JP4577003B2 - Oxime production method - Google Patents

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, JP-A-62-59256 (Patent Document 1) discloses that the above ammoximation reaction is carried out using titanosilicate (titanium silicalite TS-1) having an MFI structure as a catalyst. Yes. In addition, International Publication No. 03/074421 (Patent Document 2) discloses that the ammoximation reaction is performed using titanosilicate having an MWW structure as a catalyst.

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 the ketone and the selectivity of the oxime because the performance of the catalyst is not sufficient. Further, in the method disclosed in Patent Document 2, the catalyst preparation process is long and complicated, so that it may not be satisfactory in terms of cost. 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 obtained a titanosilicate having a specific X-ray diffraction pattern that can be generated as a precursor when preparing a titanosilicate having an MWW structure as shown in Patent Document 2. The inventors have found that the above object can be achieved by adopting the catalyst for the ammoximation reaction, and have completed the present invention.

  That is, the present invention provides an oxime wherein a ketone is ammoximation-reacted with peroxide and ammonia in the presence of titanosilicate showing an X-ray diffraction pattern having a peak at the following position in lattice spacing display. The manufacturing method of this is provided.

Lattice spacing d (Å):
13.2 ± 0.6,
12.3 ± 0.3,
11.0 ± 0.3,
9.0 ± 0.3,
6.8 ± 0.3,
3.9 ± 0.2,
3.5 ± 0.1,
3.4 ± 0.1.

  According to the present invention, an oxime can be produced at a high yield and at a low cost by an ammoximation reaction of a ketone.

  The titanosilicate used as a catalyst for the ammoximation reaction in the present invention is a crystalline titanosilicate containing titanium, silicon, and oxygen as elements constituting the skeleton, and the skeleton is composed substantially only of titanium, silicon, and oxygen. The element constituting the skeleton may further contain elements other than titanium, silicon, and oxygen, such as boron, aluminum, gallium, iron, and chromium. In addition, 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.

  In the titanosilicate, the titanium content is preferably 0.0001 or more, more preferably 0.005 or more, and preferably 0.1 or less, expressed as an atomic ratio (Ti / Si) to silicon. More preferably, it is 0.05 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. Moreover, oxygen can exist corresponding to the content and oxidation number of each element other than oxygen. A typical composition of such titanosilicate can be expressed by the following formula with silicon as the reference (= 1).

SiO ₂ · xTiO ₂ · yM ⁿ O _{n / 2}

(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 addition, the titanosilicate used in the present invention has a peak at the following position in the X-ray diffraction pattern in the lattice spacing d [Å (angstrom)] display. The titanosilicate showing such a specific X-ray diffraction pattern is excellent in terms of activity and selectivity as a catalyst in a ketone ammoximation reaction, that is, in terms of conversion of ketone and selectivity of oxime.

Lattice spacing d (Å):
13.2 ± 0.6,
12.3 ± 0.3,
11.0 ± 0.3,
9.0 ± 0.3,
6.8 ± 0.3,
3.9 ± 0.2,
3.5 ± 0.1,
3.4 ± 0.1.

  This X-ray diffraction pattern can be measured by a general X-ray diffractometer using copper K-alpha radiation. That is, when copper K-alpha radiation is used, the peak at d = 13.2 ± 0.6Å is 2θ (θ is the Bragg angle; the same applies hereinafter) = around 6.7 ° (6.4-7.0 °) The peak at d = 12.3 ± 0.3Å is around 2θ = 7.2 ° (7.0 to 7.4 °), and the peak at d = 11.0 ± 0.3Å is around 2θ = 8.0 ° (7.8 to 8.3 °), the peak of d = 9.0 ± 0.3 ° is around 2θ = 9.8 ° (9.5 to 10.2 °), d = 6.8 ± 0.3 ° The peak at 2θ = 13.0 ° (12.5 to 13.6 °), and the peak at d = 3.9 ± 0.2 ° is near 2θ = 22.8 ° (21.6-24.0 °). The peak at d = 3.5 ± 0.1Å is around 2θ = 25.4 ° (24.7-26.2 °), and the peak at d = 3.4 ± 0.1Å is around 2θ = 26.2 ° (25.4 to 27.0 °), respectively

  In this X-ray diffraction pattern, the presence of peaks other than those described above is arbitrary. Moreover, although each said peak normally shows a maximum value in the lattice space | interval, it may overlap with another peak and may be detected as a shoulder peak.

