Method for co-production of methacrylate and methallyl alcohol

Abstract

The invention relates to a method for co-producing methacrylate and methylallyl alcohol, which comprises the following steps: mixing methylacrolein, a first catalyst and an aprotic non-polar solvent, and carrying out a Songcheng reaction to obtain a first reaction solution; the first catalyst comprises an aluminum alkoxide catalyst; fatty alcohol, a second catalyst and the first reaction liquid are mixed for transesterification, and methacrylate and methylallyl alcohol are prepared; the second catalyst comprises at least one of titanate and organic tin. According to the method, the methacrylate and the methylallyl alcohol can be co-produced through a one-pot method, the yield is high, byproducts are few, and the purity of the methacrylate and the purity of the methylallyl alcohol are high.

Description

Technical Field

[0001] The present application relates to the field of synthesis technology, and in particular to a method for co-producing methacrylate and methallyl alcohol. Background Art

[0002] Methyl methacrylate (MMA) is an important chemical raw material and a monomer of polymethyl methacrylate. It is mainly used in the production of organic glass (PMMA) and can also be copolymerized with other vinyl monomers to obtain products with different properties. It is widely used in organic glass, coatings, lubricant additives, plastics, adhesives, resins, wood impregnation agents, motor coil impregnation agents, ion exchange resins, paper polishes, textile printing and dyeing auxiliaries, leather treatment agents, printing and dyeing auxiliaries, and insulating potting materials.

[0003] The traditional process routes for preparing MMA are: the propionaldehyde route (BASF process) has obvious raw material advantages, high utilization rate, no wastewater discharge in the production process, and is green and environmentally friendly; the isobutylene or tert-butyl alcohol route, also collectively referred to as the "isobutylene method", has obvious raw material advantages, high utilization rate, no wastewater discharge in the production process, and is green and environmentally friendly; but the BASF method and the "isobutylene method" both involve the use of precious metal palladium or gold catalysts, the catalyst preparation process is relatively complicated, and the precious metals are expensive and the cost is high; the methyl propionate route (Alpha process) has mild process operating conditions, high product yield, low equipment investment and raw material costs, and easy to expand the scale of a single set of equipment, but the methyl propionate conversion rate is low; the acetone cyanohydrin route (ACH process) is the most traditional and the most mainstream production process in the world, with simple process, mature technology, and low investment, but the raw material hydrogen cyanide is a highly toxic substance, and the treatment of the three wastes is complicated.

[0004] Methylallyl alcohol (also known as 2-methylallyl alcohol) is an important organic intermediate used in the synthesis of fragrances, resins, etc. Methylallyl alcohol polyoxyethylene ether (HPEG) is synthesized with methylallyl alcohol and ethylene oxide as raw materials and is used in the new generation of high-performance concrete water reducers. Methylallyl alcohol can be used to synthesize methacrylic acid and its esters, and can also be used with other organic acids to synthesize esters containing allyl groups, which has important applications in polymerization monomers, surfactants, etc.

[0005] The traditional method for preparing methyl allyl alcohol is to use 2-methyl allyl chloride as the starting material and adopt alkaline hydrolysis to produce methyl allyl alcohol, but a large amount of by-product ether will be produced, resulting in a low yield.

[0006] Therefore, it is necessary to improve the traditional technology. Summary of the invention

[0007] Based on this, the present application provides a method for co-producing methacrylate and methallyl alcohol with a higher yield.

[0008] The technical solution of this application to solve the above technical problems is as follows.

[0009] On the one hand, the present application provides a method for co-producing methacrylate and methallyl alcohol, comprising the following steps:

[0010] Mixing methacrolein, a first catalyst and a non-protonic non-polar solvent to perform a Tisenko reaction to obtain a first reaction solution; the first catalyst includes aluminum alcoholate;

[0011] The fatty alcohol, the second catalyst and the first reaction solution are mixed to carry out an ester exchange reaction to prepare methacrylate and methallyl alcohol; the second catalyst comprises at least one of titanate and organotin.

[0012] In some of the embodiments, in the method for co-producing methacrylate and methallyl alcohol, the aprotic non-polar solvent includes at least one of hydrocarbons, halogenated hydrocarbons and ethers.

