Azeotropic composition and azeotropic-like composition

Abstract

To provide an azeotropic composition and an azeotropic-like composition mainly composed of 1,1,1,2,3,3-hexafluoro-3-[2-(1,1,2,3,3,3-hexafluoropropoxy)ethoxy ]propane (HFE-77-12). An azeotropic composition of the present invention contains 95.1 mol% of HFE-77-12 and 4.9 mol% of 1,2,3,3,3-pentafluoro-1-[2-(1,1,2,3,3,3-hexafluoropropoxy)ethoxy ]-1-propene. An azeotropic-like composition of the present invention contains 80.0-97.8 mol% of HFE-77-12 and 2.2-20.0 mol% of 1,2,3,3,3-pentafluoro-1-[2-(1,1,2,3,3,3-hexafluoropropoxy)ethoxy ]-1-propene.

Description

Azeotropic and azeotrope-like compositions

[0001] The present invention relates to azeotropic and azeotrope-like compositions containing hydrofluoroether (HFE) compounds that are useful as heat transfer media and the like.

[0002] Heat transfer media are used in a variety of heat transfer means, such as for controlling the temperature of wafers in semiconductor manufacturing, for cooling and heating semiconductor elements and electronic components, for cooling servers, and for controlling the temperature of heat pumps, heat pipes, and thermostatic baths.

[0003] Conventionally, perfluorocarbons (PFCs) have been widely used as heat transfer media, but PFCs have a problem in that they have a high global warming potential (GWP) and have a large impact on the environment due to the greenhouse effect.

[0004] For this reason, the use of HFEs, which have a smaller impact on the environment, is being studied as an alternative heat transfer medium to PFCs. One known example of an HFE is 1,1,1,2,3,3-hexafluoro-3-[2-(1,1,2,3,3,3-hexafluoropropoxy)ethoxy]propane (hereinafter sometimes abbreviated as HFE-77-12). Patent Document 1 describes that HFE-77-12 can be obtained by a synthesis method in which hexafluoropropene and ethylene glycol are reacted.

[0005] Special Publication No. 2007-524737

[0006] However, the reaction product obtained by the synthesis method described in Patent Document 1 may contain, in addition to the target product HFE-77-12, unreacted raw materials, intermediates, and by-products (for example, compounds of various structures formed by hydrogen fluoride elimination from HFE-77-12). When such a reaction product is used as a heat transfer medium, the heat transfer medium may undergo a change in composition over time. If the heat transfer medium undergoes a change in composition during use, it becomes difficult to stably control the cooling or heating by the heat transfer medium.

[0007] For this reason, the present inventors have investigated various methods for purifying HFE-77-12. During the course of their investigations, they found that a specific component in the mixed product forms an azeotropic or azeotrope-like composition with HFE-77-12. This azeotropic or azeotrope-like composition does not undergo a change in composition, regardless of whether a phase change occurs or not, and is therefore thought to be useful in a variety of applications, including as a heat transfer medium.

[0008] The present invention has been made from this perspective, and an object of the present invention is to provide an azeotropic composition and an azeotrope-like composition containing HFE-77-12 as a main component.

[0009] The present invention is based on the discovery of azeotropic and azeotrope-like compositions formed by combining HFE-77-12 with a specific compound.

[0010] The present invention provides the following means: [1] An azeotropic composition containing 95.1 mol % of 1,1,1,2,3,3-hexafluoro-3-[2-(1,1,2,3,3,3-hexafluoropropoxy)ethoxy]propane and 4.9 mol % of 1,2,3,3,3-pentafluoro-1-[2-(1,1,2,3,3,3-hexafluoropropoxy)ethoxy]-1-propene. [2] An azeotrope-like composition containing 80.0 to 97.8 mol% of 1,1,1,2,3,3-hexafluoro-3-[2-(1,1,2,3,3,3-hexafluoropropoxy)ethoxy]propane and 2.2 to 20.0 mol% of 1,2,3,3,3-pentafluoro-1-[2-(1,1,2,3,3,3-hexafluoropropoxy)ethoxy]-1-propene. [3] A composition having a content of 90 mass% or more of the azeotrope composition of [1] or the azeotrope-like composition of [2]. [4] A heat transfer medium containing the azeotrope composition of [1] or the azeotrope-like composition of [2]. [5] A heat transfer medium which is the composition of [3]. [6] A heat transfer medium of [4] or [5] used for cooling or heating components in semiconductor manufacturing equipment.

