JPH0261296B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an isomerization reaction catalyst comprising an alkali metal supported material. More specifically, the present invention relates to a catalyst for isomerization of olefins comprising an alkali metal supported material that forms an ultra-strongly basic catalyst with excellent catalytic activity and reproducibility of catalyst preparation.

[Conventional technology]

As strong basic catalysts used in the isomerization reaction of olefins, there are known alkali metal-supported materials prepared by supporting an alkali metal on a carrier with a large specific surface area, such as activated alumina. 45-24138). This substance is
Although it has high catalytic activity, it is extremely unstable;
Even if great care is taken during its preparation, storage, handling, etc., it is still not possible to obtain one that exhibits stable catalytic performance.

[Problem that the invention seeks to solve]

Based on such prior art, the present inventors have carried out various studies in search of a strong basic catalyst that is highly active for the isomerization reaction of olefins and exhibits stable performance in terms of reproducibility of catalyst preparation. As a result, it was found that a calcined product of hydrotalcite-related compounds supporting an alkali metal satisfactorily satisfies these requirements.

[Means for Solving the Problems] and [Operation] Therefore, the present invention relates to an isomerization reaction catalyst for olefins comprising an alkali metal supported substance, and this alkali metal supported substance has the general formula [Mg _1-x Rx(OH) ₂ ] ^x+・[CO _3x/2・mH ₂ O] ^x-
[] R: Al, Cr, Fe x: 0<x<0.34 m: 0≦m≦5 An alkali metal is supported on a fired product of a hydrotalcite-related compound.

The hydrotalcite analog compound represented by the above general formula [] is more generally represented by the following general formula [M _1-x R′x(OH) ₂ ] ^x+・[A _x/o・mH ₂ O] ^{x -} [] M: divalent metal R': trivalent metal A: n-valent anion where n is 1 or 2 It is a compound in which metals, trivalent metals, and n-valent anions are specified. In the above general formula [], Zn, Mn,
Ni, etc., as well as n-valent anions such as F ^- , Cl ^- ,
Examples include inorganic anions such as Br ^- , I ^- , CrO ₄ ^-- , HPO ₄ ^-- , NO ₃ ^- , SO ₄ ^--, and organic anions such as oxalate ion and salicylate anion.

In the hydrotalcite analog compound represented by the above general formula [], a basic layer formed by combining octahedrons with Mg as a central metal ion in a network layer form forms a structural matrix, and in this basic layer,
Since Mg is partially substituted by the metal R and is positively charged, the crystal structure is a layered structure with exchangeable CO ₃ anions interposed between the basic layers to keep the charge neutral. Water is also present between the layers.

Specifically, compounds in which aluminum is used as the trivalent metal in the general formula [] are preferably used, and some examples of such compounds are shown below.

[Mg _0.75 Al _0.25 (OH) ₂ ] ・[CO _31/8・0.5～0.625H ₂ O] [Mg _13/9 Al _13/4 (OH) ₂ ]・[CO _313/2・7/13H ₂ O ] [Mg _2/3 Al _1/3 (OH) ₂ ]・[CO _31/6・0.5H ₂ O] In addition, the following are compounds using iron or chromium as trivalent metals. Illustrated.

[Mg _2/3 Fe _1/3 (OH) ₂ ]・[CO _31/6・mH ₂ O] [Mg _2/3 Cr _1/3 (OH) ₂ ]・[CO _31/6・mH ₂ O] The five types of compounds exemplified above can also be represented by the following formula.