[0013] In some of the embodiments, in the method for co-producing methacrylate and methallyl alcohol, the aprotic non-polar solvent includes at least one of toluene, xylene, cyclohexane, n-heptane, dichloromethane, dichloroethane, isopropyl ether and butyl ether.

[0014] In some of the embodiments, in the method for co-producing methacrylate and methallyl alcohol, the mass ratio of the aprotic non-polar solvent to the methacrolein is 0.1-0.8:1.

[0015] In some embodiments, in the method for co-producing methacrylate and methallyl alcohol, the titanate comprises at least one of tetrabutyl titanate, tetramethyl titanate, tetraethyl titanate, tetraisopropyl titanate, tetraisobutyl titanate and tetraisooctyl titanate; and / or

[0016] The organic tin comprises at least one of dibutyltin dilaurate, dibutyltin diacetate, dibutyltin oxide and di(dodecylsulfide)dibutyltin.

[0017] In some of the embodiments, in the method for co-producing methacrylate and methallyl alcohol, the molar ratio of the second catalyst to the methacrolein is 0.01-0.03:1.

[0018] In some of the embodiments, in the method for co-producing methacrylate and methallyl alcohol, the aluminum alcoholate catalyst comprises at least one of aluminum isopropoxide, aluminum sec-butoxide, aluminum tert-butoxide and aluminum ethoxide; and / or

[0019] The molar ratio of the first catalyst to the methacrolein is 0.01-0.03:1.

[0020] In some embodiments, in the method for co-producing methacrylate and methallyl alcohol, the fatty alcohol comprises at least one of methanol, ethanol, propanol, isopropanol, butanol and isobutanol; and / or

[0021] The molar ratio of the fatty alcohol to the methacrolein is 1-4:1.

[0022] In some embodiments, in the method for co-producing methacrylate and methallyl alcohol, the temperature of the Tischenko reaction is 20° C. to 50° C., and the time is 20 h to 48 h; and / or

[0023] The Tischenko reaction is carried out under inert atmosphere.

[0024] In some embodiments, in the method for co-producing methacrylate and methallyl alcohol, the Tischchenko reaction is carried out in the presence of an inhibitor.

[0025] In some embodiments, in the method for co-producing methacrylate and methallyl alcohol, the mass ratio of the polymerization inhibitor to the methacrolein is 0.0001-0.001:1; and / or

[0026] The polymerization inhibitor includes at least one of p-methoxyphenol and hydroquinone.

[0027] In some of the embodiments, in the method for co-producing methacrylate and methallyl alcohol, the transesterification reaction is carried out at reflux temperature, and the reflux time is 3 h to 6 h.

[0028] Compared with the prior art, the method for co-producing methacrylate and methallyl alcohol of the present application has the following beneficial effects:

[0029] The method for co-producing methacrylate and methallyl alcohol of the present application is to carry out a Teishchenko reaction on methacrolein under the action of a cheap and readily available first catalyst and a non-protonic non-polar solvent, so that the conversion rate of methacrolein is high and the selectivity of the generated methallyl methacrylate is high; by adopting a specific type of second catalyst, there is no need to post-treat the first reaction liquid obtained by the Teishchenko reaction, and the first reaction liquid containing methallyl methacrylate is directly subjected to an ester exchange reaction with a fatty alcohol under the action of the specific type of second catalyst, so that methacrylate and methallyl alcohol can be co-produced in one pot, and the yield is high, the by-products are less, and the purity of methacrylate and methallyl alcohol is high. DETAILED DESCRIPTION

[0030] The present application will be further described in detail below in conjunction with the embodiments and examples. It should be understood that these embodiments and examples are only used to illustrate the present application and are not used to limit the scope of the present application. The purpose of providing these embodiments and examples is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0031] It should also be understood that the present application can be implemented in many different forms and is not limited to the embodiments and examples described herein. Those skilled in the art can make various changes or modifications without violating the connotation of the present application, and the equivalent forms obtained also fall within the scope of protection of the present application. For example, the features illustrated or described as part of one embodiment can be combined in another embodiment in a suitable manner to produce a new embodiment. In addition, in the description below, a large number of specific details are given in order to provide a more comprehensive understanding of the present application. It should be understood that the present application can be implemented without one or more of these details.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing implementation modes and embodiments and are not intended to limit this application.

