JPH0543487A - Method for suppressing decomposition of hydrogen-containing halogenated hydrocarbon - Google Patents

Abstract

PURPOSE:To obtain a method for suppressing decomposition of hydrogen- containing fluorocarbon during preservation of hydrogen-containing fluorocarbon, in a process using a hydrogen-containing fluorocarbon or during use of a product for a long period of time. CONSTITUTION:A hydrogen-containing fluorocarbon is blended with (1) at least one nitro compound and (2) at least one alicyclic unsaturated hydrocarbon or (1) at least one nitro compound, (2) at least one alicyclic unsaturated hydrocarbon and (3) at least one selected from a group consisting of an aliphatic unsaturated hydrocarbon, an epoxy compound, an ether compound, a phenol compound, an ester compound, an alkylamine compound, a cyclic nitrogen compound and an unsaturated alcohol compound to suppress decomposition of a hydrogen- containing fluorocarbon.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for suppressing the decomposition of hydrogen-containing halogenated hydrocarbons, and more specifically to the hydrogen-containing halogenated hydrocarbons containing a mixture of a nitro compound and an alicyclic unsaturated hydrocarbon. Thus, the present invention relates to a method for suppressing decomposition of hydrogen-containing halogenated hydrocarbon.

[0002]

2. Description of the Related Art Halogenated hydrocarbons (hereinafter referred to as CFCs) completely substituted with fluorine and chlorine are
It depletes the ozone layer, which has led to limited use and production. Therefore, the development of new CFCs that can replace these is highly desired, and as a typical example thereof, hydrogen-containing halogenated hydrocarbons (hereinafter referred to as hydrogen-containing CFCs) that have no or little risk of ozone layer depletion are regarded as promising. There is. However, hydrogen-containing CFCs are generally said to be less stable than conventional CFCs.

As a method for stabilizing hydrogen-containing CFCs, a method of adding a hydrocarbon containing a nitro group (Japanese Patent Laid-Open No. HEI-1)
No. 129944), a method of adding a hydrocarbon containing a nitro group and an epoxy compound (JP-A-1-12).
No. 8945) has been proposed.

The above-mentioned publications disclose methods for stabilizing hydrogen-containing CFCs, which are unstable when used in the coexistence state with a compound having an alcoholic hydroxyl group. For example, a solvent or a propeller is used. A method for stabilizing hydrogen-containing CFCs in the coexistence of alcohol added to the component, and a method for stabilizing hydrogen-containing CFCs in the presence of polyol in the urethane raw material in urethane foaming using hydrogen-containing CFCs as a foaming agent are described. Has been done. Since hydrogen-containing CFCs are generally unstable, they are easily decomposed in the presence of water or a metal, or by the action of light, heat, etc., except when used in the presence of a compound having an alcoholic hydroxyl group. Therefore, the hydrogen-containing fluorocarbon is gradually decomposed not only during its storage but also during the process and the product using the hydrogen-containing fluorocarbon. However, the above-mentioned known method does not describe the decomposition suppressing effect under such a condition that the hydrogen-containing CFC is decomposed, and in fact, there is a case where such a decomposition suppressing effect is small. Therefore, there is a strong demand for the development of a new decomposition suppression method capable of maintaining a stable state even under the various conditions described above.

The inventors of the present invention have conducted intensive studies in view of the above-mentioned state of the art, and as a result, have studied hydrogen-containing CFCs with a mixture of a nitro compound and an alicyclic unsaturated hydrocarbon, or with another compound. When blending the blended mixture as a stabilizer, regardless of the presence or absence of the compound having an alcoholic hydroxyl group, under various conditions, that is, during storage,
It has been found that the effect of suppressing the decomposition of hydrogen-containing CFCs can be achieved for a long period of time both during use and under product conditions.

That is, the present invention provides the following method for suppressing the decomposition of hydrogen-containing halogenated hydrocarbons: 1 Hydrogen-containing halogenated hydrocarbon containing (1) at least one nitro compound and (2) a fat A method for suppressing decomposition of a hydrogen-containing halogenated hydrocarbon, which comprises blending at least one kind of cyclic unsaturated hydrocarbon (hereinafter, this combination may be referred to as a first composition). 2 Hydrogen-containing halogenated hydrocarbon (1) at least one kind of nitro compound, (2) at least one kind of alicyclic unsaturated hydrocarbon and (3) aliphatic unsaturated hydrocarbon, epoxy compound, ether compound, phenol Compound, ester compound, alkylamine compound, cyclic nitrogen compound, and at least one selected from the group consisting of unsaturated alcohol compounds are blended, and a method for suppressing decomposition of hydrogen-containing halogenated hydrocarbons (hereinafter, this combination will be described). May be referred to as the second composition). In the present specification,
References to "%" and "parts" shall mean "wt%" and "parts by weight", respectively.

