JPH1171326A - Production of unsaturated glycol diester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject compound by feeding a carboxylic acid and conjugated diene into a reactor filled with a rhodium-based catalyst at the beginning of reaction, then supplying a molecular oxygen thereinto for reaction, and thus suppressing a reduction of activity of the catalyst. SOLUTION: This objective compound is obtained by introducing an inert gas (e.g. nitrogen gas) into a reactor filled with a rhodium-based catalyst, increasing the pressure therein if necessary, feeding a carboxylic acid (pref. acetic acid) and conjugated diene (e.g. butadiene) in this order, feeding a molecular oxygen, and reacting them with each other under normal pressure to 100 kgf/cm<2> at pref. 40 to 120 deg.C. The rhodium-based catalyst, includes at least a rhodium (e.g. rhodium chloride) and pref. furthermore tellurium [e.g. tellurium chloride (II)] as an active ingredient, and this catalyst is usable in such a form as to be carried by a silica material, etc., or in the form of its active component metal powder by itself. Preferably, there is used 2 to 40 mol of carboxylic acid and 0.5 to 10 mol of oxygen based on 1 mol of conjugated diene.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing an unsaturated glycol diester. Specifically, the present invention
The present invention relates to an improvement in a reaction initiation method in a method for producing a corresponding unsaturated glycol diester by reacting a conjugated diene with a carboxylic acid and molecular oxygen in the presence of a rhodium-based catalyst. Unsaturated glycol diesters such as butenediol diester are raw materials for engineering plastics, elastomers, elastic fibers, and synthetic leathers.
-An important intermediate compound for producing butanediol, tetrahydrofuran, a raw material for high-performance solvents and elastic fibers.

[0002]

2. Description of the Related Art Unsaturated glycol diesters such as 1,4-diacetoxybutene-2 are usually produced by reacting butadiene with acetic acid and oxygen in the presence of a white metal catalyst (JP-A-48-72090). No., JP-A-7
-206766, etc.). In this reaction, usually, an inert gas such as nitrogen is introduced into the reactor, the pressure is increased as necessary, acetic acid is supplied, and then molecular oxygen and butadiene are supplied to start the reaction.

[0003] In particular, a method using a catalyst containing rhodium as an active component is superior in activity and a selectivity to 1,4-diacetoxybutene-2 as compared with a catalyst using palladium as an active component. For example, in JP-A-52-130994, rhodium and tellurium and / or selenium are used as active ingredients, and in JP-A-53-37609, rhodium or rhodium is used as an active ingredient. And Japanese Patent Application Laid-Open No. 53-44502 disclose the use of a catalyst to which molybdenum is further added. Also, JP-A-53-241
In Japanese Patent Publication No. 4 (1994) -104, at least one metal selected from rhodium, palladium and platinum is used in combination with sulfur, and in Japanese Patent Application Laid-Open No. 51-108010, tellurium is used in combination with at least one metal selected from palladium, rhodium and platinum. And / or sulfur in combination, and
-34694 discloses a certain percentage of rhodium,
It is disclosed that platinum, palladium and tellurium are used as active ingredients.

[0004]

However, when rhodium is used as an active ingredient, there is a problem that rhodium elutes into the system under the reaction conditions. Rhodium is a particularly expensive metal, the loss of which is economically burdensome. In addition, when rhodium is eluted in industrial use, stable operating conditions cannot be obtained due to a decrease in reaction activity and selectivity. Since the elution of rhodium is extremely remarkable at the beginning of the reaction, particularly at the start of the reaction,
Establishing a reaction initiation method that suppresses the elution of rhodium is an industrially important issue. Accordingly, an object of the present invention is to provide a reaction initiation method capable of suppressing the elution of rhodium.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that carboxylic acid and carboxylic acid are supplied before supplying molecular oxygen into a reactor filled with a catalyst at the start of the reaction. By supplying a conjugated diene and then supplying molecular oxygen, it has been found that elution of rhodium is suppressed, and a decrease in activity is suppressed, and high activity is obtained, and the present invention has been completed.

