JP7765697B2 - Method for producing and recovering hydrochlorofluoroolefins - Google Patents

Description

This disclosure relates to a method for producing and recovering hydrochlorofluoroolefins.

Hydrochlorofluoroolefins (hereinafter sometimes referred to as HCFOs) are compounds with excellent environmental performance, including a short lifetime in the atmosphere and a low global warming potential. HCFOs are useful as solvents, cleaning agents, refrigerants, heat transfer media for heat pumps, and high-temperature working fluids. For this reason, development is underway to replace chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs).

HCFO is an excellent solvent and cleaning agent, and silicone-based lubricants are known as compounds that can be dissolved using HCFO. Silicone-based lubricants are ideal for use in medical equipment, such as syringe needles and cylinders, and medical tubing components. HCFO can be used as a solvent when applying silicone-based lubricants to these products, or as a cleaning agent when removing them from these products.

For example, Patent Document 1 discloses a lubricant solution in which HCFO is used as a solvent for a silicone-based lubricant, with the lubricant content being 0.01 to 50% by mass of the solution (100% by mass), and further containing 1 to 50% alcohols (based on the total 100% by mass of the HCFO and alcohols). In this case, the alcohol content is approximately 0.99 to 99.98% based on the total 100% of the lubricant and alcohol. Patent Document 2 also discloses a solvent composition containing HCFO and a specific solvent as a solvent composition with excellent cleaning and solubility properties for various oils, including silicone oils, and discloses Z-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd(Z)) and 1-chloro-2,3,3-trifluoro-1-propene (HCFO-1233yd) as the HCFO.

HCFO-1233zd(Z) is a solvent with excellent dissolving and cleaning capabilities, but is also expensive. Therefore, when used as a solvent or cleaning agent, a recovery process is carried out, such as condensing and recovering the solvent vapor, and HCFO-1233zd(Z) is known to be reused (Patent Documents 3 and 4).

Patent No. 6507943 Patent No. 6945259 Japanese Patent Application Laid-Open No. 2020-138166 Japanese Patent Application Laid-Open No. 2021-155711

When HCFOs are used as solvents or cleaning agents, separation from the HCFOs can be difficult depending on the dissolved compounds, and used solvents and cleaning agents that have undergone the recovery process may contain compounds other than HCFOs that are difficult to separate.When recovering HCFOs for reuse, it is preferable to recover HCFOs of an appropriate purity from the perspective of maintaining dissolving and cleaning performance, so there was room for consideration regarding the recovery process for HCFOs that contain compounds that are difficult to separate.
In particular, silicone oils may contain alcohol as a solvent together with the organic polysiloxane component to improve solubility, adjust the evaporation rate, etc. When a mixture containing both such an organic polysiloxane component and an alcohol is dissolved with HCFO, and the HCFO is recovered from the solution composition, the above-mentioned problems arise.

The inventors investigated methods for recovering highly pure HCFO from a solution composition in which an organic polysiloxane component and an alcohol are dissolved in HCFO. They found that while it is possible to separate the organic polysiloxane component from the HCFO, the boiling points of the HCFO and the alcohol are close, making complete separation difficult. Specifically, the inventors found that HCFOs with 3 to 5 carbon atoms and 1 to 3 chlorine atoms have similar boiling points to alcohols with 1 to 3 carbon atoms, and that monochlorotrifluoropropene and dichlorotrifluoropropene, which are HCFOs with 3 carbon atoms and 1 to 2 chlorine atoms, have similar boiling points to methanol, ethanol, 2-propanol, or 1-propanol, making complete separation particularly difficult.

Means for solving the above problems include the following embodiments.
[1]
a first vaporization step of vaporizing the hydrochlorofluoroolefin and the alcohol from a solution composition in which an organic polysiloxane component and an alcohol are dissolved in the hydrochlorofluoroolefin;
a first condensation step of condensing the vapor to form a condensate;
a first two-layer formation step of contacting the condensate with water to form two separate layers, an organic layer and an aqueous layer having the alcohol dissolved therein;
a first recovery step of recovering the organic layer.
[2]
The method for recovering organic polysiloxanes according to [1], wherein the organic polysiloxane component is silicone oil, the hydrochlorofluoroolefin is used as a cleaning agent, and the alcohol is one or more selected from the group consisting of methanol, ethanol, and 2-propanol.
[3]
The method for recovering HCFO according to [1], characterized in that the mass ratio of the hydrochlorofluoroolefin to the silicone oil is 99/1 to 50/50, and the content of the organosiloxane component and the alcohol is 50 mass% or less based on the total amount of the HCFO, the organosiloxane component, and the alcohol.
[4]
The recovery method according to [1], wherein the purity of the hydrochlorofluoroolefin contained in the organic layer is 95 GC% or more.
[5]
When the purity of the hydrochlorofluoroolefin contained in the organic layer is less than 95 GC% in terms of GC%,
a second vaporization step of heating the organic layer to produce a vapor containing hydrochlorofluoroolefin and alcohol;
a second condensation step of condensing the vapor to form a condensate;
a second two-layer formation step of contacting the condensate with water to form two separate layers, an organic layer and an aqueous layer containing the alcohol dissolved therein;
The recovery method according to [1], further comprising a second recovery step of recovering the organic layer.
[6]
The recovery method according to [1], further comprising a step of drying the organic layer recovered in the first recovery step to remove moisture from the organic layer.
[7]
The recovery method according to [1], characterized in that in the first condensation step, the vapor is cooled to 10°C or less.
[8]
The hydrochlorofluoroolefin is at least one of monochlorotrifluoropropene and dichlorotrifluoropropene,
The purification method according to [1], wherein the alcohol is at least one of methanol, ethanol, 2-propanol, and 1-propanol.

According to one embodiment of the present disclosure, HCFO can be used as a cleaning agent, etc., and its purity can be increased and recovered by treating a solution of HCFO containing impurities using a two-stage method that involves distillation and water.

FIG. 1 is a process diagram illustrating each step of an embodiment of the present disclosure.

Embodiments of the present disclosure are described below. However, this disclosure can be implemented in various forms without departing from the spirit of the disclosure, and should not be construed as being limited to the description of the embodiments exemplified below. Furthermore, even if there are other effects different from those achieved by the aspects of the following embodiments, those that are clear from the description in this specification or that would be easily predictable by a person skilled in the art are naturally considered to be achieved by the present disclosure.

