JPS6232177B2 - - Google Patents

Description

Detailed Description of the Invention The present invention relates to a method for producing cyclohexylphenol using phenol as a starting material. More specifically, the present invention relates to a method for producing cyclohexylphenol using phenol as a starting material. The present invention relates to a method for producing cyclohexylphenol by hydroalkylation in the presence of. The cyclohexylphenol produced by the present invention is used as an antioxidant and surfactant for synthetic resins, rubber, fatty oils, soaps, etc. Furthermore, the phenyl phenol obtained by dehydrogenating cyclohexylphenol is Among phenols, p-phenylphenol is a dye carrier for synthetic fibers.
antioxidants, fungicides, insecticides, and synthetic resins;
In particular, it is a raw material for pressure-sensitive paper resins, and o-phenylphenol and its soda salt are useful as bactericides, preservatives, antifungal agents, dye carriers for synthetic fibers, plasticizers, stabilizers, etc. It is. Furthermore, one of the conventionally known methods for producing cyclohexylphenol is a method for obtaining cyclohexylphenol by dehydrogenating cyclohexenylcyclohexanone obtained by aldol condensation of cyclohexanone. However, in this method, the selectivity and conversion rate of cyclohexylphenol are not satisfactory. On the other hand, as a method for producing cycloalkyl aromatic compounds from aromatic compounds by hydroalkylation, as described in U.S. Pat. It is known that a catalyst consisting of Ni and Ni is effective for hydroalkylation. However, in general, hydroalkylation of aromatic compounds often produces various by-products, so the selectivity of the target compound in hydroalkylation is important, but in the above patent, the selectivity of the target compound is important. The selectivity has not been sufficiently studied, and it is not possible to obtain cyclohexylphenol from phenol by hydroalkylation in a satisfactory yield using the catalyst described in the above-mentioned US patent. In general, in the reaction of producing a cycloalkyl aromatic compound by hydroalkylation of the same or different aromatic compounds, one aromatic compound is hydrogenated to form an alicyclic compound, which is then converted into another same or different aromatic compound. Since cyclohexylphenol is alkylated into a cycloalkyl aromatic compound, it is considered easy to use benzene and phenol as raw materials to produce cyclohexylphenol from an aromatic compound by hydroalkylation. but,
Alkylation by cyclohexene produced by the hydrogenation of benzene does not proceed because the alkylation active part of the catalyst is more adsorbed with phenol, and the cyclohexene produced is further converted to hydrogen by the hydrogenation active part of the catalyst. The selectivity of the cyclohexylphenol produced is not sufficient. That is, as a method for producing cyclohexylphenol from an aromatic compound by hydroalkylation, it is conceivable to use phenol as a starting material. However, in the hydroalkylation of phenol, phenol is first hydrogenated to form cyclohexanol, which is then alkylated to phenol, presumably to form cyclohexylphenol. In other words, in the end, alcohol alkylates to phenol, but in this case, water is inevitably produced as a by-product, and this by-produced water has a negative effect on the alkylation, and in turn, the desired cyclohexyl This reduces the selectivity of phenol. However, in the above-mentioned US patent, the selectivity of cyclohexylphenol is insufficient, and the effect of such by-product water is completely ignored, so it is not an adequate method for producing cyclohexylphenol from phenol. I can't say that. As a result of intensive research into a method for producing cyclohexylphenol by hydroalkylation of phenol using phenol as an alkylating agent and an alkylated agent, the present inventors discovered that nickel, which has a hydrogenation function, and nickel, which has an alkylation function, The present invention was completed based on the discovery that, in combination with silica and alumina, the composition of silica and alumina, which particularly contributes to alkylation, has an important meaning. That is, the present invention uses a catalyst made of nickel and silica/alumina with an alumina content of 30 to 60%, and hydroalkylates phenol in the presence of hydrogen as an alkylating agent and an agent to be alkylated to produce cyclohexylphenol. It is about the method. The above catalyst system is constructed by an appropriate method according to a conventional method, but nickel is supported on silica/alumina with an alumina content of 30 to 60%, or nickel is supported on silica and the above silica/alumina is used. It is preferable to mix them before use. Nickel is added as a component having hydrogenation activity to phenol. The alumina content in silica-alumina is particularly important and should be between 30 and 60%. If silica/alumina is used outside this range, the selectivity of cyclohexylphenol, which is the object of the present invention, will decrease, which is not preferable. 25% alumina content as described in US Pat. No. 3,317,611
Therefore, the selectivity of cyclohexylphenol is low. The amount of nickel supported is preferably 0.01% to 20% for each of the silica/alumina and silica carriers, and if it is less than that, the hydrogenation reaction that is carried out continuously in hydroalkylation and the hydrogenation reaction in alkylation. If the amount is too high, only the hydrogenation reaction will proceed, which is not preferable. In the mixed catalyst, the mixing ratio of the silica carrier supporting nickel and silica/alumina is preferably 10 to 100 parts by weight of silica/alumina to 1 part silica carrier. The silica/alumina used in the present invention is a synthetic product synthesized from water glass, sodium aluminate or aluminum sulfate, a natural product called a clay catalyst including acid clay and its acid-treated activated clay, or It can be obtained from a semi-synthetic product by mixing the two, and the silica carrier used in the mixed catalyst can be synthesized from water glass or the like. A method for preparing synthetic silica/alumina that can be used in the present invention is, for example, a deposition method. In this method, water glass is dissolved in distilled water, and the PH
Silica hydrogel is produced when an inorganic acid such as hydrochloric acid or sulfuric acid is stirred and mixed so that the ratio is about 3 to 8. After washing this silica hydrogel, an aqueous solution of an aluminum salt such as aluminum chloride or aluminum sulfate is added so as to have a predetermined alumina content. Ten
Add the mixture while stirring until it reaches the desired temperature, then leave it as it is overnight to ripen. The aged and precipitated gel is washed, filtered, dried at an appropriate temperature to make the particle size uniform, and then stored in a desiccator.
