JPH0517380A - Stabilized 1,1-dichloro-1-fluoroethane composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition useful for blowing agent, refrigerant, etc., suppressing evolution of decomposition products, having excellent stability, containing a hydrocarbon having nitro group. CONSTITUTION:Preferably 0.01-5wt.% hydrocarbon having nitro-group such as nitromethane or nitortoluene is added to 1,1-dichloro-1-fluoroethane to give the objective composition.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to 1,1-dichloro-1
1-chloro-1-fluoroethane (hereinafter, R) which is a decomposition product of -fluoroethane (hereinafter, R141b)
151a), 1,1-dichloroethylene (hereinafter,
R1130a), 1-chloro-1-fluoroethylene (hereinafter referred to as R1131a), etc. are suppressed,
It relates to a stabilized R141b composition.

[0002]

2. Description of the Related Art Conventionally, trichlorofluoromethane (hereinafter referred to as R11) has been used in polyurethane foaming, turbo chillers, cleaning and the like. However, with regard to fully halogenated hydrocarbons, environmental problems for the ozone layer have been pointed out, and the development of alternative substances is urgently needed. R
11 R141b is regarded as a promising alternative substance.

[0003]

Although R141b has excellent stability, it is said that when various compounds coexist, the stability decreases and various decomposition products are produced. Examples of the coexisting substance that promotes decomposition include alcohols added for the purpose of enhancing solubility in a solvent, R1
41b may be a washing machine or a material to be washed, dirt components such as oil, or water. On the other hand, in the propellant, an alcohol added for the purpose of dissolving the water-soluble active ingredient or a container material with which R141b comes into contact can be mentioned.

Examples of coexisting substances in polyurethane foaming using R141b as a foaming agent include a polyol which is a raw material of polyurethane, a catalyst, a foam stabilizer, and a foaming machine in contact with R141b. Examples of coexisting substances when used as a refrigerant for a turbo refrigerator or the like include materials constituting a refrigerator and lubricating oil.

When the decomposition of R141b occurs, for example, in an aerosol product, the odor and the coloring of the liquid due to the oxidation of alcohol, the corrosion of the container by the hydrogen halide which is a decomposition product, and the foaming of polyurethane are caused. , Decrease in foaming ratio due to inactivation of catalyst, increase in viscosity of raw material polyol, yellowish brown color of product, and in refrigerator, due to hydrogen halide which is a decomposition product, mechanical corrosion and deterioration of lubricating oil An unfavorable problem such as a failure of occurs.

As a more serious problem, the decomposition of R141b results in R151a, R1130a, R1131a and the like. R151 generated as a result of decomposition of R141b
a is suspected to be carcinogenic, and R1130a and R1130a
1131a has a high acute toxicity. From the viewpoint of safety, it is extremely important to suppress the generation of these decomposition products.

[0007]

As a result of repeated studies of stabilizers of R141b in order to solve the above-mentioned problems, the present inventors have found that hydrocarbons having a nitro group are remarkably reduced in R141b.
It was found that the effect of suppressing the production of decomposition products can be exhibited, and the present invention has been completed.

That is, according to the present invention, by incorporating a hydrocarbon having a nitro group, R from R141b
The present invention provides a stabilized R141b composition that suppresses the generation of decomposition products such as 151a, R1130a, and R1131a.

Examples of the hydrocarbons having a nitro group in the present invention include known and well-known compounds. Nitromethane, nitroethane, 1-nitropropane, 2-
Nitroalkanes such as nitropropane, nitrobenzene, o-, m- or p-dinitrobenzene, trinitrobenzene, o-, m- or p-nitrotoluene, o-,
m- or p-ethylnitrobenzene, 2,3-, 2,4-, 2,5
-, 2,6-, 3,4- or 3,5-dimethylnitrobenzene, o
Aromatic hydrocarbons having a nitro group such as-, m- or p-nitroacetophenone, o-, m- or p-nitrophenol, o-, m- or p-nitroanisole are preferably selected. More preferred are aromatic hydrocarbons having a nitro group.