In addition, in this disclosure, for halogenated hydrocarbons, the abbreviation for that compound is written in parentheses after the compound name, and this abbreviation is used in place of the compound name as needed. For compounds that have a double bond in the molecule and exist as trans (E) and cis (Z) isomers, the E and Z isomers are indicated by adding (E) and (Z) to the end of the compound abbreviation, respectively. Compounds without the (E) or (Z) notation at the end of their abbreviation indicate the E and/or Z isomer.

[Outline of collection method]
Hereinafter, the method for recovering a highly purified HCFO from a solution composition containing an HCFO, an organic polysiloxane component, and an alcohol according to this embodiment will be described with reference to FIG. 1.

This recovery method involves a two-stage process to separate the organic polysiloxane component and alcohol from a solution composition in which the organic polysiloxane component and alcohol are dissolved in HCFO.

(Solution Composition)
In this recovery method, the solution composition contains an HCFO (A), an organic polysiloxane component (B), and an alcohol (C). This solution composition may be a homogeneous solution, or a heterogeneous solution or suspension. The organic polysiloxane component in the solution composition may be dissolved, dispersed, solidified, aggregated, or precipitated in the hydrochlorofluoroolefin, and the solution composition in this recovery method may be in any form.

(HCFO(A))
Because HCFOs have double bonds between carbon atoms, they have a short lifetime in the atmosphere and low ozone depletion potential (ODP) and global warming potential (GWP). In this disclosure, "ozone depletion potential" is a value used to compare the intensity of ozone depletion, calculated by dividing the total ozone depletion per kg of each compound by the total ozone depletion per kg of trichlorofluoromethane. Furthermore, "global warming potential" is an index that expresses the effect of individual greenhouse gases on global warming relative to the effect of carbon dioxide, taking into account their duration.

In this recovery method, HCFOs with a carbon number of 3 to 5 and a chlorine atom number of 1 to 3 are preferred, with those with a carbon number of 3 and a chlorine atom number of 1 to 2 being particularly preferred. Specifically, monochlorotrifluoropropene, monochlorotetrafluoropropene, dichlorotrifluoropropene, trichlorotrifluoropropene, and monochloroheptafluoropentene are preferred, with monochlorotrifluoropropene, monochlorotetrafluoropropene, and dichlorotrifluoropropene being particularly preferred, and Z-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd(Z)), Z-1-chloro-2,3,3-trifluoro-1-propene (HCFO-1233yd(Z)), E-1-chloro-2,3,3-trifluoro-1-propene (HCFO-1233yd(E)), Z-1,2-dichloro-3,3,3-trifluoropropene (HCFO-1223xd(Z)), and E-1,2-dichloro-3,3,3-trifluoropropene (HCFO-1223xd(E)) being even more preferred. All of these HCFOs dry very quickly. Furthermore, because they maintain the same temperature when boiled and vaporized, they are unlikely to adversely affect parts that are easily affected by heat, such as resin parts attached to the products being cleaned or coated. Furthermore, they have no flash point, low surface tension and viscosity, and evaporate easily even at room temperature, making them excellent cleaning and coating solvents.

Specific examples of monochlorotrifluoropropene, monochlorotetrafluoropropene, dichlorotrifluoropropene, trichlorotrifluoropropene, and monochloroheptafluoropentene are shown below, but the HCFOs that can be used in the present recovery method are not limited to these.
Monochlorotrifluoropropenes: Z-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd(Z), boiling point is about 39°C), E-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd(E), boiling point is about 18°C), Z-1-chloro-2,3,3-trifluoro-1-propene (HCFO-1233yd(Z), boiling point is about 54°C), E-1-chloro-2,3,3-trifluoro-1-propene (HCFO-1233yd(E), boiling point is about 48°C), 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf, boiling point is about 15°C).
Monochlorotetrafluoropropenes: Z-1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd(Z). Boiling point is about 15°C), E-1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd(E). Boiling point is about 19°C), Z-2-chloro-1,3,3,3-tetrafluoropropene (HCFO-1224xe(Z). Boiling point is about 17°C), E-2-chloro-1,3,3,3-tetrafluoropropene (HCFO-1224xe(E). Boiling point is about 23°C).
Dichlorotrifluoropropenes: Z-1,2-dichloro-3,3,3-trifluoropropene (HCFO-1223xd(Z), boiling point is about 53°C), E-1,2-dichloro-3,3,3-trifluoropropene (HCFO-1223xd(E), boiling point is about 60°C), 1,1-dichloro-3,3,3-trifluoropropene (HCFO-1223za, boiling point is about 55°C).
Trichlorotrifluoropropene: 1,1,2-trichloro-3,3,3-trifluoropropene (HCFO-1213xa. Boiling point: about 88°C).
Monochloroheptafluoropentene: E-1-chloro-2,3,3,4,4,5,5-heptafluoro-1-pentene (HCFO-1437dycc(E). Boiling point is about 93°C), Z-1-chloro-2,3,3,4,4,5,5-heptafluoro-1-pentene (HCFO-1437dycc(Z). Boiling point is about 89°C).

In this disclosure, taking into consideration the efficiency of the vaporization process, the boiling point of HCFO is preferably 10°C or higher and 95°C or lower, and more preferably 15°C or higher and 65°C or lower.

In this disclosure, the boiling point of a compound is the boiling point at normal pressure unless otherwise specified. In this disclosure, normal pressure means 1.013×10 ⁵ Pa, and normal temperature means 25° C.

The HCFO may be any one of the HCFOs listed above, or may contain two or more HCFOs.

(Organopolysiloxane Component (B))
The organic polysiloxane component of the present disclosure is a polymeric compound containing siloxane bonds. The organic polysiloxane component has excellent heat resistance, weather resistance, chemical stability, and the like, and has lubricity due to its structure.

The organic polysiloxane component of the present disclosure may be silicone oil, silicone resin, silicone oligomer, or silicone powder. Specifically, the silicone oil may be straight silicone or modified silicone. The silicone oil may be silicone grease. The organic polysiloxane component of the present disclosure may be a component derived from a silicone-based lubricant. In particular, it may be a component derived from modified silicone. Modified silicone is a silicone oil in which various properties have been imparted by introducing organic groups into straight silicone, and modified silicones that have been imparted with lubricating properties are often used as lubricants.

