JP7081596B2 - Methods for producing 2-chloro-1,1,1,2-tetrafluoropropane and / or 3-chloro-1,1,1,2-tetrafluoropropane, and 2,3,3,3-tetrafluoropropene. Production method - Google Patents

Description

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

2,3,3,3-tetrafluoropropene (CH ₂ = CF-CF ₃ , HFO-1234yf) is a new alternative to the greenhouse gas 1,1,1,2-tetrafluoroethane (HFC-134a). As a refrigerant, great expectations have been placed in recent years.

As a method for producing 1234yf, Patent Document 1 describes 1,1,1,2-tetrachloro-2- by chlorinating 1,2-dichloro-2-fluoropropane (CH ₃ CClFCH ₂ Cl, HCFC-261ba). Fluoropropane (CH ₃ CClFCCl ₃ , HCFC-241bb) was obtained, and the 241bb was fluorinated to obtain 2-chloro-1,1,1,2-tetrafluoropropane (CF ₃ CFClCH ₃ , HCFC-244bb). A method for obtaining 1234yf by dehydrochlorinating the obtained 244bb is described.

In Patent Document 1, 1234yf was obtained from 261ba, which is a raw material, by a three-step reaction, and improvement in productivity was desired. In particular, a method for producing 1234yf with high productivity by efficiently producing 244bb has been desired.

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

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

Japanese Patent No. 5482665 Japanese Patent No. 5886841

The present invention has been made from the above viewpoint and is an advantageous raw material for producing 2,3,3,3-tetrafluoropropene (HFO-1234yf), 2-chloro-1,1,1, A method for productively producing 2-tetrafluoropropane (HCFC-244bb) and / or 3-chloro-1,1,1,2-tetrafluoropropane (HCFC-244eb) from industrially available materials. And thereby, it is an object of the present invention to provide an economically advantageous manufacturing method for efficiently obtaining 1234yf.

In the present specification, for halogenated hydrocarbons, the abbreviation of the compound is described in parentheses after the compound name, but the abbreviation is used instead of the compound name as necessary. Further, as an abbreviation, only the number after the hyphen (-) and the lowercase alphabetic part (for example, "1234yf" in "HCFO-1234yf") may be used.

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

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

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

As used herein, 244 bb and / or 244 eb is any of the cases of 244 bb only, 244 eb only, 244 bb and 244 eb. In the present specification, chlorine refers to chlorine in a 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 having a 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, in the presence of a catalyst on 1,1-dichloro-2,3,3,3-tetrafluoropropene (CF ₃ CF = CCl ₂ , CFO-1214ya) as shown in the following formula (2). It can be produced by reacting with 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) and 1234yf from 1214ya.

1214ya, which is the starting material of the reaction represented by the formula (2), can be produced by a known production method. Examples of the method for producing 1214ya include the method described in Japanese Patent No. 5582036.

In 1224yd, there are Z-form and E-form which are geometric isomers depending on the position of the substituent on the double bond. When the compound name or the abbreviation of the compound is used in the present specification, at least one selected from Z-form and E-form is shown, and (E) or (E) or ( When Z) is attached, it indicates that it is an E-form or a Z-form of each compound. For example, 1224yd (Z) and 1224yd (E) represent the Z and E forms of 1224yd, respectively.

A hydrogenation catalyst is used in the above reaction of reacting 1214ya with hydrogen to reduce it. As the hydrogenation catalyst, a palladium catalyst is preferable, and the palladium catalyst is preferably supported on a carrier and used. The palladium catalyst may be not only palladium alone but also a palladium alloy. Further, it may be a composite catalyst in which a mixture of palladium and another metal or palladium and another metal are separately supported on a carrier. Examples of the palladium alloy catalyst include a palladium / platinum alloy catalyst and a palladium / rhodium alloy catalyst.

Examples of the carrier include activated carbon and metal oxides (alumina, zirconia, silica, etc.), and activated carbon is preferable from the viewpoint of activity, durability, and reaction selectivity. Examples of activated carbon include those obtained from plant raw materials (wood, charcoal, fruit husks, coconut husks, etc.), mineral material raw materials (peat, sub-coal, coal, etc.), etc. The obtained one is preferable, and coconut shell activated carbon is particularly preferable.

