JP7488472B2 - Method for Producing Z-1,2-Dichloro-3,3,3-Trifluoropropene - Google Patents

Description

The present invention relates to a method for producing (Z)-1,2-dichloro-3,3,3-trifluoropropene (HCFO-1223xd(Z)).

1,2-dichloro-3,3,3-trifluoropropene (HCFO-1223xd), a type of hydrochlorofluoroolefin (HCFO), is expected to be used as a solvent, cleaning agent, refrigerant, etc. as a substitute for hydrofluorocarbons (HFCs) (for example, Patent Documents 1 to 8). 1,2-dichloro-3,3,3-trifluoropropene (HCFO-1223xd) has trans (E) and cis (Z) geometric isomers (hereinafter, these may be referred to as HCFO-1223xd(E) and HCFO-1223xd(Z), respectively). Different geometric isomers may be more suitable for different applications. For example, high-purity HCFO-1223xd(Z) is expected to be suitable for certain refrigerant applications.

Japanese Patent Application Laid-Open No. 2-221388 Japanese Patent Application Laid-Open No. 2-221389 Japanese Patent Application Laid-Open No. 2-221962 Japanese Patent Application Laid-Open No. 2-222469 Japanese Patent Application Laid-Open No. 2-222496 Japanese Patent Application Laid-Open No. 2-222497 Japanese Patent Application Laid-Open No. 2-222702 JP 2013-87187 A

As disclosed in Japanese Patent Application No. 2018-141359 by the present applicant, it has been found that (Z)-1,2-dichloro-3,3,3-trifluoropropene (HCFO-1223xd(Z)) and 1,1-dichloro-3,3,3-trifluoropropene (HCFO-1223za) form an azeotrope-like composition. This azeotrope-like composition is useful for various applications. However, once an azeotrope-like composition is formed, it is difficult to separate the components that make up the azeotrope-like composition. Apart from the usefulness of the azeotrope-like composition itself, high-purity HCFO-1223xd(Z) may be required depending on the application. As one method for meeting this demand, a method for efficiently obtaining high-purity HCFO-1223xd(Z) from this azeotrope-like composition has been required.

The objective of the present invention is to provide a method for easily and inexpensively producing HCFO-1223xd(Z) having a reduced HCFO-1223za content from a composition containing (Z)-1,2-dichloro-3,3,3-trifluoropropene (HCFO-1223xd(Z)) and 1,1-dichloro-3,3,3-trifluoropropene (HCFO-1223za).

One embodiment of the present invention is a method for producing HCFO-1223xd(Z), comprising contacting a composition comprising 1223xd(Z) and 1,1-dichloro-3,3,3-trifluoropropene (HCFO-1223za) with a base to reduce the ratio of HCFO-1223za to HCFO-1223xd(Z) in the composition.

In the above method, the base may be at least one selected from a compound containing an alkali metal or an alkaline earth metal, ammonia, and an amine.

In the above method, the base may be at least one selected from an alkali metal alkoxide, an alkali metal carbonate, an alkali metal hydroxide, an alkaline earth metal carbonate, an alkaline earth metal hydroxide, an alkali metal carboxylate, and an alkaline earth metal carboxylate.

In the above method, contact with the base may be carried out at a temperature of 10°C to 60°C.

In the above method, the composition may contain at least one compound selected from trichlorotrifluoropropane (HCFC-233), tetrachlorotrifluoropropane (HCFC-223), pentachlorotrifluoropropane (CFC-213), monochlorotrifluoropropene (HCFO-1233), dichlorotrifluoropropene (HCFO-1223), trichlorotrifluoropropene (CFO-1213), 1-chloro-3,3,3-trifluoropropyne, hydrogen fluoride, hydrogen chloride, chlorine, and water.

According to the present invention, it is possible to easily and inexpensively produce HCFO-1223xd(Z) having a reduced HCFO-1223za content from a composition containing (Z)-1,2-dichloro-3,3,3-trifluoropropene (HCFO-1223xd(Z)) and 1,1-dichloro-3,3,3-trifluoropropene (HCFO-1223za).

Below, a method according to an embodiment of the present invention is described. However, the present invention can be implemented in various forms without departing from the gist of the invention, and should not be construed as being limited to the description of the embodiments exemplified below. Furthermore, even if there are other effects and advantages different from those brought about by the aspects of the following embodiments, those that are clear from the description in this specification or that can be easily predicted by a person skilled in the art are naturally considered to be brought about by the present invention.

In this embodiment, a method for producing (Z)-1,2-dichloro-3,3,3-trifluoropropene (hereinafter also referred to as "1223xd(Z)") (hereinafter also simply referred to as "this production method") is described.

