Stabilized (hydro)halogenated olefin composition

Abstract

The invention relates to a composition comprising: - at least one (hydro)halogenated olefin having the chemical formula: CX1X2=CX3X4 (I) in which X1 is chosen from F and Cl, and in which X2, X3 and X4 are independently chosen from H, F, and Cl; and, - at least one aliphatic alkene, having a boiling point less than or equal to 80°C measured at 1013 hPa; in which the (hydro)halogenated olefin is in gaseous form only or in liquid-gas equilibrium form. Figure for abstract: No figure

Description

Title of the invention: Stabilized (hydro)halogenated olefin composition Technical field

[0001] The invention relates to the field of (hydro)halogenated olefins and in particular their stabilization using a polymerization reaction inhibitor. Prior art

[0002] In the polymer manufacturing industry, for a large number of ethylenic monomers, a significant problem is related to the storage and / or transportation of these monomers.

[0003] Indeed, uncontrolled spontaneous polymerization of these monomers can occur over time, from free radicals which are notably generated by the residual presence of dioxygen, even in trace amounts.

[0004] For (hydro)halogenated olefins, a specific family of compounds, terpenes, is commonly used as a polymerization stabilizer / inhibitor. Among the terpenes, limonene, also called dipentene, is particularly well known. US patent 2407405 describes the stabilization of TFE during storage and handling by adding 0.5% of Terpene “B”, which is essentially a mixture of dipentene and terpinolene. Trifluoroethylene is generally sold stabilized with limonene (see Safety Data Sheet for trifluoroethylene marketed by the company Ha-locarbon - XP002673763).

[0005] One of the disadvantages of these organic compounds used as polymerization inhibitors is their relatively high molecular weight and especially their high boiling point (for example 176°C for dipentene). This aspect is particularly disadvantageous for fluorinated olefins, which are particularly volatile and have a very low boiling point (for example -72°C for vinyl fluoride, -76°C for tetrafluoroethylene, -61°C for trifluoroethylene). Indeed, since (hydro)halogenated olefins are generally stored in the form of compressed gases, possibly liquefied, i.e. in gaseous form only or in liquid / vapor equilibrium, this large difference in boiling point and therefore in partial pressure results in a low or even very low concentration of inhibitor in the monomer gas phase.

[0006] This quantity may prove insufficient to protect the monomer from spontaneous polymerization in a lasting and reliable manner.

[0007] Another disadvantage of these chemical compounds is their toxicity, often high, with regard to human health, as well as aquatic life and the environment. Goals

[0008] An objective of the invention is therefore to provide other inhibitors of polymerization of (hydro)halogenated olefins which do not have the disadvantages of the inhibitors described in the prior art. Description of the invention

[0009] The invention relates to a composition comprising:

[0010] - at least one (hydro)halogenated olefin having the chemical formula:

[0011] [Chem.l] CX1X2=CX3X4 (I)

[0012] in which Xi is chosen from F, Cl, and alkyl groups comprising from 1 to 3 carbon atoms which are partially or completely chlorinated and / or fluorinated, and in which

[0013] X2, X3 and X4 are independently selected from H, F, Cl and alkyl groups comprising from 1 to 3 carbon atoms which are optionally partially or completely chlorinated and / or fluorinated; and,

[0014] - at least one aliphatic alkene, having a boiling point less than or equal to 80°C measured at 1013 hPa;

[0015] in which the (hydro)halogenated olefin is present in gaseous form only or in liquid-gas equilibrium form.

[0016] The inventors of the present invention have surprisingly realized that aliphatic alkenes having a boiling point of less than or equal to 80°C could act as polymerization inhibitors for (hydro)halogenated olefins. Furthermore, due to their low boiling point, these inhibitors have the advantage of being able to be introduced at higher contents in the gas phase than terpenes.

