JP2977334B2 - Method for producing polyalkylbenzene and catalyst - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a trialkylbenzene or a tetraalkylbenzene (hereinafter collectively referred to as "polyalkylbenzene") by alkylating an alkylbenzene with an olefin, and a catalyst used in the production method. is there. The produced polyalkylbenzene is useful as a raw material of trimellitic acid or pyromellitic anhydride, trimellitic acid is used as a raw material of a heat-resistant plasticizer, and pyromellitic anhydride is used as a raw material of a polyimide resin or an epoxy resin curing agent. .

[0002]

2. Description of the Related Art General catalysts used in a process for producing polyalkylbenzene by alkylating an aromatic hydrocarbon with an olefin are roughly classified into the following four types. (1) Aluminum chloride-Friedel such as hydrogen chloride-
Crafts type catalyst, (2) mineral acid catalyst such as hydrogen fluoride-boron fluoride, (3) aromatic sulfonic acid catalyst such as benzenesulfonic acid and paratoluenesulfonic acid, (4) solid acid such as silica alumina and zeolite catalyst.

A method using a Friedel-Crafts type catalyst is described in, for example, Japanese Patent Publication No. 52-12178, in which 1,2,4,5-tetraalkylbenzene is converted from meta-xylene and propylene. In the production, a mixed catalyst of anhydrous aluminum chloride and anhydrous iron chloride is used. In general, with a Friedel-Crafts type catalyst such as aluminum chloride, undesirable side reactions such as isomerization and polymerization tend to occur, and it is difficult to improve the selectivity of the reaction. Thus, the selectivity of the target 1,2,4,5-tetraalkylbenzene is greatly improved by combining with iron chloride, but the 1,2,4,5-form in the obtained tetraalkylbenzene is improved. Is occupied in the 70% range, which is not a satisfactory level. Further, in this method, a relatively large amount of the catalyst is used, and since the catalyst is disposable without being separated and collected, a process such as wastewater treatment is also required, which is hardly an advantageous method.

A method using a mineral acid catalyst such as hydrogen fluoride-boron fluoride is described, for example, in Japanese Patent Publication No. 52-3369, in which 5-isopropylpseudocumene is produced from pseudocumene and propylene. Is used as a catalyst. This method requires a large amount of catalyst in equimolar or more with respect to pseudocumene as a raw material, and there is a limitation in the material of the apparatus because the catalyst is highly corrosive. Further, in order to suppress the by-product of diisopropylpseudocumene, the allowable range of the molar ratio of propylene to pseudocumene is as narrow as 0.8 to 1.0, and the desired 5-isopropyl in the produced monoisopropylpseudocumene is further reduced. The ratio of pseudocumene is also low at around 60%.

A method using an aromatic sulfonic acid catalyst such as benzenesulfonic acid is disclosed, for example, in Japanese Patent Publication No. 47-27673.
And the Japan Petroleum Institute, Vol. 16, No. 2, pp. 117-122 (1973)
), In which benzenesulfonic acid or paratoluenesulfonic acid is used as a catalyst in the production of 5-isopropyl pseudocumene from pseudocumene and propylene. This method also requires a large amount of a catalyst, and isopropyl sulfonic acid generated during the reaction becomes an active species. Therefore, the method is easily affected by water, and it is necessary to remove water contained in the catalyst in advance. Also,
The proportion of 5-isopropylpseudocumene in the product monoisopropylpseudocumene is of the order of 70%, which is not satisfactory, and there are many by-product diisopropylpseudocumene.

A method using a solid acid catalyst such as zeolite is described in, for example, JP-A-48-85540, in which paraxylene and propylene are used to prepare 1,2,2.
A catalyst in which zeolite is stabilized with silica alumina when producing 4,5-tetraalkylbenzene is used. Since this catalyst is a solid, it can be easily separated and recovered after the reaction, and is an industrially advantageous catalyst as compared with the above three types of catalysts. The desired 1,2,4,5-diisopropyldimethyl Benzene yield is as high as about 90%. However, preparation of the catalyst such as stabilization treatment of zeolite, which is a main component of the catalyst, with silica alumina and high-temperature treatment before the reaction is complicated, and a large amount of catalyst is required for the reaction. During the reaction, the activity of the zeolite decreases due to blockage of the pores.

