Solid catalyst and method for preparing phosphite ester compound

Abstract

The invention discloses a solid catalyst. The solid catalyst comprises a ZSM-5 molecular sieve and potassium hydroxide loaded in the ZSM-5 molecular sieve. The invention also discloses a method for preparing a phosphite ester compound by using the solid catalyst, and the solid catalyst not only shows excellent catalytic activity, but also is simple in catalyst recovery process and can be repeatedly utilized for multiple times.

Description

Technical Field

[0001] The invention belongs to the technical field of organic synthesis, and in particular relates to a solid catalyst and a preparation method of a phosphite compound. Background Art

[0002] Phosphite antioxidants are mainly used in the synthetic rubber industry, polyether and polyurethane industry, and PVC stabilizer industry. As downstream industries have higher and higher requirements for environmental protection and phenol-free, traditional phenol-containing liquid phosphite antioxidants such as trinonylphenyl phosphite, triphenyl phosphite, and diphenyl isooctyl phosphite can no longer adapt to the development of the industry, and the demand for alkyl phosphite antioxidants represented by trioctyl phosphite, tridecyl phosphite, dodecyl phosphite, and tridecyl phosphite is gradually increasing.

[0003] Triisodecyl phosphite (CAS No. 25448-25-3), molecular formula (C 10 H 21 O)3P. The traditional synthesis method of the antioxidant triisodecyl phosphite is to use long-chain alcohol and phosphorus trichloride as raw materials, and triethylamine, pyridine or ammonia as acid binding agents to carry out esterification reaction to generate the target product. The process flow of the method for preparing triisodecyl phosphite by esterification reaction using long-chain alcohol and phosphorus trichloride as raw materials is relatively simple, but a large amount of hydrogen chloride gas by-product will be generated during the reaction. The conventional treatment method is to absorb it with water, which will produce a large amount of acidic wastewater, increasing the cost of post-treatment. In addition, hydrogen chloride will cause greater corrosion to the production equipment of metal materials, thereby increasing the cost of the equipment.

[0004] In order to avoid using phosphorus trichloride as a raw material to generate hydrogen chloride gas, an ester exchange reaction can be used instead of an esterification reaction. One method is to use phenyl phosphite and a long-chain alcohol as raw materials to carry out an ester exchange reaction to prepare trialkyl phosphite. For example, patent application CN1123284A discloses a method for preparing octadecyl phosphite, wherein triphenyl phosphite and octadecyl alcohol are used as raw materials and potassium carbonate is used as a catalyst to carry out an ester exchange reaction to prepare the target product. This method uses phenyl phosphite as a raw material, and phenol as a byproduct is produced during the reaction. The residual phenol will cause the product to face restrictions such as environmental regulations.

[0005] Another method for preparing triisodecyl phosphite, an antioxidant, is to use short-chain alkyl phosphites such as trimethyl phosphite or triethyl phosphite and long-chain alcohols as raw materials, and use organic or inorganic bases as catalysts to carry out ester exchange reactions to generate target products. For example, patent GB2489896B discloses a method for preparing trialkyl phosphites, which uses trimethyl phosphite and isodecyl alcohol as raw materials and uses sodium methoxide as a catalyst to carry out ester exchange reactions. However, this process has the following two major problems: (1) the byproduct methanol and the excess isodecyl alcohol cannot be separated well, resulting in the presence of part of isodecyl alcohol in the evaporated methanol, which causes trouble for the recovery and reuse of methanol; (2) the catalyst sodium methoxide is waxy after the reaction is completed, which will block the pores of the filter paper when filtering and removing, resulting in a very slow filtration speed. At the same time, the catalyst sodium methoxide cannot be reused, and post-treatment of it will also produce alkaline wastewater.

[0006] Therefore, it is urgent to develop a new method for producing triisodecyl phosphite. Summary of the invention

[0007] In view of the deficiencies in the prior art, the present invention provides a solid catalyst and a method for synthesizing a liquid phosphite compound using the catalyst. The solid catalyst of the present invention is a KOH-impregnated ZSM-5 molecular sieve catalyst, which not only exhibits excellent catalytic activity in the synthesis of phosphite compounds, especially the synthesis of triisodecyl phosphite, but also has a simple catalyst recovery process and can be reused many times. In the synthesis method, a packed column and a vacuum distillation method are used to timely discharge the by-products of the reaction from the reaction system, which promotes the forward progress of the reaction while improving the separation between the by-product methanol and the excess isodecyl alcohol.

[0008] According to a first aspect of the present invention, a solid catalyst is provided. The solid catalyst comprises a ZSM-5 molecular sieve and potassium hydroxide supported in the ZSM-5 molecular sieve.