Silicone-based lubricants refer to lubricants that contain silicone, and examples include silicone oil and silicone grease. Silicone oils include straight silicone, as well as modified silicones such as reactive silicone and non-reactive silicone.

More specifically, straight silicones include dimethyl silicone, methylphenyl silicone, and methylhydrogen silicone, which are bonded with methyl groups, phenyl groups, or hydrogen atoms as substituents. Reactive silicones include amino-modified, epoxy-modified, carboxy-modified, carbinol-modified, methacrylic-modified, phenol-modified, and heterofunctional group-modified silicones. Non-reactive silicones include polyether-modified, methylstyryl-modified, alkyl-modified, higher fatty acid ester-modified, specially hydrophilic modified, and fluorine-modified silicones. These silicones may be used alone or in combination of two or more.

Examples of silicone oils include those under the product names "Shin-Etsu Silicone KF-96," "Shin-Etsu Silicone KF-965," "Shin-Etsu Silicone KF-968," "Shin-Etsu Silicone KF-99," "Shin-Etsu Silicone KF-50," "Shin-Etsu Silicone KF-54," "Shin-Etsu Silicone HIVACF-4," "Shin-Etsu Silicone HIVACF-5," "Shin-Etsu Silicone KF-56A," and "Shin-Etsu Silicone KF-995" (all manufactured by Shin-Etsu Chemical Co., Ltd.), "SH200" (manufactured by Dow Corning Toray Co., Ltd.), and "MDX4-4159" (manufactured by Dow Corning).

Preferred silicone greases are those that use the various silicone oils listed above as a base oil, blended with thickeners such as metal soaps, and various additives. Examples include products under the names "Shin-Etsu Silicone G-30 Series," "Shin-Etsu Silicone G-40 Series," "Shin-Etsu Silicone FG-720 Series," "Shin-Etsu Silicone G-411," "Shin-Etsu Silicone G-501," "Shin-Etsu Silicone G-6500," "Shin-Etsu Silicone G-330," "Shin-Etsu Silicone G-340," "Shin-Etsu Silicone G-350," and "Shin-Etsu Silicone G-630" (all manufactured by Shin-Etsu Chemical Co., Ltd.), "Molycoat® SH33L," "Molycoat® 41," "Molycoat® 44," "Molycoat® 822M," "Molycoat® 111," "Molycoat® High Vacuum Grease," and "Molycoat® Thermal Diffusion Compound" (all manufactured by Dow Corning Toray Co., Ltd.).

The silicone oil, silicone resin, silicone oligomer, silicone powder, and silicone grease containing the organic polysiloxane component of the present disclosure may be of one type or two or more types.

The mass ratio of HCFO to one or more components selected from the group consisting of silicone oil, silicone resin, silicone oligomer, silicone powder, and silicone grease is preferably 99/1 to 50/50, and more preferably 99/1 to 90/10. The higher the mass ratio of HCFO, the easier it is to obtain HCFO of higher purity using the recovery method of the present disclosure.

(Alcohol (C))
An organic compound in which a hydroxy group is bonded to a hydrocarbon of a straight-chain, branched-chain, or cyclic structure. When removing alcohol by contact with water, alcohols having 1 to 3 carbon atoms are preferred because they are easily soluble in water from the viewpoint of water solubility. Specifically, methanol (boiling point: approximately 64.5°C), ethanol (boiling point: approximately 78.3°C), 2-propanol (boiling point: approximately 82.4°C), or 1-propanol (boiling point: approximately 97°C) are preferred. Depending on the physical properties of the coexisting compounds, such as the boiling point and solubility, the alcohols may form an azeotrope-like composition, making separation by distillation difficult.

In the solution composition of the present disclosure, the HCFO content may be from about 50% to about 99% by mass, or from about 70% to about 99% by mass, or from about 80% to about 99% by mass, based on the total amount of HCFO, organosiloxane component, and alcohol. When the HCFO content is within the above range, a highly pure HCFO can be obtained by the recovery method of the present disclosure.
In the solution composition of the present disclosure, the content of the organosiloxane component and the alcohol is preferably about 50% by mass or less, more preferably about 30% by mass or less, even more preferably about 20% by mass or less, and particularly preferably about 10% by mass or less but greater than 0%, based on the total amount of the HCFO, the organosiloxane component, and the alcohol.
In the solution composition of the present disclosure, the alcohol content is preferably 99.9% by mass or less, preferably about 60% by mass or less, more preferably about 30% by mass or less to about 10% by mass, based on the total of the organosiloxane components and alcohol (100%). It may be less than about 10% by mass and greater than 0% by mass. When the lubricant solution is dissolved with HCFO or when the lubricant solution is washed immediately after application, the alcohol content relative to the total of the organosiloxane components and alcohol is approximately the same as that of the lubricant solution. When the lubricant is applied and then subjected to a process or environment in which the alcohol evaporates, such as drying, the alcohol content relative to the total of the organosiloxane components and alcohol in the solution composition of the present disclosure is presumably lower than that of the lubricant solution. The lower the organosiloxane component and alcohol content, the easier it is to obtain a highly pure HCFO using the recovery method of the present disclosure.

(Other ingredients)
The solution composition of the present disclosure may contain other components in addition to HCFO, organopolysiloxane components, and alcohol. Examples of such components include stabilizers derived from HCFO detergents or silicone-based lubricants, surfactants, antioxidants, rust inhibitors, fragrances, organic solvents, and water. The solution composition of the present disclosure may contain these other components to the extent that the effects of the present disclosure are not impaired.

The solution composition may be a solution containing HCFO and a silicone-based lubricant as an organic polysiloxane component. HCFO is sometimes used as a solvent for silicone-based lubricants, which may contain an organic polysiloxane component and an alcohol. Such solutions containing organic polysiloxane components are sometimes produced in large quantities as waste liquid when applying a silicone-based lubricant to an article or removing silicone lubricant stains from an article. The technical significance of this disclosure lies in the ability to recover useful components such as HCFO in high purity from such waste liquid through a two-step process consisting of a vaporization step, a condensation step, and a two-layer formation step and a recovery step.

