JP2007001952A - Method for producing oxime - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively produce an oxime in high yield by carrying out ammoxidation reaction of a ketone by using a catalyst having excellent properties and prepared advantageously in the cost. <P>SOLUTION: The method for producing the oxime involves using a fired product of a layered titanosilicate obtained by mixing a silicon compound, a titanium compound, water, a structure-regulating agent and hydrogen fluoride, and subjecting the resultant mixture to a hydrothermal synthetic reaction when producing the oxime by subjecting the ketone to the ammoxidation reaction with a peroxide and ammonia in the presence of the titanosilicate having an MWW structure. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing an oxime by an ammoximation reaction of a ketone.

  Oxime is useful as a raw material for amides or lactams. As one of the methods for producing oximes, a method is known in which a ketone is ammoximation-reacted using titanosilicate as a catalyst. For example, Patent Document 1 discloses that the ammoximation reaction is performed using titanosilicate [titanium silicalite (TS-1)] having an MFI structure as a catalyst. In Patent Document 2, a silicon compound, a boron compound, water and a structure-directing agent are mixed and heated, and the resulting borosilicate is deboronated by acid treatment, and then heated with a titanium compound and a structure-directing agent. It is disclosed that titanosilicate having an MWW structure is prepared by introducing titanium and then calcining, and using this as a catalyst, the ammoximation reaction is performed.

JP-A-62-59256 International Publication No. 03/0747421 Pamphlet

  However, the method disclosed in Patent Document 1 may not be satisfactory in terms of the conversion rate of ketone and the selectivity of oxime because the performance of the catalyst is not necessarily sufficient. Further, in the method disclosed in Patent Document 2, since a large amount of boron compound is used in the catalyst preparation step, it takes a lot of cost and labor to process a large amount of boron waste liquid, and the performance of the catalyst is not always sufficient.

  Accordingly, an object of the present invention is to provide a method capable of producing oxime at a high yield and at a low cost by carrying out the above ammoximation reaction using a catalyst that has excellent performance and can be advantageously prepared in terms of cost. Is to provide.

  As a result of intensive studies, the present inventors have found that the above object can be achieved by employing titanosilicate having an MWW structure prepared by a predetermined method as a catalyst for the above ammoximation reaction. It came to be completed.

  That is, the present invention is a method for producing an oxime by an ammoximation reaction of a ketone with a peroxide and ammonia in the presence of a titanosilicate having an MWW structure, the titanosilicate comprising a silicon compound, titanium A method for producing an oxime, which is prepared by mixing a compound, water, a structure-directing agent and hydrogen fluoride, subjecting to a hydrothermal synthesis reaction, and firing the obtained layered titanosilicate Is to provide.

  According to the present invention, by employing titanosilicate having an MWW structure prepared by a predetermined method as a catalyst for the ammoximation reaction, an oxime can be produced at a high yield and at a low cost.

  The catalyst used for the ammoximation reaction in the present invention is a crystalline titanosilicate having an MWW structure (hereinafter, the crystalline titanosilicate having an MWW structure may be referred to as Ti-MWW), where MWW and Is one of the structure codes of zeolite defined by the International Zeolite Association (IZA), like the MFI. Specific examples of the compound having an MWW structure include MCM-22, SSZ-25, ITQ-1, ERB-1, PSH-3, and the like.

  Further, titanosilicate includes titanium, silicon, and oxygen as elements constituting the skeleton, and the skeleton may be substantially composed only of titanium, silicon, and oxygen. It may further contain elements other than titanium, silicon, and oxygen, such as boron, aluminum, gallium, iron, and chromium. The titanosilicate may be used in the form of granules or pellets with or without a binder, or may be used by being supported on a carrier.

  The titanium content in the titanosilicate is usually 0.0001 or more, preferably 0.005 or more, expressed as an atomic ratio (Ti / Si) to silicon, and is usually 0.1 or less, preferably 0.00. 05 or less. In addition, when this titanosilicate contains elements other than titanium, silicon, and oxygen, the content of the element is usually 0.05 or less, preferably 0.02 or less, expressed as an atomic ratio with respect to silicon. Oxygen can be present corresponding to the content and oxidation number of each element other than oxygen. A typical composition of such a titanosilicate can be represented by the following general formula (I) based on silicon (= 1).

