ is not preferable because the reaction rate is significantly slow, maintaining the high temperature above 150 ℃ reaction rate is increased but the alkylene oxide used as a raw material is decomposed or There is a problem that the reaction selectivity is greatly lowered by causing self-polymerization reaction. The reaction pressure does not significantly affect the reaction rate and yield, but it is generally preferred to proceed at 10 to 100 atm. If the reaction pressure is less than 10 atm, there is a problem in the safety of the reaction, in the case of exceeding 100 atm, the effect of increasing the reaction speed is insignificant, but there is a problem in that the economic cost of maintaining and installing the equipment is excessively required.

The reaction of preparing the alkylene carbonate is mainly performed in the absence of a solvent, but a solvent may be used to prevent rapid exotherm during the reaction. The solvent is preferably an alkylene carbonate produced from the alkylene oxide used as a raw material, but is not necessarily limited thereto. For example, when synthesizing ethylene carbonate from ethylene oxide, ethylene carbonate is used as a solvent, and when propylene carbonate is synthesized from propylene oxide, propylene carbonate is more preferably used as a solvent. It is irrelevant to use.

In addition, the process may be both a batch process using a reactor equipped with a stirrer and a continuous process using a bubble column (bubble column).

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the present invention is not limited by the following examples.

Example 1

Ethylene oxide (33.0 g, 750 mmol), ZnBr ₂ (0.075 mmol), 1,1-dimethylpyrrolidinium chloride (0.30 mmol), which were reactants, were charged to a 200 mL high-pressure reactor, and 10 atm of carbon dioxide was charged. The temperature was raised to 100 ° C. and carbon dioxide was added again to 30 atm, and the reactor was continuously supplied with the amount of carbon dioxide consumed during the reaction to maintain the reactor pressure at 30 atm. After reacting at 100 ° C. for 1 hour, the reactor was cooled to room temperature, volatiles were removed using nitrogen, and the solid product was separated and then analyzed by gas-liquid chromatography. As a result, ethylene carbonate was produced with a yield of 60.7%, and TOF (h ⁻¹ ) was 6,070.

Yield and TOF (h ^-1 ) values were calculated using the following equations ( ¹ ) and (2).

Examples 2 to 8

Table 1 shows the results of experiments varying the types of metal chlorides and alicyclic amine salts under the same conditions as in Example 1. At this time, the molar ratio of [aliphatic cyclic amine salt] / [metal chloride] was maintained at 4/1.

Example Metal salt Alicyclic amine salt yield(%) TOF (h ^-1 ) 2 ZnCl ₂ 1-propyl-1-butylpyrrolidinium bromide 61.5 6,150 3 ZnI ₂ 1-ethyl-1-phenylpiperidinium chloride 55.6 5,560 4 FeCl ₃ 1-ethyl-1-hexylpiperidinium bromide 39.1 3,910 5 MnCl ₃ 1-ethyl-1-butylpiperidinium iodide 31.0 3,100 6 PbCl ₂ 1-propyl-1-benzylmorpholinium bromide 30.3 3,030 7 PbBr ₂ 1,1-dimethylpyrrolidinium chloride 32.7 3,270 8 InCl ₃ 1,1-dimethylpyrrolidinium bromide 38.2 3,820

Examples 9-17

Fixing the amount of the raw material ethylene oxide under the same conditions as in Example 1 with 33.60 g (764 mmol), and indicate the result of 1,1-dimethyl-pyrrolidin experiment while changing the mole ratio of pyridinium hydrochloride / ZnBr ₂ in Table 2 It was.

Example Aliphatic cyclic amine salt / metal salt (molar ratio) Ethylene Oxide / Metal Salt (Molar Ratio) yield(%) TOF (h ^-1 ) 10 One 10,000 11.7 1,170 11 2 10,000 31.9 3,195 12 5 10,000 84.5 8,450 13 10 10,000 96.7 9,670 14 4 20,000 16.7 1,670 15 4 1,000 99.7 997 16 4 100 99.5 99

Examples 17-20

Performed under the same conditions as in Example 1, but used as a catalyst in which the molar ratio of 1,1-dimethylpyrrolidinium chloride and ZnBr ₂ is 4: 1, and fixed the molar ratio of [ethylene oxide] / [metal chloride] to 10,000 It was. However, the results of the experiment while changing the reaction temperature are shown in Table 3 below.

Example Reaction temperature (℃) yield(%) TOF (h ^-1 ) 17 80 29.6 2,960 18 100 58.9 5,890 19 120 80.3 8,030 20 150 97.1 9,710

Examples 21-24

Performed under the same conditions as in Example 1, but used as a catalyst in which the molar ratio of 1,1-dimethylpyrrolidinium chloride and ZnBr ₂ is 4: 1, the molar ratio of [ethylene oxide] / [metal chloride] is 10,000 Fixed with. However, the results of the reaction experiment while changing the pressure of CO ₂ are shown in Table 4 below.