[0009] In some embodiments, the loading amount of potassium hydroxide in the solid catalyst is 0.1-15%, preferably 5-15%. In some specific embodiments, the loading amount of potassium hydroxide in the solid catalyst is 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12.5%, 15% or any value therebetween.

[0010] In some embodiments, the solid catalyst is prepared by an isovolumetric impregnation method.

[0011] In some embodiments, the solid catalyst is prepared by a method comprising the following steps: impregnating an equal volume of the calcined ZSM-5 molecular sieve in a KOH solution; and then drying and calcining the impregnated ZSM-5 molecular sieve.

[0012] In some embodiments, the calcination temperature is 100-300°C, and the time is 1-3h. In some specific embodiments, the calcination temperature is 100°C, 150°C, 170°C, 180°C, 200°C, 220°C, 240°C, 250°C, 300°C or any value therebetween, and in some specific embodiments, the calcination time is 1h, 1.5h, 1.8h, 2h, 2.2h, 2.5h, 3h or any value therebetween.

[0013] In some embodiments, the immersion time is 20-60 min. In some specific embodiments, the immersion time is 20 min, 30 min, 40 min, 50 min, 60 min or any value therebetween.

[0014] In some embodiments, the drying temperature is 110-160°C, and the drying time is 2-10h. In some specific embodiments, the drying temperature is 110°C, 120°C, 130°C, 140°C, 150°C, 160°C or any value therebetween, and in some specific embodiments, the calcination time is 2h, 4h, 6h, 8h, 10h or any value therebetween.

[0015] In some embodiments, the calcination temperature is 100-500°C and the time is 5-10h. In some specific embodiments, the calcination temperature is 100°C, 200°C, 250°C, 300°C, 350°C, 400°C, 500°C or any value therebetween, and in some specific embodiments, the calcination time is 5h, 6h, 7h, 8h, 9h, 10h or any value therebetween.

[0016] According to a second aspect of the present invention, there is provided use of the solid catalyst described in the first aspect in an ester exchange reaction.

[0017] In some embodiments, the transesterification reaction is a transesterification reaction in the preparation of phosphite compounds.

[0018] According to a third aspect of the present invention, there is provided a method for preparing phosphite compounds, comprising subjecting a C5-C20 alkyl alcohol and a C1-C3 alkyl phosphite to an ester exchange reaction in the presence of the solid catalyst described in the first aspect.

[0019] In some embodiments, the mass ratio of the C5-C20 alkyl alcohol to the solid catalyst is 1.0:(0.1-1.0), preferably 1.0:(0.2-0.6). In some specific embodiments, the mass ratio of the C5-C20 alkyl alcohol to the solid catalyst is 1.0:0.1, 1.0:0.2, 1.0:0.4, 1.0:0.6, 1.0:0.8, 1.0:1.0 or any value therebetween.

[0020] In some embodiments, the mass ratio of the C5-C20 alkyl alcohol to the potassium hydroxide in the solid catalyst is 1.0:(0.01-0.1), preferably 1.0:(0.01-0.05). In some embodiments, the mass ratio of the C5-C20 alkyl alcohol to the potassium hydroxide in the solid catalyst is 1.0:0.01, 1.0:0.02, 1.0:0.04, 1.0:0.06, 1.0:0.08, 1.0:0.1 or any value therebetween.

[0021] In some embodiments, the molar ratio of the C5-C20 alkyl alcohol to tri-C1-C3 alkyl phosphite is (1.0-10.0): 1, preferably (3.0-5.0): 1. In some specific embodiments, the molar ratio of the C5-C20 alkyl alcohol to tri-C1-C3 alkyl phosphite is 1.0: 1, 2.0: 1, 3.0: 1, 4.0: 1, 5.0: 1, 6.0: 1, 8.0: 1, 10.0: 1 or any value therebetween.

[0022] In some embodiments, the tri-C1-C3 alkyl phosphite is selected from trimethyl phosphite and / or triethyl phosphite.

[0023] In some embodiments, the temperature of the transesterification reaction is 100-200° C., preferably 120-180° C. In some specific embodiments, the temperature of the transesterification reaction is 100° C., 120° C., 140° C., 150° C., 160° C., 180° C., 200° C. or any value therebetween.

[0024] In some embodiments, the transesterification reaction time is 0.5-15 h, preferably 2-10 h. In some specific embodiments, the transesterification reaction time is 0.5 h, 1 h, 2 h, 4 h, 6 h, 8 h, 10 h, 12 h, 15 h or any value therebetween.