The content ratio of the nitro group-containing hydrocarbon which is the stabilizer in the present invention is not particularly limited, but R1
41b 0.001 to 10 wt%, preferably 0.01 to
5 wt% is suitable. Further, two or more kinds of the stabilizers of the present invention may be mixed and used, and further other stabilizers such as phenols, epoxy compounds and aromatic hydrocarbons such as α-methylstyrene and p-isopropenyltoluene may be added. Is also possible.

Further, as a method of adding the stabilizer, R14 is used.
It is effective to add it into 1b, but it is also effective to add it to other materials that coexist when R141b is used. For example, R
When 141b is used as a refrigerant, it can be used for naphthene-based, paraffin-based, alkylbenzene-based, poly-α-olefin-based, ester-based, polyether-based, etc. lubricating oils used to ensure the lubricity of the compressor. Addition is also effective.

When it is used as a foaming agent for foamed synthetic resin, addition to the foamed synthetic resin raw material is also effective.
As an example of the raw material, addition to a compound or polyisocyanate compound containing active hydrogen capable of reacting with an isocyanate group, and addition to both compounds are also effective.

Examples of the former compound containing active hydrogen include polyether type polyols, polyester type polyols, polyhydric alcohols, hydroxyl group-containing diethylene type polymers and the like. Examples of the latter polyisocyanate compound include aromatic, alicyclic, or aliphatic polyisocyanates containing two or more isocyanate groups, a mixture of two or more thereof, and a modified compound obtained by modifying them. There are polyisocyanates and the like.

[0014]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Example 1 Table 1 shows the stabilizing effect when R141b is used as a polyurethane foaming agent. The following mixed solution was prepared as a sample.

[0015] 50 parts by weight of polyol (a) 50 parts by weight of polyol (b) Polyisocyanate 136 parts by weight (Nippon Polyurethane Co., Ltd. Millionate MR-200) 3 parts by weight of catalyst (Polycat manufactured by Air Products and Chemicals) 2 parts by weight of foam stabilizer (SH-193 manufactured by Toray Silicone Co., Ltd.) 1 part by weight of pure water R141b 45 parts by weight

A predetermined amount of a stabilizer is mixed with this, and 200 mm
After forming the foam using a wooden box having dimensions of × 200 mm × 200 mm, a sample in the central portion was taken, and the amount of decomposition products generated in the foam was analyzed by gas chromatography to obtain a stabilizer. The inhibitory effect of the R141b decomposition product was measured.

The polyol (a) used in this test had a hydroxyl value of 45 obtained by reacting a mixture of shoe cloth and diethanolamine with propylene oxide and ethylene oxide.
The polyol (b) is a polyol having a hydroxyl value of 450 obtained by reacting toluenediamine with propylene oxide and ethylene oxide. The amount of the stabilizer added was wt% with respect to R141b in the sample, and the amount of the decomposition product was wt% with respect to R141b in the foam.

[0018]

[Table 1]

Example 2 The results as a refrigerant are shown in Table 2. The following mixed solution was prepared as a sample. Lubricating oil Sniso GS 50 parts by weight (Nippon Sun Oil Co., Ltd. naphthenic mineral oil) R141b 100 parts by weight Metal (3 cm □ × 3 mm Fe piece, Cu piece, Al piece each 1 piece)

A predetermined amount of a stabilizer was mixed with this, which was then sealed in a pressure-resistant metal container and heated to a temperature of 130 in a hot air circulation type constant temperature bath.
Hold at 0 ° C and perform a heating test for 14 days. After the heating test,
The suppression effect can be measured by analyzing the amount of decomposition products generated of R141b using gas chromatography.
The amount of the stabilizer added is wt% with respect to R141b in the sample, and the amount of the decomposition product is wt% with respect to R141b existing in the pressure-resistant metal container after the heating test.

[0021]

[Table 2]

[0022]

R1 stabilized according to the method of the present invention
The 41b composition is used as a foaming agent, a refrigerant, an aerosol, a solvent, etc.
The effect of suppressing the generation of the decomposition product of 1b is excellent.

Claims (2)

[Claims] 1. A 1,1-dichloro-1-fluoroethane composition which is stabilized by containing a hydrocarbon having a nitro group. 2. The stabilized 1,1-dichloro-1-fluoroethane composition according to claim 1, wherein the hydrocarbon having a nitro group is a nitroalkane or an aromatic hydrocarbon having a nitro group.