Mg ₆ Al ₂ (OH) ₁₆ CO ₃・4〜5H ₂ O Mg _4.5 Al(OH) ₁₃ CO ₃・3.5H ₂ O Mg ₄ Al ₄ (OH) ₁₂ CO ₃・3H ₂ O Mg ₄ Fe(OH) ₁₂ CO ₃・6mH ₂ O Mg ₄ Cr ₂ (OH) ₁₂ CO ₃・6mH ₂ O These hydrotalcite related compounds are generally calcined at about 300 to 700°C, preferably about 400 to 600°C.
℃ for more than 1 hour. This firing treatment is desirably carried out in a stream of nitrogen gas or dry air, preferably nitrogen gas. It is preferable that the obtained baked product has high base strength;
Specifically, when diphenylamine is adsorbed as an indicator, the color of the indicator changes from an acidic color (colorless) to a basic color (pale blue). It is desirable to use a high-quality carrier as a carrier. In this way, the fired product with high base strength is a compound using magnesium as a divalent metal among the hydrotalcite related compounds represented by the above general formula [], especially the hydrotalcite represented by the above general formula []. Obtained by calcining related compounds.

Hydrotalcite analogues or their calcined products generally have a specific surface area of 100 m 2 /g, whereas that of conventionally known basic carriers of alkali metal supporting materials, such as magnesium oxide, is about 20 m ² /g.
It has a specific surface area of m ² /g or more. Therefore, when this fired product supports an alkali metal,
Because the alkali metal is highly dispersed and supported,
A highly active and stable solid strongly basic catalyst is formed. In particular, as described above, when an alkali metal is supported on a strongly basic calcined product carrier, an extremely highly active catalyst can be obtained.

The alkali metal carrier for the fired product carrier can be prepared, for example, by heating a lump of alkali metal to a temperature higher than its melting point and adding it to a powdered, granular or molded carrier while stirring; Alternatively, it may be carried out by a method of vapor depositing an alkali metal onto a carrier under reduced pressure.

The proportion of the alkali metal supported on the carrier is about 1 to 15% by weight, preferably about 3 to 10% by weight, based on the weight of the carrier. If the supported amount is less than this, the desired catalytic activity cannot be obtained; If you use more,
Not only does the dispersion state of the alkali metal deteriorate, but it also becomes flammable to water and its stability as a catalyst decreases. The supported alkali metals include lithium, sodium, potassium,
Examples include rubidium and cesium, but sodium is generally used.

In the thus obtained alkali metal-supported material, no alkali metal peak was observed in X-ray powder diffraction analysis, indicating that the alkali metal was supported on the support in a finely dispersed manner. In addition, even in the case of conventionally known metal oxides such as alumina, the existence of a peak of the supported alkali metal is not observed in X-rays.

This alkali metal supported material exhibits high activity as a solid strong base catalyst for, for example, isomerization reactions of olefins, dehydrogenation reactions, hydrogenation reactions, low polymerization reactions, addition reactions, and various condensation reactions. Among these, it exhibits an excellent catalytic effect on the isomerization reaction of olefins, and is particularly effective in, for example, the isomerization reaction from an alkenyl bridged ring compound to an alkylidene bridged ring compound.

As the olefins subjected to the isomerization reaction,
Straight or branched unsaturated chain aliphatic hydrocarbons such as butene, pentene, methylpentene, dimethylbutene, hexene, heptene, octene, nonene, decene, methylcyclopentene, ethylcyclopentene, methylcyclohexene, ethylcyclohexene, vinylcyclohexene unsaturated alicyclic hydrocarbons such as vinylcyclohexane, alkenyl cyclic hydrocarbons such as allylcyclohexane, alkenyl bridged ring compounds such as alkenylbicycloheptenes, unsaturated amine compounds such as allylamine, butenylamine, pyrroline, etc. , ethyl crotyl ether, 6
-methoxy-1-hexane, 3-methoxy-1-
Examples include unsaturated ether compounds such as butene.