[0025] In some embodiments, the method comprises the steps of:

[0026] (1) adding tri-C1-C3 alkyl phosphite dropwise into a reaction mass containing the C5-C20 alkyl alcohol and the solid catalyst;

[0027] (2) After the addition of tri-C1-C3 alkyl phosphite is completed, the by-product ethanol and the excess C5-C20 alkyl alcohol generated in the reaction system are removed by vacuum distillation;

[0028] (3) Separating the solid catalyst from the reaction system to obtain the phosphite compound.

[0029] In some embodiments, in step (1), the temperature for starting to add tri-C1-C3 alkyl phosphite is 80-110°C, for example, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C or any value therebetween.

[0030] In some embodiments, in step (1), the time for adding tri-C1-C3 alkyl phosphite dropwise is 2-10 h, for example, 2 h, 4 h, 6 h, 8 h, 10 h or any value therebetween.

[0031] In some embodiments, in step (1), during the dropwise addition of tri-C1-C3 alkyl phosphite, the temperature is raised to 120-180°C (for example, 120°C, 140°C, 150°C, 160°C, 180°C or any value therebetween) within 1.5-2.5h (for example, 1.5h, 1.8h, 2.0h, 2.2h, 2.5h or any value therebetween) and then kept warm.

[0032] In some embodiments, the vacuum distillation includes performing a vacuum reaction after the addition of tri-C1-C3 alkyl phosphite is completed, then cooling and depressurizing the reaction system to extract ethanol; then heating and depressurizing the reaction system to extract excess C5-C20 alkyl alcohol.

[0033] In some embodiments, the vacuum degree of the reduced pressure reaction is 0.01-0.05 MPa, for example, 0.01 MPa, 0.02 MPa, 0.03 MPa, 0.04 MPa, 0.05 MPa or any value therebetween.

[0034] In some embodiments, the temperature of the reduced pressure reaction is 120-180°C, for example, 120°C, 140°C, 150°C, 160°C, 180°C or any value therebetween.

[0035] In some embodiments, the time of the reduced pressure reaction is 1-3 h, for example, 1 h, 1.5 h, 2 h, 2.5 h, 3 h or any value therebetween.

[0036] In some embodiments, the temperature of the reaction system is lowered to below 60° C., and the ethanol is extracted after the pressure is released.

[0037] In some embodiments, the temperature of the reaction system is raised to 180-200°C (for example, 180°C, 185°C, 190°C, 195°C, 200°C or any value therebetween) and the absolute pressure is 0.1-1.0 kPa (for example, 0.1 kPa, 0.2 kPa, 0.4 kPa, 0.6 kPa, 0.8 kPa, 1.0 kPa or any value therebetween), and the excess C5-C20 alkyl alcohol is produced.

[0038] In some embodiments, in step (3), the temperature of the reaction system is lowered to below 60° C., and the solid catalyst is filtered out of the reaction system after the pressure is released.

[0039] In some embodiments, the phosphite compound has a structure shown in Formula I,

[0040]

[0041] In Formula I, R1 to R3 are each independently selected from a C5-C20 straight or branched chain alkyl group.

[0042] In some embodiments, in Formula I, R1 to R3 are each independently selected from C6-C14 linear or branched alkyl groups.

[0043] In some embodiments, the phosphite compound includes triisodecyl phosphite, triisooctyl phosphite, tridodecyl phosphite or tritridecyl phosphite.

[0044] According to a fourth aspect of the present invention, there is provided a device for use in the method described in the third aspect, the device comprising a reaction kettle and a sample injector connected to the reaction kettle.

[0045] In some embodiments, the device further comprises a packed tower, and the upper end of the column of the packed tower is sequentially connected to a distillation head, a condenser, a tail pipe and a extraction kettle.

[0046] In some embodiments, the column of the packed tower is a glass column, and the filler is a stainless steel theta ring filler.

[0047] In some embodiments, the condenser is a straight condenser.

[0048] In some embodiments, the sample injector is a dropping funnel, preferably a constant pressure dropping funnel.

[0049] In some embodiments, the device further comprises a heater.

[0050] The device of the present invention adopts a packed tower column filled with fillers to connect the reaction kettle and the distillation device. During the dripping and decompression reaction of tri-C1-C3 alkyl phosphite, this section of the packed tower can better separate the by-product ethanol and the excess isodecyl alcohol, which not only promotes the forward progress of the reaction, but also improves the purity of the ethanol and isodecyl alcohol collected during the reaction, and simplifies the process flow; the purity of the recovered ethanol is above 99%, and can be directly used in the chemical field.