One embodiment of the solution composition of the present disclosure includes a solution composition containing Z-1-chloro-3,3,3-trifluoropropene, an organic polysiloxane component, and at least one alcohol selected from the group consisting of methanol, ethanol, 2-propanol, and 1-propanol. Japanese Patent Application Laid-Open Publication No. 2018-048149 discloses that Z-1-chloro-3,3,3-trifluoropropene forms an azeotrope-like composition with methanol, ethanol, or 2-propanol. Therefore, since the solvent composition forms an azeotrope-like composition or the boiling points of Z-1-chloro-3,3,3-trifluoropropene and the alcohol are close, it is difficult to separate Z-1-chloro-3,3,3-trifluoropropene and the alcohol by distillation. This explains the technical significance of the two-stage process of the present disclosure.

One embodiment of the solution composition of the present disclosure is a solution composition containing 1-chloro-2,3,3-trifluoropropene, an organic polysiloxane component, and at least one alcohol selected from the group consisting of methanol, ethanol, 2-propanol, and 1-propanol.

WO-A1-2017/122802 discloses that 1-chloro-2,3,3-trifluoropropene forms an azeotrope-like composition with ethanol or 2-propanol. Therefore, because the solvent composition forms an azeotrope-like composition or the boiling points of 1-chloro-2,3,3-trifluoropropene and the alcohol are close, it is difficult to separate 1-chloro-2,3,3-trifluoropropene and the alcohol by distillation, which is why the two-stage process disclosed herein is technically significant.

One embodiment of the solution composition of the present disclosure is a solution composition containing 1,2-dichloro-3,3,3-trifluoropropene, an organic polysiloxane component, and at least one alcohol selected from the group consisting of methanol, ethanol, 2-propanol, and 1-propanol. Because 1,2-dichloro-3,3,3-trifluoropropene has a boiling point close to that of the alcohol, separation from the alcohol by distillation is difficult, and this is where the two-stage process of the present disclosure has technical significance.

(Collection method)
The recovery method of the present disclosure is characterized by a two-stage process including: a first vaporization step of vaporizing the hydrochlorofluoroolefin and the alcohol from a solution composition containing a hydrochlorofluoroolefin, an organic polysiloxane component, and an alcohol to form vapor; a first condensation step of condensing the vapor to form a condensate; a first two-layer formation step of contacting the condensate with water to form two separate layers, an organic layer and an aqueous layer in which the alcohol is dissolved; and a first recovery step of recovering the organic layer. In the first vaporization step, the organic polysiloxane component becomes a distillation residue and is separated from the vaporized hydrochlorofluoroolefin and alcohol.

[First embodiment]
As an example of this recovery method, a method for recovering a solution composition containing Z-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd(Z)) and the silicone oil MDX4-4159 (manufactured by Dow Corning Corporation) will be described. This MDX4-4159 contains approximately 50% by mass of dimethoxysilyldimethylaminoethylaminopropyl silicone as a polyorganosiloxane component, approximately 20% by mass of methanol and 2-propanol as alcohols, and approximately 30% by mass of other components. Examples of other components include impurities such as hydrocarbons with low boiling points.

Z-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd(Z)) can be synthesized using known methods. For example, as described in JP 2020-203916 A, it can be synthesized by reacting 1,1,1,3,3-pentachloropropane (hereinafter also referred to as "HCFC-240fa") as a raw material with hydrogen fluoride in the gas phase in the presence of a solid catalyst and chlorine.

(First vaporization step)
A solution composition containing HCFO-1233zd(Z), MDX4-4159, methanol, and 2-propanol is placed in a heating vessel and heated with hot water at 60°C to 80°C, thereby generating organic matter as vapor.

The method for generating steam in the first vaporization step of the present disclosure is not particularly limited, and any conventional evaporation method for a solution composition containing a solvent can be used. Examples include a method in which the volatile components are evaporated by leaving the article stationary, a method in which steam is generated by air drying, a method in which steam is generated by heating, and a method in which steam is generated by lowering the boiling point through reduced pressure. These evaporation methods may also be used in combination. When generating steam by heating, the heating temperature should be equal to or higher than the boiling point of the HCFO contained in the solution composition, from the perspective of vaporizing the HCFO. A temperature of 10°C to 100°C (55±45°C) is preferred, a temperature of 40°C to 90°C (65±25°C) is more preferred, and a temperature of 60°C to 80°C (70±10°C) is even more preferred.

(First condensation step)
In the case of the method of generating vapor by heating, the vapor obtained in the first vaporization step can be collected and cooled in a Liebig condenser connected to a heating vessel and a receiver cooled with ice water to obtain a condensate. The obtained condensate contains HCFO-1233zd(Z), 2-propanol, methanol, and other components.

The condensation method used in the first condensation step of the present disclosure is not particularly limited, and any method can be used in which vapor is condensed to obtain a liquid. For example, a method of collecting vapor and cooling it to obtain a liquid, or a method of obtaining a liquid using a compressor and condenser such as those used in refrigeration cycle systems, can be used. The form of the liquid is not particularly limited, and it can be in the form of fine water droplets like steam. From the perspective of condensing the HCFO, the cooling temperature should be below the boiling point of the HCFO contained in the solution composition. From the perspective of easy cooling using ice or a cooler, a temperature of 10°C or below is preferred, and 0°C or below is more preferred.

(First second layer formation step)
A stirring bar, HCFO-1233zd(Z), 2-propanol as an alcohol, and the condensate obtained in the first condensation step containing methanol and water are placed in a stirring vessel, stirred, and then allowed to stand, whereby the mixture can be separated into two layers: an organic layer and an aqueous layer in which the alcohol has been dissolved.

In the first second-layer formation process of the present disclosure, the method for contacting the condensate with water may be any method that allows contact between the condensate and water. For example, the method may involve contacting the condensate with water in the form of fine droplets in the air, or the method may involve placing the condensate and water in a container and contacting them in the form of a solution. To improve contact efficiency, it is also possible to adjust the airflow, use stirring blades or stirrers, or shake the container. Furthermore, to adjust the solubility of the alcohol, the contact may be carried out while adjusting the temperature, such as by heating. Preferably, the mixture is stirred at 20°C to 25°C for approximately 30 minutes. By contacting the condensate with water, the alcohol contained in the condensate dissolves in the aqueous layer, thereby reducing the amount of alcohol contained in the condensate. Any water capable of dissolving alcohol may be used, such as tap water or, preferably, ultrapure water.