[0033] Unless otherwise specified or incompatible herewith, the terms and phrases used herein shall have the following meanings:

[0034] In the present application, "plurality", "multiple", "multiple times", etc., unless otherwise specified, refer to a quantity greater than 2 or equal to 2. For example, "one or more" means one or greater than or equal to two.

[0035] As used herein, "combination thereof", "any combination thereof", "any combination thereof" etc. include all suitable combinations of any two or more of the listed items.

[0036] Herein, the “suitable” mentioned in “suitable combination”, “suitable method”, “any suitable method”, etc., shall be based on the ability to implement the technical solution of this application, solve the technical problems of this application, and achieve the expected technical effects of this application.

[0037] Herein, "preferred", "better", "more preferred", and "suitable" are only used to describe implementation methods or examples with better effects, and it should be understood that they do not constitute a limitation on the scope of protection of this application. If multiple "preferred" items appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "preferred" item is independent.

[0038] In the present application, "further", "further", "particularly" and the like are used for descriptive purposes to indicate differences in content, but should not be construed as limiting the scope of protection of the present application.

[0039] In this application, "optionally", "optional", and "optional" mean optional or dispensable, that is, any one of the two parallel schemes of "yes" or "no". If multiple "options" appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "optional" is independent.

[0040] In the present application, the terms "first", "second", "third", "fourth", etc. in "the first aspect", "the second aspect", "the third aspect", "the fourth aspect", etc. are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or quantity, nor can they be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first", "second", "third", "fourth", etc. only serve the purpose of non-exhaustive enumeration and description, and it should be understood that they do not constitute a closed limitation on quantity.

[0041] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0042] In the present application, when it comes to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values ​​in the numerical interval is considered to be continuous, and includes the two numerical endpoints (i.e., the minimum value and the maximum value) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to the integers in the numerical interval, it includes the two endpoint integers of the numerical range, and each integer between the two endpoints, which is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be combined. In other words, unless otherwise specified, the numerical range disclosed herein should be understood to include any and all sub-ranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows broadly including numerical interval types such as percentage intervals, ratio intervals, and ratio intervals.

[0043] The temperature parameters in this application, unless otherwise specified, are allowed to be either constant temperature treatment or to vary within a certain temperature range. It should be understood that the constant temperature treatment allows the temperature to fluctuate within the accuracy range controlled by the instrument. Fluctuations within the range of ±5°C, ±4°C, ±3°C, ±2°C, and ±1°C are allowed.

[0044] In this application, the term "room temperature" or "normal temperature" generally refers to 4°C to 35°C, for example, 20°C ± 5°C. In some embodiments of this application, "room temperature" or "normal temperature" refers to 10°C to 30°C. In some embodiments of this application, "room temperature" or "normal temperature" refers to 20°C to 30°C.

[0045] In this application, when referring to the unit of a data range, if there is a unit only after the right endpoint, it means that the units of the left and right endpoints are the same. For example, 3~5 h means that the units of the left endpoint "3" and the right endpoint "5" are both h (hours).

[0046] All documents mentioned in this application are cited as references in this application, just as each document is cited as reference separately. Unless they conflict with the invention purpose and / or technical solution of this application, the cited documents involved in this application are cited with all contents and all purposes. When the cited documents are involved in this application, the definitions of relevant technical features, terms, nouns, phrases, etc. in the cited documents are also cited. When the cited documents are involved in this application, the examples and preferred methods of the cited relevant technical features can also be incorporated into this application as references, but are limited to the implementation of this application. It should be understood that when the cited content conflicts with the description in this application, the present application shall prevail or be modified adaptively according to the description of this application.

[0047] The mass or weight of the relevant components mentioned in the specification of the embodiments of the present application may not only refer to the specific content of each component, but also indicate the proportional relationship of the mass or weight between the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the specification of the embodiments of the present application, it is within the scope disclosed in the specification of the embodiments of the present application. Specifically, the mass or weight described in the specification of the embodiments of the present application may be units known in the chemical industry such as μg, mg, g, and kg.