[0011] According to the present invention, there is provided an azeotropic composition and an azeotrope-like composition containing HFE-77-12 as a main component. The azeotropic composition and azeotrope-like composition of the present invention can be used stably and continuously as a heat transfer medium.

[0012] The azeotropic composition of an embodiment of the present invention (hereinafter also referred to as the present embodiment) contains 95.1 mol % of HFE-77-12 and 4.9 mol % of 1,2,3,3,3-pentafluoro-1-[2-(1,1,2,3,3,3-hexafluoropropoxy)ethoxy]-1-propene. The azeotropic composition of the present embodiment is as excellent as pure HFE-77-12 in various physical properties required for a heat transfer medium, such as kinematic viscosity, specific heat, freezing point, and breakdown voltage, and can maintain stable properties without any change in composition even when used repeatedly as a heat transfer medium, etc.

[0013] The azeotropic composition is a mixed solution of a specific composition in which the composition of the gas phase and the composition of the liquid phase are the same when the composition is in a gas-liquid equilibrium state, and in this specification refers to a two-component liquid composition that forms an azeotrope under a pressure of 0.101 MPa (1 atm). The azeotropic point of the azeotropic composition of this embodiment at a pressure of 0.101 MPa is 164°C.

[0014] HFE-77-12 has the chemical formula CF ３ CHFCF ２ OCH ２ CH ２ OCF ２ CHFCF ３ HFE-77-12 has a high boiling point of 164°C, but a freezing point below -100°C, and is liquid over a wide temperature range, making it an excellent heat transfer medium.

[0015] 1,2,3,3,3-Pentafluoro-1-[2-(1,1,2,3,3,3-hexafluoropropoxy)ethoxy]-1-propene has the chemical formula CF ３ CF = CFOCH ２ CH ２ OCF ２ CHFCF ３ and is a compound having a structure in which hydrogen fluoride has been eliminated from a fluoroalkyl group bonded to one etheric oxygen atom of HFE-77-12 (hereinafter referred to as the HF-free compound).

[0016] HFE-77-12 has a GWP of less than 50 (estimated value), whereas the HF-free form has a GWP of less than 10 (estimated value), and an azeotropic composition, which is a mixture of the two, has the advantage of having a lower GWP than pure HFE-77-12. Note that GWP is an estimated value obtained by integrating the intensity of the greenhouse effect (radiant energy given to the Earth) per concentration when a target substance is released into the atmosphere over 100 years, with carbon dioxide as the standard value. The GWPs (estimated values) of HFE-77-12 and the HF-free form can be determined based on their chemical structures from the GWP values ​​of known fluorine-based heat transfer media.

[0017] When a mixture of HFE-77-12 and HF-free product is in a gas-liquid equilibrium state, the relative volatility α is expressed by the following formula (1): α=(y １ / y ２ ) / (x １ / x ２ ) (1) In the formula, y １ y: mole fraction of HFE-77-12 in the gas phase ２ : Molar fraction of dehydrogenated form in the gas phase, x １ : mole fraction of HFE-77-12 in the liquid phase, x ２ : Molar fraction of HF-free product in the gas phase

[0018] In the azeotropic composition of this embodiment, α = 1.00. In this specification, a mixture of HFE-77-12 and HF-removed product when α is within the range of 1.00 ± 0.05, i.e., 0.95 ≦ α ≦ 1.05, is referred to as an azeotrope-like composition.

[0019] The azeotrope-like composition of this embodiment contains 80.0 to 97.8 mol % of HFE-77-12 and 2.2 to 20.0 mol % of HF-removed compounds. The total amount of HFE-77-12 and HF-removed compounds in the azeotrope-like composition is 100 mol %. The various physical properties required of a heat transfer medium are not significantly different from those of an azeotropic composition, and even when repeatedly used as a heat transfer medium, the azeotrope-like composition undergoes almost no compositional change, can be handled in the same manner as an azeotropic composition, and can maintain stable properties. In this specification, the compositional proportions of an azeotrope-like composition also include the compositional proportions of an azeotrope composition, and for convenience, an azeotrope-like composition may also be described as including an azeotrope composition. The boiling point of the azeotrope-like composition of this embodiment at a pressure of 0.101 MPa is 163 to 165°C.