In the first two-layer formation step of the present disclosure, known and commonly used methods can be used to form two separate layers, an organic layer and an aqueous layer. For example, a method can be used in which a solution containing a mixture of the organic layer and the aqueous layer is allowed to stand. To promote layer separation, the standing temperature can be further adjusted, for example by heating.

(First recovery process)
By transferring the organic layer of the aqueous layer and organic layer separated in the first two-layer formation to a separate container, the organic layer containing HCFO-1233zd(Z) with significantly reduced amounts of 2-propanol and methanol can be recovered.

The method for recovering the organic layer in the first recovery step of the present disclosure is not particularly limited, and a method can be used in which the organic layer separated from the aqueous layer is recovered separately. For example, a tank having piping may be used in the tank in which the first two-layer formation step is performed, and the organic layer may be extracted using the piping after the two-layer formation. In this case, if the piping for extracting the organic layer is connected to a washing tank in which the article is washed and a mechanism is provided for sending the recovered organic layer to the washing tank, evaporation loss of the recovered organic layer can be suppressed.

The first recovery step of the present disclosure may also include a first A confirmation step in which the purity of the hydrochlorofluoroolefin contained in the recovered organic layer is determined to be 95 GC% or higher by gas chromatography (hereinafter sometimes referred to as GC) using an FID as a detector, as described below. When it is confirmed that the purity of the hydrochlorofluoroolefin in the recovered organic layer is 95 GC% or higher, the organic layer can be reused as hydrochlorofluoroolefin.

The first recovery step of the present disclosure may also include a first confirmation step (B) of confirming that the purity of the hydrochlorofluoroolefin contained in the recovered organic layer is less than 95 GC% by GC using an FID as a detector, as described below. If the purity of the hydrochlorofluoroolefin is confirmed to be less than 95 GC%, the following steps are carried out: a second vaporization step of vaporizing the organic layer after the purity confirmation to form a vapor containing the hydrochlorofluoroolefin and alcohol; a second condensation step of condensing the vapor to form a condensate; a second two-layer formation step of contacting the condensate with water to form two separate layers, an organic layer and an aqueous layer; and a second recovery step of recovering the organic layer from the two layers.

The methods used in the second vaporization process, second condensation process, second two-layer formation process, and second recovery process are the same as those used in the first vaporization process, first condensation process, first two-layer formation process, and first recovery process described above.

The purity of the hydrochlorofluoroolefins is confirmed by GC, and by repeating the second vaporization process, second condensation process, second two-layer formation process, and second recovery process described above depending on the purity, it is possible to recover hydrochlorofluoroolefins of high purity that can be reused as solvents or cleaning agents.

Hydrochlorofluoroolefins with a purity of less than 95 GC% contain impurities, and it may be difficult to meet the solubility and cleaning performance required of hydrochlorofluoroolefins. If an attempt is made to obtain only hydrochlorofluoroolefins with a purity of 95 GC% or higher in a single purification operation, the amount recovered may be small. A purity of 95 GC% is sufficient to achieve both the performance and recovery efficiency required of hydrochlorofluoroolefins. From the perspective of the industrial applicability of the purification method disclosed herein, it can be said that the technical significance of the recovery process disclosed herein lies in using a purity of 95 GC% as the judgment standard.

The first recovery step and the second recovery step of the present disclosure may include a step of drying the recovered organic layer. Drying the recovered organic layer removes moisture from the organic layer, contributing to stabilizing the dissolution and cleaning performance of the recovered hydrochlorofluoroolefin. The recovered organic layer can be dried using known, publicly used methods, such as treating the recovered organic layer with a drying agent such as zeolite, magnesium sulfate, sodium sulfate, or molecular sieves.

Second Embodiment
As an example of this purification method, a method for purifying a solution composition containing 1-chloro-2,3,3-trifluoro-1-propene (HCFO-1233yd (mass ratio of E/Z isomers: 6.7/93.3)), silicone oil MDX4-4159, and alcohols such as methanol and 2-propanol will be described.

1-Chloro-2,3,3-trifluoro-1-propene can be synthesized by known methods. For example, as described in Republished Publications 2019-208546 and 2018-101323, it can be synthesized by a dehydrofluorination reaction using 1-chloro-2,2,3,3-tetrafluoropropane (hereinafter also referred to as "HCFC-244ca") as a raw material and potassium hydroxide as a reactant at a temperature of 10 to 70°C.

The HCFO-1233yd obtained from this reaction may contain a greater proportion of HCFO-1233yd(Z) than HCFO-1233yd(E). Furthermore, the crude HCFO-1233yd obtained from this reaction may contain the raw material HCFC-244ca and the by-product 1-chloro-3,3-difluoro-1-propyne.

(First vaporization step)
In the method of generating steam by heating, a solution composition containing HCFO-1233yd (mass ratio of E/Z isomers: 6.7/93.3), MDX4-4159, methanol, and 2-propanol is placed in a heating container and heated with hot water at 60°C to 80°C, thereby generating organic matter as steam.

The method for generating steam in the first vaporization step of the present disclosure is not particularly limited, and any conventional evaporation method for a solution composition containing a solvent can be used. Examples include a method in which the volatile components are evaporated by leaving the article stationary, a method in which steam is generated by air drying, a method in which steam is generated by heating, and a method in which steam is generated by lowering the boiling point through reduced pressure. These evaporation methods may also be used in combination. When generating steam by heating, the heating temperature should be equal to or higher than the boiling point of the HCFO contained in the solution composition, from the perspective of vaporizing the HCFO. A temperature of 10°C to 100°C (55±45°C) is preferred, 40°C to 90°C (65±25°C) is more preferred, and 60°C to 80°C (70±10°C) is even more preferred.

(First condensation step)
In the case of a method in which the vapor obtained in the first vaporization step is generated by heating, the vapor can be collected and cooled in a Liebig condenser connected to a heating vessel and a receiver cooled with ice water to obtain a condensate. The obtained condensate contains HCFO-1233yd, 2-propanol, methanol, and other components. The other components include impurities such as low-boiling hydrocarbons derived from silicone oil.