[0048] The Tishchenko reaction is an organic reaction in which an aldehyde without α-active hydrogen undergoes a disproportionation reaction to form an ester in the presence of an alkoxide (such as aluminum alkoxide).

[0049]

[0050] The transesterification reaction is the reaction of an ester and an alcohol to generate a new ester and a new alcohol under the catalysis of an acid or a base, that is, the alcoholysis reaction of an ester.

[0051]

[0052] An embodiment of the present application provides a method for co-producing methacrylate and methallyl alcohol, comprising the following steps:

[0053] Step S10: Mixing methacrolein, a first catalyst and a non-protonic non-polar solvent to perform a Tischenberg reaction to obtain a first reaction solution; the first catalyst includes aluminum alcoholate.

[0054] Methacrolein is subjected to a Teishchenko reaction in the presence of a cheap and readily available first catalyst and a non-protonic non-polar solvent, the conversion rate of methacrolein is high, and the selectivity of the generated methallyl methacrylate is high.

[0055] In some examples, in step S10, the aprotic non-polar solvent includes at least one of hydrocarbons, halogenated hydrocarbons, and ethers.

[0056] In some of the examples, in step S10, the hydrocarbon aprotic non-polar solvent includes but is not limited to at least one of alkanes and aromatic hydrocarbons; further, the halogenated hydrocarbons include but are not limited to halogenated alkanes.

[0057] In some examples, in step S10, the aprotic non-polar solvent includes at least one of toluene, xylene, cyclohexane, n-heptane, dichloromethane, dichloroethane, isopropyl ether and butyl ether.

[0058] In some of the examples, in step S10, the mass ratio of the aprotic non-polar solvent to methacrolein is 0.1-0.8:1.

[0059] It can be understood that the mass ratio of the aprotic non-polar solvent to methacrolein includes but is not limited to 0.1:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, and 0.8:1; in some examples, it can be within the range formed by any two of these point values ​​as end values, the same below.

[0060] Optionally, in step S10, the mass ratio of the aprotic non-polar solvent to methacrolein is 0.3-0.8:1.

[0061] In some examples, in step S10, the aluminum alkoxide catalyst includes at least one of aluminum isopropoxide, aluminum sec-butoxide, aluminum tert-butoxide, and aluminum ethoxide.

[0062] In some of the examples, in step S10, the molar ratio of the first catalyst to methacrolein is 0.01-0.03:1.

[0063] It is understood that the molar ratio of the first catalyst to methacrolein includes, but is not limited to, 0.01:1, 0.012:1, 0.015:1, 0.018:1, 0.02:1, 0.022:1, 0.025:1, 0.028:1, and 0.03:1.

[0064] Optionally, in step S10, the molar ratio of the first catalyst to methacrolein is 0.02-0.03:1.

[0065] In some of the examples, in step S10, the temperature of the Jixianke reaction is 20°C to 50°C, and the time is 20 h to 48 h.

[0066] It will be appreciated that the temperature of the Jixianke reaction includes but is not limited to 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, and 50°C, and the time includes but is not limited to 20 h, 24 h, 28 h, 30 h, 34 h, 38 h, 40 h, 44 h, 45 h, and 48 h.

[0067] Optionally, in step S10, the temperature of the Jixianke reaction is 25°C to 40°C; further, the temperature of the Jixianke reaction is 30°C to 35°C.

[0068] Optionally, in step S10, the time of the Jixianke reaction is 20 h to 45 h.

[0069] In some of the examples, in step S10, the Tishchenko reaction is performed under an inert atmosphere.

[0070] It can be understood that the inert atmosphere includes but is not limited to nitrogen and noble gases; further, the inert gas includes argon and the like.

[0071] In some of the examples, in step S10, the Tischenko reaction is performed in the presence of a polymerization inhibitor.

[0072] In some of the examples, in step S10, the mass ratio of the polymerization inhibitor to methacrolein is 0.0001-0.001:1.

[0073] It can be understood that the mass ratio of the inhibitor to methacrolein includes but is not limited to 0.0001:1, 0.0002:1, 0.0003:1, 0.0004:1, 0.0005:1, 0.0006:1, 0.0007:1, 0.0008:1, 0.0009:1, and 0.001:1.