The reduction reaction of reacting 1214ya with hydrogen is carried out in the gas phase. Specifically, the reaction tube is filled with a catalyst-supporting carrier to form a catalyst layer, and 1214ya gas and hydrogen gas are circulated through the catalyst layer. The temperature of the catalyst layer during the reaction is preferably 50 ° C. or higher, more preferably 60 ° C. or higher. The ratio of 1214ya and hydrogen is adjusted as appropriate. A diluted gas composed of nitrogen gas, a rare gas, or the like may be added to 1214ya gas and hydrogen gas to be subjected to the reaction.

The conditions in the reduction reaction do not necessarily have to be the conditions for increasing the selectivity of 254 eb. Since 1224yd and 1234yf as intermediate products obtained when producing the target product 254eb from the raw material 1214ya can be isolated and used as valuable resources, respectively, the total selectivity of 1224yd, 1234yf and 254eb is high. It is preferable to carry out the reaction under the conditions of Specifically, it is preferable to carry out the reaction under conditions under which the formation of a hyperreduced product of 254 eb such as 1,1,1-trifluoropropane (CF ₃ CH ₂ CH ₃ , HFC-263 fb) 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 ratio of the amount of the target product produced to the total amount of the product. Percentage (mol%).

From the reaction product obtained by reacting 1214ya with hydrogen, 254 eb is isolated by a usual separation method, for example, by distillation, and used as a raw material of the first embodiment. In the first embodiment, a 254 eb composition containing 254 eb and impurities such as 1214ya, 1224yd, and 1234yf and containing 254 eb in an amount of 10% by mass or more based on the total amount of the composition is used, if necessary. May be good. However, it is preferable that 1214ya, 1224yd and 1234yf contained in the above 254eb composition are taken out and used as valuable resources, respectively.

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

<Manufacturing of 244bb and / or 244eb>
The first embodiment is a method of reacting 254 eb with chlorine to produce 244 bb and / or 244 eb by the reaction (1). In the first embodiment, as the starting material 254eb, 254eb obtained by the above-mentioned method can be used. The method of obtaining 254 eb 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 product 244bb and / or 244eb may be a simple substance of 244bb, a simple substance of 244eb, or a mixture of 244bb and 244eb in any mixing ratio. As used herein, the "selectivity of 244bb and / or 244eb" means the total selectivity of 244bb and 244eb.

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

Here, in the chlorination reaction of 254 eb, a side reaction in which the 244 bb and / or 244 eb obtained in the reaction (1) is further chlorinated occurs 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, 1,2-Tetrafluoropropane (HCFC-224ba), 1,1,1-trichloro-2,3,3,3-tetrafluoropropane (HCFC-224eb), 1,1,1,2-tetrachloro-2 , 3,3,3-Tetrafluoropropane (CFC-214bb) and other perchlorinated substances may be by-produced. The reaction by-produced by these perchlorinated substances is shown by the following reaction formula.

The 254 eb chlorination reaction in the first embodiment is preferably carried out under conditions that suppress the side reactions associated with such reaction (1) in order to increase the selectivity of 244 bb and / or 244 eb. Of the above perchlorinated bodies, 234bab, 234ea, 224ba and 224eb can be further dehydrochlorinated to produce 1214ya or 1224yd, and may be produced to some extent as by-products. However, since the usefulness of 214bb is small, it is preferable that the amount produced is small. Therefore, it is particularly preferable that the chlorination reaction of 254 eb in the first embodiment is carried out under the condition that the amount of 214 bb produced is small.

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

In the first embodiment, the ratio of 254 eb and chlorine used, for example, the ratio of 254 eb and chlorine supplied to the reactor is a viewpoint of activating the reaction, and a viewpoint of suppressing the production of by-products, particularly 214 bb. From the viewpoint of increasing the selectivity of 244 bb and / or 244 eb and from the viewpoint of the yield of 244 bb and / or 244 eb from 254 eb, 0.01 to 3.00 mol of chlorine (Cl ₂ ) is preferable for 1 mol of 254 eb. , 0.10 to 2.00 mol, more preferably 0.20 to 1.60 mol, and most preferably 0.50 to 1.50 mol.

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 it can be efficiently produced. In order to improve productivity, it is preferable to carry out the reaction under pressurized conditions. As used herein, pressure refers to gauge pressure unless otherwise stated.

