JPH03178940A - Production of pentafluorodichloropropanes - Google Patents

Abstract

PURPOSE:To economically obtain the subject specific compound in high yield and high selectivity without necessity of separation of catalyst by reacting fluorodichloromethane and tetrafluoroethylene in the presence of specific catalyst containing aluminum. CONSTITUTION:Fluorodichloromethane is reacted with tetrafluoroethylene in the presence of a catalyst expressed by the formula AlClxFyOz (x to z are numbers satisfying x+y+2z=3, 0<x<3, 0<=y<3 and 0<=z<3/2) preferably in a molar ratio of former : latter = 1 : 2-1 : 10 and at a temperature of from -20 deg.C to +100 deg.C to advantageously afford 1,1,1,2,2-pentafluoro-3,3- dichloropropane and 1,1,2,2,3-pentafluoro-1,3,-dichloropropane usable as a substitute for industrially important 1,1,2-trichloro-1,2,2-trifluoroethane with a slight effect to the earth environment.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is industrially important], C2-t'Jchloro1 2
．． Ll, 1,2 can be used as a substitute for 2-trifluoroethane and has little impact on the global environment.
．． 2-pentafluoro-3,3 dichloropropane (hereinafter referred to as R225ca) and 1,1,2,2.3-
Pentafluoro-1,3 dichloropropane (hereinafter referred to as R-
It is called 225cb. ).

[Prior Art] Conventionally, as a method for producing R225ca and C1), tetrafluoroethylene (hereinafter referred to as TFE) and fluorodichloromethane (hereinafter referred to as R-21) were reacted using a catalyst such as anhydrous aluminum chloride. °C~100
It is known that an industrial method of manufacturing the reaction at a temperature of 0C [US Pat. No. 2,462,402, Journal of the American Chemical Society]
rnal of the American Chemi
cal 5ociety) Volume 71 (1979), Collections of Czechoslovak Chemical Communications (Collections of Czechoslo)
vakia Chemical Communicati
ons) Volume 36 (1867)].

Furthermore, as a method for producing R225ca, a method is known in which tetrafluoroethylene is reacted with cesium fluorite in diglyme and then reacted with chloroform (see US Pat. No. 3.38L042).

However, using anhydrous aluminum chloride at 15 °C
The above method involves carrying out the reaction in a patch mode in an O-I crepe or glass reaction vessel at a reaction temperature of ~100 °C.
[1 Selectivity and yield of product (46-58%)
) was low, making it uneconomical from an industrial perspective. In addition, in order to separate the reaction product and the catalyst after the reaction is completed, the reaction product can be collected in a trap cooled under vacuum, or the reaction product can be separated after treating the catalyst with dilute hydrochloric acid.

There was a problem that it had to be done.

In addition, the method using cesium fluoride has a high selectivity,
Although the yield is good, the raw material, cesium fluoride, is very expensive, so it is not suitable at all for economical production on an industrial scale.

The above conventional method can only be carried out superficially in a batch manner, and the molar ratio of the reaction is specifically indicated as only 1:1.

[Disclosure of the Invention] As a result of detailed study of the production method described in the above-mentioned literature and intensive study on improving selectivity and yield, the inventors of the present invention discovered that R-21 in the presence of a specific catalyst containing aluminum. and T.F.
The present invention was completed based on the discovery that the yield and selectivity of R225ca and C10 can be dramatically improved by reacting ``l'':, and that this method eliminates the need for separation of the reaction product and catalyst. I ended up doing it.

That is, the present invention is based on the formula, 8QCQxFyO2 [where x, y: 16 and Z are
, Q<x<3.0≦y<3.0≦z<3/2. ] A method characterized by reacting fluorodichloromethane and tetrafluoroethylene in the presence of a catalyst represented by
, 1,1,2.2-pentafluoro-33-dichloropropane and 1,1,2.2.3-pentafluoro-l
This is a method for producing +3-dichloropropane.

In a preferred embodiment of the present invention, after filling a predetermined amount of catalyst, R-21 and TFE are allowed to flow at a predetermined molar ratio and flow rate, preferably in a gas phase, at a predetermined temperature. From the reaction mixture obtained from the outlet of the reaction tube, the desired R 225ca, c is separated and produced by a known method such as rectification.
b can be obtained.

The reaction mixture obtained from the outlet of the reaction tube contains R225ca and cb in a ratio of 20:80 to 80:20.

