JPH0217139A - Production of difluoropropane - Google Patents

Abstract

PURPOSE:To obtain the title compound in high purity under a relatively mild condition by fluorinating a dihalogenated propane or monohalogenated propene in the presence of a specific fluorinating catalyst such as halide containing a specific element such as aluminum. CONSTITUTION:A dihalogenated propane or monohalogenated propene is fluorinated with hydrogen fluoride in the presence of a fluorinating catalyst comprising a halide or oxide containing one or more elements selected from Al, Cr, Mg, Ca, Ba, Sr, Fe, Ni, Co, Mn, Sb, Nb and Ta in a gas phase under normal pressure-under pressure or under reduced pressure or in a liquid phase under pressure at 50-550 deg.C, preferably 50-450 deg.C to advantageously prepare high- quality difluoropropane such as 2,2-difluoropropane useful as cooling agent, propellant of aerosol, gaseous insulating material, solvent, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to the production of difluoropropane, which is useful as a refrigerant, an aerosol propellant, a gaseous insulator, a solvent, etc., and as a starting material for the production of other fluorocarbons. It is about law.

[Conventional technology and issues] Difluoropropane exists in several isomers.

Among them, the conventional method for producing 2,2-difluoropropane having a boiling point of -0,1"C is to use antimony trifluoride as a fluorinating agent and bromine as a catalyst in a liquid phase at about 2,2"C. A method of fluorinating 2-dichloropropane and a method of directly introducing gaseous propyne into liquid hydrogen fluoride cooled to about -80°C and reacting it have been proposed. The reaction is a batch process, so the yield is low and the efficiency of the reaction operation is not high.

[Means for Solving the Problems] The present invention provides 2,2-difluoropropane (CH3CF
The purpose of this invention is to provide a new method for producing difluoropropanes such as 2CH3).

That is, the present invention provides 1,2-dichloropropane (CH
2C1CHCI CH3), 2.2-dichloropropane, dihalogenated propanes such as 2-chloro-2-fluoropropane, or monohalogenated propenes such as 2-chloropropene and 2-fluoropropene with AI, Cr
+ MgS Ca, Ba% Sr, Fe.

In the gas or liquid phase with hydrogen fluoride in the presence of a fluorination catalyst consisting of a halide or oxide containing at least one element selected from the group consisting of N1, Co, Mn, Sb, Nb and Ta. The present invention provides a method for producing difluoropropane, which is characterized by fluorination.

1.2-dichloropropane (boiling point: 96°C), 2.2
-dichloropropane (70,5°C), 2-chloro-2
- halogenated propanes such as fluoropropane (35.2°C), 2-chloropropene (boiling point = 22.5°C),
Halogenated propenes such as 2-fluoropropene (boiling point 2-17°C) are known and available compounds.

The fluorination catalyst of the present invention includes AI, Cr, Mg,
Ca, Sr, Ba, Fe, Ni, C
Halides or oxides such as chlorides containing at least one element selected from O, Mn, Sb, Nb, and Ta can be used. If a gas phase fluorination method is adopted, oxides such as At2(h, Cr2(:h, MgO, CaO, etc.) and their composite oxides are used; if a liquid phase fluorination method is adopted, TaF5, NbCl5, 5bC1s
It is preferable to use halides such as.

Any of the above catalysts may be treated with hydrogen fluoride, CCI 3F, CC12F2, or CCt 2 before being subjected to the reaction.
At least 1 fluorine atom, such as F CCt F 2
It is desirable to activate it with halogenated methane, halogenated ethane, etc.

The fluorination reaction is suitably carried out in the gas phase under intermediate pressure, increased pressure, or reduced pressure, or under increased pressure in the liquid phase at a temperature range of 50 to 550°C, particularly preferably 50 to 450°C. The proportions of hydrogen fluoride and halogenated propane or halogenated propene feedstock can vary widely. However, stoichiometric amounts of hydrogen fluoride are usually used to replace chlorine atoms or add to double bonds.
Significantly more than stoichiometric amounts of hydrogen fluoride may be used, for example 4 moles or more, based on the total number of moles of starting materials.

The contact time is usually 0.1 to 0.1 when the reaction is carried out in the gas phase.
When the reaction is carried out in the liquid phase, the residence time in the reactor is about 300 seconds, particularly preferably 5 to 30 seconds, and about 0.1 to 10,000 minutes, particularly preferably 10 to 1,000 minutes2. is necessary.

