JPH08245470A - Azeotropic composition comprising fluorine-containing ether and 2-propanol - Google Patents

Abstract

PURPOSE: To obtain an azeotropic composition which comprises a specific fluorine-containing ether and propanol and is useful as a substitute of trichloroethane since it has excellent cleaning effect with low toxicity, no anxiety of the ozone layer depletion and reduced greenhouse effect. CONSTITUTION: This composition comprises (A) difluoromethyl 2,2,3,3,-tetra- fluoropropyl ether and (B) 2-propanol. This composition is preferably composed of 62.33 mole % of component A and 37.67 mole % of component B. The component A is obtained, for example, by reaction of chloro-difluoromethane with 2,2,3,3-tetrafluoropropanol in the presence of a base such as KOH. This composition may additionally contain a stabilizer such as nitromethane or the like in an amount of 0.1-5wt.% and a surfactant in an amount of 0.3-5wt.%. This composition boils at 70.43 deg.C under atmospheric pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an azeotropic composition and an azeotrope-like composition, and more specifically, an azeotropic composition and an azeotropic composition used as flux cleaning, degreasing cleaning, draining drying, solvent and the like. Such a composition.

[0002]

2. Description of the Related Art Conventionally, halogenated hydrocarbons have been most well known as cleaning solvents for electronic parts, precision machine parts, resin processed parts, etc. It has characteristics as a hydrogen group. These halogenated hydrocarbons are less toxic,
It shows nonflammability when the number of halogen substitutions is large, is chemically and thermally stable, and has an appropriate solubility to dissolve waxes and fats and oils without eroding the surface of plastics and rubbers. Therefore, it is widely used in various industrial fields. Examples of these halogenated hydrocarbons include chlorine-based hydrocarbons such as trichloroethylene, tetrachloroethylene, and 1,1,1-trichloroethane, and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC 113). CFC-based hydrocarbons are known. Particularly, the latter CFC-based hydrocarbons are used in a wide range of fields because they are less toxic, nonflammable, and chemically and thermally stable.

However, since CFC-containing hydrocarbons containing chlorine and 1,1,1-trichloroethane have chlorine atoms, a serious drawback that the ozone layer in the stratosphere is destroyed is pointed out, and their production and use are stopped. Is decided internationally. Also, regarding trichlorethylene and tetrachloroethylene, the groundwater pollution problem was highlighted, and based on the results of subsequent environmental pollution surveys and the results of the toxicity assessment that chronic toxicity, etc. were found, since 1989, it has been designated as a Class 2 Specified Chemical Substance. Designated. Under such circumstances, the development of substances such as fluorocarbon-containing hydrocarbons containing chlorine and substances substituting for chlorine-based hydrocarbons is being actively conducted.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has excellent properties such as cleanability and low toxicity of CFC-containing hydrocarbons containing chlorine and chlorine-containing hydrocarbons. It is an object of the present invention to provide a novel composition that does not damage the ozone layer and does not worry about ozone layer depletion.

[0005]

DISCLOSURE OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides difluoromethyl 2,2,3
There is provided an azeotropic composition and an azeotrope-like composition comprising 3-tetrafluoropropyl ether and 2-propanol.

The composition of the present invention comprises difluoromethyl
2,2,3,3-tetrafluoropropyl ether
50-80 mol% and 2-propanol 20-50 mol%, preferably difluoromethyl 2,2
3,3-tetrafluoropropyl ether 55-73
Mol% and 2-propanol 27-45 mol%, more preferably difluoromethyl 2,2,3,3
-Tetrafluoropropyl ether 62.33 mol%
And 2-propanol 37.67 mol%. The boiling point of this azeotropic composition is at atmospheric pressure (76
It is 70.43 ° C. at 0 mmHg). It is desired that the cleaning solvent and the draining / drying solvent do not change in composition even if they are recycled by distillation or the like. Compositions of the present invention in the above ranges are those in which the composition of the vapor produced by evaporation or distillation is the same or nearly the same as the composition of the liquid mixture and the composition does not change or changes only negligibly. do not do.

Difluoromethyl 2,2,3,3-tetrafluoropropyl ether is a known substance, for example, by reacting chlorodifluoromethane with 2,2,3,3-tetrafluoropropanol in the presence of potassium hydroxide. Easily obtained.

