Container and method for storing fluorine-containing resin of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene

Abstract

The invention provides a storage container for Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene, a liquid isolation layer is arranged on the surface of the inner wall of the storage container, and the material of the liquid isolation layer is thermoplastic resin containing fluorine atoms in the molecular structure. By the adoption of the container, it can be guaranteed that Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene is stable in property in the storage period, purity, acid content, moisture, evaporation residues, Hassen chromaticity and the like are not greatly changed before and after storage, follow-up use and production of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene are not affected, and the storage container and the storage method are low in cost, safe and reliable.

Description

Technical Field

[0001] This application relates to the storage of Z-1,1,1,4,4,4-hexafluoro-2-butene, and particularly to the use of thermoplastic resins containing fluorine atoms for the storage of Z-1,1,1,4,4,4-hexafluoro-2-butene. Background Art

[0002] 1,1,1,4,4,4-Hexafluoro-2-butene (HFO-1336mzz) has geometric isomers of trans form (E form) and cis form (Z form), which are respectively referred to as HFO-1336mzz(E) and HFO-1336mzz(Z). The carbon-carbon double bond contained in the HFO-1336mzz molecule makes its life cycle in the atmosphere extremely short and its global warming potential extremely low. In addition, HFO-1336mzz has characteristics such as low toxicity and non-flammability. Therefore, HFO-1336mzz is recognized as an environmentally friendly substitute for chlorofluorocarbons, and belongs to the same level as hydrofluoroolefins in terms of environmental performance, belonging to the fourth generation of products.

[0003] HFO-1336mzz(E) is mainly used as a blowing agent and heat transfer fluid, and is suitable for the foaming of polyurethane insulation materials in the fields of household appliances, building insulation, cold chain transportation and industrial insulation, as well as the refrigeration of low-pressure centrifugal chillers. HFO-1336mzz(Z) is mainly used as a blowing agent and has excellent application prospects in the field of building insulation.

[0004] CN109415138 discloses a method for storing 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd), using epoxy·phenolic resin, phenolic resin, phenol·butyral resin, stainless steel, iron phosphate, and zinc phosphate to store 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd), but there is almost no record of the storage method of HFO-1336mzz(Z) in the prior art. Summary of the Invention

[0005] In view of the problems existing in the prior art, this application provides a storage container and a storage method for Z-1,1,1,4,4,4-hexafluoro-2-butene.

[0006] 1. A storage container for Z-1,1,1,4,4,4-hexafluoro-2-butene, wherein a liquid isolation layer is provided on the inner wall surface of the storage container, and the material of the liquid isolation layer is a thermoplastic resin containing fluorine atoms in its molecular structure.

[0007] 2. The storage container according to item 1, wherein the thermoplastic resin includes one or more of polyvinylidene fluoride (PVDF), ethylene-tetrafluoroethylene copolymer (ETFE), polyvinyl fluoride (PVF), and polytetrafluoroethylene (PTFE).

[0008] 3. The storage container according to item 1, wherein the storage container is a sealed container.

[0009] 4. A method for storing Z-1,1,1,4,4,4-hexafluoro-2-butene, wherein the storage container described in any one of items 1-3 is used to store Z-1,1,1,4,4,4-hexafluoro-2-butene.

[0010] 5. The storage method according to item 4, wherein after storage for 3 to 9 months, the purity of the Z-1,1,1,4,4,4-hexafluoro-2-butene is maintained at 99.8% to 99.99%.

[0011] 6. The storage method according to item 4, wherein after storage for 3 to 9 months, the evaporation residue of the Z-1,1,1,4,4,4-hexafluoro-2-butene is maintained at 1 to 100 ppm.

[0012] 7. The storage method according to item 4, wherein after storage for 3 to 9 months, the acid content of the Z-1,1,1,4,4,4-hexafluoro-2-butene is maintained at 0.1 to 1 ppm or less.

[0013] 8. The storage method according to item 4, wherein after storage for 3 to 9 months, the water content of the Z-1,1,1,4,4,4-hexafluoro-2-butene is maintained at 20 to 100 ppm.

[0014] 9. The storage method according to item 4, wherein after storage for 3 to 9 months, the Hazen color number of the Z-1,1,1,4,4,4-hexafluoro-2-butene is maintained at 2 to 18.

[0015] 10. A Z-1,1,1,4,4,4-hexafluoro-2-butene product, which includes Z-1,1,1,4,4,4-hexafluoro-2-butene and the storage container described in any one of items 1-3.