The condensation method used in the first condensation step of the present disclosure is not particularly limited, and any method can be used in which vapor is condensed to obtain a liquid. For example, a method of collecting vapor and cooling it to obtain a liquid, or a method of obtaining a liquid using a compressor and condenser such as those used in refrigeration cycle systems, can be used. The form of the liquid is not particularly limited, and it can be in the form of fine water droplets like steam. From the perspective of condensing the HCFO, the cooling temperature should be below the boiling point of the HCFO contained in the solution composition. From the perspective of easy cooling using ice or a cooler, a temperature of 10°C or below is preferred, and 0°C or below is more preferred.

(First second layer formation step)
A stirrer, the condensate obtained in the first condensation step containing HCFO-1233yd(Z), 2-propanol, and methanol, and water are placed in a container, stirred, and allowed to stand, whereby the mixture can be separated into two layers: an organic layer and an aqueous layer in which the alcohol is dissolved.

The method for contacting the condensate with water in the first second-layer formation step of the present disclosure may be any method that allows contact between the condensate and water. For example, the method may involve contacting the condensate with water in the form of fine droplets in the air, or the method may involve placing the condensate and water in a container and contacting them in the form of a solution. To improve contact efficiency, it is also possible to adjust the airflow, use stirring blades or stirrers, or shake the container. Furthermore, to adjust the solubility of the alcohol, the contact may be carried out while adjusting the temperature, such as by heating. Preferably, the mixture is stirred at 20°C to 25°C for approximately 30 minutes. By contacting the condensate with water, the alcohol contained in the condensate dissolves in the aqueous layer, reducing the amount of alcohol contained in the condensate.

In the first two-layer formation step of the present disclosure, known and commonly used methods can be used to form two layers, an organic layer and an aqueous layer. For example, a method can be used in which a solution containing a mixture of the organic layer and the aqueous layer is allowed to stand. To promote separation, the standing temperature can be further adjusted, for example by heating.

(First recovery step of separating the two layers and recovering the organic layer)
By transferring the organic layer separated in the first two-layer formation to a separate container, the organic layer containing HCFO-1233yd(Z) with significantly reduced amounts of 2-propanol and methanol can be recovered.

The method for recovering the organic layer in the first recovery step of the present disclosure is not particularly limited, and a method can be used in which the organic layer separated from the aqueous layer is recovered separately. For example, a tank having piping may be used in the tank in which the first two-layer formation step is performed, and the organic layer may be extracted using the piping after the two-layer formation. In this case, if the piping for extracting the organic layer is connected to a washing tank in which the article is washed and a mechanism is provided for sending the recovered organic layer to the washing tank, evaporation loss of the recovered organic layer can be suppressed.

HCFOs with 1 to 3 carbon atoms and alcohols with 1 to 3 carbon atoms have physical properties such as boiling points and solubility similar to those of the HCFOs and alcohols of the first and second embodiments, making the recovery method of the present disclosure particularly useful.

[Manufacturing method overview]
Hereinafter, a method for producing the composition containing an HCFO, an organic polysiloxane component, and an alcohol according to this embodiment will be described.

This manufacturing method allows for easy separation of the organic polysiloxane component and alcohol component from a composition containing HCFO, an organic polysiloxane component, and an alcohol.

(Manufacturing method)
The production method of the present disclosure is characterized by comprising: a first vaporization step of converting a solution composition containing a hydrochlorofluoroolefin, an organic polysiloxane component, and an alcohol into vapor containing the hydrochlorofluoroolefin and the alcohol; a first condensation step of condensing the vapor to form a condensate; a first two-layer formation step of contacting the condensate with water to form two layers separated into an organic layer and an aqueous layer; and a first recovery step of recovering the organic layer.

The first recovery process of the present disclosure may include a first A confirmation process and a first B confirmation process.

The manufacturing method of the present disclosure may include a second vaporization process, a second condensation process, a second two-layer formation process, and a second recovery process.

The first recovery step and the second recovery step of the present disclosure may include a step of drying the recovered organic layer.

In the manufacturing method of the present disclosure, the first vaporization step, first condensation step, first second-layer formation step, first recovery step, 1A confirmation step, 1B confirmation step, second vaporization step, second condensation step, second second-layer formation step, second recovery step, and the step of drying the recovered organic layer are synonymous with the respective steps in the purification method described above.

The following provides a detailed explanation of the disclosed method for efficiently recovering HCFOs using examples, but the present disclosure is not limited to these examples.

Here, the "GC%" in the composition analysis values for the raw material and recovered organic matter represents the "GC area %" of the composition obtained by measuring the raw material and recovered organic matter using gas chromatography (detector: FID). Note that values are rounded to the nearest digit; for example, 0.0GC% indicates less than 0.05GC%.

[Test Example 1]
A 50 ml glass recovery flask was connected to a branched glass distillation apparatus equipped with a glass thermometer protection tube and a glass Liebig condenser. 9.90 g of 1-chloro-2,3,3-trifluoro-1-propene as HCFO and 0.10 g of silicone oil as the organopolysiloxane component and alcohol (HCFO/silicone oil = mass ratio 99/1) were weighed into the recovery flask. The 1-chloro-2,3,3-trifluoro-1-propene used was the raw material listed in Table 1 (mass ratio of E/Z isomers: 6.7/93.3), and the silicone oil used was MDX4-4159 (manufactured by DuPont).

A glass adapter was used to connect the Liebig condenser to a receiver, and a glass recovery flask containing a PTFE stirrer was installed. The recovery flask was cooled with ice water, allowing the distillate to be collected in a cooled state. Using warm water at 60-80°C, 9.10 g of organic matter was recovered as condensate through the evaporation and cooling processes, while taking care to avoid bumping (hereinafter, the evaporation and condensation processes may be referred to as the first stage).

Analysis of the resulting organic matter by gas chromatography revealed that it consisted of 98.65% 1-chloro-2,3,3-trifluoro-1-propene, 0.21% 2-propanol, 0.01% methanol, and 1.13% other components.

