WO2019003896A1

WO2019003896A1 - Production method for 2-chloro-1,1,1,2-tetrafluoropropane and/or 3-chloro-1,1,1,2-tetrafluoropropane, and production method for 2,3,3,3-tetrafluoropropene

Info

Publication number: WO2019003896A1
Application number: PCT/JP2018/022409
Authority: WO
Inventors: 英史塩田; 古田　昇二
Original assignee: Ａｇｃ株式会社
Priority date: 2017-06-27
Filing date: 2018-06-12
Publication date: 2019-01-03
Also published as: JPWO2019003896A1; JP7081596B2

Abstract

The purpose of the present invention is to provide: a method for efficiently producing 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) and/or 3-chloro-1,1,1,2-tetrafluoropropane (HCFC-244eb), which are advantageous starting materials for producing 2,3,3,3-tetrafluoropropene (HFO-1234yf), from industrially available materials; and an economically advantageous production method in which 1234yf is efficiently obtained thereby. The production method for HCFC-244bb and/or HCFC-244eb comprises reacting 1,1,1,2-tetrafluoropropane with chlorine. The production method for HFO-1234yf comprises obtaining HCFC-244bb and/or HCFC-244eb by said method and subjecting the obtained HCFC-244bb and/or HCFC-244eb to a dehydrochlorination reaction in the presence of a base and/or a catalyst.

Description

Process for the preparation of 2-chloro-1,1,1,2-tetrafluoropropane and / or 3-chloro-1,1,1,2-tetrafluoropropane and of 2,3,3,3-tetrafluoropropene Production method

The present invention relates to a process for producing 2-chloro-1,1,1,2-tetrafluoropropane and / or 3-chloro-1,1,1,2-tetrafluoropropane, and 2,3,3,3 To a process for producing tetrafluoropropene.

2,3,3,3-Tetrafluoropropene (CH ₂ CFCF—CF ₃ , HFO-1234yf) is a new alternative to the greenhouse gas 1,1,1,2-tetrafluoroethane (HFC-134a) As refrigerants, great expectations have been received in recent years.

As a method for producing 1234yf, Patent Document 1 discloses that 1,2-dichloro-2-fluoropropane (CH ₃ CClFCH ₂ Cl, HCFC-261ba) is chlorinated to 1,1,1,2-tetrachloro-2- The fluoropropane (CH ₃ CClFCCl ₃ , HCFC-241bb) is obtained and the 241bb is fluorinated to give 2-chloro-1,1,1,2-tetrafluoropropane (CF ₃ CFClCH ₃ , HCFC-244bb) A method of dehydrochlorinating the obtained 244bb to obtain 1234yf is described.

In patent document 1, 1234yf is obtained by reaction of 3 steps from 261ba which is a raw material, and improvement was desired by the point of productivity. In particular, a method for producing 1234yf with high productivity by efficiently producing 244bb has been desired.

Also from the structural isomer of 244bb, 3-chloro-1,1,1,2-tetrafluoropropane (CF ₃ CHFCH ₂ Cl, HCFC-244eb), 1234yf is obtained by the dehydrochlorination reaction as in 244bb. Be Therefore, if 244eb can be manufactured efficiently, 1234yf can be manufactured with high productivity.

On the other hand, there is known a method of dehydrogenating 1,1,1,2-tetrafluoropropane (CF ₃ CHFCH ₃ , HFC-254eb) to obtain 1234yf in a one-step reaction (see Patent Document 2). However, since the reaction is a high temperature reaction and an expensive catalyst is required, the method for producing 1234yf according to Patent Document 2 was not economically advantageous.

Patent No. 5482665 Patent No. 5886841

The present invention has been made from the above-mentioned viewpoints, and is an advantageous raw material for producing 2,3,3,3-tetrafluoropropene (HFO-1234yf) 2-chloro-1,1,1,1,2. A method for productively producing 2-tetrafluoropropane (HCFC-244bb) and / or 3-chloro-1,1,1,2-tetrafluoropropane (HCFC-244eb) from commercially available materials, And by that, it aims at provision of the economically advantageous manufacturing method which obtains 1234yf efficiently.

In the present specification, for halogenated hydrocarbons, the abbreviation of the compound is indicated in the parentheses after the compound name, but the abbreviation is used in place of the compound name as necessary. In addition, as the abbreviations, only numbers after the hyphen (-) and lower case letters of the alphabet may be used (for example, "1234yf" in "HCFO-1234yf").

The present invention provides a method of producing 244bb and / or 244eb, and a method of producing 1234yf, having the following configurations [1] to [11].
[1] A process for producing 244bb and / or 244eb, which comprises reacting 1,1,1,2-tetrafluoropropane (HFC-254eb) with chlorine (Cl ₂ ) to obtain 244bb and / or 244eb.
[2] The method according to [1], wherein the chlorine is used in a proportion of 0.01 to 3.00 mol with respect to 1 mol of the 254eb.
[3] The process according to [1] or [2], wherein the reaction of 254eb with chlorine is carried out at a temperature of 0 to 100 ° C.
[4] The process according to any one of [1] to [3], wherein the reaction of 254eb with chlorine is carried out under a gauge pressure at a pressure of 0.00 to 1.00 MPa.
[5] The method according to any one of [1] to [4], wherein the reaction of 254eb with chlorine is performed under irradiation of light having a wavelength of 200 to 750 nm.
[6] The method according to any one of [1] to [5], wherein the reaction of 254eb with chlorine is performed under irradiation of a fluorescent lamp or an LED lamp.
[7] The process according to any one of [1] to [6], wherein the reaction of 254eb with chlorine is carried out in the liquid phase in the presence of a solvent.
[8] The solvent is carbon tetrachloride, 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113), CF ₃ (CF ₂ ) _n CF ₃ (wherein n is the formula) , And represents an integer of from 3 to 6), a method of producing [7], comprising at least one selected from the group consisting of C 5-8 linear perfluoroalkyl compounds, hexachloroacetone, 244bb and 244eb .
[9] The production method of [7] or [8], wherein the solvent is used at a ratio of 1 to 4000% by mass with respect to the total amount of the 254eb and the chlorine.
[10] The process according to any one of [1] to [6], wherein the reaction of 254eb with chlorine is carried out in the gas phase.
[11] 1234yf, wherein 244bb and / or 244eb are obtained by the production method of any of [1] to [10], and the obtained 244bb and / or 244eb is dehydrochlorinated in the presence of a base and / or a catalyst. Manufacturing method.