(In the formula, M represents at least one element other than silicon, titanium, and oxygen, n is the oxidation number of the element, x is 0.0001 to 0.1, and y is 0 to 0.05. .)
In the general formula (I), M is an element other than titanium, silicon, and oxygen, and examples thereof include boron, aluminum, gallium, iron, and chromium.

  In the present invention, Ti-MWW is prepared by mixing a silicon compound, a titanium compound, water, a structure-directing agent and hydrogen fluoride, subjecting it to a hydrothermal synthesis reaction, and firing the obtained layered titanosilicate. Use the same thing. This preparation method itself is described in “Sugimoto, Kure, Tsuji,“ Synthesis of MWW-type titanosilicate by the fluoride method and its catalytic properties ”, Abstract of the 33rd Petroleum and Petrochemical Conference, Petrochemical Society of Japan, 2003 Year, p. 77 ", which discloses that the Ti-MWW obtained by this preparation method is applied to a catalyst for epoxidation reaction of olefins such as 1-hexene and cyclohexene. In the present invention, Ti-MWW obtained by this preparation method is applied as a catalyst for the ammoximation reaction of a ketone.

  Hydrothermal synthesis refers to “synthetic and crystal growth methods of substances performed in the presence of high-temperature water, especially high-temperature and high-pressure water” (“Iwanami Physical and Chemical Dictionary”, 4th edition, Iwanami Shoten, 1987, p. Specifically, the above-mentioned raw materials are mixed, heated in an autoclave to a temperature of about 100 to 200 ° C. under a self-pressure, and stirred for several hours to several days.

  Examples of silicon compounds in the above raw materials include tetraalkyl orthosilicates such as tetraethyl orthosilicate and silica. Examples of titanium compounds include tetraalkyl orthosilicates such as tetra-n-butyl orthotitanate. Examples thereof include titanates, peroxytitanates such as tetra-n-butylammonium peroxytitanate, and titanium halides. In addition, piperidine, hexamethyleneimine, or the like is usually used as a structure-directing agent (template) for forming a layered structure. The use ratio of each of the above raw materials is based on silicon of silicon compound, and titanium compound is usually 0.0001 to 0.1 mole times as titanium, water is usually 3 to 30 mole times, and structure directing agent is usually used. 0.3-3 mole times, and hydrogen fluoride is usually 0.3-3 mole times.

  When a layered titanosilicate that is a precursor of Ti-MWW is obtained by a hydrothermal synthesis reaction, a boron compound such as boric acid is usually used in a relatively large amount, specifically for the formation of the structure. Although it is necessary to use an equimolar amount or more of the silicon compound, the use amount of the boron compound can be reduced to zero by using hydrogen fluoride. As hydrogen fluoride, an aqueous solution (hydrofluoric acid) is usually used.

  Specifically, the layer structure of the layered titanosilicate obtained by the hydrothermal synthesis reaction can be confirmed by the presence of a peak on the 001 plane to the 002 plane in the X-ray diffraction pattern [for example, the 33rd In addition to the abstracts of the Petroleum and Petrochemical Discussion Meeting, Chemistry Letters, 2000, p. 774-775; Catalyst, 2001, 43, p. 158-160; Chemical Communications, (UK), 2002, p. 1026-1027; Catalyst, 2002, 44, p. 468-470 etc.]. Then, by firing this layered titanosilicate at a temperature of about 200 to 700 ° C., structural transformation to Ti-MWW, specifically, formation of a three-dimensional crystal structure by interlayer dehydration condensation of the crystal sheet occurs, In the X-ray diffraction pattern, the peaks on the 001 plane to the 002 plane disappear (see the above-mentioned documents).

  Before or after calcination, it is preferable to perform an acid treatment, whereby even when a boron compound is used in a hydrothermal synthesis reaction, boron introduced into the titanosilicate skeleton can be removed, and catalytic activity is improved. This is advantageous. Further, even when no boron compound is used in the hydrothermal synthesis reaction, extra-framework titanium can be removed by acid treatment, which is advantageous in terms of catalytic activity. As the acid, for example, nitric acid or sulfuric acid is preferably used. The acid treatment is advantageously performed before calcination.

