In-situ method for preparing (METH)acrylic acid aryl ester

Abstract

The present invention relates to a method for producing high-purity (meth)acrylic acid aryl esters in-situ.

Description

Technology Field

[0001] The present invention relates to a method for producing high-purity aryl (meth)acrylic acid esters in-situ. More specifically, the invention relates to a method for producing high-purity aryl (meth)acrylic acid esters by reacting (meth)acrylic anhydride converted from (meth)acrylic acid with a monovalent aryl alcohol. Background Technology

[0003] (Met)acrylic acid aryl esters can maintain the high refractive index, low hygroscopicity, and heat resistance of aryl esters, and are used in a wide range of applications such as plastics, paints, adhesives, paper processing agents, textile lubricants, lubricant additives, construction sealants, and inks, and their fields of application are expanding.

[0004] Generally, esters are produced by reacting carboxylic acids with alcohols, but the esterification reaction between (meth)acrylic acid and aryl alcohol is known to be difficult to carry out. Consequently, it is common practice to proceed with the esterification reaction using acid catalysts such as hydrochloric acid; however, this results in low yields due to the generation of large amounts of byproducts relative to the low conversion rate, and problems such as the deterioration of the final product are likely to occur when strong acids are used.

[0005] In addition, research has been conducted on the respective processes of reacting (meth)acrylic acid with (meth)acrylic anhydride and (meth)acrylic anhydride with aryl alcohol, but since (meth)acrylic acid is converted into (meth)acrylic anhydride and (meth)acrylic anhydride is obtained through a separate purification process and then reacted with aryl alcohol, additional costs are incurred due to the additional process.

[0006] Furthermore, distillation is generally performed to increase the purity of the (meth)acrylic acid aryl ester converted from (meth)acrylic anhydride, but this results in additional costs. The problem to be solved

[0008] The present specification aims to provide a method for converting (meth)acrylic acid into (meth)acrylic anhydride and (meth)acrylic acid aryl ester in an in-situ process and obtaining high-purity (meth)acrylic acid aryl ester without a separate distillation process. means of solving the problem

[0010] The present invention aims to provide a method for producing an aryl ester of (meth)acrylic acid, comprising the step of converting (meth)acrylic acid into (meth)acrylic anhydride in the presence of a sulfonyl halide, a base, and a solvent; and subsequently, the step of producing an aryl ester of (meth)acrylic acid from the (meth)acrylic anhydride and a monovalent aryl alcohol in the presence of a base and a solvent.

[0012] The terms used in this specification are used merely to describe exemplary embodiments and are not intended to limit the invention.

[0013] A singular expression includes a plural expression unless the context clearly indicates otherwise.

[0014] In this specification, terms such as “comprising,” “comprising,” or “having” are used to describe features, numbers, steps, components, or combinations thereof that are implemented, and do not exclude one or more other features, numbers, steps, components, combinations thereof, or the possibility of addition.

[0015] The present invention is capable of various modifications and may take various forms, and specific embodiments are illustrated and described in detail below. However, this is not intended to limit the invention to the specific disclosed forms, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0017] In this specification, “(meth)acrylic acid” is a general term for acrylic acid and methacrylic acid as is commonly understood. And, “monovalent aryl alcohol” means a compound in which one of the hydrogens of an aryl compound is substituted with -OH. Also, “(meth)acrylic acid aryl ester” is a general term for ester compounds synthesized through the esterification reaction of (meth)acrylic acid, a type of carboxylic acid compound, and an aryl alcohol.

[0019] The present invention will be described in detail below.

[0020] The present specification provides a method for producing an aryl ester of (meth)acrylic acid, comprising the step of converting (meth)acrylic acid into (meth)acrylic anhydride in the presence of a sulfonyl halide, a base, and a solvent; and subsequently, the step of producing an aryl ester of (meth)acrylic acid from the (meth)acrylic anhydride and a monovalent aryl alcohol in the presence of a base and a solvent.