According to the present invention, 244bb and / or 244eb, which are advantageous raw materials for producing 1234yf, can be produced with high productivity from industrially available 254eb. Furthermore, according to the present invention, 1234yf can be produced in an economically advantageous manner by using 244bb and / or 244eb thus obtained.

[Method of producing 244bb and / or 244eb]
The method for producing 244bb and / or 244eb of the present invention ("first embodiment") is carried out by a chlorination reaction in which 254eb is reacted with chlorine. The reaction to obtain 244bb and / or 244eb by the chlorination reaction of 254eb is a reaction represented by the following formula (1) (hereinafter also referred to as reaction (1)).

In the present specification, 244bb and / or 244eb mean either 244bb only, 244eb only, 244bb and 244eb. As used herein, chlorine refers to chlorine in the molecular state (Cl ₂ ).

The 244bb and / or 244eb obtained in the first embodiment is useful as a raw material for efficiently producing 1234yf, which is useful as a refrigerant with low environmental load.

<Manufacturing of 254eb>
254eb used in the first embodiment is a known compound known as a raw material or an intermediate for producing a fluorine-containing compound, and can be produced by a known method. 254eb is, for example, as shown in the following formula (2), 1,1-dichloro-2,3,3,3-tetrafluoropropene (CF ₃ CF = CCl ₂ , CFO-1214ya) in the presence of a catalyst It can be produced by reacting hydrogen. This reaction is included in the reduction reaction system for producing 1-chloro-2,3,3,3-tetrafluoropropene (CF ₃ CF = CHCl, HCFO-1224yd) or 1234yf from 1214 ya.

1214 ya which is a starting material of reaction shown by Formula (2) can be manufactured by a well-known manufacturing method. As a method for producing 1214 ya, for example, the method described in Japanese Patent No. 5582036 can be mentioned.

Incidentally, Z isomer and E isomer which are geometric isomers exist depending on the position of the substituent on the double bond of 1224yd. In the present specification, when a compound name or an abbreviation of a compound is used without particular notice, at least one selected from a Z form and an E form is indicated, and the compound name or the abbreviation of the compound is followed by (E) or When Z) is attached, it shows that it is E form or Z form of each compound. For example, 1224yd (Z) and 1224yd (E) indicate 1224yd Z form and E form, respectively.

A hydrogenation catalyst is used in the above-mentioned reaction of reacting 1214 ya with hydrogen. As the hydrogenation catalyst, a palladium catalyst is preferable, and the palladium catalyst is preferably used by being supported on a carrier. Not only palladium alone but also palladium alloy may be used as the palladium catalyst. In addition, it may be a mixture of palladium and another metal or a composite catalyst in which palladium and another metal are separately supported on a carrier. Examples of palladium alloy catalysts include palladium / platinum alloy catalysts and palladium / rhodium alloy catalysts.

Examples of the carrier include activated carbon and metal oxides (alumina, zirconia, silica and the like), and activated carbon is preferable in terms of activity, durability, and reaction selectivity. Examples of activated carbon include those obtained from plant materials (wood, charcoal, fruit shells, coconut shells, etc.), mineral materials (peat, lignite, coal, etc.), etc. From the viewpoint of catalyst durability, plant materials can be used. The obtained one is preferable, and coconut shell activated carbon is particularly preferable.

The reduction reaction of 1214 ya with hydrogen takes place in the gas phase. Specifically, the reaction tube is filled with a catalyst supporting carrier to form a catalyst layer, and 1214 ya gas and hydrogen gas are allowed to flow through the catalyst layer. 50 degreeC or more is preferable and, as for the temperature of the catalyst layer at the time of reaction, 60 degreeC or more is more preferable. The ratio of 1214 ya and hydrogen is adjusted appropriately. 1214 ya gas and hydrogen gas may be added to a dilution gas composed of nitrogen gas, a rare gas or the like to be used for the reaction.

The conditions in the above-mentioned reduction reaction may not necessarily be the conditions for increasing the selectivity of 254eb. Since 1224yd and 1234yf as intermediate products obtained in producing the target product 254eb from 1214ya of the raw material can be respectively isolated and used as valuables, the total selectivity of 1224yd, 1234yf and 254eb is high. It is preferable to carry out the reaction under the following conditions. Specifically, it is preferable to carry out the reaction under the conditions in which the formation of a super-reduced product of 254eb such as 1,1,1-trifluoropropane (CF ₃ CH ₂ CH ₃ , HFC-263fb) is suppressed.

The conversion rate refers to the ratio (mol%) of the amount of the raw material consumed in the reaction to the total amount of the raw material used in the reaction, and the selectivity is the amount of the target product produced relative to the total amount of product. The proportion (mol%) is said.

From the reaction product obtained by reacting 1214 ya with hydrogen, 254eb is isolated by a conventional separation method, for example, by distillation, and used as a raw material of the first embodiment. In the first embodiment, 254eb and impurities such as 1214ya, 1224yd and 1234yf are used if necessary, and 254eb composition containing 10% by mass or more of 254eb with respect to the total amount of the composition is used. It is also good. However, it is preferable to take out 1214ya, 1224yd and 1234yf which the said 254eb composition contains, respectively, and to use them as valuables.

When the 254eb composition contains 263fb, 263fb is 3,3,3-trifluoropropene (CF ₃ CH = CH ₂ , HFO-, which is difficult to separate from 1234yf by the following chlorination reaction and dehydrochlorination reaction: Preferably it is removed from the 254eb composition from producing 1243zf). From such a viewpoint, the content of 254eb with respect to the total amount of the composition in the 254eb composition is preferably 85% by mass to less than 100% by mass, and more preferably 90% by mass to 99% by mass.

<Production of 244bb and / or 244eb>
The first embodiment is a method of reacting 254eb with chlorine to produce 244bb and / or 244eb by reaction (1). In the first embodiment, 254eb obtained by the above-mentioned method can be used as the starting material 254eb. Note that the method for obtaining 254eb is not limited to this.

