JP2738034B2 - Fluorinated hydrocarbon azeotropic and pseudo-azeotropic compositions - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a novel fluorinated hydrocarbon-based azeotropic and pseudo-azeotropic composition which can be used as a substitute for chlorofluorocarbon and has excellent properties as a solvent and the like. is there.

[Prior art] Fluorinated hydrocarbon compounds (hereinafter simply referred to as chlorofluorocarbon)
Since many types of fluorocarbons with low toxicity and chemical stability are available, and various types of fluorocarbons having different standard boiling points are available, these characteristics are utilized to make 1,1,2-trichloro- as a solvent, a foaming agent, a propellant or a refrigerant. 1,2,2-Trifluoroethane (R113) is used as a blowing agent, trichloromonofluoroethane (R11) is used, and dichlorodifluoromethane (R12) is used as a propellant and a refrigerant.

[Problems to be Solved by the Invention] R11, R12, and R113, which are chemically particularly stable, have a long life in the troposphere and diffuse to reach the stratosphere, where chlorine radicals generated by decomposition by sunlight are converted into ozone. It causes a chain reaction and destroys the ozone layer, and the use of these conventional fluorocarbons has been regulated. Therefore, instead of these conventional fluorocarbons, the search for alternative fluorocarbons that are less likely to destroy the ozone layer is being actively conducted.

An object of the present invention is to provide a novel CFC composition which can be used as an alternative CFC while reducing the amount of conventional CFC used and satisfying the excellent characteristics of the CFC. .

[Means for Solving the Problems] The present invention relates to 1,1-dichloro-1-fluoroethane (R14
1b, boiling point 32 ° C) and methylene chloride (boiling point 39.8
C.) in the form of a fluorinated hydrocarbon-based azeotropic and pseudo-azeotropic composition. Since the composition of the present invention has an azeotropic composition and has a higher detergency than the conventional R113 alone as a cleaning solvent, it is extremely useful as a substitute for R113.

Further, the azeotropic composition of the present invention has no change in composition even when recycled, and the pseudo-azeotropic composition of the present invention has little change in composition even when recycled. The azeotropic composition can be used in the same way as the conventional single CFC,
There are advantages such as not requiring a significant change in the prior art.

The mixing ratio of the composition of the present invention is a pseudo-azeotropic composition in which R141b is 75 to 94% by weight and methylene chloride is 6 to 25% by weight, or a mixture in which R141b is 87.5% by weight and methylene chloride is 12.5% by weight. It is a boiling composition.

Other components can be further added to and mixed with the composition of the present invention depending on the use. For example, in the use as a solvent, pentane, isopentane, hexane, isohexane, neohexane, heptane, isoheptane,
Hydrocarbons such as 2,3-dimethylbutane and cyclopentane; nitroalkanes such as nitromethane, nitroethane and nitropropane; amines such as diethylamine, triethylamine, isopropylamine, butylamine and isobutylamine; methanol, ethanol and n-propyl Alcohol, i-propyl alcohol, n-butyl alcohol, i-butyl alcohol, s-butyl alcohol, t-
Alcohols such as butyl alcohol; ethers such as methyl cellosolve, tetrahydrofuran and 1,4-dioxane; ketones such as acetone, methyl ethyl ketone and methyl butyl ketone; esters such as ethyl acetate, propyl acetate and butyl acetate; , 2-dichloroethylene, cis
Halogenated hydrocarbons such as -1,2-dichloroethylene, 2-bromopropane, and others, 1,1,2-trichloro-2,2-
Freons other than R141b such as difluoroethane (R122) can be appropriately added.

The fluorinated hydrocarbon-based azeotropic and pseudo-azeotropic composition of the present invention,
Like conventional CFCs, it can be used for various applications such as a heating medium and a foaming agent, and is particularly suitable when used as a solvent because it has higher dissolving power than conventional R113.

Specific applications of solvents include fluxes, greases, oils, waxes, removers for inks, paint solvents, extractants, glass, ceramics, plastics, rubber, various metallic articles, especially IC parts, electrical equipment, Examples of the cleaning agent include a precision machine, a cleaning agent for an optical lens, and a draining agent.
As a cleaning method, hand wiping, dipping, spraying, rocking, ultrasonic cleaning, steam cleaning, or the like may be employed.

[Example] An example of the present invention will be described below.

Example 1 1000 g of a solvent mixture having the following composition was placed in a distillation flask, and distillation was performed under atmospheric pressure using a rectification column having 20 theoretical plates.

(Composition) (% by weight) R141b 90 Methylene chloride 10 As a result, 200 g of a fraction was obtained at a distillation temperature of 27.5 ° C. This was measured by gas chromatography to find that it had the following composition.

(Composition) (% by weight) R141b 87.5 Methylene chloride 12.5 Example 2 A cleaning test of a flux was performed using the composition of the present invention. A flux (Tamura AL-4, manufactured by Tamura Seisakusho) was applied to the entire surface of the printed board, baked in an electric furnace at 200 ° C. for 2 minutes, and immersed in the composition of the present invention for 5 minutes. R1 as a comparative example
A similar test was performed for 13 as well.

Table 1 shows the mixing ratio of the composition of the present invention and the degree of flux removal.

Example 3 A cleaning test of a machine oil was performed using the composition of the present invention.

A test piece (25 mm × 30 mm × 2 mm thick) of SUS-304 was immersed in machine oil (CQ-30, manufactured by Nippon Oil Co., Ltd.), and then immersed in the composition of the present invention for 5 minutes. The same test was performed for R113 as a comparative example.

Table 2 shows the mixing ratio of the composition of the present invention and the degree of removal of the machine oil.

[Effect of the Invention] The fluorinated hydrocarbon-based azeotropic and pseudo-azeotropic composition of the present invention comprises:
While satisfying the excellent characteristics of conventional CFCs,
Since it can be used as a substitute for chlorofluorocarbon and can be used in the same manner as conventional chlorofluorocarbon, there is an advantage that a significant change of the conventional technology is not required. In addition, R113 is more suitable as a cleaning solvent instead of R113 because it has better dissolving and removing properties for flux and oil than R113, which is often used as a solvent.

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Claims (4)

(57) [Claims] 1. A fluorinated hydrocarbon azeotropic composition comprising 1,1-dichloro-1-fluoroethane and methylene chloride. (2) 1,1-dichloro-1-fluoroethane 87.5
The composition according to claim 1, comprising 1% by weight and 12.5% by weight of methylene chloride. 3. A fluorinated hydrocarbon-based pseudo-azeotropic composition comprising 1,1-dichloro-1-fluoroethane and methylene chloride. 4. A 1,1-dichloro-1-fluoroethane 75 to 9
4. A composition according to claim 3, comprising 4% by weight and 6 to 25% by weight of methylene chloride.