[0074] Optionally, in step S10, the mass ratio of the polymerization inhibitor to methacrolein is 0.0003-0.008:1.

[0075] In some examples, in step S10, the polymerization inhibitor includes at least one of p-methoxyphenol and hydroquinone.

[0076] In some examples, step S10 includes the following steps:

[0077] mixing the catalyst with an aprotic nonpolar solvent to prepare a catalyst solution;

[0078] Methacrolein and an inhibitor are mixed and added dropwise to the catalyst solution to carry out a Tisenko reaction.

[0079] Step S20: mixing the fatty alcohol, the second catalyst and the first reaction solution to carry out an ester exchange reaction to prepare methacrylate and methallyl alcohol; the second catalyst comprises at least one of titanate and organotin.

[0080] The reaction routes of step S10 and step S20 are as follows:

[0081]

[0082] By adopting a specific type of second catalyst, there is no need to post-treat the first reaction liquid obtained from the kisenko reaction in step S10. The first reaction liquid containing methyl allyl methacrylate can be directly subjected to an ester exchange reaction with a fatty alcohol under the action of the specific type of second catalyst, thereby achieving one-pot co-production of methyl methacrylate and methyl allyl alcohol with a higher yield, less by-products, and higher purity of methyl methacrylate and methyl allyl alcohol.

[0083] The one-pot process produces methacrylate and methallyl alcohol, which reduces the separation and purification steps of the intermediates, thereby reducing costs and time. In addition, the one-pot process also has significant advantages in terms of environmental friendliness, reducing the steps of chemical reactions and the generation of waste, which is in line with the principles of green chemistry.

[0084] Furthermore, the step between step S10 and step S20 does not include a step of post-treating the first reaction liquid obtained by the Jixianke reaction in step S10.

[0085] The study found that when the first reaction solution containing methallyl methacrylate and fatty alcohol were directly subjected to an ester exchange reaction under the action of phosphoric acid, the conversion rate of methallyl methacrylate was low, resulting in a low yield of methacrylate and methallyl alcohol. Analysis showed that the alkaline catalyst was used in the Jisenko reaction in step S10, and an acidic catalyst was used in step S20 in the one-pot method. Phosphoric acid was consumed by the Jisenko reaction catalyst aluminum alcohol to generate aluminum phosphate, which lost its catalytic effect, resulting in a low degree of reaction.

[0086] In some examples, in step S20, the titanate includes at least one of tetrabutyl titanate, tetramethyl titanate, tetraethyl titanate, tetraisopropyl titanate, tetraisobutyl titanate, and tetraisooctyl titanate.

[0087] In some examples, in step S20, the organic tin includes at least one of dibutyltin dilaurate, dibutyltin diacetate, dibutyltin oxide, and dibutyltin didodecylsulfide.

[0088] Optionally, the second catalyst includes at least one of tetrabutyl titanate and dibutyltin dilaurate.

[0089] In some of the examples, in step S20, the molar ratio of the second catalyst to methacrolein is 0.01-0.03:1.

[0090] It is understood that the molar ratio of the second catalyst to methacrolein includes, but is not limited to, 0.01:1, 0.012:1, 0.015:1, 0.018:1, 0.02:1, 0.022:1, 0.025:1, 0.028:1, and 0.03:1.

[0091] Optionally, the molar ratio of the second catalyst to methacrolein is 0.01-0.02:1.

[0092] In some examples, in step S20, the fatty alcohol includes at least one of methanol, ethanol, propanol, isopropanol, butanol, and isobutanol.

[0093] In some examples, in step S20, the molar ratio of fatty alcohol to methacrolein is 1-4:1.

[0094] It is understood that the molar ratio of fatty alcohol to methacrolein includes, but is not limited to, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, and 4:1.

[0095] Optionally, the molar ratio of fatty alcohol to methacrolein is 2-4:1.

[0096] In some of the examples, in step S20, the transesterification reaction is carried out at reflux temperature, and the reflux time is 3 h to 6 h.

[0097] It is understood that the reflux temperature refers to the process of maintaining a constant temperature of the reaction system by continuously flowing certain reactants or products back into the reactor during a chemical reaction. Further, the reflux time includes but is not limited to 3 h, 4 h, 5 h, and 6 h.