  The titanosilicate showing the specific X-ray diffraction pattern as described above can be obtained as a precursor when preparing a titanosilicate having an MWW structure (hereinafter sometimes referred to as Ti-MWW). That is, for example, Chemistry Letters, 2000, p. 774-775, Japanese Patent Application Laid-Open No. 2002-102709, etc., as a preparation method of Ti-MWW by a direct synthesis method, a structure directing agent (template), a titanium compound, a boron compound, a silicon compound, and water are mixed and heated. After that, it is described that an acid treatment is carried out if necessary, and the obtained precursor is fired to prepare Ti-MWW. This precursor corresponds to the specific titanosilicate used in the present invention. Is. In addition, Chemical Communications (UK), 2002, p. 1026-1027, Japanese Patent Application Laid-Open No. 2003-327425, International Publication No. 03/074421 pamphlet (Patent Document 2), etc., as a preparation method of Ti-MWW by a post-synthesis method, a structure-directing agent, a boron compound, silicon After mixing and heating the compound and water, calcination is carried out if necessary, and then acid treatment is performed to obtain a silicate once. This silicate is mixed with a structure-directing agent, a titanium compound and water, and then heated. Although it is described that Ti-MWW is prepared by calcination with acid and calcining the obtained precursor, this precursor corresponds to the above-mentioned specific titanosilicate used in the present invention. Thus, the titanosilicate (Ti-MWW precursor) used in the present invention is obtained as a precursor before firing when preparing Ti-MWW, and compared with Ti-MWW, Equipment, energy, time, etc. required can be reduced and can be prepared at low cost. Therefore, the ammoximation reaction using the Ti-MWW precursor according to the present invention as a catalyst is advantageous in terms of the preparation cost of the catalyst as compared with the ammoximation reaction using Ti-MWW as a catalyst as disclosed in Patent Document 2. Yes, the oxime can be produced at a lower cost.

  Here, examples of the structure-directing agent used in the above preparation method include piperidine and hexamethyleneimine, and examples of the titanium compound include tetraalkyl orthotitanates such as tetra-n-butyl orthotitanate, and titanic acid peroxide. Examples thereof include titanates such as tetrapropylammonium and titanium halides. Examples of boron compounds include boric acid. Examples of silicon compounds include tetraalkyl orthosilicates such as tetraethyl orthosilicate and fumed silica. Etc.

  Moreover, the heating conditions of each mixture in the said preparation method are heating temperature normally 100-200 degreeC, heating time is normally 2-240 hours, and the temperature increase rate to heating temperature is 0.01-2 degreeC normally. / Min. As this heating method, a hydrothermal synthesis method carried out under the pressure of the mixture is generally employed, and may be a batch method or a distribution method, and has an MWW structure during this heating. Zeolite or the like may be added as a seed crystal, or hydrofluoric acid may be added.

  Moreover, in the said preparation method, an acid treatment is performed in order to remove a structure directing agent, boron, extra-framework titanium, etc., and nitric acid or a sulfuric acid is preferably used for this acid.

  The Ti-MWW precursor obtained by the above preparation method is used after being washed with water if necessary and then dried. As this drying method, a method of heating with a dryer, a method of blowing heated gas, or a spray dryer is used. Methods and the like. Among them, the method using a spray dryer is preferable because it can be formed into particles having a particle diameter of about 1 to 1000 μm simultaneously with drying.