The following are examples of hydrogen-containing halogenated hydrocarbons to which the present invention is applied. Hydrogen-containing chlorofluorohydrocarbon (HCFC) ... Dichloromonofluoromethane (HCFC-21; hereinafter simply referred to as "2
1 ”), monochlorodifluoromethane (22), dichlorotrifluoroethane (123), monochlorotetrafluoroethane (124), dichloromonofluoroethane (141), monochlorodifluoroethane (142). Hydrogen-containing fluorohydrocarbon (HFC): difluoromethane (32), trifluoromethane (23), difluoroethane (152), trifluoroethane (143), tetrafluoroethane (134), heptafluoropropane (227), hexafluoropropane (236). When isomers exist in the above-mentioned hydrogen-containing halogenated hydrocarbon, each isomer alone or as a mixture of isomers can be a subject of the present invention.

Examples of the (1) nitro compound used in the method of the present invention are as follows. A. Aromatic nitro compounds: nitrobenzene, nitrotoluene (o-, m-, p-), chloronitrobenzene (o-, m-, p
-), Nitrobenzyl alcohol (o-, m-), 4-chloro-3-nitrobenzotrifluoride, m-dinitrobenzene, 2,4-dinitrofluorobenzene, 2,4-dinitrochlorobenzene, p-nitrophenetol , 3-nitrostyrene, 1,2,3-trichloro-4-nitrobenzene, nitrophenol (o-, m-, p-), nitroanisole (o-, m-, p-), fluoronitrobenzene (m-, p-
), 2-chloro-6-nitrotoluene, p-nitrophenetol, dinitrotoluene (2,4-, 2,6-,
3,4-), 2,4-dinitroanisole, 2,4-dinitrophenol, o-nitrobenzyl alcohol, 4-
Nitrocatechol etc. B. Aliphatic nitro compounds: nitromethane, nitroethane, nitropropane (1-, 2-), etc. These nitro compounds can be used alone or in admixture of two or more. Among these nitro compounds, nitrobenzene, nitromethane, nitrostyrene and nitrocatechol are more preferable.

Examples of the (2) alicyclic unsaturated hydrocarbon compound used in the method of the present invention are as follows.
Styrene, methylstyrene (α-, β-, p-), vinyltoluene, p-isopropenyltoluene, p-diisopropenylbenzene, p-isopropenylxylene, divinylbenzene (m-, p-), cyclohexadiene, Cyclopentadiene, α-pinene, α-limonene, furan,
1,1-diphenylethylene and the like. These alicyclic unsaturated hydrocarbon compounds can also be used alone or in combination of two or more. Among these alicyclic unsaturated hydrocarbon compounds, methylstyrene (α-, β
-, P-), p-isopropenyltoluene and p-diisopropenylbenzene are more preferred.

In the first composition, usually (1) the nitro compound is 0.05 per 100 parts of the hydrogen-containing halogenated hydrocarbon.
~ 5 parts and (2) alicyclic unsaturated hydrocarbon compound 0.05 to 5 parts (however, the total of both components is 0.1 to 5 parts).
(About 5 parts). A more preferable ratio is (1) about 0.1 to 0.5 part of a nitro compound and (2) 0.1 to 0.5 part of an alicyclic unsaturated hydrocarbon compound to 100 parts of a hydrogen-containing halogenated hydrocarbon. (However, the total of both components is about 0.2 to 1 part). If the proportions of (1) nitro compound and (2) alicyclic unsaturated hydrocarbon compound are too small, the desired effect cannot be achieved, whereas
If the amount is too large, no further substantial improvement in effect is observed.

