JP2589917B2 - 1,1-Difluoroethyl methyl ether, method for producing the same, and working fluid containing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel compound, 1,1-difluoroethyl methyl ether, a process for producing the same, and a working fluid containing the same. More specifically, the present invention is a novel compound which does not contain chlorine atoms and thus does not decompose ozone in the ozone layer.
The present invention relates to 1-difluoroethyl methyl ether, a method for producing the same, and a working fluid containing the same for use in a refrigerator or a heat pump.

[0002]

2. Description of the Related Art As working fluids, chlorofluorocarbons, hydrofluorocarbons and azeotropic compositions thereof have been well known. For example, as a working fluid for a refrigerator, trichlorofluoromethane (CFC 1) is used.
1), dichlorodifluoromethane (CFC 12) and the like are mainly used. As a working fluid for a compression heat pump, 1,2-dichloro-1,1,2,2-tetrafluoroethane (Freon 114) and the like are well known. These fluorocarbons have been used in a wide range of fields because of their nonflammability, low toxicity, stability, and excellent thermodynamic properties as working fluids.

[0003]

However, such fluorocarbons containing chlorine atoms in their molecules reach the stratosphere when released into the atmosphere and destroy the ozone layer in the stratosphere. As a result, it has been pointed out that it has serious adverse effects on ecosystems on earth, including humans. Therefore, it is internationally determined that the production of chlorofluorocarbon which decomposes ozone in the ozone layer is prohibited. Such Freon includes Freon 11, Freon 12, and Freon 114 described above. The ban on CFC production, whose demand has been increasing every year with the spread of refrigeration and air-conditioning equipment, has a great effect on the present society as a whole, including the living environment. Therefore, the development of a new refrigerant that does not destroy the ozone layer is an urgent issue, but no excellent alternative has yet been found.

The present invention has been made in view of the above circumstances, and eliminates the drawbacks of conventional CFCs which cause destruction of the ozone layer by containing chlorine, and has excellent thermodynamic properties. It is an object of the present invention to provide a new working fluid having

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that fluorine-containing ethers,
In particular, they have found that 1,1-difluoroethyl methyl ether, which is a novel compound, has requirements meeting its purpose, and as a result of intensive studies on its production method, it has been found that 1,1-difluoroethylene and methanol The inventors have found that the compound can be synthesized at a relatively good conversion rate and with high selectivity by the reaction with, and the present invention has been completed.

Conventionally, methods for producing fluorine-containing ethers can be broadly classified into a method of fluorinating an ether compound and a method of reacting a compound containing a fluorine atom by various methods to form an ether compound. The former describes direct fluorination of ether compounds with fluorine gas (A. Sekiya et al., Chem. Let.
t. , 1990 , 609; J. Lagow
et al. , J. et al. Org. Chem. , 1988 , 5
3,78), indirect fluorination using a metal fluoride of an ether compound or the like (M. Brandwood et al., J.F.
fluorine Chem. , 1975 , 5,52
1), electrolytic fluorination of ether compounds (T. Abe et al.)
al. , J. et al. Fluorine Chem. , 198
0 , 15, 353).

The addition reaction of alcohols to fluorinated olefins (RD Chambers et al., A
dv. Fluorine Chem. , 1965 , 4,
50), Reaction of alcohol with alkyl halide (J.
A. See Young et al. , J. et al. Am. Chem.
Soc. , 1950 , 72, 1860), reaction of a fluorinated alcohol with a sulfonic acid ester (UK Patent Specification No. 813,493), reaction of an acid fluoride with a sulfonic acid ester (German Patent Specification No. 1294949), etc. A variety of reactions are known. However, 1,1-
Difluoroethyl methyl ether has not been synthesized by any method so far.

The inventors of the present invention have conducted intensive studies on the synthesis method, and as a result, it has been found that the reaction of 1,1-difluoroethylene with methanol provides 1,1-difluoroethyl methyl with relatively good conversion and high selectivity. It has been found that ether can be synthesized.

Although the reaction of the present invention proceeds without a catalyst,
The use of a catalyst proceeds more efficiently. As the catalyst, a basic catalyst is preferable, and sodium, sodium hydroxide, potassium hydroxide and the like are particularly preferable. The amount used is not particularly limited, but may be selected from the range of 0.001 to 5 times, preferably 0.01 to 1.5 times the mol of methanol as one of the raw materials. preferable. When the amount is less than 0.001 mol, the progress of the reaction is slow, while when the amount is more than 5 times the amount of by-products increases.