This manufacturing method involves contacting a composition containing 1223xd(Z) and 1,1-dichloro-3,3,3-trifluoropropene (hereinafter also referred to as "1223za") with a base (hereinafter also referred to simply as "this contact"). This contact causes 1223za in the composition to react with the base and decompose. This makes it possible to reduce the ratio of 1223za to 1223xd(Z) in the composition. Although 1223xd(Z) can also react with base, the inventors of the present application have found that 1223za reacts preferentially with base.

(Composition containing 1223xd(Z) and 1223za)
In this manufacturing method, a composition containing 1223xd(Z) and 1223za is used. The content ratio of 1223xd(Z) and 1223za in this composition is not particularly limited. For example, the molar ratio of 1223xd(Z) and 1223za, expressed as 1223za/1223xd(Z), may be 0.0001 to 10000, 0.0001 to 1000, 0.0001 to 100, 0.0001 to 10, 0.0001 to 1, 0.0001 to 0.1, 0.0001 to 0.01, or 0.0001 to 0.001.

In addition, this composition may contain components other than 1223xd(Z) and 1223za. The total content ratio of 1223xd(Z) and 1223za in this composition is not particularly limited. When this composition contains components other than 1223xd(Z) and 1223za, for example, the total content ratio of 1223xd(Z) and 1223za in the composition may be 1% by mass or more, 10% by mass or more, 30% by mass or more, 50% by mass or more, more than 50% by mass, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, 98% by mass or more, or 99% by mass or more.

When this composition contains components other than 1223xd(Z) and 1223za, the components are not particularly limited, and examples thereof include raw materials and by-products used in the process of producing 1223xd(Z) and 1223za. Examples of components other than 1223xd(Z) and 1223za include trichlorotrifluoropropane (hereinafter also referred to as "HCFC-233"), tetrachlorotrifluoropropane (hereinafter also referred to as "HCFC-223"), pentachlorotrifluoropropane (hereinafter also referred to as "CFC-213"), monochlorotrifluoropropene (hereinafter also referred to as "HCFO-1233"), dichlorotrifluoropropene (hereinafter also referred to as "HCFO-1223"), trichlorotrifluoropropene (hereinafter also referred to as "CFO-1213"), 1-chloro-3,3,3-trifluoropropyne, hydrogen fluoride, hydrogen chloride, chlorine, water, etc.

Examples of HCFC-233 include 1,1,2-trichloro-3,3,3-trifluoropropane (HCFC-233da), 1,2,2-trichloro-3,3,3-trifluoropropane (HCFC-233ab), etc.

Examples of HCFC-223 include 1,1,2,2-tetrachloro-3,3,3-trifluoropropane (HCFC-223aa), 1,2,2,3-tetrachloro-1,3,3-trifluoropropane (HCFC-223ab), 1,1,1,2-tetrachloro-3,3,3-trifluoropropane (HCFC-223db), etc.

Examples of CFC-213 include 1,1,1,2,2-pentachloro-3,3,3-trifluoropropane (CFC-213ab), 1,1,2,2,3-pentachloro-1,3,3-trifluoropropane (CFC-213aa), etc.

Examples of HCFO-1233 include (E)-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd(E)), (Z)-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd(Z)), 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf), (E)-1-chloro-2,3,3-trifluoro-1-propene (HCFO-1233yd(E)), (Z)-1-chloro-2,3,3-trifluoro-1-propene (HCFO-1233yd(Z)), etc.

HCFO-1223 includes dichlorotrifluoropropenes other than 1223xd(Z) and 1223za, such as (E)-1,2-dichloro-3,3,3-trifluoropropene (HCFO-1223xd(E)).

Examples of CFO-1213 include 1,1,2-trichloro-3,3,3-trifluoropropene (CFO-1213xa).

(base)
The base used in the present production method is preferably at least one selected from compounds containing alkali metals or alkaline earth metals, ammonia, and amines, where alkali metals refer to lithium, sodium, potassium, rubidium, or cesium, and alkaline earth metals refer to magnesium, calcium, or strontium.

Examples of compounds containing alkali metals or alkaline earth metals include alkali metal alkoxides, alkali metal carbonates, alkaline earth metal carbonates, alkali metal hydrogen carbonates, alkaline earth metal hydrogen carbonates, alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal carboxylates, and alkaline earth metal carboxylates.

As the amine, for example, a primary amine represented by the general formula R ¹ -NH ₂ , a non-cyclic secondary amine represented by the general formula R ² (R ³ ) -NH, or a cyclic amine can be used, where R ¹ , R ² , and R ³ are each independently an alkyl group, an aryl group, or an alicyclic hydrocarbon group.

