Composition, filling container, and storage method

Abstract

A composition that contains, silicon oxide, oxygen, and at least one hydrofluoroolefin selected from the group consisting of HFO-1123 and HFO-1132(E), and has an oxygen content of 2.5 vol% or less.

Description

Composition, filled container, and storage method

[0001] The present disclosure relates to a composition, a filled container, and a storage method.

[0002] In recent years, hydrofluoroolefins have attracted attention as compounds with low global warming potential. From such a viewpoint, for example, Patent Document 1 discloses a composition for thermal cycle systems containing a compound such as 1,1,2-trifluoroethylene (HFO-1123) and trans-1,2-difluoroethylene (HFO-1132(E)).

[0003] Japanese Unexamined Patent Application Publication No. 2024-045386

[0004] However, it has been found that HFO-1123 and HFO-1132(E) may generate hydrogen fluoride (HF) and corrode the filled container and the like when stored for a long period of time.

[0005] Accordingly, an object of the present disclosure is to provide a composition, a storage method, and a filled container that can suppress the amount of HF when HFO-1123 or HFO-1132(E) is stored.

[0006] The present disclosure includes the following aspects. <1> A composition comprising at least one hydrofluoroolefin selected from the group consisting of 1,1,2-trifluoroethylene and trans-1,2-difluoroethylene, silicon oxide, and oxygen, wherein the oxygen content is 2.5% by volume or less. <2> The composition according to the above <1>, wherein the content of silicon oxide is 1 mass ppm or more relative to the total amount of the composition. <3> A filled container comprising the composition according to the above <1> or <2>, and a storage container filled with the composition. <4> A storage method, wherein at least one hydrofluoroolefin selected from the group consisting of 1,1,2-trifluoroethylene and trans-1,2-difluoroethylene is sealed in a storage container in a state where a gas phase and a liquid phase coexist, the storage container contains silicon oxide, and the oxygen content is 2.5% by volume or less.

[0007] According to the present disclosure, a composition, a storage method, and a filled container that can suppress the amount of HF when HFO-1123 or HFO-1132(E) is stored are provided.

[0008] In this disclosure, numerical ranges indicated using "~" mean a range that includes the numbers before and after "~" as the minimum and maximum values, respectively. In numerical ranges described in stages in this disclosure, the upper or lower limit stated in one numerical range may be replaced with the upper or lower limit of another numerical range described in stages. Also, in numerical ranges described in this disclosure, the upper or lower limit stated in one numerical range may be replaced with the values ​​shown in the examples. In this disclosure, a combination of two or more preferred embodiments is a more preferred embodiment. In this disclosure, the amount of each component means the total amount of multiple substances if there are multiple substances corresponding to each component, unless otherwise specified.

[0009] In this disclosure, the content expressed in volume percent refers to the content in the gas phase (i.e., the whole) if it exists only in the gas phase, and the content in the gas phase if the gas phase and liquid phase coexist. In this disclosure, the content expressed in mass percent refers to the content in the entire composition.

[0010] <Composition> The composition of this disclosure contains at least one hydrofluoroolefin selected from the group consisting of 1,1,2-trifluoroethylene (HFO-1123) and trans-1,2-difluoroethylene (HFO-1132(E)) (hereinafter also referred to as "specific hydrofluoroolefin"), silicon dioxide, and oxygen, with an oxygen content of 2.5% by volume or less. The composition having the above configuration can suppress the amount of HF when stored. The reason for this is not clear, but it is presumed to be as follows.

[0011] HFO-1123 and HFO-1132(E) may generate HF when stored for a long period of time, and it has been experimentally determined that this is due to the presence of oxygen. In the composition of this disclosure, since silicon dioxide is contained, it is presumed that the generated HF is adsorbed by the silicon dioxide, thereby suppressing the amount of HF.

[0012] (Specific Hydrofluoroolefins) HFO-1123 and HFO-1132(E) may be commercially available or manufactured. HFO-1123 and HFO-1132(E) can be manufactured by known methods. For example, HFO-1123 can be manufactured by a hydrogen reduction of chlorotrifluoroethylene, a dehydrofluorination of 1,1,1,2-tetrafluoroethane (HFC-134a), etc. HFO-1132(E) can be manufactured by a dehydrofluorination of 1,1,2-trifluoroethane (HFC-143), a reduction of (E) or (Z)-1,2-dichloro-1,2-difluoroethylene (CFO-1112(E / Z)), or a dehydrochlorination of 1-chloro-1,2-difluoroethane (HCFC-142a), etc.