[0098] In some examples, in step S20, the transesterification reaction is performed under an inert atmosphere.

[0099] It can be understood that the inert atmosphere includes but is not limited to nitrogen and noble gases; further, the inert gas includes argon and the like.

[0100] In some of the examples, in step S20, after the transesterification reaction, the reaction solution is distilled to obtain methacrylate and methallyl alcohol.

[0101] The method for co-producing methacrylate and methallyl alcohol in the present application does not require the use of precious metal palladium or gold catalysts, and does not require the use of highly toxic raw material hydrocyanic acid. It has high atom economy, low cost, mild reaction conditions, and a clean and green process.

[0102] The present application is further described in detail below in conjunction with specific implementation methods, but the implementation methods of the present application are not limited thereto.

[0103] Example 1

[0104] Jixianke reaction: under nitrogen protection, add 30 mL of xylene and 4.1 g (0.02 mol) of aluminum triisopropoxide to a 250 mL three-necked flask, stir and dissolve evenly, then add 70 g of methacrolein (1 mol) and 0.036 g of p-methoxyphenol (the mass ratio of inhibitor to methacrolein is 0.0005:1) solution dropwise from a constant pressure dropping funnel, and complete the addition within 2 hours. Control the reaction temperature at 30°C~35°C, keep warm for 30 hours, and gas phase analysis shows that the mass content of methacrolein is 0.25%, and obtain methallyl methacrylate reaction solution;

[0105] Ester exchange reaction: 96 g of methanol (3 mol) and 6.32 g of dibutyltin dilaurate (the molar ratio of the second catalyst to methacrolein is 0.01:1) were added to the above methallyl methacrylate reaction solution, heated to methanol reflux, and reacted for 5 hours. According to gas phase analysis, the mass content of methallyl methacrylate was 0.35%; by distillation, 42.9 g of methyl methacrylate was obtained with a purity of 99.50% and a molar yield of 42.9%; 34.2 g of methallyl alcohol was obtained with a purity of 99.6% and a molar yield of 47.5%.

[0106] Molar yield = (mass of product ÷ molar mass of product) / molar amount of raw material × 100%; for example, the molar yield of methyl methacrylate in Example 1 = (42.9 g ÷ 100.12 g / mol) / 1 mol × 100% = 42.9%.

[0107] Theoretically, 2 mol of methacrolein produces 1 mol of methyl methacrylate and 1 mol of methyl allyl alcohol, so the theoretical yield of methyl methacrylate and methyl allyl alcohol is 50%.

[0108] Example 2

[0109] Jixianke reaction: under nitrogen protection, add 30 mL of xylene and 4.1 g (0.02 mol) of aluminum triisopropoxide to a 250 mL three-necked flask, stir and dissolve evenly, then add 70 g of methacrolein (1 mol) and 0.036 g of p-methoxyphenol solution from a constant pressure dropping funnel, and complete the addition in 2 hours. Control the reaction temperature at 30-35°C and keep warm for 30 hours. According to gas phase analysis, the mass content of methacrolein is 0.25%, and methallyl methacrylate reaction solution is obtained;

[0110] Ester exchange reaction: 180 g of n-propanol (3 mol) and 6.32 g of dibutyltin dilaurate were added to the above methallyl methacrylate reaction solution, heated to methanol reflux, and reacted for 8 hours. According to gas phase analysis, the mass content of methallyl methacrylate was 0.35%. By distillation, 53.2 g of propyl methacrylate was obtained with a purity of 99.60% and a molar yield of 41.5%. 34.0 g of methylallyl alcohol was obtained with a purity of 99.6% and a molar yield of 47.2%.