[0022] The method for producing an aryl (meth)acrylic acid ester from (meth)acrylic acid according to the present invention proceeds in a two-step reaction.

[0023] First, the step involves converting (meth)acrylic acid into (meth)acrylic anhydride in the presence of a sulfonyl halide, a base, and a solvent. Specifically, in the presence of a base, the terminal hydrogen of (meth)acrylic acid is released from the halogen of the sulfonyl halide, causing the two compounds to combine. The combined compound then reacts with (meth)acrylic acid, releasing the sulfonic acid and converting it into (meth)acrylic anhydride. As described above, the mechanism of the conversion process from (meth)acrylic acid to (meth)acrylic anhydride is summarized as follows.

[0024]

[0025] Since (meth)acrylic acid has higher reactivity with sulfonyl halides than with alcohols, converting (meth)acrylic acid to (meth)acrylic anhydride using sulfonyl halides as described above can increase the conversion rate of (meth)acrylic acid compared to directly esterifying (meth)acrylic acid with alcohols. In addition, compared to the case of directly esterifying (meth)acrylic acid, going through the anhydride conversion step allows the reaction to proceed under milder conditions, thereby suppressing the formation of by-products in the esterification reaction with alcohols described later.

[0026] When (meth)acrylic acid is partially converted to (meth)acrylic anhydride, a monovalent aryl alcohol is added to the mixture of (meth)acrylic acid and (meth)acrylic anhydride. At this time, the method for producing an aryl ester of (meth)acrylic acid according to the present invention is an in-situ manufacturing method in which a monovalent aryl alcohol is added to proceed with the reaction without separately purifying the mixture of (meth)acrylic acid and (meth)acrylic anhydride. As such, there is an advantage in that process costs can be lowered and the process is simple because separate purification of (meth)acrylic anhydride is not required. In addition, a base and a solvent may be added to react (meth)acrylic anhydride with the monovalent aryl alcohol, or they may be added together when the monovalent aryl alcohol is added.

[0028] As described above, when an aryl ester of (meth)acrylic acid is manufactured according to the present invention, a high-purity aryl ester of (meth)acrylic acid can be manufactured through a simple process.

[0030] Meanwhile, the present invention provides a method for manufacturing an aryl methacrylate ester, further comprising the step of washing a mixture containing the aryl methacrylate ester with a compound represented by the following chemical formula 1.

[0031] [Chemical Formula 1]

[0032] R7-CN

[0033] In the above chemical formula 1,

[0034] R7 is C 1-10 It is an alkyl.

[0036] In the above chemical formula 1, C 1-10 The alkyl group may be a straight-chain, branched-chain, or cyclic alkyl group. Specifically, the above C 1-10 Alkyl is C 1-10 Straight-chain alkyl; C 1-7 Straight-chain alkyl; C 1-5 Straight-chain alkyl; C 3-10 Branched or cyclic alkyl; C 3-7 Branched or cyclic alkyl; or C 3-5 It may be a branched-chain or cyclic alkyl. More specifically, C 1-10 The alkyl group may be methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, n-pentyl, iso-pentyl, or cyclohexyl, etc.

[0038] Generally, when aryl esters (meth)acrylate are produced, they contain some solvent and impurities, so a separate purification process is required to produce high-purity aryl esters (meth)acrylate. Accordingly, a purification method in which aryl esters are obtained by distilling aryl esters from a liquid mixture containing aryl esters (meth)acrylate is known as a general technique, and there is also a method of filtration after treatment with magnesium sulfate, etc.

[0039] However, in order to obtain a high-purity product through the above distillation process, it is carried out under reduced pressure, but in this case, polymers may be produced and separate equipment for reduced pressure distillation is required, which has the problem of increasing process costs.

[0041] Accordingly, as a result of continuous research, the inventors confirmed that high-purity aryl (meth)acrylate esters can be obtained through simpler processes, such as decantation using a specific solvent and a washing step, without recovering aryl (meth)acrylate esters through vacuum distillation as described above.