That is, the gist of the present invention is to provide a method for producing a corresponding unsaturated glycol diester by reacting a conjugated diene with a carboxylic acid and molecular oxygen in the presence of a rhodium-based catalyst. A method for producing an unsaturated glycol diester, which comprises supplying molecular oxygen after supplying a carboxylic acid and a conjugated diene to a reactor. Hereinafter, the present invention will be described in detail.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION

(1) Catalyst for Conjugation of Conjugated Diene The rhodium-based catalyst used in the present invention contains at least rhodium as an active ingredient, and is selected from tellurium, antimony, selenium, sulfur, tin, gallium, and copper in addition to rhodium. It preferably contains one or more elements,
Among them, it is particularly preferable to contain tellurium. Further, it may contain gold, palladium, or platinum. The form may be one supported on a carrier such as silica, alumina or activated carbon, or the metal powder of the active ingredient itself. In the case of a catalyst supported on a support, the amount of the active component in the supported catalyst is usually 0.1 to 20% by weight of rhodium based on the total weight of the catalyst including the support, and the other components are 0.01% by weight in total. ~ 30
% By weight.

The raw material of the active component of the catalyst used in the present invention is not particularly limited, and nitric acid, sulfuric acid,
Inorganic acid salts such as hydrochloric acid, organic acid salts such as acetic acid, hydroxides, oxides, or complex salts, and further, carbonyl complexes and organometallic compounds represented by acetylacetonate salts can also be used. It is. For example, in the case of rhodium, rhodium chloride, rhodium nitrate, rhodium sulfate, rhodium acetate, rhodium hydroxide, rhodium oxide, sodium hexachlororhodium, hexachlororhodium ammonium,
Chloropentaamminerhodium, chlorohexamminerhodium, hexacyanorhodium potassium, trichlorotripyridinerhodium, chlorocyclooctadienylrhodium, tetrarhodium dodecacarbonyl, dicarbonylacetylacetonatotrodium and the like, and furthermore, metal rhodium may be used. In the case of an active ingredient other than rhodium, for example, tellurium (II) chloride in the case of tellurium,
(IV), tellurium oxide (IV), (VI), telluric acid (H ₆ T
eO ₆ ), inorganic tellurium compounds such as sodium hydrogen telluride (NaHTe), and diphenyl ditelluride (Ph
And organic tellurium compounds such as Te) ₂ , and further, metallic tellurium may be used.

The method for producing the catalyst is not particularly limited. For example, in the case of a metal powder, a method of reducing a metal salt of an active ingredient dissolved in a solution using a reducing agent, a method of reducing a solution containing an active ingredient, An arbitrary method such as a method of drying and, if necessary, a baking treatment followed by reduction is used. Further, after the reduction, if necessary, a baking treatment may be performed and the reduction may be performed again, or these may be repeated.

In the case of producing a catalyst supported on a carrier,
Usually, the carrier is loaded with the active ingredient and then subjected to a reduction treatment before use. The method for supporting the active ingredient is not particularly limited. The method may be such that the compound of the active ingredient is dissolved in a solvent capable of dissolving and then impregnated into a carrier and supported, or the compound or metal of the active ingredient is directly vaporized by vaporization. Any method such as a method of vapor deposition can be used. All of the active ingredients may be loaded at once, or may be loaded several times. If necessary, a method of supporting each component or a method of separately supporting only a specific component can be adopted.

When the compound is supported as a solution, for example, when the compound is supported by an impregnation method, an immersion method, a precipitation method, a pore-filling method, etc., the solvent is removed by drying after these operations. The drying method is not particularly limited, and for example, a method of heating while flowing a gas, a method of heating without flowing a gas, or drying under reduced pressure can be used. The catalyst supporting the active component may be subjected to a calcination treatment before the reduction, or may be repeated if necessary. The reduction of the active component used in the present invention is not particularly limited, and may be any of gas-phase reduction with hydrogen gas or methanol gas, or liquid-phase reduction represented by hydrazine or formalin, and may be performed by drying if necessary. May be reduced before.

(2) Production of unsaturated glycol diesters A conjugated diene, for example, butadiene, which is a reaction raw material used in producing an unsaturated glycol diester by using the above-mentioned catalyst, is not necessarily required to be pure, and is not limited to nitrogen. An inert gas such as a gas, a saturated hydrocarbon such as methane, ethane, and butane, or an unsaturated hydrocarbon such as butene may be used. As the conjugated diene, an alkyl-substituted butadiene such as isoprene, 2,3-dimethylbutadiene and piperidine, and a cyclic diene such as cyclopentadiene can be used.

