JPS6361931B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention selectively alkylates the ortho-position hydrogen atoms of a phenol compound using a metal oxide-containing catalyst that is reduced before use in the reaction and then catalyzed with water vapor to form at least one ortho-alkyl group. The present invention relates to the production of orthoalkylated phenolic compounds having the following properties. Up until now, much research has been carried out on methods for producing orthoalkylated phenolic compounds, especially since 2,6-dimethylphenol is a raw material for producing polyphenylene ether (PPE), a useful plastic. There is. As a method for orthoalkylating phenolic compounds, a method is already known in which a phenol compound and an alcohol are subjected to a gas phase contact reaction using alumina, magnesia, etc. as a catalyst. There are problems such as poor selectivity and too high reaction temperature. In order to solve these problems, various catalyst systems have been disclosed, including those in which various components are added to magnesia, and those in which iron oxide, manganese oxide, etc. are the main components, and other components are added thereto. Both have drawbacks in terms of ortho-position selectivity and catalyst life, and cannot be said to be sufficient catalysts. The present inventors have conducted various studies on this alkylation method and have proposed various effective catalysts. After this, we further investigated these catalyst systems in detail, and found that metal oxide-containing catalysts that were reduced before reaction use and then contact-treated with steam had excellent initial stability of reaction activity, and also showed shortening of catalyst life. The present inventors have discovered that the method of the present invention is also excellent. The phenol compound used in the present invention has at least one hydrogen atom in the ortho position, and has the general formula (1) (In the formula, R ₁ , R ₂ , R ₃ and R ₄ represent a saturated hydrocarbon group having 1 to 4 hydrogen atoms, or an aromatic hydrocarbon group such as unsubstituted or substituted phenyl or naphthyl.) It will be done. For example, phenol,
O-・m or P-cresols, 2,3-・
2,4-・3,4- or 3,5-xylenols, trimethylphenols, tetramethylphenols, various ethylphenols, n-・
Iso- or tert-butylphenols, phenylphenols, naphthylphenols, etc. can be used in the present invention, and phenol compounds in which one or more different functional groups are substituted on the aromatic ring can be used. The alcohols used in the present invention are lower alcohols having 1 to 4 carbon atoms, such as methanol, ethanol, n-propanol, iso-
These include propanol, n-butanol, iso-butanol, tert-butanol, and the like. Examples of the metal oxide-containing catalyst used in the method of the present invention include an aluminum oxide-containing catalyst, a magnesium oxide-containing catalyst, a manganese oxide-containing catalyst, a chromium oxide-containing catalyst, an iron oxide-containing catalyst, and a zeolite-containing catalyst. That is, (1) an aluminum oxide-containing catalyst is one that contains aluminum oxide alone or as a main component, and also contains silicon oxide and alkali metals, and (2) a magnesium oxide-containing catalyst is a catalyst that contains magnesium oxide as a main component, tin oxide,
A catalyst containing one or more selected from manganese oxide, copper oxide, lanthanide, actinide, bismuth oxide, and boron oxide. It contains one or more selected from alkali metals, alkaline earth metals, and sulfuric acid radicals, and (4) chromium oxide-containing catalyst is mainly composed of chromium oxide, tin oxide, iron oxide, Contains one or more selected from manganese oxide, silicon oxide, boron oxide, alkali metals, alkaline earth metals, and sulfuric acid radicals, (5)
Iron oxide-containing catalysts include iron oxide alone or iron oxide as a main component, and one or two selected from silicon oxide, chromium oxide, lead oxide, manganese oxide, vanadium oxide, alkali metals, and alkaline earth metals. (6) Zeolite-containing catalysts include protons, lanthanum, nickel, copper,
These include those containing one or more cations selected from manganese, chromium, cobalt, boron, zinc, cadmium, alkali metals, and alkaline earth metals. Among these metal oxide-containing catalysts, magnesium oxide-containing catalysts, manganese oxide-containing catalysts, and chromium oxide-containing catalysts are particularly suitable in the method of the present invention. As raw materials for various oxides used in the present invention, common compounds such as oxides, hydroxides, halides, various mineral acid salts, carbonates, and organic acid salts of the respective metals can be used. The catalyst can be prepared by mixing various raw materials, adding a small amount of water, and kneading with a kneader or mixer, or by making various raw materials into an aqueous solution, adding a basic component to this, and coagulating it as an insoluble precipitate. Various general methods can be applied, such as precipitation and, in the case of zeolite-containing catalysts, preparation by conventional ion exchange methods. The resulting catalyst composition is typically dried at a temperature below 180°C, and the resulting catalyst composition is dried at a temperature of 180°C or lower, and is then dried to form a crystalline cellulose, starch, PVA, MMA
