JP2002544248A - Production of 1,1,1,2,3,3,3-heptafluoropropane - Google Patents

Abstract

(57) [Abstract] This is a method for producing HFC227ea by reacting HFP with hydrogen fluoride. The reaction mixture from these is charged into a liquid phase separator, and the HFC227ea-rich phase and hydrogen fluoride-rich phase are charged. Separating the phases under gravity, recirculating the separated hydrogen fluoride-enriched phase, charging the HFC227ea-enriched phase to a distillation column, recovering the HFC227ea and HF-enriched mixture separately from the distillation column, A method for producing HFC227ea, comprising the step of recycling an HF-enriched mixture to a reactor.

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a process for producing 1,1,1,2,3,3,3-heptafluoropropane from hexafluoropropene and to 1,1,1,2,3,3,3-heptafluoropropane The present invention relates to a method for separating a mixture containing hydrogen fluoride.

[0002] Hydrofluorocarbons are widely used as substitutes for chlorofluorocarbon compounds in various applications. Such uses include, for example, use as aerosol propellants in medical applications, use as a fire extinguishing agent, use in cooling applications, and in other uses. 1,1,1,2,3,3,3-heptafluoropropane, which is technically known as hydrofluorocarbon 22ea and is hereinafter referred to as "HFC227ea" for convenience, has zero ozone depletion capacity, and has low toxicity and nonflammability It is particularly beneficial for medical applications in view of its combination of properties, including properties, solvent properties and boiling point.

[0003] It is known to produce hydrofluorocarbons by hydrofluorination of fluoroalkenes in the liquid phase or in the gas phase, optionally in the presence of a catalyst, to the corresponding hydrofluoroalkanes. Hydrogen fluoride is known for use as a hydrofluorinating agent in such hydrofluorination processes.

In such a hydrofluorination method, various materials can be used as a catalyst.

For example, in the gas phase reaction between hexafluoropropene and hydrogen fluoride, hereinafter referred to as “HFP” for convenience in producing HFC227ea, German Patent No. 2712732 and British Patent No. 902590 each disclose oxyfluorene. It discloses the use of chromium hydride catalysts and activated carbon catalysts.

[0006] The description of the above patent specification is incorporated herein by reference.

In the above reaction method, hydrogen fluoride is usually used in excess of stoichiometry with respect to HFP,
The conversion of FP to HFC227ea, if any, depends on the catalyst used and the conditions of the reactor performing the conversion.

[0008] The product stream leaving the reactor typically contains HFC227ea, HFP, hydrogen fluoride and their ternary azeotropes.

It is common practice to recover as much hydrogen fluoride from the product stream from such hydrofluorination reactions as possible for reuse. This can be achieved in part by distillation. However, if the HFC227ea / hydrogen fluoride azeotrope or azeotrope-like mixture and the HFP / hydrogen fluoride azeotrope or azeotrope-like mixture are present in the product stream,
It limits the extent to which hydrogen fluoride can be separated from fluoroorganic compounds by simple distillation.

[0010] The product stream containing the HFC227ea / hydrogen fluoride azeotrope and the HFP / hydrogen fluoride azeotrope is obtained by recovering a part of the hydrogen fluoride by distillation, washing with water, It is known that both a mixture of organic compounds substantially free of and aqueous hydrogen fluoride can be recovered. However, such treatment is uneconomic for hydrogen fluoride. This is because the aqueous hydrogen fluoride thus produced is usually neutralized with caustic solution and / or lime and finally discarded.

[0011] Alternatively, after recovering a portion of the hydrogen fluoride by distillation, the product stream from the reaction of the fluoroalkene with the hydrogen fluoride is transferred to WO 97
/ 13179, can be treated with a solution of an alkali metal dissolved in anhydrous hydrogen fluoride. However, although such a method recovers hydrogen fluoride for reuse in the process, it has the disadvantage of requiring additional equipment.