Next, the carboxylic acid which is another reaction raw material is a lower monocarboxylic acid such as acetic acid, propionic acid,
There are butyric acid and the like, and acetic acid is more preferable, particularly in view of reactivity and price. The carboxylic acid may serve as a solvent while being a reaction raw material. If necessary, an organic solvent inert to the reaction, for example, a saturated hydrocarbon or an ester may be present. However, 50% by weight or more of the reaction solvent is preferably a carboxylic acid as a raw material. The amount of the carboxylic acid to be used is preferably in the range of not less than stoichiometric amount and not more than 60 mol, more preferably not more than 2 to 40 mol, per 1 mol of the conjugated diene.

The molecular oxygen used in the method of the present invention does not need to be pure oxygen, but may be oxygen diluted with an inert gas such as nitrogen, for example, air. The amount of oxygen used is not particularly limited as long as it is at least a stoichiometric amount, but is preferably in the range of 0.5 to 100 mol, more preferably 0.5 to 10 mol, per mol of the conjugated diene. Range. Further, for safety reasons, a range that does not result in an explosive composition industrially is preferable.

The reaction of the present invention for producing the corresponding carboxylic acid diester of unsaturated glycol by reacting a conjugated diene with a carboxylic acid and molecular oxygen can be carried out by any of a batch method and a continuous method. As the reaction system, any system such as a fixed bed system, a fluidized bed system, and a suspension tank system can be adopted, but the fixed bed system is more preferable industrially. The amount of the catalyst can be arbitrarily used depending on the reaction system or the like. The reaction is usually carried out at a temperature of 20 ° C. or higher, but a preferable range of the reaction temperature is 40 to 120 ° C. in consideration of the reaction rate and the generation of by-products. The reaction pressure may be normal pressure or pressurization. To increase the reaction rate, pressurization is preferable, but the cost of the reaction equipment is high, and considering them, the preferable range is normal pressure to 100 kgf / cm ² .

(3) Reaction Initiation Method The reaction initiation method in the present invention, for example, when 1,4-diacetoxybutene-2 is produced from butadiene, acetic acid and molecular oxygen, is performed in the following order. Although not described in the description, gas and / or liquid may be circulated if necessary. a. An inert gas such as nitrogen gas is introduced into a reactor filled with a catalyst containing rhodium, and the pressure is increased if necessary. b. Feed acetic acid to the reactor. c. Feed butadiene to the reactor. The supply may be started before or at the same time as the supply of acetic acid, if necessary, but usually, butadiene is supplied after the supply of acetic acid. The supply method may be either gaseous or liquid. If necessary, a solution prepared by dissolving butadiene in acetic acid may be supplied. d. Oxygen is supplied to the reactor to start the reaction. The supply may be started after the butadiene or acetic acid in which the butadiene is dissolved reaches all of the catalyst layers. The supply method may be a method of directly supplying to the reactor or a method of supplying the mixture after mixing with butadiene in advance. However, usually, the mixture is supplied to the reactor after premixing with acetic acid or acetic acid in which butadiene is dissolved. When using a gas in which the supplied oxygen is diluted, the supply may be started at a predetermined oxygen concentration, and if necessary, the supply may be started at an oxygen concentration lower than the predetermined concentration, and the oxygen concentration may be gradually increased. May be supplied. The temperature rise to the predetermined reaction temperature may be performed at any of the above-described steps, and may be performed after all of the above-described steps, if necessary. However, it is usually performed after acetic acid is supplied.

The reason why the reaction initiation method of the present invention suppresses the elution of rhodium and exhibits high activity has not been elucidated so far, but is presumed to be as follows. When oxygen reaches the active component in the absence of the conjugated diene, the oxygen is considered to oxidize and dissolve rhodium as the active component. Therefore, it is important that the conjugated diene reaches the active ingredient before the oxygen reaches, and that the conjugated diene is adsorbed on the active ingredient.
If oxygen subsequently arrives, it is considered that oxygen is mainly consumed as a reaction substrate, thereby suppressing the elution of rhodium and exhibiting high activity.

[0018]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the scope of the invention. In the reaction result, the activity is defined as 3,4-diacetoxybutene-1,
3-hydroxy-4-acetoxybutene-1, 1-acetoxycyclotonaldehyde, 1,4-diacetoxybutene-2 (14 DABE), 1-hydroxy-4-acetoxybutene-2, 1,4-dihydroxybutene-2, It indicates how many mmol of diacetoxyoctatriene and triacetoxybutene were produced per 1 kg of catalyst per hour.