The ratio of each compound to the total amount of 244bb and 244eb in the target product 244bb and / or 244eb is not particularly limited. That is, in the first embodiment, the target products 244bb and / or 244eb may be 244bb alone, 244eb alone, or a mixture of 244bb and 244eb in any mixing ratio. As used herein, “selectivity of 244bb and / or 244eb” means the total selectivity of 244bb and 244eb.

When 244bb and / or 244eb obtained in the first embodiment are used as a raw material for the method for producing 1234yf by the dehydrochlorination reaction described below, both of 244bb and 244eb become 1234yf by the dehydrochlorination reaction, When both are obtained as a mixture, it is not necessary to separate them in particular. However, when the 244bb and 244eb are separated from the by-products described below by a usual method such as distillation, the 244bb and 244eb are easily separated due to the difference in boiling point. In that case, 244bb and 244eb may be obtained as single units.

Here, in the chlorination reaction of 254eb, a side reaction occurs in which the 244bb and / or 244eb obtained in the reaction (1) is further chlorinated together with the reaction (1), and 2,3-dichloro-1, 1,1,2-Tetrafluoropropane (HCFC-234bb), 3,3-Dichloro-1,1,1,2-tetrafluoropropane (HCFC-234ea), 2,3,3-Trichloro-1,1,3 1,2-tetrafluoropropane (HCFC-224ba), 1,1,1-trichloro-2,3,3,3-tetrafluoropropane (HCFC-224eb), 1,1,1,2-tetrachloro-2 Perchlorinated products such as 2,3,3,3-tetrafluoropropane (CFC-214bb) may be by-produced. The reaction in which these perchlorinated products are by-produced is represented by the following reaction formula.

In the first embodiment, the chlorination reaction of 254eb is preferably performed under conditions that suppress side reactions associated with such reaction (1) in order to increase the selectivity of 244bb and / or 244eb. Among the above perchlorinated products, 234bb, 234ea, 224ba and 224eb can be further dehydrochlorinated to produce 1214ya or 1224yd, and some of them may be produced as by-products. However, since 214bb is less useful, the smaller amount is preferable. Therefore, the chlorination reaction of 254eb in the first embodiment is particularly preferably performed under the condition that the amount of 214bb is reduced.

The chlorination reaction may be carried out in the liquid phase or in the gas phase. Hereinafter, the case where the chlorination reaction is performed in a liquid phase under light irradiation will be described as an example.

In the first embodiment, the ratio of 254eb to chlorine to be used, for example, the ratio of 254eb to chlorine supplied to the reactor, activates the reaction, suppresses the formation of by-products, in particular 214bb. , 0.01 to 3.00 mol of chlorine (Cl ₂ ) with respect to 1 mol of 254eb from the viewpoint of increasing the selectivity of 244bb and / or 244eb and the yield of 244bb and / or 244eb from 254eb 0.10 to 2.00 mol is more preferable, 0.20 to 1.60 mol is more preferable, and 0.50 to 1.50 mol is the most preferable.

The reaction temperature in the chlorination reaction is preferably 0 to 100 ° C., more preferably 5 to 60 ° C., from the viewpoint of increasing the reaction rate. The reaction pressure corresponds to the pressure in the reactor. The pressure in the reactor is preferably 0.00 to 1.00 MPa, more preferably 0.05 to 0.50 MPa, because the pressure can be efficiently produced. In order to improve the productivity, it is preferable to carry out the reaction under pressurized conditions. In the present specification, pressure refers to gauge pressure unless otherwise stated.

The chlorination reaction of 254eb (hereinafter, also simply referred to as “chlorination reaction”) is preferably performed under light irradiation from the viewpoint of increasing the reaction rate. The wavelength of light used for irradiation is preferably 200 to 750 nm, and more preferably 250 to 730 nm. If the light has a wavelength of 200 nm or more, the reaction of generating a by-product can be sufficiently suppressed, and if the light has a wavelength of 750 nm or less, the reaction proceeds sufficiently. Note that the light used for the irradiation may include light of a wavelength of less than 200 nm or light of a wavelength of more than 750 nm.

In the chlorination reaction, examples of a light source capable of efficiently irradiating the raw material with light having a wavelength of 200 to 750 nm include a fluorescent lamp, an LED light, an incandescent lamp, a high pressure mercury lamp, and a halogen lamp. A light source with large heat generation is not preferable because it becomes difficult to keep the internal temperature of the reactor low. When the internal temperature is high, the internal pressure rises, and it is necessary to increase the pressure resistance of the reactor, which is disadvantageous in cost. Also, if the internal temperature is high, side reactions are likely to occur. As a light source with small heat generation, a fluorescent lamp and an LED light are preferable.

When the chlorination reaction is carried out in the liquid phase, as a method of irradiating the raw material with light, the whole reaction liquid containing the raw material, the solvent used as needed, and the product can be uniformly irradiated through the reaction time. If it is a method, it will not be restricted in particular.

For example, a method of inserting a light source equipped with a jacket into the reaction solution and irradiating light on the raw material in the reaction solution from the inside of the reaction solution can be mentioned. The material of the jacket is preferably a material which transmits at least light of a wavelength useful for the above reaction, is inert to the components contained in the reaction solution, and is not easily corroded by these components. When the light source generates heat, depending on the reaction temperature, the jacket preferably has a cooling means.

In the chlorination reaction, 254eb and chlorine may be separately supplied to the reactor, or may be supplied in a premixed state. When a solvent is used, it is possible to dissolve the raw material component (254eb and chlorine) as the solvent, and it is inert with respect to the raw material component, and the target product (244bb and / or 244eb) is obtained by distillation or the like. The solvent which is easy to separate with) can be mentioned without particular limitation.

Specifically, the solvent has 5 to 6 carbon atoms represented by carbon tetrachloride, CFC-113, CF ₃ (CF ₂ ) _n CF ₃ (wherein n represents an integer of 3 to 6). Mention may be made of the linear perfluoroalkyl compounds of 8 and perhalo compounds such as hexachloroacetone. In addition, desired products 244bb and / or 244eb may be used as a solvent, and byproducts 234bb, 234ea, 224ba, 224eb and 214bb may be used as a solvent. As the solvent, one of these compounds may be used alone, or two or more thereof may be used in combination.

In the first embodiment, the solvent is preferably carbon tetrachloride which is low in cost and easy to separate from the desired product, or 244bb and / or 244eb without the need for separation.