The base may, for example, be a compound selected from the following group:
alkali metal alkoxides such as sodium methoxide and sodium ethoxide; alkali metal carbonates such as sodium carbonate, potassium carbonate, lithium carbonate and calcium carbonate; alkali metal hydrogen carbonates such as sodium hydrogen carbonate, potassium hydrogen carbonate and lithium hydrogen carbonate; alkali metal hydroxides such as potassium hydroxide, sodium hydroxide and calcium hydroxide; alkaline earth metal hydroxides such as magnesium hydroxide; alkali metal carboxylates such as sodium acetate and potassium acetate; lower alkylamines such as methylamine, ethylamine and propylamine, Aromatic amines such as aniline and toluidine; di-lower alkylamines such as dimethylamine, diethylamine and dipropylamine, aromatic secondary amines such as N-methylaniline and N-methyltoluidine; cyclic amines such as pyrrolidine, piperidine, piperazine, morpholine, quinuclidine, 1,4-diazabicyclo[2.2.2]octane (DABCO), pyrrole, pyrazole, imidazole, pyridine, pyridazine, pyrimidine, pyrazine, oxazole, thiazole, lutidine, diazabicycloundecene (DBU), diazabicyclononene (DBN), etc.

From the standpoint of economy and ease of handling, the base is preferably an alkali metal carbonate, an alkaline earth metal carbonate, an alkali metal hydroxide, or an alkaline earth metal hydroxide, and more preferably an alkali metal hydroxide.

The amount of base used in this contact is at least 1 equivalent per equivalent of 1223za, but one may be used in excess of the other. In one embodiment, the amount of base used is preferably in excess of 1223za, for example, more than 1 equivalent and up to 100 equivalents, more than 1 equivalent and up to 60 equivalents, or more than 1 equivalent and up to 40 equivalents per equivalent of 1223za.

(solvent)
The contact may be carried out in the presence of a solvent. Examples of the solvent include alkanes such as pentane, hexane, heptane, and octane; aromatic hydrocarbons such as benzene, toluene, and xylene; ethers such as diethyl ether, tetrahydrofuran, and dioxane; halogenated hydrocarbons such as dichloromethane and chloroform; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; nitriles such as acetonitrile, propionitrile, and butylnitrile; amides such as N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAC), and hexamethylphosphoric triamide (HMPA); glycols such as ethylene glycol, diethylene glycol, ethylene glycol monomethyl ether, and ethylene glycol monoacetate; and water. The solvent may be used alone or in combination of two or more.

The contact may be carried out in the presence of additives such as a compatibilizer or a phase transfer catalyst. Examples of the compatibilizer include alcohols such as methanol, ethanol, and propanol. Examples of the phase transfer catalyst include crown ethers, cryptands, and onium salts.

The contact may also be carried out in the presence of both a solvent and an additive.

(Contact method)
In this contact, the composition containing 1223xd(Z) and 1223za may be in a gaseous or liquid state, and the base may be in any state of gas, liquid, or solid. This contact is preferably liquid-liquid contact or gas-liquid contact. When the base is a solid, it may be used in the form of a solution using the above-mentioned solvent for contact with the composition containing 1223xd(Z) and 1223za. The concentration of the solution is not particularly limited, but it is preferable that a person skilled in the art appropriately adjusts the concentration according to the type of base to such an extent that the reaction between 1223za and the base proceeds and the base dissolves in the solvent. For example, when an aqueous solution of an alkali metal hydroxide is used, the content of the alkali metal hydroxide in the aqueous solution is 0.5% by mass to 85% by mass, preferably 0.5% by mass to 50% by mass, more preferably 1% by mass to 40% by mass.

The pressure in this contact is not particularly limited, and it can be performed under normal pressure or pressurized conditions. For example, it can be performed at 0.1 MPa to 2 MPa (absolute pressure basis; the same applies below), or 0.1 MPa to 0.5 MPa.

The temperature during this contact is not particularly limited, but it is preferable to carry out this contact in a liquid-liquid state or a gas-liquid state. Depending on the pressure, it can be carried out at, for example, -20°C to +60°C, preferably 10°C to 60°C.

This contact can be carried out continuously, semi-continuously, or batchwise. In this production method, there is no particular restriction on the material of the reaction vessel. For example, a reaction vessel made of general stainless steel, glass, or fluororesin, or made of a material lined with glass or fluororesin, etc., can be used.

The purification procedure after this contact is not particularly limited, and 1223xd(Z) can be purified, for example, by distillation, drying, etc.