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

Examples of the light source capable of efficiently irradiating the raw material with light having a wavelength of 200 to 750 nm in the chlorination reaction include fluorescent lamps, LED lights, incandescent lamps, high-pressure mercury lamps, and halogen lamps. A light source that generates a large amount of heat is not preferable because it is difficult to keep the internal temperature of the reactor low. If the internal temperature is high, the internal pressure rises, and it is necessary to increase the withstand voltage of the reactor, which is disadvantageous in terms of cost. In addition, if the internal temperature is high, side reactions are likely to occur. Fluorescent lamps and LED lights are preferable as the light source that generates less heat.

When the chlorination reaction is carried out in a liquid phase, the method of irradiating the raw material with light is to uniformly irradiate the entire reaction liquid containing the raw material, the solvent used as necessary, and the product throughout the reaction time. The method is not particularly limited.

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

In the chlorination reaction, 254 eb and chlorine may be separately supplied to the reactor or may be supplied in a premixed state. When a solvent is used, the solvent is capable of dissolving the raw material components (254 eb and chlorine), is inert to the raw material components, and is the target product (244 bb and / or 244 eb) by distillation or the like. ) Can be easily separated from the solvent, without particular limitation.

As the solvent, specifically, carbon tetrachloride, CFC-113, CF ₃ (CF ₂ ) _n CF ₃ (where n in the formula represents an integer of 3 to 6) has 5 to 5 carbon atoms. 8 can be mentioned as a linear perfluoroalkyl compound and a perhalo compound such as hexachloroacetone. Further, the target product 244bb and / or 244eb may be used as a solvent, and by-produced 234bb, 234ea, 224ba, 224eb and 214eb may be used as the 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 target product, and 244bb and / or 244eb, which does not require separation.

The amount of the solvent used for the chlorination reaction is not particularly limited as long as it can dissolve the generated 244 bb and / or 244 eb, but specifically, it is preferably 1 to 4000 mass% with respect to the raw material component (total amount of 254 eb 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 inactive with respect to the components contained in the reaction solution and is not easily corroded by these components. Examples of the material of the reactor include iron, nickel, alloys containing these as main components, glass, resin and the like. From the viewpoint of pressure resistance and corrosion resistance, a reaction vessel 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 method, a batch method and a continuous method. The reaction time can be appropriately adjusted by a general method according to each method. The raw material may be supplied to the reactor by 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 by diluting it with an inert gas such as nitrogen, if necessary.

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

In the case of the continuous system, the raw material is continuously supplied during the reaction, for example, from the lower part of the reactor charged with the solvent. In the case of the continuous type, the product after the reaction is completed is continuously taken out from the upper part of the reactor by, for example, overflow.

In the chlorination reaction, it is preferable to stir using a normal method, an apparatus, or the like in any of the semi-continuous method, the batch method, and the continuous method.

When the chlorination reaction is carried out in the gas phase, the difference from the case where the chlorination reaction is carried out in the liquid phase is that no solvent is used, and the temperature and / or pressure are the conditions of the gas phase. Examples of the conditions for performing the chlorination reaction in the gas phase include conditions of a pressure of 0.00 to 1.00 MPa and a temperature of 0 to 100 ° C.

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

As a method for separating the target product 244bb and / or 244eb from the obtained product, for example, a method of removing chlorine by washing with an alkali and then removing the solvent and by-products by distillation is usually used. Separation method can be mentioned. Further, 244 bb and / or 244 eb can be purified by distillation, and 244 bb or 244 eb with a desired purity or 244 bb and 244 eb with a desired purity can be obtained by repeating the distillation.

[Manufacturing method of 1234yf]
In the method for producing 1234yf of the present invention (“second embodiment”), 244bb and / or 244eb was obtained by the method of the first embodiment, and the obtained 244bb and / or 244eb was used as a base and / or the presence of a catalyst. It is a method of reacting with dehydrochlorination below. The reaction of dehydrochlorinating 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 reaction (3) is a simple substance of 244bb, a simple substance of 244eb, or a mixture of either 244bb and 244eb in a mixed ratio.