[0017] According to certain embodiments, the (hydro)halogenated olefin of formula (I) is selected from the group consisting of: vinyl chloride, vinyl fluoride, 1,1-dichloroethene, 1,2-dichloroethene, 1,1-difluoroethene, 1,2-difluoroethene, chlorotrifluoroethylene, 1,1-chlorofluoroethene, 1,2-chlorofluoroethene, tetrafluoroethylene, 2,3,3,3-tetrafluoropropene, 2-chloro-3,3,3-trifluoropropene, 1,3,3,3-tetrafluoropropene, 1-chloro-3,3,3-trifluoropropene, 3,3,3-trifluoropropene, 1,1,1,2,3-pentafluoropropene, 3,3,3-trichloro-1,1,2-trifluoropropene, 3,3-dichloro-1,1,2,3-tetrafluoropropene, hexafluoropropene, 3,3-dichloro-1,1,3-trifluoropropene, 3,3-dichloro-1,2,3-trifluoropropene, 3,3-dichloro-1,1,2-trifluoropropene, 3-chloro-1,1,2,3-tetrafluoropropene, 2-chloro-1,1,3,3-tetrafluoropropene, 3-chloro-1,1,3,3-tetrafluoropropene, l-chloro-l,2,3,3-tetrafluoropropene, 1-chloro-1,3,3,3-tetrafluoropropene, 3-chloro-1,2,3,3-tetrafluoropropene, 2-chloro-1,3,3,3-tetrafluoropropene, l-chloro-2,3,3,3-tetrafluoropropene, 1, 1,3,3,3-pcntafluoropropcnc, 1,1,2,3,3-pentafluoropropene, 1,2,3,3,3-pentafluoropropene, 3-chloro-2,3,3-trifluoropropene, l-chloro-2,3,3-trifluoropropene, 2-chloro-1,3,3-trifluoropropene, 3-chloro-1,2,3-trifluoropropene, 3-chloro-1,3,3-trifluoropropene, 3-chloro-1,1,2-trifluoropropene, 2-chloro-1,1,3-trifluoropropene, 3-chloro-1,1,3-trifluoropropene, l-chloro-l,2,3-trifluoropropene, l-chloro-l,3,3-trifluoropropene, 2,3,3,3-tetrafluoropropene, 1,3,3,3-tetrafluoropropene, 1,1,2,3-tetrafluoropropene, 1,1,3,3-tetrafluoropropene, 1,2,3,3-tetrafluoropropene, 2,3,3-trichloropropene, 3,3,3-trichloropropene, 3-chloro-3,3-difluoropropene, 3-chloro-2,3-difluoropropene, 2-chloro-3,3-difluoropropene, 2-chloro-1,1-difluoropropene, 3-chloro-1,1 -difluoropropene, 3-chloro-1,2-difluoropropene, 2-chloro-1,3-difluoropropene, 3-chloro-1,3-difluoropropene, l-chloro-2,3-difluoropropene,l-chloro-3,3-difluoropropene, 1,1,3-trifluoropropene, 1,1,2-trifluoropropene, 1,2,3-trifluoropropene, 2,3,3-trifluoropropene, 1,3,3-trifluoropropene, 2,3-dichloropropene, 1,3-dichloropropene, 3,3-dichloropropene, 1,1-difluoropropene, 1,2-difluoropropene, 2,3-difluoropropene and 3,3-difluoropropene. ,

[0018] According to certain embodiments, the (hydro)halogenated olefin of formula (I) may essentially comprise an element chosen from the group consisting of trifluoroethylene, tetrafluoroethylene, chlorotrifluoroethylene, 1,1-chlorofluoroethene, and their mixture; preferentially from the group consisting of trifluoroethylene, tetrafluoroethylene, and their mixture.

[0019] According to particular embodiments, the (hydro)halogenated olefin of formula (I) may essentially comprise trifluoroethylene.

[0020] Here, the term "essentially" is understood to mean that the (hydro)halogenated olefins cited represent more than 95% by weight, preferably more than 96% by weight, preferably more than 97% by weight, preferably still more than 98% by weight and even more preferably more than 99% by weight relative to all possible (hydro)halogenated olefins.

[0021] According to certain embodiments, the (hydro)halogenated olefin of formula (I) may be selected from the group consisting of trifluoroethylene, tetrafluoroethylene, chlorotrifluoroethylene, 1,1-chlorofluoroethene, and their mixture; preferentially from the group consisting of trifluoroethylene, tetrafluoroethylene, and their mixture.

[0022] According to particular embodiments, the (hydro)halogenated olefin of formula (I) may be trifluoroethylene.

[0023] According to certain embodiments, the aliphatic alkene may have a boiling point at most equal to 60°C, and preferably at most equal to 50°C, measured at 1013 hPa. This has the advantage of being able to introduce the aliphatic alkene in high concentrations in the gas phase.