Specifically, for example, the isomerization reaction of the unsaturated chain aliphatic hydrocarbon includes a skeletal isomerization reaction and a double bond transfer reaction. For example, when butene-1 is used, cis-butene-2 and trans-butene-2 are used, and when 4-methyl-pentene-1 is used, cis-4-methylpentene-2, trans-4- Methylpentene-2,2-
Methylpentene-1, 2-methyl-pentene-2
and 3-methylpentene-2, and when octene-1 is used, octene-2, octene-2
3 and octene-4 are obtained as isomerization reaction products, respectively. Through such an isomerization reaction,
When two or more types of reaction products are obtained, it is also possible to selectively produce a specific isomerization reaction product to some extent by appropriately selecting the reaction temperature, reaction time, etc., for example. The internal double bond-containing unsaturated chain aliphatic hydrocarbon obtained by this isomerization reaction is useful as a raw material for producing a secondary alcohol by a hydration reaction or as a raw material for an olefin disproportionation reaction.

In addition, in the isomerization reaction of alkenylbicycloheptene, 5-ethylidene-2-norbornene is produced from 5-vinyl-2-norbornene, and 5-ethylidene-2-norbornene is produced from 5-propenyl-2-norbornene.
-propylidene-2-norbornene is also 5-
From isopropenyl-2-norbornene, 5-isopropylidene-2-norbornene is obtained as a reaction product. These 5-alkylidene-2-norbornenes are important monomers as diene components of EPDM, for example.

In the isomerization reaction of these olefins,
The solid strong base catalyst as the alkali metal supporting material generally contains about 0.001 to 1 g atom of alkali metal per mole of raw material olefin, preferably about 0.01 g atom.
It is used at a rate of ~0.1 g atom.

The isomerization reaction is generally carried out in the absence of a solvent, but it can also be carried out in the presence of a solvent as long as the reaction is not inhibited. Examples of solvents that can be used include pentane, hexane, heptane, octane, dodecane, cyclohexane, benzene, toluene,
Hydrocarbons such as xylene, diethyl ether,
Examples include ethers such as dibutyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran, and tetrahydropyran.

The reaction conditions are about 0 to 0 under normal pressure to increased pressure.
Temperatures of 120 DEG C., preferably about 20 DEG to 100 DEG C. are used, and the operation can be carried out either batchwise, semi-continuously or continuously.

The alkali metal-supported material according to the present invention can be used not only as an isomerization reaction catalyst for olefins, but also as a catalyst for the isomerization reaction of olefins.
It can also be effectively used as a catalyst for dehydrogenation reactions, hydrogenation reactions, low polymerization reactions, addition reactions, and various condensation reactions.

For example, dehydrogenation reactions include reactions to obtain isoprene from 2-methyl-1-butene and 2-methyl-2-butene, and reactions to obtain isoprene from 2,3-dimethyl-1-butene and 2,3-dimethyl-2-butene. 3-
As a catalyst for reactions to dehydrogenate olefins to obtain diene compounds, such as the reaction to obtain dimethyl-1,3-butadiene, the reaction to obtain butadiene from butene-1 and butene-2, and the reaction to obtain piperylene from pentene. can also be used.

In addition, in low polymerization reactions, for example, butadiene or isoprene is reacted as a catalyst to obtain low-order polymers, and in addition reactions, benzenes substituted with alkyl groups, such as toluene, ethylbenzene, xylene, isopropylbenzene, etc. It is also used as a catalyst for the reaction of adding a chain aliphatic unsaturated hydrocarbon having 2 to 5 carbon atoms, or for the reaction of reacting an amino compound such as diethylamine with a conjugated diene such as butadiene to obtain, for example, 2-butenyldiethylamine. be able to.

〔Effect of the invention〕

The alkali metal-supported material of the present invention exhibits extremely high catalytic activity when used as a catalyst in the isomerization reaction of olefins. For example, when it is used in the isomerization reaction of alkenylbicycloheptenes, it exhibits quantitative Generates alkylidene bicycloheptenes. Thus, this alkali metal supported material exhibits high catalytic activity.

In addition, this alkali metal-supported material has a large specific surface area of the calcined hydrotalcite-related compound used as a support, and has excellent alkali metal dispersibility, making it easier to reproduce catalyst preparation than conventional catalysts. They are also excellent in terms of sex.