In the second composition, (1) at least one nitro compound and (2) at least one alicyclic unsaturated hydrocarbon, and (3) an aliphatic unsaturated hydrocarbon, an epoxy compound, At least one selected from the group consisting of ether compounds, phenol compounds, ester compounds, alkylamine compounds, cyclic nitrogen compounds and unsaturated alcohol compounds is used in combination. Specific examples of these combined compounds (3) are shown below. Aliphatic unsaturated hydrocarbons ... isoprene, 2-methyl-2-
Butene, 2,3-dimethylbutadiene, 2,3-dimethyl-1-butene, 1,3-pentadiene, 1-hexene, myrcene and the like. Among these aliphatic unsaturated hydrocarbon compounds, isoprene and 2,3-dimethylbutadiene are more preferable. Epoxy compound: 1,2-butylene oxide, isobutylene oxide, propylene oxide, epichlorohydrin, styrene oxide, glycidol and the like. Among these epoxy compounds, 1,2-butylene oxide and epichlorohydrin are more preferable. Ether compounds: 1,4-dioxane, 1,2-dimethoxyethane, phenylglycidyl ether, allylglycidyl ether, furan, 2,5-dihydrofuran, furyl and the like. Among these ether compounds, 1,4-dioxane, phenylglycidyl ether and furan are more preferable. Phenolic compounds: phenol, cresol (o-, m-, p
-), Methoxyphenol (o-, m-, p-), thymol,
2,6-di-t-butyl-p-cresol, pt-butylphenol, eugenol, isoeugenol, anisole, isosaflor, pt-butylcatechol and the like. Among these phenol compounds, p-t-butylcatechol and 2,6-di-t-butyl-p-cresol are more preferable. Ester compounds: ethyl acrylate, vinyl acrylate, vinyl methacrylate, methyl acetate, methyl salicylate, etc. Among these ester compounds, ethyl acrylate and vinyl methacrylate are more preferable. Alkylamine compound: diisopropylamine, diallylamine, pentylamine, hexylamine, ethylenediamine, etc. Among these alkylamine compounds,
Diisopropylamine and diallylamine are more preferred. Cyclic nitrogen compound ... Methylpyrrole (N-, 2-, 3
-), Vinylpyridine (2-, 4-), N-methylmorpholine, benzotriazole and the like. Among these cyclic nitrogen compounds, N-methylpyrrole and 4-vinylpyridine are more preferable. Unsaturated alcohol: propargyl alcohol, 3-methyl-1-buten-3-ol, 2-methyl-3-butyne-
3-all etc. Among these unsaturated alcohols, propargyl alcohol is more preferable. These combined compounds can be used alone or in combination of two or more kinds.

In the second composition, usually (1) the nitro compound is 0.05 per 100 parts of the hydrogen-containing halogenated hydrocarbon.
~ 5 parts, (2) alicyclic unsaturated hydrocarbon compound 0.0
About 5 to 5 parts and about 0.05 to 5 parts of the combined compound (3) (however, the total of the three components is about 0.15 to 5 parts) are blended. A more preferable ratio is (1) the nitro compound 0.1 to 0.1 to 100 parts of the hydrogen-containing halogenated hydrocarbon.
About 5 parts, (2) alicyclic unsaturated hydrocarbon compound 0.1 to
About 0.5 parts and about 0.1 to 1 part of the combined compound (3) (however, the total of the three components is about 0.3 to 1 part).
If the blending ratio of any one of these three components is too low, the desired effect is not achieved, while if it is too high, no substantial improvement in the effect is observed.

A stable composition comprising the above-mentioned (1) nitro compound and (2) alicyclic unsaturated hydrocarbon compound, or (1) nitro compound, (2) alicyclic unsaturated hydrocarbon compound and concomitant compound (3). The agent component is a blending time for freon, a blending means depending on the purpose of use, intended use of the hydrogen-containing freon, other substances mixed with the freon, temperature conditions during storage, production and use of the product. Etc. can be arbitrarily selected.

[0014]

EFFECTS OF THE INVENTION According to the method of the present invention, the stability of the hydrogen-containing CFC can be remarkably enhanced during storage, use, and production of the CFC. Further, the method of the present invention can suppress the decomposition of hydrogen-containing fluorocarbons even under the condition that the method is used in the coexistence state with the compound containing an alcoholic hydroxyl group. Therefore, the present invention is extremely useful in practice as a method for suppressing the decomposition of hydrogen-containing CFCs used as a foaming agent, a refrigerant, a cleaning agent, a propellant, a fire extinguishing agent, a solvent, a dry etching agent, etc.

[0015]

EXAMPLES Examples and comparative examples will be shown below to further clarify the characteristics of the present invention.