Example Reaction pressure (atm) yield(%) TOF (h ^-1 ) 21 100 59.0 5,900 22 70 53.3 5,330 23 50 52.2 5,220 24 10 53.7 5,370

Examples 25-27

Under the same conditions as in Example 1, the molar ratio of 1,1-dimethylpyrrolidinium chloride and ZnBr ₂ was 4: 1, and the molar ratio of [alkylene oxide] / [metal chloride] was fixed at 4,000. However, the results of the reaction experiment while changing the type of alkylene oxide are shown in Table 5 below.

Example Alkylene oxide yield(%) TOF (h ^-1 ) 25 Propylene oxide 86.3 3,452 26 2,3-epoxybutane 55.0 2,328 27 Styrene oxide 67.2 2,772

Examples 28-29: Effect of preparing alkylene carbonate according to the change of solvent

Under the same conditions as in Example 1, a molar ratio of 1,1-dimethylpyrrolidinium chloride and ZnBr ₂ was used as a 4: 1 catalyst, and the molar ratio of [alkylene oxide] / [metal chloride] was fixed at 5,000. Ethylene oxide and CO ₂ were reacted for 3 hours. In this case, 100% of ethylene carbonate or propylene carbonate was used as the solvent by weight ratio with respect to the raw material ethylene oxide, and the results of the experiment are shown in Table 6 below.

Example menstruum yield(%) TOF (h ^-1 ) 28 Ethylene carbonate 91.7 1,528 20 Propylene carbonate 90.3 1,505

Comparative Example 1: KI / ZnBr ₂  Ethylene Oxide Production

The activity of the catalyst prepared according to the above example was compared using KI / ZnBr ₂ in a 1: 1 molar ratio as a catalyst used in the preparation of alkylene carbonate.

The molar ratio of [ethylene oxide] / [Zn] was set to 5,000 and 3,000, and other conditions such as reaction temperature and pressure were set in the same manner as in Example 1 to proceed with the reaction of ethylene oxide and CO ₂ . As a result, when the molar ratio of [ethylene oxide] / [Zn] was 5,000, the reaction hardly proceeded, and when the molar ratio of [ethylene oxide] / [Zn] was adjusted to 3,000, the TOF (h- ¹ ) value was obtained. Was 796.

Comparative Example 2: Preparation of Ethylene Oxide Using Metal Salt or Alicyclic Cycloamine

Under the same conditions as in Example 1, the molar ratio of [ethylene oxide] / [catalyst] is 1,000, and a metal salt or an alicyclic amine salt is used alone as a catalyst. The results of the reaction of ethylene oxide and CO ₂ are shown in Table 7 below.

catalyst yield(%) TOF (h ^-1 ) ZnCl ₂ 3.0 30 FeBr ₃ 0.5 5 MnCl ₂ 1.2 12 InCl ₂ 0.8 8 1,1-dimethylpyrrolidinium chloride 0.5 5 1-propyl-1-butylpyrrolidinium bromide 2.5 25 1-ethyl-1-butylpiperidinium iodide 3.4 34 1-propyl-1-benzylmorpholinium bromide 1.6 16

As described above, by using the catalyst system composed of a metal salt and an alicyclic amine salt according to the present invention, it is possible to synthesize alkylene carbonate from alkylene oxide and carbon dioxide in high yield in a short time under low temperature and low pressure conditions. It can be seen.

Claims (9)

In the method for producing an alkylene carbonate by reacting alkylene oxide and carbon dioxide under a catalyst, the catalyst as A salt of a metal selected from zinc (Zn), iron (Fe), manganese (Mn), lead (Pb), and indium (In), pyrrolidinium halides represented by the following formula (1a), and piperididies represented by the following formula (1b) Method for producing an alkylene carbonate, characterized by using a catalyst system consisting of a salt of an aliphatic amine selected from nium halides and morpholinium halides represented by the following formula (1c):

In Formula 1a, 1b and 1c, R ₁ And R ₂ is the same or different and is selected from a C _1-18 chain or branched alkyl group, C _6-12 aryl group and C _7-12 aralkyl group; X ⁻ represents a halogen anion. The method for producing alkylene carbonate according to claim 1, wherein the molar ratio of [aliphatic cyclic amine salt] / [metal salt] is 1 to 10. The method for producing alkylene carbonate according to claim 1, wherein the molar ratio of [alkylene oxide] / [metal salt] is 100 to 20,000. The method of claim 1, wherein the reaction is carried out at a temperature of 60 to 150 ℃ and pressure conditions of 10 to 100 atm. The method of claim 1 or 4, wherein the reaction is performed in the presence of a solvent or in a solvent-free condition. The method of claim 5, wherein the solvent is ethylene carbonate or propylene carbonate. The method for producing alkylene carbonate according to claim 1, 2 or 3, wherein the metal salt is a metal halide. delete The method of claim 1, wherein the alkylene carbonate is represented by the following formula (2):

In Formula 2, R ^a and R ^b are the same as or different from each other and are selected from a hydrogen atom, an alkyl group having ₁ to ₄ carbon atoms, and a phenyl group.