  Further, the layered titanosilicate is washed with water if necessary, dried and then subjected to firing. By performing this drying using a spray dryer, simultaneously with drying, particles having a particle diameter of about 1 to 1000 μm are obtained. Can be molded.

  By using Ti-MWW prepared by the so-called fluoride method described above as a catalyst, an oxime can be produced with high yield by reacting ketone with an peroxide and ammonia in the presence of this catalyst. it can. In this ammoximation reaction, the catalyst Ti-MWW is preferably suspended as a solid phase in the liquid phase of the reaction mixture, and the proportion is usually 0.1 to 10% by weight based on the liquid phase. Degree. In addition, for the purpose of suppressing a decrease in the catalytic activity of Ti-MWW, a silicon compound other than titanosilicate such as silica gel, silicic acid, crystalline silica and the like may coexist.

  The raw material ketone may be an aliphatic ketone, an alicyclic ketone, an aromatic ketone, or two or more of them as necessary. Specific examples of ketones include, for example, dialkyl ketones such as acetone, ethyl methyl ketone, and isobutyl methyl ketone; alkyl alkenyl ketones such as mesityl oxide; alkyl aryl ketones such as acetophenone; diaryl ketones such as benzophenone; Examples include cycloalkanones such as nonone, cyclohexanone, cyclooctanone and cyclododecanone; cycloalkenones such as cyclopentenone and cyclohexenone. Among these, cycloalkanone is a suitable subject of the present invention.

  In addition, the raw material ketone may be obtained by, for example, oxidation of alkane, may be obtained by oxidation (dehydrogenation) of secondary alcohol, It may be obtained by oxidation (dehydrogenation).

  Examples of the peroxide include hydrogen peroxide and organic peroxides such as t-butyl hydroperoxide, di-t-butyl peroxide, cumene hydroperoxide, and the like. Of these, hydrogen peroxide is preferably used. Hydrogen peroxide is usually produced by the so-called anthraquinone method and is generally marketed as an aqueous solution having a concentration of 10 to 70% by weight, and can be used. Hydrogen peroxide can also be produced by reacting hydrogen and oxygen in an organic solvent in the presence of a solid catalyst supporting metal palladium. When hydrogen peroxide is used in this method, the reaction mixture An organic solvent solution of hydrogen peroxide obtained by separating the catalyst from the catalyst may be used in place of the aqueous hydrogen peroxide solution.

  The usage-amount of a peroxide is 0.5-3 mol normally with respect to 1 mol of ketones, Preferably it is 0.5-1.5 mol. Examples of peroxides include phosphates such as sodium phosphate, polyphosphates such as sodium pyrophosphate and sodium tripolyphosphate, pyrophosphate, ascorbic acid, ethylenediaminetetraacetic acid, nitrotriacetic acid, aminotriacetic acid, Diethylenetriaminepentaacetic acid or the like may be added.

  Ammonia may be used in the form of gas, liquid, or water or an organic solvent solution. The amount of ammonia used is preferably adjusted so that the concentration of ammonia in the liquid phase of the reaction mixture is 1% by weight or more. Thus, by setting the ammonia concentration in the liquid phase of the reaction mixture to a predetermined value or more, it is possible to increase the conversion rate of the raw material ketone and the selectivity of the target oxime, and consequently the yield of the target oxime. Can be increased. The ammonia concentration is preferably 1.5% by weight or more, and usually 10% by weight or less, preferably 5% by weight or less. In addition, the standard of the usage-amount of ammonia is 1 mol or more normally with respect to 1 mol of ketone, More preferably, it is 1.5 mol or more.

  The ammoximation reaction may be performed in a solvent. Examples of the reaction solvent include aromatic compounds such as benzene and toluene, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, Examples thereof include alcohols such as s-butyl alcohol, t-butyl alcohol, and t-amyl alcohol, and water. Of these, alcohol and water are preferable, and a mixed solvent of alcohol and water is particularly preferably used.