[0024] According to certain embodiments, the aliphatic alkene may be selected from the group consisting of propene, 1-butene, 2-butene, isobutylene, 1-pentene, 2-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 2-methyl-2-butene, 1-hexene, 2-hexene, 3-hexene, isomers of methyl-pentene, in particular 4-methyl-1-pentene, isomers of dimethylbutene, cyclopentene, and a mixture thereof.

[0025] The aliphatic alkene may in particular be chosen from the group consisting of: 1-butene, 2-butene, isobutylene and their mixture.

[0026] According to certain embodiments, the (hydro)halogenated olefin is only in the gaseous state. This form of storage is particularly recommended for certain monomers, such as trifluoroethylene.

[0027] According to certain embodiments, the aliphatic alkene is in liquid-vapor equilibrium. This makes it possible to saturate the gas phase with aliphatic alkene vapor.

[0028] According to certain embodiments, the (hydro)halogenated olefin represents at least 90%, or at least 91%, or at least 92%, or at least 93%, or at least 94%, or at least 95%, or at least 96%, or at least 97%, or at least 98%, or at least 99% by weight relative to the total weight of composition.

[0029] According to certain embodiments, the composition consists essentially of one or more (hydro)halogenated olefins and the aliphatic alkene(s).

[0030] The composition may comprise a low content of dioxygen, in particular gaseous dioxygen. The dioxygen content may be less than or equal to 2500 ppm molar, preferably less than or equal to 1000 ppm molar, preferably less than or equal to 500 ppm molar, more preferably less than or equal to 100 ppm molar, relative to the number of moles of (hydro)halogenated olefin in the gas phase. It is generally desirable for the dioxygen content to be as low as possible in the composition. However, due to the possibility of having a high content of aliphatic alkene in the gas phase making it possible to inhibit polymerization, a certain tolerance may be envisaged according to certain embodiments.The oxygen content may be strictly greater than 3 ppm molar, or strictly greater than 50 ppm molar, or strictly greater than 100 ppm, or strictly greater than 300 ppm, or strictly greater than 1000 ppm molar, relative to the number of moles of (hydro)halogenated olefin in the gas phase.

[0031] According to certain embodiments, the composition may comprise more than 100 ppm molar, preferably more than 250 ppm molar, more preferably more than 500 ppm molar, more preferably more than 750 ppm molar, and in a manner more preferably more than 1000 ppm molar of said aliphatic alkene in the gas phase, relative to the number of moles of (hydro)halogenated olefin in the gas phase.

[0032] According to certain embodiments, the composition may comprise less than 50,000 molar ppm, preferably less than 25,000 molar ppm, and more preferably less than 10,000 molar ppm of said aliphatic alkene in the gas phase, relative to the number of moles of (hydro)halogenated olefin in the gas phase.

[0033] According to certain embodiments, the composition may in particular comprise from 1 ppm to 100 ppm, or from 100 ppm to 1000 ppm, or from 1000 ppm to 2000 ppm, or from 2000 ppm to 3000 ppm, or from 3000 ppm to 4000 ppm, or from 4000 ppm to 5000 ppm, or from 5000 ppm to 6000 ppm, or from 6000 ppm to 7000 ppm, or from 8000 ppm to 9000 ppm, or from 9000 ppm to 10,000 ppm molar of said at least one aliphatic alkene in the gas phase, relative to the number of moles of (hydro)halogenated olefin in the gas phase.

[0034] The invention also relates to the use of an aliphatic alkene such as those mentioned above to stabilize, in particular to prevent any autopolymerization, of a hydro(halogenated) olefin such as those mentioned above.

[0035] The above-mentioned compositions can advantageously be used for the storage of hydro(halogenated) olefins. Detailed description of an embodiment

[0036] A particular embodiment consists in providing a composition comprising trifluoroethylene and a butene, for example but-1-ene, the butene inhibiting the polymerization, in particular the self-polymerization, of trifluoroethylene.

[0037] This composition can make it possible to store and / or transport trifluoroethylene while notably avoiding self-polymerization of the monomer.

[0038] The trifluoroethylene in the composition may be in the form of compressed gas, optionally liquefied. It may therefore be in gaseous form only or in the form of gas-liquid equilibrium.