Here, the raw material used to carry out the reaction (3) (hereinafter, also referred to as “raw material of the reaction (3)”) is a simple substance of 244bb, a simple substance of 244eb, or a mixture of 244bb and 244eb in a mixed ratio. In addition, those containing no impurities are conceptually preferable. However, from the economical point of view, the raw material of the reaction (3) may contain impurities such as a perchlorinated body produced as a by-product of 244 bb and / or 244 eb in the first embodiment.

Of the perchlorinated bodies, 234 bb, 234 ea, 224 ba and 224 eb are dehydrochlorinated as shown in the formula (4) or the formula (5) under the condition that 244 bb and / or 244 eb undergo a dehydrochlorination reaction by the reaction (3). To generate 1224yd or 1214ya. Specifically, 234 bb and / or 234 ea to 1224 yd are generated, and 224 ba and / or 224 eb to 1214 ya are generated, respectively. Also, 214bb does not inhibit the dehydrochlorination reaction of 244bb and / or 244eb.

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

The raw material of the reaction (3) may contain at least one compound selected from 234 bb, 234 ea, 224 ba and 224 eb with 244 bb and / or 244 eb as a main component. The raw material for reaction (3) may further contain 214bb. In this case, the ratio of the total amount of the impurities 234bb, 234ea, 224ba, 224eb and 214bb is more than 0 mol% to 15 mol with respect to the total amount of the 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 is 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 by, for example, the method described in Japanese Patent No. 5482665 (hereinafter referred to as method (A)). The reaction (3) can be carried out in the gas phase or the liquid phase in the presence of a base (hereinafter, method (B)).

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

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

The method (A) can be carried out by either a batch method or a continuous distribution method, but the continuous distribution method is preferable from the viewpoint of manufacturing efficiency. The reaction time can be appropriately adjusted by a general method according to each mode. Further, in the method (A), it is preferable to add a stirring operation by using a normal 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 lining with ordinary materials such as stainless steel, nickel alloy Hastelloy (registered trademark), Inconel (registered trademark), Monel (registered trademark) and fluoropolymer. Materials such as metal and glass that have been made can be mentioned.

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

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. The alkali metal oxide is preferably sodium oxide, and the alkaline earth metal oxide is preferably calcium oxide. Further, the metal oxide may be an oxide of one kind of metal or a composite oxide of two or more kinds of metals.

Examples of the metal carbonate include alkaline earth metal carbonate and alkali metal carbonate. Alkaline earth metal carbonates include carbonates of beryllium, magnesium, calcium, strontium, barium or radium. Alkali metal carbonates include carbonates of lithium, sodium, potassium, rubidium, cesium or francium.

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

The ratio of base to 244 bb and / or 244 eb is 0.2-3.0 mol per mol of 244 bb and / or 244 eb from the viewpoint of improving the conversion of 244 bb and / or 244 eb and the selectivity of 1234 yf. It is preferably 0.5 to 2.5 mol, more preferably.

Method (B) is carried out in the gas phase or the liquid phase. When the method (B) is carried out in a gas phase, the raw material is used as a gas phase and is brought into contact with a solid-phase base or a base solution containing a base and a solvent. When the method (B) is carried out in the liquid phase, the 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.

The method (B) is preferably carried out in a 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 the solvent for dissolving the base because it has high solubility in the base and is inactive against the dehydrochlorination reaction. That is, in the method (B), the base is preferably used as an aqueous solution of the base. As the aqueous solution of the base, an aqueous solution of an alkali metal hydroxide is preferable, and an aqueous solution of sodium hydroxide or an aqueous solution of potassium hydroxide is more preferable.

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, more preferably 20 to 50% by mass. When the amount of the base is equal to or more than the above lower limit, a sufficient reaction rate can be easily obtained, and the target product can be easily separated by the two-layer separation. If it is not more than the above upper limit, the base is easily sufficiently dissolved and the metal salt is less likely to precipitate, which is likely to be advantageous in an industrial process.

In the method (B), for example, a solution in which a base is dissolved in a solvent, 244 bb and / or 244 eb, and other compounds involved in the reaction used as needed are supplied to the reactor to carry out the reaction. The resulting composition containing 1234yf is recovered from the reactor, but if necessary, cooled via a cooler. Further, it is preferable to recover the product after removing the water through a dehydration tower as needed.