Next, a PTFE stirrer was placed in a 12 ml glass vial, and 2.00 g of the organic material recovered as a condensate and 2.00 g of ultrapure water were weighed out. The glass vial was then capped and stirred at room temperature (20°C to 25°C) for 30 minutes to bring the condensate and water into contact. The mixture was then allowed to stand to form two layers, after which the separated organic phase was recovered (hereinafter, the two-layer formation process and recovery process may be referred to as the latter step).

The resulting organic matter was analyzed by gas chromatography and found to be 98.79% 1-chloro-2,3,3-trifluoro-1-propene, 0.04% 2-propanol, trace amounts of methanol, and 1.17% other components. Detailed results are shown in Table 1.

[Test Example 2]
The same operation as in the first stage of Test Example 1 was carried out except that 9.50 g of 1-chloro-2,3,3-trifluoro-1-propene and 0.50 g of MDX4-4159 were used (HCFO/silicone oil = mass ratio 95/5), and 8.70 g of organic matter was recovered by distillation.

Analysis of the organic matter obtained after distillation recovery by gas chromatography revealed that it consisted of 97.95% 1-chloro-2,3,3-trifluoro-1-propene, 0.86% 2-propanol, 0.06% methanol, and 1.13% other components.

Next, the same procedure as in the latter part of Test Example 1 was carried out, except that 2.00 g of the distilled and recovered organic material and 2.00 g of ultrapure water were used, and the organic phase was recovered.

The resulting organic matter was analyzed by gas chromatography, revealing 98.62% 1-chloro-2,3,3-trifluoro-1-propene, 0.17% 2-propanol, trace amounts of methanol, and 1.21% other components. Detailed results are shown in Table 1.

[Test Example 3]
The same operation as in the first stage of Test Example 1 was carried out except that 9.00 g of 1-chloro-2,3,3-trifluoro-1-propene and 1.00 g of MDX4-4159 were used (HCFO/silicone oil = mass ratio 90/10), and 8.20 g of organic matter was recovered by distillation.

Analysis of the organic matter obtained after distillation recovery by gas chromatography revealed the following: 96.73% 1-chloro-2,3,3-trifluoro-1-propene, 1.78% 2-propanol, 0.13% methanol, and 1.36% other components.

Next, the same procedure as in the latter part of Test Example 1 was carried out, except that 2.00 g of the distilled and recovered organic material and 2.00 g of ultrapure water were used, and the organic phase was recovered.

The resulting organic matter was analyzed by gas chromatography, revealing 98.16% 1-chloro-2,3,3-trifluoro-1-propene, 0.35% 2-propanol, trace amounts of methanol, and 1.49% other components. Detailed results are shown in Table 1.

[Test Example 4]
The same operation as in the first stage of Test Example 1 was carried out except that 7.50 g of 1-chloro-2,3,3-trifluoro-1-propene and 2.50 g of MDX4-4159 were used (HCFO/silicone oil = mass ratio 75/25), and 6.61 g of organic matter was recovered by distillation.

Analysis of the organic matter obtained after distillation recovery by gas chromatography revealed the following: 93.14% 1-chloro-2,3,3-trifluoro-1-propene, 4.71% 2-propanol, 0.45% methanol, and 1.70% other components.

Next, the same procedure as in Example 1 was carried out, except that 2.00 g of the distilled organic material and 2.00 g of ultrapure water were used, and the organic phase was recovered.

The resulting organic matter was analyzed by gas chromatography, revealing 97.09% 1-chloro-2,3,3-trifluoro-1-propene, 0.98% 2-propanol, 0.01% methanol, and 1.92% other components. Detailed results are shown in Table 1.

[Test Example 5]
The same operation as in the first stage of Test Example 1 was carried out except that 5.00 g of 1-chloro-2,3,3-trifluoro-1-propene and 5.00 g of MDX4-4159 were used (HCFO/silicone oil = mass ratio 50/50), and 3.76 g of organic matter was recovered by distillation.

Analysis of the organic matter obtained after distillation recovery by gas chromatography revealed the following: 87.21% 1-chloro-2,3,3-trifluoro-1-propene, 8.95% 2-propanol, 1.51% methanol, and 2.33% other components.

Next, the same procedure as in the latter part of Test Example 1 was carried out, except that 1.50 g of the distilled and recovered organic material and 1.50 g of ultrapure water were used, and the organic phase was recovered.

The resulting organic matter was analyzed by gas chromatography and found to be 95.41% 1-chloro-2,3,3-trifluoro-1-propene, 1.84% 2-propanol, 0.05% methanol, and 2.70% other components. Detailed results are shown in Table 1.

[Test Example 6]
The same operation as in the first half of Test Example 1 was carried out, except that 9.90 g of HCFO 1-chloro-3,3,3-trifluoropropene and 0.10 g of MDX4-4159 were used instead of 1-chloro-2,3,3-trifluoro-1-propene (HCFO/silicone oil = mass ratio 99/1), and 9.05 g of organic matter was recovered by distillation.

Analysis of the organic matter obtained after distillation recovery by gas chromatography revealed that it consisted of 99.72% 1-chloro-3,3,3-trifluoropropene, 0.20% 2-propanol, 0.01% methanol, and 0.07% other components.

Next, the same procedure as in the latter part of Test Example 1 was carried out, except that 2.00 g of the distilled and recovered organic material and 2.00 g of ultrapure water were used, and the organic phase was recovered.

The resulting organic matter was analyzed by gas chromatography, revealing 99.90% 1-chloro-3,3,3-trifluoropropene, 0.02% 2-propanol, no detected methanol, and 0.08% other components. Detailed results are shown in Table 1.

[Test Example 7]
The same operation as in the first half of Test Example 1 was carried out, except that 9.50 g of HCFO 1-chloro-3,3,3-trifluoropropene and 0.50 g of MDX4-4159 were used instead of 1-chloro-2,3,3-trifluoro-1-propene (HCFO/silicone oil = mass ratio 95/5), and 9.12 g of organic matter was recovered by distillation.

Analysis of the organic matter obtained after distillation recovery by gas chromatography revealed that it consisted of 99.34% 1-chloro-3,3,3-trifluoropropene, 0.44% 2-propanol, 0.02% methanol, and 0.19% other components.

Next, the same procedure as in the latter part of Test Example 1 was carried out, except that 2.00 g of the distilled and recovered organic material and 2.00 g of ultrapure water were used, and the organic phase was recovered.