[0051] The catalyst used in the method for preparing phosphite compounds of the present invention is a solid base catalyst, and the ZSM-5 molecular sieve used as a carrier has a large specific surface area, which improves the catalytic efficiency of the solid base catalyst. On the other hand, due to its large particles, the filtration speed after the reaction is completed is faster than that of traditional organic or inorganic bases and can be reused. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 A schematic diagram of a reaction device used according to some embodiments of the present invention is shown, wherein 1 is a heating jacket, 2 is a straight four-necked flask, 3 is a packed tower, the packing in the tower is a stainless steel theta ring packing, 4 is a distillation head, 5 is a straight condenser, 6 is a tail pipe, 7 is a constant pressure dropping funnel, and 8 is a single-necked flask. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. The specific embodiments described herein are only used to explain the present invention and are not intended to constitute any limitation to the present invention. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concepts of the present disclosure. Such structures and technologies are also described in many publications.

[0054] The present invention relates to a solid catalyst, which is obtained by the following method:

[0055] (1) Test of carrier water absorption rate: a certain mass of carrier ZSM-5 molecular sieve is placed in a muffle furnace and calcined at 200°C for 1 hour to fully dry the residual water on the surface of the molecular sieve, and then the mass of the dried molecular sieve is weighed and recorded as m1. The dried molecular sieve is placed in a beaker filled with pure water and soaked for 1 hour. After the molecular sieve is fully absorbed by water, the molecular sieve is taken out, and the molecular sieve is wiped dry with absorbent paper and weighed, recorded as m2. The water absorption rate of the molecular sieve = (m2-m1) / m1*100%;

[0056] (2) Equal volume impregnation method: Weigh a certain mass of molecular sieve, whose mass is recorded as m3, and dissolve KOH with a mass of m3*x in pure water according to the loading rate x%, where the mass of pure water is the water absorption rate of the molecular sieve*m3. Then, immerse the molecular sieve with a mass of m3 in the above KOH solution and stir evenly. After ultrasonic vibration at room temperature for 30 minutes, take out and put it into an oven at 110-160°C for drying, and then put it into a muffle furnace at 100-500°C for calcination for 5-10 hours to obtain a solid catalyst.

[0057] The present invention also relates to a preparation method of a liquid phosphite compound. Taking triisodecyl phosphite as an example, the preparation method comprises: adding isodecyl alcohol and a self-made solid alkaline catalyst into a straight four-necked flask, starting to heat up, and when the temperature reaches the dropping temperature, starting to drop triethyl phosphite, heating up to the reaction temperature within a certain period of time during the dropping process, and then keeping the temperature at this temperature, connecting the reaction device to a vacuum pump after the dropping of triethyl phosphite is completed, performing a reduced pressure reaction at the reaction temperature, cooling the temperature to below 60°C after the reduced pressure reaction is completed, pouring out the collected ethanol after nitrogen pressure relief, rebuilding the device and connecting the oil pump to extract excess isodecyl alcohol, first cooling the temperature to below 60°C after the isodecyl alcohol is distilled and extracted, and then releasing the pressure with nitrogen, and then filtering the reaction liquid to filter out the catalyst to obtain a final product.

[0058] The present invention also relates to a device for the above-mentioned preparation method, such as Figure 1 As shown, the device comprises: a constant pressure dropping funnel (7) of a sampler connected to a straight four-necked flask (2) of a reaction kettle and a section of a glass filling column (3), a distillation head (4), a straight condenser (5), a tail pipe (6) and a single-necked flask (7) of a sampling kettle connected to the upper end of the column, and a heating jacket (1).

[0059] In some embodiments, taking the preparation of triisodecyl phosphite as an example, the preparation method comprises the following steps:

[0060] a. Add isodecyl alcohol and solid catalyst in a mass ratio of 1:0.01-0.05 into a straight four-necked flask, connect a constant pressure dropping funnel and a glass packing column, connect a distillation head, a condenser and a tail pipe to the upper end of the column, and start heating; the solid catalyst used is a KOH / ZSM-5 synthetic molecular sieve catalyst, which uses a ZSM-5 molecular sieve as a carrier and KOH as a catalytically active substance, and is prepared by an equal volume impregnation method;

[0061] b. When the temperature reaches 80-110°C, start to drop triethyl phosphite. During the dropping process, the temperature is raised to 120-180°C in 1.5-2.5 hours by a staged heating method, and then kept at this temperature. The dropping time of triethyl phosphite is 2-10 hours, and the molar ratio of isodecyl alcohol to triethyl phosphite is (3.0-5.0):1;