The proportion of 1,1-difluoroethylene and methanol used in the reaction of the present invention is not particularly limited, and the reaction can be carried out at any rate. In order to improve the yield, the reaction is preferably performed with excess methanol.

In the reaction of 1,1-difluoroethylene with methanol of the present invention, the reactivity can be increased by using a solvent. Preferred solvents include methanol as one of the raw materials and 1,1-difluoroethyl methyl ether as a product, and chain ethers such as diethyl ether and dimethoxyethane, and cyclic ethers such as dioxane. And amines such as N, N-dimethylformamide, carbonyl compounds such as acetone, aromatic hydrocarbons such as benzene and toluene, pyridine, and liquid ammonia. They can be used alone or as a mixture of two or more. The amount used is not particularly limited, and the reaction can be carried out in any amount.

The pressure in the reaction of the present invention is not particularly limited, and the reaction proceeds at any pressure from reduced pressure to increased pressure. When the reaction is performed under pressure, the pressure is not particularly limited, but it is 50 kg / cm from the viewpoint of operability and the like.
It is preferably at most ² G.

The reaction temperature in the reaction of the present invention varies depending on the reaction pressure, the amount of catalyst and the like, but is usually selected from the range of 0 to 200 ° C, preferably 20 to 100 ° C.

The reaction time in the reaction of the present invention varies depending on the reaction temperature, reaction pressure, amount of catalyst, etc., but the reaction is almost completed within several hours to several tens of hours.

The 1,1-difluoroethyl methyl ether of the present invention can be used for various uses such as a foaming agent and an aerosol, similarly to the conventional Freon. Particularly, as the working fluid, the conventional Freon 11, Freon 12, and Freon 114 are used. It is a very useful alternative.

The main physical properties of the 1,1-difluoroethyl methyl ether of the present invention are as follows.

Boiling point 12.5 ° C Molecular weight 96.1 Critical temperature 166 ° C Critical pressure 40 kg / cm ² · ab In the present invention, 1,1-difluoroethyl methyl
Various stabilizers can be used in combination with the ether, if necessary. That is, when a high degree of stability is required under severe use conditions, propylene oxide, 1,
Epoxides such as 2-butylene oxide and glycidol; phosphites such as dimethyl phosphite, diisopropyl phosphite and diphenyl phosphite; thiophosphites such as trilauryl trithiophosphite; trimethyl phosphine sulfide; and triphenoxy phosphine sulfide. Phosphine sulfides, boron compounds such as boric acid, triethyl borate, triphenyl borate, phenylboronic acid and diphenylboronic acid; phenols such as 2,6-di-tert-butylparacresol; aliphatic nitros such as nitromethane and nitroethane Compounds, acrylates such as methyl acrylate, ethyl acrylate, dimethoxymethane, 1,
Ethers such as 4-dioxane and stabilizers such as tert-butanol, pentaerythritol and paraisopropenyl toluene can be added in an amount of about 0.01 to 5% by weight of the working fluid.

Also, 1,1-difluoroethyl methyl
Up to 50% by weight of the ether, other compounds having a boiling point of 1,1-difluoroethyl methyl ether and within ± 50 ° C. can be mixed. Such compounds include HFC-134a, HFC-15
2a, chlorofluorocarbons such as HFC-125, ethers such as pentafluorodimethylether and bis (difluoromethyl) ether, and fluorinated hydrocarbons such as heptafluoropropane, perfluoropropane and perfluorocyclopropane.

[0019]

Since the 1,1-difluoroethyl methyl ether of the present invention contains a hydrogen atom, it has high reactivity with hydroxyl radicals in the atmosphere and is easily decomposed in the troposphere. In addition, since it does not contain chlorine atoms, it does not decompose ozone in the ozone layer, so that it is a compound having a small ozone layer destruction and a small greenhouse effect.

Also, 1,1-difluoroethyl methyl
Ether has excellent thermal stability and its stability is at the same level as conventional fluorocarbons, and its solubility in high molecular compounds is low, so it can be used with minimal material changes in existing refrigeration equipment and the like. .

The 1,1-difluoroethyl methyl ether of the present invention is useful not only as a working fluid for refrigeration equipment but also as a working fluid for heat pumps.

Hereinafter, a production example of the 1,1-difluoroethyl methyl ether of the present invention and an example as a working fluid of the present invention will be described. Of course, the present invention is not limited by the following examples.

