JP2005281281A - Isomerization method of alkyl-substituted phenols - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a means for effectively preparing desired alkyl-substituted phenols having large molecular sizes. <P>SOLUTION: The alkyl-substituted phenols is isomerized by making them contact with a catalyst containing mazite zeolite. The isomerization reaction is preferably carried out in the presence of hydrogen. The method is useful for isomerizing cresol, xylenol, trimethylphenol, an alkyl-substituted hydroquinone, etc. In addition to the mazite zeolite, the catalyst preferably contains an inorganic oxide binder and a metal chosen from rhenium, silver, a platinum-group metal, lead, tin, germanium and bismuth. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for isomerizing alkyl group-substituted phenols using a catalyst containing mazaite-type zeolite.

  Individual alkyl group-substituted phenol isomers are used in a wide range of fields. For example, in alkyl group-substituted monohydric phenols, xylenol is useful for synthetic resins, adhesives, insecticide antioxidants, herbicides and the like. Cresols are also useful for disinfectants, synthetic resins, mineral additives, chemical raw materials, agricultural chemicals, and the like. Paracresol is useful in the synthesis of compositions such as bactericides, cresotic acid and dyes. Orthocresol has applications in the preparation of fungicides, coumarins and other intermediates. Metacresol is useful for paints, synthetic resins, fungicides, and the like. Alkyl group-substituted dihydric phenols are useful compounds as intermediates for pharmaceuticals, agricultural chemicals and compounding agents for resins.

As methods for producing alkyl group-substituted monohydric phenols, isomerization methods described in Patent Document 1 and Patent Document 2 are disclosed. However, in order to use a catalyst containing pentasil-type zeolite, two or more alkyl groups were substituted. This is not sufficient for obtaining alkyl-substituted phenols having a large molecular diameter, and the activity is somewhat low. . As methods for producing alkyl group-substituted dihydric phenols, Patent Document 3, Patent Document 4, and Patent Document 5 include divalent phenols and olefins in the presence of an acidic catalyst such as sulfuric acid, phosphoric acid, hydrogen fluoride, and hydrochloric acid. However, the catalyst used in these methods is a highly corrosive catalyst and is not preferable for industrial use. Patent Document 6 discloses a method for producing an alkyl group-substituted divalent phenol in a disproportionation reaction using zeolite as a catalyst. Class has a wide distribution such as 1 to 4 or more alkyl group substitutions on the dihydric phenol skeleton, and the desired alkyl group-substituted dihydric phenol cannot be efficiently obtained. . Patent Document 7 discloses a method for isomerizing alkyl-substituted phenols using Y-type zeolite or beta-type zeolite, but it has a large disproportionation reaction and is not sufficient as an isomerization catalyst.
Japanese Patent Laid-Open No. 5-97738 U.S. Pat. No. 4,283,571 U.S. Pat. No. 2,051,473 U.S. Pat. No. 2,544,818 U.S. Pat. No. 2,831,817 Japanese Patent Laid-Open No. 10-7609 JP 2000-226351 A

  As described above, it is still not sufficient to efficiently obtain alkyl group-substituted phenols having a large molecular diameter even in a conventionally known method.

  Therefore, a method for efficiently obtaining desired alkyl group-substituted phenols with a catalyst having high activity and high isomerization selectivity has been strongly desired.

  As a result of intensive studies to solve the problems, the present inventors have selected high isomerism by using a catalyst containing mazaite-type zeolite in isomerizing a desired alkyl group-substituted phenol isomer. Among the alkyl group-substituted phenols obtained by the above-mentioned properties, the desired alkyl group-substituted phenol is removed, and the unnecessary alkyl group-substituted phenols are further isomerized by contacting with a catalyst containing a mazaite-type zeolite, and the desired alkyl group-substituted phenol is again obtained. By synthesizing phenol, it was found that unnecessary alkyl group-substituted phenols can be used effectively, and the present invention has been achieved. That is, the present invention relates to a method for isomerizing an alkyl group-substituted phenol by contacting with a catalyst containing mazaite-type zeolite.

  According to the present invention, alkyl group-substituted phenols can be isomerized with high isomerization selectivity.

  The present invention is described in detail below. The method for isomerizing an alkyl group-substituted phenol according to the present invention is characterized in that a catalyst containing a mazaite-type zeolite is used as a catalyst in isomerizing a desired isomer of an alkyl group-substituted phenol.