[0111] Example 3

[0112] Jixianke reaction: under nitrogen protection, add 30 mL of xylene and 6.2 g (0.03 mol) of aluminum triisopropoxide to a 250 mL three-necked flask, stir and dissolve evenly, then add 70 g of methacrolein (1 mol) and 0.036 g of p-methoxyphenol solution from a constant pressure dropping funnel, and complete the addition in 2 hours. Control the reaction temperature at 30-35 °C and keep warm for 20 hours. According to gas phase analysis, the mass content of methacrolein is 0.20%, and methallyl methacrylate reaction solution is obtained;

[0113] Ester exchange reaction: 96 g of methanol (3 mol) and 6.32 g of dibutyltin dilaurate were added to the above methallyl methacrylate reaction solution, heated to methanol reflux, and reacted for 5 hours. According to gas phase analysis, the mass content of methallyl methacrylate was 0.35%. By distillation, 40.5 g of methyl methacrylate was obtained with a purity of 99.50% and a molar yield of 40.5%. 35.9 g of methallyl alcohol was obtained with a purity of 99.6% and a molar yield of 49.8%.

[0114] Example 4

[0115] Jixianke reaction: under nitrogen protection, add 40 mL of ethylene dichloride and 6.2 g (0.02 mol) of aluminum triisopropoxide to a 250 mL three-necked flask, stir and dissolve evenly, then add 70 g of methacrolein (1 mol) and 0.036 g of p-methoxyphenol solution from a constant pressure dropping funnel, and complete the addition in 2 hours. Control the reaction temperature at 30-35 °C and keep warm for 45 hours. According to gas phase analysis, the mass content of methacrolein is 0.50%, and methallyl methacrylate reaction solution is obtained;

[0116] Ester exchange reaction: 96 g of methanol (3 mol) and 6.32 g of dibutyltin dilaurate were added to the above methallyl methacrylate reaction solution, heated to methanol reflux, and reacted for 6 hours. According to gas phase analysis, the mass content of methallyl methacrylate was 0.45%. By distillation, 41.5 g of methyl methacrylate was obtained with a purity of 99.50% and a molar yield of 41.5%. 35.0 g of methallyl alcohol was obtained with a purity of 99.6% and a molar yield of 48.6%.

[0117] Example 5

[0118] Jixianke reaction: under nitrogen protection, add 30 mL of xylene and 4.1 g (0.02 mol) of aluminum triisopropoxide into a 250 mL three-necked flask, stir and dissolve evenly, then add 70 g of methacrolein (1 mol) and 0.03 g of hydroquinone solution from a constant pressure dropping funnel, and complete the addition in 2 hours. Control the reaction temperature at 30-35°C and keep warm for 30 hours. According to gas phase analysis, the mass content of methacrolein is 0.45%, and methallyl methacrylate reaction solution is obtained;

[0119] Ester exchange reaction: 96 g of methanol (3 mol) and 6.32 g of dibutyltin dilaurate were added to the above methallyl methacrylate reaction solution, heated to methanol reflux, and reacted for 5.5 hours. According to gas phase analysis, the mass content of methallyl methacrylate was 0.45%. By distillation, 42.2 g of methyl methacrylate was obtained with a purity of 99.50% and a molar yield of 42.2%. 33.0 g of methylallyl alcohol was obtained with a purity of 99.6% and a molar yield of 45.8%.

[0120] Example 6

[0121] Jixianke reaction: under nitrogen protection, add 30 mL of xylene and 4.1 g (0.02 mol) of aluminum triisopropoxide into a 250 mL three-necked flask, stir and dissolve evenly, then add 70 g of methacrolein (1 mol) and 0.036 g of p-methoxyphenol solution from a constant pressure dropping funnel, and complete the addition in 2 hours. Control the reaction temperature at 40-45°C and keep warm for 25 hours. According to gas phase analysis, the mass content of methacrolein is 0.25%, and methallyl methacrylate reaction solution is obtained;

[0122] Ester exchange reaction: 96 g of methanol (3 mol) and 3.40 g of tetrabutyl titanate were added to the above methallyl methacrylate reaction solution, heated to methanol reflux, and reacted for 8 hours. According to gas phase analysis, the mass content of methallyl methacrylate was 0.55%. By distillation, 40.9 g of methyl methacrylate was obtained with a purity of 99.50% and a molar yield of 40.9%. 34.8 g of methallyl alcohol was obtained with a purity of 99.6% and a molar yield of 48.3%.

[0123] Comparative Example 1

[0124] The method is basically the same as Example 1, except that the xylene in the Tischenko reaction is replaced with an equal volume of polar solvent ethyl acetate; after the Tischenko reaction was kept warm for 30 h, the reaction system became turbid, and gas phase analysis showed that methacrolein was substantially not converted.