The chlorinated fluorinated alumina catalyst used in the present invention can be produced by reacting activated alumina with a chlorohydrocarbon, a chlorofluorohydrocarbon, a fluorohydrocarbon, hydrogen chloride, or a mixture thereof at 100 to 700'C. can be obtained, and is usually obtained as follows. After filling a reaction tube made of stainless steel, Hastelloy, or glass with a predetermined amount of alumina, the tube is heated to 300 to 500° C. under a stream of dry nitrogen to thoroughly dry the alumina. Thereafter, a predetermined temperature, usually 100 to 600° C., preferably 200 to 400° C., is obtained by flowing a predetermined fluorocarbon alone or in a mixture with hydrogen chloride gas or oxygen for a predetermined period of time. If the temperature of Freon treatment is lower than 1000C,
The time required for processing is too long and it is not practical.
When the temperature is higher than 0'C, carbon tends to adhere to the alumina surface and the activity tends to decrease. This reduction in activity due to the adhesion of carbon can also be prevented by the coexistence of oxygen or air, as shown in Japanese Patent Publication No. 61-27375.

The same method can be used when treating with hydrogen chloride gas.

The activated alumina is sufficiently dried by heating to 400 to 800'C under a stream of dry nitrogen. Thereafter, at a predetermined temperature, usually 300 to 700'C, hydrogen chloride gas is applied directly, or with an inert gas such as nitrogen or argon, or R-12
, R-21 and the like and distributed. Typical flow times are 3 to 10 hours.

Any commercially available alumina can be used as long as it is a porous alumina that is usually made of γ-alumina as a main component and is used for dehydration and catalyst purposes. For example, Neobead CSMHB, GB, D (Mizusawa Chemical Industry Co., Ltd.), activated alumina KHA, NKH (manufactured by Sumitomo Chemical Co., Ltd.), N K O3, etc. are used.

Furthermore, as the RI00 hydrocarbon or the RI'JO fluorohydrocarbon, those containing 1 to 3 carbon atoms, preferably 1 to 2 carbon atoms, are used, particularly preferably carbon tetrachloride. , fluorotrichloromethane, difluorodichloromethane, trifluorochloromethane, 1,1.2-
1-lichloro-122-trifluoroethane, l,
], , ]1-1-lichloro22.2-hlifluoroethane, 1. ．． 1,2.2tetrafluoro-1,2,-
dichloroethane, 11.1.2-tetrafluoro-2,
2-dichloroethane, 1.1,2.2-tetrachloro-
1,2-difluoroethane, 1. ．． 1,1. ．． 2-tetrachloro-22-difluoroethane is mentioned. Hydrogen-containing chlorohydrocarbons or chlorofluorohydrocarbons having 1 to 3 carbon atoms, preferably 1 to 2 carbon atoms, particularly preferably fluorodichloromethane, difluorochloromethane, ], 1 ], -) refluoro2. 2-dichloroethane, ], , ], , 2-) refluoro-1.2-dichloroethane, 1. , ] , 1-
1-lifluoro-2-chloroethane is mentioned.

In addition, the chlorinated fluorinated alumina catalyst is 20 to 4,50
Hydrogen fluoride at 'C, sulfur fluoride (SF4, SF, etc.) at 300-500'C, sulnoryl fluoride,
After treating thionyl fluoride with an inorganic fluoride such as ammonium fluoride (acidic ammonium fluoride, neutral ammonium fluoride, etc.) at 20 to 450°C, chlorofluorohydrocarbon, chlorohydrocarbon, or hydrogen chloride It can be produced by reacting with

In the present invention, the molar ratio of R-2] to TFE is 12 or more, preferably 1.2 to 110.

When the molar ratio is less than 1.2, R-21 becomes R-22 (difluorochloromethane), R-230 (difluorochloromethane)
, the rate of conversion to chloroform increases, which is undesirable. At a molar ratio of 1:2 or more, no significant difference in conversion rate or selectivity is observed. However, the larger the TFE ratio is, the more the TFE cycle amount increases, making it uneconomical. Therefore, the -I- limit is approximately 110.

When carrying out the method of the present invention in the gas phase, the raw material gas may be passed through as it is, but it may also be passed through after being diluted with an inert gas such as nitrogen or argon or a product of this reaction. The reaction pressure is not particularly limited. Although it is possible to carry out the process under reduced pressure, it is preferable to use a pressure below normal pressure, since the equipment usually becomes complicated. The upper limit is the pressure at which the product does not oxidize. Further, the reaction is generally carried out in a reaction tube made of SO8 or Hastelloy C, but if the reaction is carried out under dog sweat, it can also be carried out satisfactorily in a glass tube.