By using this manufacturing method, the content of 1223za can be reduced from a composition containing 1223xd(Z) and 1223za, thereby producing high-purity 1223xd(Z).

Below, the embodiments of the present invention will be described in detail with reference to the examples, however, the embodiments of the present invention are not limited to the examples described below. In the examples described below, the "%" in the composition analysis value represents the area % of the composition obtained by measurement by gas chromatography (apparatus: GC-2010Plus (Shimadzu Corporation), detector: FID). In addition, the "1223za ratio" refers to the value obtained by dividing the 1223za area % in the composition by the 1223xd(Z) area %.

[Example 1]
5 g of a composition containing 98.33% 1223xd(Z) and 1.55% 1223za (ratio of 1223za = 0.0158) and 50 g of a 1 mass% aqueous potassium hydroxide solution (equivalent of potassium hydroxide to 1223za in the composition: 19) were placed in a 100 mL pressure vessel made of SUS316 equipped with a stirring blade coated with tetrafluoroethylene resin, and the mixture in the pressure vessel was stirred at 30 ° C. for 22 hours in a sealed state. After stirring, the pressure vessel was cooled and the organic layer was taken out. This organic layer was washed with 50 g of water and then analyzed by gas chromatography to calculate the ratio of 1223za to 1223xd(Z) in the composition after the contact reaction. The 1223za reduction rate [%] was calculated from the ratio of 1223za to 1223xd(Z) in the composition before the contact reaction and the ratio of 1223za after the contact reaction according to the following formula 1.
1223za reduction rate [%] = [(1223za ratio before contact reaction - 1223za ratio after contact reaction) / (1223za ratio before contact reaction)] × 100 ... (Equation 1)

[Example 2]
The same operation as in Example 1 was carried out except that 30 g of a composition containing 98.33% 1223xd(Z) and 1.55% 1223za (ratio of 1223za = 0.0158) and 30 g of a 10 mass% aqueous potassium hydroxide solution were used and stirred at 50°C, and the organic layer after stirring was washed with 30 g of water. The 1223za reduction rate [%] was calculated in the same manner as in Example 1.

[Example 3]
In a 100 mL three-neck flask, 5 g of a composition containing 98.33% 1223xd(Z) and 1.55% 1223za (ratio of 1223za = 0.0158) and 50 g of a 1 mass% aqueous potassium hydroxide solution were placed and stirred at 0 ° C. for 22 hours. After the reaction, the organic layer was taken out and washed with 50 g of water, and then the organic layer was analyzed by gas chromatography. The 1223za reduction rate [%] was calculated in the same manner as in Example 1.

The results of Examples 1 to 3 are shown in Tables 1 and 2. In Table 1, the numerical value in parentheses following the composition analysis value [%] of 1223za indicates the ratio of 1223za to 1223xd(Z), and the numerical value in parentheses following the composition analysis value [%] of others indicates the ratio of others (compounds (group) other than 1223xd(Z) and 1223za) to 1223xd(Z).

As shown in Table 2, it was confirmed that when a composition containing 1223xd(Z) and 1223za was contacted with a base, 1223za reacted with the base preferentially over 1223xd(Z). In particular, it was found that a high 1223za reduction rate was observed when the contact reaction temperature was 30°C or 50°C.

Furthermore, even if the same operation as in Example 2 is carried out except that a 10% sodium hydroxide aqueous solution (equivalent amount of sodium hydroxide relative to 1223za in the composition: 3) is used instead of a 10% by mass aqueous solution of potassium hydroxide, it is believed that a high 1223za reduction rate similar to that of Example 2 will be observed.

Claims (3)

mixing a composition containing (Z)-1,2-dichloro-3,3,3-trifluoropropene and 1,1-dichloro-3,3,3-trifluoropropene with a base, and stirring the mixture containing the composition and the base to reduce the ratio of 1,1-dichloro-3,3,3-trifluoropropene to (Z)-1,2-dichloro-3,3,3-trifluoropropene in the composition;
the base is an alkali metal hydroxide;
The method for producing (Z)-1,2-dichloro-3,3,3-trifluoropropene, wherein the mixed solution is stirred at a temperature of 10° C. to 60° C. 2. The method of claim 1 , wherein the alkali metal hydroxide is potassium hydroxide or sodium hydroxide. The method according to claim 1 or 2, wherein the composition contains at least one compound selected from trichlorotrifluoropropane, tetrachlorotrifluoropropane, pentachlorotrifluoropropane, monochlorotrifluoropropene, dichlorotrifluoropropene, trichlorotrifluoropropene, 1-chloro-3,3,3-trifluoropropyne, hydrogen fluoride, hydrogen chloride, chlorine, and water.