The reactions using the above four types of catalysts are all liquid phase reactions, but a method of producing polyalkylbenzene by reacting an aromatic hydrocarbon with an olefin in a gas phase using a catalyst is also known. . Such methods include:
A method for producing paradialkylbenzene from monoalkylbenzene and olefin (see Japanese Patent Application Laid-Open No. 61-212136) and a method for producing polyalkylbenzene from dialkylbenzene and / or trialkylbenzene and methanol and / or dimethylether (see Japanese Patent Application Laid-open No. Sho 63/1987).
-14735). Both of these two methods use a crystalline aluminosilicate modified with a heteropoly acid or a salt thereof as a catalyst to carry out a reaction in a gas phase. However, the catalyst is required to be 400 to 6 before the reaction.
Since the preparation is performed at 50 ° C., the heteropolyacid in the catalyst is decomposed, and the heteropolyacid itself does not effectively contribute to the reaction. The alkylation reaction in the gas phase is
Since olefins and alcohols used as the alkylating agent are easily precipitated as carbonaceous materials on the catalyst, it is necessary to reduce the ratio of the alkylating agent to the alkylbenzene as the raw material, and therefore it is difficult to increase the raw material conversion and the yield.

[0008]

SUMMARY OF THE INVENTION The present invention relates to 1, 2,
To provide a production method capable of stably producing 4, -trialkylbenzene or 1,2,4,5-tetraalkylbenzene with high selectivity and high yield and easily recovering and reusing a catalyst. It is intended for.

[0009]

The present inventors have found that when heteropolyacids are used as catalysts, 1,2,4-trialkylbenzenes and 1,1,4-trialkylbenzenes can be used as compared with the conventional four kinds of catalysts which have been used conventionally. The present inventors have found that 2,4,5-tetraalkylbenzene can be produced with extremely high selectivity and high yield, and as a result of further intensive studies, the present invention has been completed. The present invention is a method for producing 1,2,4-trialkylbenzene or 1,2,4,5-tetraalkylbenzene in which an alkylbenzene and an olefin are reacted in a liquid phase using a heteropolyacid as a catalyst. Specific examples of the raw material alkylbenzene include toluene, xylene, and pseudocumene. As the alkylating agent to be reacted with the alkylbenzene, an olefin having 2 to 5 carbon atoms is used. Specific examples of such olefins include ethylene, propylene, 1-butene, isobutene, 1-pentene, and isopentene.

A variety of heteropolyacids can be used as the catalyst. Among them, the general formula HaX ₁ Y ₁₂
O ₄₀ .nH ₂ O (where H is hydrogen, X is phosphorus or silicon,
Y represents at least one element selected from tungsten, molybdenum and vanadium; O represents oxygen;
Keggin-type heteropolyacid represented by Y) is particularly preferred since it has particularly excellent catalytic performance. Also,
Examples of the heteropolyacid salt used as a catalyst include those in which part or all of H of Ha in the heteropolyacid of the above general formula is substituted with an alkali metal, an alkaline earth metal, various transition metals or amines.

It is possible to obtain the desired polyalkylbenzene with good selectivity by using these heteropolyacids and / or heteropolyacid salts as they are as catalysts.
In order to increase the activity of the catalyst and to allow the catalyst after the reaction to be easily separated, recovered, and reused, it is preferable to use the catalyst supported on a carrier and fixed. In this case, a carrier that does not adversely affect the reaction, is stable to the heteropolyacid, and has a high surface area is preferable, and specific examples thereof include silica, titania, and activated carbon. An impregnation method is simple as a supporting method. The supported amount of the heteropolyacid depends on the surface area of the support, and the activity increases with the supported amount. However, the heteropolyacid is in the range of 1 to 50% by weight, more preferably 10 to 40% by weight based on the whole catalyst. . This supported heteropolyacid catalyst is
Although it may be used in the reaction as it is after loading, it is preferable to stabilize by pretreatment at a temperature higher than the reaction temperature. The pretreatment temperature is in the range of 100 to 400C, more preferably in the range of 150 to 300C, depending on the type of the heteropolyacid.