[0013] The content of the specific hydrofluoroolefin in the composition is preferably 50% by volume or more, more preferably 60% by volume or more, even more preferably 70% by volume or more, particularly preferably 80% by volume or more, extremely preferably 90% by volume or more, and may also be 95% by volume or more.

[0014] The content of HFO-1123 in the composition is preferably 50% by volume or more, more preferably 60% by volume or more, even more preferably 70% by volume or more, particularly preferably 80% by volume or more, extremely preferably 90% by volume or more, and may also be 95% by volume or more.

[0015] The content of HFO-1132(E) in the composition is preferably 50% by volume or more, more preferably 60% by volume or more, even more preferably 70% by volume or more, particularly preferably 80% by volume or more, extremely preferably 90% by volume or more, and may also be 95% by volume or more.

[0016] The content of specific hydrofluoroolefins in the composition can be measured by gas chromatography or other methods.

[0017] (Oxygen) The oxygen content in the composition is 2.5% by volume or less, preferably 2.0% by volume or less, more preferably 1.5% by volume or less, even more preferably 1.0% by volume or less, and particularly preferably 0.8% by volume or less. The lower limit of the oxygen content in the composition is not particularly limited, but may be 0.001% by volume or more, 0.01% by volume or more, 0.1% by volume or more, or 0.5% by volume or more. The oxygen content in the composition is preferably 0.001 to 2.5% by volume, more preferably 0.001 to 1.5% by volume, even more preferably 0.001 to 1.0% by volume, and particularly preferably 0.001 to 0.8% by volume.

[0018] The oxygen content in the composition is measured by gas chromatography.

[0019] (Silicon Oxide) Silicon oxide may be in a crystalline or amorphous (non-crystalline) state. Examples of silicon oxide include silica sand, quartz, diatomaceous earth, colloidal silica, precipitated silica, silica gel, fumed silica, rice husks, glass cullet, and glass beads.

[0020] The shape of silicon dioxide is not particularly limited and may be any irregular shape such as natural product or pulverized material, cullet-like, flaky, or spherical. It may also be molded into pellets, hollow shapes, cylindrical shapes, etc. Furthermore, silicon dioxide may have a porous structure (e.g., porous material). These shapes may be combined as appropriate, for example, a porous cylindrical molded product.

[0021] Silicon oxide is preferably low in impurities. From the viewpoint of suppressing the generation of unwanted by-products, silicon oxide particles are preferably low in impurities, and the silicon oxide content in silicon oxide particles is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more.

[0022] From the viewpoint of suppressing clogging in the filling container, the average particle size of silicon dioxide is preferably 10 nm or more, more preferably 50 nm or more, and even more preferably 100 nm or more. From the viewpoint of securing the surface area that serves as the reaction site, the average particle size of silicon dioxide is preferably 500 μm or less, more preferably 300 μm or less, and even more preferably 100 μm or less.

[0023] The average particle size of silicon dioxide is determined as the particle size (D50) at which the cumulative particle size distribution curve obtained by measurement using a Coulter counter reaches 50%. The aperture diameter is set appropriately according to the particle size range of the object being measured.

[0024] From the viewpoint of ensuring the adsorption of generated HF, the silicon dioxide content in the composition is preferably 1 ppm by mass or more, more preferably 10 ppm by mass or more, even more preferably 30 ppm by mass or more, and particularly preferably 40 ppm by mass or more. Furthermore, from the viewpoint of preventing contamination during use, the silicon dioxide content in the composition is preferably 10,000 ppm by mass or less, more preferably 5,000 ppm by mass or less, even more preferably 1,000 ppm by mass or less, and particularly preferably 500 ppm by mass or less.

[0025] The silicon dioxide content in a composition can be measured by collecting silicon dioxide from a predetermined amount of the composition through a fractional distillation apparatus into a glass fiber filter and analyzing it by powder X-ray diffraction (XRD).