[0042] A process for obtaining high-purity aryl esters of (meth)acrylic acid without distilling (meth)acrylic acid may be as follows, but is not limited thereto. When (meth)acrylic acid is reacted with an aryl alcohol to produce aryl esters of (meth)acrylic acid, the target product, aryl esters of (meth)acrylic acid, exists in a mixture containing unreacted materials, residual solvent, triethylamine salts, and other by-products. In the mixture after the reaction is completed, the triethylamine salts are first removed by filtration, and the solvent in the filtrate is removed by distillation. Subsequently, the remaining mixture containing aryl esters of (meth)acrylic acid is dissolved in an organic solvent such as hexane, cyclohexane, heptane, isooctane, and / or pentane, decanted, and washed with an aqueous sodium hydroxide solution. Next, the organic solvent layer is washed with a compound represented by Chemical Formula 1 above to remove impurities. Subsequently, the organic solvent is removed through methods such as distillation to obtain the final high-purity (meth)acrylate aryl ester.

[0043] The compound represented by Chemical Formula 1 above is specifically a nitrile-based compound containing -CN. The nitrile-based compound does not mix with organic solvents containing hexane, etc., containing (meth)acrylate ester, and is effective in removing impurities other than (meth)acrylate ester present in the organic solvent layer even in small amounts. In addition, the organic solvent has a lower boiling point and higher volatility compared to (meth)acrylate ester, so it can be removed by distillation at a relatively low temperature. Therefore, high-purity (meth)acrylate ester can be obtained while solving problems such as polymer formation and increased process costs that may occur when (meth)acrylate ester is subjected to vacuum distillation.

[0044] According to one embodiment of the present invention, the compound represented by Formula 1 may be a mixture comprising one or more selected from the group consisting of acetonitrile, propionitrile, and butyronitrile.

[0046] Meanwhile, in the present invention, the sulfonyl halide may be a compound represented by the following chemical formula 2.

[0047] [Chemical Formula 2]

[0048]

[0049] In the above chemical formula 2,

[0050] R8 is substituted or unsubstituted C 1-10 Alkyl, or substituted or unsubstituted C 6-20 Arilgo,

[0051] X is a halogen.

[0052] Preferably, R8 may be methyl, ethyl, n-propyl, iso-propyl, cyclopropyl, cyclobutyl, phenyl, tolyl, or naphthyl.

[0053] Preferably, X can be chloro.

[0054] Specifically, the sulfonyl halide may include one or more selected from the group consisting of methanesulfonyl chloride, ethanesulfonyl chloride, n-propanesulfonyl chloride, iso-propanesulfonyl chloride, cyclopropanesulfonyl chloride, cyclobutanesulfonyl chloride, benzenesulfonyl chloride, toluenesulfonyl chloride, and naphthalenesulfonyl chloride. Preferably, the sulfonyl halide may be methanesulfonyl chloride, ethanesulfonyl chloride, or toluenesulfonyl chloride.

[0056] In addition, according to one embodiment of the present invention, the base may include one or more of triethylamine and tetramethylethylenediamine. Preferably, the base may be triethylamine.

[0058] The above base can be used as a reaction catalyst for (meth)acrylic acid and sulfonyl halide or as a reaction catalyst for the esterification reaction of (meth)acrylic anhydride. As previously mentioned, when an acid catalyst is used for the esterification reaction of a carboxylic acid such as (meth)acrylic acid, there are problems such as the generation of by-products. However, the manufacturing method using the base catalyst of the present invention can improve the conversion rate of (meth)acrylic acid and suppress the generation of by-products by undergoing a process of converting (meth)acrylic acid into (meth)acrylic anhydride under milder conditions compared to an acid catalyst, thereby ultimately improving the yield of (meth)acrylic acid aryl ester.

[0059] In addition, according to one embodiment of the present invention, the base may be used in an amount of 2.3 to 3.5 equivalents, preferably 2.5 to 3.1 equivalents, relative to the equivalent of the sulfonyl halide. If the amount of the base is less than 2.3 equivalents, there may be a problem with the reaction rate slowing down, and if it exceeds 3.5 equivalents, by-products may be generated.