[0020] The azeotropic composition or azeotrope-like composition of this embodiment may be obtained by mixing HFE-77-12 and the HF-free substance to form the azeotropic or azeotrope-like composition described above, and the method for producing the composition is not particularly limited. The azeotropic composition or azeotrope-like composition of this embodiment may be obtained by mixing HFE-77-12 and the HF-free substance. HFE-77-12 can be synthesized by a known method, such as an addition reaction of hexafluoropropene with ethylene glycol in the presence of an alkali catalyst such as potassium carbonate. The HF-free substance can be synthesized by, for example, a method in which HFE-77-12 is reacted in the presence of a strong base such as an alkali metal alkoxide to eliminate hydrogen fluoride. Specifically, HFE-77-12 and the HF-free substance can be produced by the methods described in the examples below.

[0021] The composition of this embodiment contains the azeotropic composition or azeotrope-like composition of this embodiment described above at 90% by mass or more. The composition may contain 10% by mass or less of other components in addition to the azeotropic or azeotrope-like composition of HFE-77-12 and the HF-free substance. The amount of other components in the composition is preferably 5% by mass or less, more preferably 3% by mass or less, and may even be 0% by mass. The composition of this embodiment can be obtained by adding and mixing other components, as necessary, with the azeotropic composition or azeotrope-like composition of this embodiment. Examples of other components include fluorine-based solvents and stabilizers.

[0022] Examples of fluorine-based solvents include Galden (registered trademark) HT90 / 110 / 135 / 150 / 200 (all CF ３ - [OCF (CF ３ ) (CF ２ ) ｎ (OCF ２ ) ｍ ]-CF ３ ), ZV90, SVX, ZT-180; FTM-110 / 135 / 150 / 170 / 200 / 230 / 270 manufactured by Sanming Hexafluo Chemicals; Fluorinert (registered trademark) FC-75 (C ８ F ８ ) / 3283 ((C ３ F ７ ) ３ N) / 40 ((C ４ F ９ ) ３ N) / 43 ((C ４ F ９ ) ３ N) / 70 ((C ５ F １１ ) ３ N), FX-3300(C ８ F ８ ), Novec 7100 (CF ３ (CF ２ ) ３ OCH ３ and (CF ３ ) ２ CFCF ２ OCH ３ Mixture of CF ３ (CF ２ ) ３ O.C. ２ H ５ and (CF ３ ) ２ CFCF ２ O.C. ２ H ５ Mixture of CF ３ ) ２ CFCF (CF ２ CF ３ ) OCH ３ ) / 7500 (CF ３ CF ２ CF ２ CF (OCH ２CH ３ )CF(CF ３ )CF ３ ) / 7600 (CF ３ CFHCF ２ OC (CH ３ )CF ２ CFHCF ３ ); Opteon (registered trademark) SF10 / 30 (CF ３ CH=CHCF ３ and CClH = CClH mixture) / 33(CF ３ CH=CHCF ３ ) / 2P50; Asahiklin (registered trademark) AC-2000 (CF ３ CF ２ CF ２ CF ２ CF ２ CF ２ H) / 6000(CF ３ CF ２ CF ２ CF ２ CF ２ CF ２ CH ２ CH ３ ), Amorea (registered trademark) AS-300 (CF ２ HCF = CClH); CELEFIN (registered trademark) 1233Z (CF ３ Examples of commercially available products include DAISAVE (registered trademark) SS-54 manufactured by Daikin Industries, Ltd. and HFE-65-12 manufactured by Daikin Technology Co., Ltd.

[0023] Examples of stabilizers include phenol compounds, unsaturated hydrocarbon group-containing aromatic compounds, aromatic amine compounds, aromatic thiazine compounds, terpene compounds, quinone compounds, nitro compounds, epoxy compounds, and orthoester compounds.