Bake at the specified temperature before use. The silica carrier that can be used in the mixed catalyst of the present invention is prepared from water glass by a deposition method in the same manner as the silica-alumina described above. When the synthetic silica/alumina prepared as described above, natural silica/alumina such as activated clay, or synthetic silica carrier used in the present invention is subjected to the reaction, it is carried out in air for 2 to 6 hours, for example, about 4 hours.
Calcinate at 600°C to 800°C, preferably about 700°C, and support nickel as it is or by an appropriate method,
In this case, further calcination is performed in the same manner as above, and then hydrogen is used.
It is preferable to reduce at 400 to 450°C for 2 to 5 hours, for example about 3.5 hours, and then immediately use the reaction. As a method for supporting nickel, silica/alumina or silica calcined as described above is stirred and mixed in an aqueous solution of a nitrate such as nickel nitrate, and water is evaporated. It is then dried, fired, and reduced. When using a mixed catalyst, silica/alumina and metal-supported silica can be stirred and mixed at a predetermined ratio using an appropriate method, such as a glass container, prior to the reaction, and used as a mixed catalyst for the reaction. In the production method of the present invention, the reaction temperature is 25℃ ~
The temperature is 300°C, preferably 150-250°C. The pressure of hydrogen is 1Kg/ ^cm2 to 80Kg/ ^cm2 , preferably 40Kg/ ^cm2 to 70
Kg/ ^cm2 . This hydrogen pressure is higher than the pressure that makes the phenol a liquid phase at the above reaction temperature,
Also, if the amount of hydrogen required for hydroalkylation is supplied, an inert gas such as nitrogen gas can be mixed with the hydrogen. According to the production method of the present invention, cyclohexylphenol can be obtained in sufficient yield due to the excellent selectivity of cyclohexylphenol, and among some by-products, cyclohexylcyclohexanone and cyclohexanone are easily dehydrated. The former can be converted into the target compound, cyclohexylphenol, and the latter can be converted into the raw material, phenol, which is extremely advantageous in terms of by-product utilization. Furthermore, in order to avoid the effect of by-product water as mentioned above, it is possible to minimize the conversion rate in the production method of the present invention to the extent possible, or to carry out production using a pressurized continuous reaction apparatus as described below. good. The production method of the present invention uses a catalyst having the above composition range,
Cyclohexylphenol is produced from phenol in good yield, and the reaction method can be a batch or continuous reaction apparatus. In the case of production using a batch device, the catalyst and phenol are placed in a batch device such as an autoclave, replaced with an inert gas such as nitrogen gas, pressurized with hydrogen, and heated and stirred at a predetermined reaction temperature. to carry out the reaction.
After the reaction is completed, the catalyst is removed from the reaction solution by cooling to room temperature, and the target cyclohexylphenol is separated from the reaction product by a conventional separation method such as fractional distillation or recrystallization. Furthermore, unreacted phenol is recycled, and the by-produced cyclohexylcyclohexanone and cyclohexanone are each dehydrogenated by an appropriate dehydrogenation catalyst, the former being converted to cyclohexylphenol and the latter to phenol, and the phenol is further recycled for reaction. can be provided. In the case of production using a continuous apparatus, the catalyst bed may be a fixed bed or a fluidized bed, and it is also possible to use the catalyst in the form of a slurry. In the case of a fixed bed, phenol is passed through up flow or down flow, and in the case of a fluidized bed or slurry catalyst, it is passed continuously under pressure of hydrogen by countercurrent or countercurrent to carry out the reaction. By doing so, cyclohexylphenol can be obtained. After the reaction is completed, cyclohexylphenol and other by-products are separated and recovered in the same manner as in the batch apparatus. As mentioned above, in the hydroalkylation of phenol, the by-product water has a negative effect on the selectivity of cyclohexylphenol, but if production is carried out using this pressurized continuous equipment, the by-product water can be continuously produced. This is a preferred method because the influence of water is minimized since it is taken out from the catalyst layer. The present invention will be specifically explained below using Examples and Comparative Examples. Example 1 50 g of No. 3 water glass was dissolved in 300 c.c. of distilled water, and 57 c.c. of 2.5N hydrochloric acid was mixed with stirring. At this time, the pH of the liquid was approximately 4 using PH test paper. After washing the generated silica hydrogel with distilled water,
2 g of AlCl ₃ .6H ₂ O was added to a solution of 125 c.c. of distilled water. Further, while stirring this liquid, 28%
of ammonia water was gradually added. When all the ammonia water was added, the pH of the liquid was approximately 9. After this was left to ripen overnight, filtering and washing were repeated until the absence of chloride ions in the filtrate was confirmed using a silver nitrate solution. Next, after drying at 120°C for a day and night, the particle size was adjusted to 40 to 110 mesh.