[0016] Using the container described in the present application can ensure that the properties of Z-1,1,1,4,4,4-hexafluoro-2-butene are stable during storage, including that there are no significant changes in the acid content, water content, purity, evaporation residue, Hazen color number, etc. before and after storage, and it will not affect its subsequent use and production. The storage method described in the present application has low cost and is safe and reliable. Detailed implementation mode

[0017] Specific embodiments of the present application will be described in more detail below. Although specific embodiments of the present application are described, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present application can be understood more thoroughly and the scope of the present application can be fully conveyed to those skilled in the art.

[0018] The present application provides a storage container and a storage method for Z-1,1,1,4,4,4-hexafluoro-2-butene. The container can ensure the stable properties of Z-1,1,1,4,4,4-hexafluoro-2-butene during storage, including that there are no significant changes in acid content, moisture, purity, evaporation residue, hue (Hazen color number), etc. before and after storage, and it will not affect its subsequent use and production. The storage method of the present application is low-cost, safe and reliable.

[0019] A storage container for Z-1,1,1,4,4,4-hexafluoro-2-butene, wherein a liquid isolation layer is provided inside the storage container, and the material of the liquid isolation layer is a thermoplastic resin containing fluorine atoms in its molecular structure. For example, the material of the liquid isolation layer can be polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), ethylene-tetrafluoroethylene copolymer (ETFE), polyvinyl fluoride (PVF), ethylene-chlorotrifluoroethylene copolymer (ECTFE), perfluoroethylene-propylene copolymer (FEP) or vinylidene fluoride-hexafluoroisobutene copolymer. The liquid isolation layer is provided on the inner wall of the storage container, and the liquid isolation layer is in direct contact with the liquid inside the storage container, so that the physical and chemical properties of Z-1,1,1,4,4,4-hexafluoro-2-butene remain stable during storage, and the safety of the internal storage during storage and transportation is ensured. The liquid isolation layer can be a separate inner layer arranged along the shape of the storage container, or can be in the form of a thin film covering the inner wall of the storage container.

[0020] Z-1,1,1,4,4,4-Hexafluoro-2-butene is a liquid under normal temperature and pressure. The container used for storage does not require a special structure and can be of different materials and various forms. For example, it can be in the shape of a cube, a cuboid, a cylindrical barrel, etc. That is to say, the storage method of this application is not limited by the shape or size of the storage container. It can be a standard container. For example, in the prior art, containers made of iron (steel), stainless steel, or glass are commonly used, usually in the form of cans, bottles, barrels, etc. The size of the container is related to the storage capacity or transportation. For example, fixed storage containers such as storage tanks, 1L canned bottles that can be used for transportation, 20L barrel cans, 208L large barrel cans, and so on. It can also be a non-standard storage container, such as a large container with a specially customized size or a small-sized container. There is no special limitation on the material of the storage container in this application. For example, the material of a stainless steel container can be SUS316, SUS304, or JFE443CT, and this application also has no special limitation on the plate thickness of the stainless steel container. The liquid isolation layer described in this application can completely cover the inner wall of the storage container, regardless of the material, shape, and size of the container. The liquid isolation layer can prevent the liquid from directly contacting the storage container, thereby improving the rust prevention and chemical resistance of the storage container.

[0021] This application has no special limitation on the thickness of the liquid isolation layer. For example, it can be 30 - 60μm, such as 30μm, 35μm, 40μm, 45μm, 50μm, 55μm, 60μm. Those skilled in the art can adjust it according to factors such as the size of the container, the transportation volume, the storage volume, the processing difficulty, and the cost. For example, a 40μm liquid isolation layer is coated inside a 1L canned bottle, and a 50μm liquid isolation layer is coated inside a 208L large barrel can. Those skilled in the art can imagine that for the consideration of reducing processing difficulty or cost, etc., when the storage container is relatively small, the thickness of the liquid isolation layer can be relatively thin, and when the storage container is relatively large, the thickness of the liquid isolation layer can be relatively thick. Those skilled in the art can make a choice according to needs. Considering factors such as cost and processing difficulty comprehensively, it is preferred that the thickness of the liquid isolation layer is 40 - 50μm.

[0022] In some embodiments, the material of the liquid isolation layer is polyvinylidene fluoride (PVDF), ethylene-tetrafluoroethylene copolymer (ETFE), polyvinyl fluoride (PVF), or polytetrafluoroethylene (PTFE).