Further, when producing a fluorine-containing organic compound by reacting a haloalkene with hydrogen fluoride, the haloalkene / hydrogen fluoride azeotrope can be separated from the fluorine-containing compound / hydrogen fluoride azeotrope by fractional distillation. It is known that hydrogen fluoride can be removed from a fluorine-containing organic compound / hydrogen fluoride azeotrope by treatment with water. However, treating the fluorine-containing organic compound / hydrogen fluoride azeotrope with water to remove water from the azeotrope involves expensive equipment and is uneconomic for hydrogen fluoride.

[0013] Water washing is one effective way to remove hydrogen fluoride from organic compounds after the reaction of the hydrogen fluoride with the haloalkene, but aqueous washing is viewed in terms of the loss of hydrogen fluoride from the process. It will be appreciated that they tend to be expensive. Preferably as much of the hydrogen fluoride as possible, more preferably substantially all of the hydrogen fluoride, is separated from the product stream prior to the aqueous wash, particularly preferably avoiding the aqueous wash.

In the international patent application GB 98/03408 of the applicant's application,
In producing a fluorine-containing organic compound by a reaction between a haloalkene and hydrogen fluoride, for example, in producing HFC227ea from HFP, a haloalkene / hydrogen fluoride azeotrope produces a fluorine-containing organic compound / fluorine azeotrope. If it is more volatile, ie has a lower boiling point, than the hydrogen fluoride azeotrope, both the fluorine-containing organic compound substantially free of hydrogen fluoride and the haloalkene / hydrogen fluoride azeotrope And that the haloalkene can be separated by charging the distillation column and distilling the resulting mixture.

According to the findings of the present inventors, surprisingly, in producing HFC227ea by reacting HFP with hydrogen fluoride, the reaction product undergoes phase separation in a liquid phase. HF
An organic-enriched phase containing C227ea and HFP and a hydrogen fluoride-enriched phase are provided. The molar fraction of HF and 227ea in the reaction product can be from about 0.1 to 0.9.

Further, according to the findings of the present inventors, the addition of HFP to a reaction product in a liquid phase promotes the phase separation.

According to the gist of the first invention, in a method for producing HFC227ea by reacting HFP with hydrogen fluoride, the following steps are required: B. Charge the reaction mixture from the reaction of HFP with hydrogen fluoride to a liquid phase separator and separate the organic phase and the hydrogen fluoride-enriched phase under gravity; B. Recycle the hydrogen fluoride enriched phase separated in step A to the reactor where the reaction takes place; Charging the organic-enriched phase separated in step A into a distillation column; E. recovering the HFC227ea and the hydrogen fluoride enriched mixture separately from the distillation column of step (C); There is provided a process for producing HFC227ea, comprising recycling the hydrogen fluoride-enriched mixture recovered from Step D to a reactor.

The reaction mixture charged to the liquid phase separator in step (A) contains HFC227ea / HF azeotrope or azeotrope-like mixture and optionally HFP / HF azeotrope or azeotrope-like mixture Is preferred.

The reaction mixture charged to the liquid phase separator in step A can be a mixture (direct mixture) directly coming from a reactor in which HFP is reacted with hydrogen fluoride. However, the mixture charged to the liquid phase separator is essentially HFC2 obtained, for example, from the distillation of the mixture directly.
It is often preferred to be the 27ea / hydrogen fluoride azeotrope.

Although the use of the HFC227ea / HF azeotrope or azeotrope-like mixture in the process of the present invention does not promote the separation of the organic phase from the hydrogen fluoride-enriched phase, such use is per pass (per pass It will be appreciated that increasing the amount of HFC227ea removed and thus reducing the amount of material recycled.

It has been surprisingly found by the inventors that the addition of HFP results in the addition of HFC227ea
/ Promotes separation of hydrogen fluoride azeotrope into its components. HFP can be introduced into the method of the invention at one or more suitable points. For example, the HFP can be charged to the reactor and / or to the liquid phase separator of Step A and / or to the distillation column of Step C. Preferably, HFP is added directly or mixed with the reaction mixture to the liquid phase separator.

In the method according to the first aspect of the present invention, the reaction between HFP and hydrogen fluoride can be performed in a liquid phase or a gas phase.