[0062] c. After the addition of triethyl phosphite is completed, the reaction device is connected to a vacuum pump, the vacuum degree is adjusted to 0.01-0.05 MPa, and the reaction is kept at 120-180°C for 1-3 hours to separate the light components in the system in the column, the isodecyl alcohol with a higher boiling point is condensed back into the reactor, and the ethanol with a lower boiling point is extracted from the system through the condenser;

[0063] d. After the reaction is completed, the temperature is lowered to below 60°C, the collected ethanol is poured out after the nitrogen pressure is released, the device is rebuilt and connected to the oil pump, and the temperature is raised to 180-200°C. The absolute pressure in the kettle is 0.1-1.0 kPa, and the excess isodecyl alcohol is extracted;

[0064] e. After the distillation of isodecyl alcohol is completed, the temperature is first lowered to below 60°C and then the pressure is released by nitrogen. The reaction liquid is then filtered to filter out the catalyst to obtain the final product.

[0065] The reagents and / or materials used in the following examples are commercially available or can be synthesized by known methods.

[0066] Example 1

[0067] A method for preparing a solid base catalyst is achieved by the following steps:

[0068] a. Weigh 100 g of molecular sieve ZSM-5 calcined in a muffle furnace at 200°C for 1 hour, and soak it in pure water enough to cover the molecular sieve for 1 hour;

[0069] b. After fully absorbing water, take out the molecular sieve and wipe off the free water on its surface with absorbent paper. Then weigh its mass to be 125.48g. The water absorption rate of the molecular sieve is 25.48%;

[0070] c. Take another 100g of molecular sieve ZSM-5 calcined in a muffle furnace at 200°C for 2h and put it into a ziplock bag. According to the loading amount of 5%, weigh 5g of KOH and dissolve it in 25.48g of pure water. Pour the KOH solution into the ziplock bag containing the molecular sieve and seal the bag. Put the ziplock bag into an ultrasonicator for shaking and mixing for 30min and then let it stand for 2h to prepare a catalyst precursor.

[0071] d. The precursor after standing was placed in an oven at 150°C and dried for 4-5 hours to constant weight, and then placed in a muffle furnace and calcined at 300°C for 10 hours. After cooling, the solid base catalyst A was obtained.

[0072] Example 2

[0073] A method for preparing a solid base catalyst is achieved by the following steps:

[0074] The operations of step a and step b are the same as those of Example 1.

[0075] c. Weigh 100 g of molecular sieve ZSM-5 calcined in a muffle furnace at 200° C. for 2 h and put it into a ziplock bag. Weigh 10 g of KOH according to a loading amount of 10% and dissolve it in 25.48 g of pure water. Pour the KOH solution into the ziplock bag containing the molecular sieve and seal the bag. Put the ziplock bag into an ultrasonicator for shaking and mixing for 30 min and then let it stand for 2 h to prepare a catalyst precursor.

[0076] b. The precursor after standing was placed in an oven at 150°C for drying for 4-5 hours to constant weight, and then placed in a muffle furnace for calcination at 300°C for 10 hours. After cooling, the solid base catalyst B was obtained.

[0077] Example 3

[0078] A method for preparing a solid base catalyst is achieved by the following steps:

[0079] The operations of step a and step b are the same as those of Example 1.

[0080] c. Weigh 100 g of molecular sieve ZSM-5 calcined in a muffle furnace at 200° C. for 2 h and put it into a ziplock bag. Weigh 15 g of KOH according to a loading of 15% and dissolve it in 25.48 g of pure water. Pour the KOH solution into the ziplock bag containing the molecular sieve and seal the bag. Put the ziplock bag into an ultrasonicator for oscillation and mixing for 30 min and then let it stand for 2 h to prepare a catalyst precursor.

[0081] b. The precursor after standing was placed in an oven at 150°C for 4-5 hours to dry to constant weight, and then placed in a muffle furnace for calcination at 300°C for 10 hours. After cooling, the solid base catalyst C was obtained.

[0082] Example 4

[0083] A method for preparing a liquid phosphite antioxidant triisodecyl phosphite, using Figure 1 The device shown is implemented according to the following steps:

[0084] a. Add isodecyl alcohol and homemade solid alkaline catalyst A in a mass ratio of 1:0.6 into a straight four-necked flask, connect a constant pressure dropping funnel and a glass packing column, connect a distillation head, a condenser and a tail pipe to the upper end of the column, and start heating.

