JPS5929625A - Fluorohydrocarbon type composition - Google Patents

Abstract

PURPOSE:The titled composition, prepared by incorporating a specific boric acid ester with a halogenated hydrocarbon type mixture containing a fluorohydrocarbon useful as propellants for aerosols, etc, having improved stability of the above- mentioned mixture and anticorrosion effect of metal, etc. CONSTITUTION:A fluorohydrocarbon type mixture prepared by incorporating a compound of formula I [R1 is formula II (R3 and R4 are H, CH3 or C2H5); R2 is 1-4C alkyl; l, m and n are integers representing the average repeating numbers of R1 and 1-10] as a stabilizer with a mixture containing a halogenated hydrocarbon (FHC) containing fluorine and other halogen to improve the stability thereof. The FHC is used as one component in various industrial detergents or refrigerants in absorption type refrigerators or working fluids in turbines in combination with an absorbent in addition to the above-mentioned use. The above-mentioned stabilizer improves the stability of the FHC in all the uses thereof and exhibits sufficient effects on the corrosion of metallic materials, e.g. iron, aluminum, copper or zinc, etc.

Description

[Detailed description of the invention] The present invention relates to a composition that improves the stability of a hydrocarbon mixture.

As is well known, lower halogenated hydrocarbons (hereinafter abbreviated as FHC) containing fluorine and other halogens include:
As a globelant for aerosols, as well as for electrical and electronic industries,
It is widely used as a component of cleaning agents in the resin industry and precision machinery industry.

Furthermore, these FHOs have recently been used in combination with absorbents as refrigerants for absorption refrigerators, or as working media for turbines that utilize cold sources. Factors contributing to FHO's use in these applications include its low toxicity, non-flammability, solubility, heat transfer properties, and excellent absorption properties; however, on the other hand, FIHO alone is not suitable for the above-mentioned applications. However, it is easy to decompose even under normal usage conditions, and therefore there are problems with stability. This decomposition is mainly caused by dehydrohalogenation, and it is known that υ decomposition is further promoted by contact between FHC and hydroxyl group-containing compounds, temperature rise, contact with metals or general compounds, etc. At the same time, corrosion of the metals constituting the containers and the like was also a problem. To describe these more specifically, in aerosol products, FHO is usually used in combination with an alcohol solvent, but as soon as it decomposes, the container corrodes and the product quality deteriorates. As mentioned above, industrial cleaning agents are usually used in mixtures with alcohol, ketones, or chlorinated hydrocarbons, but the same decomposition and accompanying corrosion occur, resulting in deterioration of product quality and damage. This may also lead to contamination of the cleaning items. When used as a refrigerant in absorption refrigerators or as a turbine working medium, it is used in combination with absorbents such as polyethylene glycol dimethyl ether, dimethyl formamide, and tetrahydrofur-7lylalkyl ether, and is generally used at an operating temperature of 100 to 200°C. In some cases, there is a greater possibility of decomposition than when used as an aerosol or cleaning agent, and at the same time corrosion of the mounting metal may occur, which may significantly reduce the functionality of the device, which is extremely serious.

For the above reasons, when FHC is used for the above applications, a compound that suppresses the above-mentioned decomposition, a so-called stabilizer, is added to FHO, and various compounds have been proposed as this stabilizer.

Prior examples of stabilizers include examples in which an aromatic nitro compound is used as one component and various unsaturated compounds or heterocyclic compounds are used in combination (Japanese Patent Publication No. 13697/1982), and acid esters using an amine compound. (Japanese Unexamined Patent Publication No. 55-48277), an example using dialkylpentaerythritol diphosphite (Japanese Unexamined Patent Publication No. 55-48277),
700'82). Although these compounds generally serve the purpose of being stabilizers,
However, it is not necessarily sufficient in terms of long-term stabilizing effect, decomposition suppressing effect at high temperatures, metal corrosion preventing effect, etc., and it does not have a stabilizing effect for all uses.

Taking the above points into consideration, the present inventors have determined that the FH
As a result of searching for a stabilizer that improves the stability of O and is also effective against corrosion of metal materials such as iron, aluminum, copper, and zinc, we have developed a specific boron compound as FHO.
The present inventors have discovered that the above object can be achieved by adding it as a stabilizer to a mixture containing . That is, the present invention is a fluorinated hydrocarbon composition containing a boric acid ester represented by the following general formula (1).

To explain the boric acid ester represented by the above general formula [I] in more detail, R1 is preferably an oxyethylene group, an oxypropylene group, or an oxybutylene group;
Three R1's in one compound may be the same, one or two different, or different from each other.

It is essential for these oxyalkylene groups to have three bonds to the boron atom as a component of the composition of the present invention, but as described above,

It is sufficient that the positive number indicated by nl has an average of 1 or more and 10 or less. The alkyl group represented by R2 specifically includes methyl, ethyl, normal propyl, inglovil, normal phthyl, isobutyl, 8θC-butyl, and tθrt-butyl, but as mentioned above, per compound, the same or There may be two or more differences.