To promote separation in step A of the method according to the first aspect of the present invention, step A is preferably performed at room temperature or lower, typically at 30 ° C. or lower.

To facilitate the separation in step A of the method according to the first aspect of the invention, step A is preferably carried out under superatmospheric pressure, typically at 1 to 20 bar, preferably at about 10 bar.

In a first embodiment of the method according to the first aspect of the present invention, the reaction product of HFP and hydrogen fluoride is distilled and a portion of the hydrogen fluoride is recovered therefrom before HFC227ea
The H / H2O azeotrope or azeotrope-like mixture thereof, the HFP / H2O azeotrope or the azeotrope-like mixture thereof, and the mixture containing hydrogen fluoride are charged to the liquid phase separator of Step A. Enter.

A part of the hydrogen fluoride recovered by distillation in the recovery step before the step A is preferably recycled to the reactor vessel when such a recovery step is performed.

In a second embodiment of the method according to the first aspect of the invention, the reaction product of HFP and hydrogen fluoride is charged directly to the liquid phase separator of step A.

When the HFC227ea is produced by reacting HFP with hydrogen fluoride in the liquid phase in the presence of a catalyst such as TaF ₅ , NbF ₅ or SbF ₅ by the method according to the first aspect of the present invention, At a temperature in the range of from 20 to 200 ° C., preferably from 40 to 120 ° C., especially from 50 to 100 ° C. Suitably, the reaction is conducted at a pressure above atmospheric pressure so that the reactants are in the liquid phase for a time sufficient to produce HFC227ea. The pressure is preferably at least 5 bar, more preferably between 10 and 50 bar.

In the method according to the first aspect of the present invention, the residence time in the reactor is reduced by HFC227e.
It is enough time to be able to convert to a. The required residence time depends inter alia on the conversion required, the proportions of the reactants and the reaction conditions.

If low conversion of HFP to HFC227ea is desired, it is preferred to recycle the feed to increase the yield of HFC227ea from the feed. However, this does not exclude the possibility of using recirculation when high conversions are required in a single pass.

In the method of the present invention, the molar ratio of hydrogen fluoride (HF) to HFP supplied to the reactor is suitably at least 1: 1, preferably 1.2 to 10: 1. . 0.
It will be appreciated that lower conversions and / or yields will be obtained when using a molar ratio of HF to HFP of 1: 1: 1.

In the method of the present invention, the molar ratio of HFP to the catalyst is suitably not more than 100: 1, and is preferably from 1: 1 to 50: 1.

In the process of the present invention, the concentrations of HF, HFP and catalyst are suitably chosen such that the catalyst and the reactants are at least largely dissolved in the liquid phase under the reaction conditions employed.

The process of the present invention can be operated in batch or continuous mode as desired. A semi-batch operation in which one or more feeds are continuously fed to the process and one or more additional feeds are fed to the process in a batch manner may also be used.

[0035] Alternatively, the method of the present invention may be performed in the gas phase. Suitable conditions and catalysts for carrying out the process of the invention in the gas phase are described in detail in the aforementioned German Patent No. 2712732 and British Patent No. 902590.

The present invention is further described with reference to the accompanying drawings, which illustrate, by way of example only, a schematic representation of an apparatus (plant) for performing the method of the invention.

In the drawings, FIG. 1 is a schematic diagram of a plant for supplying HFP to a liquid phase separator; FIG. 2 is a schematic diagram of a plant for supplying HFP to a reactor; FIG. FIG. 4 is an illustration of a plant that feeds directly to a phase separator; FIG. 4 is a ternary diagram illustrating the separation of HFC227ea, HFP and HF.