[0061] According to one embodiment of the present invention, the reaction solvent may include one or more selected from the group consisting of ethyl acetate, toluene, methyl-tert-butyl-ether, tetrahydrofuran, and xylene.

[0062] Preferably, the reaction solvent may be methyl-tert-butyl-ether.

[0063] The above reaction solvent serves as a reaction medium in the (meth)acrylic anhydride conversion reaction and the (meth)acrylic acid aryl ester conversion reaction.

[0064] In addition, the solvent may be used in an amount of 100 ml to 200 ml per mole of (meth)acrylic acid. If the amount of the solvent is less than 100 ml per mole of (meth)acrylic acid, there may be a problem with mixing the reactants, and if it exceeds 200 ml per mole of (meth)acrylic acid, there may be a problem with slowing down the reaction rate due to the low concentration of the reactants.

[0066] Meanwhile, according to one embodiment of the present invention, the monovalent aryl alcohol may be, more specifically, a compound represented by the following chemical formula 3.

[0067] [Chemical Formula 3]

[0068]

[0069] In the above chemical formula 3,

[0070] R1 to R4 are identical or different, and each independently hydrogen, -OH, or C 1-10 It is an alkoxy, provided that if any one of R1 to R4 is -0H, the remainder is hydrogen or C 1-10 It is an alkoxy,

[0071] R5 and R6 are hydrogen, or combine to form a benzene ring.

[0072] In the above chemical formula 3, C 1-10 The alkoxy can be a straight-chain, branched-chain, or cyclic alkoxy. Specifically, C 1-10 Alkoxy is C 1-10 Linear alkoxy; C 1-7 Linear alkoxy; C 1-5 Linear alkoxy; C 3-10 Branched or cyclic alkoxy; C 3-7 Branched chain or cyclic alkoxy; or C 3-5 It may be a branched chain or a cyclic alkoxy. More specifically, C 1-20 The alkoxy may be methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, iso-butoxy, tert-butoxy, or cyclohexoxy, etc.

[0073] Specific examples of the above monovalent aryl alcohol may be phenol, 4-methoxyphenol, 2-naphthol, or a mixture thereof.

[0075] In the method for producing an aryl meth)acrylic acid ester according to the present invention described above, the conversion step of the (meth)acrylic anhydride may be carried out at 0°C to 40°C, and the production step of the aryl meth)acrylic acid ester may be carried out at 40°C to 60°C. More preferably, the conversion step of the (meth)acrylic anhydride may be carried out at 0°C to 35°C, and the production step of the aryl meth)acrylic acid ester may be carried out at 45°C to 55°C. By controlling the temperature of each reaction step as described above, the present invention enables the reaction to proceed at a lower temperature compared to the direct esterification reaction of (meth)acrylic acid, thereby suppressing the generation of byproducts or the polymerization of acrylic compounds. Furthermore, within the above temperature range, the conversion of (meth)acrylic acid to the anhydride of (meth)acrylic acid, and the esterification reaction of the converted (meth)acrylic anhydride with a monovalent aryl alcohol, can be carried out effectively.

[0077] In addition, the method for producing an aryl (meth)acrylic acid ester of the present invention may further include a polymerization inhibitor. The polymerization inhibitor may be freely added within a range that does not impair the purpose of the invention, such as the step of converting (meth)acrylic acid into (meth)acrylic anhydride and the step of converting (meth)acrylic anhydride into an aryl (meth)acrylic acid ester. Effects of the invention

[0079] According to the method for producing (meth)acrylic acid aryl ester of the present invention, high-purity (meth)acrylic acid aryl ester can be produced without a separate purification process for the intermediate product, (meth)acrylic acid anhydride. Specific details for implementing the invention

[0081] The operation and effects of the invention will be described in more detail below through specific embodiments. However, these embodiments are merely examples of the invention and do not define the scope of the invention.