[0026] (Dilution Gas) The composition may contain a dilution gas. Examples of dilution gases include nitrogen, hydrogen, carbon dioxide, helium, propane, isobutane, n-butane, ethane, propylene, 2,3,3,3-tetrafluoropropene (HFO-1234yf), difluoromethane (HFC-32), etc. When a dilution gas is included, the content of the dilution gas in the composition is preferably 10 to 90% by volume, more preferably 20 to 80% by volume, and even more preferably 30 to 70% by volume.

[0027] The content of the diluent gas in the composition can be measured by gas chromatography.

[0028] (Other components) The composition may contain other components. Examples of other components include raw materials used in the manufacture of specific hydrofluoroolefins, by-products that may be produced, and unavoidable components that are inevitably mixed in.

[0029] Examples of raw materials and by-products of HFO-1123 include 1,1,1,2-tetrafluoroethane (HFC-134a), chlorotrifluoroethylene (CTFE), vinylidene fluoride (VdF), and 1,1,2,2-tetrafluoroethane (HFC-134).

[0030] The raw materials and by-products of HFO-1132(E) include fluoroethylene, HFO-1123, 1,1,1-trifluoroethane, propylene, acetylene, difluoromethane (HFC-32), trifluoromethane, fluoromethane, 1,1-difluoroethane (HFC-152a), fluoroethane (HFC-161), 1,1,2-trifluoroethane (HFC-143), 2-chloro-1,1,1-trifluoroethane (HCFC-133b), 1-chloro-1,1,2-trifluoroethane (HCFC-133), 1,1-dichloro-2,2,2-trifluoroethane (HCFC-123), 1-chloro-1,2-difluoroethane (HCFC-142a), 1,2-difluoroethane (HFC-152), and chlorodifluoromethane. Examples include (HCFC-22), 1,1,1,2-tetrafluoroethane (HFC-134a), 1,1,2,2-tetrafluoroethane (HFC-134), pentafluoroethane (HFC-125), 2,3,3,3-tetrafluoropropene (HFO-1234yf), 1,2,3,3,3-pentafluoropropene (HFO-1225ye), 1,3,3,3-tetrafluoropropene (HFO-1234ze), fluoroethylene (HFO-1141), 3,3,3-trifluoropropene (HFO-1243zf), 1,1-difluoroethylene (HFO-1132a), 1-chloro-2,2-difluoroethylene (HCFO-1122), 1-chloro-1,2-difluoroethylene (HCFO-1122a), ethylene, etc.

[0031] The by-product content in the composition is preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 10% by mass or less, particularly preferably 5% by mass or less, very preferably 3% by mass or less, and very preferably 1% by mass or less. The lower the by-product content in the composition, the better.

[0032] An unavoidable component is silicon tetrafluoride (SiF ４ Examples include trifluoropropine, etc. The content of unavoidable components in the composition is preferably 20% by volume or less, more preferably 10% by volume or less, even more preferably 5% by volume or less, and particularly preferably 1% by volume or less. The lower the content of unavoidable components in the composition, the better.

[0033] The compositions disclosed herein are applicable to refrigerants and the like.

[0034] <Filling container> The filling container of the present disclosure comprises the composition of the present disclosure and a storage container filled with the composition.

[0035] The composition to be filled into the storage container is the same as the composition described above.

[0036] A general-purpose storage container can be used. For example, the material of the part of the storage container that comes into contact with the composition of this disclosure is preferably resin or metal. Examples of such containers include containers in which the entire container is made of resin or metal material, and containers having a multilayer structure in which the innermost layer is made of resin or metal material. Examples of storage containers in which the material of the part that comes into contact with the composition of this disclosure is metal include metal containers and metal-plated containers.

[0037] The shape and size of storage containers can be designed to suit the purpose. Examples include fixed storage containers such as storage tanks, transportable containers, and transport containers. Examples of transportable containers include 1L glass bottles, 20L pails, 200L drums, ton containers, aerosol cans, and high-pressure gas containers (containers that cannot be refilled, welded containers, seamless containers, etc.). Examples of transport containers include tank trucks, ISO containers, and self-loaders.

[0038] The method for sealing the storage container is not particularly limited, and examples thereof include a method of sealing with a screw cap and a method of sealing with a valve. An elastic member such as a cushioning material or a sealing material for enhancing airtightness may be used.