The composition according to the present invention may further contain various stabilizers when used under severe conditions. As the stabilizer, those which are co-distilled by the distillation operation or those which form an azeotrope-like mixture are desirable. Specific examples of such stabilizers include aliphatic nitro compounds such as nitromethane and nitroethane, aromatic nitro compounds such as nitrobenzene and nitrostyrene, dimethoxymethane, 1,2.
-Dimethoxyethane, 1,4-dioxane, 1,3,5
-Ethers such as trioxane, glycidol, methyl glycidyl ether, allyl glycidyl ether, phenyl glycidyl ether, 1,2-butylene oxide,
Epoxys such as cyclohexene oxide and epichlorohydrin, unsaturated hydrocarbons such as hexene, heptene, pentadiene, cyclopentene and cyclohexene, olefinic alcohols such as allyl alcohol and 1-buten-3-ol, 3-methyl-1-butyne -3-all,
Examples thereof include acetylenic alcohols such as 3-methyl-1-pentyn-3-ol, and acrylic acid esters such as methyl acrylate, ethyl acrylate, butyl acrylate, and vinyl methacrylate. In order to further obtain a synergistic stabilizing effect, phenols, amines and benzotriazoles may be used in combination. These stabilizers may be used alone or in combination of two or more kinds. The amount of the stabilizer used varies depending on the kind of the stabilizer and the like, but it should be such that the azeotrope-like properties are not hindered. The amount used is usually about 0.01 to 10% by weight of the composition of the present invention, and more preferably about 0.1 to 5% by weight.

Further, various surfactants may be added to the composition of the present invention, if necessary, in order to further improve the detergency, the interfacial action and the like. Examples of the surfactant include sorbitan monooleate, sorbitan trioleate and other sorbitan fatty acid esters, polyoxyethylene sorbit tetraoleate and other polyoxyethylene sorbit fatty acid esters, and polyoxyethylene monolaurate and other polyethylene glycol fatty acids. Esters, polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene alkylphenyl ethers such as polyoxyethylene nonylphenyl ether, polyoxyethylene alkylamine fatty acid amides such as polyoxyethylene oleic acid amide The nonionic surface active agent may be used alone or in combination of two or more kinds. For the purpose of synergistically improving the detergency and the surface action, a cationic surfactant or an anionic surfactant may be used in combination with these nonionic surfactants. Although the amount of the surfactant used varies depending on the type of the surfactant, it is usually 0.1% of the composition of the present invention as long as it does not hinder the azeotropic property.
Is about 20 to 20% by weight, and more preferably about 0.3 to 5% by weight.

The composition of the present invention can be widely used for well-known cleaning and drying applications, but can be particularly used as a flux cleaning agent, a cleaning solvent, a degreasing cleaning agent, and a draining desiccant. It is extremely useful as a substitute for 1-trichloroethane. Specific applications include flux, grease, oil, wax, ink and other removers, electronic components (printed circuit boards, liquid crystal displays, magnetic recording components, semiconductor materials, etc.), electrical components, precision machine components,
Examples include cleaning agents for resin-processed parts, optical lenses, clothing, draining desiccants, and the like. As the cleaning method, a conventionally used method such as dipping, spraying, boiling cleaning, ultrasonic cleaning, steam cleaning or a combination thereof can be adopted.

Further, the composition of the present invention can be used in various applications such as a solvent for paints, an extracting agent, a heat medium and a foaming agent, as in the case of conventional CFCs.

[0012]

EXAMPLES Examples will be shown below to further clarify the features of the present invention. Of course, the invention is not limited by these examples.