[0023] To ensure the stability and safety of Z-1,1,1,4,4,4-hexafluoro-2-butene during storage, a sealed container is used for storage. This application has no limitation on the sealing method. For example, it can be sealed with a screw cap or sealed with a valve.

[0024] To test the preservation effect of the preservation container described in this application, Z-1,1,1,4,4,4-hexafluoro-2-butene was filled in the preservation container described in this application for 3 to 9 months, for example, for 6 months, and multiple parameters of Z-1,1,1,4,4,4-hexafluoro-2-butene before and after preservation were detected, including purity, evaporation residue, acid content, moisture, Hazen color number, etc.

[0025] The purity of Z-1,1,1,4,4,4-hexafluoro-2-butene was detected by a gas chromatograph with a flame ionization detector (FID). According to the area percentage method, the purity of Z-1,1,1,4,4,4-hexafluoro-2-butene was calculated, and the unit of purity was %.

[0026] In some embodiments, for Z-1,1,1,4,4,4-hexafluoro-2-butene stored in the preservation container described in this application for 6 months, its purity was maintained at 99.8% to 99.99%, and the change in purity before and after preservation was less than 0.01%, that is, the change range was 0 to 0.01%.

[0027] The evaporation residue of Z-1,1,1,4,4,4-hexafluoro-2-butene refers to the ratio of the mass of the components remaining after the evaporation of Z-1,1,1,4,4,4-hexafluoro-2-butene to the total mass of Z-1,1,1,4,4,4-hexafluoro-2-butene before evaporation, and the unit of evaporation residue is ppm.

[0028] In some embodiments, for Z-1,1,1,4,4,4-hexafluoro-2-butene stored in the preservation container described in this application for 6 months, its evaporation residue was maintained at 1 to 100 ppm, such as 1 to 10 ppm, 1 to 20 ppm, 1 to 30 ppm, 1 to 40 ppm, 1 to 50 ppm, 1 to 60 ppm, 1 to 70 ppm, 1 to 80 ppm, 1 to 90 ppm. The change in evaporation residue before and after preservation was less than 20 ppm, that is, the change range was 0 to 20 ppm.

[0029] The acid content of Z-1,1,1,4,4,4-hexafluoro-2-butene refers to the ratio of the mass of the acid to the total mass of Z-1,1,1,4,4,4-hexafluoro-2-butene. In this application, the unit of acid content is ppm.

[0030] In some embodiments, after storing Z-1,1,1,4,4,4-hexafluoro-2-butene in the storage container described in this application for 6 months, its acid content remains at 0.1 - 1 ppm, such as 0.1 - 0.2 ppm, 0.1 - 0.3 ppm, 0.1 - 0.4 ppm, 0.1 - 0.5 ppm, 0.1 - 0.6 ppm, 0.1 - 0.7 ppm, 0.1 - 0.8 ppm, 0.1 - 0.9 ppm. The change range of the acid content before and after storage is less than 0.1 ppm, that is, the change range is 0 - 0.1 ppm.

[0031] The moisture content of Z-1,1,1,4,4,4-hexafluoro-2-butene refers to the ratio of the mass of moisture to the total mass of Z-1,1,1,4,4,4-hexafluoro-2-butene. In this application, the unit of moisture content is ppm.

[0032] In some embodiments, after storing Z-1,1,1,4,4,4-hexafluoro-2-butene in the storage container described in this application for 6 months, its moisture content remains at 20 - 100 ppm, such as 20 - 30 ppm, 20 - 40 ppm, 20 - 50 ppm, 20 - 60 ppm, 20 - 70 ppm, 20 - 80 ppm, 20 - 90 ppm. The change range of the moisture content before and after storage is less than 30 ppm, that is, the change range is 0 - 30 ppm.

[0033] The Hazen color number is an index used to measure the depth of the color of a liquid to evaluate the quality and purity of a product. The Hazen color number in this application is measured by the method specified in Japanese Industrial Standard K0071-1 (Test method for the color of chemical products) or a commercially available spectrophotometer conforming to the above standard.

[0034] In some embodiments, after storing Z-1,1,1,4,4,4-hexafluoro-2-butene in the storage container described in this application for 6 months, its Hazen color number remains at 2 - 18. The change range of the Hazen color number before and after storage is less than 10, that is, the change range is 0 - 10.