The amount of solvent used for the chlorination reaction is not particularly limited as long as it can dissolve 244bb and / or 244eb to be produced, but specifically, it is preferably 1 to 4000% by mass, preferably 1 to 4000% by mass with respect to the raw material component (total amount of 254eb and chlorine) Is preferably in an amount of 50 to 3000% by mass.

The material of the reactor is not particularly limited as long as it is a material that is inert to the components contained in the reaction solution and is not easily corroded by these components. As a material of a reactor, iron, nickel, the alloy which has these as a main component, glass, resin etc. can be mentioned, for example. From the viewpoint of pressure resistance and corrosion resistance, the reaction container made of the above alloy in which the inner surface of the reactor is lined with a resin is preferable.

The chlorination reaction may be carried out by any of a semi-continuous system, a batch system and a continuous system. The reaction time can be appropriately adjusted by a general method according to each method. The supply of the raw materials to the reactor may be a method of supplying each predetermined amount for each component, or a method of supplying each component as a mixture containing each predetermined amount. When chlorine is supplied to the reactor as chlorine gas, the chlorine gas may be supplied diluted with an inert gas such as nitrogen as necessary.

In the case of a semi-continuous system, the feed is added at a constant rate as a component of the feed, or as a mixture of components of the feed, during the reaction. The addition of the raw material may be intermittent or continuous. In the case of a batch system, the raw materials are charged into a reactor together with a solvent and the like before the reaction and subjected to the reaction.

In the case of the continuous system, the raw material is continuously supplied into the reaction, for example, from the lower part of the reactor charged with the solvent. In the case of the continuous system, the product after completion of the reaction is continuously taken out from the top of the reactor, for example, by overflow and the like.

At the time of chlorination reaction, it is preferable to stir using a usual method, an apparatus, etc. also in any method of semi-continuous type, a batch type, and a continuous type.

When the chlorination reaction is carried out in the gas phase, it differs from the case in which it is carried out in the liquid phase in that it does not use a solvent, and that the temperature and / or pressure is in the gas phase. As conditions for carrying out the chlorination reaction in the gas phase, for example, conditions of a pressure of 0.00 to 1.00 MPa and a temperature of 0 to 100 ° C. can be mentioned.

As described above, the reaction product obtained by the chlorination reaction in which 254eb is reacted with chlorine is the target product 244bb and / or 244eb, unreacted raw materials, solvents, byproducts such as perchlorinated products, etc. Contains

As a method of separating desired products 244bb and / or 244eb from the product obtained, for example, after removing chlorine by washing with alkali, a method such as a method of removing solvent and by-products by distillation is usually used. Methods of separation of In addition, purification can be performed on 244bb and / or 244eb by distillation, and repeated distillation can be performed to obtain 244bb or 244eb of desired purity, or 244bb and 244eb of desired purity.

[Method of producing 1234yf]
The method for producing 1234yf of the present invention ("the second embodiment") provides 244bb and / or 244eb by the method of the first embodiment, and the obtained 244bb and / or 244eb is the presence of a base and / or a catalyst. It is the method of dehydrochlorination reaction below. The reaction for desalting 244bb and / or 244eb in the presence of a base and / or a catalyst is a reaction represented by the following formula (3) (hereinafter, also referred to as reaction (3)).

The starting material for the reaction (3) is either 244bb alone, 244eb alone, or a mixture of 244bb and 244eb.

Here, the raw material used to carry out the reaction (3) (hereinafter, also referred to as “the raw material for the reaction (3)”) is 244bb alone, 244eb alone, or a mixture of any of 244bb and 244eb In addition, it is conceptually preferable that it does not contain an impurity. However, the raw material of the reaction (3) may contain impurities such as perchlorinated products generated as a by-product of 244bb and / or 244eb in the first embodiment from the viewpoint of economy.

Among the perchlorinated products, 234bb, 234ea, 224ba and 224eb are dehydrochlorinated as shown in the formula (4) or the formula (5) under the condition that the reaction (3) desalts the 244bb and / or 244eb. To produce 1224yd or 1214ya. Specifically, 234bb and / or 234ea to 1224yd, and 224ba and / or 224eb to 1214ya, respectively, are generated. Also, 214bb does not inhibit 244bb and / or 244eb dehydrochlorination reactions.

When the raw material of the reaction (3) contains 244bb and / or 244eb and other impurities, the ratio of 244bb and / or 244eb to the total amount of impurities and 244bb and / or 244eb is 85% by mass or more and less than 100% by mass Is preferable, and 90 to 99 mass% is more preferable.

The raw material of the reaction (3) may contain 244bb and / or 244eb as a main component and at least one compound selected from 234bb, 234ea, 224ba and 224eb. The raw material of reaction (3) may further contain 214bb. In this case, the proportion of the total amount of the impurities 234bb, 234ea, 224ba, 224eb and 214bb is more than 0 mol% and 15 mol with respect to the total amount of the above impurities and 244bb and / or 244eb in order to efficiently produce 1234yf. % Or less is preferable, and 0.1 mol% or more and 7 mol% or less are more preferable.

The dehydrochlorination reaction of the reaction (3) in the second embodiment can be carried out by a conventionally known method. The reaction (3) can be carried out in the gas phase in the presence of a catalyst, for example, by the method described in Japanese Patent No. 5482665 (hereinafter, method (A)). The reaction (3) can be carried out in the presence of a base, in the gas phase or in the liquid phase (hereinafter, method (B)).

Specific examples of the catalyst in the method (A) include activated carbon, nickel catalyst (for example, nickel mesh), or a combination thereof. As other catalysts, palladium on carbon, palladium on alumina, etc. are used. These catalysts are used by being packed in the form of a fixed bed or fluidized bed in a reactor.

In the method (A), the reaction temperature is appropriately adjusted according to the pressure conditions during the reaction. As for the pressure condition of the reaction in the method (A), for example, when pressurization is required for the purpose of shortening the reaction time, the pressurization condition of 1.0 MPa or less, the internal pressure in the reactor and the normal pressure It is possible to set a reaction pressure condition of ̃1.0 MPa. From the viewpoint of industrial easiness of operation, it is preferable to carry out the reaction under normal pressure without pressure adjustment. When the method (A) is carried out at normal pressure, the reaction temperature is preferably 200 to 700 ° C., and more preferably 250 to 650 ° C. In 244bb, the reaction temperature is preferably 400 to 650 ° C., more preferably 450 to 600 ° C. In the case of 244eb, the reaction temperature is preferably 250 to 500 ° C., more preferably 300 to 400 ° C.