Example 1 The components were mixed in the proportions shown in Table 1 below to prepare a mixed solution for producing a rigid polyurethane. Table 1 Polyol 100 parts Catalyst 2 parts Foam stabilizer 2 parts Pure water 2 parts Foaming agent (or CFC 40 parts or CFC containing hydrogen) Note: Polyol ... Trademark "RX-500", Sanyo Chemical Co., Ltd. Catalyst ... Trademark "U-CAT1000", a foam stabilizer manufactured by San Abbott Co., Ltd ... Trademark "SH-193", Toray Silicone Co., Ltd.
Made

A predetermined amount of the stabilizer was mixed with the obtained mixed liquid, which was then sealed in a pressure vessel made of iron and kept at 60 ° C. in a constant temperature bath to carry out a heating test for one month. In heating test,
When the hydrogen-containing CFC or CFC is decomposed, a specific decomposed gas is generated. Therefore, the concentration thereof was measured by a gas chromatograph, and the hydrogen-containing CFC or CFC decomposition inhibitory ability during storage was judged.

Further, 102 parts of crude polyisocyanate (trademark "MR-100", manufactured by Nippon Polyurethane Industry Co., Ltd.) was added to 100 parts of the mixed solution obtained above, and urethane foam was produced by hand mixing, and then 1 day. Aged
Then, the urethane foam after aging for one day was cut into a 10 cm square and vacuum packed with an aluminum laminate pack. Next, the vacuum-packed urethane foam was crushed with a press, and the concentration of the decomposition gas generated by the exothermic reaction was measured by gas chromatography to determine the ability to suppress decomposition of hydrogen-containing CFCs or CFCs during the foam formation reaction.

Further, the urethane foam vacuum-packed in the same manner as above was kept at 90 ° C. in a constant temperature bath, and the decomposition gas concentration after heating for 2 weeks was measured by a gas chromatograph to measure hydrogen-containing CFCs or CFCs during aging. The ability to suppress the degradation of was determined.

Further, a storage test was conducted on the assumption of use as a refrigerant. That is, hydrogen-containing CFCs 123 were placed in a 100 ml pressure-resistant glass container containing iron, copper and aluminum test pieces (5 mm x 50 mm x 2 mm each) at the same time.
And paraffinic mineral oil mixture (80/20; weight ratio)
Put 100 g, Comparative Examples 5-8 and 3B of Table 3A
Add a prescribed amount of the stabilizer shown in Examples 1 to 12 of the table,
It was heated at 0 ° C for 2 weeks to determine its ability to suppress decomposition.

Tables 2-A to 2-C show the kinds of foaming agents, the kinds of stabilizers, and the amount (parts) of the stabilizer added to 100 parts of the foaming agent. In addition, Tables 3-A to 3
-Table C shows the decomposition gas generation concentration (based on the blowing agent) at each test stage. Table 2-A Table Comparative example Comparative amount of foaming agent Stabilizer Addition amount 1 11 None -2 11 Nitrobenzene 1.0 3 11 Nitromethane 1.0 4 11 α-Methylstyrene 1.0 5 123 None-6 123 Nitrobenzene 1.0 7 123 Nitromethane 1.0 8 123 α-Methylstyrene 1.0 9 11 Nitrobenzene 0.5 α-Methylstyrene 0.5 10 11 Nitromethane 0.5 p-Isopropenyltoluene 0.5 11 11 4-Nitrocatechol 0. 5 p-diisopropenylbenzene 0.5

Table 2-B Example Examples Foaming agent stabilizing agent Addition amount 1 123 Nitrobenzene 0.5 α-Methylstyrene 0.5 2 123 Nitromethane 0.5 p-Isopropenyltoluene 0.5 3 123 4-Nitro Catechol 0.5 p-diisopropenylbenzene 0.5 4 123 nitrobenzene 0.1 α-methylstyrene 0.1 isoprene 0.5 5 123 nitromethane 0.2 p-isopropenyltoluene 0.1 2,3-dimethylbutadiene 0 .5 6 123 3-nitrostyrene 0.1 p-diisopropenylbenzene 0.1 1,2-butylene oxide 0.5 7 123 m-chloronitrobenzene 0.1 α-methylstyrene 0.1 pt-butylcatechol 0.38 123 4-Nitrocatechol 0.1 p-isopropenyltolu 0.1 1,4-dioxane 0.5 9 123 m-nitrotoluene 0.1 α-methylstyrene 0.1 methyl acrylate 0.3 10 123 o-nitroanisole 0.1 p-diisopropenylbenzene 0.1 Diallylamine 0.3 11 123 p-nitrophenetol 0.1 α-methylstyrene 0.1 4-vinylpyridine 0.3 12 123 3,4-dinitrotoluene 0.1 p-diisopropenylbenzene 0.1 propargyl alcohol 0.3