The resulting organic matter was analyzed by gas chromatography, revealing 99.66% 1-chloro-3,3,3-trifluoropropene, 0.06% 2-propanol, no detected methanol, and 0.28% other components. Detailed results are shown in Table 1.

[Test Example 8]
The same operation as in the first half of Test Example 1 was carried out, except that 9.00 g of HCFO 1-chloro-3,3,3-trifluoropropene and 1.01 g of MDX4-4159 were used instead of 1-chloro-2,3,3-trifluoro-1-propene (HCFO/silicone oil = mass ratio 90/10), and 8.57 g of organic matter was recovered by distillation.

Analysis of the organic matter obtained after distillation recovery by gas chromatography revealed the following: 97.53% 1-chloro-3,3,3-trifluoropropene, 1.67% 2-propanol, 0.08% methanol, and 0.71% other components.

Next, the same procedure as in the latter part of Test Example 1 was carried out, except that 2.00 g of the distilled and recovered organic material and 2.00 g of ultrapure water were used, and the organic phase was recovered.

The resulting organic matter was analyzed by gas chromatography and found to be 99.04% 1-chloro-3,3,3-trifluoropropene, 0.20% 2-propanol, traces of methanol, and 0.76% other components. Detailed results are shown in Table 1.

[Test Example 9]
The same operation as in the first half of Test Example 1 was carried out, except that 7.50 g of HCFO 1-chloro-3,3,3-trifluoropropene and 2.50 g of MDX4-4159 were used instead of 1-chloro-2,3,3-trifluoro-1-propene (HCFO/silicone oil = mass ratio 75/25), and 6.90 g of organic matter was recovered by distillation.

Analysis of the organic matter obtained after distillation recovery by gas chromatography revealed the following: 95.55% 1-chloro-3,3,3-trifluoropropene, 3.42% 2-propanol, 0.38% methanol, and 0.64% other components.

Next, the same procedure as in the latter part of Test Example 1 was carried out, except that 2.00 g of the distilled and recovered organic material and 2.00 g of ultrapure water were used, and the organic phase was recovered.

The resulting organic matter was analyzed by gas chromatography and found to be 98.87% 1-chloro-3,3,3-trifluoropropene, 0.42% 2-propanol, traces of methanol, and 0.70% other components. Detailed results are shown in Table 1.

[Test Example 10]
The same operation as in the first half of Test Example 1 was carried out, except that 5.00 g of HCFO 1-chloro-3,3,3-trifluoropropene and 5.00 g of MDX4-4159 were used instead of 1-chloro-2,3,3-trifluoro-1-propene (HCFO/silicone oil = mass ratio 50/50), and 4.19 g of organic matter was recovered by distillation.

Analysis of the organic matter obtained after distillation recovery by gas chromatography revealed the following: 92.83% 1-chloro-3,3,3-trifluoropropene, 5.43% 2-propanol, 0.71% methanol, and 1.04% other components.

Next, the same procedure as in the latter part of Test Example 1 was carried out, except that 2.00 g of the distilled and recovered organic material and 2.00 g of ultrapure water were used, and the organic phase was recovered.

The resulting organic matter was analyzed by gas chromatography, revealing 98.24% 1-chloro-3,3,3-trifluoropropene, 0.65% 2-propanol, 0.01% methanol, and 1.10% other components. Detailed results are shown in Table 1.

As is clear from Table 1, when only the distillation operation (corresponding to the vaporization process and condensation process) of the composition is performed, it is difficult to completely separate HCFO from alcohols with similar boiling points. However, it is possible to reduce the amount of alcohols contained in HCFO by using the simple method of forming a two-layer structure using water.
Furthermore, as shown in Test Examples 5 and 10, high concentrations of HCFO can be recovered even from solution compositions containing high concentrations of organic polysiloxane components, such as those with a 50/50 HCFO/silicone oil (mass ratio).

These results demonstrate that the manufacturing and recovery methods disclosed herein make it possible to reduce the content of alcohols such as 2-propanol and methanol from a composition containing HCFO, a siloxane component, and an alcohol using a simple method that utilizes distillation and water, and to efficiently obtain high-purity hydrochlorofluoroolefins that can be reused as solvents or cleaning agents.

Claims (8)

a first vaporization step of vaporizing the hydrochlorofluoroolefin and the alcohol from a solution composition in which an organic polysiloxane component and an alcohol are dissolved in the hydrochlorofluoroolefin;
a first condensation step of condensing the vapor to form a condensate;
a first two-layer formation step of contacting the condensate with water to form two separate layers, an organic layer and an aqueous layer having the alcohol dissolved therein;
a first recovery step of recovering the organic layer. The recovery method described in claim 1, characterized in that the organic polysiloxane component is silicone oil, the hydrochlorofluoroolefin is used as a cleaning agent, and the alcohol is one or more selected from methanol, ethanol, and 2-propanol. 2. The method for recovering hydrochlorofluoroolefin according to claim 1, wherein the mass ratio of the hydrochlorofluoroolefin to the organic polysiloxane component is 99/1 to 50/50, and the content of the organic polysiloxane component and the alcohol is 50 mass% or less based on the total amount of the hydrochlorofluoroolefin , the organic polysiloxane component, and the alcohol. The recovery method described in claim 1, characterized in that the purity of the hydrochlorofluoroolefin contained in the organic layer is 95 GC% or more. When the purity of the hydrochlorofluoroolefin contained in the organic layer is less than 95 GC% in terms of GC%,
a second vaporization step of heating the organic layer to produce a vapor containing hydrochlorofluoroolefin and alcohol;
a second condensation step of condensing the vapor to form a condensate;
a second two-layer formation step of contacting the condensate with water to form two separate layers, an organic layer and an aqueous layer having the alcohol dissolved therein;
The recovery method according to claim 1 , further comprising a second recovery step of recovering the organic layer. The recovery method described in claim 1, further comprising a step of drying the organic layer recovered in the first recovery step to remove moisture from the organic layer. The recovery method described in claim 1, wherein the vapor is cooled to 10°C or below in the first condensation step. The hydrochlorofluoroolefin is at least one of monochlorotrifluoropropene and dichlorotrifluoropropene,
2. The method according to claim 1, wherein the alcohol is at least one of methanol, ethanol, 2-propanol, and 1-propanol.