As the reactor, a known reactor used for the dehydrochlorination reaction in the liquid phase reaction is preferable. Examples of the material of the reactor include iron, nickel, alloys containing these as main components, glass and the like. If necessary, the reactor may be subjected to lining treatment such as resin lining and glass lining. 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 where 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 inside 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 rate of 244 bb and / or 244 eb and the selectivity of 1234 yf are improved, and by-products are easily suppressed. In 244bb, the reaction temperature is preferably 60 to 120 ° C, more preferably 80 to 110 ° C. At 244 eb, 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, still more preferably 0.15 to 2.00 MPa. The pressure in the reactor is preferably greater than or equal to the vapor pressure of 244 bb and / or 244 eb at the reaction temperature.

The method (B) can be executed by any of a semi-continuous method, a batch method, and a continuous method. The reaction time can be appropriately adjusted by a general method according to each method. The reaction time is preferably 1 to 50 hours for the batch type and 1 to 3000 seconds for the continuous type because it is easy to control the conversion rate of the 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 it does not affect the reaction. A water-soluble organic solvent such as tetraglyme may be used as long as it does not affect the reaction. It is preferable to use a phase transfer catalyst in order to increase the reaction rate.

Examples of the interphase transfer catalyst include a quaternary ammonium salt, a quaternary phosphonium salt, a quaternary arsonium salt, a sulfonium salt, a crown ether and the like, and a quaternary ammonium salt, a quaternary phosphonium salt and a quaternary arsonium. Salts and sulfonium salts are preferable, and quaternary ammonium salts are more preferable.

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). It is preferable to have.

As the quaternary arsonium salt, triphenylmethylarsonium chloride is preferable. As the sulfonium salt, dodecylmethylethyl sulfonium chloride is preferable.

Examples of the crown ether include 18-crown-6, dibenzo-18-crown-6, dicyclohexyl-18-crown-6 and the like.

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

The material of the reaction process, the reactor, and the reactor when the phase transfer catalyst is used may be the same as when the phase transfer catalyst is not used. Further, the 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 the reactor with compounds involved in the reaction, such as, for example, 244 bb and / or 244 eb, a base, a solvent as needed, and a phase transfer catalyst as needed, so that they are uniform. It can be advanced by stirring to the desired temperature and pressure conditions.

When, for example, an aqueous solution of an alkali metal hydroxide 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, the method (B) is carried out by compatibilizing the aqueous phase containing a base and the organic phase using, for example, a water-soluble organic solvent such as tetraglyme instead of the phase transfer catalyst. Can be done. When a water-soluble organic solvent is used, it is preferable to sufficiently stir in order to make the compounds involved in the reaction in the reaction system uniform.

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

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

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

According to the production method of the present invention, 244 bb and / or 244 eb can be produced from industrially available 254 eb by an industrially feasible method. Further, using 244 bb and / or 244 eb as a raw material, 1234 yf, which is useful as a refrigerant having a low global warming potential, can be produced at an industrially feasible and economically advantageous method with a high conversion rate and selectivity. ..

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. Examples 1 to 6 are examples in the production of 244bb and / or 244eb, and Examples 7 to 9 are examples in the production of 1234yf.

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

[Manufacturing example of 254 eb]
Hydrogen was reacted with 1214ya using a U-shaped reaction tube having a catalyst layer filled with a catalyst-supporting carrier and a reaction device equipped with a salt bath in which the reaction tube was immersed. As the catalyst-supported carrier, a palladium-catalyzed 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. The packing density of the catalyst-supporting carrier in the catalyst layer was 0.73 g / cm ³ .

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

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

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

First, a stainless steel autoclave (internal volume 6.9 liters) equipped with a quartz tube and a jacket that transmit light from a light source was cooled to 20 ° C. After putting 2336 g of carbon tetrachloride (CCl ₄ ) and 103 g of 254 eb into this autoclave (hereinafter referred to as a reactor), an LED lamp (manufactured by 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 irradiating visible light from 40 W; wavelength of emitted light from 400 to 750 nm). As the reaction progressed, heat of reaction was generated, and the temperature inside the reactor rose to 23.8 ° C. The above flow rate chlorine gas was introduced for 2 minutes, that is, 0.10 mol of chlorine was introduced with respect to 1 mol of 254 eb, and light irradiation was continued until the temperature in the reactor became constant at 20 ° C. The pressure in the reactor was 0.045 MPa before chlorine supply and 0.045 MPa after chlorine supply, that is, the reaction pressure.