  If the drying temperature is too high, energy costs will be required, and it will be in the temperature range of calcination where structural transformation from Ti-MWW precursor to Ti-MWW takes place, while if it is too low, drying will take time. Therefore, the production efficiency will be lowered, so it will be adjusted accordingly. In the aforementioned Japanese Patent Application Laid-Open No. 2002-102709, Japanese Patent Application Laid-Open No. 2003-327425, and the like, the firing temperature for performing the structural conversion from the Ti-MWW precursor to Ti-MWW is preferably 200 to 700 ° C. It is preferable that the drying temperature be less than 200 ° C. for a lower energy cost, since it is preferably described as 300 to 650 ° C., and most preferably 400 to 600 ° C. In this respect, it is usually 20 ° C. or higher.

  The structural conversion from Ti-MWW precursor to Ti-MWW by firing is specifically due to dehydration condensation between layers of Ti-MWW precursor, which is a layered titanosilicate, and crystallization to MWW structure occurs. However, this can be confirmed by a change in the X-ray diffraction pattern. That is, FIG. 1 is a chart of an X-ray diffraction pattern of the Ti-MWW precursor prepared and used in Example 1 described later by copper K-alpha radiation, and FIG. 2 shows this Ti-MWW precursor at 530 ° C. 6 is a chart of an X-ray diffraction pattern of Ti-MWW obtained by firing for 6 hours with copper K-alpha radiation. As a result of structural conversion from a Ti-MWW precursor to Ti-MWW by this firing, It can be confirmed that the lattice spacing d = 13.2 ± 0.6 mm (around 2θ = 6.7 °), which is one of the peaks defined in the invention, disappears. This peak is shown, for example, in Catalyst, 2001, 43, p. As described in 158, it is a peak derived from the 002 plane, and is unique to the layer structure of the Ti-MWW precursor in terms of contrast with Ti-MWW.

  By using the titanosilicate of the Ti-MWW precursor described above as a catalyst and carrying out an ammoximation reaction of a ketone with peroxide and ammonia in the presence of this catalyst, an oxime can be produced with high yield. In this ammoximation reaction, the catalyst titanosilicate is preferably suspended in the liquid phase of the reaction mixture and present as a solid phase, and the ratio is appropriately adjusted in consideration of catalyst activity, dispersibility, and the like. However, it is usually about 0.1 to 10% by weight with respect to the liquid phase. In addition, for the purpose of suppressing a decrease in the catalytic activity of titanosilicate, a silicon compound other than titanosilicate such as silica gel, silicic acid, or crystalline silica 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: 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; cyclopentanone And cycloalkanones such as cyclohexanone, cyclooctanone and cyclododecanone; cycloalkenones such as cyclopentenone and cyclohexenone. Among them, cycloalkanone is a suitable subject of the present invention.

  The raw material ketone may be, for example, one obtained by oxidation of alkane, one obtained by oxidation (dehydrogenation) of secondary alcohol, or hydration and oxidation of alkene ( It may be obtained by dehydrogenation.

  Examples of the peroxide include hydrogen peroxide and organic peroxides such as t-butyl hydroperoxide, di-t-butyl peroxide and cumene hydroperoxide. 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, and the liquid phase of the reaction mixture is withdrawn from the reaction system while supplying ketone, peroxide and ammonia into the reaction system. Therefore, it is desirable to carry out in a continuous manner 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, the reaction mixture in which the catalyst is suspended is present in the reactor, and the ketone, peroxide, ammonia and the solvent are supplied to the reaction mixture through the filter through the reactor. It can be suitably carried out by extracting the liquid phase of the mixture. The reactor is preferably glass-lined or stainless steel from the viewpoint of preventing decomposition of peroxide.

  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.

Example 1
(Preparation of catalyst)
In an autoclave, piperidine 9.1 kg, pure water 25.6 kg, boric acid 6.2 kg, tetra-n-butyl orthotitanate 0.54 kg, and fumed silica ("CAB-O-SIL M-7D" manufactured by CABOT) ) 4.5 kg was added and a gel was prepared by stirring at room temperature in an air atmosphere and aged for 1.5 hours. The autoclave was sealed, heated to 170 ° C. over 10 hours with stirring, and then kept at the same temperature for 168 hours to carry out hydrothermal synthesis to obtain a suspension. This suspension was filtered, and the residue was washed with water until the pH of the washing solution was around 10, and then dried at 50 ° C. to obtain a white powder still containing water.