[0039] The butene in the composition may also be in gas form only or in gas-liquid equilibrium form.

[0040] According to certain embodiments, the composition comprising trifluoroethylene and butene, suitable for use in the storage of trifluoroethylene, may be solely in gaseous form.

[0041] According to certain embodiments, the composition comprising trifluoroethylene and butene, suitable for use in the storage of trifluoroethylene, may comprise a gas phase and a liquid phase, the liquid phase being essentially constituted by butene.

[0042] Various processes for manufacturing trifluoroethylene are known. Among these processes, the production of trifluoroethylene by hydrogenolysis of chlorotrifluoroethylene is known in particular. Such a process is for example described in application EP 2 819 979 or application EP 2 993 213 (example 1). At the end of the process, a distillation step makes it possible to recover pure or almost pure trifluoroethylene or trifluoroethylene still containing a small quantity of impurities depending on the distillation conditions.

[0043] According to certain embodiments, the trifluoroethylene may have a purity greater than or equal to 95.0% (mass), preferably greater than or equal to 98.0%, and extremely preferably greater than or equal to 99.0%. According to particular embodiments, the trifluoroethylene may have a purity greater than or equal to 99.5%.

[0044] Document EP 2 993 213 shows, for example, the production of a trifluoroethylene with a purity equal to 99.1% comprising as impurities other hydrohalogenated olefins, and in particular chlorotrifluoroethylene, difluoroethylene isomers and chlorodifluoroethylene isomers, as well as alkanes. No aliphatic alkene, the use of which as an inhibitor of polymerization of hydro(halogenated) olefins claimed here, was detected.

[0045] The trifluoroethylene thus produced can be stored in a suitable pressure-resistant container. It is stored in the presence of butene in the gaseous state with a gaseous phase content of 1 ppm molar to 100,000 ppm, preferably 50 ppm to 75,000 ppm, more preferably 100 ppm to 50,000 ppm, even more preferably 500 ppm to 25,000 ppm, and extremely preferably 1000 ppm to 10,000 ppm relative to trifluoroethylene.

[0046] Prior to the introduction of trifluoroethylene and / or butene and / or the composition comprising trifluoroethylene and butene, the dioxygen content within the container can be reduced to a predetermined threshold by reducing the internal pressure and / or injecting an inert gas.

[0047] The composition can be stored under usual conditions of pressure and temperature.

[0048] The storage temperature may vary in particular from -20°C to +40°C, or from -10°C to +35°C or even from 0°C to 30°C.

[0049] The storage pressure is generally greater than or equal to 1 bar, and less than or equal to 20 bars.

[0050] The pressure may in particular be greater than or equal to 1.5 bar or greater than or equal to 2 bar, or greater than or equal to 2.5 bar, or greater than or equal to 3 bar or greater than or equal to 3.5 bar. A pressure of 3.5 bar or more is beyond the recommended pressure threshold for the storage of trifluoroethylene comprising less than 1000 ppm of dipentene in the gas phase (see Safety data sheet for trifluoroethylene marketed by the company Halocarbon - XP002673763)

[0051] The pressure may in particular be less than or equal to 19 bars, or less than or equal at 18 bars, or less than or equal to 17 bars, or less than or equal to 16 bars, or less than or equal to 15 bars.

[0052] According to certain embodiments, the storage pressure is between 3.5 bars and 15 bars. Examples

[0053] In the experiments carried out below, a 99.9% purified trifluoroethylene and butylene of 99.6% purity were used.

[0054] Chromatographic analysis of trifluoroethylene showed that among the impurities present were chlorotrifluoroethylene and vinylidene fluoride as other aliphatic alkenes. Chromatographic analysis also showed that trifluoroethylene did not contain any aliphatic alkenes, and a fortiori no but-1-ene.

[0055] Example 1

[0056] A quantity of 166 g of trifluoroethylene was reacted with a quantity of 280 g of vinylidene fluoride and 17 g of chlorotrifluoroethylene, in the presence of 0.45 g of but-1-ene (i.e. 950 ppm molar relative to the total number of moles of monomers being (hydro)(chloro)fluorinated olefins) in a 4L reactor containing 3400 g of demineralized water, 1 g of methylhydroxypropyl cellulose and 1.8 g of propyl peroxydicarbonate. The reactor was then brought to a temperature of 44°C as quickly as possible to reach a pressure of 95 bars. Once the temperature of 44°C was reached, the polymerization reaction only started after an inhibition period equal to 82 minutes, the reaction being considered to have started after the pressure in the reactor had dropped by 5 bars.