[0023]

Example 1 10.0 g (0.178 mol) of potassium hydroxide and methanol (99.9% purity) were placed in a 200 ml stainless steel reactor equipped with a stirrer, a pressure gauge, a thermometer, a gas inlet tube and a gas outlet tube. 64.1g (2.00mo
l) was placed and capped. Then, after removing the air in the reactor, 12.8 g (0. 1 g) of 1,1-difluoroethylene in a cylinder connected to a gas introduction pipe was stirred while stirring.
200 mol) into the reactor, and the reaction temperature was about 50
C. and a reaction pressure of 4 to 5 kg / cm ² G for 20 hours.
Thereafter, the reactor was cooled to around 0 ° C., the lid was opened, and the reaction solution was poured into excess ice water. The separated organic layer was further washed with excess ice water, dried over sodium sulfate, and distilled under atmospheric pressure to give 8.4 g of a colorless and transparent liquid having a boiling point of about 12.5 ° C (GLC analysis purity: 99%). Obtained.

¹ H-NMR, ¹⁹ F-NMR and IR spectra were measured to confirm the structure. As a result, it was found to be 1,1-difluoroethyl methyl ether. Yield 44% (based on charged 1,1-difluoroethylene).

The ¹ H-NMR, ¹⁹ F-NMR and IR spectrum data are shown below. In addition, ¹ H-NMR and ¹⁹ F
-For the measurement of the NMR spectrum, deuterated chloroform was used as a solvent, and tetramethylsilane and trichlorofluoromethane were used as internal standard substances, respectively.

¹ H-NMR (CDCl ₃ ) δ 1.70
_{(T, 3H, J HF =} 13Hz, C H 3 CF 2), 3.
50 (S, 3H, OC H 3). ¹⁹ F-NMR (CDCl ₃ ) δ-72.71 (q, 2
F, J _HF = 13 Hz, CH ₃ CF ₂ ). IR 3030, 2972, 1413, 140
4, 1294, 1231, 1170, 116
2, 1059, 921 cm ^-1 .

[0027]

Example 2 In a 1 hp refrigerating machine using 1,1-difluoroethyl methyl ether as a refrigerant, the condensation temperature [° C.] and the evaporation temperature [° C.] of the refrigerant in the condenser.
Was set to the numerical values shown in Table 1, and the operation was performed with the degree of subcooling of the condenser set to 0 ° C. Evaporation pressure at that time [kg / cm ² ·
ab], condensing pressure [kg / cm ² · ab] and refrigerating capacity [kcal / m ³ ] are shown in [Table 1].

[0028]

Comparative Example 1 A refrigerator was operated in the same manner as in Example 2 except that Freon 114 was used instead of 1,1-difluoroethyl methyl ether. The results are also shown in [Table 1].

[0029]

Example 3 1,1-Difluoroethyl methyl ether was taken in the form of gas in a SUS autoclave (50 ml), and the temperature and internal pressure were measured by raising the temperature from room temperature at a constant rate, and the relationship between the temperature and the pressure was measured. A thermal stability test was performed using the temperature at which the temperature deviates from the ideal gas as the decomposition start temperature. As a result, the decomposition starting temperature was in the range of about 300 to 400 ° C. It was found that it was almost at the same level as the decomposition start temperature of thermally stable Freon 11.

 ──────────────────────────────────────────────────続 き Continuing from the front page (73) Patent holder 000174851 Mitsui-Dupont Fluorochemical Co., Ltd. 1-5-18, Sarugaku-cho, Chiyoda-ku, Tokyo (74) The above four agents Patent Attorney Kyozo Yuasa (6 outside) (72) Inventor Akira Sekiya 1-1-1, Higashi, Tsukuba, Ibaraki Pref., National Institute of Advanced Industrial Science and Technology (72) Inventor, Shiro Yamashita 2-40-17 Hongo, Bunkyo-ku, Tokyo Japan Institute for Global Environmental Technology, Japan New Generation Refrigerant Project Room (72) Inventor Haruaki Ito 2-40-17 Hongo, Bunkyo-ku, Tokyo 2nd Generation Refrigerant Project Room (72) Inventor Yuji Mochizuki 2-Hongo Hongo, Bunkyo-ku, Tokyo No. 40-17 Screening of New Generation Refrigerant Project Room, National Institute of Advanced Industrial Science and Technology Kazuko Nishikawa

Claims (3)

(57) [Claims] 1. A 1,1-difluoroethyl methyl ether. 2. A method for producing 1,1-difluoroethyl methyl ether from a reaction between 1,1-difluoroethylene and methanol. 3. A working fluid comprising 1,1-difluoroethyl methyl ether and one component thereof.