[0083] <Example>

[0084] Methanesulfonyl chloride (114.6 g, 1.0 mol), methacrylic acid (172.3 g, 2.0 mol), and ethyl acetate (EA, 200 ml) were added to a 2 L reactor. Subsequently, triethylamine (204.5 g, 2.02 mol) was added while stirring at 0°C. After stirring at room temperature for 3 hours, the synthesis of methacrylic anhydride was confirmed by monitoring with NMR or GC. Once the synthesis of methacrylic anhydride was complete, phenol (103.6 g, 1.1 mol) was dissolved in ethyl acetate (110 ml) and added to the mixture. Then, triethylamine (103.3 g, 1.02 mol) was added, and the mixture was stirred for 10 hours at 50°C. After confirming the completion of the reaction with NMR or GC, the mixture was filtered using ethyl acetate (450 ml), and the ethyl acetate was distilled. The mixture was decanted three times with hexane (300 ml), and then the hexane was washed with a 5 wt% NaOH aqueous solution (500 ml). The hexane layer was further washed with acetonitrile (60 ml), and the hexane was removed by distillation to prepare purified phenyl methacrylate ester.

[0085] 1 H NMR (500 MHz, CDCl3): δ 7.38 (t, 2H), 7.22 (t, 1H), 7.11 (d, 2H), 6.34 (s, 1H), 5.73 (s, 1H), 2.05 (s, 3H).

[0087] Example 2

[0088] Phenyl methacrylate ester was prepared in the same manner as in Example 1, except that toluene was used in the same volume instead of ethyl acetate.

[0090] Example 3

[0091] Phenylic acid ester was prepared in the same manner as in Example 1, except that methyl-tert-butyl-ether (MTBE) was used in the same volume instead of ethyl acetate.

[0093] Example 4

[0094] 2-naphthyl ester of methacrylic acid was prepared in the same manner as in Example 3, except that 2-naphthol was used in equal molar amounts instead of phenol.

[0096] Example 5

[0097] 4-methoxyphenyl esters of methacrylic acid were prepared in the same manner as in Example 3, except that 4-methoxyphenol was used in equal molar amounts instead of phenol.

[0099] Example 6

[0100] Phenyl methacrylate ester was prepared in the same manner as in Example 1, except that tetramethylethylenediamine (TMEDA) was added instead of triethylamine.

[0102] Comparative Example 1

[0103] Methacryl acid (1.72 g, 0.02 mol), phenol (1.88 g, 0.02 mol), and toluene (10 ml) were added to a reaction flask. While stirring the mixture at room temperature, p-toluenesulfonic acid (p-TsOH, 0.002 mol) dissolved in toluene was slowly added. Once the addition of p-toluenesulfonic acid was complete, the temperature of the reactor was raised to 80°C and the reaction was carried out. After reacting for 24 hours, the mixture was thoroughly washed with a 5 wt% NaOH aqueous solution and water, and the reaction solvent was distilled to prepare phenyl ester of methacrylate.

[0105] Comparative Example 2

[0106] Phenyl methacrylate ester was prepared in the same manner as Comparative Example 1, except that the temperature of the reactor was raised to 125℃ and the reaction was carried out.

[0108] Comparative Example 3

[0109] Phenylic acid ester was prepared in the same manner as Comparative Example 1, except that a mixture of sulfuric acid (H2SO4, 0.0005 mol) and boric acid (B(OH)3, 0.001 mol) was used instead of p-toluenesulfonic acid, and the reaction was carried out by raising the temperature of the reactor to 150°C.

[0111] Comparative Example 4

[0112] Phenyl methacrylate ester was prepared in the same manner as in Example 1, except that triethylamine was not added.

[0114] Comparative Example 5

[0115] Phenyl methacrylate ester was prepared in the same manner as in Example 1, except that ethyl acetate was not added.

[0117] <Experimental Example>

[0118] (1) Yield and purity of aryl methacrylate ester

[0119] Purity (%): The product was analyzed using GC / FID (Agilent 7890) and a ZB-5MS capillary column (Zebron). Helium was used as the carrier gas, and the detector temperature was set to 300 ℃. The column was heated from 50 ℃ to 320 ℃ at a rate of 10 ℃ / min to identify the product and measure its purity.