  In the method of the present invention, a catalyst containing mazaite type zeolite is used. In the present invention, a zeolite is a crystalline microporous material, which is a crystalline aluminosilicate having a uniform pore size, a crystalline metallosilicate, a crystalline metalloaluminosilicate, a crystalline aluminophosphate, a crystalline metallo Aluminophosphate is a crystalline silicoaluminophosphate. The metallosilicate and metalloaluminosilicate herein are those in which a part or all of the aluminum of the aluminosilicate is replaced with a metal other than aluminum such as gallium, iron, titanium, boron, cobalt, and chromium. Similarly, metalloaluminophosphate refers to aluminophosphate in which a part of aluminum or phosphorus is substituted with other metal.

  In the present invention, the term “mazite-type zeolite” refers to Atlas of Zeolite Structure types (W Meier, DH Olson, Ch. Baerlocher, WM Meier, DH Olson, Ch. Baerlocher, Zeolites,) 17 (1/2), 1996) (Reference 1). The composition of the mazaite type zeolite is not particularly limited. However, the silica / alumina molar ratio is preferably 7 or more, particularly preferably 9 or more. Moreover, although the mazaite-type zeolite contains various cations as cations, the kind of cations is not particularly limited. However, it is preferable that part or all of the cations are hydrogen ions in order to promote the isomerization reaction.

In order to exchange the cation in the mazeite-type zeolite with hydrogen ions, usually, a method is used in which the zeolite is ion-exchanged with an aqueous acid solution or the cation is ion-exchanged with ammonium ions and then calcined. In addition, when the zeolite contains an organic nitrogen-containing cation in advance, the organic nitrogen-containing cation can be decomposed by calcination and converted into hydrogen ions. Of course, if necessary, metal ions such as sodium present in the zeolite can be ion-exchanged by the above-described ion exchange method when the zeolite is produced. The reason why the isomerization selectivity is high when using mazaite type zeolite is not clear at this time. The isomerization selectivity is defined by the following formula 1.
Isomerization selectivity = (ab) / c (Formula 1)
a: Amount of isomer present after reaction (mol)
b: Amount of isomer contained in raw material before reaction (mol)
c: Total conversion of raw materials (including all isomerization, disproportionation, dealkylation, etc.) (mol)

  High isomerization selectivity means that there are few products (compounds produced by disproportionation) other than the desired alkyl group-substituted phenol isomer. The higher the isomerization selectivity, the more the alkyl group-substituted phenols obtained, except for the desired alkyl group-substituted phenols, the unnecessary alkyl group-substituted phenols are further contacted with a catalyst containing mazaite-type zeolite and isomerized. In synthesizing a desired alkyl group-substituted phenol again, unnecessary alkyl group-substituted phenols can be used more effectively.

  The catalyst of the present invention preferably contains a mazaite type zeolite and an inorganic oxide binder. When the mazite-type zeolite is in a powder form, it is preferably molded for industrial use as a catalyst. There are various molding methods such as a compression molding method, a kneading method, and an oil drop method. The kneading method is preferably used. As the inorganic oxide binder, oxides such as aluminum, titanium, silicon and zirconium and clays such as kaolin, bentonite and montmorillonite are preferable. Examples of the inorganic oxide binder preferably used according to the present invention include alumina sol and alumina gel. Although the ratio of the inorganic oxide binder is not particularly limited, it is 5 to 30 parts by weight, preferably 10 to 20 parts by weight, based on the absolutely dry basis with respect to 100 parts by weight of zeolite. When moldability is poor, it is effective to add an alkali metal salt such as sodium chloride, magnesium chloride or barium chloride or an alkaline earth metal salt during kneading, or a surfactant such as polyvinyl alcohol, span or rhodol. is there.

  Furthermore, the catalyst of the present invention preferably contains at least one selected from rhenium, silver, platinum group metals, lead, tin, germanium and bismuth. By including these metals, when hydrogen is allowed to coexist in the isomerization reaction, there is an effect of improving the activity and extending the catalyst life. As the metal, rhenium, silver, platinum group metals, lead and tin are more preferable, and rhenium and silver are particularly preferable.