[0024] The heat transfer medium of this embodiment includes the azeotropic composition or azeotrope-like composition of this embodiment described above. It may also be the composition of this embodiment described above. The heat transfer medium preferably satisfies the following physical properties. For example, from the viewpoint of good fluidity, the kinematic viscosity (25°C) is preferably 3.0 x 10 －６ m２ / s or less, more preferably 2.5 × 10 －６ m ２ / s or less, more preferably 2.0 × 10 －６ m ２ / s or less. From the viewpoint of good heat transport efficiency, the specific heat (25°C) is preferably 0.5 kJ / (kg K) or more, more preferably 0.8 kJ / (kg K) or more, and even more preferably 1.0 kJ / (kg K) or more. From the viewpoint of a wide temperature range of application, the freezing point is preferably -40°C or less, more preferably -60°C or less, and even more preferably -80°C or less. From the viewpoint of stable use in a high electric field environment, the breakdown voltage (when the electrode gap is 2.5 mm) is preferably 20 kV or more, more preferably 30 kV or more, and even more preferably 40 kV or more.

[0025] The azeotropic composition, azeotrope-like composition, or composition of this embodiment has a small GWP and can therefore be suitably used in a wide range of applications, such as cleaning agents, solvents, foaming agents, aerosols, working fluids for binary power generation such as heat pipes and for factory waste heat recovery, storage fluids for electronic components, and media for gross leak tests, thermal shock tests, liquid burn-in tests, and voltage resistance tests of electronic components. Specifically, as a cleaning agent, it can also be used to remove contaminants (e.g., reaction products such as silicon oxides generated during the etching process) that accumulate inside the chamber of a dry etching apparatus used in semiconductor manufacturing.

[0026] Specific examples of the heat transfer medium include heat transfer mediums used for controlling the temperature of wafers in semiconductor manufacturing, cooling and heating semiconductor elements and electronic components, cooling servers, heat pumps, heat pipes, thermostatic baths, etc. The heat transfer medium of this embodiment is suitable as a heat transfer medium for cooling or heating components in semiconductor manufacturing equipment, and is also suitable as a heat transfer medium used continuously under harsh conditions of a high electric field and a high-temperature environment, such as in a dry etching process using thermal plasma in semiconductor manufacturing.

[0027] The present invention will be specifically described below based on examples, but the present invention is not limited to the following examples. The reaction product was identified by proton nuclear magnetic resonance (１ H NMR) spectrum, fluorine-19 nuclear magnetic resonance ( １９ F NMR) spectrum and gas chromatography mass spectrometry (GC-MS (column used: "DB-1301", length 60 m, inner diameter 250 μm, thickness 1 μm; manufactured by Agilent Technologies, Inc.)).

[0028] [Synthesis of HFE-77-12] 223 g of potassium carbonate (manufactured by Junsei Chemical Co., Ltd.), 200 g of ethylene glycol (manufactured by Junsei Chemical Co., Ltd.), and 400 g of anhydrous acetonitrile (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were placed in a stainless steel autoclave (internal volume 2.1 liters) equipped with a stirrer, and the mixture was kept sealed and at 20 ° C. The contents of the autoclave were stirred, and 966 g of hexafluoropropene (manufactured by AGC Inc.) was added in a gaseous state over 6 hours. After maintaining the mixture at 20 ° C. for 1 hour to allow the reaction, the reaction crude liquid in the autoclave was recovered by filtration. The recovered reaction crude liquid contained 45% by mass of HFE-77-12 and a by-product of hydrogen fluoride detached from HFE-77-12. Next, 1000 g of the reaction crude liquid was placed in a Hastelloy (registered trademark) autoclave (internal volume 2.1 liters), and 100 g of anhydrous hydrogen fluoride (manufactured by AGC Corporation) was added and stirred for 1 hour. The resulting reaction crude liquid was phase-separated, washed with water, dried over molecular sieve 3A (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and then purified by distillation to obtain HFE-77-12.

[0029] [Synthesis of HF-free product] 117 g of tert-butyl alcohol (manufactured by Kanto Chemical Co., Inc.) and 75 g of HFE-77-12 were placed in a glass reactor (internal volume: 0.5 liters) equipped with a stirrer, and the mixture was heated to 40°C with stirring, and 100 g of potassium tert-butoxide (manufactured by Tokyo Chemical Industry Co., Ltd.) was added intermittently over 5 hours. The mixture was maintained at 40°C for 2 hours to allow the reaction to proceed, and the reaction crude liquid was neutralized with a 10% by mass aqueous potassium bicarbonate solution and washed with water. The organic layer was recovered and purified by distillation to obtain a HF-free product.