Table 2-C Example Examples Foaming agent stabilizing agent Addition amount 13 141b Nitrobenzene 0.5 α-methylstyrene 0.5 14 141b Nitromethane 0.5 p-isopropenylbenzene 0.5 15 141b 4-Nitro Catechol 0.5 p-diisopropenylbenzene 0.5 16 141b nitrobenzene 0.1 α-methylstyrene 0.1 isoprene 0.5 17 141b nitromethane 0.2 p-isopropenyltoluene 0.1 2,3-dimethylbutadiene 0 .5 18 141b 3-nitrostyrene 0.1 p-diisopropenylbenzene 0.1 1,2-butylenedioxide 0.5 19 141b m-chloronitrobenzene 0.1 α-methylstyrene 0.1 pt-butyl. Catechol 0.3 20 141b 4-Nitrocatechol 0.1 p-isop Lopenyltoluene 0.1 1,4-dioxane 0.521 141b m-nitrotoluene 0.1 α-methylstyrene 0.1 methyl acrylate 0.322 141b o-nitroanisole 0.1 p-diisopropenylbenzene 0 .1 diallylamine 0.3 23 141b p-nitrophenetol 0.1 α-methylstyrene 0.1 4-vinylpyridine 0.3 24 141b 3,4-dinitrotoluene 0.1 p-diisopropenylbenzene 0.1 propa Gil alcohol 0.3

Table 3-A Decomposition gas generation concentration (ppm) Comparative example During storage During reaction During aging During storage 1 20000 350 6400-2 2300 120 5800-3 5800 380 8500-4 4800 800 240 6000-5 3600 470 4100 1100 6 170 70 1300 450 7 500 500 250 2900 250 8 430 310 310 3200 520 9 1800 220 5500-10 3200 340 7800-11 2500 300 5800-Note: Comparative Examples 1 to 4 and 9 to 11 (using CFC-11).
Then, dichloromonofluoromethane (HCFC-21)
There has occurred. In Comparative Examples 5 to 8 (using HCFC-123), 1-chloro-2,2,2-trifluoroethane (HCFC-13
3a) occurred.

[0025] The 3-B Table decomposition gas generated Concentration (ppm) Example savings built in reactions during aging during storage in 1 60 0 450 120 2 120 10 780 40 3 100 0 590 100 4 80 0 120 80 5 150 20 200 20 6 40 0 70 50 7 7 60 0 150 80 8 8 100 0 80 40 40 9 60 0 140 140 100 10 120 0 160 160 140 11 100 0 120 120 120 12 120 10 150 80 Note: Examples 1 to 12 (using HCFC-123) Then 1
-Chloro-2,2,2-trifluoroethane (HCFC
-133a) occurred.

[0026] The 3-C Table decomposition gas generated Concentration (ppm) Example savings in built in reactions during aging 13 90 0 800 14 180 0 1200 15 140 0 750 16 120 0 200 17 200 0 220 18 150 0 80 19 80 0 180 20 150 0 80 80 21 150 0 160 22 22 180 0 250 23 150 0 100 24 24 140 0 160 Note: In Examples 13 to 24 (using HCFC-141b), 1-chloro-1-fluoroethylene was mainly generated. did.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Ide 1-1 Nishiichitsuya, Settsu-shi, Osaka Daikin Industries, Ltd. Yodogawa Manufacturing Co., Ltd. (72) Tatsumi Tsuchiya Nishiichitsuya 1-1, Settsu-shi, Osaka Daikin Industries Yodogawa Manufacturing Co., Ltd. (72) Inventor Katsuji Fujiwara 1-1 Nishiichitsuya, Settsu-shi, Osaka Daikin Industry Co., Ltd. Yodogawa Manufacturing Co., Ltd.

Claims (2)

[Claims] 1. A hydrogen-containing halogenated hydrocarbon, characterized in that (1) at least one nitro compound and (2) at least one alicyclic unsaturated hydrocarbon are blended with the hydrogen-containing halogenated hydrocarbon. Method of suppressing decomposition of. 2. A hydrogen-containing halogenated hydrocarbon containing (1) at least one nitro compound, (2) at least one alicyclic unsaturated hydrocarbon, and (3) an aliphatic unsaturated hydrocarbon, an epoxy compound, A method for suppressing decomposition of a hydrogen-containing halogenated hydrocarbon, which comprises blending at least one selected from the group consisting of an ether compound, a phenol compound, an ester compound, an alkylamine compound, a cyclic nitrogen compound and an unsaturated alcohol compound.