  The method of incorporating these metals into the catalyst of the present invention is not particularly limited. However, the inclusion of silver ions can be easily achieved, for example, by ion exchange of a catalyst containing mazaite type zeolite with an aqueous silver nitrate solution. The content of silver ions is preferably 0.5 to 10% by weight, more preferably 1 to 7% by weight in terms of metal based on the catalyst composition. The catalyst composition containing silver ions is effective in suppressing side reactions in the isomerization reaction of alkyl group-substituted phenols. Silver ions contained in the mazeite-type zeolite may become a metal or other silver compound during the reaction, but the catalyst performance is not deteriorated.

  In order to contain rhenium, for example, a supporting method such as an impregnation method or an immersion method in which a catalyst containing mazaite-type zeolite is brought into contact with an aqueous solution of various rhenium compounds is preferable. In particular, when rhenium is supported on the catalyst when isomerizing the alkyl group-substituted phenols in the liquid phase in the presence of hydrogen, rhenium functions as a hydrogenation active component and coats the catalyst active point to poison the catalyst performance. By removing the high-boiling compounds that are used, there is an effect of maintaining the catalytic activity. Examples of rhenium that can be used include perrhenic acid, ammonium perrhenate, and rhenium chloride. The supported amount of rhenium is 0.05 to 2% by weight in terms of metal based on the catalyst composition. More preferably, it is 0.05 to 1% by weight.

  The alkyl group-substituted phenols used in the present invention are phenols having an aromatic ring having one or more side chains, and alkyl group-substituted monohydric phenols or alkyl group-substituted divalent phenols are preferred. The side chain alkyl group is preferably a methyl group, ethyl group, propyl group, butyl group or the like having 1 to 12 carbon atoms, and when two or more alkyl groups are attached to the aromatic ring, the alkyl groups are the same. One or different alkyl groups may be used. For example, isomerize cresol, xylenol, trimethylphenol, ethylphenol, pseudocremol, mesitol, methylethylphenol, propylphenol, methylhydroquinones, methylresorcinols, methylcatechols, and higher molecular weight alkyl-substituted phenols In this case, the present invention is effective.

The feedstock in the present process may contain one or more alkyl group-substituted phenols and may contain other constituents that do not interfere significantly with this isomerization reaction. The reaction of the present invention can be carried out either by flow or batch. From the viewpoint of productivity, a fixed bed flow reaction in which the catalyst is used as a fixed bed and an alkyl group-substituted phenol is passed through the bed is preferable. The reaction is carried out with heating, but the reaction temperature is usually 100 ° C to 500 ° C, preferably 200 ° C to 400 ° C. The reaction pressure is not particularly limited, and can be set to any pressure from normal pressure. The weight space velocity (WHSV), which is the feed rate of the raw material per catalyst weight during the reaction, is not particularly limited, but is usually 0.01 to 50 hr ⁻¹ , preferably 0.1 to 10 hr ⁻¹ .

  In the reaction of the present invention, it is preferable that hydrogen is allowed to coexist from the viewpoint of activity improvement and catalyst life. The coexistence amount of hydrogen may be arbitrary. The alkyl group-substituted phenols obtained by isomerization do not appear to be an important factor for the present invention as to what product recovery system is used. Any recovery method known in the prior art may be used. For example, distillation, crystallization from a corresponding solvent, selective adsorption using zeolite, and the like. Preferred is selective adsorption separation using zeolite.

  Hereinafter, the present invention will be described with reference to examples.

(Example 1) Mazite-type zeolite synthesis Hydrous silicic acid as a silica source (SiO ₂ content 91.6 wt%, Al ₂ O ₃ content 0.33 wt%, NaOH content 0.27 wt%, H ₂ O content 7.8 wt%, Nip seal VN-3, Nippon Silica), aluminum nitrate nonahydrate (Wako Pure Chemical Industries) as an aluminum source, sodium hydroxide (NaOH content, Sigma-Aldrich Japan) as a sodium source, tetramethylammonium as a zeolite structure-directing agent Using hydroxide (tetramethylammonium hydroxide 25 wt% aqueous solution, Sigma-Aldrich), a mixture having the following composition was prepared.
7.2Na ₂ O: Al ₂ O ₃ : 20SiO ₂ : 3.6R ⁺ OH ⁻ : 315H ₂ O (molar ratio)
(R ⁺ OH ^-: tetramethyl aminoalcohol hydroxide)

  Specifically, 3.43 g of sodium hydroxide was dissolved in 25.63 g of distilled water, and then 7.88 g of tetramethylammonium hydroxide 25 wt% aqueous solution and 4.41 g of aluminum nitrate nonahydrate were added. The mixture was stirred for 30 minutes to obtain a uniform solution. To this mixed solution, 7.87 g of hydrous silicic acid was gradually added with stirring, and the mixture was further stirred for 2 hours to prepare a uniform slurry-like aqueous reaction mixture. The reaction mixture was put in a 100 ml Teflon (registered trademark) autoclave (manufactured by HIRO) and sealed, and then reacted at 100 ° C. for 4 days with stirring at 20 rpm in a constant temperature bath (manufactured by HIRO).