Method (A) can be carried out either batchwise or continuous flow, but continuous flow is preferred in terms of production efficiency. In addition, reaction time can be suitably adjusted with a general method by each mode. In addition, in the case of the method (A), it is preferable to add an operation of stirring using an ordinary method, an apparatus or the like.

Method (A) is usually carried out in the gas phase. The material of the gas phase reactor used for this reaction is, for example, stainless steel, Hastelloy (registered trademark) which is a nickel alloy, Inconel (registered trademark), Monel (registered trademark) or fluorine-based polymer Materials such as metal, glass, etc. can be mentioned.

The base in the method (B) is not particularly limited as long as the dehydrochlorination reaction of the reaction (3) can be carried out. The base is preferably at least one selected from the group consisting of metal hydroxides, metal oxides and metal carbonates. The base may be used alone or in combination of two or more.

Examples of the metal hydroxide include alkaline earth metal hydroxides and alkali metal hydroxides. As the alkaline earth metal hydroxide, magnesium hydroxide, calcium hydroxide, strontium hydroxide and barium hydroxide are preferable, and as the alkali metal hydroxide, lithium hydroxide, sodium hydroxide and potassium hydroxide are preferable.

Examples of the metal oxide include alkali metal oxides and alkaline earth metal oxides. As the alkali metal oxide, sodium oxide is preferable, and as the alkaline earth metal oxide, calcium oxide is preferable. The metal oxide may be an oxide of one metal, or a composite oxide of two or more metals.

As metal carbonate, alkaline earth metal carbonate, alkali metal carbonate and the like can be mentioned. Alkaline earth metal carbonates include carbonates of beryllium, magnesium, calcium, strontium, barium or radium. The alkali metal carbonates include carbonates of lithium, sodium, potassium, rubidium, cesium or francium.

The base is preferably at least one selected from metal hydroxides, and more preferably potassium hydroxide, sodium hydroxide or a combination of potassium hydroxide and sodium hydroxide.

The ratio of the base to 244bb and / or 244eb is 0.2 to 3.0 moles to 1 mole of 244bb and / or 244eb from the viewpoint of improving the conversion of 244bb and / or 244eb and the selectivity of 1234yf. Preferably, 0.5 to 2.5 mol is more preferable.

The method (B) is carried out in the gas phase or in the liquid phase. (B) When the process is carried out in the gas phase, the raw material is brought into the gas phase and brought into contact with a solid phase or a base solution containing a base and a solvent. When the process (B) is carried out in the liquid phase, the above base is present in the liquid phase in which the reaction is carried out. Hereinafter, the case where the method (B) is performed in the liquid phase will be described.

Method (B) is preferably carried out in the liquid phase in the presence of a base and a solvent. The solvent is not particularly limited as long as it can dissolve a predetermined amount of the base and does not contribute to the dehydrochlorination reaction. Water is preferable as a solvent for dissolving the above-mentioned base since it has high solubility in the above-mentioned base and is inactive to dehydrochlorination reaction. That is, in the method (B), the base is preferably used as an aqueous solution of the base. The aqueous solution of the base is preferably an aqueous solution of an alkali metal hydroxide, more preferably an aqueous solution of sodium hydroxide or an aqueous solution of potassium hydroxide.

The ratio of the mass of the base to the total mass of the solvent and the base is preferably 10 to 55% by mass, and more preferably 20 to 50% by mass. When the amount of the base is at least the above lower limit value, a sufficient reaction rate is easily obtained, and separation of the target product by two-layer separation is easily performed. If it is below the said upper limit, since a base will be easy to melt | dissolve sufficiently and a metal salt will not precipitate easily, it will be easy to become advantageous in an industrial process.

In the method (B), for example, a solution in which a base is dissolved in a solvent, 244bb and / or 244eb, and a compound involved in another reaction that is optionally used is supplied to a reactor to carry out the reaction. The resulting composition containing 1234yf is recovered from the reactor, but is optionally cooled via a cooler. Furthermore, it is preferable to recover the product from which water has been removed, if necessary, by passing it through a dewatering tower.

As a reactor, the well-known reactor used for dehydrochlorination reaction in liquid phase reaction is preferable. Examples of the material of the reactor include iron, nickel, alloys containing these as main components, and glass. If necessary, lining treatment such as resin lining or glass lining may be performed on the reactor. Further, it is preferable to provide a stirring means in the reactor and carry out the reaction while stirring so that the reaction is carried out in a state in which the raw materials, products, bases, solvents and the like are uniformly distributed in the reaction system.

In the method (B), the reaction temperature is the temperature in the reactor, preferably 40 to 120 ° C., more preferably 50 to 110 ° C. By setting the reaction temperature in the above range, the reaction rate and the conversion of 244bb and / or 244eb and the selectivity of 1234yf can be improved, and byproducts can be easily suppressed. In the 244bb, the reaction temperature is preferably 60 to 120 ° C., and more preferably 80 to 110 ° C. In the case of 244eb, the reaction temperature is preferably 40 to 80 ° C., more preferably 50 to 70 ° C.

In the method (B), the pressure in the reactor during the reaction is preferably 0.00 to 10.00 MPa, more preferably 0.05 to 5.00 MPa, and still more preferably 0.15 to 2.00 MPa. The pressure in the reactor is preferably at least the vapor pressure of 244bb and / or 244eb at the reaction temperature.

The method (B) can be carried out either semi-continuously, batchwise or continuously. In addition, reaction time can be suitably adjusted with a general method by each system. The reaction time is preferably 1 to 50 hours in a batch system, and preferably 1 to 3000 seconds in a continuous system, since it is easy to control the conversion of starting materials 244bb and / or 244eb and the selectivity of 1234yf. .

The method (B) may be carried out in the presence of a phase transfer catalyst as long as the reaction is not affected. A water-soluble organic solvent such as tetraglyme may be used as long as the reaction is not affected. In order to speed up the reaction, it is preferred to use a phase transfer catalyst.