[0039] <Storage Method> In the storage method of the present disclosure, at least one hydrofluoroolefin selected from the group consisting of 1,1,2-trifluoroethylene and trans-1,2-difluoroethylene is sealed in a storage container in a state where a gas phase and a liquid phase coexist, and the inside of the storage container contains silicon oxide, with an oxygen content of 2.5% by volume or less.

[0040] The target object of the storage method of the present disclosure is the same as the above-described composition.

[0041] The pressure and temperature during storage are maintained at a level not higher than the specified values according to the design pressure and temperature of the container. When there is no particular specification, from the viewpoint of safety, the storage temperature is preferably 60°C or lower, more preferably 50°C or lower, still more preferably 40°C or lower, and even more preferably 30°C or lower. The lower limit of the storage temperature is not particularly limited, but is preferably -30°C or higher, more preferably -15°C or higher, and still more preferably 0°C or higher. For example, the storage can be performed in a well-ventilated environment not exposed to direct sunlight. If necessary, the storage may be performed using refrigeration equipment.

[0042] The storage method of the present disclosure can suppress the amount of HF even under storage conditions where the amount of HF generated from the specific hydrofluoroolefin is 100 ppm by volume or more when silicon oxide is not contained.

[0043] Hereinafter, the present disclosure will be described more specifically with reference to Examples, but the present disclosure is not limited to the following Examples as long as it does not exceed the gist thereof. Examples 1 and 2 are comparative examples, and Examples 3 and 4 are working examples.

[0044] [Examples 1 and 2] (Preparation of HFO-1123) 1,1,2-trifluoroethylene (HFO-1123) was obtained by hydrogenating chlorotrifluoroethylene.

[0045] (Storage Test) A SUS316 pressure-resistant vessel (maximum operating temperature 300°C, maximum operating pressure 20 MPa) was evacuated. Next, oxygen and nitrogen were sealed into the pressure-resistant vessel, followed by charging HFO-1123 to achieve the pre-storage gas composition shown in Table 1. The pre-storage gas composition (GC Area%) was analyzed by gas chromatograph. The concentrations of oxygen and nitrogen were measured by gas chromatography.

[0046] Subsequently, the pressure-resistant vessel was placed in a hot air circulation type constant temperature bath, and stored at a constant temperature of 90°C for the period shown in Table 1. For the gas after storage, the gas composition was analyzed by a gas chromatograph, and the HF content was measured using a detector tube from Gastec Corporation. The HF detection range of the used detector tube is 0.5 to 100 volume ppm. In cases where the value exceeded the detection limit, it is indicated as ">100 volume ppm" in Table 1.

[0047]

[0048] As shown in Table 1, in the compositions containing HFO-1123 and oxygen, in Examples 1 and 2 where the oxygen content was 2.5 vol% or less and silicon oxide was not contained, generation of HF was confirmed.

[0049] [Examples 3 to 4] Examples 3 and 4 were carried out in the same manner as Examples 1 and 2 respectively, except that 500 mass ppm of silicon oxide was added, and the same storage test was performed. As a result, HF was below the detection limit in both cases.

[0050] Since HFO-1132(E) is a hydrofluoroolefin having 2 carbon atoms, same as HFO-1123, it is presumed that generation of HF during storage is suppressed similarly to HFO-1123.

[0051] The entire disclosure of Japanese Patent Application No. 2025-067006 is incorporated herein by reference. All literatures, patent applications, and technical standards described in the present disclosure are incorporated into the present disclosure by reference to the same extent as if each individual literature, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. A composition containing at least one hydrofluoroolefin selected from the group consisting of 1,1,2-trifluoroethylene and trans-1,2-difluoroethylene, silicon dioxide, and oxygen, wherein the oxygen content is 2.5% by volume or less.

2. The composition according to claim 1, wherein the silicon dioxide content is 1 ppm by mass or more based on the total amount of the composition.

3. A filling container comprising the composition according to claim 1 or 2, and a storage container filled with the composition.

4. A storage method comprising sealing at least one hydrofluoroolefin selected from the group consisting of 1,1,2-trifluoroethylene and trans-1,2-difluoroethylene in a storage container in a state in which a gas phase and a liquid phase coexist, and containing silicon dioxide in the storage container, with an oxygen content of 2.5% by volume or less.

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