[0085] b. When the temperature reaches 95°C, start to drop triethyl phosphite. During the dropping process, the temperature is raised to 140°C in 2 hours by a step-by-step heating method, and then kept at this temperature. The dropping time of triethyl phosphite is 4 hours, wherein the molar ratio of isodecyl alcohol to triethyl phosphite is 4:1;

[0086] c. After the addition of triethyl phosphite was completed, the reaction apparatus was connected to a vacuum pump, the vacuum degree was adjusted to 0.03 MPa, and the reaction was kept at 140°C for 2 hours, and the ethanol generated by the reaction was evaporated;

[0087] d. After the reaction is completed, the temperature is lowered to below 60°C, and the collected ethanol is poured out after the nitrogen pressure is released (after testing, the purity of the recovered ethanol is above 99%). The device is rebuilt and connected to the oil pump, and the temperature is raised to 190-195°C, and the vacuum degree is gradually increased to an absolute pressure of 600Pa to extract the excess isodecyl alcohol;

[0088] e. After the distillation of isodecyl alcohol is completed, the temperature is first lowered to below 60°C and then the pressure is released by nitrogen. The reaction liquid is then filtered to filter out the catalyst to obtain the final product. The catalyst filtration time is 10-15s. The content of the finished product is 90.32% as detected by gas chromatography, and the reaction yield is 78.33%.

[0089] Example 5

[0090] A method for preparing triisodecyl phosphite, a liquid phosphite antioxidant. The catalyst used in this embodiment is a solid base catalyst B, which is added according to a mass ratio of isodecyl alcohol to the solid base catalyst of 1:0.3. The remaining steps are the same as those in Example 4, the catalyst filtering time is also 10-15s, the finished product content is 93.18%, and the reaction yield is 82.48%.

[0091] Example 6

[0092] A method for preparing triisodecyl phosphite, a liquid phosphite antioxidant. The catalyst used in this embodiment is a solid base catalyst C, which is added according to a mass ratio of isodecyl alcohol to the solid base catalyst of 1:0.2. The remaining steps are the same as those in Example 4, the catalyst filtering time is also 10-15s, the finished product content is 94.33%, and the reaction yield is 83.41%.

[0093] Example 7

[0094] This embodiment is an application experiment of solid base catalyst A, and the specific implementation method is:

[0095] The solid base catalyst recovered in Example 6 was soaked in methanol and cleaned with an ultrasonic cleaner. After cleaning for 30 minutes, it was dried in an oven at 100°C for 2 hours to dry the methanol remaining on the surface and inside of the catalyst for later use. Isodecyl alcohol and the cleaned and dried catalyst were added to a straight four-necked flask at a mass ratio of 1:0.2 to start the reaction, and the subsequent reaction steps were the same as in Example 6. Five catalyst application experiments were carried out according to the above method, and the reaction results are shown in Table 1 below.

[0096] Table 1 Solid base catalyst application experimental results

[0097] Number of applications Finished product content (%) Reaction yield (%) Catalyst filtration time (s) first 94.01 83.13 10-15 Second time 93.85 83.24 10-15 The third time 93.43 82.78 10-15 Fourth 92.87 82.32 10-15 Fifth 92.55 82.05 10-15

[0098] It can be seen from the above table that with the increase in the number of applications, the content of the finished product and the reaction yield decreased slightly, but after five application experiments, the decrease in content and yield was within 2%, indicating that the catalyst has a good reuse effect.

[0099] Comparative Example 1

[0100] A method for preparing triisodecyl phosphite, a liquid phosphite antioxidant, wherein the catalyst used in the comparative example is KOH particles, which are added according to a mass ratio of isodecyl alcohol to KOH of 1:0.03, and the remaining steps are the same as those in Example 4, the catalyst filtration time is about 5-6 minutes, the filter cake is waxy, and the catalyst KOH cannot be recovered. The content of the triisodecyl phosphite product obtained by the reaction is 85.91%, and the yield of the reaction is 72.24%.

[0101] Comparative Example 2

[0102] A method for preparing triisodecyl phosphite, a liquid phosphite antioxidant, wherein the catalyst used in the comparative example is sodium methoxide / methanol solution, which is added according to a mass ratio of isodecyl alcohol to sodium methoxide / methanol solution of 1:0.03, and the remaining steps are the same as those in Example 4, the catalyst filtration time is about 7-8 minutes, the filter cake is waxy, and the catalyst sodium methoxide / methanol solution cannot be recovered. The content of the triisodecyl phosphite product obtained by the reaction is 90.91%, and the yield of the reaction is 80.36%.