[0035] Generally, the storage and transportation of Z-1,1,1,4,4,4-hexafluoro-2-butene are carried out under normal temperature and pressure conditions. The storage container described in this application has no restrictions on temperature and pressure. Considering safety, the upper limit temperature for the storage and transportation of Z-1,1,1,4,4,4-hexafluoro-2-butene is 40 °C, or 35 °C, or 30 °C, and the lower limit temperature is -30 °C, or -15 °C, or 0 °C. The storage container described in this application can be stored in a refrigerated environment or in a non-refrigerated environment.

[0036] The present application also provides a product of Z-1,1,1,4,4,4-hexafluoro-2-butene, which includes Z-1,1,1,4,4,4-hexafluoro-2-butene and the storage container described in the present application.

[0037] Example 1

[0038] An iron (SPCC cold-rolled steel sheet) container with a volume of 208 L was used as the main body of the storage container. The wall thickness of the iron container was 0.8 mm. The material of the liquid isolation layer was polyvinylidene fluoride (PVDF), with a thickness of about 45 μm. Approximately 2 kg of Z-1,1,1,4,4,4-hexafluoro-2-butene with a purity of 99.95% was placed in this storage container, the screw cap was tightened, and it was left standing at room temperature for 6 months.

[0039] The purity, evaporation residue, acid content, water content, and Hazen color number of Z-1,1,1,4,4,4-hexafluoro-2-butene before and after storage in Example 1 were measured by the following methods.

[0040] (1) Purity

[0041] The purity of Z-1,1,1,4,4,4-hexafluoro-2-butene was measured by gas chromatography.

[0042] (2) Evaporation residue

[0043] A 300 mL beaker was dried in an oven at 100 °C for one hour, and then returned to room temperature in a desiccator containing silica gel (blue). The weight of the beaker was accurately measured (twice). 200 mL of Z-1,1,1,4,4,4-hexafluoro-2-butene was collected using a 200 mL graduated cylinder with a stopper, and its weight was measured.

[0044] The aforementioned beaker with a stir bar was placed on a hot plate with a stirrer set at 100 °C, and 100 mL of the collected Z-1,1,1,4,4,4-hexafluoro-2-butene was added and allowed to evaporate. When the volume decreased to 10 mL, the remaining 100 mL of Z-1,1,1,4,4,4-hexafluoro-2-butene was added, and evaporation continued until the sample was completely evaporated. After being placed in a desiccator for one hour, the weight of the beaker was accurately measured (twice).

[0045] (3) Acid content

[0046] Take about 0.0050 g of 0.5 N HCl (18.23 g / L) and place it in a 100 mL borosilicate glass wide-mouth bottle. Dilute it to about 100 g with ultrapure water to prepare HCl with a concentration of 1 ppm. Take about 25 g of the above-mentioned HCl with a concentration of 1 ppm and place it in a 100 mL borosilicate glass wide-mouth bottle. Dilute it to about 50 g with ultrapure water to prepare HCl with a concentration of 0.5 ppm. By the same method, prepare HCl with a concentration of 0.1 ppm from the HCl with a concentration of 1 ppm. For the above-mentioned HCl with concentrations of 1 ppm, 0.5 ppm, and 0.1 ppm, measure their pH values while stirring. According to the measurement results, prepare a calibration curve by logarithmic approximation.

[0047] In a 250 mL borosilicate glass container, add about 100 g of Z-1,1,1,4,4,4-hexafluoro-2-butene and about 100 g of ultrapure water for extraction. Recover the aqueous layer with a PFA separatory funnel to prepare a test solution. Measure the pH value of the test solution while stirring. According to the above measurement results, use the calibration curve to calculate the acid content of Z-1,1,1,4,4,4-hexafluoro-2-butene.

[0048] (4) Moisture

[0049] Use a Karl Fischer moisture analyzer to measure the moisture contained in Z-1,1,1,4,4,4-hexafluoro-2-butene.

[0050] (5) Hazen color

[0051] Use a spectrophotometric colorimeter to measure the Hazen color of Z-1,1,1,4,4,4-hexafluoro-2-butene.

[0052] The difference between Examples 2-4 and Example 1 is that the liquid isolation layer materials in Examples 2-4 are different, and other parameters are the same as those in Example 1.

[0053] Use the test method described in Example 1 to measure the purity, evaporation residue, acid content, moisture, and Hazen color of Z-1,1,1,4,4,4-hexafluoro-2-butene before and after storage in Examples 2-4.