  The ammoximation reaction may be carried out batchwise or continuously, but by supplying the ketone, peroxide and ammonia into the reaction system, the reaction mixture is withdrawn from the reaction system, It is desirable to perform it continuously from the viewpoint of productivity and operability.

  The batch reaction may be performed, for example, by adding a ketone, ammonia, a catalyst, and a solvent to a reactor, and supplying a peroxide to the reactor with stirring, or by adding a ketone, a catalyst, and a solvent to the reactor. It may be carried out by supplying peroxide and ammonia into this under stirring, or by adding a catalyst and solvent into the reactor and supplying ketone, peroxide and ammonia into this under stirring. You may go.

  In the continuous reaction, for example, a reaction mixture in which a catalyst is suspended is present in the reactor, and a ketone, peroxide, ammonia and a solvent are supplied to the reaction mixture through a filter or the like from the reactor. It can be suitably carried out by extracting the liquid phase of the reaction mixture. The reactor is preferably glass-lined or stainless steel from the viewpoint of preventing decomposition of peroxide. In particular, in the oxime production method of the present invention, the oxime can be produced continuously for a long period of time by performing a continuous reaction using the above-described predetermined Ti-MWW, so that productivity is improved.

  The reaction temperature of the ammoximation reaction is usually 50 to 120 ° C, preferably 70 to 100 ° C. The reaction pressure may be normal pressure, but in order to facilitate the dissolution of ammonia in the liquid phase of the reaction mixture, the absolute pressure is usually 0.2 to 1 MPa, preferably 0.2 to 0.5 MPa. In this case, the pressure may be adjusted using an inert gas such as nitrogen or helium.

  The post-treatment operation of the obtained reaction mixture is appropriately selected. For example, after separating the catalyst from the reaction mixture by filtration or decantation, the liquid phase is subjected to distillation to separate the oxime. it can.

  Examples of the present invention will be described below, but the present invention is not limited thereto.

(Preparation of catalyst)
In a beaker, 32 g of pure water, 17 g of hexamethyleneimine, and 1.5 g of tetra-n-butyl orthotitanate were added, and the mixture was hydrolyzed by stirring at room temperature in an air atmosphere. Stir until. In the obtained aqueous solution, 10 g of fumed silica ("CAB-O-SIL M-7D" manufactured by CABOT) and a silicate having an MWW structure as a seed crystal (having an MWW structure according to the method described in Patent Document 2) (Prepared by deboronating borosilicate) 0.4 g was added and stirred for 30 minutes, and then 47 wt% hydrofluoric acid 7.1 g was added and stirred for another 30 minutes. Next, the mixture was transferred to an autoclave, and the autoclave was sealed. Then, the mixture was heated to 170 ° C. with stirring, and heated at the same temperature for 10 days for hydrothermal synthesis. The obtained suspension was filtered, and the filter residue was washed until the pH of the washing solution became 10 or less, and then dried at room temperature to obtain 10 g of a white powder.

  10 g of this white powder was heated to reflux in 300 mL of 2M nitric acid for 20 hours and then filtered, and the residue was washed until the pH of the washing solution was 5 or higher. The obtained white powder was dried and then calcined at 530 ° C. for 10 hours to obtain Ti-MWW with Ti / Si (atomic ratio) = 0.02.

(Ammoximation reaction)
A 1 L autoclave was used as a reactor, and in this, 13.4 g / hour of cyclohexanone, 52 g / hour of hydrous t-butyl alcohol (water 12% by weight), and 8.9 g of 60% by weight hydrogen peroxide water were contained. By pulling out the liquid phase of the reaction mixture from the reactor through a filter while feeding at a rate of / hour and supplying ammonia to be present at a concentration of 2% by weight in the liquid phase of the reaction mixture, The continuous reaction was performed under the conditions of a temperature of 85 ° C., a pressure of 0.35 MPa (absolute pressure), and a residence time of 6 hours. During this time, the Ti-MWW obtained above was present in the reaction mixture in the reactor at a ratio of 0.2% by weight to the liquid phase.