[0103] Comparative Example 3

[0104] A method for preparing triisodecyl phosphite, a liquid phosphite antioxidant. The difference between this comparative example and Example 4 is that in step a, no column with filler is used, the straight four-necked flask is directly connected to the distillation head, and the remaining steps are exactly the same as those in Example 4. The catalyst filtering time is 10-15s, the finished product content is 90.18%, and the reaction yield is 75.24%.

[0105] The contents of ethanol and isodecyl alcohol recovered in Examples 4-6 and Comparative Example 3 are shown in Table 2 below.

[0106] Table 2 Content of ethanol and isodecyl alcohol in ethanol recovered from Examples 4-6 and Comparative Example 3

[0107]

[0108] As can be seen from the above table, after using a column equipped with fillers to connect the four-necked flask and the distillation head in Examples 4-6, the separation effect of ethanol and isodecyl alcohol is better, and the extracted ethanol does not contain isodecyl alcohol, while the ethanol extracted in Comparative Example 3 without using a column contains 2.39% isodecyl alcohol, indicating that ethanol and isodecyl alcohol are separated in the column during the reduced pressure reflux reaction, and isodecyl alcohol with a higher boiling point refluxes back into the system.

[0109] Comparative Example 4

[0110] In this comparative example, NaOH is used as the catalytic active substance and ZSM-5 molecular sieve is used as the carrier. The catalyst preparation method is the same as that in Example 1, and the loading amount of NaOH is set to 5%.

[0111] The solid base catalyst was used to synthesize triisodecyl phosphite, the mass ratio of isodecyl alcohol to the catalyst was 1:0.6, the synthesis method was the same as that in Example 4, the content of the finished product was 88.33%, and the reaction yield was 75.68%.

[0112] It can be seen from the experimental results of Comparative Example 4 that the catalytic efficiency of the solid base catalyst using NaOH as the active substance is significantly lower than that using KOH as the catalytic active substance.

[0113] Comparative Example 5

[0114] This comparative example uses 4A molecular sieve as a carrier and KOH as a catalytically active substance. The catalyst preparation method is the same as that of Example 1. The water absorption rate of the 4A molecular sieve is 21.5% through experimental detection, and the KOH loading amount is set to 10%.

[0115] The above solid base was used as a catalyst to synthesize triisodecyl phosphite, the mass ratio of isodecyl alcohol to the catalyst was 1:0.3, the synthesis method was the same as that in Example 4, the catalyst was filtered for 10-15s after the reaction, the finished product content was 90.12%, and the reaction yield was 70.33%.

[0116] It can be seen from Comparative Example 5 that although the content of triisodecyl phosphite prepared by catalytically preparing the solid base catalyst using 4A molecular sieve as a carrier is not much different from that in Example 4, the reaction yield is significantly lower than that in Example 4, which results in the catalytic efficiency of the solid base catalyst prepared by 4A molecular sieve being lower than that of ZSM-5.

[0117] Comparative Example 6

[0118] This comparative example uses Y-type molecular sieve as a carrier and KOH as a catalytically active substance. The catalyst preparation method is the same as that of Example 1. The water absorption rate of the Y-type molecular sieve is 33.5% through experimental detection, and the KOH loading amount is set to 15%.

[0119] The solid base catalyst was used to synthesize triisodecyl phosphite, the mass ratio of isodecyl phosphite to catalyst was 1:0.2, the synthesis method was the same as that in Example 4, the catalyst was filtered for 10-15s after the reaction, the finished product content reached 93.55% after the first reaction, and the reaction yield was 84.12%, but the catalytic activity of the catalyst used in this comparative example decreased significantly during repeated experiments.

[0120] The solid base catalyst recovered after the first reaction was further immersed in methanol and cleaned with an ultrasonic cleaner. After cleaning for 30 minutes, the catalyst was dried in an oven at 100°C for 2 hours to dry the methanol remaining on the surface and inside of the catalyst for later use. Isodecyl alcohol and the cleaned and dried catalyst were added to a straight four-necked flask at a mass ratio of 1:0.2 to start the reaction, and the subsequent reaction steps were the same as those in Comparative Example 5. Five catalyst application experiments were carried out in the same manner as in Example 7, and the reaction results are shown in Table 3 below.

[0121] Table 3 Comparative Example 6 Solid Base Catalyst Application Experimental Results

[0122] Number of applications Finished product content (%) Reaction yield (%) Catalyst filtration time (s) first 93.55 84.12 10-15 Second time 92.17 81.19 10-15 The third time 89.43 78.33 30-40 Fourth 88.21 77.58 40-50 Fifth 87.24 73.48 ＞60

[0123] It can be seen from Comparative Example 6 that although the catalytic effect of the solid base catalyst prepared with Y-type molecular sieve as the carrier is equivalent to that of Example 6 in the first reaction, the catalytic effect of the catalyst is significantly reduced after repeated use, and the catalyst filtration time will also be prolonged.