[0030] [Measurement of Gas-Liquid Equilibrium] The HFE-77-12 and HF-free derivative synthesized above were placed in a 500 mL autoclave equipped with a pressure gauge at the respective molar fractions shown in the liquid phase of Examples 1 to 7 in Table 1, and the autoclave was maintained at 0.101 MPa (1 atm) and 170°C for 24 hours to stabilize. Samples were taken from the gas phase and liquid phase in the autoclave, and the composition ratios (molar fractions) of HFE-77-12 and HF-free derivative were measured by gas chromatography analysis, and the relative volatility was calculated. Table 1 shows the compositions of the liquid phase and gas phase, as well as the relative volatility, of each Example. In the table, Examples 2 to 5 are working examples, and Examples 1, 6, and 7 are comparative examples.

[0031]

[0032] As shown in Table 1, as the proportion of HF-free products in the liquid phase increases, the relative volatility of HFE-77-12 increases, and when the HFE-77-12 content was 95.1 mol % and the HF-free products content was 4.9 mol %, the relative volatility was 1.00, and the compositions of the liquid and gas phases were the same, confirming an azeotropic composition (Example 3). Furthermore, when the molar ratio of HFE-77-12 to HF-free products in the liquid phase was 80.0 / 20.0 to 97.8 / 20.0, the relative volatility was within the range of 1.00±0.05, confirming an azeotrope-like composition (Examples 2, 4, and 5).

[0033] [Evaluation of Physical Properties] The kinematic viscosity, specific heat, freezing point, and breakdown voltage of the azeotropic composition of HFE-77-12 and the HF-removed product (Example 3), and HFE-77-12 were measured. The kinematic viscosity was determined by measuring the viscosity at 25°C using an EMS (electromagnetic spinning) viscometer ("EMS-1000", manufactured by Kyoto Electronics Manufacturing Co., Ltd.) and dividing the value by the density. The specific heat was measured at 25°C using a differential scanning calorimetry (DSC) device ("DSC 8500", manufactured by PerkinElmer). The breakdown voltage was measured using a dielectric breakdown tester ("YST-243AT-B100", manufactured by Yamayo Test Instruments Co., Ltd.; electrode gap 2.5 mm) in accordance with JIS C 2101:2100.

[0034] As a result of the measurement, the azeotropic composition of HFE-77-12 and the HF-removed product (Example 3) and HFE-77-12 both had a kinematic viscosity (25°C) of 1.68 × 10 －６m ２ The kinematic viscosity, specific heat (25°C) was 1.23 kJ / (kg·K), the freezing point was less than -100°C, and the breakdown voltage was 53 kV. From this, it can be said that the azeotropic composition has no difference in kinematic viscosity, specific heat, freezing point, or breakdown voltage compared to pure HFE-77-12, and can be suitably used as a heat transfer medium, similar to HFE-77-12. There is also no significant difference in these physical properties for the azeotrope-like composition, and it can be suitably used as a heat transfer medium. It was confirmed that the azeotropic composition of Example 3 can be used without problem, even when circulated as a heat transfer medium at a controlled temperature of 100°C in a semiconductor manufacturing device equipped with a mechanism for circulating a heat transfer medium.

Claims

1. An azeotropic composition containing 95.1 mol% of 1,1,1,2,3,3 - hexafluoro - 3 - [2 - (1,1,2,3,3,3 - hexafluoropropoxy)ethoxy]propane and 4.9 mol% of 1,2,3,3,3 - pentafluoro - 1 - [2 - (1,1,2,3,3,3 - hexafluoropropoxy)ethoxy] - 1 - propene.

2. An azeotrope - like composition containing 80.0 to 97.8 mol% of 1,1,1,2,3,3 - hexafluoro - 3 - [2 - (1,1,2,3,3,3 - hexafluoropropoxy)ethoxy]propane and 2.2 to 20.0 mol% of 1,2,3,3,3 - pentafluoro - 1 - [2 - (1,1,2,3,3,3 - hexafluoropropoxy)ethoxy] - 1 - propene.

3. A composition in which the content of the azeotropic composition according to claim 1 or the azeotrope - like composition according to claim 2 is 90% by mass or more.

4. A heat medium containing the azeotropic composition according to claim 1 or the azeotrope - like composition according to claim 2.

5. A heat medium which is the composition according to claim 3.

6. The heat medium according to claim 4 or 5, which is used for cooling or heating a constituent member in a semiconductor manufacturing apparatus.

Images