[0057] Comparative example

[0058] The comparative example was carried out under the same conditions as Example 1 except that but-1-ene was not added to the reaction mixture. The reactor was brought to a temperature of 44°C as quickly as possible and the pressure in the reactor once the target temperature was reached was less than 90 bar, which indicates that the polymerization reaction started during the temperature rise in the reactor.

[0059] Thus, but-1-ene is a polymerization inhibitor of trifluoroethylene.

Claims

Claims ^Claim 1] Composition comprising: - at least one (hydro)halogenated olefin having the chemical formula: [Chem. 2] CXtXrfXaX* (1) in which Xi is chosen from F and Cl, and in which X2, X3 and X4 are independently chosen from H, F and Cl; and, - at least one aliphatic alkene, having a boiling point less than or equal to 80°C measured at 1013 hPa; in which the (hydro)halogenated olefin is in gaseous form only or in liquid-gas equilibrium form. ^Claim 2] Composition according to claim 1, in which the (hydro)halogenated olefin of formula (I) is selected from the group consisting of: vinyl chloride, vinyl fluoride, 1,1-dichloroethene, 1,2-dichloroethene, 1,1-difluoroethene, 1,2-difluoroethene, chlorotrifluoroethylene, 1,1-chlorofluoroethene, 1,2-chlorofluoroethene, tetrafluoroethylene.^Claim 3] Composition according to claim 1, in which the (hydro)halogenated olefin of formula (I) essentially comprises an element selected from the group consisting of trifluoroethylene, tetrafluoroethylene, chlorotrifluoroethylene, 1,1-chlorofluoroethene, and their mixture; and preferentially from the group consisting of trifluoroethylene, tetrafluoroethylene, and their mixture. ^Claim 4] Composition according to any one of claims 1 to 3, in which the aliphatic alkene has a boiling point at most equal to 60°C, and preferentially at most equal to 50°C, measured at 1013 hPa.^Claim 5] A composition according to any one of claims 1 to 4, wherein the aliphatic alkene is selected from the group consisting of: propene, 1-butene, 2-butene, isobutylene, 1-pentene, 2-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 2-methyl-2-butene, 1-hexene, 2-hexene, 3-hexene, isomers of methyl-pentene, in particular 4-methyl-1-pentene, isomers of dimethylbutene, cyclopentene, and a mixture thereof. ^Claim 6] A composition according to any one of claims 1 to 5, wherein the aliphatic alkene is selected from the group consisting of: 1-butene, 2-butene, isobutylene and a mixture thereof. ^Claim 7] Composition according to any one of claims 1 to 6, characterized in that the (hydro)halogenated olefin is only in the gaseous state. ^Claim 8] Composition according to any one of claims 1 to 7, in which the aliphatic alkene is in liquid-gas equilibrium. ^Claim 9] Composition according to any one of claims 1 to 8, in which the (hydro)halogenated olefin represents at least 90%, or at least 91%, or at least 92%, or at least 93%, or at least 94%, or at least 95%, or at least 96%, or at least 97%, or at least 98%, or at least 99% by weight relative to the total weight of the composition.^Claim 10] Composition according to any one of claims 1 to 9 comprising more than 100 ppm molar, preferably more than 250 ppm molar, more preferably more than 500 ppm molar, more preferably more than 750 ppm and more preferably more than 1000 ppm molar of said aliphatic alkene in gas phase, relative to the number of moles of (hydro)halogenated olefin in gas phase. ^Claim 11] Composition according to any one of claims 1 to 10 comprising less than 50,000 ppm molar, preferably less than 25,000 ppm molar, and preferably less than 10,000 ppm molar of said aliphatic alkene in gas phase, relative to the number of moles of (hydro)halogenated olefin in gas phase. ^Claim 12] Use of at least one aliphatic alkene, having a boiling point less than or equal to 80°C, measured at 1013 hPa, for stabilizing at least one (hydro)halogenated olefin having the chemical formula: [Chem.3] CXtX2=CXsX4 (0 in which Xi is chosen from F and Cl, and in which X2, X3 and X4 are independently chosen from H, F, and Cl.