After completion of the reaction, the obtained reaction solution was mixed with a 20% by mass aqueous solution of potassium hydrogen carbonate to neutralize, 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 used in Example 1 was kept at 20 ° C., and 2336 g of carbon tetrachloride (CCl ₄ ) as a solvent was put into the reactor, and 103 g of 254 eb was put into the reactor. After that, chlorine gas was supplied into the reactor at a flow rate of 3.2 g / min while irradiating visible light from an LED lamp (manufactured by Mitsubishi Electric Corporation, LHT42N-GE39, output 40 W). As the reaction progressed, heat of reaction was generated, and the temperature inside the reactor (reaction temperature) rose to 22.6 ° C. The above flow rate chlorine gas was introduced for 10 minutes, that is, chlorine at a ratio of 0.50 mol to 1 mol of 254 eb was introduced, and light irradiation was continued until the temperature in the reactor became constant at 20 ° C. The pressure in the reactor was 0.045 MPa before chlorine supply and 0.085 MPa after chlorine supply, that is, the reaction pressure.

After completion of the reaction, the obtained reaction solution was mixed with a 20% by mass aqueous solution of potassium hydrogen carbonate to neutralize, 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 used in Example 1 was kept at 20 ° C., and 2336 g of carbon tetrachloride (CCl ₄ ) and 103 g of 254 eb were put therein, and then an LED lamp (manufactured by Mitsubishi Electric Co., Ltd., LHT42N-G-E39, output) was added. Chlorine gas was introduced into the reactor at a flow rate of 3.2 g / min while irradiating with visible light from 40 W). As the reaction progressed, heat of reaction was generated, and the temperature inside the reactor rose to 23.8 ° C. The above flow rate chlorine gas was introduced for 20 minutes, that is, chlorine at a ratio of 1.00 mol to 1 mol of 254 eb was introduced, and light irradiation was continued until the temperature in the reactor became constant at 20 ° C. The pressure in the reactor was 0.045 MPa before chlorine supply and 0.125 MPa after chlorine supply, that is, the reaction pressure.

After completion of the reaction, the obtained reaction solution was mixed with a 20% by mass aqueous solution of potassium hydrogen carbonate to neutralize, 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 chlorine by washing the reaction composition 3 with an alkali, the solvent and by-products were removed by distillation to obtain 244 bb having a purity of 99.9% and 244 eb having a purity of 99.9%.

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

After completion of the reaction, the obtained reaction solution was mixed with a 20% by mass aqueous solution of potassium hydrogen carbonate to neutralize, 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 used in Example 1 was kept at 20 ° C., and 2336 g of carbon tetrachloride (CCl ₄ ) and 103 g of 254 eb were put therein, and then an LED lamp (manufactured by Mitsubishi Electric Co., Ltd., LHT42N-G-E39, output) was added. Chlorine gas was introduced into the reactor at a flow rate of 3.2 g / min while irradiating with visible light from 40 W). As the reaction progressed, heat of reaction was generated, and the temperature inside the reactor rose to 23.8 ° C. The above flow rate chlorine gas was introduced for 40 minutes, that is, chlorine at a ratio of 2.00 mol to 1 mol of 254 eb was introduced, and light irradiation was continued until the temperature in the reactor became constant at 20 ° C. The pressure in the reactor was 0.045 MPa before chlorine supply and 0.198 MPa after chlorine supply, that is, the reaction pressure.

After completion of the reaction, the obtained reaction solution was mixed with a 20% by mass aqueous solution of potassium hydrogen carbonate to neutralize, 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 used in Example 1 was kept at 50 ° C., and 2430 g of carbon tetrachloride (CCl ₄ ) and 103 g of 254 eb were put therein, and then an LED lamp (manufactured by Mitsubishi Electric Co., Ltd., LHT42N-G-E39, output) was added. Chlorine gas was introduced into the reactor at a flow rate of 3.2 g / min while irradiating with visible light from 40 W). As the reaction progressed, heat of reaction was generated, and the temperature inside the reactor rose to 52.8 ° C. The above flow rate chlorine gas was introduced for 20 minutes, that is, chlorine at a ratio of 1.00 mol to 1 mol of 254 eb was introduced, and light irradiation was continued until the temperature in the reactor became constant at 50 ° C. The pressure in the reactor was 0.075 MPa before chlorine supply and 0.165 MPa after chlorine supply, that is, the reaction pressure.