The reaction temperature is -20 to +150°C, preferably 20 to +150°C.
- temperature in the range of 100°C. reaction temperature is 150
When the temperature is higher than °C, the amount of side reaction products increases and the selectivity of target R 225ca and cb decreases.

The method of the invention can be carried out not only in the gas phase but also in the liquid phase. When flowing in a liquid phase, it is necessary to make TFE into a t-limb within the reaction system, and it is essential to carry out the reaction under pressurized conditions.

R-21, TFE, alumina, various chlorohydrocarbons, and chlorofluorohydrocarbons used in the present invention are all currently produced industrially.

[Effects of the Invention] According to the method of the present invention, R225ca and cb can be obtained in high yield and high selectivity. In addition, it is economical because catalyst separation treatment is unnecessary.

[Example] The present invention will be explained below with reference to Examples.

Jitsouso” - Neobead GB in a 5US316 reaction tube with an inner diameter of 20mm
It was filled with 40 m (!) and dried at 400°C for 6 hours in a stream of dry nitrogen. Thereafter, it was cooled to an internal temperature of 300°C, the nitrogen supply was stopped, and R-21 was allowed to flow at a flow rate of 75 cc/min. Analyze the reaction tube outlet gas using a gas chromatograph,
R-21 was continued to flow until the amount of carbon dioxide produced no longer decreased. Thereafter, it was cooled and the catalyst composition was changed to that of Woodbridge et al.
．． It was measured by a method similar to the thermal hydrolysis solution by 97+, )). When the internal temperature reached 30[deg.] C., R-21 was passed through in the gas phase at a flow rate of 20 cc/min and TFE at a flow rate of 60 cc/min (molar ratio ■, 3). After 3 hours, the pre-reaction gas was analyzed by gas chromatography, and the results shown in Table 1 were obtained. In the table, R-
224 represents dichlorotetrafluorofuropane).

Further, the catalyst compositions including those of other examples are shown in Table 2.

Example 2 Example 1 except that Neobead 1”GB was replaced with Neobead C and R-21 was replaced with difluorochloromethane (R-22).
The same procedure was repeated. The results are shown in Table 1.

Example 3 The same procedure as Example 1 was repeated except that R-21 was replaced with dichlorodifluoromethane (R-12). The results are shown in Table 1.

Lost Arashi 4 1 R-21 to tetrafluorodichloroethane (R114)
The same procedure as in Example 1 was repeated except that . The results are shown in Table 1.

Jitsukiiro 1 The same procedure as in Example 1 was repeated except that R-21 was replaced with carbon tetrachloride (CCC4). The results are shown in Table 1.

Block A-6- Neobeat GB made of activated alumina manufactured by Sumira Chemical Co., Ltd.
The same procedure as in Example 1 was repeated except that N K H3 was used. The results are shown in Table 1.

The same procedure as in Example I was repeated except that CB was replaced with activated alumina KI (available from Sumira Chemical Industries, Ltd.).

The reaction temperature of real noodles example round R-21 and TFE was changed from 30°C to -20°C.
The same procedure as in Example 1 was repeated except that . The results are shown in Table 1.

The same procedure as in Example 1 was repeated except that the reaction temperature of R-21 and TFE was changed from 300C to 80C. The results are shown in Table 1.

Example 10 The same procedure as Example 1 was repeated except that the molar ratio of R-2]/TFE was changed from 1:3 to 1:10. The results are shown in Table 1.

Example 11 The procedure of Example 1 was repeated except that the molar ratio of R-2+,/TFE was changed from 1:3 to 1:1. The results are shown in Table 1.

Sho Okumawari 1l - Reaction temperature of R-21 and TFE from 30°C to 160°C
The same procedure as in Example 1 was repeated except that . The results are shown in Table 1.

The reaction temperature of R-21 and TFE is set from 30'C to 200'C.
The same procedure as in Example 1 was repeated except that . The results are shown in Table 1.

Example 14 A reaction tube made of Hastelloy C with an inner diameter of 20 mrtr was filled with activated alumina (NKH3 manufactured by Sumira Chemical Co., Ltd.) 20zC and dried at 400'C for 6 hours under a stream of dry nitrogen.