  To 350 g of this water-containing white powder, 3.5 L of 13 wt% nitric acid was added and refluxed for 20 hours. Next, the mixture was filtered, and the residue was washed with water until the washing liquid became near neutral, and then sufficiently dried at 50 ° C., and titanosilicate (Ti-MWW precursor) with Ti / Si (atomic ratio) = 0.139. 98 g was obtained as a white powder. As a result of measuring the X-ray diffraction pattern of this titanosilicate with an X-ray diffractometer using copper K-alpha radiation, the peaks shown in the following table were observed as shown in FIG.

(Ammoximation reaction)
An ammoximation reaction was performed using the titanosilicate obtained above as a catalyst. That is, an autoclave having a capacity of 1 liter 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 60% by weight of hydrogen peroxide water were contained. The liquid phase of the reaction mixture is withdrawn from the reactor through a filter while supplying at a rate of 8.9 g / hr and ammonia is present at a concentration of 2% by weight in the liquid phase of the reaction mixture. Thus, a 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 titanosilicate was present in the reaction mixture in the reactor at a ratio of 0.2% by weight with respect to the liquid phase.

  As a result of analyzing the liquid phase extracted 1.5 hours after the start of the reaction, the conversion of cyclohexanone was 95.7%, the selectivity of cyclohexanone oxime was 99.0%, and the yield of cyclohexanone oxime was 94.7%. Met. As a result of analyzing the liquid phase extracted after 52 hours from the start of the reaction, the conversion of cyclohexanone was 99.8%, the selectivity of cyclohexanone oxime was 99.4%, and the yield of cyclohexanone oxime was 99.2%. Met. The reaction was terminated because the oxygen concentration in the autoclave rapidly increased 106 hours after the start of the reaction.

Comparative Example 1
An ammoximation reaction was carried out in the same manner as in Example 1 using TS-1 (commercially available product), which is a titanosilicate having an MFI structure, as a catalyst. Note that the X-ray diffraction pattern of TS-1 used here is as shown in FIG. 3, and d = 13.2 ± 0.6 mm (around 2θ = 6.7 °) or d = Peaks such as 12.3 ± 0.3Å (around 2θ = 7.2 °) are not observed.

  As a result of analyzing the liquid phase extracted 1.5 hours after the start of the reaction, the conversion of cyclohexanone was 70.9%, the selectivity of cyclohexanone oxime was 98.7%, and the yield of cyclohexanone oxime was 70.0%. Met. Three hours after the start of the reaction, the oxygen concentration in the autoclave rapidly increased, so the reaction was terminated.

2 is a chart showing an X-ray diffraction pattern of titanosilicate (Ti-MWW precursor) prepared and used in Example 1. FIG. 2 is a chart showing an X-ray diffraction pattern of titanosilicate (Ti-MWW) obtained by firing the titanosilicate prepared in Example 1. FIG. 6 is a chart showing an X-ray diffraction pattern of titanosilicate (TS-1) used in Comparative Example 1.

Claims (5)

The X-ray diffraction pattern with peaks at the following positions in the lattice spacing display shows, and in the presence of a titanosilicate before structural conversion to MWW structure by dehydration condensation between the layers occurs, ketone peroxides And an ammoximation reaction with ammonia.
Lattice spacing d (Å):
13.2 ± 0.6,
12.3 ± 0.3,
11.0 ± 0.3,
9.0 ± 0.3,
6.8 ± 0.3,
3.9 ± 0.2,
3.5 ± 0.1,
3.4 ± 0.1.   The production method according to claim 1, wherein the atomic ratio of titanium to silicon in the titanosilicate is 0.0001 to 0.1.   The production method according to claim 1, wherein the peroxide is hydrogen peroxide.   The manufacturing method in any one of Claims 1-3 which perform an ammoximation reaction in the mixed solvent of alcohol and water.   The production method according to any one of claims 1 to 4, wherein the ketone is a cycloalkane.

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