[0013]

Reference Example 1 Synthesis of difluoromethyl 2,2,3,3-tetrafluoropropyl ether Potassium hydroxide was added to a 200 ml stainless reactor equipped with a stirrer, a pressure gauge, a thermometer, a gas introduction pipe and a gas discharge pipe. 0.0 g (0.713 mol) and 2,2,3,3
-Tetrafluoropropanol 165.2 g (1.2
(5 mol) was added and the lid was closed. Then, after removing the air in the reactor, chlorodifluoromethane contained in a cylinder connected to a gas introduction pipe was injected into the reactor with stirring (up to a pressure of 7.0 kg / cm ² G). Then, the temperature in the reactor was gradually raised by external heating while stirring, and was maintained at about 90 to 100 ° C. As the reaction progresses,
The pressure in the reactor dropped. Therefore, chlorodifluoromethane was added to the reactor at a pressure of 7.0 kg / cm every predetermined time.
^The operation of injecting was repeated until ² G was reached. Then, when the pressure drop hardly occurred (15 hours), the stirring was stopped and the reactor was cooled to around 0 ° C. The total amount of chlorodifluoromethane charged was 27.4 g (0.317 m
ol). After the pressure inside the reactor was returned to atmospheric pressure, the lid of the reactor was opened and the reaction solution was poured into excess ice water. The separated organic layer was further washed with an excess of ice water, dried over anhydrous sodium sulfate, and then distilled under atmospheric pressure to obtain difluoromethyl 2,2,3,3-tetrafluoropropyl ether having a purity of 99% or more ( Boiling point about 75 ° C) 3
2.2 g was obtained.

[0014]

[Reference Example 2] Measurement of gas-liquid equilibrium and measurement of azeotropic point It was measured using a gas wave equilibrium measuring apparatus. A mixed sample of difluoromethyl 2,2,3,3-tetrafluoropropyl ether and 2-propanol having a constant composition was placed in a sample container and heated. Then, heating was adjusted so that the dropping rate of the vapor-phase condensate was appropriate, and stable boiling was maintained for 40 minutes or more. After making sure that the pressure and boiling point were stable, they were measured. Further, the liquid phase and the gas phase condensate were sampled, and the composition of the sampling liquid was analyzed by gas chromatography. The measurement results are shown in Table 1 and FIG.

In FIG. 1, the vertical axis represents temperature (° C.) and the horizontal axis represents the concentration (molar fraction) of difluoromethyl 2,2,3,3-tetrafluoropropyl ether.

From this result, difluoromethyl 2,
2,3,3-tetrafluoropropyl ether 50-
Compositions of the present invention in the range of 85 mol% and 2-propanol 20-50 mol% have the composition of their vapors produced by evaporation or distillation the same or nearly the same as that of the liquid mixture, Are azeotropic and azeotrope-like compositions which do not change or change only negligibly. Where difluoromethyl 2,2
3,3-tetrafluoropropyl ether 62.3
The composition consisting of 3 mol% and 2-propanol 37.67 mol% is an azeotropic composition, the boiling point of which is 70.43 ° C. at atmospheric pressure (760 mmHg).

[0017]

[Table 1]

[0018]

Example 1 A flux cleaning test was conducted using a composition consisting of 62.33 mol% of difluoromethyl 2,2,3,3-tetrafluoropropyl ether and 37.67 mol% of 2-propanol.

Test piece (SUS-316; 50 mm
X 10 mm x 1 mm) was dipped in flux [GX-8S manufactured by Asahi Chemical Research Institute Co., Ltd.], and then taken out to give 20
It heat-processed at 0 degreeC for 1 minute. The test piece was ultrasonically cleaned in the above composition for 1 minute and then dried with warm air. When the state of flux removal was observed with the naked eye, it was found to be well removed.

[0020]

Example 2 The example of Example 1 was repeated except that the composition of Example 1 was replaced by 80 mol% of difluoromethyl 2,2,3,3-tetrafluoropropyl ether and 20 mol% of 2-propanol. When the same test as in No. 1 was conducted, it was confirmed that the flux could be removed well.

[0021]

Example 3 Example 3 except that instead of the composition of Example 1, a composition consisting of 50 mol% of difluoromethyl 2,2,3,3-tetrafluoropropyl ether and 50 mol% of 2-propanol is used. When the same test as in No. 1 was conducted, it was confirmed that the flux could be removed well.

[0022]

Example 4 A removal test of adhering water was conducted using a composition consisting of 62.33 mol% of difluoromethyl 2,2,3,3-tetrafluoropropyl ether and 37.67 mol% of 2-propanol.