After that, it was cooled to an internal temperature of 300°C, and nitrogen was added to 50*(!
/min, and dried hydrogen chloride residue was passed through the reaction tube at a flow rate of 100 m (1/min) while mixing. After 3 hours, heating was stopped and the reaction tube was cooled under a nitrogen stream to complete the preparation of the catalyst.

2.5 cc of the catalyst described above was packed into a glass reaction tube with an inner diameter of 8 mm, and R-21 was added at 10 cc/min and TFE was added at 60 cc/min in the gas phase.
After mixing in the reaction tube at a flow rate of cc/min (molar ratio 1:6), the mixture was allowed to flow. At this time, the temperature outside the reaction tube was adjusted so that the internal temperature of the catalyst layer was 55°C. 1 from the start of the reaction
After a period of time, the gas at the outlet of the reaction tube was analyzed by gas chromatography, and the results shown in Table 3 were obtained. In the table, R-224 represents dichlorotetrafluoropropane. Further, the catalyst compositions including those of Examples 15 to 24 are shown in Table 4.

Example 15 The drying temperature during catalyst preparation in Example 14 was set to 600°C.
1 The same procedure was carried out except that the temperature of the treatment with dry hydrogen chloride gas was changed to 500°C. The results are shown in Table 3.

Miokuyo 11 Drying la degree during catalyst preparation in Example 1/I was 8oo
'c, The same procedure was carried out except that the treatment temperature with dry hydrogen chloride gas was changed to 7000C. The results are shown in Table 3.

Example 17 The same procedure as in Example 14 was carried out except that the reaction temperature during the reaction between R-21 and TFE was changed to 100°C. The results are shown in Table 3.

The same procedure as in Example 15 was carried out except that the reaction temperature during the reaction between R-21 and TFE was changed to 100°C. The results are shown in Table 3.

The flow rates of R-21 and TFE during the reaction of R-21 and TFE in Example 15 were 150 cc/min and 10 cc/min, respectively (molar ratio 1; The same procedure was carried out except that 1) was changed. The results are shown in Table 3.

R during the reaction of R-21 and TFE in Example 15
-21 and TFE flow rates of 10 cc/min, respectively;
The same procedure was carried out except that the flow rate was changed to 100 cc/min (molar ratio 1:10). The results are shown in Table 3.

Example 21 The same procedure as in Example 15 was carried out except that the reaction temperature during the reaction with TFE such as R-21 was changed to 150°C.

The results are shown in Table 3.

4. The same procedure as in Example 15 was repeated except that Neobead CB (manufactured by Mizusawa Chemical Industry Co., Ltd.) was used instead of activated alumina. The results are shown in Table 3.

Harmful agriculture-l R during the reaction between R-21 and TFE in Example 15
-21 and TFE flow rates of 10 cc/min, respectively;
The same procedure was carried out except that the flow rate was changed to 30 cc/min (molar ratio 1:3). The results are shown in Table 3.

During the catalyst preparation in Example 15, hydrogen chloride (1
The same procedure was carried out except that the treatment was performed using a mixed gas of 00xL' minutes) and R-2] (100xL' minutes).

The results are shown in Table 3.

1. Anhydrous aluminum chloride in a silver-lined autoclave 5.
I prepared g. The autoclave was cooled in a solid carbon dioxide-acetone mixture, evacuated, and 52 g (0.5 mol) of fluorodichloromethane and 50 g (0.5 mol) of tetrafluoroethylene were distilled into it from the cylinder. Close the autoclave and do not stir.1
Heated at 00'C for 10 hours. Open the autoclave and
The product was removed and washed with a mixture of water and hydrochloric acid. 225
4.7 g (0.23 mol) of a mixture of ca and cb was obtained.

The yield was 46.3% based on R21. Table 1 shows the results of gas chromatograph analysis.

Table 2 Table 4

Claims (1)

[Claims] 1. Formula: AlClQ_xF_yO_z [In the formula, x, y and z are x+y+2z=3, 0<x
The number satisfies <3, 0≦y<3, and 0≦z<3/2. ] 1 characterized by reacting fluorodichloromethane and tetrafluoroethylene in the presence of a catalyst represented by
, 1,1,2,2-pentafluoro-3,3-dichloropropane and 1,1,2,2,3-pentafluoro-
Method for producing 1,3-dichloropropane.