As a reaction method, a raw material alkylbenzene and a supported heteropolyacid catalyst or a non-supported heteropolyacid catalyst are charged into a reaction vessel, and after sealing, a predetermined amount of olefin is sealed therein. Is performed. The olefin may be continuously supplied after reaching the reaction temperature. The reaction temperature can be set in a wide range from 150 to 300 ° C., but from the viewpoint of the selectivity of the reaction and the catalyst life,
The range of -200 ° C is preferred. Although a solvent is not particularly necessary, it can be diluted with a suitable solvent, for example, normal decane or the like, in order to allow the reaction to proceed gently.

The molar ratio of the raw material alkylbenzene to the olefin as the alkylating agent varies depending on the raw material and the target polyalkylbenzene, but is intended for monoalkylation in which one molecule of olefin is added to one molecule of olefin. Is in the range of 1: 0.1 to 2, more preferably in the range of 1: 0.8 to 1.2, and for the purpose of dialkylation, in the range of 1: 1 to 10, more preferably 1: 2. It is in the range of 1.2 to 3. When the reaction is carried out by the above method, the supported heteropolyacid catalyst or the unsupported heteropolyacid catalyst can be easily separated and recovered from the reaction solution by filtration. At this time, no elution of the heteropoly acid into the reaction solution was observed. The recovered catalyst could be used for the next reaction as it was, and the activity selectivity was not different from the unused catalyst. It is not particularly necessary to regenerate the catalyst after the reaction. However, since the reaction solution is attached to the surface of the catalyst, the catalyst may be washed with a solvent, if necessary, heated to evaporate the solvent, and then reused.

[0014]

According to the present invention, 1,2,4, -trialkylbenzene and 1,2,4,5-tetraalkylbenzene can be stably produced with high selectivity and high yield. Further, recovery and reuse of the catalyst are facilitated.

[0015]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the examples.
The conversion and selectivity in the examples are based on the following definitions. Conversion (mol%) = {(mol number of raw material consumed) / (mol number of raw material supplied)} × 100 Selectivity (mol%) = {(mol number of generated polyalkylbenzene) / (consumption The raw material is an alkylbenzene. In addition, the position selectivity (mol%) = {(1,2,4-tri or 1,2,
The number of moles of 4,5-tetraalkylbenzene)} / (the number of moles of tri- or tetraalkylbenzene formed)} × 100

Example 1 Preparation of Supported Heteropolyacid Catalyst In a 200 ml eggplant-shaped flask, 7.6 g of 12-tungstosilicic acid (manufactured by Nippon Inorganic Chemical Industry) was dissolved in 50 cc of ion-exchanged water. 3
00m ^{2 /} g) and evaporate to dryness on a water bath at 40-50 ° C. with a rotary evaporator to convert 12-tungstosilicic acid to silica gel.
Weight percent supported heteropolyacid catalyst (30% by weight
Expressed as SiW ₁₂ / SiO ₂ . Hereinafter, similar expressions are used for other supported heteropolyacid catalysts. ) Was prepared. The catalyst was dried in air at 120 ° C., and calcined at 300 ° C. for 2 hours to be used for the reaction.

[0017] Meta-xylene 30.0g in SUS316 steel autoclave isopropylated Contents 100 ml, supported heteropolyacid catalyst (30 wt% SiW ₁₂ / SiO ₂₎ was charged 0.5g, the air in the reaction vessel was replaced with nitrogen. The temperature was raised while stirring the reaction vessel,
The reaction temperature was adjusted to 160 ° C. At this time, the internal pressure was about 2 kg / cm ² at natural pressure. Next, propylene gas was blown in at a flow rate of 110 ml / min (STP) for 2 hours so that the molar ratio of meta-xylene to propylene was 1: 2.10. Thereafter, the temperature was maintained at 160 ° C. for 1 hour, and the total reaction time was 3 hours. After the reaction, the autoclave was cooled to around room temperature, and the reaction solution and the catalyst were separated by filtration. Fluorescent X
As a result of analysis by a line analyzer, no elution of heteropolyacid was observed. When the composition of the reaction solution was analyzed and quantified by gas chromatography, the conversion of meta-xylene as a raw material was 99%.
Mol%, the selectivity of the product monoisopropylxylene is 14 mol%, of which 72% is the 1,2,4-trialkyl compound and the selectivity of the product diisopropylxylene is 8%.
5 mol%, of which 95% was a 1,2,4,5-tetraalkyl compound. Table 1 shows the reaction conditions and the results.