The alumina content of the prepared silica-alumina was confirmed by atomic absorption spectrometry to be 42%. The silica/alumina prepared as above is
It was fired in air at 700°C for 4 hours. Next, silica
The water in which alumina was stirred and mixed with a nickel nitrate aqueous solution was evaporated, and the Ni
% was supported. The obtained catalyst was dried at 120°C for a day and night, further calcined in air at 700°C for 2 hours, reduced with hydrogen at 430°C for 3.5 hours, and immediately used for the reaction. Phenol in a 50ml autoclave with stirrer
0.09mol of the above Ni-supported silica/alumina
After charging 1.4g and replacing the air with nitrogen, hydrogen was introduced. Next, while maintaining the hydrogen pressure at a constant pressure of 60 kg/cm ² , the autoclave was heated to 220° C. and stirred for 70 minutes to hydroalkylate the phenol. After the reaction was completed, the reaction product was cooled to room temperature, and the catalyst was filtered and analyzed by gas chromatography, infrared spectroscopy, and mass spectroscopy, and the conversion rate and selectivity of cyclohexylphenol and byproducts were calculated from the results. The results in Table 1 show that cyclohexylphenol was obtained with sufficient selectivity. Moreover, most of the by-products were cyclohexylcyclohexanone and cyclohexanone. Examples 2 and 3 5% Ni supported and alumina content of Example 2
Silica-alumina of 30% in Example 3 and 60% in Example 3 was prepared in the same manner as in Example 1, and phenol was hydroalkylated. Table 1 shows the results.
It was shown to. Combining these results with Example 1, it can be seen that silica-alumina with an alumina content of 30 to 60% has an excellent selectivity for cyclohexylphenol. Example 4 Commercially available silica carrier (Fuji-Davison Chemical)
Ltd., RD type), and the grain size was adjusted to 40 to 110 mesh, and then fired at 700°C for 4 hours. Next, 5% Ni was supported on the silica using a nickel nitrate aqueous solution in the same manner as in Example 1, dried at 120°C for a day and night, calcined in air at 700°C for 2 hours, and further reduced with hydrogen at 430°C for 3.5 hours. did. Further, silica-alumina having an alumina content of 42% was prepared and fired in the same manner as in Example 1. Next, 0.3 g of the Ni-supported silica carrier prepared in this way and 1.1 g of silica/alumina (weight ratio of silica:silica/alumina≒1:37) were immediately mixed in a glass container, and then the mixture as in Example 1 was mixed. Phenol was similarly hydroalkylated. As shown in Table 1, it was confirmed that cyclohexylphenol was synthesized with sufficient selectivity using a silica carrier supporting Ni and a mixed catalyst of silica/alumina with an alumina content of 42%. Comparative Examples 1 and 2 Phenol was reacted in the same manner as in Example 1 using a catalyst in which the alumina content of the catalyst in Example 1 was 25% in Comparative Example 1 and 70% in Comparative Example 2. The results shown in Table 1 show that the selectivity of cyclohexylphenol is insufficient and is not satisfactory as a method for producing cyclohexylphenol from phenol by hydroalkylation. Comparative Example 3 An equimolar mixture of benzene and phenol was similarly hydroalkylated using the same catalyst as in Example 1. Table 1 shows that the process for producing cyclohexylphenol from benzene and phenol by hydroalkylation does not give satisfactory results. As explained above, the production method of the present invention is a production method for producing cyclohexylphenol, which is a useful intermediate in the chemical industry, from phenol with a satisfactory selectivity. It also has excellent features such as great advantages. 【table】

Claims (1)

[Claims] 1. Nickel and alumina content of 30 to 60 wt%
A production method for producing cyclohexylphenol by hydroalkylating phenol in the presence of hydrogen as an alkylating agent and an agent to be alkylated using a catalyst made of silica alumina. 2. The manufacturing method according to claim 1, wherein nickel is supported on the silica alumina having an alumina content of 30 to 60 wt%. 3. Claim 1, characterized in that nickel is supported on a silica carrier and mixed with the silica alumina having an alumina content of 30 to 60 wt%.
Manufacturing method described in section.