Examples of phase transfer catalysts include quaternary ammonium salts, quaternary phosphonium salts, quaternary arsonium salts, sulfonium salts, crown ethers and the like, and quaternary ammonium salts, quaternary phosphonium salts and quaternary arsonium Salts and sulfonium salts are preferred, and quaternary ammonium salts are more preferred.

The quaternary ammonium salt is at least one selected from the group consisting of tetra-n-butylammonium chloride (TBAC), tetra-n-butylammonium bromide (TBAB) and methyltri-n-octylammonium chloride (TOMAC) Is preferred.

As the quaternary arsonium salt, triphenylmethylarsonium chloride is preferred. As a sulfonium salt, dodecyl methyl ethyl sulfonium chloride is preferable.

Examples of crown ethers include 18-crown-6, dibenzo-18-crown-6, and dicyclohexyl-18-crown-6.

The amount of phase transfer catalyst used is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5.0 parts by mass, and more preferably 0.1 to 3 parts by mass with respect to 100 parts by mass of 244bb and / or 244eb. 0 parts by mass is more preferred. When the amount of phase transfer catalyst is in the above range, a sufficient reaction rate is likely to be obtained. If it is out of the above range, it is difficult to obtain the reaction promoting effect, and the cost tends to be disadvantageous. When using a phase transfer catalyst, it is preferable to previously mix the phase transfer catalyst in 244bb and / or 244eb, and supply it to the reactor in the form of a mixed liquid with 244bb and / or 244eb.

When using a phase transfer catalyst, the reaction process, the reactor, and the materials of the reactor may be the same as in the case where the phase transfer catalyst is not used. In addition, reaction conditions such as the concentration of the base, the amount used, and the reaction temperature may be the same as in the case where the phase transfer catalyst is not used.

Method (B) supplies, for example, compounds involved in the reaction such as 244bb and / or 244eb, a base, if necessary, a solvent, and, if necessary, a phase transfer catalyst, to the reactor so that they become uniform The reaction is allowed to proceed by stirring to the desired temperature and pressure conditions.

When, for example, an aqueous solution of an alkali metal hydroxide or the like is used as a solution in which a base is dissolved in a solvent, the reaction system is separated into an aqueous phase and an organic phase. In such a case, instead of the phase transfer catalyst, for example, a water-soluble organic solvent such as tetraglyme is used to perform method (B) by compatibilizing the aqueous phase containing the base and the organic phase. Can. In the case of using a water-soluble organic solvent, it is preferable to carry out sufficient stirring in order to make the compound involved in the reaction in the reaction system homogeneous.

In the second embodiment, the method (A) has a high conversion rate of 244bb and / or 244eb and a high selectivity of 1234yf. In the method (B), although the conversion of 244bb and / or 244eb is slightly lower than the method (A), the selectivity of 1234yf is high, and the reaction temperature can be set lower.

The product obtained in the second embodiment includes unreacted 244bb and / or 244eb, byproducts, etc. in addition to the target product 1234yf. Components other than the target product 1234yf can be easily removed by a method such as distillation and separation.

When reaction (3) is carried out using a composition containing impurities such as 244bb and / or 244eb and 234bb, 234ea, 224ba, 224eb, 214bb, etc. as raw materials, the reaction from 234bb and / or 234ea is According to (4), 1224yd is produced from 224ba and / or 224eb, and according to reaction (5), 1214ya is produced as a by-product. Such 1224yd and 1214ya as by-products, as well as impurities contained in the raw material, for example, 214bb etc., can be easily separated from 1234yf by distillation.

According to the manufacturing method of the present invention, 244bb and / or 244eb can be manufactured from industrially available 254eb by an industrially practicable method. Moreover, 1234yf useful as a refrigerant with a small global warming potential from 244bb and / or 244eb as a raw material can be produced with high conversion and selectivity in an industrially practicable and economically advantageous method. .

EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited by these examples. Examples 1-6 are examples in the manufacture of 244bb and / or 244eb, and Examples 7-9 are examples in the manufacture of 1234yf.

[Analysis conditions]
In the following production of various compounds, composition analysis of the obtained reaction composition was performed using gas chromatography (GC). As a column, DB-1 (trade name, manufactured by Agilent Technologies, Ltd., length 60 m × inner diameter 250 μm × thickness 1 μm) was used.

[Production example of 254eb]
Hydrogen was allowed to react with 1214 ya using a U-shaped reaction tube having a catalyst layer packed with a catalyst-supporting carrier and a reactor equipped with a salt bath in which the U-shaped reaction tube is immersed. A palladium catalyst supporting activated carbon in which 0.5 parts by mass of palladium was supported with respect to 100 parts by mass of the activated carbon was used as a catalyst supporting carrier. The packing density of the catalyst supporting carrier in the catalyst layer was 0.73 g / cm ³ .

In the catalyst layer heated to 80 ° C. by adjusting the temperature of the salt bath, 1214 ya gas, hydrogen gas and nitrogen gas are caused to flow so that the total molar ratio is hydrogen / 1214 ya / nitrogen = 1/1/2. The reaction composition was recovered from the outlet of the reaction tube. The contact time of 1214 ya with the catalyst layer was 18 seconds, and the linear velocity u of 1214 ya was 7 cm / sec.

The recovered reaction composition contained 1214 ya, 1224 yd, 1234 yf, 254 eb and the like. From the reaction composition, 254eb was obtained by distillation.

[Example 1]
The 254eb obtained in the above preparation example was chlorinated to produce 244bb and 244eb.

First, a stainless steel autoclave (having an inner volume of 6.9 liters) equipped with a quartz tube and a jacket for transmitting light from a light source was cooled to 20.degree. After putting 2336 g of carbon tetrachloride (CCl ₄ ) and 103 g of 254eb in this autoclave (hereinafter referred to as a reactor), an LED lamp (Mitsubishi Electric Co., Ltd., LHT42N-G-E39 (product name), output) Chlorine gas was introduced into the reactor at a flow rate of 3.2 g / min while being irradiated with visible light from 40 W; wavelength of 400 to 750 nm of emitted light). As the reaction progressed, heat of reaction was generated, and the temperature in the reactor rose to 23.8 ° C. The flow rate of chlorine gas was introduced for 2 minutes, that is, 0.10 mol of chlorine was introduced per 1 mol of 254 eb, and light irradiation was continued until the temperature in the reactor became constant at 20 ° C. As for the pressure in the reactor, the pressure before chlorine supply was 0.045 MPa, and the pressure after chlorine supply, that is, the reaction pressure was 0.045 MPa.