After completion of the reaction, the obtained reaction solution was mixed with a 20% by mass aqueous solution of potassium hydrogen carbonate to neutralize, 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 obtained reaction compositions 1 to 6 are shown in Table 1.
In Table 1, the conversion rate of 254 eb is the ratio of the amount of 254 eb consumed in the reaction to the amount of 254 eb supplied to the reactor, and is a molar conversion value (unit: mol%). The selectivity of each compound is the ratio of each compound to the total amount of the reaction composition, which is a molar conversion 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 a high selectivity.

[Example 7]
A gas phase reaction vessel made of SUS316 having a radius of 1/2 inch was filled with activated carbon (8.50 g) as a catalyst. A preheater was attached to the reaction vessel to keep the temperature at 450 ° C. The 244 bb obtained in Example 3 above was supplied to this gas phase reactor 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.

The 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 become 1234yf. .. The reaction composition containing 1234yf was recovered from the outlet of the gas phase reactor. As a result of GC analysis of the recovered reaction composition, the conversion 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 installed in a constant temperature bath and kept at 80 ° C. To this reactor, 61 g of a 48 mass% KOH aqueous solution, 40 g of the 244 bb 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 performed. rice field. After rotating the stirring blade at 400 rpm and carrying out the reaction for 3 hours, the reactor was taken out from the constant temperature bath and cooled to 0 ° C. with ice water to stop the reaction, and the reaction composition was recovered. As a result of GC analysis of the recovered reaction composition, the conversion 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 installed in a constant temperature bath and kept at 60 ° C. To this reactor, 60 g of a 40 mass% KOH aqueous solution, 32 g of the 244 eb 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 performed. rice field. After rotating the stirring blade at 400 rpm and carrying out the reaction for 30 minutes, the reactor was taken out from the constant temperature bath and cooled to 0 ° C. with ice water to stop the reaction, and the reaction composition was recovered. As a result of GC analysis of the recovered reaction composition, the conversion rate of 244eb was 99%, the yield of 1234yf was 99%, and the selectivity was 100%.

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

Claims (7)

A group consisting of carbon tetrachloride, 2-chloro-1,1,1,2-tetrafluoropropane and 3-chloro-1,1,1,2-tetrafluoropropane under irradiation with light having a wavelength of 200 to 750 nm. In the liquid phase in the presence of a solvent containing at least one selected from, 1,1,1,2-tetrafluoropropane and chlorine are reacted with 2-chloro-1,1,1,2-tetrafluoropropane and / Or obtain 3-chloro-1,1,1,2-tetrafluoropropane, 2-chloro-1,1,1,2-tetrafluoropropane and / or 3-chloro-1,1,1,2- Method for producing tetrafluoropropane. The production 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 production method according to claim 1 or 2, wherein the reaction of 1,1,1,2-tetrafluoropropane and chlorine is carried out at a temperature of 0 to 100 ° C. The production method according to any one of claims 1 to 3, wherein the reaction between 1,1,1,2-tetrafluoropropane and chlorine is carried out at a gauge pressure of 0.00 to 1.00 MPa. .. The production method according to any one of claims 1 to 4 , wherein the reaction of 1,1,1,2-tetrafluoropropane and chlorine is carried out under irradiation of a fluorescent lamp or an LED lamp. The production method according to any one of claims 1 to 5 , wherein the solvent is used in a ratio of 1 to 4000% by mass with respect to the total amount of 1,1,1,2-tetrafluoropropane and chlorine. .. 2-Chloro-1,1,1,2-tetrafluoropropane and / or 3-chloro-1,1,1,2-tetrafluoropropane can be obtained by the production method according to any one of claims 1 to 6 . Obtained, the obtained 2-chloro-1,1,1,2-tetrafluoropropane and / or 3-chloro-1,1,1,2-tetrafluoropropane was removed in the presence of a base and / or a catalyst. A method for producing 2,3,3,3-tetrafluoropropene to be reacted with hydrogen chloride.