Example 1 0.6205 g of tellurium metal (manufactured by NE Chemcat) was placed in a 50-ml volumetric flask, and 18 g of a 35% by weight nitric acid aqueous solution was added and dissolved. 32.40 g of a 5.15% by weight rhodium nitrate aqueous solution (manufactured by NE Chemcat) was added thereto, and a 35% by weight aqueous solution of nitric acid was further added.
Diluted to 0 ml. A spherical silica carrier (CariACT-15, manufactured by Fuji Silysia Chemical Ltd .: trade name, 1.7 to 3.36 mm, hereinafter referred to as CARiACT-15) was added to this solution.
After adding 23.14 g and immersing at room temperature for 1 hour,
This was filtered to remove the solution, and the solution was further removed by a centrifugal separator to obtain 50.87 g. This catalyst was used with an inner diameter of 2.
It is placed in a Pyrex glass tube of 5 cm (effective area 4.9 cm ² ) and kept at 150 ° C. for 3 hours and further heated to 500 ° C. for 2 hours while flowing air at 1.45 Nl / min. Cooled down. Then 0.72Nl
/ Minute of hydrogen and heated to 400 ° C in 1 hour,
After holding for a time, the mixture was cooled in a nitrogen stream to obtain 24.18 g of an activated catalyst. The catalyst is rhodium 3.14.
% By weight and 1.17% by weight tellurium. Next, 4 g of this catalyst was immersed in an inner diameter of 12 mm (effective area 1.00
5 cm ² ) into a stainless steel reaction tube, and after purging with nitrogen, the pressure was increased to 30 kgf / cm ^2, and the pressure was further increased to 100 Nl.
The supply of acetic acid was started at a flow rate of 150 ml / hour while flowing nitrogen at a flow rate of 150 ml / hour. After heating the reactor to 80 ° C. in this state, 0.156 mol / l of 1,3-butadiene was added.
The acetic acid line was merged with the acetic acid line at the time, and the supply to the reactor in a form dissolved in acetic acid was started. Thirty minutes after the start of the supply of butadiene, the flow of nitrogen was stopped, and supply of nitrogen containing 6% by volume of oxygen was started at a flow rate of 100 Nl / hour. Sampling of the reaction solution was started after the supply of nitrogen containing 6% by volume of oxygen was started, and a fraction up to one hour later was obtained, and the Rh concentration in the reaction solution was measured by ICP emission analysis. Further, a reaction liquid fraction from 4 hours to 5 hours later was obtained,
The product was quantified by gas chromatography. Table 1 shows the results.

Comparative Example 1 A reaction was carried out in the same manner as in Example 1, except that 1,3-butadiene and nitrogen containing 6% by volume of oxygen were simultaneously supplied. Sampling of the reaction solution was started after the supply of butadiene and nitrogen containing 6% by volume of oxygen was started, and a fraction up to one hour later was obtained, and the Rh concentration in the reaction solution was measured by ICP emission analysis. . A reaction liquid fraction was further obtained after 4 hours to 5 hours, and the product was quantified by gas chromatography. Table 1 shows the results.

Example 2 1.2377 g of tellurium metal (manufactured by NE Chemcat) was placed in a 100 ml volumetric flask, and then 36 g of a 35% by weight nitric acid aqueous solution was added and dissolved. 15.35% by weight
An aqueous rhodium chloride solution (aqueous solution of rhodium chloride manufactured by NE Chemcat in demineralized water) (21.69 g) was added, and further diluted with demineralized water to 100 ml. A spherical silica carrier (CARiACT-
15) After adding 45.64 g and immersing for 1 hour at room temperature, this was filtered to remove the solution, and the solution was further removed by a centrifugal separator to obtain 96.12 g. This catalyst was used with an inner diameter of 2.5
cm (effective area 4.9 cm ² ) in a Pyrex glass tube, while flowing air at 2.85 Nl / min.
The temperature was raised to 500 ° C. for 3 hours at 50 ° C., further maintained for 2 hours, and then cooled to room temperature. Then 1.43 Nl /
The temperature was raised to 400 ° C. in 1 hour and maintained for 2 hours, and then cooled in a nitrogen stream to obtain 47.68 g of an activated catalyst. The catalyst contained 3.12% by weight rhodium and 1.16% by weight tellurium. next,
An inner diameter of 12 mm (effective area: 1.005 c
m ² ) was filled in a stainless steel reaction tube, and after replacing with nitrogen, the pressure was increased to 60 kgf / cm ² , and the supply of acetic acid was started at a flow rate of 150 ml / hour while flowing nitrogen at a flow rate of 100 Nl / hour. After the temperature of the reactor was raised to 80 ° C. in this state, 1,3-butadiene was combined with the acetic acid line at a rate of 0.156 mol / hour, and supply to the reactor in a form dissolved in acetic acid was started. Thirty minutes after the start of the supply of butadiene, the flow of nitrogen was stopped, and the supply of nitrogen containing 6% by volume of oxygen was started at a flow rate of 100 Nl / hour. Oxygen 6
Sampling of the reaction solution was started after the supply of nitrogen containing volume% was started, and a fraction up to one hour later was obtained, and the Rh concentration in the reaction solution was measured by ICP emission analysis.
A reaction liquid fraction was further obtained after 4 hours to 5 hours, and the product was quantified by gas chromatography. Table 1 shows the results.