In FIGS. 1 and 2, the feed pipe (1) leads to a reactor (2), possibly containing a fluorination catalyst. The product tube (3) from the reactor (2) is in fluid flow communication with the first distillation column (4), which is, for example, a single-stage flash vessel. The distillation column (4) typically has a bottom temperature of 100 ° C and a top temperature of about 50 ° C
Operated at a pressure of 12 bar. The bottom pipe (5) from the distillation column (4) is in fluid flow communication with the feed pipe (1). The top (upper) line (6) from the distillation column (4) is a liquid phase separator (
7) is in fluid communication with The top line (8) from the liquid phase separator (7) is the supply line (1)
And fluid flow communication. A bottom (lower) line (9) from the liquid phase separator (7) is in fluid flow communication with a second distillation column (10), which is, for example, a packed column. The distillation column (10) typically has a top temperature of 37 ° C. and a bottom temperature of about 60 ° C.
Operated at a pressure of 12 bar. The distillation column (10) is provided with an outlet pipe (11) for the product and a top pipe (12).

In FIG. 1, the top pipe (12) from the distillation column (10) is in fluid flow communication with the top pipe (6) provided with the supply pipe (13).

In FIG. 2, the top tube (12) from the distillation column (10) is in fluid flow communication with the supply tube (1) provided with the supply tube (13).

In operation, in FIGS. 1 and 2, fresh hydrogen fluoride and recycled hydrogen fluoride (lines (5) and (8)) were passed through feed line (1) to reactor (2). From
In FIG. 2, a feed stream containing (from line (12)) is charged. The product from the reactor (2) containing HFC227ea, often in the form of a ternary azeotrope, hydrogen fluoride and unconverted HFP, passes through the product tube (3) to the first distillation column. Proceed to (4). In the distillation column (4), the hydrogen fluoride recycled to the feed line (1) via the bottom line (5) is HF
Separated from a mixture of C227ea, hydrogen fluoride and unconverted HFP. The mixture of HFC227ea, residual hydrogen fluoride and HFP is fed to the liquid phase separator (7) from the distillation column (4) via the top line (6). The liquid phase separator (7) typically operates at 0-20 ° C to give better separation. In FIG. 1, HFP is supplied to a liquid phase separator (7) through a supply line (13).
). In FIG. 2, HFP is supplied to the reactor (2) via a line (13) and a supply line (1). In the liquid phase separator (7), the HF-enriched phase separates from the organic-enriched phase. The HF-enriched phase is returned to the feed line (1) via the top line (8). The organic-enriched phase flows into the distillation column (10) via the bottom line (9). The HFP of the fluid stream entering the distillation column via line (9) and the fluid stream containing substantially all of the hydrogen fluoride content are passed via line (12) to the distillation column (10). The product stream HFC227ea is withdrawn from the bottom of the distillation column (10) via an outlet pipe (11).

In FIG. 3, the supply pipe (1) is in communication with a reactor (2), possibly containing a fluorination catalyst. A supply line (13) is provided in a line (14) from the reactor (2), and the line (14) is in fluid flow communication with the liquid phase separator (7). Liquid phase separator (7)
The top line (8) is in fluid flow communication with the supply line (1). The bottom line (9) from the liquid phase separator (7) is in fluid flow communication with a distillation column (10), for example a packed column.
The distillation column (10) typically has a top temperature of 37 ° C and a bottom temperature of
Operated at bar pressure. The distillation column (10) has an outlet pipe (11) for product and a top pipe (
12), and the top tube (12) is in fluid flow communication with a line (14) to a liquid phase separator (7).

In operation, in FIG. 3, the reactor (2) contains fresh hydrogen fluoride via the feed line (1) and hydrogen fluoride recycled from line (8). Charge the feed stream. The product from the reactor (2), which contains HFC227ea, often in the form of a ternary azeotrope, hydrogen fluoride and unconverted HFP, passes through a product tube (14) to a liquid phase separator. (7)
Proceed to The HFP is supplied via a feed line (13) and a product line (14) to a liquid phase separator (7
). The liquid phase separator (7) typically operates at 0-20 ° C to give better separation. In the liquid phase separator (7), the HF-rich phase is separated from the organic-rich phase. The HF-enriched phase is returned to the feed line (1) via the top line (8). The organic-enriched phase flows into the distillation column (10) via the bottom line (9). Distillation tower (10) via line (9)
A fluid stream containing the HFP of the incoming fluid stream and substantially all of the hydrogen fluoride content is withdrawn from the top of the distillation column (10) via line (12) and ) To the liquid phase separator (7). The product stream, HFC227ea, is removed from the bottom of the distillation column (10) via the outlet pipe (11).