[0124] The technical solution of the present invention is not limited to the above-mentioned specific embodiments. All technical variations made according to the technical solution of the present invention fall within the protection scope of the present invention.

Claims

1. A solid catalyst comprising a ZSM-5 molecular sieve and potassium hydroxide supported in the ZSM-5 molecular sieve.

2. The solid catalyst according to claim 1, characterized in that In the solid catalyst, the loading amount of potassium hydroxide is 0.1-15%, preferably 5-15%.

3. Use of the solid catalyst according to claim 1 or 2 in transesterification reaction.

4. A method for preparing phosphite compounds, comprising subjecting a C5-C20 alkyl alcohol and a C1-C3 alkyl phosphite to an ester exchange reaction in the presence of the solid catalyst according to claim 1 or 2.

5. The method according to claim 4, characterized in that The mass ratio of the C5-C20 alkyl alcohol to the solid catalyst is 1.0:(0.1-1.0), preferably 1.0:(0.2-0.6); and / or The mass ratio of the C5-C20 alkyl alcohol to the potassium hydroxide in the solid catalyst is 1.0:(0.01-0.1), preferably 1.0:(0.01-0.05); and / or The molar ratio of the C5-C20 alkyl alcohol to the tri-C1-C3 alkyl phosphite is (1.0-10.0):1, preferably (3.0-5.0):1; Preferably, the tri-C1-C3 alkyl phosphite is selected from trimethyl phosphite and / or triethyl phosphite.

6. The method according to claim 4 or 5, characterized in that: The temperature of the transesterification reaction is 100-200°C, preferably 120-180°C; and / or The transesterification reaction time is 0.5-15h, preferably 2-10h.

7. The method according to any one of claims 4 to 6, characterized in that: The method comprises the following steps: (1) adding tri-C1-C3 alkyl phosphite dropwise to a reaction mass containing the C5-C20 alkyl alcohol and the solid catalyst, (2) After the addition of tri-C1-C3 alkyl phosphite is completed, the by-product ethanol and the excess C5-C20 alkyl alcohol generated in the reaction system are removed by vacuum distillation; (3) Separating the solid catalyst from the reaction system to obtain the phosphite compound.

8. The method according to claim 7, characterized in that In step (1), the temperature for starting to dropwise add the tri-C1-C3 alkyl phosphite is 80-110° C., and / or the time for dropping the tri-C1-C3 alkyl phosphite is 2-10 h; preferably, during the dropping process, the temperature is raised to 120-180° C. within 1.5-2.5 h and then kept warm; and / or In step (2), the reduced pressure distillation includes performing a reduced pressure reaction after the dropwise addition of tri-C1-C3 alkyl phosphite is completed, then cooling and depressurizing the reaction system to extract the ethanol; then heating and depressurizing the reaction system to extract the excess C5-C20 alkyl alcohol; Preferably, the vacuum degree of the reduced pressure reaction is 0.01-0.05 MPa, and / or the temperature of the reduced pressure reaction is 120-180° C., and / or the time of the reduced pressure reaction is 1-3 h; preferably, the temperature of the reaction system is reduced to below 60° C., and the ethanol is extracted after the pressure is released; Preferably, the temperature of the reaction system is raised to 180-200°C and the absolute pressure is 0.1-1.0 kPa, and the excess C5-C20 alkyl alcohol is removed; and / or In step (3), the temperature of the reaction system is lowered to below 60° C., and the solid catalyst is filtered out from the reaction system after the pressure is released.

9. The method according to any one of claims 4 to 8, characterized in that: The phosphite compound has a structure shown in Formula I, In formula I, R1 to R3 are each independently selected from C5-C20 straight chain or branched chain alkyl, preferably selected from C6-C14 straight chain or branched chain alkyl; Preferably, the phosphite compound includes triisodecyl phosphite, triisooctyl phosphite, tridodecyl phosphite or tritridecyl phosphite.

10. An apparatus for the method according to any one of claims 4 to 9, characterized in that: The device comprises a reaction kettle and a sample injector connected to the reaction kettle; Preferably, the device further comprises a packing tower connected to the reactor, and the upper end of the column of the packing tower is sequentially connected to a distillation head, a condenser, a tail pipe and a production kettle; More preferably, the column of the packed tower is a glass column, and the filler is a stainless steel theta ring filler; More preferably, the condenser is a straight condenser; Preferably, the sample adder is a dropping funnel; Preferably, the device further comprises a heater.

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