After completion of the reaction, washing with distilled water three times and filtration were repeated, followed by drying at about 120 ° C. overnight. The obtained product was a mazaite type zeolite. This zeolite had a SiO ₂ / Al ₂ O ₃ composition ratio (mole) of 9.6.

(Example 2) Catalyst preparation The mazite-type zeolite obtained as described above was calcined at 500 ° C for 2 hours, and then 10 wt% aqueous ammonium chloride solution was used for 30 minutes at a weight ratio of aqueous ammonium chloride / zeolite = 10 for 75 minutes. Ion exchange was performed three times at 0 ° C. Thereafter, washing with water was performed three times at 75 ° C. for 30 minutes at a weight ratio of distilled water / zeolite = 10, drained, dried at about 120 ° C. overnight, and calcined at 540 ° C. for 3 hours to obtain a mazeite-type zeolite catalyst. Was prepared.

(Reference Example 1) Catalyst Preparation Y-type zeolite (HSZ-320NAA manufactured by Tosoh Corporation, SiO ₂ / Al ₂ O ₃ = 5.5) was used in a 10 wt% ammonium chloride aqueous solution, and a weight ratio of ammonium chloride aqueous solution / zeolite = 10. The ion exchange was performed 3 times at 75 ° C. for 30 minutes. Thereafter, washing with water was carried out three times at 75 ° C. for 30 minutes at a weight ratio of distilled water / zeolite = 10, drained, dried at about 120 ° C. overnight, and calcined at 540 ° C. for 3 hours. Was prepared.

(Reference Example 2) Catalyst preparation Beta-type zeolite (CP806B-25 manufactured by PQ Corporation, SiO ₂ / Al ₂ O ₃ = 25) was calcined at 500 ° C. for 2 hours, and then chlorinated using a 10 wt% ammonium chloride aqueous solution. Ion exchange was performed 3 times at 75 ° C. for 30 minutes at a weight ratio of aqueous ammonium solution / zeolite = 10. Thereafter, washing with water was performed three times at 75 ° C. for 30 minutes at a weight ratio of distilled water / zeolite = 10, drained, dried at about 120 ° C. overnight, and calcined at 540 ° C. for 3 hours to form a beta zeolite catalyst Was prepared.

(Reference Example 3) Catalyst preparation Mordenite type zeolite (HSZ-620HOA, Tosoh Corp., SiO ₂ / Al ₂ O ₃ = 15) is a hydrogen ion type, so it is only calcined at 500 ° C for 1 hour before use to remove moisture. A mordenite-type zeolite catalyst was prepared.

(Reference Example 4) Zeolite synthesis / catalyst preparation (pentacil type zeolite)
Solid caustic soda (NaOH content 96.0 wt%, H2 O content 4.0 wt%, Katayama Chemical) 7.3 grams, tartaric acid powder (tartaric acid content 99.7 wt%, H2 0 content 0.3 wt%, Katayama Chemical) 10.2 Grams was dissolved in 583.8 grams of water. To this solution, 35.4 grams of sodium aluminate solution (Al ₂ O ₃ content 18.5 wt%, NaOH content 26.1 wt%, H ₂ 0 content 55.4 wt%, Sumitomo Chemical) was added to obtain a uniform solution. While stirring 111.5 grams of silicic acid powder (SiO ₂ content 91.6 wt%, Al ₂ O ₃ content 0.33 wt%, NaOH content 0.27 wt%, nip seal VN-3, Nippon Silica) In addition, a homogeneous slurry aqueous reaction mixture was prepared. The composition ratio (molar ratio) of this reaction mixture was as follows.