In the ternary diagram of FIG. 4, the compositions in the area of the figure designated A are phase separated, ie, 0.4-0.6 mol% HF, 0.4 mol% or more HFP and 0.6 mol% or less. The composition containing HFC227ea undergoes phase separation.

The present invention is further illustrated by the following examples.

Examples 1-4 These Examples 1-4 illustrate the liquid phase separation of HFP227ea from HF and HFC in the presence of HFP.
Figure 2 illustrates the accelerated separation of 227ea.

In this example, HFC227ea and HFP, if used, are added to HF in a 500 ml white bomb cooled with liquid nitrogen. The whitish cylinder is equipped with a double dip device so that the dip tube samples from the middle of each phase. The mixture was allowed to warm to room temperature, stirred, left for 2 hours, and then analyzed.

A portion (10 g) of the HF phase was transferred to a smaller, whitish cylinder containing water,
Phase F was analyzed for organic content. The HF phase is left for 15 minutes, then the headspace is analyzed by GC.

The organic phase was analyzed for HF by bubbling off a portion of the organic phase through a water washer (scrubber) containing fresh deionized water and ice. The water was then analyzed for fluoride.

The results are shown in the following table, from which (a) the mixture of HFC227ea and HF contains the organic phase and HF
The phases were separated such that an enriched phase was formed (Example 1) and (b) HFC227ea / HF
Addition of HFP to the mixture reduces the concentration of HF in the organic phase and HFC227ea in the HF phase
Is significantly reduced (Examples 2 to 4).

[0051]

[Brief description of the drawings]

FIG. 1 is an illustrative view of a plant that supplies HFP to a liquid phase separator.

FIG. 2 is an illustrative view of a plant for supplying HFP to a reactor.

FIG. 3 is an illustrative view of a plant that directly supplies a reaction product to a liquid phase separator.

FIG. 4 is a ternary chart illustrating separation of HFC227ea, HFP and HF.

[Procedural Amendment] Submission of translation of Article 34 Amendment

[Submission date] May 22, 2001 (2001.5.22)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Contents of correction]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0022

[Correction method] Change

[Contents of correction]

The reaction between HFP and hydrogen fluoride can be carried out in the liquid or gas phase.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0023

[Correction method] Change

[Contents of correction]

To facilitate the separation in step A of the method of the present invention, step A is preferably performed at room temperature or lower,
Typically, it is performed at 30 ° C. or lower.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0024

[Correction method] Change

[Contents of correction]

To facilitate the separation in step A of the process of the invention, step A is preferably carried out under superatmospheric pressure, typically at 1 to 20 bar, preferably at about 10 bar.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0025

[Correction method] Change

[Contents of correction]

The reaction product of HFP and hydrogen fluoride can be distilled to recover a portion of the hydrogen fluoride therefrom, and then the HFC227ea / hydrogen fluoride azeotrope or an azeotrope-like mixture thereof, The HFP / hydrogen fluoride azeotrope or azeotrope-like mixture thereof and the mixture containing hydrogen fluoride are charged to the liquid phase separator of Step A.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0027

[Correction method] Change

[Contents of correction]

[0027] Alternatively, the reaction product of HFP and hydrogen fluoride can be charged directly to the liquid phase separator of Step A.

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Contents of correction]

When HFC227ea is produced by reacting HFP with hydrogen fluoride in the liquid phase in the presence of a catalyst such as TaF ₅ , NbF ₅ or SbF ₅ , suitably a temperature in the range of 20 to 200 ° C. And preferably at 40 to 120 ° C, especially at 50 to 100 ° C. Reactant reacts and HFC227ea
The reaction is suitably carried out at a pressure above atmospheric pressure so as to be in the liquid phase for a time sufficient to produce The pressure is preferably at least 5 bar, more preferably between 10 and 50 bar.