The catalyst composition may be used by adding appropriate granulation additives and forming aids and molding by methods such as extrusion molding, compression molding, vibration molding, and rolling molding, or by crushing the catalyst composition as it is. . The contact treatment with water vapor of the metal oxide-containing catalyst used in the method of the present invention is carried out in the following manner: When the dry product of the catalyst composition is calcined in a reducing gas atmosphere and then the contact treatment is carried out with water vapor, it is carried out in air or in nitrogen. When a pre-calcined catalyst is reduced in a reducing gas atmosphere and then subjected to contact treatment with steam, there are two cases, both of which are applicable. The reducing gases used here are hydrogen, carbon monoxide, ammonia, methanol, ethanol,
Methane, ethane, propane, butane and their mixtures include hydrogen, carbon monoxide,
and mixed gases thereof are more preferred. Also,
The above-mentioned reducing gas may be diluted with nitrogen, carbon dioxide, water vapor, etc. before use. Normal reduction processing is 100
-800°C, preferably 150-650°C for 0.3-30 hours, and for 0.5-50 hours. Similarly, the method of the present invention can be achieved by activating and reducing a catalyst used in the reaction with reduced activity using oxygen and steam, and then subjecting it to contact treatment with steam. The contact treatment with steam in the method of the present invention is effective for stabilizing the surface of the reduced catalyst and adjusting the degree of surface reduction of a catalyst that is excessively reduced. As a result, the so-called induction period is significantly reduced, the reaction becomes more stable from the start of the reaction, and the life of the catalyst is extended. When carrying out the method of the present invention, the molar ratio of the phenol compound and alcohol to be supplied is 1:1 to 1:
15 is suitable, and 1:1 to 1:8 is more preferable. It is effective to use nitrogen, carbon dioxide, argon, or the gas generated when carrying out the present invention to supply the raw materials to the reaction system in order to make the reaction proceed smoothly. Furthermore, carrying out the reaction by mixing water into the reaction raw materials is advantageous in terms of catalyst life and alcohol utilization. In the method of the invention, the reaction temperature is in the range of 250-580°C, preferably 300-530°C. The raw material supply to the reaction system is based on liquid hourly space velocity (LHSV).
and preferably 0.1 to 10. The reaction can be carried out under normal pressure, reduced pressure, or increased pressure, and the reaction mode can be fixed bed, fluidized bed, or moving bed, although the fixed bed method is common. The present invention will be explained below with reference to Examples. Example 1 and Comparative Example 1 Chromium nitrate nonahydrate 500g, stannous chloride dihydrate 50g
g and 25 g of ferric nitrate nonahydrate are dissolved in water 5 with 350 g of urea and heated on a heater,
A precipitate formed. Next, 1 g of potassium hydrogen sulfate was added to the formed precipitate, and after being left overnight, it was washed with water, filtered, and dried at 170°C. The resulting catalyst composition is
Calcinate in air at 500℃ for 5 hours, then adjust the particle size to 20 to 32 mesh, fill two glass reaction tubes with 6 c.c. each, and heat at 450℃ for 10 hours until the ratio of hydrogen and nitrogen is adjusted. A 2:1 mixed gas was introduced to carry out the reduction treatment. Steam was introduced into only one reaction tube (GR-A) to perform catalyst contact treatment, and the other reaction tube (GR-B) was used for the reaction as it was. A reaction solution with a molar ratio of phenol and methanol of 1:5 was heated and vaporized at 250°C, and then placed in two reaction tubes whose internal temperature was adjusted to 390°C at 2.4 molar ratios per hour.
g was introduced and a comparative reaction was performed. The results are shown in Table 1. Example 2 and Comparative Example 2 Manganese nitrate hexahydrate 500g, water glass No. 3 12g
was dissolved in water 4, and aqueous ammonia was added to form a precipitate. Add 0.2g of cesium nitrate to this,
I left it overnight. It was washed with water, filtered and dried at 170°C. The obtained catalyst was crushed to have a particle size of 20 to 32 meshes, and 5 c.c. each was filled into two glass reaction tubes, and the mixture was heated at 450°C for 8 hours at a hydrogen:nitrogen ratio of 2:1. A mixed gas of Steam was introduced into only one reactor (GR-A) to carry out catalyst contact treatment, and the other reactor (GR-B) was used as it was for the reaction. A reaction solution with a molar ratio of phenol and methanol of 1:5 was heated and vaporized at 250°C, and then placed in two reaction tubes whose internal temperature was adjusted to 430°C at 2.3 molar ratios per hour.
g was introduced and a comparative reaction was performed. The results are shown in Table 1.