A glass plate (30 mm) that has been thoroughly degreased and washed in advance.
(× 20 mm × 1 mm) was dipped in pure water, and then dipped in the above mixed solvent composition for 30 seconds. The glass plate taken out was allowed to stand at room temperature for 1 minute to evaporate the remaining composition, then immersed in anhydrous methanol, and the increase in water content of the methanol was measured by a Karl Fischer moisture meter. On the other hand, when the removal state of adhering water was examined by comparison with the amount of increase in water content of methanol when only immersed in pure water and not immersed in the above mixed solvent composition, in the above mixed solvent composition It was found that the adhered water could be almost completely removed when immersed in.

[0024]

EXAMPLE 5 Example 5 is repeated except that the composition of Example 4 is replaced by a composition consisting of 80 mol% of difluoromethyl 2,2,3,3-tetrafluoropropyl ether and 20 mol% of 2-propanol. When the test was conducted in the same manner as in No. 4, it was found that the adhered water could be removed almost completely.

[0025]

Since the composition of the present invention contains no chlorine atom, there is no fear of ozone layer depletion. Further, since the composition of the present invention contains hydrogen atoms, it has high reactivity with hydroxyl radicals in the atmosphere and is easily decomposed in the troposphere, so that the greenhouse effect is small.

[Brief description of drawings]

FIG. 1 is a vapor-liquid equilibrium curve of a difluoromethyl 2,2,3,3-tetrafluoropropyl ether-2-propanol system.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (71) Applicant 000002004 1-13-9 Shibadaimon, Minato-ku, Tokyo (71) Applicant 000002200 Central Glass Co., Ltd. 5253 Oki, Ube, Ube-shi, Yamaguchi (71) Applicant 000000044 Asahi Glass Co., Ltd. 2-1-2 Marunouchi, Chiyoda-ku, Tokyo (71) Applicant 000174851 Mitsui DuPont Fluorochemical Co., Ltd. 1-5-18 Sarugakucho, Chiyoda-ku, Tokyo (71) Applicant 000003300 Tosoh Corporation Company 4560, Kaisei-cho, Shinnanyo-shi, Yamaguchi (74) Attorney for the above 6 persons Attorney Kyozo Yuasa (6 outside) (72) Inventor Akira Sekiya Ichiban Ichiban Ichiban Ichigo Industrial Technology Institute Material Engineering Industrial Technology (72) Inventor Shiro Yamashita 2-40-17 Hongo, Bunkyo-ku, Tokyo Hongo Wakai Building 6F Foundation Law New Generation Refrigerant Project Room, Japan Agency for Global Environmental Science and Technology (72) Inventor Haruaki Ito 2-40-17 Hongo Hongo, Bunkyo-ku, Tokyo Hongo Wakai Building 6F, New Generation Refrigerant Project Office (72) Inventor Yoshihiko Goto 2-40-17 Hongo, Bunkyo-ku, Tokyo Hongo-Wakai Building, 6th floor, New Generation Refrigerant Project Office, Research Institute for Global Environmental Technology (72) Inventor, Atsushi Suga Hongo, Bunkyo-ku, Tokyo 2-40-17 Hongo-Wakai Building 6th floor Foundation for Global Environment and Industrial Technology, New Generation Refrigerant Project Room (72) Inventor Yuji Mochizuki 2-40-17 Hongo, Bunkyo-ku, Tokyo Hongo Wakai Building 6th floor New Generation Refrigerant Project Room, Japan Agency for Global Environmental Science and Technology (72) Inventor Noritaka Nagasaki 2-40-17 Hongo Hongo, Bunkyo-ku, Tokyo Hongo Wakai Building 6F, New Generation Institute for Global Environmental Technology Refrigerant professional Ject room

Claims (4)

[Claims] 1. An azeotrope-like composition comprising difluoromethyl 2,2,3,3-tetrafluoropropyl ether and 2-propanol. 2. An azeotrope-like composition according to claim 1, which comprises 50 to 80 mol% of difluoromethyl 2,2,3,3-tetrafluoropropyl ether and 20 to 50 mol% of 2-propanol. . 3. A cleaning solvent comprising the composition according to claim 1. 4. A solvent for draining and drying, which comprises the composition according to claim 1.