[0120] Yield (%) = [(Moles of aryl methacrylate ester produced after purification) / (Moles of limiting reactant)] * 100

[0122] phenolic compounds menstruum catalyst water(%) transference number(%) Example 1 phenol EA TEA 99.3 81 Example 2 phenol Toluene TEA 99.2 81 Example 3 phenol MTBE TEA 99.5 86 Example 4 2-Naphthol MTBE TEA 99.4 85 Example 5 4-Methoxyphenol MTBE TEA 99.0 82 Example 6 phenol EA TMEDA 98.6 76 Comparative Example 1 phenol Toluene p-TsOH 98.3 25 Comparative Example 2 phenol Toluene p-TsOH 98.1 42 Comparative Example 3 phenol Xylene H2SO4, B(OH)3 97.1 21 Comparative Example 4 phenol EA - - - Comparative Example 5 phenol - TEA - polymer

[0123] As can be seen from Table 1 above, when using the method for producing (meth)acrylic acid aryl esters of the present invention, (meth)acrylic acid aryl esters can be produced from the intermediate product, methacrylic anhydride, without undergoing a separate purification or separation process, and high-purity (meth)acrylic acid aryl esters can be produced without performing a vacuum distillation process. In addition, it can be confirmed that purity and yield are improved even under mild reaction conditions compared to the case where an acid catalyst is used.

Claims

Claim 1 A method for preparing an aryl ester of (meth)acrylic acid, comprising the step of converting (meth)acrylic acid into (meth)acrylic anhydride in the presence of a sulfonyl halide, a base, and a solvent; subsequently, the step of preparing an aryl ester of (meth)acrylic acid from the (meth)acrylic anhydride and a monovalent aryl alcohol in the presence of a base and a solvent, wherein the solvent is methyl-tert-butyl-ether. Claim 2 A method for preparing an aryl ester of (meth)acrylate according to claim 1, further comprising the step of washing a mixture containing the aryl ester of (meth)acrylate with a compound represented by the following chemical formula 1. [Chemical Formula 1] R7-CN In the above chemical formula 1, R7 is C 1-10 It is an alkyl. Claim 3 A method for preparing an aryl (meth)acrylic acid ester according to claim 2, wherein the compound represented by Chemical Formula 1 comprises one or more selected from the group consisting of acetonitrile, propionitrile, and butyronitrile. Claim 4 A method for producing an aryl (meth)acrylic acid ester according to claim 1, wherein the sulfonyl halide comprises one or more selected from the group consisting of methanesulfonyl chloride, ethanesulfonyl chloride, n-propanesulfonyl chloride, iso-propanesulfonyl chloride, cyclopropanesulfonyl chloride, cyclobutanesulfonyl chloride, benzenesulfonyl chloride, toluenesulfonyl chloride, and naphthalenesulfonyl chloride. Claim 5 A method for preparing an aryl (meth)acrylic acid ester according to claim 1, wherein the base comprises one or more of triethylamine and tetramethylethylenediamine. Claim 6 A method for preparing an aryl (meth)acrylic acid ester according to claim 1, wherein the base is used in an amount of 2.3 to 3.5 equivalents relative to the equivalent of the sulfonyl halide. Claim 7 delete Claim 8 A method for preparing an aryl (meth)acrylic acid ester according to claim 1, wherein the solvent is used in an amount of 100 ml to 200 ml per mole of (meth)acrylic acid. Claim 9 A method for preparing an aryl (meth)acrylate ester according to claim 1, wherein the monovalent aryl alcohol comprises one or more of phenol, 4-methoxyphenol, and 2-naphthol. Claim 10 A method for manufacturing an aryl methacrylate ester according to claim 1, wherein the (meth)acrylate anhydride conversion step is carried out at 0°C to 40°C and the (meth)acrylate aryl ester manufacturing step is carried out at 40°C to 60°C.

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