〔Example〕

Next, the present invention will be explained with reference to examples.

Example 1 Kyowa Kagaku Kyoward #1000mg _4.5 Al ₂ (OH) ₁₃ CO ₃ as a hydrotalcite related compound
3.5H ₂ O is used and 500g of these are
It was baked at ℃ for 3 hours. When the specific surface area of the obtained fired product was measured by the BET single point method using a Countersolve specific surface area measuring device manufactured by Counterchrome Co., Ltd., a value of 174 m ² /g was obtained, which was lower than the value before firing of 121
The value was significantly increased compared to m ³ /g.
Furthermore, when the basic strength of this baked product was measured by an indicator measurement method, 4-chloroaniline with a pKa of 26.5 changed from colorless to pink, indicating high basicity.

Place 100 g of this fired product powder in a flask, heat it to 250°C under a nitrogen gas atmosphere, add 8.7 g of metallic sodium in small amounts over a period of about 20 minutes while stirring well, and continue stirring for about 2 hours. In this way, metallic sodium was supported on the hydrotalcite related compound fired product powder in an amount of 8.0% by weight. When the basic strength of this substance was measured by the indicator extraction method, triphenylmethane with a pKa of 35.0 changed from colorless to yellow, indicating ultra-strong basicity.

2 g of the metal sodium support material obtained in this way was mixed with 250 g of 5-vinyl-2-norbornene.
was added to the flask containing the mixture, and continued stirring at 80°C for 60 minutes. When the reaction solution was analyzed by gas chromatography (PEG20M, 3m), the above 5-
The entire amount of the vinyl compound was changed to 5-ethylidene-2-norbornene, and no other by-products were observed.

Example 2 In Example 1, the same amount of Kyowa Kagaku Kyoward #500Mg ₆ Al ₂ (OH) ₁₆ CO ₃ 4H ₂ O was used as the hydrotalcite related compound,
In addition, the same process was carried out with the amount of metallic sodium changed to 9.8 g (however, the firing temperature was 550° C.) to obtain a material in which metallic sodium was supported in an amount of 9.0% by weight.

When the specific surface area of the hydrotalcite analog compound used after firing was measured by the method of Example 1, a value of 163 m ² /g was obtained. Also, when the base strength of this baked product was measured, the highest base strength was:
26.5 and 27.0 expressed in pKa value using indicator measurement method
It was between. Furthermore, in the obtained metallic sodium-supported material, triphenylmethane with pKa of 35.0 changed from colorless to pink, indicating ultra-strong basicity, as in Example 1.

2 g of the metal sodium support material thus obtained was mixed with 150 g of 5-vinyl-2-norbornene.
When the reaction solution was poured into a flask containing 5-ethylidene-2-norbornene and continued stirring at 80°C for 60 minutes, the entire amount of the reaction solution was changed to -5-ethylidene-2-norbornene, and other by-products were did not acknowledge the existence of

Example 3 In Example 1, 9.2 g of metallic potassium was used instead of metallic sodium to obtain a fired product powder in which metallic potassium was supported in an amount of 8.4% by weight. When the basic strength of the resulting metallic potassium-supported material was measured using an indicator measurement method, it turned from colorless to yellow at pKa 35.0.It turned yellow due to the adsorption of triphenylmethane, and it was found to be extremely basic with a pKa of 35.0 or higher. It was shown that

Using this metallic potassium supporting material, the same procedure as in Example 1 was carried out (however, stirring conditions were 90°C for 90 minutes).
When the isomerization reaction of 5-vinyl-2-norbornene was carried out, it was confirmed that the entire amount was changed to 5-ethylidene-2-norbornene.

Example 4 Metallic sodium supported material 2 obtained in Example 2
g in a flask under nitrogen gas atmosphere and heated at 60℃.
While heating and stirring, 4-methylpentene-
15g of 1 was added. After 30 minutes, analysis by gas chromatography (Ucon LB-550, 90m) revealed that all of the 4-methylpentene-1 had changed as shown below.