Example 2 A reaction was carried out in the same manner as in Example 1 except that the amount of propylene was changed in order to mainly produce a monoisopropyl compound, and a high conversion and a high selectivity were obtained. . Table 1 shows the reaction conditions and the results.

(Examples 3 to 7) The reaction was carried out in the same manner as in Example 1 except that the kind, the supporting amount or the carrier of the heteropolyacid was changed. Table 1 shows the catalysts, reaction conditions and the results. Also in this case, a high conversion and a high selectivity are obtained.

(Eighth Embodiment) In the eighth embodiment, 12-
The reaction was carried out using a partial cesium salt in which two Hs of tungstosilicic acid were substituted with Cs as a catalyst. The catalyst is 1
5.2 Tungstosilicic acid 5.2 g and cesium nitrate 0.59
g was dissolved in 20 cc of ion-exchanged water, and the two solutions were mixed to form white sediment, followed by evaporation to dryness on a 40-50 ° C. water bath using a rotary evaporator. The catalyst was calcined at 300 ° C. for 2 hours and used for the reaction. Table 1 shows the reaction conditions and the results.

(Examples 9 to 16) The reaction was carried out in the same manner as in Examples 1 to 8 except that the starting material was changed to para-xylene. catalyst,
Table 2 shows the reaction conditions and the results. Also in this case, a high conversion and a high selectivity are obtained.

(Examples 17 to 25) The reaction was carried out in the same manner as in Examples 1 to 16, except that the raw material was changed to pseudocumene.
Table 3 shows the catalysts, reaction conditions and the results. Example 17
-22, a high conversion and a high selectivity were obtained. In Example 23, the conversion was reduced because the heteropolyacid was used as it was without using a carrier. In Example 25, ethylene was used instead of propylene as the alkylating agent, but the conversion was slightly inferior to propylene.

Examples 26 to 30 In Examples 26 to 28, the reaction was carried out using toluene as a raw material and propylene, 1-butene and ethylene as alkylating agents, respectively. The target polyalkylbenzene can be obtained also by using toluene as a raw material. Example 2
In Examples 9 and 30, the supported heteropolyacid catalyst separated after the reaction in Examples 1 and 19 was used as it was, and the same reaction was performed again. The catalyst activity did not decrease even after reuse. Table 4 shows the reaction conditions and the results.

[0024]

[Table 1]

[0025]

[Table 2]

[0026]

[Table 3]

[0027]

[Table 4]

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-63-225326 (JP, A) Bull. Chem. Soc. Jpn. , Vol. 62, No. 7 (1989) p. 2159-p. 2162 (58) Field surveyed (Int.Cl. ⁶ , DB name) C07C 2/70 C07C 15/02 CA (STN) CAOLD (STN) REGISTRY (STN)

Claims (4)

(57) [Claims] [Claim 1] (R is methyl, ethyl or isopropyl, in the case of plural, same or different, n is 1 to 3), and using an olefin having 2 to 5 carbon atoms as an alkylating agent, heteropolyacid and / or heteropolyacid 150 in liquid phase with salt as catalyst
A method for producing a polyalkylbenzene, comprising producing a trialkylbenzene or a tetraalkylbenzene by reacting at -300 ° C. 2. The method for producing a polyalkylbenzene according to claim 1, wherein the heteropolyacid and / or the heteropolyacid salt is used as a catalyst in a form supported on a carrier. (3) (R is methyl, ethyl or isopropyl, a plurality case of same or different, n represents 1 to 3) to the raw material, by using an olefin having 2 to 5 carbon atoms as an alkylating agent, in the liquid phase 1
A catalyst for producing a trialkylbenzene or a tetraalkylbenzene by reacting at 50 to 300 [deg.] C. , wherein the catalyst comprises a heteropolyacid and / or a heteropolyacid salt. 4. The catalyst according to claim 3, wherein the heteropolyacid and / or the heteropolyacid salt is supported on a carrier.
The catalyst for producing a polyalkylbenzene according to the above.