[0125] Comparative Example 2

[0126] The method is basically the same as Example 1, except that the dibutyltin dilaurate in the transesterification reaction is replaced with an equal mass of phosphoric acid. In the transesterification reaction, the reaction is heated to methanol reflux for 8 hours, and the reaction system is turbid. After gas phase detection and analysis, only a small amount of methyl methacrylate and methyl allyl alcohol are present in the reaction solution, and most of the methyl allyl methacrylate is not converted.

[0127] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0128] The above-described embodiments only express several implementation methods of the present application, which is convenient for understanding the technical solution of the present application in detail, but it cannot be understood as limiting the scope of protection of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the scope of protection of the present application. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided in the present application are all within the scope of protection of the claims attached to the present application. Therefore, the scope of protection of the patent of this application shall be based on the content of the attached claims, and the description can be used to interpret the content of the claims.

Claims

1. A method for co-producing methacrylate and methallyl alcohol, characterized in that: The following steps are involved: Mixing methacrolein, a first catalyst and a non-protonic non-polar solvent to perform a Tisenko reaction to obtain a first reaction solution; the first catalyst includes an alcohol aluminum catalyst; The fatty alcohol, the second catalyst and the first reaction solution are mixed to carry out an ester exchange reaction to prepare methacrylate and methallyl alcohol; the second catalyst comprises at least one of titanate and organotin.

2. The method for co-producing methacrylate and methallyl alcohol according to claim 1, characterized in that: The aprotic non-polar solvent includes at least one of hydrocarbons, halogenated hydrocarbons and ethers.

3. The method for co-producing methacrylate and methallyl alcohol as claimed in claim 2, characterized in that: The aprotic non-polar solvent includes at least one of toluene, xylene, cyclohexane, n-heptane, dichloromethane, dichloroethane, isopropyl ether and butyl ether.

4. The method for co-producing methacrylate and methallyl alcohol according to claim 1, characterized in that: The mass ratio of the aprotic non-polar solvent to the methacrolein is 0.1-0.8:

1.

5. The method for co-producing methacrylate and methallyl alcohol according to claim 1, characterized in that: The titanate comprises at least one of tetrabutyl titanate, tetramethyl titanate, tetraethyl titanate, tetraisopropyl titanate, tetraisobutyl titanate and tetraisooctyl titanate; and / or The organic tin comprises at least one of dibutyltin dilaurate, dibutyltin diacetate, dibutyltin oxide and di(dodecylsulfide)dibutyltin.

6. The method for co-producing methacrylate and methallyl alcohol according to claim 1, characterized in that: The molar ratio of the second catalyst to the methacrolein is 0.01-0.03:

1.

7. The method for co-producing methacrylate and methallyl alcohol according to any one of claims 1 to 6, characterized in that: The aluminum alcoholate catalyst comprises at least one of aluminum isopropoxide, aluminum sec-butoxide, aluminum tert-butoxide and aluminum ethoxide; and / or The molar ratio of the first catalyst to the methacrolein is 0.01-0.03:1; and / or The fatty alcohol comprises at least one of methanol, ethanol, propanol, isopropanol, butanol and isobutanol; and / or The molar ratio of the fatty alcohol to the methacrolein is 1-4:

1.

8. The method for co-producing methacrylate and methallyl alcohol according to any one of claims 1 to 6, characterized in that: The temperature of the Tischenko reaction is 20°C to 50°C and the time is 20 h to 48 h; and / or The Tischenko reaction is carried out under inert atmosphere; and / or The Tischenberg reaction is carried out in the presence of a polymerization inhibitor.

9. The method for co-producing methacrylate and methallyl alcohol according to claim 8, characterized in that: The mass ratio of the polymerization inhibitor to the methacrolein is 0.0001-0.001:1; and / or The polymerization inhibitor includes at least one of p-methoxyphenol and hydroquinone.

10. The method for co-producing methacrylate and methallyl alcohol according to any one of claims 1 to 6 and 9, characterized in that: The transesterification reaction is carried out at reflux temperature, and the reflux time is 3 h to 6 h.

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