Cis-4-methylpentene-2 12.1% Trans-4-methylpentene-2 12.0% 2-methylpentene-2 75.5% Others 0.4% Comparative Example 1 100 g of alumina (JGC Chemicals N-613N) was
Powder obtained after treatment at 400°C in air for 4 hours (specific surface area 140 m ² /g, maximum base strength is between 15.0 and 17.2 expressed as pKa value by indicator titration)
Place 40g in a 100ml flask, heat to 250℃ under nitrogen gas atmosphere, and stir while stirring.
After adding 4.5 g of metallic sodium in small portions over a period of about 20 minutes, the mixture was stirred as it was for 2 hours.

2 g of the metal sodium support material thus obtained was mixed with 150 g of 5-vinyl-2-norbonene.
was added to the flask containing the mixture, and continued stirring at 80°C for 60 minutes. After the reaction was analyzed by gas chromatography, only 37.7% of 5-vinyl-2-norbornene was changed to 5-ethylidene-2-norbornene, and the rest was unreacted 5-vinyl-2-norbornene.
It was recovered as 2-norbornene.

Comparative Example 2 In Example 4, the material used in Comparative Example 1 was used as the metallic sodium supporting material.
Analysis after 30 minutes revealed that 47% of 4-methylpentene-1 had changed to the following composition ratio, and the rest was recovered as unreacted material.

Cis-4-methylpentene-2 23.2% Trans-4-methylpentene-2 20.5% 2-methylpentene-2 56.7% Example 5 Metallic sodium supported material 2 obtained in Example 1
g was charged into a 100 ml autoclave containing 30 ml of n-decane under a nitrogen gas atmosphere, and 7.0 g of diethylamine and 14.5 g of butadiene were further charged thereto and reacted at 100°C for 2 hours.

The reaction product was analyzed by gas chromatography (PEG-
When analyzed at 20M, 2m), the conversion of diethylamine was 75%, and the product was 2-butenyldiethylamine, a monoadduct of butadiene to diethylamine, at 73%, and the di-adduct at 18%.
It was %.

Comparative Example 3 A powder obtained by calcining commercially available reagent calcium oxide at 850°C for 4 hours in a nitrogen gas atmosphere (specific surface area 20 m ² /g, maximum base strength 26.5 as indicated by pKa value determined by indicator titration method). 27.0)2
Although the addition reaction of butadiene to diethylamine was carried out in the same manner as in Example 5, no product was observed.

Example 6 Metallic sodium supported material 2 obtained in Example 1
A capacity of 100 g is charged with 30 ml of n-decane.
ml autoclave, and add ptadiene.
When 8.5 g was charged and reacted at 50°C for 4 hours, almost the entire amount of butadiene was polymerized and a rubbery polymer was obtained.

Example 7 Sodium metal supported material 2 obtained in Example 1
g was placed in a flask under a nitrogen gas atmosphere, and 400 ml of 3-methyl-1-pentene was added thereto. The reaction was carried out for 15 minutes while controlling the temperature inside the flask at 50-55℃, and after the reaction was completed, the mixture was analyzed by gas chromatography (Ucon LB-550, 90m). As shown below, 3-methyl-1-pentene was detected. everything was changing.

Trans-3-methyl-2-pentene 31.5% Cis-3-methyl-2-pentene 65.1% Other _C6 -olefins 2.7% Others 0.7%

Claims (1)

[Claims] 1 General formula [Mg _1-x Rx(OH) ₂ ] ^x+・[CO _3x/2・mH ₂ O] ^x- [] R: Al, Cr, Fe x: 0<x<0.34 An isomerization reaction catalyst for olefins comprising an alkali metal-supporting material, which is obtained by supporting an alkali metal on a calcined product of a hydrotalcite-related compound represented by m: 0≦m≦5.