Comparative Example 2 A reaction was carried out in the same manner as in Example 2, except that 1,3-butadiene and nitrogen containing 6% by volume of oxygen were simultaneously supplied. Sampling of the reaction solution was started after the supply of butadiene and nitrogen containing 6% by volume of oxygen was started, and a fraction up to one hour later was obtained, and the Rh concentration in the reaction solution was measured by ICP emission analysis. . A reaction liquid fraction was further obtained after 4 hours to 5 hours, and the product was quantified by gas chromatography. Table 1 shows the results.

Example 3 0.622 g of tellurium metal (manufactured by NE Chemcat) was placed in a 50-ml volumetric flask, and 16 g of a 35% by weight nitric acid aqueous solution was added and dissolved. 25.63 g of a 6.53% by weight rhodium chloride aqueous solution (aqueous solution of rhodium chloride manufactured by NE Chemcat in deionized water) and 10.25%
Wt% antimony chloride hydrochloride solution (prepared by dissolving Kishida Chemical Ltd. antimony chloride SbCl ₃ to 5 N hydrochloric acid) 3.8
6 g was added, and further diluted to 50 ml by adding demineralized water. A spherical silica carrier (CA
After adding 34.00 g of RiACT-15) and immersing at room temperature for 1 hour, this was filtered to remove the solution, and the solution was further removed by a centrifugal separator to obtain 73.32 g. The catalyst was placed in a Pyrex glass tube having an inner diameter of 2.5 cm (effective cross-sectional area of 4.9 cm ² ) and heated to 500 ° C. for 3 hours at 150 ° C. while flowing air at a rate of 2.83 Nl / min. After holding for a time, it was cooled to room temperature. Next, switching to hydrogen at 0.71 Nl / min, the temperature was raised to 400 ° C. in 1 hour, and the temperature was maintained for 2 hours, and then cooled in a nitrogen stream to obtain 35.81 g of an activated catalyst. The catalyst contained 3.14% rhodium, 1.17% tellurium, and 0.74% antimony by weight. The reaction was carried out in the same manner as in Example 2 except that this catalyst was used. Sampling of the reaction solution was started after the supply of nitrogen containing 6% by volume of oxygen was started, and a fraction up to 1 hour later was obtained, and the Rh concentration in the reaction solution was measured by ICP emission analysis. Further, a reaction liquid fraction from 4 hours to 5 hours later was obtained,
The product was quantified by gas chromatography. Table 1 shows the results.

[0024]

[Table 1] ^* mmol / kg-cat. h

[0025]

According to the present invention, the elution of rhodium from a catalyst in the acyloxylation reaction of a conjugated diene is suppressed,
A decrease in the activity of the catalyst can be suppressed. In addition, since a decrease in the catalyst activity is suppressed, the catalyst can be used for a long time.

Claims (4)

[Claims] In a method for producing a corresponding unsaturated glycol diester by reacting a conjugated diene with a carboxylic acid and molecular oxygen in the presence of a rhodium-based catalyst, a carboxylic acid and a carboxylic acid are added to the reactor when starting the reaction. A method for producing an unsaturated glycol diester, comprising supplying molecular oxygen after supplying a conjugated diene. 2. The method according to claim 1, wherein the rhodium-based catalyst is a catalyst containing rhodium and tellurium. 3. The method according to claim 1, wherein the conjugated diene is at least one selected from butadiene, isoprene and alkyl-substituted butadiene. 4. The method according to claim 1, wherein the carboxylic acid is acetic acid.