JPH0338534A - Fluorohydrocarbon azeotropic and pseudoazeotropic compositions - Google Patents

Abstract

PURPOSE:To provide the subject composition satisfied with the excellent characteristics of the conventional Freon, capable of being used as a Freon substitute and having excellent characteristics as a solvent, etc., by comprising 1,1-dichloro-1-fluoroethane and methylene chloride. CONSTITUTION:A fluorohydrocarbon azeotropic composition comprises 87.5wt.% of (A) 1,1-dichloro-1-fluoroethane and 12.5wt.% of (B) methylene chloride, and a pseudoazeotropic composition comprises 75-94wt.% of the component A and 6-25wt.% of the component B. The composition exists as an azeotropic composition, is especially highly useful as a cleansing agent having a high cleansing power and with a reduced change of the composition even when recycled. The composition can be used in the same manner as the conventional single Freon and does not require the large change of the conventional techniques.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a novel fluorinated hydrocarbon azeotropic and near-azeotropic composition that can be used as a CFC substitute and has excellent properties as a solvent. be.

[Conventional technology 1 Fluorinated hydrocarbon compounds (hereinafter simply referred to as fluorocarbons) are
Many of them are less toxic and chemically stable, and various types of fluorocarbons with different standard boiling points are available, so these properties can be utilized to use them as solvents, blowing agents, propellants, refrigerants, etc. 2.2-Trifluoroethane (R113) is used as a blowing agent, trichloromonofluoromethane (R11) is used as a blowing agent, and dichlorodifluoromethane (R12) is used as a propellant or refrigerant.

[Problem to be solved by the invention] R11, R12, and R113, which are particularly stable chemically, have a long life in the troposphere and diffuse into the stratosphere, where they are decomposed by sunlight and generate chlorine radicals, which are converted into ozone. Conventional regulations on the use of these fluorocarbons have been implemented because they are believed to cause a chain reaction and destroy the ozone layer. For this reason, the search for alternative fluorocarbons that are less likely to deplete the ozone layer is being actively conducted in place of these conventional fluorocarbons.

An object of the present invention is to provide a new fluorocarbon composition that can be used as a fluorocarbon substitute while reducing the amount of conventional fluorocarbons used and satisfying the excellent properties of the fluorocarbons. .

[Means for Solving the Problems] The present invention provides 1,1-dichloro-1-fluoroethane (R
141b (boiling point: 32°C), and methylene chloride (boiling point: 39.8°C). The composition of the present invention has an azeotropic composition and has higher cleaning power than conventional R113 alone as a cleaning solvent, so it is extremely useful as a substitute for R113.

Furthermore, there is little change in composition even after recycling, and
It has the advantage that it can be used in the same way as conventional single fluorocarbons and does not require major changes to the conventional technology.

The mixing ratio of the composition of the present invention is a pseudoazeotropic composition in which 8141b is 75 to 94% by weight and methylene chloride is 6 to 25% by weight, preferably R141b is 87.5% by weight and methylene chloride is 12.5% by weight. The azeotropic composition is in weight percent.

Other components may be further added to the composition of the present invention depending on the intended use. For example, pentane in its application as a solvent.

Isopentane, hexane, isohexane, neohexane, heptane, isohebutane, 2,3-dimethylbutane,
Hydrocarbons such as cyclopentane, nitroalkanes such as nitromethane, nitroethane, nitropropane, amines such as diethylamine, triethylamine, isopropylamine, butylamine, isobutylamine, methanol, ethanol, n-propyl alcohol, i-propyl alcohol, Alcohols such as n-butyl alcohol, i-butyl alcohol, S-butyl alcohol, t-butyl alcohol, ethers such as methyl cellosolve, tetrahydrofuran, l,4-dioxane, acetone,
Ketones such as methyl ethyl ketone and methyl butyl ketone, esters such as ethyl acetate, propyl acetate, butyl acetate, trans-1,2-dichloroethylene, cis
-Add appropriate halogenated hydrocarbons such as 1,2-dichloroethylene and 2-bromopropane, and other fluorocarbons other than those of the present invention such as 1,1.2-trichloro-2,2-difluoroethane (R122). be able to.

The fluorinated hydrocarbon azeotropic and near-azeotropic compositions of the present invention can be used in various applications such as heat carriers and blowing agents, similar to conventional fluorocarbons, and particularly when used as a solvent, have a higher solubility than conventional R113. It is suitable because it has power.

A specific use of the solvent is flux.

Remover for grease, oil, wax, ink, etc.

Paint solvents, extractants, glass, and ceramics.

Various products made of plastic, rubber, and metal, especially IC parts,
Examples include cleaning agents and draining agents for electrical equipment, precision machinery, optical lenses, etc.

As a cleaning method, hand wiping, dipping, spray shaking, ultrasonic cleaning, steam cleaning, etc. may be employed.

[Example] Examples of the present invention are shown below.

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

(Composition) (% by weight) R141b
90 methylene chloride
As a result, at a distillation temperature of 27.5°C, 200
A fraction of g was obtained. As a result of measuring this product with a gas chromatograph, it had the following composition.

(Composition) (% by weight) R141b
87.5 methylene chloride
12.5 Example 2 A flux cleaning test was conducted using the composition of the present invention. Flux (Tamura AL-4.
Tamura Manufacturing Co., Ltd.) was applied, baked for 2 minutes in an electric furnace at 200°C, and then immersed in the composition of the present invention for 5 minutes. A similar test was also conducted for R113 as a comparative example.

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

Table 1 0: Can be removed well ○: Good removal Δ: Trace amount remaining
×: Significant residual Example 3 A machine oil cleaning test was conducted using the composition of the present invention.

5O5-304 test piece (25ml II x 30
mm x 2 mm thick) with machine oil (CQ-30, Nippon Oil)
After that, the sample was immersed in the composition of the present invention for 5 minutes. A similar test was also conducted for R113 as a comparative example.

The mixing ratio of the composition of the present invention and the degree of removal of machine oil are shown in Table 2.

Table 2 0: Can be removed well ○: Good △: Trace amount remains
×: Significant residual [Effect of the invention] The fluorinated hydrocarbon azeotropic and near-azeotropic compositions of the present invention can be used as an alternative fluorocarbon while satisfying the excellent properties of conventional fluorocarbons. , it can be used in the same way as conventional fluorocarbons, so it has the advantage of not requiring major changes to the conventional technology. In addition, it has better ability to dissolve and remove fluxes and oils than R113, which is often used as a solvent, so it is most suitable as a cleaning solvent in place of R113.

Claims (4)

[Claims] (1) A fluorinated hydrocarbon azeotropic composition consisting of 1,1-dichloro-1-fluoroethane and methylene chloride. (2) 1,1-dichloro-1-fluoroethane 87.5
% by weight, and 12.5% by weight of methylene chloride. (3) A fluorinated hydrocarbon-based pseudoazeotropic composition consisting of 1,1-dichloro-1-fluoroethane and methylene chloride. (4) 1,1-dichloro-1-fluoroethane 75-9
4% by weight of methylene chloride and 6-25% by weight of methylene chloride.