  As a result of analyzing the liquid phase extracted 5.5 hours after the start of the reaction, the conversion of cyclohexanone was 99.3%, the selectivity of cyclohexanone oxime was 99.5%, and the yield of cyclohexanone oxime was 98.8%. Met. As a result of analyzing the liquid phase extracted after 102 hours from the start of the reaction, the conversion of cyclohexanone was 97.0%, the selectivity of cyclohexanone oxime was 99.2%, and the yield of cyclohexanone oxime was 96.2%. Met. Since the oxygen concentration in the autoclave rapidly increased 121 hours after the start of the reaction, the reaction was terminated.

[Comparative Example 1]
(Preparation of catalyst)
In a beaker, 351 g of pure water, 119 g of piperidine, and 7 g of tetra-n-butyl orthotitanate were added and stirred at room temperature in an air atmosphere for hydrolysis. Then, 63 g of boric acid was added and stirred until uniform. 63 g of fumed silica (“CAB-O-SIL M-7D” manufactured by CABOT) was added to the obtained aqueous solution, and the mixture was further stirred for 1.5 hours. The mixture was transferred to an autoclave and sealed, and the mixture was heated to 170 ° C. with stirring, and heated at the same temperature for 7 days for hydrothermal synthesis. The obtained suspension was filtered, and the residue was washed until the pH of the washing became 9 or less, and then dried at 110 ° C. to obtain 24 g of a white powder.

  18 g was collected from this white powder, heated and refluxed in 350 mL of 2M nitric acid for 18 hours, filtered, and the residue was washed until the pH of the washing solution became 5 or higher. The obtained white powder was dried at 110 ° C. and then calcined at 530 ° C. for 10 hours to obtain Ti-MWW with Ti / Si (atomic ratio) = 0.03.

(Ammoximation reaction)
The ammoximation reaction was performed in the same manner as in Example 1 using the Ti-MWW obtained above as a catalyst. As a result of analyzing the liquid phase extracted 5.5 hours after the start of the reaction, the conversion of cyclohexanone was 98.9%, the selectivity of cyclohexanone oxime was 99.6%, and the yield of cyclohexanone oxime was 98.5%. Met. As a result of analyzing the liquid phase extracted 44 hours after the start of the reaction, the conversion of cyclohexanone was 79.4%, the selectivity of cyclohexanone oxime was 43.1%, and the yield of cyclohexanone oxime was 34.2%. Met. Since the oxygen concentration in the autoclave rapidly increased 51 hours after the start of the reaction, the reaction was terminated.

[Comparative Example 2]
An ammoximation reaction was carried out in the same manner as in Example 1 using TS-1 (commercial product), which is a titanosilicate having an MFI structure, as a catalyst. Three hours after the start of the reaction, the oxygen concentration in the autoclave rapidly increased, so the reaction was terminated.

Claims (8)

  A method for producing an oxime by an ammoximation reaction of a ketone with a peroxide and ammonia in the presence of a titanosilicate having an MWW structure, wherein the titanosilicate comprises a silicon compound, a titanium compound, water, a structure-defining formula A method for producing an oxime, which is prepared by mixing an agent and hydrogen fluoride, subjecting to a hydrothermal synthesis reaction, and firing the obtained layered titanosilicate.   The method for producing an oxime according to claim 1, wherein the ammonia concentration in the liquid phase of the reaction mixture in the ammoximation reaction is 1 wt% or more.   The method for producing an oxime according to claim 1 or 2, wherein the ammoximation reaction is carried out continuously by extracting a reaction mixture from the reaction system while supplying ketone, peroxide and ammonia into the reaction system.   The method for producing an oxime according to any one of claims 1 to 3, wherein the ammoximation reaction is carried out in a mixed solvent of alcohol and water.   The method for producing an oxime according to any one of claims 1 to 4, wherein the ammoximation reaction is performed under a pressure of 0.2 to 1 MPa.   The method for producing an oxime according to any one of claims 1 to 5, wherein the ketone is a cycloalkanone.   The method for producing an oxime according to any one of claims 1 to 6, wherein the peroxide is hydrogen peroxide. The method for producing an oxime according to any one of claims 1 to 7, wherein the titanosilicate is present in the liquid phase of the reaction mixture in the ammoximation reaction in an amount of 0.1 to 10% by weight based on the liquid phase.