SiO ₂ / Al ₂ O ₃ 25
H ₂ O / SiO ₂ 20
OH- / SiO ₂ 0.164
A / Al ₂ O ₃ 1.0 A: Tartrate The reaction mixture was sealed in a 1000 ml autoclave and then reacted at 160 ° C. for 72 hours with stirring at 250 rpm. After completion of the reaction, washing with distilled water 5 times and filtration were repeated, followed by drying at about 120 ° C. overnight. The obtained product was a pentasil-type zeolite having the X-ray diffraction pattern shown in Table 1. The silica / alumina molar ratio of the zeolite was 21.9 as a result of composition analysis.

  The pentasil-type zeolite obtained as described above was calcined at 500 ° C. for 2 hours, and then ion exchange was performed at 75 ° C. for 30 minutes using a 10 wt% ammonium chloride aqueous solution at a weight ratio of ammonium chloride aqueous solution / zeolite = 10. I went twice. Thereafter, washing with water is carried out three times at 75 ° C. for 30 minutes at a weight ratio of distilled water / zeolite = 10, drained, dried at about 120 ° C. overnight, and calcined at 540 ° C. for 3 hours. Was prepared.

(Example 3) Isomerization reaction The mazaite-type zeolite catalyst obtained in Example 2 was cooled in a desiccator, and 0.3 g of the catalyst and 1.5 ml of 2,4-xylenol (Tokyo Chemical Grade 1) were placed in a stainless steel autoclave. And reacted at 250 ° C. for 4 hours. After completion of the reaction, the reaction product was analyzed by gas chromatography. The results are shown in Table 1.

(Comparative Example 1) Isomerization reaction The same procedure as in Example 3 was performed except that the catalyst obtained in Reference Example 1 was used. The results are shown in Table 1.

(Comparative Example 2) Isomerization reaction The same procedure as in Example 3 was performed except that the catalyst obtained in Reference Example 2 was used. The results are shown in Table 1.

(Comparative Example 3) Isomerization reaction The same procedure as in Example 3 was performed except that the catalyst obtained in Reference Example 3 was used. The results are shown in Table 1.

(Comparative Example 4) Isomerization reaction The same procedure as in Example 3 was conducted except that the catalyst obtained in Reference Example 4 was used. The results are shown in Table 1.

(Comparative Example 5) Isomerization reaction The reaction was conducted in the same manner as in Comparative Example 1 except that the reaction was performed at 225 ° C. The results are shown in Table 2.

(Comparative Example 6) Isomerization reaction The reaction was conducted in the same manner as in Comparative Example 2 except that the reaction was performed at 225 ° C. The results are shown in Table 2.

  As is clear from Table 1, the mordenite type zeolite and the pentasil type zeolite had low activity, and the isomerization selectivity was inferior to that of the mazaite type zeolite. Further, as is apparent from Table 2, when compared at almost the same conversion rate, the mazeite type zeolite had the highest isomerization selectivity. Thus, it has been found that a catalyst containing mazaite-type zeolite is useful in the isomerization reaction of alkyl group-substituted phenols.

  According to the present invention, alkyl-substituted phenols useful as intermediates for pharmaceuticals, agricultural chemicals, resin compounding agents, and the like can be isomerized, so that desired isomers can be obtained.

Claims (7)

A method for isomerizing an alkyl group-substituted phenol, characterized in that the alkyl group-substituted phenol is brought into contact with a catalyst containing a mazaite-type zeolite for isomerization. 2. The method for isomerizing an alkyl group-substituted phenol according to claim 1, wherein hydrogen is allowed to coexist. The method for isomerizing an alkyl group-substituted phenol according to claim 1 or 2, wherein the catalyst containing mazaite-type zeolite contains mazaite-type zeolite and an inorganic oxide binder. The alkyl group substitution according to any one of claims 1 to 3, wherein the catalyst containing mazite-type zeolite contains at least one selected from rhenium, silver, platinum group metals, lead, tin, germanium and bismuth. Isomerization method of phenols. The method for isomerizing an alkyl group-substituted phenol according to any one of claims 1 to 4, wherein the alkyl group-substituted phenol is an alkyl group-substituted monohydric phenol or an alkyl group-substituted divalent phenol. The method for isomerizing an alkyl group-substituted phenol according to any one of claims 1 to 5, wherein the alkyl group of the alkyl group-substituted phenol has 1 to 12 carbon atoms. The method for isomerizing an alkyl group-substituted phenol according to claim 5 or 6, wherein the alkyl group-substituted phenol is cresol, xylenol, trimethylphenol or an alkyl-substituted hydroquinone.