To maintain catalyst activity, zero oxygen or chlorine is added to the raw material.
．． They can coexist in an amount of 1 to 10%.

The reaction format may be either liquid phase or gas phase; if gas phase reaction is used, continuous operation is possible.

The desired products of the invention may be separated by conventional methods such as fractional distillation.

As described above, the present invention provides a method for producing highly pure difluoropropane by fluorinating dihalogenated propane or monohalogenated propene.

[Example] Examples of the present invention will be shown below.

Preparation example 1.100g of special grade reagent Al(NO3)3.9H20,
125g of Cr (N03) 3.9 N20 and 40g
M g (N03) 2.6H20 was dissolved in 2.59 g of water, and while stirring, 2.000 g of a 28% by weight ammonium hydroxide aqueous solution was added to heated 412 water to form hydroxide. A precipitate was obtained. This was separated from P, washed with pure water, and dried, and then calcined at 450°C for 5 hours to obtain an oxide powder. This was molded into a cylindrical shape with a diameter of 5++n+ and a height of 5cm using a tablet molding machine. The catalyst thus obtained was activated by fluorination at 200 to 400°C in a hydrogen fluoride/nitrogen mixed gas flow before the reaction.

Example 1 Inconel 600 with an inner diameter of 2.54 cm and a length of 100 cm
A fluorination reactor was prepared by filling a U-shaped reaction tube with 200 μm of the fluorination catalyst prepared as shown in the Preparation Example. 50t9 of 2,2-dichloropropane, which was sufficiently vaporized as halogenated propane, by hydrogen fluoride at 100all/min.
The reactant was fed at 350°C and reacted at 350°C, and the reactant was collected in a trap cooled to -78°C. After removing the acid content of the collected material, the composition was analyzed by gas chromatography and GC.
-As a result of analysis using MS and "F-NMR, 2,2
-difluoropropane, 2-fluoropropene and 2
The production of -chloro-2-fluoropropane was confirmed.

Example 2 The reaction was carried out under the same conditions as in Example 1 except that 1,2-dichloropropane was used instead of 2,2-dichloropropane as the halogenated propane.
It was collected in a trap cooled to C. After removing the acid content of the collected material, the composition was analyzed and it was confirmed that 2,2-difluoropropane, 2-fluoropropene, 2-chloro-2-fluoropropane, 2-chloropropene, and allyl chloride were produced. .

Example 3 A reaction was carried out under the same conditions as in Example 1, except that 2-chloro-2-fluoropropane was used instead of 2,2-dichloropropane as the halogenated propane.

The reaction was collected in a tiger knob cooled to -78°C.

After removing the acid content of the collected material, we analyzed the composition and found that 2.
Production of 2-difluoropropane and 2-fluoropropene was confirmed.

Example 4 Using 2-chloropropene as the halogenated propene,
The reaction was carried out under the same conditions as in Example 1 except that the reaction temperature was 320°C. The reactant was collected in a trap cooled to -78°C. After removing the acid content of the collected material, the composition was analyzed and it was confirmed that 2,2-difluoropropane, 2-fluoropropene, and 2-chloro-2-fluoropropane were produced.

Example 5 600 g of 2-chloro-2-fluoropropane was placed in a Hastelloy C autoclave having an internal volume of IQ, and 20 g of antimony pentachloride was added thereto. After raising the temperature to 120° C., hydrogen fluoride was supplied at a rate of 50 g/hour for 6 hours, and the reaction was continued for an additional 20 hours.

The reaction product was collected in a trap cooled to -78°C.

After removing the acid content of the collected material, the composition was analyzed in the same manner as in Example 1, and as a result, the production of 2,2-difluoropropane was confirmed.

[Effects of the Invention] As shown in the Examples, the present invention provides that difluoropropane can be produced under relatively mild conditions by fluorinating diA halogenated propane or monohalogenated propene raw materials with hydrogen fluoride. 0 effects.

Dai [111 people (masu sokushi) 1 fu 1 child

Claims (1)

[Scope of Claims] 1. Dihalogenated propane or monohalogenated propene is Al, Cr, Mg, Ca, Ba, Sr, Fe, N
Production of difluoropropane, characterized by fluorination in the presence of a fluorination catalyst consisting of a halide or oxide containing at least one element selected from the group consisting of i, Co, Mn, Sb, Nb and Ta. Law. 2. The production method according to claim 1, wherein the fluorination reaction is carried out in a gas phase under normal pressure, increased pressure, or reduced pressure, or in a liquid phase under increased pressure at a temperature range of 50°C to 550°C.