[0054] The test results of the liquid isolation layer materials in Examples 1-4 and Z-1,1,1,4,4,4-hexafluoro-2-butene before and after storage are shown in Table 1.

[0055] Comparative Example

[0056] The difference between Comparative Examples 1-7 and Example 1 is that the liquid isolation layer materials in Comparative Examples 1-7 are different, and other parameters are the same as those in Example 1.

[0057] The purity, evaporation residue, acid content, moisture content, and Hazen color number of Z-1,1,1,4,4,4-hexafluoro-2-butene before and after storage in Comparative Examples 1-7 were determined using the test method described in Example 1.

[0058] The test results of the liquid barrier materials in Comparative Examples 1-7 and Z-1,1,1,4,4,4-hexafluoro-2-butene before and after storage are shown in Table 1.

[0059]

[0060] According to the data of Examples 1-4 in Table 1, using the thermoplastic resin containing fluorine atoms described in the present application as the storage container with a liquid barrier layer, during the storage of Z-1,1,1,4,4,4-hexafluoro-2-butene, there were no significant changes in the purity, acid content, moisture content, evaporation residue, and Hazen color number of Z-1,1,1,4,4,4-hexafluoro-2-butene, indicating that using the storage container described in the present application can ensure the physical and chemical properties of Z-1,1,1,4,4,4-hexafluoro-2-butene are stable and guarantee the safety of the internal stored substances during storage and transportation.

[0061] According to the data of Comparative Examples 1-4, when using the materials described in Comparative Examples 1-4 as the liquid barrier layer, although the change values of the acid content, evaporation residue, and Hazen color number of Z-1,1,1,4,4,4-hexafluoro-2-butene were small, the moisture content changed significantly, and the purity of Comparative Examples 2-4 also changed slightly.

[0062] According to the data of Comparative Examples 5-7, when using the materials described in Comparative Examples 5-7 as the liquid barrier layer, although the changes in the acidity, moisture content, purity, evaporation residue, and Hazen color number of Z-1,1,1,4,4,4-hexafluoro-2-butene were small, compared with the examples using fluorine-containing resin as the liquid barrier layer, the changes in the test data of Z-1,1,1,4,4,4-hexafluoro-2-butene before and after storage in the comparative examples were more obvious.

[0063] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as falling within the scope described in this specification.

[0064] The above-described embodiments only represent several implementation manners of the present application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A storage container for Z-1,1,1,4,4,4-hexafluoro-2-butene, wherein A liquid isolation layer is provided on the inner wall surface of the storage container, and the material of the liquid isolation layer is a thermoplastic resin containing fluorine atoms in its molecular structure.

2. The storage container according to claim 1, wherein The thermoplastic resin includes one or more of polyvinylidene fluoride (PVDF), ethylene-tetrafluoroethylene copolymer (ETFE), polyvinyl fluoride (PVF), and polytetrafluoroethylene (PTFE).

3. The storage container according to claim 1, wherein The storage container is a sealed container.

4. A method for preserving Z-1,1,1,4,4,4-hexafluoro-2-butene, wherein: Z-1,1,1,4,4,4-hexafluoro-2-butene is stored using the storage container according to any one of claims 1 to 3.

5. The storage method according to claim 4, wherein: After storage for 3 to 9 months, the purity of the Z-1,1,1,4,4,4-hexafluoro-2-butene is maintained at 99.8% to 99.99%.

6. The storage method according to claim 4, wherein: After storage for 3 to 9 months, the evaporation residue of the Z-1,1,1,4,4,4-hexafluoro-2-butene is maintained at 1 to 100 ppm.

7. The storage method according to claim 4, wherein: After storage for 3 to 9 months, the acid content of the Z-1,1,1,4,4,4-hexafluoro-2-butene is maintained below 0.1 to 1 ppm.

8. The storage method according to claim 4, wherein: After storage for 3 to 9 months, the moisture content of the Z-1,1,1,4,4,4-hexafluoro-2-butene is maintained at 20 to 100 ppm.

9. The storage method according to claim 4, wherein: After storage for 3 to 9 months, the Hazen color of the Z-1,1,1,4,4,4-hexafluoro-2-butene is maintained at 2 to 18.

10. A Z-1,1,1,4,4,4-hexafluoro-2-butene product, wherein: The invention comprises Z-1,1,1,4,4,4-hexafluoro-2-butene and the storage container according to any one of claims 1 to 3.

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