[Procedure amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0029

[Correction method] Change

[Contents of correction]

[0029] Sufficient residence time in the reactor is required to be able to convert the HFP feed to HFC227ea. The required residence time depends inter alia on the conversion required, the proportions of the reactants and the reaction conditions.

[Procedure amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0031

[Correction method] Change

[Contents of correction]

The molar ratio of hydrogen fluoride (HF) to HFP supplied to the reactor is suitably at least 1: 1 and preferably 1.2 to 10: 1. It will be appreciated that lower conversions and / or yields will be obtained when using a molar ratio of HF to HFP of 0.1 to 1: 1.

[Procedure amendment 10]

[Document name to be amended] Statement

[Correction target item name] 0032

[Correction method] Change

[Contents of correction]

The molar ratio of HFP to the catalyst is suitably not more than 100: 1, preferably from 1: 1 to 50: 1.

[Procedure amendment 11]

[Document name to be amended] Statement

[Correction target item name] 0035

[Correction method] Change

[Contents of correction]

[0035] Alternatively, the reaction of HFP with HF can be performed in the gas phase. Suitable conditions and catalysts for carrying out the reaction of HFP with HF in the gas phase are described in detail in the aforementioned German Patent No. 2712732 and British Patent No. 902590.

[Procedure amendment 12]

[Document name to be amended] Statement

[Correction target item name] 0044

[Correction method] Change

[Contents of correction]

In the ternary diagram of FIG. 4, the composition in the region indicated by A is phase-separated, ie, 0.4 to 0.6 mole fraction of HF, 0.4 mole fraction or more of HFP and 0.6 mole fraction of HFP. HFC227e below rate
The composition containing a undergoes phase separation.

──────────────────────────────────────────────────続 き Continuation of front page (81) Designated country EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE ), OA (BF, BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, KE, LS, MW, SD, SL, SZ, TZ, UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AE, AG, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, CA, CH, CN, CR, CU, CZ, DE, DK, DM, DZ, EE, ES, FI, GB, GD, GE, GH, GM, HR , HU, ID, IL, IN, IS, JP, KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MA, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TR, TT, TZ, UA, UG, US, UZ, VN, YU, ZA , ZW (72) Inventors Summers, Greg, Lindron Lancaster L.A. 15 B.J., Roosevelt Ave. 3F Term (Reference) 4D076 AA12 AA22 BB08 EA12Y EA14Y EA20Z FA11 HA15 JA03 4G075 AA03 AA03 CA05BA053 AA02 AB80 AD11 BC40 BC51 BC52 BD33 BD40 BD52 BD60 BD80 BD84

Claims (7)

[Claims] 1. A method for producing HFC227ea by reacting HFP with hydrogen fluoride, comprising the following steps: B. Charge the reaction mixture from the reaction of HFP with hydrogen fluoride to a liquid phase separator and separate the organic phase and the hydrogen fluoride-enriched phase under gravity; B. Recycle the hydrogen fluoride enriched phase separated in step A to the reactor where the reaction takes place; Charging the organic-enriched phase separated in step A into a distillation column; E. recovering the HFC227ea and the hydrogen fluoride enriched mixture separately from the distillation column of step (C); A process for producing HFC227ea, comprising recycling the hydrogen fluoride-enriched mixture recovered from Step D to a reactor. 2. The reaction mixture charged to the liquid phase separator in step (A) is HFC227ea / H
2. The method according to claim 1, comprising an azeotrope or an azeotrope-like mixture. 3. The method according to claim 1, wherein in step A, the organic phase and the hydrogen fluoride-enriched phase are separated under room temperature or under gravity. 4. The method according to claim 1, wherein in step A, the organic phase and the hydrogen fluoride-enriched phase are separated under gravity under superatmospheric pressure. 5. The method according to claim 1, wherein the HFP is charged into a liquid phase separator. 6. The method according to claim 1, wherein the HFP is charged to the reactor. 7. The mixture to be separated by the liquid-phase separator in the step (A) is 3: 7 to 6: 4 H
The method according to any one of claims 1 to 6, comprising a molar ratio of F: HFC227ea.