After completion of the reaction, the obtained reaction solution was mixed with a 20% by mass aqueous solution of potassium hydrogen carbonate to be neutralized, and then a liquid separation operation was performed. After standing, the reaction composition 1 was recovered from the separated lower layer and subjected to GC analysis.

[Example 2]
The same reactor as that used in Example 1 was kept at 20 ° C., and 2336 g of carbon tetrachloride (CCl ₄ ) as a solvent was charged into the reactor, and 103 g of 254eb was charged. Thereafter, chlorine gas was supplied into the reactor at a flow rate of 3.2 g / min while being irradiated with visible light from an LED lamp (LHT42N-G-E39, manufactured by Mitsubishi Electric Corp., output 40 W). As the reaction progressed, heat of reaction was generated, and the temperature in the reactor (reaction temperature) rose to 22.6 ° C. The flow rate of chlorine gas was introduced for 10 minutes, that is, 0.50 mole of chlorine was introduced to 1 mole of 254eb, and the light irradiation was continued until the temperature in the reactor became constant at 20 ° C. As for the pressure in the reactor, the pressure before chlorine supply was 0.045 MPa, and the pressure after chlorine supply, that is, the reaction pressure was 0.085 MPa.

After completion of the reaction, the obtained reaction solution was mixed with a 20% by mass aqueous solution of potassium hydrogen carbonate to be neutralized, and then a liquid separation operation was performed. After standing, the reaction composition 2 was recovered from the separated lower layer and subjected to GC analysis.

[Example 3]
The same reactor as that used in Example 1 is maintained at 20 ° C., and 2336 g of carbon tetrachloride (CCl ₄ ) and 103 g of 254 eb are put therein, and then an LED lamp (Mitsubishi Electric Co., LHT42N-G-E39, output) Chlorine gas was introduced into the reactor at a flow rate of 3.2 g / min while emitting visible light from 40 W). As the reaction progressed, heat of reaction was generated, and the temperature in the reactor rose to 23.8 ° C. The flow rate of chlorine gas was introduced for 20 minutes, that is, 1.00 mole of chlorine was introduced to 1 mole of 254eb, and the light irradiation was continued until the temperature in the reactor became constant at 20 ° C. As for the pressure in the reactor, the pressure before chlorine supply was 0.045 MPa, and the pressure after chlorine supply, that is, the reaction pressure was 0.125 MPa.

After completion of the reaction, the obtained reaction solution was mixed with a 20% by mass aqueous solution of potassium hydrogen carbonate to be neutralized, and then a liquid separation operation was performed. After standing, the reaction composition 3 was recovered from the separated lower layer and subjected to GC analysis. After removing the chlorine by washing the reaction composition 3 with alkali, the solvent and byproducts were removed by distillation to obtain 244bb of purity 99.9% and 244eb of 99.9%.

[Example 4]
The same reactor as that used in Example 1 is maintained at 20 ° C., and 2336 g of carbon tetrachloride (CCl ₄ ) and 103 g of 254 eb are put therein, and then an LED lamp (Mitsubishi Electric Co., LHT42N-G-E39, output) Chlorine gas was introduced into the reactor at a flow rate of 3.2 g / min while emitting visible light from 40 W). As the reaction progressed, heat of reaction was generated, and the temperature in the reactor rose to 23.8 ° C. The flow rate of chlorine gas was introduced for 30 minutes, that is, 1.50 mol of chlorine was introduced per 1 mol of 254 eb, and light irradiation was continued until the temperature in the reactor became constant at 20 ° C. As for the pressure in the reactor, the pressure before chlorine supply was 0.045 MPa, and the pressure after chlorine supply, that is, the reaction pressure was 0.165 MPa.

After completion of the reaction, the obtained reaction solution was mixed with a 20% by mass aqueous solution of potassium hydrogen carbonate to be neutralized, and then a liquid separation operation was performed. After standing, the reaction composition 4 was recovered from the separated lower layer and subjected to GC analysis.

[Example 5]
The same reactor as that used in Example 1 is maintained at 20 ° C., and 2336 g of carbon tetrachloride (CCl ₄ ) and 103 g of 254 eb are put therein, and then an LED lamp (Mitsubishi Electric Co., LHT42N-G-E39, output) Chlorine gas was introduced into the reactor at a flow rate of 3.2 g / min while emitting visible light from 40 W). As the reaction progressed, heat of reaction was generated, and the temperature in the reactor rose to 23.8 ° C. The flow rate of chlorine gas was introduced for 40 minutes, that is, 2.00 mol of chlorine was introduced per 1 mol of 254 eb, and the light irradiation was continued until the temperature in the reactor became constant at 20 ° C. As for the pressure in the reactor, the pressure before chlorine supply was 0.045 MPa, and the pressure after chlorine supply, that is, the reaction pressure was 0.198 MPa.

After completion of the reaction, the obtained reaction solution was mixed with a 20% by mass aqueous solution of potassium hydrogen carbonate to be neutralized, and then a liquid separation operation was performed. After standing, the reaction composition 5 was recovered from the separated lower layer and subjected to GC analysis.

[Example 6]
The same reactor as that used in Example 1 is maintained at 50 ° C., 2430 g of carbon tetrachloride (CCl ₄ ) and 103 g of 254 eb are put therein, and then an LED lamp (Mitsubishi Electric Co., LHT42N-G-E39, power output) Chlorine gas was introduced into the reactor at a flow rate of 3.2 g / min while emitting visible light from 40 W). As the reaction progressed, heat of reaction was generated, and the temperature in the reactor rose to 52.8 ° C. The flow rate of chlorine gas was introduced for 20 minutes, that is, 1.00 mole of chlorine was introduced to 1 mole of 254eb, and the light irradiation was continued until the temperature in the reactor became constant at 50 ° C. As for the pressure in the reactor, the pressure before chlorine supply was 0.075 MPa, and the pressure after chlorine supply, that is, the reaction pressure was 0.165 MPa.

