JPH01141996A - Fluorinated hydrocarbon-based azeotropic mixture - Google Patents

Abstract

PURPOSE:To provide the title mixture which can be used as a fluorocarbon (flon) substitute, by mixing a member selected from n-pentane, 2-methylbutane and 2,2-dimethylbutane with 1,1-dichloro-1-fluoroethane. CONSTITUTION:The title mixture is obtd. by mixing a member selected from n-pentane, 2-methylbutane and 2,2-dimethylbutane with 1,1-dichloro-1-fluoroethane. The mixture provides an azeotropic compsn., and suffer from less compsn. change even when recycled. It can be used for various purposes, e.g., as a heating medium, a foaming agent or the like in place of the conventional fluorocarbon. In particular, when it is used as a solvent, its detergency is higher than that of the conventional fluorocarbon, and hence it is suited for use as a cleaning solvent for replacing the conventional fluorocarbon. Depending on usages, further, a hydrocarbon, an alcohol, etc., may be added to the azeotropic mixture.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a novel fluorinated hydrocarbon azeotrope-like mixture that can be used as a CFC substitute and has excellent properties as a solvent and the like.

[Prior art] Fluorinated hydrocarbon compounds (hereinafter simply referred to as fluorocarbons) are mostly non-toxic, nonflammable, and chemically stable.
Since various types of fluorocarbons with different standard boiling points are available, they are used as solvents, blowing agents, propellants, refrigerants, etc. by taking advantage of these characteristics. For example, 1,1,2-trichloro-1,2,2-
Trifluoroethane (RI+3) is used as a blowing agent, trichloromonofluoromethane (R11) is used as a blowing agent, and dichlorodifluoromethane (RI21) is used as a propellant or refrigerant.

[Problems to be solved by the invention] Chemically particularly stable R11, RI2. RII3 has a long life in the troposphere and diffuses into the stratosphere, where it is decomposed by sunlight and generates chlorine radicals that cause a chain reaction with ozone and destroy the ozone layer. There is a movement to regulate the use of 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 novel fluorocarbon mixture that can be used as a fluorocarbon substitute while satisfying the excellent properties of conventional fluorocarbons.

[Means for Solving the Problems] The second invention provides a combination of one kind of hydrocarbons and 1,1-dichloro-1-
The present invention relates to a fluorinated hydrocarbon and an azeotrope-like mixture of fluoroethane (RI41b) and fluoroethane (RI41b).

RI
This is an extremely useful alternative to +3.

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

The mixing ratio of each hydrocarbon of the present invention to R141b is n
- Pentane is 15-35% by weight, 2-methylbutane is 3% by weight.
8 to 58% by weight, 2,2-dimethylbutane is 1 to 21% by weight, preferably n-pentane is 20 to 30% by weight, 2-methylbutane is 43 to 53% by weight, and 2,2-dimethylbutane is 1 to 21% by weight. 5 to 15% by weight, more preferably 25.5% by weight of n-pentane, 48.5% by weight of 2-methylbutane, and 10% by weight of 2.2-dimethylbutane.
It is.

Other components may be further added to the mixture of the present invention depending on the intended use. For example, when used as a solvent, hydrocarbons such as hexane, isohexane, heptane, and isohebutane, nitroalkanes such as nitromethane, nitroethane, and nitropropane, diethylamine, triethylamine, isopropylamine, butylamine, isobutylamine, etc. Amines, alcohols such as methanol, ethanol, n-propyl alcohol, i-propyl alcohol, n-butanol, 1-butanol, ethers such as methyl cellosolve, tetrahydrofuran, 1,4-dioxane, acetone, methyl ethyl ketone, methyl One or more selected from ketones such as butyl ketone, esters such as ethyl acetate, propyl acetate, butyl acetate, etc. can be added and mixed. .

The mixture of the invention consisting of RI41b and hydrocarbons is
Like conventional fluorocarbons, it can be used for various purposes such as a heat medium and a blowing agent, and is particularly suitable when used as a solvent because it has higher dissolving power than conventional RI+3. Specific uses of solvents include removal agents for flux, grease, oil, wax, ink, etc., solvents for paints, extractants, glass, ceramics, plastics, rubber, various metal products, especially ICs.
Examples include cleaning agents and draining agents for parts, electrical equipment, precision machinery, optical lenses, etc. As a cleaning method, hand wiping, dipping, spraying, shaking, ultrasonic cleaning, steam cleaning, etc. may be used.

[Example] Example 1 1.000 g of each mixture having the composition shown in Table 1 was placed in a distillation flask, and distilled under atmospheric pressure using a rectification column with 20 theoretical plates. A fraction was obtained. The distillation temperatures at this time were as shown in Table 2. or,
'As a result of measuring this fraction with a gas chromatograph, the second
It was as shown in the table.

Table 1 Table 2 Example 2 A flux cleaning test was conducted using the mixture of the present invention. Flux (Tamler AL-4) on the entire printed circuit board
．． (manufactured by Tamura Seisakusho) was applied, baked for 2 minutes in an electric furnace at 200°C, and then immersed in the mixture of the present invention for 1 minute. A similar test was conducted for R113 as an example of a shark. Table 3 shows the composition of the mixture of the present invention and the degree of flux removal.

Table 3: 0: completely removed, O: trace amount remaining △; small amount remaining, It can be used as a substitute for CFCs while satisfying the above characteristics, and since it has an azeotropic point,
It has the advantage that there is no change in composition during recycling, it can be used in the same way as conventional single fluorocarbons, and it does not require major changes to conventional technology. In addition, R113, which is often used as a solvent,
Old 1 because it has better ability to dissolve and remove flux and oil, etc.
It is suitable as a cleaning solvent in place of No. 3.

Claims (1)

[Claims] One selected from 1, n-pentane, 2-methylbutane, or 2,2-dimethylbutane and 1,1-dichloro-1
- a fluorinated hydrocarbon azeotrope-like mixture consisting of fluoroethane.