[Table] Example 3 and Comparative Example 3 Magnesium nitrate 400g, stannous chloride dihydrate 60g
g was dissolved in water 3, and aqueous ammonia was added to form a precipitate. 0.1 g of rubidium nitrate was added to this and left overnight. Wash it, strain it, 170
Dry at °C. Crush the resulting catalyst, 20-32
The particle size of the mesh was adjusted, and 6 c.c. each was filled into two glass reaction tubes, and a mixed gas of hydrogen and nitrogen with a ratio of 2:1 was introduced at 550℃ for 8 hours to perform the reduction treatment. Summer. Steam was introduced into only one reactor (GR-A) to carry out catalyst contact treatment, and the other reactor (GR-B) was used as it was for the reaction. A reaction solution with a molar ratio of phenol and ethanol of 1:10 was heated and vaporized at 250°C, and then placed in two reaction tubes whose internal temperature was adjusted to 440°C at a rate of 1.5 per hour.
g was introduced and a comparative reaction was performed. The results are shown in Table 2.

[Table] Example 4 and Comparative Example 4 Chromium nitrate nonahydrate 500g, stannous chloride dihydrate 25g
g, 10 g of aluminum nitrate and 10 c.c. of an aqueous sulfuric acid solution (3.6N) were dissolved in 3 ml of water, and aqueous ammonia (10%) was added to form a precipitate. This precipitate was washed with water, filtered, and dried at 170°C. The obtained catalyst composition was calcined at 500°C in nitrogen for 5 hours, and then the particle size was adjusted to 20 to 32 meshes, and 4 c.c. each was packed into two glass reaction tubes, and heated at 420°C for 10 hours.
Hydrogen was introduced for a period of time to perform reduction treatment. Steam is introduced into only one reaction tube (GR-A) to perform catalyst contact treatment, and the other reaction tube (GR-A) is
B) was used as is in the reaction. A reaction solution of m-cresol and methanol in a molar ratio of 1:8 was heated and vaporized at 250°C, and then poured into two reaction tubes whose internal temperature was adjusted to 390°C for 1 hour.
2.4g was introduced and a comparative reaction was carried out. The results are shown in Table 3.

【table】

Claims (1)

[Scope of Claims] 1. When producing an ortho-alkylated phenol compound by subjecting a phenol compound having at least one hydrogen atom at the ortho position to a gas-phase catalytic reaction with an alcohol, a magnesium oxide-containing catalyst is reduced, and then a magnesium oxide-containing catalyst is reduced; 1. A method for producing a selective orthoalkylated phenol compound, characterized in that it is used after being pretreated with water vapor. 2. When producing an ortho-alkylated phenol compound by subjecting a phenol compound having at least one or more hydrogen atom at the ortho position to a gas phase contact reaction with an alcohol, the manganese oxide-containing catalyst is reduced, and then pretreated with steam. 1. A method for producing a selective orthoalkylated phenol compound. 3. When producing an ortho-alkylated phenol compound by subjecting a phenol compound having at least one or more hydrogen atom at the ortho position to a vapor phase catalytic reaction with an alcohol, the chromium oxide-containing catalyst is reduced, and then pretreated with steam. 1. A method for producing a selective orthoalkylated phenol compound.