After completion of the reaction, the obtained reaction solution was mixed with a 20% by mass aqueous solution of potassium hydrogen carbonate to be neutralized, and then a liquid separation operation was performed. After standing, the reaction composition 6 was recovered from the separated lower layer and subjected to GC analysis.

The reaction conditions of Examples 1 to 6 and the GC analysis results of the resulting reaction compositions 1 to 6 are shown in Table 1.
In Table 1, the conversion of 254eb is a ratio of the amount of 254eb consumed in the reaction to the amount of 254eb supplied to the reactor, and is a molar conversion value (unit: mol%). Moreover, the selectivity of each compound is a ratio of each compound with respect to the total amount of the reaction composition, and is a molar equivalent value (unit: mol%).

As can be seen from Table 1, according to Examples 1 to 6, the target 244bb and 244eb can be obtained with high selectivity.

[Example 7]
Activated carbon (8.50 g) was charged as a catalyst into a 1/2 inch radius SUS 316 gas phase reaction vessel. The reaction vessel was fitted with a preheater and the temperature was maintained at 450 ° C. To this gas phase reactor, 244bb obtained in Example 3 above was supplied from a cylinder maintained at a temperature of 65 ° C. via a mass flow controller and a preheater. The temperature in the line from the cylinder through the mass flow controller to the preheater was kept at 65 ° C. to prevent 244bb from condensing.

244bb supplied to the gas phase reactor is dehydrochlorinated by contacting with an activated carbon catalyst under the condition of a reaction temperature of 450 ° C. while passing through the gas phase reactor (passing time: 60 seconds) to be 1234yf . The reaction composition containing 1234yf was recovered from the outlet of the gas phase reactor. GC analysis of the recovered reaction composition showed that the conversion rate of 244bb was 95%, the yield of 1234yf was 85%, and the selectivity was 89%.

[Example 8]
A 0.1 L reactor equipped with a thermocouple and a stirring blade was placed in a thermostat and kept at 80 ° C. Into this reactor, 61 g of 48% by mass KOH aqueous solution, 40 g of 244bb obtained in Example 3 above and 0.85 g of tetra-n-butylammonium bromide (TBAB) were added, the reactor was closed, and a pressure test was conducted. The The stirring blade was rotated at 400 rpm, and reaction was carried out for 3 hours. Then, the reactor was taken out of the thermostatic bath and cooled to 0 ° C. with ice water to stop the reaction, and the reaction composition was recovered. As a result of conducting GC analysis of the recovered reaction composition, the conversion rate of 244bb was 61%, the yield of 1234yf was 61%, and the selectivity was 100%.

[Example 9]
A 0.1 L reactor equipped with a thermocouple and a stirring blade was placed in a thermostat and kept at 60 ° C. Into this reactor, 60 g of 40 mass% KOH aqueous solution, 32 g of 244eb obtained in Example 3 above, and 0.69 g of tetra-n-butylammonium bromide (TBAB) were added, the reactor was closed, and a pressure test was conducted. The The stirring blade was rotated at 400 rpm and reaction was carried out for 30 minutes, then the reactor was taken out of the thermostatic bath and cooled to 0 ° C. with ice water to stop the reaction, and the reaction composition was recovered. As a result of carrying out GC analysis of the recovered reaction composition, the conversion of 244eb was 99%, the yield of 1234yf was 99%, and the selectivity was 100%.

According to Example 7, it is possible to obtain the desired 1234yf with high conversion and high selectivity without using an expensive metal catalyst. Further, according to Examples 8 and 9, it is possible to obtain the target 1234yf with a high conversion rate and a high selectivity at a low reaction temperature without using an expensive metal catalyst.

Claims

Reaction of 1,1,1,2-tetrafluoropropane with chlorine to give 2-chloro-1,1,1,2-tetrafluoropropane and / or 3-chloro-1,1,1,2-tetrafluoropropane A process for producing 2-chloro-1,1,1,2-tetrafluoropropane and / or 3-chloro-1,1,1,2-tetrafluoropropane,
The method according to claim 1, wherein the chlorine is used in a ratio of 0.01 to 3.00 mol with respect to 1 mol of the 1,1,1,2-tetrafluoropropane.
The process according to claim 1 or 2, wherein the reaction of 1,1,1,2-tetrafluoropropane with chlorine is carried out at a temperature of 0 to 100 属 C.
The method according to any one of claims 1 to 3, wherein the reaction of 1,1,1,2-tetrafluoropropane with chlorine is performed at a pressure of 0.00 to 1.00 MPa at a gauge pressure. .
The process according to any one of claims 1 to 4, wherein the reaction of 1,1,1,2-tetrafluoropropane with chlorine is performed under irradiation of light having a wavelength of 200 to 750 nm.
The method according to any one of claims 1 to 5, wherein the reaction of 1,1,1,2-tetrafluoropropane with chlorine is performed under irradiation of a fluorescent lamp or an LED lamp.
The method according to any one of claims 1 to 6, wherein the reaction of 1,1,1,2-tetrafluoropropane with chlorine is carried out in the liquid phase in the presence of a solvent.
The solvent is carbon tetrachloride, 1,1,2-trichloro-1,2,2-trifluoroethane, CF 3 (CF 2 ) n CF 3 (wherein n represents an integer of 3 to 6) ), C 5-8 linear perfluoroalkyl compounds, hexachloroacetone, 2-chloro-1,1,1,2-tetrafluoropropane and 3-chloro-1,1,1,2- The production method according to claim 7, comprising at least one selected from the group consisting of tetrafluoropropane.
The method according to claim 7 or 8, wherein the solvent is used in a proportion of 1 to 4000% by mass based on the total amount of the 1,1,1,2-tetrafluoropropane and the chlorine.
The method according to any one of claims 1 to 6, wherein the reaction of 1,1,1,2-tetrafluoropropane with chlorine is carried out in the gas phase.
A 2-chloro-1,1,1,2-tetrafluoropropane and / or 3-chloro-1,1,1,2-tetrafluoropropane by the method according to any one of claims 1 to 10. And removing the obtained 2-chloro-1,1,1,2-tetrafluoropropane and / or 3-chloro-1,1,1,2-tetrafluoropropane in the presence of a base and / or a catalyst. Process for producing 2,3,3,3-tetrafluoropropene to be reacted with hydrogen chloride.