These boric acid esters can be produced by conventionally known methods, for example, R2-(R1)-OH-[ll] alkylene glycol monoalkyl represented by the general formula [11] Through the esterification reaction between ether and boric acid,
Alternatively, it can be produced by a transesterification reaction with a boric acid ester. Glycol monoalkyl ether represented by the general formula [■], monoethylene glycol monoalkyl ether, polyethylene glycol monoalkyl ether, monopropylene glycol monoalkyl ether, polypropylene glycol monoalkyl ether, or various alkyl-substituted ethylene glycols ( Examples include monoalkyl ether (mono- or poly). It goes without saying that the alkyl group here represents a methyl, ethyl, propyl, inpropyl, butyl, isobutyl, θec-butyl, or tart-butyl group, as described above. Alternatively, the term poly- means that the number of repetitions of various oxyalkylene groups is greater than 1 and is a positive number of 10 or less, as described above. These glycol ethers are reacted as one type or a mixture of two or more types with boric acids to form a compound represented by the general formula [1), which is used as a stabilizer that is a component of the composition of the present invention. .

The FHO constituting the composition of the present invention is a halogenated hydrocarbon in which one or more atoms of fluorine, chlorine, and/or bromine are substituted, such as dichloromonofluoromethane, monochlorodifluoromethane, monochloromonofluoromethane, trichloromonofluoromethane, and trichloromonofluoromethane. Halogen-substituted methane such as methane, dichlorodifluoromethane, monochlorotrifluoromethane, monopromotrifluoromethane,
Examples include halogen-substituted ethane such as trichlorotrifluoroethanetetrachlorodifluoroethane, dichlorotetrafluoroethane, monochlorotetrafluoroethane, monochloropentafluoroethane, monochlorotrifluoroethane, and monobromomonochlorodifluoroethane.

Since the composition of the present invention is essentially used for the purposes described above, it may further contain other components.

Other ingredients vary depending on the application, and when used as a globalant for aerosol products, they are often lower aliphatic alcohols such as methanol, ethanol, and propatools, and when used as various industrial cleaning agents, lower alcohols are used. , ketones, or other halogenated hydrocarbons, and in the above-mentioned working media and refrigerants for absorption refrigerators, they are often used in combination with the above-mentioned absorbents. The content of other components is often 5 to 80%.

The content of the boron compound represented by the above-mentioned general formula [1] constituting the composition of the present invention is preferably o,ooi% by weight or more and 10% by weight or less, based on the composition containing FHO alone or the sixth component. , a range of 0.01 to 50% by weight is suitable, and particularly an effect is exhibited in a range of 0.601 to 10% by weight.

If a composition having the composition described above is used for the above-mentioned purposes, in addition to preventing the decomposition of FHC itself in the conventional method, (a) metals such as iron, aluminum, copper, zinc, etc. that come into contact with this composition can be used. Corrosion of the material is significantly suppressed, and (o) decomposition of FHO itself is significantly prevented over a wider temperature range, specifically from -50 to 250°C, especially from 100 to 200°C. Excellent effects appear at such high temperatures.

As described above, the composition of the present invention contains FHOs, general formula [I]
It is often composed of a specific boron compound stabilizer shown in , and in some cases a sixth component, but depending on the use or necessity, it may contain about 10 to 60% of other components by weight. Good too.

Examples and comparative examples will be described below to explain the present invention in more detail, but the present invention is not limited thereto. In addition, hereinafter, parts described as parts refer to parts by weight unless otherwise specified.

Examples 1 and 2 A test piece made of steel, steel, and aluminum measuring 0.8 x 13 x 80 m was prepared with a copper wire ring interposed so that the pieces did not contact each other, and the inner diameter was 20+a and the length was 1.
The mixture was placed in a hard glass test tube of OI+Il+1, and this test tube was placed in a 100-capacity autoclave. Add 30% of fluorinated halogenated hydrocarbon to the test tube in this autoclave.
A composition consisting of 6.9 parts of water, 0.815 parts of a predetermined stabilizer was added in an amount sufficient to completely immerse the test piece. Thereafter, it was placed in an autoclave, left in a hot air circulation constant temperature bath, and heated at 50° C. for 10 days. After standing and heating, the autoclave was taken out and allowed to cool to room temperature, and the aforementioned test piece was taken out. The surface change was measured for the test piece after heating, and the Ct- ion was measured for the heated composition, and the results are shown in Table 1.

Comparative Example 1 The method described in Example 1 was carried out without using the above stabilizer and the results are shown in Table 1.

Examples 6 to 5 A test tube containing the test piece described in Example 1 was placed in an autoclave with a pressure resistance of 100 ηd, and 20 parts of tetraethylene glycol dimethyl ether and 0.0 parts of a prescribed stabilizer were added.
Four parts of the mixture consisting of one part were placed inside the autoclave and outside the test tube, and the remaining amount was placed in the test tube, and the test piece was added so as to be immersed in X water. Thereafter, the atmosphere in the autoclave was completely replaced with nitrogen, the autoclave was sealed, and the autoclave was immersed in a dry ice/methanol mixture to cool to -20 to 60°C, and then cymonochlorodifluorochloride was poured into the charging port. Thereafter, the charging port was closed, the autoclave was placed in a hot air circulation constant temperature bath, and the autoclave was heated at 200° C. for 10 days.

After the required heating, the autoclave was taken out of the thermostatic bath, left to cool to room temperature, opened, and the surface change and corrosion rate of the test pieces that were post-treated by a well-known method were examined using the composition used in the test. Regarding the remaining liquid after returning to pressure, check the appearance,
PH, acid content, at-ion, and purity were measured and the results are shown in Table 2.

Comparative Example 2 Table 2 shows the results of the methods described in Examples 3 to 5 without using a stabilizer.

Claims (1)

[Scope of Claims] A fluorinated hydrocarbon composition containing a boric acid ester represented by the following general formula [I].